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以正常人外周血淋巴细胞的SCE率作为细胞遗传学指标,研究了Na_2SeO_3与AFB_1相互作用对细胞遗传物质的影响。结果表明,一定浓度的Na_2SeO_3(10 ̄(-5)mol)对AFB_1所诱发的SCE有明显的抑制作用,但当浓度达到10 ̄(-2)mol时,细胞增殖受到抑制,到10 ̄(-1)mol时细胞出现毒性现象。提示Na_2SeO_3具有抑变和细胞毒性双相作用。所以在Na_2SeO_3与AFB_1相互作用的SCE实验中应避免Na_2SeO_3的浓度过高而损伤培养的细胞。 相似文献
3.
The purpose of this study was to assess the genotoxic and cytotoxic effects of the fungal metabolite aflatoxin B1 (AfB1) on the developing immune system of the chick embryo, a model in vivo system. Of particular interest was the assessment of AfB1 -mediated selective toxicity toward developing B lymphocytes as compared to T lymphocytes. In vivo bromodeoxyuridine (BrdU) labelling of DNA was used to detect the induction of sister chromatid exchanges (SCE) in lymphocytes and to assess the progression of these cells through successive cell cycles. Cytotoxicity was also assessed by studying the entrance and maintenance of cells in mitosis (mitotic index). Graded doses of AfB1 (1.09–17.4 μ/g embryo) were applied to chick embryos of 18 days of incubation (Dl). Embryos also received two doses of BrdU at 3 mg/200 μ (3 hr apart) to provide continuous labelling of B and T lymphocyte replicating DNA. B and T lymphocytes were harvested 20 hr post-AfB1/BrdU exposure from the bursa and thymus, respectively, and were processed for cytogenetic analyses. AfB1 induced dose-related increases in SCE in B lymphocytes; this induction was 6- to 8-fold that of controls at the higher doses tested, AfB1 -mediated induction of SCE in T cells was just 2-fold that of controls at the highest dose tested. AfB1 reduced the progression of B cells and to a lesser extent T ceels through successive rounds of replication. Furthermore, AfB1 dramatically reduced the mitotic index of B cells but not of T cells. These data indicate both selective genotoxicity and cytotoxicity of AfB1 toward B cells in the late stage embryo. © 1993 Wiley-Liss, Inc. 相似文献
4.
Monoclonal antibodies cross‐reactive with four major aflatoxins (AFs) were produced by fusion of P3/NS‐1/1‐AG4–1 murine myeloma cells with spleen cells isolated from a BALB/c mouse that had been immunized with aflatoxin B3‐hemisuccinate conjugated to bovine serum albumin. Six stable clones were obtained. Isotyping by enzyme‐linked immunosorbent assay (ELISA) revealed that the antibodies produced by all but two of the clones were of the IgG1 type. Of the remaining clones, one produced IgG21, and the other IgA. Competitive radioimmunoassay using tritiated AFB1 as the marker ligand revealed that two clones produced antibody that cross‐reacted well with both AFB1 and AFG1; one clone produced an antibody that had good specificity toward AFB1. The relative cross‐reactivities (RCR) of antibody produced by clone 575B8F12 for AFB1, AFB2, AFG1, and AFG2 were 100, 5, 153, and 6, respectively. The RCR of antibody produced by clone 575G4H7 for the above AFs were 100, 40, 153, and 40, respectively. The RCR of antibody produced by clone 585D4D6 for the above AFs were 100, 40, 152, and 23, respectively. Antibodies produced by the other three clones were inadequate for immunoassay because their affinities for the AFs were 100 times less than the three clones described above. 相似文献
5.
Rene E Sotomayor Melissa Washington Linh Nguyen Rahma Nyang'anyi Dennis M Hinton Ming Chou 《Toxicological sciences》2003,73(2):329-338
We studied the effects of intermittent exposure to aflatoxin B1 (AFB1) on hepatic DNA and RNA adduct formation. Fisher-344 male rats were fed 0.01, 0.04, 0.4, or 1.6 ppm of AFB1 intermittently for 8, 12, 16, and 20 weeks, alternating with 4 weeks of dosing and 4 weeks of rest. Other groups of rats were fed 1.6 ppm of AFB1 continuously for 4, 8, 12, and 16 weeks. Control rats received AFB1-free NIH-31 meal diet. AFB1-DNA and -RNA adducts were measured by HPLC with fluorescence detection. The data are presented as total DNA or RNA adducts. The DNA and RNA adduct levels increased or decreased depending on the cycles of dosing and rest. Rats removed from treatment 1 month after 1 or 2 dosing cycles (8 and 16 weeks of intermittent exposure) showed approximately a twofold decrease in DNA adduct levels and a two- to elevenfold decrease in RNA adduct levels compared with rats euthanized immediately after the last dosing cycle (12 and 20 weeks of intermittent exposure). Our data indicate that DNA and RNA adducts increased linearly, from 0.01 ppm to 1.6 ppm of AFB1 after 12 and 20 weeks of intermittent treatment. A linear dose response was also apparent for DNA but not for RNA adducts after 8 and 16 weeks of treatment. As biomarkers of exposure, AFB1-RNA adducts were three to nine times more sensitive than AFB1-DNA adducts but showed greater variability. These results suggest that binding of AFB1 to hepatic DNA is a linear function of the dose, regardless of the way this is administered. The dose-response relationship for RNA adducts depends on the length of the no-dosing cycles and on the turnover rate of RNA. 相似文献
6.
