The COVID-19 pandemic and the emergence of Vietnam as a middle power

Limited capability and political will have caused the great powers to fail to demonstrate their global leadership in the fight against the COVID-19 pandemic, which has created greater room to manoeuvre for other countries to influence international affairs. Preliminary achievements in the fight against the COVID-19 crisis have buttressed the rising global status of small and medium-sized states, including Vietnam. Although Vietnam has recently been recognised as an emerging middle power, scepticism looms regarding whether this higher international status is beyond its capacity. We argue that the pandemic may act as a catalyst for Vietnam to further elevate its strategic role as a middle power on the international stage in the medium and long term

Evaluation of Pseudomonas stutzeri AM1 and Pseudomonas oleovorans ST1.1 isolated from shrimp pond sediments as probiotics for whiteleg shrimp, Litopenaeus vannamei culture

This study aimed to isolate the probiotic potential of nitrifying bacterial strains and to evaluate their effects on water quality and growth performance of the whiteleg shrimp, Litopenaeus vannamei. Based on an initial screening of 100 isolates identified from sediment samples, 12 strains could remove nitrogen compounds and two strains (Pseudomonas stutzeri AM1 and P. oleovorans ST1.1) showed highly efficient nitrogen removal ability. Within 96 h, total ammonia nitrogen (TAN) removal efficiency in the two strains was 28.0-31.6% and 21.5-24.9%, respectively. The water addition of 103 CFUmL-1 of P. stutzeri AM1 (T1) and P. oleovorans ST1.1 (T2) effectively reduced TAN, nitrite, nitrate, and total sulfide and increased the survival rate and biomass of shrimp. However, no significant differences were found between the control (T0) and treatment groups (T1 and T2) in the final weight, weight gain and specific growth rate of shrimp. Overall, P. stutzeri AM1 (T1) and P. oleovorans ST1.1 used as water supplements improved water quality and the survival rate of whiteleg shrimp

Nature of the interaction between rare gas atoms and transition metal doped silicon clusters: the role of shielding effects

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Mass spectrometry experiments show an exceptionally weak bonding between Si7Mn+ and rare gas atoms as compared to other exohedrally transition metal (TM) doped silicon clusters and other SinMn+ (n = 5-10) sizes. The Si7Mn+ cluster does not form Ar complexes and the observed fraction of Xe complexes is low. The interaction of two cluster series, SinMn+ (n = 6-10) and Si7TM+ (TM = Cr, Mn, Cu, and Zn), with Ar and Xe is investigated by density functional theory calculations. The cluster-rare gas binding is for all clusters, except Si7Mn+ and Si7Zn+, predominantly driven by short-range interaction between the TM dopant and the rare gas atoms. A high s-character electron density on the metal atoms in Si7Mn+ and Si7Zn+ shields the polarization toward the rare gas atoms and thereby hinders formation of short-range complexes. Overall, both Ar and Xe complexes are similar except that the larger polarizability of Xe leads to larger binding energies.DFG, FOR 1282, Controlling the electronic structure of semiconductor nanoparticles by doping and hybrid formatio

Endoparasites in pigs raised in smallholder farms in Hung Yen province of Vietnam

As being part of an ongoing project, assessing animal health and food safety risks in smallholder pig value chains in Hung Yen province of Vietnam, the presence of endoparasites was investigated in a repeated study. Three communes, with a total of 545 smallhoder pig farms, from three districts were selected. In each commune, ten farms were randomly chosen. On farm data including farm management and biosecurity measures were recorded by using a checklist and observations. From each farm, one pooled fecal sample was collected from a randomly chosen barn monthly and followed from June to December 2014 for seven months. Fecal samples were analyzed for intestinal parasites by floatation and sedimentation methods. The intensity of most commonly seen parasites was determined by the McMaster counting technique. In 198 collected fecal samples, six types of parasites were detected, namely Eimeria 89 (44.95%), Ascaris suum 43 (21.72%), Strongyloides sp. 41 (20.71%), Trichocephalus suis 19 (9.60%), Fasciolopsis buski 10 (5.05%), and Fasciola 2 (1.01%). Highest intensities were observed for Eimeria (maximum 80900 oocyst/g), followed by Ascaris suum (2400 egg/g), Strongyloides sp. (1900 egg/g), and Trichocephalus suis (1300 egg/g); the others were reported at much lower intensities. Infection levels and intensities of the parasites tended to be higher during the hot months, June to September. No significant difference between communes was found. At least one type of parasites was present in 137 samples (69.19%). Most of farms (96.67%) were positive for at least one type of parasites in at least one sample. There was a significant difference in infection level of endoparasites between biogas and non-biogas farms. The general high parasite burden reported in this study will be addressed in future interventions which will include parasite control apart from other measures

An HPLC Quantitative Analysis of Paraquat in Human Plasma: A Helpful Tool for Diagnosis and Evaluation of Treatment of Paraquat Poisoning in Vietnamese Hospitals

