228 research outputs found
CP-Violation in the Renormalizable Theory of Weak Interaction
In a framework of the renormalizable theory of weak interaction, problems of CP-violation are studied. It is concluded that no realistic models of CP-violation exist in the quartet scheme without introducing any other new fields. Some possible models of CP-violation are also discussed
Invited - Characteristics of oxide TFT using atomic-layer deposited InOx-based metal oxide channel
InOx-based metal oxide semiconductors (InOx-OSs) including In-Ga-Zn-O (IGZO) [1,2] have been investigated as active channel materials in oxide thin film transistors (TFTs) for flat-panel display applications. These InOx-OSs have recently attracted attention for n-channel field effect transistor (n-FET) in back-end of line [3-5] and ferroelectric FET with HfO2-based ferroelectric gate insulator [6] First, InOx-OS films were deposited vis sputtering method. Considering to the growth of ultra-thin films, atomic layer deposition (ALD) technique is of great interest in the angstrom-scale thickness controllability, atomically smooth surface and composition control of multicomponent films as well as excellent step coverage on three-dimensional structure. The superior transistor performance of TFTs with ALD-In2O3 and IGZO channels and n-FET with ALD-In2O3 channel have been demonstrated [3,4,7]. Here, In2O3 films have been deposited via ALD with a combination of various precursors and oxidant gases such as trimethyl indium-O2, O3, H2O, or H2O2, and ethylcycropentadienyl indium (InEtCp)-H2O/O3 [8-10].
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Two mechanistically distinct effects of dihydropyridine nifedipine on Ca(V)1.2 L-type Ca2+ channels revealed by Timothy syndrome mutation
Dihydropyridine Ca2+ channel antagonists (DHPs) block Ca(V)1.2 L-type Ca2+ channels (LTCCs) by stabilizing their voltage-dependent inactivation (VDI); however, it is still not clear how DHPs allosterically interact with the kinetically distinct (fast and slow) VDI. Thus, we analyzed the effect of a prototypical DHP, nifedipine on LTCCs with or without the Timothy syndrome mutation that resides in the I-II linker (LI-II) of Ca(V)1.2 subunits and impairs VDI. Whole-cell Ba2+ currents mediated by rabbit Ca(V)1.2 with or without the Timothy mutation (G436R) (analogous to the human G406R mutation) were analyzed in the presence and absence of nifedipine. In the absence of nifedipine, the mutation significantly impaired fast closed-and open-state VDI (CSI and OSI) at -40 and 0 mV, respectively, but did not affect channels' kinetics at -100 mV. Nifedipine equipotently blocked these channels at -80 mV. In wild-type LTCCs, nifedipine promoted fast CSI and OSI at -40 and 0 mV and promoted or stabilized slow CSI at -40 and -100 mV, respectively. In LTCCs with the mutation, nifedipine resumed the impaired fast CSI and OSI at -40 and 0 mV, respectively, and had the same effect on slow CSI as in wild-type LTCCs. Therefore, nifedipine has two mechanistically distinct effects on LTCCs: the promotion of fast CSI/OSI caused by LI-II at potentials positive to the sub-threshold potential and the promotion or stabilization of slow CSI caused by different mechanisms at potentials negative to the subthreshold potential.ArticleEUROPEAN JOURNAL OF PHARMACOLOGY. 685(1-3):15-23 (2012)journal articl
Structural characterization of N-lignoceroyl (C24:0) sphingomyelin bilayer membranes : A reevaluation
Sphingomyelin (SM) is a membrane lipid and plays important roles in signaling, protein trafficking, cell growth and death. We investigated the structure of hydrated highly asymmetric SM, N-Lignoceroyl (C24:0) SM, bilayers with X-ray diffraction (XRD), simultanous small angle X-ray scattering (SAXS) and wide angle XRD, and SAXS measurements. At temperatures between two endothermic transitions of hydrated C24:0 SM bilayers, the C24:0 SM formed a ripple phase with the ripple periodicity of ~12-14 nm. About 3 month incubation at 277 K induced the formation of a stable phase with a short lamellar spacing of 5.62 nm. Based upon the structures revealed by this study and the phase behavior, we discuss the intermolecular interactions between C24:0 SM molecules in the bilayer membrane
Spontaneous Cardiac Hypertrophy in a Crl:CD(SD) Rat
Cardiac hypertrophy was observed in a 9-week-old Crl:CD(SD) rat that died unexpectedly. The animal was allocated to the control group of a toxicity study, and no abnormalities in its general conditions, body weight or food intake were observed. Necropsy revealed an increase in heart weight. Gross examination indicated cardiac enlargement with thickening of the right and left ventricular walls. Histopathological examination revealed hypertrophy of the cardiomyocytes in the right and left ventricular walls and the interventricular septum. Electron microscopic examination indicated bizarre nuclei and accumulation of an increased number of various sizes of mitochondria in the perinuclear region of the hypertrophied myocytes. Hypertrophied myocytes connected by intensely folded intercalated disks were also observed. Based on these findings, the animal was diagnosed with cardiac hypertrophy. This is the first case report of cardiac hypertrophy in this strain
