Flame-Retardant and Wear Comfort Properties of Modacrylic/FR-Rayon/Anti-static PET Blend Yarns and Their Woven Fabrics for Clothing

This study examined the flame retardant, anti-static, and wear comfort properties of woven fabrics from two types of yarns composed of modacrylic, FR-rayon, cotton, and anti-static PET fibers. The FR-rayon-blended modacrylic fabric mixed with anti-static PET fibers exhibited better flame-retardant and anti-static properties than those of the cotton-blended modacrylic fabric. In addition, the absorption and drying properties of the FR-rayon-blended modacrylic fabric were superior to those of the cotton-blended modacrylic fabric. The thermal conductivity of the FR-rayon-blended fabric was lower than that of the cotton-blended one, whereas the water vapor permeability was slightly higher than that of the cotton-blended one. These wear comfort properties of the FR-rayon-blended fabric were attributed to the micro-pores and longer fiber length of the FR-rayon fibers, as well as their yarn and fabric structural parameters. This study suggests that FR-rayon-blended modacrylic fabric has better flame-retardant and anti-static properties in both twill and rip weaves with good warmth keepability, and higher water and vapor transmission properties than cotton-blended one. In addition, the FR-rayon-blended modacrylic clothing exhibited a better wear comfort feel than the cotton-blended one due to the lower microclimate humidity. This means that FR-rayon-blended modacrylic fabric makes it more comfortable to wear than cotton-blended one.     

Cytogenetic analysis of hybrids and hybrid triploids between the river puffer,Takifugu obscurus,and the tiger puffer,Takifugu rubripes

Cytogenetic analyses of the river puffer, Takifugu obscurus, the tiger puffer, Takifugu rubripes and hybrids produced between female T. obscurus and male T. rubripes and their hybrid triploids (produced by cold shock treatment at 4°C) were performed. T. obscurus had 2n = 44 chromosomes and 1.84 ± 0.019 pg DNA/cell, T. rubripes had 2n = 44 and 2.64 ± 0.015, the hybrids had 2n = 44 and 2.15 ± 0.010 and the hybrid triploids had 3n = 66 and 3.22 ± 0.010. The erythrocyte values of the hybrids were more similar to those for T. obscurus, whereas the hepatocyte, midgut and proximal tubule kidney cell values of the hybrids fell down between those for the parental species (p < .05). The erythrocyte, proximal tubule, hepatocyte and midgut epithelial cell sizes for the hybrid triploids were 1.5‐fold larger than those for the hybrids (p < .05). The thickness of retina and each layer in the hybrid triploids were 1.1‐fold larger than those of the hybrids (p < .05) and did not differ significantly among T. obscurus, T. rubripes and the hybrids (p > .05); however, the hybrid triploids had fewer cell nucleus outer layers than the hybrids (p < .05). Gonad development in the hybrids and hybrid triploids was less matured than in T. obscurus and T. rubripes. The metaphase nucleolus organizer regions (NORs) and the gill cells of T. obscurus, T. rubripes and the hybrids contained two satellite telocentrics, whereas the hybrid triploids contained three satellite telocentrics.     

Thermal effects on the development of <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis> (Hendel) (Diptera: Tephritidae) and model validation in Taiwan

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a major polyphagous insect pest with a worldwide distribution. The effects of temperature on stage-specific development in B. dorsalis were investigated at eight constant temperatures (13.0 °C, 14.4 °C, 16.2 °C, 19.5 °C, 23.8 °C, 27.7 °C, 31.8 °C and 34.8 °C). B. dorsalis developed successfully from the egg stage to the adult stage at all the tested temperatures, except at the lowest temperatures (13.0 °C and 14.4 °C). Stage-specific lower developmental thresholds and thermal constants were determined using linear regression. The lower and higher temperature threshold (TL and TH, respectively) were estimated using the Sharpe-Schoolfield-Ikemoto model. The lower developmental threshold and thermal constant from egg to adult emergence were 9.8 °C and 325.5 degree-days, respectively. The intrinsic optimum temperatures of the egg, larval, pupal and egg to pupal stage were 20.7 °C, 21.8 °C, 21.1 °C, and 22.4 °C, respectively. The temperature range of the B. dorsalis total immature stage from TL to TH was 20.4 °C (13.8 °C - 34.2 °C). The stage-specific developmental completion of B. dorsalis was determined using a two-parameter Weibull function. The daily adult emergence frequency of B. dorsalis was estimated in relation to adult age and temperature using non-linear developmental rate functions and the Weibull function. The date of cumulative 50% adult emergence estimated using non-linear functions was approximately one day earlier than the experimentally observed date. Thermal performance was compared among B. dorsalis populations from different locations.     

