Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to c... more Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to cellular damage and tissue injury. Natural antioxidants compounds found in agro-industrial by-products have proven their effectiveness in treatment of intestinal inflammation and oxidative stress, exhibiting many favourable effects. The aim of this study was to evaluate the capacity of a grape seed meal byproduct (GSM) to counteract the effects induced by E. coli lipopolysaccharide (LPS, 5μg/ml) in vitro on IPEC-1 cells and by dextran sulphate sodium (DSS, 1g/b.w./day) in vivo on piglets after weaning. Reactive oxygen species (ROS), pro-oxidant markers (malondialdehyde MDA, thiobarbituric acid reactive substances TBARS, protein carbonyl, DNA oxidative damage) antioxidant enzymes (catalase -CAT, superoxide dismutase -SOD, glutathione peroxidase -GPx, endothelial and inducible nitric oxide synthases -eNOS and iNOS) and several important components of Keap1/Nrf2 signalling pathway were analy...
The presence of nitrite and nitrate in milk and dairy products may cause serious health problem f... more The presence of nitrite and nitrate in milk and dairy products may cause serious health problem for consumers. Thus, a simple and accurate ion-pair reversed-phase high performance liquid chromatographic (IP-RP-HPLC) method has been developed and validated for determination of nitrite and nitrate in some dairy drinks based on Zonar Milk Serum. The separation was achieved on a Synergy Hydro-RP polar endcapped C18, 80Å, 4m (250 4.6 mm) column using isocratic elution with 0.01M n-octylamine and methanol, 90:10 (v/v) at pH=7; with flow rate of 1 mL•min-1 and detection at 214 nm and 25°C. A linear response (R 2 ≥ 0.9994) was observed in the range between 3.125 and 75 µg mL-1 for the nitrite and nitrate standard solutions. The limits of detection (LOD) and quantification (LOQ) were found as 0.25 µg mL-1 and 0.8 µg mL-1 for nitrite and 0.4 µg mL-1 and 1.2 µg mL-1 for nitrate, respectively. The method was validated according to ICH guidelines with respect to selectivity, linearity, detection and quantitation limits, accuracy, precision. The good analytical performance verified for this method indicates that it is suitable the monitoring of nitrite and nitrate in dairy drinks based on Zonar Milk Serum.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in... more In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in cow milk by solid phase extraction (SPE) and high performance liquid chromatography-diode array detection (HPLC-DAD) method was perform. Five different SPE cartridges were tested in order to evaluate the isolation of purine derivatives (PD) from cow milk. Chromatography was carried out on ODS-2 Hypersil column and 0.05 M (NH4)2HPO4 buffer solution (pH = 7.76) as mobile phase. The HPLC-DAD validated method showed a linearity with regression coefficients higher than 0.999 and the limits of detection and quantification with values in the range 0.09–0.74 µg mL–1 and 0.27–2.24 µg mL–1, respectively. The method showed good precision with a relative standard deviation (RSD) below 4.48%, while the accuracy ranged from 95.34 to 104.47% for all analytes. The best recovery degree of PD by SPE were obtained on Strata SCX cartridge for xanthine (87.79%) and hypoxanthine (89.02%); on Strata NH2 for a...
Antibiotics are natural or semi-synthetic compounds used for many decades in human, veterinary an... more Antibiotics are natural or semi-synthetic compounds used for many decades in human, veterinary and plant medicine to prevent and/or to treat bacterial infections and also to promote productivity in animal farming. Traces of antibiotics are found in waste, surface and ground waters, the main source of water pollution being considered waste waters from the industrial production, hospitals, livestock farms, households and incompletely metabolized drugs. The uncontrolled input of antibiotics in surface waters can lead to some unexpected health effects and to an increased resistance to these drugs. The aim of this work consists in the monitoring of six antibiotics (Ampicillin, Amoxicillin, Penicillin G, Ceftazidime, Tetracycline and Doxycycline) in river waters and sediment samples from the Romanian Tisza River Watershed. Solid-phase extraction (SPE) on Oasis HLB Waters cartridges was used for the isolation of antibiotics from water matrices and ultrasound-assisted extraction (USAE) followed by SPE for the sediment samples. Then, the antibiotics were analysed by high-performance liquid chromatography coupled with diode array detector or mass spectrometer (HPLC-DAD/MS). The developed SPE/USAE-HPLC-DAD/MS procedures were applied to monitor these antibiotics in river waters during thirteen months and to analyse them in some sediment samples. The obtained results showed the presence of Tetracycline, Doxycycline and Ceftazidime in the investigated samples.
