全文获取类型
收费全文 | 2721篇 |
免费 | 313篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 319篇 |
妇产科学 | 35篇 |
基础医学 | 122篇 |
口腔科学 | 13篇 |
临床医学 | 138篇 |
内科学 | 158篇 |
皮肤病学 | 21篇 |
神经病学 | 23篇 |
特种医学 | 35篇 |
外科学 | 122篇 |
综合类 | 502篇 |
预防医学 | 342篇 |
眼科学 | 59篇 |
药学 | 304篇 |
中国医学 | 978篇 |
肿瘤学 | 25篇 |
出版年
2024年 | 25篇 |
2023年 | 68篇 |
2022年 | 156篇 |
2021年 | 197篇 |
2020年 | 148篇 |
2019年 | 109篇 |
2018年 | 103篇 |
2017年 | 149篇 |
2016年 | 135篇 |
2015年 | 132篇 |
2014年 | 238篇 |
2013年 | 207篇 |
2012年 | 203篇 |
2011年 | 202篇 |
2010年 | 167篇 |
2009年 | 131篇 |
2008年 | 105篇 |
2007年 | 123篇 |
2006年 | 80篇 |
2005年 | 57篇 |
2004年 | 61篇 |
2003年 | 50篇 |
2002年 | 29篇 |
2001年 | 27篇 |
2000年 | 34篇 |
1999年 | 24篇 |
1998年 | 22篇 |
1997年 | 19篇 |
1996年 | 28篇 |
1995年 | 17篇 |
1994年 | 20篇 |
1993年 | 11篇 |
1992年 | 16篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 4篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 3篇 |
排序方式: 共有3203条查询结果,搜索用时 15 毫秒
1.
采用聚乙烯硫酸(PVS)沉淀法测定血清低密度脂蛋白胆固醇(LDL-C)值,同时应用Friedewald公式计算LDL-C含量,并对两法结果进行比较分析,提出当甘油三脂(TG)<4.52mmol/L时,F公式计算法可代替PVS法,当TG>4.52mmol/L时,不宜用F公式计算LDL-C的值。 相似文献
2.
QuantitativerelationshipbetweenpupillaryreflexfeatureanditsdiopterinretinoscopyXuShang(徐上);JiShangnian(计尚年)(DepartmentofOphth... 相似文献
3.
Allergic reactions to raw, pasteurized, and homogenized/pasteurized cow milk: a comparison 总被引:1,自引:0,他引:1
Five children aged 12-40 months with IgE-mediated adverse reactions to cow milk (immediate onset clinical pattern of cow milk allergy) were orally challenged double-blind in random order with three different milk preparations processed from the same batch of milk 1) raw untreated cow milk, 2) pasteurized cow milk, 3) homogenized and pasteurized cow milk, and 4) Nutramigen (a commercial hypoallergenic infant formula based on hydrolysed casein) as placebo. Skin prick tests with the same preparations were also performed. On oral challenge the three different processed milk types provoked significant and similar allergic reactions in each child, and no adverse reactions followed the challenge with placebo (Nutramigen). Skin prick test with the same milk products were positive in all children and comparable to the results with an extract of purified raw cow milk protein (Soluprick), whereas Nutramigen did not elicit any skin reactions. A tendency towards a lower threshold of reaction and larger skin reactions induced by the processed milk preparations might indicate an increased ability of pasteurized and homogenized/pasteurized milk to evoke allergic reactions in patients allergic to milk. 相似文献
4.
Friedrich Manz Hermann Kalhoff Thomas Remer 《Pediatric nephrology (Berlin, Germany)》1997,11(2):231-243
In early infancy, complex disorders of acid base metabolism are more frequent than in any other age group, with a predisposition
to metabolic acidosis due to an age-related low renal capacity for acid excretion and an unphysiologically high actual renal
acid load in nutrition with common formulas. Recently in preterm and small-for-gestational-age infants, persistent maximum
renal net acid excretion (NAE) with subnormal or normal blood acid base status, impaired weight gain, and adaptive hormonal
reactions have been observed. Incipient late metabolic acidosis is one example of a mixed disorder of acid base metabolism
with maximum renal NAE in early infancy. Alkali therapy is highly effective and can be realized both on an individual basis,
using urine pH screening as a diagnostic criterium for maximum renal acid stimulation, or on a general preventive level using
modified standard formula with a reduced actual renal NAE similar to that seen on alimentation with human milk. From an integrated
point of view, the low glomerular filtration rate and renal capacity for acid excretion beyond the developmental age of more
than 44 weeks, may well be interpreted as the result of a specific adaptation to breast feeding sparing energy, and thus an
evolutionary advantage for the survival of mother and child.
Received July 10, 1996; received in revised form and accepted October 7, 1996 相似文献
5.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis. 相似文献
6.
