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1.
目的了解实验所用常见致病真菌能否在常用医用原材料上生存及生存时间。方法选择8种常见致病真菌,活化后将它们分别接种在5种常用的医用原材料上,接种后及以后的每24h将接种有真菌的医用材料放入巯基乙酸盐液体培养基中并观察能否生存,记录存活时间。结果红色毛癣菌和须癣毛癣菌在棉布、纸板、铁皮、玻璃表面存活25~28d,在地板胶表面存活14~15d;新生隐球菌在棉布、纸板、铁皮表面存活24~27d,在玻璃和地板胶表面存活14~18d;茄病镰刀菌在上述5种材料上存活22~27d;石膏样小孢子菌在棉布、纸板、铁皮和玻璃表面存活20~27d,在地板胶表面存活8d;申克孢子丝菌在棉布、纸板、玻璃和地板胶表面存活17~24d,在铁皮表面存活10d;白念珠菌在棉布、纸板、铁皮和地板胶表面存活15~20d,在玻璃表面存活4d;犬小孢子菌在棉布、纸板、铁皮、玻璃和地板胶上存活时间分别为10d、9d、3d、2d和1d。结论实验所用各种真菌在医用原材料上都能存活,其时间长短不仅与菌种有关,还与所存在的材料有关。真菌在吸水性强、表面粗糙的材料(棉布、纸板)上的平均存活时间长于在吸水性差、表面光滑的材料(玻璃、铁皮和地板胶)。  相似文献   

2.
通过田间采集调查、室内饲养和鉴定,得出福州地区48种植物上的粉虱17种,5种为福建新记录。其中果树上的粉虱有11种,农作物上的粉虱3种,花卉上的粉虱7种,其他植物上的粉虱10种。  相似文献   

3.
转基因植物对农业生物多样性的影响   总被引:17,自引:3,他引:17  
论述了近年来转基因植物对农业生态系统生物多样性影响的研究进展.主要在遗传多样性、物种多样性和生态系统多样性3个层次上予以评述.包括转基因植物对作物遗传多样性的影响;转基因植物的外源基因向杂草和近缘野生种转移;转基因抗虫植物对目标害虫的影响。抗除草剂转基因植物对作物和杂草的影响,抗病毒转基因植物对病毒的影响;转基因植物对非目标生物的影响,对土壤生态系统的影响等.  相似文献   

4.
为了解属模巨齿蛉成虫多个部位感器的超微结构及其对生命活动的影响,本文对属模巨齿蛉成虫的触角、大颚、翅缘和生殖器4个部位进行了电镜扫描。研究发现,触角有7种感器,分别是毛形感器Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型、腔锥感器、锥形感器、柱形感器;大颚有3种感器,分别是腔锥感器、锥形感器、刺形感器;翅缘有4种感器,分别是毛形感器Ⅱ型、Ⅲ型、Ⅳ型、腔锥感器;雌性成虫生殖器有7种感器,分别是毛形感器Ⅱ型、Ⅲ型、Ⅳ型、Ⅴ型、Ⅵ型、锥形感器、钟形感器。柱形感器是触角的特殊感器,钟形感器是雌性成虫生殖器的特殊感器。毛形感器是触角、翅缘和生殖器主要感器,而大颚上没有毛形感器。触角和生殖器上的感器类型最多,且分布最密集,这与触角和生殖器对成虫的交配、产卵行为具有重要作用相吻合。  相似文献   

5.
高浓度O3对树木生理生态的影响   总被引:3,自引:0,他引:3  
目前全球范围内的O3污染日趋严重,特别是随着城市化的不断发展和大气O3浓度的不断升高,O3对植物的影响已越来越引起人们的关注.O3可以通过多种方式影响森林树木.结合近年来对城市森林主要树种与气候变化关系的研究和相关文献调查,综合报道和分析了国内外高浓度O3对森林树木生理生态影响研究的最新进展,具体包括高浓度O3对树木的可见伤害、树木的生长和形态结构、光合作用、物质代谢、抗氧化系统及其与其它生态因子(如温度、干旱、CO2等)复合作用对树木生理生态的影响.提出了一些目前研究中存在的主要问题和研究展望.这些报道为进一步开展高浓度O3对树木的生理生态学研究,特别是为全球气候变化背景下城市森林的可持续经营与管理以及树种选择提供科学参考和理论依据.  相似文献   

