Precise Control Light Emission of PVDF-CH3NH3PbBr3-xClx Nanocrystalline Films Using a Cl-(CH3OH)n System.

Methylammonium lead halide perovskites with highly efficient pure-color or white-light generation have gained increasing scientific interest and promote the development of a great commercial opportunity in displays, lighting, and other applications. However, the poor stabilities, lead toxicity, and unfriendly solvents and ligands in the growth process severely restrict their commercial application. Here, we proposed a green method for preparing uniform and stable polymer-encapsulated photoluminescence (PL) tunable CH3NH3PbBr3-xClx NC thin films at room temperature. Utilizing the swelling effect between alcohol compounds and organic polymers and the ionization of NaCl in methanol solution, the anion exchange process can be achieved rapidly within 7 min. Moreover, the PL wavelengths of the CH3NH3PbBr3-xClx NCs films were precisely tuned with steps as fine as 2 nm. Experimental results showed that NaCl dissolved in methanol solution can form Cl-(CH3OH)n, which brings ionized Cl into the polymer-encapsulated CH3NH3PbBr3 NCs film for CH3NH3PbBr3-xClx NCs film growth. Based on the swelling and anion exchange dynamics, a modified NaCl-CH3OH-MABr solution system was developed to trigger CH3NH3PbBr3-xClx NCs film PL emission tuning from 528 to 463 nm with several-fold intensity enhancement. The realization of precisely controlled photoluminescence from the perovskite nanocrystal film would have wide applications in the optical and imaging fields.

Genome-wide identification of XTH gene family in Musa acuminata and response analyses of MaXTHs and xyloglucan to low temperature.

Banana (Musa spp.) production is seriously threatened by low temperature (LT) in tropical and subtropical regions. Xyloglucan endotransglycosylase/hydrolases (XTHs) are considered chief enzymes in cell wall remodelling and play a central role in stress responses. However, whether MaXTHs are involved in the low temperature stress tolerance in banana is not clear. Here, the identification and characterization of MaXTHs were carried out, followed by prediction of their cis-acting elements and protein-protein interactions. In addition, candidate MaXTHs involved in banana tolerance to LT were screened through a comparison of their responses to LT between tolerant and sensitive cultivars using RNA-Seq analysis. Moreover, immunofluorescence (IF) labelling was employed to compare changes in the temporal and spatial distribution of different types of xyloglucan components between these two cultivars upon stress. In total, 53 MaXTHs have been identified, and all were predicted to be located in the cell wall, 14 of them also in the cytoplasm. Only 11 MaXTHs have been found to interact with other proteins. Among 16 MaXTHs with LT responsiveness elements, MaXTH26/29/32/35/50 (Group I/II members) and MaXTH7/8 (Group IIIB members) might be involved in banana tolerance to LT stress. IF results suggested that the content of xyloglucan components recognized by CCRC-M87/103/104/106 antibodies might be negatively related to banana chilling tolerance. In conclusion, we have identified the MaXTH gene family and assessed cell wall re-modelling under LT stress. These results will be beneficial for banana breeding against stresses and enrich the cell wall-mediated resistance mechanism in plants to stresses.

Spatiotemporal evolution of ultrafast photocarrier dynamics across WS2-ReS2 lateral interface.

2D lateral heterostructures possess atomically sharp lateral interfaces, while understanding of their ultrafast photocarrier dynamics from a spatiotemporal viewpoint is rather elusive. In this study, we have investigated the spatiotemporal evolution of photocarrier dynamics across the 1D lateral interface of a WS2-ReS2 2D lateral heterostructure utilizing femtosecond laser pump-probe. The nontrivial band offset across the 1D lateral interface markedly mediates the spatiotemporal photocarrier transfer and transport processes. Subsequently, a hole accumulation region on the WS2 side and an electron accumulation region (1DEG) on the ReS2 side have been spatially identified by correlating ultrafast photocarrier signals. The measured width of the unilateral depletion region is 1360 ± 160 nm. Our work has provided substantial insights into mediated photocarrier dynamics in the 2D lateral heterostructure, which will benefit explorations in 2D interfacial physics and 2D lateral optoelectronic devices.

