Conformation of the Protein-free Spliceosomal U2-U6 snRNA Complex and Remodeling by Mg2+ and Proteins

Splicing of precursor messenger RNA is an essential process in eukaryotes in which the non-coding regions (introns) are removed and coding regions (exons) ligated together to form a mature mRNA. This process is catalyzed by a multi-mega Dalton ribonucleoprotein complex called the spliceosome, which is assembled from five small nuclear ribonucleoproteins (snRNP) in the form of RNA-protein complexes (U1, U2, U4, U5 and U6) and hundreds of proteins. U2 and U6 small nuclear (sn)RNAs are the only snRNAs directly implicated in catalyzing the splicing of pre-mRNA, but assembly and rearrangement steps prior to catalysis require numerous proteins. Previous studies have shown that the protein-free U2-U6 snRNA complex adopts two conformations in equilibrium, characterized by four and three helices surrounding a central junction. The four-helix conformer is strongly favored in the in vitro protein-free state, but the three-helix conformer predominates in spliceosomes. To analyze the role of the central junction in positioning elements forming the active site, we derived three-dimensional models of the two conformations from distances measured between fluorophores at selected locations in constructs representing the protein-free human U2-U6 snRNA complex by time-resolved fluorescence resonance energy transfer. Data describing four angles in the four-helix conformer suggest tetrahedral geometry; addition of Mg2+ results in shortening of the distances between neighboring helices, indicating compaction of the complex around the junction. In contrast, the three-helix conformer shows a closer approach between helices bearing critical elements, but addition of Mg2+ widens the distance between them and enhances the fraction of the three-helix conformer. Thus, in neither conformer are the critical helices positioned to favor the proposed triplex interaction suggesting the obligation for other components, spliceosomal proteins, to facilitate and stabilize the catalytically active conformation. We showed that incubation with the NineTeen Complex (NTC)-related protein RBM22, which has been implicated in the remodeling of the U2-U6 snRNA complex to render it catalytically active, favors the formation of the three-helix conformer as seen in cryo-EM images of spliceosome. Binding analysis of interaction between yU2-U6 snRNA and a partial homologue of RBM22 in yeast, Cwc2, reveals a specific interaction between them, indicating a specific conformation of the active site stabilized by the protein. These data suggest that although the central junction assumes a significant role in orienting helices, spliceosomal proteins and Mg2+ facilitate formation of the catalytically active conformer

Validating Problem Solving Competency Instrument in the New General Education Curriculum

Problem solving is a crucial skill for students who experience learning and living in the 21st century. To enhance this skill, students need to face a situation setting problem, then students solve the problem. The 2018 general education curriculum has been developed according to the competency approach. As a result, the instructions and assessment system need to be adapted to align with requirements in the new curriculum. The purpose of present study is to develop and validate the problem solving competency (PSC) instrument based on general requirements of this competency in the general education curriculum in Vietnam. The results of Exploratory Factor Analysis (EFA) show that the instruments can be divided into three different components with good factor loadings to measure problem solving competency of Vietnamese students. The instrument is reliable and valid. Reliability analysis using Cronbach’s alpha revealed satisfactory internal consistency for each factor, with values ranging from .670 to .812

EFFECT OF COMMERCIAL WATER REPELLENT AGENTS ON FUNCTIONAL PROPERTIES OF POLYESTER WOVEN FABRIC USED FOR WASHABLE MEDICAL MASKS

Water repellent fabrics are always used for washable medical mask production to keep them from the bacterial liquid during use. Choosing the right water repellent which is efficient and suitable for fabric is important in washable medical mask production. The water-resistant treated fabric needs to keep its water repellent for many washed cycles. Moreover, their physico-mechanical properties such as air permeability and thickness must be less changed. In this study, four commercial water-resistant chemicals (Ruco–Coat BC 7068, TP – Phob FC 2904, Phobotex RHP Hydrophobic Agent, Ruco-guard AFB60) were used to treat the 100% polyester woven fabric to examine the influence of the type and concentration of the waterresistant chemicals on water repellent capability of the polyester woven fabric. The fabric thickness and the air permeability of the untreated and treated fabric were investigated. The SEM, FE-SEM analysis, and the FTIR spectra were used to find the differences between the initial and treated fabric. The results showed that the water-resistant type influenced the water repellent capability of fabrics and their duration. Among four investigated water resistance, the TP – Phob FC 2904 presented the best water resistance for treatment of the 100% polyester woven fabric, and its concentration of 50 g/l has maintained 85 % fabric water repellent capability after 25 washed cycles