复方红芪减方对周围神经再生影响的实验研究 总被引:4,自引:2,他引:2
目的 研究复方红芪提取液进行减方后对周围神经再生的作用。方法 建立钳夹损伤大鼠双侧坐骨神经的动物模型。按术后每日灌服药物的不同将 40只SD雄性大鼠随机均分为 4组。对照组 :灌服生理盐水 ;复方红芪组 :灌服复方红芪提取液 2ml ;减方组 :灌服复方红芪减方后提取液 2ml;补阳还五汤组 :灌服补阳还五汤 2ml。术后 2周及 4周 ,观察坐骨神经功能指数、运动神经传导速度及单位视野有髓神经纤维计数。结果 坐骨神经功能指数 :红芪组和减方组与对照组、红芪组与减方组的差异均有显著意义 (P >0 .0 5 ) ,且减方组优于红芪组 (P >0 .0 5 )。有髓神经纤维计数 :复方红芪组优于对照组 (P<0 0 1) ,减方组明显优于对照组 (P <0 .0 1) ,而红芪组与减方组间无显著差异。运动神经传导速度 :红芪组、减方组、补阳还五汤组与对照组相比 ,均优于对照组 (P <0 .0 5 ) ,但前 3组间无明显差异。结论 复方红芪减方提取液早期可以促进周围神经再生 ,药效更为专一 ,且优于传统方剂补阳还五汤。 相似文献
7.
As a means for assessing cardiac function, electrical field plethysmography (EFP) has been shown to have some features quite
different from electrical impedance plethysmography (EIP). Here the two techniques are compared by using the two systems simultaneously
on a subject and also with independent use in different electrode configurations. The results conform with the view that EIP
is related primarily to volumetric changes of the aorta, whereas EFP is affected predominantly by changes in cardiac dimensions
and orientation. Because of this difference, the standard time differential formula used for EIP is not applicable for the
computation of cardiac output from the EFP waveforms. An alternative method of computation based on the amplitude of the EFP
waveform is suggested. 相似文献
8.
Ninety-one high atopy-risk infants were prospectively followed up to 18 months of age with regard to the development of allergic/atopic manifestations and sensitization. They were randomized into one of two feeding groups, i.e., a hydrolyzed, ultrafiltered cow's milk whey formula, Profylac® ( n = 32), or an ordinary cow's milk formula ( n = 39), for 12 months, started after exclusive breast-feeding for 0–9 (median 6.0) months. Lactating mothers avoided milk, egg, and fish, as did the infants up to 12 months of age. Twenty of the 91 infants were breast-fed exclusively for more than 9 months and regarded as a control group. All infants were followed-up by questionnaires, physical examinations, skin prick tests, and determination of serum total IgE and cow's milk-specific IgE. The frequency of allergic/atopic disease was similar in the three groups. However, all three infants who developed cow's milk allergy with skin symptoms belonged to the cow's milk formula group. The skin prick test with whey hydrolysate was negative in all, while with cow's milk it was positive in eight infants. Growth was similar in the three groups. The study comprises too few infants to allow us to make statistically based statements. However, the difficulties encountered and the limited effects obtained by the use of whey hydrolysate at weaning at about 6 months of age made us conclude that we can spare high atopy-risk families this extra burden. 相似文献
9.
We developed a sensitive sandwich-type ELISA for measuring low levels of cow's milk (CM) β-lactoglobulin. Purified anti-β-lactoglobulin was used as coating antibody and also as second antibody conjugated with alkaline phosphatase. Polyethylene glycol 6000 was added to the incubation buffers to improve sensitivity. The detection limit of the assay was 0.002 μg/l, which is much better than sensitivities reported for other β-lactoglobulin assays. The sensitivity was not impaired by the presence of other CM proteins. The recovery from breast milk was 93% and from the diluting buffer 127%. The coefficient of variation within day was 5–15% and between days 10%. One hour after oral intake of milk, P-lactoglobulin could be detected in the breast milk of three mothers at concentrations of about 1–2 μg/l. Widely different concentrations of β-lactoglobulin were measured in two protein hydrolysates based on CM whey and casein proteins; the observed concentrations were 200 and 0.0056 μg P-lactoglobulinμ/g dry weight, respectively. 相似文献
10.
目的:分析地黄在中药类保健食品中生熟异用下的配方规律。方法:收集国家市场监督管理总局(SAMR)特殊食品信息查询平台公布的生、熟地黄保健食品数据,对其保健功能及中药组方等进行统计,运用Apriori算法和Kulc、不平衡比参数对地黄生熟异用的保健食品配方规律进行分析。结果:保健食品中,生地黄主要用于辅助降血糖,熟地黄主要用于增强免疫力、缓解体力疲劳、改善营养性贫血。在辅助降血糖类生地黄保健食品中,生地黄主要与补气药、补阴药、解表药、解热药配伍,代表性组合为生地黄-黄芪-苦瓜;在增强免疫力类熟地黄保健食品中,熟地黄主要与补气药、补血药、补阴药配伍,代表性组合为熟地黄-党参-阿胶;在缓解体力疲劳类熟地黄保健食品中,熟地黄主要与补气药、补阳药、补阴药配伍,代表性组合为熟地黄-人参-淫羊藿、熟地黄-人参-枸杞子;在改善营养性贫血类熟地黄保健食品中,熟地黄主要与补气药、补血药配伍,代表性组合为熟地黄-黄芪-阿胶、熟地黄-黄芪-当归。结论:地黄在保健食品中的使用遵循生熟异用的规律,在不同保健功能中,组方配伍基本符合中医理论和现代医学理论,可为生、熟地黄保健食品研发提供借鉴和依据。 相似文献