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Porcine enteric alphacoronavirus infection increases lipid droplet accumulation to facilitate the virus replication
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作者 qi gao Yongzhi Feng +7 位作者 Ting Gong Dongdong Wu Xiaoyu Zheng Yizhuo Luo Yunlong Yang Zebu Song Lang Gong Guihong Zhang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期988-1005,共18页
Coronaviruses are widely transmissible between humans and animals, causing diseases of varying severity. Porcine enteric alphacoronavirus(PEAV) is a newly-discovered pathogenic porcine enteric coronavirus in recent ye... Coronaviruses are widely transmissible between humans and animals, causing diseases of varying severity. Porcine enteric alphacoronavirus(PEAV) is a newly-discovered pathogenic porcine enteric coronavirus in recent years, which causes watery diarrhea in newborn piglets. The host inflammatory responses to PEAV and its metabolic regulation mechanisms remain unclear, and no antiviral studies have been reported. Therefore, we investigated the pathogenic mechanism and antiviral drugs of PEAV. The transcriptomic analysis of PEAV-infected host cells revealed that PEAV could upregulate lipid metabolism pathways. In lipid metabolism, steady-state energy processes, which can be mediated by lipid droplets(LDs), are the main functions of organelles. LDs are also important in viral infection and inflammation. In infected cells, PEAV increased LD accumulation, upregulated NF-κB signaling, promoted the production of the inflammatory cytokines IL-1β and IL-8, and induced cell death. Inhibiting LD accumulation with a DGAT-1 inhibitor significantly inhibited PEAV replication, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. The NF-κB signaling pathway inhibitor BAY11-7082 significantly inhibited LD accumulation and PEAV replication. Metformin hydrochloride also exerted anti-PEAV effects and significantly inhibited LD accumulation, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. LD accumulation in the lipid metabolism pathway therefore plays an important role in the replication and pathogenesis of PEAV, and metformin hydrochloride inhibits LD accumulation and the inflammatory response to exert anti-PEAV activity and reducing pathological injury. These findings contribute new targets for developing treatments for PEAV infections. 展开更多
关键词 porcine enteric alphacoronavirus NF-κB inflammatory pathway lipid droplet metformin hydrochloride
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Application of deep learning methods combined with physical background in wide field of view imaging atmospheric Cherenkov telescopes
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作者 Ao-Yan Cheng Hao Cai +25 位作者 Shi Chen Tian-Lu Chen Xiang Dong You-Liang Feng qi gao Quan-Bu Gou Yi-qing Guo Hong-Bo Hu Ming-Ming Kang Hai-Jin Li Chen Liu Mao-Yuan Liu Wei Liu Fang-Sheng Min Chu-Cheng Pan Bing-qiang qiao Xiang-Li qian Hui-Ying Sun Yu-Chang Sun Ao-Bo Wang Xu Wang Zhen Wang Guang-Guang Xin Yu-Hua Yao qiang Yuan Yi Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期208-220,共13页
The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of... The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of focused Cherenkov detectors.Its objective is to observe transient sources such as gamma-ray bursts and the counterparts of gravitational waves.This study aims to utilize the latest AI technology to enhance the sensitivity of HADAR experiments.Training datasets and models with distinctive creativity were constructed by incorporating the relevant physical theories for various applications.These models can determine the type,energy,and direction of the incident particles after careful design.We obtained a background identification accuracy of 98.6%,a relative energy reconstruction error of 10.0%,and an angular resolution of 0.22°in a test dataset at 10 TeV.These findings demonstrate the significant potential for enhancing the precision and dependability of detector data analysis in astrophysical research.By using deep learning techniques,the HADAR experiment’s observational sensitivity to the Crab Nebula has surpassed that of MAGIC and H.E.S.S.at energies below 0.5 TeV and remains competitive with conventional narrow-field Cherenkov telescopes at higher energies.In addition,our experiment offers a new approach for dealing with strongly connected,scattered data. 展开更多
