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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.
本文记了分别采自云南高黎贡山的栅蛛科栅蛛属Hahnia 2新种:垭口栅蛛,新种S.yakouensis sp.nov.和肾形栅蛛,新种S.reniformis sp.nov..垭口栅蛛后眼列前曲,交媾腔大,扁圆形,交媾孔1个,位于交媾腔下缘,交媾管粗,呈"人"字形下行分成2支再向两侧扭曲.纳精囊有一肓管斜向上伸出,鉴于上述特征而与Hahnia mridulae Tikader,1970不同.肾形栅蛛交媾孔2个,位于生殖厣腹面中央,纳精囊1对,大,肾形,插入器始于生殖球左下方,鉴于上述特征而与Hahnia xinjiangensis Wang et Liang,1989不同. Abstract: The present paper deals with two new species of the genus Hahnia collected from the Gaoligong Mountains Region of Yunnan Province, China: Hahnia yakouensis sp. nov., Hahnia reniformis sp. nov..  相似文献   

5.
中国医科大学博士后科研流动站始建1995年。目前学校设有基础医学、临床医学和生物学3个博士后科研流动站。但由于每年国家财力有限,资助名额很少,在有限条件下建立、健全博士后制度,加强对博士后人员的培养,调动博士后人员的积极性是一项重要的研究课题。  相似文献   

6.
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   

7.
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   

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.
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   

10.
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   

11.
庐山蕨类植物区系研究   总被引:2,自引:1,他引:1  
庐山共有蕨类植物39科87属247种(含变种、变型),其区系带有热带和温带双重性。其中鳞毛蕨科、水龙骨科、蹄盖蕨科、金星蕨科和铁角蕨科属种优势明显,共有38属160种,分别占总属数的43.7%和种数的64.8%,代表了该地区蕨类植物区系的一个重要特征。该区区系地理成分复杂,相互交错,其中热带性属占总属数的64.2%,温带性属占总属数的35.8%。东亚成分在该区系占有绝对优势,共有14属,占总属数的20.9%,中国特有属缺乏,特有种丰富,表明成分具有多样性并具有热带亲缘性,是亚热带向北温带的过渡地区。该区与井冈山、武夷山关系密切,与鼎湖山、秦岭和横断山关系疏远。  相似文献   

12.
广西湿地水生维管束植物区系研究   总被引:1,自引:0,他引:1  
初步得出广西地区湿地水生维管束植物共有63科163属412种,其中蕨类植物6科6属13种,种子植物57科157属399种。按植物形态特征和生态习性划分,广西湿地水生维管束植物可分为湿生植物、挺水植物、浮叶植物、漂浮植物、沉水植物5种类型。分析表明:该区水生维管植物区系的地理成分复杂,联系广泛。热带性质的属有93属,占总属数的78.15%,温带性质的属有25属,占总属数的21.01%;热带性质的种有180种,占总种数的53.73%,温带性质的种有101种,占总种数的30.15%,表明该地区植物区系具有明显的热带性质,这与广西所处的气候带相一致。世界分布属有44属,世界分布种有77种,分别占总属数和总种数的26.99%和18.69%,它们是湿地植被的主要组成成份或关键属(种)。特有属种匮乏。此外,还对区系中受危种和外来种进行了讨论。  相似文献   

13.
广东深圳塘朗山郊野公园共有野生维管植物144科423属611种,分别占广东省维管植物280科1589属5737种的51.4%、26.7%和10.65%;其中蕨类省植物21科29属33种,裸子植物3科3属4种,被子植物120科391属574种,被子植物占绝对优势。国家重点保护野生植物共计7科7属7种,占广东省国家重点保护野生植物的10.9%;珍稀濒危植物有4科5属5种,占广东省珍稀濒危植物67种的7%。公园中经济植物可分为12类,分别是药用植物321种,用材树种65种,观赏植物60种,纤维植物41种,野生水果33种,油脂植物38种,饲料植物42种,鞣料植物42种,野菜植物25种,农药植物27种,芳香植物26种,淀粉植物23种,保健植物19种,染料植物13种,有毒植物10种,蜜源植物5种。  相似文献   

14.
This checklist comprises all species of Hydrophilidae (Coleoptera: Hydrophiloidea) quoted in the literature referring to Iran and confirmed by our study. In total, 104 species within 17 genera and five subfamilies, Hydrophilinae (eight genera, 63 species), Chaetarthriinae (three genera, five species), Enochrinae (single genus, 20 species), Acidocerinae (single genus, three species) and Sphaeridiinae (four genera, 13 species), are listed for the fauna of Iran. Three species are endemic; four species are recorded here for the first time from Iran, and nine species are excluded from Iranian fauna.  相似文献   

