全文获取类型
收费全文 | 2505篇 |
免费 | 116篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 52篇 |
妇产科学 | 92篇 |
基础医学 | 349篇 |
口腔科学 | 36篇 |
临床医学 | 169篇 |
内科学 | 414篇 |
皮肤病学 | 28篇 |
神经病学 | 334篇 |
特种医学 | 52篇 |
外科学 | 336篇 |
综合类 | 5篇 |
预防医学 | 344篇 |
眼科学 | 27篇 |
药学 | 225篇 |
中国医学 | 2篇 |
肿瘤学 | 164篇 |
出版年
2022年 | 12篇 |
2021年 | 48篇 |
2020年 | 14篇 |
2019年 | 29篇 |
2018年 | 48篇 |
2017年 | 41篇 |
2016年 | 48篇 |
2015年 | 51篇 |
2014年 | 72篇 |
2013年 | 80篇 |
2012年 | 161篇 |
2011年 | 167篇 |
2010年 | 89篇 |
2009年 | 73篇 |
2008年 | 136篇 |
2007年 | 165篇 |
2006年 | 153篇 |
2005年 | 170篇 |
2004年 | 155篇 |
2003年 | 140篇 |
2002年 | 139篇 |
2001年 | 36篇 |
2000年 | 36篇 |
1999年 | 27篇 |
1998年 | 25篇 |
1997年 | 21篇 |
1996年 | 11篇 |
1992年 | 24篇 |
1991年 | 25篇 |
1990年 | 20篇 |
1989年 | 14篇 |
1988年 | 20篇 |
1987年 | 23篇 |
1986年 | 19篇 |
1985年 | 24篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 11篇 |
1979年 | 24篇 |
1978年 | 17篇 |
1977年 | 9篇 |
1976年 | 15篇 |
1975年 | 22篇 |
1974年 | 18篇 |
1973年 | 20篇 |
1972年 | 11篇 |
1969年 | 10篇 |
1968年 | 11篇 |
1932年 | 9篇 |
1931年 | 12篇 |
排序方式: 共有2637条查询结果,搜索用时 15 毫秒
41.
Three‐dimensional speckle tracking echocardiography–derived left atrial deformation analysis in acromegaly (Results from the MAGYAR‐Path Study)
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
42.
The effects of androgens and the androgen antagonist, flutamide, on the density of dendritic spine synapses in the CA1 subfield of the hippocampus were studied in gonadectomized male and female rats. Treatment of orchidectomized male rats with dehydroepiandrosterone (DHEA; 2 d, 1 mg/d sc) increased the density of CA1 spine synapses observed 2 d later, by 106%, without significantly affecting ventral prostate weight. The hippocampal response to DHEA was unaffected by blockade of intracerebral estrogen biosynthesis using the aromatase inhibitor, letrozole. By contrast, flutamide alone (2 d; 5 mg/d, sc) increased CA1 spine synapse density by 66%, whereas in combination the effects of flutamide and DHEA were additive rather than inhibitory. Additive effects on CA1 synapse density were also observed in males using combinations of flutamide with 5alpha-dihydrotestosterone (2 d, 500 microg/d, sc). At the same doses, flutamide had no effect on prostate weight and completely blocked the effects on the prostate of treatment with 5alpha-dihydrotestosterone. Treatment of ovariectomized females with DHEA increased CA1 spine synapse density to a level similar to that observed in the male. As in males, flutamide in females increased CA1 spine synapse formation and further augmented the response to DHEA. These results demonstrate that flutamide and DHEA have positive effects on hippocampal CA1 spine synapse density in both sexes. They also suggest that conventional measures of androgen agonist or antagonist activity, exemplified by ventral prostate growth, may not be indicative of effects on hippocampal CA1 synaptogenesis. 相似文献
43.
Impact of single nucleotide polymorphisms of cytarabine metabolic genes on drug toxicity in childhood acute lymphoblastic leukemia
下载免费PDF全文
![点击此处可从《Pediatric blood & cancer》网站下载免费的PDF全文](/ch/ext_images/free.gif)
44.
Melissa Soohoo Elani Streja Yoshitsugu Obi Connie M. Rhee Daniel L. Gillen Keiichi Sumida Danh V. Nguyen Csaba P. Kovesdy Kamyar Kalantar-Zadeh 《Mayo Clinic proceedings. Mayo Clinic》2018,93(8):1074-1085
Objective
To determine whether kidney function level and its rate of decline in the immediate predialysis period among veterans transitioning to end-stage renal disease (ESRD) predict postdialysis mortality and hospitalization.Patients and Methods
In 19,985 veterans transitioning to ESRD during the period October 1, 2007, to March 30, 2014, we examined kidney function and its slope over the final year of the pre-ESRD(prelude) period. Two categories of low vs high estimated glomerular filtration rate (eGFR, dichotomized at 10 mL/min/1.73 m2) and slow vs fast slope (dichotomized at ?10 mL/min/1.73 m2/y) were combined into 4 groups. Their associations with 12-month post-ESRD all-cause and cardiovascular (CV) mortality and hospitalization rates were examined in adjusted models accounting for clinical characteristics and laboratory measurements at transition.Results
Patients, 66±11 years old, and 34% blacks, had a median (interquartile range) eGFR at transition and slope of 9.7 (7.1-13.3) mL/min/1.73 m2 and ?10.5 (?18.8 to ?5.9) mL/min/1.73 m2/y, respectively. Patients with a low eGFR and slow slope had the lowest 12-month all-cause and CV mortality risks and hospitalization rate. Conversely, patients with high eGFR and fast slope had the highest risk of all-cause and CV mortality and hospitalization rate compared with patients with a low eGFR and slow slope. This relationship persisted in sensitivity analyses, including propensity scoring.Conclusion
A kidney profile of a low eGFR and slow slope in the prelude period is associated with favorable early dialysis outcomes in veteran patients. Trials to examine a more conservative approach to dialysis are warranted. 相似文献45.
