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   10133篇
  免费   452篇
  国内免费   46篇
耳鼻咽喉   60篇
儿科学   167篇
妇产科学   160篇
基础医学   1354篇
口腔科学   246篇
临床医学   664篇
内科学   2605篇
皮肤病学   158篇
神经病学   611篇
特种医学   391篇
外科学   1640篇
综合类   64篇
预防医学   327篇
眼科学   145篇
药学   761篇
中国医学   62篇
肿瘤学   1216篇
  2023年   49篇
  2022年   100篇
  2021年   198篇
  2020年   102篇
  2019年   138篇
  2018年   165篇
  2017年   127篇
  2016年   160篇
  2015年   169篇
  2014年   218篇
  2013年   270篇
  2012年   500篇
  2011年   558篇
  2010年   307篇
  2009年   280篇
  2008年   457篇
  2007年   548篇
  2006年   553篇
  2005年   627篇
  2004年   580篇
  2003年   589篇
  2002年   587篇
  2001年   236篇
  2000年   253篇
  1999年   279篇
  1998年   145篇
  1997年   160篇
  1996年   139篇
  1995年   111篇
  1994年   72篇
  1993年   81篇
  1992年   162篇
  1991年   140篇
  1990年   164篇
  1989年   147篇
  1988年   140篇
  1987年   127篇
  1986年   150篇
  1985年   98篇
  1984年   102篇
  1983年   77篇
  1982年   34篇
  1981年   37篇
  1979年   63篇
  1978年   38篇
  1977年   34篇
  1975年   34篇
  1974年   33篇
  1971年   37篇
  1970年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
The purpose of this study was to characterize the chemical interaction between titanium surfaces and the peptide RGDS(PO(3)H(2))PA (P-RGD) synthesized from RGD peptide (RGD) and o-phospho-L-serine (P-Ser), and to determine the degree of peptide immobilization on the titanium surface. X-ray photoelectron spectroscopy showed that the adsorption amount of RGD was significantly smaller than those of P-Ser and P-RGD (p<0.05). Furthermore, although it appeared that P-RGD bonded to the surface, ultrasonic rinsing with water caused it to dissociate, releasing RGD and leaving only S(PO(3)H(2))PA bonded to the surface. These findings show that although it remains difficult to obtain a stable P-RGD layer, the phosphate functional group greatly improves immobilization of the molecule on titanium surfaces.  相似文献   
993.
994.
995.
Aims:  The objective of the present study was to identify schizophrenia inpatients who had their original regimen augmented with additional antipsychotics during acute inpatient care, and to clarify the factors associated with these additions.
Methods:  The subjects were 204 schizophrenia inpatients at 34 acute care hospitals, of whom 42 (20.6%) had further antipsychotics added to their medication regimen during hospitalization.
Results:  Compared with patients who were not prescribed additional antipsychotics, the subjects were typically discharged with higher dosages of antipsychotics, principally low-potency medications. Patients who exhibited aggressive behavior, who had no physical illness, or whose psychiatrists preferred typical antipsychotics, were more likely to be prescribed additional new antipsychotics.
Conclusions:  Alternative approaches such as intensive care for aggressive patients and educational intervention with psychiatrists may prove useful in stabilizing patients without adding new antipsychotics unless absolutely necessary, and in simplifying medication regimens.  相似文献   
996.
997.
Background  Laparoscopic wedge resection (LWR) can be applied for the management of early gastric cancer without the risk of lymph node metastasis. Although LWR for early gastric cancer is one of the minimally invasive procedures, its radicality in cancer therapy is controversial. This study aimed to evaluate the long-term outcomes after LWR. Methods  Data on 43 consecutive cases of LWR performed for preoperatively diagnosed mucosal gastric cancer were analyzed retrospectively in terms of long-term outcomes. Results  No postoperative deaths occurred after LWR. Histologically, resected specimens showed submucosal invasion in 11 cases (26%) and positive surgical margins for cancer in 4 cases (9%). Three patients (7%) showed local recurrence near the staple line, and one patient (2%) died due to the local recurrence, but no lesional lymph node or distant recurrence occurred. The overall 5-year survival rate was 88%. The gastric remnant after LWR developed metachronous multiple gastric cancer in five cases (12%). Conclusions  The findings show a relatively high incidence of positive surgical margin, local recurrence, and gastric remnant cancer after LWR. Although LWR can be performed for properly selected patients, periodic postoperative endoscopic examination is necessary to detect metachronous multiple gastric cancer and local recurrences.  相似文献   
998.
