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Advanced strategies in the application of gelatin-based bioink for extrusion bioprinting 被引量:1
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作者 Jirong Yang Huimin He +3 位作者 duo li Qian Zhang lizhi Xu Changshun Ruan 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2023年第5期586-608,共23页
The significance of bioink suitability for the extrusion bioprinting of tissue-like constructs cannot be overemphasized.Gelatin,derived from the hydrolysis of collagen,not only can mimic the extracellular matrix to imm... The significance of bioink suitability for the extrusion bioprinting of tissue-like constructs cannot be overemphasized.Gelatin,derived from the hydrolysis of collagen,not only can mimic the extracellular matrix to immensely support cell function,but also is suitable for extrusion under certain conditions.Thus,gelatin has been recognized as a promising bioink for extrusion bioprinting.However,the development of a gelatin-based bioink with satisfactory printability and bioactivity to fabricate complex tissue-like constructs with the desired physicochemical properties and biofunctions for a specific biomedical application is still in its infancy.Therefore,in this review,we aim to comprehensively summarize the state-of-the-art methods of gelatin-based bioink application for extrusion bioprinting.Wefirstly outline the properties and requirements of gelatin-based bioinks for extrusion bioprinting,highlighting the strategies to overcome their main limitations in terms of printability,structural stability and cell viability.Then,the challenges and prospects are further discussed regarding the development of ideal gelatin-based bioinks for extrusion bioprinting to create complex tissue-like constructs with preferable physicochemical properties and biofunctions. 展开更多
关键词 Gelatin-based bioink Extrusion bioprinting Tissue-like construct
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Genetic mechanism of body size variation in groupers:Insights from phylotranscriptomics
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作者 Wei-Wei Zhang Zhuo-Ying Weng +5 位作者 Xi Wang Yang Yang duo li Le Wang Xiao-Chun liu Zi-Ning Meng 《Zoological Research》 SCIE CSCD 2024年第2期314-328,共15页
Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within ... Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size,providing an excellent opportunity to investigate the genetic basis of body size variation in vertebrates.Herein,we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China Sea.Two genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size,respectively.A total of 180 rapidly evolving genes and two positively selected genes were identified between the two groups.Functional enrichment analyses of these candidate genes revealed distinct enrichment categories between the two groups.These pathways and genes may play important roles in body size variation in groupers through complex regulatory networks.Based on our results,we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection,leading to genetic variations in metabolic patterns,organ development,and lifespan,resulting in body size divergence between the two locally adapted populations.These findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation. 展开更多
关键词 Phylotranscriptomics GROUPER Body size Rapidly evolving genes(REGs) Positively selected genes(PSGs)
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Punicalagin prevents obesity-related cardiac dysfunction through promoting DNA demethylation in mice
