38 results on '"Daniela Istrati"'
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2. A Method for Binary Quadratic Programming with Circulant Matrix
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Daniela Istrati, Vasile Moraru, and Sergiu Zaporojan
- Abstract
Binary quadratic programming is a classical combinatorial optimization problem that has many real-world applications. This paper presents a method for solving the quadratic programming problem with circulant matrix by reformulating and relaxing it into a separable optimization problem. The proposed method determines local suboptimal solutions. To solve the relaxing problem, the DCA algorithm it is proposed to calculate the solutions, in the general case, only local suboptimal.
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- 2022
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3. A Brief Overview of Intelligent Interfaces in Production Systems
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Daniela Istrati
- Abstract
This paper presents a state of the art in field of intelligent user interfaces, which are the main elements that make the interaction between humans and machines in the most efficient, natural, effective way. As an interdisciplinary product, the design of user interfaces represents the combination of models from disciplines like software engineering, artificial intelligence, human-computer interaction and other disciplines (sociology, psychology, etc.). In the process of design and operation of production systems, an important factor is its responsiveness and the ability to have integrated the capacity to change over time and functionally. To achieve a high level of structural configuration and feasibility, a production system must have a compatible interface.
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- 2022
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4. Extraction, Quantification and Characterization Techniques for Anthocyanin Compounds in Various Food Matrices—A Review
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Daniela Istrati and Oana Constantin
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Plant Science ,Horticulture - Abstract
Anthocyanins are water-soluble pigments characterized by various intense colors found in fruits and vegetables. Scientific studies have shown growing evidence to support their health benefits. Therefore, estimating the anthocyanin content in food is essential to identify the ideal analytical method. Moreover, due to the instability of plant anthocyanins, it is important to select and optimize their extraction, separation and qualitative and quantitative analysis, steps that are indispensable and important in their study. The present article reviews the latest procedures for extracting anthocyanins from various food matrices and analytical methods for their quantification. Therefore, various forms of preliminary treatments of samples for anthocyanin extraction, extraction procedures for various fruits, vegetables and cereals, purification of samples and quantification of anthocyanins are highlighted and evaluated. Using ultrasound-assisted extraction (UAE) might be effective for anthocyanin extraction and the Amberlite XAD-7HP method is the most effective for purifying anthocyanins. Combining the liquid chromatography (LC) method with electrospray ionization (ESI) and mass spectrometry (MS) or quadrupole time-of-flight (QTOF) with mass spectrometry (MS) better quantifies the anthocyanins in the food complex samples. Therefore, the extraction and separation of anthocyanins and their qualitative and quantitative analyses are essential steps in their research. As a result, the study concentrates on a detailed characterization of various qualitative and quantitative analytical methodologies, while briefly describing the main anthocyanin extraction processes.
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- 2022
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5. Low Release Study of Cefotaxime by Functionalized Mesoporous Silica Nanomaterials
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Dan Eduard Mihaiescu, Daniela Istrati, Alina Moroșan, Maria Stanca, Bogdan Purcăreanu, Rodica Cristescu, Bogdan Ștefan Vasile, and Roxana Doina Trușca
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Biomaterials ,Polymers and Plastics ,Organic Chemistry ,Bioengineering ,MCM-41 ,sol–gel ,low release ,cefotaxime ,mesoporous material - Abstract
As a third-generation β-lactam antibiotic, cefotaxime shows a broad-spectrum with Gram-positive and Gram-negative bacteria activity and is included in WHO’s essential drug list. In order to obtain new materials with sustained release properties, the present research focuses on the study of cefotaxime absorption and desorption from different functionalized mesoporous silica supports. The MCM-41-type nanostructured mesoporous silica support was synthesized by sol–gel technique using a tetraethyl orthosilicate (TEOS) route and cetyltrimethylammonium bromide (CTAB) as a surfactant, at room temperature and normal pressure. The obtained mesoporous material (MCM-41 class) was characterized through nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), N2 absorption–desorption (BET) and Fourier transform infrared spectroscopy (FT-IR), proving a good micro-structured homogeneity (SEM images), a high surface area (BET, 1029 m2/g) correlated with high silanolic activity (Q3/Q4 peak ratio from 29Si MAS-NMR), and an expected uniform hexagonal structure (2–3 nm, HRTEM). In order to non-destructively link the antibiotic compound on the solid phase, MCM-41 was further functionalized in two steps: with aminopropyl trimethoxysilane (APTMS) and glutaraldehyde (GA). Three cefotaxime-loaded materials were comparatively studied for low release capacity: the reference material with adsorbed cefotaxime on MCM-41, MCM-41/APS (aminopropyl silyl surface functionalization) adsorbed cefotaxime material, and APTMS–GA bounded MCM-41—cefotaxime material. The slow-release profiles were obtained by using an on-flow modified HPLC system. A significant improved release capacity was identified in the case of MCM-41/APS/GA—cefotaxime due to the covalent surface grafting of the biological active compound, recommending this class of materials as an effective carrier of bioactive compounds in wound dressing, anti-biofilm coatings, advanced drugs, and other related applications.