关键词 VHE gamma-ray astronomy HADAR Deep learning Convolutional neural networks
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Thermally-induced cracking behaviors of coal reservoirs subjected to cryogenic liquid nitrogen shock
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作者 Songcai Han qi gao +5 位作者 Xinchuang Yan Lile Li Lei Wang Xian Shi Chuanliang Yan Daobing Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2894-2908,共15页
The benefits of using cryogenic liquid nitrogen shock to enhance coal permeability have been confirmed from experimental perspectives.In this paper,we develop a fully coupled thermo-elastic model in combination with t... The benefits of using cryogenic liquid nitrogen shock to enhance coal permeability have been confirmed from experimental perspectives.In this paper,we develop a fully coupled thermo-elastic model in combination with the strain-based isotropic damage theory to uncover the cooling-dominated cracking behaviors through three typical cases,i.e.coal reservoirs containing a wellbore,a primary fracture,and a natural fracture network,respectively.The progressive cracking processes,from thermal fracture initiation,propagation or cessation,deflection,bifurcation to multi-fracture interactions,can be well captured by the numerical model.It is observed that two hierarchical levels of thermal fractures are formed,in which the number of shorter thermal fractures consistently exceeds that of the longer ones.The effects of coal properties related to thermal stress levels and thermal diffusivity on the fracture morphology are quantified by the fracture fractal dimension and the statistical fracture number.The induced fracture morphology is most sensitive to changes in the elastic modulus and thermal expansion coefficient,both of which dominate the complexity of the fracture networks.Coal reservoir candidates with preferred thermal-mechanical properties are also recommended for improving the stimulation effect.Further findings are that there exists a critical injection temperature and a critical in-situ stress difference,above which no thermal fractures would be formed.Preexisting natural fractures with higher density and preferred orientations are also essential for the formation of complex fracture networks.The obtained results can provide some theoretical support for cryogenic fracturing design in coal reservoirs. 展开更多
关键词 Coal reservoirs Cryogenic shock Thermal cracking behaviors Fracture morphology
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Gamma/Hadron Separation Method for the HADAR Experiment
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作者 Yang-Zhao Ren Tian-Lu Chen +13 位作者 You-Liang Feng Dan-Zeng Luo-Bu Yi-qing Guo Cheng Liu qi gao Mao-Yuan Liu Xiang-Li qian Ya-Ping Wang Zi-Hao Zhang Xin-Long Li qing-Yuan Hou Heng-Jiao Liu qing-qian Zhou Shan-Jie Shu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期70-74,共5页
Ground-based arrays of imaging atmospheric Cherenkov telescopes(IACTs)are the most sensitiveγ-ray detectors for energies of approximately 100 Ge V and above.One such IACT is the High Altitude Detection of Astronomica... Ground-based arrays of imaging atmospheric Cherenkov telescopes(IACTs)are the most sensitiveγ-ray detectors for energies of approximately 100 Ge V and above.One such IACT is the High Altitude Detection of Astronomical Radiation(HADAR)experiment,which uses a large aperture refractive water lens system to capture atmospheric Cherenkov photons(i.e.,the imaging atmospheric Cherenkov technique).The telescope array has a low threshold energy and large field of view,and can continuously scan the area of the sky being observed,which is conducive to monitoring and promptly responding to transient phenomena.The process ofγ-hadron