全文获取类型
收费全文 | 4247篇 |
免费 | 362篇 |
国内免费 | 155篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 119篇 |
妇产科学 | 35篇 |
基础医学 | 776篇 |
口腔科学 | 40篇 |
临床医学 | 419篇 |
内科学 | 625篇 |
皮肤病学 | 100篇 |
神经病学 | 122篇 |
特种医学 | 80篇 |
外国民族医学 | 1篇 |
外科学 | 182篇 |
综合类 | 1063篇 |
预防医学 | 247篇 |
眼科学 | 22篇 |
药学 | 367篇 |
3篇 | |
中国医学 | 271篇 |
肿瘤学 | 274篇 |
出版年
2024年 | 1篇 |
2023年 | 31篇 |
2022年 | 82篇 |
2021年 | 137篇 |
2020年 | 155篇 |
2019年 | 88篇 |
2018年 | 74篇 |
2017年 | 136篇 |
2016年 | 132篇 |
2015年 | 140篇 |
2014年 | 212篇 |
2013年 | 222篇 |
2012年 | 227篇 |
2011年 | 248篇 |
2010年 | 218篇 |
2009年 | 180篇 |
2008年 | 165篇 |
2007年 | 164篇 |
2006年 | 237篇 |
2005年 | 175篇 |
2004年 | 176篇 |
2003年 | 193篇 |
2002年 | 122篇 |
2001年 | 111篇 |
2000年 | 119篇 |
1999年 | 104篇 |
1998年 | 90篇 |
1997年 | 87篇 |
1996年 | 75篇 |
1995年 | 95篇 |
1994年 | 98篇 |
1993年 | 70篇 |
1992年 | 63篇 |
1991年 | 54篇 |
1990年 | 54篇 |
1989年 | 36篇 |
1988年 | 30篇 |
1987年 | 31篇 |
1986年 | 19篇 |
1985年 | 39篇 |
1984年 | 28篇 |
1983年 | 17篇 |
1982年 | 16篇 |
1981年 | 7篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1906年 | 1篇 |
排序方式: 共有4764条查询结果,搜索用时 11 毫秒
1.
Yulu Miao Mingxia Zhang Yulin Nie Wan Zhao Bin Huang Zhengming Jiang Shaoxiong Yu Zhibin Huang Hongjin Fu 《中国神经再生研究》2007,2(2):126-128
BACKGROUND: Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE: To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN: A comparative observation. SETTINGS: Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS: All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score (GCS) was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group (GCS ranged 14- 15 points), including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS: (1) The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. (2) The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES: Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS: Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. (1) Changes of T lymphocyte subsets: At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group (t =2.77 - 3.26, P 〈 0.01), and began to recover at 7 days, which were significantly different from those in the control group (t = 2.06 - 2.24, P 〈 0.05), and generally recovered to the normal levels at 14 days (P 〉 0.05). (2) Conditions of pulmonary infections: At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% (22/30), 0, x2=37.29, P 〈 0.01]. CONCLUSION: Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period (within 7 days), and they are easily to be accompanied by pulmonary infections. 相似文献
2.
57例小儿肺炎患者T淋巴细胞亚群及NK细胞观察 总被引:1,自引:0,他引:1
为了检测肺炎患儿的免疫功能,用 APAAP 法对57例反复患支气管肺炎的患儿进行 T 淋巴细胞亚群及 NK 细胞检测,结果 CD_3~+53.20±7.64%(对照组:62.50±9.65%),CD_4~+34.2±4.36%(对照组:38.64±4.05%),CD_8~+32.50±6.39%(对照组:26.70±4.23%)。CD_4~+/CD_8~+比值1.05±0.14(对照组:1.45±0.11),NK 细胞8.30±2.40%(对照组:6.44±3.37%)。结果证明,患儿 T 细胞亚群与对照组比较差异有显著(P<0.01),NK 细胞差异无显著性(P>0.05)。 相似文献
3.
原发性肝癌患者肝切除术前、后免疫细胞表型分析 总被引:1,自引:1,他引:0
目的研究原发性肝癌(PrimaryLiverCarcinoma,PLC)患者肝切除术前、后免疫细胞表型的变化。方法采用直接免疫荧光标记,流量血细胞计数法(FlowCytometry,FCM)检测方法,动态观察120例PLC患者肝切除术前后外周血T淋巴细胞亚群、NK细胞和HLA鄄DR含量变化。结果肝切除术前肝功能Child鄄PughB级、OGTTL型和术前施行肝动脉栓塞化疗患者外周血CD8+T细胞含量明显低于正常人组,CD4+/CD8+比值则较高(P<0郾05)。全部肝癌患者肝切除术前、后CD3+CD4+T细胞和NK细胞(CD3-CD16+CD56+)含量无明显差异。术后第1天、第3天、第7天和第2周外周血淋巴细胞CD3+CD8+含量明显低于肝切除术前和术后第3周(P<0.01);而CD4+/CD8+比值则显著高于肝切除术前和术后第3周(P<0郾01)。结论PLC合并肝硬变肝储备功能不足、术前肝动脉栓塞化疗和肝切除术可导致机体细胞免疫功能低下,PLC患者肝切除术前行肝动脉栓塞化疗的价值有待深入研究。 相似文献
4.
