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Dengue encephalitis is considered as a severe but unusual clinical presentation of dengue infection. Limited molecular information is available on the neurotropism of dengue virus (DENV), highlighting the need for further research. During a dengue outbreak in Vietnam in 2013, two DENV-3 strains were isolated, in which one was isolated from cerebrospinal fluid (CSF) samples from a dengue encephalitis patient and another strain was isolated from a patient with classical dengue fever in Hai Phong, Vietnam. DENV serotype-3 (DENV-3) isolated from these samples belonged to genotype III, marking the first report of this genotype in the country at that time. Genetic variation between both strains was elucidated by using a full genome sequencing by next-generation sequencing (NGS). The infectivity of the isolated DENV-3 strains was further characterized using human and mouse neuronal cell lines. Phylogenetic analysis of the isolates demonstrated high homogeneity between the CSF-derived and serum-derived DENV-3, in which the full genome sequences of the CSF-derived DENV-3 presented a Thr-1339-Ile mutation in the nonstructural 2A (NS2A) protein. The CSF-derived DENV-3 isolate grew preferentially in human neuronal cells, with a significant proportion of cells that were positive for nonstructural 1 (NS1), nonstructural 4B (NS4B), and nonstructural 5 (NS5) antigens. These results suggest that NS2A may be a crucial region in the neuropathogenesis of DENV-3 and its growth in human neuronal cells. Taken together, our results demonstrate that a CSF-derived DENV-3 has unique infectivity characteristics for human neuronal cells, which might play a crucial role in the neuropathogenesis of DENV infection., Canadian Journal of Infectious Diseases and Medical Microbiology, 2023, art. no. 2635383; 2023

Purpose Service quality has been widely recognized as the core value of any higher education institution (HEIs), especially in the context of higher education reform in Vietnam. The paper aims to assess the student’s perceived service quality using SERVPERF scale and to find the relations between perceived service quality, satisfaction and loyalty in one public university in Vietnam. Design/methodology/approach The self-structured questionnaire using SERVPERF scale was administered to 350 students currently attending full-time courses at the university. Confirmatory factor analysis was used to certify the elementary factors. The regression models were applied to determine the relationship between service quality, student satisfaction and student loyalty. Findings The findings revealed the significant relationships between student perceived service quality with satisfaction and loyalty. However, this relationship is mediated by student satisfaction. Research limitations/implications The study is limited to public university education service and examined the perspective of student as “primary customer”; therefore, generalizing the results to other service industries and other role of student as stakeholder or citizen should be used with caution. Practical implications The SERVPERF scale could be delivered regularly to get the student’s perception on the HEIs performance. The results should be taken for purpose of continuing quality improvement to enhance the satisfaction and loyalty, particularly in the context of highly competitive environment and university autonomous in Vietnam. Originality/value This is believed to be the first study in Vietnam with sufficient evidence to support the concept that service quality positively related to students’ satisfaction and loyalty and satisfaction as mediating factor.

Supplemental material, sj-docx-1-npx-10.1177_1934578X221148621 for Two New Nitrogen-Containing Glycosides From Stixis scandens by Tran Thi Yen, Nguyen Thanh Tam, Nguyen Thanh Thi Kim and Vo Ngoc Binh, Nguyen Thao Kim Nu, Ngo Quoc Anh in Natural Product Communications

We revisit a model describing Seebeck effect on a weak link between two charge Kondo circuits, which has been proposed in the [Phys. Rev. B 97, 085403 (2018)]. We calculate the thermoelectric coefficients in the perturbation theory assuming smallness of the reflection amplitudes of the quantum point contacts. We focus on the linear response equations for the heat conductance in three different scenarios as: Fermi liquid vs Fermi liquid, Fermi liquid vs non-Fermi liquid, nonFermi liquid vs non-Fermi liquid. The oscillations of the heat conductance as a function of the gate voltage of each quantum dot are analysed in both Fermi liquid and non-Fermi liquid regimes. We discuss possible experimental realizations of the model to observe the signatures of the non-Fermi liquid behaviour in the heat conductance measurements., Comment: 12 pages, 2 figures

