134 research outputs found

    A new record of congrid eel, Bathycongrus bleekeri (Congridae) from Vietnam

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    Three specimens of Bathycongrus bleekeri were collected during the survey in 2015 and 2017. The newly recorded species is described herein, a small, moderately elongate species of Bathycongrus with head and body compressed; vertical fins without black mark; tail slender, attenuated, but not filiform; trunk length 1.2 times greater than head length; teeth small, conical, in about three-four rows on jaws, in a small triangular patch on vomer; 28–29 preanal vertebrae, total of 111–113 vertebrae; 26–28 preanal lateral-line pores. Additional data on the morphology and distribution of the species increases the total number of known species in the family Congridae in Vietnamese waters to twelve

    Economic linkage in key economic zones: The case of Vietnam

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    This study was conducted to measure the level of economic linkage in key economic zones in central Vietnam generally and to measure the level of economic linkage in the tourism sector. Secondary data were collected from the Statistical Yearbook published by the General Statistics Office and the Local Bureau of Statistics and primary data collected from surveys of 102 hotels and tourism firms in the center of Vietnam. We used the Moran Index (I) to quantify overall economic aggregation across the region and that scoring method was used to measure the degree of linkage in regional tourism. The results show that the level of overall regional economic linkages was very low and this was also relevant when analyzing the tourism sector in some areas of the center of Vietnam. Based on the results, some recommendations are given for strengthening economic linkages in key economic regions of Vietnam

    The Efficiency and the Performance of the Logistics Global Supply Chain Activities to Vietnam Exportation: an Empirical Case Study

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    Purpose: This research paper aims to determine the factors affecting the efficiency and logistics performance index (LPI) of Vietnam's exports to foreign partners during 2018-2022 are due to the impact of the COVID-19 pandemic.   Theoretical Framework: Based on the primary factors affecting the efficiency and performance of global supply chain activities in logistics for Vietnam's exports, including practical impact and logistics results of enterprises in Vietnam. Based on the primary factors affecting the efficiency and performance of global supply chain activities in logistics for Vietnam's exports, including (1). Customs efficiency (speed, simplicity and predictability of customs clearance procedures) (2). Quality of infrastructure related to trade and transport, including Roads, railways, ports, airports, warehouses and information technology ...(3). The level of ease when arranging to transport import and export goods with competitive prices (costs such as warehousing fees, port fees, tolls ... ) (4). Capacity and quality of logistics service providers ... (5). Ability to track and trace shipments. (6). Timeliness of the shipment to the destination within the specified time limit. The practical impact and logistics results of enterprises in Vietnam.   Method: The panel approach allows the authors to explore the heterogeneity in data across countries. Fixed effects (FE) and random effects (RE) models were used to estimate the model. Then, the Hausman test is carried out to decide which model is appropriate. The data were collected from 240 observations from Vietnam and 80 major export partner countries of Vietnam.   Findings: The research results show that the cost, time and capacity of providing logistics services have the most significant impact on Vietnam's exports.   Practical & social implications: Overall, to increase the efficiency and logistics efficiency of enterprises. The Vietnamese Government needs to cooperate and propose ideas to partner countries to improve logistics activities for exports from Vietnam. Logistics is beginning to play an increasingly important role in the competitiveness of economies.   Originality values: This study also confirms the sustainability of the extended gravity model using OLS and RE methods by substituting different variables for the country's logistics efficiency and solving the endogenous problem in the model while applying the regression method to industrial variables. We find that an 1% improvement in Vietnam's logistics would increase Vietnam's exports by 1.443%, and an 1% improvement in a partner country’s performance would help promote Vietnam's exports to this country by 0.546%

    Synthesis and Optical Characterization of Dye Doped in Ormosil Nanospheres for Bioapplications

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    Dye-doped ORMOSIL (organically modified silicate) nanoparticles (NPs) have significant advantages over single-dye labeling in signal amplification, photostability and surface modification for various biological applications. The dyes: Rhodamine 6G (R6G) and Rhodamine B (RB) were successfully incorporated into ORMOSIL nanoparticles fabricated by micellar nanochemistry from Trimethoxysilane CH3_3Si(OCH3_3)3_3 precursor. The optical characterization of dye-doped ORMOSIL NPs was studied in comparison with it’s of free dye in solution. The results shown that the photostability of ORMOSIL dye doped nanospheres is much improved in comparison with it’s of dye in solution. Other studies of the photophysical properties such as anisotropy, fluorescence lifetime and energy transfer were also done

    Does exporting spur firm productivity and promote inclusive growth? : evidence from Vietnam

