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   7533篇
  免费   599篇
  国内免费   250篇
耳鼻咽喉   192篇
儿科学   255篇
妇产科学   170篇
基础医学   642篇
口腔科学   184篇
临床医学   763篇
内科学   1510篇
皮肤病学   167篇
神经病学   276篇
特种医学   261篇
外科学   1280篇
综合类   795篇
一般理论   1篇
预防医学   381篇
眼科学   220篇
药学   596篇
  2篇
中国医学   315篇
肿瘤学   372篇
  2024年   41篇
  2023年   119篇
  2022年   261篇
  2021年   361篇
  2020年   271篇
  2019年   213篇
  2018年   246篇
  2017年   267篇
  2016年   261篇
  2015年   327篇
  2014年   412篇
  2013年   471篇
  2012年   635篇
  2011年   563篇
  2010年   387篇
  2009年   355篇
  2008年   506篇
  2007年   497篇
  2006年   417篇
  2005年   395篇
  2004年   311篇
  2003年   314篇
  2002年   246篇
  2001年   116篇
  2000年   96篇
  1999年   56篇
  1998年   33篇
  1997年   31篇
  1996年   26篇
  1995年   26篇
  1994年   23篇
  1993年   17篇
  1992年   9篇
  1991年   13篇
  1990年   9篇
  1989年   4篇
  1988年   5篇
  1987年   7篇
  1986年   3篇
  1985年   6篇
  1984年   7篇
  1983年   2篇
  1982年   5篇
  1980年   2篇
  1971年   2篇
  1968年   1篇
  1966年   1篇
  1965年   2篇
  1957年   1篇
  1943年   1篇
排序方式: 共有8382条查询结果,搜索用时 15 毫秒
91.
网状镍钛合金内支架植入治疗高危前列腺增生症尿潴留   总被引:2,自引:0,他引:2  
目的初步探讨尿道金属内支架植入术治疗高危前列腺增生症(BPH)尿潴留的疗效。方法对56例高危BPH尿潴留患者采用网状镍钛合金支架进行尿道内支架植入术进行治疗。术后随访6~30个月。结果56例患者全部一次植入成功;54例立即自行排尿,另2例留置导尿管3天后自行排尿。术前测定IPSS平均为(26±4.2)分,RUV为(148±13.5)ml;术后随访期间IPSS平均(7.3±2.7)分,RUV为(58.4±16.7)ml(P〈0.01)。结论网状镍钛合金内支架植入术是高危前列腺增生症(BPH)尿潴留的有效治疗方法。  相似文献   
92.
Background The value of re-exploration for pancreatic ductal adenocarcinoma after the initial diagnosis of unresectability is unclear. Methods In this study, we analyzed 33 patients who were re-explored after an initial diagnosis of unresectability. Results At the time of reoperation, a resectable tumor was found in 18 patients: therefore, 15 pancreaticoduodenectomies, two total pancreatectomies and one left resection were performed with three vascular resections. Morbidity and mortality rates for the cohort were 6/33 and 1/33, without significant differences between resectable and nonresectable patients. Length of stay, duration of operation, and blood loss were significantly increased in the resection group. Kaplan–Meier survival analysis demonstrated increased median survival for resected patients (1078 days after the initial operation versus 547 days in the group of unresectable patients; p = 0.018). Analysis of the reasons against initial resection showed that, if the patients had been sent to a tertiary referral center for pancreatic surgery, a different decision in favor of resection would probably have been made in 14 out of 33 patients. A review of 10 published reports on reoperation for pancreatic cancer revealed results comparable to our study in terms of low morbidity and mortality as well as a survival benefit. Conclusions Reoperation for pancreatic ductal adenocarcinoma that is initially deemed unresectable can be safely performed in a selected group of patients by experienced surgeons, supporting the concept of patient centralization in pancreatic surgery. Resection at the second operation may confer a survival benefit even when the initial findings preclude a potentially curative approach.  相似文献   
93.
Anomalies of pulmonary veins are uncommon and vary widely in their anatomic spectrum and clinical presentation. A 20-year-old woman with complaints of effort-induced dyspnea and easy fatigability was diagnosed with a third left pulmonary vein with abnormal return and arteriovenous fistula accompanied by a secundum atrial septal defect (ASD). Complete surgical repair was performed by ASD closure with a pericardial patch and triple ligation of the left vertical vein and associated third pulmonary vein. The patient was discharged on the seventh postoperative day in good health. Her last control examination was performed in the second postoperative year, revealing normal echocardiographic findings with an excellent clinical course.  相似文献   
94.
OBJECTIVES: To investigate the expression and clinical significance of MMP-2, MMP-7, MMP-9, and TIMP-1 in patients with nasal polyposis (NP) and chronic rhinosinusitis (CRS). STUDY DESIGN: Prospective study. SUBJECTS AND METHODS: This study involved 54 patients. There were three groups: nasal polyposis group, chronic rhinosinusitis group, and control group. Specimens were collected during endoscopic sinus surgery. Each sample was immunohistochemically examined. RESULTS: Expression of MMP-2 was found significantly increased in NP, whereas MMP-7 expression was found significantly increased in CRS (P < 0.001). TIMP-1 was significantly high in control group compared to CRS and NP (P < 0.001 and P = 0.002, respectively). CONCLUSIONS: Different regulation type of activation of MMPs has been found in these two diseases. If MMP-2 expression is intense in the mucosa, then this ends with polyp formation; if MMP-7 expression is intense, it ends with CRS or stays as CRS.  相似文献   
95.
