A calix[4]arene-based gelator 1, with lower-rim mono triazolylpyridine group, capable of spontaneous self-assembly into microspheres in different ethanol/H O mixtures, is synthesized. The concentration-dependent H NMR spectra and X-ray single-crystal structure of 1 provided evidence for self-assembly of gelator 1 via cooperative interactions of intermolecular noncovalent forces. Furthermore, metallogels by self-assembly of 1 was found to exhibit remarkable selectivity toward Hg ions.
View Article and Find Full Text PDFCalix[4]arene 1, with two lower-rim isoxazolylchloroanthracene groups, is shown to be not only a chromogenic but also a fluorogenic chemodosimeter for the selective sensing of Cu. The binding properties of ligand 1 and control compounds 2 and 3 toward metal ions in CHCN/CHCl (v/v, 1 : 1) were investigated by UV-vis and fluorescence spectroscopy. The results showed that only ligand 1 was highly selective for Cu ions.
View Article and Find Full Text PDFInterpenetrating porous coordination polymers (IPCPs) consist of two or more networks that are mechanically interlocked to form a coherent structure. The framework topology and the chemical composition are the two important criteria of interpenetrating networks to distinguish homo-IPCPs from hetero-IPCPs. Compared to rich homo-IPCPs, hetero-IPCPs remain rare and are formed rather unexpectedly.
View Article and Find Full Text PDFMultiple-stimuli-responsive photoluminescence films based on a Zn -organic framework, {[Zn (Htpim)(3,4-pydc) ]⋅4 DMF⋅4 H O} (1, Htpim=2,4,5-tri(4-pyridyl)imidazole, 3,4-H pydc=3,4-pyridinedicarboxylic acid), were fabricated. This compound consisted of a 2D corrugated layer, {Zn(3,4-pydc)} , which was further pillared using a Y-shaped pillar N-donor ligand (Htpim) to form a 3D-pillared-layer framework with 1D open channels. The rectangular channels in the as-synthesized compound are fully occupied by guest DMF and H O molecules.
View Article and Find Full Text PDFAn SHG-active noncentrosymmetric (3,4)-connected Zn(ii)-organic framework, {[Zn2(4-abpt)(3,4-pydc)2]·2DMAc·3MeOH·H2O}n (1-Zn), was synthesized using a mixed-ligand system. The 1-Zn framework undergoes metal metathesis, with the complete exchange of the tetrahedrally coordinated ZnII ions with CuII ions while retaining the integrity of the network.
View Article and Find Full Text PDFIn this paper we describe a modified (AEG/CH) coated separator for Li-S batteries in which the shuttling phenomenon of the lithium polysulfides is restrained through two types of interactions: activated expanded graphite (AEG) flakes interacted physically with the lithium polysulfides, while chitosan (CH), used to bind the AEG flakes on the separator, interacted chemically through its abundance of amino and hydroxyl functional groups. Moreover, the AEG flakes facilitated ionic and electronic transfer during the redox reaction. Live H-cell discharging experiments revealed that the modified separator was effective at curbing polysulfide shuttling; moreover, X-ray photoelectron spectroscopy analysis of the cycled separator confirmed the presence of lithium polysulfides in the AEG/CH matrix.
View Article and Find Full Text PDFAim: To test whether a simple animal, (), can be used as an alternative model to study the interaction between hepatitis B virus antigens (HBsAg) and host factors.
Methods: Three plasmids that were able to express the large, middle and small forms of HBsAgs (LHBsAg, MHBsAg, and SHBsAg, respectively) driven by a ubiquitous promoter () and three that were able to express SHBsAg driven by different tissue-specific promoters were constructed and microinjected into worms. The brood size, egg-laying rate, and gonad development of transgenic worms were analyzed using microscopy.
A new 3D tubular zinc phosphite, Zn (C H N ) (HPO ) ⋅H O (1), incorporating a tetradentate organic ligand was synthesized under hydro(solvo)thermal conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 is the first example of inorganic zincophosphite chains being interlinked through 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene to form a tubular porous framework with unusual organic-inorganic hybrid channels. The thermal and chemical stabilities, high capacity for CO adsorption compared to that for N adsorption, and interesting optical properties of LED devices fabricated using this compound were also studied.
View Article and Find Full Text PDFExploiting a C. elegans mutant (ncl-1) exhibiting nucleolar abnormalities, we recently identified the let-7/ncl-1/fib-1 genetic cascade underlying proper rRNA abundance and nucleolar size. These 3 factors, let-7 (a miRNA), NCL-1 (a member of the TRIM-NHL family), and fibrillarin (a nucleolar methyltransferase), are evolutionarily conserved across metazoans.
View Article and Find Full Text PDFRibosome biogenesis takes place in the nucleolus, the size of which is often coordinated with cell growth and development. However, how metazoans control nucleolar size remains largely unknown. Caenorhabditis elegans provides a good model to address this question owing to distinct tissue distribution of nucleolar sizes and a mutant, ncl-1, which exhibits larger nucleoli than wild-type worms.
View Article and Find Full Text PDFA new zinc phosphite exhibited remarkable structural transformations upon heat stimulation to convert into a dehydrated form (NCU-2a) and a new structure, NCU-2b. The gas adsorption properties of the materials as well as the luminescence properties of LED devices fabricated using these materials were also investigated.
