Tuning electronic structure of RuO_(2)by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium

The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.

Electron-deficient ZnO induced by heterointerface engineering as the dominant active component to boost CO_(2)-to-formate conversion

Electrocatalytic CO_(2)-to-formate conversion is considered an economically viable process.In general,Zn-based nanomaterials are well-known to be highly efficient electrocatalysts for the conversion of CO_(2) to CO,but seldom do they exhibit excellent selectivity toward formate.In this article,we demonstrate that a heterointerface catalyst ZnO/ZnSnO3 with nanosheet morphology shows enhanced selectivity with a maximum Faradaic efficiency(FE)of 86%at−0.9 V versus reversible hydrogen electrode and larger current density for the conversion of CO_(2) to formate than pristine ZnO and ZnSnO3.In particular,the FEs of the C1 products(CO+HCOO−)exceed 98%over the potential window.The experimental measurements combined with theoretical calculations revealed that the ZnO in ZnO/ZnSnO3 heterojunction delivers the valence electron depletion and accordingly optimizes Zn d-band center,which results in moderate Zn-O hybridization of HCOO*and weakened Zn-C hybridization of competing COOH*,thus greatly boosting the HCOOH generation.Our study highlights the importance of charge redistribution in catalysts on the selectivity of electrochemical CO_(2) reduction.

Sustained‑Release Nanocapsules Enable Long‑Lasting Stabilization of Li Anode for Practical Li‑Metal Batteries

A robust solid-electrolyte interphase(SEI)enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency.However,the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling.Herein,we demonstrate nanocapsules made from metal–organic frameworks for sustained release of LiNO3 as surface passivation additive in commercial carbonate-based electrolyte.The nanocapsules can offer over 10 times more LiNO3 than the solubility of LiNO3.Continuous supply of LiNO3 by nanocapsules forms a nitride-rich SEI layer on Li anode and persistently remedies SEI during prolonged cycling.As a result,lifespan of thin Li anode in 50μm,which experiences drastic volume change and repeated SEI formation during cycling,has been notably improved.By pairing with an industry-level thick LiCoO2 cathode,practical Li-metal full cell demonstrates a remarkable capacity retention of 90%after 240 cycles,in contrast to fast capacity drop after 60 cycles in LiNO3 saturated electrolyte.

Expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics

Objective： The high expression of cell division cycle 42 protein （CDC42） may be involved in the occurrence and progression of several tumors. However, the expression and function of CDC42 in cervical squamous cell carcinoma remains unclear. This study aimed to investigate the expression of CDC42 in cervical squamous cell carcinoma and its correlation with clinicopathologic characteristics. Methods： The expression of CDC42 in 162 cervical squamous cell carcinoma tissue samples and 33 normal cervical tissue samples was investigated by immunohistochemistry. The CDC42 mRNA expression was detected by reverse transcription-polymerase chain reaction （RT-PCR）. Results： The cervical squamous cell carcinoma group showed a significantly higher CDC42 positive rate, compared to the normal cervical tissues （P〈0.05）. Fttrthermore, the tissues of stage Ⅱ-Ⅳ carcinoma patients showed higher CDC42 expression levels compared to stage I patients （P=0.05）. In addition, the expression of CDC42 was not correlated to age of patients, differentiation degree of cancer cells, or lymph node metastasis （P〉0.05）. Furthermore, compare with normal cervical tissues, the CDC42 mRNA expression in cervical cancer had no significant difference. Conclusions： CDC42 was up-regulated at protein level, but not mRNA level, in cervical squamous cell carcinoma. The high expression of CDC42 was correlated to the clinical stage of the patients, indicating that CDC42 might contribute to the progression of cervical squamous cell carcinoma.

Quasi-solid electrolyte membranes with percolated metal–organic frameworks for practical lithium-metal batteries

High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.

Lysosome-targeted carbon dots with a light-controlled nitric oxide releasing property for enhanced photodynamic therapy

The reactive oxygen species(ROS) generation efficiency is always limited by the extreme tumor microenvironment(TME), leading to unsatisfactory antitumor effects in photodynamic therapy(PDT). As a promising gas therapy molecule, nitric oxide(NO) is independent of oxygen and could even synergize ROS to enhance the therapeutic effect. However, the short half-life, instability, and uncontrollable release of exogenous NO limited the application of tumor synergistic therapy. Herein, we reported a novel kind of red-emissive carbon dots(CDs) that was capable of lysosome-targeted and light-controlled NO delivery. The CDs were synthesized by using metformin and methylene blue(MB) via a hydrothermal method.The obtained metformin-MB CDs(MMCDs) exhibited a higher1O2quantum yield and NO generation efficiency under light emitting diode(LED) light irradiation. Noteworthily, the1O2could further in situ oxidize NO into peroxynitrite anions(ONOO-), which own the higher cytotoxicity against cancer cells.Cell experiments indicate that MMCDs could destruct lysosome membrane integrity and kill almost 80%of Hep G2 cells under light irradiation while very low cytotoxicity in the dark. Moreover, MMCDs significantly decreased tumor volume and weight after phototherapy in hepatoma Hep G2-bearing mice. Our study provides a new strategy for light-controlled NO generation as well as precise lysosome-targeting for enhancement of PDT efficiency.

