3,162 research outputs found
Volatomics in inflammatory bowel disease and irritable bowel syndrome
Volatile organic compounds (VOCs) are produced by the human metabolism, inflammation and gut microbiota and form the basis of innovative volatomics research. VOCs detected through breath and faecal analysis hence serve as attractive, non-invasive biomarkers for diagnosing and monitoring irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This review describes the clinical applicability of volatomics in discriminating between IBS, IBD and healthy volunteers with acceptable accuracy in breath (70%-100%) and faecal (58%-85%) samples. Promising compounds are propan-1-ol for diagnosing and monitoring of IBD patients, and 1-methyl-4-propan-2-ylcyclohexa-1,4-diene as biomarker for IBS diagnosis. However, these VOCs often seem to be related to inflammation and probably will need to be used in conjunction with other clinical evidence. Furthermore, three interventional studies underlined the potential of VOCs in predicting treatment outcome and patient follow-up. This shows great promise for future use of VOCs as non-invasive breath and faecal biomarkers in personalised medicine. However, properly designed studies that correlate VOCs to IBD/IBS pathogenesis, while taking microbial influences into account, are still key before clinical implementation can be expected. (C) 2020 The Author(s). Published by Elsevier B.V
Casimir-like effect on a granular pile
We investigate experimentally a Casimir-like effect in a three-dimensional pile of rice, which has a power-law avalanche size distribution. We observe the change in distance between two Plexiglas sheets placed on the pile parallel to each other and parallel to the mean avalanche flow direction, while rice grains are continuously and uniformly falling on top of the pile. The resulting avalanches are fluctuations, confinement of which is found to drive the two plates together. During 25-h experimental runs, for initial intersheet distances ranging from 20.0 to 90.0 mm we observe changes in the range from 6.0 mm to less than 1.0 mm. A similar distance dependence is obtained from a simple analytical model. © 2010 The American Physical Society
Worms and the treatment of inflammatory bowel disease: are molecules the answer?
The lack of exposure to helminth infections, as a result of improved living standards and medical conditions, may have contributed to the increased incidence of IBD in the developed world. Epidemiological, experimental, and clinical data sustain the idea that helminths could provide protection against IBD. Studies investigating the underlying mechanisms by which helminths might induce such protection have revealed the importance of regulatory pathways, for example, regulatory T-cells. Further investigation on how helminths influence both innate and adaptive immune reactions will shed more light on the complex pathways used by helminths to regulate the hosts immune system. Although therapy with living helminths appears to be effective in several immunological diseases, the disadvantages of a treatment based on living parasites are explicit. Therefore, the identification and characterization of helminth-derived immunomodulatory molecules that contribute to the protective effect could lead to new therapeutic approaches in IBD and other immune diseases
Convex optimization problem prototyping for image reconstruction in computed tomography with the Chambolle-Pock algorithm
The primal-dual optimization algorithm developed in Chambolle and Pock (CP),
2011 is applied to various convex optimization problems of interest in computed
tomography (CT) image reconstruction. This algorithm allows for rapid
prototyping of optimization problems for the purpose of designing iterative
image reconstruction algorithms for CT. The primal-dual algorithm is briefly
summarized in the article, and its potential for prototyping is demonstrated by
explicitly deriving CP algorithm instances for many optimization problems
relevant to CT. An example application modeling breast CT with low-intensity
X-ray illumination is presented.Comment: Resubmitted to Physics in Medicine and Biology. Text has been
modified according to referee comments, and typos in the equations have been
correcte
Interferon-alpha treatment rapidly clears Hepatitis e virus infection in humanized mice
Antiviral treatment options for chronic Hepatitis E Virus (HEV) infections are limited and immunological determinants of viral persistence remain largely unexplored. We studied the antiviral potency of pegylated interferon-α (pegIFNα) against HEV infections in humanized mice and modelled intrahepatic interferon stimulated gene (ISG) responses. Human gene expression levels in humanized mouse livers were analyzed by qPCR and Nanostring. Human CXCL10 was measured in mouse serum. HEV genotype 3 (gt3) infections were cleared from liver and feces within 8 pegIFNα doses in all mice and relapsed after a single pegIFNα injection in only half of treated animals. Rapid viral clearance by pegIFNα was confirmed in HEV gt1, but not in Hepatitis B Virus infected animals. No ISG induction was observed in untreated HEV gt3 and gt1 infected humanized livers compared to control chimeric mice, irrespective of the human hepatocyte donor, viral isolate or HEV infection duration. Human specific ISG transcript levels in mouse liver increased significantly after pegIFNα treatment and induced high circulating human CXCL10 in mouse serum. In conclusion, HEV gt1 and gt3 infections do not elicit innate intrahepatic immune responses and remain highly sensitive to pegIFNα in immunocompromised humanized mice
On the statistics of superlocalized states in self-affine disordered potentials
We investigate the statistics of eigenstates in a weak self-affine disordered
