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Search Results: 1 - 10 of 165987 matches for " 杨慧君 "
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金鱼草S核酸酶在大肠杆菌中的表达
,薛勇彪
科学通报 , 1999,
Abstract: 在许多显花植物中,自交不亲和性由复等位基因构成的被称为S位点的单一遗传位点控制.在茄科、玄参科和蔷薇科中,迄今已知的唯一S位点编码的产物为一类核酸酶,称为S核酸酶(SRNases),为S位点在花柱中的产物,参与自交不亲和性的表达.作为研究和比较其三维结构的第一步,在大肠杆菌(E.coli)中成功地表达了具有生物活性的金鱼草的3种S核酸酶基因(S2,S4和S5)编码的核酸酶,结果表明这些基因的表达对E.coli的生长没有影响,为体外大量分离S核酸酶奠定了基础.还讨论了S核酸酶表达对E.coli不致死的可能原因.
应用于人体关节缺损修复的建模与可视化
,,李勤
中国图象图形学报 , 2014, DOI: 10.11834/jig.20140216
Abstract: 目的关节缺损疾病治疗目前存在的主要问题是缺乏精确的关节模型以及个体化的修复方案,为此提出量化关节骨缺损的精确建模与可视化方法。方法利用骨骼图像增强、多模态影像融合、关节结构分割、关节病变结构建模与定量分析等核心关键技术,从关节CT或MRI影像中构建和恢复缺损关节的空间立体结构,为关节缺损信息提供量化参数和3维模型,从而帮助医生快速准确地对关节缺损疾病进行诊疗。结果针对建模与可视化方法中的核心关键技术进行了深入研究,实验结果显示上述方法能够为关节缺损修复提供精确的3维量化模型。结论基于CT、MRI影像的关节结构建模与可视化技术为评价骨缺损大小提供了精确有效的方法,在关节盂或肱骨结构等疾病的诊疗方面具有重要的临床意义,此项技术的发展对关节缺损疾病的修复发挥着重要作用。
载ni双功能碱性沸石催化剂的研究
,,孟中岳
物理化学学报 , 2000,
Abstract: 采用分步浸渍法制备了负载ni和koh的nax沸石催化剂,用xrd、tpr、co2tpd和xps等手段对样品的结构、表面碱性、金属组分的可还原性、表面ni物种的形态等进行了表征,对金属组分和碱性组分间的相互作用进行了研究,并揭示了这种作用的本质.同时结合丙酮一步法合成甲基异丁基酮的反应,探讨了反应性与样品碱性、金属性的关系,阐明了该反应中双功能催化剂上金属组分与碱性组分必须匹配合宜的原因.
右美托咪定对七氟醚吸入全身麻醉术后恢复质量的影响
,赵嫣红,刘健
- , 2016, DOI: 10.16118/j.1008-0392.2016.06.021
Abstract: 目的通过分析比较手术前后精神功能紊乱的发生情况,探讨右美托咪定对七氟醚吸入全身麻醉术后恢复质量的影响。方法 择期腹腔镜胃肠手术患者80例,ASA Ⅰ~Ⅱ级,年龄30~65岁,随机分为两组,右美组和对照组,每组40例。右美组在全身麻醉插管后给予右美托咪定负荷剂量0.4μg·kg-1,10min输注完毕,继以0.4μg·kg-1·h-1持续泵注,手术结束前30min停止输注;对照组以相同方法给予0.9%氯化钠注射液。两组麻醉诱导方法相同,术中七氟醚吸入维持。记录两组患者术中的心率和平均动脉压。分别于术前、拔管后30min和术后4d用术后恢复质量量表(PQRS量表)对患者进行评估。结果 两组患者术前的PQRS评分差异无统计学意义(P>0.05)。右美组的苏醒期躁动发生率明显低于对照组(P<0.05)。拔管后30min右美组PQRS量表生理因素评分明显高于对照组(P<0.05)。术后4d右美组PQRS量表认知因素评分明显高于对照组(P<0.05)。结论 右美托咪定可以降低全身麻醉苏醒期躁动的发生率并改善患者的术后认知功能,显著提高七氟醚吸入全身麻醉术后恢复质量。
Objective To evaluate the effect of dexmedetomidine on postoperative recovery quality in patients undergoing sevoflurane inhalation general anesthesia. Methods Eighty ASA Ⅰ or Ⅱ patients aged 30 to 65 undergoing selective laparoscopic gastrointestinal surgery were randomly divided into 2 groups(n=40 each): patients in dexmedetomidine group were given dexmedetomidine after intubation at loading dose of 0.4μg/kg for 10min, then at maintaining dose of 0.4μg/kg/h until 30min before