Effects of Road Deicer Runoff on Benthic Macroinvertebrate Communities in Korean Freshwaters with Toxicity Tests of Calcium Chloride (CaCl2)     

Min Jeong Baek  Tae Joong Yoon  Dong Gun Kim  Cha Young Lee  Kijong Cho  Yeon Jae Bae 《Water, air, and soil pollution》2014,225(6):1-14

Quantifying plant biomass and related processes such as element allocation is a major challenge at the scale of entire riparian zones. We applied sub-decimetre-resolution (5 cm) remote sensing using an unmanned aircraft system (UAS) in combination with field sampling to quantify riparian vegetation biomass at three locations (320-m river stretches) along a mining-impacted boreal river and estimated the amounts of Cd, Cu, and Zn stored in the dominant species. A species-level vegetation map was derived from visual interpretation of aerial images acquired using the UAS and field sampling to determine species composition and cover. Herbaceous and shrub biomass and metal contents were assessed by combining the vegetation maps with field sampling results. Riparian zone productivity decreased from 9.5 to 5.4 t ha^?1 with increasing distance from the source of contamination, and the total amount of vegetation-bound Cd and Zn decreased from 24 to 0.4 and 3,488 to 211 g, respectively. Most Cu was stored at the central location. Biomass and metal contents indicated large variation between species. Salix spp. comprised only 17 % of the total dominant-species biomass but contained 95 % of all Cd and 65 % of all Zn. In contrast, Carex rostrata/vesicaria comprised 64 % of the total dominant-species biomass and contained 63 % of all Cu and 25 % of all Zn. Our study demonstrates the applicability of UAS for monitoring entire riparian zones. The method offers great potential for accurately assessing nutrient and trace element cycling in the riparian zone and for planning potential phytoremediation measures in polluted areas.  相似文献   

Powering fuel cells with CO via aqueous polyoxometalates and gold catalysts     

Kim WB  Voitl T  Rodriguez-Rivera GJ  Dumesic JA 《Science (New York, N.Y.)》2004,305(5688):1280-1283

Electricity was produced by catalytic oxidation of carbon monoxide (CO) by using gold catalysts at room temperature. The observed rates are faster than conventional processes operating at 500 kelvin or higher for the conversion of CO with water to produce hydrogen and carbon dioxide through the water-gas shift (WGS). By eliminating the WGS reaction, we remove the need to transport and vaporize liquid water in the production of energy for portable applications. This process can use CO-containing gas streams from the catalytic reforming of hydrocarbons to produce an aqueous solution of reduced polyoxometalate compounds that can be used to generate power. The reduced polyoxometalate can be reoxidized in fuel cells that contain simple carbon anodes.  相似文献   

Evaluation of new direct dyes for mutagenicity using the salmonella mammalian mutagenicity assay     

Jin-Seok Bae  Harold S. Freeman 《Fibers and Polymers》2005,6(4):297-305

A series of new direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine, were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. All of the dyes examined were judged to be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of direct dyes for mutagenicity.  相似文献   

Svalbamides A and B,Pyrrolidinone-Bearing Lipodipeptides from Arctic Paenibacillus sp.     

Young Eun Du  Eun Seo Bae  Yeonjung Lim  Jang-Cheon Cho  Sang-Jip Nam  Jongheon Shin  Sang Kook Lee  Seung-Il Nam  Dong-Chan Oh 《Marine drugs》2021,19(4)

Two new secondary metabolites, svalbamides A (1) and B (2), were isolated from a culture extract of Paenibacillus sp. SVB7 that was isolated from surface sediment from a core (HH17-1085) taken in the Svalbard archipelago in the Arctic Ocean. The combinational analysis of HR-MS and NMR spectroscopic data revealed the structures of 1 and 2 as being lipopeptides bearing 3-amino-2-pyrrolidinone, d-valine, and 3-hydroxy-8-methyldecanoic acid. The absolute configurations of the amino acid residues in svalbamides A and B were determined using the advanced Marfey’s method, in which the hydrolysates of 1 and 2 were derivatized with l- and d- forms of 1-fluoro-2,4-dinitrophenyl-5-alanine amide (FDAA). The absolute configurations of 1 and 2 were completely assigned by deducing the stereochemistry of 3-hydroxy-8-methyldecanoic acid based on DP4 calculations. Svalbamides A and B induced quinone reductase activity in Hepa1c1c7 murine hepatoma cells, indicating that they represent chemotypes with a potential for functioning as chemopreventive agents.  相似文献   

