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Dr. Gheorghe Nechifor
Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania

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0 Environmental Chemistry
0 Environmental Engineering
0 Environmental quality control
0 Membrane and membrane processes
0 Decontaminations techniques

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Journal article
Published: 17 August 2021 in Membranes
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Membranes are associated with the efficient processes of separation, concentration and purification, but a very important aspect of them is the realization of a reaction process simultaneously with the separation process. From a practical point of view, chemical reactions have been introduced in most membrane systems: with on-liquid membranes, with inorganic membranes or with polymeric and/or composite membranes. This paper presents the obtaining of polymeric membranes containing metallic osmium obtained in situ. Cellulose acetate (CA), polysulfone (PSf) and polypropylene hollow fiber membranes (PPM) were used as support polymer membranes. The metallic osmium is obtained directly onto the considered membranes using a solution of osmium tetroxide (OsO4), dissolved in tert–butyl alcohol (t–Bu–OH) by reduction with molecular hydrogen. The composite osmium–polymer (Os–P)-obtained membranes were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy-dispersive spectroscopy analysis (EDAX), Fourier Transform Infra-Red (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The process performance was tested for reduction of 5–nitrobenzimidazole to 5–aminobenzimidazole with molecular hydrogen. The paper presents the main aspects of the possible mechanism of transformation of 5–nitrobenzimidazole to 5–aminobenzimidazole with hydrogen gas in the reaction system with osmium–polymer membrane (Os–P).

ACS Style

Aurelia Cristina Nechifor; Alexandru Goran; Vlad-Alexandru Grosu; Andreia Pîrțac; Paul Constantin Albu; Ovidiu Oprea; Alexandra Raluca Grosu; Dumitru Pașcu; Florentina Mihaela Păncescu; Gheorghe Nechifor; Szidonia-Katalin Tanczos; Simona Gabriela Bungău. Reactional Processes on Osmium–Polymeric Membranes for 5–Nitrobenzimidazole Reduction. Membranes 2021, 11, 633 .

AMA Style

Aurelia Cristina Nechifor, Alexandru Goran, Vlad-Alexandru Grosu, Andreia Pîrțac, Paul Constantin Albu, Ovidiu Oprea, Alexandra Raluca Grosu, Dumitru Pașcu, Florentina Mihaela Păncescu, Gheorghe Nechifor, Szidonia-Katalin Tanczos, Simona Gabriela Bungău. Reactional Processes on Osmium–Polymeric Membranes for 5–Nitrobenzimidazole Reduction. Membranes. 2021; 11 (8):633.

Chicago/Turabian Style

Aurelia Cristina Nechifor; Alexandru Goran; Vlad-Alexandru Grosu; Andreia Pîrțac; Paul Constantin Albu; Ovidiu Oprea; Alexandra Raluca Grosu; Dumitru Pașcu; Florentina Mihaela Păncescu; Gheorghe Nechifor; Szidonia-Katalin Tanczos; Simona Gabriela Bungău. 2021. "Reactional Processes on Osmium–Polymeric Membranes for 5–Nitrobenzimidazole Reduction." Membranes 11, no. 8: 633.

Erratum
Published: 03 July 2021 in Journal of Dentistry
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ACS Style

Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Gheorghe Nechifor; Hassan Y. Aboul-Enein; Corina Marilena Cristache. Corrigendum to ‘Poly(methyl methacrylate) with TiO2 nanoparticles inclusion for stereolithographic complete denture manufacturing the future in dental care for elderly edentulous patients?’ [Journal of Dentistry 59 (2017) 68–77]. Journal of Dentistry 2021, 103739 .

AMA Style

Eugenia Eftimie Totu, Aurelia Cristina Nechifor, Gheorghe Nechifor, Hassan Y. Aboul-Enein, Corina Marilena Cristache. Corrigendum to ‘Poly(methyl methacrylate) with TiO2 nanoparticles inclusion for stereolithographic complete denture manufacturing the future in dental care for elderly edentulous patients?’ [Journal of Dentistry 59 (2017) 68–77]. Journal of Dentistry. 2021; ():103739.

Chicago/Turabian Style

Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Gheorghe Nechifor; Hassan Y. Aboul-Enein; Corina Marilena Cristache. 2021. "Corrigendum to ‘Poly(methyl methacrylate) with TiO2 nanoparticles inclusion for stereolithographic complete denture manufacturing the future in dental care for elderly edentulous patients?’ [Journal of Dentistry 59 (2017) 68–77]." Journal of Dentistry , no. : 103739.

Journal article
Published: 15 June 2021 in Membranes
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The membranes and membrane processes have succeeded in the transition from major technological and biomedical applications to domestic applications: water recycling in washing machines, recycling of used cooking oil, recovery of gasoline vapors in the pumping stations or enrichment of air with oxygen. In this paper, the neutralization of condensation water and the retention of aluminum from thermal power plants is studied using ethylene propylene diene monomer sulfonated (EPDM-S) membranes containing magnetic particles impregnated in a microporous propylene hollow fiber (I-PPM) matrix. The obtained membranes were characterized from the morphological and structural points of view, using scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX) and thermal gravimetric analyzer. The process performances (flow, selectivity) were studied using a variable magnetic field generated by electric coils. The results show the possibility of correcting the pH and removing aluminum ions from the condensation water of heating plants, during a winter period, without the intervention of any operator for the maintenance of the process. The pH was raised from an acidic one (2–4), to a slightly basic one (8–8.5), and the concentration of aluminum ions was lowered to the level allowed for discharge. Magnetic convection of the permeation module improves the pH correction process, but especially prevents the deposition of aluminum hydroxide on hollow fibers membranes.