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作者 Shengjie Pei Run liu +10 位作者 Qingqing Ma Peng Jiang Xin He Zhongshi Qi Jiacheng Fang Xu Yang Zirui Yao Xiaoqian liu Xianfeng Jing Lei Chen duo li 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1465-1474,共10页
The aim of this study was to investigate whether punicalagin(PU)could prevent obesity-related cardiac dysfunction by promoting DNA demethy lation,and to explore its possible mechanism.C57BL/6J mice were fed with stand... The aim of this study was to investigate whether punicalagin(PU)could prevent obesity-related cardiac dysfunction by promoting DNA demethy lation,and to explore its possible mechanism.C57BL/6J mice were fed with standard diet,high-fat diet(HFD),HFD supplemented with resveratrol,low-dose PU(LPU)and high-dose PU(HPU)for 8 weeks.Compared with HFD group,body weight was significantly lower in PU treatment groups,number of cardionwocytes and the protein level of myosin heavy chain 7B were significantly higher in PU treatment groups.Levels of 5-hydroxymethylcytosine and 5-formylcytosine were significantly lower in HFD group than in other groups.Compared with the HFD group,the protein level of ten-eleven translocation enzyme(TET)2 was significantly higher in PU treatment groups,p-AMP-activated protein kinase(AMPK)was significantly higher in LPU group.Levels of total antioxidant capacity and the protein levels of complexesⅡ/Ⅲ/Ⅴ,oxoglutarate dehydrogenase,succinate dehydrogenase B and fumarate hdrolase were significantly lower in HFD group than PU treatment group.The ratio of(succinic acid+fumaric acid)/a-ketoglutarate was significantly higher in HFD group than other groups.In conclusion,PU up-regulated TETs enzyme activities and TET2 protein stability through alleviating mitochondrial dysfunction and activating AMPK,so as to promote DNA demethylation,thus preventing obesity-related cardiac dysfunction. 展开更多
关键词 DNA demethylation Mitochondrial function Obesity-related cardiac dysfunction PUNICALAGIN Ten-eleven translocation family enzymes
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Ammonia-treatment assisted fully encapsulation of Fe_2O_3 nanoparticles in mesoporous carbons as stable anodes for lithium ion batteries 被引量:4
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作者 Fei Han Wen-Cui li +1 位作者 duo li An-Hui Lu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第2期329-335,共7页
To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surf... To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area (〉1700 m2.g-1) and large pore volume (〉1.8 cm3-g-1). Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance (683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle) as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material. 展开更多
关键词 ordered mesoporous carbon Fe203 nanoparticle cycle stability lithium-ion anode
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Controllable synthesis of high loading LiFePO_4/C nanocomposites using bimodal mesoporous carbon as support for high power Li-ion battery cathodes 被引量:2
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作者 Fei Cheng duo li +1 位作者 Anhui Lu Wencui li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第6期907-913,共7页
