全文获取类型
收费全文 | 58916篇 |
免费 | 6721篇 |
国内免费 | 4040篇 |
专业分类
耳鼻咽喉 | 528篇 |
儿科学 | 688篇 |
妇产科学 | 532篇 |
基础医学 | 5378篇 |
口腔科学 | 1415篇 |
临床医学 | 7648篇 |
内科学 | 7105篇 |
皮肤病学 | 635篇 |
神经病学 | 2459篇 |
特种医学 | 2185篇 |
外国民族医学 | 22篇 |
外科学 | 5286篇 |
综合类 | 12281篇 |
现状与发展 | 21篇 |
一般理论 | 9篇 |
预防医学 | 5222篇 |
眼科学 | 1377篇 |
药学 | 7322篇 |
92篇 | |
中国医学 | 5568篇 |
肿瘤学 | 3904篇 |
出版年
2024年 | 426篇 |
2023年 | 1318篇 |
2022年 | 3354篇 |
2021年 | 4164篇 |
2020年 | 3187篇 |
2019年 | 2226篇 |
2018年 | 2271篇 |
2017年 | 2345篇 |
2016年 | 2014篇 |
2015年 | 2983篇 |
2014年 | 3567篇 |
2013年 | 3632篇 |
2012年 | 5068篇 |
2011年 | 5301篇 |
2010年 | 3729篇 |
2009年 | 3000篇 |
2008年 | 3300篇 |
2007年 | 3144篇 |
2006年 | 2834篇 |
2005年 | 2326篇 |
2004年 | 1732篇 |
2003年 | 1736篇 |
2002年 | 1469篇 |
2001年 | 1085篇 |
2000年 | 742篇 |
1999年 | 601篇 |
1998年 | 358篇 |
1997年 | 295篇 |
1996年 | 214篇 |
1995年 | 202篇 |
1994年 | 178篇 |
1993年 | 124篇 |
1992年 | 141篇 |
1991年 | 97篇 |
1990年 | 115篇 |
1989年 | 65篇 |
1988年 | 70篇 |
1987年 | 63篇 |
1986年 | 47篇 |
1985年 | 38篇 |
1984年 | 27篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1979年 | 18篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1974年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
神经肽Y(NPY)是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明,NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响(P>0.05),对巨噬细胞分泌溶菌酶有明显抑制作用(P<0.05);而对B淋巴细胞丝裂原反应性则有明显的促进作用(P<0.05)。上述结果提示,NPY对部分免疫细胞功能的影响因细胞种类而异。 相似文献
6.
7.
Genetic contributions to Parkinson's disease 总被引:8,自引:0,他引:8
Sporadic Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by the loss of midbrain dopamine neurons and Lewy body inclusions. It is thought to result from a complex interaction between multiple predisposing genes and environmental influences, although these interactions are still poorly understood. Several causative genes have been identified in different families. Mutations in two genes [α-synuclein and nuclear receptor-related 1 (Nurr1)] cause the same pathology, and a third locus on chromosome 2 also causes this pathology. Other familial PD mutations have identified genes involved in the ubiquitin–proteasome system [parkin and ubiquitin C-terminal hydroxylase L1 (UCHL1)], although such cases do not produce Lewy bodies. These studies highlight critical cellular proteins and mechanisms for dopamine neuron survival as disrupted in Parkinson's disease. Understanding the genetic variations impacting on dopamine neurons may illuminate other molecular mechanisms involved. Additional candidate genes involved in dopamine cell survival, dopamine synthesis, metabolism and function, energy supply, oxidative stress, and cellular detoxification have been indicated by transgenic animal models and/or screened in human populations with differing results. Genetic variation in genes known to produce different patterns and types of neurodegeneration that may impact on the function of dopamine neurons are also reviewed. These studies suggest that environment and genetic background are likely to have a significant influence on susceptibility to Parkinson's disease. The identification of multiple genes predisposing to Parkinson's disease will assist in determining the cellular pathway/s leading to the neurodegeneration observed in this disease. 相似文献
8.
