1,425 research outputs found

    Signaling Required for Blood Vessel Maintenance: Molecular Basis and Pathological Manifestations

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    As our understanding of molecular mechanisms leading to vascular formation increases, vessel maintenance including stabilization of new vessels and prevention of vessel regression began to be considered as an active process that requires specific cellular signaling. While signaling pathways such as VEGF, FGF, and angiopoietin-Tie2 are important for endothelial cell survival and junction stabilization, PDGF and TGF-β signaling modify mural cell (vascular smooth muscle cells and pericytes) functions, thus they fortify vessel integrity. Breakdown of these signaling systems results in pathological hyperpermeability and/or genetic vascular abnormalities such as vascular malformations, ultimately progressing to hemorrhage and edema. Hence, blood vessel maintenance is fundamental to controlling vascular homeostasis and tissue functions. This paper discusses signaling pathways essential for vascular maintenance and clinical conditions caused by deterioration of vessel integrity

    Recent Advances in Cross Aldol Reactions

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    The aldol reaction plays an important role in organic synthesis and provides very useful synthetic tools for stereoselective and asymmetric carbon-carbon bond formations. Four types of aldol reactions developed in our laboratory are discussed

    Fabrication of CNT/Cu Composite Yarn via Single-Step Electrodeposition

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    Carbon nanotube (CNT)/Cu composite yarns were formed via a single-step electrodeposition process. A twisted CNT yarn composed of multiwalled CNTs (MWCNTs) was used. Copper was directly electrodeposited onto the CNT yarn under galvanostatic conditions using copper sulfate baths with and without additives. Four additives (polyethylene glycol (PEG), chloride anion (Cl-), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB)) that are well known as "via-filling additives" were used together. The surface and cross-sectional microstructures of the copper-deposited CNT yarns were analyzed. Copper was electrodeposited only onto the surface of the CNT yarn from the bath without additives, resulting in a copper-coated CNT yarn. By contrast, copper was deposited not only onto the surface but also into the interior of the CNT yarn from the bath with the additives. The amount of copper deposited into the CNT yarn tended to increase with increasing PEG and Cl-concentrations. The current density also affected the size and location of the deposited copper particles. When the electrodeposition conditions were optimized, copper was relatively homogeneously deposited into the interior of the CNT yarn, resulting in a CNT/Cu composite yarn. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.ArticleJOURNAL OF THE ELECTROCHEMICAL SOCIETY. 167(10):102509 (2020)journal articl

    Methylation profiles of genes utilizing newly developed CpG island methylation microarray on colorectal cancer patients

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    Aberrant methylation of DNA has been shown to play an important role in a variety of human cancers, developmental disorders and aging. Hence, aberrant methylation patterns in genes can be a molecular marker for such conditions. Therefore, a reliable but uncomplicated method to detect DNA methylation is preferred, not merely for research purposes but for daily clinical practice. To achieve these aims, we have established a precise system to identify DNA methylation patterns based on an oligonucleotide microarray technology. Our microarray method has an advantage over conventional methods and is unique because it allows the precise measurement of the methylation patterns within a target region. Our simple signal detection system depends on using an avidin–biotinylated peroxidase complex and does not require an expensive laser scanner or hazardous radioisotope. In this study, we applied our technique to detect promoter methylation status of O(6)-methylguanine-DNA methyltransferase (MGMT) gene. Our easy-handling technology provided reproducible and precise measurement of methylated CpGs in MGMT promoter and, thus, our method may bring about a potential evolution in the handling of a variety of high-throughput DNA methylation analyses for clinical purposes

    Closure of multiple ventricular septal defects by the felt sandwich technique: Further analysis of 36 patients

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    ObjectivesWe previously described a novel technique for closure of trabecular ventricular septal defects by sandwiching the septum with 2 polyester felt patches without requiring left ventriculotomy. We describe the midterm results of this technique and the postoperative cardiac function.MethodsThis is a retrospective study of 36 consecutive patients. The median age and body weight at the time of repair was 15 months (range: 2-115 months) and 7.8 kg (range: 3.9-51.9 kg), respectively.ResultsSixty-three trabecular ventricular septal defects in 36 patients were closed with the felt sandwich technique. In the early postoperative period, 1 patient died of pulmonary hypertensive crisis. There were 2 late deaths. One patient died of pneumonia 6 months after surgery, and another died suddenly of ventricular arrhythmias 2 years after surgery. Three patients required reoperation (closure of major residual ventricular septal defect, cardiac transplantation for dilated cardiomyopathy, and pacemaker implantation for complete atrioventricular block). Postoperative left ventricular fractional shortening in the group with a body surface area less than 0.4 m2 was significantly lower than that in the group with a body surface area of 0.4 m2 or greater (0.22 ± 0.09 vs 0.31 ± 0.06, P = .0027). Moreover, there was a strong correlation between postoperative left ventricular ejection fraction and total patch area/body surface area ratio (R = −0.74, P = .0004).ConclusionMultiple trabecular ventricular septal defects can be closed with the felt sandwich technique easily and safely. Although this technique can be used in small infants, the use of numerous felt patches disturbs the movement of ventricular septum, which may cause postoperative cardiac dysfunction

    Massive Intravascular Hemolysis in a Patient Infected by a Clostridium perfringens

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    Clostridium perfringens infection is a very rare cause of massive intravascular hemolysis, but it should always be kept in mind, since only early treatment can rescue patients from an otherwise rapidly fatal outcome. We report a case of a 78-year-old diabetic male who was admitted complaining of general fatigue, dark red urine, and vomiting. His blood revealed massive hemolysis. Computer tomography demonstrated huge liver abscess in the right lobe of the liver. About 1 h after admission, he suddenly fell into a critical condition. He died 3 h after admission in spite of intensive care and resuscitation. Clostridium perfringens was detected from the blood taken before death and from liver abscess by biopsy after death. We concluded that this patient died of acute massive intravascular hemolysis in septicemia caused by Clostridium perfringens infection

    Spatial Domain Resource Sharing for Overlapping Cells in Indoor Environment

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    As microcell wireless systems become more widespread, intercell interference among the access points will increase due to the limited frequency resource. In the overlapping cell scenario, radio resources should be shared by multiple cells. Although time and frequency resource sharing has been described in many papers, there is no detailed report on dynamic spatial resource sharing among multiple cells for microcell wireless systems. Thus, we present the effectiveness of spatial resource sharing among two access points. We introduce two scenarios based on the zero forcing method; one is the primary-secondary AP scenario and the other is the cooperative AP scenario. To evaluate the transmission performance of spatial resource sharing, channel matrices are measured in an indoor environment. The simulation results using the measured channel matrices show the potential of spatial resource sharing
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