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- 2022
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6. Solution for green organic thin film transistors: Fe3O4 nano-core with PABA external shell as p-type film
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Dan Eduard Mihaiescu, Roxana Trusca, Daniela Istrati, Rodica Cristescu, Bogdan Stefan Vasile, Bogdan Purcareanu, Alina Morosan, and Cristian Ravariu
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010302 applied physics ,Materials science ,Nanoparticle ,Condensed Matter Physics ,01 natural sciences ,Ferrite core ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Threshold voltage ,Chemical engineering ,Thin-film transistor ,0103 physical sciences ,Nano ,Zeta potential ,Electrical and Electronic Engineering ,Thin film ,Saturation (magnetic) - Abstract
We report the first successful green synthesis route for organic transistors based on para-aminobenzoic acid (PABA) grafted to ferrite nanoparticles, at room temperature. The obtained core–shell nanoparticles (NCS) have been investigated by DLS, FT-IR, SEM, TEM. Both average hydrodynamic diameter and zeta potential of synthesized PABA-NCS nanoparticles has been identified, indicating a good stability of this nano-compound. SEM analysis proved a heterogeneous structured material with quasi-uniform granular formations in size, while TEM revealed a ferrite core of 20 nm. The measurements of output characteristics in the saturation regime and transfer characteristics at negative gate voltages have proved that an organic transistor based on PABA-NCS has been accomplished. The current increasing over a negative threshold voltage demonstrated an accumulation channel onset in the PABA-NCS thin film. This is a final argument for the p-type behavior of the PABA-NCS film.
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- 2020
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7. Correlation of isoconcentration profiles resolution of water parameters with on-site sampling methodology
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Anca Marton, Ioan Calinescu, Alexandru Dan Ionescu, Dan Eduard Mihaiescu, Daniela Istrati, Mariana Carmela Horja, and Gheorghe Viorel Ungureanu
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Correlation ,Resolution (electron density) ,Environmental science ,General Chemistry ,On site sampling ,Remote sensing - Published
- 2020
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8. Functionalized silica shell magnetic nanoparticles for nanophase peptide synthesis applications
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Mihai Radu, Dan Eduard Mihaiescu, Daniela Istrati, Alina Morosan, Georgeta Voicu, Raluca Stan, and Anamaria Hanganu
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chemistry.chemical_classification ,Materials science ,Coprecipitation ,Peptide ,02 engineering and technology ,General Chemistry ,Tripeptide ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,Solid-phase synthesis ,chemistry ,Mechanics of Materials ,Peptide synthesis ,Magnetic nanoparticles ,General Materials Science ,0210 nano-technology ,Linker ,Magnetite - Abstract
A new nanostructured solid phase synthesis magnetic support consisting of core-shell type magnetic nanoparticles based on magnetite, para-aminobenzoic acid (PABA) and secondary silica shell were synthesized by coprecipitation method and characterized. An newly designed organic linker with an ending hydroxyl group inspired by HMBA linker (4-hydroxy methyl benzamide) widely employed in classical peptide solid phase synthesis was obtained from 1,4-dimethylolbenzene and gamma-isocyanatopropyltriethoxysilane and was grafted on the surface in order to be used for the nanophase synthesis of peptides. Three reaction stages, yielding a tripeptide sequence, using n-terminal protected amino acids and the principle of solid phase synthesis through the Fmoc strategy were performed, in order to prove the effectiveness of the nanophase peptide synthesis. The MS analysis confirmed the success of the tripeptide synthesis, recommending the new nanostructured system as a solid support in the solid phase synthesis of peptides. The intermediate and final materials were analysed by advanced characterization methods (SEM, TEM, BET, X-ray diffraction, magnetic properties, DLS, FT-IR, NMR for organic intermediates characterization, TGA and LC-MS).
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- 2019
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9. Synthesis and Characterization of a Core-shell Material Using YBa2Cu3O7-d and Cobalt Ferrite Nanoparticles
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Dan Eduard Mihaiescu, Maria Colie, Adrian Fudulu, Bogdan Stefan Vasile, Ecaterina Andronescu, Daniela Istrati, Nicolae Stanica, and Adrian Surdu
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Core shell ,Materials science ,Chemical engineering ,Materials Science (miscellaneous) ,Process Chemistry and Technology ,Materials Chemistry ,General Engineering ,Cobalt ferrite nanoparticles ,General Chemistry ,General Medicine ,General Pharmacology, Toxicology and Pharmaceutics ,General Biochemistry, Genetics and Molecular Biology ,Characterization (materials science) - Abstract
In this paper we describe the synthesis of a core-shell material using yttrium superconducting ceramic material (YBCO) and cobalt ferrite nanoparticles in order to obtain a nanostructured material with magnetic properties. The advantages of such material aim the selective deposition of nanofilms oriented in magnetic fields. To obtain this core-shell material, the solutions of the nitrates were first obtained by dissolving the salts in demineralised water. The suspension with cobalt ferrite nanoparticles was obtained by co-precipitation method. To obtain YBa2Cu3O7-�- coated magnetic nanoparticles by autocombustion reaction the solutions of nitrates and citric acid were used. The ratio of the metal ions: Y:Ba:Cu was 1:2:3, and between the oxidant and the reducing agent was used a citrate / nitrate mass ratio equal with 0.7. The final material was analyzed by X-ray diffraction (XRD), electronic scanning microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM).