目的:探讨支气管哮喘患者CD8+T细胞对单核/巨噬细胞抗原递呈功能的影响。方法:哮喘患者20例,健康对照22例,分别取静脉血5 mL,并分离MΦ、CD8+T细胞和B细胞。每份血样分成4组:MΦ递呈抗原组、CD8+T细胞参与MΦ递呈抗原组、CD8+T细胞体外活化后对MΦ递呈抗原影响组及自然状态下CD8+T细胞对MΦ细胞递呈抗原影响组。各组用CTLL2P抗原刺激18 h后,洗去刺激原,与自体B细胞共同孵育10 d,吸取上清液,测定特异性IgM、IgE、IgG含量。
结果:①哮喘患者MΦ单独递呈抗原,自体B细胞特异性IgM(A490值)(0.034±0.022)明显低于健康人(0.116±0.080)(P<0.05);CD8+T细胞与MΦ共同培养递呈抗原时,产生的特异性IgM(A490值)(0.031±0.021)低于健康人(0.079±0.064)(P<0.05);②哮喘患者CD8+T细胞与MΦ共同培养递呈抗原时,产生的特异性IgG(A490值)(0.102±0.041)明显高于健康人(0.081±0.067)(P<0.05),自然状态下及体外活化后CD8+T细胞与递呈抗原MΦ共同培养,产生的特异性IgG(A490值)(0.105±0.066, 0.079±0.059)与健康人(0.066±0.038, 0.069±0.047)无明显差别(P>0.05);③哮喘患者CD8+T细胞与MΦ共同培养递呈抗原产生的特异性IgE(A490值)(0.171±0.154)高于健康人(0.147±0.059)(P<0.05)。
结论:哮喘患者CD8+T细胞对MΦ递呈抗原产生免疫球蛋白有调节作用,而且参与哮喘发病。 相似文献
5.
目的 :探讨SARS患者外周血T淋巴细胞亚群变化。方法 :采用流式细胞仪检测10 0例SARS住院患者外周血T淋巴细胞亚群。结果 :与正常组比较 ,SARS组白细胞总数显著下降 ,淋巴细胞百分数和绝对数显著下降 ,粒细胞绝对数显著下降 ,CD3 、CD4 、CD8 细胞绝对数显著下降 ,CD4 细胞百分数 ,CD8 细胞百分数及CD4 /CD8 比值差异无统计学意义。比较SARS患者各病程CD3 、CD4 、CD8 ,于病程第一至第三周较第四周下降明显 (P <0 .0 5 ) ,病程第一至第三周之间差别无显著性 (P >0 .0 5 ) ;结论 :SARS患者外周血T淋巴细胞亚群的变化对阐明SARS的发病机制有一定意义。 相似文献
6.
7.
本文应用磁性磷酸酶-抗碱性磷酸酶桥联酶标技术(APAAP),对27例原发性肾小球疾病患者外周血T淋巴细胞亚群进行观察。结果表明:本组病例表现为CD细胞升高,CD细胞减少,和CD/CD比值增加。提示原发性肾小球疾病可导致细胞免疫功能改变,T淋巴细胞亚群的变化,是肾组织损害的一个间接证据,可作为临床诊断一个有价值的参考指标。 相似文献
8.
A Comparative Study on the Effect of BCG-PSN and Thymopeptides on T-lymphocyte Subsets of Normal and Immunosuppressed Mice 总被引:2,自引:0,他引:2
Polysaccharidenucleicacidfractionofbacilluscalmetteguerin (BCG PSN ,SiqikangInjection)andthymopeptidesarenowtwowidelyusedimmunomod ulatorsinclinicalpractice .Theyareusuallyusedasanadjuvanttherapyforvirusinfection ,autoimmunediseasesandneoplasms ,whichhavebeenclinicallyprovedtobeeffective .Somereportsdemonstratedthattheybothcanstimulatetheproliferationanddif ferentiationofT lymphocytes.However ,theexactmechanismshavenotbeenelucidatedyet .InordertocomparetheirmodulatingmechanismsonT lympho c… 相似文献
9.
登革病毒感染后小鼠细胞免疫功能的动态变化 总被引:2,自引:0,他引:2
从登革Ⅱ型病毒感染成年BALB/c小鼠为模型,观察感染后不同时间机体细胞免疫反应的变化。结果表明:感染后7-14d免疫功能处于激活状态,表现为腹腔巨噬细胞的吞噬功能和脾淋巴细胞对ConA的反应及IL-2产生水平都明显高于对照组,感染21d后免疫功能则转为抑制状态,上棕免疫反应明显低于对照组,脾中的L3T4^+细胞亚群的百分比逐渐下降;相反,LYT2^+细胞亚群的百分比逐渐升高,这种抑制现象可维持到 相似文献
10.
Suppressor-cell activity of peripheral blood mononuclear cells were examined and lymphocyte subsets analyzed in children with histocytosis-X and in healthy, age-matched subjects. Suppressor-cell function was assessed by two methods, the indomethacin stimulation of mitogen-activated cultures and the concanavalin A-inducible suppressor-cell assay. The results of these two assays indicate that children with active disease have significantly decreased suppressor-cell activity. Additionally, the percentage and absolute number of OKT8+ lymphocytes were decreased in children with active disease. Suppressor-cell activity and lymphocyte subsets returned to normal, baseline levels with disease remission. This study documents for the first time suppressor-cell dysfunction and supports previous investigations in which suppressor T lymphocytes are deficient in children with active disease. These findings may explain certain clinical manifestations seen in children with histiocytosis-X. 相似文献