基于临床流程功能需求的生理监测仪配置评估 总被引:1,自引:0,他引:1
病人生理监测仪是临床医学的主要仪器之一,由于所涉及的技术流程定位不同,功能需求也就不同,其功能配置也应有所不同。本文从分解分析生理监测仪相关应用领域的技术定位功能需求出发,讨论卫生技术装备管理的功能配置评估。 相似文献
9.
Mário Martins Oliveira Nogueira da Silva Ana Teresa Timóteo Joana Feliciano Lídia de Sousa Sofia Santos Fernando Marques Rui Ferreira 《Revista portuguesa de cardiologia》2007,26(7-8):691-702
Atrial electrical remodeling plays a part in recurrence of atrial fibrillation (AF). It has been related to an increase in heterogeneity of atrial refractoriness that facilitates the occurrence of multiple reentry wavelets and vulnerability to AF. AIM: To examine the relationship between dispersion of atrial refractoriness (Disp_A) and vulnerability to AF induction (A_Vuln) in patients with clinical paroxysmal AF (PAF). METHODS: Thirty-six patients (22 male; age 55+/-13 years) with > or =1 year of history of PAF (no underlying structural heart disease--n=20, systemic hypertension--n=14, mitral valve prolapse--n=1, surgically corrected pulmonary stenosis--n=1), underwent electrophysiological study (EPS) while off medication. The atrial effective refractory period (AERP) was assessed at five different sites--high (HRA) and low (LRA) lateral right atrium, high interatrial septum (IAS), proximal (pCS) and distal (dCS) coronary sinus--during a cycle length of 600 ms. AERP was taken as the longest S1-S2 interval that failed to initiate a propagation response. Disp_A was calculated as the difference between the longest and shortest AERP. A_Vuln was defined as the ability to induce AF with 1-2 extrastimuli or with incremental atrial pacing (600-300 ms) from the HRA or dCS. The EPS included analysis of focal electrical activity based on the presence of supraventricular ectopic beats (spontaneous or with provocative maneuvers). The patients were divided into group A--AF inducible (n=25) and group B--AF not inducible (n=11). Disp_A was analyzed to determine any association with A_Vuln. Disp_A and A_Vuln were also examined in those patients with documented repetitive focal activity. Logistic regression was used to determine any association of the following variables with A_Vuln: age, systemic hypertension, left ventricular hypertrophy, left atrial size, left ventricular function, duration of PAF, documented atrial flutter/tachycardia and Disp_A. RESULTS: There were no significant differences between the groups with regard to clinical characteristics and echocardiographic data. AF was inducible in 71% of the patients and noninducible in 29%. Group A had greater Disp_A compared to group B (105+/-78 ms vs. 49+/-20 ms; p=0.01). Disp_A was >40 ms in 50% of the patients without A_Vuln and in 91% of those with A_Vuln (p=0.05). Focal activity was demonstrated in 14 cases (39%), 57% of them with A_Vuln. Disp_A was 56+/-23 ms in this group and 92+/-78 ms in the others (p=0.07). Using logistic regression, the only predictor of A_Vuln was Disp_A (p=0.05). CONCLUSION: In patients with paroxysmal AF, Disp_A is a major determinant of A_Vuln. Nevertheless, the degree of nonuniformity of AERP appears to be less important as an electrophysiological substrate for AF due to focal activation. 相似文献
10.
岳培荣 《河南中医学院学报》2006,21(2):50-51
感染性发热病是细菌或病毒等病原微生物侵入人体而引起的急性热病,在临床上一般包括细菌性感染和病毒性感染.临证以发热恶寒、口苦头晕、胸腕痞闷、恶心纳呆、大便不畅或便秘、舌苔黄厚而腻、脉弦滑为主证,属湿热病邪侵入人体所引起的湿温病范畴.我院中医门诊自2000年以来,采用中医药辨证治疗湿热郁遏型感染性疾病获得了较好的疗效,现将资料完整的126例分析如下. 相似文献