全文获取类型
收费全文 | 1350篇 |
免费 | 98篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 22篇 |
妇产科学 | 14篇 |
基础医学 | 185篇 |
口腔科学 | 2篇 |
临床医学 | 141篇 |
内科学 | 347篇 |
皮肤病学 | 21篇 |
神经病学 | 106篇 |
特种医学 | 47篇 |
外科学 | 216篇 |
综合类 | 19篇 |
预防医学 | 119篇 |
眼科学 | 15篇 |
药学 | 84篇 |
中国医学 | 1篇 |
肿瘤学 | 107篇 |
出版年
2023年 | 16篇 |
2022年 | 20篇 |
2021年 | 34篇 |
2020年 | 20篇 |
2019年 | 43篇 |
2018年 | 50篇 |
2017年 | 32篇 |
2016年 | 41篇 |
2015年 | 35篇 |
2014年 | 59篇 |
2013年 | 89篇 |
2012年 | 111篇 |
2011年 | 127篇 |
2010年 | 77篇 |
2009年 | 68篇 |
2008年 | 64篇 |
2007年 | 81篇 |
2006年 | 73篇 |
2005年 | 51篇 |
2004年 | 56篇 |
2003年 | 46篇 |
2002年 | 43篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 11篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1975年 | 4篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1948年 | 3篇 |
1947年 | 3篇 |
排序方式: 共有1455条查询结果,搜索用时 15 毫秒
61.
Foley R 《Social science & medicine (1982)》2002,55(1):79-96
Informal carers save the state's health and social care services billions of pounds each year. The stresses associated with caring have given rise to a number of short-term care services to provide respite to carers. The Carers (Recognition & Services) Act of 1995 identified formally for the first time, the important role that unpaid carers provide across the community in Britain. The planning of combined health and social care services such as short-term care is a less developed application of geographical information systems (GIS) and this paper examines awareness and application issues associated with the potential use of GIS to manage short-term care service planning for informal carers in East Sussex. The assessment of GIS awareness was carried out by using a semi-structured questionnaire approach and interviewing key local managers and planners across a number of agencies. GIS data was gathered from the agencies and developed within a GIS to build up a set of spatial databases of available services, location of users and additional geo-demographic and topographic information. The output from this system development was presented in turn at workshops with agencies associated with short-term care planning as well as users to help assess their perspectives on the potential use and value of GIS. A renewed emphasis on a planned approach to health care coupled with integrated/ joint working with social care creates a need for new approaches to planning. The feedback from planners and users, suggested that a number of key data elements attached to data-sharing may prove to be simultaneously progressive yet problematic, especially in the areas of ethics, confidentiality and informed consent. A critical response to the suitability of GIS as a tool to aid joint health and social care approaches is incorporated within a final summary. 相似文献
62.
BACKGROUND/AIMS: The blood pressure, the most influencing factor in cardiovascular disease in end-stage renal failure patients, follows a seasonal variation during the year. Since vitamin D(3) is known to be related to sun exposure, we wanted to evaluate the putative participation of the vitamin D(3) metabolism in blood pressure modifications. METHODS: We studied 22 stable hemodialysis patients (11 females and 11 males, mean age +/- SD 56 +/- 1 year) who had been continuously treated in our dialysis unit for more than 1 year between 1994 and 1997 and did not receive pulse vitamin D(3) treatment. Supine systolic and diastolic blood pressures were measured before every dialysis session (>12,000 measurements) and the intact parathormone (iPTH), 25-hydroxyvitamin D(3) [25(OH)D(3)], and 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] levels every 3 months (>300 determinations). The mean values of blood pressure per season and per patient were taken for analysis using a 4-year longitudinal study design. RESULTS: The blood pressure varied during the years studied following a seasonal trend. It was highest during autumn and tended to decrease during spring and warmer months. Systolic as well as diastolic blood pressures were significantly correlated with the 25(OH)D(3) levels (p = 0.0291 and p = 0.0327, respectively). No correlation was observed between blood pressure and 1,25(OH)(2)D(3) or iPTH levels. CONCLUSION: There is a link between blood pressure and 25(OH)D(3) level. This interrelation is not secondary to a iPTH modulation. Although it cannot be excluded that vitamin D(3) and blood pressure vary following a third factor with seasonal variations, since vitamin D(3) varies during the year, mainly following sun exposure, we suggest that vitamin D(3) is one of the factors participating in the seasonal variation of the blood pressure. Other factors known to control the blood pressure and particularly the extracellular volume overload may also participate. 相似文献
63.
