Paduano, Angelo · Scarano, Francesco · Casalino, Damiano · et al.
200 rows × 10 cols · 39 KB · csv, jpeg
10 numeric
The interaction between acoustic waves and turbulent grazing flow over an acoustic liner is investigated using Lattice-Boltzmann Very-Large-Eddy simulations. A single-degree-of-freedom liner with 11 streamwise-aligned cavities is studied in a grazing flow impedance tube. The conditions replicate reference experiments from the Federal University of Santa Catarina. The influence of grazing flow (with a centerline Mach number of 0.32), acoustic wave amplitude, frequency, and propagation direction relative to the mean flow is analysed. Impedance is computed using both direct (i.e. the in-situ method) and model-fitting inference (i.e. the mode-matching method) methods. The former reveals strong spatial variations; however, averaged values throughout the sample show minimal differences between upstream and downstream propagating waves, in contrast to what is obtained with the latter method. Flow analyses reveal that the orifices displace the flow away from the face sheet, with this effect amplified by acoustic waves and dependent on the wave propagation direction. Consequently, the boundary layer displacement thickness ($\delta^*$) increases along the streamwise direction compared to a smooth wall and exhibits localised humps downstream of each orifice. The growth of $\delta^*$ alters the flow dynamics within the orifices by weakening the shear layer at downstream positions. This influences the acoustic-induced mass flow rate through the orifices at equal Sound Pressure Level, suggesting that acoustic energy is dissipated differently along the liner. The asymmetry of the flow field experienced by the acoustic wave, depending on its propagation direction, highlights the need to consider a spatially evolving turbulent flow when studying the acoustic-flow interaction and measuring impedance.
A study published on bioRxiv demonstrates the first hybrid quantum computing framework combining classical Hamming distance filtering with the Grover quantum search algorithm to overcome bottlenecks in massive genomic data analysis. Utilizing the IBM Qiskit 27-qubit simulator, researchers rapidly and flawlessly identified a 50-nucleotide target sequence of a Cas9-like nuclease within a Brazilian biome metagenome database, even under conditions allowing up to a 30% mismatch. The study lays a revolutionary foundation for synthetic genome design by completing simulations that precisely insert a "BioBloQu" (quantum biological block)—composed of a promoter, an RBS, an enzyme, and a terminator—into the explored scar regions of the minimal genome M. mycoides JCVI-Syn3B. [Quantum Biology Society] Modern life sciences are pouring out genomic sequencing data at an exponential rate. However, due to the immense complexity of biological data, existing classical computing methods are facing severe computational bottlenecks in analyzing and manipulating it. To break through these limitations, a disruptive study recently published on the preprint repository bioRxiv, titled "Genetic Engineering with Quantum Circuits: creating codes and studying BioBloQu genetic elements," has brought quantum computers to the forefront of genetic engineering. A joint research team led by Professor Elibio Rech from the Brazilian Agricultural Research Corporation (Embrapa) Genetic Resources and Biotechnology and the Federal University of Rio Grande do Sul (UFRGS) presented this innovative research. ■ Scanning Massive Genomic Databases with Qubits Using the core quantum mechanical principles of superposition and entanglement as the foundation for information processing, the research team developed a hybrid quantum framework that combines classical Hamming distance filtering with the Grover quantum search algorithm. Powered by IBM's Qiskit 27-qubit simulator, this algorithm was used to search for a 50-nucleotide target sequence of a Cas9-like nuclease within a Brazilian biome metagenome database. As a result, the team successfully and swiftly identified the massive genetic data through amplitude amplification, filtering out the sequence perfectly even under conditions allowing up to a 30% mismatch rate. This proves that vast amounts of genetic data, which are unmanageable for classical computers, can be analyzed in a flash through quantum parallel processing. ■ The Era of Synthetic Genome Design Opened by BioBloQu Furthermore, the researchers successfully completed a quantum circuit simulation that accurately inserts a synthetic genetic construct called "BioBloQu" (quantum biological block) into the identified target regions. In the genome of M. mycoides JCVI-Syn3B, an artificially synthesized minimal genome model, the quantum algorithm first identified two 20-nucleotide "scar" regions—which are traces of gene editing. Then, it precisely integrated a tandem genetic block (BioBloQu) composed of a promoter, a ribosome binding site (RBS), an enzyme sequence, and a terminator into that location. This innovative approach goes beyond simply cutting and pasting existing genes physicochemically; it opens up the possibility of designing and assembling novel synthetic genomes from the ground up under the control of quantum algorithms equipped with overwhelming computational power. By directly applying the computational power of quantum mechanics to biotechnology, this research is expected to serve as the starting point for a massive revolution in next-generation quantum-bio data manipulation, customized gene therapy, and synthetic biology. #QuantumComputing #GeneticRecombination #BioBloQu #QuantumAlgorithm #GroverAlgorithm #Metagenome #SyntheticBiology #GenomeDesign #QuantumBiology #KoreanQuantumBiologySociety https://www.biorxiv.org/content/10.1101/2025.05.02.651535v2
A study published on bioRxiv proposes quantum and classical graph neural networks that address the issues of parameter compression and temporal changes in protein-ligand geometry—factors previously overlooked by existing machine learning (ML) models for predicting drug dissociation kinetics (k_off). Demonstrated a significant improvement in predictive accuracy through temporal integration by introducing a 2-timestep GCN+GRU model that actively learns structural changes before and after a short molecular dynamics simulation. Proved that quantum structures act as a powerful lever for the advancement of kinetic ML models in drug design by using variational quantum circuits to compress the model head, eliminating 66% of parameters while perfectly maintaining expressive power. [Quantum Biology Society] In the field of drug design, dissociation kinetics ($k_{off}$)—the duration a drug remains bound to its target protein—is increasingly recognized as a much more critical indicator of in vivo efficacy than simple binding affinity. However, existing machine learning (ML) models have largely overlooked the dynamic, temporal changes in protein-ligand geometric structures and the fundamental computational requirement to represent complex spatial interactions with fewer parameters. A study recently published on the preprint repository bioRxiv, titled "Quantum and Classical Graph Convolutional Neural Networks for Protein Ligand Dissociation Constant Prediction," opens new horizons by extending state-of-the-art Spatial Graph Neural Networks (Spatial GNNs) in two innovative directions to break through these classical limitations. A research team at the University of Cincinnati—comprising Azamat Salamatov, Jun Bai, Gowtham Atluri, and Chaowen Guan—led this disruptive research. ■ Combining 2-Timestep Learning and Variational Quantum Circuits The first innovation introduced by the research team is the integration of temporal flow. By adopting a 2-timestep GCN+GRU model that actively learns structural changes before and after a short molecular dynamics simulation, they have elevated the accuracy of kinetic predictions to the next level. The second key innovation is groundbreaking parameter optimization utilizing quantum technology. By compressing the model head using variational quantum circuits, the researchers successfully eliminated 66% of unnecessary parameters while completely preserving the complex expressive power of the existing fully classical model. Results from the PDBbind-koff-2020 benchmark test revealed the remarkable achievement of this quantum compressed model: it perfectly matched the predictive accuracy of the heavy, fully classical model while exponentially reducing the model size. This study clearly proves that temporal kinetics and quantum neural network structures serve as a powerful, disruptive lever to break the massive computational bottlenecks that occur in future drug candidate screening processes, propelling kinetic ML models a significant leap forward. #DrugScreening #DissociationKinetics #QuantumMachineLearning #GraphNeuralNetworks #ProteinLigand #QuantumComputing #DrugDevelopment #MolecularDynamics #ArtificialIntelligence #KoreanQuantumBiologySociety https://www.biorxiv.org/content/10.1101/2025.11.20.689635v2.full
Published in the international journal PLOS Computational Biology, this study models for the first time the decrease in adult hippocampal neurogenesis in a hypomagnetic field using the 'Radical Pair Mechanism'. It establishes a theoretical mathematical model that explains the cognitive decline and reduction in reactive oxygen species (ROS) levels observed in previous mouse experiments through changes in the singlet-triplet spin dynamics of radical pairs consisting of flavin and superoxide. It demonstrates that the formation of neural networks and metabolic processes in the mammalian brain are not merely simple macroscopic biochemical reactions, but are directly governed by a microscopic quantum phenomenon: the spin dynamics of ROS electrons that depend on external magnetic fields. [Korean Society of Quantum Biology, Reporter Hak-Jin Kim] Could the radical pair mechanism—the principle by which birds sense the Earth's magnetic field to navigate—also be deeply involved in mammalian brain development and cognitive function? Recently, a theoretical study offering a clear physical answer to this remarkable quantum biological question has been published. The paper, titled "Radical pairs may explain reactive oxygen species-mediated effects of hypomagnetic field on neurogenesis," published in the international journal PLOS Computational Biology, uncovers that neurogenesis is intricately linked to a purely quantum mechanical process. The research team, led by Rishabh Rishabh and Professor Christoph Simon from the University of Calgary in Canada, spearheaded this innovative study. ■ Hypomagnetic Field Environment and the Decrease in ROS Levels According to recently published biological experimental results, mice exposed to a hypomagnetic field environment—where the geomagnetic field is largely shielded—showed significantly attenuated neurogenesis in the hippocampal region of the adult brain, resulting in a distinct decline in cognitive abilities. Surprisingly, the fundamental cause of this cognitive decline and suppressed neurogenesis was revealed to be a decrease in intracellular reactive oxygen species (ROS) levels. The University of Calgary research team mathematically analyzed the cause of this phenomenon through the lens of quantum mechanics. ■ Electron Spin Dynamics Governing Brain Development The research team constructed a radical pair model of 'flavin' and 'superoxide', which are responsible for intracellular ROS production, and simulated their spin dynamics. As a result, they found that when the external magnetic field decreases from the geomagnetic field level (approx. 50 μT) to a hypomagnetic field (approx. 0 μT), the yield of the singlet-triplet interconversion changes dramatically due to alterations in the internal hyperfine interactions of the radical pair. The mathematically calculated extent of the decrease in product yield was consistent with the reduction rate of ROS observed in actual experiments. In other words, the sophisticated formation of neural networks and metabolic processes in mammals are not simply macroscopic chemical reactions, but are directly governed by an extremely microscopic quantum phenomenon: the electron spin dynamics occurring within molecules. This research is a monumental achievement that mathematically proves the causal entanglement between the macroscopic geomagnetic environment of the Earth and the quantum spin states within living organisms. It is expected to provide a revolutionary paradigm for developing technologies that utilize magnetic fields to treat degenerative brain diseases and promote neurogenesis in the future. #QuantumBiology #RadicalPairMechanism #Magnetoreception #Neurogenesis #ReactiveOxygenSpecies #HypomagneticField #SpinDynamics #QuantumMechanics #BrainScience #KoreanSocietyOfQuantumBiology https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1010198
