Mirela Nicolov - Academia.edu (original) (raw)

Papers by Mirela Nicolov

Research paper thumbnail of Hydrosoluble and Liposoluble Vitamins: New Perspectives through ADMET Analysis

Medicina

Background and Objectives: The present study demonstrates that apart from the well-known toxicity... more Background and Objectives: The present study demonstrates that apart from the well-known toxicity of liposoluble vitamins, some hydrosoluble vitamins may also exert toxicity; thus, routine supplementation with vitamins or ingestion of fortified foods should not be considered harmless. The study addresses the possible correlations between the physico-chemical properties and the side effects of vitamins when taken in high doses or for a too long a period. Materials and Methods: The FAFDrugs4.0 computational tool was used for computational assessment of the ADMET profile of several hydro- and liposoluble vitamins. Results: ADMET analysis revealed the following major data: vitamin B3 and B13 showed reduced structural complexity; thus, a relative toxicological potential may be exerted. Vitamins B1 and B7 were found to have good oral absorption and thus good bioavailability, while Vitamin B3 was found to have decreased oral absorption. In addition, all of the liposoluble vitamins reflecte...

Research paper thumbnail of Different Types of Innovations Modeling

Proceedings of the 23rd International DAAAM Symposium 2012

Research paper thumbnail of Open Innovation in Practice – Case of Romania

Proceedings of the 23rd International DAAAM Symposium 2012

Research paper thumbnail of Comparative Toxicological In Vitro and In Ovo Screening of Different Orthodontic Implants Currently Used in Dentistry

Materials

Selecting the most biocompatible orthodontic implant available on the market may be a major chall... more Selecting the most biocompatible orthodontic implant available on the market may be a major challenge, given the wide array of orthodontic devices currently available on the market. The latest scientific data have suggested that in vitro evaluations using oral cell lines provide reliable data regarding the toxicity of residual particles released by different types of orthodontic devices. In this regard, the in vitro biocompatibility of three different commercially available implants (stainless steel and titanium-based implants) was assessed. Methods: As an in vitro model, human gingival fibroblasts (HGFs) were employed to evaluate the cellular morphology, cell viability, and cytotoxicity by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays at 24 h and 72 h post-exposure to test implants. Results: The results correlate the composition and topography of the implant surface with biological experimental evaluations related...

Research paper thumbnail of Biostatistical Analysis and Possible Forecasting of Relationship Between Uric Acid and Specific Laboratory Tests in Cases of Gouty Arthritis

Revista de Chimie

Acute gouty arthritis represents an inflammatory response to microcrystals of monosodium urate th... more Acute gouty arthritis represents an inflammatory response to microcrystals of monosodium urate that precipitate in joint tissues from supersaturated body fluids or are shed from preexisting articular deposits [1]. Gout is a metabolic disease characterized by recurrent episodes of arthritis associated with the presence of monosodium urate crystals in the tissue or synovial fluid during the attack.These forms of crystal-induced arthritis usually affect peripheral joints, including knee, ankle, wrist, and metacarpophalangeal and metatarsophalangeal joints. All of them may be associated with other inflammatory, endocrine diseases [2]. The present study was done to highlight the relationship between increased levels of uric acid and specific laboratory tests in order to possible forecast development of further disease in patients with gouty arthrithis.The present study was done on 34 patients hospitalized in Felix Hospital of Rehabilitation in 2015-2016, with age between 44 and 74, havin...

Research paper thumbnail of Is there a Need for Own Median Calculation in the Second Trimester Biochemical Markers Screening?

Revista de Chimie

Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fe... more Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fetal medicine. The aim of our study was to analyze if the medians recommended by the manufacturers are adequate to perform an accurate screening or if there is a need for own laboratory medians calculation in second trimester biochemical marker screening.Sera were collected between 14 wp and 22 wp from 3374 singleton pregnancies. We analyzed three second trimester biochemical markers (AFP, hCG and free Estriol) concentration in all pregnant women and in a subgroup of pregnant women in which gestational age was determined based on crown-rump length. Our results showed that for all biochemical markers the difference between the manufacturer and the own calculated median was lower than 10% excepting the hCG value in the group of pregnant women in which the gestational age was determined on basis of crown-rump-length. Our results show it is recommended to replace the values of the median for ...

