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   402篇
  免费   20篇
  国内免费   11篇
耳鼻咽喉   1篇
儿科学   27篇
妇产科学   2篇
基础医学   39篇
口腔科学   2篇
临床医学   38篇
内科学   67篇
皮肤病学   7篇
神经病学   9篇
特种医学   132篇
外科学   23篇
综合类   30篇
预防医学   12篇
眼科学   11篇
药学   15篇
中国医学   3篇
肿瘤学   15篇
  2022年   1篇
  2021年   2篇
  2020年   3篇
  2019年   3篇
  2018年   6篇
  2016年   4篇
  2015年   6篇
  2014年   7篇
  2013年   19篇
  2012年   6篇
  2011年   5篇
  2010年   13篇
  2009年   15篇
  2008年   13篇
  2007年   17篇
  2006年   6篇
  2005年   8篇
  2004年   5篇
  2003年   7篇
  2002年   8篇
  2001年   6篇
  2000年   4篇
  1999年   5篇
  1998年   40篇
  1997年   34篇
  1996年   18篇
  1995年   13篇
  1994年   14篇
  1993年   15篇
  1992年   1篇
  1991年   2篇
  1990年   9篇
  1989年   9篇
  1988年   11篇
  1987年   10篇
  1986年   12篇
  1985年   15篇
  1984年   4篇
  1983年   5篇
  1982年   10篇
  1981年   7篇
  1980年   9篇
  1979年   1篇
  1978年   10篇
  1977年   7篇
  1976年   4篇
  1975年   3篇
  1970年   1篇
排序方式: 共有433条查询结果,搜索用时 15 毫秒
81.
82.
Focal non-epidermolytic palmoplantar keratoderma (PPK or palmoplantar ectodermal dysplasia type III) is associated with oesophageal cancer in three families: two large pedigrees located in Liverpool, UK and in the midwestern American states and one smaller family from Germany. In these families, the PPK is inherited as autosomal dominant and has a late onset, usually manifesting between 7 and 8 years of age. The disease is characterised by thickening of the pressure areas of the soles, but is not restricted to the feet and also presents with oral leukokeratosis and follicular hyperkeratosis. The disease locus [previously termed the "tylosis oesophageal cancer gene' (TOC) locus] has been mapped to 17q23-qter by linkage analysis. This region is located telomeric to the keratin 16 gene, in which mutations have been identified in focal PPK families who show no increased cancer risk. We describe the close mapping of this locus to the interval between AFMb054zf9 and D17S1603 using haplotype analysis of additional Genethon markers in the region and show that although the American family is unlikely to be related to either of the other two, the UK and German pedigrees may share a common descent. This work provides a basis for positional cloning and candidate gene analysis in order to identify a gene that may be involved in familial oesophageal cancer.   相似文献   
83.
Left ventricular hypertrophy is well established as a blood pressure independent cardiovascular risk factor in patients on renal replacement therapy. The effects of antihypertensive treatment on myocardial structure and function in renal transplant recipients have been so far only rarely investigated. In a double-blind, placebo-controlled study patients were randomized to the calcium channel blocker nitrendipine or placebo if the transplanted kidney had developed a stable phase. Normotensive patients received nitrendipine 2 x 5 mg daily or placebo, hypertensive patients received 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. To achieve adequate blood pressure control, all patients with still elevated blood pressure on study medication received antihypertensive drugs other than calcium channels blockers. Ambulatory blood pressure recording and 2D-guided M-mode echocardiography were performed at baseline and upon completion of the study. In addition, laboratory workup (including serum creatinine and lipids) was done, and serum aldosterone, plasma renin activity, plasma angiotensin II and blood glucose levels were measured in all patients at baseline and after at least 12 months of therapy. Ambulatory blood pressure was almost identical between both groups at study baseline and follow-up. In renal transplant patients on nitrendipine, posterior wall thickness (-0.10 +/- 1.77 mm) and septal wall thickness (-0.83 +/- 2.23 mm) did not change significantly from baseline. In contrast, posterior wall thickness (0.71 +/- 0.92 mm, P < 0.01) and septal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patients on placebo, which differed from the observed changes on nitrendipine (ANOVA: P = 0.093 and P = 0.048, respectively). Relative wall thickness, a parameter for concentric left ventricular hypertrophy, became numerically smaller on nitrendipine therapy from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02 +/- 0.09, NS) but increased from 0.42 +/- 0.08 to 0.48 +/- 0.08 in the placebo arm (+0.04 +/- 0.08, P < 0.02), which was also significant between the two groups (ANOVA: P = 0.036). Endocrine parameters, lipids and blood glucose were not different between the two groups. We conclude from these data that the calcium channel blocker nitrendipine exerted beneficial effects on cardiac structure in patients after renal transplantation independent of blood pressure.   相似文献   
84.
