656 research outputs found

    Efficient ultrashort-pulse generation of Yb:YAG laser overcoming the fluorescence spectrum limit by using nonlinear medium

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    One-hundred-ten-fs and 72-fs pulse-widths were obtained directly from a mode-locked Yb:YAG laser with SESAM and without SESAM, respectively. The laser-spectrum-center and the fluorescence-center were almost same. The oscillation-spectra were much broader than the fluorescence

    Endoscopy-guided vitreoretinal surgery following penetrating corneal injury: a case report

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    Motoko Kawashima1, Shinichi Kawashima2, Murat Dogru1,3, Makoto Inoue4, Jun Shimazaki1,51Department of Ophthalmology, Tokyo Dental College, Chiba, Japan; 2Department of Ophthalmology, International University of Health and Welfare, Tokyo, Japan; 3Department of Ocular Surface and Visual Optics, Keio University School of Medicine, Tokyo, Japan; 4Kyorin Eye Center, Tokyo, Japan; 5Department of Ophthalmology, Keio University School of Medicine, Tokyo, JapanIntroduction: Severe ocular trauma requires emergency surgery, and a fresh corneal graft may not always be available. We describe a case of perforating eye injury with corneal ­opacity, suspected endophthalmitis, and an intraocular foreign body. The patient was successfully treated with a two-step procedure comprising endoscopy-guided vitrectomy followed by corneal transplantation. This surgical technique offers a good option to vitrectomy with simultaneous keratoplasty in emergency cases where no graft is immediately available and there is the ­possibility of infection due to the presence of a foreign body.Case presentation: A 55-year-old Japanese woman was referred to our hospital with a ­perforating corneal and lens injury sustained with a muddy ferrous rod. Primary corneal sutures and lensectomy were performed immediately. Vitreoretinal surgery was required due to ­suspected endophthalmitis, vitreous hemorrhage, retinal detachment, dialysis and necrosis of the peripheral retina. Instead of conventional vitrectomy, endoscopy-guided vitreous surgery was performed with the Solid Fiber Catheter AS-611 (FiberTech, Tokyo, Japan) due to the presence of corneal opacity and the unavailability of a donor cornea. The retina was successfully attached with the aid of a silicon oil tamponade. Following removal of the silicon oil at 3 months after surgery, penetrating keratoplasty and intraocular lens implantation with ciliary sulcus suture fixation were performed. At 6 months after penetrating keratoplasty, the graft remained clear and visual acuity was 20/40.Conclusion: Primary endoscopic surgery for vitreoretinal complications in eyes with perforating injury performed prior to penetrating keratoplasty appears to be advantageous in terms of avoiding damage to the corneal endothelium.Keywords: vitreoretinal surgery, emergency, foreign bod

    Combining hot-compressed water and ball milling pretreatments to improve the efficiency of the enzymatic hydrolysis of eucalyptus

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    <p>Abstract</p> <p>Background</p> <p>Lignocellulosic biomass such as wood is an attractive material for fuel ethanol production. Pretreatment technologies that increase the digestibility of cellulose and hemicellulose in the lignocellulosic biomass have a major influence on the cost of the subsequent enzymatic hydrolysis and ethanol fermentation processes. Pretreatments without chemicals such as acids, bases or organic solvents are less effective for an enzymatic hydrolysis process than those with chemicals, but they have a less negative effect on the environment.</p> <p>Results</p> <p>The enzymatic digestibility of eucalyptus was examined following a combined pretreatment without chemicals comprising a ball milling (BM) and hot-compressed water (HCW) treatment. The BM treatment simultaneously improved the digestibility of both glucan and xylan, and was effective in lowering the enzyme loading compared with the HCW treatment. The combination of HCW and BM treatment reduced the BM time. The eucalyptus treated with HCW (160°C, 30 minutes) followed by BM (20 minutes) had an approximately 70% yield of total sugar with a cellulase loading of 4 FPU/g substrate. This yield was comparable to the yields from samples treated with HCW (200°C, 30 minutes) or BM (40 minutes) hydrolyzed with 40 FPU/g substrate.</p> <p>Conclusion</p> <p>The HCW treatment is useful in improving the milling efficiency. The combined HCW-BM treatment can save energy and enzyme loading.</p

