Organic-inorganic hybrid two-dimensional (2D) perovskites have recently attracted great attention in optical and optoelectronic applications due to their inherent natural quantum-well structure. We report the growth of high-quality millimeter-sized single crystals belonging to homologous two-dimensional (2D) hybrid organic-inorganic Ruddelsden-Popper perovskites (RPPs) of (BA)(MA) PbI ( n = 1, 2, and 3) by a slow evaporation at a constant-temperature (SECT) solution-growth strategy. The as-grown 2D hybrid perovskite single crystals exhibit excellent crystallinity, phase purity, and spectral uniformity. Low-threshold lasing behaviors with different emission wavelengths at room temperature have been observed from the homologous 2D hybrid RPP single crystals. Our result demonstrates that solution-growth homologous organic-inorganic hybrid 2D perovskite single crystals open up a new window as a promising candidate for optical gain media.

3؉ also inhibits fibril formation; however, the annular oligomers co-exist in the aggregation pathway. In conclusion, Zn 2؉ , Cu 2؉ , Fe 3؉ , and Al 3؉ adopt distinct folding and aggregation mechanisms to affect A␤, where A␤ destabilization promotes annular protofibril formation. Our study facilitates the understanding of annular A␤ oligomer formation upon metal ion binding. The brain deposition of amyloid plaques composed of A␤2 is the pathological hallmark of AD (1, 2). A␤ is generated from sequential cleavages of amyloid precursor protein by ␤-and ␥-secretases (3, 4). The predominant A␤ isoforms are A␤40 and A␤42, which differ in two residues at the C terminus, where A␤42 is less abundant but more neurotoxic (5-8). A␤ is a natively unfolded protein prone to aggregating into cross-␤-amyloid fibrils through a nucleation-dependent polymerization pathway (9). A␤ aggregation is considered the major culprit in AD, in which the A␤ oligomers, but not fibrils, better correlate with cognitive impairment and synaptic dysfunction (10). A␤ oligomers are referred to various different metastable intermediates found in the aggregation, including low molecular weight oligomers, spherical oligomers, A␤-derived diffusible ligands, globulomers, annular protofibrils, A␤56*, and curvilinear protofibrils (11)(12)(13)(14)(15)(16)(17)(18) (24 -25). These facts indicate that the elevation of the metal ions is relevant to AD pathology.A␤ is able to bind to the metal ions (22, 23). A␤ ion coordination, binding affinity, and induced aggregation have been studied intensively in various conditions; however, the results and mechanisms remain inconclusive. A␤-Cu 2ϩ coordination involves three intramolecular histidines (i.e. His-6, His-13, and His-14) in A␤ (26 -28), with the fourth coordinate being either the amino group of the N terminus (29), an oxygen from Tyr-10 (30), or an oxygen from Glu-3 (29). The A␤-Zn 2ϩ complex is reportedly more complicated. A similar coordination with Cu 2ϩ has been proposed for Zn 2ϩ using the three histidines and the N terminus (31, 32). Both intermolecular A␤-Cu 2ϩ and A␤-Zn 2ϩ coordination have been reported via histidine bridges (28, 30 -33). Fe 3ϩ has also been shown to interact with histidines (37). Dissociation constants for the binding affinity of

These results demonstrate that consuming a commercially available ED before exercise can improve endurance performance and that this improvement might be in part the result of increased effort without a concomitant increase in perceived exertion.

Numerous investigations of photon upconversion in lanthanide-doped upconversion nanoparticles (UCNPs) have led to its application in the fields of bioimaging, biodetection, cancer therapy, displays, and energy conversion. Herein, we demonstrate a new approach toward lanthanidedoped UCNPs and a graphene hybrid planar and rippled structure photodetector. The multi-energy sublevels from the 4f n electronic configuration of lanthanides results in longer excited state lifetime for photogenerated charge carriers. This opens up a new regime for ultra-high-sensitivity and broadband photodetection. Under 808 nm infrared light illumination, the planar hybrid photodetector shows a photoresponsivity of 190 AW −1 , which is higher than the currently reported responsivities of the same class of devices. Also, the rippled graphene and UCNPs hybrid photodetector on a poly(dimethylsiloxane) substrate exhibits an excellent stretchability, wearability, and durability with high photoresponsivity. This design makes a significant contribution to the ongoing research in the field of wearable and stretchable optoelectronic devices.

