Several epidemiological studies and clinical trials have reported the beneficial effects of green tea, coffee, wine, and curry on human health, with its anti-obesity, anti-cancer, anti-diabetic, and neuroprotective properties. These effects, which have been supported using cell-based and animal studies, are mainly attributed to epigallocatechin gallate found in green tea, chlorogenic acid in coffee, resveratrol in wine, and curcumin in curry. Polyphenols are proposed to function via various mechanisms, the most important of which is related to reactive oxygen species (ROS). These polyphenols exert conflicting dual actions as anti- and pro-oxidants. Their anti-oxidative actions help scavenge ROS and downregulate nuclear factor-κB to produce favorable anti-inflammatory effects. Meanwhile, pro-oxidant actions appear to promote ROS generation leading to the activation of 5′-AMP-activated protein kinase, which modulates different enzymes and factors with health beneficial roles. Currently, it remains unclear how these polyphenols exert either pro- or anti-oxidant effects. Similarly, several human studies showed no beneficial effects of these foods, and, by extension polyphenols, on obesity. These inconsistencies may be attributed to different confounding study factors. Thus, this review provides a state-of-the-art update on these foods and their principal polyphenol components, with an assumption that it prevents obesity.

The study aims to visualize droplet behaviors of emulsified fuel in secondary atomization in a flame stabilized in a laminar counterflow field. To study secondary atomization characteristics in the flame, direct photography of the flame using a color high-speed video camera (7,000 fps) and magnified shadow imaging of spray droplets using a monochrome high-speed video camera (180,064 fps) were used. Frequencies of secondary atomization in the flame were also discussed. As a result, “bright spots,” which were of similar or higher luminosity than the surrounding area were observed by direct photography around the luminous flame of the emulsified fuel, whereas the frequency of occurrence of “bright spots” was almost negligible when n-dodecane was used. Observations indicated that the droplet flame rapidly expanded. This expansion was linked to secondary atomization phenomena such as puffing (i.e., vapor eruption from the droplet surface), partial micro-explosion (i.e., where a large portion of a droplet bursts), and micro-explosion (i.e., where the entire droplet bursts), which were visualized in the flame by magnified shadow imaging. It was suggested that secondary atomization caused rapid evaporation and spread of fuel vapor. The magnified shadow imaging technique provided a clear description of droplet behavior in the flame. Numerous puffing and micro-explosion were observed regardless of the flame emissions. In addition, it was observed that vapor blowout in secondary atomization accelerated droplet velocity, and led to the random movement of spray droplet. It was shown that the frequencies of secondary atomization increased in the downstream region where the luminous flame was formed. Secondary atomization occurred in droplets of various sizes in the downstream region, whereas it occurred in only small droplets in the upstream region where the luminous flame was not formed.

Determining a novel etiology and mechanism of human cancer requires extraction of characteristic mutational signatures derived from chemical substances. This study explored the mutational signatures of N-nitroso bile acid conjugates using Salmonella strains. Exposing S. typhimurium TA1535 to N-nitroso-glycine/taurine bile acid conjugates induced a predominance of C:G to T:A transitions. Two mutational signatures, B1 and B2, were extracted. Signature B1 is associated with N-nitroso-glycine bile acid conjugates, while Signature B2 is linked to N-nitroso-taurine bile acid conjugates. Signature B1 revealed a strong transcribed strand bias with GCC and GCT contexts, and the mutation pattern of N-nitroso-glycine bile acid conjugates in YG7108, which lacks O⁶-methylguanine DNA methyltransferases, matched that of the wild-type strain TA1535, suggesting that O⁶-methyl-deoxyguanosine contributes to mutations in the relevant regions. COSMIC database-based similarity analysis revealed that Signature B1 closely resembled SBS42, which is associated with occupational cholangiocarcinoma caused by overexposure to 1,2-dichlolopropane (1,2-DCP) and/or dichloromethane (DCM). Moreover, the inflammatory response pathway was induced by 1,2-DCP exposure in a human cholangiocyte cell line, and iNOS expression was positive in occupational cholangiocarcinomas. These results suggest that 1,2-DCP triggers an inflammatory response in biliary epithelial cells by upregulating iNOS and N-nitroso-glycine bile acid conjugate production, resulting in cholangiocarcinoma via DNA adduct formation.