608 research outputs found

    Knowledge of risk and self-protection practices and the degree of influenza hazard from live poultry sales.

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    1. Perceptions of risk from buying live chickens were moderate, but sickness anxieties did not predict buying or touching habits. 2. Buying was strongly predicted by the erroneous belief that cooking is the best means of protection from avian influenza. Health education groups seeking to increase preventive practices to control possible avian influenza outbreaks need to learn from this.published_or_final_versio

    Simultaneous spectral domain OCT and fundus autofluorescence imaging of the macula and microperimetric correspondence after successful repair of rhegmatogenous retinal detachment

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    Background/aims: To evaluate the ultrastructural changes in the macula after successful repair of rhegmatogenous retinal detachment (RRD) using simultaneous spectral domain optical coherence tomography (sdOCT) and fundus autofluorescence (FAF) imaging and to perform functional correlations with microperimetry. Methods: Simultaneous sdOCT and FAF imaging were performed using a combined sdOCT-confocal scanning laser ophthalmoscope (cSLO) system. Microperimetry was performed in a subgroup of these patients. Results: 17 patients with macular-on RRD and 20 with macular-off RRD were recruited. sdOCT images revealed disruption of the external limiting membrane, inner segment/outer segment junction or the Verhoeff membrane in 16 eyes (43.2%). The presence of any or more of these disruptions was significantly associated with a poor postoperative best-corrected visual acuity (BCVA) (p<0.001). Patients with abnormal FAF were also associated with poor postoperative BCVA (p<0.001). However, there was a generally poor correspondence between the localisation of ultrastructural abnormalities as detected by sdOCT and FAF changes. Areas of decreased microperimetric sensitivity corresponded well with the ultrastructural changes and abnormal FAF. Conclusions: FAF changes may lag behind ultrastructural changes in the OCT, some of which may reverse with the passage of time. The present study demonstrates the ultrastructural changes assessed with simultaneous FAF and sdOCT and their relation with visual outcome.published_or_final_versio

    Anion Distribution, Structural Distortion, and Symmetry-Driven Optical Band Gap Bowing in Mixed Halide Cs2SnX6 Vacancy Ordered Double Perovskites.

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    Mixed anion compounds in the Fm3Ì…m vacancy ordered perovskite structure were synthesized and characterized experimentally and computationally with a focus on compounds where A = Cs+. Pure anion Cs2SnX6 compounds were formed with X = Cl, Br, and I using a room temperature solution phase method. Mixed anion compounds were formed as solid solutions of Cs2SnCl6 and Cs2SnBr6 and a second series from Cs2SnBr6 and Cs2SnI6. Single phase structures formed across the entirety of both composition series with no evidence of long-range anion ordering observed by diffraction. A distortion of the cubic A2BX6 structure was identified in which the spacing of the BX6 octahedra changes to accommodate the A site cation without reduction of overall symmetry. Optical band gap values varied with anion composition between 4.89 eV in Cs2SnCl6 to 1.35 eV in Cs2SnI6 but proved highly nonlinear with changes in composition. In mixed halide compounds, it was found that lower energy optical transitions appeared that were not present in the pure halide compounds, and this was attributed to lowering of the local symmetry within the tin halide octahedra. The electronic structure was characterized by photoemission spectroscopy, and Raman spectroscopy revealed vibrational modes in the mixed halide compounds that could be assigned to particular mixed halide octahedra. This analysis was used to determine the distribution of octahedra types in mixed anion compounds, which was found to be consistent with a near-random distribution of halide anions throughout the structure, although some deviations from random halide distribution were noted in mixed iodide-bromide compounds, where the larger iodide anions preferentially adopted trans configurations

    Lumbar intervertebral disc allograft transplantation: long-term mobility and impact on the adjacent segments

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    Purpose: Fresh-frozen intervertebral disc (IVD) allograft transplantation has been successfully performed in the human cervical spine. Whether this non-fusion technology could truly decrease adjacent segment disease is still unknown. This study evaluated the long-term mobility of the IVD-transplanted segment and the impact on the adjacent spinal segments in a goat model. Methods: Twelve goats were used. IVD allograft transplantation was performed at lumbar L4/L5 in 5 goats; the other 7 goats were used as the untreated control (5) and for the supply of allografts (2). Post-operation lateral radiographs of the lumbar spine in the neutral, full-flexion and full-extension positions were taken at 1, 3, 6, 9 and 12 months. Disc height (DH) of the allograft and the adjacent levels was calculated and range of motion (ROM) was measured using the Cobb’s method. The anatomy of the adjacent discs was observed histologically. Results: DH of the transplanted segment was decreased significantly after 3 months but no further reduction was recorded until the final follow-up. No obvious alteration was seen in the ROM of the transplanted segment at different time points with the ROM at 12 months being comparable to that of the untreated control. The DH and ROM in the adjacent segments were well maintained during the whole observation period. At post-operative 12 months, the ROM of the adjacent levels was similar to that of the untreated control and the anatomical morphology was well preserved. Conclusions: Lumbar IVD allograft transplantation in goats could restore the segmental mobility and did not negatively affect the adjacent segments after 12 months.postprin

    Coupling of small leucine-rich proteoglycans to hypoxic survival of a progenitor cell-like subpopulation in Rhesus Macaque intervertebral disc

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    Degeneration of the intervertebral disc (IVD) is a major spinal disorder that associates with neck and back pain. Recent studies of clinical samples and animal models for IVD degeneration have identified cells with multi-potency in the IVD. However, IVD tissue-specific progenitor cells and their niche components are not clear, although degenerated IVD-derived cells possess invitro characteristics of mesenchymal stromal cell (MSCs). Here, we firstly identified the tissue-specific intervertebral disc progenitor cells (DPCs) from healthy Rhesus monkey and report the niche components modulated the survival of DPCs under hypoxia. DPCs possess clonogenicity, multipotency and retain differentiation potential after extended expansion invitro and invivo. In particular, the nucleus pulposus-derived DPCs are sensitive to low oxygen tension and undergo apoptosis under hypoxic conditions due to their inability to induce/stabilize hypoxia-inducible factors (HIF). The presence of small leucine-rich proteoglycans (SLRP), biglycan or decorin, can reduce the susceptibility of DPCs to hypoxia-induced apoptosis via promoting the activation/stabilization of HIF-1α and HIF-2α. As IVD is avascular, we propose SLRPs are niche components of DPCs in IVD homeostasis, providing new insights in progenitor cell biology and niche factors under a hypoxic microenvironment. © 2013 .postprin

    Endoscopic submucosal dissection vs laparoscopic colorectal resection for early colorectal epithelial neoplasia

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    A pan-Asian survey of risk perception, attitudes and practices associated with live animal markets.

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    Key Messages 1. Causal attributions for highly pathogenic avian influenza (HPAI) of the H5N1 virus among live poultry, consumers, retailers and breeders in Vietnam, Thailand, Guangzhou and Hong Kong were studied. 2. Three main themes embodying lay explanation for the causes of H5N1 HPAI emerged: viruses, husbandry-related factors, and vulnerability factors. 3. A deeper understanding of the perceptions of risks, biases, causal attributions, and both the facilitators and barriers to change is needed for planning effective changes in health related behaviour.published_or_final_versio
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