首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   145篇
  免费   21篇
  国内免费   7篇
儿科学   1篇
基础医学   40篇
临床医学   28篇
内科学   2篇
神经病学   4篇
特种医学   19篇
综合类   56篇
预防医学   2篇
眼科学   1篇
药学   6篇
中国医学   1篇
肿瘤学   13篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2013年   1篇
  2012年   4篇
  2011年   10篇
  2010年   24篇
  2009年   22篇
  2008年   6篇
  2007年   13篇
  2006年   17篇
  2005年   21篇
  2004年   11篇
  2003年   6篇
  2002年   5篇
  2001年   6篇
  2000年   6篇
  1999年   10篇
  1995年   1篇
  1994年   3篇
  1991年   2篇
  1988年   1篇
排序方式: 共有173条查询结果,搜索用时 31 毫秒
61.
目的 探讨急性髓系白血病(AML)患者中C-kit、NPM1、FLT3基因突变的发生率和分布情况,并分析其对预后的影响.方法 应用基因测序方法分别检测656例AML患者C-kit基因8、17号外显子,NPM1基因12号外显子,FLT3基因20(酪氨酸激酶区,TKD)、14、15号外显子(内部串联重复,ITD)基因突变情况,并随访患者的预后.结果 656例AML患者中检出C-kit基因8号外显子突变6例(0.9%),17号外显子突变33例(5.0%),NPM1基因突变169例(25.8%),FLT3-TKD突变46例(7.1%),FLT3-ITD突变178例(27.1%).至少有1个突变的患者341例(50.3%).C-kit的8号外显子检测到6种突变类型;C-kit的17号外显子检测到8种突变类型;NPM1检测到15种突变类型,其中10种类型已有报道(A、B、C、D、Nm、I*、J、J+、S、13),5种类型未见报道;TKD检测到11种突变类型.t(8;21)/M2患者常伴有C-kit的17号外显子突变;inv(16)/M4患者常伴有C-kit的8号外显子突变;M3患者中除FLT3基因突变外未检测到其他突变.NPM1和ITD基因突变多见于正常核型患者,在形态学亚型中多见于M5和M1,阳性病例多伴随高白细胞计数、骨髓原始细胞增多、CD34低表达和CD33高表达.随着发病年龄的增长,突变数量增多,白细胞计数平均值增高,高白细胞计数的患者比例升高.在正常核型的群体中突变阳性的比例较其他群体增高,2种、3种突变的比例增多,差异均有统计学意义(P值均<0.01).FLT3-ITD突变阳性病例中位生存时间(10.0±1.2)个月,与阴性群体中位生存时间(17.0±2.4)个月相比差异有统计学意义(P =0.004),单独NPM1突变与否对总生存率没有显著影响,但NPM1+/ITD-患者的总生存率最高.结论 C-kit、NPM1、FLT3基因突变类型及数量在MICM分型中都有特殊的分布,并与白细胞计数、骨髓原始细胞数和预后均有相关性.对染色体核型正常的患者,基因突变可作为判断预后新的分子标志.  相似文献   
62.
目的:研究IL-24基因修饰的CIK细胞与同源树突状细胞共培养后对白血病细胞的杀伤作用及其机制.方法:从健康人外周血单个核细胞中常规诱导DC和CIK 细胞,电穿孔法将IL-24基因导入CIK细胞中(获得细胞为CIK-IL24),RT-PCR 和ELISA法检测CIK细胞中IL-24基因的表达,FCM和ELISA法检测转基因前后CIK表型及分泌细胞因子能力的变化,将CIK 细胞和同源DC共培养,FCM法检测共培养的DC-CIK细胞对HL-60细胞细胞毒活性的变化.结果:通过电穿孔法成功将IL-24基因导入CIK细胞,与对照组相比,转IL-24基因后CIK细胞中CD3~+、CD3~+CD56~+细胞的比例无明显改变,CD4~+CD25~+细胞比例显著下降.IL-24可上调CD3+CD56+细胞表面粘附分子CD54、CXCR4的表达,转染IL-24基因后CIK分泌TNF-α和IFN-γ的能力显著增强,与DC共同作用HL-60细胞时转染IL-24基因后的CIK细胞细胞毒活性明显增强.结论:通过IL-24基因修饰,明显增强了CIK细胞对HL-60细胞的杀伤能力,其机制与IL-24促进CIK分泌TNF-α、IFN-γ,上调CIK细胞表面粘附分子的表达,减少CD4~+CD25~+调节性T细胞比例等密切相关.  相似文献   
63.
