174 results match your criteria rectifying shape


A Developmental Science Perspective on Social Inequality.

Curr Dir Psychol Sci 2020 Dec 18;29(6):610-616. Epub 2020 Nov 18.

University of Maryland.

Many people believe in equality of opportunity, but overlook and minimize the structural factors that shape social inequalities in the United States and around the world, such as systematic exclusion (e.g., educational, occupational) based on group membership (e. Read More

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December 2020

The Role of Redundant Bases and Shrinkage Functions in Image Denoising.

IEEE Trans Image Process 2021 23;30:3778-3792. Epub 2021 Mar 23.

Wavelet denoising is a classical and effective approach for reducing noise in images and signals. Suggested in 1994, this approach is carried out by rectifying the coefficients of a noisy image, in the transform domain, using a set of shrinkage functions (SFs). A plethora of papers deals with the optimal shape of the SFs and the transform used. Read More

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Rectifying Supporting Regions With Mixed and Active Supervision for Rib Fracture Recognition.

IEEE Trans Med Imaging 2020 12 30;39(12):3843-3854. Epub 2020 Nov 30.

Automatic rib fracture recognition from chest X-ray images is clinically important yet challenging due to weak saliency of fractures. Weakly Supervised Learning (WSL) models recognize fractures by learning from large-scale image-level labels. In WSL, Class Activation Maps (CAMs) are considered to provide spatial interpretations on classification decisions. Read More

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December 2020

Demonstration of InP/InAsP/InP axial heterostructure nanowire array vertical LEDs.

Nanotechnology 2020 Sep 13;31(39):394003. Epub 2020 Jul 13.

Graduate School of Information Science and Technology and Research Center for Integrated Quantum Electronics, Hokkaido University, North 14 West 9, Sapporo 060-0814, Japan.

Semiconductor nanowires (NWs), which have nanoscale footprints, enable us to realize various quantum structures with excellent position and size controllability, utilizing a wide range of materials for heterostructures. In addition, enhancing light extraction and controlling spontaneous emission by modifying their size and shape are possible. Thus, NWs are promising materials for nanoscale light sources applicable from visible to telecommunication bands. Read More

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September 2020

GPCR-dependent biasing of GIRK channel signaling dynamics by RGS6 in mouse sinoatrial nodal cells.

Proc Natl Acad Sci U S A 2020 06 8;117(25):14522-14531. Epub 2020 Jun 8.

Department of Pharmacology, University of Minnesota, Minneapolis, MN 55455;

How G protein-coupled receptors (GPCRs) evoke specific biological outcomes while utilizing a limited array of G proteins and effectors is poorly understood, particularly in native cell systems. Here, we examined signaling evoked by muscarinic (MR) and adenosine (AR) receptor activation in the mouse sinoatrial node (SAN), the cardiac pacemaker. MR and AR activate a shared pool of cardiac G protein-gated inwardly rectifying K (GIRK) channels in SAN cells from adult mice, but AR-GIRK responses are smaller and slower than MR-GIRK responses. Read More

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Screening Technologies for Inward Rectifier Potassium Channels: Discovery of New Blockers and Activators.

Authors:
Kenneth B Walsh

SLAS Discov 2020 06 15;25(5):420-433. Epub 2020 Apr 15.

Department of Pharmacology, Physiology & Neuroscience, School of Medicine, University of South Carolina, Columbia, SC, USA.

K channels play a critical role in maintaining the normal electrical activity of excitable cells by setting the cell resting membrane potential and by determining the shape and duration of the action potential. In nonexcitable cells, K channels establish electrochemical gradients necessary for maintaining salt and volume homeostasis of body fluids. Inward rectifier K (Kir) channels typically conduct larger inward currents than outward currents, resulting in an inwardly rectifying current versus voltage relationship. Read More

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Systematic Analysis of Transcriptomic Profile of the Effects of Low Dose Atropine Treatment on Scleral Fibroblasts using Next-Generation Sequencing and Bioinformatics.

Int J Med Sci 2019 9;16(12):1652-1667. Epub 2019 Nov 9.

Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.

