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71.
Gestational exposure to chlorpyrifos: dose response profiles for cholinesterase and carboxylesterase activity 总被引:3,自引:2,他引:1
This study investigates the in vivo dose response profiles of the target
enzyme cholinesterase (ChE) and the detoxifying enzymes carboxylesterase
(CaE) in the fetal and maternal compartments of pregnant rats dosed with
chlorpyrifos [(O,O'-diethyl O-3,5,6-trichloro- 2-pyridyl)
phosphorothionate], a commonly used organophosphorus insecticide. Pregnant
rats were dosed daily (po) with chlorpyrifos in corn oil (0, 3, 5, 7, or 10
mg/kg) on gestational days (GD) 14-18. Animals were sacrificed 5 h after
the last chlorpyrifos dose (time of maximum brain cholinesterase
inhibition) for analysis of ChE and CaE activity in maternal blood, liver,
brain, placenta, and fetal liver and brain. The in vitro sensitivity (i.e.,
IC50, 30 min, 26 degrees C) of CaE also was determined by assaying the
activity remaining after incubation with a range of chlorpyrifos-oxon
concentrations. In vivo exposure to 10 mg/kg chlorpyrifos from GD14-18
caused overt maternal toxicity, with dose-related decreases in ChE activity
more notable in maternal brain than fetal brain. Dose-related effects were
also seen with chlorpyrifos-induced inhibition of fetal liver ChE and
maternal brain CaE activities. Gestational exposure caused no inhibition of
placental ChE or CaE, fetal brain CaE, or maternal blood CaE. ChE
activities in the maternal blood and liver, as well as fetal and maternal
liver CaE, however, were maximally inhibited by even the lowest dosage of
chlorpyrifos. The in vitro sensitivity profiles of CaE to chlorpyrifos-oxon
inhibition were valuable in predicting and verifying the in vivo CaE
response profiles. Both the in vivo and in vitro findings indicated that
fetal liver CaE inhibition was an extremely sensitive indicator of fetal
chlorpyrifos exposure.
相似文献
72.
KL Cassidy GJ Reid PJ McGrath DJ Smith TL Brown GA Finley 《Acta paediatrica (Oslo, Norway : 1992)》2001,90(11):1329-1336
The effectiveness of a eutectic mixture lidocaine-prilocaine topical anaesthetic cream (EMLA) patch compared with a placebo patch in the reduction of pain associated with intramuscular immunization was evaluated. As part of the study, 161 children (aged 4-6-y) undergoing routine diphtheria, pertussis, tetanus and polio (DPTP) immunization in five urban and five rural private office settings were randomly assigned to an EMLA patch (n = 83) or a placebo patch control group (n = 78). Pain measurements included: child's self-report on a Faces Pain Scale; facial action on the Child Facial Coding System; the Children's Hospital of Eastern Ontario Pain Scale and parent and technician ratings on a Visual Analogue Scale. Parents also rated their own and their child's immunization-related anxiety on a Visual Analogue Scale. The EMLA patch group had significantly less pain on all four pain measures compared with the placebo group. Of the children in the placebo group, 43% had clinically significant pain, compared with 17% of children in the EMLA patch group. No severe adverse symptoms occurred as a result of either EMLA or placebo patch application. CONCLUSION: The EMLA patch reduced immunization pain in 4 to 6-y-old children during needle injection. 相似文献
73.
Incidence of cervical dysplasia and cervical cancer in women living with HIV in Denmark: comparison with the general population 下载免费PDF全文
74.
In vivo and in vitro MR imaging of renal tumors: histopathologic correlation and pulse sequence optimization 总被引:1,自引:0,他引:1
Quint LE; Glazer GM; Chenevert TL; Fechner KP; Gikas PW; Shireman PK; Grossman HB; Li KC 《Radiology》1988,169(2):359-362
Magnetic resonance (MR) imaging has given mixed results in the detection of renal masses. To identify the reasons for this and to determine the optimal pulse sequences for evaluating renal tumors, the authors imaged 12 primary renal tumors in vivo and 17 in vitro at 0.35 T. Histopathologic findings for each specimen were closely correlated with the MR images. Four of seven solid tumors imaged in vivo were isointense with surrounding normal renal parenchyma at all pulse sequences. The other three tumors were hyperintense in vivo at T2-weighted sequences. At heavily T2-weighted sequences eight solid tumors were hyperintense in vitro and four were hypointense. There was no correlation between signal intensity and specific tissue type or histologic pattern for solid tumors. The five cystic tumors were well seen both in vivo and in vitro on T2-weighted images. However, the signal intensity of the cyst fluid was an unreliable indicator of benignancy. SE MR imaging at 0.35 T has significant limitations in the detection of solid renal masses. 相似文献
75.
