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   1419篇
  免费   45篇
  国内免费   6篇
耳鼻咽喉   10篇
儿科学   11篇
妇产科学   6篇
基础医学   113篇
口腔科学   17篇
临床医学   102篇
内科学   471篇
皮肤病学   3篇
神经病学   40篇
特种医学   91篇
外科学   295篇
综合类   3篇
预防医学   28篇
眼科学   33篇
药学   90篇
中国医学   3篇
肿瘤学   154篇
  2023年   12篇
  2022年   14篇
  2021年   21篇
  2020年   16篇
  2019年   11篇
  2018年   24篇
  2017年   14篇
  2016年   29篇
  2015年   24篇
  2014年   24篇
  2013年   33篇
  2012年   54篇
  2011年   62篇
  2010年   36篇
  2009年   33篇
  2008年   52篇
  2007年   77篇
  2006年   65篇
  2005年   58篇
  2004年   70篇
  2003年   65篇
  2002年   72篇
  2001年   78篇
  2000年   66篇
  1999年   65篇
  1998年   29篇
  1997年   19篇
  1996年   7篇
  1995年   16篇
  1994年   14篇
  1993年   6篇
  1992年   40篇
  1991年   25篇
  1990年   27篇
  1989年   28篇
  1988年   26篇
  1987年   17篇
  1986年   23篇
  1985年   14篇
  1984年   14篇
  1983年   10篇
  1981年   5篇
  1980年   9篇
  1979年   8篇
  1978年   6篇
  1971年   5篇
  1970年   6篇
  1969年   5篇
  1967年   7篇
  1966年   6篇
排序方式: 共有1470条查询结果,搜索用时 0 毫秒
51.
52.
BACKGROUND: It is not clear that hepatic venous backflow actually contributes to hepatic tissue oxygenation under inflow occlusion of the liver. In order to prove that substances delivered via the hepatic vein can be utilized and/or metabolized in hepatocytes during inflow occlusion, hepatic uptake in bile and excretion of indocyanine green (ICG) were investigated in pigs. MATERIALS AND METHODS: Animals were divided into two groups: an inflow occlusion (IO) group (N = 6) and a total hepatic vascular exclusion (THVE) group (N = 3) using a bypass. One milligram of ICG per kilogram body weight was administered at the beginning of blood flow occlusion, the retention rate in the blood (ICG R) measured, and the ICG in the hepatic tissue measured by near-infrared (NIR) spectroscopy. Furthermore, the ICG concentration was measured in bile excreted by intermittent perfusion of the liver. RESULTS: ICG R declined with time in both groups; however, ICG R in the IO group decreased much faster than in the THVE group. There were significant differences between the two groups after 30 min of occlusion (P < 0.05). ICG in the hepatic tissue could be detected as a peak at 805 nm 10 min after ICG injection, and the peak became steeper with time. On the other hand, ICG was not detected at all in the hepatic tissue after 180 min in the THVE group. ICG was excreted in the bile after 60 min under IO and increased with time. On the contrary, ICG was not excreted in the bile at all under THVE. There were significant differences between the two groups after 90 min (P < 0.05). CONCLUSION: These results indicate that ICG can be extracted in hepatocytes and excreted in bile under IO of the liver. Consequently, substances such as oxygen and drugs, which are delivered via the hepatic vein, can be utilized and/or metabolized in hepatocytes under IO.  相似文献   
53.
54.
To investigate whether the use of a stentless porcine aortic xenograft can be an alternative for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure, 9 patients underwent the Ross procedure and RVOT reconstruction with a stentless xenograft since January 2000. After the aortic valve was replaced with a pulmonary autograft, a stentless xenograft with a xeno- pericardial roll was implanted in the RVOT. One patient required subsequent aortic valve replacement because of severe regurgitation of the pulmonary autograft. All patients recovered well from the operation. The right ventricle-pulmonary arterial pressure gradient was 18 +/- 7 mm Hg at discharge and was not significantly increased during the 2-year follow-up period. Although 1 patient died of ventricular arrhythmia 5 months after, his cardiac function was normal, and transpulmonary valve pressure was 19 mm Hg in the follow-up. The other 7 patients are currently in New York Heart Association functional Class I. Although long-term follow-up is required to explain the durability, the stentless xenograft with a pericardial roll is considered to be an alternative for reconstruction of the RVOT within 2 years after the Ross procedure.  相似文献   
55.
We herein describe the MRI findings in a patient clinically diagnosed with primary Sj?gren's syndrome (SjS) initially manifested by retrobulbar optic neuritis. A 63-year-old woman suddenly had left ocular pain and progressive visual disturbance. MR T2-weighted images revealed hyperintensity in the left optic nerve, with swelling. Contrast-enhanced T1-weighted images showed no abnormal enhancement. Follow-up MRI 6 months after admission revealed no significant changes in the affected optic nerve. To our knowledge, optic neuritis as a complication of SjS has been reported in ten patients [1, 2, 3, 4, 5, 6] and MRI findings in only one of them [6]. We thought MR images were useful for visualizing optic nerve involvement in SjS and observing its course.  相似文献   
