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   225篇
  免费   14篇
儿科学   4篇
基础医学   26篇
口腔科学   1篇
临床医学   25篇
内科学   38篇
皮肤病学   3篇
神经病学   13篇
特种医学   32篇
外科学   52篇
预防医学   16篇
眼科学   6篇
药学   17篇
肿瘤学   6篇
  2022年   2篇
  2021年   3篇
  2020年   4篇
  2019年   5篇
  2018年   2篇
  2016年   14篇
  2015年   12篇
  2014年   8篇
  2013年   10篇
  2011年   8篇
  2010年   4篇
  2009年   2篇
  2008年   8篇
  2007年   7篇
  2006年   7篇
  2005年   7篇
  2004年   7篇
  2003年   3篇
  2002年   6篇
  2001年   3篇
  2000年   5篇
  1999年   4篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   5篇
  1993年   2篇
  1992年   3篇
  1991年   11篇
  1990年   9篇
  1989年   9篇
  1988年   2篇
  1987年   3篇
  1986年   11篇
  1985年   4篇
  1983年   2篇
  1982年   2篇
  1980年   2篇
  1979年   2篇
  1975年   5篇
  1974年   3篇
  1972年   1篇
  1971年   5篇
  1970年   3篇
  1969年   1篇
  1968年   1篇
  1967年   2篇
  1965年   2篇
  1964年   1篇
  1961年   1篇
排序方式: 共有239条查询结果,搜索用时 15 毫秒
1.
On the basis of examination of 45 patients who had been operated on for tuberculoma, tumors, abscesses, echinococcosis, developmental anomalies of the lungs and bronchiectasis it is concluded that R. F. Klement's tables of the degrees of bronchial patency gradation for phthisiopulmonological patients cannot be used for characterizing bronchial patency in individuals who had undergone operation. The dependence of some indices of the flow-volume loop on the volume of the resected lung is shown. The authors claim that in order to use the above-mentioned tables in characterizing the degree of bronchial patency in patients subjected to operation, a conversion factor must be elaborated.  相似文献   
2.
3.
Cyclic peptide disulfides of the general formula were synthesized from the corresponding peptide derivatives [Boc-Cys(Trt)(Gly)-n-Cys(Trt)-OBut] by oxidation with iodine in methanol and by subsequent removal of the terminal groups with trifluoroacetic acid. Acid ionization constants of the obtained peptides were determined by potentiometric titration in aqueous KCl (0.1 mol/L) medium. All compounds have two dissociable hydrogens, corresponding to carboxyl (pK1= 2.35–2.84) and to terminal amino group (pK2= 5.61–6.93); pK1, values show first an upward and then a downward trend with the increase in ring size; the opposite is true for pK2, values. These trends could be tentatively attributed to the intramolecular salt bridge (-COO——-NH+3-) formation.  相似文献   
4.
The activity of neurons of the reticular portion of the substantia nigra before and after the microinjection of haloperidol (25 μg/5 μl) into the head of the caudate nucleus on the ipsilateral side was investigated under chronic experimental conditions in cats, using the extracellular microelectrode pickup technique. A significant (p<0.05) increase, from 34 to 61%, of neurons with the burst type of spontaneous activity was established after the injection of haloperidol. A significant increase in the ratio of the number of excitatory responses to inhibitory responses, from 0.04 to 0.4, was identified among the reactions associated with saccadic eye movements following the microinjection of haloperidol. The number of orienting saccades in response to the visual stimulus decreased against this background from 58 to 37%. The identified changes are regarded as a result of the disinhibition of GABAergic neurons of the reticular portion of the substantia nigra under the influence of the blockade of D2 dopamine receptors of the neostriatum. Department of the Physiology of the Cerebral Cortex and Subcortical Structures, A. A. Bogomolets Institute of Physiology, Academy of Sciences of Ukraine, Kiev. Translated from Fiziologicheskii Zhurnal irneni I. M. Sechenova, Vol. 80, No. 1, pp. 17–22, January, 1994.  相似文献   
5.
6.
7.
8.
GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21–5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry. Am. J. Hematol. 89:187–193, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   
9.
10.
目的 :提高贫困地区壮族农村住院分娩率 ,加强产时保健 ,提高贫困地区壮族农村产科质量 ,降低产后出血死亡率。在广西 30个老少边山穷地区 ,以项目和“母亲安全工程”为载体 ,在经济条件困难 ,基础设施落后 ,围产保健服务管理滞后的情况下 ,积极贯彻落实《母婴保健法》,依法规范围产保健服务管理 ,多方筹措资金 ,加强产科软、硬件建设 ,以项目工作为龙头 ,以科研为先导 ,积极推广适宜技术。以健康促进为目的 ,大力开展健康教育和生殖保健活动 ,使围产保健工作取得了较好成绩。30个贫困地区壮族农村近半数以上乡卫生院产科建设已达自治区标准 ,基本能满足贫困地区农民住院分娩的需求 ,并带动广西妇幼卫生工作的发展  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