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    Are exporting firms superior because only superior firms choose to become exporters or do they become superior by virtue of being exporters and having to face greater competition and to specialize in core activities? Findings show that the decision to export induces a gain in capital productivity for the new exporters, but no significant effect is observed for labour productivity and Total Factor Productivity (TFP). This result offers some support for the learning-by-exporting effect that occurs within a sector. Entry of Vietnamese firms into the world market can spur inclusive economic growth of the country

    CÁ MÚ GIỐNG VÀ BẢO VỆ BÃI GIỐNG Ở ĐẦM THỊ NẠI, VỊNH QUY NHƠN VÀ ĐẦM CÙ MÔNG

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    The wild grouper fingerling have provided the important seed source for the development of commercial fish farming. Among the wild grouper fingerling collected in the Thi Nai lagoon, Quy Nhon bay (Binh Dinh) and Cu Mong lagoon (Phu Yen), 7 species of grouper have been identified as Banded grouper (Epinephelus amblycephalus), Yellow grouper (E. awoara), Longtooth grouper (E. bruneus), Malabar grouper (E. malabaricus), Sixbar grouper (E. sexfasciatus), Orange-spotted grouper (E. coioides) and grouper (Epinephelus sp.); in which three species of Longtooth grouper, Malabar grouper and Orange-spotted grouper were endangered in Red List Categories Criteria of IUCN as VU and NT. The Malabar grouper seed makes up a high proportion of over 30%. The total length of the juveniles is different between species, ranging from an average of 25.0 mm to 116.82 mm; Orange-spotted grouper is 112.48 mm in total length; four grouper species Banded grouper, Yellow grouper, Longtooth grouper and Malabar grouper are longer than 30 mm in total length with 31.96, 32.23, 33.78 and 33.86 mm respectively. The Sixbar grouper and grouper (Epinephelus sp.) are smaller than 30 mm. The catching of grouper fingerling is distributed in wide area, along the bank, mangroves in the lagoon, along the western shore of the Quy Nhon bay, from Ghenh Rang to the southern part of the coast and along the Cu Mong lagoon (from south to southwest). The production of grouper seed fluctuates irregularly, 3 - 4 million seeds per year for highest yields, alternating with very low yields. The protection of nursing grounds is necessary with the solution of selective catching and limiting artisanal fishing.Cá mú giống khai thác tự nhiên đã cung cấp nguồn giống quan trọng cho việc phát triển nuôi cá thương phẩm. Nguồn cá mú giống khai thác tự nhiên ở vùng đầm Thị Nại, vịnh Quy Nhơn (Bình Định) và đầm Cù Mông (Phú Yên) đã xác định được 7 loài là cá mú chấm vạch (Epinephelus amblycephalus), cá song gio (E. awoara), cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus), cá mú sau sọc (E. sexfasciatus), cá mú mè (E. coioides) và cá song (Epinephelus sp); trong đó có ba loài là cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus) và cá mú mè (E. coioides) là những loài được IUCN xếp ở mức nguy cấp bậc VU và NT. Con giống cá mú điểm gai chiếm tỉ lệ khá cao trên 30%. Chiều dài toàn thân trung bình cá giống của các loài khác nhau, từ 25,0 - 116,82 mm; cá mú mè  có chiều dài toàn thân lớn nhất đếm 112,48 mm, ba loài cá mú chấm vạch, cá song gio và cá mú điểm gai có chiều dài lớn hơn 30 mm tưong ứng là 31,96; 32,23; 33,78 và 33,86 mm. Hai loài còn lại là cá mú sáu sọc và cá song đều có kích thước nhỏ hơn 30 mm. Vùng khai thác cá mú giống khá rộng; dọc theo các cồn, dãi cây ngập mặn trong đầm Thị Nại, ven bờ phía bắc lên phía tây của vịnh Quy Nhơn; nơi tập trung khai thác ở ven gần bờ phía tây vịnh, từ Ghềnh Ráng kéo dài vào đến khu vực phía nam và vùng dọc bờ của đầm Cù Mông (từ phía nam đến tây nam). Sản lượng khai thác các mú giống biến động khá thất thường, năm có sản lượng cao lên đến 3 - 4 triệu con/năm, xen kẽ có năm sản lượng rất thấp. Việc bảo vệ bãi giống là cần thiết với các giải pháp khai thác có chọn lọc và hạn chế khai thác tận thu

    Theranostic Gold Nanoshells: from Synthesis to Imaging and Photothermal Therapy Applications

