147 research outputs found

    The Effect of ArF-Excimer Laser Irradiation of the Human Enamel Surface on the Bond Strength of Orthodontic Appliances

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    This study investigated enamel laser conditioning as an alternative to acid etching in bracket therapy. In preliminary experiments optimal laser parameters for achieving a bond strength of 6-10 N/mm2 were defined. Enamel surface morphology was assessed and the ablation depth was measured on serial enamel sections. Thirty human molars were exposed to 193 nm ArF-excimer laser radiation (energy density: 260 mJ/cm2) by single pulse application of 23 nanoseconds. Thirty molars were etched with phosphoric acid (37%) for 60 seconds. The brackets from the treated molars and 30 untreated molars were debonded vertically for tensile bond strength measurement. Roughened enamel surfaces were attained by 450 and 900 laser pulses with a mean ablation depth of 10.13 ± 4. 84 μm. After 1-10 laser pulses, the enamel surface appeared intact. The tensile bond strength was 6.63 ± 2 .18 N/mm2 in the laser-treated group (1 pulse), 8.75 ± 3.61 N/mm2 in the acid-etched group, and 4 .61 ± 3.15 N/mm2 in the untreated group. We conclude a laser-selective ablation of the membranous enamel pellicle. Since the irradiated area can be adapted to bracket base and the enamel surface remains morphologically intact, pulsed ArF-excimer laser treatment seems to be superior to the acid etching technique

    The University Münster model surgery system for Orthognathic surgery. Part I – The idea behind

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    Background: We describe a procedure for diagnosis and planning for orthognatic surgery based on international standards. A special 2D planning based on lateral cephalograms (Axis Orbital Marker Lines System) realize a transmission to the SAM 2P articulator (3D) by means of the Axis Orbital Plane. Methods: Former intraoperative measurement of the average height of the LeFort I osteotomy plane relative to the molar occlusal plane allow to construct a virtual osteotomy plane in the lateral cephalogram. This is the basis for the development of the Axis Orbital Marker Lines System (AO-MLS). Results: The AO-MLS is presented graphically, and in detail, with construction guidelines. The system could be integrated into various lateral cephalometric analysis- and surgical prediction schemes. It forms the basis for a standardized transfer of the 2D planning to the 3D planning in the articulator, and vice versa. This procedure makes it possible to generate surgical planning protocols based on the model surgery, which represent the dislocations in the proximity of the real osteotomy planes. Conclusions: The Axis Orbital Marker Lines System (software component) in conjunction with the University Münster Model Surgery System (hardware system) increases the predictability of model operations in orthognathic surgery

    Public Relations Work to Increase Attainability Relating to EMail-Communication

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    The mere allotment of an e-mail address does in no way ensure answering quotas, which could be called sufficient to dependably hand out important information via roundmail. A loss of accessibility through e-mail addresses already provided by the university can be due to various technical problems and personal deficiencies of motivation. Students in particular often use external providers and are often also not on familiar terms with the use of consistent personal e-mail archives, POP-accounts, Web-Mail-Portals and the use of forewarding functions. Special email-courses are being offered within regular further training for staff and students

    Extraktionskonzept bei multiplen vorzeitigen Milchzahnverlusten und horizontaler Verlagerung eines Eckzahnes

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    Eine 9-jährige Patientin stellte sich mit multiplen Stützzoneneinbrüchen durch kariesbedingte vorzeitige Milchzahnverluste, einem vollretinierten, horizontal verlagerten Zahn 33, Mittellinienverschiebung sowie einem Unterkieferengstand zur kieferorthopädischen Beratung vor. Initial wurde im Ober- und Unterkiefer durch das Tragen aktiver Platten ein Fortschreiten der Stützzoneneinbrüche verhindert, Milchzahnextraktionen durchgeführt und auf den verzögerten Durchbruch der Prämolaren gewartet. Im Alter von 10 Jahren wurden die Zähne 14, 24 und 44 extrahiert, sowie die operative Entfernung des verlagerten Zahnes 33 durchgeführt. In einer knapp 2-jährigen Multibracket-Therapie wurden die Zähne 44, 45, 46 mesialisiert und Zahn 44 an Eckzahnposition im 4. Quadranten eingestellt. Die verbleibenden Extraktionslücken wurden geschlossen und die Oberkiefermitte eingestellt

    EMail-Verteiler zur Distribution digitaler Informationen im Zentrum für ZMK-Münster

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    Auf der Basis verschiedener in HTML-Seiten integrierter PHP-Scripte können EMails an vordefinierte Zielgruppen, z.B. an alle Studenten, an alle Mitarbeiter einer Poliklinik oder auch an eine manuell selektierbare individuelle Liste von Personen geschickt werden. Der PHP-Server des Apache-Webserves sorgt für eine augenblickliche, schnelle Distribution ohne Abhängigkeit von Mail-Servern der Universität, persönlichen Providern oder lokalen EMail-Programmen. Digitale Verteiler sind herkömmlichen 'Snail-Mail'-Verteilern in Geschwindigkeit und Qualität weit überlegen und werden diese vermutlich bald vollständig ersetzen können

