Development of highly active and stable non-noble electrocatalysts with well-defined nanostructures is crucial for efficient hydrogen evolution reaction(HER). Herein, a novel three-dimensional(3D) selfsupported electr...Development of highly active and stable non-noble electrocatalysts with well-defined nanostructures is crucial for efficient hydrogen evolution reaction(HER). Herein, a novel three-dimensional(3D) selfsupported electrode consists of vanadium nitride(VN) nanodots and Co nanoparticles co-embedded and highly active single Co atoms anchored in N-doped carbon nanotubes supported on carbon cloth(VN-Co@CoSAs-NCNTs/CC) is fabricated via a one-step in situ nanoconfined pyrolysis strategy, which shows remarkable enhanced HER electrocatalytic activity in acidic medium. During pyrolysis, the formed VN nanodots induce the generation of atomic Co Nxsites in NCNTs, contributing to superior electrocatalytic activity. Experimental and density functional theory(DFT) calculation results reveal that the electrode has multiple accessible active sites, fast reaction kinetics, low charge/mass transfer resistances,high conductivity, as well as downshifted d-band center with a thermodynamically favorable hydrogen adsorption free energy(△G_(H·)), all of which greatly boost the HER performance. As a result, the VNCo@CoSAs-NCNTs/CC electrode displays superb catalytic performance toward HER with a low overpotential of 29 mV at 10 mA cm^(-2) in acidic medium, which could maintain for at least 60 h of stable performance. This work opens a facile avenue to explore low-cost, high performance, but inexpensive metals/nitrogen-doped carbon composite electrocatalysts for HER.展开更多
The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were per...The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were performed using a finite element method (FEM) to obtain virtual experiment data. In the present research, the size of the side damage from a collision phenomenon were measured and used to verify the numerical configuration together with the calculation results using an empirical equation. Parameters in the external dynamics of a ship collision such as the location of the contact point and velocity of the striking ship were taken into consideration. The internal energy and deformation size on the side structure were discussed further in a comparative study. The effects of the selected parameters on several structural behaviors, namely energy, force, and damage extent were also observed and evaluated in this section. Stiffener on side hull was found to contribute significantly into resistance capability of the target ship against penetration of the striking bow. Remarkable force during penetration was observed to occur when inner shell was crushed as certain velocity was applied in the striking bow.展开更多
Reaumuria soongorica is a short woody shrub widely found in semi-arid areas of China. It can survive severe environ- mental stress including high salinity in its natural habitat. Thus, we investigated the involvement ...Reaumuria soongorica is a short woody shrub widely found in semi-arid areas of China. It can survive severe environ- mental stress including high salinity in its natural habitat. Thus, we investigated the involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of R. soongorica to saline environments. R. soon- gorica was treated with 0, 100, 200 and 400 mM NaC1 solutions for 14 days. Soil salt content increased significantly by watering with high content of NaC1 solution, and no variation between 8 and 14 days during treatment. The levels ofpe- roxidation of lipid membranes (measured by malondialdehyde content) and the activities of three antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX)) increased under salt stress. Chlorophyll and carotenoid content decreased with increasing salt content. The ratio of Chl a/Chl b and carotenoid/Chl exhibited sig- nificant increase under 400 mM NaC1. However, total flavonoid and anthocyanin contents and key enzyme activities in the flavonoid pathway including phenylalanine ammonialyase (PAL) and Chalcone isomerase (CHI) decreased under salt stress. These findings possibly suggest that R. soongorica has an adaptation protection mechanism against salt-induced oxidative damage by inducin~ the activity of antioxidant enzymes and maintaining a steady level of carotenoid/Chl.展开更多
Metal–N–C single‐atom catalysts,mostly prepared from pyrolysis of metalorganic precursors,are widely used in heterogeneous electrocatalysis.Since metal sites with diverse local structures coexist in this type of ma...Metal–N–C single‐atom catalysts,mostly prepared from pyrolysis of metalorganic precursors,are widely used in heterogeneous electrocatalysis.Since metal sites with diverse local structures coexist in this type of material and it is challenging to characterize the local structure,a reliable structure–property relationship is difficult to establish.Conjugated macrocyclic complexes adsorbed on carbon support are well‐defined models to mimic the singleatom catalysts.Metal–N_(4) site with four electroneutral pyridine‐type ligands embedded in a graphene layer is the most commonly proposed structure of the active site of single‐atom catalysts,but its molecular counterpart has not been reported.In this work,we synthesized the conjugated macrocyclic complexes with a metal center(Co,Fe,or Ni)coordinated with four electroneutral pyridinic ligands as model catalysts for CO_(2) electroreduction.For comparison,the complexes with anionic quadri‐pyridine macrocyclic ligand were also prepared.The Co complex with the electroneutral ligand expressed a turnover frequency of CO formation more than an order of magnitude higher than that of the Co complex with the anionic ligand.Constrained ab initio molecular dynamics simulations based on the well‐defined structures of the model catalysts indicate that the Co complex with the electroneutral ligand possesses a stronger ability to mediate electron transfer from carbon to CO_(2).展开更多
