Imaging of wrist when wearing the entire system and walking.

A volunteer performs the vascular imaging of his wrist when wearing the entire system and walking in a room

Uncovering the Interaction between Intracellular Telomerase Activity and Hydrogen Peroxide during Cancer Cell Apoptosis Utilizing a Dual-Color Fluorescent Nanoprobe

Uncovering the intrinsic interaction of different bioactive species, i.e., reactive oxygen species (ROS) and telomerase, is of great importance because they play interrelated and interdependent biological roles in living organisms. Nevertheless, exploration of the intracellular ROS/telomerase cross-talk by effective and noninvasive methods remains a great challenge, as it is difficult to simultaneously detect different types of biomolecules (i.e., active small molecules and proteins) in living cells. To address this issue, herein, we report, for the first time, a novel fluorescent nanoprobe for simultaneous determination and in situ imaging of telomerase activity and hydrogen peroxide (H2O2) in living cells. With the advantage of high sensitivity and good specificity, this newly fabricated nanoprobe was successfully applied to precisely visualize and monitor the changes in telomerase activity and H2O2 concentration in cancer cells. More significantly, by employing the nanoprobe as a one-step incubation tool, it is found that there is a cross-talk between H2O2 and telomerase activity in the drug-induced cancer cells’ apoptosis process, which provides valuable information for gaining fundamental insights into the relationship between ROS and telomerase activity in cancer treatments. This work affords a promising method for revealing the relevant regulatory mechanisms and roles of ROS and telomerase activity in the occurrence, evolvement, and treatment of diseases

Images at the same position during the adjustment of optical focus.

The observed images at the same position during the entire movement of the optical focus

Switchable Plasmonic Chirality for Light Modulation: From Near-Field to Far-Field Coupling

This paper describes a quasi-planar chiral metamaterial of metal–insulator–metal (MIM) tetramer arrays that support multiplasmon modes from a hybridization scheme to achieve significant chiroptical responses with the largest circular dichroism (CD) value of 42%. The chiroptical responses can be actively switched on and off by tuning the field coupling regime from near field to far field through the insulator (or spacer) thickness. Numerical calculations demonstrate that near-field coupling of the hybridized plasmons on the stacked metallic tetramers governs the chiroptical responses at small insulator thickness (tSiO2 < 160 nm). In contrast, far-field coupling of the plasmon radiations dominates at large spacing (tSiO2 > 160 nm) as phase retardation plays a crucial role. The quasi-planar chiral metamaterial with tunable plasmonic chirality enables efficient light modulation for polarization conversion: from circular to elliptical/linear polarization

Synthesis and Properties of Sulfonated Ethylene-Conjugated Alkene Copolymers for High-Performance Proton Exchange Membranes

The synthesis and properties of a family of high-performance polyethylene–proton exchange membranes (PE-PEMs) are discussed. The combination of copolymerization of ethylene with conjugated alkenes (including isoprene, butadiene, and myrcene) by scandium catalysts and further transformation of the carbon–carbon double bonds of the resulting copolymers into sulfonic acid groups and cross-linked structures efficiently, and in an environmentally friendly manner, affords PE-PEMs with well-controlled molecular structures. A systematic structure–property study of PE-PEMs indicates that (i) the block distribution of sulfonic acid groups in long polyethylene blocks, (ii) the incorporation of sulfonic acid groups by carbon–carbon double bonds of 3,4-polyisoprene, and (iii) the introduction of an alkyl chain thiol cross-linked structure are beneficial to the formation of a developed phase-separation structure, which is advantageous in improving the dimension and oxidation stabilities, conductivity, proton/methanol selectivity, and mechanical properties of PE-PEMs. The most desirable PE-PEMs with 30 mol % block distributed sulfonic acid groups and a 6 mol % cross-linked structure affords a good combination of desirable properties, including conductivity (188 mS cm–1), swelling ratio (23%), fuel barrier properties (proton/methanol selectivity: 0.71 × 105 S s cm–3; hydrogen penetration: 11.1 Barrer), mechanical properties (tensile strength of 45 MPa, elongation of 273%), and oxidation stability (maintain over 73.8% conductivity with 24 h). A single cell with desirable PE-PEM shows open-circuit voltage and peak power density of 0.98 V and 424 mW cm–2, respectively

Dissection of the Enzymatic Process for Forming a Central Imidazopiperidine Heterocycle in the Biosynthesis of a Series <i>c</i> Thiopeptide Antibiotic

Thiopeptide antibiotics are a family of ribosomally synthesized and posttranslationally modified peptide natural products of significant interest in anti-infective agent development. These antibiotics are classified into five subfamilies according to differences in the central 6-membered heterocycle of the thiopeptide framework. The mechanism through which imidazopiperidine, the most heavily functionalized central domain characteristic of a series c thiopeptide, is formed remains unclear. Based on mining and characterization of the genes specifically involved in the biosynthesis of Sch40832, we here report an enzymatic process for transforming a series b thiopeptide into a series c product through a series a intermediate. This process starts with F420-dependent hydrogenation of the central dehydropiperidine unit to a saturated piperidine unit. With the activity of a cytochrome P450 monooxygenase, the piperidine-thiazole motif of the intermediate undergoes an unusual oxygenation-mediated rearrangement to provide an imidazopiperidine heterocycle subjected to further S-methylation and aldehyde reduction. This study represents the first biochemical reconstitution of the pathway forming a stable series c thiopeptide

Enhanced Carrier Dynamics of CsPbBr₃ Nanocrystals Enabled by Short-Ligand Ethanedithiol for Efficient Photoelectrocatalytic Photoanodes

