9,218 research outputs found

    Effect of an Ethanol Extract of Scutellaria baicalensis on Relaxation in Corpus Cavernosum Smooth Muscle

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    Aims of study. The aim of the present study was to investigate whether an ethanol extract of Scutellaria baicalensis (ESB) relaxes penile corpus cavernosum muscle in organ bath experiments. Materials and methods. Changes in tension of cavernous smooth muscle strips were determined by penile strip chamber model and in penile perfusion model. Isolated endothelium-intact rabbit corpus cavernosum was precontracted with phenylephrine (PE) and then treated with ESB. Results. ESB relaxed penile smooth muscle in a dose-dependent manner, and this was inhibited by pre-treatment with NG-nitro-l-arginine methyl ester (l-NAME), a nitric oxide (NO) synthase inhibitor, and 1H-[1, 2, 4]-oxadiazolo-[4,3-α]-quinoxalin-1-one (ODQ), a soluble guanylyl cyclase (sGC) inhibitor. ESB-induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA), a nonselective K+ channel blocker, and charybdotoxin, a selective Ca2+-dependent K+ channel inhibitor. ESB increased the cGMP levels of rabbit corpus cavernosum in a concentration-dependent manner without changes in cAMP levels. In a perfusion model of penile tissue, ESB also relaxed penile corpus cavernosum smooth muscle in a dose-dependent manner. Conclusion. Taken together, these results suggest that ESB relaxed rabbit cavernous smooth muscle via the NO/cGMP system and Ca2+-sensitive K+ channels in the corpus cavernosum

    Quantum Spin Excitations through the metal-to-insulator crossover in YBa2Cu3O6+yY Ba_2 Cu_3 O_{6+y}

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    We use inelastic neutron scattering to study the temperature dependence of the spin excitations of a detwinned superconducting YBa2_2Cu3_3O6.45_{6.45} (Tc=48T_c=48 K). In contrast to earlier work on YBa2_2Cu3_3O6.5_{6.5} (Tc=58T_c=58 K), where the prominent features in the magnetic spectra consist of a sharp collective magnetic excitation termed ``resonance'' and a large (ω15\hbar\omega\approx 15 meV) superconducting spin gap, we find that the spin excitations in YBa2_2Cu3_3O6.45_{6.45} are gapless and have a much broader resonance. Our detailed mapping of magnetic scattering along the aa^\ast/bb^\ast-axis directions at different energies reveals that spin excitations are unisotropic and consistent with the ``hourglass''-like dispersion along the aa^\ast-axis direction near the resonance, but they are isotropic at lower energies. Since a fundamental change in the low-temperature normal state of YBa2_2Cu3_3O6+y_{6+y} when superconductivity is suppressed takes place at y0.5y\sim0.5 with a metal-to-insulator crossover (MIC), where the ground state transforms from a metallic to an insulating-like phase, our results suggest a clear connection between the large change in spin excitations and the MIC. The resonance therefore is a fundamental feature of metallic ground state superconductors and a consequence of high-TcT_c superconductivity.Comment: 9 pages, 7 figures, accepted by Phys. Rev.

    Traumatic Neuroma around the Celiac Trunk after Gastrectomy Mimicking a Nodal Metastasis: A Case Report

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    Traumatic neuroma is a well-known disorder that occurs after trauma or surgery involving the peripheral nerve and develops from a nonneoplastic proliferation of the proximal end of a severed, partially transected, or injured nerve. We present a case of traumatic neuroma around the celiac trunk after gastrectomy in a 56-year-old man, which was confirmed by pathology. CT demonstrated the presence of a lobulated, homogeneous, hypoattenuating mass around the celiac trunk, mimicking a nodal metastasis

    DNA Methylation and Expression Patterns of Key Tissue-specific Genes in Adult Stem Cells and Stomach Tissues

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    CpG-island margins and non-island-CpG sites round the transcription start sites of CpG-island-positive and -negative genes are methylated to various degrees in a tissue-specific manner. These methylation-variable CpG sites were analyzed to delineate a relationship between the methylation and transcription of the tissue-specific genes. The level of tissue-specific transcription was estimated by counting the number of the total transcripts in the SAGE (serial analysis of gene expression) database. The methylation status of 12 CpG-island margins and 21 non-island CpG sites near the key tissue-specific genes was examined in pluripotent stromal cells obtained from fat and bone marrow samples as well as in lineage-committed cells from marrow bulk, stomach, colon, breast, and thyroid samples. Of the 33 CpG sites examined, 10 non-island-CpG sites, but none of the CpG-island margins were undermethylated concurrent with tissue-specific expression of their nearby genes. The net methylation of the 33 CpG sites and the net amount of non-island-CpG gene transcripts were high in stomach tissues and low in stromal cells. The present findings suggest that the methylation of the non-island-CpG sites is inversely associated with the expression of the nearby genes, and the concert effect of transitional-CpG methylation is linearly associated with the stomach-specific genes lacking CpG-islands

    One-step deposition of nano-to-micron-scalable, high-quality digital image correlation patterns for high-strain in-situ multi-microscopy testing

