Search

The transformation of aerosol proteinaceous matter (PrM) has potentially adverse environmental and health effects. The origins and atmospheric processes of PrM have obtained an increasing interest, but there are still large uncertainties. Although aerosol liquid water (ALW) has been found to be vital in numerous atmospheric processes, its impact on atmospheric degradation of PrM remains poorly understood. ALW, proteins, and low molecular weight PrM (LMW PrM, <10 kDa) were investigated in fine aerosols (PM2.5) collected in urban and suburban Nanchang (Eastern China) over a 1‐year period. The average concentrations of proteins and LMW PrM in the urban center were higher than those in the suburban area. Urban PrM tended to increase from cool season to warm season, which was opposite to the case of suburban PrM. These differences could be attributed to varied sources and atmospheric processes of PrM. Increase in ALW was prominent from the suburban site to the urban site, which was attributable to increased anthropogenic nitrate and sulfate. LMW PrM can be degraded from higher molecular weight PrM by ozone. Furthermore, correlation analysis between LMW PrM and ozone and ALW suggested that the enhanced ALW in the urban center facilitated the ozone‐induced LMW PrM release. The ALW‐related protein degradation was further supported by ozone exposure experiments with bovine serum albumin and PM2.5 samples under dry condition. Our findings suggest that ALW is a crucial promoter during PrM degradation by ozone, providing new insights into atmospheric transformation of proteins. Plain Language Summary: Recent observation‐based studies on interactions between aerosol proteins and ozone have suggested that free amino acids in fine aerosols (PM2.5) can be degraded from proteins under the influence of ozone. Here, proteins, low molecular weight (LMW) proteinaceous matter (PrM), and aerosol liquid water (ALW) were investigated in PM2.5 collected in urban and suburban Nanchang (Eastern China) over a 1‐year period. Interestingly, we found that alone ozone cannot explain the production of LMW PrM in this study. Specifically, LMW PrM was found to be largely degraded from higher molecular weight PrM by ozone in the urban center (high ALW), whereas this degradation process was insignificant in the suburban area (low ALW). Correlation analysis between LMW PrM and ozone and ALW suggested that increased ALW in the urban center may promote the production of LMW PrM from ozone‐related aqueous‐phase reactions. This consideration was also supported by ozone exposure experiments with bovine serum albumin and PM2.5 samples under dry condition. The overall results suggest that ALW plays an important role in PrM degradation by ozone. Therefore, this study provides new insights into the fate of proteins in the atmosphere. Key Points: The significant increase in aerosol liquid water (ALW) from the urban center to the suburban area is attributable to increased anthropogenic nitrates and sulfatesAtmospheric degradation of high molecular weight proteinaceous matter (PrM) by ozone is an important secondary source of low molecular weight (LMW) PrM, especially in the urban areaThe increased ALW in the urban area promotes the ozone‐related LMW PrM release [ABSTRACT FROM AUTHOR]

Monitoring the dynamic pH changes in vivo remains very essential to comprehend the function of pH in various physiological processes. In this study, we report a high-performance electrochemical pH microneedle based on an acupuncture needle (AN) for real-time monitoring of pH changes in a rat brain. The pH microneedle was prepared by a layer-to-layer assembly of molybdenum disulfide (MoS2) nanosheets and polyaniline (PAN), with an attempt to achieve a highly sensitive detection of hydrogen ions (H+). The as-prepared PAN/MoS2/AN exhibited a high Nernstian response of −51.2 mV per pH over a wide pH range from 3.0 to 9.0, and excellent selectivity toward pH against other potential interfering species in the brain. Moreover, the corresponding open circuit potential rapidly increased and decreased when Na2CO3 or NaH2PO4 was injected into the rat brain, respectively, demonstrating that the PAN/MoS2/AN has an excellent response toward pH changes in vivo. This work provides a new potentiometric method for real-time monitoring of dynamic pH changes in vivo with high reliability and stability. [ABSTRACT FROM AUTHOR]

Time-efficient synthetic methods of porous organic polymers are searched in order to extend the applications of these materials. In this work, we show a robust and time-efficient synthetic method of azo-linked porous organic polymers named Azo-POPs based on a NaBH4-mediated reductive coupling polymerization on well-known polynitro monomers. Azo-POPs were found to have a high Brunauer–Emmett–Teller (BET) surface area and potential for aniline adsorption. Interestingly, Azo-POP-1 showed adsorption capacity towards aniline as high as 1059.68 mg g−1 at 293 K, which surpassed that of adsorbent materials reported in the literature. [ABSTRACT FROM AUTHOR]

