9,253 research outputs found

    Supernumerary teeth in a sample of South African dental patients

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    Supernumerary teeth (SNT) are often associated with malocclusions. Data on SNT in the South African population are not well documented. To determine the prevalence, distribution of characteristics and any associated complications of SNT in a South African sample of dental patients. The study was retrospective, cross-sectional and descriptive. Method: Orthopantomographs of 12,005 dental patients were reviewed for the presence of SNT. The number, morphology, location, eruption status and orientation of SNT were assessed. Associated orthodontic problems were noted. The prevalence rate was 2.48%. No sexual dimorphism in the distribution of SNT was noted. Types of SNT tabulated were: supplementary, conical, tuberculate and odontoma. Maxilla demonstrated a higher predilection for SNT. Variation in the distribution of SNT in the anterior, premolar and molar regions in each jaw and across jaws was statistically significant. Relationship of eruption status to the morphology and orientation of SNT was of significance. Malocclusions noted were displacement and impaction of adjacent teeth. From an orthodontic perspective, presence of SNT may compromise tooth movement and space closure in patients. Additionally, as majority of SNT in this population were in the maxillary molar and mandibular premolar regions, caution is advised when planning the placement of orthodontic implants in these regions

    Quaternary Stratigraphy in Northwestern Maine: A Progress Report

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    A preliminary Quaternary stratigraphy for northwestern Maine can be assembled from interpretation of ice-flow indicators (dispersal and erosional), exposed sections, and drill-hole logs. Evidence from the ice-flow indicators delineates at least four regions each with different ice-flow histories. The distribution of these regions may result from an eastward invasion of Laurentide source ice during the early portion of the late Wisconsinan and subsequent development of a local ice dome during the closing portion of the Late Wisconsinan substage. Exposed sections contribute the following probable sequence of events to the stratigraphy: 1) deposition of alluvial fans, 2) deposition of a gray compact till beneath eastward flowing (Laurentide) ice, 3) deposition of a brown till beneath northward flowing local ice, 4) deglaciation by a southward retreating ice margin. These events appear continuous and have all been provisionally assigned a Late Wisconsinan age. Drill-hole logs confirm the sequence derived from the exposed sections and allow extension of the Quaternary stratigraphy. The drill-log data show three associated groups of sediments that may in turn result from at least three separate ice margin advances and recessions. The uppermost group of sediments is correlated with those found in exposed sections. The position of the drill-hole logs in an over-deepened basin suggest erosion by at least one even earlier glaciation.À partir de l'interprĂ©tation des indicateurs de l'Ă©coulement glaciaire (de dispersion et d'Ă©rosion), des coupes naturelles et des rĂ©sultats des forages, on a tentĂ© d'Ă©tablir la stratigraphie prĂ©liminaire du Quaternaire pour le nord du Maine. Les renseignements tirĂ©s des indicateurs de l'Ă©coulement glaciaire ont permis de circonscrire au moins quatre rĂ©gions, chacune d'elles prĂ©sentant un processus diffĂ©rent d'Ă©coulement glaciaire. La rĂ©partition des rĂ©gions est probablement le rĂ©sultat de la progression vers l'est des glaces laurentidiennes au dĂ©but du Wisconsinien supĂ©rieur et de la formation subsĂ©quente d'un dĂŽme local Ă  la fin du Wisconsinien supĂ©rieur. Les coupes naturelles ont permis de reconstituer la sĂ©quence d'Ă©vĂ©nements suivante : 1 ) formation de cĂŽnes de dĂ©jection; 2) dĂ©pĂŽt d'un till gris compact sous une des glaces laurentidiennes s'Ă©coulant vers l'est; 3) dĂ©pĂŽt d'un till brun sous les glaces locales s'Ă©coulant vers le nord; 4) dĂ©glaciation rĂ©sultant du retrait de la marge glaciaire vers le sud. Ces Ă©vĂ©nements semblent s'ĂȘtre dĂ©roulĂ©s de façon continue; on les attribue du moins provisoirement au Wisconsinien supĂ©rieur. Les rĂ©sultats des forages confirment la sĂ©quence reconstituĂ©e grĂące aux coupes naturelles et permettent mĂȘme de prolonger la stratigraphie du Quaternaire. Les donnĂ©es de forage dĂ©montrent la prĂ©sence de trois groupes associĂ©s de sĂ©diments qui, Ă  leur tour, sont le rĂ©sultat d'au moins trois rĂ©currences et trois rĂ©cessions de la marge glaciaire. Le groupe supĂ©rieur correspond aux sĂ©diments observĂ©s dans les coupes. Les rĂ©sultats de forage dans un bassin surcreusĂ© laissont croire qu'au moins une glaciation antĂ©rieure y a laissĂ© des traces d'Ă©rosion.Eine vorlĂ ufige Stratigraphie fur Nord-West Maine im Quatemar kann durch Interpretation der Eis-FluB Indikatoren (Dispersion und Erosion), der natĂčrlichen Schnitte und der Bohrergebnisse erstellt werden. Durch die Eis-RuB Indikatoren ergeben sich mindestens vier Gebiete mit jeweils unterschiedlicher Eis-FluB Vergangenheit. Die Verteilung dieser Gebiete hat wohl ihren Ursprung im Eindringen von Laurentischem Quell-Eis in ĂŽstlicher Richtung wĂ hrend des Beginns des spĂ ten Wisconsin und der darauf folgenden Entwicklung eines lokalen Eis-Doms wĂ hrend der AbschluBphase des spĂąten Wisconsin. Die natĂčrlichen Schnitte ergeben die folgende mĂŽgliche Abfolge der Ereignisse fur die Stratigraphie; 1) Ablagerung von Alluvialkegeln, 2) Ablagerung eines grauen kompakten Tills unter ostwĂ rts flieBendem (Laurentischem) Eis, 3) Ablagerung eines braunen Tills unter nordwĂąrts flieBendem lokalem Eis, 4) Enteisung durch die sĂčdwĂ rts zurĂčckweichende Eisgrenze. DiĂšse Ereignisse scheinen kontinuierlich abgelaufen zu sein und sind aile vorlĂ ufig dem spĂąten Wisconsin zugeschrieben worden. Die Bohrergebnisse bestĂ tigen die aus den natĂčrlichen Schnitten gewonnene Abfolge und erlauben eine Ausdehnung der Stratigraphie des Quatemar. Die Bohrdaten zeigen drei Gruppen von Sedimenten, die ihrerseits ihren Ursprung in mindestens drei unterschiedlichen VorstoB- und RĂčckzugs-Phasen der Eisgrenze haben. Die oberste Gruppe der Sedimente steht in Wechselbeziehung mit den in den natĂčrlichen Schnitten gefundenen Sedimenten. Bohrergebnissg in einom ĂčbGrtieften Becken lassen vermuten, daB zumindest eine frĂčhre Vereisung Erosionsspuren hinterlassen hat

