Adsorption and reversible detection of toxic halogens gases at room temperature by two-dimensional Al2SSe for occupational sustainability

International audienceCurrent treatment for inhalational halogens poisoning involves providing supportive care, which includes administering humidified oxygen and managing the airway. Since toxic effects of halogens cannot be reversed, sensors with high sensitivity and good reversibility for detecting the relatively lower concentration yet noxious halogens becomes particularly significant and enticing. Herein, the structural and optoelectronic properties of toxic F2 and Cl2 gas molecules adsorbed on highly stable Al2SSe monolayer have been systematically studied by means of first-principles calculations based on density functional theory (DFT). Favorable adsorption sites of said molecules on Al2SSe were carefully examined. The relatively high, negative adsorption energy for F2 and Cl2 indicate that the adsorption process is exothermic and the molecules could be stably adsorbed on Al2SSe monolayer. This characteristic, combined with the substantial charge transfer (0.15-0.55 |e|), drastic change in work function, complete reversibility due to recovery time in 10-1 s scale and distinct optical response, render Al2SSe monolayer a viable option for utilization as either surface work functions transistor or optical chemical resistor for detecting these gases. Pearson correlation coefficient (PCC) analysis of theoretical recovery time and response value indicates that band gap change and electron transfer are the primary influencing factors. Selectivity analysis reveals that common compound forms of halogens and atmospheric molecules such as HF, HCl, N2, O2, H2 and H2O are either physically adsorbed or inert with extremely low adsorption energies on Al2SSe, prompting high F2 and Cl2 selectivity. These outcomes acclaim the exciting prospects of developing Al2SSe monolayer for specific, occupational related ultrahigh-sensitivity F2 and Cl2 sensing nanodevices

Quality of life between home-based and outpatient pulmonary rehabilitation in patients after surgical resection for lung cancer: protocol for a prospective, single-blind, randomised controlled trial

Introduction Lung cancer remains a highly fatal disease. Surgical resection has been proven to be the most effective treatment for early-stage lung cancer. The conventional hospital-based pulmonary rehabilitation (PR) is shown to reduce symptoms, improve exercise capacity and impact the quality of life (QoL) for lung cancer patients. To date, scientific evidence on the effectiveness of home-based PR for patients with lung cancer following surgery is scarce. We aim to explore if home-based PR is non-inferior to outpatient PR for patients with lung cancer following surgical resection.Methods and analysis This study is a two-arm, parallel-group, assessor-blind, single-centre, randomised controlled trial. Participants will be recruited from West China Hospital, Sichuan University and randomly allocated to either an outpatient group or a home-based group at a ratio of 1:1. The PR programme involves self-management and exercises. The exercise includes warm-up (10 min), aerobic training (20 min), resistance training (15 min) and cool-down (10 min), lasting 4 weeks, with two sessions per week either at home or in the outpatient setting. The intensity will be adjusted according to the modified Borg rating of perceived exertion and heart rate before and after each exercise session. The primary outcome is QoL measured by EORTC QLQ-C30 & LC 13 after an intervention. Secondary outcomes include physical fitness measured by a 6 min walk test and stair-climbing test and symptom severity measured by patient-reported questionnaires and pulmonary function. The main hypothesis is that home-based PR is non-inferior to outpatient PR for patients with lung cancer following surgical resection.Ethics and dissemination The trial has been approved by the Ethical Committee of West China Hospital and is also registered with the Chinese Clinical Trial Registry. The results of this study will be disseminated through peer-reviewed publications and presentations at national and international conferences.Trial registration number ChiCTR2100053714

Prediction of stable silver selenide-based energy materials sustained by rubidium selenide alloying

