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   14400篇
  免费   1001篇
  国内免费   387篇
耳鼻咽喉   71篇
儿科学   298篇
妇产科学   230篇
基础医学   2967篇
口腔科学   231篇
临床医学   874篇
内科学   2262篇
皮肤病学   351篇
神经病学   828篇
特种医学   188篇
外科学   2021篇
综合类   1648篇
现状与发展   1篇
预防医学   963篇
眼科学   147篇
药学   1437篇
  3篇
中国医学   390篇
肿瘤学   878篇
  2023年   191篇
  2022年   344篇
  2021年   475篇
  2020年   398篇
  2019年   660篇
  2018年   533篇
  2017年   494篇
  2016年   445篇
  2015年   508篇
  2014年   834篇
  2013年   873篇
  2012年   718篇
  2011年   984篇
  2010年   782篇
  2009年   811篇
  2008年   676篇
  2007年   768篇
  2006年   748篇
  2005年   601篇
  2004年   550篇
  2003年   456篇
  2002年   333篇
  2001年   234篇
  2000年   222篇
  1999年   168篇
  1998年   135篇
  1997年   108篇
  1996年   116篇
  1995年   92篇
  1994年   70篇
  1993年   46篇
  1992年   38篇
  1991年   33篇
  1990年   24篇
  1989年   18篇
  1988年   19篇
  1987年   20篇
  1985年   123篇
  1984年   169篇
  1983年   131篇
  1982年   164篇
  1981年   134篇
  1980年   104篇
  1979年   115篇
  1978年   70篇
  1977年   53篇
  1976年   45篇
  1975年   53篇
  1974年   29篇
  1973年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
新生儿缺氧缺血性脑病血浆Th2 源细胞因子水平的研究   总被引:3,自引:0,他引:3  
目的 研究新生儿缺氧缺血性脑病 (HIE)患儿辅助性T淋巴细胞亚群 2 (Th2 )细胞功能变化及其与HIE间的关系。 方法 采用ELISA法和单克隆抗体间接免疫荧光法 ,检测 4 6例HIE患儿不同病期血浆和外周血单个核细胞 (PBMC)体外分别产生白细胞介素 (IL) 6、IL 8、IL 10水平和T细胞IL 2受体 (IL 2R)表达率 ,并与正常足月新生儿脐血 (2 0例 )进行对照。 结果 HIE病程第 1天血浆及PBMC体外产生IL 6 [分别为 6 6 .3、80 4 .5ng L(中位数 ,以下同 ) ]、IL 8(4 10 .5、1983.6ng L)和IL 10 (2 7.9、14 0 .1ng L) ,明显高于正常脐血对照组 (分别为 1.9、187.7;91.0、76 6 .8;2 .6、16 .4ng L) (Z =4 .6 5 3~ 5 .85 6 ,P <0 .0 1) ;中重度组及并发多器官功能损害 (MOD)的HIE患儿血浆及PBMC体外产生IL 6 (分别为 86 .0、12 36 .4 ;111.3、174 6 .9ng L)、IL 8(分别为5 79.5、2 812 .2 ;5 32 .8、2 94 3.3ng L) ,分别高于轻度组 (分别为 5 2 .6、5 83.4 ;335 .3、15 2 8.9ng L)及无MOD组 (分别为 5 6 .6、713.8;35 2 .4、15 72 .4ng L)患儿 (Z =2 .2 2 8~ 2 .70 1,P <0 .0 5 ;Z =2 .877~4 .187,P <0 .0 1) ,而IL 10差异无显著性 (Z =0 .4 5 0~ 1.85 0 ,P >0 .0 5 ) ;T细胞IL 2R表达率 [(5 2 .8± 13.4 ) % ]明显  相似文献   
52.
