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Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) offer distinct advantages over traditional NIR light sources in the miniaturization of spectrometers. Nevertheless, the lack of highly efficient NIR phosphors with a large bandwidth hinders their practical applications. Herein, a novel Cr3+-doped (Ca1−xLix)(Mg1−xScx)Si2O6 phosphor with a broadened emission has been successfully developed by controlling the lattice disorder via [Li+–Sc3+] chemical unit substitution in CaMgSi2O6:Cr3+. Upon exciting the phosphor with 455 nm blue light, (Ca0.5Li0.5)(Mg0.5Sc0.5)Si2O6:4%Cr3+ exhibits notable NIR emission centered at approximately 847 nm, featuring a full width at half-maximum (FWHM) of 172 nm. The disordered occupation of Ca2+/Li+ and Mg2+/Sc3+ enhances the electron–phonon coupling effect, resulting in a broader emission of (Ca0.5Li0.5)(Mg0.5Sc0.5)Si2O6:Cr3+ compared with that of CaMgSi2O6:Cr3+. In order to further broaden the emission band, an energy transfer (ET) strategy is explored. By leveraging the ET process from Cr3+ to Yb3+, the FWHM of (Ca0.5Li0.5)(Mg0.5Sc0.5)Si2O6:4%Cr3+,0.4%Yb3+ is significantly increased up to 264 nm. The phosphor possesses a quantum yield of 46% and a thermal stability of 69% at 423 K. The NIR pc-LED utilizing the (Ca0.5Li0.5)(Mg0.5Sc0.5)Si2O6:Cr3+,Yb3+ phosphor yields an NIR optical power of 57.31 mW at a driving current of 300 mA, and achieves 10.01% photoelectric conversion efficiency at 25 mA, exhibiting promising potential for application in bio-imaging and food analysis. [ABSTRACT FROM AUTHOR]

Defect engineering, used to scatter phonons, is a widely used methodology to suppress the lattice thermal conductivity and improve the thermoelectric performance. Thus, understanding the effects of defects on the lattice thermal conductivity is an essential issue. However, the current thermal conductivity calculation methods are limited by either efficiency or accuracy in dealing with the defects: achieving the high order force constants for solving the phonon Boltzmann transport equations is time consuming; the traditional Debye–Callaway (DC) model ignores the local geometry relaxations around defects. The potentials used in molecular dynamics simulations are usually the empirical potentials. Utilizing the machine learning methodology, we train the deep neural network potential (NNP) for the defected PbTe compound, a remarkable thermoelectric material with large potential applications. The NNP is validated using the static energy, mechanical properties, kinetic properties, and phonon dispersions of PbTe systems. With the accurate NNP, the corresponding lattice thermal conductivity is then calculated using the molecular simulations (MD) under the Green–Kubo (GK) approximations, which balances the computational cost and accuracy. For the pristine PbTe compound, the simulated lattice thermal conductivities are in good agreement with experimental measurements. For the intrinsic point defected PbTe system, our NNP + MD + GK produces reasonable lattice thermal conductivities compared to those from the DC model. By comparing the simulated results with those using the DC model, we provide a strain correction factor f0 in the DC model of defect strain effects on the lattice thermal conductivity. From our simulations, the grain boundaries in PbTe scatter the medium wavelength phonons and significantly suppress the lattice thermal conductivity. In addition, the synergistic effect of twin boundaries and point defects could further reduce the lattice thermal conductivity. Our work provides a theoretical methodology not only to simulate heat transport in the defected material but also understand the phonon scattering behaviors of different defects. [ABSTRACT FROM AUTHOR]

Vitrimers can undergo topological rearrangement of their dynamic covalent networks, which endows these materials with the ability to be reprocessed and recycled. Utilizing the concept of vitrimers to develop novel functional applications for traditional materials is currently an interesting research focus. Here, we present an example of novel epoxy–polyurea based vitrimers equipped with dynamic aromatic disulfide linkages, meaning the structure and thermomechanical properties can be adjusted through controllable network reconfiguration. The stress relaxation behaviour of the epoxy–polyurea vitrimers correlates significantly with their network composition. After recycling, a narrow glass transition temperature and a higher elastic modulus were observed for the epoxy–polyurea vitrimers with the formation of homogeneous and orderly networks, while heterogeneous networks could be created by integrating epoxy–polyurea vitrimers with distinct glass transition temperatures through a "powder blend" method. Using the controllable network configuration strategy, different epoxy–polyurea vitrimers can be incorporated at the macroscopic and microscopic scale. Correspondingly, a multi-shape memory effect could also be achieved by post-processing via constructing isolation structures in different scales, using "powder blend" and "powder welding" methods. [ABSTRACT FROM AUTHOR]

