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201.
人类最大可持续海洋足迹的模拟 总被引:1,自引:0,他引:1
在William Rees & Mathis Wackernagel最初提出的生态足迹模型理论所划分的六类基本生态生产性土地面积中,海洋以其能为人类提供鱼类等海产品而被单独列为水域一项。海洋生物资源是一种典型的可再生资源,人类只有采取合理的开发策略方可保证海洋生物资源最大的可持续生产量。借用生态足迹、生物承载力概念的内涵,提出海洋足迹、海洋承载力两个新概念;运用非线性科学理论在海洋足迹与海洋承载力呈二次非线性关系的假设下,建立海洋承载力二次非线性开发的动力模式,并运用稳定性分析理论对其求解、分析。结果表明:(1)海洋承载力与其增长率呈正相关关系,与海洋足迹增长率呈负相关关系;(2)为保证海洋生物资源的可持续利用,人类必须控制最大海洋足迹增长率为r/xm(r为海洋承载力增长率,xm为最大海洋承载力),方可获得可持续的最大海洋足迹为rxm/4,此时海洋承载力可以维持在稳定的平衡态(为其最大承载力的一半)。 相似文献
202.
康宁木霉CP88329纤维素酶产生条件的研究 总被引:25,自引:2,他引:25
从生霉棉布上分离出的康宁木霉CP88105经诱变处理,获得一株高产纤维素酶的突变株CP88329。在固体培养基上,28℃培养72小时,所产纤维素酶固体曲,以羧甲基纤维素钠为底物酶活力为4880u/g;以脱脂棉为底物酶活力为480u/g。产酶活力水平均为出发菌的3倍。酶在脱脂棉上作用最适条件为pH4.5-5.0,45-50℃;45℃保温4h,pH稳定范围为3.5-6.5;60℃保温1h,酶活力剩余20%。酶可用于苎麻布抛光处理和牛仔服“石磨”处理。 相似文献
203.
204.
Jiamao Fan Qing Zhu Zhenhua Wu Jiao Ding Shuai Qin Hui Liu Pengfei Miao 《Journal of cellular physiology》2020,235(2):1165-1174
Recent evidence has verified the cardioprotective actions of irisin in different diseases models. However, the beneficial action of irisin on hypoxia-reoxygenation (HR) injury under high glucose stress has not been described. Herein our research investigated the influence of irisin on HR-triggered cardiomyocyte death under high glucose stress. HR model was established in vitro under high glucose treatment. The results illuminated that HR injury augmented apoptotic ratio of cardiomyocyte under high glucose stress; this effect could be abolished by irisin via modulating mitochondrial function. Irisin treatment attenuated cellular redox stress, improved cellular ATP biogenetics, sustained mitochondria potential, and impaired mitochondrion-related cell death. At the molecular levels, irisin treatment activated the 5′-adenosine monophosphate-activated protein kinase (AMPK) pathway and the latter protected cardiomyocyte and mitochondria against HR injury under high glucose stress. Altogether, our results indicated a novel role of irisin in HR-treated cardiomyocyte under high glucose stress. Irisin-activated AMPK pathway and the latter sustained cardiomyocyte viability and mitochondrial function. 相似文献
205.
政策工具被认为是政府为解决某个公共问题采取的具体手段或措施,一项政策可以视作目标和多种政策工具的组合。在生态治理过程中,不同政策工具对农户行为的刺激程度不同,进而导致不同的政策效果。分离不同政策工具的影响,可为工具选择和政策优化提供科学参考。以盐池县为例,利用基于该县1983-2017年内出台的316份生态政策文本构建的政策工具数据集和VAR模型中的脉冲响应和方差分解方法定量研究了强制型、混合型和自愿型三大类政策工具及十种子工具对农户耕作、放牧、造林3种行为的影响。结果表明:(1)政策工具对农户行为的影响具有时效性,一般在政策出台后2-3年内影响最大,随后逐渐减小并消失,影响持续时间为7-10年。(2)总体来看,政策工具对农户行为的冲击力度较小,冲击范围在0-0.30之间,说明农户行为还受到其他诸多因素的影响。(3)10年累计影响从大到小依次为强制型、混合型、自愿型,其中直接提供和规制两种子工具的影响最大。放牧行为受到政策工具的刺激最大,耕作行为次之,造林行为最小。(4)直接提供工具对耕作行为具有最大正向影响,最大冲击为0.30;规制工具在短期内抑制牲畜数量增长,而直接提供和补贴工具促进牲畜数量增长,且由于冲击曲线存在正负波动,说明政府与农户在牲畜养殖上存在长期博弈;只有规制工具对造林行为具有积极影响,说明造林更多是在政府的主导下进行。建议充分利用政策工具的短期效应,凸显政府角色,及时做好政策效果评估工作,调整工具组合,助力生态目标的实现。 相似文献
206.
