Search results for "-type"

Photometric and spectroscopic variability of the B5IIIe star HD 171219

2017

We analyzed the star HD 171219, one of the relatively bright Be stars observed in the seismo field of the CoRoT satellite, in order to determine its physical and pulsation characteristics. Classical Be stars are main-sequence objects of mainly B-type, whose spectra show, or have shown at some epoch, Balmer lines in emission and an infrared excess. Both characteristics are attributed to an equatorially concentrated circumstellar disk fed by non-periodic mass-loss episodes (outbursts). Be stars often show nonradial pulsation gravity modes and, as more recently discovered, stochastically excited oscillations. Applying the CLEANEST algorithm to the high-cadence and highly photometrically precis…

Hitting Time Distributions in Financial Markets

2006

We analyze the hitting time distributions of stock price returns in different time windows, characterized by different levels of noise present in the market. The study has been performed on two sets of data from US markets. The first one is composed by daily price of 1071 stocks trade for the 12-year period 1987-1998, the second one is composed by high frequency data for 100 stocks for the 4-year period 1995-1998. We compare the probability distribution obtained by our empirical analysis with those obtained from different models for stock market evolution. Specifically by focusing on the statistical properties of the hitting times to reach a barrier or a given threshold, we compare the prob…

A theoretical study of carbon-carbon bond formation by a Michael-type addition.

2012

A theoretical study of the Michael-type addition of 1,3-dicarbonyl compounds to α,β-unsaturated carbonyl compounds has been performed in the gas phase by means of the AM1 semiempirical method and by density functional theory (DFT) calculations within the B3LYP and M06-2X hybrid functionals. A molecular model has been selected to mimic the role of a base, which is traditionally used as a catalyst in Michael reactions, an acetate moiety to modulate its basicity, and point charges to imitate the stabilization of the negative charge developed in the substrate during the reaction when taking place in enzymatic environments. Results of the study of six different reactions obtained at the three di…

Fixed point results on metric-type spaces

2014

Abstract In this paper we obtain fixed point and common fixed point theorems for self-mappings defined on a metric-type space, an ordered metric-type space or a normal cone metric space. Moreover, some examples and an application to integral equations are given to illustrate the usability of the obtained results.

Vacancy Defects in Ga2O3: First-Principles Calculations of Electronic Structure

2021

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP08856540) as well as by the Latvian research council via the Latvian National Research Program under the topic ?High-Energy Physics and Accelerator Technologies?, Agreement No: VPP-IZM-CERN-2020/1-0002 for A.I. Popov. In addition, J. Purans is grateful to the ERAF project 1.1.1.1/20/A/057 while A. Platonenko was supported by Latvian Research Council No. LZP-2018/1-0214. The authors thank A. Lushchik and M. Lushchik for many useful discussions. The research was (partly) performed in the Institute of Solid State Physics, University of Latvia ISSP UL. ISSP UL as…

A critical evaluation of caplacizumab for the treatment of acquired thrombotic thrombocytopenic purpura

2020

Introduction: Acquired thrombotic thrombocytopenic purpura (aTTP) is a thrombotic microangiopathy caused by inhibitory autoantibodies against ADAMTS13 protein. Until recently, the combination of plasma exchange (PEX) and immunosuppression has been the standard front-line treatment in this disorder. However, aTTP-related mortality, refractoriness, and relapse are still a matter of concern. Areas covered: The better understanding of the pathophysiological mechanisms of aTTP has allowed substantial improvements in the diagnosis and treatment of this disease. Recently, the novel anti-VWF nanobody caplacizumab has been approved for acute episodes of aTTP. Caplacizumab is capable to block the adh…

Comparative analysis of fibrinolytic properties of Alteplase, Tenecteplase and Urokinase in an in vitro clot model of intracerebral haemorrhage.

2020

Abstract Objective Hematoma lysis with recombinant tissue plasminogen activator (rtPA) has emerged as an alternative therapy for spontaneous intracerebral and intraventricular haemorrhage (ICH and IVH). However, the MISTIE III and CLEAR III trial failed to show significant improvement of favourable outcomes. Besides experimental and clinical trials revealed neurotoxic effects of rtPA. The demand for optimization of fibrinolytic therapy persists. Herein, we used our recently devised clot model of ICH to systematically analyse fibrinolytic properties of rtPA, tenecteplase and urokinase. Methods In vitro clots of human blood (size: 25 ml and 50 ml; age: 1.5 tenecteplase, 24 tenecteplase and 48…

Urokinase activates macrophage PON2 gene transcription via the PI3K/ROS/MEK/SREBP-2 signalling cascade mediated by the PDGFR-β

2009

Aims We have recently shown that urokinase plasminogen activator (uPA) increases oxidative stress (OS), cholesterol biosynthesis, and paraoxonase 2 (PON2) expression in macrophages via binding to its receptor, the uPAR. Since PON2 is regulated by both OS and cholesterol content, we hypothesized that uPA elicits a cascade of signal transduction events shared by NADPH oxidase and cholesterol biosynthesis that culminates in PON2 gene expression. Here, we investigated the signalling pathway that leads to the expression of PON2 in macrophages in response to uPA. Methods and results The increase in macrophage PON2 mRNA levels in response to uPA was shown to depend on PON2 gene promoter activation…

Monolayer and multilayer field-effect transistors based on a high-mobility n-type polymer: effect of the polymeric texture on charge transport

2012

A comprehensive analysis of Universal Soil Loss Equation-based models at the Sparacia experimental area

2020

Improving Universal Soil Loss Equation (USLE)‐based models has large interest because simple and reliable analytical tools are necessary in the perspective of a sustainable land management. At first, in this paper, a general definition of the event rainfall‐ runoff erosivity factor for the USLE‐based models, REFₑ = (QR)ᵇ¹(EI₃₀)ᵇ², in which QR is the event runoff coefficient, EI₃₀ is the single‐storm erosion index, and b₁ and b₂ are coefficients, was introduced. The rainfall‐runoff erosivity factors of the USLE (b₁ = 0 and b₂ = 1), USLE‐M (b₁ = b₂ = 1), USLE‐MB (b₁ ≠ 1 and b₂ = 1), USLE‐MR (b₁ = 1 and b₂ ≠ 1), USLE‐MM (b₁ = b₂ ≠ 1), and USLE‐M2 (b₁ ≠ b₂ ≠ 1) can be defined using REFₑ. Then t…