Supercritical fluid extraction-capillary gas chromatography: on-line coupling with a programmed temperature vaporizer

A simple and versatile system is described for the on-line coupling of SFE to capillary GC. The interfacing consists of a programmed temperature vaporizer (PTV) injector. With this injector it is possible to combine solute trapping, elimination of a high flow of extraction fluid, and quantitative transfer of solutes to the seperation column. The problems caused by impurities in the extraction fluid in on-line SFE-GC are discussed. Simple methods are described for the purification of commercially available carbon dioxide. The trapping efficiency of the PTV injector is studied. Applications of the SFE-PTV-GC system are given for the analysis of polymer anti-degradants, polar compounds, and samples with environmental relevance

Corrigendum: The quest for EEG power band correlation with ICA derived fMRI resting state networks

Contains fulltext : 136233.pdf (publisher's version ) (Open Access)[This corrects the article on p. 315 in vol. 7, PMID: 23805098.].2 p

Novel criticality in a model with absorbing states

We study a one-dimensional model which undergoes a transition between an active and an absorbing phase. Monte Carlo simulations supported by some additional arguments prompted as to predict the exact location of the critical point and critical exponents in this model. The exponents $\delta=0.5$ and $z=2$ follows from random-walk-type arguments. The exponents $\beta = \nu_{\perp}$ are found to be non-universal and encoded in the singular part of reactivation probability, as recently discussed by H. Hinrichsen (cond-mat/0008179). A related model with quenched randomness is also studied.Comment: 5 pages, 5 figures, generalized version with the continuously changing exponent bet

Scale-invariant segmentation of dynamic contrast-enhanced perfusion MR-images with inherent scale selection

Selection of the best set of scales is problematic when developing signaldriven approaches for pixel-based image segmentation. Often, different possibly conflicting criteria need to be fulfilled in order to obtain the best tradeoff between uncertainty (variance) and location accuracy. The optimal set of scales depends on several factors: the noise level present in the image material, the prior distribution of the different types of segments, the class-conditional distributions associated with each type of segment as well as the actual size of the (connected) segments. We analyse, theoretically and through experiments, the possibility of using the overall and class-conditional error rates as criteria for selecting the optimal sampling of the linear and morphological scale spaces. It is shown that the overall error rate is optimised by taking the prior class distribution in the image material into account. However, a uniform (ignorant) prior distribution ensures constant class-conditional error rates. Consequently, we advocate for a uniform prior class distribution when an uncommitted, scaleinvariant segmentation approach is desired. Experiments with a neural net classifier developed for segmentation of dynamic MR images, acquired with a paramagnetic tracer, support the theoretical results. Furthermore, the experiments show that the addition of spatial features to the classifier, extracted from the linear or morphological scale spaces, improves the segmentation result compared to a signal-driven approach based solely on the dynamic MR signal. The segmentation results obtained from the two types of features are compared using two novel quality measures that characterise spatial properties of labelled images

Quantum theta functions and Gabor frames for modulation spaces

Representations of the celebrated Heisenberg commutation relations in quantum mechanics and their exponentiated versions form the starting point for a number of basic constructions, both in mathematics and mathematical physics (geometric quantization, quantum tori, classical and quantum theta functions) and signal analysis (Gabor analysis). In this paper we try to bridge the two communities, represented by the two co--authors: that of noncommutative geometry and that of signal analysis. After providing a brief comparative dictionary of the two languages, we will show e.g. that the Janssen representation of Gabor frames with generalized Gaussians as Gabor atoms yields in a natural way quantum theta functions, and that the Rieffel scalar product and associativity relations underlie both the functional equations for quantum thetas and the Fundamental Identity of Gabor analysis.Comment: 38 pages, typos corrected, MSC class change

Short mucin 6 alleles are associated with H pylori infection

Contains fulltext : 49314.pdf (publisher's version ) (Open Access)AIM: To investigate the relationship between mucin 6 (MUC6) VNTR length and H pylori infection. METHODS: Blood samples were collected from patients visiting the Can Tho General Hospital for upper gastrointestinal endoscopy. DNA was isolated from whole blood, the repeated section was cut out using a restriction enzyme (Pvu II) and the length of the allele fragments was determined by Southern blotting. H pylori infection was diagnosed by (14)C urea breath test. For analysis, MUC6 allele fragment length was dichotomized as being either long (> 13.5 kbp) or short (< or = 13.5 kbp) and patients were classified according to genotype [long-long (LL), long-short (LS), short-short (SS)]. RESULTS: 160 patients were studied (mean age 43 years, 36% were males, 58% H pylori positive). MUC6 Pvu II-restricted allele fragment lengths ranged from 7 to 19 kbp. Of the patients with the LL, LS, SS MUC6 genotype, 43% (24/56), 57% (25/58) and 76% (11/46) were infected with H pylori, respectively (P = 0.003). CONCLUSION: Short MUC6 alleles are associated with H pylori infection

Negative Regulation of Hepatitis C Virus Specific Immunity Is Highly Heterogeneous and Modulated by Pegylated Interferon-Alpha/Ribavirin Therapy