ACS Style

Aurelia Nechifor; Alexandru Goran; Vlad-Alexandru Grosu; Constantin Bungău; Paul Albu; Alexandra Grosu; Ovidiu Oprea; Florentina Păncescu; Gheorghe Nechifor. Improving the Performance of Composite Hollow Fiber Membranes with Magnetic Field Generated Convection Application on pH Correction. Membranes 2021, 11, 445 .

AMA Style

Aurelia Nechifor, Alexandru Goran, Vlad-Alexandru Grosu, Constantin Bungău, Paul Albu, Alexandra Grosu, Ovidiu Oprea, Florentina Păncescu, Gheorghe Nechifor. Improving the Performance of Composite Hollow Fiber Membranes with Magnetic Field Generated Convection Application on pH Correction. Membranes. 2021; 11 (6):445.

Chicago/Turabian Style

Aurelia Nechifor; Alexandru Goran; Vlad-Alexandru Grosu; Constantin Bungău; Paul Albu; Alexandra Grosu; Ovidiu Oprea; Florentina Păncescu; Gheorghe Nechifor. 2021. "Improving the Performance of Composite Hollow Fiber Membranes with Magnetic Field Generated Convection Application on pH Correction." Membranes 11, no. 6: 445.

Journal article
Published: 05 June 2021 in Membranes
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The separation, concentration and transport of the amino acids through membranes have been continuously developed due to the multitude of interest amino acids of interest and the sources from which they must be recovered. At the same time, the types of membranes used in the sepa-ration of the amino acids are the most diverse: liquids, ion exchangers, inorganic, polymeric or composites. This paper addresses the recuperative separation of three amino acids (alanine, phe-nylalanine, and methionine) using membranes from cellulosic derivatives in polypropylene ma-trix. The microfiltration membranes (polypropylene hollow fibers) were impregnated with solu-tions of some cellulosic derivatives: cellulose acetate, 2-hydroxyethyl-cellulose, methyl 2-hydroxyethyl-celluloseand sodium carboxymethyl-cellulose. The obtained membranes were characterized in terms of the separation performance of the amino acids considered (retention, flux, and selectivity) and from a morphological and structural point of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and thermal gravimetric analyzer (TGA). The re-sults obtained show that phenylalanine has the highest fluxes through all four types of mem-branes, followed by methionine and alanine. Of the four kinds of membrane, the most suitable for recuperative separation of the considered amino acids are those based on cellulose acetate and methyl 2-hydroxyethyl-cellulose.

ACS Style

Aurelia Nechifor; Andreia Pîrțac; Paul Albu; Alexandra Grosu; Florina Dumitru; Ioana Dimulescu (Nica); Ovidiu Oprea; Dumitru Pașcu; Gheorghe Nechifor; Simona Bungău. Recuperative Amino Acids Separation through Cellulose Derivative Membranes with Microporous Polypropylene Fiber Matrix. Membranes 2021, 11, 429 .

AMA Style

Aurelia Nechifor, Andreia Pîrțac, Paul Albu, Alexandra Grosu, Florina Dumitru, Ioana Dimulescu (Nica), Ovidiu Oprea, Dumitru Pașcu, Gheorghe Nechifor, Simona Bungău. Recuperative Amino Acids Separation through Cellulose Derivative Membranes with Microporous Polypropylene Fiber Matrix. Membranes. 2021; 11 (6):429.

Chicago/Turabian Style

Aurelia Nechifor; Andreia Pîrțac; Paul Albu; Alexandra Grosu; Florina Dumitru; Ioana Dimulescu (Nica); Ovidiu Oprea; Dumitru Pașcu; Gheorghe Nechifor; Simona Bungău. 2021. "Recuperative Amino Acids Separation through Cellulose Derivative Membranes with Microporous Polypropylene Fiber Matrix." Membranes 11, no. 6: 429.

Journal article
Published: 01 May 2021 in Nanomaterials
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The present study introduces the process performances of nitrophenols pertraction using new liquid supported membranes under the action of a magnetic field. The membrane system is based on the dispersion of silver–iron oxide nanoparticles in n-alcohols supported on hollow microporous polypropylene fibers. The iron oxide–silver nanoparticles are obtained directly through cyclic voltammetry electrolysis run in the presence of soluble silver complexes ([AgCl2]; [Ag(S2O3)2]3−; [Ag(NH3)2]+) and using pure iron electrodes. The nanostructured particles are characterized morphologically and structurally by scanning electron microscopy (SEM and HFSEM), EDAX, XRD, and thermal analysis (TG, DSC). The performances of the nitrophenols permeation process are investigated in a variable magnetic field. These studies show that the flux and extraction efficiency have the highest values for the membrane system embedding iron oxide–silver nanoparticles obtained electrochemically in the presence of [Ag(NH3)2]+ electrolyte. It is demonstrated that the total flow of nitrophenols through the new membrane system depends on diffusion, convection, and silver-assisted transport.

