全文获取类型
收费全文 | 854篇 |
免费 | 27篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 45篇 |
妇产科学 | 94篇 |
基础医学 | 67篇 |
口腔科学 | 30篇 |
临床医学 | 68篇 |
内科学 | 142篇 |
皮肤病学 | 10篇 |
神经病学 | 21篇 |
特种医学 | 110篇 |
外科学 | 120篇 |
综合类 | 16篇 |
预防医学 | 54篇 |
眼科学 | 7篇 |
药学 | 59篇 |
中国医学 | 4篇 |
肿瘤学 | 52篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 15篇 |
2018年 | 11篇 |
2017年 | 9篇 |
2016年 | 16篇 |
2015年 | 19篇 |
2014年 | 19篇 |
2013年 | 35篇 |
2012年 | 32篇 |
2011年 | 28篇 |
2010年 | 37篇 |
2009年 | 46篇 |
2008年 | 46篇 |
2007年 | 46篇 |
2006年 | 35篇 |
2005年 | 38篇 |
2004年 | 38篇 |
2003年 | 39篇 |
2002年 | 30篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 10篇 |
1998年 | 30篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 24篇 |
1994年 | 24篇 |
1993年 | 18篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 14篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1941年 | 1篇 |
排序方式: 共有902条查询结果,搜索用时 15 毫秒
71.
Pneumothorax represents an extremely rare but serious and potentially life-threatening complication of colonoscopy. Here we report an unusual case of contralateral pneumothorax accompanying a perforation of the splenic flexure after preventive colonoscopy in a young outpatient. 相似文献
72.
73.
目的:观察低血糖指数的膳食对2型糖尿病患者氧化应激状态的影响。方法:2004-10/11在上海市静安区二个社区卫生服务中心招募受试者,经医生明确诊断为2型糖尿病、病程超过6个月,体质量指数≥24kg/m2的老年糖尿病志愿者43名,受试者对试验知情同意。采用随机交叉试验随机分配至低血糖指数饮食组和高血糖指数饮食组,每种膳食分别连续使用4周,间隔洗脱期4周,比较试验前后患者超氧化物歧化酶、脂质过氧化产物丙二醛和谷胱甘肽过氧化物酶含量的变化。结果:受试者依从性好,除1人因试验期间发现肿瘤而退出试验,42名志愿者按设计要求完成试验。膳食干预后低血糖指数饮食组和高血糖指数饮食组的超氧化物歧化酶活力分别升高了15.68%和21.33%,丙二醛水平分别下降23.94%和21.55%,谷胱甘肽过氧化物酶活力分别升高了15.74%和17.09%;干预后低血糖指数饮食组丙二醛下降水平与高血糖指数饮食组比较差异有显著性意义(P<0.05),而超氧化物歧化酶和谷胱甘肽过氧化物酶活性两组间差异无显著性意义(P>0.05)。结论:在控制总能量的基础上给予平衡膳食能够改善其氧化应激水平,采用低血糖指数食物有助于氧化应激水平的改善。 相似文献
74.
目的:分析力学刺激体外骨髓间充质干细胞所产生增殖分化等生物学效应的影响及其力化学信号转导途径。资料来源:因特网上检索PubMed数据库中2000-01/2006-06期间有关力学刺激对骨髓干细胞作用效应进展的英文文章,检索词“stem cel1,marrow mesenchymal stem cells,mechanical stimulation,stress”,同时检索CNKI中国知网医学文献数据库2000-01/2006-06期间的相关文章,检索词为“干细胞、骨髓间充质干细胞、机械刺激、应力”。资料选择:对资料进行筛选,选取相关文章查找全文。纳入标准:①骨髓间充质干细胞相关生物学特性。②体外细胞加载的应力分类及相应力学装置的特点。③应力对细胞影响的研究。④能获取文章的全文。排除标准:①较陈旧的文献。②重复研究。资料提炼:共收集关于86篇体外骨髓干细胞及力学干预的相关文献。其中30篇符合纳入标准。资料综合:①骨髓干细胞具有高度增殖及多向分化能力,可通过体外培养、干预作为细胞组织工程的理想种子细胞。②力学刺激是体外调节细胞生物学效应的重要途径,其中力学分类有:流体切应力、静止压应力、张应力、离心力以及单个细胞的吸吮力等,介绍各种力以及相应的力学装置的特点。③骨髓干细胞加载各种应力干预后产生的生物学效应,以及细胞应力学刺激的机制、信号转导途径。结论:力学刺激可影响骨髓间充质干细胞生物学特性,在适当的力学刺激条件下,促进细胞的增殖与分化,为骨组织工程提供新的技术手段,同时也为临床应用牵拉成骨的骨再生过程提供理论依据。 相似文献
75.