Corpus Augmentation for Improving Neural Machine Translation

The translation quality of neural machine translation(NMT)systems depends largely on the quality of large-scale bilingual parallel corpora available.Research shows that under the condition of limited resources,the performance of NMT is greatly reduced,and a large amount of high-quality bilingual parallel data is needed to train a competitive translation model.However,not all languages have large-scale and high-quality bilingual corpus resources available.In these cases,improving the quality of the corpora has become the main focus to increase the accuracy of the NMT results.This paper proposes a new method to improve the quality of data by using data cleaning,data expansion,and other measures to expand the data at the word and sentence-level,thus improving the richness of the bilingual data.The long short-term memory(LSTM)language model is also used to ensure the smoothness of sentence construction in the process of sentence construction.At the same time,it uses a variety of processing methods to improve the quality of the bilingual data.Experiments using three standard test sets are conducted to validate the proposed method;the most advanced fairseq-transformer NMT system is used in the training.The results show that the proposed method has worked well on improving the translation results.Compared with the state-of-the-art methods,the BLEU value of our method is increased by 2.34 compared with that of the baseline.

去甲乌药碱:一种潜在的冠心病诊断心肌负荷药物

心肌灌注显像在冠心病的诊断、预后和管理中具有重要价值。当前,血管扩张剂和肾上腺素剂是最常见的心肌负荷药物。然而,这些药物在部分病人中的应用有限制,并且有多种副反应。因而,有必要开发可以在更多病人中应用的心肌负荷药物。去甲乌药碱是一种β受体激动剂,被批准作为心肌负荷药物应用于心肌缺血的诊断。因其正性肌力作用,去甲乌药碱有望成为用于冠心病诊断的心肌灌注显像负荷药物。本综述总结了去甲乌药碱在心肌灌注显像中的应用,包括其作用机制、给药方式、有效性及安全性。

Uncertainty Analysis Method of Casing Extrusion Load for Ultra-Deep Wells

With the consideration of the randomness of complex geologic parameters for ultra-deep wells,an uncertainty analysis method is presented for the extrusion load on casing in ultra-deep wells through complex formation at a certain confidence level.Based on the extrusion load model for casing in ultra-deep wells and the prerequisite of integrity of formation-cement ring-casing,the probability and statistics theory are introduced and the sensitivity analysis on the uncertainty of extrusion load on casing is conducted.The distribution types of each formation parameters are determined statistically.The distribution type and distribution function of the extrusion load on casing are derived.Then,the uncertainty analysis of the extrusion load on casing is carried out on several ultra-deep wells in Shanqian block as case study.Several conclusions are made regarding to the field trial result.The randomness of formation elasticity modulus and formation Poisson’s ratio are the main influence factors.The equivalent density profile of extrusion load on casing in ultra-deep wells is a confidence interval with a certain confidence level,rather than a single curve;the higher the confidence level is,the larger the bandwidth of the confidence interval of equivalent density profile becomes,and the larger the range of uncertainty interval becomes.Compared with the result of uncertainty analysis,an error exists in the result of traditional single valued calculation method.The error varies with different casing program and can be either positive or negative.The application of uncertainty analysis of extrusion load on casing provides proof for the accurate determination of casing collapse safety factor.Thus,the over engineering design or under engineering design as a result of tradition casing design will be avoided.

Oxygen-deficient SnO_(2)nanoparticles with ultrathin carbon shell for efficient electrocatalytic N_(2)reduction

For high-efficiency NH_(3)synthesis via ambient-condition electrohydrogenation of inert N_(2),it is pivotal to ingeniously design an active electrocatalyst with multiple features of abundant surfacial deficiency,good conductivity and large surface area.Here,oxygen-deficient SnO_(2)nanoparticles encapsulated by ultrathin carbon layer(d-SnO_(2)@C)are developed by hydrothermal deposition coupled with annealing process,as promising catalysts for ambient electrocatalytic N_(2)reduction.d-SnO_(2)@C exhibits high activity and excellent selectivity for electrocatalytic conversion of N_(2)to NH_(3)in acidic electrolytes,with Faradic efficiency as high as 12.7%at-0.15 V versus the reversible hydrogen electrode(RHE)and large NH_(3)yield rate of 16.68μg h^(-1)mgcat^(-1)at-0.25 V vs.RHE in 0.1 mol L^(-1)HCl.Benefiting from the structural superiority of enhanced charge transfer efficiency and optimized surface states,d-SnO_(2)@C also achieves excellent long-term stability.

