全文获取类型
收费全文 | 886605篇 |
免费 | 74132篇 |
国内免费 | 3683篇 |
专业分类
耳鼻咽喉 | 12960篇 |
儿科学 | 24956篇 |
妇产科学 | 25456篇 |
基础医学 | 127270篇 |
口腔科学 | 25943篇 |
临床医学 | 78828篇 |
内科学 | 168628篇 |
皮肤病学 | 17192篇 |
神经病学 | 71541篇 |
特种医学 | 36029篇 |
外国民族医学 | 192篇 |
外科学 | 138708篇 |
综合类 | 28681篇 |
现状与发展 | 7篇 |
一般理论 | 264篇 |
预防医学 | 68808篇 |
眼科学 | 21145篇 |
药学 | 67341篇 |
23篇 | |
中国医学 | 2994篇 |
肿瘤学 | 47454篇 |
出版年
2018年 | 8307篇 |
2015年 | 8953篇 |
2014年 | 12556篇 |
2013年 | 18084篇 |
2012年 | 24614篇 |
2011年 | 25935篇 |
2010年 | 15077篇 |
2009年 | 14013篇 |
2008年 | 23891篇 |
2007年 | 25846篇 |
2006年 | 25721篇 |
2005年 | 25359篇 |
2004年 | 24557篇 |
2003年 | 23521篇 |
2002年 | 22587篇 |
2001年 | 36316篇 |
2000年 | 37002篇 |
1999年 | 31532篇 |
1998年 | 9616篇 |
1997年 | 8939篇 |
1996年 | 8771篇 |
1995年 | 8272篇 |
1994年 | 7915篇 |
1992年 | 26858篇 |
1991年 | 26262篇 |
1990年 | 25757篇 |
1989年 | 24817篇 |
1988年 | 23338篇 |
1987年 | 22990篇 |
1986年 | 21830篇 |
1985年 | 21187篇 |
1984年 | 16423篇 |
1983年 | 14025篇 |
1982年 | 8872篇 |
1981年 | 8217篇 |
1980年 | 7685篇 |
1979年 | 16751篇 |
1978年 | 12123篇 |
1977年 | 10186篇 |
1976年 | 9334篇 |
1975年 | 10153篇 |
1974年 | 12647篇 |
1973年 | 12137篇 |
1972年 | 11540篇 |
1971年 | 10693篇 |
1970年 | 10227篇 |
1969年 | 9913篇 |
1968年 | 8908篇 |
1967年 | 8230篇 |
1966年 | 7658篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
71.
72.
73.
Yi Li Ying Chen Xiang Li Jian Wu Jing-Ying Pan Ri-Xin Cai Ri-Yun Yang Xiao-Dong Wang 《中国神经再生研究》2019,(9)
In the search for a therapeutic schedule for spinal cord injury, it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process. However, ad hoc selection and analysis of one or two genes cannot fully reveal the complex molecular biological mechanisms of spinal cord injury. The emergence of second-generation sequencing technology(RNA sequencing) has provided a better method. In this study, RNA sequencing technology was used to analyze differentially expressed genes at different time points after spinal cord injury in rat models established by contusion of the eighth thoracic segment. The numbers of genes that changed significantly were 944, 1362 and 1421 at 1, 4 and 7 days after spinal cord injury respectively. After gene ontology analysis and temporal expression analysis of the differentially expressed genes, C5ar1, Socs3 and CCL6 genes were then selected and identified by real-time polymerase chain reaction and western blot assay. The mRNA expression trends of C5ar1, Socs3 and CCL6 genes were consistent with the RNA sequencing results. Further verification and analysis of C5ar1 indicate that the level of protein expression of C5ar1 was consistent with its nucleic acid level after spinal cord injury. C5ar1 was mainly expressed in neurons and astrocytes. Finally, the gene Itgb2,which may be related to C5ar1, was found by Chilibot database and literature search. Immunofluorescence histochemical results showed that the expression of Itgb2 was highly consistent with that of C5ar1. Itgb2 was expressed in astrocytes. RNA sequencing technology can screen differentially expressed genes at different time points after spinal cord injury. Through analysis and verification, genes strongly associated with spinal cord injury can be screened. This can provide experimental data for further determining the molecular mechanism of spinal cord injury, and also provide possible targets for the treatment of spinal cord injury. This study was approved ethically by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2018-0306-001) on March 6, 2018. 相似文献
74.
W. Do T. Elzerman R. de Bree A. Rosenberg T. Forouzanfar E.M. Van Cann 《International journal of oral and maxillofacial surgery》2021,50(5):591-597
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. 相似文献
75.
76.
77.
Erik de Bakker Mirthe A. M. van der Putten Martijn W. Heymans Sander W. Spiekstra Taco Waaijman Liselotte Butzelaar Vera L. Negenborn Vivian K. Beekman Erman O. Akpinar Thomas Rustemeyer Frank B. Niessen Susan Gibbs 《Experimental dermatology》2021,30(1):169-178
Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R2: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice. 相似文献
78.
79.
80.