Conventional drugs used to treat Tuberculosis (TB) are becoming ineffective due to the occurrence of multiple drug resistant strains of tuberculosis (TB). This has made the TB disease a a serious global health dilemma. Hence, there is desperate necessity for the advancement of new drugs. In this work, the chemical reactivity and bioactivity of several analogs ofpyrazinamide (PZA) were investigated. PZA is one of the first-line of drugs used to treat tuberculosis and is a key contributor to shortening the treatment time for the disease. Chemical reactivity descriptors of pyrazinamide (PZA) and its analogs of acetylsalicyclic acid and salicyclic acid were investigated using conceptual density functional theory in water as a solvent at the MN12SX/Def2TZVP level of theory. Results have shown that all PZA analogs have improved their global and local reactivity indeces as compared to pyrazinamide based on its electronegativity, electrodonating power, electroaccepting power, eletrophilicity, global hardness and dual descriptor condensed fukui indexes. Moreover, their pKa values are slightly higher than PZA. In terms of its drug-likeness, all PZA analogs passed the Lipinski's Rule of Five criteria. Furthermore, their bioactivity scores are significantly better than pyrazinamide indicating good reaction to G-Protein Coupled Receptor (GPCR) ligands, kinase inhibitors, ion channel modulators, nuclear receptor ligands, protease inhibitors and other enzyme targets. Overall, the PZA analogs are found to be promising anti-tuberculosis drugs. Based on global and local reactivity descriptors, pKa and bioactivity scores, PZA analog of 5-n-Octanoylsalicylic acid is the most reactive among the PZA analogs tested.
Biodegradable polymers are gaining attention as alternatives to non-biodegradable plastics to address environmental issues. With the rising global demand for plastic products, the development of non-toxic, biodegradable plastics is a significant topic of research. Aliphatic polyester, the most common biodegradable polyester, is notable for its semi-crystalline structure and can be synthesized from fossil fuels, microbial fermentation, and plants. Due to great properties like being lightweight, biodegradable, biocompatible, and non-toxic, aliphatic polyesters are used in packaging, medical, agricultural, wearable devices, sensors, and textile applications. The biodegradation rate, crucial for biodegradable polymers, is discussed in this review as it is influenced by their structural properties and environmental conditions. This review discusses currently available biodegradable polyesters, their emerging applications, and the challenges in their commercialization. As research in this area grows, this review emphasizes the innovation in biodegradable aliphatic polyesters and their role in advancing environmental sustainability.
This study describes the development and validation of Chinese, Malay and Tamil translations of the Positive Mental Health Instrument (PMHI) in a general population sample in Singapore. Translations were performed using two independent forward translations followed by expert panel discussions and tested for content, construct and language appropriateness using focus group discussions. The final translated tools were field-tested among 220 residents per language using self-administered questionnaires comprising the translated PMHI and other validity measures. Missing data, floor and ceiling effects, confirmatory factor analysis (CFA), internal consistency, item response theory differential item functioning (IRT-DIF) and criterion validity were assessed. A total of 10 PMHI-Chinese items, 26 PMHI-Malay items and six response categories and six PMHI-Tamil items were modified based on expert panel and focus group discussions. PMHI had low missing data and showed negative but acceptable skewness (<2) and kurtosis (<7) for all translations, except for the PMHI-Malay "spirituality" subscale (skewness: -2.8; kurtosis: 12.5). CFA showed that all three PMHI translations fulfilled the original six-factor-higher-order structure (RMSEA = 0.05, CFI = 0.962, TLI = 0.96). Cronbach's alpha coefficients for total PMHI were 0.958, 0.954, 0.945 and 0.949 in the overall sample and the Chinese, Malay and Tamil translations, respectively. The three translations of the PMHI showed expected and significant positive (r = 0.116 to 0.663) and negative correlations (r = -0.137 to -0.574) with established measures. The findings show that the Chinese, Malay and Tamil translations of the PMHI have high internal consistency and validity in this multi-ethnic population.
This study aimed to investigate the transport mechanisms of ions during forward-osmosis-driven (FO-driven) dewatering of microalgae using molecular dynamics (MD) simulations. The dynamical and structural properties of ions in FO systems of varying NaCl or MgCl2 draw solution (DS) concentrations were calculated and correlated. Results indicate that FO systems with higher DS concentration caused ions to have lower hydration numbers and higher coordination numbers leading to lower diffusion coefficients. The higher hydration number of Mg2+ ions resulted in significantly lower ionic permeability as compared to Na+ ions at all concentrations (p = 0.002). The simulations also revealed that higher DS concentrations led to higher accumulation of ions in the membrane. This study provides insights on the proper selection of DS for FO systems.