    Enhancement of β-xylosidase productivity in cellulase producing fungus Acremonium cellulolyticus

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    Enzymatic hydrolysis is one of the most important processes in bioethanol production from lignocellulosic biomass. Acremonium cellulolyticus is a filamentous fungus with high cellulase production but productivity of hemicellulase, especially β-xylosidase, is lower than other filamentous fungi. We identified 2.4 Kb β-xylosidase gene in the A. cellulolyticus genome sequence information and it encoded 798 amino acids without introns. To enhance hemicellulase productivity in A. cellulolyticus, we transformed this fungus with the identified β-xylosidase gene driven by the cellobiohydrolase Ι (cbh1) promoter, using the protoplast-polyethyleneglycol (PEG) method, and obtained a transformant, YKX1. Hydrolysis rate of xylooligosaccharides was more than 50-fold higher using culture supernatant from YKX1 than that from the parental strain, Y-94. Total cellulase activity (measured by filter paper assay) in YKX1 was not affected by the cbh1 promoter used for expression of β-xylosidase, and induced by cellulose. Since YKX1 can produce larger amount of β-xylosidase without affecting cellulase productivity, it is considered to be beneficial for practical monosaccharide recoveries from lignocellulosic biomass

    Utilizing Moving Vehicles as Sensors for Bridge Condition Screening – A Laboratory Verification

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    Health condition monitoring of bridge structures is attracting considerable attention, conventionally relying on visual inspection, and measurement-based methods that involve sensors installed directly on bridges. In recent years, drive-by monitoring methods that treat moving vehicles as moving sensors have been proposed as alternatives; these methods aim to be lowcost, mobile, and target fast bridge condition screening. In this study, we address the current lack of sufficient experimental verification of such methods. Laboratory experiments were conducted using a test vehicle system equipped with accelerometers in order to verify the practical feasibility of three drive-by methods: (1) bridge-frequency extraction using the Fourier spectrum of a vehicle’s dynamic response, (2) damage detection using the change in a vehicle’s spectral distribution pattern, and (3) roadway surface profile identification

    Unveiling the role of differential growth in 3D morphogenesis: An inference method to analyze area expansion rate distribution in biological systems

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    The three-dimensional (3D) morphologies of many organs in organisms, such as the curved shapes of leaves and flowers, the branching structure of lungs, and the exoskeletal shape of insects, are formed through surface growth. Although differential growth, a mode of surface growth, has been qualitatively identified as 3D morphogenesis, a quantitative understanding of the mechanical contribution of differential growth is lacking. To address this, we developed a quantitative inference method to analyze the distribution of the area expansion rate, which governs the growth of surfaces into 3D morphology. To validate the accuracy of our method, we tested it on a basic 3D morphology that allowed for the theoretical derivation of the area expansion rate distribution, and then assessed the difference between the predicted outcome and the theoretical solution. We also applied this method to complex 3D shapes and evaluated its accuracy through numerical experiments. The findings of the study revealed a linear decrease in error on a log-log scale with an increase in the number of meshes in both evaluations. This affirmed the reliability of the predictions for meshes that are sufficiently refined. Moreover, we employed our methodology to analyze the developmental process of the Japanese rhinoceros beetle Trypoxylus dichotomus, which is characterized by differential growth regulating 3D morphogenesis. The results indicated a notably high rate of area expansion on the left and right edges of the horn primordium, which is consistent with the experimental evidence of a higher rate of cell division in these regions. Hence, these findings confirm the efficacy of the proposed method in analyzing biological systems

    Sample Efficiency Improvement on Neuroevolution via Estimation-Based Elimination Strategy (Extended Abstract)

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    ABSTRACT In this paper, we propose estimation-based elimination strategy, which improves sample efficiency of NeuroEvolution (NE) algorithms. The fitness of new individuals was estimated using fitness of individuals evaluated in the past generations. The estimation was achieved by taking average fitness of individuals with high correlation with the new individual. Estimation-based elimination strategy avoids evaluating individuals with low estimated fitness. We adapt estimationbased elimination strategy for state-of-the-art NE algorithms: CMA-NeuroES and CMA-TWEANN. From the experimental results of pole-balancing benchmark tasks, we show that the proposed strategy improves sample efficiency of the NE algorithms
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