Polyhydroxybutyrate (PHB) production from sugar cane molasses and tap water without sterilization using novel strain, Priestia sp. YH4.

The production cost of biodegradable polymer like polyhydroxybutyrate (PHB) is still higher than that of petroleum-based plastics. A potential solution for reducing its production cost is using a cheap carbon source and avoiding a process of sterilization. In this study, a novel PHB-producing microbial strain, Priestia sp. YH4 was screened from the marine environment using sugarcane molasses as the carbon source without sterilization. Culture conditions, such as carbon, NaCl, temperature, pH, inoculum size, and cultivation time, were optimized for obtaining the highest PHB production by YH4 resulting in 5.94 g/L of dry cell weight (DCW) and 61.7 % of PHB content in the 5 mL culture. In addition, it showed similar PHB production between the cultures with or without sterilization in Marine Broth media. When cultured using only tap water, sugarcane molasses, and NaCl in a 5 L fermenter, 24.8 g/L DCW was produced at 41 h yielding 13.9 g/L PHB. Finally, DSC (Differential Scanning Calorimetry) and GPC (Gel Permeation Chromatography) were used to analyze thermal properties and molecular weights resulting in Tm = 167.2 °C, Tc = 67.3 °C, Mw = 2.85 × 105, Mn = 1.05 × 105, and PDI = 2.7, respectively. Therefore, we showed the feasibility of more economical process for PHB production by finding novel strain, utilizing molasses with minimal media components and avoiding sterilization.

Clinical Utility of the Portable Pressure-Measuring Device for Compression Garment Pressure Measurement on Hypertrophic Scars by Burn Injury during Compression Therapy.

Compression therapy for burn scars can accelerate scar maturation and improve clinical symptoms (pruritus and pain). This study objectively verified the effect of pressure garment therapy in maintaining a therapeutic pressure range for hypertrophic scars. Sixty-five participants (aged 20~70 years) with partial- or full-thickness burns, Vancouver scar scale score of ≥4, and a hypertrophic scar of ≥4 cm × 4 cm were enrolled. Compression pressure was measured weekly using a portable pressure-monitoring device to regulate this pressure at 15~25 mmHg for 2 months. In the control group, the compression garment use duration and all other burn rehabilitation measures were identical except for compression monitoring. No significant difference was noted in the initial evaluations between the two groups (p > 0.05). The improvements in the amount of change in scar thickness (p = 0.03), erythema (p = 0.03), and sebum (p = 0.02) were significantly more in the pressure monitoring group than in the control group. No significant differences were noted in melanin levels, trans-epidermal water loss, or changes measured using the Cutometer® between the two groups. The efficacy of compression garment therapy for burn-related hypertrophic scars can be improved using a pressure-monitoring device to maintain the therapeutic range.

Pd(II)/Ag(I)-Promoted One-Pot Synthesis of Cyclic Ureas from (Hetero)Aromatic Amines and Isocyanates.

A simple and facile one-pot reaction has been developed to afford a diverse range of N,N'-disubstituted benzimidazolones and imidazopyridinones containing two differently substituted N atoms. A cooperative Pd(II)/Ag(I) system promotes the sequential addition/intramolecular C-H amidation reaction of (hetero)aromatic amines and isocyanates, leading to the formation of two C-N bonds. A mechanism involving radical intermediates generated by single-electron transfer (SET) in the presence of a Ag2CO3 oxidant and Pd(OAc)2 Lewis acid is proposed. This protocol offers an operationally easy, simple, and robust approach with the use of readily available starting materials, good functional group tolerance, and high efficiency.