Accelerometer-measured sedentary volume and bouts during the segmented school day among Chinese school students.

Background: This study examined sedentary volume and bouts of Chinese primary and middle school students during different segments of a school day and determined whether gender and school level are associated with their sedentary volume and bouts. Methods: A total of 472 students participated in this study. Accelerometers were used to measure the sedentary volume and sedentary bouts of different durations (i.e., 1-4 min, 5-9 min and ≥10 min) during all segments. Results: The participants spent the majority of their time in sitting (61.7%) and sitting bouts of ≥10 min (37.3%). They spent higher percentages of time in sitting during regular classes (76.7%) and out-of-school time (54.5%), and lower during physical education (PE) classes (32.2%), lunch break (35.4%) and recess (38.0%). The highest proportions of time were in sedentary bouts of ≥10 min during regular classes (50.2%), out-of-school time (28.0%) and lunch break (18.8%), while the greatest percentages occurred in sitting bouts of 1-4 min during PE class (16.4%) and recess (18.6%). Girls and middle school students had higher percentages of sedentary volume than boys and primary school students during most segments. They spent greater proportions of time in sitting bouts of ≥10 min during regular classes, lunch break, and out-of-school time, and higher proportions in sedentary bouts of 1-4 min than boys and primary students during PE classes. Conclusion: Regular class and out-of-school time were identified as key segments for reducing sedentary volume and breaking up prolonged sitting. Interventions on interrupting prolonged sitting during lunch break should also be explored. Girls and middle school students should receive more attention in future interventions.

A biological strategy for sulfide control in sewers: Removing sulfide by sulfur-oxidizing bacteria.

Sulfide produced from sewers is considered one of the dominant threats to public health and sewer lifespan due to its toxicity and corrosiveness. In this study, we developed an environmentally friendly strategy for gaseous sulfide control by enriching indigenous sulfur-oxidizing bacteria (SOB) from sewer sediment. Ceramics acted as bio-carriers for immobilizing SOB for practical use in a lab-scale sewer reactor. 16 S rRNA gene sequences revealed that the SOB consortium was successfully enriched, with Thiobacillus, Pseudomonas, and Alcaligenes occupying a dominant abundance of 64.7% in the microbial community. Metabolic pathway analysis in different acclimatization stages indicates that microorganisms could convert thiosulfate and sulfide into elemental sulfur after enrichment and immobilization. A continuous experiment in lab-scale sewer reactors confirmed an efficient result for sulfide removal with hydrogen sulfide reduction of 43.9% and 85.1% under high-sulfur load and low-sulfur load conditions, respectively. This study shed light on the promising application for sewer sulfide control by biological sulfur oxidation strategy.

Characterization of root-knot nematodes infecting mulberry in Southern China.

China is one of the largest producers of mulberry in the world. With the development of the sericulture industry, several pests and diseases have occurred in rapid succession, chief among which is the root-knot nematode disease affecting mulberry. According to the China cocoon and silk exchange, cocoon prices have doubled since the beginning of 2009 and rose to 92,700 yuan ($135,770) per tonne in mid-April 2010. According to customs statistics, in the first eight months of 2011, China's silk merchandise exports amounted to 2.39 billion yuan. In this study, sequencing of the rDNA-ITS and D2-D3 region of the 28S rRNA gene was combined with root-knot nematode morphological characteristics to identify the root-knot nematode infecting mulberry in the Guangdong, Guangxi, and Hunan provinces of China. This resulted in the identification of Meloidogyne enterolobii as the causal species of root-knot nematode infections in these regions. Importantly, the morphological data agreed completely with our molecular phenotyping efforts, indicating that rDNA sequencing could provide a more clear-cut and less labor-intensive means of characterizing root-knot nematode infections in the future. The differences between this study and the previous studies were discussed, as well as the damage degree, host species and influence scope of M. enterolobii.China is one of the largest producers of mulberry in the world. With the development of the sericulture industry, several pests and diseases have occurred in rapid succession, chief among which is the root-knot nematode disease affecting mulberry. According to the China cocoon and silk exchange, cocoon prices have doubled since the beginning of 2009 and rose to 92,700 yuan ($135,770) per tonne in mid-April 2010. According to customs statistics, in the first eight months of 2011, China's silk merchandise exports amounted to 2.39 billion yuan. In this study, sequencing of the rDNA-ITS and D2-D3 region of the 28S rRNA gene was combined with root-knot nematode morphological characteristics to identify the root-knot nematode infecting mulberry in the Guangdong, Guangxi, and Hunan provinces of China. This resulted in the identification of Meloidogyne enterolobii as the causal species of root-knot nematode infections in these regions. Importantly, the morphological data agreed completely with our molecular phenotyping efforts, indicating that rDNA sequencing could provide a more clear-cut and less labor-intensive means of characterizing root-knot nematode infections in the future. The differences between this study and the previous studies were discussed, as well as the damage degree, host species and influence scope of M. enterolobii.

