52 research outputs found
Characteristics of Simulated Workplace Neutron Standard Fields
This paper presents the development of simulated workplace neutron standard fields at the Institute for Nuclear Science and Technology with the 241Am-Be source moderated by polyethylene spheres with diameters of 15 cm and 30 cm. The characterization of the standard fields (in terms of neutron fluence rates and neutron ambient dose equivalent rates) was performed using Bonner sphere spectrometer system together with MAXED and FRUIT unfolding codes. The related quantities such as neutron dose equivalent-averaged energies and fluence-to-ambient dose equivalent conversion coefficients were also determined. The discrepancies of values are satisfied the standard uncertainty criteria as recommended by the International Standard Organization 12789 series. It implies that the simulated workplace neutron standard fields can be applied in the practical works for calibration purposes
Optimization of Total Flavonoid Extraction From the Helicteres hirsuta Lour. Roots by Bath Ultrasound Assisted method and cytotoxic activities of these Flavonoids
This study was carried out to optimize the various approaches to analyze the effects of various variables on the total flavonoid content extraction from the roots of Helicteres hirsuta L. The existence of various compounds in the methanol fraction was accessed by using LC-MS/MS analysis. The results of the study identified the ideal parameters such as times (30 minutes); methanol solvent concentration (50%); ultrasonic frequency (12 Hz); and material/solvent ratio [1:30 (w/v)] for extracting the highest total flavonoids from the roots of H. Hirsuta. The study's results suggested that the total flavonoid value was 3.52684 (mg Catechin/g extract). The verified experiment obtained an actual value of 5.205 (mg Catechin/g extract). Further, the results of the study suggested the presence of 20 compounds of a flavonoid nature (66.667%) appearing in the purified methanol fractional extract. These compounds can inhibit DPPH free radicals at 50%, with an IC50 value of 536.760 g/mL, and they also have inhibitory activity on the growth of cancer cell lines with IC50 values ranging from 115.81 and 219.17g/mL. The human leukemia cell line (HL-60) exhibits the most significant cytotoxic response to a methanol extract from H. hirsuta root with an IC50 value of 115.81 g/mL
Factors affecting the creativity of high school students
Creativity is a vital personality quality of each individual. Each person has their potential for
creativity, and it can be nurtured and developed in an appropriate and safe environment. The
purpose of the study was to find out which factors from schools and students themselves affect
creativity as well as the association between creativity and age, gender and giftedness of students,
which then a basis to adjust and establish appropriate methods from schools, families, and students
themselves to develop elements and their creativity. The study was conducted on 108 high school
students in three grades from giftedness and non-giftedness schools. The data was collected through
a survey method using a self-constructed questionnaire and drawing creativity test TCT-DP to
determine students' creativity levels and personal information. The study's finding, which uses
mathematical methods and one-way analysis of variance, reveals that factors affecting elements and
creativity level are objective factors including education environment from school; behavior of
teachers, and subjective factors including interests, perspectives, and thoughts of students. It was also
found that there were no significant differences in the components of creativity and creativity among
students in different grades, gender, and groups of giftedness schools
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
NGHIÊN CỨU ĐA DẠNG DI TRUYỀN TẬP ĐOÀN CÁC GIỐNG SẮN (Manihot esculenta Crantz) DỰA VÀO ĐA HÌNH TRÌNH TỰ GEN GBSS1
