全文获取类型
收费全文 | 21706篇 |
免费 | 2214篇 |
国内免费 | 1122篇 |
专业分类
耳鼻咽喉 | 157篇 |
儿科学 | 416篇 |
妇产科学 | 119篇 |
基础医学 | 1508篇 |
口腔科学 | 440篇 |
临床医学 | 2528篇 |
内科学 | 1955篇 |
皮肤病学 | 211篇 |
神经病学 | 593篇 |
特种医学 | 1056篇 |
外国民族医学 | 16篇 |
外科学 | 2259篇 |
综合类 | 5242篇 |
现状与发展 | 12篇 |
预防医学 | 2446篇 |
眼科学 | 276篇 |
药学 | 2447篇 |
32篇 | |
中国医学 | 1982篇 |
肿瘤学 | 1347篇 |
出版年
2024年 | 124篇 |
2023年 | 328篇 |
2022年 | 852篇 |
2021年 | 1075篇 |
2020年 | 972篇 |
2019年 | 547篇 |
2018年 | 535篇 |
2017年 | 683篇 |
2016年 | 551篇 |
2015年 | 931篇 |
2014年 | 1223篇 |
2013年 | 1433篇 |
2012年 | 1858篇 |
2011年 | 1827篇 |
2010年 | 1595篇 |
2009年 | 1429篇 |
2008年 | 1486篇 |
2007年 | 1461篇 |
2006年 | 1295篇 |
2005年 | 1077篇 |
2004年 | 776篇 |
2003年 | 638篇 |
2002年 | 559篇 |
2001年 | 513篇 |
2000年 | 425篇 |
1999年 | 297篇 |
1998年 | 101篇 |
1997年 | 94篇 |
1996年 | 78篇 |
1995年 | 59篇 |
1994年 | 42篇 |
1993年 | 29篇 |
1992年 | 28篇 |
1991年 | 18篇 |
1990年 | 23篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 14篇 |
1984年 | 2篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1962年 | 4篇 |
1959年 | 5篇 |
1958年 | 4篇 |
1957年 | 5篇 |
1956年 | 2篇 |
1955年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Lv Y He S Zhang Z Li Y Hu D Zhu K Cheng H Zhou F Chen G Zheng X Li P Ren Y Yin X Cui Y Sun L Yang S Zhang X 《Rheumatology international》2012,32(10):3047-3053
The distribution of complement component 4 (C4) gene copy number (GCN) has been validated in European populations. Meanwhile, C4 gene has been identified as a susceptibility gene for systemic lupus erythematosus (SLE). However, the association and the possible phenotype significance remain to be determined intensely in the Chinese population. This study was designed to validate the distribution of C4 GCNs in Chinese Han and the correlation between C4 GCNs and SLE using quantitative real-time polymerase chain reaction in 924 SLE patients and 1,007 controls. The results presented distribution of C4 GCNs in healthy populations and also showed that lower C4 GCN was a risk factor for SLE and higher C4 GCN was a protective factor against the disease susceptibility, which was similar to the report in the Caucasian population. Furthermore, we found the association between C4A GCN and disease subphenotypes of arthritis with SLE. We conclude that the association of C4 GCN with SLE was replicated in Chinese Han population, which highlighted the importance of C4 in SLE pathogenesis of diverse populations. 相似文献
962.
目的 总结我院干部门诊老年男性患者肾小管功能增龄性变化,并进行相关危险因素分析. 方法 研究对象共229例,分为<80岁组和≥80岁组,排除诊断为慢性肾脏病的患者.测定尿常规、血肌酐、血尿素、尿β2微球蛋白(β2-MG)、尿α1微球蛋白(α1-MG);根据Cockcroft-Gault公式计算估测肾小球滤过率(eGFR).总结年龄与上述指标的相关关系,并对相关危险因素进行多因素Logistic回归分析. 结果 229例患者平均年龄(76±10)岁,其中<80岁组142例,≥80岁组87例.与<80岁组比较,≥80岁组eGFR水平明显降低,分别为(80.3±18.0)ml/min比(55.0±12.7)ml/min(t=9.882,P<0.01);尿比重明显降低(1.016±0.006比1.013±0.006);尿pH值(6.2±0.8比6.6±0.8)、尿β2-MG[(0.96±1.02)mg/L比(2.08±3.56) mg/L]和尿α1-MG[(6.67±3.57)mg/L比(8.71±6.59)mg/L]则明显升高,差异均有统计学意义.相关分析结果显示,eGFR和尿比重与患者年龄分别呈明显负相关(r=0.692和r=-0.280,P<0.01),与尿pH值(r=0.255)、尿32-MG(r=0.262)和尿α1 MG(r=0.228)呈明显正相关(均P<0.01).多因素Logistic回归分析显示冠心病为肾小管功能进展的独立危险因素(OR=4.251,P=0.002). 结论 高龄老年男性患者肾小管功能随着年龄的增长而明显减退,冠心病是肾小管功能进展的独立危险因素. 相似文献
963.
