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   244篇
  免费   26篇
  国内免费   13篇
儿科学   12篇
妇产科学   1篇
基础医学   31篇
口腔科学   5篇
临床医学   40篇
内科学   54篇
皮肤病学   2篇
神经病学   4篇
特种医学   80篇
外科学   8篇
综合类   2篇
预防医学   10篇
眼科学   2篇
药学   17篇
中国医学   1篇
肿瘤学   14篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   6篇
  2016年   1篇
  2015年   2篇
  2014年   1篇
  2013年   3篇
  2012年   2篇
  2011年   3篇
  2010年   6篇
  2009年   2篇
  2008年   2篇
  2007年   9篇
  2006年   1篇
  2005年   7篇
  2004年   1篇
  2003年   2篇
  2002年   5篇
  2001年   4篇
  2000年   3篇
  1999年   6篇
  1998年   22篇
  1997年   19篇
  1996年   16篇
  1995年   14篇
  1994年   11篇
  1993年   10篇
  1991年   1篇
  1990年   4篇
  1989年   14篇
  1988年   21篇
  1987年   9篇
  1986年   9篇
  1985年   4篇
  1984年   6篇
  1983年   4篇
  1982年   12篇
  1981年   5篇
  1980年   6篇
  1979年   4篇
  1978年   3篇
  1977年   8篇
  1976年   6篇
  1975年   5篇
排序方式: 共有283条查询结果,搜索用时 21 毫秒
91.
92.
93.

Background  

This WHO study aimed to support Turkey in its efforts to strengthen the primary care (PC) system by implementing the WHO Primary Care Evaluation Tool (PCET). This article provides an overview of the organization and provision of primary care in Turkey.  相似文献   
94.
Background: Patients with initial transient ischaemic attack (TIA) subsequently have a higher risk of recurrent TIA or acute ischemic stroke (AIS). The role of scoring intracranial arterial calcification (IAC) in predicting the prevalence of stroke remains unclear. We aim to evaluate if radiological CT calcium score measuring IAC burden could predict future ischemic events in a cohort of TIA patients. Methods: We studied consecutive patients from July 2014 to December 2015 who presented with first episode of TIA. All patients had noncontrasted CT or CT-angiogram of the brain on admission. CT calcium score (cm3) was quantified by measuring calcium deposition in the bilateral internal carotid arteries, middle cerebral arteries, and vertebrobasilar system. Patients were followed up for 2 years and ischemic events for either recurrent TIA or AIS were recorded. We compared patients in terms of clinical profile at presentation and CT calcium score using appropriate univariate and multivariable analyses. Results: Of 156 TIA patients studied, 22% (n = 35) had recurrent TIA or AIS within 2 years of follow-up. On univariate analyses, recurrent TIA/AIS was associated with gender (OR 0.61; 95%CI 0.40-0.95; P = .038), hypertension (mean difference 2.49; 95%CI 1.08-5.75; P = .030) and higher CT calcium score (mean difference 0.84 95%CI 0.16-1.52 P = .016). On multivariable logistic regression, a higher CT calcium score was significantly associated with recurrent TIA/AIS (adjusted OR 1.25 95%CI 1.01-1.55 P = .042). Conclusions: In TIA patients, higher IAC burden by measurement of a quantitative CT calcium score may be associated with recurrent ischemic events.  相似文献   
95.
Andreesen  R; Brugger  W; Thomssen  C; Rehm  A; Speck  B; Lohr  GW 《Blood》1989,74(6):2150-2156
Macrophages (MAC) are important effector cells of the immune system but also play an essential role as regulatory cells in hematopoiesis. They originate from circulating monocytes (MO) as immature precursor cells that undergo terminal differentiation upon migration from the capillary bed into the various tissues. In the presence of serum, MAC maturation from blood MO is observed in vitro and can be followed by the expression of maturation-associated antigens (MAX.1, .3, .11, and .26; transferrin receptor, 13C2, CD16). We have tested blood MO from 22 patients with aplastic anemia (AA) for their capacity to undergo terminal maturation in vitro. After isolation, blood MO in six patients expressed CD14 molecules at low density when compared to normals. On culture for 7 days, in 15 patients various abnormalities could be shown by phenotype analysis using cell-enzyme-linked immunosorbent assay (ELISA) and an immunoperoxidase staining technique of single cells. Abnormalities ranged from the distinctive failure of mature MAC to express single surface antigens (eg, gp64-MAX.1) to complete inhibition of the development of a MAC maturation-associated phenotype. In three patients the maturational defect was found to persist in complete remission after successful therapy with antileukocyte globulin (ALG). Neither in other immunosuppressed or multiple-transfused patients nor in those with bone marrow hypoplasia secondary to cancer chemotherapy and during hematologic reconstitution following autologous bone marrow transplantation (BMT), defective MO maturation in vitro was seen. Our data provide evidence for the existence of serious disorders within the MO-MAC lineage in patients with AA. This observation may either reflect the stem-cell defect or indicate a MAC involvement in the pathogenesis of the disease.  相似文献   
96.