View Article and Find Full Text PDFAn organic-inorganic hybrid zinc phosphate with 28-ring channels was synthesized by use of an organic ligand instead of organic amine template under a hydro(solvo)thermal condition. This crystalline zinc phosphate contains large channels constructed from 28 zinc and phosphate tetrahedral units. The walls of the channels consist of two types of zincophosphate chains, in which the Zn atoms are coordinated by 2,4,5-tri(4-pyridyl)-imidazole ligands as pendent groups.
View Article and Find Full Text PDFThe high-yielding self-assembly of three neutral rhenium(I) rectangles, [Re(2)(CO)(6)(L)(bpe)](2) (1 a, L=2,2'-biimidazolate (biim); 1 b, L=2,2'-bisbenzimidazolate (bbim); 1 c, L=2,2'-bis(4,5-dimethylimidazolate) (bdmim); bpe=trans-1,2-bis(4-pyridyl)ethylene), under hydrothermal conditions is described. The rectangles were structurally characterized by spectroscopic techniques and further confirmed by single-crystal X-ray diffraction. Upon irradiation with a Hg lamp at 365 nm, the bpe ligands of rectangles 1 a and 1 b underwent [2+2] photocycloaddition reactions to produce [{(Re(CO)(3))(2)L}(2)(4,4'-tpcb)(2)] (2 a, L=biim; 2 b, L=bbim; 4,4'-tpcb=1,2,3,4-tetrakis(4-pyridyl)cyclobutane) through a single-crystal-to-single-crystal (SCSC) transformation.
View Article and Find Full Text PDFNucleolar size and appearance correlate with ribosome biogenesis and cellular activity. The mechanisms underlying changes in nucleolar appearance and regulation of nucleolar size that occur during differentiation and cell cycle progression are not well understood. Caenorhabditis elegans provides a good model for studying these processes because of its small size and transparent body, well-characterized cell types and lineages, and because its cells display various sizes of nucleoli.
View Article and Find Full Text PDFFront Biosci (Elite Ed)
January 2011
Caenorhabditis elegans is a model organism that has been used to study human bacterial and viral pathogenesis. We report here the expression of human hepatitis delta viral antigens (HDAg) in C. elegans and measure the effect on the sterility, growth, and brood size in transgenic worms.
View Article and Find Full Text PDFWe report on a series of new self-assembled cyclometalated dirhenium(I) metallacyclic complexes via an unprecedented rhenium-mediated C-H bond activation and the relationship between their structures and luminescence properties.
View Article and Find Full Text PDFTo meet the increasing need of simultaneously co-expressing two different genes in the same cell of transgenic Caenorhabditis elegans, here, we report the establishment of dicistronic vectors that contain an intercistronic region (ICR) of the C. elegans operon, CEOP5428. In these vectors, a green fluorescence protein (GFP) and a red FP (RFP) genes were placed in the first and second cistrons, respectively, which were separated by the ICR.
View Article and Find Full Text PDFIn bacteria and archaea, many functionally related genes are organized into operons in order to be transcribed and translated simultaneously. Operons are rarely seen in eukaryotes except for the Trypanosome and nematode, in which they are first transcribed into polycistronic transcripts but then processed into individual mature mRNAs. Recently, several researchers described the findings of polycistronic transcripts also in insects, which revised the previous thoughts that polycistronic genes were absent or few in eukaryotes.
View Article and Find Full Text PDFBackground: Congenital adrenal hyperplasia (CAH) is a syndrome of prenatal and/or postnatal androgen excess secondary to genetic deficits in the cytochrome p450 enzymes of the cortisol synthesis pathway. Women with CAH may suffer from different degrees of androgenization. This study documented psychiatric manifestations in young women born with CAH in Taiwan.
View Article and Find Full Text PDFAims: The purpose of this study was to explore the concepts and processes for successful abstinence from alcohol for Taiwanese Alcoholics Anonymous members.
Background: Attempting to identify the psychological and social influences upon alcohol consumption remission outside of alcoholism treatment could help professionals to engage in a broad array of community interventions in an informed fashion.
Methods: Grounded theory method was utilized in this study.
Internal control beliefs appear to be important factors in recovery from alcoholism. However, no instrument for assessing drinking-related locus of control has been developed in Taiwan. After translating the drinking-related locus-of-control scale (DRIE) into Chinese, we examined the psychometric properties of the Chinese version of the DRIE in alcohol-dependent patients.
View Article and Find Full Text PDFBackground: Orthognathic surgery has been increasingly performed in the authors' country. To ascertain the increased satisfaction that comes with surgery, it is necessary to evaluate the patient's motivation for surgery.
Methods: Seventy-four female patients were evaluated before surgery.
Aflatoxins are highly toxic and carcinogenic fungal secondary metabolites. At least 18 enzyme activities are required for aflatoxin biosynthesis in the filamentous fungus Aspergillus parasiticus. One of these enzymes, versicolorin B synthase (VBS), catalyzes bisfuran ring closure in versiconal hemiacetal (a reaction near the middle of the pathway) to form versicolorin B.
View Article and Find Full Text PDFThe biosynthesis of aflatoxin in Aspergillus parasiticus is a complex process that involves the activities of at least 18 pathway enzymes. The distribution of these enzymes within fungal colonies and fungal cells is not clearly understood. The objective of this study was to investigate the distribution and subcellular location of Nor-1, Ver-1, and OmtA, which represent early, middle, and late enzymatic activities, respectively, in the aflatoxin biosynthetic pathway.
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