separation is essential in very-high-energy(>30 Ge V)γ-ray astronomy and is a key factor for the successful utilization of IACTs.In this study,Monte Carlo simulations were carried out to model the response of cosmic rays within the HADAR detectors.By analyzing the Hillas parameters and the distance between the event core and the telescope,the distinction between air showers initiated byγ-rays and those initiated by cosmic rays was determined.Additionally,a Quality Factor was introduced to assess the telescope’s ability to suppress the background and to provide a more effective characterization of its performance. 展开更多
关键词 astroparticle physics-telescopes-methods data analysis
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基坑开挖诱发侧方隧道变形的PCA-MLR预测方法
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作者 孙进 赵伏田 +2 位作者 王磊 祁高 单浩 《水利与建筑工程学报》 2024年第3期107-112,共6页
研究基坑开挖对侧方隧道变形的影响是岩土工程领域的热点与难点问题。为预测基坑开挖诱发临近侧方隧道变形,首先通过主成分分析方法(PCA)对侧方隧道变形指标影响因素进行降维处理并获取其主成分指标,然后采用多元线性回归方法(MLR)建立... 研究基坑开挖对侧方隧道变形的影响是岩土工程领域的热点与难点问题。为预测基坑开挖诱发临近侧方隧道变形,首先通过主成分分析方法(PCA)对侧方隧道变形指标影响因素进行降维处理并获取其主成分指标,然后采用多元线性回归方法(MLR)建立隧道变形指标与主成分指标间的关系模型,最后基于工程实例验证提出的PCA-MLR预测模型的正确性。研究结果表明:PCA-MLR模型考虑了基坑开挖诱发侧方隧道变形的高维度影响因素耦合作用,且实现了低维度主成分指标与变形指标间的关系模型建立。采用PCA-MLR模型预测的隧道最大水平及竖向位移与实测值的相对误差均小于10%,验证了提出模型的正确性与适用性。 展开更多
关键词 基坑开挖 侧方隧道 主成分分析 多元线性回归
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Erratum:"Gamma/Hadron Separation Method for the HADAR Experiment"(2024,RAA,24,035007)
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作者 Yang-Zhao Ren Tian-Lu Chen +13 位作者 You-Liang Feng Dan-Zeng Luo-Bu Yi-qing Guo Cheng Liu qi gao Mao-Yuan Liu Xiang-Li qian Ya-Ping Wang Zi-Hao Zhang Xin-Long Li qing-Yuan Hou Heng-Jiao Liu qing-qian Zhou Shan-Jie Shu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第7期273-273,共1页
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Classifying Globular Clusters and Applying them to Estimate the mass of the Milky Way
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作者 GuangChen Sun Yougang Wang +3 位作者 Chao Liu Richard J.Long Xuelei Chen qi gao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第1期127-152,共26页
We combine the kinematics of 159 globular clusters(GCs) provided by the Gaia Early Data Release 3(EDR3) with other observational data to classify the GCs,and to estimate the mass of the Milky Way(MW).We use the agemet... We combine the kinematics of 159 globular clusters(GCs) provided by the Gaia Early Data Release 3(EDR3) with other observational data to classify the GCs,and to estimate the mass of the Milky Way(MW).We use the agemetallicity relation,integrals of motion,action space and the GC orbits to identify the GCs as either formed in situ(Bulge and Disk) or ex situ(via accretion).We find that 45.3% have formed in situ,while 38.4% may be related to known merger events:Gaia-Sausage-Enceladus,the Sagittarius dwarf galaxy,the Helmi streams,the Sequoia galaxy and the Kraken galaxy.We also further identify three new sub-structures associated with the Gaia-Sausage-Enceladus.The remaining 16.3% of GCs are unrelated to the known mergers and thought to be from small accretion events.We select 46 GCs which have radii 8.0 <r<37.3 kpc and obtain the anisotropy parameter β=0.315_(-0.049)^(+0.055),which is lower than the recent result using the sample of GCs in Gaia Data Release 2,but still in agreement with it by considering the error bar.By using the same sample,we obtain the MW mass inside the outermost GC as M(<37.3 kpc)=0.423_(-0.02)^(+0.02)×10^(12)M_(⊙),and the corresponding M_(200)=1.11_(-0.18)^(+0.25)×10^(12)M_(⊙).The estimated mass is consistent with the results in many recent studies.We also find that the estimated β and mass depend on the selected sample of GCs.However,it is difficult to determine whether a GC fully traces the potential of the MW. 展开更多
关键词 GALAXY kinematics and dynamics-Galaxy fundamental parameters-Galaxy halo-(Galaxy:)globular clusters general
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The Masses of a Sample of Radial-velocity Exoplanets with Astrometric Measurements