Mesoporous LiFePO4/C composites containing 80 wt% of highly dispersed LiFePO4 nanoparticles(4-6 nm) were fabricated using bimodal mesoporous carbon(BMC) as continuous conductive networks. The unique pore structure of ... Mesoporous LiFePO4/C composites containing 80 wt% of highly dispersed LiFePO4 nanoparticles(4-6 nm) were fabricated using bimodal mesoporous carbon(BMC) as continuous conductive networks. The unique pore structure of BMC not only promises good particle connectivity for LiFePO4, but also acts as a rigid nano-confinement support that controls the particle size. Furthermore, the capacities were investigated respectively based on the weight of LiFePO4 and the whole composite. When calculated based on the weight of the whole composite, it is 120 mAh·g-1at 0.1 C of the high loading electrode and 42 mAh·g-1at 10 C of the low loading electrode. The electrochemical performance shows that high LiFePO4 loading benefits large tap density and contributes to the energy storage at low rates, while the electrode with low content of LiFePO4 displays superior high rate performance, which can mainly be due to the small particle size, good dispersion and high utilization of the active material, thus leading to a fast ion and electron diffusion. 展开更多
关键词 LIFEPO4 high loading fast ion diffusion high rate performance lithium-ion batteries
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A novel xeno-free culture system for human retinal pigment epithelium cells 被引量:1
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作者 Han Shen Min Wang +2 位作者 duo li Song-Tao Yuan Qing-Huai liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2019年第4期563-570,共8页
AIM: To find out an animal-free, xeno-free culture method for human fetal retinal pigment epithelium(fRPE) cells aiming for cell-replacement therapy. METHODS: Human AB serum, knock-out serum replacement(KSR) and B27 w... AIM: To find out an animal-free, xeno-free culture method for human fetal retinal pigment epithelium(fRPE) cells aiming for cell-replacement therapy. METHODS: Human AB serum, knock-out serum replacement(KSR) and B27 were supplemented as a substitute of fetal bovine serum(FBS) in culture medium of human fRPE cells. Cell morphology was examined by light microscope and transmission electron microscope. Proliferation ability was detected by cell cycle analysis and examination of KI67 expression. Apoptosis was analyzed using FACS. The expression ofRPE-specific markers was demonstrated by quantitative real-time polymerase chain reaction(qPCR), Western blot(WB) and immunocytochemistry. Paracrine function was determined using enzyme-linked immunosorbent assay method.RESULTS: Our results indicated that the optimum concentration of KSR was 15%, the optimum concentration of B27 was 2%, and the optimum concentration of human AB serum was 10%. fRPE cells cultured in 15% KSR and 2% B27 media showed repressed propagation and differentiation ability, and gradually lost epithelial morphology and RPE function. While fRPE cells cultured in 10% human AB serum media showed a typical cobblestone morphology with pigmentation, elevated proliferation ability, satisfying paracrine function and expressed RPE-specific markers. CONCLUSION: Our study indicates that culturing fRPE cells in 10% human AB serum-supplemented medium is more favorable compared with KSR, B27 and traditional FBS-supplemented mediums when fRPE cells are to be applied in cell-based therapy. 展开更多
关键词 RETINAL PIGMENT EPITHELIUM human AB SERUM cell-based THERAPY
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Chordin-like 2 influences the differentiation fate of retinal pigment epithelium cells by dynamically regulating BMP pathway 被引量:1
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作者 duo li Song-Tao Yuan +3 位作者 Xin-Yi Xie Han Shen Qing-Huai liu Yong Yao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第5期711-720,共10页