Research paper thumbnail of Hartman Perdok Method Applied to A2BSi2O7 and AB2O6 Types of Microcrystals and the Concept of Fractional Charges

Revista de Chimie

Using the concept of Fractional Charges were calculate the attachment energies and was simulated ... more Using the concept of Fractional Charges were calculate the attachment energies and was simulated the growth form of quartz crystals in the past. In this paper , by using the concept of normal and fractional charges in the system for A2BSi2O7 and AB2O6 types of crystals, will be computed the attachment energies and it will be done the conclusions of influences of fractional charges in the system for energies calculations the first step in Hartman Perdok Method applied to microcrystals.

Research paper thumbnail of Neutral density filters with Risley prisms: analysis and design

Applied Optics, Jun 1, 2009

We achieve the analysis and design of optical attenuators with double-prism neutral density filte... more We achieve the analysis and design of optical attenuators with double-prism neutral density filters. A comparative study is performed on three possible device configurations; only two are presented in the literature but without their design calculus. The characteristic parameters of this optical attenuator with Risley translating prisms for each of the three setups are defined and their analytical expressions are derived: adjustment scale (attenuation range) and interval, minimum transmission coefficient and sensitivity. The setups are compared to select the optimal device, and, from this study, the best solution for double-prism neutral density filters, both from a mechanical and an optical point of view, is determined with two identical, symmetrically movable, no mechanical contact prisms. The design calculus of this optimal device is developed in essential steps. The parameters of the prisms, particularly their angles, are studied to improve the design, and we demonstrate the maximum attenuation range that this type of attenuator can provide.

Research paper thumbnail of Growth form of TiO2

Crystal Research and Technology, 2003

Computation of attachment energies, which are considered to be directly related to the growth rat... more Computation of attachment energies, which are considered to be directly related to the growth rates of the corresponding F faces of the TiO 2 crystal structure, have been calculated in an electrostatic point charge model. Corrections using van der Waals attractions and Born repulsions were used in normal calculations and then in calculations of attachment energies, crystal energies and surface energies using Buckingam potentials potentials and short range potentials according to Post. With this were constructed growth and equilibrium form of TiO 2 crystals.

Research paper thumbnail of Cocrystal Formation of Betulinic Acid and Ascorbic Acid: Synthesis, Physico-Chemical Assessment, Antioxidant, and Antiproliferative Activity

Frontiers in Chemistry

Betulinic acid (BA) was demonstrated to be a very promising anticancer agent against various tumo... more Betulinic acid (BA) was demonstrated to be a very promising anticancer agent against various tumor cell lines such as breast, colon, lung, and brain. Despite its strong cytotoxic effect, betulinic acid exhibits low water solubility, feature that is reflected in its poor bioavailability. To overcome these drawbacks, numerous strategies were conducted to improve its physicochemical and pharmacokinetic profile, among which cocrystalization emerged as a promising approach. Thus, our work consisted in obtaining slowly grown cocrystals of BA and ascorbic acid (BA+VitC) in isopropyl alcohol obtained in a hydrothermal experiment. The newly formed cocrystals were characterized by physico-chemical methods such asSEM, DSC, XRPD, and FT-IR spectroscopy demonstrating BA+VitC cocrystal formation while their antioxidant activity revealed an additive antioxidant effect. To investigate the biological effect, BA+VitC cocrystals were tested on HaCat (immortalized human keratinocytes), B164A5 and B16F0 (murine melanoma), MCF7 and MDA-MB-231 (human breast cancer), and HeLa (cervical cancer) cell lines. Results of BA upon the tested tumor cell lines, after cocrystallization with vitamin C, indicated a superior cytotoxic effect with the preservation of a good selectivity index assumably due to an improved BA water solubility and consequently an optimized bioavailability.