This study has two novel findings: it is not only the first to deduct potential genes involved in scleral growth repression upon atropine instillation from a prevention point of view, but also the first to demonstrate that only slight changes in scleral gene expression were found after atropine treatment as side effects and safety reasons of the eye drops are of concern. The sclera determines the final ocular shape and size, constituting of scleral fibroblasts as the principal cell type and the major regulator of extracellular matrix. The aim of our study was to identify differentially expressed genes and microRNA regulations in atropine-treated scleral fibroblasts that are potentially involved in preventing the onset of excessive ocular growth using next-generation sequencing and bioinformatics approaches. Read More

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Noise properties of rectifying and non-rectifying nanopores.

Nanotechnology 2019 Nov 26;31(10):10LT01. Epub 2019 Nov 26.

Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom.

Achieving a full understanding of the noise in resistive pulse sensing experiments is central to the development of this important single molecule technique. Here, we present a comprehensive study of the noise properties of conical glass nanopores as components in an ionic circuit by studying the power spectral density of the system in salt solutions at a range of concentrations. We begin by investigating the ionic current rectification of the pores, showing that it is only observed above a critical Dukhin number in agreement with theoretical predictions. Read More

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November 2019

Controlled size reduction and its underlying mechanism to form solid-state nanopores via electron beam induced carbon deposition.

Nanotechnology 2019 Nov 8;30(45):455303. Epub 2019 Aug 8.

Division of Solid-State Electronics, Department of Engineering Sciences, Uppsala University, SE-751 21 Uppsala, Sweden.

Solid-state nanopores have drawn considerable attention for their potential applications in DNA sequencing and nanoparticle analysis. However, fabrication of nanopores, especially those of diameter below 30 nm, requires sophisticated techniques. Here, a versatile method to controllably reduce the diameter of prefabricated large-size pores down to sub-30 nm without greatly increasing the effective pore depth from the original membrane thickness is shown. Read More

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November 2019

Altering integrin engagement regulates membrane localization of K2.1 channels.

J Cell Sci 2019 09 2;132(17). Epub 2019 Sep 2.

Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA

How ion channels localize and distribute on the cell membrane remains incompletely understood. We show that interventions that vary cell adhesion proteins and cell size also affect the membrane current density of inward-rectifier K channels (K2.1; encoded by ) and profoundly alter the action potential shape of excitable cells. Read More

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September 2019

Label-Free Whole Cell Biosensing for High-Throughput Discovery of Activators and Inhibitors Targeting G Protein-Activated Inwardly Rectifying Potassium Channels.

ACS Omega 2018 Nov 5;3(11):14814-14823. Epub 2018 Nov 5.

Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.

Dynamic mass redistribution (DMR) and cellular dielectric spectroscopy (CDS) are label-free biosensor technologies that capture real-time integrated cellular responses upon exposure to extra- and intracellular stimuli. They register signaling routes that are accompanied by cell shape changes and/or molecular movement of cells proximal to the biosensor to which they are attached. Here, we report the unexpected observation that robust DMR and CDS signatures are also elicited upon direct stimulation of G protein-activated inwardly rectifying potassium (GIRK) channels, which are involved in the regulation of excitability in the heart and brain. Read More

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November 2018

Graphene Oxide Upregulates the Homeostatic Functions of Primary Astrocytes and Modulates Astrocyte-to-Neuron Communication.

Nano Lett 2018 09 15;18(9):5827-5838. Epub 2018 Aug 15.

IRCCS Ospedale Policlinico , San Martino, Genova , Italy.

Graphene-based materials are the focus of intense research efforts to devise novel theranostic strategies for targeting the central nervous system. In this work, we have investigated the consequences of long-term exposure of primary rat astrocytes to pristine graphene (GR) and graphene oxide (GO) flakes. We demonstrate that GR/GO interfere with a variety of intracellular processes as a result of their internalization through the endolysosomal pathway. Read More

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September 2018

Ventral midbrain astrocytes display unique physiological features and sensitivity to dopamine D2 receptor signaling.

Neuropsychopharmacology 2019 01 13;44(2):344-355. Epub 2018 Jul 13.

Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.

Astrocytes are ubiquitous CNS cells that support tissue homeostasis through ion buffering, neurotransmitter recycling, and regulation of CNS vasculature. Yet, despite the essential functional roles they fill, very little is known about the physiology of astrocytes in the ventral midbrain, a region that houses dopamine-releasing neurons and is critical for reward learning and motivated behaviors. Here, using a combination of whole-transcriptome sequencing, histology, slice electrophysiology, and calcium imaging, we performed the first functional and molecular profiling of ventral midbrain astrocytes and observed numerous differences between these cells and their telencephalic counterparts, both in their gene expression profile and in their physiological properties. Read More

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January 2019

Endothelial GqPCR activity controls capillary electrical signaling and brain blood flow through PIP depletion.

