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Thermal decomposition of the carbon nanotube/SiO2precursor powders

Thermal analysis coupled with mass spectrometry

Journal of Thermal Analysis and Calorimetry
Authors: H. Yu, C. Lu, T. Xi, L. Luo, J. Ning, and C. Xiang

Summary  

TG-DSC-MS (thermogravimetry-differential scanning calorimetry-mass spectrometry) coupling techniques were used to make a simultaneous characterizing study for the thermal decomposition process of the carbon nanotube (CNT)/SiO2precursor powders prepared by rapid sol-gel method. The thermal stability of the CNT and the SiO2pure gel were investigated by TG-DSC. The results showed that the oxidation of CNT began from 530 and combusted at about 678C at the heating rate of 10C min-1in air. Moreover, the faster the heating rate, the higher the temperature of CNT combustion. The appropriate calcinations temperature of the CNT/SiO2precursor powders should be held for 1 h at 500C.

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Abstract

The phase transition of TiN from the NaCl structure to the CsCl structure is investigated by the first-principles plane wave pseudopotential density functional theory method, and the thermodynamic properties of the NaCl structures are obtained through the quasi-harmonic Debye model. It is found that the pressures for transition from the NaCl structure to the CsCl structure are 364.1 GPa (for GGA) and 322.2 (for LDA) from equal enthalpies. The calculated ground state properties such as equilibrium lattice constant, bulk modulus, and its pressure derivative are in good agreement with experimental and theoretical data of others. Moreover, the dependences of the relative volume V/V 0 on the pressure P, the Debye temperature ΘD, and heat capacity C V on the pressure P and temperature T, as well as the variation of the thermal expansion α with temperature and pressure are also successfully obtained.

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Abstract  

The powervs. time curves ofStaphylococcus aureus were determined by using a 2277 Thermal Activity Monitor (Sweden). By means of a new model of microorganism growth, the growth rate constants at different concentrations of ginseng and the minimum concentration were calculated from these curves.

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Abstract  

SBA-15 materials were synthesized through the hydrothermal method. The SBA-15 prepared at the hydrothermal time of 24 h possessed a higher surface area and a good hexagonal structure, so it was used as the catalytic support in this experiment. The base metals (Cu, Co, Ni) coated on SBA-15 were prepared for toluene removal. The results revealed that the catalytic activity of Cu/SBA-15 for toluene removal was about 70% at 250 °C, which was the best among the three catalysts. The modification of Cu/SBA-15 by adding different transition metals (Ce, Co, Ni, Mn) to improve the removal efficiency of toluene and NO was also investigated in this study. The results indicate that the catalytic activity of Mn–Cu/SBA-15 for toluene removal was about 100% at 250 °C. The toluene as a reductant on the removal of NO was also determined. Furthermore, the catalytic activity of Mn–Cu/SBA-15 for NO removal can reach about 70% at 300 °C when toluene is used as reductant.

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Abstract  

The importance of angiogenesis in tumor growth and metastasis has led to develop new imaging tracers to understand angiogenic vasculature. Based on the previous study, we further focused on the tumor molecular imaging application of the novel peptide Arginine-Arginine-Leucine (Tyr-Cys-Gly-Gly-Arg-Arg-Leu-Gly-Gly-Cys, tRRL) in this study. The cytotoxicity of raioiodinated tRRL (131I-tRRL) in HepG2 cells was assessed by tested cell viability using kit. tRRL was conjugated with fluorescein FITC to observe its binding with tumor cells and human aortic endothelial cells (HAEC) in vitro. Whole body SPECT imaging of varied tumors xenograftes was performed after intravenous injection of 131I-tRRL for 24 h in BALB/c nude mice. Compared with negative control PBS, small peptide tRRL was of non-cytotoxicity. 131I-tRRL could lead to significant cytotoxicity on HepG2 cells when the radioactivity was greater than 370 kBq. In vitro binding experiment and cellular uptake results revealed that tRRL could adhere to tumor cells besides tumor derived endothelial cells. In vivo SPECT imaging, 131I-tRRL mainly accumulated in various tumor tissues, including melanoma, liver cancer and lung cancer bearing mice. In breast cancer xenografte imaging, the tumor has no significant radionuclide accumulation at 24 h after injected of 131I-tRRL. Radioiodinated tRRL offers a noninvasive nuclear imaging method for functional molecular imaging of tumors, and may be a promising candidate carrier for tumor targeted therapy.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Jianyong Li, Yunshang Yang, Junxi Liu, Rongcai Zhao, Fenyi Yu, and Runhua Lu

Summary  

[14C]Quincetone was prepared from Ba14CO3 with a radiochemical yield of 21.3%. Ba14CO3, as starting material, was acidified to release 14CO2, which reacted with PhMgBr to [14C]benzoic acid. [14C]Benzoic acid was reduced with LiAlH4 to [14C]benzyl alcohol, and oxidized with CrO3 to [14C]benzaldehyde. In the last reaction, [14C]benzaldehyde was condensed with 3-methyl-2-acetyl-quinoxaline-1,4-dioxide to [14C]quincetone. The specific radioactivity of the labeled product was 7.76 mCi/mmol and its radiochemical purity was >97%.

