Carbon-doped flower-like Bi2WO6 decorated carbon nanosphere nanocomposites with enhanced visible light photocatalytic degradation of tetracycline

In search of a recyclable catalyst with synergistic adsorption and photocatalysis, unique composite photocatalysts of flower-like bismuth tungstate (Bi2WO6) and carbon nanospheres (CSs) were composited using a hydrothermal synthesis method (named CSs-Bi2WO6). Notably, based on the high visible light utilization and a reasonable band gap (2.53 eV), CSs-Bi2WO6 have good photocatalytic properties. For example, the composite with an optimized ratio (2% CSs-Bi2WO6) showed good adsorption and photocatalytic performance. Under simulated natural light conditions, the degradation rate of tetracycline (TC) by 2% CSs-Bi2WO6 was 84.6% in 60 min, which is nearly 25% higher than pure Bi2WO6. After five cycles, the observed barely decreased TC degradation rate of 2% CSs-Bi2WO6 confirmed the high cyclability and reproducibility of the photocatalyst. The total organic carbon estimation of the post-degradation reaction medium corresponded to 68.2% mineralization. Furthermore, we determined the photocatalytic reaction path by LC–MS, which confirmed that the composite catalyst could effectively degrade TC molecules into small molecules. It can be concluded that the catalyst has a broad application prospect in the field of wastewater treatment

Blinded by the Light: The Growing Complexity of p53

While the tumor suppressor functions of p53 have long been recognized, the contribution of p53 to numerous other aspects of disease and normal life is only now being appreciated. This burgeoning range of responses to p53 is reflected by an increasing variety of mechanisms through which p53 can function, although the ability to activate transcription remains key to p53's modus operandi. Control of p53's transcriptional activity is crucial for determining which p53 response is activated, a decision we must understand if we are to exploit efficiently the next generation of drugs that selectively activate or inhibit p53

New aspects of melanocortin signaling: a role for PRCP in α-MSH degradation

The role of the central melanocortin system in the regulation of energy metabolism has received much attention during the past decade since gene mutations of key components in melanocortin signaling cause monogenic forms of obesity in animals and humans. In the arcuate nucleus of the hypothalamus the prohormone proopiomelanocortin (POMC) is posttranslationally cleaved to produce α-melanocyte stimulating hormone (α-MSH), a peptide with anorexigenic effects upon activation of the melanocortin receptors (MCRs). α-MSH undergoes extensive post-translational processing and its in vivo activity is short lived due to rapid degradation. The enzymatic process that controls α-MSH inactivation is incompletely understood. Recent evidence suggests that prolyl carboxypeptidase (PRCP) is an enzyme responsible for α-MSH degradation. As for many key melanocortin peptides, gene mutation of PRCP causes a change in the metabolic phenotype of rodents. This review summarizes the current knowledge on the melanocortin system with particular focus on PRCP, a newly discovered component of the melanocortin system