Search

After lifting COVID-19 restrictions, pneumonia caused by influenza A virus coinfection with Mycoplasma pneumoniae bacteria emerges as a matter of concern. Only a few reports have recently proposed natural compounds for treating the coinfection of influenza A virus and M. pneumoniae, especially resistant strains. Hence, this study demonstrated in silico investigation of two natural classes (flavan-3-ol and flavanone) that could become future inhibitors for bifunctional neuraminidase and anti-M. pneumoniae. Combining the molecular docking with based-virtual screening strategies for over 900 ligands with neuraminidase protein of oseltamivir-resistant virus strain at H274Y mutation (PDB ID: 3CL0), 03 flavan-3-ols and 46 flavanones interacted with both the active site and the adjacent 430-cavity, and showed lower binding energies than laninamivir (−8.1 kcal/mol). The four most suitable candidates (FL22, FN166, FN316, and ChEMBL1779463) also exhibited potential characteristics for inhibiting M. pneumoniae through some vital targets (30S Ribosome-binding factor A (PDB ID: 1PA4) and immunodominant protein P40/P90 complex (PDB ID: 6TLZ)). Furthermore, the total-synthesis strategy of ChEMBL1779463 was successfully proposed using commercial reagents and modern techniques. Our results will offer potential insights for future methods to identify biflavonoids, especially biflavanone, to simultaneously suppress the resistant strains of influenza A virus and M. pneumoniae.

Finding new neuraminidase (N) inhibitors to improve anti-influenza treatment is necessary because of the high mutation rates of N protein. Over 3,000 flavones/flavonols and their synthesized products from the COCONUT database were performed in silico docking screening with N1-H274Y-oseltamivir protein (PDB ID: 3CL0). Several derivatives containing nitrogen heterocyclic groups or aromatic rings showed higher anti-neuraminidase potential than that of laninamivir. Especially, the linker groups between the flavone aglycone and nitrogen heterocyclic group created the interactions with the triad of arginine residues Arg118-Arg292-Arg371, which suggested these compounds could become bifunctional inhibitors against the influenza virus strains at the sialic acid binding site and the adjacent 430-cavity position through triad of arginine residues binding. ADMET indicators and the synthesis design strategy of the most suitable compound, ethyl 4-{2-[(5-hydroxy-4-oxo-2-phenyl-4H-chromen-7-yl)oxy]acetyl}piperazine-1-carboxylate, were also successfully predicted and it could be a concerned candidate for further wet-lab synthesis, in vivo and clinical study.

Escherichia coli (E. coli) is one of the most common sources of infection in humans and animals. The emergence of E. coli which acquires resistance to various antibiotics has made treatment difficult. Bacteriophages can be considered promising agents to expand the options for the treatment of antibiotic-resistant bacteria. This study describes the isolation and characterization of Escherichia phage KIT06, which can infect E. coli resistant to the quinolone antibiotic nalidixic acid. Phage virions possess an icosahedral head that is 93 ± 8 nm in diameter and a contractile tail (116 ± 12 nm × 13 ± 5 nm). The phage was found to be stable under various thermal and pH conditions. A one-step growth curve showed that the latent time of the phage was 20 min, with a burst size of 28 particles per infected cell. Phage KIT06 infected 7 of 12 E. coli strains. It inhibited the growth of the host bacterium and nalidixic acid-resistant E. coli. The lipopolysaccharide and outer membrane proteins of E. coli, tsx and btuB, are phage receptors. Phage KIT06 is a new species of the genus Tequatrovirus with a genome of 167,059 bp consisting of 264 open reading frames (ORFs) that encode gene products related to morphogenesis, replication, regulation, and host lysis. The lack of genes encoding integrase or excisionase indicated that this phage was lytic. Thus, KIT06 could potentially be used to treat antibiotic-resistant E. coli using phage therapy. However, further studies are essential to understand its use in combination with other antimicrobial agents and its safe use in such applications.

This research aimed to determine the optimal media and temperature conditions for the long-term storage of bacteriophages. In this study, the viability of Salmonella phages in 50% glycerol, 10% sodium chloride-magnesium sulfate (SM) buffer, and 5% dimethyl sulfoxide (DMSO) media at room temperature, 4oC, -20oC, and -80oC for 12 months was determined. In 50% glycerol, at the end of the experiment, no significant difference was found between four temperature conditions on phage density, ranging from 6.20-6.23 log10 PFU/mL (P>0.05). Under 10% SM medium, phage preservation at room temperature provided the optimum density at 6.31 log10 PFU/mL. In addition, phages preserved in a 5% DMSO medium were of similar density values across all temperature treatments. Still, their availability after 12 month-storage (88.0-88.5%) was significantly lower (P

