全文获取类型
收费全文 | 11480篇 |
免费 | 806篇 |
国内免费 | 268篇 |
专业分类
耳鼻咽喉 | 159篇 |
儿科学 | 477篇 |
妇产科学 | 312篇 |
基础医学 | 1166篇 |
口腔科学 | 254篇 |
临床医学 | 1071篇 |
内科学 | 1908篇 |
皮肤病学 | 399篇 |
神经病学 | 485篇 |
特种医学 | 370篇 |
外科学 | 1759篇 |
综合类 | 987篇 |
现状与发展 | 2篇 |
一般理论 | 6篇 |
预防医学 | 812篇 |
眼科学 | 495篇 |
药学 | 851篇 |
2篇 | |
中国医学 | 291篇 |
肿瘤学 | 748篇 |
出版年
2023年 | 126篇 |
2022年 | 342篇 |
2021年 | 497篇 |
2020年 | 344篇 |
2019年 | 336篇 |
2018年 | 369篇 |
2017年 | 310篇 |
2016年 | 372篇 |
2015年 | 445篇 |
2014年 | 530篇 |
2013年 | 630篇 |
2012年 | 828篇 |
2011年 | 817篇 |
2010年 | 554篇 |
2009年 | 501篇 |
2008年 | 612篇 |
2007年 | 635篇 |
2006年 | 563篇 |
2005年 | 492篇 |
2004年 | 443篇 |
2003年 | 374篇 |
2002年 | 357篇 |
2001年 | 201篇 |
2000年 | 180篇 |
1999年 | 126篇 |
1998年 | 88篇 |
1997年 | 48篇 |
1996年 | 48篇 |
1995年 | 51篇 |
1994年 | 47篇 |
1993年 | 29篇 |
1992年 | 71篇 |
1991年 | 76篇 |
1990年 | 71篇 |
1989年 | 50篇 |
1988年 | 60篇 |
1987年 | 46篇 |
1986年 | 44篇 |
1985年 | 55篇 |
1984年 | 42篇 |
1983年 | 39篇 |
1979年 | 33篇 |
1977年 | 28篇 |
1974年 | 39篇 |
1973年 | 28篇 |
1972年 | 34篇 |
1971年 | 30篇 |
1970年 | 38篇 |
1969年 | 33篇 |
1968年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Kui Li Jiawen Wang Shengxiong Liu Sen Su Chenjian Feng Xiaoxiang Fan Zhiyong Yin 《中华创伤杂志(英文版)》2015,18(2):65-73
Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases.
Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks.
Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values.
Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism. 相似文献
2.
Janette B Gomos Theresa M Rowe Saumendra N Sarkar Sean P Kessler Ganes C Sen 《Journal of interferon & cytokine research》2002,22(2):199-206
The 9-2 isozyme of 2-5 (A) synthetase has cellular proapoptotic functions that are mediated not by enzyme activity but by the Bcl-2 homology domain 3 present in its unique carboxyl-terminal region. Another proapoptotic cellular protein is Bax, whose absence in the Bax(-/-) mice causes male sterility due to abnormal sperm differentiation. In this study, we examined whether transgenic 9-2 expression can substitute for the in vivo reproductive function of Bax. To achieve this goal, a sperm-specific promoter was used to drive the expression of 9-2 in the sperm of transgenic mice. By selective cross-breeding, the transgene was transferred to Bax(-/-) mice to generate the experimental mouse line (Bax(-/-), 9-2(+/+)). The male experimental mice were sterile, and their testes maintained the structural abnormality found in Bax(-/-) mice. Thus, the male reproduction functions of Bax could not be replaced by the 9-2 isozyme of 2-5 (A) synthetase. 相似文献
3.
Ramesh R Boinpally Sen Lin Zhou Srinivasu Poondru Gopinath Devraj Bhaskara R Jasti 《European journal of pharmaceutics and biopharmaceutics》2003,56(3):389-392
Skin penetration of topically applied diclofenac is important for the treatment of rheumatic diseases and actinic keratoses. We have studied the permeation of diclofenac across human cadaver epidermis in-vitro from four lecithin vesicle formulations and a few marketed semi-solid preparations. The lecithin vesicle formulations were prepared by dissolving the lipid contents (lecithin and sodium cholate) in a 1:1 mixture of methanol-chloroform, evaporating the solvents under vacuum, and hydrating the lipid layer with the drug solution in water or 10% ethanol. The vesicles were sonicated for 5 min to reduce the vesicle size and their size and Zeta potential were characterized. The cumulative amount and maximum flux of diclofenac was 69.7+/-40.3 micrograms and 4.77+/-3.16 micrograms/hcm(2) from lecithin vesicles containing sodium cholate and 10% ethanol, and is the highest of all formulations studied. The cumulative amount and mean maximum flux obtained from other formulations were in the range of 2.46+/-1.98-29.9+/-10.1 micrograms and 0.53+/-0.46-3.61+/-0.86 micrograms/hcm(2). Based on the results, lecithin vesicles of diclofenac appear to be advantageous for the topical delivery of diclofenac. 相似文献
4.
