全文获取类型
收费全文 | 34254篇 |
免费 | 2378篇 |
国内免费 | 214篇 |
专业分类
耳鼻咽喉 | 473篇 |
儿科学 | 581篇 |
妇产科学 | 590篇 |
基础医学 | 4628篇 |
口腔科学 | 913篇 |
临床医学 | 3228篇 |
内科学 | 7489篇 |
皮肤病学 | 757篇 |
神经病学 | 2525篇 |
特种医学 | 1502篇 |
外科学 | 4776篇 |
综合类 | 902篇 |
现状与发展 | 1篇 |
一般理论 | 27篇 |
预防医学 | 2275篇 |
眼科学 | 965篇 |
药学 | 2488篇 |
中国医学 | 182篇 |
肿瘤学 | 2544篇 |
出版年
2023年 | 323篇 |
2022年 | 675篇 |
2021年 | 1225篇 |
2020年 | 657篇 |
2019年 | 924篇 |
2018年 | 1093篇 |
2017年 | 787篇 |
2016年 | 923篇 |
2015年 | 1168篇 |
2014年 | 1489篇 |
2013年 | 1698篇 |
2012年 | 2696篇 |
2011年 | 2612篇 |
2010年 | 1471篇 |
2009年 | 1345篇 |
2008年 | 1989篇 |
2007年 | 2025篇 |
2006年 | 1954篇 |
2005年 | 1942篇 |
2004年 | 1661篇 |
2003年 | 1385篇 |
2002年 | 1203篇 |
2001年 | 648篇 |
2000年 | 605篇 |
1999年 | 517篇 |
1998年 | 285篇 |
1997年 | 223篇 |
1996年 | 172篇 |
1995年 | 179篇 |
1994年 | 151篇 |
1993年 | 132篇 |
1992年 | 207篇 |
1991年 | 208篇 |
1990年 | 183篇 |
1989年 | 175篇 |
1988年 | 165篇 |
1987年 | 187篇 |
1986年 | 161篇 |
1985年 | 136篇 |
1984年 | 125篇 |
1983年 | 116篇 |
1982年 | 88篇 |
1981年 | 55篇 |
1980年 | 62篇 |
1979年 | 91篇 |
1977年 | 63篇 |
1976年 | 51篇 |
1974年 | 51篇 |
1970年 | 51篇 |
1969年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Primary care referrals for lumbar spine radiography: diagnostic yield and clinical guidelines. 下载免费PDF全文
William Hollingworth Christopher J Todd Hugh King Tony Males Adrian K Dixon Kanti R Karia Ann Louise Kinmonth 《The British journal of general practice》2002,52(479):475-480
BACKGROUND: Primary care requests for radiographs of the lumbar spine have come under increasing scrutiny. Guidelines aiming to reduce unnecessary radiographs by limiting referrals to patients at high risk of serious disease have been widely distributed. Trial evidence suggests that guidelines can reduce radiography referrals. It is not clear whether this reduction has been achieved in routine practice. AIM: This study, using routine data, was conducted to measure trends in pnmary care referrals for lumbar spine radiography at two hospitals between 1994 and 1999. DESIGN OF STUDY: Analysis of primary care requests for lumbar spine radiography from computerised records. SETTING: Addenbrooke's Hospital, Cambridge (1 July 1994 to 30 June 1999), and Ipswich General Hospital (1 July 1995 to 30 June 1999), United Kingdom. METHOD: All primary care requests for lumbar radiography were identified electronically from computerised information systems. A random sample of 2100 radiography reports were classified according to clinical importance. These classifications were used to examine whether the proportion of radiographs demonstrating potentially more serious findings had increased between 1994 and 1999. RESULTS: There was no evidence that primary care referrals for radiography of the lumbar spine had decreased between 1994 and 1999 at either hospital. General practitioners did not progressively refer more high-risk patients for lumbar radiography. Only a small proportion of patients had important radiographic findings that might warrant specialist referral or specific therapy. CONCLUSION: The implementation of diagnostic guidelines offers much to the NHS. However in these two hospitals, the reduction in radiograph utilisation evident in trials was not achieved. Guideline development is a resource intensive process; distribution must be supported by more effective implementation strategies. 相似文献
52.
Ohne Zusammenfassung 相似文献
53.
54.
Kallol Ray Chaudhuri Pablo Martinez-Martin Anthony H V Schapira Fabrizio Stocchi Kapil Sethi Per Odin Richard G Brown William Koller Paolo Barone Graeme MacPhee Linda Kelly Martin Rabey Doug MacMahon Sue Thomas William Ondo David Rye Alison Forbes Susanne Tluk Vandana Dhawan Annette Bowron Adrian J Williams Charles W Olanow 《Movement disorders》2006,21(7):916-923
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals. 相似文献
55.