46.
Zsóka Weiszhár András Bikov Gabriella Gálffy Lilla Tamási Ildikó Ungvári Csaba Szalai György Losonczy Ildikó Horváth 《Journal of clinical immunology》2013,33(2):496-505
Background
The alternative pathway of the complement system is known to play a role in the generation of asthmatic airway inflammation, but its regulatory complement protein, factor H has not been investigated in this disease.Purpose
Our aim was to determine the local bronchial complement factor H (CFH) levels in asthma, and to investigate its relationship with complement activation, systemic CFH concentrations and clinical characteristics of patients.Methods
Induced sputum and plasma were collected from 21 healthy and 26 asthmatic subjects, and complement factor H and SC5b-9 concentrations were assessed by ELISA. Total protein concentrations were determined by biuret-reaction based microassay system from induced sputa.Results
CFH was detectable in 81 % of healthy and 100 % of asthmatic subjects, while SC5b-9 exceeded the detection limit in 62 % of healthy subjects and 85 % of asthmatic patients. Sputum CFH concentrations and CFH/protein ratios were increased in samples from asthmatic patients, and correlated with loss of lung function, asthma control, severity and medication intensity, but not with plasma CFH concentrations. Sputum CFH/protein ratios were in positive correlation also with sputum eosinophilic cell counts in asthma. SC5b-9 concentrations were not higher in the asthmatic sputa, although they correlated with sputum CFH concentrations.Conclusions
CFH level is elevated on asthmatic airway surface, and may be associated with uncontrolled inflammation in asthma. 相似文献47.
48.
49.
Szalay F Folhoffer A Horváth A Csak T Speer G Nagy Z Lakatos P Horváth C Habior A Tornai I Lakatos PL 《European journal of gastroenterology & hepatology》2005,17(9):923-928
BACKGROUND/AIM: The pathophysiology of osteoporosis in chronic liver diseases is unknown. Recent data suggest that serum leptin is associated with bone mineral density (BMD). In animal studies leptin was found to be a potent inhibitor of bone formation. We investigated the relationship between serum leptin levels, soluble leptin receptor (sOB-R), free leptin index (FLI) and BMD in patients with primary biliary cirrhosis (PBC). PATIENTS AND METHODS: Ninety-four female patients with PBC were included in this study; 122 healthy women served as controls. Serum leptin levels were measured by radioimmunoassay, sOB-R by enzyme-linked immunosorbent assay. BMD was measured by dual energy X-ray absorptiometry in the lumbar spine and femoral neck. RESULTS: Serum leptin was significantly lower in patients with PBC compared with healthy controls. No difference was found between the body mass index (BMI) of patients and controls. There was a strong positive correlation between leptin and BMI. In PBC no association was found between leptin, sOB-R and liver function tests, histological stages or the presence of osteoporosis. Osteoporosis was present in 38 patients. A positive correlation was found between serum leptin and femoral neck z-score even after adjustment for BMI, whereas serum sOB-R correlated inversely with the serum leptin level. There was no difference in FLI between the subgroups of PBC patients according to the stages of the disease. CONCLUSIONS: We found a lower serum leptin level and a higher sOB-R in patients with PBC, which could not be explained by the difference in BMI. As leptin was associated with BMD, it may be hypothesized that leptin is involved in the complex regulation of bone metabolism in PBC. 相似文献
50.
Hegyi P Rakonczay-Jr Z Sari R Czako L Farkas N Gog C Nemeth J Lonovics J Takacs T 《World journal of gastroenterology : WJG》2004,10(15):2275-2277
AIM: In previous experiments we have demonstrated that by administering low doses of cholecystokinin-octapeptide (CCK-8), the process of regeneration following L-arginine (Arg)-induced pancreatitis is accelerated. In rats that were also diabetic (induced by streptozotocin, STZ), pancreatic regeneration was not observed. The aim of this study was to deduce whether the administration of exogenous insulin could in fact restore the hypertrophic effect of CCK-8 in diabetic-pancreatitic rats.METHODS: Male Wistar rats were used for the experiments.Diabetes mellitus was induced by administering 60 mg/kg body mass of STZ intraperitoneally (i.p.), then, on d 8, pancreatitis was induced by 200 mg/100 g body mass Argi.p. twice at an interval of 1 h. The animals were injected subcutaneously twice daily (at 7 a.m. and 7 p.m.) with 1 μglkg of CCK-8 and/or 2 IU mixed insulin (300 g/L shortaction and 700 g/L intermediate-action insulin) for 14 d after pancreatitis induction. Following this the animals were killed and the serum amylase, glucose and insulin levels as well as the plasma glucagon levels, the pancreatic mass/body mass ratio (pm/bm), the pancreatic contents of DNA, protein, amylase, lipase and trypsinogen were measured. Pancreatic tissue samples were examined by light microscopy on paraffin-embedded sections.RESULTS: In the diabetic-pancreatitic rats treatment with insulin and CCK-8 significantly elevated pw/bm and the pancreatic contents of protein, amylase and lipase vs the rats receiving only CCK-8 treatment. CCK-8 administered in combination with insulin also elevated the number of acinar cells with mitotic activities, whereas CCK-8 alone had no effect on laboratory parameters or the mitotic activities in diabetic-pancreatitic rats.CONCLUSION: Despite the hypertrophic effect of CCK-8 being absent following acute pancreatitis in diabetic-rats,the simultaneous administration of exogenous insulin restored this effect. Our results clearly demonstrate that insulin is necessary for the hypertrophic effect of low-doses of CCK-8 following acute pancreatitis. 相似文献