AIM:To explore the functions of Chordin-like 2,which is encoded by CHRDL2,in the process of retinal pigmented epithelium(RPE)differentiation and damage repair.METHODS:The fetal RPE cells(f RPE)was obtained from aborte... AIM:To explore the functions of Chordin-like 2,which is encoded by CHRDL2,in the process of retinal pigmented epithelium(RPE)differentiation and damage repair.METHODS:The fetal RPE cells(f RPE)was obtained from aborted fetus which obeyed medical ethics.Real-time quantitative polymerase chain reaction was used to measure expression quantity of CHRDL2 and other functional genes expression.Knocking down and overexpression was used to analyze the functions about Chordin-like 2.Enzyme-linked immunosorbent assay(ELISA)was used to detect the secretion of bone morphogenetic proteins 4(BMP4).Flow cytometry was used to analyze cell cycle.Cell morphology was observed by phase contrast microscope(PCM).RESULTS:In normal RPE cells,CHRDL2 was firstly upregulated and followed a downregulation but eventually,it was expressed higher than the cells which undergone epithelial-mesenchymal transition(EMT).After knocking down CHRDL2,the secretion of BMP4 was decreased,RPErelated genes(OTX2,MITF,RPE65)were downregulated while EMT-related genes(SNAI1,VIM)were upregulated.However,the expression of these related genes after overexpression of CHRDL2 had contrary results.Chordin-like 2 also regulated the cell cycle by regulating BMP pathway.When CHRDL2 was knocked down,more f RPE cells stayed in S phase of cell cycle,while adding BMP4 reduced the proportion of the cells in S phase.However,overexpression of CHRDL2 increased more BMP4 secretion,this effect decreased the number of cells in S phase,but exogenous BMP inhibitor also could change this effect.At last,in the process of RPE cells differentiation,adding BMP4 at early stage could intervene normal RPE differentiation.Compared with BMP4,inhibiting BMP pathway had no significant negative effect at early stage,but suppressed differentiation at late stage.CONCLUSION:BMP pathway can be activated in a correct temporal order,otherwise,the cells have incorrect differentiation orientation.And Chordin-like 2 plays a role in dynamic regulation of BMP pathway and it also regulates the differentiation of RPE cells.Therefore,this research enlightens a new direction to inhibit EMT and promote cell redifferentiation after injury. 展开更多
关键词 retinal pigmented epithelium differentiation epithelial-mesenchymal transition BMP pathway cell proliferation
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Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems: A Case Study in the Atlanta Region
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作者 Jean-Ann James Valerie M. Thomas +2 位作者 Arka Pandit duo li John C. Crittenden 《Engineering》 SCIE EI 2016年第4期470-480,共11页
The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the po... The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO2) and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling) demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamilv residential buildings. 展开更多
关键词 Combined cooling heating and power (CCHP) Air-cooled microturbines Distributed energy generation Water for energy production Net metering
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Review of Related Research on Urban Planning Discipline Based on Feminist Perspective
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作者 duo Ouyang Shaoyao He duo li 《International Journal of Technology Management》 2017年第3期44-46,共3页
