A novel esterase from Paenibacillus sp. PBS-2 is a new member of the β-lactamase belonging to the family VIII lipases/esterases

Screening of a gene library from Paenibacillus sp. PBS-2 generated in Escherichia coli led to the identification of a clone with lipolytic activity. Sequence analysis showed an open reading frame encoding a polypeptide of 378 amino acid residues with a predicted molecular mass of 42 kDa. The esterase displayed 69% and 42% identity with the putative β-lactamases from Paenibacillus sp. JDR-2 and Clostridium sp. BNL1100, respectively. The esterase contained a Serx- x-Lys motif that is conserved among all β-lactamases found to date. The protein PBS-2 was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at 18°C. The enzyme is a serine protein and was active against p-nitrophenyl esters of C2, C4, C8, and C10. The optimum pH and temperature for enzyme activity were pH 9.0 and 30°C, respectively. Relative activity of 55% remained at up to 5°C with an activation energy of 5.84 kcal/mol, which indicates that the enzyme is cold-adapted. Enzyme activity was inhibited by Cd(2+), Cu(2+), and Hg(2+) ions. As expected for a serine esterase, activity was inhibited by phenylmethylsulfonyl fluoride. The enzyme was remarkably active and stable in the presence of commercial detergents and organic solvents. This cold-adapted esterase has potential as a biocatalyst and detergent additive for use at low temperatures.

Functional analysis of Pacific oyster (Crassostrea gigas) β-thymosin: Focus on antimicrobial activity

An antimicrobial peptide, ∼5 kDa in size, was isolated and purified in its active form from the mantle of the Pacific oyster Crassostrea gigas by C18 reversed-phase high-performance liquid chromatography. Matrix-assisted laser desorption ionisation time-of-flight analysis revealed 4656.4 Da of the purified and unreduced peptide. A comparison of the N-terminal amino acid sequence of oyster antimicrobial peptide with deduced amino acid sequences in our local expressed sequence tag (EST) database of C. gigas (unpublished data) revealed that the oyster antimicrobial peptide sequence entirely matched the deduced amino acid sequence of an EST clone (HM-8_A04), which was highly homologous with the β-thymosin of other species. The cDNA possessed a 126-bp open reading frame that encoded a protein of 41 amino acids. To confirm the antimicrobial activity of C. gigas β-thymosin, we overexpressed a recombinant β-thymosin (rcgTβ) using a pET22 expression plasmid in an Escherichia coli system. The antimicrobial activity of rcgTβ was evaluated and demonstrated using a bacterial growth inhibition test in both liquid and solid cultures.

Fish Myogenic Regulatory Protein LUC7L: Characterization and Expression Analysis in Korean Rose Bitterling (Rhodeus uyekii)

Serine-arginine-rich nuclear protein LUC7L plays an important role in the regulation of myogenesis in mice. In the present study, we isolated and characterized the Korean rose bitterling Rhodeus uyekii Luc7l cDNA, designated RuLuc7l. The RuLuc7l cDNA is 1,688 bp long and encodes a 364-amino-acid polypeptide containing serine/arginine-rich region at the C-terminus. The deduced RuLuc7l protein has high amino acid identity (71-97%) with those of other species including human. Phylogenetic analysis revealed that RuLUC7L clustered with fish LUC7L proteins. The expression of RuLuc7l mRNA was high in the brain, kidney, and stomach of Korean rose bitterling. Expression of the RuLuc7l mRNA was detected from 1 day post-fertilization (dpf) and moderately increased until 21 dpf during the early development. Further investigations are required to elucidate the functional role of RuLUC7L in myogenesis in R. uyekii.

Polymer composite electrolytes having core-shell silica fillers with anion-trapping boron moiety in the shell layer for all-solid-state lithium-ion batteries

Core-shell silica particles with ion-conducting poly(ethylene glycol) and anion-trapping boron moiety in the shell layer were prepared to be used as fillers for polymer composite electrolytes based on organic/inorganic hybrid branched copolymer as polymer matrix for all-solid-state lithium-ion battery applications. The core-shell silica particles were found to improve mechanical strength and thermal stability of the polymer matrix and poly(ethylene glycol) and boron moiety in the shell layer increase compatibility between filler and polymer matrix. Furthermore, boron moiety in the shell layer increases both ionic conductivity and lithium transference number of the polymer matrix because lithium salt can be more easily dissociated by the anion-trapping boron. Interfacial compatibility with lithium metal anode is also improved because well-dispersed silica particles serve as protective layer against interfacial side reactions. As a result, all-solid-state battery performance was found to be enhanced when the copolymer having core-shell silica particles with the boron moiety was used as solid polymer electrolyte.