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Abstract:The purpose of this study was to investigate the effect of green tea extract (GTE) supplementation combined with endurance training on endurance capacity and performance in sedentary men. Forty untrained men (age: 20 ± 1 years) participated in this study. Subjects were assigned to 1 of 4 treatments: (i) placebo-control (CTRL), (ii) GTE, (iii) endurance training (Ex), and (iv) endurance training with GTE (ExGTE). During the 4-week intervention, exercise training was prescribed as 75% oxygen uptake reserve for three 20-min sessions per week, and either GTE (250 mg/day) or placebo was provided. Endurance capacity, malondialdehyde (MDA), total antioxidant status (TAS), and creatine kinase (CK) were examined. Ex and ExGTE but not GTE improved exhaustive-run time (Ex: +8.2%, p = 0.031; ExGTE: +14.3%, p < 0.001); in addition, Ex and ExGTE significantly increased maximal oxygen uptake by ϳ14% (p = 0.041) and ϳ17% (p = 0.017) above the values of the CTRL group, respectively. Both Ex and ExGTE significantly decreased the increase of CK by ϳ11%-32% below that of CTRL following an exhaustive run (Ex: p = 0.007; ExGTE: p = 0.001). Moreover, TAS levels increased by ϳ11% in ExGTE after training (p = 0.040), and GTE, Ex, and ExGTE markedly attenuated exercise-induced MDA production (p = 0.01, p = 0.005, p = 0.011, respectively). In conclusion, this investigation demonstrated that daily ingestion of GTE during endurance training does not impair improvements in endurance capacity. Moreover, endurance training combined with GTE not only increases antioxidant capacity without attenuating endurance training adaptations, but also further attenuates acute exercise-induced CK release.Key words: V O 2max , malondialdehyde (MDA), creatine kinase (CK), oxidative stress, catechins.Résumé : Cette étude se propose d'examiner l'effet de la supplémentation en extrait de thé vert (« GTE ») combinée à l'entraînement en endurance sur la capacité d'endurance et la performance chez des hommes sédentaires. Quarante hommes non entraînés (âge de 20 ± 1 ans) participent à cette étude. Les sujets sont assignés à l'un des quatre traitements : (i) placebocontrôle (« CTRL »), (ii) GTE, (iii) entraînement en endurance (Ex) et (iv) entraînement en endurance plus GTE (ExGTE). Durant les quatre semaines de l'intervention, l'entraînement physique consiste en trois séances de 20 min à une intensité sollicitant 75 % du consommation d'oxygène de réserve dans la condition de GTE (250 mg/jour) ou de placebo. On évalue la capacité d'endurance, le taux de malonaldéhyde (« MDA »), le statut antioxydant total (« TAS ») et la créatine kinase (« CK »). Ex et ExGTE, mais pas GTE suscitent une amélioration du temps de course jusqu'à épuisement (Ex: +8,2 %, p = 0,031; ExGTE: +14,3 %, p < 0,001); de plus, Ex et ExGTE suscitent une augmentation significative du consommation maximale d'oxygène de ϳ14 % (p = 0,041) et de ϳ17 % (p = 0,017) respectivement par rapport au groupe CTRL. EX et ExGTE suscitent une baisse significative de l'augmentation de CK de ϳ11-32 % par rap...

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Aims:  To isolate a bacterium that produces high yield of melanin and to examine the effect of this bacterial pigment on the efficacy of a bioinsecticide. Methods and Results:  A novel melanin‐producing bacterium, designated as strain WS, was isolated from the East Lake, Wuhan, China. Taxonomic studies of this strain indicate that it belongs to Aeromonas media. Physicochemical analysis of the pigment produced by strain WS (melanin WS) suggests that it is the authentic 3,4‐dihydroxyphenylalanine (DOPA)‐melanin. This melanin and that produced by Pseudomonas maltophilia P28 (melanin P28) share many biophysical properties, but the yield of the melanin WS is significantly higher than that of the melanin P28. In addition, the melanin WS appears to be more effective in the protection of a bioinsecticide against ultraviolet (UV) or solar radiation. At the concentration of 10 ppm, the melanin P28 exhibited no photoprotective effect on the bioinsecticide against UV radiation; in contrast, 5 ppm of melanin WS displayed an obvious protective effect. Similarly, the melanin WS displayed more protective effect on the bioinsecticide against solar radiation than the melanin P28 did over a 4‐day period, with the effect being more dramatic for the last 2 days. Conclusions:  We have isolated a novel bacterial strain of A. media that produces high levels of melanin. The melanin produced by this strain offers effective photoprotection of a commercial bioinsecticide BTI against UV and solar radiation. Significance and Impact of the Study:  Our study suggests that the melanin produced by our newly isolated A. media strain has the potential to be used as a general photoprotective agent for bioinsecticides.