Coronary hemodynamic simulation study.

In this paper, a two-way fluid-structure coupling model is developed to simulate and analyze the hemodynamic process based on dynamic coronary angiography, and examine the influence of different hemodynamic parameters on coronary arteries in typical coronary stenosis lesions. Using the measured FFR pressure data of a patient, the pressure-time function curve is fitted to ensure the accuracy of the boundary conditions. The average error of the simulation pressure results compared to the test data is 6.74%. In addition, the results related to blood flow, pressure contour and wall shear stress contour in a typical cardiac cycle are obtained by simulation analysis. These results are found to be in good agreement with the laws of the real cardiac cycle, which verifies the rationality of the simulation. In conclusion, based on the modeling and hemodynamic simulation analysis process of dynamic coronary angiography, this paper proposes a method to assist the analysis and evaluation of coronary hemodynamic and functional parameters, which has certain practical significance.

Cold Stress Induces Apoptosis in Silver Pomfret via DUSP-JNK Pathway.

We cultured silver pomfret for 20 days, decreasing water temperature from 18 to 8 ℃, and sampled muscle every 5 days. Muscle fiber degeneration and apoptosis began to increase at 13 ℃ detected by HE and TUNEL staining. Further analysis of transcriptome revealed that several apoptosis-related pathways were highly enriched by differentially expressed genes (DEGs). We analyzed 10 DEGs from these pathways by RT-qPCR during the temperature-decreasing process. JNK1, PIDD, CytC, Casp 3, and GADD45 were up-regulated after 15 and 20 days, while DUSP3, JNK2, and PARP genes were down-regulated after 15 and 20 days. DUSP5 was up-regulated from 10 to 20 days, and C-JUN was up-regulated after 20 days. We analyzed apoptosis in PaM cells under different temperatures (26 ℃, 23 ℃, 20 ℃, 17 ℃, and 14 ℃). The cell viability significantly declined from 14 to 20 ℃; the TUNEL and IHC results showed that the apoptosis signal increased with the temperature dropping, especially in 17 ℃ and 14 ℃; DUSP5, JNK1, CytC, C-JUN, Casp 3, and GADD45 were up-regulated at 17 ℃ and 14 ℃, and PIDD was up-regulated at 20 ℃, 17 ℃, and 14 ℃. DUSP3 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃, and PARP was down-regulated at 17 ℃ and 14 ℃. JNK2 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃. Our results suggest that DUSP could help inhibit apoptosis in the initial stage of cold stress, but low temperature could down-regulate it and up-regulate JNK-C-JUN, inducing apoptosis in a later stage. These data provide a basis for the study of the response mechanism of fish to cold.

A mini-review on building insulation materials from perspective of plastic pollution: Current issues and natural fibres as a possible solution.

As plastic pollution is eroding our ecological environment at an alarming rate around the world, tracking the origins is a necessity for putting forward effective measures to prevent it. The building industry, as an important sector consuming plastic products and producing plastic wastes, is increasing application of thermal insulations to improve energy efficiency. However, most insulation materials have negative impact on the environment. With the strategies to boost sustainability of buildings, natural fibres have occurred in the market as promising raw materials for thermal insulations. This mini-review aims to describe the extent building insulations contributed to plastic pollution, and a possible solution to plastic pollution from natural fibres and their current shortcomings. Hopefully, the mini-review could advance the current knowledge on contribution of building materials, especially thermal insulations to the ubiquitous plastic pollution, and the potential of natural fibres for replacing the plastic insulations, which could accordingly help future development of sustainable green insulations.

Impacts of terrestrial input on the distribution characteristics of microplastics in the East China Sea characterized by chromophoric dissolved organic matter (CDOM) analysis.

