155 research outputs found

    具有单参数空间对称群的向量场及其约化

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    对于保持某n-形式的n维向量场,应用Lie群的方法得到结论:当这类向量场有保持n-形式的空间参数对称群时,可具体地构造出一个与该向量场无关的变换,它不仅使向量场约化掉一维,并且使得约化向量场保持相应的(n-1)-形式。特别,当n=3时,简单地得到了Mezie和Wiggins最近得到的重要结果

    Development of interleukin-21 as a therapeutic drug

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    白细胞介素21; (IL-21)是一种具有多效免疫调节活性的细胞因子,参与先天性免疫反应和适应性免疫反应的多个环节,与自身免疫性疾病、肿瘤、病毒感染等疾病的发病过; 程相关。研究表明,在动物模型中通过增强或抑制IL-21的生物学功能对多种疾病具有治疗意义,多项以重组人IL-21为受试药物的临床试验已经开展。本; 文就IL-21的生物学功能,以及IL-21作为生化药物在临床治疗中的研究进展和应用前景进行阐述。Interleukin-21 (IL-21) is a cytokine with broad pleiotropic actions that; plays an important role in both innate and adaptive immune responses.; IL-21 participates in pathogenesis processes of many diseases, such as; autoimmune disease, tumor, virus infections and so on. Enhancing or; inhibiting the activity of IL-21 has shown to have certain therapeutic; effects in animal models of a wide range of diseases. Various clinical; trials using recombinant human IL-21 as drug candidates are on-going; towards the development of IL-21 as a therapeutic drug. This article; reviewed the biological function and research progress and application; prospect of IL-21 as a biochemical drug in clinical treatment

    镓在抗菌方面的研究进展

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    抗生素发现\"黄金时代\"的结束以及日趋严重的抗生素耐药性问题给我们留下一个戏剧性的、缺乏新型药物来防治耐药病原体感染的难题。这使得从现有非抗生素药物中筛查抗菌活性药物成为一种新尝试。近期研究表明:美国食品药品监督管理局(FDA)批准的、本来用于治疗高血钙的药物硝酸镓具有良好的抗菌活性。不同于其他抗生素,镓的药理性质依靠化学拟态,它可以在目标酶分子中取代铁,从而干扰、扰乱细菌含铁蛋白的功能及细菌代谢,无论是在体外实验还是在体内实验中,镓对多种病原体,包括多重耐药病原体都表现出杀菌活性。因此一些含镓制剂有望被开发成有潜力的非传统抗菌药物,帮助治疗多重耐药细菌感染。国家自然科学基金(No.81673242、No.81473251、No.31741006、No.31370166和No.81301474);;福建省自然科学基金(No.2014J01139和No.2015J01345);;厦门大学校长基金(No.20720160060

    Significado político-constitucional do direito penal

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    Através do Direito Penal o Estado ganha o poder de retirar da pessoa humana os direitos constitucionalmente assegurados, quais sejam: vida, liberdade e patrimônio, configurados como cláusulas pétreas da Constituição. O que se atinge no Direito Penal são os bens assegurados pela Carta Política, cuja aplicação e interpretação devem ser feitas em consonância com os Princípios Constitucionais. A discussão aqui empreendida quer demonstrar que, além do caráter técnico-dogmático, o Direito Penal tem um caráter político e este é o condicionante do objeto e do método do Direito Penal, fazendo com que os mesmos apresentem uma relação substancial com os princípios constitucionais

