162 research outputs found

    Recent Advances in Welding Power Systems for Automated Welding

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    Sex chromosome evolution in snakes inferred from divergence patterns of two gametologous genes and chromosome distribution of sex chromosome-linked repetitive sequences

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    Molecular phylogenic trees of CTNNB1 gene. This figure shows neighbor-joining trees of CTNNB1 gene with the long alignment for 20 tetrapod species and the short alignment for 26 squamate species. (PDF 289 kb

    Mitogenomic evaluation of the historical biogeography of cichlids toward reliable dating of teleostean divergences

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    <p>Abstract</p> <p>Background</p> <p>Recent advances in DNA sequencing and computation offer the opportunity for reliable estimates of divergence times between organisms based on molecular data. Bayesian estimations of divergence times that do not assume the molecular clock use time constraints at multiple nodes, usually based on the fossil records, as major boundary conditions. However, the fossil records of bony fishes may not adequately provide effective time constraints at multiple nodes. We explored an alternative source of time constraints in teleostean phylogeny by evaluating a biogeographic hypothesis concerning freshwater fishes from the family Cichlidae (Perciformes: Labroidei).</p> <p>Results</p> <p>We added new mitogenomic sequence data from six cichlid species and conducted phylogenetic analyses using a large mitogenomic data set. We found a reciprocal monophyly of African and Neotropical cichlids and their sister group relationship to some Malagasy taxa (Ptychochrominae <it>sensu </it>Sparks and Smith). All of these taxa clustered with a Malagasy + Indo/Sri Lankan clade (Etroplinae <it>sensu </it>Sparks and Smith). The results of the phylogenetic analyses and divergence time estimations between continental cichlid clades were much more congruent with Gondwanaland origin and Cretaceous vicariant divergences than with Cenozoic transmarine dispersal between major continents.</p> <p>Conclusion</p> <p>We propose to add the biogeographic assumption of cichlid divergences by continental fragmentation as effective time constraints in dating teleostean divergence times. We conducted divergence time estimations among teleosts by incorporating these additional time constraints and achieved a considerable reduction in credibility intervals in the estimated divergence times.</p

    Nanotechnology and Regenerative Medicine A Novel Method Using Quantum Dots for Testing the Barrier Function of Cultured Epithelial Cell Sheets

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    Citation: Duncan TJ, Baba K, Oie Y, Nishida K. A novel method using quantum dots for testing the barrier function of cultured epithelial cell sheets. Invest Ophthalmol Vis Sci. 2015;56:221556: -222356: . DOI:10.1167 PURPOSE. The corneal epithelium provides a barrier to protect the deeper structures of the eye from any particles or pathogens. Cultured epithelial cell sheets are used in transplantation surgery for corneal repair or regeneration. The purpose of this study was to develop a novel method using fluorescent quantum dot nanoparticles for validating the quality and barrier function of cultured epithelial cell sheets. METHODS. Human function epithelial cell sheets, cultured from oral mucosal or corneal limbal cells, were incubated in either normal calcium-containing medium or medium containing no calcium with a calcium chelator. Also contained in the media were suspensions of two different sizes of quantum dots. Following incubation, analysis of quantum dot penetration was carried out using confocal microscopy. RESULTS. In contrast to the cell sheets incubated in calcium-containing medium, removal of extracellular calcium resulted in the disruption of tight junctions, compromising the cell sheet&apos;s barrier function. This caused a reduction in transepithelial electrical resistance and deeper, more ubiquitous penetration of the quantum dots into the paracellular space and interior of the cell sheet. CONCLUSIONS. This method provides easy to interpret qualitative and quantitative data on the functionality of a cell sheet&apos;s tight junctions, as well as nanoscale and microscale structural information on its surface and interior morphology, and any localized areas of damage or abnormality. This novel technique could be used as part of the validation system for cultured epithelial cell sheets for use in transplantation

    Visual discrimination of optical material properties : A large-scale study

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    Publisher Copyright: © 2022, Journal of Vision. All Rights Reserved.Complex visual processing involved in perceiving the object materials can be better elucidated by taking a variety of research approaches. Sharing stimulus and response data is an effective strategy to make the results of different studies directly comparable and can assist researchers with different backgrounds to jump into the field. Here, we constructed a database containing several sets of material images annotated with visual discrimination performance.We created the material images using physically based computer graphics techniques and conducted psychophysical experiments with them in both laboratory and crowdsourcing settings. The observer’s task was to discriminate materials on one of six dimensions (gloss contrast, gloss distinctness of image, translucent vs. opaque, metal vs. plastic, metal vs. glass, and glossy vs. painted). The illumination consistency and object geometry were also varied.We used a nonverbal procedure (an oddity task) applicable for diverse use cases, such as cross-cultural, cross-species, clinical, or developmental studies. Results showed that the material discrimination depended on the illuminations and geometries and that the ability to discriminate the spatial consistency of specular highlights in glossiness perception showed larger individual differences than in other tasks. In addition, analysis of visual features showed that the parameters of higher order color texture statistics can partially, but not completely, explain task performance. The results obtained through crowdsourcing were highly correlated with those obtained in the laboratory, suggesting that our database can be used even when the experimental conditions are not strictly controlled in the laboratory. Several projects using our dataset are underway.Peer reviewe

    A Difficult Differential Diagnosis of Acute Cholecystitis in a Patient With Steroid-induced Diabetes

