Coral-like potassium and phosphorous doped graphitic carbon nitride structures with enhanced charge and mass transfer dynamics toward photocatalytic hydrogen peroxide production and microbial disinfection.

This study provided insight on the design of co-doped graphitic carbon nitride (g-C3N4) structures by using potassium dihydrogen phosphate (KH2PO4) as a promising material for the supply of potassium (K) and phosphorus (P) elements. The addition of KH2PO4 to the cyanuric acid-melamine complex (CM) solution stabilized its structure by coordinating potassium ions (K+) in the hexagonal pores and dihydrogen phosphate ions (H2PO4-) in dangling bonds on the edge sites. The resultant supramolecular structure (KP-CM) with a unique skeleton governed the polycondensation process, resulting in K and P co-doped g-C3N4 structures with a distinct coral-like morphology (KP-CN). Employing the KP-CM complex as a precursor could modify the optoelectronic behaviour of the photocatalysts via the synergistic effect of the co-doping process. It could also be beneficial in terms of economic considerations by increasing the catalyst synthesis yield. The resulting g-C3N4 showed a remarkable hydrogen peroxide (H2O2) production rate of 216 µmol L-1h-1 compared to the rate of the pristine sample of 137 µmol L-1h-1. It also exhibited significant photocatalytic antibacterial activity in Escherichia coli (E. coli) disinfection.

Munc18 plays an important role in the regulation of glutamate release during female puberty onset.

Munc18, a mammalian homolog of C. elegans Unc, is essential for neurotransmitter release. The aim of this study was to identify estrogen-dependent expression of Munc18-1 and its role in the regulation of glutamate release for puberty onset. Hypothalamic munc18-1 mRNA levels were significantly increased by estrogen treatment in ovariectomized, immature female rats. During pubertal development, the munc18-1 mRNA levels dramatically increased between the juvenile period and the anestrous phase of puberty. Intracerebroventricular administration of an antisense oligodeoxynucleotide against munc18-1 mRNA significantly decreased glutamate release and delayed the day of puberty onset. These results suggest that Munc18-1, expressed in an estrogen-dependent manner, plays an important role in the onset of female puberty via the regulation of glutamate release.

Characterization and biological activities of humic substances from mumie.

Mumie, a semihard black resin formed by long-term humification, is believed to have therapeutic properties. Although mumie has been used in folk medicine since ancient times, there is little information available concerning the physicochemical properties of its constituents and the mechanisms of its therapeutic efficacy. For this study crude mumie was fractionated into fulvic acid (FA), humic acid (HA), humin, hymatomelanic acid, and two low molecular weight fractions (LMW1 and LMW2). The FA fraction was divided into five subfractions, FA1-FA5. The mumie fractions were characterized by IR, UV-vis, and fluorescence spectroscopy. Total carbohydrate content in the fractions was analyzed using the phenol reaction method. The relative content of polar groups and nonpolar hydrocarbon fragments in the mumie fractions correlated well with solubility in an aqueous medium. Biological characterization was performed using only the FA fractions. FA1 and FA2 enhanced the production of reactive oxygen species (ROS) and nitric oxide in murine peritoneal macrophages, as determined with the use of 2',7'-dichlorofluorescin diacetate and Griess reagent, respectively. The enchancement of ROS and nitric oxide production correlated with the level of total carbohydrates in the fractions. Murine splenic lymphocytes treated with FA1 showed a dose-dependent increase in [(3)H]thymidine uptake. These findings suggest that FA derived from mumie has immunomodulatory activity.