Porcine epidemic diarrhea virus (PEDV) causes diarrhea in pigs leading to severe illnesses and high mortality rates. The development of medicinal agents to treat PEDV infection is therefore crucial. In this study, antiviral activities against PEDV of ethanol and aqueous extracts of 17 Vietnamese traditional medicinal plants were evaluated using the cytopathic effect-based assay. The results showed that 14 out of 17 medicinal plants could inhibit the cytopathic effect of PEDV. The ethanol extract of Stixis scandens was identified as the most active extract with its MIC (minimum inhibitory concentration) being 0.15 μg/mL. Other plant extracts also displayed strong antiviral activity against PEDV, including Anisomeles indica, Pericampylus glaucus and Croton kongensis. The results demonstrate that certain medicinal plants have a high antiviral potential and may serve as a lead to develop novel pharmaceutical agents to cure PED as well as the diseases caused by other coronaviruses.

Breast cancer (BC) is the leading type of cancer among women. Findings have revolutionized current knowledge of microRNA (miRNA) in breast tumorigenesis. The seed region of miRNA regulates the process of gene expression negatively. The presence of SNPs in the seed regions of miRNA dramatically alters the mature miRNA function. Additionally, SNPs in the out-seed region of miRNAs have a significant impact on miRNA targeting. This study focuses on the in silico analysis procedure of mature miRNA SNPs and their impact on BC risk. The database annotated SNPs on mature miRNAs was used. Also, target gene alterations, miRNAs function in BC, and the interaction of miRNAs with targets were predicted. A list of 101 SNPs in 100 miRNAs with functional targets in BC was indicated. Under the SNPs allele variation, 10 miRNAs changed function, 6 miRNAs lost targets, 15 miRNAs gained targets, 48 onco-miRNAs remained unchanged, and 21 tumor suppressor miRNAs remained unchanged. At last, a list of 89 SNPs, which alter miRNA function and miRNA-mRNA interaction, were shown to be potentially associated with BC risk. This research theoretically generated a list of possible causative SNPs in the mature miRNA gene that might be used in future BC management studies.

Species composition, age distribution, and their relationship with land height from the datum line (LH) of the Sonneratia caseolaris stand, which grows in the Lam River estuary in Vietnam, were surveyed to obtain fundamental knowledge that aimed at contributing to mangrove restoration. The data gathered on the sandbar consists of three mangrove species and one mangrove associate species, with one non-mangrove species, and were divided into three communities. In terms of the age distribution of the S. caseolaris–Aegiceras corniculatum community, the tree-phase densities for both species are lower than those exhibited by younger phases. In its succession, the seedlings of S. caseolaris and A. corniculatum are primarily recruited at the mean tide level (MWL) in the early stages. Then, A. corniculatum expands to the lower tide zone primarily on mud flat bare land. For both species, full irradiance on the bare land in the low tide zone below MWL is crucial for growth, but S. caseolaris, which propagates by releasing small seeds, can barely survive in the low tide zone because its seeds are easily flushed away. In contrast, A. corniculatum, which propagates using crypto-viviparous seedlings, has a higher survival rate in the low tide zone. As a result, the LH of seedlings of A. corniculatum distribution is significantly lower than that of the distribution of S. caseolaris trees (p