As a core part of battlefield situational awareness,air target intention recognition plays an important role in modern air operations.Aiming at the problems of insufficient feature extraction and misclassification in ...As a core part of battlefield situational awareness,air target intention recognition plays an important role in modern air operations.Aiming at the problems of insufficient feature extraction and misclassification in intention recognition,this paper designs an air target intention recognition method(KGTLIR)based on Knowledge Graph and Deep Learning.Firstly,the intention recognition model based on Deep Learning is constructed to mine the temporal relationship of intention features using dilated causal convolution and the spatial relationship of intention features using a graph attention mechanism.Meanwhile,the accuracy,recall,and F1-score after iteration are introduced to dynamically adjust the sample weights to reduce the probability of misclassification.After that,an intention recognition model based on Knowledge Graph is constructed to predict the probability of the occurrence of different intentions of the target.Finally,the results of the two models are fused by evidence theory to obtain the target’s operational intention.Experiments show that the intention recognition accuracy of the KGTLIRmodel can reach 98.48%,which is not only better than most of the air target intention recognition methods,but also demonstrates better interpretability and trustworthiness.展开更多
One-dimensional semiconductor materials possess excellent photoelectric properties and potential for the construction of integrated nanodevices. Among them, Sn-doped CdS has different micro-nano structures, including ...One-dimensional semiconductor materials possess excellent photoelectric properties and potential for the construction of integrated nanodevices. Among them, Sn-doped CdS has different micro-nano structures, including nanoribbons,nanowires, comb-like structures, and superlattices, with rich optical microcavity modes, excellent optical properties, and a wide range of application fields. This article reviews the research progress of various micrometer structures of Sn-doped CdS, systematically elaborates the effects of different growth conditions on the preparation of Sn-doped CdS micro-nano structures, as well as the spectral characteristics of these structures and their potential applications in certain fields. With the continuous progress of nanotechnology, it is expected that Sn-doped CdS micro-nano structures will achieve more breakthroughs in the field of optoelectronics and form cross-integration with other fields, jointly promoting scientific, technological, and social development.展开更多
仙灵骨葆口服制剂是我国治疗骨病的中药大品种,但近年来国家食品药品监督管理总局通报其易引起肝损伤。传统毒理学研究很难评价其肝损伤作用,我们前期发现仙灵骨葆肝损伤具有特异质属性,拆方研究发现补骨脂和淫羊藿是其导致特异质肝损...仙灵骨葆口服制剂是我国治疗骨病的中药大品种,但近年来国家食品药品监督管理总局通报其易引起肝损伤。传统毒理学研究很难评价其肝损伤作用,我们前期发现仙灵骨葆肝损伤具有特异质属性,拆方研究发现补骨脂和淫羊藿是其导致特异质肝损伤的主要药味,且配伍后其特异质肝损伤加重,呈现七情配伍中“相反”的特点。进一步研究发现,TNF-α介导的免疫应激是其重要诱因,免疫促进成分和肝损伤易感成分存在是其另一重要诱因。然而,具体机制尚不清楚。本研究通过建立动物模型,考察了免疫促进淫羊藿次苷Ⅱ联合肝损伤易感成分补骨脂甲素对小鼠肝损伤的影响;借助非靶向代谢组学技术评价了两个成分联合对肝损伤代谢标志物的影响;利用16S r RNA测序技术探讨了肠道菌群的物种组成和相对丰度的变化。结果表明在TNF-α诱导的免疫应激小鼠模型上发现,单独给药补骨脂甲素能够引起明显肝损伤,而淫羊藿次苷Ⅱ组却无明显变化,但是淫羊藿次苷Ⅱ能够协同补骨脂甲素导致特异质肝损伤;同时代谢组学结果揭示补骨脂甲素联合淫羊藿次苷Ⅱ能够引起小鼠肝脏中甲基氨基甲酰PAF、吲哚-3-醋酸甲酯等代谢物的水平升高,而甘氨酸-酪氨酸(Gly-Tyr)、L-亮氨酰-L-甘氨酸(Leu-Gly)和L-色氨酸-L-丝氨酸(Trp-Ser)等代谢物的水平则下降。这些与肝损伤相关的差异表达代谢物主要富集在鞘脂代谢、鞘脂信号通路和坏死等代谢途径。值得注意的是,补骨脂甲素联合淫羊藿次苷Ⅱ可以诱导肝损伤小鼠肠道中的乳酸杆菌和脱硫弧菌科丰度显著增加。相关性分析结果表明,类杆菌科和脱硫弧菌科与甲基氨基甲酰基PAF和吲哚-3-醋酸甲酯呈正相关,而与Gly-Tyr、Leu-Gly和Trp-Ser呈负相关。本研究初步阐明了补骨脂配伍淫羊藿引起特异质型药物性肝损伤的物质基础和机制,为中成药临床合理使用提供了科学依据。展开更多
This paper introduces the method of coal dust treatment in crushing station and the present situation of dust removal system in typical open-pit coal mine crushing station in China,and expounds the research idea of de...This paper introduces the method of coal dust treatment in crushing station and the present situation of dust removal system in typical open-pit coal mine crushing station in China,and expounds the research idea of determining comprehensive dust removal(suppression)system in crushing station inspired by the working principle of"range hood".Based on the design example and link optimization of the crush-ing station of open-pit coal mine I of Thar coalfield,this paper finally draws some conclusions on the key technologies of dust removal(suppression)system of open-pit coal mine crushing station.This study has certain reference value for the technical innovation of dust removal(suppression)system in crushing station,the realization of green mining in"crushing link",and the reduction and avoidance of ecological environment pollution in mining area.展开更多
Artificial neural networks(ANNs)are one of the primary types of artificial intelligence and have been rapidly developed and used in many fields.In recent years,there has been a sharp increase in research concerning AN...Artificial neural networks(ANNs)are one of the primary types of artificial intelligence and have been rapidly developed and used in many fields.In recent years,there has been a sharp increase in research concerning ANNs in gastrointestinal(GI)diseases.This state-of-the-art technique exhibits excellent performance in diagnosis,prognostic prediction,and treatment.Competitions between ANNs and GI experts suggest that efficiency and accuracy might be compatible in virtue of technique advancements.However,the shortcomings of ANNs are not negligible and may induce alterations in many aspects of medical practice.In this review,we introduce basic knowledge about ANNs and summarize the current achievements of ANNs in GI diseases from the perspective of gastroenterologists.Existing limitations and future directions are also proposed to optimize ANN’s clinical potential.In consideration of barriers to interdisciplinary knowledge,sophisticated concepts are discussed using plain words and metaphors to make this review more easily understood by medical practitioners and the general public.展开更多
