[Release Mechanisms of Carbon Source and Dissolved Organic Matter of Six Agricultural Wastes in the Initial Stage].

As carbon sources for the denitrification process, agricultural wastes have some problems, such as excess release of organic carbon; unclear release characteristics of nitrogen, phosphorus, and colorimetric substances; and unclear components, release mechanisms, and potential effects of the released dissolved organic matter (DOM) in the start-up period. To resolve those problems, rice straw, wheat straw, corn stalk, corncob, soybean stalk, and soybean hull were selected as denitrification carbon sources to investigate the release mechanisms and potential influences of the organic matter, secondary pollutants, and DOM. The results showed that the six agricultural wastes could be used as the denitrification carbon source. The carbon content in the wheat straw was the highest and the secondary pollution risk from the corncob was the lowest. For the six carbon sources, the second-order kinetic equation and Ritger-Peppas equation were followed during the 1-120 h carbon release process. The fitting results demonstrated that corncob was more suitable for use as the denitrification carbon source because of its moderate cm value and longer t1/2 value, and the release mechanisms of the six types of carbon sources were mainly controlled by the diffusion process. The NH4+-N, TN, and TP contents in the immersion water of the rice straw were higher than those of the five other agricultural wastes, and there was heavy chromaticity in the immersion water of the wheat straw and corn stalk. The amounts of nitrogen, phosphorus, and chromatic substances released from the corncob were the lowest. The leachates of the corncob and soybean hull had higher biodegradability and lower risks of secondary pollution than those of the other sources. The aromaticity and molecular weight of DOM increased as the reaction time increased, and the humification of DOM was low. Five components were identified by PARAFAC. The main component was protein-like matter, which was mainly composed of tyrosine-like and tryptophan-like substances. There was less humic acid-like matter in the immersion water. The component characteristics of DOM might have had an adverse effect on the subsequent water treatment process. These results could provide theoretical support for the impact on effluent water quality and risk assessment when the agricultural wastes are used as an additional denitrification carbon source at the start-up stage.

miR-338-3p inhibits autophagy in a rat model of allergic rhinitis after PM2.5 exposure through AKT/mTOR signaling by targeting UBE2Q1.

Exposure to fine particulate matter (PM2.5) increases the incidence of allergic rhinitis (AR). microRNA (miRNA) can regulate cell proliferation, invasion and apoptosis. However, the mechanism of miR-338-3p in mediating PM2.5-induced autophagy in AR animal models remains unknown. To explore the mechanism of miR-338-3p in PM2.5-induced autophagy in AR, the human nasal epithelium cells and AR model exposed to PM2.5 were deployed. The results showed that miR-338-3p was down-regulated in both nasal mucosa of PM2.5-exacerbated AR rat models and PM2.5-treated RPMI-2650 cells. Forced expression of miR-338-3p could inhibit autophagy in vitro. miR-338-3p specifically bound to UBE2Q1 3'-untranslated region (3' UTR) and negatively regulated its expression. Overexpression of UBE2Q1 attenuated the inhibitory effects of miR-338-3p on PM2.5-induced autophagy of RPMI-2650 cells through AKT/mTOR pathway. Moreover, our in vivo study found that after administration of agomiR-338-3p in AR rats model, the expression of autophagy-related proteins decreased and nasal symptoms alleviated. In conclusion, this study revealed that miR-338-3p acts as an autophagy suppressor in PM2.5-exacerbated AR by directly targeting UBE2Q1 and affecting AKT/mTOR pathway.

Contribution of Vocabulary Knowledge to Reading Comprehension Among Chinese Students: A Meta-Analysis.

This study investigated the correlation between vocabulary knowledge and reading comprehension. To address the correlation picture under Chinese logographical scripts, the researchers investigated the potential explanation for the correlation via Reading Stage, Information Gap, Content-based Approach, and Cognition and Creativity Theory approaches. This study undertook a meta-analysis to synthesize 89 independent samples from primary school stage to Master's degree stage. Results showed the correlation picture as an inverted U-shape, supporting the idea that vocabulary knowledge contributed a large proportion of variance on text comprehension and might also support the independent hypothesis of the impact of vocabulary knowledge on reading comprehension. In each education stage, the correlation between vocabulary knowledge and reading comprehension was independent in that it did not interact with any significant moderators. This study informed that the vocabulary knowledge not only determined text comprehension progress through facial semantic meaning identification but also suggested that the coordinate development of vocabulary knowledge, grammatical knowledge, and inference would be better in complexity comprehension task performance.

