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   118篇
  免费   2篇
  国内免费   1篇
  2021年   1篇
  2020年   3篇
  2019年   3篇
  2018年   3篇
  2017年   5篇
  2016年   4篇
  2015年   6篇
  2014年   7篇
  2013年   6篇
  2012年   3篇
  2011年   13篇
  2010年   2篇
  2009年   4篇
  2008年   6篇
  2007年   2篇
  2005年   5篇
  2004年   4篇
  2002年   2篇
  2001年   6篇
  2000年   3篇
  1999年   3篇
  1998年   5篇
  1996年   2篇
  1995年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1986年   4篇
  1985年   3篇
  1984年   1篇
  1982年   2篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
  1968年   1篇
排序方式: 共有121条查询结果,搜索用时 15 毫秒
1.
Adamczyk-Winiarska  Z.  Król  M.  Kobus  J. 《Plant and Soil》1975,43(1-3):95-100
Plant and Soil - Brown soil formed from loamy clay was examined for its ability to produce sulphate from added elemental suphur. At higher rates of sulphur applications the pH of a slightly acid...  相似文献   
2.
3.
4.
Background and objectives The purpose of this paper is to describe the use of resident performance on an observed structured clinical examination (OSCE) as a tool to refine a mood disorders curriculum, and to disseminate a mood disorders OSCE for use in other residency settings.Methods A depression-focused OSCE and a direct observation evaluation tool were developed and implemented. A total of 24 first-year family medicine residents (PGY1) participated in the OSCE, and their performance was used to direct changes in a mood disorders curriculum.Results Residents performed well on general interview behaviours, and 67% were able to uncover depression in a patient presenting with headaches. Less than 50% of the residents asked about suicidal ideation and recreational drug use. Curriculum was added that addressed the latter deficiencies.Conclusions Tracking of resident performance on specific behaviours during OSCE sessions can be used for curriculum evaluation purposes. The mood disorders curriculum in additional family medicine residency programmes can now be evaluated using our depression-focused OSCE and Clinical Performance Checklist.  相似文献   
5.

Background

Peripheral artery disease (PAD) is an important global health problem and contributes to notable proportion of morbidity and mortality. This particular manifestation of systemic atherosclerosis is largely under diagnosed and undertreated. For sustainable preventive strategies in a country, it is mandatory to identify country-specific risk factors. We intended to assess the risk factors of PAD among adults aged 40–74 years.

Methods

This case control study was conducted in 2012–2013 in Sri Lanka. Seventy-nine cases and 158 controls in the age group of 40–74 years were selected for the study in order to have case to control ratio 1:2. The criterion for selecting cases and control was based on Ankle brachial pressure index (ABPI). Cases were selected from those who had ABPI 0.85 or less (ABPI ≤0.85) in either lower limb. Controls were selected from those ABPI score between 1.18 and 1.28 in both lower limbs. Only newly identified individuals with PAD were selected as cases. Controls were selected from the same geographical location and within the 5 year age group as cases.

Results

The history of diabetes mellitus more than 10 years (OR 5.8, 95% CI 2.2–14.2), history of dyslipidemia for more than 10 years (OR 4.9, 95% CI 2.1–16.2), history of hypertension for more than 10 years (OR 3.8, 95% CI 1.8–12.7) and smoking (OR 2.9, 95% CI 1.2–6.9), elevated HsCRP (OR 3.7, 95% CI 1.2–12.0) and hyperhomocysteinemia (OR 3.0, 95% CI 1.1–8.1) were revealed as country specific significant risk factor of PAD.

Conclusions

Diabetes mellitus, hypertension, dyslipidemia, smoking as well as elevated homocysteine and HsCRP found as risk factors of PAD. Longer the duration or higher level exposure to these risk factors has increased the risk of PAD. These findings emphasis the need for routine screening of PAD among patients with the identified risk factors.
  相似文献   
6.
Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.  相似文献   
7.
Mycotoxins are secondary metabolites produced by many filamentous fungi, such as Fusarium, and are widespread in nature and can adversely affect almost all organisms. Mycotoxins can be formed in very different conditions such as when plants are growing or in crops that are stored in improper conditions. One of the methods to prevent the formation of mycotoxins in powdered feed is using varieties of appropriate quality and proper mineral fertilization, primarily nitrogen. In this study, the concentration of ergosterol and mycotoxins in the kernels of two maize cultivars from different maturity groups in Poland during the harvest of 2011 and 2012 was investigated using HPLC methods. We aimed to analyse the concentration of ergosterol as a fungal biomass indicator and mycotoxins from two maize cultivars under six different forms of nitrogen fertilizers. The “stay‐green” hybrid ES Paroli was characterized by a significantly lower ergosterol and the ability to accumulate the mycotoxins, compared to the classic cultivar ES Palazzo. The varieties of maize that remain green for a longer time period, the so‐called stay‐green type, are characterized by a different coefficient of nitrogen remobilization compared to the classic hybrids. Their dynamics of growth and accumulation of nutrients indicates a nitrogen fertilization system, indicating that slow‐release fertilizers are potentially more adapted to the cycles of maize vegetation. Hence, compared to the classic variant, the “stay‐green” variety uses nitrogen more effectively from mineral fertilizers. Such hybrids are healthier and remain in good condition for a longer time; therefore, they are characterized by a lower pathogen pressure. Thus, the cultivation of such varieties can be considered as one of the elements of integrated maize production. We observed identical reactions of the studied experimental factors for both vegetation seasons, which indicates the lack of environmental impact on the functioning and interaction of experimental factors.  相似文献   
8.
Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development. The major features of the disease include midface hypoplasia, micrognathia, microtia, conductive hearing loss and cleft palate. Current procedures of surgical treatment of TCS are discussed and novel findings concerning the genetic background of TCS are described. The TCS locus has been mapped to chromosome 5q31.3-32. The TCOF1 gene contains 26 exons and encodes a 1411 amino acid protein named treacle. In the TCOF1 gene 51 mutations have been identified. Most of these mutations are insertions or deletions, which result in an introduction of a premature termination codon into the reading frame. Mutational spectra support the hypothesis that TCS results from haploinsufficiency of treacle.  相似文献   
9.

