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   297篇
  免费   36篇
  333篇
  2023年   3篇
  2022年   6篇
  2021年   9篇
  2020年   5篇
  2019年   9篇
  2018年   8篇
  2017年   6篇
  2016年   11篇
  2015年   32篇
  2014年   30篇
  2013年   15篇
  2012年   42篇
  2011年   18篇
  2010年   14篇
  2009年   9篇
  2008年   24篇
  2007年   21篇
  2006年   24篇
  2005年   11篇
  2004年   7篇
  2003年   15篇
  2002年   6篇
  2001年   1篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1992年   1篇
  1981年   1篇
  1970年   1篇
排序方式: 共有333条查询结果,搜索用时 0 毫秒
141.
This article explores how suspicions of kala jaddu (black magic) restructure local and transnational family networks among Pakistani immigrants in Denmark. The notions of 'working' and 'stealing' are analysed as two idioms that sum up what it means to 'be' and 'do' family. 'Working' refers to the expectations and moral obligations of the traditional patrilocal household, 'stealing' to the appropriation of emotional and material means through the use of kala jaddu . It is argued that black magic is employed to contest authority and reorganize transnational migrant networks, and that growing anxieties about kala jaddu are due to intergenerational changes within Pakistani families, as well as to the changing political climate towards immigrants in Danish society.  

Résumé


L'auteur explore la manière dont les soupçons de magie noire ( kala jaddu ) restructurent les réseaux familiaux locaux et transnationaux des immigrés pakistanais au Danemark. Les notions de « travail >> et de « vol >> sont analysées comme deux idiomes qui résument ce que signifie «être >> et « faire >> une famille. « Travail >> renvoie aux attentes et aux obligations morales de la maisonnée patrilocale traditionnelle, « vol >>à l'appropriation de moyens émotionnels et matériels par le recours à la kala jaddu . L'auteur avance que la magie noire est employée pour contester l'autorité et réorganiser les réseaux de migrants transnationaux et que l'inquiétude grandissante à son sujet résulte des changements intergénérationnels dans les familles pakistanaises autant que du changement de climat politique vis-à-vis des immigrés dans la société danoise.  相似文献   
142.
The high arctic is undergoing a faster change in climate than most other regions of the planet, with already observed ecological consequences. Combined with the characteristics of high-arctic ecosystems, such as low species redundancy, high seasonality and weather extremes, shifts in individual species performance and phenology may lead to altered interaction dynamics through trophic mismatch and cascades. An ecosystem approach is therefore desirable in the attempt to understand the multidimensional impacts of climate. Here, we present ecosystem-wide trend analyses of a long-term dataset on terrestrial and limnic biota with focus on the distribution of observed trends and associated variation across the ecosystem. We used 114 time series drawn from 11 abiotic variables, 19 terrestrial and 7 limnic biotic species/taxa and compared temporal trends, changes and abrupt shifts in the variation within and across the two biota. A total of 36 % of the time series analysed showed a significant trend during the study period with a higher frequency of trends occurring within performance variables. Overall, the changes tended to be negative, indicating advances in phenology but reduced species performance. General system variance was also higher in the limnic biota than in the terrestrial biota, both exhibiting increasing variance up through the trophic system. Overall, our results suggest that multiple biotic responses to the climatic changes in this high-arctic ecosystem are not synchronised across trophic levels and may differ qualitatively and quantitatively between terrestrial and limnic biota.  相似文献   
143.
Carbon Footprint   总被引:1,自引:0,他引:1  
  相似文献   
144.
145.
As mass‐produced, low‐cost organic electronics enter our everyday lives, so does the waste from them. The challenges associated with end‐of‐life management must be addressed by careful design and carbon‐based electrodes are central to these developments. Here, the reproducible production of vacuum‐, indium tin oxide (ITO)‐, and silver‐free solar cells in a fully packaged form using only roll‐to‐roll processing is reported. Replacing silver with carbon as electrode material significantly lowers the manufacturing cost and makes the organic photovoltaic (OPV) modules environmentally safe while retaining their flexibility, active area efficiency, and stability. The substitution of silver with carbon does not affect the roll‐to‐roll manufacturing of the modules and allows for the same fast printing and coating. The use of carbon as electrode material is one step closer to the wide release of low‐cost plastic solar cells and opens the door to new possible applications where silver recycling is not manageable.  相似文献   
146.
147.

Introduction

Surfactant protein D (SP-D) is a collectin with immuno-regulatory functions, which may depend on oligomerization. Anti-microbial and anti-inflammatory properties have been attributed to multimeric SP-D variants, while trimeric subunits per se have been suggested to enhance inflammation. Previously, we reported low circulating SP-D in early rheumatoid arthritis (RA), and the present investigation aims to extend these data by serial SP-D serum measurements, studies on synovial fluid, SP-D size distribution and genotyping in patients with early RA.

Methods

One-hundred-and-sixty disease-modifying antirheumatic drug (DMARD) naïve RA patients with disease duration less than six months were studied prospectively for four years (CIMESTRA (Ciclosporine, Methotrexate, Steroid in RA) trial) including disease activity measures (C-reactive protein, joint counts and Health Assessment Questionnaire (HAQ) score), autoantibodies, x-ray findings and SP-D. SP-D was quantified by enzyme-linked immunosorbent assay (ELISA) and molecular size distribution was assessed by gel filtration chromatography. Further, SP-D Met11Thr single nucleotide polymorphism (SNP) analysis was performed.

Results

Serum SP-D was significantly lower in RA patients at baseline compared with healthy controls (P < 0.001). SP-D increased slightly during follow-up (P < 0.001), but was still subnormal at four years after adjustment for confounders (P < 0.001). SP-D in synovial fluid was up to 2.5-fold lower than in serum. While multimeric variants were detected in serum, SP-D in synovial fluid comprised trimeric subunits only. There were no significant associations between genotype distribution and SP-D. Baseline SP-D was inversely associated to CRP and HAQ score. A similar relationship was observed regarding temporal changes in SP-D and CRP (zero to four years). SP-D was not associated to x-ray findings.

Conclusions

This study confirms that circulating SP-D is persistently subnormal in early and untreated RA despite a favourable therapeutic response obtained during four years of follow-up. SP-D correlated negatively to disease activity measures, but was not correlated with x-ray progression or SP-D genotype. These observations suggest that SP-D is implicated in RA pathogenesis at the protein level. The exclusive presence of trimeric SP-D in affected joints may contribute to the maintenance of joint inflammation.

Trial registration

(j.nr NCT00209859).  相似文献   
148.
SUMMARY: GeneRecon is a tool for fine-scale association mapping using a coalescence model. GeneRecon takes as input case-control data from phased or unphased SNP and microsatellite genotypes. The posterior distribution of disease locus position is obtained by Metropolis-Hastings sampling in the state space of genealogies. Input format, search strategy and the sampled statistics can be configured through the Guile Scheme programming language embedded in GeneRecon, making GeneRecon highly configurable. AVAILABILITY: The source code for GeneRecon, written in C++ and Scheme, is available under the GNU General Public License (GPL) at http://www.birc.au.dk/~mailund/GeneRecon CONTACT: mailund@birc.au.dk.  相似文献   
149.
150.
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