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Immobilization and Properties of Lipase from Candida rugosa on Electrospun Nanofibrous Membranes with Biomimetic Phospholipid Moities

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Chemical Research in Chinese Universities 2008年第2期24卷 231-237页

作者： HUANG Xiao-jun YU An-guo GE Dan xu Zhi-kang Institute of Polymer Science Key Laboratory of Macromolecular Synthesis and Functionalization of Ministry of Education State Key Laboratory of Chemical Engineering Zhejiang University Hangzhou 310027 P. R. China

Reported here is a protocol to fabricate a biocatalyst with high enzyme loading and activity retention, from the conjugation of electrospun nanofibrous membrane having biomimetic phospholipid moiety and lipase. To improve the catalytic efficiency and activity of the immobilized enzyme, poly（acrylonitrile-co-2-methacryloyloxyethyl phosphorylcholine）s（PANCMPCs） were, respectively, electrospun into nanofibrous membranes with a mean diameter of 90 nm, as a support for enzyme immobilization. Lipase from Candida rugosa was immobilized on these nanofibrous membranes by adsorption. Properties of immobilized lipase on PANCMPC nanofibrous membranes were compared with those of the lipase immobilized on the polyacrylonitrile（PAN） nanofibrous and sheet membranes, respectively. Effective enzyme loading on the nanofibrous membranes was achieved up to 22.0 mg/g, which was over 10 times that on the sheet membrane. The activity retention of immobilized lipase increased from 56.4% to 76.8% with an increase in phospholipid moiety from 0 to 9.6%（molar fraction） in the nanofibrous membrane. Kinetic parameter Km was also determined for free and immobilized lipase. The Km value of the immobilized lipase on the nanofibrous membrane was obviously lower than that on the sheet membrane. The optimum pH was 7.7 for free lipase, but shifted to 8.3-8.5 for immobilized lipases. The optimum temperature was determined to be 35 ℃ for the free enzyme, but 42-44℃ for the immobilized ones, respectively. In addition, the thermal stability, reusability, and storage stability of the immobilized lipase were obviously improved compared to the free one.

关键词： Biomimetic polymer Nanofibrous membrane Electrospinning Enzyme immobilization Lipase

Synthesis and Characterization of a Novel Acrylonitrile Copolymer Containing Glucose Pendants

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Chinese Chemical Letters 2003年第2期14卷 151-154页

作者： Dong Mei GUO Rui Qiang KOU Zhi kang xu Institute of Polymer Science Zhejiang UniversityHangzhou 310027

In this work, a novel sugar-containing copolymer was synthesized by the copolymerization of a-allyl glucoside (AG) with acrylonitrile (AN). The copolymers were characterized by NMR spectroscopy. It was found that acrylonitrile-based copolymers containing as high as 22wt.% of a-allyl glucoside can be synthesized by the free radical solution copolymerization of the two monomers in DMSO with AIBN as initiator.

关键词： a-Allyl glucoside acrylonitrile copolymerization sugar-containing copolymer.

First exit distribution and path continuity of Hunt processes

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Applied Mathematics(A Journal of Chinese Universities) 2009年第4期24卷 389-392页

作者： ZHANG Hui-zeng kang xu-sheng ZHAO Min-zhi School of Sciences Hangzhou Normal University Hangzhou 310036 China Department of Statistics and Computing Science Zhejiang University City College Hangzhou 310015 China Department of Mathematics Zhejiang University Hangzhou 310027 China

This paper gives a characterization of a Hunt process path by the first exit left limit distribution. It is also showed that if the first exit left limit distribution leaving any ball from the center is a uniform dist... 详细信息

关键词： first exit left limit distribution Hunt process Levy process Brownian motion

液质联用结合网络药理学探究少腹逐瘀汤抗宫颈癌活性机理

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应用化学 2024年第5期41卷 687-702页

作者：胡轩吴同川艾鑫丹何兴悦徐弘康郑飞越皓戴雨霖长春中医药大学吉林省人参科学研究院长春130117 长春中医药大学康复医学院长春130117

采用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(UHPLC-Q-Exactive Orbitrap MS)技术,结合网络药理学和分子对接,对少腹逐瘀汤发挥抗宫颈癌作用的重要成分、靶点和通路进行预测分析,并通过细胞实验初步探究其作用机制。经鉴定发现... 详细信息

