A number of recent studies have demonstrated that electrochemical technologies, including electroreduction （ER）, electrocoagulation （EC）, and electrodialysis （ED）, are effbctive in nitrate elimination in wastewa...A number of recent studies have demonstrated that electrochemical technologies, including electroreduction （ER）, electrocoagulation （EC）, and electrodialysis （ED）, are effbctive in nitrate elimination in wastewater due to their high reactivity. To obtain the maximal elimination efficiency and current efficiency, many researchers have conducted experiments to investigate the optimal conditions （i.e., potential, cun＇ent density, pH value, plate distance, initial nitrate concentration, electrolyte, and other factors） tbr nitrate elimination. The mechanism of ER, EC and ED for nitrate removal has been fully elucidated. The ER mechanism of nitrate undergoes electron transfer and hydrogenation reduction. The EC pathways of nitrate removal include reduction, coagulation and flotation. The ED pathways of nitrate include redox reaction and dialysis. Although the electrochemical technology can remove nitrate from wastewater efficiently, many problems （such as relatively low selectivity toward nitrogen, sludge production and brine generation） still hinder electrochemical treatment implementa- tion. This paper critically presents an overview of the current state-of-the-art of electrochemical denitrification to enhance the removal efficiency and overcome the shortages, and will significantly improve the understanding of the detailed processes and mechanisms of nitrate removal by electrochemical treatment and provide useful information to scientific research and actual practice.展开更多
Upset errors in 90-nm 64 Mb NOR-type floating-gate Flash memory induced by accelerated ^（129）Xe and ^（209）Bi ions are investigated in detail. The linear energy transfer covers the range from 50 to 99.8 Me V/（mg/c...Upset errors in 90-nm 64 Mb NOR-type floating-gate Flash memory induced by accelerated ^（129）Xe and ^（209）Bi ions are investigated in detail. The linear energy transfer covers the range from 50 to 99.8 Me V/（mg/cm^2）. When the memory chips are powered off during heavy ions irradiation, single-event-latch-up and single-event-function-interruption are excluded,and only 0-〉1 upset errors in the memory array are observed. These error bit rates seem very difficult to achieve and cannot be simply recovered based on the power cycle. The number of error bits shows a strong dependence on the linear energy transfer（LET）. Under room-temperature annealing conditions, the upset errors can be reduced by about two orders of magnitude using rewrite/reprogram operations, but they subsequently increase once again in a few minutes after the power cycle. High-temperature annealing can diminish almost all error bits, which are affected by the lower LET ^（129）Xe ions. The percolation path between the floating-gate（FG） and the substrate contributes to the radiation-induced leakage current, and has been identified as the root cause of the upset errors of the Flash memory array in this work.展开更多
The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respect...The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respectively. After 100 cycles between 3.0 V-4.6 V, 0.1 wt% W doping provides an optimized capacity retention of 72.3%. However, W coating deteriorates battery performance with capacity retention of 47.8%, even lower than bare LiCoO2 of 55.7%. These different electrochemical performances can be attributed to the surface aggregation of W between doping and coating methods. W substitution is proved to be a promising method to develop high voltage cathodes. Practical performance relies on detailed synthesis method.展开更多
Few studies investigated the effects of exposure to NO_(2) on health status in the Chinese floating population.The present cross-sectional study evaluated the association of ambient NO_(2) with health status in a floa...Few studies investigated the effects of exposure to NO_(2) on health status in the Chinese floating population.The present cross-sectional study evaluated the association of ambient NO_(2) with health status in a floating population in China.Data on 168961 floating individuals in 338 cities were obtained from the 2017 China Migrants Dynamic Survey.The association between exposure to NO_(2) and self-related health(SRH)status was assessed by binary logistic regression analysis,both in the entire subject cohort and in subgroups assorted by socioeconomic levels and demographic characteristics.The robustness of the associations between NO_(2) exposure and health status was evaluated by sensitivity analyses.Each grade increment of annual average NO_(2) exposure was found to increase the risk of poor SRH by 2.4%in the floating population(odds ratio[OR]=1.024,95%confidence interval[CI]:1.011-1.038).When subgrouped by age,subjects in the floating population aged 31-49 years had the highest NO_(2) associated health risk(OR=1.036,95%CI:1.018-1.054).When subgrouped by per capita gross domestic product(PGDP),subjects in regions with mid-level PDGP had the highest NO_(2) associated SRH(OR=1.116,95%CI:1.091-1.i41).These findings indicated that exposure to NO_(2) increases the risk of poor SRH in the floating population,with individuals aged 31-49 years and those living in mid-level PGDP regions being more sensitive to the adverse effects of NO_(2).More effective strategies to reduce air pollution may improve the health status of the floatingpopulation in China.展开更多
