181 research outputs found

    ATS-6 spacecraft: In-flight antenna pattern measurement

    Get PDF
    Antenna patterns, principally associated with the 9.1 meter parabolic antenna of the ATS-6 spacecraft, were measured while in orbit at quasi-stationary synchronous altitude. Controlling the spacecraft attitude permitted a scanning of the spacecraft antenna pattern over the Rosman ground station, thus achieving the measurement of the antenna pattern contour. Patterns were determined in terms of relative gain referenced in position to the spacecraft body coordinates by means of signal power measurements made using a linear detector. These data were subsequently correlated with the attitude data to define the antenna patterns. Antenna patterns measured are presented and compared with available preflight patterns

    Characterization of Aerosol Deposited Cesium Lead Tribromide Perovskite Films on Interdigited ITO Electrodes

    Get PDF
    Aerosol deposition (AD) is a promising additive manufacturing method to fabricate low-cost, scalable films at room temperature, but has not been considered for semiconductor processing, so far. The successful preparation of cesium lead tribromide (CsPbBr) perovskite films on interdigitated indium tin oxide (ITO) electrodes by means of AD is reported here. The – µm thick layers are dense and have good adhesion to the substrate. The orthorhombic Pnma crystal structure of the precursor powder was retained during the deposition process with no signs of defect formation. The formation of electronic defects by photoluminescence spectroscopy is investigated and found slightly increased carrier recombination from defect sites for AD films compared to the powder. A nonuniform defect distribution across the layer, presumably induced by the impact of the semiconducting grains on the hard substrate surface, is revealed. The opto-electronic properties of AD processed semiconducting films is further tested by electrical measurements and confirmed good semiconducting properties and high responsivity for the films. These results demonstrate that AD processing of metal halide perovskites is possible for opto-electronic device manufacturing on D surfaces. It is believed that this work paves the way for the fabrication of previously unimaginable opto-electronic devices by additive manufacturing

    Skeletal Muscle-Specific Ablation of γcyto-Actin Does Not Exacerbate the mdx Phenotype

    Get PDF
    We previously documented a ten-fold increase in γcyto-actin expression in dystrophin-deficient skeletal muscle and hypothesized that increased γcyto-actin expression may participate in an adaptive cytoskeletal remodeling response. To explore whether increased γcyto-actin fortifies the cortical cytoskeleton in dystrophic skeletal muscle, we generated double knockout mice lacking both dystrophin and γcyto-actin specifically in skeletal muscle (ms-DKO). Surprisingly, dystrophin-deficient mdx and ms-DKO mice presented with comparable levels of myofiber necrosis, membrane instability, and deficits in muscle function. The lack of an exacerbated phenotype in ms-DKO mice suggests γcyto-actin and dystrophin function in a common pathway. Finally, because both mdx and ms-DKO skeletal muscle showed similar levels of utrophin expression and presented with identical dystrophies, we conclude utrophin can partially compensate for the loss of dystrophin independent of a γcyto-actin-utrophin interaction

    Impaction bone grafting of the acetabulum at hip revision using a mix of bone chips and a biphasic porous ceramic bone graft substitute: Good outcome in 43 patients followed for a mean of 2 years

    Get PDF
    Background and purpose One of the greatest problems of revision hip arthroplasty is dealing with lost bone stock. Good results have been obtained with impaction grafting of allograft bone. However, there have been problems of infection, reproducibility, antigenicity, stability, availability of bone, and cost. Thus, alternatives to allograft have been sought. BoneSave is a biphasic porous ceramic specifically designed for use in impaction grafting. BoneSave is 80% tricalcium phosphate and 20% hydroxyapatite. Previous in vitro and in vivo studies have yielded good results using mixtures of allograft and BoneSave, when compared with allograft alone. This study is the first reported human clinical trial of BoneSave in impaction grafting

    Zinc uptake promotes myoblast differentiation via Zip7 transporter and activation of Akt signalling transduction pathway

