Detecting the boundaries of geologic structures is one of the main tasks in interpreting gravity anomalies. Many methods based on the derivatives of gravity anomalies have been introduced to map the ...source boundaries. The drawbacks of traditional methods are that the estimated boundaries are divergent or false boundaries appear in the output map. Here, we use the exponential transform of the tilt angle of the horizontal gradient to improve the edge detection results. The robustness of the presented method is illustrated using synthetic data and real examples from the Voisey’s Bay Ni-Cu-Co deposit (Canada) and the Tuan Giao (Vietnam). The findings show that the presented technique can produce more precise and clear boundaries.
The colloidal silver solution was synthesized by reducing silver nitrate () using sodium borohydride () and starch as a stabilizer agent. The size and optical properties of synthesized AgNPs were ...characterized by UV-Vis spectroscopy, Fourier transform-infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The effects of several parameters on AgNPs were also investigated. The results have shown that the size of synthesized spherical silver nanoparticles was and disperse in water. The synthesized AgNPs of his study exhibited a strong antibacterial activity against Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). The average zones of inhibition of AgNPs were of 7.7 mm for bacteria E. coli and 7.0 mm for S. aureus. In this study, the zone of inhibition of AgNPs was also compared to the reference antibiotics drug.
In this work, pure, large Br-doped SnSe2 single crystals were successfully synthesized using the temperature gradient technique. Br acts as a donor, resulting in electron concentrations up to ∼6.83 × ...1019 cm–3 at room temperature. All samples exhibited metal-like electrical resistivities and Seebeck coefficient behaviors over a temperature range of 300–673 K. Br doping greatly improved the power factor, especially along the in-plane direction. We observed anisotropy in the electrical conductivity, Seebeck coefficient, and, most notably, thermal conductivity. An ultralow thermal conductivity was achieved along the out-of-plane direction, leading to a maximum ZTc of 0.54 at 673 K in the Br-doped sample, which is twice as large as that of the in-plane direction, ZTa = 0.25.
Excess female births (lower sex ratio at birth) associated with paternal exposure to 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) have been reported in Italy. However, no significant effects of maternal ...TCDD exposure on the sex ratio were reported. We investigated the effects of maternal TCDD exposure and the toxic equivalent quantity of polychlorinated dibenzo-p-dioxins/dibenzofurans (TEQ-PCDD/Fs) on the sex ratio at birth in 576 Vietnamese infants from three birth cohorts. TCDD and TEQ-PCDD/Fs in breast milk were stratified (low, mild, moderate, and high) as maternal exposure markers. Logistic regression analysis was used to investigate associations between female birth and dioxin exposure groups after adjusting for confounders. In sprayed and unsprayed areas, adjusted odds ratios (ORs) of female birth (reference: low-TCDD group) were 2.11 in the moderate-TCDD group and 2.77 in the high-TCDD group, which were significantly associated with increased TCDD exposure. In sprayed areas, a significantly increased OR in the high-TCDD group was observed. No significant associations, however, were found between having a girl and TEQ-PCDD/F levels. These results suggest that maternal TCDD exposure may alter the sex ratio at birth among Vietnamese residents of areas with high dioxin contamination.
Metabolite monitoring and response predictors to azathioprine (AZA) in pediatric inflammatory bowel disease (IBD) are debatable. In an attempt to optimize thiopurine therapy and understand the ...mechanism of action of thiopurines, we correlated metabolites and other factors with AZA efficacy in children with IBD.
Data from 86 children with IBD with 440 metabolite measurements were retrospectively analyzed using multilevel logistic regression analyses. A therapeutic response was defined as a pediatric Crohn's disease activity index ≤10 for Crohn's disease or a pediatric ulcerative colitis activity index ≤10 for ulcerative colitis without any treatment with steroids, antitumor necrosis factor, other immunomodulators, or exclusive enteral nutrition.
The 6-thioguanine nucleotide levels >250 pmol per 8 × 10 red blood cells correlated with a higher response (odds ratio, 4.14; 95% confidence interval, 1.49-11.46, P = 0.007), whereas 6-methyl-mercaptopurine and 6-methyl-mercaptopurine:6-thioguanine nucleotide ratio showed no correlation. Other novel response predictors in children with IBD were relative leukopenia (odds ratio, 14.01; 95% confidence interval, 3.77-52.10; P < 0.001) and the absence of lymphopenia (odds ratio, 3.71; 95% confidence interval, 1.26-10.89; P = 0.017). Lower thiopurine methyltransferase activity (P = 0.015), lower platelet count (P = 0.020), and higher aspartate aminotransferase level (P = 0.009) also predicted therapeutic response. Age, gender, patient adherence, the duration of AZA therapy, IBD type, erythrocyte count, and erythrocyte sedimentation rate did not predict efficacy. The high interindividual variability accounting for 57.7% of variance in therapeutic response was observed.
The significant 6-thioguanine nucleotide level-response relationship may support metabolite monitoring to improve thiopurine efficacy in pediatric IBD. The reported response predictors may be helpful for treatment optimization in AZA-treated children with IBD, but should be proved in prospective studies.