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    Digital Image Correlation (DIC) is of vital importance in the field of experimental mechanics, yet, producing suitable DIC patterns for demanding in-situ mechanical tests remains challenging, especially for ultra-fine patterns, despite the large number of patterning techniques in the literature. Therefore, we propose a simple, flexible, one-step technique (only requiring a conventional deposition machine) to obtain scalable, high-quality, robust DIC patterns, suitable for a range of microscopic techniques, by deposition of a low melting temperature solder alloy in so-called 'island growth' mode, without elevating the substrate temperature. Proof of principle is shown by (near-)room-temperature deposition of InSn patterns, yielding highly dense, homogeneous DIC patterns over large areas with a feature size that can be tuned from as small as 10nm to 2um and with control over the feature shape and density by changing the deposition parameters. Pattern optimization, in terms of feature size, density, and contrast, is demonstrated for imaging with atomic force microscopy, scanning electron microscopy (SEM), optical microscopy and profilometry. Moreover, the performance of the InSn DIC patterns and their robustness to large deformations is validated in two challenging case studies of in-situ micro-mechanical testing: (i) self-adaptive isogeometric digital height correlation of optical surface height profiles of a coarse, bimodal InSn pattern providing microscopic 3D deformation fields (illustrated for delamination of aluminum interconnects on a polyimide substrate) and (ii) DIC on SEM images of a much finer InSn pattern allowing quantification of high strains near fracture locations (illustrated for rupture of a Fe foil). As such, the high controllability, performance and scalability of the DIC patterns offers a promising step towards more routine DIC-based in-situ micro-mechanical testing.Comment: Accepted for publication in Strai

    Control of crystallization in supramolecular soft materials engineering

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    As one class of the most important supramolecular functional materials, gels formed by low molecular weight gelators (LMWGs) have many important applications. The key important parameters affecting the in-use performance of a gel are determined by the hierarchical fiber network structures. Fiber networks consisting of weakly interacting multiple domains are commonly observed in gels formed by LMWGs. The rheological properties, particularly the elasticity, of a gel with such a fiber network are weak due to the weak interactions between the individual domains. As achieving desirable rheological properties of such a gel is practically relevant, in this work, we demonstrate the engineering of gels with such a type of fiber network by controlling crystallization of the gelator. Two example gels formed by a glutamic acid derivative in a non-ionic surfactant Tween 80 and in propylene glycol were engineered by controlling the thermodynamic driving force for crystallization. For a fixed gelator concentration, the thermodynamic driving force was manipulated by controlling the temperature for fiber crystallization. It was observed that there exists an optimal temperature at which a gel with maximal elasticity can be fabricated. This will hopefully provide guidelines for producing high performance soft materials by engineering their fiber network structures

    Effect of Dieckol, a Component of Ecklonia cava, on the Promotion of Hair Growth

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    This study was conducted to evaluate the effect of Ecklonia cava, a marine alga native to Jeju Island in Korea, on the promotion of hair growth. When vibrissa follicles were cultured in the presence of E. cava enzymatic extract (which contains more than 35% of dieckol) for 21 days, E. cava enzymatic extract increased hair-fiber length. In addition, after topical application of the 0.5% E. cava enzymatic extract onto the back of C57BL/6 mice, anagen progression of the hair-shaft was induced. The treatment with E. cava enzymatic extract resulted in the proliferation of immortalized vibrissa dermal papilla cells (DPC). Especially, dieckol, among the isolated compounds from the E. cava enzymatic extract, showed activity that increased the proliferation of DPC. When NIH3T3 fibroblasts were treated with the E. cava enzymatic extract and the isolated compounds from the E. cava enzymatic extract, the E. cava enzymatic extract increased the proliferation of NIH3T3 fibroblasts, but the isolated compounds such as eckol, dieckol, phloroglucinol and triphlorethol-A did not affect the proliferation of NIH3T3 fibroblasts. On the other hand, the E. cava enzymatic extract and dieckol significantly inhibited 5α-reductase activity. These results suggest that dieckol from E. cava can stimulate hair growth by the proliferation of DPC and/or the inhibition of 5α-reductase activity

    Effect of Agrimonia pilosa Ledeb Extract on the Antinociception and Mechanisms in Mouse

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    In the present study, the antinociceptive profiles of Agrimonia pilosa Ledeb extract were examined in ICR mice. Agrimonia pilosa Ledeb extract administered orally (200 mg/kg) showed an antinociceptive effect as measured by the tail-flick and hot-plate tests. In addition, Agrimonia pilosa Ledeb extract attenuated the writhing numbers in the acetic acid-induced writhing test. Furthermore, the cumulative nociceptive response time for intrathecal (i.t.) injection of substance P (0.7 µg) was diminished by Agrimonia pilosa Ledeb extract. Intraperitoneal (i.p.) pretreatment with yohimbine (α2-adrenergic receptor antagonist) attenuated antinociceptive effect induced by Agrimonia pilosa Ledeb extract in the writhing test. However, naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) did not affect antinociception induced by Agrimonia pilosa Ledeb extract in the writhing test. Our results suggest that Agrimonia pilosa Ledeb extract shows an antinociceptive property in various pain models. Furthermore, this antinociceptive effect of Agrimonia pilosa Ledeb extract may be mediated by α2-adrenergic receptor, but not opioidergic and serotonergic receptors
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