Microcapsule-enabled self-healing concrete:A bibliometric analysis

With the development of self-healing technology, the overall properties of the microcapsule-enabled selfhealingconcrete have taken a giant leap. In this research, a detailed assessment of current research on the microcapsuleenabledself-healing concrete is conducted, together with bibliometric analysis. In the bibliometric analysis, variousindicators are considered. The current state of progress regarding self-healing concrete is assessed, and an analysis of thetemporal distribution of documents, organizations and countries of literature is conducted. Later, a discussion of thecitations is analyzed. The research summarizes the improvements of microcapsule-enabled self-healing cementitiouscomposites and provides a concise background overview.

Bile acids and coronavirus disease 2019

The coronavirus disease 2019(COVID-19)pandemic,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has been significantly alleviated.However,long-term health effects and prevention strategy remain unresolved.Thus,it is essential to explore the pathophysiological mechanisms and intervention for SARS-CoV-2 infection.Emerging research indicates a link between COVID-19 and bile acids,traditionally known for facilitating dietary fat absorption.The bile acid ursodeoxycholic acid potentially protects against SARS-CoV-2 infection by inhibiting the farnesoid X receptor,a bile acid nuclear receptor.The activation of G-protein-coupled bile acid receptor,another membrane receptor for bile acids,has also been found to regulate the expression of angiotensin-converting enzyme 2,the receptor through which the virus enters human cells.Here,we review the latest basic and clinical evidence linking bile acids to SARS-CoV-2,and reveal their complicated pathophysiological mechanisms.

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed.Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.

Pathological matrix stiffness promotes cardiac fibroblast differentiation through the POU2F1 signaling pathway

Cardiac fibroblast(CF)differentiation into myofibroblasts is a crucial cause of cardiac fibrosis,which increases in the extracellular matrix(ECM)stiffness.The increased stiffness further promotes CF differentiation and fibrosis.However,the molecular mechanism is still unclear.We used bioinformatics analysis to find new candidates that regulate the genes involved in stiffnessinduced CF differentiation,and found that there were binding sites for the POU-domain transcription factor,POU2F1(also known as Oct-1),in the promoters of 50 differentially expressed genes(DEGs)in CFs on the stiffer substrate.Immunofluorescent staining and Western blotting revealed that pathological stiffness upregulated POU2F1 expression and increased CF differentiation on polyacrylamide hydrogel substrates and in mouse myocardial infarction tissue.A chromatin immunoprecipitation assay showed that POU2F1 bound to the promoters of fibrosis repressors IL1R2,CD69,and TGIF2.The expression of these fibrosis repressors was inhibited on pathological substrate stiffness.Knockdown of POU2F1 upregulated these repressors and attenuated CF differentiation on pathological substrate stiffness(35 kPa).Whereas,overexpression of POU2F1 downregulated these repressors and enhanced CF differentiation.In conclusion,pathological stiffness upregulates the transcription factor POU2F1 to promote CF differentiation by inhibiting fibrosis repressors.Our work elucidated the crosstalk between CF differentiation and the ECM and provided a potential target for cardiac fibrosis treatment.

A novel β_(2)-AR agonist,Higenamine,induces β-arrestin-biased signaling

The biased ligands in G protein-coupled receptors(GPCRs)have opened new avenues for developing safer and more effective drugs.However,the identification of such biased ligands as drug candidates is highly desirable.Here,we report that Higenamine,a compound isolated from a Chinese herb,functions as a novel β-arrestin-biased ligand of the β_(2)-adrenergic receptor(β_(2)-AR).The radioligand binding assays demonstrated that Higenamine was the ligand of β_(2)-AR.Higenamine induced phosphorylation of extracellular signal-regulated kinase 1/2(ERK1/2),which can be blocked by propranolol,an inhibitor of β_(2)-AR.The Gi protein inhibitor,pertussis toxin,had no effect on the phosphorylation of ERK1/2 induced by Higenamine.Furthermore,Higenamine induced ERK1/2 phosphorylation through transactivation of Epithelial growth factor receptor(EGFR).We also found that Higenamine-induced-ERK1/2 phosphorylation is dependent on β-arrestin1/2,and HG inhibits Doxorubicin-induced cardiomyocyte apoptosis.Our results identify Higenamine as a novel biased ligand via the β-arrestin-dependent pathway.These findings give us a better understanding of Higenamine’s potential role in designing diagnostic and therapeutic strategies.

