Riesz potentials and nonlinear parabolic equations

The spatial gradient of solutions to nonlinear degenerate parabolic equations can be pointwise estimated by the caloric Riesz potential of the right hand side datum, exactly as in the case of the heat equation. Heat kernels type estimates persist in the nonlinear cas

Local and global behaviour of nonlinear equations with natural growth terms

This paper concerns a study of the pointwise behaviour of positive solutions to certain quasi-linear elliptic equations with natural growth terms, under minimal regularity assumptions on the underlying coefficients. Our primary results consist of optimal pointwise estimates for positive solutions of such equations in terms of two local Wolff's potentials.Comment: In memory of Professor Nigel Kalto

Regularity estimates for the solution and the free boundary to the obstacle problem for the fractional Laplacian

We use a characterization of the fractional Laplacian as a Dirichlet to Neumann operator for an appropriate differential equation to study its obstacle problem. We write an equivalent characterization as a thin obstacle problem. In this way we are able to apply local type arguments to obtain sharp regularity estimates for the solution and study the regularity of the free boundary

Si nanoparticle interfaces in Si/SiO2 solar cell materials

Novel solar cell materials consisting of Si nanoparticles embedded in SiO2 layers have been studied using positron annihilation spectroscopy in Doppler broadening mode and photoluminescence. Two positron-trapping interface states are observed after high temperature annealing at 1100 °C. One of the states is attributed to the (SiO2/Si bulk) interface and the other to the interface between the Si nanoparticles and SiO2. A small reduction in positron trapping into these states is observed after annealing the samples in N2 atmosphere with 5% H2. Enhanced photoluminescence is also observed from the samples following this annealing step.Peer reviewe

Consistency and reliability of smoking-related variables: longitudinal study design in asthma and COPD

Introduction: Smoking has a significant impact on the development and progression of asthma and chronic obstructive pulmonary disease (COPD). Self-reported questionnaires and structured interviews are usually the only way to study patients' smoking history. In this study, we aim to examine the consistency of the responses of asthma and COPD patients to repeated standardised questions on their smoking habits over the period of 10 years. Methods: The study population consisted of 1329 asthma and 959 COPD patients, who enrolled in the study during years 2005-2007. A follow-up questionnaire was mailed to the participants 1, 2, 4, 6, 8, and 10 years after the recruitment. Results: Among the participants who returned three or more questionnaires (N = 1454), 78.5 % of the patients reported unchanged smoking status (never smoker, ex-smoker or current smoker) across the time. In 4.5% of the answers, the reported smoking statuses were considered unreliable/conflicting (first never smoker and, later, smoker or ex-smoker). The remainder of the patients changed their status from current smoker to ex-smoker and vice versa at least once, most likely due to struggling with quitting. COPD patients were more frequently heavy ex- or current smokers compared to the asthma group. The intraclass coefficient correlations between self-reported starting (0.85) and stopping (0.94) years as well as the consumption of cigarettes (0.74) over time showed good reliability among both asthma and COPD patients. Conclusion: Self-reported smoking data among elderly asthma and COPD patients over a 10-year follow-up is reliable. Pack years can be considered a rough estimate for their comprehensive consumption of tobacco products over time. We also observed that the questionnaire we used was not designed for dynamic changes in smoking which are rather common among heavy smokers especially when the follow-up time is several years, as in our study

MTBVAC-Based TB-HIV Vaccine Is Safe, Elicits HIV-T Cell Responses, and Protects against Mycobacterium tuberculosis in Mice

