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A method to predict rockburst using temporal trend test and its application
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作者 Yarong Xue Zhenlei Li +5 位作者 Dazhao Song Xueqiu He Honglei Wang chao zhou Jianqiang Chen Aleksei Sobolev 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期909-923,共15页
Rockbursts have become a significant hazard in underground mining,underscoring the need for a robust early warning model to ensure safety management.This study presents a novel approach for rockburst prediction,integr... Rockbursts have become a significant hazard in underground mining,underscoring the need for a robust early warning model to ensure safety management.This study presents a novel approach for rockburst prediction,integrating the Mann-Kendall trend test(MKT)and multi-indices fusion to enable real-time and quantitative assessment of rockburst hazards.The methodology employed in this study involves the development of a comprehensive precursory index library for rockbursts.The MKT is then applied to analyze the real-time trend of each index,with adherence to rockburst characterization laws serving as the warning criterion.By employing a confusion matrix,the warning effectiveness of each index is assessed,enabling index preference determination.Ultimately,the integrated rockburst hazard index Q is derived through data fusion.The results demonstrate that the proposed model achieves a warning effectiveness of 0.563 for Q,surpassing the performance of any individual index.Moreover,the model’s adaptability and scalability are enhanced through periodic updates driven by actual field monitoring data,making it suitable for complex underground working environments.By providing an efficient and accurate basis for decision-making,the proposed model holds great potential for the prevention and control of rockbursts.It offers a valuable tool for enhancing safety measures in underground mining operations. 展开更多
关键词 ROCKBURST MICROSEISMICITY Early warning Mann-Kendall trend test Confusion matrix Multi-indices fusion
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Antibacterial and angiogenic dual-functional fibrous membrane dressing for infected wound healing
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作者 chao zhou Che Zhao +7 位作者 Hao-Yu Dai Tian-Jun Zhu Jia-Pei Yao Li Chen Jing-Jing Wen Jia Ling Celestine Loh Xin-Die zhou Yong Huang 《Biomedical Engineering Communications》 2024年第1期4-14,共11页
Background:Skin,being a vital organ that regulates physiological responses in the human body,is prone to injury from external environmental factors.Healing full-thickness skin defects becomes especially challenging wh... Background:Skin,being a vital organ that regulates physiological responses in the human body,is prone to injury from external environmental factors.Healing full-thickness skin defects becomes especially challenging when infections and vascular injuries are involved.Traditional wound dressings with single functions,such as antibacterial or angiogenic properties,fall short in achieving rapid wound healing.To address this,there is a need to develop wound dressing materials that possess both effective antibacterial and angiogenic properties.Methods:In this study,we utilized electrospinning technology to fabricate hyaluronic acid-cellulose acetate fibrous membrane dressings,incorporating poly(ionic liquid)as an antibacterial polymer and deferoxamine as an angiogenic agent.Results:The resulting fibrous membrane dressing contained poly(ionic liquid)and deferoxamin showcased a microporous structure,drug-releasing capabilities,and excellent air permeability.It not only demonstrated highly effective antibacterial properties but also exhibited remarkable angiogenesis,thereby promoting the healing of full-thickness skin defect wounds in both in vitro and in vivo assays.Conclusion:These findings highlight the immense potential of this wound dressing material for future clinical applications. 展开更多
关键词 electro spinning antibacterial polymer angiogenesis wound healing membrane dressing
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A two-step method to detect broadcast ephemeris unavailable periods caused by BeiDou satellite orbital maneuvers
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作者 Jingjing Wang chao zhou Zhixuan Sun 《Geodesy and Geodynamics》 EI CSCD 2023年第5期456-466,共11页
