Prenatal diagnosis of urinary track defects

Introduction Congenital malformations are the main cause of miscarriage, perinatal mortality and disability among children. According to Polish Registry of Congenital Malformations for 2005-2006 congenital disorders affect 2.0-4.0% of newborns. Heart defects, musculoskeletal abnormalities and urinary track defects are the most common. Purpose The article aims to shortly describe characteristic ultrasound findings concerning certain urinary tract defects. Brief description Renal abnormalities result from complexity of kidneys embriogenesis. Obligatory ultrasound screenings during pregnancy enable early prenatal diagnosis of urinary track defects and it is helpful for planning postnatal or prenatal treatment. Oligohydramos is characteristic for urinary tract congenital disorders. Lack of renal parenchyma, increased echogenicity of renal parenchyma, difficulties in bladder visualisation, cysts within kidneys, hydronephrosis always indicate abnormalities concerning urinary track. Visualisation of urinary track defect obligate further screening for accompanying abnormalities. Sequence of defects, plural abnormalities are indications for genetic evaluation in referral medical centers. Postnatal treatment of congenial urinary track disorders include watchful observation, early surgical treatment or palliative care. The prognosis depends on the type of defect and accompanied anomalies. Summary/conclusion Urinary track defects in prenatal period are very common. Every child suspected for urinary track defect requires detailed evaluation in referral medical center including echocardiography and assessment of karyotype

Langmuir monolayer characteristics of erucylphosphocholine : a novel anti-tumor drug

Erucylphosphocholine, an alkylphosphocholine anticancer drug, was employed for Langmuir monolayer characterization and liquid crystalline studies. Differential scanning calorimetry measurements together with texture observation with polarizing microscope revealed the presence of nematic phase. Film forming properties of erucylphosphocholine at the air/water interface were thoroughly investigated by means of surface pressure–area ( º –A) and electric surface potential–area ( ¢ V – A ) isotherms. The influence of such factors as subphase temper- ature, ionic strength, speed of compression, number of molecules spread at the surface on the characteristics of the º – A isotherms was investigated. Erucylphosphocholine was found to form very stable Langmuir monolayers, which are almost not influenced by experimental conditions. The liquid character of its monolayers was confirmed with both compressibility modulus values and homogeneous Brewster angle microscopy images

Ferroelectric liquid crystal for use in a new generation of LCDs

The key to improvements in liquid crystalline displays lies in the continuous synthesis and studies of new kinds of liquid crystalline substances. Among them, ferroelectric compounds are the subject of much attention, due to the potential progresses in switching time, colour depth, and other qualities of liquid crystal displays. In this paper we describe the research of the physical properties of 4-(2-methylbutoxy)phenyl 4-(octyloxy)-benzoate for purposes of its potential application in liquid crystal displays

Electro-optic effect of laser photobleaching on viscoelastic properties of chiral liquid crystals

Viscoelastic properties are one of the most fundamental properties of chiral liquid crystals. In general, their determination is not a straightforward task. The main problem is the multitude of physical parameters needed to determine the value of the elasticity and viscosity constants. It is also necessary to consider the character of a respective phase. This problem is particularly important in the case of chiral phases such as ferroelectric and antiferroelectric phases or in the blue phases. There are several experimental methods to measure viscosity and elasticity constants in chiral phases. These methods use various phenomena to detect deformation, e.g., light transmission, polarization current, light modulation, dielectric constant and helix deformation or helix unwinding. Commonly, an external electric field is used to induce deformation, the homogeneity of which inside the cell is essential. This study is focused on the analysis of the effect of laser photobleaching on the electro-optic properties of the antiferroelectric liquid crystal and on the homogeneity of the electric field. The results obtained by confocal microscopy as a function of the cell depth are presented. The influence of the stabilization procedure of the isolated region performed by controlled laser photobleaching on the electro-optic properties has been studied. The observation was conducted using a polarizing microscope, and numerical analysis of two-dimensional colored textures was performed. The obtained results suggest that laser photobleaching can produce an anchoring effect, which has a positive effect on the electro-optic properties of antiferroelectric liquid crystal

Comparison of the dielectric properties of Ecoflex® with L,D-poly(lactic acid) or polycaprolactone in the presence of SWCN or 5CB