ACS Style

Ioana Dimulescu (Nica); Aurelia Nechifor; Cristina Bǎrdacǎ (Urducea); Ovidiu Oprea; Dumitru Paşcu; Eugenia Totu; Paul Albu; Gheorghe Nechifor; Simona Bungău. Accessible Silver-Iron Oxide Nanoparticles as a Nanomaterial for Supported Liquid Membranes. Nanomaterials 2021, 11, 1204 .

AMA Style

Ioana Dimulescu (Nica), Aurelia Nechifor, Cristina Bǎrdacǎ (Urducea), Ovidiu Oprea, Dumitru Paşcu, Eugenia Totu, Paul Albu, Gheorghe Nechifor, Simona Bungău. Accessible Silver-Iron Oxide Nanoparticles as a Nanomaterial for Supported Liquid Membranes. Nanomaterials. 2021; 11 (5):1204.

Chicago/Turabian Style

Ioana Dimulescu (Nica); Aurelia Nechifor; Cristina Bǎrdacǎ (Urducea); Ovidiu Oprea; Dumitru Paşcu; Eugenia Totu; Paul Albu; Gheorghe Nechifor; Simona Bungău. 2021. "Accessible Silver-Iron Oxide Nanoparticles as a Nanomaterial for Supported Liquid Membranes." Nanomaterials 11, no. 5: 1204.

Journal article
Published: 01 April 2021 in Membranes
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The unpleasant odor that appears in the industrial and adjacent waste processing areas is a permanent concern for the protection of the environment and, especially, for the quality of life. Among the many variants for removing substance traces, which give an unpleasant smell to the air, membrane-based methods or techniques are viable options. Their advantages consist of installation simplicity and scaling possibility, selectivity; moreover, the flows of odorous substances are direct, automation is complete by accessible operating parameters (pH, temperature, ionic strength), and the operation costs are low. The paper presents the process of obtaining membranes from cellulosic derivatives containing silver nanoparticles, using accessible raw materials (namely motion picture films from abandoned archives). The technique used for membrane preparation was the immersion precipitation for phase inversion of cellulosic polymer solutions in methylene chloride: methanol, 2:1 volume. The membranes obtained were morphologically and structurally characterized by scanning electron microscopy (SEM) and high resolution SEM (HR SEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectrometry (FTIR), thermal analysis (TG, ATD). Then, the membrane performance process (extraction efficiency and species flux) was determined using hydrogen sulfide (H2S) and ethanethiol (C2H5SH) as target substances.

ACS Style

Aurelia Nechifor; Simona Cotorcea; Constantin Bungău; Paul Albu; Dumitru Pașcu; Ovidiu Oprea; Alexandra Grosu; Andreia Pîrțac; Gheorghe Nechifor. Removing of the Sulfur Compounds by Impregnated Polypropylene Fibers with Silver Nanoparticles-Cellulose Derivatives for Air Odor Correction. Membranes 2021, 11, 256 .

AMA Style

Aurelia Nechifor, Simona Cotorcea, Constantin Bungău, Paul Albu, Dumitru Pașcu, Ovidiu Oprea, Alexandra Grosu, Andreia Pîrțac, Gheorghe Nechifor. Removing of the Sulfur Compounds by Impregnated Polypropylene Fibers with Silver Nanoparticles-Cellulose Derivatives for Air Odor Correction. Membranes. 2021; 11 (4):256.

Chicago/Turabian Style

Aurelia Nechifor; Simona Cotorcea; Constantin Bungău; Paul Albu; Dumitru Pașcu; Ovidiu Oprea; Alexandra Grosu; Andreia Pîrțac; Gheorghe Nechifor. 2021. "Removing of the Sulfur Compounds by Impregnated Polypropylene Fibers with Silver Nanoparticles-Cellulose Derivatives for Air Odor Correction." Membranes 11, no. 4: 256.

Journal article
Published: 21 January 2021 in Membranes
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In order to obtained high selective membrane for industrial applications (such as natural gas purification), mixed matrix membranes (MMMs) were developed based on polysulfone as matrix and MCM-41-type silica material (obtained from coal fly ash) as filler. As a consequence, various quantities of filler were used to determine the membranes efficiency on CO2/CH4 separation. The coal fly ash derived silica nanomaterial and the membranes were characterized in terms of thermal stability, homogeneity, and pore size distribution. There were observed similar properties of the obtained nanomaterial with a typical MCM-41 (obtained from commercial silicates), such as high surface area and pore size distribution. The permeability tests highlighted that the synthesized membranes can be applicable for CO2 removal from CH4, due to unnoticeable differences between real and ideal selectivity. Additionally, the membranes showed high resistance to CO2 plasticization, due to permeability decrease even at high feed pressure, up to 16 bar.

ACS Style

Marius Miricioiu; Violeta-Carolina Niculescu; Constantin Filote; Maria Raboaca; Gheorghe Nechifor. Coal Fly Ash Derived Silica Nanomaterial for MMMs—Application in CO2/CH4 Separation. Membranes 2021, 11, 78 .

AMA Style

Marius Miricioiu, Violeta-Carolina Niculescu, Constantin Filote, Maria Raboaca, Gheorghe Nechifor. Coal Fly Ash Derived Silica Nanomaterial for MMMs—Application in CO2/CH4 Separation. Membranes. 2021; 11 (2):78.

