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The recent surge of online language learning services in the past decade has benefitted second language learners. However, there is a lack of understanding of whether learners, especially young learners, are engaged in online learning, and how educators can enhance the engagement of the online learning experience. This study examines an artificial intelligence (AI)-powered automated system that uses voice and facial recognition to track both teacher and learner speech, facial expressions, and interactions in real-time in a one-to-one 25-minute online English class. Each learner completed a learner engagement survey within 72 hours of the online class. Results demonstrated that young learners were highly engaged during this one-to-one online learning setting (mean = 4.5, out of 5). Learners' frontal face exposure (indicating their attentiveness during class) and English proficiency levels are significant and positive predictors of learner engagement. Teachers' total length of speech and instructional time tended toward significance in predicting learner engagement. Educational implications are discussed.

The mechanisms underlying doxorubicin (Dox) resistance in colon cancer cells are not fully understood. MicroRNA (miRNA) play important roles in tumorigenesis and drug resistance. However, the relationship between miRNA and Dox resistance in colon cancer cells has not been previously explored. In this study, we utilized microRNA array and real-time PCR to verify that miR-127, miR-195, miR-22, miR-137 were significantly down-regulated, while miR-21, miR-592 were up-regulated in both HT29/DOX and LOVO/DOX cell lines. In vitro cell viability assay showed that knockdown of miR-195 in HT29 and LOVO cells caused a marked inhibition of Dox-induced cytotoxicity. Moreover, we explored that miR-195 is involved in repression of BCL2L2 expression through targeting its 3′-untranslated region, especially the first binding site within its mRNA. Furthermore, down-regulation of miR-195 conferred DOX resistance in parental cells and reduced cell apoptosis activity, while over-expression of miR-195 sensitized resistant cells to DOX and enhanced cell apoptosis activity, all of which can be partly rescued by BCL2L2 siRNA and cDNA expression. These results may have implications for therapeutic strategies aiming to overcome colon cancer cell resistance to Dox. J. Cell. Physiol. 230: 535-545, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company [ABSTRACT FROM AUTHOR]

The spontaneous bursts of electrical activity in the developing auditory system are derived from the periodic release of adenosine triphosphate (ATP) by supporting cells in the Kölliker's organ. However, the mechanisms responsible for initiating spontaneous ATP release have not been determined. Our previous study revealed that telomerase reverse transcriptase (TERT) is expressed in the basilar membrane during the first postnatal week. Its role in cochlear development remains unclear. In this study, we investigated the expression and role of TERT in postnatal cochlea supporting cells. Our results revealed that in postnatal cochlear Kölliker's organ supporting cells, TERT shifts from the nucleus into the cytoplasm over time. We found that the TERT translocation tendency in postnatal cochlear supporting cells in vitro coincided with that observed in vivo. Further analysis showed that TERT in the cytoplasm was mainly located in mitochondria in the absence of oxidative stress or apoptosis, suggesting that TERT in mitochondria plays roles other than antioxidant or anti-apoptotic functions. We observed increased ATP synthesis, release and activation of purine signaling systems in supporting cells during the first 10 postnatal days. The phenomenon that TERT translocation coincided with changes in ATP synthesis, release and activation of the purine signaling system in postnatal cochlear supporting cells suggested that TERT may be involved in regulating ATP release and activation of the purine signaling system. Our study provides a new research direction for exploring the spontaneous electrical activity of the cochlea during the early postnatal period., Competing Interests: None

Objective: This study was designed to find out the impact of micro-ecological environment on the incidence of allergic rhinitis after developing a model of allergic rhinitis on mice., Method: Sixty mice were randomly divided into GF group (n=30) and SPF group (n=30). Mice of GF group were fed in the germ-free environment and mice of SPF group were fed in the specific pathogen-free environment. Then each group were randomly divided into model group (20 mice) and control group (10 mice). Establish allergic rhinitis model in the mice of model group using ovalbumin (OVA) at the age of 6 weeks, observe and score the corresponding symptoms and signs that could been induced. Stain with hematoxylin eosin (HE) staining method for nasal mucosa to observe the morphological changes. Using enzyme linked immunosorbent assay to detect the concentration of IgE, IFN-γ and IL-4 in the peripheral blood serum., Result: The chi square test showed that the incidence of allergic rhinithis in the mice of GF group was significantly higher than that in the SPF group (P< 0. 05). HE staining showed that the nasal mucosas of allergic rhinitis positive reaction mice were highly congestive and edematous and had a large number of inflammatory cell infiltration, while there was no abnormal morphology of nasal mucosas in mice with no allergic rhinitis reaction. EOS counting displayed that the number of eosinophilic cells in nasal mucosa of positive allergic rhinitis reaction mice was increased significantly. The concentration of IgE and IL-4 in the serum of positive allergic rhinitis reaction mice was highly increased (P <0. 05), and IFN-γ was significantly decreased (P< 0.05)., Conclusion: The difference of micro-ecological environment may play a key role in the occurrence of allergic rhinitis in mice.