A study published in the international journal PCCP (Physical Chemistry Chemical Physics) models the proton transfer pathways and quantum tunneling rates during Watson-Crick tautomerism in DNA A-T and G-C base pairs, utilizing Density Functional Theory (DFT) and a machine learning-based Nudged Elastic Band (ML-NEB) algorithm. The research physically demonstrates that proton transfer in A-T base pairs is highly unstable due to an extremely low reverse-reaction barrier, making the occurrence of mutations during the replication process highly improbable. In G-C base pairs, a high quantum tunneling correction value was observed, providing the first physical proof that the mutant form (G-C) possesses a biological lifespan sufficient to be misread as an error by the human DNA replication machinery (replisome). [Korean Society of Quantum Biology, Reporter Hak-Jin Kim] The phenomenon wherein protons shift positions within the hydrogen bonds of DNA—the carrier of an organism's genetic information—can induce transient but lethal point mutations. Known as tautomerism, this process has long been identified as a potential root cause of genetic variation and oncogenesis. A recent study published in Physical Chemistry Chemical Physics (PCCP) has combined pure quantum mechanical modeling (DFT) with machine learning techniques to precisely calculate the energy barriers of double proton transfer occurring within A-T and G-C base pairs. This significant physicochemical research was conducted by L. Slocombe, J. S. Al-Khalili, and M. Sacchi of the University of Surrey, UK. ■ Instantly Collapsing A-T Tautomers vs. Surviving G-C Tautomers The research team analyzed the energy landscape as the hydrogen bond structure shifts from the standard (amino-keto) to the mutant (imino-enol) form, using Density Functional Theory (DFT) and a machine learning-based Nudged Elastic Band (ML-NEB) algorithm. The results revealed that in A-T base pairs, although a quantum tunneling effect transitioning toward the mutant A*-T* state was observed, the reverse-reaction barrier was virtually nonexistent. Consequently, the state could not be maintained and immediately collapsed back into its original standard form. The situation was different for G-C base pairs. Beyond the classical reaction where protons cross the barrier using only thermal energy at room temperature, it was confirmed that wave-like movement via quantum tunneling contributes decisively to the formation of mutant populations. The team mathematically proved that the G-C mutant (G*-C*), which showed a significantly high tunneling correction value, possesses a lifespan long enough to reach the human replisome, suggesting a high probability of solidifying into a permanent point mutation. ■ Genetic Stability Governed by Physical Laws This study is a landmark achievement, demonstrating that complex DNA mutations occurring during the most critical replication processes of life are not merely the result of random thermal fluctuations, but are substantially controlled and shaped by the microscopic physical laws of quantum tunneling dynamics. By providing objective data on how the wave-like nature of protons physically threatens the fidelity of genetic information replication, this study underscores the importance of a quantum biological approach in future research regarding DNA damage and mutation-related diseases. #DNAPointMutation #ProtonTransfer #QuantumTunneling #WatsonCrickTautomerism #BasePair #QuantumBiology #Biophysics #GeneticMutation #MolecularDynamics #KoreanSocietyOfQuantumBiology https://pubs.rsc.org/en/content/articlehtml/2021/cp/d0cp05781a
A study published on arXiv provides a structured narrative evidence map of the three complementary directions where quantum science and biology intersect: 'quantum in biology', 'quantum for biology', and 'biology for quantum'. It highlights hydrogen tunneling in enzymes and the radical-pair mechanism for magnetoreception as representative cases of quantum in biology. For quantum for biology, it analyzes how quantum sensing and imaging tools can improve biological inference. It also illuminates biology for quantum, which utilizes biomolecular self-assembly to enhance the performance of quantum devices, and presents a comprehensive benchmark to compare the current evidence and alternatives in each area. [Korean Society of Quantum Biology, Reporter Hak-Jin Kim] As we enter the 21st century, the convergence of quantum physics and the life sciences is moving beyond mere curiosity to establish itself as a substantial scientific paradigm. A recent paper published on the preprint repository arXiv, titled "Quantum in Biology, Quantum for Biology, and Biology for Quantum: Mapping the Evidence and the Road Ahead," clearly defines the three core areas where these two disciplines intersect. It provides a first-of-its-kind structured narrative evidence map that compiles the technological claims and experimental evidence of each field. A multinational collaborative research team led by Professor Travis J. A. Craddock of the University of Waterloo in Canada and Professor Francesco Petruccione of Stellenbosch University in South Africa published this extensive review. ■ Quantum in Nature and Quantum Tools Illuminating Biology The first pillar presented in this paper, 'Quantum in biology', deals with instances where quantum mechanics directly intervenes in the natural biological phenomena of living organisms. The most scientifically mature evidence highlighted includes the quantum tunneling of hydrogen in enzyme catalysis and the radical-pair spin chemistry mechanism that enables magnetoreception in birds. The second pillar, 'Quantum for biology', explores the application of cutting-edge quantum tools to the life sciences. The core question analyzed in this area is whether quantum technologies—such as quantum computing, quantum sensing, and quantum imaging—can provide significantly more precise biological inference and resolution beyond existing classical baselines, even under realistic biological constraints. ■ Living Organisms as the Foundation for Quantum Technology The final third pillar, 'Biology for quantum', is an innovative approach that utilizes biological systems in reverse to develop quantum technologies. The paper evaluates that the strongest claims in this field arise when the sophisticated structure or self-assembly capabilities unique to biomolecules are used to measurably improve the fabrication, integration, and robustness of artificial quantum devices. This monumental review paper holds great significance as it presents a macroscopic roadmap for the emerging interdisciplinary field of quantum biology. It establishes a powerful benchmark that allows for the at-a-glance comparison and verification of the current evidence levels and competitive alternative models in each specific subfield. #QuantumBiology #QuantumScience #LifeScience #InterdisciplinaryConvergence #EvidenceMap #QuantumSensing #QuantumLifeScience #QuantumTools #FutureScience #KoreanSocietyOfQuantumBiology https://arxiv.org/abs/2605.00205
Published in the journal Frontiers in Photonics, this study designs an aptamer-based platform to detect the clinically relevant dengue NS1 protein, completely reinterpreting it from the perspective of a quantum-biological interface. Moving beyond classical approaches, the research demonstrates that electrochemical capacitance systems can be treated based on the quantum characteristics of electron transport, confirming that biomolecular interactions directly modulate quantum parameters such as the density of states (DOS) of the interface. By integrating quantum-scale concepts into bioelectrochemical sensing, the analytical capability is dramatically improved, achieving high sensitivity and a broad linear range of 0.01 to 1,000 ng/mL even in complex biological matrices like commercial human serum. [Reporter Hak-Jin Kim, Korean Society of Quantum Biology] Electrochemical biosensors are promising tools for clinical diagnostics, but technical challenges have remained in maximizing stability and sensitivity for target proteins within extremely complex biological matrices like human serum. Recently, an open-access study published in the international journal Frontiers in Photonics titled "Quantum-biological interface in biosensor design: detecting proteins with electrochemical aptasensor" , presented a groundbreaking paradigm to overcome these challenges by directly introducing quantum mechanics—the physical laws of the microscopic world—into sensor design. A research team led by Leonardo Peres Chiaradia Costa and Professor Marcelo Mulato from the University of São Paulo, Brazil, spearheaded this disruptive study. ■ Beyond Classical Accumulation: Quantum Capacitance The researchers constructed a self-assembled monolayer (SAM) composed of single-stranded DNA aptamers and a spacer molecule, 6-mercapto-1-hexanol (MCH), on a gold (Au) electrode surface, and measured the binding of the dengue NS1 protein using non-Faradaic electrochemical capacitance spectroscopy (ECS). The most prominent innovation lies in the shift in how this system is interpreted. While existing models described the sensor using the classical capacitance of an electric double layer where charge accumulates geometrically, this study reinterpreted the interaction between the molecular layer and the electrode as an intrinsic electron transport characteristic known as quantum capacitance ($C_q$). This means that the interaction between the protein molecule and the aptamer goes beyond simple physicochemical docking; it directly modulates the density of electronic states (DOS) of the sensor interface and the discrete energy levels of individual molecules, thereby controlling the quantum tunneling and transfer mechanisms of electrons. ■ Overwhelming Analytical Performance Driven by Quantum Control Based on this quantum-biological interface model, the research team precisely optimized the ratio of aptamer to MCH molecules on the sensor surface to 1:50. The optimized platform successfully maintained a broad linear response ranging from 0.01 ng/mL to 1,000 ng/mL, not only in simple laboratory buffers (PBS) but also in commercial human serum entangled with complex ions and proteins. In particular, this aptasensor recorded an outstanding limit of detection (LoD) of 25.8 ng/mL in a human serum environment, clearly demonstrating how an understanding of quantum characteristics can serve as powerful leverage to break through existing biochemical limitations and design highly sensitive diagnostic devices. This study will serve as a crucial starting point for completely restructuring future protein detection and disease diagnosis technologies from the perspective of microscopic quantum dynamics rather than macroscopic chemical reactions. #QuantumBiology #Biosensor #Aptasensor #ProteinDetection #ElectrochemicalSensor #QuantumCapacitance #UltrasensitiveDiagnostics #Nanotechnology #Biophysics #KoreanSocietyOfQuantumBiology https://www.frontiersin.org/journals/photonics/articles/10.3389/fphot.2026.1714572/full