    Flow field designs developed by comprehensive CFD model decrease system costs of vanadium redox-flow batteries

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    Different flow field designs are known for vanadium redox-flow batteries (VFB). The best possible design to fulfil a variety of target parameters depends on the boundary conditions. Starting from an exemplary interdigitated flow field design, its channel and land dimensions are varied to investigate the impact on pressure drop, channel volume, flow uniformity and limiting current density. To find a desirable compromise between these several partly contrary requirements, the total costs of the VFB system are evaluated in dependence of the flow field’s dimensions. The total costs are composed of the electrolyte, production and component costs. For those, the production technique (injection moulding or milling), the pump and nominal power density as well as depth of discharge are determined. Finally, flow field designs are achieved, which lead to significantly reduced costs. The presented method is applicable for the design process of other flow fields and types of flow batteries

    Climate change, pollution, deforestation and mental health: research trends, gaps and ethical considerations

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    Abstract Climate change, pollution, and deforestation have a negative impact on global mental health. There is an environmental justice dimension to this challenge as wealthy people and high‐income countries are major contributors to climate change and pollution, while poor people and low‐income countries are heavily affected by the consequences. Using state‐of‐the art data mining, we analyzed and visualized the global research landscape on mental health, climate change, pollution and deforestation over a 15‐year period. Metadata of papers were exported from PubMed¼, and both relevance and relatedness of terms in different time frames were computed using VOSviewer. Co‐occurrence graphs were used to visualize results. The development of exemplary terms over time was plotted separately. The number of research papers on mental health and environmental challenges is growing in a linear fashion. Major topics are climate change, chemical pollution, including psychiatric medication in wastewater, and neurobiological effects. Research on specific psychiatric syndromes and diseases, particularly on their ethical and social aspects is less prominent. There is a growing body of research literature on links between mental health, climate change, pollution, and deforestation. This research provides a graphic overview to mental healthcare professionals and political stakeholders. Social and ethical aspects of the climate change‐mental health link have been neglected, and more research is needed

    Perforation of the Schneiderian membrane during sinus floor elevation: a risk factor for long-term success of dental implants?

