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Earth system models (ESMs) participating in the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) simulate various components of fine particulate matter (PM2.5) as major climate forcers. Yet the model performance for PM2.5 components remains little evaluated due in part to a lack of observational data. Here, we evaluate near-surface concentrations of PM2.5 and its five main components over China as simulated by 14 CMIP6 models, including organic carbon (OC; available in 14 models), black carbon (BC; 14 models), sulfate (14 models), nitrate (4 models), and ammonium (5 models). For this purpose, we collect observational data between 2000 and 2014 from a satellite-based dataset for total PM2.5 and from 2469 measurement records in the literature for PM2.5 components. Seven models output total PM2.5 concentrations, and they all underestimate the observed total PM2.5 over eastern China, with GFDL-ESM4 (- 1.5 %) and MPI-ESM-1-2-HAM (- 1.1 %) exhibiting the smallest biases averaged over the whole country. The other seven models, for which we recalculate total PM2.5 from the available component output, underestimate the total PM2.5 concentrations partly because of the missing model representations of nitrate and ammonium. Concentrations of the five individual components are underestimated in almost all models, except that sulfate is overestimated in MPI-ESM-1-2-HAM by 12.6 % and in MRI-ESM2-0 by 24.5 %. The underestimation is the largest for OC (by - 71.2 % to - 37.8 % across the 14 models) and the smallest for BC (- 47.9 % to - 12.1 %). The multi-model mean (MMM) reproduces the observed spatial pattern for OC (R = 0.51), sulfate (R = 0.57), nitrate (R = 0.70) and ammonium (R = 0.74) fairly well, yet the agreement is poorer for BC (R = 0.39). The varying performances of ESMs on total PM2.5 and its components have important implications for the modeled magnitude and spatial pattern of aerosol radiative forcing. [ABSTRACT FROM AUTHOR]

Earth system models (ESMs) participating in the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) simulate various components of fine particulate matter (PM2.5) as major climate forcers. Yet the model performance for PM2.5 components remains little evaluated due in part to lack of observational data. Here, we evaluate near-surface concentrations of PM2.5 and its five main components over China as simulated by fourteen CMIP6 models, including organic carbon (OC, available in 14 models), black carbon (BC, 14 models), sulfate (14 models), nitrate (4 models), and ammonium (5 models). For this purpose, we collect observational data between 2000 and 2014 from a satellite-based dataset for total PM2.5 and from 2469 measurement records in the literature for PM2.5 components. Seven models output total PM2.5 concentrations, and they all underestimate the observed total PM2.5 over eastern China, with GFDL-ESM4 (–1.5 %) and MPI-ESM-1-2-HAM (–1.1 %) exhibiting the smallest biases averaged over the whole country. The other seven models, for which we recalculate total PM2.5 from the available components output, underestimate the total PM2.5 concentrations, partly because of the missing model representations of nitrate and ammonium. Concentrations of the five individual components are underestimated in almost all models, except that sulfate is overestimated in MPI-ESM-1-2-HAM by 12.6 % and in MRI-ESM2-0 by 24.5 %. The underestimation is the largest for OC (by –71.2 % to –37.8 % across the 14 models) and the smallest for BC (–47.9 % to –12.1 %). The multi-model mean (MMM) reproduces fairly well the observed spatial pattern for OC (R = 0.51), sulfate (R = 0.57), nitrate (R = 0.70) and ammonium (R = 0.75), yet the agreement is poorer for BC (R = 0.39). The varying performances of ESMs on total PM2.5 and its components have important implications for the modeled magnitude and spatial pattern of aerosol radiative forcing. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of pure titanium surface of large diameter TiO2 nanotubes modified by RGD peptide on the adhesion and proliferation of MG63 osteoblasts. to provide theoretical proof for developing titani⁃ um implants. Methods Commercially pure titanium discs were divided into four groups and treated with SLA to obtain a microrough surface (SLA group). Then, nanotubes were imposed on this microrough surface by anodization (SLA+ 80 group). The surface was then modified by dopamine (DOPA) (DOPA Group), after which bioactive RGD peptide layers were generated on the TiO2 nanotube surfaces via electrochemical and molecular self⁃assembly techniques (RGD group). The titanium surface morphology and elemental composition of each group were characterized by field emission scanning electron microscopy (FE⁃SEM) and X⁃ray photoelectron spectroscopy (XPS). MG63 cells were cultured in vitro to evalu⁃ ate biological activities of titanium before and after treatment, including the evaluation of early⁃stage cell adhesion capac⁃ ity by fluorescence microscopy, proliferation capacity by MTS assay, and mRNA expression of the cell osteoblast⁃related genes alkaline phosphatase (ALP) and osteocalcin (OCN) by qRT⁃PCR. Results FE⁃SEM and XPS showed that hierar⁃ chical micro/nanosurfaces decorated with TiO2 nanotubes were produced on titanium using sandblasting and large grit etching combined with anodization, dopamine was then self⁃polymerized to form a polydopamine film on the TiO2 nano⁃ tube surfaces, and RGD peptides were then conjugated to the polydopamine film, finally forming RGD peptide⁃modified bioactive layers. In vitro experiments showed that compared with the other three materials, the RGD⁃modified material was more conducive to cell adhesion and proliferation (P < 0.05). The expression levels of ALP and OCN mRNA in the RGD group were significantly higher than those in the SLA group and DOPA group (P < 0.05). Conclusion Hierarchi⁃ cal micro/nanosurfaces decorated with TiO2 nanotubes functionally modified with RGD peptides have good biocompatibil⁃ ity and could be used for developing titanium implants and further improving early osseointegration.

Objective To evaluate the expression of HAase in Oral Squamous Cell Caricinoma (OSCC). Methods The distribution and expression of HAase in 21 patients with OSCC and their resecetions with tumor⁃free margins were examined by immunohistochemistry method. Results HAase were mainly immunostained in tumor tissue. The expres⁃ sion of HAase in oral cancer with nodal metastasis and low pathological grades were higher than that with no nodal me⁃ tastasis and high pathological grades (P < 0.05), whereas no difference between the TNM stages (P > 0. 05). Conclu⁃ sion The HAase levels were high in oral squamous cell carcinoma tissues, and rising in patients with lymph node me⁃ tastasis and poorly differentiated.