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排序方式: 共有1309条查询结果,搜索用时 15 毫秒
1.
猪瘟病毒反义cDNA片段的化学合成及克隆   总被引:1,自引:0,他引:1  
涂长春  江南 《病毒学报》1992,8(4):383-385
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Vascular endothelial growth factor (VEGF) is a well‐known angiogenic factor, however its ability in promoting therapeutic angiogenesis following myocardial infarction (MI) is limited. Here, we aimed to investigate whether dual treatment with insulin‐like growth factor binding protein‐4 (IGFBP‐4), an agent that protects against early oxidative damage, can be effective in enhancing the therapeutic effect of VEGF following MI. Combined treatment with IGFBP‐4 enhanced VEGF‐induced angiogenesis and prevented cell damage via enhancing the expression of a key angiogenic factor angiopoietin‐1. Dual treatment with the two agents synergistically decreased cardiac fibrosis markers collagen‐I and collagen‐III following MI. Importantly, while the protective action of IGFBP‐4 occurs at an early stage of ischemic injury, the action of VEGF occurs at a later stage, at the onset angiogenesis. Our findings demonstrate that VEGF treatment alone is often not enough to protect against oxidative stress and promote post‐ischemic angiogenesis, whereas the combined treatment with IGFBP4 and VEGF can utilize the dual roles of these agents to effectively protect against ischemic and oxidative injury, and promote angiogenesis. These findings provide important insights into the roles of these agents in the clinical setting, and suggest new strategies in the treatment of ischemic heart disease.  相似文献   
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The balance between bone formation and bone resorption is closely related to bone homeostasis. Osteoclasts, originating from the monocyte/macrophage lineage, are the only cell type possessing bone resorption ability. Osteoclast overactivity is thought to be the major reason underlying osteoclast‐related osteolytic problems, such as Paget's disease, aseptic loosening of prostheses and inflammatory osteolysis; therefore, disruption of osteoclastogenesis is considered a crucial treatment option for these issues. WKYMVm, a synthetic peptide, which is a potent FPR2 agonist, exerts an immunoregulatory effect. This peptide inhibits the production of inflammatory cytokines, such as (IL)‐1β and TNF‐α, thus regulating inflammation. However, there are only few reports on the role of WKYMVm and FPR2 in osteoclast cytology. In the current study, we found that WKYMVm negatively regulates RANKL‐ and lipopolysaccharide (LPS)‐induced osteoclast differentiation and maturation in vitro and alleviates LPS‐induced osteolysis in animal models. WKYMVm down‐regulated the expression of osteoclast marker genes and resorption activity. Furthermore, WKYMVm inhibited osteoclastogenesis directly through reducing the phosphorylation of STAT3 and NF‐kB and indirectly through the CD9/gp130/STAT3 pathway. In conclusion, our findings demonstrated the potential medicinal value of WKYMVm for the treatment of inflammatory osteolysis.  相似文献   
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There are many different types of cardiovascular diseases, which impose a huge economic burden due to their extremely high mortality rates, so it is necessary to explore the underlying mechanisms to achieve better supportive and curative care outcomes. Sphingosine 1‐phosphate (S1P) is a bioactive lipid mediator with paracrine and autocrine activities that acts through its cell surface S1P receptors (S1PRs) and intracellular signals. In the circulatory system, S1P is indispensable for both normal and disease conditions; however, there are very different views on its diverse roles, and its specific relevance to cardiovascular pathogenesis remains elusive. Here, we review the synthesis, release and functions of S1P, specifically detail the roles of S1P and S1PRs in some common cardiovascular diseases, and then address several controversial points, finally, we focus on the development of S1P‐based therapeutic approaches in cardiovascular diseases, such as the selective S1PR1 modulator amiselimod (MT‐1303) and the non‐selective S1PR1 and S1PR3 agonist fingolimod, which may provide valuable insights into potential therapeutic strategies for cardiovascular diseases.  相似文献   
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Additives are widely adopted for efficient, stable, and hysteresis‐free perovskite solar cells and play an important role in various breakthroughs of perovskite solar cells (PSCs). Herein the various additives adopted for PSCs are reviewed and their functioning mechanism and influence on device performance is described. The main roles of additives, modulating morphology of perovskite films, stabilizing phase of formamidinium (FA) and cesium (Cs)‐based perovskites, adjusting energy level alignment in PSCs, suppressing nonradiative recombination in perovskites, eliminating hysteresis, enhancing operational stability of PSCs, are summarized.  相似文献   
