Nitrite Toxicity and Methemoglobin Changes in Southern Flounder,Paralichthys lethostigma,in Brackish Water

This study was performed to estimate the nitrite toxicity to southern flounder, Paralichthys lethostigma, in brackish water (7.5 ppt of salinity). For a LC₅₀ test, 20 fingerlings (5.7 ± 0.4 cm) in each aquarium (15 L) were exposed to the concentrations of 0, 1, 5, 10, 15, 30, 60, 120, and 240 mg NO₂^?‐N/L in duplication for 10 d. Median lethal concentration at 96 h (96‐h LC₅₀) was calculated as 81.6 mg NO₂^?‐N/L. For a verification test, young flounder (164.2 ± 9.1 g) were exposed to a simulated culture condition in recirculating systems (1000 L). Sodium nitrite was not added to control system, whereas it was added to Treatment system 1 (TS 1) and Treatment system 2 (TS 2) to maintain nitrite concentrations of 20 and 30 mg NO₂^?‐N/L, respectively. The plasma nitrite concentrations of the young flounder in TS 1 and TS 2 were 4.5 and 6.6 mg NO₂^?‐N/L, respectively, after 2 wk. At this time, the methemoglobin percentages in TS 1 and TS 2 reached 85.8 and 89.7%, and survival rates were 37.5 and 25.0%, respectively. The results of these tests indicate that southern flounder do not concentrate nitrite in blood from the environment, but they seem to be more sensitive to nitrite compared with other species that do not concentrate nitrite.     

Effects of administration of IH901, a ginsenoside intestinal metabolite,on muscular and pulmonary antioxidant functions after eccentric exercise

This study was conducted to investigate whether administration of IH901, a ginseng intestinal metabolite, ameliorates exercise-induced oxidative stress while preserving antioxidant defense capability in rat skeletal muscles and lung. Eight adult male Sprague-Dawley rats per group were randomly assigned to the resting control, exercise control, resting with IH901 (25, 50, and 100 mg/kg) consumption (R/IH901), or exercise with IH901 (25, 50, and 100 mg/kg) consumption (E/IH901) group. The trained groups ran 35 min 2 days/week for 8 weeks. To analyze the IH901-training interaction, serum biochemical analysis, lipid peroxidation, citrate synthase, protein oxidation, antioxidant and superoxide dismutase in skeletal muscles and lung tissue were measured. Compared to the exercise control group, animals that consumed IH901 had significantly increased exercise endurance times (p < 0.05) and decreased plasma creatine kinase and lactate dehydrogenase levels (p < 0.05), while those in the E/IH901 groups had increased citrate synthase and anti-oxidant enzymes and decreased lipid peroxidation and protein oxidation (p < 0.05). In conclusion, IH901 consumption in aging rats after eccentric exercise has beneficial effects on anti-inflammatory and anti-oxidant activities through down-regulation of pro-inflammatory mediators, lipid peroxidation, and protein oxidation and up-regulation of anti-oxidant enzymes.     

The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants

We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The Physcomitrella genome provides a resource for phylogenetic inferences about gene function and for experimental analysis of plant processes through this plant's unique facility for reverse genetics.     

Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst

Somatic cell nuclear transfer (SCNT) technology has recently been used to generate animals with a common genetic composition. In this study, we report the derivation of a pluripotent embryonic stem (ES) cell line (SCNT-hES-1) from a cloned human blastocyst. The SCNT-hES-1 cells displayed typical ES cell morphology and cell surface markers and were capable of differentiating into embryoid bodies in vitro and of forming teratomas in vivo containing cell derivatives from all three embryonic germ layers in severe combined immunodeficient mice. After continuous proliferation for more than 70 passages, SCNT-hES-1 cells maintained normal karyotypes and were genetically identical to the somatic nuclear donor cells. Although we cannot completely exclude the possibility that the cells had a parthenogenetic origin, imprinting analyses support a SCNT origin of the derived human ES cells.     