Large quantities of microplastics are found in the East China Sea (ECS), however, the impacts of complicated terrestrial input on the distribution characteristics of microplastics have not been studied. Hence, we aimed to characterize the microplastic distribution in the ECS combined with the fluorescence characteristics of chromophoric dissolved organic matter (CDOM), a sensitive technique to trace terrestrial substances in seawater. The average microplastic abundance in the surface seawater of ECS was 34.73 ± 4.05 items/m3 and sites in the north ECS had a higher microplastic abundance (55.90 ± 2.47 items/m3) than those in the southern region (11.22 ± 4.01 items/m3), due to its proximity to the Yangtze River estuary and Hangzhou Bay. Polyethylene (PE, 44.2 %) was the most abundant microplastic type in the northern region, whereas polyethylene terephthalate (PET, 28.4 %) had a higher proportion in the south ECS. Besides, sites in the north ECS had a higher diversity index of microplastics, suggesting various sources of microplastic pollution. Interestingly, a stronger correlation with the diversity index was found for protein-like component C3 (R2 = 0.56) in northern regions compared to fulvic-like component C1 (R2 = 0.32) and humic-like component C2 (R2 = 0.28), suggesting the significant impact of anthropogenic discharge. Moreover, no correlation between fluorescence components and microplastic diversity index was found in the south ECS, indicating that CDOM can reflect the impact range of terrestrial input on the distribution characteristics of microplastics. This research might be useful in assessing and reducing the impact of terrestrial input on the distribution characteristics of microplastics in the ECS.

Impacts of haze on the photobleaching of chromophoric dissolved organic matter in surface water.

Sunlight plays an important role in the photochemical processes of chromophoric dissolved organic matter (CDOM), which is closely related to water self-purification and primary productivity of healthy aquatic ecosystem health. The fine particles of haze, a widespread air pollutant, absorb natural ultraviolet (UV) irradiation and have an unknown degree of influence on the photochemical transformation of CDOM. Here, an in-situ experiment investigating how the amount and composition of CDOM changes under hazy conditions was conducted in Ningbo, southeastern China, a city that frequently suffers from seasonal haze pollution. The results indicated that haze attenuated UV light under different weather conditions. The UV intensities were reduced from 1124.90 ± 91.58 to 510.26 ± 40.26 µW cm-2 and 748.54 ± 101.68 to 316.32 ± 40.48 µW cm-2 on sunny and cloudy days, respectively; these values approached those on rainy days (186.97 ± 28.58 µW cm-2). Consequently, the loss of dissolved organic carbon during the irradiation test was reduced on hazy days (e.g., from 5.63% to 2.59% on sunny/hazy days). The impact of haze on CDOM photobleaching was further assessed by an excitation-emission matrix (EEM) combined with parallel factor (PARAFAC) analysis. On hazy days, the EEM-PARAFAC components were saved from photobleaching to different degrees; and humic-like substances showed a stronger protective effect from haze than protein-like substances because of their higher photosensitivity. Consequently, haze could cause more terrestrial CDOM to remain in surface water. UV intensity played a critical role in the composition characteristics of CDOM. This study identifies the linkage between atmospheric pollution and water quality and demonstrates that long-term and large-scale haze may adversely influence aquatic ecology through pollutant/nutrient accumulation.

Spatiotemporal variations in chromophoric dissolved organic matter (CDOM) in a mixed land-use river: Implications for surface water restoration.

A challenge for current surface water restoration and management in China is acquiring the source information for complex pollution scenarios in order to develop effective control strategies. As an important part of dissolved organic matter, chromophoric dissolved organic matter (CDOM) contains unique chemical signals related to various pollution sources. Spectral methods such as fluorescence excitation-emission matrices coupled with parallel factor analysis enable rapid and low-cost CDOM characterization for source tracking. In this study, a typical small-sized river flowing through mixed land-use regions in southeastern China, the Lujiang River, was investigated to determine the responses of CDOM to spatiotemporal factors. The effects of land-use patterns were reflected by the fluorescent components of terrestrial and sewage substances. A high and stable proportion of terrestrial-like components (C1 + C2) in each sampling period (i.e., March: 47.6 ± 5.7% and October: 44.3 ± 2.7%) indicated a high input of non-point source (NPS) pollution from both agriculture and urban areas. In addition, the difference in solar radiation intensity induced by climate and air quality changes was also reflected by variability in the photodegradation product component (C3) of terrestrial precursors between October (24.8 ± 2.6%) and March (4.5 ± 2.0%), suggesting that terrestrial components could be a sensitive indicator for NPS pollutant monitoring. Increased sewage impact in downstream regions was reflected by a spike in the tryptophan-like component (C4); temporal variations in C4 (paired t-Test, p < 0.005) also indicated that sewage substances were more prone to removal by microbial activity in warmer seasons. The dynamics of C4 could serve as a good indicator of sewage disposal performance. The results of this study demonstrate that CDOM data have important practical applications for existing water restoration campaigns in southeastern China, as well as substantial potential for routine water quality monitoring.