This work describes the adaptive use of a conventional stainless steel acupuncture needle as the electrode substrate for construction of a molybdenum disulfide (MoS2) and platinum nanoparticles (PtNPs) layer-modified microneedle sensor for real-time monitoring of hydrogen peroxide (H2O2) release from living cells. To construct the nanocomposite-functionalized microneedle, the needle surface was first coated with a gold film by ion sputtering to enhance the conductivity. Subsequently, an electrochemical deposition method was successfully employed to deposit MoS2 nanosheet and Pt nanoparticles on the needle tip as the sensing interface. Electrochemical study demonstrated that the MoS2/PtNPs nanocomposite-modified needle exhibited excellent catalytic performance and low over-potential toward the reduction of H2O2. Not only did the microneedle achieve a wide linear range from 1 to 100 μmol L−1 with a limit of detection down to 0.686 μmol L−1, but it also realized the highly specific detection of H2O2. Owing to these remarkable analytical advantages, the prepared microneedle was applied to determine H2O2 release from living cells with satisfactory results. The MoS2/PtNPs nanocomposite-functionalized microneedle sensor is simple and affordable, and can serve as a promising electrochemical nonenzymatic sensing platform. Moreover, this superfine needle sensor shows great potential for real-time monitoring of reactive oxygen species in vivo with minimal damage. [ABSTRACT FROM AUTHOR]

Aim: To evaluate macular microvasculature changes in eyes after pars plana vitrectomy (PPV) and intraocular silicone oil (SO) tamponade for macula-off rhegmatogenous retinal detachment (RRD) using optical coherence tomography angiography (OCTA)., Methods: Totally 19 eyes (19 patients) with macula-off RRD who underwent PPV and intraocular SO tamponade were retrospectively reviewed. The parafoveal superficial capillary plexus (SCP) vessel density (VD), deep capillary plexus (DCP) VD, choriocapillaris plexus (CCP) VD, and foveal macular thickness were evaluated using OCTA throughout 16wk postoperatively. The values of healthy fellow eyes were used as control., Results: The parafoveal SCP, DCP, and CCP VDs were significant increased over time in RRD eyes during the 12wk postoperatively, then decreased at 16wk postoperatively (all P <0.01). The ratios of RRD eyes and fellow healthy eyes (r/f ratios) of the SCP and DCP VDs were lower than those of the CCP VD postoperatively (all P <0.05). There were not significant differences in the r/f ratios between SCP and DCP VDs postoperatively (all P >0.05)., Conclusion: The parafoveal SCP, DCP, and CCP VDs gradually recover over time after PPV surgery with SO tamponade. Long-time SO tamponade might decrease postoperative macular VDs. Compared to parafoveal CCP VD, the parafoveal SCP and DCP VDs were more vulnerable in RRD eyes postoperatively., (International Journal of Ophthalmology Press.)

Monitoring the dynamic pH changes in vivo remains very essential to comprehend the function of pH in various physiological processes. In this study, we report a high-performance electrochemical pH microneedle based on an acupuncture needle (AN) for real-time monitoring of pH changes in a rat brain. The pH microneedle was prepared by a layer-to-layer assembly of molybdenum disulfide (MoS2) nanosheets and polyaniline (PAN), with an attempt to achieve a highly sensitive detection of hydrogen ions (H+). The as-prepared PAN/MoS2/AN exhibited a high Nernstian response of -51.2 mV per pH over a wide pH range from 3.0 to 9.0, and excellent selectivity toward pH against other potential interfering species in the brain. Moreover, the corresponding open circuit potential rapidly increased and decreased when Na2CO3 or NaH2PO4 was injected into the rat brain, respectively, demonstrating that the PAN/MoS2/AN has an excellent response toward pH changes in vivo. This work provides a new potentiometric method for real-time monitoring of dynamic pH changes in vivo with high reliability and stability.

This work describes the adaptive use of a conventional stainless steel acupuncture needle as the electrode substrate for construction of a molybdenum disulfide (MoS 2 ) and platinum nanoparticles (PtNPs) layer-modified microneedle sensor for real-time monitoring of hydrogen peroxide (H 2 O 2 ) release from living cells. To construct the nanocomposite-functionalized microneedle, the needle surface was first coated with a gold film by ion sputtering to enhance the conductivity. Subsequently, an electrochemical deposition method was successfully employed to deposit MoS 2 nanosheet and Pt nanoparticles on the needle tip as the sensing interface. Electrochemical study demonstrated that the MoS 2 /PtNPs nanocomposite-modified needle exhibited excellent catalytic performance and low over-potential toward the reduction of H 2 O 2 . Not only did the microneedle achieve a wide linear range from 1 to 100 μmol L -1 with a limit of detection down to 0.686 μmol L -1 , but it also realized the highly specific detection of H 2 O 2 . Owing to these remarkable analytical advantages, the prepared microneedle was applied to determine H 2 O 2 release from living cells with satisfactory results. The MoS 2 /PtNPs nanocomposite-functionalized microneedle sensor is simple and affordable, and can serve as a promising electrochemical nonenzymatic sensing platform. Moreover, this superfine needle sensor shows great potential for real-time monitoring of reactive oxygen species in vivo with minimal damage.