期刊文献+
共找到63篇文章
< 1 2 4 >
每页显示 20 50 100
Comprehensive analysis of the gut microbiome and posttranslational modifications elucidates the route involved in microbiota-host interactions 被引量:1
1
作者 Hai-Yang Wang Lan-Xiang Liu +8 位作者 Xue-Yi Chen Yang-Dong Zhang Wen-Xia Li Wen-Wen Li Lian Wang Xiao-Long Mo Hong Wei Ping Ji peng xie 《Zoological Research》 SCIE CSCD 2024年第1期95-107,共13页
The gut microbiome interacts with the host to maintain body homeostasis,with gut microbial dysbiosis implicated in many diseases.However,the underlying mechanisms of gut microbe regulation of host behavior and brain f... The gut microbiome interacts with the host to maintain body homeostasis,with gut microbial dysbiosis implicated in many diseases.However,the underlying mechanisms of gut microbe regulation of host behavior and brain functions remain unclear.This study aimed to elucidate the influence of gut microbiota on brain functions via post-translational modification mechanisms in the presence or absence of bacteria without any stimulation.We conducted succinylome analysis of hippocampal proteins in germ-free(GF)and specific pathogen-free(SPF)mice and metagenomic analysis of feces from SPF mice.These results were integrated with previously reported hippocampal acetylome and phosphorylome data from the same batch of mice.Subsequent bioinformatics analyses revealed 584 succinylation sites on 455 proteins,including 54 up-regulated succinylation sites on 91 proteins and 99 down-regulated sites on 51 proteins in the GF mice compared to the SPF mice.We constructed a panoramic map of gut microbiota-regulated succinylation,acetylation,and phosphorylation,and identified cross-talk and relative independence between the different types of post-translational modifications in modulating complicated intracellular pathways.Pearson correlation analysis indicated that 13 taxa,predominantly belonging to the Bacteroidetes phylum,were correlated with the biological functions of post-translational modifications.Positive correlations between these taxa and succinylation and negative correlations between these taxa and acetylation were identified in the modulation of intracellular pathways.This study highlights the hippocampal physiological changes induced by the absence of gut microbiota,and proteomic quantification of succinylation,phosphorylation,and acetylation,contributing to our understanding of the role of the gut microbiome in brain function and behavioral phenotypes. 展开更多
关键词 Gut microbiota Hippocampal protein Post-translational modifications SUCCINYLATION ACETYLATION PHOSPHORYLATION
下载PDF
Task Offloading and Trajectory Optimization in UAV Networks:A Deep Reinforcement Learning Method Based on SAC and A-Star
2
作者 Jianhua Liu peng xie +1 位作者 Jiajia Liu Xiaoguang Tu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第11期1243-1273,共31页
In mobile edge computing,unmanned aerial vehicles(UAVs)equipped with computing servers have emerged as a promising solution due to their exceptional attributes of high mobility,flexibility,rapid deployment,and terrain... In mobile edge computing,unmanned aerial vehicles(UAVs)equipped with computing servers have emerged as a promising solution due to their exceptional attributes of high mobility,flexibility,rapid deployment,and terrain agnosticism.These attributes enable UAVs to reach designated areas,thereby addressing temporary computing swiftly in scenarios where ground-based servers are overloaded or unavailable.However,the inherent broadcast nature of line-of-sight transmission methods employed by UAVs renders them vulnerable to eavesdropping attacks.Meanwhile,there are often obstacles that affect flight safety in real UAV operation areas,and collisions between UAVs may also occur.To solve these problems,we propose an innovative A*SAC deep reinforcement learning algorithm,which seamlessly integrates the benefits of Soft Actor-Critic(SAC)and A*(A-Star)algorithms.This algorithm jointly optimizes the hovering position and task offloading proportion of the UAV through a task offloading function.Furthermore,our algorithm incorporates a path-planning function that identifies the most energy-efficient route