全文获取类型
收费全文 | 3397244篇 |
免费 | 253013篇 |
国内免费 | 5077篇 |
专业分类
耳鼻咽喉 | 47272篇 |
儿科学 | 111293篇 |
妇产科学 | 93983篇 |
基础医学 | 493338篇 |
口腔科学 | 97100篇 |
临床医学 | 307265篇 |
内科学 | 651568篇 |
皮肤病学 | 74296篇 |
神经病学 | 271389篇 |
特种医学 | 129972篇 |
外国民族医学 | 902篇 |
外科学 | 510718篇 |
综合类 | 76616篇 |
现状与发展 | 13篇 |
一般理论 | 1314篇 |
预防医学 | 268125篇 |
眼科学 | 79717篇 |
药学 | 254379篇 |
13篇 | |
中国医学 | 6375篇 |
肿瘤学 | 179686篇 |
出版年
2018年 | 36093篇 |
2017年 | 27500篇 |
2016年 | 30824篇 |
2015年 | 35081篇 |
2014年 | 49268篇 |
2013年 | 74490篇 |
2012年 | 102010篇 |
2011年 | 108333篇 |
2010年 | 64359篇 |
2009年 | 61031篇 |
2008年 | 102154篇 |
2007年 | 108621篇 |
2006年 | 109706篇 |
2005年 | 106726篇 |
2004年 | 103196篇 |
2003年 | 98806篇 |
2002年 | 96318篇 |
2001年 | 151355篇 |
2000年 | 156075篇 |
1999年 | 132003篇 |
1998年 | 38445篇 |
1997年 | 34050篇 |
1996年 | 34023篇 |
1995年 | 32549篇 |
1994年 | 30246篇 |
1993年 | 28553篇 |
1992年 | 105570篇 |
1991年 | 103210篇 |
1990年 | 100811篇 |
1989年 | 97430篇 |
1988年 | 90202篇 |
1987年 | 88564篇 |
1986年 | 83730篇 |
1985年 | 80664篇 |
1984年 | 60492篇 |
1983年 | 51874篇 |
1982年 | 30809篇 |
1981年 | 27778篇 |
1979年 | 56849篇 |
1978年 | 40254篇 |
1977年 | 33765篇 |
1976年 | 32168篇 |
1975年 | 34393篇 |
1974年 | 41619篇 |
1973年 | 39804篇 |
1972年 | 37152篇 |
1971年 | 35093篇 |
1970年 | 32364篇 |
1969年 | 30756篇 |
1968年 | 28112篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
G F Sasso M Ceccanti E Nardi G Valicenti M A Savina N Stella F Zacco 《Panminerva medica》1989,31(1):30-33
The activity of LCAT (the controlling enzyme for cholesterol esterification in plasma) is known to be reduced in alcoholic cirrhosis, while little is known about early stage (liver steatosis) alcoholics. In this study, LCAT activity was assayed by Stokke and Norum's method, before and after a 15-day sobriety period, in liver steatosis and in cirrhosis alcoholics. Before alcohol withdrawal, LCAT activity was depressed in both groups. After the sobriety period, LCAT activity was significantly raised in liver steatosis patients, but was still lower than in controls; in cirrhosis patients, it was increased, but not significantly. According to our results, LCAT activity impairment in alcoholic liver disease is sustained by both the hypothesized mechanisms, alcohol-related metabolic disorders and lowered LCAT-enzyme production, but to different degrees, depending on the stage of the disease. In liver steatosis, metabolic disorders play a major role, as a liver-impairment-induced decrease in LCAT production seems rather unlikely, and increased LCAT activity is more likely to be sustained by metabolic normalisation than by any recovery of the damaged liver. However, the lack of improvement in about 20% of patients, and the fairly wide scattering of individual data, suggest a minor LCAT production impairment in liver steatosis too. In cirrhosis, the major role seems to be played by a permanent decrease in LCAT production, as no significant rise in LCAT activity was observed after alcohol withdrawal. However the restored LCAT activity observed in some patients could be related to improvement in the metabolic disorder, thus confirming the effectiveness of this mechnism in cirrhosis too.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
992.