Background

Women have better patient outcomes in HIV care and treatment than men in sub-Saharan Africa. We assessed—at the population level—whether and to what extent mass HIV treatment is associated with changes in sex disparities in adult life expectancy, a summary metric of survival capturing mortality across the full cascade of HIV care. We also determined sex-specific trends in HIV mortality and the distribution of HIV-related deaths in men and women prior to and at each stage of the clinical cascade.

Methods and Findings

Data were collected on all deaths occurring from 2001 to 2011 in a large population-based surveillance cohort (52,964 women and 45,688 men, ages 15 y and older) in rural KwaZulu-Natal, South Africa. Cause of death was ascertained by verbal autopsy (93% response rate). Demographic data were linked at the individual level to clinical records from the public sector HIV treatment and care program that serves the region. Annual rates of HIV-related mortality were assessed for men and women separately, and female-to-male rate ratios were estimated in exponential hazard models. Sex-specific trends in adult life expectancy and HIV-cause-deleted adult life expectancy were calculated. The proportions of HIV deaths that accrued to men and women at different stages in the HIV cascade of care were estimated annually.Following the beginning of HIV treatment scale-up in 2004, HIV mortality declined among both men and women. Female adult life expectancy increased from 51.3 y (95% CI 49.7, 52.8) in 2003 to 64.5 y (95% CI 62.7, 66.4) in 2011, a gain of 13.2 y. Male adult life expectancy increased from 46.9 y (95% CI 45.6, 48.2) in 2003 to 55.9 y (95% CI 54.3, 57.5) in 2011, a gain of 9.0 y. The gap between female and male adult life expectancy doubled, from 4.4 y in 2003 to 8.6 y in 2011, a difference of 4.3 y (95% CI 0.9, 7.6). For women, HIV mortality declined from 1.60 deaths per 100 person-years (95% CI 1.46, 1.75) in 2003 to 0.56 per 100 person-years (95% CI 0.48, 0.65) in 2011. For men, HIV-related mortality declined from 1.71 per 100 person-years (95% CI 1.55, 1.88) to 0.76 per 100 person-years (95% CI 0.67, 0.87) in the same period. The female-to-male rate ratio for HIV mortality declined from 0.93 (95% CI 0.82–1.07) in 2003 to 0.73 (95% CI 0.60–0.89) in 2011, a statistically significant decline (p = 0.046). In 2011, 57% and 41% of HIV-related deaths occurred among men and women, respectively, who had never sought care for HIV in spite of the widespread availability of free HIV treatment. The results presented here come from a poor rural setting in southern Africa with high HIV prevalence and high HIV treatment coverage; broader generalizability is unknown. Additionally, factors other than HIV treatment scale-up may have influenced population mortality trends.

Conclusions

Mass HIV treatment has been accompanied by faster declines in HIV mortality among women than men and a growing female–male disparity in adult life expectancy at the population level. In 2011, over half of male HIV deaths occurred in men who had never sought clinical HIV care. Interventions to increase HIV testing and linkage to care among men are urgently needed.  相似文献   
10.

Background

A recent epidemiological study demonstrated a reduced risk of lung cancer mortality in breast cancer patients using antiestrogens. These and other data implicate a role for estrogens in lung cancer, particularly nonsmall cell lung cancer (NSCLC). Approximately 61% of human NSCLC tumors express nuclear estrogen receptor β (ERβ); however, the role of ERβ and estrogens in NSCLC is likely to be multifactorial. Here we tested the hypothesis that proteins interacting with ERβ in human lung adenocarcinoma cells that respond proliferatively to estradiol (E2) are distinct from those in non-E2-responsive cells.

Methods

FLAG affinity purification of FLAG-ERβ-interacting proteins was used to isolate ERβ-interacting proteins in whole cell extracts from E2 proliferative H1793 and non-E2-proliferative A549 lung adenocarcinoma cell lines. Following trypsin digestion, proteins were identified using liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS). Proteomic data were analyzed using Ingenuity Pathway Analysis. Select results were confirmed by coimmunoprecipitation.

Results

LC-MS/MS identified 27 non-redundant ERβ-interacting proteins. ERβ-interacting proteins included hsp70, hsp60, vimentin, histones and calmodulin. Ingenuity Pathway Analysis of the ERβ-interacting proteins revealed differences in molecular and functional networks between H1793 and A549 lung adenocarcinoma cells. Coimmunoprecipitation experiments in these and other lung adenocarcinoma cells confirmed that ERβ and EGFR interact in a gender-dependent manner and in response to E2 or EGF. BRCA1 interacted with ERβ in A549 cell lines and in human lung adenocarcinoma tumors, but not normal lung tissue.

Conclusion

Our results identify specific differences in ERβ-interacting proteins in lung adenocarcinoma cells corresponding to ligand-dependent differences in estrogenic responses.
  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