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1.
每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.  相似文献   

2.
Environmental toxicants are ubiquitous,and many are known to cause harmful health effects.However,much of what we know or think we know concerning the targets and long-term effects of exposure to environmental stressors is sadly lacking.Toxicant exposure may have health effects that are currently mischaracterized or at least mechanistically incompletely understood.While much of the recent excitement about stem cells(SCs)focuses on their potential as therapeutic agents,they also offer a valuable resource to give us insight into the mechanisms and risks of toxicant effects.Not only as a response to the increasing ethical pressure to reduce animal testing,SC studies allow us valuable insight into the true effects of human exposure to environmental stressors under controlled conditions.We present a review of the history of publications on the effects of environmental stressors on SCs,followed by a consolidation of the literature over the past five years on a subset of key environmental stressors of importance to human health and their effects on both embryonic and tissue SCs.The review will make constructive suggestions as to areas of toxicant research where further studies are needed,as well as making indications of the potential utility for advancing knowledge and directing research on environmental toxicology.  相似文献   

3.
走进内蒙     
孙丹辉 《化石》2016,(1):61-65
2015年8月1日,我们每一个人收拾好行囊,整装待发,在邓涛老师带领下踏上了去往内蒙古的征程,拉开了探索灰色生命之旅的序幕. 队伍由两辆车、8人组成,我们早晨7点从中国科学院古脊椎动物与古人类研究所出发,披着清晨的阳光,摆脱城市的拥挤,缓缓地“逃离”了北京城.直到抵达张北之后我们的车子才能像矫健的马儿一样驰骋在广袤的公路上,沿途没有了城市的喧闹,没有了交通的堵塞,伴随我们的只有那一眼望去蓝蓝的天空、随风摆动的小草,以及那迷人的风景,偶尔打开车窗,一股凉爽的清风扑面而来,沁人心脾.经过一路的颠簸,我们在傍晚时刻到达锡林浩特,当地文物保护站的同志为我们安顿好了一切.  相似文献   

4.
通过现代生物科技专题及相关高考试题的介绍与分析,以开拓学生视野,增强科技意识,激发学生探索生命奥妙和热爱生物科学的情感,为进一步学习现代生物学奠定基础.同时,借助现代生物科技专题作试题背景,具有能力的开放性和情境的新颖性,也有利于考查和培养学生独立获取新知识、收集和处理信息的能力.所选试题涉及现代生物科技前沿的领域有:基因工程、细胞工程、蛋白质工程、癌症和克隆技术等,均体现出对现代生物技术发展的关注.  相似文献   

5.
The development of multilayer network techniques is a boon for researchers who wish to understand how different interaction layers might influence each other,and how these in turn might influence group dynamics.Here,we investigate how integration between male and female grooming and aggression interaction networks influences male power trajectories in vervet monkeys Chlorocebus pygerythrus.Our previous analyses of this phenomenon used a monolayer approach,and our aim here is to extend these analyses using a dynamic multilayer approach.To do so,we constructed a temporal series of male and female interaction layers.We then used a multivariate multilevel autoregression model to compare cross-lagged associations between a male's centrality in the female grooming layer and changes in male Elo ratings.Our results confirmed our original findings:changes in male centrality within the female grooming network were weakly but positively tied to changes in their Elo ratings.However,the multilayer network approach offered additional insights into this social process,identifying how changes in a male's centrality cascade through the other network layers.This dynamic view indicates that the changes in Elo ratings are likely to be short-lived,but that male centrality within the female network had a much stronger impact throughout the multilayer network as a whole,especially on reducing intermale aggression(i.e.,aggression directed by males toward other males).We suggest that multilayer social network approaches can take advantage of increased amounts of social data that are more commonly collected these days,using a variety of methods.Such data are inherently multilevel and multilayered,and thus offer the ability to quantify more precisely the dynamics of animal social behaviors.  相似文献   

6.
Insect-vectored plant viruses can induce changes in plant phenotypes,thus influencing plant-vector interactions in a way that may promote their dispersal according to their mode of transmission (i.e.,circulative vs.noncirculative).This indirect vector manipulation requires host-virus-vector coevolution and would thus be effective solely in very specific plant-virus-vector species associations.Some studies suggest this manipulation may depend on multiple factors relative to various intrinsic characteristics of vectors such as transmission efficiency.In anintegrative study,we tested the effects of infection of the Brassicaceae Camelina sativa with the noncirculative Cauliflower mosaic virus (CaMV)or the circulative Turnip yellows virus (TuYV)on the host-plant colonization of two aphid species differing in their virus transmission efficiency:the polyphagous Myzus persicae,efficient vector of both viruses,and the Brassicaceae specialist Brevicoryne brassicae,poor vector of TuYV and efficient vector of CaMV.Results confirmed the important role of virus mode of transmission as plant-mediated effects of CaMV on the two aphid species induced negative alterations of feeding behavior (i.e.,decreased phloem sap ingestion)and performance that were both conducive for virus fitness by promoting dispersion after a rapid acquisition.In addition,virus transmission efficiency may also play a role in vector manipulation by viruses as only the responses of the efficient vector to plant-mediated effects of TuYV,that is,enhanced feeding behavior and performances,were favorable to their acquisition and further dispersal.Altogether,this work demonstrated that vector transmission efficiency also has to be considered when studying the mechanisms underlying vector manipulation by viruses.Our results also re- inforce the idea that vector manipulation requires coevolution between plant,virus and vector.  相似文献   

