Isotope detection and identification is paramount in many fields of science and industry, such as in the fusion and fission energy sector, in medicine and material science, and in archeology. The isotopic information provides fundamental insight on the research questions related to these fields as well as insight on product quality and operational safety. However, isotope identification with the established mass-spectrometric methods is laborious and requires laboratory conditions. In this work, Microwave-Assisted Laser-Induced Breakdown Spectroscopy (MW-LIBS) is introduced for isotope detection and identification utilizing radical and molecular emission. The approach is demonstrated with stable B and Cl isotopes in solids and H isotopes in liquid using emission from BO and BO2, CaCl, and OH molecules, respectively. MW-LIBS utilizes the extended emissive plasma lifetime and molecular emission signal integration times up to 900 s to enable use of low ~4 mJ ablation energy without compromising signal intensity and, consequently, sensitivity. On the other hand, long plasma lifetime gives time for molecular formation. Increase in the signal intensity towards the late microwave-assisted plasma was prominent in BO2 and OH emission intensities. As MW-LIBS is online-capable and requires minimal sample preparation, it is an interesting option for isotope detection in various applications.

Abiogenic hydrocarbons are fundamentally important for understanding the deep microbial communities and the origin of life. The generation of abiogenic hydrocarbons was proposed to be limited to ultramafic-hosted hydrothermal systems, fueled by the serpentinization product H₂. Here, we present the discharge of short-chain alkanes from an andesitic rock-hosted Lutao geothermal field in the north Luzon arc, carrying abiotic chemical and isotopic signals. These abiogenic hydrocarbons were generated from CO₂-H₂O-rich fluid inclusions, where the long-term storage since Lutao volcanism (~ 1.3 Ma) allowed overcoming the sluggish kinetics of CO₂ to CH₄ reduction at temperatures of 174 - 206 ^oC. Natural abiogenic production of hydrocarbons, therefore, can be more ubiquitous than previously thought. The hypothesis regarding the origin of methane in Earth’s early atmosphere and its implication to the origin of life may require reconsideration.

This interdisciplinary investigation of the human remains of Balduin Helm, one of the most important abbots of Fürstenfeld monastery, provides novel information on that historic individual. This is particularly interesting since Balduin, during early 18th century, was involved in the renovation of this large Bavarian monastery. Metastatic prostate cancer was found as evidenced by multiple mixed osteolytic-osteoblastic bone lesions in all available vertebral bodies, fragments of both hemipelvises and isolated metastases in skull bones. Distribution, radio- and histomorphology, and especially the immunohistochemical detection of prostate-specific antigen in those metastases, definitively confirm this diagnosis. Further investigation, especially by stable isotope analysis, showed a balanced high-level diet with considerable contribution from animal protein and significant freshwater fish. These additional findings suggest a significant radiocarbon reservoir effect as an explanation for a “too old” radiocarbon dating. Finally, the obviously high-level protein diet may have contributed to the tumorigenesis which caused the death of the abbot at an advanced age.

The Woka-Cuona rift zone, situated in the easternmost portion of southern Tibet, displays complex geological conditions. It consists of three distinct grabens or half grabens, spanning the Himalayan and Gangdese terranes from south to north. Examining the distribution patterns and genetic mechanism of the geothermal system in the Woka-Cuona rift zone holds significant guidance for studying the genetic mechanisms of geothermal systems and the production and utilization of ge-othermal resources in the rift zones of southern Tibet. Based on the geological conditions of the study area, the mechanism of rift formation and the distribution characteristics of geothermal water in the three distinct grabens were analyzed through data collection, ground surveys, geochemical analysis, and isotope analysis. Alongside topographic, drainage, and structural features, the Woka-Cuona rift zone was subdivided into four zones from north to south - Woka, Qiongduojiang, northern Cuona, and southern Cuona grabens. Additionally, the study investigated the geochemical char-acteristics, recharge sources, and water-rock interactions of geothermal water in different zones, providing a scientific foundation for subsequent geothermal energy production.

Water resources management is one of the most important challenges worldwide because water represents a vital resource for sustaining life and environment. In the aim of sustainable groundwater management, the identification of aquifer recharge areas is a useful tool for water resources protection. In a well-developed karst aquifer, environmental isotopes provide support for identifying aquifer recharge areas, residence time and interconnections between aquifer systems. This study deals the use of environmental isotopes to identify the main recharge area of a karst aquifer in the Upper Valley of Aniene River (Central Italy). The analysis of 18O/16O and 2H/H values and their spatial distribution in the aquifer, make it possible to trace back groundwater recharge areas based on average isotope elevations. The Inverse Hydrogeological Balance Method was used to validate spring recharge elevations obtained by the use of stable isotopes. Areas impacted by direct and rapid rainfall recharge into the study area were delineated, showing groundwater flowpaths from the boundaries to the core of the aquifer. The results of this study demonstrate the contribution that spatial and temporal isotope changes can provide to the identification of groundwater flowpaths in a karst basin, taking into account the hydrogeological setting

