全文获取类型
收费全文 | 621783篇 |
免费 | 38741篇 |
国内免费 | 746篇 |
专业分类
耳鼻咽喉 | 8582篇 |
儿科学 | 21705篇 |
妇产科学 | 17141篇 |
基础医学 | 99665篇 |
口腔科学 | 17137篇 |
临床医学 | 52064篇 |
内科学 | 114043篇 |
皮肤病学 | 15316篇 |
神经病学 | 44544篇 |
特种医学 | 23235篇 |
外国民族医学 | 95篇 |
外科学 | 94879篇 |
综合类 | 9964篇 |
一般理论 | 139篇 |
预防医学 | 44284篇 |
眼科学 | 15337篇 |
药学 | 47944篇 |
中国医学 | 1292篇 |
肿瘤学 | 33904篇 |
出版年
2018年 | 5752篇 |
2016年 | 5099篇 |
2015年 | 5669篇 |
2014年 | 7551篇 |
2013年 | 11734篇 |
2012年 | 15729篇 |
2011年 | 17211篇 |
2010年 | 10142篇 |
2009年 | 9568篇 |
2008年 | 16668篇 |
2007年 | 17928篇 |
2006年 | 18311篇 |
2005年 | 17842篇 |
2004年 | 17472篇 |
2003年 | 16686篇 |
2002年 | 16536篇 |
2001年 | 30395篇 |
2000年 | 31388篇 |
1999年 | 25887篇 |
1998年 | 6943篇 |
1997年 | 6167篇 |
1996年 | 6254篇 |
1995年 | 5734篇 |
1994年 | 5327篇 |
1993年 | 5168篇 |
1992年 | 19172篇 |
1991年 | 19645篇 |
1990年 | 19723篇 |
1989年 | 18918篇 |
1988年 | 17350篇 |
1987年 | 17104篇 |
1986年 | 16195篇 |
1985年 | 15434篇 |
1984年 | 11431篇 |
1983年 | 9734篇 |
1982年 | 5420篇 |
1981年 | 5084篇 |
1979年 | 11124篇 |
1978年 | 8111篇 |
1977年 | 6817篇 |
1976年 | 6485篇 |
1975年 | 7507篇 |
1974年 | 8766篇 |
1973年 | 8245篇 |
1972年 | 7942篇 |
1971年 | 7611篇 |
1970年 | 7010篇 |
1969年 | 6636篇 |
1968年 | 6283篇 |
1967年 | 5630篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Abstract Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised
form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region.
A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After
repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the
elderly, as early diagnosis leads to effective treatment and prevention of complications. 相似文献
42.
J I?igo A Arce E Rodríguez D García de Viedma E Palenque M J Ruiz Serrano L Cabello F Chaves 《The international journal of tuberculosis and lung disease》2006,10(5):550-553
SETTING: Tuberculosis (TB) cases reported from nine districts of Madrid, where the percentage of immigrant population varied from 1.9% in 1996 to 12.2% in 2003. OBJECTIVE: To describe the trends in TB incidence from 1994 to 2003. DESIGN: Observational study. RESULTS: Between 1994-1995 and 2002-2003, the TB rate decreased from 48.5 (95% CI 45.8-51.1) to 23.3 per 100000 population (95% CI 21.5-25.1) (P < 0.001). The percentage of TB cases co-infected with HIV decreased from 55.9% in 1994 to 14.3% in 2003 (P < 0.001), whereas TB cases in foreigners increased from 2.6% in 1994 to 33.7% in 2003 (P < 0.001). CONCLUSION: Although the TB rates showed a marked decrease in the study period, the increasing impact of immigration contributed to slowing down the trend. 相似文献
43.
Hale Sayan V Haktan Ozacmak Aysel Guven R Gulhan Aktas I Diler Ozacmak 《Journal of investigative surgery》2006,19(3):163-173
Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, malondialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area. 相似文献
44.
N. N. Polygalova A. G. Mikhailovskii E. S. Limanskii B. Ya. Syropyatov M. I. Vakhrin 《Pharmaceutical Chemistry Journal》2006,40(3):132-134
A series of 1-alkyl-3,4-dihydroisoquinolines and the related 4-alkyl-1,2-dihydro-benzo[f]isoquinolines was synthesized using
reactions of dialkylbenzylcarbinols and their naphthyl analogs with alkylcyanides. Experiments showed that 1-alkyl-6,7-dimethoxy-3,4-dihydroisoquinolines
typically produce a hypotensive action, while the benzo-annelated structures usually exhibit a hypertensive effects. The most
active compound decreases the arterial pressure in cats by 52 Torr and the effect lasts for about 4 hours.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 3, pp. 15–17, March, 2006. 相似文献
45.
目的:直肠腺瘤和其他疑似为良性的病变应用经肛门内镜切除术并未普及。该项研究旨在评估经肛门内镜切除术的效能和安全性。方法:回顾性研究分析在1993-2004年之间3所斯德哥尔摩医院中经肛门内镜切除术的患,内容包括患自身及病变特性、并发症、随访时间和复发率。结果:180例中共131例行经肛门内镜切除术。160例经组织学诊断为腺瘤,12例为癌瘤,其余8例分别为增生、纤维化或正常黏膜。直肠腺瘤患中,77例仅行单次经肛门内镜切除术,16例因巨大腺瘤而多次行该手术,27例因复发而需另行经肛门内镜切除术或其他手术。中位复发时间为7个月,但未出现直肠癌。16例手术患出现并发症。2例患必须行Hartman手术,1例因肠穿孔,另1例因出血。手术期间无死亡。未复发的中位随访期为32个月(极差0—67)。[编按] 相似文献
46.
47.
48.
49.
AIMS: To examine the effects of agents that alter potassium adenosine triphosphate (KATP) channel activity in beta-cells on cognitive function and counterregulatory hormone responses during acute hypoglycaemia, given the physiological similarities between the pancreatic beta-cell and the hypothalamic glucose-sensitive neurones (GSN) and the widespread distribution of sulphonylurea receptors in neuronal cells throughout the brain. METHODS: Ten healthy males were studied on four occasions and in random order underwent three stepped hypoglycaemic (plasma glucose aims: 3.4, 2.8, 2.4 mmol/l) and one euglycaemic (plasma glucose aim: 5 mmol/l) insulin clamps. Prior to each hypoglycaemic study, volunteers received either 10 mg glibenclamide, or 5 mg/kg diazoxide or placebo orally. Cognitive function, symptom scores and counterregulatory hormone responses were measured at each glycaemic level. RESULTS: There was no statistically significant effect of either drug on the symptoms generated or the counterregulatory hormonal response during hypoglycaemia. However, cognitive function was better preserved during hypoglycaemia in the glibenclamide-treated arm, particularly four-choice reaction time which deteriorated at a plasma glucose 2.5 mmol/l compared with 3.0 mmol/l with diazoxide (P = 0.015) and 2.9 mmol/l with placebo (P = 0.114). CONCLUSIONS: Single doses of pharmacological agents which alter membrane KATP channel activity do not affect the counterregulatory response to hypoglycaemia but may modify cognitive function during cerebral glucopenia. The unexpected effects of glibenclamide on cortical function suggest a novel action of sulphonylureas that warrants further investigation. 相似文献
50.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献