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1.
目的研究内毒素干预离体大鼠淋巴细胞后TLR4 mRNA、NF-κB mRNA的表达及IL-6分泌的变化,探讨淋巴细胞在全身炎症反应综合征(SIRS)发生及进展中的作用机制。方法制备健康雄性Wistar大鼠脾脏淋巴细胞,培养至对数期,随机分为对照组和实验组。对照组不做处理。实验组加入不等量内毒素,调整浓度为低浓度组(10 ng/ml)、高浓度组(100 ng/ml),培养3、6、12 h。RT-PCR技术检测TLR4及NF-κB的mRNA表达水平,ELISA技术测定IL-6的分泌量。结果干预3 h后,低浓度组:TLR4及NF-κB的mRNA表达与对照组比较无显著差异(P>0.05),IL-6的分泌与对照相比差异有统计学意义(P<0.05)。高浓度组:TLR4 mRNA的表达及IL-6的分泌与对照组比较差异有统计学意义(P<0.05),NF-κB的mRNA表达与对照组比较无显著差异(P>0.05)。干预6、12 h后,低、高浓度组:TLR4及NF-κB的mRNA表达与IL-6的分泌分别与对照组比较差异均有统计学意义(P<0.05)。此外,TLR4及NF-κB的mRNA表达水平及IL-6的分泌量随时间延长增加。结论内毒素能刺激大鼠淋巴细胞高表达TLR4、NF-κB及分泌包括IL-6在内的各种细胞因子与炎症介质,促进SIRS的发生及发展。  相似文献   
2.
背景:肠源性内毒素血症对肝纤维化具有启动作用,肝星状细胞(HSC)活化是肝纤维化发生、发展的中心环节。目的:探讨内毒素刺激Kupffer细胞对HSC前胶原基因表达的影响及其可能机制。方法:改良链酶蛋白酶、胶原酶原位灌流和密度梯度离心分离大鼠肝脏Kupffer细胞和HSC。以RNA斑点杂交检测脂多糖(LPS)、Kupffer细胞、LPS与Kupffer细胞共培养和肿瘤坏死因子-α(TNF-α)对HSC前胶原mRNA表达的影响,放射免疫法检测LPS对Kupffer细胞和HSC产生TNF-α的影响,RNA印迹法检测LPS和TNF-α对Kupffer细胞和HSC转化生长因子-β(TGF-β)mRNA表达的影响结果:经低浓度(0.5、1、5μg/ml)LPS处理的Kupffer细胞培养上清可增加HSCⅠ、Ⅲ、Ⅳ型前胶原mRNA表达,经高浓度(10、15、20μg/ml)LPS处理的Kupffer细胞培养上清、单独LPS、未经处理的Kupffer细胞培养上清、单独TN-α均无此作用。Kupffer细胞培养上清中的TNF-α含量随LPS浓度梯度的增加而递增,HSC培养上清中的TNF-α含量则无明显变化。TNF-α不能增加HSC TGF-βmRNA表达,但能增加Kupffer细胞TGF-βmRNA表达;经LPS或TNF-α处理的Kupffer细胞培养上清能增加HSC TGF-βmRNA表达。结论:低浓度内毒素能上调HSC前胶原基因表达,该作用有赖于内毒素激活Kupffer细胞所产生的活性介质的参与。  相似文献   
3.
肝硬化患者易并发感染,这与其免疫功能障碍密切相关。中性粒细胞作为固有免疫的主要效应细胞,其数量减少及功能损伤在肝硬化患者免疫功能障碍中起关键作用,损伤的功能包括趋化、吞噬、呼吸爆发、形成和释放中性粒细胞胞外诱捕网等。本文在近年来最新研究进展的基础上就肝硬化患者中性粒细胞功能受损的原因及其机制进行了综述,阐述了改善肝硬化患者中性粒细胞功能的一些措施,以期为肝硬化患者中性粒细胞功能损伤的机制探索及治疗提供新思路。  相似文献   
4.
AimTo evaluate the effectiveness of supplemental photodynamic therapy (PDT) in optimizing the removal of bacteria and endotoxins from primarily infected root canals after one-visit and two-visit treatments.MethodologyTwenty-four primarily infected root canals with apical periodontitis were selected and randomly divided into one-visit (n = 12) and two-visit treatment groups (n = 12). Chemo-mechanical preparation (CMP) was performed by using the single-file reciprocating technique + 2.5% NaOCL and a final rinse with 17% EDTA. The photosensitizer agent (methylene blue 0.1 mg/mL) was applied to root canals for 60 s before application of laser with a potency of 60 mW and energy density of 129 J/cm2 for 120 s after CMP in the one-visit treatment and after 14-day inter-appointment medication with Ca(OH)2 + Saline solution (SSL) in the two-visit treatment. Samples were collected before and after root canal procedures. Endotoxins were quantified by chromogenic limulus amebocyte lysate assay. Culture techniques were used to determine bacterial colony-forming unit counts.ResultsBacteria and endotoxins were detected in 100% of the initial samples, with median values of 1.97 × 105 CFU/mL and 24.983 EU/mL, respectively. The CMP using single-file reciprocating technique was effective in the reduction of bacteria and endotoxins (All, p < 0.05). The supplemental PDT was effective in reducing bacterial load in the one-visit (p < 0.05) but not in the two-visit treatment after use of Ca(OH)2 medication for 14 days (p > 0.05). In the two-visit group, after 14 days of inter-appointment medication with Ca(OH)2, a significant reduction in the median levels of endotoxins was found in comparison to CMP alone (from 1.041 to 0.094 EU/mL) (p < 0.05). Despite the type of treatment, the supplemental PDT was not effective against endotoxins (p > 0.05).ConclusionsThe photodynamic therapy optimized the disinfection of bacteria from root canals in one-visit but not for two visit treatment modality with the accomplishment of calcium hydroxide medication. Despite the type of treatment, the supplemental PDT was not effective against endotoxins.  相似文献   
5.

