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Learning a second language (L2) presents a significant challenge to many people in adulthood. Platforms for effective L2 instruction have been developed in both academia and the industry. While real-life (RL) immersion is often lauded as a particularly effective L2 learning platform, little is known about the features of immersive contexts that contribute to the L2 learning process. Immersive virtual reality (iVR) offers a flexible platform to simulate an RL immersive learning situation, while allowing the researcher to have tight experimental control for stimulus delivery and learner interaction with the environment. Using a mixed counterbalanced design, the current study examines individual differences in L2 performance during learning of 60 Mandarin Chinese words across two learning sessions, with each participant learning 30 words in iVR and 30 words via word–word (WW) paired association. Behavioral performance was collected immediately after L2 learning via an alternative forced-choice recognition task. Our results indicate a main effect of L2 learning context, such that accuracy on trials learned via iVR was significantly higher as compared to trials learned in the WW condition. These effects are reflected especially in the differential effects of learning contexts, in that less successful learners show a significant benefit of iVR instruction as compared to WW, whereas successful learners do not show a significant benefit of either learning condition. Our findings have broad implications for L2 education, particularly for those who struggle in learning an L2.

Flavonoids are structurally diverse and the most ubiquitous groups of dietary polyphenols distributed in various fruits and vegetables. In this study, the interaction between five flavonoids, namely formononetin-7-O-β-D-glucoside, calycosin- 7-O-β-D-glucoside, calycosin, rutin, and quercetin, and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorbance spectroscopy. In the discussion, it was proved that the fluorescence quenching of BSA by flavonoids was a result of the formation of a flavonoid–BSA complex. Fluorescence quenching constants were determined using the Stern-Volmer and Lineweaver-Burk equations to provide a measure of the binding affinity between the flavonoids and BSA. The binding constants ranked in the order quercetin > rutin > calycosin > calycosin-7-O-β-D-glucoside ≈ formononetin-7-O-β-D-glucoside. The results of thermodynamic parameters ΔG, ΔH, and ΔS at different temperatures indicated that the hydrophobic interaction played a major role in flavonoid–BSA association. The distance r between BSA and acceptor flavonoids was also obtained according to Förster’s theory of non-radiative energy transfer.

IMPORTANCE Ocular manifestations and outcomes in children with confirmed coronavirus disease 2019 , relevant affecting factors, and differences in ocular disease between children and adults have yet to be fully understood. OBJECTIVE To investigate ocular manifestations and clinical characteristics of children with laboratory-confirmed COVID-19. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study was conducted at Wuhan Children's Hospital in Wuhan, China. Children with COVID-19 confirmed by severe acute respiratory syndrome coronavirus disease 2 nucleic acid tests of upper respiratory tract specimens between January 26 and March 18, 2020, were included. MAIN OUTCOMES AND MEASURES Onset clinical symptoms and duration, ocular symptoms, and needs for medication. RESULTS A total of 216 pediatric patients were included, among whom 134 (62%) were boys, with a median (interquartile range) age of 7.25 (2.6-11.6) years. Based on the exposure history, 193 children (89.4%) had a confirmed (173 [80.1%]) or suspected (20 [9.3%]) family member with COVID-19 infection. The most common symptoms among symptomatic children were fever (81 [37.5%]) and cough (79 [36.6%]). Of 216 children, 93 (43.1%) had no systemic or respiratory symptoms. All children with mild (101 [46.8%]) or moderate (115 [53.2%]) symptoms recovered without reported death. Forty-nine children (22.7%) showed various ocular manifestations, of which 9 had ocular complaints being the initial manifestations of COVID-19. The common ocular manifestations were conjunctival discharge (27 [55.1%]), eye rubbing (19 [38.8%]), and conjunctival congestion (5 [10.2%]). Children with systemic symptoms (29.3% vs 14.0%; difference, 15.3%; 95% CI, 9.8%-20.7%; P = .008) or with cough (31.6% vs 17.5%; difference, 14.1%; 95% CI, 8.0%-20.3%; P = .02) were more likely to develop ocular symptoms. Ocular symptoms were typically mild, and children recovered or improved. CONCLUSIONS AND RELEVANCEIn this cross-sectional study, children hospitalized with COVID-19 in Wuhan, China, presented with a series of onset symptoms including fever, cough, and ocular manifestations, such as conjunctival discharge, eye rubbing, and conjunctival congestion. Patients' systemic clinical symptoms or cough were associated with ocular symptoms. Ocular symptoms recovered or improved eventually.