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   1371篇
  免费   65篇
  国内免费   33篇
耳鼻咽喉   26篇
儿科学   63篇
妇产科学   20篇
基础医学   126篇
口腔科学   44篇
临床医学   129篇
内科学   365篇
皮肤病学   110篇
神经病学   41篇
特种医学   207篇
外科学   127篇
综合类   29篇
预防医学   83篇
眼科学   6篇
药学   40篇
中国医学   3篇
肿瘤学   50篇
  2019年   9篇
  2018年   8篇
  2017年   12篇
  2016年   16篇
  2015年   24篇
  2014年   25篇
  2013年   68篇
  2012年   17篇
  2011年   17篇
  2010年   48篇
  2009年   59篇
  2008年   25篇
  2007年   33篇
  2006年   27篇
  2005年   32篇
  2004年   16篇
  2003年   15篇
  2002年   22篇
  2001年   21篇
  2000年   12篇
  1999年   20篇
  1998年   84篇
  1997年   74篇
  1996年   77篇
  1995年   49篇
  1994年   63篇
  1993年   51篇
  1992年   16篇
  1991年   16篇
  1990年   26篇
  1989年   47篇
  1988年   44篇
  1987年   34篇
  1986年   30篇
  1985年   30篇
  1984年   31篇
  1983年   15篇
  1982年   21篇
  1981年   18篇
  1980年   13篇
  1979年   18篇
  1978年   14篇
  1977年   17篇
  1976年   17篇
  1975年   12篇
  1974年   8篇
  1973年   14篇
  1972年   12篇
  1971年   7篇
  1957年   7篇
排序方式: 共有1469条查询结果,搜索用时 15 毫秒
41.
42.
Ileocecal Tuberculosis   总被引:1,自引:0,他引:1  
Three cases of ileocecal tuberculosis are presented with a review of pathogenesis, diagnosis and therapy.
Emphasis is placed upon preoperative suspicion and the indications for resectional surgery in combination with antituberculous drugs in the management of the patients.  相似文献   
43.
Blood transfusion and postoperative infection in orthopedic patients   总被引:9,自引:0,他引:9  
Adverse effects of the transfusion of homologous blood on tumor recurrence and resistance to bacterial infection have been reported previously, but the findings are inconclusive. A retrospective review of patients undergoing orthopedic surgery was conducted, and the rate of the postoperative infectious complications was compared among those receiving homologous blood, autologous blood, both types, or no transfusion support. An overall postoperative infection rate of 6.1 percent was observed: 6.9 percent among persons receiving homologous blood, 5.0 percent among those receiving autologous blood, 11.9 percent among those receiving both homologous and autologous blood, and 4.9 percent among those not receiving transfusions (p = 0.37). Among patients receiving homologous blood, a subset of 15 patients received homologous whole blood and had an infection rate of 20 percent. Significant predictors of postoperative infection included increasing age, spinal surgery, high admission hematocrit, and greater time in surgery. Of factors relating to transfusion, only the use of homologous whole blood was a significant predictor of postoperative infection, which suggests a detrimental effect of homologous plasma. It can be concluded that, in this group of patients undergoing relatively nontraumatic surgery, several variables that are not related to transfusion, as well as the use of homologous whole blood, were significant predictors of postoperative infection.  相似文献   
44.
Summary 1. Twenty-two patients with infectious mononucleosis were studied by liver biopsy and paper electrophoresis of the serum proteins. The findings were compared with a similar group of 30 patients with infectious hepatitis.2. The essential histologic features of infectious mononucleosis were the presence in the hepatic sinusoids and portal tracts of chronic inflammatory cells resembling small lymphocytes, with essentially no parenchymal cell damage. Admixed with this lymphocytic infiltrate, but in relatively minimal numbers, were a few plasma cells and polymorphonuclear leukocytes. In addition, in infectious mononucleosis there were, with rare exceptions, no lipochrome-containing Kupffer cells. Thus, in the majority of cases, the histologic picture was distinct from that seen in infectious hepatitis. Only in comparing a few of the more severe infectious mononucleosis cases with subsiding infectious hepatitis cases was there any tendency for the two pictures to merge, and the distinction on histologic grounds between the two entities could be made in the great majority of cases.3. The most commonly seen abnormalities in the paper electrophoretic patterns of sera obtained from patients with infectious mononucleosis were decreased albumin, increased gamma globulin, not infrequent but variable changes in alpha2 globulin, and the presence of abnormal proteins migrating with mobilities intermediate to alpha2 and beta, and beta and gamma globulins. The abnormalities observed in infectious hepatitis were similar to those of infectious mononucleosis, except that in hepatitis alpha2 globulin was decreased more consistently, gamma globulin increased less frequently, and beta globulin, which was normal in practically all the cases of infectious mononucleosis, was increased in a considerable number of cases.4. Treatment of patients with infectious mononucleosis need not include prolonged bed rest and restriction of activity in an effort to avoid the development of chronic liver disease.  相似文献   
45.
