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This paper examines the role of Exchange Rate Uncertainty (ERU) in driving economic fluctuations in emerging economies using a VAR with stochastic volatility in the mean. We use the quarterly data of three typical emerging economies from 1972Q3 to 2009Q4 within a VAR model. We show that ERU plays a vital role in driving the business cycles of emerging economies. First, an ERU can provoke risks in the financial market and the real economy. Second, ERU hurts equity prices and the output growth of emerging economies. Further investigation shows that the adverse effects of ERU on output are more severe under the fixed exchange rate regime than under the flexible exchange rate regime. This finding implies that adopting the flexible exchange rate regime can help emerging economies mitigate the adverse effects of uncertainty shocks.

Abstract Among the congener of dioxin, 2,3,7,8-TCDD is the most toxic, having a serious long-term impact on the environment and human health. UDP-glucuronosyltransferase 1A1 (UGT1A1) plays a crucial role in the detoxification and excretion of endogenous and exogenous lipophilic compounds, primarily in the liver and gastrointestinal tract. This study aimed to investigate the association of UGT1A1 gene polymorphisms, expression levels, and enzyme concentration with Agent Orange/Dioxin exposure. The study included 100 individuals exposed to Agent Orange/Dioxin nearby Da Nang and Bien Hoa airports in Vietnam and 100 healthy controls. UGT1A1 SNP rs10929303, rs1042640 and rs8330 were determined by Sanger sequencing, mRNA expression was quantified by RT-qPCR and plasma UGT1A1 concentrations were measured by ELISA. The results showed that UGT1A1 polymorphisms at SNPs rs10929303, rs1042640 and rs8330 were associated with Agent Orange/Dioxin exposure (OR = 0.55, P = 0.018; OR = 0.55, P = 0.018 and OR = 0.57, P = 0.026, respectively). UGT1A1 mRNA expression levels and enzyme concentration were significantly elevated in individuals exposed to Agent Orange/Dioxin compared to controls (P

Modification of graphene oxide (GO) by vinyltriethoxysilane (VTES) was investigated to study the effect of silanized GO on radical graft copolymerization of GO onto deproteinized natural rubber (DPNR). The modified GO, GO-VTES (a and b), was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, contact angle, thermal gravimetric analysis, and scanning electron microscopy. The XRD results showed the appearance of an amorphous region of silica particles at a diffraction angle of 22°. The formation of silica was investigated by 29Si NMR, and it was found that the hydrolysis and condensation of VTES proceed more completely in basic conditions than in acidic conditions. The silica content of GO-VTES(b) was 43%, which is higher than that of GO-VTES(a) (8%). Morphology of silica was observed by SEM. The DPNR/GO-VTES nanocomposites prepared with the same amount of GO, GO-VTES(a), and GO-VTES(b) were characterized with tensile tests and dynamic mechanical tests. The stress at break of DPNR/GO-VTES(a) and DPNR/GO-VTES(b) was 5.2 MPa and 4.3 MPa, respectively, which were lower than that of DPNR/GO. However, it exhibited higher stress at small strains and higher storage modulus than DPNR/GO.

Kẽm kim loại là vật liệu làm anốt tiềm năng cho pin sạc zinc-ion với dung lượng riêng lý thuyết cao, giá thành thấp, thân thiện với môi trường. Tuy nhiên, anốt Zn kim loại có hiệu suất coulombic thấp và sự phát triển các cấu trúc hình nhánh cây trên bề mặt kẽm khi sạc/xả làm hạn chế ứng dụng thực tế của chúng. Trong nghiên cứu này, nhóm tác giả hợp kim hoá Zn kim loại với Al bằng phương pháp luyện kim đơn giản và khảo sát các đặc tính điện hoá của các hợp kim này khi ứng dụng làm anốt cho pin sạc Zinc-ion. Kết quả cho thấy, hợp kim Zn88Al12 có hiệu suất sạc/xả tốt hơn rất nhiều so với các hợp kim Zn50Al50 và Zn. Đặc biệt ở mật độ dòng điện cao tại 1,0 mA/cm2 và 0,5 mAh/cm2, hợp kim Zn88Al12 có thể hoạt động với điện thế ổn định với khoảng thời gian kéo dài tới 140h. Hợp kim Zn88Al12 khi ứng dụng làm anốt kết hợp với vật liệu trên cơ sở V2O5 làm catốt đạt dung lượng riêng cao khoảng 300 mAh/g ở mật độ dòng điện sạc-xả 50 mA/g.

