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Objectives: To investigate clinical and paraclinical characteristics of patients undergoing concomitant mitral and aortic valve replacement with On-X mechanical valve at Bach Mai Hospital. Subjects and methods: This was a non-controlled, prospective, descriptive study on 100 patients with severe aortic and mitral diseases undergoing concomitant aortic and mitral valve replacement with On-X valve. Clinical and paraclinical parameters were selected based on Vietnam National Heart Association and ACC/AHA guidelines. Results: Clinical manifestations included history of rheumatic heart disease (70.0%), NYHA class II (36.0%), NYHA class III (64.0%), atrial fibrillation (67.0%). Echocardiography showed dilated left ventricle (LVEDd 55.2 ± 8.9 mm, LVEDs 37.3 ± 8.1 mm), preserved left ventricular ejection fraction (63.9 ± 9.5%), moderately pulmonary arterial hypertension (47.2 ± 13.8 mmHg), and dilated left atrium (53.8 ± 10.5 mm). Conclusion: Most patients undergoing concomitant On-X aortic and mitral prosthetic valve replacement presented with moderate and severe heart failure, dilated left ventricle and left atrium, and increased pulmonary arterial pressure. * Keywords: Mitral and aortic valve replacement; On-X valve.

Inflammatory pseudotumor of the liver (IPTL) is a rare benign lesion characterizedby chronic infiltration of inflammotory cells and an areas of fibrosis that sometimesmimics a malignant lesion, first reported by Pack and Baker in 1953. The etiologyand pathogy still remain unknown. Clinical and laboratory features are not specific.The treatment attitude is still controversial. We report 3 cases of IPTL who weretreated surgically with preoperative diagnosis of ruptured liver abscess or a malignantliver tumor. The postoperative patient was safe and the pathological results wereinflammotory pseudotumor of the liver. Conclusion: IPTL is a benign lesion thatcan be confused with other diagnoses of the liver. The treatment of choice is stillsurgical resection, and this is especially true for patients with severe symptomsor an indeterminate diagnosis.

Objectives: To study an algorithm to control a bipedal robot to walk so that it has a gait close to that of a human. It is known that the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm is a highly efficient algorithm with a few changes compared to the popular algorithm — the commonly used Deep Deterministic Policy Gradient (DDPG) in the continuous action space problem in Reinforcement Learning. Methods: Different from the usual sparse reward function model used, in this study, a reward model combined with a sparse reward function and dense reward function will be proposed. The application of the TD3 algorithm together with the proposed reward function model to control a bipedal robot model with 6 degrees of freedom will be presented. The training process is simulated in Gazebo/Robot Operating System (ROS) environment. Finding: The results show that, when choosing a reward model combined with a sparse reward function and a dense reward function suitable for the robot model, will help it learn faster and achieve better results. The biped robot can walk straight with an almost human-like gait. In the paper, the results from the TD3 algorithm combined with the proposed reward model are also compared with the results from other algorithms. Novelty: Applying the TD3 algorithm combined with the proposed reward model for the 6-DOF biped robot and simulating the robot’s gait in Gazebo/ROS environment, ROS is a middleware that can be used to control a robot in a real environment in the future. Keywords: TD3; biped robot; reinforcement learning; ROS; Gazebo

In response to the long-term challenges of skills shortages and mismatches, many countries worldwide have made significant investments in STEM education. However, to obtain a comprehensive understanding of the progress of global research on the implementation of STEM education, it is essential to compile case studies on STEM education. Therefore, we conducted a bibliometric analysis of 750 publications from Scopus database to assess the bibliographic content of case studies on STEM education from 2006 to 2022. Our main findings show that the first case study on STEM education dates back to 2006, and research in this direction has grown enormously and continuously over the last five years (counting for 72.9%). The most influential articles in the field are cited mainly in the background citations section and help provide an initial perspective for readers to understand the insights discussed later in the study. The most popular journals publishing case studies in STEM education are of good quality, ranking highly in Scopus and Web of Science categories. The analysis results show three main research directions: STEM education in higher education, STEM education expands to STEAM, and STEM education activities in K12-education.

