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991.
摘要 目的:探究寿胎丸提高子宫树突状细胞的表达改善超促排卵(controlled ovary hyperstimulation,COH)大鼠子宫内膜容受性。方法:将大鼠随机分为对照组、模型组、寿胎丸(低、中、高剂量)组,用促性激素释放激素激动剂(gonadotropin releasing hormone agonist,GnRH-a)、尿促性腺激素(human menopausal gonadotropin,HMG)和人绒毛膜促性腺激素(human chorionic gonado-tropin,HCG)构建COH大鼠模型,寿胎丸低、中、高剂量组采用2.5、5和10 g/ kg/d寿胎丸灌胃。流式检测子宫内膜树突状细胞(Uterine dendritic call,uDC)表面特异性标记蛋白OX-62。Western blot检测CD34和血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白表达。结果:与对照组比较,模型组OX-62阳性表达率降低,CD34和VEGF表达明显降低(P<0.05)。与模型组比较,寿胎丸低、中、高剂量组OX-62阳性表达率上升,CD34和VEGF表达明显升高,呈剂量依赖性(P<0.05)。结论:寿胎丸提高子宫树突状细胞的表达改善超促排卵大鼠子宫内膜容受性。  相似文献   
992.
多细胞有机体的细胞类型多且复杂,细胞间普遍存在异质性。目前,单细胞转录组测序(single-cell RNA sequencing,scRNA-seq)技术是一项新兴的研究单个细胞转录水平的技术,其从数千个平行的细胞中生成转录谱,揭示个体细胞基因组的差异性表达,反映细胞间的异质性,从而鉴定出不同细胞类型,形成组织或器官的细胞图谱,在生物和临床医学等领域发挥重要作用。该文在对scRNA-seq测序平台进行阐述和比较的基础上,着重介绍其在神经系统和免疫系统细胞类型探索中的应用,并且总结scRNA-seq与空间转录组技术相结合的研究成果。  相似文献   
993.
Understanding the variations of muscle and plasma metabolites in response to high environmental temperature can provide important information on the molecular mechanisms related to body energy homeostasis in heat-stressed broiler chickens. In this study, we investigated the effect of chronic heat stress conditions on the breast muscle (Pectoralis major) and plasma metabolomics profile of broiler chickens by means of an innovative, high-throughput analytical approach such as the proton nuclear magnetic resonance (1H NMR) spectrometry. A total of 300 Ross 308 male chicks were split into two experimental groups and raised in either thermoneutral conditions for the entire rearing cycle (0–41 days) (TNT group; six replicates of 25 birds/each) or exposed to chronic heat stress conditions (30 °C for 24 h/day) from 35 to 41 days (CHS group; six replicates of 25 birds/each). At processing (41 days), plasma and breast muscle samples were obtained from 12 birds/experimental group and then subjected to 1H NMR analysis. The reduction of BW and feed intake as well as the increase in rectal temperature and heterophil: lymphocyte ratio confirmed that our experimental model was able to stimulate a thermal stress response without significantly affecting mortality. The 1H NMR analysis revealed that a total of 26 and 19 molecules, mostly related to energy and protein metabolism as well as antioxidant response, showed significantly different concentrations respectively in the breast muscle and plasma in response to the thermal challenge. In conclusion, the results obtained in this study indicated that chronic heat stress significantly modulates the breast muscle and plasma metabolome in fast-growing broiler chickens, allowing to delineate potential metabolic changes that can have important implications in terms of body energy homeostasis, growth performance and product quality.  相似文献   
994.
海洋放线菌生活的环境如养分、光照、氧气浓度、压力、盐度和温度等与陆地环境存在极大差异,因此海洋放线菌形成了独特的生物化学代谢和生理能力。近年来,海洋放线菌成为生物资源开发和研究的热点。海洋放线菌分布广泛,种类多样。海洋放线菌活性代谢产物具有极强的医药应用潜力,其代谢产物的功能研究及重要代谢产物的开发成为海洋放线菌研究的重要方向。此外,海洋放线菌在环境保护以及生产应用等方面展现出的潜能,引起研究人员极大的兴趣。本文结合近年来海洋放线菌的分离种类与生境、海洋放线菌的研究策略与手段以及代谢产物功能多样性进行了归纳总结,以期对海洋放线菌的认识更全面、系统。  相似文献   
995.
Non-transfusion autologous platelet concentrate (PC), also known as platelet-rich plasma (PRP), has become a widely used blood-based product in the field of sports medicine, rehabilitation medicine, and clinical medicine. Currently, autologous PC or PRP operation procedures (personnel qualification, equipment, methods, environment and tracking, protocols, preparations, techniques and product quality control) lack unified specifications and standards, which lead to inconsistencies in the quality of PC or PRP products made by medical institutions, affecting treatment efficiency. In blood collection and supply organizations, the collection of blood components has a series of standard operating procedures (SOP) and quality assurance which can be referenced by medical institutions to standardize the preparation and usage of patient autologous PC or PRP products. According to Technical Standards for Preparation of Platelet Concentrate for Blood Stations, we compiled this guideline for medical staff to prepare high quality and reliable PC or PRP products in order to promote the standardization of PC or PRP in clinical application.  相似文献   
996.
