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   178592篇
  免费   1756篇
  国内免费   24篇
耳鼻咽喉   1225篇
儿科学   6770篇
妇产科学   3069篇
基础医学   16612篇
口腔科学   1654篇
临床医学   13405篇
内科学   31580篇
皮肤病学   818篇
神经病学   16695篇
特种医学   9003篇
外科学   29383篇
综合类   2330篇
预防医学   18259篇
眼科学   2849篇
药学   9480篇
中国医学   631篇
肿瘤学   16609篇
  2023年   150篇
  2022年   76篇
  2021年   165篇
  2020年   225篇
  2019年   123篇
  2018年   22176篇
  2017年   17549篇
  2016年   19735篇
  2015年   1086篇
  2014年   1080篇
  2013年   1090篇
  2012年   7081篇
  2011年   21126篇
  2010年   19021篇
  2009年   11773篇
  2008年   19600篇
  2007年   21760篇
  2006年   641篇
  2005年   2215篇
  2004年   3403篇
  2003年   4340篇
  2002年   2503篇
  2001年   353篇
  2000年   478篇
  1999年   229篇
  1998年   245篇
  1997年   262篇
  1996年   149篇
  1995年   149篇
  1994年   123篇
  1993年   80篇
  1992年   65篇
  1991年   120篇
  1990年   142篇
  1989年   98篇
  1988年   67篇
  1987年   56篇
  1986年   47篇
  1985年   57篇
  1984年   36篇
  1983年   34篇
  1982年   32篇
  1980年   46篇
  1974年   25篇
  1969年   27篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   57篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Introduction Iniencephaly, a neural tube defect involving occiput and inion and combined with rachischisis of the cervical, thoracic spine, and retroflexion position of the head is a very rare congenital abnormality of the fetus–newborn with a 0.1–10 of 10,000 prevalence. This abnormality’s prognosis is thought to be dismal. This abnormality can be associated with other abnormalities such as anencephaly, encephalocele, hydrocephalus, cyclopia, absence of the mandible, cleft lip and palate, cardiovascular disorders, diaphragmatic hernia, renal abnormalities, overgrowth of the arms compared to the legs, and club food and gastrointestinal atresia. Discussion Most of the patients are dead born, and the others die in a few hours. There are only six previously documented long-term survivors. In our case, our patient with iniencephalic signs and findings is still living. She is 2 years old now. We think that this patient presents a mild form of iniencephaly.  相似文献   
62.
Background and aims Since the introduction of endovascular aortic aneurysm repair (EVAR) for aortic aneurysms, the number of juxtarenal aortic aneurysms (JRA) has been growing steadily due to selection bias (neck morphology for EVAR). This case-match study compares the perioperative outcome and midterm results of suprarenally clamped JRA with infrarenal aortic aneurysms (AAA). Methods From 1997 to 2004, patients who received open surgery with suprarenal clamping for JRA were included in the study and compared to matched patients with infrarenal clamping (AAA). Measurements analyzed were the in-hospital mortality and morbidity. Midterm results were obtained through clinical investigation and magnetic resonance angiography imaging. Results Thirty-five patients (mean age, 68.4 years; 30 male and 5 female) received suprarenal cross-clamping for JRA. The overall in-hospital mortality for JRA and for the controls (AAA) with elective aortic repair was 4.5% (6.1% JRA; 3% AAA, p = 0.058). The morbidity of JRA was elevated according to the rate of pulmonary complications (p = 0.021) and the need for re-operation (p = 0.019). The mean follow-up time was 2.3 years (range, 8–96 months). At follow-up, 28 patients (80%) from the JRA group and 29 patients from the AAA group (82.9%) were alive. Conclusion Open aortic surgery for JRA with the need for suprarenal cross-clamping shows a slightly elevated in-hospital mortality rate without statistical significance and equal midterm mortality results in comparison with infrarenally clamped aortic aneurysms.  相似文献   
63.

Background  

Liver transplantation in presence of diffuse portal vein thrombosis is possible by using caval blood as portal inflow, through cavo-portal transposition. However, clinical results are heterogeneous and experimental studies are needed, but similar hemodynamic conditions are difficult to obtain, especially in small animals. Herein we describe a new simple model of cavo-portal transposition in rat.  相似文献   
64.

