全文获取类型
收费全文 | 8409篇 |
免费 | 806篇 |
国内免费 | 148篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 207篇 |
妇产科学 | 81篇 |
基础医学 | 697篇 |
口腔科学 | 90篇 |
临床医学 | 685篇 |
内科学 | 1335篇 |
皮肤病学 | 150篇 |
神经病学 | 245篇 |
特种医学 | 728篇 |
外国民族医学 | 2篇 |
外科学 | 1018篇 |
综合类 | 1234篇 |
预防医学 | 1286篇 |
眼科学 | 63篇 |
药学 | 508篇 |
4篇 | |
中国医学 | 757篇 |
肿瘤学 | 216篇 |
出版年
2024年 | 22篇 |
2023年 | 179篇 |
2022年 | 219篇 |
2021年 | 456篇 |
2020年 | 402篇 |
2019年 | 366篇 |
2018年 | 360篇 |
2017年 | 347篇 |
2016年 | 372篇 |
2015年 | 366篇 |
2014年 | 677篇 |
2013年 | 708篇 |
2012年 | 487篇 |
2011年 | 519篇 |
2010年 | 356篇 |
2009年 | 374篇 |
2008年 | 416篇 |
2007年 | 394篇 |
2006年 | 335篇 |
2005年 | 267篇 |
2004年 | 198篇 |
2003年 | 174篇 |
2002年 | 137篇 |
2001年 | 129篇 |
2000年 | 101篇 |
1999年 | 73篇 |
1998年 | 92篇 |
1997年 | 102篇 |
1996年 | 69篇 |
1995年 | 63篇 |
1994年 | 52篇 |
1993年 | 45篇 |
1992年 | 46篇 |
1991年 | 40篇 |
1990年 | 34篇 |
1989年 | 33篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 23篇 |
1985年 | 34篇 |
1984年 | 40篇 |
1983年 | 19篇 |
1982年 | 21篇 |
1981年 | 23篇 |
1980年 | 16篇 |
1979年 | 15篇 |
1978年 | 22篇 |
1976年 | 16篇 |
1974年 | 13篇 |
1973年 | 15篇 |
排序方式: 共有9363条查询结果,搜索用时 156 毫秒
51.
52.
"Chronic painter''s syndrome". A reanalysis of psychological test data in a group of diagnosed cases, based on comparisons with matched controls 总被引:4,自引:0,他引:4
Twenty solvent-exposed workers, most of them painters, had been diagnosed as cases of toxic encephalopathy in 1978/79. Two years later they were re-examined with an extensive battery of neuropsychological tests. Their performance was unchanged on retesting. We have now compared their test results with those of non-exposed control subjects. Previous impressions of significant intellectual impairment in the solvent-exposed patients could not be confirmed when the influence of age, education, and intelligence was taken into consideration. The present group with presumed toxic encephalopathy is assumed to be representative of other patients who were similarly diagnosed in our department. The presently reanalyzed cases had been diagnosed as brain damaged and reported as such in the literature. Thus, they may have contributed to the formation of the concept of the "chronic painters' syndrome" with dementia. 相似文献
53.
五行学说的方法论价值 总被引:1,自引:0,他引:1
祝世讷 《山东中医药大学学报》1988,(1)
五行学说的价值主要在于其方法论意义。五行模型是对人体自我调节机制的一种表达,反映了机体调节和防卫反应的“自组织原则”、“自主性原则”、“目的性原则”。调整阴阳是典型的矛盾调节,五行调节是典型的反馈调节,五行学说是对阴阳学说必然的补充,有不同于阴阳调节的特点,主要是:多体关系、多种作用、反馈控制、不可逆性、整体稳定等。五行学说不仅符合人体实际,而且符合数学的一些严格规则,取了奇素数中的“5”,五行学说面临的不是存废问题,而是如何发展,一方面要使传统五行学说更加完备,另方面应发展“七行”、“十一行”、“十三行”等新模型,可概称为“N行”。 相似文献
54.