for the UAV to reach its optimal hovering point.This approach not only reduces the flight energy consumption of the UAV but also lowers overall energy consumption,thereby optimizing system-level energy efficiency.Extensive simulation results demonstrate that,compared to other algorithms,our approach achieves superior system benefits.Specifically,it exhibits an average improvement of 13.18%in terms of different computing task sizes,25.61%higher on average in terms of the power of electromagnetic wave interference intrusion into UAVs emitted by different auxiliary UAVs,and 35.78%higher on average in terms of the maximum computing frequency of different auxiliary UAVs.As for path planning,the simulation results indicate that our algorithm is capable of determining the optimal collision-avoidance path for each auxiliary UAV,enabling them to safely reach their designated endpoints in diverse obstacle-ridden environments. 展开更多
关键词 Mobile edge computing SAC communication security A-Star UAV
下载PDF
Solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study
3
作者 Zijiang Dou Weiqiang Tang +1 位作者 peng xie Shuangliang Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期180-188,共9页
Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and selectivity.However... Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and selectivity.However,the underlying microscopic mechanism remains ambiguous.In this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or acrylonitrile.By analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy decrease.In addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions. 展开更多
关键词 Solvent effect Ionic liquids Diels-Alder reaction Reaction density functional theory
下载PDF
LncRNA NPTN-IT1-201 Ameliorates Depressive-like Behavior by Targeting miR-142-5p and Regulating Inflammation and Apoptosis via BDNF
4
作者 Jun HE peng xie +6 位作者 Xiao-qiong AN Dong-fen GUO Bin BI Gang WU Wen-feng YU Zhen-kui REN Li ZUO 《Current Medical Science》 SCIE CAS 2024年第5期971-986,共16页
Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mec... Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mechanisms in major depressive disorder(MDD)remain largely unknown.This study aimed to identify lncRNAs and miRNAs involved in the development of MDD and elucidate their molecular mechanisms.Methods Transcriptome and bioinformatic analyses were performed to identify miRNAs and lncRNAs related to MDD.C57 mice were subjected to chronic unpredictable mild stress(CUMS)to establish a depression model.Lentiviruses containing either lncRNA NPTN-IT1-201 or miR-142-5p were microinjected into the hippocampal region of these mice.Behavioral tests including the sucrose preference test(SPT),tail suspension test(TST),and forced swim test(FST)were conducted to evaluate depressive-like behaviors.Results The results revealed that overexpression of lncRNA NPTN-IT1-201 or inhibition of miR-142-5p significantly ameliorated depressive-like behaviors in CUMS-treated mice.Dual-luciferase reporter assays confirmed interactions between miR-142-5p with both brain-derived neurotrophic factor(BDNF)and NPTN-IT1-201.ELISA analysis revealed significant alterations in relevant biomarkers in the blood samples of MDD patients compared to healthy controls.Histological analyses,including HE and Nissl staining,showed marked structural changes in brain tissues following CUMS treatment,which were partially reversed by lncRNA NPTN-IT1-201 overexpression or miR-142-5p inhibition.Immunofluorescence imaging demonstrated significant differences in the levels of BAX,Bcl2,p65,Iba1 among different treatment groups.TUNEL assays confirmed reduced apoptosis in brain tissues following these interventions.Western blotting showed the significant differences in BDNF,BAX,and Bcl2 protein levels among different treatment groups.Conclusion NPTN-IT1-201 regulates inflammation and apoptosis in MDD by targeting BDNF via miR-142-5p,making it a potential therapeutic target for MDD. 展开更多
关键词 depressive-like behavior chronic unpredictable mild stress long noncoding RNA microRNA brain-derived neurotrophic factor
下载PDF
Effect of low concentration electrolytes on the formation and corrosion resistance of PEO coatings on AM50 magnesium alloy