Background: Intraoperative amino acid infusion can attenuate the decrease in core temperature, but the metabolic effects are uncertain. Methods: Thirty-six healthy mongrel dogs undergoing ileectomy under general anesthesia were infused intraoperatively with normal saline or 18 compound amino acids at 6, 12, and 24 kJ·kg(-1)·h(-1) (NS, 6-, 12-, and 24-kJ groups) and studied until 24 h after the operation. Blood glucose, plasma insulin, free fatty acids, and triglyceride concentrations were determined at 7 defined time points. Muscle aminograms, urinary urea, and 3-methylhistidine excretions were measured before and after the operation. Results: Blood glucose and plasma insulin increased amino acid dose dependently during the operation and in the early period after the operation. Free fatty acids were significantly lower in the 12- and 24-kJ groups compared with the NS group at the end of the operation. The negative nitrogen balance was alleviated dose dependently in the amino acid groups on operation day. The urinary 3-methylhistidine decreased significantly during the first 24 h after the operation in the 24-kJ group, while it increased in the other groups with the largest increase in the NS group. Basic, branched-chain, and aromatic amino acids in the vastus lateralis muscle increased dose dependently at the end of the operation in the amino acid groups. Conclusion: Intraoperative amino acid infusion has the dose-dependent effects of increasing blood glucose, inhibiting fat mobilization and muscle protein breakdown. 相似文献
964.
基因芯片分析NTD小鼠细胞周期和凋亡相关基因表达的变化 总被引:1,自引:0,他引:1
目的 筛选神经管缺陷(NTD)发生过程中与正常组织差异表达的细胞周期和细胞凋亡相关基因并作初步功能分析.方法 用含有1 100余个已知基因的中密度芯片比较了胚胎9.5d、10.5 d正常与同期NTD小鼠神经管组织的基因表达差异.结果 通过比较正常E9.5d与E10.5 d获得138个差异表达基因,E9.5 d-NTD获得20个差异,El0.5 d-NTD获得29个差异表达基因,根据基因功能分类包括细胞周期与凋亡相关基因,信号转导基因,转录与翻译调控,能量与代谢基因,热休克基因,基质与骨架蛋白等多种种类.而细胞周期和凋亡相关基因分别占差异基因的25.80%(32/124),45.00%(9/20)及28.57%(8/28).结论 实验证实多类基因参与了NTD的发生、发展过程,细胞周期和凋亡相关基因在神经管异常发育中具有重要作用,对该相关基因群的进一步研究有助于阐释NTD的发病机制. 相似文献
965.
目的 观察杏仁核点燃癫痫大鼠海马区P-糖蛋白(P-gp)表达及苔藓纤维出芽(MFS)的动态变化. 方法 90只大鼠采用随机数字表法分为假手术对照组(10只)、癫痫组(40只)和治疗组(40只),假手术对照组只安装电极,不予刺激;癫痫组和治疗组制作杏仁核点燃模型,治疗组加用左乙拉西坦灌胃治疗[100 mg/(kg·d),2次/d)].采用Timm银染组织化学方法观察海马区MFS,免疫组化法检测P-gp的表达. 结果 (1)成功制造癫痫模型后,在海马CA3区透明层出现异常MFS,其中S1亚组大鼠MFS评分最低,与假手术对照组比较差异无统计学意义(P>0.05);S2亚组大鼠评分开始增高,S4亚组大鼠明显增高,S8亚组大鼠达到高峰,与假手术对照组比较差异均有统计学意义(P<0.05).而治疗组大鼠MFS评分各时间点与假手术对照组比较差异均无统计学意义(P>0.05).(2)癫痫发作后癫痫组大鼠P-gp表达量呈现出逐渐降低的趋势,S1、S2、S4亚组与假手术对照组差异有统计学意义(P<0.05);S8亚组接近正常水平,与假手术对照组比较差异无统计学意义(P>0.05).治疗组大鼠除Y1亚组外,余各亚组P-gp表达量与假手术对照组比较差异均无统计学意义(P>0.0S). 结论 MFS是慢性癫痫形成的重要机制,P-gp是癫痫发生的产物,是癫痫药物耐药的主要原因. 相似文献
966.
