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1.
Neuromolecular Med ; 26(1): 17, 2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38684592

ABSTRACT

Post-stroke neuroinflammation affects the damage and recovery of neurological functions. T cells including CD8+ T cells were present in the ipsilateral hemisphere in the subacute and late phases of ischemic stroke. However, the potential roles of CD8+ T cell subsets in the progression of neuroinflammation have not been characterized. In the current mouse transient middle cerebral artery occlusion model, we investigated the existence of CD8+ T cell subsets in the ipsilateral hemisphere in the subacute and late phases of stroke. We found that ipsilateral CD8+ T cells were present on post-stroke day 3 and increased on post-stroke day 30. The day-3 ipsilateral CD8+ T cells predominantly produced interferon-γ (IFN-γ), while the day-30 ipsilateral CD8+ T cells co-expressed IFN-γ and interleukin-17A (IL-17A). In addition, evaluation of cytokines and transcription factors of the day-30 ipsilateral CD8+ T cells revealed the presence of T cytotoxic 1 (Tc1), T cytotoxic 17 (Tc17), and T cytotoxic 17/1 (Tc17/1) cells. Furthermore, based on the expression of a series of chemokine/cytokine receptors, viable ipsilateral Tc1, Tc17, and Tc17.1 cells were identified and enriched from the day-30 ipsilateral CD8+ T cells, respectively. Co-culture of microglia with ipsilateral Tc1, Tc17, or Tc17.1 cells indicated that the three CD8+ T cell subsets up-regulated the expression of pro-inflammatory mediators by microglia, with Tc17.1 cells being the most potent cell in doing so. Collectively, this study sheds light on the contributions of Tc1, Tc17, and Tc17.1 cells to long-term neuroinflammation after ischemic stroke.


Subject(s)
Infarction, Middle Cerebral Artery , Interleukin-17 , Mice, Inbred C57BL , Microglia , Neuroinflammatory Diseases , T-Lymphocytes, Cytotoxic , Animals , Microglia/metabolism , Mice , Male , Infarction, Middle Cerebral Artery/immunology , Infarction, Middle Cerebral Artery/pathology , T-Lymphocytes, Cytotoxic/immunology , Neuroinflammatory Diseases/etiology , Ischemic Stroke/immunology , Interferon-gamma/biosynthesis , Brain , Th17 Cells/immunology , Disease Models, Animal , CD8-Positive T-Lymphocytes , Coculture Techniques , Cells, Cultured
4.
Zookeys ; 1192: 213-235, 2024.
Article in English | MEDLINE | ID: mdl-38433760

ABSTRACT

A new bush frog species is described from Yunnan, China, based on phylogenetic analyses, species delimitation analyses, and morphological comparisons. Raorchesteshekouensissp. nov. is distinguished from all other congeners by a combination of 11 morphological characters. The new species brings the current number of Raorchestes species in China to ten, nine of which are distributed in Yunnan. Molecular analyses supported an unnamed lineage previously recorded as "Raorchestesgryllus" in northern Vietnam. Further studies including additional samples are necessary to clarify the species diversity and boundaries of Raorchestes in China and Indochina.

5.
Angew Chem Int Ed Engl ; 63(13): e202401074, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38311965

ABSTRACT

The electronic structure of metal complexes plays key roles in determining their catalytic features. However, controlling electronic structures to regulate reaction mechanisms is of fundamental interest but has been rarely presented. Herein, we report electronic tuning of Cu porphyrins to switch pathways of the hydrogen evolution reaction (HER). Through controllable and regioselective ß-oxidation of Cu porphyrin 1, we synthesized analogues 2-4 with one or two ß-lactone groups in either a cis or trans configuration. Complexes 1-4 have the same Cu-N4 core site but different electronic structures. Although ß-oxidation led to large anodic shifts of reductions, 1-4 displayed similar HER activities in terms of close overpotentials. With electrochemical, chemical and theoretical results, we show that the catalytically active species switches from a CuI species for 1 to a Cu0 species for 4. This work is thus significant to present mechanism-controllable HER via electronic tuning of catalysts.