Posted on the international preprint server bioRxiv, the study provides the first direct demonstration—using multi-electrode array (MEA) electrophysiology—that the two stable lithium isotopes 6Li and 7Li exert giant and opposite effects on synaptic transmission in the rat hippocampus. 6Li rapidly strengthened synaptic transmission (amplitude +32%), whereas 7Li produced a slower but larger suppression (amplitude −58%). The difference in effect size between the two isotopes overwhelmingly exceeded the thresholds for both statistical and practical significance (Cohen's d > 300). The phenomenon is interpreted as arising from a difference in nuclear spin (7Li, spin 3/2; 6Li, spin 1) rather than mass, offering the first direct neurophysiological evidence in support of the brain's quantum cognition hypothesis. [Quantum Biology Society] Since Cade discovered lithium's dramatic neurological effects in the 1940s, the element has been studied intensively for more than seventy years, and since the mid-1970s it has served as a frontline medication for bipolar disorder. Its potential benefits are also being explored in other neurological disorders, including Alzheimer's disease. Yet despite this long clinical history and an enormous body of research, the precise mechanism by which lithium acts in the brain remains incompletely understood. It has long been known that the lithium salts prescribed in the clinic are a mixture of two stable isotopes—6Li (natural abundance 7.49%) and 7Li (92.51%)—but the question of what unique neurobiological effects each isotope produces has only recently begun to receive serious attention. A study titled "Giant and Opposite Lithium Isotope Effects on Rat Hippocampus Synaptic Activity Revealed by Multi-Electrode Array Electrophysiology" was recently posted on the international preprint server bioRxiv. Carried out by a collaborative team at the University of Waterloo in Canada spanning physics, nanotechnology, and public health—including Khadijeh Esmaeilpour, Irina Bukhteeva, Michel J.P. Gingras, Zoya Leonenko, and John G. Mielke—the work was supported by Canada's New Frontiers in Research Fund – Exploration (NFRF-E) program and the Quantum Brain Network led by Matthew Fisher (UCSB). By measuring in real time, in living brain slices, how the two lithium isotopes affect synaptic activity, the researchers demonstrated for the first time that 6Li and 7Li produce giant effects in diametrically opposite directions. ■ 6Li and 7Li: Giant and Opposite Effects on Synaptic Transmission The team prepared 350-micrometer-thick slices from the hippocampus of eight-week-old male rats, positioned the CA1 region over a 64-point multi-electrode array (MEA), and stimulated the Schaffer collateral pathway to record the evoked field excitatory postsynaptic potentials (fEPSPs). After recording a 20-minute baseline, they perfused the slices with a 20 mM lithium chloride solution for 20 minutes and then washed them out with artificial cerebrospinal fluid for a further 20 minutes. The results were dramatic. Perfusion with natural-abundance lithium (n-LiCl) reduced the fEPSP amplitude by 37%, and 7Li alone (7LiCl) produced an even stronger 58% decrease. In stark contrast, 6Li alone (6LiCl) did the opposite, driving a 32% increase in amplitude—the two isotopes pushing synaptic transmission in opposite directions. The difference between them overwhelmingly surpassed the thresholds for both statistical and practical significance (amplitude: t(8) = 481.9, p < .0001, Cohen's d = 305.7), an effect size rarely seen in neurophysiological experiments. The two isotopes also differed markedly in the speed of their response. The reaction to 6Li was very fast, reaching saturation within three minutes, whereas the responses to n-Li and 7Li were much slower, taking about ten minutes to reach their maximal change. The difference persisted even after washout: slices treated with 7Li remained 9% below baseline, while those treated with 6Li stayed 10% above it. Moreover, the chloride (LiCl) and carbonate (Li2CO3) salts yielded the same direction and a similar magnitude of effect, strongly confirming the reproducibility of the findings. ■ Why Nuclear Spin? A Quantum Biology Perspective 6Li and 7Li are chemically identical and differ only in the mass and spin of their nuclei: 7Li is a spin-3/2 nucleus and 6Li a spin-1 nucleus. The researchers argued that the very fast response to 6Li, together with the opposite effects of the two isotopes, points to a difference in nuclear spin—rather than mass-dependent factors such as slight differences in diffusion constants—as the origin of the phenomenon, since mass differences alone cannot readily account for a giant effect that reverses direction. This interpretation aligns with theoretical proposals from the expanding field of quantum biology. Matthew Fisher has advanced a quantum cognition hypothesis in which the brain could process quantum information through the nuclear spins of phosphorus atoms held within calcium phosphate clusters known as Posner molecules. Zadeh-Haghighi and Simon have separately proposed that an entangled radical-pair mechanism could explain lithium's effects on hyperactivity. Differences between the lithium isotopes have, in fact, already been observed experimentally in mitochondrial calcium cycling and in the in vitro formation of calcium phosphate clusters. The authors raised the possibility that the giant differences in synaptic activity observed here may stem from the two isotopes acting differently on the mitochondrial processes that govern synaptic activity. At the same time, they noted that a precise theoretical account of their observations is not yet available. ■ Distinct Roles Emerge in Short- and Long-Term Synaptic Plasticity The team also compared the two isotopes in synaptic plasticity, widely regarded as the basis of memory formation. In paired-pulse facilitation (PPF), a measure of short-term plasticity on the order of milliseconds, the two groups were nearly identical before lithium perfusion (127% and 130%, respectively) but diverged sharply afterward: 6Li markedly enhanced PPF to 169%, whereas 7Li suppressed it to 91%. The opposite-direction effects seen in synaptic transmission were thus reproduced in short-term plasticity as well. Long-term potentiation (LTP), which unfolds over tens of minutes, showed a somewhat different pattern. In the induction phase immediately following high-frequency stimulation (HFS), both isotopes produced potentiation, but of different magnitudes: 7Li drove a large 60% increase, while 6Li produced a much smaller 15% increase (p = .0003). In the later maintenance phase, by contrast, there was no significant difference between the two isotopes. Because both PPF and the induction phase of LTP are known to arise from rapid changes in presynaptic calcium (Ca2+) levels, the researchers focused on the possibility that the lithium isotopes act differently, primarily on presynaptic function. ■ The Significance and Outlook of the Study The central significance of this work lies in its directness. Previous studies of lithium isotope effects had remained either theoretical—such as the Posner molecule proposal—or confined to the cellular and biochemical level, as with mitochondrial calcium transport. This paper, by contrast, is the first empirical study to measure synaptic transmission in living brain slices in real time using electrophysiology, largely sidestepping the interpretive difficulties that have beset earlier behavioral experiments. The authors concluded that their findings could help clarify the presynaptic mechanisms underlying lithium's action as a mood stabilizer and, more broadly, pose new questions for quantum biology about how mass and/or nuclear spin might give rise to such effects. Above all, the study suggests that 6Li and 7Li may not be merely two forms of the same drug but pharmacologically distinct agents in their own right—a prospect that opens the door to precision therapeutic strategies that selectively harness a particular isotope. In doing so, the work lays a foundation for future research into quantum phenomena in neuronal activity. #QuantumBiology #Lithium #LithiumIsotopes #QuantumCognition #NuclearSpin #Neuroscience #Synapse #BipolarDisorder #Hippocampus #PosnerMolecule https://www.biorxiv.org/content/10.1101/2025.08.23.671929v1