[Nitrogen Removal in Low-C/N Rural Sewage Treatment by Anoxic/Oxic Biofilter Packed with New Types of Fillers].

When low-concentration rural sewage is treated biologically, the effluent total nitrogen (TN) concentration often does not meet the discharge limit because of its low carbon-to-nitrogen ratio (C/N). To solve this problem, a laboratory-scale anoxic/oxic (A/O) biofilter packed with Arundo donax and activated carbon as the anoxic and aerobic column fillers (No. 2) was operated for treatment of simulated rural sewage and advanced nitrogen removal, while an ordinary gravel-packing A/O biofilter (No. 1) was set up as the control group. The results were as follows. When the influent chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), and TN concentrations were (79.47±14.21), (34.49±2.08), and (34.73±3.87) mg·L-1, respectively, the No. 1 and No. 2 reactors achieved removal efficiencies of (88.00±7.00)% and (89.00±10.00)%, (90.00±2.00)% and (97.00±7.00)%, and (37±15)% and (68±7)%, respectively. The results revealed that using Arundo donax and activated carbon new fillers could significantly enhance NH4+-N and TN removal. High-throughput sequencing results indicated that the microorganisms involved in the nitrification process in the No. 1 reactor mainly belong to Proteobacteria, whereas those in the No. 2 reactor belong to Proteobacteria and Nitrospirae. In addition, the main denitrification bacterial phyla in the anoxic column of the No. 1 reactor were Chloroflexi, Proteobacteria, Bacteroidetes, and Planctomycetes, whereas those in the anoxic column of the No. 2 reactor were primarily Bacteroidetes, Proteobacteria, Firmicutes, and Patescibacteria. Quantitative real time polymerase chain reaction (qPCR) results showed that the microbial nitrification (amoA and Nitrospira 16S rDNA), denitrification (narG, nosZ, nirS, and nirK), and anaerobic ammonium oxidation functional genes (ANAMMOX) in the No. 2 reactor were significantly higher than those in the No. 1 reactor. All the genes, except for the narG and nosZ genes, had one to two orders of magnitude of improvement in the No. 2 reactor compared to those in the No. 1 reactor.

Longitudinal Effects of Mediums of Word Explanation on L2 Vocabulary Learning Strategies Among Chinese Grade-7 Students.

This longitudinal study investigated how different mediums of word explanation affected the use of English vocabulary strategies among Chinese Grade-7 students. 170 students were tested on their English receptive vocabulary size and vocabulary strategy application before and after an 8.33-month intervention. Students were divided into three experimental groups and one control group. The three experimental groups were provided with learning materials that explained the target vocabulary in three mediums, respectively: English-only, English-and-Chinese, and Chinese-only. Results showed that, after the intervention, receptive vocabulary size did not have any direct significant impact on vocabulary strategy development, whereas mediums of word explanation materials impacted students' application of vocabulary learning strategies (VLS) in different ways. Our findings showed that the English-only mediums significantly enhanced students' use of metacognition, cognition, and memorization strategies, but decreased social strategy development. Chinese-only mediums significantly facilitated cognition and memorization strategy development. Implications for L2 vocabulary education are discussed.

Effect of PM2.5 on MicroRNA Expression and Function in Nasal Mucosa of Rats With Allergic Rhinitis.

BACKGROUND: Particulate matter 2.5 (PM2.5) refers to particulate matter with aerodynamic equivalent diameter less than or equal to 2.5 µm, which is an important component of air pollution. PM2.5 aggravates allergic rhinitis (AR) and promotes AR nasal mucosa inflammation. Therefore, the influence of PM2.5 inhalation exposure on microRNA (miRNA) expression profiles and function in the nasal mucosa of AR rats was investigated. METHODS: Female Sprague Dawley rats were distributed randomly to 2 groups: AR model PM2.5 exposure group (ARE group) and AR model PM2.5-unexposed control group (ARC group). The rats of ARE group were made to inhale PM2.5 at a concentration of 200 µg/m3, 3 h/day, for 30 days. miRNA expression profiles of the nasal mucosa from both groups were determined using an miRNA gene chip and were verified by quantitative real-time PCR (qRT-PCR). Gene function enrichment analysis was performed using bioinformatics analysis. RESULTS: The ARE group revealed 20 significantly differentially expressed miRNAs, including 4 upregulated and 16 downregulated miRNAs (fold change > 1.5 or < 0.66, P < .05). Of these, 9 selected miRNAs were verified by qRT-PCR, and the results of 8 miRNAs were in accordance with the miRNA gene chip results, with highly positive correlation (r = .8583, P = .0031). Numerous target genes of differentially expressed miRNAs were functionally enriched in high-affinity immunoglobulin E receptor signaling, ErbB signaling, mucin O-glycans biosynthesis, transforming growth factor ß signaling, mitogen-activated protein kinase signal transduction, phosphatidylinositol signaling, mucopolysaccharide biosynthesis, mammalian target of rapamycin signaling, T cell receptor signaling, Wnt signaling, chemokine signal transduction, and natural killer cell-mediated cytotoxicity pathways. CONCLUSIONS: PM2.5 causes significant changes in miRNA expression in the nasal mucosa of AR rats. miRNA plays an important role in regulating PM2.5 effects in AR rat biological behavior and mucosal inflammation. This study provides a theoretical basis for the prevention and treatment of AR from the effects of environmental pollution on the gene regulation mechanism.