Proc Natl Acad Sci U S A 2018 04 26;115(15):E3569-E3577. Epub 2018 Mar 26.

Department of Pharmacology, College of Medicine, University of Vermont, Burlington, VT 05405;

Brain capillaries play a critical role in sensing neural activity and translating it into dynamic changes in cerebral blood flow to serve the metabolic needs of the brain. The molecular cornerstone of this mechanism is the capillary endothelial cell inward rectifier K (Kir2.1) channel, which is activated by neuronal activity-dependent increases in external K concentration, producing a propagating hyperpolarizing electrical signal that dilates upstream arterioles. Read More

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Inwardly Rectifying Potassium (Kir) Channels Represent a Critical Ion Conductance Pathway in the Nervous Systems of Insects.

Sci Rep 2018 01 25;8(1):1617. Epub 2018 Jan 25.

Louisiana State University AgCenter, Department of Entomology, Baton Rouge, LA, 70803, USA.

A complete understanding of the physiological pathways critical for proper function of the insect nervous system is still lacking. The recent development of potent and selective small-molecule modulators of insect inward rectifier potassium (Kir) channels has enabled the interrogation of the physiological role and toxicological potential of Kir channels within various insect tissue systems. Therefore, we aimed to highlight the physiological and functional role of neural Kir channels the central nervous system, muscular system, and neuromuscular system through pharmacological and genetic manipulations. Read More

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January 2018

Generation of an induced pluripotent stem cell (iPSC) line from a patient with maturity-onset diabetes of the young type 13 (MODY13) with a the potassium inwardly-rectifying channel, subfamily J, member 11 (KCNJ11) mutation.

Stem Cell Res 2017 08 25;23:178-181. Epub 2017 Jul 25.

ESTeam Paris Sud, INGESTEM National IPSC Infrastructure, UPSud, Université Paris-Saclay, 94800 Villejuif, France; Division of Hematology, APHP-Paris Sud University hospitals, Le Kremlin Bicêtre 94275 and Villejuif, 94800, France; Division of Hematology, APHP-Paris Sud University Hospitals, Le Kremlin Bicêtre 94275, France; University Paris Sud, UPsud, Faculty of Medicine, Le Kremlin Bicêtre 94275, France.

Heterozygous activating mutation (p.Glu227Lys) in KCNJ11 leads to maturity-onset diabetes of the young (MODY) type 13, that is a subtype of dominant inherited young-onset non-autoimmune diabetes due to a primary defect in pancreatic beta cells. We generated induced pluripotent stem cells (iPSCs) from a patient with KCNJ11 mutation who developed MODY at 13years old. Read More

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ATP release during cell swelling activates a Ca-dependent Cl current by autocrine mechanism in mouse hippocampal microglia.

Sci Rep 2017 06 23;7(1):4184. Epub 2017 Jun 23.

Department of Physiology and Pharmacology, Sapienza University, Rome, Italy.

Microglia cells, resident immune cells of the brain, survey brain parenchyma by dynamically extending and retracting their processes. Cl channels, activated in the cellular response to stretch/swelling, take part in several functions deeply connected with microglia physiology, including cell shape changes, proliferation, differentiation and migration. However, the molecular identity and functional properties of these Cl channels are largely unknown. Read More

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Microparticles of healthy origins improve endothelial progenitor cell dysfunction via microRNA transfer in an atherosclerotic hamster model.

Acta Physiol (Oxf) 2017 Dec 8;221(4):230-249. Epub 2017 Jun 8.

Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of the Romanian Academy, Bucharest, Romania.

Aim: In this study, we aimed: (i) to obtain and functionally characterize the cultures of late endothelial progenitor cells (EPCs) from the animal blood; (ii) to investigate the potential beneficial effects of circulating microparticles (MPs) of healthy origins on EPC dysfunctionality in atherosclerosis as well as involved mechanisms.

