全文获取类型
收费全文 | 69篇 |
免费 | 5篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1972年 | 3篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Keymanthri Moodley Stuart Rennie Frieda Behets Adetayo Emmanuel Obasa Robert Yemesi Laurent Ravez Patrick Kayembe Darius Makindu Alwyn Mwinga Walter Jaoko 《Developing world bioethics》2021,21(1):36-43
The COVID‐19 pandemic has raised important universal public health challenges. Conceiving ethical responses to these challenges is a public health imperative but must take context into account. This is particularly important in sub‐Saharan Africa (SSA). In this paper, we examine how some of the ethical recommendations offered so far in high‐income countries might appear from a SSA perspective. We also reflect on some of the key ethical challenges raised by the COVID‐19 pandemic in low‐income countries suffering from chronic shortages in health care resources, and chronic high morbidity and mortality from non‐COVID‐19 causes. A parallel is drawn between the distribution of severity of COVID‐19 disease and the classic “Fortune at the bottom of the pyramid” model that is relevant in SSA. Focusing allocation of resources during COVID‐19 on the ‘thick’ part of the pyramid in Low‐to‐Middle Income Countries (LMICs) could be ethically justified on utilitarian and social justice grounds, since it prioritizes a large number of persons who have been economically and socially marginalized. During the pandemic, importing allocation frameworks focused on the apex of the pyramid from the global north may therefore not always be appropriate. In a post‐COVID‐19 world, we need to think strategically about how health care systems can be financed and structured to ensure broad access to adequate health care for all who need it. The root problems underlying health inequity, exposed by COVID‐19, must be addressed, not just to prepare for the next pandemic, but to care for people in resource poor settings in non‐pandemic times. 相似文献
6.
Rapposch S Eliskases-Lechner F Ginzinger W 《Applied and environmental microbiology》1999,65(12):5597-5599
The growth of facultatively heterofermentative lactobacilli (FHL) on cell suspensions of the homofermentative Lactobacillus helveticus was investigated. Osmotic lysis of L. helveticus led to a significant increase of ribose. It decreased steadily in parallel with the growth of FHL, strongly suggesting that the bacteria used ribose as a growth substrate. 相似文献
7.
Edmonds A Yotebieng M Lusiama J Matumona Y Kitetele F Napravnik S Cole SR Van Rie A Behets F 《PLoS medicine》2011,8(6):e1001044
Background
The effect of highly active antiretroviral therapy (HAART) on the survival of HIV-infected children has not been well quantified. Because most pediatric HIV occurs in low- and middle-income countries, our objective was to provide a first estimate of this effect among children living in a resource-deprived setting.Methods and Findings
Observational data from HAART-naïve children enrolled into an HIV care and treatment program in Kinshasa, Democratic Republic of the Congo, between December 2004 and May 2010 were analyzed. We used marginal structural models to estimate the effect of HAART on survival while accounting for time-dependent confounders affected by exposure. At the start of follow-up, the median age of the 790 children was 5.9 y, 528 (66.8%) had advanced or severe immunodeficiency, and 405 (51.3%) were in HIV clinical stage 3 or 4. The children were observed for a median of 31.2 mo and contributed a total of 2,089.8 person-years. Eighty children (10.1%) died, 619 (78.4%) initiated HAART, six (0.8%) transferred to a different care provider, and 76 (9.6%) were lost to follow-up. The mortality rate was 3.2 deaths per 100 person-years (95% confidence interval [CI] 2.4–4.2) during receipt of HAART and 6.0 deaths per 100 person-years (95% CI 4.1–8.6) during receipt of primary HIV care only. The mortality hazard ratio comparing HAART with no HAART from a marginal structural model was 0.25 (95% CI 0.06–0.95).Conclusions
HAART reduced the hazard of mortality in HIV-infected children in Kinshasa by 75%, an estimate that is similar in magnitude but with lower precision than the reported effect of HAART on survival among children in the United States. Please see later in the article for the Editors'' Summary 相似文献8.
Differential uptake and translocation of Ca and Sr in organisms have been reported, calling into question the use of Sr to
track Ca cycling in the environment. We investigated the relationship between Ca/Sr ratios in soil extracts of various strengths
(H2O, NH4Cl, and NH4EDTA) and seedlings of sugar maple (Acer saccharum Marsh.) grown from natural regeneration on 37 sites. Our objectives were to determine if Ca/Sr ratios in soil extracts are
correlated with those in sugar maple tissues, and what soil extractant best duplicate plant tissue Ca/Sr ratios. Leaves had
higher Ca/Sr ratios than stems and the extractants did not produce equal Ca/Sr ratios: H2O had the lowest Ca/Sr, and NH4EDTA the highest. The relationships between soil extract Ca/Sr ratios and leaf and stem Ca/Sr ratios were significant and
linear, but the slopes differed among extractants. The lowest slope (0.45) was observed for the water extract/leaves and the
highest (2.15) for the NH4EDTA extract/stem with discrimination factors ranging from 0.22 with NH4EDTA to 1.59 for water. Leaf extracts were more strongly correlated with soil Ca/Sr than stem extracts (R
2 of 0.57–0.7 vs. R
2 of 0.45–0.6, respectively). These findings support the use of Ca/Sr ratios in plants to track their source of soil Ca, but
they highlight the need to calibrate the relationships for the plant tissue and soil extractant used. 相似文献
9.
Rebecca K. Smith Nancy V. Jennings Frieda Tataruch Klaus Hackländer Stephen Harris 《Acta theriologica》2005,50(3):391-404
European haresLepus europaeus Pallas, 1778 have lower population densities and body condition in pastural landscapes than in arable landscapes, but reasons
for this are not understood. The aim of this study was to determine whether forage quality is low in pastural landscapes during
certain seasons. We carried out chemical analysis of the nutritional quality of 5 habitat types to determine whether hares
select high quality habitats, and whether nutritional quality explains seasonal differences in range sizes of hares in pastural
landscapes. Hares did not tend to select habitats of high nutritional quality (protein, fat or energy) over those of lower
quality. Hares did not increase active range size as the overall energy content of forage at the study site decreased; seasonal
differences in active range size were not explained by nutritional quality. Differences may be explained by behavioural changes
related to breeding. Pastural habitat is fairly stable in terms of nutritional quality through the year, and results suggest
that poor forage quality is unlikely to be responsible for the poor body condition of hares in pastural landscapes. Hares
in these landscapes are more likely to be limited by habitat quality in terms of cover than by forage. 相似文献
10.
Yaakov A. Levine Frieda A. Koopman Michael Faltys April Caravaca Alison Bendele Ralph Zitnik Margriet J. Vervoordeldonk Paul Peter Tak 《PloS one》2014,9(8)