Response of electron transfer capacity of humic substances to soil microenvironment.

The humic substances (HS) - mediated electron transfer process is of great significance to the reduction and degradation of pollutants and the improvement of soil quality. Different soil conditions lead to different characteristics of HS, resulting in differences in the electron transfer capacity (ETC) of HS. It is unclear how the environmental conditions in soil affect the ETC by affecting on HS. In this study, the response relationship of soil microenvironment, HS and ETC has been studied. The results show that the ETC follows the descending order of: Langshan > Nanchang > Anqing > Beijing > Guilin. There were significant differences in ETC in soil HS in different regions. There were significant differences in electron-donating capacity (EDC) in soil HS in different regions and depths. EDC in soil was higher than electron-accepting capacity (EAC), and on average, are 22.4 times higher than the EAC. The HS components of soils in different regions are different. The most significant differences were in tyrosine-like substances and soluble microbial by-products (SMPs). The five components of the soil HS from Langshan were the most different from those in other regions. There were differences in SMPs and humic-like substances in soils of different depths in Anqing and Guilin. ETC can be affected by the composition of HS components in different regions. The composition of HS at different soil depths in the same regions had little effect on ETC. SMPs can promote ETC and EDC, and tyrosine-like substance can promote EDC. Moisture content, pH and TOC are the main factors affecting the composition of HS components. This results can provide a research basis for the sustainable and safe utilization of agricultural soil.

Distribution, Chemotherapy Use, and Outcome of the 21-Gene Recurrence Score Between Chinese and White breast Cancer in the United States.

PURPOSE: To compare the distribution, chemotherapy-decision making, and prognosis of the 21-gene recurrence score (RS) between Chinese breast cancer (BC) in the United States and White American (WA) BC. METHODS: We identified early-stage and estrogen receptor-positive BC patients diagnosed between 2004 and 2015. Multivariate logistic regression, Kaplan-Meier analysis, and multivariate Cox proportional hazards models were used for statistical analyses. RESULTS: A total of 67,486 patients were identified, including 66,215 (98.1%) WA patients and 1271 (1.9%) Chinese patients. Regarding the RS, 38,894 (57.6%) had low RS, 23,882 (35.4%) had intermediate RS, and 4710 (7.0%) had high RS. A similar distribution of RS was found between WA and Chinese BC (P = .280). The race was not the predictor associated with high RS. Similar trends of chemotherapy use were found in Chinese and WA BC. In WA BC, there were 4.1%, 31.5%, and 72.2% of patients receiving chemotherapy in low, intermediate, and high RS cohorts, respectively (P < .001). The proportion of chemotherapy use was 6.8%, 30.9%, and 74.0% in Chinese BC with low, intermediate, and high RS cohorts, respectively (P < 0.001). The multivariate prognostic analyses indicated that a higher RS was independently associated with an inferior breast cancer-specific survival. Similar trends were found among those with Chinese and WA BC. CONCLUSION: Our results demonstrate similar distribution, chemotherapy use, and outcome of the 21-gene RS between Chinese and WA BC in the United States.

The Physical Fitness Level of College Students Before and After Web-Based Physical Education During the COVID-19 Pandemic.

Background: The COVID-19 pandemic has been an emergency worldwide. Web-based physical education is a choice for college students to keep on their study. The aim of this study was to compare the data of physical fitness of college students before and after web-based physical education. Methods: All the students of 2018 and 2019 in Wuhan University of Technology who had taken the web-based physical education class in 2020 were included in this study. The records of annual physical fitness tests of all the subjects in 2019 and 2020 which were carried out in September were reviewed, including weight, height, body mass index (BMI), vital capacity (VC), 50-m dash, sit-and-reach, standing long jump, male-specific pull-ups and 1,000-m race, and female-specific sit-ups and 800-m race. Results: There were 24,112 male and 9,690 female records of physical fitness tests included in our study. The results of 11,219 male and 4,651 female students who completed both physical fitness tests in 2019 and 2020 were employed for Wilcoxon signed-rank test. Declined performance was observed on male 50-m dash by 0.1 s, male 1,000-m race by 14 s, and female 800-m race by 11 s. Notably, the percentage of male obesity, based on BMI, rose from 10.6 to 15.2% and 17.1 to 21.8% for male overweight; correspondingly, the percentage of male normal weight declined from 55.9 to 51.9% and 16.4 to 11.1% for male thinness. The trend of increasing BMI in males should be paid attention to. Improved results on vital capacity, sit-and-reach, standing long jump for both males and females, female 50-m dash, female sit-ups, and male pull-ups were observed in 2020. All the results of physical fitness tests were significantly different between 2019 and 2020 (p < 0.01) by Wilcoxon signed-rank test. Conclusions: The changes of physical fitness tests before and after web-based physical education suggested that the focus should be placed on improvement for running tests through appropriate alternatives, such as fast running in place and shuttle run. In addition, the simple, convenient, and practical sport that require available equipment and little field should be considered for web-based physical education.

