全文获取类型
收费全文 | 517篇 |
免费 | 39篇 |
国内免费 | 34篇 |
专业分类
儿科学 | 16篇 |
妇产科学 | 3篇 |
基础医学 | 64篇 |
口腔科学 | 8篇 |
临床医学 | 53篇 |
内科学 | 80篇 |
皮肤病学 | 6篇 |
神经病学 | 12篇 |
特种医学 | 176篇 |
外科学 | 50篇 |
综合类 | 21篇 |
一般理论 | 2篇 |
预防医学 | 44篇 |
眼科学 | 11篇 |
药学 | 22篇 |
中国医学 | 1篇 |
肿瘤学 | 21篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 8篇 |
2012年 | 12篇 |
2011年 | 14篇 |
2010年 | 23篇 |
2009年 | 39篇 |
2008年 | 23篇 |
2007年 | 31篇 |
2006年 | 30篇 |
2005年 | 29篇 |
2004年 | 16篇 |
2003年 | 8篇 |
2002年 | 17篇 |
2001年 | 20篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 26篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 15篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 15篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1967年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有590条查询结果,搜索用时 15 毫秒
51.
52.
53.
Tongue and oropharynx: findings on MR imaging 总被引:6,自引:0,他引:6
Lufkin RB; Wortham DG; Dietrich RB; Hoover LA; Larsson SG; Kangarloo H; Hanafee WN 《Radiology》1986,161(1):69-75
Ten healthy subjects and 44 patients with diseases of the tongue or oropharynx were studied with magnetic resonance (MR) imaging. Axial, coronal, and sagittal images with a thickness of 4 mm were obtained with a pixel size of 0.75 X 0.75 mm on a 256 matrix. Nineteen of the patients underwent computed tomography (CT). Nine of those patients later had surgery, and the specimens were obtained for organ sectioning. These three studies as well as clinical history and physical examination findings were correlated. MR imaging was equal to or better than CT in those patients having both examinations. However, neither CT nor MR allowed recognition of histologic features or detection of microscopic spread of disease. Direct coronal and sagittal imaging planes on MR imaging allowed visualization of intrinsic tongue musculature, not possible with CT; this was important in recognizing subtle tumor extension. For these reasons, MR is the imaging method of choice for studying diseases of the tongue and oropharynx. 相似文献
54.
目的:观察含0.02%吡格列酮的饲料对NOD鼠糖尿病发病率的影响,分析巨噬细胞在吡格列酮预防NOD鼠糖尿病中的作用。方法:实验于2003-01/2005-01在中南大学湘雅二医院动物实验室及中心实验室完成。4周龄NOD雌鼠56只,随机数字表法分为吡格列酮组(n=25)和对照组(n=26),分别摄食含0.02%吡格列酮的混合饲料和普通营养饲料。自10周龄开始,每周测尿糖1次,尿糖阳性后用血糖仪测血糖,连续两次血糖≥16.7mmol/L即诊断为糖尿病。两组各取12周龄NOD雌鼠15只,处死前4d腹腔注射30g/L的硫代乙醇酸钠2mL,麻醉后摘除眼球法处死小鼠后腹腔灌洗收集巨噬细胞,加入脂多糖共同培养24d后收集上清,ELISA法测细胞因子肿瘤坏死因子α、白细胞介素6水平。结果:小鼠56只全部进入糖尿病发病率分析;进入腹腔巨噬细胞肿瘤坏死因子α、白细胞介素6的水平结果分析20只。①30周龄时,对照组25只小鼠有20只发生了糖尿病,发病率80.0%,平均发病时间为(139.2±38.2)d;吡格列酮组26只中有14只发生了糖尿病,发病率为53.8%,平均发病时间为(153.0±28.1)d,与对照组相比,吡格列酮组发病率明显降低(P<0.05)。②12周龄时对照组NOD鼠腹腔巨噬细胞肿瘤坏死因子α、白细胞介素6水平与吡格列酮组差异无显著性意义[(537.4±112.49),(448.9±92.18)ng/L;(551.2±108.23),(461.7±80.49)ng/L,P>0.05]。结论:吡格列酮在一定程度上预防和延缓NOD鼠糖尿病的发生;吡格列酮对NOD鼠糖尿病和胰岛炎的预防作用可能与巨噬细胞无明显关系。 相似文献
55.