In reactor pressure vessel materials, the formation of Mn- and Ni-rich nanoclusters is a major cause of neutron irradiation embrittlement. The segregation of these solute atoms into dislocation loops has attracted attention as a mechanism to accelerate solute clustering. In this study, the behaviors of solute Mn and Ni atoms in Fe-0.6wt.%Ni, Fe-1.4wt.%Mn, and Fe-1.4wt.%Mn-0.6wt.%Ni alloys irradiated at 400 °C up to 3 dpa were analyzed using three-dimensional atom probe tomography. Solute atom clusters were observed in all materials, and their shapes were spherical, flat, and torus in FeNi, FeMn, and FeMnNi, respectively. In ternary alloy FeMnNi, Mn and Ni atoms were concentrated in the sample in the form of arcs, and the orientation of the plane containing the arcs was estimated by comparing field desorption images. The size, number density, and orientation of this structure were found to be in good agreement with those of both types of dislocation loops, namely, b = 1/2 〈111〉 and b = 〈100〉, identified in a previous study using the same material. The positions of Ni and Mn enrichment did not fully overlap. Ni atoms tended to be concentrated more in the inner part of the loop than the Mn atoms. Mn atoms were enriched only in the vicinity of the dislocation loops, whereas Ni atoms showed a higher concentration inside the dislocation loops than in the bulk.

Normalized difference vegetation index (NDVI) is a conditioning factor that significantly affects slope stabilization, as the low vegetation coverage can create conducive conditions for landslide occurrence. In previous studies, NDVI was often calculated from long-term average NDVI maps or specific yearly NDVI maps. However, this approach is unsuitable due to the time-varying nature of these data, influenced by numerous factors, including human activities. To solve this problem, this study uses NDVI as a time-varying factor. NDVI maps are generated from Sentinel 2 and Landsat_8 imagery at the onset of each rainy season between 2015 and 2020 in the mountainous region of Quang Ngai Province. Moreover, the landslide events that occurred within this 5-year period (2016–2020), along with a set of conditioning factors, are utilized to develop landslide susceptibility models based on three algorithms: logistic regression, support vector machine, and extreme gradient boosting (XGBoost). The obtained results demonstrate that using time-varying NDVI shows superior performance compared to using only NDVI from 2015. The outcomes also indicate that XGBoost is the most effective model. Selecting suitable NDVI maps can improve the predictive accuracy of landslide susceptibility mapping.

In the present work, AlN was modified with vinyltriethoxysilane (VTES), and its effect on the properties of a thermally conductive composite of high impact polystyrene (HIPS), and AlN was investigated. Three composites, HIPS/AlN5, HIPS/AlN9, and HIPS/moAlN9, were prepared by mixing HIPS and AlN in a toluene solution, followed by hot pressing. The HIPS/AlN composite was characterized by tensile test, impact strength, flexural strength, and hardness shore D. The sample HIPS/moAlN9 showed the improvement of these properties compared to that of the HIPS/AlN9 sample. The increment of those mechanical properties was due to the good interaction between the modified AlN and HIPS resin matrix, which was revealed by morphology observation by SEM. Incorporating modified AlN into the HIPS matrix was also found to enhance the thermal conductivity by about 20%, from 0.15 for HIPS to 0.18 (W/m·K) for HIPS/moAlN9. It was explained due to the good adherence of AlN to the HIPS, which provided more thermal conductive routes than HIPS/AlN. This approach provides a possible strategy to prepare thermally conductive HIPS composite, which may be suitable for electronic device that required heat dissipation.

Lymphoma-associated hemophagocytic syndrome is a life-threatening disease with poor prognosis and may present as ischemic stroke. We report a case of a 56-year-old female with recurrent multi-territory infarcts caused by diffuse large B-cell lymphoma with secondary hemophagocytic lymphohistiocytosis. She had been diagnosed with ischemic stroke and hemophagocytic syndrome probably secondary to Epstein-Barr virus infection 3 months previously and treated with Dexamethasone and Aspirin. High resolution vessel wall magnetic resonance imaging showed vessel wall thickening at some intracranial vessels suggesting vasculitis. Abdominal computed tomography scan revealed splenomegaly, multiple bilateral small nodules of the lung, multiple liver lesions, multiple bilateral renal masses, gastric wall thickening and multiple nodules in the omentum. Cerebrospinal fluid cytology showed increased cerebrospinal-fluid protein level. Hemophagocytosis was showed on bone marrow aspirate cytology. Gastric tissue biopsy revealed large B cell lymphoma. Chemotherapy was not given because the patient had severe pneumonia and sepsis. The patient died 28 days after the definitive diagnosis was confirmed. Ischemic stroke in our patient with diffuse large B-cell lymphoma may be due to vasculitis or intravascular large B-cell lymphoma.

