Tin-mediated carbon-confined Pt_(3)Co ordered intermetallic nanoparticles as highly efficient and durable oxygen reduction electrocatalysts for rechargeable zinc-air batteries

The development of electrocatalysts for the oxygen reduction reaction(ORR) that bears high selectivity,exceptional activity,and long-term stability is crucial for advancing various green energy technologies.Intermetallics composed of platinum and transition metals are considered to be promising candidates for this purpose.However,they typically face challenges such as unfavorable intrinsic activity and a propensity for particle aggregation,diminishing their ORR performance.Against this backdrop,we present our findings on a N-doped carbon confined Pt_(3)Co intermetallic doped with p-block metal tin(Pt_(3)Co_(x)Sn_(1-x)/NC).The introduction of Sn induces lattice strain due to its larger atomic size,which leads to the distortion of the Pt_(3)Co lattice structure,while the coupling of carbon polyhedra inhibits the particle aggregation.The optimized Pt_(3)Co_(0.8)Sn_(0.2)/NC catalyst demonstrates an impressive half-wave potential of 0.86 V versus RHE,surpassing both Pt_(3)Co/NC and Pt_(3)Sn/NC catalysts.Moreover,the Pt_(3)Co_(0.8)Sn_(0.2)/NC exhibits a mass-specific activity as high as 1.4 A mg_(Pt)^(-1),ranking it in the top level among the intermetallicsbased ORR electrocatalysts.When further employed as a cathode material in a self-assembled zinc-air battery,it shows stable operation for over 80 h.These results underscore the significant impact of lattice strain engineering through the strategic doping of p-block metal in the carbon-confined Pt_(3)Co intermetallic,thereby enhancing the catalytic efficiency for the ORR.

Intelligent decision-making method of TBM operating parameters based on multiple constraints and objective optimization

The decision-making method of tunnel boring machine(TBM)operating parameters has a significant guiding significance for TBM safe and efficient construction,and it has been one of the TBM tunneling research hotspots.For this purpose,this paper introduces an intelligent decision-making method of TBM operating parameters based on multiple constraints and objective optimization.First,linear cutting tests and numerical simulations are used to investigate the physical rules between different cutting parameters(penetration,cutter spacing,etc.)and rock compressive strength.Second,a dual-driven mapping of rock parameters and TBM operating parameters based on data mining and physical rules of rock breaking is established with high accuracy by combining rock-breaking rules and deep neural networks(DNNs).The decision-making method is established by dual-driven mapping,using the effective rock-breaking capacity and the rated value of mechanical parameters as constraints and the total excavation cost as the optimization objective.The best operational parameters can be obtained by searching for the revolutions per minute and penetration that correspond to the extremum of the constrained objective function.The practicability and effectiveness of the developed decision-making model is verified in the SecondWater Source Channel of Hangzhou,China,resulting in the average penetration rate increasing by 11.3%and the total cost decreasing by 10%.

Cardiopulmonary prognosis of prophylactic endotracheal intubation in patients with upper gastrointestinal bleeding undergoing endoscopy