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- 2019
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10. Marigold extract, azelaic acid and black caraway oil into lipid nanocarriers provides a strong anti-inflammatory effect in vivo
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I. Rasit, Gabriela Badea, Ioana Lacatusu, A.M. Seciu, Nicoleta Badea, N. Bordei, M. Popescu, M.I. Panteli, Daniela Istrati, and L. Moldovan
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chemistry.chemical_classification ,Azelaic acid ,Biocompatibility ,medicine.drug_class ,02 engineering and technology ,Pharmacology ,021001 nanoscience & nanotechnology ,Anti-inflammatory ,Carrageenan ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Pulmonary surfactant ,Biochemistry ,chemistry ,In vivo ,030220 oncology & carcinogenesis ,medicine ,Viability assay ,0210 nano-technology ,Agronomy and Crop Science ,Carotenoid ,medicine.drug - Abstract
Therapeutic benefits of phytochemicals are widespread, but the association of natural lipophilic and hydrophilic compounds in the same nanostructured delivery system represents a challenge that was not considered up to present. This work aimed to evaluate the effects of two plant-derived oils rich in ω-3 (rosehip oil – Ro) and ω-6 (black caraway oil – Bco) on the synthesis of marigold extract (ME) and azelaic acid (AzA) co-loaded nanostructured lipid carriers (NLC) and to determine its in vitro and in vivo anti-inflammatory action. The lipid core and surfactant shell guaranteed a high encapsulation efficiency of both water soluble-AzA and lipid soluble-ME (93% entrapment for carotenoids and 83% for AzA). A high degree of biocompatibility in the concentration range of 5–400 μg/mL NLC-ME-AzA for 72 h of treatment was determined (i.e. at 400 μg/mL the L929 cells displayed a proliferative effect with a cell viability of 110%). The co-presence of ME and AzA in the same NLC was accompanied by a reduced expression of inflammatory IL-6 and IL-1β cytokines, as evidenced by ELISA method. The in vivo plestismometric method showed that paw edema was significantly reduced for 3 h following NLC-ME-AzA hydrogel treatment (0.006 mg ME and 26.2 mg AAz) in rats challenged with carrageenan.
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- 2017
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11. Fermented Functional Beverages
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Camelia Vizireanu, E. Pricop, Alina G. Profir, and Daniela Istrati
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business.industry ,InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,Medicine ,Fermentation ,Food science ,business ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) - Published
- 2019
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12. Functional Properties of Snack Bars
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Daniela Istrati and Oana Emilia Constantin
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InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,Biology ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) - Published
- 2019
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13. Experimental Characteristics of Organic Transistor with Silver Gate
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Alina Morosan, Cristian Ravariu, Daniela Istrati, and Dan Eduard Mihaiescu
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Materials science ,business.industry ,Transistor ,Doping ,Shell (structure) ,Hardware_PERFORMANCEANDRELIABILITY ,Substrate (electronics) ,equipment and supplies ,Acceptor ,Dip-coating ,law.invention ,law ,Logic gate ,Hardware_INTEGRATEDCIRCUITS ,Optoelectronics ,business ,Hardware_LOGICDESIGN ,Voltage - Abstract
The applications of nano-core materials with doped external shell by para-amino-benzoic acid to construct an organic transistor are presented. The transistor adopts a typical configuration of an organic transistor, but using point contacts as a pseudo-MOS transistor. The device is prepared by Ag deposition on a glass substrate, followed by dip coating depositions for the organic materials. The measured static characteristics revealed acceptor behavior of the active film, indicating the accumulation onset at negative gate voltage. At higher voltages, some oscillations are recorded in this device with silver gate.
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- 2019
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14. Simulation and Experimental Studies about Proper Electrodes of an Organic Thin Film Transistor
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Alina Morosan, Daniela Istrati, Florin Babarada, Cristian Ravariu, and Dan Eduard Mihaiescu
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Electrode material ,Materials science ,business.industry ,Transistor ,Organic layer ,law.invention ,Pentacene ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Thin-film transistor ,law ,Electrode ,Ferrite (magnet) ,Optoelectronics ,business - Abstract
The aim of this work is to select the proper electrode materials for organic thin film transistors (OTFT). The electrodes are crucial both for Pentacene-OTFT or transistors with other semiconductors without toxic precursors. In this scope, the paper is developed on two directions: (i) simulation of OTFT, starting from a fabricated Pentacene transistor, able to match the simulated characteristics with the experimental characteristics and (ii) experimental tests on an organic transistor with silver electrodes for source and drain and para-amino-benzoic acid coupled to ferrite nano-core-shell as active organic layer. The experimental material is silver for electrodes. Further improvements are expected by gold and other materials with optimal workfunction.