In this work, we develop a mussel-inspired biosorbent combined with graphene oxide for removal of organic dyes in water sources. The composite was prepared via self-polymerization of dopamine in weak alkaline solution containing graphene oxide at ambient condition. Morphological and structural studies revealed that polydopamine has gradually grown to cover the surface of graphene oxide flakes, partially reduced these flakes, and somehow form many grains (size around 20 nm) on the flakes instead of making very large aggregates as usual. The mass ratio between two components of the composite was also investigated to find the optimal one which provides enough surface area (20 m2.g−1) and maintain adhesive sites in order to ensure high-efficiency removal of organic molecules. The adsorption kinetics and isotherms of as-prepared adsorbent towards methylene blue were found to fit well with pseudo-first order kinetics model and Langmuir isotherm. The maximum adsorption capacity (qm) and Langmuir constant (kL) were estimated to be 270 mg.g−1 and 0.49 L. mg−1. The as-prepared bio-sorbent is very promising for remediation of water sources contaminated with cationic organic molecules and heavy metal ions.

Abstract The JAK2 gene encodes for a non‐receptor tyrosine kinase that plays a key role in the JAK/STAT signaling transfer pathway. Genetic polymorphisms of this gene have been indicated to be associated with myeloproliferative neoplasm‐associated thrombosis in recent studies. This research aimed to evaluate the association between the variant rs10974944 and different types of Myeloproliferative neoplasms disorders in the Vietnamese population. DNA samples were obtained from 172 essential thrombocythemia patients, 14 primary myelofibrosis patients, 76 polycythemia vera patients, and 192 healthy controls. The JAK2 rs10974944 and V617F genotypes were identified by the polymerase chain reaction‐restriction fragment length polymorphism genotyping and Sanger sequencing methods. Results showed that there was a strong association between rs10974944 and Myeloproliferative neoplasms phenotype (p

The frequencies and diversities of human leukocyte antigen (HLA) alleles and haplotypes are representative of ethnicities. Matching HLA alleles is essential for many clinical applications, including blood transfusion, stem cell transplantation, and tissue/organ transplantation. To date, the information about the frequencies and distributions of HLA alleles and haplotypes among the Kinh Vietnamese population is limited because of the small sample size. In this study, more than 3,750 cord blood units from individuals belonging to the Kinh Vietnamese population were genotyped using PCR sequence-specific oligonucleotide (PCR-SSO) for HLA testing. The results of the study demonstrated that the most frequently occurring HLA-A, -B, -C, and -DRB1 alleles were A*11:01 (25%), A*24:02 (12.3%), A*02:01 (11.2); A*03:03 (8.95%), A*02:03 (7.81%), A*29:01 (7.03%); B*15:02 (15.1%), B*46:01 (10.7%), B*58:01 (7.65%), B*38:02 (7.29%); C*08:01 (17.2), C*07:02 (16.2%), C*01:02 (15.2), C*03:02 (8.3%), C*15:05 (6.13); DRB1*12:02 (31.0%), DRB1*09:01 (10.47%), DRB1*15:02 (7.54%); DRB1*07:01 (6.68%), DRB1*10:01 (6.63%), respectively, with the highest allele diversity level observed in locus B (93 alleles). The most frequent haplotypes of two-locus combinations of HLA-A–B, HLA-A–C, HLA-A–DRB1, HLA-B–C, HLA-B–DRB1, and HLA-C–DRB1 haplotypes were A*11:01–B*15:02 (7.63%), A*11:01–C*08:01 (7.98%), A*11:01–DRB1*12:02 (10.56%), B*15:02–C*08:01 (14.0%), B*15:02–DRB1*12:02 (10.47%), and C*08:01–DRB1*12:02 (11.38%), respectively. In addition, the most frequent haplotypes of three- and four-locus sets of HLA-A–B–C, HLA-A–B–DRB1, HLA-A–C–DRB1, HLA-B–C–DRB1, and HLA-A–B–C–DRB1 were A*11:01–B*15:02–C*08:01 (7.57%), A*11:01–B*15:02–DRB1*12:02 (5.39%), A*11:01–C*08:01–DRB1*12:02 (5.54%), B*15:02–C*08:01–DRB1*12:02 (10.21%), and A*11:01–B*15:02–C*08:01–DRB1*12:02 (5.45%), respectively. This study provides critical information on the frequencies and distributions of HLA alleles and haplotypes in the Kinh Vietnamese population, accounting for more than 85% of Vietnamese citizens. It paves the way to establish an umbilical cord blood bank for cord blood transplantation programs in Vietnam.