The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and erro...The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and error experiment to obtain the desirable processing technology.The EDEM simulation of the spindle barrel finishing can provide effective help for the process design,however,the difference between the simulation and experiment is closely related to the selection of the contact model during simulation.In this paper,simulations and experiments are conducted based on the identical apparatus and conditions to facilitate the comparison and validation between each other.Based on the Hertz contact theory,the effect of the material properties of contact objects and the relative position of the workpiece on the contact force is qualified.The expression of the correlation coefficient of the contact model is deduced.Then the formula for calculating the contact force between the barrel finishing abrasive and the workpiece that includes influence coefficient of the material properties and the relative positions is established.Finally,the contact force calculation formula is verified by changing the rotating speed.The result shows that the material correction coefficient ranges from 1.41 to 2.38,which is inversely related to the equivalent modulus E.The position correction coefficient ranges from 2.0 to 2.3.The relative error value between the calculation result and the experimental test result is from 0.58%to 14.07%.This research lay a theoretical foundation for the correction theory of the core elements of the spindle barrel finishing process.展开更多
The potential survival benefit of neoadjuvant chemotherapy(NC)in patients with advanced gastric cancer has been widely recognized.With the development of minimally invasive surgery,which is represented by laparoscopy,...The potential survival benefit of neoadjuvant chemotherapy(NC)in patients with advanced gastric cancer has been widely recognized.With the development of minimally invasive surgery,which is represented by laparoscopy,the effect of NC on the safety of laparoscopic gastrectomy remains to be further explored.AIM To compare the short-term outcomes of laparoscopic total gastrectomy(LTG)after NC(NC-LTG)with LTG alone.METHODS A total of 92 patients who underwent NC-LTG and 381 patients who received LTG alone at the Chinese PLA General Hospital between September 2015 and September 2020 were retrospectively included in our study.We used propensityscore matching(PSM)to balance baseline bias.After 1:1 PSM,73 patients were included in each group with no statistically significant difference in baseline characteristics.RESULTS The NC-LTG group exhibited a longer operation time(244.10±48.13 min vs 225.74±45.33 min,P=0.019)and increased intraoperative blood loss[150(100-300)mL vs 100(100-200)mL,P=0.011]compared to the LTG group.The 30-d postoperative morbidity of the NC-LTG group was 20.5%(15/73),and that of the LTG group was 13.7%(10/73).There were no significant differences in 30-d severe complication rates or anastomotic leakage rates.Subgroup analysis showed that the patients with pTNM(pathological tumor-node-metastasis classification)T0N0-II in the NC-LTG group underwent a longer operation than the LTG group,while no significant difference was found in any perioperative index for the pTNM III patients.A multivariate analysis showed that an operation time longer than 240 min was an independent risk factor(odds ratio=3.021,95%confidence interval:1.160-7.868,P=0.024),while NC was not an independent risk factor for postoperative complications in LTG.CONCLUSION Despite a longer operation time and more blood loss after NC-LTG,which indicate surgical difficulty,NC-LTG exhibits acceptable short-term outcomes compared to LTG,suggesting the safety and feasibility of NC-LTG.展开更多
In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are el...In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure.展开更多
Background: Traumatic colon injury(TCI) is a common disease during wartime. Prolongation of posttraumatic survival time is an effective approach to patient outcome improvement. However, there is a lack of basic resear...Background: Traumatic colon injury(TCI) is a common disease during wartime. Prolongation of posttraumatic survival time is an effective approach to patient outcome improvement. However, there is a lack of basic research in this field.This study aimed to elucidate the mechanisms underlying TCI progression and to develop novel regimens to buy time for TCI patients on the battlefield.Methods: A total of 669 Sprague–Dawley rats were used in this study. Surgical colon incision was performed to generate the TCI rat model. The landscape of colon microbiota compositions was depicted using 16S rRNA sequencing and metabolites in the intestinal contents were detected by metabolomics profiling. The signaling transduction in the intestinal epithelium was investigated using antibody microarrays and Western blotting. The enzyme-linked immunosorbent assay(ELISA) was conducted to measure the levels of interleukin-6 and tumor necrosis factor-α in intestines and plasma for the detection of inflammatory responses. Diamine oxidase, D-lactate and endotoxin in plasma and protein expression of zonula occludens 1 and occludin were selected as the indicators of intestinal barrier permeability. To investigate alterations of microbiota symbiosis, the relative abundances of specific bacterial genera were detected using quantitative real-time PCR(qRT-PCR).Results: As a type of lethal injury, TCI induced acute disruption of intestinal homeostasis, characterized by inflammatory responses, intestinal barrier hyperpermeability and microbiota dysbiosis(P<0.05). Significant alterations in bacterial metabolic patterns were detected with decreases in many metabolites. After a series of screenings,we found that oral administration of asparagine(Asn) and 3-indolepropionic acid(IPA) effectively prolonged posttraumatic survival time [Asn plus IPA vs. Vehicle: hazard ratio(HR)=0.105, 95%CI 0.031–0.356, P=0.0003] and restored intestinal homeostasis in TCI rats(P<0.05). Mechanistically, this combinational strategy protected the rats against TCI through synergistic activation of Akt signaling in the intestinal epithelium(P<0.05).Conclusions: Abrupt dysregulation of intestinal homeostasis plays a critical role in the progression toward TCI induced death. Oral administration of Asn plus IPA may serve as an effective regimen to restore intestinal functions and prolong the posttraumatic survival time.展开更多
