159 research outputs found

    Spectrometric Determination of Various Metals by High-Frequency Plasma Torch

    Get PDF
    Several analytical conditions and detection limits of various metal elements were examined with regard to the determination of these elements by photoelectric spectrometry in the combination of high-frequency plasma torch apparatus and Ebert-type grating spectrometer (GE-340), using nitrogen as the carrier gas. Au the calibration curves for the elements showed good linearity and standard deviations of calcium, zinc, tin, lead, and bismuth were in the range of 1.0-3.2%. It was found that, among the various elements, aluminium, zinc, tungsten, and lead, which are difficult to be determined by flame-spectrometric analysis, can be determined with good sensitivity and high precision by the present method

    Direct-Reading, Time-Resolving Technique in Emission Spectroscopy and its Application to the Analysis of Iron, Steel and Iron Ores

    Get PDF
    An attempt of the time-resolution of emission spectra was carried out using a simple pulse generator by impressing a gate pulse on the dynodes of a photo-multiplier tube in the direct-reading spectrometer. Examinations were made on the variation of the intensity of spectral line with time in various atmospheres and it was confirmed that the after-glow is the longest in an argon atmosphere. The possibility of avoiding the effect of an interfering spectral line lying close to the analytical line was examined and this was proved to be possible with the analytical line of Si I 2881.58A and the interfering line of Cr II 2881.93A. The analytical line of calcium, Ca II 3933.67A, is interfered by Fe I 3933.61A and the effect of the spectral line of iron was avoided by the use of the time-resolving technique. This permitted the rapid determination of 0.001~0.1% of calcium in iron ores by the direct-reading spectrographic analysis

    Effect of Backing Metals in the X-Ray Fluorescence Spectral Analysis of Metal Films and its Application Absorption Edge Effect

    Get PDF
    The enhancement effect of the backing metal on the x-ray intensity of an element in a film has been studied. This effect is dependent on the wave length of the x-ray absorption edge of the element in the film. In the case of nickel film, the infinite thickness at which this effect is lost is about 20μ, and the infinite thickness is independent on the kind of backing metals. It has also been recognized that this enhancement effect is convenient for increasing the x-ray intensity of small amounts of an element. The application of this effect has been demonstrated for the determination of small amounts of nickel and cobalt, which were concentrated in an organic precipitate

    Peptidyl prolyl isomerase Pin1-inhibitory activity of d-glutamic and d-aspartic acid derivatives bearing a cyclic aliphatic amine moiety

    Get PDF
    AbstractPin1 is a peptidyl prolyl isomerase that specifically catalyzes cis–trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity

    Emission Spectrographic Determination of Oxygen in Steel by a D. C. Carbon Arc Method

    Get PDF
    The oxygen content in steel could be determined by a spectrographic method. A d.c. carbon arc discharge was used to extract oxygen as carbon monoxide from the sample. The intensity ratio of 0I 7771.9A/ArI 8006.2A was a function of the argon pressure in the excitation chamber, the current value and the oxygen content. The oxygen concentration in the range from 0.008 to 0.1 weight per cent could be determined from a variant coefficient of 7~12 per cent

    Induction of podoplanin by transforming growth factor-β in human fibrosarcoma

    Get PDF
    AbstractPodoplanin/aggrus is increased in tumors and its expression was associated with tumor malignancy. Podoplanin on cancer cells serves as a platelet-aggregating factor, which is associated with the metastatic potential. However, regulators of podoplanin remain to be determined. Transforming growth factor-β (TGF-β) regulates many physiological events, including tumorigenesis. Here, we found that TGF-β induced podoplanin in human fibrosarcoma HT1080 cells and enhanced the platelet-aggregating-ability of HT1080. TGF-β type I receptor inhibitor (SB431542) and short hairpin RNAs for Smad4 inhibited the podoplanin induction by TGF-β. These results suggest that TGF-β is a physiological regulator of podoplanin in tumor cells

    Regulation of c-MYC transcriptional activity by transforming growth factor-beta 1-stimulated clone 22

