Nanocapsules containing salt hydrate phase change materials for thermal energy storage

Nanocapsules containing salt hydrate for latent heat storage were proven to be thermally and chemically stable over 100 cycles.</p

A Substantial Amount of Hidden Magnetic Energy in the Quiet Sun

Deciphering and understanding the small-scale magnetic activity of the quiet solar photosphere should help to solve many of the key problems of solar and stellar physics, such as the magnetic coupling to the outer atmosphere and the coronal heating. At present, we can see only ${\sim}1$ of the complex magnetism of the quiet Sun, which highlights the need to develop a reliable way to investigate the remaining 99%. Here we report three-dimensional radiative tranfer modelling of scattering polarization in atomic and molecular lines that indicates the presence of hidden, mixed-polarity fields on subresolution scales. Combining this modelling with recent observational data we find a ubiquitous tangled magnetic field with an average strength of ${\sim}130$ G, which is much stronger in the intergranular regions of solar surface convection than in the granular regions. So the average magnetic energy density in the quiet solar photosphere is at least two orders of magnitude greater than that derived from simplistic one-dimensional investigations, and sufficient to balance radiative energy losses from the solar chromosphere.Comment: 21 pages and 2 figures (letter published in Nature on July 15, 2004

The impact of non-LTE effects and granulation inhomogeneities on the derived iron and oxygen abundances in metal-poor halo stars

This paper presents the results of a detailed theoretical investigation of the impact of non-LTE effects and of granulation inhomogeneities on the derived iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our analysis is based on both the `classical' one-dimensional (1D) stellar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We find that the non-LTE effects on the iron abundance derived from Fe {\sc i} lines are very important, amounting to ${\sim}0.9$ dex and to ${\sim}0.6$ dex in the 3D and 1D cases, respectively. On the other hand, we find that non-LTE and 3D effects have to be taken into account for a reliable determination of the iron abundance from weak Fe {\sc ii} lines, because the significant overexcitation of their upper levels in the granular regions tend to produce emission features. As a result such Fe {\sc ii} lines are weaker than in LTE and the abundance correction amounts to ${\sim}0.4$ dex for the 3D case. We derive also the oxygen-to-iron abundance ratio in the metal-poor star HD140283 by using the O {\sc i} triplet at 7772--5 \AA and the forbidden [O {\sc i}] line at 6300 \AA. Interestingly, when both non-LTE and 3D effects are taken into account there still remains significant discrepancies in the iron abundances derived from Fe {\sc i} and Fe {\sc ii} lines, as well as in the oxygen abundances inferred from the O {\sc i} and [O {\sc i}] lines. We conclude that the metalicity of this type of metal-poor stars could be significantly larger than previously thought, which may have far-reaching implications in stellar astrophysics.Comment: The Astrophysical Journal (in press). (35 pages, 5 figures and 4 tables

EVALUATION OF HISTOLOGICAL PARAMETERS IN PATIENTS WITH CLINICAL REMISSION OF ULCERATIVE COLITIS

Goal of the study: to examine histological changes in the mucosa of patients with clinical remission of ulcerative colitis and compare these changes with endoscopic parameters. Methods: 25 patients with clinical remission of ulcerative colitis underwent fibrocolonoscopy with biopsy and histological assessment of disease activity on the Gebos scale. Due to limited number of observations, it was possible to identify comparable study and control groups only for two parameters: increased eosinophil count and increased density of infiltrate in the mucosa. Results of the study: erosions, cryptitis, hyperplasia of lymphoid structures and infiltration of the intestinal mucosa with neutrophilic leukocyte often observed in the presence of increased eosinophil count in the mucosa and/or increased density of the cellular infiltrate. Conclusion: increased eosinophil count and/or increased density of the cellular infiltrate in the mucosa often accompanied by other signs of lack of the mucosa healing. Confirmation of complete remission of the disease requires histological control for exclusion of the inflammation signs

An overview of early investigational drugs for the treatment of human papilloma virus infection and associated dysplasia