BACKGROUND:It is controversial whether prophylactic endotracheal intubation(PEI)protects the airway before endoscopy in critically ill patients with upper gastrointestinal bleeding(UGIB).The study aimed to explore the predictive value of PEI for cardiopulmonary outcomes and identify high-risk patients with UGIB undergoing endoscopy.METHODS:Patients undergoing endoscopy for UGIB were retrospectively enrolled in the eICU Collaborative Research Database(eICU-CRD).The composite cardiopulmonary outcomes included aspiration,pneumonia,pulmonary edema,shock or hypotension,cardiac arrest,myocardial infarction,and arrhythmia.The incidence of cardiopulmonary outcomes within 48 h after endoscopy was compared between the PEI and non-PEI groups.Logistic regression analyses and propensity score matching analyses were performed to estimate effects of PEI on cardiopulmonary outcomes.Moreover,restricted cubic spline plots were used to assess for any threshold effects in the association between baseline variables and risk of cardiopulmonary outcomes(yes/no)in the PEI group.RESULTS:A total of 946 patients were divided into the PEI group(108/946,11.4%)and the non-PEI group(838/946,88.6%).After propensity score matching,the PEI group(n=50)had a higher incidence of cardiopulmonary outcomes(58.0%vs.30.3%,P=0.001).PEI was a risk factor for cardiopulmonary outcomes after adjusting for confounders(odds ratio[OR]3.176,95%confidence interval[95%CI]1.567-6.438,P=0.001).The subgroup analysis indicated the similar results.A shock index>0.77 was a predictor for cardiopulmonary outcomes in patients undergoing PEI(P=0.015).The probability of cardiopulmonary outcomes in the PEI group depended on the Charlson Comorbidity Index(OR 1.465,95%CI 1.079-1.989,P=0.014)and shock index>0.77(compared with shock index≤0.77[OR 2.981,95%CI 1.186-7.492,P=0.020,AUC=0.764]).CONCLUSION:PEI may be associated with cardiopulmonary outcomes in elderly and critically ill patients with UGIB undergoing endoscopy.Furthermore,a shock index greater than 0.77 could be used as a predictor of a worse prognosis in patients undergoing PEI.

Multilevel optoelectronic hybrid memory based on N-doped Ge_(2)Sb_(2)Te_(5)film with low resistance drift and ultrafast speed

Multilevel phase-change memory is an attractive technology to increase storage capacity and density owing to its high-speed,scalable and non-volatile characteristics.However,the contradiction between thermal stability and operation speed is one of key factors to restrain the development of phase-change memory.Here,N-doped Ge_(2)Sb_(2)Te_(5)-based optoelectronic hybrid memory is proposed to simultaneously implement high thermal stability and ultrafast operation speed.The picosecond laser is adopted to write/erase information based on reversible phase transition characteristics whereas the resistance is detected to perform information readout.Results show that when N content is 27.4 at.%,N-doped Ge_(2)Sb_(2)Te_(5)film possesses high ten-year data retention temperature of 175℃and low resistance drift coefficient of 0.00024 at 85℃,0.00170 at 120℃,and 0.00249 at 150℃,respectively,owing to the formation of Ge–N,Sb–N,and Te–N bonds.The SET/RESET operation speeds of the film reach 520 ps/13 ps.In parallel,the reversible switching cycle of the corresponding device is realized with the resistance ratio of three orders of magnitude.Four-level reversible resistance states induced by various crystallization degrees are also obtained together with low resistance drift coefficients.Therefore,the N-doped Ge_(2)Sb_(2)Te_(5)thin film is a promising phase-change material for ultrafast multilevel optoelectronic hybrid storage.

Porous Carbon Architecture Assembled by Cross-Linked Carbon Leaves with Implanted Atomic Cobalt for High-Performance Li-S Batteries

The practical application of lithium-sulfur batteries is severely hampered by the poor conductivity,polysulfide shuttle effect and sluggish reaction kinetics of sulfur cathodes.Herein,a hierarchi-cally porous three-dimension(3D)carbon architecture assembled by cross-linked carbon leaves with implanted atomic Co-N4 has been deli-cately developed as an advanced sulfur host through a SiO_(2)-mediated zeolitic imidazolate framework-L(ZIF-L)strategy.The unique 3D architectures not only provide a highly conductive network for fast electron transfer and buffer the volume change upon lithiation-delithi-ation process but also endow rich interface with full exposure of Co-N4 active sites to boost the lithium polysulfides adsorption and conversion.Owing to the accelerated kinetics and suppressed shuttle effect,the as-prepared sulfur cathode exhibits a superior electrochemical perfor-mance with a high reversible specific capacity of 695 mAh g^(−1) at 5 C and a low capacity fading rate of 0.053%per cycle over 500 cycles at 1 C.This work may provide a promising solution for the design of an advanced sulfur-based cathode toward high-performance Li-S batteries.

