Systematic study of ionic conduction in silver iodide/mesoporous alumina composites 2: effects of silver bromide doping.

In our preceding paper (Y. Fukui et al., Phys. Chem. Chem. Phys., 2023, 25, 25594-25602), we reported a systematic study of the Ag+-ion conducting behaviour of silver iodide (AgI)-loaded mesoporous aluminas (MPAs) with different pore diameters and AgI-loading ratios. By optimising the control parameters, the Ag+-ion conductivity has reached 7.2 × 10-4 S cm-1 at room temperature, which is more than three orders of magnitude higher than that of bulk AgI. In the present study, the effect of silver bromide (AgBr)-doping in the AgI/MPA composites on Ag+-ion conductivity is systematically investigated for the first time, using variable-temperature powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. The AgBr-doped AgI/MPA composites, AgI-AgBr/MPA, formed a homogeneous ß/γ-AgI-structured solid solution (ß/γ-AgIss) for the composites with AgBr ≤ 10 mol%, above which the composites underwent a phase separation into ß/γ-AgIss and face-centred cubic AgBr solid solutions (AgBrss). The onset temperature of the exothermic peaks attributed to the transition from α-AgI-structured solid-solution phase to ß/γ-AgIss or AgBrss decreased with increasing the AgBr-doping ratio. The room-temperature ionic conductivity of the AgI-AgBr/MPA composites exhibited a volcano-type dependence on the AgBr-doping ratio with the highest value (1.6 × 10-3 S cm-1) when the AgBr content was 10 mol%. This value is more than twice as high as that of the highest conducting AgI/MPA found in our previous study.

Systematic study of ionic conduction in silver iodide/mesoporous alumina composites 1: effects of pore size and filling level.

A systematic study of Ag+-ion conducting behavior in Ag+-loaded porous materials was conducted over the entire sub-10 nm region for the first time. The effects of the pore diameter of mesoporous aluminas (MPAs) and the amount of silver iodide (AgI) loaded into MPAs were investigated using N2 gas adsorption/desorption, powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. Confinement of AgI in the mesoporous space lowers the phase transition temperature between the ß/γ- and α-phases relative to that of bulk AgI. The AgI-loading into the MPAs with smaller pores led to a more significant decrease in the transition temperature, possibly because the smaller AgI nanoparticles in the pores must have a higher surface energy to stabilize the high-temperature phase. The room-temperature ionic conductivity exhibits a volcano-type dependence on the pore diameter with the highest value when AgI was loaded into MPA with a pore diameter of 7.1 nm (7.2 × 10-4 S cm-1 at room temperature). Concerning the 7.1 nm-MPA, the room-temperature ionic conductivity was the highest for the nearly fully occupied composite, which is more than three orders of magnitude higher than that of the bulk AgI. The present study reveals that the Ag+-ion conductivity in AgI/MPA composites can be controlled by optimizing the pore diameter of MPA and the AgI-loading ratio.

Hemolysis Precedes Urine Color Change in Patients Undergoing Open-Heart Surgery on Cardiopulmonary Bypass.

PURPOSE: Red-colored urine often occurs in patients in the perioperative period who undergo cardiac surgery using cardiopulmonary bypass (CPB). This urine color change has been utilized for approximating hemolysis during CPB without a proven relationship for ongoing hemolysis. This case series study aimed to examine the relationship between plasma free hemoglobin (Hb) levels and quantified measures of urine color. METHODS: Ten patients were enrolled in this study. Blood and urine were collected for analyses for the following time points: before surgery, two hours after the initiation of CPB, every 30 min during CPB thereafter, and 0, 2, 4, 12, and 24 hours after the completion of CPB. We measured free Hb in plasma and urine using the azide-methemoglobin method. Photographs of urine were obtained, and the luminance of the three basic colors (red/green/blue) was analyzed by quantitative luminance contrast analysis to find a correlation for hemolysis. RESULTS: Median levels of plasma free Hb were 0.015 (0.010-0.080, n = 10) g/dL at baseline. During the CPB, increases in plasma free Hb levels were measured: median plasma free Hb levels were increased to 0.100 g/dL (0.020-0.240, p = 0.039, vs. baseline, n = 9) at two hours into CPB, median and range, respectively. In contrast, increases in urinary free Hb levels and/or urine color changes were measured only after cessation of CPB in nine patients. CONCLUSION: Urine color change or elevation of urinary free Hb levels followed the elevation of plasma free Hb levels with considerable delay.

Application of Copper Iodide Nanoparticle-Doped Film and Fabric To Inactivate SARS-CoV-2 via the Virucidal Activity of Cuprous Ions (Cu+).

