NiO/NiWO₄ Composite Yolk–Shell Spheres with Nanoscale NiO Outer Layer for Ultrasensitive and Selective Detection of Subppm-level <i>p</i>‑Xylene

NiO/NiWO₄ composite yolk–shell spheres with a nanoscale NiO outer layer were prepared using one-pot ultrasonic spray pyrolysis and their gas sensing characteristics were studied. The NiO/NiWO₄ yolk–shell spheres exhibited an extremely high response to 5 ppm <i>p</i>-xylene (ratio of resistance to gas and air = 343.5) and negligible cross-responses to 5 ppm ethanol, ammonia, carbon monoxide, hydrogen, and benzene, whereas pure NiO yolk–shell spheres showed very low responses and selectivity to all the analyte gases. The detection limit for <i>p</i>-xylene was as low as 22.7 ppb. This ultrasensitive and selective detection of <i>p</i>-xylene is attributed to a synergistic catalytic effect between NiO and NiWO₄, high gas accessibility with large specific surface area, and increased chemiresistive variation due to the formation of a heterojunction. The NiO/NiWO₄ yolk–shell spheres with a thin NiO outer layer can be used to detect subppm-level <i>p</i>-xylene in a highly sensitive and selective manner for monitoring indoor air pollution

Electrically Controlled Delivery of Cargo into Single Human Neural Stem Cell

Nanoprobe-based techniques have emerged as an efficient tool for the manipulation and analysis of single cells. Here, we report a powerful whole-electrical single-cell manipulation tool that enables rapid and controllable delivery of cargo into single neural stem cells with precision monitoring of the cell penetration process using a conductive nanoprobe. The highly electrically sensitive nanoprobes that were fabricated and the indium tin oxide electrode-integrated cell chip were found to be very effective for monitoring the cell penetration process via current changes that appear as spike-like negative currents. Moreover, the assembly of cargoes onto the nanoprobes was controllable and could reach its maximum load in a very short period of time (<10 min) based on the same electrical system that was used for monitoring cell penetration and without the need for any complex chemical linkers or mediators. Even more remarkably, the cargo assembled on the surface of the nanoprobe was successfully released in a very short period of time (<10 s), regardless of the surrounding intracellular or extracellular environments. The monitoring of cell penetration, assembly of quantum dots (QDs), and release of QDs into the intracellular environment were all accomplished using our whole-electrical system that combined a conductive nanoprobe with cell chip technology. This is a novel technology, which can eliminate complex and time-consuming steps owing to chemical modifications, as well as reduce the time needed for the delivery of cargo into the cell cytosol/nucleus during cell penetration, which is very important for reducing cell damage

Enhanced Ethanol Sensing Characteristics of In₂O₃‑Decorated NiO Hollow Nanostructures via Modulation of Hole Accumulation Layers

In this work, we report a dramatic enhancement in ethanol sensing characteristics of NiO hollow nanostructures via decoration with In₂O₃ nanoclusters. The pure NiO and 1.64–4.41 atom % In-doped NiO and In₂O₃-decorated NiO hollow spheres were prepared by ultrasonic spray pyrolysis, and their gas sensing characteristics were investigated. The response (the ratio between the resistance in gas and air) of the In₂O₃-decorated NiO hollow spheres to 5 ppm ethanol (C₂H₅OH) was 9.76 at 350 °C, which represents a significant improvement over the In-doped NiO and pure NiO hollow spheres (3.37 and 2.18, respectively). Furthermore, the 90% recovery time was drastically reduced from 1880 to 23 s, and a selective detection of ethanol with negligible cross-response to other gases was achieved. The enhanced gas response and fast recovery kinetics were explained in relation to the thinning of the near-surface hole accumulation layer of p-type NiO underneath n-type In₂O₃, the change of charge carrier concentration, and the variation of oxygen adsorption

Graphene Size-Dependent Multifunctional Properties of Unidirectional Graphene Aerogel/Epoxy Nanocomposites

Unidirectional graphene aerogels (UGAs) with tunable densities, degrees of alignment, and electrical conductivities are prepared by varying the average size of precursor graphene oxide (GO) sheets between 1.1 and 1596 μm². UGAs prepared using ultralarge GO (UL-UGA) outperform those made from small GO in these properties. The UL-UGA/epoxy composites prepared by infiltrating liquid epoxy resin into the porous UGA structure exhibit an excellent electrical conductivity of 0.135 S/cm, along with an ultralow percolation threshold of 0.0066 vol %, which is one of the lowest values ever reported for all graphene-based composites. Owing to their three-dimensional interconnected network, a high degree of alignment, and effective reduction, UL-UGAs effectively enhance the fracture toughness of epoxy by 69% at 0.11 vol % graphene content through unique toughening mechanisms, such as crack pinning, crack deflection, interfacial debonding, and graphene rupture. These aerogels and composites can be mass-produced thanks to the facile, scalable, and cost-efficient fabrication process, which will find various multifunctional applications

