69 research outputs found

    SYNTHESES AND PROPERTIES OF COPPER HYDROXIDE NANOSHEETS AND CONTROLLED DEPOSITION

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    In this study, we synthesized copper hydroxide nanosheet and investigated its electrochemical property and how to deposit it with a uniform amount. The precursor of the nanosheet was a layered copper hydroxide synthesized by the ion exchange of dodecylbenzene sulfonate with acetate in Cu2(OH)3(CH3COO)Ā·H2O. The nanosheet was prepared by delamination of the layered copper hydroxide by dispersion in 1-butanol. Atomic force microscopy images of the nanosheets showed lateral dimensions of ca. 2 Ī¼m with the height of ca. 4.5 nm. Cyclic voltammogram of the nanosheet in basic solution showed two cathodic peaks and two anodic peaks similar to copper oxide electrode. To deposit the nanosheet, a quartz glass slide was dipped in the dispersion of the nanosheet in 1-butanol and dried after washing. This procedure was repeated and the ultraviolet and visible light absorption spectrum of the slide was measured. The absorbance of the slide increased in direct proportion to the number of times of the dip-and-dry procedure. Thus we confirmed that controlled amount of nanosheet was deposited on the quartz glass

    A case of biopsy-proven cardiac sarcoidosis without any other extracardiac manifestations

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    SummaryA 49-year-old woman was referred to our hospital for uncontrollable heart failure. She had never been diagnosed as having sarcoidosis. Chest X-ray showed cardiomegaly without bilateral hilar lymphadenopathy. Echocardiography showed diffuse hypokinesis of the left ventricle mimicking idiopathic dilated cardiomyopathy. No specific manifestations implying sarcoidosis were observed. On cardiac catheterization, coronary angiograms were normal, whereas concurrent routine endomyocardial biopsy showed foci of non-caseating granuloma, indicating sarcoidosis. Pathological finding was the only clue to diagnose cardiac sarcoidosis among our standard examinations for heart failure. No other additional investigations found any extracardiac features of sarcoidosis. All serological and immunological examinations were within normal range. This is a challenging case of biopsy-proven cardiac sarcoidosis without any other extracardiac involvement

    Single crystal growths and magnetic properties of hexagonal polar semimetals RAuGe (R = Y, Gd-Tm, and Lu)

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    We study structural and magnetic properties of rare-earth based semimetals RAuGe (R = Y, Gd-Tm, and Lu) using flux-grown single crystals. These compounds belong to the noncentrosymmetric polar space group P63mc. We confirm the systematic structural evolution at room temperature as a function of ionic radius of rare earths to clarify the isopointal crossover between two polar structures: three-dimensional LiGaGe-type and quasi-two-dimensional NdPtSb-type. Magnetism shows a characteristic anisotropy in reasonable agreement with the crystal electric field (CEF) theory; the easy-plane-type anisotropy for R = Tb and Dy turns into the Ising-type anisotropy for R = Er and Tm. We evaluate the CEF parameters based on the Stevens operators to reasonably reproduce the temperature dependence of magnetic susceptibilities and specific heat for RAuGe (R = Tb-Tm). The estimated energy scale of the Ising gap (~ 11 meV) in TmAuGe is consistent with an excitation observed in an inelastic neutron scattering experiment. These findings suggest an opportunity for interplay between conduction electrons and nontrivial spin structures in the family of magnetic polar semimetals RAuGe.Comment: 10 pages, 7 figures, 1 tabl

    Protein kinase C (Pkc)-Ī“ mediates arginine-induced glucagon secretion in pancreatic Ī±-cells

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    The pathophysiology of type 2 diabetes involves insulin and glucagon. Protein kinase C (Pkc)-Ī“, a serine-threonine kinase, is ubiquitously expressed and involved in regulating cell death and proliferation. However, the role of PkcĪ“ in regulating glucagon secretion in pancreatic Ī±-cells remains unclear. Therefore, this study aimed to elucidate the physiological role of PkcĪ“ in glucagon secretion from pancreatic Ī±-cells. Glucagon secretions were investigated in PkcĪ“-knockdown InR1G9 cells and pancreatic Ī±-cell-specific PkcĪ“-knockout (Ī±PkcĪ“KO) mice. Knockdown of PkcĪ“ in the glucagon-secreting cell line InR1G9 cells reduced glucagon secretion. The basic amino acid arginine enhances glucagon secretion via voltage-dependent calcium channels (VDCC). Furthermore, we showed that arginine increased PkcĪ“ phosphorylation at Th

    Sex-inducing effects toward planarians widely present among parasitic flatworms

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    Summary Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.journal articl

