共查询到19条相似文献,搜索用时 218 毫秒
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研究甲醛、乙醛、丙醛、丁醛、己醛、戊醛对脱细胞-核DNA的影响。方法 将甲醛、乙醛、丙醛、丁醛、己醛、戊醛用缓冲液分别配制浓度为10 mmol/L的溶液作为受试物;用羟自由基损伤的脱细胞-核DNA断片模型检测受试物与DNA交互作用的能力;用未经羟自由基处理的脱细胞-核DNA模型检测受试物导致DNA断裂的程度。两种模型均为每组6个平行板,处理时间均为60 min,用彗星实验检测DNA拖尾情况,每张板用彗星分析软件(Comet A1.0)分析50个脱细胞-核DNA,组间差异用SPSS 18.0软件进行统计学分析。结果 经甲醛处理的脱细胞-核DNA断片模型无DNA片段泳出;经乙醛处理的脱细胞-核DNA断片模型中DNA片段泳出量明显低于对照组;其他醛类对脱细胞-核DNA断片模型的DNA断片泳出量与对照组比较差异无统计学意义;所有醛类均未导致未经羟自由基处理的脱细胞-核DNA模型的DNA断裂。结论 甲醛和乙醛均可直接与脱细胞-核DNA断片形成加合物和/或产生DNA-DNA交联,且形成加合物和/或DNA-DNA交联的能力随醛类烷基数量的增加而减弱。 相似文献
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目的 本研究拟通过彗星试来验证多层电泳槽的实用性,从而推进彗星试验的规范化.方法 从10只SD大鼠中分别提取淋巴细胞,各制作6张彗星试验载玻片,其中每只动物的一半载玻片用30% H_2O_2处理作为阳性组,另一半未处理的作为阴性组;分别用单层电泳和多层电泳开展彗星试验,并分析彗星试验结果.结果 30% H_20_2导致淋巴细胞DNA损伤;单层电泳和多层电泳的阳性组相比差异有显著性;多层电泳的不同层之间差异无显著性.结论 彗星试验同时进行电泳比分次电泳更有可比性;多层电泳槽能提高彗星试验单次电泳的样品数量,有利于彗星试验的规范化. 相似文献
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目的利用体内碱性彗星试验方法,检测长期给予纳米氧化锌颗粒(ZnO NPs)对大鼠的遗传毒性作用。方法结合扩展一代生殖毒性试验,使用13周龄的亲代SD大鼠,经口每天灌胃给予ZnO NPs 0、7、50、350 mg/kg(纳米尺度分散状态最大浓度),记录体质量变化并观察。70 d后每个剂量组取亲代大鼠雌雄各10只处死后取乙二胺四乙酸抗凝全血,采用彗星试验试剂盒进行制片,用定量分析专业软件(Casp)进行彗星结果分析。结果与溶剂对照组比较,雄性大鼠高剂量组外周血DNA损伤细胞率和尾部DNA含量百分比明显上升,分别为28.60%和(36.38±5.84)%,差异有统计学意义(P0.05);雌性大鼠高剂量组外周血DNA损伤细胞率和尾部DNA含量百分比明显上升,分别为27.31%和(18.80±2.96)%,差异有统计学意义(P0.05)。结论在350 mg/kg剂量下ZnO NPs体内碱性彗星试验结果阳性。 相似文献
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目的 本研究通过体内外联合试验探索全氟辛酸(PFOA)致DNA损伤情况。方法 以脱细胞核DNA作为模型,0.00、0.13、0.25、0.50 mmol/L PFOA染毒1 h后检测脱细胞核DNA损伤情况。以YAC-1细胞系为模型,采用CCK-8法测定不同染毒剂量对细胞活性的影响。在细胞彗星试验中,PFOA终浓度设定为0、1.0×10-8、1.0×10-7、1.0×10-6 mol/L,连续暴露3 d,检测DNA损伤情况。0、10、20、40 mg/kg·BW PFOA分别灌胃给予大鼠两次,间隔24 h,末次给予受试物6 h后,采用肝脏、骨髓和外周血细胞开展中性和碱性彗星试验,利用骨髓细胞开展骨髓微核试验。结果 脱细胞碱性彗星试验各剂量组尾部DNA含量显著高于对照组(P<0.05),呈剂量-反应关系,脱细胞中性彗星试验无显著差异(P>0.05);细胞碱性彗星试验各剂量组尾部DNA含量显著高于对照组(P<0.05),呈剂量-反应关系,细胞中性彗星试验无显著差异(P>0.05);体内彗星联合微核试验表明,与对照组相比,肝脏、骨髓和外周血细胞碱性和中性彗星试验各剂量组尾部DNA含量,以及骨髓微核各剂量组无显著差异(P>0.05)。结论 PFOA在体外对DNA具有损伤作用,经口染毒未见对大鼠产生DNA损伤。 相似文献
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麦麸多肽的毒性研究及安全性评价 总被引:3,自引:0,他引:3
目的:探讨麦麸多肽的毒性作用。方法:应用急性毒性试验、Ames试验、骨髓细胞微核试验、睾丸精母细胞染色体畸变试验、彗星试验对麦麸多肽进行毒性研究。结果:麦麸多肽灌胃,对小鼠LD50〉20g/kg,属无毒级。Ames试验中TA97、TA98、TA100和TA102的4个标准菌株无论代谢活化与否,皆为阴性结果;骨髓细胞微核试验、睾丸精母细胞染色体畸变试验、彗星试验2.5、5.0、10.0g/kgbw3个剂量组与阴性对照组比较差别无统计学意义。因此,Ames试验、骨髓细胞微核试验、睾丸精母细胞染色体畸变试验、彗星试验结果均为阴性。结论:麦麸多肽是一种无毒物质。 相似文献
