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The α-L-rhamnosidase BtRha from Bacteroides thetaiotao VPI-5482 is a specific enzyme that selectively hydrolyzes the α-1,2 glycosidic bond between rhamnose and rhamnose, allowing the bioconversion of epimedin C to icariin. In this study, BtRha was molecularly modified using B-factor-saturation mutagenesis strategy and the introduction of disulfide bonds, resulting in a mutant with significantly improved catalytic efficiency, S592C, and two thermally stable mutants, E39W and E39W-S592C. The results showed that the half-lives of E39W and E39W-S592C at 55 °C were 10.4 and 9.4-fold higher, respectively, than that of the original enzyme, The mutant S592C showed a 63.3% reduction in K

The lack of highly efficient blue‐emitting perovskite nanocrystals limits their development for optoelectronic applications. In article number 2001698, Bartomeu Monserrat, Shuyu Zhang, and co‐workers develop blue‐emitting neodymium‐doped CsPbBr3 nanocrystals with high photoluminescence quantum yield (PLQY) and narrow spectral width. First principles calculations reveal the microscopic mechanisms for the blueshift of photoluminescence and the enhancement of PLQY upon doping. [Image: see text]

Ginkgo tea is a kind of health food produced from Ginkgo biloba leaves. The market of Ginkgo tea encountered many difficulties because of its bad palatability and vague function statement. In this study, two kinds of glycosidase were used to improve the flavor of Ginkgo tea, and three kinds of bioactivities were selected to investigate the health care function of the tea infusion. The aroma components extracted by headspace absorb (HSA) method during the making of Ginkgo tea were analyzed by GC-MS. The flavonoids and ginkgolides released into the tea infusion were studied by HPLC. A combination of &beta, glucosidase (&beta, G) and &alpha, rhamnosidase (&alpha, R) was applied during the making of the tea. The contents of characteristic aroma components and the release of total flavonoids and ginkgolides were increased significantly by adding &beta, G and &alpha, R. The composition of flavone glycosides was changed greatly. The free radical scavenging, inhibition of inflammatory cell activation, and tumor cytotoxicity activities of the tea were demonstrably improved. According to the release of active components, Ginkgo tea can be brewed repeatedly for at least three times. The enzymes used here show potential application prospects in the making of Ginkgo tea or tea drink to get higher contents of flavonoids, ginkgolides, and aroma components.

Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals exhibit tunable bandgaps over the entire visible spectrum and high photoluminescence quantum yields in the green and red regions. However, the lack of highly efficient blue‐emitting perovskite nanocrystals limits their development for optoelectronic applications. Herein, neodymium (III) (Nd3+) doped CsPbBr3 nanocrystals are prepared through the ligand‐assisted reprecipitation method at room temperature with tunable photoemission from green to deep blue. A blue‐emitting nanocrystal with a central wavelength at 459 nm, an exceptionally high photoluminescence quantum yield of 90%, and a spectral width of 19 nm is achieved. First principles calculations reveal that the increase in photoluminescence quantum yield upon doping is driven by an enhancement of the exciton binding energy due to increased electron and hole effective masses and an increase in oscillator strength due to shortening of the PbBr bond. Putting these results together, an all‐perovskite white light‐emitting diode is successfully fabricated, demonstrating that B‐site composition engineering is a reliable strategy to further exploit the perovskite family for wider optoelectronic applications.

Pressure and temperature are powerful tools applied to perovskites to achieve recrystallization. Lamination, based on recrystallization of perovskites, avoids the limitations and improves the compatibility of materials and solvents in perovskite device architectures. In this work, we demonstrate tightly compacted perovskite laminates on flexible substrates via hot-pressing and investigate the effect of hot-pressing conditions on the lamination qualities and optical properties of perovskite laminates. The optimized laminates achieved at a temperature of 90 °C and a pressure of 10 MPa could sustain a horizontal pulling pressure of 636 kPa and a vertical pulling pressure of 71 kPa. Perovskite laminates exhibit increased crystallinity and a crystallization orientation preference to the (100) direction. The optical properties of laminated perovskites are almost identical to those of pristine perovskites, and the photoluminescence quantum yield (PLQY) survives the negative impact of thermal degradation. This work demonstrates a promising approach to physically laminating perovskite films, which may accelerate the development of roll-to-roll printed perovskite devices and perovskite tandem architectures in the future.

Visible light communication (VLC) is a promising candidate for high-speed wireless communication with numerous unlicensed spectrum. To achieve high-speed data communication, it requires intense light signals concentrated on a tiny fast photodiode. The common way of using focusing optics reduces the field of view (FoV) of the photodiode due to the conservation of etendue. Luminescent solar concentrators (LSC) provide a solution to enhance the signals without affecting the FoV. In this paper we demonstrate nanopatterned LSCs fabricated on flexible plastics that achieve a doubling of optical gain compared to its traditional rectangular counterparts. These LSCs can free VLC detectors from complex active pointing and tracking systems, making them compatible with smart mobile terminals in a simple fashion.

Room temperature recrystallization is an intriguing method of fabricating CsPbX3 perovskite quantum dots since it does not involve high temperature or inert atmosphere, offering a promising route to the mass production of CsPbX3 quantum dots at low cost. However, their performance stability during work was seldom investigated and was far from the requirements for practical applications. Here, we demonstrate a facile and low-cost method to significantly improve the thermal, photo- and water stability of room-temperature synthesized perovskite quantum dots by effectively suppressing the unfavored grain growth and surface trap states. The fabricated quantum dots of green-emitting CsPbBr3 and red-emitting CsPbBr1.2I1.8 were applied for quantum dot-converted white LEDs, which are capable of achieving a wide color gamut of 135% NTSC and 101% Rec. 2020.