Introduction: High-risk HPV (HR-HPV) related invasive cervical cancer (ICC) causes >270,000 deaths per annum world-wide with over 85% of these occurring in low-resource countries. Ablative and excisional treatment modalities are restricted for use with high-grade pre-cancerous cervical disease with HPV infection and low-grade dysplasia mostly managed by a watch-and-wait policy.Areas Covered: Various pharmacological approaches have been investigated as non-destructive alternatives for the treatment of HR-HPV infection and associated dysplasia. These are discussed dealing with efficacy, ease-of-use (physician or self-applied), systemic or locally applied, side-effects, cost and risks. The main focus is the perceived impact on current clinical practice of a self-applied, effective and safe pharmacological anti-HPV treatment.Expert opinion: Current prophylactic HPV vaccines are expensive, HPV type restricted and have little effect in already infected women. Therapeutic vaccines are under development but are also HPV type-restricted. At present, the developed nations use national cytology screening and surgical procedures to treat only women identified with HPV-related high-grade dysplastic disease. However, since HPV testing is rapidly replacing cytology as the test-of-choice, a suitable topically-applied and low-cost antiviral treatment could be an ideal solution for treatment of HPV infection per se with test-of-cure carried out by repeat HPV testing. Cytology would only then be necessary for women who remained HPV positive. Although of significant benefit in the developed countries, combining such a treatment with self-sampled HPV testing could revolutionise the management of this disease in the developing world which lack both the infrastructure and resources to establish national cytology screening programs

Analysis of stellar spectra with 3D and NLTE models

Models of radiation transport in stellar atmospheres are the hinge of modern astrophysics. Our knowledge of stars, stellar populations, and galaxies is only as good as the theoretical models, which are used for the interpretation of their observed spectra, photometric magnitudes, and spectral energy distributions. I describe recent advances in the field of stellar atmosphere modelling for late-type stars. Various aspects of radiation transport with 1D hydrostatic, LTE, NLTE, and 3D radiative-hydrodynamical models are briefly reviewed.Comment: 21 pages, accepted for publication as a chapter in "Determination of Atmospheric Parameters of B, A, F and G Type Stars", Springer (2014), eds. E. Niemczura, B. Smalley, W. Pyc

Sulphur and zinc abundances in Galactic stars and damped Lyman-alpha systems

High resolution spectra of 34 halo population dwarf and subgiant stars have been obtained with VLT/UVES and used to derive sulphur abundances from the 8694.0, 8694.6 A and 9212.9, 9237.5 A SI lines. In addition, iron abundances have been determined from 19 FeII lines and zinc abundances from the 4722.2, 4810.5 ZnI lines. The abundances are based on a classical 1D, LTE model atmosphere analysis, but effects of 3D hydrodynamical modelling on the [S/Fe], [Zn/Fe] and [S/Zn] ratios are shown to be small. We find that most halo stars with metallicities in the range -3.2 < [Fe/H] < -0.8 have a near-constant [S/Fe] = +0.3; a least square fit to [S/Fe] vs. {Fe/H] shows a slope of only -0.04 +/- 0.01. Among halo stars with -1.2 < [Fe/H] < -0.8 the majority have [S/Fe] ~ +0.3, but two stars (previously shown to have low [alpha/Fe] ratios) have [S/Fe] ~ 0. For disk stars with [Fe/H] > -1, [S/Fe] decreases with increasing [Fe/H]. Hence, sulphur behaves like other typical alpha-capture elements, Mg, Si and Ca. Zinc, on the other hand, traces iron over three orders of magnitude in [Fe/H], although there is some evidence for a small systematic Zn overabundance ([Zn/Fe] ~ +0.1) among metal-poor disk stars and for halo stars with [Fe/H] < -2.0. Recent measurements of S and Zn in ten damped Ly-alpha systems (DLAs) with redshifts between 1.9 and 3.4 and zinc abundances in the range -2.1 < [Zn/H] < -0.15 show an offset relative to the [S/Zn] - [Zn/H] relation in Galactic stars. Possible reasons for this offset are discussed, including low and intermittent star formation rates in DLAs.Comment: Accepted for publication in A&A. 16pages; 9 figure