The cytokine interleukin-10 (IL-10) plays a pivotal regulatory role in tolerizing exogenous antigens. Experimental data indicate that low cellular availability of the vitamin D hormone 1,25-dihydroxyvitamin D [1,25(OH)2D] results in a down-regulation of IL-10 concentrations. The tissue production of an adequate amount of 1,25(OH)2D depends on a high circulating 25-hydroxyvitamin D (25-OHD) level. The present study was thus aimed at evaluating the associations between season of birth, vitamin D status, and the allergy risk markers IL-10 and total immunoglobulin (IgE) in newborns. Cord blood was obtained from 49 infants born during the summer half year (mid-April to mid-October, geographic latitude 51 degrees N) and from 47 infants born during the winter half year (mid-October to mid-April, geographic latitude of 51 degrees N). Serum levels of 25-OHD were 99% higher, and IL-10 levels were 43% higher in the summer half year compared with the winter half year (p < 0.001 and p = 0.018). Moreover, the ratio of IL-10 to total IgE was 124% higher in the summer half year compared with the winter half year (p = 0.039). Serum levels of 25-OHD were correlated with IL-10 levels (r = +0.22; p < 0.05). Mothers' age, gestational ages, birth weights and serum 1,25(OH)2D levels did not differ between study groups. We conclude that the low vitamin D status of infants born in winter may at least in part adversely affect biomarkers of allergy risk.  相似文献   
53.
AIM: To investigate the association between interleukin-10 (IL-10) genetic polymorphisms and risk of POAG through a case-control study in a Han population of China. METHODS: A total of 210 patients with POAG and 420 normal subjects were recruited during the period from Dec. 2013 to Dec. 2016. The IL-10 -1082A>G (rs1800870), -819T>C (rs1800871) and -592C>A (rs1800872) polymorphisms were determined using iPlex GOLD SNP genotyping analysis (the SequenomMassARRAY® System, Sequenom, San Diego, USA). The association between IL-10 -1082A>G (rs1800870), -819T>C (rs1800871), and -592C>A (rs1800872) polymorphisms and risk of POAG was assessed by singlelogistic regression analysis. RESULTS: We observed that those carrying the CC genotype of rs1800871 was associated with an increased risk of POAG when compared with those harboring the TT genotype (OR=1.84, 95%CI=1.01-3.38). Those with AA genotype of rs1800872 had a 10.62 fold risk of POAG in comparison to the CC genotype (OR=10.62, 95%CI, 3.41-33.09). A completely linkage disequilibrium was found between IL-10 rs1800871-rs1800872 (D’=1.00, r2=0.16). The A-C-A (OR=2.60, 95%CI, 1.48-4.58) and G-T-A (OR=2.34, 95%CI, 1.42-3.86) haplotypes were associated with an increased risk of POAG, while the A-T-C haplotype showed a decreased risk of POAG (OR=0.63, 95%CI, 0.49-0.81). CONCLUSION: Our data suggest that IL-10 rs1800871 and rs1800872 can be predictive factors for the pathogenesis of POAG in the Chinese population.  相似文献   
54.
Flaviviruses present an ongoing threat to global public health, although the factors that contribute to the disease remain incompletely understood. We examined an acute Modoc virus (MODV) infection of two rodent models. Viral RNA was detected in the kidneys, spleen, liver, brain, urine, and sera of experimentally infected deer mice, a reservoir host of MODV, and Syrian hamsters, a known disease model. As expected, clinical outcomes differed between species, and the levels of viral RNA recovered from various tissues demonstrated signs of differential replication and tissue tropism. Multivariate analysis indicated significance in the profile of expressed genes between species when analyzed across tissues and over time (p = 0.02). Between-subject effects with corrected models revealed a significance specific to the expression of Ifng (p = 0.01). the expression of Ifng was elevated in hamsters as compared to deer mice in brain tissues at all timepoints. As the over-expression of Ifng has been shown to correlate with decreased vascular integrity, the findings presented here offer a potential mechanism for viral dissemination into the CNS. The expression of IL10 also differed significantly between species at certain timepoints in brain tissues; however, it is uncertain how increased expression of this cytokine may influence the outcome of MODV-induced pathology.  相似文献   
55.
