150 research outputs found
Low-dose oral immunization with lyophilized tissue of herbicide-resistant lettuce expressing hepatitis B surface antigen for prototype plant-derived vaccine tablet formulation
Efficient immunization against hepatitis B virus (HBV) and other pathogens with plant-based oral vaccines requires appropriate plant expressors and the optimization of vaccine compositions and administration protocols. Previous immunization studies were mainly based on a combination of the injection of a small surface antigen of HBV (S-HBsAg) and the feeding with raw tissue containing the antigen, supplemented with an adjuvant, and coming from plants conferring resistance to kanamycin. The objective of this study was to develop a prototype oral vaccine formula suitable for human immunization. Herbicide-resistant lettuce was engineered, stably expressing through progeny generation micrograms of S-HBsAg per g of fresh weight and formed into virus-like particles (VLPs). Lyophilized tissue containing a relatively low, 100-ng VLP-assembled antigen dose, administered only orally to mice with a long, 60-day interval between prime and boost immunizations and without exogenous adjuvant, elicited mucosal and systemic humoral anti-HBs responses at the nominally protective level. Lyophilized tissue was converted into tablets, which preserved S-HBsAg content for at least one year of room temperature storage. The results of the study provide indications on immunization methodology using a durable, efficacious, and convenient plant-derived prototype oral vaccine against hepatitis B
The H.E.S.S. Galactic plane survey
We present the results of the most comprehensive survey of the Galactic plane in very high-energy (VHE) γ-rays, including a public release of Galactic sky maps, a catalog of VHE sources, and the discovery of 16 new sources of VHE γ-rays. The High Energy Spectroscopic System (H.E.S.S.) Galactic plane survey (HGPS) was a decade-long observation program carried out by the H.E.S.S. I array of Cherenkov telescopes in Namibia from 2004 to 2013. The observations amount to nearly 2700 h of quality-selected data, covering the Galactic plane at longitudes from ℓ = 250° to 65° and latitudes |b|≤ 3°. In addition to the unprecedented spatial coverage, the HGPS also features a relatively high angular resolution (0.08° ≈ 5 arcmin mean point spread function 68% containment radius), sensitivity (≲1.5% Crab flux for point-like sources), and energy range (0.2–100 TeV). We constructed a catalog of VHE γ-ray sources from the HGPS data set with a systematic procedure for both source detection and characterization of morphology and spectrum. We present this likelihood-based method in detail, including the introduction of a model component to account for unresolved, large-scale emission along the Galactic plane. In total, the resulting HGPS catalog contains 78 VHE sources, of which 14 are not reanalyzed here, for example, due to their complex morphology, namely shell-like sources and the Galactic center region. Where possible, we provide a firm identification of the VHE source or plausible associations with sources in other astronomical catalogs. We also studied the characteristics of the VHE sources with source parameter distributions. 16 new sources were previously unknown or unpublished, and we individually discuss their identifications or possible associations. We firmly identified 31 sources as pulsar wind nebulae (PWNe), supernova remnants (SNRs), composite SNRs, or gamma-ray binaries. Among the 47 sources not yet identified, most of them (36) have possible associations with cataloged objects, notably PWNe and energetic pulsars that could power VHE PWNe.H.E.S.S. Collaboration: H. Abdalla … R. Blackwell … P. DeWilt … J. Hawkes … J. Lau … N. Maxted … G. Rowell … F. Voisin … et al
Abnormal ghrelin secretion contributes to gastrointestinal symptoms in multiple system atrophy patients
Integrating teamwork, clinician occupational well-being and patient safety – development of a conceptual framework based on a systematic review
BACKGROUND: There is growing evidence that teamwork in hospitals is related to both patient outcomes and clinician occupational well-being. Furthermore, clinician well-being is associated with patient safety. Despite considerable research activity, few studies include all three concepts, and their interrelations have not yet been investigated systematically. To advance our understanding of these potentially complex interrelations we propose an integrative framework taking into account current evidence and research gaps identified in a systematic review. METHODS: We conducted a literature search in six major databases (Medline, PsycArticles, PsycInfo, Psyndex, ScienceDirect, and Web of Knowledge). Inclusion criteria were: peer reviewed papers published between January 2000 and June 2015 investigating a statistical relationship between at least two of the three concepts; teamwork, patient safety, and clinician occupational well-being in hospital settings, including practicing nurses and physicians. We assessed methodological quality using a standardized rating system and qualitatively appraised and extracted relevant data, such as instruments, analyses and outcomes. RESULTS: The 98 studies included in this review were highly diverse regarding quality, methodology and outcomes. We found support for the existence of independent associations between teamwork, clinician occupational well-being and patient safety. However, we identified several conceptual and methodological limitations. The main barrier to advancing our understanding of the causal relationships between teamwork, clinician well-being and patient safety is the lack of an integrative, theory-based, and methodologically thorough approach investigating the three concepts simultaneously and longitudinally. Based on psychological theory and our findings, we developed an integrative framework that addresses these limitations and proposes mechanisms by which these concepts might be linked. CONCLUSION: Knowledge about the mechanisms underlying the relationships between these concepts helps to identify avenues for future research, aimed at benefiting clinicians and patients by using the synergies between teamwork, clinician occupational well-being and patient safety. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12913-016-1535-y) contains supplementary material, which is available to authorized users
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Optical properties of UBe13, CeBe13, and ThBe13.
We report the results of optical reflectivity measurements on MBe13(M=U,Ce,Th) from 0.1 to 30 eV at T=300 K. The dielectric function ()=1+i2() is determined from a Kramers-Kronig analysis of the data. The intraband and interband contributions to () were separated via a low-energy Drude analysis. The following free-carrier plasma frequencies were obtained: p(UBe13)=5.9 eV, p(CeBe13)=5.3 eV, and p(ThBe13)=4.4 eV. Estimated values for the optical mass of the free carriers fall in the range
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