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   2838篇
  免费   125篇
  国内免费   17篇
耳鼻咽喉   27篇
儿科学   35篇
妇产科学   43篇
基础医学   277篇
口腔科学   163篇
临床医学   288篇
内科学   706篇
皮肤病学   40篇
神经病学   202篇
特种医学   101篇
外科学   346篇
综合类   6篇
一般理论   1篇
预防医学   116篇
眼科学   21篇
药学   299篇
中国医学   8篇
肿瘤学   301篇
  2023年   20篇
  2022年   50篇
  2021年   79篇
  2020年   63篇
  2019年   56篇
  2018年   77篇
  2017年   60篇
  2016年   73篇
  2015年   64篇
  2014年   117篇
  2013年   142篇
  2012年   232篇
  2011年   211篇
  2010年   123篇
  2009年   103篇
  2008年   175篇
  2007年   178篇
  2006年   187篇
  2005年   169篇
  2004年   150篇
  2003年   136篇
  2002年   132篇
  2001年   14篇
  2000年   22篇
  1999年   20篇
  1998年   26篇
  1997年   22篇
  1996年   20篇
  1995年   23篇
  1994年   11篇
  1993年   16篇
  1992年   11篇
  1991年   9篇
  1990年   5篇
  1989年   13篇
  1988年   5篇
  1987年   17篇
  1986年   8篇
  1985年   11篇
  1984年   14篇
  1983年   18篇
  1982年   12篇
  1981年   13篇
  1980年   12篇
  1979年   5篇
  1978年   4篇
  1972年   4篇
  1961年   3篇
  1939年   3篇
  1937年   3篇
排序方式: 共有2980条查询结果,搜索用时 15 毫秒
11.
Alcohol abuse after liver transplantation can seriously impact graft and patient survival. However, to date, there is no defined standard procedure to identify patients consuming alcohol after liver transplantation. The aim of this study was to analyze the diagnostic value and clinical impact of routinely measured urinary ethyl glucuronide (uEtG) – a metabolite of ethanol – in patients after liver transplantation. Data of 362 consecutive patients after liver transplantation who visited the University Hospital of Tuebingen for outpatient follow-up were analyzed. Forty-eight patients (13%) displayed positive uEtG results. The uEtG positive group contained significantly more patients with pretransplant alcoholic liver disease. However, two thirds of the uEtG positive patients had no history of pretransplant alcoholic liver disease. Several clinical parameters were significantly associated with positive uEtG. In order to enable a more cost-effective application of uEtG in the future, a clinical risk score was developed (specificity 0.95). In conclusion, routine testing for uEtG reveals a considerable percentage of patients practicing alcohol intake after liver transplantation. Application of our proposed risk score could help focusing uEtG testing on patients at risk.  相似文献   
12.
Liver resection still represent the treatment of choice for liver malignancies, but in some cases inadequate future remnant liver (FRL) can lead to post hepatectomy liver failure (PHLF) that still represents the most common cause of death after hepatectomy. Several strategies in recent era have been developed in order to generate a compensatory hypertrophy of the FRL, reducing the risk of post hepatectomy liver failure. Portal vein embolization, portal vein ligation, and ALLPS are the most popular techniques historically adopted up to now. The liver venous deprivation and the radio-embolization are the most recent promising techniques. Despite even more precise tools to calculate the relationship among volume and function, such as scintigraphy with 99mTc-mebrofenin (HBS), no consensus is still available to define which of the above mentioned augmentation strategy is more adequate in terms of kind of surgery, complexity of the pathology and quality of liver parenchyma. The aim of this article is to analyse these different strategies to achieve sufficient FRL.  相似文献   
13.
Journal of Public Health - Neighbourhood composition is considered a social determinant of mental health that can be addressed by policymakers to improve outcomes. Deprived neighbourhoods typically...  相似文献   
14.
We observed that peripheral T cells activated in vivo or invitro by superantigens are susceptible to cell death when theirantigen receptor is cross-linked with the appropriate anti-ßTCR mAb. TCR ligation by mAbs specifically drove the T cellclonal deletion in both CD4+ and CD8+ cell subsets. An IL-2/1L-2Rinteraction seems to be a critical step In predisposing superantigenactivated cells to death; In fact, in vivo IL-2R bockade reversedT cell deletion In superantlgen plus anti-ß TCR mAbtreated mice. TCR ligatlon by mAbs also produced cell deathof the relevant targets in in vitro IL-2 activated T cells.Surprisingly, no T cell deletion was demonstrable in IL-2 activatedcells following staphylococcal enterotoxin B - TCR Interaction,ruling out the possibility that superantigen in Itself can inducecell death. Thus, while superantigen activation opens the celldeath program, a subsequent TCR-antigen (self) Interaction appearsnecessary to produce clonal deletion in mature T lymphocytes.  相似文献   
15.
