首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   122篇
  免费   14篇
  136篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   5篇
  2016年   7篇
  2015年   11篇
  2014年   10篇
  2013年   6篇
  2012年   7篇
  2011年   3篇
  2010年   6篇
  2009年   3篇
  2007年   2篇
  2006年   3篇
  2005年   7篇
  2004年   1篇
  2002年   1篇
  2001年   4篇
  2000年   6篇
  1999年   5篇
  1998年   6篇
  1997年   4篇
  1996年   6篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1978年   2篇
  1977年   3篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
  1969年   1篇
  1965年   1篇
  1934年   1篇
排序方式: 共有136条查询结果,搜索用时 9 毫秒
1.
2.

Background

In the past decade there has been increasing visibility of malaria control efforts at the national and international levels. The factors that have enhanced this scenario are the availability of proven interventions such as artemisinin-based combination therapy, the wide scale use of insecticide-treated nets (ITNs) and a renewed emphasis in indoor residual house-spraying. Concurrently, there has been a window of opportunity of financial commitments from organizations such as the Global Fund for HIV/AIDS, Tuberculosis and Malaria (GFATM), the President's Malaria Initiative and the World Bank Booster programme.

Methods

The case study uses the health policy analysis framework to analyse the implementation of a public-private partnership approach embarked upon by the government of Tanzania in malaria control – 'The Tanzania National Voucher Scheme'- and in this synthesis, emphasis is on the challenges faced by the scheme during the pre-implementation (2001 – 2004) and implementation phases (2004 – 2005). Qualitative research tools used include: document review, interview with key informants, stakeholder's analysis, force-field analysis, time line of events, policy characteristic analysis and focus group discussions. The study is also complemented by a cross-sectional survey, which was conducted at the Rufiji Health Demographic Surveillance Site, where a cohort of women of child-bearing age were followed up regarding access and use of ITNs.

Results

The major challenges observed include: the re-introduction of taxes on mosquito nets and related products, procurement and tendering procedures in the implementation of the GFATM, and organizational arrangements and free delivery of mosquito nets through a Presidential initiative.

Conclusion

The lessons gleaned from this synthesis include: (a) the consistency of the stakeholders with a common vision, was an important strength in overcoming obstacles, (b) senior politicians often steered the policy agenda when the policy in question was a 'crisis event', the stakes and the visibility were high, (c) national stakeholders in policy making have an advantage in strengthening alliances with international organizations, where the latter can become extremely influential in solving bottlenecks as the need arises, and (d) conflict can be turned into an opportunity, for example the Presidential initiative has inadvertently provided Tanzania with important lessons in the organization of 'catch-up' campaigns.  相似文献   
3.
The Loridae are an arboreal family of small primates that are specialized for slow and quiet climbing. This paper examines the relationship between lorid locomotory behaviour and postcranial skeletal morphology. Lorid humeral and femoral diaphyseal geometric cross-sectional properties, articular surface areas, and lengths are compared to those properties in other small primates with less specialized locomotory behaviour. The comparative sample includes both closely related prosimians and more distantly related platyrrhines.
Results indicate that lorids have greater humeral and femoral diaphyseal rigidity than other quadrupedal primates of similar body size, suggesting that lorid limbs are subjected to greater forces. Lorids also have relatively larger humeral and femoral articulations, corresponding to field and laboratory observations which indicate that lorid joints are highly mobilc. In addition, lorids have long humeri relative to femoral length, and compared to humeral length in less specialized prosimians of similar body mass. Long humeral length relative to femoral length is interpreted as a climbing adaptation because similar limb proportions are also seen in many non-primate climbers. Altogether, humeral and femoral diaphyseal cross-sectional properties, articular surface areas, and lengths comprise a suite of characters which have potential for identifying climbing specialists in the fossil record.  相似文献   
4.
We report on a novel transgenic mouse model expressing human full‐length Tau with the Tau mutation A152T (hTauAT), a risk factor for FTD‐spectrum disorders including PSP and CBD. Brain neurons reveal pathological Tau conformation, hyperphosphorylation, mis‐sorting, aggregation, neuronal degeneration, and progressive loss, most prominently in area CA3 of the hippocampus. The mossy fiber pathway shows enhanced basal synaptic transmission without changes in short‐ or long‐term plasticity. In organotypic hippocampal slices, extracellular glutamate increases early above control levels, followed by a rise in neurotoxicity. These changes are normalized by inhibiting neurotransmitter release or by blocking voltage‐gated sodium channels. CA3 neurons show elevated intracellular calcium during rest and after activity induction which is sensitive to NR2B antagonizing drugs, demonstrating a pivotal role of extrasynaptic NMDA receptors. Slices show pronounced epileptiform activity and axonal sprouting of mossy fibers. Excitotoxic neuronal death is ameliorated by ceftriaxone, which stimulates astrocytic glutamate uptake via the transporter EAAT2/GLT1. In summary, hTauAT causes excitotoxicity mediated by NR2B‐containing NMDA receptors due to enhanced extracellular glutamate.  相似文献   
5.
6.
7.
8.
9.
10.
The control of Spodoptera frugiperda is based on synthetic insecticides, so some alternatives are the use of entomopathogenic fungi (EF) and neem extract. The objective of the study was to evaluate in vitro effectiveness of native EF and neem extracts on S. frugiperda larvae. Six EF were identified by DNA sequencing of ITS regions from three EF (Fusarium solani, Metarrhizium robertsii, Nigrospora spherica and Penicillium citrinum). They were evaluated in concentrations of 1 × 10⁸ spores/ mL. In addition, a second bioassay was carried out evaluating only F. solani, M. robertsii and N. sphaerica and the addition of vegetable oil. On the other hand, extraction of secondary metabolites from neem seed (Azadirachta indica) was carried out by performing, mass (g) and solvent volume (mL ethanol and water) combinations, which were subjected to microwaves and ultrasound. Subsequently, these extracts were evaluated in concentrations of 3%, 4% and 5%. A survival analysis was performed for each of the bioassays. With respect to the results of the first bioassay, F. solani obtained a probability of survival of 0.476 on the seventh day, while in the second bioassay, M. robertsii obtained 0.488 survival probability. This suggests that the expected percentage of larvae that stay alive on the sixth day is 48.8%. However, in the evaluation of the neem extract the combination 1:12/70% to 4% caused 84% mortality of larvae. The use of native HE and neem extracts has potential for the control of S. frugiperda.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号