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Ice XIX and ice XV are both partly hydrogen-ordered counterparts to disordered ice VI. The ice XIX → XV transition represents the only order-to-order transition in ice physics. Using Raman and dielectric spectroscopies, we investigate the ambient-pressure kinetics of the two individual steps in this transition in real time (of hours), that is, ice XIX → transient ice VI (the latter called VI‡) and ice VI‡ → ice XV. Hydrogen-disordered ice VI‡ appears intermittent between 101 and 120 K, as inferred from the appearance and subsequent disappearance of the ice VI Raman marker bands. A comparison of the rate constants for the H2O ices reported here with those from D2O samples [Thoeny et al., J. Chem. Phys. 156, 154507 (2022)] reveals a large kinetic isotope effect for the ice XIX decay, but a much smaller one for the ice XV buildup. An enhancement of the classical overbarrier rate through quantum tunneling for the former can provide a possible explanation for this finding. The activation barriers for both transitions are in the 18–24 kJ/mol range, which corresponds to the energy required to break a single hydrogen bond. These barriers do not show an H/D isotope effect and are the same, no matter whether they are derived from Raman scattering or from dielectric spectroscopy. These findings favor the notion that a dipolar reorientation, involving the breakage of a hydrogen bond, is the rate determining step at the order-to-order transition. [ABSTRACT FROM AUTHOR]

A simple phenomenological thermodynamic model is developed to describe the chemical bonding and unbonding in homonuclear diatomic systems. This model describes the entire phase diagram of dimer-forming systems and shows a transition from monomers to dimers, with monomers favored at both very low and very high pressures, as well as at high temperatures. In the context of hydrogen, the former region corresponds to hydrogen present in most interstellar gas clouds, while the latter is associated with the long sought-after fluid metallic phase. The model predicts a molecular to atomic fluid transition in dense deuterium, which is in agreement with recently reported experimental measurements. [ABSTRACT FROM AUTHOR]

Fe, Cr, and W are important elements in the alloys of in-reactor materials and operate in high-temperature environments with thermal expansion. Their tritium-impeding abilities are crucial to the radiation safety of various nuclear reactors. In this study, first-principles density functional theory is combined with quasi-harmonic approximation to evaluate factors that can affect the interstitial formation energy and diffusion coefficient of hydrogen isotopes in body-centered cubic (BCC) Fe, Cr, and W, including thermal expansion, metal host lattice vibrations, phonon density-of-states (pDOS) coupling diffusing atoms, and isotope effects. Calculation results indicate that the interstitial formation energy decreases as lattice expansion increases, whereas the jump barriers remain almost constant. Thermal expansion, host lattice vibration, and pDOS coupling minimally affect the diffusion coefficients of hydrogen isotopes in Fe, Cr, and W. The diffusion coefficient ratios between hydrogen isotopes are higher than the inverse ratio of the square root of the isotope mass at low temperatures. However, they decrease to the inverse ratio of the square root of the isotope mass at temperatures exceeding 800 K. This study comprehensively investigates factors that affect the diffusion coefficients of hydrogen isotopes in BCC Fe, Cr, and W, thus providing a firm theoretical foundation for predicting the diffusion coefficients of tritium at different temperatures using protium/deuterium diffusion coefficients. [ABSTRACT FROM AUTHOR]

This work presents systematic comparisons between classical molecular dynamics (cMD) and quantum dynamics (QD) simulations of 15-dimensional and 75-dimensional models in their description of H atom scattering from graphene. We use an experimentally validated full-dimensional neural network potential energy surface of a hydrogen atom interacting with a large cell of graphene containing 24 carbon atoms. For quantum dynamics simulations, we apply Monte Carlo canonical polyadic decomposition to transform the original potential energy surface (PES) into a sum of products form and use the multi-layer multi-configuration time-dependent Hartree method to simulate the quantum scattering of a hydrogen or deuterium atom with an initial kinetic energy of 1.96 or 0.96 eV and an incident angle of 0°, i.e., perpendicular to the graphene surface. The cMD and QD initial conditions have been carefully chosen in order to be as close as possible. Our results show little differences between cMD and QD simulations when the incident energy of the H atom is equal to 1.96 eV. However, a large difference in sticking probability is observed when the incident energy of the H atom is equal to 0.96 eV, indicating the predominance of quantum effects. To the best of our knowledge, our work provides the first benchmark of quantum against classical simulations for a system of this size with a realistic PES. Additionally, new projectors are implemented in the Heidelberg multi-configuration time-dependent Hartree package for the calculation of the atom scattering energy transfer distribution as a function of outgoing angles. [ABSTRACT FROM AUTHOR]

Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time-m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral libraries and challenging in silico fragmentation software. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) may offer an additional layer of structural information in untargeted metabolomics, especially for identifying specific unidentified metabolites that are revealed to be statistically significant. Here, we investigate the potential of hydrophilic interaction liquid chromatography (HILIC)-HDX-MS in untargeted metabolomics. Specifically, we evaluate the effectiveness of two approaches using hypothetical targets: the post-column addition of deuterium oxide (D2O) and the on-column HILIC-HDX-MS method. To illustrate the practical application of HILIC-HDX-MS, we apply this methodology using the in silico fragmentation software MS-FINDER to an unknown compound detected in various biological samples, including plasma, serum, tissues, and feces during HILIC-MS profiling, subsequently identified as N1-acetylspermidine.

Elucidating the phase diagram of solid hydrogen is a key objective in condensed matter physics. Several decades ago, it was proposed that at low temperatures and high pressures, solid hydrogen would be a metal with a high superconducting transition temperature. This transition to a metallic state can happen through the closing of the energy gap in the molecular solid or through a transition to an atomic solid. Recent experiments have managed to reach pressures in the range of 400-500 GPa, providing valuable insights. There is strong evidence suggesting that metallization via either of these mechanisms occurs within this pressure range. Computational and experimental studies have identified multiple promising crystal phases, but the limited accuracy of calculations and the limited capabilities of experiments prevent us from determining unequivocally the observed phase or phases. Therefore, it is crucial to investigate the superconducting properties of all the candidate phases. Recently, we reported the superconducting properties of theC2/c-24,Cmca-12,Cmca-4 andI41/amd-2 phases, including anharmonic effects. Here, we report the effects of anisotropy on superconducting properties using Eliashberg theory. Then, we investigate the superconducting properties of deuterium and estimate the size of the isotope effect for each phase. We find that the isotope effect on superconductivity is diminished by anharmonicity in theC2/c-24 andCmca-12 phases and enlarged in theCmca-4 andI41/amd-2 phases. Our anharmonic calculations of theC2/c-24 phase of deuterium agree closely with the most recent experiment by Loubeyreet al(2022Phys. Rev. Lett.29035501), indicating that theC2/c-24 phase remains the leading candidate in this pressure range, and has a strong anharmonic character. These characteristics can serve to distinguish among crystal phases in experiment. Furthermore, expanding our understanding of superconductivity in pure hydrogen holds significance in the study of high-Tchydrides.