Research paper thumbnail of Theoretical and Experimental Analysis of SiO2 - a Proof of Hartman Perdok Method

Revista de Chimie

In the present paper is done a comparison between simulation of the growth form of quartz crystal... more In the present paper is done a comparison between simulation of the growth form of quartz crystal using attachment energies and SEM and AFM analysis. This comparison is done to make a complete analysis of quartz crystal. This analysis from theory to experiment and to applications for a-SiO2 presents a complete study of how are the results from simulations of growth forms of quartz crystals and which are the proofs given by SEM and AFM analysis that the obtained crystals are like in the simulations.

Research paper thumbnail of Regional Analysis of HR Involved in Rdi Sector in Romania in the Last Decade

Research paper thumbnail of The Phenomenon of Increasing Value of Stock Capital on Romanian Market

Research paper thumbnail of Revista de Chimie

Revista de Chimie -Bucharest- Original Edition-

This paper deal with an analysis of the growth and equilibrium form of oxides crystals from the p... more This paper deal with an analysis of the growth and equilibrium form of oxides crystals from the point of view of Wigner Seitz and Brillouin zone analysis based on the computer simulation of SiO 2 and TiO 2 . These methods are robust and suitable to predict the growing and equilibrium form of the crystals in the future. The significance, and novelty of this work is high because it can be applied in fields such as healthcare and pharmaceuticals, environmental and forensic analysis, as well as in agricultural science and food products.

Research paper thumbnail of Urea Simulation as a Bifunctional Material Mirela Nicolov, Zoltan Szabadai, Cristina Trandafirescu, Dan Dragos Rev. Chim. (Bucharest), 2015:66(5), 681-684

Research paper thumbnail of March 2013 Classified Advertisements

Research paper thumbnail of Studies of Innovations in West Region of Romania Studii Ale Inovaţiilor În Regiunea De Vest a României

In the present paper an analysis of Human resources (HR) in the research Development and innovati... more In the present paper an analysis of Human resources (HR) in the research Development and innovation (RDI) system from the west part of Romania, between 2000 and 2010 is done.

Research paper thumbnail of Innovations in Smes in the Service Sector in Romania Between 2000 and 2008 and Entrepreneurship as Application with Some Outputs

In the present paper we study how we can measure innovation in SMEs per total and in the sector o... more In the present paper we study how we can measure innovation in SMEs per total and in the sector of services .We present here a study done on the values of the share of turnover of innovative product business with innovations from the total turnover of innovative enterprises by size, class and economic activity expressed in percentage . The values used in the present study are for Romania in the period 2000 and 2008, when were the first registration for these types of data. We study the following cases: products unchanged or partially changed, new or significantly improved products, new business and new or significantly improved products, new market. Studies are made for total, small and medium SMEs and for the service sector. Keywords: innovations, SME (small and medium enterprises), service,entrepreneuship.

Research paper thumbnail of Modelling European Public Finance and Support for RDI Sector

Procedia Economics and Finance, 2013

In the present paper is introduced an econophysics model for the public finance and support in th... more In the present paper is introduced an econophysics model for the public finance and support in the European RDI sector, especially for EU15 respectively EU25.

Research paper thumbnail of Analysis of Relationship between Net Wage and Consumer Price Index

Procedia Economics and Finance, 2013

In the present paper is presented an econometric analysis of the relationship between net salary ... more In the present paper is presented an econometric analysis of the relationship between net salary and consumer price index. After a brief historical overview will be review the calculating statistics for selected variables and coefficients and will be presented the obtained values. We will study the relationship between variables. It will be realized the cloud of points and will be applied Fisher test. The intensity of selected variables will be study too and some forms of relationship between the two chose variables will be done. Student test is applied. It will be performed the parameter estimation for regression functions and Akaike's criterion will be applied. The homoscedasticity assumptions, graphical method, Durbin-Watson test will be applied. All econometric study will is done using the software E-View 4.