Multi-Step Enzymatic Production and Purification of 2-Keto-3-Deoxy-Galactonate from Red-Macroalgae-Derived Agarose

2-keto-3-deoxy sugar acids, which have potential as precursors in medicinal compound production, have gained attention in various fields. Among these acids, 2-keto-3-deoxy-l-galactonate (KDGal) has been biologically produced from D-galacturonate originating from plant-derived pectin. KDGal is also found in the catabolic pathway of 3,6-anhydro-l-galactose (AHG), the main component of red-algae-derived agarose. AHG is converted to 3,6-anhydrogalactonate by AHG dehydrogenase and subsequently isomerized to KDGal by 3,6-anhydrogalactonate cycloisomerase. Therefore, we used the above-described pathway to produce KDGal from agarose. Agarose was depolymerized to AHG and to agarotriose (AgaDP3) and agaropentaose (AgaDP5), both of which have significantly higher molecular weights than AHG. When only AHG was converted to KDGal, AgaDP3 and AgaDP5 remained unreacted. Finally, KDGal was effectively purified from the enzymatic products by size-exclusion chromatography based on the differences in molecular weights. These results show that KDGal can be enzymatically produced and purified from agarose for use as a precursor to high-value products.     

Effect of LDPE microplastics on chemical properties and microbial communities in soil

The accumulation of plastics in the soil ecosystem poses an increasing environmental concern worldwide. However, little is known about the effect of plastic concentrations on soil properties and soil biota. In this study, we investigated the effect of low-density polyethylene (LDPE) microplastics (MPs) on the chemical and microbial properties of agricultural soil using a set of microcosm experiments. The soil was incubated for 100 days with LDPE at concentrations of 0%, 0.1%, 1%, 3%, 5%, and 7% at 25°C with 70% water-holding capacity. Along with soil chemical analysis, we conducted an analysis of soil microbial properties on the first day and again after 100 days of incubation. LDPE concentrations of ≥1% significantly (p < .05) decreased the pH but increased the electrical conductivity of the soil in comparison with the control (0% LDPE at 100 days). Increasing the LDPE concentration did not affect the soil exchangeable cation content or the available Pb concentration. Firmicutes were the most abundant phyla in the soil on the first day, whereas Proteobacteria, Firmicutes and Actinobacteria became dominant in all treatments after 100 days. An increasing LDPE concentration increased the abundance of Actinobacteria and decreased Proteobacteria. Principal component analysis demonstrated that only 7% LDPE was positively correlated with Actinobacteria, indicating that higher concentrations of LDPE contributed to the growth of this phylum. The findings of this study imply that MP contamination could affect soil chemical properties and microbial activity and that these effects primarily depend on MP concentrations in soil.     

Effects of Steeping Temperatures and Periods of Waxy Rice on Expansion Properties of Gangjung (a traditional Korean oil‐puffed rice snack)

This study was conducted to investigate the effect of steeping conditions of waxy rice, temperatures (15, 25, and 35°C) and time periods (1, 11, and 21 days) on the expansion ratio of gangjung (a traditional Korean oil‐puffed rice snack). Physicochemical properties of waxy rice flour steeped under various conditions and expansion properties of gangjung made of the steeped waxy rice flour were investigated, and multiple regression analyses were applied between those properties to identify major physicochemical factors that optimally predict the expansion ratio of gangjung. As steeping temperature and time periods of waxy rice changed from the lowest to the highest, the expansion ratio of gangjung markedly increased (from 1,022 to 2,533%). Yet, the expansion ratio of the waxy rice sample steeped for 11–21 days at 35°C was not significantly different from the sample steeped for 21 days at 25°C, indicating that the lengthy steeping process for gangjung making can be shortened by increasing the steeping temperature. Physicochemical properties include moisture (γ = 0.85), protein (γ = –0.91), ash (γ = –0.84), potassium (γ = –0.89), magnesium (γ = –0.88), phosphorous (γ = –0.91), peak viscosity (γ = 0.77), and breakdown (γ = 0.94) of steeped waxy rice flour. These properties were highly correlated with expansion ratio (P < 0.01). Multiple regression analysis showed that the expansion ratio of gangjung was predicted successfully by the phosphorous content and breakdown value of steeped waxy rice flour.     

Combined effect of biochar and soil moisture on soil chemical properties and microbial community composition in microplastic-contaminated agricultural soil

Accumulation of microplastics (MPs) in agricultural environments has caused growing concern in recent years because of its detrimental impacts on soil quality, crop productivity and ecosystem function. This study was conducted to assess the impact of biochar on soil chemical and microbial properties in a MP-contaminated soil under two moisture regimes. Soil was contaminated with 1% (w/w) of low-density polyethylene MPs. Four types of standard biochar, that is, oil seed rape (OSR) biochar produced at 550°C (OSR 550) and 700°C (OSR 700) and soft wood pellet (SWP) biochar produced at 550°C (SWP 550) and 700°C (SWP 700), were applied at a rate of 5% (w/w). The control was maintained without MP addition. The samples were incubated in soil with two moisture regimes, that is, at 30% and 70% of the water holding capacity, and the soil chemical and microbiological properties were assessed after 100 days of incubation. OSR biochar application significantly increased soil pH (8.53–8.81) and electrical conductivity (0.51–0.58 dS/m) in both moisture regimes. The effect of biochar application on soil enzyme activity and microbial community composition did not show a clear trend. However, SWP 700 biochar improved soil enzyme activity compared with that of the control and improved bacterial diversity and evenness compared with those of other biochars, which was attributed to the high surface area available for microbial colonization. Low soil moisture content significantly reduced enzyme activity and bacterial richness even with biochar amendment, except for SWP 550 biochar. This study implies the suitability of biochar for improvement of soil quality in MP contaminated soil under both moisture regimes. However, further long-term studies are needed to get a clear understanding on the impact of different types of biochar on MP-contaminated soil.