Levels, sources, and health risk assessment of phthalate acid esters in indoor dust of various microenvironments in university.

Phthalate acid esters (PAEs), as a common group of plasticizers, are widely present in indoor environments and pose a risk to human health. Indoor dust samples collected from dormitory, classroom, laboratory, and office in several universities in China, were analyzed for seven types of PAEs. The total concentrations of seven PAEs (Σ7PAEs) ranged from 4.87 to 360 µg/g, with a median concentration of 51 µg/g, which is lower than that reported by other studies. Using the median concentration of Σ7PAEs as a metric, we assessed the levels of contamination in different microenvironments, resulting in the following ranking: dormitory > classroom > laboratory > office. There are significant differences in the levels of individual PAEs in different microenvironments. Radiation from sunlight, ventilation rates, cleaning frequency, and sprays were influential factors for the concentrations of individual PAEs in indoor dust. The indoor environmental conditions and consumption patterns profoundly affect PAEs levels. The sources of PAEs in classroom and office were more complex than in dormitory and laboratory. Daily intakes of PAEs were used to calculate carcinogenic and non-carcinogenic human risk for males and females, indicating a low health risk to humans. This is the first study to assess the risk of PAEs in university microenvironments and provides a valuable reference for further research.

Residual distribution and risk assessment of neonicotinoids in urban green space soils of the pearl river delta, South China: A socioeconomic analysis.

Urban green spaces are the soil component in cities that interacts most closely with humans. This study investigated the residues of seven neonicotinoids (NEOs) in soils from urban green spaces within the Pearl River Delta (PRD) region and analyzed the correlation between the residue characteristics and the region's economic development. Notably, we introduced the Nemerow Index method, a comprehensive approach, to quantify the overall pollution level of NEOs in the soil of urban park green spaces and utilized this to assess the cumulative exposure probability risks for different populations in this scenario. We found that: (1) The soil of urban park green spaces exhibited varying degrees of NEOs contamination (Σ7NEOs: N.D.-137.31; 6.25 µg/kg), with imidacloprid and clothianidin constituting the highest proportions (89.46 % and 83.60 %); (2) The residual levels of NEOs in Children's Park were significantly higher than those in community parks within Guangzhou, with an average value of 13.30 µg/kg compared to 3.30 µg/kg; (3) The residual characteristics of NEOs exhibited a positive correlation with regional economic development; specifically, the per capita GDP well correlated with IMIRPF, a summation of seven NEOs in imidacloprid equivalents via relative potency factors (R2 =0.86). Regions with higher economic development typically exhibited elevated IMIRPF levels; (4) The fitted cumulative probability distributions for average daily exposure doses revealed that children's exposure was an order of magnitude higher than adults'. Despite this, the exposure risks for both groups remained within acceptable limits.

[Potential Ecological Risk Characteristics and Source Apportionment of Heavy Metals in Farmland Soils around Typical Factories in Hunan Province Based on Monte-Carlo Simulation].

In order to explore the pollution characteristics， ecological risks， and pollution sources of heavy metals in farmland soils around typical factories in Hunan Province， the content characteristics of eight heavy metals in farmland soils around fluoride factories， leather factories， and plating plants were analyzed. The geo-accumulation index and potential ecological risk index were used to evaluate the pollution and environmental risk of heavy metals. The correlation analysis， hierarchical cluster analysis， and principal component analysis were used to analyze the sources of heavy metals. The Monte-Carlo model was used to evaluate the probability risk of regional ecological risk. The results showed that the main pollution elements in the soil were Cd and Zn， and their mean values were 4.46 and 2.73 times the background values， respectively. Zn was at a mild pollution level in the soil of the three typical factories， and Cd was at a moderate pollution level in the whole fluoride factory. The pollution sources of heavy metals in the typical factories were mainly natural sources， industrial activity sources （industrial waste discharge， mineral mining， and smelting activities）， traffic sources， etc. The results of potential ecological risk assessment showed that the ecological risk of the fluoride factory was at a high risk level， and the ecological risk of the leather factory and plating plants was at a high risk level. Cd was the main contributing element. The results of Monte-Carlo probabilistic ecological risk assessment reduced the uncertainty of deterministic assessment， which could provide scientific basis for accurate risk management and control in the regions.

Mechanical Properties of Bulk Metallic Glasses Additively Manufactured by Laser Powder Bed Fusion: A Review.

Bulk metallic glasses (BMGs) display excellent strength, high hardness, exceptional wear resistance and corrosion resistance owing to its amorphous structure. However, the manufacturing of large-sized and complex shaped BMG parts faces significant difficulties, which seriously hinders their applications. Laser powder bed fusion (LPBF) is a typical additive manufacturing (AM) technique with a cooling rate of up to 108 K/s, which not only allows for the formation of amorphous structures but also solves the forming problem of complex-shaped BMG parts. In recent years, a large amount of work has been carried out on the LPBF processing of BMGs. This review mainly summarizes the latest progress in the field of LPBF additively manufactured BMGs focusing on their mechanical properties. We first briefly review the BMG alloy systems that have been additively manufactured using LPBF, then the mechanical properties of LPBF-fabricated BMGs including the micro- and nano-hardness, micropillar compressive performance, and macro-compressive and tensile performance are clarified. Next, the relationship between the mechanical properties and microstructure of BMGs produced via LPBF are analyzed. Finally, the measures for improving the mechanical properties of LPBF-fabricated BMGs are discussed. This review can provide readers with an essential comprehension of the structural and mechanical properties of LPBF-manufactured BMGs.