Methods: Late EPCs were obtained and expanded in culture from peripheral blood isolated from two animal groups: hypertensive-hyperlipidaemic (HH) and control (C) hamsters. In parallel experiments, late EPC cultures from HH were incubated with MPs from C group. Read More

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December 2017

Calcium permeability of transient receptor potential canonical (TRPC) 4 channels measured by TRPC4-GCaMP6s.

Korean J Physiol Pharmacol 2017 Jan 21;21(1):133-140. Epub 2016 Dec 21.

Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.

Conflicting evidence has been obtained regarding whether transient receptor potential cation channels (TRPC) are store-operated channels (SOCs) or receptor-operated channels (ROCs). Moreover, the Ca/Na permeability ratio differs depending on whether the current-voltage (I-V) curve has a doubly rectifying shape or inward rectifying shape. To investigate the calcium permeability of TRPC4 channels, we attached GCaMP6s to TRPC4 and simultaneously measured the current and calcium signals. Read More

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January 2017

Inward-rectifying K (K2) leak conductance dampens the excitability of lamina I projection neurons in the neonatal rat.

Neuroscience 2016 Dec 14;339:502-510. Epub 2016 Oct 14.

Neuroscience Graduate Program, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, 231 Albert Sabin Way, Cincinnati, OH 45267, USA. Electronic address:

Spinal lamina I projection neurons serve as a major conduit by which noxious stimuli detected in the periphery are transmitted to nociceptive circuits in the brain, including the parabrachial nucleus (PB) and the periaqueductal gray (PAG). While neonatal spino-PB neurons are more than twice as likely to exhibit spontaneous activity compared to spino-PAG neurons, the underlying mechanisms remain unclear since nothing is known about the voltage-independent (i.e. Read More

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December 2016

Möbius bands, unstretchable material sheets and developable surfaces.

Proc Math Phys Eng Sci 2016 Aug;472(2192):20160459

Mathematical Soft Matter Unit , Okinawa Institute of Science and Technology Graduate University , Onna, Okinawa 904-0495, Japan.

A Möbius band can be formed by bending a sufficiently long rectangular unstretchable material sheet and joining the two short ends after twisting by 180. This process can be modelled by an isometric mapping from a rectangular region to a developable surface in three-dimensional Euclidean space. Attempts have been made to determine the equilibrium shape of a Möbius band by minimizing the bending energy in the class of mappings from the rectangular region to the collection of developable surfaces. Read More

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Contribution of the respiratory network to rhythm and motor output revealed by modulation of GIRK channels, somatostatin and neurokinin-1 receptors.

Sci Rep 2016 09 7;6:32707. Epub 2016 Sep 7.

Departments of Medicine and Physiology, University of Toronto, Toronto, Canada.

Breathing is generated by a respiratory network in the brainstem. At its core, a population of neurons expressing neurokinin-1 receptors (NK1R) and the peptide somatostatin (SST) form the preBötzinger Complex (preBötC), a site essential for the generation of breathing. PreBötC interneurons generate rhythm and follower neurons shape motor outputs by activating upper airway respiratory muscles. Read More

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September 2016

Electrophysiological Signature of Homomeric and Heteromeric Glycine Receptor Channels.

J Biol Chem 2016 08 5;291(34):18030-40. Epub 2016 Jul 5.

Cellular Neurosciences, Max-Delbrück-Centrum für Molekulare Medizin (MDC), Robert-Rössle-Strasse 10, 13092 Berlin, Germany

Glycine receptors are chloride-permeable, ligand-gated ion channels and contribute to the inhibition of neuronal firing in the central nervous system or to facilitation of neurotransmitter release if expressed at presynaptic sites. Recent structure-function studies have provided detailed insights into the mechanisms of channel gating, desensitization, and ion permeation. However, most of the work has focused only on comparing a few isoforms, and among studies, different cellular expression systems were used. Read More

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Pharmacological Conversion of a Cardiac Inward Rectifier into an Outward Rectifier Potassium Channel.

Mol Pharmacol 2016 Sep 31;90(3):334-40. Epub 2016 May 31.

Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México (E.G.M.-G., J.A.S.-C., R.A.N.-P.); Nora Eccles Harrison Cardiovascular Research and Training Institute, and Division of Pediatric Cardiology, University of Utah, Salt Lake City, Utah (M.T.-F.)