Research paper thumbnail of Hydrosoluble and Liposoluble Vitamins: New Perspectives through ADMET Analysis

Medicina

Background and Objectives: The present study demonstrates that apart from the well-known toxicity... more Background and Objectives: The present study demonstrates that apart from the well-known toxicity of liposoluble vitamins, some hydrosoluble vitamins may also exert toxicity; thus, routine supplementation with vitamins or ingestion of fortified foods should not be considered harmless. The study addresses the possible correlations between the physico-chemical properties and the side effects of vitamins when taken in high doses or for a too long a period. Materials and Methods: The FAFDrugs4.0 computational tool was used for computational assessment of the ADMET profile of several hydro- and liposoluble vitamins. Results: ADMET analysis revealed the following major data: vitamin B3 and B13 showed reduced structural complexity; thus, a relative toxicological potential may be exerted. Vitamins B1 and B7 were found to have good oral absorption and thus good bioavailability, while Vitamin B3 was found to have decreased oral absorption. In addition, all of the liposoluble vitamins reflecte...

Research paper thumbnail of Different Types of Innovations Modeling

Proceedings of the 23rd International DAAAM Symposium 2012

Research paper thumbnail of Open Innovation in Practice – Case of Romania

Proceedings of the 23rd International DAAAM Symposium 2012

Research paper thumbnail of Comparative Toxicological In Vitro and In Ovo Screening of Different Orthodontic Implants Currently Used in Dentistry

Materials

Selecting the most biocompatible orthodontic implant available on the market may be a major chall... more Selecting the most biocompatible orthodontic implant available on the market may be a major challenge, given the wide array of orthodontic devices currently available on the market. The latest scientific data have suggested that in vitro evaluations using oral cell lines provide reliable data regarding the toxicity of residual particles released by different types of orthodontic devices. In this regard, the in vitro biocompatibility of three different commercially available implants (stainless steel and titanium-based implants) was assessed. Methods: As an in vitro model, human gingival fibroblasts (HGFs) were employed to evaluate the cellular morphology, cell viability, and cytotoxicity by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays at 24 h and 72 h post-exposure to test implants. Results: The results correlate the composition and topography of the implant surface with biological experimental evaluations related...

Research paper thumbnail of Biostatistical Analysis and Possible Forecasting of Relationship Between Uric Acid and Specific Laboratory Tests in Cases of Gouty Arthritis

Revista de Chimie

Acute gouty arthritis represents an inflammatory response to microcrystals of monosodium urate th... more Acute gouty arthritis represents an inflammatory response to microcrystals of monosodium urate that precipitate in joint tissues from supersaturated body fluids or are shed from preexisting articular deposits [1]. Gout is a metabolic disease characterized by recurrent episodes of arthritis associated with the presence of monosodium urate crystals in the tissue or synovial fluid during the attack.These forms of crystal-induced arthritis usually affect peripheral joints, including knee, ankle, wrist, and metacarpophalangeal and metatarsophalangeal joints. All of them may be associated with other inflammatory, endocrine diseases [2]. The present study was done to highlight the relationship between increased levels of uric acid and specific laboratory tests in order to possible forecast development of further disease in patients with gouty arthrithis.The present study was done on 34 patients hospitalized in Felix Hospital of Rehabilitation in 2015-2016, with age between 44 and 74, havin...

Research paper thumbnail of Is there a Need for Own Median Calculation in the Second Trimester Biochemical Markers Screening?

Revista de Chimie

Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fe... more Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fetal medicine. The aim of our study was to analyze if the medians recommended by the manufacturers are adequate to perform an accurate screening or if there is a need for own laboratory medians calculation in second trimester biochemical marker screening.Sera were collected between 14 wp and 22 wp from 3374 singleton pregnancies. We analyzed three second trimester biochemical markers (AFP, hCG and free Estriol) concentration in all pregnant women and in a subgroup of pregnant women in which gestational age was determined based on crown-rump length. Our results showed that for all biochemical markers the difference between the manufacturer and the own calculated median was lower than 10% excepting the hCG value in the group of pregnant women in which the gestational age was determined on basis of crown-rump-length. Our results show it is recommended to replace the values of the median for ...