Chicago/Turabian Style

Marius Miricioiu; Violeta-Carolina Niculescu; Constantin Filote; Maria Raboaca; Gheorghe Nechifor. 2021. "Coal Fly Ash Derived Silica Nanomaterial for MMMs—Application in CO2/CH4 Separation." Membranes 11, no. 2: 78.

Journal article
Published: 26 November 2020 in Nanomaterials
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The preparation of membranes from polymer solutions by the phase inversion method, the immersion - precipitation technique has proved since the beginning of obtaining technological membranes the most versatile and simple possibility to create polymeric membrane nanostructures. Classically, the phase inversion technique involves four essential steps: Preparation of a polymer solution in the desired solvent, the formation of the polymer solution film on a flat support, the immersion of the film in a coagulation bath containing polymer solvents, and membrane conditioning. All phase inversion stages are important for the prepared membrane’s nanostructure and have been studied in detail for more than six decades. In this paper, we explored, through an electrochemical technique, the influence of the contact time with the polymer film’s environment until the introduction into the coagulation bath. The system chosen for membrane preparation is polysulfone-dimethylformamide-aqueous ethanol solution (PSf-DMF-EW). The obtained nanostructured membranes were characterized morphologically and structurally by scanning electron microscopy (SEM) and thermal analysis (TA), and in terms of process performance through water permeation and bovine serum albumin retention (BSA). The membrane characteristics were correlated with the polymeric film exposure time to the environment until the contact with the coagulation bath, following the diagram of the electrochemical parameters provided by the electrochemical technique.

ACS Style

Cristina Bărdacă Urducea; Aurelia Cristina Nechifor; Ioana Alina Dimulescu; Ovidiu Oprea; Gheorghe Nechifor; Eugenia Eftimie Totu; Ibrahim Isildak; Paul Constantin Albu; Simona Gabriela Bungău. Control of Nanostructured Polysulfone Membrane Preparation by Phase Inversion Method. Nanomaterials 2020, 10, 2349 .

AMA Style

Cristina Bărdacă Urducea, Aurelia Cristina Nechifor, Ioana Alina Dimulescu, Ovidiu Oprea, Gheorghe Nechifor, Eugenia Eftimie Totu, Ibrahim Isildak, Paul Constantin Albu, Simona Gabriela Bungău. Control of Nanostructured Polysulfone Membrane Preparation by Phase Inversion Method. Nanomaterials. 2020; 10 (12):2349.

Chicago/Turabian Style

Cristina Bărdacă Urducea; Aurelia Cristina Nechifor; Ioana Alina Dimulescu; Ovidiu Oprea; Gheorghe Nechifor; Eugenia Eftimie Totu; Ibrahim Isildak; Paul Constantin Albu; Simona Gabriela Bungău. 2020. "Control of Nanostructured Polysulfone Membrane Preparation by Phase Inversion Method." Nanomaterials 10, no. 12: 2349.

Proceedings
Published: 14 November 2020 in Chemistry Proceedings
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Confocal laser scanning microscopy (CSLM) is a powerful microscopic tool that gives valuable morphological and functional information within cells and tissues. CLSM is non-invasive, with high-contrast scanning, a simple and fast sample preparation procedure as well as easy operation. This paper aimed to study the intracellular uptake of polymeric nanoparticles loaded with cardiovascular drugs using confocal laser scanning microscopy. Polymeric nanoparticles were prepared via nanoprecipitation method using poly(lactide-co-glycolide) (PLGA) as a biodegradable polymeric matrix and Pluronic F127 as a stabilizer. A mixture of two cardiovascular drugs—valsartan (an angiotensin II receptor antagonist drug) and amlodipine besylate (a calcium channel blocker)—was loaded in polymeric nanoparticles. The prepared polymeric nanoparticles had sizes lower than 300 nm and narrow dispersity. The cellular uptake of polymeric nanoparticles was investigated by incubating adherent mouse embryo fibroblasts (NIH 3T3) with a suspension of nanoparticles (stained previously with phthalocyanine) at three different time points. Targeted cell compartments were labeled with two fluorophores: Rhodamine B (membrane stain) and Hoechst (nucleic acid stain). Live cell imaging was performed using a confocal microscope Zeiss LSM710 with Zeiss PALM microdissection system. The intracellular uptake of polymeric nanoparticles was revealed by confocal laser scanning microscopy for each incubation time. The results suggest a possible mechanism of endocytosis and clearly a vesicular-based accumulation of the nanoparticles in the cytoplasmatic compartments.

ACS Style

Ramona-Daniela Pavaloiu; Fawzia Sha’At; Mousa Sha’At; Gheorghe Nechifor. Intracellular Uptake Study of Polymeric Nanoparticles Loaded with Cardiovascular Drugs Using Confocal Laser Scanning Microscopy. Chemistry Proceedings 2020, 3, 140 .

AMA Style

Ramona-Daniela Pavaloiu, Fawzia Sha’At, Mousa Sha’At, Gheorghe Nechifor. Intracellular Uptake Study of Polymeric Nanoparticles Loaded with Cardiovascular Drugs Using Confocal Laser Scanning Microscopy. Chemistry Proceedings. 2020; 3 (1):140.