    Study on production of liquid hydrocarbon fuels from sorbitol and mannitol

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    在温和条件下研究了氢碘酸还原生物质基多元醇制备液体燃料的过程,使用气相色谱质谱仪(GC-MS)和红外光谱仪(FT-IR)分析了产物组成。结果表明,山梨醇和甘露醇为原料制备的液体产物中主要成分是C_(12)H_(16)、C_(12)H_(18)、C_(12)H_(20)、C_(12)H_(22)和C_(18)H_(26)等烃类物质。通过与碱的醇溶液反应将副产物碘代烷转化为烃,经旋转蒸发和减压蒸馏获得纯净的高碳烃产品。山梨醇、甘露醇以及二者混合物制备出的高碳烃的产率分别是81.1%、73.2%和77.3%。本研究获得的高碳烃产品是一种有前景的液体燃料,其含水量为0.1%,密度为0.83~0.84 g·mL~(-1),含氧量为2.0%~2.2%,热值均高于42 MJ·kg~(-1)。This paper describes the process of sorbitol and mannitol conversion to liquid heavier hydrocarbons via reduction with hydroiodic acid under mild reaction conditions. The compositions of the obtained products were analyzed using gas chromatography mass spectrometer( GC-MS) and Fourier transform infrared spectrometer( FT-IR). It is found that the products obtained from C6 polyols were mainly C_(12)H_(16),C_(12)H_(18),C_(12)H_(20),C_(12)H_(22) and C_(18)H_(26). The yields of heavier hydrocarbons from sorbitol,mannitol,and the mixture of sorbitol and mannitol were 81. 1%,73. 2%,and 77. 3%,respectively.To obtain pure hydrocarbon fuels,the obtained crude oil was treated with potassium hydroxide in an alcohol solution followed by rotary evaporation and vacuum distillation. The final liquid hydrocarbons obtained have a water content of 0. 1%,densities of 0. 83 ~ 0. 84 g·mL~(-1),oxygen content of 2. 0% ~2. 2%,and heating values > 42 MJ·kg~(-1) at room temperature,which is potentially a good transportation fuel for diesel replacement.国家自然科学基金项目(21276214

    Separation and Enrichment of Melamine in Feed by a New Molecular Imprinting Solid-phase Extraction Column

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    [目的]研制一种新型的分子印迹固相萃取小柱,用于分离富集饲料中的三聚氰胺。[方法]采用本体聚合法制备了三聚氰胺分子印迹聚合物,以该聚合物为填料制作三聚氰胺分子印迹固相萃取(MIP-SPE)小柱,优化了固相萃取条件,应用高效液相色谱(HPlC)法测定浓缩液中的三聚氰胺含量。[结果]自制的MIP-SPE小柱可以从饲料中选择性地分离、富集三聚氰胺,有效地去除饲料中的复杂基质,加标回收率约为95%。MIP-SPE小柱与空白印迹固相萃取小柱(nMIP-SPE)的对比试验表明,前者的萃取效率明显高于后者。[结论]自制的新型三聚氰胺MIP-SPE小柱可用于饲料提取液中的三聚氰胺高选择性分离富集,使用简便,具有广阔的应用前景。[Objective] The research aimed to develop a new molecular imprinting solid-phase extraction column for the separation and enrichment of melamine in feed.[Method] The molecular imprinting polymer of melamine was prepared by noumenon polymeric method.This polymer was used as filler to prepare molecular imprinting polymer solid-phase extraction(MIP-SPE) column of melamine.The solid-phase extraction conditions were optimized and melamine content in concentrated solution was determined by using HPLC.[Result]Melamine could be separated selectively from feed and enriched by home-made MIP-SPE column.It could wipe off complex matrix from feed and the addition recovery rate was 95%.The contrast experiment between MIP-SPE column and NMIP-SPE(non-imprinted polymer-solid phase extraction) column showed that the extraction efficiency of the former was obviously higher than the latter.[Conclusion] The home-made MIP-SPE column could be used to separate and enrich melamine in feed efficiently,with a broad application prospect.厦门市科技计划项目(3502Z20110018

    Experimental study on effect of Changrun Formula in regulating expression of AQP3 and AQP9 in colon mucosa of functional constipation rats

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    目的:观察肠润方对功能性便秘模型大鼠结肠黏膜AQP3、AQP9表达的影响,探究其调控AQP3、AQP9表达的分子机制。方法:60只SD大鼠随机分为空白组、模型组、阳性对照组(麻仁丸组)、肠润方组、肠润方联合P38MAPK抑制剂SB203580组。用复方地芬诺酯制造大鼠便秘模型,采用免疫组织化学及实时荧光定量PCR(q RT-PCR)检测大鼠便秘模型近端及远端结肠黏膜AQP3、AQP9的表达;Western Blot检测信号传导通路相关分子P38MAPK及P-P38MAPK的表达。结果:造模成功后,模型组近端结肠黏膜AQP3表达较空白组明显上升,而远端结肠黏膜AQP9表达较空白组明显下降(t值分别为3.148和7.069,P值均0.05)。肠润方联合P38MAPK抑制剂SB203580治疗后,近端结肠黏膜AQP3 m RNA水平显著上升(t=5.922,P0.05). The level of AQP3 m RNA in proximal colonic mucosa was significantly increased(t=5.922, P<0.01), and AQP9 m RNA was significantly decreased in distal colonic mucosa(t=4.038, P<0.01); The relative expression of P-P38/P38 protein was significantly decreased(t=19.419, P<0.01). Conclusion: The therapeutic action ofChangrun Formula on functional constipation rat models might through inhibiting the expression of AQP3 in proximal colon, and accelerating on expression of AQP9 in distal colon, and the regulating mechanism might relate with the inhibition on P38 MAPK and AKT phosphorylation.福建省自然科学基金项目(No.2012D043)~