Antioxidant Capacity of Newly Developed Pigmented Rice Cultivars in Korea     

Mi Young Kang  Catherine W. Rico  Hyun Jung Bae  Sang Chul Lee 《Cereal Chemistry》2013,90(5):497-501

The antioxidant capacity of newly developed and highly popular pigmented rice cultivars (black rice, Galsaekchalmi, Jeoktomi, Hongchalmi, and Nogwonmi) in South Korea was analyzed. The rice grains were ground into powder, extracted with 70% ethanol, filtered, and concentrated with a rotary evaporator. The samples were analyzed for phenolic, flavonoid, and phytic acid contents, free radical scavenging activity, reducing power, ferrous ion chelating ability, lipid peroxidation inhibition, and superoxide dismutase‐like activity. The ethanolic extracts from pigmented rice cultivars showed greater antioxidant activity than that of the normal white rice. The black rice exhibited the highest free radical scavenging activity, ferrous chelating ability, and total phenolic and flavonoid contents. The reducing power and phytic acid content were found to be highest in Hongchalmi cultivar. The inhibition of lipid peroxidation was markedly higher in Jeoktomi compared with the other rice samples. The Nogwonmi rice showed the lowest antioxidant activity among the pigmented varieties analyzed. These findings provide valuable information on the antioxidant potential of newly developed pigmented rice varieties and may assist plant breeders in the selection of cultivars for the development of new lines of rice with enhanced functional quality.  相似文献   

Seasonal variation of soil respiration rates in a secondary forest and agroforestry systems   总被引：2，自引：0，他引：2  

Kikang Bae  Don Koo Lee  Timothy J. Fahey  Soo Young Woo  Amos K. Quaye  Yong-Kwon Lee 《Agroforestry Systems》2013,87(1):131-139

Agroforestry systems are widely practiced in tropical forests to recover degraded and deforested areas and also to balance the global carbon budget. However, our understanding of difference in soil respiration rates between agroforestry and natural forest systems is very limited. This study compared the seasonal variations in soil respiration rates in relation to fine root biomass, microbial biomass, and soil organic carbon between a secondary forest and two agroforestry systems dominated by Gmelina arborea and Dipterocarps in the Philippines during the dry and the wet seasons. The secondary forest had significantly higher (p < 0.05) soil respiration rate, fine root biomass and soil organic matter than the agroforestry systems in the dry season. However, in the wet season, soil respiration and soil organic matter in the G. arborea dominated agroforestry system were as high as in the secondary forest. Whereas soil respiration was generally higher in the wet than in the dry season, there were no differences in fine root biomass, microbial biomass and soil organic matter between the two seasons. Soil respiration rate correlated positively and significantly with fine root biomass, microbial biomass, and soil organic C in all three sites. The results of this study indicate, to some degree, that different land use management practices have different effects on fine root biomass, microbial biomass and soil organic C which may affect soil respiration as well. Therefore, when introducing agroforestry system, a proper choice of species and management techniques which are similar to natural forest is recommended.  相似文献   

Halochromic chemosensor prepared by pyran-based nanofibers     

Sung-Hoon Kim  Jin-Seok Bae 《Fibers and Polymers》2013,14(12):1981-1984

Colorimetric chemosensors can easily detect and prevent the primary danger or change of the surrounding environmental pollutions and sources of infection in the various fields. Pyran based colorant having the function of colorimetric chemosensor was synthesized. Synthesized colorant was characterized by ¹H NMR, GC-Mass, EA and UV-vis spectroscopy and then mixed with polyacrylonitrile for electrospinning. Electrospun fibers containing pyran based colorant were used as pH detecting chemosensor and were analyzed by SEM, XPS, and spectrophotometer.  相似文献   

Influence of Extraction Solvents on Antioxidant Activity and the Content of Bioactive Compounds in Non-pungent Peppers   总被引：1，自引：1，他引：0  

Bae H  Jayaprakasha GK  Crosby K  Jifon JL  Patil BS 《Plant foods for human nutrition (Dordrecht, Netherlands)》2012,67(2):120-128

