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   14235篇
  免费   698篇
  国内免费   69篇
耳鼻咽喉   141篇
儿科学   268篇
妇产科学   163篇
基础医学   1630篇
口腔科学   400篇
临床医学   911篇
内科学   3613篇
皮肤病学   499篇
神经病学   868篇
特种医学   628篇
外科学   2729篇
综合类   77篇
一般理论   2篇
预防医学   425篇
眼科学   135篇
药学   989篇
中国医学   33篇
肿瘤学   1491篇
  2022年   116篇
  2021年   255篇
  2020年   147篇
  2019年   185篇
  2018年   265篇
  2017年   184篇
  2016年   193篇
  2015年   242篇
  2014年   291篇
  2013年   382篇
  2012年   631篇
  2011年   761篇
  2010年   431篇
  2009年   325篇
  2008年   695篇
  2007年   686篇
  2006年   646篇
  2005年   611篇
  2004年   558篇
  2003年   535篇
  2002年   581篇
  2001年   439篇
  2000年   498篇
  1999年   409篇
  1998年   157篇
  1997年   127篇
  1996年   143篇
  1995年   109篇
  1994年   108篇
  1993年   118篇
  1992年   384篇
  1991年   336篇
  1990年   332篇
  1989年   343篇
  1988年   323篇
  1987年   308篇
  1986年   270篇
  1985年   244篇
  1984年   183篇
  1983年   171篇
  1981年   74篇
  1979年   107篇
  1978年   81篇
  1977年   81篇
  1974年   77篇
  1973年   71篇
  1972年   74篇
  1971年   71篇
  1970年   80篇
  1969年   74篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
We investigated the comparative effectiveness of the seat and glue types of fibrin adhesive, to clarify which is more useful in preventing postoperative parenchymal air leaks after lung resection. One hundred sixteen patients received fibrin adhesive to prevent postoperative air leakage after lung resection carried out by the same surgeon. Ninety-two lobectomies and 24 partial resections were assessed. There were 29 patients with emphysematous lung. In the seat type group, an average of 2.6 postoperative days elapsed before chest drain removal. In the glue type, this average was 3.2 days, a significant difference. This difference was also evident in the lobectomy group. However, among emphysematous lung patients and the partial resection group, there was no apparent difference. Prolonged air leakage was seen in 2 patients with emphysematous lung, but no difference in terms of drug formation could be seen. The seated type of fibrin adhesive was more useful than the glue type in preventing postoperative air leaks, but in emphysematous lung patients, better surgical technique would seem to be the critical factor.  相似文献   
992.
A 43-year-old-woman who had sever anterior chest pain visited our hospital on April 3, 2000. A well-defined abnormal shadow was seen in the middle and lower field of the right lung on chest X-ray. Computed tomography showed a large fat density mass in the right pleural cavity with a septum enhanced by contrast medium. Percutaneous needle biopsy revealed lipoma or liposarcoma. Complete resection could be done with combined resection of right lung, lpericardium, parietal pleura and diaphragm. Final histologic diagnosis was well differentiated liposarcoma. There are few reports of liposarcoma arising in the thoracic cavity, we present our case and review the 23 cases reported from the Japanese literatures.  相似文献   
993.
We performed 127 esophageal resections for the esophageal cancer patient from December 1995 to September 2001. It was separated to under 70 years old patients group (group I), 71-74 years old patients group (group II), and over 75 years old patients group (group III). RESULTS: Postoperative complication was occurred in 53 cases (41.7%) within all of 127 esophageal resected cases. It was 33.7% in group I, 53.6% in group II, 62.5% in group III. Four years survival rate of each group is 38.3% in group I, 44.6% in group II, 31.3% in group III. It is significantly better in group II rather than in group III. Operative death rate is 12.5% (2 cases) in group III, 7.1% (2 cases) in group II, 3.6% (3 cases) in group I, and it is gradually higher and higher by patient's age. CONCLUSIONS: (1) In the esophageal cancer patient over 75 years old, postoperative complication rate is higher than under 74 years old patients, and prognosis is significantly poor rather than in 70-74 years old patients group. (2) In the esophageal cancer patient over 75 years old, we considered it is good indication of esophagectomy for stage I and stage II patient without preoperative complication, however, there are no operative indication for stage III and stage IV patient.  相似文献   
994.
The present study is undertaken to determine if ethanol affects 7-hydroperoxycholesterol or oxysterols in rat skeletal muscle after chronic ethanol feeding. Wistar rats were fed a liquid diet containing ethanol as 35% of total calories. After 6 weeks, soleus (Type I fibre-predominant) and plantaris (Type II fibre-predominant) skeletal muscles were dissected out. We measured 7alpha- and 7beta-hydroperoxycholest-5-en-3beta-ol (7alpha-OOH and 7beta-OOH) as well as 7alpha- and 7beta-hydroxycholesterol (7alpha-OH and 7beta-OH) and 3beta-hydroxycholest-5-en-7-one (7-keto). We found that in response to chronic alcohol feeding, there were significant increases in soleus 7alpha-OH (P=0.0005), 7beta-OH (P=0.0005) and 7-keto (P=0.0007), but in the plantaris, 7beta-OH increased (P=0.0418). Their elevation in chronic experimental alcoholism, together with increases in cholesterol hydroperoxides, may possibly represent evidence of increased oxidative stress.  相似文献   
995.