This paper summarizes the research progress and the main problems in this field by combing the domestic and foreign urban planning disciplines and other related disciplines in the field of "feminism" , and explores ... This paper summarizes the research progress and the main problems in this field by combing the domestic and foreign urban planning disciplines and other related disciplines in the field of "feminism" , and explores the feminist research perspective into the planning The influence and significance of theory and practice, and finally put forward the research direction of domestic urban planning field combined with feminist perspective. 展开更多
关键词 Urban planning FEMINISM The research reviewed
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3D-bioprinted anisotropic bicellular living hydrogels boost osteochondral regeneration via reconstruction of cartilage–bone interface 被引量:2
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作者 Yijian Zhang duo li +7 位作者 Yang liu liuqi Peng Dongdong Lu Pinpin Wang Dongxu Ke Huilin Yang Xuesong Zhu Changshun Ruan 《The Innovation》 EI 2024年第1期88-97,共10页
Reconstruction of osteochondral(OC)defects represents an immense challenge due to the need for synchronous regeneration of special stratified tissues.The revolutionary innovation of bioprinting provides a robust metho... Reconstruction of osteochondral(OC)defects represents an immense challenge due to the need for synchronous regeneration of special stratified tissues.The revolutionary innovation of bioprinting provides a robust method for precise fabrication of tissue-engineered OCs with hierarchical structure;however,their spatial living cues for simultaneous fulfilment of osteogenesis and chondrogenesis to reconstruct the cartilage-bone interface of OC are underappreciated.Here,inspired by natural OC bilayer features,anisotropic bicellular living hydrogels(ABLHs)simultaneously embedding articular cartilage progenitor cells(ACPCs)and bone mesenchymal stem cells(BMSCs)in stratified layers were precisely fabricated via two-channel extrusion bioprinting.The optimum formulation of the 7%GelMA/3%AlgMA hydrogel bioink was demonstrated,with excellent printability at room temperature and maintained high cell viability.Moreover,the chondrogenic ability of ACPCs and the osteogenic ability of BMSCs were demonstrated in vitro,confirming the inherent differential spatial regulation of ABLHs. 展开更多
关键词 PRINTING STRATIFIED BOOST
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临床试验用药品管理问题以及改进措施分析
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作者 多丽 巴特 《中国卫生产业》 2023年第21期242-245,共4页
通过对临床试验用药品管理规范,可以实现临床合理用药,提高医疗服务质量,加强临床试验用药品管理对于改善医患关系,推进医药卫生体制的变革,都有着重要的意义。本研究基于药物临床试验的重要性,分析了我国临床试验用药品管理现状以及存... 通过对临床试验用药品管理规范,可以实现临床合理用药,提高医疗服务质量,加强临床试验用药品管理对于改善医患关系,推进医药卫生体制的变革,都有着重要的意义。本研究基于药物临床试验的重要性,分析了我国临床试验用药品管理现状以及存在的问题,并提出了相应的改进措施。 展开更多
关键词 临床试验 药品管理 问题 改进措施
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非结核分枝杆菌肺病的CT分型及其临床特征分析(附132例报告) 被引量:6
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作者 李多 房坤 +2 位作者 王珏 周震 吕平欣 《中国防痨杂志》 CAS CSCD 2019年第2期202-209,共8页
目的分析非结核分枝杆菌肺病的CT分型,以及不同型别患者的临床及CT表现特点。方法回顾性分析2011年11月至2018年1月首都医科大学附属北京胸科医院确诊的132例非结核分枝杆菌肺病患者的临床及CT资料,根据CT表现分为上叶空洞型、结节支气... 目的分析非结核分枝杆菌肺病的CT分型,以及不同型别患者的临床及CT表现特点。方法回顾性分析2011年11月至2018年1月首都医科大学附属北京胸科医院确诊的132例非结核分枝杆菌肺病患者的临床及CT资料,根据CT表现分为上叶空洞型、结节支气管扩张型、混合型和不易分类型4种类型,统计分析不同CT分型患者的临床及CT特征。采用SPSS17.0软件进行统计学分析,计数资料采用χ^2检验或连续校正χ^2检验,计量资料采用t检验或方差分析,均以P<0.05为差异有统计学意义;4组不同CT型别患者的临床统计数据进行两两比较时,以P<0.008为差异有统计学意义。结果132例非结核分枝杆菌肺病CT分型结果为:上叶空洞型36例(27.3%),结节支气管扩张型61例(46.2%),混合型15例(11.4%),不易分类型20例(15.2%)。非结核分枝杆菌肺病不同CT分型组中,男性构成比由高到低分别为上叶空洞型(86.1%,31/36)、不易分类型(70.0%,14/20),混合型(53.3%,8/15)和结节支气管扩张型(24.6%,15/61),差异有统计学意义(χ^2=37.712,P<0.001)。