In Vietnam, fisheries play a key role in the national economy. Helminth infections in fish have a major impact on public health and sustainable fish production. A comprehensive summary of the recent knowledge on fish helminths is important to understand the distribution of parasites in the country, and to design effective control measures. Therefore, a systematic review was conducted, collecting available literature published between January 2004 and October 2020. A total of 108 eligible records were retrieved reporting 268 helminth species, among which are digeneans, monogeneans, cestodes, nematodes and acanthocephalans. Some helminths were identified with zoonotic potential, such as, the heterophyids, opisthorchiids, the nematodes Gnathostoma spinigerum, Anisakis sp. and Capillaria spp. and the cestode Hysterothylacium; and with highly pathogenic potential, such as, the monogeneans of Capsalidae, Diplectanidae and Gyrodactylidae, the nematodes Philometra and Camallanidae, the tapeworm Schyzocotyle acheilognathi, the acanthocephalans Neoechinorhynchus and Acanthocephalus. Overall, these studies only covered about nine percent of the more than 2400 fish species occurring in the waters of Vietnam. Considering the expansion of the aquaculture sector as a part of the national economic development strategy, it is important to expand the research to cover the helminth fauna of all fish species, to assess their potential zoonotic and fish health impacts., Graphical abstract Image 1, Highlights • 268 helminth species were reported in 213 fish species occurring in Vietnam. • Reported zoonotic helminths belonged to digeneans, nematodes and cestodes. • Other species included monogeneans, nematodes, cestodes and acanthocephalans.

Recently, the influence of electron-electron interactions on the thermoelectric transport in a two-channel charge Kondo circuit has been studied in [Phys. Rev. B 105, L121405 (2022)]. In this paper, we revisit the Luttinger-liquid-based model and discuss in details the limit where the spin field is noninteracting (\(g_\sigma = 1\)) and the interaction in the charge sector is repulsive (\(0< g_\rho \leq 1\)). The thermoelectric transport coefficients are computed nonperturbatively with respect to the reflection amplitude at the quantum point contact. At low temperatures the thermopower shows the non-Fermi liquid behavior in the vicinity of the Coulomb peaks. We also demonstrate that repulsive interaction results in the enhancement of the thermoelectrical power.

Purpose This paper aims to explore how research and development (R&D) scientists and engineers can contribute to sustainability initiatives in their organisations. Design/methodology/approach This paper uses a critical case study methodology, focussed on a large Vietnamese company in which business leaders sought to engage R&D scientists and engineers in sustainability initiatives focussed on eco-innovation and eco-efficiency. Bourdieu’s theoretical lens of habitus, capitals and field facilitates a relational analysis of the findings. Findings While R&D scientists and engineers adapted well to early changes aligned with eco-innovation, they struggled to engage with sustainability initiatives in the case firm. This study explains adaptions and constraints as scientists and engineers’ professional habitus and capitals, and their broader organisational field. Practical implications This paper provides insight into how organisations might integrate professional acculturation and appropriate facilitators to promote the additional contribution of scientists and engineers to sustainability initiatives in the context of an organisation. Social implications Although eco-innovation and eco-efficiency are only potential dimensions of comprehensive organisational sustainability reform, this research provides insight into how engaging scientists and engineers with a broader social sustainability agenda might be advanced. Originality/value The study addresses calls for empirical insights into ways that scientists and engineers can commit to organisational sustainability practices based on the configurations of habitus, capital and organisational field.

Breast cancer is the most common cancer for women around the world. The presence of single nucleotide polymorphisms (SNP) on or near the coding region of breast cancer susceptibility genes can affect the regulation of gene expression, which may increase or decrease the risk of breast cancer. BARX2 was showed to stimulate the expression of ERS1, which involved in the development of breast cancer. SNP rs7107217 on 152kb downstream of the BARX2 could affect the level of protein BARX2 and had been proved to associate with the breast cancer risk in populations similar to Vietnamese, including Chinese and Korean. In this study, rs7107217 was genotyped and initially detemined the association with the breast cancer risk in Vietnamese. Real-time PCR HRM was optimized and used to genotype rs7107217 in 117 breast cancer cases and 105 healthy controls. Thereafter, the correlation of this SNP with the risk of breast cancer was initially determined by analyzing the differences in allelic and genotypic frequencies between cases and control groups. The results showed the optimal rs7107217 genotyping condition was successfully developed with the high sensitivity, specificity, and consistency. SNP rs7107217 had high polymorphism with the frequency of minor allele C of 29.9% and 35.3% in case and control, respectively. SNP rs7107217 had been found no association with the breast cancer risk (C vs A: P = 0.23, OR (95% CI) = 0.79 (0.53 – 1.17)). However with the low reliability of the analysis (11.71%) and the high potential related to the formation of breast cancer, the association between rs7107217 and breast cancer risk in Vietnamese population should be further conducted on a larger sample size to get higher accuracy.