Energy-level dependent H_2_O_2 production on metal-free,carbon-content tunable carbon nitride photocatalysts

Light-driven production of H2O2 from water and molecular oxygen could be a promising way for obtaining both solar fuels and fundamental chemicals. During that process, the H2O2 yield is strongly dependent on the reaction pathway associated with two-electron reduction of dioxygen by the photo-generated electrons. Herein, we synthesized a series of metal-free, carbon-content tunable carbon nitride photocatalysts（named C3N4-Carbon） by a facile hydrothermal reaction and subsequent thermal treatment at appropriate temperatures. The energy levels of the C3N4-Carbon catalysts vary with the carbon doping level, which is conveniently tuned by changing the initial glucose concentration during the hydrothermal reaction. The surface carbon species evolve with the carbon content and the nitrogen atoms in the structure of carbon nitride are partially substituted by foreign carbon atoms based on XPS measurements. The optimal catalyst leads to the highest H2O2 yield of 1271 μmol L-1 in an acidic aqueous solution（pH 3） after a reaction period of 4 h, twice higher than the pristine C3N4. In addition, the largest formation rate constant and the smallest decomposition rate constant of H2O2 are obtained on the optimal one according to the kinetics analyses. The decomposition tests of H2O2 indicate that the formation rate could be a dominant factor impacting the H2O2 yield. The conduction band position of the optimal catalyst is positively shifted to 0.06 V versus RHE, which is more favorable to the reduction of dioxygen to H2O2（O2/H2O2 at 0.69 V versus RHE）. The positive shift of valence band also improves hole collection and leads to enhanced formation of H2O2.

Inner Co Synergizing Outer Ru Supported on Carbon Nanotubes for Efficient pH-Universal Hydrogen Evolution Catalysis

Exploring highly active but inexpensive electrocatalysts for the hydrogen evolution reaction(HER)is of critical importance for hydrogen production from electrochemical water splitting.Herein,we report a multicomponent catalyst with exceptional activity and durability for HER,in which cobalt nanoparticles were in-situ confined inside bamboo-like carbon nanotubes(CNTs)while ultralow ruthenium loading(~2.6μg per electrode area~cm^(−2))is uniformly deposited on their exterior walls(Co@CNTsǀRu).The atomic-scale structural investigations and theoretical calculations indicate that the confined inner Co and loaded outer Ru would induce charge redistribution and a synergistic electron coupling,not only optimizing the adsorption energy of H intermediates(ΔGH*)but also facilitating the electron/mass transfer.The as-developed Co@CNTsǀRu composite catalyst requires overpotentials of only 10,32,and 63 mV to afford a current density of 10 mA cm^(−2) in alkaline,acidic and neutral media,respectively,representing top-level catalytic activity among all reported HER catalysts.The current work may open a new insight into the rational design of carbon-supported metal catalysts for practical applications.

Functions of silicon in plant drought stress responses

Silicon(Si),the second most abundant element in Earth’s crust,exerts beneficial effects on the growth and productivity of a variety of plant species under various environmental conditions.However,the benefits of Si and its importance to plants are controversial due to differences among the species,genotypes,and the environmental conditions.Although Si has been widely reported to alleviate plant drought stress in both the Si-accumulating and nonaccumulating plants,the underlying mechanisms through which Si improves plant water status and maintains water balance remain unclear.The aim of this review is to summarize the morphoanatomical,physiological,biochemical,and molecular processes that are involved in plant water status that are regulated by Si in response to drought stress,especially the integrated modulation of Si-triggered drought stress responses in Si accumulators and intermediate-and excluder-type plants.The key mechanisms influencing the ability of Si to mitigate the effects of drought stress include enhancing water uptake and transport,regulating stomatal behavior and transpirational water loss,accumulating solutes and osmoregulatory substances,and inducing plant defense-associated with signaling events,consequently maintaining whole-plant water balance.This study evaluates the ability of Si to maintain water balance under drought stress conditions and suggests future research that is needed to implement the use of Si in agriculture.Considering the complex relationships between Si and different plant species,genotypes,and the environment,detailed studies are needed to understand the interactions between Si and plant responses under stress conditions.

