全文获取类型
收费全文 | 1779篇 |
免费 | 108篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 41篇 |
妇产科学 | 24篇 |
基础医学 | 191篇 |
口腔科学 | 56篇 |
临床医学 | 117篇 |
内科学 | 286篇 |
皮肤病学 | 24篇 |
神经病学 | 154篇 |
特种医学 | 258篇 |
外国民族医学 | 1篇 |
外科学 | 179篇 |
综合类 | 45篇 |
预防医学 | 157篇 |
眼科学 | 108篇 |
药学 | 101篇 |
中国医学 | 2篇 |
肿瘤学 | 154篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 21篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 36篇 |
2017年 | 19篇 |
2016年 | 34篇 |
2015年 | 25篇 |
2014年 | 50篇 |
2013年 | 62篇 |
2012年 | 90篇 |
2011年 | 80篇 |
2010年 | 49篇 |
2009年 | 50篇 |
2008年 | 76篇 |
2007年 | 102篇 |
2006年 | 84篇 |
2005年 | 73篇 |
2004年 | 60篇 |
2003年 | 59篇 |
2002年 | 61篇 |
2001年 | 66篇 |
2000年 | 55篇 |
1999年 | 53篇 |
1998年 | 41篇 |
1997年 | 51篇 |
1996年 | 40篇 |
1995年 | 35篇 |
1994年 | 32篇 |
1993年 | 25篇 |
1992年 | 24篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 40篇 |
1988年 | 25篇 |
1987年 | 34篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 16篇 |
1983年 | 22篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 18篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 9篇 |
1972年 | 5篇 |
1970年 | 7篇 |
排序方式: 共有1902条查询结果,搜索用时 15 毫秒
121.
122.
BACKGROUND: Routine screening of high-risk elderly people for early cognitive impairment is constrained by the limitations of currently available cognitive function tests. The Telephone Interview of Cognitive Status is a novel instrument for assessment of cognitive function that can be administered in person or by telephone. OBJECTIVE: To evaluate the determinants and utility of TICS-M (13-item modified version) for assessment of cognitive function in healthy elderly people. METHODS: The utility of TICS-M was compared with more widely used MMSE and CAMCOG in a cross-sectional survey of 120 older (62 to 89 years) UK adults. RESULTS: The TICS-M cognitive test scores (27.97, SD 4.15) were normally distributed in contrast with those for MMSE and CAMCOG that had a negatively skewed distribution. TICS-M scores were inversely correlated with age (r = -0.21) and with the NART fullscale IQ (r = -0.35), but were independent of years of education in this cohort. TICS-M was highly correlated with MMSE (r = 0.57) and with CAMCOG (r = 0.62) scores. The time required to complete the test is comparable to MMSE and substantially less than CAMCOG. CONCLUSIONS: The normal distribution of TICS-M test scores suggest that this test is less constrained by the ceiling effect which limits the utility of MMSE and CAMCOG test scores in detecting early cognitive impairment. TICS-M is an appropriate instrument to assess cognitive function in both research and in clinical practice. 相似文献
123.
Cost-effectiveness analysis of pneumococcal vaccination for elderly individuals in The Netherlands 总被引:2,自引:0,他引:2
OBJECTIVE: To assess the cost effectiveness (net costs per life year gained) of pneumococcal vaccination of elderly individuals aged 65 years and over in The Netherlands. DESIGN AND SETTING: A pharmacoeconomic analysis was conducted from the healthcare perspective in The Netherlands. The gender- and age-specific modelling framework linked epidemiological aspects of invasive pneumococcal disease (e.g. incidence, mortality, life years lost) to vaccination and hospital resource use. To derive 90% confidence limits for net costs per life year gained a stochastic analysis was performed. INTERVENTION: Pneumococcal vaccination in the elderly with the 23-valent vaccine. Effectiveness of the vaccine in preventing invasive pneumococcal disease was derived from international studies. MAIN OUTCOME MEASURES AND RESULTS: Pneumococcal vaccination in the elderly was not found to be cost saving. At baseline, stochastic and univariate sensitivity analysis net costs per life year gained were estimated to be between 6000 and 16,000 euro (EUR) [EUR1 = 1.1 US dollars; cost level 1995]. A scenario analysis on alternative age-dependent vaccination strategies indicated even higher net costs per life year gained, up to EUR28,000 for vaccinating only those elderly aged 85 years and over. CONCLUSIONS: Pneumococcal vaccination is associated with net costs per life year gained of EUR10,100 (at baseline assumptions). These costs are higher than those for influenza vaccination (EUR5500). Our pharmacoeconomic approach, which needs to be considered in conjunction with social, psychological and budgetary issues, is intended to contribute to rational decision-making in healthcare policy. 相似文献
124.