为了解肉鸡屠宰加工过程中胴体的微生物污染情况,综述了肉鸡屠宰各环节中微生物的污染来源及菌群变化,同时探讨了相应的减菌措施,对在线控制各环节胴体表面细菌交叉污染和提高鸡肉产品的安全性、食用性和经济性有着重要的意义。  相似文献   
997.
正交试验法优化桑叶多糖提取工艺   总被引:2,自引:0,他引:2  
以脱除黄酮的桑叶为原料,采用热水浸提法提取桑叶多糖,研究了提取温度、提取时间、料液比、水溶液pH和提取次数对桑叶多糖得率的影响,通过正交实验优化了提取工艺条件。结果表明,在提取次数为2次条件下,桑叶多糖最佳提取工艺条件为提取温度100℃、提取时间4 h、提取液pH7、料液比(原料:提取液,g/mL)1:30,多糖得率为2.74%。该工艺稳定,桑叶多糖得率高,易于工业化生产。  相似文献   
998.
通路克隆入门载体pEN-L4~*-PrbcS-~*T-gfp-L3~*的构建及其应用   总被引:1,自引:0,他引:1  
为了利用通路克隆(Gateway)技术构建一个含有两个目的基因表达盒的植物表达载体,并把目的基因编码的蛋白质定位到转基因植物的叶绿体中,通过定点突变技术,在含有attL4和attL3重组位点的Gateway入门载体pEN-L4-2-L3中产生HindⅢ和XhoⅠ的酶切位点,然后在这两个酶切位点之间插入一个含有1,5-二磷酸核酮糖羧化酶小亚基的光诱导型启动子(PrbcS)及其叶绿体基质定位序列(*T)和绿色荧光蛋白(GFP)报告基因(gfp)的DNA片段,获得pEN-L4*-PrbcS-*T-gfp-L3*入门载体.用该载体和另一个含有attL1和attL2重组位点的入门载体(pENTR*-PrbcS-*T-gus)与Gateway的目的载体pK7 m34GW2-8 m21GW3进行LR重组反应可以构建一个能串联gfp和gus两个报告基因表达盒的植物表达载体pKm-35S-PrbcS-*T-gfp-PROLD-PrbcS-*T-gus,所构建的植物表达载体转化烟草后,gfp和gus基因能插入到转基因烟草的基因组中并正常表达,所表达的GFP蛋白可正确定位到转基因植物的叶绿体中,而GUS蛋白也可以在叶片中表达.利用此表达载体通过一次转化事件不仅可以完成两个目的基因的转化操作,而且还可以利用叶绿体基质定位序列(*T)把PrbcS控制表达的目的蛋白直接定位到转基因植物的叶绿体中.因此pEN-L4*-PrbcS-*T-gfp-L3*入门载体的应用进一步扩大了Gateway技术及植物表达载体的应用范围,为叶绿体基因工程操作提供了一个更方便的技术平台.  相似文献   
999.
In 1989, Wynn and McGrew published an explicit comparison between Oldowan technology and what was then known of chimpanzee technology. They compared the range and variety of tools, adaptive role of tools, carrying distances, spatial cognition, manufacturing procedures, and modes of learning. They concluded that everything archeologists had reconstructed about the behavior of Oldowan hominins could be accommodated within the ape adaptive grade; that is, a paraphyletic group united by overall similarities in anatomy and, in this case, behavior. The only Oldowan activities that were almost unknown for modern apes were the long-distance transport of objects and direct competition with carnivores, which was implied by meat acquisition activities. "In its general features Oldowan culture was ape, not human. Nowhere in this picture need we posit elements such as language, extensive sharing, division of labor, or pair-bonded families, all of which are part of the baggage carried by the term human."  相似文献   
1000.
A metabolic network can be described by a set of elementary modes or pathways representing discrete metabolic states that support cell function. We have recently shown that in the most likely metabolic state the usage probability of individual elementary modes is distributed according to the Boltzmann distribution law while complying with the principle of maximum entropy production. To demonstrate that a metabolic network evolves towards such state we have carried out adaptive evolution experiments with Thermoanaerobacterium saccharolyticum operating with a reduced metabolic functionality based on a reduced set of elementary modes. In such reduced metabolic network metabolic fluxes can be conveniently computed from the measured metabolite secretion pattern. Over a time span of 300 generations the specific growth rate of the strain continuously increased together with a continuous increase in the rate of entropy production. We show that the rate of entropy production asymptotically approaches the maximum entropy production rate predicted from the state when the usage probability of individual elementary modes is distributed according to the Boltzmann distribution. Therefore, the outcome of evolution of a complex biological system can be predicted in highly quantitative terms using basic statistical mechanical principles.  相似文献   
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