Research paper thumbnail of Hartman Perdok Method Applied to A2BSi2O7 and AB2O6 Types of Microcrystals and the Concept of Fractional Charges

Revista de Chimie

Using the concept of Fractional Charges were calculate the attachment energies and was simulated ... more Using the concept of Fractional Charges were calculate the attachment energies and was simulated the growth form of quartz crystals in the past. In this paper , by using the concept of normal and fractional charges in the system for A2BSi2O7 and AB2O6 types of crystals, will be computed the attachment energies and it will be done the conclusions of influences of fractional charges in the system for energies calculations the first step in Hartman Perdok Method applied to microcrystals.

Research paper thumbnail of Neutral density filters with Risley prisms: analysis and design

Applied Optics, Jun 1, 2009

We achieve the analysis and design of optical attenuators with double-prism neutral density filte... more We achieve the analysis and design of optical attenuators with double-prism neutral density filters. A comparative study is performed on three possible device configurations; only two are presented in the literature but without their design calculus. The characteristic parameters of this optical attenuator with Risley translating prisms for each of the three setups are defined and their analytical expressions are derived: adjustment scale (attenuation range) and interval, minimum transmission coefficient and sensitivity. The setups are compared to select the optimal device, and, from this study, the best solution for double-prism neutral density filters, both from a mechanical and an optical point of view, is determined with two identical, symmetrically movable, no mechanical contact prisms. The design calculus of this optimal device is developed in essential steps. The parameters of the prisms, particularly their angles, are studied to improve the design, and we demonstrate the maximum attenuation range that this type of attenuator can provide.

Research paper thumbnail of Growth form of TiO2

Crystal Research and Technology, 2003

Computation of attachment energies, which are considered to be directly related to the growth rat... more Computation of attachment energies, which are considered to be directly related to the growth rates of the corresponding F faces of the TiO 2 crystal structure, have been calculated in an electrostatic point charge model. Corrections using van der Waals attractions and Born repulsions were used in normal calculations and then in calculations of attachment energies, crystal energies and surface energies using Buckingam potentials potentials and short range potentials according to Post. With this were constructed growth and equilibrium form of TiO 2 crystals.

Research paper thumbnail of Cocrystal Formation of Betulinic Acid and Ascorbic Acid: Synthesis, Physico-Chemical Assessment, Antioxidant, and Antiproliferative Activity

Frontiers in Chemistry

Betulinic acid (BA) was demonstrated to be a very promising anticancer agent against various tumo... more Betulinic acid (BA) was demonstrated to be a very promising anticancer agent against various tumor cell lines such as breast, colon, lung, and brain. Despite its strong cytotoxic effect, betulinic acid exhibits low water solubility, feature that is reflected in its poor bioavailability. To overcome these drawbacks, numerous strategies were conducted to improve its physicochemical and pharmacokinetic profile, among which cocrystalization emerged as a promising approach. Thus, our work consisted in obtaining slowly grown cocrystals of BA and ascorbic acid (BA+VitC) in isopropyl alcohol obtained in a hydrothermal experiment. The newly formed cocrystals were characterized by physico-chemical methods such asSEM, DSC, XRPD, and FT-IR spectroscopy demonstrating BA+VitC cocrystal formation while their antioxidant activity revealed an additive antioxidant effect. To investigate the biological effect, BA+VitC cocrystals were tested on HaCat (immortalized human keratinocytes), B164A5 and B16F0 (murine melanoma), MCF7 and MDA-MB-231 (human breast cancer), and HeLa (cervical cancer) cell lines. Results of BA upon the tested tumor cell lines, after cocrystallization with vitamin C, indicated a superior cytotoxic effect with the preservation of a good selectivity index assumably due to an improved BA water solubility and consequently an optimized bioavailability.