64.
In recent years, a number of phase III clinical trials have reported median survival times approaching 20 months using modern combination chemotherapy for metastatic colorectal cancer (CRC). Despite the advances in systemic therapy, this approach is still considered palliative because long-term survival or cure is extremely rare. Surgery or the use of ablative techniques may result in prolonged survival for patients with liver metastases, but only a minority of cases are suitable for local therapy. Hepatic arterial infusion (HAI) therapy involves local delivery of drug to liver metastases, resulting in higher intrahepatic drug levels and a consequent doubling in response rates compared with systemic chemotherapy. Despite higher response rates, demonstrating a survival advantage for HAI has been more challenging. Recently, a number of studies have been published that appear to address some of the inadequacies of earlier trials and have demonstrated encouraging results. This review assimilates the current data on HAI for CRC and includes an assessment of new chemotherapeutic agents delivered via HAI, neoadjuvant HAI, HAI combined with systemic chemotherapy, the use of HAI for early-stage colorectal cancer, and future trials. Continued progress in the field of HAI therapy may reduce the morbidity and mortality associated with CRC, so continued research in this area should be encouraged. 相似文献
65.
Dromigny JA Jambou R Scott CS Perrier-Gros-Claude JD 《Transactions of the Royal Society of Tropical Medicine and Hygiene》2005,99(6):430-439
This prospective study evaluated the efficiency of automated depolarization analysis for recognition of unsuspected malaria by haemozoin detection during routine full blood count (FBC) screening of 676 randomly selected out-patients in a malaria hypoendemic area of Senegal. An additional 123 patients with clinically suspected malaria were studied for comparison. Of the 799 samples, 648 (81.1%) were categorized as malaria-negative, 83 (10.4%) as malaria-positive, and 68 as treated (early convalescence) or subclinical malaria (indirect evidence of infection). At a discrimination level of one or more atypical pigment-containing monocytes (PCM), negative and positive agreement was found to be 95.6% and 91.6% respectively for all malaria-negative and parasite-positive samples combined. Increasing the discriminator to two or more PCM events improved the overall agreement to 97.5%. Multivariate analysis showed that the only significant risk factor for the presence of PCM (odds ratio>200) was malaria infection. In the randomly selected group of 676 patients, 41 unsuspected cases of malaria infection were detected using the panel of reference diagnostic tests, and 37 (90.2%) of these had atypical PCM. The detection of clinically unrecognized malaria infection as part of a routine FBC procedure is a potentially useful extended application for laboratories in countries with endemic malaria. 相似文献
66.
Cahill RA McGreal GT Crowe BH Ryan DA Manning BJ Cahill MR Redmond HP 《Journal of the American College of Surgeons》2005,200(4):564-73; quiz A59-61
BACKGROUND: Aspirin has a significant effect on hemostasis, so it is often recommended that patients taking aspirin discontinue treatment before elective surgery. While off aspirin, these patients may be at risk of thrombosis. The optimum period of time that aspirin should be withheld is controversial. The aim of this study was to establish the duration of the antihemostatic effect of prolonged aspirin therapy. STUDY DESIGN: In a prospective study, 51 healthy volunteers were randomly assigned into 3 groups, each receiving an identical tablet for 14 days. One group received a placebo tablet; individuals in the other two groups received either 75 mg or 300 mg of aspirin once a day. Template bleeding times and specific platelet function testing (using the PFA-100; Dade Behring) were carried out on subjects before therapy and again after its completion until they returned to baseline. RESULTS: Thirty-eight volunteers complied sufficiently with the protocol to provide useful results. All bleeding times normalized within 96 hours and all platelet function tests within 144 hours after stopping aspirin. There was no demonstrable hemostatic defect in any volunteer persisting by or beyond the sixth day after treatment cessation. There was no apparent difference in duration of effect between those taking either 75 mg or 300 mg of aspirin. CONCLUSIONS: This study uses sensitive measures of platelet function to demonstrate the duration of increased bleeding tendency after withdrawal of aspirin therapy. It supports discontinuation of aspirin therapy 5 days before elective surgery (with the operation being performed on the sixth day). 相似文献
67.
