Titanium: A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Corrosion: The gradual destruction of a metal or alloy due to oxidation or action of a chemical agent. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Alloys: A mixture of metallic elements or compounds with other metallic or metalloid elements in varying proportions.Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Differential Thermal Analysis: Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated.Aerospace Medicine: That branch of medicine dealing with the studies and effects of flight through the atmosphere or in space upon the human body and with the prevention or cure of physiological or psychological malfunctions arising from these effects. (from NASA Thesaurus)Coated Materials, Biocompatible: Biocompatible materials usually used in dental and bone implants that enhance biologic fixation, thereby increasing the bond strength between the coated material and bone, and minimize possible biological effects that may result from the implant itself.MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Founder Effect: A phenomenon that is observed when a small subgroup of a larger POPULATION establishes itself as a separate and isolated entity. The subgroup's GENE POOL carries only a fraction of the genetic diversity of the parental population resulting in an increased frequency of certain diseases in the subgroup, especially those diseases known to be autosomal recessive.Osseointegration: The growth action of bone tissue as it assimilates surgically implanted devices or prostheses to be used as either replacement parts (e.g., hip) or as anchors (e.g., endosseous dental implants).Dental Casting Technique: The process of producing a form or impression made of metal or plaster using a mold.Directories as Topic: Lists of persons or organizations, systematically arranged, usually in alphabetic or classed order, giving address, affiliations, etc., for individuals, and giving address, officers, functions, and similar data for organizations. (ALA Glossary of Library and Information Science, 1983)Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Templates, Genetic: Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.DirectoryInternet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Metallurgy: The science, art, or technology dealing with processes involved in the separation of metals from their ores, the technique of making or compounding the alloys, the techniques of working or heat-treating metals, and the mining of metals. It includes industrial metallurgy as well as metallurgical techniques employed in the preparation and working of metals used in dentistry, with special reference to orthodontic and prosthodontic appliances. (From Jablonski, Dictionary of Dentistry, 1992, p494)Dental Alloys: A mixture of metallic elements or compounds with other metallic or metalloid elements in varying proportions for use in restorative or prosthetic dentistry.Social Marketing: Use of marketing principles also used to sell products to consumers to promote ideas, attitudes and behaviors. Design and use of programs seeking to increase the acceptance of a social idea or practice by target groups, not for the benefit of the marketer, but to benefit the target audience and the general society.Multimedia: Materials, frequently computer applications, that combine some or all of text, sound, graphics, animation, and video into integrated packages. (Thesaurus of ERIC Descriptors, 1994)Fraxinus: A plant genus of the family OLEACEAE. Members contain secoiridoid glucosides.Joint Commission on Accreditation of Healthcare Organizations: A private, voluntary, not-for-profit organization which establishes standards for the operation of health facilities and services, conducts surveys, and awards accreditation.Marketing: Activity involved in transfer of goods from producer to consumer or in the exchange of services.Lichens: Any of a group of plants formed by a symbiotic combination of a fungus with an algae or CYANOBACTERIA, and sometimes both. The fungal component makes up the bulk of the lichen and forms the basis for its name.Rubber: A high-molecular-weight polymeric elastomer derived from the milk juice (LATEX) of HEVEA brasiliensis and other trees and plants. It is a substance that can be stretched at room temperature to at least twice its original length and after releasing the stress, retract rapidly, and recover its original dimensions fully.Propantheline: A muscarinic antagonist used as an antispasmodic, in rhinitis, in urinary incontinence, and in the treatment of ulcers. At high doses it has nicotinic effects resulting in neuromuscular blocking.Steel: A