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Cereal Research Communications
Authors: Hongxiang M, Jinbao Yao, Miaoping Zhou, Xu Zhang, Lijuan Ren, Giuhong Yu, and Weizhong Lu

Wheat Fusarium head blight (FHB) may cause serious losses in grain yield and quality in China. More than 7 million hectares which approximately accounts for 25% of the total areas in China is infected by the disease. The cultivation of wheat varieties with resistance to Fusarium head blight is recognized as one of the most important components to diminish losses due to this disease. Chinese wheat breeders have commenced the research on FHB since 1950s. Wheat cultivars with improved FHB resistance were developed through conventional breeding. Some famous resistant varieties such as Sumai 3, Yangmai 158 and Ning 7840 were released from Jiangsu Academy of Agricultural Sciences, these varieties were widely applied in wheat production and breeding programs. Significant achievements concerning molecular mapping and marker assisted selection have been made in the past decade. The major QTL on chromosome 3BS was identified and located in the same region on chromosome 3BS in Sumai 3, Ning 894037, Wangshuibai, and Chinese Spring. Using SSR marker in this QTL region for assisted selection, some lines with the same resistance to FHB were obtained. New STS markers and SSCP markers were developed and will be tested for the efficiency of MAS. However, further achievements are still hindered by a number of constraints. More FHB resistance genetic resources from landrace in middle to lower reaches of Yangtze River are necessary to be used for improving FHB resistant. The genetic mechanism of the varieties contributing the resistance to improved cultivars is needed to be understood. Development of functional markers for FHB is discussed.

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Journal of Behavioral Addictions
Authors: Lu Li, Dan-Dan Xu, Jing-Xin Chai, Di Wang, Lin Li, Ling Zhang, Li Lu, Chee H. Ng, Gabor S. Ungvari, Song-Li Mei, and Yu-Tao Xiang

Background and aims

Internet addiction disorder (IAD) is common in university students. A number of studies have examined the prevalence of IAD in Chinese university students, but the results have been inconsistent. This is a meta-analysis of the prevalence of IAD and its associated factors in Chinese university students.

Methods

Both English (PubMed, PsycINFO, and Embase) and Chinese (Wan Fang Database and Chinese National Knowledge Infrastructure) databases were systematically and independently searched from their inception until January 16, 2017.

Results

Altogether 70 studies covering 122,454 university students were included in the meta-analysis. Using the random-effects model, the pooled overall prevalence of IAD was 11.3% (95% CI: 10.1%–12.5%). When using the 8-item Young Diagnostic Questionnaire, the 10-item modified Young Diagnostic Questionnaire, the 20-item Internet Addiction Test, and the 26-item Chen Internet Addiction Scale, the pooled prevalence of IAD was 8.4% (95% CI: 6.7%–10.4%), 9.3% (95% CI: 7.6%–11.4%), 11.2% (95% CI: 8.8%–14.3%), and 14.0% (95% CI: 10.6%–18.4%), respectively. Subgroup analyses revealed that the pooled prevalence of IAD was significantly associated with the measurement instrument (Q = 9.41, p = .024). Male gender, higher grade, and urban abode were also significantly associated with IAD. The prevalence of IAD was also higher in eastern and central of China than in its northern and western regions (10.7% vs. 8.1%, Q = 4.90, p = .027).

Conclusions

IAD is common among Chinese university students. Appropriate strategies for the prevention and treatment of IAD in this population need greater attention.

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Abstract  

The power vs. time curves of the promoter bacteria of a nutrient drug were determined by using a 2277 Thermal Activity Monitor (Sweden). A new experimental model of bacterial growth were established. The growth rate constant, heat output and optimum concentration of specific promoter bacterial of nutrient drug were calculated.

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Abstract  

Isoproturon [N'-(p-cumenyl)-N,N-dimethylurea] was synthesized, and the low-temperature heat capacities were measured with a small sample precise automatic adiabatic calorimeter over the temperature range from 78 to 342 K. No thermal anomaly or phase transition was observed in this temperature range. The melting and thermal decomposition behavior of isoproturon was investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The melting point and decomposition temperature of isoproturon were determined to be 152.4 and 239.0C. The molar melting enthalpy, and entropy of isoproturon, ΔH m and ΔS m, were determined to be 21.33 and 50.13 J K-1 mol-1, respectively. The fundamental thermodynamic functions of isoproturon relative to standard reference temperature, 298.15 K, were derived from the heat capacity data.

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