全文获取类型
收费全文 | 6749篇 |
免费 | 354篇 |
国内免费 | 207篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 169篇 |
妇产科学 | 52篇 |
基础医学 | 670篇 |
口腔科学 | 31篇 |
临床医学 | 801篇 |
内科学 | 1954篇 |
皮肤病学 | 45篇 |
神经病学 | 285篇 |
特种医学 | 69篇 |
外科学 | 262篇 |
综合类 | 839篇 |
预防医学 | 820篇 |
眼科学 | 45篇 |
药学 | 886篇 |
1篇 | |
中国医学 | 286篇 |
肿瘤学 | 82篇 |
出版年
2023年 | 113篇 |
2022年 | 155篇 |
2021年 | 290篇 |
2020年 | 264篇 |
2019年 | 214篇 |
2018年 | 234篇 |
2017年 | 163篇 |
2016年 | 166篇 |
2015年 | 158篇 |
2014年 | 369篇 |
2013年 | 654篇 |
2012年 | 312篇 |
2011年 | 346篇 |
2010年 | 286篇 |
2009年 | 235篇 |
2008年 | 299篇 |
2007年 | 279篇 |
2006年 | 231篇 |
2005年 | 213篇 |
2004年 | 209篇 |
2003年 | 190篇 |
2002年 | 161篇 |
2001年 | 128篇 |
2000年 | 108篇 |
1999年 | 89篇 |
1998年 | 102篇 |
1997年 | 122篇 |
1996年 | 92篇 |
1995年 | 85篇 |
1994年 | 99篇 |
1993年 | 79篇 |
1992年 | 71篇 |
1991年 | 73篇 |
1990年 | 69篇 |
1989年 | 63篇 |
1988年 | 64篇 |
1987年 | 65篇 |
1986年 | 46篇 |
1985年 | 55篇 |
1984年 | 53篇 |
1983年 | 39篇 |
1982年 | 40篇 |
1981年 | 29篇 |
1980年 | 37篇 |
1979年 | 27篇 |
1978年 | 22篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1975年 | 15篇 |
1973年 | 11篇 |
排序方式: 共有7310条查询结果,搜索用时 53 毫秒
41.
伤湿胶囊抗炎镇痛作用的实验研究 总被引:1,自引:1,他引:0
为评价伤湿胶囊的抗炎镇痛功效,采用蛋清致大鼠足跖浮肿法、二甲苯致小鼠耳肿胀法、硫酸组胺致小鼠皮肤毛细血管通透性法、大鼠棉球肉芽肿法、小鼠热板法及醋酸扭体法,观察伤湿胶囊的抗炎、镇痛作用,并与伤湿丸比较;用改良Zak法测定小鼠肾上腺中胆固醇含量,结果显示伤湿胶囊对大鼠足肿胀、小鼠耳肿胀及皮肤毛细血管通透性均有显著抑制作用,可明显提高小鼠热板法致痛的痛闷,减少醋酸致痛小鼠的扭体次数,其效果比伤湿丸好;测得小鼠肾上腺中的胆固醇含量明显降低,对大鼠棉球肉芽肿无明显抑制作用,说明伤湿胶囊对急性炎症有较好的抗炎作用和镇痛作用,疗效优于伤湿丸组;对慢性炎症无明显的抑制作用,其抗炎机理初步认为与兴奋肾上腺皮质有关。 相似文献
42.
Role of Isoflavones in the Hypocholesterolemic Effect of Soy 总被引:2,自引:0,他引:2
Isabelle Demonty PhD Benoît Lamarche PhD Peter J. H. Jones PhD 《Nutrition reviews》2003,61(6):189-203
Epidemiologic data suggest an inverse relationship between the consumption of soy isoflavones and cardiovascular disease risk. The aims of this review are to determine if isoflavones play a role in the hypocholesterolemic effect of soy and whether the studies realized with that scope were adequately designed. In humans, most studies have been performed in postmenopausal women. The results are inconsistent, however; some studies show a decrease in total cholesterol and low-density lipoprotein concentrations, and an increase in high-density lipoprotein levels, and other investigations fail to show any beneficial effect of soy isoflavones on lipid profiles. In most studies, beneficial effects could not be attributed with certainty to soy isoflavones. If these components have any health-protecting effect in humans, it is small in comparison with the effect of soy protein itself. There are currently not enough data to recommend the consumption of isoflavone supplements to lower plasma cholesterol levels. 相似文献
43.
