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961.
Salaam Saleh Druthiman Reddy Mantheni Manik Pavan Kumar Maheswaram Susan Moreno-Molek Tobili Sam-Yellowe Alan T. Riga 《Journal of Thermal Analysis and Calorimetry》2013,111(3):1707-1716
Malaria affects over 500 million people worldwide leading to 1–2 million deaths each year, the majority of whom are children. Four Plasmodium species cause malaria in humans. To properly diagnose, and correctly treat malarial infections, accurate diagnosis of infection is required. Proper diagnosis of infection will result in a reduction of morbidity, mortality, and of drug resistant parasites. However, the current tests for malaria diagnosis do not efficiently identify the appropriate human and parasite biomarkers associated with disease. Detection of specific inflammatory mediators such as cytokines associated with malaria pathogenesis will aid the determination of disease progression, disease prognosis, and the early diagnosis of malaria infection. In this study, we used dielectric thermal analysis (DETA), thermogravimetric analysis, and differential scanning calorimetry (DSC) to characterize five human cytokines (IL-1α, IL-2, IL-4, IL-6, and IL-10), to demonstrate how their thermoanalytical properties can be investigated for sensor design. Analysis for DETA was performed at a frequency range of 0.1–300,000 Hz. Permittivity and loss factor measurements were used to calculate tan δ values. Peak frequencies were used to determine dielectric signatures for each cytokine. The peak frequencies were different for each cytokine analyzed. In addition, activation energies were frequency dependent for IL-2 but frequency independent for the remaining four cytokines. Cytokines were also examined using DSC which established variance in heat of crystallization and heat of fusion of solvent among the five cytokines. A noticeable differentiation was observed with IL-1α among the other four cytokines when analyzed using trend analysis. Detection of unique dielectric signals will aid development of sensitive dielectric sensors capable of detecting cytokines in various human samples. 相似文献
962.
Jitender Gaur Shilpa Jain Rohit Bhatia Arun Lal Narender Kumar Kaushik 《Journal of Thermal Analysis and Calorimetry》2013,112(2):1137-1143
We demonstrate synthesis of water insoluble, novel copolymer PA1 from condensation of glyoxal dihydrazone and glyoxal dihydrazone bis(dithiocarbamate) monomers having high capacity to remove metal ions from aqueous solution. The presence of a high atomic percentage of nitrogen and sulfur atoms in PA1 leads to strong ligating ability with metal ions. The monomers and the polymer have been characterized by FTIR, UV–Visible spectroscopy, CHNS elemental analysis, NMR, MALDI-MS, and TG/DTA. As a proof of concept, the PA1 is tested for its ability to remove heavy metal ions Cu2+, Co2+, Fe2+, Ni2+, Mn2+, and CrO 7 2? from aqueous solutions. PA1 efficiently removed metals ions from the metal solutions. The highest absorption ability has been observed toward the iron salts where 0.969 g metal salt is absorbed by 1 g polymer. This study has implication for inexpensive and efficient polymer for purification of water. 相似文献
963.
Pranav Kumar Gutch Sharma Jitendra Shrivastava Alankar Jain Anurekha K. Ganesan 《Journal of Thermal Analysis and Calorimetry》2013,111(3):1953-1958
Pralidoxime chloride known as 2-PAM chloride is used as antidote for nerve agent’s poisoning. This study was undertaken to establish the compatibility of 2-PAM chloride with a number of commonly used excipients by using thermoanalytical technique viz., differential scanning calorimetry (DSC) and thermogravimetry/differential thermogravimetry (TG/DTG) used in pharmaceutical formulation. The TG and DSC both results demonstrated that polyvinyl alcohol, polyacrylamide, microcrestline cellulose, hydroxypropyl cellulose, cellulose acetate, ethyl cellulose found to be compatible with 2-PAM chloride and chosen for the preparation of antidote against chemical warfare agents. 相似文献
964.
Mohammad Hossein Habibi Amir Hossein Habibi 《Journal of Thermal Analysis and Calorimetry》2013,113(2):843-847
Zinc ferrite nanocomposite was synthesized via thermal decomposition of zinc acetate and iron nitrate at three different temperatures (350, 450, and 550 °C). The influence of the thermal decomposition of precursors on the formation zinc ferrites was studied by differential thermal gravimetry and thermogravimetry (TG). The TG curve shows two steps for the thermal decomposition with mass loss of 17.3 % at 78 °C and 63.3 % at 315 °C. The prepared zinc ferrites nanocomposite was characterized by X-ray diffraction and scanning electron microscopy. The X-ray diffractograms of ZnFe2O4 shows that a crystalline phase, spinel system is formed. SEM micrograph of the zinc ferrite nanocomposite indicates the formation of uniformly spherical 48-nm nanograins. The properties of the zinc ferrite phase were strongly dependent on their calcinations temperature and molar ratio of precursors. 相似文献
965.
