全文获取类型
收费全文 | 6520篇 |
免费 | 2574篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 186篇 |
儿科学 | 186篇 |
妇产科学 | 197篇 |
基础医学 | 122篇 |
口腔科学 | 40篇 |
临床医学 | 1123篇 |
内科学 | 1894篇 |
皮肤病学 | 425篇 |
神经病学 | 630篇 |
特种医学 | 213篇 |
外科学 | 2149篇 |
综合类 | 20篇 |
预防医学 | 625篇 |
眼科学 | 514篇 |
药学 | 107篇 |
中国医学 | 3篇 |
肿瘤学 | 696篇 |
出版年
2024年 | 56篇 |
2023年 | 676篇 |
2022年 | 75篇 |
2021年 | 268篇 |
2020年 | 377篇 |
2019年 | 150篇 |
2018年 | 645篇 |
2017年 | 715篇 |
2016年 | 615篇 |
2015年 | 564篇 |
2014年 | 762篇 |
2013年 | 671篇 |
2012年 | 297篇 |
2011年 | 258篇 |
2010年 | 462篇 |
2009年 | 621篇 |
2008年 | 254篇 |
2007年 | 118篇 |
2006年 | 174篇 |
2005年 | 107篇 |
2004年 | 60篇 |
2003年 | 53篇 |
2002年 | 61篇 |
2001年 | 102篇 |
2000年 | 51篇 |
1999年 | 73篇 |
1998年 | 83篇 |
1997年 | 96篇 |
1996年 | 66篇 |
1995年 | 62篇 |
1994年 | 44篇 |
1993年 | 32篇 |
1992年 | 62篇 |
1991年 | 50篇 |
1990年 | 35篇 |
1989年 | 35篇 |
1988年 | 43篇 |
1987年 | 19篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 13篇 |
1974年 | 9篇 |
1972年 | 9篇 |
1970年 | 10篇 |
1969年 | 10篇 |
排序方式: 共有9130条查询结果,搜索用时 15 毫秒
31.
32.
33.
Gregory M. Marcus MD Yanfei Yang MD Paul D. Varosy MD Karen Ordovas MD Zian H. Tseng MD Nitish Badhwar MBBS Byron K. Lee MD Randall J. Lee MD Melvin M. Scheinman MD Jeffrey E. Olgin MD 《Heart rhythm》2007,4(2):138-144
BACKGROUND: Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis. OBJECTIVES: The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium. METHODS: Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude. RESULTS: The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05). CONCLUSION: Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls. 相似文献
34.
John F. Fraser MBChB ; Leila Cuttle BSc ; Margit Kempf BmedLSci ; Gael E. Phillips MBBS ; Peter K. O'Rourke PhD ; Kelvin Choo MBBS ; Mark T. Hayes PhD ; Roy M. Kimble MBChB 《Wound repair and regeneration》2005,13(2):189-197
Early to mid-term fetuses heal cutaneous incisional wounds without scars; however, fetal response to burn injury has not been ascertained. We present a fetal model of thermal injury and subsequent analysis of fetal and lamb response to burn injury. A reproducible deep dermal burn injury was created in the fetus by application of water at 66 degrees C for 7 seconds, and at 82 degrees C for 10 seconds to the lamb. Macroscopically, the area of fetal scald was undetectable from day 7 post injury, while all lamb scalds were readily identified and eventually healed with scarring. Using a five-point histopathology scoring system for alteration in tissue morphology, differences were detected between control and scalded skin at all stages in lamb postburn, but no difference was detected in the fetal model after day 7. There were also large differences in content of alpha-smooth muscle actin and transforming growth factor-beta1 between control and scalded lamb and these differences were statistically significant at day 14 (P < 0.01). This novel model of fetal and lamb response to deep dermal injury indicates that the fetus heals a deep burn injury in a scarless fashion. Further elucidation of this specific fetal process of burn injury repair may lead to improved outcome for patients with burn injury. 相似文献
35.
JOSHUA W. SALVIN MD MPH PETER C. LAUSSEN MBBS RAVI R. THIAGARAJAN MBBS MPH 《Paediatric anaesthesia》2008,18(12):1157-1162
Extracorporeal membrane oxygenation (ECMO) is increasingly used to support postcardiotomy cardiorespiratory failure in children with congenital heart disease. We report on survival outcomes and factors associated with survival for postcardiotomy ECMO patients. 相似文献
36.
37.
38.
Rebecca S. Howell-Jones MSc ; Patricia E. Price PhD ; Anthony J. Howard MBBS MSc FRCPath ; David W. Thomas FDRCS MScD PhD 《Wound repair and regeneration》2006,14(4):387-393
The aim of this study was to describe and quantify systemic antibiotic prescribing for patients with chronic skin wounds presenting at the primary care, nonspecialist setting. Data for 1 year were extracted from a general practice morbidity database comprising approximately 185,000 patients attending family medical practitioners in Wales. Patients with chronic wounds (PCW) were identified using Read Codes and compared with nonwound patients who were randomly selected after matching for age-band, sex, and general practice. PCW received a significantly greater number of antibiotic courses than nonwound patients (p<0.001). This increased level of prescribing was evident for flucloxacillin, co-amoxiclav, cefaclor, cefalexin, erythromycin, trimethoprim, metronidazole, and ciprofloxacin (p<0.01 for all). While PCW also had a significantly higher prevalence of diabetes (16.5% compared with 6.6%, p<0.001), and attended at general practice significantly more frequently than nonwound patients (median (interquartile range) of 25 (17-40) visits per year compared with 12 (4-20), p<0.001), importantly, exclusion of diabetic patients and analysis of the proportion of visits on which patients received antibiotics did not affect the significance of the difference in antibiotic consumption. These data show a strong association between occurrence of chronic wounds and prescribing of antibiotics in primary health care, and wide variation in the type and duration of antibiotic therapy for chronic wounds. Further work is now indicated to rationalize this prescribing and determine the role that this exposure to antibiotics plays in the prevalence of antibiotic resistance in this at-risk elderly population. 相似文献
39.
The rates of glycerol release in adipocytes isolated from nine identified adipose depots of sedentary or exercised guinea-pigs were measured in the presence of adenosine deaminase and 10(-9) to 10(-5) M noradrenaline and/or 1-1000 muunit/ml of bovine insulin. Twenty minutes of exercise increased the basal noradrenaline-stimulated rates of lipolysis in all depots, but these effects, and their interactions with in vitro application of the neurotransmitter differed between depots, showing that the long-lasting effects of exercise and the response to acute application of NA involve different mechanisms that may occur separately or together in different adipose depots. In general, large depots had the highest resting rates of lipolysis and the lowest responses to both noradrenaline and insulin, and lipolysis was only slightly different from the basal rate in adipocytes incubated with mixtures of the two agents. The two small intermuscular depots had the lowest unstimulated rates of lipolysis, but the fastest change and greatest maximum response to both agents. Noradrenaline-stimulated lipolysis was most effectively inhibited by small quantities of insulin in these depots. Different combinations of these properties were demonstrated in two smaller superficial depots, the mesenteric and omental depot, and in the cardiac depots. The data demonstrate the physiological inhomogeneity of both 'subcutaneous' and 'intra-abdominal' depots, and are consistent with the hypothesis that intermuscular adipose tissue interacts locally with adjacent muscle. Noradrenaline-stimulated lipolysis was more effectively inhibited by 100 muunit/ml insulin in adipocytes from the mesenteric and omental depot in those from any other site. A possible role for this property in the enlargement of this depot in hyperinsulinaemia in humans is proposed. 相似文献
40.