MicroRNAs (miRNAs) have been recently described as small noncoding RNAs that are involved in numerous crucial physiological processes, such as cell cycles, differentiation, development, and metabolism. Thus, dysregulation of these molecules could lead to several severe disorders, including breast cancer (BC). Ongoing investigations in malignant growth diagnostics have distinguished miRNAs as promising disease biomarkers. As with any other mRNAs, single nucleotide polymorphisms (SNPs) in DNA sequence encoding for miRNA (miR-SNPs) indeed lead to potential changes in the function of miRNA. In this study, miR-SNPs located in different miRNA sequence regions, which have been associated with BC in different ways, and the potential mechanisms of how these miR-SNPs develop the risk of the disease were discussed.

Breast cancer (BC) is the most common cancer among women and accounts for the highest mortality rates in the developing countries, including Vietnam. D-loop, is a non-coding region in mitochondrialcircular DNA molecules, related to control the replication and transcription of mitochondrial genes. D-loop mutations cause the dysfunction of the respiratory chain, which contributes to the process of BC. SNP rs3937033 (T/C) on D-loop was reported to have the association with BC in Europe America population (OR [95%CI]= 1.98 [1.25–3.12], P=0.036), and Caucasian (OR[95%CI]= 21 [2.15–204.6], P=0.003). In this study, the High Resolution Melting (HRM) method is optimized for genotyping 100/100 cases/controls samples, then to determine the association between the disease and this SNP. TT, TC and CC genotype frequencies in patient group (36 %, 3 % and 61 %) and control group (23 %, 1 % and 76 %) were calculated based on the results of genotyping by optimal HRM method with the annealing temperature is 66 0C. Association analysis result showed that T allele increases the risk of breast cancer patients up to 1.41 times (OR [95% CI] = 1.41 [1.3-1.92], Pallele = 0.03). Therefore, SNP rs3937033 could be a potential biomarker for early BC diagnosis in Vietnamese. However, this research needs to be conducted with a larger sample size to reach the greater confidence.

This paper examines the effects of female chief executive officers (CEOs) on firm performance. Using data on nonfinancial listed firms in Japan, we show that only 0.8% of some 42,000 firm-year observations have female CEOs. There is also little evidence that firms appoint more females as CEOs during our sample period. While the stock market reacts positively to the introduction of a firm's first female CEO, the relationship between CEO gender and firm accounting performance is generally not strong. However, when we classify the type of female CEO, the estimated coefficient for a founder female CEO and Tobin's Q is positive and significant.

In this paper, SnO2 nano particles were loaded on TiO2 nanotubes (SnO2/TNTs) by onestep hydrothermal method with the purpose to enhance the photocatalytic ability of TiO2 nanotubes (TNTs). Structure and morphology of the material were characterized by X-ray diffraction measurement (XRD) and transmission electron microscopy (TEM). SnO2 nano particles onto TNTs prevent the recombination of electronhole pairs at the interface area. This contribution increased the photocatalytic efficiency of the material. The effect of SnO2 contents on the photocatalytic activities of the composite materials was also investigated with methylene blue that is chosen as the pollutant in industry. The results showed that SnO2/TNTs composite materials had been successfully synthesized by one-step hydrothermal method and SnO2/TNTs composite material with 2 % SnO2 content loading possesses the highest photocatalytic efficiency with 70 % after 180 minutes illuminated under sunlight.