tough, malleable, iron-based alloy containing up to, but no more than, two percent carbon and often other metals. It is used in medicine and dentistry in implants and instrumentation.Stainless Steel: Stainless steel. A steel containing Ni, Cr, or both. It does not tarnish on exposure and is used in corrosive environments. (Grant & Hack's Chemical Dictionary, 5th ed)Weather: The state of the ATMOSPHERE over minutes to months.Microcomputers: Small computers using LSI (large-scale integration) microprocessor chips as the CPU (central processing unit) and semiconductor memories for compact, inexpensive storage of program instructions and data. They are smaller and less expensive than minicomputers and are usually built into a dedicated system where they are optimized for a particular application. "Microprocessor" may refer to just the CPU or the entire microcomputer.Malus: A plant genus in the family ROSACEAE, order Rosales, subclass Rosidae. It is best known as a source of the edible fruit (apple) and is cultivated in temperate climates worldwide.Photography: Method of making images on a sensitized surface by exposure to light or other radiant energy.Educational Technology: Systematic identification, development, organization, or utilization of educational resources and the management of these processes. It is occasionally used also in a more limited sense to describe the use of equipment-oriented techniques or audiovisual aids in educational settings. (Thesaurus of ERIC Descriptors, December 1993, p132)Decision Making: The process of making a selective intellectual judgment when presented with several complex alternatives consisting of several variables, and usually defining a course of action or an idea.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Music: Sound that expresses emotion through rhythm, melody, and harmony.Music Therapy: The use of music as an adjunctive therapy in the treatment of neurological, mental, or behavioral disorders.Hexosaminidase A: A mammalian beta-hexosaminidase isoform that is a heteromeric protein comprized of both hexosaminidase alpha and hexosaminidase beta subunits. Deficiency of hexosaminidase A due to mutations in the gene encoding the hexosaminidase alpha subunit is a case of TAY-SACHS DISEASE. Deficiency of hexosaminidase A and HEXOSAMINIDASE B due to mutations in the gene encoding the hexosaminidase beta subunit is a case of SANDHOFF DISEASE.Tay-Sachs Disease: An autosomal recessive neurodegenerative disorder characterized by the onset in infancy of an exaggerated startle response, followed by paralysis, dementia, and blindness. It is caused by mutation in the alpha subunit of the HEXOSAMINIDASE A resulting in lipid-laden ganglion cells. It is also known as the B variant (with increased HEXOSAMINIDASE B but absence of hexosaminidase A) and is strongly associated with Ashkenazic Jewish ancestry.Heptanoic Acids: 7-carbon saturated monocarboxylic acids.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Vocabulary, Controlled: A specified list of terms with a fixed and unalterable meaning, and from which a selection is made when CATALOGING; ABSTRACTING AND INDEXING; or searching BOOKS; JOURNALS AS TOPIC; and other documents. The control is intended to avoid the scattering of related subjects under different headings (SUBJECT HEADINGS). The list may be altered or extended only by the publisher or issuing agency. (From Harrod's Librarians' Glossary, 7th ed, p163)High-Throughput Nucleotide Sequencing: Techniques of nucleotide sequence analysis that increase the range, complexity, sensitivity, and accuracy of results by greatly increasing the scale of operations and thus the number of nucleotides, and the number of copies of each nucleotide sequenced. The sequencing may be done by analysis of the synthesis or ligation products, hybridization to preexisting sequences, etc.Heart-Assist Devices: Small pumps, often implantable, designed for temporarily assisting the heart, usually the LEFT VENTRICLE, to pump blood. They consist of a pumping chamber and a power source, which may be partially or totally external to the body and activated by electromagnetic motors.Radiology Information Systems: Information systems, usually computer-assisted, designed to store, manipulate, and retrieve information for planning, organizing, directing, and controlling administrative activities associated with the provision and utilization of radiology services and facilities.Video Games: A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.Prosthesis Implantation: Surgical insertion of a prosthesis.ManikinsAgriculture: The science, art or practice of cultivating soil, producing crops, and raising livestock.