The aim of the present study was to investigate the lung-heart weight ratio in fresh- and saltwater drowning (n=67 and n=75, respectively) as a possible index of cardiopulmonary pathophysiology, in comparison with acute myocardial infarction/ischemia (AMI, n=75) and asphyxiation (n=85). In drowning cases, the total value of the combined lung weight and the amount of pleural effusion was regarded as a possible total lung weight. The median value of the combined/total lung weight was the highest in saltwater drowning, which was followed by freshwater drowning, AMI and asphyxiation, showing a tendency to be mildly increased depending on the heart weight. The lung-heart weight ratio was significantly higher in fresh-/saltwater drownings (3.944+/-1.538 and 4.825+/-2.242, respectively) than in asphyxiation (2.846+/-1.042) and AMI (2.641+/-0.916) (P<0.0001), showing a tendency to be higher in saltwater than freshwater drowning. However, the value depended on the gender and age of the subjects, and the difference between freshwater drowning and asphyxiation was insignificant in females. These results suggested that the lung-heart weight ratio may be an index for investigating the influence of aspirated immersion medium in drownings.  相似文献   
996.
BACKGROUND: The recurrence of autoimmunity and allograft rejection act as major barriers to the widespread use of islet transplantation as a cure for type 1 diabetes. The aim of this study was to evaluate the feasibility of immunoisolation by use of an agarose microcapsule to prevent autoimmune recurrence after islet transplantation. METHODS: Highly purified islets were isolated from 6- to 8-week-old prediabetic male nonobese diabetic (NOD) mice and microencapsulated in 5% agarose hydrogel as a semipermeable membrane. Islet function was evaluated by a syngeneic islet transplantation model, in which islets were transplanted into spontaneously diabetic NOD mice. RESULTS: The nonencapsulated islet grafts were destroyed and diabetes recurred within 2 weeks after transplantation in all 12 mice. In contrast, 13 of the 16 mice that underwent transplantation with microencapsulated islets maintained normoglycemia for more than 100 days after islet transplantation. Histologic examination of the nonencapsulated islet grafts showed massive mononuclear cellular infiltration with beta-cell destruction. In contrast, the microencapsulated islets showed well-granulated beta cells with no mononuclear cellular infiltration around the microcapsules or in the accompanying blood capillaries between the microcapsules. CONCLUSIONS: Agarose microcapsules were able to completely protect NOD islet isografts from autoimmune destruction in the syngeneic islet transplantation model.  相似文献   
997.
We examined the safety and efficacy of the combination of irinotecan plus carboplatin in patients with refractory or relapsed small cell lung cancer (SCLC). Patients with previously treated SCLC were eligible. Patients were treated every 3 weeks with carboplatin (with a target area under the concentration versus time curve of 5 mg min/ml using the Calvert formula on day 1) plus irinotecan (50 mg/m2 on days 1 and 8). From May 2000 to January 2002, 24 patients were eligible. None of the 22 patients achieved a complete response, but 15 achieved a partial response with an overall response rate of 68.2% (95% confidence interval, 45.1–86.1%). In 13 patients with sensitive disease, the response rate was 92.3% (95% confidence interval, 64.0–99.8%). The median survival time (MST) was 194 days (range 27–605 days). The MST did not differ significantly between patients with sensitive disease (245 days) and those with refractory disease (194 days, P=0.88). One patient died of treatment-related sepsis. Grade 3–4 hematologic toxicities included leukopenia in 58% of patients, neutropenia in 63%, thrombocytopenia in 58%, and anemia in 67%. Grade 3 diarrhea developed in 21% of patients and grade 3–4 infection in 13%. No patients had grade 4 diarrhea or grade 3–4 nausea and vomiting. This regimen is effective and well tolerated in patients with relapsed or refractory SCLC. However, the search for even more active regimens should be continued.  相似文献   
998.
999.
A 65-year-old woman with diabetes mellitus was hospitalized for heart failure and anemia in August 2001, and recovered with conservative treatment. An endoscopic examination revealed an ulcerative mass located in the duodenal bulb to the 2nd portion. Abdominal CT scan demonstrated tumor involvement in the pancreas head. The diagnosis of a diffuse large B-cell lymphoma, clinical stage IIE, was made by endoscopic biopsy. Although surgical resection of the localized intestinal tumor would have been a common choice for initial treatment, polychemotherapy was selected; the patient had diabetes mellitus and preferred polychemotherapy to surgical operation. Because of bulky intestinal mass, transmural disease and sensitive histological type, standard-dose chemotherapy was considered to include a high risk of intestinal perforation. We performed dose-escalating chemotherapy: A half dose of THP-COP (pirarubicin, cyclophosphamide, vincristine) was given at the start in October 2001, 60% THP-COP as the next cycle, 80% THP-COP as the 3rd cycle and thereafter. Without serious complications of the intestine, she received a total of 6 cycles of chemotherapy and subsequent involved field radiation. There has been no evidence of recurrence of disease 14 months from the start of chemotherapy. When conditions make surgical treatment difficult, dose-escalating chemotherapy in a treatment cycle may be considered as an alternative.  相似文献   
1000.
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