Xiaodong Cai Libai Yang Jueqian Zhou Dan Zhu Qiang Guo Ziyi Chen Shuda Chen Liemin Zhou 《中国神经再生研究》2013,8(6):561-568
The Na+-K+-Cl-cotransporter 1 and K+-Cl-cotransporter 2 regulate the levels of intracellular chloride in hippocampal cells.Impaired chloride transport by these proteins is thought to be involved in the pathophysiological mechanisms of mesial temporal lobe epilepsy.Imbalance in the relative expression of these two proteins can lead to a collapse of Cl-homeostasis,resulting in a loss of gamma-aminobutyric acid-ergic inhibition and even epileptiform discharges.In this study,we investigated the expression of Na+-K+-Cl-cotransporter 1 and K+-Cl-cotransporter 2 in the sclerosed hippocampus of patients with mesial temporal lobe epilepsy,using western blot analysis and immunohistochemistry.Compared with the histologically normal hippocampus,the sclerosed hippocampus showed increased Na+-K+-Cl-cotransporter 1 expression and decreased K+-Cl-cotransporter 2 expression,especially in CA2 and the dentate gyrus.The change was more prominent for the Na+-K+-Cl-cotransporter 1 than for the K+-Cl-cotransporter 2.These experimental findings indicate that the balance between intracellular and extracellular chloride may be disturbed in hippocampal sclerosis,contributing to the hyperexcitability underlying epileptic seizures.Changes in Na+-K+-Cl-cotransporter 1 expression seems to be the main contributor.Our study may shed new light on possible therapies for patients with mesial temporal lobe epilepsy with hippocampal sclerosis. 相似文献
967.
Xiaodong Feng Chengmei Liu Qingchuan Guo Yanjie Bai Yafeng Ren Binbin Ren Junmin Bai Lidian Chen 《中国神经再生研究》2013,8(15):1423-1430
BACKGROUND: Stroke presents as a transient or chronic brain dysfunction and is associated with high morbidity and high mortality. The doctors and scientists would like to argue how to enhance the validity of the rehabilitation treatment and how to further improve the level of treatment on stroke. OBJECTIVE: The aim of this study was to quantitatively analyze the current worldwide progress in research on stroke rehabilitation treatment based on Web of Science database and ClinicalTrial.gov in the past 10 years. METHODS: We conducted a quantitative analysis of clinical trial articles regarding stroke rehabilitation published in English from 2003 to 2013 and indexed in the National Institutes of Health Clinical Trials registry and Web of Science databases. Data were downloaded on March 15, 2013. RESULTS: (1) From 2003 to 2013, 2 654 clinical trials investigating stroke were indexed in ClinicalTrials.gov. There were only 58 clinical trials registered in 2003, and there was a marked increase from 2005. A total of 605 clinical trials on the rehabilitation of stroke were conducted in the past 10 years. (2) The analysis showed that most of the trials in the field were registered by North American institutions. With respect to the Asian countries, China and Taiwan area of China also published a reasonable proportion of the trials, but comparatively speaking, the number of trials is really rare. Most of the interventions were drugs, followed by the devices, and behavioral interventions were ranked third. (3) In the past 10 years, there were 4 052 studies on stroke indexed by Web of Science database. CONCLUSION: From perspective of research progress, we found that the number of clinical trials and papers on stroke rehabilitation has increased significantly in the past 10 years, between them a remarkable positive correlation exists. 相似文献
968.
969.
采用原位复合法,以纳米羟基磷灰石为增强体,以聚氨酯预聚体为基体,制备了快速成型所需的HA /PU 基质复合材料,采集个体股骨近端骨缺损部位的 CT 影像数据,利用计算机辅助医学影像 Mimics 软件进行三维重建,直接得到股骨近端的三维模型,再将三维模型信息转换成快速成型的“STL”数据文件,以此直接驱动三维打印机制造出 ABS 实体模型,然后经硅胶模具和浇注成型手段,将 HA /PU 复合预聚体基质浇注到硅胶模具中,进行固化成型,得到符合个性化需求的 HA /PU 股骨近端植入体。为克服批量生产植入体型号、尺寸与个体需求不匹配的弊端,制造高附加值人工骨产品提供实验基础和技术支持。 相似文献
970.