Three-Dimensional Meso-Structure-Based Model for Evaluating the Complex Permittivity of Asphalt Concrete.

Microwave heating is an emerging alternative pretreatment method for road maintenance in cold seasons. The thermal behavior of asphalt pavement under microwave heating is mainly determined by the complex permittivity of the asphalt mixture. In this study, an innovative approach for calculating the complex permittivity of an asphalt mixture based on a three-dimensional meso-scale heterogeneous structure was proposed. A series of experiments was conducted to verify the accuracy of this approach. The effect of porosity, void size, moisture content and aggregate gradation on the complex permittivity for an asphalt mixture were computationally analyzed based on the validated approach. Moreover, the applicability of commonly used classical dielectric models was analyzed. The classical Lichtenecker-Rother (LR) dielectric model was modified on the basis of simulation data for various conditions. The results showed that the real part of the complex permittivity decreased with the increase in porosity. Some sudden change in the imaginary part of the complex permittivity was observed within the frequency range from 2.6 GHz to 3.9 GHz. A larger air void size would lead to a larger frequency at which sudden change occurs. The real part and imaginary part of the complex permittivity tend to be smaller when more coarse aggregates are replaced with fine aggregates. Both the real part and the imaginary part of the complex permittivity increase with higher moisture content due to the stronger dielectric property of water. Each 1% increase in moisture content would lead to about a 3~4% increase in the real part of the complex permittivity. The determination coefficients R2 for the real part and the imaginary part of the complex permittivity fitted by the modified Brown model were the maximum values, which were 0.922 and 0.980, respectively. The method presented in this study is useful for transportation agencies to optimize microwave heating during winter maintenance.

The moderating effect of physical activity on the relationship between neutrophil count and depressive symptoms.

Variations in immune cell counts can trigger depressive symptoms, while physical activity effectively reduces the risk and severity of depressive symptoms. This study, based on the NHANES database, analyzes the relationship between neutrophil count and depressive symptoms and explores the moderating effect of physical activity on this relationship. Cross-sectional data from the NHANES database were extracted, including immune cell counts, PHQ-9 scores for self-assessment of depressive symptoms, and Global Physical Activity Questionnaire (GPAQ) scores (PA). The interrelations among physical activity, neutrophil count, and depressive symptoms were analyzed. After controlling for confounding factors, neutrophil count was found to have a significant role in identifying depressive symptoms with an odds ratio (OR) [95% Confidence Interval (CI)] = 1.13 [1.02, 1.251]; the moderating effect of physical activity on the impact of neutrophil count on depressive symptoms was statistically significant (coefficient = -0.0028, P < 0.05). Neutrophil count may be a significant factor in identifying depressive symptoms in adults. As an effective moderating factor, physical activity can mitigate the impact of neutrophil count on depressive symptoms to a certain extent.

Naturally aged polylactic acid microplastics stunted pakchoi (Brassica rapa subsp. chinensis) growth with cadmium in soil.

