Exogenous melatonin alleviates hemorrhagic shock­induced hepatic ischemic injury in rats by inhibiting the NF­κB/IκBα signaling pathway.

Melatonin (MT) is an indoleamine hormone that can counteract ischemia­induced organ injury through its antioxidant effects. The aim of the present study was to investigate the protective effects of exogenous MT against hemorrhagic shock (HS)­induced hepatic ischemic injury in rats, and the role of the nuclear factor (NF)­κB signaling pathway in this process. A rat model of HS­induced hepatic ischemic injury was established. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), tumor necrosis factor (TNF)­α, interferon (IFN)­Î³, interleukin (IL)­6 and IL­1ß were measured every 6 h, and the 24­h survival rate of the rats was analyzed. All surviving rats were sacrificed after 24 h. Pathological changes in the liver and the hepatocyte apoptosis rate were observed by hematoxylin and eosin staining and TUNEL assay, respectively, and the expression levels of NF­κB p65 and NF­κB inhibitor α (IκBα) were analyzed by reverse transcription­quantitative PCR analysis and western blotting. The results demonstrated that the serum levels of ALT, AST, LDH, GDH, TNF­α, IFN­Î³, IL­6 and IL­1ß gradually increased after HS compared with those in rats subjected to a sham procedure, but this increase was attenuated by MT. Furthermore, the survival rate of the MT group was significantly higher compared with that of the HS group. The degree of pathological hepatic injury, the hepatocyte apoptosis rate, and the hepatic levels of TNF­α, IFN­Î³, IL­6 and IL­1ß were significantly decreased in the MT group compared with the HS group. In addition, the mRNA expression of NF­κB p65 was significantly decreased and the mRNA expression of IκBα was significantly increased in the MT group compared with the sham group. Furthermore, the NF­κB p65 protein levels in the MT group were significantly increased in the cytosol but decreased in the nucleus, and the IκBα protein levels were increased while those of phosphorylated IκBα were decreased compared with those in the HS group. Therefore, it may be inferred that exogenous MT alleviates HS­induced hepatic ischemic injury in rats via the inhibition of NF­κB activation and IκBα phosphorylation.

The characteristics and sources of roadside VOCs in Hong Kong: Effect of the LPG catalytic converter replacement programme.

In order to improve local air quality of Hong Kong, more than 99% taxies and public light buses were changed from diesel to liquefied petroleum gas (LPG) fuel type in the early 2000s. In addition to the catalytic converters wear and tear, it is necessary to control air pollutants emitted from LPG vehicles. Therefore, an LPG catalytic converter replacement programme (CCRP) was fulfilled from October 2013 to April 2014 by the Hong Kong government. Roadside volatile compounds (VOCs) were measured by on-line measurement techniques before and after the programme to evaluate the effectiveness of the LPG CCRP. The mixing ratios of total measured VOCs were found decreased from 69.3 ± 12.6 ppbv to 43.9 ± 6.5 ppbv after the LPG CCRP with the decreasing percentage of 36.7%. In addition, the total mixing ratio of LPG tracers, namely propane, i-butane, and n-butane, accounted for 49% of total measured VOCs before the LPG CCRP and the weighting percentage decreased to 34% after the programme. Moreover, the source apportionment of roadside VOCs also reflects the large decreasing trend of LPG vehicular emissions after the air pollution control measure. Due to the application of PTR-MS on measuring real-time VOCs and oxygenated volatile compounds (OVOCs) in this study, the emission ratios of individual OVOCs were investigated and being utilized to differentiate primary and secondary/biogenic sources of roadside OVOCs in Hong Kong. The findings demonstrate the effectiveness of the intervention programme, and are helpful to further implementation of air pollution control strategies in Hong Kong.

Efficient Synthesis of Sugar Alcohols under Mild Conditions Using a Novel Sugar-Selective Hydrogenation Catalyst Based on Ruthenium Valence Regulation.

Sugar alcohols are the prominent alternatives of sugars in food, medical, and health industries. The ruthenium supported on multiwalled carbon nanotubes (Ru/MWCNTs) catalysts were prepared based on the Ru valence regulation strategy and applied for selective sugar hydrogenation to prepare various sugar alcohols including xylitol, arabinitol, sorbitol, mannitol, and galactitol for the first time, with high selectivity (>99.0%) and yield (>98.0%) under mild conditions (≤110 °C, 3.0 MPa H2 pressure). The hydrogenation reaction of xylose was further optimized and under mild conditions (100 °C, 3.0 MPa H2 pressure, and 500 rpm), which were lower than ever reported for high efficient synthesis of xylitol, 99.8% xylose conversion and 99.0% xylitol yield were achieved after 120 min of reaction.

[Review on label-free optical bio-sensing technology based on whisper-gallery-mode].

Optical biosensors are becoming an important tool for drug research and life science, and the label-free optical biosensor based on whisper-gallery-mode (WGM) is reviewed in the present paper. The WGM-based sensors are categorized into three types according to the microcavity structure. The biosensor using microsphere got extensive research because of high quality factor, and its response to protein, virus, and bacteria had been studied. The models based on single photon resonant state and perturbation theory were established. The biosensor using microdisk was proposed early since it can make use of mature lithography technology; however, the quality factor was increased greatly only after the thermal reflow process was introduced and single molecule measurement was then realized. The biosensor using microring has simpler mode structure and materials such as polymer, silicon nitride and silicon-on-insulator had been used for sensor fabrication. As a 3-dimension expansion, sensor using microtube can combine the optical channel and fluidic channel, which attracting more and more attention.