The space constellation of the BeiDou navigation satellite system(BDS) is a hybrid constellation containing medium earth orbit(MEO) satellites, geostationary earth orbit(GEO) satellites, and inclined geosynchronous or... The space constellation of the BeiDou navigation satellite system(BDS) is a hybrid constellation containing medium earth orbit(MEO) satellites, geostationary earth orbit(GEO) satellites, and inclined geosynchronous orbit(IGSO) satellites. Due to the geosynchronous characteristics of GEO and IGSO, GEO satellites and IGSO satellites often need to perform orbital maneuvers, which can affect the signal-inspace(SIS) availability performance of BeiDou satellites. A two-step detection method for BeiDou satellite orbital maneuvers has been proposed in this paper. The first step is to identify orbital maneuvers based on time series analysis of broadcast ephemeris, and the second step is to verify orbital maneuvers based on bidirectional orbit prediction. The two-step detection method was used to detect the orbital maneuvers of BeiDou satellites in 2019. Through the double guarantees of identification and verification,the detection accuracy of BeiDou satellite orbital maneuvers has been effectively improved. And the orbital maneuver detection results are continued to be used to assess the SIS availability of BeiDou satellites. The results show that the availability loss of GEO satellite orbital maneuvers is about 0.45%-1.07%, and the availability loss of IGSO satellite orbital maneuvers is about 0.12%-0.19%. 展开更多
关键词 BDS Orbital maneuver Signal-in-space AVAILABILITY Time series analysis
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Continuous positive airway pressure for treating hypoxemia due to pulmonary vein injury:A case report
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作者 chao zhou Shan Song +4 位作者 Jian-Feng Fu Xue-Lian Zhao Hua-Qin Liu Huan-Shuang Pei Hong-Bo Guo 《World Journal of Clinical Cases》 SCIE 2023年第8期1830-1836,共7页
BACKGROUND Vascular injury during thoracoscopic surgery for esophageal cancer is a rare but life-threatening complication that can lead to severe hypotension and hypoxemia.Anesthesiologists need to provide rapid and e... BACKGROUND Vascular injury during thoracoscopic surgery for esophageal cancer is a rare but life-threatening complication that can lead to severe hypotension and hypoxemia.Anesthesiologists need to provide rapid and effective treatment to save patients'lives.CASE SUMMARY A 54-year-old male patient was scheduled to undergo a thoracoscopic-assisted radical resection of esophageal cancer through the upper abdomen and right chest.While dissociating the esophagus from the carina through the right chest,unexpected profuse bleeding occurred from a suspected pulmonary vascular hemorrhage.While the surgeon attempted to achieve hemostasis,the patient developed severe hypoxemia.The anesthesiologist implemented continuous positive airway pressure(CPAP)using a bronchial blocker(BB),which effectively improved the patient’s oxygenation and the operation was completed success-fully.CONCLUSION CPAP using a BB can resolve severe hypoxemia caused by accidental injury of the left inferior pulmonary vein during surgery. 展开更多
关键词 Vascular injury Continuous positive airway pressure HYPOXEMIA Bronchial blocker Esophageal carcinoma resection Case report
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RASAL2 acts as a tumor suppressor in cervical cancer cells
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作者 LI CHEN FANGFANG LI +4 位作者 SHOUYAN CAO XIA LI chao zhou SAI HAN YOUZHONG ZHANG 《BIOCELL》 SCIE 2023年第7期1549-1560,共12页
This study was designed to investigate the roles of RASAL2 in cervical cancer(CC).Methods:Fifty-four CC tissues and 33 adjacent tissues were obtained from CC patients admitted to our hospital between March 2012 and Ju... This study was designed to investigate the roles of RASAL2 in cervical cancer(CC).Methods:Fifty-four CC tissues and 33 adjacent tissues were obtained from CC patients admitted to our hospital between March 2012 and June 2014.Real-time polymerase chain reaction and western blotting were performed to analyze the expression of RASAL2 mRNA and protein in these tissues,CC cell lines,and normal cervical cells.Over-expression and silencing of RASAL2 were induced after transfection,and the migration,invasion,and