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261.
Hongqiang Qu Weihong Wu Hongjuan Wu Jixing Xie Jianzhong Xu 《Journal of Thermal Analysis and Calorimetry》2011,103(3):935-942
The effect of three flame retardants, K2CO3, Na2SiO3·9H2O, and Na2B4O7·10H2O on the process and composition of volatile products of the thermal degradation of wood has been investigated by the thermogravimetric
(TG), differential thermogravimetry (DTG), differential thermal analysis (DTA), and the synchronous thermogravimetry–mass
spectrometry (TG–MS) analysis methods. The results showed that the ion current intensity and ion peak area of m/z = 18 and 44 MS signals were increased by the flame retardants but the ion peak area of m/z = 28 MS signal was decreased (except K2CO3) at the meantime. What’s more, the ion current intensity and ion peak area of m/z = 60 and 68 MS signals were also decreased (except K2CO3), which mean that Na2B4O7 can significantly enhances the dehydration and inhibits the depolymerization of wood. Although K2CO3 accelerates the dehydration reaction, it cannot inhibit the depolymerization reaction effectively, so the flame retardant
efficiency of K2CO3 is decreased with the higher concentration. The catalysis of dehydration reaction of Na2SiO3 is the worst one. 相似文献
262.
Hongjuan Dong Sau Ha Cheung Yimin Liang Baojiang Wang Rajkumar Ramalingam Ping Wang Hongyan Sun Shuk Han Cheng Yun Wah Lam 《Electrophoresis》2013,34(13):1957-1964
Organelle‐specific cell‐permeable fluorescent dyes are invaluable tools in cell biology as they reveal intracellular dynamics in living cells. Mitrotracker is a family of dyes that strongly label the mitochondrion, a key organelle associated with many crucial cellular functions. Despite the popularity of these dyes, little is known about the molecular mechanism behind their staining specificity. Here, we aimed to identify the protein targets of one member of this dye family, mitotracker red (MTR), by 2DE and MS. MTR bound to cellular proteins covalently, and its fluorescence persisted even after cell lysis, protein solubilization, denaturation, and electrophoresis. This enabled us to display MTR‐labeled proteins by 2DE. The MTR‐specific fluorescent signals on the gel revealed the spots that contained MTR‐conjugated proteins. These spots were analyzed by MS, resulting into the identification of ten proteins. We discovered that one major target is the mitochondrial protein HSP60 and that MTR staining could induce production of HSP60, predisposing cells to heat shock‐like responses. The identification of the molecular targets of biological dyes, or “stainomics,” can help correlate their intracellular staining properties with biochemical affinities. We believe this approach can be applied to a wide range of fluorescent probes. 相似文献
263.
A novel temperature-controlled one-pot synthesis of substituted pyridine derivatives via [5C + 1N] annulation of 1,1-bisalkylthio-1,4-pentanedienes and ammonium acetate is developed, and possible mechanisms leading to the divergent formation of the two types of pyridines are discussed. 相似文献
264.
Single-walled carbon nanotubes (SWCNTs) were treated with sulfuric acid at 300 °C to synthesize sulfonated SWCNTs (s-SWCNTs), which were characterized by electron microscopy, infrared, Raman and X-ray photoelectron spectroscopy, and thermo analysis. Compared with activated carbon, more sulfonic acid groups can be introduced onto the surfaces of SWCNTs. The high degree (∼20 wt%) of surface sulfonation led to hydrophilic sidewalls that allows the SWCNTs to be uniformly dispersed in water and organic solvents. The high surface acidity of s-SWCNTs was demonstrated by NH3 temperature-programmed desorption technique and tested by an acetic acid esterification reaction catalyzed by s-SWCNTs. The results show that the water-dispersive s-SWCNTs are an excellent solid acid catalyst and demonstrate the potential of SWCNTs in catalysis applications. 相似文献
265.
In the presence of carbon tetrabromide, a variety of dithiocarbamates, xanthates, dithioesters, and thioethers were prepared in one pot by reacting the corresponding dithioic acids or thiols with active methylene compounds/indole derivatives under mild conditions. The formation of a sulfenyl bromide intermediate is proposed as the key step, which initiates the C-S bond formation. 相似文献
266.
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268.
Hongjuan Wang Huan Chen Yaning Fu Min Liu Jingni Zhang Shulei Han Yushan Tian Hongwei Hou Qingyuan Hu 《Molecules (Basel, Switzerland)》2022,27(12)
Cardiovascular and respiratory diseases, and several cancers resulting from tobacco smoking, are initially characterized by chronic systemic inflammation. Cytokine imbalances can result in inflammation, making it important to understand the pathological mechanisms behind cytokine production. In this study, we collected blood samples from 78 healthy male volunteers, including non-smokers (n = 30), current smokers (n = 30), and ex-smokers (n = 18), and utilized the liquid suspension chip technique to investigate and compare the expression levels of 17 cytokines and chemokines in the human serum of these volunteers. The results demonstrated that the expression levels of CXCL9/MIG and sIL-6R significantly increased after smoking, and continued to increase after quitting smoking. The expression levels of TARC, ITAC, and sVEGFR-3 increased after smoking but decreased after quitting smoking; the expression level of SAA significantly decreased after smoking and showed an upward trend after quitting smoking. Seven cytokines (IL-1β, BCA-1, TNF-α, CRP, ENA-78, MDC, and TNFRII) did not vary between the three groups, while four cytokines (IL-1α, IL-6, IL-8, and SCF) were not detected in any serum sample. In conclusion, this study assessed the physiological production of cytokines and chemokines, highlighting the differences in each due to smoking status. Our results could help evaluate the early development of smoking-related chronic diseases and cancers. 相似文献
269.