检索结果-南通市图书馆

PURIFICATION AND CHARACTERIZATIO OF WATER-SOLUBLE POLYSACCHARIDES FROM THE SUBMERGED CULTURED MYCELIUM OF LENTINUS STRIGUELLUS

在线全文

学校读者我要写书评

暂无评论

PURIFICATION AND CHARACTERIZATIO OF WATER-SOLUBLE POLYSACCHA...

首届海峡两岸食（药）用菌学术研讨会

作者： LIN Yue-Xin HUANG yan-yan LAI ping xie Hua-Ling (Bioengineering College of Fujian Normal University, Fuzhou, 350007)

＜正＞Two fractions of water-soluble polysaccharide LS-Ⅰ and LS-Ⅱ-b were obtained from the submerged cultured mycelium of Lentinus striguellus by hot water extraction, ethanol precipitation, DEAE-cellulose chromatography and Sephadex G -100 gel filtration chromatography. Sephedex G -200 chromatography showed that they were purified into pure preparations. The molecular weight, monosaccharide constituent and glucosidic bond of the polysaccharides were tested by employing Sephadex G-100 chromatography, GC, IR and. NMR. The results were as below: Molecular weight: LS- Ⅰ 1.15×104Da;IS-Ⅱ-b 3.88×103Da. Monosaccharide composition: LS- I Ara:Fuc:Xyl:Fru:Man:Glc 0.04:0.02:0.06:2.78:0.67:1.79 LS-Ⅱ-b Fru:Man:Glc 2.99:0.83:5.51 Specific rotation [α]30（H2o）: LS-Ⅰ+63.33°LS-Ⅱ-b +73.67° IR and NMR examination showed that two polysaccharides were pyran type heteropolysacharides with a （1F332）,（1F334） glucosidic bonds （LS-Ⅰ）, and α（1→2）, 1→3) ,（1→4）glucosidic bonds （LS-Ⅱ-b）. The polysaccharides LS-Ⅱ-b contained a conjugated protein constituent.

关键词： Lentinus striguellus polysaccharide purification characterization.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

人地关系地域系统的三点理论研究

云南师范大学学报（哲学社会科学版） 2006年第1期38卷 55-59页

作者：邱膑扬鄢谢萍廖春花云南师范大学旅游与地理科学学院云南昆明650092 乐山师范学院旅游发展研究中心四川乐山614000

人地关系地域系统理论中的连接度与连结度、区域结构优劣的评价尺度、尺度效应三点对人地关系地域系统的结构与功能联系是十分紧密的,本文主要提出其概念、影响因子、两者的关系与数量化的计算及其实际意义;建立了一个新型的区域结构评... 详细信息

人地关系地域系统理论中的连接度与连结度、区域结构优劣的评价尺度、尺度效应三点对人地关系地域系统的结构与功能联系是十分紧密的,本文主要提出其概念、影响因子、两者的关系与数量化的计算及其实际意义;建立了一个新型的区域结构评价的测量指标体系;建立区域稳定性的时空尺度效应和区域复杂系统的尺度延展效应两个观测研究要点。

关键词：人地关系地域系统连接度与连结度区域结构评价尺度效应

Trinuclear gold-catalyzed site-selective alkylation of peptides

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期 249-256页

作者： Qing-Yun Fang Chengyihan Gu Yinghan Chen Wencheng yan Yong Liang Weipeng Li Chengjian Zhu Jie Han Jin xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词：

同方期刊数据库

福建政和晚侏罗世——早白垩世金矿床成因类型浅析

在线全文

学校读者我要写书评

暂无评论

世界有色金属 2019年第2期44卷 91-93页

作者：严卸平王波涛中国冶金地质总局二局福建福州350181

政和地区大地构造位于闽东火山断拗带与闽西北隆起带之间,形成了受构造控制的一系列金矿床。这些金矿床常赋存于中酸性岩体中,硫、氢氧同位素显示有大气降水的岩浆热液成因,成矿深度约2km。围岩蚀变及包裹体温度均指示为中低温,结合大... 详细信息

政和地区大地构造位于闽东火山断拗带与闽西北隆起带之间,形成了受构造控制的一系列金矿床。这些金矿床常赋存于中酸性岩体中,硫、氢氧同位素显示有大气降水的岩浆热液成因,成矿深度约2km。围岩蚀变及包裹体温度均指示为中低温,结合大地构造背景,可知晚侏罗-早白垩世金矿属浅成低温热液成因类型矿床。浅成低温热液矿床易被剥蚀,且常与斑岩矿床成体系共生,因此,政和地区上侏罗～下白垩统中酸性岩、斑岩区可能有较好成矿远景。