Research progress on the effects of SGLT2 inhibitors on multiple metabolic disorders in metabolic syndrome. / SGLT2æŠ‘åˆ¶å‰‚å¯¹ä»£è°¢ç»¼åˆå¾ç›¸å ³ä»£è°¢ç´Šä¹±çš„ä½œç”¨ç ”ç©¶è¿›å±•.

Metabolic syndrome (MS) is a complex group of metabolic disorders with an increasing global incidence rate, posing a serious threat to human health. Currently, there is no specific effective drug for its clinical treatment. Sodium-glucose linked transporter 2 (SGLT2) inhibitors are a new class of oral hypoglycemic drugs. They not only promote urinary glucose excretion by inhibiting the reabsorption of glucose by renal proximal convoluted tubule epithelial cells, thereby reducing blood glucose in a non-insulin-dependent manner, but also reduce blood glucose by improving the function of islet ß cells, reducing inflammatory responses, and inhibiting oxidative stress. In addition, SGLT2 inhibitors can also reduce body weight through osmotic diuresis and increased fat metabolism; reduce blood pressure by inhibiting excessive activation of sympathetic nervous system and improving vascular function; improve blood lipids by increasing degradation of triglyceride; reduce blood uric acid by promoting uric acid excretion in kidney and intestine and reducing uric acid synthesis. Therefore, this article reviews the improvement effects of SGLT2 inhibitors on multiple metabolic disorders in MS and its related regulatory mechanisms.

Effect of Extrusion on Mechanical Property, Corrosion Behavior, and In Vitro Biocompatibility of the As-Cast Mg-Zn-Y-Sr Alloy.

The effect of extrusion on the microstructure, mechanical property, corrosion behavior, and in vitro biocompatibility of as-cast Mg-1.5Zn-1.2Y-0.1Sr (wt.%) alloy was investigated via tensile tests, electrochemical methods, immersion tests, methylthiazolyl diphenyltetrazolium bromide (MTT), and analytical techniques. Results showed that the as-cast and as-extruded Mg-1.5Zn-1.2Y-0.1Sr alloys comprised an α-Mg matrix and Mg3Y2Zn3 phase (W-phase). In the as-cast alloy, the W-phase was mainly distributed at the grain boundaries, with a small amount of W-phase in the grains. After hot extrusion, the W-phase was broken down into small particles that were dispersed in the alloy, and the grains were refined considerably. The as-extruded alloy exhibited appropriate mechanical properties that were attributed to refinement strengthening, dispersion strengthening, dislocation strengthening, and precipitation strengthening. The as-cast and as-extruded alloys exhibited galvanic corrosion between the W-phase and α-Mg matrix as the main corrosion mechanism. The coarse W-phase directly caused the poor corrosion resistance of the as-cast alloy. The as-extruded alloy obtained via hydrogen evolution and mass loss had corrosion rates of less than 0.5 mm/year. MTT, high-content screening (HCS) analysis, and cell adhesion tests revealed that the as-extruded alloy can improve L929 cell viability and has great potential in the field of biomedical biodegradable implant materials.

Visual and quantitative lateral flow immunoassay based on Au@PS SERS tags for multiplex cardiac biomarkers.

Rapid and sensitive detection of multiple biomarkers by lateral flow immunoassay (LFIA) remains challenging for signal amplification for commonly used nanotags. Herein, we report a novel LFIA strip for visual and highly sensitive analysis of two cardiac biomarkers based on functionalized gold nanoparticles @ polystyrene microsphere (Au@PS）microcavity as surface-enhanced Raman scattering (SERS) tags. Antibody-modified Au@PS was designed as a SERS label. The evanescent waves propagating along the surface of the PS microcavity and the localized surface plasmons of the gold nanoparticles were coupled to enhance the light-matter interaction synergistically for Raman signal enhancement. In this strategy, the proposed Au@PS SERS tags-based LFIA was carried out to quantify the content of the heart failure and infarct biomarkers synchronously within 15 min and get the limits of detection of 1 pg/mL and 10 pg/mL for cardiac troponin I (cTnI) and N-terminal natriuretic peptide precursor (NT-proBNP), respectively. The results demonstrated 10-20 folds more sensitivity than that of the standard colloidal gold strip and fluorescent strip for the same biomarkers. This novel quantitative LFIA shows promise as a high-sensitive and visual sensing method for relevant clinical and forensic analysis.