proliferation of the CC cell lines were examined.Results:RASAL2 mRNA and protein expressions were significantly down-regulated in CC tissues and cell lines than in adjacent tissues and normal cervical cells,respectively.While low RASAL2 expression correlated with advanced stage and metastasis of CC,its over-expression significantly inhibited proliferation and metastasis of CC cells and induced apoptosis.Under in vitro conditions,silencing of RASAL2 expression could significantly increase the proliferation,invasion,and migration of CC cells.Conclusion:RASAL2 functioned as a tumor suppressor in CC,and was down-regulated in CC tissue samples and cell lines. 展开更多
关键词 RASAL2 Cervical cancer KNOCKDOWN SILENCING Tumor suppressor
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Fish Feeding Behavior Recognition Using Adaptive DMCA-UMT Algorithm
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作者 Caiwei Yang Xinting Yang +1 位作者 Kaijie Zhu chao zhou 《Journal of Beijing Institute of Technology》 EI CAS 2023年第3期285-297,共13页
Realtime analyzing the feeding behavior of fish is the premise and key to accurate guidance on feeding.The identification of fish behavior using a single information is susceptible to various factors.To overcome the p... Realtime analyzing the feeding behavior of fish is the premise and key to accurate guidance on feeding.The identification of fish behavior using a single information is susceptible to various factors.To overcome the problems,this paper proposes an adaptive deep modular co-attention unified multi-modal transformers(DMCA-UMT).By fusing the video,audio and water quality parameters,the whole process of fish feeding behavior could be identified.Firstly,for the input video,audio and water quality parameter information,features are extracted to obtain feature vectors of different modalities.Secondly,deep modular co-attention(DMCA)is introduced on the basis of the original cross-modal encoder,and the adaptive learnable weights are added.The feature vector of video and audio joint representation is obtained by automatic learning based on fusion contribution.Finally,the information of visual-audio modality fusion and text features are used to generate clip-level moment queries.The query decoder decodes the input features and uses the prediction head to obtain the final joint moment retrieval,which is the start-end time of feeding the fish.The results show that the mAP Avg of the proposed algorithm reaches 75.3%,which is37.8%higher than that of unified multi-modal transformers(UMT)algorithm. 展开更多
关键词 AQUACULTURE multi-modal fusion deep modular co-attention(DMCA) unified multimodal transformers(UMT) video moment retrieval
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Construction of gene/protein interaction networks and enrichment pathway analysis for paroxysmal nocturnal hemoglobinuria and aplastic anemia
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作者 Gong-Xi Liu Zheng-Di Sun +2 位作者 chao zhou Jun-Yu Wei Jing Zhuang 《Medical Theory and Hypothesis》 2023年第2期19-26,共8页
Background:To develop a protein-protein interaction network of Paroxysmal nocturnal hemoglobinuria(PNH)and Aplastic anemia(AA)based on genetic genes and to predict pathways underlying the molecular complexes in the ne... Background:To develop a protein-protein interaction network of Paroxysmal nocturnal hemoglobinuria(PNH)and Aplastic anemia(AA)based on genetic genes and to predict pathways underlying the molecular complexes in the network.Methods:In this research,the PNH and AA-related genes were screened through Online Mendelian Inheritance in Man(OMIM).The plugins and Cytoscape were used to search literature and build a protein-protein interaction network.Results:The protein-protein interaction network contains two molecular complexes that are five higher than the correlation integral values.The target genes of this study were obtained:CD59,STAT3,TERC,TNF,AKT1,C5AR1,EPO,IL6,IL10 and so on.We also found that many factors regulate biological behaviors:neutrophils,macrophages,vascular endothelial growth factor,immunoglobulin,interleukin,cytokine receptor,interleukin-6 receptor,tumor necrosis factor,and so on.This research provides a bioinformatics foundation for further explaining the mechanism of common development of both.Conclusion:This indicates that the PNH and AA is a complex process regulated by many cellular pathways and multiple genes. 展开更多