6.
Sci Total Environ ; 920: 170955, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38354805

ABSTRACT

Examining the rationality of zoning designations and management measures in the initial establishment of national parks in China is of great significance for supporting decision-making regarding habitat conservation. There exists a research gap in exploring the threshold effects of both environmental and human-related factors on habitat distribution in the context of national parks. However, it may be a challenge because of the limited species distribution data. Our study aims to put forward an analytical framework that integrates species distribution models (SDMs) with interpretable machine learning methods. A case study was performed in the Sichuan region of the Giant Panda National Park (GPNP). We constructed a SDM based on the Random Forest algorithm and made use of accessible remote sensing and big data to predict the distribution of giant panda habitat (GPH) in 2020. Interpretable machine learning methods, namely Partial dependence plots (PDPs) and SHapley Additive exPlanations (SHAP), were utilized to uncover the underlying mechanisms of environmental and anthropogenic variables influencing the GPH distribution. Through GIS overlay analysis, areas where conflicts between human settlements, transportation infrastructure, and GPH exist were identified. Our findings indicated a potential 28.44 % decrease in GPH from 2014 to 2020. Environmental factors such as temperature, topography, and vegetation type, as well as anthropogenic factors including distance to built-up areas and transportation infrastructure, notably distance to national roads, provincial roads and city arterial roads, influenced the GPH distribution with threshold effects significantly. The overlay analysis revealed escalated conflicts between human settlements, transportation infrastructure, and GPH in 2020 compared to 2014. Currently, the Sichuan region of the GPNP implements two zones: a core protection zone and a general control zone, covering 63.71 % of the GPH, while 36.29 % remains outside the management scope. Drawing from the analysis above, this study provided suggestions for the adjustment of zoning designations and management measures in the GPNP.


Subject(s)
Conservation of Natural Resources , Ursidae , Animals , Humans , Conservation of Natural Resources/methods , Parks, Recreational , Ecosystem , China
7.
J Hazard Mater ; 466: 133632, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38309164

ABSTRACT

Due to the capacity to offer abundant catalytic sites within porous solids featuring high surface areas, metal-organic frameworks (MOFs) and their derivatives have garnered considerable attention as prospective catalysts in environmental catalysis. To promote the industrial application of MOFs, there is an urgent need for an effective and environmental-friendly preparation approach. Breaking through the limitation of the traditional two-step preparation method that Pd was introduced to the already prepared Ce-BTC (Pd/Ce-BTC, BTC = 1, 3, 5 benzenetricarboxylate), in this work, we present a novel one-pot solvothermal method for synthesizing the Pd material supported by Ce-BTC (Pd@Ce-BTC). After pyrolysis in N2 flow or air flow, Pd-CeO2 catalysts derived from Pd@Ce-BTC exhibited much higher CO oxidation activity than those from Pd/Ce-BTC. Moreover, Pd/Ce-BTC and Pd@Ce-BTC pyrolyzed in N2 flow (Pd/Ce-BTC-N and Pd@Ce-BTC-N) could better catalyze the oxidation of CO than Pd/Ce-BTC and Pd@Ce-BTC pyrolyzed in air flow (Pd/Ce-BTC-A and Pd@Ce-BTC-A). Further characterizations revealed that the abundant surface Ce3+ species, rich surface adsorbed oxygen species and superior redox properties were the main reasons for the superior CO oxidation activity of Pd@Ce-BTC-N.