    Get PDF
    [EN] Myogenic regeneration occurs through a chain of events beginning with the output of satellite cells from quiescent state, formation of competent myoblasts and later fusion and differentiation into myofibres. Traditionally, growth factors are used to stimulate muscle regeneration but this involves serious off-target effects, including alterations in cell homeostasis and cancer. In this work, we have studied the use of zinc to trigger myogenic differentiation. We show that zinc promotes myoblast proliferation, differentiation and maturation of myofibres. We demonstrate that this process occurs through the PI3K/Akt pathway, via zinc stimulation of transporter Zip7. Depletion of zinc transporter Zip7 by RNA interference shows reduction of both PI3K/Akt signalling and a significant reduction of multinucleated myofibres and myotubes development. Moreover, we show that mature myofibres, obtained through stimulation with high concentrations of zinc, accumulate zinc and so we hypothesise their function as zinc reservoirs into the cell.P.R. and R.S. acknowledges support from the Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2015-69315-C3-1-R). P.R. acknowledges the Fondo Europeo de Desarrollo Regional (FEDER). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. R.S. acknowledges the support from the Spanish MECD through the PRX16/00208 grant. MSS acknowledges support from the European Research Council (ERC - HealInSynergy 306990) and the UK Engineering and Physical Sciences Research Council (EPSRC - EP/P001114/1)Mnatsakanyan, H.; Sabater I Serra, R.; Rico Tortosa, PM.; Salmerón Sánchez, M. (2018). Zinc uptake promotes myoblast differentiation via Zip7 transporter and activation of Akt signalling transduction pathway. Scientific Reports. 8:1-14. https://doi.org/10.1038/s41598-018-32067-0S1148Frontera, W. R. & Ochala, J. Skeletal muscle: a brief review of structure and function. Calcif. Tissue Int. 96, 183–195 (2015).Wolfe, R. R., Frontera, W. R. & Ochala, J. The underappreciated role of muscle in health and disease. Am. J. Clin. Nutr. 84, 475–82 (2006).Sciorati, C., Rigamonti, E., Manfredi, A. A. & Rovere-Querini, P. Cell death, clearance and immunity in the skeletal muscle. Cell Death Differ. 23, 927–937 (2016).Wang, Y. X. & Rudnicki, M. A. Satellite cells, the engines of muscle repair. Nat. Rev. Mol. Cell Biol. 13, 127–133 (2011).Yin, H., Price, F. & Rudnicki, M. A. Satellite cells and the muscle stem cell niche. Physiol. Rev. 93, 23–67 (2013).Dhawan, J. & Rando, T. A. Stem cells in postnatal myogenesis: Molecular mechanisms of satellite cell quiescence, activation and replenishment. Trends Cell Biol. 15, 666–673 (2005).Yun, K. & Wold, B. Skeletal muscle determination and differentiation: Story of a core regulatory network and its context. Curr. Opin. Cell Biol. 8, 877–889 (1996).Gharaibeh, B. et al. Biological approaches to improve skeletal muscle healing after injury and disease. Birth Defects Res. Part C Embryo Today Rev. 96, 82–94 (2012).Schiaffino, S. & Mammucari, C. Regulation of skeletal muscle growth by the IGF1-Akt/PKB pathway: insights from genetic models. Skelet. Muscle 1, 4 (2011).Sandri, M. Signaling in muscle atrophy and hypertrophy. Physiology (Bethesda). 23, 160–70 (2008).Karalaki, M., Fili, S., Philippou, A. & Koutsilieris, M. Muscle regeneration: cellular and molecular events. In Vivo 23, 779–96 (2009).Fujio, Y. et al. Cell cycle withdrawal promotes myogenic induction of Akt, a positive modulator of myocyte survival. Mol. Cell. Biol. 19, 5073–82 (1999).Wilson, E. M. & Rotwein, P. Control of MyoD function during initiation of muscle differentiation by an autocrine signaling pathway activated by insulin-like growth factor-II. J. Biol. Chem. 281, 29962–29971 (2006).Sun, L., Liu, L., Yang, X. & Wu, Z. Akt binds prohibitin 2 and relieves its repression of MyoD and muscle differentiation. J. Cell Sci. 117, 3021–3029 (2004).Milner, D. & Cameron, J. Muscle repair and regeneration: stem cells, scaffolds, and the contributions of skeletal muscle to amphibian limb regeneration. Curr. Top. Microbiol. Immunol. 