关键词 protein interaction networks paroxysmal nocturnal hemoglobinuria Online Mendelian Inheritance in Man database aplastic anemia biological pathways
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某高校医学硕士研究生心理健康问题现状及对策研究 被引量:7
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作者 周超 张铮 +2 位作者 孙聪聪 崔明湖 张英姿 《中国高等医学教育》 2022年第2期132-134,共3页
目的:分析“医教协同”背景下医学硕士研究生心理健康问题现状,探讨开展医学生心理健康教育的对策。方法:选取某高校医学硕士研究生作为研究对象,进行问卷调查及统计分析,对影响因素进行调查分析,并制定相应的对策。结果:(1)医学硕士研... 目的:分析“医教协同”背景下医学硕士研究生心理健康问题现状,探讨开展医学生心理健康教育的对策。方法:选取某高校医学硕士研究生作为研究对象,进行问卷调查及统计分析,对影响因素进行调查分析,并制定相应的对策。结果:(1)医学硕士研究生存在心理健康问题最高和最低的因子分别是强迫症状和恐怖,检出率分别为9.06%、1.29%。(2)不同年级的医学硕士研究生均存在抑郁、焦虑等心理健康问题,其中2014级焦虑发生率最高(1.75%),2013级抑郁发生率最高(17.95%);心理健康问题最为严重的是2013级,检出率为10.20%。(3)医学硕士研究生SCL-90各个因子评分均低于常模组,差异具有统计学意义(P<0.001)。结论:医学硕士研究生面临着不同心理健康问题,只有社会、学校、导师等各方面给予支持和关爱,才能为其提供良好的成长环境。 展开更多
关键词 医教协同 医学院校 硕士 研究生 心理健康 医学教育
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大功率LED蒸发面三维强化沸腾结构优化(英文) 被引量:1
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作者 向建化 周超 +3 位作者 张春良 刘贵云 陈从桂 周伟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第7期1405-1413,共9页
利用热阻网络方法建立相变热沉理论模型,分析各参数对相变热沉热阻的影响,并确定影响热阻的主要因素。利用冲压挤压法在相变热沉蒸发面成形三维微沟槽强化沸腾结构以提高蒸发效率,并优化小型相变热沉制造的关键参数。另外,基于开发的测... 利用热阻网络方法建立相变热沉理论模型,分析各参数对相变热沉热阻的影响,并确定影响热阻的主要因素。利用冲压挤压法在相变热沉蒸发面成形三维微沟槽强化沸腾结构以提高蒸发效率,并优化小型相变热沉制造的关键参数。另外,基于开发的测试平台对相变热沉的传热性能进行测试。测试结果表明,该相变热沉具有良好的传热性能,适用于大功率LED的散热。 展开更多
关键词 大功率LED 相变热沉 冲压挤压法 强化沸腾 三维微沟槽
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基于近红外机器视觉的鱼类摄食强度评估方法研究 被引量:7
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作者 周超 徐大明 +4 位作者 吝凯 陈澜 张松 孙传恒 杨信廷 《智慧农业》 2019年第1期76-84,共9页
在水产养殖中,鱼类的摄食强度可以反映其食欲,准确客观地评估鱼类的摄食强度对指导投喂和生产实践具有重要意义。针对当前鱼类摄食强度评估过程中存在的人工观测效率低、客观性不强的问题,本研究以实现鱼类食欲的自动客观分析为目的,提... 在水产养殖中,鱼类的摄食强度可以反映其食欲,准确客观地评估鱼类的摄食强度对指导投喂和生产实践具有重要意义。针对当前鱼类摄食强度评估过程中存在的人工观测效率低、客观性不强的问题,本研究以实现鱼类食欲的自动客观分析为目的,提出了一种基于近红外机器视觉的游泳型鱼类摄食强度的评估方法。首先,利用近红外工业相机搭建了近红外图像采集系统,采集了鱼类摄食过程中的图像。经过一系列图像处理步骤后,利用灰度共生矩阵提取摄食图像的纹理特征变量信息,包括对比度、能量、相关性、逆差距和熵等。之后,将这5个特征变量作为输入向量构建了模型的数据集,并训练了支持向量机分类器。为了提高模型分类的准确率,利用网格搜索法选取支持向量机分类器的最优惩罚系数c和核函数参数g。最后利用训练好的模型将鱼类的摄食强度分为弱、一般、中和强4类,最终实现了鱼类摄食强度的评估。试验结果表明,图像纹理可以较好地描述鱼类摄食过程中的行为变化,正确识别4类摄食强度的准确率达到87.78%,且不需要考虑水花等对成像质量的影响,具有较强的适应性。本方法可用于鱼类食欲的自动客观评估,为后续投喂决策提供理论依据和方法支持。 展开更多
关键词 水产养殖 近红外机器视觉 鱼类摄食强度评估 支持向量机 投喂决策
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VR技术在医学计量与质量控制教育培训中的研究
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作者 周超 谭钦文 吴斌 《西藏医药》 2018年第4期4-6,共3页
目的通过对VR(虚拟现实)技术的研究,探讨了将VR技术运用于"VR/AR+培训"模式的重要意义。方法通过总结工作实践经验,针对医疗设备质量控制管理及其培训教学运用情况特点进行分类,分析存在的问题并给出建议。结果医院医疗设备... 目的通过对VR(虚拟现实)技术的研究,探讨了将VR技术运用于"VR/AR+培训"模式的重要意义。方法通过总结工作实践经验,针对医疗设备质量控制管理及其培训教学运用情况特点进行分类,分析存在的问题并给出建议。结果医院医疗设备质量管理的发展必须顺应时代发展的大环境,打破传统设备管理的工作模式,实现了先进的虚实结合,促进了教育培训多样化形式的发展;增加操作者身临其境的感觉,帮助他们快速掌握要领,提高了获得感和教学效果。结论 AR与VR技术在医学计量和质量检测培训中必将引领时代潮流。 展开更多
关键词 VR技术 医疗设备 计量质控 教育培训
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两步水热法合成Sn_2Nb_2O_7纳米晶及其高效可见光分解水制氢性能(英文) 被引量:2
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作者 周超 施润 +3 位作者 尚露 吴骊珠 佟振合 张铁锐 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第3期395-400,共6页
铌基半导体光催化材料因其具有独特的晶体结构和能带结构在光催化分解水制氢领域受到科研工作者的高度关注.然而,大多数铌基半导体光催化剂仅能够在紫外光驱动下实现光催化分解水制氢,具有可见光响应的铌基半导体光催化剂不仅数量少而... 铌基半导体光催化材料因其具有独特的晶体结构和能带结构在光催化分解水制氢领域受到科研工作者的高度关注.然而,大多数铌基半导体光催化剂仅能够在紫外光驱动下实现光催化分解水制氢,具有可见光响应的铌基半导体光催化剂不仅数量少而且活性较低,因此发展新型纳米铌基半导体光催化剂并实现其高效可见光催化分解水产氢具有重要的学术和实用意义.具有烧绿石构型的Sn_2Nb_2O_7材料由于具有较窄的禁带宽度(2.4 e V)和合适的导带和价带电势在可见光催化分解水制氢方面引起了科研人员广泛的兴趣.然而,目前报道的利用高温固相法制备的块体Sn_2Nb_2O_7材料由于颗粒尺寸较大和比表面积较小而导致光催化活性较差.因此,发展一种简便高效的制备方法实现纳米Sn_2Nb_2O_7材料的可控制备进而提高其可见光催化活性仍具有一定的挑战性.我们发展了一种简便的两步水热合成方法实现了Sn_2Nb_2O_7纳米晶的可控制备.扫描电镜和透射电镜测试结果表明,通过两步水热法得到的Sn_2Nb_2O_7纳米颗粒具有较好分散度,其平均颗粒尺寸为20 nm.X射线衍射测试结果也进一步证明,通过两步水热法可以实现Sn_2Nb_2O_7纳米晶的可控制备.比表面积测试结果表明,Sn_2Nb_2O_7纳米晶的比表面积约为52.2 m^2/g,远远大于固相法制备的块体Sn_2Nb_2O_7材料(2.3 m^2/g).大量研究表明,大的比表面积有利于半导体催化材料催化活性的提升.通过考查所制备的Sn_2Nb_2O_7纳米晶的可见光分解水制氢能力,对其催化性能进行了评价.研究结果表明,以乳酸为空穴消耗剂,负载0.3wt.%Pt纳米颗粒作为助催化剂的Sn_2Nb_2O_7纳米晶表现出优异的可见光催化分解水产氢性能,其产氢速率是块体Sn_2Nb_2O_7材料的5.5倍.Sn_2Nb_2O_7纳米晶可见光催化分解水产氢性能提高的主要原因是其具有高分散度的纳米颗粒、较大的比表面积和更正的价带电势.首先,颗粒尺寸的纳米化能够显著减小光生电子和空穴的迁移距离,实现光生载流子快速迁移到催化剂表面进而参与催化反应;其次,大的比表面积能够提供更多的催化活性位点,进而有利于催化活性的提高;最后,X射线光电子能谱测试表明,Sn_2Nb_2O_7纳米晶具有更正的价带电势,研究表明,价带电势越正,其光生空穴氧化能力越强.在光催化分解水制氢过程中,具有较强氧化能力的光生空穴通过与空穴牺牲剂乳酸快速反应而被消耗掉,抑制了光生电子与空穴的复合,进而导致其具有较高的光催化产氢活性. 展开更多
关键词 水热合成 Sn2Nb2O7 光催化 分解水 可见光驱动
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高效液相色谱法检测发酵液中四氢嘧啶及羟基四氢嘧啶 被引量:1