Sorption behaviors of phenanthrene on the microplastics identified in a mariculture farm in Xiangshan Bay, southeastern China.

Recently, with the accumulation of evidence that microplastic can be ingested by a variety of marine organisms, microplastic sorption behaviors towards organic contaminants (OCs) have become the subject of more studies due to the concerns about the contaminant vector effect. In this study, the priority microplastics identified in a mariculture farm in Xiangshan Bay, China, including polyethylene (PE) and nylon fibers (i.e., derived from new fishing ropes and nets), were examined for their sorption behaviors. The results indicate that both plastic fibers show linear isotherms towards phenanthrene, a common target hydrophobic organic contaminant (HOC), revealing the characteristics of a partitioning mechanism. The sorption capacity of PE fiber was found to be 1-2 orders of magnitude higher (evaluated by Freundlich parameter log KF) than that of nylon fiber, suggesting the importance of plastic surface functional groups (i.e., with or without hydrophilic groups). By comparing carbon normalized log KF with literature data, the organic affinity of PE fiber was found to be 1-2 orders of magnitude lower than that of vectors, such as carbonaceous geosorbents (CG), but was 1-2 orders of magnitude higher than that of marine sediments. Small size and rough surface tended to enhance the sorption of plastic fibers of phenanthrene. In addition, phenol (log KOW: 1.46), a low-hydrophobicity compound, showed approximately 3 orders of magnitude lower sorption amounts onto both fibers compared to phenanthrene (log KOW: 4.46), indicating the selectivity of hydrophobicity. The results of this study demonstrate that the high abundance of plastic fibers distributed in mariculture farms could lead to a higher contaminant transfer effect than marine sediments, and their effects on cultured seafood (e.g., crab and fish) need further investigation.

Impacts of land-use on surface waters at the watershed scale in southeastern China: Insight from fluorescence excitation-emission matrix and PARAFAC.

In recent years, the Chinese government has strengthened its efforts in surface water protection and restoration through strict policies and heavy investments. A clear understanding of the impacts of land use on water quality is necessary in order to ensure an effective and efficient implementation of the ongoing surface water restoration program in China. To this end, four small watersheds (less than 5000 ha) in southeastern China, which have clear gradients in the intensities of agriculture (17.0-45.4%), forest (35.2-73.6%) and built-up area (3.3-8.5%), were investigated regarding the impacts of land use on water quality. In addition to the general water quality indices, characteristic components derived by fluorescence excitation-emission matrices (FEEMs) coupled with parallel factor analysis (PARAFAC) were employed to explore a more accurate association between land use and water quality. The results show that agricultural intensity has significant effects by elevating the concentrations of dissolved organic carbon (DOC, an approximate six-fold increase) and total phosphorous (TP, an approximate four-fold increase) in the surface waters. A total of five PARAFAC components representing terrestrial (three components) and protein-like (two components) substances were identified. The PARAFAC results indicate that land-use patterns affected the dissolved organic matter (DOM) in the aspects of both amount and composition. The intensity (R.U.) of the terrestrial components showed a strong correlation (r2 = 0.95, p = 0.01) with agricultural land percentage. Moreover, although the proportion of built-up area varies with a relatively small range, a protein-like component could predict its impact with excellent sensitivity (r2 = 0.94, p = 0.02), whereas the general water quality indices were incapable of predicting the impact due to their multiple sources. The results of this study demonstrate that the FEEMs-PARAFAC technique provides an inexpensive and effective tool for policy makers to overcome the insensitivity of general water quality indices, particularly for the restoration of watersheds with complex land-use patterns.