Background An opisthorchiid liver fluke was recently reported from ducks (Anas platyrhynchos) in Binh Dinh Province of Central Vietnam, and referred to as “Opisthorchis viverrini-like”. This species uses common cyprinoid fishes as second intermediate hosts as does Opisthorchis viverrini, with which it is sympatric in this province. In this study, we refer to the liver fluke from ducks as “Opisthorchis sp. BD2013”, and provide new sequence data from the mitochondrial (mt) genome and the nuclear ribosomal transcription unit. A phylogenetic analysis was conducted to clarify the basal taxonomic position of this species from ducks within the genus Opisthorchis (Digenea: Opisthorchiidae). Methods Adults and eggs of liver flukes were collected from ducks, metacercariae from fishes (Puntius brevis, Rasbora aurotaenia, Esomus metallicus) and cercariae from snails (Bithynia funiculata) in different localities in Binh Dinh Province. From four developmental life stage samples (adults, eggs, metacercariae and cercariae), the complete cytochrome b (cob), nicotinamide dehydrogenase subunit 1 (nad1) and cytochrome c oxidase subunit 1 (cox1) genes, and near-complete 18S and partial 28S ribosomal DNA (rDNA) sequences were obtained by PCR-coupled sequencing. The alignments of nucleotide sequences of concatenated cob + nad1 + cox1, and of concatenated 18S + 28S were separately subjected to phylogenetic analyses. Homologous sequences from other trematode species were included in each alignment. Results Phylogenetic trees were inferred from concatenated (cob + nad1 + cox1) nucleotide sequences and combined 18S + 28S nucleotide sequences of five Opisthorchis sp. BD2013 samples and additional reference taxa. Both trees demonstrated the anticipated clustering of taxa within the superfamily Opisthorchioidea, the paraphyly of the genus Opisthorchis and the sister-species relationship of Opisthorchis sp. BD2013 with O. viverrini. Conclusions While it is likely that Opisthorchis sp. BD2013 is distinct from O. viverrini, it is clearly a sister taxon of O. viverrini within the limited number of Opisthorchis species for which appropriate sequence data are available. The new sequences provided here will assist the diagnosis and the taxonomic clarification of the opisthorchiid species.

We investigate theoretically quantum transport through the "charge" Kondo circuit consisting of the quantum dot (QD) coupled weakly to an electrode at temperature $T+\Delta T$ and connected strongly to another electrode at the reference temperature $T$ by a single-mode quantum point contact (QPC). To account for the effects of Coulomb interaction in the QD-QPC setup operating in the integer quantum Hall regime we describe the edge current in the quantum circuit by Luttinger model characterized by the Luttinger parameter $g$. It is shown that the temperature dependence of both electric conductance $G\propto T^{2/g}$ and thermoelectric coefficient $G_T\propto T^{1+2/g}$ detours from the Fermi-liquid (FL) theory predictions. The behaviour of the thermoelectric power $S=G_T/G\propto T$ in a regime of a single-channel Kondo effect is, by contrast, consistent with the FL paradigm. We demonstrate that the interplay between the mesoscopic Coulomb blockade in QD and weak repulsive interaction in the Luttinger Liquid $g=1-\alpha$ $(\alpha \ll 1)$ results in the enhancement of the thermopower. This enhancement is attributed to suppression of the Kondo correlations in the "charge" circuit by the destructive quantum interference effects., Comment: 10 pages, 2 figures