7.
BACKGROUND Digestive tract resections are usually followed by an anastomosis.Anastomotic leakage,normally due to failed healing,is the most feared complication in digestive surgery because it is associated with high morbidity and mortality.Despite technical and technological advances and focused research,its rates have remained almost unchanged the last decades.In the last two decades,stem cells(SCs)have been shown to enhance healing in animal and human studies;hence,SCs have emerged since 2008 as an alternative to improve anastomoses outcomes.AIM To summarise the published knowledge of SC utilisation as a preventative tool for hollow digestive viscera anastomotic or suture leaks.METHODS PubMed,Science Direct,Scopus and Cochrane searches were performed using the key words“anastomosis”,“colorectal/colonic anastomoses”,“anastomotic leak”,“stem cells”,“progenitor cells”,“cellular therapy”and“cell therapy”in order to identify relevant articles published in English and Spanish during the years of 2000 to 2021.Studies employing SCs,performing digestive anastomoses in hollow viscera or digestive perforation sutures and monitoring healing were finally included.Reference lists from the selected articles were reviewed to identify additional pertinent articles.METHODS Given the great variability in the study designs,anastomotic models,interventions(SCs,doses and vehicles)and outcome measures,performing a reliable meta-analysis was considered impossible,so we present the studies,their results and limitations.RESULTS Eighteen preclinical studies and three review papers were identified;no clinical studies have been published and there are no registered clinical trials.Experimental studies,mainly in rat and porcine models and occasionally in very adverse conditions such as ischaemia or colitis,have been demonstrated SCs as safe and have shown some encouraging morphological,functional and even clinical results.Mesenchymal SCs are mostly employed,and delivery routes are mainly local injections and cell sheets followed by biosutures(sutures coated by SCs)or purely topical.As potential weaknesses,animal models need to be improved to make them more comparable and equivalent to clinical practice,and the SC isolation processes need to be standardised.There is notable heterogeneity in the studies,making them difficult to compare.Further investigations are needed to establish the indications,the administration system,potential adjuvants,the final efficacy and to confirm safety and exclude definitively oncological concerns.CONCLUSION The future role of SC therapy to induce healing processes in digestive anastomoses/sutures still needs to be determined and seems to be currently far from clinical use.  相似文献   

8.
BACKGROUND Despite overt insulin resistance,adipocytes of genetically obese Zucker rats accumulate the excess of calorie intake in the form of lipids.AIM To investigate whether factors can replace or reinforce insulin lipogenic action by exploring glucose uptake activation by hydrogen peroxide,since it is produced by monoamine oxidase(MAO)and semicarbazide-sensitive amine oxidase(SSAO)in adipocytes.METHODS 3H-2-deoxyglucose uptake(2-DG)was determined in adipocytes from obese and lean rats in response to insulin or MAO and SSAO substrates such as tyramine and benzylamine.14C-tyramine oxidation and binding of imidazolinic radioligands[3H-Idazoxan,3H-(2-benzofuranyl)-2-imidazoline]were studied in adipocytes,the liver,and muscle.The influence of in vivo administration of tyramine+vanadium on glucose handling was assessed in lean and obese rats.RESULTS 2-DG uptake and lipogenesis stimulation by insulin were dampened in adipocytes from obese rats,when compared to their lean littermates.Tyramine and benzylamine activation of hexose uptake was vanadate-dependent and was also limited,while MAO was increased and SSAO decreased.These changes were adipocyte-specific and accompanied by a greater number of imidazoline I2 binding sites in the obese rat,when compared to the lean.In vitro,tyramine precluded the binding to I2 sites,while in vivo,its administration together with vanadium lowered fasting plasma levels of glucose and triacylglycerols in obese CONCLUSION The adipocytes from obese Zucker rats exhibit increased MAO activity and imidazoline binding site number.However,probably as a consequence of SSAO down-regulation,the glucose transport stimulation by tyramine is decreased as much as that of insulin in these insulin-resistant adipocytes.The adipocyte amine oxidases deserve more studies with respect to their putative contribution to the management of glucose and lipid handling.  相似文献   