β-Ga2O3 has attracted much recent attention as a promising ultrawide bandgap semiconductor. Hydrogen can affect the conductivity of β-Ga2O3 through the introduction of shallow donors and the passivation of deep acceptors. The introduction of H or D into β-Ga2O3 by annealing in an H2 or D2 ambient at elevated temperature produces different classes of O–H or O–D centers. This work is a study of the interaction of D with V Ga 1 and V Ga 2 deep acceptors as well as other impurities and native defects in Ga2O3 by infrared spectroscopy and the complementary theory. (We focus primarily on the deuterium isotope of hydrogen because the vibrational modes of O–D centers can be detected with a higher signal-to-noise ratio than those of O–H.) O–D centers in β-Ga2O3 evolve upon annealing in an inert ambient and are transformed from one type of O–D center into another. These reactions affect the compensation of unintentional shallow donors by deep acceptors that are passivated by D. Defects involving additional impurities in β-Ga2O3 compete with V Ga deep acceptors for D and modify the deuterium-related reactions that occur. The defect reactions that occur when D is introduced by annealing in a D2 ambient appear to be simpler than those observed for other introduction methods and provide a foundation for understanding the D-related reactions that can occur in more complicated situations. [ABSTRACT FROM AUTHOR]

Isotopically labeled alkanes play a crucial role in organic and pharmaceutical chemistry. While some deuterated methylating agents are readily available, the limited accessibility of other deuteroalkyl reagents has hindered the synthesis of corresponding products. In this study, we introduce a nickel‐catalyzed system that facilitates the synthesis of various deuterium‐labeled alkanes through the hydrodeuteroalkylation of d2‐labeled alkyl TT salts with unactivated alkenes. Diverging from traditional deuterated alkyl reagents, alkyl thianthrenium (TT) salts can effectively and selectively introduce deuterium at α position of alkyl chains using D2O as the deuterium source via a single‐step pH‐dependent hydrogen isotope exchange (HIE). Our method allows for high deuterium incorporation, and offers precise control over the site of deuterium insertion within an alkyl chain. This technique proves to be invaluable for the synthesis of various deuterium‐labeled compounds, especially those of pharmaceutical relevance. [ABSTRACT FROM AUTHOR]

We have demonstrated atomic-scale defect characterization in scanning tunneling microscopy images of single crystal tungsten diselenide using an ensemble of U-Net-like convolutional neural networks. Coordinates, counts, densities, and spatial extents were determined from almost 16 000 defect detections, leading to the rapid identification of defect types and their densities. Our results show that analysis aided by machine learning can be used to rapidly determine the quality of transition metal dichalcogenides and provide much needed quantitative input, which may improve the synthesis process. [ABSTRACT FROM AUTHOR]

To detect hydrogen in materials at the atomic scale, atom probe tomography is now regularly used. In order to avoid cumbersome cryo‐preparation to suppress diffusion, often hydrogen is charged only into the finished specimen. Here, the use of hydrogen gas over electrochemical hydrogen has the advantage that the specimen is not contaminated with an electrolyte. So far, this "charging" has been done in large, expensive systems. Here, we introduce small devices that enable the exposure of atom probe specimens to hydrogen and potentially other gases, using only very small gas volumes. This enables the operation in regular laboratory environments without additional safety measures. These devices can be used to expose the specimen to hydrogen up to 10 bar/90°C. Higher temperatures may be attained with small changes. Validation of the success of charging with these setups is demonstrated through experiments employing deuterium charging of palladium atom probe tips. Research Highlights: Enabling the exposure of atom probe specimens to hydrogen and potentially other gases, using only very small gas volumes.Built setups can be assembled with little money and from freely available parts, making specimen charging much easier.Validation of the success of charging with these setups is demonstrated through experiments employing deuterium charging of palladium atom probe tips. [ABSTRACT FROM AUTHOR]

The synthesis of a water‐soluble, phosphine‐pegylated iridium(I) catalyst and its application in hydrogen isotope exchange (HIE) reactions in buffer is reported. The longer polyethylene glycol side chains on the phosphine increased the water solubility independently from the pH. HIE reactions of polar substrates in protic solvents were studied. DFT calculations gave further insights into the catalytic processes. The scope and limitation of the pegylated catalyst was studied in HIE reactions of several complex compounds in borax buffer at pH 9 and the best conditions were applied in a tritium experiment with the drug telmisartan. [ABSTRACT FROM AUTHOR]

This article analyzes a power-to-hydrogen system, designed to provide high-temperature heat to hard-to-abate industries. We leverage on a geospatial analysis for wind and solar availability and different industrial demand profiles with the aim to identify the ideal sizing of plant components and the resulting Levelized Cost of Hydrogen (LCOH). We assess the carbon intensity of the produced hydrogen, especially when grid electricity is utilized. A methodology is developed to size and optimize the PV and wind energy capacity, the electrolyzer unit, and hybrid storage, by combining compressed hydrogen storage with lithium-ion batteries. The hydrogen demand profile is generated synthetically, thus allowing different industrial consumption profiles to be investigated. The LCOH in a baseline scenario ranges from 3.5 to 8.9 €/kg, with the lowest values in wind-rich climates. Solar PV only plays a role in locations with high PV full-load hours. It was found that optimal hydrogen storage can cover the users' demand for 2–3 days. Most of the considered scenarios comply with the emission intensity thresholds set by the EU. A sensitivity analysis reveals that a lower variability of the demand profile is associated with cost savings. An ideally constant demand profile results in a cost reduction of approximately 11 %. [Display omitted] • Geospatial analysis of renewables across Europe. • Hydrogen to heat for heavy industry. • Optimization of wind and PV resources. • Hydrogen storage dominates battery storage. [ABSTRACT FROM AUTHOR]

As the country that emits the most carbon in the world, China needs significant and urgent changes in carbon emission control in the transportation sector in order to achieve the goals of reaching peak carbon emissions before 2030 and achieving carbon neutrality by 2060. Therefore, the promotion of new energy vehicles has become the key factor to achieve these two objectives. For the reason that the comprehensive transportation cost directly affects the end customer's choice of heavy truck models, this work compares the advantages, disadvantages, and economic feasibility of diesel, liquefied natural gas (LNG), electric, hydrogen, and methanol heavy trucks from a total life cycle cost and end-user perspective under various scenarios. The study results show that when the prices of diesel, LNG, electricity, and methanol fuels are at their highest, and the price of hydrogen is 35 CNY/kg, the total life cycle cost of the five types of heavy trucks from highest to lowest are hydrogen heavy trucks (HHT), methanol heavy trucks (MHT), diesel heavy trucks (DHT), electric heavy trucks (EHT), and LNG heavy trucks (LNGHT), ignoring the adverse effects of cold environments on car batteries. When the prices of diesel, LNG, electricity, and methanol fuels are at average or lowest levels, and the price of hydrogen is 30 CNY/kg or 25 CNY/kg, the life cycle cost of the five heavy trucks from highest to lowest are HHT, DHT, MHT, EHT, and LNGHT. When considering the impact of cold environments, even with lower electricity prices, EHT struggle to be economical when LNG prices are low. If the electricity price is above 1 CNY/kWh, regardless of the impact of cold environments, the economic viability of EHT is lower than that of HHT with a purchase cost of 500,000 CNY and a hydrogen price of 25 CNY/kg. Simultaneously, an exhaustive competitiveness analysis of heavy trucks powered by diverse energy sources highlights the specific categories of heavy trucks that ought to be prioritized for development during various periods and the challenges they confront. Finally, based on the analysis results and future development trends, the corresponding policy recommendations are proposed to facilitate high decarbonization in the transportation sector. [ABSTRACT FROM AUTHOR]

