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   34933篇
  免费   1663篇
  国内免费   138篇
耳鼻咽喉   483篇
儿科学   648篇
妇产科学   402篇
基础医学   4343篇
口腔科学   1125篇
临床医学   2421篇
内科学   7794篇
皮肤病学   757篇
神经病学   3310篇
特种医学   1808篇
外国民族医学   1篇
外科学   5406篇
综合类   124篇
一般理论   6篇
预防医学   1112篇
眼科学   746篇
药学   2252篇
中国医学   69篇
肿瘤学   3927篇
  2023年   180篇
  2022年   323篇
  2021年   577篇
  2020年   337篇
  2019年   428篇
  2018年   555篇
  2017年   472篇
  2016年   599篇
  2015年   565篇
  2014年   745篇
  2013年   918篇
  2012年   1509篇
  2011年   1540篇
  2010年   944篇
  2009年   799篇
  2008年   1396篇
  2007年   1634篇
  2006年   1505篇
  2005年   1442篇
  2004年   1465篇
  2003年   1379篇
  2002年   1424篇
  2001年   1307篇
  2000年   1416篇
  1999年   1267篇
  1998年   464篇
  1997年   381篇
  1996年   360篇
  1995年   303篇
  1994年   302篇
  1993年   281篇
  1992年   990篇
  1991年   848篇
  1990年   816篇
  1989年   804篇
  1988年   761篇
  1987年   758篇
  1986年   667篇
  1985年   622篇
  1984年   423篇
  1983年   345篇
  1979年   296篇
  1978年   198篇
  1977年   177篇
  1974年   189篇
  1973年   163篇
  1972年   162篇
  1971年   181篇
  1970年   155篇
  1969年   176篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
A 75-year-old man had been admitted to another hospital because of left abdominal pain, and was given a diagnosis of left hydronephrosis and acute pancreatitis. After a JJ stent insertion and medication, he was transferred to our hospital for further examinations. US and EUS revealed a chronic pancreatitis-like pattern and multicystic lesion in the pancreas head and body. At that time enhanced CT findings showed an extrapancreatic low density area to be inflammatory change, extending from the pancreas body to the left crus of the diaphragm and posteriorly the spreading from the left crus of the diaphragm via the left urinary duct into the left iliopsoas muscle, in which MRI revealed partial high intensity. ERCP and MRCP showed focal irregular narrowing of the pancreatic duct of unknown cause, and we decided that an internal pancreatic fistula due to pancreatitis had induced left ureteral obstruction, caused by a protein plug or alcohol. Follow-up 6 months later showed that extrapancreatic spreading of the low density area had markedly regressed without any change in the ureteral obstruction.  相似文献   
14.
15.
16.
The effect of external gamma-irradiation on the digestive function of rat alveolar macrophages (AM) was studied by using the in vitro assay system, where the 59Fe release from AM engulfing 59Fe-iron hydroxide colloid was measured as an indicator of their digestive capability. Graded doses of gamma-irradiation up to 100 Gy had no effect on the extracellular release of 59Fe in AM cultured at 4 and 37 degrees C for 8-72 hrs postirradiation. When 10 mM Ca-DTPA was added to the culture medium, the 59Fe release was slightly depressed by irradiation at a dose of 30 Gy. It is apparent from these results that gamma-irradiation had no effect on the 59Fe transfer between cell and medium, and little effect on the catabolism of 59Fe-colloid in rat AM.  相似文献   
17.
Para-aortic lymph nodes (n4), were dissected out to the technical extreme (superextensive lymph node dissection) from 129 gastric cancer cases, and were subjected to the histological study for metastasis. Following observations led us to the conclusions in reference to the significance of n4 node dissections on curability of surgery. 1) Among 25 cases with n4(+) metastasis n3 was free [n3(-)] in 11 cases (44.0%). 2) ps(+) cancer presented high rate of n4(+) (31.5%). 3) n4(+) occurred irrespective of the location of the cancer, with particularly high rate of occurrence among CMA and cancers. 4) The rate of the metastasized lymph nodes to the total number of the n4 lymph nodes, was found low (34.9%) in cases with n3(-), and high (90.1%) with n3(+). 5) The cumulative survival rate of the cases with n4(+) was found significantly high with n3(-), as compared to n3(+) cases. The lymphatic drainage from the stomach seems more direct and/or more abundant to the n4 than to the n3 nodes. Such observation coincides with our experience that the n4 nodes are involved in metastasis in earlier timing and in higher incidence than n3 nodes. These results warn the present evaluation of curability in which the n4 node dissection is not performed. It is our opinion that the thorough dissection extended to the n4 nodes (superextensive lymph node dissection) is warranted, particularly in order to improve the curability of n3(-)-n4(+) cases.  相似文献   
18.
T Tsuzuki  M Ueda  S Kuramochi  S Iida  S Takahashi  H Iri 《Surgery》1990,108(3):495-501
Carcinoma of the main hepatic duct junction tends to spread extensively along the hepatic ducts into the liver parenchyma. Therefore extensive resection of the bile ducts combined with hepatic resection is the procedure of choice. Between January 1973 and April 1989, 25 of 50 patients with this type of carcinoma underwent resection, a resectability rate of 50%. One patient died of staphylococcal sepsis on the postoperative day 42 after right trisegmentectomy and resection of the bile ducts, a hospital death rate of 4%. Twenty-four patients were discharged from the hospital. The 5-year actuarial survival rate calculated by the Kaplan-Meier method was 19%. Four patients lived longer than 5 years after surgery; the longest survival was 9 years after right trisegmentectomy and resection of the bile ducts. These four patients had clear margins at the resected bile ducts. This article was designed to clarify the point at issue by presenting our results in terms of indications, operative morbidity and mortality, and long-term survival.  相似文献   
19.
For the diagnosis and evaluation of the therapy for male infertility and for predicting the outcome of AIH and IVF-ET, technically simple, replicable tests that can be performed virtually anywhere and that have definite reliability are required. The results of the HOS test correlate well with the functions of the sperm cell membrane, indicating such aspects as motility, and it is thought to be a particularly effective test of human sperm fertility. Because the HOS test reflects the functions and integrity of the sperm cell membrane, it should be possible to use it to predict the potential for fertilization of frozen sperm.  相似文献   
20.
High-performance liquid chromatography has been used to quantitate benzalkonium chloride (alkylbenzyldimethylammonium chloride) in complex ophthalmic formulations at or below concentration levels of 50 ppm. The method involves a one-step dilution for sample preparation and direct injection; therefore, recovery and/or conversion problems are nonexistent. The assay is quick, specific, reproducible, and simple. This new approach makes routine determinations far simpler than previous methods and is especially useful for product stability studies and quality control procedures.  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