Construction of Pt/Ni/NiFe2O4/C nanocomposite with one dimensional hollow structure for portable glucose sensing application.

Designing portable electrochemical sensors combined with highly efficient glucose oxidation electrodes offers a significant opportunity for convenient glucose detection. In this report, we present the design and preparation of platinum deposited Ni/NiFe2O4/Carbon composite (Pt/Ni/NiFe2O4/C) derived from Ni/Fe metal-organic frameworks (MOFs) followed by Pt deposition. Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electron microscopy (EM) were utilized to analyze the crystal structure, morphology, and chemical composition of the resulting materials. The glucose sensing capabilities of the optimal Pt/Ni/NiFe2O4/C-3 were assessed using amperometry methods on a smartphone-based portable device. Acting as a nonenzymatic glucose sensor, the Pt/Ni/NiFe2O4/C-3 electrode demonstrated notable sensitivity and a low limit of detection for glucose. The portable sensor exhibits high sensitivities of 131.88 µM mM cm-2 at low glucose concentration (3-500 µM) and 29.52 µA mM cm-2 at high glucose concentration (700-4000 µM), achieving a low detection limit of 1.1 µM (S/N = 3). The sensor also demonstrates enhanced selectivity and stability for detecting glucose. Furthermore, the portable sensor exhibits a clear step-ampere response in the detection of serum samples with satisfactory recovery ranging from 99.30 to 101.32%. This suggests the significant potential of portable glucose sensing applications.

Electrochemical sensors based on platinum-coated MOF-derived nickel-/N-doped carbon nanotubes (Pt/Ni/NCNTs) for sensitive nitrite detection.

As excess nitrite has a serious threat to the human health and environment, constructing novel electrochemical sensors for sensitive nitrite detection is of great importance. In this report, platinum nanoparticles were deposited on nickel-/N-doped carbon nanotubes, which were obtained through a self-catalytically grown process with Ni-MOF as precursors. The as-prepared Pt/Ni/NCNTs were applied as amperometric sensors and presented superior sensing properties for nitrite detection. Benefiting from the synergy of Pt and Ni/NCNTs, Pt/Ni/NCNTs displayed much wider detection ranges (0.5-40 mM and 40-110 mM) for nitrite sensing. The sensitivity is 276.92 µA mM-1 cm-2 and 224.39 µA mM-1 cm-2, respectively. The detection limit is 0.17 µM. The Pt/Ni/NCNTs sensors also showed good feasibility for nitrite sensing in real samples (milk and peach juice) analysis. The active Pt/Ni/NCNTs composites and facile fabrication technique may provide useful strategies to develop other sensitive nitrite sensors.

Radical Charge Population and Energy: Critical Role in Redox Potential and Cycling Life of Piperidine Nitroxyl Radical Cathodes in Aqueous Zinc Hybrid Flow Batteries.

Redox-active 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivatives have recently been investigated to expand the choice of catholyte for aqueous flow batteries (AFBs). However, the effects of substituent R in 4-position on redox potential and corresponding capacity fading mechanism are still unclear. Here, we conduct comparative studies of four R-TEMPO with R = -OH, -NH2, -COOH, and -NHCOCH3 in zinc hybrid AFBs. Experimental and theoretical analyses reveal that low-radical head charge population sum and radical energy, depending on R in 4-position, play a critical role in enhancing redox potential and cycling life of R-TEMPO. The electronic effect brought along by N-acetyl could redistribute the charge and lower systematic energy, making the ring-opening joint sturdy and therefore suppress the side reactions. Accordingly, the 4-NHCOCH3-TEMPO/Zn battery achieves a high capacity retention of >99.65%/day and an open-circuit voltage of 1.71 V. Our findings on the effects of substituent are greatly anticipated to boost the high-energy density, long-life, and eco-friendly TEMPO-based AFBs.

Puerarin ameliorates retinal ganglion cell damage induced by retinal ischemia/reperfusion through inhibiting the activation of TLR4/NLRP3 inflammasome.

AIMS: Retinal ischemia/reperfusion (I/R) injury is common in the development of ophthalmic diseases and potentially causes blindness. In present study, the aim is to investigate the possible protective effects of puerarin on retinal I/R. MAIN METHODS: Retinal I/R injury was conducted on the left eyes of male Sprague Dawley rats, which were subsequently received treatment with puerarin. After administration, retinal I/R-induced apoptosis, oxidative stress and inflammatory responses were detected. Meanwhile, we purified retinal ganglion cells (RGCs) from 7-day-old rats. After subjected RGCs to oxygen and glucose deprivation/reoxygenation (OGD/R), apoptosis and TLR4/NLRP3 inflammasome activation in RGCs were detected. KEY FINDINGS: Puerarin prominently suppressed apoptosis, alleviated oxidative stress and suppressed TLR4/NLRP3 inflammasome activation in rats with retinal I/R injury. Consistent with our in vivo study, we found puerarin ameliorated retinal I/R injury through suppressing apoptosis and TLR4/NLRP3 inflammasome activation in RGCs. SIGNIFICANCE: Our findings reveal that puerarin plays a protective role against retinal I/R injury by alleviating RGC damage, and is beneficial for the treatment of I/R injury-caused ophthalmic diseases.

Plastic-based acoustofluidic devices for high-throughput, biocompatible platelet separation.

Platelet separation is a crucial step for both blood donation and treatment of essential thrombocytosis. Here we present an acoustofluidic device that is capable of performing high-throughput, biocompatible platelet separation using sound waves. The device is entirely made of plastic material, which renders the device disposable and more suitable for clinical use. We used this device to process undiluted human whole blood, and we demonstrate a sample throughput of 20 mL min-1, a platelet recovery rate of 87.3%, and a red/white blood cell removal rate of 88.9%. We preserved better platelet function and integrity for isolated platelets than those which are isolated using established methods. Our device features advantages such as rapid fabrication, high throughput, and biocompatibility, so it is a promising alternative to existing platelet separation approaches.

