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   428篇
  免费   52篇
  国内免费   1篇
  2023年   4篇
  2022年   12篇
  2021年   12篇
  2020年   15篇
  2019年   44篇
  2018年   34篇
  2017年   13篇
  2016年   17篇
  2015年   21篇
  2014年   27篇
  2013年   34篇
  2012年   27篇
  2011年   38篇
  2010年   12篇
  2009年   16篇
  2008年   24篇
  2007年   18篇
  2006年   9篇
  2005年   16篇
  2004年   14篇
  2003年   11篇
  2002年   14篇
  2001年   11篇
  2000年   2篇
  1999年   3篇
  1998年   3篇
  1996年   3篇
  1995年   2篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   4篇
  1983年   2篇
  1981年   1篇
  1974年   1篇
  1970年   1篇
排序方式: 共有481条查询结果,搜索用时 14 毫秒
71.
72.
Breast cancer (BC) is the most commonly diagnosed cancer in women. The PI3K/AKT/mTOR pathway is among the most frequently dysregulated pathways in patients with BC. The activation of this pathway is associated with increased cell growth and clinical outcome, and its overexpression is associated with a poor prognosis. It has been proposed that it may be of importance as a potential therapeutic target in the treatment of BC. The aim of current review is to provide an overview of the potential utility of PI3K/Akt/mTOR inhibitors in patients with BC, with particular emphasis on recent preclinical and clinical studies. J. Cell. Biochem. 119: 213–222, 2018. © 2017 Wiley Periodicals, Inc.  相似文献   
73.
74.
Brucellosis is regarded as one of the most common diseases among humans and livestock. In the present study, we aimed to assess the effect of this disease on the level of various cations including copper (Cu), manganese (Mn), zinc (Zn), and magnesium (Mg) as well as oxidative stress status in the serum of people suffering from brucellosis. The present case-study was carried out on 40 patients with brucellosis (case) and 20 healthy people (control). Blood specimens were taken from all the people and the level of essential trace elements and oxidative stress status were measured. The serum level of copper in the case group (165.39 ± 43.19 μg/dl) was significantly higher compared with that in the control group (122.12 ± 28.88 μg/dl). Whereas the serum level of zinc was significantly lower in the case group compared with that in the control group (76.47 ± 28.88 vs. 92.85 ± 23.16 μg/dl). The manganese and magnesium serum levels did not differ significantly between the two groups. Furthermore, total antioxidant capacity level was significantly lower in the case group (122.12 ± 28.22 μmol/ml) than that in the control group (3.08 ± 0.12 μmol/ml) and the level of serum malondialdehyde was significantly higher in the case group (7.20 ± 0.23 mmol/ml) than that in the control group (4.0 ± 0.19 mmol/ml). Brucellosis can cause alteration in the serum level of essential trace elements. Moreover, the present study indicated that brucellosis produces oxidative stress in patients.  相似文献   
75.
The interactions between estradiol and two carrier proteins, i.e. human serum albumin (HSA) and holo-transferrin (HTF) in aqueous solution at pH = 7.4 were studied by three-dimensional fluorescence emission spectroscopy, isothermal titration calorimetry (ITC), zeta-potential, resonance light-scattering and molecular modeling. Extensive fluorescence quenching was observed throughout the interaction between the drug and both proteins. Moreover, conformational changes were determined by observing the rearrangement of Trp residues during binding of estradiol with HSA and HTF at different concentrations. ITC experiments revealed that, in the presence of estradiol, both van der Waals forces and hydrogen bonding became predominant. In addition, other binding parameters such as enthalpy and entropy changes were determined by the zeta potential method. Molecular modeling suggested that estradiol was situated within sub-domain IB sited in the hydrophobic cluster in Site I, whereas the drug was located in the N-terminal of HTF where it was hydrogen bonded with Ala 670.  相似文献   
76.
77.
78.
Telmatochromis temporalis is a biparental substrate breeding cichlid that mates in size-assortative monogamy at the southern end of Lake Tanganyika. In this population, at least a few months before the rainy season, large males (90–110 mm TL) did not pair. However, they maintained large territories that were defended against conspecific large males and that contained several pairing small males (50–80 mm). Large males occasionally visited the nests of the small pairs in their territories, and selectively took over the nests by attacking the owner male. During the takeover, the large males courted the small females in the nests and might have ejaculated sperm. After the large males left the nests, the small owner males conducted paternal care at the nests. These behaviour patterns of large males are similar to piracy mating reported in other polygamous fish species. The piracy mating of large maleT. temporalis seems to be an alternative tactic when large females are not available.  相似文献   
79.
The interaction between synthesized heterocyclic benzene sulfonamide compounds, N-(7-benzyl-56-biphenyl-2m-tolyl-7H-pyrrolo[23-d]pyrimidine–4–yl)-benzene sulfonamide (HBS1), N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d] pyrimidine-4-yl)-4-methyl- benzene sulfonamide (HBS2), and N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d]pyrimidine-4-yl)-4-chloro-benzene sulfonamide (HBS3) with Hb was studied by fluorescence quenching, zeta potentional, circular dichroism, and molecular modeling techniques. The fluorescence spectroscopy experiments were performed in order to study the conformational changes, possibly due to a discrete reorganization of Trp residues during binding between HBS derivatives and Hb. The variation of the KSV value suggested that hydrophobic and electrostatic interactions were the predominant intermolecular forces stabilizing the complex. The KSV1 ans KSV2 values of HBS derivatives with Hb are .6 × 1013 and 3 × 1013 M?1 for Hb–HBS1, 1 × 1013 and 4 × 1013 M?1 for Hb–HBS2, .9 × 1013, and 6 × 1013 M?1 for Hb–HBS3, respectively. The molecular distances between Hb and HBS derivatives in binary and ternary systems were estimated according to Förster’s theory of dipole–dipole non-radiation energy transfer. The quantitative analysis data of circular dichroism spectra demonstrated that the binding of the three HBS derivatives to Hb induced conformational changes in Hb. Changes in the zeta potential of the Hb–HBS derivatives complexes demonstrated a hydrophobic adsorption of the anionic ligand onto the surface of Hb as well as both electrostatic and hydrophobic adsorption in the case of the complex. The modeling data thus confirmed the experimental results. This study is expected to provide important insight into the interaction of Hb with three HBS derivatives to use in various toxicological and therapeutic processes.  相似文献   
80.
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