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Export-led growth has conventionally been regarded as a pivotal determinant of economic growth in developing countries. The article aims to affirm the vulnerability of Vietnam’s export sector due to its dependence on foreign direct investment flows and external market demand and evaluate the validity of the export-led growth strategy being applied in Vietnam among evolving global dynamics. The review of relevant literature explored the theoretical foundations, theories, and concepts of export-led and domestic demand-led growth with regard to the causal link between exports and economic growth. Qualitative and secondary research methods were used to analyze statistical data sets on imports and exports and domestic demand components to highlight their impact on the country’s GDP growth. The results showed that it is necessary to embrace both export-led growth and domestic demand-led growth as concurrent development paradigms, thereby ensuring the sustainability of Vietnam’s economic growth. Doi: 10.28991/HIJ-2024-05-02-05 Full Text: PDF

OBJECTIVE: This study determined the diagnostic performance of fluid-attenuated inversion recovery (FLAIR) signal intensity (SI) in discriminating between glioblastoma (GBM) and solitary brain metastasis (SBM). PATIENTS AND METHODS: We recruited 40 patients with a histologically confirmed diagnosis of GBM or SBM who underwent conventional 3 Tesla magnetic resonance imaging before surgery or biopsy between August 2020 and January 2022. Three regions of interest were placed to assess FLAIR SI: the enhancing region (eFLAIR), the peritumoral region (pFLAIR), and the contralateral normal white matter (nFLAIR). The diagnostic performance of significantly different parameters between the two tumor entities was analyzed by receiver operating characteristic (ROC) curve analysis. RESULTS: The pFLAIR SI was significantly lower in GBM than in SBM (p < 0.05). The eFLAIR SI and the SI ratio eFLAIR and nFLAIR (e/nFLAIR) were significantly higher in GBM than in SBM (p < 0.05). On ROC curve analysis, the e/nFLAIR ratio provided the highest area under the curve value of 81%, with a sensitivity of 80.8% and a specificity of 85.7%, for distinguishing between the two tumor types. CONCLUSIONS: The eFLAIR, pFLAIR, and e/nFLAIR parameters are useful for differentiating between GBM and SBM. [ABSTRACT FROM AUTHOR]

An important feature of improving lattice gas models and classical isotherms is the incorporation of a pore size dependent capacity, which has hitherto been overlooked. In this paper, we develop a model for predicting the temperature dependent variation in capacity with pore size. The model is based on the analysis of a lattice gas model using a density functional theory approach at the close packed limit. Fluid-fluid and solid-fluid interactions are modeled by the Lennard-Jones 12-6 potential and Steele's 10-4-3, potential respectively. The capacity of methane in a slit-shaped carbon pore is calculated from the characteristic parameters of the unit cell, which are extracted by minimizing the grand potential of the unit cell. The capacities predicted by the proposed model are in good agreement with those obtained from grand canonical Monte Carlo simulation, for pores that can accommodate up to three adsorbed layers. Single particle and pair distributions exhibit characteristic features that correspond to the sequence of buckling and rhombic transitions that occur as the slit pore width is increased. The model provides a useful tool to model continuous variation in the microstructure of an adsorbed phase, namely buckling and rhombic transitions, with increasing pore width. [ABSTRACT FROM AUTHOR]

