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Distribution Pattern of Metals in Atmospheric Settling Dust along Roads in Kano Metropolis, Nigeria 尼日利亚卡诺市道路大气沉降尘埃中金属的分布模式
Pub Date : 2015-02-10 DOI: 10.1155/2015/739325
O. Okunola, A. Uzairu, S. Uba, C. S. Ezeanyanaso, Y. Alhassan
The sequential extraction of Cd, Cr, Ni, Pb, Cu, and Zn in atmospheric dust particles collected along ten high traffic roads in Kano metropolis was carried out. Analyses of metals in the extracts were done using flame atomic absorption spectrometry (FAAS). The samples analyzed for metals indicated high levels of Cd, Cr, Ni, Pb, Cu, and Zn in the atmospheric dust samples. The sequential extractions that showed significant amount of Cd were associated with and Fe-MnO fractions especially during the dry seasons. For Cr and Ni, their occlusion in crystal lattice of the soil fraction exhibited the highest percentage. Pb in the particulate dust samples is significantly associated with the carbonate bound fraction with range of 8.81–64.69% across the season. The behaviour of Cu is quite different from other metals in that percentage fractions are higher in the organic bound. As for Zn, significant amounts were associated with the residue fractions ranging from 0.96 to 87.50% across the seasons. This study revealed contamination of the particulate dust with Cd and Pb; this implies health risks to human, living or carrying out daily activities along the corridors of these roads.
对卡诺市10条交通繁忙路段收集的大气粉尘中Cd、Cr、Ni、Pb、Cu、Zn进行了序贯提取。采用火焰原子吸收光谱法(FAAS)对提取物中的金属进行了分析。分析的金属样本表明,大气尘埃样本中含有大量的Cd、Cr、Ni、Pb、Cu和Zn。在连续提取中,Cd与Fe-MnO组分存在显著的相关性,特别是在旱季。Cr和Ni在土壤组分晶格中的遮挡率最高。颗粒尘样品中Pb与碳酸盐结合组分呈显著相关性,在8.81 ~ 64.69%之间。铜的行为与其他金属有很大的不同,它在有机界中的百分比分数更高。锌的残留量在0.96 ~ 87.50%之间。本研究揭示了颗粒粉尘中镉和铅的污染;这对沿着这些道路走廊生活或进行日常活动的人的健康构成威胁。
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引用次数: 4
Proficient Procedure for Preparation of Quinoline Derivatives Catalyzed by NbCl5 in Glycerol as Green Solvent 以甘油为绿色溶剂,NbCl5催化制备喹啉衍生物的熟练方法
Pub Date : 2015-01-21 DOI: 10.1155/2015/743094
M. Nasseri, B. Zakerinasab, Sayyede Kamayestani
Quinolines, an important class of potentially bioactive compounds, have been synthesized by treatment of o-aminoaryl ketones and carbonyl compound utilizing niobium (V) chloride (NbCl5) as an available and inexpensive catalyst. The quinoline derivatives were prepared in glycerol, an excellent solvent in terms of environmental impact, with high yields (76–98%) and short reaction times (20–90 min). Not only diketones but also ketones afforded the desired products in good to excellent yields. The reaction time of 2-amino-5-chlorobenzophenone and dicarbonyl compounds was longer than that of 2-aminobenzophenone. The reaction of cyclic diketones took place faster than open chain analogues. These reactions also proceeded with acetophenone derivatives. In these cases the reaction times are longer.