上叶空洞型、结节支气管扩张型、混合型和不易分类型患者平均年龄分别为(58.5±13.8)岁、(58.1±13.3)岁、(61.3±10.4)岁和(51.0±17.0)岁,差异无统计学意义(F=1.875,P=0.140)。上叶空洞型患者中吸烟者占64.7%(22/34),明显高于结节支气管扩张型患者(13.0%,7/54)(χ^2=25.258,P<0.001)。上叶空洞型患者发生肺气肿者占66.7%(24/36),发生间质纤维化改变者占33.3%(12/36),明显高于结节支气管扩张型[分别为13.1%(8/61)和0.0%(0/61)](χ^2=29.369、23.204,P值均<0.001)。上叶空洞型并发胸膜增厚者占61.1%(22/36),明显高于结节支气管扩张型(23.0%,14/61)(χ^2=14.125,P<0.001);混合型患者并发胸膜增厚者占66.7%(10/15),同样高于结节支气管扩张型(χ^2=10.649,P=0.001)。结论非结核分枝杆菌肺病中,结节支气管扩张型最常见;上叶空洞型好发于男性有肺气肿和(或)间质纤维化改变的患者,结节支气管扩张型好发于女性无肺部基础疾病(未并发肺部其他种类疾病,包括肺气肿、间质纤维化等)的患者。 展开更多
关键词 分枝杆菌感染 非典型性 肺疾病 体层摄影术 X线计算机 诊断显像
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耐多药肺结核并发糖尿病患者胸部CT扫描特征分析 被引量:6
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作者 李多 张福芝 +2 位作者 曹宝霞 侯代伦 吕平欣 《中国防痨杂志》 CAS CSCD 2019年第7期765-769,共5页
目的分析耐多药肺结核并发糖尿病患者与未并发糖尿病患者的胸部CT表现,以提高临床认识。方法通过《首都医科大学附属北京胸科医院病案电子化管理系统》,搜集2012—2017年经改良罗氏培养基痰培养及绝对浓度法药物敏感性试验(简称“药敏... 目的分析耐多药肺结核并发糖尿病患者与未并发糖尿病患者的胸部CT表现,以提高临床认识。方法通过《首都医科大学附属北京胸科医院病案电子化管理系统》,搜集2012—2017年经改良罗氏培养基痰培养及绝对浓度法药物敏感性试验(简称“药敏试验”)确诊的耐多药肺结核且符合排除标准的660例患者资料,按照是否并发糖尿病将患者分为并发糖尿病组(159例,并发组)、未并发糖尿病组(501例,未并发组)。采用数字表法从两组患者中分别随机抽取60例患者进行对照研究,由2名影像科经验丰富医师在不知患者是否并发糖尿病的情况下重新阅读CT片,以记录胸部CT表现及病变分布范围。采用SPSS 17.0软件进行统计学分析,计数资料采用卡方检验或Fisher精确概率检验,计量资料采用非参数检验方法中的曼-惠特妮U检验,以P<0.05为差异有统计学意义。结果并发组患者中的段或叶性实变[48.3%(29/60)]、大结节[26.7%(16/60)]、任何形式空洞[93.3%(56/60)]、胸腔积液[40.0%(24/60)]的发生率明显高于未并发组患者[分别为28.3%(17/60)、11.7%(7/60)、76.7%(46/60)、20.0%(12/60)](χ^2=5.08,P=0.024;χ^2=4.36,P=0.037;χ^2=6.54,P=0.011;χ^2=5.71,P=0.017),而支气管扩张[45.0%(27/60)]的发生率明显低于未并发组[70.0%(42/60)](χ^2=7.67,P=0.006);且并发组患者中的段性或叶性实变累及叶数[(0.78±0.96)个]、大结节累及肺叶数[(0.48±0.96)个]和任何形式空洞累及叶数[(2.05±1.43)个]明显多于未并发组[分别为(0.38±0.72)个、(0.13±0.39)个、(1.58±1.43)个](U=1380.50,P=0.011;U=1511.00,P=0.027;U=1432.00,P=0.046),而支气管扩张累及肺叶数[(0.97±1.37)个]明显少于未并发组[(1.58±1.57)个](U=1335.50,P=0.010)。结论耐多药肺结核并发糖尿病患者CT扫描出现段以上肺实变的频率及分布范围、出现大结节和空洞的频率及累及范围、并发胸腔积液的频率均较未并发糖尿病患者高;而支气管扩张多见于未并发糖尿病患者。 展开更多
关键词 结核 结核 抗多种药物性 糖尿病 共病现象 体层摄影术 X线计算机 疾病特征
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2019年中国新媒体研究的八大议题 被引量:20
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作者 李多 彭兰 《全球传媒学刊》 CSSCI 2020年第1期15-36,共22页
关于新媒体的社会影响的研究,一直是新媒体研究领域的重要方面。2019年,新闻传播学者在这一领域的研究也在继续拓展,这既包括社交媒体使用倦怠、使用沟、圈层化、数字劳工等新研究话题的开拓,也包括短视频、网络直播、网络空间治理、隐... 关于新媒体的社会影响的研究,一直是新媒体研究领域的重要方面。2019年,新闻传播学者在这一领域的研究也在继续拓展,这既包括社交媒体使用倦怠、使用沟、圈层化、数字劳工等新研究话题的开拓,也包括短视频、网络直播、网络空间治理、隐私权等方面研究的深化。学者们从新媒体对人的行为习惯、生活方式、社会结构、劳动关系以及社会治理的影响等不同视角,从深层探讨了人与新媒体技术的共生关系,以及新媒体影响下的社会变迁。 展开更多
关键词 社交媒体使用倦怠 使用沟 圈层化 数字劳工 短视频 网络直播 互联网治理 隐私权
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基于模糊自适应脉宽调制的双反馈控制算法 被引量:2
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作者 多丽 刘义艳 程绍峰 《探测与控制学报》 CSCD 北大核心 2017年第6期87-92,共6页
针对传统的双反馈控制对于系统控制有超调过大,跟随误差较大等问题,提出了一种模糊自适应脉宽调制(Pulse Width Modulation,PWM)控制的双反馈控制算法。该算法通过模糊自适应控制器与PWM变换器相结合,对双反馈系统实现了高精度高鲁棒性... 针对传统的双反馈控制对于系统控制有超调过大,跟随误差较大等问题,提出了一种模糊自适应脉宽调制(Pulse Width Modulation,PWM)控制的双反馈控制算法。该算法通过模糊自适应控制器与PWM变换器相结合,对双反馈系统实现了高精度高鲁棒性的控制。仿真实验表明,模糊自适应PWM的双反馈控制算法系统可更好地抑制超调以及具有更小的跟随误差。 展开更多
关键词 双反馈控制 模糊自适应控制器 跟随误差 超调量
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Combination of chemotherapy and immunotherapy for colon cancer in China: A meta-analysis 被引量:31
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作者 Zheng-Xu Wang Jun-Xia Cao +6 位作者 Zhi-Ping liu Yu-Xin Cui Chun-Yun li duo li Xiao-Yan Zhang Jin-Long liu Jun-li li 《World Journal of Gastroenterology》 SCIE CAS 2014年第4期1095-1106,共12页
AIM: To investigate whether autologous dendritic cell (DC)-cytokine-induced killer (CIK) cell therapy is able to improve the therapeutic efficacy of chemotherapy in colon cancer.