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作者 Guang-Yao Xiao Yu-Juan Liu +6 位作者 Huan-Yu Teng Wei Wang Timothy D.Brandt Gang Zhao Fei Zhao Meng Zhai qi gao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第5期236-267,共32页
Being one of the most fundamental physical parameter of astronomical objects,mass plays a vital role in the study of exoplanets,including their temperature structure,chemical composition,formation,and evolution.Howeve... Being one of the most fundamental physical parameter of astronomical objects,mass plays a vital role in the study of exoplanets,including their temperature structure,chemical composition,formation,and evolution.However,nearly a quarter of the known confirmed exoplanets lack measurements of their masses.This is particularly severe for those discovered via the radial velocity(RV)technique,which alone could only yield the minimum mass of planets.In this study,we use published RV data combined with astrometric data from a cross-calibrated Hipparcos-Gaia Catalog of Accelerations to jointly constrain the masses of 115 RV-detected substellar companions,by conducting full orbital fits using the public tool orvara.Among them,9 exoplanets with M_(p)sini<13.5M_(Jup)are reclassified to the brown dwarf(BD)regime,and 16 BD candidates(13.5≤Mp sini<80M_(Jup))turn out to be low-mass M dwarfs.We point out the presence of a transition in the BD regime as seen in the distributions of host star metallicity and orbital eccentricity with respect to planet masses.We confirm the previous findings that companions with masses below 42.5 M_(Jup)might primarily form in the protoplanetary disk through core accretion or disk gravitational instability,while those with masses above 42.5 M_(Jup)formed through the gravitational instability of a molecular cloud like stars.Selection effects and detection biases,which may affect our analysis to some extent,are discussed. 展开更多
关键词 techniques radial velocities-astrometry--stars formation-catalogs
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The red/far-red light photoreceptor FvePhyB regulates tissue elongation and anthocyanin accumulation in woodland strawberry
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作者 qi gao Shaoqiang Hu +4 位作者 Xiaoli Wang Fu Han Huifeng Luo Zhongchi Liu Chunying Kang 《Horticulture Research》 SCIE CSCD 2023年第12期204-216,共13页
Light is an important environmental signal that influences plant growth and development.Among the photoreceptors,phytochromes can sense red/far-red light to coordinate various biological processes.However,their functi... Light is an important environmental signal that influences plant growth and development.Among the photoreceptors,phytochromes can sense red/far-red light to coordinate various biological processes.However,their functions in strawberry are not yet known.In this study,we identified an EMS mutant,named P8,in woodland strawberry(Fragaria vesca)that showed greatly increased plant height and reduced anthocyanin content.Mapping-by-sequencing revealed that the causal mutation in FvePhyB leads to premature termination of translation.The light treatment assay revealed that FvePhyB is a bona fide red/far-red light photoreceptor,as it specifically inhibits hypocotyl length under red light.Transcriptome analysis showed that the FvePhyB mutation affects the expression levels of genes involved in hormone synthesis and signaling and anthocyanin biosynthesis in petioles and fruits.The srl mutant with a longer internode is caused by a mutation in the DELLA gene FveRGA1(Repressor of GA1)in the gibberellin pathway.We found that the P8 srl double mutant has much longer internodes than srl,suggesting a synergistic role of FvePhyB and FveRGA1 in this process.Taken together,these results demonstrate the important role of FvePhyB in regulating plant architecture and anthocyanin content in woodland strawberry. 展开更多
关键词 STRAW PHYB light
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A description of ophthalmic management of late recovered facial paralysis with patient-tailored procedures:a case report