Achieving color-tunable emission in single-component organic emitters with multistage stimuli-responsiveness is of vital significance for intelligent optoelectronic applications,but remains enormously challenging.Here...Achieving color-tunable emission in single-component organic emitters with multistage stimuli-responsiveness is of vital significance for intelligent optoelectronic applications,but remains enormously challenging.Herein,we present an unprecedented example of a color-tunable single-component smart organic emitter(DDOP)that simultaneously exhibits multistage stimuli-responsiveness and multimode emissions.DDOP based on a highly twisted amide-bridged donor-tcceptor-donor structure has been found to facilitate intersystem crossing,form multimode emissions,and generate multiple emissive species with multistage stimuli-responsiveness.DDOP pristine crystalline powders exhibit abnormal excitation-dependent emissions from a monomer-dominated blue emission centered at 470 nm to a dimer-dominated yellow emission centered at 550 nm through decreasing the ultraviolet(UV)excitation wavelengths,whereas DDOP single crystals show a wide emission band with a main emission peak at 585 nm when excited at different wavelengths.The emission behaviors of pristine crystalline powders and single crystals are different,demonstrating emission features that are closely related to the aggregation states.The work has developed color-tunable single-component organic emitters with simultaneous multistage stimuli-responsiveness and multimode emissions,which is vital for expanding intelligent optoelectronic applications,including multilevel information encryption,multicolor emissive patterns,and visual monitoring of UV wavelengths.展开更多
Phospholipids hold a multifaceted function in cellular biology.The primary function of phospholipids is to serve as essential building blocks of cell membranes,which gives cells crucial structural support and facilita...Phospholipids hold a multifaceted function in cellular biology.The primary function of phospholipids is to serve as essential building blocks of cell membranes,which gives cells crucial structural support and facilitates cellular organization.Beyond that,phospholipids also act as key signaling molecules that coordinate vital cellular processes such as organismal development,homeostasis,and adaptation to environmental changes.Despite being the smallest and simplest phospholipid,phosphatidic acid(PA)plays a crucial role as a metabolic intermediate and second messenger.展开更多
Surface plasmon polaritons（SPPs） are evanescent waves propagating along metal-dielectric interfaces, which provide an effective way to realize optical wave guiding with subwavelength confinement. Metallic nanostruct...Surface plasmon polaritons（SPPs） are evanescent waves propagating along metal-dielectric interfaces, which provide an effective way to realize optical wave guiding with subwavelength confinement. Metallic nanostructures supporting SPPs,that is, plasmonic waveguides, are considered as required components to construct nanophotonic devices and circuits with a high degree of miniaturization and integration. In this paper, various types of plasmonic waveguides operating in the visible, infrared, and terahertz regions are reviewed, and the status of the research on their fundamentals, fabrications,and applications is provided as well. First, we discuss the mechanisms of SPPs beyond the diffraction limit, and their launching methods. Then, the characteristics of SPPs on various plasmonic waveguides are reviewed, including top-down and bottom-up fabricated types. Considering applications, certain prototypes of plasmonic devices and circuits constructed by plasmonic waveguides for bio/chemo sensing, router, and light modulation are demonstrated. Finally, a summary and future outlook of plasmonic waveguides are given.展开更多
BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whe...BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct 展开更多
Background： The recently emerged technology of methylated RNA immunoprecipitation sequencing （MeRIP-seq） sheds light on the study of RNA epigenetics. This new bioinformatics question calls for effective and robust ...Background： The recently emerged technology of methylated RNA immunoprecipitation sequencing （MeRIP-seq） sheds light on the study of RNA epigenetics. This new bioinformatics question calls for effective and robust peaking calling algorithms to detect mRNA methylation sites from MeRIP-seq data. Methods： We propose a Bayesian hierarchical model to detect methylation sites from MeRIP-seq data. Our modeling approach includes several important characteristics. First, it models the zero-inflated and over-dispersed counts by deploying a zero-inflated negative binomial model. Second, it incorporates a hidden Markov model （HMM） to account for the spatial dependency of neighboring read enrichment. Third, our Bayesian inference allows the proposed model to borrow strength in parameter estimation, which greatly improves the model stability when dealing with MeRIP-seq data with a small number of replicates. We use Markov chain Monte Carlo （MCMC） algorithms to simultaneously infer the model parameters in a de novo fashion. The R Shiny demo is available at https：//qiwei. shinyapps.io/BaySeqPeak and the R/C ＋＋ code is available at https：//github.com/liqiwei2000/BaySeqPeak. Results： In simulation studies, the proposed method outperformed the competing methods exomePeak and MeTPeak, especially when an excess of zeros were present in the data. In real MeRIP-seq data analysis, the proposed method identified methylation sites that were more consistent with biological knowledge, and had better spatial resolution compared to the other methods. Conclusions： In this study, we develop a Bayesian hierarchical model to identify methylation peaks in MeRIP-seq data. The proposed method has a competitive edge over existing methods in terms of accuracy, robustness and spatial resolution.展开更多
Doping and blending strategies are crucial means to precisely control the excited states and energy level in conjugated molecular systems.However,effective models and platforms are rarely proposed to systematically ex...Doping and blending strategies are crucial means to precisely control the excited states and energy level in conjugated molecular systems.However,effective models and platforms are rarely proposed to systematically explore the effects of the formation of trapped doped centers on heterogeneous structures,energy level and ultrafast photophysical process.Herein,for deeply understanding the impact of molecular doping in film energy levels and photoexcitation dynamics,we set a supramolecular N-B coordination composed by the conjugated molecules of pyridine functionalized diarylfluorene(host material),named as ODPF-Phpy and ODPF-(Phpy)2,and the molecule of tris(perfluorophenyl)borane(BCF)(guest material).The generation of the molecular-level coordination bond increased the binding energy of N atoms and tuned the band-gap,leading to a new fluorescent emission center with longer excitation wavelength and emission wavelength.The intermolecular Forster resonance energy transfer(FRET)in blending flms make it present inconsistent fluorescent behaviors compared to that in solution.The charge transfer(CT)state of N-B coordinated compounds and the changed dielectric constant of blending films resulted in a large PL spectra red-shift with the increased dopant ratio,causing a wide-tunable fluorescent color.The excited state behaviors of two compounds in blending system was further investigated by the transient absorption(TA)spectroscopy.Finally,we found supramolecular coordination blending can effectively improve the films'photoluminescence quantum yield(PLQY)and conductivity.We believe this exploration in the internal coordination mechanisms would deepen the insights about doped semiconductors and is helpful in developing novel high-efficient fluorescent systems.展开更多
