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Bone loss prevention in ovariectomized rats using stable amorphous calcium carbonate

Health 2013年第7期5卷 18-29页

作者： Galit Shaltiel elad bar-david Oren E. Meiron Eitan Waltman Assaf Shechter Eliahu D. Aflalo david Stepensky Amir Berman Berdine R. Martin Connie M. Weaver Amir Sagi Amorphical Ltd. Beer-Sheva Israel Department of Biotechnology Engineering Faculty of Engineering Sciences Ben-Gurion University of the Negev Beer-Sheva Israel Department of Food and Nutrition Purdue University West Lafayette USA Department of Life Sciences Faculty of Natural Sciences Ben-Gurion University of the Negev Beer-Sheva Israel Department of Pharmacology Faculty of Health Sciences Ben-Gurion University of the Negev Beer-Sheva Israel

In assessing the relationship between calcium supplementation and maintaining bone mass or reducing the risk of fracture, the effectiveness of calcium supplementation has never been decisive. Freshwater crayfish rely on amorphous calcium carbonate (ACC), an instable polymorph of calcium carbonate, as the main mineral in the exoskeleton and in the temporary storage organ, the gastrolith. Inspired by the crayfish model, we have previously shown an increase in calcium bioavailability in rats administered with synthetic stable ACC vs. crystalline calcium carbonate (CCC). The current study compared the effects of amorphous calcium derived from either gastrolith or synthetic ACC with those of crystalline calcium, found in commercial CCC or calciumcitrate supplements, in a bone loss prevention model. Rats were subjected to either sham or ovariectomy (OVX) operation (n^20/ group) followed by administration of food pellets supplemented with 0.5% calcium from either source over 12 weeks. Micro-computed tomography (μCT) and histomorphometric analyses revealed bone loss prevention by both gastrolith and ACC treatments, manifested by an increase in morphometric bone parameters, compared to both CCC-?and calcium citrate-treated groups. Both gastrolith and ACC treatments resulted in bone formation in the tibia cancellous bone, indicated by dynamic histomorphometry parameters, compared to either the CCC or calcium citrate treatments. Levels of urine deoxypyridinoline (DPD), suggested an anti-resorptive effect of ACC, which was also the only treatment that led to a significant increase in vertebral mechanical strength, as supported by μCT analysis of topology and orientation parameters of the vertebral trabeculae. To our knowledge, such levels of bone loss prevention by calcium supplements have never been reported. These findings thus suggest the potential of both natural (crayfish gastrolith) and, to a greater extent, synthetic ACC sources for the prevention of metabolic bone disor

关键词： Amorphous Calcium Carbonate Bone Metabolism Calcium Carbonate Calcium Citrate Gastrolith Osteoporosis Ovariectomized Rats

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Second harmonic generation hotspot on a centrosymmetric smooth silver surface

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Light(Science & Applications) 2018年第1期7卷 540-547页

作者： Matan Galanty Omer Shavit Adam Weissman Hannah Aharon david Gachet elad Segal Adi Salomon Department of Chemistry BINA Nano Center for Advanced MaterialsBar-Ilan UniversityRamat-GanIsrael Attolight AG EPFL Innovation ParkBuilding D1015 LausanneSwitzerland

Second harmonic generation(SHG)is forbidden for materials with inversion symmetry,such as bulk *** can be broken by morphological or dielectric discontinuities,yet SHG from a smooth continuous metallic surface is *** non-linear microscopy,we experimentally demonstrate enhanced SHG within an area of smooth silver film surrounded by ***-assisted SHG is locally enhanced by more than one order of magnitude compared to a neighboring silver surface *** optical measurements and cathodoluminescence(CL)imaging substantiate these *** suggest that plasmonic modes launched from the edges of the nanocavities propagate onto the smooth silver film and annihilate,locally generating *** addition,we show that these hotspots can be dynamically controlled in intensity and location by altering the polarization of the incoming *** results show that switchable nonlinear hotspots can be generated on smooth metallic films,with important applications in photocatalysis,single-molecule spectroscopy and non-linear surface imaging.

