2,070 research outputs found

    A Case of Spontaneous Adrenal Hemorrhage in Pregnancy

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    A case study looking at a 25 year old patient at 31 weeks gestation with spontaneous adrenal hemorrhage

    Resistance to Fracture of Two All-Ceramic Crown Materials Following Endodontic Access

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    Statement of problem There is currently no protocol for managing endodontic access openings for all-ceramic crowns. A direct restorative material is generally used to repair the access opening, rendering a repaired crown as the definitive restoration. This endodontic procedure, however, may weaken the restoration or initiate microcracks that may propagate, resulting in premature failure of the restoration. Purpose The purpose of this in vitro study was to evaluate how an endodontic access opening prepared through an all-ceramic crown altered the structural integrity of the ceramic, and the effect of a repair of this access on the load to failure of an all-ceramic crown. Material and methods Twenty-four alumina (Procera) and 24 zirconia (Procera) crowns were fabricated and cemented (Rely X Luting Plus Cement) onto duplicate epoxy resin dies. Twelve crowns of each were accessed to simulate root canal treatment therapy. Surface defects of all accessed specimens were evaluated with an environmental scanning electron microscope. The specimens were repaired with a porcelain repair system (standard adhesive resin/composite resin protocol) and were loaded to failure in a universal testing machine. Observations made visually and microscopically noted veneer delamination from the core, core fracture, shear within the veneer porcelain, or a combination thereof. A Kruskal-Wallis test was used to determine if a significant difference (α=.05) in load to failure existed between the 4 groups, and a Mann-Whitney test with a Bonferroni correction (P Results All specimens exhibited edge chipping around the access openings. Some displayed larger chips within the veneering porcelain, and 4 zirconia crowns showed radial crack formation. There was a significant difference in load to failure among all groups with the exception of the alumina intact and repaired specimens (P=.695). The alumina crowns generally showed fracture of the coping with the veneering porcelain still bonded to the core, whereas the zirconia copings tended not to fracture but experienced veneering porcelain delamination. Conclusion Endodontic access through all-ceramic crowns resulted in a significant loss of strength in the zirconia specimens but not in the alumina specimens

    Prevalence, trajectories, and determinants of television viewing time in an ethnically diverse sample of young children from the UK

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    BACKGROUND: Excessive screen viewing in early childhood is associated with poor physical and psycho-social health and poor cognitive development. This study aimed to understand the prevalence, trajectory and determinants of television viewing time in early childhood to inform intervention development. METHODS: In this prospective longitudinal study, mothers of 1558 children (589 white British, 757 Pakistani heritage, 212 other ethnicities) completed questionnaires when their children were approximately 6, 12, 18, 24 and 36 months old. Mothers answered questions about their own and their child's TV-time. TV-time trajectories were estimated by linear longitudinal multilevel modeling, potential determinants were considered in models. RESULTS: The modelled trajectory estimated that 75% of children aged 12 months exceeded guidelines of zero screen-time. At 12 months of age an accelerated increase in TV-time was observed (2 h/day by 30 months old). For every hour of mothers' TV-time and every hour the TV was on in the home, children's TV-time was 8 min and 1 min higher respectively at 6 months old (P < 0.05), and 15 min and 3 min higher respectively at 36 months old (P < 0.05). Children whose mothers did not agree that it was important their child did not watch too much TV, had 17 min more TV-time than their counterparts (P < 0.05). Children of first time mothers had 6 min more TV-time (P < 0.05). At 12 months of age, children of mothers experiencing stress watched 8 min more TV (P < 0.05). By 36 months, children of Pakistani heritage mothers had 22 min more TV-time than those of white British mothers (P < 0.05), and an additional 35 min of TV-time if their mother was not born in the UK (P < 0.05). CONCLUSIONS: High levels of TV-time were prevalent. Intervention developers should consider targeting interventions before 12 months of age. Modifiable determinants included mothers' own TV-time, the time the television is on in the home and mothers' attitude towards child TV-time. These behaviours may be key components to address in interventions for parents. Mothers experiencing stress, first time mothers, and Pakistani heritage mothers (particularly those born outside of the UK), may be priority groups for intervention