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    Gold nanoshells (GNSs) were grown on monodispersed aminoprotpyltriethoxysilane (APTES) functionalized of silica nanoparticles (NPs) cores with varying sizes ranging from 40-180 nm synthesized by Stober route. Gold shells were deposited onto the surface of silica NPs by tetrakis(hydroxymethyl) phosphonium chloride (THPC) and electroless gold plating method. The coverage of the gold nanoshells on the surfaces of the silica NPs was evaluated using UV-VIS/NIR spectrospcopy and transmission electron microscopy (TEM). The plasmon resonance wavelengths of these gold nanoshells were tunable from visible to near infrared region. The GNSs were also bioconjugated with anti-HER2 monoclonal antibody for diagnostic breast cancer cells using dark field microscope technique. These GNS NPs play a role as nanoheaters transforming light to heat. With the present of these GNS NPs at volume density of 3.6×10103.6\times 10^{10} NPs.cm3^3 in chicken tissue samples, illuminated by 808 nm laser at the power density of 62~W.cm2^2 the temperature of tissue sample reachs 110\rc{ }C after 20 minutes illumination

    Investigating the leaching performance of ferric chloride solution for metallic alloys resulting from reduction smelting of spent lithium-ion batteries

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    Smelting reduction of spent lithium-ion batteries (LIBs) produces metallic alloys containing Co, Ni, Cu, Mn, and Fe. Finding suitable reagents in terms of efficiency, economics, and friendly environment for the dissolution of these metals from the alloys is very important for the recovery process of the metals. In this work, the employment of ferric chloride solution for the dissolution of the metals from the alloys was studied. The effect of parameters like FeCl3 concentration, temperature, time, and pulp density on the leaching efficiency of metals was investigated. Our results indicate that ferric ions in the leaching solutions act as oxidizing agents for the dissolution of the metals, while chloride anions as ligands for the formation of the complexes of the dissolved metal ions. The best conditions for the dissolution of full metals were 0.7 mol/L FeCl3, 12.5 g/L pulp density, 22oC, and 30 min. In comparison with HCl or H2SO4 leaching agents, ferric chloride shows some advantages like a decrease in the dosage of acids and oxidizing agents, fast reaction kinetics, and low energy consumption. With its advantages, ferric chloride solution is considered a potential leaching agent in the recovery process of valuable metals from spent LIBs

    The Light-to-heat Conversion of Gold Nanoshells and Nanorods in Tissues

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    We perform a set of experiments on photo-heating in tissues containing gold nanoshells (NSs) and nanorods (NRs). The temperature of tissues were measured with different amounts gold NSs and NRs under illumination of a continuous diode laser at 808 nm and power density from 20 to 62 W/cm2^{2}. The temperature of the tissues injected gold nanoparticles increased to $66 \pm  4^{\circ}C for 2.1×1082.1 \times 10^{8} NSs and  73± 473\pm  4 ^{\circ}C for gold 5.4×1095.4 \times 10^{9} NRs after 10 min exposition at power density 35 W/cm2^{2}. The control tissue without gold nanoparticles demonstrated a significantly lower temperature 40± 440 \pm  4 ^{\circ}C in the same time of illumination. The temperature can be reached up to around 100^{\circ}C for tissue with both NSs and NRs at 62 W/cm2^{2} inrradiation for 7107-10 min

    Completeness and reliability of mortality data in Viet Nam: Implications for the national routine health management information system

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    Background Mortality statistics form a crucial component of national Health Management Information Systems (HMIS). However, there are limitations in the availability and quality of mortality data at national level in Viet Nam. This study assessed the completeness of recorded deaths and the reliability of recorded causes of death (COD) in the A6 death registers in the national routine HMIS in Viet Nam. Methodology and findings 1477 identified deaths in 2014 were reviewed in two provinces. A capture-recapture method was applied to assess the completeness of the A6 death registers. 1365 household verbal autopsy (VA) interviews were successfully conducted, and these were reviewed by physicians who assigned multiple and underlying cause of death (UCOD). These UCODs from VA were then compared with the CODs recorded in the A6 death registers, using kappa scores to assess the reliability of the A6 death register diagnoses. The overall completeness of the A6 death registers in the two provinces was 89.3% (95%CI: 87.8–90.8). No COD recorded in the A6 death registers demonstrated good reliability. There is very low reliability in recording of cardiovascular deaths (kappa for stroke = 0.47 and kappa for ischaemic heart diseases = 0.42) and diabetes (kappa = 0.33). The reporting of deaths due to road traffic accidents, HIV and some cancers are at a moderate level of reliability with kappa scores ranging between 0.57–0.69 (p<0.01). VA methods identify more specific COD than the A6 death registers, and also allow identification of multiple CODs. Conclusions The study results suggest that data completeness in HMIS A6 death registers in the study sample of communes was relatively high (nearly 90%), but triangulation with death records from other sources would improve the completeness of this system. Further, there is an urgent need to enhance the reliability of COD recorded in the A6 death registers, for which VA methods could be effective. Focussed consultation among stakeholders is needed to develop a suitable mechanism and process for integrating VA methods into the national routine HMIS A6 death registers in Viet Nam.This study was funded by the Centers for Disease Control and Prevention, Viet Nam (CGH HSR 2015-009)
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