全文获取类型
收费全文 | 25720篇 |
免费 | 1456篇 |
国内免费 | 122篇 |
专业分类
耳鼻咽喉 | 300篇 |
儿科学 | 570篇 |
妇产科学 | 590篇 |
基础医学 | 3211篇 |
口腔科学 | 673篇 |
临床医学 | 1924篇 |
内科学 | 6760篇 |
皮肤病学 | 581篇 |
神经病学 | 2306篇 |
特种医学 | 653篇 |
外科学 | 4050篇 |
综合类 | 121篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 1914篇 |
眼科学 | 447篇 |
药学 | 1460篇 |
中国医学 | 54篇 |
肿瘤学 | 1678篇 |
出版年
2023年 | 188篇 |
2022年 | 427篇 |
2021年 | 918篇 |
2020年 | 402篇 |
2019年 | 796篇 |
2018年 | 969篇 |
2017年 | 556篇 |
2016年 | 572篇 |
2015年 | 658篇 |
2014年 | 910篇 |
2013年 | 1263篇 |
2012年 | 1992篇 |
2011年 | 1921篇 |
2010年 | 1109篇 |
2009年 | 1034篇 |
2008年 | 1640篇 |
2007年 | 1670篇 |
2006年 | 1587篇 |
2005年 | 1553篇 |
2004年 | 1267篇 |
2003年 | 1213篇 |
2002年 | 1154篇 |
2001年 | 308篇 |
2000年 | 292篇 |
1999年 | 287篇 |
1998年 | 193篇 |
1997年 | 170篇 |
1996年 | 157篇 |
1995年 | 165篇 |
1994年 | 127篇 |
1993年 | 104篇 |
1992年 | 154篇 |
1991年 | 130篇 |
1990年 | 113篇 |
1989年 | 113篇 |
1988年 | 90篇 |
1987年 | 102篇 |
1986年 | 108篇 |
1985年 | 80篇 |
1984年 | 73篇 |
1983年 | 44篇 |
1982年 | 49篇 |
1981年 | 58篇 |
1980年 | 39篇 |
1979年 | 55篇 |
1978年 | 55篇 |
1977年 | 34篇 |
1976年 | 38篇 |
1975年 | 32篇 |
1969年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
John P. Forman Julie Lin Manuel Pascual Mark D. Denton Nina Tolkoff-Rubin 《American journal of transplantation》2004,4(11):1786-1791
The significance of anticardiolipin antibodies (ACAs) prior to renal transplantation is unclear. We studied a cohort of 337 patients who underwent renal transplantation from 1996 to 2001. Follow-up continued until allograft loss, patient death or 31 December 2002. The primary outcome was a composite endpoint of death-censored allograft loss or a 25% reduction in estimated glomerular filtration rate (GFR) from 1-month post-transplant. Secondary outcomes were allograft loss, a 25% reduction in GFR, acute rejection and creatinine at 1 year. IgG and IgM ACA titers were positive (> or =15) in 18.1% of recipients. There were no significant differences at baseline between recipients, except coumadin therapy in those with positive ACA titers (20% vs. 7.4%). Post-transplant, there was no increase in the primary outcome in ACA-positive patients, even after adjustment for anticoagulation with coumadin (HR = 1.42 [0.68, 2.96]). There was no difference in secondary outcomes between those with or without positive titers. Two of five patients with very high titers (>50) who were not anticoagulated had early graft loss. A positive ACA titer prior to kidney transplantation was not associated with inferior renal outcomes after transplantation, although more research is required to address the prognostic significance of very high ACA titers. 相似文献
32.
Andreia Coroas José G G de Oliveira Susana Sampaio Cátia Borges Isabel Tavares Manuel Pestana Maria D V de Almeida 《Journal of renal nutrition》2004,14(3):157-163
OBJECTIVE: Kidney transplantation restores renal filtration, although it does not achieve the function of 2 native kidneys, and with time it may involute back to chronic renal failure. We hypothesized that bioelectrical impedance analysis (BIA) might highlight differences for body compartments among kidney transplants (Tx) with different filtration rates. METHODS: Thirty transplantation patients (19 male, 11 female) were studied at 62.4+/-26.6 months postsurgery and were divided into 3 groups: good creatinine clearance (crCl, mL/min/1.73 m2; >65.0), borderline (35.0相似文献
33.
34.