INFLUENCE OF SOME WINDING PARAMETERS ON HAIRINESS OF YARN AFTER WINDING PROCESS

Hairiness is an important quality parameter of yarn after winding process. It affects not only the quality of yarn, but also the productivity of the warping, weaving, knitting machines as well as the quality of produced fabrics. Hairiness is influenced by the factors of raw materials, technology and equipment at all stages of yarn production. This article presents the results of experimental research on the simultaneous influence of four typical winding parameters, including: Winding speed (Z1), the load on the friction discs of the yarn tensioner (Z2), the distance between the bobbin and the yarn guide (Z3) and the pressure of package on the grooved drum (Z4) to the increasing percentage of the hairiness of the yarns after winding compared to that before winding. Yarn hairiness was measured by Uster tester 5. By using the second-order orthogonal experimental planning, together with the support of Excel 2019 and Design Expert 11 software, an experimental matrix and mathematical models describing the relationship between the four winding parameters and increasing percentage of the hairiness of three types of yarn (carded Ne 31/1 CVCD, combed Ne 30/1 CVCM, combed Ne 30/1 COCM) are established. The research result is the scientific basis for selecting the optimal winding parameters in order to achieve the required increase in hairiness of the yarn after winding or predict hairiness increase of the yarns before winding

INFLUENCE OF MICROENCAPSULATION PARAMETERS ON THE SIZE AND MORPHOLOGY OF MICROCAPSULES BY ECO-FRIENDLY SOLVENT EVAPORATION METHOD ORIENTED TO MEDICAL TEXTILES

Application of microcapsules in medical textile has been studied and commercially developed widely in recent years. The aim of this work was to propose an eco-friendly microencapsulation by solvent evaporation method that can contribute to the manufacture of medical textile products using microcapsules. Quillaja saponin was used as bio-sourced surfactant and ethyl acetate was used as the less toxic, non-halogenated organic solvent. The influences of saponin concentration, stirring speed during emulsification step and the volume of ethyl acetate used to saturate the aqueous phase before emulsification on the microcapsule size and morphology were investigated. The results showed that eudragit microcapsules of ibuprofen with diameter in range from 17 to 34 µm, which were suitable for medical textile applications, were successfully elaborated. The saponin concentration varied from 0.025 to 0.1 wt%. The stirring speed was changed from 700 to 600 rpm. The volume of ethyl acetate used in saturation step was 0, 8 and 12 ml. In the scope of investigation, the saponin concentration and the volume of ethyl acetate used in saturation step did affect the microcapsule size and morphology while the stirring speed did not. The saturation step really helped to reduce the formation of irregular microparticles and to narrow the size distribution, but the microcapsules became more porous, weaker and were deformed significantly by drying in the fabric treatment process

THE INFLUENCE OF CORE - SHELL RATIO ON CHARACTERISTICS OF MICROCAPSULES CONTAINING CINNAMON ESSENTIAL OIL APPLIED TO AROMATHERAPEUTIC TEXTILES

Microencapsulation is one of the techniques to prepare the functional textiles. In this paper the essential cinnamon oil loaded microcapsules were prepared by solvent evaporation method. In the microencapsulation process, the core - shell ratio was changed by altering the cinnamon oil content in four levels of 0.15, 0.25, 0.35 and 0.45 g while the other components remained unchanged. The microcapsule characteristics including shape and morphology, size and size distribution, microencapsulation efficiency in dependence on the core-shell ratio were investigated. The antimicrobial capacity and the fragrance durability of interlock knitted fabric coated with the elaborated microcapsules were evaluated. The results showed that cinnamon oil was microencapsulated successfully in the spherical microcapsules. When the cinnamon oil content increased, the microcapsule size decreased and the size distribution became broader, the microcapsules were more porous and more aggregate, the fragrance intensity of the fabric treated with microcapsules increased while the activity against E. coli bacteria decreased. According to the results, the microcapsules elaborated with 0.15 g of cinnamon oil was recommended for the treatment of interlock cotton knitted fabric to apply in aroma and antimicrobial textiles

Isolation and genetic characterization of waterfowl parvovirus in ducks in Northern Vietnam