While conducting sentinel surveillance of hand, foot, and mouth disease (HFMD) in Vietnam, we found a sudden increase in the prevalence of coxsackievirus A10 (CV-A10) in 2016 and CV-A2 and CV-A4 in 2017, the emergence of which has been reported recently to be associated with various clinical manifestations in other countries. However, there have been only a limited number of molecular studies on those serotypes, with none being conducted in Vietnam. Therefore, we sequenced the entire VP1 genes of CV-A10, CV-A4, and CV-A2 strains associated with HFMD in Vietnam between 2012 and 2017. Phylogenetic analysis revealed a trend of endemic circulation of Vietnamese CV-A10, CV-A4, and CV-A2 strains and the emergence of thus-far undescribed HFMD-causing lineages of CV-A4 and CV-A2. The Vietnamese CV-A10 strains belonged to a genotype comprising isolates from patients with HFMD from several other countries; however, most of the Vietnamese strains were grouped into a local lineage. Recently, emerging CV-A4 strains in Vietnam were grouped into a unique lineage within a genotype comprising strains isolated from patients with acute flaccid paralysis from various countries. New substitutions were detected in the putative BC and HI loops in the Vietnamese CV-A4 strains. Except for one strain, Vietnamese CV-A2 isolates were grouped into a unique lineage of a genotype that includes strains from various countries that are associated with other clinical manifestations. Enhanced surveillance is required to monitor their spread and to specify their roles as etiological agents of HFMD or "HFMD-like" diseases, especially for CV-A4 and CV-A2. Further studies including whole-genome sequencing should be conducted to fully understand the evolutionary changes occurring in these newly emerging strains.

The integration of large-scale 2D bimetallic Ag/Au nanodisk arrays with gold nanoparticles is developed for sensing DNA conformation with the assistance of 3D finite-difference time-domain simulation. The optimized system comprising Ag/Au nanodisk arrays and gold nanoparticles offers a more than 6-fold enhancement in surface plasmon resonance shift, enabling the feasibility for sensitive DNA detection with a detection limit down to 100 femtomolar. Importantly, owing to the distance-dependent nature of the surface plasmon signal, sensitive differentiation of DNA conformations can be achieved with a conventional optical measurement. This platform could provide new exciting capabilities for a reliable, reproducible, and label-free assay analysis for investigating the conformations of DNA and other biological molecules.

Breast cancer (BC), the most common type of cancer among women worldwide, is a polygenetic disease which is caused by the interaction of several genes. Understanding the genetic factors for early diagnosis of BC is crucial to ensure the survival of BC patients. MicroRNA 27a (miR-27a), an oncogenic miRNA, has been predicted to target on the tumor suppressor ZBTB10 that can regulate many processes of cell. Single nucleotide polymorphism (SNP) rs895819 alters the structure and function of miR-27a, which has been anticipated to reduce the risk of BC in different populations such as German and Chinese. This study aimes to investigate the relationship between the existence of SNP rs895819 (A>G) and the risk of BC using the optimized high resolution melting (HRM) method. 106 BC samples and 117 healthy samples were genotyped using an optimal HRM protocol then statistical analysis was applied to examine the relationship of the SNP. In the case group, the risk G allele accounted for 36 % while in the control group it took up 32 %. Statistic result revealed that rs895819 (A>G) had no significant relationship with the breast cancer (OR=1.119; P=0.46676) in given case-control samples. Although the SNP is significantly ralated with BC in German or Chinese populations, it is not a potential marker for diagnosis in the Vietnamese population. Further studies investigating relationship between rs895819 (A>G) and breast cancer in the Vietnamese population is not recommended. In future, other SNPs should be investigated with the aim of identification efficient biomarker for early diagnosis of BC in Vietnamese.