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作者 Hui-Na Zhang Jia-Jun Xie +1 位作者 qi gao Juan Ye 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第4期668-670,共3页
Dear Editor,We reported a case of a multidisciplinary therapy for late recovered facial paralysis 2y after the initial diagnosis.Facial paralysis has an incidence of 20-30 people out of 100000 per year,and up to 1 in ... Dear Editor,We reported a case of a multidisciplinary therapy for late recovered facial paralysis 2y after the initial diagnosis.Facial paralysis has an incidence of 20-30 people out of 100000 per year,and up to 1 in 60 people will be affected during their life time[1]. 展开更多
关键词 HAS PARALYSIS recovered
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夏垫断裂大胡庄探槽古地震事件分析 被引量:8
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作者 邓梅 沈军 +4 位作者 李西 祁高 戴训也 王昌盛 刘泽众 《地震研究》 CSCD 北大核心 2018年第2期293-301,共9页
夏垫断裂是北京平原区内1条极为重要的隐伏活动断裂,同时也是1679年三河—平谷MS8.0地震的发震断层。为获取该断裂完整的古地震序列,主要开展了2方面工作:(1)以大胡庄探槽原始资料为基础,重新对探槽进行了解译,共识别出3个埋藏古土壤,6... 夏垫断裂是北京平原区内1条极为重要的隐伏活动断裂,同时也是1679年三河—平谷MS8.0地震的发震断层。为获取该断裂完整的古地震序列,主要开展了2方面工作:(1)以大胡庄探槽原始资料为基础,重新对探槽进行了解译,共识别出3个埋藏古土壤,6个崩积楔和1次砂土液化现象;(2)结合该断裂其它部位探槽揭示的古地震事件,通过对比各探槽标志性地层,建立不同探槽中古地震事件在同一时间轴上的联系,得到夏垫断裂完整的古地震序列。结果表明:距今31 ka以来,夏垫断裂共发生过11次古地震事件,古地震平均复发间隔约为2.8ka,但距今25~15 ka存在1个古地震丛集期,丛集期内共发生5次强震,平均复发间隔约为2.0 ka,反映出夏垫断裂活动性存在阶段性的差异。 展开更多
关键词 夏垫断裂 古地震事件 崩积楔 砂土液化 标志性地层
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三乙烯二胺交联季铵化聚芳醚砜电解质膜的制备与性能 被引量:2
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作者 潘雪婷 高琪 +3 位作者 朱雨昕 宁丹 胡朝霞 陈守文 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2018年第10期122-128,共7页
采用聚芳醚砜为原料,经付克氯甲基化反应,以三乙烯二胺为交联剂,通过非均相和均相2种季铵化方式制备了2类燃料电池用交联型阴离子交换膜CQPAES。所制备CQPAES膜的离子交换容量为1. 15~1. 25 mmol/g。与非交联膜相比,交联膜的耐溶剂性... 采用聚芳醚砜为原料,经付克氯甲基化反应,以三乙烯二胺为交联剂,通过非均相和均相2种季铵化方式制备了2类燃料电池用交联型阴离子交换膜CQPAES。所制备CQPAES膜的离子交换容量为1. 15~1. 25 mmol/g。与非交联膜相比,交联膜的耐溶剂性、尺寸稳定性均得到了提高,在高温高压水中的水解稳定性、强碱条件下的化学稳定性显著增强。季铵化方式对交联膜性能影响的研究表明,均相季铵化膜与非均相季铵化膜相比,可更好地控制交联膜的溶胀,相应交联膜的离子电导率更高。交联剂加入量为0. 1~0. 2时,交联膜的综合性能最佳。 展开更多
关键词 燃料电池 阴离子交换膜 三乙烯二胺 季铵化聚芳醚砜 交联
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大气臭氧长期暴露对社区自然人群抑郁、焦虑和压力状况的影响 被引量:5
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作者 刘晓慧 曹寒 +11 位作者 张晗 王郑芳 汤乃军 牛凯军 刘括 祝慧萍 高琦 李冰潇 彭文娟 谢韵漪 单广良 张玲 《医学新知》 CAS 2021年第1期5-13,共9页
目的探讨大气污染物臭氧(O3)的长期暴露对社区人群抑郁、焦虑、压力状况的影响,为开展大气污染环境下人群心理健康干预工作提供科学依据。方法基于京津冀社区自然人群慢性病队列基线调查数据。使用问卷和抑郁-焦虑-压力量表(depression ... 目的探讨大气污染物臭氧(O3)的长期暴露对社区人群抑郁、焦虑、压力状况的影响,为开展大气污染环境下人群心理健康干预工作提供科学依据。方法基于京津冀社区自然人群慢性病队列基线调查数据。使用问卷和抑郁-焦虑-压力量表(depression anxiety stress scale 21,DASS-21)收集研究对象基本信息,以及抑郁、焦虑和压力状况。通过监测站收集污染物数据并进行暴露评估,采用多水平Logistic回归方法分析O3长期暴露与社区人群抑郁、焦虑和压力发生风险的关系。结果纳入13446例研究对象(48.50±14.87岁),抑郁、焦虑和压力症状的检出率分别为10.5%、16.6%和5.2%,O3的三年平均浓度为100.20μg/m3。多水平模型分析结果发现O3每增加10μg/m3,抑郁[OR=1.154,95%CI(1.086,1.227)]、焦虑[OR=1.093,95%CI(1.042,1.147)]和压力[OR=1.142,95%CI(1.056,1.235)]的发生风险均有增加。敏感性分析模型结果相对稳定,显示O3对抑郁、焦虑和压力发生风险具有独立影响作用。结论大气污染物O3可能是导致人群负性心理症状的危险因素之一,应重点关注O3高暴露地区人群的心理健康。 展开更多
关键词 大气污染物 臭氧 心理健康 DASS-21 抑郁 焦虑 压力
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Early intrajejunal nutrition: bacterial translocation and gut barrier function of severe acute pancreatitis in dogs 被引量:20
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作者 Huan-Long qin Zhen-Dong Su +1 位作者 qi gao qing-Tian Lin From the Department of Surgery, Shanghai Sixth People’s Hospital, Shanghai, 200233, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2002年第1期150-154,共5页
Objective: To evaluate the effect of early intrajejunalnutrition in attenuating bacterial and/or endotoxintranslocation and improving gut barrier function ofsevere acute pancreatitis (SAP) in dogs.Methods: 15 dogs wer... Objective: To evaluate the effect of early intrajejunalnutrition in attenuating bacterial and/or endotoxintranslocation and improving gut barrier function ofsevere acute pancreatitis (SAP) in dogs.Methods: 15 dogs were divided into parenteral nutrition(PN) group(7 dogs)and early intrajejunal nutrition(EIN) group(8). EIN was delivered nutrients via a nee-dle jejunostomy catheter feeding at 48h after operation.SAP model was induced by injecting 1 ml/kg of com-bined solution of 5% sodium taurocholate and 