Terazosin, a quinazoline derivative is an alpha-1-selective adrenoceptor blocking agent commontly used for the treatment of symptomatic benign prostatic hyperplasia. To control quality of material and finished products of terazosin, it is required to have some terazosin related compound reference standards including impurity A of terazosin (IAT). This study aims include the synthesis of IAT to establish a reference standard for drug quality control and investigation of an HPLC method to determine the content of the obtained IAT. The chemicals for synthesis and analysis were purchased from Sigma Aldrich and Merck (Germany). IAT was synthesized from 2-chloro-6,7-dimethoxyquinazoline-4-amino and piperazine, using isoamyl alcohol as a solvent. IAT's purification was carried out by column chromatography. Spectroscopic methods including IR, MS, NMR were used to characterize and confirm the structure of the product. The HPLC method, which was investigated to determine the content of IAT was validated according to the ICH guidelines. The total yield of synthesis and purify process of IAT was 71.1%. The content of the purified IAT was determined by comparison to USP Terazosin Related Compound A RS and its content achieved 97.28% calculated on the basis (99.47% calculated on the dried basis). Our results proposed the new synthesis, purification procedures for IAT and the determination method for the content of this product. The IAT obtained can be used to establish a reference standard substance for terazosin drug quality control. [ABSTRACT FROM AUTHOR]

Anaerobic digestion is an efficient and renewable energy technology that can produce biogas from a variety of biomasses such as animal manure, food waste and plant residues. In developing countries this technology is widely used for the production of biogas using local biomasses, but there is little information about the value of these biomasses for energy production. This study was therefore carried out with the objective of estimating the biogas production potential of typical Vietnamese biomasses such as animal manure, slaughterhouse waste and plant residues, and developing a model that relates methane (CH4) production to the chemical characteristics of the biomass. The biochemical methane potential (BMP) and biomass characteristics were measured. Results showed that piglet manure produced the highest CH4 yield of 443 normal litter (NL) CH4 kg-1 volatile solids (VS) compared to 222 from cows, 177 from sows, 172 from rabbits, 169 from goats and 153 from buffaloes. Methane production from duckweed (Spirodela polyrrhiza) was higher than from lawn grass and water spinach at 340, 220, and 110.6 NL CH4 kg-1 VS, respectively. The BMP experiment also demonstrated that the CH4 production was inhibited with chicken manure, slaughterhouse waste, cassava residue and shoe-making waste. Statistical analysis showed that lipid and lignin are the most significant predictors of BMP. The model was developed from knowledge that the BMP was related to biomass content of lipid, lignin and protein from manure and plant residues as a percentage of VS with coefficient of determination (R-square) at 0.95. This model was applied to calculate the CH4 yield for a household with 17 fattening pigs in the highlands and lowlands of northern Vietnam. [ABSTRACT FROM AUTHOR]

We present results of the reconstruction of a saccharose-based activated carbon (CS1000a) using hybrid reverse Monte Carlo (HRMC) simulation, recently proposed by Opletal et al. [1]. Interaction between carbon atoms in the simulation is modeled by an environment dependent interaction potential (EDIP) [2,3]. The reconstructed structure shows predominance of sp 2 over sp 3 bonding, while a significant proportion of sp hybrid bonding is also observed. We also calculated a ring distribution and geometrical pore size distribution of the model developed. The latter is compared with that obtained from argon adsorption at 87 K using our recently proposed characterization procedure [4], the finite wall thickness (FWT) model. Further, we determine self-diffusivities of argon and nitrogen in the constructed carbon as functions of loading. It is found that while there is a maximum in the diffusivity with respect to loading, as previously observed by Pikunic et al. [5], diffusivities in the present work are 10 times larger than those obtained in the prior work, consistent with the larger pore size as well as higher porosity of the activated saccharose carbon studied here. [ABSTRACT FROM AUTHOR]

This study determined toxicities of three insecticides/acaricides representing three classes (formamidines, avermectins, and norpyrethrates) to a prey-predator complex consisting of anthocorid bug ( Anthocoris nemoralis F.) and its phytophagous prey, pear psylla ( Cacopsylla pyri L.). The anthocorid bug LD50s were generally lower than those of the pear psylla indicating greater susceptibility in the predator than the prey. Determination of residual activities of the test insecticides indicates different selectivities to the beneficial insect. From this study, abamectin alone may be sprayed to control the pear psylla when the anthocorid bug populations are active. Reasons for the susceptibility variations to insecticides in phytophagous-entomophagous systems are suggested and discussed. [ABSTRACT FROM AUTHOR]