全文获取类型
收费全文 | 4017篇 |
免费 | 137篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 246篇 |
妇产科学 | 130篇 |
基础医学 | 260篇 |
口腔科学 | 198篇 |
临床医学 | 352篇 |
内科学 | 752篇 |
皮肤病学 | 49篇 |
神经病学 | 221篇 |
特种医学 | 275篇 |
外科学 | 895篇 |
综合类 | 59篇 |
预防医学 | 121篇 |
眼科学 | 128篇 |
药学 | 153篇 |
中国医学 | 6篇 |
肿瘤学 | 208篇 |
出版年
2023年 | 32篇 |
2022年 | 52篇 |
2021年 | 92篇 |
2020年 | 59篇 |
2019年 | 56篇 |
2018年 | 104篇 |
2017年 | 81篇 |
2016年 | 130篇 |
2015年 | 133篇 |
2014年 | 184篇 |
2013年 | 229篇 |
2012年 | 288篇 |
2011年 | 285篇 |
2010年 | 145篇 |
2009年 | 132篇 |
2008年 | 272篇 |
2007年 | 336篇 |
2006年 | 302篇 |
2005年 | 280篇 |
2004年 | 246篇 |
2003年 | 173篇 |
2002年 | 154篇 |
2001年 | 93篇 |
2000年 | 65篇 |
1999年 | 65篇 |
1998年 | 25篇 |
1997年 | 16篇 |
1996年 | 12篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1985年 | 14篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 4篇 |
1955年 | 2篇 |
排序方式: 共有4181条查询结果,搜索用时 15 毫秒
1.
2.
3.
Alan A Arslan Anne Zeleniuch-Jacquotte Annekatrin Lukanova Yelena Afanasyeva Joseph Katz Mortimer Levitz Giuseppe Del Priore Paolo Toniolo 《Cancer epidemiology, biomarkers & prevention》2006,15(11):2123-2130
Epidemiologic evidence suggests that a full-term pregnancy may affect maternal risk of breast cancer later in life. The objective of this cross-sectional study was to compare circulating levels of maternal hormones affecting breast differentiation (human chorionic gonadotropin and prolactin) and proliferation [alpha-fetoprotein, insulin-like growth factor I (IGF-I), and estradiol] between women at a low to moderate risk (Asians and Hispanics), as compared with women at a high risk for breast cancer (Caucasians and African-Americans). Between May 2002 and December 2004, a total of 586 pregnant women were approached during a routine prenatal visit. Among them, 450 women (206 Caucasian, 126 Asian, 88 Hispanic, and 30 African-American) met the inclusion criteria and signed the informed consent. Only singleton pregnancies were considered. Blood samples were drawn during the second trimester of pregnancy. Laboratory analyses were done using the IMMULITE 2000 immunoassay system. Gestational age standardized mean levels of estradiol, IGF-I, and prolactin were significantly higher in Hispanic women compared with Caucasian women. Mean concentration of IGF-I was significantly higher in African-American women compared with Caucasian and Asian women. No significant differences in pregnancy hormone levels were observed between Caucasian and Asian (predominantly second-generation Chinese) women in this study. Irrespective of ethnicity, women who had their first pregnancy had substantially higher mean levels of alpha-fetoprotein, human chorionic gonadotropin, estradiol, and prolactin compared with women who previously had at least one full-term pregnancy. These data suggest that circulating pregnancy hormone levels may explain some of the ethnic differences in breast cancer risk. 相似文献
4.
Background
The combination therapies recommended by the World Health Organization for treatment of brucellosis are doxycycline plus rifampicin or doxycycline plus streptomycin. Although highly successful results have been obtained with these two regimens, relapse rates as high as 14.4%. The most effective and the least toxic chemotherapy for human brucellosis is still undetermined. The aim of the present study was to investigate the efficacy, adverse effects and cost of ofloxacin plus rifampicin therapy, and doxycycline plus rifampicin therapy and evaluate in the treatment of brucellosis. 相似文献5.
In this prospective study done between 1983 and 1989, of 109 children with acute renal failure in Sivas, Turkey, infectious disease was found in 94. This was related mainly to preventable disease such as acute gastro-enteritis, sepsis and post-streptococcal acute glomerulonephritis. Within this infectious disease group, the highest incidence rate was found in sepsis. 相似文献
6.