Metal–Organic Framework-Derived Hollow Hierarchical Co₃O₄ Nanocages with Tunable Size and Morphology: Ultrasensitive and Highly Selective Detection of Methylbenzenes

Nearly monodisperse hollow hierarchical Co₃O₄ nanocages of four different sizes (∼0.3, 1.0, 2.0, and 4.0 μm) consisting of nanosheets were prepared by controlled precipitation of zeolitic imidazolate framework-67 (ZIF-67) rhombic dodecahedra, followed by solvothermal synthesis of Co₃O₄ nanocages using ZIF-67 self-sacrificial templates, and subsequent heat treatment for the development of high-performance methylbenzene sensors. The sensor based on hollow hierarchical Co₃O₄ nanocages with the size of ∼1.0 μm exhibited not only ultrahigh responses (resistance ratios) to 5 ppm <i>p</i>-xylene (78.6) and toluene (43.8) but also a remarkably high selectivity to methylbenzene over the interference of ubiquitous ethanol at 225 °C. The unprecedented and high response and selectivity to methylbenzenes are attributed to the highly gas-accessible hollow hierarchical morphology with thin shells, abundant mesopores, and high surface area per unit volume as well as the high catalytic activity of Co₃O₄. Moreover, the size, shell thickness, mesopores, and hollow/hierarchical morphology of the nanocages, the key parameters determining the gas response and selectivity, could be well-controlled by tuning the precipitation of ZIF-67 rhombic dodecahedra and solvothermal reaction. This method can pave a new pathway for the design of high-performance methylbenzene sensors for monitoring the quality of indoor air

Additional file 1: of Efficacy and safety of indacaterol/glycopyrronium fixed-dose combination in mild-to-moderate COPD patients symptomatic on tiotropium in Korea: study protocol for a randomized controlled trial

List of participating centers in Korea. (DOC 63 kb

No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers - Fig 6

<p>(a) Photograph shows the whitish area of the gall bladder suggesting thermal injury (arrow). (b) (c) Corresponding gall bladder specimen and adjacent liver parenchyma with hematoxylin and eosin staining (H&E) show thermal injury to the mucosa. Mucosal and submucosal damage are evident. Lymphatic dilatation of subserosa is noted in (b) (circle) (x12.5). The mucosal epithelium is replaced by dense fibrosis in (c) (arrow) (x100). (d) Photograph shows the H&E stained gall bladder specimen without thermal injury (x100).</p

Data_Sheet_1_Risk of newly diagnosed interstitial lung disease after COVID-19 and impact of vaccination: a nationwide population-based cohort study.docx

ObjectivesPrevious studies suggested that coronavirus disease 2019 (COVID-19) could lead to pulmonary fibrosis, but the incidence of newly diagnosed interstitial lung disease (ILD) after COVID-19 is unclear. We aimed to determine whether COVID-19 increases the risk of newly diagnosed ILD and whether vaccination against COVID-19 can reduce this risk.MethodsThis retrospective cohort study used data from the Korean National Health Insurance claim-based database. Two study groups and propensity score (PS)-matched control groups were constructed: Study 1: participants diagnosed with COVID-19 (COVID-19 cohort) and their PS-matched controls; Study 2: COVID-19 vaccinated participants (vaccination cohort) and their PS-matched controls.ResultsIn Study 1, during a median 6 months of follow-up, 0.50% of the COVID-19 cohort (300/60,518) and 0.04% of controls (27/60,518) developed newly diagnosed ILD, with an incidence of 9.76 and 0.88 per 1,000 person-years, respectively. The COVID-19 cohort had a higher risk of ILD [adjusted hazard ratio (aHR), 11.01; 95% confidence interval (CI), 7.42–16.32] than controls. In Study 2, the vaccination cohort had a lower risk of newly diagnosed ILD than controls (aHR, 0.44; 95% CI, 0.34–0.57).ConclusionUsing nationwide data, we demonstrated that COVID-19 was associated with a higher incidence rate of newly diagnosed ILD, but that this risk could be mitigated by COVID-19 vaccination.</p

Photograph of a prototype RFA generator and a clustered separable Octopus® electrode.

<p>Photograph of a prototype RFA generator and a clustered separable Octopus® electrode.</p

Measured values of technical parameters according to the power application modes.

<p>Measured values of technical parameters according to the power application modes.</p