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作者 刘紫寒 郭秋爽 +3 位作者 周超 孙杨 李华 刘宇鹏 《日用化学工业(中英文)》 CAS 北大核心 2022年第11期1236-1240,共5页
为实现发酵液样品中四氢嘧啶和羟基四氢嘧啶的分离检测,使用高效液相色谱(HPLC)技术建立一种测定中度嗜盐菌发酵液中四氢嘧啶及羟基四氢嘧啶含量的方法。使用乙醇抽提法提取样品,采用Vertex^(TM) NH_(2)(4.6×250 mm,5μm)液相色谱... 为实现发酵液样品中四氢嘧啶和羟基四氢嘧啶的分离检测,使用高效液相色谱(HPLC)技术建立一种测定中度嗜盐菌发酵液中四氢嘧啶及羟基四氢嘧啶含量的方法。使用乙醇抽提法提取样品,采用Vertex^(TM) NH_(2)(4.6×250 mm,5μm)液相色谱柱对中度嗜盐菌发酵液中四氢嘧啶及四氢嘧啶进行了分析,选用紫外(UV)检测器,对比不同检测条件。通过色谱条件优化,选定了70%乙腈作为流动相,柱温30℃,检测波长210 nm,流速0.8 mL/min。发酵液样品中四氢嘧啶和羟基四氢嘧啶在各自范围内线性关系良好,两种样品的平均回收率在99.2%~102%,精密度偏差在1%~2%范围内,检出限为1.5μg/mL,定量限为5μg/mL,分离度为1.70。该方法检测范围大,具有较好的重复性、分离度及稳定性,适用于发酵液中四氢嘧啶及羟基四氢嘧啶的分离检测。 展开更多
关键词 中度嗜盐菌 高效液相色谱 四氢嘧啶 羟基四氢嘧啶
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可见光催化醛、酮或亚胺与缺电子芳烃还原偶联构筑芳基取代醇和胺(英文)
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作者 刘赞 南小磊 +6 位作者 雷涛 周超 王阳 刘文强 陈彬 佟振合 吴骊珠 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第3期487-494,共8页
通过C=X(X=O,N)双键极性翻转构筑碳-碳键是有机化学反应的重要合成策略.传统C=X(X=O,N)双键的极性翻转往往需要苛刻的反应条件和对水或空气敏感的强还原剂辅助,导致其适用范围受限.近年来,可见光催化反应以其独特高效的单电子转移特性,... 通过C=X(X=O,N)双键极性翻转构筑碳-碳键是有机化学反应的重要合成策略.传统C=X(X=O,N)双键的极性翻转往往需要苛刻的反应条件和对水或空气敏感的强还原剂辅助,导致其适用范围受限.近年来,可见光催化反应以其独特高效的单电子转移特性,在室温条件下实现了这一类贫电子官能团向亲核性中间体的高效转化.该策略已经拓展C=X(X=O,N)双键自身或与烷基链的偶联,从而得到烷基取代的醇和胺类化合物.本文利用可见光催化反应使C=X(X=O,N)双键极性翻转与芳香化合物的直接偶联,高效温和地合成芳基取代的醇和胺.反应无需强还原剂,底物适用范围广.该方法是对可见光催化C=X(X=O,N)双键极性翻转的重要补充,具有潜在的应用价值.本文以苯甲醛和1,4-二氰基苯为底物,fac-Ir(ppy)_3为光敏剂,二异丙基乙胺为终端还原剂,DMSO为溶剂,蓝光照射12 h能够以82%的收率实现模板反应.其它光敏剂如[Ru(bpy)3]Cl_2则不能催化该反应.溶剂效应指出,丙酮、乙腈可以得到低于40%的收率,甲醇、二氯甲烷、DMF等溶剂不适用该反应体系.控制实验证实,光敏剂、二异丙基乙胺和光照三个反应组分缺一不可.底物拓展发现,不同取代基的芳基腈类化合物包括烷基取代、砜基和酯基取代甚至杂芳环取代都能很好地适用于该体系,芳基醛、酮以及亚胺作为反应的另一组分亦能高效参与该还原偶联反应.自由基捕获实验证实反应过程中涉及自由基历程.光谱淬灭实验表明,芳香腈是唯一有效淬灭激发态fac-Ir(ppy)_3发光的物种.进一步结合底物的氧化还原电位,证实芳香腈能被激发态的光敏剂fac-Ir(ppy)_3还原,但二异丙基乙胺和芳香醛、酮不能与激发态光敏剂发生作用,催化反应经历光敏剂的氧化淬灭路径.首先,光敏剂受光激发到达激发态,与芳基腈发生单电子转移.随后,二异丙基乙胺促使失去电子的铱配合物还原再生,得到相应氮自由基阳离子.该氮自由基阳离子活化反应体系中的C=X(X=O,N)双键,使其从激发态铱物种得到电子形成苄位自由基,进而与得到电子的芳基氰偶联得到最终产物. 展开更多
关键词 芳基取代的醇和胺 还原偶联 极性翻转 光催化 芳基化
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High levels of serum interleukin-6 increase mortality of hepatitis B virus-associated acute-on-chronic liver failure 被引量:15
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作者 chao zhou Ning Zhang +11 位作者 Ting-Ting He Yao Wang Li-Fu Wang Yong-Qiang Sun Jing Jing Jing-Jing Zhang Shuang-Nan Fu Xuan Wang Xiao-Xiao Liang Xin Li Man Gong Jun Li 《World Journal of Gastroenterology》 SCIE CAS 2020年第30期4479-4488,共10页
BACKGROUND Patients with hepatitis B virus-associated acute-on-chronic liver failure(HBVACLF)present a complex and poor prognosis.Systemic inflammation plays an important role in its pathogenesis,and interleukin-6(IL-... BACKGROUND Patients with hepatitis B virus-associated acute-on-chronic liver failure(HBVACLF)present a complex and poor prognosis.Systemic inflammation plays an important role in its pathogenesis,and interleukin-6(IL-6)as a pro-inflammatory cytokine is related with severe liver impairment and also plays a role in promoting liver regeneration.Whether serum IL-6 influences HBV-ACLF prognosis has not been studied.AIM To determine the impact of serum IL-6 on outcome of patients with HBV-ACLF.METHODS We performed a retrospective study of 412 HBV-ACLF patients.The findings were analyzed with regard to mortality and the serum IL-6 level at baseline,as well as dynamic changes of serum IL-6 within 4 wk.RESULTS The serum IL-6 level was associated with mortality.Within 4 wk,deceased patients had significantly higher levels of IL-6 at baseline than surviving patients[17.9(7.3-57.6)vs 10.4(4.7-22.3),P=0.011].Patients with high IL-6 levels(>11.8 pg/mL)had a higher mortality within 4 wk than those with low IL-6 levels(≤11.8 pg/mL)(24.2%vs 13.2%,P=0.004).The odds ratios calculated using univariate and multivariate logistic regression were 2.10(95%confidence interval[CI]:1.26-3.51,P=0.005)and 2.11(95%CI:1.15-3.90,P=0.017),respectively.The mortality between weeks 5 and 8 in patients with high IL-6 levels at 4 wk was 15.0%,which was significantly higher than the 6.6%mortality rate in patients with low IL-6 levels at 4 wk(hazard ratio=2.39,95%CI:1.05-5.41,P=0.037).The mortality was 5.0%in patients with high IL-6 levels at baseline and low IL-6 levels at 4 wk,7.5%in patients with low IL-6 levels both at baseline and at 4 wk,11.5%in patients with low IL-6 levels at baseline and high IL-6 levels at 4 wk,and 16.7%in patients with high IL-6 levels both at baseline and at 4 wk.The increasing trend of the mortality rate with the dynamic changes of IL-6 was significant(P for trend=0.023).CONCLUSION A high level of serum IL-6 is an independent risk factor for mortality in patients with HBV-ACLF.Furthermore,a sustained high level or dynamic elevated level of serum IL-6 indicates a higher mortality. 展开更多