目的:建立转hLIF基因腺病毒载体的饲养层细胞,观察对CD34+造血干/祖细胞的扩增作用,并研究移植辐射损伤模型SCID小鼠的效果.方法:建立转hLIF基因腺病毒载体的饲养层细胞,并用RT-PCR法鉴定目的基因;采用免疫磁珠法分离脐带血CD34+造血干/祖细胞,流式细胞术检测纯度;将CD34+造血干/祖细胞与饲养层细胞共培养,流式细胞术检测各组增殖效果,建立辐射损伤模型SCID小鼠,将扩增后的CD34+造血干/祖细胞经CFDA SE荧光标记后移植入SCID小鼠体内,通过RT-PCR和观察荧光标记细胞来检测小鼠内的人源细胞.结果:建立的转基因饲养层细胞均有绿色荧光,RT-PCR法证实有目的基因表达,免疫磁珠法分离的CD34+造血干/祖细胞纯度可达(95.6±2.58)%,与饲养层细胞共培养后CD34+造血干/祖细胞可扩增13.2倍,表面粘附分子CXCR4和CD54表达量仍较高,移植入SCID小鼠四周后,仍可见带有荧光标记的人源细胞,RT-PCR证明人源基因Alu的存在.结论:建立的转hLIF基因腺病毒载体饲养层细胞可以有效地扩增CD34+造血干/祖细胞,延缓其分化,并且有较高的移植效率和造血活性.  相似文献   
64.
目的 观察细胞因子组合对4.5 Gy γ射线照射比格犬造血系统损伤的治疗效果,为极重度骨髓型急性放射病的临床救治提供实验依据。方法 16只比格犬均给予4.5 Gy 60Co γ射线全身照射,随机分为照射对照、综合对症和细胞因子3组。细胞因子组动物在综合对症支持治疗的基础上应用rhG-CSF、rhIL-11和rhIL-2联合治疗。2 d检测1次外周血象,分别于照射前4 d,照射后1和45 d收集骨髓和外周血进行造血细胞集落培养,制备胸骨病理切片观察组织形态学改变。结果 照射后各组动物外周血各类细胞数急剧下降,细胞因子联合治疗可提高白细胞最低值(1.04×109/L,而照射对照组和综合对症组分别为0.28×109/L和0.68×109/L),缩短血小板减少持续时间(细胞因子组24 d,综合对症组33 d),使红细胞维持在正常值范围;照射后1 d骨髓及外周血中造血干细胞集落形成率明显下降,照射后45 d 2个治疗组造血干细胞集落数均恢复为照射前水平;照射对照组动物骨髓造血细胞完全消失,细胞因子治疗使得骨髓造血功能完全恢复,与照射前水平比较差异无统计学意义。结论 rhG-CSF、rhIL-11和rhIL-2联合应用可提高极期时外周血白细胞最低值,加速白细胞、血小板和红细胞恢复,促进4.5 Gy γ射线照射犬体内残留造血干/祖细胞的增殖、分化和成熟,从而加速造血功能的重建。rhG-CSF、 rhIL-11和rhIL-2不失为治疗极重度骨髓型急性放射病的有效措施。  相似文献   
65.
