Microcavity induced by a few-layer GaSe crystal on a silicon photonic crystal waveguide for efficient optical frequency conversion.

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 104. 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.

Deciphering High-Temperature-Induced Lignin Biosynthesis in Wheat through Comprehensive Transcriptome Analysis.

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.

A simulation study on the antiarrhythmic mechanisms of established agents in myocardial ischemia and infarction.

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.

Van der Waals Nonlinear Photodetector with Quadratic Photoresponse.

With unique electronic and optical attributes and dangling-bond-free surface, two-dimensional (2D) materials have broadened the functionalities of photodetectors. Here, we report a quadratically nonlinear photodetector (QNPD) composed of a van der Waals (vdW) stacked GaSe/InSe heterostructure. Compared with the reported 2D material-based photodetectors, the extra second-harmonic generation (SHG) process in GaSe/InSe leads to the quadratically nonlinear function between photocurrent and optical intensity, extending the photodetection wavelength from 900 to 1750 nm. The QNPD is highly sensitive to the variation of optical intensity with improved spatial resolution. With the light-light interaction in SHG converted into electrical signal directly, we also demonstrate the QNPD as an autocorrelator for measuring ultrafast pulse widths and an optoelectronic mixer of two modulated pulses for signal processings. The simultaneous involvement of light-light interaction and photoelectric conversion in the vdW stacked QNPD promises its potential to simplify the optoelectronic systems.

Systematic review and meta-analysis of minimally invasive versus open approach for pancreaticoduodenectomy.

BACKGROUNDS AND OBJECTIVE: The technique of minimally invasive pancreatic surgeries has evolved rapidly, including minimally invasive pancreaticoduodenectomy (MIPD). However, controversy on safety and feasibility remains when comparing the MIPD with the open pancreaticoduodenectomy (OPD); therefore, we aimed to compare MIPD and OPD with a systemic review and meta-analysis. METHODS: Multiple electronic databases were systematically searched to identify studies (up to February 2016) comparing MIPD with OPD. Intra-operative outcomes, oncologic data, postoperative complications and postoperative recovery were evaluated. RESULTS: Twenty-two retrospective studies including 6120 patients (1018 MIPDs and 5102 OPDs) were included. MIPD was associated with a reduction in estimated blood loss (WMD -312.00 ml, 95 % CI -436.30 to -187.70 ml, p < 0.001), transfusion rate (OR 0.41, 95 % CI 0.30-0.55, p < 0.001), wound infection (OR 0.37, 95 % CI 0.20-0.66, p < 0.001) and length of hospital stay (WMD -3.57 days, 95 % CI -5.17 to -1.98 days, p < 0.001). Meanwhile, MIPD group has a higher R0 resection rate (OR 1.47, 95 % CI 1.18-1.82, p < 0.001) and more lymph nodes harvest (WMD 1.74, 95 % CI 1.03-2.45, p < 0.001). However, it had longer operation time (WMD 83.91 min, 95 % CI 36.60-131.21 min, p < 0.001). There were no significant differences between the two procedures in morbidities (p = 0.86), postoperative pancreatic fistula (p = 0.17), delayed gastric empting (p = 0.65), vascular resection (p = 0.68), reoperation (p = 0.33) and mortality (p = 0.90). CONCLUSIONS: MIPD can be a reasonable alternative to OPD with potential advantages. However, further large-volume, well-designed RCTs with extensive follow-ups are suggested to confirm and update the findings of our analysis.