Potassium (K(+)) channels are crucial for determining the shape, duration, and frequency of action-potential firing in excitable cells. Broadly speaking, K(+) channels can be classified based on whether their macroscopic current outwardly or inwardly rectifies, whereby rectification refers to a change in conductance with voltage. Outwardly rectifying K(+) channels conduct greater current at depolarized membrane potentials, whereas inward rectifier channels conduct greater current at hyperpolarized membrane potentials. Read More

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September 2016

Spin rectification by orbital polarization in Bi-bilayer nanoribbons.

Phys Chem Chem Phys 2016 Mar;18(12):8637-42

Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.

We investigate the edge states of quantum spin-Hall phase Bi(111) bilayer nano-ribbons (BNRs) and their spin-rectifying effect using first-principles calculations and a non-equilibrium transport method. As low-dimensional materials, BNRs have tunable electronic properties, which are not only dependent on the edge shape, chemical passivation, or external electric fields but also governed by geometrical deformation. Depending on the passivation types, the interaction of the helical edge states in BNRs exhibits various patterns, enabling the valley engineering of the Dirac cones. Read More

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Dielectric relaxation properties of carboxylic acid-terminated n-alkyl monolayers tethered to Si(1 1 1): dynamics of dipoles and gauche defects.

Authors:
C Godet

J Phys Condens Matter 2016 Mar 12;28(9):094012. Epub 2016 Feb 12.

Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 35042 Rennes Cedex, France.

Molecular-level insights into the organization and dynamics of n-alkyl monolayers covalently bonded to Si(1 1 1) were gained from admittance measurements of dipolar relaxation in rectifying Hg|| HOOC-C10H(25-n) Si junctions performed as a function of applied voltage and temperature. A collective behavior of dipole dynamics is inferred from the non-Debye asymmetric relaxation peak shape and strong coupling of the dipole relaxation path with some bending vibrations of the n-alkyl OML (multi-excitation entropy model). A variety of relaxation mechanisms is observed in the frequency range (0. Read More

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Revealing the roles of GORK channels and NADPH oxidase in acclimation to hypoxia in Arabidopsis.

J Exp Bot 2017 06;68(12):3191-3204

School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia.

Regulation of root cell K+ is essential for acclimation to low oxygen stress. The potential roles of GORK (depolarization-activated guard cell outward-rectifying potassium) channels and RBOHD (respiratory burst oxidase homologue D) in plant adaptive responses to hypoxia were investigated in the context of tissue specificity (epidermis versus stele; elongation versus mature zone) in roots of Arabidopsis. The expression of GORK and RBOHD was down-regulated by 2- to 3-fold within 1 h and 24 h of hypoxia treatment in Arabidopsis wild-type (WT) roots. Read More

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Role of Kir2.1 in human monocyte-derived foam cell maturation.

J Cell Mol Med 2016 Mar 22;20(3):403-12. Epub 2015 Dec 22.

Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.

The role of K(+) channels in macrophage immunomodulation has been well-established. However, it remains unclear whether K(+) channels are involved in the lipid uptake of macrophages. The expression and function of the inward rectifier potassium channel (Kir2. Read More

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Involvement of Potassium and Cation Channels in Hippocampal Abnormalities of Embryonic Ts65Dn and Tc1 Trisomic Mice.

EBioMedicine 2015 Sep 31;2(9):1048-62. Epub 2015 Jul 31.

Department of Physics of Complex Systems, Weizmann Institute of Science, P.O. Box 26, Rehovot 76100 Israel.

Down syndrome (DS) mouse models exhibit cognitive deficits, and are used for studying the neuronal basis of DS pathology. To understand the differences in the physiology of DS model neurons, we used dissociated neuronal cultures from the hippocampi of Ts65Dn and Tc1 DS mice. Imaging of [Ca(2+)]i and whole cell patch clamp recordings were used to analyze network activity and single neuron properties, respectively. Read More

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September 2015

International Brainstorming Meeting on Etiologic and Risk Factors of Peri-implantitis, Montegrotto (Padua, Italy), August 2014.

Int J Oral Maxillofac Implants 2015 Sep-Oct;30(5):1093-104

The emerging literature has recently reported an alarming increase in peri-implantitis. This disease is typically described as the result of an imbalance between host response and bacterial load, supported by gram-negative anaerobic microflora. The current literature on the prevention and treatment of peri-implantitis does not allow for the extraction of applicable clinical information. Read More

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