5
作者 peng xie Carsten Blawert +4 位作者 Maria Serdechnova Natalia Konchakova Tatsiana Shulha Ting Wu Mikhail L.Zheludkevich 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1386-1405,共20页
In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were system... In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate. 展开更多
关键词 Plasma electrolytic oxidation Low concentration electrolytes Corrosion resistance AM50 magnesium alloy
下载PDF
Analysis of Polymer Impurities in Cephalosporin Antibiotics
6
作者 Shiqiang OU Yanxi LAI +6 位作者 peng xie Hao LIU Shicheng LIU Jin QIN Yiping QIN Yizhang WANG Shengjiu GU 《Medicinal Plant》 2024年第5期22-26,30,共6页
[Objectives]To establish a HPLC-MS method for the determination of polymer impurities in cefathiamidine and its preparations.[Methods]Kromasil 100-5 C_(18) column(4.6 mm ×250 mm,5μm)was used for analysis;mobile ... [Objectives]To establish a HPLC-MS method for the determination of polymer impurities in cefathiamidine and its preparations.[Methods]Kromasil 100-5 C_(18) column(4.6 mm ×250 mm,5μm)was used for analysis;mobile phase ammonium acetate solution(pH 6.30)-acetonitrile,gradient elution;volumetric flow rate 1.0 mL/min;column temperature 40℃;multi-reaction monitoring mode was used for analysis,and positive ion scanning was chosen as the electrospray ion source.[Results]The resolution between impurities and main peaks under this method was greater than 1.5,and 8 known impurities and 2 polymer impurities could be completely separated and distinguish-ed.It was inferred that the molecular ion peak[M+H]^(+):m/z727.1874,m/z 785.1937 was the possible polymer impurity of this product.[Conclusions]A method for the analysis of polymer impurities in cefathiamidine and its preparations was formed,which could achieve the purpose of simultaneous analysis of small molecule impurities and polymer impurities,and could better control the content of single impurities in the polymer,providing a reliable inspection basis for strict control of cefathiamidine quality. 展开更多
关键词 CEFATHIAMIDINE Cephalosporin polymer impurities Impurity analysis High Performance Liquid Chromatography-Mass Spectrometry
下载PDF
Method for Improving the Determination of Dibromoacetic Acid in Cefathiamidine
7
作者 peng xie Hao LIU +6 位作者 Shiqiang OU Yanxi LAI Shicheng LIU Jin QIN Yiping QIN Xian CHEN Kaimei ZHU 《Medicinal Plant》 2024年第5期27-30,共4页
[Objectives]To establish an LC-MS method for the determination of dibromoacetic acid in Cefathiamidine and Cefathiamidine for Injection.[Methods]Shiseido PC HILIC column(2.0 mm ×100 mm,3μ.m)was used.The mobile p... [Objectives]To establish an LC-MS method for the determination of dibromoacetic acid in Cefathiamidine and Cefathiamidine for Injection.[Methods]Shiseido PC HILIC column(2.0 mm ×100 mm,3μ.m)was used.The mobile phase was 0.005 Mammonium formate and the mobile phase was acetonitrile with gradient elution.The flow rate was 0.3-0.8mL/min.[Results]The limit of detection was 0.2500 ng/mL and the limit of quantification was 0.500 ng/mL,which were 2.5%and 5.0%of the impurity limits,respectively.The recov-ery rate was 103.85%.[Conclusions]This method improved the detection of dibromoacetic acid impurities in Cefathiamidine,and has that advantage of good specificity,low limit of detection and limit of quantification,high sensitivity,high accuracy,interference resistance,can meet the detection requirements of Cefathiamidine,and is suitable for the quality control of Cefathiamidine. 展开更多
关键词 CEFATHIAMIDINE Dibromoacetic acid impurities LC-MS
下载PDF
Occult pancreaticobiliary reflux is a pathogenic factor of some benign biliary diseases and gallbladder cancer 被引量:3
8
作者 Lu Wang Zhi-Wei Zhang +3 位作者 Tong Guo peng xie Xiao-Rui Huang Ya-Hong Yu 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2023年第3期288-293,共6页
