"Spatio-temporal symmetries of electronic chirality flips in oriented RbCs induced by two coincident laser pulses with circular ++,+-,-+,-- polarizations".

Recently it has been shown that two coincident well designed laser pulses with two different combinations of circular polarizations ( ++ or -+ ) can create chiral electronic densities in an oriented heteronuclear diatomic molecule. Subsequently, the chirality flips from the electronic Ra to Sa to Ra to Sa etc. enantiomers, with periods in the femtosecond (fs) and attosecond (as) time domains. The results were obtained by means of quantum dynamics simulations for oriented NaK. Here we investigate the electronic chirality flips in oriented RbCs induced by all possible ( ++ , -+ , +- , -- ) combinations of circular polarizations of two coincident well-designed laser pulses. Accordingly, the ++ and -- as well as the +- and -+ combinations generate opposite electronic enantiomers, e. g. Ra versus Sa, followed by opposite periodic chirality flips, e.g. form Ra to Sa to Ra to Sa  etc. versus form Sa to Ra to Sa to Ra  etc, with periods in the fs and as time domains, respectively. The laser induced spatio-temporal symmetries are derived from first principles and illustrated by quantum dynamics simulations.

Reflectivity and Angular Anisotropy of Liquid Crystal Microcapsules with Different Particle Sizes by Complex Coalescence.

Cholesteric liquid crystal microcapsules (CLCMs) are used to improve the stability of liquid crystals while ensuring their stimulus response performance and versatility, with representative applications such as sensing, anticounterfeiting, and smart fabrics. However, the reflectivity and angular anisotropy decrease because of the anchoring effect of the polymer shell matrix, and the influence of particle size on this has not been thoroughly studied. In this study, the effect of synthesis technology on microcapsule particle size was investigated using a complex coalescence method, and the effect of particle size on the reflectivity and angular anisotropy of CLCMs was investigated in detail. A particle size of approximately 66 µm with polyvinyl alcohol (PVA, 1:1) exhibited a relative reflectivity of 16.6% and a bandwidth of 20 nm, as well as a narrow particle size distribution of 22 µm. The thermosetting of microcapsules coated with PVA was adjusted and systematically investigated by controlling the mass ratio. The optimized mass ratio of microcapsules (66 µm) to PVA was 2:1, increasing the relative reflectivity from 16.6% (1:1) to 32.0% (2:1) because of both the higher CLCM content and the matching between the birefringence of the gelatin-arabic shell system and PVA. Furthermore, color based on Bragg reflections was observed in the CLCM-coated ortho-axis and blue-shifted off-axis, and this change was correlated with the CLCM particle size. Such materials are promising for anticounterfeiting and color-based applications with bright colors and angular anisotropy in reflection.

Unveiling the Stacking Fault-Driven Phase Transition Delaying Cryogenic Fracture in Fe-Co-Cr-Ni-Mo-C-Based Medium-Entropy Alloy.

In this work, the tensile deformation mechanisms of the Fe55Co17.5Cr12.5Ni10Mo5-xCx-based medium-entropy alloy at room temperature (R.T.), 77 K, and 4.2 K are studied. The formation of micro-defects and martensitic transformation to delay the cryogenic fracture are observed. The results show that FeCoCrNiMo5-xCx-based alloys exhibit outstanding mechanical properties under cryogenic conditions. Under an R.T. condition, the primary contributing mechanism of strain hardening is twinning-induced plasticity (TWIP), whereas at 77 K and 4.2 K, the activation of martensitic transformation-induced plasticity (TRIP) becomes the main strengthening mechanism during cryogenic tensile deformation. Additionally, the carbide precipitation along with increased dislocation density can significantly improve yield and tensile strength. Furthermore, the marked reduction in stacking fault energy (SFE) at cryogenic temperatures can promote mechanisms such as twinning and martensitic transformations, which are pivotal for enhancing ductility under extreme conditions. The Mo4C1 alloy obtains the optimal strength-ductility combination at cryogenic-to-room temperatures. The tensile strength and elongation of the Mo4C1 alloy are 776 MPa and 50.5% at R.T., 1418 MPa and 71.2% in liquid nitrogen 77 K, 1670 MPa and 80.0% in liquid helium 4.2 K, respectively.