Bioactive compounds in foods have been shown to maintain human health. However, the relative amounts of bioactive compounds and the variation in the amounts are still poorly understood. In this study, the efficacy of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and a methanol:water mixture), as well as the levels of certain bioactive compounds in non-pungent pepper cultivars (TMH, TMJ, PA137, and B58) were investigated using high-performance liquid chromatography (HPLC). Antioxidant activities were determined using 2,2,-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and deoxyribose degradation. Hexane extracts had the highest level of carotenoids (47.2-628.8 μg/g), and methanol extracts contained maximum flavonoids (24.9-152.2 μg/g) in four different cultivars. Higher DPPH scavenging activity was found in the hexane extracts from TMH, TMJ, PA137, and B58 (IC?? value: 0.67, 0.74, 0.55, and 0.48 μg/ml, respectively), whereas the reducing power was high in ethyl acetate and acetone extracts. Inhibition of deoxyribose degradation was highest in methanolic extracts from TMH, TMJ, PA137, and B58 (51.2, 49.5, 52.6, and 47.4 %, respectively). These data demonstrate that solvent chemical properties such as polarity can differentially impact the efficiency with which different bioactive compounds are recovered from foods, and this could lead to differences in estimated biological activity such as antioxidant capacity.  相似文献   

Molecular cloning of a cDNA encoding vitellogenesis-inhibiting hormone in the whiteleg shrimp Litopenaeus vannamei and preparation of its recombinant peptide using an E. coli expression system     

Naoaki Tsutsui  Tsuyoshi Ohira  Tomoyuki Okutsu  Junpei Shinji  Sun-Hye Bae  Bong Jung Kang  Marcy N. Wilder 《Fisheries Science》2013,79(3):357-365

The cDNA encoding a precursor of Liv-SGP-G, the most abundant crustacean hyperglycemic hormone-family peptide in the sinus gland of the whiteleg shrimp Litopenaeus vannamei, was cloned by RT-PCR coupled with 5′- and 3′-RACE. The determined cDNA sequence consisted of 621 nucleotides comprising a 69-bp 5′-untranslated region, a 357-bp open reading frame, and a 195-bp 3′-untranslated region. The deduced sequence of 72 amino acid residues corresponding to mature Liv-SGP-G was completely identical to that of natural Liv-SGP-G, determined in our previous study. The recombinant Liv-SGP-G was thereafter heterologously expressed in Escherichia coli, and its vitellogenesis-inhibiting activity in ex vivo cultured ovarian fragments was examined. The recombinant peptides inhibited vitellogenin gene expression with almost the same efficacy as that of natural Liv-SGP-G purified from sinus glands.  相似文献   

Optimum feeding rates in juvenile olive flounder,Paralichthys olivaceus,at the optimum rearing temperature     

O.E. Okorie  J.Y. Bae  K.W. Kim  M.H. Son  J.W. Kim  S.C. Bai 《Aquaculture Nutrition》2013,19(3):267-277

Two feeding trials were carried out to determine the optimum feeding rates in juvenile olive flounder, Paralichthys olivaceus, at the optimum rearing temperature. Fish averaging 5.0 ± 0.11 g (mean ± SD) in experiment 1 and 20.2 ± 0.54 g (mean ± SD) in experiment 2 were fed a commercial diet at the feeding rates of 0%, 3.0%, 4.0%, 4.25%, 4.5% and 4.75% body weight (BW) day^?1 and satiation (5.52% BW day^?1) in experiment 1 and 0%, 1.0%, 2.0%, 3.0% and 3.5% BW day^?1 and satiation (4.12% BW day^?1) in experiment 2 at 20 ± 1 °C. Both feeding trials lasted for 2 weeks. Results from experiment 1 indicated that weight gain (WG) and specific growth rate (SGR) of fish fed to satiation were significantly higher than those of fish fed at other feeding rates while feed efficiency (FE) and protein efficiency ratio (PER) of fish fed at 4.25% BW day^?1 were significantly higher than those of fish fed to satiation and fish fed at 3.0% BW day^?1 (P < 0.05). In experiment 2 WG, SGR and PER leveled out after the feeding rate of 3.5% BW day^?1 whereas FE reached a plateau at 3.0% BW day^?1. anova of FE indicated that the optimum feeding rates in 5.0 and 20 g juvenile olive flounder could be 4.25% and 3.0% BW day^?1, respectively. Broken line analysis of WG suggested the optimum feeding rates of 5.17% and 3.47% BW day^?1 in 5.0 and 20 g fish, respectively. Therefore, these results indicated that the optimum feeding rates could be >4.25 but <5.17% BW day^?1 for 5.0 g, and it could be >3.0 but <3.47% BW day^?1 for 20 g size of juvenile olive flounder at the optimum rearing temperature.  相似文献