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Background: Acromioclavicular (AC) dislocation, one of the most common shoulder joint injuries, can be treated by several surgical methods. However, there are still few records about the treatment quality. This study aims to describe the outcomes of three surgical methods for acromioclavicular dislocation treatment at Viet Duc University Hospital, Vietnam. Methods: A cross-sectional study was conducted on 80 patients diagnosed with AC. We retrospectively collected data in the medical records and re-examined the patients. Results: There was no difference between the three groups of surgical approaches relating to the patient’s characteristics, except for the time from the accident to hospital admission. The median length of stay after surgery was highest in the Hook plate group (median (IQR) = 5(2) days), while it was lowest in the K-wire group (median (IQR) = 3(1) days) (p < 0.05). There is statistical significance in the difference of coracoclavicular distance between pre and post-operation in all three surgical method groups (p < 0.001). Conclusion: All of the methods—Hook plate, K-wire, and TightRope—were associated with optimistic outcomes and restored initial anatomy. While the three surgical methods are both safe and effective, the K-wire method is associated with a shorter length of stay and might be economical.

We study new monotonicity theorems for minimal surfaces in warped geometry. Applicationsinclude renormalised versions of the isoperimetric inequality for complete minimalsurfaces of the hyperbolic space and a vanishing result for knot/link invariants obtainedby counting these surfaces.; Nous étudions de nouveaux théorèmes de monotonicité pour les surfaces minimales engéométrie déformée. Les applications obtenues incluent des versions renormalisées del'inégalité isopérimétrique pour les surfaces minimales complètes de l'espace hyperboliqueet un résultat d'annulation pour les invariants de n\oe{}uds/entrelacs obtenus en comptant cessurfaces.

The mechanical properties of thixoextrusion components can be improved by controllable processing parameters such as the solid fraction of alloy, holding time, punch velocity, heat treatment and die temperature. In this study, the effects of thixoforming parameters on the microstructures and mechanical properties of thixoextrusion ADC12 alloy Aptomat Contact are studied. ADC12 has excellent castability with high fluidity and low shrinkage rate, so it is widely used in industry, especially in automotive and motorcycle engine part casting. It is a near eutectic alloy with high strength and low ductility (1%). The optimization parameters mechanical properties were investigated by changing the punch velocity, specimen temperature and holding time. The results also indicated optimal value at punch velocity (15 mm/s), specimen temperature (560 °C) and holding time (5 min) which was changed microstructure from eutectic dendrite to globular grain, increasing the ductility (3.3%) of this alloy during the semi-solid forming process while the remaining mechanical properties lead to an increase in the quality of finished parts.

The goal of this work is to assess the effect of technology factors on superplastic deformation of AA7075 sheets. The factors considered include strain temperature T, initial strain rate \( \dot{\varepsilon } \), while the response is maximum superplastic elongation (δ). Firstly, the experimental follow thermomechanical regime have determined, the result obtained is microstructural features of material with fine stable and grain size (~13 µm). Subsequently, a set of experiments were conducted in superplastic conditions such as strain temperature from 470, 500, 530, 550 °C and the initial strain rates from 5 × 10−4 s−1, 10−3 s−1, 1.5 × 10−3 s−1. Finally, an assessment of the effect of process parameters was used to determine the best superplastic deformation conditions. The results indicated that the maximum superplastic elongation of 280% could be obtained at 530°C and 10−3 s−1 strain rate. This work is expected as a significant contribution to determine a reasonable technology regime for superplastic deformation of AA7075 aluminum alloy.

Stock price prediction is a challenging financial time-series forecasting problem. In recent years, on account of the rapid progression of deep learning, researchers have developed highly accurate, state-of-the-art time-series models. Long short-term memory (LSTM) stands out as one of the most reliable architecture at capturing long-time temporal dependences. In Vietnam, there is a lack of research papers that solely focused on the effectiveness of deep-learning in stock price prediction. This paper surveys three different variations of LSTM (Vanilla, Stacked, Bidirectional) when applied to 20 companies’ stock prices over a period of 5 years from 2015 to 2020 in the VN-index stock exchange. The results show that Bidirectional LSTM is the most accurate model.