CD14+单核细胞人类白细胞抗原DR表达率与脓毒症关系的研究 总被引:15,自引:0,他引:15
目的了解烧伤延迟复苏时CDl4^+单核细胞人类白细胞抗原DR(HLA—DR)表达率的变化,分析其与脓毒症的关系。方法选择烧伤面积大于30%TBSA的25例烧伤延迟复苏患者,于伤后1、3、7、14、28d取外周血,其中7例患者住院期间并发脓毒症,于脓毒症发生后连续2d亦取其外周血。另取20例健康体检者外周血作为对照。流式细胞仪检测CD14^+单核细胞HLA.DR表达率,酶联免疫吸附测定法检测血浆中肿瘤坏死因子α(TNF—α)、白细胞介素10(IL-10)的浓度。结果非脓毒症患者伤后1、3、7、14、28dCD14^+单核细胞HLA—DR表达率分别为(15±6)%、(74±5)%、(264±17)%、(284-16)%、(474-16)%,明显低于健康体检者[(924±10)%,P〈0.01];脓毒症患者发生脓毒症后1、2d,该指标亦明显低于健康体检者及非脓毒症患者伤后1、7、14、28d(P〈0.01)。脓毒症患者TNF—d检出率及TNF—α、IL-10浓度,均高于非脓毒症患者和健康体检者(P〈0.05或P〈0.01)。伤后1、7、28d,外周血CD14^+单核细胞HLA—DR表达率与IL—10浓度呈显著负相关(r分别为-0.9963、-0.7459、-0.8474,P〈0.01)。结论烧伤延迟复苏患者免疫功能低下,促炎性介质释放量增加,并发脓毒症时则更为严重。外周血CD14^+单核细胞HLA—DR表达率可作为动态检测患者免疫功能状态的有效指标。 相似文献
5.
The present study reveals our experience in the medical management of 30 cases of progressive/malignant exophthalmos, employing costicosteroid, b-blocker, diuretic and a preparation containing proteolytic enzymes. There was encouraging improvement in terms of symptoms, proptosis and optic nerve compression, while reduction of ophthalmoplegia was not so satisfactory. However, none of the patients needed decompression surgery. 相似文献
6.
7.
595 nm可调脉冲染料激光治疗皮肤血管异常性疾病疗效分析 总被引:1,自引:0,他引:1
目的观察595nm可调脉冲染料激光治疗皮肤血管异常性疾病(血管畸形与血管瘤)的临床疗效。方法应用595nm可调脉冲染料激光治疗396例皮肤血管异常性疾病,观察临床疗效。结果毛细血管扩张和蜘蛛痣疗效最好,有效率为100%,其次是草莓状血管瘤,有效率为92.4%,鲜红斑痣为82.8%。面积越小,年龄越小,疗效越好(P<0.05);性别与疗效无明显差异。术中疼痛较轻,术后副作用少。结论595nm可调脉冲染料激光治疗皮肤血管异常性疾病安全性高,疗效确切。 相似文献
8.
Karyotypes of 36 lymphoblastoid cell lines established by Epstein-Barr virus (EBV) transformation of peripheral blood lymphocytes (PBL) of eight normal individuals and 28 patients with various nonhematologic malignancies were analyzed. In seven lines (19.4%), cells with trisomy 12 were noted, with clonality in two of these lines. In two of 11 metaphases with such trisomy, chromosome 12 was involved in structural rearrangements [t(8;12)(q12;p12) and t(12;12)(q11;q24)]. No cells with trisomy 12 were observed in phytohemagglutinin (PHA)-stimulated PBL cultures of these individuals. In 250 individuals (normal and with nonhematologic malignancies) examined in our laboratory in the last 5 years, extra copies of chromosome 12 in PHA-stimulated PBL cultures were observed in only five of 23,216 cells (0.02%). There were no cases of clonality in these samples. The frequency of an extra chromosome 12 was comparable to that of the other chromosomes except 21 and X, whose frequency of occurrence was 0.08% and 0.09%, respectively. These findings should be considered random events in PHA-stimulated PBL. On the contrary, in lymphoblastoid cell lines established by EBV transformation, trisomy of chromosome 12 was the most frequent numerical abnormality. It was observed in 64.7% of all cases with chromosome gains and therefore could not be considered a random occurrence. The specificity of this phenomenon for EBV transformation is supported by the results of cytogenetic analysis of eight lymphoblastoid cell lines established by an alternative procedure in our laboratory [1]. In 400 cells analyzed not a single cell with trisomy 12 was observed. We suggest that EBV transformation might either randomly induce formation of such cells in immortalized B-cell populations or show potentially blastomogenic cells or proneness to their formation in certain individuals who could be predisposed to develop lymphoproliferative diseases, especially chronic lymphocytic leukemia (CLL) in which trisomy of chromosome 12 is the most common alteration. 相似文献
9.
10.
Spatial analysis of (90)Sr artificial radionuclide in consequence of global fallout and Chernobyl nuclear accident has been carried out by using the point cumulative semivariogram (PCSV) technique based on 40 surface water station measurements in Keban Dam Lake during March, April, and May 2006. This technique is a convenient tool in obtaining the regional variability features around each sampling point, which yields the structural effects also in the vicinity of the same point. It presents the regional effect of all the other sites within the study area on the site concerned. In order to see to change of (90)Sr, the five models are constituted. Additionally, it provides a measure of cumulative similarity of the regional variable, (90)Sr, around any measurement site and hence it is possible to draw regional similarity maps at any desired distance around each station. In this paper, such similarity maps are also drawn for a set of distances. (90)Sr activities in lake that distance approximately 4.5 km from stations show the maximum similarity. 相似文献