关键词： field. silver harmonic

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Forward stimulated Brillouin scattering and optomechanical non-reciprocity in standard polarization maintaining fibres

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Light(Science & Applications) 2021年第7期10卷 1275-1288页

作者： Gil Bashan Hilel Hagai Diamandi Yosef London Kavita Sharma Keren Shemer elad Zehavi Avi Zadok Faculty of Engineering and Institute for Nano-Technology and Advanced Materials Bar-Ilan UniversityRamat-Gan 5290002Israel

Opto-mechanical interactions in guided wave media are drawing great interest in fundamental research and *** stimulated Brillouin scattering,in particular,is widely investigated in optical fibres and photonic integrated *** this work,we report a comprehensive study of forward stimulated Brillouin scattering over standard,panda-type polarization maintaining *** distinguish between intra-polarization scattering,in which two pump tones are co-polarized along one principal axis,and inter-polarization processes driven by orthogonally polarized pump *** processes are quantified in analysis,calculations and ***-modal scattering,in particular,introduces cross-polarization switching of probe waves that is *** takes place in multiple wavelength *** results provide a first demonstration of opto-mechanical non-reciprocity of forward scatter in standard *** inter-polarization process is applicable to distributed sensors of media outside the cladding and coating boundaries,where light cannot *** process may be scaled towards forward Brillouin lasers,optical isolators and circulators and narrowband microwave-photonic filters over longer sections of off-the-shelf polarization maintaining fibres.

关键词： polarization scattering pump

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Activating Silent Glycolysis Bypasses in Escherichia coli

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BioDesign Research 2022年第1期2022卷 295-311页

作者： Camillo Iacometti Katharina Marx Maria Hönick Viktoria Biletskaia Helena Schulz-Mirbach Beau Dronsella Ari Satanowski Valérie A.Delmas Anne Berger Ivan Dubois Madeleine Bouzon Volker Döring elad Noor Arren bar-Even Steffen N.Lindner Max Planck Institute of Molecular Plant Physiology Am Mühlenberg 114476 Potsdam-GolmGermany Génomique Métabolique GenoscopeInstitut François JacobCEACNRSUniv EvryUniversitéParis-Saclay91057 Evry-CourcouronneFrance Institute of Molecular Systems Biology ETH ZürichOtto-Stern-Weg 38093 ZürichSwitzerland Department of Plant and Environmental Sciences Weizmann Institute of ScienceRehovotIsrael Department of Biochemistry CharitéUniversitätsmedizinVirchowweg 610117 BerlinGermany

All living organisms share similar reactions within their central metabolism to provide precursors for all essential building blocksand reducing power. To identify whether alternative metabolic routes of glycolysis can operate in E. coli, we complementarilyemployed in silico design, rational engineering, and adaptive laboratory evolution. First, we used a genome-scale model andidentified two potential pathways within the metabolic network of this organism replacing canonical Embden-Meyerhof-Parnas(EMP) glycolysis to convert phosphosugars into organic acids. One of these glycolytic routes proceeds via methylglyoxal andthe other via serine biosynthesis and degradation. Then, we implemented both pathways in E. coli strains harboring defectiveEMP glycolysis. Surprisingly, the pathway via methylglyoxal seemed to immediately operate in a triosephosphate isomerasedeletion strain cultivated on glycerol. By contrast, in a phosphoglycerate kinase deletion strain, the overexpression ofmethylglyoxal synthase was necessary to restore growth of the strain. Furthermore, we engineered the “serine shunt” whichconverts 3-phosphoglycerate via serine biosynthesis and degradation to pyruvate, bypassing an enolase deletion. Finally, toexplore which of these alternatives would emerge by natural selection, we performed an adaptive laboratory evolution studyusing an enolase deletion strain. Our experiments suggest that the evolved mutants use the serine shunt. Our study reveals theflexible repurposing of metabolic pathways to create new metabolite links and rewire central metabolism.

关键词： convert rational sugar

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