A note on first passage probabilities of a L\'evy process reflected at a general barrier

In this paper we analyze a L\'evy process reflected at a general (possibly random) barrier. For this process we prove Central Limit Theorem for the first passage time. We also give the finite-time first passage probability asymptotics

Prenatal echocardiography – the impact on neonatal management

Congenital heart disease (CHD) results in neonatal morbidity and mortality. Prenatal diagnosis allows preparing an appropriate perinatal and postnatal care. Babies born in low-risk level sites with unexpected CHD may have poorer outcomes. The purpose of this study was to compare results of foetal echocardiography to postnatal findings and assess the impact of antenatal suspicions of CHD on postnatal management. Medical records of mother-infant pairs with CHD admitted to the Neonatal Intensive Care Unit (NICU) of the Medical University of Gdansk from 01.01. to 31.12.2013 were reviewed. We analysed if the defect was detected pre- or postnatally, and if the diagnosis was made by the obstetrician from low-risk level sites (level I) or from a tertiary care centre (level II sonography). The overall incidence of CHD was 68 (3,4%). Critical congenital heart defects (CCHD) were found in 24 neonates (1,2%), 21 were diagnosed prenatally, 3 were transferred from 1st level units. Correlation between prenatal diagnosis made at our centre and postnatal findings was achieved in 47,7%. Accuracy in all prenatal and postnatal findings for both I and II sonography levels was 35,2%. There were major differences in the disproportion of the great vessels and postnatal confirmation of coarctation of the aorta (CoAo) (7,1%). We obtained a high accuracy of prenatal and postnatal findings in detection of lesions such as Tetralogy of Fallot (ToF), transposition of the great arteries (TGA), DORV (double outlet right ventricle) and Critical Pulmonary Stenosis, which require an outflow tract view (92,9% of cases). Conclusions: We confirmed increasing diagnostic rates when the diagnostics is performed at a tertiary care centre. These results are in agreement with literature stating that prenatal detection of CoAo is still challenging. Despite the high rates of misdiagnosis, majority of infants benefited from prenatally diagnosed CCHD

Integument cell gelatinisation : the fate of the integumentary cells in Hieracium and Pilosella (Asteraceae)

Members of the genera Hieracium and Pilosella are model plants that are used to study the mechanisms of apomixis. In order to have a proper understanding of apomixis, knowledge about the relationship between the maternal tissue and the gametophyte is needed. In the genus Pilosella, previous authors have described the specific process of the "liquefaction" of the integument cells that surround the embryo sac. However, these observations were based on data only at the light microscopy level. The main aim of our paper was to investigate the changes in the integument cells at the ultrastructural level in Pilosella officinarum and Hieracium alpinum. We found that the integument peri-endothelial zone in both species consisted of mucilage cells. The mucilage was deposited as a thick layer between the plasma membrane and the cell wall. The mucilage pushed the protoplast to the centre of the cell, and cytoplasmic bridges connected the protoplast to the plasmodesmata through the mucilage layers. Moreover, an elongation of the plasmodesmata was observed in the mucilage cells. The protoplasts had an irregular shape and were finally degenerated. After the cell wall breakdown of the mucilage cells, lysigenous cavities that were filled with mucilage were formed

Synthesis of novel isothiazolopyridines and their in vitro evaluation against Mycobacterium and Propionibacterium acnes

AbstractIn this paper we describe synthesis, structures and some physicochemical properties of 20 isothiazolopyridines 8–13 substituted differently into an isothiazole ring as well as their in vitro antibacterial assays against Mycobacterium tuberculosis H37Rv, Mycobacterium fortuitum PCM 672 and Propionibacterium acnes PCM 2400. Compound 13a was found to be the most active derivative against M. tuberculosis H37Rv, demonstrating 100% growth inhibition of microorganisms in the primary screen (minimum inhibitory concentration [MIC] 6.25μg/mL). Nineteen of the prepared compounds were evaluated against M. fortuitum PCM 672 and P. acnes PCM 2400 and only compounds 9 and 12d exhibited excellent activity against individual strains of microorganisms with MIC90 <1μg/mL. The inhibitory action of the remaining isothiazolopyridines towards the tested strains of the microorganism was low, absent, or a non-linear correlation prohibited accurate determination of MIC values. Unexpectedly, seven of the remaining isothiazolopyridines tested against M. fortuitum and P. acnes stimulated growth of the microorganisms in the range 10–50% or even more (10b) under experimental conditions

Structural evolution of near-surface layers in NiTi alloy caused by an ion implantation

The results of X-ray diffraction studies on structural changes in the near-surface layers in the NiTi alloy caused by nitrogen-ion implantation with the energy E = 50 keV and the fluence D = 1018 cm-2 are presented. X-ray diffractometry, using the Philips diffractometer type X'Pert in the Bragg-Brentano geometry, was used to identify the phase composition of NiTi alloy. For layer by layer analysis of structural changes in the near-surface layers, the D8 Discover Bruker diffractometer with polycapilar beam optics was used. The ion-implanted NiTi alloy in the near-surface layer exhibits five phases: the dominating austenite phase, two martensitic phases and a small amount of the Ni4Ti3 and NTi phases. Along with the decreasing thickness of the near-surface layer investigated in material an increasing fraction of the Ni4Ti3 and NTi phases was observed. With the thickness of this layer about 340 nm, besides still existing the austenite, Ni4Ti3 and NTi phases, only one martensitic phase is present in the alloy. Further decrease of the thickness of the near-surface layer to about 170 nm leads to the increasing fraction of the Ni4Ti3 and NTi phases

Creation of wear-resistant near-surface-layers with inhomogeneous structure on NiTi alloy by ion implantation technology

In the present study we report the changes in the modified near-surface layer on NiTi shape memory alloy, caused by ion implantation as well as their influence on the structure and mechanical properties of this material. Experimental results of an inhomogeneous structure and tribological properties of implanted NiTi are discussed in this paper

Localization and nature of radiation donor defects in the arsenic implanted CdHgTe films grown by MBE

By profiling the electrical parameters of the arsenic implanted CdHgTe films, grown by molecular bea

Радиационные донорные дефекты в имплантированных As МЛЭ пленках Cd0.3Hg0.7Te: накопление и отжиг

В работе представлены результаты исследований процессов накопления радиационных донорных дефектов и их отжига в подвергнутых ионной имплантации (ИИ) мышьяком (As) гетероэпитаксиальных пленках CdxHg1-xTe (ГЭС КРТ) с составом активной области ха~0.3 и их сравнение с ранее проведенными аналогичными исследованиями для пленок с ха~0.22

Fluence dependence of nanosize defect layers in arsenic implanted HgCdTe epitaxial films studied with TEM/HRTEM

We report on the results of comparative study of fluence dependence of defect layers in molecular-beam epitaxy-grown epitaxial film of p-Hg1-х CdхTe (х=0.22) implanted with arsenic ions with 190 keV energy and fluence 1012, 1013, and 1014 cm-2