Polyester-crystic cast was observed to reach the peritubular capillary plexus following injection in sheep kidneys. Microvascular structures in this region are also reported in this study. Glomeruli were found to vary in size and shape. Diameters of afferent arterioles were larger than those of efferent arterioles. The glomerulus is supplied by more than one afferent arteriole, and in some regions, the blood in afferent arterioles joins collateral circulation via the intercapillary plexus. Morphological properties at the end of the peritubular capillary plexus were found to be remarkably significant. 相似文献
7.
Sabri Acarturk Emrah Arslan Ferit Demirkan Sakir Unal 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(4):409-16; discussion 417-8
Severe middle vault deformity with disturbed nasal form and function is one of the most challenging procedures to correct in a secondary rhinoplasty. Reconstructing the deformity with autologous septal cartilage would be the primary choice of most surgeons, if it were always available. However in certain cases the lack of a sufficient quantity of autologous cartilage has forced surgeons to explore other viable options. This paper discusses our experience with the combined use of spreader and dorsal onlay grafts from various materials in the reconstruction of severe middle vault deformity in 110 patients. In follow up, (between 6 and 42 months; mean 21 months) all patients were noted to have improved in both aesthetics and function with no major complications noted. In summary, this study proposes that any engrafting material can be used safely when the proper surgical principals and technique are employed. 相似文献
8.
Sevcan A Bakkaloglu Necla Buyan Tohru Funahashi Hatice Pasaoglu Atilla H Elhan Enver Hasanoglu Oguz Soylemezoglu 《Peritoneal dialysis international》2005,25(4):357-361
BACKGROUND: Atherosclerotic vascular diseases are the major cause of mortality in patients with end-stage renal disease (ESRD) treated with chronic peritoneal dialysis (CPD), even in children. Adiponectin (ADPN) is a recently discovered adipocyte-derived plasma protein having anti-atherogenic properties. ADPN levels are elevated in ESRD but it has been reported that ESRD patients with low plasma ADPN levels have a high risk of cardiovascular death. OBJECTIVE: To clarify the atherosclerotic risk and especially the significance of ADPN levels in pediatric patients on CPD. DESIGN: Cross-sectional studyin the pediatric peritoneal dialysis unit of a university hospital. PATIENTS: 18 children, aged 12.6 +/- 5.6 years, being treated with CPD and 20 healthy age- and sex-matched control subjects were enrolled in this study. METHODS: Serum ADPN levels and other risk factors, including blood pressure, blood glucose, serum lipid/lipoprotein fractions, apolipoprotein B, C-reactive protein (CRP), lipoprotein(a), and homocysteine levels, were studied in CPD patients and compared to the controls. RESULTS: Serum ADPN levels were three times higher in the CPD group compared to the control subjects, as was previously reported. Apolipoprotein B and CRP levels were also high in the CPD group. No significant difference was found in other atherosclerotic parameters, including lipoprotein(a) and homocysteine levels. Interestingly, we found a negative correlation between log ADPN and creatinine levels among the CPD patients (r = -0.54, p < 0.05). There was no correlation between log ADPN and duration of CPD. Creatinine and low-density lipoprotein levels could account for 54% of the total variation in ADPN levels. CONCLUSION: Among pediatric CPD patients, serum levels of the anti-atherogenic protein, ADPN, were inversely associated with creatinine. ADPN level might be a novel marker to predict prognosis in pediatric CPD patients. 相似文献
9.
A 2-year-old boy with known sickle cell disease presented in acute coma. CT revealed bilateral thalamic infarcts and incomplete sinus thrombosis. Angiography confirmed thrombosis of the straight sinus and vein of Galen. 相似文献
10.
The Human Leukocyte Antigen (HLA) typing of large groups of patients with various autoimmune diseases has demonstrated that some HLA alleles occur at higher frequencies in specific diseases than in the general population. Chronic urticaria has been shown to have an autoimmune basis by a previous study which found an association between chronic urticaria and specific HLA groups. We investigated the HLA subtypes of Turkish chronic urticaria patients. For this purpose 42 Turkish patients with chronic urticaria and 115 healthy controls were typed for HLA-DR and DQ by PCR-SSP (Polymerase Chain Reaction Sequence Specific Primers) low resolution DNA technique. We found an increased frequency of DR4 (42.9%, p=0.01) in chronic urticaria patients in comparison with that in healthy controls. This study supports the hypothesis that HLA alleles may be involved in the pathogenesis of chronic urticaria and that they appear to be directly involved in the initiation of the immune response. 相似文献