Postprostatectomy erectile dysfunction(pPED)remains a current problem despite improvements in surgical techniques.Vacuum therapy is clinically confirmed as a type of pPED rehabilitation.However,its underlying mechanis...Postprostatectomy erectile dysfunction(pPED)remains a current problem despite improvements in surgical techniques.Vacuum therapy is clinically confirmed as a type of pPED rehabilitation.However,its underlying mechanisms are incompletely understood.Recently,autophagy and apoptosis were extensively studied in erectile dysfunction resulting from diabetes,senescence,and androgen deprivation but not in the context of pPED and vacuum therapy.Therefore,this study was designed to investigate the roles of autophagy and apoptosis in pPED and vacuum therapy.Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups:the control group,bilateral cavernous nerve crush(BCNC)group,and BCNC+vacuum group.After 4 weeks of treatment,intracavernosal pressure was used to evaluate erectile function.Real-time quantitative polymerase chain reaction,western blot,and immunohistochemistry were used to measure the molecular expression.TdT-mediated dUTP nick-end labeling staining was used to assess apoptosis.Transmission electron microscopy was used to observe autophagosomes.After treatment,compared with those of the BCNC group,erectile function and cavernosal hypoxia had statistically significantly improved(P<0.05).Apoptosis and the relative protein expression of B-cell lymphoma-2-associated X and cleaved Caspase3 were decreased(P<0.05).Autophagy-related molecules such as phosphorylated unc-51-like autophagy-activating kinase 1(Ser757)and p62 were decreased.Beclinl,microtubule-associated protein 1 light chain 3 A/B,and autophagosomes were increased(P<0.05).Besides,the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway,as a negative regulator of autophagy to some degree,was inhibited.This study revealed that vacuum therapy ameliorated pPED in BCNC rats by inhibiting apoptosis and activating autophagy.展开更多
Mesoporous Au films consisting of a network of interconnected Au ligaments around ultra-large pores were found to exhibit a promising electrocatalytic activity towards sluggish reactions. Mesoporous Au films with pore...Mesoporous Au films consisting of a network of interconnected Au ligaments around ultra-large pores were found to exhibit a promising electrocatalytic activity towards sluggish reactions. Mesoporous Au films with pore sizes up to 25 nm were successfully fabricated using a polymeric micelle approach. A superior catalytic activity of the mesoporous Au films towards methanol oxidation was confirmed, which was thoroughly analyzed and compared with that of other Au materials. An intrinsic investigation on the high catalytic activity revealed that the superior performance of the as-prepared mesoporous Au film was related to its unique atomic structures around the mesopores with well- crystallized facets and several step/kink sites on the Au surfaces. These findings showcase a strategic and feasible design for preparing highly active Au-based catalysts that could be used as promising candidates in electrocatalytic applications.展开更多
Suicide is the second leading cause of death in youth globally; however, there is uncertainty about how best to intervene. Suicide rates are typically higher in males than females, while the converse is true for suici...Suicide is the second leading cause of death in youth globally; however, there is uncertainty about how best to intervene. Suicide rates are typically higher in males than females, while the converse is true for suicide attempts. We review this "gender paradox" in youth, and in particular, the age-dependency of these sex/gender differences and the developmental mechanisms that may explain them. Epidemiologic, genetic,neurodevelopmental and psychopathological research have identified suicidal behaviour risks arising from genetic vulnerabilities and sex/gender differences in early adverse environments, neurodevelopment, mental disorder and their complex interconnections. Further, evolving sex-/gender-defined social expectations and norms have been thought to influence suicide risk. In particular, how youth perceive and cope with threats and losses(including conforming to others' or one's own expectations of sex/gender identity) and adapt to pain(through substance use and helpseeking behaviours). Taken together, considering brain plasticity over the lifespan, these proposed antecedents to youth suicide highlight the importance of interventions that alter early environment(s)(e.g., childhood maltreatment) and/or one's ability to adapt to them. Further, such interventions may have more enduring protective effects, for the individual and for future generations, if implemented in youth.展开更多