Shadpour Mallakpour Mohammad Dinari 《Journal of Thermal Analysis and Calorimetry》2013,114(1):329-337
Considering the importance of the nanocomposites, the present work focuses on some new hybrid materials prepared by introducing reactive organoclay (OC) into the chiral poly(amide-imide) (PAI) matrix. At first, Cloisite Na+ was modified with protonated l-isoleucine amino acid. Then, PAI containing phenylalanine was synthesized via solution polycondensation of chiral diacid chloride with 4,4′-diaminodiphenylsulfone and was characterized with Fourier transform infrared (FTIR) and 1H NMR techniques. At last, PAI/OC nanocomposite films containing 2, 5, 10, and 15 % of OC were prepared via solution intercalation method. The effect of OC dispersion and the interaction between OC and polymer chains on the properties of nanocomposites were investigated using FTIR, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, tensile testing of thin films, and thermogravimetry analysis techniques. The thermal stability of hybrids such as the decomposition temperature and mass residue at 800 °C was improved. Mechanical data indicated improvement in the tensile strength of the nanocomposites with OC loading up to 10 wt%. The transparency of the hybrid films was investigated by means of UV–Vis spectra. 相似文献
966.
Pitchiah Esakki Karthik Chinnaiah Jeyabharathi Shanmugam Senthil Kumar Kanala Lakshmi Narasimha Phani 《Journal of Solid State Electrochemistry》2013,17(12):3055-3061
It is shown that the gold surface is catalytically deactivated and smoothened upon removal of the Prussian blue (PB)–gold nanocomposite formed on the gold surface. Atomic force microscopy proves surface smoothening after PB removal. The voltammetric responses of Ru(NH3)6Cl3 on the smoothened surface remain unaffected, but the reactions that involve multistep and inner-sphere electron transfer are affected on the smoothened surface as exemplified by hydroquinone, ferrous oxalate redox reactions, and oxygen reduction. These effects are attributed to catalytic deactivation as a consequence of removal of the active sites. Figure
It is shown that the gold surface is catalytically deactivated and smoothened upon removal of the Prussian blue (PB)–gold nanocomposite formed on the gold surface. Atomic force microscopy proves surface smoothening after PB removal. The voltammetric responses of Ru(NH3)6.Cl3 on smoothened surface remain unaffected, but the reactions that involve multistep and inner-sphere electron transfer are affected on the smoothened surface as exemplified by hydroquinone, ferrous oxalate redox reactions, and oxygen reduction. These effects are attributed to catalytic deactivation as a consequence of removal of the active sites. Graphical abstract shows the Au surface smoothening as a consequence of Prussian blue-gold nanocomposite (Au-PB) formation and removal 相似文献
967.
Mahdi Tohidian Seyed Reza Ghaffarian Seyed Emadodin Shakeri Erfan Dashtimoghadam Mohammad Mahdi Hasani-Sadrabadi 《Journal of Solid State Electrochemistry》2013,17(8):2123-2137
Nanocomposite membranes based on polyelectrolyte complex (PEC) of chitosan/phosphotungstic acid (PWA) and different types of montmorillonite (MMT) were prepared as alternative membranes to Nafion for direct methanol fuel cell (DMFC) applications. Fourier transform infrared spectroscopy (FTIR) revealed an electrostatically fixed PWA within the PEC membranes, which avoids a decrease in proton conductivity at practical condition. Various amounts of pristine as well as organically modified MMT (OMMT) (MMT: Cloisite Na, OMMT: Cloisite 15A, and Cloisite 30B) were introduced to the PEC membranes to decrease in methanol permeability and, thus, enhance efficiency and power density of the cells. X-ray diffraction patterns of the nanocomposite membranes proved that MMT (or OMMT) layers were exfoliated in the membranes at loading weights of lower than 3 wt.%. Moreover, the proton conductivity and the methanol permeability as well as the water uptake behavior of the manufactured nanocomposite membranes were studied. According to the selectivity parameter, ratio of proton conductivity to methanol permeability, the PEC/2 wt.% MMT 30B was identified as the optimum composition. The DMFC performance tests were carried out at 70 °C and 5 M methanol feed and the optimum membrane showed higher maximum power density as well as acceptable durability compared to Nafion 117. The obtained results indicated that owing to the relatively high selectivity and power density, the optimum nanocomposite membrane could be considered as a promising polyelectrolyte membrane (PEM) for DMFC applications. 相似文献
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