全文获取类型
收费全文 | 4631篇 |
免费 | 220篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 91篇 |
妇产科学 | 65篇 |
基础医学 | 660篇 |
口腔科学 | 129篇 |
临床医学 | 378篇 |
内科学 | 1156篇 |
皮肤病学 | 109篇 |
神经病学 | 558篇 |
特种医学 | 110篇 |
外科学 | 595篇 |
综合类 | 24篇 |
一般理论 | 2篇 |
预防医学 | 342篇 |
眼科学 | 34篇 |
药学 | 280篇 |
中国医学 | 3篇 |
肿瘤学 | 281篇 |
出版年
2023年 | 38篇 |
2022年 | 50篇 |
2021年 | 101篇 |
2020年 | 63篇 |
2019年 | 73篇 |
2018年 | 103篇 |
2017年 | 77篇 |
2016年 | 100篇 |
2015年 | 124篇 |
2014年 | 146篇 |
2013年 | 198篇 |
2012年 | 314篇 |
2011年 | 329篇 |
2010年 | 154篇 |
2009年 | 157篇 |
2008年 | 242篇 |
2007年 | 262篇 |
2006年 | 246篇 |
2005年 | 259篇 |
2004年 | 221篇 |
2003年 | 207篇 |
2002年 | 214篇 |
2001年 | 40篇 |
2000年 | 28篇 |
1999年 | 47篇 |
1998年 | 58篇 |
1997年 | 54篇 |
1996年 | 49篇 |
1995年 | 34篇 |
1994年 | 50篇 |
1993年 | 37篇 |
1992年 | 53篇 |
1991年 | 50篇 |
1990年 | 60篇 |
1989年 | 40篇 |
1988年 | 38篇 |
1987年 | 37篇 |
1986年 | 46篇 |
1985年 | 44篇 |
1984年 | 25篇 |
1983年 | 26篇 |
1982年 | 40篇 |
1981年 | 22篇 |
1980年 | 23篇 |
1979年 | 21篇 |
1978年 | 33篇 |
1977年 | 19篇 |
1976年 | 24篇 |
1975年 | 20篇 |
1974年 | 19篇 |
排序方式: 共有4857条查询结果,搜索用时 15 毫秒
51.
Buntzen S Rasmussen OO Ryhammer AM Sørensen M Laurberg S Christiansen J 《Diseases of the colon and rectum》2004,47(8):1409-1411
Fecal incontinence is a common condition that causes major impairment of social life. Sacral nerve stimulation is a promising treatment in idiopathic fecal incontinence when conventional treatments have failed. However, new indications for sacral nerve stimulation are emerging. The present case shows that sacral nerve stimulation for treatment of fecal incontinence may be justified in other diseases in which fecal incontinence is a major problem. 相似文献
52.
Storage time of platelet concentrates and risk of a positive blood culture: a nationwide cohort study 下载免费PDF全文
53.
László B Tankó Lusine Movsesyan Ulrik Mouritzen Claus Christiansen Ole L Svendsen 《Metabolism: clinical and experimental》2002,51(1):69-74
Studies indicate that deficient skeletal muscle mass or sarcopenia is a major cause of disability and morbidity among the elderly. In part, due to the lack of generally applicable normal values, there is still insufficient epidemiologic data available on the frequency and severity of sarcopenia in health and under various disease-related conditions. The objectives of the present study were to (1) characterize the age- and menopause-related variations in appendicular lean tissue mass (LTM(A)), (2) provide young-normal means and estimate the age-specific prevalence of sarcopenia among healthy women. A total of 754 healthy women were included in the study of cross-sectional design. LTM(A) was estimated by dual-energy x-ray absorptiometry (DEXA). Physical characteristics and menopausal status were also registered. LTM(A) as well as height showed significant negative correlation with age with Pearson's r values of -0.43 and -0.06, respectively (P <.05). Trend of finding lower mean values with advancing age remained even when LTM(A) was adjusted for height(2) (ht(2)). Menopause did not seem to have any influence on LTM(A). Young-normal means were obtained from 216 premenopausal women aged 18 to 39 years. Prevalence rates of sarcopenia in healthy women were determined with reference to a cut-off line corresponding to LTM(A) or LTM(A)/ht(2) less than young-normal mean 2 SD and were found to be 40.2% and 12.3%, respectively, among the healthy elderly (>70 years of age). Results of the present study provide further evidence that sarcopenia exists even among otherwise healthy women with increasing age-specific prevalence. Further studies are needed (1) to estimate the prevalence of sarcopenia under various health and disease-related conditions with reference to the hereby given cut-off values and (2) to find therapeutic strategies with beneficial effects in conserving skeletal muscle mass. 相似文献
54.
55.
Pulmonary function and bronchial reactivity in asthmatics during low-level formaldehyde exposure 总被引:1,自引:0,他引:1
This study evaluated whether formaldehyde, at concentrations similar to those found in the indoor environment, could produce adverse effects on the lower airway of 15 asthmatic persons with documented bronchial hyperresponsiveness who were exposed for 90 min in a climate chamber to clean air containing formaldehyde vapor at levels of 0.85 mg/m3, 0.12 mg/m3, and 0.008 mg/m3. No significant changes in forced expiratory volume in 1 sec (FEV1), airway resistance (Raw), specific airway resistance (SRaw), and flow-volume curves could be detected during formaldehyde exposure. Furthermore, histamine challenge tests performed immediately after formaldehyde exposure showed no evidence of changes in bronchial reactivity. No late reactions were registered during the first 14-16 hr after exposure. The results suggest that residential levels of formaldehyde are of minor importance in the emergence of pulmonary symptoms. Discrepancies between the present study and previous data may be due to differences in environmental conditions. 相似文献
56.