In this paper, the paraquat (PQ) concentrations in plasma of poisoned patients were determined by high performance liquid chromatography (RP-HPLC) with a DAD detector followed simple extraction of PQ from plasma. The sample was simply pretreated with 15% trichloroacetic acid for deproteinization and directly injected to HPLC system. PQ in plasma was separated on a C8 column HPLC system using 2 channel mobile phase (A and B) with a volume ratio of 5:95, respectively. Channel A was 5% acetonitrile (ACN) and Channel B was a mixture of phosphate buffer (pH 2.5), sodium 1-heptanesulphonate (0.11% w / v), KCl (0.20% w / v), polyethylene glycol G400 (0.20% v / v) and methanol (20% v / v). The flow rate of mobile phase was 0.5 mL/min. The method detection limit (MDL) is 0.013 ?g/ mL and the quantitative limit is 0.040 ?g/ mL. The recovery of PQ in plasma samples was 96.1% - 105.9 % at 5 different concentrations ranging from 0.040 ?g / mL to 10.00 ?g/ mL. The within- and between-day relative standard deviations were all less than 0.82% and 1.43% respectively. The method was successfully applied for determining paraquat concentrations in plasma samples of 31 acute paraquat poisoned patients at Poison Control Center, Bach Mai hospital, Vietnam. Quantitative results revealed that plasma PQ level was a key factor for prognosis and hemoperfusion using resin membrane had significant effect in removing PQ from the blood

A THEORETICAL STUDY ON CHEMICAL BONDING AND INFRARED SPECTRA OF SinM (M = Sc, Y; n = 1-10) CLUSTERS

In this paper, we applied the B3P86 method and DGDZVP basis set to investigate electronic properties and infrared (IR) spectra for SinM (M = Sc, Y; n = 1-10) clusters. The NBO analyses show that electron transfers from the dopant atoms to silicon frame of the SinM clusters. It is remarkable that the Si-M bond is mainly formed by the overlaps of the 3s-AOs and 3p-AOs of Si atoms, and 3d-AOs and 4s-AOs of Sc (or 4d-AOs and AO-5s of Y). The chemical bonds in the SiM and Si2M clusters are dominated by the covalent character including sigma and pi bonds. In addition, the analysis of the IR spectra suggests that the vibrational modes of SinM clusters are delocalized over the whole cluster. Moreover, the high-frequency and strong-intensity modes usually involve the vibrations of the dopant atoms. The results of this work provide fundamental information for experimental studies on transition-metal doped silicon clusters

Pencil lead graphite electrochemically modified with polyglutamic acid as a sensor for detection of enrofloxacin in aqueous media

This study investigates the modification of pencil lead graphite electrodes with polyglutamic acid using an effective and fast static method to develop a sensor for the detection of enrofloxacin (ENR). The successful fabrication of pGA on the electrode surface was confirmed by scanning electron microscopy, energy dispersive X-ray analysis, and Fourier-transform infrared spectroscopy. The conditions of electrochemical modification, including the applied potentials and number of cycles in the potentiostatic process, were systematically investigated to determine their effects on the ENR electrochemical response. The pH of the electrolyte media was also explored to elucidate the electrochemical reaction mechanism of ENR. The developed electrochemical sensor was evaluated using square wave stripping voltammetry for ENR detection. Under optimal conditions, the sensor demonstrated good reproducibility with a relative standard deviation of 4.3% (from five measurements) for ENR signal detection. A linear relationship between ENR concentration and its peak current was observed in the concentration range of 0.1 to 5 µM, with a high correlation coefficient of 0.9988. The limit of detection for ENR using the sensor was 0.12 µM. Our findings provide valuable insights into the design and optimisation of pencil lead graphite electrode-based sensors for ENR detection in aqueous media

Development of a highly sensitive point‐of‐care test for African swine fever that combines EZ‐Fast DNA extraction with LAMP detection: Evaluation using naturally infected swine whole blood samples from Vietnam

[Background] While early detection and early containment are key to controlling the African swine fever (ASF) pandemic, the lack of practical testing methods for use in the field are a major barrier to achieving this feat. [Objectives] To describe the development of a rapid and sensitive point-of-care test (POCT) for ASF, and its evaluation using swine whole blood samples for field settings. [Methods] In total, 89 swine whole blood samples were collected from Vietnamese swine farms and were performed the POCT using a combination of crude DNA extraction and LAMP (loop-mediated isothermal amplification) amplification. [Results] The POCT enabled crude DNA to be extracted from swine whole blood samples within 10 min at extremely low cost and with relative ease. The entire POCT required a maximum of 50 min from the beginning of DNA extraction to final judgment. Compared to a conventional real-time PCR detection, the POCT showed a 1 log reduction in detection sensitivity, but comparable diagnostic sensitivity of 100% (56/56) and diagnostic specificity of 100% (33/33). The POCT was quicker and easier to perform and did not require special equipment. [Conclusions] This POCT is expected to facilitate early diagnosis and containment of ASF invasion into both regions in which it is endemic and eradicated

Evaluation of Phacoemulsification Cataract Surgery Outcomes After Penetrating Keratoplasty