This study investigated the ammonia decomposition mechanism over Ru/CeO2. Isotopic tests using ND3 revealed that the rate-determining step involves adsorbed nitrogen atoms on Ru. Moreover, an inverse kinetic isotope effect where ND3 decomposition was faster than NH3 was clearly observed. The origin of the inverse effect was explained by the lower D coverage on the catalyst surface compared to H coverage for mitigating the inhibition of ND3 activation. [ABSTRACT FROM AUTHOR]

Since its discovery by Harold Urey in 1932, deuterium has attracted increased amounts of attention from the scientific community, with many previous works aimed to uncover its biological effects on living organisms. Existing studies indicate that deuterium, as a relatively rare isotope, is indispensable for maintaining normal cellular function, while its enrichment and depletion can affect living systems at multiple levels, including but not limited to molecules, organelles, cells, organs, and organisms. As an important compound of deuterium, deuterium-depleted water (DDW) possess various special effects, including but not limited to altering cellular metabolism and potentially inhibiting the growth of cancer cells, demonstrating anxiolytic-like behavior, enhancing long-term memory in rats, reducing free radical oxidation, regulating lipid metabolism, harmonizing indices related to diabetes and metabolic syndrome, and alleviating toxic effects caused by cadmium, manganese, and other harmful substances, implying its tremendous potential in anticancer, neuroprotective, antiaging, antioxidant, obesity alleviation, diabetes and metabolic syndrome treatment, anti-inflammatory, and detoxification, thereby drawing extensive attention from researchers. This review comprehensively summarizes the latest progress in deuterium acting on living organisms. We start by providing a snapshot of the distribution of deuterium in nature and the tolerance of various organisms to it. Then, we discussed the impact of deuterium excess and deprivation, in the form of deuterium-enriched water (DEW) and deuteriumdepleted water (DDW), on living organisms at different levels. Finally, we focused on the potential of DDWas an adjuvant therapeutic agent for various diseases and disorders. [ABSTRACT FROM AUTHOR]

The isotopic signature (δ18О, δ2Н, d-excess) of the glacier ice in Ushkovskii volcano (Kamchatka Peninsula) was studied. A new shallow ice core was obtained in 2022 in the Gorshkov crater. The 14 m long ice core was dated by counting the annual layers, which were also compared with known eruptions in recent years. The upper 14 m of the glacier were formed over the last 16 years (from 2006 to 2022). The values of δ18О vary from −16 to −24‰, and the values of δ2Н, from −110.5 to −177.7‰, while the mean values are −20.5 and −150.2‰, respectively. The d-excess values vary with depth from 8.7 to 21.3‰ at a mean value of 13.7‰. For winter horizons at low values of δ18О and δ2Н, an increase in d-excess is noted. Such features are associated with the origin of moisture brought to Kamchatka. The source of moisture is the Pacific Ocean, the Sea of Okhotsk, and the Sea of Japan, for which there are pronounced differences in the conditions of moisture evaporation between summer and winter. The trends of increases in the δ18О and δ2Н values from 2006 to 2022 are accompanied by a decrease in the deuterium excess, indicating an increase in summer precipitation. However, in addition to changes in the seasonal proportions of precipitation, the d-excess values of ice may reflect climatic changes in the source of moisture. [ABSTRACT FROM AUTHOR]

Fuel retention in plasma-facing components (PFCs) is a critical issue in future nuclear fusion reactors operating with Deuterium-Tritium (DT) regarding nuclear safety and fulfillment of the T cycle. However, during DT plasma operation, highly energetic neutrons will induce damage in the lattice of W PFCs causing enhanced fuel retention in defects or traps. Laser-Induced Breakdown Spectroscopy (LIBS) is a potential tool to monitor the T-content in situ in PFCs of future nuclear fusion devices. This article presents an ex situ study on pre-damaged W material after D plasma exposure to qualify the method and mimic conditions expected in a reactor. ITER grade W samples were displacement-damaged by 10.8 MeV W ions to a damage dose of 0.23 dpa and exposed to low temperature deuterium plasma at low energy in PlaQ. The resulting deuterium concentration was analyzed by using 3He Nuclear Reaction Analysis (depth resolution of ≈ 150 nm) as a well-established method, and LIBS (picosecond laser pulses, depth resolution of 15 nm). The sample with the highest deuterium concentration showed a deuterium-rich zone up to a depth of 1.13 μm using both techniques. This is close to the expected W ion-induced damage depth of ≈ 1 μm. The results imply that LIBS as an in situ technique for tritium monitoring could be a viable option for a reactor. [ABSTRACT FROM AUTHOR]

A 3D analysis of plasma wall interactions and global impurity transport for the edge localized mode suppression window in KSTAR during H-Mode discharges has shown that carbon erosion at the divertor plates is a strong function of the resonant magnetic perturbation (n = 1) coil current and relative phasing. The Generalized Perturbation Equilibrium Code was used to determine a realistic initial perturbed plasma equilibrium, and EMC3-EIRENE was used to calculate the resulting scrape-off layer plasma used in this study as a fixed background for the ERO2.0 plasma–material interaction model. The resulting transport leads to deposition of impurities along the targets positioned at the high-field side of the device. An attempt at calculating the resulting effective charge state has demonstrated a similar dependence on the perturbation coil current and has been able to determine a window for the experimentally observed values of Z eff by including contributions of all ionized carbon charge states and deuterium. [ABSTRACT FROM AUTHOR]

We present details of recent extensions of the runaway electron (RE) fluid model implemented in the fusion magnetohydrodynamics code JOREK [M. Hoelzl et al., Nucl. Fusion 61, 065001 (2021)] to include the effects of partially ionized impurity species and deuterium neutrals. The model treats the interaction of runaway electrons with the background plasma via current-coupling. The code is separately benchmarked using ITER (https://www.iter.org/) relevant scenarios, with the GO [G. Papp et al., Nucl. Fusion 53, 123017 (2013)] code in relation to runaway electron beam formation and with the DINA [Khayrutdinov and Lukash, J. Comp. Phys. 109(2), 193–201 (1993)] code in relation to simultaneous runaway beam formation and vertical plasma motion. Benchmark results show a decent agreement in both the cases, which are also discussed. [ABSTRACT FROM AUTHOR]

