Factors Influencing O3 Concentration in Traffic and Urban Environments: A Case Study of Guangzhou City.

Ozone (O3) pollution is a serious issue in China, posing a significant threat to people's health. Traffic emissions are the main pollutant source in urban areas. NOX and volatile organic compounds (VOCs) from traffic emissions are the main precursors of O3. Thus, it is crucial to investigate the relationship between traffic conditions and O3 pollution. This study focused on the potential relationship between O3 concentration and traffic conditions at a roadside and urban background in Guangzhou, one of the largest cities in China. The results demonstrated that no significant difference in the O3 concentration was observed between roadside and urban background environments. However, the O3 concentration was 2 to 3 times higher on sunny days (above 90 µg/m3) than on cloudy days due to meteorological conditions. The results confirmed that limiting traffic emissions may increase O3 concentrations in Guangzhou. Therefore, the focus should be on industrial, energy, and transportation emission mitigation and the influence of meteorological conditions to minimize O3 pollution. The results in this study provide some theoretical basis for mitigation emission policies in China.

Sub-Block Urban Function Recognition with the Integration of Multi-Source Data.

The recognition of urban functional areas (UFAs) is of great significance for the understanding of urban structures and urban planning. Due to the limitation of data sources, early research was characterized by problems such as singular data, incomplete results, and inadequate consideration of the socioeconomic environment. The development of multi-source big data brings new opportunities for dynamic recognition of UFAs. In this study, a sub-block function recognition framework that integrates multi-feature information from building footprints, point-of-interest (POI) data, and Landsat images is proposed to classify UFAs at the sub-block level using a random forest model. The recognition accuracies of single- and mixed-function areas in the core urban area of Guangzhou, China, obtained by this framework are found to be significantly higher than those of other methods. The overall accuracy (OA) of single-function areas is 82%, which is 8-36% higher than that of other models. The research conclusions show that the introduction of the three-dimensional (3D) features of buildings and finer land cover features can improve the recognition accuracy of UFAs. The proposed method that uses open access data and achieves comprehensive results provides a more practical solution for the recognition of UFAs.

Extraction and Analysis of Blue Steel Roofs Information Based on CNN Using Gaofen-2 Imageries.

Blue steel roof is advantageous for its low cost, durability, and ease of installation. It is generally used by industrial areas. The accurate and rapid mapping of blue steel roof is important for the preliminary assessment of inefficient industrial areas and is one of the key elements for quantifying environmental issues like urban heat islands. Here, the DeeplabV3+ semantic segmentation neural network based on GaoFen-2 images was used to analyze the quantity and spatial distribution of blue steel roofs in the Nanhai district, Foshan (including the towns of Shishan, Guicheng, Dali, and Lishui), which is the important manufacturing industry base of China. We found that: (1) the DeeplabV3+ performs well with an overall accuracy of 92%, higher than the maximum likelihood classification; (2) the distribution of blue steel roofs was not even across the whole study area, but they were evenly distributed within the town scale; and (3) strong positive correlation was observed between blue steel roofs area and industrial gross output. These results not only can be used to detect the inefficient industrial areas for regional planning but also provide fundamental data for studies of urban environmental issues.

Sesamin promotes angiogenesis and accelerates wound healing in rats via alleviates TBHP-induced apoptosis in human umbilical vein endothelial cells.

Acute stress induces tissue damage through excessive cellular apoptosis. In our study, the effects of sesamin on apoptosis and wound healing were investigated. The angiogenesis effect of sesamin was evaluated by the abilities of adherence, migration and tube formation in human umbilical vein endothelial cells (HUVECs). Our data demonstrated that treatment with sesamin dose-dependently promoted the proliferation, adherence, migration and enhanced their angiogenic ability in vitro. Moreover, the increased apoptosis in HUVECs, which stimulated by tert-butyl hydroperoxide (TBHP) was significantly attenuated by the sesamin treatment. Furthermore, we revealed that neogenesis of granulation tissue and deposition and remodeling of the collagen matrix were accelerated by the administration of sesamin in our in vivo study. These results confirm that sesamin accelerates wound healing at least partly through its antiapoptotic effects on endothelial cells at the injury site. Thus, sesamin represents a potential therapeutic medicine for vessel injury-related wounds.