[Spatial-Temporal Trends and Pollution Source Analysis for Heavy Metal Contamination of Cultivated Soils in Five Major Grain Producing Regions of China].

Heavy metal pollution of farmland soils in China has been identified as a threat to ecosystem safety and human health. A total of 3006 soil samples were analyzed from arable lands in five grain producing regions of China, which included data from published studies from 2000 up to now. An additional 656 historical samples were derived from the 1980s by a digitizing grained point sites map (Cd, Pb, As, Ni, Cu, Zn, Cr, and Hg) from the PRC Atlas of Soil Environmental Background Values. A GIS-based approach and single factor index method were employed to identify the current status and spatial distribution of heavy metal (Cd, Pb, As, Ni, Cu, Zn, Cr, and Hg) contamination in agricultural soils, and these were then compared with historical data to explore contamination trends over time. Then, based on the Igeo method and the effects of the surrounding environment on contamination rates, pollution sources were analyzed. Results showed that 21.49% of the agricultural soil samples exceeded the environmental quality standard set by the Ministry of Environmental Protection. The proportions of slight, moderate, and severe pollution were 13.97%, 2.50%, and 5.02%, respectively. Pollution is more extensive in the south compared with the north. Exceedance percentages in the Sichuan Basin (SC), Yangtze River Middle Plain and Jianghuai Plain (CJ), Huang-Huai-Hai Plain (HHH), Songnen Plain (SN), and Sanjiang Plain (SJ), were 43.55%, 30.64%, 12.22%, 9.35%, and 1.67%, respectively. The main pollutants were Cd, Ni, Cu, Zn, and Hg, with exceedance percentages of 17.39%, 8.41%, 4.04%, 2.84%, and 2.56%, respectively. Since the 1980s, heavy metal pollution has increased by 14.91%. The proportion of Cd, Ni, Cu, Zn, and Hg increased by 16.07%, 4.56%, 3.68%, 2.24%, and 1.96%, respectively. Except for SJ, exceedance percentages in cultivated land increased significantly, while the exceedance percentages of Cd, Ni, and Cu in the southern areas were higher than for the northern areas-although the growth rate of Hg and Cr in the south was lower than that in the north. The main sources of Cd and Hg were anthropogenic pollution, while the other six heavy metals were from predominantly natural sources. However, about 20.00% of Pb, Zn, and Cu were affected by anthropogenic activities. Mining, industry, and sewage water were the main sources of pollution. In addition to the larger impact of sewage irrigation in the north, other sources of pollution showed greater influence in the south. Mining mainly caused pollution by Cd, Hg, Ni, Cr, and Cu, while excessive levels of Cd, Ni, Cu, Zn, and Hg was the signature of industrial pollution. Irrigation with sewage effluent causes excessive Cd, Ni, and Zn. Results from this study provide valuable information for agricultural soil management and food safety in China.

Investigating the composition characteristics of dissolved and particulate/colloidal organic matter in effluent-dominated stream using fluorescence spectroscopy combined with multivariable analysis.

Fluorescence excitation-emission matrix (EEM) spectroscopy combined with principal component analysis (PCA) and parallel factor analysis (PARAFAC) were used to investigate the compositional characteristics of dissolved and particulate/colloidal organic matter and its correlations with nitrogen, phosphorus, and heavy metals in an effluent-dominated stream, Northern China. The results showed that dissolved organic matter (DOM) was comprised of fulvic-like, humic-like, and protein-like components in the water samples, and fulvic-like substances were the main fraction of DOM among them. Particulate/colloidal organic matter (PcOM) consisted of fulvic-like and protein-like matter. Fulvic-like substances existed in the larger molecular form in PcOM, and they comprised a large amount of nitrogen and polar functional groups. On the other hand, protein-like components in PcOM were low in benzene ring and bound to heavy metals. It could be concluded that nitrogen, phosphorus, and heavy metals in effluent had an effect on the compositional characteristics of natural DOM and PcOM, which may deepen our understanding about the environmental behaviors of organic matter in effluent.

