Implementing Engineering Based STEM Programs in High School Classrooms in the Republic of Korea

In 2022, South Korea announced new national curriculum that implement it from 2023. High school curriculum is about to fully implement the high school credit system, which allows students to choose subjects that suit their needs and career paths. In South Korea, technology education in middle school is a common compulsory subject, but high school technology education is a selective subject and has the name of technology and home-economics. High school technology education experiences difficulties that are not selected in many schools due to the confusion of identity of subject names and social negative perception of technology. The purpose of this is to develop an engineering education program that can be used in high school technology education and to verify its effect on students. To achieve the purpose of this study, an engineering education program was developed and students’ changes through the program were measured. This study was based on a single-group pre-post test design and was conducted with 96 10th grade students. As a result of this study, students’ engineering interest, engineering self-efficacy, and engineering career awareness were statistically significantly improved through the developed engineering education program. This study provides great implications for actively including and utilizing engineering in technology education. In addition, it will give great implication for the direction and program development of high school technology education

Effects of strobe light stimulation on postnatal developing rat retina

The nature and intensity of visual stimuli have changed in recent years because of television and other dynamic light sources. Although light stimuli accompanied by contrast and strength changes are thought to have an influence on visual system development, little information is available on the effects of dynamic light stimuli such as a strobe light on visual system development. Thus, this study was designed to evaluate changes caused by dynamic light stimuli during retinal development. This study used 80 Sprague-Dawley rats. From eye opening (postnatal day 14), half of the rats were maintained on a daily 12-h light/dark cycle (control group) and the remaining animals were raised under a 12-h strobe light (2 Hz)/dark cycle (strobe light-reared group). Morphological analyses and electroretinogram (ERG) were performed at postnatal weeks 3, 4, 6, 8, and 10. Among retinal neurons, tyrosine hydroxylase-immunoreactive (TH-IR, dopaminergic amacrine cells) cells showed marked plastic changes, such as variations in numbers and soma sizes. In whole-mount preparations at 6, 8, and 10 weeks, type I TH-IR cells showed a decreased number and larger somata, while type II TH-IR cells showed an increased number in strobe-reared animals. Functional assessment by scotopic ERG showed that a-wave and b-wave amplitudes increased at 6 and 8 weeks in strobe-reared animals. These results show that exposure to a strobe light during development causes changes in TH-IR cell number and morphology, leading to a disturbance in normal visual functions

Market efficiency and information flow between the crude palm oil and crude oil futures markets

This study analyzes the efficiency of the crude palm oil (CPO) futures market by conducting a variance ratio test and comparing it to the West Texas Intermediate (WTI) futures market. We discover that the weak-form efficient market hypothesis holds for both the CPO and WTI futures markets despite the significant difference in their liquidity. Using a scaling exponent, we investigate speculative trading activities and find that trading CPO futures in expectation of significant returns does not strongly involve a high level of risk unlike WTI futures. Our findings regarding market efficiency of the two futures markets are supported by the significant integration of the two with similar level of information flow from each market to the other. To explore the role of speculation in their market integration, we introduce a natural experimental setting using the coronavirus disease 2019 (COVID-19) pandemic, which caused a sudden decrease in the demand for fuel. The bidirectional information flow between the two markets is intensified after the COVID-19 pandemic due to lower level of speculation. The findings suggest that (i) stakeholders in the CPO market need to pay attention to the crude oil markets to anticipate its price changes, (ii) investors can use WTI futures as a hedging tool against CPO futures as long as there is mutual information flow, and (iii) regulators should carefully implement new CPO futures market policy, as either asymmetric changes in speculation or unbalanced regulation with the WTI futures market can create market distortion and regulatory arbitrage