Suresh K Rodriguez-Lecompte JC Gauldie J Foley R 《Hematology (Amsterdam, Netherlands)》2005,10(3):189-203
Chronic lymphocytic leukemia (CLL) results from the relentless accumulation of small mature, slowly dividing, monoclonal B-lymphocytes. The clinical course is heterogeneous, some patients with aggressive form of the disease progressing rapidly with early death while others exhibit a more stable, possibly, non-progressing indolent type of the disease lasting many years. Despite progress in modern treatment modalities, relapse invariably occurs and disease still remains incurable. The clinical management of CLL is therefore challenging and considerable effort has been directed towards novel therapeutic strategies aimed at reducing minimal residual disease which can increase remission duration. Recent insight into the role of dendritic cells (DCs) as pivotal antigen presenting cells that initiate immune responses may provide the basis for generating more specific and effective immune responses. Ex-vivo modified and monocyte-derived DCs represents a promising approach within the context of CLL. However, understanding the relationship between DCs and the cellular immune response is crucial in devising strategies for manipulating immune responses. After a brief survey of general properties of DCs, this review focuses on the different approaches exploiting monocyte-derived DCs in CLL, which may help to design novel strategies for phase-I clinical trials. 相似文献
68.
Three dimensional reconstruction of a human breast carcinoma using routine laboratory equipment and immunohistochemistry 总被引:2,自引:0,他引:2
Kurien T Boyce RW Paish EC Ronan J Maddison J Rakha EA Green AR Ellis IO 《Journal of clinical pathology》2005,58(9):968-972
AIMS: To establish a three dimensional reconstruction of an invasive breast carcinoma using basic laboratory equipment to evaluate and characterise the spatial arrangement of the parenchymal cells of the breast. METHODS: One hundred and twenty eight sequential 4 microm sections (20 microm apart) of the tumour were stained immunohistochemically with an epithelial specific marker (AE1/AE3) or tumour specific marker (c-erbB-2) to reconstruct two different three dimensional images of the normal and malignant parenchymal cells. Sections were digitally imaged using a microscope, scanner, and digital camera linked to a conventional personal computer. Accurate alignment of the digitalised images was carried out using a semiautomatic graphical method of manual interaction, using the cross correlation coefficient as a goodness of fit measure, and an automatic search algorithm using the Fibonacci search algorithm for automatic alignment. The volume was reconstructed using maximum, minimum point projection and "back to front" opacity blending. RESULTS: The quality of the reconstructed images was distinct and perfect, providing a comprehensive and explicit view of the normal and malignant parenchymal tissues of the breast that is not possible by viewing two dimensional histological sections. Specifically, this approach showed the spatial arrangement of the tumour cells and their relation to the surrounding tissues at a high resolution. CONCLUSION: This simple and reproducible approach enables the spread and infiltration of invasive carcinoma to be understood and could also be used to analyse the spatial relation between atypical hyperplastic and malignant in situ lesions of the breast. 相似文献
69.
Muscle tissue is highly sensitive to drugs and toxins because ot its high metabolic activity and potential sites for disruption of energy-producing pathways. Early recognition of toxic myopathies is important, as they potentially are reversible on removal of the offending toxin, with greater likelihood of complete resolution the sooner this is achieved. Clinical features range from mild muscle pain and cramps to severe weakness with rhabdomyolysis, renal failure, and even death. The pathogenic bases can be multifactorial. This article reviews drugs responsible for common types of toxic myopathy and their clinical and histopathologic features and illustrates possible underlying cellular mechanisms. 相似文献
70.
Bae KT McDermott R Gierada DS Heiken JP Nolte MA Takahashi N Hong C 《Academic radiology》2004,11(1):61-68
Rationale and Objectives. The feasibility of using gadolinium contrast medium for computed tomography angiography (CTA) in multi-detector row computed tomography and the effect of contrast medium dilution was investigated.Materials and Methods. Three pigs were each scanned in multiple sessions with injections of non-dilute and dilute contrast medium at a dose of 0.3 mmol/kg body weight. Non-spiral dynamic scanning at a fixed mid-abdominal aortic level and thoracoabdominal CTA were performed.Results. The magnitude of peak aortic enhancement was not significantly different between dilute and non-dilute contrast medium injections (P = .88), but the former showed earlier enhancement (mean of 2.3 seconds sooner, P < .01) than the latter. CT angiography with gadolinium contrast medium showed much lower enhancement than iodine contrast medium, but small vessels were readily identifiable.Conclusion. Gadolinium contrast medium combined with multi-detector row computed tomography may provide clinically useful CTA. Dilution of contrast medium shortens the enhancement time but has little effect on the magnitude. 相似文献