9.
The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that includes recreational and commercial fisheries. Due to river training and diversion structures constructed during the past 80 years, the historic characteristics of the LMR have been drastically altered and have likely influenced fishes and fisheries in the system. One common restoration measure used throughout the LMR has been to "notch" wing-dike structures that close secondary(side) river channels. Dike notching allows year-round flows through secondary channels, which enhances habitat diversity and promotes biological productivity at the ecosystem scale. Although notching is presumed good for LMR fishes and other biota, few studies have examined its effects on fish assemblages. In this study, fish assemblages were sampled at seven LMR secondary channels spanning from river kilometer(rkm) 628(Louisiana-Mississippi, U.S.A.) upstream to rkm 1504(Missouri-Kentucky, U.S.A.). Four secondary channels were termed "permanent"(i.e.,with notched dikes) while three secondary channels were termed "temporary"(i.e., without notched dikes).Fishes were sampled by boat-mounted electrofishing conducted during falling and low stages from1995—1997. Fish assemblages differed between permanent and temporary secondary channels, and varied somewhat between falling and low stages. Gizzard shad(Dorosoma cepedianum), threadfin shad(D. petenense), and white bass(Morone chrysops) demonstrated consistent preferences for low-current conditions associated with temporary secondary channels. Conversely, blue catfish(Ictalurus furcatus), flathead catfish(Pylodictis olivaris), and freshwater drum(Aplodinotus grunniens) were more associated with permanent secondary channels. Future restoration strategies in the LMR should consider dike notching and resultant maintenance of permanent secondary channels in selected river reaches. However, temporary secondary channels also contain unique fish species, and also appear to be important sites of riverine primary production. Restoration strategies should consider a balance of both secondary channel types, which should support the greatest biodiversity for the LMR ecosystem.  相似文献   

10.
通过观测可以确定向日葵的确具有明显跟随太阳旋转的向光性,但处于不同时期的向日葵有很大差异:处于花蕾早期的向日葵从日出到日落跟随太阳由东经南再向西运动且有明显的滞后现象.盛花期的向日葵花盘基本固定朝向东方,不跟随太阳运动,但仍有小范围偏转.  相似文献   

11.
药物经济学评价作为新兴学科,在目前如火如荼的仿制药一致性评价中得到广泛关注。文章在简介药物经济学评价基本方法的基础 上,对制药企业在仿制药一致性评价过程中的经济学问题及对策进行了探讨。  相似文献   

12.
对2015年1月30日召开的“创新药物研发高层论坛”的专家报告内容进行归纳总结,旨在为从事药品注册、创新药及仿制药研发、 药物临床试验质量管理规范(GCP)及药品非临床研究质量管理规范(GLP)工作的人士提供信息参考。  相似文献   

13.
基于各学科信息作出安全性、有效性和质量可控性方面的综合评价是新药研究评价的灵魂,是一个多学科、多组织参与的综合决策过程。根据新药评价研究的实际工作经验,介绍一个新药临床试验综合评价的逻辑性、结构性的工作思考模式,有助于将不同专业的技术信息和技术结论有机整合,作出科学决策。  相似文献   

14.
《基本医疗保险药品目录》的制定,对保证参保人员的合理用药需求、保障参保人员的合法权益以及降低不合理用药支出等方面具有重要作用。从临床实践的角度对2010版《江苏省医保药品目录》执行效果进行科学评价,探讨《医保药品目录》实施中存在的问题,为目录的调整提供政策建议。  相似文献   