A case of testicular cancer in 2 brothers is reported and a review of the literature about testicular malignancies and etiologic factors in closely related family members is given. The familial incidence of testicular tumor is found to be 3% in twins and 0.6-2.1% in less closely related men. Tumors were of the same histology in 70-77% of the twins, whereas in brothers and in other degrees of relationship tumors of different histology mostly occur. Following the diagnosis of the tumor in the first man, the average interval to presentation of the tumor in the relative was 3.7 years in twins, 7.7 years in nontwin brothers and 13.5 years for less closely related men. The need for a thorough checkup of other family members is advised. 相似文献
993.
Irradiation of a cytosolic fraction from vascular smooth muscle in the presence of [3H]felodipine resulted in the labelling of a protein with an apparent molecular weight of 62 kDa. The labelling was seen on UV-irradiation at 360 nm, but not at 254, 278 or at wavelengths above 410 nm. The photolabelling was enhanced in the absence of oxygen. In cytosolic fractions prepared from porcine liver, cardiac and skeletal muscle no photoaffinity labelling of proteins between 90 and 45 kDa could be demonstrated. The results suggest that felodipine is a photoaffinity ligand and that felodipine binds to a soluble protein present in vascular smooth muscle but not in the other tissues tested. 相似文献
994.
Concomitants of excess coronary deaths--major risk factor and lifestyle findings from 10,359 men and women in the Scottish Heart Health Study 总被引:9,自引:0,他引:9
The Scottish Heart Health Study is a study of lifestyle and coronary heart disease risk factors in 10,359 men and women aged 40-59 years, in 22 districts of Scotland. The study was conducted during 1984-86, when Scotland had the highest national coronary heart disease mortality reported by the World Health Organisation. A self-completed questionnaire, complemented by a 40 minute visit to a survey clinic, staffed by nurses, enabled the classical major risk factors and some more newly described ones to be measured. The study emphasised quality control and representativeness, and incorporated a World Health Organisation protocol for measurement of key items to allow comparisons in place and time, and therefore also to provide a definitive baseline against which interventions can be assessed. This paper describes the overall findings. Current cigarette smokers constitute 39% of men and 38% of women, higher levels than those reported in England but lower than previous Scottish reports. Mean blood pressure levels were 134/84 mmHg for men and 131/81 mmHg in women, lower than in British studies of the 1960s and 1970s. Mean body mass index levels, 26.1 Kg/m2 in men and 25.7 Kg/m2 in women, were not high by international standards. However, mean serum cholesterol levels were 6.4 mmol/l in men and 6.6 mmol/l in women--as high as those in previous British studies and high by international standards. Levels of high density lipoprotein cholesterol, non-fasting triglycerides and fibrinogen are also reported. Physical activity both at work and in leisure time was low.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
995.
996.
997.
A modified technique for the repair of moderate to severe cicatricial entropion has been developed. This method is unique, as it involves the creation of a bipedicled tarsoconjunctival advancement flap. The technique avoids the causes of surgical failure seen with standard tarsal fracturing procedures. 相似文献
998.
With some, but not all, types and intensities of exercise, lactate accumulates in the blood and in the muscles engaged in the exercise. A great deal of attention has been directed towards attempting to understand the dynamics of lactate production and removal at the onset of exercise, during exercise, and during the recovery process following exercise. It has been hoped that an unravelling of these events would provide a key to understanding cellular metabolism and its regulation during exercise. The purpose of this introductory paper to a symposium on lactate is to present a brief overview of some of the conditions that influence the rate and magnitude of lactate accumulation during exercise. It is pointed out that many conditions influence the rate and magnitude of the accumulation of lactate in blood and muscles. Included are diet, state of physical fitness, and the type and duration of the exercise. We have cautioned against trying to evaluate the state of oxygen delivery to muscle and the state of tissue oxygenation from the appearance of lactate in blood. We have pointed out the positive aspects of lactate production based on how it augments the cellular supply of ATP, thereby allowing for high intensity exercise, and also the negative aspects that develop as a result the reduction in pH which adversely influences many cellular processes essential for muscular activity. 相似文献
999.
1000.