An animal exposure system using ultrasonic nebulizer that generates well controlled aerosols from liquids. (1/1876)

Various aerosol generators have been developed for animal inhalation experiments and the performance tests of measuring instruments and respirators. It has been, however, difficult to generate aerosols from an aqueous solution or suspension keeping the concentration and particle size distribution constant for a long time. Resolving such difficulties, the present study developed an animal exposure system that generates well-controlled and stable aerosols from liquids. The exposure system consists of an aerosol generator using ultrasonic nebulizer, a mixing chamber and an exposure chamber. The validity of this system was confirmed in the generation of NiCl2 and TiO2 aerosol from solution and suspension, respectively. The concentration levels of NiCl2 aerosol were kept at 3.2 mg/m3 and 0.89 mg/m3 for 5 hours with good coefficients of variation (CVs) of 2.5% and 1.7%, respectively. For TiO2 aerosol, the concentration levels of 1.59 mg/m3 and 0.90 mg/m3 were kept for 5 hours with small CVs of 1.3% and 2.0%, respectively. This exposure system could be sufficiently used for inhalation experiments with even high toxic aerosols such as NiCl2 because a momentary high concentration possibly affects results and an extremely stable concentration is required.  (+info)

Induction of macrophage C-C chemokine expression by titanium alloy and bone cement particles. (2/1876)

Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1alpha), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1alpha expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1alpha in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1alpha were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1alpha inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.  (+info)

Coating titanium implants with bioglass and with hydroxyapatite. A comparative study in sheep. (3/1876)

This study compares the osteointegration of titanium implants coated with bioglass (Biovetro GSB formula) and with hydroxyapatite (HAP). Twenty-four bioglass-coated and 24 HAP-coated cylinders were implanted in the femoral diaphyses of sheep, and examined after 2, 4, 6, 8, 12, and 16 weeks. The HAP coating gave a stronger and earlier fixation to the bone than did bioglass. Bioglass formed a tissue interface which showed a macrophage reaction with little new bone formation activity. In contrast, HPA, showed intense new bone formation, with highly mineralised osseous trabeculae in the neighbourhood of the interface.  (+info)

Role of the scavenger receptor MARCO in alveolar macrophage binding of unopsonized environmental particles. (4/1876)

Alveolar macrophages (AMs) avidly bind and ingest unopsonized environmental particles and bacteria through scavenger-type receptors (SRs). AMs from mice with a genetic deletion of the major macrophage SR (types AI and AII; SR-/-) showed no decrease in particle binding compared with SR+/+ mice, suggesting that other SRs are involved. To identify these receptors, we generated a monoclonal antibody (mAb), PAL-1, that inhibits hamster AM binding of unopsonized particles (TiO2, Fe2O3, and latex beads; 66 +/- 5, 77 +/- 2, and 85 +/- 2% inhibition, respectively, measured by flow cytometry). This antibody identifies a protein of approximately 70 kD on the AM surface (immunoprecipitation) that is expressed by AMs and other macrophages in situ. A cDNA clone encoding the mAb PAL-1-reactive protein isolated by means of COS cell expression was found to be 84 and 77% homologous to mouse and human scavenger receptor MARCO mRNA, respectively. Transfection of COS cells with MARCO cDNA conferred mAb-inhibitable TiO2 binding. Hamster MARCO also mediates AM binding of unopsonized bacteria (67 +/- 5 and 47 +/- 4% inhibition of Escherichia coli and Staphylococcus aureus binding by mAb PAL-1). A polyclonal antibody to human MARCO identified the expected approximately 70-kD band on Western blots of lysates of normal bronchoalveolar lavage (BAL) cells (>90% AMs) and showed strong immunolabeling of human AMs in BAL cytocentrifuge preparations and within lung tissue specimens. In normal mouse AMs, the anti-MARCO mAb ED31 also showed immunoreactivity and inhibited binding of unopsonized particles (e.g., TiO2 approximately 40%) and bacteria. The novel function of binding unopsonized environmental dusts and pathogens suggests an important role for MARCO in the lungs' response to inhaled particles.  (+info)

Titanium aneurysm clips: mechanical characteristics and clinical trial. (5/1876)

Titanium clip is well documented to reduce the artifact observed in computed tomography (CT) or magnetic resonance (MR) imaging and improve the quality of these images. There are, however, some demerits based on metallic characteristics including large spring portions, lack of long and fenestration clips, and difficulties to produce. We examined the mechanical characteristics of Sugita titanium aneurysm clips (product of 6 aluminium-4 vanadium-titanium) and investigate the safety in clinical use and the imaging quality compared with those of cobalt (Co) alloy clips. On mechanical test, Sugita titanium clips showed no significant difference in closing force compared with the conventional Co alloy clips. The closing force reduced about 10% after 100 times repeated opening in titanium clips in contrast with no remarkable changes in Co alloy clips. Sixty-four patients with ruptured or unruptured cerebral aneurysms (total number of 71 aneurysms) were treated with Sugita titanium clips through the microsurgical technique. None of the unfavorable outcome occurred in related to the titanium clips. Neither clip dislocation nor deformation was experienced in this series during the follow-up period. The clip artifacts seen in CT and MR image were markedly reduced, however, MR angiography had less quality to resolve anatomical structures due to an existence of vessel gap. These results indicate that in spite of some disadvantages, Sugita titanium clips allow safe and beneficial use routinely in aneurysm surgery insofar as the complete clipping is obtained.  (+info)