Chicago/Turabian Style

Ramona-Daniela Pavaloiu; Fawzia Sha’At; Mousa Sha’At; Gheorghe Nechifor. 2020. "Intracellular Uptake Study of Polymeric Nanoparticles Loaded with Cardiovascular Drugs Using Confocal Laser Scanning Microscopy." Chemistry Proceedings 3, no. 1: 140.

Extended abstract
Published: 13 November 2020 in Proceedings
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An interesting and unpredictable environmental issue raises condensing plants.

ACS Style

Anca -Maria Cimbru; Aurelia Cristina Nechifor; Paul Constantin Albu; Gheorghe Nechifor. Neutralization with Simultaneous Separation of Metallic Ions from Condensed Water Through Capillary Polypropylene and Cellulose Derivatives. Proceedings 2020, 57, 64 .

AMA Style

Anca -Maria Cimbru, Aurelia Cristina Nechifor, Paul Constantin Albu, Gheorghe Nechifor. Neutralization with Simultaneous Separation of Metallic Ions from Condensed Water Through Capillary Polypropylene and Cellulose Derivatives. Proceedings. 2020; 57 (1):64.

Chicago/Turabian Style

Anca -Maria Cimbru; Aurelia Cristina Nechifor; Paul Constantin Albu; Gheorghe Nechifor. 2020. "Neutralization with Simultaneous Separation of Metallic Ions from Condensed Water Through Capillary Polypropylene and Cellulose Derivatives." Proceedings 57, no. 1: 64.

Extended abstract
Published: 09 November 2020 in Proceedings
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Nanomedicine is a rapidly growing field that uses nanotechnology to solve clinical problems—

ACS Style

Ramona-Daniela Pavaloiu; Fawzia Sha’At; Georgeta Neagu; Radu Albulescu; Mousa Sha’At; Cristina Hlevca; Gheorghe Nechifor; Daniela Berger. In Vitro Cytotoxicity of Polymeric Nanoparticles Coated with Lipid Layer Loaded with Cardiovascular Drugs. Proceedings 2020, 57, 9 .

AMA Style

Ramona-Daniela Pavaloiu, Fawzia Sha’At, Georgeta Neagu, Radu Albulescu, Mousa Sha’At, Cristina Hlevca, Gheorghe Nechifor, Daniela Berger. In Vitro Cytotoxicity of Polymeric Nanoparticles Coated with Lipid Layer Loaded with Cardiovascular Drugs. Proceedings. 2020; 57 (1):9.

Chicago/Turabian Style

Ramona-Daniela Pavaloiu; Fawzia Sha’At; Georgeta Neagu; Radu Albulescu; Mousa Sha’At; Cristina Hlevca; Gheorghe Nechifor; Daniela Berger. 2020. "In Vitro Cytotoxicity of Polymeric Nanoparticles Coated with Lipid Layer Loaded with Cardiovascular Drugs." Proceedings 57, no. 1: 9.

Article
Published: 13 October 2020 in Journal of Applied Polymer Science
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Tangential flow filtration of the collagen protein solutions with a molecular weight 12, 14, and 24 kDa is investigated using flat sheet membranes. The effects of tangential ultrafiltration (UF) on the permeate properties using two regenerated celluloses (RCs) and two polyethersulfone (PES) membranes with molecular weight cut‐off (MWCO) of 5 and 10 kDa are reported. The permeate and concentrate obtained in the UF experiments are characterized from a physical–chemical point of view by determining the temperature, pH, electrical conductivity, nitrogen content, and protein concentration. In addition, the experimental data are modeled using Hermia's model. The UF experiments demonstrated that permeate flux declined with increasing molecular weight of collagen at constant concentration (1%). Regardless of the molecular weight of collagen, the rejections decrease in the following order: PES 5 kDa > RC5kDa > RC10kDa > PES10kDa. In case of membrane with higher MWCO, the clogging phenomenon is mainly due to the blockage of the internal pores of the membrane than the formation of a polarization layer. Morphologies and characteristics of the membranes are characterized using scanning electron microscopy.

ACS Style

Gheorghe Batrinescu; Roxana‐Elena Scutariu; Gheorghe Nechifor; Ioana‐Alexandra Ionescu; Vasile‐Ion Iancu. Comparative analysis of the processes of collagen concentration by ultrafiltration using different types of membranes. Journal of Applied Polymer Science 2020, 138, 1 .

AMA Style

Gheorghe Batrinescu, Roxana‐Elena Scutariu, Gheorghe Nechifor, Ioana‐Alexandra Ionescu, Vasile‐Ion Iancu. Comparative analysis of the processes of collagen concentration by ultrafiltration using different types of membranes. Journal of Applied Polymer Science. 2020; 138 (12):1.

Chicago/Turabian Style

Gheorghe Batrinescu; Roxana‐Elena Scutariu; Gheorghe Nechifor; Ioana‐Alexandra Ionescu; Vasile‐Ion Iancu. 2020. "Comparative analysis of the processes of collagen concentration by ultrafiltration using different types of membranes." Journal of Applied Polymer Science 138, no. 12: 1.