56.
57.
BACKGROUND: Whole-body 2-fluoro-2-D-[18F]deoxyglucose [FDG] positron emission tomography (WB-PET) may be more cost-effective than chest PET because WB-PET does not require conventional imaging (CI) for extrathoracic staging. METHODS: The cost-effectiveness of WB-PET for the management of Japanese patients with non-small-cell lung carcinoma (NSCLC) was assessed. Decision-tree sensitivity analysis was designed, based on the two competing strategies of WB-PET vs. CI. WB-PET was assumed to have a sensitivity and specificity for detecting metastases, of 90% to 100% and CI of 80% to 90%. The prevalences of M1 disease were 34% and 20%. One thousand patients suspected of having NSCLC were simulated in each strategy. We surveyed the relevant literature for the choice of variables. Expected cost saving (CS) and expected life expectancy (LE) for NSCLC patients were calculated. RESULTS: The WB-PET strategy yielded an expected CS of $951 US to $1,493US per patient and an expected LE of minus 0.0246 years to minus 0.0136 years per patient for the 71.4% NSCLC and 34% M1 disease prevalence at our hospital. PET avoided unnecessary bronchoscopies and thoracotomies for incurable and benign diseases. Overall, the CS for each patient was $833US to $2,010US at NSCLC prevalences ranging from 10% to 90%. The LE of the WB-PET strategy was similar to that of the CI strategy. The CS and LE minimally varied in the two situations of 34% and 20% M1 disease prevalence. CONCLUSIONS: The introduction of a WB-PET strategy in place of CI for managing NSCLC patients is potentially cost-effective in Japan.  相似文献   
58.
A case of pancreatic involvement by non-Hodgkin's lymphoma is presented. The patient, a 63-year-old man had a large tumor in the head of the pancreas, without obstructive jaundice. Invasion of the tumor into the duodenum and transverse colon induced progressive anemia and ileus. Therefore, pancreatoduodenectomy and right hemicolectomy were performed, although a definitive preoperative diagnosis was not obtained. This tumor was identified, by histopathology and immunohistochemistry, as diffuse mixed type lymphoma with a B-cell phenotype. Postoperatively, the patient had severe congestive heart failure, and he died without receiving chemotherapy. It is important to establish a definitive diagnosis for this disease, to remove the tumor, and to treat the patient with appropriate chemotherapy. Received: July 14, 2000 / Accepted: September 12, 2000  相似文献   
59.
The effects of the aromatase inhibitor, CGS16949A, and the fluoropyrimidine, 5-fluorouracil (5-FU), on cell cycle distribution and growth were studied using FACS analysis and MTT assay in the human breast cancer cell line, SK-BR-3. CGS16949A induced an increase in the G0-G1 fraction on SK-BR-3 cells, and the growth inhibition rate of the combination of both (65.7 +/- 3.0%) was significantly higher than 10 nM CGS16949A (37.9 +/- 6.9%) or 100 microg/ml 5-FU (45.6 +/- 4.5%); p < 0.01). Administering 5-FU after preincubation with CGS16949A significantly increased the combined cytotoxic efficacy, suggesting that clinical therapy using this combined therapy may be more efficient.  相似文献   
60.
Background: Endoscopic laryngo-pharyngeal surgery (ELPS), which is a transoral minimally invasive surgery using a gastrointestinal endoscope and a curved laryngopharyngeal retractor, is effective to treat primary lesions of superficial laryngopharyngeal cancers. To extend concepts of ELPS to invasive laryngopharyngeal cancers, we developed end-flexible-rigidscopic transoral surgery (E-TOS) from ELPS by changing a gastrointestinal endoscope to a flexible-tip rigid endoscope.

Aims/Objectives: To retrospectively evaluate oncological outcomes and laryngopharyngeal functional preservation of E-TOS in patients with T1-selected T3 laryngopharyngeal cancers.

Material and methods: In 47 patients T1-selected T3 pharyngeal and supraglottic cancers were resected by E-TOS using the flexible-tip rigid endoscope and curved instruments. Negative resection margin was histopathologically evaluated. The survival, preservation of larynx, and disease control rates were estimated using Kaplan-Meier method.

Results: Curative resection was achieved in 94% of patients. No patient complained prolonged swallowing dysfunction or hoarseness after E-TOS. Postoperative bleeding, stenosis of the pharynx and esophageal entrance, and local recurrence was observed each in one patient. The 3-year overall survival, disease-specific survival, laryngeal preservation, local control, and locoregional control rates were, 86%, 93%, 100%, 98%, and 79%, respectively.

Conclusion: E-TOS is an effective minimally invasive surgery for T1-selected T3 pharyngeal and supraglottic cancers with preserving laryngeal function.  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