8000-10000 BAEE units trypsin/ml into the pancreas via thepancreatic duct. Systemic blood samples were ob-tained before and 1, 3, 5, 7 d following SAP, and culturedby aerobic as well as anaerobic bacterial growth. Systemicplasma and portal vein endotoxin levels were quantifiedby the chromogenic limulus amebocyte lysate (LAL)technique. Portal vein blood and specimens of tissuefrom the mesenteriolum and mesocolon lymph nodes,lung, pulmonary portal lymph nodes, pancreatitis tissueand periopancreas tissue were adopted before the experi-ment was finished. Aliquots of the homogenata were cul-tured as blood mentioned above to determine the magnitudeof the bacteria DNA, protein and the villi, the thickness ofmucosa, and the whole bowel wall of the ileum and trans-verse colon were measured.Results: The study showed that the levels of systemicplasma endotoxin and the magnitude of bacterialtranslocation to the portal and systemic blood and dis-tant organ were reduced significantly in the EINgroup as compared with the TPN group. The contentsof protein and DNA, the height of villi, the thicknessof mucosa and whole bowel wall of the ileum andtransverse colon in the EIN group were higher thanthose in the PN group.Conclusion: Our results suggested that EIN is safe andeffective to be adopted by intrajejunal delivery of nu-trients in SAP, decreases the occurrence of gut bacterialtranslocation, and improves the gut barrier function. 展开更多
关键词 early intrajejunal nutrition parenteral nutrition severe acute pancreatitis bacterial translocation barrier function
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In situ forming hydrogels based on chitosan for drug delivery and tissue regeneration 被引量:10
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作者 Li Liu qi gao +1 位作者 Xuemin Lu Huifang Zhou 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2016年第6期673-683,共11页
In situ forming hydrogels with simple sol–gel transition are more practicable as injectable hydrogels for drug delivery and tissue regeneration. State-of-the-art in situ gelling systems can easily and efficiently be ... In situ forming hydrogels with simple sol–gel transition are more practicable as injectable hydrogels for drug delivery and tissue regeneration. State-of-the-art in situ gelling systems can easily and efficiently be formed by different mechanisms in situ. Chitosan is a kind of natural polysaccharide that is widely exploited for biomedical applications due to its good biocompatibility, low immunogenicity and specific biological activities. Chitosan-based in situ gelling systems have already gained much attention as smart biomaterials in the development of several biomedical applications, such as for drug delivery systems and regeneration medicine. Herein, we review the typical in situ gelling systems based on chitosan and mechanisms involved in hydrogel forming, and report advances of chitosan-based in situ gels for the applications in drug delivery and tissue regeneration. Finally, development prospects of in situ forming hydrogels based on chitosan are also discussed in brief. 展开更多
关键词 In SITU GEL Sol–gel transition CHITOSAN DRUG delivery Tissue REGENERATION
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Long-term anodal block stimulation at sacral anterior roots promoted recovery of neurogenic bladder function in a rabbit model of complete spinal cord injury 被引量:6
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作者 Xiaoran Wang qi gao +11 位作者 Xiaoyu Yang Weihua Wang Xinquan Gu Guifeng Liu Peng Yan Ge gao Xin Yu Yongjie Wang Jihu Lian Chaoling Shi Yao Wang Li Fan 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第5期352-358,共7页
A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The... A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The rabbits were treated with anodal block stimulation at sacral anterior roots for 4 weeks. Electrical stimulation of sacral anterior roots improved urodynamic parameters of neurogenic bladder in rabbit models of complete spinal cord injury, effectively promoted urinary function, and relieved urinary retention. Immunohistochemistry results showed that a balance was achieved among expression of muscarinic receptor subunits M2, M3, ATP-gated ion channel P2X3 receptors, and 132-adrenergic receptor, and nerve growth factor expression decreased. These results suggested that long-term sacral anterior root stimulation of anodal block could'be used to treat neurogenic bladder in a rabbit model of complete spinal cord injury. 展开更多