喹啉类化合物是一类重要的具有潜在生物活性的化合物,利用铌(V)氯化(NbCl5)作为一种廉价的催化剂,通过处理邻氨基芳基酮和羰基化合物合成了喹啉类化合物。喹啉衍生物是在环境影响较好的溶剂甘油中制备的,收率高(76-98%),反应时间短(20-90 min)。不仅是二酮类,而且酮类也能以优异的收率得到所需的产物。2-氨基-5-氯苯甲酮与二羰基化合物的反应时间比2-氨基-5-氯苯甲酮长。环二酮的反应速度比开链类似物快。这些反应也在苯乙酮衍生物中进行。在这些情况下,反应时间更长。
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引用次数: 4
Aminated β-Cyclodextrin-Modified-Carboxylated Magnetic Cobalt/Nanocellulose Composite for Tumor-Targeted Gene Delivery 胺化β-环糊精修饰羧化磁性钴/纳米纤维素复合材料用于肿瘤靶向基因递送
Pub Date : 2014-12-31 DOI: 10.1155/2014/184153
T. Anirudhan, S. R. Rejeena
Gene therapy is a new kind of medicine, which uses genes as drugs in order to treat life threatening diseases. In the present work, a nonviral vector, aminated β-cyclodextrin-modified-carboxylated magnetic cobalt/nanocellulose composite (ACDC-Co/NCC), was synthesized for efficient transfection of genes into tumour cells. The synthesized ACDC-Co/NCC was characterized by means of FTIR, XRD, SEM, and ESR techniques. DNA condensing ability of ACDC-Co/NCC was found to be increased with increase in amount of ACDC-Co/NCC and 84.9% of DNA (1.0 μg/mL) inclusion was observed with 6.0 μg/mL of ACDC-Co/NCC. The cytotoxicity of ACDC-Co/NCC was observed to be minimal, even at higher concentration, with respect to the model transfecting agent, poly(ethyleneimine) (PEI). 88.2% of the gene was transfected at high dose of DNA, as indicated by the highest luciferase expression. These results indicated that ACDC-Co/NCC might be a promising candidate for gene delivery with the characteristics of good biocompatibility, potential biodegradability, minimal cytotoxicity, and relatively high gene transfection efficiency.
基因治疗是一种利用基因作为药物来治疗危及生命的疾病的新型医学。在本工作中,合成了一种非病毒载体,胺化β-环糊精修饰羧化磁性钴/纳米纤维素复合物(ACDC-Co/NCC),用于高效转染基因到肿瘤细胞中。采用FTIR、XRD、SEM、ESR等技术对合成的ACDC-Co/NCC进行了表征。随着ACDC-Co/NCC用量的增加,ACDC-Co/NCC的DNA凝聚能力增强,当ACDC-Co/NCC用量为6.0 μg/mL时,DNA包合率为84.9% (1.0 μg/mL)。与模型转染剂聚亚胺(PEI)相比,即使在较高浓度下,ACDC-Co/NCC的细胞毒性也很小。高剂量DNA转染88.2%的基因,荧光素酶表达量最高。这些结果表明,ACDC-Co/NCC具有良好的生物相容性、潜在的生物降解性、最小的细胞毒性和较高的基因转染效率,可能是一种有前景的基因传递候选材料。
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引用次数: 9
Fast Release of Sulfosalicylic Acid from Polymer Implants Consisting of Regenerated Cellulose/γ-Ferric Oxide/Polypyrrole 再生纤维素/γ-氧化铁/聚吡咯聚合物植入体快速释放磺基水杨酸的研究
Pub Date : 2014-12-22 DOI: 10.1155/2014/474268
Nargis A. Chowdhury, J. Robertson, A. Al-Jumaily, M. Ramos
This work presents a comparative study on the rate of drug release from implantable matrices induced by electric and magnetic fields separately for better biomedical applications. The matrices were prepared by coating γ-ferric oxide dispersed regenerated cellulose film by polypyrrole doped with sulfosalicylic acid as an anti-inflammatory drug. The drug release mechanisms were studied under both the electric and the magnetic fields separately in an acetate buffer solution with pH 5.5 and temperature 37°C during a period of 5 hours. The amount of drug released was analysed by UV-Vis spectrophotometry. The mechanism of drug release from the matrices under electric field includes expansion of conductive polymer chain and the electrostatic force between electron and drug. The drug release mechanism from the matrices under magnetic field is based on the fact that the heat produced locally by magnetic particles loosens the polymer (polypyrrole) chain surrounding the particles. As a result, the drugs attached to the polypyrrole chain come out to the release medium. The matrices showed fast release of drug, that is, more than 60% of the loaded drug was released within 1 h, and are ideal for the treatment of illness in an emergency care.
