全文获取类型
收费全文 | 663篇 |
免费 | 45篇 |
国内免费 | 45篇 |
专业分类
儿科学 | 40篇 |
妇产科学 | 2篇 |
基础医学 | 77篇 |
口腔科学 | 13篇 |
临床医学 | 92篇 |
内科学 | 138篇 |
皮肤病学 | 8篇 |
神经病学 | 103篇 |
特种医学 | 129篇 |
外科学 | 29篇 |
综合类 | 16篇 |
预防医学 | 17篇 |
眼科学 | 23篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 13篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 13篇 |
2011年 | 19篇 |
2010年 | 33篇 |
2009年 | 28篇 |
2008年 | 15篇 |
2007年 | 47篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 44篇 |
1997年 | 33篇 |
1996年 | 37篇 |
1995年 | 24篇 |
1994年 | 17篇 |
1993年 | 22篇 |
1992年 | 13篇 |
1991年 | 10篇 |
1990年 | 15篇 |
1989年 | 31篇 |
1988年 | 35篇 |
1987年 | 24篇 |
1986年 | 21篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有753条查询结果,搜索用时 31 毫秒
61.
Prevalence of cytomegalovirus antibody in hemophiliacs and homosexuals infected with human immunodeficiency virus type 1 总被引:1,自引:0,他引:1
We determined the prevalence of antibody to cytomegalovirus (CMV) in the sera of non-homosexual hemophilia patients and homosexual men infected with the human immunodeficiency virus type 1 (HIV-1). CMV antibody testing by latex agglutination revealed 33 of 58 HIV-1 infected hemophiliacs (57%) were antibody-positive compared with 54 of 54 HIV-1 infected asymptomatic non-hemophiliac homosexuals (100%) (p less than .001). Nine of 15 hemophiliacs (60%) with symptomatic HIV-1 infection were CMV antibody-positive. We also tested 22 HIV-1 antibody-negative hemophiliacs who had received non-heat treated factor concentrates. 14 of these 22 (64%) were CMV antibody-positive compared with 57% of HIV-1 antibody-positive hemophiliacs. We conclude 1) there is little correlation between transmission of HIV-1 and CMV by factor concentrates, 2) the presence of CMV antibody does not appear to be associated with clinical stage of HIV-1 infection in hemophiliacs, and 3) there may be a significant number of CMV antibody-negative hemophiliacs with HIV-1 infection at risk for primary infection and subsequent disease if CMV seronegative blood products are not provided for future transfusions. 相似文献
62.
Detergent-insoluble EAAC1/EAAT3 aberrantly accumulates in hippocampal neurons of Alzheimer's disease patients 总被引:1,自引:0,他引:1
Duerson K Woltjer RL Mookherjee P Leverenz JB Montine TJ Bird TD Pow DV Rauen T Cook DG 《Brain pathology (Zurich, Switzerland)》2009,19(2):267-278
Disturbed glutamate homeostasis may contribute to the pathological processes involved in Alzheimer's disease (AD). Once glutamate is released from synapses or from other intracellular sources, it is rapidly cleared by glutamate transporters. EAAC1 (also called EAAT3 or SLC1A1) is the primary glutamate transporter in forebrain neurons. In addition to transporting glutamate, EAAC1 plays other roles in regulating GABA synthesis, reducing oxidative stress in neurons, and is important in supporting neuron viability. Currently, little is known about EAAC1 in AD. To address whether EAAC1 is disturbed in AD, immunohistochemistry was performed on tissue from hippocampus and frontal cortex of AD and normal control subjects matched for age and gender. While EAAC1 immunostaining in cortex appeared comparable to controls, in the hippocampus, EAAC1 aberrantly accumulated in the cell bodies and proximal neuritic processes of CA2-CA3 pyramidal neurons in AD patients. Biochemical analyses showed that Triton X-100-insoluble EAAC1 was significantly increased in the hippocampus of AD patients compared to both controls and Parkinson's disease patients. These findings suggest that aberrant glutamate transporter expression is associated with AD-related neuropathology and that intracellular accumulation of detergent-insoluble EAAC1 is a feature of the complex biochemical lesions in AD that include altered protein solubility. 相似文献
63.