In two previous randomized controlled trials we showed that treatment of severe childhood immunoglobulin A nephropathy (IgA-N) using prednisolone, azathioprine, heparin–warfarin, and dipyridamole prevented any increase of sclerosed glomeruli and that prednisolone alone did not prevent a further increase of sclerosed glomeruli. Accordingly, the immunosuppressant is considered to be important. Often, however, we were unable to complete azathioprine regimen due to toxicity. Therefore, a different but effective immunosuppressant may be worth trying. Mizoribine, like azathioprine, is an antimetabolite that exerts its immunosuppressant effect by inhibiting lymphocyte proliferation. In this pilot study, we administered mizoribine instead of azathioprine as part of the combination therapy for treating 23 children with severe IgA-N and evaluated the efficacy and safety. Eighteen patients reached the primary endpoint (urine protein/creatinine ratio <0.2) during the 2-year treatment period. The cumulative disappearance rate of proteinuria determined by Kaplan–Meier was 80.4%. Median protein excretion was reduced from 1.19 g/m2/day to 0.05 g/m2/day (p < 0.0001). After treatment, the median percentage of glomeruli showing sclerosis was unchanged in comparison with that before treatment. No patients required a change of treatment. In conclusion, the efficacy and safety of the mizoribine combination seems to be acceptable for treating children with severe IgA-N. *Participants listed at end of paper.  相似文献   
999.
A lymphoepithelial cyst (LEC) is an extremely rare benign lesion of the pancreas. During a medical check-up, a 77-year-old man without any symptoms was found to have a cyst in the body of the pancreas. His serum carbohydrate antigen 19-9 level was slightly elevated. Computed tomography showed a multilocular, low-attenuating cyst on the superior surface of the pancreatic body. Thus, we performed distal pancreatectomy with splenectomy. Histological examination revealed that the cyst wall was lined with squamous epithelium and surrounded by abundant mature lymphoid tissue. Keratinous substances were present in the cyst. An LEC of the pancreas is associated with a good prognosis and, although unusual, it should be considered in the differential diagnosis of pancreatic cystic lesions. Minimal resection of the cyst should be performed whenever possible, and extensive surgery avoided. For patients with a high surgical risk, fine-needle aspiration biopsy may be considered.  相似文献   
1000.
A lobectomy with a resection of the pulmonary artery is less invasive than a pneumonectomy. However, it seems to be extremely difficult to perform this technique using video-assisted thoracic surgery with technical limitations because this technique is associated with an increased operative risk even in an open thoracotomy. Between April 2002 and December 2006, a curative video-assisted thoracic surgery lobectomy including a mediastinal lymphadenectomy was performed in 121 patients with primary non-small cell lung cancer. Five of those patients underwent a thoracoscopic lobectomy with the partial removal and reconstruction of the pulmonary artery. The causes of the pulmonary artery resection included two direct invasions of the artery, two invasions of the arterial branch, and one calcified lymphadenopathy involving the branch. No patients required a blood transfusion. No complications attributable to the technique or mortality were seen. No patients showed an abnormal blood flow through the reconstructed vessel. There were no local recurrences on the pulmonary artery. A video-assisted thoracic surgery lobectomy including a partial resection and reconstruction of the pulmonary artery is a complex procedure for patients with non-small cell lung cancer. It is feasible when all associated technical issues are properly addressed.  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