J Sabán J L Rodríguez-García J Gil J R País S Medina 《The Netherlands journal of medicine》1991,39(5-6):350-352
The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient. 相似文献
35.
Felipe A. Calvo David Ortiz de Urbina Luis Sierrasesúmaga Oscar Abuchaibe Ignacio Azinovic Federico Antillon Manuel Santos Jos Canadell 《Pediatric blood & cancer》1991,19(6):478-485
From September 1984 to December 1989, 38 patients of pediatric age with localized bone sarcomas received intraoperative radiotherapy (IORT) as part of a multidisci plinary treatment program. The age ranged from 6 to 21 years. The tumor histologies were 22 osteosarcomas and 16 Ewing's sarcomas. Thirty-four had initial primary disease (90%) and 4 were treated for local recurrence (10%). IORT was used on 32 untreated patients and in 6 previously treated with external beam radiotherapy (EBR). The IORT field included the surgically exposed tumor bed area. Single radiation doses ranging from 10 to 20 Gy were delivered, using 6–20 MeV electron beams. The median follow-up time for the entire group is 25 months (2–65+ months). The projected 5-year disease-free and overall survival rates are 65% and 69%, respectively. One patient developed a local recurrence in each histological group: one chondroblastic osteosarcoma and one cervical Ewing's sarcoma. Six patients died from metastatic progression: 3 initially recurrent tumors and three primary disease cases. Severe neuropathy and soft tissue necrosis were seen in some patients as IORT related complications. IORT is a feasible technique to be integrated in multidisciplinary programs that may promote local control in pediatric and adolescent patients with bone sarcomas. Peripheral nerves are dose-limiting tissue structures for IORT. 相似文献
36.
37.
M. Medina C. Barata T. Telfer D. J. Baird 《Archives of environmental contamination and toxicology》2002,42(1):17-22
Acute effects of cypermethrin, a pesticide used to treat ectoparasite infestations of salmon, were assessed using the calanoid
copepod Acartia tonsa. A. tonsa has been widely used for hazard assessment of chemicals in the marine environment using acute toxicity tests, but only with
randomly selected adults, assuming a sex ratio of 1:1. The present study assesses the environmental hazard of cypermethrin
by exposing nauplii and adult males and females, separately. Our results showed that the naupliar stages were 28 times more
sensitive to cypermethrin than adults after 96 h of exposure, with LC50s of 0.005 μg L−1 and 0.142 μg L−1, respectively. Significant differences in sensitivity between sexes were only found during the first 24 h of exposure, with
males being approximately twice as sensitive as females. The results of age-related variation in sensitivity are supported
by studies with other species of copepods and toxicants, where the increased capacity of the adults for detoxification, the
allometric differences in weight and size, and the molting process are given as explanations. Variation in sensitivity between
sexes is discussed in terms of faster depuration rates in females through egg production and implications of feeding rate
changes after 24 h of exposure. Our results suggested that standard toxicity test methods using A. tonsa are unsatisfactory because the most sensitive life stage is not included and sex-related differences in tolerance are not
taken into account. We also found that cypermethrin caused significant mortality in Acartia at exposures concentrations from one to three orders of magnitudes lower than the recommended field treatment concentration
for copepodic infestations.
Received: 27 April 2001/Accepted: 1 July 2001 相似文献
38.
J Suárez de Lezo A Medina M Pan E Hernández M Sancho A Bethencourt M Romero F Melián J Segura F Jiménez 《Revista espa?ola de cardiología》1991,44(2):106-114
We study 40 patients, 55 +/- 7 years old with acute myocardial infarction treated early by thrombolytic therapy (20 STK and 20 rt-PA). All patients were angiographically studied in the following conditions: 1) baseline, before initiating therapy. 2) Three hours after treatment. 3) Twenty four hours later. 4) Before discharge. The infarct related artery was patent 24 hours after treatment in 31 patients (78%); five of them were patent before treatment, and we observed an early reperfusion in 20 patients (57%) and late reperfusion in 6 patients (17%). The number of patients with angiographic evidence of intraluminal thrombus decreased progressively through conditions while the grade TIMI of coronary perfusion increased in the absence of reocclusion. Final regional wall motion of infarct related myocardial zones and their degree of recovery were significantly higher in recanalized patients, as compared with non-reperfused patients. Similarly, left ventricular functional recovery was higher in patients with antegrade of collateral flow to the infarct area, as compared with totally occluded patients. 相似文献
39.