Intra-oral temperature variation over 24 hours. (6/1876)

This study aimed to investigate temperature variation at archwire sites adjacent to the maxillary right central incisor and first premolar, its correlation with ambient temperature, and the influence of inter-racial variation. Twenty young adult male subjects were randomly selected (13 Asian, seven Caucasian). Thermocouples were attached to the labial archwire component of custom-made orthodontic retainers at the two intra-oral sites. A third thermocouple measured ambient temperature. A data-logger recorded temperatures at 5-second intervals over a 24-hour period. Temperatures ranged from 5.6 to 58.5 degrees C at the incisor and from 7.9 to 54 degrees C at the premolar, with medians of 34.9 degrees C and 35.6 degrees C, respectively. Ambient temperature correlated poorly with the intra-oral temperatures. The Asian and Caucasian groups had significantly different temperature distributions. On average during the 24-hour period, temperatures at the incisor site were in the range of 33-37 degrees C for 79 per cent of the time, below it for 20 per cent, and above it for only 1 per cent of the time. Corresponding figures for the premolar site were 92, 6, and 2 per cent. At both archwire sites the most frequent temperatures were in the range of 35-36 degrees C. The data presented demonstrate that the temperature at sites on an archwire in situ varies considerably over a 24-hour period and that racial differences may exist. This information should be considered during the manufacture and use of temperature-sensitive orthodontic materials, in particular nickel-titanium archwires and springs.  (+info)

The effect of hydroxyapatite coating on the bonding of bone to titanium implants in the femora of ovariectomised rats. (7/1876)

We have studied the effect of hydroxyapatite (HA) coating in 15 ovariectomised and 15 normal rats which had had a sham procedure. Twenty-four weeks after operation, HA-coated implants were inserted into the intramedullary canal of the right femur and uncoated implants into the left femur. The prostheses were removed four weeks after implantation. Twelve specimens in each group had mechanical push-out tests. Sagittal sections of the other three were evaluated by SEM. The bone mineral density (BMD) of the dissected left tibia was measured by dual-energy x-ray absorptiometry. The difference in BMD between the control and ovariectomised tibiae was 35.01 mg/cm2 (95% CI, 26.60 to 43.42). The push-out strength of the HA-coated implants was higher than that of the uncoated implants in both groups (p < 0.0001), but the HA-coated implants of the ovariectomised group had a reduction in push-out strength of 40.3% compared with the control group (p < 0.0001). Our findings suggest that HA-coated implants may improve the fixation of a cementless total hip prosthesis but that the presence of osteoporosis may limit the magnitude of this benefit.  (+info)

Bactericidal activity of photocatalytic TiO(2) reaction: toward an understanding of its killing mechanism. (8/1876)

When titanium dioxide (TiO(2)) is irradiated with near-UV light, this semiconductor exhibits strong bactericidal activity. In this paper, we present the first evidence that the lipid peroxidation reaction is the underlying mechanism of death of Escherichia coli K-12 cells that are irradiated in the presence of the TiO(2) photocatalyst. Using production of malondialdehyde (MDA) as an index to assess cell membrane damage by lipid peroxidation, we observed that there was an exponential increase in the production of MDA, whose concentration reached 1.1 to 2.4 nmol. mg (dry weight) of cells(-1) after 30 min of illumination, and that the kinetics of this process paralleled cell death. Under these conditions, concomitant losses of 77 to 93% of the cell respiratory activity were also detected, as measured by both oxygen uptake and reduction of 2,3,5-triphenyltetrazolium chloride from succinate as the electron donor. The occurrence of lipid peroxidation and the simultaneous losses of both membrane-dependent respiratory activity and cell viability depended strictly on the presence of both light and TiO(2). We concluded that TiO(2) photocatalysis promoted peroxidation of the polyunsaturated phospholipid component of the lipid membrane initially and induced major disorder in the E. coli cell membrane. Subsequently, essential functions that rely on intact cell membrane architecture, such as respiratory activity, were lost, and cell death was inevitable.  (+info)

