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   267篇
  免费   12篇
  国内免费   1篇
儿科学   20篇
妇产科学   9篇
基础医学   83篇
口腔科学   1篇
临床医学   32篇
内科学   43篇
神经病学   8篇
特种医学   37篇
外科学   10篇
综合类   19篇
预防医学   4篇
眼科学   1篇
药学   3篇
肿瘤学   10篇
  2020年   2篇
  2019年   2篇
  2018年   6篇
  2017年   1篇
  2016年   4篇
  2015年   7篇
  2014年   6篇
  2013年   7篇
  2012年   5篇
  2011年   2篇
  2010年   14篇
  2009年   9篇
  2008年   2篇
  2007年   7篇
  2006年   12篇
  2005年   3篇
  2004年   3篇
  2003年   4篇
  2002年   5篇
  2001年   2篇
  2000年   2篇
  1999年   11篇
  1998年   19篇
  1997年   19篇
  1996年   21篇
  1995年   14篇
  1994年   14篇
  1993年   7篇
  1992年   5篇
  1991年   5篇
  1990年   2篇
  1989年   4篇
  1988年   6篇
  1987年   7篇
  1986年   7篇
  1985年   3篇
  1984年   6篇
  1983年   8篇
  1982年   6篇
  1981年   3篇
  1980年   4篇
  1977年   2篇
  1976年   2篇
排序方式: 共有280条查询结果,搜索用时 250 毫秒
81.
The aim of this study was to investigate the association between epilepsy and perinatal brain injury in a cohort of 610 infants born preterm at <33 weeks' gestation. The prevalence of epilepsy in this cohort was 4.3% as determined by a postal questionnaire survey. Most children with epilepsy (16 of 24) had high-risk cranial ultrasound lesions including haemorrhagic parenchymal infarction (HPI), posthaemorrhagic hydrocephalus, and cystic periventricular leukomalacia (PVL). Of all the children in our cohort with high-risk brain lesions, those with epilepsy were more likely to have HPI and significantly less likely to have cystic PVL, although it is possible that PVL was not noticed in some cases. Children with epilepsy and high-risk cranial ultrasound lesions also showed more cognitive impairment than children with high-risk lesions but no epilepsy, which suggested more cortical grey-matter damage. We suggest that brain injury has occurred outside the confines of the periventricular white matter in this group of preterm infants with epilepsy.  相似文献   
82.
Eighteen fetuses with marker chromosomes were detected at diagnostic amniocentesis in our laboratory among 15 781 amniocentesis samples. Using combined approaches, conventional cytogenetics including special stain techniques and fluorescence in situ hybridization (FISH), we successfully characterized 15 of them, which assisted subsequent genetic counselling. Six marker chromosomes were of sex chromosome origin, each of which substituted a missing sex chromosome, and 12 were supernumerary marker chromosomes (SMCs). Nine of the SMCs were proven to be of autosomal origin. Of those autosomal SMCs, five originated from chromosome 15, two from chromosome 18, one from chromosome 12 and one from chromosome 1. Among 16 marker chromosomes with adequate follow-up information, 50% were benign including four sex chromosome markers and four autosomal markers. Two thirds of de novo marker chromosomes were associated with abnormal outcomes, while all inherited ones were benign regardless of their parental origin. Our study demonstrated that molecular characterization of prenatal marker chromosomes is of great significance in facilitating phenotype-genotype correlation.  相似文献   
83.