目的:检测子宫内膜异位症(endometriosis,EMS)患者腹腔液中IL-6、IL-8、IL-10含量及其临床意义。方法:剖腹探查手术中采集EMS组及对照组的腹腔液,用酶联免疫吸附法(ELISA)测细胞因子水平。EMS组中,13份测IL-6,16份测IL-8,22份测IL-10,共51份,对照组检测57份。结果:EMS组和对照组IL-6的含量分别为155.88±114.92ng/L和28.74±25.88ng/L(P<0.01)。IL-8的含量分别为630.97±404.72ng/L和63.05±62.3ng/L(P<0.01)。IL-10也明显高于对照组[(38.88±38.75ng/L比10.45±4.33ng/L(P<0.01)〕。结论:EMS患者腹腔液中IL-6、IL-8及IL-10均升高,提示EMS患者的巨噬细胞活性增强,细胞因子含量增加,可干扰患者免疫调节功能。  相似文献   
56.
Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.  相似文献   
57.
目的:探讨不同病因的慢性肝病( CLD)患者肝组织中白细胞介素?10( IL?10)的表达及其与肝组织炎症和纤维化的关系。方法收集93例CLD患者及23例正常对照肝组织石蜡标本,免疫组织化学方法检测肝组织中IL?10的表达。结果不同病因的CLD患者肝组织中肝小叶及汇管区IL?10的表达均较正常对照明显增高( P<0.01)。随着肝脏炎症分级( G)的增高,CLD患者肝组织内肝小叶及汇管区IL?10的表达逐渐增强,差异有统计学意义。随着肝脏纤维化程度分期( S)的增高,CLD患者肝组织内肝小叶及汇管区IL?10的表达亦逐渐增高,差异有统计学意义。结论 IL?10可能参与CLD患者肝脏的炎症和纤维化的发生。  相似文献   
58.
59.
目的利用重组复制缺陷型腺病毒AdIL 10将外源IL 10基因导入肝星状细胞 (HSC) ,并观察其对HSC增殖的影响。方法将本实验室自行构建的重组腺病毒质粒pAdIL 10用Lipofectamin包装转染HEK 2 93细胞 ,即可获得重组腺病毒AdIL 10。应用胶原酶原位灌注和密度梯度离心法分离大鼠HSC ,当HSC生长至 80 %密度时 ,以 5× 10 4细胞 /孔接种于 96孔板 ;HSC培养 2 4h后 ,取病毒AdIL 10以感染复数 (MOI) 5 0感染HSC ;用MTT法检测HSC增殖率。结果pAdIL 10经 2 93细胞包装 ,3d后可观察到绿色荧光蛋白 (GFP)表达 ;AdIL 10感染HSC 3d后可观察到GFP表达 ,且HSC增殖受到抑制。结论重组腺病毒AdIL 10感染HSC后可抑制其增殖  相似文献   
60.
目的:观察保妇康栓对念珠菌阴道炎患者阴道分泌物中HBD-2、IL-10表达的影响,探讨其对念珠菌阴道炎患者局部免疫调节的机制。方法:选择对照组10例。念珠菌阴道炎患者60例,随机分成两组,为保妇康栓治疗组及达克宁治疗组,观察治疗前后各组患者HBD-2、IL-10表达变化。结果:念珠菌阴道炎患者阴道分泌物中HBD-2、IL-10水平与正常对照组患者比较均有显著性差异(P<0.01)。保妇康栓治疗组及达克宁治疗组患者治疗前后两者比较差异有统计学意义(P<0.05)。结论:保妇康栓对念珠菌阴道炎患者阴道分泌物中HBD-2、IL-10表达有影响,其机制可能为免疫抑制。  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