为了更好地应用于生物医学,本文对电场和磁场分别诱导的可植入基质的药物释放速率进行了比较研究。将含有抗炎药磺基水杨酸的聚吡咯包覆在γ-氧化铁分散再生纤维素膜上制备基质。在pH为5.5、温度为37℃的醋酸缓冲溶液中,分别在电场和磁场作用下研究药物的释放机制,持续5小时。紫外-可见分光光度法测定药物释放量。电场作用下药物从基质中释放的机理包括导电聚合物链的膨胀和电子与药物之间的静电力作用。磁场作用下基质的药物释放机制是基于磁性颗粒局部产生的热量使颗粒周围的聚合物(聚吡咯)链松动。因此,附着在聚吡咯链上的药物会释放到释放介质中。该基质具有快速释药的特点,即1 h内释药量可达60%以上,是急诊治疗疾病的理想基质。
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引用次数: 2
Ultrasonic Investigations of Molecular Interaction in Binary Mixtures of Cyclohexanone with Isomers of Butanol 环己酮与丁醇异构体二元混合物中分子相互作用的超声研究
Pub Date : 2014-12-18 DOI: 10.1155/2014/741795
S. Nayeem, M. Kondaiah, K. Sreekanth, D. Rao
Ultrasonic speed, , and density, , have been measured in binary liquid mixtures of cyclohexanone with the isomers of butanol (-butanol, sec-butanol, and tert-butanol) at 308.15 K over the entire range of composition. Molar volume (), adiabatic compressibility (), intermolecular free length (), acoustic impedance (), and their excess/deviation along with have been calculated from the experimental data. These values have been fitted to Redlich-Kister type polynomial equation. Positive values of , , and negative values of , have been observed for all the liquid mixtures indicating the existence of weak interactions between components. Rupture of H-bond or reduction in H-bond strength of isomers of butanol or breaking of the structure of one or both of the components in a solution causes the existence of dispersions in the present investigated binary mixtures. The data obtained from , , and excess partial molar volumes , , reflects the inferences drawn from . Furthermore, FTIR spectra support the conclusions drawn from excess/deviation properties. The measured values of ultrasonic speed for all the investigated mixtures have been compared with the theoretically estimated values using empirical relations such as, Nomoto, Van Dael and Vangeels, Impedance and Rao specific sound speed.
在308.15 K下,在环己酮与丁醇异构体(-丁醇、仲丁醇和叔丁醇)的二元液体混合物中,在整个组成范围内测量了超声波速度和密度。根据实验数据计算了摩尔体积()、绝热压缩率()、分子间自由长度()、声阻抗()及其随时间的偏差/偏差。这些值被拟合到Redlich-Kister型多项式方程中。在所有液体混合物中均观察到正值和负值,表明组分之间存在弱相互作用。丁醇同分异构体的氢键断裂或氢键强度降低,或溶液中一种或两种组分的结构断裂,会导致本研究的二元混合物中存在分散体。得到的数据,和过量偏摩尔体积,反映了从。此外,FTIR光谱支持从过量/偏差特性得出的结论。利用Nomoto、Van Dael和Vangeels、阻抗和Rao比声速等经验关系式,将所研究混合物的超声声速实测值与理论估计值进行了比较。
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引用次数: 17
Kinetics and Thermodynamic Studies of Depolymerization of Nylon Waste by Hydrolysis Reaction 尼龙废料水解解聚动力学与热力学研究
Pub Date : 2014-12-08 DOI: 10.1155/2014/286709
D. Patil, S. V. Madhamshettiwar
Depolymerization reaction of nylon waste was carried out by hydrolysis reaction. Yield of depolymerization products was up to 72.20% for a two-hour reaction time. The products obtained were characterized by melting point and FTIR spectra. The values obtained for dibenzoyl derivative of hexamethylenediamine (DBHMD) agreed with those of the pure substance. Chemical kinetics of this reaction shows that it is a first-order reaction with respect to hexamethylenediamine (HMD) concentration with velocity constant  min−1. The energy of activation and Arrhenius constant obtained by Arrhenius plot were 87.22 KJg−1 and 0.129, respectively. The other thermodynamic parameters such as enthalpy of activation () and entropy of activation () and free energy of activation were 5975.85 J and −270.86 J·K−1·mol−1 and 101.59 KJ·mol−1, respectively.
