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   163篇
  免费   14篇
  2023年   1篇
  2022年   2篇
  2021年   7篇
  2020年   2篇
  2019年   1篇
  2018年   2篇
  2017年   4篇
  2016年   6篇
  2015年   4篇
  2014年   8篇
  2013年   10篇
  2012年   9篇
  2011年   3篇
  2010年   6篇
  2009年   5篇
  2008年   5篇
  2007年   5篇
  2006年   4篇
  2005年   4篇
  2004年   9篇
  2003年   5篇
  2002年   5篇
  2001年   8篇
  2000年   10篇
  1999年   8篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1991年   4篇
  1989年   2篇
  1987年   4篇
  1986年   2篇
  1983年   2篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1977年   1篇
  1976年   4篇
  1974年   5篇
  1973年   4篇
  1969年   1篇
排序方式: 共有177条查询结果,搜索用时 15 毫秒
1.
Conformationally constraining selectable peptides onto a suitable scaffold that enables their conformation to be predicted or readily determined by experimental techniques would considerably boost drug discovery process by reducing the gap between the discovery of a peptide lead and the design of a peptidomimetic with a more desirable pharmacological profile. With this in mind, we designed the minibody, a 61-residue β-protein aimed at retaining some desirable features of immunogloblin variable domains, such as tolerance to sequence variability in selected regions of the protein and predictability of main chain conformation of the same regions, based on the ‘canonical structures’ model. To test the ability of the minibody scaffold to support functional sites we also designed a metal binding version of the protein by suitably choosing the sequences of its loops. The minibody was produced both by chemical syntyhesis and expression in E. coli and charactgerized by size exclusion chromatography, UV CD (circular dichroism) spectroscopy and metal binding activity. All our data supported the model, but a more detailed structural characterization of the molecule was impaired by its low soubility. We were able to overcome this problem both by further; mutagenesis of the framework and by addition of a solublizing motif. The minibody is being used to select constrained human IL-6 peptidic ligands from a library displayed on the surface of the f1 bacteriophage.  相似文献   
2.
3.
Epidermal growth factor receptors (EGFr) were studied by immunohistochemistry in human myometrium and leiomyomas from women treated with the GnRH agonist (GnRH-a) goserelin. The results were compared with those obtained from women not treated. Vessel cells of leiomyomas and myometrium were always more immunoreactive than fibrocytes and myocites. In fibroids from treated patients the histochemical score (HSCORE) of vessel cells was always significantly lower (p less than 0.001) than in control patients. Our data confirm a role of EGF also in fibroid growth and suggest that, the blood supply reduction associated with the volume reduction of these tumours, consequent to the GnRH-a treatment, could be EGF mediated.  相似文献   
4.
5.
Abstract

The Westland petrel (Procellaria westlandica) is an endemic New Zealand species and one of the very few burrowing seabird species still breeding on mainland New Zealand. It nests only on a series of coastal ridgelines near to Punakaiki on the West Coast of the South Island. Between 2002 and 2005, surveys were undertaken at 28 of the 29 known colonies. The area occupied by the colonies was 73 ha; most colonies had fewer than 50 burrows, but six colonies had 201–500 burrows and four colonies had more than 1000 burrows. We find that the current breeding range of Westland petrel and the location of individual colonies are similar to those reported in both the 1950s and 1970s. Based on total burrow counts at 28 colonies and burrow occupancy rates determined by annual monitoring, the annual breeding population is estimated to be between 2954 and 5137 breeding pairs.  相似文献   
6.
7.
Matthias Albrecht  David Kleijn  Neal M. Williams  Matthias Tschumi  Brett R. Blaauw  Riccardo Bommarco  Alistair J. Campbell  Matteo Dainese  Francis A. Drummond  Martin H. Entling  Dominik Ganser  G. Arjen de Groot  Dave Goulson  Heather Grab  Hannah Hamilton  Felix Herzog  Rufus Isaacs  Katja Jacot  Philippe Jeanneret  Mattias Jonsson  Eva Knop  Claire Kremen  Douglas A. Landis  Gregory M. Loeb  Lorenzo Marini  Megan McKerchar  Lora Morandin  Sonja C. Pfister  Simon G. Potts  Maj Rundlf  Hillary Sardias  Amber Sciligo  Carsten Thies  Teja Tscharntke  Eric Venturini  Eve Veromann  Ines M.G. Vollhardt  Felix Wckers  Kimiora Ward  Andrew Wilby  Megan Woltz  Steve Wratten  Louis Sutter 《Ecology letters》2020,23(10):1488-1498
Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control (18 studies) and pollination services (17 studies) in adjacent crops in North America, Europe and New Zealand. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimise floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.  相似文献   
8.
Hypermobile Ehlers-Danlos syndrome (hEDS), mainly characterized by generalized joint hypermobility and its complications, minor skin changes, and apparently segregating with an autosomal dominant pattern, is still without a known molecular basis. Hence, its diagnosis is only clinical based on a strict set of criteria defined in the revised EDS nosology. Moreover, the hEDS phenotypic spectrum is wide-ranging and comprises multiple associated signs and symptoms shared with other heritable or acquired connective tissue disorders and chronic inflammatory diseases. In this complex scenario, we previously demonstrated that hEDS patients' skin fibroblasts show phenotypic features of myofibroblasts, widespread extracellular matrix (ECM) disarray, perturbation of ECM-cell contacts, and dysregulated expression of genes involved in connective tissue architecture and related to inflammatory and pain responses. Herein, the cellular proteome of 6 hEDS dermal myofibroblasts was compared to that of 12 control fibroblasts to deepen the knowledge on mechanisms involved in the disease pathogenesis. Qualitative and quantitative differences were assessed based on top-down and bottom-up approaches and some differentially expressed proteins were proofed by biochemical analyses. Proteomics disclosed the differential expression of proteins principally implicated in cytoskeleton organization, energy metabolism and redox balance, proteostasis, and intracellular trafficking. Our findings offer a comprehensive view of dysregulated protein networks and related pathways likely associated with the hEDS pathophysiology. The present results can be regarded as a starting point for future in-depth investigations aimed to decipher the functional impact of potential bioactive molecules for the development of targeted management and therapies.  相似文献   
9.
10.
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