This review concerns the reasons why only an estimated 10–15% of patients with alpha-1-antitrypsin (A1AT) deficiency develop the destructive lung disease known as emphysema. The arguments presented revolve around the proteinase-antiproteinase balance in the 'microenvironment' of the epithelial space of the lung. Attention is focused on the balance between destructive enzymes such as neutrophil elastase and protective proteins such as A1AT, secretory leucocyte proteinase inhibitor (SLPI), human elastase inhibitor (HEI) and elafin. When neutrophil elastase is already attached to the elastin fibres the smaller molecules SLPI and elafin appear to be better inhibitors of this enzyme than larger inhibitors such as A1AT and HEI. Furthermore, SLPI and elafin may provide the first line of defence against proteinase attack from neutrophil elastase. In trying to explain the variability in the clinical expression of A1AT-deficiency and the development of emphysema, the importance of changes to A1AT, SLPI and elafin molecules induced by smoking and/or oxygen free radicals has been considered. It is possible that emphysema only develops in patients who have SLPI/elafin deficiency as well as A1AT deficiency.  相似文献   
97.
98.
目的:观察电针对单纯性肥胖大鼠下丘脑瘦素和神经肽Y表达的影响,探索电针减肥的机制。方法:实验于2005-12/2006-06在中南大学湘雅医院中西医结合研究所实验室完成。①取1月龄刚断乳SD雄性大鼠,随机取6只饲以普通饲料为正常对照组,其他大鼠饲以高脂饲料,喂养3个月后,选择体质量超过正常对照组20%的单纯性肥胖大鼠12只,随机分为模型组和电针组2组,每组6只。②电针组大鼠电针双侧足三里、天枢、三阴交穴,采用疏密波,电流强度0.3~0.6mA,留针20min,1次/d,共20次;其他2组不电针。实验期间均饲以普通饲料。③观察实验大鼠体质量、体长、Lee's指数及体脂,采用Western-blot技术检测下丘脑组织中瘦素、神经肽Y表达的变化。结果:18只大鼠进入结果分析。①模型组大鼠体质量和Lee’s指数高于正常对照组[(451.8±14.8),(323.6±6.8)g;324.25±1.4,305.14±1.5;P均<0.01];电针组电针后体质量和Lee’s指数低于电针前[(372.2±20.4),(454.7±19.7)g;307.71±1.5,323.56±1.6;P均<0.01]。②模型组大鼠心包、肾周和附睾脂肪量均高于正常对照组(P<0.01);电针组电针后心包、肾周和附睾脂肪量低于电针前(P<0.01)。③模型组下丘脑组织中瘦素蛋白表达低于正常对照组(0.62±0.11,0.88±0.15,P<0.01),电针组高于模型组(0.85±0.13,P<0.01);模型组下丘脑组织中神经肽蛋白表达高于正常对照组(2.42±0.27,1.75±0.24,P<0.01),电针组高于模型组(1.87±0.21,P<0.01)。结论:电针有良好的减肥效果,其作用可能与电针增强下丘脑组织瘦素蛋白的表达、同时抑制下丘脑组织中的神经肽Y蛋白表达有关。  相似文献   
99.
目的:观察仰卧位和俯卧位心脏对煤尘肺患者肺组织体积和肺功能的影响,为临床应用俯卧位治疗成人呼吸窘迫综合征等肺部疾病提供依据。方法:2006-08/2007-01河南鹤煤集团公司总医院放射科对10例煤尘肺患者行仰、俯卧位高分辨螺旋CT扫描,分别测量位于心脏下方肺组织的体积,测量仰、俯卧位状态下肺功能,用配对t检验进行统计学分析。结果:10例患者均进入结果分析。①CT扫描心脏压迫下的肺组织体积:俯卧位时均小于仰卧位[左肺:(7.74±9.55),(242.60±72.11)mm3;右肺:(12.21±11.41),(156.49±76.54)mm3,P均<0.01]。②肺功能测量结果:仰卧位时,患者的用力肺活量、第1秒用力呼气容积、第1秒用力呼气容积预计值百分率、最大呼气量,分别为(2.14±0.58)L、(1.62±0.79)L、(89.80±29.26)、(3.42±1.98)L/s;俯卧位时,患者的用力肺活量、第1秒用力呼气容积、第1秒用力呼气容积预计值百分率、最大呼气量,分别为(2.36±20.79)L、(1.80±0.77)L、(100.10±22.46)、(4.30±2.37)L/s。俯卧位时肺功能明显优于仰卧位(P<0.05)。结论:俯卧位时位于心脏下方的肺组织明显减少,可显著改善人体的肺换气功能。  相似文献   
100.
Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis cases in the Ukraine are increasing. Pyrazinamide (PZA) is critically important for first- and second-line tuberculosis (TB) treatment regimes. However, PZA drug susceptibility testing is time consuming and technically challenging. The present study utilized Next-generation sequencing (NGS) to identify mutations in the pncA gene from clinical isolates and to assess the prevalence of pncA gene mutations in MDR/XDR-TB patients. Clinical isolates were inactivated in molecular transport media and shipped from Kharkiv, Ukraine, to San Antonio, TX. Whole-genome and targeted pncA gene sequencing was carried out using Illumina MiSeq instrumentation. Mutations were noted in 67 of 91 (74%) clinical isolates comprising substitutions, insertions, and deletions in the pncA coding and upstream promoter region. Of 45 mutation types, there were 11 novel, i.e., to date unknown, pncA mutations identified of which 3 were confirmed PZA resistant. Seven isolates contained mixed base mutations, whereas 4 harbored doubled mutations. Data reported here further support use of NGS for pncA gene characterization and may contribute in significant fashion to PZA therapy, especially in MDR- and XDR-TB patients.  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