Objective To evaluate the effects of combined administration of recombinant human interleukin-11(rhIL-11),recombinant human G-CSF(rhG-CSF)and recombinant human interleukin-2 (rhIL-2)on acute radiation sickness(ARS)beagles.Methods Sixteen beagle were irradiated with 4.5 Gy60 Co γ-rays to establish ARS models,and were divided into irradiation control group,supportive care group and combined cytokines treatment group.After irradiation irradiation control group was given no treatment,the dogs in supportive care group received purely symptomatic treatment,while combined cytokines treatment group received rhIL-11 50μg/(kg·d)and rbG-CSF 10μg/(kg·d)subcutaneously(0-14 d)and rhIL-2 1×1 06 U/d(29-43 d)besides symptomatic treatment.Manifestation and characteristics of ARS beagles were observed,and the survival time were recorded.At last,post-mortem examination and histological examination were performed.Results All animals underwent nausea,diarrhea and fever.After irradiation,all animals in irradiation control group died in two weeks,and the mean survival time was 12.7 d,while only one died at 33 d in supportive care group.All dogs in combined cytokine group survived at 45 day after exposure,and their haematopoiesis and gastrointestinal tract were recovered.Conclusions Combination of rhIL-11 + rhG-CSF + rhIL-2 treatment could be significantly effective on ARS beagles irradiated by 4.5 Gy60 Co γ-rays,which could accelerate injured haemotopoiesis and intestinal tract recovery,increase the survival rate and improve the life quality of animals.  相似文献   
66.
Objective To explore the mechanisms of cytokines on acute radiation disease in irradiated beagles.Methods The sera of beagles irradiated with 4.5 Gy γ-rays with cytokines treatment was collected at different time points post irradiation.The two-dimensional gel electrophoresis(2-DE)was used to isolate and compare the differentially expressed proteins in sera.HD-MS was used to analyze the differentially expressed proteins with significance,and the amino acid sequences should be determined. Results High resolution 2-DE gel map was obtained.There were six differentially expressed proteins in sera of irradiated beagles at different time points.Four protein spots were successfully identified by MS.A significant spot was identified as serum amyloid A(SAA)by HD-MS,with relative molecular mass of 13 077 and isoelectfie point of 6.26.Expression of SAA was not found 1 d pre-irradiation and 36 d postirradiation,but increased slightly 1 d(0.2166)and significantly 14 d post-irradiation(0.4577). Conclusions The expression of serum amyloid A was consistent with the process of acute radiation injury,which might indicate the turnover of the disease.  相似文献   
67.
Objective To explore the clotting mechanism in beagles irradiated by 4.5 Gy γ-rays after treatment with supportive care,or supportive care and combined cytokines.Methods Sixteen beagles were divided into irradiation control group,Supportive care group and combined cytokines treatment group.Platelet aggregation test,thrombelagtography (TEG) and the time measurement were analyzed in vitro.Results In irradiation group and supportive care group,the platelet aggregation rates in beagles were decreased markedly and the k value of TEG was increased 7 d post-irradiation,while those indexes in combined cytokines treatment group changed little.At 14 d post-irradiation,each parameter of TEG in irradiated group changed obviously.The values of r,k,r+k and M were elevated significantly,clotting time and the maximum coagulation time of thrombus delayed,the Ma value was decreased markedly,and the maximum elasticity amplitude of thrombus was diminished.All parameters in combined cytokines treatment group were better than those in supportive care group.The thrombin time was prolonged obviously in irradiated group 14 d post-irradiation,while the thrombin time was the longest at 2-3 weeks post irradiation in supportive care group and combined cytokines treatment group(P>0.05).Conclusions Cytokines could improve the platelet aggregation and the blood clotting functions of beagles suffering from acute radiation sickness.  相似文献   
68.
