全文获取类型
收费全文 | 2284篇 |
免费 | 124篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 107篇 |
妇产科学 | 37篇 |
基础医学 | 339篇 |
口腔科学 | 100篇 |
临床医学 | 122篇 |
内科学 | 550篇 |
皮肤病学 | 8篇 |
神经病学 | 198篇 |
特种医学 | 94篇 |
外科学 | 429篇 |
综合类 | 2篇 |
预防医学 | 131篇 |
眼科学 | 18篇 |
药学 | 151篇 |
中国医学 | 6篇 |
肿瘤学 | 109篇 |
出版年
2023年 | 20篇 |
2022年 | 28篇 |
2021年 | 55篇 |
2020年 | 28篇 |
2019年 | 59篇 |
2018年 | 76篇 |
2017年 | 39篇 |
2016年 | 48篇 |
2015年 | 34篇 |
2014年 | 81篇 |
2013年 | 106篇 |
2012年 | 157篇 |
2011年 | 154篇 |
2010年 | 86篇 |
2009年 | 81篇 |
2008年 | 120篇 |
2007年 | 123篇 |
2006年 | 125篇 |
2005年 | 114篇 |
2004年 | 98篇 |
2003年 | 98篇 |
2002年 | 87篇 |
2001年 | 56篇 |
2000年 | 60篇 |
1999年 | 56篇 |
1998年 | 26篇 |
1997年 | 17篇 |
1996年 | 18篇 |
1995年 | 16篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 39篇 |
1991年 | 35篇 |
1990年 | 28篇 |
1989年 | 25篇 |
1988年 | 22篇 |
1987年 | 19篇 |
1986年 | 28篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有2418条查询结果,搜索用时 15 毫秒
91.
92.
G Colombo G Grandi A Romeo G Giovannini D Pelizzola L Catozzi A Piffanelli 《General and comparative endocrinology》1987,65(2):167-178
Complete testicular maturation was induced in silver eels, kept at 24 degrees in fresh water, by a single injection of 1000 I.U. of heterologous gonadotropin (hCG). Each week, for 4 weeks, some eels were examined for testis structural pattern, plasma sex steroids, and gonad cytosol steroid receptors. The first effect of the hCG was on the tubular organization of the testis, followed by spermatogenesis. Plasma androgens were not detectable in the untreated eels, whereas a peak was detected a week after in those treated with the injection and afterward a decline. Plasma progesterone and estradiol showed a peak 2 weeks after treatment. Untreated eel gonads showed a high content of cytosolic free estradiol receptors which disappeared in the hCG-treated ones, a peak of free progesterone receptors was found 1 week after injection. The results are discussed in relation to the differentiation and maturation of eels testes. 相似文献
93.
Adverse effects of fructose on cardiometabolic risk factors and hepatic lipid metabolism in subjects with abdominal obesity 下载免费PDF全文
94.
Calabrò P Limongelli G Maddaloni V Vizza CD D'Alto M D'Alessandro R Poscia R Argiento P Ziello B Badagliacca R Romeo E Pacileo G Russo MG Fedele F Calabrò R 《Internal and emergency medicine》2012,7(5):425-430
This study analyses the frequency and the potential role of two polymorphisms, the +134del/insA, located in the gene encoding for Endothelin-1 (EDN1), and the His323His in the gene encoding for Endothelin receptor type A (EDNRA) in a cohort of 98 consecutive patients with pulmonary arterial hypertension from two different Cardiology Units (Mid-South of Italy), and in 100 healthy Caucasian subjects randomly recruited from the same area. Cardiac anatomy and function were analysed by non invasive diagnostic imaging techniques (Echocardiography standard m-mode, 2D, colour-Doppler) and by invasive studies (cardiac catheterization). Molecular screening of the region of interest was performed by automated sequencing. At univariate analysis, patients with the His323His TT genotype show a lower cardiac index (2 ± 0.6 vs. 2.3 ± 0.6; p = 0.05) and a higher indexed pulmonary vascular resistance (18.8 ± 9.6 vs. 14.2 ± 6.9; p = 0.01) at cardiac catheterization. A logistic multivariate model shows idiopathic disease (p = 0.01; OR = 3.8; CI = 1.3-11) and indexed pulmonary vascular resistances (p = 0.01; OR = 1.1; CI = 1-1.2) as independent predictors of TT genotype. Our findings may suggest a potential link between specific genotypes in the EDNRA gene and susceptibility for PAH. 相似文献
95.
96.
97.
Gaspare Palaia Alessandra Impellizzeri Gianluca Tenore Federico Caporali Paolo Visca Alessandro Del Vecchio Gabriella Galluccio Antonella Polimeni Umberto Romeo 《Clinical oral investigations》2020,24(8):2645-2652
The aim of this study was to evaluate, ex vivo, the histological effects of 445-nm diode laser (Eltech K-Laser srl, Treviso, Italy), during an oral soft ti 相似文献
98.