Objective: To explore the effect of thymic stromal lymphopoietin (TSLP) on transformation of dendritic cell (DC) and T cell in vitro., Methods: Mouse-derived immature dendritic cells and T lymphocytes were co-cultured in vitro, which were divided into 4 groups (TSLP stimulation group, TSLP stimulation and its receptor blocking group, ovalbumin stimulation group and ovalbumin stimulation and TSLP receptor blocking group). IL-4, IL-8 and IFN-β in cell culture supernatant were detected after 2 days by ELISA. SPSS 13.0 software was used to analyze the data., Results: IL-4 levels of TSLP receptor blocking groups [(48.84 ± 1.56) pg/ml, (52.53 ± 2.36) pg/ml]were significantly lower than those of corresponding TSLP stimulation group and ovalbumin stimulation group [(72.55 ± 7.76) pg/ml, (80.47 ± 21.93) pg/ml;t = 5.994, P < 0.05;t = 2.534, P < 0.05]. However, there were not significant differences of IL-8 and IFN-β expression between corresponding two groups of whether or not TSLP receptor blocking (all P > 0.05)., Conclusion: TSLP receptor blockade in vitro can inhibit T lymphocyte transformation to Th2, which may provide a new therapeutic strategy for clinical Th2 dominant diseases such as allergic rhinitis and asthma.

Objective: To study the value of the pepsin in the sputum for diagnosing and evaluating the effectiveness of treatment of laryngopharyngeal reflux., Method: Thirty-six patients with the symptoms of dry pharynx, globus pharyngeus, excessive throat clearing, chronic cough and so on were divided into laryngopharyngeal reflux group and chronic laryngitis group by the results of therapeutic trial taking proton pump inhibitors for 3 months. The estimation of the reflux symptom index (RSI), the reflux finding score (RFS) and the detection of pepsin in the sputum were done before and after the treatment. The difference between two groups and the value of the pepsin were analyzed., Result: There were significant decreasing in RSI, RFS and pepsin level (P < 0.01) after the treatment in all patients. There were statistical differences between the laryngopharyngeal reflux group and the chronic laryngitis group in the changes of RSI and pepsin level (P < 0.01)., Conclusion: Pepsin level in the sputum might be used as a objective, effective method for diagnosing and evaluating the effectiveness in laryngopharyngeal reflux.

Objective: To isolate and culture neural stem cell (NSC) from rat olfactory epithelium and investigate the characteristics of its proliferation and differentiation., Method: NSC from postnatal three-day (P3) and zinc sulfate in situ injured adult rat olfactory epithelium was cultured with DMEM/F12 (1 : 1) containing 10% heat-inactivated fetal bovine serum. NSC and specific neural cells differentiated from NSC were identified with indirect immunofluorescence. Growth curve of NSC from P3 and adult rat and the effect of growth factors were measured using MTT method., Result: Neurosphere-forming cells were isolated and collected with diluted purification method from P3 and adult rat olfactory epithelium. These neurosphere-forming cells were nestin immuno-positive and cytokeratin immuno-negative, and could differentiated into neuronal specific enolase (NSE) immuno-positive neurons and glial fibrillary acidic protein (GFAP) immuno-positive astrocytes when transferred in MEM. The viability of NSC had no significant difference between P3 and adult rat (P > 0.05). The forming rate of neurosphere of P3 and adult rat olfactory epithelium was 0.05% - 0.10%. Fibroblast growth factor-basic could significantly promote the proliferation of NSC from epithelium, while epidermal growth factor showed no effect on the proliferation of the NSC., Conclusion: NSC with self-renewal capacity and multipotential differentiation can be isolated and cultured from P3 and adult rat olfactory epithelium.

Objective: To investigate the effect of botulinum toxin type A (BTA) on the concentration of acetylcholinesterase in nasal glands of guinea pig., Method: Eighteen male guinea pigs were randomly divided into BTA group and control group. Merocel sponge soaked with 10 U (0.2 ml) BTA was put into left nasal cavity of guinea pig under general anesthesia for one hour in BTA group. Saline replaced BTA in control group. The inferior turbinate mucosae of guinea pig were harvested under general anesthesia at 1, 2, 4 weeks after BTA treatment (3 animals in each group). The tissues were fixed in 4% paraformaldehyde and paraffin embedded. The concentration of acetylcholinesterase was determined with immunohistochemistry staining., Result: One, two weeks after local BTA application, the expression of acetylcholinesterase in nasal glandular and canal cells decreased significantly (P < 0.01). It became normal at 4 weeks after BTA treatment., Conclusion: BTA can decrease the concentration of acetylcholinesterase in nasal glands of guinea pig.