Published in the American Chemical Society journal ACS Omega, the study represents hemoglobin with the FePIm (iron–porphyrin–imidazole) model and uses spin-polarized density functional theory (DFT) to track, at the atomic level, how the spin state changes over the course of oxygen binding. It shows that O2 binding proceeds as a multi-step spin crossing running from the triplet, through the quintet, to the singlet. This spin crossing dramatically lowers the binding activation barrier from 0.82 eV to 0.02 eV, accelerating the reaction. It identifies the position of the iron (Fe) atom relative to the porphyrin plane as the key indicator governing oxygen affinity, and it raises the possibility of applying the system as an oxygen-reduction catalyst in fuel cells. [Quantum Biology Society] The oxygen molecule (O2) in the air we inhale is, in its ground state, a triplet carrying two unpaired electrons. The oxygen bound to hemoglobin—oxyhemoglobin—is, by contrast, a singlet with no unpaired electrons, a fact already established in 1936 when Linus Pauling observed the diamagnetism of oxyhemoglobin. Yet a fundamental principle of quantum mechanics poses a puzzle here. In a chemical reaction, a transition in which the total spin of the reactants and products differs is forbidden by the spin selection rule (spin-forbidden) and should therefore proceed only very slowly. The direct conversion of triplet oxygen into a singlet complex is exactly such a case. How, then, does our body carry out this forbidden reaction so quickly and reversibly with every breath? A 2018 study published in the ACS journal ACS Omega, "Spin-Dependent O2 Binding to Hemoglobin," answers this question through quantum-mechanical calculations. Daiichi Kurokawa, Jessiel Siaron Gueriba, and Wilson Agerico Diño of Osaka University in Japan simplified hemoglobin's active site to the FePIm model (iron Fe, porphyrin P, imidazole Im) and used spin-polarized DFT to trace, step by step, how the system's spin state changes along the oxygen-binding pathway. They showed that O2 binding is a spin-crossing process in which the system switches successively between several spin states—and that this very process is the key that unlocks the forbidden reaction. ■ As Oxygen Approaches, the Spin Shifts Step by Step The researchers narrowed the distance (R) between the iron atom and the oxygen molecule from 7.21 angstroms (Å) in the deoxy state down to 1.84 Å in the oxy state, calculating the system's total magnetization (spin multiplicity) at each point. In the deoxyhemoglobin state, with O2 not yet bound, the entire system (FePIm plus the separated O2 molecule) was a triplet (multiplicity 3), and the iron atom protruded 0.18 Å out of the porphyrin plane. As oxygen drew closer, the spin state did not change all at once but shifted in stages. At a point about 4 Å from the iron, the electrons in oxygen's antibonding (π*) orbital flipped their spin, raising the system to a septet (multiplicity 7)—a state nearly degenerate in energy with the triplet. Then, around R = 2.4 Å, it changed to a quintet (multiplicity 5), a shift accompanied by a lengthening of the bond between the two oxygen atoms within the O2 molecule. Finally, in the oxyhemoglobin state at R = 1.84 Å, oxygen formed a sigma (σ) bond between the iron's dz² orbital and its own π* orbital and stabilized as a singlet (multiplicity 1). In short, the system's total spin multiplicity traced a path from the triplet (degenerate with the septet), through the quintet, to the singlet. ■ The Key That Unlocks the Forbidden Reaction: Spin Crossing Why this multi-step spin transition matters becomes clear from the activation-barrier analysis. When the researchers fixed the system's spin state as a septet, the activation barrier for oxygen binding was a substantial 0.82 eV. But when the system was allowed to cross from the septet to the singlet—spin crossing—the binding barrier fell sharply to 0.02 eV. A single spin crossing lowered the barrier roughly fortyfold. The spin transition, in other words, is not an obstacle blocking oxygen binding but rather the passage that makes the forbidden reaction possible. Instead of directly connecting two states of different total spin (triplet oxygen and the singlet complex), the system detours through intermediate high-spin states, bypassing the spin selection rule and finding a low-energy path. For reference, a minimum-energy-path calculation with the atomic positions fully optimized (CINEB) yielded a binding barrier of 0.38 eV and an oxygen-release barrier of 0.92 eV. The researchers concluded that this spin crossing is the key factor governing the activation barrier. ■ The Switch for Oxygen Affinity: Iron Out of the Plane The researchers identified one more important indicator: how far the iron atom sits out of the porphyrin plane (d). In the oxygen-free deoxy state the iron protruded 0.18 Å out of the plane, but in the oxygen-bound oxy state it settled almost within the plane, at 0.01 Å. This agrees well with the crystal structure determined by experiment. Behind this movement lies an interaction between orbitals. In the deoxy state, the iron's dxy orbital interacts antibondingly with the nitrogen atoms of the porphyrin, pushing the iron out of the plane. But as oxygen binds and the electron in the dxy orbital flips its spin and moves to the dyz orbital, the dxy orbital empties and this antibonding interaction vanishes. As a result, the iron is drawn back into the porphyrin plane. The researchers concluded that, together with the iron–oxygen distance (R), this iron out-of-plane distance (d) is one of the two key reaction coordinates controlling oxygen affinity. ■ Significance and Outlook The greatest significance of this study lies in its concrete explanation, in the language of quantum mechanics, of breathing—the most basic activity of life. Life performs the oxygen-binding reaction, forbidden under the spin selection rule, quickly and reversibly by way of a spin crossing that switches successively through several spin states. In a sense, we harness a quantum-mechanical spin transition with every breath. The work also points to potential applications. The lengthening of the bond between the two oxygen atoms during an intermediate stage of binding suggests that the FePIm system could function as a catalyst that splits the oxygen molecule. The researchers noted the possibility of using the system as a cathode-electrode catalyst in polymer electrolyte fuel cells (PEFCs), where the oxygen reduction reaction takes place, while also pointing out that the challenge of overcoming the high activation barrier accompanying the reaction remains. By confronting head-on how life resolves the forbidden reaction of triplet oxygen binding to the heme iron, this study offers a solid starting point for further discussion from the standpoint of the quantum mechanics of respiration. #QuantumBiology #Hemoglobin #Respiration #OxygenBinding #SpinCrossing #QuantumMechanics #Porphyrin #DFT #FuelCellCatalyst #TripletOxygen https://pubs.acs.org/doi/10.1021/acsomega.8b00879
Published in the Elsevier journal Plant Stress, this review synthesizes the field by extending the scope of plant quantum biology beyond the traditional territory of photosynthesis and magnetosensing to enzyme catalysis and stress responses (light, oxidative, temperature, and biotic stress). It offers a broad survey of how four quantum phenomena—quantum coherence, entanglement, the radical pair mechanism, and quantum tunneling—may be involved in light-harvesting efficiency, magnetic-field sensing, and enzyme reaction rates. It projects that understanding and controlling these quantum effects could be harnessed for sustainable agriculture, such as developing stress-tolerant crops, while also pointing to the challenges posed by biological complexity and experimental limitations. [Quantum Biology Society] Plant biology has traditionally explained stress responses in the language of classical physics and biochemistry. But as evidence accumulates that quantum phenomena once thought to be the exclusive province of the microscopic world are in fact involved in the activities of life, quantum biology—which explores what role quantum mechanics (QM) plays in core functions such as photosynthesis, light perception, and stress responses—is emerging as a new field. Concepts like superposition, entanglement, tunneling, and coherence are its central tools. A review recently published in the Elsevier journal Plant Stress, "Plant quantum biology: The quantum dimension of plant responses to stress," surveys this field broadly. Massimo E. Maffei of the University of Turin in Italy extends the scope of plant quantum biology—until now discussed largely in terms of photosynthesis and magnetosensing—to enzyme catalysis, stress responses, and, further still, agricultural applications. At the same time, the author is careful to note that the field is still young and that established evidence and theoretical hypotheses remain intermingled, drawing a cautious map of the terrain. ■ Photosynthesis: Quantum Coherence That Captures Light The area where the firmest evidence has accumulated in plant quantum biology is photosynthesis. Photosynthetic organisms convert the photons they absorb into chemical energy with almost no loss, achieving a quantum efficiency approaching 100%. The energy of a light-harvesting complex that has absorbed light is delivered to the reaction center within extraordinarily short times—femtoseconds to picoseconds—and this efficiency and speed are difficult to explain by classical physics alone. The phenomenon drawing attention here is quantum coherence. The excitation energy (exciton) generated by photon absorption is not trapped on a single pigment molecule but exists as a wave-like superposition spread across several pigments, so that it can explore multiple routes to the reaction center simultaneously. In the FMO complex of green sulfur bacteria, long-lived coherence persisting even at physiological temperatures has been observed by two-dimensional electronic spectroscopy (2DES), and the protein scaffold is thought to play a role in shielding this coherence from external disturbance. Quantum entanglement between pigments has also been proposed as a way to coordinate exciton movement and aid energy transfer, but direct evidence in photosynthetic systems is not yet as solid as that for coherence. Further, active debate continues over whether this coherence plays a functional role in genuinely improving energy-transfer efficiency or is merely an incidental byproduct of the structure, and over whether it is electronic coherence or vibronic (vibrational–electronic) coherence. On this point, the author presents both supportive and critical views in balance. ■ Magnetosensing: Radical Pairs That Read the Earth's Magnetic Field Plants respond even to fields as weak as the Earth's geomagnetic field, with effects on growth, development, circadian rhythms, and even the direction in which roots grow. The leading framework for explaining this magnetosensitivity is the radical pair mechanism (RPM). The central stage is cryptochrome, a blue-light photoreceptor. When the flavin (FAD) cofactor inside cryptochrome absorbs light and becomes reduced, it forms a radical pair with a neighboring tryptophan (a FAD radical and a tryptophan radical); the rate at which the spins of this radical pair oscillate between singlet and triplet states governs the outcome of the reaction and triggers downstream signaling. How can a magnetic field far weaker than thermal energy influence such a process? The answer lies in the fact that the interconversion between singlet and triplet is governed by electron spin, a purely quantum-mechanical property. Because of this, even a field as weak as the geomagnetic field can, through spin dynamics, alter the ratio of a chemical reaction's products. The author also discusses iron–sulfur (Fe–S) clusters as a potential magnetic-sensor candidate, while noting that direct experimental evidence supporting this in plants is still lacking. ■ Enzyme Catalysis: Quantum Tunneling Through the Barrier The third stage is the enzyme. In classical mechanics, a particle needs sufficient kinetic energy to surmount an energy barrier, but quantum tunneling allows a particle to pass through the barrier to the other side. Especially in reactions involving light particles such as hydrogen atoms, protons, or electrons, tunneling can substantially increase reaction rates. The clearest fingerprint of tunneling is the isotope effect. Because heavier isotopes tunnel less efficiently, reactions involving tunneling exhibit very large isotope effects, and their temperature dependence deviates from classical Arrhenius behavior. Enzymes are thought to raise the probability of tunneling by precisely arranging substrate and catalytic residues at the active site to lower and narrow the