Работа посвящена изучению корреляций между основными хозяйственными признаками партенокарпического огурца при выращивании в открытом грунте. В 2019–2020 годах в ФГБОУ ВО РГАУ–МСХА имени К.А. Тимирязева были заложены полевые опыты с 26 F1партенокарпическими гибридами корнишонного типа методом рендомизированных повторений в трех повторностях по 10 растений в каждой. Огурец выращивали на участке с окультуренными среднесуглинистыми дерново-подзолистыми почвами. Предшественниками в 2019 году была белокочанная капуста, в 2020 году - лук репчатый. Технология возделывания – в соответствии с требованиями, принятыми в регионе. Среднесуточная температура воздуха и количество осадков с июня по август 2019–2020 годов были выше среднемноголетних показателей, что благоприятно отразилось на росте и плодоношении растений огурца. Оценку хозяйственно ценных признаков выполняли по общепринятой методике. Методом корреляционного анализа выявлена достоверно высокая связь урожайности со скороспелостью (r = 0,55…0,62) и массой зеленца (r = 0,61…0,73). Очень сильная корреляция между общей урожайностью и числом товарных плодов на растении (r = 0,69…0,85); урожайностью корнишонов и числом корнишонов с растения (r = 0,75…0,96) позволяет проводить отбор высокоурожайных комбинаций по количеству плодов с растения, что значительно упрощает оценку урожайности селекционного материала. Наличие очень высокой обратной связи (r = –0,89…–0,92) между скороспелостью и раннеспелостью, выраженной в сутках до начала плодоношения, указывает на возможность проведения отбора скороспелых образцов партенокарпического огурца женского типа цветения по времени формирования первых плодов. Не было выявлено корреляции между числом боковых побегов на растении, поражением пероноспорозом и урожайностью. The work is devoted to the study of correlations between the main economic characteristics of parthenocarpic cucumber when grown in the open ground. In 2019–2020, experiments were conducted with 26 F1 parthenocarpic gherkin hybrids using the method of randomized repetitions in three repetitions of 10 plants each in open ground conditions in the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy, Moscow, Russian Federation. Cucumber was grown on a plot with cultivated medium-loamy sod-podzolic soils. The predecessors in 2019 were white cabbage, in 2020 onions. Agrotechnics of cultivation is carried out in accordance with the requirements adopted in the region. The average daily air temperature and precipitation from June to August 2019–2020 was higher than the average annual indicators, which favorably affected the growth and fruiting of cucumber plants. The assessment of economically valuable features was carried out according to the generally accepted methodology. The method of correlation analysis revealed a significantly high relationship between yield and early yield (r = 0.55…0.62) and the fruit weight (r = 0.61…0.73). A very strong correlation between the total yield and the number of marketable fruits per plant (r = 0.69…0.85); the yield of gherkins and the number of gherkins per plant (r = 0.75…0.96) allows selecting high-yielding combinations by the number of fruits per plant, which greatly simplifies the assessment of the yield of breeding material. The presence of a very high feedback (r = –0.89…–0.92) between early yield and earliness expressed in days to harvest indicates the possibility of selecting early-yielding samples of parthenocarpic cucumber at the time of formation of the first fruits. There was no correlation between the number of lateral shoots on the plant, peronosporosis damage and yield.

Antibiotics used in livestock production offer various benefits as an antimicrobial agent, growth promoter, and feed effective improvement. However, the abuse of antibiotics leads to antibiotic resistance which may seriously threaten human and animal welfare, and growing levels of antibiotics or antibiotic-resistant bacteria in the environment increase the numbers of drug-resistant infection outbreaks. Therefore, many detection methods have been being developed to quickly assess antibiotic content and its residues in foods. Among many analytical methods, the aptamer-based biosensor has considerable attention for its outstanding advantages such as high specificity, high sensitivity, and good selectivity. We use the ELAA (Enzyme-Linked Aptamer Assay) method - a variant of ELISA - which has a high affinity with neomycin. Firstly, we investigated different buffers to create the Neo-BSA complex. As result, 2-(N-morpholino) ethanesulfonic acid (MES) buffer pH 7 was found with the best results. Next, to help the Neo-BSA complex be fixed well on polystyrene wells, we surveyed various buffers and found the coating buffer (50mM Bicarbonate buffer, pH 9.6) rated as the most suitable for this process. In addition, the quality of the kit is also assessed through competitive ELAA reaction components. Therefore, we have investigated and optimized conditions such as aptamer concentration 25 nM in PBS buffer, and the biotinized aptamers did not need heat treatment prior to joining the reaction. From the results, we have successfully developed a calibration curve for antibiotic residue in milk using the ELAA technique, linear range 0,1 ng/mL and 100 ng/mL. Then, we initially surveyed 20 milk samples found that the ELAA method was consistent with the results from LC-MS/MS was obtained showing no difference between the two methods. We continued to test the samples to determine the kit’s sensitivity and specificity. The results showed that the kit has a specificity and sensitivity of 100%. Finally, LOD and LOQ value had xavg = 0.448; SD = 0.22, LOD = xavg + 3SD = 1.11 (ng / ml); LOQ = x tb + 10SD = 2.65 (ng / mL). We will continue to optimize the kit before being brought to the market.