The tuberculosis (TB) vaccine MTBVAC is the only live-attenuated Mycobacterium tuberculosis (Mtb)-based vaccine in clinical development, and it confers superior protection in different animal models compared to the current vaccine, BCG (Mycobacterium bovis bacillus Calmette-Guérin). With the aim of using MTBVAC as a vector for a dual TB-HIV vaccine, we constructed the recombinant MTBVAC.HIVA 2auxo strain. First, we generated a lysine auxotroph of MTBVAC (MTBVAC¿lys) by deleting the lysA gene. Then the auxotrophic MTBVAC¿lys was transformed with the E. coli-mycobacterial vector p2auxo.HIVA, harboring the lysA-complementing gene and the HIV-1 clade A immunogen HIVA. This TB-HIV vaccine conferred similar efficacy to the parental strain MTBVAC against Mtb challenge in mice. MTBVAC.HIVA 2auxo was safer than BCG and MTBVAC in severe combined immunodeficiency (SCID) mice, and it was shown to be maintained up to 42 bacterial generations in vitro and up to 100 days after inoculation in vivo. The MTBVAC.HIVA 2auxo vaccine, boosted with modified vaccinia virus Ankara (MVA).HIVA, induced HIV-1 and Mtb-specific interferon-¿-producing T cell responses and polyfunctional HIV-1-specific CD8+ T cells producing interferon-¿ (IFN-¿), tumor necrosis factor alpha (TNF-a), and CD107a in BALB/c mice. Here we describe new tools to develop combined vaccines against TB and HIV with the potential of expansion for other infectious diseases

Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species

A three-feature prediction model for metastasis-free survival after surgery of localized clear cell renal cell carcinoma

After surgery of localized renal cell carcinoma, over 20% of the patients will develop distant metastases. Our aim was to develop an easy-to-use prognostic model for predicting metastasis-free survival after radical or partial nephrectomy of localized clear cell RCC. Model training was performed on 196 patients. Right-censored metastasis-free survival was analysed using LASSO-regularized Cox regression, which identified three key prediction features. The model was validated in an external cohort of 714 patients. 55 (28%) and 134 (19%) patients developed distant metastases during the median postoperative follow-up of 6.3 years (interquartile range 3.4-8.6) and 5.4 years (4.0-7.6) in the training and validation cohort, respectively. Patients were stratified into clinically meaningful risk categories using only three features: tumor size, tumor grade and microvascular invasion, and a representative nomogram and a visual prediction surface were constructed using these features in Cox proportional hazards model. Concordance indices in the training and validation cohorts were 0.755 +/- 0.029 and 0.836 +/- 0.015 for our novel model, which were comparable to the C-indices of the original Leibovich prediction model (0.734 +/- 0.035 and 0.848 +/- 0.017, respectively). Thus, the presented model retains high accuracy while requiring only three features that are routinely collected and widely available.Peer reviewe

Riesz and Wolff potentials and elliptic equations in variable exponent weak Lebesgue spaces

We prove optimal integrability results for solutions of the p(x)-Laplace equation in the scale of (weak) Lebesgue spaces. To obtain this, we show that variable exponent Riesz and Wolff potentials map L1 to variable exponent weak Lebesgue spaces

Independent and cumulative coeliac disease-susceptibility loci are associated with distinct disease phenotypes

The phenotype of coeliac disease varies considerably for incompletely understood reasons. We investigated whether established coeliac disease susceptibility variants (SNPs) are individually or cumulatively associated with distinct phenotypes. We also tested whether a polygenic risk score (PRS) based on genome-wide associated (GWA) data could explain the phenotypic variation. The phenotypic association of 39 non-HLA coeliac disease SNPs was tested in 625 thoroughly phenotyped coeliac disease patients and 1817 controls. To assess their cumulative effects a weighted genetic risk score (wGRS39) was built, and stratified by tertiles. In our PRS model in cases, we took the summary statistics from the largest GWA study in coeliac disease and tested their association at eight P value thresholds (P-T) with phenotypes. Altogether ten SNPs were associated with distinct phenotypes after correction for multiple testing (P-EMP2 1.62 for having coeliac disease-related symptoms during childhood, a more severe small bowel mucosal damage, malabsorption and anaemia. PRS was associated only with dermatitis herpetiformis (P-T = 0.2, P-EMP2 = 0.02). Independent coeliac disease-susceptibility loci are associated with distinct phenotypes, suggesting that genetic factors play a role in determining the disease presentation. Moreover, the increased number of coeliac disease susceptibility SNPs might predispose to a more severe disease course.Peer reviewe