Journal article
Published: 07 February 2020 in Revista de Chimie
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The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active substances, which are biorefractory, toxic or persistent. Even though anionic and non-ionic surfactants often used in commercial detergents composition are reasonably degradable under aerobic conditions and not particularly toxic at low concentrations, high concentration of surfactants influenced the activated sludge activity and are harmful for the aquatic environment. In the literature, data on the biodegradability and/or ecotoxicity of a certain type of surfactant (anionic, nonionic, cationic) are usually presented. Our study aimed to assess the biodegradability of a mixture of two types of surfactants (anionic mixed with non-ionic) and also, effects caused by their presence of elevated concentrations to the activated sludge micro-organisms, within a batch experiment. We performed a biodegradability test (according Zahn-Wellens method) on 2 synthetic solutions with high concentrations of anionic surfactant �methyl dodecylbenzene sulfonate (15-25 mg/L) and non-ionic surfactant -4-nonylphenyl-polyethylene glycol (10 mg/L). The study established different percent of biodegradability (measured by COD decrease and surfactants removal) depending on initial concentrations of anionic and nonionic surfactants in the tested solutions. High surfactants concentrations modulated the activity and morphology of activated sludge, so its degradation efficiency of the organic substrate has decreased. Surfactant solutions resulting from biodegradability experiment have been tested for toxicity to planktonic crustaceans (Daphnia magna).

ACS Style

Daniel Mitru; Gheorghe Nechifor; Stefania Gheorghe; Alina Roxana Banciu; Lucian Ionescu; Catalina Stoica; Daniela Liliana Ionica; Irina Eugenia Lucaciu. Removal and Effects of Surfactants in Activated Sludge System. Revista de Chimie 2020, 71, 100 -106.

AMA Style

Daniel Mitru, Gheorghe Nechifor, Stefania Gheorghe, Alina Roxana Banciu, Lucian Ionescu, Catalina Stoica, Daniela Liliana Ionica, Irina Eugenia Lucaciu. Removal and Effects of Surfactants in Activated Sludge System. Revista de Chimie. 2020; 71 (1):100-106.

Chicago/Turabian Style

Daniel Mitru; Gheorghe Nechifor; Stefania Gheorghe; Alina Roxana Banciu; Lucian Ionescu; Catalina Stoica; Daniela Liliana Ionica; Irina Eugenia Lucaciu. 2020. "Removal and Effects of Surfactants in Activated Sludge System." Revista de Chimie 71, no. 1: 100-106.

Journal article
Published: 07 February 2020 in Revista de Chimie
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The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

ACS Style

Salman H. Abbas; Younis Younis; Mohammed K. Hussain; Firas Hashim Kamar; Gheorghe Nechifor; Bianca Pasca. Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column. Revista de Chimie 2020, 71, 1 -12.

AMA Style

Salman H. Abbas, Younis Younis, Mohammed K. Hussain, Firas Hashim Kamar, Gheorghe Nechifor, Bianca Pasca. Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column. Revista de Chimie. 2020; 71 (1):1-12.

Chicago/Turabian Style

Salman H. Abbas; Younis Younis; Mohammed K. Hussain; Firas Hashim Kamar; Gheorghe Nechifor; Bianca Pasca. 2020. "Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column." Revista de Chimie 71, no. 1: 1-12.

Journal article
Published: 23 January 2020 in Journal of Clinical Medicine
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The present study aimed to assess the eighteen month follow-up patient-centered outcomes of a simple and predictable protocol for 3D-printed functional complete dentures manufactured using an improved poly(methyl methacrylate) (PMMA)–nanoTiO2. A detailed morphological and structural characterization of the PMMA–TiO2 nanocomposite, using SEM, EDX, XRD, and AFM, after 3D-printing procedure and post-wearing micro-CT, was also performed. Methods: A total of 35 fully edentulous patients were enrolled in this prospective study. A 0.4% TiO2-nanoparticle-reinforced PMMA composite with improved mechanical strength, morphologically and structurally characterized, was used according to an additive computer-aided design and computer-aided manufacturing (CAD/CAM) protocol for complete denture fabrication. The protocol proposed involved a three-step appointment process. Before denture insertion, 1 week, 12 month, and 18-month follow up patients were evaluated via the Visual Analogue Scale (VAS, 0–10) and Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT), with a higher score meaning poor quality of life. Results: A total of 45 complete denture sets were inserted. OHIP-EDENT scored significantly better after 18 months of denture wearing, 20.43 (±4.42) compared to 52.57 (±8.16) before treatment; mean VAS was improved for all parameters assessed. Conclusions: Within the limitations of this study, we can state that the proposed workflow with the improved material used is a viable treatment option for patients diagnosed with complete edentulism.

ACS Style

Corina Marilena Cristache; Eugenia Eftimie Totu; Gabriela Iorgulescu; Aida Pantazi; Dorel Dorobantu; Aurelia Cristina Nechifor; Ibrahim Isildak; Mihai Burlibasa; Gheorghe Nechifor; Marius Enachescu. Eighteen Months Follow-Up with Patient-Centered Outcomes Assessment of Complete Dentures Manufactured Using a Hybrid Nanocomposite and Additive CAD/CAM Protocol. Journal of Clinical Medicine 2020, 9, 324 .

AMA Style

Corina Marilena Cristache, Eugenia Eftimie Totu, Gabriela Iorgulescu, Aida Pantazi, Dorel Dorobantu, Aurelia Cristina Nechifor, Ibrahim Isildak, Mihai Burlibasa, Gheorghe Nechifor, Marius Enachescu. Eighteen Months Follow-Up with Patient-Centered Outcomes Assessment of Complete Dentures Manufactured Using a Hybrid Nanocomposite and Additive CAD/CAM Protocol. Journal of Clinical Medicine. 2020; 9 (2):324.