目的:探讨ω-3鱼油脂肪乳剂对重症胰腺炎患者腹内高压及肠黏膜功能的影响。方法:选择驻马店市中心医院重症医学科收治的136例重症胰腺炎患者作为研究对象,进行前瞻性研究,并按照随机数字表法分为对照组和观察组,各68例。其中对照组给予常规治疗法进行治疗,观察组在上述治疗的基础上外加ω-3鱼油脂肪乳剂进行治疗。观察两组患者治疗后病情缓解时间变化,比较两组患者治疗前后肠黏膜功能指标、趋化因子及腹内压水平变化,分析两组患者治疗效果差异。结果:观察组腹痛缓解时间、腹胀缓解时间、肠鸣音恢复时间以及肛门首次排便时间等病情症状明显改善(均P<0.05)。与治疗前相比,两组治疗后的血清肠型脂肪酸结合蛋白(I-FABP)、二胺氧化酶(DAO)、D-乳酸、中性粒细胞趋化因子(CINC)、FKN、单核细胞趋化因子蛋白-1(MCP-1)及乳果糖/甘露醇(L/M)、腹内压水平明显低于对照组,血清三叶因子(ITF)、乳脂球表皮生长因子8(MFG-E8)明显降低,且观察组改善更显著(均P<0.05)。观察组患者治疗有效率为94.12%,明显高于对照组的76.47%(P<0.05)。结论:ω-3鱼油脂肪乳... 相似文献
55.
This paper reviews the literature on the role of dietary fat in calorie intake and body weight gain in humans and laboratory animals. An overview of 40 animal studies which compared growth on high-fat (HF) and high-carbohydrate (HC) solid/powdered diets indicated that the HF diet elicited greater weight gain in 33 out of 40 studies. Enhanced growth on the HF diet was often, but not exclusively, attributable to greater caloric intake. Additional evidence for the growth-enhancing effect of HF diets emerges from "diet option" and "supermarket" feeding studies in rats, and experimental and epidemiological studies in humans. Three principal factors that contribute to the different responses to HF and HC diets are (a) caloric density, (b) sensory properties and palatability, and (c) postabsorptive processing. It is concluded that both calorie intake and metabolic energy expenditure are biased towards weight gain when a HF diet is consumed, and that the high caloric density of high-fat diets plays a primary role in weight gain. Humans may be biologically predisposed to gain weight when a HF diet is consumed. 相似文献
56.
Frances S. Shofer Elizabeth G. Sonnenschein Michael H. Goldschmidt Larry L. Laster Lawrence T. Glickman 《Breast cancer research and treatment》1989,13(1):49-60
Summary Histologic and dietary prognostic factors for survival following naturally occurring breast cancer were studied for 145 pet dogs. Information was collected from the dog's owner and veterinarian regarding medical and reproductive history, nutritional status, treatment, tumor recurrence, and length of survival. The usual intake of all dog and table foods consumed 1 year prior to diagnosis was obtained using a validated quantitative food frequency questionnaire. A histologic malignancy score was derived based on 7 histopathologic criteria. The mean age of the dogs was 10.4 ± 2.5 years; 37% had been ovariohysterectomized prior to diagnosis. Product-limit estimates of survival indicated that 6 factors, namely body conformation 1 year prior to diagnosis (p = 0.03), histologic tumor type (p = 0.004), histologic malignancy score (p = 0.02), histologic invasion (p = 0.002), tumor recurrence (p<0.0001), and completeness of surgery (p = 0.01) were of prognostic significance. In addition, when dogs were characterized by the percent of total calories they derived from fat and protein, the median survival time for dogs in the low fat group (<39%) with protein >27%, 23–27%, and <23% was 3 years, 1.2 years, and 6 months, respectively (p = 0.008). For dogs in the high fat group (39%), there was no difference in survival for the different intake levels of dietary protein (p = 0.84). When these data were fitted to a proportional hazards model, recurrence, histologic score, tumor type, percent of calories derived from protein, fat group, and a protein-fat group interaction term were statistically significant. Predicted 1 year survival for dogs on a low fat diet with 15%, 25%, and 35% of total calories derived from protein was 17%, 69%, and 93%, respectively. 相似文献
57.