The development of a highly efficient CO‐selective adsorbent with high CO adsorption and selectivity is a challenging task. In this work, a novel adsorbent CuCl@MIL‐101(Cr)‐NH2 Cu(I)@MIL‐101(Cr)‐NH2 ...with varied Cu(I) loads was fabricated for CO adsorption. An equimolar mixture of CuCl2 and Cu(HCOO)2 was first impregnated into MIL‐101(Cr)‐NH2 host, followed by reduction at a low temperature of 150 oC. The obtained material was characterized by XRD, FT‐IR, XPS, FE‐SEM, TGA, and N2 sorption methods. CO adsorption experiments revealed that the Cu(I)@MIL‐101(Cr)‐NH2 showed considerably improved CO‐adsorbing capacity owing to the formation of π‐complex between Cu+ and CO. At 25 oC and 100 kPa, the prepared adsorbent contained 30 wt% of CuCl exhibited a maximum CO uptake capacity of ~2.40 mmol.g‐1, exceeding many other Cu(I)‐containing adsorbents that used conventional host materials, such as CuCl/γ‐Al2O3, CuCl/MCM‐41, CuZSM‐5, Cu(I)‐loaded porous organic polymer, CuCl/AlOOH, and CuCl@γ‐Al2O3. Furthermore, Cu(I)@MIL‐101(Cr)‐NH2 exhibited a higher isosteric heat of CO adsorption than MIL101(Cr)‐NH2. The findings suggest that incorporating Cu(I) into metal‐organic frameworks could be a promising strategy for developing CO‐selective materials.
Transport in the cities of Vietnam in general and in Hai Phong city in particular is changing rapidly due to economic growth, urbanization and motorization, problems such as traffic congestion, ...traffic accidents, air pollution and difficulty in accessing city services. In the development plan of the city, the residential, educational, industrial and service industry functions of the city will be distributed and gradually moved from central area to the satellite towns. However, the development of these new satellite towns has not necessarily been proceeding smoothly. One of the causes for the late development of the satellite towns is the poor public transport network and lacking connect the satellite towns with the central area. In addition, recent studies showed that public transport with only bus system is not adequately attented during operation process. The curent bus system only meets less 2% of the city's travel needs. The city needs to develop an advanced public transport system that is enough attractive and environmentally friendly to attract people to use. At the same time, contribute to reducing traffic jams and traffic accidents and in doing so promote metropolitan regions.The paper presents an analysis of current public transportation situations in Vietnam, and to focus on the case study in Haiphong city. Then, the study presents opportunities, challenges and how to develop of A Bus Rapid Transit System (BRT) for Haiphong city and for the cities of Vietnam in general.
To clarify the influence of dioxin exposure on brain morphometry, the present study investigated associations between dioxin exposure at high levels and brain structural irregularities in 32 ...Vietnamese men. Two exposure markers were used: blood dioxin levels, as a marker of exposure in adulthood, and perinatal dioxin exposure, estimated by maternal residency in a dioxin-contaminated area during pregnancy. All subjects underwent brain magnetic resonance imaging (MRI) scans. We analyzed correlations between regional gray matter volumes and blood dioxin levels, and compared regional volumes between men with and without perinatal dioxin exposure using the voxel-based morphometry (VBM) tool from Statistical Parametric Mapping 12 (SPM12). Blood 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was associated with low volume of the medial temporal pole and fusiform gyrus. Toxic equivalency (TEQ)-PCDDs were correlated with low medial temporal pole volume. However, 1,2,3,4,7,8-HxCDD was associated with high middle frontal gyrus and cerebellum volume. In men with perinatal dioxin exposure, the left inferior frontal gyrus pars orbitalis volume was significantly lower than in those without perinatal exposure. These results suggest that dioxin exposure during the perinatal period and in adulthood may alter regional brain volume, which might lead to cognitive deficits and unusual social emotional behavior in Vietnamese men living in dioxin-contaminated areas.
This study reports that children exposed to 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), the major toxin in Agent Orange, from the breast milk of mothers residing near the former Da Nang US air base ...in Vietnam may have specific alterations in higher brain functions, resulting in social and communication deficits, including autism spectrum disorder (ASD). After the age of 8 years, girls with high TCDD showed increased attention deficit hyperactivity disorder (ADHD)-like behaviors and altered mirror neuron activity, which is often observed in children with ASD. However, no significant relationship between autistic traits and toxic equivalency values of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (TEQ-PCDD/Fs) was found in these children. Notably, boys with high levels of TEQ-PCDD/Fs showed poor language and motor development in the first 3 years of life, although boys with high TCDD levels did not. However, at 8 years of age, boys with high TCDD showed reading learning difficulties, a neurodevelopmental disorder. These findings suggest that perinatal TCDD exposure impacts social-emotional cognitive functions, leading to sex-specific neurodevelopmental disorders-learning difficulty in boys and ADHD in girls. Future studies with a greater number of children exposed to high levels of TCDD are necessary to estimate the threshold values for neurodevelopmental effects.
PDF