Chang Cao Bo Wang Junnan Tang Jimin Zhao Jiacheng Guo Qianqian Guo Xiaoting Yue Zenglei Zhang Gangqiong Liu Hui Zhang Yunzhe Wang Jinying Zhang 《Journal of cellular and molecular medicine》2021,25(4):2176-2189
Circulating exosomes delivering microRNAs are involved in the occurrence and development of cardiovascular diseases. How are the circulating exosomes involved in the repair of endothelial injury in acute myocardial infarction (AMI) convalescence (3-7 days) was still not clear. In this study, circulating exosomes from AMI patients (AMI-Exo) and healthy controls (Normal-Exo) were extracted. In vitro and in vivo, our study showed that circulating exosomes protected endothelial cells (HUVECs) from oxidative stress damage; meanwhile, Normal-Exo showed better protective effects. Through the application of related inhibitors, we found that circulating exosomes shuttled between HUVECs via dynamin. Microarry analysis and qRT-PCR of circulating exosomes showed higher expression of miR-193a-5p in Normal-Exo. Our study showed that miR-193a-5p was the key factor on protecting endothelial cells in vitro and in vivo. Bioinformatics analyses found that activin A receptor type I (ACVR1) was the potential downstream target of miR-193a-5p, which was confirmed by ACVR1 expression and dual-luciferase report. Inhibitor of ACVR1 showed similar protective effects as miR-193a-5p. While overexpression of ACVR1 could attenuate protective effects of miR-193a-5p. To sum up, these findings suggest that circulating exosomes could shuttle between cells through dynamin and deliver miR-193a-5p to protect endothelial cells from oxidative stress damage via ACVR1. 相似文献
207.
建立冰乙酸性大鼠胃溃疡模型,采用ABC法进行免疫组织化学染色,观察并探讨胃溃疡对胃壁中HAP1(huntingtin as-soc iated protein 1,HAP1)表达的影响。结果溃疡组大鼠胃壁中HAP1阳性细胞数目及光密度与正常进食的大鼠相比显著增多。 相似文献
208.
The SNPlex genotyping system: a flexible and scalable platform for SNP genotyping. 总被引:10,自引:0,他引:10
Andreas R Tobler Sabine Short Mark R Andersen Teodoro M Paner Jason C Briggs Stephen M Lambert Priscilla P Wu Yiwen Wang Alexander Y Spoonde Ryan T Koehler Nicolas Peyret Caifu Chen Adam J Broomer Dana A Ridzon Hui Zhou Bradley S Hoo Kathleen C Hayashibara Lilley N Leong Congcong N Ma Barnet B Rosenblum Joseph P Day Janet S Ziegle Francisco M De La Vega Michael D Rhodes Kevin M Hennessy H Michael Wenz 《Journal of biomolecular techniques》2005,16(4):398-406
We developed the SNPlex Genotyping System to address the need for accurate genotyping data, high sample throughput, study design flexibility, and cost efficiency. The system uses oligonucleotide ligation/polymerase chain reaction and capillary electrophoresis to analyze bi-allelic single nucleotide polymorphism genotypes. It is well suited for single nucleotide polymorphism genotyping efforts in which throughput and cost efficiency are essential. The SNPlex Genotyping System offers a high degree of flexibility and scalability, allowing the selection of custom-defined sets of SNPs for medium- to high-throughput genotyping projects. It is therefore suitable for a broad range of study designs. In this article we describe the principle and applications of the SNPlex Genotyping System, as well as a set of single nucleotide polymorphism selection tools and validated assay resources that accelerate the assay design process. We developed the control pool, an oligonucleotide ligation probe set for training and quality-control purposes, which interrogates 48 SNPs simultaneously. We present performance data from this control pool obtained by testing genomic DNA samples from 44 individuals. in addition, we present data from a study that analyzed 521 SNPs in 92 individuals. Combined, both studies show the SNPlex Genotyping system to have a 99.32% overall call rate, 99.95% precision, and 99.84% concordance with genotypes analyzed by TaqMan probe-based assays. The SNPlex Genotyping System is an efficient and reliable tool for a broad range of genotyping applications, supported by applications for study design, data analysis, and data management. 相似文献
209.
目的探讨环氧合酶2(COX-2)在宫颈癌组织中的表达与月经周期的关系及其临床意义。方法选取47例未绝经宫颈癌手术病人,病史结合子宫内膜HE染色观察判断患者所处月经周期时段,采用免疫组织化学SP法检测宫颈癌组织中COX-2及增殖细胞核抗原(PCNA)的表达,计算机图像分析COX-2免疫染色密度值及PCNA标记指数(LI)。结果宫颈癌组织中COX-2表达阳性者增生期表达强于分泌期(P<0.05),但阳性率无显著性差异(P>0.05),COX-2阳性癌组织中PCNALI高于阴性者,差异有显著性(P<0.01)。有淋巴结转移者COX-2的表达高于无转移者(P<0.05),宫颈癌组织中COX-2的表达与FIGO临床分期、组织分化程度无显著相关性(P>0.05)。结论未绝经宫颈癌患者肿瘤组织中COX-2的表达在增生期较分泌期明显增加,并参与调节肿瘤的生长、转移。 相似文献
210.
MeTaDoR: a comprehensive resource for membrane targeting domains and their host proteins 总被引:1,自引:0,他引:1
MOTIVATION: Protein-lipid interactions play a central role in cellular signaling and membrane trafficking and at the core of these interactions are domains specialized in lipid binding and membrane targeting. Considering the importance of these domains, we have created MeTaDoR, a comprehensive resource dedicated to membrane targeting domains (MTDs). RESULT: MeTaDoR begins with a brief introduction about all the important MTDs including their subcellular localization and structural features. Sequences of all known MTDs are then provided in two formats: standard Prosite format and a parsed tab-delimited format that provides a manually curated classification into binding or non-binding. Structures of all MTDs and host proteins known so far are provided with links to PDB and Pfam databases. Membrane-binding orientation of these proteins, whether experimentally determined or proposed, is also provided with links to the appropriate literature. To facilitate molecular dynamics studies of these proteins, the force-field parameters for many non-standard lipids that commonly interact with these proteins are also provided. Finally, an online server for predicting membrane-binding proteins and a search function with various search fields are included. The resource is publicly available and will be updated on a regular basis. 相似文献