As a result of the novel coronavirus disease 2019 pandemic, strengthening control measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become an urgent global issue. In addition to antiviral therapy and vaccination strategies, applying available virucidal substances for SARS-CoV-2 inactivation is also a target of research to prevent the spread of infection. Here, we evaluated the SARS-CoV-2 inactivation activity of a copper iodide (CuI) nanoparticle dispersion, which provides Cu+ ions having high virucidal activity, and its mode of actions. In addition, the utility of CuI-doped film and fabric for SARS-CoV-2 inactivation was evaluated. The CuI dispersion exhibited time-dependent rapid virucidal activity. Analyses of the modes of action of CuI performed by Western blotting and real-time reverse transcription-PCR targeting viral proteins and the genome revealed that CuI treatment induced the destruction of these viral components. In this setting, the indirect action of CuI-derived reactive oxygen species contributed to the destruction of viral protein. Moreover, the CuI-doped film and fabric demonstrated rapid inactivation of the SARS-CoV-2 solution in which the viral titer was high. These findings indicated the utility of the CuI-doped film and fabric as anti-SARS-CoV-2 materials for the protection of high-touch environmental surfaces and surgical masks/protective clothes. Throughout this study, we demonstrated the effectiveness of CuI nanoparticles for inactivating SARS-CoV-2 and revealed a part of its virucidal mechanism of action. IMPORTANCE The COVID-19 pandemic has caused an unprecedented number of infections and deaths. As the spread of the disease is rapid and the risk of infection is severe, hand and environmental hygiene may contribute to suppressing contact transmission of SARS-CoV-2. Here, we evaluated the SARS-CoV-2 inactivation activity of CuI nanoparticles, which provide the Cu+ ion as an antiviral agent, and we provided advanced findings of the virucidal mechanisms of action of Cu+. Our results showed that the CuI dispersion, as well as CuI-doped film and fabric, rapidly inactivated SARS-CoV-2 with a high viral titer. We also demonstrated the CuI's virucidal mechanisms of action, specifically the destruction of viral proteins and the genome by CuI treatment. Protein destruction largely depended on CuI-derived reactive oxygen species. This study provides novel information about the utility and mechanisms of action of promising virucidal material against SARS-CoV-2.

Diurnal changes in oral malodour among dental-office workers.

PURPOSE: Dentistry is a major resource for the treatment of halitosis, therefore dental professionals must also pay attention to their own oral malodour for professional courtesy. However, oral malodour among dental professionals has not yet been investigated. In this study, the diurnal changes in oral malodour in dental-office workers were determined, and preventative measures were assessed. METHODS: Diurnal changes in the levels of volatile sulphur compounds (VSCs), which are the main cause of oral malodour, in mouth air were determined with a gas chromatograph specially designed for such analysis and the effects of several preventive measures were evaluated. RESULTS: High concentrations of VSCs in mouth air persisted during the morning and decreased after lunch. Tongue-cleaning followed by tooth brushing decreased VSCs dramatically. Further measures such as eating breakfast, drinking tea or using zinc mouthwash significantly decreased VSCs, but the effects were limited in dental hygienists who suffered from persistent oral malodour, especially in the afternoon. CONCLUSION: Eating breakfast, cleaning the tongue followed by brushing the teeth and zinc chloride mouthwash were very effective in preventing oral malodour in dental-office workers; however, the effectiveness of these preventive measures was limited in dental hygienists.

Inhibitory effects of extracellular matrix modulator(s) on lipopolysaccharide (LPS)- and acidosis-damaged glia containing cerebellar granule cell cultures.

The inhibitory effects of a novel chondroitin sulfate compound on lipopolysaccharide (LPS)- and acidosis-induced neuronal dysfunctions were examined. Cell viabilities in cultured neurons and/or astrocyte-rich cerebellar granule cells were measured by the calcein-AM method. Ten and 20 microg, as a final dosage, of LPS damaged less than 20% cells during a-2 h incubation. More than 5000 ng/ml of chondroitin sulphate-dipalmitoylphosphatidylethanolamine (CS-PE), but not chondroitin sulfate (CS) treatment, significantly inhibited such damage. Twenty microg of LPS damaged more than 40% cells during 24 h incubation, and these cell damages were significantly inhibited by less than 1000 ng/ml of CS-PE. Moreover, treatments with between 5 and 500 ng/ml CS-PE, but not CS, significantly reduced the number of acidosis-damaged cells in a dose-dependent manner. The current results indicate that modulator(s) of ECM and its derivative containing covalently linked dipalmitoylphosphatidylethanolamine show neuroprotective effects under conditions of brain inflammation.