目的:研究腺病毒介导的E1A基因(Ad-E1A)体外对Hep-2人喉癌细胞、A375人黑色素瘤细胞、SMMC-7721人肝癌细胞的生长抑制作用及敏感程度。方法:RT-PCR鉴定E1A基因的转录;MTT法检测细胞的生长抑制作用;Hoechst染色法检测细胞核形态改变;流式细胞术(FCM)检测细胞周期和细胞凋亡。结果:Ad-E1A在三种癌细胞内均有效表达,在其感染72h和96h后对Hep-2、A375、SMMC-7721细胞的生长抑制率达分别为18.65%和29.95%;33.02%和45.36%;36.32%和54.11%;其中对SMMC-7721细胞的作用最强,FCM 检测发现其凋亡率为36.92%。Hoechst染色表明Ad-E1A诱导肿瘤细胞凋亡,使其呈现典型的核固缩、断裂并出现凋亡小体等核形态改变。结论:Ad-E1A对Hep-2、A375、SMMC-7721三种癌细胞均有生长抑制作用,尤以对SMMC-7721细胞作用最强、A375细胞次之, Hep-2细胞的敏感性相对较低;此外,Ad-E1A还能诱导肿瘤细胞凋亡。  相似文献   
69.
目的研究腺病毒介导的ING4基因(简称Ad-ING4)体外对人前列腺癌细胞PC-3的生长抑制作用。方法将携有绿色荧光蛋白(GFP)的腺病毒空载体Ad(简称Ad-GFP)及Ad-ING4分别感染PC-3细胞,RT-PCR检测ING4基因的转录;荧光显微镜观察Ad-ING4对PC-3细胞的细胞毒作用;用MTT比色法绘制细胞生长曲线,计算生长抑制率;流式细胞仪(FCM)检测Ad-ING4对细胞凋亡的影响;Hoechst 33258核荧光染色检测细胞凋亡的核形态学变化。结果 RT-PCR显示Ad-ING4能在PC-3细胞内转录;MTT结果提示Ad-ING4感染72 h和96 h后对细胞生长抑制率达39.29%和50.00%;FCM检测Ad-ING4感染细胞72 h后凋亡率为76.19%;核荧光染色结果进一步证明Ad-ING4对PC-3细胞可呈现典型的细胞凋亡核形态学改变。结论 Ad-ING4能够明显抑制PC-3细胞的生长,并诱导细胞凋亡。  相似文献   
70.
Objectivc To observe the therapeutic effects of combined cytokines on hematopoietic injuries induced by 4.5 Gy60 Co γ-rays irradiation in beagles,and to provide experimental evidences for the clinical treatment of extremely severe myeloid acute radiation sickness(ARS).Methods 16 beagles were given 4.5 Gy60 Co γ-rays total body irradiation,and then randomly assigned into irradiation control group,supportive care group and cytokines group.In addition to supportive care,recombinant human granulocyte colony-stimulating factor (rhG-CSF),recombinant human interleukin-11(rhIL-11)and recombinant human interleukin-2(rhIL-2)were administered subcutaneouly to dogs in cytokines group.Peripheral blood hemogram was examined once every two days.Bone marrow and peripheral blood were collected to proceed colony cultivation 4 d pre-irradiation and 1 and 45 d post-irradiation.Conventional histopathological sections of sternum were prepared to observe the histomorphology changes. Results After irradiation,the population of all kinds of cells in peripheral blood declined sharply.WBC nadir Was elevated(1.04×109/L,but 0.28×109/L and 0.68×109/L for the irradiation control group and the supportive care group separately),the duration of thrombocytopenia was shortened (24 days,but 33 days for the supportive care groug) and red blood cell counts were maintained in the range of normal values after cytokincs treatment in combination.The colony forming efficiency of haemopoietic stem cells(HSCs)in bone marrow and peripheral blood decreased obviously 1 d post irradiation,but recovered to the level of that before irradiation 45 d post irradiation after supportive care and cytokines treatment.Hematopoietic cells disappeared in bone marrow of animals in irradiation control group,but hematopoietic functions were recovered after cytokines were administrated.Conclusions RhG-CSF.rhIL-11 and rhIL-2 used in combination could elevate WBC nadir,accelerate the recovery of leukocytes,platelets and red blood cells and promote the proliferation,differentiation and maturity of HSPCs left in the body after 4.5 Gy γ-rays total body irradiation,eventually restore the hematopoietic function.Hence,combination of rhG-CSF,rhIL-11 and rhIL-2 could serve as better therapeutic strategy to treat extremely severe myeloid ARS.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号