Alveolar macrophage phagocytosis-evading inhaled microgels incorporating nintedanib-PLGA nanoparticles and pirfenidone-liposomes for improved treatment of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory and fibrotic response-driven lung disease that is difficult to cure because it manifests excessive profibrotic cytokines (e.g., TGF-β), activated myofibroblasts, and accumulated extracellular matrix (ECM). In an attempt to develop an inhalation formulation with enhanced antifibrotic efficacy, we sought to fabricate unique aerosolizable inhaled microgels (μGel) that contain nintedanib-poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs; n-PN) and pirfenidone-liposomes (p-LP). The aero-μGel was ∼12 μm, resisted phagocytosis by alveolar macrophages in vitro and in vivo, and protected inner-entrapped n-PN and p-LP. The n-PN/p-LP@aero-μGel caused enhanced/extended antifibrotic efficacy in a bleomycin-induced pulmonary fibrosis mouse presumably due to prolonged lung residence. Consequently, the results obtained by intratracheal aerosol insufflation of our n-PN/p-LP@aero-μGel twice a week were much better than those by as many as seven doses of single or mixed applications of n-PN or p-LP. The antifibrotic/pharmacokinetic results for the n-PN/p-LP@aero-μGel included reduced fibrosis progression, restored lung physiological functions, deactivated myofibroblasts, inhibited TGF-β progression, and suppressed ECM component production (collagen I and α-SMA) along with prolonged lung retention time. We believe that our n-PN/p-LP@aero-μGel increased the local availability of both nintedanib and pirfenidone due to evasion of alveolar macrophage phagocytosis and prolonged lung retention with reduced systemic distribution. Through this approach, our inhalation formulation subsequently attenuated fibrosis progression and improved lung function. Importantly, these results hold profound implications in the therapeutic potential of our n-PN/p-LP@aero-μGel to serve as a clinically promising platform, providing significant advancements for improved treatment of many respiratory diseases including IFP

Mitral and tufted cells are potential cellular targets of nitration in the olfactory bulb of aged mice.

Olfactory sensory function declines with age; though, the underlying molecular changes that occur in the olfactory bulb (OB) are relatively unknown. An important cellular signaling molecule involved in the processing, modulation, and formation of olfactory memories is nitric oxide (NO). However, excess NO can result in the production of peroxynitrite to cause oxidative and nitrosative stress. In this study, we assessed whether changes in the expression of 3-nitrotyrosine (3-NT), a neurochemical marker of peroxynitrite and thus oxidative damage, exists in the OB of young, adult, middle-aged, and aged mice. Our results demonstrate that OB 3-NT levels increase with age in normal C57BL/6 mice. Moreover, in aged mice, 3-NT immunoreactivity was found in some blood vessels and microglia throughout the OB. Notably, large and strongly immunoreactive puncta were found in mitral and tufted cells, and these were identified as lipofuscin granules. Additionally, we found many small-labeled puncta within the glomeruli of the glomerular layer and in the external plexiform layer, and these were localized to mitochondria and discrete segments of mitral and tufted dendritic plasma membranes. These results suggest that mitral and tufted cells are potential cellular targets of nitration, along with microglia and blood vessels, in the OB during aging

The Effect of a TLR4 Agonist/Cationic Liposome Adjuvant on Varicella-Zoster Virus Glycoprotein E Vaccine Efficacy: Antigen Presentation, Uptake, and Delivery to Lymph Nodes

Adjuvant CIA09, composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)-based cationic liposomes and the toll-like receptor 4 agonist de-O-acylated lipooligosaccharide (dLOS), has been shown to enhance antibody and cellular immune responses to varicella-zoster virus (VZV) glycoprotein E (gE), recombinant tuberculosis vaccine antigen, and inactivated Japanese encephalitis vaccine. In this study, we investigated its modes of action using VZV gE as a model antigen. Liposomes adsorbed gE and cooperatively with dLOS promoted endocytosis-mediated cellular uptake of gE by mouse dendritic cells in vitro. CIA09 increased the stability and cellular uptake of the antigen at the muscle site of injection, and induced immune cell recruitment and cytokine and chemokine production, which led to efficient antigen delivery to draining lymph nodes. Mouse bone marrow-derived dendritic cells, pulsed with CIA09-adjuvanted gE, efficiently presented gE to antigen-specific T cells, inducing Th1-type biased immunity, as shown by high IFN-γ production. The data indicate that liposomes and dLOS cooperate in the adjuvant activity of CIA09 by promoting antigen uptake and delivery to lymph nodes as well as antigen presentation to T cells

Age-related changes in 3-NT expression in the main OB of mice, as determined by western immunoblotting.