Alexandre Castro-Caldas Paul Delwaide Wolfgang Jost Marcelo Merello Adrian Williams Paolo Lamberti Miguel Aguilar Susanna Del Signore Pierre Cesaro 《Movement disorders》2006,21(4):500-509
Dopamine agonists have been recommended as early treatment for Parkinson's disease (PD), alone or combined with levodopa. Piribedil is a non-ergot selective D(2)/D(3) agonist with alpha(2) antagonist properties shown to be effective in the treatment of PD. This 12-month international, randomized, double-blind trial aimed to assess the efficacy of piribedil 150 mg versus bromocriptine 25 mg, in early combination with levodopa in Stage I to III PD patients. Motor efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS III, Items 18-31) as improvement from baseline. Response rate was defined as a 30% improvement. Among the 425 randomly assigned patients, 178 were also included in a substudy on cognitive follow-up evaluated by a dysexecutive syndrome oriented battery. A relevant improvement in UPDRS III over the 12-month study duration was observed both in the piribedil and bromocriptine groups (-7.9 +/- 9.7 points from baseline versus -8.0 +/- 9.5; not significant [n.s.]) with a response rate of 58.4% and 55.3% (n.s.), respectively. Piribedil and bromocriptine resulted in similar improvement on all UPDRS III subscores. Piribedil patients required less levodopa dose increase than those on bromocriptine. Cognitive performance remained generally unchanged in both groups, with a significant effect of piribedil limited to the Wisconsin Card Sorting Test. An overall good tolerability of piribedil was observed. Early combination of piribedil 150 mg with levodopa resulted in significant long-term improvement of all motor symptoms in PD patients insufficiently controlled by levodopa alone. Taking into account both efficacy and acceptability in the long-term, piribedil proved in this bromocriptine controlled study to be an effective and safe treatment for PD. 相似文献
56.
Herschman Harvey R.; Lim Robert W.; Brankow David W.; Fujiki Hirota 《Carcinogenesis》1989,10(8):1495-1498
Okadaic acid (OA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)are both potent tumor promoters in a mouse skin carcinogenesisexperiment. OA was much more toxic than TPA for murine embryocell lines such as Swiss 3T3 cells or C3H10T? cells. TPA isa potent mitogen for 3T3 cells; in contrast OA was unable tostimulate DNA synthesis in these cells. TPA induces a familyof primary response genes, the TPA induced sequence (TIS) genes,in a wide variety of cells. Although OA induced modest levelsof TIS mRNA expression, the time course of the induction ofTIS1 and TIS8 mRNA was delayed when compared to induction byTPA or peptide mitogeas such as fibroblast growth factor (FGF).In addition TPA-mediated down-regulation of protein kinase Cattenuated TIS gene induction by OA, but not by FGF. 相似文献
57.
We evaluated the effects of isoflurane anaesthesia and induced hypotension in 33 neurosurgical patients by electrocardiographic monitoring and serial cardiac enzyme measurements. An electrocardiogram (ECG) and serum enzymes were obtained preoperatively, intraoperatively and postoperatively in the recovery room and for three consecutive days. ECG leads II, V1 and V5 were monitored continuously during anaesthesia. Patients who had had a subarachnoid haemorrhage and a high incidence of abnormal preoperative ECG (42 per cent). Ten patients developed ECG changes intraoperatively, but these changes were unrelated to isoflurane-induced hypotension. Fifty-three per cent of patients developed an abnormal postoperative ECG. These abnormalities consisted mostly of nonspecific ST segment or T wave changes. At no time was there an elevation in cardiac enzyme activity. We found that nonspecific ECG changes are relatively common in patients undergoing vascular neurosurgical procedures. There was no enzymatic evidence of myocardial infarction and we can only speculate that these ECG changes are related to intracranial surgical manipulation. 相似文献
58.
59.
60.
H C Chung H Y Lim E H Koh J H Kim J K Roh I S Park J S Min K S Lee J K Youn B S Kim 《Yonsei medical journal》1992,33(2):143-152
Recently, metastasis to N3 lymph nodes group was regarded as distant metastasis by the new TNM staging system due to poor overall survival. However, the 5-year overall survival rate of patients with metastasis to N3 groups was 34.5% after curative surgery. Moreover, in patients with metastasis to lymph node subgroups of #12, #13, #14, the overall 5-year survival rate increased upto 47.2% after curative resection and adjuvant chemotherapy. This was similar to that of the patients with metastasis to N1 and N2 lymph nodes groups. But in these highly tumor burden states, no survival benefit was found with the addition of immunotherapy to chemotherapy as we achieved in stage II and III. Therefore, we suggest that, at least, metastasis to #12, #13, #14 lymph nodes subgroups should not be categorized as a distant metastasis. And in these situations, active curative radical surgery with extended lymphadenectomy and adjuvant chemotherapy are recommended. 相似文献