The Kontum Massif, located in central Vietnam, played an essential role in the evolution of Indochina and its adjacent areas. The Van Canh granites, exposed throughout the Southern Kontum Massif, display SiO2 contents ranging from 65.82 to 75.35 wt%, and total alkaline (Na2O + K2O) from 5.47 to 9.82 wt%, with A/CNK values between 0.97 and 1.08. The main rock-forming minerals of the Van Canh granites are quartz (25–30 vol%), K-feldspar (27–30 vol%), plagioclase (28–30 vol%), and biotite (3–5 vol%). The whole-rock chemical composition is characterized by Ba, Nb, Ce, P, and Ti- depletion, and the enrichment of Th, K, Pb, Nd, and Y. The ɛHf(t) values of zircon grains range from −11.1 to −6.7, and the Hf model ages (TDM2) are from 1.97 to 1.70 Ga. Their geochemical features are similar to the S-type granite, being derived from partial melting of Paleoproterozoic sources. The zircon Hf model ages and inherited zircon ages are evidence of Paleoproterozoic basement in the study region. LA-ICP-MS zircon U-Pb dating yields crystallization ages of 251–229 Ma, showing the existence of Triassic magmatism in the Kontum Massif. The Van Canh granites in the Kontum Massif, central Vietnam, provide significant evidence for the syn-/post-collision of North Vietnam-South China and Indochina blocks.

The present article is aimed to investigate the second cumulants, and the thermodynamic quantities are dependent on temperature and pressure in the X-ray absorption fine structure spectrum. The expressions have been build by using the model of the non-harmonic correlation of Einstein and Debye. A simple calculation was used to instead complex problems caused by the interaction of many particles in the system. The significant results of this work are the Morse potential parameters have been theoretically calculated method, determined the temperature dependence of the second cumulant, mean square displacement and correlation function for copper, tungsten, and copper-tungsten alloy of ratio 93-07 percent (W93Cu07) under pressure up to 14GPa. Calculated the second cumulant dependence on the pressure in a range from 0GPa to 14GPa and clearly analysed the difference between the second cumulant at different pressure for atoms of tungsten, copper and tungsten-copper alloy. Numerical results according to the present theory agree well with experimental data and previous views.

Hóa thạch gỗ được tìm thấy ở nhiều nơi trên lãnh thổ Việt Nam, trong các thành tạo địa chất của các kỷ Devon, Trias, Jura, Creta, Paleogen, Neogen và Đệ tứ. Nguyên thủy, chúng là thực vật thuộc các ngành Thạch tùng (Lycopodiophyta), Dạng dương xỉ (Polypodiophyta), Hạt trần (Gymnospermae) và Hạt kín (Angiospermae). Sau khi chết, thực vật được chôn vùi trong điều kiện đặc biệt và dưới ảnh hưởng của các hoạt động địa chất trên vỏ Trái Đất, hợp phần cơ thể của gỗ được thay thế bằng các khoáng vật như silic, calcedon, opal, mã não, calcit… Ngày nay, hóa thạch gỗ được trưng bày tại nhà, ở công sở, trong bảo tàng, công viên; một số có giá trị mỹ thuật được sử dụng làm trang sức cá nhân. Trong bài báo này, chúng tôi giới thiệu những khái niệm cơ bản về hóa thạch gỗ, tuổi địa chất, phương pháp nghiên cứu, giá trị khoa học cũng như mỹ thuật của chúng trên lãnh thổ Việt Nam

The State of Vietnam continues to show the cumbersome, limited effectiveness of the public sector and the widespread corruption of public servants. Yet, it has been endeavoring to renovate national governance in the direction of good governance to improve the quality of public services to meet the requirements of an increasingly high level of education and social life democratization. Since 2018, the Vietnamese government has been applying the Satisfaction Index of Public Administrative Services (SIPAS) to measure people’s satisfaction with administrative services. This fact has received full attention from scientists, and there have been many studies on this issue. Therefore, this study has explored the impact of good governance on people’s satisfaction with administrative services by employing some variables of the SIPAS scale, including five dependent variables, namely: accessibility; administrative procedures; civil servants’ ethics and capacity; the results of the procedure settlement; the reception and handling of comments, feedback, and recommendations; and an independent variable, namely the people’s satisfaction, to add more evidence to previous studies and enrich the research literature. This study has been conducted through a cross-sectional survey using an intentional sampling technique (n = 500). The multivariate linear regression analysis technique was applied to prove the hypotheses. According to the research findings, all independent variables have a positive and significant relationship with the dependent variable. They imply that good governance initially has positive and significant effects on the Vietnamese people’s satisfaction level.