The phenomenon of phase separation into antiferromagnetic（AFM） and superconducting（SC） or normal-state regions has great implication for the origin of high-temperature（high-T_c） superconductivity. However, the o...The phenomenon of phase separation into antiferromagnetic（AFM） and superconducting（SC） or normal-state regions has great implication for the origin of high-temperature（high-T_c） superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the T_c of（Li,Fe）OHFe Se superconductor is questioned. Here we report a systematic study on a series of（Li,Fe）OHFe Se single crystal samples with T_c up to ～41 K. We observe an evident drop in the static magnetization at T_（afm） ～ 125 K, in some of the SC（T_c 38 K, cell parameter c■9.27 ？） and non-SC samples. We verify that this AFM signal is intrinsic to（Li,Fe）OHFe Se. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal（below T_（afm）） or SC（below T_c） state in（Li,Fe）OHFe Se. We explain such coexistence by electronic phase separation, similar to that in high-T_c cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of（Li,Fe）OHFe Se, particularly it is never observed in the SC samples of T_c 38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. The occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as T_（afm）, reported previously for a（Li,Fe）OHFe Se（T_c ～ 42 K） single crystal, suggests that the microscopic static phase separation reaches vanishing point in high T_c（Li,Fe）OHFe Se. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-T_c superconductivity.展开更多
The microstructure and stress rupture properties of Inconel 706 alloy microalloyed with phosphorus are examined under stabilizing and unstabilizing heat treatment conditions.It was found that applying the stabilizing ...The microstructure and stress rupture properties of Inconel 706 alloy microalloyed with phosphorus are examined under stabilizing and unstabilizing heat treatment conditions.It was found that applying the stabilizing treatment resulted in a 98% increment in the stress rupture life and a 215% increment in the elongation tested at 650℃/690 MPa for the alloy compared to that under the unstabilizing heat treatment condition.The stabilizing treatment led to the precipitation of rod-shaped and needle-shaped n phases at the grain boundaries.Morphologies of γ'-γ" co-precipitates in the grain interior were noncompact form and compact form for the alloy under unstabilizing and stabilizing heat treatment conditions,respectively.Based on the microstructure characterizations,the improvement of stress rupture properties by the stabilizing treatment was attributed to the precipitation of n phases at the grain boundaries,which can hinder cracks initiation and propagation and relieve the stress concentration.展开更多
The conventional magnetic resonance imaging(MRI)equipment cannot measure large volume samples nondestructively in the engineering site for its heavy weight and closed structure.In order to realize the mobile MRI,this ...The conventional magnetic resonance imaging(MRI)equipment cannot measure large volume samples nondestructively in the engineering site for its heavy weight and closed structure.In order to realize the mobile MRI,this study focuses on the design of gradient coil of unilateral magnet.The unilateral MRI system is used to image the local area above the magnet.The current density distribution of the gradient coil cannot be used as a series of superconducting nuclear magnetic resonance gradient coils,because the region of interest(ROI)and the wiring area of the unilateral magnet are both cylindrical side arc surfaces.Therefore,the equivalent magnetic dipole method is used to design the gradient coil,and the algorithm is improved for the special case of the wiring area and the ROI,so the X and Y gradient coils are designed.Finally,a flexible printed circuit board(PCB)is used to fabricate the gradient coil,and the magnetic field distribution of the ROI is measured by a Gauss meter,and the measured results match with the simulation results.The gradient linearities of x and y coils are 2.82%and 3.56%,respectively,less than 5%of the commercial gradient coil requirement.展开更多
A variety of factors have been identified as being risk factors for suicidal behaviour. One of them is the handling of stressful events. The aim of the present study was to investigate the coping-strategies used by su...A variety of factors have been identified as being risk factors for suicidal behaviour. One of them is the handling of stressful events. The aim of the present study was to investigate the coping-strategies used by suicide attempters and comparison groups. 37 patients who had recently made a suicide attempt, 38 suicide attempters at follow up, 20 psychiatric follow up controls, and 19 healthy controls filled in the COPE. We found that suicide attempters at long term follow up and healthy controls used more adaptive problem solving strategies than patients who had recently made a suicide attempt, or psychiatric controls at follow up, who used more maladaptive coping strategies. Our findings suggest that suicide attempters in a twelve year follow up are able to use coping strategies similarly to healthy controls by e.g. approaching the stressor actively. Further examinations of the impact of long term professional care and treatment of suicide attempters on their coping strategies are necessary.展开更多
文摘A number of recent studies have demonstrated that electrochemical technologies, including electroreduction （ER）, electrocoagulation （EC）, and electrodialysis （ED）, are effbctive in nitrate elimination in wastewater due to their high reactivity. To obtain the maximal elimination efficiency and current efficiency, many researchers have conducted experiments to investigate the optimal conditions （i.e., potential, cun＇ent density, pH value, plate distance, initial nitrate concentration, electrolyte, and other factors） tbr nitrate elimination. The mechanism of ER, EC and ED for nitrate removal has been fully elucidated. The ER mechanism of nitrate undergoes electron transfer and hydrogenation reduction. The EC pathways of nitrate removal include reduction, coagulation and flotation. The ED pathways of nitrate include redox reaction and dialysis. Although the electrochemical technology can remove nitrate from wastewater efficiently, many problems （such as relatively low selectivity toward nitrogen, sludge production and brine generation） still hinder electrochemical treatment implementa- tion. This paper critically presents an overview of the current state-of-the-art of electrochemical denitrification to enhance the removal efficiency and overcome the shortages, and will significantly improve the understanding of the detailed processes and mechanisms of nitrate removal by electrochemical treatment and provide useful information to scientific research and actual practice.