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本文作者研究醋酸棉酚(gossypol acetic acid,GAA)对3株宫颈癌细胞Hela、Siha、C-33A的DNA双链断裂(double-strand break,DSB)机制。MTT法检测GAA对3株宫颈癌细胞的体外增殖的影响;单细胞凝胶电泳实验检测GAA对3株宫颈癌细胞造成的DNA双链断裂;免疫组织化学法检测GAA诱导3株宫颈癌细胞产生的磷酸化组蛋白γH2AX焦点。GAA(0~160μmol/L)以时间和浓度依赖方式抑制3株宫颈癌细胞的生长。2.5~40μmol/L的GAA作用24 h,或20μmol/L的GAA作用3~48 h,CASP软件分析显示,彗星细胞的头部DNA百分含量减少,尾长、彗星长度、尾部DNA百分含量、尾矩和Olive尾矩增加;而免疫组织化学染色结果显示,γH2AX阳性细胞率呈浓度、时间依赖性增加。3株细胞对GAA的敏感性呈现一定差异性。GAA抗肿瘤的作用机制为诱导细胞DSB,其中GAA诱导C-33A的DSB作用最强,Siha次之,Hela最弱。 相似文献
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经济和科技的发展,使软件产品在人们的生活中发挥的作用越来越大,使得人们对软件质量的要求逐渐提高。而软件测试是针对软件的质量进行的,因而它在软件开发中起到的作用就尤为重要,其实现过程对于成本的控制较为严格,力求用最小的投入最大可能地发现软件的弊端,自动化测试的出现使这个问题得到了较好地解决。文章对自动化测试平台进行概述,分析了自动化平台结构设计,阐述了自动化平台设计和实现。 相似文献
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亚硫酸钠对小鼠不同脏器的DNA损伤 总被引:2,自引:0,他引:2
本文对亚硫酸盐诱发小鼠不同脏器(脑、心、肺、胃、肝、脾、肾、胸腺和骨髓)细胞的DNA损伤进行了研究。运用单细胞凝胶电泳技术(又称彗星试验)对3个染毒组的小鼠腹腔注射125、250、500mg/kg bw亚硫酸钠和亚硫酸氢钠混合液(3:1,mol/L:mol/L),每天1次,共7d,并测量细胞DNA迁移长度。对照组小鼠腹腔注射生理盐水。结果表明,亚硫酸盐可引起受试小鼠多种脏器细胞DNA迁移长度显著增加,并具有明确的剂量一效应关系。这些结果提示亚硫酸盐可引起小鼠多种脏器细胞的DNA损伤,而不仅只作用于呼吸器官,是一种全身性DNA损伤因了,一种全身性毒物。 相似文献
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目的建立利用手机拍照, ImageJ软件自动实现菌落计数的方法。方法以大肠杆菌为测试菌,按照GB4789.2—2016《食品安全国家标准食品微生物学检验菌落总数测定》方法,获得菌落平板,手机拍照后,用Image J软件计数。并以井水、酒店预制菜、麻辣鱼仔熟食为样本比较了人工计数与Image J软件计数的差异性。结果 Image软件能对拍照后的菌落平板快速计数;人工计数和Image J软件计数结果无显著差异。结论本方法可重复性高,耗时短,克服了人工计数的缺点,保证检测溯源可查,有希望成为未来食品安全大数据体系数据采集端口。 相似文献
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DNA degradation in fresh chicken was studied with the neutral comet assay. Chicken legs were stored in a refrigerator at
2–4 °C. DNA from muscle tissue was analysed independently by the authors in Mol and Uppsala after 1–12 days. The cells were
imbedded in agarose on a microscope slide, lysed and subjected to electrophoresis causing DNA and its fragments to migrate
in the gel. The patterns ("comets") formed by the migration indicated the status of DNA. The comets were evaluated both with
a fluorescence microscope by visual inspection (H.C.) and computer-assisted image analysis (G.K.). On day 1, a majority of
the cells showed comets with very short tails, or no tail at all. A few cells showed advanced stages of DNA degradation. The
number of these cells increased with time, as well as the degree of degradation. The bacterial contamination, which was rare
on day 1, increased with time, and gave a characteristic background to day 10 samples. It was concluded that the neutral comet
assay could be used as a method to rapidly screen fresh chicken in order to assess its quality.