Variations in geochemical signatures of fossil brachiopod shells may be due to diagenesis and/or biological processes (i.e. ‘vital effects’). Characterize them is crucial to identify reliable areas into the shell suitable to paleoclimatological studies. This investigation contributes to an in-depth understanding of geochemical variations of Gigantoproductus sp. shells (SW Spain, Serpukhovian age), which could affect to the Late Paleozoic Ice Age interpretation. Microstructural, crystallographic, cathodoluminescence and geochemical (minor and trace elements, δ18O, δ13C, and strontium isotopes) characterisation have been performed on the tertiary layer of the ventral valve, to assess the preservation state. Poorly-preserved areas exhibit microstructural and geochemical changes such as recrystallisation, fracturing and higher Mn and Fe enrichment. Moreover, these areas have higher dispersion of ⁸⁶Sr, ⁸⁷Sr, δ18O and δ13C than well-preserved areas. Three structural regions have been identified in well-preserved areas of ventral valve by differences in valve curvature and thickness, such as the umbonal, thick and thin regions. These regions have different proportions of Mg, S, Na, δ18O, and δ13C, whom are interpreted as ‘vital effects’ and probably are related with growth rate differences during shell growth. Gigantoproductus tertiary layer seems the best suitable to paleoclimatological studies because it retains the original microstructure and geochemistry.

Cesiumtrifluoroacetate (CsTFA) is a key chemical for RNA-based stable isotope analyses to link the structure and function of microbial communities. We report a protocol to easily synthesize CsTFA from Cesiumcarbonate (Cs₂CO₃₎ and Trifluoroacetate (TFA) and show that self-synthesized CsTFA behaves similar to commercial CsTFA in the separation of isotopically labelled and unlabelled E. coli RNA.

Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29-61 kyrs BP) proves difficult because: i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below present sea level; ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at depth of -130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits laying on metamorphic bedrock of Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 meters above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows to propose a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.

High intrinsic water use efficiency (WUEi), the ratio of leaf photosynthesis to stomatal conductance, may be a useful trait in adapting crops to water-limited environments. Carbon isotope ratios can be a useful indicator of WUEi, but might not be well correlated with it if the plants compared differ substantially in mesophyll conductance. In this study, six cultivars of soybeans previously shown to differ in WUEi in indoor experiments were grown in the field in Beltsville, Maryland, and mid-day WUEi was measured on nine clear days during mid-seasons of two years. Measurement dates were chosen for diverse temperatures, and air temperatures ranged from 21 to 34 oC on the different dates. Corrected carbon isotope delta values for 13C (CID) were determined on mature, upper canopy leaves harvested during early pod filling each year. WUEi differed among cultivars both years and the differences were consistent across measurement dates. Correlations between mean WUEi and CID were not significant in either year. It is concluded that consistent cultivar differences in WUEi exist in these soybean cultivars under field conditions, but that carbon isotope ratios may not be useful in identifying them.

Retrospective information about the climate system and plant ecophysiology are key inputs in climate and Earth system modelling. Dendrochronology provides such information with large spatiotemporal coverage, and stable carbon isotope (¹³C/¹²C) analysis across tree-ring series is among the most advanced dendrochronological tools. For the past seventy years, this analysis was performed on whole molecules, and, to this day, ¹³C/¹²C variation is attributed to ¹³C discrimination during CO₂ diffusion into leaves and assimilation by rubisco. By contrast, ¹³C discrimination by post-rubisco processes is presumed constant. Here, recently reported results on the first dataset of intramolecular ¹³C discrimination in tree rings were synthesised by variance component analysis. The emerging picture is not consistent with the classical (DR-discrimination-centred) concepts and practices of carbon-isotope dendrochronology. Specifically, leaf and stem post-rubisco discrimination each account for more variation in the data than diffusion-rubisco discrimination, i.e., post-rubisco discrimination is not constant. Furthermore, diffusion-rubisco discrimination is used widely as proxy of leaf intrinsic water-use efficiency (iWUE), a key determinant in the responses of global biogeochemical cycles to climate change. However, since diffusion-rubisco discrimination is a small component of the total data variance, whole-molecule analysis yields confounded iWUE estimates, yet intramolecular analysis will likely offer solutions. Lastly, all currently observed ¹³C/¹²C-climate relationships are attributed to diffusion-rubisco discrimination. However, here, relationships with temperature and radiation derive from leaf-level post-rubisco discrimination while relationships with precipitation derive from stem-level post-rubisco discrimination. That said, advances in mass spectrometry may soon make intramolecular ¹³C/¹²C analysis broadly available taking carbon-isotope dendrochronology to the next level.