Background and Aim: Short beak and dwarfism syndrome (SBDS), a highly contagious disease, has been reported in duck farms in Vietnam since 2019. In this study, we evaluated the virulence and characterized the virus obtained from SBDS cases in North Vietnam. Materials and Methods: Polymerase chain reaction was used to detect waterfowl parvovirus in ducks, and the virus from positive samples was inoculated into 10-day-old duck-embryonated eggs to reproduce the disease in young ducklings to determine the virulence and subjected to phylogenetic analysis of non-structural (NS) and VP1 gene sequences. Results: Goose parvovirus (GPV) was isolated from ducks associated with SDBS in Vietnam. The virus Han-GPV2001 is highly virulent when inoculated into 10-day-old duck embryos and 3-day-old ducklings. The mortality rate of duck embryos was 94.35% within 6 days of virus inoculation. Inoculating 3-day-old ducks with the virus stock with 104.03 EID50 through intramuscular and neck intravenous administration resulted in 80% and 66.67% of clinical signs of SDBS, respectively, were shown. Phylogenetic analysis based on the partial NS and VP1 gene sequences revealed that the viral isolate obtained in this study belonged to novel GPV (NGPV) and was closely related to previous Vietnamese and Chinese strains. Conclusion: A GPV strain, Han-GPV2001, has been successfully isolated and has virulence in duck-embryonated eggs as well as caused clinical signs of SBDS in ducks. Phylogenetic analyses of partial genes encoding NS and capsid proteins indicated that the obtained GPV isolate belongs to the NGPV group

HMU fluorinze mouthwash enhances enamel remineralization: An in vitro study

BACKGROUND: Fluoride therapy has long been used extensively to prevent dental caries. Fluoride appears in variety of dental care products such as mouthrinse, dentifrice, gel, etc. HMU fluorinze is the first mouthwash containing fluoride in Vietnam. AIM: This research was conducted to evaluate the efficacy of HMU Fluorinze mouthwash on remineralizing enamel in laboratory conditions. METHODS: 20 third molars teeth were cleaned and covered with nail polish , except for a 3x3 mm square on their buccal surfaces. These teeth went through two steps: demineralization using Coke and remineralization for 20 days: 1) using standard calcifying solution (control group) and 2) using standard calcifying solution + HMU Fluorinze mouthwash 2 times/day (experimental group). The mineralization index of enamel structure after demineralization and remineralization was assessed by DIAGNOdent pen 2190. RESULTS: The mineralization indexes of the control group and experimental group at baseline were 3.65 ± 0.76 and 3.35 ± 0.64, after demineralization were in turn of 21.78 ± 4.48 and 20.25 ± 2.26; and after remineralization were 6.30 ± 1.03 and 3.90 ± 1.24. The different figures  between the two groups after remineralization shows statistical significance (p<0.01). Group B using HMU fluorinze mouthwash after 20 days did not differ from the original results (p = 0.272), in contrast with the control group (p<0.01). CONCLUSIONS: HMU fluorinze mouthwash has better mineralization effect than standard calcifying solution

Preimplantation Genetic Testing of Aneuploidy by Next Generation Sequencing: Association of Maternal Age and Chromosomal Abnormalities of Blastocyst

BACKGROUND: Aneuploidy is a major cause of miscarriages and implantation failure. Preimplantation genetic testing for aneuploidy (PGT-A) by Next Generation Sequencing (NGS) is able to detect of the numeral and structural chromosomal abnormalities of embryos in vitro fertilization (IVF). AIM: This study was aimed to assess the relationship between maternal age and chromosomal abnormalities NGS technology. METHODS: 603 human trophectoderm (TE) biopsied samples were tested by Veriseq kit of Illumina. The relation of marternal age and chromosomal abnormality of blastocyst embryo was evaluated. RESULTS: Among the 603 TE samples, 247 samples (42.73%) presented as chromosomal abnormalities. The abnormalities occurred to almost chromosomes, and the most popular aneuploidy observed is 22. Aneuploidy rate from 0.87% in chromosome 11 to 6.06% in chromosome 22. The rate of abnormal chromosome increased dramatically in group of mother's ages over 37 (54.17%) comparing to group of mother's ages less than 37 (38.05%) (p < 0.000). The Abnormal chromosome and maternal age has a positive correlation with r = 0.4783 (p<0.0001). CONCLUSION: These results showed high rate abnormal chromosome and correlated with advanced maternal age of blastocyst embryos

On the Information Problem of DNA in the Denaturation Process

The information problem of DNA in the denaturation process was studied by the relationship between entropy and information. Using the previous PB’s (Peyrard and Bishop) numerical results obtained from their microscopic arharmonic model of DNA, we propose a new effective simple model to calculate DNA information. A shape change of information at the denaturation phase transition point was found and discussed