367, 133–159 (2013).Liu, C. et al. PI3K/Akt signaling transduction pathway is involved in rat vascular smooth muscle cell proliferation induced by apelin-13. Acta Biochim Biophys Sin 42, 396–402 (2010).Eriksson, M., Taskinen, M. & Leppä, S. Mitogen Activated Protein Kinase-Dependent Activation of c-Jun and c-Fos is required for Neuronal differentiation but not for Growth and Stress Reposne in PC12 cells. J. Cell. Physiol. 207, 12–22 (2006).Arsic, N. et al. Vascular endothelial growth factor stimulates skeletal muscle regeneration in Vivo. Mol. Ther. 10, 844–854 (2004).Borselli, C. et al. Functional muscle regeneration with combined delivery of angiogenesis and myogenesis factors. Proc. Natl. Acad. Sci. USA 107, 3287–3292 (2010).Hanft, J. R. et al. Phase I trial on the safety of topical rhVEGF on chronic neuropathic diabetic foot ulcers. J. Wound Care 17(30–2), 34–7 (2008).Simón-Yarza, T. et al. Vascular endothelial growth factor-delivery systems for cardiac repair: An overview. Theranostics 2, 541–552 (2012).Briquez, P. S., Hubbell, J. A. & Martino, M. M. Extracellular Matrix-Inspired Growth Factor Delivery Systems for Skin Wound Healing. Adv. Wound Care 4, 479–489 (2015).Barthel, A., Ostrakhovitch, E. A., Walter, P. L., Kampkötter, A. & Klotz, L. O. Stimulation of phosphoinositide 3-kinase/Akt signaling by copper and zinc ions: Mechanisms and consequences. Arch. Biochem. Biophys. 463, 175–182 (2007).Ostrakhovitch, E. A., Lordnejad, M. R., Schliess, F., Sies, H. & Klotz, L.-O. Copper ions strongly activate the phosphoinositide-3-kinase/Akt pathway independent of the generation of reactive oxygen species. Arch. Biochem. Biophys. 397, 232–239 (2002).Kaur, K., Gupta, R., Saraf, S. A. & Saraf, S. K. Zinc: The metal of life. Compr. Rev. Food Sci. Food Saf. 13, 358–376 (2014).Coleman, J. E. Zinc proteins: enzymes, storage proteins, transcription factors, and replication proteins. Annu. Rev. Biochem. 61, 897–946 (1992).Fukada, T. & Kambe, T. Molecular and genetic features of zinc transporters in physiology and pathogenesis. Metallomics 3, 662–674 (2011).Murakami, M. & Hirano, T. Intracellular zinc homeostasis and zinc signaling. Cancer Sci. 99, 1515–1522 (2008).Hogstrand, C., Kille, P., Nicholson, R. I. & Taylor, K. M. Zinc transporters and cancer: a potential role for ZIP7 as a hub for tyrosine kinase activation. Trends Mol. Med. 15, 101–111 (2009).Kolenko, V., Teper, E., Kutikov, A. & Uzzo, R. Zinc and zinc transporters in prostate carcinogenesis. Nat. Rev. Urol. 10, 219–26 (2013).Myers, S. A., Nield, A., Chew, G. S. & Myers, M. A. The zinc transporter, Slc39a7 (Zip7) is implicated in glycaemic control in skeletal muscle cells. Plos One 8 (2013).Kambe, T., Tsuji, T., Hashimoto, A. & Itsumura, N. The Physiological, Biochemical, and Molecular Roles of Zinc Transporters in Zinc Homeostasis and Metabolism. Physiol. Rev. 95, 749–784 (2015).Jinno, N., Nagata, M. & Takahashi, T. Marginal zinc deficiency negatively affects recovery from muscle injury in mice. Biol. Trace Elem. Res. 158, 65–72 (2014).Taylor, K. M., Hiscox, S., Nicholson, R. I., Hogstrand, C. & Kille, P. Protein Kinase CK2 Triggers Cytosolic Zinc Signaling Pathways by Phosphorylation of Zinc Channel ZIP7. Sci. Signal. 5, ra11–ra11 (2012).Yamasaki, S. et al. Zinc is a novel intracellular second messenger. J. Cell Biol. 177, 637–45 (2007).Sumitani, S., Goya, K., Testa, J. R., Kouhara, H. & Kasayama, S. Akt1 and Akt2 differently regulate muscle creatine kinase and myogenin gene transcription in insulin-induced differentiation of C2C12 myoblasts. Endocrinology 143, 820–828 (2002).Ohashi, K. et al. Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade. Exp. Cell Res. 333, 228–237 (2015).Chesters, J. K. In Zinc in human biology 53, 109–118 (1989).Burattini, S. et al. C2C12 murine myoblasts as a model of skeletal muscle development: Morpho-functional characterization. Eur. J. Histochem. 