Oxygen and hydrogen isotopes (18O and 2H) in polar ice offer strong evidence of both long-term and abrupt climate changes. However, reliably estimating surface air temperatures from past climates has proven difficult because the relationship between 18O and temperature cannot be calibrated. In this study, we investigated the 17O and 18O of modern rain and ice cores using published data. We found that precipitation 17O is influenced by two factors: mass-dependent fractionation (MDF) that occurs during ocean evaporation, and mass-independent fractionation (MIF) that happens in the stratosphere. The MDF contribution remains constant and can be understood from studying tropical rain, as the overall movement of mass in the tropics is upward towards the stratosphere. On the other hand, the MIF effect comes from the mixing of stratospheric air in the troposphere, which is a result of the Brewer-Dobson circulation. This MIF effect on precipitation 17O increases from the tropics towards the poles. Therefore, the relative 17O and 18O composition, denoted as '17O, in modern precipitation can be calibrated with surface air temperature, creating a new, independent tool for estimating past temperatures. We used this calibration along with '17O of Antarctic and Greenland ice cores and our results for past temperatures are in excellent agreement with those from borehole thermometry or gas phase analysis of air trapped in the ice. The 17O method overcomes the problems associated with using 18O for paleothermometry. Our findings align with climate models that suggest a weakening of the Brewer-Dobson circulation during the Last Glacial Maximum. Furthermore, our method could be used to monitor future changes in response to a warming climate caused by increasing greenhouse gases.

The purpose of this study was to elucidate patterns and mechanisms driving seasonal and inter-annual variations of carbon and nitrogen stable isotopes in the zooplankton crustacean commu-nity of Lake Maggiore (Italy), during the period 2009-2020. Different zooplankton taxa and groups revealed different ranges of d13C signatures, giving an insight into food sources and niche partition. In particular, cyclopoids had a restricted range with most negative d13C‰ values and increase in d13C fractionation with the establishment of water thermal vertical stratification, high-lighting the importance of vertical distribution as key factor for taxa coexistence in a vertically heterogenous environment. d13C of the zooplankton community and of Daphnia were positively related to water temperature (R2=0.58 p <0.0001 and R2=0.68 p <0.0001, respectively) and d13C Daphnia signature to chlorophyll-a (R2=0.32, p < 0.0001). Decomposition of time series data for zooplankton carbon and nitrogen signatures and environmental parameters identified increasing trends in water temperature, chlorophyll-a and water conductivity and decrease in nitrate, that matched changes in carbon isotopic signature trend in some zooplankton taxa (Bosmina, Daphnia and diaptomids). Overall, the observed patterns in zooplankton isotopic signatures were interpreted as integrations of climate warming effects in Lake Maggiore, affecting both food sources availability and environmental conditions.

Novel cultivation technologies demand the adaptation of existing analytical concepts. Metabolic flux analysis (MFA) requires stable-isotope labeling of biomass-bound protein as the primary information source. Obtaining the required protein in cultivation set-ups where biomass is scarce or inaccessible due to low cell densities and cell immobilization is difficult to date. We developed a non-disruptive analytical concept for 13C-based metabolic flux analysis based on secreted protein as an information carrier for isotope mapping in the protein-bound amino acids. This "metabolic flux probe" (MFP) concept was investigated in different cultivation set-ups with a recombinant, protein-secreting yeast strain. The obtained results grant insight into intracellular protein turnover dynamics. Experiments under metabolic but isotopically nonstationary conditions in continuous glucose-limited chemostats at high dilution rates demonstrated faster incorporation of isotope information from labeled glucose into the recombinant reporter protein than in biomass-bound protein. Our results suggest that the reporter protein was polymerized from intracellular amino acid pools with higher turnover rates than biomass-bound protein. The latter aspect might be vital for 13C-flux analyses under isotopically nonstationary conditions for analyzing fast metabolic dynamics.

The studied Khanbogd pluton of peralkaline granite is located in southern Mongolia and occupies an area of ~1000 sq. km. Previously, two ring-shaped bodies were constructed in a flattened shape pluton. However, this shape was not used for the genesis of this pluton. A recent study of Landsat image showed a several elliptical intrusions in two bodies. Chemistry interpretation shows that each intrusion differs in ASI, CIPW norms, 87Sr/86Sri and δ18O isotopes. Elliptical intrusions, uplifted country rocks between them, and roof pendants suggest magma penetration along fractured country rocks. Furthermore, two adjacent intrusive bodies and undeformed host rocks at the front part of the pluton are consistent with underplating magmatic factors during duplex-type thrusting. This magma event is also supported by low of Sr, Ba, Eu and high of Th, U, Pb anomalies and a few amount of garnet crystals in the granites, implying vapor absent melt crystallization associated with underplating. Multiple melt sources, as well as from mantle and recycled sea floor rocks, are identified by ratio of 87Sr /86Sri and δ18O values. The low isotope values, the thrust nature and 295–286 Ma ages of the alkali granites, indicate an underplate magma evidenced during Permian rifting.

