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   2385篇
  免费   131篇
  国内免费   15篇
耳鼻咽喉   19篇
儿科学   27篇
妇产科学   8篇
基础医学   285篇
口腔科学   63篇
临床医学   137篇
内科学   549篇
皮肤病学   20篇
神经病学   344篇
特种医学   87篇
外科学   547篇
综合类   11篇
预防医学   40篇
药学   88篇
中国医学   1篇
肿瘤学   305篇
  2024年   3篇
  2023年   27篇
  2022年   50篇
  2021年   104篇
  2020年   52篇
  2019年   54篇
  2018年   60篇
  2017年   50篇
  2016年   63篇
  2015年   64篇
  2014年   91篇
  2013年   101篇
  2012年   151篇
  2011年   164篇
  2010年   96篇
  2009年   80篇
  2008年   143篇
  2007年   156篇
  2006年   154篇
  2005年   165篇
  2004年   153篇
  2003年   117篇
  2002年   143篇
  2001年   25篇
  2000年   31篇
  1999年   18篇
  1998年   32篇
  1997年   39篇
  1996年   25篇
  1995年   13篇
  1994年   19篇
  1993年   12篇
  1992年   10篇
  1991年   6篇
  1990年   8篇
  1989年   8篇
  1988年   4篇
  1987年   5篇
  1986年   5篇
  1985年   3篇
  1984年   6篇
  1983年   4篇
  1982年   1篇
  1981年   6篇
  1980年   2篇
  1979年   2篇
  1978年   2篇
  1976年   2篇
  1966年   2篇
排序方式: 共有2531条查询结果,搜索用时 15 毫秒
11.
Background Japanese surgeons have to macroscopically assess nodal metastasis from colon cancer according to the general rules established in Japan. Adjuvant therapy is sometimes started after macroscopic assessment of nodal metastasis. Macroscopic assessment, however, is difficult in many cases. Methods We evaluated the reliability of macroscopic assessment of nodal metastasis in colon cancer by (1) comparing the number of nodes picked up macroscopically with that of nodes recognized microscopically, and (2) by comparing the number of metastatic nodes found between macroscopic and microscopic examination. Results The number of nodes found during macroscopic examination was equal to that found in microscopic examination in only 52 of 206 cases (25%). Although 120 of 206 cases (58%) were judged macroscopically to have metastatic nodes, 61 had no metastatic nodes found microscopically. Sensitivity and specificity for the recognition of cases with nodal metastasis was 85.5% and 55.5%, respectively. The number of metastatic nodes in macroscopic examination was equal to that in microscopic examination in 90 cases (44%). Conclusion Because macroscopic assessment of nodal metastasis is not reliable, physicians should not rely on macroscopic assessment to indicate the need for further therapy, such as adjuvant chemotherapy. The recommendation for macroscopic assessment of nodal metastasis should be eliminated from the general rules in Japan.  相似文献   
12.
13.
Purpose Although many reports support stimulated in vitro fertilization, several patients do not respond to it well. Furthermore, stimulated treatment could be associated with reduced ovarian response. We describe three successful cases involving patients of advanced age from whom dominant follicles were retrieved during the natural cycle. Materials and methods All patients had failed to bear children through stimulated in vitro fertilization. In case 1, a follicle was retrieved after a gonadotropin-releasing hormone agonist was used to induce luteinizing hormone surge. In cases 2 and 3, pregnancy was achieved via completely natural cycles. Results One embryo was transferred every 16 cycles. Ongoing pregnancy—defined as pregnancy progressing beyond gestation week 9—was established in three cycles. The patients successfully delivered and had uneventful neonatal courses. Conclusion Mature oocyte retrieval followed by natural rather than stimulated in vitro fertilization might be a potential treatment for patients of advanced age when stimulated in vitro fertilization has been repeatedly unsuccessful. Capsule We describe three successful pregnancies and deliveries achieved via natural IVF cycles: the patients were older than 37 years with repeated failures by stimulated IVF.  相似文献   
14.
OBJECTIVESTo evaluate the feasibility of open chest management with our modified negative pressure wound therapy immediately after cardiac surgery as a therapy for atypical tamponade.METHODSOpen chest with modified negative pressure wound therapy was performed immediately after cardiac surgery. The surface of the heart and the vessels were covered with non-adherent siliconized gauze. The sternal halves were stented using edge-cut disposable syringes to maintain a larger mediastinal cavity. Approximately 45 mm of distance was kept between the sternal edges. A trimmed sterile polyvinyl foam sponge was inserted into the mediastinum, the entire wound was sealed and negative pressure (−50 to −75 mmHg) was applied using a suction generator. Delayed chest closure was performed in a standard manner once the haemodynamic status was stabilizsed.RESULTSThe mortality rate was 3/15 (20%) patients. Deep sternal wound infection occurred in 1/15 (6.7%) patients. Five patients were extubated during the open chest management. Sternal closure was delayed for median of 3 days after the initial surgery. There was no incidence of bleeding complications or need for additional haemostatic procedures.CONCLUSIONSNegative pressure wound therapy performed immediately after cardiac surgery was feasible in our small number of patients.Clinical registration numberStudy ID: 2020-149.  相似文献   
15.
