全文获取类型
收费全文 | 235488篇 |
免费 | 10449篇 |
国内免费 | 3851篇 |
专业分类
耳鼻咽喉 | 2319篇 |
儿科学 | 8067篇 |
妇产科学 | 3258篇 |
基础医学 | 24410篇 |
口腔科学 | 4757篇 |
临床医学 | 21785篇 |
内科学 | 43924篇 |
皮肤病学 | 3387篇 |
神经病学 | 18635篇 |
特种医学 | 5999篇 |
外国民族医学 | 3篇 |
外科学 | 32852篇 |
综合类 | 22018篇 |
现状与发展 | 3篇 |
一般理论 | 4篇 |
预防医学 | 13809篇 |
眼科学 | 4203篇 |
药学 | 23856篇 |
115篇 | |
中国医学 | 10433篇 |
肿瘤学 | 5951篇 |
出版年
2023年 | 1713篇 |
2022年 | 3648篇 |
2021年 | 5814篇 |
2020年 | 4625篇 |
2019年 | 15370篇 |
2018年 | 14847篇 |
2017年 | 8461篇 |
2016年 | 3991篇 |
2015年 | 3667篇 |
2014年 | 7212篇 |
2013年 | 9201篇 |
2012年 | 6563篇 |
2011年 | 6741篇 |
2010年 | 5715篇 |
2009年 | 5465篇 |
2008年 | 5967篇 |
2007年 | 7254篇 |
2006年 | 7137篇 |
2005年 | 6555篇 |
2004年 | 5302篇 |
2003年 | 5080篇 |
2002年 | 4749篇 |
2001年 | 4620篇 |
2000年 | 4525篇 |
1999年 | 4062篇 |
1998年 | 4009篇 |
1997年 | 3317篇 |
1996年 | 3047篇 |
1995年 | 3404篇 |
1994年 | 3132篇 |
1993年 | 2454篇 |
1992年 | 2102篇 |
1991年 | 1976篇 |
1990年 | 1637篇 |
1989年 | 1357篇 |
1988年 | 1362篇 |
1987年 | 1296篇 |
1985年 | 5744篇 |
1984年 | 7582篇 |
1983年 | 6028篇 |
1982年 | 6479篇 |
1981年 | 5853篇 |
1980年 | 5022篇 |
1979年 | 5078篇 |
1978年 | 4176篇 |
1977年 | 3106篇 |
1976年 | 3591篇 |
1975年 | 2770篇 |
1974年 | 2546篇 |
1973年 | 2251篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
921.
922.
研究了LDPE/CPE/炭黑三相复合导电体系的导性能和电流-电压特性。实验结果表明复合体系具有明显的导电渗滤效应,在共混比LDPE/CPE>50/50时,导电性能随CPE含量增加而显著提高,这主要是由于炭黑粒子在LDPE和CPE两组分分中的分布不均匀性所致。 相似文献
923.
C. J. M. Stephens J. P. McFadden M. M. Black R. J. G. Rycroft 《Contact dermatitis》1994,31(2):108-110
Autoimmune progesterone dermatitis is a rare condition, characterized by recurrent premenstrual exacerbations of a dermatosis, in which sensitivity to progesterone can be demonstrated. The sensitizing mechanism is unknown. The aim of this study was to test the hypothesis that cross-sensitivity between steroid groups could induce allergy to endogenous progesterone in these patients. 5 patients with autoimmune progesterone dermatitis and 1 with oestrogen-sensitive dermatitis have been patch tested with a corticosteroid series, conjugated oestrogen 1% in petrolatum (pet.), and 17-α-OH-progesterone 2% pet. There were no immediate or delayed reactions at 2 and 4 days to any steroid group. We have therefore been unable to demonstrate steroid cross-sensitivity, or a use for 17-α-OH-progesterone in the investigation of oestrogen - and progesterone-sensitive dermatoses. 相似文献
924.
Children With Chronic Physical Disorders: Maternal Reports of Their Psychological Adjustment 总被引:7,自引:4,他引:3
Wallander Jan L.; Varni James W.; Babani Lina; Banis Heather Tweddle; Wilcox Karen Thompson 《Journal of pediatric psychology》1988,13(2):197-212
Advances in biomedical science have resulted in dramatic improvementsin the medical care of chronically ill and handicapped children.Past measurement problems have resulted in a lack of clarityregarding the psychological adjustment of these children. Themothers of 270 chronically ill and handicapped children wereadministered the Child Behavior Checklist in an attempt to identifypatterns of behavioral functioning across six pediatric chronicdisorders: juvenile diabetes, spina bifida, hemophilia, chronicobesity, juvenile rheumatoid arthritis, and cerebral palsy.In general, it was found that children in all chronic disordergroups were perceived by their mothers as evidencing on theaverage more behavioral and social competence problems thanexpected based on norms for children in general. However, theirbehavioral and social adjustment was reported as better thanthat of a normative sample of children referred to mental healthclinics. There were essentially no differences between childrenwith different chronic disorders in terms of behavior problemsand social competence. The results were taken to support theview that these children were as a group at risk for adjustmentproblems. They were also discussed in terms of the noncategorialapproach, which suggests that similar psychosocial challengesare faced across pediatric chronic physical disorders. 相似文献
925.