Relation of impaired fasting and postload glucose with incident type 2 diabetes in a Dutch population: The Hoorn Study 总被引:24,自引:0,他引:24
de Vegt F Dekker JM Jager A Hienkens E Kostense PJ Stehouwer CD Nijpels G Bouter LM Heine RJ 《JAMA》2001,285(16):2109-2113
CONTEXT: Persons with impaired glucose tolerance (IGT) are known to have an elevated risk of developing diabetes mellitus. Less is known about diabetes risk among persons with impaired fasting glucose (IFG) or with normal glucose levels. OBJECTIVE: To determine the incidence of diabetes in relation to baseline fasting and postload glucose levels and other risk factors. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study conducted from October 1989 to February 1992 among 1342 nondiabetic white residents of Hoorn, the Netherlands, aged 50 to 75 years at baseline, in whom fasting plasma glucose (FPG) levels and glucose levels 2 hours after a 75-g oral glucose tolerance test were measured at baseline and at follow-up in 1996-1998. MAIN OUTCOME MEASURES: Cumulative incidence of diabetes, defined according to the diagnostic criteria of the World Health Organization (WHO-1985 and WHO-1999) and the American Diabetes Association (ADA-1997), during a mean follow-up of 6.4 years, compared among participants with IFG, IGT, and normal glucose levels at baseline. RESULTS: The cumulative incidence of diabetes was 6.1%, 8.3%, and 9.9% according to the WHO-1985, ADA, and WHO-1999 criteria, respectively. The cumulative incidence of diabetes (WHO-1999 criteria) for participants with both IFG and IGT was 64.5% compared with 4.5% for those with normal glucose levels at baseline. The odds ratios for diabetes (WHO-1999 criteria), adjusted for age, sex, and follow-up duration, were 10.0 (95% confidence interval [CI], 6.1-16.5), 10.9 (95% CI, 6.0-19.9), and 39.5 (95% CI, 17.0-92.1), respectively, for those having isolated IFG, isolated IGT, and both IFG and IGT. In addition to FPG and 2-hour postload glucose levels (P<.001 for both), the waist-hip ratio also was an important risk factor for developing diabetes (P =.002). CONCLUSION: In this study, the cumulative incidence of diabetes was strongly related to both IFG and IGT at baseline and, in particular, to the combined presence of IFG and IGT. 相似文献
125.
Renal replacement therapy in Europe: the results of a collaborative effort by the ERA-EDTA registry and six national or regional registries. 总被引:16,自引:8,他引:8
P C van Dijk K J Jager F de Charro F Collart R Cornet F W Dekker C Gr?nhagen-Riska R Kramar T Leivestad K Simpson J D Briggs 《Nephrology, dialysis, transplantation》2001,16(6):1120-1129
BACKGROUND: In June 2000 a new ERA-EDTA Registry Office was opened in Amsterdam. This Registry will only collect core data on renal replacement therapy (RRT) through national and regional registries. This paper reports the technical and epidemiological results of a pilot study combining the data from six registries. METHODS: Data from the national renal registries of Austria, Finland, French-Belgium, The Netherlands, Norway, and Scotland were combined. Patients starting RRT between 1980 and 1999 (n=57371) were included in the analyses. Cox proportional hazards regression was used to predict survival. RESULTS: The use of different coding systems for ESRD treatment by the registries made it difficult to merge the data. Incidence and prevalence of RRT showed a continuous increase with a marked variation in rates between countries. The 2-, 5- and 10-year patient survival was 67, 35 and 11% in dialysis patients and 90, 81 and 64% after a first renal allograft. Multivariate analysis showed a slightly better survival on dialysis in the 1990-1994 (RR 0.94, 95% CI 0.90-0.98) and the 1995-1999 cohort (RR 0.88, 95% CI 0.84-0.92) compared to the 1980-1984 cohort. In contrast, there was a much greater improvement in transplant-patient survival, resulting in a 56% reduction in the risk of death within the 1995-1999 cohort (RR 0.44, 95% CI 0.39-0.50) compared to the 1980-1984 cohort. CONCLUSIONS: This study provides support for the feasibility of a "new style" ERA-EDTA registry and the collection of data is now being extended to other countries. The improvement in patient survival over the last two decades has been much greater in transplant recipients than in dialysis patients. 相似文献
126.
127.
