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排序方式: 共有668条查询结果,搜索用时 9 毫秒
101.
The global impact of the converging dual epidemics of tuberculosis (TB) and human immunodeficiency virus (HIV) is one of the
major public health challenges of our time. The World Health Organization (WHO) reports 9.2 million new cases of TB in 2006
of whom 7.7% were HIV-infected. Tuberculosis is the most common opportunistic infection in HIV-infected patients as well as
the leading cause of death. Further, there has been an increase in rates of drug resistant tuberculosis, including multi-drug
(MDRTB) and extensively drug resistant TB (XDRTB), which are difficult to treat and contribute to increased mortality. The
diagnosis of TB is based on sputum smear microscopy, a 100-year old technique and chest radiography, which has problems of
specificity. Extra-pulmonary, disseminated and sputum smear negative manifestations are more common in patients with advanced
immunosuppression. Newer diagnostic tests are urgently required that are not only sensitive and specific but easy to use in
remote and resource-poor settings. Treatment of HIV-TB co-infection is complex and associated with high pill burden, overlapping
drug toxicities, risk of immune reconstitution inflammatory syndrome (IRIS) and challenges related to adherence. From a programmatic
point of view, screening of all HIV-infected persons for tuberculosis and vice-versa will help identify co-infected patients
who require treatment for both infections. This requires good coordination and communication between the TB and AIDS control
programs, in India. 相似文献
102.
Ryan L. Fimmen Daniel deB. RichterJr. Dharni Vasudevan Mark A. Williams Larry T. West 《Biogeochemistry》2008,87(2):127-141
Field-scale observations of two upland soils derived from contrasting granite and basalt bedrocks are presented to hypothesize
that redox activity of rhizospheres exerts substantial effects on mineral dissolution and colloidal translocation in many
upland soils. Rhizospheres are redox-active microsites and in the absence of O2, oxidation of rhizodeposits can be coupled by reduction of redox-active species such as Fe, a biogenic reduction that leads
to Fe translocation and oxidation, accompanied by substantial proton flux. Not only do rhizogenic Fe–C redox cycles demonstrate
a process by which the rhizosphere affects an environment well outside the near-root zone, but these redox processes are also
hypothesized to be potent weathering systems, such that rhizogenic redox-reactions complement acid- and ligand-promoted reactions
as major biogeochemical processes that control crustal weathering. The potential significance of Fe–C redox cycling is underscored
by the deep and extensive rooting and mottling of upland subsoils across a wide range of plant communities, lithologies, and
soil-moisture and temperature regimes. 相似文献
103.
104.
Makoedov A. N. Korotaev Yu. A. Korotaeva O. B. 《Russian Journal of Marine Biology》2001,27(4):238-244
The temporal heterogeneity of chum salmon stock of the Anadyr Bay region was investigated on the basis of a set of discrete external morphological features and fluctuating asymmetry level of some meristic structures. Differentiation of Anadyr Bay chum salmon during the spawning run was found to be associated with the abundance level of spawning stock in a particular year. Sharply pronounced temporal heterogeneity, based on the investigated characteristics, in the area near the river mouth can be considered as an indicator of the subsequent deficiency of spawners on the spawning grounds of rivers in the Anadyr Bay region. 相似文献
105.
浙江淡水维管束植物的区系特点与地理分布 总被引:17,自引:1,他引:16
根据15年的调查结果,对浙江省水生维管束植物的区系与地理分布特点进行了研究。已知浙江有水生维管束植物150种,隶属于78属,42科。将78属归纳为11个分布区类型,以世界分布类型所占比例最高,热带分布属总数多于温带分布属,泛热带分布和北温带分布比例非常高。将150种植物归纳为13个分布区类型,温带分布远多于热带分布,以东亚分布类型最为突出,体现了中国-日本植物区系的明显特征,探讨了浙江水生植物的水平地带性和垂直地带性分布规律,其分布不仅与气候带有关,更与水生的生境的分布格局有关。最后,报浙江水生植物濒危种的受威胁状况。 相似文献
106.
107.
Kurdistan province of Iran is one of the main places for producing chickpea, and there is no published research on root-nodulating bacteria of this crop. Plant samples were collected and a total of 73 Rhizobium strains were isolated from root nodules. Nodulation test was done on chickpea plants. Phenotypic characteristics of the 16 representative strains were determined based on the standard bacteriological methods. Total soluble cell protein patterns by electrophoresis approach (SDS-PAGE) showed heterogeneity among the tested rhizobia strains. Based on the phenotypic features, Rhizobium strains of three groups belong to different species of the genus Mesorhizobioum including M. ciceri and M. mediterraneum and Mesorhizobium sp. The PCR technique was employed for amplification of 16S rDNA and atpD genes. For further characterisation, amplified fragment of 16S rDNA gene from a representative strain (AK21) using primers 41F and 1488R was subjected to sequencing. Sequences were aligned by BLAST software at NCBI GenBank and results showed 99% similarity with M. mediterraneum strain BKBCF3q. 相似文献
108.
Vinod K. Bisht Chandra P. Kuniyal Arvind K. Bhandari Bhagwati P. Nautiyal P. Prasad 《Physiology and Molecular Biology of Plants》2014,20(3):399-403
Observations on phenology of some representative trees, shrubs, under-shrubs and herbs in a subalpine forest of Uttarakhand, western Himalaya were recorded. With the commencement of favorable growth season in April, occurrence of leaf fall was indicatory growth phenomenon in Quercus semecarpifolia, Q. floribunda and Abies spectabilis. However, active vegetative growth in herbaceous species starts onward April and fruit maturation and seed dehiscence are completed from mid of September to October. In general, vegetative growth and reproductive stages in majority of the studied species seems to be dependent on adequate moisture content and also flowering and fruiting in subalpine plants correlate ambient temperature. 相似文献
109.
报道了采自安徽省金寨县天堂寨镇的中国对囊蕨属一新记录植物——光叶对囊蕨Deparia otomasui(Sa.Kurata)Seriz.。光叶对囊蕨之前仅发现于日本,其根状茎细长横走,叶片一回羽状,羽片羽状分裂,叶为纸质,有光泽,近光滑无毛,是对囊蕨属中形态较为独特的一个物种。该文对光叶对囊蕨的形态特征进行了详细描述,并提供了生态照片和线描图,编制了安徽省对囊蕨属部分物种的检索表,同时对该种的保护等级进行了评估。凭证标本保存于上海辰山植物标本馆(CSH)。 相似文献
110.
C. Kahindo M.A. El-Yacoubi S. Garcia-Salicetti V. Cristancho-Lacroix H. Kerhervé A.-S. Rigaud 《IRBM》2018,39(6):421-429