Biodegradable microplastics (BMPs) and cadmium (Cd) are posing threats to agro-systems especially to plants and current studies mostly used virgin BMPs to explore their ecological effects. However, effects of naturally aged BMPs and their combined effects with Cd on pakchoi are yet to be unraveled. Therefore, this study incubated naturally aged polylactic acid (PLA) MPs through soil aging process and investigated the single and combined effects of Cd and PLA MPs (virgin and aged) on pakchoi (Brassica rapa subsp. chinensis) morphology, antioxidant systems and soil microbial activities. Our results found that after being deposited in soil for six months, aged PLA (PLAa) MPs formed with a fractured surface, demonstrating more detrimental effects on pakchoi than virgin ones. PLA/PLAa MPs and Cd stunted pakchoi growth, caused oxidative stress and altered the biophysical environment in soil, separately. Moreover, co-existence of PLA/PLAa MPs and Cd caused greater damages to pakchoi than applied alone. The co-presence of PLAa MPs and Cd inhibited pakchoi biomass accumulation rate by 92.2 % compared with the no-addition group. The results unraveled here emphasized BMPs, especially aged BMPs, could trigger negative effects on agro-systems with heavy metals. These findings will give reference to future holistic assessments of BMPs' ecological effects.

Novel Curcumin Analogue L6H4 in Treating Liver Fibrosis and Type 2 Diabetes.

Purpose: The objective of this study was to evaluate the therapeutic efficacy of the curcumin analogue L6H4 in attenuating liver fibrosis and alleviating insulin resistance in streptozotocin-induced diabetic rats. Methods: Male Sprague-Dawley rats were fed a high-fat diet to induce insulin resistance, followed by streptozotocin injection to induce diabetes. The rats were then treated with L6H4 for eight weeks. Body weight, metabolic parameters, liver function, and liver histopathology were evaluated. Immunohistochemistry was performed to assess the expression of TGF-ß1, TIMP-2, and MMP-2 in liver tissues. Statistical analysis was conducted using one-way ANOVA and Spearman rank correlation test. Results: L6H4 treatment effectively reversed the weight gain associated with a high-fat diet and improved metabolic parameters in diabetic rats. Liver function markers, such as ALT and AST, were reduced after L6H4 treatment. Histological analysis showed improved liver morphology and reduced fibrosis in L6H4-treated rats. Electron microscopy revealed improved ultrastructural features of hepatocytes. Immunohistochemistry demonstrated downregulation of TGF-ß1 and TIMP-2 expression and restoration of MMP-2 expression in the liver tissue of L6H4-treated rats. Correlation analysis showed a significant positive correlation between TGF-ß1 and TIMP-2 expression. Conclusion: The findings suggest that L6H4 has therapeutic potential in attenuating liver fibrosis and alleviating insulin resistance in streptozotocin-induced diabetic rats. The hepatoprotective effect of L6H4 may be attributed to its anti-inflammatory properties and its ability to target molecules involved in fibrosis. Further research is warranted to explore the potential of L6H4 as a treatment option for nonalcoholic fatty liver disease and type 2 diabetes.

[Spatial Variation and Potential Sources of Microplastics in Rivers in Tongzhou District, Beijing].

Microplastics are emerging contaminants, which can also absorb other contaminants, threatening the health of river ecosystems. However, research on the pollution of microplastics in rivers in northern China is still lacking. In this study, based on the sampling and analysis of water samples in 19 sites in six rivers in Tongzhou district, Beijing, the composition, spatial variation, and potential sources of microplastics were explored. The results showed that all sites were contaminated by microplastics, and the abundance of microplastics in the Xiaozhong River was the highest among all sites (3.50×104 n·m-3), which was 4.04 times that in the Yunchaojian River. The proportion of microplastics with particle sizes smaller than 2000 µm was 90.49%, and microplastics with particle sizes larger than 4000 µm were only found in two out of 19 sampling sites. The microplastics were fiber, film, fragment, and granule shaped. The proportion of fiber microplastics was the highest (90.23%) among all shapes. Most (84.29%) of the microplastics were transparent and blue. Rayon was the most common microplastic in each site, and its proportion in each site was over 66.67%. The proportions of other types of microplastics differed largely among different sites. Spatially, the abundance and types of microplastics in the upper reaches were higher than those in the lower reaches. According to spatial variations in shapes, types, colors, and abundance of microplastics, the potential sources of microplastics were identified. The potential sources of fiber microplastics were washing clothing and using fishing gear and dust-proof nets.

[Composition and Distribution of Microplastics in the Water and Sediments of Urban Rivers in Beijing].