This study partially replaced the clay with sewer sludge (SS) and rice husk (RH-SS) to make fired bricks. The brick samples were examed in terms of shrinkage, water absorption, and compressive strength. Besides, they were analyzed via XRD and metal extraction to determine the heavy metal residuals in the products. The results showed that it was possible to fabricate fired bricks using sewer sludge or rice husk-blended sludge with up to 30% by weight. These brick samples complied with the technical standard for clay brick production, in which the compressive strength was more than 7.5 MPa, water absorption was from 11–16%, and the linear shrinkage was all less than 5%. The rice husk addition helped mitigate the heavy metal residuals in the bricks and leaching liquid, in which all the values were lower than the US-EPA maximum concentration of contaminants for toxicity characteristics. Implications: Previous studies have proved the possibility of mixing sewage sludge from different origins (sewage sludge, river sediment, canal sediment, sewer sediment, etc.) with clay and some wastes to make bricks. In which, mostof the studies used sewage sludge from wastewater treatment plants, very fewdealt with lake/river or sewer sediment. This study shall be the first to study the possibility of employing sewer sediments with the addition of rice husk powder to achieve two targets, including (1) the reuse of biowaste and sludge for brick fabrication and (2) the reduction of heavy metals in final calcined bricks. Different ratios of the rice-husk blended sewer sludge (RH-SS) – clay mixture shall be tested to find the optimized compositions. The results showed that it was possible to fabricate fired bricks using sewer sludge or rice husk-blended sludge with up to 30% by weight, which meant reduce 30% of clay in the brick production. The final products were proved to meet the quality standard in terms of compressive strength (more than 10 MPa), water absorption(from 11–16%), and the linear shrinkage (less than 5%). Larger scale of this study can be an evident to recommend for policy change in the waste reuse in construction field. [ABSTRACT FROM AUTHOR]

This paper explores the current obstacles, contemporary practices, and potential solutions for recovery in Vietnam tourism, based on the views of tour operators after the COVID-19 pandemic. This research utilizes twenty-three semi-structured interviews with senior managers and business leaders from five leading tour operators in Vietnam. The findings of this research highlight that, given the current difficulties in operation, Vietnam tourism enterprises developed various response strategies to help their tourism businesses to survive during the pandemic. This research is among the first attempts aims to extend the literature on the implications of COVID-19 to the tourism industry by reflecting the perceptions of tour operators. Furthermore, findings from this study can assist the tourism businesses by highlighting potential solutions and proposing recommendations for the recovery of tourism after the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Escherichia coli (E. coli) is one of the most common sources of infection in humans and animals. The emergence of E. coli which acquires resistance to various antibiotics has made treatment difficult. Bacteriophages can be considered promising agents to expand the options for the treatment of antibiotic-resistant bacteria. This study describes the isolation and characterization of Escherichia phage KIT06, which can infect E. coli resistant to the quinolone antibiotic nalidixic acid. Phage virions possess an icosahedral head that is 93 ± 8 nm in diameter and a contractile tail (116 ± 12 nm × 13 ± 5 nm). The phage was found to be stable under various thermal and pH conditions. A one-step growth curve showed that the latent time of the phage was 20 min, with a burst size of 28 particles per infected cell. Phage KIT06 infected 7 of 12 E. coli strains. It inhibited the growth of the host bacterium and nalidixic acid-resistant E. coli. The lipopolysaccharide and outer membrane proteins of E. coli, tsx and btuB, are phage receptors. Phage KIT06 is a new species of the genus Tequatrovirus with a genome of 167,059 bp consisting of 264 open reading frames (ORFs) that encode gene products related to morphogenesis, replication, regulation, and host lysis. The lack of genes encoding integrase or excisionase indicated that this phage was lytic. Thus, KIT06 could potentially be used to treat antibiotic-resistant E. coli using phage therapy. However, further studies are essential to understand its use in combination with other antimicrobial agents and its safe use in such applications. [ABSTRACT FROM AUTHOR]

Autonomous navigation and information gathering in challenging environments are demanding since the robot's sensors may be susceptible to non-negligible noise, its localization and mapping may be subject to significant uncertainty and drift, and performing collision-checking or evaluating utility functions using a map often requires high computational costs. We propose a learning-based method to efficiently tackle this problem without relying on a map of the environment or the robot's position. Our method utilizes a Collision Prediction Network (CPN) for predicting the collision scores of a set of action sequences, and an Information gain Prediction Network (IPN) for estimating their associated information gain. Both networks assume access to a) the depth image (CPN) or the depth image and the detection mask from any visual method (IPN), b) the robot's partial state (including its linear velocities, z -axis angular velocity, and roll/pitch angles), and c) a library of action sequences. Specifically, the CPN accounts for the estimation uncertainty of the robot's partial state and the neural network's epistemic uncertainty by using the Unscented Transform and an ensemble of neural networks. The outputs of the networks are combined with a goal vector to identify the next-best-action sequence. Simulation studies demonstrate the method's robustness against noisy robot velocity estimates and depth images, alongside its advantages compared to state-of-the-art methods and baselines in (visually-attentive) navigation tasks. Lastly, multiple real-world experiments are presented, including safe flights at 2.5 m/s in a cluttered corridor, and missions inside a dense forest alongside visually-attentive navigation in industrial and university buildings. [ABSTRACT FROM AUTHOR]

This research evaluates the impact of startup mentoring programs on the intention to start new venture creation of startup projects in central Vietnam. The research data was collected from a survey of 250 mentees participating in mentoring programs organized in provinces in the central region of Vietnam. The results of the research show that the mentoring program has an impact on 5 factors leading to the entrepreneurial intention of mentees in descending order, including: Financial Management Skills, Strategic Thinking, Team Building Skills, Visionary Thinking, and Communication Skills. The research results also show that the mentoring program does not have enough impact on Risk Taking Capabilities to lead to the entrepreneurial intention of mentees. [ABSTRACT FROM AUTHOR]