Legacy and emerging organophosphate flame retardants (OPFRs) in water and sediment from the Pearl River Delta to the adjacent coastal waters of the South China Sea: Spatioseasonal variations, flux estimation and ecological risk.

The industrialization and urbanization along the Pearl River Delta (PRD) have exacerbated the issue of pollution in aquatic environments by organophosphate flame retardants (OPFRs). Historical cumulative pollution from legacy OPFRs, combined with newly emerging OPFRs, has increased the severity and complexity of OPFR pollution in this region. We explored the contamination profile, input flux and risk of legacy and emerging OPFRs in surface waters and in sediment samples of the PRD.

Socioeconomic disparities in treatment and survival in patients with hypopharyngeal malignancy.

Background: This retrospective study utilizes The Surveillance, Epidemiology, and End Results database to investigate socioeconomic factors leading to treatment disparities in hypopharyngeal malignancy.

Methods: Treatment was compared to National Cancer Care Network guidelines. Novel analyses, including logistic modeling, allowed survival analysis and identification of socioeconomic variables not previously considered in staging and management guidelines.

Low particle concentrations of nanoplastics impair the gut health of medaka.

The environmental occurrence of nanoplastics (NPs) is now evident but their long-term impacts on organisms are unclear, limiting ecological and health risk assessment. We hypothesized that chronic exposure to low particle concentrations of NPs can result in gut-associated toxicity, and subsequently affect survival of fish. Japanese medaka Oryzias latipes were exposed to polystyrene NPs (diameter 100 nm; 0, 10, 10, and 10 items/L) for 3 months, and histopathology, digestive and antioxidant enzymes, immunity, intestinal permeability, gut microbiota, and mortality were assessed.

Chronic nanoplastic exposure induced oxidative and immune stress in medaka gonad.

Nanoplastic (NP) pollution is a global issue because of its widespread occurrence and potential toxicity. Many studies have investigated the impacts of the short-term toxicity of NPs on organisms. Until now, only a few studies have assessed the toxicological effects of prolonged exposure to NPs at low concentrations in fish.

[Application of hand-use ProTaper instruments in endodontic treatment of molar canals].

Objective: To evaluate the application of hand-use ProTaper instruments in endodontic treatment of molar canals.

Methods: A total of 203 permanent molars were randomly divided into the experimental group (99 molars) and control group (104 molars) prepared by hand-use ProTaper instruments and standard stainless steel K-file, respectively. The molars in the two groups were obturated by cold lateral condensation technique.