The patterns of catalytic ignition of deuterium–air mixtures above the surface of metallic rhodium at pressures of 1–2 atm and temperatures of 20–250°C using hyperspectrometers in the range of 400–1650 nm and high-speed filming have been established. It is established that the catalytic ignition of deuterium–air mixtures in the studied temperature range is observed at a deuterium content of more than 12%; and at a deuterium content of less than 12%, only intense heating of the catalytic wire is observed. It is shown that the initial ignition source occurs on the surface of the reactor. In subsequent experiments, under the same conditions, the location of the original center changes. It has been found that the upper limit of the catalytic ignition above the D2–air mixture is noticeably lower than the lower ignition limit of the H2–air mixture. Thus, D2 is more combustible than H2 over the surface of Rh at a pressure above 1 atm. The limits of catalytic ignition are even lower than 20°C, although the flame velocity in hydrogen–air mixtures and the flame temperature in these mixtures of the same composition are much higher than those of deuterium–air mixtures. The nature of the detected kinetic inverse isotope effect is probably determined by the high level of activity of rhodium deuteride in relation to the deuterium oxidation reaction. [ABSTRACT FROM AUTHOR]

Stable isotope abundances (δ18O and δ2H) in regional aquifers can provide important paleoclimate information. However, identifying paleoclimate signals can be complicated by cross-formational mixing and, potentially, by isotopic diffusion between aquifers and confining units. We examine controls on δ18O and δ2H distributions in the Wilcox aquifer of the northern Gulf Coastal Plain (USA). We sampled groundwater for δ18O, δ2H, Cl−, and 36Cl along a ~300 km downgradient transect. We developed a simplified, 1D numerical model of groundwater flow and 18O transport to assess the possible importance of isotopic diffusion between the aquifer and its confining units. Along the inferred flowpath, δ18O and δ2H values were depleted by as much as 1.3 and 8.2‰, respectively, as the Wilcox aquifer transitioned from unconfined to confined. However, they then gradually rose farther downgradient by up to 1.1 and 8.6‰. Chlorine-36 analyses and 14C analyses (from other studies) indicate that groundwater ages range from ~103 yr to ~8 × 105 yr. Modeling results indicate that the effect of diffusion on isotopic abundances is limited, whereas Cl− data indicate that cross-formational flow is limited. Therefore, we posit that confined groundwater in our study reflects a Pleistocene paleorecharge signal. [ABSTRACT FROM AUTHOR]

The production of light, energetic and low-flux ions as a secondary beam caused by nuclear reaction can be used in various branches of nuclear physics. Due to the limited availability of energy in small laboratories equipped with electrostatic accelerators, accessing energetic light particles is crucial. For this purpose, selected nuclear reactions were introduced. In this research, primary proton, deuterium and helium-3 beams with energy less than 2 MeV were used for samples with a thickness of 1019 atom.cm-2 and the yield of reactions was obtained. The laboratory setup was designed in such a way that in addition to the access to the nuclear reaction products with a suitable yield, favorable conditions were provided for the extraction and transfer of the reaction products as well as their interaction with the sample. In these exothermic nuclear reactions, the yield is in the order of 106 particles and secondary proton and alpha particles with energies of 4 to18.5 MeV have been obtained. Also, the selected reactions are in accordance with the radiation protection protocols of similar laboratories. [ABSTRACT FROM AUTHOR]

Deuterium-depleted water (DDW) is used in the treatment of many diseases, including cancer and diabetes. To detect the effect of DDW on gene expression and activation of the insulin-responsive transporter GLUT4 as a mechanism for improving the pathology of diabetes, we investigated the GLUT4 expression and glucose uptake at various concentrations of DDW using the myoblast cell line C2C12 differentiated into myotubes. GLUT4 gene expression significantly increased under deuterium depletion, reaching a maximum value at a deuterium concentration of approximately 50 ppm, which was approximately nine times that of natural water with a deuterium concentration of 150 ppm. GLUT4 protein also showed an increase at similar DDW concentrations. The membrane translocation of GLUT4 by insulin stimulation reached a maximum value at a deuterium concentration of approximately 50–75 ppm, which was approximately 2.2 times that in natural water. Accordingly, glucose uptake also increased by up to 2.2 times at a deuterium concentration of approximately 50 ppm. Drug-induced insulin resistance was attenuated, and the glucose uptake was four times higher in the presence of 10 ng/mL TNF-α and three times higher in the presence of 1 μg/mL resistin at a deuterium concentration of approximately 50 ppm relative to natural water. These results suggest that DDW promotes GLUT4 expression and insulin-stimulated activation in muscle cells and reduces insulin resistance, making it an effective treatment for diabetes. [ABSTRACT FROM AUTHOR]

This study aimed to synthesise and interpret stable isotopic data (δ2H and δ18O) from various sources to understand the isotope hydrology around coal mine operations in Elk Valley, B.C., Canada. The data, including precipitation, groundwaters, seeps, and mine rock drains, were used to construct a local meteoric water line (LMWL) for the Elk Valley, evaluate the spatiotemporal isotopic composition of its groundwater, and assess mine seepage and mine rock drain discharge. The study revealed a robust LMWL relation (δ2H = 7.4 ± 0.2 · δ18O – 4.3 ± 4.1). The groundwater and seep data indicated a winter season bias and a north–south latitudinal gradient, suggesting rapid near-surface groundwater flow without significant post-precipitation evaporation. Porewater isotope samples from unsaturated mine rock piles (MRPs) showed site-specific evaporation patterns, potentially due to convective air flows or exothermic sulphide oxidation. This research revealed the influence of groundwater and meltwater on rock drain discharge. Based on evaporative mass balance calculations, MRPs seasonally contributed ca. 5 %(December base flow) and 22 % (snowmelt) to drain discharge. The findings underscore the value of stable isotope data collections in the Elk Valley to help better define and quantify the hydrology–hydrogeology, including a better understanding of evaporative conditions in MRPs. [ABSTRACT FROM AUTHOR]

Background: Thermonuclear fusion is a widely discussed approach to energy production. In 2022, Energy Sustain. Soc. published L. Holmlid's paper (Energy Sustain Soc 12:14, 2022, 10.1186/s13705-022-00338-4) containing, in particular, critical statements about the plans for use of the T + D fusion in energy production. An analysis of these and several other statements of L. Holmlid is presented. This analysis complements a similar analysis performed by K. Hansen and J. Engelen (Energy Sustain Soc 13:14, 2023, 10.1186/s13705-023-00403-6). Main text: It is shown that several statements of L. Holmlid about D + T fusion and D + D fusion are mistaken or ungrounded. It is also shown that the statement of L. Holmlid about the products of annihilation of low-energy antiprotons with protons in ultra-dense hydrogen differs strongly from the data on the products of annihilation of stopped antiprotons with protons in liquid hydrogen and with nucleons of the nuclei of elements heavier than hydrogen. Conclusion: The statement "The use of all resources for fusion research on non-sustainable D + T fusion instead of sustainable muon-induced fusion may be a fatal mistake for humanity", made by L. Holmlid in his Reply (Energy Sustain Soc 13:25, 2023, 10.1186/s13705-023-00404-5) to the aforementioned paper by K. Hansen and J. Engelen, is mistaken. [ABSTRACT FROM AUTHOR]

