200 research outputs found

    Roles of silica and lignin in horsetail (Equisetum hyemale), with special reference to mechanical properties

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    This research deals with detailed analyses of silica and lignin distribution in horsetail with special reference to mechanical strength. Scanning electron images of a cross-section of an internode showed silica deposited densely only around the outer epidermis. Detailed histochemical analyses of lignin showed no lignin deposition in the silica-rich outer internodes of horsetail, while a characteristic lignin deposition was noticed in the vascular bundle in inner side of internodes. To analyze the structure of horsetail from a mechanical viewpoint, we calculated the response of a model structure of horsetail to a mechanical force applied perpendicularly to the long axis by a finite element method. We found that silica distributed in the outer epidermis may play the major structural role, with lignin's role being limited ensuring that the vascular bundle keep waterproof. These results were in contrast to more modern tall trees like gymnosperms, for which lignin provides mechanical strength. Lignin has the advantage of sticking to cellulose, hemicellulose, and other materials. Such properties make it possible for plants containing lignin to branch. Branching of tree stems aids in competing for light and other atmospheric resources. This type of branching was impossible for ancient horsetails, which relied on the physical properties of silica. From the evolutional view points, over millennia in trees with high lignin content, true branching, and many chlorophyll-containing leaves developed. (C) 2012 American Institute of Physics. [https://doi.org/10.1063/1.3688253]ArticleJOURNAL OF APPLIED PHYSICS. 111(4):044703 (2012)journal articl

    Nanocomposite of silk fibroin nanofiber and montmorillonite: Fabrication and morphology

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    The purpose of our research is creating a new nanocomposite material. Generally silk fibroin (SF) is regarded as a promising base material for biomedical uses. The incorporation of montmorillonite (MMT) into SF fibers would improve physical properties of the SF fibers. We investigated a new method of combining electospun SF with MMT. Specifically, electrospun silk nanofibers were treated with methanol and dipped in a MMT suspension. We could obtain a nanosheet composite of silk nanofibers and MMT. Their ultrastructures were successfully visualized by high resolution transmission electron microscopy. This compound was comprised of individual silk nanofibers surrounded by thin layers of MMT, each with a thickness of about 1.2 nm. This structure was confirmed by elemental analysis. We also performed IR, NMR and X-ray diffraction analyses in conjunction with morphological data. Conclusively we obtained a new composite of silk nanofiber and MMT, which has never been reported. Using this unique nanocomposite biological tests of its application for a scaffold for tissue engineering are under way.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 57:124-128 (2013)journal articl

    Structures and physiological functions of silica bodies in the epidermis of rice plants

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    We characterized silica structures in the epidermis of rice plant leaves and investigated their physiological functions from optical and mechanical viewpoints. By treating the distribution of silica bodies as a triangular lattice in the xy plane, and performing a theoretical optical analysis on this lattice, we discovered that a reduction in the photonic density of states may inhibit leaves of rice plant from being heated markedly higher than 20 degrees C. Ladderlike structures in the epidermis were mechanically investigated. These structures are conjectured to inhibit flat leaves from undergoing twisting torsions, which may assist the leaf to absorb sunlight more effectively for photosynthesis. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3232204]ArticleAPPLIED PHYSICS LETTERS. 95(12):123703 (2009)journal articl

    Added Diagnostic Value of Cerebrospinal Fluid Carcinoembryonic Antigen in a Patient with Leptomeningeal Carcinomatosis as the Initial Manifestation of Gastric Cancer

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    A 77-year-old woman with no history of malignancy presented with anorexia and bilateral lower extremity weakness. Her consciousness level worsened daily, so we performed a lumbar puncture. Cerebrospinal fluid (CSF) analysis indicated meningitis, but three rounds of CSF cytology showed no malignant cells. The patient’s carcinoembryonic antigen (CEA) level was highly elevated in CSF, but normal in serum. Through gadolinium-enhanced brain/spinal magnetic resonance imaging and gastrointestinal endoscopy, she was diagnosed with leptomeningeal carcinomatosis (LC) from gastric cancer. CEA level in CSF facilitated the diagnosis of LC from gastric cancer because there were no malignant cells on CSF cytology

    Device Failure in Bicuspid Aortic Stenosis Following Transcatheter Aortic Valve Implantation

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    Recent studies showed the favorable outcomes of transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve (BAV) stenosis. However, data on the rela-tion between BAV morphology and optimal transcatheter heart valve (THV) selection are limited. This study sought to evaluate the determinants of device performance in patients with BAV who underwent TAVI. Consecutive patients with BAV who under-went TAVI with the SAPIEN 3 from multicenters were evaluated. Outcomes were the incidence and predictors of device failure. Device failure was defined as peak aortic velocity > 3.0 m/s, mean pressure gradient > 20 mm Hg, moderate or severe paravalvular leakage and/or procedure mortality. A total of 187 patients with BAV were identified, aged 77 years, and 38.0% were women. A total of 37 patients (19.8%) were treated with 23-mm valve, 58 (31.0%) with 26-mm valve, and 92 (49.2%) with 29-mm valve. Predis -charge echocardiogram demonstrated 37 patients (19.8%) with device failure. BAV with excessive leaflet calcification plus calcified raphe (EC-BAV) (OR 16.7, 95% CI 1.99 to 39.6) and smaller THV (OR 4.41, 95% CI 1.43 to 13.6) were independently associated with increased risk of device failure. In addition, 4.0%, 5.1%, and 11.1% of device fail-ures were observed in patients without EC-BAV who underwent TAVI with 23-, 26-and 29-mm THV (p = 0.47), respectively, and 91.7%, 31.6% and 23.2% in those with EC-BAV, respectively (p < 0.001). In conclusion, EC-BAV morphology was the major deter-minant of a device failure after TAVI. Moreover, TAVI in patients with EC-BAV requir-ing small SAPIEN 3 could be challenging. Further data on device and treatment selection in patients with BAV are still warranted. (C) 2022 The Author(s). Published by Elsevier Inc.Peer reviewe

