全文获取类型
收费全文 | 263506篇 |
免费 | 24529篇 |
国内免费 | 20610篇 |
专业分类
耳鼻咽喉 | 2015篇 |
儿科学 | 2309篇 |
妇产科学 | 3005篇 |
基础医学 | 32619篇 |
口腔科学 | 4270篇 |
临床医学 | 37886篇 |
内科学 | 38523篇 |
皮肤病学 | 2395篇 |
神经病学 | 14892篇 |
特种医学 | 9547篇 |
外国民族医学 | 198篇 |
外科学 | 25083篇 |
综合类 | 44060篇 |
现状与发展 | 74篇 |
一般理论 | 27篇 |
预防医学 | 15862篇 |
眼科学 | 8185篇 |
药学 | 28209篇 |
299篇 | |
中国医学 | 15605篇 |
肿瘤学 | 23582篇 |
出版年
2024年 | 937篇 |
2023年 | 4374篇 |
2022年 | 11350篇 |
2021年 | 14081篇 |
2020年 | 10643篇 |
2019年 | 9299篇 |
2018年 | 9672篇 |
2017年 | 8512篇 |
2016年 | 8101篇 |
2015年 | 12177篇 |
2014年 | 14954篇 |
2013年 | 12529篇 |
2012年 | 18727篇 |
2011年 | 21550篇 |
2010年 | 13041篇 |
2009年 | 10072篇 |
2008年 | 13344篇 |
2007年 | 13372篇 |
2006年 | 13608篇 |
2005年 | 13861篇 |
2004年 | 8205篇 |
2003年 | 7608篇 |
2002年 | 6376篇 |
2001年 | 5695篇 |
2000年 | 6422篇 |
1999年 | 7179篇 |
1998年 | 4735篇 |
1997年 | 4754篇 |
1996年 | 3675篇 |
1995年 | 3514篇 |
1994年 | 2896篇 |
1993年 | 1964篇 |
1992年 | 2214篇 |
1991年 | 1844篇 |
1990年 | 1565篇 |
1989年 | 1334篇 |
1988年 | 1133篇 |
1987年 | 991篇 |
1986年 | 748篇 |
1985年 | 609篇 |
1984年 | 348篇 |
1983年 | 214篇 |
1982年 | 115篇 |
1981年 | 128篇 |
1980年 | 82篇 |
1979年 | 90篇 |
1975年 | 1篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Min Zhang Wen-Bin Li Jin-Xia Geng Qing-Jun Li Xiao-Cai Sun Xiao-Hui Xian Jie Qi Shu-Qin Li 《Journal of cerebral blood flow and metabolism》2007,27(7):1352-1368
Glial glutamate transporter-1 (GLT-1) plays an essential role in removing glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. To explore whether GLT-1 plays a role in the acquisition of brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP), the present study was undertaken to observe in vivo changes in the expression of GLT-1 and glial fibrillary acidic protein (GFAP) in the CA1 hippocampus during the induction of BIT, and the effect of dihydrokainate (DHK), an inhibitor of GLT-1, on the acquisition of BIT in rats. Immunohistochemistry for GFAP showed that the processes of astrocytes were prolonged after a CIP 2 days before the lethal ischemic insult, which could protect pyramidal neurons in the CA1 hippocampus against delayed neuronal death induced normally by lethal ischemic insult. The prolonged processes extended into the area between the pyramidal neurons and tightly surrounded them. These changes made the pyramidal layer look like a 'shape grid'. Simultaneously, the prolonged and extended processes showed a great deal of GLT-1. Western blotting analysis showed significant upregulation of GLT-1 expression after the CIP, especially when it was administered 2 days before the subsequent lethal ischemic insult. Neuropathological evaluation by thionin staining showed that DHK dose-dependently blocked the protective role of CIP against delayed neuronal death induced normally by lethal brain ischemia. It might be concluded that the surrounding of pyramidal neurons by astrocytes and upregulation of GLT-1 induced by CIP played an important role in the acquisition of the BIT induced by CIP. 相似文献
62.