ML Von Linstow V Rosenfeldt AM Lebech M Storgaard T Hornstrup TL Katzenstein G Pedersen T Herlin NH Valerius N Weis 《HIV medicine》2010,11(7):448-456
Objectives
The aim of this study was to describe trends in the management of pregnancies in HIV‐infected women and their outcomes over a 14‐year period in Denmark on a national basis.Methods
The study was a retrospective cohort study of all HIV‐infected women in Denmark giving birth to one or more children between 1 June 1994 and 30 June 2008.Results
We identified 210 HIV‐infected women with 255 pregnancies, ranging from 7 per year in 1995 to 39 per year in 2006. Thirty per cent of the women were Caucasian and 51% were Black African. Knowledge of HIV status before pregnancy increased from 8% (four of 49) in 1994–1999 to 80% (164 of 206) in 2000–2008. Only 29% (53 of 183) of the women chose to consult an infectious disease specialist when planning pregnancy, while 14% (27 of 199) received assistance with fertility. The proportion of women on antiretroviral therapy (ART) increased from 76% (37 of 49) in 1994–1999 to 98% (201 of 206) in 2000–2008. Vaginal deliveries ranged from 0 in 2003 to 35% of pregnancies in 2007. Mother‐to‐child transmission (MTCT) of HIV decreased from 10.4% in 1994–1999 to 0.5% in 2000–2008. All women giving birth to an HIV‐positive child were diagnosed with HIV during or after delivery and did not receive prophylactic ART.Conclusions
The annual number of HIV pregnancies increased fivefold during this 14‐year period and substantial changes in pregnancy management were seen. No woman treated according to the national guidelines, i.e. ART before week 22, intravenous zidovudine (ZDV) during labour, neonatal ZDV for 4 to 6 weeks and no breastfeeding, transmitted HIV to her child. 相似文献76.
Complement-induced vesiculation and exposure of membrane prothrombinase sites in platelets of paroxysmal nocturnal hemoglobinuria 总被引:4,自引:4,他引:4
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem-cell disorder in which the glycolipid-anchored membrane proteins, including the cell-surface complement inhibitors, CD55 and CD59, are partially or completely deleted from the plasma membranes of mature blood cells. To gain insight into the pathogenesis of thrombosis that is frequently observed in this disorder, the procoagulant responses of PNH platelets exposed to the human terminal complement proteins C5b-9 were investigated. C5b-9 complexes were assembled on gel-filtered platelets by incubation with purified C5b6, C7, C9, and limiting amounts of C8. Platelet microparticle formation and exposure of plasma membrane- binding sites for coagulation factor Va were then analyzed by flow cytometry. PNH platelets exhibiting undetectable levels of surface CD59 antigen showed an approximately 10-fold increase in sensitivity to C5b- 9-stimulated expression of membrane-binding sites for factor Va when compared with platelets from normal controls. Expression of catalytic surface for the prothrombinase complex (VaXa) paralleled the exposure of factor Va-binding sites; the rate of prothrombin conversion by C5b-9- treated PNH platelets exceeded that of C5b-9-treated normal controls by approximately 10-fold at the maximal input of C8 tested (500 ng/mL). These data indicate that PNH platelets deficient in plasma membrane CD59 antigen are exquisitely sensitive to C5b-9-induced expression of prothrombinase activity, and suggest that the tendency toward thrombosis in these patients may be due, at least in part, to the deletion of this complement inhibitor from the platelet plasma membrane. 相似文献
77.
应用野生体和去糖基化突变体肾素元cDNA,转染GH4细胞,经35S代谢标记表达产物,免疫沉淀,SDS/PAGE电泳检测观察去糖基后肾素元结构与功能的变化.发现去糖基化后的肾素元突变体,除半衰期缩短外,其分子粘度明显增高,转染细胞清除作为代谢标记去糖基化肾素元的时间延长。说明肾素元的糖基化的对其分子不仅在自稳中起重要作用,同时在成熟中可能也有重要生物学意义。 相似文献
78.