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Alginate is an important polysaccharide that is commonly used as a gelling agent in foods, cosmetics and healthcare products. Currently, all alginate used commercially is extracted from brown seaweed. However, with environmental changes such as increasing ocean temperature and the increasing number of biotechnological uses of alginates with specific properties, there is an emerging need for more reliable and customizable sources of alginate. An alternative to seaweed for alginate production is Pseudomonas aeruginosa, a common Gram-negative bacterium that can form alginate-containing biofilms. However, P. aeruginosa is an opportunistic pathogen that can cause life-threatening infections in immunocompromised patients. Therefore, we sought to engineer a non-pathogenic P. aeruginosa strain that is safe for commercial production of alginate. Using a homologous recombination strategy, we sequentially deleted five key pathogenicity genes from the P. aeruginosa chromosome, resulting in the marker-free strain PGN5. Intraperitoneal injection of mice with PGN5 resulted in 0% mortality, while injection with wild-type P. aeruginosa resulted in 95% mortality, providing evidence that the systemic virulence of PGN5 is highly attenuated. Importantly, PGN5 produces large amounts of alginate in response to overexpression of MucE, an activator of alginate biosynthesis. The alginate produced by PGN5 is structurally identical to alginate produced by wild-type P. aeruginosa, indicating that the alginate biosynthetic pathway remains functional in this modified strain. The genetic versatility of P. aeruginosa will allow us to further engineer PGN5 to produce alginates with specific chemical compositions and physical properties to meet different industrial and biomedical needs.  相似文献   
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Host microbiomes play a critical role in host fitness and health. Whilst the current 'holobiont' concept framework has greatly expanded eco-evolutionary and functional understanding of host-microbiome interactions, the important role of biotic interactions and microbial loop (compositional linkage between soil, plant and animal) in shaping host-microbiome are poorly understood. We proposed an 'eco-holobiont' concept to fill the knowledge gap.  相似文献   
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目的探讨粪菌移植(fecal microbiota transplantation,FMT)对非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)大鼠肠黏膜屏障的保护作用。方法健康雄性SD大鼠30只,随机分为3组:正常对照组(control group,C组)10只,予正常饮食;高脂模型组(model group,M组)10只、粪菌移植治疗组(treatment group,T组)10只,M组和T组均予高脂饮食。T组予粪菌液灌胃2 mL/次,隔日1次,粪菌液灌胃的前一天晚上及当天早上均予奥美拉唑镁肠溶片灌胃;C组及M组同时予奥美拉唑及生理盐水灌胃。喂养12周后实验结束,测定血中TG、ALT、AST水平;苏丹黑B染色观察肝脏病理学变化;取回肠末端肠组织行HE染色及扫描电镜观察肠黏膜结构变化。结果与M组大鼠相比,T组血清TG、ALT、AST水平降低,差异有统计学意义(均P0.05)。T组大鼠肝脏苏丹黑B染色可见肝细胞内脂肪沉积明显减少,脂肪变性程度较M组减轻。T组大鼠肠组织HE染色肠绒毛轻度水肿,排列较整齐、紧密。扫描电镜中可见T组大鼠肠绒毛形态较饱满,排列比较紧密,微绒毛之间的间隙变小。结论粪菌移植能改善肝功能,减轻肝脏脂肪变,降低肠道通透性,改善肠黏膜屏障功能。  相似文献   
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The park management (PM) that evolved from the park-renewal project based on Installation-Management Permission (IMP) in Tennoji Park, a major urban park in Osaka City, Japan is evaluated herein. The PM of Tennoji Park is composed of 'hard' and 'soft' tasks. The process and characteristics of the hard tasks, i.e., the park-renewal project including the construction of a significant landmark, the lawn plaza (named 'TEN-SHIBA') and convenience facilities with various service functions are analyzed. The details and outcomes of the soft tasks including cleaning, security, and lawn/planting management plus events held on the TEN-SHIBA plaza are also clarified. The PM results and financial effects of the introduction of IMP in TEN-SHIBA are evaluated based on both the park users' characteristics obtained by a questionnaire, an observation survey of the park users, and a data analysis of the track record. Based on a comparison with Sumiyoshi Park, an urban park similar to TEN-SHIBA but without the introduction of IMP, it was found that young females were the predominant users of TEN-SHIBA, and the average staying time on the lawn plaza was 2 min. longer than that in Sumiyoshi park. Together these results suggest the effectiveness of IMP for PM based on the TEN-SHIBA experience. It also appears that placing a plaza in the center of a park and providing facilities and various events by private business operators can generate profits; this might be effective for future PM hard tasks, while various and continuous soft task efforts remain essential.

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