In recent years, the complex evolution of the highly pathogenic avian influenza (HPAI) situation reflects a change in the eco-epidemiology of the causative agent which, among other demands, renews the need for better understanding of the connectivity between countries through the main virus reservoirs to improve prevention, early warning and mitigate the associated risks. Our objective was to determine migratory connectivity of Blue-winged Teal and evaluate the risk of AIV introduction to Cuba by this species. The stable hydrogen isotope (d2H) value in flight feathers was analyzed. Individuals were sampled during the migratory season of 2021 (N=126) and winter residence of 2020 (N=152), in western and central Cuba, respectively. Based on banding records from 1955 to 2018, the transition probabilities from 3 breeding areas in North America to 9 wintering areas was estimated with a Burnham's live-recapture dead-recovery modeling framework. A map of likely origin in North America of the individuals sampled for each season was generated, combining the isotopic information and transition probabilities. Evidence of an age-related and phenological pattern in migratory origins was identified. Individuals harvested in the migratory season in western Cuba were most likely from molt or natal areas in the prairies and forest regions from United States and southern Canada. Alternatively, individuals harvested in winter in the center of Cuba had the most likely origin in the U.S. prairie region. The spatial-temporal pattern of AIV prevalence in the estimated region was analyzed and suggestions are made to assist the Cuban system of active AIV surveillance of wild birds. [ABSTRACT FROM AUTHOR]

This research employed stable isotope analysis to investigate the migratory patterns and geographic origins of Eleonora's falcon (Falco eleonorae) and its associated prey species within the Galite Archipelago of Tunisia. Feathers collected from both juvenile and adult falcons along with their prey were analyzed for deuterium isotopic composition using the IsoriX package in R, which facilitated geographic assignment based on stable isotope ratios. The results demonstrated no significant difference in deuterium values (d2H) between adult and juvenile individuals of Eleonora's falcon, indicating a lack of geographic variation in molting locations among different age groups. However, the isotopic data for adult falcons yielded unexpected results, suggesting origins close to the sampling site, which contradicted the anticipated patterns of migration to distant wintering grounds. Furthermore, this study successfully mapped the origins of various prey species, indicating a broad geographic intake ranging from the Mediterranean to southern Scandinavia. These findings highlight the complexity of migratory behaviors in predatory birds and underscore the efficacy of stable isotope analysis as a tool for ecological research in avian migration studies. [ABSTRACT FROM AUTHOR]

The importance of deuterium labelling in a variety of applications, ranging from mechanistic studies to drug‐discovery, has spurred immense interest in the development of new methods for its efficient incorporation in organic, and especially in bioactive molecules. The five‐membered heteroarenes at the center of this work are ubiquitous motifs in bioactive molecules and efficient methods for the deuterium labelling of these compounds are therefore highly desirable. However, the profound differences in chemical properties encountered between different heteroarenes hamper the development of a single set of broadly applicable reaction conditions, often necessitating a separate optimization campaign for a given type of heteroarene. In this study we describe the use of a multi‐substrate screening approach to identify optimal reaction conditions for different classes of heteroarenes from a minimal number of screening reactions. Using this approach, four sets of complementary reaction conditions derived from our dual ligand‐based palladium catalysts for nondirected C(sp2)−H activation were identified, that together enable the deuteration of structurally diverse heteroarenes, including bioactive molecules. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate an efficient method for multi‐deuterium labelling of pirtobrutinib—a Bruton's tyrosine kinase inhibitor recently approved by the FDA—using a straightforward hydrogen isotope exchange (HIE) reaction. A remarkably high level of deuterium incorporation was achieved using an excess of a Kerr‐type iridium catalyst. The key factor in the significant deuterium labelling was the decision to employ a deuterium uniformly labelled solvent, chlorobenzene‐d5, at an elevated temperature. Virtually, no d0–d3 species were detected, with only traces of d4–d5 isotopomers (< 5%) observable in the mass spectrum of pirtobrutinib‐d8, fulfilling requirements for stable isotope‐labelled internal standard. The labelled compound—mainly consisting of isotopomers d6–d9 at 82.4% of the total abundance—was isolated in a high yield (73%) and purity (99%). Noteworthy, fluorine group acting as a directing group was observed for the first time. Significant incorporation of deuterium in ortho‐positions, exceeding 87%, was observed. Interestingly, chlorinated solvent used in the HIE reactions was non‐specifically deuterated yielding up to 0.42 deuterium per chlorobenzene molecule even at an exceptionally low iridium catalyst loading of 4.17 × 10–2 mol%. [ABSTRACT FROM AUTHOR]

Die Bedeutung deuterierter Verbindungen für eine Vielzahl von Anwendungen, die von mechanistischen Studien bis hin zur Entdeckung von Arzneimitteln reichen, hat erhebliches Interesse an der Entwicklung neuer Methoden für den effizienten Einbau von Deuterium in organische und insbesondere in bioaktive Moleküle geweckt. Fünfgliedrige Heteroaromaten, die im Zentrum dieser Arbeit stehen, sind omnipräsente Motive in bioaktiven Molekülen und die Entwicklung effizienter Methoden zur Deuterierung dieser Verbindungen ist daher ein äußerst wichtiges Ziel der organischen Synthesechemie. Die signifikanten Unterschiede in den chemischen Eigenschaften verschiedener Heteroaromaten erschweren jedoch die Entwicklung allgemein anwendbarer Reaktionsbedingungen, so dass häufig eine separate Optimierungskampagne für jede unterschiedliche Heteroaromatenklasse erforderlich ist. In dieser Studie beschreiben wir die Verwendung eines Multi‐Substrat‐Screening‐Ansatzes, um optimale Reaktionsbedingungen für verschiedene Klassen von Heteroaromaten mit einer minimalen Anzahl von Screening‐Reaktionen zu ermitteln. Mithilfe dieses Ansatzes wurden, aufbauend auf unseren zwei Liganden‐basierten Palladiumkatalysatoren für die nicht‐dirigierte C(sp2)−H Aktivierung von Aromaten, vier komplementärere Reaktionsbedingungen identifiziert, die zusammen die Deuterierung strukturell vielseitiger Heteroaromaten, einschließlich bioaktiver Moleküle, ermöglichen. [ABSTRACT FROM AUTHOR]