    Dance Type and Flight Parameters Are Associated with Different Mushroom Body Neural Activities in Worker Honeybee Brains

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    Background: Honeybee foragers can transmit the information concerning the location of food sources to their nestmates using dance communication. We previously used a novel immediate early gene, termed kakusei, to demonstrate that the neural activity of a specific mushroom body (MB) neuron subtype is preferentially enhanced in the forager brain. The sensory information related to this MB neuron activity, however, remained unclear. Methodology/Principal Findings: Here, we used kakusei to analyze the relationship between MB neuron activity and types of foraging behavior. The number of kakusei-positive MB neurons was higher in the round dancers that had flown a short distance than in the waggle dancers that had flown a long distance. Furthermore, the amount of kakusei transcript in the MBs inversely related to the waggle-phase duration of the waggle dance, which correlates with the flight distance. Using a narrow tunnel whose inside was vertically or axially lined, we manipulated the pattern of visual input, which is received by the foragers during flight, and analysed kakusei expression. The amount of kakusei transcript in the MBs was related to the foraging frequency but not to the tunnel pattern. In contrast, the number of kakusei-positive MB neurons was affected by the tunnel patterns, but not related to foraging frequency. Conclusions/Significance: These results suggest that the MB neuron activity depends on the foraging frequency, whereas the number of active MB neurons is related to the pattern of visual input received during foraging flight. Our results sugges

    Distribution of the Octopamine Receptor AmOA1 in the Honey Bee Brain

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    Octopamine plays an important role in many behaviors in invertebrates. It acts via binding to G protein coupled receptors located on the plasma membrane of responsive cells. Several distinct subtypes of octopamine receptors have been found in invertebrates, yet little is known about the expression pattern of these different receptor subtypes and how each subtype may contribute to different behaviors. One honey bee (Apis mellifera) octopamine receptor, AmOA1, was recently cloned and characterized. Here we continue to characterize the AmOA1 receptor by investigating its distribution in the honey bee brain. We used two independent antibodies produced against two distinct peptides in the carboxyl-terminus to study the distribution of the AmOA1 receptor in the honey bee brain. We found that both anti-AmOA1 antibodies revealed labeling of cell body clusters throughout the brain and within the following brain neuropils: the antennal lobes; the calyces, pedunculus, vertical (alpha, gamma) and medial (beta) lobes of the mushroom body; the optic lobes; the subesophageal ganglion; and the central complex. Double immunofluorescence staining using anti-GABA and anti-AmOA1 receptor antibodies revealed that a population of inhibitory GABAergic local interneurons in the antennal lobes express the AmOA1 receptor in the cell bodies, axons and their endings in the glomeruli. In the mushroom bodies, AmOA1 receptors are expressed in a subpopulation of inhibitory GABAergic feedback neurons that ends in the visual (outer half of basal ring and collar regions) and olfactory (lip and inner basal ring region) calyx neuropils, as well as in the collar and lip zones of the vertical and medial lobes. The data suggest that one effect of octopamine via AmOA1 in the antennal lobe and mushroom body is to modulate inhibitory neurons

    Analyzing Childlessness

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    Childlessness has been on the rise in many European societies. In Germany, the UK, Austria, the Netherlands, and Switzerland, childlessness has increased starting with the 1950s cohorts. In these countries, about 20 % of the women born around 1965 will remain childless. In southern Europe and the former state-socialist countries of Central and Eastern Europe, the rise in levels of childlessness is a more recent phenomenon. Yet among younger cohorts in these countries, childlessness has reached levels of 15 % or higher. In this introductory chapter, we summarize the long-term trends in childlessness and discuss the differences between European countries in the prevalence of childlessness. We also outline the structure and the logic of this volume

    Strategies of the honeybee Apis mellifera during visual search for vertical targets presented at various heights: a role for spatial attention?

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    When honeybees are presented with a colour discrimination task, they tend to choose swiftly and accurately when objects are presented in the ventral part of their frontal visual field. In contrast, poor performance is observed when objects appear in the dorsal part. Here we investigate if this asymmetry is caused by fixed search patterns or if bees can use alternative search mechanisms such as spatial attention, which allows flexible focusing on different areas of the visual field. We asked individual honeybees to choose an orange rewarded target among blue distractors. Target and distractors were presented in the ventral visual field, the dorsal field or both. Bees presented with targets in the ventral visual field consistently had the highest search efficiency, with rapid decisions, high accuracy and direct flight paths. In contrast, search performance for dorsally located targets was inaccurate and slow at the beginning of the test phase, but bees increased their search performance significantly after a few learning trials: they found the target faster, made fewer errors and flew in a straight line towards the target. However, bees needed thrice as long to improve the search for a dorsally located target when the target's position changed randomly between the ventral and the dorsal visual field. We propose that honeybees form expectations of the location of the target's appearance and adapt their search strategy accordingly. Different possible mechanisms of this behavioural adaptation are discussed.L.M. was recipient of a DOC-fFORTE fellowship of the Austrian Academy of Science at the Department of Integrative Zoology, University of Vienna. L.C. is supported by an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award
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