Mechanics Course Research Articles

Standardized approach for extubation during extracorporeal membrane oxygenation in severe acute respiratory distress syndrome: a prospective observational study

BackgroundExtubation during extracorporeal oxygenation (ECMO) in severe acute respiratory distress syndrome (ARDS) has not been well studied. Despite the potential benefits of this strategy, weaning from ECMO before liberation from invasive mechanical ventilation remains the most frequent approach. Our aim was to evaluate the safety and feasibility of a standardized approach for extubation during ECMO in patients with severe ARDS.ResultsWe conducted a prospective observational study to assess the safety and feasibility of a standardized approach for extubation during ECMO in severe ARDS among 254 adult patients across 4 intensive care units (ICU) from 2 tertiary ECMO centers over 6 years. This consisted of a daily assessment of clinical and gas exchange criteria based on an Extracorporeal Life Support Organization guideline, with extubation during ECMO after validation by a dedicated intensive care medicine specialist. Fifty-four (21%) patients were extubated during ECMO, 167 (66%) did not reach the clinical criteria, and in 33 (13%) patients, gas exchange precluded extubation during ECMO. At ECMO initiation, there were fewer extrapulmonary organ dysfunctions (lower SOFA score [OR, 0.88; 95% CI, 0.79–0.98; P = .02] with similar PaO2/FiO2) when compared with patients not extubated during ECMO. Extubation during ECMO associated with shorter duration of invasive mechanical ventilation (7 (4–18) vs. 32 (18–54) days; P < .01) and of ECMO (12 (7–25) vs. 19 (10–41) days; P = .01). This was accompanied by a lower incidence of hemorrhagic shock (2 vs. 11%; P = .05), but more cannula-associated deep vein thrombosis (49 vs. 31%; P = .02) and failed extubation (20 vs. 6%; P < .01). There were no increased major adverse events. Extubation during ECMO is associated with a lower risk of all-cause death, independently of measured confounding (adjusted logistic regression OR 0.23; 95% confidence interval 0.08–0.69, P = .008).ConclusionsA standardized approach was safe and feasible allowing extubation during ECMO in 21% of patients with severe ARDS, selecting patients who will have a shorter duration of invasive mechanical ventilation, ECMO course, and ICU stay, as well as fewer infectious complications, and high hospital survival.

Evaluation of teaching method for fluid mechanics course in engineering education

The professional technology training of student is the important objective of engineering education, which could present the specialized ability in the future. This task is conducted to evaluation of teaching methods for fluid mechanics course in the mechanical engineering. With the teaching practice, the advantage of teaching method is found, and the teaching quality can be revealed by the scores of integrated test. The improvement of teaching quality is contribute the development of social. According to the self-assessment, the effects of teaching method on the professional course is revealed.•The diversified teaching method is advantage to the understanding of theory and knowledge of application.•The practical training is suitable to develop the inner potential and innovation of different students.•The method allows the investigation of teaching method evaluation for the other courses with practicality.

Some remarks on projectile motion with a linear resistance force

In this article, we revisit projectile motion assuming a retarding force proportional to the velocity, . We obtain an analytical expression for the set of maxima of the trajectories, in Cartesian coordinates, without using the Lambert W function. Also, we investigate the effect of parameter k on the radial distance of the projectile showing that the radial distance oscillates from a certain critical launch angle and find an approximate expression for it. In our analysis, we consider the impact of parameter k in the kinetic energy, the potential energy, the total energy, the rate of energy loss, and the phase space. Our results can be included in an intermediate-level classical mechanics course.

Circulation of Respiratory Viruses in the City: Towards an Agent-Based Ecosystem model.

Mathematical models play an important role in management of outbreaks of acute respiratory infections (ARI). While such models are generally used to study the spread of a solitary virus, in reality multiple viruses co-circulate in the population. These viruses have been studied in detail, including the course of infection and immune defense mechanisms. We developed an agent-based model, called ABM-ARI, assimilating heterogeneous data and theoretical knowledge into a biologically motivated system, that allows to reproduce the seasonal patterns of ARI incidence and simulate interventions. ABM-ARI uses city-specific data to create a synthetic population and to construct realistic contact networks in different activity settings. Characteristics of infection, immune protection and non-specific resistance were varied between individuals to account for the population heterogeneity. For the calibration, we minimised the normalised mean absolute error between simulated and observed epidemic curves. ABM-ARI was built based on the quantitative assessment of features of predominant respiratory viruses and epidemiological characteristics of the population. It provides a good fit to the observed epidemic curves for different age groups and viruses. We also simulated one-week school closures when student absences were at or above 10%, 20% or 30% and found that only 10% and 20% thresholds resulted in a reduction of the incidence. ABM-ARI has a great potential in tackling the challenge of emerging infections by simulating and evaluating the effectiveness of various interventions.