Dermal pharmacokinetics of the insecticide furathiocarb in rats

The pharmacokinetics of furathiocarb were studied in vivo in male Sprague-Dawley rats following dermal treatment. HPLC and post-column derivatization were used for the analysis of furathiocarb and its metabolites (carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran). Carbofuran and 3-hydroxycarbofuran were detected in plasma and urine rather than furathiocarb. 3-Ketocarbofuran, another potential metabolite, was not observed in any sample. The concentration of carbofuran was higher than that of 3-hydroxycarbofuran in plasma, but the reverse was the case in urine. The corresponding area under the plasma concentration-time curve, Tmax, and Cmax values of carbofuran and 3-hydroxycarbofuran for 1500 mg kg-1 doses were 2.4-8.0 mg equiv hml-1, 12 h and 0.1-0.4 mg equiv ml-1, respectively. T1/2 was calculated only for 3-hydroxycarbofuran (28 h). Two metabolites were excreted in a dose-dependent manner without saturation.     

Effect of SiC and ZnO Nanoparticles on UV Absorbance and Heat Transfer of PET Composite Film

Zinc oxide (ZnO) and silicon carbide (SiC) nanoparticles were compounded with polyethylene terephthalate (PET) by using a twin screw extruder, and their effect on the UV absorption and heat transfer in PET/ZnO and PET/SiC composite films was investigated. The presence of ZnO and SiC in the PET matrix was verified by X-ray diffraction. The UV absorbance of both PET/ZnO and PET/SiC composite films increased with increasing particle content. The UV absorbance of PET/SiC was higher than that of PET/ZnO under the same particle content. A thermal imaging camera was used to analyze the heat transfer in PET/ZnO and PET/SiC composite films after heating them to 40 °C. As the content of ZnO and SiC particles increased, the temperature decreased more rapidly. PET/SiC showed faster cooling than PET/ZnO because of the higher thermal conductivity of SiC compared to that of ZnO. Response temperature surfaces for PET/ZnO and PET/SiC were obtained by using an exponential decay function and a second order equation, and the elapsed times to cool to room temperature were estimated.     

Transcrytalline structures and crystallization kinetics of Polyarylate/Nylon6 Islands-in-a-Sea conjugate fibers for high performance thermoplastic composite applications

We report the isothermal and non-isothermal crystallization kinetics and associated transcrystalline morphological features of polyarylate(PAR)/nylon6 islands-in-a-sea fibers, where 74 PAR islands serve as reinforcing fibers and nylon6 sea component acts as a semicrystalline matrix in final thermoplastic composites. The temperature-dependent polarized optical microscopic images obtained during a cooling process exhibit that the melt-crystallization is dominated by the interfacial crystallization of nylon6 on the surface of PAR fibers, leading to developing a transcrystalline structure. From the isothermal and non-isothermal melt-crystallization analyses of the islands-in-a sea fiber by using differential scanning calorimetry and the Avrami equation, the overall crystallization rates of the nylon6 sea component in the islands-in-a-sea fiber are found to be highly accelerated by the heterogeneous nucleating effect of the PAR island fibers. In addition, it is revealed that the isothermal and non-isothermal melt-crystallization kinetics of the nylon6 in the islands-in-a-sea fibers consists of two different mechanisms of the primary crystallization owing to the interfacial crystallization and the secondary crystallization due to the bulk crystallization.     

Effect of solvent and blended polymer on electrical conductivity of PEDOT:PSS/polymer blended nanofibers

Poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) and polyethylene oxide (PEO) (or polyvinyl alcohol (PVA)) blended electrospun nanofibers were prepared in the presence of dimethyl sulfoxide (DMSO) and ethylene glycol (EG). The effects of added solvents (DMSO and EG) and blended polymers (PEO and PVA) on electrical conductivity and current-voltage (I-V) response were investigated. Electrical conductivity was dependent on both the additional solvent and blended polymers. PEDOT:PSS/PEO blended nanofibers showed a much higher electrical conductivity than PEDOT:PSS/PVA. EG blended PEDOT:PSS/PEO blended nanofibers showed much higher electrical conductivity than DMSO. The PEDOT:PSS/PEO/EG blended nanofibers web showed the highest value in I-V response.     

Pinnisterols A–C,New 9,11-Secosterols from a Gorgonian Pinnigorgia sp.

Three new 9,11-secosterols, pinnisterols A–C (1–3), were isolated from a gorgonian coral Pinnigorgia sp., collected off the waters of Taiwan. The structures of these compounds were elucidated on the basis of spectroscopic methods. The new sterols 1 and 3 displayed significant inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils, and sterol 1 was found to show moderate cytotoxicity in hepatic stellate cells (HSCs).