Changes in hemicellulose metabolism in banana peel during fruit development and ripening.

Hemicellulose is key in determining the fate of plant cell wall in almost all growth and developmental stages. Nevertheless, there is limited knowledge regarding its involvement in the development and ripening of banana fruit. This study investigated changes in the temporal-spatial distribution of various hemicellulose components, hemicellulose content, activities of the main hydrolysis enzymes, and transcription level of the main hemicellulose-related gene families in banana peels. Both hemicellulose and xylan contents were positively correlated to the fruit firmness observed in our previous study. On the contrary, the xylanase activity was negatively correlated to xylan content and the fruit firmness. The vascular bundle cells, phloem, and cortex of bananas are abundant in xyloglucan, xylan, and mannan contents. Interestingly, the changes in the signal intensity of the CCRC-M104 antibody recognizing non-XXXG type xyloglucan are positively correlated to hemicellulose content. According to RNA-Seq analysis, xyloglucan and xylan-related genes were highly active in the early stages of growth, and the expression of MaMANs and MaXYNs increased as the fruit ripened. The abundance of plant hormonal and growth-responsive cis-acting elements was detected in the 2 kb upstream region of hemicellulose-related gene families. Interaction between hemicellulose and cell wall-specific proteins and MaKCBP1/2, MaCKG1, and MaHKL1 was found. The findings shed light on cell wall hemicellulose's role in banana fruit development and ripening, which could improve nutrition, flavor, and reduce postharvest fruit losses.

Strong anisotropic third-harmonic generation in layered violet phosphorus.

We demonstrate that layered violet phosphorus, an emerging 2D semiconductor, undergoes strong anisotropic third-harmonic generation (THG). Polarization dependence of in-plane THG presents a cruciate-flower-shaped curve. Through theoretical modeling of the in-plane THG response, done by considering crystalline symmetry of violet phosphorus, we successfully quantify four non-zero third-order nonlinear optical susceptibility tensor elements. From control experiments, the magnitude of third-order nonlinear optical susceptibility |χ3| is calculated to be about 4.0 × 10-19 m2 V-2, which is comparable to those of conventional 2D layered semiconductors. These results indicate that the layered violet phosphorus can serve as an ideal building block for nonlinear optical applications.

Dynamic change of neutrophil-to-lymphocyte ratio and its predictive value of prognosis in acute ischemic stroke.

OBJECTIVE: The present research aimed to explore the dynamic change of the neutrophil-to-lymphocyte ratio (NLR) and its relationship with functional outcome following an acute ischemic stroke (AIS), whether receiving intravenous thrombolysis (IVT) or not. METHODS: We retrospectively analyzed data that were prospectively acquired from patients with AIS treated with IVT or not. For patients receiving IVT, the NLR was based on a blood test performed prior to IVT (d0) and at different time points after disease onset (d1, d3, d7). In addition, in the non-IVT group, the NLR was obtained at different time points after disease onset (d1, d3, d7). Follow-ups were performed 3 months after onset via telephone. In addition, a good outcome was defined as a modified Rankin scale (mRS) ≤1; a poor outcome means 2 ≤ mRS ≤ 6. RESULTS: A total of 204 AIS patients were included in this study. The NLR presented a dynamic change as it increased to its peak at day 1 and gradually declined to its baseline at day 7, no matter whether patients were receiving IVT or not. Patients with poor outcomes have a higher NLR at various time points. The results of multivariate logistic regression analysis demonstrated that the National Institutes of Health Stroke Scale (NIHSS), NLR d1, NLR d3, and NLR d7 were independently associated with functional outcomes. The area under the receiver operating characteristic curve of NLR in predicting outcomes was as follows: NLR d3 demonstrated robust predictive power within the IVT therapy cohort, whereas NLR d7 was predictive in the non-IVT cohort. However, the most potent predictor emerged as the combination of NIHSS and NLR. CONCLUSION: NLR has the potential to predicate diagnosis for AIS, especially when combined with the NIHSS score.