[Complexation Between Copper(â ¡) and Colored Dissolved Organic Matter from Municipal Solid Waste Landfill].

In order to elucidate the evolution mechanism of heavy metal species in landfill cells, three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM), fluorescence quenching titration and parallel factor analysis (PARAFAC) were employed to study the complexation process between Cu(Ⅱ) and colored dissolved organic matter (CDOM) from landfill with different ages. The experimental results indicated that the landfilled CDOM comprised protein-like, humic-like and fuvic-like matter. The relative content of protein-like matter decreased during the landfill process, whereas the humic-like and fuvic-like matter increased during the process. The range of the conditional stability constants and the percentage of fluorophores participated the complextion between Cu(Ⅱ) and protein-like matter with different ages were 4.00-5.75 and 22.78%-95.30%, respectively. Those parameters changed slightly for humic-like matter with different ages, which ranged from 4.71 to 5.54 and from 42.35% to 61.46%, respectively. As regard to fulvic-like matter, those parameters were 4.44-5.25 and 46.14%-57.22%, respectively. The complexation ability of humic-like substances with Cu(Ⅱ) decreased during the landfill process, though the percentage of fluorophores participated the complexation increased. The complexation ability of humic-like substances with Cu(Ⅱ) was stronger than that of fulvic-like matter, though the percentage of fluorophores participated the complexation in humic-like matter was low compared with fulvic-like matter.

Insight into the composition and degradation potential of dissolved organic matter with different hydrophobicity in landfill leachates.

Dissolved organic matter (DOM) isolated from the leachates with different landfill ages was fractionated into hydrophobic acid (HOA), hydrophobic neutral (HON), hydrophobic base (HOB) fractions and hydrophilic matter (HIM) based on hydrophobicity, and the composition and degradation potential of the bulk DOM and its fractions were investigated by excitation-emission matrix fluorescence spectra coupled with parallel factor analysis. Results showed that the bulk DOM comprised fulvic-, humic-, tryptophan- and tyrosine-like substances, as well as component C1, whose composition and origin was unidentified. Landfill process increased the content of component C1, fulvic- and humic-like matter. The HON fractions comprised primarily component C1 and tyrosine-like matter. The HOA, HOB and HIM fractions isolated from the young leachates consisted mainly of tryptophan- and tyrosine-like substances. As to the intermediate and old leachates, the HOA and HOB fractions comprised mainly component C1, while the HIM comprised mainly fulvic-like matter. The HIM showed the most resistant against biodegradation among the four fractions, and was the main component of leachate treatment. Advanced oxidation and/or membrane treatment are recommended to remove the HIM fraction due to its hydrophilic and stable characteristics.

[Composition and Evolution Characteristics of Dissolved Organic Matter During Composting Process].

According to the fraction method presented by Leenheer, dissolved organic matter (DOM) extracted from chicken manure with different composting time was fractionated into five groups [i. e., hydrophobic acid (HOA), hydrophobic base (HOB), hydrophobic neutral (HON) fractions, acid-insoluble (AIM) and hydrophilic matter (HIM)] using the XAD-8 resin based on its polarity and electric charge characteristics. The composition and structures of these fractions were investigated by elemental analysis, FTIR and 1H-NMR spectra. The results showed that the HIM and HOA fractions accounted for 32%-44% and 35%-47% of DOM, respectively, during the composting process, while the sum of the fractions HOB, AIM and HON was responsible for less than 25% of DOM. The HIM content decreased while the hydrophobic component increased after composting. The elemental analysis indicated that, during the composting process, the N, C, S content of all five fractions increased, the H/C ratio decreased, but the humification degree increased; The result from 1H-NMR analysis showed that the HIM had low alkyl chain, short branched chain, high branches and carbohydrate structure, which was opposed to the HON fraction. The composition of AIM was similar to that of humic acids, while the HOB was rich in nitrogen-containing compounds. The result from the FTIR analysis showed that the HOA and HOB fractions were rich in abundant carboxyl, ester group and hydroxyl functional group. Besides the above functional groups, the AIM and HIM were rich in benzene groups. The HON fraction was rich in aliphatic functional group except for the abovementioned functional groups. The aliphatic functional group was degraded and the benzene functional group after composting.

[Vertical Distribution Characteristics of Dissolved Organic Matter in Groundwater and Its Cause].