reaction's energy barrier. The author introduces attempts to boost, from a quantum standpoint, the efficiency of agriculturally important enzymes such as the carbon-fixation enzyme RuBisCO and nitrogenase, while making clear that such discussions confined to plants remain largely at the computational and theoretical level. ■ Stress Responses: The New Horizon This Review Opens The most original contribution of this paper is the way it connects the quantum phenomena above to plant stress responses. The author examines, in turn, the possibility of quantum effects intervening in four categories: light, oxidative, temperature, and biotic stress. For light stress, the key mechanisms are non-photochemical quenching (NPQ) and the xanthophyll cycle, which dissipate excess light energy as heat to prevent photodamage; here it is proposed that quantum coherence could help rapidly steer excess energy toward quenching sites, reducing the production of reactive oxygen species. For oxidative stress, given that scavenging reactive oxygen species (ROS) is a radical reaction involving unpaired electrons, the possibility is raised that the spin correlations of radical pairs could regulate the pathways and signaling of scavenging reactions. For temperature stress, the author offers the conjecture that quantum effects may be involved in protein folding and in the action of heat shock proteins and chaperones; for biotic stress, the hypothesis that tunneling could speed up the reactions of enzymes synthesizing defensive volatile organic compounds (VOCs) or phytoalexins. The author repeatedly emphasizes, however, that many of these links to stress are not yet established facts but promising hypotheses. Indeed, in the paper's summary schematic, the hypothetical connections to quantum effects are marked separately. ■ The Road to Agriculture, and the Challenges That Remain The author's interest in this field lies in its application potential. Possibilities raised include using magnetic-field treatments to regulate seed germination and growth; designing light-harvesting systems and enzymes on quantum principles to raise crops' photosynthetic efficiency and stress tolerance; and developing biological magnetic sensors that exploit cryptochromes. The author foresees particularly large potential for plant quantum biology as a strategy for creating resilient crops amid climate change. Yet the walls to be scaled are equally clear: the complexity of biological systems, the fleeting and fragile nature of quantum phenomena, and the experimental difficulty of directly observing and verifying these effects inside living cells. The author concludes that the field's next tasks are research that directly observes and manipulates quantum effects within living plants, and the development of robust theoretical models capable of predicting them. In synthesizing the whole of plant quantum biology—beyond isolated experimental cases—from the perspective of stress adaptation and sustainable agriculture, this review reads as a milestone bridging basic science and the agricultural field. #QuantumBiology #PlantScience #Photosynthesis #QuantumCoherence #RadicalPairMechanism #QuantumTunneling #Cryptochrome #Magnetosensing #SustainableAgriculture #StressTolerantCrops https://www.sciencedirect.com/science/article/pii/S2667064X25001988
Published in Scientific Reports (Nature Portfolio), this study extends inelastic electron tunneling spectroscopy (IETS)—originally proposed as a model for olfactory receptor activation—to the mammalian serotonin receptor (5-HT2A) through quantum-chemical modeling. It finds that several serotonin agonists, including LSD and DOI, share a common vibrational peak near 1500 cm⁻¹ whose intensity scales with the drug's potency, suggesting that the key to receptor activation may be not only a molecule's shape but its vibration. As a way to test this, it proposes deuterated versions of the LSD analogue DAM-57. The design—leaving the molecular shape almost untouched while altering only the vibration to check for a change in potency—could open a new path to computer-based potency prediction in drug discovery. [Quantum Biology Society] A large share of modern medicines target G protein-coupled receptors (GPCRs) on the cell surface. Yet how a drug (an agonist) switches such a receptor on—how it activates it—remains a fundamental question of pharmacology and drug design that is still not fully understood. The lock-and-key model, long used as the standard, explains a molecule's shape and binding but has been limited in predicting how strongly a drug acts (its potency). At the serotonin receptor, for instance, the two molecules DOI and DOB have almost the same binding affinity (docking) yet differ greatly in potency. Something beyond shape is clearly at work. A 2015 paper in the Nature Portfolio journal Scientific Reports, "Neuroreceptor Activation by Vibration-Assisted Tunneling," proposes a quantum-mechanical answer to this question. Ross D. Hoehn, David Nichols, and Sabre Kais of Purdue University, together with Hartmut Neven of Google, extended to the serotonin receptor a vibrational theory originally put forward to explain olfaction (the recognition of odorant molecules). The core idea is that a receptor is activated by reading not only the shape of the molecule it binds but also that molecule's characteristic vibration. ■ Beyond Shape: Vibration Opens a Channel for the Electron The roots of this theory lie in olfaction. The vibrational theory—that odor receptors sense the vibrations of odorant molecules—was once dismissed for lacking a clear mechanism, but it drew renewed attention when Luca Turin and others refined it into a physical mechanism resembling inelastic electron tunneling spectroscopy (IETS). Mapped onto a receptor, the mechanism runs as follows. The receptor's binding site is viewed as a single tunneling junction that an electron must cross, with specific amino acid residues forming the two walls of the junction as the electron donor and the electron acceptor. An electron cannot easily cross this gap on its own; but if it can hand off a packet of energy of exactly the right size to match a vibrational mode of the bound agonist, an inelastic channel opens through which the electron passes while exciting that vibration. The researchers propose that this very electron transfer is the trigger that switches the receptor on. The energy that drives the electron, they suggest, could be supplied by an ionic cofactor such as a calcium ion. The upshot is a picture in which each agonist's distinctive vibrational fingerprint, quite apart from its shape, takes part in receptor activation. ■ A Shared Peak at 1500 cm⁻¹, Marching in Step With Potency Using density functional theory (DFT) and normal-mode analysis, the researchers calculated the tunneling spectra of several 5-HT2A agonists. The subjects were hallucinogenic compounds including LSD and DOI, phenethylamines of the 2C-X class and amphetamines of the DOX class—many of them first characterized by the chemist Alexander Shulgin. The calculations showed that these agonists shared a common peak in one particular vibrational band, at 1500 cm⁻¹. More striking still, the intensity of this peak (the integral over the 1500 ± 35 cm⁻¹ range) tracked each drug's potency. Taking the most potent compound, LSD, as the reference, the peak intensity was roughly proportional to the inverse of the EC50—that is, to potency. The motions contributing to this band were stretching of the amide methyl hydrogens, stretching of the phenyl and indole hydrogens, and bending of the tertiary-amine methyl hydrogens. The potency difference between DOI and DOB—indistinguishable by shape alone—could, from this vibrational standpoint, finally begin to find an explanation. ■ Testing It With Deuterium: The Proposed DAM-57 Experiment To turn the theory into an experiment, the tool the researchers chose was deuterium. The target molecule was DAM-57 (lysergic acid dimethylamide), an analogue of LSD that carries a methyl group in place of LSD's flexible ethyl amide and is therefore far less potent. Deuterium is chemically almost identical to ordinary hydrogen, so it barely affects a molecule's shape or binding, but its mass is twice as great, which shifts vibrational frequencies. Substituting deuterium at specific positions therefore makes it possible to selectively lower the 1500 cm⁻¹ vibrational peak while leaving the shape intact. The researchers' prediction is clear: deuterating the amide side chain to deplete this peak should also reduce the compound's potency at the receptor. In the calculations, one substituted form (DAM-57-iv) showed its peak intensity cut to about one-third of the original and its tunneling probability density to roughly one-tenth, pointing to a steep drop in potency. Since binding and kinetic isotope effects alone rarely change potency by more than about 10%, a deuterium substitution that produces a much larger change would be strong evidence for the vibrational mechanism—a falsifiable prediction, in other words. ■ Significance, and a Note of Caution If this work is validated, it would not only supply a quantum-mechanical explanation for the biological phenomenon of receptor activation but could also become a new tool for predicting, by computer, the potency and activity of drugs that docking alone has struggled to capture. Its potential lies in broadening the perspective of drug design from shape-matching to vibration-reading. There are, however, clear reasons for caution. This is a computational and theoretical study, and the correlation between peak intensity and potency is a broad trend observed in a limited number of molecules. Above all, the olfactory vibrational theory at the root of this approach remains contested. In odor perception, shape-based explanations are the mainstream, and experiments on whether humans can distinguish deuterated molecules by smell have yielded conflicting results. The DAM-57 experiment the authors propose was, as of this paper, still an untested prediction. This study is therefore best read not as an established mechanism but as a provocative and testable hypothesis equipped with a clear path to verification. In treating the activation of neurotransmitter and drug receptors through quantum vibration-assisted tunneling—unlike the existing olfaction (odorant-vibration) entries—this paper adds a pharmacological perspective that the archive had not previously held. #QuantumBiology #QuantumTunneling #Neuroscience #SerotoninReceptor #DrugDiscovery #VibrationalTheory #Olfaction #GPCR #LSD #DeuteriumSubstitution https://www.nature.com/articles/srep09990