the end of operation; patients in control group were given 0.9% normal saline at the same volume. Anesthesia was maintained by inhalation of seven sevoflurane in two groups. Heart rate and mean arterial pressure during the surgery were recorded. Post-operative Quality Recovery Scale(PQRS) was evaluated before operation, 30min after extubation and at d4 after operation. Results The scores of PQRS before surgery were not different between two groups(P>0.05). The score of physiology of PQRS in dexmedetomidine group was significantly higher 30min after extubation, compared with that in control group(P<0.05). The cognitive score of PQRS in dexmedetomidine group was significantly higher 4d after surgery compared with that in control group(P<0.05). Conclusion Dexmedetomidine can significantly improve postoperative recovery quality and effectively reduce the emergence of agitation in patients undergoing general anesthesia
副溶血弧菌(Vibrio parahaemolyticus)tdh2 基因和鳗弧菌(V. anguillarum)ompU 基因二联 DNA 疫苗制备及其对大菱鲆(Scophthalmus maximus)免疫保护作用
刘瑞,赵明,,陈吉祥
海洋与湖沼 , 2011, DOI: 10.11693/hyhz201104018018
Abstract: 采用基因工程的方法, 将副溶血弧菌的热稳定直接溶血素基因tdh2和鳗弧菌外膜蛋白基因ompU 进行融合, 在大肠杆菌中得到表达, 并利用该融合基因构建二联 DNA 疫苗 pEGFP-N1/tdh2-ompU。用 DNA 疫苗按 10 和 50μg/尾的剂量通过肌肉注射免疫大菱鲆, 对大菱鲆抵抗致病性副溶血弧菌和鳗弧菌的免疫效果进行研究。结果表明, DNA 疫苗免疫的大菱鲆对副溶血弧菌感染的最高保护率为 100%, 对鳗弧菌感染的保护率为 35%。 被免疫的大菱鲆肌肉组织中能检测到融合蛋白表达, 在血清中能检测到较高水平特异性抗体, DNA 疫苗引起的体液免疫反应水平和保护效果与注射剂量有关。
HPLC同时测定山楂提取物中绿原酸和牡荆素鼠李糖苷的含量
何雅,苏娟,,,张卫东
中国中药杂志 , 2012,
Abstract: 目的:采用HPLC建立山楂提取物中绿原酸和牡荆素鼠李糖苷的含量测定方法。方法:SHISEIDOCAPCELLPAKC18色谱柱(4.6mm×250mm,5μm),流动相甲醇(A)、四氢呋喃-乙酸-水(10:2:76,B),梯度洗脱,检测波长330nm,流速1.0mL·min-1,柱温25℃。结果:绿原酸和牡荆素鼠李糖苷分别在1.34~164.8,1.18~148.7mg·L-1线性关系良好;平均加样回收率分别为100.4%,98.83%,RSD1.5%,1.3%。结论:该方法简单、准确、重复性好,可用于测定山楂提取物中绿原酸和牡荆素鼠李糖苷的含量,为山楂提取物及其制剂的质量控制有效的方法。
酸性条件下微波改性活性碳纤维对Pb(II)的吸附
施周,,灵芳,刘可
环境工程学报 , 2015,
Abstract: 采用微波辐照的方法,在混酸条件下对活性碳纤维(ACF)进行改性,制备得到一种改性活性碳纤维(M-ACF).通过小试吸附实验考察了微波功率、溶液pH值对M-ACF吸附Pb(II)的影响.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、电子能谱(EDX)等技术对ACF和M-ACF进行表征.结果表明,M-ACF表面的羧基等酸性含氧官能团增多,纤维长度变短且表面粗糙化.当M-ACF的投加量为10mg、含铅溶液初始浓度为50mg/L、pH为6、吸附时间为24h、吸附温度为308K时,M-ACF对Pb(II)的吸附量高达248.5mg/g.吸附过程符合准二级动力学模型和Langmuir等温吸附模型;热力学参数表明吸附为吸热、自发的过程.
