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NiO nanoparticles with average particle size of 25 nm were successfully prepared by anodic arc plasma method. The composition, morphology, crystal microstructure, specific surface area, infrared spectra, and particle size distribution of product were analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectrum, and Brunauer-Emmett-Teller (BET)N2adsorption. The experiment results show that the NiO nanoparticles are bcc structure with spherical shape and well dispersed, the particle size distribution ranging from 15 to 45 nm with the average particle size is about 25 nm, and the specific surface area is 33 m2/g. The infrared absorption band of NiO nanoparticles shows blue shifts compared with that of bulk NiO.

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In the protecting inert gas, silver nanoparticles were successfully prepared by confined arc plasma method. The particle size, microstructure, and morphology of the particles by this process were characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). TheN2absorption-desorption isotherms of the samples were measured by using the static volumetric absorption analyzer, the pore structure of the sample was calculated by Barrett-Joyner-Halenda (BJH) academic model, and the specific surface area was calculated from Brunauer-Emmett-Teller (BET) adsorption equation. The experiment results indicate that the crystal structure of the samples is face-centered cubic (FCC) structure the same as the bulk materials, the particle size distribution ranging from 5 to 65 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 23.81 m2/g, pore volumes are 0.09 cm3/g, and average pore diameter is 18.7 nm.

Photodynamic therapy (PDT) holds great promise as a noninvasive and selective cancer therapeutic treatment in preclinical research and clinical practice; however, it has limited efficacy in the ablation of deep-seated tumor because of hypoxia-associated circumstance and poor penetration of photosensitizers to cancer cells away from the blood vessels. To tackle the obstacles, we propose a therapeutic strategy that synergizes upconversion nanophotosensitizers (UNPSs) with hyperbaric oxygen (HBO) to remodel the extracellular matrix for enhanced photodynamic cancer therapy. The UNPSs are designed to have an Nd-sensitized sandwiched structure, wherein the upconversion core serves as light transducers to transfer energy to the neighboring photosensitizers to produce reactive oxygen species (ROS). With HBO, photodynamic process can generate abundant ROS in the intrinsically hypoxic tumor. It is revealed for the first time that HBO-assisted PDT decomposes collagen in the extracellular matrix of tumor and thus facilitates the diffusion of oxygen and penetration of UNPSs into the deeper area of tumor. Such a synergic effect eventually results in a significantly enhanced therapeutic efficacy at a low laser power density as compared with that using UNPSs alone. In view of its good biosafety, the HBO-assisted and UNPSs-mediated PDT provides new possibilities for treatment of solid tumors.

Pale, soft, exudative (PSE), normal, and dark, firm, dry (DFD) pork was held 7 days at 4°C under light or dark then color was evaluated instrumentally and visually. Change in reflectance (R630-R580) was used to estimate color changes due to oxymyoglobin. PSE pork was lighter (high L*) than normal and DFD pork, but did not change over time. An increase in a* and R630-R580 occurred the first day for normal and DFD, but not for PSE samples. A subsequent increase in hue angle and decrease in R630-R580 (loss of redness) occurred in PSE and normal, but not in DFD samples. Changes in hue angle and R630-R580 were more rapid in PSE than in normal samples. Light exposure accelerated all changes except L*. Visual redness inversely correlated with L* value.

A range of meat redness was created by mixing fresh, chilled ground chicken breast and ground beef in predetermined ratios. Samples were scored for visual redness under halogen (incandescent) and cool white fluorescent lighting. Instrumental color characteristics (L*, a*, b*, hue angle, chroma; illuminants A and F) and red color contributed by oxymyoglobin (percentage reflectance at 630 nm versus 580 nm) were determined. Correlation coefficients were determined between visual and instrumental evaluations. The a*, b*, and ΔR (630–580) were highly correlated to visual redness (halogen light: r = 0.99, ‐0.99, and 0.96, respectively; cool white fluorescent light: 0.98, ‐0.98, and 0.96, respectively). Regression analysis was conducted to develop equations to predict visual redness using instrumental color measures. In the 20% to 85% beef range, the regression curves were principally linear although the overall relationships (0–100% beef range) were cubic. Among the instrumental color parameters, a*, hue angle, and ΔR (630–580) could be used to predict visual redness for this model system.

Fresh pale, soft, exudative (PSE), dark, firm, dry (DFD), and normal pork were stored under light or dark conditions at 4ЊC for 7 days. Sample pH, metmyoglobin reductase activity, oxygen consumption rate, and relative surface metmyoglobin and oxymyoglobin contents were determined. DFD pork had the highest metmyoglobin reductase activity and oxygen consumption rate. Enzyme activity of PSE was lower than that of normal pork, but no difference existed in oxygen consumption rate between PSE and normal samples. Metmyoglobin reductase activity dropped slowly during meat storage; oxygen consumption rate sharply decreased during the first day of storage. Both metmyoglobin reductase activity and oxygen consumption rate declined more rapidly in the light. Results can help develop guidelines for display and packaging of pork.