Research and Optimization of GPSR Routing Protocol for Vehicular Ad-Hoc Network

Security is one of the most critical issues to Vehicular Ad-hoc Networks (VANETs) since the information transmitted is asynchronous and distributed. Vulnerability and instability are two of the challenges remain to be addressed by the research community and the industry. In this paper, we first proposed a trust reliability based model and extended the GPSR protocol to TM-GPSR protocol. Then, we improved the LET-GPSR protocol based on the link connection time prediction. On this basis, combined the decision index of the TM-GPSR and LET-GPSR protocols, we proposed the RC-GPSR routing protocol. We built the standard testing platform on the NS2 and SUMO, the average end-to-end delay and packet delivery rate of GPSR protocol and the three updates protocols under different node density, node speed, and malicious node ratio are simulated and evaluated. The results showed that under the same conditions, compared with GPSR protocol, RC-GPSR protocol has a lower average end-to-end delay and a higher packet delivery rate, which effectively improves the link stability and security.

Glutamate oxidase-integrated biomimetic Fe_(3)O_(4) hybrids as cascade nanozymes for glutamate detection

Herein,a new nanozyme/natural enzyme hybrid biosensor was established for ultrasensitive l-glutamic acid(L-Glu)detection.The Fe_(3)O_(4) nanoparticles with peroxidase-like activity and stability was used as a nanozyme and carrier for immobilizing l-Glutamate oxidase(GLOD)through Schiffff base reaction to construct a chem-enzyme cascade detector.The resultant Fe_(3)O_(4)-GOLD exhibited a wide linear range(10−500μM)and a low detection limit of 6.03μM for L-Glu detection.Furthermore,the Fe_(3)O_(4)-GOLD exhibited excellent pH stability,thermal stability,reusability and storage stability.After repeated nine cycles,Fe_(3)O_(4)-GOLD still retained 70%of its initial activity.Meanwhile,Fe_(3)O_(4)-GOLD maintained 50%of its initial activity after storage for 20 days,while free GLOD only retained 20%of its initial activity.This strategy of integrating biomimetic Fe 3 O4 and natural enzymes for cascade catalysis makes it possible to design an efficient and stable chemo-enzyme composite catalysts,which are promising for applications in biosensing and biomimetic catalysis.

Effect of frequent blood pressure measurements after discharge on clinical outcomes in ischemic stroke patients

To the Editor:Stroke is a major cause of death and longterm serious disability in adults worldwide.Hypertension is the most important modifiable risk factor for primary and secondary prevention of stroke.[1]Even a modest reduction in clinical blood pressure(BP)of approximately 10/5 mmHg is associated with a significant 30%risk reduction of adverse clinical events.While clinical evidence strongly advocated the effectiveness of managing BP to reduce adverse outcomes after ischemic stroke,[2]the management and control of BP in ischemic stroke patients after discharge remain poor.

Selective cyclohexane oxidation enhancement by electronic structures regulation of metal-poly(ionic liquid)s

Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane.Characterization analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial catalysts.Compared with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil yield.More interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst.Therefore,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.

TM-N_(2)O_(2)C_(x)单原子催化剂的设计及电催化CO_(2)还原研究

电催化二氧化碳还原反应(CO_(2)RR)被认为是一种潜在的碳循环技术,因为它可以利用CO_(2)作为资源在温和条件下生产高附加值燃料和化学品.因此,开发高效的二氧化碳还原反应催化剂极其重要.本文设计了一系列TM-N_(2)O_(2)C_(x)(TM=Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn)单原子催化剂,并利用密度函数理论研究了其对CO_(2)RR的催化活性.这些TM-N_(2)O_(2)C_(x)催化剂在相对较低的过电位下对三种不同的产物,包括CH_(4)、CO和HCOOH,表现出优异的CO_(2)RR产品选择性,其中ScN_(2)O_(2)C_(x)、Mn-N_(2)O_(2)C_(x)、Zn-N_(2)O_(2)C_(x)的CO_(2)RR产品是CO,V-N_(2)O_(2)C_(x)的产品是CH_(4),而其他六种催化剂会产生HCOOH.此外,该研究还揭示了CH_(4)形成的最佳途径,即*+CO_(2)→C*OOH→C*O+H_(2)O→C*HO→C*HOH→C*H+H_(2)0→C*H_(2)→C*H_(3)→*+CH_(4).总之,TMN_(2)O_(2)C_(x)催化剂对电催化CO_(2)RR表现出较高的催化活性,这为实验合成这些有前景的CO_(2)RR催化剂提供了有价值的信息.

