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   7277篇
  免费   387篇
  国内免费   79篇
耳鼻咽喉   86篇
儿科学   62篇
妇产科学   128篇
基础医学   1182篇
口腔科学   178篇
临床医学   488篇
内科学   1337篇
皮肤病学   212篇
神经病学   482篇
特种医学   425篇
外科学   914篇
综合类   27篇
预防医学   237篇
眼科学   97篇
药学   967篇
中国医学   160篇
肿瘤学   761篇
  2024年   4篇
  2023年   47篇
  2022年   169篇
  2021年   277篇
  2020年   122篇
  2019年   147篇
  2018年   228篇
  2017年   155篇
  2016年   271篇
  2015年   416篇
  2014年   412篇
  2013年   487篇
  2012年   808篇
  2011年   710篇
  2010年   408篇
  2009年   338篇
  2008年   446篇
  2007年   354篇
  2006年   339篇
  2005年   364篇
  2004年   305篇
  2003年   228篇
  2002年   182篇
  2001年   106篇
  2000年   104篇
  1999年   70篇
  1998年   29篇
  1997年   33篇
  1996年   23篇
  1995年   14篇
  1994年   16篇
  1993年   8篇
  1992年   14篇
  1991年   25篇
  1990年   13篇
  1989年   10篇
  1988年   13篇
  1987年   9篇
  1986年   8篇
  1985年   7篇
  1984年   3篇
  1981年   4篇
  1979年   3篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1967年   1篇
  1966年   2篇
排序方式: 共有7743条查询结果,搜索用时 0 毫秒
991.
992.
Previous reports of a solitary metastatic hepatocellular carcinoma have been rare. Because this tumor has a different treatment modality and prognosis, an accurate differential diagnosis is essential. Here we report a rare case of a solitary chest wall metastasis from unknown primary site of hepatocellular carcinoma. It involves a 51-year-old man who was admitted to our hospital because of a palpable left upper chest wall mass. The mass was resected and pathologic examination confirmed a diagnosis of metastatic hepatocellular carcinoma. Despite our investigation, no evidence was found that indicated the primary origin of the hepatocellular carcinoma. Four months later, the patient was admitted again because of spinal cord compression at the third and fourth thoracic vertebrae. Emergent decompressive laminectomy was performed and microscopic features revealed the same pathology as the initial chest wall mass resected 4 months earlier. After one year, a follow-up abdominal computed tomography (CT) still revealed no evidence of primary hepatocellular carcinoma.  相似文献   
993.
994.
CONTEXT: Thyroid cancer is among the 10 most common malignancies in populations in the Asia Pacific region, where access to various relevant health care resources varies widely. OBJECTIVE: An expert consensus conference was held to define regional patterns of practice and guidelines for optimal management of well-differentiated epithelial thyroid carcinomas. RESULTS: Practice patterns vary from country to country, as would be anticipated form their variety of ethnic and racial populations, health care systems, economies, and cultures. Thyroid cancer care is provided by a number of medical and surgical specialists, usually including endocrinologists. The thyroid surgical skills, experience, and outcomes vary widely in the region. Radioiodine is available, to a greater or lesser extent, is almost all countries. Laboratory services for thyroid function monitoring are universally accessible; thyroglobulin assays are available in most countries. Recombinant thyrotropin is approved for use in only two countries, but can be accessed in some others on a "named patient" compassionate need basis. Access to advanced imaging, for exampke, positron emission tomography (PET) scanning, is limited to a few countries. CONCLUSIONS: In light of these realities, appropriate strategies for initial treatment and postoperative monitoring of patients with thyroid cancer have been defined, and these are presented and discussed.  相似文献   
995.
Primary effusion lymphoma (PEL) is a recently recognized disease that occurs most often in immunosuppressed patients, either with human immunodeficiency virus (HIV) or in the posttransplantation setting, and it occasionally occurs in nonimmunosuppressed patients. Patients present with lymphomatous effusions in serous cavities--pleura, pericardium, or peritoneum--without any identifiable tumor mass. PEL rarely responds to systemic chemotherapy, and the prognosis is poor, with a median survival time of less than 6 months for most cohorts. A standard treatment for PEL has not yet been identified. We describe a patient with HIV-seronegative PEL who relapsed after combination chemotherapy and then underwent successful treatment with high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). The treatment was well tolerated, and the patient has been in remission for 12 months after HDC and ASCT.  相似文献   
996.