Background:Pancreaticobiliary maljunction(PBM)is a well-known high-risk factor for biliary malignant tumors because of constant pancreaticobiliary reflux(PBR).However,the impact of occult pancreaticobiliary reflux(OPR... Background:Pancreaticobiliary maljunction(PBM)is a well-known high-risk factor for biliary malignant tumors because of constant pancreaticobiliary reflux(PBR).However,the impact of occult pancreaticobiliary reflux(OPR),which is characterized by high bile amylase levels in individuals with anatomically normal pancreaticobiliary junction,on biliary diseases remains unclear.The aim of this study was to assess the correlation between OPR and biliary diseases.Methods:We enrolled 94 consecutive patients with normal pancreaticobiliary junction and primary biliary diseases confirmed by magnetic resonance cholangiopancreatography.We prospectively collected patients’bile samples and measured bile amylase levels.We investigated the incidence of OPR and the difference in bile amylase levels among these patients and assessed the correlation between high bile amylase levels(HBAL)and benign or malignant biliary diseases,as well as the OPR risk factors.Results:The incidence of OPR was 36.6%in patients with benign biliary diseases,26.7%in those with cholangiocarcinoma and 62.5%in those with gallbladder cancer.The median bile amylase level tended to be higher in patients with gallbladder cancer than in those with benign biliary diseases,but there was no significant difference(165.5 IU/L vs.23.0 IU/L,P=0.212).The prevalence of an HBAL with bile amylase levels of 1000-7500 IU/L was similar in patients with gallbladder cancer and benign biliary diseases.However,the incidence of HBAL with bile amylase levels greater than 7500 IU/L was significantly higher in patients with gallbladder cancer than in those with benign biliary diseases(37.5%vs.4.2%,P=0.012).Multivariate logistic regression analysis revealed that choledocholithiasis was an independent risk factor for OPR.Conclusions:OPR can occur in benign and malignant biliary diseases,and it may be a pathogenic factor for some benign biliary diseases and a high-risk factor for gallbladder cancer.There is a correlation between choledocholithiasis and OPR. 展开更多
关键词 Occult pancreaticobiliary reflux Biliary diseases Bile amylase Pancreaticobiliary junction Gallbladder cancer
下载PDF
Mid-term outcomes of left subclavian artery revascularization with Castor stent graft in treatment of type B aortic dissection in left subclavian artery 被引量:3
9
作者 Yu Tian Chengjie Wang peng xie 《Journal of Interventional Medicine》 2023年第2期74-80,共7页
Background:Here we analyzed mid-term data of thoracic endovascular aneurysm repair(TEVAR)surgery with Castor single-branched stent graft placement for the management of Stanford type B aortic dissection(STBAD)involvin... Background:Here we analyzed mid-term data of thoracic endovascular aneurysm repair(TEVAR)surgery with Castor single-branched stent graft placement for the management of Stanford type B aortic dissection(STBAD)involving the left subclavian artery(LSA).Methods:Between April 2014 and February 2019,32 patients with STBAD involving a Castor single-branched stent graft were included.We analyzed their outcomes,including technical success rate(TSR),surgical duration(SD),presence of ischemia,perioperative complications,LSA patency,and survival rate(SR),using computed tomography angiography and clinical evaluation during mid-term follow-up.Results:The mean patient age was 54.63±12.37 years(range,36–83 years).The TSR was 96.88%(n=31/32).The mean SD was 87.44±10.89 with a mean contrast volume of 125.31±19.30 mL.No neurological complications or deaths occurred during the study period.The patients had a mean hospital stay of 7.84±3.20 days.At a mean follow-up of 68.78±11.26 months,four non-aortic deaths(12.5%)were observed.The LSA patency rate was 100%(n=28/28).There was only one case of type I endoleak immediately after surgery(3.12%)(type I from LSA).However,none of the patients experienced type II endoleaks,and there were no cases of retrograde type A aortic dissection or stent graft-driven new distal entry.Finally,all patients exhibited good LSA patency.Conclusion:TEVAR using a Castor single-branched stent graft may be a highly feasible and efficient procedure for the management of STBAD involving the LSA. 展开更多
关键词 Aortic dissection Endovascular treatment Branched stent-graft Left subclavian artery
下载PDF
Flat soliton microcomb source 被引量:2