15.
The light and scanning electron microscopic observations were carried out for anatomical features of leaf, pollens and powder.Microscopic studies provide useful information for identification and authentication of adulteration in A. maritima. Nutritional analysis of A. maritima revealed that life fundamental macromolecules such as carbohydrates (49.63 %) crude proteins (13.17 %) and crude fibers (21.06 %) were present in sufficient quantity while crude fats (4.11 %) reported in low quantity. The life essential elements such as Mg (9.472 ± 0.011), Ca (4.152 ± 0.135) and Fe (4.112 ± 0.002) were found in high concentration while heavy metals reported under the safety threshold of WHO. These observations favored A. maritima an alternative of food.Appreciable quantity of phenolics (17.64 ± 0.574) and flavonoids (7.67 ± 0.069) were found while qualitatively active phytochemicals were reported.The FTIR characterization of A. maritima crude powder revealed chromatogram in 3328.61 to 408.68 frequency range and 24 characteristic peaks on the basis of which different compounds of biological importance were classified. HPLC-UV technique quantifiedand identified six phenolic compounds morin,epigallocatechin gallate, catechin hydrate,ellagic acid, pyrogallol andrutin. Identification of compounds through GC–MS chromatogram revealed the presence of 46 compounds in methanolic fraction however 17 compounds of biological importance were selected.In-vitro biological evaluation of A. maritima for antioxidant, antimicrobial, antidiabetic (12.61 ± 0.113 %) and cytotoxic activities (LC50 = 20 μg/ml) suggested that methanolic fractions exhibited the highest activity as compared to chloroform and ethyl acetate fractions. The MIC values of 10 or 15 mg/ml were recorded for most of the fungal pathogens. Antibacterial activity revealed 3.75 mg/ml of MIC values against B. subtilis and 1.87 mg/ml against S. aureus, E. coli and P. aeruginosa. In-vivo biological evaluation revealed thatmaximum inhibition was observed for crude extract at 250 mg/kg body weight. The mechanism underlined in-vivo analgesic responses was carried out which revealed that naloxone (morphine and tramadol antagonist) showed no prominent effect while Glibenclamide pretreatment minutely modified the analgesic action. These observations clearly indicted the absence of opiod receptors and involvement of ATP sensitive potassium channels.  相似文献   

16.
为了促进合理用药,迫切需要开展面向住院患者的处方点评工作。探讨了如何将临床路径作为住院医嘱处方点评的工具,培训小组成员,制定规范性文件,通过PDCA戴明循环,建立住院病历医嘱处方点评体系。  相似文献   

17.
2016 年 3 月 5 日,国务院办公厅《开展仿制药质量和疗效一致性评价的意见》正式对外公布,提出了全面提高仿制药质量,开 展仿制药质量一致性评价,确保中国仿制药质量不低于美国、欧盟、日本的标准。文章介绍了美国和日本的一致性评价背景,根据中国国情, 结合政策法规,阐述如何科学性、合理性地开展仿制药一致性评价,重点介绍低剂量和微丸压片特殊口服固体制剂一致性评价的开发策略。  相似文献   

18.
目的:建立基于EGFP的、安全的抗人免疫缺陷病毒(HIV)药物评价系统。方法:用增强型绿色荧光蛋白(EGFP)基因替代HIV感染性克隆质粒pUC18-HIV-NL4-3中的部分包膜基因(env),构建重组假病毒质粒pUC18-NL4-3-EGFP,将其与水疱性口炎病毒糖蛋白(VSV-G)真核表达载体共转染人胚肾293FT细胞,观察绿色荧光蛋白的表达,同时用该细胞培养上清进一步感染其他293FT细胞培养物。为了检验该假病毒系统能否用于抗病毒药物的评价,在假病毒复制和感染过程中加入不同浓度的抗HIV药物AZT(Zidovudine),采用荧光显微镜检测和流式细胞仪定量检测,分析AZT对假病毒的抑制作用。结果:假病毒质粒pUC18-NL4-3-EGFP能够在转染细胞和再感染细胞中有效地表达绿色荧光蛋白基因,不同浓度的AZT能以剂量依赖方式抑制假病毒的感染和报告基因的表达。结论:建立了一种基于EGFP表达和检测的、安全的HIV假病毒复制和感染系统,该系统可以用于抗HIV药物的筛选和评价。  相似文献   

19.
为改善我国部分仿制药质量与国际先进水平还存在一定差距的现状,《国家药品安全“十二五”规划》中明确提出了开展仿制药一 致性评价,全面提高仿制药质量的任务。氯雷他定片作为抗过敏药物的主要品种之一,需在 2018 年底前完成一致性评价。基于现有质量和 疗效一致性评价指导原则与相关研究报道,针对氯雷他定原料药的晶型研究、原辅料杂质的比较研究、片剂溶出曲线的比较方法以及生物 等效性试验研究等进行了总结和概括,并对有待解决的共性问题进行了讨论。  相似文献   

20.
A simple procedure is described for the determination of the photosensitizing potency of drugs, using three leukemic cell lines, two of lymphocytic origin, L1210 and P388 and one of erythroid type, Friend-745. The procedure allows one to investigate several aspects of the photosensitization properties of tested compounds such as cellular localization and direct (trypan blue exclusion) or delayed (clonogenicity) photomediated toxicities.The method was assessed using crude hematoporphyrin derivative (HPD) as well as dihematoporphyrin ether (DHE) or commercially available Photofrin II. Results were compared to those obtained with normal cells, e.g spleen lymphocytes and erythropoietic stem cells (CFU-e), and discussed in the light of the relative response of normal versus transformed cells.Abbreviations DHE Dihematoporphyrin Ether - FCS Fetal Calf Serum - HPD Hematoporphyrin Derivative - PDT Photodynamic Therapy  相似文献   

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