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1.
Mol Phylogenet Evol ; 81: 182-94, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25238947

ABSTRACT

Bitterlings are relatively small cypriniform species and extremely interesting evolutionarily due to their unusual reproductive behaviors and their coevolutionary relationships with freshwater mussels. As a group, they have attracted a great deal of attention in biological studies. Understanding the origin and evolution of their mating system demands a well-corroborated hypothesis of their evolutionary relationships. In this study, we provide the most comprehensive phylogenetic reconstruction of species relationships of the group based on partitioned maximum likelihood and Bayesian methods using DNA sequence variation of nuclear and mitochondrial genes on 41 species, several subspecies and three undescribed species. Our findings support the monophyly of the Acheilognathidae. Two of the three currently recognized genera are not monophyletic and the family can be subdivided into six clades. These clades are further regarded as genera based on both their phylogenetic relationships and a reappraisal of morphological characters. We present a revised classification for the Acheilognathidae with five genera/lineages: Rhodeus, Acheilognathus (new constitution), Tanakia (new constitution), Paratanakia gen. nov., and Pseudorhodeus gen. nov. and an unnamed clade containing five species currently referred to as "Acheilognathus". Gene trees of several bitterling species indicate that the taxa are not monophyletic. This result highlights a potentially dramatic underestimation of species diversity in this family. Using our new phylogenetic framework, we discuss the evolution of the Acheilognathidae relative to classification, taxonomy and biogeography.


Subject(s)
Biological Evolution , Cyprinidae/classification , Phylogeny , Animals , Bayes Theorem , Cyprinidae/genetics , Genes, Mitochondrial , Genetic Variation , Likelihood Functions , Sequence Analysis, DNA
2.
ACS Appl Mater Interfaces ; 11(24): 21634-21644, 2019 Jun 19.
Article in English | MEDLINE | ID: mdl-31135125

ABSTRACT

The electrocatalyst comprising two different metal atoms is found suitable for overall water splitting in alkaline medium. Hydrothermal synthesis is an extensively used technique for the synthesis of various metal sulfides. Time-dependent diffusion of the constituting ions during hydrothermal synthesis can affect the crystal and electronic structure of the product, which in turn would modulate its electrocatalytic activity. Herein, cobalt molybdenum bimetallic sulfide was prepared via hydrothermal method after varying the duration of reaction. The change in crystal structure, amount of Co-S-Mo moiety, and electronic structure of the synthesized materials were thoroughly investigated using different analytical techniques. These changes modulated the charge transfer at the electrode-electrolyte interface, as evidenced by electrochemical impedance spectroscopy. The Tafel plots for the prepared materials were investigated considering a less explored approach and it was found that different materials facilitated different electrocatalytic pathways. The product obtained after 12 h reaction showed superior catalytic activity in comparison to the products obtained from 4, 8, and 16 h reaction, and it surpassed the overall water splitting activity of the RuO2-Pt/C couple. This study demonstrated the ion diffusion within the bimetallic sulfide during hydrothermal synthesis and change in its electrocatalytic activity due to ion diffusion.

3.
ACS Appl Mater Interfaces ; 10(33): 27712-27722, 2018 Aug 22.
Article in English | MEDLINE | ID: mdl-30044090

ABSTRACT

Fabrication of high-performance noble-metal-free bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water is a promising strategy toward future carbon-neutral economy. Herein, a one-pot hydrothermal synthesis of cobalt sulfide/nickel sulfide heterostructure supported by nickel foam (CoS x/Ni3S2@NF) was performed. The Ni foam acted as the three-dimensional conducting substrate as well as the source of nickel for Ni3S2. The formation of CoS x/Ni3S2@NF was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. The formation of CoS x/Ni3S2@NF facilitated easy charge transport and showed synergistic electrocatalytic effect toward HER, OER, and overall water splitting in alkaline medium. Remarkably, CoS x/Ni3S2@NF showed catalytic activity comparable with that of benchmarking electrocatalysts Pt/C and RuO2. For CoS x/Ni3S2@NF, overpotentials of 204 and 280 mV were required to achieve current densities of 10 and 20 mA cm-2 for HER and OER, respectively, in 1.0 M KOH solution. A two-electrode system was formulated for overall water splitting reaction, which showed current densities of 10 and 50 mA cm-2 at 1.572 and 1.684 V, respectively. The prepared catalyst exhibited excellent durability in HER and OER catalyzing conditions and also in overall water splitting operation. Therefore, CoS x/Ni3S2@NF could be a promising noble-metal-free electrocatalyst for overall water splitting application.

4.
ACS Appl Mater Interfaces ; 7(26): 14211-22, 2015 Jul 08.
Article in English | MEDLINE | ID: mdl-26068665

ABSTRACT

Nanostructured hexagonal boron nitride (h-BN)/reduced graphene oxide (RGO) composite is prepared by insertion of h-BN into the graphene oxide through hydrothermal reaction. Formation of the super lattice is confirmed by the existence of two separate UV-visible absorption edges corresponding to two different band gaps. The composite materials show enhanced electrical conductivity as compared to the bulk h-BN. A high specific capacitance of ∼824 F g(-1) is achieved at a current density of 4 A g(-1) for the composite in three-electrode electrochemical measurement. The potential window of the composite electrode lies in the range from -0.1 to 0.5 V in 6 M aqueous KOH electrolyte. The operating voltage is increased to 1.4 V in asymmetric supercapacitor (ASC) device where the thermally reduced graphene oxide is used as the negative electrode and the h-BN/RGO composite as the positive electrode. The ASC exhibits a specific capacitance of 145.7 F g(-1) at a current density of 6 A g(-1) and high energy density of 39.6 W h kg(-1) corresponding to a large power density of ∼4200 W kg(-1). Therefore, a facile hydrothermal route is demonstrated for the first time to utilize h-BN-based composite materials as energy storage electrode materials for supercapacitor applications.

