88 research outputs found

    壳聚糖絮凝法处理明黄膏提取液的研究

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    甘肃省自然科学基金暨中青年科技基金项目 (项目编号YS 0 11 A2 3 0 15

    HBeAg特异免疫复合物检测及临床意义

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    采用单克隆抗-HBe固相ELISA法检测118例HBV感染者血清中HBeAg特异免疫复合物(HBeAg/IC),结果表明∶HBeAg/IC与HBV复制相关,可作为HBV复制的一种血清学标志,HBeAg阴性、HBVDNA阳性者中,62.2%患者HBeAg/IC阳性,提示HBeAg/IC的形成致使夹心法不能检出HBeAg,这类患者仍可以是HBV野毒株感染,并非均为HBeAg缺陷变异株感染;HBeAg/IC阳性血清ALT异常率明显高于HBeAg/IC阴性血清(P<0.01),提示HBeAg/IC存在与肝损伤有关

    Control method for aircraft wake vortex based on Rayleigh-Ludwig instability

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    在飞机飞行的过程中尾涡会伴随着升力产生,威胁后机的飞行安全.在简化机翼模型上添加扰流片,通过一个矩形翼以引入一个与主翼尾涡大小不同、方向相反的小涡,构建尾流自消散四涡系统,以期诱发尾涡的rAylEIgH-ludWIg相交不稳定性.通过改变扰流片的大小形状,调整模型的攻角和拖曳速度,采用粒子图像速度场仪测量系统定量研究在低雷诺数下单主翼尾涡发展特性以及双涡相互作用特性.研究表明:在未添加扰流片时,尾涡环量在45个翼展内相对于初始环量基本保持不变;在添加扰流片的情况下尾涡的环量衰减可以达到35%~55%,而未添加的基本翼型的尾涡的环量则几乎保持不变,这说明添加适当的扰流片能诱发尾涡的rAylEIgH-ludWIg相交不稳定性,加速尾涡的消散,当小涡和主涡的初始环量比为-0.489、初始距离比为0.5时,45个翼展范围内,尾涡环量衰减55.9%.本文系统性的实验结果可以为低尾流机翼的设计提供参考依据.The aircraft wake vortex is an inherent flow phenomenon due to the lift generation mechanism,which has a negative impact on the flight safety.By adding a set of specially designed spoiler,a rectangular wing was designed to generate a pair of weaker vortices,which had different sizes and opposite direction compared to main wing vortices,thereby constructing a self-destructive four-vortex wake system to induce Rayleigh-Ludwig instability.Under different experimental conditions,in terms of changing the size or shape of the spoiler,towing speed and angle of attack,the wake vortex development of the test model,that both with and without spoiler,as well as the circulation analysis,were acquired particle image velocimetry( PIV) measurements under the low Reynolds number.The study demonstrates that the decrease in circulation was 35% to55% in 45 wingspans when spoilers are introduced,whereas the counterpart of the baseline airfoil,without spoilers,is nearly kept steadily,which reveal the application possibility of Rayleigh-Ludwig instability in alleviating the wake vortex.As the initial circulation ratio equals to- 0.489 and the initial distance ratio is0.5,the circulation of the primary vortex reduce most significantly( 55.9%) in 45 wingspans.Results would provide a scheme in the design of airfoils with weaker vortices.国家自然科学基金(11072206

    Comparative study on the adhesive capabilities of sodium alginate and guar gum as bone adhesives

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    目的比较研究海藻酸钠和瓜儿胶作为骨骼黏合材料的黏合性能。方法通过测定两种胶体的动力黏度、固化时间和对钙离子的作用,探讨相应的黏合性能。结果瓜儿胶的黏度较高,能适应多种形式的补钙剂,但其固化性能还有待改进;海藻酸钠固化性能优越,能在瞬间完成固化,但其黏度比瓜儿胶低,只能适应非离子钙型的补钙剂。结论海藻酸钠和瓜儿胶都是较有潜力的天然骨骼黏合剂。 【英文摘要】 Objective To comparatively investigate the adhesive capabilities of sodium alginate and guar gum as bone adhesives.Methods The adhesive capabilities were analysed and discussed by measuring their kinetic viscosities,solidification time and the reaction with calcium ions.Results Guar gum had higher kinetic viscosity and could fit to the supply of both ion calcium and non-ion calcium for the bone cure,but its capability of solidification need to be improved.Sodium alginate had higher solubility and its solidi...卫生部科学研究基金-福建省卫生教育联合攻关计划项目(No.WKJ2005-2-018

