全文获取类型
收费全文 | 477篇 |
免费 | 41篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 43篇 |
妇产科学 | 13篇 |
基础医学 | 60篇 |
口腔科学 | 11篇 |
临床医学 | 48篇 |
内科学 | 102篇 |
皮肤病学 | 28篇 |
神经病学 | 17篇 |
特种医学 | 83篇 |
外科学 | 36篇 |
综合类 | 21篇 |
预防医学 | 9篇 |
眼科学 | 7篇 |
药学 | 21篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 24篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 23篇 |
2009年 | 26篇 |
2008年 | 15篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 14篇 |
2004年 | 7篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 4篇 |
1999年 | 6篇 |
1998年 | 20篇 |
1997年 | 42篇 |
1996年 | 30篇 |
1995年 | 20篇 |
1994年 | 23篇 |
1993年 | 21篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 26篇 |
1988年 | 13篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1963年 | 1篇 |
1956年 | 1篇 |
1955年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有518条查询结果,搜索用时 31 毫秒
101.
采用RITQ综合评定婴儿气质的报告 总被引:2,自引:0,他引:2
张琪 《中国心理卫生杂志》1997,11(3):155-157
采用Carey的RITQ为4-8个月婴儿气质的测查工具,结合专人问卷与观察,对400名婴儿的气质进行了综合评定,结果表明:九个气质因子的重测信度为0.77-0.90,多数气质因子间存在着显著的相关,相关系数为0.10-0.59。大、小婴儿活动水平、接近-退缩、适应及反应强度四个气质因子存在差异。气质类型与国外同龄婴儿及国内学前儿童的分布相接近。提示采用RITQ综合评定婴儿气质的信度和效度较好,可用于我国婴儿的气质测查及研究。 相似文献
102.
围术期焦虑及干预 总被引:31,自引:0,他引:31
胜利 《中国心理卫生杂志》1997,11(3):134-138
本文以自评、医师评定两种方式对腹部手术患者103例(除外精神科病史)进行围术期焦虑及干预的描述性研究。发现术前明显焦虑者占30%,疑有焦虑者占34%,无焦虑者占36%。特质焦虑直接影响术前状态焦虑,疾病、手术因素影响术后焦虑,此时特质焦虑仍起作用。支持性心理治疗能降低术前焦虑,提高无并发症者满意程度,但对躯体预后无直接影响。另外,腹部手术患者入院时血皮质醇浓度高于正常人群。 相似文献
103.
104.
Effects of interleukin-2 on gene expression in human neutrophils 总被引:1,自引:1,他引:1
Recently, the interleukin-2 receptor (IL-2R) was shown to be present on human neutrophils, and IL-2-neutrophil interactions are believed to be important in both tumor rejection and increased susceptibility to bacterial infections. Furthermore, neutrophils have been shown to synthesize host defense proteins, such as cytokines. In this study, we analyzed the effects of IL-2 on the induction of de novo RNA and protein synthesis in this cell type. When cells were stimulated with IL- 2 alone, the level of incorporation of either [5-3H]-uridine or [35S]- methionine and [35S]-cysteine was similar to unstimulated cells. However, when cells were stimulated with the combination of a fixed concentration of granulocyte-macrophage colony-stimulating factor (GM- CSF), a dose-dependent effect of IL-2 was observed on the induction of both RNA and protein synthesis. In the presence of tumor necrosis factor-alpha or formyl-methionyl-leucyl-phenylalanine, however, IL-2 exerted no similar effect. Furthermore, the study of a large number of normal subjects (n = 55) showed reproducible categories of responders (low, intermediate, and high). The binding of IL-2 to the IL-2R complex on human neutrophils increased on GM-CSF-stimulated neutrophils compared with unstimulated cells. However, no increase in the level of expression of either the alpha or beta chains of this receptor complex was observed. This finding suggests that GM-CSF functionally activates the IL-2R, but does not regulate its level of expression. Finally, we found that human neutrophils constitutively express IL-2R gamma chain mRNA and thus have the potential to express the functional IL-2R complex. Our findings on IL-2-neutrophil interactions should lead to new avenues of research in understanding the responses of patients undergoing GM-CSF or IL-2 therapy. 相似文献
105.
GC Akuodor AD Essien E David-Oku KC Chilaka JL Akpan B Ezeokpo JOC Ezeonwumelu 《Asian Pacific journal of tropical medicine》2013,6(10):771-775
ObjectiveTo evaluate the effect of aqueous leaf extract of Guiera senegalensis (G. senegalensis) on gastric mucosal damage using different ulcer models.MethodsConsidering the above claims, the present study was undertaken to validate the gastroprotective potential of the aqueous leaf extract of this plant against ethanol, water immersion and Aspirin induced ulcer models.ResultsThe leaf extract (50, 100 and 200 mg/kg, p.o.) significantly (P<0.05) decreased the ulcer index in all assays used.ConclusionsThe results obtained, provide strong evidence of antiulcer activity of the leaf extract of G. senegalensis and support the traditional uses of the plant for the treatment of ulcer. 相似文献
106.
