• Vad Gilliam posted an update 4 hours ago

    Laser manufacturing is a promising method for the design and preparation of high value-added materials. When the laser acts on the polymer precursors, some wonderful phenomena will always occur and accompanied by the generation of new substances. Herein, we report a top-down approach for the direct preparation of orange-yellow dye that is similar to psittacofulvins from commercial polymer resins by laser writing. Conjugated double bonds and micro-rough structures are formed simultaneously on laser-irradiated polymer substrate surfaces. The typical polyconjugated structures of psittacofulvin dyes were confirmed by micro-Raman and Raman imaging results. Temperature-dependent Fourier transform infrared and X-ray photoelectron spectroscopy further demonstrated the formation mechanism of laser-induced psittacofulvins dyes based on the chemical composition. Further, optical microscopy, laser confocal microscopy, and scanning electron microscopy were carried out to characterize the physical morphologies of laser-irradiated polymer substrates. A unique advantage of preparing psittacofulvins dye using laser writing is its simple steps, and the dye can be converted directly from the appropriate precursor substrate. Interestingly, the laser-irradiated polymer substrate surface undergoes color change. This laser-induced color patterning is attractive due to the characteristics of high precision, flexibility, and maskless; any patterns can be easily designed and produced on the polymer at desired positions.Mg2Sn is a potential thermoelectric (TE) material that exhibits environmental compatibility. In this study, we fabricated Sb-doped Mg2Sn (Mg2Sn1-xSb x ) single-crystal ingots and demonstrated the enhancement of TE performance via point defect engineering and Sb doping. The Mg2Sn1-xSb x single-crystal ingots exhibited considerably enhanced electrical conductivity because of the donor-doping effect in addition to high carrier mobility. Moreover, the Mg2Sn1-xSb x single-crystal ingots contained Mg vacancy (VMg) as a point defect. The introduced VMg and doped Sb atoms formed nanostructures, both acting as phonon-scattering centers. Consequently, lower lattice thermal conductivity was achieved for the Mg2Sn1-xSb x single-crystal ingots compared with polycrystalline counterparts. Owing to the significant enhancement in the electrical conductivity and the reduction in the lattice thermal conductivity, the maximum power factor of 5.1(4) × 10-3 W/(K2 m) and the maximum dimensionless figure of merit of 0.72(5) were achieved for the Mg2Sn0.99Sb0.01 single-crystal ingot, which are higher than those of single-phase Mg2Sn1-xSb polycrystals.Magnetoactive soft material (MASM) is distinguished for multifunctional shape manipulations under magnetic actuation, thereby holding a great promise in soft robotics, actuators, electronics, and metamaterials. However, the current research of MASM with continuum hard-magnetic profiles focuses little on the transformation mechanism, high dimensional shape transformation, and multistable locomotion. Herein, we developed a systematic methodology for programmable transformation and controllable locomotion of MASM with 3D-patterned continuum magnetization. An iterative computational model based on the equilibrium between magnetic torque and deformation-induced elastic torque was developed for precise prediction of MASM transformation. see more Multidimensional and complex shape manipulation ability of MASM was demonstrated by magnetically actuated transformations, including 1D to 2D, 2D to 3D, and 3D to 4D transformations of solid MASM, 2D to 3D pattern transformation of MASM-based elastin-like mesh, and 3D to 4D transformation of MASM-based cuboidal lattice. Multistable and controllable locomotion of MASM was verified by multimodal locomotion behaviors of a scallop-inspired robot for wall climbing in a dry frame and drug delivery in wet stomach, including roll, open, and close under self-locked and unlocked states.There is a continuing, urgent need for an ophthalmic (eye) drop for the clinical therapy of age-related macular degeneration (AMD), a leading cause of blindness. Here, we report the first formulation of an eye drop that is effective via autophagy for AMD treatment. This eye drop is based on a single natural product derivative (ACD), which is an amphiphilic molecule containing a 6-aminohexanoate group (H2N(CH2)5COO-). We demonstrate that this eye drop reverses the abnormal angiogenesis induced in a primate model of AMD that has the pathological characteristics close to that of human AMD. The ACD molecule was self-assembled in an aqueous environment leading to nanoparticles (NPs) about 9.0 nm in diameter. These NPs were encapsulated in calcium alginate hydrogel. The resulting eye drop effectively slowed the release of ACD and displayed extended release periods in both simulated blood (pH 7.4) and inflammatory (pH 5.2) environments. We show that the eye drop penetrated both the corneal and blood-eye barriers and reached the fundus. With low cellular toxicity, the drop targeted S1,25D3-membrane-associated rapid response steroid-binding protein (1,25D3-MARRS) promoting autophagy in a dose-dependent manner. In addition, the drop inhibited cell migration and tubular formation. On the other hand, when protein 1,25D3-MARRS was knocked down, the eye drop did not exhibit such inhibition functionalities. Our study indicates that the 6-aminohexanoate group on self-assembled NPs encapsulated in hydrogel leads to the positive in vivo outcomes. The present formulation offers a promising approach for clinical treatment of human AMD.Double electron-electron resonance (DEER, also known as PELDOR) and circular dichroism (CD) spectroscopies were explored for the purpose of studying the specificity of the conformation of peptides induced by their assembly into a self-recognizing system. The E and K peptides are known to form a coiled-coil heterodimer. Two paramagnetic TOAC α-amino acid residues were incorporated into each of the peptides (denoted as K** and E**), and a three-dimensional structural investigation in the presence or absence of their unlabeled counterparts E and K was performed. The TOAC spin-labels, replacing two Ala residues in each compound, are covalently and quasi-rigidly connected to the peptide backbone. They are known not to disturb the native structure, so that any conformational change can easily be monitored and assigned. DEER spectroscopy enables the measurement of the intramolecular electron spin-spin distance distribution between the two TOAC labels, within a length range of 1.5-8 nm. This method allows the individual conformational changes for the K**, K**/E, E**, and E**/K molecules to be investigated in glassy frozen solutions.