关键词：晚侏罗世~早白垩世金矿浅成低温热液政和福建

一种基于全局优化的Internet拥塞控制算法

在线全文

学校读者我要写书评

暂无评论

上海交通大学学报 2002年第9期36卷 1329-1332页

作者：张敬辕曹燕萍谢剑英上海交通大学自动化系上海200030

与传统的基于经验的 Internet拥塞控制算法不同 ,根据广域网络的数学模型 ,将拥塞控制转化为约束非线性规划的全局优化问题 ,并由此依据凸优化问题的解决方法 ,设计了满足收敛、稳定和公平性条件的速率迭代算法 ;依据网络层显示拥塞指... 详细信息

与传统的基于经验的 Internet拥塞控制算法不同 ,根据广域网络的数学模型 ,将拥塞控制转化为约束非线性规划的全局优化问题 ,并由此依据凸优化问题的解决方法 ,设计了满足收敛、稳定和公平性条件的速率迭代算法 ;依据网络层显示拥塞指示技术的支持 ,将速率迭代算法分为源端和路由器两部分 ,从而使该算法可以在 IP网络中实现 .

关键词：显示拥塞指示凸优化约束非线性规划 IP网络全局优化 Internet 拥塞控算法

G-凸空间内的广义S-R-KKM型定理及应用

在线全文

学校读者我要写书评

暂无评论

四川师范大学学报（自然科学版） 2003年第5期26卷 456-460页

作者：李艳丁协平四川师范大学数学与软件科学学院四川成都610066

在G 凸空间内引入了广义S R KKM型映像,并在非紧设置下建立了一类新的广义S R KKM型非空交定理.作为应用,证明了G 凸空间内一些新的极大极小不等式、鞍点定理和极大元存在定理.

关键词： G-凸空间广义S-R-KKM型映象转移紧闭值鞍点极大元

Inactivation of Alkaline Phosphatase from Pinctada fucata by 2,4,6-trinitrobenzensulfonic acid: a Kinetic Analysis of the Substrate Reaction and Involvement of a Critical Lysine Residue at the Active Site

在线全文

学校读者我要写书评

暂无评论

Inactivation of Alkaline Phosphatase from Pinctada fucata by...

第七届全国酶学学术讨论会

作者： Hong-Tao Chen, Zheng-yan Yu, Li-ping xie, Rong-Qing Zhang Center for Ocean Scineces and Engineering, Tsinghua University, Beijing 100084, P.R China. Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084

The tissue non-specific alkaline phosphatase from pearl oyster Pinctada fucata waschemically modified by a lysine specific reagent,2,4,6-trinitrobenzenesulfonic acid(TNBS).The completely modified enzyme lost 80%percent of its initial *** stoichiometrystudy using a Tsou’s plot showed that the inactivation was dependent upon modification ofonly one critical lysine residue.A substrate reaction analysis was used to investigate thekinetics of the inactivation *** results showed that the inactivation followed a

关键词： alkaline phosphatase Pinctada fucata TNBS chemical modification

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

G-凸空间内的抽象广义矢量平衡问题

四川师范大学学报（自然科学版） 2004年第3期27卷 234-237页

作者：李艳丁协平四川师范大学数学与软件科学学院四川成都610066

作为矢量变分不等式问题的一个重要发展方向 ,在G 凸空间内研究了一类抽象广义矢量平衡问题 (简称AGVEP) ,并利用广义S R KKM型定理 ,在非紧的G

关键词：抽象广义矢量平衡问题广义S-R-KKM型映像 G-凸空间

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 518-532页

作者： Conglin Wang Fangyuan Cheng Zhaoli Han Bo yan Pan Liao Zhenyu Yin Xintong Ge Dai Li Rongrong Zhong Qiang Liu Fanglian Chen ping Lei Department of Geriatrics Tianjin Medical University General HospitalTianjinChina School of Medicine Nankai UniversityTianjinChina Tianjin Neurological Institute TianjinChina

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor ***-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system *** this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying *** results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral ***,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory *** sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier *** with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these *** summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

关键词： AKT astrocyte blood-brain barrier cerebral edema exosomes human-induced pluripotent stem cells intracerebral hemorrhage neural stem cells neuroinflammation PI3K