基金Project supported by the National Natural Science Foundation of China(Grant No.616340084)the Youth Innovation Promotion Association of CAS(Grant No.2014101)+1 种基金the International Cooperation Project of CASthe Austrian-Chinese Cooperative R&D Projects(Grant No.172511KYSB20150006)
文摘Upset errors in 90-nm 64 Mb NOR-type floating-gate Flash memory induced by accelerated ^（129）Xe and ^（209）Bi ions are investigated in detail. The linear energy transfer covers the range from 50 to 99.8 Me V/（mg/cm^2）. When the memory chips are powered off during heavy ions irradiation, single-event-latch-up and single-event-function-interruption are excluded,and only 0-〉1 upset errors in the memory array are observed. These error bit rates seem very difficult to achieve and cannot be simply recovered based on the power cycle. The number of error bits shows a strong dependence on the linear energy transfer（LET）. Under room-temperature annealing conditions, the upset errors can be reduced by about two orders of magnitude using rewrite/reprogram operations, but they subsequently increase once again in a few minutes after the power cycle. High-temperature annealing can diminish almost all error bits, which are affected by the lower LET ^（129）Xe ions. The percolation path between the floating-gate（FG） and the substrate contributes to the radiation-induced leakage current, and has been identified as the root cause of the upset errors of the Flash memory array in this work.
基金Project supported by the National Key Rerearch and Development Program of China(Grant No.2017YFB0102004)the National Natural Science Foundation of China(Grant No.51502334)+1 种基金the Fund from Beijing Municipal Science&Technology Commission,China(Grant No.D171100005517001)the Thousand Talent Program for Outstanding Young Scientists,China
文摘The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respectively. After 100 cycles between 3.0 V-4.6 V, 0.1 wt% W doping provides an optimized capacity retention of 72.3%. However, W coating deteriorates battery performance with capacity retention of 47.8%, even lower than bare LiCoO2 of 55.7%. These different electrochemical performances can be attributed to the surface aggregation of W between doping and coating methods. W substitution is proved to be a promising method to develop high voltage cathodes. Practical performance relies on detailed synthesis method.
基金supported by the National Natural Science Foundation of China(No.72374033)the Social Science Planning Research Project of Shandong Province(China)(No.22CRKJ01).
文摘Few studies investigated the effects of exposure to NO_(2) on health status in the Chinese floating population.The present cross-sectional study evaluated the association of ambient NO_(2) with health status in a floating population in China.Data on 168961 floating individuals in 338 cities were obtained from the 2017 China Migrants Dynamic Survey.The association between exposure to NO_(2) and self-related health(SRH)status was assessed by binary logistic regression analysis,both in the entire subject cohort and in subgroups assorted by socioeconomic levels and demographic characteristics.The robustness of the associations between NO_(2) exposure and health status was evaluated by sensitivity analyses.Each grade increment of annual average NO_(2) exposure was found to increase the risk of poor SRH by 2.4%in the floating population(odds ratio[OR]=1.024,95%confidence interval[CI]:1.011-1.038).When subgrouped by age,subjects in the floating population aged 31-49 years had the highest NO_(2) associated health risk(OR=1.036,95%CI:1.018-1.054).When subgrouped by per capita gross domestic product(PGDP),subjects in regions with mid-level PDGP had the highest NO_(2) associated SRH(OR=1.116,95%CI:1.091-1.i41).These findings indicated that exposure to NO_(2) increases the risk of poor SRH in the floating population,with individuals aged 31-49 years and those living in mid-level PGDP regions being more sensitive to the adverse effects of NO_(2).More effective strategies to reduce air pollution may improve the health status of the floatingpopulation in China.
基金support from the National Natural Science Foundation of China(21835003 and 62274097)the Natural Science Foundation of Jiangsu Province(BE2019120)+2 种基金the Program for Jiangsu Specially-Appointed Professor(RK030STP15001)the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of Chinathe Postgraduate Research and Practice Innovation Program of Jiangsu Province(KYCX18_0859).
