Superhydrophobicity of cellulose triacetate fibrous mats produced by electrospinning and plasma treatment

Nano/micro-fibrous cellulose triacetate (CTA) mats were prepared by electrospinning a fixed concentration of CTA with different methylene chloride (MC)/ethanol (EtOH) ratios and with various concentrations of CTA at a fixed MC/EtOH 80/20 (v/v) ratio. All of the electrospun CTA mats had a high water contact angle (WCA) compared to the CTA cast film. At a solvent composition of 80/20 (v/v) and 5 wt.% CTA concentration, the CTA mat without plasma treatment had good surface roughness and electrospinning processability, and its WCA was 142°. To further improve its hydrophobicity, the CTA fibrous mat electrospun from the 5 wt.% solution of CTA was treated with a CF₄ plasma for various times. Superhydrophobicity could be obtained after the CF₄ plasma treatment. The WCA of the CTA mat reached as high as 153° after plasma treatment for 60 s.     

Down-regulation of FoxO-dependent c-FLIP expression mediates TRAIL-induced apoptosis in activated hepatic stellate cells

Activated hepatic stellate cells which contribute to liver fibrosis have represented an important target for antifibrotic therapy. In this study, we found that TRAIL inhibited PI3K/Akt-dependent FoxO phosphorylation and relocated FoxO proteins into the nucleus from the cytosol in activated human hepatic stellate LX-2 cells. The accumulated FoxO proteins in the nucleus led to down-regulation of c-FLIP_L/S expression, resulting in the activation of apoptosis-related signaling molecules including the activation of caspase-8, -3, and Bid, as well as mitochondrial cytochrome c release. These results were supported by showing that siRNA-mediated knockdown of FoxO led to restoration of c-FLIP_L/S expression and resistance to TRAIL-induced apoptosis after treatment of LX-2 cells with TRAIL. Furthermore, c-FLIP_L/S-transfected LX-2 cells showed the decreased sensitivity to TRAIL-induced apoptosis. Collectively, our data suggest that sequential activation of FoxO proteins under conditions of suppressed PI3K/Akt signaling by TRAIL can down-regulate c-FLIP_L/S, consequently promoting TRAIL-induced apoptosis in LX-2 cells. Therefore, the present study suggests TRAIL may be an effective strategy for antifibrotic therapy in liver fibrosis.     

Design and synthesis of 4-aryl-4-oxobutanoic acid amides as calpain inhibitors

The involvement of μ-calpain in neurological disorders, such as stroke and Alzheimer’s disease has attracted considerable interest in the use of calpain inhibitors as therapeutic agents. 4-Aryl-4-oxobutanoic acid amide derivatives 4 were designed as acyclic variants of μ-calpain inhibitory chromone and quinolinone derivatives. Of the compounds synthesized, 4c-2, which possesses a 2-methoxymethoxy group at the phenyl ring and a primary amide at the warhead region most potently inhibited μ-calpain (IC₅₀ = 0.34 μM). Our findings suggest that the 4-aryl-4-oxobutanoic acid amide derivatives should be considered as a new family of μ-calpain inhibitors.     

Synthesis and antifungal activity of 1H-pyrrolo[3,2-g]quinoline-4,9-diones and 4,9-dioxo-4,9-dihydro-1H-benzo[f]indoles

1H-Pyrrolo[3,2-g]quinoline-4,9-diones and 4,9-dioxo-4,9-dihydro-1H-benzo[f]indoles were synthesized and tested for in vitro antifungal activity against fungi. Among them tested, many compounds showed good antifungal activity. The results suggest that 1H-pyrrolo[3,2-g]quinoline-4,9-diones and 4,9-dioxo-4,9-dihydro-1H-benzo[f]indoles would be potent antifungal agents.     

