全文获取类型
收费全文 | 53430篇 |
免费 | 5821篇 |
国内免费 | 4312篇 |
专业分类
耳鼻咽喉 | 451篇 |
儿科学 | 771篇 |
妇产科学 | 597篇 |
基础医学 | 5585篇 |
口腔科学 | 1000篇 |
临床医学 | 6993篇 |
内科学 | 7477篇 |
皮肤病学 | 374篇 |
神经病学 | 2564篇 |
特种医学 | 1842篇 |
外国民族医学 | 33篇 |
外科学 | 4960篇 |
综合类 | 10680篇 |
现状与发展 | 19篇 |
一般理论 | 2篇 |
预防医学 | 4213篇 |
眼科学 | 1345篇 |
药学 | 6116篇 |
70篇 | |
中国医学 | 3940篇 |
肿瘤学 | 4531篇 |
出版年
2024年 | 259篇 |
2023年 | 1011篇 |
2022年 | 2483篇 |
2021年 | 3122篇 |
2020年 | 2383篇 |
2019年 | 1987篇 |
2018年 | 1969篇 |
2017年 | 1970篇 |
2016年 | 1788篇 |
2015年 | 2777篇 |
2014年 | 3178篇 |
2013年 | 2989篇 |
2012年 | 4378篇 |
2011年 | 4606篇 |
2010年 | 3174篇 |
2009年 | 2746篇 |
2008年 | 3072篇 |
2007年 | 2799篇 |
2006年 | 2662篇 |
2005年 | 2392篇 |
2004年 | 1714篇 |
2003年 | 1619篇 |
2002年 | 1351篇 |
2001年 | 1139篇 |
2000年 | 1049篇 |
1999年 | 987篇 |
1998年 | 584篇 |
1997年 | 546篇 |
1996年 | 449篇 |
1995年 | 445篇 |
1994年 | 351篇 |
1993年 | 211篇 |
1992年 | 255篇 |
1991年 | 221篇 |
1990年 | 171篇 |
1989年 | 139篇 |
1988年 | 152篇 |
1987年 | 120篇 |
1986年 | 87篇 |
1985年 | 70篇 |
1984年 | 33篇 |
1983年 | 30篇 |
1982年 | 20篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 15篇 |
1978年 | 9篇 |
1972年 | 3篇 |
1970年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
采用20~200U/ml的重组人肿瘤坏死因子(rhTNF-α)处理体外液相培养的人早幼粒白血病细胞珠HL-60,观察到50~200U/ml的小剂量TNF具有诱导其向单核-巨噬细胞途径分化及抑制其增殖的效应。采用细胞总RNA打点杂交技术检测1~100U/mlTNF诱导HL-60细胞早期(12小时内)对其c-myc,c-fos原癌基因表达的影响,发现TNF可抑制c-mycmRNA水平及c-fos短暂性表达增高。结果表明此小剂量rhTNF-α具有诱导白血病细胞分化的效应及调控多癌基因表达的作用。 相似文献
52.
53.
54.
55.
Weijiang Zhao Fang Yuan Guilin Li Zhongfang Shi Yun Cui Yazhuo Zhang Zhongcheng Wang 《中国神经再生研究》2007,2(5):276-280
BACKGROUND: During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin (PRL) and may promote formation of prolactin neoplasia in pituitary anterior lobe.
OBJECTIVE: To observe the effect of diethylstilbestrol (DES) on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats.
DESIGN: Observational contrast animal study.
SETTING: Beijing Neurosurgical Institute.
MATERIALS: A total of 21 female Wistar rats, 3 weeks old weighing 70–80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at (24±1)℃ and a humidity of (55±5)%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan.
METHODS: The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil (1 mL/kg, twice a week) for 16 weeks; DES group, where animals were administered with DES (5 mg/kg, twice a week) for 16 weeks; DES + vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil (1 mL/kg, twice a week) for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin.
MAIN OUTCOME MEASURES: ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue.
RESULTS: All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination: Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone (ACTH) was increased in both DES group and DES + vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES + vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue: Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissues were confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES + vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES.
CONCLUSION: A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe. 相似文献
56.
57.
浙江医科大学附二院门诊处方中精神药物使用调查 总被引:1,自引:0,他引:1
本文对浙江医科大学附属二院1993年7月间31378张合格处方进行统计分析,并用限定日剂量(DDD)和药物使用指数(DUI)为指标,分析镇静催眠药物使用情况。结果表明苯二氮 类药方2067张,占总处方量的6.59%,巴比妥类药方49张,占0.16%,麻醉药方111张;占0.35%。苯二氮 类药方中.女性处方量1202张,男性处方量865张,男、女组间比较有显著性差异。苯二氮 类药方多分布在神经内科,常用的药有舒乐安定和阿普唑仑。九种常用的苯二氮 类药和麻醉性镇痛药的DUI均小于1。提示药物滥用现象少见,该院对这类药物的管理比较严格。麻醉性镇痛药中二氢埃托啡处方占67.57%。 相似文献
58.
作者通过对1例冲动症案例的分析,结合文献报道,初步阐述了冲动症的概念范围、临床特征与诊断标准。并讨论了其与强迫症、性心理障碍、正常性犯罪之间的区别和责任能力的评定。 相似文献
59.
研究了不同温度、浓度条件下,顺丁烯二酸(顺酸)非催化反应网络,即顺酸可生成反丁烯二酸(反酸)和苹果酸,反酸与苹果酸存在可逆反应。建立了该反应网络的动力学模型。测定了不同反应条件下顺酸、反酸和苹果酸浓度随时间变化的规律,据此,动力学参数进行了估值。 相似文献
60.
Attenuation of myocardial injury due to oxygen free radicals(OFR) by pretreatment with OFR or calcitonin gene-related peptide 总被引:3,自引:0,他引:3
目的:研究氧自由基(OFR)及降钙素基因相关肽(CGRP)预处置对OFR所致离体大鼠心脏损伤的拮抗作用.方法:Langendorf法灌流心脏,电解KH液产生OFR.结果:CGRP或OFR预处置减轻OFR所致心脏收缩功能下降,冠脉流量减少和肌酸激酶(CK)释放增加.蛋白激酶C(PKC)抑制剂H7可取消OFR预处置的心脏保护作用(对照组,OFR损伤组,OFR预处置组,H7加OFR预处置组及H7组的CK释放量分别是110±7,215±23,169±14,240±30,113±19U·L-1).结论:OFR或CGRP预处置对OFR所致心肌损伤具有拮抗作用,该作用与PKC激活有关. 相似文献