A new approach is presented for dynamic modeling of chemical and isotopic evolution of C1-3 during the hydrocarbon generation process. Based on systematic data obtained from published papers for pyrolysis of various hydrocarbon sources(type I kerogen/source rock, type II kerogen/source rock, type III kerogen/source rock, crude oil, asphalt, etc), the empirical evolution framework of chemical and isotopic composition of C1-3 during the hydrocarbon generation process was built. Although the empirical framework was built only by fitting large amount of pyrolysis data, the chemical and isotopic composition of C1-3 derived from the pyrolysis experiments all follow the evolution laws, convincing us that it is applicable to the thermal evolution process of various hydrocarbon sources. Based on the simplified formula of the isotopic composition of mixed natural gas at different maturities (δ13Cmixed) δ13Cmixed=(X〖*n〗_iA 〖*δ〗^13 C_iA+Y〖*n〗_iB 〖*δ〗^13 C_iB)/(X〖*n〗_iA+Y〖*n〗_iB ), it can be derived that the cumulative isotopic composition of alkane generated in certain maturity interval can be expressed by the integral of the product of instantaneous isotopic composition and instantaneous yield at certain maturity point, and then divided by the cumulative yield of alkane generated in corresponding maturity interval. Thus, the cumulative isotopic composition(A(X)), cumulative yield(B(X)), instantaneous isotope(C(X)),and instantaneous yield(D(x)) in the dynamic model comply with the following formula during the maturity interval of (X0-X) A(X)=(∫_(X_0)^X▒〖C(X)*D(X)dx〗)/(B(X)), where A(X) and B(X) can be obtained by fitting of pyrolysis data, and D(x) can also be obtained from the derivation of B(X). The dynamic model was applied on the pyrolysis data of Pingliang Shale to illustrate the quantitative evolution of cumulative yield ,instantaneous yield, cumulative isotope and instantaneous isotope of C1-3 with increasing maturity.The dynamic model can quantify the yield of methane, ethane and propane as well as δ13C1, δ13C2 and δ13C3 respectively during the hydrocarbon generation process, which is of great significance to evaluate the natural gas resources of hydrocarbon source rock with different maturity and to identify the origin and evolutionary process of hydrocarbons by chemical and isotopic data. Moreover, this model provides an approach to study the dynamic evolution of isotope series of C1-3 (including reversed isotopic series), which is hopeful to reveal the mechanism responsible for isotopic reversal when combined with post-generation studies.

Accurate determination of the concentration of alcohols and their metabolites is important in forensics and in several life science areas. A new method has been developed to quantify alcohols and their oxidative products using a headspace gas chromatography- mass spectrometer and isotope-labelled internal standards. This work demonstrates the application of this method, specifically in quantifying the concentration of oxidative products of alcohol and other minor alcohols found in hand sanitizers, which have become an essential household item since the COVID-19 pandemic. Apart from the major component, the minor alcohols found in hand sanitizers include methanol, isopropanol, and n-propanol. In ethanol-based hand sanitizers, a significant amount of acetaldehyde was observed as an oxidation product, while in isopropanol-based hand sanitizers, acetone was observed. The concentration of acetaldehyde in ethanol-based hand sanitizers significantly increased with storage time and temperature, whereas no such increase of acetone concentration was observed in isopropanol-based hand sanitizers with storage time and temperature.

The study of trophic relationships among closely related species plays an important role in deepening our understanding of the resource utilization characteristics, differentiation patterns, and population dynamics of co-occurring species in the same habitat. This research uses two congeneric fish species, Pennahia pawak and Pennahia anea, as examples. Based on stomach content analysis and carbon-nitrogen stable isotope analysis, a comparative analysis of their feeding habits and trophic niches is conducted. Additionally, spatial niche analysis is employed to explore the coexistence and competitive mechanisms between these two closely related fish species. The results showed that both P. pawak and P. anea had similar feeding habits, mainly feeding on Pisces and Macrura, but there were some feeding preferences between the two species. Interspecific prey overlap was meaningful but not significant, with an overlap coefficient of 0.56. There were significant differences in feeding habits between the two species during different seasons. Based on stable isotope analyses, body length of both species had a significant positive correlation with δ15N (Pearson r=0.65, P&lt;0.01; Pearson r=0.44, P&lt;0.01), but not with δ13C (P&gt;0.05). Standard ellipse corrected area (SEAc) of P. pawak and P. anea were 0.65 and 1.16, while the trophic niche overlap was only 0.29, which was not significant; the spatial niche width of the two was 1.19 and 0.58, respectively, and the spatial niche overlap was only 0.20, which was not significant. Intra-species competition was intense in P. pawak and P. anea, but reduced feeding specialization had a mitigating effect on intra-species competition. Interspecific competition was present but not significant, and was mitigated by trophic and spatial niche differentiation.

The decline in Pinus sylvestris var. mongolica in the introduction area has had a high profile in recent years. For the ecological restoration, management and silvicultural design of Mongolian pines in the introduction area, it is necessary to conduct a comprehensive and in-depth study on the ecological adaptation mechanism of Mongolian pines in provenances. The ecological process of water and nutrient accumulation as well as the influence of environmental factors on the photosynthetic physiology are the key to revealing the ecological adaptation mechanism of Mongolian pines. According to the differences of climate in the distribution area of Mongolian pines, sampling sites were set up, the effects of environmental factors on leaf δ13C and the relationship between leaf δ13C and nutrient content were analyzed. The results showed that leaf δ13C values were ranging from - 29.7 ‰ to - 23.76 ‰. The ecological stoichiometry, including LC (522.81 mg·g-1), LN (16.04 mg·g-1), LP (1.19 mg·g-1) and L-N:P (13.56), indicated that leaf photosynthesis and water use efficiency is greatly affected by environmental conditions, Mongolian pines had strong ability of carbon fixation, and its growth was obviously restricted by nitrogen. Although there was no significant correlation between δ13C with stoichiometric parameters in leaf, photosynthesis was the key link in the process of carbon fixation. It also showed that Pinus sylvestris var. mongolica was a stomatal limited plant. Leaf δ13C had significant correlation with climatic factors. VPD is the dynamic factor affecting the photosynthetic physiological process in leaves. Air and soil moisture are the dominate factors affecting the leaf stomatal conductance and determines leaf δ13C value, while other factors indirectly affect leaf δ13C by its impact on relative humidity or soil water content. Soil phosphorus content affected by clay is a key factor affecting soil water availability and soil nutrient cycling. Photosynthetic process in leaf is the dynamic process affecting the nutrient accumulation.