48, 223–233 (2004).Mnatsakanyan, H. et al. Controlled Assembly of Fibronectin Nanofibrils Triggered by Random Copolymer Chemistry. ACS Appl. Mater. Interfaces 7, 18125–18135 (2015).Jeong, J. & Eide, D. J. The SLC39 family of zinc transporters. Molecular Aspects of Medicine 34, 612–619 (2013).Huang, L., Kirschke, C. P., Zhang, Y. & Yan, Y. Y. The ZIP7 gene (Slc39a7) encodes a zinc transporter involved in zinc homeostasis of the Golgi apparatus. J. Biol. Chem. 280, 15456–15463 (2005).Vallee, B. L. & Falchuk, K. H. The biochemical basis of zinc physiology. Physiological reviews 73 (1993).Ganju, N. & Eastman, A. Zinc inhibits Bax and Bak activation and cytochrome c release induced by chemical inducers of apoptosis but not by death-receptor-initiated pathways. Cell Death Differ. 10, 652–61 (2003).Chai, F., Truong-Tran, A. Q., Ho, L. H. & Zalewski, P. D. Regulation of caspase activation and apoptosis by cellular zinc fluxes and zinc deprivation: A review. Immunol. Cell Biol. 77, 272–278 (1999).Smith, P. J., Wiltshire, M., Furon, E., Beattie, J. H. & Errington, R. J. Impact of overexpression of metallothionein-1 on cell cycle progression and zinc toxicity. Am. J. Physiol. Cell Physiol. 295, C1399–C1408 (2008).Bozym, R. A. et al. Free zinc ions outside a narrow concentration range are toxic to a variety of cells in vitro. Exp. Biol. Med. (Maywood). 235, 741–50 (2010).Plum, L. M., Rink, L. & Hajo, H. The essential toxin: Impact of zinc on human health. Int. J. Environ. Res. Public Health 7, 1342–1365 (2010).Chen, C.-J. & Liao, S.-L. Zinc toxicity on neonatal cortical neurons: involvement of glutathione chelation. J. Neurochem. 85, 443–453 (2003).Chassot, A. A. et al. Confluence-induced cell cycle exit involves pre-mitotic CDK inhibition by p27Kip1 and cyclin D1 downregulation. Cell Cycle 7, 2038–2046 (2008).Spencer, S. L. et al. XThe proliferation-quiescence decision is controlled by a bifurcation in CDK2 activity at mitotic exit. Cell 155, 369–383 (2013).Walsh, K. & Perlman, H. Cell cycle exit upon myogenic differentiation. Curr. Opin. Genet. Dev. 7, 597–602 (1997).Puri, P. L. & Sartorelli, V. Regulation of muscle regulatory factors by DNA-binding, interacting proteins, and post-transcriptional modifications. Journal of Cellular Physiology 185, 155–173 (2000).Zammit, P. S., Partridge, T. A. & Yablonka-Reuveni, Z. The skeletal muscle satellite cell: the stem cell that came in from the cold. J Histochem Cytochem 54, 1177–1191 (2006).McCord, M. C. & Aizenman, E. The role of intracellular zinc release in aging, oxidative stress, and Alzheimer’s disease. Front. Aging Neurosci. 6, 1–16 (2014).Dirksen, R. T. Sarcoplasmic reticulum–mitochondrial through-space coupling in skeletal muscle. This paper is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic. Appl. Physiol. Nutr. Metab. 34, 389–395 (2009).Groth, C., Sasamura, T., Khanna, M. R., Whitley, M. & Fortini, M. E. Protein trafficking abnormalities in Drosophila tissues with impaired activity of the ZIP7 zinc transporter Catsup. Development 140, 3018–3027 (2013).Ellis, C. D. et al. Zinc and the Msc2 zinc transporter protein are required for endoplasmic reticulum function. J. Cell Biol. 166, 325–335 (2004).Koch, U., Lehal, R. & Radtke, F. Stem cells living with a Notch. Development 140, 689–704 (2013).Gardner, S., Anguiano, M. & Rotwein, P. Defining Akt actions in muscle differentiation. Am. J. Physiol. Physiol. 303, C1292–C1300 (2012).Knight, J. D. & Kothary, R. The myogenic kinome: protein kinases critical to mammalian skeletal myogenesis. Skelet. Muscle 1, 29 (2011).Roth, S. M. Genetic aspects of skeletal muscle strength and mass with relevance to sarcopenia. Bonekey Rep. 1, 1–7 (2012).Mebratu, Y. & Tesfaigzi, Y. How ERK1/2 Activation Controls Cell Proliferation and Cell Death Is Subcellular Localization the Answer? Cell Cycle 8, 1168–1175 (2009)