potential in one dimension, whose Gaussian fluctuations grow with distance with
a positive Hurst exponent . Typical eigenstates are superlocalized on
samples much larger than a well-defined crossover length, which diverges in the
weak-disorder regime. We present a parallel analytical investigation of the
statistics of these superlocalized states in the discrete and the continuum
formalisms. For the discrete tight-binding model, the effective localization
length decays logarithmically with the sample size, and the logarithm of the
transmission is marginally self-averaging. For the continuum Schr\"odinger
equation, the superlocalization phenomenon has more drastic effects. The
effective localization length decays as a power of the sample length, and the
logarithm of the transmission is fully non-self-averaging.Comment: 21 pages, 6 figure
Determination of free fatty acids in crude palm oil and refined-bleached-deodorized palm olein using Fourier transform infrared spectroscopy
A rapid direct Fourier transform infrared (FTIR) spectroscopic method using a 100 µ BaF2 transmission cell was developed for the determination of free fatty acid (FFA) in crude palm oil (CPO) and refined-bleached-deodorized (RBD) palm olein, covering an analytical range of 3.0–6.5% and 0.07–0.6% FFA, respectively. The samples were prepared by hydrolyzing oil with enzyme in an incubator. The optimal calibration models were constructed based on partial least squares (PLS) analysis using the FTIR carboxyl region (C=O) from 1722 to 1690 cm−1. The resulting PLS calibrations were linear over the range tested. The standard errors of calibration (SEC) obtained were 0.08% FFA for CPO with correlation coefficient (R2) of 0.992 and 0.01% FFA for RBD palm olein with R2 of 0.994. The standard errors of performance (SEP) were 0.04% FFA for CPO with R2 of 0.998 and 0.006% FFA for RBD palm olein with R2 of 0.998, respectively. In terms of reproducibility (r) and accuracy (a), both FTIR and chemical methods showed comparable results. Because of its simpler and more rapid analysis, which is less than 2 min per sample, as well as the minimum use of solvents and labor, FTIR has an advantage over the wet chemical method
Moyal star product approach to the Bohr-Sommerfeld approximation
The Bohr-Sommerfeld approximation to the eigenvalues of a one-dimensional
quantum Hamiltonian is derived through order (i.e., including the
first correction term beyond the usual result) by means of the Moyal star
product. The Hamiltonian need only have a Weyl transform (or symbol) that is a
power series in , starting with , with a generic fixed point in
phase space. The Hamiltonian is not restricted to the kinetic-plus-potential
form. The method involves transforming the Hamiltonian to a normal form, in
which it becomes a function of the harmonic oscillator Hamiltonian.
Diagrammatic and other techniques with potential applications to other normal
form problems are presented for manipulating higher order terms in the Moyal
series.Comment: 27 pages, no figure
MDA5 against enteric viruses through induction of interferon-like response partially via the JAK-STAT cascade
Enteric viruses including hepatitis E virus (HEV), human norovirus (HuNV), and rotavirus are causing global health issues. The host interferon (IFN) response constitutes the first-line defense against viral infections. Melanoma Differentiation-Associated protein 5 (MDA5) is an important cytoplasmic receptor sensing viral infection to trigger IFN production, and on the other hand it is also an IFN-stimulated gene (ISG). In this study, we investigated the effects and mode-of-action of MDA5 on the infection of enteric viruses. We found that MDA5 potently inhibited HEV, HuNV and rotavirus replication in multiple cell models. Overexpression of MDA5 induced transcription of important antiviral ISGs through IFN-like response, without triggering of functional IFN production. Interestingly, MDA5 activates the expression and phosphorylation of STAT1, which is a central component of the JAK-STAT cascade and a hallmark of antiviral IFN response. However, genetic silencing of STAT1 or pharmacological inhibition of the JAK-STAT cascade only partially attenuated the induction of ISG transcription and the antiviral function of MDA5. Thus, we have demonstrated that MDA5 effectively inhibits HEV, HuNV and rotavirus replication through provoking a non-canonical IFN-like response, which is partially dependent on JAK-STAT cascade
Determination of iodine value of palm oil based on triglyceride composition
The triglyceride (TG) composition of palm oil is normally determined by high-performance liquid chromatography (HPLC). The HPLC chromatograms indicated a good separation of most of the TG components in the oil. The TG can be classified based on either the TG groups, i.e., triunsaturated, monosaturated, disaturated, or trisaturated, or the number of double bonds, i.e., zero, one, two, three, or four double bonds. The more unsaturated the fatty acid, the greater the iodine value (IV). Therefore, it is hypothesized that the IV of an oil can be determined based upon the TG composition of the oil. Based on the TG groups, stepwise regression analysis showed that the areas of the disaturated, trisaturated, and triunsaturated TG peaks could predict the IV with a coefficient of determination (R2) of 0.990. The regression based on the number of double bonds yielded a good regression equation with R2=0.992. The important variables were the peak area of the fatty acids that contained zero, one, two, and three double bonds. This study concludes that the TG composition can be used to predict the IV of palm oil. The best prediction model is obtained by using the number of double bonds in the TG as the independent variable
- …