The main goal of this paper was to study the dielectric properties of hybrid binary and ternary composites based on biodegradable polymer Ecoflex®, single walled carbon nanotubes (SWCN), and liquid crystalline 4′-pentyl-4-biphenylcarbonitrile (5CB) compound. The obtained results were compared with other created analogically to Ecoflex®, hybrid layers based on biodegradable polymers such as L,D-polylactide (L,D-PLA) and polycaprolactone (PCL). Frequency domain dielectric spectroscopy (FDDS) results were analyzed taking into consideration the amount of SWCN, frequency, and temperature. For pure Ecoflex®, two relaxation processes (α and β) were identified. It was shown that the SWCN admixture (in the weight ratio 10:0.01) did not change the properties of the Ecoflex® layer, while in the case of PCL and L,D-PLA, the layers became conductive. The dielectric constant increased with an increase in the content of SWCN in the Ecoflex® matrix and the conductive behavior was not visible, even for the greatest concentration (10:0.06 weight ratio). In the case of the Ecoflex® polymer matrix, the conduction relaxation process at a frequency ca. several kilohertz appeared and became stronger with an increase in the SWCN admixture in the matrix. Addition of oleic acid to the polymer matrix had a smaller effect on the increase in the dielectric response than the addition of liquid crystal 5CB. Fourier transform infrared (FTIR) results revealed that the molecular structure and chemical character of the Ecoflex® and PCL matrixes remained unchanged upon the addition of SWCN or 5CB in a weight ratio of 10:0.01 and 10:1, respectively, while molecular interactions appeared between L,D-PLA and 5CB. Moreover, adding oleic acid to pure Ecoflex® as well as the binary and ternary hybrid layers with SWCN and/or 5CB in a weight ratio of Ecoflex®:oleic acid equal to 10:0.3 did not have an influence on the chemical bonding of these materials

Thermal degradation of biological DNA studied by dielectric spectroscopy

Dielectric spectroscopy was tested as an alternative tool to study degradation of deoxyribonucleic acid (DNA) in its solid form. The specimens, prepared from biological DNA, were periodically heated and cooled according to a programmed scheme. Simultaneously, their dielectric parameters (permittivity and dielectric loss) were monitored as function of frequency and temperature. The analysis of Bode plots allowed to determine the upper limit of thermal stability of solid DNA at 120 °C, because heating at higher temperatures resulted in irreversible changes. These changes were identified as denaturation by gel electrophoresis and UV–vis absorption methods

Hybrid materials based on L,D-poly(lactic acid) and Single-Walled Carbon Nanotubes as flexible substrate for organic devices

We report on the application of l,d-poly(lactic acid) (l,d-PLA) with dispersed Single-Walled Carbon Nanotubes (SWCN) as a flexible translucent electrode for organic devices. We used commercially available nanotubes in various weight ratios from 0 to 8% dispersed in chloroform polymeric solution by ultrasonication and were drop cast. The created hybrid materials were investigated by differential scanning calorimetry to determine the influence of SWCN content on the thermal behavior, while polarizing optical microscope was used to find the effect of mechanical deformations on the textures. Drop-cast films were studied by optical transmittance, conductivity, dielectric properties and by thermal imaging under applied potential. Thermal imaging provided evidence of visible voltage-activated conduction. Simple mechanical deformation such as bending with stretching at edge to ca. 90 and elongation test were performed. Moreover, interactions between l,d-poly(lactic acid) and SWCN were investigated by FT-IR and NMR spectroscopy. Finally, we can conclude that the thermographic examination of created films permits fast, simple and inexpensive localization of defects on the surface of l,d-PLA:SWCN film, together with the electrical properties of the films

A case report of Omenn syndrome in siblings

The article describes a case of Omenn syndrome in neonatal period. Omenn syndrome was diagnosed in two of three children of the same parents. Both of children had skin erythroderma since birth and eosynophilia in blood tests. The course of the disease in both cases was fatal. Condition has inborn character and autosomal recessive pattern of inheritance. Around third month of life first symptoms of the disease appear: chronic diarrhea, failure to thrive, severe infections, hepatosplenomegaly, erythroderma, loss of hair. Marrow bone transplantation or cord blood stem cell transplantation is the only treatment. Diagnosis of Omenn syndrome is difficult because of incomplete clinical picture of the disease in newborn period, rarity of disease and skin changes similar to those in ichtiosis, histiocytosis, other SCID or atopic eczema. It is particularly important to be vigilant in case of skin changes such as severe erythroderma and skin desquamation accompanied by abnormalities in blood tests. Such patients should be referred to hematological centers. Vaccination with attenuated vaccines should be postponed. Detailed laboratory tests in Omenn syndrome reveal low level of IgG, IgA, IgM and elevated level of IgE, absence of B-cell clones and abnormal amount of T-cell clones. Families burden with severe combined immunodeficiency disease (SCID) require genetic counseling. Families affected by Omenn syndrome or RAG-dependent SCID could benefit from prenatal diagnosis by detection of RAG genes mutations of fetal samples by direct sequencing