Penerapan Media Pembelajaran Android Pada Mata Kuliah Elemen Mesin: Analisis Kebutuhan dan Kesiapan

Learning media is important in supporting an effective and interactive learning process. In the current digital era, the use of Android-based technology as a learning tool has become a major concern in improving the quality of education. This article discusses the application of Android-based learning media in the Mechanical Elements course. This research investigates the readiness and need for using Android-based Aqidah learning media. This study used a survey method with semester II student subjects from the Automotive Technology Vocational Education Study Program at Lancang Kuning University. Data was collected by filling out a questionnaire, and the results were analyzed descriptively. The research results show several important things. First, all students (100%) feel interested in Android-based learning media. Second, after understanding the use of Android learning media, around 87.6% of students acknowledged the need for this media in learning. Third, applying Aydin and Tasci's ELR model shows that readiness to use Android learning media is included in the Ready category. However, several factors need to be improved slightly. The average ELR value is 3.73, exceeding the threshold of 3.4, indicating readiness. However, it should be noted that the Self-Improvement aspect has a low ELR value, namely 3.24, indicating the need for improvement. Based on these findings,

Neuroplastic Changes Associated With Hybrid Exercise-Cognitive Training in Stroke Survivors With Mild Cognitive Decline: A Randomized Controlled Trial

Background Exercise and cognitive training have been shown to induce neuroplastic changes and modulate cognitive function following stroke. However, it remains unclear whether hybridized exercise-cognitive training facilitates cortical activity and further influences cognitive function after stroke. Objective The study aimed to investigate the effects of 2 hybridized exercise-cognitive trainings on neuroplastic changes and behavioral outcomes in stroke survivors with mild cognitive decline. Methods This study was a single-blind randomized controlled trial. Stroke survivors were randomly assigned to 1 of 3 groups: (1) sequential exercise-cognitive training (SEQ), (2) dual-task exercise-cognitive training (DUAL), or (3) control group (CON). All groups underwent training 60 min per day, 3 days per week, for a total of 12 weeks. The primary outcome was the resting-state (RS) functional connectivity (FC) in functional magnetic resonance imaging. Secondary behavioral outcomes included cognitive and physical functions. Results After 12 weeks of training, patients in the SEQ group (n = 21) exhibited increased RS FC between the left occipital lobe and posterior cingulate gyrus with right parietal lobe, compared to the DUAL (n = 22) and CON (n = 20) groups. Additionally, patients in the DUAL group showed increased FC of the left temporal lobe. However, changes in behavioral outcome measures were non-significant among the 3 groups (all P’s > .05). Conclusions This study highlights the distinct neuroplastic mechanisms associated with 2 types of exercise-cognitive hybridized trainings. The pre-post functional magnetic resonance imaging measurements illustrated the time course of neural mechanisms for cognitive recovery in stroke survivors following different exercise-cognitive training approaches. Trial registration. NCT03230253.

Brain Metabolomics in Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS).

The course of pathophysiological mechanisms involved in fragile X-associated tremor/ataxia syndrome (FXTAS) remains largely unknown. Previous proteomics and metabolomics studies conducted in blood samples collected from FMR1 premutation carriers with FXTAS reported abnormalities in energy metabolism, and precursors of gluconeogenesis showed significant changes in plasma expression levels in FMR1 premutation carriers who developed FXTAS. We conducted an analysis of postmortem human brain tissues from 44 donors, 25 brains with FXTAS, and 19 matched controls. We quantified the metabolite relative abundance in the inferior temporal gyrus and the cerebellum using untargeted mass spectrometry (MS)-based metabolomics. We investigated how the metabolite type and abundance relate to the number of cytosine-guanine-guanine (CGG) repeats, to markers of neurodegeneration, and to the symptoms of FXTAS. A metabolomic analysis identified 191 primary metabolites, the data were log-transformed and normalized prior to the analysis, and the relative abundance was compared between the groups. The changes in the relative abundance of a set of metabolites were region-specific with some overlapping results; 22 metabolites showed alterations in the inferior temporal gyrus, while 21 showed differences in the cerebellum. The relative abundance of cytidine was decreased in the inferior temporal gyrus, and a lower abundance was found in the cases with larger CGG expansions; oleamide was significantly decreased in the cerebellum. The abundance of 11 metabolites was influenced by changes in the CGG repeat number. A histological evaluation found an association between the presence of microhemorrhages in the inferior temporal gyrus and a lower abundance of 2,5-dihydroxypyrazine. Our study identified alterations in the metabolites involved in the oxidative-stress response and bioenergetics in the brains of individuals with FXTAS. Significant changes in the abundance of cytidine and oleamide suggest their potential as biomarkers and therapeutic targets for FXTAS.