Time-dependent Extension of Grimme's Continuous Chirality Measure for Electronic Chirality Flips in Femto- and Attosecond Time Domains.

Grimme's Continuous Chirality Measure (CCM ) was developed for comparisons of the chirality of the electronic wave functions of molecules, typically in their ground states. For example, CCM=14.5, 1.2,  and 0.0 for alanine, hydrogen-peroxide, and for achiral molecules, respectively. Well-designed laser pulses can excite achiral molecules from the electronic ground state to time-dependent chiral superposition states, with chirality flips in the femto- or even attosecond (fs or as) time domains. Here we provide a time-dependent extension CCM(t) of Grimme's CCM for trailing the electronic chirality flips. As examples, we consider two laser driven electronic wavefunctions which represent flips between opposite electronic enantiomers of oriented NaK within 4.76 fs and 433 as. The corresponding  CCM(t) vary respectively from 14.5 or from 13.3 to 0.0, and back.

Crystalline-dependent surface reconstruction at low applied potential region for enhanced oxygen evolution reaction.

Alkaline water electrolysis is apreferred technology for large-scale green hydrogen production. For most active transition metal-based catalysts during anodic oxygen evolution reaction (OER), the atomic structure of the anodic catalysts' surface often undergoes reconstruction to optimize the reaction path and enhance their catalytic activity. The design and maintenance of highly active sites during this reconstruction process remain critical and challenging for most OER catalysts. In this study, we explored the effects of crystal structures in pre-catalysts on surface reconstruction at low applied potential. Through experimental observation and theoretical calculation, we found out that catalysts with specific crystal structures exhibit superior surface remodeling ability, which enables them to better adapt to the conditions of the oxygen evolution reaction and achieve efficient catalysis. The discharge process enables the formation of abundant phosphorus vacancies on the surface, which in turn affects the efficiency of the entire oxygen evolution reaction. The optimized crystal structure of the catalyst results in an increase as high as 58.5 mA/cm2 for Ni5P4, which is twice as high as that observed for Ni2P. These results provide essential theoretical foundations and technical guidance for designing more efficient catalysts for oxygen evolution reactions.

Restriction on molecular fluxionality by substitution: A case study for the 1,10-dicyanobullvalene.

We show herein that 1,10-dicyano substitution restricts the paragon fluxionality of bullvalene to just 14 isomers which isomerize along a single cycle. The restricted fluxionality of 1,10-dicyanobullvalene (DCB) is investigated by means of: (i) Bonding analyses of the isomer structures using the adaptive natural density partitioning (AdNDP). (ii) Quantum dynamical simulations of the isomerizations along the cyclic intrinsic reaction coordinate of the potential energy surface (PES). The PES possesses 14 equivalent potential wells supporting 14 isomers which are separated by 14 equivalent potential barriers supporting 14 transition states. Accordingly, at low temperatures, DCB appears as a hindered molecular rotor, without any delocalization of the wavefunction in the 14 potential wells, without any nuclear spin isomers, and with completely negligible tunneling. These results are compared and found to differ from those for molecular boron rotors. (iii) Born-Oppenheimer molecular dynamics (BOMD) simulations of thermally activated isomerizations. (iv) Calculations of the rate constants in the frame of transition state theory (TST) with reasonable agreement achieved with the BOMD results. (v) Simulations of the equilibration dynamics using rate equations for the isomerizations with TST rate coefficients. Accordingly, in the long-time limit, isomerizations of the 14 isomers, each with Cs symmetry, approach the "14 Cs → C7v" thermally averaged structure. This is a superposition of the 14 equally populated isomer structures with an overall C7v symmetry. By extrapolation, the results for DCB yield working hypotheses for so far un-explored properties e.g. for the equilibration dynamics of C10H10.