关键词 anode block electrical stimulation immunohistochemistry neurogenic bladder URODYNAMICS spinal cord injury
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Characteristics of the Outer Rainband Stratiform Sector in Numerically Simulated Tropical Cyclones:Lower-Layer Shear versus Upper-Layer Shear 被引量:5
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作者 qi gao qingqing LI Yufan DAI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第4期399-419,共21页
Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical w... Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical wind shear(VWS)with moderate magnitude.Consistent with the results in previous studies,the outer rainband stratiform sector of the TCs simulated in both experiments is generally located downshear left.Upper-layer VWS tends to produce stronger asymmetric outflow at upper levels in the downshear-left quadrant than lower-layer shear.This stronger asymmetric outflow transports more water vapor radially outward from the inner core to the outer core at upper levels in the downshear-left quadrant in the upper-layer shear experiment.More depositional growth of both graupel and cloud ice thus occurs downshear left in upper layers in the outer core,yielding more diabatic heating and stronger upward motions,particularly in the stratiformdominated part of the stratiform sector in the upper-layer shear experiment.Resultingly,a better-organized stratiform sector in the outer rainbands is found in the upper-layer VWS experiment than in the lower-layer VWS experiment.The diabatic heating associated with the stratiform sector produces strong midlevel outflow on the radially inward side of,and weak midlevel inflow on the radially outward side of,the heating core,with lower-level inflow beneath the midlevel outflow and upper-level inflow above.The upper-layer VWS tends to produce a deeper asymmetric inflow layer in the outer rainband stratiform sector,with more significant lower-level inflow and tangential jets in the upper-layer VWS experiment. 展开更多
关键词 STRATIFORM outer rainband TROPICAL CYCLONE vertical wind shear
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Down-Regulation of Neurocan Expression in Reactive Astrocytes Promotes Axonal Regeneration and Facilitates the Neurorestorative Effects of Bone Marrow Stromal Cells in the Ischemic Rat Brain 被引量:51
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作者 LI HONG SHEN YI LI +2 位作者 qi gao SMITA SAVANT-BHONSALE AND MICHAEL CHOPP 《神经损伤与功能重建》 2008年第6期404-410,共7页
脑卒中后缺血组织边界形成胶质疤痕,抑制轴突再生。神经蛋白聚糖是一种轴突延长抑制分子,在卒中后胶质疤痕中表达上调。骨髓基质干细胞(BMSCs)可降低胶质疤痕壁的厚度,加速缺血周边区的轴突重塑。为了进一步明确BMSCs在轴突再生中的作... 脑卒中后缺血组织边界形成胶质疤痕,抑制轴突再生。神经蛋白聚糖是一种轴突延长抑制分子,在卒中后胶质疤痕中表达上调。骨髓基质干细胞(BMSCs)可降低胶质疤痕壁的厚度,加速缺血周边区的轴突重塑。为了进一步明确BMSCs在轴突再生中的作用及机制,本文重点研究脑缺血组织中BMSCs对神经蛋白聚糖表达的作用。31只成年雄性Wistar大鼠大脑中动脉阻塞(MCAo)2 h,24 h后从中选择16只给予尾静脉注射3×106鼠BMSCs(BMSCs组),15只注射磷酸盐缓冲生理盐水(对照组)。缺血后8 d处死实验大鼠,免疫染色表明反应性星形胶质细胞是神经蛋白聚糖的原始来源,且BMSCs组缺血半暗带脑组织的神经聚糖表达明显低于对照组,生长相关蛋白43表达高于对照组,这在蛋白印迹分析中得到确认。为了进一步检测BMSCs在星形胶质细胞神经蛋白聚糖表达中的作用,用激光捕获显微切割法从缺血周边区收集单纯的反应性星形胶质细胞。BMSCs组的神经蛋白聚糖基因表达明显下调(n=4/组)。原代培养的星形胶质细胞也表现出相同改变,糖氧剥离的星形胶质细胞再给氧时与BMSCs共培养会抑制神经蛋白聚糖基因的表达上调(n=3/组)。本研究表明BMSCs通过下调梗死周边星形胶质细胞中神经蛋白聚糖的表达来促进轴突再生。 展开更多
关键词 骨髓基质干细胞 卒中 轴突再生 神经蛋白聚糖 反应性星形胶质细胞
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Nrf2 epigenetic derepression induced by running exercise protects against osteoporosis 被引量:9
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作者 Xingren Chen Xiaobo Zhu +5 位作者 Ai Wei Fang Chen qi gao Ke Lu qing Jiang Wangsen Cao 《Bone Research》 SCIE CAS CSCD 2021年第2期178-187,共10页
