全文获取类型
收费全文 | 1078030篇 |
免费 | 70991篇 |
国内免费 | 4495篇 |
专业分类
耳鼻咽喉 | 14882篇 |
儿科学 | 33318篇 |
妇产科学 | 30510篇 |
基础医学 | 151287篇 |
口腔科学 | 29813篇 |
临床医学 | 87354篇 |
内科学 | 220101篇 |
皮肤病学 | 23757篇 |
神经病学 | 85085篇 |
特种医学 | 41070篇 |
外国民族医学 | 354篇 |
外科学 | 161428篇 |
综合类 | 23990篇 |
现状与发展 | 4篇 |
一般理论 | 277篇 |
预防医学 | 84780篇 |
眼科学 | 24754篇 |
药学 | 78872篇 |
23篇 | |
中国医学 | 4029篇 |
肿瘤学 | 57828篇 |
出版年
2021年 | 9799篇 |
2019年 | 10252篇 |
2018年 | 14822篇 |
2017年 | 10959篇 |
2016年 | 11458篇 |
2015年 | 13252篇 |
2014年 | 17703篇 |
2013年 | 26314篇 |
2012年 | 37242篇 |
2011年 | 39470篇 |
2010年 | 23112篇 |
2009年 | 20639篇 |
2008年 | 35668篇 |
2007年 | 37780篇 |
2006年 | 37677篇 |
2005年 | 36706篇 |
2004年 | 34502篇 |
2003年 | 33112篇 |
2002年 | 32363篇 |
2001年 | 45923篇 |
2000年 | 47509篇 |
1999年 | 40137篇 |
1998年 | 11063篇 |
1997年 | 9973篇 |
1996年 | 9796篇 |
1995年 | 9088篇 |
1994年 | 8660篇 |
1992年 | 30245篇 |
1991年 | 28846篇 |
1990年 | 28224篇 |
1989年 | 26906篇 |
1988年 | 25080篇 |
1987年 | 24566篇 |
1986年 | 23644篇 |
1985年 | 22469篇 |
1984年 | 16759篇 |
1983年 | 14290篇 |
1982年 | 8508篇 |
1979年 | 15666篇 |
1978年 | 10931篇 |
1977年 | 9323篇 |
1976年 | 8825篇 |
1975年 | 9771篇 |
1974年 | 11711篇 |
1973年 | 11256篇 |
1972年 | 10686篇 |
1971年 | 9877篇 |
1970年 | 9495篇 |
1969年 | 9015篇 |
1968年 | 8664篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
D. J. Lederer S. M. Arcasoy R. G. Barr J. S. Wilt E. Bagiella F. D'Ovidio J. R. Sonett S. M. Kawut 《American journal of transplantation》2006,6(10):2436-2442
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant. 相似文献
52.
D Monnier† C Vidal‡ L Martin§ A Danzon¶ F Pelletier† E Puzenat† MP Algros†† D Blanc† R Laurent† PH Humbert† F Aubin† 《Journal of the European Academy of Dermatology and Venereology》2006,20(10):1237-1242
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating. 相似文献
53.
Neetu Radhakrishnan M.D. Chong. H. Park M.D. Barry M. Kaplan M.D. F.A.C.C. Rajiv Jauhar M.D. F.A.C.C. 《The International journal of angiology》2006,15(1):37-42
A 65-year-old man developed acute limb ischemia, severe abdominal wall and lower limb livedo reticularis following a coronary
angiogram. The differential diagnoses of acute limb ischemia and multiple cholesterol emboli syndrome (MCES) are discussed.
This work was performed at Long Island Jewish Medical Center, 270-05, 76th Avenue, New Hyde Park, NY 11040. 相似文献
54.
Lipid peroxidation, occupational stress and aging in workers of a prehospital emergency service. 总被引:2,自引:0,他引:2
Angela Casado Nieves De Lucas Encarnación López-Fernández Alberto Sánchez José-Antonio Jimenez 《European journal of emergency medicine》2006,13(3):165-171
BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress. 相似文献
55.
Roger F Uren 《Journal of nuclear medicine》2006,47(2):191-195
56.
57.
58.
59.
S F Wong A Lee-Tannock D Amaraddio F Y Chan H D McIntyre 《Ultrasound in obstetrics & gynecology》2006,28(7):934-938
OBJECTIVE: To assess the effect of glucose control on the rate of growth of fetuses in women with pregestational diabetes mellitus (Types 1 and 2). METHODS: All pregestational diabetic women booked at Mater Mothers' Hospital, Brisbane, Australia, between 1 January 1994 and 31 December 2002, were included. Pregnancies with congenital fetal anomalies, multiple pregnancies, and pregnancies terminated prior to 20 weeks' gestation were excluded. Dating scans were performed before 14 weeks' gestation and serial scans were performed at 18, 24, 28, 32 and 36 weeks. Fetal parameters, including biparietal diameter, femur length and abdominal circumference, were recorded. The daily growth rates for biparietal diameter, femur length, and fetal abdominal area were calculated and compared with those in a low-risk (non-diabetic) population. The growth rates in fetuses of women with satisfactory diabetic control (HbA1c < 6.5%) and unsatisfactory control (HbA1c > or = 6.5%) in the three trimesters were compared. RESULTS: A total of 174 diabetic pregnancies were included and a total of 997 ultrasound scans were performed. The growth rates for fetuses of mothers with diabetes mellitus were significantly higher than for those in the low-risk population. The z-scores for biparietal diameter, femur length, and fetal abdominal area were 0.18, 0.59 and 1.44, respectively. Fetuses of diabetic mothers with high HbA1c in the first trimester had significantly greater fetal abdominal area growth rate than those with normal HbA1c (fetal abdominal area z-score of 1.7 vs. 0.75, P = 0.009). Although the fetal abdominal area z-scores in fetuses of diabetic mothers with high HbA1c in the second or third trimesters were also higher than those with normal HbA1c levels, the differences did not reach statistical significance. Maternal obesity did not influence the fetal growth rate. CONCLUSION: The rate of growth of fetuses of diabetic mothers differs from that of the normal population. Growth acceleration persists until the late third trimester. Moreover, periconceptional glucose control appears to have a significant effect on accelerated growth of the fetal abdominal area. 相似文献
60.