8.
Sci Total Environ ; 917: 170287, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38266728

ABSTRACT

Wet scavenging was critical in the atmospheric transport of 137Cs aerosols following the Fukushima accident. The aerosol size diversity and related microphysical processes produce complex behaviors during wet scavenging. Such behaviors are difficult to investigate using traditional simplified size distributions, resulting in inaccurate modeling. This study establishes an improved size-resolved wet scavenging model that considers the activation process. Using this model, five monodisperse simulations with five representative observed diameters with realistic solubility setting are performed to investigate the spatiotemporal wet scavenging behaviors of 137Cs aerosols. One polydisperse simulation with an empirical size distribution is also validated against the observation. The results reveal that 137Cs aerosols with diameters of 0.6 and 2.0 µm are mainly subject to below-cloud scavenging, which makes a significant contribution to low-deposition areas (<300 kBq/m2). For 137Cs aerosols with diameters of 6.4, 15, and 30 µm, in-cloud scavenging dominates, and the resulting depositions make significant contributions in high-deposition areas. The polydisperse results satisfy the criteria for good performance and better agree with the size, and deposition observations than the five monodisperse simulations, whereas for the concentration, the results show a similar RANK2 with the best mono1 and mono2 cases and reach the satisfactory criteria. These findings reveal the complex behavior and wet scavenging process of multi-mode 137Cs aerosols, improving our understanding and modeling.

9.
Ecol Evol ; 14(1): e10853, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38259957

ABSTRACT

The invasion of alien plant species threatens the composition and diversity of native communities. However, the invasiveness of alien plants and the resilience of native communities are dependent on the interactions between biotic and abiotic factors, such as natural enemies and nutrient availability. In our study, we simulated the invasion of nine invasive plant species into native plant communities using two levels of nutrient availability and suppression of natural enemies. We evaluated the effect of biotic and abiotic factors on the response of alien target species and the resistance of native communities to invasion. The results showed that the presence of enemies (enemy release) increased the biomass proportion of alien plants while decreasing that of native communities in the absence of nutrient addition. Furthermore, we also found that the negative effect of enemy suppression on the evenness of the native community and the root-to-shoot ratio of alien target species was greatest under nutrient addition. Therefore, nutrient-poor and natural enemies might promote the invasive success of alien species in native communities, whereas nutrient addition and enemy suppression can better enhance the resistance of native plant communities to invasion.

10.
J Environ Radioact ; 272: 107363, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38160503

ABSTRACT

Release rate estimation is a vital means of revealing the emission process of radionuclides and assessing the environmental consequences in an emergency. Inverse modeling is widely used in emergency cases, but is vulnerable to plume biases in atmospheric dispersion modeling. One promising solution is a model called "Simultaneously Estimates the Release rate And Corrects both the plume range and Transport pattern" (SERACT). This study investigates the feasibility and behavior of SERACT based on four wind tunnel experiments replicating complex dispersion scenarios with both dense buildings and heterogeneous topography. SERACT's performance is compared with that of Tikhonov-regularized inversion and its predecessor. The results demonstrate that SERACT successfully corrects the modeled plume biases and simultaneously improves the release rate estimations in all four complex local-scale scenarios. The release rates retrieved by SERACT provide better agreement with the true release rates than those given by the other methods for all scenarios, with an average deviation of only 5.83%. After correction, the simulated plume reproduces the concentrations at all sites and achieves the best Pearson correlation coefficient (1.00) and fraction of simulations within a factor of 2 of the measurements (1.00); these values are 7.33 and 2.09 times higher, respectively, than those of simulations using release rates obtained using Tikhonov-regularized inversion.