Specific inhibitory mechanisms suppress the T-cell response against the hepatitis C virus (HCV) in chronically infected patients. However, the relative importance of suppression by IL-10, TGF-β and regulatory T-cells and the impact of pegylated interferon-alpha and ribavirin (PegIFN-α/ribavirin) therapy on these inhibitory mechanisms are still unclear. We revealed that coregulation of the HCV-specific T-cell responses in blood of 43 chronic HCV patients showed a highly heterogeneous pattern before, during and after PegIFN-α/ribavirin. Prior to treatment, IL-10 mediated suppression of HCV-specific IFN-γ production in therapy-naive chronic HCV patients was associated with higher HCV-RNA loads, which suggests that protective antiviral immunity is controlled by IL-10. In addition, as a consequence of PegIFN-α/ribavirin therapy, negative regulation of especially HCV-specific IFN-γ production by TGF-β and IL-10 changed dramatically. Our findings emphasize the importance of negative regulation for the dysfunctional HCV-specific immunity, which should be considered in the design of future immunomodulatory therapies

Gunstige referentiewaarden voor oppervlakte en verspreidingsgebied van Natura 2000-habitattypen in Nederland

Dit rapport geeft een overzicht van de gunstige referentiewaarden van area (oppervlakte in km2) en range (oppervlakte verspreidingsgebied incl. opvulling in 10 x 10 km-hokken) voor alle 52 habitattypen in Nederland. Deze FRA (Favourable Reference Area) en FRR (Favourable Reference Range) zijn nodig om de staat van instandhouding van habitattypen volgens artikel 17 van de Habitatrichtlijn vast te stellen. Bijna 25% van de habitattypen vereist uitbreiding van verspreidingsgebied voor een gunstige staat van instandhouding. Ruim 20% van de habitattypen vereisen zowel een uitbreiding van oppervlakte als van verspreidingsgebied voor een gunstige staat van instandhouding. Daarnaast wordt aangegeven hoe de gunstige referentiewaarden behouden of bereikt kunnen worden en wat de mogelijke invloed van klimaatverandering is. Om de trend van area te beoordelen, zijn in bijlagen schattingen gemaakt van historische oppervlakten van habitattypen rond 1950 voor heide-, stuifzand-, hoogveen- en graslandtypen

A Retrospective Analysis and Comparison of the STAM and STAMCO Classification and EAONO/JOS Cholesteatoma Staging System in Predicting Surgical Treatment Outcomes of Middle Ear Cholesteatoma

OBJECTIVE: To evaluate and compare the STAM classification, STAMCO classification and the EAONO/JOS staging system as predictors for cholesteatoma recidivism and postoperative hearing, using a large patient cohort in our tertiary referral center. METHOD: Two hundred thirty-one patients who underwent surgery for primary cholesteatoma between 2003 and December 2012 were included and retrospectively classified and staged according to the STAM classification, STAMCO classification, and EAONO/JOS staging system. Data on cholesteatoma recidivism rates and postoperative hearing were collected. The predictive value of the three instruments for recurrent and residual cholesteatoma was compared by using receiver operating characteristic curves. RESULTS: For predicting recurrent cholesteatoma, the STAMCO classification was significantly superior compared to the other two instruments. For predicting residual cholesteatoma, the STAMCO classification was superior to the EANO/JOS Staging system. The postoperative hearing shows a significant increase in ABG with increasing extension of cholesteatoma in the CWU group and a significant decrease in AC threshold level with increasing stage and a significant increase in AC with increasing ossicular chain status in the CWD group. CONCLUSION: Based on our study, the STAMCO classification represents the best available predictor for recurrent cholesteatoma and holds most promise for predicting residual cholesteatoma. Extension of cholesteatoma seems to be linked to postoperative hearing and thus the classifications and staging systems may be able to predict postoperative hearing. More studies are needed to assess the validation of these classifications

Exploring the impact of chronic obstructive pulmonary disease (COPD) on diabetes control in diabetes patients: a prospective observational study in general practice

Background:Little is known about the association between COPD and diabetes control parameters.Aims:To explore the association between comorbid COPD and longitudinal glycaemic control (HbA 1C) and systolic blood pressure (SBP) in a primary care cohort of diabetes patients.Methods:This is a prospective cohort study of type 2 diabetes patients in the Netherlands. In a mixed model analysis, we tested differences in the 5-year longitudinal development of HbA 1C and SBP according to COPD comorbidity (present/absent). We corrected for relevant covariates. In subgroup effect analyses, we tested whether potential differences between diabetes patients with/without COPD were modified by age, sex, socio-economic status (SES) and body mass index (BMI).Results:We analysed 610 diabetes patients. A total of 63 patients (10.3%) had comorbid COPD. The presence of COPD was not significantly associated with the longitudinal development of HbA 1C (P=0.54) or SBP (P=0.33), but subgroup effect analyses showed significant effect modification by SES (P<0.01) and BMI (P=0.03) on SBP. Diabetes patients without COPD had a flat SBP trend over time, with higher values in patients with a high BMI. For diabetes patients with COPD, SBP gradually increased over time in the middle-And high-SES groups, and it decreased over time in those in the low-SES group.Conclusions:The longitudinal development of HbA 1C was not significantly associated with comorbid COPD in diabetes patients. The course of SBP in diabetes patients with COPD is significantly associated with SES (not BMI) in contrast to those without COPD. Comorbid COPD was associated with longitudinal diabetes control parameters, but it has complex interactions with other patient characteristics. Further research is needed