Development of in situ Li isotope analysis using laser ablation quadrupole inductively coupled plasma mass spectrometry.

RATIONALE: Lithium isotope geochemistry is an important tool in the studies of Earth and planetary materials. In situ Li isotope analyses are typically performed using secondary ion mass spectrometry (SIMS) or laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS), but these instruments are not widely accessible. Here, the capability of laser ablation quadrupole ICPMS for conducting Li isotopic analyses is evaluated. METHODS: An array of MPI-DING and USGS silicate glass reference materials was analyzed repeatedly over the course of 6 months. These materials range from komatiite to rhyolite in terms of silica content (45.5-75.6 wt%) with 9-45 ppm Li. Their Li isotope compositions have been previously characterized so that matrix effects could be tested with these reference materials. Analyses were conducted using an NWR193 laser ablation system coupled to an Agilent 7900 ICPMS system. RESULTS: Analytical precision is primarily limited by Li concentration in the samples. For samples with ~9 ppm Li, the internal precision is 6‰ (2 SD, 150 µm spot diameter), whereas that for a sample with ~45 ppm Li is 4‰ (2 SD, 120 µm spot diameter). The technique is somewhat sensitive to sample matrix: samples with SiO2 content that deviates from the bracketing standard display fractionated δ7 Li, necessitating correction using a session-specific matrix correction curve. CONCLUSION: Lithium isotope analysis by ns-LA-QICPMS is worthwhile for samples with high Li concentrations and when a matrix-matched standard can be obtained. Although the precision of this method is not as high as those achievable with SIMS and LA-MC-ICPMS, it remains adequate for resolving large isotope fractionations found in natural and laboratory settings.

Potential causal associations between leisure sedentary behaviors, physical activity, sleep traits, and myopia: a Mendelian randomization study.

BACKGROUND: Myopia is the most prevalent refractive error and a growing global health concern that significantly affects visual function. Researchers have recently emphasized considerably on the influence of lifestyle on myopia incidence and development. This study investigates the relationship between leisure sedentary behaviors (LSB)/physical activity (PA)/sleep traits and myopia. METHODS: LSB, PA, and sleep trait-associated genetic variants were used as instrument variables in a Mendelian randomization (MR) study to examine their causal effects on myopia. Summary genome-wide association studies (GWASs) statistical data for LSB and PA were obtained from UK Biobank, and the data of sleep traits was obtained from UK Biobank, UK Biobank and 23andMe, and FinnGen. We used summary statistics data for myopia from MRC IEU. The MR analyses was performed using the inverse variance-weighted (IVW), MR-Egger, weighted median, and MR Pleiotropy RESidual Sum and Outlier methods. RESULTS: Computer use was genetically predicted to increase the myopia risk [IVW odds ratio (OR) = 1.057; 95% confidence interval (CI), 1.038-1.078; P = 7.04 × 10- 9]. The self-reported moderate-to-vigorous physical activity (MVPA) (IVW OR = 0.962; 95% CI, 0.932-0.993; P = 1.57 × 10- 2) and television watching (IVW OR = 0.973; 95% CI, 0.961-0.985, P = 1.93 × 10- 5) were significantly associated with a lower myopia risk. However, genetically predicted sleep traits or accelerometer-measured physical activity had no significant associations with myopia. CONCLUSION: Our results indicated that computer use is a risk factor for myopia, whereas television watching and MVPA may protect against myopia. These findings shed new light on possible strategies for reducing the prevalence of myopia.

Exploring causal correlations between inflammatory cytokines and varicose veins: A Mendelian randomization analysis.

This study aimed to investigate the causal relationship between inflammatory cytokines and the risk of varicose veins. The data were sourced from genome-wide association studies (GWAS) of European individuals. Multiple Mendelian randomization (MR) methods were used to evaluate the association between inflammatory cytokines and varicose veins. The study found significant associations between elevated levels of certain inflammatory biomarkers (e.g., CASP-8, Vascular endothelial growth factor A levels (VEGF_A)) and an increased risk of varicose veins, while others (e.g., 4EBP1, MMP-10) showed a protective effect. The MR-Egger Intercept and heterogeneity tests indicated no significant pleiotropy or heterogeneity. This comprehensive MR analysis identifies several cytokines as potential contributors to the pathogenesis of varicose veins, offering insights into novel therapeutic targets. Our findings underscore the importance of inflammation in varicose veins and suggest that targeting specific cytokines could be a promising strategy for the treatment and prevention of varicose veins.

In Situ Growing BCN Nanotubes on Carbon Fibers for Novel High-Temperature Supercapacitor with Excellent Cycling Performance.