采用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(UHPLC-Q-Exactive Orbitrap MS)技术,结合网络药理学和分子对接,对少腹逐瘀汤发挥抗宫颈癌作用的重要成分、靶点和通路进行预测分析,并通过细胞实验初步探究其作用机制。经鉴定发现苯丙素类、黄酮类、萜类、生物碱类、有机酸类、挥发油类、苯酞类、香豆素类、苯醛类、氨基酸类、酚类和其他类等共89种化合物,网络药理学和分子对接深入挖掘得到少腹逐瘀汤抗宫颈癌的7个重要成分、8个核心靶点和10条宫颈癌相关信号通路。细胞实验表明,给药组HeLa细胞与空白对照组相比,生存率逐渐降低,细胞凋亡率逐步提高,呈浓度依赖性(P<0.05)。少腹逐瘀汤可以提高Bax、Cyto c、Caspase 9和Caspase 3表达水平,降低PI3K、AKT和Bcl-2表达水平。少腹逐瘀汤可能通过槲皮素、芍药苷、黄芩素、山奈酚、沙立朴吩、丁香酚和鞣花酸等成分作用于TP53、AKT1和EGFR等靶点发挥抗宫颈癌作用,其机制与PI3K/AKT和Bcl-2家族蛋白信号通路的调控密切相关,充分体现了多成分、多靶点和多通路的特点。

关键词：少腹逐瘀汤超高效液相色谱-四极杆-静电场轨道阱高分辨质谱化学成分宫颈癌网络药理学

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基于物质流模型的规模化蛋鸡养殖场氨排放系数优化与实证研究

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环境科学学报 2024年第8期44卷 459-466页

作者：刘凡惠李笑晴张爱师荣光马田田张宇红康旭农业农村部环境保护科研监测所天津300191

确定科学准确的氨排放系数,是了解规模化养殖场氨气排放量、制定科学有效减排措施的重要基础.本研究在《大气氨源排放清单编制技术指南(试行)》的基础上,进一步考虑了不同粪污资源化处理方式的差异性,结合规模化畜禽养殖产污普查数据,... 详细信息

确定科学准确的氨排放系数,是了解规模化养殖场氨气排放量、制定科学有效减排措施的重要基础.本研究在《大气氨源排放清单编制技术指南(试行)》的基础上,进一步考虑了不同粪污资源化处理方式的差异性,结合规模化畜禽养殖产污普查数据,对氨排放系数核算相关参数进行优化,形成了我国六大地理区下的规模化蛋鸡养殖场NH3排放系数汇总.同时以华东区两家规模化蛋鸡养殖场的实测氨排放折算系数来验证优化前后的排放系数.实证研究表明,本研究在不同粪污管理环节、不同监测季节及全年平均的氨排放系数计算值与实测折算值的差异,总体上优于《指南》的计算结果,且本研究优化后的氨排放系数在全过程年均排放系数的计算结果上与实测折算系数一致度更高.本研究可为制定适合我国规模化畜禽养殖场尺度下的氨排放清单提供科学依据,推动养殖场氨减排策略的制定和精细化环境管理的革新.

关键词：规模化蛋鸡养殖场氨排放排放系数

Effect of Bt traits on transgenic rice's growth and weed competitiveness

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Journal of Integrative Agriculture 2023年第8期22卷 2346-2358页

作者： WANG kang-xu ZHANG Ke-rou CAO Cou-gui JIANG Yang College of Plant Science and Technology Huazhong Agricultural UniversityWuhan 430070P.R.China

Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with ***,whether the expression of the Bacillus thuringiensis(Bt)gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly ***,field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled *** showed that weed–rice competition in the direct-sowing(DS)field was earlier and more severe than that in the transplanting(TP)field,which resulted in a significant decrease in biomass and yield in ***,conventional Bt and non-Bt rice yield was not significantly *** weed number,weed coverage ratio,and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages,especially in DS plots,suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed *** yield and weed number varied between different hybrid rice lines,but those differences were insignificant between Bt and non-Bt *** number of insects increased with the increase of weeds in hybrid rice plots,whereas the insect number and diversity did not display a significant difference between Bt and non-Bt ***,the ecological risk of transgenic Bt rice is comparable to non-Bt rice.

