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This paper provides a novel application of the multi-criteria decision-making (MCDM) method to the multi-objective optimization problem (MOOP) of creating a two-stage helical gearbox (TSHG) with second-stage double gear sets (SDGSs). The aim of the study is to determine the optimum major design components for enhancing the gearbox efficiency while reducing the gearbox volume. In this work, three primary design parameters are chosen to accomplish this: the gear ratio of the first stage and the coefficients of the wheel face width (CWFW) of the first and second stages. Additionally, the study is conducted with two distinct objectives in mind: the lowest gearbox volume and the maximum gearbox efficiency. Moreover, phase 1 and phase 2, respectively, are the two stages of the MOOP. Phase 2 handles the MOOP to identify the ideal primary design factors as well as the single-objective optimization problem to minimize the difference between the variable levels. Additionally, the Multi-Attributive Ideal–Real Comparative Analysis (MAIRCA) approach is selected to deal with the MOOP. The results of the study are utilized to determine the ideal values for three crucial design parameters in order to create a TSHG with SDGSs. [ABSTRACT FROM AUTHOR]

Background: Diarrheagenic Escherichia coli (DEC) is a group of bacterial pathogens that causes life-threatening diarrhea in children in developing countries. However, there is limited information on the characteristics of DEC isolated from patients in these countries. A detailed genomic analysis of 61 DEC-like isolates from infants with diarrhea was performed to clarify and share the characteristics of DEC prevalent in Vietnam. Principal findings: DEC was classified into 57 strains, including 33 enteroaggregative E. coli (EAEC) (54.1%), 20 enteropathogenic E. coli (EPEC) (32.8%), two enteroinvasive E. coli (EIEC) (3.3%), one enterotoxigenic E. coli (ETEC), and one ETEC/EIEC hybrid (1.6% each), and surprisingly into four Escherichia albertii strains (6.6%). Furthermore, several epidemic DEC clones showed an uncommon combination of pathotypes and serotypes, such as EAEC Og130:Hg27, EAEC OgGp9:Hg18, EAEC OgX13:H27, EPEC OgGp7:Hg16, and E. albertii EAOg1:HgUT. Genomic analysis also revealed the presence of various genes and mutations associated with antibiotic resistance in many isolates. Strains that demonstrate potential resistance to ciprofloxacin and ceftriaxone, drugs recommended for treating childhood diarrhea, accounted for 65.6% and 41%, respectively. Significance: Our finding indicate that the routine use of these antibiotics has selected resistant DECs, resulting in a situation where these drugs do not provide in therapeutic effects for some patients. Bridging this gap requires continuous investigations and information sharing regarding the type and distribution of endemic DEC and E. albertii and their antibiotic resistance in different countries. Author summary: Diarrhea is a leading cause of morbidity and mortality in children under five years of age in developing countries, and diarrheagenic Escherichia coli (DEC) is a group of bacterial pathogens that cause a wide variety of intestinal diseases. To control the epidemic of DECs, it is necessary to understand the characteristics of prevalent strains in each region and propose appropriate treatment methods for them. This study reports detailed genomic analysis results of DEC-like strains isolated from infant diarrhea patients in Vietnam. The results suggested that many of the DECs prevalent in this country are uncommon types, and that Escherichia albertii, an emerging diarrheal pathogen, is the cause of diarrhea. Furthermore, comprehensive genome analysis revealed that these DECs are developing serious drug resistance. We believe that the results of this study will be the basis for improving treatment methods for patients with diarrhea and for tracking the evolution of this pathogenic group. [ABSTRACT FROM AUTHOR]

Background/Aim: Cervical cancer is the second most common malignancy among women in Vietnam, but the country is yet to introduce a national human papillomavirus (HPV) vaccine programme targeted at adolescents. We determined HPV prevalence and HPV vaccine knowledge among female university students in Vietnam. Patients and Methods: We surveyed and screened 1,491 female university students in Hanoi, Hue, and Ho Chi Minh City for their sexual behaviours, HPV knowledge and low- and high-risk HPV infection. Results: The prevalence of any HPV infection and any high-risk HPV infection were 4.2% (95%CI=3.3%- 5.4%) and 3.4% (95%CI=2.5%-4.4%), respectively. Being sexually active [adjusted prevalence ratio (aPR): 6.22; 95%CI=3.4-11.37] and having ever been pregnant (aPR: 4.82; 95%CI=1.93-12.04) were positively associated with high-risk HPV infection. Whilst 60% of participants had heard of HPV vaccine, only 4.6% had received the vaccine. Conclusion: The low HPV prevalence found in university students in Vietnam indicates that they can benefit from HPV vaccination, along with a well-designed HPV health promotion programme. [ABSTRACT FROM AUTHOR]

The present work investigates through molecular dynamics finite element method with Tersoff potential the buckling behavior of boron nitride (BN) armchair and zigzag nanotubes under bending. The critical bending buckling angle, moment, and curvature are studied and discussed with respect to the tube length-diameter ratios from 10 to 50. Effects of a Stone-Wales defect in the middle tube on the bending behavior are also examined. The bending buckling mechanism is governed by the local instabilities and bond breaking in the compressive zone of the tubes. Results are useful for the design of nanocomposites and nano-devices with BN nanotubes. [ABSTRACT FROM AUTHOR]

Isoflavonoids and isoflavonoid glycosides have drawn much attention because of their antioxidant radical-scavenging capacity. Based on computational methods, we now present the antioxidant potential results of genistein (1), biochanin A (2), ambocin (3), and tectorigenin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (4). The optimized structures of the neutral and radical forms have been determined by the DFT-B3LYP method with the 6-311G(d) basis set. From the findings and thermodynamic point of view, the ring B system of isoflavones is considered as an active center in facilitating antioxidant reactions. Antioxidant activities are mostly driven by O-H bond dissociation enthalpy (BDE) following hydrogen atom transfer (HAT) mechanism. Antioxidant ability can be arranged in the following order: compounds (4) > (3) > (2) > (1). Of comprehensive structural analysis, flavonoids with 4′-methylation and 6-methoxylation, especially 7-glycosylation would claim responsibility for antioxidant enhancement. [ABSTRACT FROM AUTHOR]