全文获取类型
收费全文 | 785篇 |
免费 | 47篇 |
国内免费 | 34篇 |
专业分类
儿科学 | 40篇 |
妇产科学 | 10篇 |
基础医学 | 96篇 |
口腔科学 | 25篇 |
临床医学 | 117篇 |
内科学 | 196篇 |
皮肤病学 | 16篇 |
神经病学 | 17篇 |
特种医学 | 128篇 |
外国民族医学 | 1篇 |
外科学 | 58篇 |
综合类 | 15篇 |
预防医学 | 36篇 |
眼科学 | 3篇 |
药学 | 75篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 14篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 26篇 |
2013年 | 36篇 |
2012年 | 28篇 |
2011年 | 27篇 |
2010年 | 32篇 |
2009年 | 39篇 |
2008年 | 22篇 |
2007年 | 44篇 |
2006年 | 30篇 |
2005年 | 18篇 |
2004年 | 28篇 |
2003年 | 13篇 |
2002年 | 28篇 |
2001年 | 9篇 |
2000年 | 16篇 |
1999年 | 25篇 |
1998年 | 35篇 |
1997年 | 36篇 |
1996年 | 38篇 |
1995年 | 24篇 |
1994年 | 34篇 |
1993年 | 22篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 20篇 |
1988年 | 24篇 |
1987年 | 12篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1973年 | 2篇 |
排序方式: 共有866条查询结果,搜索用时 0 毫秒
71.
72.
Isabelle Laffont Claude Dumas Delphine Pozzi Maria Ruquet Anne Claire Tissier Frédéric Lofaso Olivier Dizien 《Journal of rehabilitation medicine》2007,39(5):399-404
OBJECTIVE: The aim of this study was to evaluate a speech synthesizer with respect to patterns of use and satisfaction, during a 2-month trial at home, and the usefulness of the word prediction function. DESIGN: Prospective study. PARTICIPANTS: Of the 24 patients with severe dysarthria recruited, 10 completed the study. Five patients had cerebral palsy, 3 amyotrophic lateral sclerosis, one locked-in syndrome, and one anoxic brain damage. Mean age was 32 (standard deviation 21) years (range 9-66 years). METHODS: Each participant received 10 hours of training with the device (Dialo) and then used it at home for 2 months. The main outcome measures were: level of use recorded by the device, Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) satisfaction score (maximum = 5), and time needed to take dictations of standard-dictionary and personal-dictionary words with and without word prediction. RESULTS: Level of use varied widely across participants. Overall satisfaction at the end of the home trial was high, with a mean QUEST score of 3.4 (SD 1) and was related to the level of use of the device. Level of satisfaction at the end of the training session could not predict the level of use at home. No significant differences were found in dictation-taking times with and without word prediction. However, 6 of the 10 patients took dictation faster with than without word prediction. CONCLUSION: This study provides the first evidence supporting the benefits of a speech synthesizer used at home for several weeks. Word prediction is useful for some patients even if increase in dictation speed did not reach significance. 相似文献
73.
WH Belloso LC Orellana B Grinsztejn JS Madero A La Rosa VG Veloso J Sanchez R Ismerio Moreira B Crabtree‐Ramirez O Garcia Messina MB Lasala J Peinado MH Losso 《HIV medicine》2010,11(9):554-564
Objective
Acquired immune deficiency appears to be associated with serious non‐AIDS (SNA)‐defining conditions such as cardiovascular disease, liver and renal insufficiency and non‐AIDS‐related malignancies. We analysed the incidence of, and factors associated with, several SNA events in the LATINA retrospective cohort.Materials and methods
Cases of SNA events were recorded among cohort patients. Three controls were selected for each case from cohort members at risk. Conditional logistic models were fitted to estimate the effect of traditional risk factors as well as HIV‐associated factors on non‐AIDS‐defining conditions.Results
Among 6007 patients in follow‐up, 130 had an SNA event (0.86 events/100 person‐years of follow‐up) and were defined as cases (40 with cardiovascular events, 54 with serious liver failure, 35 with non‐AIDS‐defining malignancies and two with renal insufficiency). Risk factors such as diabetes, hepatitis B and C virus coinfections and alcohol abuse showed an association with events, as expected. The last recorded CD4 T‐cell count prior to index date (P=0.0056, with an average difference of more than 100 cells/μL) and area under the CD4 cell curve in the year previous to index date (P=0.0081) were significantly lower in cases than in controls. CD4 cell count at index date was significantly associated with the outcome after adjusting for risk factors.Conclusions
The incidence and type of SNA events found in this Latin American cohort are similar to those reported in other regions. We found a significant association between immune deficiency and the risk of SNA events, even in patients under antiretroviral treatment. 相似文献74.