As the second most popular cancer in the world, breast cancer affects millions of people and causes a large number of deaths every year. Identifying the genetic marker is one of approaches of early diagnosis for following cancer and give a correct treatment. Many recent studies have shown several SNPs including rs10941679 (located at the uptream of MRPS30 gene) are strongly associated with breast cancer in European and other populations. The association between rs10941679 and breast cancer in Vietnamese population has been investigated in this study using High Resolution Melt (HRM) method as a tool for genotyping. HRM was designed on Umelt sofware and was optimized based on annealing temperature and MgCl2 concentration gradient in order to have 3 distinct melting curves from 3 genotypes of rs10941679. The optimal HRM conditions were selected with Tm=58 oC and MgCl2=3.0 mM and 100 Cases/control samples were genotyped by the optimimal HRM condition. The results showed that the frequency of the risk allele G in case and control group were 48.5 % and 54.0 %, respectively. Regression analysis on the presense of the risk allele and risk allele-containing genotypes has shown no association between rs10941679 and breast cancer in Vietnamese population (OR = 0.80; 95% CI = [0.54 – 1.19]; PG = 0.27; PGG/GA = 0.56). The power of this result was estimated to be 12.02 %. To obtain the power up to 90 %, the sample size up to 1691 cases/controls is needed. Due to its low posibility in the assocation with breast cancer in Vietnamese population, rs1094169 is not recommended for further study in finding the genetic for markers cancer in Vietnamese population.

Following the first report of Opisthorchis viverrini infection in a domestic duck in Phu My District of Binh Dinh Province, Central Vietnam, many other cases were observed in the province. We determined the infection rate and intensity of O. viverrini infection in ducks in 4 districts of the province. A total of 178 ducks were randomly selected from 34 farms for examination of flukes in the liver and gall bladder. An infection rate of 34.3% (range 20.7-40.4% among districts) was found; the intensity of infection was 13.8 worms per infected duck (range 1-100). These findings show the role of ducks as a host for O. viverrini, duck genotype, which is sympatric with the human O. viverrini genotype in this province. It also stresses the need for investigations on the zoonotic potential and the life cycle of this parasite.

Opisthorchiasis caused by Opisthorchis viverrini is a major public health problem in the Mekong Basin in South East Asia. It is associated with cholangiocarcinoma, a fatal cancer of the bile duct, which is very common in some areas of Thailand and Lao PDR. Although there is evidence of opisthorchiasis in the central and Southern provinces of Vietnam, data are scarce and Vietnam is often not considered an opisthorchiasis endemic area in the international literature. We conducted a cross-sectional survey in June 2015 in a lowland rural area of Binh Dinh Province in Central Vietnam to investigate the apparent prevalence of O. viverrini infection in the population and the associated risk factors. A total of 254 stool samples were collected and examined by the Kato Katz method. Consenting people shedding Opisthorchis-like eggs with their stools were treated with praziquantel and MgSO4 and adult worms were collected from stools for morphological and molecular identifications. Risk factors were studied with a structured questionnaire and the association with infection was evaluated by univariate and multivariate Firth's logistic regression analysis. The apparent prevalence in the investigated population determined by stool examination was 11.4% (CI: 8-16%). Infection with O. viverrini was confirmed in all 11 individuals consenting to receive praziquantel treatment and subsequent worm recovery from stools. The mean number of worms recovered after treatment/purgation was 14.5 (range 2-44). Male gender and the consumption of dishes prepared from raw small wild-caught freshwater fish (Carassius auratus) were found to be significant risk factors associated with opisthorchiasis in the area. These findings confirm the presence of O. viverrini infection in Central Vietnam related to the consumption of raw fish dishes. Awareness campaigns and control programs should be implemented in the region to combat this potentially fatal fluke infection.

The control of the aging conditions for the aluminium alloys has been considered as an effective strategy to improve the properties of the alloy, especially in enhancement of the corrosion resistance. In this study, a detailed investigation of the effect of one-stage (T6) and two-stage (T76x) aging temper on mechanical properties, exfoliation and intergranular corrosion behaviours of 7075 Al–Zn–Mg–Cu alloy was implemented. Microstructures of the aged alloys were observed by optical microscopy and scanning electron microscopy (SEM), exfoliation and intergranular corrosion behaviours were investigated according to ASTM G34-2001 and ASTM G110-1992, respectively; the mechanical properties of the aged alloys were determined followed the standard methods. The microstructures of the sample aged with the T6 temper showed the finer particle size of precipitates than that of obtained from T76x tempers. Additionally, while the T6-aged sample revealed no appearance of the Precipitate Free Zones (PFZ), the PFZ with 40–50 nm in width was observed in the alloys treated with T76x tempers. The mechanical properties of the sample aged with T76x temper were negligibly reduced comparing to that of obtained with T6 temper, however, the exfoliation and intergranular corrosion behaviours were significantly improved by using two-stage aging conditions. The mechanism in enhancement of the corrosion resistance of the alloys treated with T76x temper over T6 temper was also discussed.