A dual enzyme-phosphate hybrid nanoflower for glutamate detection

The enzyme hybrid nanoflower has gained interests in biosensors due to their simple synthesis and high efficiency.In this study,glutamate oxidase(GLOX)and horseradish peroxidase(HRP)hybrid nanoflowers(GLOX&HRP-HNFs)were successfully prepared for the detection of glutamic acid(Glu).The effects of the synthesis conditions on the activity of GLOX&HRP-HNFs were investigated.Results revealed that the maximum activity of GLOX&HRP-HNFs was under 4 mM phosphate radical,2.5 mM MnSO4,0.04 mg/mL GLOX,and 0.16 mg/mL HRP.After immobilization,no significant differences were observed in optimum pH and temperature values of the GLOX and HRP.The GLOX&HRP-HNFs exhibited higher storage stability and resistance to organic solvents than free GLOX and HRP.Additionally,the GLOX&HRP-HNFs maintained 69%of its primary activity after 6 cycles.More important,the GLOX&HRP-HNFs exhibited a good linear range from 1 to 100μM(R^(2)=0.9979)and a low limit of detection(LOD)of 0.59μM for glutamate.These results suggest that the GLOX&HRP-HNFs is a promising candidate for applications in biosensing for the detection of glutamate.

Lingguizhugan Decoction, a Chinese herbal formula, improves insulin resistance in overweight/obese subjects with non-alcoholic fatty liver disease: a translational approach

Lingguizhugan Decoction(LGZG)has been investigated in basic studies,with satisfactory effects on insulin resistance in non-alcoholic fatty liver disease(NAFLD).This translational approach aimed to explore the effect and underlying mechanism of LGZG in clinical setting.A randomized,double-blinded,placebo-controlled trial was performed.A total of 243 eligible participants with NAFLD were equally allocated to receive LGZG(two groups:standard dose and low dose)or placebo for 12 weeks on the basis of lifestyle modifications.The primary efficacy variable was homeostasis model assessment of insulin resistance(HOMA-IR).Analyses were performed in two populations in accordance with body mass index(BMI;overweight/obese,BMI 24 kg/m^(2);lean,BMI<24 kg/m^(2)).For overweight/obese participants,low-dose LGZG significantly decreased their HOMA-IR level compared with placebo(0.19(1.47)versus 0.08(1.99),P=0.038).For lean subjects,neither dose of LGZG showed a superior effect compared with placebo.Methylated DNA immunoprecipitation sequencing and real-time qPCR found that the DNA N6-methyladenine modification levels of protein phosphatase 1 regulatory subunit 3A(PPP1R3A)and autophagy related 3(ATG3)significantly increased after LGZG intervention in overweight/obese population.Low-dose LGZG effectively improved insulin resistance in overweight/obese subjects with NAFLD.The underlying mechanism may be related to the regulation of DNA N6-methyladenine modification of PPP1R3A and ATG3.Lean subjects may not be a targeted population for LGZG.

