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11.
甲基苯丙胺(MA)的毒性作用与多巴胺系统有密切关系,而大量研究表明胶质细胞源性神经营养因子(GDNF)是一种有效的多巴胺能神经营养因子,本文综述GDNF对多巴胺能神经元保护功能机制及用于治疗MA依赖的研究进展,以期为相关研究和应用提供参考。  相似文献   
12.
不同血清型口蹄疫病毒(FMDV)之间不能产生交叉免疫保护,但是血清学的交叉反应确实存在。本研究旨在建立一种筛选型间交互反应性抗体的方法,以期为解析FMDV血清型间保守的抗原结构奠定基础。本方法主要依据单个B细胞抗体技术,首先采用两种不同的荧光染料FluoProbes 647H和Pacific Blue分别标记O型与A型FMDV 146S灭活抗原,然后利用流式细胞分选技术,从免疫牛外周血单个核细胞(PBMCs)中分选出结合两种抗原的特异性B细胞,通过单个B细胞抗体基因测定,获得Ig G抗体重链与轻链可变区编码序列,并将可变区基因插入含有牛IgG抗体恒定区的pcDNA3.4载体中,构建IgG抗体的重链与轻链表达质粒。将重链与轻链表达质粒共转染中国仓鼠卵巢悬浮细胞(CHO-S)进行完整抗体表达。结果显示,通过该方法获得了5株FMDV特异性单克隆抗体,其中4株(H64、R82、I16、R29)经间接免疫荧光(IFA)检测都可特异性识别O和A型FMDV;ELISA结果显示,H64、R82、I16与O、A型抗原均具有较好的亲合力;Western-blot结果显示,I16可特异性结合O、A型FMDV结构蛋白VP2中的线性表位,说明在衣壳蛋白VP2上存在血清型间保守的抗原表位,通过本研究进一步加深了对FMDV抗原结构的认识。  相似文献   
13.
在RK-13细胞上培养的马动脉炎病毒(Equine viral arteritis,EAV)在4℃、室温和37℃条件下,用多种动物的红细胞进行血凝试验,病毒在不同温度下均可凝集小鼠和鸡的红细胞,但不能凝集牛、绵羊、山羊、马、猪、豚鼠、仓鼠、兔及鹅的红细胞.将病毒用吐温-80和乙醚处理后,血凝活力会显著增强,其HA效价比未经处理的病毒高4-8倍,且血凝像更加清晰.处理病毒的最适条件是在冰浴状态下用终浓度0.6-1.25 mL/L吐温-80振荡处理15-60 min,再加1/2体积的乙醚振荡作用5-15 min.  相似文献   
14.
健卫— 8小口径运动步枪属于小口径标准步枪 ,其枪弹为步枪长弹 ,在现场上时有出现。通过实验表明 ,该种步枪可致弹壳遗留较为清晰的痕迹主要有击针痕、拉壳钩痕、抛壳挺痕、弹底窝痕和枪机下表面痕 ,这些痕迹出现率也相对较高 ,为侦察检验鉴定提供了依据。  相似文献   
15.
The United States is experiencing growing impacts of climate change but currently receives a limited policy response from its national leadership. Within this policy void, many state governments are stepping up and taking action on adaptation planning. Yet we know little about why some states adopt State Adaptation Plans (SAPs), while others do not. This article investigates factors that predict the emergence of SAPs, both in terms of policy adoption and policy intensity (goal ambitiousness). Applying the diffusion of innovation theory, I consider the relative influence of internal state characteristics, regional pressures, and test for conditional effects between government ideologies and severity of the problem. The results show interesting differences between predictors that influence policy adoption and ambitiousness. States are more motivated to adopt a policy when faced with greater climate vulnerability, have more liberal citizenry, and where governments have crossed policy hurdles by previously passing mitigation plans. The intensity of policies and goal setting, moreover, is more likely to be driven by interest group politics and diffuse through policy learning or sharing information among neighboring states in Environmental Protection Agency regions. These findings support an emerging scholarship that uses more complex dependent variables in policy analysis. These variables have the potential to differentiate symbolic from substantive policies and capture finer information about predictors of importance.  相似文献   
16.