Objectives: This study investigated the short-term effects ambient air pollution with hospital admissions due to respiratory diseases and cardiovascular diseases in three provinces in Northern Viet...

The research aims at estimating the tourism and recreational values of Can Gio Mangrove Biosphere Reserve, Ho Chi Minh City, specifically, assessed the tourism potential via the willingness-to-pays of respondents (including domestic tourists and local people) for sustaining the landscape and regenerating natural resources as well as protecting the environment. The zone travel cost method was adopted in this study, to firstly plot the demand curve and then to estimate the values of recreation for visitors, eventually, come up with the total economic value of natural resources and environment of the research site. The results showed that the total recreational value of this resort is 6,542.3 billion VND while the consumer surplus values that visitors would receive from tourism activities are 1,389 billion VND. Each the tourist is willing to pay 107 thousand VND to improve the quality of tourism services, upgrading the infrastructure, sustaining the environmental quality and protecting the pristine look of the landscape.

Interpretation of wireline logging data supported to recover the sedimentary environment of block 102 of Song Hong basin. It inchided in determination of the spatial distribution of source, reservoir and cap rocks and an indispensable part in oil exploration of this area. Resulted wireline logging data showed some sedimentary environment units as the following The late Oligocene was delta environment. It was identified as forming delta plain, swamp to lacustrine. The middle Miocene had changed to shallow water marine environment, which formed the shoreface, tidal flat, lagoon and channel. The lower Miocene was aluvial environment that changed into fluvial and coastal plain.

Gas sensing is one of the most promising applications for reduced graphene oxide (rGO). High surface-to-volume ratio in conjunction with remaining reactive oxygen functional groups translates into sensitivity to molecular on the rGO surface. The response of the rGO based devices can be further improved by functionalizing its surface with metal nano-materials. In this paper, we report the ammonia (NH3) sensing behavior of rGO based sensors functionalized with nano-structured metal: silver (Ag) or platinum (Pt) or gold (Au) in air at room temperature and atmospheric pressure. The gas response is detected by the monitoring changes in electrical resistance of the rGO/metal hybrids due to NH3 gas adsorption. Compared to bare rGO, significantly improved NH3 sensitivity is observed with the addition of nano-structured metals. These materials are applied to play the small bridges role connecting many graphene islands together to improve electrical conduction of hybrids while maintaining the inherent advantage of rGO for NH3 gas sensitivity.

The synthesis of polystyrene-block-poly(iso-butyl vinyl ether) by using the combination of metallocene catalyst and atom transfer radical polymerization (ATRP) has been tried. This synthetic method takes advantages of both metallocene catalyst to form stereoregular polymer with high activity and ATRP with the controlled molecular weights and low polydispersity. The recent dinuclear half-sandwich complexes of titanium with xylene bridge, [Ti(η5-cyclopentadienyl)Cl2L]2-ortho, meta-[CH2-C6H4-CH2] (L = Cl, L = O-2,6-iPr2C6H3 ) were successfully synthesized. These catalysts were characterized by 1H NMR, 13C NMR and elemental analysis. Copolymers have been characterized by using gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). The collected copolymers have got narrow molecular weight distribution (≤1.8) and the improvement of stereoregularity (racemo dyads, r, are from 45 % to 56 %).