Determination of cepharanthine in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

CONTEXT: Cepharanthine (CPA) has been reported to possess a wide range of pharmacological activities. OBJECTIVE: This study investigates the pharmacokinetic characteristics after oral or intravenous administration of CPA by using a sensitive and rapid LC-MS/MS method. MATERIALS AND METHODS: A sensitive and rapid LC-MS/MS method was developed for the determination of CPA in Sprague-Dawley rat plasma. Twelve rats were equally randomized into two groups, including the intravenous group (1 mg/kg) and the oral group (10 mg/kg). Blood samples (250 µL) were collected at designated time points and determined using this method. The pharmacokinetic parameters were calculated. RESULTS: The calibration curve was linear within the range of 0.1-200 ng/mL (r = 0.999) with the lower limit of quantification at 0.1 ng/mL. After 1 mg/kg intravenous injection, the concentration of CPA reached a maximum of 153.17 ± 16.18 ng/mL and the t1/2 was 6.76 ± 1.21 h. After oral administration of 10 mg/kg of CPA, CPA was not readily absorbed and reached Cmax 46.89 ± 5.25 ng/mL at approximately 2.67 h. The t1/2 was 11.02 ± 1.32 h. The absolute bioavailability of CPA by oral route was 5.65 ± 0.35%, and the bioavailability was poor. DISCUSSION AND CONCLUSIONS: The results indicate that the bioavailability of CPA was poor in rats, and further research should be conducted to investigate the reason for its poor bioavailability and address this problem.

Increased Expression of miR-29a and Its Prognostic Significance in Patients with Cholangiocarcinoma.

BACKGROUND: This study aimed to examine the expression level and prognostic value of microRNA-29a (miR-29a) in human cholangiocarcinoma (CCA). PATIENTS AND METHODS: The expression of miR-29a was measured in tissues collected from 125 CCA patients using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Survival analysis was carried out using the Kaplan-Meier method and log-rank test. The prognostic value of miR-29a was examined with Cox regression analysis. RESULTS: The results of qRT-PCR demonstrated that miR-29a expression was significantly upregulated in CCA tissue samples compared with matched noncancerous samples. Overexpression of miR-29a was found to be correlated with lymph node metastasis, clinical stage, and differentiation of CCA. The Kaplan-Meier survival curves suggested that patients with high miR-29a levels had poor overall survival compared to those with low miR-29a expression. From the results of the Cox regression analysis, we considered increased miR-29a expression to be an independent prognostic factor for patients with CCA. CONCLUSION: Our study data demonstrated that upregulated miR-29a expression is associated with progression of CCA and might act as a prognostic biomarker in CCA patients.

Extraction and analysis of impervious surfaces based on a spectral un-mixing method using Pearl River Delta of China Landsat TM/ETM+ imagery from 1998 to 2008.

Impervious surface area (ISA) is considered as an indicator of environment change and is regarded as an important input parameter for hydrological cycle simulation, water management and area pollution assessment. The Pearl River Delta (PRD), the 3rd most important economic district of China, is chosen in this paper to extract the ISA information based on Landsat images of 1998, 2003 and 2008 by using a linear spectral un-mixing method and to monitor impervious surface change by analyzing the multi-temporal Landsat-derived fractional impervious surface. Results of this study were as follows: (1) the area of ISA in the PRD increased 79.09% from 1998 to 2003 and 26.88% from 2003 to 2008 separately; (2) the spatial distribution of ISA was described according to the 1998/2003 percentage respectively. Most of middle and high percentage ISA was located in northwestern and southeastern of the whole delta, and middle percentage ISA was mainly located in the city interior, high percentage ISA was mainly located in the suburban around the city accordingly; (3) the expanding direction and trend of high percentage ISA was discussed in order to understand the change of urban in this delta; High percentage ISA moved from inner city to edge of urban area during 1998-2003 and moved to the suburban area that far from the urban area mixed with jumpily and gradually during 2003-2008. According to the discussion of high percentage ISA spatial expanded direction, it could be found out that high percentage ISA moved outward from the centre line of Pearl River of the whole delta while a high ISA percentage in both shores of the Pearl River Estuary moved toward the Pearl River; (4) combining the change of ISA with social conditions, the driving relationship was analyzed in detail. It was evident that ISA percentage change had a deep relationship with the economic development of this region in the past ten years. Contemporaneous major sport events (16th Asia Games of Guangzhou, 26th Summer Universidad of Shenzhen) and the government policies also promoted the development of the ISA. Meanwhile, topographical features like the National Nature Reserve of China restricted and affected the expansion of the ISA. Above all, this paper attempted to extract ISA in a major region of the PRD; the temporal and spatial analyses to PRD ISA demonstrated the drastic changes in developed areas of China. These results were important and valuable for land use management, ecological protection and policy establishment.