International research collaboration (IRC) is associated with both positive and negative effects on the performance of research in emerging economies. While some authors claim that North–South collaborations improve scientific quality and visibility for Southern countries, others claim that it may entail the reorientation of research to comply with Northern agendas. South–South collaborations are thought to increase the focus on local affairs, therefore leading to a relatively small number of scientific international publications appearing in “high quality” journals. Research on the impact of IRC beyond publications in international journals has been neglected despite the importance of other products in knowledge creation. This research uses a broad range of scientific outputs to empirically assess such assumptions and explore the outcomes of IRC in Colombia. Results from multivariate regressions and nonparametric analyses show that, contrary to common assumptions, Colombian research teams collaborating with partners from the global South report higher scientific production, while those collaborating with Northern countries seem to contribute to local knowledge the most.  相似文献   
17.
Members of parliament are key actors for the implementation of energy transitions, such as phasing out nuclear power. Before legislators can cast their maybe decisive vote in parliament, they need to run for office and actively strive for election. This paper assesses what political candidates oppose renewable energy transitions and questions whether the energy issue matters in national elections, and thus has consequences for the implementation of new sustainable energy sources. We analyze these questions by first describing the specific characteristics of political candidates. The paper then evaluates the relevance of the energy issue for electoral success in three national elections in Switzerland (2007, 2012, and 2015). Based on candidate data from the voting advice application smartvote.ch, we find that female candidates support ETs more than men do; that especially the French‐speaking part of the country is more in favor of a nuclear phase‐out, and that younger candidates are also more open toward restructuring the energy system than older candidates are. Our models further show that the energy issue does not matter in elections, independently from its salience in the respective election campaigns. Candidates are thus relatively free to choose their position on the issue and do not have to fear consequences at the ballot. However, candidates of center parties, in contrast to the pole parties, are sensitive to the energy issue and reflect public mood in their positions.  相似文献   
18.
The U.S. electric power sector has experienced a substantial shift of the generation mix since the turn of the century, moving from heavy reliance on coal‐powered generation to one drawing more from natural gas and, more recently, renewables. This transition has been forged by a mix of macroeconomic factors (recession and recovery); technological breakthroughs (horizontal drilling coupled with hydraulic fracturing; improvements in natural gas plant efficiency); clean energy policies at federal, state, and local levels of government; and private sector demands for carbon‐free energy sources. These factors have combined to reduce carbon emissions from electric power generation substantially this century. In this article we examine the extent of this transition, its causes, as well as the distinct American institutional factors steering it, including energy and environmental federalism, electoral politics, and the political economy of clean energy policy enactment and resistance.  相似文献   
19.
As the emergence of nongovernmental conservation efforts generates conflict among various stakeholders, the causal story that each party articulates regarding conservation and the causes of land degradation reflects their unique interests. This study uses existing literature to evaluate causal stories surrounding a contemporary conservation effort: Montana's American Prairie Reserve. Through qualitative review of web‐based documents and newspaper articles, it generates a preliminary account of key stakeholders' causal stories. The case study suggests that parties who might be disadvantaged by ascribing responsibility for environmental harms in an adversarial fashion may instead elect to articulate causal stories that are more neutral than existing approaches might forecast. The study concludes by suggesting that further development of causal story literature may enable it to better address contemporary conservation efforts.  相似文献   
20.
《Labor History》2012,53(4):423-458
Well known is that the National Labor Relations Act (NLRA, 1935) in the United States places a largely per se ban on nonunion employee representation (ER) groups which deal with employers over a term or condition of employment. Much less well known is that America’s other labor law, the Railway Labor Act (RLA, 1926), takes a different approach and permits employers to operate such councils and committees as long as they do not perform a collective bargaining function or interfere with workers’ free choice of a bargaining agent. Thus, under the RLA Delta Air Lines is able to operate what is today the closest living approximation to a 1920s-style ER plan while hundreds of other companies (e.g. Polaroid) under the jurisdiction of the NLRA have been forced over the years to disband similar groups on grounds they are a proscribed company union. No study to date has explored the history behind the RLA and NLRA’s divergent treatment of nonunion ER groups so this article takes a first look. The main part of the story covers the 1920–1935 period and examines the events, people, and experiences associated with company unions and ER in, respectively, the rail and manufacturing industries and why the legislative outcome in the former was a permissive stance on nonunion committees but prohibitive in the latter. The last part of the paper fast-forwards the RLA-NLRA story from the 1930s to contemporary law and practice in order to demonstrate how “history matters” when it comes to what employers can and cannot do with nonunion representation groups, such as works councils, participation and involvement committees, and dispute resolution forums.  相似文献   
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