PRENATAL DIAGNOSTICS IN THE GENETIC COUNSELING - VARNA

The authors report data from the follow-up of 167 pregnancies in the Medical Genetic Counseling in Varna for the period 1996-2001. In 44% of the cases a primary prevention was aimed. It was established that parental age was the most common indication for prenatal diagnostics (PD) - in 29% of the pregnancies. It was followed by the effects of drugs and/or infectious agents (in 14%), impaired reproduction (in 12%), neural tube defects (in 11%), chromosomal diseases (in 8%), multiple anomalies (in 7%) and single gene disease (in 3%). PD under the indication of'other diseases' was carried out in 16% of the pregnancies. Data were compared to those reported by the authors for the period 1983-1987. It is emphasized that PD is a unique preventive method of a high social value

MOLECULAR GENETIC TESTS - A BASIC APPROACH FOR INVESTIGATING THE GENOME OF T H E POPULATION

Fundamental importance of molecular genetic tests in solving clinical problems is outlined. Relations between genetic counseling and laboratory for molecular pathology in putting molecular genetic tests into practice are focused. Authors look at the possibilities for immediate application of DNA analysis according to the degree of exploration of different genes, determining monogenic diseases. Attention is paid to the methods for direct and indirect DNA analysis used postnatally and prenatally both for diagnosis and prevention. Definition of 'informative' risk family is given, being an object for indirect methods of DNA analysis. Molecular genetic tests are shown as basis for research, genetic investigations of the populations and the diseases spread in them and for creating and applying mass and selective diagnostic and preventing screening programs that aim at ameliorating the human genome and decreasing the number of patients with socially significant hereditary diseases

GENETIC COUNSELING - AN APPROACH FOR SOLVING DIAGNOSTIC PROBLEMS IN CLINICAL PRACTICE

The authors report five clinical cases in which the geneticist in the genetic counseling has come across family history and pedigree data for a certain type of inheritance of the disease in the concrete family and that has been the reason for changing the clinical diagnosis. In the first case report the primary diagnosis of tu cerebri was changed to Marfan syndrome. In the second case report the diagnosis of idiopathic osteoporosis was changed to osteogenesis imperfecta, an  autosomal dominant form. In the third case report the diagnosis of Friedreich ataxia was denied and clinical thinking was focused on autosomal dominant forms of neurodegenerative entities. In the fourth case report the diagnosis of Duchenne muscular dystrophy (Ð¥-recessive disease) was not confirmed and further tests were directed to eventually finding autosomal dominant forms of progressive muscular dystrophies. In fifth case report the primary diagnosis of'diversions in the endocrine status' was not confirmed because an autosomal dominant anhydrotic ectodermal dysplasia was found out. It was pointed out that geneticist's efforts in these and other similar cases contributed to a more precise diagnosis or even changed the primary diagnosis. This optimized the work in the clinical settings and made the prevention of some hereditary diseases possible

Prediction of sanding in subsurface hydrocarbon reservoirs.

Sand production in oil and gas wells can occur if the fluid velocity exceeds a certain value. Due to drilling operations, the mechanical stresses can exceed the load bearing capacity of the rock. As the local stresses exceed certain level, a certain amount of rock is fractured into sand. Then, the sand is carried by the fluid through the wellbore depending on the flow rate. The amount of the solids can be less than a few grams per cubic meter of reservoir fluid or an essential amount. In the later case erosion of the rock and removing sufficient quantities of rock can occur. This can produce subsurface cavities which collapse and destroy the well. When sanding is unavoidable it is necessary to estimate the characteristics of the process. Our aim was to generate a simple one-dimensional local model, which predicts the volume of sanding, the radius and the porosity of the yielded zone. Such model will help the company in the development of complex 3D models

INVESTIGATIONS OF THE CONTENT OF PRENATAL DIAGNOSIS IN THE CONTINGENT OF GENETIC COUNSELLING IN NORTH-EASTERN BULGARIA

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Domain diversity and polarization switching in amino acid β-glycine

Piezoelectric materials based on lead zirconate titanate are widely used in sensors and actuators. However, their application is limited because of high processing temperature, brittleness, lack of conformal deposition and, more importantly, intrinsic incompatibility with biological environments. Recent studies on bioorganic piezoelectrics have demonstrated their potential in these applications, essentially due to using the same building blocks as those used by nature. In this work, we used piezoresponse force microscopy (PFM) to study the domain structures and polarization reversal in the smallest amino acid glycine, which recently attracted a lot of attention due to its strong shear piezoelectric activity. In this uniaxial ferroelectric, a diverse domain structure that includes both 180° and charged domain walls was observed, as well as domain wall kinks related to peculiar growth and crystallographic structure of this material. Local polarization switching was studied by applying a bias voltage to the PFM tip, and the possibility to control the resulting domain structure was demonstrated. This study has shown that the as-grown domain structure and changes in the electric field in glycine are qualitatively similar to those found in the uniaxial inorganic ferroelectrics. © 2019 by the authors

β-glycine piezoelectric and ferroelectric properties behavior at elevated temperatures

The research was carried out using equipment of Ural Center for Shared Use "Modern Nanotechnologies" Ural Federal University. The reported study was funded by RFBR according to the research project № 18-32-00390

Linear magnetoresistance in compensated graphene bilayer

We report a nonsaturating linear magnetoresistance in charge-compensated bilayer graphene in a temperature range from 1.5 to 150 K. The observed linear magnetoresistance disappears away from charge neutrality ruling out the traditional explanation of the effect in terms of the classical random resistor network model. We show that experimental results qualitatively agree with a phenomenological two-fluid model taking into account electron-hole recombination and finite-size sample geometry