Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 33 )

2018 ( 217 )

2017 ( 192 )

2016 ( 272 )

Custom range...

Search Results: 1 - 10 of 117998 matches for " Dimitar T. Atanasov "
All listed articles are free for downloading (OA Articles)
Page 1 /117998
Display every page Item
Dental Anxiety in Adults in Bulgaria
Donka G. Kirova , Dimitar T. Atanasov , Christinka K. Lalabonova , Susana Janevska
Folia Medica , 2010, DOI: 10.2478/v10153-010-0047-5
Abstract: The anxiety experienced by some patients before or during dental visits poses a problem for patients and the dental practitioners alike. Some people consider them a stressful experience which manifests itself as anxiety, fear and even phobia and results in avoidance of proper dental care. The dental anxiety, dental fear and dental phobia stand out against the background of general anxiety. The aim of the present study was to investigate dental anxiety in Bulgaria by means of a self-assessment scale. Material and methods: The self-assessment Dental Anxiety Scale (DAS), developed by N Corah, was used in the form of a questionnaire containing questions about the gender, age, education and occupation of respondents. Subjects were 746 adults aged 18-82 years living in urban areas. Individual and group interviews were conducted directly with them. Results: The respondents with moderate dental anxiety were the most of all subjects (35.5%, DAS score: 9-12 points), followed by the anxiety-free subjects (34.6%, 4-8 points). The third most numerous group was the high anxiety group (18.2%, 13-14 points), followed by the subjects with severe anxiety (11.7%, 15-20 points). The mean score was 10.26±0.14. We found a statistically significant correlation between anxiety, age (P < 0.05), education (P < 0.05) and type of labour (manual or mental labour) (P < 0.01). No significant difference was found between anxiety and sex (P > 0.05). Conclusions: The percentage of people scoring high on dental anxiety (DAS 13-20) in Bulgaria (29.9%) is considerably higher than that in some European and North American countries. The present study is the first in Bulgaria on dental anxiety. Further studies are needed to reveal other factors related to dental anxiety.
Diagnostic Strategies and Treatment for Ewing’s Sarcoma  [PDF]
Roumiana Todorova, Atanas T. Atanasov
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.36097
Abstract: Ewing’s sarcoma is an enigmatic malignancy of progenitor cell origin, driven by transcription factor oncogenic fusions. About 85% of ESFT cases harbor the t(11;22) translocation and express the fusion protein EWS-FLI. Both bone marrow-derived human Mesenchymal stem cells and Neural crest stem cells are permissive for EWS-FLI1 expression that initiates transition to ESFT-like cellular phenotype. Diagnosis of Ewing’s tumor is based on pathologic and molecular findings. The hypoxia enhances the malignancy of ESFT invasive capacity. An ALDHhigh subpopulation of Ewing’s sarcoma cells, capable of self-renewal, tumor initiation and resistant to chemotherapy in vitro, are not resistant to YK-4-279. Intensive high-dose chemotherapy followed by stem-cell reconstitution was used for ESFT patients in second remission. Plerixafor in combination with G-CSF is an effective enhance stem cell mobilization regimen for stem cell collection with lowest success rate in patients with neuroblastoma. The ESFT-derived antigens EZH2(666) and CHM1(319) are suitable targets for protective allo-restricted human CD8(+) T-cell responses against non-immunogenic ESFT. Primitive neuroectodermal features and MSC origin are both compatible with G(D2) aberrant expression and explore G(D2) immune targeting in ESFT.
Long-term variations in the correlation between NAO and solar activity: the importance of North-South solar activity asymmetry for atmospheric circulation
Katya Georgieva,Boian Kirov,Peter Tonev,Veneta Guineva,Dimitar Atanasov
Physics , 2007, DOI: 10.1016/j.asr.2007.02.091