Peng S Huang J Sheehy JE Laza RC Visperas RM Zhong X Centeno GS Khush GS Cassman KG 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(27):9971-9975
The impact of projected global warming on crop yields has been evaluated by indirect methods using simulation models. Direct studies on the effects of observed climate change on crop growth and yield could provide more accurate information for assessing the impact of climate change on crop production. We analyzed weather data at the International Rice Research Institute Farm from 1979 to 2003 to examine temperature trends and the relationship between rice yield and temperature by using data from irrigated field experiments conducted at the International Rice Research Institute Farm from 1992 to 2003. Here we report that annual mean maximum and minimum temperatures have increased by 0.35 degrees C and 1.13 degrees C, respectively, for the period 1979-2003 and a close linkage between rice grain yield and mean minimum temperature during the dry cropping season (January to April). Grain yield declined by 10% for each 1 degrees C increase in growing-season minimum temperature in the dry season, whereas the effect of maximum temperature on crop yield was insignificant. This report provides a direct evidence of decreased rice yields from increased nighttime temperature associated with global warming. 相似文献
99.
Maria Luisa Torre Giuseppina T. Russo Marta Ragonese Annalisa Giandalia Ernesto De Menis Giorgio Arnaldi Angela Alibrandi Carmelo Buda Giovanni Romanello Elisabetta L. Romeo Domenico Cucinotta Francesco Trimarchi Salvatore Cannavo 《Pituitary》2014,17(3):257-266
Background
Acromegalic patients have a higher risk of developing colorectal tumours (CRT). The common C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene is a well-documented CRT risk factor in the general population, but its role in acromegaly has never been examined.Purpose
We investigated the influence of MTHFR C677T polymorphism, folate status and other lifestyle, nutritional and disease-specific variables on CRT risk in acromegaly.Methods
Clinical data were collected from 115 acromegalic patients (25 with active disease) who underwent a complete colonoscopy. C677T MTHFR genotype, homocysteine, vitamin B12, insulin growth factor and insulin levels, as well as metabolic variables were evaluated.Results
Colorectal tumours were identified in 51 patients (3 adenocarcinomas). MTHFR C677T distribution was in the Hardy–Weinberg equilibrium and similar in patients with or without CRT. There was a correlation between patients with TT genotype and CRT occurrence (Spearman’s test: P = 0.03), with an Odds Ratio (OR) of 1.32 (95 % CI 0.522–3.362, P NS). A folate–MTHFR genotype interaction on CRT risk was found (P = 0.037): in the lower folate subgroup, TT patients showed a 2.4 higher OR for CRT (95 % CI 0.484–11.891; P NS) than C-allele carriers. Smoking (P = 0.007), increased HbA1c levels (P = 0.021), dyslipidaemia (P = 0.049), acromegaly control (P = 0.057), and folate–MTHFR genotype interaction (P = 0.088) were associated with CRT at multivariate analysis.Conclusions
In this cohort of acromegalic patients, CRT risk is increased in 677TT MTHFR patients with low plasma folate levels. Smoking, high HbA1c levels, dyslipidaemia and disease activity were also associated with increased CRT risk. 相似文献100.
Cristina d’Agostino Pietro Romeo Vito Lavanga Salvatore Pisani Valerio Sansone 《Rheumatology international》2014,34(11):1513-1518
There is no gold standard for treatment of bone marrow edema syndrome of the hip (BMESH). Usually, treatment is conservative, owing to the favorable and self-limiting prognosis. In musculoskeletal disorders, the effectiveness of extracorporeal shock wave therapy (ESWT) has been widely recognized and recent research supports its use in the treatment of the first stages of avascular osteonecrosis of the proximal femur and in other conditions where bone marrow edema is present. On this basis, we performed a prospective study to evaluate the effectiveness of ESWT in normalizing the symptoms and imaging features of BMESH. Twenty consecutive symptomatic patients underwent two treatments of high-energy ESWT and were followed-up at 2, 3 and 6 months, with a final clinical follow-up at mean 15.52 ± 1.91 months. Patients underwent magnetic resonance imaging of the hip and were evaluated according to the Harris hip score. The mean improvement in HHS over the course of the study was of 58.5 ± 14.9 points (p < 0.0001), and the mean edema area reduced from 981.9 ± 453.2 mm2 pre-treatment to 107.8 ± 248.1 mm2 at 6 months. ESWT seems to be a powerful, non-pharmacological tool that produces rapid pain relief and functional improvement and aids the normalization of the vascular and metabolic impairments which characterize BMESH. 相似文献