3,376 research outputs found
A near-field study on the transition from localized to propagating plasmons on 2D nano-wedges
In this manuscript we report on a near-feld study of two-dimensional
plasmonic gold nano-wedges using electron energy loss spectroscopy in
combination with scanning transmission electron microscopy, as well as
discontinuous Galerkin time-domain computations. With increasing nano-wedge
size, we observe a transition from localized surface plasmons on small
nano-wedges to non-resonant propagating surface plasmon polaritons on large
nano-wedges. Furthermore we demonstrate that nano-wedges with a groove cut can
support localized as well as propagating plasmons in the same energy range
Isolation and Characterization of Microbial Pathogens Found in Chickens
The bacterial content of retail chicken is a topic of growing concern. Chicken processing plants are under increasingly strict regulations to prevent contamination. Likewise, increasing controversy is being directed towards chicken farmers concerning cleanliness and the use of antibiotics in raising chickens, as it may lead to antibiotic resistance. There is legitimate concern surrounding the many possible pathogens associated with chicken, let alone the recent trend of bacteria with heightened resistance to antibiotics. This project was carried out with the purpose of the identification and characterization of bacteria found in chicken from local supermarkets. As multiple bacterial species were expected to be encountered, successful identification of at least one species was paramount for the continuation of this project prior to examining bacteria for antibiotic resistance and virulence factors
Immunological mechanisms in specific immunotherapy
Specific immunotherapy (SIT) represents the only curative treatment of allergy and is, therefore, of particular interest for immunological and pharmacological research. The current understanding of immunological mechanisms underlying SIT focuses on regulatory T cells (T regs), which balance Th1 and Th2 effector functions. This ensures that allergens are recognized, but tolerated by the immune system. There is clear evidence that SIT restores the disturbed balance of T regs and effector cells in allergic patients. Current efforts are focused to improve SIT regimens to make them more applicable in atopy and asthma. The current review provides an overview on the mechanisms of SIT and possible adjuvant treatment strategies on the background of the T reg concep
Evidence for lysosomal enzyme recognition by human fibroblasts via a phosphorylated carbohydrate moiety
Photophysics, Molecular Reorientation in Solution and X-Ray Structure of a New Fluorescent Probe 1,7-Diazaperylene
A new fluorescent molecule 1,7-diazaperylene (DP) has been investigated by means of time-resolved and steady-state polarized fluorescence spectroscopy, as well as X-ray spectroscopy. Absorption and fluorescence spectra of DP in solution are similar to those of perylene. However, absorption and fluorescence spectra of 2,8-dimethoxy DP and 2,8-dipentyloxy DP in solution are red-shifted by ca. 55 nm relative to perylene. The fluorescence decay of DP is exponential with a lifetime of 5.1 ns in ethanol, 4.9 ns in glycerol and 4.3 ns in paraffin oil. The radiative lifetime in ethanol was calculated to be 6.3 ns for DP, 8.0 ns for 2,8-dimethoxy DP and 7.6 ns for 2,8-dipentyloxy DP. The calculated fluorescence quantum yields of 0.8 for DP and its alkoxy derivatives in ethanol, are in good agreement with those obtained from measurements. The calculated Förster radius is 37.2 ± 1 Ă
for DP and 41.9 ± 1 Ă
for its alkoxy derivatives in ethanol. Examining the S0 S1 transition, we obtain a limiting fluorescence anisotropy of r0 0.38 for DP and its alkoxy derivatives. The rotational rates of DP in paraffin oil and glycerol were compared to that of perylene. In paraffin oil both molecules show an almost identical biexponential decay of the fluorescence anisotropy, which is compatible with a rotational motion like an oblate ellipsoid. The fluorescence anisotropy is monoexponential for DP in glycerol, and DP appears to rotate like a spherical particle while perylene in glycerol appears to rotate like an oblate ellipsoid. Moreover, the rotational diffusion constant, corresponding to rotation about an axis in the aromatic plane (D), is the same for both DP and perylene in glycerol
Plasma-deposited AgOx-doped TiOx coatings enable rapid antibacterial activity based on ROS generation