10
作者 Xinyu Wang Xuke Qiu +6 位作者 Mulong Liu Feng Liu Mengmeng Li Linpei Xue Bohan Chen Mingran Zhang peng xie 《Opto-Electronic Science》 2023年第12期9-15,共7页
Mode-locked microcombs with flat spectral profiles provide the high signal-to-noise ratio and are in high demand for wavelength division multiplexing(WDM)-based applications,particularly in future high-capacity commun... Mode-locked microcombs with flat spectral profiles provide the high signal-to-noise ratio and are in high demand for wavelength division multiplexing(WDM)-based applications,particularly in future high-capacity communication and parallel optical computing.Here,we present two solutions to generate local relatively flat spectral profiles.One microcavity with ultra-flat integrated dispersion is pumped to generate one relatively flat single soliton source spanning over 150 nm.Besides,one extraordinary soliton crystal with single vacancy demonstrates the local relatively flat microcomb lines when the inner soliton spacings are slightly irregular.Our work paves a new way for soliton-based applications owing to the relatively flat spectral characteristics. 展开更多
关键词 ultra-flat integrated dispersion flat spectral profile soliton microcomb
下载PDF
Application of SPAC method and electromagnetic wave CT in karst detection of Wuhan Metro Line 8
11
作者 peng xie Jinggang Li +3 位作者 Biao Wang Gang Wu Qiuliang Wang Song Lin 《Geodesy and Geodynamics》 EI CSCD 2023年第5期513-520,共8页
In recent years,karst construction projects in the built-up area of Wuhan(capital of Hubei Province,China)are increasing,and the karst geological disasters have aroused social concerns.The actual engineering projects ... In recent years,karst construction projects in the built-up area of Wuhan(capital of Hubei Province,China)are increasing,and the karst geological disasters have aroused social concerns.The actual engineering projects usually use shallow geophysical exploration methods to explore karst.This paper uses Spatial Auto-Correlation Method(SPAC)and electromagnetic Computerized Tomography(CT)to detect karst in urban built-up areas.Depending on the different physical properties of rock and soil,the SPAC method can better reveal the interface between soil and rock strata and the interface between soil layers.The electromagnetic CT method can identify strata according to the apparent absorption coefficient,which can better reveal the interface between soil and rock,the interface between the more intact and weathered rock.The SPAC method is mainly qualitative to measure the low-speed area,namely,the wrong geological body i.e.,karst cave,but also can detect the fracture zone or filling mode of karst cave,and at the same time,cannot use exploration holes or logging observation.The electromagnetic CT method can accurately detect the location and scale of the karst caves and has a higher accuracy detecting karst bands.In addition,exploration holes or well logging observations are also expected to be conducted,and their detection effect is greatly affected by lithology. 展开更多
关键词 SPAC Array type Electromagnetic wave CT method Karst detection
下载PDF
Neuro-11:a new questionnaire for the assessment of somatic symptom disorder in general hospitals
12
作者 Silin Zeng Yian Yu +15 位作者 Shan Lu Sirui Zhang Xiaolin Su Ge Dang Ying Liu Zhili Cai Siyan Chen Yitao He Xin Jiang Chanjuan Chen Lei Yuan peng xie Jianqing Shi Qingshan Geng Rafael H Llinas Yi Guo 《General Psychiatry》 CSCD 2023年第4期248-259,共12页
Background Somatic symptom disorder(SSD)commonly presents in general hospital settings,posing challenges for healthcare professionals lacking specialised psychiatric training.The Neuro-11 Neurosis Scale(Neuro-11)offer... Background Somatic symptom disorder(SSD)commonly presents in general hospital settings,posing challenges for healthcare professionals lacking specialised psychiatric training.The Neuro-11 Neurosis Scale(Neuro-11)offers promise in screening and evaluating psychosomatic symptoms,comprising 11 concise items across three dimensions:somatic symptoms,negative emotions and adverse events.Prior research has validated the scale’s reliability,validity and theoretical framework in