5.
Clin Chim Acta ; 322(1-2): 149-56, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12104094

ABSTRACT

BACKGROUND: CancerB (CCB, IMSF-5), herbal combination, may be able to stimulate potential toxic mediators such as nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) in isolated mouse peritoneal macrophages. METHODS: NO production was determined by Griess method, and TNF-alpha production by enzyme-linked immunosorbent assay. Amounts of proteins were observed by Western blotting. RESULTS: CCB had no effect on NO production by itself, but CCB alone did stimulate the production of TNF-alpha. When CCB was used in combination with recombinant interferon-gamma (rIFN-gamma), there was a marked cooperative induction of NO production, TNF-alpha production and NF-kappa B activation. The increase in NO synthesis was reflected as an increased amount of inducible NO synthase protein. The increased production of NO from rIFN-gamma plus CCB-stimulated peritoneal macrophages was decreased by the treatment with N(G)-monomethyl-L-arginine or N(alpha)-Tosyl-Phe Chloromethyl Ketone. Nuclear factor-kappa B (NF-kappa B) inhibitor, pyrrolidine dithiocarbamate was able to completely inhibit the production of NO and TNF-alpha. CONCLUSIONS: These findings demonstrate that CCB increases the production of NO and TNF-alpha by rIFN-gamma-primed peritoneal macrophages and suggest that NF-kappa B plays a critical role in mediating these effects of CCB.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Drugs, Chinese Herbal/pharmacology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/metabolism , Nitric Oxide/metabolism , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Herbal Medicine , Interferon-gamma/pharmacology , Medicine, East Asian Traditional , Mice , NF-kappa B/metabolism , Nitric Oxide Synthase/metabolism , Pyrrolidines/pharmacology , Recombinant Proteins , Thiocarbamates/pharmacology , Tosylphenylalanyl Chloromethyl Ketone/pharmacology , omega-N-Methylarginine/pharmacology
6.
J Med Entomol ; 41(3): 447-55, 2004 May.
Article in English | MEDLINE | ID: mdl-15185949

ABSTRACT

Genetically altering the disease vector status of insects using recombinant DNA technologies is being considered as an alternative to eradication efforts. Manipulating the endogenous immune response of mosquitoes such as the temporal and special expression of antimicrobial peptides like cecropin may result in a refractory phenotype. Using transgenic technology a unique pattern of expression of cecropin A (cecA) in Anopheles gambiae was created such that cecA was expressed beginning 24 h after a blood meal in the posterior midgut. Two independent lines of transgenic An. gambiae were created using a piggyBac gene vector containing the An. gambiae cecA cDNA under the regulatory control of the Aedes aegypti carboxypeptidase promoter. Infection with Plasmodium berghei resulted in a 60% reduction in the number of oocysts in transgenic mosquitoes compared with nontransgenic mosquitoes. Manipulating the innate immune system of mosquitoes can negatively affect their capacity to serve as hosts for the development of disease-causing microbes.


Subject(s)
Anopheles/genetics , Anopheles/parasitology , Antimicrobial Cationic Peptides/genetics , Plasmodium/parasitology , Animals , Animals, Genetically Modified , Base Sequence , DNA Primers , DNA Transposable Elements , Genetic Predisposition to Disease , Humans , Insect Hormones/genetics , Mutagenesis, Insertional , Polymerase Chain Reaction , Restriction Mapping
7.
Mol Cells ; 30(6): 507-12, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21110132

ABSTRACT

In this study, we applied DNA barcoding to identify species using short DNA sequence analysis. We examined the utility of DNA barcoding by identifying 53 Korean freshwater fish species, 233 other freshwater fish species, and 1339 saltwater fish species. We successfully developed a web-based molecular identification system for fish (MISF) using a profile hidden Markov model. MISF facilitates efficient and reliable species identification, overcoming the limitations of conventional taxonomic approaches. MISF is freely accessible at http://bioinfosys.snu.ac.kr:8080/MISF/misf.jsp .


Subject(s)
DNA Barcoding, Taxonomic/methods , DNA, Mitochondrial/genetics , Databases, Genetic , Fishes/classification , Fishes/genetics , Animals , Computational Biology , DNA/genetics , DNA Probes/genetics , Electronic Data Processing/methods , Phylogeny , Sequence Analysis, DNA/methods , Species Specificity
8.
Mol Cells ; 27(6): 629-34, 2009 Jun 30.
Article in English | MEDLINE | ID: mdl-19533032

ABSTRACT

G protein-coupled receptors (GPCRs) are part of multi-protein networks called 'receptosomes'. These GPCR interacting proteins (GIPs) in the receptosomes control the targeting, trafficking and signaling of GPCRs. PDZ domain proteins constitute the largest protein family among the GIPs, and the predominant function of the PDZ domain proteins is to assemble signaling pathway components into close proximity by recognition of the last four C-terminal amino acids of GPCRs. We present here a machine learning based approach for the identification of GPCR-binding PDZ domain proteins. In order to characterize the network of interactions between amino acid residues that contribute to the stability of the PDZ domain-ligand complex and to encode the complex into a feature vector, amino acid contact matrices and physicochemical distance matrix were constructed and adopted. This novel machine learning based method displayed high performance for the identification of PDZ domain-ligand interactions and allowed the identification of novel GPCR-PDZ domain protein interactions.


Subject(s)
Artificial Intelligence , Computational Biology/methods , PDZ Domains , Receptors, G-Protein-Coupled/metabolism , Amino Acid Sequence , Models, Molecular , Molecular Sequence Data , Protein Binding
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