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- 2019
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15. Application of the Nonlinear Electrical Conduction Theorem to Emphasize the Optimized Biosensor Sensitivity
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Daniela Istrati, Catalin Parvulescu, Cristian Ravariu, Elena Manea, and Dan Eduard Mihaiescu
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Analyte ,Materials science ,business.industry ,Transistor ,law.invention ,Ion ,Nonlinear system ,law ,Electrical conduction ,Electrode ,Optoelectronics ,business ,Biosensor ,Voltage - Abstract
This paper is focused on biosensors that detect catabolists and anabolists of some living cells coupled with Ion Selective Electrodes within Transistors. The global biosensor can be treated as an electronic device, which input stimulus is the analyte concentration that is converted in electric voltage or current. Because the dependence of the output reply – electrical current – versus the analyte concentration is a non-linear function on large work domain, the Nonlinear Electrical Conduction Theorem (NECT) can be applied here for the sensitivity domain optimization. Claimed in 1993 by Adrian Rusu, the NECT theorem can find the thresholds points of any non-linear device or sensor. Some experimental picked points of two bacterial biosensors reported in the bioscience literature were analyzed in this paper by NECT. A suitable model that obeys to the Non – Linear Electrical Conduction Theorem is developed.
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- 2019
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16. Phyto-mediated nanostructured carriers based on dual vegetable actives involved in the prevention of cellular damage
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Ovidiu Oprea, Ioana Lacatusu, Laura Mihaela Stefan, Aurelia Meghea, Daniela Istrati, Nicoleta Badea, Raluca Stan, N. Bordei, and Gabriela Badea
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0301 basic medicine ,Materials science ,Antioxidant ,medicine.medical_treatment ,Anti-Inflammatory Agents ,Bioengineering ,02 engineering and technology ,medicine.disease_cause ,Antioxidants ,Biomaterials ,Mice ,03 medical and health sciences ,Cell Line, Tumor ,Hippophae ,medicine ,Animals ,Humans ,Viability assay ,Particle Size ,Carotenoid ,Safflower Oil ,Sea buckthorn oil ,chemistry.chemical_classification ,Drug Carriers ,Plant Extracts ,021001 nanoscience & nanotechnology ,Daucus carota ,Nanostructures ,030104 developmental biology ,Vegetable oil ,chemistry ,Biochemistry ,Mechanics of Materials ,Nanocarriers ,0210 nano-technology ,Drug carrier ,Oxidative stress - Abstract
The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to -45mV) and displayed average sizes of 70nm to 140nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract-bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α.
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- 2016
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17. Synergism of plant extract and vegetable oils-based lipid nanocarriers: Emerging trends in development of advanced cosmetic prototype products
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L.M. Panteli, Daniela Istrati, Nicoleta Badea, A.M. Seciu, M. Popescu, N. Bordei, and Ioana Lacatusu
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Male ,Luminescence ,Antioxidant ,Azelaic acid ,Materials science ,Biocompatibility ,medicine.medical_treatment ,Lipid nanocarriers ,Enzyme-Linked Immunosorbent Assay ,Bioengineering ,Cosmetics ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Cell Line ,Biomaterials ,In vivo ,medicine ,Animals ,Humans ,Plant Oils ,Food science ,Carotenoid ,Skin ,chemistry.chemical_classification ,Plant Extracts ,Hydrogels ,021001 nanoscience & nanotechnology ,Lipids ,In vitro ,Nanostructures ,Rats ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,0210 nano-technology ,Cosmetic industry ,medicine.drug - Abstract
Phytochemicals are priceless sources of bioactive compounds with multiple health benefices. The main objective of the current investigation was to develop nanostructured herbal formulations conditioned as appropriate hydrogel (HG) conferring an enhanced transdermal absorption of bioactive compounds from selective extracts and vegetable oils. The direct impact of research is represented by the identification of prototype products which manifest an improved therapeutic response, by means of cumulative antioxidant, anti-inflammatory and anti-acne actions, without causing any side health effects. The combinatorial effect of Carrot Extract (CE) and Marigold Extract (ME) – Nanostructured Lipid Carriers (NLC) based on rosehip oil or black cumin oils was accompanied by a high biocompatibility and a significant ability to capture both short- and long-life free radicals. HG-NLC-ME-CE has been shown to be an efficient carrier with a differentiated potential for in vitro release of the two active principles, e.g. it delayed the release of carotenoids while the hydrophilic active (azelaic acid, AA) was faster released. The HG-NLC efficacy in skin inflammation treatment (demonstrated by in vitro and in vivo tests) revealed a reduced expression of inflammatory cytokines (IL-1β and TNF-α), more pronounced in the case of TNF-α. Moreover, a superior in vivo anti-inflammatory effect of HG-based NLC-CE/ME-AA as compared to that obtained for a commercial product was detected, i.e. after 3 h of HG-NLC treatment, a significant reduction of rat paw edema was quantified. In pre-clinical studies, the quantification of the hydration and elasticity effects in the viable epidermis provided the evidence of the high potential of developed prototypes, suitable for implementation in the market area. The degree of skin hydration and skin elasticity were remarkable enhanced after topical application of developed prototypes, a hydration effect up to 74% being determined and a skin elasticity reaching 90%. The knowledge acquired from this investigation could be utilized by the cosmetic industry to design novel topical products with improved quality and health benefices, endowed with antioxidant, anti-inflammatory and anti-acne actions and with desired hydration and elasticity profiles, in order to achieve better therapeutic efficacy and no drug toxicity.
