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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.
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   

7.
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   

8.
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   

9.
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   

10.
<正>INTRODUCTION During our study of crustose lichens collected from Mt.Taibai,Shaanxi Province,we discovered an unusual species Orphniospora moriopsis (A.Massal.) D.Hawksw.It is characterized by the dark brown areolate thallus, black apothecia and brown spores.Orphniospora belongs to Fuscideaceae,Teloschistales,Lecanoromycetidae, Ascomycetes,Ascomycota (Kirk et al.,2001).The genus is reported from China for the first time.  相似文献   

11.
民族植物学—社会及文化价值初探   总被引:11,自引:0,他引:11  
简要介绍民族植物学的性质、研究现况及其在经济、生态、环境和学术上的应用情况。民族植物学的社会价值通过其在增强民族自信心、伦理学和知识产权等方面的作用得以论证。民族植物学的文化价值具体而生动,体现于种种直接的植物文化现象(如植物礼仪文化、食花文化、树叶信、草药文化等)和宗教行为(如植物图腾、树神崇拜、神林崇拜等)。通过对民族植物学的经济、生态价值和社会、文化价值的分析,作者相信,民族植物学对于文化多样性和生物多样性的保护将起到积极的作用。  相似文献   

12.
小良植被生态恢复的生态经济价值评估   总被引:14,自引:2,他引:12  
应用生态经济学的核算方法,对中国科学院小良热带人工林生态系统定位站植被生态恢复系统的服务功能进行了定量评估。结果表明,小良恢复生态系统具有极高的生态经济价值。以20世纪90年代不变价计,小良植被生态恢复系统43a的累积服务功能价值超过621亿元人民币。其中直接使用价值为7.65亿元,占总生态经济价值的1.23%,间接使用价值为613亿元,占总生态经济价值的98.77%,间接使用价值远远大于直接使用价值。间接使用价值中净化环境服务功能的生态经济价值,仅以固C、释放O2、吸收SO2和滞尘计,就已达577亿元。与此同时,小良热带沿海台地的植被恢复通过复合农林经营等渠道促进了当地生态、经济与社会的协同发展。  相似文献   

13.
An important application of decision analysis is determining the value that information has to a decision maker. The expected value of information (EVOI) is the expected increase in the value (or decrease in the loss) associated with obtaining more information about quantities relevant to the decision process. The EVOI can be thought of as a measure of the importance of the uncertainty about a quantity in terms of the expected improvement in the decision that might be obtained from having additional information about it. Examples of EVOI quantities useful in risk management situations include the expected value of including uncertainty (EVIU), the expected value of perfect information (EVPI), and the expected value of sample information (EVSI). Value of information (VOI) analysis is useful because it makes the losses associated with decision errors explicit, balances competing probabilities and costs, helps identify the decision alternative that minimizes the expected loss, prioritizes spending on research, quantifies the value of the research to the decision maker, and provides an upper bound on what should be spent on getting information.  相似文献   

14.
简述了医院开展价值工程的意义,对价值工程这一工程技术理论如何在医院管理中应用进行了探索,总结了医院的做法和实施效果,为提高医院管理水平,提升核心竞争力提供了一种新的角度。  相似文献   

15.
目的测定金黄地鼠的血液生理生化参考值,并对两性的参考值进行比较。方法将88只4周龄金黄地鼠,80只8周龄金黄地鼠,采血后,用日本光电MEK-7222K血球分析仪测定血液生理指标,用Olympus AU400全自动生化分析仪测定血清生化指标。结果4周龄金黄地鼠血液生理指标中RBC、HGB、HCT、MCV和RDW性别差异有显著性(P〈0.05),而WBC、MCH、MCHC、PLT、PCT、MPV和PDW等性别差异无显著性(P〉0.05);4周龄金黄地鼠血清生化指标中ALB、ALP、GLU、CA、P、CHO和TG性别差异有显著性(P〈0.05),而ALT、AST、TP、BUN和CREA等性别差异无显著性(P〉0.05)。8周龄金黄地鼠血液生理指标中WBC、LYM、MON、BAS、LYM%、NEUT%、MCH、RBC、HGB、HCT、MCV、PDW和RDW性别差异有显著性(P〈0.05),而MCHC、PLT、MPV、PCT、NEUT、EOS、BAS、MON%和EOS%等性别差异无显著性(P〉0.05);8周金黄地鼠血清生化指标中ALT、ALB、BUN、GLU、CREA、P、CHO和TG性别差异有显著性(P〈0.05),而AST、TP、ALP和CA等性别差异无显著性(P〉0.05)。结论金黄地鼠血液的生理生化值受多种因素影响,部分指标两性问测定值有差异,但多数指标差异不显著。  相似文献   