BACKGROUND: Cataract is one of the reasons which causes impaired visual acuity (VA) of the eyes after penetrating keratoplasy (PK), which can be treated by cataract surgery after PK or triple procedure. Cataract surgery after PK has advantages that parameters of the eyes such as axial length, anterior chamber depth (ACD) as well as corneal curvature are stabilized after removing all sutures postoperatively, and intraocular lens (IOL) power can be calculated correctly. Therefore, postoperative VA will be improved significantly. In Vietnam, there have not been any study about cataract surgery after PK, therefore we conduct this research. AIM: To evaluate the outcomes of phacoemulsification cataract surgery following primary PK. METHODS: Non-randomized controlled intervention study. Ninteen eyes (19 patients) that underwent phacoemulsification plus IOL insertion after initial PK in Cornea department, Vietnam National Institute of Ophthalmology, from December 2013 to September 2014. RESULTS: All patients presented with reduced VA, including 17 eyes (89.9%) with VA ≤ 20/200, mean astigmatism was 7.9 ± 1.0 D. Clear corneal grafts in 16 eyes while corneal opacity was seen in 3 eyes. All eyes with cataract were diagnosed from grade 2. After cataract surgery, improved VA > 20/200 was achieved in 72.22% of cases. There was a markable reduce of postoperative astigmatism with 1,8 ± 0.8 D (p < 0.05). However, the immunologic graft reaction was presented in one eye, and two edematous corneas also reported after cataract surgery. After treatment, there was one cornea achieved its clarity. CONCLUSION: Phacoemulsification cataract surgery following initial PK showed good outcomes with improved postoperative VA, reduced astigmatism, and the ultimate graft survival rate was high

Indigenous knowledge in climate change adaptation: Case studies of ethnic minorities in the Northern Mountain Region of Vietnam

This study aims to investigate the indigenous knowledge (IK) of three ethnic minority groups in the Northern Mountain Region (NMR) of Vietnam. The groups include (1) Tay people who live at lower elevations; (2) a Dao community who tend to live in the middle elevations and (3) Hmong farmers who mainly reside at higher elevations areas of the mountain. This research intends to identify climate change (CC) and its impact on agricultural cultivation and find out how these groups can adapt to CC by applying their IK in agriculture practices. Data was collected through focus group discussions (n=9), in-depth interviews (n=80), and participant observation. From the 80 respondents, 27 live in Bac Kan province, 23 in Yen Bai province and 30 in Son La province; those who had experience in agricultural production, elderly and village heads. The results show that the NMR weather has significant changes that negatively impact agriculture cultivation and local livelihood. Although the respondents are from different ethnic minorities, these farmers are highly aware of the CC risks, leading into adaptation practices. While the Tay people's major adaptation strategies include the use of a variety of native plants and changing planting calendars, the Dao and Hmong people apply intercropping and local techniques methods in terracing fields using local varieties of livestock. Our findings highlight the importance of using the IK of ethnic minorities in adaptation towards CC. A better targeting about the use of local resources in future national policies and projects is encouraged.Nghiên cứu này nhằm thu thập kiến thức bản địa (IK) của ba nhóm dân tộc thiểu số ở Miền núi phía Bắc (MNPB) của Việt Nam bao gồm (1) dân tộc Tày chủ yếu sống ở vùng thấp; (2) Người Dao có xu hướng sống ở các độ cao trung bình; và (3) người Hmông chủ yếu cư trú ở các khu vực đồi núi cao. Nghiên cứu này nhằm xác định tình hình biến đổi khí hậu (BĐKH) và tác động của nó đối với sản xuất nông nghiệp, đồng thời tìm hiểu cách thức các nhóm dân tộc thiểu số này có thể thích ứng với BĐKH bằng cách áp dụng các kiến thức bản địa của họ vào thực tiễn sản xuất nông nghiệp. Dữ liệu được thu thập thông qua thảo luận nhóm tập trung (n = 9), phỏng vấn sâu (n = 80) và quan sát người tham gia. Trong số 80 người được hỏi, có 27 người sống ở tỉnh Bắc Kạn; 23 người ở tỉnh Yên Bái và 30 người ở tỉnh Sơn La, là những người có kinh nghiệm sản xuất nông nghiệp, người cao tuổi và trưởng thôn. Kết quả cho thấy thời tiết ở khu vực MNPB đã có những thay đổi so với trước gây tác động xấu đến canh tác nông nghiệp và sinh kế của cộng đồng. Mặc dù những người được hỏi từ các dân tộc khác nhau nhưng họ đều nhận thức được sự thay đổi này của thời tiết, do đó họ đã có những thích ứng riêng. Trong khi người Tày sử dụng giống cây trồng địa phương và thay đổi lịch thời vụ thì người Dao và Hmong chọn phương pháp xen canh và áp dụng kỹ thuật bản địa trên đất ruộng bậc thang và sử dụng gióng vật nuôi bản địa. Các phát hiện của chúng tôi giúp hiểu được tầm quan trọng của việc sử dụng IK trong thích ứng với BĐKH của các dân tộc thiểu số, từ đó có thể hướng đến mục tiêu tốt hơn việc sử dụng các nguồn lực địa phương trong các chính sách và dự án quốc gia trong tương lai