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Search Results: 1 - 10 of 51566 matches for " 施元旭 "
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磁性多壁碳纳米管净化技术快速测定水中多种抗生素残留
Quick Determination of Antibiotics Residues in Water Samples by Magnetic Multiwalled Carbon Nanotubes Cleaning Technology
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曹慧, , 郑军科, 王璐璐
Advances in Analytical Chemistry (AAC) , 2016, DOI: 10.12677/AAC.2016.64015
Abstract:
采用磁性多壁碳纳米管-超高效液相色谱/质谱/质谱(UPLC/MS/MS)技术测定水样中23种抗生素残留量。水样基质中的23种抗生素药物先采用磁性多壁碳纳米管(MWCNTs)富集和净化,再用5%的氨水甲醇溶液脱附,23种化合物以CORTECSTM C18+色谱柱分离,甲醇和0.1%的甲酸水溶液作为流动相,采用电喷雾正离子(ESI+)和多反应监测模式(MRM)分析,外标法定量。23种抗生素在0.5~50 μg/L的浓度范围内线性相关系数均大于0.99,检出限为0.01 μg/L,定量限为0.03 μg/L。在0.05、0.5、10 μg/L不同浓度水平下,23种抗生素的平均回收率在87.5%~105.8%之间,相对标准偏差在0.3%~4.2%之间。由于该技术简便、快速、灵敏度高,适用于水中23种抗生素残留的快速测定。
A method was established for determining 23 antibiotics residues in water samples by magnetic multiwalled carbon nanotubes and ultra performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS). The 23 antibiotics in water samples were first enriched and cleaned up by magnetic multiwalled carbon nanotubes, and then eluted with ammonium hy-droxide-methanol (5:95, v/v). The target antibiotics were separated by Waters CORTECSTM C18+ column using methanol and 0.1% formate in water as mobile phases. The analytes were detected by positive electrospray ionization with multiple reaction monitoring. External standard method was used to determine the quantity. In the linear range of 0.5~50 μg/L, the correlation coefficients of 23 antibiotics were greater than 0.99, the limit of detection (LOD) was 0.01 μg/L, and the limit of quantitation (LOQ) was 0.03 μg/L. The mean recoveries at the three spiked levels of 0.05, 0.5, 10 μg/L were 87.5%~105.8%. The relative standard deviation (RSD) was 0.3%~4.2%. The simplicity, sensitivity and good precision of the method made it be well suitable for quick determination of the 23 antibiotics residues in water samples.
话语分析的文化转向:试论建立当代中国话语研究范式的动因、目标和策略

浙江大学学报(人文社会科学版) , 2008,
Abstract: ?西方的话语分析被引入中国已有二十多年的历史.近年来,我国社会科学领域陆续有学者提出了学科中存在着照搬西方和文化失语问题.话语分析工作者和教师也应该开始考虑本学科的本土化以及学术的文化多元化问题.从东方文化的角度去揭示话语分析中西方中心论的倾向及其学术和文化后果,分析建立当代中华文化话语研究新范式的内在原因和动机,并提出具体的工作目标和行动策略.我们有确切的外部原因、真实的内部必要和条件去构建适用于当代中华文化话语的研究框架.
尾静脉注射EMT-6细胞建立转移性肺癌模型的研究
Establishment of Metastasis Lung Cancer Model by Injection of EMT-6 Cells in BALB/c Mice