16.
王凤珍  周志翔  郑忠明 《生态学报》2011,31(7):1946-1954
城郊过渡带湖泊湿地面临着改善城市居民生活环境及满足城郊过渡带经济发展的双重压力,承担着更多样、更重要的生态服务功能,从生态服务功能价值分量的基础上探讨开发利用对策,可为其可持续开发利用提供依据。本文以武汉市城郊过渡带湖泊湿地严东湖为研究对象,基于市场价值法、影子工程法、旅行费用法、条件价值法等方法对严东湖生态服务功能的直接、间接使用价值及非使用价值进行了货币化计量。结果表明,严东湖生态服务功能的总价值为35799.09?104元?a-1,其中直接使用价值、间接使用价值及非使用价值分别为2628.80?104、2904.13?104、30266.16?104元?a-1,表现为非使用价值>间接使用价值>直接使用价值,且非使用价值约是其使用价值的5.5倍。12个单项指标中为存在价值最高;使用价值中为涵养水源价值>蒸腾吸热价值>均化洪水价值>休闲旅游价值>科研教育价值>物质生产价值>生物多样性维持价值>固碳释氧价值>水质净化价值;非使用价值中为存在价值>遗产价值>选择价值。因此,城市过渡带湖泊的开发利用应保护现有湖面的完整性,保持涵养水源、蒸腾吸热及均化洪水功能,弱化养殖类物质生产功能,适度发展休闲旅游功能,提高固碳释氧能力,并增强水质净化能力。  相似文献   

17.
蚯蚓的研究与应用   总被引:14,自引:0,他引:14  
从蚯蚓的营养价值、药用价值和生理特点等方面 ,介绍了蚯蚓在食品饲料、医药临床及环保中的应用研究现状 ,展望了蚯蚓开发利用的前景。  相似文献   

18.
圈养毛冠鹿血液生理生化指标测定   总被引:1,自引:0,他引:1  
本文采集了8只不同年龄段毛冠鹿的14个血液样品,并检测和分析了样品中的血细胞、血蛋白、电解质、生化酶类等44项指标的含量。初步建立了圈养毛冠鹿的血液学生理生化指标参考值,为今后加强毛冠鹿的人工饲养及繁育研究提供了参考依据。  相似文献   

19.
农业生态产品价值实现对我国粮食安全、生态保护、重要战略布局意义重大。本研究梳理了农业生产系统和农业生态产品(农产品、其他生态系统服务与负服务)的概念与边界,基于能值分析构建了农业生产系统所提供的服务核算方法体系,核算了我国单位面积典型农产品生态系统服务与负服务,并进一步提出分类化的农业生态产品价值实现路径: 1)已经通过市场化价值实现的农业生态产品需要通过提升绿色度、特殊度和建立农业产业链等实现溢价增值;2)尚未通过市场化价值实现的农业生态产品需要进行价值补偿途径,或通过生态产品赋能及区域共用品牌质量承诺实现价值变现;3)通过多途径减少温室气体排放、通过土地养分管理策略减少氮磷、农药、杀虫剂对生态系统和人群健康的损害,以及通过合理的景观结构减少农业生态系统负服务的产生,以此实现农业生态产品的价值保值;4)还可通过取消二次农业补贴、建立生态交易平台和生态产品认证等推动相关的金融方案。本研究有助于提出农业生态产品价值实现路径,促进绿色金融发展,推动自然资源管理能力现代化。  相似文献   

20.
东北草原盐碱植物虎尾草的热值和能量分配特征的研究   总被引:8,自引:0,他引:8  
虎尾草全株、茎和叶的热值的季节变化规律相似,从7月初至8月初出现2个峰值,然后呈逐渐下降趋势.穗的热值变化呈U字型,2个峰值分别出现在8月初和9月中旬.立枯体热值变化不规则,最大在8月初.虎尾草种群地上部能量的季节动态呈双峰曲线,峰值分别出现在8月初和9月初,最大值在9月初为7381.27kJ  相似文献   

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