文摘Achieving color-tunable emission in single-component organic emitters with multistage stimuli-responsiveness is of vital significance for intelligent optoelectronic applications,but remains enormously challenging.Herein,we present an unprecedented example of a color-tunable single-component smart organic emitter(DDOP)that simultaneously exhibits multistage stimuli-responsiveness and multimode emissions.DDOP based on a highly twisted amide-bridged donor-tcceptor-donor structure has been found to facilitate intersystem crossing,form multimode emissions,and generate multiple emissive species with multistage stimuli-responsiveness.DDOP pristine crystalline powders exhibit abnormal excitation-dependent emissions from a monomer-dominated blue emission centered at 470 nm to a dimer-dominated yellow emission centered at 550 nm through decreasing the ultraviolet(UV)excitation wavelengths,whereas DDOP single crystals show a wide emission band with a main emission peak at 585 nm when excited at different wavelengths.The emission behaviors of pristine crystalline powders and single crystals are different,demonstrating emission features that are closely related to the aggregation states.The work has developed color-tunable single-component organic emitters with simultaneous multistage stimuli-responsiveness and multimode emissions,which is vital for expanding intelligent optoelectronic applications,including multilevel information encryption,multicolor emissive patterns,and visual monitoring of UV wavelengths.
基金supported by a grant from the National Science Foundation(IOS-2207677)to Z.Q.F,。
文摘Phospholipids hold a multifaceted function in cellular biology.The primary function of phospholipids is to serve as essential building blocks of cell membranes,which gives cells crucial structural support and facilitates cellular organization.Beyond that,phospholipids also act as key signaling molecules that coordinate vital cellular processes such as organismal development,homeostasis,and adaptation to environmental changes.Despite being the smallest and simplest phospholipid,phosphatidic acid(PA)plays a crucial role as a metabolic intermediate and second messenger.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704266 and 11774245)the Fok Ying Tung Education Foundation,China(Grant No.151010)+2 种基金the Scientific Research Base Development Program of Beijing Municipal Commission of Education,Chinathe General Foundation of Beijing Municipal Commission of Education,China(Grant No.KM201810028006)the Training Program of the Major Research Plan of Capital Normal University,China
文摘Surface plasmon polaritons（SPPs） are evanescent waves propagating along metal-dielectric interfaces, which provide an effective way to realize optical wave guiding with subwavelength confinement. Metallic nanostructures supporting SPPs,that is, plasmonic waveguides, are considered as required components to construct nanophotonic devices and circuits with a high degree of miniaturization and integration. In this paper, various types of plasmonic waveguides operating in the visible, infrared, and terahertz regions are reviewed, and the status of the research on their fundamentals, fabrications,and applications is provided as well. First, we discuss the mechanisms of SPPs beyond the diffraction limit, and their launching methods. Then, the characteristics of SPPs on various plasmonic waveguides are reviewed, including top-down and bottom-up fabricated types. Considering applications, certain prototypes of plasmonic devices and circuits constructed by plasmonic waveguides for bio/chemo sensing, router, and light modulation are demonstrated. Finally, a summary and future outlook of plasmonic waveguides are given.
文摘BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct
文摘Background： The recently emerged technology of methylated RNA immunoprecipitation sequencing （MeRIP-seq） sheds light on the study of RNA epigenetics. This new bioinformatics question calls for effective and robust peaking calling algorithms to detect mRNA methylation sites from MeRIP-seq data. Methods： We propose a Bayesian hierarchical model to detect methylation sites from MeRIP-seq data. Our modeling approach includes several important characteristics. First, it models the zero-inflated and over-dispersed counts by deploying a zero-inflated negative binomial model. Second, it incorporates a hidden Markov model （HMM） to account for the spatial dependency of neighboring read enrichment. Third, our Bayesian inference allows the proposed model to borrow strength in parameter estimation, which greatly improves the model stability when dealing with MeRIP-seq data with a small number of replicates. We use Markov chain Monte Carlo （MCMC） algorithms to simultaneously infer the model parameters in a de novo fashion. The R Shiny demo is available at https：//qiwei. shinyapps.io/BaySeqPeak and the R/C ＋＋ code is available at https：//github.com/liqiwei2000/BaySeqPeak. Results： In simulation studies, the proposed method outperformed the competing methods exomePeak and MeTPeak, especially when an excess of zeros were present in the data. In real MeRIP-seq data analysis, the proposed method identified methylation sites that were more consistent with biological knowledge, and had better spatial resolution compared to the other methods. Conclusions： In this study, we develop a Bayesian hierarchical model to identify methylation peaks in MeRIP-seq data. The proposed method has a competitive edge over existing methods in terms of accuracy, robustness and spatial resolution.
基金The work is supported by the National Key R&D Program of China(No.2020YFA0709900)National Natural Science Foundation of China(No.62288102,61874053,22075136,22105099,62105262 and 62205141)+7 种基金Natural Science Funds of the Education Committee of Jiangsu Province(No.18KA430009)the Natural Science Foundation of Jiangsu Province(No.BK202006700)the Six Peak Talents Foundation of Jiangsu Province(XCLCXTD-009)the"High-Level Talents in Six Industries"of Jiangsu Province(No.XYDxX-019)the China Postdoctoral Science Foundation(2022M711591)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_1284 and KYCX21_0772)the open research fund from the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology)the Anhui Province Key Laboratory of Optoelectronic Materials Science and Technology NO.OMST202101.Y.H.acknowledges support from Jiangsu Funding Program for Excellent Postdoctoral Talent.