Research paper thumbnail of Theoretical and Experimental Analysis of SiO2 - a Proof of Hartman Perdok Method

Revista de Chimie

In the present paper is done a comparison between simulation of the growth form of quartz crystal... more In the present paper is done a comparison between simulation of the growth form of quartz crystal using attachment energies and SEM and AFM analysis. This comparison is done to make a complete analysis of quartz crystal. This analysis from theory to experiment and to applications for a-SiO2 presents a complete study of how are the results from simulations of growth forms of quartz crystals and which are the proofs given by SEM and AFM analysis that the obtained crystals are like in the simulations.

Research paper thumbnail of Regional Analysis of HR Involved in Rdi Sector in Romania in the Last Decade

Research paper thumbnail of The Phenomenon of Increasing Value of Stock Capital on Romanian Market

Research paper thumbnail of Revista de Chimie

Revista de Chimie -Bucharest- Original Edition-

This paper deal with an analysis of the growth and equilibrium form of oxides crystals from the p... more This paper deal with an analysis of the growth and equilibrium form of oxides crystals from the point of view of Wigner Seitz and Brillouin zone analysis based on the computer simulation of SiO 2 and TiO 2 . These methods are robust and suitable to predict the growing and equilibrium form of the crystals in the future. The significance, and novelty of this work is high because it can be applied in fields such as healthcare and pharmaceuticals, environmental and forensic analysis, as well as in agricultural science and food products.

Research paper thumbnail of Urea Simulation as a Bifunctional Material Mirela Nicolov, Zoltan Szabadai, Cristina Trandafirescu, Dan Dragos Rev. Chim. (Bucharest), 2015:66(5), 681-684

Research paper thumbnail of March 2013 Classified Advertisements

Research paper thumbnail of Studies of Innovations in West Region of Romania Studii Ale Inovaţiilor În Regiunea De Vest a României

In the present paper an analysis of Human resources (HR) in the research Development and innovati... more In the present paper an analysis of Human resources (HR) in the research Development and innovation (RDI) system from the west part of Romania, between 2000 and 2010 is done.

Research paper thumbnail of Innovations in Smes in the Service Sector in Romania Between 2000 and 2008 and Entrepreneurship as Application with Some Outputs

In the present paper we study how we can measure innovation in SMEs per total and in the sector o... more In the present paper we study how we can measure innovation in SMEs per total and in the sector of services .We present here a study done on the values of the share of turnover of innovative product business with innovations from the total turnover of innovative enterprises by size, class and economic activity expressed in percentage . The values used in the present study are for Romania in the period 2000 and 2008, when were the first registration for these types of data. We study the following cases: products unchanged or partially changed, new or significantly improved products, new business and new or significantly improved products, new market. Studies are made for total, small and medium SMEs and for the service sector. Keywords: innovations, SME (small and medium enterprises), service,entrepreneuship.

Research paper thumbnail of Modelling European Public Finance and Support for RDI Sector

Procedia Economics and Finance, 2013

In the present paper is introduced an econophysics model for the public finance and support in th... more In the present paper is introduced an econophysics model for the public finance and support in the European RDI sector, especially for EU15 respectively EU25.

Research paper thumbnail of Analysis of Relationship between Net Wage and Consumer Price Index

Procedia Economics and Finance, 2013

In the present paper is presented an econometric analysis of the relationship between net salary ... more In the present paper is presented an econometric analysis of the relationship between net salary and consumer price index. After a brief historical overview will be review the calculating statistics for selected variables and coefficients and will be presented the obtained values. We will study the relationship between variables. It will be realized the cloud of points and will be applied Fisher test. The intensity of selected variables will be study too and some forms of relationship between the two chose variables will be done. Student test is applied. It will be performed the parameter estimation for regression functions and Akaike's criterion will be applied. The homoscedasticity assumptions, graphical method, Durbin-Watson test will be applied. All econometric study will is done using the software E-View 4.