Cavernous haemangiomas of the central nervous system are vascular malformations best imaged by MRI. They may present at any age, but to our knowledge only 39 cases in the first year of life have previously been reported. A familial form has been described and some of the underlying genetic mutations have recently been discovered. We present the clinical features and serial MRI findings of an 8‐week‐old boy who presented with subacute intracranial haemorrhage followed by rapid growth of a surgically proven cavernous haemangioma, mimicking a tumour. He also developed new lesions. A strong family history of neurological disease was elucidated. A familial form of cavernous haemangioma was confirmed by identification of a KRIT 1 gene mutation and cavernous haemangiomas in the patient and other family members. We stress the importance of considering cavernous haemangiomas in the context of intracerebral haemorrhage and in the differential diagnosis of rapidly growing lesions in this age group. The family history is also important in screening for familial disease.  相似文献   
85.
86.
87.
88.
Peripherally inserted central catheters: experience in 523 children   总被引:5,自引:0,他引:5  
  相似文献   
89.
The incidence of cytomegalovirus (CMV) infection was determined in 114 transfused neonates of any birthweight born to CMV antibody-negative mothers. In a second phase of this study, an additional 28 transfused infants weighing less than 1250 g, born to both CMV antibody-negative and antibody-positive mothers, were followed. All infants underwent weekly virus culture and monthly serology during hospitalization and at 6 to 12 weeks after their last transfusion. Only one of 126 (0.8%) seronegative infants and one of 16 (6.3%) seropositive infants developed CMV infection. If the assumption is made that the CMV-infected infant received only 1 unit of infectious blood, the risk of transfusion-acquired CMV infection to seronegative infants is 0.16 percent per cellular unit transfused or 0.37 percent per seropositive cellular unit transfused. Despite similarities in the prevalence of CMV antibody in the donor population, the age of blood products used, and the mean number of donor exposures, a significantly lower incidence of CMV infection was found in the seronegative transfused infants than that in two previously published studies (p less than 0.01, p less than 0.001). Because no mortality and very little morbidity could be attributed to transfusion-acquired CMV infection in the nurseries, the authors can see no justification for the provision of specialized blood components for the prevention of CMV infection in this patient population.  相似文献   
90.
Objective : To determine whether selective aortic arch perfusion (SAAP) using serial infusions of oxygenated perflubron emulsion combined with aortic epinephrine (AoE) administration is more effective than conventional therapy in treating cardiac arrest.
Methods : An experimental cardiac arrest model (10 min ventricular fibrillation and 2 min CPR) was used with 12 mixed-breed canines, randomized into 2 groups: control ( n = 6), CPR and IV epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min; or AoE-SAAP ( n = 6), CPR and aortic epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min, and serial SAAP with oxygenated 60% weightholume (w/v) perflubron emulsion as follows: 300 mL over 30 sec at 12 rnin as continuous SAAP without CPR; 150 mL over 20–30 sec at 15 min and 18 rnin as pulsed diastolic SAAP during CPR.
Results : AoE-SAAP resulted in increased coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC) compared with control. CPR-diastolic (release phase) CPP during pulsed diastolic SAAP was similar to or greater in magnitude than the CPP generated during the initial SAAP infusion without CPR. ROSC for control was 0/6 and for AoE-SAAP was 416 (p < 0.05, Fisher's exact test). Time from initiation of CPR to ROSC with a sustained systolic aortic pressure >60 mm Hg was 8.0 ± 1.2 rnin in the 4 resuscitated AoE-SAAP animals.
Conclusion : The combination of AoE with SAAP infusions of oxygenated perflubron emulsion was more effective than conventional resuscitation therapy. Pulsed diastolic SAAP is a promising method for performing SAAP.  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