Observational constraints on the origin of the elements. V. Non-LTE abundance ratios of [Ni/Fe] in Galactic stars and enrichment by sub-Chandrasekhar mass SNe

We constrain the role of different SN Ia channels in the chemical enrichment of the Galaxy by studying the abundances of nickel in Galactic stars. We investigate four different SN Ia sub-classes, including the classical single-degenerate near-Chandrasekhar mass SN Ia, the fainter SN Iax systems associated with He accretion from the companion, as well as two sub-Ch mass SN Ia channels. The latter include the double-detonation of a white dwarf accreting helium-rich matter and violent white dwarf mergers. NLTE models of Fe and Ni are used in the abundance analysis. In the GCE models, we include new delay time distributions arising from the different SN Ia channels, as well as recent yields for core-collapse supernovae and AGB stars. The data-model comparison is performed using a Markov chain Monte Carlo framework that allows us to explore the entire parameter space allowed by the diversity of explosion mechanisms and the Galactic SN Ia rate, taking into account the uncertainties of the observed data. We show that NLTE effects have a non-negligible impact on the observed [Ni/Fe] ratios in the Galactic stars. The NLTE corrections to Ni abundances are not large, but strictly positive, lifting the [Ni/Fe] ratios by ~+0.15 dex at [Fe/H] =-2. We find that that the distributions of [Ni/Fe] in LTE and in NLTE are very tight, with a scatter of < 0.1 dex at all metallicities, supporting earlier work. In LTE, most stars have scaled-solar Ni abundances, [Ni/Fe] = 0, with a slight tendency for sub-solar [Ni/Fe] ratios at lower [Fe/H]. In NLTE, however, we find a mild anti-correlation between [Ni/Fe] and metallicity, and a slightly elevated [Ni/Fe] ratios at [Fe/H] < -1.0. The NLTE data can be explained by the GCE models calculated with a substantial, ~ 75%, fraction of sub-Ch SN Ia.Comment: accepted for publication in Astronomy & Astrophysics, abridged version of the abstrac

Patients with IgA nephropathy exhibit high systemic PDGF-DD levels

Background. Platelet-derived growth factor (PDGF) is a central mediator of mesangioproliferative glomerulonephritis (GN). In experimental mesangioproliferative GN, PDGF-DD serum levels, unlike PDGF-BB, increased up to 1000-fold. Methods. We assessed disease activity in 72 patients with GN, established a novel PDGF-D ELISA and then determined their PDGF-DD levels. In parallel, we studied renal PDGF-DD mRNA expression by RT-PCR. Results. PDGF-DD serum levels in patients with IgA nephropathy (IgAN) were significantly higher (1.67 ± 0.45 ng/ml) and in patients with lupus nephritis significantly lower (0.66 ± 0.86 ng/ml) compared to healthy controls (1.17 ± 0.46 ng/ml), while patients with focal segmental glomerulosclerosis, membranous GN and ANCA-positive vasculitis did not differ from controls. The subgroup of IgAN patients with elevated PDGF-DD levels (27% of samples) did not differ in their clinical features from those with normal PDGF-DD levels. In IgAN patients with repetitive PDGF-DD determinations, most exhibited only minor fluctuations of serum levels over time. Intrarenal PDGF-DD mRNA expression did not differ between controls and patients, suggesting an extrarenal source of the elevated PDGF-DD in IgAN. Conclusions. Serum PDGF-DD levels were specifically elevated in patients with IgAN, in particular in those with early disease, i.e. preserved renal function. Our data support the rationale for anti-PDGF-DD therapy in mesangioproliferative G

Model of material and financial flows in the forest industry cluster of the Tomsk region

The main objective of the paper is the modeling of the timber industry complex in the Tomsk region from circular economy and sustainable development point of view. On the basis of the value chain process and the formation of threats along the whole chain nature (forest) - economy - society (consumer) the modeling of products and waste creation has been developed. The large amount of unused waste requires the development of a special regional forestry cluster model using circular economy approach in order to propose best solutions for recycling

