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   25710篇
  免费   1755篇
  国内免费   169篇
耳鼻咽喉   204篇
儿科学   577篇
妇产科学   472篇
基础医学   3662篇
口腔科学   259篇
临床医学   2309篇
内科学   6044篇
皮肤病学   328篇
神经病学   2529篇
特种医学   865篇
外国民族医学   1篇
外科学   4771篇
综合类   161篇
一般理论   9篇
预防医学   1573篇
眼科学   286篇
药学   1544篇
中国医学   77篇
肿瘤学   1963篇
  2023年   120篇
  2022年   243篇
  2021年   489篇
  2020年   361篇
  2019年   595篇
  2018年   648篇
  2017年   492篇
  2016年   537篇
  2015年   630篇
  2014年   884篇
  2013年   1208篇
  2012年   1814篇
  2011年   1959篇
  2010年   1190篇
  2009年   1123篇
  2008年   1718篇
  2007年   1765篇
  2006年   1650篇
  2005年   1726篇
  2004年   1526篇
  2003年   1549篇
  2002年   1575篇
  2001年   225篇
  2000年   188篇
  1999年   254篇
  1998年   335篇
  1997年   320篇
  1996年   225篇
  1995年   217篇
  1994年   173篇
  1993年   172篇
  1992年   135篇
  1991年   120篇
  1990年   116篇
  1989年   89篇
  1988年   87篇
  1987年   67篇
  1986年   101篇
  1985年   85篇
  1984年   90篇
  1983年   92篇
  1982年   100篇
  1981年   90篇
  1980年   88篇
  1979年   56篇
  1978年   45篇
  1977年   37篇
  1976年   37篇
  1975年   35篇
  1974年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
A 66-year-old man with atrial fibrillation was referred soon after developing left lower limb and abdominal pain with rectal bleeding. An immediate flush aortogram showed embolic occlusion of the left distal superficial femoral artery and superior mesenteric artery (SMA), 3 cm from its ostium. Recombinant tissue plasminogen activitor (rtPA) 40 mg was selectively in stilled in the SMA in two boluses. Abdominal symptoms resolved within 48 h, and complete recanalization of the SMA was shown on angiography. Exploratory laparotomy after 72 h showed a normal small bowel and right colon, and was completed by femoropopliteal embolectomy. Six months later, the patient remained asymptomatic.  相似文献   
44.
Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.  相似文献   
45.
Background:This study was undertaken to report our experience with major vascular injuries in gynecologic laparoscopy in order to specify the circumstances under which they occurred, the means of diagnosis, the risk factors, and the means for prevention.Study Design:Retrospective case review study.Results:Seventeen patients with 21 major vascular injuries were identified. The average age of the patients was 33.8 ± 11.6 years, and the mean body index mass was 21.6 ± 3.08 kg/m2. Three of four of the accidents occurred during the set-up phase of laparoscopy (13 cases; 76.5%), and in 4 cases (23.5%) the accident occurred during the laparoscopic surgery procedure. Eleven (84.6%) of the complications occurring during the set-up phase were secondary to insertion of the umbilical trocar and 2 (15.4%) to insertion of the needle used to create the pneumoperitoneum (P-needle). Half (6 cases; 54.5%) of the major vascular injuries secondary to insertion of the umbilical trocar were observed when reusable trocars were used. In every case, the diagnosis was made during the operation. Two patients died, and two others presented a serious complication (phlebitis; acute ischemia requiring reoperation).Conclusions:Major vascular injuries are rare but serious complications of laparoscopic surgery. Prevention of these accidents relies on the surgeon’s experience and scrupulous respect of the safety rules. In the vast majority of cases, it is necessary to convert to laparotomy immediately, calling in a vascular surgeon.  相似文献   
46.
47.
Summary Simultaneous tumors are rarely encountered during the course of acute leukemias. We report on a case of seminoma of the testis that occurred during the evolution of acute myelogenous leukemia. To our knowledge, this stimultaneous association has not previously been described, but a causal relationship was not apparent in the present case. The likelihood of a common carcinogenesis existed, but direct exposure to carcinogens could not be established. Although the results of a physical examination and echography were normal at the time of diagnosis, we cannot exclude the presence of microscopic cancer of the testis. Since the dissemination pattern of seminoma is usually slower than that observed in this case and the disease remains limited to the lymph nodes for long periods following dissemination, the rapid development of the present case might have been attributable to the immunosuppression and the scrotal sepsis that occurred during the induction therapy. Immunosuppression might have stimulated the progression of a primary microscopic seminoma and the development of metastasis, whereas the scrotal sepsis and inflammation might have favored the occurrence of metastasis through bypass of the lymphatic barrier.  相似文献   
48.
49.
50.
Congenital dislocation of the hip (CDH) in an adult can accompany or cause mechanical low-back pain. This in turn, can create confusion in making the proper diagnosis. The mechanical alterations caused by CDH create an added strain to the lumbosacral spine. Manipulative treatment for back pain in these patients must not subject the dislocated hips to undue torque.  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