4,5-二硝基咪唑的制备
国臣,,曹端林
含能材料 , 2006,
Abstract: 以咪唑为原料,混酸为硝化剂,通氮气条件下,采用正加法、二次加料的方式:先滴加混酸(发烟硫酸20%和硝酸98%),硝化硫酸咪唑盐;再在反应液中滴加硝酸98%反应,合成出4,5-二硝基咪唑。对第二次反应所用的硝酸(98%)量、反应温度和反应时间进行了试验,得到了较佳的实验条件:第二次硝酸滴加量为1.6mol(咪唑为1mol),反应温度为90~95℃,反应时间为5~5.5h。
不完备系统中基于多粒度的变精度粗糙集方法
,,习贝?
计算机科学 , 2012,
Abstract: 多粒度方法是近年来新兴起的一种数据处理模型。为了使多粒度方法适用于不完备信息系统,借鉴非对称相似关系和可变精度的基本思想,提出了基于多粒度的变精度粗糙集模型,其分别包括乐观和悲观两种不同的形式。对这些模型的基本性质进行了讨论,并在多粒度框架下,将变精度方法与严格包含的方法进行了对比分析,最后通过实例分析,说明了如何在不完备信息系统中根据所提出的多粒度变精度粗糙集模型来获取“或”决策规则。
肉桂醛及其衍生物对木材腐朽菌和霉菌的抑制作用
冬梅,,李淑,袁海舰
- , 2017, DOI: 10.13360/j.issn.2096-1359.2017.01.009
Abstract: 天然存在的肉桂醛具有广谱的抗菌生物活性。为了开发环保、高效的木材防腐防霉剂,通过滤纸片法和处理材室内防腐防霉试验考察了肉桂醛及其3种衍生物对木材的防腐和防霉作用。滤纸片法实验结果表明,肉桂醛对4种供试菌种(即:密粘褶菌、彩绒革盖菌、黑曲霉和桔青霉)均表现出最强的抑菌性能。然而,在密粘褶菌对木材的腐朽试验中,对氯肉桂醛表现出最好的保护性能,在浓度为40 g/L时即达到Ⅰ级耐腐; 肉桂酸表现出优于肉桂醛的保护能力,在浓度为10 g/L时即达到Ⅱ级耐腐,而肉桂醛在20 g/L时方可达到Ⅱ级耐腐。在彩绒革盖菌对木材的腐朽试验中,肉桂醛和肉桂酸在浓度为50 g/L时达到Ⅰ级耐腐。在防霉方面,肉桂醛与对氯肉桂醛对黑曲霉和桔青霉有最好的防霉效果,特别是对于桔青霉,在浓度为68.67 g/L时完全防止了桔青霉的霉变。对于黑曲霉,在同样浓度下,两种化合物处理的木材试样都只是发生了很少的霉变。肉桂醛及其衍生物表现出对木材很好的保护作用,且环境友好,可广泛应用。
Cinnamaldehyde, which naturally exists in the world, has a broad-spectrum antifungal activity. In order to develop an environmentally friendly and effective preservative against wood decay and mould fungi, decay and mold resistant abilities of cinnamaldehyde and its three derivatives were examined by a filter paper disk method and wood block laboratory tests. The result of the filter paper disk method showed that among the four compounds, cinnamaldehyde presented the best antifungal activities against all the four selected fungi, i.e., Gloeophyllum trabeum, Trametes versicolor, Aspergillus niger and Penicillium citrinum. In the decay resistance experiment against Gloeophyllum trabeum, 4-chlorocinnamaldehyde showed the best performance and the treated wood could be ranked as Grade Ⅰ of wood decay resistance at the concentration of 40 g/L. Cinnamic acid presented better decay resistance than cinnamaldehyde, and the treated wood could be ranked as Grade Ⅱ of wood decay resistance at the concentration of 10 g/L. The treated wood could not be ranked as Grade Ⅱ until the cinnamaldehyde concentration was up to 20 g/L. In decay resistance experiments against Trametes versicolor, the wood treated with 50 g/L cinnamaldehyde or cinnamic acid could be ranked as Grade Ⅰ. As for mould resistance, cinnamaldehyde and 4-chlorocinnamaldehyde presented the best performance against Aspergillus niger and Penicillium citrinum, especially the latter mould fungous. Both cinnamaldehyde and 4-chlorocinnamaldehyde prevented the treated wood from the growth of Penicillium citrinum totally at a concentration of 68.67 g/L. As to Aspergillus niger,at the same concentration, both cinnamaldehyde and 4-chlorocinnamaldehyde presented good resistant abilities with little infected area. Cinnamaldehyde and the derivatives showed high decay and mold resistant abilities, and are environmentally friendly. Therefore, they have great application potential in wood preservation
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