Published in PNAS (Proceedings of the National Academy of Sciences), this study uses multiscale simulation to elucidate a key step in the long-range radical transport—spanning roughly 32 Å—in ribonucleotide reductase (RNR), the essential enzyme that produces DNA's raw materials. It shows that radical transfer from a tryptophan (W48) to a tyrosine (Y356) occurs through orthogonal PCET—in which the electron and proton move together but in different directions—and newly proposes that the proton acceptor is the glutamate residue E52. A conformational change in Y356 acts as a gatekeeper that opens the door to the reaction, and this motion shortens the distance so that the proton's hydrogen tunneling can occur efficiently—a case in which classical protein motion and quantum tunneling operate hand in hand. [Quantum Biology Society] Every cell in our body must be continuously supplied with deoxyribonucleotides—their raw materials—in order to build and repair DNA. The essential enzyme that produces these materials is ribonucleotide reductase (RNR), which is also an important target for antibiotic and anticancer drug development. Yet for this enzyme to begin its reaction, something remarkable must happen. The radical that serves as the reaction's trigger must travel a great distance—about 32 angstroms (Å)—across two subunits (α and β) to reach the active site where catalysis takes place. This long-range radical transport proceeds through a series of proton-coupled electron transfer (PCET) reactions, along a pathway of redox-active amino acid residues lined up like a chain. A study recently published in the Proceedings of the National Academy of Sciences (PNAS), "Conformationally Gated Multisite Proton-Coupled Electron Transfer in the Ribonucleotide Reductase β Subunit," has elucidated a key step in this pathway that had until now been poorly understood. Jiahua Deng of Princeton University and Sharon Hammes-Schiffer, an authority on PCET theory, used multiscale simulations combining several computational methods to track, at the atomic level, how the radical is passed from the tryptophan W48 to the tyrosine Y356 within the β subunit. At the heart of that process lay a conformational change in the protein and the quantum tunneling of a proton. ■ A Radical That Crosses 32 Å, and PCET PCET is a reaction in which the electron and proton move not separately but together, simultaneously, without forming a stable intermediate. In RNR, the radical starts from the tyrosine Y122 in the β subunit and is passed along a chain of residues—W48, Y356, and then Y731 and Y730 in the α subunit—to the cysteine C439 at the active site. This pathway has a different character in each segment. Within the α subunit, collinear PCET occurs, in which the electron and proton move in the same direction; this portion has been relatively well studied. Within the β subunit, by contrast, orthogonal PCET occurs, in which the electron and proton split off and move in different directions—a process that has remained poorly understood because the pathway is complex and theoretically difficult to treat. It is precisely this orthogonal PCET step, from W48 to Y356 in the β subunit, that the present study dug into. ■ The Orthogonal PCET Where Electron and Proton Split, With E52 as the Proton Acceptor The simulations showed that radical transfer from W48 to Y356 was thermodynamically favorable (reaction free energy of about −1.4 kcal/mol). The mechanism runs as follows. As the electron on Y356 moves to W48, which is in the cationic radical state, the proton released by Y356 moves to a glutamate residue, E52, located on an entirely different side. The electron and proton split off in different directions and move cooperatively. The spin densities before and after the reaction show the radical moving cleanly from W48 to Y356, matching this orthogonal PCET picture exactly. What is especially noteworthy here is the identity of the partner that receives the proton—the proton acceptor. Until now, experiments (the finding that replacing E52 with glutamine abolishes the enzyme's function) and structural information had been interpreted to mean that E52, as part of a water channel, indirectly regulates Y356's proton. But this simulation offers an alternative: that E52 is the direct partner that receives Y356's proton. The evidence is the change in distance. Before W48 was oxidized, the most stable distance between Y356 and E52 was about 6.6 Å, but once W48 was oxidized, the most stable distance narrowed sharply to about 2.6 Å—close enough for the proton to cross directly. ■ Conformational Change as Gatekeeper, and Hydrogen Tunneling Behind this change in distance lies a dramatic conformational change in Y356. Y356 sits on a flexible loop at the α/β interface. Before W48 is oxidized, it is held by an arginine residue, R236, and points in a particular direction; but when W48 is oxidized, a positive charge appears, water floods into the surroundings, and space opens up. As a result, Y356 is released from R236 and changes direction—first turning toward E52 to hand off its proton, then turning toward Y731 in the α subunit to prepare for the next radical transfer. In this way, Y356's motion serves as a gate that determines when, and in which direction, the reaction proceeds. And it is precisely here that quantum mechanics enters. In PCET, the proton does not classically climb over the barrier but moves by hydrogen tunneling, piercing through it. When the researchers analyzed the reaction with vibronically nonadiabatic PCET theory, they found that the reaction rate was extremely sensitive to the distance between the proton donor and the acceptor. The shorter the distance, the more strongly the proton's wavefunctions overlapped, and the more sharply tunneling occurred. The equilibrium donor–acceptor distance was about 2.61 Å, but the distance at which the reaction actually occurs most often was shorter still, about 2.52 Å. In other words, hydrogen tunneling occurs efficiently only when the protein's conformation, fluctuating from moment to moment, produces such short distances (estimated rate constant of about 1.6 × 10⁷ s⁻¹). Classical protein motion, so to speak, sets the stage for quantum tunneling. The researchers also confirmed that W48 could become a neutral radical by handing its proton to a nearby aspartate, D237; but weighing several considerations, they concluded that PCET to Y356 occurs mainly when W48 is in the cationic radical state. The cationic radical is a stronger oxidant and more readily produces a conformation favorable for radical transfer. ■ Significance and Outlook This study is meaningful on two levels. First, because RNR is a major target for anticancer and antibiotic drugs, understanding its radical-transport mechanism at the atomic level offers leads for drug design and protein engineering. More broadly, it demonstrates general principles for how an enzyme precisely coordinates the movement of electrons and protons across long distances—the local rearrangement of hydrogen bonds, hydration by water, conformational gating, and quantum hydrogen tunneling all interlocking to jointly control the reaction's reactivity and directionality. There are, of course, points to view with caution. This is a computational and simulation-based study, and the authors themselves note that current methods cannot accurately obtain the absolute energy values for RNR reactions, so the results should be regarded as qualitative insights. The proposal that E52 is the direct proton acceptor, as well as W48's involvement, has not yet been confirmed by direct experimental evidence, and these results concern forward radical transfer. Even so—unlike existing entries dealing with DNA-repair enzymes or electron transport—this paper, as a 2026 study, elucidates at the atomic level the long-range radical transport of an enzyme that builds DNA's raw materials, from the standpoint of quantum hydrogen tunneling, adding a new texture to the archive. #QuantumBiology #ProtonCoupledElectronTransfer #RibonucleotideReductase #HydrogenTunneling #EnzymeCatalysis #RadicalTransport #DNASynthesis #QuantumTunneling #MultiscaleSimulation #DrugTarget https://pmc.ncbi.nlm.nih.gov/articles/PMC12867644/
Published in PNAS, this study uses combined quantum-mechanical/molecular-mechanical (QM/MM) calculations and semiclassical quantum dynamics to show that the hydrogen-transfer reaction of the vitamin B12 (coenzyme B12)–dependent enzyme methylmalonyl-CoA mutase proceeds by quantum tunneling. It explains the enzyme's very large kinetic isotope effect (KIE ≈ 50) through multidimensional corner-cutting tunneling, with the calculated value (≈ 51) in excellent agreement with the experimental value (49.9). It shows that the large KIE arises not because the energy barrier is unusually thin, but because the light hydrogen cuts across the corner of the barrier, taking a shortcut that shortens the tunneling distance. [Quantum Biology Society] Our metabolism relies on enzymes that use vitamin B12 as a coenzyme. Among them, methylmalonyl-CoA mutase (MMCM) is the only B12-dependent isomerase found in both mammals and bacteria; it converts methylmalonyl-CoA into succinyl-CoA, which can then enter the cell's energy-metabolism cycle (the Krebs cycle). At the heart of this enzyme lies a cobalt–carbon (Co–C) bond, a rarity in nature. When this bond breaks homolytically, it generates a highly reactive radical that abstracts a single hydrogen atom from the substrate—and it is at this hydrogen-transfer step that something strange was observed. Replacing the hydrogen with its heavy isotope, deuterium, slowed the reaction by a remarkable factor of about 50. Such a giant kinetic isotope effect (KIE), inexplicable by classical chemistry, is a powerful signature of quantum tunneling. A study published in the Proceedings of the National Academy of Sciences (PNAS), "Coupling of Hydrogenic Tunneling to Active-Site Motion in the Hydrogen Radical Transfer Catalyzed by a Coenzyme B12-Dependent Mutase," solved this puzzle at the atomic level. Agnieszka Dybala-Defratyka and Piotr Paneth of the Technical University of Lodz in Poland, Ruma Banerjee of the University of Nebraska, and Donald G. Truhlar of the University of Minnesota—a leading figure in transition-state theory and tunneling research—used combined quantum-mechanical/molecular-mechanical (QM/MM) calculations and semiclassical quantum dynamics to reveal the origin of this giant isotope effect. The key was shortcut tunneling, in which the hydrogen cuts across the corner of the energy barrier. ■ The Cobalt–Carbon Bond of Vitamin B12, and the Radical Coenzyme B12, or adenosylcobalamin (AdoCbl), contains a cobalt–carbon bond that is uncommon in nature. With the substrate bound, MMCM accelerates the homolytic cleavage (homolysis) of this Co–C bond by a factor of about 10¹¹ relative to the uncatalyzed rate in solution. When the bond breaks in this way, it produces a highly reactive radical known as the deoxyadenosyl radical (dAdo•). This radical immediately abstracts a single hydrogen atom from the methyl group of the substrate (methylmalonyl-CoA). This is the key hydrogen-transfer step that sets the isomerization reaction in motion, and it is the focus of the present study. And it is precisely this step that exhibits the unusually large isotope effect of about 50. ■ A 50-Fold Isotope Effect, the Fingerprint of Tunneling The kinetic isotope effect (KIE) measures how much a reaction slows when the participating hydrogen is replaced by heavy deuterium. If the reaction proceeds by classically climbing over the barrier, this value is not very large. But because light hydrogen tunnels through a barrier far more readily than heavy deuterium, the KIE becomes very large in reactions dominated by tunneling. A giant KIE, in other words, is a fingerprint that tunneling is at work. The researchers' calculations bear this out. Without accounting for tunneling, the calculated KIE was only 14.3, far short of