Summary The distribution and composition of lipoproteins spanning the very low density and low density lipoprotein spectra have been analysed in ten poorly-controlled, male, Type 2 (non-insulin-dependent), diabetic patients pre-disposed to mild, secondary hypertriglyceridaemia. As compared to age-matched control subjects, the diabetic patients displayed grossly modified, distinctly atherogenic lipoprotein profiles. Modifications were not limited to the very low density lipoprotein profile, as would be expected from the pre-treatment hypertriglyceridaemia. There was also an aberrant low density lipoprotein profile, which was not evident from plasma cholesterol measurements, especially as the diabetic patients at entry were well matched to control subjects with respect to plasma levels of this lipid. Compositional abnormalities were also observed in the poorly-controlled diabetic group, although these were less marked than the distributional changes. There were substantial improvements of the abnormalities detailed above, even over a short treatment period (two weeks), with therapy designed primarily to ameliorate metabolic control. The data suggest that, in the presence of poor metabolic control and hypertriglyceridaemia, occult, atherogenic modifications of low density lipoproteins can occur. The results argue in favour of strict control of triglyceride levels even in diabetic patients with apparently acceptable cholesterol levels. 相似文献
44.
Tarek Sadek Hakim Mazouz Hedi Bahloul Roxana Oprisiu Najeh El Esper Isabelle El Esper Francis Boitte Michel Brazier Philippe Moriniere Albert Fournier 《Nephrology, dialysis, transplantation》2003,18(3):582-588
BACKGROUND: Sevelamer hydrochloride was recently proposed as a phosphate binder to prevent hypercalcaemia in place of calcium alkaline salts in dialysis patients. So far, it has been evaluated only in patients receiving calcitriol, without comparison with CaCO(3) alone, although the latter was found to be as effective as the combination of calcitriol and Al(OH)(3) in suppressing parathyroid hormone (PTH) without inducing hypercalcaemia and to have a better lowering effect on serum phosphate. Moreover, this bile salt binder may decrease serum 25-OH vitamin D. Therefore, we compared for 5 months two strategies for controlling moderate hyperparathyroidism: CaCO(3) alone vs sevelamer in conjunction with measures to increase calcium balance. METHODS: Forty-two patients were randomized: 21 continued their treatment with 4.8 g/day CaCO(3) and 21 were switched to sevelamer (initial dose: 2.4 g/day, increased to 4.4 g/day). Each month, when serum-corrected calcium decreased below 2.30 mmol/l, dialysate calcium was increased or alphacalcidol was given at each dialysis session, according to serum PO(4) levels. The following parameters were monitored: serum Ca, PO(4), bicarbonate and protein, weekly; and serum PTH, 25-OH vitamin D and total, LDL and HDL cholesterol monthly. RESULTS: Except for higher serum phosphate at month 1, lower serum bicarbonate at month 2 and lower LDL cholesterol at month 5 in the sevelamer group, no difference was found between the two groups. Compared with baseline levels, PTH increased and 25-OH vitamin D decreased significantly in both groups, these two parameters being inversely correlated. CONCLUSIONS: Given comparable control of plasma calcium, phosphate and 25-OH vitamin D, PTH control is comparable in both strategies. Sevelamer does not induce greater vitamin D depletion than CaCO(3). The transient decrease of serum bicarbonate after discontinuation of CaCO(3) in the sevelamer group suggests a less optimal prevention of acidosis. The sevelamer-induced decrease in LDL cholesterol gives this drug a potential advantage in cardiovascular prevention. 相似文献
45.
将Wistar大鼠随机分成氧化胆固醇组(Och)、纯胆固醇组(Pch)和对照组,分别用氧化胆固醇混合物(250mg/kg bw/d)、纯胆固醇(250mg/kg bw/d)以及悬浮固醇用的明胶液体给大鼠灌胃,连续二天。于第二次灌胃后18小时,从大鼠尾静脉注射伊文思兰溶液,并于注射后2小时处死;取出主动脉用荧光显微分光光度术测定主动脉内膜的通透性。此外,另一部分动物在第二次灌胃后24小时处死,取出主动脉作扫描电镜的内膜观察。结果表明,Och大鼠主动脉内膜的通透性显著高于Pch组与对照组大鼠(P<0.01),而Pch组大鼠主动脉内膜的通透性和对照组无显著差异(P>0.05)。 相似文献
46.