Subject(s)
Air Pollutants, Radioactive , Radiation Monitoring , Models, Theoretical , Radiation Monitoring/methods , Air Pollutants, Radioactive/analysis , Radioisotopes
11.
Front Plant Sci ; 14: 1275141, 2023.
Article in English | MEDLINE | ID: mdl-38023893

ABSTRACT

Introduction: Climate change and mono-afforestation or mono-reforestation have continuously caused a decline in biodiversity and ecosystem services on forest plantations. Key plant functional traits in forests or plantations may affect ecosystem functions after forest management practices. Plant clonality, a key functional trait, frequently links to biodiversity and ecosystem functions and affects the biodiversity-ecosystem functioning relationship. However, little is known about how plant clonality affects ecosystem functions and services of plantations after forest management. Methods: We conducted a field experiment to discuss the diversity and proportion of clonal plants, plant diversity of the communities, and ecosystem service functions and their relationships under 10 years of close-to-nature (CTN) management, artificial gap management, and control (i.e., without management) in the three stages of C. Lanceolata plantations. Results: Our results showed that CTN and gap management modes significantly facilitated diversity of clonal plants, plant diversity of the communities, and parameters of ecosystem service functions in C. lanceolata plantations. Moreover, CTN management promoted plant community diversity, soil water conservation, and carbon storage the most in the earlier stand stages. Diversity of clonal plants was significantly positively correlated with ecosystem service functions after forest management. Structural equation modeling analysis indicated that forest gap or CTN management indirectly positively affected ecosystem service functions through increasing diversity of clonal woody plants and plant diversity of the communities. Conclusion: Our results indicate a highly positive effect of gap or CTN management on diversity and proportion of clonal plants and on plant diversity of the communities, which link to improvements in ecosystem service functions (i.e., water and soil conservation and carbon storage). The link between forest management, diversity, and ecosystem functions suggests that key functional traits or plant functional groups should be considered to underline the mechanism of traits-ecosystem functioning relationships and the restoration of degraded plantations.

12.
Clin Immunol ; 257: 109811, 2023 12.
Article in English | MEDLINE | ID: mdl-37858752

ABSTRACT

BACKGROUND: To explore the specific marker of CD8+ T cell subsets which are closely related to the prognosis and immunotherapy of patients with colon cancer. METHODS: 18 kinds of immune cell expression profile data sets were obtained from GEO database. Compared with other immune cell types, the specific markers of CD8 (+) T cells (TI-CD8) in colorectal cancer were screened. Regression analyses were used to further screen prognostic related genes and construct a prognostic evaluation model. The patients were stratified and analyzed according to the risk scores, KRAS mutation status, stage, lymphatic infiltration and other indicators. The landscape of infiltration level, mutation and copy number variation of immune subsets in high and low TI-CD8Sig score groups were compared and analyzed. The difference of drug response between high and low TI-CD8Sig score groups was analyzed. Differential expression of the model genes was verified by the HPA database. RESULTS: Six prognostic-related CD8T cell-specific gene targets were further screened, and the prognostic evaluation model was constructed. The AUC value of the model is >0.75. FAT3 and UNC13C showed a high mutation state in the low-risk group, while USH2A, MUC5B et al. specifically showed a high mutation state in the high-risk group. Compared with the low-risk group, the high-risk group had lower effective rate of drug response. The expression of PD-1 gene was positively correlated with the level of TI-CD8Sig score. CONCLUSION: The risk assessment model based on CD8T cell-specific marker genes can effectively predict the prognosis and the drug response of patients with CRC.


Subject(s)
Colonic Neoplasms , DNA Copy Number Variations , Humans , Colonic Neoplasms/genetics , Colonic Neoplasms/therapy , CD8-Positive T-Lymphocytes , Prognosis , Immunotherapy , Machine Learning , Tumor Microenvironment
13.
Front Nutr ; 10: 1242157, 2023.
Article in English | MEDLINE | ID: mdl-37693249