    β-Actin and γ-Actin Are Each Dispensable for Auditory Hair Cell Development But Required for Stereocilia Maintenance

    Get PDF
    Hair cell stereocilia structure depends on actin filaments composed of cytoplasmic β-actin and γ-actin isoforms. Mutations in either gene can lead to progressive hearing loss in humans. Since β-actin and γ-actin isoforms are 99% identical at the protein level, it is unclear whether each isoform has distinct cellular roles. Here, we compared the functions of β-actin and γ-actin in stereocilia formation and maintenance by generating mice conditionally knocked out for Actb or Actg1 in hair cells. We found that, although cytoplasmic actin is necessary, neither β-actin nor γ-actin is required for normal stereocilia development or auditory function in young animals. However, aging mice with β-actin– or γ-actin–deficient hair cells develop different patterns of progressive hearing loss and distinct pathogenic changes in stereocilia morphology, despite colocalization of the actin isoforms. These results demonstrate overlapping developmental roles but unique post-developmental functions for β-actin and γ-actin in maintaining hair cell stereocilia

    Expression and function of G-protein-coupled receptorsin the male reproductive tract

    Get PDF
    This review focuses on the expression and function of muscarinic acetylcholine receptors (mAChRs), α1-adrenoceptors and relaxin receptors in the male reproductive tract. The localization and differential expression of mAChR and α1-adrenoceptor subtypes in specific compartments of the efferent ductules, epididymis, vas deferens, seminal vesicle and prostate of various species indicate a role for these receptors in the modulation of luminal fluid composition and smooth muscle contraction, including effects on male fertility. Furthermore, the activation of mAChRs induces transactivation of the epidermal growth factor receptor (EGFR) and the Sertoli cell proliferation. The relaxin receptors are present in the testis, RXFP1 in elongated spermatids and Sertoli cells from rat, and RXFP2 in Leydig and germ cells from rat and human, suggesting a role for these receptors in the spermatogenic process. The localization of both receptors in the apical portion of epithelial cells and smooth muscle layers of the vas deferens suggests an involvement of these receptors in the contraction and regulation of secretion.Esta revisão enfatiza a expressão e a função dos receptores muscarínicos, adrenoceptores α1 e receptores para relaxina no sistema reprodutor masculino. A expressão dos receptores muscarínicos e adrenoceptores α1 em compartimentos específicos de dúctulos eferentes, epidídimo, ductos deferentes, vesícula seminal e próstata de várias espécies indica o envolvimento destes receptores na modulação da composição do fluido luminal e na contração do músculo liso, incluindo efeitos na fertilidade masculina. Além disso, a ativação dos receptores muscarínicos leva à transativação do receptor para o fator crescimento epidermal e proliferação das células de Sertoli. Os receptores para relaxina estão presentes no testículo, RXFP1 nas espermátides alongadas e células de Sertoli de rato e RXFP2 nas células de Leydig e germinativas de ratos e humano, sugerindo o envolvimento destes receptores no processo espermatogênico. A localização de ambos os receptores na porção apical das células epiteliais e no músculo liso dos ductos deferentes de rato sugere um papel na contração e na regulação da secreção.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FarmacologiaUNIFESP, EPM, Depto. de FarmacologiaSciEL
    corecore