6.
草原蘑菇圈对牧草长势影响的初步分析   总被引:10,自引:0,他引:10  
在白蘑,黄蘑圈上,圈内及圈外分别作测产样方,分析它们之间的差异。结果表明:白蘑,黄蘑圈均可极显著地提高群落地上生物量。其对羊草的影响较显著,圈上羊草的生物量,株高,密度及单株重均明显高于对圈内,圈外;对黄囊苔草和其它植物的影响不明显。白蘑圈对羊草的影响较黄蘑圈小。  相似文献   

7.
This paper is a preliminary report on the development of a new instrument, the Impact of Weight on Quality of Life (IWQOL) questionnaire, that assesses the effects of weight on various areas of life. We conducted two studies utilizing subjects in treatment for obesity at Duke University Diet and Fitness Center. The first study describes item development, assesses reliability, and compares pre- and post-treatment scores on the IWQOL. In the second study we examined the effects of body mass index (BMI), gender, and age on subjects' perceptions of impact of weight on quality of life. Results indicate adequate psychometric properties with test-retest reliabilities averaging .75 for single items, and .89 for scales. Scale internal consistency averaged .87. Post-treatment scores differed significantly from pre-treatment scores on all scales, indicating that treatment produced positive changes in impact of weight on quality of life. The results of the second study indicate that the impact of weight generally worsened as the patients' size increased. However for women there was no association between BMI and impact of weight on Self-Esteem and Sexual Life. Even at the lowest BMI tertile studied, women reported that weight had a substantial impact in these areas. There were also significant gender differences, with women showing greater impact of weight on Self-Esteem and Sexual Life compared with men. The impact of age was a bit surprising, with some areas showing positive changes and others showing no change.  相似文献   

8.
夏季绿洲生态环境对荒漠背景地表能量过程的扰动   总被引:1,自引:0,他引:1  
张强  王胜 《生态学报》2005,25(10):2459-2466
利用观测试验资料,对比分析了夏季典型晴天敦煌绿洲与周围荒漠戈壁背景地表过程的差异,揭示了绿洲生态系统对干旱区荒漠背景地表过程的扰动特征。结果表明:绿洲地表净辐射日平均要高出周围荒漠戈壁背景60 W/m2以上,约占绿洲净辐射的1/4以上。对绿洲高出的净辐射贡献最大的是绿洲相对低的地表长波辐射,其次是较高的太阳总辐射。而绿洲相对较低的大气长波辐射对高出的净辐射有较大的负贡献,特别是地表反射辐射也有很小的负贡献。绿洲高出的地表净辐射主要贡献于加强潜热和地热流量,还有一部分被绿洲地表能量不平衡差额所占,它实际上可能由一般地表热量平衡所不考虑的垂直热量平流来输送。而绿洲明显低于荒漠背景的感热通量则节省了一部分净辐射能量。  相似文献   

9.
在室内研究了水稻品种形态特征对褐飞虱卵在稻株上的分布以及由此而对稻虱缨小蜂功能反应的影响.结果表明,在所有测试品种中,褐飞虱卵在稻株上的垂直分布型可归为3类,即上中部为主分布型、中下部为主分布型和均匀分布型.稻株上、中、下各部位的褐飞虱卵量多少与其相应部位叶鞘鞘脊的相对高度呈极显着正相关.稻虱缨小蜂对上中部为主分布型褐飞虱卵(在浙农大40上)的功能反应明显地强于对中下部为主分布型的褐飞虱卵(在浙852上).  相似文献   

10.
红火蚁Solenopsis invicta Buren是一种对人类健康、生态环境等具有严重危害的重大入侵害虫,毒饵诱杀是防控红火蚁的重要手段.在采用人工撒施方法时,如何避免药剂浪费或不足仍需研究.本文研究了红火蚁饵剂药瓶瓶盖出药量与瓶盖上孔洞直径、孔洞数量和施药方式的关系,为红火蚁饵剂施药装置选择合适的孔洞直径、孔洞数...  相似文献   