Evaluation of AAV-DJ vector for retinal gene therapy
Purpose The most common virus vector used in gene therapy research for ophthalmologic diseases is the adeno-associated virus (AAV) vector, which has been used successfully in a number of preclinical and clinical studies. It is important to evaluate novel AAV vectors in animal models for application of clinical gene therapy. The AAV-DJ (type 2/type 8/type 9 chimera) was engineered from shuffling eight different wild-type native viruses. In this study, we investigated the efficiency of gene transfer by AAV-DJ injections into the retina. Methods One microliter of AAV-2-CAGGS-EGFP or AAV-DJ-CAGGS-EGFP vector at a titer of 1.4 × 10e12 vg/ml was injected intravitreally or subretinally in each eye of C57BL/6 mice. We evaluated the transduction characteristics of AAV-2 and -DJ vectors using fluorescence microscopy and electroretinography. Results The results confirmed that AAV-DJ could deeply transfer gene to photoreceptor layer with intravitreal injection and has an efficient gene transfer to various cell types especially the Mueller cells in the retina. Retinal function was not affected by AAV-DJ infection or ectopic EGFP expression. Conclusions The AAV-DJ vector efficiently induces the reporter gene in both the inner and outer murine retina without functional toxicity. These data indicated that the AAV-DJ vector is a useful tool for the gene therapy research targeting retinal disorders
Canola and hydrogenated soybean oils accelerate ectopic bone formation induced by implantation of bone morphogenetic protein in mice
AbstractCanola oil (Can) and hydrogenated soybean oil (H2-Soy) are commonly used edible oils. However, in contrast to soybean oil (Soy), they shorten the survival of stroke-prone spontaneously hypertensive (SHRSP) rats. It has been proposed that the adverse effects of these oils on the kidney and testis are caused at least in part by dihydro-vitamin K (VK) 1 in H2-Soy and unidentified component(s) in Can. Increased intake of dihydro-VK1 is associated with decreased tissue VK2 levels and bone mineral density in rats and humans, respectively. The aim of the present study was to determine the effects of these oils on bone morphogenetic protein (BMP)-induced ectopic bone formation, which is promoted by VK2 deficiency, in relation to the role of VK in the γ-carboxylation of osteocalcin and matrix Gla protein. A crude extract of BMPs was implanted into a gap in the fascia of the femoral muscle in 5-week-old mice maintained on a Soy, Can, or H2-Soy diet. Newly formed bone volume, assessed by three-dimensional X-ray micro-computed tomography and three-dimensional reconstruction imaging for bone, was 4-fold greater in the Can and H2-Soy groups than in the Soy group. The plasma carboxylated osteocalcin (Gla-OC) and total OC (Gla-OC plus undercarboxylated osteocalcin [Glu-OC]) levels were significantly lower in the Can group than in the Soy group (p < 0.05). However, these levels did not significantly differ between the H2-Soy and Soy groups. The plasma Gla-OC/Glu-OC ratio in the Can and H2-Soy groups was significantly lower (in Can; p = 0.044) or was almost significantly lower (in H2-Soy; p = 0.053) than that in the Soy group. In conclusion, Can and H2-Soy accelerated BMP-induced bone formation in mice to a greater extent than Soy. Further research is required to evaluate whether the difference in accelerated ectopic bone formation is associated with altered levels of VK2 and VK-dependent protein(s) among the three dietary groups
pH-dependent Formation of Membranous Cytoplasmic Body-like Structure of Ganglioside GM1/Bis(Monoacylglycero)Phosphate Mixed Membranes
Membrane structures of the mixtures of ganglioside GM1 and endosome specific lipid, bis(monoacylglycero)phosphate (BMP, also known as lysobisphosphatidic acid, LBPA) were examined at various pH conditions by freeze-fracture electron microscopy and small-angle x-ray scattering (SAXS). At pH 8.5 – 6.5, a GM1/BMP (1/1 mol/mol) mixture formed small vesicular aggregates, whereas the mixture formed closely packed lamellar structures under acidic conditions (pH 5.5, 4.6) with the lamellar repeat distance of 8.06 nm. Since BMP alone exhibits a diffuse lamellar structure at a broad range of pH values and GM1 forms a micelle, the present results indicate that both GM1 and BMP are required to produce the closely stacked multilamellar vesicles. These vesicles resemble membranous cytoplasmic bodies (MCB) in cells derived from patients suffering from GM1 gangliosidosis. Similar to GM1 gangliosidosis, cholesterol was trapped in BMP vesicles in GM1- and in a low pH-dependent manner. Studies employing different gangliosides and a GM1 analog suggest the importance of sugar chains and a sialic acid of GM1 in the pH-dependent structural change of GM1/BMP membranes
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