    Study of the Interaction of Disubstituted Cucurbit[6]uril with 2-(Aminomethyl)pyridine

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    分别用核磁共振、紫外可见吸收和X射线单晶衍射方法研究对称四甲基六元瓜环与2-氨基甲基吡啶的相互作用及其结构特征.1HNMR谱图和紫外可见吸收光谱图清晰表明,2-氨基甲基吡啶与对称四甲基六元瓜环有明显的相互作用,客体2-氨基甲基吡啶的吡啶环部分进入了瓜环空腔,1HNMR谱图相关质子峰的积分强度以及客体吸光度随主体瓜环浓度变化明确表示它们之间形成了1∶1的包结配合物,此包结比并不随瓜环的浓度增加而改变.X射线单晶衍射法对包结配合物晶体的测定进一步证实了核磁共振、紫外可见吸收方法所得结论.Interaction and structure of a host-guest inclusion complex of symmetrical tetramethyl substi- tuted cucurbit[6]uril (TMeQ[6]) with 2-(aminomethyl)pyridine (amp) have been studied by using 1H NMR technique, UV-visible spectrophotometry and single crystal X-ray diffraction determination. The experimen- tal results from 1H NMR and UV-visible spectra revealed that the amp as a guest enters into the cavity of TMeQ[6] to form a host-guest inclusion complex of TMeQ[6] and amp with a constant ratio of 1∶1. The single crystal X-ray diffraction determination further confirmed the conclusions.国家自然科学基金(Nos.200261002,20362003);; 科技部国际科技合作重点计划(No.2003DF000030);; 贵州省省长资金;; 贵州省教育厅自然科学研究资助项目

    Investigation of Structures of the Self-assembled Pseudorotaxane of Cucurbiturils with Some Alkyldiamines

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    以1H核磁共振技术和X射线单晶衍射分析方法考察了 3种瓜环与长链二胺 ( 1,7 庚二胺与 1,8 辛二胺 )相互作用的结构特征 .1HNMR分析表明瓜环 (Q[6]和Q[7] )与有机二胺 ( 1,7 庚二胺与 1,8 辛二胺 )有较强的相互作用 ,形成自组装类轮烷结构 ;Q[8]与 1,7 庚二胺与 1,8 辛二胺之间相互作用力相对较弱 ;晶体结构测定结果表明 ,六元瓜环与辛二胺自组装形成的类轮烷实体中 ,辛二胺是以直链状穿过六元瓜环的空腔 ,两配位氨基留在瓜环两端口之外 .The structures of self-assembled pseudorotaxane of cucurbit[n]urils(n=6~8) with some alkyldiamines have been investigated by 1H NMR technique and single crystal X-ray diffraction method. The results reveal that the interaction between cucurbit[6]uril or cucurbit[7]uril and 1,7-diaminoheptane or 1,8-diaminooctane is stronger than that between cucurbit[8]uril and 1,7-diaminoheptane or 1,8-diaminooctane, and the pseudorotaxanes of cucurbit[n]urils with the alkyldiamines were observed. Particularly, in the pseudorotaxane of cucurbit[6]uril with 1,8-diaminooctane, the amino groups of 1,8-diaminooctane are left outside the ports of cucurbit[6]uril.国家自然科学基金(No.200261002);; 贵州省重点基金(No.20023004);; 贵州省国际合作(No.200211003)资助项目