Li and Mn rich(LMR)layered oxides,written as xLi_(2) MnO_(3)·(1-x)LiMO_(2)(M=Mn,Ni,Co,Fe,etc.),have been widely reported in recent years due to their high capacity and high energy density.The stable structure and...Li and Mn rich(LMR)layered oxides,written as xLi_(2) MnO_(3)·(1-x)LiMO_(2)(M=Mn,Ni,Co,Fe,etc.),have been widely reported in recent years due to their high capacity and high energy density.The stable structure and superior performance of LMR oxides make them one of the most promising candidates for the next-generation cathode materials.However,the commercialization of these materials is hindered by several drawbacks,such as low initial Coulombic efficiency,the degradation of voltage and capacity during cycling,and poor rate performance.This review summarizes research progress in solving these concerns of LMR cathodes over the past decade by following three classes of strategies:morphology design,bulk design,and surface modification.We elaborate on the processing procedures,electrochemical performance,mechanisms,and limitations of each approach,and finally put forward the concerns left and the possible solutions for the commercialization of LMR cathodes.展开更多
Objective: The aim of the study was to observe the clinical efficacy with Yiqi Jianpi decoction combination with FOLFOX4 for the postoperative patients of colorectal cancer (CRC). Methods: Eighty-five patients were ra...Objective: The aim of the study was to observe the clinical efficacy with Yiqi Jianpi decoction combination with FOLFOX4 for the postoperative patients of colorectal cancer (CRC). Methods: Eighty-five patients were randomly divided into two groups. The treated group (n = 41) received Yiqi Jianpi decoction combined with FOLFOX4 chemotherapy and the control group (n = 44) received FLOFOX4 chemotherapy alone. A treatment course of 6 months was applied to both groups. Results: The life quality, symptomatic improvement and adverse side effects reducing in the treated group were better than those of the control group. Conclusion: Yiqi Jianpi decoction combination with FOLFOX4 chemotherapy is effective in the treatment of the postoperative patients with colorectal cancer.展开更多
BACKGROUND Neoadjuvant chemotherapy(NACT)combined with surgery is regarded as an effective treatment for advanced gastric cancer(AGC).Laparoscopic surgery represents the mainstream of minimally invasive surgery.Curren...BACKGROUND Neoadjuvant chemotherapy(NACT)combined with surgery is regarded as an effective treatment for advanced gastric cancer(AGC).Laparoscopic surgery represents the mainstream of minimally invasive surgery.Currently,surgeons focus more on surgical safety and oncological outcomes of laparoscopic gastrectomy after NACT.Thus,we sought to evaluate short-and long-term outcomes between laparoscopic total gastrectomy(LTG)and open total gastrectomy(OTG)after NACT.AIM To compare the short and long-term outcomes between LTG and OTG for AGC after NACT.METHODS We retrospectively collected the clinicopathological data of 136 patients who accepted gastrectomy after NACT from June 2012 to June 2019,including 61 patients who underwent LTG and 75 who underwent OTG.Clinicopathological characteristics between the LTG and OTG groups showed no significant difference.SPSS 26.0,R software,and GraphPad PRISM 8.0 were used to perform statistical analyses.RESULTS Of the 136 patients included,eight acquired pathological complete response,and the objective response rate was 47.8%(65/136).The LTG group had longer operation time(P=0.015),less blood loss(P=0.003),shorter days to first flatus(P<0.001),and shorter postoperative hospitalization days(P<0.001).LTG spent more surgical cost than OTG(P<0.001),while total hospitalized cost of LTG was less than OTG(P<0.001).21(28.0%)patients in the OTG group and 14(23.0%)in the LTG group had 30-d postoperative complications,but there was no significant difference between the two groups(P=0.503).The 3-year overall survival(OS)rate was 60.6%and 64.6%in the LTG and OTG groups,respectively[hazard ratio(HR)=0.859,95%confidence interval(CI):0.522-1.412,P=0.546],while the 3-year disease-free survival(DFS)rate was 54.5%and 51.8%in the LTG and OTG group,respectively(HR=0.947,95%CI:0.582-1.539,P=0.823).Multivariate cox analysis showed that body mass index and pTNM stage were independent risk factors for OS while vascular invasion and pTNM stage were independent risk factors for DFS(P<0.05).CONCLUSION After NACT,LTG shows comparable 30-d postoperative morbidity as well as 3-year OS and DFS rate to OTG.We recommend that experienced surgeons select LTG other than OTG for proper AGC patients after NACT.展开更多
基金supported by grants from the National Natural Science Foundation of China (21971129, 21961022, 21661023,21802076, and 21962013)the 111 Project (D20033)+2 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region of China (2018BS05007)the Program of Higher-level Talents of IMU (21300-5195109)the Cooperation Project of State Key Laboratory of Baiyun Obo Rare Earth Resource Researches and Comprehensive Utilization (2017Z1950)。
