Educational values and challenges of i-STEM project-based learning: A mixed-methods study with data-transformation design.

Integrated science, technology, engineering, and mathematics (STEM) embedding project-based learning (i-STEM PjBL) is still faced with challenges, and its educational values have not been revealed, which is what the study aimed to explore. Participants consisted of 48 freshmen from a senior high school, including 27 male students and 21 female students. The open-ended questionnaire and the interview for the students were administrated after the i-STEM PjBL. The qualitative data were converted into quantitative data counted by the occurrence frequencies of the codes. The results based on the integration and comparison of the open-ended questionnaire and interview outcomes showed that i-STEM PjBL provided students with positive educational values (including learning acquisition, performance, and perception), but there were also learning challenges in the process. Learning acquisition focused on the basic structure and components of a robot, principles of robot motion, hull structure, principles of sailboat navigation, and skills of designing and assembling sailboats. Learning performance referred that students were satisfied with their hands-on performances and confident of their abilities to perform better in similar disciplines, but did not learn well on programming. Learning perception indicated that students felt interested in i-STEM PjBL materials could acquire knowledge and skills from various fields, PjBL could be helpful to complete works, and principles could be helpful in practice, while programming design learning materials were not enough. Learning challenges indicated that students were unfamiliar with the usage of tools and hands-on operation, and they also felt challenged by programming. Students' feedback can be taken as references to modify and improve i-STEM PjBL and the materials in the future.

Spontaneous analogising caused by text stimuli in design thinking: differences between higher- and lower-creativity groups.

Understanding the cognitive processes used in creative practices is essential to design research. In this study, electroencephalography was applied to investigate the brain activations of visual designers when they responded to various types of word stimuli during design thinking. Thirty visual designers were recruited, with the top third and bottom third of the participants divided into high-creativity (HC) and low-creativity (LC) groups. The word stimuli used in this study were two short poems, adjectives with similar meanings, and adjectives with opposing meanings. The derived results are outlined as follows: (1) the brain activations of the designers increased in the frontal and right temporal regions and decreased in the right prefrontal region; (2) the negative association between the right temporal and middle frontal regions was notable; (3) the differences in activations caused by distinct word stimuli varied between HC and LC designers; (4) the spectral power in the middle frontal region of HC designers was lower than that of LC designers during the short love poem task; (5) the spectral power in the bilateral temporal regions of HC designers was higher than that of LC designers during the short autumn poem task; (6) the spectral power in the frontoparietal region of HC designers was lower than that of LC designers during the similar concept task; and (7) the spectral power in the frontoparietal and left frontotemporal regions of HC designers was higher than that of LC designers during the opposing concept task.

Catalytic pyrolysis of sugarcane bagasse by using microwave heating.

The aim of this study was to research the catalytic effects on the microwave pyrolysis of sugarcane bagasse and thus to discuss the reaction performance, product distribution, and kinetic analysis. With the addition of metal-oxides served as catalysts, reaction results such as mass reduction ratio and reaction rate increased, even the maximum temperature decreased. Adding either NiO or CaO slightly increased the production of H2, while adding either CuO or MgO slightly decreased it. The addition of either CaO or MgO enhanced the gaseous production, and either NiO or CuO addition enhanced the liquid production. There could be several secondary reactions such as self-gasification and interactions among the gases originally produced during the pyrolysis stage to alter the composition of gaseous product and the final three-phase product distribution. The catalyst addition slightly increased the activation energy but greatly increased the pre-exponential factor.

Molecular mechanisms underlying the anti-proliferative and anti-migratory effects of folate on homocysteine-challenged rat aortic smooth muscle cells.

BACKGROUND AND PURPOSE: Homocysteine is an intermediate product formed during the metabolism of methionine, and is increased in cells with folate deficiency. Patients with hyperhomocysteinemia tend to develop cardiovascular disease. Here, we have examined the molecular mechanisms underlying the anti-proliferative and anti-migratory effects of folate on homocysteine-challenged rat aortic smooth muscle cells (RASMCs). EXPERIMENTAL APPROACH: Cultures of RASMC were challenged with homocysteine and then incubated with folate added. Changes in p21/p27, AKT and RhoA were followed by RT-PCR, Western blotting and immunocytochemistry. Transfection and anti-sense techniques were also used. Cell viability, growth and migration were measured. KEY RESULTS: Folate up-regulated p21/p27 through a Src/ERK-dependent mechanism that accounted for its anti-proliferative effects on RASMC. Folate protected RASMC from the effects of homocysteine by reducing AKT1, focal adhesion kinase (FAK), paxillin, and p190RhoGAP activation/phosphorylation, along with cytosolic levels of p21 and p27, and increasing RhoA activation. Overexpression of AKT1, but not of AKT2, induced p21/p27 phosphorylation and increased cytosolic p21/p27 levels, as did homocysteine treatment. By contrast, and similarly to folate treatment, transfection with dominant negative (DN) AKT1 counteracted these effects. Additionally, AKT was shown to be an upstream target of FAK activation. In RASMC overexpressing constitutively active RhoA, activation of RhoA mediated the anti-migratory effects of folate. Addition of Y27632 (a RhoA inhibitor) and DNRhoA counteracted the anti-migratory effects, confirming RhoA involvement. CONCLUSION AND IMPLICATIONS: Folate was anti-proliferative and anti-migratory in homocysteine-challenged RASMC. Mechanisms underlying folate-mediated protection against the proatherosclerotic effects of homocysteine have been delineated.

Catalytic and atmospheric effects on microwave pyrolysis of corn stover.

Corn stover, which is one of the most abundant agricultural residues around the world, could be converted into valuable biofuels and bio based products by means of microwave pyrolysis. After the reaction at the microwave power level of 500W for the processing time of 30min, the reaction performance under N2 atmosphere was generally better than under CO2 atmosphere. This may be due to the better heat absorbability of CO2 molecules to reduce the heat for stover pyrolysis. Most of the metal-oxide catalysts effectively increased the maximum temperature and mass reduction ratio but lowered the calorific values of solid residues. The gas most produced was CO under N2 atmosphere but CO2 under CO2 atmosphere. Catalyst addition lowered the formation of PAHs and thus made liquid products less toxic. More liquid products and less gas products were generated when using the catalysts possibly due to the existence of the Fischer-Tropsch synthesis.