63.
Z-Y Sun J Wei L Xie Y Shen S-Z Liu G-Z Ju J-P Shi Y-Q Yu X Zhang Q Xu G P Hemmings 《European psychiatry》2004,19(6):354-357
The present study was designed to detect three single nucleotide polymorphisms (SNPs) located on 22q11 that was thought as being of particularly importance for genetic research into schizophrenia. We recruited a total of 176 Chinese family trios of Han descent, consisting of mothers, fathers and affected offspring with schizophrenia for the genetic analysis. The transmission disequilibrium test (TDT) showed that of three SNPs, rs10314 in the 3'-untranslated region of the CLDN5 locus was associated with schizophrenia (chi(2) = 4.75, P = 0.029). The other two SNPs, rs1548359 present in the CDC45L locus centromeric of rs10314 and rs739371 in the 5'-flanking region of the CLDN5 locus, did not show such an association. The global chi-square (chi(2)) test showed that the 3-SNP haplotype system was not associated with schizophrenia although the 1-df test for individual haplotypes showed that the rs1548359(C)-rs10314(G)-rs739371(C) haplotype was excessively non-transmitted (chi(2) = 5.32, P = 0.02). Because the claudin proteins are a major component for barrier-forming tight junctions that could play a crucial role in response to changing natural, physiological and pathological conditions, the CLDN5 association with schizophrenia may be an important clue leading to look into a meeting point of genetic and environmental factors. 相似文献
64.
双侧内囊前肢毁损术治疗难治性强迫症疗效及随访研究 总被引:9,自引:0,他引:9
目的 对难治性强迫症进行双侧内囊前肢毁损术治疗 ,评定手术疗效并进行 2年随访 ,以进一步探索脑外科手术对难治性强迫症的疗效 ,并探讨手术治疗的良好适应症。方法 对 2 8例难治性强迫症患者进行双侧内囊前肢毁损术治疗 ,并分别在手术前、手术后二周、手术后三月、手术后六月、手术后一年、手术后二年进行Y BOCS、HAMA、HAMD量表评定及术后疗效评定。结果 (1)强迫症患者手术后各期Y BOCS评分、HAMA评分与手术前比较均下降 ,有极显著差异 (P <0 .0 0 1) ;(2 )手术后各期Y BOCS的强迫思维评分均有明显下降 (P <0 .0 0 1) ,强迫行为在手术后 1年和 2年 ,与手术前比较无明显改变 (P >0 .0 5 ) ;(3)手术后 2年的总有效率为 5 3.5 % ,明显低于手术后 3月的总有效率 (P <0 .0 1)。结论 采用双侧内囊毁损术有相当的治疗效果 ,对于难治性强迫症患者可作为一种补充治疗手段 ;手术治疗对强迫行为的长期疗效较差 ,以严重的强迫思维为主的难治性强迫症患者为手术更好的适应症。 相似文献
65.
神经、精神因素对儿科疾病的影响 总被引:1,自引:0,他引:1
儿童时期是人生一个重要而又特殊的阶段 ,身体正处于不断的生长发育之中。神经系统尤其是脑组织是人类精神心理活动和行为的物质基础。小儿神经系统的发育尚未成熟 ,功能也不够完善和稳定 ,精神心理状态易受到周围环境、家庭、学校或社会等诸多因素的影响 ,特别是近 2 0年来我国独生子女明显增多 ,对各种情况变化缺乏足够的适应能力和承受能力 ,因此与成人相比较易发生心理行为障碍。神经、精神因素不仅对许多儿科疾病的发生、发展有着重要的影响 ,而且还可以作为主要的致病因素引起一些疾病。众所周知 ,在儿科临床上一些较常见的疾病如儿童… 相似文献
66.