魏诗航,,韦世,雪旎,何学令,刘艳,尹海林
- , 2018,
Abstract: 中文摘要: 目的 通过尾静脉注射EMT-6细胞建立一种临床特征明显、稳定可重复的转移性肺癌BALB/c小鼠模型。 方法 取对数生长期的EMT-6细胞,用0.25%胰蛋白酶消化,再用磷酸盐缓冲溶液调整细胞浓度至1×10 6个/mL(高)、5×10 5个/mL(中)和1×10 5个/mL(低)3个浓度,尾静脉注射0.2 mL EMT-6细胞悬液,对不同浓度模型的临床症状、成瘤时间、生存期、成瘤程度和病理学特征等生物学特征和评价指标进行研究,筛选出效果好的模型,并对该模型的重复性和稳定性通过3次重复实验加以确定,成功建立EMT-6细胞转移性肺癌BALB/c小鼠模型。 结果 EMT-6细胞注射后解剖小鼠发现,高浓度组小鼠7 d肺表面开始出现肿瘤灶,18 d内所有小鼠死亡;中浓度组小鼠7 d肺表面开始出现肿瘤灶,28 d内所有小鼠死亡;低浓度组小鼠14 d肺表面开始出现肿瘤灶,21 d所有小鼠肺表面均有肿瘤灶,荷瘤小鼠24 d开始出现死亡,35 d肿瘤灶数量达到顶峰(平均12~15个/只)且肿瘤体积变大,42 d内全部死亡。 结论 相比之下,低浓度模型成瘤时间到小鼠全部死亡时间,为实验研究留有4周的处理、观察、评价的窗口期,其病理组织学符合肺癌的组织学特征,临床症状指标明显,模型重复性和稳定性好,是适合转移性肺癌研究的理想模型。
英文摘要: Objective To establish a metastasis lung cancer model with apparent clinical, stable and repeatable characteristics in BALB/c mice by intravenous injection of EMT-6 breast-tumor cells. Methods Cells of EMT-6 murine mammary carcinoma at logarithmic growth phase were harvested by 0.25% trypsin digestion, and equilibrated at 3 densities of1×10 6 cells per mL (high concentration), 5×10 5 cells per mL (medium concentration), and 1×10 5 cells per mL (low concentration) in phosphate-buffered saline. And then 0.2 mL EMT-6 tumor cells were intravenously injected. The evaluation indicators and biological characteristics such as clinic appearance, the time of tumor formation, survival time, the tumor growth and pathological characteristics of metastasis lung models with different concentrations were then studied to screen the best metastasis lung cancer model. Finally, the repeatability and stability of the model were determined by 3 repeated experiments to successfully establish the metastasis lung cancer model in BALB/c mice. Results BALB/c mice were anatomized after EMT-6 tumor cells injection, and the results showed that in the group of high concentration treatment, tumor nodes on lung surface began to appear at day 7 and all animals died in 18 d; in the group of medium concentration, tumor nodes on[LM] lung surface began to appear at day 7 and all animals died in 28 d; in the group of low concentration, tumor nodes on lung surface appeared partially at day 14, all mice lung surface had tumors at day 21, the number of tumors reach the highest level (an average of 12-15/mouse), the volume of tumors became much bigger at day 35, mice began to die at day 24, and all mice died in 42 d. Conclusion We concluded that the establishment of mice models using low EMT-6 cell concentration can provide suitable 4-week time window for treatment, observation and test from tumor formation to dead, the histopathology of models' lung was consistent with clinic features of lung cancer, the clinic appearance
湖北省城区居民女性乳腺癌人群归因危险度的分析
顾源, 何尚浦, , 李国光, 朱康民, 尹祖善, 王兆, 熊天寿
中国公共卫生 , 1995,
Abstract: ?应用1:2配比的病例对照研究方法对湖北省武汉、襄樊、随州、老河口、荆沙等5个城区的女性乳腺癌发病危险因素进行了研究。多元条件Logictic回归模型分析表明,该人群乳腺癌主要的危险因素为乳腺良性病史(OR=8.47),生育胎次少(OR=1.48),初产年龄晚(OR=1.17)。将多元Logistic回归模型有关参数值带入Bruzzi公式,据病例的暴露分布估算出上述3个危险因素相应的调整人群归因危险度,分别为0.3917、0.3564、0.1414,3因素综合人群归因危险度为0.7419,并对其公共卫生的实际意义进行了探讨。
一球悬铃木优良家系及优良单株的选择
杨立国,高栅梅,,王军,唐雪,江文波,杨立伟,湫香香,季森*
南京林业大学学报(自然科学版) , 2006, DOI: 10.3969/j.jssn.1000-2006.2006.04.006
Abstract: <正>将智能决策支持系统与农药精确对靶喷雾技术有机结合起来,研究并集成了农药精确喷雾智能决策支持系统,为实现农药精确喷霉提供智能决策。在对系统目标、系统功能、系统结构分析的基础上,通过id3算法对农药喷洒进行归纳。构建了ppsidss喷雾决策树。
三氯卡班诱导小鼠乳腺上皮细胞癌变的研究
金彤,韩开顺,明珂,陈云,杜红,,王德云,武毅,刘家国
南京农业大学学报 , 2017, DOI: 10.7685/jnau.201704040
Abstract: [目的]广谱抗菌剂三氯卡班(TCC)在各种环境介质和生物体中被频繁检出。为了研究TCC对动物的危害,观察了TCC对正常小鼠乳腺上皮细胞(EpH4-Ev)的急慢性损伤作用,评价其对乳腺上皮细胞的诱癌作用,为防止TCC在动物用品中的滥用提供理论依据。[方法]采用MTT法确定TCC的最佳工作浓度后,作用于EpH4-Ev细胞,以48 h为1个药物作用循环,分别作用3和6个循环(命名为T3和T6细胞)后,使用MTT法检测细胞增殖,流式细胞术检测细胞内活性氧簇(ROS)水平,Western blot法测定细胞内磷酸化组蛋白(p-H2AX)的蛋白表达量,软琼脂克隆试验检测细胞非停泊性生长能力,细胞划痕试验测定细胞迁移能力,用此指标作为检测TCC引起细胞癌变的指标。[结果]EpH4-Ev细胞在0.195 μmol?L-1TCC作用下,细胞活性最大,故0.195 μmol?L-1为TCC的工作浓度;T3和T6细胞的细胞增殖水平、ROS水平、p-H2AX蛋白表达量及软琼脂上的细胞集落个数均显著高于细胞对照;T6细胞的细胞划痕之间的距离显著小于细胞对照。[结论]TCC能够诱导正常的EpH4-Ev细胞发生癌变。
[Objectives]In recent years,the broad-spectrum antimicrobial agent of triclocarban(TCC)was detected frequently in environment and living bodies. However,the researches of the influence of TCC on human and animal body are still poor. In this study,we investigated the acute and chronic injury effects and cell carcinogenesis of TCC on mice breast cells,and this article provides a theoretical basis to prevent TCC abuse.[Methods]The effective concentration of TCC to induce breast cells was detected by MTT assay. After that,EpH4-Ev cultures were treated with TCC for 48 h as one cycle,and this treatment was repeated for 3 and 6 cycles,respectively. Then we detected the cell proliferation by MTT method,cellular ROS(reactive oxygen species)level by fluorescence intensity of DCFH-DA and DNA damage by the expression of p-H2AX,anchorage-independent growth(AIG)by cell clone assay and cell mobility by wound healing test.[Results]Our results demonstrated that cell proliferation,cellular ROS level,expression of p-H2AX,number of cell colonies were significantly increased and distance between cells was significantly reduced after cells were persistently exposed to 0.195 μmol?L-1 TCC.[Conclusions]These results suggested that exposing the EpH4-Ev cells to low dose TCC chronically can induce cellular ROS ascend,cell proliferation increase and the extent of DNA damage aggravation. All of those mean that TCC can induce breast cells carcinogenesis
热动对晶体反向X线之影响