Acceptance of technology-enhanced learning for a theoretical radiological science course: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Technology-enhanced learning (TEL) gives a view to improved education. However, there is a need to clarify how TEL can be used effectively. The study compared students' attitudes and opinions towards a traditional face-to-face course on theoretical radiological science and a TEL course where students could combine face-to-face lectures and e-learning modules at their best convenience.</p> <p>Methods</p> <p>42 third-year dental students were randomly assigned to the traditional face-to-face group and the TEL group. Both groups completed questionnaires before the beginning and after completion of the course on attitudes and opinions towards a traditional face-to-face lectures and technology-enhanced learning. After completion of the course both groups also filled in the validated German-language TRIL (Trierer Inventar zur Lehrevaluation) questionnaire for the evaluation of courses given at universities.</p> <p>Results</p> <p>Both groups had a positive attitude towards e-learning that did not change over time. The TEL group attended significantly less face-to-face lectures than the traditional group. However, both groups stated that face-to-face lectures were the basis for education in a theoretical radiological science course.</p> <p>The members of the TEL group rated e-mail reminders significantly more important when they filled in the questionnaire on attitudes and opinions towards a traditional face-to-face lectures and technology-enhanced learning for the second time after completion of the course.</p> <p>The members of the technology-enhanced learning group were significantly less confident in passing the exam compared to the members of the traditional group. However, examination results did not differ significantly for traditional and the TEL group.</p> <p>Conclusions</p> <p>It seems that technology-enhanced learning in a theoretical radiological science course has the potential to reduce the need for face-to-face lectures. At the same time examination results are not impaired. However, technology-enhanced learning cannot completely replace traditional face-to-face lectures, because students indicate that they consider traditional teaching as the basis of their education.</p

Отсылочные нормы таможенного права в таможенных кодексах ТС/EAЭC и EC: сравнительный анализ практики применения

Актуальность темы исследования обусловлена необходимостью универсального изучения отсылочных норм, так как это является одним из неотъемлемых элементов научного анализа правоприменительного и правотворческого процессов.В процессе исследования была рассмотрена структура ТК ТС и ТК ЕАЭС,были выделены основные изменения, изучен правотворческий и правоприменительный процесс использования отсылочного способа изложения элементов норм права, проанализирована динамика и характер использования отсылочных норм права в таможенных кодексах ТС, ЕАЭС и ЕС 2000-х - 2010-х годов, были определены перспективы развития отсылочных норм права в таможенном законодательстве государств-членов ЕАЭС.The relevance of the research topic is due to the need for universal study of reference rules, as this is one of the integral elements of the scientific analysis of law enforcement and law-making processes. During the study, the structure of the CC of the CU and CC of the EAEU was considered, the main changes were identified, the law-making and law enforcement process of using the reference method of presenting the elements of the law, analyzed the dynamics and nature of the use of reference rules of law in the Customs Codes of the CU, EAEU and the EU of the 2000s-2010s, the prospects for the development of reference rules of law in the customs legislation of the EAEU member states were determined

PDGF-C Induces Maturation of Blood Vessels in a Model of Glioblastoma and Attenuates the Response to Anti-VEGF Treatment

Recent clinical trials of VEGF inhibitors have shown promise in the treatment of recurrent glioblastomas (GBM). However, the survival benefit is usually short-lived as tumors escape anti-VEGF therapies. Here we tested the hypothesis that Platelet Derived Growth Factor-C (PDGF-C), an isoform of the PDGF family, affects GBM progression independent of VEGF pathway and hinders anti-VEGF therapy.We first showed that PDGF-C is present in human GBMs. Then, we overexpressed or downregulated PDGF-C in a human GBM cell line, U87MG, and grew them in cranial windows in nude mice to assess vessel structure and function using intravital microscopy. PDGF-C overexpressing tumors had smaller vessel diameters and lower vascular permeability compared to the parental or siRNA-transfected tumors. Furthermore, vessels in PDGF-C overexpressing tumors had more extensive coverage with NG2 positive perivascular cells and a thicker collagen IV basement membrane than the controls. Treatment with DC101, an anti-VEGFR-2 antibody, induced decreases in vessel density in the parental tumors, but had no effect on the PDGF-C overexpressing tumors.These results suggest that PDGF-C plays an important role in glioma vessel maturation and stabilization, and that it can attenuate the response to anti-VEGF therapy, potentially contributing to escape from vascular normalization