Enriching the library of axial superlattice nanowires

Integrating functional materials to form heterostructures with novel,sophisticated architectures has attracted extensive interest in chemistry and materials science^([1]).Heterostructures are expected to exhibit superior electrical,thermal,optical and magnetic properties due to the synergistic effect of their different components.Therefore,the rational design and preparation of heterostructures with controlled compositions,dimensions.

晶格应变和异质界面工程协同促进铋基催化剂高效电催化CO_(2)还原生成甲酸

表面应力耦合异质结构是一种改善非均相催化剂催化性能的有效策略.它可以在调控催化剂电子结构的同时,促进电荷传输.一般来说,Bi基催化剂对CO_(2)电还原为甲酸的选择性高于ZnO,但是金属Bi的价格高于Zn.本文以十六烷基三甲基溴化铵为模板剂,通过一步水热法合成了一种具有多孔纳米片形貌的Bi_(2)O_(2)CO_(3)/ZnO异质结催化剂,用于高效电催化CO_(2)还原制备甲酸.在-1.0 V vs.RHE下,该催化剂展现出最大甲酸盐法拉第效率(92%),且在施加-1.2 V vs.RHE电压下甲酸盐偏电流密度为200 m A mg_(Bi)^(-1).更重要的是,对Bi的质量进行归一化发现,Bi_(2)O_(2)CO_(3)/ZnO的质量活度比纯Bi_(2)O_(2)CO_(3)的质量活度提升了3.1倍.通过X-射线光电子能谱和X-射线吸收谱测试表明,在该催化剂中,界面Zn原子电荷向Bi原子转移,形成了富电子的Bi_(2)O_(2)CO_(3)表面,有利于CO_(2)的捕获和活化;而异质结构引起的压缩应力有利于优化反应中间体的吸附能,二者协同提高了Bi_(2)O_(2)CO_(3)/ZnO电催化CO_(2)还原生成甲酸的选择性和活性.

Supramolecular Surface Engineering of Carbon Dots Enables Matrix-Free Room Temperature Phosphorescence

Comprehensive Summary,Carbon dots(CDs)are an emerging class of nanomaterials with intriguing photophysical properties.Recently,achieving room temperature phosphorescence(RTP)for CDs has attracted considerable attention for biomedical and information applications.However,the CDs based RTP materials generally require the use of polymeric and inorganic matrix to provide the rigid environments,which remains a great challenge to obtain matrix-free CDs with RTP.Herein,a novel supramolecular strategy based on strong interparticle interactions has been developed to attain this objective,by covalent decoration of ureido-pyrimidinone(UPy,a multiple hydrogen bonding unit)on the surface of CDs.Structural characterizations validated the core-shell structure of the as-prepared CDs(EDTA-CDs)and demonstrated the successful attachment of UPy via post-modification(UPy-CDs).The presence of UPy recognition units render the strong hydrogen bonding between UPy-CDs,which stabilizes the triplet state via rigidifying effect.As a result,UPy-CDs exhibit matrix-free efficient RTP(λ_(em)=534 nm)with high brightness and long lifetime(33.6 ms)in the solid state.Owing to the dual-emission character,we further explored the application potential of UPy-CDs in information encryption and anti-counterfeiting.Overall,this work provides a new and facile strategy for achieving matrix-free phosphorescent CDs with elegant incorporation of supramolecular chemistry.

Insight-HXMT observations of the first binary neutron star merger GW170817

Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event.

Angiotensin-converting enzyme 2(ACE2):SARS-CoV-2 receptor and RAS modulator

The coronavirus disease 2019(COVID-19)outbreak is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Angiotensin-converting enzyme 2(ACE2)was rapidly identified as the critical functional receptor for SARS-CoV-2.ACE2 is well-known as a counter-regulator of the renin-angiotensin system(RAS)and plays a key role in the cardiovascular system.Given that ACE2 functions as both a SARS-CoV-2 receptor and a RAS modulator,the treatment for COVID-19 presents a dilemma of how to limit virus entry but protect ACE2 physiological functions.Thus,an in-depth summary of the recent progress of ACE2 research and its relationship to the virus is urgently needed to provide possible solution to the dilemma.Here,we summarize the complexity and interplay between the coronavirus,ACE2 and RAS(including anti-RAS drugs).We propose five novel working modes for functional receptor for SARS-CoV-2 infection and the routes of ACE2-mediated virus entering host cells,as well as its regulatory mechanism.For the controversy of anti-RAS drugs application,we also give theoretical analysis and discussed for drug application.These will contribute to a deeper understanding of the complex mechanisms of underlying the relationship between the virus and ACE2,and provide guidance for virus intervention strategies.