ITS2 ribosomal DNA sequence variation of the bumblebee,Bombus ardens (hymenoptera: Apidae)

The bumblebee species,Bombus, is an invaluable natural resource for greenhouse pollination. Low levels of genetic variation ofBombus ardens have been reported in a previous mitochondrial (mt) gene study. In this study, we sequenced the complete internal transcribed spacer 2 (ITS2) of the nuclear rDNA obtained from 100B. ardens individuals collected from several Korean localities, in an effort to assess its usefulness in characterizing the genetic diversity and relationships among populations of B. ardens. The ITS2 sequences ofB. ardens were shown to be longest among known insects, ranging in size from 1,971–1,984 bp. The sequences harbor four duplicated repeats-≈27 bp repeats, ≈20 bp repeats, ≈33 bp repeats, and ≈34 bp repeats-which have never before been reported in other insect ITS2 rDNA. The maximum sequence divergence of 1.01% among 96 sequence types confirmed the applicability of this molecule to the study of intraspecific variation, revealing higher sequence variation as compared to the previously studied mt COI gene. Overall, a very high per generation migration ratio (Nm = 5.83 ≈ infinite) and a very low level of genetic fixation (FST =0 –0.08) were noted to exist among populations ofB. ardens. The high estimation of gene flow among most populations-in particular, between the remote island Ulleungdo and several inland populations-suggest that historical events may be more responsible for the contemporary population structure of B. ardens. The finding of the lowest genetic diversity (π) in the population on Ulleungdo Island (π = 0.007434) may be reflective of a relatively small population size and the geographical isolation of the population as compared with other inland populations.     

Genetic characteristics of 32 autosomal STR loci and its application for identifying a locus in hereditary hearing loss in the Korean population

Microsatellites, short tandem repeats, are useful markers for genetic analysis because of their high frequency of occurrence over the genome, high information content due to variable repeat lengths, and ease of typing. To establish a panel of microsatellite markers useful for genetic studies for hereditary hearing loss in the Korean population, the allele frequencies and heterozygosities of 32 microsatellite markers in 172 unrelated Korean individuals were examined. The heterozygosity values for these markers ranged from 48 to 87%. All the markers except D6S1038 and D14S1034 marker showed PIC values over 0.5. This indicates these markers have a high degree of polymorphism and are randomly distributed in the Korean population. Therefore, the combinations of these STR loci provide a powerful tool to find the candidate loci of a causative gens for non-syndromic hearing loss in the Korean population.     

Induction of growth phase-specific autolysis in <Emphasis Type="Italic">Bacillus subtilis</Emphasis> 168 by growth inhibitors

Growth phase-specific autolysis of Bacillus subtilis by inhibitors of membrane permeability, inhibitors of macromolecule biosynthesis, inhibitors of cell wall biosynthesis and detergents were tested and characterized in glucose limited liquid medium. The minimum autolysin induction concentration (MAIC) of test compounds, which was at least l/20th lower than the conventional autolysis induction concentration, induced autolysis only for cells at the glucose exhaustion point (diauxic point) of the growth phase, while it was not induced for cells at pre- and post-diauxic points. Inhibitors of macromolecule synthesis that are not known for inducing autolysis, such as chloramphenicol, rifampicin, nalidixic acid, and detergents, also induced specific autolysis. Two types of autolysis corresponding to the concentrations of compounds are distinguished: concentration-sensitive and concentration-insensitive types.     

Preliminary estimation of chum salmon stock composition in the Bering Sea and North Pacific Ocean using polymorphic microsatellite DNA markers

Variation at the three microsatellite (ms) DNA loci in chum salmon was applied to estimate preliminarily the stock composition using a conditional maximum likelihood method in more than 700 fish collected from 14 stations in the Bering Sea and adjacent North Pacific Ocean during September 2003. Regional stock assignment accuracy with these msDNA markers was nearly the same as the previous estimation with mitochondrial (mt) DNA for the Japanese and North American stocks, but decreased for Russian stocks. The temporal stock estimation with msDNA gave a nonrandom distribution pattern of chum stocks, in that the Japanese and Russian stocks increased in the western to central Bering Sea, and the North American stocks were abundant in the eastern Bering Sea and near the Aleutian Islands. However, predominance of the North American stocks in nearly all of the surveyed area was different from the previous mtDNA estimation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.