Superplasticity is the ability of an alloy to be permanently stretched to very high elongation within a limited range of conditions (grain size, deformation temperature and strain rate). The 7075 aluminium alloy superplastic sheet was used in this study. The AA 7075 sheets were prepared with microstructure using the thermomechanical treatment. The average grain size was 13 μm. The main purpose of this study is to investigate the influence of deformation parameters such as temperature and strain rate, on the deformation ability of 7075 aluminium alloy. The deformation ability of 7075 alloy was investigated under isothermal tensile tests. The results were analyzed to determine the optimum strain rate and temperature by using the Taguchi method and analysis of variance. The maximum superplastic elongation and the maximum stress were determined at different initial strain rates (5 × 10−4 s−1, 10−3 s−1 and 1,5 × 10−3 s−1) and temperatures (5000C, 5150C and 5300C), respectively. The optimum process parameters were obtained by analyzing the signal to noise ratio. The experimental results revealed that the effect of strain rate was more influential on the deformation ability than that of the temperature. The optimum results were achieved at the temperature of 530 °C and the strain rate of 10−3 s−1, respectively.

A simple approach was explored to prepare N-doped anatase TiO2 nanoparticles (N-TiO2 NPs) from titanium chloride (TiCl4) and ammonia (NH3) via sol–gel method. The effects of important process parameters such as calcination temperatures, NH3/TiCl4 molar ratio (R N) on crystallite size, structure, phase transformation, and photocatalytic activity of titanium dioxide (TiO2) were thoroughly investigated. The as-prepared samples were characterized by ultraviolet–visible spectroscopy, x-ray diffraction, transmission electron microscopy, energy dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. The photocatalytic activity of the samples was evaluated upon the degradation of methylene blue aqueous solution under visible-light irradiation. The results demonstrated that both calcination temperatures and NH3/TiCl4 molar ratios had significant impacts on the formation of crystallite nanostructures, physicochemical, as well as catalytic properties of the obtained TiO2. Under the studied conditions, calcination temperature of 600°C and NH3/TiCl4 molar ratio of 4.2 produced N-TiO2 with the best crystallinity and photocatalytic activity. The high visible light activity of the N-TiO2 nanomaterials was ascribed to the interstitial nitrogen atoms within TiO2 lattice units. These findings could provide a practical pathway capable of large-scale production of a visible light-active N-TiO2 photocatalyst.

This article presents the use of isogeometric analysis (IGA) to analyse the behaviour of the functionally graded material (FGM) plate structures with piezoelectric patches. This study investigates the effect of piezoelectric patches on the plate structure made of FGM material as a solid model. Because IGA is based on the NURBS (Non-uniform rational basis spline) approximation, this method describes the exact geometry with the higher-order functions approach. The effectiveness of the present method is to use the few degrees of freedom combining a high-order approximation function between elements to ensure the accuracy of the result, which reduces the computational time and saves the required memory. In addition, NURBS geometry has also been shown to be a viable approach due to the flexibility in mesh construction such as refinement and high-order continuity that warranty correctly the results of the problem. Based on the advantages that IGA has been proved by many previous studies, we built a three-dimensional model for plate structure consisting of upper and lower layers with piezoelectric patches, middle layer with FGM material. The results are verified and compared to the commercial Comsol software to prove the effectiveness of the method for this problem.