Abstract: General atmospheric circulation is the system of atmospheric motions over the Earth on the scale of the whole globe. Two main types of circulation have been identified: zonal - characterized by low amplitude waves in the troposphere moving quickly from west to east, and meridional with stationary high amplitude waves when the meridional transfer is intensified. The prevailing type of circulation is related to global climate. Based on many years of observations, certain circulation epochs have been defined when the same type of circulation prevails for years or decades. Here we study the relation between long-term changes in solar activity and prevailing type of atmospheric circulation, using NAO index reconstructed for the last four centuries as a proxy for large-scale atmospheric circulation. We find that when the southern solar hemisphere is more active, increasing solar activity in the secular solar cycle results in increasing zonality of the circulation, while when the northern solar hemisphere is more active, increasing solar activity increases meridional circulation. In an attempt to explain the observations, we compare the short-term reaction of NAO and NAM indices to different solar drivers: powerful solar flares, high speed solar wind streams, and magnetic clouds
Chromosome polymorphism in Bulgarian populations of the striped field mouse (Apodemus agrarius Pallas 1771)
T Chassovnikarova,Nasko Atanasov,H Dimitrov
Comparative Cytogenetics , 2009, DOI: 10.3897/compcytogen.v3i1.2
Abstract: Chromosome polymorphism in Bulgarian populations of the striped field mouse (Apodemus agrarius Pallas, 1771) has been described. The diploid chromosome number is 2n=48 (NFa = 54). In the karyotype of 3 specimens from the Iskar region, the presence of an additional B chromosome has been established for the first time. The autosomes are 19 acrocentric pairs, continuously decreasing in size, and 4 pairs of bi-armed chromosomes, barely distinguishable by size and location of the centromere. Specimens with 3 pairs of metacentric chromosomes were firstly described in Bulgaria for the regions of Iskar and Omurtag. The localization of heterochromatin in the centromeric regions of the chromosomes, blocks of heterochromatin of different sizes, as well as intercalated bands, distinguishable in weakly spiraled chromosomes are found. Telomeric heterochromatin is present in the largest autosomal pair and in two of the middle-sized autosomal pairs. The largest and smallest pairs of be-armed chromosomes do not have centromeric heterochromatin, whereas all the other autosomal pairs do. The presence of a NOR in 6 chromosomal pairs is established. Two of the pairs exhibited pericentromeric NORs, whereas the other 4 displayed telomeric NORs. The karyotype analysis illustrates the chromosome and genome polymorphism of A. agrarius in Bulgarian populations.
Complex Permittivity and Permeability Studies Viewing Antenna Applications of NBR-Based Composites Comprising Conductive Fillers  [PDF]
Abdullah G. Al-Sehemi, Ahmed A. Al-Ghamdi, Nikolay T. Dishovsky, Nikolay T. Atanasov, Gabriela L. Atanasova
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.911064
Abstract: The work presents studies on the complex permittivity and permeability of composites based on acrylonitrile butadiene rubber containing combinations of conductive fillers which include carbon black and nickel powder. The properties of those composites, containing each of the fillers at the same amount were compared. The permittivity and permeability values of the composites are influenced remarkably by their morphology and structure as well as by the morphological and structural specifics of both fillers. As electron scanning microscopy studies confirm, those parameters are predetermined by the nature of the composites studied—particle size, particles arrangement in the matrix and their tendency to clustering. Last but not least matrix-filler interface phenomena also impact the characteristics in question. The possibilities for applications of the composites in antennae have been studied, in particular, as substrates and insulating layers in flexible antennae for body centric communications (BCCs). The research results allow the conclusion that these materials can find such applications indeed. Composites of higher conductivity can be used where surface waves are generated to provide on-body communications, while composites of lower conductivity may be used for antennae that will be on the body of a person and will transmit to and receive from other antennas that are not on the body of the same person (off-body communications). It is clear that one can engineer the properties of antennae substrates at microwave frequencies by adjusting the filler content and the type of filler and thus control and tailor the antenna performance specific for a particular application.
Method for Tentative Evaluation of Membrane Permeability Coefficients for Sodium and Potassium Ions in Unicellular Organisms  [PDF]
Atanas Todorov Atanasov
Open Journal of Biophysics (OJBIPHY) , 2013, DOI: 10.4236/ojbiphy.2013.31A012