It has been confirmed that microplastics widely exist in the natural environment, causing potential harm to organisms and humans. An investigation into the occurrence of microplastics is helpful to understand the level of pollution of microplastics in urban rivers and sediments. In this study, eight sampling points of water samples and three of sediments samples were placed along the North Canal and Huaihe River in Beijing, to compare the composition and distribution characteristics of the abundance, particle size, color, shape, and species of microplastics. The results showed that the abundance of microplastics in the water and sediments of the North Canal were(1941±201)-(8155±1781) n·m-3(n refers to the number of microplastics) and (120±11)-(268±31) n·kg-1, respectively. The average abundance of microplastics in the water of the North Canal was 4160 n·m-3. Compared with the North Canal, the pollution degree of microplastics in the Huaihe River was lower with an average abundance of 2357 n·m-3. Furthermore, the abundance of microplastics in the water and sediments in the upper reaches of the North Canal was higher than that in the lower reaches. No significant difference of microplastics distribution was observed in the water of the Huaihe River on the whole; however, there was a marked difference in abundance between the two distant locations. The main particle size range of microplastics at all site points was<300 µm, and mostly white/transparent(50.75%-83.91%); the main shape were fragments(50.00%-95.08%) and fibers(3.86%-30.00%). Polyurethane(PU) and ethylene vinyl acetate(EVA) were two main plastic species found at all sites. Microplastics in the water and sediments of the North Canal might have originated from urban construction and development, while the surrounding villages might have only affected the abundance of microplastics in the Huaihe River.

Genetic Diversity of the root-knot nematode Meloidogyne enterolobii in Mulberry Based on the Mitochondrial COI Gene.

This study explores the genetic diversity and structure of Meloidogyne enterolobii in mulberry in China. The COI mitochondrial gene (mtCOI) in M.enterolobii populations in Guangdong, Guangxi, and Hunan Provinces was PCR-amplified, sequenced, and analyzed for genetic diversity. The total number of variations, haplotypes (Hap), the average number of nucleotide differences (k), haplotype diversity (H), and nucleotide diversity (π) of mtCOI were 25, 11, 4.248, 0.900, and 0.00596, respectively. Insignificant differences in Fst value (0.0169) and a high level of gene flow (7.02) were detected among the 19-mulberry root-knot nematode populations, and high genetic variation within each population and a small genetic distance among populations were observed. Both phylogenetic analyses and network mapping of the 11 haplotypes revealed a dispersed distribution pattern of 19 mulberry root-knot nematode populations and an absence of branches strictly corresponding to the 19 range sampling sites. The neutrality test and mismatch analysis indicated that mulberry root-knot nematode populations experienced a population expansion in the past. The analysis of molecular variance (AMOVA) revealed that the genetic differentiation of M. enterolobii was mainly contributed by the variation within each group. No significant correlation was found between the genetic distance and geographical distance of M. enterolobii populations. The findings of this study provide a profound understanding of the M. enterolobii population and will inform the development of strategies to combat and manage root-knot nematodes in mulberry.

Microchannel Structural Design For a Room-Temperature Liquid Metal Based Super-stretchable Sensor.

Room-temperature liquid metal has been widely used in flexible and stretchable sensors, focusing on embedding liquid metal in microchannels, liquid metal microdroplets formation, captive sensors, and liquid metal nanoparticles, etc. In this paper, a facile Eutectic Galium-Indium (EGaln) liquid-based microfluidic high-sensitivity, skin-mountable, and ultra-soft stretchable sensor is developed. It comprises Ecoflex microfluidic assembly filled with EGaln, which serves as the working fluid of the stretchable sensor. The lithography method is applied to achieve microfluidic channel. The microfluidic channel is optimized by using topology method and finite element analysis, making this device with high conformability and high stretchability. This method achieved an outstanding effect on elastomer-encapsulated strain gauge, which displays an approximately linear behavior with a gauge factor (GF). The GF could reach as high as 4.95 when the strain ultimately reached 550%. Applications of detection of the joints, fingers, and wrists has been conducted and showed excellent results. This work can further facilitate the exploration and potential realization of a functional liquid-state device technology with superior mechanical flexibility and conformability.