Three structurally related non-xanthine compounds, CGS 15943, ZM 241385 and SCH 58261, are potent A2A adenosine receptor antagonists and have been used as tools in many pharmacological studies. We have now characterized their affinity and selectivity profile on human adenosine receptors stably transfected into either CHO cells (A1 and A2B receptors) or HEK-293 cells (A2A and A3 receptors). In binding studies using [3H]SCH 58261 as a radioligand, the three compounds were equally potent at A2A receptors, their K i value being less than 1 nM. Affinity for A1 and A3 receptors was measured using [3H]DPCPX and [125I]AB-MECA as radioligands. Given the lack of selective ligands, interaction with A2B receptors was assessed using the cAMP accumulation assay following stimulation by the adenosine receptor agonist N-ethylcarboxamidoadenosine (NECA). CGS 15943 was almost as potent at A1 receptors (K i 3.5 nM) as at A2A receptors, showed moderate affinity for A3 receptors (K i 95 nM) and also interacted with A2B receptors (K i 44 nM; pA2 7.5). ZM 241385 showed little affinity for A1 receptors (K i 255 nM), and did not interact with A3 receptors (K i>10 μM); however, it displayed moderate affinity for A2B receptors (K i 50 nM; pA2 7.3). SCH 58261 had weak affinity for A1 receptors (K i 287 nM), no interaction with A3 receptors (K i>10 μM), and showed negligible interaction with A2B receptors (K i 5 μM; pA2 6.0). These data indicate that SCH 58261 is the most selective A2A antagonist currently available. Moreover, the different receptor selectivity of these three chemically related compounds provides useful information to progress with structure-activity relationship studies. Received: 2 July 1998 / Accepted: 6 October 1998  相似文献   
16.
The aim of this study was to determine the influence of socio-demographic and professional factors on physicians' attitudes to the terminally ill. Between May 1992 and May 1993, a survey was conducted in the province of Pordenone (north-east, Italy) in order to analyse a number of specific issues, such as emotional involvement, the need for aggressive treatments and the communication of diagnosis and prognosis. After obtaining a list of board-certified physicians from the Medical Association office in Pordenone, a modification of the cancer questionnaire of Haley and Blanchard (QSPT) was mailed to 916 doctors. Of these, 605 (60%; 487 male, 118 female; mean age 41 ± 11 SD) returned the completed questionnaire. Within the group of responders, we identified three main subgroups, according to their type of activity: general practitioners (175, 29%), hospital doctors (235, 39%) and other doctors (195, 32%). In age, sex and activity, the only significant difference between responders and non-responders was age (mean age 41 and 43 years respeetively). Most of the responders (77%) stated that they were able to deal with the terminally ill patient and his/her needs; 44%, however, admitted that patients' anxiety is sometimes unbearable. For the vast majority of the doctors polled (91%), providing a comfortable environment for an incurable patient was more important than pursuing aggressive treatment, but only 44% were convinced of the uselessness of aggressive care. To the question on whether to disclose information about imminent death to allow patients to prepare spiritually, 37% answered No, 38% Yes, and 25% were uncertain. Almost all responders (95%), however, believed in the beneficial effect of hope on the terminally ill. Ourresults suggest that doctors' professional and, most of all, sociodemographic and cultural factors determine the relationship with the patient on both the emotional and the clinical decision-making levels.  相似文献   
17.
18.
OBJECTIVE: To estimate the clinical efficacy of topical sinecatechins, a defined green tea extract, in the treatment of external genital and perianal warts. METHODS: This was a randomized, double-blind, vehicle-controlled trial involving 502 male and female patients aged 18 years and older, with 2-30 anogenital warts ranging from 12 to 600 mm(2) total wart area. Patients applied sinecatechins ointment 15% or 10% or vehicle (placebo) three times daily for a maximum of 16 weeks or until complete clearance of all warts, followed by a 12-week treatment-free follow-up to assess recurrence. RESULTS: Complete clearance of all baseline and newly occurring warts was obtained in 57.2% and 56.3% of patients treated with sinecatechins ointment 15% and 10%, respectively, compared with 33.7% for vehicle (both P<.001). Significance was observed at weeks 4 and 6 and all subsequent visits. Numbers needed to treat were 4.3 and 4.4. Partial clearance rates of at least 50% were reported for 78.4% and 74.0% of patients in the sinecatechins ointment 15% and 10% groups compared with 51.5% of vehicle patients. During follow-up, recurrence of any wart was observed in 6.5%, 8.3%, and 8.8% in the sinecatechins ointment 15% group, sinecatechins ointment 10% group, and vehicle patients, respectively. A total of 3.7%, 8.3%, and 0.0% developed new warts, respectively. A total of 87.7% and 87.3% of patients in the sinecatechins ointment 15% and 10% groups, and 72.1% of vehicle patients experienced application site reactions; 49.2%, 46.2%, and 65.4% of those, respectively, were mild or moderate. CONCLUSION: Topical sinecatechins ointments 15% and 10% are effective and well-tolerated in the treatment of anogenital warts. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00449982. LEVEL OF EVIDENCE: I.  相似文献   
19.
BACKGROUND: Giant myomas of the uterus are uncommon, particularly in developed countries. CASE: This report illustrates a case of a woman with a bilobated giant myoma of the uterus weighed in total 27.7 kg. The patient had an abdominal distension first noted 18 months before and the personal history evidenced difficulties in walking and tiredness. Abdominal hysterectomy and bilateral salpingo-oophorectomy were carried out. CONCLUSIONS: The knowledge of the different clinical manifestation of these myomas may allow to face that with adequate perioperative care, in order to assure a carefully and successfully surgery, although sometimes a benign pathology may be not easy to suspect in a first time.  相似文献   
20.
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