Monofloral honey samples (Coffea robusta) from Vietnam were determined for their chemical compositions. This is the first report on the chemical composition and antioxidant activity of coffee honey from Vietnam. These samples were characterized by their high contents of total and reducing sugars, total phenolic contents, and total flavonoid contents. The contents of seven phenolic acids (PAs) were quantified by high performance liquid chromatography (HPLC) and analyzed with the assistance of principle component analysis (PCA) to differentiate the honey samples into groups. The hydroxymethylfurfural (HMF) (0.048–2.933 mg/kg) and free acid contents (20.326–31.163 meq/kg) of coffee honey were lower in Nepal, which reflected the freshness of the honey when conducting this survey. The coffee honey had total sugar and reducing sugar contents 831.711 g/kg and 697.903 g/kg, respectively. The high level of total phenolic (0.642 mg GAE/g) and flavonoid (0.0341 mg GE/g) contents of coffee honey contributed to their antioxidant activity of this honey sample. Among the coffee honey tested, the IC50 of DPPH radical-scavenging activities value was 1.134–17.031 mg/mL, while the IC50 of ABTS radical-scavenging activities value was 115.381–213.769 mg/mL. The phenolic acids composition analysis displayed that gallic acid appeared in high concentrations in all studied honey samples, ranging from 0.037–1.015 mg/kg, and ferulic acid content ranged from 0.193 to 0.276 mg/kg. The content of trigonelline and caffeine in coffee honey samples ranged from 0.314–2.399 mg/kg and 8.946–37.977 mg/kg. The data in this article highlight the relevance of coffee honey as a healthy substance.

Introduction: Extra-articular fractures of the distal radius, known as Colles’ fractures, are very common. The optimal management of Colles’ fracture is still controversial. The Kapandji technique is one option for orthopedic surgeons to maintain reduced fractures, however, the effectiveness of this method is no clear consensus. This study aims to access Colles’ fracture treatment by the Kapandji technique with our experiences. Methods: This prospective study of 33 patients treated with three K-wires intra-focal fractures by the Kapandji procedure for Colles’ fractures at Hue University of Medicine and Pharmacy Hospital in Vietnam between February 2017 and May 2019. The functional outcome of the patients was assessed by the demerit score system of Gartland and Werley, and the quality of reduction was elevated on radiographic as well at 3, 6, 12, and 24 weeks postoperative. Results: 33 patients’ mean age is 54.64 ± 18.00; After 24 weeks of postoperative follow-up, 78.79% presented excellent, 21.21% good, and there are not any fair or poor cases on the functional outcome. All patients achieved complete fracture union at 12 weeks postoperative. The average immediate postoperative radial length was 9.85 mm, the radial inclination was 20.64°, and the volar tilt was 9.2°. Conclusion: The study emphasizes that the Kapandji technique in Colles’ fracture treatment is simple and possible to bring a satisfactory outcome and fast recovery.

Allopurinol (ALP) is commonly used as a drug for gout treatment. However, ALP is known to cause cutaneous adverse reactions (CARs) in patients. The HLA-B*58:01 allele is considered a biomarker of severe CAR (SCAR) in patients with gout, with symptoms of Stevens Johnson syndrome, and with toxic epidermal necrolysis. However, in patients with gout and mild cutaneous adverse drug reactions (MCARs), the role of HLA-allele polymorphisms has not been thoroughly investigated. In this study, 50 samples from ALP-tolerant patients and ALP-induced MCARs patients were genotyped in order to examine the polymorphisms of their HLA-A and HLA-B alleles. Our results showed that the frequencies of HLA-A*02:01/HLA-A*24:02 and HLA-A*02:01/HLA-A*29:01, the dual haplotypes in HLA-A, in patients with ALP-induced MCARs were relatively high, at 33.3% (7/21), which was HLA-B*58:01-independent, while the frequency of these dual haplotypes in the HLA-A locus in ALP-tolerant patients was only 3.45% (1/29). The HLA-B*58:01 allele was detected in 38% (8/21) of patients with ALP-induced MCARs, and in 3.45% (1/29) of ALP-tolerant patients. Notably, although HLA-B*58:01 may be a cause for the occurrence of MCARs in patients with gout, this correlation was not as strong as that previously reported in patients with SCAR. In conclusion, in addition to the HLA-B*58:01 allele, the presence of the dual haplotypes of HLA-A*02:01/HLA-A*24:02 and/or HLA-A*02:01/HLA-A*29:01 in the HLA-A locus may also play an important role in the appearance of ALP-induced MCARs in the Vietnamese population. The obtained primary data may contribute to the development of suitable treatments for patients with gout not only in Vietnam but also in other Asian countries.