ABSTRACT

Objectives: Obesity is often associated with glucolipid and/or energy metabolism disorders. Ascophyllum nodosum extract (seaweed extract, SE) and Camellia sinensis-leaf extract (tea extract, TE) have been reported to promote positive metabolic effects through different mechanisms. We investigated the effects of SE and TE on metabolic homeostasis in diet-induced obese mice and discussed their functional characteristics. Methods: Male C57BL/6J mice fed with high-fat diets for 8 weeks were established as obese models and subsequently divided into different intervention groups, followed by SE, TE, and their joint interventions for 10 weeks. Body weight and food intake were monitored. Fasting glucose and oral glucose tolerance tests were interspersed during the experiment. After the intervention, the effects on obesity control were assessed based on body composition, liver pathology section, blood lipids and glucose, respiratory exchange ratio (RER), energy expenditure (EE1, EE2, and EE3), inflammatory factors, lipid anabolism enzymes, and gut flora of the obese mice. Results: After continuous gavage intervention, the mice in the intervention groups exhibited lower body weight (lower ~4.93 g, vs. HFD 38.02 g), peri-testicular fat masses (lower ~0.61 g, vs. HFD 1.92 g), and perirenal fat masses (lower ~0.21 g, vs. HFD mice 0.70 g). All interventions prevented diet-induced increases in plasma levels of glucose, adiponectin, leptin, and the inflammatory factors IL-1ß and TNF-α. The RER was modified by the interventions, while the rhythm of the RER was not. Blood lipids (total cholesterol, triglycerides, and LDL) decreased and were associated with lower lipid anabolism enzymes. In addition, the SE and TE interventions altered the structure and abundance of specific flora. Different interventions inhibited the growth of different genera positively associated with obesity (Escherichia-Shigella, Helicobacter, etc.) and promoted the growth of Akkermansia and Bacteroides, thus affecting the chronic inflammatory state. Conclusion: SE and TE both have synergistic effects on weight control and glucolipid metabolism regulation by improving insulin sensitivity and reducing lipid synthesis-related enzyme expression, whereas the combination of SE and TE (3:1) has a better effect on regulating energy metabolism and inhibiting chronic inflammation.

14.
Chem Commun (Camb) ; 59(72): 10777-10780, 2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37593777

ABSTRACT

A newly designed copper complex of 5,15-bis(pentafluorophenyl)-10,20-bis(o-carborane)porphyrin (1) was synthesized and tested for the electrocatalytic hydrogen evolution reaction (HER). In acetonitrile, 1 was much more efficient than Cu 5,15-bis(pentafluorophenyl)-10,20-diphenylporphyrin (2) for electrocatalytic HER by shifting the catalytic wave to the anodic direction by 190 mV. In aqueous media, 1 also outperformed 2 by achieving higher current densities under smaller overpotentials. This enhancement was attributed to the aromatic and the strong electron-withdrawing properties of o-carborane groups. This work is significant to address the crucial effects of meso-(o-carborane) substituents of metal porphyrins on boosting the electrocatalytic HER.

15.
Genes Dis ; 10(5): 2109-2124, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37492736

ABSTRACT

This study aims to identify the inflammatory factor-related genes which help to predict the prognosis of patients with colorectal cancer. GSEA (Gene Set Enrichment Analysis) was used to acquire inflammation-related genes and the corresponding expression information was collected from TCGA database to determine the DEGs (differentially-expressed genes) in CRC patients. We conducted enrichment analysis and PPI (protein-protein interaction) of these DEGs. Besides, key genes that are both differentially-expressed and prognosis-related were screened out, which were used to establish the prognostic model. We obtained 79 DEGs and 19 prognostic genes, 10 prognostic-related differential genes were eventually screened. These genes were used to construct the prognostic model. We also identified that the immune infiltration score of macrophages between different risk groups was significantly different and similar distinction was witnessed in immune function score of APC (antigen-presenting cell) co-stimulation and type I IFN (interferon) response.