Objective

We conducted a pilot study to evaluate the effects of pelvic radiotherapy on biologic markers of oxidative stress and plasma endotoxin levels, and to assess the relationship between the changes of such factors and radiotherapy-related complications.

Methods

Twelve gynecologic cancer patients who were treated via pelvic radiotherapy with or without concurrent chemotherapy were enrolled in this study. Biologic markers of oxidative stress, such as glutathione (GSH) and oxidized glutathione (GSSG), as well as endotoxin levels, were measured weekly during treatment. Subjective symptoms were assessed using the Korean version of the EORTC QLQ-C30 at the baseline and on the 5th week of radiotherapy.

Results

No changes were noted in the level of GSH in whole blood, but the GSH/GSSG ratio was reduced dramatically after the initiation of radiotherapy. The mean plasma endotoxin for all patients tended to increase and persisted during radiotherapy, and the number of patients who evidenced clinically significant endotoxin levels (defined as >0.005 EU/mL) also increased. Nausea/vomiting and diarrhea were significantly changed (p=0.019 and p<0.001, respectively). A significant relationship was noted to exist between the changes in the endotoxin level and nausea/vomiting (p=0.001). However, such symptoms did not correlate with the changes of oxidative stress markers.

Conclusion

Pelvic radiotherapy oxidized the GSH redox system and increased plasma endotoxin. Further investigations containing interventional and longitudinal studies will be required to assess the effects of the changes in oxidative stress markers and endotoxin on radiotherapy-related adverse events.  相似文献   
6.
《The Journal of asthma》2013,50(4):485-496
A cross‐sectional study was conducted in Bayamón, Puerto Rico, to identify and quantify indoor allergens, serine proteases, and bacterial endotoxin present in homes of asthmatic children. A total of 126 dust samples from houses were obtained from the entire mattress and bedside floor. Most of the patients had detectable levels of mite, cockroach, cat, and dog allergens. Mold allergens were found only in bedside floor dust samples. Mouse allergens were not detected. Forty‐two percent, 36.5%, and 1.8% of the patients demonstrated exposures to sensitizing levels of mite, Bla g 1 and cat allergens, respectively. The percentage of patients exposed to high levels of allergens capable of triggering asthma symptoms was 33.3% and 26.4% for mite and Bla g 1 allergens. Only dog allergen, bacterial endotoxin, elastase, and trypsin were associated with asthma symptoms. Eighty‐nine percent of the asthmatic children were exposed to endotoxin concentrations greater than 100 EU/mg dust, and more than half of the patients were exposed to high levels of serine proteases. Our study indicates that indoor concentrations of allergens traditionally associated with asthma symptoms and severity may not be applicable in tropical environments and highly ventilated households. In fact, in the study population, endotoxins, dog allergen, and serine proteases may play a dominant role in the induction of asthma symptoms.  相似文献   
7.

Objective

An experimental model of severe injury with great lethality was studied to define the impact of bacterial translocation on survival and on inflammatory response.

Methods

Forty-one rabbits were divided into two groups: A, femur myotomy; and B, myotomy and fracture of the femoral bone. Vital signs and survival were recorded. Serum circulating endotoxins (lipopolysaccharides; LPS) were determined and tissue cultures were performed at necropsy. A subgroup of animals was sacrificed at 48 h post injury; LPS was determined in abdominal aorta and portal vein, apoptosis of spleen cells was assessed by flow cytometry, and ex vivo production of tumor necrosis factor alpha by splenocytes was measured.

Results

Tissue bacterial burden was increased in animals that died early (i.e., within 48 h after injury) versus rabbits that died later. Portal vein LPS at 48 h was increased in group B compared with group A, whereas circulating LPS did not differ. No difference in apoptosis of either lymphocytes or macrophages of the spleen was found in group B compared with group A. Following stimulation with LPS or phytohemagglutinin, tumor necrosis factor α production by splenocytes of group B was greater than that of group A.