Pleiotropic effects of extracellular vesicles from induced pluripotent stem cell–derived cardiomyocytes on ischemic cardiomyopathy: A preclinical study

Stem cell-secreted extracellular vesicles (EVs) play essential roles in intercellular communication and restore cardiac function in animal models of ischemic heart disease. However, few studies have used EVs derived from clinical-grade stem cells and their derivatives with stable quality. Moreover, there is little information on the mechanism and time course of the multifactorial effect of EV therapy from the acute to the chronic phase, the affected cells, and whether the effects are direct or indirect. Induced pluripotent stem cell-derived cardiomyocytes (iPSCM) were produced using a clinical-grade differentiation induction system. EVs were isolated from the conditioned medium by ultracentrifugation and characterized in silico, in vitro, and in vivo. A rat model of myocardial infarction was established by left anterior descending artery ligation and treated with iPSCM-derived EVs. iPSCM-derived EVs contained microRNAs and proteins associated with angiogenesis, antifibrosis, promotion of M2 macrophage polarization, cell proliferation, and antiapoptosis. iPSCM-derived EV treatment improved left ventricular function and reduced mortality in the rat model by improving vascularization and suppressing fibrosis and chronic inflammation in the heart. EVs were uptaken by cardiomyocytes, endothelial cells, fibroblasts, and macrophages in the cardiac tissues. The pleiotropic effects occurred due to the direct effects of microRNAs and proteins encapsulated in EVs and indirect paracrine effects on M2 macrophages. Clinical-grade iPSCM-derived EVs improve cardiac function by regulating various genes and pathways in various cell types and may have clinical potential for treating ischemic heart disease.

Exploration and Innovative Research on Ideological and Political Education in Architectural Mechanics Course

The emphasis and implementation of ideological and political education in courses lie within the courses themselves, ensuring effective education through the process of course implementation and playing a role in nurturing students. This paper explores the elements of ideological and political education in the architectural mechanics course. It provides a detailed design of ideological and political education in accordance with the course content and characteristics. Additionally, innovative designs incorporating ideological elements are introduced for parts of the course. Finally, an application exploration is conducted within the sections of the course, specifically focusing on the subtopic of “rigid frames”, with the hope of providing reference value to related courses.

Effectively integrating research argumentation in syllabus learning: A case study of reading journal articles in four fourth-year engineering fluid mechanics courses

In an emerging trend in engineering education students are engaged in the scientific discovery process through reading about research published in articles rather than textbooks. A research-based and curriculum-oriented intervention in an undergraduate course was designed to elucidate whether students can progressively gain reading skills when provided with selected articles explicitly related to fluid mechanics research. The aim was also to monitor student awareness of their own progress. A questionnaire was designed to evaluate how fourth-year fluid technology students perceived their reading skills during the teaching intervention. A progressive strategy was applied, including warm-up readings, in- and out-of-class assignments, and best practice lectures. Two parallel test exams and test readings were associated and quantitatively analyzed. Each cohort was randomly divided into two groups, and each group was assigned a different test reading before the lectures; the readings were then switched for the post-lecture assignment. The results demonstrate that the students acquired selective reading skills and awareness of accomplishment. The analyses indicated that learners gained an understanding of the core concepts and gave positive feedback on the teaching materials and schedule. These findings may serve as a guide for engineering educators to improve the preparation of undergraduate students.