文摘Development of highly active and stable non-noble electrocatalysts with well-defined nanostructures is crucial for efficient hydrogen evolution reaction(HER). Herein, a novel three-dimensional(3D) selfsupported electrode consists of vanadium nitride(VN) nanodots and Co nanoparticles co-embedded and highly active single Co atoms anchored in N-doped carbon nanotubes supported on carbon cloth(VN-Co@CoSAs-NCNTs/CC) is fabricated via a one-step in situ nanoconfined pyrolysis strategy, which shows remarkable enhanced HER electrocatalytic activity in acidic medium. During pyrolysis, the formed VN nanodots induce the generation of atomic Co Nxsites in NCNTs, contributing to superior electrocatalytic activity. Experimental and density functional theory(DFT) calculation results reveal that the electrode has multiple accessible active sites, fast reaction kinetics, low charge/mass transfer resistances,high conductivity, as well as downshifted d-band center with a thermodynamically favorable hydrogen adsorption free energy(△G_(H·)), all of which greatly boost the HER performance. As a result, the VNCo@CoSAs-NCNTs/CC electrode displays superb catalytic performance toward HER with a low overpotential of 29 mV at 10 mA cm^(-2) in acidic medium, which could maintain for at least 60 h of stable performance. This work opens a facile avenue to explore low-cost, high performance, but inexpensive metals/nitrogen-doped carbon composite electrocatalysts for HER.
文摘The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were performed using a finite element method (FEM) to obtain virtual experiment data. In the present research, the size of the side damage from a collision phenomenon were measured and used to verify the numerical configuration together with the calculation results using an empirical equation. Parameters in the external dynamics of a ship collision such as the location of the contact point and velocity of the striking ship were taken into consideration. The internal energy and deformation size on the side structure were discussed further in a comparative study. The effects of the selected parameters on several structural behaviors, namely energy, force, and damage extent were also observed and evaluated in this section. Stiffener on side hull was found to contribute significantly into resistance capability of the target ship against penetration of the striking bow. Remarkable force during penetration was observed to occur when inner shell was crushed as certain velocity was applied in the striking bow.
基金financially supported by the National Natural Science Foundation of China(31070358,91125029,31160089 and 31000181)
文摘Reaumuria soongorica is a short woody shrub widely found in semi-arid areas of China. It can survive severe environ- mental stress including high salinity in its natural habitat. Thus, we investigated the involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of R. soongorica to saline environments. R. soon- gorica was treated with 0, 100, 200 and 400 mM NaC1 solutions for 14 days. Soil salt content increased significantly by watering with high content of NaC1 solution, and no variation between 8 and 14 days during treatment. The levels ofpe- roxidation of lipid membranes (measured by malondialdehyde content) and the activities of three antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX)) increased under salt stress. Chlorophyll and carotenoid content decreased with increasing salt content. The ratio of Chl a/Chl b and carotenoid/Chl exhibited sig- nificant increase under 400 mM NaC1. However, total flavonoid and anthocyanin contents and key enzyme activities in the flavonoid pathway including phenylalanine ammonialyase (PAL) and Chalcone isomerase (CHI) decreased under salt stress. These findings possibly suggest that R. soongorica has an adaptation protection mechanism against salt-induced oxidative damage by inducin~ the activity of antioxidant enzymes and maintaining a steady level of carotenoid/Chl.
基金Guangdong Grants,Grant/Award Number:2021ZT09C064National Natural Science Foundation of China,Grant/Award Numbers:22272073,22373045,22373045+2 种基金Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20210324104414039,JCYJ20220818100410023,KCXST20221021111207017Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2021A1515110360,2022A1515011976China Postdoctoral Science Foundation,Grant/Award Number:2022M721469。
文摘Metal–N–C single‐atom catalysts,mostly prepared from pyrolysis of metalorganic precursors,are widely used in heterogeneous electrocatalysis.Since metal sites with diverse local structures coexist in this type of material and it is challenging to characterize the local structure,a reliable structure–property relationship is difficult to establish.Conjugated macrocyclic complexes adsorbed on carbon support are well‐defined models to mimic the singleatom catalysts.Metal–N_(4) site with four electroneutral pyridine‐type ligands embedded in a graphene layer is the most commonly proposed structure of the active site of single‐atom catalysts,but its molecular counterpart has not been reported.In this work,we synthesized the conjugated macrocyclic complexes with a metal center(Co,Fe,or Ni)coordinated with four electroneutral pyridinic ligands as model catalysts for CO_(2) electroreduction.For comparison,the complexes with anionic quadri‐pyridine macrocyclic ligand were also prepared.The Co complex with the electroneutral ligand expressed a turnover frequency of CO formation more than an order of magnitude higher than that of the Co complex with the anionic ligand.Constrained ab initio molecular dynamics simulations based on the well‐defined structures of the model catalysts indicate that the Co complex with the electroneutral ligand possesses a stronger ability to mediate electron transfer from carbon to CO_(2).