Stable-isotope dimethyl labeling is a highly reactive and cost-effective derivatization procedure that could be utilized in proteomics analysis. In this study, a liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode (LC-MS-MRM) platform for the quantification of kiwi allergens was first developed using this strategy. Three signature peptides for target allergens Act d 1, Act d 5, and Act d 11 were determined and were derivatized with normal and deuterated formaldehyde as external calibrants and internal standards, respectively. The results showed that sample preparation with the phenol method provided comprehensive protein populations. Recoveries at four different levels ranging from 72.5–109.3% were achieved for the H-labeled signature peptides of Act d 1 (SPA1-H) and Act d 5 (SPA5-H) with precision ranging from 1.86–9.92%. The limit of quantification (LOQ) was set at 8 pg mL–1 for SPA1-H and at 4 ng mL–1 for SPA5-H. The developed procedure was utilized to analyze seven kinds of hand-made kiwi foods containing 0.0175–0.0515 mg g–1 of Act d 1 and 0.0252–0.0556 mg g–1 of Act d 5. This study extended the applicability of stable-isotope dimethyl labeling to the economical and precise determination of food allergens and peptides.

This study innovatively assesses the Mun River flow components in Thailand, integrating Artificial Neural Networks (ANN) and Isotopic (18O) End-Member Mixing Analysis (IEMMA). It quantifies the contributions of the Upper Mun River (UMR) and Chi River (CR) to the overall flow, revealing a discrepancy in their estimated contributions. ANN predicts the UMR and CR contribute approximately 70.1% and 29.5% respectively, while IEMMA indicates a more pronounced disparity with 84% from UMR and 16% from CR. This divergence highlights the distinct perspectives of ANN, focusing on hydrological data patterns, and IEMMA, emphasizing isotopic signatures. Despite discrepancies, both methods validate UMR as a significant contributor to the overall flow, highlighting their utility in hydrological research. The findings underscore the complexity of river systems and advocate for an integrated approach of river flow analysis for a comprehensive understanding, crucial for effective water resource management and planning.

Based on the previous work done by Fujii et al., NdBaInO4 compounds present modest oxide-ion conductivities. Therefore, it has been an attractive system of significant interest. In this paper, the Ca element has been attempted to partially substitute for Nd and the total electrical conductivity has been successfully improved due to the generation of oxygen vacancies. The synthesis, crystal structure, density, surface topography and electrical properties of NdBaInO4 and Ca-doped NdBaInO4 have been studied respectively. NdBaInO4, 10% and 20% molar fraction of Ca doped NdBaInO4 were synthesized through solid state reaction and they were calcined at 1000 °C for 14 hours and sintered at 1440 °C,1430 °C and 1420 °C respectively. The crystal structure of them has been obtained from Le Bail refinement of the XRD pattern, giving the result of the monoclinic structure which belongs to P21/c space group. The size of particles processed with different ball milling time and surface topography have been detected by the scanning electron microscope. The total electrical conductivities of Nd1-xCaxBaInO4-x/2 (x = 0, 0.1 and 0.2) were measured in the dry atmosphere by AC impedance spectroscopy and Nd0.9Ca0.1BaInO3.95 exhibited the highest total electrical conductivity and the lowest activation energy. What is more, the total conductivity of Nd0.9Ca0.1BaInO3.95 in the wet atmosphere at moderate temperature is relatively higher than that in the dry atmosphere while this phenomenon was not found in NdBaInO4. Therefore, the excess conductivity suggests that potential proton conduction may exist in wet atmospheres. In addition, Ca-doped NdBaInO4 were chosen for the oxygen isotope exchange which aims to obtain the diffusion coefficient and surface exchange coefficient, and Nd0.9Ca0.1BaInO3.95 shows the highest diffusion coefficient and D* decreases with the increase of the molar fraction of the Ca element.