Photochemical and biological dual-effects enhance the inhibition of photosensitizers for tumour growth.

Photosensitizers typically rely on a singular photochemical reaction to generate reactive oxygen species, which can then inhibit or eradicate lesions. However, photosensitizers often exhibit limited therapeutic efficiency due to their reliance on a single photochemical effect. Herein, we propose a new strategy that integrates the photochemical effect (type-I photochemical effect) with a biological effect (proton sponge effect). To test our strategy, we designed a series of photosensitizers (ZZ-sers) based on the naphthalimide molecule. ZZ-sers incorporate both a p-toluenesulfonyl moiety and weakly basic groups to activate the proton sponge effect while simultaneously strengthening the type-I photochemical effect, resulting in enhanced apoptosis and programmed cell death. Experiments confirmed near-complete eradication of the tumour burden after 14 days (Wlight/Wcontrol ≈ 0.18, W represents the tumour weight). These findings support the notion that the coupling of a type-I photochemical effect with a proton sponge effect can enhance the tumour inhibition by ZZ-sers, even if the basic molecular backbones of the photosensitizers exhibit nearly zero or minimal tumour inhibition ability. We anticipate that this strategy can be generalized to develop additional new photosensitizers with improved therapeutic efficacy while overcoming limitations associated with systems relying solely on single photochemical effects.

Activation of Nrf2/HO-1 signaling pathway exacerbates cholestatic liver injury.

Nuclear factor erythroid 2-related factor-2 (Nrf2) antioxidant signaling is involved in liver protection, but this generalization overlooks conflicting studies indicating that Nrf2 effects are not necessarily hepatoprotective. The role of Nrf2/heme oxygenase-1 (HO-1) in cholestatic liver injury (CLI) remains poorly defined. Here, we report that Nrf2/HO-1 activation exacerbates liver injury rather than exerting a protective effect in CLI. Inhibiting HO-1 or ameliorating bilirubin transport alleviates liver injury in CLI models. Nrf2 knockout confers hepatoprotection in CLI mice, whereas in non-CLI mice, Nrf2 knockout aggravates liver damage. In the CLI setting, oxidative stress activates Nrf2/HO-1, leads to bilirubin accumulation, and impairs mitochondrial function. High levels of bilirubin reciprocally upregulate the activation of Nrf2 and HO-1, while antioxidant and mitochondrial-targeted SOD2 overexpression attenuate bilirubin toxicity. The expression of Nrf2 and HO-1 is elevated in serum of patients with CLI. These results reveal an unrecognized function of Nrf2 signaling in exacerbating liver injury in cholestatic disease.

Efficient Catalytic Degradation of Methyl Orange by Various ZnO-Doped Lignin-Based Carbons.

Herein, a series of ZnO-doped lignin-based carbons (LC/ZnO) were successfully prepared from different types of lignin and used for methyl orange (MO) photocatalytic degradation. The apparent morphology, internal structure, and photoelectric properties of prepared LC/ZnO composites and their effects on subsequent MO photocatalytic degradation were investigated by various characterization techniques. The results showed that the LC/ZnO composites that were prepared in this work mainly consisted of highly dispersed ZnO nanoparticles and lignin-based carbon nano-sheets, which were beneficial for subsequent photogenerated electrons and holes formation, dispersion, and migration. The MO could be significantly degraded with various ZnO-doped lignin-based carbons, especially over the LCSL/ZnO, and the maximum degradation rate was 96.9% within 30 min under the simulated 300w sunlight exposure. The experiments of free radical elimination showed that the photocatalytic degradation of MO over LC/ZnO were a result of the co-action of multiple free radicals, and h+ might play the predominant roles in MO degradation. In addition, the pH of the solution had little effect on MO degradation, and the MO could be effectively degraded even in an alkaline solution of pH = 12.0. The cycling experiments showed that the prepared LC/ZnO had a good stability for MO photodegradation, especially for LCSL/ZnO, even after 5 times recycling, and the degradation rate of MO only dropped from 97.0% to 93.0%. The research not only provided a fundamental theory for the efficient photocatalytic degradation of MO by LC/ZnO composites, but also offered a new insight into lignin valorization.

Inhibition of mitochondrial ROS-mediated necroptosis by Dendrobium nobile Lindl. alkaloids in carbon tetrachloride induced acute liver injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium nobile Lindl. (DNL) is a well-known traditional Chinese medicine that has been recorded in the Chinese Pharmacopoeia (2020 edition). The previous data showed that Dendrobium nobile Lindl. alkaloids (DNLA) protect against CCl4-induced liver damage via oxidative stress reduction and mitochondrial function improvement, yet the exact regulatory signaling pathways remain undefined. AIM OF THE STUDY: The aim of the present study was to investigate the role of necroptosis in the mode of CCl4-induced liver injury and determine whether DNLA protects against CCl4-induced acute liver injury (ALI) by inhibiting mitochondrial ROS (mtROS)-mediated necroptosis. MATERIALS AND METHODS: DNLA was extracted from DNL, and the content was determined using liquid chromatograph mass spectrometer (LC-MS). In vivo experiments were conducted in C57BL/6J mice. Animals were administrated with DNLA (20 mg/kg/day, ig) for 7 days, and then challenged with CCl4 (20 µL/kg, ip). CCl4-induced liver injury in mice was evaluated through the assessment of biochemical indicators in mouse serum and histopathological examination of hepatic tissue using hematoxylin and eosin (H&E) staining. The protein and gene expressions were determined with western blotting and quantitative real-time PCR (RT-qPCR). Reactive oxygen species (ROS) production was detected using the fluorescent probe DCFH-DA, and mitochondrial membrane potential was evaluated using a fluorescent probe JC-1. The mtROS level was assessed using a fluorescence probe MitoSOX. RESULTS: DNLA lessened CCl4-induced liver injury, evident by reduced AST and ALT levels and improved liver pathology. DNLA suppressed necroptosis by decreasing RIPK1, RIPK3, and MLKL phosphorylation, concurrently enhancing mitochondrial function. It also broke the positive feedback loop between mtROS and RIPK1/RIPK3/MLKL activation. Similar findings were observed with resveratrol and mitochondrial SOD2 overexpression, both mitigating mtROS and necroptosis. Further mechanistic studies found that DNLA inhibited the oxidation of RIPK1 and reduced its phosphorylation level, whereby lowering the phosphorylation of RIPK3 and MLKL, blocking necroptosis, and alleviating liver injury. CONCLUSIONS: This study demonstrates that DNLA inhibits the necroptosis signaling pathway by reducing mtROS mediated oxidation of RIPK1, thereby reducing the phosphorylation of RIPK1, RIPK3, and MLKL, and protecting against liver injury.

Circularly Polarized Luminescence of Cholesteric Liquid Crystal Polymer Networks with a Europium(III) Complex as an Emitter.

A coordination complex, Eu(C12C12dbm)3(phen), with strong emission and a high quantum yield (QY ∼ 51.9%) was synthesized. The EuIII complex, as a fluorescent emitter, was embedded in cholesteric liquid crystal polymer networks (CLCNs). A series of free-standing EuIII-CLCN films were obtained, generating a typical sharp emission band corresponding to the EuIII complex. Tunable handedness of circularly polarized luminescence (CPL) with high |glum| values (up to 0.63) was observed. A series of CPL-active CLCN-coated PET films were also prepared (|glum| values up to 0.63), which can be used for large-area preparations. Moreover, by stacking an emitter-embedded PMMA layer and a CLCN layer, a composite system was built, and a large |glum| value (∼1.42) was achieved. Fluorescence patterns were prepared, and distinct images of CLCN films were recognized under both daylight and UV light. This work not only demonstrated that coordination compounds could be incorporated with CLCN films to prepare CPL-active materials with high |glum| values but also provided a new perspective for emissive CLCN materials used for anticounterfeiting and encryption.

Theoretical insights into excited state behaviors of D3HF derivatives via altering atomic electronegativity of chalcogen.

Inspired by the distinguished photochemical characteristics of new organic molecule containing the chalcogenide substitution that could be potentially applied across various disciplines, in this work, the effects of atomic electronegativity of chalcogen (O, S and Se) on hydrogen bond interactions and proton transfer (PT) reaction. We present the characteristic 2,8-diphenyl-3,7-dihydroxy-4H,6H-pyrano[3,2-g]-chromene-4,6-dione (D3HF), which is based on 3-hydroxyflavone (3HF) and contains intramolecular double hydrogen bonds that is the main objective of this study to explore in detail the influence of the change of atomic electronegativity on the dual hydrogen bond interaction and the excited state proton transfer (ESPT) behavior by photoexcitation. By comparing the structural changes and infrared (IR) vibrational spectra of the D3HF derivatives (D3HF-O, D3HF-S and D3HF-Se) fluorophores in S0 and S1 states, combined with the preliminary detection of hydrogen bond interaction by core-valence bifurcation (CVB) index, we can conclude that the hydrogen bond is strengthened in S1 state, which is favorable for the occurrence of ESPT reactions. The charge recombination behavior of hydrogen bond induced by photoexcitation also further illustrates this point. Via constructing potential energy surfaces (PESs) based on restrictive optimization, we finally clarify the excited state single PT mechanism for D3HF derivatives. Specially, we confirm change of atomic electronegativity has a regulatory effect on the ESIPT behavior of D3HF and its derivatives, that is, the lower the atomic electronegativity is more conducive to the ESIPT reaction.

Polymer Network Film with Double Reflection Bands Prepared Using a Thermochromic Cholesteric Liquid Crystal Mixture.

Cholesteric liquid crystal polymer network (CLCN) films with a single reflection band have found applications for decoration and anticounterfeiting. The CLCN films with double reflection bands were more suitable for these applications. Herein, they were prepared by using thermochromic cholesteric liquid crystals (CLCs) through a two-step photopolymerization approach. At the first step, due to oxygen inhibition, the CLC monomers near the substrate surface were polymerized at a certain temperature. At the second step, those near the air were polymerized at another temperature. The wavelengths of these two reflection bands of the CLCN film were dominated by the two polymerization temperatures. Based on this approach, patterns with composite colors were prepared, which were suitably applied for decoration. Moreover, a double-layered CLCN film with a broad reflection band was prepared that could potentially be applied for displays.

Distinguishing the responsive mechanisms of fluorescent probes to hydrogen peroxide, proteins, and DNA/RNA.

The responsive mechanisms of cationic quinolinium-vinyl-N,N-dimethylaniline boronate (QVD-B) derivative probes to hydrogen peroxide (H2O2), proteins and DNA/RNA are theoretically investigated in this study. The potential energy curves of QVD-B scanned on a dihedral angle (N+-C-CC) in the first singlet (S1) state exhibit large torsional energy barriers. Additionally, the energy of the lowest unoccupied molecular orbital (LUMO) of an acceptor moiety (-3.14 eV) is lower than that of a donor moiety (-1.13 eV) in QVD-B. This demonstrates that photoinduced electron transfer (PET) quenches the fluorescence of QVD-B, as opposed to the previous report of intramolecular single-bond rotation. After reacting with H2O2, the reaction product of quinoline-vinyl-N,N-dimethylaniline (QVD) turns off the PET pathway and turns on the fluorescence at 550 nm, which is consistent with the experimental results (580 nm). Among the possible configurations of QVD-B that forms with proteins and DNA, the calculated fluorescence values of corresponding twisted QVD-B-P (638 nm) and QVD-B-D (686 nm) are consistent with the experimental results (632 and 688 nm). The frontier molecular orbital and electron-hole analysis show that the charge transfer distance follows the order of QVD (1.88 Å) < QVD-B-P (4.49 Å) < QVD-B-D (6.39 Å), which induces the fluorescence red-shifts of QVD-B-P and QVD-B-D compared to that of QVD. The multi-detection mechanism of the fluorescent probe QVD-B is attributed to PET progress and different degrees of local charge transfer after photoexcitation.

From chiral laser pulses to femto- and attosecond electronic chirality flips in achiral molecules.

Chirality is an important topic in biology, chemistry and physics. Here we show that ultrashort circularly polarized laser pulses, which are chiral, can be fired on achiral oriented molecules to induce chirality in their electronic densities, with chirality flips within femtoseconds or even attoseconds. Our results, obtained by quantum dynamics simulations, use the fact that laser pulses can break electronic symmetry while conserving nuclear symmetry. Here two laser pulses generate a superposition of three electronic eigenstates. This breaks all symmetry elements of the electronic density, making it chiral except at the periodic rare events of the chirality flips. As possible applications, we propose the combination of the electronic chirality flips with Chiral Induced Spin Selectivity.

Electrogenic sulfur oxidation mediated by cable bacteria and its ecological effects.

At the sediment-water interfaces, filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors. These multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple elements. Cable bacteria were first reported in 2012. In the past years, cable bacteria have been found to be widely distributed across the globe. Their potential in shaping the surface water environments has been extensively studied but is not fully elucidated. In this review, the biogeochemical characteristics, conduction mechanisms, and geographical distribution of cable bacteria, as well as their ecological effects, are systematically reviewed and discussed. Novel insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.

Cations induced in situ electrochemical amorphization for enhanced oxygen evolution reaction.

Surface reconstruction is widely existed on the surface of transition metal-based catalysts under operando oxygen evolution reaction (OER) condition. The design and optimize the reconstruction process are essential to achieve high electrochemical active surface and thus facilitate the reaction kinetics, whereas still challenge. Herein, we exploit electrolyte engineering to regulate reconstruction on the surface of Fe2O3 catalysts under operando OER conditions. The intentional added cations in electrolyte can participate the reconstruction process and realize a desirable crystalline to amorphous structure conversion, contributing abundant well-defined active sites. Spectroscopic measurements and density functional theory calculation provide insight into the underlying role of amorphous structure for electron transfer, mass transport, and intermediate adsorption. With the assistant of Co2+ cations, the enhanced current density as large as 17.9 % can be achieved at 2.32 V (vs RHE). The present results indicate the potential of electrolyte engineering for regulating the reconstruction process and provide a generalized in-situ strategy for advanced catalysts design.

SIRT3-Mediated Deacetylation of SDHA Rescues Mitochondrial Bioenergetics Contributing to Neuroprotection in Rotenone-Induced PD Models.

Mitochondrial dysfunction is critically involved in the degeneration of dopamine (DA) neurons in the substantia nigra, a common pathological feature of Parkinson's disease (PD). Previous studies have demonstrated that the NAD+-dependent acetylase Sirtuin 3 (SIRT3) participates in maintaining mitochondrial function and is downregulated in aging-related neurodegenerative disorders. The exact mechanism of action of SIRT3 on mitochondrial bioenergetics in PD pathogenesis, however, has not been fully described. In this study, we investigated the regulatory role of SIRT3-mediated deacetylation of mitochondrial complex II (succinate dehydrogenase) subunit A (SDHA) and its effect on neuronal cell survival in rotenone (ROT)-induced rat and differentiated MN9D cell models. The results revealed that SIRT3 activity was suppressed in both in vivo and in vitro PD models. Accompanying this downregulation of SIRT3 was the hyperacetylation of SDHA, impaired activity of mitochondrial complex II, and decreased ATP production. It was found that the inhibition of SIRT3 activity was attributed to a reduction in the NAD+/NADH ratio caused by ROT-induced inhibition of mitochondrial complex I. Activation of SIRT3 by icariin and honokiol inhibited SDHA hyperacetylation and increased complex II activity, leading to increased ATP production and protection against ROT-induced neuronal damage. Furthermore, overexpression of SDHA also exerted potent protective benefits in cells treated with ROT. In addition, treatment of MN9D cells with the NAD+ precursor nicotinamide mononucleotide increased SIRT3 activity and complex II activity and promoted the survival of cells exposed to ROT. These findings unravel a regulatory SIRT3-SDHA axis, which may be closely related to PD pathology. Bioenergetic rescue through SIRT3 activation-dependent improvement of mitochondrial complex II activity may provide an effective strategy for protection from neurodegeneration.