We examined the selective effects of interleukin (IL-5) in regulating the maturational expression of surface adhesion molecules on human eosinophils and adhesion to endothelial cells during eosinophiiopolesis in vitro. Expression of the beta 2 integrins (CD11/CD18) and the beta 1 integrin, VLA-4 (CD49d/ CD29), was assessed during development in culture with IL-3, IL-5, and granulocyte-macrophage colony stimulating factor in cultures of human umbilical cord blood-derived eosinophil (CDE) precursor cells. Expression of both CD11b and CD18 subunits of Mac-1 was lower on CDE which were continuously (= chronically) exposed to IL-5 than on CDE which were cultured without IL-5 for the final week of culture. CD11b expression on cells grown without IL-5 was 71.3 +/- 5.92 (mean specific fluorescence value [MSF] as measured by flow cytometry) versus 52.5 +/- 4.48 MSF for Mac-1 alpha (CD11b) on CDE grown in the continued presence of 2 x 10 - 11 mol/L IL-5 (P < .01). Although expression of VLA-4 decreased as CDE matured, expression of CD29 and CD49d were similar regardless of cytokine exposure for the final week of culture. For eosinophils cultured without IL-5, acute stimulation with 10 - 8 mol/L IL-5 increased CD11b surface expression and increased the number of cells adhering to unstimulated human umbilical vein endothelial cells (HUVEC) from 4,570 +/- 780 cells (9.14 +/- 1.56% adhesion) to 8,385 +/- 515 cells (16.8 +/- 1.03% adhesion) (P < .01). Basal adhesion to unstimulated HUVEC of CDE cultured continuously with IL-5 was comparable (8.62 +/- 1.12% adhesion; P = NS), but neither CD11b expression (50.3 +/- 11.8 MSF; P = NS v control) nor adhesion to HUVEC (6.77 +/- 1.35%; P = NS) was enhanced in these eosinophils after acute stimulation with IL-5. Blockade of adhesion to IL-1-stimulated HUVEC caused by the anti-CD49d monoclonal antibody (MoAb), HP2/1, was comparable for cells cultured with IL-5 and without IL-5. However, the anti-CD18 MoAb, R15.7, caused 47.6 +/- 5.08% inhibition of adhesion of eosinophils cultured without IL-5 and only 25.8 +/- 5.20% for cells cultured continuously with IL-5 (P < .01), and failed to block significantly the adhesion of only the latter cells to IL-4-stimulated HUVEC. Our data show that continuous, chronic exposure to low concentrations of IL-5 causes decreased expression of Mac-1 and refractoriness to acute stimulation with IL-5 of adhesion to HUVEC. These data further demonstrate that CDE maturing in the continued presence of IL-5 adhere to HUVEC predominantly through VLA-4 ligation. 相似文献
79.
目的:观察褪黑素对体外培养淋巴细胞增殖及促进细胞因子分泌的作用。方法:实验于2004-10/2006-10在解放军第一二三医院南京军区肝病中心实验室完成。①实验材料:Wistar大鼠,雄性,3月龄,体质量(230±20)g,购自上海斯莱克实验动物有限责任公司。褪黑素:美国Sigma公司产品。②实验方法:采用弗氏完全佐剂加肝细胞特异性脂蛋白法建立自身免疫性肝炎大鼠模型。分别抽取正常大鼠及模型大鼠的外周血,实验室常规培养,并将其分为3组:褪黑素组培养基中加褪黑素使终浓度为2mg/L;促肝细胞生长素组培养基中加促肝细胞生长素使终浓度为2mg/L;空白对照组培养基中不加任何细胞分裂刺激剂。③实验评估:培养48h后,对外周血淋巴细胞进行常规计数并采用液体闪烁计数仪记录1min计数结果值。用于观察褪黑素与促肝细胞生长素促进外周血淋巴细胞增殖的效果。并检测培养上清液中的各细胞因子浓度,用于观察褪黑素与促肝细胞生长素促进外周血淋巴细胞分泌细胞因子的作用。结果:①褪黑素对正常大鼠外周血淋巴细胞有促进增殖作用,细胞数与1min计数值较空白对照组明显升高(P<0.05),促肝细胞生长素无促进外周血淋巴细胞增殖作用。②褪黑素对模型大鼠外周血淋巴细胞有促进增殖作用,细胞数与1min计数值较空白对照组明显升高(P<0.05),促肝细胞生长素无促进外周血淋巴细胞增殖作用。③在褪黑素作用下,正常大鼠Th1细胞因子IL-2和IFN-γ水平明显高于空白对照组和促肝细胞生长素组(P<0.01),Th2细胞因子IL-6明显升高(P<0.05),IL-4水平与空白对照组比较,差异不显著(P>0.05),促肝细胞生长素组Th1和Th2细胞因子与空白对照组无明显差异(P>0.05)。④在褪黑素作用下,模型大鼠Th1细胞因子IL-2和IFN-γ水平较空白对照和促肝细胞生长素组明显升高(P<0.05),Th2细胞因子IL-4和IL-6水平与空白对照和促肝细胞生长素组无明显差异(P>0.05)。结论:褪黑素对自身免疫性肝炎大鼠外周血淋巴细胞有较强的刺激分裂作用。 相似文献
80.
BACKGROUND: Chloramphenicol-dependent antibodies are a rare cause of interference in pretransfusion serologic testing. Their presence can be confirmed by the testing of red cells in both the presence and absence of chloramphenicol. CASE REPORT: A 29-year-old, group A, Rh-positive man with no history of chloramphenicol exposure was found to have a chloramphenicol-dependent panagglutinin in his serum. The antibody was IgM with a titer of 8. It showed no blood group specificity when tested with common and rare red cell phenotypes, and it failed to react with platelets and granulocytes. Confirmation attempts using a chloramphenicol sodium succinate solution as the cell-suspending medium led to negative results. The antibody reacted serologically only in the presence of chloramphenicol, which arises from the succinate derivative by the action of blood esterases. CONCLUSION: This case is an additional example of a chloramphenicol-dependent antibody. It demonstrates how the laboratory investigation of drug-related phenomena is dependent on testing the drug from that reacts in vivo. 相似文献