A unique two-column ²³⁰U/²²⁶Th generator has been developed. The focus was hold on obtaining ²²⁶Th of high purity in a solution amenable to further labeling. The first column of the proposed generator filled with TEVA Resin held ²³⁰U, from which ²²⁶Th was eluted with 7 M HCl solution. UTEVA Resin pretreated with nitric acid solution was used as a sorbent for the second column for thorium retention. ²²⁶Th was extracted with 0.01-0.05 M citric buffer solution. One cycle of generator milking took 5-7 minutes and produced > 90% of ²²⁶Th in 1.5 ml of eluate, pH 4.5-5.0. The proposed two-column ²³⁰U/²²⁶Th generator was tested over two months including a second loading of ²³⁰U additionally accumulated from ²³⁰Pa. The ²³⁰U impurity in ²²⁶Th eluate was less than 0.01% allowing to use it directly in synthesis of radiopharmaceutical compounds.

Paleoclimate information is key to understanding the climate system and predicting future climate. Currently, stable isotope analysis of whole molecules in tree rings is among the most advanced paleoclimate tools. Still, it only enables reconstructions of one climate parameter at a time (univariate climate reconstruction), a fundamental limitation. Here, we investigated whether this limitation can be overcome by analysing isotope variability at the level of intramolecular carbon positions in tree-ring glucose. We found that drought governs isotope variability at glucose C-1 to C-3, whereas radiation governs isotope variability at glucose C-5 to C-6. These isotope-climate relationships are statistically and mechanistically robust. According to cross-validation analysis, they can be reconstructed with high accuracy and precision. Thus, intramolecular isotope analysis enables multivariate climate reconstructions (proof of concept).

Cordyceps sinensis is one rare medicinal fungus produced in the Qinghai-Tibetan Plateau. Its quality and price varies hugely with different habitat, and its numerous substitutes have sprung up in functional food markets. This paper aims to discriminate the geographic origin of wild C. sinensis and its substitutes via the element analyzer-isotope ratio mass spectrometry and gas chromatography-isotope ratio mass spectrometry. The δ¹³C values of major fatty acids in the lipids of Cordyceps sinensis are characterized unanimously by the variation relation C_18:0 ﹤ C_18:2 ≈ C_16:0 ﹤ C_18:1; while their fluctuation intervals are notably different between those of neutral and polar lipids. The comparative analysis of the δ¹³C ratios of major fatty acids in lipids of Cordyceps sinensis suggests that the δ¹³C patterns may be sensitive potential indicators to discriminate its geographical origin. The δ¹³C values of individual major fatty acids of lipids from the cultivated stromata of Cordyceps militaris (SCM), the fermented mycelia of Hirsurella sinensis (FMH) and Paecilomyces epiali (FMP) range from −31.2‰ to −29.7‰, −16.9‰ to −14.3‰, and −26.5‰ to −23.9‰, respectively. Their δ¹³C pattern of individual major fatty acids may be used as a potential indicator to discriminate the products of natural C. sinensis and its substitutes.

Olive trees have a unique reproductive pattern marked by biennial fruiting. This study delves into the repercussions of alternate fruit bearing on the water relations of olive trees and the associated ecophysiological mechanisms. The experiment spanned two consecutive years: the "ON" year, characterized by a high crop load, and the "OFF" year, marked by minimal fruit production. Key ecophysiological parameters, including sap flow, stomatal conductance, and photosynthetic rate, were monitored in both years. Pre-dawn water potential was measured using continuous stem psychrometers and the pressure chamber technique. Biochemically, non-structural carbohydrate concentrations (starch, sucrose, and mannitol) and the carbon-stable isotope ratio (δ13C) in olive leaves were examined. Results unveiled heightened leaf gas exchange during the "ON" year, leading to increased water consumption and photosynthetic rates. This escalated water usage during the "ON" year significantly reduced leaf water potential. Sucrose and starch concentrations were notably elevated in the "ON" year, with no significant impact on mannitol concentration. Regarding the carbon stable isotope ratio, leaves from the "OFF" year exhibited significantly higher δ13C abundance, indicative of heightened resistance to the CO2 pathway from the atmosphere to carboxylation sites compared to the "ON" year plants.

In recent years, the genesis of natural gas and the definition of major gas source rocks in the Baiyun Sag of the Pearl River Mouth Basin have attracted extensive attention from scholars. There is still considerable controversy over the genesis and the main gas source rocks of natural gas. In this study, the chemical kinetics method of natural gas generation and carbon isotope fractionation was used to study the generation history and isotope evolution history of Paleogene natural gas in the Y5 well area located on the north slope of Baiyun Sag. And other geochemical discriminant methods were applied simultaneously to determine the type and source rocks of natural gas. The results show that the natural gas in the Y5 well area on the northern slope of Baiyun Sag is mainly kerogen degradation gas, mixed with a small amount of oil cracking gas. The mixture of kerogen degradation gas and a small amount of crude oil cracking gas caused the inversion of the carbon isotope sequence of ethane and propane. The natural gas in the Y5 well area mainly comes from delta–shallow lacustrine facies source rock. The high–quality reservoirs in the shallower strata accumulate natural gas generated in the early stage, and the tight reservoirs in the deeper strata mainly accumulate natural gas generated in the late stage.