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  • Titanium alloys are used in aerospace engineering to make very strong and light parts of airplanes. (wikipedia.org)
  • SRI is examining the reaction between hydrogen and metal chlorides, which could produce titanium alloys without multiple complicated steps. (energy.gov)
  • Producing titanium alloys at a cost similar to stainless steel could make light-weight vehicles a cost competitive option for improving vehicle fuel efficiency, which could result in substantial overall fuel savings in the transportation sector. (energy.gov)
  • Recent findings have associated the exposure to iron oxide (Fe 2 O 3 ) and titanium dioxide (TiO 2 ) - NPs widely used in biomedical and clinical research - with pulmonary oxidative stress and inflammation. (frontiersin.org)
  • According to their classification, iron oxide (Fe 2 O 3 ) and titanium dioxide (TiO 2 ) are inorganic materials of natural (geogenic) and anthropogenic (engineered) sources, respectively ( Nowack and Bucheli, 2007 ). (frontiersin.org)
  • Titanium oxide catalysts are some of the most promising photocatalyst candidates for renewable energy storage applications via production of solar fuels. (illinois.edu)
  • To contribute to a molecular-level understanding of the interaction of CO$_{2}$ with titanium oxide, we turn to cluster models in order to circumvent the challenges posed by speciation in the condensed phase. (illinois.edu)
  • The subject products include premium-quality (rotor-grade) titanium sponge that is used in rotating aircraft engine parts and standard-quality (industrial-grade) titanium sponge that is used in aerospace products other than rotating engine parts, in addition to other industrial end uses. (usitc.gov)
  • Most food-grade titanium dioxide contains its anatase modification. (anton-paar.com)
  • The U.S. Food and Drug Administration actually allows manufacturers to use up to 1 percent food-grade titanium dioxide without declaring it on labels. (wordpress.com)
  • abstract = "The effect of anodization on passive dissolution of titanium was studied by measuring titanium levels in peritoneal leukocytes and tissues of laboratory animals with titanium plates implanted into the peritoneal cavity. (elsevier.com)
  • abstract = "This research was aimed at developing a hydroponie recycling system using a visible light- reactive titanium dioxide (TiO 2 ) photocatalyst. (elsevier.com)
  • We have recently demonstrated that titanium dioxide (TiO₂) particles bind to several serum proteins. (nih.gov)
  • Titanium sponge in this instance specifically excludes loose particles of unwrought titanium having a particle size less than 20 mesh (0.84 mm), alloyed or unalloyed briquettes of unwrought titanium metal that contain more than 0.2 percent oxygen on a dry weight basis, and ultra-high purity titanium sponge. (usitc.gov)
  • It should be noted that many titanium particles used in food products are not nanoparticles (defined as smaller than 100 nanometers in diameter). (wordpress.com)
  • Titanium particles inhibit osteoblast adhesion to fibronectin-coated substrates. (unil.ch)
  • Summary: TEHRAN (FNA)- A group of Iranian researchers carried out the photo-catalytic process for the degradation of pigments by adding certain metals such as silver, iron and zinc to titanium dioxide nanoparticles and using the synthesized nanoparticles in visible light. (acronymfinder.com)
  • Having non-toxic chemical properties and superior brightness and opacity, titanium dioxide is increasingly replacing other traditional pigments across different industries. (groupdf.com)
  • The subject products are typically melted down to make titanium ingots before being further processed into various mill products, depending on the intended end use of the final product. (usitc.gov)
  • Titanium levels in the trace range, as measured in the capsular tissues, are likely a result of corrosion. (elsevier.com)
  • Surface treatment of titanium by anodization reduces passive dissolution. (elsevier.com)
  • Group DF - international group of the companies, major investments are concentrated in the nitrogen, titanium and gas businesses. (groupdf.com)
  • Primary production of lightweight metals such as titanium is an energy-intensive and expensive process that results in significant carbon dioxide (CO 2 ) and other emissions. (energy.gov)
  • Lowering the energy consumption, cost, and emissions associated with processing titanium would make it more competitive with incumbent structural metals such as steel. (energy.gov)
  • 2. Petitioner: Titanium Metals Corporation (TIMET), Exton, Pennsylvania. (usitc.gov)

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