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   1659篇
  免费   124篇
  国内免费   25篇
耳鼻咽喉   1篇
儿科学   147篇
妇产科学   17篇
基础医学   165篇
口腔科学   66篇
临床医学   163篇
内科学   433篇
皮肤病学   41篇
神经病学   29篇
特种医学   329篇
外科学   115篇
综合类   25篇
预防医学   71篇
眼科学   16篇
药学   97篇
  1篇
中国医学   1篇
肿瘤学   91篇
  2023年   3篇
  2022年   7篇
  2021年   19篇
  2020年   10篇
  2019年   19篇
  2018年   23篇
  2017年   17篇
  2016年   24篇
  2015年   36篇
  2014年   29篇
  2013年   50篇
  2012年   13篇
  2011年   26篇
  2010年   43篇
  2009年   85篇
  2008年   23篇
  2007年   52篇
  2006年   45篇
  2005年   35篇
  2004年   30篇
  2003年   32篇
  2002年   30篇
  2001年   29篇
  2000年   24篇
  1999年   42篇
  1998年   101篇
  1997年   118篇
  1996年   113篇
  1995年   79篇
  1994年   84篇
  1993年   99篇
  1992年   27篇
  1991年   18篇
  1990年   23篇
  1989年   46篇
  1988年   46篇
  1987年   38篇
  1986年   44篇
  1985年   41篇
  1984年   24篇
  1983年   19篇
  1982年   19篇
  1981年   37篇
  1980年   20篇
  1979年   8篇
  1978年   9篇
  1977年   22篇
  1976年   19篇
  1975年   6篇
  1970年   1篇
排序方式: 共有1808条查询结果,搜索用时 15 毫秒
71.
Morrison  MC; Lee  MJ; Stafford  SA; Saini  S; Mueller  PR 《Radiology》1990,176(2):574-576
The authors present two cases of percutaneous cecostomy performed with a modified approach previously described for percutaneous gastrostomy and cholecystostomy. T-fastener devices were used to affix the cecum to the anterior abdominal wall; thus, the potential problem of fecal spillage was prevented. In both cases, adequate fecal drainage was provided without complication.  相似文献   
72.
We describe three patients who had typical features of hairy cell leukemia (HCL) and multiple myeloma (MM) at the same time. In two, both diagnoses were made within a short period of time, and in the third, HCL had been present for 2 yr before the appearance of a paraprotein, bone lesions, and plasma-cell infiltrates established the diagnosis of MM. Although this association has not been previously reported, cases of HCL with osteolytic lesions or a paraprotein band have been described. The cases described may represent clinical manifestations of closely related disorders arising from divergent differentiation from a common B-cell precursor rather than a chance association.  相似文献   
73.
74.
Inhibition of monocyte esterase activity by organophosphate insecticides   总被引:3,自引:0,他引:3  
Lee  MJ; Waters  HC d 《Blood》1977,50(5):947-951
Organophosphate insecticides, such as Vapona, Naled, and Rabon, are highly potent inhibitors of an enzyme found in human monocytes. The enzyme, a specific monocyte esterase, could be inhibited by Vapona in blood samples via airborne contamination at levels easily achieved from commercial slow-release insecticide strips. Fifty percent inhibition (I50)--as measured on the Hemalog D (Technicon Corp.)--occurred at solution concentrations of 0.22, 1.5, and 2.6 X 10(-6) g/liter for Vapona, Rabon, and Naled, respectively. Parathion (a thiophosphate) and Baygon (a carbamate) were less potent, with I50 values of 3.7 X 10(-5) and 1.5 X 10(-4) g/liter, respectively. Dursban (another thiophosphate) and Carbaryl (a carbamate) showed only marginal inhibition. Eserine, malathion, nicotine and pyrethrum had no inhibitory effect up to 0.5 g/liter. The occurrence of this effect in vivo has not yet been shown, nor is it clear what the implications of such an effect would be. The inhibition of this enzyme by airborne contaminants, however, may interfere with the proper functioning of the Hemalog D.  相似文献   
75.
76.
Herpetic esophagitis   总被引:1,自引:0,他引:1  
  相似文献   
77.
78.
A baby with unilateral cleft lip, midline cleft palate and hypertelorism developed meningitis in the first 48 h of life. Examination of the nasopharynx showed a soft tissue mass, which was confirmed as a basal encephalocele by computed tomography. There was also congenital hydrocephalus and the corpus callosum was absent. Surgical treatment included repair of the anterior basal skull defect, repair of the lip and palate, and ventriculo-peritoneal shunt. There is currently evidence of developmental delay and right-sided visual impairment due to Morning Glory syndrome. This case demonstrates that basal encephalocele should be considered in any baby with midline facial deformity who develops meningitis.  相似文献   
79.
This study comprised 103 preterm infants with a gestational age less than 33 weeks who were born in Tampere University Hospital and who were followed up to two years of age. Sixty-four perinatal variables were compared to ultrasound findings in the neonatal period and neurologic handicap at the age of two years. Duration of hypocarbia (PCO2 < or = 30 mmHg) during the first 72 h and hyperbilirubinemia (the mean level of serum total bilirubin) at three days of age were independently and significantly related to periventricular leukomalacia, but not directly to cerebral palsy. The only perinatal variables related independently and significantly to cerebral palsy at two years of age were periventricular leukomalacia and ventriculomegaly. According to these results, periventricular leukomalacia was the main predictor of cerebral palsy in preterm infants. In addition to hypocarbia, hyperbilirubinemia may also be involved in the pathogenesis of extensive (severe cystic) periventricular leukomalacia.  相似文献   
80.
Transient evoked otoacoustic emissions (TEOAEs) are low amplitude sound waves produced by the healthy cochlea. They can be recorded with a microphone in the external ear. TEOAEs are abolished by hearing losses of 30 dB or more. The feasibility of using TEOAEs as a screening test for hearing loss in children was studied. TEOAE recordings were attempted in 56 children attending an audiology clinic. Recordings were possible from both ears in 52 children; of these 104 ears, 32 had hearing deficits of 30 dB or more. Hearing status was compared with the results of six TEOAE screening criteria. All criteria had a sensitivity of 1.00. Four standard TEOAE criteria yielded specificities of 0.46-0.58. Two new criteria derived from analysis of limited frequencies from the TEOAE waveform gave specificities of 0.76 and 0.82. It can be concluded that, when appropriate pass/fail criteria are employed, TEOAEs are a feasible screening test in children.  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