关键词： biosafety field evaluation genetically modified crops Oryza sativa weed competitiveness

石羊河流域生态系统碳储量时空变化及多情景模拟

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中国环境科学 2024年第6期44卷 3365-3375页

作者：许澳康胡梦珺石晶孟祥云白清竹郭婧玲刘烁雅张嗣阳西北师范大学地理与环境科学学院甘肃省绿洲资源环境与可持续发展重点实验室甘肃兰州730070

以石羊河流域为例,利用InVEST模型评估1990~2020年土地利用变化带来的碳储量效应,耦合PLUS模型模拟2035年在自然发展、生态保护、水资源约束和经济发展情景下土地利用变化及其对碳储量的影响.结果表明:石羊河流域土地利用主要以未利用地... 详细信息

以石羊河流域为例,利用InVEST模型评估1990~2020年土地利用变化带来的碳储量效应,耦合PLUS模型模拟2035年在自然发展、生态保护、水资源约束和经济发展情景下土地利用变化及其对碳储量的影响.结果表明:石羊河流域土地利用主要以未利用地,草地和耕地为主,占流域总面积的93%.1990~2020年石羊河流域耕地,水域和建设用地面积呈增长趋势,其余用地面积呈减少趋势.2020~2035年多情景模拟下,只有生态情境中林地和草地面积增加显著.1990~2020年流域碳储量整体呈增长趋势,其中以草地,未利用地和耕地碳储量贡献为主,占碳总量的86%.2020~2035年4种情景下的碳储量均有所增加,但生态保护情景中碳储量增加最为显著,共增加3.75×10^(6)t.自然发展情景和经济发展情景下,林地和草地转为耕地的面积远大于转入,碳储量损失较多.水资源约束情景下,耕地主要转出为草地和建设用地,其他各地类之间转换所承载的碳储量基本平衡.生态保护情景下,林地,草地等生态用地转入面积大于转出使区域碳储量增加.研究结果以期为石羊河流域提升陆地生态系统碳储量和规划未来国土空间提供科学依据.

关键词：碳储量 InVEST模型 PLUS模型土地利用石羊河流域

探针结构对Ti/CuO微波点火延迟时间的影响

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火炸药学报 2024年第5期47卷 468-474,I0006页

作者：唐魁赵团唐振华陈小远程用泷陈苏杭沈瑞琪徐抗震西北大学化工学院/西安市特种能源材料重点实验室陕西西安710069 陕西应用物理化学研究所陕西西安710061 南京理工大学化学化工学院/微纳含能器件工业和信息化部重点实验室江苏南京210094

为了研究探针结构对微波点火性能的影响,使用4种探针对Ti/CuO点火药的微波点火延迟时间进行了测试,并通过模拟对探针结构进行优化,获得了探针参数(长度、包覆层厚度、尖端锥度和镀层厚度)对电场强度的影响规律。结果表明,探针针尖处的... 详细信息

为了研究探针结构对微波点火性能的影响,使用4种探针对Ti/CuO点火药的微波点火延迟时间进行了测试,并通过模拟对探针结构进行优化,获得了探针参数(长度、包覆层厚度、尖端锥度和镀层厚度)对电场强度的影响规律。结果表明,探针针尖处的电场强度显著影响点火延迟时间,在2.45 GHz、50 W微波作用下,探针1、2、3、4最大电场分别为1800、190、34和53 kV/m,Ti/CuO的点火延迟时间分别为222.6、660.5、949.1和921.3 ms;在2.45 GHz、1 W微波作用下,当探针长度为26 mm、PTFE包覆层长度为8 mm、厚度为0.75 mm、针尖锥度为0.243和金镀层厚度为5μm时,能够将电场强度从原来的约10 kV/m提升到约1000 kV/m,并且电场分布集中于尖端。

关键词：微波点火探针点火药点火延迟时间电场强度点火器件

A FACILE APPROACH FOR THE SURFACE MODIFICATION OF POLY(VINYLIDENE FLUORIDE) MEMBRANE VIA SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

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Chinese Journal of Polymer Science 2008年第1期26卷 105-110页

作者： Lei, Hao Yu, Hai-yin Lu, Ying Lu, Xiao-long xu, Zhi-kang Zhejiang Univ Minist Educ Inst Polymer Sci Hangzhou 310027 Peoples R China Zhejiang Univ Minist Educ Key Lab Macromol Synth & Functionalizat Hangzhou 310027 Peoples R China Tianjin Polytech Univ Inst Membrane Sci & Technol Ningbo 315211 Peoples R China

A novel approach for the surface modification of poly(vinylidene fluoride)(PVDF)membrane was successfully realized through alkaline treatment,UV-induced bromine addition,and followed by surface-initiated atom transfer radical polymerization(ATRP)of methyl methacrylate(MMA).Chemical changes on the PVDF membrane before and after modification were analyzed with attenuated total reflectance Fourier transform infrared spectroscopy(ATR/FT-IR)and X-ray photoelectron spectroscopy(XPS).Primary kinetic study revealed...

关键词： Poly(vinylidene fluoride) Alkaline treatment Bromine addition Atom transfer radical polymerization