Chicago/Turabian Style

Corina Marilena Cristache; Eugenia Eftimie Totu; Gabriela Iorgulescu; Aida Pantazi; Dorel Dorobantu; Aurelia Cristina Nechifor; Ibrahim Isildak; Mihai Burlibasa; Gheorghe Nechifor; Marius Enachescu. 2020. "Eighteen Months Follow-Up with Patient-Centered Outcomes Assessment of Complete Dentures Manufactured Using a Hybrid Nanocomposite and Additive CAD/CAM Protocol." Journal of Clinical Medicine 9, no. 2: 324.

Journal article
Published: 10 January 2020 in Scientific Reports
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There is an increased interest in recycling valuable waste materials for usage in procedures with high added values. Silica microparticles are involved in the processes of catalysis, separation, immobilization of complexants, biologically active compounds, and different nanospecies, responding to restrictive requirements for selectivity of various chemical and biochemical processes. This paper presents the surface modification of accessible and dimensionally controlled recycled silica microfiber with titanium dioxide. Strong base species in organic solvents: methoxide, ethoxide, propoxide, and potassium butoxide in corresponding alcohol, activated the glass microfibres with 12–13 µm diameter. In the photo-oxidation process of a toxic micro-pollutant, cyclophosphamide, the new composite material successfully proved photocatalytic effectiveness. The present work fulfills simultaneously two specific objectives related to the efforts directed towards a sustainable environment and circular economy: recycling of optical glass microfibers resulted as waste from the industry, and their usage for the photo-oxidation of highly toxic emerging micro-pollutants.

ACS Style

Gheorghe Nechifor; Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Lucian - Alexandru Constantin; Alina Mirela Constantin; Mihaela Elena Cărăuşu; Ibrahim Isildak. Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants. Scientific Reports 2020, 10, 136 -16.

AMA Style

Gheorghe Nechifor, Eugenia Eftimie Totu, Aurelia Cristina Nechifor, Lucian - Alexandru Constantin, Alina Mirela Constantin, Mihaela Elena Cărăuşu, Ibrahim Isildak. Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants. Scientific Reports. 2020; 10 (1):136-16.

Chicago/Turabian Style

Gheorghe Nechifor; Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Lucian - Alexandru Constantin; Alina Mirela Constantin; Mihaela Elena Cărăuşu; Ibrahim Isildak. 2020. "Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants." Scientific Reports 10, no. 1: 136-16.

Journal article
Published: 25 December 2019 in Nanomaterials
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The paper deals with the preparation and characterisation of hydroalcoholic polyphenolic extract from Sambucus ebulus (SE) leaves that was further loaded into three-types of lipid vesicles: liposomes, transfersomes, and ethosomes, to improve its bioavailability and achieve an optimum pharmacological effect. For Sambucus ebulus L.-loaded lipid vesicles, the entrapment efficiency, particle size, polydispersity index and stability were determined. All prepared lipid vesicles showed a good entrapment efficiency, in the range of 75–85%, nanometric size, low polydispersity indexes, and good stability over three months at 4 °C. The in vitro polyphenols released from lipid vehicles demonstrated slower kinetics when compared to the free extract dissolution in phosphate buffer solution at pH 7.4. Either free SE extract or SE extract loaded into lipid vesicles demonstrated a cytoprotective effect, even at low concentration, 5 ug/mL, against hydrogen peroxide-induced toxicity on L-929 mouse fibroblasts’ cell lines. However, the cytoprotective effect depended on the time of the cells pre-treatment with SE extract before exposure to a hydrogen peroxide solution of 50 mM concentration, requiring at least 12 h of pre-treatment with polyphenols with radical scavenging capacity.

ACS Style

Ramona-Daniela Păvăloiu; Fawzia Sha’At; Corina Bubueanu; Mihaela Deaconu; Georgeta Neagu; Mousa Sha’At; Mihai Anastasescu; Mona Mihailescu; Cristian Matei; Gheorghe Nechifor; Daniela Berger; Fawzia Shaat. Polyphenolic Extract from Sambucus ebulus L. Leaves Free and Loaded into Lipid Vesicles. Nanomaterials 2019, 10, 56 .

AMA Style

Ramona-Daniela Păvăloiu, Fawzia Sha’At, Corina Bubueanu, Mihaela Deaconu, Georgeta Neagu, Mousa Sha’At, Mihai Anastasescu, Mona Mihailescu, Cristian Matei, Gheorghe Nechifor, Daniela Berger, Fawzia Shaat. Polyphenolic Extract from Sambucus ebulus L. Leaves Free and Loaded into Lipid Vesicles. Nanomaterials. 2019; 10 (1):56.

Chicago/Turabian Style

Ramona-Daniela Păvăloiu; Fawzia Sha’At; Corina Bubueanu; Mihaela Deaconu; Georgeta Neagu; Mousa Sha’At; Mihai Anastasescu; Mona Mihailescu; Cristian Matei; Gheorghe Nechifor; Daniela Berger; Fawzia Shaat. 2019. "Polyphenolic Extract from Sambucus ebulus L. Leaves Free and Loaded into Lipid Vesicles." Nanomaterials 10, no. 1: 56.