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    An impairment of gallbladder motility due to autonomic neuropathy may cause cholestasis and result in gallbladder stone formation. Diabetes is one of risk factors for acute cholecystitis. Diabetes and steroid use are associated with the susceptibility to bacterial infections, we are apt to diagnose steroid-induced diabetic patients manifesting symptoms of cholecystitis as having acute bacterial infective cholecystitis. Here, we report a very rare steroid-induced diabetic patient complicated with gallbladder torsion-induced necrotizing cholecystitis due to a floating gallbladder

    Adipose-Derived Extract Suppresses IL-1 beta-Induced Inflammatory Signaling Pathways in Human Chondrocytes and Ameliorates the Cartilage Destruction of Experimental Osteoarthritis in Rats

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    We investigated the effects of adipose-derived extract (AE) on cultured chondrocytes and in vivo cartilage destruction. AE was prepared from human adipose tissues using a nonenzymatic approach. Cultured human chondrocytes were stimulated with interleukin-1 beta (IL-1 beta) with or without different concentrations of AE. The effects of co-treatment with AE on intracellular signaling pathways and their downstream gene and protein expressions were examined using real-time PCR, Western blotting, and immunofluorescence staining. Rat AE prepared from inguinal adipose tissues was intra-articularly delivered to the knee joints of rats with experimental osteoarthritis (OA), and the effect of AE on cartilage destruction was evaluated histologically. In vitro, co-treatment with IL-1 beta combined with AE reduced activation of the p38 and ERK mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of the p65 subunit of nuclear factor-kappa B (NF-kappa B), and subsequently downregulated the expressions of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, IL-6, and IL-8, whereas it markedly upregulated the expression of IL-1 receptor type 2 (IL-1R2) in chondrocytes. Intra-articular injection of homologous AE significantly ameliorated cartilage destruction six weeks postoperatively in the rat OA model. These results suggested that AE may exert a chondroprotective effect, at least in part, through modulation of the IL-1 beta-induced inflammatory signaling pathway by upregulation of IL-1R2 expression

    Expression of osteonectin in articular cartilage of osteoarthritic knees

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    The expression of osteonectin (ON) in osteoarthritic articular cartilage was investigated by enzyme immunohistochemistry and colloidal gold immunoelectron microscopy. A total of 96 specimens from 9 knees of 8 patients with osteoarthritis (OA) were examined. In OA cartilage, ON-positive cells varied in distribution and were not seen in all the specimens obtained from the same patient. However, in over half of the specimens (56 of 96), especially in the specimens of Mankin's grades from 4 to 9, which corresponds to relatively early stages of OA, ON was expressed in the cartilage above the calcified layer. On the other hand, ON was detected only in the calcified layer below the tidemark in normal articular cartilage. In addition, colloidal gold immunoelectron microscopy revealed ON in chondrocytes and matrix vesicles (MVs). These findings suggest that ON acts through MVs in the early stages of OA as a significant pathogenetic factor involved in intracartilage calcification, which is known to have a close relationship to the progression of OA.</p

    Reductive Metabolism of Ellagitannins in the Young Leaves of Castanopsis sieboldii

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    The leaves of Castanopsis sieboldii (Fagaceae) contain characteristic hexahydroxydiphenoyl (HHDP) esters of 28-O-glucosyl 2α,3β,23,24-tetrahydroxyolean- and urs-12-en-28-oic acids. In this study, uncharacterized substances were detected in the young leaves, which are not observed in the mature leaves. Preliminary HPLC analyses indicated that the substances had dehydro-HHDP (DHHDP) ester groups; however, the esters were unstable and decomposed during extraction. Therefore, the compounds were isolated as their stable phenazine derivatives by extracting the young leaves with acidic aqueous EtOH containing o-phenylenediamine. The structures of the phenazine derivatives indicated that the unstable metabolites of the young leaves were 3,24-DHHDP esters of the abovementioned triterpenes. Extraction of the young leaves with 80% acetonitrile containing reducing agents, ascorbic acid or dithiothreitol afforded the corresponding HHDP esters. Furthermore, heating of the young leaves in 80% acetonitrile also yielded the same HHDP esters as the reduction products. The results suggested that the HHDP esters are reductively produced from DHHDP esters in the young leaves. In addition, the structures of five previously reported triterpene HHDP esters were revised

    Cell jamming, stratification and p63 expression in cultivated human corneal epithelial cell sheets

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    Corneal limbal epithelial stem cell transplantation using cultivated human corneal epithelial cell sheets has been used successfully to treat limbal stem cell deficiencies. Here we report an investigation into the quality of cultivated human corneal epithelial cell sheets using time-lapse imaging of the cell culture process every 20 minutes over 14 days to ascertain the level of cell jamming, a phenomenon in which cells become smaller, more rounded and less actively expansive. In parallel, we also assessed the expression of p63, an important corneal epithelial stem cell marker. The occurrence of cell jamming was variable and transient, but was invariably associated with a thickening and stratification of the cell sheet. p63 was present in all expanding cell sheets in the first 9 days of culture, but it’s presence did not always correlate with stratification of the cell sheet. Nor did p63 expression necessarily persist in stratified cell sheets. An assessment of cell jamming, therefore, can shed significant light on the quality and regenerative potential of cultivated human corneal epithelial cell sheets
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