15.
北京山区野生维管束植物区系   总被引:10,自引:1,他引:9  
在北京山区共有高等植物1166种(含变种、变型),隶属于122科、503属;其中蕨类植物17科、26属、62种(变种),裸子植物3科、7属、7种;双子叶植物88科、371属、863种(变种);单子叶植物14科、99属、234种(变种)。优势科属的统计表明,本区维管束植物一方面集中于菊科、蔷薇科等一些世界性大科之中,同时又向少种科、单种科分散。在北京山区共调查到1个单种科,6个单属科。本区分布的单种属和寡种属共72个,其中单种属有31个。种子植物属的分布区类型占有全国植物科的15个分布区类型,以温带成分的属为主,其占种子植物总属数的55.34%;其次是泛热带分布类型,共计60属,占总属12.6%,中国特有分布的属有11属,占总属数的2.31%,所占比例较小。  相似文献   

16.
张红梅  陈浒  陈静  郭城  黄菊 《西北植物学报》2020,40(10):1768-1777
为了明确毕节喀斯特石漠化地区的植物资源及区系特征,该研究于2018年、2019年分别采用样线和样方法对研究区的野生植物资源进行调查,同时通过标本采集、文献查阅等方法对研究区的植物资源及区系进行分析,为喀斯特石漠化治理及生态保护提供理论依据。结果表明:(1)研究区植物总计133科438属721种,其中蕨类10科13属16种,裸子植物7科9属11种,被子植物116科417属695种;被子植物中,单子叶植物15科75属121种,双子叶植物101科342属574种;珍稀濒危植物共35种,隶属于14科24属。(2)资源植物分类中,药用类植物121科339属516种,蜜源植物74科180属333种,食用类植物37科60属75种,观赏类植物75科146属209种,纤维类植物42科82属89种,淀粉和糖料类植物21科37属59种,芳香油类植物25科88属132种,油脂类植物63科117属144种,树脂及树胶类植物17科17属22种,鞣料类38科63属87种,其他植物资源合计68科128属155种。(3)植物区系上蕨类植物的科、属区系分化小,种子植物科的区系划分为9个分布区类型、9个亚型,以热带成分为主;属级水平上共15个分布区类型、20个亚型,属水平上温带成分占优势。研究表明,研究区植物资源种类丰富,植物区系具有温带和热带双重性质和过渡性特征。  相似文献   

17.
金则新  柳宝林   《广西植物》2007,27(3):420-425
台州市种子植物丰富,据统计有野生种子植物150科、784属、1892种(含种下分类群),其中裸子植物6科、12属、16种,被子植物144科、772属、1876种。优势科明显,其中10种以上的科有45个,含526属、1453种,分别占总属数、总种数的67.09%、76.80%。本区系历史悠久,起源古老,小属和极小属共707个,占总属数的90.18%。科的分布区类型以热带、亚热带分布最多,其次是世界分布,第3是温带分布。属的分布区类型可划分为14类,以温带性成分为主,也兼有相当比例的热带性成分,具有亚热带特性。地理成分复杂,与世界各地联系广泛。该地区有中国特有属14属,列为国家首批保护的珍稀植物20种。  相似文献   

18.
江西国家重点保护野生植物的时空分析   总被引:3,自引:0,他引:3  
臧敏  黄立发  李典友  毛尚俊  邱筱兰  凌云   《广西植物》2007,27(1):77-83,70
江西省国家重点保护野生植物29科45属53种,其中蕨类植物4科5属7种,裸子植物6科11属13种,被子植物19科29属33种;国家重点保护野生植物中单属科和单种科各8个,中国特有科3个,单种属15个,中国特有属16个,分布区类型12个,其中以热带或以热带分布为主的属占总属数的26.67%;以温带或以温带分布为主的属占31.11%;中国特有分布最突出,占35.56%。特有属分布型6个,与华中、西南关系最密切。同时,采用综合指数和相似度,把江西省与各省区比较,结果表明:江西省国家重点保护植物十分丰富,江西省植物区系与其周边省份关系最密切。  相似文献   

19.
山西湿地维管植物区系多样性研究   总被引:5,自引:1,他引:4  
山西省湿地有维管植物686种,隶属于308属, 83科。其中蕨类植物8科10属, 18种;双子叶植物56科, 223属, 504种;单子叶植物19科, 75属, 164种。在山西省湿地维管束植物属的分布区类型中,温带性质的属有108属,占主导地位,除去世界分布属,所占比例达76.9%,反映出山西湿地维管束植物的分布与本地所处的气候带相适应。世界分布有74属,占总属数的24%,也是湿地植被的主要组成成分或关键属。特有属匮乏。  相似文献   

20.
美姑大风顶自然保护区种子植物区系分析   总被引:8,自引:1,他引:7  
四川美姑大风顶国家级自然保护区有种子植物 1 1 8科 ,3 85属 ,860种 ,其中裸子植物 5科 ,1 6属 ,1 9种 ;被子植物 1 1 3科 ,3 69属 ,841种。种子植物属、种的区系成分共有 1 3个类型 ;在所有成分中 ,以温带区系成分为主 ,达 1 81属 ,占总属数的 5 1 .5 8%。中国特有分布属共 1 1属 ,占总属数的 3 .1 3 % ;中国特有分布种共41 0种 ,占总种数的 48.41 %。保护区共有珍稀濒危植物 1 8种 ,其中国家一级保护植物 4种 ,国家二级保护植物 6种 ,国家三级保护植物 8种。  相似文献   

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