Photoelectrochemical (PEC) water splitting is a potential solution for a low-carbon society and clean energy storage due to its ability to produce hydrogen and oxygen. However, the slow oxidation half-reaction of the process has limited its overall efficacy, necessitating the development of an efficient photoanode. Colloidal CsPbBr3 nanocrystals (NCs) have been identified as promising candidates due to their high light absorption and valence band position. However, the presence of the electrical insulator, long-chain oleate molecules, on the surface of the CsPbBr3 NCs has hindered efficient charge carrier separation and transport. To solve this problem, short-chain 1,2-ethanedithiol (EDT) ligands were used to replace the oleate ligands on the surface of the CsPbBr3 NCs through a solid-state ligand exchange method. This resulted in a reduction of the nanocrystal spacing and a cross-linking reaction, which improved the photogenerated carrier separation and transport while still passivating the dangling bonds on the CsPbBr3 NC surface. Ultimately, this led to a remarkable photocurrent density of 3.34 mA cm–2 (1.23 VRHE), which was 5.2 times higher than that of the pristine oleate-CsPbBr3 NC (0.64 mA cm–2)-based device. This work presents an efficient way of developing inorganic lead halide perovskite colloidal nanocrystal-based photoanodes through surface ligand engineering

Amplified Spontaneous Emission and Lasing from Zn-Processed AgIn₅S₈ Core/Shell Quantum Dots

I–III–VI ternary quantum dots (QDs) have emerged as favorable alternatives to the toxic II–VI QDs for optoelectronic and biological applications. However, their use as optical gain media for microlasers is still limited by a low fluorescence efficiency. Here, we demonstrate amplified spontaneous emission (ASE) and lasing from colloidal QDs of Zn-processed AgIn5S8 (AIS) for the first time. The passivation treatment on the AIS QDs yields a 3.4-fold enhancement of fluorescence quantum efficiency and a 30% increase in the two-photon absorption cross section. ASE is achieved from the AIS/ZnS core/shell QD films under both one- and two-photon pumping with a threshold fluence of ∼84.5 μJ/cm2 and 3.1 mJ/cm2, respectively. These thresholds are comparable to the best optical gain performance of Cd based-QDs reported in the literature. Moreover, we demonstrate a facile whispering-gallery-mode microlaser of the core/shell QDs with a lasing threshold of ∼233 μJ/cm2. The passivated AIS QDs can be promising optical gain media for photonic applications

Strong Photon–Plasmon Coupling for High-Order Waveguide–Plasmon Polaritons

Strong light–matter interaction enables significant modification of fundamental properties of coupled matter, such as chemical reaction rate, conductivity, and energy transfer, which is crucial for designing efficient light-emitting devices and low-threshold lasing. Strong photon–plasmon coupling in metallic photonic crystal slabs has been extensively exploited for band gap engineering, third-harmonic generation, and enhanced Faraday rotation. However, current research focuses on coupling the waveguide mode to the dipolar plasmon that is inherently lossy and has a small quality factor. This paper reports a metallic photonic crystal slab constructed by placing split nanoring dimer arrays onto an indium–tin–oxide (ITO) waveguide to excite dipolar and high-order waveguide–plasmon polaritons with large Rabi splitting. The dimer unit comprises two identical split nanorings and supports dipolar and high-order hybrid plasmons derived from structural symmetry breaking and plasmon hybridization. Arrangement of the dimer into arrays on the ITO slab creates a strong coupling channel for the hybrid plasmons and the waveguide mode to generate dipolar and high-order waveguide–plasmon polaritons with distinct anticrossing dispersions. The strong coupling effect remarkably modifies the plasmon oscillations by altering the directions and strength of their dipole moment. We used the strongly coupled plasmons with narrow spectral line shapes as a refractive index sensor and obtained the largest sensitivity of 250 nm·RIU–1 and a figure of merit of 11.62 RIU–1

Quantitative changes in TRPV1 expression at the ultrastructural level in morphine withdrawal groups.

<p>High-power electron micrographs from the NAc of different groups showing TRPV1 immunogold labeling in the axon terminals forming asymmetric, excitatory-type synapses (A) and symmetric, inhibitory-type synapses (B). In the morphine withdrawal groups the number of gold particles on terminals forming asymmetric synapses increased (A). Graph (C) shows changes in the average number of TRPV1-positive asymmetric and symmetric synapses in each group. The number of TRPV1-positive asymmetric synapses in the morphine withdrawal groups was significantly higher than the control group. However, no difference was found in the normalized number of TRPV1-positive symmetric synapses among all groups. The number of TRPV1-positive symmetric synapses of control were 4.72±0.77, 4.72±0.47 and 4.74±1.00 for 1 d, 1 w and 3 w group respectively. The number of TRPV1-positive asymmetric synapses of control were 7.74±1.38, 7.75±0.77 and 7.74±1.28 for 1 d, 1 w and 3 w group respectively. Graph (D) shows the normalized number of gold particles in TRPV1-positive asymmetric and symmetric synapses. No difference appeared in the normalized number of gold particles in TRPV1-positive symmetric synapses. In contrast, a significant increase occurred in the normalized number of gold particles in TRPV1-positive asymmetric synapses of morphine withdrawal groups versus control group. The normalized number of gold particles in TRPV1-positive symmetric synapses of control were 0.68±0.17, 0.68±0.03 and 0.69±0.04 for 1 d, 1 w and 3 w group respectively. The normalized number of gold particles in TRPV1-positive asymmetric synapses of control were 0.78±0.07, 0.79±0.13 and 0.79±0.03 for 1 d, 1 w and 3 w group respectively. Scale: 200 nm. Data represent Mean±SEM (n = 3), *<i>p</i><0.05, <i>vs</i> control group.</p