Background: Although the association between asthma control and body mass index (BMI) has been thoroughly investigated, most of this work has focused on the influence on asthma incidence or the effect of obesity on asthma control. To date, there have been no published studies on the influence of underweight on asthma control.Methods: The aim of this study was to investigate the influence of underweight, as defined by the Japan Society for the Study of Obesity (JASSO), on asthma control in Japanese asthmatic patients. Using data from questionnaire surveys administered by the Niigata Asthma Treatment Study Group, we compared asthma control, as measured by the Asthma Control Test (ACT), between a normal weight group (18.5 kg/m2 =< BMI < 25 kg/ m2) and an underweight group (BMI < 18.5 kg/m2).Results: Of the asthmatic patients who completed the 2008 and 2010 surveys, 1464 and 1260 cases were classified as being in the normal weight group, and 174 and 155 cases were classified as being in the underweight group. The ACT score (median, [interquartile range]) in the underweight group in 2008 (22, [19-24]) and 2010 (23, [19-25]) was significantly lower than that in the normal group in 2008 (23, [20-25]) and in 2010 (24, [21-25]).Conclusions: This study is the first, large-scale investigation of the influence of underweight on asthma control, and we have confirmed an adverse influence in a clinical setting. A potential mechanism for this interaction was unknown. Further investigation will be required.  相似文献   
16.
Objective: The purpose of this study was to examine the relationship betweenthe emotional intelligence quotient and health-related quality of life using structuralequation modeling.Methods: A self-administered questionnaire survey was conducted among 1,911mothers who visited the Health Center for an infant medical examination. A hypotheticalmodel was constructed using variables of the emotional intelligence quotient, socialsupport, coping, parenting stress, and perceived health competence.Result: There were a total of 1,104 valid responses (57.8%). Significantstandardized estimates were obtained, confirming the goodness of fit issues with themodel. The emotional intelligence quotient had a strong impact on physical andpsychological quality of life, and showed the greatest association with coping. This studydiffered from previous studies in that, due to the inclusion of social support andexplanatory variables in coping, an increase in coping strategies was more highlyassociated with emotional intelligence quotient levels than with social support.Conclusion: An enhanced emotional intelligence quotient should be considereda primary objective to promote the health of mothers with infant children.  相似文献   
17.
Recently, simultaneous hepatectomy and pancreatoduodenectomy has been performed for the treatment of some biliary tract cancers in Japan. Postoperative hepatic failure is a common and potentially fatal complication. The aim of this study was to examine the reduction in the rate of liver regeneration after 70% hepatectomy (Hx) alone or in combination with 70% pancreatectomy (HPx). Male Sprague-Dawley rats underwent hepatectomy or simultaneous hepatectomy and pancreatectomy. The ratio of liver weight to body weight, the labeling index of hepatocytes in vivo, and DNA synthesis of the hepatocytes and/or Kupffer cells in primary culture were analyzed. The ratio of liver weight to body weight and the labeling index in HPx rat were found to be significantly lower than those values in Hx rats. There were no significant differences in plasma alanine aminotransferase levels between the two groups. The inhibitory effect on DNA synthesis was observed with coculture of hepatocytes and Kupffer cells when the portal plasma obtained 1 hour after operation was added. We further observed that the conditioned medium of Kupffer cells stimulated by the addition of the portal plasma that was obtained 1 hour after HPx inhibited DNA synthesis of hepatocytes. This effect was abolished after incubation at 56° C for 30 minutes. These results strongly suggest the existence of a growth inhibitory factor in portal plasma after HPx. This heat-labile growth inhibitory factor was released from Kupffer cells and would appear to act on hepatocytes in a paracrine manner. Supported by the Kanae Foundation for Life and Sociomedical Science, Japan. Presented at the Thirty-Eighth Annual Meeting of The Society-for Surgery of the Alimentary Tract, Washington, D.C., May 11–14, 1997.  相似文献   
18.
OBJECTIVE: We examined the possibility of intraoperative ultrasonography during video-assisted thoracic surgery (VATS) to localize and make a qualitative diagnosis of small peripheral pulmonary nodules. METHODS: Ultrasonography during VATS and conventional thoractomy was performed on 25 and 18 nodules, respectively, all which were localized in the peripheral lung, were less than 30 mm in diameter and for which there was no definitive diagnosis. RESULTS: All 25 nodules, including 10 invisible but palpable and three both invisible and non-palpable, could be localized by ultrasonography during VATS. If nodules were located less than 15 mm from the pleural surface, ultrasonography during VATS could detect nodules 10 mm or less in diameter. The rate of malignant tumors among 11 of 12 pulmonary nodules (91.6%) showing both heterogeneous and ill-defined patterns was significantly higher than 6 of 16 nodules (37.5%) showing both homogeneous and well-defined patterns on ultrasonography. CONCLUSIONS: Our study suggested that ultrasonography during VATS is useful for the detection of peripheral pulmonary nodules, even when they are not identified on video images or palpation, and may enable a differential diagnosis between malignant and non-malignant lesions.  相似文献   
19.
Annals of Nuclear Medicine - Amyloid positron emission tomography (PET) can reliably detect senile plaques and fluorinated ligands are approved for clinical use. However, the clinical impact of...  相似文献   
20.

Background  

Most elderly patients have cardiopulmonary diseases anamnesis and a perceived risk of perioperative complications. The responsible lesion may be located more cranially in elderly patients with cervical spondylotic myelopathy (CSM) compared with that in younger patients. The study aimed at evaluating cardiopulmonary dysfunction of CSM and effects of surgery on cardiopulmonary function and perioperative complications.  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