The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world's most powerful pulsed neutron source. Supported by a 3 million Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) has been completed to develop a second neutron source located below the spallation target. Compared to the first source, designed for high cold and thermal brightness, the new source has been optimized to deliver higher intensity, and a shift to longer wavelengths in the spectral regions of cold (CN, 2–20 Å), very cold (VCN, 10–120 Å), and ultracold (UCN, >500 Å) neutrons. The second source comprises a large liquid deuterium moderator designed to produce CN and support secondary VCN and UCN sources. Various options have been explored in the proposed designs, aiming for world-leading performance in neutronics. These designs will enable the development of several new instrument concepts and facilitate the implementation of a high-sensitivity neutron-antineutron oscillation experiment (NNBAR). This document serves as the Conceptual Design Report for the HighNESS project, representing its final deliverable. [ABSTRACT FROM AUTHOR]

An efficient RuPHOX−Ru catalyzed asymmetric cascade hydrogenation of 3‐substituted chromones has been achieved under mild reaction conditions, affording the corresponding chiral 3‐substituted chromanols in high yields with excellent enantio‐ and diastereoselectivities (up to 99 % yield, >99 % ee and >20 : 1 dr). Control reactions and deuterium labelling experiments revealed that a dynamic kinetic resolution process occurs during the subsequent hydrogenation of the C=O double bond, which is responsible for the high performance of the asymmetric cascade hydrogenation. The resulting products allow for several transformations and it was shown that the protocol provides a practical and alternative strategy for the synthesis of chiral 3‐substituted chromanols and their derivatives. [ABSTRACT FROM AUTHOR]

This paper discussed the use of stable isotope compositions of precipitation (δ2H and δ18O) to understand its characteristics and the parameters controlling meteorological conditions in Malaysia. The meteoric water line for Malaysia, or MMWL established in this study are δ2H = (7.43 ± 0.05)δ18O + (7.33 ± 0.11) (n = 595, r2 = 0.97) for individual values, and δ2H = (7.07 ± 0.20)δ18O + (4.90 ± 0.75) (n = 51, r2 = 0.96) for annual precipitation weighted means. No major variations in local meteoric water lines established between the stations, except for one (i.e., Cameron Highlands), which was found to be significantly different due to its high deuterium excess, or d value, attributed to moisture recycling (re–evapotranspiration) from the surrounding dense rainforest area. The precipitation moisture came from the two monsoon systems; the Northeast monsoon (NEM) and Southwest monsoon (SWM). They differ only slightly in their isotope signatures, where the NEM (winter monsoon) is 0.38‰ more negative than the SWM (summer monsoon), and the rainfall amount and temperature have a relatively weak influence on the stable isotopes in precipitation. Rainfall δ18O is poorly correlated with the monthly rainfall amount and temperature, with very low r2 values (–0.4‰/100 mm; 0.09 and 0.7‰/°C; 0.06, respectively). The seasonal variability of isotopic compositions of precipitation in this region is controlled by the insubstantial but conspicuous inverse correlation amount effect. The seasonal patterns of δ2H and δ18O are evident, with higher values observed during the NEM and lower values observed during SWM. However, the temporal variations of rainfall δ2H and δ18O during NEM and SWM are almost indistinguishable due to local climatic conditions, prevailing atmospheric circulations, and sources of precipitation. The apparent sign of El Niño and La Niña events (2015 and 2017, respectively) of the El Niño–Southern Oscillation (ENSO) cycle were successfully identified from this study, indicated by the heavier δ18O from the peaks in the annual precipitation amount versus δ18O annual precipitation weighted mean plot, while La Niña corresponds to the lighter values of the rainfall isotopes. [ABSTRACT FROM AUTHOR]

Amyloid fibrils, insoluble β‐sheets structures that arise from protein misfolding, are associated with several neurodegenerative disorders. Many small molecules have been investigated to prevent amyloid fibrils from forming; however, there are currently no therapeutics to combat these diseases. Mass spectrometry (MS) is proving to be effective for studying the high order structure (HOS) of aggregating proteins and for determining structural changes accompanying protein–inhibitor interactions. When combined with native MS (nMS), gas‐phase ion mobility, protein footprinting, and chemical cross‐linking, MS can afford regional and sometimes amino acid spatial resolution of the aggregating protein. The spatial resolution is greater than typical low‐resolution spectroscopic, calorimetric, and the traditional ThT fluorescence methods used in amyloid research today. High‐resolution approaches can struggle when investigating protein aggregation, as the proteins exist as complex oligomeric mixtures of many sizes and several conformations or polymorphs. Thus, MS is positioned to complement both high‐ and low‐resolution approaches to studying amyloid fibril formation and protein–inhibitor interactions. This review covers basics in MS paired with ion mobility, continuous hydrogen‐deuterium exchange (continuous HDX), pulsed hydrogen‐deuterium exchange (pulsed HDX), fast photochemical oxidation of proteins (FPOP) and other irreversible labeling methods, and chemical cross‐linking. We then review the applications of these approaches to studying amyloid‐prone proteins with a focus on amyloid beta and alpha‐synuclein. Another focus is the determination of protein–inhibitor interactions. The expectation is that MS will bring new insights to amyloid formation and thereby play an important role to prevent their formation. [ABSTRACT FROM AUTHOR]

Satellite observations of column‐averaged water isotopes are relatively new retrieval products that are in need of further in situ evaluation. Such evaluation studies are generally difficult to perform due to the wide mismatch in temporal and spatial scales between the satellite observations based on instantaneous pixel averages during an overpass and airborne in situ measurements ranging up to several hours over a km‐scale. In addition, topography, weather conditions and in particular cloudiness impose severe constraints on an exact collocation between satellite and airborne in situ measurement platforms. Here we present a new method that allows a comparison between in situ measurements and satellite observations of δD on a broader statistical basis. We use regional isotope‐enabled model simulations as intermediate information to identify the area for best comparisons. Applying our methodology to TROPOMI total column δD retrievals for the L‐WAIVE campaign in Annecy, France, during June 2019 increases the number of satellite pixels for comparison despite widespread cloudiness on average by a factor of 20. In addition, the comparison of simulated and observed δD revealed a dependency of the satellite evaluation on the structure of the middle and upper troposphere. We conclude that our method provides a more robust statistic basis for in situ evaluation of δD satellite retrievals. The method will thus be useful in planning and executing forthcoming validation and evaluation campaigns, and can potentially be used for the evaluation of other satellite products. Plain Language Summary: A characteristic of atmospheric water vapor is the concentration of stable heavy hydrogen and oxygen isotopes. Isotopic concentrations are observed by diverse techniques such as remote sensing from satellites and land‐based instruments, and direct measurements from aircrafts, ships and stations on land. These measurements lead to a variety of data sets which span different distances (from a few to hundreds of km) and time periods (from seconds to days). While remote measurements provide data of a large spatial and temporal coverage at a coarse resolution, direct measurements are often obtained during research campaigns over a limited time period with high spatial and temporal resolution. Especially the later data sets are of high value as they describe the atmospheric state in high detail. In this study we develop a method to extrapolate direct, campaign based high‐quality measurements of water vapor to the largest possible representative area using output from a numerical weather simulation. This allows us to compare remotely sensed and direct isotope measurements. This comparison illustrates how to interpret total column measurement and to identify where the model has difficulties to correctly simulate the vertical isotope distribution. This knowledge is of use for future application of remotely sensed data sets and model development. Key Points: New, expanded collocation criterion provides larger data sets for comparison of δD observations during a field campaignWe evaluate TROPOMI δD column retrievals with in situ airborne measurements using a COSMOiso‐based collocation criterionThe combination of subcolumn and total column averaged δD is used to characterize vertical δD gradients and reveal model biases [ABSTRACT FROM AUTHOR]