16.
J Environ Radioact ; 265: 107212, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37307754

ABSTRACT

Modeling of local atmospheric radionuclide transport is essential for nuclear emergency response. However, very few studies of the Fukushima Dai-ichi nuclear power plant (FDNPP) accident have focused on this topic because of the complex meteorology and the cross-scale transport behaviors from the site to 20 km of the FDNPP. In this study, both the local meteorology and transport behaviors were investigated at high resolution (200 m) using ensembles of different meteorology and models. Four wind fields calculated from onsite observations and three regional-scale meteorological fields (i.e., the 1-km ECMWF, 3-km and 1-km NHM-LETKF), and two transport models: the RIMPUFF Lagrangian puff model and the SPRAY particle model were considered and combined with each other. These eight simulations and their ensemble mean were analyzed based on onsite observations of wind and gamma dose rates, and local-scale observations of 137Cs concentration. Results revealed that at the site, the Onsite wind field which captured the frequently changing wind, best reproduced the onsite gamma dose rates with the grid resolution of 200 m. At the local scale (up to 20 km), the observations present a smoother temporal change. The wind fields assimilated with Japanese domestic observations presented advantageous performance, and the 1-km NHM-LETKF achieved the best score of the factor of 5 metric of 0.49 for the simulated 137Cs concentration. The SPRAY coupled with the three-dimensional (3D) convolution method and RIMPUFF showed better performance in simulating the onsite gamma dose rate and the local-scale concentration, respectively. The ensemble mean achieved robust metrics, better simulated the baseline of onsite gamma dose rates, and reproduced more peaks of local-scale concentration at the expense of peak value deviation.


Subject(s)
Fukushima Nuclear Accident , Radiation Monitoring , Radiation Monitoring/methods , Cesium Radioisotopes/analysis , Wind , Japan
17.
Food Sci Nutr ; 11(5): 2356-2371, 2023 May.
Article in English | MEDLINE | ID: mdl-37181308

ABSTRACT

Herein, we explored the effects of Poria cocos extract, protein powder mixture, and their combined intervention on weight loss in high-fat diet (HFD)-induced obese mice. Male C57BL/6J mice were selected and fed a HFD for 8 weeks; obese mice that were successfully modeled were divided into modeling and five intervention groups, and given the corresponding treatment for 10 weeks. Body weight, fat, and muscle tissue, blood glucose, lipids, inflammatory factors, and other glucose and lipid metabolism-related indicators were measured to evaluate the effect of P. cocos and protein powder intervention on weight loss in obese mice. The body weight of the intervention group was reduced compared with the HFD group. Fat content of mice in F3PM group decreased significantly (p < .05). Levels of blood glucose, lipids, adiponectin, leptin, and inflammatory factors, including interleukin-1 ß and tumor necrosis factor- α showed improvement. Lipoprotein lipase (lower about 2.97 pg/ml, vs. HFD mice 10.65 mmoL/ml) and sterol regulatory element-binding transcription factor (lower about 1413.63 pg/ml, vs. HFD mice 3915.33 pg/ml) levels in liver tissue were decreased. The respiratory exchange rate (RER) of mice in the HFD and subject intervention groups had no circadian rhythm and was maintained at approximately 0.80. The protein powder mixture (PM) group had the lowest RER (p < .05), the P. cocos extract (FL) and F1PM groups had similar RER to the HFD group (p < .05), and the F2PM group had a higher RER than the HFD group (p < .05). And food intake and energy metabolism returned to circadian rhythm, with an increase in the dose of P. cocos extract, the feeding rhythms of F1PM, F2PM, and F3PM were closer to that of the normal diet (ND) group. Feeding intervention with P. cocos and protein powder improved fat distribution, glucolipid metabolism, and energy metabolism, with the combination of F3PM showing more diverse benefits.