somatoform disorders,indicating its potential as a valuable tool for SSD screening in general hospitals.Aims This study aimed to establish the reliability,validity and threshold of the Neuro-11 by comparing it with standard questionnaires commonly used in general hospitals for assessing SSD.Through this comparative analysis,we aimed to validate the effectiveness and precision of the Neuro-11,enhancing its utility in clinical settings.Methods Between November 2020 and December 2021,data were collected from 731 patients receiving outpatient and inpatient care at Shenzhen People’s Hospital in China for various physical discomforts.The patients completed multiple questionnaires,including the Neuro-11,Short Form 36 Health Survey,Patient Health Questionnaire 15 items,Hamilton Anxiety Scale and Hamilton Depression Scale.Psychiatry-trained clinicians conducted structured interviews and clinical examinations to establish a gold standard diagnosis of SSD.Results The Neuro-11 demonstrated strong content reliability and structural consistency,correlating significantly with internationally recognised and widely used questionnaires.Despite its brevity,the Neuro-11 exhibited significant correlations with other questionnaires.A test-retest analysis yielded a correlation coefficient of 1.00,Spearman-Brown coefficient of 0.64 and Cronbach’sαcoefficient of 0.72,indicating robust content reliability and internal consistency.Confirmatory factor analysis confirmed the validity of the three-dimensional structure(p<0.001,comparative fit index=0.94,Tucker-Lewis index=0.92,root mean square error of approximation=0.06,standardised root mean square residual=0.04).The threshold of the Neuro-11 is set at 10 points based on the maximum Youden’s index from the receiver operating characteristic curve analysis.In terms of diagnostic efficacy,the Neuro-11 has an area under the curve of 0.67. 展开更多
关键词 validity dimensions SPITE
下载PDF
Density Functional Theory Calculations on the Interstellar Formation of Biomolecules
13
作者 Qingli Liao Junzhi Wang +2 位作者 peng xie Enwei Liang Zhao Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第12期7-18,共12页
Density functional theory(DFT)is the most versatile electronic structure method used in quantum chemical calculations,and is increasingly applied in astrochemical research.This mini-review provides an overview of the ... Density functional theory(DFT)is the most versatile electronic structure method used in quantum chemical calculations,and is increasingly applied in astrochemical research.This mini-review provides an overview of the applications of DFT calculations in understanding the chemistry that occurs in star-forming regions.We survey investigations into the formation of biologically relevant compounds such as nucleobases in the interstellar medium,and also cover the formation of both achiral and chiral amino acids,as well as biologically relevant molecules such as sugars,and nitrogen-containing polycyclic aromatic hydrocarbons.Additionally,DFT calculations are used to estimate the potential barriers for chemical reactions in astronomical environments.We conclude by noting several areas that require more research,such as the formation pathways of chiral amino acids,complex sugars,and other biologically important molecules,and the role of environmental factors in the formation of interstellar biomolecules. 展开更多
关键词 astrochemistry-molecular processes-methods LABORATORY molecular-astrobiology
下载PDF
Catalytic Role of H I in the Interstellar Synthesis of Complex Organic Molecule
14
作者 Shuming Yang peng xie +1 位作者 Enwei Liang Zhao Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第5期213-220,共8页