The membrane permeability coefficient for sodium and potassium ions in unicellular organisms can be calculated using the data for cell volume, surface and mean generation time during growth and dividing of cells by binary. Accordingly theory of proposed method, the membrane permeability coefficients for passed trough outer cell membrane sodium and potassium ions, is equal to the volume of unicellular organism divided to product between cell surface and mean generation time of cells. The calculated by this way diapason of values overlaps with experimentally measured diapason of values of permeability coefficient for sodium and potassium ions. The deviation between the theoretically calculated and experimentally measured values of permeability coefficient does not exceed one order of magnitude.

Length of Periods in the Nasal Cycle during 24-Hours Registration  [PDF]
Atanas Todorov Atanasov
Open Journal of Biophysics (OJBIPHY) , 2014, DOI: 10.4236/ojbiphy.2014.43010
The periodic congestion and decongestion of the nasal venous sinuses and an alternation of airflow from one side of the nose to the other are known in literature as “nasal cycle”. It is established that nasal cycle during 24-hours registration contains from 4 to 8 time full periods, length of which varies from 0.80 h to 5.75 h. The mean length of all full periods is 2.80 ± 0.17 h. The mean length of full periods of left nostril is 3.07 h and the mean length of periods of right nostril is 2.43 h. The result suggests that there is any asymmetry in length of periods of airflow trough left and right nostrils about 40 min. The longer periods of left nostril can be connected with higher metabolic and functional activity of brain and human organism during active work.
Nasal Cycle Dilemma: Nasal Cycle Is Associated to Brain Wake/REM States or Is Associated to Conscious State in Them?  [PDF]
Atanas Todorov Atanasov
Open Journal of Biophysics (OJBIPHY) , 2019, DOI: 10.4236/ojbiphy.2019.91001
Abstract: Experimental and theoretical arguments have been described in favor of the hypothesis that the nasal cycle reversals of the nostril’s airflow occurs only in the consciousness states of the brain (during awake/wake state, REM state and during dreams in St.1, 2 of the non-REM sleep). This finding gives possibility to use nasal cycle as “marker for consciousness states”. An idea for clinical application of the hypothesis is proposed.
Macedonia between nationalism(s) and multiculturalism: The framework agreement and its multicultural conjectures
Atanasov Petar
Sociologija , 2003, DOI: 10.2298/soc0304303a
Abstract: This paper deals with the nationalism(s) and multiculturalism in the Macedonian society, and the multicultural democracy contingency within Macedonian practice. Furthermore, it shed lights on the implementation of the Framework Agreement after the conflict of 2001 seen through the national and multicultural paradigm In addition the paper attempts to correlate the class and the ethnicity in Macedonian socialist pre- ethnic period, with the transition processes and current Macedonian state-of-affairs The paper argues that the management of ethnic differences must reconcile the two nationalisms and in opposite direction, the 'battle' for the resources and symbols between Macedonians and Albanians will reinforce the affections toward their own national (ethnic) identity.
Implementation of subontology of Planning and control for business analysis domain
I. Atanasová
AGRIS on-line Papers in Economics and Informatics , 2011,
Abstract: Ontologies are at the heart of the semantic web. They define the concepts and relationships that make global interoperability possible. However, as these ontologies grow in size they become more and more difficult to create, use, understand, maintain, transform and classify. As ontologies become common in more applications and as those applications become larger and longer-lived, it is becoming increasingly common for ontologies to be developed in different area of public sector of economics. Ontologies present special challenges to the problem of conceptual modeling. This paper describes the process of the implementation of a subontology of forecasting and evaluations for business analysis domain in order to develop an easy and correct way to find the needed statistical information in a knowledge base.
Page 1 /117998
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.