    Profile of the most common complaints for five health professions in Australia

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    © 2019 AHHA. Objective: The aims of this study were to profile the most common complaints and to examine whether any demographic factors are associated with receiving a complaint for five health professions in Australia. Methods: A national cohort study was conducted for all complaints received for medicine, nursing/midwifery, dentistry, pharmacy and psychology from 1 July 2012 to 31 December 2013 (18 months). Data were collected from the Australian Health Practitioner Regulation Agency (AHPRA), the New South Wales (NSW) Health Professional Councils' Authority and the NSW Health Care Complaints Commission. The frequency and risk of complaints were summarised for the five professions and by demographic information. Results: There were 545 283 practitioners registered with AHPRA between 1 July 2012 and 31 December 2013, consisting of 20 935 dentists, 101 066 medical practitioners, 363 040 nurses/midwives, 28 370 pharmacists and 31 872 psychologists. During the study period there were 12 616 complaints, corresponding to an annual rate of 1.5 per 100 practitioners. Complaints were most common for doctors and dentists (5% per annum per practitioner) and least common for nurses/midwives (0.5% per annum per practitioner). Sex (P < 0.01), age (P < 0.01) and country of birth (P < 0.01) were all associated with risk of complaint. The most common complaints were clinical care (44% of all complaints), medication (10%) and health impairment of the practitioner (8%). Types of complaints varied by profession, sex and age. Conclusions: The risk of a complaint is low, but varies by profession and demographics. The types of complaints also vary by profession and demographics. Differences between professions is most likely driven by their different work tasks and work environments. What is already known on this subject?: Although complaints are summarised annually from state and national health regulators, no overall national summary of complaints across professions exists. Thus, it is difficult to examine which complaints are most common, how professions differ from each other or what factors may be associated with risk and type of complaint. Previous studies have primarily focused on a single profession, such as medicine, where, for example, the number of prior complaints, sex, doctor speciality and age have been found to be associated with recurrent complaints. What does this paper add?: This paper is the first of this kind to provide a national summary of all complaints from five of the most common health professions in Australia. We found that regardless of profession, men were at least twice as likely to have a complaint made against them than women. We also found that the types of complaint differed between men and women. There were similarities across professions for the most common types of complaints, but clear differences between professions were also noted. Not surprising, clinical care was typically the most common type of complaint for the five professions, but somewhat surprising was the inclusion of health impairment as one of the most common types of complaints. What are the implications for practitioners?: Identifying the most common complaints, and the factors associated with these, may assist practitioners to understand their risk(s) of complaint and could potentially assist educators and regulators develop education programs that help reduce complaints

    Extensive Spectroscopy and Photometry of the Type IIP Supernova 2013ej

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    We present extensive optical (UBVRIUBVRI, grizg'r'i'z', and open CCD) and near-infrared (ZYJHZYJH) photometry for the very nearby Type IIP SN ~2013ej extending from +1 to +461 days after shock breakout, estimated to be MJD 56496.9±0.356496.9\pm0.3. Substantial time series ultraviolet and optical spectroscopy obtained from +8 to +135 days are also presented. Considering well-observed SNe IIP from the literature, we derive UBVRIJHKUBVRIJHK bolometric calibrations from UBVRIUBVRI and unfiltered measurements that potentially reach 2\% precision with a BVB-V color-dependent correction. We observe moderately strong Si II λ6355\lambda6355 as early as +8 days. The photospheric velocity (vphv_{\rm ph}) is determined by modeling the spectra in the vicinity of Fe II λ5169\lambda5169 whenever observed, and interpolating at photometric epochs based on a semianalytic method. This gives vph=4500±500v_{\rm ph} = 4500\pm500 km s1^{-1} at +50 days. We also observe spectral homogeneity of ultraviolet spectra at +10--12 days for SNe IIP, while variations are evident a week after explosion. Using the expanding photosphere method, from combined analysis of SN 2013ej and SN 2002ap, we estimate the distance to the host galaxy to be 9.00.6+0.49.0_{-0.6}^{+0.4} Mpc, consistent with distance estimates from other methods. Photometric and spectroscopic analysis during the plateau phase, which we estimated to be 94±794\pm7 days long, yields an explosion energy of 0.9±0.3×10510.9\pm0.3\times10^{51} ergs, a final pre-explosion progenitor mass of 15.2±4.215.2\pm4.2~M_\odot and a radius of 250±70250\pm70~R_\odot. We observe a broken exponential profile beyond +120 days, with a break point at +183±16183\pm16 days. Measurements beyond this break time yield a 56^{56}Ni mass of 0.013±0.0010.013\pm0.001~M_\odot.Comment: 29 pages, 23 figures, 15 tables, Published in The Astrophisical Journa