Chung KY  Lim KM  Chung SM  Lee MY  Noh JY  Bae ON  Chung JH 《Platelets》2006,17(3):127-133
To investigate shear stress-induced platelet activation, the cone-plate viscometer or the Couette rotational viscometer has been widely used. In a previous report, it was shown that shearing platelet-rich plasma using a Couette rotational viscometer could lead to an increase in pH by CO(2) release. However, any clear mechanism has not been provided. In this study, we examined whether shearing cell free plasma only using a cone-plate viscometer can also induce pH increase and studied the underlying mechanism of shear-induced pH increase by directly measuring total CO(2) (T(CO(2))) and CO(2) tension (P(CO(2))). When human plasma was sheared using a cone-plate viscometer, the pH of the human plasma increased time- and shear rate-dependently. Although T(CO(2)) of human plasma was not affected, P(CO(2)) was decreased by shearing, indicating that the decreased P(CO(2)) is associated with a pH increase of plasma. In addition, the pH of bicarbonate-containing suspension buffer was also shown to be increased by shearing; suggesting that the platelet studies using suspension buffers containing bicarbonate could be affected similarly. The effects of pH changes on shear stress-induced platelet activation were also investigated in the same in vitro systems. While shear stress-induced platelet aggregation was not affected by the pH changes, P-selectin expression was significantly increased in accordance with the pH increase. In conclusion, shear stress using a cone-plate viscometer induces pH increase in plasma or bicarbonate-containing suspension buffer through a P(CO(2)) decrease and the pH changes alone can contribute to platelet activation by enhancing shear stress-induced P-selectin expression.  相似文献   
997.
Cardiac resynchronization therapy (CRT) has been proven its value in adult patients with congestive heart failure of low ejection fraction and wide QRS duration. Contrast to adult patients, CRT has been rarely applied for young patients. We report on a 9-yr-old boy with progressive left ventricular (LV) dilatation and dysfunction following chronic VVI pacemaker therapy for congenital complete atrioventricular block associated with maternal anti-SSA/Ro and SSB/La antibody. His LV dysfunction was improved after epicardially established CRT.  相似文献   
998.
Solid-pseudopapillary tumor of the pancreas   总被引:2,自引:0,他引:2  
BACKGROUND: Solid-pseudopapillary tumor (SPT) of the pancreas is a low-grade malignancy, which has been infrequently observed in adolescent and young adult females since first report by Frantz in 1959. In this article, we describe our experience of 8 cases of SPT with the clinical features, diagnosis, treatments, and outcomes. METHODS: We retrospectively reviewed the medical records and images of 8 patients who underwent surgery for SPT between January 1995 and December 2004. RESULTS: Seven females and 1 male with the mean age of 29 years (range, 10 to 64) at presentation were identified. Three patients presented palpable abdominal mass, 2 with abdominal pain, and the remainder with no specific symptom. The mean diameter of the tumors was 7.9 cm (range, 4.0 to 10.0). Four were located in the tail, 3 in the body, and 1 in the head. Surgical procedure included distal pancreatectomy with/without splenectomy in 7 patients and Whipple operation in 1 with no surgical morbidity and mortality. All were alive without evidence of recurrence after mean follow-up of 26.4 months (range, 1 to 66). CONCLUSIONS: SPT of the pancreas is an unusual neoplasm and typically occurs in young females presenting well-demarcated pancreatic masses, which are amenable to cure by complete surgical resection.  相似文献   
999.
We report a case of ceramic liner fracture in a 34-year-old man that occurred 1 year 9 months after total hip arthroplasty with a BiCONTACT (Aesculap, Tuttlingen, Germany) ceramic-on-ceramic prosthesis. The ceramic liner was found within the metal shell in 4 large pieces and multiple small fragments in the peripheral portions. Its condition indicated that the possible mechanism of late ceramic liner chip fracture was repeated episodes of impingement between the prosthetic neck and the edge of the ceramic liner. Squatting, kneeling, and sitting cross-legged caused impingement. These positions are more common in Asian populations than in Western populations. After the joint was thoroughly irrigated, a new modular ceramic liner and a 28-mm ceramic head were implanted.  相似文献   
1000.
The antiallergic effects of magnolol and honokiol, isolated from the bark of Magnolia obovata (family Magnoliaceae), were investigated both in vitro and in vivo. Magnolol and honokiol potently inhibited passive cutaneous anaphylaxis reactions in mice induced by IgE-antigen complex as well as compound 48/80-induced scratching behaviors. These constituents exhibited not only potent inhibitory activity on the degranulation of RBL-2H3 cells induced by IgE-antigen complex, with IC(50) values of 45 and 55 muM, respectively, but also inhibited the protein expressions of IL-4 and TNF-alpha. Based on these findings, magnolol and honokiol may improve IgE-induced allergic diseases.  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