    高效液相色谱-质谱法同时测定猪尿中克伦特罗和莱克多巴胺

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    克伦特罗和莱克多巴胺同属于β_2-肾上腺素受体激动剂(简称β_2-兴奋剂),能够改善动物养分的代谢途径,促进动物肌肉的合成,抑制脂肪合成的积累,因此常被不法分子添加于动物饲料或饮用水中,以提高胴体瘦肉率。由于其易在动物肝脏中积聚残留,并通过食物链进入人体。人类食用后,可能出

    星状神经节阻滞用于慢性主观性耳鸣困扰的辅助干预效果及预测指标初析

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    目的探讨星状神经节阻滞(SGB)用于慢性主观性耳鸣困扰的辅助干预效果,及相应的预测指标,为SGB应用于耳鸣的临床干预累积经验。方法回顾因其他干预方案效果不理想而在中山大学附属第三医院耳鼻咽喉-头颈外科接受SGB干预的慢性主观性耳鸣患者资料。SGB干预前进行耳鸣残疾量表(THI)评估、纯音听阈测试、耳鸣响度评估,部分患者接受了睡眠质量(PSQI)评估。SGB干预后复测THI,以评价SGB的干预效果。随后,通过相关分析及线性回归方程探寻预测SGB干预效果的潜在指标。数据的统计分析采用SPSS 24.0进行,P &lt; 0.05表示存在统计学意义。结果至2023年04月,共有107名慢性主观性耳鸣患者接受了SGB干预,其中男性患者67名,女性患者40名,平均(45.32±11.40)周岁,耳鸣持续(20.32±24.64)月[16(12~20)]。有7名患者因个人原因中途退组,退组率6.54%,干预依从性良好。所有患者均未出现穿刺部位感染、血肿、神经损伤、局麻药中毒等不良反应,安全性良好。SGB干预后,有77名患者的THI得分下降至36分及以下,剩余的患者中有12名的THI得分下降幅度达到10分及以上,有效率为89%;配对样本t检验显示,SGB干预前后的THI得分有显著的统计学差异(t = 15.575,P &lt; 0.001),干预效果良好。皮尔逊相关分析显示,干预前的THI得分和耳鸣主观响度与THI的改善水平呈显著的正相关关系(P &lt; 0.05);进一步的逐步线性回归分析发现,“干预前THI得分”具有显著的统计学意义(P &lt; 0.001),回归系数为0.308,预测了THI改善水平的17.4%。结论SGB干预慢性主观性耳鸣困扰的短期效果良好、安全性高,可用于常规干预方案不理想时(尤其是THI得分较高患者)的补充方案,但后续研究需要明确长期疗效及内在机制,为SGB应用于主观性耳鸣的干预奠定更为扎实的理论基础

    A Comparative Study on IPO’s Initial Returns in A Share Market between Pre-reform of Equity Division and Post-reform

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    本文采用股权分置改革前后的新股样本数据,对影响我国A股初始收益率的相关因素展开实证分析。研究发现,股权分置和发行管制是造成股权分置改革前A股IPO市场高初始收益率的根本原因,而在股权分置改革后,由于发行继续受到严格管制和投资者旧有定价理念及盈利模式的延续,新股的初始收益率仍然存在继续高企的制度基础和市场条件。因此,在股权分置改革后,管理层应进一步推进发行监管制度改革,实现股票供给市场化。The paper empirically analyzes the factors affecting the A share initial returns through the sample data before and after the Reform of the Share Splitting.The results show that the share splitting and the issue regulatory are the essential reasons to cause the high initial returns of the A shares before the reform of the share splitting.After the share splitting reform, the initial returns of the A share are high because of the system basis and the market condition.Therefore, the management administration ought to reform the issuing supervision system and make the stock supply adjusted by market.教育部人文社会科学基金项目(08JC790089);福建省软科学项目(2009R0079)的资
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