文摘Doping and blending strategies are crucial means to precisely control the excited states and energy level in conjugated molecular systems.However,effective models and platforms are rarely proposed to systematically explore the effects of the formation of trapped doped centers on heterogeneous structures,energy level and ultrafast photophysical process.Herein,for deeply understanding the impact of molecular doping in film energy levels and photoexcitation dynamics,we set a supramolecular N-B coordination composed by the conjugated molecules of pyridine functionalized diarylfluorene(host material),named as ODPF-Phpy and ODPF-(Phpy)2,and the molecule of tris(perfluorophenyl)borane(BCF)(guest material).The generation of the molecular-level coordination bond increased the binding energy of N atoms and tuned the band-gap,leading to a new fluorescent emission center with longer excitation wavelength and emission wavelength.The intermolecular Forster resonance energy transfer(FRET)in blending flms make it present inconsistent fluorescent behaviors compared to that in solution.The charge transfer(CT)state of N-B coordinated compounds and the changed dielectric constant of blending films resulted in a large PL spectra red-shift with the increased dopant ratio,causing a wide-tunable fluorescent color.The excited state behaviors of two compounds in blending system was further investigated by the transient absorption(TA)spectroscopy.Finally,we found supramolecular coordination blending can effectively improve the films'photoluminescence quantum yield(PLQY)and conductivity.We believe this exploration in the internal coordination mechanisms would deepen the insights about doped semiconductors and is helpful in developing novel high-efficient fluorescent systems.
基金the Natural Science Foundation of China(No.81871147 and No.82071639)the Sichuan Science and Technology Program(No.2018SZ0019 and No,2018TJPT0018).
文摘Postprostatectomy erectile dysfunction(pPED)remains a current problem despite improvements in surgical techniques.Vacuum therapy is clinically confirmed as a type of pPED rehabilitation.However,its underlying mechanisms are incompletely understood.Recently,autophagy and apoptosis were extensively studied in erectile dysfunction resulting from diabetes,senescence,and androgen deprivation but not in the context of pPED and vacuum therapy.Therefore,this study was designed to investigate the roles of autophagy and apoptosis in pPED and vacuum therapy.Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups:the control group,bilateral cavernous nerve crush(BCNC)group,and BCNC+vacuum group.After 4 weeks of treatment,intracavernosal pressure was used to evaluate erectile function.Real-time quantitative polymerase chain reaction,western blot,and immunohistochemistry were used to measure the molecular expression.TdT-mediated dUTP nick-end labeling staining was used to assess apoptosis.Transmission electron microscopy was used to observe autophagosomes.After treatment,compared with those of the BCNC group,erectile function and cavernosal hypoxia had statistically significantly improved(P<0.05).Apoptosis and the relative protein expression of B-cell lymphoma-2-associated X and cleaved Caspase3 were decreased(P<0.05).Autophagy-related molecules such as phosphorylated unc-51-like autophagy-activating kinase 1(Ser757)and p62 were decreased.Beclinl,microtubule-associated protein 1 light chain 3 A/B,and autophagosomes were increased(P<0.05).Besides,the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway,as a negative regulator of autophagy to some degree,was inhibited.This study revealed that vacuum therapy ameliorated pPED in BCNC rats by inhibiting apoptosis and activating autophagy.
文摘Mesoporous Au films consisting of a network of interconnected Au ligaments around ultra-large pores were found to exhibit a promising electrocatalytic activity towards sluggish reactions. Mesoporous Au films with pore sizes up to 25 nm were successfully fabricated using a polymeric micelle approach. A superior catalytic activity of the mesoporous Au films towards methanol oxidation was confirmed, which was thoroughly analyzed and compared with that of other Au materials. An intrinsic investigation on the high catalytic activity revealed that the superior performance of the as-prepared mesoporous Au film was related to its unique atomic structures around the mesopores with well- crystallized facets and several step/kink sites on the Au surfaces. These findings showcase a strategic and feasible design for preparing highly active Au-based catalysts that could be used as promising candidates in electrocatalytic applications.
基金Supported by The Canadian Institutes of Health Research,No.319379
文摘Suicide is the second leading cause of death in youth globally; however, there is uncertainty about how best to intervene. Suicide rates are typically higher in males than females, while the converse is true for suicide attempts. We review this "gender paradox" in youth, and in particular, the age-dependency of these sex/gender differences and the developmental mechanisms that may explain them. Epidemiologic, genetic,neurodevelopmental and psychopathological research have identified suicidal behaviour risks arising from genetic vulnerabilities and sex/gender differences in early adverse environments, neurodevelopment, mental disorder and their complex interconnections. Further, evolving sex-/gender-defined social expectations and norms have been thought to influence suicide risk. In particular, how youth perceive and cope with threats and losses(including conforming to others' or one's own expectations of sex/gender identity) and adapt to pain(through substance use and helpseeking behaviours). Taken together, considering brain plasticity over the lifespan, these proposed antecedents to youth suicide highlight the importance of interventions that alter early environment(s)(e.g., childhood maltreatment) and/or one's ability to adapt to them. Further, such interventions may have more enduring protective effects, for the individual and for future generations, if implemented in youth.