Background The major strategy for palliation of cyanotic lesions in neonates is the systemic to pulmonary arterial shunt. Methods Between May 1995, and December 2002, 48 consecutive neonates underwent systemic to pulmonary arterial shunts for cyanosis with reduced pulmonary blood flow. The mean age was 11.6 days (±SD 7.38) and the mean weight, 3.2kg (±SD 0.52). The babies were classified into three groups: Group I-Tetralogy-pulmonary Atresia (n=18), Group II-single Ventricle-Pulmonary atresia without (n=19) and with (n=5) isomerism, Group III-Pulmonary Atresia with Intact ventricular septum (n=6). Diagnosis was made by 2D echocardiography. Indication for cardiac catheterization was delineation of pulmonary anatomy/ductus laterality (n=4) or balloon atrial septostomy (n=4). The surgical procedure was a modified Blalock-Taussig shunt on the side of the situs. Post-operatively, no anti-coagulation or anti-platelet medication was employed. Results There was no mortality. Four cases required revision of the shunt in the immediate post-operative period for shunt thrombosis. The mean follow up was 17.54 months (±SD 8.36). In Group I, nine patients have undergone total correction with or without a conduit, while three required new arterial shunts for shunt/pulmonary artery stenosis. In Group II, nine patients have undergone bi-directional Glenn with atrial septectomy (n=2) and pulmonary artery plasty (n=4) and one patient underwent Fontan completion. In Group III, two patients underwent bi-directional Glenn and two had pulmonary valvotomy with/without right ventricular outflow tract widening. All the remaining babies are waiting for the second/final stage palliation or total correction. Conclusion Systemic to pulmonary arterial shunts in neonates is a gratifying and reasonably safe surgical procedure. Most babies become candidates for eventual univentricular/bi-ventricular repair.  相似文献   
84.
85.
86.
Four children with severe diabetic ketosis were successfully treated with a regimen of low-dose intermittent insulin infusions in the rehydrating fluid. The children all rapidly regained consciousness and tolerated oral fluids within 12 hours of admission. Hypoglycaemia and hypokalaemia, both complications of conventional large dose insulin treatment, did not occur. Plasma insulin levels obtained by this method were maintained in the optimum range recommended by S?nksen et al. (1972).  相似文献   
87.
88.
89.
Renal allografts in acute rejection: evaluation using duplex sonography   总被引:2,自引:0,他引:2  
Sixty-nine duplex sonographic studies were performed in 24 patients who had received renal allografts. After a prospective qualitative analysis of the Doppler waveforms, results were correlated with biopsy material and each patient's clinical course. Increased pulsatility of the Doppler waveform of intrarenal arterial flow constituted an abnormal study, indicating acute rejection. Overall sensitivity varied with the histologic form of rejection, with a 60% sensitivity for acute interstitial rejection with or without vascular rejection and an 82% sensitivity for acute vascular rejection. Overall specificity was 95% and 96%, respectively. Early rejection was also accurately detected in three patients less than 48 hours following kidney transplantation. Duplex sonography has a useful role in evaluating posttransplantation renal failure. Abnormal study results may obviate the need for biopsy and help in guiding clinical management.  相似文献   
90.
Members of the carcinoembryonic antigen family (CEACAMs) are widely expressed, and, depending on the tissue, capable of regulating diverse functions including tumor promotion, tumor suppression, angiogenesis, and neutrophil activation. Four members of this family, CEACAM1, CEACAM8, CEACAM6, and CEACAM3 (recognized by CD66a, CD66b, CD66c, and CD66d mAbs, respectively), are expressed on human neutrophils. CD66a, CD66b, CD66c, and CD66d antibodies each increase neutrophil adhesion to human umbilical vein endothelial cell monolayers. This increase in neutrophil adhesion caused by CD66 antibodies is blocked by CD18 mAbs and is associated with upregulation of CD11/CD18 on the neutrophil surface. To examine potential interactions of CEACAMs in neutrophil signaling, the effects on neutrophil adhesion to human umbilical vein endothelial cells of a set of CD66 mAbs was tested following desensitization to stimulation by various combinations of these mAbs. Addition of a CD66 mAb in the absence of calcium results in desensitization of neutrophils to stimulation by that CD66 mAb. The current data show that desensitization of neutrophils to any two CEACAMs results in selective desensitization to those two CEACAMs, while the cells remain responsive to the other two neutrophil CEACAMs. In addition, cells desensitized to CEACAM-3, -6, and -8 were still responsive to stimulation of CEACAM1 by CD66a mAbs. In contrast, desensitization of cells to CEACAM1 and any two of the other CEACAMs left the cells unresponsive to all CD66 mAbs. Cells desensitized to any combination of CEACAMs remained responsive to the unrelated control protein CD63. Thus, while there is significant independence of the four neutrophil CEACAMs in signaling, CEACAM1 appears to play a unique role among the neutrophil CEACAMs. A model in which CEACAMs dimerize to form signaling complexes could accommodate the observations. Similar interactions may occur in other cells expressing CEACAMs.  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