Permitted Oxygen Abundances and the Temperature Scale of Metal-Poor Turn-Off Stars

We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and NLTE, employing effective temperatures obtained with the new infrared flux method (IRFM) temperature scale by Ramirez & Melendez, and surface gravities from Hipparcos parallaxes and theoretical isochrones. A new list of accurate transition probabilities for FeII lines, tied to the absolute scale defined by laboratory measurements, has been used. We find a plateau in the oxygen-to-iron ratio over more than two orders of magnitude in iron abundance (-3.2 < [Fe/H] < -0.7), with a mean [O/Fe] = 0.5 dex (sigma = 0.1 dex), independent of metallicity, temperature and surface gravity. According to the new IRFM Teff scale, the temperatures of turn-off halo stars strongly depend on metallicity, a result that is in excellent qualitative and quantitative agreement with stellar evolution calculations, which predict that the Teff of the turn-off at [Fe/H] = -3 is about 600-700 K higher than that at [Fe/H] = -1.Comment: In press, Ap

Oxygen in the Very Early Galaxy

Oxygen abundances in a sample of ultra-metal-poor subdwarfs have been derived from measurements of the oxygen triplet at 7771--5 A and OH lines in the near UV performed in high-resolution and high signal-to-noise spectra obtained with WHT/UES, KeckI/HIRES, and VLT/UVES. Our Fe abundances were derived in LTE and then corrected for NLTE effects following Thevenin and Idiart (1999). The new oxygen abundances confirm previous findings for a progressive linear rise in the oxygen-to-iron ratio with a slope -0.33+-0.02 from solar metallicity to [Fe/H] -3. A slightly higher slope would be obtained if the Fe NLTE corrections were not considered. Below [Fe/H]= -2.5 our stars show [O/Fe] ratios as high as ~ 1.17 (G64-12), which can be interpreted as evidence for oxygen overproduction in the very early epoch of the formation of the halo, possibly associated with supernova events with very massive progenitor stars. We show that the arguments against this linear trend given by Fulbright and Kraft (1999), based on the LTE Fe analysis of two metal-poor stars cannot be sustained when an NLTE analysis is performed. Using 1-D models our analysis of three oxygen indicators available for BD +23 3130 gives consistent abundances within 0.16 dex and average [O/Fe] ratio of 0.91.Comment: 45 pages, 11 figures, accepted for publication in The Astrophysical Journa

Раннее назначение генно-инженерных биологических препаратов при иммуновоспалительных заболеваниях: возможности и перспективы. Позиция экспертов

Psoriasis (Ps), psoriatic arthritis (PsA), and inflammatory bowel diseases (IBDs) are characterized by a progressive course and frequently lead to disability; therefore, their early diagnosis with the assessment of a clinical phenotype and unfavorable prognostic factors and the timely initiation of therapy are important tasks. The paper provides the experts agreed opinion on the definition of the early stage of Ps, PsA, and IBDs, the goals of therapy and main unfavorable prognostic factors for the course of these diseases and gives the rationale for the early use of biological agents in patients with immune-mediated inflammatory diseases.Псориаз (Пс), псориатический артрит (ПсА) и воспалительные заболевания кишечника (ВЗК) характеризуются прогрессирующим течением и нередко приводят к инвалидизации, поэтому важными задачами являются их ранняя диагностика с оценкой клинического фенотипа и факторов неблагоприятного прогноза и своевременное начало терапии. В статье приводятся согласованная позиция экспертов по определению ранней стадии Пс, ПсА и ВЗК, цели терапии и основные факторы неблагоприятного прогноза течения этих заболеваний, представлено обоснование раннего применения генно-инженерных биологических препаратов у пациентов с иммуновоспалительной патологией