全文获取类型
收费全文 | 672篇 |
免费 | 57篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 10篇 |
妇产科学 | 3篇 |
基础医学 | 71篇 |
口腔科学 | 19篇 |
临床医学 | 106篇 |
内科学 | 63篇 |
皮肤病学 | 16篇 |
神经病学 | 14篇 |
特种医学 | 15篇 |
外科学 | 50篇 |
综合类 | 129篇 |
预防医学 | 102篇 |
眼科学 | 5篇 |
药学 | 62篇 |
中国医学 | 38篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 25篇 |
2014年 | 49篇 |
2013年 | 64篇 |
2012年 | 58篇 |
2011年 | 77篇 |
2010年 | 40篇 |
2009年 | 47篇 |
2008年 | 59篇 |
2007年 | 69篇 |
2006年 | 32篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 18篇 |
1999年 | 11篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1995年 | 5篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有747条查询结果,搜索用时 15 毫秒
1.
包含颈外静脉的颈阔肌肌皮瓣修复口腔癌切除后缺损 总被引:1,自引:0,他引:1
目的探讨将颈外静脉包含在颈阔肌肌皮瓣内修复口腔癌切除后缺损的手术方法。方法先形成蒂在颌缘下包含颈外静脉的颈阔肌肌皮瓣,待口腔肿瘤切除后,将肌皮瓣经口底隧道引入口腔修复缺损。结果临床应用17例,肌皮瓣均无血运障碍,100%存活,其中有2例发生口面痿,经换药后痿口完全闭合。结论将颈外静脉包含在颈阔肌肌皮瓣内有助于肌皮瓣血循环的改善和存活率的提高。 相似文献
2.
目的:探讨莱菔硫烷(sulforaphane,SFN)对氧化低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)诱导血小板活化的影响及其可能的分子机制。方法:在体外实验中,将健康人纯化血小板与不同浓度的SFN(1.0、2.5、5.0μmol/L)共同孵育40 min,然后用ox-LDL激活血小板20 min,并检测血小板活化的指标,包括CD62P的表达、胞内血小板因子4(platelet factor4,PF4)和趋化因子配体5(chemokine ligand 5,CCL5)的释放水平。机制上,用Western blot蛋白免疫印迹法检测血小板肉瘤酪氨酸激酶(sarcoma tyrosine kinase,Src)及其下游的脾酪氨酸激酶(spleen tyrosine kinase,Syk)磷酸化水平;用活性氧(reactive oxygen species,ROS)检测试剂盒测定胞内总ROS水平。结果:ox-LDL诱导的血小板CD62P的表达以及PF4和CCL5的释放水平均可被SFN显著抑制(P <0.05);SFN显著下调ox-LD... 相似文献
3.
Inhibition of CD4+ T lymphocyte binding to fibronectin and immune-cell accumulation in inflammatory sites by non-peptidic mimetics of Arg-Gly-Asp.
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R Hershkoviz N Greenspoon Y A Mekori R Hadari R Alon G Kapustina O Lider 《Clinical and experimental immunology》1994,95(2):270-276
The Arg-Gly-Asp (RGD) cell adhesion motif has been demonstrated in various studies to play a pivotal role in leucocyte and platelet interactions with plasma and extracellular matrix (ECM) glycoproteins. The recognition of the RGD sequence is mediated by heterodimeric receptors designated integrins of the beta 1 subfamily, expressed on distinct cell types, including T lymphocytes. We have recently shown that flexible non-peptidic mimetics of RGD, in which the two ionic side groups were separated by a linear spacer of 11 atoms, bound specifically to the platelet integrin alpha 11b beta 3, and inhibited T cell-mediated immune responses. The present study was designed to (i) further characterize the structural requirements for RGD interactions with CD4+ T cells, and (ii) examine the mechanisms by which the RGD mimetics interfere with immune cell reactivity in vivo. We now report that freezing the conformational degrees of freedom in the spacer chain, which fixes the relative orientation of the guanidinium and carboxylate side groups in a favourable manner, results in a higher level of inhibition of T cell binding to immobilized fibronectin, an RGD-containing ECM glycoprotein. In vivo, treatment of mice with relatively low doses of the RGD mimetics, but not the RGD peptide, inhibited the elicitation of an adoptively transferred DTH reaction. This inhibition was achieved by direct impairment of the ability of antigen-primed lymph node cells to migrate and accumulate in inflammatory sites. Hence, we suggest that the design and production of non-peptidic mimetics of RGD offers a novel approach to study defined parameters related to the structure-function requirements of small adhesion epitopes. Furthermore, this approach could be used therapeutically to inhibit pathological processes which depend on RGD recognition. 相似文献
4.