Osteoporosis(OP)is a common skeletal disease involving low bone mineral density(BMD)that often leads to fragility fracture,and its development is affected by multiple cellular pathologies and associated with marked ep... Osteoporosis(OP)is a common skeletal disease involving low bone mineral density(BMD)that often leads to fragility fracture,and its development is affected by multiple cellular pathologies and associated with marked epigenetic alterations of osteogenic genes.Proper physical exercise is beneficial for bone health and OP and reportedly possesses epigenetic modulating capacities;however,whether the protective effects of exercise on OP involve epigenetic mechanisms is unclear.Here,we report that epigenetic derepression of nuclear factor erythroid derived 2-related factor-2(Nrf2),a master regulator of oxidative stress critically involved in the pathogenesis of OP,mediates the significant osteoprotective effects of running exercise(RE)in a mouse model of OP induced by ovariectomy.We showed that Nrf2 gene knockout(Nfe2l2^(−/−))ovariectomized mice displayed a worse BMD reduction than the controls,identifying Nrf2 as a critical antiosteoporotic factor.Further,femoral Nrf2 was markedly repressed with concomitant DNA methyltransferase(Dnmt)1/Dnmt3a/Dnmt3b elevations and Nrf2 promoter hypermethylation in both patients with OP and ovariectomized mice.However,daily 1-h treadmill RE significantly corrected epigenetic alterations,recovered Nrf2 loss and improved the femur bone mass and trabecular microstructure.Consistently,RE also normalized the adverse expression of major osteogenic factors,including osteoblast/osteoclast markers,Nrf2 downstream antioxidant enzymes and proinflammatory cytokines.More importantly,the RE-conferred osteoprotective effects observed in the wild-type control mice were largely abolished in the Nfe2l2^(−/−)mice.Thus,Nrf2 repression due to aberrant Dnmt elevation and subsequent Nrf2 promoter hypermethylation is likely an important epigenetic feature of the pathogenesis of OP,and Nrf2 derepression is essential for the antiosteoporotic effects of RE. 展开更多
关键词 EPIGENETIC NRF2 protective
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Electrical stimulation of the sacral nerve anterior root following induced bladder detrusor contraction 被引量:6
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作者 Peng Yan Xiaoyu Yang +3 位作者 qi gao Xiaoran Wang Jian Liu Maoguang Yang 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第24期1900-1904,共5页
The sacral nerve anterior root consists of parasympathetic nerves(dominating urinary bladder detrusor)and somatic motor nerves(dominating urethral sphincter),and electrical stimulation to the sacral nerve anterior... The sacral nerve anterior root consists of parasympathetic nerves(dominating urinary bladder detrusor)and somatic motor nerves(dominating urethral sphincter),and electrical stimulation to the sacral nerve anterior root induces simultaneous contraction of the bladder detrusor and urethral sphincter.Accordingly,urethral pressure exceeds intravesical pressure,resulting in little or no urination,kidney damage,and trembling of lower limbs due to high intravesical pressure.In the present study,sacral nerve posterior roots were transected in a spastic bladder rabbit model,followed by three-pole electrode and long-pulse electrical stimulation to the sacral anterior root.Intravesical and urethral pressures were simultaneously measured to verify the feasibility of anode inhibition to the sacral anterior root following induced detrusor contraction.As stimulus intensity increased,somatic motor nerves were increasingly inhibited; with a stimulus pulse width of 300 μs and stimulus current of 1.05 mA,urethral pressure was zero and average intravesical pressure was 3.84 kPa.In addition,detrusor contraction was displayed,and lower extremity trembling was significantly reduced.Three-pole electrode and long-pulse electrical stimulation to the sacral nerve anterior root induced detrusor contraction and inhibited low extremity trembling under electrical stimulation. 展开更多
关键词 anode block bladder detrusor electrical stimulation sacral anterior root
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