Seedat RY Hamilton PD de Jager LP Strydom W Beukes CA 《International journal of pediatric otorhinolaryngology》2000,52(2):177-181
We present a patient with acute sinusitis whose CT scan showed a ring-enhancing lesion within the orbit typical of an orbital subperiosteal abscess. On exploration of the orbit, there was no pus present but a tumour was found, which on histological examination was found to be a rhabdomyosarcoma. The clinical signs and CT characteristics of orbital subperiosteal abscesses and rhabdomyosarcomas are discussed. A ring-enhancing lesion within the orbit on CT scan should not be regarded as being pathognomonic for a subperiosteal abscess and the possibility of other diagnoses should be considered. 相似文献
128.
von Willebrand factor, C-reactive protein, and 5-year mortality in diabetic and nondiabetic subjects: the Hoorn Study 总被引:12,自引:0,他引:12
Jager A van Hinsbergh VW Kostense PJ Emeis JJ Yudkin JS Nijpels G Dekker JM Heine RJ Bouter LM Stehouwer CD 《Arteriosclerosis, thrombosis, and vascular biology》1999,19(12):3071-3078
Increased levels of von Willebrand factor (vWf) and C-reactive protein (CRP) predict cardiovascular mortality in selected populations. It is uncertain whether vWf and CRP predict mortality in a general population and whether vWf and CRP predict mortality through similar pathways. This study investigated the association of vWf and CRP with cardiovascular and all-cause mortality among diabetic and nondiabetic subjects. An age-, sex-, and glucose tolerance-stratified sample (n=631) of a population-based cohort aged 50 to 75 years was followed prospectively for 5 years. After 5 years of follow-up, 58 subjects had died (24 of cardiovascular causes). vWf (>1.56 IU/mL) and CRP (>2.84 mg/L) levels in the upper tertile were associated with, respectively, a 3- and 2-fold increase in cardiovascular mortality after adjustment for age, sex, and glucose tolerance status. Analyses in nondiabetic and diabetic subjects separately gave similar results. After further adjustment for hypertension, levels of HDL cholesterol and triglyceride, smoking habits, ischemic heart disease, and peripheral arterial disease, the relative risks (RRs) were 3.0 (95% CI 1.2 to 7.9) for vWf and 1.4 (95% CI 0.6 to 3.5) for CRP. When both vWf and CRP were included in the latter multivariate analysis, the RRs were 3.0 (95% CI 1.1 to 7.9) for vWf and 1.3 (95% CI 0.5 to 3.4) for CRP. The association between vWf and risk of cardiovascular mortality was independent of blood group (O versus non-O) and, moreover, similar among subjects with different blood groups. Repeating the analyses for all-cause mortality gave similar results for CRP. For vWf, the RR was 2.0 (95% CI 1.1 to 3.5) after adjustment for all other risk factors. Increased levels of vWf are independently associated with cardiovascular and all-cause mortality in both diabetic and nondiabetic subjects. The association between increased levels of CRP and cardiovascular mortality was partly explained by other risk factors. Mutual adjustment of vWf and CRP did not markedly change the results, favoring the hypothesis that vWf and CRP predict mortality through different pathways. 相似文献
129.
C Vrieling L Collette A Fourquet W J Hoogenraad J C Horiot J J Jager M Pierart P M Poortmans H Struikmans M Van der Hulst E Van der Schueren H Bartelink 《International journal of radiation oncology, biology, physics》1999,45(3):677-685
PURPOSE: To evaluate the influence of a radiotherapy boost on the cosmetic outcome after 3 years of follow-up in patients treated with breast-conserving therapy (BCT). METHODS AND MATERIALS: In EORTC trial 22881/10882, 5569 Stage I and II breast cancer patients were treated with tumorectomy and axillary dissection, followed by tangential irradiation of the breast to a dose of 50 Gy in 5 weeks, at 2 Gy per fraction. Patients having a microscopically complete tumor excision were randomized between no boost and a boost of 16 Gy. The cosmetic outcome was evaluated by a panel, scoring photographs of 731 patients taken soon after surgery and 3 years later, and by digitizer measurements, measuring the displacement of the nipple of 3000 patients postoperatively and of 1141 patients 3 years later. RESULTS: There was no difference in the cosmetic outcome between the two treatment arms after surgery, before the start of radiotherapy. At 3-year follow-up, both the panel evaluation and the digitizer measurements showed that the boost had a significant adverse effect on the cosmetic result. The panel evaluation at 3 years showed that 86% of patients in the no-boost group had an excellent or good global result, compared to 71% of patients in the boost group (p = 0.0001). The digitizer measurements at 3 years showed a relative breast retraction assessment (pBRA) of 7.6 pBRA in the no-boost group, compared to 8.3 pBRA in the boost group, indicating a worse cosmetic result in the boost group at follow-up (p = 0.04). CONCLUSIONS: These results showed that a boost dose of 16 Gy had a negative, but limited, impact on the cosmetic outcome after 3 years. 相似文献
130.