基金Supported by the National Key Research and Development Program of China under Grant Nos 2017YFA0303003,2016YFA0300300 and 2015CB921000the National Natural Science Foundation of China under Grant Nos 11574370,11474338,11674374 and 61501220+1 种基金the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences under Grant Nos QYZDY-SSW-SLH001,QYZDY-SSW-SLH008 and XDB07020100the Beijing Municipal Science and Technology Project under Grant No Z161100002116011
文摘The phenomenon of phase separation into antiferromagnetic（AFM） and superconducting（SC） or normal-state regions has great implication for the origin of high-temperature（high-T_c） superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the T_c of（Li,Fe）OHFe Se superconductor is questioned. Here we report a systematic study on a series of（Li,Fe）OHFe Se single crystal samples with T_c up to ～41 K. We observe an evident drop in the static magnetization at T_（afm） ～ 125 K, in some of the SC（T_c 38 K, cell parameter c■9.27 ？） and non-SC samples. We verify that this AFM signal is intrinsic to（Li,Fe）OHFe Se. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal（below T_（afm）） or SC（below T_c） state in（Li,Fe）OHFe Se. We explain such coexistence by electronic phase separation, similar to that in high-T_c cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of（Li,Fe）OHFe Se, particularly it is never observed in the SC samples of T_c 38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. The occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as T_（afm）, reported previously for a（Li,Fe）OHFe Se（T_c ～ 42 K） single crystal, suggests that the microscopic static phase separation reaches vanishing point in high T_c（Li,Fe）OHFe Se. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-T_c superconductivity.
基金supported by the National Natural Science Foundation of China(No.52173034)the Science and Technology Innovation Program of Hunan Province of China(Nos.2023JJ30081,2022JJ40523 and 2021JJ50009)+1 种基金the Science Research Foundation of Hunan Provincial Education Department of China(No.21A0546)the Changsha Municipal Science and Technology Project(No.kq2203005).
文摘The microstructure and stress rupture properties of Inconel 706 alloy microalloyed with phosphorus are examined under stabilizing and unstabilizing heat treatment conditions.It was found that applying the stabilizing treatment resulted in a 98% increment in the stress rupture life and a 215% increment in the elongation tested at 650℃/690 MPa for the alloy compared to that under the unstabilizing heat treatment condition.The stabilizing treatment led to the precipitation of rod-shaped and needle-shaped n phases at the grain boundaries.Morphologies of γ'-γ" co-precipitates in the grain interior were noncompact form and compact form for the alloy under unstabilizing and stabilizing heat treatment conditions,respectively.Based on the microstructure characterizations,the improvement of stress rupture properties by the stabilizing treatment was attributed to the precipitation of n phases at the grain boundaries,which can hinder cracks initiation and propagation and relieve the stress concentration.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51677008,51377182,51707028,and 11647098)the Fundamental Research Funds of the Central Universities,China(Grant No.106112017CDJQJ158834)the State Key Development Program for Basic Research of China(Grant No.2014CB541602)
文摘The conventional magnetic resonance imaging(MRI)equipment cannot measure large volume samples nondestructively in the engineering site for its heavy weight and closed structure.In order to realize the mobile MRI,this study focuses on the design of gradient coil of unilateral magnet.The unilateral MRI system is used to image the local area above the magnet.The current density distribution of the gradient coil cannot be used as a series of superconducting nuclear magnetic resonance gradient coils,because the region of interest(ROI)and the wiring area of the unilateral magnet are both cylindrical side arc surfaces.Therefore,the equivalent magnetic dipole method is used to design the gradient coil,and the algorithm is improved for the special case of the wiring area and the ROI,so the X and Y gradient coils are designed.Finally,a flexible printed circuit board(PCB)is used to fabricate the gradient coil,and the magnetic field distribution of the ROI is measured by a Gauss meter,and the measured results match with the simulation results.The gradient linearities of x and y coils are 2.82%and 3.56%,respectively,less than 5%of the commercial gradient coil requirement.
基金The Swedish Research Council no. 14548-04-3 the Scania ALF foundation Sjöbring Foundation
文摘A variety of factors have been identified as being risk factors for suicidal behaviour. One of them is the handling of stressful events. The aim of the present study was to investigate the coping-strategies used by suicide attempters and comparison groups. 37 patients who had recently made a suicide attempt, 38 suicide attempters at follow up, 20 psychiatric follow up controls, and 19 healthy controls filled in the COPE. We found that suicide attempters at long term follow up and healthy controls used more adaptive problem solving strategies than patients who had recently made a suicide attempt, or psychiatric controls at follow up, who used more maladaptive coping strategies. Our findings suggest that suicide attempters in a twelve year follow up are able to use coping strategies similarly to healthy controls by e.g. approaching the stressor actively. Further examinations of the impact of long term professional care and treatment of suicide attempters on their coping strategies are necessary.