A review is presented about fagaronine, a benzophenanthridine alkaloid responsible for antitumoural activity. Plant source, extraction, biosynthesis, medicinal properties, especially antileukaemic activity, are described. 相似文献
926.
强噪声对大鼠血液粘度血糖及几种酶的影响 总被引:9,自引:0,他引:9
本文检测强噪声刺激12小时大鼠血液流变学九项指标,胆碱酯酶和谷丙转氨酶活力及血糖浓度,与对照组比较,其结果显示:(1)低切粘度,红细胞电泳时间和全血还原粘度明显增高(P<0.05;P<0.05和P<0.01);(2)真性和假性胆碱酯酶活力明显增高(二者均P<0.01);(3)血清谷丙转氨酶活力和血清葡萄糖浓度显著增高(P<0.01和P<0.05)。揭示强噪声作用后机体听觉外系统发生明显变化,长期暴露后必将严重损伤全身性调节功能而引起脏器损害与疾病。 相似文献
927.
Monitoring of skin response to sodium lauryl sulphate: clinical scores versus bioengineering methods
The present trial was designed to evaluate clinical scores (single observer) of sodium lauryl sulphate (SLS)-induced skin irritation in a group of subjects (n = 10) over a 10-day period along with various skin function parameters. In order to avoid significant variations due to secondary phenomena, the following parameters were recorded with non-invasive instruments in this order: skin capacitance (C1; arbitrary units; CM420 Corneometer), transepidermal water loss (TEWL; g/m2.h; Evaporimeter) and laser Doppler flowmetry (CBFV: cutaneous blood flow values; Periflux). All examinations were performed during winter on reclined relaxed subjects present for at least 10 min in a test room with controlled temperature and relative humidity (t degrees: 19.5-20.7 degrees C and RH: 47.3-60.3%). The analysis of differential data (delta = value at tx-value before test; 2-way ANOVA) was made on single parameters as a function of site (volar forearm versus neck) and time (from 24 h after 48-h occlusion with 5% SLS up to 10 days later). The profile of erythema scores over time differed between neck and forearm, but the delta CBFV readings with the laser Doppler instrument did not detect significant site-time interactions. Roughness (blind evaluation with palpating finger) and capacitance readings (delta C1) showed significant differences between sites, but the profile over time was similar in both locations. delta TEWL did not differ according to anatomical location. The reason for different erythema scores on neck and forearm might be related to inherent regional variation of optical properties of the skin or to a substantial contribution of SLS-induced roughness to the readings of erythema.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
928.
旋毛虫幼虫分泌物抗原在小鼠体内诱生肿瘤细胞毒因子的研究 总被引:6,自引:0,他引:6
本文应用L929细胞杀伤法,对注射旋毛虫肌肉期幼虫分泌物(L1ES)的小鼠血清进行了检测,发现L1ES对已注射卡介苗(BCG)或感染旋毛虫的小鼠,均能诱生肿瘤细胞毒因子(TCF),而正常对照鼠则不能发生,表明L1ES诱生TCF需要首先激活巨噬细胞(Mφ)这一基本条件。将L1ES置37℃、1h,56℃、30min或100℃、2min处理后,其诱生TCF的能力均明显高于对照组(P<0.05)。L1ES 相似文献
929.
急性期中风中医诊断与颅脑CT扫描关系分析 总被引:6,自引:1,他引:5
分析325例急性期中风的病类、证名诊断与颅脑CT扫描所见的关系,认为中络、中经以缺血性改变为主,病灶小,病灶周围多清晰或仅见模糊,占位表现不明显或较轻;中腑、中脏以出血性改变为主,病灶大,病灶周围多见水肿或模糊不清,占位表现明显,两者对比差异极显著(P<0.01)。病类诊断与中风的病变部位、病位侧、病灶数目;证名诊断与颅脑CT扫描所见皆关系不大(P>0.05)。 相似文献
930.
环丙沙星治疗急性细菌性痢疾29例临床疗效观察 总被引:5,自引:1,他引:4
食源性急性菌例29例中28例大便培养为弗氏2a志贺氏菌。经2天吡哌酸加TMP短程快速治疗,29例无一例治愈。依据药敏试验改用环丙沙星治疗,其中11例感染严重者先予静脉点滴,每12小时200mg,1 ̄2天,症状好转即改口服,每12小时250mg。另18例口服,疗程均为4天。用药后,平均退热时间1.32天,大便次数恢复正常时间平均2.10天,大便常规正常时间平均2.86天,28例大便培养阳性者,平均阴 相似文献