全文获取类型
收费全文 | 450461篇 |
免费 | 295184篇 |
国内免费 | 45698篇 |
专业分类
耳鼻咽喉 | 4227篇 |
儿科学 | 7565篇 |
妇产科学 | 3420篇 |
基础医学 | 100912篇 |
口腔科学 | 6794篇 |
临床医学 | 82392篇 |
内科学 | 110916篇 |
皮肤病学 | 6973篇 |
神经病学 | 26622篇 |
特种医学 | 16340篇 |
外国民族医学 | 12篇 |
外科学 | 58552篇 |
综合类 | 108843篇 |
现状与发展 | 57篇 |
一般理论 | 3篇 |
预防医学 | 66982篇 |
眼科学 | 21016篇 |
药学 | 82402篇 |
304篇 | |
中国医学 | 62834篇 |
肿瘤学 | 24177篇 |
出版年
2023年 | 4911篇 |
2022年 | 10034篇 |
2021年 | 11898篇 |
2020年 | 13269篇 |
2019年 | 16096篇 |
2018年 | 16803篇 |
2017年 | 18950篇 |
2016年 | 16256篇 |
2015年 | 20008篇 |
2014年 | 22814篇 |
2013年 | 24929篇 |
2012年 | 31170篇 |
2011年 | 33913篇 |
2010年 | 35099篇 |
2009年 | 40812篇 |
2008年 | 28964篇 |
2007年 | 24728篇 |
2006年 | 22550篇 |
2005年 | 19427篇 |
2004年 | 17995篇 |
2003年 | 15617篇 |
2002年 | 14437篇 |
2001年 | 16084篇 |
2000年 | 10400篇 |
1999年 | 13453篇 |
1998年 | 13995篇 |
1997年 | 13879篇 |
1996年 | 14965篇 |
1995年 | 15133篇 |
1994年 | 14885篇 |
1993年 | 13580篇 |
1992年 | 12801篇 |
1991年 | 12177篇 |
1990年 | 11138篇 |
1989年 | 10990篇 |
1988年 | 10531篇 |
1987年 | 9887篇 |
1986年 | 9390篇 |
1985年 | 8462篇 |
1984年 | 6535篇 |
1983年 | 6552篇 |
1982年 | 7608篇 |
1981年 | 7145篇 |
1980年 | 6810篇 |
1979年 | 6644篇 |
1978年 | 5818篇 |
1977年 | 6123篇 |
1976年 | 5745篇 |
1975年 | 5486篇 |
1974年 | 5034篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition. 相似文献
92.
经皮椎弓根技术治疗胸腰椎骨折的临床探讨 总被引:2,自引:0,他引:2
目的:探讨微创经皮椎弓根螺钉内固定手术治疗胸腰椎骨折的可行性及其疗效。方法:20例胸腰椎骨折病例,男13例,女7例;年龄28~65岁,平均48·2岁。其中16例损伤平面以下无神经功能损害、无双下肢和大小便障碍;4例有不同程度的脊髓损伤,按Frankel分级:C级1例,D级3例。在C形臂X线的定位下确定需要固定的椎弓根根部,做4个1·5cm长的切口,固定与复位均在4个小切口内完成。结果:所有病例均获随访,时间9~18个月,平均15个月。术后患者椎体高度均有不同程度恢复,椎体后凸畸形获得不同程度矫正。手术时间约1·5h,出血量约80ml。结论:微创经皮椎弓根螺钉内固定手术操作简便、安全可靠,具有创伤小、出血少、疼痛轻、恢复快、住院时间短等优点。 相似文献
93.
94.
95.
96.
【目的】比较不同区域猪晶状体上皮细胞的基因表达在转录组水平上的差异。【方法】解剖显微镜下分离晶状体前囊膜,将附着于其上的上皮细胞分为中央(直径为10.56mm)和周边两部分。分别提取两个样本的总RNAs并经PCR扩增,以Cy3和Cy5分别标记扩增的中央与周边部分的cDNA。与含7548个基因的表达谱芯片杂交,经图像分析,生物信息学处理获得基因表达在转录水平差异的相关信息。【结果】中央与周边区域的猪晶状体上皮细胞在转录组水平共鉴定出952个有效表达的基因点,其中差异表达基因261个.以中央区域为参照,周边上皮细胞mRNA上调137个,下调124个。差异表达基因主要涉及的功能有:细胞周期与凋亡、细胞骨架蛋白及细胞外基质、转录、细胞信号分子等。【结论】中央与周边区域猪晶状体上皮细胞基因表达在转录组水平上差异明显。这类差异呈明显的功能聚类。 相似文献
97.