Received: 15 December 1997 相似文献
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DNA degradation in fresh chicken was studied with the neutral comet assay. Chicken legs were stored in a refrigerator at
2–4 °C. DNA from muscle tissue was analysed independently by the authors in Mol and Uppsala after 1–12 days. The cells were
imbedded in agarose on a microscope slide, lysed and subjected to electrophoresis causing DNA and its fragments to migrate
in the gel. The patterns ("comets") formed by the migration indicated the status of DNA. The comets were evaluated both with
a fluorescence microscope by visual inspection (H.C.) and computer-assisted image analysis (G.K.). On day 1, a majority of
the cells showed comets with very short tails, or no tail at all. A few cells showed advanced stages of DNA degradation. The
number of these cells increased with time, as well as the degree of degradation. The bacterial contamination, which was rare
on day 1, increased with time, and gave a characteristic background to day 10 samples. It was concluded that the neutral comet
assay could be used as a method to rapidly screen fresh chicken in order to assess its quality.
Received: 15 December 1997 相似文献
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Three-dimensional structural analyses of human hair fibers and comparison of the different fibers were tried by using the Ultra-high Voltage Electron Microscope (UHVEM). The analysis condition, sample preparation, and a machine state were adjusted to the suitable condition for tilting observation of from –70° to +70°, at 2° intervals. The tomography of hair fiber was successfully reconstructed from the different angle pictures with IMODE software in a computer. By using UHVEM, the various human hair fibers from Japanese and Caucasians were investigated and discussed about their structures. 相似文献
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【目的】为构建与应用雪茄烟晾制数据采集系统,获取雪茄烟晾制过程关键数据。【方法】架构以1个控制单元和若干检测单元组成的数据采集系统。控制单元由工控机和Delphi环境下开发的采集程序组成;检测单元由USB摄像头、温湿度传感器、重量传感器组成。采集程序利用DirectShow技术,实现USB摄像头视频取帧,获取雪茄烟叶图片;利用Modbus通信协议,通过串口通信采集温度、湿度、烟叶重量数据。并对温湿度及重量数据进行均值分析,对烟叶图片进行RGB值分析【结果】构建的数据采集系统采集了雪茄烟晾制过程图片与温湿度、重量数据,分析发现晾房第4~6层适宜于雪茄烟晾制,烟叶入棚1~8d为变黄、定色关键期,第8 d后颜色将不再变化;入棚14 d后烟叶重量恒定。【结论】雪茄烟晾制数据采集系统达到设计要求,满足实用性,具有在不同种植区域推广的价值;通过系统采集数据可建立雪茄烟晾制工艺数据库,为雪茄烟的自动化晾制提供基础。 相似文献
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Affective pictures have been shown to influence taste perceptions under various experimental paradigms. How are affective visual inputs associated with different tastes? More specifically, are there associations between different types of affective pictures and taste words? Here, we undertook a systematic study aimed at delineating the relationship between affective pictures and taste words. Pictures from the Chinese Affective Picture System (CAPS) and other online websites were selected, evaluated and reorganized according to the participants' hedonic and arousal ratings. The pictures were then divided into positive, neutral and negative groups according to their hedonic ratings. Each affective group was subdivided into mild, medium and strong sensations according to the arousal ratings. During the experiments, the participants were shown the pictures and were instructed to choose one of the four taste words (sour/sweet/bitter/salty) as an immediate response. The results showed that positive affective pictures were significantly associated with the word sweet. When the arousal of the positive pictures increased, the choice ratio of “sweet” increased. Negative pictures, with low to medium arousal, were significantly associated with “sour”. Negative and neutral pictures, with strong arousal, were significantly associated with “bitter”. Neutral pictures, with mild to medium arousal, were not significantly associated with any taste word. 相似文献