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   122828篇
  免费   6346篇
  国内免费   151篇
耳鼻咽喉   1871篇
儿科学   5395篇
妇产科学   4026篇
基础医学   17223篇
口腔科学   3014篇
临床医学   8878篇
内科学   23469篇
皮肤病学   3561篇
神经病学   9538篇
特种医学   5429篇
外国民族医学   34篇
外科学   20075篇
综合类   1651篇
一般理论   30篇
预防医学   6267篇
眼科学   3479篇
药学   8375篇
中国医学   326篇
肿瘤学   6684篇
  2018年   994篇
  2017年   851篇
  2016年   1217篇
  2015年   1344篇
  2014年   1751篇
  2013年   2583篇
  2012年   3396篇
  2011年   3492篇
  2010年   2127篇
  2009年   2099篇
  2008年   3541篇
  2007年   3811篇
  2006年   3941篇
  2005年   3998篇
  2004年   3948篇
  2003年   3845篇
  2002年   3751篇
  2001年   7231篇
  2000年   7200篇
  1999年   6049篇
  1998年   1691篇
  1997年   1621篇
  1996年   1381篇
  1995年   1247篇
  1994年   1132篇
  1993年   1161篇
  1992年   3874篇
  1991年   3682篇
  1990年   3663篇
  1989年   3449篇
  1988年   3102篇
  1987年   3025篇
  1986年   2918篇
  1985年   2725篇
  1984年   2024篇
  1983年   1660篇
  1982年   966篇
  1981年   958篇
  1979年   1893篇
  1978年   1407篇
  1977年   1151篇
  1976年   979篇
  1975年   1211篇
  1974年   1272篇
  1973年   1266篇
  1972年   1091篇
  1971年   1025篇
  1970年   925篇
  1969年   830篇
  1968年   805篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
Sticky platelet syndrome (SPS) leads to hyperaggregabilty of platelets in response to physiologic stimuli. In this report we describe three patients with clinical symptoms of SPS after renal transplantation. The first patient developed an infarction of her transplant kidney with additional, subsequent renal microinfarctions. The second patient suffered multiple strokes and deep vein thrombosis with episodes of pulmonary embolism and ischemic bowel disease due to colonic microinfarctions. The third patient experienced a long episode of unexplained respiratory and graft dysfunction immediately after transplantation until therapy for SPS was initiated, at which point symptoms resolved quickly. Kidney transplant recipients with SPS may be at increased risk of developing thrombosis, given that most immunosuppressive drugs are known to induce either endothelial cell damage or augment platelet aggregation. All patients awaiting renal transplantation should be screened for a history of thrombosis and, if appropriate, tested for SPS. Affected patients should receive dose-adjusted acetylsalicylic acid.  相似文献   
84.
85.
Presented in this work is a rare injury of a blunt abdominal trauma in a child. Besides a partial rupture of the kidney and a retro-/intraperitoneal haematoma, a further injury occurred from the accident: an initially clinically indetectable tear of the A. iliaca communis which was found intraoperatively and with systematic CT analysis. Traumatic blood vessel lesions of the abdominal aorta and in particular the iliac blood vessels are very rare in children. By such violent impact injuries, it is therefore vital to perform a clinical examination of the foot pulse, systematic analysis of radiology diagnostics, and intraoperative exploration. The growth phase should be considered for therapy of the blood vessels depending on the child's age group. As the long-term results of graft implants are practically unknown, if possible a primary suture or vein patch should be performed.  相似文献   
86.
87.
By oxygen concentration measurements (Oximeter Oxydig Dräger, Lübeck) in the EC 145 helicopter two oxygen transport and application systems were compared. The new liquid oxygen system (LOX) for the oxygen therapy was assessed in an application observation. For physical reasons fluid oxygen evaporates during the stand-by phase and an increased concentration (22.8% O2) in the exhaust valve of LOX arises. On the other hand a high oxygen concentration (22.7% O2) was measured in the operation mode of the conventional pressure flask gas system (GAS). No increased concentration could be measured within the helicopter cabin (HEMS, PAX) comparing both oxygen systems. For transport and application of oxygen with a very big reserve for the air dependent intensive transport the results show that LOX is a sure low pressure system (3.4 bar).  相似文献   
88.
Objective To describe the clinical presentation of acute diverticulitis in an emergency department and to characterize the natural history of diverticulitis in the short perspective. Comparisons are made with an important differential diagnosis, nonspecific abdominal pain (NSAP). Method Patients admitted to our hospital with abdominal pain of up to 7 days’ duration were registered prospectively using a detailed schedule for history, symptoms and signs, from 1 February 1997 to 1 June 2000. Of 3349 patients initially included, 3073 (92%) were eligible for follow up after 1–3 years. Results Acute diverticulitis was the final diagnosis in 145 patients and NSAP in 1142 patients. The incidence of hospitalized patients with diverticulitis was 47 per year and 100 000 population, with a mean hospital stay of 3.3 days. Patients with diverticulitis, more frequently than NSAP, had a longer history and laboratory signs of inflammatory activity. Isolated left abdominal tenderness was more common in diverticulitis, whereas isolated right abdominal tenderness was more common in NSAP. Duration of symptoms on arrival was independent of age and was not correlated to C‐reactive protein, leucocytes or body temperature. Sensitivity of diverticulitis as primary diagnosis was 64% and specificity 97%. Corresponding figures for NSAP were 43% and 90% respectively. Age and gender did not influence diagnostic accuracy or risk of surgery. Conclusion Diverticulitis differs significantly from NSAP in clinical presentation and laboratory parameters. Sensitivity of primary diagnosis for diverticulitis and NSAP was low.  相似文献   
89.
BACKGROUND: Fractures of the mandible are a common form of facial injury. The aetiological factors associated with mandibular fractures and the trends in these factors over a 10-year period are reported. METHODS: A retrospective survey was carried out of 724 patients presenting with a fracture of the mandible over the 10-year-period 1994-2003. Patients; records were reviewed and analyzed according to age, sex, cause of injury, anatomic site of fracture, treatment and postoperative complications. RESULTS: Over the 10-year-period the rate of mandibular fractures remained constant (mean 40,7%). There were no changes in the age group (mean 33,3 years) or in the higher prevalence in male (male-female-ratio 2,3 : 1). The major causes of fractures were assaults (38,6%) and accidental fall (27,3%). The most common fracture site was the condylar region (47,0%) followed by the angle (29,4%). Most fractures were treated by closed reduction until 2002, thereafter surgical treatment increased noticeable. The complication rate was 8,9% and the most common complications were hardware exposure and infection. CONCLUSION: Fractures of the mandible are a prevalent form of facial injury. Aetiological factors show no significant change over the 10-year-period. Complication-rate is low and will support the tendency towards surgical treatment.  相似文献   
90.
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