Seeing the invisible: convection cells revealed with thermal imaging

Fluid instabilities are ubiquitous phenomena of great theoretical and applied importance. In particular, an intriguing example is the thermocapillary or Bénard-Marangoni instability which occurs when a thin horizontal fluid layer, whose top surface is free, is heated from below. In this phenomenon, after passing a certain temperature difference threshold, the fluid develops a regular pattern, usually hexagonal, of convection cells known as Bénard convection. In general, this pattern is not visible to the naked eye unless specific tracers are incorporated into the fluid. The use of thermal imaging is a simple alternative not only for directly observing this phenomenon but also for obtaining valuable quantitative information, such as the relationship between the critical wavelength and the thickness of the fluid layer. Here, we propose an experiment specially suited for laboratory courses in fluid mechanics or nonlinear physics that involves the use of thermal cameras, or appropriate smartphone accessories, to study Bénard convection.

Extensions to the theorems of Pappus to determine the centroids of solids and surfaces of revolution

Extensions to the first and second theorems of Pappus are presented, whereby the centroid of a surface or solid of revolution can be determined using only the geometric properties of the generating plane curve or figure and the arc of revolution. The derivations are well suited to first-year-level courses in mathematics and engineering. From a didactic perspective, the resulting formulas are simple to apply, especially since the required geometric properties are typically available in standard tables of plane sections or relatively routine to derive. Furthermore, the formulas provide a general scaffold for students to attempt problems involving axisymmetric bodies while also reinforcing and embedding their knowledge of the properties of the generating plane shapes. A selection of illustrative problems is discussed that are generally regarded to be challenging for introductory mechanics courses but for which the formulas derived in this article provide straightforward solutions.

Teaching Research of Mechanical Design Course in Vocational Colleges

The Mechanical Design course plays an important role in the education system of mechanical majors. It provides students with the necessary theoretical knowledge and practical skills of mechanical majors, and has an important role in promoting students’ professionalism and employability. The purpose of this study is to explore and provide useful ideas and suggestions to improve teaching quality of Mechanical Design courses in vocational colleges and universities, with the goal of promoting the development of vocational education. The research team firstly elaborates the research results of the previous scholars, and then puts forward six targeted suggestions to improve the teaching quality of the Mechanical Design course in view of the existing problems in the teaching of the Mechanical Design course.

The influence of cytokine reactions on the nature of the course of adaptive mechanisms in newborns of different gestational ages

Introduction. The study of the mechanisms of adaptation and consequences of deadaptation in newborns, and especially premature babies in the first days of life is an integral part of neonatal practice. The cytokine system is considered as sensitive and informative indicators of homeostatic disorders in newborns of different gestational ages.Aim. To assess the features of the early neonatal period in newborns of different gestational ages according to the nature of changes in the levels of interleukin-1, -4, -8 in the cord blood and on the 3-4th day of the infant's life.Materials and methods. 108 newborns were examined, of which 64 premature infants of the gestational age of 32 (0/7) - 36 (6/7) weeks were included in the treatment group: moderately premature infants (32 (0/7) - 33 (6/7) weeks) and late premature infants (34 (0/7) - 36 (6/7) weeks). The control group included 44 conditionally healthy full-term infants born between 37 (0/7) and 41 (6/7) week of gestation: early full-term (37 (0/7) - 38 (6/7) weeks) and full-term intants (more than 39 (0/7) weeks).Results and discussion. The full-term infants, as well as late premature infants, whose clinical status was assessed as satisfactory, usually showed minimum levels of all studied cytokines. If the early neonatal period was complicated, high levels of interleukin-1 and -8 with underlying slightly elevated levels of anti-inflammatory interleukin-4 were observed. This fact supports the activation of cytokine reactions during manifestation of pathological symptom groups generated by various organs and systems in the early neonatal period.Conclusion. The nature of cytokine reactions can serve as a marker of unfavourable course of the early neonatal period in premature infants and a criterion that justifies the implementation of necessary corrective measures.

Nonlinear oscillations for beginners. Calculating period using an elementary computational approach

Determining the period of a nonlinear oscillation is a challenging task that requires a strong mathematical background in solving nonlinear differential equations. However, the procedure can be significantly simplified using the area under the 1/|υ|= f(x) graph, where υ is the velocity of the oscillating object and x is its displacement from its equilibrium position. The proposed method requires elementary computational tools and is appropriate for determining the period of any nonlinear undamped oscillation. Characteristic examples are presented, such as the simple pendulum, the oscillation with a power-law restoring force, and the cubic-quintic Duffing oscillator. The proposed approach provides accurate results and is appropriate for introductory physics and mechanics courses.