the experimental value of 49.9. But once tunneling was properly included, the calculated value matched experiment almost perfectly. Taking multidimensional tunneling into account raised the KIE by a factor of 3.6, from 14 to 51—a value in excellent agreement with experiment. ■ The Discovery of Corner-Cutting Tunneling So how, exactly, does the tunneling occur? A chemical reaction can be likened to a journey from a reactant valley to a product valley over a ridge (the energy barrier). The lowest mountain pass (the minimum energy path) curves gently as it goes through the saddle point. But a tunneling particle need not follow this curving pass exactly. It can cut across the corner of the mountain and pierce through by a shorter route. This shortcut does not pass through the saddle point, so its barrier is somewhat higher—but the distance is shorter. Because tunneling probability is exponentially sensitive to distance, tunneling actually occurs far more readily when the distance shortens, even if the barrier rises somewhat. The calculations show the importance of this corner-cutting vividly. In a model that tunnels straight along the curving pass (ZCT), the KIE stayed at 22, but allowing a slight cutting of the corner (SCT) nearly doubled the value to 44, and the models that allowed the greatest corner-cutting (LCT and OMT) reached about 51, matching the experimental value. From this the researchers drew an important conclusion: the giant KIE arises not because the barrier is unusually thin, but because corner-cutting tunneling shortens the distance the system must tunnel through without a comparable increase in either the effective barrier or the effective mass for tunneling. Moreover, because light hydrogen exploits this shortcut more aggressively than heavy deuterium does, the difference between the two isotopes (the KIE) widens further. Here the coupling to active-site motion in the paper's title comes into view. This shortcut is created not by the motion of the single transferred hydrogen alone, but by the coordinated motion of many atoms in the active site, including the carbon atoms that donate and accept the hydrogen. In other words, the hydrogen's quantum tunneling occurs in concert with the motion of the active site. ■ Significance and Outlook The strength of this study lies in how precisely the calculations reproduced experiment. Because the computed isotope effect agrees with the experimental value within error, it lends strong confidence to the corner-cutting tunneling interpretation of the mechanism. This suggests that quantum tunneling may be a common catalytic strategy in the hydrogen transfer of radicals generated by homolysis of the Co–C bond, and more broadly in the many enzymes that shuttle radicals from place to place. It is worth remembering, of course, that this study is a computational model based on semiclassical approximations, and that real tunneling occurs not along a single path but along a distribution of many paths. Even so—unlike the archive's other entries on enzyme tunneling—this paper stands as the first to treat the radical chemistry of vitamin B12 (cobalamin), a biological organometallic coenzyme, and reads as a well-regarded example of multidimensional quantum-tunneling research, showing in unprecedented detail the character of such tunneling inside an enzyme. #QuantumBiology #QuantumTunneling #VitaminB12 #EnzymeCatalysis #IsotopeEffect #HydrogenTransfer #CoenzymeB12 #RadicalChemistry #QMMM #Metabolism https://pmc.ncbi.nlm.nih.gov/articles/PMC1904141/
Published in JACS: molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) calculations pin down the origin of the counterintuitive isotope effects shown by cytochrome P450 and its functionally analogous enzyme TauD P450 achieves high reactivity without quantum tunneling, and the researchers trace the secret to the local electric field (LEF) generated by the protein, which lowers and broadens the reaction barrier; TauD, by contrast, tunnels straight through a high barrier The work overturns the common assumption that enzymes accelerate reactions through quantum tunneling, showing instead that nature splits the labor between two strategies, electric fields and tunneling, with direct relevance to drug-metabolism research [Quantum Biology Society] A widely accepted tenet in quantum biology holds that enzymes speed up their reactions by exploiting quantum tunneling. The prime piece of evidence cited for this is a large "kinetic isotope effect" (KIE). Yet a puzzle sits at the center of that picture. Cytochrome P450, the workhorse enzyme responsible for much of how our bodies metabolize drugs and xenobiotics, shows only a small isotope effect, as if it barely tunnels at all. This is striking, because when P450's active species is taken out of the protein and run in solution, it displays a large isotope effect, that is, pronounced tunneling. So why does the P450 protein suppress tunneling? And how does it still maintain such high reactivity? A 2025 paper in the Journal of the American Chemical Society (JACS), "Local Electric Fields Originate Unusual Kinetic Isotope Effects in the Hydrogen Abstraction Reactions of the Functionally Analogous P450 and TauD Enzymes," offers a clear answer to this long-standing riddle. The Hebrew University of Jerusalem team of Surajit Kalita, David Danovich, and Sason Shaik (a leading authority on the theory of P450 reactivity) used MD simulations and QM/MM calculations to show that the answer lies in the local electric field (LEF) the protein generates. In short, P450 lowers its barrier with an electric field, while TauD tunnels through the barrier. ■ The Puzzle: Why P450 Bears No Fingerprint of Tunneling The kinetic isotope effect (KIE) measures how much a reaction slows down when the reacting hydrogen is swapped for its heavier isotope, deuterium. Because a light hydrogen penetrates a reaction barrier far more readily than a heavy deuterium does, a large KIE is usually read as the fingerprint of quantum tunneling. By this measure, the two enzymes behave in opposite ways. Heme-containing P450 and the nonheme iron enzyme TauD both carry out hydrogen abstraction, using a high-valent iron-oxo active species to pull a hydrogen off a substrate's carbon-hydrogen bond. Yet P450's KIE is very small (about 1.2 for the substrate camphor and about 7 for p-xylene), whereas TauD's KIE is large, around 58. What makes this intriguing is that when essentially the same active species P450 uses is reacted in solution, without the protein, its KIE jumps to about 47. In other words, P450's active species is perfectly capable of tunneling on its own, but that tunneling vanishes once it is placed inside the protein. Something is strongly suppressing it. ■ The Key Is the Local Electric Field: Lowering and Broadening the Barrier The researchers' QM/MM calculations accurately reproduced the experimental values measured inside the protein: a low KIE for P450 (about 5 to 6) and a high KIE for TauD (a calculated 62 against an experimental 58). But in a computational experiment that stripped the protein away and modeled only the reactive core, P450's KIE shot up to roughly 36 to 81, direct evidence that the protein itself had been suppressing tunneling. The culprit behind that suppression turned out to be the local electric field. A protein's folded structure generates a strong electric field at the active site, and the role such fields play in enzyme catalysis was first proposed on theoretical grounds by Arieh Warshel, a Nobel laureate in chemistry, and later confirmed experimentally by Steven Boxer's group using vibrational Stark spectroscopy. In P450, this field stabilizes the transition state more than the reactant, lowering the reaction barrier and, at the same time, broadening it. And a broader barrier physically reduces the probability of tunneling. The net result is that P450 uses the field to lower its barrier and accelerate the reaction classically; as the barrier widens in the process, tunneling fades away and a low KIE emerges. ■ TauD Tunnels Through: The Contrasting Strategy TauD, by contrast, takes the opposite route. To begin with, its hydrogen-abstraction barrier is about 27 kcal/mol, more than 10 kcal/mol higher than P450's 13 to 18 kcal/mol. On top of that, TauD's local electric field does the reverse of P450's: it stabilizes the reactant more than the transition state, which raises the barrier and narrows it. A barrier narrowed in this way is highly favorable for quantum tunneling. In short, TauD cannot use its field to lower the barrier, so instead it drives straight through a high, narrow barrier by tunneling, and a large KIE results. Indeed, the calculated width of TauD's barrier (about 1.1 Å) is comparable to the de Broglie wavelength of a hydrogen atom (about 1.45 Å), just the right conditions for tunneling to occur. This difference grows even more dramatic as the temperature drops. Under the deep cold of 200 K, where thermal energy is too scarce to clear the barrier classically, TauD's KIE soars to around 14,000, while P450's stays at roughly 600 to 1,600. The fundamental gap between an enzyme that leans on tunneling and one that does not becomes ever sharper as the temperature falls. ■ Significance and Outlook: Overturning the Conventional Wisdom on Enzyme Reactions The greatest significance of this work is that it overturns the widely held narrative that enzymes accelerate their reactions through quantum tunneling. Living systems, it turns out, deploy at least two strategies, choosing between them as circumstances demand. One is the classical "electric strategy," like P450's, which lowers the barrier with the protein's electric field; the other is the "quantum strategy," like TauD's, which drives through the barrier by tunneling. That two functionally very similar enzymes should adopt opposite mechanisms suggests that nature has no single way of tuning reactivity. Because P450 in particular is a central enzyme in modern drug metabolism, a deeper understanding of this mechanism is expected to offer new leads for pharmacology and for enzyme engineering, including the design of electric fields. It should be kept in mind, of course, that this study rests on computational chemistry. The KIE values at very low temperatures and the like remain predictions that have not yet been cross-checked by experiment. Even so, the fact that the KIEs calculated in the protein environment line up precisely with existing experimental values lends the study's interpretation considerable weight. Beyond unraveling a secret of the P450 family that the very peculiarity of these enzymes had left unresolved in earlier quantum-biology discussions, the paper adds an important counterweight to the field's narrative by demonstrating that quantum tunneling is not the universal acceleration strategy of every enzyme, and that a protein can instead suppress it and actively harness an electric field. #QuantumBiology #CytochromeP450 #TauDEnzyme #KineticIsotopeEffect #QuantumTunneling #LocalElectricField #EnzymeReactions #ComputationalChemistry #MolecularDynamics #KoreanSocietyForQuantumBiology https://pmc.ncbi.nlm.nih.gov/articles/PMC12498400/