采用水解法对尼龙废料进行解聚反应。反应时间为2小时,解聚产物收率达72.20%。用熔点和红外光谱对所得产物进行了表征。六亚二胺二苯甲酰衍生物(DBHMD)的测定值与纯物质的测定值一致。化学动力学表明,该反应与六亚二胺(HMD)浓度有关,速度常数为min - 1,为一级反应。Arrhenius图得到的活化能和Arrhenius常数分别为87.22 KJg−1和0.129。活化焓()、活化熵()和活化自由能分别为5975.85 J、- 270.86 J·K−1·mol−1和101.59 KJ·mol−1。
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引用次数: 16
Characterization of Native and Modified Starches by Potentiometric Titration 用电位滴定法表征天然淀粉和改性淀粉
Pub Date : 2014-12-03 DOI: 10.1155/2014/162480
Diana Soto, José Urdaneta, Kelly Pernia
The use of potentiometric titration for the analysis and characterization of native and modified starches is highlighted. The polyelectrolytic behavior of oxidized starches (thermal and thermal-chemical oxidation), a graft copolymer of itaconic acid (IA) onto starch, and starch esters (mono- and diester itaconate) was compared with the behavior of native starch, the homopolymer, and the acid employed as a graft monomer and substituent. Starch esters showed higher percentages of acidity, followed by graft copolymer of itaconic acid and finally oxidized starches. Analytical techniques and synthesis of modified starches were also described.
强调了使用电位滴定法分析和表征天然淀粉和改性淀粉。将衣康酸(IA)与淀粉和淀粉酯(衣康酸单酯和二酯)的接枝共聚物氧化淀粉(热氧化和热化学氧化)的聚电解质行为与天然淀粉、均聚物以及作为接枝单体和取代基的酸的行为进行了比较。淀粉酯的酸度较高,其次是衣康酸接枝共聚物,最后是氧化淀粉。介绍了改性淀粉的分析技术和合成方法。
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引用次数: 12
Methods for Detection of Aflatoxins in Agricultural Food Crops 农业粮食作物中黄曲霉毒素的检测方法
Pub Date : 2014-11-13 DOI: 10.1155/2014/706291
Alex Paul Wacoo, Alex Paul Wacoo, D. Wendiro, P. Vuzi, J. Hawumba
Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus. These fungal species are contaminants of foodstuff as well as feeds and are responsible for aflatoxin contamination of these agro products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds. Determination of aflatoxins concentration in food stuff and feeds is thus very important. However, due to their low concentration in foods and feedstuff, analytical methods for detection and quantification of aflatoxins have to be specific, sensitive, and simple to carry out. Several methods including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectroscopy, enzyme-linked immune-sorbent assay (ELISA), and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods. Each of these methods has advantages and limitations in aflatoxins analysis. This review critically examines each of the methods used for detection of aflatoxins in foodstuff, highlighting the advantages and limitations of each method. Finally, a way forward for overcoming such obstacles is suggested.
黄曲霉毒素是两种真菌主要产生的有毒致癌次生代谢物:黄曲霉和寄生曲霉。这些真菌是食品和饲料的污染物,是造成这些农产品黄曲霉毒素污染的原因。黄曲霉毒素的毒性和效力使其成为主要的健康危害,并造成与加工食品和饲料污染有关的损失。因此,食品和饲料中黄曲霉毒素浓度的测定具有十分重要的意义。然而,由于黄曲霉毒素在食品和饲料中的浓度较低,检测和定量的分析方法必须具有特异性、敏感性和简便易行的特点。包括薄层色谱法(TLC)、高效液相色谱法(HPLC)、质谱法、酶联免疫吸附法(ELISA)和电化学免疫传感器等几种方法,已被描述用于检测和定量食品中的黄曲霉毒素。这些方法在黄曲霉毒素分析中各有优缺点。这篇综述严格审查了用于检测食品中黄曲霉毒素的每种方法,突出了每种方法的优点和局限性。最后,提出了克服这些障碍的前进道路。
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引用次数: 184
Studies on Mechanical, Thermal, and Morphological Properties of Glass Fibre Reinforced Polyoxymethylene Nanocomposite 玻璃纤维增强聚氧亚甲基纳米复合材料的力学、热学和形态性能研究
Pub Date : 2014-11-06 DOI: 10.1155/2014/782618
K. M. Babu, M. Mettilda
Polyoxymethylene is a material which has excellent mechanical properties similar to Nylon-6 filled with 30% GF. 75% POM and 25% glass fibre (POMGF) were blended with nanoclay to increase the tensile and flexural properties. Samples were extruded in twin screw extruder to blend POMGF and (1%, 3%, and 5%) Cloisite 25A nanoclay and specimens were prepared by injection moulding process. The tensile properties, flexural properties, impact strength, and hardness were investigated for the nanocomposites. The fibre pull-outs, fibre matrix adhesion, and cracks in composites were investigated by using scanning electron microscopy. 1% POMGF nanocomposite has low water absorption property. Addition of nanoclay improves the mechanical properties and thermal properties marginally. Improper blending of glass fibre and nanoclay gives low tensile strength and impact strength. SEM image shows the mixing of glass fibre and nanoclay among which 1% POMGF nanocomposite shows better properties compared to others. The thermal stability decreased marginally only with the addition of nanoclay.
