1,271 research outputs found
Self-consistent bounces in two dimensions
We compute bounce solutions describing false vacuum decay in a Phi**4 model
in two dimensions in the Hartree approximation, thus going beyond the usual
one-loop corrections to the decay rate. We use zero energy mode functions of
the fluctuation operator for the numerical computation of the functional
determinant and the Green's function. We thus avoid the necessity of
discretizing the spectrum, as it is necessary when one uses numerical
techniques based on eigenfunctions. Regularization is performed in analogy of
standard perturbation theory; the renormalization of the Hartree approximation
is based on the two-particle point-irreducible (2PPI) scheme. The iteration
towards the self-consistent solution is found to converge for some range of the
parameters. Within this range we find the corrections to the leading one-loop
approximation to be relatively small, not exceeding one order of magnitude in
the total transition rate.Comment: 30 pages, 12 figure
One-loop corrections to the metastable vacuum decay
We evaluate the one-loop prefactor in the false vacuum decay rate in a theory
of a self interacting scalar field in 3+1 dimensions. We use a numerical
method, established some time ago, which is based on a well-known theorem on
functional determinants. The proper handling of zero modes and of
renormalization is discussed. The numerical results in particular show that
quantum corrections become smaller away from the thin-wall case. In the
thin-wall limit the numerical results are found to join into those obtained by
a gradient expansion.Comment: 31 pages, 7 figure
Immunohistochemical Demonstration of IgG in Reed-Sternberg and Other Cells in Hodgkin\u27s Disease
Increased synthesis of IgG in vitro has been demonstrated in spleens from patients with Hodgkin\u27s disease, either with or without invasion of the organ by tumor (1). Interest in this laboratory has centered recently on cytochemical localization of immunoglobulins by means of an immunoglobulin-peroxidase bridge procedure (2) and a satisfactory method has been developed for selectively visualizing immunocytes with this technique. 1 As a means of assessing the basis for increased IgG biosynthesis in spleens of Hodgkin patients, this immunostaining procedure has been applied to localization of IgG-producing cells in specimens with Hodgkin\u27s disease
Oral Health as a Risk Factor for Alzheimer Disease
In patients with Alzheimer’s disease pathophysiological changes of the brain that initiate the onset of Alzheimer’s disease include accumulation of amyloid-β plaques and phosphorylation of tau-tangles. A rather recently considered risk factor for the onset of Alzheimer’s disease is poor oral health. The aim of this systematic review of the literature was to assess the potential association(s) of oral health as a risk factor for the onset of Alzheimer’s disease. After a systematic search of Pubmed, Embase and Web of Science. A total of 1962 studies were assessed, of which 17 studies demonstrated possible associations between oral health diseases and Alzheimer’s disease. 4 theories could be distinguished that describe the possible links between oral health and the development or onset of Alzheimer’s disease; 1) role of pathogens, 2) role of inflammatory mediators, 3) role of APOE alleles and 4) role of Aβ peptide. The main common denominator of all the theories is the neuroinflammation due to poor oral health. Yet, there is insufficient evidence to prove a link due to the diversity of the designs used and the quality of the study design of the included studies. Therefore, further research is needed to find causal links between oral health and neuroinflammation that possibly can lead to the onset of Alzheimer’s disease with the future intention to prevent cognitive decline by better dental care.</p
The feruloyl esterase from Thermobacillus xylanilyticus shows broad specificity for processing pre-biotic feruloylated xylooligosaccharides at high temperatures
Oral Health as a Risk Factor for Alzheimer Disease
In patients with Alzheimer’s disease pathophysiological changes of the brain that initiate the onset of Alzheimer’s disease include accumulation of amyloid-β plaques and phosphorylation of tau-tangles. A rather recently considered risk factor for the onset of Alzheimer’s disease is poor oral health. The aim of this systematic review of the literature was to assess the potential association(s) of oral health as a risk factor for the onset of Alzheimer’s disease. After a systematic search of Pubmed, Embase and Web of Science. A total of 1962 studies were assessed, of which 17 studies demonstrated possible associations between oral health diseases and Alzheimer’s disease. 4 theories could be distinguished that describe the possible links between oral health and the development or onset of Alzheimer’s disease; 1) role of pathogens, 2) role of inflammatory mediators, 3) role of APOE alleles and 4) role of Aβ peptide. The main common denominator of all the theories is the neuroinflammation due to poor oral health. Yet, there is insufficient evidence to prove a link due to the diversity of the designs used and the quality of the study design of the included studies. Therefore, further research is needed to find causal links between oral health and neuroinflammation that possibly can lead to the onset of Alzheimer’s disease with the future intention to prevent cognitive decline by better dental care.</p
- …