International audienceSilver selenide (Ag2Se) is a ductile material with a low lattice thermal conductivity that can be a valuable substitute for both PbSe and Bi2Se3 for Pb toxicity free and Bi scarcity. However, its narrow band gap in bulk phase and low dopability for its monolayer form, limit the potential of Ag2Se as a practical energy converter. Whereas earlier halogenated Ag2Se studies show a greatly elevated Seebeck coefficient due to the broadened band gap, the approach yielded little improvement for the dopability of its monolayer. Motivated by the positive effects of lighter alkalis on optical and thermoelectric responses of semiconductors, the thermal stability, thermoelectric and luminescence properties of bulk and two-dimensional (2D) RbxAg1-xSe phases were comprehensively investigated using a global evolutionary algorithm and density functional theory (DFT), followed by semiclassical Boltzmann transport formalism. The electronic structure and chemical bonding (COHP) results show that these structures are thermodynamically and mechanically stable for the entire Rb composition range, with a band gap that increases monotonically with Rb content, and is in the range of 1.41-2.75 eV within the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional, which demonstrates the possibility of their laboratory synthesis. Satisfactory optical absorption in the order of 10(4)-10(5) cm(-1) is seen spanning the visible and ultraviolet regions. The fundamentally low lattice thermal conductivity below 1.0 W m(-1) K-1 throughout the temperature range studied is attributed to the complex structure and relatively low sound velocity. Under optimal hole concentration, their thermoelectric figure of merit (ZT) and power factor (PF) can reach magnitudes of 0.6-1.0 and 0.68-24.2 mW m(-1) K-2, respectively, between 300 and 1000 K. The monolayer Rb2Ag2Se2 in particular stands out with its high ZT and improved dopability when compared to those of the monolayer Ag2Se. Comparison of the band edge positions with the redox potential of water indicates that the bulk Rb2Ag2Se2 phase exhibits satisfactory photocatalytic activity in seawater splitting. This work validates that the grinding together of stoichiometric quantities of Rb2Se and Ag2Se is an effective alternative for improving the dopability of monolayer Ag2Se and engineering RbxAg1-xSe, with focused characteristics to suit environmental conditions

Pinocembrin Protects Blood-Brain Barrier Function and Expands the Therapeutic Time Window for Tissue-Type Plasminogen Activator Treatment in a Rat Thromboembolic Stroke Model

Tissue-type plasminogen activator (t-PA) remains the only approved therapy for acute ischemic stroke but has a restrictive treatment time window of 4.5 hr. Prolonged ischemia causes blood-brain barrier (BBB) damage and increases the incidence of hemorrhagic transformation (HT) secondary to reperfusion. In this study, we sought to determine the effect of pinocembrin (PCB; a pleiotropic neuroprotective agent) on t-PA administration-induced BBB damage in a novel rat thromboembolic stroke model. By assessing the leakage of Evans blue into the ischemic hemisphere, we demonstrated that PCB pretreatment 5 min before t-PA administration significantly reduced BBB damage following 2 hr, 4 hr, 6 hr, and even 8 hr ischemia. Consistently, PCB pretreatment significantly decreased t-PA infusion-resulting brain edema and infarction volume and improved the behavioral outcomes following 6 hr ischemia. Mechanistically, PCB pretreatment inhibited the activation of MMP-2 and MMP-9 and degradation of tight junction proteins (TJPs) occludin and claudin-5 in the ischemic hemisphere. Moreover, PCB pretreatment significantly reduced phosphorylation of platelet-derived growth factor receptor α (PDGFRα) as compared with t-PA alone. In an in vitro BBB model, PCB decreased transendothelial permeability upon hypoxia/aglycemia through inhibiting PDGF-CC secretion. In conclusion, we demonstrated that PCB pretreatment shortly before t-PA infusion significantly protects BBB function and improves neurological outcomes following prolonged ischemia beyond the regular 4.5 hr t-PA time window. PCB pretreatment may represent a novel means of increasing the safety and the therapeutic time window of t-PA following ischemic stroke

Human disturbance rather than habitat factors drives plant community assembly and diversity patterns in a semiarid region

Human activities may lead to land degradation, and then influences diversity and function of ecosystems. Understanding the plant community assembly processes and diversity patterns along human activities-related gradients are an important facet of ecological research and can be used to reveal vegetation dynamics under land degradation on the Loess Plateau. In this study, we evaluated the net relatedness index, phylogenetic diversity, and species diversity along habitat (elevation, slope, aspect, residential distance, succession time) and comprehensive disturbance gradients on the Loess Plateau, China. We found that community assembly processes were mainly influenced by slope and succession time linked to human activity. Study regions with slope >20 degrees or succession time > 35 years showed no environmental filtering effect during community assembly processes, because these region usually had fewer cropland development activities. Although phylogenetic and species diversity showed a dissimilar pattern along gradients, we also summarized human activities rather than habitat factors drive diversity patterns. In summary, we demonstrate that human activities mainly influence community assembly processes and diversity patterns. With reduction of human disturbance in future, land degradation will be ameliorated on Loess Plateau