    Decrease in p3-Alcb37 and p3-Alcb40, products of Alcadein b generated by g-secretase cleavages, in aged monkeys and patients with Alzheimerā€™s disease

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    Introduction Neuronal p3-AlcĪ² peptides are generated from the precursor protein Alcadein Ī² (AlcĪ²) through cleavage by Ī±- and Ī³-secretases of the amyloid Ī² (AĪ²) protein precursor (APP). To reveal whether p3-AlcĪ² is involved in Alzheimer\u27s disease (AD) contributes for the development of novel therapy and/or drug targets. Methods We developed new sandwich enzyme-linked immunosorbent assay (sELISA) systems to quantitate levels of p3-AlcĪ² in the cerebrospinal fluid (CSF). Results In monkeys, CSF p3-AlcĪ² decreases with age, and the aging is also accompanied by decreased brain expression of AlcĪ². In humans, CSF p3-AlcĪ² levels decrease to a greater extent in those with AD than in age-matched controls. Subjects carrying presenilin gene mutations show a significantly lower CSF p3-AlcĪ² level. A cell study with an inverse modulator of Ī³-secretase remarkably reduces the generation of p3-AlcĪ²37 while increasing the production of AĪ²42. Discussion Aging decreases the generation of p3-AlcĪ², and further significant decrease of p3-AlcĪ² caused by aberrant Ī³-secretase activity may accelerate pathogenesis in AD

    Decrease in p3-Alcb37 and p3-Alcb40, products of Alcadein b generated by g-secretase cleavages, in aged monkeys and patients with Alzheimerā€™s disease

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    Introduction Neuronal p3-AlcĪ² peptides are generated from the precursor protein Alcadein Ī² (AlcĪ²) through cleavage by Ī±- and Ī³-secretases of the amyloid Ī² (AĪ²) protein precursor (APP). To reveal whether p3-AlcĪ² is involved in Alzheimer\u27s disease (AD) contributes for the development of novel therapy and/or drug targets. Methods We developed new sandwich enzyme-linked immunosorbent assay (sELISA) systems to quantitate levels of p3-AlcĪ² in the cerebrospinal fluid (CSF). Results In monkeys, CSF p3-AlcĪ² decreases with age, and the aging is also accompanied by decreased brain expression of AlcĪ². In humans, CSF p3-AlcĪ² levels decrease to a greater extent in those with AD than in age-matched controls. Subjects carrying presenilin gene mutations show a significantly lower CSF p3-AlcĪ² level. A cell study with an inverse modulator of Ī³-secretase remarkably reduces the generation of p3-AlcĪ²37 while increasing the production of AĪ²42. Discussion Aging decreases the generation of p3-AlcĪ², and further significant decrease of p3-AlcĪ² caused by aberrant Ī³-secretase activity may accelerate pathogenesis in AD

    Extracellular Release of ILEI/FAM3C and Amyloid-Ī² Is Associated with the Activation of Distinct Synapse Subpopulations.

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    Background:Brain amyloid-Ī² (AĪ²) peptide is released into the interstitial fluid (ISF) in a neuronal activity-dependent manner, and AĪ² deposition in Alzheimer\u27s disease (AD) is linked to baseline neuronal activity. Although the intrinsic mechanism for AĪ² generation remains to be elucidated, interleukin-like epithelial-mesenchymal transition inducer (ILEI) is a candidate for an endogenous AĪ² suppressor.Objective:This study aimed to access the mechanism underlying ILEI secretion and its effect on AĪ² production in the brain.Methods:ILEI and AĪ² levels in the cerebral cortex were monitored using a newly developed ILEI-specific ELISA and in vivo microdialysis in mutant human AĪ² precursor protein-knockin mice. ILEI levels in autopsied brains and cerebrospinal fluid (CSF) were measured using ELISA.Results:Extracellular release of ILEI and AĪ² was dependent on neuronal activation and specifically on tetanus toxin-sensitive exocytosis of synaptic vesicles. However, simultaneous monitoring of extracellular ILEI and AĪ² revealed that a spontaneous fluctuation of ILEI levels appeared to inversely mirror that of AĪ² levels. Selective activation and inhibition of synaptic receptors differentially altered these levels. The evoked activation of AMPA-type receptors resulted in opposing changes to ILEI and AĪ² levels. Brain ILEI levels were selectively decreased in AD. CSF ILEI concentration correlated with that of AĪ² and were reduced in AD and mild cognitive impairment.Conclusion:ILEI and AĪ² are released from distinct subpopulations of synaptic terminals in an activity-dependent manner, and ILEI negatively regulates AĪ² production in specific synapse types. CSF ILEI might represent a surrogate marker for the accumulation of brain AĪ²
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