关键词 Hepatitis B virus Liver failure PROGNOSIS INTERLEUKIN-6
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Cervical inlet patch-optical coherence tomography imaging and clinical significance 被引量:3
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作者 chao zhou Tejas Kirtane +6 位作者 Tsung-Han Tsai Hsiang-Chieh Lee Desmond C Adler Joseph M Schmitt Qin Huang James G Fujimoto Hiroshi Mashimo 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第20期2502-2510,共9页
AIM:To demonstrate the feasibility of optical coherence tomography(OCT)imaging in differentiating cervical inlet patch(CIP)from normal esophagus,Barrett'sesophagus(BE),normal stomach and duodenum. METHODS:This stu... AIM:To demonstrate the feasibility of optical coherence tomography(OCT)imaging in differentiating cervical inlet patch(CIP)from normal esophagus,Barrett'sesophagus(BE),normal stomach and duodenum. METHODS:This study was conducted at the Veterans Affairs Boston Healthcare System(VABHS).Patients undergoing standard esophagogastroduodenoscopy at VABHS,including one patient with CIP,one representative patient with BE and three representative normal subjects were included.White light video endoscopy was performed and endoscopic 3D-OCT images were obtained in each patient using a prototype OCT system.The OCT imaging probe passes through the working channel of the endoscope to enable simultaneous video endoscopy and 3D-OCT examination of the human gastrointestinal(GI)tract.Standard hematoxylin and eosin(H and E)histology was performed on biopsy or endoscopic mucosal resection specimens in order to compare and validate the 3D-OCT data. RESULTS:CIP was observed from a 68-year old male with gastroesophageal reflux disease.The CIP region appeared as a pink circular lesion in the upper esophagus under white light endoscopy.OCT imaging over the CIP region showed columnar epithelium structure,which clearly contrasted the squamous epithelium structure from adjacent normal esophagus.3D-OCT images obtained from other representative patients demonstrated distinctive patterns of the normal esophagus,BE,normal stomach,and normal duodenum bulb.Microstructures,such as squamous epithelium,lamina propria, muscularis mucosa,muscularis propria,esophageal glands,Barrett's glands,gastric mucosa,gastric glands, and intestinal mucosal villi were clearly observed with OCT and matched with H and E histology.These results demonstrated the feasibility of using OCT to evaluate GI tissue morphology in situ and in real-time. CONCLUSION:We demonstrate in situ evaluation of CIP microstructures using 3D-OCT,which may be a useful tool for future diagnosis and follow-up of patients with CIP. 展开更多
关键词 扫描成像 光学相干 断层扫描 临床意义 视频内窥镜 微观结构 进口 颈椎
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Mechanism and monitoring and early warning technology for rockburst in coal mines 被引量:3
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作者 Xue-qiu He chao zhou +4 位作者 Da-zhao Song Zhen-lei Li An-ye Cao Shen-quan He Majid Khan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第7期1097-1111,共15页
On the basis of the massive amount of published literature and the long-term practice of our research group in the field of prevention and control of rockburst,the research progress and shortcomings in understanding t... On the basis of the massive amount of published literature and the long-term practice of our research group in the field of prevention and control of rockburst,the research progress and shortcomings in understanding the rockburst phenomenon have been comprehensively in-vestigated.This study focuses on the occurrence mechanism and monitoring and early warning technology for rockburst in coal mines.Results showed that the prevention and control of rockburst had made significant progress.However,with the increasing mining depth,several unre-solved concerns remain challenging.From the in-depth research and analysis,it can be inferred that rockburst disasters involve three main problems,i.e.,the induction factors are