    Physicochemical characteristics of rapidly dried onion powder and its anti-atherogenic effect on rats fed high-fat diet

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    Rapidly dried onion (Milan cepa L. cv. Momiji No. 3) powder (OP) prepared from the outer layers (from second to fourth scale leaves from the surface) of onion bulbs was analysed for its quercetin and polyuronide contents, the effects of enzymatic treatment and the anti-atherogenic effect on rats fed a high-fat diet. Quercetin 4'-glucoside (50%), free quercetin (30%) and quercetin 3,4'-diglucoside (20%) were identified as quercetin derivatives, and boiling-water extraction was effective in extracting these compounds. OP contained 12.9% of polyuronides, the basic skeleton of pectin. Enzymatic degradation (cellulase and pectinase, 50 degrees C for 12 h, pH 6.0) of OP was effective in obtaining a slurry of smaller particle sizes. The free quercetin increased and the glucosides decreased with enzyme treatment. In Wistar rats fed an OP-added high-fat diet, the total cholesterol, HDL-cholesterol and triglyceride concentrations were not significantly different from the rats fed a high-fat diet without OP. However, the atherogenic index (AI) of Wistar rats fed an OP-added high-fat diet was lower (AI = 3.3) than rats fed the diet without OP (AI = 4.1). The incremental elastic modulus (IEM) of the aorta from rats fed the OP-added diet was also significantly lower than that of the rats fed the diet without OP. The AI and IEM values of the rats fed the OP-added diet were quite similar to the values of rats fed the diet without OP but were allowed spontaneous exercise. These results suggest that OP intake is effective for decreasing the risk of arteriosclerosis.ArticleFOOD CHEMISTRY. 129(3):810-815 (2011)journal articl

    Impact of Mild Paravalvular Regurgitation on Long- Term Clinical Outcomes After Transcatheter Aortic Valve Implantation

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    The impact of mild paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI) remains controversial. We evaluated the impact of mild PVR after TAVI on long-term clinical outcomes. We included patients who underwent TAVI for severe symptomatic aortic stenosis between December 2008 and June 2019 at 2 interna-tional centers and compared all-cause death between the group with mild PVR (group 1) and the group with none or trace PVR (group 2). PVR was categorized using a 3-class grading scheme, and patients with PVR >= moderate and those who were lost to follow-up were excluded. This retrospective analysis included 1,404 patients (mean age 81.7 +/- 6.5 years, 58.0% women). Three hundred fifty eight patients (25.5%) were classified into group 1 and 1,046 patients (74.5%) into group 2. At baseline, group 1 was older and had a lower body mass index, worse co-morbidities, and more severe aortic stenosis. To account for these differences, propensity score matching was performed, resulting in 332 matched pairs. Within these matched groups, during a mean follow-up of 3.2 years, group 1 had a significantly lower survival rate at 5 years (group 1: 62.0% vs group 2: 68.0%, log-rank p = 0.029, hazard ratio: 1.41 [95% confidence interval: 1.04 to 1.91]). In the matched cohort, patients with mild PVR had a significant 1.4-fold increased risk of mortality at 5 years after TAVI compared with those with none or trace PVR. Further studies with more patients are needed to evaluate the impact of longer-term outcomes.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) (Am J Cardiol 2023;191:14-22)Peer reviewe

    Retrospective clinical study on the notable efficacy and related factors of infliximab therapy in a rheumatoid arthritis management group in Japan: one-year clinical outcomes (RECONFIRM-2)

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    Biologics targeting TNF have brought about a paradigm shift in the treatment of rheumatoid arthritis (RA) and infliximab, anti-TNF-α chimeric monoclonal antibody, was marketed in 2003 in Japan. We previously reported on the RECONFIRM study, a retrospective clinical study on the efficacy of infliximab therapy in a RA management group in Japan, where we evaluated the clinical response after 22 weeks of the therapy in 258 patients. The study reported here was aimed at reconfirming the clinical efficacy of the infliximab therapy and demographic factors related to the efficacy over a 54-week study period in 410 RA patients in the same study group. Infliximab was infused according to the domestically approved method, and the clinical response was evaluated following 54 weeks of infliximab therapy using the European League Against Rheumatism (EULAR) response criteria. Disease activity was assessed by DAS28-CRP (Disease Activity Score including a 28-joint count/C-reactive protein). Infliximab was discontinued in 24.4% of the 410 patients at 54 weeks and 9.3% and 8.1% discontinued the therapy due to adverse events and inefficiency, respectively. Average DAS28-CRP decreased from 5.5 at week 0 to 3.1 at week 54 after the therapy. Patients in remission and those showing low-, moderate-, and high-disease activity changed from 0.0, 1.0, 9.0 and 90.0%, respectively, at the start of the study to 27.6, 11.7, 34.4 and 26.3%, respectively, at week 54. Younger age, RF-negativity and low scores of DAS28-CRP showed significant correlations with remission at week 54. EULAR response criteria—good, moderate, and no response to infliximab—were 37.0, 41.7 and 21.2%, respectively. In conclusion, we reconfirmed the clinical efficacy of infliximab and demographic factors related to the efficacy over a 54-week study period in 410 Japanese patients with RA using DAS28-CRP and EULAR response criteria
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