Carbon nanomaterials have elicited much research interest in the energy storage field, but most of them cannot be used at high temperatures. Thus, a supercapacitor with high energy and desired stability at high temperatures is urgently required. Herein, BCN nanotubes (BCNNTs) with excellent performance at high temperatures are generated on carbon fibers by optimizing the ratio of B and N. The nanotubes' morphology can effectively alleviate the structural damage caused by the rapid adsorption/desorption of the electrolyte during long-time charge/discharge cycles at high temperatures, thus improving the high-temperature cycle stability. The symmetric supercapacitors that are assembled with the binder-free BCNNT electrode in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM·BF4 ) exhibited a high areal capacitance of 177.1 mF cm-2 at a current density of 5 mA cm-2 , and capacitance retention is maintained up to 86.1% for 5000 cycles at 100 °C. Moreover, the flexible supercapacitor based on BCNNTs in poly(vinylidenefluoride hexafluoropropylene)/EMIM·BF4 /succinonitrile gel electrolyte also exhibits good volumetric capacitance (1.98 mWh cm-3 at a current density of 5 mA cm-2 ) and cycling stability (92.6% retention after 200 charge/discharge cycles) at a temperature of 100 °C. This work shows that binder-free BCNNTs are promising materials for high-temperature flexible energy storage devices.

Latitude-dependent oxygen fugacity in arc magmas.

The redox state of arc mantle has been considered to be more oxidized and diverse than that of the mid-ocean ridge, but the cause of the variation is debated. We examine the redox state of the Cenozoic global arc mantle by compiling measured/calculated fO2 of olivine-hosted melt inclusions from arc magma and modeled fO2 based on V/Sc and Cu/Zr ratios of arc basaltic rocks. The results indicate that the redox state of Cenozoic arc mantle is latitude dependent, with less oxidized arc mantle in the low latitudes, contrasting with a near constant across-latitude trend in the mid-ocean ridges. We propose that such a latitude-dependent pattern in the arc mantle may be controlled by the variation in the redox state of subducted sediment, possibly related to a latitudinal variation in the primary production of phytoplankton, which results in more organic carbon and sulfide deposited on the low-latitude ocean floor. Our findings provide evidence for the impact of the surface environment on Earth's upper mantle.

Potential Causal Association between Depression and Oral Diseases: A Mendelian Randomization Study.

BACKGROUND: Globally, oral diseases are common, pose an economic burden, and significantly decline the quality of life of affected individuals. Recently, researchers have substantially highlighted the effect of depression on oral disease incidence and development. In this study, we elucidated the correlation between depression and oral diseases. METHODS: Using two-sample Mendelian randomization (MR), the association between depression and the risk of 17 oral diseases was evaluated. Three methods were used to perform MR analysis: the inverse variance-weighted, weighted median, and MR-Egger methods. Furthermore, Cochran's Q test, MR-Egger intercept test, MR Pleiotropy RESidual Sum and Outlier test, and leave-one-out analysis were performed to analyze sensitivity. RESULTS: After implementing multiple test corrections, we observed that genetic susceptibility to depression was associated with an increased risk of mouth ulcers, toothache, loose teeth, bleeding gums, painful gums, chronic periodontitis, chronic tonsil and adenoid diseases, peritonsillar abscess, and excessive tooth attrition. However, a causal relationship between depression and other oral diseases was not observed. Sensitivity analysis confirmed the robustness of the results. CONCLUSIONS: We confirmed the causal relationship between depression and several oral diseases, thereby providing a novel viewpoint on the prevention and treatment of oral diseases. Our findings suggest the integration of depression control into routine clinical care to enhance the effectiveness of oral disease treatment.

Venus' light slab hinders its development of planetary-scale subduction.

Terrestrial planet Venus has a similar size, mass, and bulk composition to Earth. Previous studies proposed that local plume-induced subduction existed on both early Earth and Venus, and this prototype subduction might initiate plate tectonics on Earth but not on Venus. In this study, we simulate the buoyancy of submerged slabs in a hypothesized 2-D thermo-metamorphic model. We analyze the thermal state of the slab, which is then used for calculating density in response to thermal and phase changes. The buoyancy of slab mantle lithosphere is primarily controlled by the temperatures and the buoyancy of slab crust is dominated by metamorphic phase changes. Difference in the eclogitization process contributes most to the slab buoyancy difference between Earth and Venus, which makes the subducted Venus' slab consistently less dense than Earth's. The greater chemical buoyancy on Venus, acting as a resistance to subduction, may have impeded the transition into self-sustained subduction and led to a different tectonic regime on Venus. This hypothesis may be further tested as more petrological data of Venus become available, which will further help to assess the impact of petro-tectonics on the planet's habitability.

Boron carbonitride with tunable B/N Lewis acid/base sites for enhanced electrocatalytic overall water splitting.

In-depth research on energy storage and conversion is urgently needed; thus, water splitting has become a possible method to achieve sustainable energy utilization. However, traditional carbon material with high graphitization degree exhibits a relatively low electrocatalytic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activity as it is electrochemically inert. In this work, according to the Lewis theory of acids and bases and the density functional theory (DFT) results, which show that the enriched heteroatom of B/N in the boron carbonitride (BCN) system may introduce stronger adsorption strength of OH*/H2O, respectively, we have designed and synthesized self-supporting BCN materials with different enrichment degrees of B/N (B-BCN/N-BCN) using carbon paper as substrate. Furthermore, by adjusting the contents of B and N, the optimum electrocatalytic performance of overall water splitting was obtained in which the onset voltage of water splitting on B-BCN//N-BCN was lower than 1.60 V. Our strategy of synthesizing materials with different heteroatom enrichment to improve the electronic environment of materials has opened up new opportunities for developing efficient metal-free electrocatalysts.

