检索结果-南通市图书馆

Inactivation of Cryptosporidium by ozone and cell ultrastructures

Journal of Environmental Sciences 2010年第12期22卷 1954-1959页

作者： Zhilin Ran Shaofeng Li Junli Huang Yixing Yuan Chongwei Cui Craig Denver Williams School of Municipal & Environmental Engineering Harbin Institute of Technology Harbin 150090 China Department of Building & Environmental Engineering Shenzhen Polytechnic Institute Shenzhen 518055 China School of Applied Science University of Wolverhampton Wolverhampton WV1 1LY UK

The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mechanism of inactivation preliminarily. Results indicated that O3 had a stronger inactivating capability. When the concentration of O3 was above 3.0 mg/L and the contact time was up to 7 min, a significant inactivating effect could be achieved. The turbidity on inactivation effects was also found to be statistically significant in artificial water. With increases in turbidity, the inactivating effect decreased. Inactivation rate improved with a temperature increase from 5 to 25℃, but decreased beyond this. The inactivating capability of O3 was found to be stronger under acidic than that under alkalic conditions. When the concentration of organic matter in the reaction system was increased, the competition between Cryptosporidium and organics with O3 probably took place, thereby reducing the inactivation rate. In addition, the cellular morphology of Cryptosporidium varied with different contact times. At zero contact time, cells were rotundity and sphericity, at 60 sec they became folded, underwent emboly, and burst at 480 sec, the cell membrane of Cryptosporidium shrinked and collapsed completely.

关键词： ozone inactivation Cryptosporidium ultrastructures

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the ultrastructures of Antennal Sensilla in Helicoverpa armigera

引用

Agricultural Sciences in China 2002年第8期1卷 896-899页

作者： WANG Gui-rong, GUO Yu-yuan and WU Kong-ming( State Key Laboratory of Plant Disease and Insect Pests, The Institute of Plant Protection , Chinese Academy of Agricultural Sciences, Beijing 100094 , P. R . China ) State Key Laboratory of Plant Disease and Insect Pests The Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing 100094 P. R . China

The morphology and structures of antennal sensilla of Helicoverpa armigera are observed under scanning and transmission electron microscopes. Antennae of Helicoverpa armigera are made up of scapus, pedicel and flagellum that the latter consists of 70 - 82 segments. The inner side surface of antenna is cat-aphracted and most of the antennal sensilla lie on its outer, upper and lower surfaces. Both the antennae of male and female contain five kinds of antennal sensilla, namely, sensillum trichodeum, sensillum basicon-icum, sensillum chaeticum, ear-shaped sensillum and sensillum coeloconicum, and the kinds, number and distribution of antennal sensilla of both sexes are similar. There are a large number of serrate cuticular processes on antennal surface, especially on the middle and basic parts of antenna. Sensillum trichodeum and sensillum basiconicum, the main chemical odor receptors on antennae of Helicoverpa armigera, consist of cuticular-wall, sheath cells, lymph and dendrites. There are significant differences between the internal structures of the two kinds of sensilla. In sensillum trichodeum, the cuticular-wall is thicker, less lipophilic pore channels and has one or a few dendrites, while in sensillum basiconicum, the cuticular-wall is thinner, abundant lipophilic pore channels and has much more dendrites.

关键词： Helicoverpa armigera Antennal sensillum ultrastructures Scanning electron microscope Transmission electron microscope

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Iron chelator daphnetin against Pneumocystis carinii in vitro

引用

Chinese Medical Journal 2004年第11期117卷 1704-1708页

作者：叶彬郑玉强武卫华张静 Department of Parasitology Chongqing University of Medical SciencesChongqing 400016China Department of Laboratory Medicine Children’s HospitalChongqing University of Medical SciencesChongqing 400014China

Background Although there are several drugs and drug combinations for the treatment of Pneumocystis carinii (P. carinii) pne umonia, all drugs have the toxicity as well as low efficacy. Iron chelators have been proposed as a source of new drugs for combating these infections. We hypothesized that iron chelators would suppress the growth of P. carinii by deprivation of the nutritional iron required for growth. In this study, a short-term axenic culture system of P. carinii was established. Daphnetin (7,8-dihydroxycoumarin), a known iron chelator, was demonstrated to exhibit in vitro activity against P. carinii in this system. Methods P. carinii organisms were obtained from the lungs of immunosuppressed rats. The culture system consisted of Iscove Dulbecco Eagle’s Minimum Essential Medium (IMDM), supplemented with S-adenosyl-L-methionine, N-acetylglucosamine, putrescine, L-cysteine, L-glutamine, 2-mercaptoethanol, and fetal bovine serum, and was maintained at 37℃, in 5% CO 2, 95% O 2, at the optimal pH of 8.0. The culture system was used to assess the effect of daphnetin on the proliferation of P. carinii organisms. The ultrastructures of the treated organisms were observed by transmission electron *** The number of cysts and trophozoites increased 8- to 9-fold and 11- to 12-fold, respectively, after 10 days of culture. Daphnetin was found to suppress the growth of P. carinii in a dose-dependent manner at concentrations between 1 μmol/L and 20 μmol/L. The inhibitory activity was suppressed by the chelation of daphnetin with ferrous sulfate in a 2∶1 molar ratio, but it was not suppressed by mixing the culture medium with magnesium sulfate. Reduction of P. carinii numbers after treatment with daphnetin correlated with morphological changes in the organisms, as determined by transmission electron *** Daphnetin can suppress the growth of P. carinii in vitro. The efficacy o f daphnetin in suppressing the the growth of P. carinii i