用Brevibacterium sp.DGCDC-82在7L发酵罐中分批培养.分别对添加剂吐温-80、培养温度、培养基的pH、通风量和搅拌速度在胆固醇氧化酶的生产中的影响进行了研究.结果显示以上条件均对产酶有影响.在不同的发酵阶段改变发酵操作条件,发酵20 h最高酶活可达1203U/L,生产强度可达60 U/(L·h).既有效地提高了胆固醇氧化酶的产量,又防止了发酵过程中的泡沫外溢. 相似文献
47.
通过平板初筛和摇瓶复筛,从371株菌中筛得一株有工业生产价值的胆固醇酯酶产生菌,并对它进行了发酵条件的研究。用所获得的胆固醇酯酶配制的三酶试剂具有良好的稳定性,适用于临床检测。 相似文献
48.
A multi-institutional study 'Pathobiological Determinants of Atherosclerosis in Youth' (PDAY) was initiated to document the natural history of atherosclerosis, its relationship to risk factors, and pathobiology of lesion development in young subjects. Pathology laboratories in nine centers collected arteries and tissues from over 2000 persons from 15 through 34 years of age whose deaths were attributed to homicides, accidents, or suicides. Arteries were evaluated for lesions, and risk factors were analyzed in a central laboratory. Postmortem risk factors included serum lipoproteins, serum thio-cyanate (smoking), glycohemoglobin (diabetes), thickness of panniculus adiposus (obesity), small renal artery changes (hypertension) and apoprotein isoforms. This study documents the development of atherosclerosis at an early age. It also shows that the recognized risk factors for coronary heart disease are associated with lesion development in the arteries of these young subjects. The PDAY study has a counterpart in Japan where the development of atherosclerosis has been studied in young subjects. This Japanese study, in a population in which coronary heart disease has not yet become a major epidemic, has findings quite similar to the findings from the PDAY study. Studies of atherosclerosis in both Japan and the USA provide strong justification for reducing risk factors in young persons. 相似文献
49.
Abstract. Objectives. To evaluate lipids and lipoproteins as risk factors for coronary heart disease (CHD) in older men with non-insulin-dependent diabetes (NIDDM) or abnormal glucose tolerance compared with normoglycaemic men. Design. A prospective, population-based cohort study based on the lipoprotein examination (1970–72) of the Honolulu Heart Program. Follow-up was through to December 1988. Setting. Honolulu, Hawaii. Subjects. Japanese-American men, ages 51–72 at baseline: 2042 with 1 h glucose < 12.5 mmol l?1 (normal group); 376 on oral hypoglycaemic agents or with 1 h glucose ≥ 12.5 mmol l?1 after 50 g oral glucose challenge (abnormal glucose tolerance group). None had prevalent coronary heart disease (CHD) or stroke at baseline. Main outcome measures. Incident CHD: definite nonfatal myocardial infarction (MI) or fatal CHD. Results. There were 221 incident cases in the normal group, and 65 in the abnormal glucose tolerance group. Total and high-density lipoprotein (HDL) cholesterol were significant predictors of incident CHD in men with NIDDM or abnormal glucose tolerance after controlling for age, body-mass index, systolic blood pressure, pack-years of cigarettes and alcohol consumption (P < 0.05). Total, low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) cholesterol were significant predictors in normal men, and HDL cholesterol was of borderline significance. Conclusions. Abnormal lipids and lipoproteins are significant, independent predictors of CHD in subjects with NIDDM or abnormal glucose tolerance. Attention to lipid and lipoproteins as CHD risk factors should be part of clinical management of these patients. 相似文献
50.
薄层扫描法测定食物中胆固醇的含量 总被引:1,自引:0,他引:1
本文探讨食物中胆固醇的薄层光密度法的测定。用硅胶G与0.3%CMC-Na按1:2.2比例制成薄层板,石油醚-乙醚--冰醋酸(7:3:0.1)为展开剂,5%磷钼酸乙醇溶液显色,日本岛津CS-910型薄层扫描仪定量扫描,测得精神异系数(RDS%)为2.92。稳定性变异系数(RSD%)为2.35,加嘏率在87.95-94.29%范围内。与气相色谱法(其回收率在92-103%范围)比较,结果相接近,该法简 相似文献