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41.
Actinomycetes were isolated from the indoor air of the church of Saint Katherin Monastery during different visiting hours. Fifty air samples collected over one year by using automated air sampler were plated on four different media. The low nutrient-content medium 1/10 SC was significantly effective in recovery of actinomycetes compared to the other formula of rich media. Average counts of bacteria, actinomycetes and fungi were 487, 65 and 90 cfu/m3, respectively. Fifty-six morphologically different actinomycetes isolates were recovered during this study assigned into five different genera, in addition to three unidentified isolates. Tentative identification of the isolates indicated predominance of genus Streptomyces, representing 59% of the isolates. Isolates were screened for resistance to 11 antibiotics, antimicrobial activities towards seven microbial strains, Growth on 12 different carbon source, acid production and pigmentation. About 77% of actinomycete isolates were resistant to the antibiotics with different resistance patterns. 12.5% of the airborne actinomycetes exhibited antinmicrobial activities. The isolates showed wide variation in carbon source usage. Forty percent of the isolates were able to utilize all tested carbon sources while 80% were acid producers. Melanin production was produced by 34% of the isolates. While 45% of the isolates were able to produce other diffusible pigments, the majority of the pigments were brown in color however; yellow, orange and green pigments were produced by a number of isolates. The impact of these activities on the historical objects of the church and the tourist’s health is discussed.  相似文献   
42.
新疆北部森林生态系统地衣植物生活型分析   总被引:2,自引:0,他引:2  
Life forms of lichen of forest ecosystem in Northern Xinjiang were researched in the Kanas National Natural Reservation Area.They have been grouped into 6 types:Epipetria,Soil-epipetria,Epiphytia arboricosa,Epiphytia moss,Epiphytis grass and Dry-radicantia,in which the species of Epiphytia arboricosa account for 36.89% of the total species in this area,the species of Epipetria for 22.33% and Epiphytia grass the least.The results show that life forms of lichem at the srea in Northem Xinjiang are relatively rich,which indicates the biodiversity characteristics of lichen.  相似文献   
43.
Actinomycetes inhabiting granitic rocks at St. Katherine, Egypt were investigated for their bioweathering potential. Actinomycete counts ranged between 174 and 360 colony forming units per gram. Counts were positively correlated to rock porosity (r = 0.65) and negatively correlated to rock salinity (r = −0.56). Sixty-six actinomycete isolates originating from rocks could be assigned into eight genera, with a high frequency of Nocardioides and Streptomyces. Organic acids were produced by 97% of the isolates. Strains belonging to Actinopolyspora, Actinomadura, Kitasatospora, Nocardioides, and Kibdelosporangium showed the highest acid production indices. Representatives from all eight genera could precipitate metals Cu, Fe, Zn, Cd, and Ag up to concentrations of 2.5 mM each. An actinomycete consortium of two Nocardioides strains and one Kibdelosporangium strain was studied for its potential to cause rock weathering in batch experiments. Results indicated a high ability of the consortium to leach the metals Cu, Zn, and Fe up to 2.6-, 2.1-, and 1.3-fold, respectively, compared to the control after 4 weeks. The pH significantly decreased after 1 week, which was parallel to an increased release of phosphate and sulfate reaching a 2.2- and 2.5-fold increase, respectively, compared to control. Highly significant weight loss (p = 0.005) was achieved by the consortium, indicating a potential multiple role of actinomycetes in weathering by acid production, metal leaching, and solubilization of phosphate and sulfate. This study emphasizes the diverse and unique abilities of actinomycetes inhabiting rock surfaces which could be of potential biotechnological applications, such as in the bioremediation of metal-contaminated environments and metal biorecovery.  相似文献   
44.
我国螨类研究的最新进展   总被引:9,自引:0,他引:9  
螨类是一种对人类危害极其严重的小型节肢动物,不论从人的健康方面还是农牧林生产方面来说都需要防治及至根除。主要钛螨类的形态特征、生活史、生态类群、对人类的危害及其防治等5个方面简述了我国螨类研究的最新研究进展概况。  相似文献   
45.
报道新疆拟橙衣属地衣的6个分类单位。其中南方拟橙衣Fulgensia australis,荒漠拟橙衣F.desertorum和苔生拟橙衣F.schistidii为中国新记录种。在形态学、解剖学、化学及生态学方面对它们进行了简短的论述。此外,还提供了形态特征和内部解剖特征照片以及新疆种类的分种检索表。研究所用的标本采自托木尔峰、铁力买提达坂、阿尔金山和准葛尔盆地等,保存于新疆大学生命科学与技术学院地衣标本室。  相似文献   
46.
47.
A significant portion of organic phosphorus comprises of phytates which are not available to wheat for uptake. Hence for enabling wheat to utilize organic phosphorus in form of phytate, transgenic wheat expressing phytase from Aspergillus japonicus under barley root-specific promoter was developed. Transgenic events were initially screened via selection media containing BASTA, followed by PCR and BASTA leaf paint assay after hardening. Out of 138 successfully regenerated To events, only 12 had complete constructs and thus further analyzed. Positive T1 transgenic plants, grown in sand, exhibited 0.08–1.77, 0.02–0.67 and 0.44–2.14 fold increase in phytase activity in root extracts, intact roots and external root solution, respectively, after 4 weeks of phosphorus stress. Based on these results, T2 generation of four best transgenic events was further analyzed which showed up to 1.32, 56.89, and 15.40 fold increase in phytase activity in root extracts, intact roots and external root solution, respectively, while in case of real-time PCR, maximum fold increase of 19.8 in gene expression was observed. Transgenic lines showed 0.01–1.18 fold increase in phosphorus efficiency along with higher phosphorus content when supplied phytate or inorganic phosphorus than control plants. Thus, this transgenic wheat may aid in reducing fertilizer utilization and enhancing wheat yield.  相似文献   
48.