18.
Thromb J ; 21(1): 31, 2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36941692

ABSTRACT

BACKGROUND: Platelet indices are blood-based parameters reflecting the activation of platelets. Previous studies have identified an association between platelet indices and blood pressure (BP). However, causal inferences are prone to bias by confounding effects and reverse causation. We performed a Mendelian randomization (MR) study to compare the causal roles between genetically determined platelet indices and BP levels. METHODS: Single-nucleotide polymorphisms (SNPs) associated with platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), and BP at the level of genome-wide significance (p < 5 × 10- 8) in the UK Biobank were used as instrumental variables. In bidirectional univariable MR analyses, inverse variance-weighted (IVW), MR‒Egger, and weighted median methods were used to obtain estimates for individual causal power. In addition, heterogeneity and sensitivity analyses were performed to examine the pleiotropy of effect estimates. Finally, multivariable MR analyses were undertaken to disentangle the comparative effects of four platelet indices on BP. RESULTS: In the univariable MR analyses, increased levels of PLT and PCT were associated with higher BP, and PDW was associated with higher DBP alone. In the reverse direction, SBP had a minor influence on PLT and PCT. In multivariable MR analysis, PDW and PLT revealed an independent effect, whereas the association for PCT and MPV was insignificant after colinear correction. CONCLUSION: These findings suggest that platelets and BP may affect each other. PDW and PLT are independent platelet indices influencing BP. Increased platelet activation and aggregation may be involved in the pathogenesis of hypertension, which may provide insights into evaluating thromboembolic events in people with high BP. The necessity of initiating antiplatelet therapy among hypertension groups needs further investigation.

19.
Sci Total Environ ; 872: 162165, 2023 May 10.
Article in English | MEDLINE | ID: mdl-36775160

ABSTRACT

Wet deposition remains an important source of uncertainty in modeling of the atmospheric transport of 137Cs following the Fukushima Daiichi Nuclear Power Plant accident. Its behavior is often difficult to investigate owing to the limited resolution of meteorological field data and inconsistent model implementations. This study investigated the detailed behavior of 25 combinations of in- and below-cloud wet scavenging models using high-resolution (1 km × 1 km) meteorological input. These combinations were all implemented in the Weather Research and Forecasting-Chemistry model, thereby enabling consistent evaluation. The 1-km-resolution simulations were compared with simulations obtained previously using 3-km-resolution meteorological field data. Results revealed that rainfall of <1 mm/h is critical for simulation accuracy. The 1-km results revealed better representation of rainfall than that revealed by the 3-km results, but with spatiotemporal variability in accuracy. Owing to their sensitivity to rainfall, single-parameter wet deposition models showed improvements in performance in the 1-km simulations relative to that in the 3-km simulations. The multiparameter models showed more robust performance in terms of both simulations, and the Roselle-Mircea model presented the best performance among the 25 models considered. Wind transport showed substantial influence on the removal of atmospheric 137Cs, and it was nonnegligible even during periods in which wet deposition was dominant. The 1-km-resolution simulations effectively reproduced local-scale 137Cs concentrations but with deviations in timing, mainly because of biased wind direction. These findings indicate the necessity for a refined wind and dispersion model for local-scale simulation of 137Cs concentration.

20.
Chemosphere ; 315: 137677, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36608889

ABSTRACT

As one of the major pollutants in the environment, chromium (Cr), a heavy metal, poses a serious threat to urban green spaces and human life and health. Cosmos bipinnatus is considered a potential accumulator of Cr, and the differences in cellular Cr distribution and compartmentalization may uncover the mechanisms involved in its tolerance to Cr. To elucidate the effects of Cr stress on C. bipinnatus and determine the mechanism of Cr tolerance in C. bipinnatus, we investigated the physiological indicators, subcellular distribution and chemical forms, cell wall fractions and their Cr contents, uronic acid content in the cell wall fractions, and Fourier transform infrared spectroscopy (FTIR) of the cell wall. The results showed that the antioxidant enzyme activities in C. bipinnatus under Cr stress and most of the Cr were fixed in the cell wall. Notably, changes in the content of pectin fractions in the cell wall affected the accumulation of Cr in the cell wall of C. bipinnatus and the stability of negatively charged groups. In addition, the carboxyl and hydroxyl groups played a role in fixing metal in various parts of the C. bipinnatus cell wall.


Subject(s)
Asteraceae , Chromium , Humans , Chromium/toxicity , Antioxidants , Cell Wall
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