Using quantum chemical calculations,we model the pathways for synthesizing two purine nucleobases,adenine and guanine,in the gas-phase interstellar environment,surrounded by neutral atomic hydrogen(H I).H I is found a... Using quantum chemical calculations,we model the pathways for synthesizing two purine nucleobases,adenine and guanine,in the gas-phase interstellar environment,surrounded by neutral atomic hydrogen(H I).H I is found active in facilitating a series of fundamental proton transfer processes of organic synthesis,including bond formation,cyclization,dehydrogenation,and H migration.The reactive potential barriers were significantly reduced in the alternative pathways created by H I,leading to a remarkable increase in the reaction rate.The presence of H I also lowered the reactive activation temperature from 757.8 K to 131.5–147.0 K,indicating the thermodynamic feasibility of these pathways in star-forming regions where some of the reactants have been astronomically detected.Our findings suggest that H I may serve as an effective catalyst for interstellar organic synthesis. 展开更多
关键词 astrochemistry-astrobiology-ISM MOLECULES
下载PDF
极低蛋白日粮补充不同形式氮营养素对生长猪回肠食糜菌群、代谢产物和屏障功能的影响 被引量:10
15
作者 刘壮 慕春龙 +3 位作者 彭宇 彭燮 车炼强 朱伟云 《南京农业大学学报》 CAS CSCD 北大核心 2019年第3期526-534,共9页
[目的]本试验旨在研究极低蛋白(ELP)日粮下,补充不同形式氮营养素(氨基酸或酪蛋白)对生长猪回肠微生物、代谢产物和屏障功能的影响。[方法]试验选用80头PIC阉公猪(体质量约15.57 kg,48日龄),随机分为4组:中等蛋白组(MP)、低蛋白组(LP)... [目的]本试验旨在研究极低蛋白(ELP)日粮下,补充不同形式氮营养素(氨基酸或酪蛋白)对生长猪回肠微生物、代谢产物和屏障功能的影响。[方法]试验选用80头PIC阉公猪(体质量约15.57 kg,48日龄),随机分为4组:中等蛋白组(MP)、低蛋白组(LP)、极低蛋白+氨基酸组(ELP-AA)和极低蛋白+酪蛋白组(ELP-CAS),日粮粗蛋白(CP)水平分别为17%、15%、13%和13%。每个处理5个重复,每个重复4头仔猪。试验期28 d。MP和LP两组添加必需氨基酸(AA),ELP-AA组添加非必需AA以达到LP组日粮水平,ELP-CAS组使用3%酪蛋白部分替代ELP-AA组的单体AA,使其满足营养需要。于第29天每个重复挑选1头接近栏平均体质量的猪屠宰,采集回肠食糜和肠道组织样品,用于各项指标测定。[结果]与MP组相比,ELP-AA组回肠食糜中双歧杆菌属(Bifidobacterium)、乳酸杆菌属(Lactobacillus)和消化链球菌属(Peptostreptococcus)的数量显著降低(P<0.05),短链脂肪酸、氨态氮和生物胺的含量均显著下降(P<0.05),而补充酪蛋白后,乙酸、丁酸、氨态氮、腐胺和精胺的含量得到显著恢复(P<0.05)。基因表达方面,与LP组相比,ELP-AA组部分肠道屏障功能相关基因(MUC-1、MUC-2和Occludin)的表达量均显著下调(P<0.05),而MUC-1和Occludin的表达量在ELP-CAS组和MP或LP组之间无显著差异(P>0.05)。相关性分析结果表明,Lactobacillus数量与丁酸和生物胺含量、MUC-1、MUC-2和Occludin基因表达量显著正相关。[结论]饲喂极低蛋白日粮补充单体氨基酸对回肠微生物数量、代谢以及肠道组织屏障均产生不利影响,而补充酪蛋白能部分改善回肠有益微生物的生长并恢复部分肠道屏障相关基因的表达,提示在极低蛋白质水平下,补充酪蛋白对维持机体正常氮利用、肠道微生物生长代谢和肠道屏障功能具有重要作用。 展开更多
关键词 蛋白水平 氮营养素 肠道微生物 屏障功能
下载PDF
妊娠母猪营养研究进展 被引量:6
16
作者 吴德 方正锋 +4 位作者 车炼强 徐盛玉 卓勇 钟和局 彭燮 《饲料工业》 北大核心 2019年第10期60-64,共5页
中国规模化猪场母猪年提供的断奶仔猪数(PSY)及产肉量比欧美发达国家低30%~40%,究其原因在于品种选育、营养与饲养管理、疾病防控等各环节的不足。妊娠母猪的受胎率、早期胚胎存活、胎儿的生长发育受到营养及饲养管理的显著影响,是决... 中国规模化猪场母猪年提供的断奶仔猪数(PSY)及产肉量比欧美发达国家低30%~40%,究其原因在于品种选育、营养与饲养管理、疾病防控等各环节的不足。妊娠母猪的受胎率、早期胚胎存活、胎儿的生长发育受到营养及饲养管理的显著影响,是决定母猪繁殖效率的关键原因。国际国内考察营养对妊娠母猪繁殖性能的影响所涉及的营养素以能量、氨基酸、功能性添加物为主,而维生素、微量元素方面的研究较少。本文重点综述了近年来营养对妊娠母猪繁殖力的调控效应,为养猪生产者制定合理的营养与饲养管理程序提供参考。 展开更多
关键词 妊娠母猪 繁殖力 营养 饲养管理
下载PDF
Changes in synapse quantity and growth associated protein 43 expression in the motor cortex of focal cerebral ischemic rats following catalpol treatment 被引量:10
17
作者 Dong Wan Huifeng Zhu +1 位作者 Yong Luo peng xie 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第18期1380-1385,共6页
The present study investigated the effects of catalpol, the main constituent of the Chinese herb Rehmannia root, on neurons following brain ischemia, A rat model of focal permanent brain ischemia was established using... The present study investigated the effects of catalpol, the main constituent of the Chinese herb Rehmannia root, on neurons following brain ischemia, A rat model of focal permanent brain ischemia was established using electrocoagulation, The rats were intrapedtoneally injected with catalpol, at a dose of 5 mg/kg, daily for 1 week, Results showed that the number of neuronal synapses in the motor cortex and growth associated protein 43 expression were increased following catalpol treatment, indicating that catalpol might contribute to neuroplasticity and ameliorate functional neurological deficits induced by cerebral ischemia. 展开更多
关键词 CATALPOL growth-associated protein 4:3 neurological function permanent middle cerebral artery occlusion behavioral assessment neurological deficit NEUROPLASTICITY neural regeneration
下载PDF
Re–Os dating of molybdenite and in-situ Pb isotopes of sulfides from the Lamo Zn–Cu deposit in the Dachang tin-polymetallic ore field, Guangxi, China 被引量:11
18
作者 Hai Zhao Wenchao Su +5 位作者 peng xie Nengping Shen Jiali Cai Ming Luo Jie Li Zhian Bao 《Acta Geochimica》 EI CAS CSCD 2018年第3期384-394,共11页