In this study, the PEDOT:PSS conductive polymer material was spin‐coated on the ITO surface to improve the surface roughness of the ITO and reduce the spikes on the ITO surface, so as to avoid the burning spots generated in the green organic light emitting diode (OLED) when the voltage was applied to light it up. The OLED emitting is successfully survived. Deuterium atoms (isotopes of hydrogen) with heavier atomic weights can strengthen C‐D bonds, slow down the kinetic rate for unwarranted chemical reactions, and improve the performance and stability of OLEDs. In this study, deuterated D‐Ir (mppy)3 was employed as the dopant in the emitting layer of green OLED to replace the general Ir (mppy)3 to improve the optoelectronic properties and extend the lifetime of green OLED. At a constant voltage of 4 V, the initial luminance and half lifetime of general Ir (mppy)3 doped and deuterated D‐Ir (mppy)3 doped OLEDs are 188.1 cd/m2, 7.2 h and 438.3 cd/m2, 42.8 h, respectively. It is shown that doping the deuterated D‐Ir (mppy)3 material in the emitting layer has the effect of prolonging the lifetime of OLED. Compared with the general Ir (mppy)3, the lifetime of deuterated D‐Ir (mppy)3 doped OLED achieved an extension by 5.9 times. [ABSTRACT FROM AUTHOR]

In the 1H NMR spectra (DMSO-d6) of 1,3-disubstituted ureas containing the 4,7,7-trimethyl-3-oxo-4-oxabicyclo[2.2.1]heptan-1-yl substituent, the signals for the CH2—CH2 moiety appear as an ADMP-type spin system consisting of four doublets of doublets of doublets with chemical shifts in the range from 1.54 to 2.80 ppm. The experiment in CD3OD showed the disappearance of the signal at δ 2.80 and a change in the multiplicity of the other signals, which is indicative of the selective deuterium exchange of one of the four protons of the CH2—CH2 group for a deuterium atom. This allows the selective modification of compounds containing the oxacamphanyl moiety. [ABSTRACT FROM AUTHOR]

A set of quantum chemical descriptors (molecular polarization, heat capacity, entropy, Mulliken net charge of the most positive hydrogen atom, APT charge of the most negative atom and APT charge of the most positive atom with hydrogen summed into heavy atoms) was successfully used to establish the classification models for the toxicity pLC50 of pesticides in Americamysis bahia. The optimal random forest model (Class Model A) yielded predictive accuracy of 100% (training set of 217 pesticides), 95.8% (test set of 72 pesticides) and 99.0% (total set of 289 pesticides), which were very satisfactory, compared with previous classification models reported for the toxicity of compounds in aquatic organisms. Therefore, it is reasonable to apply the quantum chemical descriptors associated with molecular structural information on molecular bulk, chemical reactivity and weak interactions, to develop classification models for the toxicity pLC50 of pesticides in A. bahia. [ABSTRACT FROM AUTHOR]

Hydrogen in β-Ga2O3 passivates shallow impurities and deep-level defects and can have a strong effect on conductivity. More than a dozen O–D vibrational lines have been reported for β-Ga2O3 treated with the heavy isotope of hydrogen, deuterium. To explain the large number of O–D centers that have been observed, the involvement of additional nearby defects and impurities has been proposed. A few O–H centers have been associated with specific impurities that were introduced intentionally during crystal growth. However, definitive assignments of O–H and O–D vibrational lines associated with important adventitious impurities, such as Si and Fe, have been difficult. A set of well-characterized Si-doped β-Ga2O3 epitaxial layers with different layer thicknesses has been deuterated and investigated by vibrational spectroscopy to provide new evidence for the assignment of a line at 2577 cm−1 to an OD–Si complex. The vibrational properties of several of the reported OD-impurity complexes are consistent with the existence of a family of defects with a V Ga 1 ic − D center at their core that is perturbed by a nearby impurity. [ABSTRACT FROM AUTHOR]

Stable isotopes in natural water bodies serve as hydrologic tracers, with a history of extensive application in karst groundwater research. The present paper is a systematic review of previous research results, with the objective of sorting out and summarizing the stable isotopic characteristics of karst groundwater in southwest China, which is the most typical karst region worldwide. Comprehensive analysis reveals that the deuterium and oxygen isotope values of most karst groundwater are characterized temporally as 'enriched in the rainy season and depleted in the dry season', which is the opposite of the pattern of precipitation. While the spatial distribution feature is basically consistent with the spatial variation pattern of precipitation, which is characterized as 'depleted from the coast to the interior'. Additionally, the main applications of stable isotopes to karst groundwater are discussed, including karst groundwater recharge source and recharge elevation identification, research on karst groundwater in the hydrological cycle, the hydrological process of karst groundwater, and karst groundwater contamination tracking. Finally, we looked forward to future research on karst groundwater based on deuterium and oxygen isotopes. It is our hope that this review may provide insight into the study of karst groundwater. [ABSTRACT FROM AUTHOR]

Despite their chemical simplicity, the spectroscopic investigation of light hydrides, such as hydrogen sulfide, is challenging due to strong hyperfine interactions and/or anomalous centrifugal-distortion effects. Several hydrides have already been detected in the interstellar medium, and the list includes H2S and some of its isotopologues. Astronomical observation of isotopic species and, in particular, those bearing deuterium is important to gain insights into the evolutionary stage of astronomical objects and to shed light on interstellar chemistry. These observations require a very accurate knowledge of the rotational spectrum, which is so far limited for mono-deuterated hydrogen sulfide, HDS. To fill this gap, high-level quantum-chemical calculations and sub-Doppler measurements have been combined for the investigation of the hyperfine structure of the rotational spectrum in the millimeter- and submillimeter-wave region. In addition to the determination of accurate hyperfine parameters, these new measurements together with the available literature data allowed us to extend the centrifugal analysis using a Watson-type Hamiltonian and a Hamiltonian-independent approach based on the Measured Active Ro-Vibrational Energy Levels (MARVEL) procedure. The present study thus permits to model the rotational spectrum of HDS from the microwave to far-infrared region with great accuracy, thereby accounting for the effect of the electric and magnetic interactions due to the deuterium and hydrogen nuclei. [ABSTRACT FROM AUTHOR]