Journal article
Published: 15 October 2019 in Revista de Chimie
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Three composite membranes (M1-M3), with mesoporous silica (MCM-41 or HMS-C12/C16-type) embedded in polysulfone (Psf) were obtained by phase-inversion method and their performances were tested for use in ultrafiltration membrane processes. The structures of M (Psf 12%, reference membrane), M1 (Psf 12% + MCM-41), M2 (Psf 12% + HMS-C12), M3 (Psf 12% + HMS-C16) have been assessed by FTIR, TG-DSC and SEM-EDAX and the morphology and their hydrodynamic performances have been evaluated by contact angle measurements, dead-end and cross-flow filtration experiments.

ACS Style

Anca Razvan; Daniela F. Popa; Ovidiu Oprea; Eugeniu Vasile; Florina Dumitru; Gheorghe Nechifor. Ultrafiltration Mixed Matrix Membranes Based on Mesoporous Silica (MCM-41, HMS)Embedded in Polysulfone. Revista de Chimie 2019, 70, 3089 -3093.

AMA Style

Anca Razvan, Daniela F. Popa, Ovidiu Oprea, Eugeniu Vasile, Florina Dumitru, Gheorghe Nechifor. Ultrafiltration Mixed Matrix Membranes Based on Mesoporous Silica (MCM-41, HMS)Embedded in Polysulfone. Revista de Chimie. 2019; 70 (9):3089-3093.

Chicago/Turabian Style

Anca Razvan; Daniela F. Popa; Ovidiu Oprea; Eugeniu Vasile; Florina Dumitru; Gheorghe Nechifor. 2019. "Ultrafiltration Mixed Matrix Membranes Based on Mesoporous Silica (MCM-41, HMS)Embedded in Polysulfone." Revista de Chimie 70, no. 9: 3089-3093.

Journal article
Published: 15 August 2019 in Revista de Chimie
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The aim of this paper was the design and evaluation of delivery system for Armoracia rusticana leaves extract with the purpose to use such systems in food or cosmetic field. Liposomes loaded with Armoracia rusticana were prepared by film hydration method and presented good entrapment efficiency, nano-sizes ([150 nm), low polydispersity index and good stability over 90 days at 4oC. In vitro drug release study showed the ability of liposomes to provide slow release of extract with reduced burst effect compared to free extract. These promising results suggest that liposomes could be exploited as carriers for herbal ingredients.

ACS Style

Ramona-Daniela Pavaloiu; Fawzia Sha At; Corina Bubueanu; Cristina Hlevca; Gheorghe Nechifor. Design and Evaluation of a Delivery System Based on Liposomes for Armoracia rusticana Extract. Revista de Chimie 2019, 70, 2347 -2349.

AMA Style

Ramona-Daniela Pavaloiu, Fawzia Sha At, Corina Bubueanu, Cristina Hlevca, Gheorghe Nechifor. Design and Evaluation of a Delivery System Based on Liposomes for Armoracia rusticana Extract. Revista de Chimie. 2019; 70 (7):2347-2349.

Chicago/Turabian Style

Ramona-Daniela Pavaloiu; Fawzia Sha At; Corina Bubueanu; Cristina Hlevca; Gheorghe Nechifor. 2019. "Design and Evaluation of a Delivery System Based on Liposomes for Armoracia rusticana Extract." Revista de Chimie 70, no. 7: 2347-2349.

Journal article
Published: 08 July 2019 in Nanomaterials
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The polymer-inorganic nanoparticles composite membranes are the latest solutions for multiple physicochemical resistance and selectivity requirements of membrane processes. This paper presents the production of polysulfone-silica microfiber grafted with titanium dioxide nanoparticles (PSf-SiO2-TiO2) composite membranes. Silica microfiber of length 150–200 μm and diameter 12–15 μm were grafted with titanium dioxide nanoparticles, which aggregated as microspheres of 1–3 μm, applying the sol-gel method. The SiO2 microfibers grafted with nano-TiO2 were used to prepare 12% polysulfone-based nanocomposite membranes in N-methyl pyrrolidone through the inversion phase method by evaporation. The obtained nanocomposite membranes, PSf-SiO2-TiO2, have flux characteristics, retention, mechanical characteristics, and chemical oxidation resistance superior to both the polysulfone integral polymer membranes and the PSf-SiO2 composite membranes. The antimicrobial tests highlighted the inhibitory effect of the PSf-SiO2-TiO2 composite membranes on five Gram (-) microorganisms and did not allow the proliferation of Candida albicans strain, proving that they are suitable for usage in the oral environment. The designed membrane met the required characteristics for application as a functional barrier in guided bone regeneration.

ACS Style

Gheorghe Nechifor; Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Ibrahim Isildak; Ovidiu Oprea; Corina Marilena Cristache. Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2. Nanomaterials 2019, 9, 985 .

AMA Style

Gheorghe Nechifor, Eugenia Eftimie Totu, Aurelia Cristina Nechifor, Ibrahim Isildak, Ovidiu Oprea, Corina Marilena Cristache. Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2. Nanomaterials. 2019; 9 (7):985.

Chicago/Turabian Style

Gheorghe Nechifor; Eugenia Eftimie Totu; Aurelia Cristina Nechifor; Ibrahim Isildak; Ovidiu Oprea; Corina Marilena Cristache. 2019. "Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2." Nanomaterials 9, no. 7: 985.