Association between ACYP2

Abstract Background Kidney cancer is the predominant form of malignancy of the kidney and accounts for approximately 3%–4% of all cancers. Renal cell cancer (RCC) represents more than 85% of kidney cancer. It has been reported that genetic factors may predispose individuals to RCC. This study evaluated the association between Acylphosphatase 2 (ACYP2) gene polymorphisms and RCC risk in the Han Chinese population. Methods Twelve single‐nucleotide polymorphisms (SNPs) in ACYP2 were genotyped using the Agena MassARRAY platform from 293 RCC patients and 495 controls. The Chi‐squared test, genetic models, haplotype, and stratification analyses were used to evaluate the association between SNPs and the risk of RCC. The relative risk was estimated using the odds ratio (OR) and 95% confidence interval (CI). Results We observed that the rs6713088 allele G (OR = 1.26, 95% CI: 1.03–1.53, p = .023) and rs843711 allele T (OR = 1.29, 95% CI: 1.06–1.57, p = .010) were associated with increased RCC risk. Genetic model analyses found that rs843711 was significantly associated with an increased RCC risk under the recessive model and log‐additive model after adjusting for age and gender. Haplotype analysis showed that the haplotype “TTCTCGCC” (OR = 0.67, 95% CI: 0.48–0.94, p = .021) was associated with a decreased risk of RCC in the Han Chinese population. Stratification analysis also found that rs6713088 and rs843711 were significantly associated with increased RCC risk. Conclusion In summary, the results suggested that ACYP2 polymorphisms could be used as a genetic marker for RCC. Additional functional and association studies are required to validate our results

Stretchable AgX (X = Se, Te) for Efficient Thermoelectrics and Photovoltaics

Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag 2S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional Ag x Se 1- x and Ag x Te 1- x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P2 12 12 1-Ag 8Se 4 and P2 1/ c-Ag 8Te 4 structures. Recently reported metastable AgTe 3 was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/ nmm-Ag 4Se 2 and C2-Ag 8Te 4 phases. Orthorhombic Ag 8Se 4 crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag 4Se 2 monolayer. Interestingly, metallic P2 1/ c-Ag 8Te 4 changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young's modulus ( E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11-28%), relatively high n(0) (1.59-1.93), and sizable α(ω) (10 4-10 5 cm -1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag-Se was found to rise from approximately 0.15-0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies

Stretchable AgX (X = Se, Te) for Efficient Thermoelectrics and Photovoltaics

Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag 2S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional Ag x Se 1- x and Ag x Te 1- x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P2 12 12 1-Ag 8Se 4 and P2 1/ c-Ag 8Te 4 structures. Recently reported metastable AgTe 3 was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/ nmm-Ag 4Se 2 and C2-Ag 8Te 4 phases. Orthorhombic Ag 8Se 4 crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag 4Se 2 monolayer. Interestingly, metallic P2 1/ c-Ag 8Te 4 changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young's modulus ( E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11-28%), relatively high n(0) (1.59-1.93), and sizable α(ω) (10 4-10 5 cm -1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag-Se was found to rise from approximately 0.15-0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies

Stretchable AgX (X = Se, Te) for Efficient Thermoelectrics and Photovoltaics

Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag2S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional AgxSe1–x and AgxTe1–x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P212121-Ag8Se4 and P21/c-Ag8Te4 structures. Recently reported metastable AgTe3 was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/nmm-Ag4Se2 and C2–Ag8Te4 phases. Orthorhombic Ag8Se4 crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag4Se2 monolayer. Interestingly, metallic P21/c-Ag8Te4 changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young’s modulus (E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11–28%), relatively high n(0) (1.59–1.93), and sizable α(ω) (104–105 cm–1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag–Se was found to rise from approximately 0.15–0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies