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This study systematically investigated the physiological and molecular responses of the wheat mutant 'XC-MU201' under high-temperature stress through comprehensive transcriptome analysis and physiological measurements. RNA sequencing of 21 samples across seven different treatment groups revealed, through Weighted Gene Co-expression Network Analysis (WGCNA), 13 modules among 9071 genes closely related to high-temperature treatments. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed significant enrichment of lignin biosynthesis-related modules under high-temperature conditions, especially at the H-10DAT, H-20DAT, and H-30DAT time points. Experimental results demonstrated a significant increase in lignin content in high-temperature-treated samples, confirmed by tissue staining methods, indicating wheat's adaptation to heat damage through lignin accumulation. The phenylalanine ammonia-lyase gene (TaPAL33) was significantly upregulated under high-temperature stress, peaking at H-30DAT, suggesting its critical role in cellular defense mechanisms. Overexpression of TaPAL33 in the wheat variety 'Xinchun 11' enhanced lignin synthesis but inhibited growth. Subcellular localization of GFP-labeled TaPAL33 in tobacco cells showed its distribution mainly in the cytoplasm and cell membrane. Transgenic wheat exhibited higher PAL enzyme activity, enhanced antioxidant defense, and reduced oxidative damage under high-temperature stress, outperforming wild-type wheat. These results highlight TaPAL33's key role in improving wheat heat tolerance and provide a genetic foundation for future research and applications. [ABSTRACT FROM AUTHOR]

Patients with myocardial ischemia and infarction are at increased risk of arrhythmias, which in turn, can exacerbate the overall risk of mortality. Despite the observed reduction in recurrent arrhythmias through antiarrhythmic drug therapy, the precise mechanisms underlying their effectiveness in treating ischemic heart disease remain unclear. Moreover, there is a lack of specialized drugs designed explicitly for the treatment of myocardial ischemic arrhythmia. This study employs an electrophysiological simulation approach to investigate the potential antiarrhythmic effects and underlying mechanisms of various pharmacological agents in the context of ischemia and myocardial infarction (MI). Based on physiological experimental data, computational models are developed to simulate the effects of a series of pharmacological agents (amiodarone, telmisartan, E-4031, chromanol 293B, and glibenclamide) on cellular electrophysiology and utilized to further evaluate their antiarrhythmic effectiveness during ischemia. On 2D and 3D tissues with multiple pathological conditions, the simulation results indicate that the antiarrhythmic effect of glibenclamide is primarily attributed to the suppression of efflux of potassium ion to facilitate the restitution of [K+]o, as opposed to recovery of IKATP during myocardial ischemia. This discovery implies that, during acute cardiac ischemia, pro-arrhythmogenic alterations in cardiac tissue's excitability and conduction properties are more significantly influenced by electrophysiological changes in the depolarization rate, as opposed to variations in the action potential duration (APD). These findings offer specific insights into potentially effective targets for investigating ischemic arrhythmias, providing significant guidance for clinical interventions in acute coronary syndrome. Author summary: In acute coronary syndrome, the progression of ischemic, injury, and infarction conditions heightens the risk of ischemic cardiac arrhythmias. Despite the existence of various antiarrhythmic drugs, there remains a scarcity of medications specifically tailored for ischemic cardiac arrhythmias. Moreover, comprehending the diverse drug responses in tissues with multiple ischemic conditions (ischemia 1a, 1b, and infarction) remains incomplete. Therefore, in this study, mathematical models depicting the electrophysiological remodeling induced by different drugs such as amiodarone, telmisartan, E-4031, chromanol 293B, and glibenclamide, are constructed and integrated into multi-scale computational models to assess their antiarrhythmic effects. Simulation results demonstrate the potential of glibenclamide in mitigating ischemic cardiac arrhythmias. It can be attributed to its ability not only to improve the depolarization phase's membrane potential by inhibiting extracellular potassium accumulation during the ischemic stage, leading to an increased dV/dtmax, but also to extend the action potential duration (APD) by suppressing IKATP. Finally, the application of glibenclamide results in heightened conduction velocity and prolonged APD at the tissue level. Consequently, these effects enlarge the wavelength of excitation waves, ultimately reducing the vulnerable window for reentrant wave and exhibiting an anti-ischemic arrhythmic effect. More importantly, it's shown that glibenclamide's inhibition of [K+]o yields a more significant impact on antiarrhythmic effects compared to its prolongation of APD. This is partly due to the more pronounced enhancement in the wavelength of excitation waves resulting from CV elevation compared with APD prolongation. Additionally, in tissues with coexisting multiple ischemic conditions, suppressing [K+]o reduces the spatial dispersion of CV, especially at the boundaries of different ischemic tissues like ischemia 1b and infarction, facilitating a more uniform excitation wave propagation. This study offers insights into the anti-arrhythmic mechanisms of established agents during acute coronary syndrome and identifies potential targets for novel anti-arrhythmic drug development. [ABSTRACT FROM AUTHOR]

Frequency upconversion photodetection by two‐dimensional (2D) materials with nonlinear optical response is an appealing technique for applications such as extending photodetection wavelength range, autocorrelation measurement, and high‐efficiency single photon detection. However, the frequency upconversion efficiency in 2D materials is limited due to the low efficiency of nonlinear optical processes and atomic light‐matter interaction length. Here, the efficient frequency upconversion photodetection is realized by van der Waals (vdW) integration of a few‐layer InSe with a silicon photonic crystal cavity (Si‐PPC). With the large second‐order nonlinearity of InSe and enhanced light‐matter interaction by Si‐PCC, continuous wave (CW) pumped second harmonic generation (SHG) is demonstrated with pump power down to 100 µW. Further, InSe and Si absorb the SHG photons and generate photocarriers which are separated and collected by the n‐InSe/p‐Si heterojunction. A frequency upconversion photoresponsivity of 16 µA W−1 with a CW laser at 1467 nm is obtained. More efficient SHG with pulsed laser improves the responsivity to 3.9 mA W−1 with quadratic power dependence, which is record‐high among the frequency upconversion photodetectors based on 2D materials. This work opens up opportunities for a high‐efficiency 2D material nonlinear photodetector integrated on photonic integrated circuits. [ABSTRACT FROM AUTHOR]

We demonstrate the post-induction of high-quality microcavities on a silicon photonic crystal (PC) waveguide by integrating a few-layer GaSe crystal, which promises efficient on-chip optical frequency conversions. The integration of GaSe shifts the dispersion bands of the PC waveguide mode into the bandgap, resulting in localized modes confined by the bare PC waveguides. Thanks to the small contrast of refractive index at the boundaries of the microcavity, it is reliable to obtain quality factors exceeding 10 4 . With the enhanced light-GaSe interaction by the microcavity modes and GaSe's high second-order nonlinearity, remarkable second-harmonic generation (SHG) and sum-frequency generation (SFG) are achieved with continuous-wave (CW) lasers.