Summary The management of pilonidal cyst disease in a large military hospital is described. Of special interest to the military practice is the “buddy” system, in which patients help one another to keep their wounds clean and dry. The specific objectives of our technic are: 1) obtaining excellent hemostasis by the use of zinc peroxide paste; 2) avoiding recurrences by an open-wound method of treatment; 3) preservation of a pad of subcutaneous tissue over the postsacral fascia, thus reducing long-term morbidity by insuring a mobile scar; 4) decreasing the duration of hospitalization, achieved by frequently drying the wounds with warm air. Read at the meeting of the American Proctologic Society, Hollywood, Florida, April 12 to 16, 1970. The opinions or assertions contained herein are those of the authors and are not to be construed as official or as reflecting the views of the Navy Department.  相似文献   
46.
47.
48.
Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused most often by mutations in the vasopressin V2 receptor (AVPR2). We studied a family which included a female patient with NDI with symptoms dating from infancy. The patient responded to large doses of desmopressin (dDAVP) which decreased urine volume from 10 to 4 I/day. Neither the parents nor the three sisters were polyuric. The patient was found to be a compound heterozygote for two novel recessive point mutations in the aquaporin-2 (AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is the site for inhibition of water permeation by mercurial compounds and is located near to the NPA motif conserved in all aquaporins. Osmotic water permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2 was not increased over water control, while expression of L22V cRNA increased the Pf to approximately 60% of that for wild-type AQP2. Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO cells showed that the C181W mutant had an endoplasmic reticulum-like intracellular distribution, whereas L22V and wild-type AQP2 showed endosome and plasma membrane staining. Water permeability assays showed a high Pf in cells expressing wild-type and L22V AQP2. This study indicates that AQP2 mutations can confer partially responsive NDI.   相似文献   
49.
Factors involved in the stability of trinucleotide repeats during transmission were studied in 139 families in which a full mutation, premutation or intermediate allele at either FRAXA or FRAXE was segregating. The transmission of alleles at FRAXA, FRAXE and four microsatellite loci were recorded for all individuals. Instability within the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for FRAXE) was extremely rare; only one example was observed, an increased in size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were unstably transmitted. Instability was more frequent for FRAXA intermediate alleles that had a tract of pure CGG greater than 37 although instability only occurred in two of 13 such transmissions: the changes observed were limited to only one or two repeats. Premutation FRAXA alleles over 100 repeats expanded to a full mutation during female transmission in 100% of cases, in agreement with other published series. There was no clear correlation between haplotype and probability of expansion of FRAXA premutations. Instability at FRAXA or FRAXE was more often observed in conjunction with a second instability at an independent locus suggesting genomic instability as a possible mechanism by which at least some FRAXA and FRAXE mutations arise.   相似文献   
50.
A pilot study was designed to examine whether the outcome of embryo transfer in women with a hydrosalpinx might be improved by surgical drainage of the hydrosalpinx at the time of oocyte collection for in- vitro fertilization treatment. A comparative, controlled but retrospective analysis of the results was performed of all women with infective tubal damage aged <40 years old, who had ovulatory cycles, a normal uterus and a partner with normal spermatozoa. A standardized treatment regimen was used. A maximum of three embryos were transferred. Hydrosalpinx was defined by prior hysterosalpingography and/or laparoscopy with transcervical dye injection. A total of 237 embryo transfer cycles in women with hydrosalpinges (tubal distension not visible in 151, visible but not drained in 30 and drained in 56) were compared with 705 embryo transfer cycles in women with tubal disease but no hydrosalpinx. Results were analysed in the first three cycles but also separately in the first cycle to check for bias. Success rates were higher in the first cycle, but did not significantly influence overall differences. Implantation rates were significantly reduced overall in the hydrosalpinx group (8.0 versus 13.2% for controls; P < 0.001), being 8.3% (P < 0.01) in the subgroup without evident tubal distension and 7.5% (not significant) in the drained hydrosalpinx group. This study shows that tubal damage with distal occlusion is associated with a marked reduction in embryo implantation, even in the absence of obvious fluid distension. Surgical drainage of distended hydrosalpinges appears to offer no benefit.   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