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- 2020
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18. From Pentacene Thin Film Transistor to Nanostructured Materials Synthesis for Green Organic-TFT
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Maria Stanca, Daniela Istrati, Cristian Ravariu, and Dan Eduard Mihalcscu
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0301 basic medicine ,chemistry.chemical_classification ,Materials science ,business.industry ,Nanoparticle ,02 engineering and technology ,Polymer ,021001 nanoscience & nanotechnology ,Thermal conduction ,Characterization (materials science) ,Nanomaterials ,Pentacene ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Thin-film transistor ,Logic gate ,Optoelectronics ,0210 nano-technology ,business - Abstract
As first aim, a start Pentacene-Organic Thin Film Transistor - OTFT - is simulated to capture the static characteristics and to find the matching parameters with the experimental set-up. The current vectors validate the main conduction way and the OTFT functionality. In a second stage, the basic technology of an alternative polymer grafted on nanomaterial synthesis, is depicted. The Fe304 core-shell nanoparticles are assembled by an external shell of paraaminobenzoic acid (PABA). The final scope will be OTFT construction by these green technologies. The first step: the Fe 3 O 4 /PAbathin films synthesis and characterization, is successfully performed.
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- 2018
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19. Nano-Core-Shell Technologies Suitable for Thin Film Transistors Implementation
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Daniela Istrati, Cristian Ravariu, Bogdan Pureareanu, and Dan Eduard Mihaieseu
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Materials science ,Fabrication ,Silicon ,business.industry ,Transistor ,chemistry.chemical_element ,Nanomaterials ,law.invention ,chemistry ,Thin-film transistor ,law ,Nano ,Zeta potential ,Optoelectronics ,Ferrite (magnet) ,business - Abstract
This paper presents a novel type of technology involved in the Thin Film Transistors (TFT) fabrication, using ferrite-Nano-Core-Shell-multilayer (NCS) materials. In a first stage, the applied technology of the nanomaterial synthesis is depicted. Primary core-shell np's ferrite nano-particles (Fe304) is processed by self-assembling of an external shell with organic compound (PABA - para-aminobenzoic acid). Dynamic Light Scattering characterization reveals a hydrodynamic width of 70.9nm and a high zeta potential of 51.6 mV, indicating high stability of the technology. The material applications in TFT is in progress. Therefore, some Atlas simulations capture the static characteristics and superior performances for transistor with nano-core-shell material. Either NCS or Poly-Silicon, the current vectors flow thru a TFT device proves the main conduction way and the device functionality.
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- 2018
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20. High temperature superconducting materials based on Graphene / YBCO nanocomposite
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Bogdan Stefan Vasile, Dan Eduard Mihaiescu, Anton Ficai, Daniela Istrati, Roxana Trusca, Maria Colie, Ecaterina Andronescu, Carmen Plapcianu, and Adrian Surdu
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Materials science ,Nanocomposite ,Graphene ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,Yttrium ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,symbols.namesake ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,0103 physical sciences ,symbols ,Graphite ,Composite material ,010306 general physics ,0210 nano-technology ,Raman spectroscopy ,Graphene nanoribbons ,Graphene oxide paper - Abstract
New route synthesis of YBCO / graphene composite material is described in the present work. The oxide mixture and graphene were obtained separately and then mixed together by ball milling in the mass ratio graphene: YBCO = 1: 100. The oxide mixture was prepared by modified auto combustion reaction starting from stoichiometric amounts of yttrium acetate and barium and copper nitrates without any other organic compound addition. Graphene materials were prepared by reducing GO (i.e. oxidation of graphite powder by a modified Hummers method) with hidrazine sulphate. The final material resulted by applying the ball-milling method was investigated by XRD, SEM, Raman and HRTEM.