Boron Carbonitride Lithium-Ion Capacitors with an Electrostatically Expanded Operating Voltage Window.

Lithium-ion capacitors (LICs) have emerged as attractive energy storage devices to bridge the gap between lithium-ion batteries and supercapacitors. While the distinct charge storage kinetics between the anode and the cathode is still a challenge to the widespread application of LICs, the key to improving the energy density of these devices is to widen the operating voltage window and balance the mismatch of the electrode kinetics. To this end, we propose a strategy based on electrostatic attraction by adjusting the B and N atom contents of boron carbonitride (BCN) electrode materials to alter their electronegativities and successfully prepared B-rich and N-rich BCN nanotubes (BCNNTs) via a facile solid-phase synthesis approach. The B-rich BCN (B-BCN) cathode and N-rich BCN (N-BCN) anode noticeably enhance the adsorption of anions and cations, promoting a matching degree between the anode and cathode. In particular, the rationally designed B-BCN//N-BCN LIC achieves a maximum voltage range of 4.8 V, setting a new record for LICs. Furthermore, the energy density reaches up to 200 Wh kg-1 (based on the total mass of cathodic and anodic active materials). Density functional theory calculations provided insight into the mechanism underlying our strategy of widening the voltage range. Our philosophy provides new design guidelines and alternatives for identifying and optimizing high-performance electrodes for energy storage devices.

Nb/Ta systematics in arc magma differentiation and the role of arclogites in continent formation.

The surfaces of rocky planets are mostly covered by basaltic crust, but Earth is unique in that it also has extensive regions of felsic crust, manifested in the form of continents. Exactly how felsic crust forms when basaltic magmas are the dominant products of melting the mantles of rocky planets is unclear. A fundamental part of the debate is centered on the low Nb/Ta of Earth's continental crust (11-13) compared to basalts (15-16). Here, we show that during arc magma differentiation, the extent of Nb/Ta fractionation varies with crustal thickness with the lowest Nb/Ta seen in continental arc magmas. Deep arc cumulates (arclogites) are found to have high Nb/Ta (average ~19) due to the presence of high Nb/Ta magmatic rutiles. We show that the crustal thickness control of Nb/Ta can be explained by rutile saturation being favored at higher pressures. Deep-seated magmatic differentiation, such as in continental arcs and other magmatic orogens, is thus necessary for making continents.

Band gap-Tunable Porous Borocarbonitride Nanosheets for High Energy-Density Supercapacitors.

Band gap-tunable porous borocarbonitride (BCN) nanosheets were successfully fabricated with cheap and readily available precursors by annealing and exfoliating. The band gap of the as-prepared BCN materials ranges from 5.5 to 1.0 eV; these samples exhibit beneficial structural features suitable for the application in supercapacitors. Especially, the BCN material with a band gap of 1.0 eV exhibits a great specific surface area (600.9 m2 g-1), massive active sites, and excellent conductivity (10.8 S m-1). In addition, this example displays great specific capacitance (464.5 F g-1), excellent cycle stability (98.5% performance retention after 10 000 cycles), and ultrahigh energy density (50.4 W h kg-1, in 1 M Et4NBF4 electrolyte). This excellent electrochemical performance and facile effective synthesis of band gap-tunable BCN materials will provide a promising strategy for configuring nanostructured multiple compound electrodes for other energy storage and conversion devices.

Volcanic ash as a driver of enhanced organic carbon burial in the Cretaceous.

On greater than million year timescales, carbon in the ocean-atmosphere-biosphere system is controlled by geologic inputs of CO2 through volcanic and metamorphic degassing. High atmospheric CO2 and warm climates in the Cretaceous have been attributed to enhanced volcanic emissions of CO2 through more rapid spreading at mid-ocean ridges and, in particular, to a global flare-up in continental arc volcanism. Here, we show that global flare-ups in continental arc magmatism also enhance the global flux of nutrients into the ocean through production of windblown ash. We show that up to 75% of Si, Fe and P is leached from windblown ash during and shortly after deposition, with soluble Si, Fe and P inputs from ash alone in the Cretaceous being higher than the combined input of dust and rivers today. Ash-derived nutrient inputs may have increased the efficiency of biological productivity and organic carbon preservation in the Cretaceous, possibly explaining why the carbon isotopic signature of Cretaceous seawater was high. Variations in volcanic activity, particularly continental arcs, have the potential of profoundly altering carbon cycling at the Earth's surface by increasing inputs of CO2 and ash-borne nutrients, which together enhance biological productivity and burial of organic carbon, generating an abundance of hydrocarbon source rocks.