The Dachang tin-polymetallic district, Guangxi,China, is one of the largest tin ore fields in the world. Both cassiterite-sulfide and Zn–Cu skarn mineralization are hosted in the Mid-Upper Devonian carbonate-rich sed... The Dachang tin-polymetallic district, Guangxi,China, is one of the largest tin ore fields in the world. Both cassiterite-sulfide and Zn–Cu skarn mineralization are hosted in the Mid-Upper Devonian carbonate-rich sediments adjacent to the underlying Cretaceous Longxianggai granite(91–97 Ma). The Lamo Zn–Cu deposit is a typical skarn deposit in the district and occurs at the contact zone between the Upper Devonian limestone and the granite.The ore minerals mainly consist of sphalerite, arsenopyrite,pyrrhotite, galena, chalcopyrite, and minor molybdenite.However, the age of mineralization and source of the metals are not well constrained. In this study, we use the molybdenite Re–Os dating method and in-situ Pb isotopes of sulfides from the Lamo deposit for the first time in order to directly determine the age of mineralization and the tracing source of metals. Six molybdenite samples yielded a more accurate Re–Os isochron age of 90.0 ± 1.1 Ma(MSWD = 0.72), which is much younger than the reported garnet Sm–Nd isochron age of 95 ± 11 Ma and quartz fluid inclusions Rb–Sr isochron age of 99 ± 6 Ma. This age is also interpreted as the age of Zn–Cu skarn mineralization in the Dachang district. Further, in this study we found that in-situ Pb isotopes of sulfides from the Lamo deposit and feldspars in the district's biotite granite and granitic porphyry dikes have a narrow range and an overlap of Pb isotopic compositions(^(206) Pb/^(204) Pb =18.417–18.594,^(207) Pb/^(204) Pb = 15.641–15.746, and^(208) Pb/^(204) Pb = 38.791–39.073), suggesting that the metals were mainly sourced from Cretaceous granitic magma. 展开更多
关键词 MOLYBDENITE Re-Os DATING IN-SITU leadisotopes SKARN DEPOSIT - DACHANG
下载PDF
B超引导腹横肌平面阻滞应用于老年患者腹腔镜直肠癌根治术后镇痛效果及对机体免疫功能的影响研究 被引量:19
19
作者 郭怡 谢澎 王鹏 《中国内镜杂志》 北大核心 2017年第10期76-82,共7页
目的观察B超引导腹横肌平面阻滞应用于老年患者腹腔镜直肠癌根治术后镇痛效果及对机体免疫功能的影响。方法60例需行腹腔镜直肠癌根治术的老年患者,按照入院顺序编号采取数字随机法分为腹横肌平面阻滞组及生理盐水对照组。腹横肌平面阻... 目的观察B超引导腹横肌平面阻滞应用于老年患者腹腔镜直肠癌根治术后镇痛效果及对机体免疫功能的影响。方法60例需行腹腔镜直肠癌根治术的老年患者,按照入院顺序编号采取数字随机法分为腹横肌平面阻滞组及生理盐水对照组。腹横肌平面阻滞组于全麻诱导后行B超引导腹横肌平面阻滞,静注0.25%盐酸罗哌卡因30 ml;生理盐水对照组静注等容量生理盐水。术后均给予静脉镇痛泵:舒芬太尼1.00μg/kg+昂丹司琼16.00 mg+地佐辛10.00 mg+生理盐水配置成100 ml,设置2 ml/h,自控时间15 min。观察两组麻醉前(T_0)、术后1 h(T_1)、术后12 h(T_2)、术后24 h(T_3)及术后48 h(T_4)的视觉模拟评分(VAS)及血流动力学相关指标;记录术后24 h镇痛泵按压次数及舒芬太尼使用总量;并抽取静脉血采取流式细胞仪测定CD4^+%、CD8^+%水平,应用酶联免疫吸附法测定γ干扰素(IFN-γ)水平;比较两组术后不良反应。结果与生理盐水对照组比较,腹横肌平面阻滞组于T_1和T_2时点平均动脉压(MAP)降低,T_1、T_2及T_3时点心率(HR)降低(均P<0.05);腹横肌平面阻滞组组内比较,T_1时点MAP高于T_0时点,T_1和T_2时点HR高于T_0时点(均P<0.05)。与生理盐水对照组比较,腹横肌平面阻滞组于T_1、T_2、T_3和T_4时点VAS评分均更低,且术后24 h按压次数及舒芬太尼总量均降低(均P<0.05),CD4^+%水平均升高,IFN-γ水平T_2和T_3时点均升高(均P<0.05);不良反应发生率降低(P<0.05)。结论B超引导腹横肌平面阻滞应用于老年患者腹腔镜直肠癌根治术后镇痛效果较佳,血流动力学平稳,术后疼痛程度更低,对机体免疫能力具有一定保护作用,且不良反应发生率低,临床应用安全。 展开更多
关键词 B超 腹横肌平面阻滞 腹腔镜 直肠癌根治术 老年 免疫功能
下载PDF
Chip-Based High-Dimensional Optical Neural Network 被引量:6
20
作者 Xinyu Wang peng xie +1 位作者 Bohan Chen Xingcai Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第12期570-578,共9页
Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems.Optical neural network(ONN)has the native advantages of high paralleliz... Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems.Optical neural network(ONN)has the native advantages of high parallelization,large bandwidth,and low power consumption to meet the demand of big data.Here,we demonstrate the dual-layer ONN with Mach-Zehnder interferometer(MZI)network and nonlinear layer,while the nonlinear activation function is achieved by optical-electronic signal conversion.Two frequency components from the microcomb source carrying digit datasets are simultaneously imposed and intelligently recognized through the ONN.We successfully achieve the digit classification of different frequency components by demultiplexing the output signal and testing power distribution.Efficient parallelization feasibility with wavelength division multiplexing is demonstrated in our high-dimensional ONN.This work provides a high-performance architecture for future parallel high-capacity optical analog computing. 展开更多
关键词 Integrated optics Optical neural network High-dimension Mach-Zehnder interferometer Nonlinear activation function Parallel high-capacity analog computing
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部