complicated,the mechanism is still unclear,and the accuracy of the monitoring equipment and multi-source stereo monitoring technology is insufficient.The monitoring and warning standards of rockburst need to be further clarified and im-proved.Combined with the Internet of Things,cloud computing,and big data,a study of the trend of rockburst needs to be conducted.Further-more,the mechanism of multiphase and multi-field coupling induced by rockburst on a large scale needs to be explored.A multisystem and multiparameter integrated monitoring and early warning system and remote monitoring cloud platform for rockburst should be explored and developed.High-reliability sensing technology and equipment and perfect monitoring and early warning standards are considered to be the de-velopment direction of rockburst in the future.This research will help experts and technicians adopt effective measures for controlling rock-burst disasters. 展开更多
关键词 coal mine ROCKBURST MECHANISM monitoring and early warning technology MULTIPARAMETER
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Downregulation of miR-491-5p promotes neovascularization after traumatic brain injury 被引量:1
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作者 Wei Tang Zong-Duo Guo +9 位作者 Wei-Na Chai Dong-Lin Du Xiao-Min Yang Lang Cao Hong Chen chao zhou Chong-Jie Cheng Xiao-Chuan Sun Zhi-Jian Huang Jian-Jun Zhong 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第3期577-586,共10页
Micro RNA-491-5 p(miR-491-5 p) plays an important role in regulating cell proliferation and migration;however,the effect of miR-491-5 p on neovascularization after traumatic brain injury remains poorly understood.In t... Micro RNA-491-5 p(miR-491-5 p) plays an important role in regulating cell proliferation and migration;however,the effect of miR-491-5 p on neovascularization after traumatic brain injury remains poorly understood.In this study,a controlled cortical injury model in C57 BL/6 mice and an oxygen-glucose deprivation model in microvascular endothelial cells derived from mouse brain were established to simulate traumatic brain injury in vivo and in vitro,respectively.In the in vivo model,quantitative real-time-polymerase chain reaction results showed that the expression of miR-491-5 p increased or decreased following the intracerebroventricular injection of an miR-491-5 p agomir or antagomir,respectively,and the expression of miR-491-5 p decreased slightly after traumatic brain injury.To detect the neuroprotective effects of miR-491-p,neurological severity scores,Morris water maze test,laser speckle techniques,and immunofluorescence staining were assessed,and the results revealed that miR-491-5 p downregulation alleviated neurological dysfunction,promoted the recovery of regional cerebral blood flow,increased the number of lectin-stained microvessels,and increased the survival of neurons after traumatic brain injury.During the in vitro experiments,the potential mechanism of miR-491-5 p on neovascularization was explored through quantitative real-time-polymerase chain reaction,which showed that miR-491-5 p expression increased or decreased in brain microvascular endothelial cells after transfection with an miR-491-5 p mimic or inhibitor,respectively.Dual-luciferase reporter and western blot assays verified that metallothionein-2 was a target gene for miR-491-5 p.Cell counting kit 8(CCK-8) assay,flow cytometry,and 2′,7′-dichlorofluorescein diacetate(DCFH-DA) assay results confirmed that the downregulation of miR-491-5 p increased brain microvascular endothelial cell viability,reduced cell apoptosis,and alleviated oxidative stress under oxygen-glucose deprivation conditions.Cell scratch assay,Transwell assay,tube formation assay,and western blot assay results demonstrated that miR-491-5 p downregulation promoted the migration,proliferation,and tube formation of brain microvascular endothelial cells through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor pathway.These findings confirmed that miR-491-5 p downregulation promotes neovascularization,restores cerebral blood flow,and improves the recovery of neurological function after traumatic brain injury.The mechanism may be mediated through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway and the alleviation of oxidative stress.All procedures were approved by Ethics Committee of the First Affiliated Hospital of Chongqing Medical University,China(approval No.2020-304) on June 22,2020. 展开更多