关键词： Pneumocystis carinii daphnetin ultrastructures

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cellular Changes in Pulmonary Tissues of Guinea Pigs Cavia Porcellus Exposed to Diesel Exhaust Emitted （DEE）

引用

Journal of Environmental Science and Engineering(B) 2012年第12期1卷 1344-1354页

作者： Nahid N Almanea Noorhan A Chelebi Suzanne A Bazzaz Ayoub A Bazzaz Department of Biology Faculty of Sciences University of Taibah AI-Madinah Al-Munawarah KSA Department of Biochemistry Institute of Biological Sciences University of Liverpool Liverpool L69 3ZB UK Department of Surgery Southbourne Hospital Fisherman Avenue Bournemouth BH6 3SQ UK

DEE （diesel exhaust emitted） and fossil fuel do contribute to the pollution of ecosystem while very little is known about their toxic effects on pulmonary tissue in the short-term. Ten male Guinea pigs exposed to DEE in an open system experiment at different time schemes and their tracheas and lungs were processed for routine Histology, Immunohistochemsitry and TEM （transmission Electron Microscopy） techniques. The results revealed early toxicological effects of DEE on pulmonary tissue involved cellular damages to the mucosa of trachea and bronchial tree, rupture of alveolar walls, disintegration of pneumocytes, development of mucous secretions, swellings in the alveolar network, hemorrhage and lymphatic infiltration all over the parenchyma starting from the early hours of exposure to DEE. Ultrastructural changes confirmed the ruptures to the alveolar walls, infiltration of various WBC （white blood cells）, development of vacuoles inside the cytoplasmic organelles of pnemocytes, distortion in morphology of both RBCs （Red Blood corpuscles） which all had begun as early as 1 h following the exposure to the DEE. Activation of the immune system was noted via the increase in size of lymph nodules to confront the invaded particulates. These results indicate blockage of the respiratory leading to suffocation and do alert the expected acute cellular harms to the pulmonary tissues following exposure to the DEE of mechanics work in vicinity of DEE who spend most daily hours in semi-closed areas.

关键词： ultrastructures DEE guinea pigs air pollution.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mechanism of Solanum rostratum Dunal Seed Germination

Mechanism of Solanum rostratum Dunal Seed Germination

引用

第十一届全国杂草科学大会

作者：杨龙魏守辉 Hongjuan Huang Zhaofeng Huang Jingchao Chen Jinyi Chen 张朝贤中国农业科学院植物保护研究所 Institute of Plant Protection Chinese Academy of Agricultural SciencesKey Laboratory of Integrated Pest Management in CropsMinistry of Agriculture

Background and Aims Many domesticated Solanaceae seeds’ morphology and physiology have been widely studied but little in Solanum rostratum *** present study aimed to investigate the morphology and the physiology of germination of *** seeds,which is an important invasive species in *** Morphological parameters of fruits and seeds were determined by *** was monitored for 15 d under three different *** digestion and resistance,with endo-β-mannanase activity and required force to puncture the endosperm cap were measured during imbibition in water,gibberellins and in abscisic *** Results Seed coat surface ultrastructures,which are fingerlike projections,titled holes and concave grooves,may influence the ability of seed to germinate through interference with water uptake,gas *** endosperm cap appears to impose a mechanical resistance on *** seed *** force required to puncture the endosperm cap decreased in two stages during imbibition and showed negative correlation with endo-β-mannanase ***-β-mannanase activity was detected in the endosperm cap prior to radicle *** seeds imbibed in abscisic acid,which did not germinate,weakening of the endosperm and the endo-β-mannanase activity were *** of gibberellin resulted in earlier germination and decreased endosperm resistance sooner than seeds imbibed in abscisic acid and *** The germination of *** seed requires a two-step germination *** this process mechanical forces of the growing embryo pushing against the endosperm cap and enzymic weakening of the endosperm cap are necessary.

关键词： Solanum rostratum radicle endosperm cap endo-β-mannanase puncture force ultrastructures abscisic acid gibberellin

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：