Hans HCM Savelberg Nicolaas C Schaper Paul JB Willems Ton LH de Lange Kenneth Meijer 《BMC musculoskeletal disorders》2009,10(1):16
Background
Patients with diabetic polyneuropathy (DPN) are often confronted with ulceration of foot soles. Increased plantar pressure under the forefoot has been identified as a major risk factor for ulceration. This study sets out to test the hypothesis that changes in gait characteristics induced by DPN related muscle weakness are the origin of the elevated plantar pressures. 相似文献64.
65.
Co-morbidity of TDP-43 proteinopathy in Lewy body related diseases 总被引:15,自引:15,他引:0
Nakashima-Yasuda H Uryu K Robinson J Xie SX Hurtig H Duda JE Arnold SE Siderowf A Grossman M Leverenz JB Woltjer R Lopez OL Hamilton R Tsuang DW Galasko D Masliah E Kaye J Clark CM Montine TJ Lee VM Trojanowski JQ 《Acta neuropathologica》2007,114(3):221-229
Here, we investigated if TAR-DNA-binding protein-43 (TDP-43), the disease protein in frontotemporal lobar degeneration and
ubiquitin inclusions with or without motor neuron disease as well as amyotrophic lateral sclerosis, also formed inclusions
in Lewy body (LB) disorders including Parkinson’s disease (PD) without or with dementia (PDD), and dementia with LBs (DLB)
alone or in association with Alzheimer’s disease (AD). Immunohistochemical analyses of TDP-43 in clinically well characterized
and pathologically confirmed cases of DLB + AD, PD and PDD demonstrated TDP-43 pathology in the following percentage of cases:
DLB + AD = 25/80 (31.3%); PD = 5/69 (7.2%); PDD = 4/21 (19%), while DLB and normal controls exhibited no (0/10, 0%) and one
cases (1/33, 3%) presenting TDP-43 pathology, respectively. Significant differences in the prevalence of TDP-43 lesions were
noted between disease versus normal brains (P < 0.001) as well as demented versus non-demented brains (P < 0.001). Statistical analyses revealed a positive relationship between TDP-43 lesions and several clinical and pathological
parameters in these disorders suggesting the TDP-43 pathology may have co-morbid effects in LB diseases. This study expands
the concept of TDP-43 proteinopathies by implicating TDP-43 lesions in mechanisms of neurodegeneration in LB disorders.
Hanae Nakashima-Yasuda and Kunihiro Uryu are equally contributed first authors. 相似文献
66.
Osama Al‐Jabrah BDS MSc JBPD Raghda Al‐Shammout BDS JBOrth Waddah El‐Naji BDS JBRestDent Mahasen Al‐Ajarmeh BDS JBPD Abdel‐Hakeem Al‐Quran BDS JB 《Journal of prosthodontics》2010,19(4):286-293
Purpose: The aims of this study were to compare gender differences in the width and length of the maxillary right central incisor and the horizontal and vertical overlap of the anterior teeth and to determine the relationships of these two intraoral dental biometric measurements with the amount of gingival display during smiling. Materials and Methods: A total of 61 men and 66 women were included in this study. For each participant, the gingival tissue display during smiling was judged to be either visible or not, and the maximum mesiodistal and incisogingival dimensions of the maxillary right central incisor were measured, along with the amount of horizontal and vertical overlap of anterior teeth using a digital caliper. Gender differences in these parameters and the relationship between subjects showing gingival display when smiling and the two intraoral dental biometric measurements were determined. Statistical analyses of data were performed using SPSS (V11) software. The mean scores for gender were calculated, and a Student's t‐test was used to identify significant differences between both groups. Significance level was set to 0.05. Results: The age of the participants ranged between 23 and 52, with a mean of 33.47 ± 9.07 years. A relatively small percentage of the subjects (22.05%) displayed gingiva when smiling. More women displayed gingiva when smiling than men, with a 2:1 female:male ratio. Men exhibited significantly (p < 0.05) wider (8.76 ± 0.66 mm) and longer (10.28 ± 0.88 mm) central incisors compared to women (7.92 ± 0.72 mm; 9.27 ± 0.93 mm width and length, respectively). No gender differences were found in the width‐to‐length ratio. Subjects with gingival display had significantly more horizontal (4.28 ± 1.21 mm; p < 0.001), and vertical (3.52 ± 0.66 mm; p < 0.05) overlap of anterior teeth compared to those who did not display gingiva when smiling (2.40 ± 1.03 and 2.30 ± 0.93 mm, respectively). Conclusions: Significantly more women displayed gingiva in smiling. Men had significantly wider and longer central incisors. No differences were recorded between men and women relative to both the horizontal and vertical anterior tooth overlap. Subjects who displayed gingiva when smiling had more horizontal and vertical overlap of anterior teeth. 相似文献
67.