Conclusions

Bacterial translocation primes enhanced proinflammatory responses and it is associated with early death in severe trauma.  相似文献   
8.
目的观察大鼠脑出血致多器官功能障碍综合征(MODS)模型血清内毒素与TNF-αmRNA基因表达的变化规律及相关性,探讨脑源性多器官功能障碍综合征(CMODS)的可能发生机制。方法将54只Wistar大鼠按随机化原则分为9组:正常对照组6只;假手术组6只;脑出血组42只,分为4、8、12、24、36、48和72h时相点的7个亚组,每亚组6只。向大鼠尾状核内注射Ⅶ型胶原酶0.8U加上适量肝素建立脑出血模型;分别采用偶氮显色法鲎试验定量测定血清内毒素和原位杂交技术测定肺、肝、小肠和肾组织TNF-αmRNA水平;使用CMIA真彩色医学图像分析系统,检测TNF-αmRNA的相对含量。结果脑出血组血清内毒素含量较正常对照组、假手术组明显升高(P<0.01,P<0.001),血清内毒素于术后8h开始升高,24~36h达高峰,72h仍维持较高水平。脑出血组肺、肝、小肠和肾组织TNF-αmRNA的表达自8h开始升高,24~36h达高峰,12~48h各器官组织与正常组和假手术组比较,差异均有统计学意义(P均<0.01);肺、肝、小肠和肾组织中TNF-αmRNA的表达与血清内毒素均存在显著相关性。结论大鼠脑出血致MODS模型存在内毒素血症和炎症因子TNF-α在各脏器的异常表达,提示内毒素血症刺激炎症因子TNF-α的异常释放,诱发全身炎症反应,导致MODS的发生。  相似文献   
9.
目的 评价二硫代氨基吡咯烷预先给药对LPS诱发大鼠急性肺损伤的影响.方法 健康成年Wistar大鼠54只,雌雄各半,体重180~220 g,随机分为3组:对照组(C组,n=6)、LPS组(n=24)和二硫代氨基毗咯烷预先给药组(PDTC组,n=24).LPS组腹腔注射LPS 8 mg/kg;PDTC组经尾静脉注射二硫代氨基吡咯烷120 mg/kg,30 min后腹腔注射LPS 8 mg/kg;C组注射等容量生理盐水.LPS 组和PDTC组分别于给予LPS后1、3、6和12 h时,C组于给予生理盐水后即刻,经下腔静脉取血后,各处死6只大鼠,取肺组织,采用双抗体夹心ABC-ELISA法测定血清IL-6浓度,计算肺组织湿重与干重的比值(W/D比),采用免疫组化法测定肺组织HSP70的表达和NF-κB 的活性,电镜下观察肺组织超微结构.结果 与C组比较,LPS组和PDTC组肺组织W/D比和NF-κB活性升高,HSPT0表达上调,血清IL6浓度升高(P<0.01);与LPS组比较,PDTC组肺组织W/D比和NF-κB活性降低,HSP70表达上调,血清IL-6浓度降低(P<0.01),肺组织病理损伤减轻.结论 二硫代氨基吡咯烷预先给药可减轻LPS诱发大鼠急性肺损伤,其机制可能与抑制肺组织NF-κB的活性和上调HSPT0的表达有关.  相似文献   
10.
目的 探讨血管活性肠肽(vasoactive intestinal peptide,VIP)对内毒素(脂多糖,lipopolysaceberide,LPS)致休克大鼠肺损伤后Toll样受体(Toll-like receptor,TLR)2和TLR4 mRNA表达的影响.方法 40只SD大鼠,随机分为LPS组(16只)、LPS+VIP组(16只)和对照组(8只).LPS组尾静脉注射LPS(E.coli O_(55)B_5)10 mg/kg;LPS+VIP组尾静脉注射LPS 10 ms/kg后注射VIP 5 nmol/kg;对照组尾静脉注射等容量生理盐水.分别于注射后6 h和24 h处死,留取肺标本,RT-PCR检测肺TLR2/4 mRNA表达,并观察24 h时肺组织病理变化.结果 (1)肺组织病理改变:制模24 h时.光镜和透射电镜下,LPS组见肺泡间隔弥漫性增宽、炎性细胞浸润,隔内毛细血管不同程度充血,肺泡壁增厚,肺泡腔结构破坏、炎性细胞浸润、出血、间质水肿、细胞器破坏,LPS+VIP组病变较轻.(2)TLR2/4 mRNA表达:注射LPS后6 h、24 h,肺组织TLR2/4 mRNA表达升高(F=16.638,P=0.000;t=5.876,P=0.000);24 h时LPs+VIP组TLR2/4 mRNA表达低于LPS组(F=16.676,P=0.000;t=3.9,16,P<0.001).结论 LPS致休克大鼠肺损伤时,肺组织TLR2/4 mRNA表达增强.VIP可减轻LPS所致肺损伤,其机制可能与下调重要炎症基因TLR2/4 mRNA表达有关.  相似文献   
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