Background  

Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA) to see how OA was constructed and to consider the implications for self-care.  相似文献   
65.
Small bowel transplantation (SBT) is associated with poorly understood enteric dysfunction. The study of SBT in mice is hindered by the technical difficulty of orthotopic SBT in the mouse. Our aim was to develop an easy preparation of extrinsic denervation of the entire jejunoileum in mice as a model of orthotopic SBT. All neurolymphatic tissues accompanying the superior mesenteric artery (SMA) and vein (SMV) were ligated just distal to the middle colic vessels. The SMA and SMV were then stripped of investing adventitia, and the mesentery to jejunum and colon were transected radially. Jejunum and colon were not transected and reanastomosed. To confirm extrinsic denervation 1, 3, and 6 months later, segments of small bowel were stained for protein gene product 9.5 (PGP9.5) and tyrosine hydroxylase (TH). Tyrosine hydroxylase immunoreactive intensity was then quantified using a semiquantitative analysis. Immunohistochemical fluorescence showed persistence of PGP9.5 immunoreactivity confirming enteric nerves in jejunoileum; however, there was no TH immunoreactivity in jejunoileum in denervated mice despite the expected preservation of TH immunoreactivity in the still-innervated duodenum at 1 month. At 3 months, sparse immunoreactivity for TH was present, and by 6 months, reinnervation of TH-containing nerves appeared similar to controls. Quantification of intensity at each time-point further confirmed this trend. This technique in the mouse accomplishes a complete extrinsic denervation of jejunoileum early postoperatively (1 and 3 months); reinnervation occurs by 6 months. This is an easily learned murine model of orthotopic SBT. Presented at the American Gastroenterological Association during Digestive Disease Week in Los Angeles, CA, as a poster presentation on May 23 2006. Abstract published in GastroenterologyE 2006; 130:A604.  相似文献   
66.
Background In cases of synchronous colorectal hepatic metastases, the primary colorectal cancer strongly influences on the metastases. Our treatment policy has been to conduct hepatic resection for the metastases at an interval of 3 months after colorectal resection. We examined the appropriateness of interval hepatic resection for synchronous hepatic metastasis. Materials and methods The subjects were 164 patients who underwent resection of hepatic metastasis of colorectal cancer (synchronous, 70 patients; metachronous, 94 patients). Background factors for hepatic metastasis and postoperative results were compared for synchronous and metachronous cases. Results The cumulative survival rate for 164 patients at 3, 5, and 10 years postoperatively was 71.9%, 51.8%, and 36.6%, and the post-resection recurrence rate in remnant livers was 26.8%. Interval resection for synchronous hepatic metastases was conducted in 49 cases after a mean interval of 131 days. No difference was seen in postoperative outcome between synchronous and metachronous cases. Conclusion The outcome was similarly favorable in cases of synchronous hepatic metastasis and in cases of metachronous metastasis. Delaying resection allows accurate understanding of the number and location of hepatic metastases, and is beneficial in determining candidates for surgery and in selecting surgical procedure.  相似文献   
67.

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.  相似文献   
68.
Isolated pure dislocations of the fifth carpo-metacarpal joint are extremely rare injuries. The dorsal form was described in mere 12 cases. The diagnosis can be easily missed. The lesion is also often overlooked in the routine diagnostic X-ray. Lateral and oblique views are important for the recognition of the true extent of the lesion. Treatment of these injures is still controversial and both closed reduction with percutaneous pinning or open reduction with internal fixation are advocated. The goal of treatment is early reduction and fixation of the metacarpal. Early diagnosis is the key to success. The aim of this paper is to review literature and present two new cases.  相似文献   
69.
With a view to the development of new controlled drug delivery systems, the formation of an interpolyelectrolyte complex (IPEC) between chitosan (CTS) and Eudragit L100 (L-100) has been studied. The structure of this IPEC is such that two maxima are observed in the curves of IPEC swelling in the media with different pH values. The release of a model drug (ibuprofen) from IPEC-based tablets is significantly retarded, and this delay can be controlled by changing the molecular weight of CTS in the IPEC composition. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 12, pp. 44–46, December, 2005.  相似文献   
70.
Introduction Amisulpride is a substituted benzamide that, at low doses, selectively blocks D2 and D3 presynaptic dopamine receptors, enhancing dopaminergic transmission in frontal cortex and limbic areas. Many clinical studies versus placebo, tricyclic antidepressants and selective serotonin reuptake inhibitors showed amisulpride antidepressant effect, supporting its safety and rapid onset of action. In oncological population, depression is quite frequent and difficult to treat because of the particular sensitivity of cancer patients to the antidepressants’ side effects. Goals of work The aims of this study were to evaluate efficacy, safety and tolerability of low doses of amisulpride (50 mg) in oncological, depressed patients during chemotheraphy. Materials and methods One hundred six consecutive cancer outpatients with depressive symptoms were treated in a prospective, intention to treat, 4-week study, and were evaluated in single-blind with Montgomery Asberg rating scale for depression (MADRS), clinical global impression (CGI) and dosage record treatment emergent symptom scale (DOTES) to assess side effects of treatment. Main results After 4 weeks of treatment, scores of MADRS and CGI significantly improved (p < 0.002; p < 0.001, respectively), with a reduction of depressive symptoms concerning both emotional (such as apparent sadness, reported sadness, inner tension, etc.) and physical cluster (such as lack of appetite, reduction in weight, tiredness and insomnia) with good tolerability (only two patients dropped out). Conclusions This study is the first trial on the use of amisulpride in a cohort of oncological, depressed patients during chemotherapy. Amisulpride demonstrated high efficacy and safety. Controlled studies are needed to confirm these preliminary data.  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