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- 2016
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21. Exploitation of amaranth oil fractions enriched in squalene for dual delivery of hydrophilic and lipophilic actives
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Aurelia Meghea, Gabriela Badea, Narcisa Babeanu, Cristina Ott, Iulia Adriana Grafu, Nicoleta Badea, Ioana Lacatusu, Daniela Istrati, and Raluca Stan
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Drug ,Chromatography ,Antioxidant ,media_common.quotation_subject ,medicine.medical_treatment ,Amaranth ,Amaranth oil ,Squalene ,chemistry.chemical_compound ,Hesperidin ,Biochemistry ,chemistry ,Lipophilicity ,medicine ,Nanocarriers ,Agronomy and Crop Science ,media_common - Abstract
The study describes an ideal approach to increase the co-encapsulation of two water and lipid-soluble drugs in the same delivery system. The main purpose is represented by the exploitation of oil fractions isolated from amaranth seeds for the development of squalene-based nanocarriers able for a dual release of one antitumor drug, pemetrexed and one bio-flavonoid, hesperidin. The co-encapsulated nanocarriers presented unique nanoassembly morphology and showed excellent stability against aggregation. A delimited repartition of both actives, mainly in oily nanoconfinements of lipid nanocariers has been indicated by scanning calorimetry. The entrapment efficiency study revealed a great encapsulation effect with values reaching 94% for hesperidin and 89% for pemetrexed. These values are associated with a high ability of squalene-nanocarriers to capture free radicals. The greatest antioxidant activity was determined for nanocarriers that co-encapsulate 1.4% drugs, e.g., 97.3 and 98.2%. In vitro co-release tests demonstrated that pemetrexed and hesperidin were gradually released despite of their different lipophilicity. The most concentrated squalene fraction assures a slower release of both actives. The cumulative results showed that the applied strategy is a promising approach to improve the performance of medical treatments used to prevent and treat diseases associated with tumor and oxidative stress.
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- 2015
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22. Impact of Spices and Wine-Based Marinades on Tenderness, Fragmentation of Myofibrillar Proteins and Color Stability in Bovine B iceps Femoris Muscle
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Aurelia Ionescu, Ana-Maria Simion Ciuciu, Camelia Vizireanu, Javier Carballo, and Daniela Istrati
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Wine ,Seasoning ,biology ,Chemistry ,Thymus vulgaris ,food and beverages ,Pharmaceutical Science ,Marination ,biology.organism_classification ,Allium sativum ,Tenderness ,Meat tenderness ,Metmyoglobin ,medicine ,Food science ,medicine.symptom ,Food Science - Abstract
Fresh beef slices were marinated by immersion in marinades based on dry red wine, lime-tree honey, salt, spices and seasoning plants such as thyme (Thymus vulgaris), marjoram (Majorana hortensis), garlic (Allium sativum) and horseradish (Armoracia rusticana). Once marinated, meat pieces were vacuum packed and stored at 4C for 12 days. Experimental data indicated that marination of bovine Biceps femoris muscle in wine-based marinades with spices and seasoning plants addition significantly decreased (P 0.05) on L*, a* and b* but significant on Mb (myoglobin), MMb (metmyoglobin) and MbO2 (oxymyoglobin) percentages. Electrophoretic pattern of muscle proteins showed reduction of molecular weight and relative density (%) of some protein fractions for marinated samples compared with the control. Practical Applications Meat quality can be defined as a combination of sensory characteristics and technological aspects, such as color, water-holding capacity, cooking losses and texture. Marinades based on dry red wine, lime-tree honey, salt, spices and seasoning plants might be used as a marinating agent for improving the tenderness of tough meat and decreasing cooking losses with no effect on meat color. It can be easily applied at household and industrial levels as an easy technique to improve meat tenderness. Improvement in tenderness will be of great value to both consumers and meat processors.
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- 2015
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23. Using PPM for Health Related Text Detection
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Victoria Bobicev, Daniela Istrati, and Victoria Lazu
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Social media mining ,business.industry ,Computer science ,Internet privacy ,Health related ,Social media ,Text detection ,business - Abstract
This paper describes the participation of the LILU team in SMM4H challenge on social media mining for health related events description such as drug intakes or vaccinations.
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- 2018
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24. Flash Vacuum Pyrolysis of 2,5-Diphenyloxazole
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Daniela Istrati, Mircea D. Banciu, Constantin Draghici, and Dan Eduard Mihaiescu
- Subjects
radical reactions ,Flash vacuum pyrolysis ,Chemistry ,Organic Chemistry ,Pharmaceutical Science ,Flash-vacuum pyrolysis ,Analytical Chemistry ,lcsh:QD241-441 ,carbenes ,chemistry.chemical_compound ,lcsh:Organic chemistry ,Chemistry (miscellaneous) ,Drug Discovery ,Molecular Medicine ,Organic chemistry ,Physical and Theoretical Chemistry ,5-diphenyloxazole ,Oxazole - Abstract
FVP of the title oxazole (1) at 1000oC and 0.5 mm Hg afforded a complex reaction mixture containing benzonitrile, phenylacetonitrile, biphenyl, diphenylmethane, fluorene, o-benzylbenzonitrile (major product, 22%), phenanthrene, anthracene, 9,10-anthraquinone, 2-phenylindole and 3-phenylindole. A radical and carbene mechanism was suggested in order to rationalize the formation of the reaction products.