关键词 brain injury cell migration cell proliferation endothelial cell hypoxia-inducible factor-1 alpha metallothionein 2 microRNA NEOVASCULARIZATION neurons vascular endothelial growth factor
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Pentraxin 3 contributes to neurogenesis after traumatic brain injury in mice 被引量:1
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作者 chao zhou Hong Chen +6 位作者 Jian-Feng Zheng Zong-Duo Guo Zhi-Jian Huang Yue Wu Jian-Jun Zhong Xiao-Chuan Sun Chong-Jie Cheng 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第12期2318-2326,共9页
Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation.It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes,and poten... Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation.It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes,and potentially has multiple protective effects in stroke;however,its role in the adult brain after traumatic brain injury is unknown.In the present study,a moderate model of traumatic brain injury in mice was established using controlled cortical impact.The models were intraventricularly injected with recombinant pentraxin 3(the recombinant pentraxin 3 group)or an equal volume of vehicle(the control group).The sham-operated mice underwent craniotomy,but did not undergo the controlled cortical impact.The potential neuroprotective and neuroregenerative roles of pentraxin 3 were investigated on days 14 and 21 after traumatic brain injury.Western blot assay showed that the expression of endogenous pentraxin 3 was increased after traumatic brain injury in mice.Furthermore,the neurological severity test and wire grip test revealed that recombinant pentraxin 3 treatment reduced the neurological severity score and increased the wire grip score,suggesting an improved recovery of sensory-motor functions.The Morris water maze results demonstrated that recombinant pentraxin 3 treatment reduced the latency to the platform,increased the time spent in the correct quadrant,and increased the number of times traveled across the platform,thus suggesting an improved recovery of cognitive function.In addition,to investigate the effects of pentraxin 3 on astrocytes,specific markers of A2 astrocytes were detected in primary astrocyte cultures in vitro using western blot assay.The results demonstrated that pentraxin 3 administration activates A2 astrocytes.To explore the protective mechanisms of pentraxin 3,immunofluorescence staining was used.Intraventricular injection of recombinant pentraxin 3 increased neuronal maintenance in the peri-injured cortex and ipsilateral hippocampus,increased the number of doublecortin-positive neural progenitor cells in the subventricular and subgranular zones,and increased the number of bromodeoxyuridine(proliferation)and neuronal nuclear antigen(mature neuron)double-labeled cells in the hippocampus and peri-injured cortex.Pentraxin 3 administration also increased the number of neurospheres and the number of bromodeoxyuridine and doublecortin double-labeled cells in neurospheres,and enhanced the proliferation of neural progenitor cells in primary neural progenitor cell cultures in vitro.In conclusion,recombinant pentraxin 3 administration activated A2 astrocytes,and consequently improved the recovery of neural function by increasing neuronal survival and enhancing neurogenesis.All experiments were approved by the Animal Ethics Committee of the First Affiliated Hospital of Chongqing Medical University,China on March 1,2016. 展开更多
关键词 brain injury brain trauma cells NEUROGENESIS PLASTICITY protein recovery REGENERATION
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CD4^+肠上皮内淋巴细胞分化调节机制及在肠道稳态维持中的作用 被引量:2
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作者 周超 邱远 +1 位作者 杨桦 肖卫东 《世界华人消化杂志》 CAS 2018年第27期1598-1604,共7页
CD4^+上皮内淋巴细胞是位于肠道上皮基底层内的一类特殊的淋巴细胞.根据细胞表型和功能的不同,CD4^+上皮内淋巴细胞可以分为多个亚群,主要有Th1细胞、Th2细胞、Th17细胞.综合现有文献及本课题组的研究结果可以发现, CD4^+上皮内淋巴细... CD4^+上皮内淋巴细胞是位于肠道上皮基底层内的一类特殊的淋巴细胞.根据细胞表型和功能的不同,CD4^+上皮内淋巴细胞可以分为多个亚群,主要有Th1细胞、Th2细胞、Th17细胞.综合现有文献及本课题组的研究结果可以发现, CD4^+上皮内淋巴细胞在肠道稳态维持机制中发挥着重要作用.多种转录因子、肠道微生物、营养素能够调节CD4^+上皮内淋巴细胞在肠道中的增殖、分化与凋亡; CD4^+上皮内淋巴细胞在炎症性肠病的发病中也发挥重要作用.本文就CD4^+上皮内淋巴细胞的分化调节机制以及它在肠道稳态维持机制中的重要作用作一综述,为阐明肠道炎症性疾病发病机制提供一些新的思路. 展开更多
关键词 CD4^+肠上皮内淋巴细胞 炎症性肠病 肠道菌群 肠屏障
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