Background

Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended for malaria prevention in HIV-negative pregnant women, but it is contraindicated in HIV-infected women taking daily cotrimoxazole prophylaxis (CTXp) because of potential added risk of adverse effects associated with taking two antifolate drugs simultaneously. We studied the safety and efficacy of mefloquine (MQ) in women receiving CTXp and long-lasting insecticide treated nets (LLITNs).

Methods and Findings

A total of 1,071 HIV-infected women from Kenya, Mozambique, and Tanzania were randomized to receive either three doses of IPTp-MQ (15 mg/kg) or placebo given at least one month apart; all received CTXp and a LLITN. IPTp-MQ was associated with reduced rates of maternal parasitemia (risk ratio [RR], 0.47 [95% CI 0.27–0.82]; p = 0.008), placental malaria (RR, 0.52 [95% CI 0.29–0.90]; p = 0.021), and reduced incidence of non-obstetric hospital admissions (RR, 0.59 [95% CI 0.37–0.95]; p = 0.031) in the intention to treat (ITT) analysis. There were no differences in the prevalence of adverse pregnancy outcomes between groups. Drug tolerability was poorer in the MQ group compared to the control group (29.6% referred dizziness and 23.9% vomiting after the first IPTp-MQ administration). HIV viral load at delivery was higher in the MQ group compared to the control group (p = 0.048) in the ATP analysis. The frequency of perinatal mother to child transmission of HIV was increased in women who received MQ (RR, 1.95 [95% CI 1.14–3.33]; p = 0.015). The main limitation of the latter finding relates to the exploratory nature of this part of the analysis.

Conclusions

An effective antimalarial added to CTXp and LLITNs in HIV-infected pregnant women can improve malaria prevention, as well as maternal health through reduction in hospital admissions. However, MQ was not well tolerated, limiting its potential for IPTp and indicating the need to find alternatives with better tolerability to reduce malaria in this particularly vulnerable group. MQ was associated with an increased risk of mother to child transmission of HIV, which warrants a better understanding of the pharmacological interactions between antimalarials and antiretroviral drugs.