目的探讨金蒲抑瘤片对黄曲霉毒素B1(aflatoxin B1,AFB1)致肝癌作用的影响。方法实验动物随机分为高剂量、低剂量和对照组。用AFB1处理各组动物,高、低剂量组大鼠在接受AFB1期间分别喂含量为9.3和2.3g/kg的金蒲抑瘤片混合饲料,对照组喂基础饲料。8周后处死动物,观察各组动物肝组织内γ-谷氨酰转肽酶阳性肝细胞增生(γ-glu-tamyltranspeptidase-positive hyperplastic livercell,γ-GT)灶的数量和大小。结果高、低剂量金蒲抑瘤片均能减少AFB1诱发的γ-GT灶的数量和大小高、低剂量组的数量分别为0.90和3.72个/cm2,均低于对照组6.10个/cm2,抑制率分别为85%和39%,高剂量组与对照组相比差异有统计学意义,t=2.597,P=0.028。高、低剂量组的大小分别为0.24和1.94mm2/个,均低于对照组2.36mm2/个,抑制率分别为90%和17%,但差异无统计学意义,P>0.05。结论金蒲抑瘤片有减少AFB1诱发大鼠肝γ-GT灶的数量和大小的作用,而高剂量金蒲抑瘤片的减少趋势更强。 相似文献
7.
INTRODUCTION A flatoxin B1 (AFB1) , which is produced by Aspergillus flavus and Aspergillus parasitus, is a potent carcinogen in human and animals. Al- though AFB1 is best known as a liver carcinogen, it also induces lung tumors in animals and epidemio- logical studies show a positive association between human lung cancer occurrence and inhalation expo- sure to AFB1-containminated grain dust. As most of environmental carcinogens, metabolic activation cat- alyzed by cytochrome P450 (C… 相似文献
8.
Shivraj Hariram Nile Se Won Park C. N. Khobragade 《Food and Agricultural Immunology》2016,27(3):358-366
A total of 600 samples of milk from different species [buffalo (150), cow (150), goat (150), and sheep (150)] were analyzed for aflatoxin M1 (AFM1) contamination using high-performance liquid chromatography and enzyme-linked immunosorbent assay (ELISA) methods. AFM1 contamination was found in buffalo (38.6%), cow (45.3%), goat (33.3%), and sheep (36.6%) milk. The mean value of AFM1 was 0.026?µg?L?1 in buffalo, 0.018?µg?L?1 in cow, 0.014?µg?L?1 in goat, and 0.017?µg?L?1 in sheep milk. In all types of milks, the level of AFM1 concentration was higher in milk obtained from urban and semi-urban areas, whereas it was found minimal in milk from rural areas. The results of the analysis of AFM1 level by the ELISA analysis (ng?L?1) was observed in 46.5% of all samples. The amount of AFM1 in 16% buffalo, 44% cow, 10% goat, and 12% sheep milk samples was above the maximum tolerance limit accepted by the European Union. 相似文献
9.
目的探讨HBV与ATB1协同致肝癌的机理.方法用RIA法测定HBV转基因小鼠与正常小鼠暴露ATB1后0,05,1,2,4,8,24h7个不同时相肝脏ATB1DNA加成物的含量变化.结果暴露ATB1后,HBV转基因小鼠肝脏ATB1DNA加成物含量在各时相均高于正常小鼠,尤以1h高峰时相值(5592pmol/mg±415pmol/mg比4136pmol/mg±282pmol/mgDNA,P<001)及24h时相值(2487±203比989±85,P<001)最显著.24h后,转基因小鼠肝脏ATB1DNA加成物仍维持高水平,但正常小鼠已基本恢复至暴露前水平.结论HBV转基因小鼠暴露ATB1后肝脏ATB1DNA加成物含量增加可能为HBV与ATB1协同致肝癌的直接原因. 相似文献
10.
Lizy Kanungo 《Food and Agricultural Immunology》2014,25(4):467-476
A survey of aflatoxin M1 (AFM1) contamination in packaged milk and infant formula milk samples in the Goan market, India, was conducted using high performance liquid chromatography, association of analytical communities approved commercial kit and a sensitive chemiluminescent sandwich enzyme-linked immunosorbent assay (ELISA). A total of 72 samples of infant formula milk food (18) and packaged milk samples (54) was analysed. One hundred per cent of the analysed samples exceeded the European Communities recommended limits (50 ng/L) and 75% of the samples exceeded Codex Alimentarius, Food Safety and Standards Authority of India (FSSAI) and US Food and Drug Administration recommended limits (500 ng/L). The range of contamination of AFM1 was found lower in infant milk formula (501–713 ng/L) than liquid milk (511–809 ng/L). The methods were also compared for their performance, and ELISA was found to be most suitable for analysis of low-level AFM1 contamination in milk. 相似文献