Atom table convolutional neural networks for an accurate prediction of compounds properties

Machine learning techniques are widely used in materials science.However,most of the machine learning models require a lot of prior knowledge to manually construct feature vectors.Here,we develop an atom table convolutional neural networks that only requires the component information to directly learn the experimental properties from the features constructed by itself.For band gap and formation energy prediction,the accuracy of our model exceeds the standard DFT calculations.Besides,through dataenhanced technology,our model not only accurately predicts superconducting transition temperatures,but also distinguishes superconductors and non-superconductors.Utilizing the trained model,we have screened 20 compounds that are potential superconductors with high superconducting transition temperature from the existing database.In addition,from the learned features,we extract the properties of the elements and reproduce the chemical trends.This framework is valuable for high throughput screening and helpful to understand the underlying physics.

New Lignans from the Leaves and Stems of Schisandra chinensis and Their Anti-HIV-1 Activities

Six new lignans(1-6),as well as five known ones(7-11)were isolated from the leaves and stems of Schisandra chinensis.The structures of 1-6 were established on the basis of spectroscopic methods including 1D-and 2D-NMR techniques and CD experiments.Compound 1 was the first example of naturally occurring N-containing lignans featuring a nicotinoyl group.All the new compounds were evaluated for their anti-HIV-1 activities and showed EC50 values in the range 17.89-138.23μg/mL.

TBM penetration rate prediction based on the long short-term memory neural network

Tunnel boring machines(TBMs)are widely used in tunnel engineering because of their safety and efficiency.The TBM penetration rate(PR)is crucial,as its real-time prediction can reflect the adaptation of a TBM under current geological conditions and assist the adjustment of operating parameters.In this study,deep learning technology is applied to TBM performance prediction,and a PR prediction model based on a long short-term memory(LSTM)neuron network is proposed.To verify the performance of the proposed model,the machine parameters,rock mass parameters,and geological survey data from the water conveyance tunnel of the Hangzhou Second Water Source project were collected to form a dataset.Furthermore,2313 excavation cycles were randomly composed of training datasets to train the LSTM-based model,and 257 excavation cycles were used as a testing dataset to test the performance.The root mean square error and the mean absolute error of the proposed model are 4.733 and 3.204,respectively.Compared with Recurrent neuron network(RNN)based model and traditional time-series prediction model autoregressive integrated moving average with explanation variables(ARIMAX),the overall performance on proposed model is better.Moreover,in the rapidly increasing period of the PR,the error of the LSTM-based model prediction curve is significantly smaller than those of the other two models.The prediction results indicate that the LSTM-based model proposed herein is relatively accurate,thereby providing guidance for the excavation process of TBMs and offering practical application value.

Correlation of PCSK1 with nonalcoholic fatty liver disease in a Han Chinese population:a case-control observational study

Objective: This study aimed to investigate the association between single-nucleotide polymorphisms (SNPs) ofPCSK1 (proprotein convertase subtilisin/kexin type 1) related to obesity and nonalcoholic fatty liver disease (NAFLD).Methods: In this case-control observational study, four candidate SNPs (rs6234, rs155971, rs6232, rs3811951) ofPCSK1 were genotyped in 732 NAFLD patients and 823 healthy control participants, all of whom were of ethnic Han Chinese descent. All participants came from Shanghai, China, and joined our study during 2015 to 2016. The frequencies of each allele and genotype, paired linkage disequilibrium, and haplotype were calculated on the SHEsis platform. In addition to SHEsis, five different genetic models (codominant, dominant, recessive, overdominant, and log-additive) were employed to identify the correlation between genotype frequency and NAFLD. This study was approved by the Medical Ethics Committee of Shanghai University of Traditional Chinese Medicine (approved No. 2017LCSY069).Results: In a comparison of NAFLD patients and healthy participants, none of the fourPCSK1 SNPs were significantly correlated with the occurrence of NAFLD (P>0.05), in either genotypic or allelic distribution. The recessive model of rs3811951 appeared to show a correlation (odds ratio=1.077;95% confidence interval=0.924-1.256;P=0.04), but there was no statistical significance after Bonferroni correction (Pcorr>0.0125).Conclusions: Four obesity-relatedPCSK1 SNPs (rs6234, rs155971, rs6232, rs3811951) showed no significant correlation with the development of NAFLD in a Han Chinese population.