关键词 Dendritic cells Cytokine-induced killer cells META-ANALYSIS Colon cancer IMMUNOTHERAPY
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抑制视网膜色素上皮细胞发生上皮-间充质转化的研究进展
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作者 李铎 沈涵 +1 位作者 袁松涛 刘庆淮 《国际眼科杂志》 CAS 北大核心 2018年第12期2160-2164,共5页
视网膜色素上皮细胞(retinal pigment epithelium,RPE)的上皮间充质转化(epithelial-mesenchymal transition,EMT)是增殖性玻璃体视网膜疾病(proliferative vitreoretinopathy,PVR)的主要发病机制,也是治疗脉络膜新生血管(choroidal neo... 视网膜色素上皮细胞(retinal pigment epithelium,RPE)的上皮间充质转化(epithelial-mesenchymal transition,EMT)是增殖性玻璃体视网膜疾病(proliferative vitreoretinopathy,PVR)的主要发病机制,也是治疗脉络膜新生血管(choroidal neovascularization,CNV)时,造成抗血管内皮生长因子(anti-vascular endothelial growth factor,anti-VEGF)疗效降低的重要因素。除此之外,随着细胞替代治疗作为年龄相关性黄斑变性(age-related macular degeneration,ARMD)的新型治疗方式而兴起,人类胚胎干细胞(hESC-RPE)、体细胞诱导多能干细胞(iPSC-RPE)定向诱导分化的RPE细胞以及来自于流产胎儿的胎儿视网膜色素上皮细胞(fetal RPE,fRPE)逐渐受到了研究者们的关注。为了发挥最好的治疗效果,保证治疗用细胞的稳定增殖及高效分化是极其重要的。但是在传代扩增的过程中,由于上皮间充质转化的存在,导致这些细胞出现增殖困难以及再分化能力下降,从而影响治疗效果并阻碍了治疗人群的普及,使细胞替代治疗难以推广。所以,鉴于上皮间充质转化在视网膜疾病的发生和治疗中都造成了重要影响,抑制视网膜色素上皮细胞发生上皮间充质转化就显得尤为重要,为此,我们将阻止上皮间充质转化研究的最新进展综述如下。 展开更多
关键词 视网膜色素上皮细胞 上皮间充质转化 综述
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Research on Migration Features of Ammonia-Nitrogen in Shallow Groundwater of Coastal Area of Tangshan Fengnan
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作者 duo li Kang CHEN 《Journal of Groundwater Science and Engineering》 2014年第1期39-43,共5页
The ammonia-nitrogen in shallow groundwater of coastal area of Tangshan Fengnan exceeds the content limit at varying degrees. To analyze the the migration features of ammonia-nitrogen in the groundwater, a two-dimensi... The ammonia-nitrogen in shallow groundwater of coastal area of Tangshan Fengnan exceeds the content limit at varying degrees. To analyze the the migration features of ammonia-nitrogen in the groundwater, a two-dimensional groundwater flow and quality model has been established on the basis of investigation and analysis of hydeogeological conditions in this region. Ammonia-nitrogen in the first aquifer groundwater migrates slowly and is difficult to diffuse during the migration process for the low exploitation, the small hydraulic gradient, the relatively fine aquier rock particles and poor permeability of the aquifer. 展开更多
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Projective Bundles and Blowing-Ups Ⅱ
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作者 duo li 《Algebra Colloquium》 SCIE CSCD 2024年第1期57-62,共6页
We study the blowing-up X of a smooth projective variety X along a smooth center B that is equipped with a projective bundle structure over a variety Z.If the Picard number p(X)is 1 and dim X is at most 4,we classify ... We study the blowing-up X of a smooth projective variety X along a smooth center B that is equipped with a projective bundle structure over a variety Z.If the Picard number p(X)is 1 and dim X is at most 4,we classify all such pairs(X,B).If X is a projective space P_(n)(n≥5)and dim B is 2,we show that B is a linear subspace in X. 展开更多
关键词 BLOWING-UP projective bundle Fano bundle
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Synthesis and Characterization of Ordered Meso-Macro-Porous Silica Membranes on a Porous Alumina Support 被引量:1
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作者 duo li Y.S. lin V.V. Guliants 《Tsinghua Science and Technology》 SCIE EI CAS 2010年第4期377-384,共8页
Macroporous silica materials with ordered three-dimensional pore structure can be easily prepared by the template-directed sol-gel process. However, it is still a challenge to prepare them in membrane form on a porous... Macroporous silica materials with ordered three-dimensional pore structure can be easily prepared by the template-directed sol-gel process. However, it is still a challenge to prepare them in membrane form on a porous support, which limits their applications. In this work, we have demonstrated the feasibility of ob- taining a three-dimensional ordered macroporous silica membrane on macroporous alumina support using poly-methyl methacrylate (PMMA) spheres as the template. PMMA spheres were packed on the top of an Anopore-alumina support by filtration of a PMMA aqueous suspension. Silica sol obtained by an acid-catalyzed sol-gel process was infiltrated into the voids among the spheres. Drying induced stress caused the membrane to crack or peel off from the top of the support. This can be minimized by annealing the PMMA template layer before the introduction of silica sol which increases the mechanical strength of the template. Calcination or solvent extraction to remove the template produced a highly ordered three-dimensional macroporous silica membrane with spherical pores connected by windows in the mesoporous range. The results show that the PMMA-templated infiltration method is effective in preparing three-dimensional ordered macroporous silica membranes on a porous support. 展开更多
关键词 MACROPOROUS ORDERED SILICA MEMBRANE
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