The Role of Sargahydroquinoic Acid and Sargachromenol in the Anti-Inflammatory Effect of Sargassum yezoense.

The anti-inflammatory effect of the ethanol extract of Sargassum yezoense and its fractions were investigated in this study. The ethanol extract exhibited a strong anti-inflammatory effect on lipopolysaccharide-stimulated RAW 264.7 macrophages and effectively suppressed the M1 polarization of murine bone-marrow-derived macrophages stimulated by lipopolysaccharides and IFN-γ (interferon-gamma). Through a liquid-liquid extraction process, five fractions (n-hexane, chloroform, ethyl acetate, butanol, and aqueous) were acquired. Among these fractions, the chloroform fraction (SYCF) was found to contain the highest concentration of phenolic compounds, along with two primary meroterpenoids, sargahydroquinoic acid (SHQA) and sargachromenol (SCM), and exhibit significant antioxidant capacity. It also demonstrated a robust anti-inflammatory effect. A direct comparison was conducted to assess the relative contribution of SHQA and SCM to the anti-inflammatory properties of SYCF. The concentrations of SHQA and SCM tested were determined based on their relative abundance in SYCF. SHQA contributed to a significant portion of the anti-inflammatory property of SYCF, while SCM played a limited role. These findings not only highlight the potential of the chloroform-ethanol fractionation approach for concentrating meroterpenoids in S. yezoense but also demonstrate that SHQA and other bioactive compounds work additively or synergistically to produce the potent anti-inflammatory effect of SYCF.

The interactive reading task: Transformer-based automatic item generation.

Automatic item generation (AIG) has the potential to greatly expand the number of items for educational assessments, while simultaneously allowing for a more construct-driven approach to item development. However, the traditional item modeling approach in AIG is limited in scope to content areas that are relatively easy to model (such as math problems), and depends on highly skilled content experts to create each model. In this paper we describe the interactive reading task, a transformer-based deep language modeling approach for creating reading comprehension assessments. This approach allows a fully automated process for the creation of source passages together with a wide range of comprehension questions about the passages. The format of the questions allows automatic scoring of responses with high fidelity (e.g., selected response questions). We present the results of a large-scale pilot of the interactive reading task, with hundreds of passages and thousands of questions. These passages were administered as part of the practice test of the Duolingo English Test. Human review of the materials and psychometric analyses of test taker results demonstrate the feasibility of this approach for automatic creation of complex educational assessments.

Non-monotonic concentration-response relationship of TiO(2) nanoparticles in freshwater cladocerans under environmentally relevant UV-A light.

The effects of UV-A on the toxicity of TiO2 nano-particles (NPs) were evaluated using Moina macrocopa and Daphnia magna under environmentally relevant level of UV-A. The waterfleas were exposed to TiO2 NPs with different sizes of ~298nm, ~132nm, or ~72nm for up to 48h, with or without UV-A light. Whole body reactive oxygen species and transcription of antioxidant enzyme genes were measured, as well as the survival of the waterflea. In the presence of UV-A, the survival rates of M. macrocopa significantly decreased in concentration dependent way until ~1mg/L TiO2 NPs, but the survivals were reversed at greater concentrations. This peculiar non-monotonic trend of concentration-response relationship might be explained by changes of particle size under different light conditions. TiO2 NPs within a certain size range could be trapped in the filter apparatus and exert toxicity, and the NPs of greater size were subject to either precipitation or ingestion leading to no or little toxicity. Observed TiO2 toxicity was associated with oxidative stress in the filter apparatus. The results of this study showed that the size change due to UV-A irradiation should be considered in evaluation of ecological risks of TiO2 NP.

Effect of chronic exposure to acetaminophen and lincomycin on Japanese medaka (Oryzias latipes) and freshwater cladocerans Daphnia magna and Moina macrocopa, and potential mechanisms of endocrine disruption.

Chronic toxicity of acetaminophen and lincomycin were evaluated using freshwater organisms including two crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). H295R, a human adrenal cell was also used to understand the effects on steroidogenesis. In 21 d D. magna exposure, survival NOEC was found at 5.72 mg L(-1) and no reproduction related effects were noted at this level of exposure to acetaminophen, while 21 d survival or growth effects were not observed even at the highest exposure levels (153 mg L(-1)) for lincomycin. In the chronic fish toxicity test, significant reduction in juvenile survival was observed at 30 d post-hatch (dph) at 95 mg L(-1) of acetaminophen, and 0.42 mg L(-1) of lincomycin. After the exposure to both pharmaceuticals, vitellogenin levels tended to increase in male fish at 90 dph. In the eggs which were prenatally exposed to 9.5 mg L(-1) of acetaminophen, reduced hatchability was observed. The results of H295R cell assay showed that both pharmaceuticals could alter steroidogenic pathway and increase estrogenicity. Endocrine disruption potentials and their ecological implication may deserve further studies. Our observations suggest however that ecological risks of both pharmaceuticals are negligible at the concentrations currently found in the environment.

Phototoxicity of CdSe/ZnSe quantum dots with surface coatings of 3-mercaptopropionic acid or tri-n-octylphosphine oxide/gum arabic in Daphnia magna under environmentally relevant UV-B light.

The potential ecotoxicological consequences about semiconductor crystal nanoparticles (NPs) are a growing concern. However, our understanding of the mechanism of toxicity in NPs is very limited, especially under varying environmental conditions such as ultraviolet (UV) light. We performed an in vivo study employing Daphnia magna to evaluate the mechanism involved in toxicity of cadmium selenide/zinc selenide quantum dots (QDs) with two different organic coatings under an environmental level of UV-B light. We used QDs with mercaptopropionic acid (MPA) and tri-n-octylphosphine oxide/gum arabic (GA) and measured their toxicities under an environmental level of UV-B light. Whole-body reactive oxygen species (ROS) generation and mRNA expression level biomarkers, as well as acute toxicity, were measured in D. magna. With UV-B light, both cadmium (Cd) and GA-QD became more toxic in daphnids. The levels of small Cd molecules (<10kDa cutoff) increased for GA-QD under UV-B; however, the observed acute lethal toxicity could not be explained by the measured Cd level. Under UV-B light, both Cd and GA-QD generated more ROS. In addition, the expression pattern of mRNAs specific to Cd exposure was not observed from GA-QD with or without UV-B light. These observations suggest that the phototoxicity of QDs may be explained not only by Cd release from the QD core but also by stability of surface coating characteristics and other potential causes such as ROS generation.

Phototoxicity and oxidative stress responses in Daphnia magna under exposure to sulfathiazole and environmental level ultraviolet B irradiation.

Sulfonamide antibiotics frequently occur in aquatic environments. In this study, phototoxicity of sulfathiazole (STZ) and its mechanism of action were investigated using Daphnia magna. We evaluated the changes of molecular level stress responses by assessing gene expression, enzyme induction and lipid peroxidation, and the related organism-level effects in D. magna. In the presence of ultraviolet B (UV-B) light (continuous irradiation with 13.8+/-1.0microWcm(-2)d(-1)), STZ (at the nominal concentration of 94.9mg/L) caused a significant increase in reactive oxygen species (ROS) generation and lipid peroxidation. Catalase (CAT) and glutathione S-transferase (GST) showed concentration-dependent increases caused by the exposure. Exposure to STZ and UV-B light caused apparent up-regulation of alpha-esterase, hemoglobin, and vitellogenin mRNA. The survival of daphnids was significantly affected by the co-exposure to STZ and UV-B. The biochemical and molecular level observations in combination with organism-level effects suggest that the phototoxicity of STZ was mediated in part by ROS generated by oxidative stress in D. magna.