基金funded by the Project of the National Natural Science Foundation of China,Grant Number 72071209.
文摘As a core part of battlefield situational awareness,air target intention recognition plays an important role in modern air operations.Aiming at the problems of insufficient feature extraction and misclassification in intention recognition,this paper designs an air target intention recognition method(KGTLIR)based on Knowledge Graph and Deep Learning.Firstly,the intention recognition model based on Deep Learning is constructed to mine the temporal relationship of intention features using dilated causal convolution and the spatial relationship of intention features using a graph attention mechanism.Meanwhile,the accuracy,recall,and F1-score after iteration are introduced to dynamically adjust the sample weights to reduce the probability of misclassification.After that,an intention recognition model based on Knowledge Graph is constructed to predict the probability of the occurrence of different intentions of the target.Finally,the results of the two models are fused by evidence theory to obtain the target’s operational intention.Experiments show that the intention recognition accuracy of the KGTLIRmodel can reach 98.48%,which is not only better than most of the air target intention recognition methods,but also demonstrates better interpretability and trustworthiness.
基金supported by National Natural Science Foundation of China (52275551)Shanxi Scholarship Council of China (2021-117)。
文摘One-dimensional semiconductor materials possess excellent photoelectric properties and potential for the construction of integrated nanodevices. Among them, Sn-doped CdS has different micro-nano structures, including nanoribbons,nanowires, comb-like structures, and superlattices, with rich optical microcavity modes, excellent optical properties, and a wide range of application fields. This article reviews the research progress of various micrometer structures of Sn-doped CdS, systematically elaborates the effects of different growth conditions on the preparation of Sn-doped CdS micro-nano structures, as well as the spectral characteristics of these structures and their potential applications in certain fields. With the continuous progress of nanotechnology, it is expected that Sn-doped CdS micro-nano structures will achieve more breakthroughs in the field of optoelectronics and form cross-integration with other fields, jointly promoting scientific, technological, and social development.
基金supported by the National Natural Science Foundation of China (82174071)。
文摘仙灵骨葆口服制剂是我国治疗骨病的中药大品种,但近年来国家食品药品监督管理总局通报其易引起肝损伤。传统毒理学研究很难评价其肝损伤作用,我们前期发现仙灵骨葆肝损伤具有特异质属性,拆方研究发现补骨脂和淫羊藿是其导致特异质肝损伤的主要药味,且配伍后其特异质肝损伤加重,呈现七情配伍中“相反”的特点。进一步研究发现,TNF-α介导的免疫应激是其重要诱因,免疫促进成分和肝损伤易感成分存在是其另一重要诱因。然而,具体机制尚不清楚。本研究通过建立动物模型,考察了免疫促进淫羊藿次苷Ⅱ联合肝损伤易感成分补骨脂甲素对小鼠肝损伤的影响;借助非靶向代谢组学技术评价了两个成分联合对肝损伤代谢标志物的影响;利用16S r RNA测序技术探讨了肠道菌群的物种组成和相对丰度的变化。结果表明在TNF-α诱导的免疫应激小鼠模型上发现,单独给药补骨脂甲素能够引起明显肝损伤,而淫羊藿次苷Ⅱ组却无明显变化,但是淫羊藿次苷Ⅱ能够协同补骨脂甲素导致特异质肝损伤;同时代谢组学结果揭示补骨脂甲素联合淫羊藿次苷Ⅱ能够引起小鼠肝脏中甲基氨基甲酰PAF、吲哚-3-醋酸甲酯等代谢物的水平升高,而甘氨酸-酪氨酸(Gly-Tyr)、L-亮氨酰-L-甘氨酸(Leu-Gly)和L-色氨酸-L-丝氨酸(Trp-Ser)等代谢物的水平则下降。这些与肝损伤相关的差异表达代谢物主要富集在鞘脂代谢、鞘脂信号通路和坏死等代谢途径。值得注意的是,补骨脂甲素联合淫羊藿次苷Ⅱ可以诱导肝损伤小鼠肠道中的乳酸杆菌和脱硫弧菌科丰度显著增加。相关性分析结果表明,类杆菌科和脱硫弧菌科与甲基氨基甲酰基PAF和吲哚-3-醋酸甲酯呈正相关,而与Gly-Tyr、Leu-Gly和Trp-Ser呈负相关。本研究初步阐明了补骨脂配伍淫羊藿引起特异质型药物性肝损伤的物质基础和机制,为中成药临床合理使用提供了科学依据。
文摘This paper introduces the method of coal dust treatment in crushing station and the present situation of dust removal system in typical open-pit coal mine crushing station in China,and expounds the research idea of determining comprehensive dust removal(suppression)system in crushing station inspired by the working principle of"range hood".Based on the design example and link optimization of the crush-ing station of open-pit coal mine I of Thar coalfield,this paper finally draws some conclusions on the key technologies of dust removal(suppression)system of open-pit coal mine crushing station.This study has certain reference value for the technical innovation of dust removal(suppression)system in crushing station,the realization of green mining in"crushing link",and the reduction and avoidance of ecological environment pollution in mining area.