- Published
- 2000
- Full Text
- View/download PDF
25. Physico-chemical, antioxidant activity and sensory analysis of new beverages based on milk, cranberry, rosehip fruits and horseradish
- Author
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Felicia Dima, Camelia Vizireanu, Daniela Istrati, Cristina Pavalasc, E. Pricop, and R. M. Burluc
- Subjects
Antioxidant ,Chemistry ,medicine.medical_treatment ,medicine ,Bioengineering ,General Medicine ,Food science ,Applied Microbiology and Biotechnology ,Sensory analysis ,Biotechnology - Published
- 2015
- Full Text
- View/download PDF
26. Reaction of Pyrylium Salts with Nucleophiles. Part 24.New Mono- and Bispyridinium Salts with a Central 2,5-Diaryloxazole Group
- Author
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Alexandru T. Balaban, Daniela Istrati, Calin Deleanu, Iosif Schiketanz, and Constantin Draghici
- Subjects
chemistry.chemical_compound ,Nucleophile ,Chemistry ,Aryl ,Hydrazine ,Nitro ,Proton NMR ,General Chemistry ,Carbon-13 NMR ,Hydrate ,Medicinal chemistry ,Raney nickel - Abstract
Reduction of nitro substituted 2,5-diaryloxazoles with hydrazine hydrate and Raney nickel affords in good yield 2,5-diaryloxazoles having amino group(s) on the aryl ring(s) . The reaction of 2,4,6-trisubstituted pyrylium perchlorates with mono- and diamino-2,5-diaryloxazoles yields new mono- and bispyridinium perchlorates with a central 2,5-diaryloxazole group. Their electronic, 13C NMR and 1H NMR spectra are presented and discussed.
- Published
- 1997
- Full Text
- View/download PDF
27. Fe3O4/Salicylic acid nanoparticles behavior on chick CAM vasculature
- Author
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Ion Mîndrilă, Daniela Istrati, Dan Eduard Mihaiescu, Alice Sandra Buteica, and Johny Neamţu
- Subjects
Materials science ,Biocompatibility ,Analytical chemistry ,Nanoparticle ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,chemistry.chemical_compound ,chemistry ,Transmission electron microscopy ,Modeling and Simulation ,Zeta potential ,Biophysics ,Magnetic nanoparticles ,Ferrite (magnet) ,General Materials Science ,Iron oxide nanoparticles ,Salicylic acid - Abstract
A modified ferrite co-precipitation synthesis was used to obtain core–shell Fe3O4/salicylic acid magnetic nanoparticles (Sa-MNP) with well-dispersed aqueous solution properties. The newly developed iron oxide nanoparticles properties were investigated with X-ray diffraction, Fourier transform infrared spectrometry, transmission electron microscopy, and laser light scattering for their characteristic establishment. The resulting Sa-MNPs have spherical morphology, homogenous size distribution around 60 nm (35 nm FWHM), and a 67 mV Zeta potential value (15.5 mV STDV). In vivo biocompatibility and intravascular behavior of the 60 nm diameter size range synthesized nanoparticles were evaluated on chick chorioallantoic membrane model. The results show a reversible and good controlled intravascular accumulation under static magnetic field, a low risk of embolisation with nanoparticle aggregates detached from venous intravascular nanoblocked areas, a persistent blocking of the arterioles and dependent capillaries network, a good circulating life time and biocompatibility. The beneficial effects of salicylic acid (SA) and in vivo demonstrated capacity of Sa-MNPs to cutoff regional vascular supply under static magnetic field control suggest a possible biomedical application of these MNPs in targeted cancer therapy through magnetic controlled blood flow nanoblocking mechanism.
- Published
- 2013
- Full Text
- View/download PDF
28. ChemInform Abstract: Flow-Vacuum Pyrolysis of Polycyclic Compounds. Part 27. Pyrolysis of 8,9-Dihydro-14H-tetrazolo[1,5-a]dibenzo[c,f]azonine and 6,7,8,9-Tetrahydro-tetrazolo[1,5-a]benzo[c]azocine
- Author
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Angela Popescu, Elena Andrei, Daniela Istrati, Constantin Draghici, Crinu Ciuculescu, and Mircea D. Banciu
- Subjects
chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Organic chemistry ,Azocine ,Tetrazole ,General Medicine ,Pyrolysis - Abstract
Flow-vacuum pyrolysis of the title fused tetrazole derivatives (II) and (V), resp., provides stable N-cyanoheterocycles in good yield.