BACKGROUND: Congestive heart failure (CHF) has previously been shown to be associated with insulin resistance and hyperinsulinemia. A beneficial effect of the non-selective beta-blocker carvedilol has been demonstrated in patients with CHF. However, whether the drug affects the insulin sensitivity (S(i)) is unknown. AIMS: To investigate whether treatment with carvedilol alters the S(i) in patients with CHF during a prospective, double-blinded, placebo-controlled study. METHODS AND RESULTS: The patients were randomized to receive either carvedilol (n=29) or matched placebo (n=17). Insulin and glucose responses were measured during a 0.3 g/kg intravenous glucose tolerance test, and S(i) was calculated according to Bergman's Minimal Model. Baseline S(i) values correlated significantly with body mass index (r=-0.42, P=0.002), plasma urate (r=-0.42, P=0.002), plasma HDL-cholesterol (r=0.39, P=0.003), maximal oxygen uptake (r=0.35, P=0.009), plasma triglycerides (r=-0.34, P=0.01) and weight (r=-0.29, P=0.03). During the study the insulin sensitivity was unchanged in the carvedilol group compared with placebo (2.63+/-1.45 to 2.38+/-1.64 vs. 2.81+/-2.36 to 2.48+/-1.84x10(-4) min(-1)/mUl(-1), P=0.83). CONCLUSION: Additional treatment with carvedilol is neutral with regard to influence the insulin sensitivity in patients with mild to moderate CHF. 相似文献
57.
58.
Grarup N Andreasen CH Andersen MK Albrechtsen A Sandbaek A Lauritzen T Borch-Johnsen K Jørgensen T Schmitz O Hansen T Pedersen O 《The Journal of clinical endocrinology and metabolism》2008,93(6):2294-2299
CONTEXT: Hepatic lipase plays a pivotal role in the metabolism of high-density lipoprotein (HDL) and low-density lipoprotein by involvement in reverse cholesterol transport and the formation of atherogenic small dense low-density lipoprotein. OBJECTIVES: The objective was to investigate the impact of variants in LIPC on metabolic traits and type 2 diabetes in a large sample of Danes. Because behavioral factors influence hepatic lipase activity, we furthermore examined possible gene-environment interactions in the population-based Inter99 study. DESIGN: The LIPC -250G>A (rs2070895) variant was genotyped in the Inter99 study (n = 6070), the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care Denmark screening cohort of individuals with risk factors for undiagnosed type 2 diabetes (n = 8662), and in additional type 2 diabetic patients (n = 1,064) and glucose-tolerant control subjects (n = 360). RESULTS: In the Inter99 study, the A allele of rs2070895 associated with a 0.057 mmol/liter [95% confidence interval (CI) 0.039-0.075] increase in fasting serum HDL-cholesterol (HDL-c) (P = 8 x 10(-10)) supported by association in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care study [0.038 mmol/liter per allele (95% CI 0.024-0.053); P = 2 x 10(-7)). The allelic effect on HDL-c was modulated by interaction with self-reported physical activity (P(interaction) = 0.002) because vigorous physically active homozygous A-allele carriers had a 0.30 mmol/liter (95% CI 0.22-0.37) increase in HDL-c compared with homozygous G-allele carriers. CONCLUSIONS: We validate the association of LIPC promoter variation with fasting serum HDL-c and present data supporting an interaction with physical activity implying an increased effect on HDL-c in vigorous physically active subjects carrying the -250 A allele. This interaction may have potential implications for public health and disease prevention. 相似文献
59.
Juan Manuel Vlker Federico Gabriel Arguissain Ole Kseler Andersen Jos Biurrun Manresa 《Human brain mapping》2021,42(8):2461
Pain arises from the integration of sensory and cognitive processes in the brain, resulting in specific patterns of neural oscillations that can be characterized by measuring electrical brain activity. Current source density (CSD) estimation from low‐resolution brain electromagnetic tomography (LORETA) and its standardized (sLORETA) and exact (eLORETA) variants, is a common approach to identify the spatiotemporal dynamics of the brain sources in physiological and pathological pain‐related conditions. However, there is no consensus on the magnitude and variability of clinically or experimentally relevant effects for CSD estimations. Here, we systematically examined reports of sample size calculations and effect size estimations in all studies that included the keywords pain, and LORETA, sLORETA, or eLORETA in Scopus and PubMed. We also assessed the reliability of LORETA CSD estimations during non‐painful and painful conditions to estimate hypothetical sample sizes for future experiments using CSD estimations. We found that none of the studies included in the systematic review reported sample size calculations, and less than 20% reported measures of central tendency and dispersion, which are necessary to estimate effect sizes. Based on these data and our experimental results, we determined that sample sizes commonly used in pain studies using CSD estimations are suitable to detect medium and large effect sizes in crossover designs and only large effects in parallel designs. These results provide a comprehensive summary of the effect sizes observed using LORETA in pain research, and this information can be used by clinicians and researchers to improve settings and designs of future pain studies. 相似文献