CE Vitor CP Figueiredo DB Hara AF Bento TL Mazzuco JB Calixto 《British journal of pharmacology》2009,157(6):1034-1044
Background and purpose:
α- and β-amyrin are pentacyclic triterpenes found in plants and are known to exhibit pronounced anti-inflammatory effects. Here, we evaluated the effects of a 1:1 mixture of α- and β-amyrin (α,β-amyrin) on an experimental model of colitis in mice.Experimental approach:
Colitis was induced in Swiss male mice by trinitrobenzene sulphonic acid (TNBS) and followed up to 72 h; animals were treated systemically with α,β-amyrin, dexamethasone or vehicle. Macro- and microscopic damage, myeloperoxidase activity and cytokine levels were assessed in colons. Histological sections were immunostained for cyclooxygenase-2 (COX-2), vascular endothelial growth factor, phospho-p65 nuclear factor-κB (NF-κB) and phospho-cyclic AMP response element-binding protein (CREB)Key results:
TNBS-induced colitis was associated with tissue damage, neutrophil infiltration and time-dependent increase of inflammatory mediators. Treatment with α,β-amyrin (3 mg·kg−1, i.p.) or dexamethasone (1 mg·kg−1, s.c.) consistently improved tissue damage scores and abolished polymorphonuclear cell infiltration. α,β-Amyrin, like dexamethasone, significantly diminished interleukin (IL)-1β levels and partially restored IL-10 levels in colon tissues 72 h after colitis induction, but only α,β-amyrin reduced vascular endothelial growth factor expression by immunohistochemistry. The colonic expression of COX-2 at 24 h and that of phospho-NF-κB and phospho-CREB (peaking at 6 h) after colitis induction were consistently inhibited by both α,β-amyrin and dexamethasone.Conclusions and implications:
Systemic administration of α,β-amyrin exerted a marked and rapid inhibition of TNBS-induced colitis, related to the local suppression of inflammatory cytokines and COX-2 levels, possibly via inhibition of NF-κB and CREB-signalling pathways. Taken together, our data suggest a potential use of α,β-amyrin to control inflammatory responses in bowel disease. 相似文献68.
Sickle cell anemia patients have low erythropoietin levels for their degree of anemia 总被引:3,自引:1,他引:2
We have studied serum immunoreactive erythropoietin (SIE) levels in 28 patients with sickle cell anemia (SCA) without renal insufficiency and in 17 patients with nonhemoglobinopathy anemias of comparable severity using a sensitive radioimmunoassay procedure. An exponential relationship between SIE level and degree of anemia was noted in all patients. However, in nonhemoglobinopathy anemia, a sharp rise in the SIE level occurred as hemoglobin (Hb) levels fell below about 12 g/dL, whereas in sickle cell patients the increase was not marked until hemoglobin fell to about 9 g/dL. The response was more blunted in older SCA patients than in younger ones. A linear regression model relating SIE level to Hb level, presence/absence of SCA, and age explained 63% of the variation in SIE. We conclude that the serum erythropoietin levels in SCA increased at a lower hemoglobin concentration and are of a lower magnitude than that of the other anemias. 相似文献
69.
70.