Trial registration

ClinicalTrials.gov NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001813440 Please see later in the article for the Editors'' Summary  相似文献   
49.
A natural source of medicine, Enicosanthellum pulchrum is a tropical plant which belongs to the family Annonaceae. In this study, methanol extract from the leaves and stems of this species was evaluated for its gastroprotective potential against mucosal lesions induced by ethanol in rats. Seven groups of rats were assigned, groups 1 and 2 were given Tween 20 (10% v/v) orally. Group 3 was administered omeprazole 20 mg/kg (10% Tween 20) whilst the remaining groups received the leaf and stem extracts at doses of 150 and 300 mg/kg, respectively. After an additional hour, the rats in groups 2–7 received ethanol (95% v/v; 8 mL/kg) orally while group 1 received Tween 20 (10% v/v) instead. Rats were sacrificed after 1 h and their stomachs subjected to further studies. Macroscopically and histologically, group 2 rats showed extremely severe disruption of the gastric mucosa compared to rats pre-treated with the E. pulchrum extracts based on the ulcer index, where remarkable protection was noticed. Meanwhile, a significant percentage of inhibition was shown with the stem extract at 62% (150 mg/kg) and 65% (300 mg/kg), whilst the percentage with the leaf extract at doses of 150 and 300 mg/kg was 63% and 75%, respectively. An increase in mucus content, nitric oxide, glutathione, prostaglandin E2, superoxide dismutase, protein and catalase, and a decrease in malondialdehyde level compared to group 2 were also obtained. Furthermore, immunohistochemical staining of groups 4–7 exhibited down-regulation of Bax and up-regulation of Hsp70 proteins. The methanol extract from the leaves and the stems showed notable gastroprotective potential against ethanol.  相似文献   
50.
新疆博格达山岩面生地衣群落结构特征   总被引:1,自引:1,他引:0  
根据对新疆博格达山岩面生地衣群落20个样点(20m×20m)调查的数据,以各地衣种的盖度为指标结合双向指示种分析方法(TWINSPAN)和除趋势对应分析法(DCA)对博格达山岩面生地衣群落进行数量分类并分析了群落结构特征及其多样性和相似性。采用典范对应分析法(CCA)对各群落的物种分布格局与环境因子的关系进行研究。结果表明,TWINSPAN分析和DCA排序将分布在博格达山的37种岩面生地衣分为以下5个群丛。群丛1:斑纹网衣(Lecidea tessellate Florke)+粉芽盾衣(Peltula euploca(Ach.)Poelt)+杜瑞氏黄梅(Xanthoparmelia durietzii Hale)群丛,有25个种,总覆盖度为30.145%,多样性为4.025;群丛2:袋衣(Hypogymnia physodes(L.)Nyl.)+白边平茶渍(Aspicilia sublaqueata(H.Magn.)J.C.Wei)+砖孢胶衣(Collema subconveniens Nyl.)群丛,有17个种,地衣总盖度为15.885%,多样性为3.196;群丛3:聚茶渍(Lecanora accumulate H.Magn.)+丽石黄衣(Xanthoria elegans(Link)Th.Fr.)+亚洲平茶渍(Aspicilia asiatica(H.Magn.)Yoshim.)群丛,有30个种,地衣总盖度为37.87%,多样性为4.357;群丛4:中华石果衣(Endocarpon sinense H.Magn.)+伴藓大孢蜈蚣衣(Physconia muscigena(Ach.)Poelt.)+垫脐鳞衣(Rhizoplaca melanophthalma(DC.)LeuckertPoelt)群丛,有24个种,地衣总盖度为30.458%,多样性为3.912;群丛5:石胶衣(Collema flaccidum(Ach.)Ach.)+短绒皮果衣(Dermatocarpon vellereum Zschacke)+绿黑地图衣(Rhizocarpon viridiatrum(Wulfen)Korber.)群丛,有18个种,地衣总盖度为19.331%,多样性为3.515。CCA排序结果反映,该地区岩面生地衣的分布与海拔高度、光照强度、岩石pH和人为干扰有关,其中影响最大的因素是海拔高度,其次为光照强度和干扰。坡向和岩石大小对地衣种类分布的影响不显著。  相似文献   
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