Metal-Free C(sp³)–H Azidation in a Radical Strategy for the Synthesis of 3‑Azido-2-oxindoles at Room Temperature

A novel and environmentally attractive C­(sp3)–H azidation of 2-oxindoles involving the formation of a C–N bond was developed. This methodology achieved for the first time 3-azido-2-oxindole construction under metal-free conditions at room temperature via a radical strategy. PhI­(OAc)2 was used as the oxidant and Et3N was used as the additive in this transformation. Furthermore, the mechanistic study indicated that this azidation involved a radical process

A Thermally Stable Undulated Coordination Layer Showing a Sequentially Interweaving 2D → 3D Net as a Turn-On Sensor for Luminescence Detection of Al³⁺ in Water

A Zn coordination polymer, [Zn­(H2dhbdc)­(Cz-3,6-bpy)]n (1, H4dhbdc = 2,5-dihydroxyterephthalic acid, Cz-3,6-bpy = 3,6-bis­(pyridin-4-yl)-9H-carbazole), showing high thermal stability up to 407 °C, has been prepared under hydro­(solvo)­thermal conditions. Compound 1 has a two-dimensional (2D) undulated layer structure regarded as the topological sql grid, where the tetrahedral Zn­(II) centers act as 4-connected nodes connecting by H2dhbdc2– and Cz-3,6-bpy ligands as linkers. Interestingly, the 2D undulated layers expanding in the bc plane are sequentially interwoven with each other in an offset manner along the a-axis, resulting in a condensed polyinterweaving 2D → 3D net. Compound 1 emits weak fluorescence at 522 nm in water suspensions; the intensity can be significantly enhanced by adding Al3+ ions, with low limit of detection (LOD) of 0.62 μM and high anti-interference ability over numerous competitive metal ions except Fe3+ ions. Moreover, the detection performance of 1 toward Al3+ retains high luminescence stability and reusability, being as an excellent candidate for Al3+ detection over a long period. Spectroscopic evidence from XRPD, EDS, IR, and XPS suggest the occurrence of weak framework–analyte interactions between the H2dhbdc2– ligand units in 1 and the Al3+ ions, resulting in luminescence turn-on sensing

MetaHDR: Single Shot High-Dynamic Range Imaging and Sensing using a Multifunctional Metasurface

We present MetaHDR, which is a single-shot high-dynamic range (HDR) imaging and sensing system using a multifunctional metasurface. The metasurface is capable of splitting an incident beam into multiple focusing beams with different amounts of power, simultaneously forming multiple low dynamic range (LDR) images with distinct irradiance on a photosensor. Then, the LDR images are jointly processed using a gradient-based HDR fusion algorithm, which is shown to be effective in attenuating the residual light artifacts incurred by the metasurface and the lens flare. MetaHDR achieves single-shot HDR photography and videography that increases the dynamic range by at least 50 dB compared to the original dynamic range of the photosensor. It can also perform single-shot HDR sensing, including reflectance calibration and surface curvature estimation of reflective materials. MetaHDR's demonstrated functionalities could be broadly applied in surveillance and security, microscopic imaging, advanced manufacturing, etc

Combination of the TC-HT and the CGA or EGCG induces mitochondrial dysfunction.

(A) Flow cytometric analysis of MMP using DiOC6(3) after treatment with the TC-HT (10 cycles), 0.05% DMSO (vehicle control), CGA (200 μM), and EGCG (20 μM) alone or in combination (TC-HT + DMSO, TC-HT + CGA, TC-HT + EGCG) for 24 h. The M1 regions indicate the cells with the loss of MMP. (B) Histogram represents the percentage of cells in the M1 region. Data are presented as mean ± S.D. in triplicate. (**p p < 0.001 compared with the untreated control).</p