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    Purpose: In cases of highly atrophic alveolar ridges, augmentation procedures became a frequent procedure to gain optimal conditions for dental implants. Especially in the maxilla sinus floor elevation procedures represent the gold standard pre-prosthetic and mainly successful procedure. The perforation of the Schneiderian is one of the most common complications. The aim of this study was to evaluate whether the intraoperative perforation of the Schneiderian membrane has an impact on long-term implant success. Methods: Thirty-four patients from a former study collective of the years 2005 and 2006 with a total of 41 perforations were invited for a follow-up examination to determine the long-term success rates after sinus floor elevation and subsequent implantation. Results: Twenty-one patients with 25 perforations were subsequently re-evaluated. One implant was lost due to a of periimplant infection after 232 days, resulting in an implant survival rate of 98% within a mean follow-up period of 8.9 years (± 1.5 years). Conclusion: Regarding the long-term success, there was no increased risk for implant failure or other persisting complications, e.g., sinusitis, after intraoperative perforation during sinus floor elevation in this study

    Psychopathological Course Typology in Schizophrenia Spectrum Disorders: A Heuristic Approach in a Sample of 100 Patients

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    Background: Despite several previous attempts at subtyping schizophrenia, a typology that reflects neurobiological knowledge and reliably predicts course and outcome is lacking. We applied the system-specific concept of the Bern Psychopathology Scale (BPS) to generate a course typology based on three domains: language, affectivity, and motor behaviour. Sampling and Methods: A cohort of 100 patients with schizophrenia or schizoaffective disorders according to DSM-IV criteria underwent psychopathological assessment, and all their available medical records were retrospectively analysed on the basis of the BPS. Results: Overall, 39% of the patients showed dominant abnormalities in only one domain, 37% in two domains, and 24% in all three domains. The motor domain was affected in the majority of patients (76%), followed by affectivity (63%) and language (46%). Eighty-six percent of patients showed a bipolar course pattern in at least one domain. Conclusions: In a retrospective analysis of 100 patient records we described system-specific course patterns of schizophrenia by using a neurobiologically informed psychopathological assessment. The results showed a surprisingly high proportion of bipolar courses and a pattern of pure and mixed subtypes, which speaks for an overlap of domains with regards to psychopathological symptoms. A limitation of this heuristic and retrospective approach is that it was largely based on clinical judgement. Prospective studies with more rigorous threshold definitions are needed to clarify the neurobiological and clinical implications of the proposed reorganization of psychotic disorders. (C) 2016 S. Karger AG, Base

    Orally Active MMP-1 Sparing α-tetrahydropyranyl and α-piperidinyl Sulfone Matrix Metalloproteinase (MMP) Inhibitors with Efficacy in Cancer, Arthritis, and Cardiovascular Disease

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    α-Sulfone-α-piperidine and α-tetrahydropyranyl hydroxamates were explored that are potent inhibitors of MMP’s-2, -9, and -13 that spare MMP-1, with oral efficacy in inhibiting tumor growth in mice and left-ventricular hypertrophy in rats and in the bovine cartilage degradation ex vivo explant system. α-Piperidine 19v (SC-78080/SD-2590) was selected for development toward the initial indication of cancer, while α-piperidine and α-tetrahydropyranyl hydroxamates 19w (SC-77964) and 9i (SC-77774), respectively, were identified as backup compounds

    MMP-13 Selective α-sulfone Hydroxamates: a Survey of P1\u27 Heterocyclic Amide Isosteres

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    Seeking compounds preferentially potent and selective for MMP-13, we reported in the preceding Letter on a series of hydroxamic acids with a flexible benzamide tail groups.(1a) Here, we replace the amide moiety with non-hydrolyzable heterocycles in an effort to improve half-life. We identify a hydroxamate tetrazole 4e that spares MMP-1 and -14, shows \u3e400-fold selectivity versus MMP-8 and \u3e600-fold selectivity versus MMP-2, and has a 4.8 h half-life in rats. X-ray data (1.9 Å) for tetrazole 4c is presented

    MMP-13 Selective Alpha-sulfone Hydroxamates: Identification of Selective P1\u27 Amides

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    Continuing our interest in designing compounds preferentially potent and selective for MMP-13, we report on a series of hydroxamic acids with a flexible amide P1\u27 substituents. We identify an amide which spares both MMP-1 and -14, and shows \u3e500 fold selectivity for MMP-13 versus MMP-2 and -8

    Spatially resolved simulation of a radio frequency driven micro atmospheric pressure plasma jet and its effluent

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    Radio frequency driven plasma jets are frequently employed as efficient plasma sources for surface modification and other processes at atmospheric pressure. The radio-frequency driven micro atmospheric pressure plasma jet (ÎŒ\muAPPJ) is a particular variant of that concept whose geometry allows direct optical access. In this work, the characteristics of the ÎŒ\muAPPJ operated with a helium-oxygen mixture and its interaction with a helium environment are studied by numerical simulation. The density and temperature of the electrons, as well as the concentration of all reactive species are studied both in the jet itself and in its effluent. It is found that the effluent is essentially free of charge carriers but contains a substantial amount of activated oxygen (O, O3_3 and O2(1Δ)_2(^1\Delta)). The simulation results are verified by comparison with experimental data
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