Living Vinyl Addition Polymerization of Substituted Norbornenes by a t-Bu3P-Ligated Methylpalladium Complex

The vinyl addition polymerization of substituted norbornene (NB) monomers, via (t-Bu₃P)PdMeCl activated by [Li(OEt₂)_2.5]B(C₆F₅)₄, is investigated. NB monomers bearing alkyl, aryl, fluoroaryl, and even hexafluoroisopropanol substituents yield polymers exhibiting monomodal and narrow molecular weight distributions, with molecular weight controlled by reaction time and monomer to initiator ratio, demonstrating the living nature of these polymerizations. These polymers are soluble in common organic solvents and possess excellent thermal stability. Block copolymers are also prepared via sequential monomer addition; these are the first examples of well-defined block copolymers of substituted NB monomers enchained by vinyl addition polymerization.

Crystal structure of YwpF from Staphylococcus aureus reveals its architecture comprised of a β-barrel core domain resembling type VI secretion system proteins and a two-helix pair

The ywpF gene (SAV2097) of the Staphylococcus aureus strain Mu50 encodes the YwpF protein, which may play a role in antibiotic resistance. Here, we report the first crystal structure of the YwpF superfamily from S. aureus at 2.5-Å resolution. The YwpF structure consists of two regions: an N-terminal core β-barrel domain that shows structural similarity to type VI secretion system (T6SS) proteins (e.g., Hcp1, Hcp3, and EvpC) and a C-terminal two-helix pair. Although the monomer structure of S. aureus YwpF resembles those of T6SS proteins, the dimer/tetramer model of S. aureus YwpF is distinct from the functionally important hexameric ring of T6SS proteins. We therefore suggest that the S. aureus YwpF may have a different function compared to T6SS proteins.

Mussel-inspired dopamine- and plant-based cardanol-containing polymer coatings for multifunctional filtration membranes

A series of copolymers [PCD#s, where # is the weight percentage of dopamine methacrylamide (DMA) in polymers] containing mussel-inspired hydrophilic dopamine and plant-based hydrophobic cardanol moieties was prepared via radical polymerization using DMA and 2-hydroxy-3-cardanylpropyl methacrylate (HCPM) as the monomers. PCD#s were used as coating materials to prevent flux decline of the membranes caused by the adhesion of biofoulants and oil-foulants. Polysulfone (PSf) ultrafiltration membranes coated with PCD#s showed higher biofouling resistance than the bare PSf membrane, and the bactericidal properties of the membranes increased upon increasing the content of HCPM units in the PCD#s. Serendipitously, the PSf membranes coated with the more or less amphiphilic PCD54 and PCD74, having the optimum amount of both hydrophilic DMA and hydrophobic HCPM moieties, showed noticeably higher oil-fouling resistance than the more hydrophilic PCD91-coated membrane, the more hydrophobic PCD0-coated membrane, and the bare PSf membrane. Therefore, multifunctional coating materials having biofouling- and oil-fouling-resistant and bactericidal properties could be prepared from the monomers containing mussel-inspired dopamine and plant-based cardanol groups.

The factors affecting pain pattern after arthroscopic rotator cuff repair

Background

We evaluated the factors that affect pain pattern after arthroscopic rotator cuff repair.

Methods

From June 2009 to October 2010, 210 patients underwent arthroscopic rotator cuff repair operations. Of them, 84 patients were enrolled as subjects of the present study. The evaluation of postoperative pain was conducted by visual analog scale (VAS) scores during postoperative outpatient interviews at 6 weeks, 3 months, 6 months, and 12 months. The factors that were thought to affect postoperative pain were evaluated by dividing into three categories: preoperative, operative, and postoperative.

Results

Pain after arthroscopic rotator cuff repair surgery showed a strictly decreasing pain pattern. In single analysis and multiple regression tests for factors influencing the strictly decreasing pain pattern, initial VAS and pain onset were shown to be statistically significant factors (p = 0.012, 0.012, 0.044 and 0.028, respectively). With regard to the factors influencing lower than average intensity pain pattern for each period, the stiffness of internal rotation at 3 months postoperatively was shown to be a statistically significant factor in single and multiple regression tests (p = 0.017 and p = 0.004, respectively).

Conclusions

High initial VAS scores and the acute onset of pain affected the strictly decreasing postoperative pain pattern. Additionally, stiffness of internal rotation at postoperative 3 months affected the higher than average intensity pain pattern for each period after arthroscopic rotator cuff repair.

