Universal Reasons for Low Participation in Chinese and Western Undergraduate Classrooms

This study regards low classroom participation as a global issue and investigates the universal reasons for this problem shared by the undergraduate students in China and in the west. Participating in class discussions and asking questions are instrumental for effective learning. This study regards low classroom participation as the phenomenal where students do not ask or answer questions during a lesson. The research was conducted by combining profound experiences and insights developed as an undergraduate student in the University of Waterloo and a teaching assistant in Soochow University with the understanding of both Chinese academic articles and western academic articles about this topic. This study reveals the reason why Chinese and western undergraduate classrooms experience low classroom participation is that their stakeholders focus on the competing goals. This study defines the stakeholders as the instructors, students and the post-secondary institutions

Influence of gastrointestinal digests of glycated whey protein on the hormone secretion of enteroendocrine cells

The present research used two α-dicarbonyl compounds, glyoxal and methylglyoxal and whey protein as subjects, and evaluated the alterations of physicochemical properties, structure, and digestibility of whey protein throughout the glycation process. The STC-1 cells were used as a model to investigate the implications of glycation on the protein nutrition sensing of enteroendocrine cells. Results showed that glycation substantially enhanced the surface hydrophilicity and solubility of whey protein. Additionally, the incorporation of sugar chain structure introduced steric hindrance, facilitating the binding of the free amino group of lysine and resulting in the formation of macromolecular crosslinking glycation structures. These structures potentially hindered the function of gastrointestinal digestive enzymes, thus reducing the degree of digestion. Furthermore, the gastric and intestinal digests of glycated whey protein variably modulated the intestinal hormone secretion of STC-1 cells and elevated the mRNA levels of pertinent hormones. Derived patterns of the effect of the gastrointestinal digestion products of glycated proteins on the level of hormone secretion in enteroendocrine cells

Optimizing the Extraction of Polysaccharides from Bletilla ochracea Schltr. Using Response Surface Methodology (RSM) and Evaluating their Antioxidant Activity

Bletilla ochracea Schltr. polysaccharides (BOP) have a similar structure to Bletilla striata (Thunb.) Reichb.f. (Orchidaceae) polysaccharides (BSP). Therefore, BOP can be considered as a substitute for BSP in the food, pharmaceuticals and cosmetics fields. To the best of our knowledge, little information is available regarding the optimization of extraction and antioxidant activity of BOP. In this study, response surface methodology (RSM) was firstly used for optimizing the extraction parameters of BOP. The results suggested that the optimal conditions included a temperature of 82 °C, a duration of 85 min and a liquid/material ratio of 30 mL/g. In these conditions, we received 26.45% ± 0.18% as the experimental yield. In addition, BOP exhibited strong concentration-dependent antioxidant abilities in vitro. The half-maximal effective concentration (EC50) values of BOP against 1,1-diphenyl-2-picrylhydrazyl (DPPH·), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonate) (ABTS+·), hydroxyl (·OH) and superoxide anion (·O2−) radicals and ferrous ions (Fe2+) were determined as 692.16, 224.09, 542.22, 600.53 and 515.70 µg/mL, respectively. In conclusion, our results indicate that BOP can be a potential natural antioxidant, deserving further investigation

Screening of Microbial Strains Used to Ferment <i>Dendrobium officinale</i> to Produce Polysaccharides, and Investigation of These Polysaccharides’ Skin Care Effects

The microbial fermentation of plants is a promising approach for enhancing the yield of polysaccharides with increased activity. In this study, ten microbial strains, Lactiplantibacillus plantarum CCFM8661, Limosilactobacillus reuteri CCFM8631, Lactobacillus helveticus M10, Lacticaseibacillus rhamnosus CCFM237, Lactilactobacillus sakei GD17-9, Lacticaseibacillus casei CCFM1073, Bacillus subtilis CCFM1162, Bacteroides cellulosilyticus FTJSI-E-2, Bacteroides stercoris FNMHLBEIK-4, and Saccharomyces cerevisiae HN7-A5, were used to ferment Dendrobium officinale. The skin care activity of the resulting polysaccharides (F-DOP) was evaluated in cultured HaCaT and RAW 264.7 cells, and a mouse model. The results indicated that D. officinale medium promoted strain proliferation, and fermentation significantly enhanced polysaccharide yield (up to 1.42 g/L) compared to that without fermentation (0.76 g/L). Moreover, F-DOPs, especially after CCFM8631 fermentation, exhibited an excellent ability to attenuate sodium dodecyl sulfate-induced HaCaT cell injury (from 69.04 to 94.86%) and decrease nitric oxide secretion (from 42.86 to 22.56 μM) in lipopolysaccharide-stimulated RAW 264.7 cells. In vivo, CCFM8631-FDOP reduced the transdermal water loss rate, skin epidermal thickness, and interleukin 6, and enhanced the expression of filaggrin, improving 2,4-dinitrofluorobenzene-induced skin damage. Therefore, considering viable cell counts, polysaccharide yields, and skin care efficacy in vitro and in vivo, CCFM8631 is the most suitable strain to enhance the skin care activity of DOPs and possesses promising potential for applications in the cosmetics industry