SG Divers ; K Kannan ; RM Stewart ; KW Betzing ; D Dempsey ; M Fukuda ; R Chervenak ; RF Holcombe 《Transfusion》1995,35(4):292-297
BACKGROUND: Platelets become activated during storage, which results in secretion of granules, vesiculation of microparticles, secretion of protein, and a number of other biochemical and morphologic processes that decrease the utility of platelet concentrates stored for transfusion. STUDY DESIGN AND METHODS: To evaluate the quality of stored platelet concentrates, the cell surface expression of specific activation-dependent antigens (CD62 and lysosome-associated membrane proteins 1 and 2 [LAMP-1, LAMP-2]) on platelets stored in a hospital blood bank over a 7-day period was examined. Relative microparticle counts and the expression of CD62 by microparticles, as well as platelet concentrate supernatant levels of soluble CD62, were determined. RESULTS: The percentage of platelets expressing CD62 increased significantly from Day 1 to Day 5 (p < 0.05) of storage; the mean fluorescence values for CD62 did not. In contrast, the mean fluorescence values of LAMP-1 and LAMP-2 rose significantly (p < 0.01 and p < 0.05, respectively) between Days 1 and 5. Significant declines in CD62, LAMP-1, and LAMP-2 percent expression and mean fluorescence were seen on Day 6 of storage (p < 0.001). Microparticle numbers increased significantly during storage and correlated with levels of CD62 protein (free and membrane-bound) (r = 0.95 vs. Day 2, p < 0.05; r = 0.88 vs. Day 5, p < 0.05). CONCLUSION: Flow cytometric evaluations of the expression of cell surface CD62, LAMP-1, and LAMP-2 are complementary tests that, especially when used in conjunction with the quantitation of CD62 protein, provided a simple and effective means of evaluating the quality of platelet concentrates stored for transfusion. 相似文献
56.
Red cell alloimmunization in multitransfused HLA-typed patients 总被引:1,自引:0,他引:1
The authors studied retrospectively the formation of clinically significant red cell (RBC) alloantibodies in 958 HLA-typed, multiply transfused patients receiving kidney (603 patients) or liver (263 patients) transplants or plateletpheresis transfusions (92 patients). RBC alloantibodies were found in 91 (9.5%) of these patients and multiple antibodies in 35 (3.7%). Rh (D, C, c, and E) antibodies accounted for 49 percent of the total and Kell antibodies for 31 percent. Antibodies were found in 15 percent of apheresis recipients and in 8.6 percent of renal and 9.5 percent of liver transplantation patients. No association was found between any HLA-A, HLA-B, or HLA-DR phenotype and the presence of RBC alloantibodies, either in general or when analyzed according to the specific antibody. Renal transplant patients with RBC alloantibodies were somewhat more broadly HLA-alloimmunized than were those without RBC alloantibodies. Patient gender did not affect these results. The authors concluded that the immune response to RBC alloantigens is independent of HLA type but is associated with an increased level of HLA antibody formation. 相似文献
57.