G Morris-Stiff J D'Souza S Raman S Paulvannan MH Lewis 《Annals of the Royal College of Surgeons of England》2009,91(8):637-640
INTRODUCTION
The aims of this study were to audit results of a 10-year experience of surgery for acute limb ischaemia (ALI) in terms of limb salvage and mortality rates, and to compare results with a historical published series from our unit.PATIENTS AND METHODS
All emergency operations performed during the period 1993–2003 were identified from theatre registers and patient notes reviewed to determine indications for, and outcome of, surgery. Data were compared to a similar cohort who underwent surgery from 1980 to 1990.RESULTS
There was a 33% increase in workload from 87 to 116 patients between the two time periods. The number of patients with idiopathic ALI reduced (24% versus 4%; P < 0.05), and there were fewer smokers (71% versus 39%; P < 0.05) and a greater number of claudicants (17% versus 35%; P < 0.05) in those treated from 1993–2003. Latterly, more patients underwent pre-operative heparinisation (33% versus 80%; P < 0.05), received prophylactic antibiotics (14% versus 63%; P < 0.05), and had anaesthetic presence in theatre (46% versus 88%; P < 0.05). There was also a reduction in local anaesthetic procedures (80% versus 41%; P < 0.05). Despite increased pre-operative (15% versus 47%; P < 0.05) and on-table imaging (0% versus 16%; P < 0.05) technical success did not improve. Whilst complication rates were identical at 62%, there were fewer cardiovascular complications in the recent cohort. The 30-day mortality rate for embolectomy fell from 45% to 33%. Multivariate analysis revealed age > 70 years, prolonged symptom duration, ASA score ≥ III, lack of prophylactic antibiotics, absence of an anaesthetist, and operations performed under local anaesthetic to be associated with increased risk of mortality. Factors adversely affecting limb salvage included prolonged duration from symptom onset to operation, and a history of claudication or smoking.CONCLUSIONS
Despite improvements in pre- and peri-operative management, arterial embolectomy/thrombectomy remains a procedure with a high morbidity and mortality. Further attempts to improve outcome must be directed at early diagnosis and referral as delay from symptom onset to surgery is a major determinant of outcome. 相似文献75.
Vita W Jongen Thijs Reyniers Zorah MH Ypma Maarten F Schim van der Loeff Udi Davidovich Hanne ML Zimmermann Liza Coyer Mark AM van den Elshout Henry JC de Vries Kristien Wouters Tom Smekens Bea Vuylsteke Maria Prins Marie Laga Elske Hoornenborg 《Journal of the International AIDS Society》2021,24(8)
IntroductionDaily and event‐driven PrEP are both efficacious in reducing the risk for HIV infection. However, the practice of event‐driven PrEP (edPrEP) is less well studied, in particular when provided as an alternative to daily PrEP. We studied regimen preferences and switches, and sexually transmitted infection (STI) incidence.MethodsWe analysed pooled data from two prospective cohort studies among MSM: Be‐PrEP‐ared, Belgium and AMPrEP, the Netherlands. In both projects, participants could choose between daily and edPrEP at three‐monthly study visits, when they were also screened for sexually transmitted infections including hepatitis C (HCV). We assessed the proportion choosing each regimen, and the determinants of choosing edPrEP at baseline. Additionally, we compared the incidence rates (IRs) of HCV, syphilis and chlamydia or gonorrhoea between regimens using Poisson regression. The study period was from 3 August 2015 until 24 September 2018.Results and discussionWe included 571 MSM, of whom 148 (25.9%) chose edPrEP at baseline. 31.7% of participants switched regimen at least once. After 28 months, 23.5% used edPrEP. Older participants (adjusted odds ratio (aOR) = 1.38 per 10 years, 95% confidence interval (CI) = 1.15 to 1.64) and those unemployed (aOR = 1.68, 95% CI = 1.03 to 1.75) were more likely to initially choose edPrEP. IR of HCV and syphilis did not differ between regimens, but the IR of chlamydia/gonorrhoea was higher among daily users (adjusted incidence rate ratio = 1.61, 95% CI = 1.35 to 1.94).ConclusionsA quarter of participants chose edPrEP at baseline and at 28 months this proportion was similar. Although the IR of HCV and syphilis were similar in the two regimens, the lower incidence of chlamydia and gonorrhoea among edPrEP users may suggest that less frequent STI testing of this group could be considered. 相似文献
76.
77.
78.
L. Y. M. Cheung K. Rizzoti R. Lovell‐Badge P. R. Le Tissier 《Journal of neuroendocrinology》2013,25(4):391-401
The Notch signalling pathway ligand delta‐like 1 homologue (Dlk1, also named Pref1) is expressed throughout the developing pituitary and becomes restricted to mostly growth hormone (GH) cells within the adult gland. We have investigated the role of Dlk1 in pituitary development and function from late embryogenesis to adulthood using a mouse model completely lacking the expression of Dlk1. We confirm that Dlk1‐null mice are shorter and weigh less than wild‐type littermates from late gestation, at parturition and in adulthood. A loss of Dlk1 leads to significant reduction in GH content throughout life, whereas other pituitary hormones are reduced to varying degrees depending on sex and age. Both the size of the pituitary and the proportion of hormone‐producing cell populations are unchanged, suggesting that there is a reduction in hormone content per cell. In vivo challenge of mutant and wild‐type littermates with growth hormone‐releasing hormone and growth hormone‐releasing hexapeptide shows that reduced GH secretion is unlikely to account for the reduced growth of Dlk1 knockout animals. These data suggest that loss of Dlk1 gives rise to minor pituitary defects manifesting as an age‐ and sex‐dependent reduction in pituitary hormone contents. However, Dlk1 expression in other tissue is most likely responsible for the weight and length differences observed in mutant animals. 相似文献
79.
80.