    Get PDF
    c‐MYC stimulates cell proliferation through the suppression of cyclin‐dependent kinase (CDK) inhibitors including P15 (CDKN2B) and P21 (CDKN1A). It also activates E‐box‐mediated transcription of various target genes including telomerase reverse transcriptase (TERT) that is involved in cellular immortality and tumorigenesis. Transforming growth factor‐beta 1 (TGF‐β1)‐stimulated clone 22 (TSC‐22/TSC22D1) encodes a highly conserved leucine zipper protein that is induced by various stimuli, including TGF‐β. TSC‐22 inhibits cell growth in mammalian cells and in Xenopus embryos. However, underlying mechanisms of growth inhibition by TSC‐22 remain unclear. Here, we show that TSC‐22 physically interacts with c‐MYC to inhibit the recruitment of c‐MYC on the P15 (CDKN2B) and P21 (CDKN1A) promoters, effectively inhibiting c‐MYC‐mediated suppression of P15 (CDKN2B) and also P21 (CDKN1A) promoter activities. In contrast, TSC‐22 enhances c‐MYC‐mediated activation of the TERT promoter. Additionally, the expression of TSC‐22 in embryonic stem cells inhibits cell growth without affecting its pluripotency‐related gene expression. These results indicate that TSC‐22 differentially regulates c‐MYC‐mediated transcriptional activity to regulate cell proliferation

    Different Patterns of Vascular Response Between Patients With or Without Diabetes Mellitus After Drug-Eluting Stent Implantation Optical Coherence Tomographic Analysis

    Get PDF
    ObjectivesWe performed this study to investigate with optical coherence tomography (OCT) the vascular response after sirolimus-eluting stent (SES) implantation between patients with and those without diabetes mellitus (DM).BackgroundThe difference in vascular response after SES implantation between patients with and those without DM has not been fully evaluated with OCT.MethodsOptical coherence tomography was performed to examine 74 nonrestenotic SES implanted in 63 patients (32 with DM and 31 without DM) at 9 months after SES implantation. For struts showing neointimal coverage, the neointimal thickness on the luminal side of each strut section was measured, and neointimal characteristics were classified into high, low, and layered signal pattern.ResultsBaseline patient characteristics and lesion and procedural characteristics data were similar between the 2 groups. In total, 11,422 struts were analyzed. High signal neointima was observed in 90.2 ± 13.9%, low signal neointima in 7.3 ± 10.0%, and layered neointima in 2.7 ± 5.8%/stents. There was higher incidence of low signal neointima (10.5 ± 10.3% vs. 4.5 ± 5.6%, p = 0.003), neointimal thickness was larger (median: 106.8 μm, interquartile range: 79.3 to 130.4 μm vs. median: 83.5 μm, interquartile range: 62.3 to 89.3 μm; p < 0.0001), and neointimal coverage of stent struts was higher (92.1 ± 6.2% vs. 87.2 ± 11.9%; p = 0.03) in DM patients.ConclusionsHigh signal neointimal pattern was predominantly observed, and low or layered signal pattern was observed in some cases. In DM patients, low signal neointima was observed with high frequency. Neointimal coverage and neointimal thickness was also higher in DM patients as compared with non-DM patients

    The Efficacy of a Bilateral Approach for Treating Lesions With Chronic Total Occlusions The CART (Controlled Antegrade and Retrograde subintimal Tracking) Registry

    Get PDF
    ObjectivesThe aim of this study was to evaluate the safety and feasibility of a new concept for chronic total occlusion (CTO) recanalization—using a bilateral approach that utilizes a Controlled Antegrade and Retrograde subintimal Tracking (CART) technique.BackgroundSuccessful percutaneous recanalization of coronary CTOs results in improved long-term outcomes. The recanalization of CTOs in native coronary arteries no doubt represents one of the most technically challenging of interventional procedures.MethodsA total of 224 consecutive patients (mean age 61 ± 9 years; 86.2% men) were enrolled in this prospective multicenter registry. This technique combines the simultaneous use of antegrade and retrograde approaches. A subintimal dissection is created in both antegrade and retrograde fashion, thereby limiting the extension of the subintimal dissection within the CTO portion.ResultsOf 224 CTO lesions (>3 months in duration) undergoing attempted recanalization using the CART technique, 145 cases (64.7%) had undergone previous CTO recanalization attempts. The success rates of crossing in a retrograde fashion with a wire and a balloon were 87.9% and 79.9%, respectively. The overall technical and procedural success rates achieved in this registry were 92.4% and 90.6%, respectively.ConclusionsA bilateral approach for CTO lesions using the CART technique is feasible, safe, and has a higher success rate than previous approaches. These results indicate that a bilateral technique can solve a major dilemma that commonly affects CTO procedures
    corecore