We present a classical density functional theory (DFT) for fluid mixtures that is based on a third-order thermodynamic perturbation theory of Feynman-Hibbs-corrected Mie potentials. The DFT is developed to study the interfacial properties of hydrogen, helium, neon, deuterium, and their mixtures, i.e., fluids that are strongly influenced by quantum effects at low temperatures. White Bear fundamental measure theory is used for the hard-sphere contribution of the Helmholtz energy functional, and a weighted density approximation is used for the dispersion contribution. For mixtures, a contribution is included to account for non-additivity in the Lorentz–Berthelot combination rule. Predictions of the radial distribution function from DFT are in excellent agreement with results from molecular simulations, both for pure components and mixtures. Above the normal boiling point and 5% below the critical temperature, the DFT yields surface tensions of neon, hydrogen, and deuterium with average deviations from experiments of 7.5%, 4.4%, and 1.8%, respectively. The surface tensions of hydrogen/deuterium, para-hydrogen/helium, deuterium/helium, and hydrogen/neon mixtures are reproduced with a mean absolute error of 5.4%, 8.1%, 1.3%, and 7.5%, respectively. The surface tensions are predicted with an excellent accuracy at temperatures above 20 K. The poor accuracy below 20 K is due to the inability of Feynman–Hibbs-corrected Mie potentials to represent the real fluid behavior at these conditions, motivating the development of new intermolecular potentials. This DFT can be leveraged in the future to study confined fluids and assess the performance of porous materials for hydrogen storage and transport. [ABSTRACT FROM AUTHOR]

The charge-transfer (CT) excited state of FHCl (F+H–Cl−), generated by the photodetachment of an electron from its precursor anion (FHCl−) by a photon energy of ∼9.5 eV, is a realistic prototype of two bidirectional-coupled reaction pathways, namely the proton-transfer (PT) and electron-transfer (ET) channels, that produce F + HCl and FH + Cl combinations, respectively. The early-time dynamics of the CT was studied via the time-dependent propagations of nuclear wave packets comprising three nonadiabatically coupled electronic states defined within a three-dimensional space. The detailed analyses of the early-time dynamics revealed an interesting phenomenon in which the onset of PT was ∼80 fs earlier than that of ET, indicating that PT dominated ET in this case. A more significant finding was that the proper adjustment of the electronic-charge distribution for the onset of ET was obtained ∼80 fs after the onset of PT; this adjustment was mediated by the initial movement of the H atom, i.e., the F–H vibration mode. To avail experimental observables, the branching ratio, χ = PT/(PT + ET), and absorption spectrum generating the neutral FHCl molecule from its precursor anion were also simulated. The results further demonstrated the dependences of the χs and spectrum on the change in the initial vibration level of the precursor anion, as well as the isotopic substitution of the connecting H atom with deuterium, tritium, and muonium. [ABSTRACT FROM AUTHOR]

Abstract Background Deuterium metabolic imaging (DMI) has emerged as a promising non-invasive technique for studying metabolism in vivo. This review aims to summarize the current developments and discuss the futures in DMI technique in vivo. Methods A systematic literature review was conducted based on the PRISMA 2020 statement by two authors. Specific technical details and potential applications of DMI in vivo were summarized, including strategies of deuterated metabolites detection, deuterium-labeled tracers and corresponding metabolic pathways in vivo, potential clinical applications, routes of tracer administration, quantitative evaluations of metabolisms, and spatial resolution. Results Of the 2,248 articles initially retrieved, 34 were finally included, highlighting 2 strategies for detecting deuterated metabolites: direct and indirect DMI. Various deuterated tracers (e.g., [6,6′-2H2]glucose, [2,2,2′-2H3]acetate) were utilized in DMI to detect and quantify different metabolic pathways such as glycolysis, tricarboxylic acid cycle, and fatty acid oxidation. The quantifications (e.g., lactate level, lactate/glutamine and glutamate ratio) hold promise for diagnosing malignancies and assessing early anti-tumor treatment responses. Tracers can be administered orally, intravenously, or intraperitoneally, either through bolus administration or continuous infusion. For metabolic quantification, both serial time point methods (including kinetic analysis and calculation of area under the curves) and single time point quantifications are viable. However, insufficient spatial resolution remains a major challenge in DMI (e.g., 3.3-mL spatial resolution with 10-min acquisition at 3 T). Conclusions Enhancing spatial resolution can facilitate the clinical translation of DMI. Furthermore, optimizing tracer synthesis, administration protocols, and quantification methodologies will further enhance their clinical applicability. Relevance statement Deuterium metabolic imaging, a promising non-invasive technique, is systematically discussed in this review for its current progression, limitations, and future directions in studying in vivo energetic metabolism, displaying a relevant clinical potential. Key points • Deuterium metabolic imaging (DMI) shows promise for studying in vivo energetic metabolism. • This review explores DMI’s current state, limits, and future research directions comprehensively. • The clinical translation of DMI is mainly impeded by limitations in spatial resolution. Graphical Abstract

Hydrogen isotopes, such as protium(H), deuterium(D), and tritium(T), are widely used in medical treatment, nuclear energy, national defense, and other fields. Under the background of the "double carbon" target with carbon peak and carbon neutralization, deuterium-tritium fusion energy is considered to be an important energy strategy in China. However, the relative abundance of deuterium and tritium in nature is extremely low, and it is of great significance to separate hydrogen isotopes economically and effectively. This paper presents the research on water hydrogen isotope separation technology. Firstly, the methods and the principles of hydrogen isotope separation in water are summarized. Then, two perspectives of separation methods were reviewed. From the perspective of engineering application, the electrolysis, distillation and chemical exchange method are focused. From the perspective of laboratory research and development, the membrane separation method and porous material adsorption method are focused. Finally, the separation factors and energy consumption of typical separation technologies are compared. Moreover, to provide a certain reference for the water hydrogen isotope separation technology, several future research directions are prospected.

The synthesis of deuterated gem-difluoroalkenes via selective deuterodefluorination of β-CF3-cinnamates using a nickel catalyst has been reported for the first time. Commercially available deuterated formic acid is a cheap and convenient deuterium source. The nickel-catalyst showed high selectivity for monodefluorination and avoided competitive reactions such as multiple defluorination or hydrogenation. [ABSTRACT FROM AUTHOR]

Lanthanide luminescence is dominated by quenching by high-energy oscillators in the chemical environment. The rate of non-radiative energy transfer to a single H2O molecule coordinated to a Eu3+ ion exceeds the usual rates of emission by an order of magnitude. We know these rates, but the details of these energy transfer processes are yet to be established. In this work, we study the quenching rates of [Eu(D2O)9]3+ and [Eu(DOTA)(D2O)]− in H2O/D2O mixtures by sequentially exchanging the deuterons with protons. Flash freezing the solutions allows us to identify species with various D/H contents in solution and thus to quantify the energy transfer processes to individual OH-oscillators. This is not possible in solution due to fast exchange in the ensembles present at room temperature. We conclude that the energy transfer processes are accurately described, predicted, and simulated using a step-wise addition of the rates of quenching by each O–H oscillator. This documents the sequential increase in the rate of the energy transfer processes in the quenching of lanthanide luminescence, and further provides a methodology to identify isotopic impurities in deuterated lanthanide systems in solution. [ABSTRACT FROM AUTHOR]