    Complex exon-intron marking by histone modifications is not determined solely by nucleosome distribution

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    It has recently been shown that nucleosome distribution, histone modifications and RNA polymerase II (Pol II) occupancy show preferential association with exons (“exon-intron marking”), linking chromatin structure and function to co-transcriptional splicing in a variety of eukaryotes. Previous ChIP-sequencing studies suggested that these marking patterns reflect the nucleosomal landscape. By analyzing ChIP-chip datasets across the human genome in three cell types, we have found that this marking system is far more complex than previously observed. We show here that a range of histone modifications and Pol II are preferentially associated with exons. However, there is noticeable cell-type specificity in the degree of exon marking by histone modifications and, surprisingly, this is also reflected in some histone modifications patterns showing biases towards introns. Exon-intron marking is laid down in the absence of transcription on silent genes, with some marking biases changing or becoming reversed for genes expressed at different levels. Furthermore, the relationship of this marking system with splicing is not simple, with only some histone modifications reflecting exon usage/inclusion, while others mirror patterns of exon exclusion. By examining nucleosomal distributions in all three cell types, we demonstrate that these histone modification patterns cannot solely be accounted for by differences in nucleosome levels between exons and introns. In addition, because of inherent differences between ChIP-chip array and ChIP-sequencing approaches, these platforms report different nucleosome distribution patterns across the human genome. Our findings confound existing views and point to active cellular mechanisms which dynamically regulate histone modification levels and account for exon-intron marking. We believe that these histone modification patterns provide links between chromatin accessibility, Pol II movement and co-transcriptional splicing

    Numerical Relativity Using a Generalized Harmonic Decomposition

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    A new numerical scheme to solve the Einstein field equations based upon the generalized harmonic decomposition of the Ricci tensor is introduced. The source functions driving the wave equations that define generalized harmonic coordinates are treated as independent functions, and encode the coordinate freedom of solutions. Techniques are discussed to impose particular gauge conditions through a specification of the source functions. A 3D, free evolution, finite difference code implementing this system of equations with a scalar field matter source is described. The second-order-in-space-and-time partial differential equations are discretized directly without the use first order auxiliary terms, limiting the number of independent functions to fifteen--ten metric quantities, four source functions and the scalar field. This also limits the number of constraint equations, which can only be enforced to within truncation error in a numerical free evolution, to four. The coordinate system is compactified to spatial infinity in order to impose physically motivated, constraint-preserving outer boundary conditions. A variant of the Cartoon method for efficiently simulating axisymmetric spacetimes with a Cartesian code is described that does not use interpolation, and is easier to incorporate into existing adaptive mesh refinement packages. Preliminary test simulations of vacuum black hole evolution and black hole formation via scalar field collapse are described, suggesting that this method may be useful for studying many spacetimes of interest.Comment: 18 pages, 6 figures; updated to coincide with journal version, which includes some expanded discussions and a new appendix with a stability analysis of a simplified problem using the same discretization scheme described in the pape

    Association of nucleoid proteins with coding and non-coding segments of the Escherichia coli genome

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    The Escherichia coli chromosome is condensed into an ill-defined structure known as the nucleoid. Nucleoid-associated DNA-binding proteins are involved in maintaining this structure and in mediating chromosome compaction. We have exploited chromatin immunoprecipitation and high-density microarrays to study the binding of three such proteins, FIS, H-NS and IHF, across the E.coli genome in vivo. Our results show that the distribution of these proteins is biased to intergenic parts of the genome, and that the binding profiles overlap. Hence some targets are associated with combinations of bound FIS, H-NS and IHF. In addition, many regions associated with FIS and H-NS are also associated with RNA polymerase
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