Fibroblast growth factor 2 decreases bleomycin‐induced pulmonary fibrosis and inhibits fibroblast collagen production and myofibroblast differentiation 下载免费PDF全文
Hyun Young Koo Lamis MF El‐Baz StaceyL House Sarah N Cilvik Samuel J Dorry Nahla M Shoukry Mohamed L Salem Hani S Hafez Nickolai O Dulin David M Ornitz Robert D Guzy 《The Journal of pathology》2018,246(1):54-66
Fibroblast growth factor (FGF) signaling has been implicated in the pathogenesis of pulmonary fibrosis. Mice lacking FGF2 have increased mortality and impaired epithelial recovery after bleomycin exposure, supporting a protective or reparative function following lung injury. To determine whether FGF2 overexpression reduces bleomycin‐induced injury, we developed an inducible genetic system to express FGF2 in type II pneumocytes. Double‐transgenic (DTG) mice with doxycycline‐inducible overexpression of human FGF2 (SPC‐rtTA;TRE‐hFGF2) or single‐transgenic controls were administered intratracheal bleomycin and fed doxycycline chow, starting at either day 0 or day 7. In addition, wild‐type mice received intratracheal or intravenous recombinant FGF2, starting at the time of bleomycin treatment. Compared to controls, doxycycline‐induced DTG mice had decreased pulmonary fibrosis 21 days after bleomycin, as assessed by gene expression and histology. This beneficial effect was seen when FGF2 overexpression was induced at day 0 or day 7 after bleomycin. FGF2 overexpression did not alter epithelial gene expression, bronchoalveolar lavage cellularity or total protein. In vitro studies using primary mouse and human lung fibroblasts showed that FGF2 strongly inhibited baseline and TGFβ1‐induced expression of alpha smooth muscle actin (αSMA), collagen, and connective tissue growth factor. While FGF2 did not suppress phosphorylation of Smad2 or Smad‐dependent gene expression, FGF2 inhibited TGFβ1‐induced stress fiber formation and serum response factor‐dependent gene expression. FGF2 inhibition of stress fiber formation and αSMA requires FGF receptor 1 (FGFR1) and downstream MEK/ERK, but not AKT signaling. In summary, overexpression of FGF2 protects against bleomycin‐induced pulmonary fibrosis in vivo and reverses TGFβ1‐induced collagen and αSMA expression and stress fiber formation in lung fibroblasts in vitro, without affecting either inflammation or epithelial gene expression. Our results suggest that in the lung, FGF2 is antifibrotic in part through decreased collagen expression and fibroblast to myofibroblast differentiation. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
76.
Mirac Baris Usta Ozgur Korhan Tuncel Seher Akbas Berna Aydin Gokce Nur Say 《Nordic journal of psychiatry》2016,70(2):116-120
Background: Recent evidence shows that the hypothalamic–pituitary–adrenal (HPA) axis can be dysregulated in chronic sexual abuse victims with post-traumatic stress disorder (PTSD). We hypothesized that PTSD in adolescents exposed to a single sexual trauma may function as a chronic stressor leading to HPA-axis dysregulation. Aims: The objective of this study was to assess dehydroepiandrosterone sulphate (DHEA-S) and cortisol levels in female adolescents |with single sexual trauma-related PTSD compared to healthy controls. Method: We assessed 20 female adolescent (age 12–18) single sexual trauma victims with PTSD from the Ondokuz Mayis University Department of Child and Adolescent Psychiatry between December 2013 and December 2014. PTSD symptoms were assessed using the Child Depression Inventory (CDI) and Child Posttraumatic Stress Reaction Index (CPSRI). Blood cortisol and DHEA-S were measured in 20 female adolescent sexual abuse victims with PTSD and 20 healthy adolescents after 12-h fasting using the chemiluminescence method. Results: Compared to age-matched controls, female adolescent sexual abuse victims with PTSD had significantly lower DHEA-S levels (U = 70.00, Z = ? 3.517, p = 0.01, r = 0.55). There was also a significant negative correlation between DHEA-S and CDI scores (Spearman r = ? 0.522, p < 0.01). Conclusions: Decreased DHEA-S levels and correlation with depressive symptoms are evidence for a dysregulated HPA-axis in female adolescent single sexual trauma victims with PTSD. Further research is now recommended with large patient groups in order to maximize generalizations. 相似文献
77.
Muhammet Gozdemir Burhanettin Usta Ruveyda Irem Demircioglu Bunyamin Muslu Huseyin Sert Omer Faruk Karatas 《Journal of clinical anesthesia》2010,22(3):184-189
Study ObjectiveTo determine whether magnesium sulfate (MgSO4) infusion during surgery reduces shivering during spinal anesthesia.DesignDouble-blinded placebo-controlled, randomized trial.SettingOperation room of a university hospital.Patients60 patients, aged 40 to 70 years, scheduled for elective transurethral resection of the prostate (TURP) during spinal anesthesia.InterventionsSubarachnoid anesthesia consisting of hyperbaric bupivacaine three mL 0.5% was injected using a 25-G Quincke spinal needle. Patients received either saline (Group C, n = 30) or MgSO4 (Group Mg, n = 30). Group Mg received an intravenous (IV) bolus of MgSO4 80 mg/kg via syringe pump over a 30-minute period, followed by a two g/hr infusion during the intraoperative period. Group C received an equal volume of saline.MeasurementsMotor blockade was evaluated by Bromage motor scale. Sensory block level was assessed by pinprick test. Shivering was assessed after the completion of subarachnoid drug injection. Side effects were recorded.Main ResultsHypothermia was observed in all patients (100%) in Group Mg and in 24 patients (80%) in Group C (P = 0.024). The decrease in core temperature in Group Mg was significantly greater (P < 0.005). Shivering was observed in two patients (6.7%) in Group Mg and 20 patients (66.7%) in Group C (P = 0.0001).ConclusionsMgSO4 infusion in the perioperative period significantly reduced shivering during TURP with spinal anesthesia. MgSO4 infusion prevents shivering in patients receiving spinal anesthesia but increases the risk of hypothermia. 相似文献
78.
Engin Usta Christof Burgstahler Hermann Aebert Stephen Schroeder Uwe Helber Andreas F Kopp Gerhard Ziemer 《Journal of cardiothoracic surgery》2009,4(1):43-9
Background
Cardiac allograft rejection and vasculopathy are the main factors limiting long-term survival after heart transplantation. 相似文献79.
80.
S Van der Borght V Janssens MF Schim van der Loeff A Kajemba H Rijckborst JMA Lange TF Rinke de Wit 《Bulletin of the World Health Organization》2009,87(10):794-798