Cation-Size-Mismatch Tuning of Photoluminescence in Oxynitride Phosphors

Red or yellow phosphors excited by a blue light-emitting diode are an efficient source of white light for everyday applications. Many solid oxides and nitrides, particularly silicon nitride-based materials such as M₂Si₅N₈ and MSi₂O₂N₂ (M = Ca, Sr, Ba), CaAlSiN₃, and SiAlON, are useful phosphor hosts with good thermal stabilities. Both oxide/nitride and various cation substitutions are commonly used to shift the emission spectrum and optimize luminescent properties, but the underlying mechanisms are not always clear. Here we show that size-mismatch between host and dopant cations tunes photoluminescence shifts systematically in M_1.95Eu_0.05Si_5–<i>x</i>Al_<i>x</i>N_8–<i>x</i>O_<i>x</i> lattices, leading to a red shift when the M = Ba and Sr host cations are larger than the Eu²⁺ dopant, but a blue shift when the M = Ca host is smaller. Size-mismatch tuning of thermal quenching is also observed. A local anion clustering mechanism in which Eu²⁺ gains excess nitride coordination in the M = Ba and Sr structures, but excess oxide in the Ca analogues, is proposed for these mismatch effects. This mechanism is predicted to be general to oxynitride materials and will be useful in tuning optical and other properties that are sensitive to local coordination environments

Combination of the TC-HT and the CGA or EGCG induces apoptosis in PANC-1 cells.

The apoptosis analysis for the cells following the treatment with the TC-HT (10 cycles), 0.05% DMSO (vehicle control), CGA (200 μM), and EGCG (20 μM) alone or in combination (TC-HT + DMSO, TC-HT + CGA, TC-HT + EGCG) for 24 h. (A) Flow cytometric detection of the apoptosis with Annexin V-FITC/PI double staining. (B) Histogram quantifying the percentage of PANC-1 cells in early and late apoptosis. (C) The nuclei morphology alterations (arrow) were examined using DAPI staining. Data are presented as mean ± S.D. in triplicate. (**p p < 0.001 compared with the untreated control).</p

Synergy quotient for CGA or EGCG in combination with the TC-HT.

Synergy quotient for CGA or EGCG in combination with the TC-HT.</p

Exposure to the TC-HT via a temperature controller.

(A)(B) Schematic of experiment setup and the TC-HT programs setting. (C) The actual temperature recorded every 20 sec in the PANC-1 cells throughout the exposure period.</p

Bromelain treatment suppressed proliferation of HCT116 cells in a zebrafish model.

The inhibitory effect of bromelain on colorectal cancer growth was confirmed using a xenotransplantation assay performed in a zebrafish system. (A) In HCT116 cells, the percentage of cells in embryos decreased after exposure to bromelain from 72% (vehicle) to 47% (100 μg/ml) and 18% (300 μg/ml). An increase in the percentage of cells in embryos was found from 22% (vehicle) to approximately 82% (bromelain). (B) In DLD-1 cells, an increase in the percentage of cells in embryo was found from 6% (vehicle) to approximately 94% (bromelain). The figure is representative of the fluorescence intensity in embryos. Data are presented as the mean±SD. ** p<0.001.</p

DataSheet_2_The Spatial Variation in Chlorophyte Community Composition From Coastal to Offshore Waters in a Subtropical Continental Shelf System.csv

Globally, the continental shelf occupies less than 10% of the total sea surface, but supports substantial primary production and fisheries. Photosynthetic picoeukaryotes (PPE) are important primary producers in marine ecosystems, and chlorophytes make a significant contribution to PPE abundance. Although the distribution of chlorophytes has been widely studied, little is known about how their community composition varies along the coastal-offshore gradient in subtropical continental shelf waters. To better understand their spatial variations, we employed metabarcoding data of 18S rRNA V4 gene to examine chlorophyte composition within the surface and deep chlorophyll maximum (DCM) layers over the continental shelf in the East China Sea (ECS) with high-resolution sampling. Our results indicate a higher chlorophyte diversity in the surface layer than in the DCM. In addition, we found that chlorophytes in oligotrophic Kuroshio surface water were the most diverse, with a higher percentage of Chloropicophyceae, prasinophyte clade V, prasinophyte clade IX, Palmophyllophyceae and Chlorodendrophyceae. In more eutrophic waters along the coast and within the DCM layer, chlorophytes were dominated by Mamiellophyceae. A significant spatial variation in community composition occurred along the nutrient gradient in the subtropical continental shelf ecosystem, varying from Mamiellophyceae-dominant in coastal water to Chloropicophyceae-dominant in offshore water. Furthermore, at a low saline coastal station, which had the lowest chlorophyte diversity, Picochlorum (Trebouxiophyceae) was dominant. Overall, chlorophyte diversity was positively correlated with temperature, and negatively correlated with silicate concentration. This study revealed that terrestrial input into continental systems influences chlorophyte diversity in the subtropical northwestern Pacific Ocean.</p