[Distribution Characteristics and Ecological Risk Assessment of Phthalate Esters in Surface Sediments of the Songhua River].

This study assesses the spatial distribution characteristics and ecological risk of phthalate esters (PAEs) in the surface sediments of the mainstream and tributaries of the Songhua River, China, using concentrations and composition of six PAEs, which were analyzed using gas chromatography-mass spectrometery (GC-MS). We assess the ∑6PAEs ecological risk using the hazard quotient (HQ) method and environmental risk levels (ERL). The results were as follows. ① It was found that the total concentrations of ∑6PAEs ranged from 6832.5 to 36298.9 ng·g-1 dry weight (average 18388.6 ng·g-1), with the main contributions coming from di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP). The difference between the main stream ∑6PAEs (6832.5-36298.9 ng·g-1, average 18616.9 ng·g-1) and the tributary ∑6PAEs (10367.6-26593.3 ng·g-1, average 18264.1 ng·g-1) was not significant (P >0.05). The mean concentrations of individual PAEs in the tributary stream differed little from that of the main stream. The ∑6PAEs concentration of the Songhua River decreased initially but then increased from the upstream to the downstream. The average ∑6PAEs concentration in natural agricultural areas (18677.5 ng·g-1) was similar to that found in urban industrial areas (18063.7 ng·g-1), and DBP and DEHP contributed 98% of ∑6PAEs. ② The main sources of ∑6PAEs were domestic, agricultural production, and industrial production using plasticizers. ③ The ecological risk assessment indicated that DMP and BBP in the surface sediments of the Songhua River did not pose an ecological risk for aquatic organisms, and that DEP was associated with a low ecological risk, whereas DEHP and DBP posed a high ecological risk for aquatic organisms.

T-helper type 1-T-helper type 2 shift and nasal remodeling after fine particulate matter exposure in a rat model of allergic rhinitis.

BACKGROUND: Exposure to fine particulate matter (particulate matter ≤2.5 µm [PM2.5]) increases the risk of allergic rhinitis (AR), but the underlying mechanisms remains unclear. Thus, we investigated the roles of T-helper (Th)1-Th2 cytokines and nasal remodeling after ambient PM2.5 exposure in a rat model of AR. METHODS: Female Sprague-Dawley rats were randomized into six groups: a negative control group, a group of healthy rats exposed to 3000 µg/m3 PM2.5, an ovalbumin (OVA) induced AR model, and three PM2.5-exacerbated AR groups exposed to three different concentrations (200, 1000, and 3000 µg/m3) of PM2.5 for 30 days via inhalation. Nasal symptoms, levels of Th1-Th2 cytokines, the degree of eosinophilia in nasal lavage fluid (NLF), and the messenger RNA (mRNA) expressions of transcription factors GATA-3 and T-bet in the nasal mucosa were measured in each individual rat. Hyperplasia of globet cells and collagen deposition were examined by histology. RESULTS: PM2.5 significantly increased the number of sneezes and nasal rubs in rats with AR. PM2.5 also significantly decreased interferon gamma and increased interleukin (IL) 4 and IL-13 expressions as well as the number of eosinophils in NLF. The mRNA expression of GATA-3 in the nasal mucosa of rats with AR was upregulated by PM2.5, whereas T-bet was significantly downregulated. Statistically significant differences in OVA-specific serum immunoglobulin E, goblet cell hyperplasia, collagen deposition, and transforming growth factor beta 1 levels were observed between the PM2.5-exacerbated AR groups and the AR model group. CONCLUSION: Analysis of our data indicated that an increase in the immune response with Th2 polarization and the development of nasal remodeling may be the immunotoxic mechanisms behind the exacerbation of AR after exposure to PM2.5.