聚甲醛是一种具有优异机械性能的材料,类似于尼龙-6,填充30% GF。将75%聚甲醛(POM)和25%玻璃纤维(POMGF)与纳米粘土共混,提高了拉伸和弯曲性能。将POMGF和(1%、3%和5%)Cloisite 25A纳米粘土混合在双螺杆挤出机中挤出样品,并采用注射成型工艺制备样品。研究了纳米复合材料的拉伸性能、弯曲性能、冲击强度和硬度。利用扫描电镜研究了复合材料中纤维的拔出、纤维基体的粘附和裂纹的变化。1% POMGF纳米复合材料具有低吸水性能。纳米粘土的加入略微改善了材料的力学性能和热性能。玻璃纤维与纳米粘土混合不当,导致抗拉强度和冲击强度较低。SEM图像显示,玻璃纤维与纳米粘土混合后,1%的POMGF纳米复合材料性能较好。纳米粘土的加入使其热稳定性略有下降。
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引用次数: 8
Visual Detection and Determination of Melamine Using Synthetic Dyes 合成染料对三聚氰胺的目视检测与测定
Pub Date : 2014-09-25 DOI: 10.1155/2014/457254
R. Narayan, Kirana Devarahosahally Veeranna
We have used spectroscopic technique for the detection of melamine. The effect of melamine on the colour as well as the pH of bromophenol, methyl red and alizarin red dye solutions was examined at different mole ratios. It is found that we observe color transition and the absorption maxima for bromophenol were at 598 nm, while for methyl red, and alizarin red-S dye they are at 520 nm and 423 nm, respectively. We observe an increase in the absorption intensities at 598 nm with increase in the concentration of melamine in bromophenol blue dye. The absorption intensities at 520 nm decreases and new peak at 420 nm emerges in methyl red dye-melamine mixture. While the absorption intensities at 420 nm decreases and 520 nm peak emerges in alizarin red S dye-melamine at higher mole ratios. The results indicate that we can choose the appropriate dye of suitable range to detect the concentration of melamine from 3 to 206 mg dm−3. The results demonstrate possible use of the simple method for the qualitative and quantitative detection of melamine in adulterated food samples.
我们用光谱技术检测三聚氰胺。考察了三聚氰胺在不同摩尔比下对溴酚、甲基红和茜素红染料溶液的颜色和pH值的影响。结果表明,溴酚染料在598 nm处有显色跃迁,甲基红和芹菜素红- s染料分别在520 nm和423 nm处有吸光度最大值。我们观察到随着溴酚蓝染料中三聚氰胺浓度的增加,在598 nm处的吸收强度增加。甲基红染料-三聚氰胺混合物在520 nm处的吸收强度降低,在420 nm处出现新的吸收峰。而在较高的摩尔比下,茜素红S染料在420 nm处的吸收强度降低,并出现520 nm峰。结果表明,在3 ~ 206mg dm−3范围内,可以选择合适的染料检测三聚氰胺的浓度。结果表明,该方法可用于定性和定量检测掺假食品样品中的三聚氰胺。
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引用次数: 4
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Journal of Chemical Technology & Biotechnology
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