Exploration practices have proven that over mature shale gas exhibits a feature of carbon isotope reversal. The geochemical statistics indicate that the wetness (C2-C5/C1-C5) of shale gas with carbon isotope reversal is less than 1.8%. In addition, the magnitude of carbon isotope reversal (δ13C1- δ13C2) for the over mature shale gas presents a parabolic variation with decreasing wetness. δ13C1-δ13C2 increases with decreasing wetness within a wetness range of 0.9% ~1.8% and then decreases with decreasing wetness at wetness < 0.9%. The CH4 cracking experiment demonstrates that CH4 polymerization occurring in the early stage of CH4 cracking is an important factor involved in isotope reversal of over mature shale gas. Moreover, δ13C1- δ13C2 decreases with an increase in experimental temperature prior to CH4 substantial cracking. The values of δ13C1 and δ13C2 tend to equalize during CH4 substantial cracking. The δ13C1-δ13C2 of mud gas present at different depths during shale gas drilling in Sichuan Basin increases initially, then decreases with further increase in the depth and finally tends to zero, with only a trace hydrocarbon gas being detectable. Statistical data suggests that the shale gas production in Sichuan Basin decreases with the decreasing δ13C1-δ13C2 value and wetness. Thus, δ13C1-δ13C2 and wetness could potentially serve as useful criteria to screen CH4 cracking degree and to determine the largest depth of natural gas exploration. Great care should be taken during shale gas exploration in deeper layers, with wetness and δ13C1-δ13C2 less than 0.2% and 1%, respectively, since very low wetness (<0.2%) and δ13C1-δ13C2 (<1%) might be indicative of CH4 substantial cracking in a geological setting.

Moose (Alces alces) are generalist herbivores but are important aquatic-terrestrial ecotone specialists. Aquatic macrophytes are a high-quality food source for moose during the summer, however their relative importance to moose diet is difficult to study. We used stable isotope analysis of carbon and nitrogen from moose hooves and forage (terrestrial plants, aquatic macrophytes, and arboreal lichen) to estimate the diet of moose at Isle Royale National Park, Michigan, USA, and to evaluate the isotopic variability along chronologies of serially sampled hooves. We hypothesized that aquatic macrophyte consumption and winter body condition (as measured by bone marrow fat content) would be greater at the eastern end of the island where aquatic habitats were most abundant. We were unable to evaluate spatial differences in aquatic macrophyte consumption, but overall, our mixing model results suggest that between 13% and 27% of summer moose diet was from aquatic sources. Among moose that died during winter, body condition was impaired and hoof δ¹⁵N (measured at the hairline) was higher at the western end of the island, where aquatic habitats are sparse. Although isotope chronologies preserved in hooves could significantly enhance our understanding of ungulate foraging ecology, interpretation of such chronologies is presently limited by our lack of knowledge pertaining to hoof growth rate and seasonal dynamics in relation to age and health. Significant isotope distinction among terrestrial plants, aquatic macrophytes, and arboreal lichens indicate that continued methodological advances in stable isotope ecology will lead to more precise estimates of the contribution of aquatic feeding to moose population dynamics.

We analyzed mineralogical characteristics, and major as well as rare earth element concentrations from a cryptotephra layer in sediments of the infilled maar of Auel (Eifel, Germany). The results of detailed geochemical analyses of clinopyroxenes and their glassy rim of the specific layer are most similar to those from the Campanian Ignimbrite (CI) Tephra occurrence in a loess section at Urluia (Romania). Both records show idiomorphic green clinopyroxenes and formation of twisted minerals up to millimeter scale. The cryptotephra in the Auel core has an age of around 39,940 yr b2k in the ELSA-20 chronology, almost identical to the latest Ar/Ar dates for the Campanian Ignimbrite/Y5 eruption. These observations suggest that parts of the CI ash cloud were transported also northwestward into Central Europe, whereas the main branch of the CI ash plume was transported from southern Italy towards the NE, E and SE.

Oxygen and hydrogen mobility are among the important characteristics for operation of solid oxide fuel cells, permselective membranes and many other electrochemical devices. This, along with other characteristics, enables reaching a high power density of solid oxide fuel cells and a high oxygen or hydrogen permeation fluxes for membranes. This work focuses on oxygen and hydrogen diffusion of mixed ionic (oxide ionic or/and protonic) – electronic conducting materials for these devices and its role in the performance. Ionic transport properties of conventional and state-of-the-art materials are reviewed.

Studies of dietary preferences of migratory species are of great importance as these species connect food webs of habitats across the migration route and thus represent trophic relationships between the spatially disjointed communities. Here we describe dietary preferences of threespine stickleback G. aculeatus in the White Sea during the spawning season using stable isotope and stomach content analyses. Both analyses indicated that during the spawning season, when sticklebacks spend most of the time in the inshore, their diet significantly consist of benthic species in contrast to the start of the spawning season when fishes migrating from the offshore are feeding on zooplankton. Also, we show that stickleback eggs contribute greatly to the diet of both male and female fishes. Using Bayesian mixing modelling we show that dietary preferences in females were broader than in males, and more variable during the spawning season. Males fed on eggs almost while guarding their nests. Both stomach contents and isotope signatures demonstrate that by the end of the spawning season sticklebacks again increase consumption of plankton, and isotope analysis proved to be more reliable tool to trace this change than stomach content analysis. Our results show that stable isotope and stomach content analyses well supplement each other in understanding of seasonal changes in dietary composition of stickleback.