<p>Left panel shows the main 55-kDa band among multiple bands of representative blots for 3-NT. Right panel shows densitometric analyses of the 55-kDa-band intensity. Results are expressed as percentages (%) relative to the young (2.5 months old) mice. Data represent the mean ± SD values for 5 mice in each group. * <i>P</i><0.05.</p

Identification and confirmation of the small 3-NT-labeled puncta in the external plexiform layer (EPL) and glomerular layer (GL) using electron microscopy.

<p>A–D: EPL. A: 3-NT-labeled lipofuscin granules are seen in a tufted cell soma (TC) located in the EPL. B: An electron micrograph showing the localization of the small 3-NT-labeled puncta in the EPL. 3-NT immunoreactivity is clearly seen in the discrete membranes (arrows) and a mitochondrion (rectangle) of the mitral cell dendrite. The rectangle is magnified in <i>inset</i>. C: Another example of a 3-NT-labeled mitochondrion of the mitral cell dendrite in the EPL. D: Several 3-NT-labeled lipofuscin granules are localized within putative autophagolysosomes. <i>Inset</i> magnifies the rectangular area of a putative autophagolysosome including a lipofuscin. Note that the putative autophagolysosome is filled with lamellated structures. E–F: GL. E: A low-power electron micrograph of the GL. Small 3-NT-labeled puncta (arrows) are scattered within a glomerulus (dotted line). A labeled puncta is magnified in F. bv, blood vessel; PC, periglomerular cell. F: Higher magnification view of the rectangular region of E. 3-NT immunoreactivity is localized to the mitochondrion and the discrete membrane of the neuropil.</p

Cellular localization of 3-NT in the OB of aged mice by double-labeling immunohistochemistry with two neuronal markers, anti-NeuN (A–H) and anti-TBX21 (L–N). A–D: Glomerular layer.

<p>A: Small and large 3-NT-labeled puncta (red) are seen within the glomeruli (circles) and in the periglomerular region. B: Numerous periglomerular cells localized in the periglomerular region are labeled with anti-NeuN (green), a neuronal cell marker. C: In this merged image of A and B, few 3-NT labeled puncta are localized in NeuN-labeled periglomerular cells. D: A transmission light micrograph overlaid with C. E–H: Mitral cell layer (MCL) and 2 adjacent regions of the external plexiform layer (EPL) and the inner plexiform layer (IPL). E: Large 3-NT-labeled puncta are clearly seen on the border of the MCL and EPL. F: Many NeuN-labeled granule cells located in the MCL are observed. G: In this merged image of E and F, large 3-NT-labeled puncta are not localized to NeuN-labeled granule cells. H: In a transmission light micrograph overlaid with G, the large 3-NT-labeled puncta are exclusively localized externally to putative NeuN-negative mitral cells (asterisks). The rectangular area is magnified in I–K. I–K: A mitral cell. I: In a transmission light micrograph overlaid with red immunofluorescence, the 3-NT-labeled puncta with triangular shape is clearly seen in the apical portion of a putative mitral cell. J: In the confocal image using the red channel for 3-NT immunoreactivity, the labeled triangular puncta is outlined. K: A transmission light micrograph overlaid with the 3-NT puncta area (red) shown in J, a putative mitral cell (black outline), its nucleus (blue), and nucleolus (yellow). This image demonstrates that 3-NT is localized to the apical region of the mitral cell somata. IPL, inner plexiform layer. L–N: MCL and EPL. L: Similar to E, many large 3-NT-labeled puncta are observed in the MCL and EPL. M: Several somata located in the MCL and EPL are labeled with anti-TBX21 (green), a mitral and tufted cell marker. N: In this merged image of L and M, most of the large 3-NT labeled puncta (arrows) in the MCL are localized close to TBX21-labeled mitral cell somata. In the EPL, a few labeled puncta (double arrowheads) are localized close to TBX21-labeled tufted cell somata.</p