A High-Performance Liquid Chromatography with Electrochemical Detection Method Developed for the Sensitive Determination of Ascorbic Acid: Validation, Application, and Comparison with Titration, Spectrophotometric, and High-Performance Liquid Chromatography with Diode-Array Detection Methods.

L-ascorbic acid (vitamin C, VC), an essential nutrient obtained from the diet to maintain various vital signs for the human body, is a crucial indicator of food quality and nutritional value. Herein, high-performance liquid chromatography with electrochemical detection (HPLC-ECD) was developed and validated with the advantages of higher sensitivity, simpler operation processes, and more rapid detection in measuring VC levels in honey samples when compared with the common methods (titration, spectrophotometric, and HPLC-DAD methods). The results of the HPLC-ECD methodological validation showed that the limit of detection (LOD) was 0.0043 µg mL-1; the relative standard deviations (RSDs) of the intra- and inter-day values were between 2.51% and 5.15%, and the regression coefficient was >0.999 in the linear range of 0.1 to 20 µg mL-1. The validated HPLC-ECD method was also successfully utilized to evaluate the VC levels in different varieties of honey samples with various storage durations as well as in fruit and biological samples. This study provided a perspective for the further accurate determination of VC content in food and biological samples.

Stereoselective Synthesis of trans-Decalin-Based Spirocarbocycles via Photocyclization of 1,2-Diketones.

Diastereoselective synthesis of the trans-decalin-based α-hydroxyl butanone spirocarbocycles bearing all-carbon quaternary stereogenic centers has been achieved via Norrish-Yang photocyclization of trans-decalin-substituted-2,3-butanediones using daylight. Density functional theory (DFT) calculations suggest that this diastereoselective reaction is affected by both substrate conformation and intramolecular hydrogen bonds. The developed chemistry could be applied to synthesizing the derivatives of the trans-decalin-based biologically important natural products.

USP19 Enhances MMP2/MMP9-Mediated Tumorigenesis in Gastric Cancer.

BACKGROUND: To investigate the clinical significance of ubiquitin-specific peptidase 19 (USP19) expression in gastric cancer (GC) compared with that in normal tissues and gastric cell lines. METHODS: USP19 protein expression was analyzed in 212 paired GC samples using immunohistochemical staining. Quantitative real-time PCR (qRT-PCR) and Western blotting were used to detect the level of USP19 in gastric cell lines. The biological functions of USP19 were investigated by MTT assay, colony-forming assay, wound healing assay and gelatin zymography, and apoptotic cells were detected by immunohistochemistry assays in SGC7901 xenograft models. RESULTS: USP19 expression was significantly increased in GC cells and tissues, and the high level of USP19 expression was positively correlated with the Lauren's classification and poor prognosis. Moreover, USP19 was identified as a novel independent prognostic biomarker in GC patients. Enhanced USP19 expression promoted GC cell proliferation and metastasis through reduced cleaved caspase-3 and increased MMP2/MMP9 expression and promoted enzyme activity in the study, and verified the results through The Cancer Genome Atlas (TCGA) and bioinformatic websites from the Kaplan-Meier plotter (http://kmplot.com) and GEPIA (http://gepia2.cancer-pku.cn.). CONCLUSION: Our study suggests that USP19 promoted tumor progression by inducing MMP2/MMP9 expression and related enzyme activity. Hence, USP19 may be a valuable prognostic predictor for GC, and the USP19-MMP2/MMP9 axis could serve as a therapeutic target.

G59S mutation in the GJB2 gene in a Chinese family with classic Vohwinkel syndrome.

Vohwinkel syndrome (VS) is a rare autosomal dominant condition, also known as mutilating palmoplantar keratoderma accompanied by sensorineural deafness. The LOR and GJB2 genes are reported to be responsible for VS. The GJB2 gene encodes connexin 26, a component of intercellular gap junctions expressed in various tissues. We report the case of a 31-year-old Chinese woman with classic VS characterized by sensorineural deafness and mutilating palmoplantar keratoderma. Further genetic studies demonstrated a nucleotide change (c.175G>A) in the GJB2 gene, leading to an amino acid alteration (G59S). This identical missense mutation (G59S) has also been reported in a patient with Bart-Pumphrey syndrome. Together with our findings and previous studies, we conclude that the identical mutation (G59S) in the GJB2 gene contributes to various manifestations.

The value of endoscopic ultrasonography in defining longitudinal gross target volumes for esophageal squamous carcinoma.

BACKGROUND AND PURPOSE: To investigate the differences between endoscopic ultrasonography (EUS)-based longitudinal gross target volumes (GTV) (GTV(EUS)) and computed tomography (CT)-based longitudinal GTV (GTV(CT)) in diagnosing esophageal squamous carcinoma. METHODS: Thirty-six patients underwent EUS to define the superior and inferior extents of the tumor by using hemoclips. CT-planning scan was performed with the patient in the supine position during the treatment. GTV(CT) and GTV(EUS) were contoured respectively. The respective lengths (L(CT) and L(EUS)) and spatial locations of longitudinal GTV(CT) and longitudinal GTV(EUS) were compared. RESULTS: The mean LCT was 7.8 ± 3.2 cm and the mean L(EUS) was 7.4 ± 2.7 cm. No statistical difference was found between L(CT) and L(EUS) (P > 0.05) with a correlation coefficient of 0.61 (P<0.05). The mean conformal index was 0.79 ± 0.18 with spatial variations found in 71% (24/34) of the patients. CONCLUSIONS: EUS can provide additional information to CT in defining longitudinal GTV in thoracic esophageal squamous cell carcinoma, especially superficial and submucosal carcinomas, which may contribute to the development of better individual treatment regimens.