基金National Natural Science Foundation of China,No.81773135 and No.82073192。
文摘Artificial neural networks(ANNs)are one of the primary types of artificial intelligence and have been rapidly developed and used in many fields.In recent years,there has been a sharp increase in research concerning ANNs in gastrointestinal(GI)diseases.This state-of-the-art technique exhibits excellent performance in diagnosis,prognostic prediction,and treatment.Competitions between ANNs and GI experts suggest that efficiency and accuracy might be compatible in virtue of technique advancements.However,the shortcomings of ANNs are not negligible and may induce alterations in many aspects of medical practice.In this review,we introduce basic knowledge about ANNs and summarize the current achievements of ANNs in GI diseases from the perspective of gastroenterologists.Existing limitations and future directions are also proposed to optimize ANN’s clinical potential.In consideration of barriers to interdisciplinary knowledge,sophisticated concepts are discussed using plain words and metaphors to make this review more easily understood by medical practitioners and the general public.
基金Supported by Program National Natural Science Foundation of China(Grant Nos.51875389,51975399,52075362)Key Program of Natural Science Foundation of Shanxi Province of China(Grant No.201801D111002)Scientific and Technological Innovation Project for Excellent Talents in Shanxi Province of China(Grant No.201805D211031).
文摘The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and error experiment to obtain the desirable processing technology.The EDEM simulation of the spindle barrel finishing can provide effective help for the process design,however,the difference between the simulation and experiment is closely related to the selection of the contact model during simulation.In this paper,simulations and experiments are conducted based on the identical apparatus and conditions to facilitate the comparison and validation between each other.Based on the Hertz contact theory,the effect of the material properties of contact objects and the relative position of the workpiece on the contact force is qualified.The expression of the correlation coefficient of the contact model is deduced.Then the formula for calculating the contact force between the barrel finishing abrasive and the workpiece that includes influence coefficient of the material properties and the relative positions is established.Finally,the contact force calculation formula is verified by changing the rotating speed.The result shows that the material correction coefficient ranges from 1.41 to 2.38,which is inversely related to the equivalent modulus E.The position correction coefficient ranges from 2.0 to 2.3.The relative error value between the calculation result and the experimental test result is from 0.58%to 14.07%.This research lay a theoretical foundation for the correction theory of the core elements of the spindle barrel finishing process.
基金National Basic Research Program of China(973 Program),No.2019YFB1311505National Natural Science Foundation of China,No.81773135 and No.82073192and Health Cultivating Foundation for Capital Citizens,No.Z171100000417023.
文摘The potential survival benefit of neoadjuvant chemotherapy(NC)in patients with advanced gastric cancer has been widely recognized.With the development of minimally invasive surgery,which is represented by laparoscopy,the effect of NC on the safety of laparoscopic gastrectomy remains to be further explored.AIM To compare the short-term outcomes of laparoscopic total gastrectomy(LTG)after NC(NC-LTG)with LTG alone.METHODS A total of 92 patients who underwent NC-LTG and 381 patients who received LTG alone at the Chinese PLA General Hospital between September 2015 and September 2020 were retrospectively included in our study.We used propensityscore matching(PSM)to balance baseline bias.After 1:1 PSM,73 patients were included in each group with no statistically significant difference in baseline characteristics.RESULTS The NC-LTG group exhibited a longer operation time(244.10±48.13 min vs 225.74±45.33 min,P=0.019)and increased intraoperative blood loss[150(100-300)mL vs 100(100-200)mL,P=0.011]compared to the LTG group.The 30-d postoperative morbidity of the NC-LTG group was 20.5%(15/73),and that of the LTG group was 13.7%(10/73).There were no significant differences in 30-d severe complication rates or anastomotic leakage rates.Subgroup analysis showed that the patients with pTNM(pathological tumor-node-metastasis classification)T0N0-II in the NC-LTG group underwent a longer operation than the LTG group,while no significant difference was found in any perioperative index for the pTNM III patients.A multivariate analysis showed that an operation time longer than 240 min was an independent risk factor(odds ratio=3.021,95%confidence interval:1.160-7.868,P=0.024),while NC was not an independent risk factor for postoperative complications in LTG.CONCLUSION Despite a longer operation time and more blood loss after NC-LTG,which indicate surgical difficulty,NC-LTG exhibits acceptable short-term outcomes compared to LTG,suggesting the safety and feasibility of NC-LTG.
文摘In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure.