Dissolved organic matter (DOM) can change the species, migration and transformation of foreign pollutants in groundwater, and the investigations of its composition and distribution characteristics play a role in environment protection. The groundwater DOMs were obtained at the depths of 1.2, 1.5 and 1.8 m, and its origin, composition, concentration, distribution characteristics and influencing factors were studied using UV-Vis and fluorescence spectra combined with parallel factor analysis and principle components analysis. The results showed that, DOM in the groundwater originated from both terrigenous input and microbial activities, and was comprised of humic-like matter, heterogeneous component, and protein-like matter. Humic-like matter and heterogeneous components showed a high concentration at 1.5 m and a low one at 1.2 m, whereas the protein-like matter exhibited a low concentration at 1.5 m and a high one at 1.2 m. The groundwater DOM at 1.5 m exhibited the highest aromaticity, humification, molecular weight and polar functional group content, while that at 1.2 m depth showed the lowest aromaticity, humification, molecular weight and polar functional group content. The vertical distribution of DOM in groundwater was related to aromaticity, humification, molecular weight and polar functional group, and the DOM with high aromaticity, humification, molecular weight and polar functional group resisted to biodegradation, and could easily enter into the bottom layer groundwater.

Insight into the composition and evolution of compost-derived dissolved organic matter using high-performance liquid chromatography combined with Fourier transform infrared and nuclear magnetic resonance spectra.

Size exclusion chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) were combined with Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance (NMR) based on two dimensional (2D) hetero-spectral correlation spectra techniques to fractionate compost-derived dissolved organic matter (DOM) and determine how size- and hydrophobicity-distinguished fractions differ in the composition and evolution. The results showed that the compost-derived DOM was comprised of protein- and humic-like species. The low apparent molecule weight (AMW) protein-like components were enriched in C-C=H3 and N-C=O, and showed more bioreactivity compared with the high AMW counterpart. The hydrophobic and hydrophilic protein-like components both consisted of CCH3 and N-C=O. However, the relatively hydrophilic protein-like components were more easily consumed. As to the humic-like species, the relatively hydrophilic components were slightly larger than the relatively hydrophobic ones. The high AMW and relatively hydrophilic humic-like components were high in C-H, OCH3, N-C=O, N-H, COO, O-H and aromatic C. The low AMW and relatively hydrophobic humic-like components were enriched in CCH3 and N-C=O, and were easily biodegraded during composting. 2D hetero-spectral correlation spectra techniques enhance the characterization of DOM and provide a promising way to elucidate the environmental behaviors of DOM.

Serine Proteinase Inhibitor SERPINA3K Suppresses Corneal Neovascularization via Inhibiting Wnt Signaling and VEGF.

Purpose: To evaluate the anti-neovascularization effects and investigate the possible mechanisms of SERPINA3K, a member of serine proteinase inhibitor family, using a specific rat model of suture-induced corneal neovascularization. Methods: A rat corneal suture model was set up and SERPINA3K was topically administered three times daily for 7 days. The clinical indications were evaluated on day 2, 5 and 7, including area of neovascularization and inflammation index. The eyeballs were collected after day 7 and the following examinations were performed: histological investigation, immunostaining, western blot and quantitative real-time polymerase chain reaction (PCR) assay. Wnt3a, a Wnt pathway ligand, was added to cultured Human Umbilical Vein Endothelial Cells (HUVEC), followed by detecting cell migration and western blot. Meanwhile, an in vitro VEGF165-stimulated HUVEC model was applied and the following measurements were conducted: cell proliferation, cell migration and tube formation. Results: SERPINA3K significantly suppressed corneal neovascularization and inhibited corneal inflammation. SERPINA3K downregulated the levels of ß-catenin, non-pi-ß-catenin and transcription factor 4 (TCF4), but upregulated the level of pi-ß-catenin of the corneas induced by suture. SERPINA3K also decreased the gene expression and protein level of VEGF. Meanwhile, induction of Wnt3a increased the cell migration, activated the Wnt signaling and upregulated VEGF in cultured HUVEC, which were antagonized by SERPINA3K. In addition, SERPINA3K significantly inhibited VEGF165-induced cell proliferation and migration of HUVEC, SERPINA3K also specifically suppressed the VEGF165-induced tube formation of HUVEC. Conclusions: SERPINA3K has therapeutic potential for corneal neovascularization. The underlying mechanism may be through inhibiting Wnt signaling pathway and VEGF.