11.
水稻品种形态特征对稻虱缨小蜂功能反应的影响   总被引:9,自引:1,他引:8  
在室内研究了水稻品种形态特征对褐飞虱卵在稻株上的分布以及由此而对稻虱缨小蜂功能反应的影响.结果表明,在所有测试品种中,褐飞虱卵在稻株上的垂直分布型可归为3类,即上中部为主分布型、中下部为主分布型和均匀分布型.稻株上、中、下各部位的褐飞虱卵量多少与其相应部位叶鞘鞘脊的相对高度呈极显著正相关.稻虱缨小蜂对上中部为主分布型褐飞虱卵(在浙农大40上)的功能反应明显地强于对中下部为主分布型的褐飞虱卵(在浙852上).  相似文献   

12.
Germination of conidia of Entomophaga maimaiga, an important fungal pathogen of gypsy moth, Lymantria dispar, was investigated on water agar and larval cuticle at varying densities. Percent germination was positively associated with conidial density on water agar but not on larval cuticle. When conidia were showered onto water agar, the rate of germination was much slower than on the cuticle of L. dispar larvae. From the same conidial showers, the resulting conidial densities on water agar were much higher than those on larval cuticle in part because many conidia adhered to setae and did not reach the cuticle. A second factor influencing conidial densities on larval cuticle was the location conidia occurred on larvae. Few conidia were found on the flexible intersegmental membranes in comparison with the areas of more rigid cuticle, presumably because conidia were physically dislodged from intersegmental membranes when larvae moved. Conidia were also exposed to heightened CO(2) to evaluate whether this might influence germination. When conidia on water agar were exposed to heightened CO(2) levels, germinating conidia primarily formed germ tubes while most conidia exposed to ambient CO(2) rapidly formed secondary conidia.  相似文献   

13.
环境工程微生物学实验教学内容优化研究   总被引:2,自引:0,他引:2  
本文从实验教学计划、教学内容、教学手段和考核评价体系等多方面对环境工程微生物学实验教学进行了改革和调整,增设了综合和设计性实验,注重实验内容在生活和环境污染治理中的体现和应用,注重学生对实验内容理论知识的理解和掌握,强调学生参与实验的准备工作以及实验考核评价体系的优化等环节。 更多还原  相似文献   

14.
The antibiotic 2,4-diacetylphloroglucinol (DAPG), produced by some strains of Pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. The primary objective of this study was to determine whether Wood1R, a D-genotype strain of DAPG-producing P. fluorescens, suppresses numbers of both sedentary and migratory plant-parasitic nematodes. An experiment was conducted in steam-heated soil and included two seed treatments (with Wood1R and a control without the bacterium) and six plant-nematode combinations which were Meloidogyne incognita on cotton, corn, and soybean; M. arenaria on peanut; Heterodera glycines on soybean; and Paratrichodorus minor on corn. Wood 1R had no effect on final numbers of M. arenaria, P. minor, or H. glycines; however, final numbers of M. incognita were lower when seeds were treated with Wood1R than left untreated, and this reduction was consistent among host plants. Population densities of Wood1R were greater on the roots of corn than on the other crops, and the bacterium was most effective in suppressing M. incognita on corn, with an average reduction of 41%. Despite high population densities of Wood1R on corn, the bacterium was not able to suppress numbers of P. minor. When comparing the suppression of M. incognita on corn in natural and steam-heated soil, egg production by the nematode was suppressed in natural compared to steamed soil, but the presence of Wood1R did not result in additional suppression of the nematodes in the natural soil. These data indicate that P. fluorescens strain Wood1R has the capacity to inhibit some populations of plant-parasitic nematodes. However, consistent suppression of nematodes in natural soils seems unlikely.  相似文献   

15.
高寒草甸退化对短穗兔耳草克隆生长特征的影响   总被引:2,自引:2,他引:2  
以调查统计和比较样地法研究了江河源区高寒草甸退化对典型匍匐茎植物短穗兔耳草克隆生长特征的影响。结果表明,退化草甸的植物群落结构、功能以及土壤特征发生了明显地变化,继而对短穗兔耳草无性系的克隆生长行为和形态特性产生了影响。高寒草甸退化后短穗兔耳草的匍匐茎有所增多,分支强度加大。退化草甸内短穗兔耳草的基株高度小于未退化草甸,根长大于未退化草甸,基株的叶片数目间没有明显差别。退化草甸内短穗兔耳草的分株高度显著小于未退化草甸,分株叶数明显多于未退化草甸,而根长尽管大于未退化草甸,但差异不显著。短穗兔耳草匍匐茎长度在未退化草甸内明显大于退化草甸,匍匐茎茎生叶数和匍匐茎粗度也在未退化草甸大于退化草甸。短穗兔耳草在未退化草甸用于克隆繁殖的能量投资比例高于退化草甸,其中未退化草甸内短穗兔耳草基株的干重比例略低于退化草甸,分株和匍匐茎的干重比例高于退化草甸。高寒草甸退化对短穗兔耳草克隆生长特征的这些影响,是其对高寒草甸退化导致的资源和生境差异的反应,也是对资源利用达到的最合理状态,是一种选择适应的结果。  相似文献   