Rho Kinase Type 1 (ROCK1) Promotes Lipopolysaccharide-induced Inflammation in Corneal Epithelial Cells by Activating Toll-Like Receptor 4 (TLR4)-Mediated Signaling.

BACKGROUND Rho kinases (ROCKs) are the typical downstream effectors of RhoA, which can regulate corneal epithelial wound healing. In this study, the role of ROCK1 in lipopolysaccharide (LPS)-induced cornea inflammation was investigated. MATERIAL AND METHODS The expression of ROCK1 in human corneal epithelial cells (HCECs) was bilaterally modulated with ROCK1 expression vector and ROCK1 inhibitor Y-27632. The effects of ROCK1 modulation on the inflammatory response, cell viability, cell apoptosis, and cell cycle distribution were detected by ELISA assay, MTT assay, and flow cytometry, respectively. The pathways involved in the effect of ROCK1 in HCECs was preliminarily explained by detecting changes of TLR4-mediated NF-kB and ERK signaling using western blotting and electrophoretic mobility shift assays. RESULTS Overexpression of ROCK1 promoted LPS-induced production of IL-6, IL-8, IL-1ß, and TNF-α, and the apoptotic process in HCECs. Augmented inflammation and apoptosis were associated with stronger activation of TLR4-mediated signal transduction; the phosphorylation of IkBa, JNK, ERK1/2, and p38, and nuclear translocation of NF-κB p65 induced by LPS were further increased by overexpression of ROCK1. Inhibition of ROCK1 function by Y-27632 blocked the effect of LPS on HCECs; both LPS-induced inflammation and apoptosis was alleviated by Y-27632, which was associated with suppression of TLR4-mediated NF-κB and ERK signaling. CONCLUSIONS LPS-induced inflammation and apoptosis in HCECs depended on the function of ROCK1, inhibition of which would attenuate impairments on cornea cells due to LPS.

Hybrid Dielectric-loaded Nanoridge Plasmonic Waveguide for Low-Loss Light Transmission at the Subwavelength Scale.

The emerging development of the hybrid plasmonic waveguide has recently received significant attention owing to its remarkable capability of enabling subwavelength field confinement and great transmission distance. Here we report a guiding approach that integrates hybrid plasmon polariton with dielectric-loaded plasmonic waveguiding. By introducing a deep-subwavelength dielectric ridge between a dielectric slab and a metallic substrate, a hybrid dielectric-loaded nanoridge plasmonic waveguide is formed. The waveguide features lower propagation loss than its conventional hybrid waveguiding counterpart, while maintaining strong optical confinement at telecommunication wavelengths. Through systematic structural parameter tuning, we realize an efficient balance between confinement and attenuation of the fundamental hybrid mode, and we demonstrate the tolerance of its properties despite fabrication imperfections. Furthermore, we show that the waveguide concept can be extended to other metal/dielectric composites as well, including metal-insulator-metal and insulator-metal-insulator configurations. Our hybrid dielectric-loaded nanoridge plasmonic platform may serve as a fundamental building block for various functional photonic components and be used in applications such as sensing, nanofocusing, and nanolasing.

Acoustofluidic waveguides for localized control of acoustic wavefront in microfluidics.

The precise manipulation of acoustic fields in microfluidics is of critical importance for the realization of many biomedical applications. Despite the tremendous efforts devoted to the field of acoustofluidics during recent years, dexterous control, with an arbitrary and complex acoustic wavefront, in a prescribed, microscale region is still out of reach. Here, we introduce the concept of acoustofluidic waveguide, a three-dimensional compact configuration that is capable of locally guiding acoustic waves into a fluidic environment. Through comprehensive numerical simulations, we revealed the possibility of forming complex field patterns with defined pressure nodes within a highly localized, pre-determined region inside the microfluidic chamber. We also demonstrated the tunability of the acoustic field profile through controlling the size and shape of the waveguide geometry, as well as the operational frequency of the acoustic wave. The feasibility of the waveguide concept was experimentally verified via microparticle trapping and patterning. Our acoustofluidic waveguiding structures can be readily integrated with other microfluidic configurations and can be further designed into more complex types of passive acoustofluidic devices. The waveguide platform provides a promising alternative to current acoustic manipulation techniques and is useful in many applications such as single-cell analysis, point-of-care diagnostics, and studies of cell-cell interactions.

Genetic polymorphisms of HSP70 in age-related cataract.

Polymorphisms have been identified in several HSP70 genes, which may affect HSP70 repair efficiency. We investigated the association of the polymorphisms in HSPA1A, HSPA1B, and HSPA1L genes in the HSPs repair pathway with the risk of cataract in a Chinese population. The study included 415 cataract patients and 386 controls. Genotyping was done by the polymerase chain reaction-restriction fragment length polymorphism method. HSPA1B 1267 A/A genotype seems to have a protective role against cataract (p = 0.014, odds ratio (OR) = 0.664, 95 % confidence intervals (CI) = 0.480-0.919), and the G allele (p = 0.057, OR = 1.216, 95 % CI = 0.999-1.479) does not seem to have a deleterious role in the development of cataract. Haplotypes with frequencies of GAT were significantly different than those of controls (p = 0.005). In HSPA1A G190C and HSPA1L T2437C polymorphisms, there were no significant differences in frequencies of the variant homozygous in patients compared to controls. We conclude that the A/A genotype of HSPA1B A1267G polymorphism seem to have a protective role against age-related cataract.