- Published
- 2010
- Full Text
- View/download PDF
29. ChemInform Abstract: Reaction of Pyrylium Salts with Nucleophiles. Part 24. New Mono- and Bispyridinium Salts with a Central 2,5-Diaryloxazole Group
- Author
-
Daniela Istrati, Constantin Draghici, Iosif Schiketanz, Alexandru T. Balaban, and Calin Deleanu
- Subjects
chemistry.chemical_compound ,chemistry ,Nucleophile ,Aryl ,Hydrazine ,Nitro ,Proton NMR ,Organic chemistry ,General Medicine ,Carbon-13 NMR ,Hydrate ,Medicinal chemistry ,Raney nickel - Abstract
Reduction of nitro substituted 2,5-diaryloxazoles with hydrazine hydrate and Raney nickel affords in good yield 2,5-diaryloxazoles having amino group(s) on the aryl ring(s) . The reaction of 2,4,6-trisubstituted pyrylium perchlorates with mono- and diamino-2,5-diaryloxazoles yields new mono- and bispyridinium perchlorates with a central 2,5-diaryloxazole group. Their electronic, 13 C NMR and 1 H NMR spectra are presented and discussed.
- Published
- 2010
- Full Text
- View/download PDF
30. ChemInform Abstract: Aminoketone, Oxazole and Thiazole Synthesis. Part 13. New 2-Aryl-6-phenyloxazoles with 4-Methyl or 4-Isopropyl Groups
- Author
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Constantin Draghici, Iosif Schiketanz, Alexandru T. Balaban, and Daniela Istrati
- Subjects
chemistry.chemical_compound ,Thiazole synthesis ,chemistry ,medicine.drug_class ,Aryl ,medicine ,Organic chemistry ,General Medicine ,Combinatorial chemistry ,Isopropyl ,Oxazole ,Aminoketone - Published
- 2010
- Full Text
- View/download PDF
31. Epoxidation of Polycyclic Hydrocarbons. Part 1
- Author
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Constantin Draghici, Mircea D. Banciu, George Marton, Daniela Istrati, and Luminitza Parvulescu
- Subjects
Chemistry ,Stereochemistry ,Organic chemistry ,Polycyclic Hydrocarbons ,General Medicine - Published
- 2007
- Full Text
- View/download PDF
32. Optimisation of growth condition for 'Bacillus licheniformis' and 'Bacillus subtilis' by using xylooligosaccharides
- Author
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Daniela Istrati, Camelia Vizireanu, Cristian-Teodor Buruiana, and Oana Emilia Constantin
- Subjects
biology ,Chemistry ,Bioengineering ,General Medicine ,Bacillus subtilis ,Bacillus licheniformis ,Food science ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biotechnology - Published
- 2015
- Full Text
- View/download PDF
33. Rheological and textural properties of different formulations for functional rice based biscuits
- Author
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Flicia Dima, E. Pricop, R. M. Burluc, Daniela Istrati, and Camelia Vizireanu
- Subjects
Materials science ,Rheology ,Bioengineering ,General Medicine ,Composite material ,Applied Microbiology and Biotechnology ,Biotechnology - Published
- 2015
- Full Text
- View/download PDF
34. Influence of unconventional thermal treatment on physico-chemical characteristics of vegetable juices
- Author
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E. Pricop, Valentina Serea, Daniela Istrati, R. M. Burluc, Camelia Vizireanu, and Felicia Dima
- Subjects
Chemistry ,Bioengineering ,General Medicine ,Food science ,Thermal treatment ,Vegetable Juices ,Applied Microbiology and Biotechnology ,Biotechnology - Published
- 2015
- Full Text
- View/download PDF
35. Rheologic behavior of pastry creams
- Author
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Vizireanu, C., Ionescu, A., Daniela Istrati, and Dima, F.
- Subjects
rheologic behavior ,viscoelastic properties ,traditional creams ,lcsh:TP1-1185 ,instant creams ,lcsh:Chemical technology - Abstract
The increased social and economic importance of ready–made food production, together with the complexity of production technology, processing, handling and acceptance of these fragile and perishable products requires extensive knowledge of their physical properties. Viscoelastic properties play an important role in the handling and quality attributes of creams.Our study was to investigate the rheological properties of different confectionary creams, by scanning the field of shear rates at constant temperature and frequency, angular frequency scanning at small deformations and quantification of rheological changes during application of deformation voltages. The creams tested were made in the laboratory using specific concentrates as fine powders, marketed by the company “Dr. Oetker” compared with similar creams based on traditional recipes and techniques. Following the researches conducted we could conclude that both traditional creams and the instant ones are semi fluid food products with pseudoplastic and thixotropic shear flow behavior, with structural viscosity. Instant and traditional creams behaved as physical gels with links susceptible to destruction, when subjected to deformation forces.
36. Rheological and sensory characterisation of gels obtained from vegetal origin hydrocolloids
- Author
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Vizireanu, C., Ionescu, A., Daraba, A., Daniela Istrati, and Burluc, R.
37. Preserving quality of frozen green peas during long time storage | Préserver la qualité des petits pois verts surgelés pendant l'entreposage
- Author
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Dima, F., Vizireanu, C., and Daniela Istrati
38. The tenderization of bovine Biceps femoris muscle using marinades on the basis of wine
- Author
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Daniela Istrati, Ionescu, A., Vizireanu, C., Ciuciu, A. M. S., and Dinicǎ, R.
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