An electronic-level mechanism showing that when the photosynthetic water-oxidizing complex (WOC) turns two water molecules into oxygen, it clears the trickiest step, the first one-electron oxidation, by means of two spin crossovers Rather than a free oxygen radical, the complex forms an [O5O6]3- ion stabilized antiferromagnetically by its manganese (Mn) ions, allowing O-O bond formation to be driven even with photosystem II's limited oxidizing power (about 1 V) The work resolves a long-standing mismatch between XFEL crystallographic models and EPR spectroscopic data with a model of dynamic equilibrium between an S=3 form and an S=6 form, putting it on firm footing [Quantum Biology Society] Every oxygen molecule we breathe is produced when two water molecules are split inside the photosystem II protein complex of higher plants, algae, and cyanobacteria. The catalyst that drives this reaction is a manganese-calcium cluster that evolved some 3 billion years ago, known as the water-oxidizing complex (WOC). The trouble is that oxidizing water to oxygen is chemically very demanding. Four protons and four electrons must be stripped from two water molecules and an oxygen-oxygen (O-O) bond formed, and the very first one-electron oxidation, which generates an oxygen radical, is known to require a reduction potential of at least 2 V. Yet all the oxidizing power photosystem II can muster at this step is the roughly 1 V supplied by a nearby tyrosyl radical. So how does nature bridge this enormous energy gap? Felix Rummel and Patrick J. O'Malley of the Department of Chemistry at the University of Manchester report a computational-chemistry answer to this question in the American Chemical Society journal The Journal of Physical Chemistry B. Combining broken symmetry density functional theory (broken symmetry DFT) calculations with electron paramagnetic resonance (EPR) analysis, the researchers took a close look at the electronic structure of the S3 state, the stage just before oxygen is released, and traced the electronic pathway along which the O-O bond forms. They found a mechanism in which two spin crossovers, arising from the interplay of the WOC's distinctive geometry and magnetism, open a unique low-energy route to O-O bond formation. ■ The Water-Splitting Clock and the Highest Energy Threshold Water splitting in photosynthesis does not happen all at once. Each time it absorbs light, photosystem II accumulates one oxidizing equivalent, cycling through five states from S0 to S4 in what is called the Kok cycle; only when all four oxidizing equivalents have been gathered does it release one oxygen molecule from two water molecules. The S3 state this study focuses on is the stage immediately before that release, the penultimate step. The fundamental reason water oxidation is so hard lies in removing the first electron. Of the full four-step process of pulling electrons off one at a time, the step that strips the first electron to form an oxyl radical poses the highest energy barrier: its reduction potential is estimated to exceed 2 V, whereas the oxidizing power available to photosystem II is only the roughly 1 V mentioned above. Where artificial water-oxidation catalysts typically enlist powerful oxidants to manufacture extremely reactive oxygen species, nature carries out the same reaction smoothly with far weaker oxidizing power. Uncovering that mystery at the electronic level is the heart of this work. ■ Not a Free Radical, but a Controlled Ion Held by the Protein The crux of the answer the researchers propose is that nature does not leave the product of that first one-electron oxidation as a free oxygen radical with runaway reactivity. Instead, it captures the species as an ion complex of the form [O5O6]3-, stably lowering the system's energy. Here O5 and O6 denote the two oxygen atoms derived from water (O6 is the oxygen newly detected by XFEL after the second flash), and a two-center one-electron bond, a bond held together by just a single electron, begins to form between them. One can picture it as a peculiar state in which the two oxygen atoms are only just catching each other's edges, before they have bonded fully. What allows this transitional bond to hold rather than collapse is the magnetism inside the cluster. The spin of the unpaired electron on [O5O6]3- is stabilized through antiferromagnetic coupling, in which it pairs in the opposite direction to the spins of the neighboring manganese (Mn) ions, much as alternating the north and south poles of magnets locks a structure firmly in place. The paper notes that although this species was previously called an "O5 oxo-O6 oxyl" form, describing it as [O5O6]³⁻ is physically more accurate, given that negative spin density is present on both O5 and O6. ■ The Low-Energy Detour Engineered by Two Spin Crossovers The researchers simulated how the electronic structure changes as they gradually shortened the distance between the two oxygen atoms (O5-O6). Over the full path, they found that the system's total spin state switches twice, a phenomenon known as a spin crossover. A spin crossover is a rearrangement of the electron spins across the whole system that changes its total spin value; it can be likened to turning your body to slip through a narrow doorway with the least resistance, because when the spin flips at just the right moment it sharply lowers the intrinsic energy threshold. According to the calculations, when the O5-O6 distance is in the range of 2.5 to 2.1 Å, the most stable structure is an oxo-hydroxo form (S=3) in which O6 carries a hydrogen atom. But the moment the distance reaches 2.1 Å, the first spin crossover occurs and the system passes into an S=6 form, which remains lowest in energy down to about 1.65 Å, where a second spin crossover leads finally to a peroxo structure. The agents that drive these two crossovers are specific manganese ions within the cluster (Mn1 and Mn4), which, by flipping their own spins at the right moments, help the O-O bond form along a low energy barrier. In short, the WOC's precise geometry and magnetism mesh like gears to open a low-energy detour that lets oxygen bonding begin without any powerful oxidant. ■ A Precise Fit Between the Computational Model and the Experimental Data This computational model carries real weight because it fits neatly with several independent lines of experimental data. First, the key bond distances of the lowest-energy structure (S=6) obtained from the calculations agree closely with the latest X-ray free-electron laser (XFEL) crystallography data. The O5-O6 distances reported for the S3 state across various XFEL studies fall in the range of 1.5 to 2.1 Å, which experimentally rules out a classical nonbonded oxo-hydroxo form (which would require a separation of at least about 2.5 Å). Second, the model cleanly resolves a long-standing contradiction between structural crystallography and electron paramagnetic resonance (EPR) spectroscopy. The signal seen by EPR had pointed to a stable S=3 form, while the XFEL structure showed a form in which bonding had already begun, leaving a puzzle for the field. The researchers concluded that the two forms, the S=3 oxo-hydroxo and the S=6 [O5O6]3-, sit in a dynamic equilibrium set by the protonation state of O6. The S=6 form in particular gives a comparatively weak EPR signal that is easily hidden beneath the S=3 signal, and the team showed that simulating with an S=6 component of about 70% best matches the actual experimental EPR spectrum. The change in manganese oxidation observed by X-ray emission spectroscopy (XES), about 30% during the S2-to-S3 transition, likewise agrees with what the equilibrium model predicts. Further, the fact that the most recent XFEL structures place O6 very close to a neighboring amino acid (Glu189) suggests that this dynamic equilibrium is finely maintained through proton sharing between the two atoms. ■ Significance and Outlook: Imitating Nature's Design Principles The greatest significance of this work is that it demonstrates, clearly and at the electronic level, that nature's water-splitting catalyst is designed not to force the reaction with brute oxidizing power but to lower the energy barrier by using its distinctive magnetism to hold a hard-to-control intermediate steady. The two spin crossovers and the antiferromagnetic stabilization that unfold inside the protein are seen as an innovative set of bio-inspired design principles that could serve as a compass for building next-generation artificial-photosynthesis systems and high-efficiency water-splitting catalysts. That said, a few scientific caveats should be kept in mind when interpreting these results. First, this paper is not a new experimental discovery but a reinterpretation and modeling of existing experimental data through broken symmetry DFT calculations. Its strong agreement with a range of experimental data is a powerful argument, yet it still carries the inherent limitations of a single computational model. Second, several competing hypotheses coexist in the field for the mechanism of water oxidation, such as water nucleophilic attack and oxyl-oxo coupling, and this paper refines one model in the "dynamic equilibrium and low-barrier O-O bond" family by a step. Finally, the downstream route after the S3 stage, running from peroxo through superoxo to the release of triplet O2, is a region extrapolated from the S3 calculations and so should be regarded as a relatively tentative proposal. #QuantumBiology #Photosynthesis #PhotosystemII #WaterOxidizingComplex #OxygenEvolvingComplex #OEC #SpinCrossover #AntiferromagneticCoupling #WaterSplitting #ArtificialPhotosynthesis https://pmc.ncbi.nlm.nih.gov/articles/PMC9589598/
Skala Bünte, Süki Vagonu Hallē [2026.07.08.] Koncerta beigu telefona foto/ video. SKALA BÜNTE X SÜKI FACE2FACE https://fb.me/e/7dycfN2gI Details Event by John Dow Vagonu Hall Public · Anyone on or off Facebook 8TH OF JULY VAGONU HALLE TWO BANDS TWO BACKLINES MOSHPIT IN THE MIDDLE ONCE IN A LIFETIME FACE2FACE MASSACRE PROVIDED BY SKALA BÜNTE & SÜKI 🔪🔪🔪 DOORS 19:00 7€
Блінцов, Володимир · Алоба, Лео Тосин · Надточий, Анатолій · et al.
2 files · 4.5 MB · jpeg, pdfdeclared
У монографії викладено загальні відомості про автономні ненаселені підводні апарати, які призначені для групового застосування при виконанні спільних підводних місій пошукового та природоохоронного спрямування. Наведено відомості про способи організації керування групою апаратів та методи дослідження їх систем автоматичного керування. Розглянуті задачі автоматизації керування безекіпажним надводним судном як носієм групи автономних ненаселених підводних апаратів. Для наукових співробітників, спеціалістів, аспірантів та студентів вищих навчальних закладів, які досліджують, проектують та вивчають засоби підводної робототехніки.
Блінцов, Володимир · Сірівчук, Андрій · Надточий, Анатолій · et al.
2 files · 5.2 MB · jpeg, pdfdeclared
У монографії викладено загальні відомості про автономні ненаселені підводні апарати, які мають у своєму складі буксирувані радіобуї для оперативного зв'язку з береговим центром керування. Наведено відомості про математичне моделювання системи «автономний ненаселений підводний апарат - кабель-буксир - радіобуй» та описано результати синтезу їх систем автоматичного керування. Для наукових співробітників, спеціалістів, аспірантів та студентів вищих навчальних закладів, які досліджують, проектують та вивчають засоби підводної робототехніки.