Evaluating the learning performances for CNC machine practice in mechanical engineering degree courses based on students’ mental workload

This study evaluates the performance of learning CNC machining in mechanical engineering degree programs by assessing students’ mental workload (MWL). Both subjective (NASA-Task Load Index) and objective (increasing ratio of heart rate, IRH) evaluation methods were employed to assess the MWL of 46 students randomly assigned to two groups: a traditional training group and a combined simulation training group. The results demonstrate the significant impact of the training method on students’ MWL. Specifically, the MWL and IHR values of the combined simulation training group were 54.3 and 9.2, respectively, while those of the traditional training group were 58.3 and 13.2. Additionally, the correlation analysis showed a significant correlation between the IHR value and the MWL score of NASA-TLX. These findings suggest that implementing simulated software and the combined simulation training method effectively reduces students’ MWL, thereby promoting active knowledge acquisition. Consequently, students’ MWL can be utilized to evaluate the effectiveness of technical education with the aim of enhancing training efficiency and quality.

Research on Finite Element Technology in the Development of Mechanics Course Resources

Mechanics course in vocational colleges faces challenges such as a lack of physical equipment, insufficient hands-on experience, difficulty in visualizing abstract concepts, and cost and safety concerns associated with physical experiments. This paper explores the application of finite element technology (FET) in overcoming these challenges and improving mechanics course teaching in vocational colleges. FET is a simulation-based method that can provide extensive hands-on experience, enhance visualization of abstract concepts, and offer a cost-effective and safe learning environment. The effectiveness of FET-based mechanics education has been demonstrated in numerous studies, and the outlook for FET-based mechanics education in vocational colleges is promising.

Research on the Classroom Teaching of Engineering Mechanics in Vocational Colleges

The Engineering Mechanics course has great significance in vocational education as it affects the quality of subsequent specialized courses, such as mechanical design, control technology, and automation. However, the teaching quality of Engineering Mechanics in vocational colleges has been subpar due to the extensive knowledge points, abstract concepts, complex formulas, and other factors. This paper aims to elucidate the early-stage research conducted by scholars and analyze the primary issues in the teaching of Engineering Mechanics. Furthermore, we provide five concrete suggestions to improve the teaching quality of this course. The findings of this study may serve as a reference for innovating the teaching model of Engineering Mechanics in vocational colleges.

Neural mechanisms of event visibility in sign languages

ABSTRACT In unrelated sign languages event structure is reflected in the dynamic form of verbs, and hearing non-signers are known to be able to recognise these visual event structures. This study assessed the time course of neural processing mechanisms in non-signers to examine the pathways for incorporation of physical-perceptual motion features into the linguistic system. In an EEG study, hearing non-signers classified telic/atelic verb signs (two-choice lexical decision task). The ERP effects reflect differences in perceptual processing of verb types (early anterior ERP effects) and integration of perceptual and linguistic processing required by the task (later posterior ERP effects). Non-signers appear to segment signed input into discrete events as they try to map the sign to a linguistic concept. This might indicate the potential pathway for co-optation of perceptual features into the linguistic structure of sign languages.

Transforming Experimental Teaching of Fluid Mechanics and Heat Transfer Courses Due to the COVID-19 Pandemic

The academic situation due to the COVID-19 lockdown forced teachers to transform conventional lessons to a fully online mode. The experimental component of chemical engineering degrees is an essential part of the courses, wherein the students usually attend a pilot plant and develop practical skills in a hands-on way. The present study shows the different methodologies developed and implemented during three academic years in the experimental component of two courses: fluid mechanics and heat transfer. Therefore, the year 2018–2019 represents a conventional scenario, in which the lessons and evaluation were conducted in a traditional mode (face-to-face). Later, the cessation of on-site teaching in the middle of the year 2019–2020 compelled the teaching staff to adapt methodologies to a distance mode. This transformation was based on the creation of new learning material: explanatory videos, online seminars, solved exercises and online tests. Finally, the end of the lockdown in the year 2020–2021 allowed the return to a mixed mode (face-to-face lessons in addition to online lessons), which enabled the redesign of the experimental part of the courses. After the end of the courses, the usefulness of the implemented methodologies was evaluated by means of collecting academic marks and student surveys. The results show that, in general, the yields were similar during the three years studied, except in the lockdown period of the fluid mechanics course in which it was slightly higher than the others. With regard to the opinion of the students, their feedback about the transformations made was generally positive.