物理学报 , 1937,
Abstract: 著者应用鉏之Ka射线以定液态钾之构造,得液态钾之构造与液态钠者同於是知凡结晶构造同属一类之单原子物质液态构造亦同属一类而液钾态及钠之构造皆可称曰同属含心立方类(Body-centeredcubictype),蓋此类之构造与固态之含心立方晶系可证明具有密切关系也
热动对晶体反射X-线之影响

物理学报 , 1936,
Abstract: 由简单之波动力学计算,求得Debye-Waller函数结果与Zener及Jauncey者相同故Zener对六角结晶之理论与实验结果之差异,或因其计算中所用之特殊模形所致。
在居里夫人实验室的日子里

现代物理知识 , 1993,
Abstract: 六、自尊自爱,真心诚意卡拉勃尔是高中毕业后来到实验室里当实验员的,她二十来岁,眉清目秀,淡金黄色的长发披在两肩上,两颊白里透红,碧蓝的眼睛.居里夫人要她作我的助手.因为有时我的实验工作一个人干不了,必须有人帮助.她爱唱歌,但实验室内不能,也不准唱歌.只许有机器声,不许有歌声.
在居里夫人实验室的日子里

现代物理知识 , 1993,
Abstract: (一)偶然性与必然性1929年大学快毕业了,看到留美预备班的同学个个西装笔挺,趾高气扬,准备漂洋过海去美国上大学.我既羡慕又自卑,他们是天之骄子,我呢?毕业后何去何从?心中茫茫然.大学四年,家中背了一身债,急待偿还,高利贷,年利25%.站在十字路口,工作呢?还是进修?怎样工作?到哪里去进修?怎样深造,有什么机会?徘徊、苦闷、烦恼,正象在黑夜中航船,前面是一片漆黑.
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