16.
陈立红  闫伟 《植物学报》2003,20(1):94-97
在黑蘑圈上、圈内及圈外分别作测产样方,分析它们之间的差异。结果表明:黑蘑圈可极显著地提高群落地上生物量。其中对羊草(Leymus chinensis)的影响较大,圈上羊草的 生物量和密度均明显高于圈内、圈外;对其它植物的影响不明显。黑蘑圈可增强植物的吸水力和储水力。  相似文献   

17.
In experiments on isolated segments of the rat femoral artery, we demonstrated that a donor of nitric oxide, nitroglycerine (NG), suppresses KCl-and phenylephrine-induced contractions of smooth muscles (SMs) of the vascular wall in a dose-dependent manner. The relaxing effect of NG on SMs is based on several mechanisms. In a series of experiments on intact preparations, we found that potassium channels of two types, Ca-dependent big-conductance and inward rectifying channels, are involved in the relaxing effect of NG. Experiments on skinned preparations showed that interaction between the contractile apparatus of SM cells and calcium ions is disturbed under the action of NG. Neirofiziologiya/Neurophysiology, Vol. 39, No. 3, pp. 208–213, May–June, 2007.  相似文献   

18.
The work presents data indicating no dependence of the pacemaker activity located in the zone of junction of cat ureter with urinary bladder on genesis of the main perirenal pacemaker. Data are presented on effect of clamping the renal artery supplying with blood flow the renal area on rhythmogenesis of the ureter perivesicular area. An inhibition of the pacemaker activity of the pyeloureteral anastomosis is observed. At the same time, no marked effect on automatism of the low organ area is revealed. Data of morphological studies of the vascular bed providing blood supply of various ureter areas are presented.  相似文献   

19.
Hypromellose (hydroxypropyl methylcellulose, HPMC) matrices are widely used in the formulation of sustained release dosage forms. The integrity and performance of an HPMC matrix formulation depends on rapid hydration and gel formation upon ingestion. Due to the recent alert issued by the Food and Drug Administration regarding the potential negative influence of alcoholic beverages on extended release (ER) formulations, several researchers have evaluated the potential influence of hydroalcoholic media on drug release from ER dosage forms. It has been reported that HPMC matrix formulations do not show “dose dumping” in hydroalcoholic media. The purpose of this study was a fundamental investigation on the effect of hydroalcoholic solutions (0–40% v/v ethanol) on textural and rheological properties of different viscosity grades of neat HPMC, as the functional ingredient within a hydrophilic matrix. In general, hydroalcoholic solutions had little effect on gel formation and mechanical properties of hydrated compacts, while the rheological behavior of HPMC showed dependency on the ethanol content of such solutions.  相似文献   

20.
Our previous reports have shown that lamininglycopeptides (LN-GPs),the total glycopeptides prepared from laminin (LN),can prevent the experimental lung metastasis and liver metastasis of mouse cancer cells.In order to explore the anti-metastatic mechanism of LN-GPs,we studied the effects of LN-GPs on metastasisrelated behaviors of cancer cells in vitro.LN-GPs did not affect cell survival.However,LN-GPs inhibited cell attachment and spreading of S180 cells on LN-and Matrigelsubstrate in dose-dependent and time-dependent manners.Moreover,inhibition of cell attachment and spreading on Matrigel substrates were much greater on Matrigel substrate than on LN substrate.In the gresence of LN-GPs,S180 cells on LN substrate changed from a flattened polygonal shape to a round one,the migration of S180 cells on LN substrate decreased,and the number of a highly invasive human pulmonary giant carcinoma PG cells invading Matrigel filter in a Boyden chamber was reduced.LN-GPs thus have multiple inhibitory effects on cancer metastasisrelated behaviors.  相似文献   

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