目的:观察神经干细胞、许旺细胞和组织工程支架材料乙交酯-丙交酯共聚物于大鼠髓内共移植后的生物相容性,及其对大鼠损伤脊髓形态和功能的修复作用。方法:实验于2005-05/2006-09在首都医科大学附属北京市神经外科研究所损伤修复实验室完成。①实验材料:健康成年雌性Wistar大鼠36只,随机数字表法分为单纯支架组、神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组,12只/组。乙交酯-丙交酯共聚物由中科院化学研究所医用高分子材料中心提供。②实验方法:各组大鼠均建立脊髓T9半横断损伤模型。神经干细胞 许旺细胞 支架复合体组取2×1010L-1的许旺细胞、神经干细胞各10μL接种于乙交酯-丙交酯共聚物支架内,神经干细胞 支架复合体组取2×1010L-1的神经干细胞10μL接种于乙交酯-丙交酯共聚物支架内,单纯支架组取10μLDMEM培养液置于乙交酯-丙交酯共聚物支架内,于脊髓缺损处分别植入对应的复合物。③实验评估:应用电镜观察乙交酯-丙交酯共聚物支架的降解及轴突的再生状况;应用BBB评分和电生理技术检测大鼠脊髓功能性的恢复情况。结果:36只Wistar大鼠均进入结果分析。①行为学观察结果:移植术后4,12周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的后肢运动功能BBB评分均好于单纯支架组(P<0.01),其中神经干细胞 许旺细胞 支架复合体组尤为明显。②神经电生理检查结果:在脊髓半横断损伤后即刻,所有动物的体感诱发电位和运动诱发电位波幅都明显减低甚至消失。移植术后4周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的体感诱发电位和运动诱发电位波幅均有所恢复;至移植术后12周恢复明显。单纯支架组移植术后4,12周体感诱发电位和运动诱发电位波幅无明显变化。③电镜观察结果:扫描电镜下,随着时间的延长各组植入的乙交酯-丙交酯共聚物逐渐降解。透射电镜下,各组植入材料正中横断面可见新生的无髓及有髓神经纤维,至12周时神经干细胞 许旺细胞 支架复合体组最明显。结论:乙交酯-丙交酯共聚物在大鼠损伤的脊髓内具有良好的生物相容性;其与神经干细胞、许旺细胞共移植能够明显促进脊髓半横断损伤大鼠的脊髓轴突再生,并改善肢体的运动功能。 相似文献
58.
W W Downie P A Leatham V M Rhind V Wright J A Branco J A Anderson 《Annals of the rheumatic diseases》1978,37(4):378-381
59.
D Harte O Dosekun G Sethi T Chadborn A De Ruiter A Copas SG Edwards RF Miller 《HIV medicine》2010,11(2):114-120
Objectives
The aim of the study was to describe the prevalence of and examine the factors associated with immunosuppression (CD4<200 cells/μL) among HIV‐infected patients attending two large inner London treatment centres.Methods
Patients attending for care who had a CD4 count <200 cells/μL during a 6‐month period (1 January to 30 June 2007) were identified from the UK national CD4 surveillance database. Corresponding case notes were reviewed and factors associated with the most recent immunosuppressive episode examined. Patients either previously had a CD4 count >200 cells/μL at any time under follow‐up which had decreased (group A) or never had a CD4 count >200 cells/μL (group B; late presenters).Results
Of 4589 patients, 10.2% (467) had at least one CD4 count <200 cells/μL. In group A (60.1% of patients), 70.4% were not receiving antiretroviral therapy (ART) at the time at which the CD4 count fell to <200 cells/μL. Reasons included: treatment interruption (TI; 32.6%), patient declined ART (20.2%), infrequent attendance (19.1%), physician delay in offer (23.1%) and transient CD4 cell count decrease (3.9%). Among those receiving ART, one in three had poor adherence. In group B, 92.3% had started ART after presentation: most had recently started and were responding virologically. AIDS‐defining diagnoses occurred in the year preceding the decrease in CD4 cell count in 12.6% of patients in group A and 33.3% of those in group B.Conclusion
The majority of patients became immunosuppressed while under care. Our findings suggest that, in addition to strategies aimed at earlier diagnosis, there are further opportunities to reduce severe immunosuppression in patients already attending for HIV care. 相似文献60.