目的:对耳大神经及腮腺筋膜解剖进行再认识,由此改良腮腺切除手术方法。方法:解剖成人尸体10侧,术中活体解剖20侧,对耳大神经和腮腺筋膜的解剖要素进行观察。根据观察结果进行改良腮腺切除术14例,即在腮腺筋膜表面翻瓣后,由前向后另翻腮腺筋膜瓣,切除腮腺后将筋膜瓣复位缝合,完整保留耳大神经和腮腺筋膜。结果:耳大神经在下颌角水平之上0-2cm依次分耳后、耳垂、耳前支,神经主干末段和分支起始段均分布于腮腺筋膜浅层表面,后者致密,其致密纤维包裹在神经周围。改良手术后2例(14.3%)发生轻度Frey’s综合征,无1例发生术区皮肤长期麻木、长期面瘫、涎瘘及肿瘤复发。结论:耳大神经各分支和腮腺筋膜具有不可代替的解剖生理功能,改良术式能将两者完好保留,显著降低术后并发症。 相似文献
5.
Erez T. Yirmiya Ehud Mekori‐Domachevsky Ronnie Weinberger Michal Taler Miri Carmel Doron Gothelf 《American journal of medical genetics. Part A》2020,182(3):461-468
22q11.2 deletion syndrome (22q11.DS) is a neurogenetic disorder caused by a microdeletion in chromosome 22. Its phenotype includes high rates of psychiatric disorders, immune system abnormalities, and cognitive impairments. We assessed the quality of sleep in 22q11.2DS and its potential link to inflammatory markers and cognitive deficits. Thirty‐three 22q11.2DS individuals and 24 healthy controls were studied. Sleep parameters were assessed by the Pittsburgh sleep quality index (PSQI) questionnaire and correlated with serum cytokine levels and cognitive functioning, measured using the Penn computerized neurocognitive battery (CNB). The 22q11.2DS individuals had significantly worse sleep quality scores than the controls, unrelated to the psychiatric or physical comorbidities common to 22q11.2DS. Interleukin 6 levels were correlated with the overall score of the PSQI questionnaire for nonpsychotic 22q11.2DS participants only. Several domains of the CNB were associated with poorer sleep quality, suggesting that cognitive impairments in 22q11.2DS may be at least partially explained by poor sleep quality. Our findings confirm sleep impairments in individuals with 22q11.2DS, which might negatively affect their cognitive functioning, and corroborate a potential role of immunological pathways in the 22q11.2DS neuro‐phenotype. 相似文献
6.
In addition to being a major effector cell in the elicitation of allergic inflammation, mast cells have been found to be activated in various T cell-mediated inflammatory processes and to reside in close physical proximity to T cells. Such observations have led investigators to propose a functional relationship between these two cell populations. In this regard, we have recently reported that murine and human mast cells can be activated to both release granule-associated mediators, such as histamine and matrix metalloproteinase-9 (MMP-9), and to produce several cytokines (i.e. TNF-alpha, IL-4 and IL-6) upon physical contact, which is adhesion molecule mediated, with activated T cells. This cascade of events, whereby mast cells are activated by T cells to release certain mediators which are known to be essential for leukocyte extravasation and recruitment to affected sites, points to an important immunoregulatory function of mast cells within the context of T cell-mediated inflammatory processes. 相似文献
7.