Effects of postponing nitrogen topdressing on starch structural properties of superior and inferior grains in hybrid indica rice cultivars with different taste values.

Introduction: Nitrogen (N) fertilizer management, especially postponing N topdressing can affect rice eating quality by regulating starch quality of superior and inferior grains, but the details are unclear. This study aimed to evaluate the effects of N topdressing on starch structure and properties of superior and inferior grains in hybrid indica rice with different tastes and to clarify the relationship between starch structure, properties, and taste quality. Methods: Two hybrid indica rice varieties, namely the low-taste Fyou 498 and high-taste Shuangyou 573, were used as experimental materials. Based on 150 kg·N hm-2, three N fertilizer treatments were established: zero N (N0), local farmer practice (basal fertilizer: tillering fertilizer: panicle fertilizer=7:3:0) (N1), postponing N topdressing (basal fertilizer: tillering fertilizer: panicle fertilizer=3:1:6) (N2). Results: The starch granules of superior grains were more complete, and the decrease in small granules content and the stability of starch crystals were a certain extent less than those of inferior grains. Compared with N1, under N2, low-taste and high-taste varieties large starch granules content were significantly reduced by 6.89%, 0.74% in superior grains and 4.26%, 2.71% in inferior grains, the (B2 + B3) chains was significantly reduced by 1.61%, 0.98% in superior grains, and 1.18%, 0.97% in inferior grains, both reduced the relative crystallinity and 1045/1022 cm-1, thereby decreasing the stability of the starch crystalline region and the orderliness of starch granules. N2 treatment reduced the ΔHgel of two varieties. These changes ultimately contributed to the enhancement of the taste values in superior and inferior grains in both varieties, especially the inferior grains. Correlation analysis showed that the average starch volume diameter (D[4,3]) and relative crystallinity were significantly positively correlated with the taste value of superior and inferior sgrains, suggesting their potential use as an evaluation index for the simultaneous enhancement of the taste value of rice with superior and inferior grains. Discussion: Based on 150 kg·N hm-2, postponing N topdressing (basal fertilizer: tillering fertilizer: panicle fertilizer=3:1:6) promotes the enhancement of the overall taste value and provides theoretical information for the production of rice with high quality.

Polymer-Stabilized Cholesteric Liquid Crystal Films with Double Reflection Bands Prepared Based on the Competition between Photopolymerization and Photoisomerization.

Composite colors have been widely found in nature. Herein, polymer-stabilized cholesteric liquid crystal (PSCLC) films with composite structural colors were prepared through a one-step photopolymerization approach. The CLC mixtures were prepared using a mixture of acrylates and a mixture of two chiral dopants. One of the chiral dopants is polymerizable, and the other one is photoisomerizable. After photopolymerization, the PSCLC films with double Bragg reflection bands were obtained on the surface of a substrate. The competition between the photopolymerization of the acrylates and the photoisomerization of the chiral dopant was proposed to drive the formation of the double reflection bands. Without oxygen inhibition, the polymerization of the acrylates near the substrate surface was carried out. However, due to oxygen inhibition, the polymerization of the acrylates near the air was retarded. Then, the photoisomerization of the chiral dopant was carried out prior to the polymerization of the acrylates. The wavelengths of the double reflection bands were tunable by changing the concentrations of the acrylates and chiral dopants and the polymerization temperature. Colorful patterns with composite structural colors were prepared, which were suitable for decoration and anti-counterfeiting.