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   1037篇
  免费   44篇
  国内免费   3篇
耳鼻咽喉   2篇
儿科学   36篇
妇产科学   31篇
基础医学   110篇
口腔科学   4篇
临床医学   68篇
内科学   124篇
皮肤病学   60篇
神经病学   95篇
特种医学   39篇
外科学   258篇
综合类   9篇
预防医学   78篇
眼科学   42篇
药学   62篇
中国医学   3篇
肿瘤学   63篇
  2022年   7篇
  2021年   10篇
  2019年   10篇
  2018年   8篇
  2017年   9篇
  2016年   21篇
  2015年   19篇
  2014年   25篇
  2013年   26篇
  2012年   26篇
  2011年   31篇
  2010年   32篇
  2009年   27篇
  2008年   39篇
  2007年   36篇
  2006年   37篇
  2005年   53篇
  2004年   40篇
  2003年   45篇
  2002年   69篇
  2001年   34篇
  2000年   37篇
  1999年   38篇
  1998年   11篇
  1997年   6篇
  1996年   8篇
  1995年   11篇
  1994年   13篇
  1993年   7篇
  1992年   16篇
  1991年   17篇
  1990年   23篇
  1989年   16篇
  1988年   22篇
  1987年   17篇
  1986年   15篇
  1985年   15篇
  1984年   10篇
  1983年   10篇
  1981年   11篇
  1979年   16篇
  1978年   11篇
  1975年   7篇
  1974年   9篇
  1973年   8篇
  1970年   14篇
  1967年   9篇
  1939年   6篇
  1934年   5篇
  1930年   7篇
排序方式: 共有1084条查询结果,搜索用时 15 毫秒
1.
2.
3.
The clinicopathologic features of osteosarcoma in 12 children younger than 16 years of age treated at The Children's Hospital and Dana-Farber Cancer Institute, Boston, during a 70-year time period are presented. Only one of six children treated before 1972 is a long-term survivor. Four of six children (67%) treated after 1972 are disease-free with an average follow-up of 8.8 years. The year 1972 marked the onset of use of effective chemotherapy in osteosarcoma, namely, high-dose methotrexate and leucovorin rescue. It would appear that the pathologic features and behavior of osteosarcoma in young children is similar to that of osteosarcoma in older children and adolescents. A combination of complete (wide) surgical resection or amputation and aggressive chemotherapy offers the best chance of long-term survival.  相似文献   
4.
5.
Experimental studies demonstrated a severe cardiac load of the CO2 pneumoperitoneum caused by an accelerated after- and a decreased preload. Patients displaying cardiovascular risks are therefore often rejected from laparoscopic surgery. Hence, the pathophysiological changes and the intraoperative risk of the CO2 pneumoperitoneum in high-risk cardiopulmonary patients (NYHA II–III, n= 15) undergoing laparoscopic cholecystectomy are described. The changes in cardiac after- and preload seem to be due to the elevated intraabdominal pressure rather than transperitoneally resorbed CO2 and are reversible by desufflation. In one patient conversion to open operation had to be performed because of a severe drop in cardiac output and right ventricle ejection fraction. Mixed oxygen saturation was predicting intraoperative worsening in this case. The described pathophysiological changes may seem to be well tolerated even in high-risk cardiac patients. Monitoring of hemodynamics should include an arterial catheter line and blood gas analyses. Pharmacologic interventions or pressureless laparoscopic procedures might not be necessary as long as laparoscopic cholecystectomy is performed. Received: 13 December 1996/Accepted: 8 January 1997  相似文献   
6.
In contrast to conventional film angiography, the perfusion pattern of hepatic arterial chemotherapy was consistently visualized by DSA in 40 patients with implanted Infusaid pump or Port-A devices. Incomplete perfusion of a liver region by the cytotoxic agent was recognized by DSA as accurately as by nuclide scintigraphy. Furthermore, DSA appeared to be more sensitive in determining aberrantly perfused extrahepatic regions; this was especially true when there was a nonligated right hepatic artery. Specific details of vascular lesions and associated complicating events also could be satisfactorily analyzed by DSA only.  相似文献   
7.
We present a new concept after Schultheis which is based on the results of experimental studies on cell cultures. Local chemoembolization in liver tumours including liver metastases is usually performed via the angiographic route. Embolisation of the most peripheral branches of the hepatic artery prevents early formation of collateral vessels. The method also comprises the additional infusion of cytostatic agents via the portal vein. The procedure is usually repeated after an interval of about four weeks. In this paper we will describe our method in liver metastases and present the preliminary results obtained from 19 patients treated to date.  相似文献   
8.
With regard to disturbances of the iron metabolism, porphyria cutanea tarda (PCT) is most frequently accompanied by liver siderosis. In 74 out of 88 patients suffering from PCT (84%), we found histochemical evidence of liver siderosis. These patients showed a significantly higher incidence of HLA A3--which has been proved to be associated with hemochromatosis--than those without liver siderosis (39.2% vs. 7.1%). With part of the PCT patients, disorders of the iron metabolism related to the HLA system (A3) might contribute to the manifestation of the disease. We discuss PCT as the result of the combined action of several predisposing genetic markers and exogenic factors.  相似文献   
9.
In a prospectively randomized study we used two different ways of drainage of the sacral space after an abdomino-perineal-resection of the rectum. One group with 25 patients had a drainage anteriorly through the abdominal wall, the other 25 patients got a drainage posteriorly through the buttocks. In each case we used two closed silicone-drainage-systems without active suction. In 60% of the anterior and in 50% of the posterior drained cases we saw an unaffected primary healing of the sacral wound. There was no significant difference. The patients felt the anterior way of drainage to be more convenient. Contamination of the sacral space by disrupture of the rectum during the operation was followed by a sacral abscess in 50%.  相似文献   
10.
A 19-year-old woman presented with a large mediastinal mass, histologically shown to be malignant lymphoma of lymphoblastic type (LBL). Immunophenotypic and gene rearrangement analysis unequivocally demonstrated that the neoplasm was of B-cell lineage. The neoplastic cells expressed terminal deoxynucleotidyl transferase, the pan-B cell antigens CD19, CD20, and CD22, and were negative for immunoglobulins and numerous T-cell antigens tested. Southern blot analysis showed rearrangement of one allele of the immunoglobulin heavy chain gene while the immunoglobulin kappa and T-cell receptor beta chain genes were in the germline configuration. Thus, the immunophenotypic and molecular findings in this case correspond to an early stage of B-cell differentiation, the pre-pre B-cell stage as has been named by others. In contrast with LBL of immature T-cell lineage, precursor B-cell LBLs involving the mediastinum are truly rare. Occasional cases have been reported that have arisen elsewhere and subsequently involved the mediastinum at time of relapse or tumor progression. Well-documented examples of immature B-cell LBL arising in the mediastinum are virtually unreported. The site and cell population giving rise to this neoplasm is unknown. However, origin from precursors of normal thymic medullary B cells is proposed as one possibility.  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