Photothermal therapy (PTT) based on semiconducting polymer nanoparticles (SPNs) is a promising strategy to treat solid tumors, but its ability to combine with chemotherapy for immune remodeling to efficiently suppress metastatic cancers has rarely been studied. Here, we demonstrate that PTT combined with chemotherapy can efficiently elicit immunity to suppress metastatic tumor growth. Specifically, we rationally designed a new SPN (PDPSe NPs) as a photothermal agent for PTT with a large mass extinction coefficient in the near-infrared region (e.g., 44.9 L g−1 cm−1 at 808 nm), high photothermal conversion efficiency (62.5%) and excellent biocompatibility. A hypoxia-activated anti-tumor drug, tirapazamine (TPZ), was selected for chemotherapy. Strikingly, the combination therapy not only induced tumor cell death in the primary tumor, but also effectively suppressed the growth of distant tumors (mimicking metastatic tumors) without PTT. Importantly, the combined therapies exhibit synergistic effects on immune remodeling. Immunofluorescence data suggest that the inhibition of metastatic tumor growth is attributed to the immune remodeling triggered by PTT and chemotherapy. This work demonstrates a new paradigm of utilizing PTT together with hypoxia-activated drugs to effectively retard metastatic tumor growth. [ABSTRACT FROM AUTHOR]

To prepare a robust material with high self-healing capability under ambient conditions is still a great challenge. Herein, a novel self-healing polyurethane is developed via a dual-dynamic network design, in which multiple H-bonding and metal-coordinated bonds (zinc–imidazole interaction) were incorporated into a polyurethane matrix. Benefiting from the dual-dynamic network, the synthesized metallopolymers exhibit excellent mechanical properties, such as high tensile strength (from 6.68 MPa to 14.38 MPa), excellent stretchability (about 2000%) and superior toughness (from 55.61 MJ m−3 to 96.21 MJ m−3). Moreover, these metallopolymers show good self-healing capability. After healing under ambient conditions for 48 hours, the tensile strength and strain at break of PU-IZ/Zn-0.50 can reach up to 7.13 MPa and 1800%, respectively. The dual-dynamic crosslinked metallopolymers might provide a novel approach to design tough and self-healable materials for various industrial applications. [ABSTRACT FROM AUTHOR]

Selective structure and shape of Eu3+-doped monoclinic LaPO4and hexagonal LaPO4·1.5H2O nanocrystals were successfully synthesized by a hydrothermal method. It was found that the pH and temperature of the growth solution are two crucial factors in determining the structure and morphology of LaPO4nanocrystals. The properties of the Eu3+-doped LaPO4nanocrystals were characterized by XRD, SEM, TEM, XPS and UV-vis spectroscopy. [ABSTRACT FROM AUTHOR]

Crop diseases caused by pathogenic microorganisms pose severe threats to the global food supply. Effective diagnostic tools for timely determination of plant diseases become essential to the assurance of agricultural sustainability and global food security. Nucleic acid- and antibody-based molecular assays are gold-standard methodologies for the diagnosis of plant diseases, but the analyzing procedures are complex and laborious. The prominent physical or chemical properties of nanomaterials have enabled their use as innovative and high-performance diagnostic tools for numerous plant pathogens and other important disease biomarkers. Engineered nanomaterials have been incorporated into traditional laboratory molecular assays or sequencing technologies that offer notable enhancement in sensitivity and selectivity. Meanwhile, nanostructure-supported noninvasive detection tools combined with portable imaging devices ( e.g. , smartphones) have paved the way for fast and on-site diagnosis of plant diseases and long-term monitoring of plant health conditions, especially in resource-poor settings., Competing Interests: The authors declare no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

A fluorescent probe, PyCalix, which has two pyrene moieties at the lower rim of a calix[4]arene fixed in the cone conformation was synthesized and its complexation behavior with alkali and alkaline earth cations was studied by fluorescence spectrometry. The compound showed intramolecular excimer emission at approximately 480 nm in the fluorescence spectra. Upon complexation with alkaline earth metal cations, a decrease of excimer emission was observed. The decrease of excimer emission was accompanied by an increase of monomer emission of pyrenes at 397 nm. The order of complexation constants of PyCalix with metal ions was Sr(+ approximately Ca2+ > Ba2+ > Mg2+ > K+ > Na+ > Cs+ for all reagents. PyCalix doped polyvinyl chloride (PVC) membrane was fabricated and our results showed that this membrane can be used for selective detection of Sr2+.