Cutaneous responses to histamine, compound 48/80, and codeine in patients with chronic renal failure 总被引:1,自引:0,他引:1
Pruritus is a common symptom associated with chronic renal failure (CRF). But increased plasma histamine levels and skin mast cell proliferation previously reported in these patients did not correlate with the intensity of the pruritus. Since increased mast cell releasability was described in chronic idiopathic urticaria, we attempted to examine whether this mechanism could explain pruritus in patients with CRF. Twenty-five patients with end stage renal failure were skin tested with histamine, codeine, and compound 48/80. There were nine patients on continuous ambulatory peritoneal dialysis, eight patients on hemodialysis, (tested both before and after dialysis) and eight patients with advanced CRF. Wheal area after intradermal injection of three concentrations of the above substances was measured. In general, the wheal areas in all patients with CRF were either similar to or smaller than those of the control group who were without renal impairment. In conclusion, patients with CRF with or without dialysis therapy demonstrated unchanged or decreased skin test responses to histamine, codeine, and compound 48/80. Increased mast cell releasability cannot explain the pruritus in patients with CRF. 相似文献
8.
Guus MJ Bökkerink Maja Joosten Erik Leijte Maud YA Lindeboom Ivo de Blaauw Sanne MBI Botden 《Journal of pediatric surgery》2021,56(3):465-470
BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II. 相似文献
9.
男性海洛因依赖者性机能研究 总被引:1,自引:0,他引:1
目的 研究海洛因对男性性机能的影响。方法 对91例男性海洛因依赖者进行了性机能调查研究,并做性激素测定和分析。结果 男性海洛因依赖者性机能明显障碍,表现为性幻想减少,性欲减退,性高潮减退,性交频率降低。男性睾酮(T)及催乳素(PRL)均低于正常对照组(Z=8.118,P〈0.01;Z=4.444,P〈0.01),促黄体生成素(LH)及促卵泡刺激素(FSH)均高于正常对照组(Z=2.094,P〈0.05;Z=2.086,P〈0.05),雌二醇(E2)与正常对照组无统计学意义。结论 海洛因可致机体下丘脑-垂体-性腺轴功能紊乱,影响性机能,并且性问题在海洛因依赖性形成机制和戒断上的意义值得进一步探讨。 相似文献
10.
目的 观察硼替佐米(商品名:万珂,PS-341)对柔红霉素(DNR)诱导的K562耐药细胞株(K562/DNR)核因子-κB(NF-κB)、抑制蛋白κB(IκB)及P-糖蛋白(P-gp)表达的影响,探讨PS-341逆转耐药的分子机制。方法 以100 μg/ml DNR单用或联合应用4 μg/L PS-341分别作用于K562/DNR 12、24及36 h,检测不同时间点各组NF-κB、IκB及P-gp表达情况,同时测定NF-κB p65活性,检测各组细胞凋亡率。结果 Western blot结果显示:与阴性对照组相比,DNR可诱导NF-κB表达上调及活性增强、IκB表达下调、P-gp表达上调;加用PS-341可显著抑制 DNR诱导的NF-κB及P-gp表达,使IκB表达增加。加用PS-341后,NF-κB活性12 h为(15.3±1.87)%[DNR组为(23.8±2.27)%],24 h为(10.2±1.69)%[DNR组为(25.4±1.98)%],36 h为(6.08±2.53)%[DNR组为(26.9±2.58)%],与相应单用DNR组相比均有明显下降,差异有统计学意义(P值均<0.05)。DNR与PS-341联用后,细胞凋亡率12 h为(35.23±5.15)%[DNR组为(15.56±4.12)%],24 h为(40.26±6.89)%[DNR组为(17.25±2.89)%],36 h为(43.58±7.69)%[DNR组为(22.47±4.58)%],与DNR组相比,细胞凋亡率均明显增加,差异具有统计学意义(P值均<0.05)。上述作用呈时间依赖性。结论 PS-341可减少K562/DNR细胞NF-κB的活化,降低P-gp表达,逆转细胞耐药,促进细胞凋亡。 相似文献