基金funded by the National Basic Research Program of China(2019YFB1311505)the National Natural Science Foundation of China(82073192,81773135)。
文摘Background: Traumatic colon injury(TCI) is a common disease during wartime. Prolongation of posttraumatic survival time is an effective approach to patient outcome improvement. However, there is a lack of basic research in this field.This study aimed to elucidate the mechanisms underlying TCI progression and to develop novel regimens to buy time for TCI patients on the battlefield.Methods: A total of 669 Sprague–Dawley rats were used in this study. Surgical colon incision was performed to generate the TCI rat model. The landscape of colon microbiota compositions was depicted using 16S rRNA sequencing and metabolites in the intestinal contents were detected by metabolomics profiling. The signaling transduction in the intestinal epithelium was investigated using antibody microarrays and Western blotting. The enzyme-linked immunosorbent assay(ELISA) was conducted to measure the levels of interleukin-6 and tumor necrosis factor-α in intestines and plasma for the detection of inflammatory responses. Diamine oxidase, D-lactate and endotoxin in plasma and protein expression of zonula occludens 1 and occludin were selected as the indicators of intestinal barrier permeability. To investigate alterations of microbiota symbiosis, the relative abundances of specific bacterial genera were detected using quantitative real-time PCR(qRT-PCR).Results: As a type of lethal injury, TCI induced acute disruption of intestinal homeostasis, characterized by inflammatory responses, intestinal barrier hyperpermeability and microbiota dysbiosis(P<0.05). Significant alterations in bacterial metabolic patterns were detected with decreases in many metabolites. After a series of screenings,we found that oral administration of asparagine(Asn) and 3-indolepropionic acid(IPA) effectively prolonged posttraumatic survival time [Asn plus IPA vs. Vehicle: hazard ratio(HR)=0.105, 95%CI 0.031–0.356, P=0.0003] and restored intestinal homeostasis in TCI rats(P<0.05). Mechanistically, this combinational strategy protected the rats against TCI through synergistic activation of Akt signaling in the intestinal epithelium(P<0.05).Conclusions: Abrupt dysregulation of intestinal homeostasis plays a critical role in the progression toward TCI induced death. Oral administration of Asn plus IPA may serve as an effective regimen to restore intestinal functions and prolong the posttraumatic survival time.
基金financially supported by the National Key R&D Program of China(2016YFB0700600)the Soft Science Research Project of Guangdong Province(No.2017B030301013)the Shenzhen Science and Technology Research Grant(ZDSYS201707281026184)。
文摘Li and Mn rich(LMR)layered oxides,written as xLi_(2) MnO_(3)·(1-x)LiMO_(2)(M=Mn,Ni,Co,Fe,etc.),have been widely reported in recent years due to their high capacity and high energy density.The stable structure and superior performance of LMR oxides make them one of the most promising candidates for the next-generation cathode materials.However,the commercialization of these materials is hindered by several drawbacks,such as low initial Coulombic efficiency,the degradation of voltage and capacity during cycling,and poor rate performance.This review summarizes research progress in solving these concerns of LMR cathodes over the past decade by following three classes of strategies:morphology design,bulk design,and surface modification.We elaborate on the processing procedures,electrochemical performance,mechanisms,and limitations of each approach,and finally put forward the concerns left and the possible solutions for the commercialization of LMR cathodes.
文摘Objective: The aim of the study was to observe the clinical efficacy with Yiqi Jianpi decoction combination with FOLFOX4 for the postoperative patients of colorectal cancer (CRC). Methods: Eighty-five patients were randomly divided into two groups. The treated group (n = 41) received Yiqi Jianpi decoction combined with FOLFOX4 chemotherapy and the control group (n = 44) received FLOFOX4 chemotherapy alone. A treatment course of 6 months was applied to both groups. Results: The life quality, symptomatic improvement and adverse side effects reducing in the treated group were better than those of the control group. Conclusion: Yiqi Jianpi decoction combination with FOLFOX4 chemotherapy is effective in the treatment of the postoperative patients with colorectal cancer.
基金Supported by National Basic Research Program of China (973 Program),No. 2019YFB1311505National Natural Science Foundation of China,No. 81773135 and No. 82073192
文摘BACKGROUND Neoadjuvant chemotherapy(NACT)combined with surgery is regarded as an effective treatment for advanced gastric cancer(AGC).Laparoscopic surgery represents the mainstream of minimally invasive surgery.Currently,surgeons focus more on surgical safety and oncological outcomes of laparoscopic gastrectomy after NACT.Thus,we sought to evaluate short-and long-term outcomes between laparoscopic total gastrectomy(LTG)and open total gastrectomy(OTG)after NACT.AIM To compare the short and long-term outcomes between LTG and OTG for AGC after NACT.METHODS We retrospectively collected the clinicopathological data of 136 patients who accepted gastrectomy after NACT from June 2012 to June 2019,including 61 patients who underwent LTG and 75 who underwent OTG.Clinicopathological characteristics between the LTG and OTG groups showed no significant difference.SPSS 26.0,R software,and GraphPad PRISM 8.0 were used to perform statistical analyses.RESULTS Of the 136 patients included,eight acquired pathological complete response,and the objective response rate was 47.8%(65/136).The LTG group had longer operation time(P=0.015),less blood loss(P=0.003),shorter days to first flatus(P<0.001),and shorter postoperative hospitalization days(P<0.001).LTG spent more surgical cost than OTG(P<0.001),while total hospitalized cost of LTG was less than OTG(P<0.001).21(28.0%)patients in the OTG group and 14(23.0%)in the LTG group had 30-d postoperative complications,but there was no significant difference between the two groups(P=0.503).The 3-year overall survival(OS)rate was 60.6%and 64.6%in the LTG and OTG groups,respectively[hazard ratio(HR)=0.859,95%confidence interval(CI):0.522-1.412,P=0.546],while the 3-year disease-free survival(DFS)rate was 54.5%and 51.8%in the LTG and OTG group,respectively(HR=0.947,95%CI:0.582-1.539,P=0.823).Multivariate cox analysis showed that body mass index and pTNM stage were independent risk factors for OS while vascular invasion and pTNM stage were independent risk factors for DFS(P<0.05).CONCLUSION After NACT,LTG shows comparable 30-d postoperative morbidity as well as 3-year OS and DFS rate to OTG.We recommend that experienced surgeons select LTG other than OTG for proper AGC patients after NACT.