Fabrication of nanochannels via near-field electrospinning

A simple and low-cost method is suggested to fabricate nanochannels via Near-Field Electrospinning (NFES). In this process, orderly and patterned nanofibers direct-written by NFES are used as sacrificial templates. Well-defined nanochannels are available after the removal process of both sacrificial fibers and material coating over the fibers. The sacrificial fiber, controlled by NFES, dominates the channel geometry. The channel width ranges from 133 nm to 13.54 mu m while the applied voltage increases from 1.2 kV to 2.5 kV. Complicated wave-shape and grid pattern channels are presented under a corresponding movement of substrate. This method integrates electrospinning with conventional MEMS fabrication technology and has a potential in micro/nano manufacturing.National Natural Science Foundation of China [51035002, 51105320]; Fundamental Research Funds for the Central Universities [2010121039

Cyanidin Alleviated CCl₄-Induced Acute Liver Injury by Regulating the Nrf2 and NF-κB Signaling Pathways

Acute liver injury has multiple causes and can result in liver failure. In this study, we evaluated the hepatoprotective ability of cyanidin (Cy) and investigated its associated mechanisms. Cy administration significantly and dose-dependently ameliorated acute liver injury induced by carbon tetrachloride (CCl4). High-dose Cy showed effects comparable to those achieved by the positive control (silymarin). Severe oxidative stress and inflammatory responses in the liver tissue induced by CCl4 were significantly mitigated by Cy supplementation. The total antioxidant capacity and the activity of superoxide dismutase, catalase, and glutathione peroxidase were increased and the content of malondialdehyde, lipid peroxide, tumor necrosis factor α, interleukin-1β, and interleukin-6 were decreased. Additionally, the Nrf2 and NF-κB signaling pathways, which regulate antioxidative and inflammatory responses, were analyzed using quantitative real-time polymerase chain reaction and western blot assay. Cy treatment not only increased Nrf2 transcription and expression but also decreased NF-κB signaling. Moreover, molecular docking simulation indicated that Cy had high affinity for Keap1 and NF-κB/p65, which may promote nuclear translocation of Nrf2 and inhibit that of NF-κB. In summary, Cy treatment exerted antioxidative and anti-inflammatory effects and ameliorated liver injury by increasing Nrf2 and inhibiting the NF-κB pathway, demonstrating the potential of Cy as a therapeutic agent in liver injury

Physicochemical Properties and Chemical Stability of β-Carotene Bilayer Emulsion Coated with Bovine Serum Albumin and Arabic Gum Compared to Monolayer Emulsions

β-carotene is a lipophilic micronutrient that is considered beneficial to human health. However, there are some limitations in utilizing β-carotene in functional foods or dietary supplements currently because of its poor water dispersibility and chemical stability. A new type of β-carotene bilayer emulsion delivery system was prepared by a layer-by-layer electrostatic deposition technique, for which were chosen bovine serum albumin (BSA) as the inner emulsifier and Arabic gum (GA) as the outer emulsifier. The physicochemical properties of bilayer emulsions were mainly characterized by droplet size distribution, zeta potential, rheological behavior, Creaming Index (CI), and encapsulation ratio of β-carotene. Besides this, the effects of processing conditions (pH, thermal treatment, UV radiation, strong oxidant) and storage time on the chemical stability of bilayer emulsions were also evaluated. The bilayer emulsion had a small droplet size (221.27 ± 5.17 nm) and distribution (PDI = 0.23 ± 0.02), strong zeta potential (−30.37 ± 0.71 mV), good rheological behavior (with the highest viscosity that could reduce the possibility of flocculation) and physical stability (CI = 0), high β-carotene encapsulation ratio (94.35 ± 0.71%), and low interfacial tension (40.81 ± 0.86 mN/m). It also obtained better chemical stability under different environmental stresses when compared with monolayer emulsions studied, because it had a dense and thick bilayer structure

Design and simulation of fully-symmetrical resonant pressure sensor

Conference Name:7th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2012. Conference Address: Kyoto, Japan. Time:March 5, 2012 - March 8, 2012.IEEE; IEEE Nanotechnology Council; The Murata Science Foundation; The Kyoto University Foundation; Office of Naval Research GlobalA fully-symmetrical resonant pressure sensor based upon lateral drive is presented, which can avoid stress concentration that arises from temperature or vacuum packaging. Unlike conventional driving method, resonant structure with laterally driven comb capacitance allows the linear characteristic of driving force and also obtains high quality factor for its slide-film air damping. Furthermore, the detection sensitivity of the device can be improved by using differential capacitance, which will reduce shared-frequency interference phenomenon at the same time. According to the FEM analysis, the structural parameters of resonant pressure sensor are optimized. Meanwhile, the pressure sensitivity of the sensor has designed to be 22.602Hz/kPa for a 18渭m thick diaphragm over a pressure range of 550kPa. From temperature simulation, the temperature coefficient of sensor is -1.8233Hz/掳C in the range of -20掳C鈭?0掳C without any temperature compensation. Finally, the frequency domain characteristics have been confirmed and the quality factors of sensor under different damping ratios are identified, it offers reliable reference for the choice of vacuum in resonant pressure sensor packaging. 漏 2012 IEEE