Pseudopelagicola gijangensis gen. nov., sp. nov., isolated from the sea squirt Halocynthia roretzi

A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterial strain, designated YSS-7T, was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea of South Korea. Strain YSS-7T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain YSS-7T clustered with the type strains of Pelagicola litoralis , Planktotalea frisia , Pacificibacter maritimus and Roseovarius marinus . Strain YSS-7T exhibited the highest 16S rRNA gene sequence similarity (97.7 %) to the type strain of Pelagicola litoralis and sequence similarity of more than 96.0 % to the type strains of some other species. Strain YSS-7T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c and 11-methyl C18 : 1ω7c as the major fatty acids. The major polar lipids of strain YSS-7T were phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid and an unidentified lipid. The fatty acid and polar lipid profiles of strain YSS-7T were different from those of the type strains of phylogenetically related species. The DNA G+C content of strain YSS-7T was 55.5 mol%. Other phenotypic properties demonstrated that strain YSS-7T is distinguished from phylogenetically related species. On the basis of the data presented, strain YSS-7T is considered to represent a novel genus and species, for which the name Pseudopelagicola gijangensis gen. nov., sp. nov. is proposed. The type strain of Pseudopelagicola gijangensis is YSS-7T ( = KCTC 42049T = CECT 8540T).

Collision Avoidance in Multiple-Ship Situations by Distributed Local Search

As vital transportation carriers in trade, ships have the advantage of stability, economy, and bulk capacity over airplanes, trucks, and trains. Even so, their loss and cost due to collisions and other accidents exceed those of any other mode of transportation. To prevent ship collisions many ways have been suggested, e.g., the 1972 COLREGs which is the regulation for preventing collision between ships. Technologically speaking, many related studies have been conducted. The term “Ship domain” involves that area surrounding a ship that the navigator wants to keep other ships clear of. Ship domain alone is not sufficient, however, for enabling one or more ships to simultaneously determine the collision risk for all of the ships concerned. Fuzzy theory is useful in helping ships avoid collision in that fuzzy theory may define whether collision risk is based on distance to closest point of approach, time to closest point of approach, or relative bearing – algorithms that are difficult to apply to more than one ships at one time. The main purpose of this study is thus to reduce collision risk among multiple ships using a distributed local search algorithm (DLSA). By exchanging information on, for example, next-intended courses within a certain area among ships, ships having the maximum reduction in collision risk change courses simultaneously until all ships approach a destination without collision. In this paper, we introduce distributed local search and explain how it works using examples. We conducted experiments to test distributed local search performance for certain instances of ship collision avoidance. Experiments results showed that in most cases, our proposal applies well in ship collision avoidance amongmultiple ships.

Removal of road deposited sediments by sweeping and its contribution to highway runoff quality in Korea

Highway runoff is known to be an important non-point source (NPS), increasing the load of pollutants in receiving water. For reducing NPS pollutants in runoff, removal of road deposited sediment (RDS) by sweeping is considered effective. However, the contribution of sweeping to the improvement of runoff quality has not been clearly and quantitatively demonstrated so far. In this study, a field test was carried out on a section of operating highway in Korea to investigate the effectiveness of sweeping on improving the quality of highway runoff. Results showed that the average reduction in the load of RDS by sweeping was 61.10% with a standard deviation of 1.74%. RDS removal efficiency decreased when the sweeping speed increased from 4-8 to 20 km h(-1), the load decreased from 12.5 to 1.25 g m(-2) and particle size decreased from sand to silt/clay size ranges. Runoff was induced by applying a 15 mm h(-1) artificial rainfall to both swept and non-swept sections. Analysis of runoff quality showed that the event mean concentrations of total suspended solid, biological oxygen demand, chemical oxygen demand, nutrients and most of the heavy metals were reduced by 31-87% after sweeping. In addition, field tests for RDS build-up indicated a sweeping frequency of once every four or five days to prevent re-suspension of RDS. The results of this study suggest that sweeping can be the best management practice for effectively reducing RDS on highways and improving the quality of highway runoff.