人胚雪旺细胞组织工程神经修复坐骨神经缺损的实验研究 总被引:1,自引:0,他引:1
目的:探索人胚雪旺细胞作为组织工程的种子细胞修复周围神经缺损的可行性。方法:通过组织工程方法用PLGA导管和polyglactin 910纤维负载人胚雪旺细胞预先构置好人工神经,然后用于修复大鼠20mm的坐骨神经缺损,并与神经切断后原位缝合以及用单纯的PLGA导管进行修复的实验组进行对照。通过活体肢体功能观察、靶器官肌肉测量、电生理检测、辣根过氧化物酶示踪、连续组织切片图像分析以及透射电镜等检查神经再生情况。结果:人工神经修复组神经再生良好,效果接近于神经原位缝合组,明显优于单纯的PLGA导管修复组。结论:人胚雪旺细胞构建的人工神经可以修复20mm的周围神经缺损。 相似文献
98.
Abstract It is well established that thrombolytic therapy increases the risk of secondary intracerebral hemorrhage in ischemic stroke
patients. However, the term “intracerebral hemorrhage” (ICH) covers a wide spectrum from tiny spots of blood to massive space-occupying
hematoma. We will review the etiology and clinical consequences of secondary hemorrhage after thrombolysis in ischemic stroke
patients and discuss the ability of magnetic resonance imaging (MRI) to predict this phenomenon. MRI is a highly sensitive
tool for detection of hemorrhagic transformation after ischemic stroke. The definitions of a so-called symptomatic hemorrhage
after ischemic infarction differ considerably and will also be described. Attributing a causal relationship of a clinical
deterioration to a secondary hemorrhage is not easy and should be only addressed when it exceeds at least 30% of the infarct
volume. In other patients, secondary hemorrhage might be regarded as side effect of reperfusion within the region with the
most severe perfusion deficit. Cerebral microbleeds (CMBs) are a frequent finding in patients with leukoaraiosis and appear
to be a general marker of various types of bleeding- prone small vessel disease and a predictor of recurrent vascular events.
Current data do not support the hypothesis that the detection of CMBs is a useful diagnostic criterion for the exclusion of
patients with CMBs from thrombolytic therapy. However, an increased risk for the rare patients with numerous CMBs can not
be ruled out.
相似文献
99.
Access to good-quality health services is crucial for the improvement of many health outcomes, such as those targeted by the
Millennium Development Goals (MDGs) adopted by the international community in 2000. The health-related MDGs cannot be achieved
if vulnerable populations do not have access to skilled personnel and to other necessary inputs. This paper focuses on the
geographical dimension of access and on one of its critical determinants: the availability of qualified personnel. The objective
of this paper is to offer a better understanding of the determinants of geographical imbalances in the distribution of health
personnel, and to identify and assess the strategies developed to correct them. It reviews the recent literature on determinants,
barriers and the effects of strategies that attempted to correct geographical imbalances, with a focus on empirical studies
from developing and developed countries. An analysis of determinants of success and failures of strategies implemented, and
a summary of lessons learnt, is included. 相似文献
100.
L. Dvorakova J. Sikora M. Hrebicek H. Hulkova M. Bouckova L. Stolnaja M. Elleder 《Journal of inherited metabolic disease》2006,29(4):591
Summary We present the third case of Niemann–Pick disease type C without neurological symptoms. The patient was a 53-year-old woman
without significant prior health problems who died of acute pulmonary embolism. Autopsy findings of hepatosplenomegaly, lymphadenopathy
and ceroid-rich foam cells raised the suspicion of the visceral form of acid sphingomyelinase deficiency (Niemann–Pick disease
type B; NPB) or a much rarer disorder, variant adult visceral form of Niemann–Pick disease type C (NPC). To verify the histopathological
findings, SMPD1, NPC1 and NPC2 genes were analysed. Two novel sequence variants, c.1997G>A (S666N) and c.2882A>G (N961S) were detected in the NPC1 gene. No pathogenic sequence variants were found either in the SMPD1 gene mutated in NPB or in NPC2 gene. The pathogenicity of both NPC1 variants was supported by their location in regions important for the protein function. Both variations were not found in
more than 300 control alleles. Identified sequence variations confirm the diagnosis of the extremely rare adult visceral form
of Niemann–Pick disease type C, which is otherwise dominated by neurovisceral symptoms. Although only three patients have
been reported, this (most probably underdiagnosed) form of NPC should be considered in differential diagnosis of isolated
hepatosplenomegaly with foam cells in adulthood.
Electronic supplementary material Supplementary material is available for this article at 相似文献