96.
Extra-axial cavernous malformations (cavernomas) of the central nervous system are rare. Although occasional cases located in different parts of the central nervous system have been reported, only five cases of extra-axial cavernous malformation in the cerebellopontine angle are to be found. We describe here two additional cases of cavernomas in the cerebellopontine angle causing hearing loss and tinnitus presenting as vestibular schwannoma. Electronic Publication  相似文献   
97.
STUDY OBJECTIVE: To evaluate the impact of interpleural analgesia (IP) on postthoracotomy pain and respiratory function as an alternative to thoracic epidural analgesia (TEA). DESIGN: Prospective, randomized study. SETTING: Tertiary-care military hospital. PATIENTS: Sixty young patients scheduled for elective thoracic surgery (correction of aorta coarctation and patent ductus arteriosus). INTERVENTIONS: Patients were randomized into two groups to receive either IP or TEA for postthoracotomy pain management. MEASUREMENTS: Patients in the IP group (n = 30) had a catheter inserted between the parietal and visceral pleura by a surgeon, and 0.2% ropivacaine was given through this catheter. In the TEA group, ropivacaine was administered through a thoracic epidural catheter. The impact of both methods on pain control, respiratory function, and pulmonary complications was analyzed and compared. MAIN RESULTS: The frequency of atelectasis and pleural effusion was also significantly high in the IP group (P < 0.01). Respiratory function and postoperative pain scores were better in the TEA group (P < 0.01). Arterial blood gas analysis on the fifth postoperative day was significantly better in the TEA group. CONCLUSION: Thoracic epidural analgesia has more beneficial effects on respiratory function and postoperative pain after thoracotomy than does IP.  相似文献   
98.
The heels of 23 patients who were diagnosed with unilateral/bilateral plantar fasciitis were evaluated via ultrasonography and compared with their asymptomatic feet and a control group of 23 people. Plantar fascial thickness, echogenity, and heel pad thickness were evaluated, and the results were statistically analyzed. For symptomatic feet, increased thickness of the fascia and reduced echogenity were constant ultrasonographic findings (mean, 4.79 mm for symptomatic feet; 2.17 mm for control group, P < .05). No significant difference was found between heel pads of the diseased and healthy feet (mean, 12.96 mm for symptomatic feet; 13.10 mm for control group; P > .05). Ultrasonography seems to be a valuable, noninvasive diagnostic tool for the evaluation of plantar fasciitis.  相似文献   
99.
This study investigated the effect of rifampin on the thickness of capsules around silicone implants by bactericidal activity against Stapylococcus epidermidis. Silicone blocks (1 × 1 cm) were placed into pockets created for each of the 40 rats included in the study. In group 1, the operation was performed under aseptic conditions. In group 2, standard S. epidermidis was inoculated into the pocket, whereas rifampin and S. epidermidis were applied in group 3. In group 4, only rifampin was applied topically on implants. After 12 weeks, the peri-implant capsules were removed and examined under a photomicroscope and a scanning electron microscope. The mean thickness of the capsules was 63.307 μm in group 1, 111.538 μm in group 2, 43.076 μm in group 3, and 30.384 μm in group 4. The differences between groups 2 and 3 and groups 2 and 4 were found to be statistically significant (p < 0.001). Rifampin appears to be an agent for preventing peri-implant capsule formation.  相似文献   
100.
BACKGROUND: Angiogenesis has an important role in liver regeneration. Antiangiogenic response in remnant liver following resection and its relationship to regeneration is not well known. The aim of this study was to investigate the effect of hepatectomy size on serum endostatin levels, and the effect of endostatin levels to liver regeneration after partial hepatectomy in normal and cirrhotic mice. MATERIALS AND METHODS: Sixty noncirrhotic and 36 carbon tetrachloride-induced cirrhotic mice were included in the study. Noncirrhotic mice were randomly divided into four main groups: sham, 20%, 40%, and 70% hepatectomy groups. Similarly, cirrhotic mice were randomly divided into three main groups: sham, 20%, and 40% hepatectomy groups. The mice in each group were further divided into two subgroups to compare serum endostatin levels and liver regeneration indexes on days 1 and 14. Liver regeneration was evaluated by the proliferating cell nuclear antigen-labeling index. Serum endostatin level was measured to evaluate antiangiogenic response. RESULTS: Serum endostatin levels on the first day and 14th day increased significantly in correlation with the hepatectomy size, both in normal mice and cirrhotic mice (P < 0.05). In normal mice with high regeneration indexes that underwent 40% and 70% hepatectomies, there was a significant increase in serum endostatin levels on the 14th day compared with the first day (P < 0.05). However, the increase in mice that underwent 20% hepatectomies was not significant. After 20% and 40% hepatectomies, first day serum endostatin levels were significantly higher in cirrhotic mice compared with normal mice (P < 0.05), which was independent of regeneration. Nevertheless, after 40% hepatectomies, 14th day serum endostatin levels were significantly lower in cirrhotic mice compared with normal mice, attributable to the limited regeneration capacity of cirrhotic liver (P < 0.05). Regeneration capacity of cirrhotic liver was low at all times. CONCLUSIONS: The current study suggests that there is a significant relationship between serum endostatin levels and regeneration capacity after hepatectomy in normal mice. On the other hand, following resection of cirrhotic liver, regeneration capacity is depressed and high endostatin levels are independent of hepatic regeneration.  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