造血微环境决定脐血造血干/祖细胞的早期分裂行为 总被引:3,自引:0,他引:3
目的 在特定生长因子的培养体系中,观察模拟造血微环境及粘附因素对人类脐血造血干/祖细胞早期分裂行为影响。方法 (1)应用流式细胞仪(FACS)分选CD34^ CD38^-细胞;(2)细胞培养体系中应用干细胞支持性基质AFT024及单一粘附因素纤维结合素(Fn)。并观察其对细胞早期分裂行为的影响。结果 (1)在联合生长因子的条件下,人类脐血CD34^ CD38^-细胞早期分裂呈现固定比例的静止,慢分裂,快分裂以及不对称分裂状态;(2)未观察到单一粘附因子Fn对其早期分裂行为的影响;(3)干细胞支持性基质AFT024所模拟的体外造血微环境可促使脐血造血干/祖细胞广泛增殖并更多地进行不对称分裂。结论 (1)CD34^ CD38^-细胞群体具有异质性。由具有不同增殖行为的亚群组成,在体外培养早期存在不对称分裂;(2)体外模拟的骨髓微环境AFT024基质滋养层较细胞因子及单一粘附因素能够更好地支持造血干/祖细胞的增殖并保持其自我更新的特性。 相似文献
107.
Thrombolytic therapy with tissue plasminogen activator or streptokinase induces transient thrombin activity 总被引:7,自引:0,他引:7
We have determined the plasma level of fibrinopeptide A as a specific index of thrombin activity during the infusion of a thrombolytic agent in patients with acute myocardial infarction. Peripheral venous plasma levels of fibrinopeptide A increased following the initiation of thrombolytic therapy from 2.7 nmol/L to a peak of 13.0 nmol/L at 30 minutes with streptokinase and from 1.1 nmol/L to a peak of 10.7 nmol/L at 90 minutes with tissue plasminogen activator. The amount of fibrinogen converted to fibrin I was determined by integration of the plasma level of fibrinopeptide A over time. The amount of fibrin I formed over the five-hour period from the start of drug infusion was approximately 10 mg/dL in response to either streptokinase or recombinant tissue plasminogen activator. We conclude that activation of coagulation occurs in response to thrombolytic therapy despite heparin administration. This thrombin action, though transient, would be sufficient to cause rethrombosis if localized and incompletely opposed by fibrinolytic activity. 相似文献
108.
Dimovski AJ; Divoky V; Adekile AD; Baysal E; Wilson JB; Prior JF; Raven JL; Huisman TH 《Blood》1994,83(3):822-827
A novel deletion of approximately 27 kb with the 5' breakpoint 1.5 to 2.2 kb upstream of the beta-globin gene, and the 3' breakpoint approximately 24 kb downstream of the beta-globin gene, has been found in five members of two families from Southeast Asia (Vietnam and Cambodia). Six members of another family from China, previously reported from our laboratory, have also been shown to carry this deletion. The patients presented with mild hypochromia and microcytosis, a hemoglobin (Hb) A2 level of approximately 4.0%, and a markedly increased, heterocellularly distributed, Hb F level (14.0 to 26.0%). In vitro globin-chain synthesis showed a mild imbalance with appreciable gamma-chain compensation (alpha/beta + gamma ratio of 1.46). The 3' end of this deletion includes the 3'HS-1, and we hypothesize that removal of this region results in the loss of its gamma-globin gene-silencing effect, which causes a markedly elevated Hb F level with a modest increase in Hb A2 levels, unlike the situation in other deletional beta zero-thalassemias. The possible influence of particular sequence variations in the locus control region 5'HS-2 and the G gamma promoter, present on the chromosome with this deletion, on the overall gamma-globin gene should also be considered. 相似文献
109.
The mechanism by which papain detaches IgG-sensitized erythrocytes from the monocyte surface has been explored in an in vitro assay for the monocyte IgG receptor using red cells quantitatively sensitized with IgG anti-Rh D immunoglobulin. Papain treatment of IgG-sensitized erythrocytes diminished the ability of these cells to bind to the monocyte surface; however, treatment of erythrocytes with papain prior to sensitization with IgG did not inhibit binding, and at papain concentrations is greater than or equal to 38 mug/ml binding was enhanced. IgG receptor activity was not diminished by prior treatment of monolayer cells with papain and was enhanced with high concentrations of papain. These studies suggest that papain detaches erythrocytes from the monocyte surface by virtue of its proteolytic effect on IgG and not by an effect of papain on the D antigen of red cells or the IgG receptor on monocytes. 相似文献
110.
C Antoniou† MG Kosmadaki† AJ Stratigos AD Katsambas 《Journal of the European Academy of Dermatology and Venereology》2008,22(9):1110-1119
The popularity of sunscreens dramatically increased since ultraviolet irradiation was implicated in the pathogenesis of skin cancer and skin ageing. The absorption properties, safety, photostability of different organic and inorganic filters are reviewed: para -aminobenzoic acid, salicylates, cinnamates, benzophenones, butylmethoxydibenzoylmethane (Parsol 1789), drometrizole trisulphonic (Mexoryl XL), terephthalydene dicamphor sulphonic acid (Mexoryl SX), methylene bisbenzotriazol tetramethylbutylphenol (Tinasorb M), anisotriazine (Tinasorb S), titanium dioxide and zinc oxide. Furthermore, this review discusses the optimal methods for measuring the protection that a sunscreen offers, the role of sunscreen use in melanoma prevention and future trends in sunscreen filters development. 相似文献