Mesozoic-Palaeozoic marine carbonate rocks are important hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin (SYSB). Due to the lack of boreholes and the great heterogeneity of carbonate reservoirs, the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear. Based on seismic inversion and isotope analysis, this study explores the factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB. In this study, the log-seismic characteristics of porous carbonate reservoirs, sensitive lithology parameters, and physical property parameters are extracted and analyzed. The pre-stack simultaneous inversion technique is applied to predict the lithology properties and physical properties of the porous carbonate reservoirs. Moreover, the sedimentary of carbonate is analyzed using isotopes of carbon, oxygen, and strontium. The results indicate that porous carbonate reservoirs with porosities of 3%~5% mainly occur at the paleo-highland (Huanglong Formation and Chuanshan Formation) and the slope of paleo-highland (Hezhou Formation). The porous carbonate reservoirs of the Qixia Formation are only locally developed. In addition, the study area was dominated by a warm and humid tropical climate from the Carboniferous to Early Permian, with four sea-level eustatic fluctuation indicated by the negative and positive δ13C excursions. When the sea level fell, the study area was exposed and denuded, and the supply of terrigenous detrital was dominated, which significantly influenced the carbonate deposit and diagenesis. This study highlights that sedimentation was a key factor in controlling the quality of Carboniferous-Early Permian carbonate reservoirs. The methods proposed in this study can be used in other carbonate-dominated strata worldwide.

The hydrochemical composition of the Upper Jurassic groundwaters in the South German Mo-lasse Basin (SGMB) indicates a heterogeneous and varying hydrogeochemical evolution, which contradicts previous flow model concepts. For this study, the data of 88 Tertiary, Cretaceous and Upper Jurassic groundwater samples were investigated for hydrochemical elements, 2H/18O-H2O isotopes, 87Sr/86Sr ratios as well as δ11B values. In addition, the geochemical composition, 87Sr/86Sr and δ11B values were analysed from depth-oriented Upper Jurassic rock samples to delineate water-rock interactions in the aquifer systems. Slightly elevated 87Sr/86Sr ratios of the carbonates compared to the typical signatures of marine Upper Jurassic carbonates indicate a synsedimentary radiogenic influence due to the erosion of the adjacent Bohemian Massif. However, these values cannot explain the significant higher Sr-isotope fingerprint of the groundwaters in the central SGMB. Different water types occur in the Upper Jurassic aquifer, primarily distinguished by the dominant cations, calcium or sodium with subclasses of the major anions. The calcium-dominated groundwaters occur mainly at the western and northern margins of the SGMB. The sodi-um-dominated ion exchange groundwaters instead dominate in the central and eastern SGMB. With increasing strontium content, the 87Sr/86Sr ratios of the Upper Jurassic groundwater samples either indicate a strontium uptake by carbonate of the host rocks, or a prevailing radiogenic sig-nature. This implies a basic interaction with terrestrial or marine Tertiary sediments. The results illustrate a downward transformational fluid flow systematic via the thick Tertiary sediment cover into the Upper Jurassic carbonate formation in the SGMB, highlighting a new understanding on the evolution of the Upper Jurassic groundwaters and a basin-wide recharge mechanism.

Methane (CH4), produced endogenously in animals and plants, has recently been suggested to play a role in cellular physiology, potentially influencing the signaling pathways and regulatory mechanisms involved in nitrosative and oxidative stress responses. In addition, it has been proposed that supplementation of CH4 to organisms may be beneficial for the treatment of several diseases, including ischemia, reperfusion injury, and inflammation. However, it is still unclear if and how CH4 is produced in mammalian cells without the help of microorganisms, and how CH4 might be involved in physiological processes in humans. In this study, we provide first proof of the principle that CH4 is formed non-microbially in the human body by applying isotopically labeled methylated sulfur compounds, such as dimethyl sulfoxide (DMSO) and methionine, as carbon precursors to confirm cellular CH4 formation. A volunteer applied isotopically labeled (2H and 13C) DMSO on the skin, orally, and to blood samples. Monitoring of stable isotope values of CH4 convincingly showed the conversion of the methyl groups, as isotopically labeled CH4 was formed during all experiments. Based on these results, we consider several hypotheses about endogenously formed CH4 in humans, including physiological aspects and stress responses involving reactive oxygen species (ROS). While further and broader validation studies are needed, the results may unambiguously serve as a proof of concept for the endoge-nous formation of CH4 in humans by a radical-driven process. Furthermore, these results might encourage follow up studies to decipher the potential physiological role of CH4 and its bioactiv-ity in humans in more detail. Of particular importance is the potential to monitor CH4 as an ox-idative stress biomarker if the observed large variability of CH4 in breath air is an indicator for physiological stress responses and immune reactions. Finally, the potential role of DMSO as a radical scavenger to counteract oxidative stress caused by ROS might be considered in the health sciences. DMSO has already been investigated for many years, but its potential positive role for medical use remained highly uncertain.