    SDF-1α/CXCR4信号通路对轴向应力刺激促进骨再生中影响的实验研究

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    目的 通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived-factor-1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制。方法 取72只雄性新西兰大白兔,于右后肢胫骨近端内侧制备直径8 mm圆形皮质骨缺损并脱蛋白松质骨支架修复模型后,随机分为3组(n=24)。A组腹腔注射PBS,B组术肢给予应力刺激治疗+腹腔注射PBS,C组术肢给予应力刺激治疗+腹腔注射CXCR4拮抗剂(AMD3100)。术后2、4、8、12周,摄X线片并采用Lane-SandhuX线评分标准评价骨愈合情况,取标本行HE染色观察新生骨组织及支架降解,免疫组织化学染色观察VEGF、CXCR4表达水平;4、8周取标本Western blot检测SDF-1α及CXCR4蛋白表达水平。12周行Micro-CT检查,计算新生骨体积及新生骨密度。结果 X线片检查示,除术后2周各组骨缺损区及支架无明显变化外,4、8及12周时B组骨愈合评分均优于A、C组(P<0.05)。12周时Micro-CT扫描可见B组骨缺损修复、髓腔再通,新生骨体积及骨密度均高于A、C组(P<0.05)。HE染色显示,术后4周开始B组骨再生及支架降解均明显快于A、C组。免疫组织化学染色示,各组VEGF及CXCR4阳性表达均在4周时达峰值;各时间点B组VEGF及CXCR4表达量均显著高于A、C组(P<0.05)。Western blot检测显示,4、8周时B组SDF-1α与CXCR4表达量均显著高于A、C组(P<0.05)。结论 轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达SDF-1α,激活与其下游调控BMSCs募集的CXCR4信号有关

    SDF-1α/CXCR4信号通路在轴向应力刺激促进骨再生中的作用研究

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    目的通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived factor 1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制。方法取72只雄性新西兰大白兔,于右后肢胫骨近端内侧制备直径8 mm圆形皮质骨缺损并脱蛋白松质骨支架修复模型,随机分为3组(n=24)。A组腹腔注射PBS,B组术肢给予应力刺激治疗+腹腔注射PBS,C组术肢给予应力刺激治疗+腹腔注射CXCR4拮抗剂(AMD3100)。术后2、4、8、12周,摄X线片并采用Lane-Sandhu X线评分标准评价骨愈合情况,取标本行HE染色观察新生骨组织及支架降解,免疫组织化学染色观察VEGF、CXCR4表达水平;4、8周取标本Western blot检测SDF-1α及CXCR4蛋白表达水平;12周行Micro-CT检查,计算新生骨体积及新生骨密度。结果 X线片检查示,除术后2周各组骨缺损区及支架无明显变化外,4、8及12周时B组骨愈合评分均高于A、C组(P<0.05)。12周时Micro-CT扫描可见B组骨缺损修复、髓腔再通,新生骨体积及骨密度均高于A、C组(P<0.05)。HE染色显示,术后4周开始B组骨再生及支架降解均明显快于A、C组。免疫组织化学染色示,各组VEGF及CXCR4阳性表达均在4周达峰值;各时间点B组VEGF及CXCR4表达量均显著高于A、C组(P<0.05)。Western blot检测显示,4、8周时B组SDF-1α与CXCR4表达量均显著高于A、C组(P<0.05)。结论轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达SDF-1α,激活与其下游调控BMSCs募集的CXCR4信号有关。国家自然科学基金资助项目(81401783);;\n福建省自然科学基金资助项目(2016J05208);;\n军队后勤科研项目基金(CNJ16C013);;\n军队青年医学科技培育项目(19QNP046)~

    SDF-1α/CXCR4信号通路在轴向应力刺激促进骨再生中的作用研究

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    目的 通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived-factor-1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制..

    对称四取代六元瓜环的合成及其2,2-联吡啶主客体化合物

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    利用二甲基取代甘脲的二醚与甘脲二聚体成功合成了新型取代六元瓜环——对称四甲基六元瓜环. 该瓜环的结构已被晶体结构鉴定、核磁共振谱以及质谱方法所证实, 分子中所含两个二甲基取代甘脲处于对位. 1H NMR表明该瓜环容易与吡啶衍生物形成主客体配合物
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