Abstract To enable a rapid-acting antibacterial mechanism without the release of biocidal substances, TiO2 catalysts have been considered based on the generation of reactive oxygen species (ROS). Doping with dissimilar metals generates electron-hole pairs with narrow band gaps promoting the production of ROS. Here, plasma technology is investigated to deposit Ag nano islets on defective TiOx films, stabilized by plasma postoxidation suppressing Ag ion release. Importantly, ROS generation is maintained upon storage in the dark yet with diminishing efficacy; however, it can be restored by exposure to visible light. The rapid-acting antibacterial properties are found to strongly correlate with ROS generation, which can even be maintained by functionalization with hydrophobic plasma polymer films. The cytocompatible coatings offer promising applications for implants and other medical devices
safety, feasibility, and metabolic response
Background Intensive care unit (ICU)-acquired weakness in critically ill
patients is a common and significant complication affecting the course of
critical illness. Whole-body vibration is known to be effective muscle
training and may be an option in diminishing weakness and muscle wasting.
Especially, patients who are immobilized and not available for active
physiotherapy may benefit. Until now whole-body vibration was not investigated
in mechanically ventilated ICU patients. We investigated the safety,
feasibility, and metabolic response of whole-body vibration in critically ill
patients. Methods We investigated 19 mechanically ventilated, immobilized ICU
patients. Passive range of motion was performed prior to whole-body vibration
therapy held in the supine position for 15 minutes. Continuous monitoring of
vital signs, hemodynamics, and energy metabolism, as well as intermittent
blood sampling, took place from the start of baseline measurements up to 1
hour post intervention. We performed comparative longitudinal analysis of the
phases before, during, and after intervention. Results Vital signs and
hemodynamic parameters remained stable with only minor changes resulting from
the intervention. No application had to be interrupted. We did not observe any
adverse event. Whole-body vibration did not significantly and/or clinically
change vital signs and hemodynamics. A significant increase in energy
expenditure during whole-body vibration could be observed. Conclusions In our
study the application of whole-body vibration was safe and feasible. The
technique leads to increased energy expenditure. This may offer the chance to
treat patients in the ICU with whole-body vibration. Further investigations
should focus on the efficacy of whole-body vibration in the prevention of ICU-
acquired weakness. Trial registration Applicability and Safety of Vibration
Therapy in Intensive Care Unit (ICU) Patients. ClinicalTrials.gov NCT01286610.
Registered 28 January 2011
A new paraclinical CSF marker for hypoxiaâlike tissue damage in multiple sclerosis lesions
Recent studies on the immunopathology of multiple sclerosis revealed a heterogeneity in the patterns of demyelination, suggesting interindividual differences in the mechanism responsible for myelin destruction. One of these patterns of demyelination, characterized by oligodendrocyte dystrophy and apoptosis, closely mimics myelin destruction in acute white matter ischaemia. In the course of a systematic screening for virus antigen expression in multiple sclerosis brains, we identified a monoclonal antibody against canine distemper virus, which detects a crossâreactive endogenous brain epitope, highly expressed in this specific subtype of actively demyelinating multiple sclerosis lesions with little or no immunoreactivity in other active multiple sclerosis cases. The respective epitope, which is a phosphorylationâdependent sequence of one or more proteins of 50, 70 and 115kDa, is also expressed in a subset of active lesions of different virusâinduced inflammatory brain diseases, but is present most prominently and consistently in acute lesions of white matter ischaemia. Its presence is significantly associated with nuclear expression of hypoxiaâinducible factorâ1α within the lesions of both inflammatory and ischaemic brain diseases. The respective epitope is liberated into the CSF and, thus, may become a useful diagnostic tool to identify clinically a defined multiple sclerosis subtyp
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