This paper applies isogeometric analysis (IGA) to simulate active control of the functionally graded material (FGM) plates by using piezoelectric material patches. This control helps to reduce the deflection of the plate under the effect of static load, which makes the structure more resistant to loading. IGA is built on the non-uniform rational basis spline (NURBS) basic function with many advantages such as: describing geometry exactly by approximating by higher order function and directly using this function to approach procedure. Furthermore, NURBS geometry has mesh flexibility and high continuity between elements, making the problem highly accurate. Three-dimensional model for plate-like structure consists of upper and lower layers made of piezoelectric materials, the middle layer is FGM. The obtained results will be verified with the published results to prove the efficiency of the proposed method for this problem. Through the obtained results, it is shown that IGA is used effectively for the active control problem by piezoelectric patches to reduce the displacement of FGM plates. The efficiency shown when using a small number of degrees of freedom but still ensuring the solution has accurate results when compared with the reference solution.

This paper uses numerical simulation to study amethod in combined drawing process with thinning the wall when drawing of a cylindrical cup of sheet metal. The software Deform 2D is used to examineeffect of die design parameters (inclination of die) on deformation possibility of metal. Simulation results in order to select appropriate die design parameters (conical die), to enhance the ability to deform and contribute to improve product quality.

Our study was undertaken to investigate the characteristics of Haemophilus influenzae in young children with acute lower respiratory tract infections in Nha Trang, Vietnam. The study population consisted of 116 children less than 5 years of age admitted to Khanh Hoa General Hospital due to acute lower respiratory tract infections between July 2004 and April 2005. Organisms could be detected from nasopharyngeal swabs (NP) in 72 (62.1%) of the 116 children. Haemophilus influenzae was the most common organism, and 39 strains were isolated from 39 children aged 2 to 60 months (mean age, 16 months). We examined 37 of these 39 H. influenzae strains. The serotypes of the 37 isolates were all nontypeable, and 22 strains (59.5%) were beta-lactamase producing. Polymerase chain reaction (PCR) analysis to identify resistance genes revealed that 17 strains had the TEM-1-type beta-lactamase gene alone, 6 strains had the ftsI gene with the same substitution as that in g low-beta-lactamase-negative ampicillin-resistant (g low-BLNAR) strains, and 6 strains had both the TEM-1-type beta-lactamase gene and the ftsI gene with the same substitution as that in g beta-lactamase-producing amoxicillin clavulanic acid-resistant (g BLPACR I) strains, although no BLNAR strains were found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 6 g low-BLNAR strains had five PFGE patterns and the 6 g BLPACR I strains had four PFGE patterns. Our results indicate that BLNAR strains are still not prevalent, but that g low-BLNAR and g BLPACR I strains are potentially spreading in Nha Trang, Vietnam.

Significance Shigella sonnei is a globally emerging agent of bacterial dysentery. Here, we use genomics to examine the microevolution of S. sonnei in Vietnam. We show that S. sonnei was introduced into Vietnam in the early 1980s, where it continued to evolve, spreading geographically to establish localized founder populations. The population in Ho Chi Minh City has undergone several localized clonal replacement events, during which a small number of microevolutionary changes have risen to dominance. These changes, induced by horizontal gene transfer and substitution mutations, confer high-level antimicrobial resistance and the ability to kill other gut bacteria. This work provides a unique, high-resolution insight into the microevolution of a pioneering human pathogen during its establishment in a new host population.

When modelizing cortical neuronal maps (here spiking neuronal networks) within the scope of the FACETS project, researchers in neuro-science and computer-science use NeuroML, a XML language, to specify biological neuronal networks. These networks could be simulated either using analogue or event-based techniques. Specifications include : - parametric model specification - model equation symbolic definition - formalization of related semantic aspects (paradigms, ..) and they are used by "non-computer-scientists". In this context XML is used to specify data structures, not documents. The first version of NeuroML uses Java to map XML biological data which can be later simulated within GENESIS, NEURON, etc. The second version uses tools for handling XML data, as XSL, to transform an XML file. To allow NeuroML to be used intensively within the scope of the FACETS project, we will entirely analyse the software. First we are going to evaluate this software deeply in the Technical Report section. Then we will propose a prototype to write down NeuroML code easily.