GBSS1 gene regulates the biosynthesis of starch in cassava, Manihot esculenta Crantz, and its allelic diversity relates to variation in their starch production. In this research, genetic diversity of the recent conserved cassava germplast was estimated based on DNA polymorphism of a targeted fragment on GPSS1 gene of 14 representatives selected from 44 cassava varieties, whose genetic diversity was previously determined with SSR markers. The results from analyses of boostrap values on Neighbor Joining tree, of genetic indice from DNAsp 4.10.9 software, and of typical mutated points of 612bp-fragments on GBSS1 gene of the studied varieties revealed high genetic diversity and were in agreement to previous analyses with SSR markers. All 14 varieties were separated into 3 clusters on Neighbor Joining tree, in accordance with the variation in tuber-starch percentage and fresh root yield between groups. All three groups showed high genetic diversity with 53-99% of bootstrap values, high genetic differentiation (Kst=0.74, χ2=28; P=0.036), high number of allele (A=9) and high allenic diversity (Ad=0.91). The varieties of each group had 2-5 typical alleles. Results of this study could be applied for estimation of effectiveness of cassava germplast conservation. Together with the relevant SSR markers, the typical alleles of GBSS1 gene of different groups could be used as additional markers for selection and breeding of cassava with high starch yield in their tubers. GBSS1 (Granule bound starch synthase 1) là gen điều khiển sinh tổng hợp tinh bột ở cây sắn (Manihot esculenta Crantz) và đa dạng alen của gen phản ánh đa dạng về năng suất và chất lượng tinh bột. Trong nghiên cứu này đa dạng di truyền của tập đoàn giống sắn đang lưu giữ được đánh giá dựa vào đa hình trình tự ADN dọc đoạn đích trên gen GBSS1 của 14 giống đại diện trong 44 giống sắn đã đươc đánh giá bằng chỉ thị SSR. Kết quả phân tích dựa vào giá trị bootstrap trên cây phát sinh chủng loại theo phương pháp Neighbor Joining, dựa vào hệ số di truyền trên phần mềm DNAsp4.10.9 và dựa vào đột biến điểm dọc đoạn đích 612bp trên gen GBSS1 của các giống sắn nghiên cứu đều phản ánh đa dạng di truyền cao và phù hợp với kết quả đánh giá bằng chỉ thị SSR. Các giống sắn được phân thành 3 nhánh tách biệt trên cây phát sinh chủng loại theo tỷ lệ tinh bột và năng suất củ tươi trung bình đặc trưng của từng nhóm. Giữa các nhóm có giá trị bootstrap từ 53-99% và khác biệt di truyền tin cậy (Kst= 0,74, χ2=28; P=0,036) với số lượng alen (A=9) và đa dạng alen (Ad =0,91) cao. Mỗi nhóm sắn có 2-5 alen đặc trưng. Kết quả nghiên cứu có thể áp dụng để đánh giá hiệu quả công tác lưu giữ nguồn gen các giống sắn. Các alen đặc trưng của từng nhóm có thể sử dụng kết hợp với chỉ thị SSR liên quan làm cơ sở để chọn lọc hiệu quả các dòng sắn có tỷ lệ tinh bột cao
Synthesis, crystal structure and Hirshfeld surface analysis of 4-[3-(4-hy-droxy-phen-yl)-4,5-di-hydro-1<i>H</i>-pyrazol-5-yl]-2-meth-oxy-phenol monohydrate.
In the title pyrazoline derivative, C16H16N2O3·H2O, the pyrazoline ring has an envelope conformation with the substituted sp 2 C atom on the flap. The pyrazoline ring makes angles of 86.73 (12) and 13.44 (12)° with the tris-ubstituted and disubstituted benzene rings, respectively. In the crystal structure, the mol-ecules are connected into chains running in the b-axis direction by O-H⋯N hydrogen bonding. Parallel chains inter-act through N-H⋯O hydrogen bonds and π-π stacking of the tris-ubstituted phenyl rings. The major contribution to the surface contacts are H⋯H contacts (44.3%) as concluded from a Hirshfeld surface analysis
Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021
We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions
Iridoid glycosides from Morinda tomentosa and their endoplasmic reticulum stress modulation activity
Three iridoids 1 - 3, asperulosidic acid, daphylloside, and asperuloside, were isolated from the methanol extract of the leaves of Morinda tomentosa. Their chemical structures were elucidated by 1D- and 2D-NMR spectra and in comparison with those reported in the literature. The effects of these compounds on the endoplasmic reticulum stress in XBP1-eGFP-transfected the 293 T cells were measured. Compound 3 significantly reduced the ER-stress both in DMSO-treated and thapsigargin-treated cells. Unlike this compound, compound 3 selectively reduced thapsigargin-induced ER-stress without any effect on the level of XBP1 splicing in DMSO-treated cells. These results suggested that compounds 2 and 3 can be suggested as new ER stress regulators
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