Description of Lutimonas halocynthiae sp. nov., isolated from a golden sea squirt (Halocynthia aurantium), reclassification of Aestuariicola saemankumensis as Lutimonas saemankumensis comb. nov. and emended description of the genus Lutimonas

A Gram-stain-negative, non-motile, coccoid, ovoid or rod-shaped bacterial strain, designated RSS3-C1T, was isolated from a golden sea squirt (Halocynthia aurantium) collected from the East Sea, South Korea. Strain RSS3-C1T was found to grow optimally at 20–25 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain RSS3-C1T clustered with the type strains of Lutimonas vermicola and Aestuariicola saemankumensis . Strain RSS3-C1T exhibited 98.8 % 16S rRNA gene sequence similarity to each type strain. Strain RSS3-C1T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C17 : 0 3-OH and anteiso-C15 : 0 as the major fatty acids. The major polar lipids of strain RSS3-C1T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain RSS3-C1T was 39.2 mol%, and DNA–DNA relatedness to the type strains of and was 21±5.3 and 26±7.5 %, respectively. The differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain RSS3-C1T is separated from and . On the basis of the data presented, strain RSS3-C1T is considered to represent a novel species of the genus Lutimonas , for which the name Lutimonas halocynthiae sp. nov. is proposed. The type strain is RSS3-C1T ( = KCTC 32537T = CECT 8444T). In this study, it is also proposed that Aestuariicola saemankumensis should be reclassified as a member of the genus Lutimonas , as Lutimonas saemankumensis comb. nov. (type strain SMK-142T = KCTC 22171T = CCUG 55329T), and the description of the genus Lutimonas is emended.

Litoreibacter ascidiaceicola sp. nov., isolated from the golden sea squirt Halocynthia aurantium

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated RSS4-C1(T), was isolated from a golden sea squirt (Halocynthia aurantium) collected from the East Sea, South Korea. The novel strain grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 1.0-3.0% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain RSS4-C1(T) fell within the clade comprising the type strains of species of the genus Litoreibacter . Strain RSS4-C1(T) exhibited the highest 16S rRNA gene sequence similarity (99.6%) to the type strain of Litoreibacter albidus and sequence similarities of 96.5-98.5% to type strains of other recognized species of the genus Litoreibacter. Strain RSS4-C1(T) contained Q-10 as the predominant ubiquinone and C(18 : 1)ω7c and 11-methyl-C(18 : 1)ω7c as the major fatty acids. The major polar lipids of strain RSS4-C1(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid and one unidentified aminolipid. The DNA G+C content of strain RSS4-C1(T) was 58.0 mol% and its DNA-DNA relatedness values with type strains of four species of the genus Litoreibacter were 21-34%. The differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain RSS4-C1(T) is distinct from other species of the genus Litoreibacter. On the basis of the data presented, strain RSS4-C1(T) is considered to represent a novel species of the genus Litoreibacter, for which the name Litoreibacter ascidiaceicola sp. nov. is proposed. The type strain is RSS4-C1(T) ( = KCTC 42050(T) = CECT 8539(T)).

High-performance reverse osmosis CNT/polyamide nanocomposite membrane by controlled interfacial interactions

Polyamide reverse osmosis (RO) membranes with carbon nanotubes (CNTs) are prepared by interfacial polymerization using trimesoyl chloride (TMC) solutions in n-hexane and aqueous solutions of m-phenylenediamine (MPD) containing functionalized CNTs. The functionalized CNTs are prepared by the reactions of pristine CNTs with acid mixture (sulfuric acid and nitric acid of 3:1 volume ratio) by varying amounts of acid, reaction temperature, and reaction time. CNTs prepared by an optimized reaction condition are found to be well-dispersed in the polyamide layer, which is confirmed from atomic force microscopy, scanning electron microscopy, and Raman spectroscopy studies. The polyamide RO membranes containing well-dispersed CNTs exhibit larger water flux values than polyamide membrane prepared without any CNTs, although the salt rejection values of these membranes are close. Furthermore, the durability and chemical resistance against NaCl solutions of the membranes containing CNTs are found to be improved compared with those of the membrane without CNTs. The high membrane performance (high water flux and salt rejection) and the improved stability of the polyamide membranes containing CNTs are ascribed to the hydrophobic nanochannels of CNTs and well-dispersed states in the polyamide layers formed through the interactions between CNTs and polyamide in the active layers.

Complete mitochondrial genome of Pacific abalone (Haliotis discus hannai) from Korea

We have sequenced and characterized the complete mitochondrial DNA of an economically and ecologically important Pacific abalone, Haliotis discus hannai (Haliotidae, Gastropoda). The mitogenome of the Pacific abalone is 16,886 nt total length with a 39.6% G+C composition. Thirty-seven genes were identified including 13 protein-coding, 2 rRNA and 22 tRNA genes. We compared the mitogenome of the Pacific abalone to a putative relative species, H. rubra.

Synthesis and properties of organic/inorganic hybrid branched-graft copolymers and their application to solid-state electrolytes for high-temperature lithium-ion batteries

A series of organic/inorganic hybrid branched-graft copolymers (BCPs) were synthesized via RAFT polymerization for application to solid polymer electrolyte materials in high-temperature lithium-ion batteries.