小包装全氟丙烷气体动力学实验研究 总被引:1,自引:0,他引:1
为检验塑料小包装全氟丙烷气体(C3F8)在不同包装和储存方法时浓度变化,将装有5~7mlC3F8的聚氯乙烯小袋,根据不同储藏温度和外包装方法随机分成四组:(1)22℃聚乙烯外包装,(2)36℃聚乙烯外包装,(3)22℃铝箔真空外包装,(4)-29℃聚乙烯外包装;每一组C3F8小袋气体存放一定时间后,应用气相色谱分析方法进行浓度测量。结果:第3组C3F8浓度最高和稳定,第2组浓度随放置时间降低最明显,第4组是临床应用气体的储藏和包装方法,其30天样本浓度和第3组相等,但放置一年时浓度降低。结果显示:塑料小包装C3F8予以铝箔真空外包装是一种可行的方法,利于C3F8运输和普及;聚乙烯外包装的C3F8,应放在-29℃保存,时间不超过一年。 相似文献
67.
Principles for managing penetrating craniocerebral injuries caused by firearm missiles 总被引:1,自引:0,他引:1
X Zhang S Y Yi W P Liu Z W Zhang L G Wang A M Li 《Journal of clinical neuroscience》1996,3(3):229-233
Penetrating craniocerebral firearm injuries remain one of the most lethal causes of all trauma and are common both in war or peace time. Data were reviewed for 4140 severely head-injured patients (Glasgow Coma Scale (GCS) scores 3-8) treated at Xi-Jing Hospital between 1973 and 1993; 51 of these patients had acute penetrating craniocerebral injuries caused by firearm missiles. These patients consisted of 46 males (90.2%) and 5 females (9.8%) ranging in age from 3 months to 48 years (median 22.4 years). The lesion types included 2 tangential wounds, 37 tubular wounds and 12 through-and-through wounds. All cases were urgent with the patients in severe and unstable states. After emergency treatment and operation, 5 cases died (9.8%). Follow up studies at three months showed that 23 cases (45.1%) had made a good recovery. Moderate disability, severe disability and vegetative states in this series were 29.4%, 13.7% and 2.0% respectively. Long term follow up studies indicated that 32 were able to resume their occupation. The principles for managing penetrating craniocerebral firearm injuries and suggestions for operation are discussed. 相似文献
68.
本文对SOD的紫外分光光度法测定进行了实用性研究。结果表明,本文方法具有用血量少,重现性好,快速、灵敏,试剂廉价等优点。西宁地区与平原地区人群的比较测定显示,前者SOD活性明显高于后者(P<0.01)。 相似文献
69.
The effect of individual HLA-A and -B mismatches on the generation of cytotoxic T lymphocyte precursors 总被引:2,自引:0,他引:2
In order to study the correlation between HLA mismatches and the cytotoxic T lymphocyte precursor frequency, we used a limiting dilution analysis to determine the CTLp frequencies against individual mismatched HLA-A and -B alloantigens in 21 patients waiting for a renal transplant. Altogether, thirty-three mismatched HLA-A antigens and 55 HLA-B antigens were tested. The CTLp frequencies against mismatches of HLA-B locus antigens were found to be significantly higher than those against HLA-A antigens (P less than 0.002). This may explain why matching for HLA-B antigens is more important for a good renal allograft survival than matching for HLA-A antigens. 相似文献
70.
R. Bataille X. G. Zhang J. Wijdenes J-F Schved B. Klein 《Medical oncology (Northwood, London, England)》1993,10(4):185-188
Because IL-6 has been involved in the pathogenesis of acute monoblastic leukemia, we investigated thein vitro anti-proliferative effect and thein vivo anti-tumoral effect of an anti-IL-6 murine monoclonal antibody (mAb) in a patient with MSB type acute leukemia. In the current study, we clearly show the IL-6 dependence of monoblastic cell viability and proliferationin vitro in short-term cultures of malignant cells and the clinical activity of the anti-IL-6 murine mAb. The complete neutralization of IL-6in vivo was associated with a transient but complete disappearance of malignant monoblastic cells in the peripheral blood, with improvement or even normalization of several other biological parameters of disease activity, No immunization against the anti-IL-6 murine mAb was observed. 相似文献