G. Winkled A. Döring U. Keil P. Pietinen D. Arveiler J. P. Cambou C. Nuttens J. L. Richard A. Evans R. McClean E. McCrum 《Journal of molecular medicine (Berlin, Germany)》1992,70(10):889-895
Summary The composition of diet and food intakes in four selected European populations were compared. Dietary data (from the World Health Organization Project on Monitoring Trends and Determinants in Cardiovascular Disease) were measured by record methods and were available for middle-aged men in Finland (n = 653), France (n =1128), Northern Ireland (n = 356), and southern Germany (Augsburg region; n = 899). Nutritional variables — which are independent of the absolute energy intake, such as the percentage supply of energy from macronutrients and the ratio of polyunsaturated to saturated fatty acids — were on the whole similar. However, striking differences were found in food intake and in the percentage supply of fat from different foods. The results indicate that detailed knowledge of consumption figures is necessary to develop prudent and acceptable nutrition intervention programs.Abbreviations CHD
coronary heart disease
- MONICA
monitoring trends and determinants in cardiovascular disease
- MUFA
monounsaturated fatty acids
- P/S ratio
ratio of polyunsaturated fatty acids/saturated fatty acids
- PUFA
polyunsaturated fatty acids
- SFA
saturated fatty acids 相似文献
58.
Toshio Nishimura Keizo Tsuruhara Keiko Naito Junko Hirohara Sotokichi Morii 《Pathology international》1989,39(5):281-288
To examine the effect of colchicine on ethionine induced fatty liver, adult female rats were starved overnight and then injected i.p. with 1 g kg ethionine at 11th hour of fasting; then a half of the rats were also injected i.p. with 2.5 mg kg colchicine twice at 3 and 6 h after the single administration of ethionine. Similarly, fasted control rats were injected i.p. with vehicle alone at the above times. All of the rats were sacrificed after a 20 h fast, and the hepatocytes in periportal areas were observed ultra-structurally. In addition, total lipids in the liver tissue were extracted and determined biochemically. Although similar significant increases of triglyceride were observed in the liver tissue of all ethionine-injected rats, the hapatocytes in the group treated with both chemicals had fewer cytoplasmic fat globules (CFG) than those in the group treated with ethionine only. On the other hand, the diameters of markedly increased membrane-bound lipid particles (MLP) in the double treated group were distributed mainly in the range 0.2–0.4 μm, compared with those (0.1-0.2 μm) in the other groups. These findings indicate that colchicine inhibits the development of CFG in ethionine injured hapatocytes. Acta Pathol Jpn 39: 281∼288, 1989. 相似文献
59.
利用光镜、电镜、免疫组化和形态学定量技术动态研究维生素A对大鼠四氯化碳肝纤维化的抑制作用。结果表明,维生素A可减少四氯化碳中毒大鼠肝内纤维连接蛋白和Ⅰ、Ⅲ型胶原沉积,抑制贮脂细胞向成纤维细胞转化,并可明显地减轻肝纤维化程度。本文还对维生素A抑制肝纤维化的机理及意义作了初步探讨。 相似文献
60.
Michael H. Stone Michael E. Rush Harry Lipner 《Pflügers Archiv : European journal of physiology》1978,375(2):147-151
The hormonal levels of the gonadotropins, the weight of selected organs and of the triceps surae as well as body composition were determined in Sprague Dawley rats at 3 and 6 weeks after intensive training with or without a methandrostenelone (Dianabol) supplement (0.35 mg/kg/day). The controls were sedentary rats of similar age and weight at the start of the experiment. The dianabol treated rats in the sedentary and exercise groups had a depression of plasma LH levels. There were no differences in body weight, specific gravity, lean body weight, fat or % fat between the two trained groups. Dianabol had no apparent effect on the measured parameters other than a depression of LH. 相似文献