Polymers represent a novel alternative in bone regeneration. Polydioxanone combined with Pluronic... more Polymers represent a novel alternative in bone regeneration. Polydioxanone combined with Pluronic was used as a carrier for Oxytocin in form of an interfacial deposition obtained scaffold. The low rate of resorption of the scaffold follow the bone regeneration sequence assuring a constant and continuous release of Oxytocin. The Oxytocin release was monitored by RP-HPLC method. The separation was performed on a Phenomenex Luna 5μm C18 100A, 250x4.6mm, using isocratic elution with acetonitrile: phosphate buffer pH 7 (30:70 v/v) mobile phase. Flow rate 1 ml / min, column temperature 30°C, DAD, λ= 220nm. The surface morphology of polydioxanone pluronic 127 Oxytocin impregnated mesh was characterized by SEM. The preliminary results show that the Polydioxanone combined with Pluronic is a promising polymer for bone regeneration engineering.
Pharmaceuticals are compounds intensively used to treat human and animal diseases that end into t... more Pharmaceuticals are compounds intensively used to treat human and animal diseases that end into the surface waters coming from the industrial production, hospitals or households. Because of their toxicity and relative persistence in the water bodies, pharmaceuticals are considered as main micropollutants thereof. Some unexpected health effects have been observed during the last time that are explained by an increased resistance of human and animal bodies to pharmaceuticals caused by their uncontrolled input in surface waters. As a result, the European Union started to pay a special attention to this subject, the European Parliament amending the Water Framework Directive (2000/60/EC) being preoccupied to introduce some emerging pollutants, namely diclofenac (anti-inflammatory) and 17beta-estradiol (hormone), in the list of priority substances and to establish their maximum allowable concentration in surface waters. In this work, the authors present the profile of some pharmaceuticals...
The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone... more The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP...
The purpose of this study was to investigate the potential of a byproduct mixture derived from gr... more The purpose of this study was to investigate the potential of a byproduct mixture derived from grapeseed and sea buckthorn oil industry to mitigate the harmful damage produced by ochratoxin A and aflatoxin B1 at hepatic and renal level in piglets after weaning. Forty cross-bred TOPIGS-40 hybrid piglets after weaning were assigned to three experimental groups (E1, E2, E3) and one control group (C), and fed with experimental diets for 30 days. The basal diet was served as a control and contained normal compound feed for starter piglets without mycotoxins. The experimental groups were fed as follows: E1—basal diet plus a mixture (1:1) of two byproducts (grapeseed and sea buckthorn meal); E2—the basal diet experimentally contaminated with mycotoxins (479 ppb OTA and 62ppb AFB1); and E3—basal diet containing 5% of the mixture (1:1) of grapeseed and sea buckthorn meal and contaminated with the mix of OTA and AFB1. After 4 weeks, the animals were slaughtered, and tissue samples were taken ...
The compound [2,6-(Me2NCH2)2C6H3]Hg(OAc) (1) was prepared by direct mercuration of 1,3-(Me2NCH2)2... more The compound [2,6-(Me2NCH2)2C6H3]Hg(OAc) (1) was prepared by direct mercuration of 1,3-(Me2NCH2)2C6H4 with Hg(OAc)2. Treatment of 1 with excess of LiCl resulted in isolation of the chloride [2,6-(Me2NCH2)2C6H3]HgCl (2) in a good yield. The IR spectroscopy confirms the presence of the acetate group in 1. Both compounds 1 and 2 were characterized by solution multinuclear (1H, 13C and 199Hg) NMR spectroscopy and mass spectrometry. Their crystal and molecular structures were established by single-crystal X-ray diffraction. Different intermolecular interactions, i.e. Hg···Hg, O···Hg and C‒H···π (Arcentroid), were found for both compounds in solid state resulting in dimer or chain polymer associations.
Hypercoordinated triaryltelluronium compounds of type [{2-(Me2NCH2)C6H4}3Te]+L [L = (SPMe2)2N (... more Hypercoordinated triaryltelluronium compounds of type [{2-(Me2NCH2)C6H4}3Te]+L [L = (SPMe2)2N (1), (OPPh2)2N (2), (SPPh2)2N (3), (SPPh2){OP(OEt)2}N (4), (SPPh2)(O2SMe)N (5) and {SP(OEt)2}(O2SC6H4Cl-4)N (6)] were prepared by salt metathesis reactions between [{2-(Me2NCH2)C6H4}3Te]Cl•H2O and the potassium salts of the corresponding organophosphorus ligands in a 1:1 molar ratio. Multinuclear NMR spectroscopy, mass spectrometry, molar conductivity and IR spectroscopy were used to characterize the new complexes. The 1H NMR spectra suggest for all compounds the intramolecular coordination of the nitrogen atoms from the pendant arms to tellurium in solution. For compound 3 single-crystal X-ray diffraction studies revealed strong N→Te intramolecular interactions in solid state, which result in hypercoordinated triaryltelluronium(IV) cations (14‒Te‒6 species) with a distorted octahedral coordination geometry around tellurium. Weak S⋅⋅⋅H interactions between anions and cations resulted in a...
The aim of this study was characterization of some dairy drinks based on Milk Serum regarding maj... more The aim of this study was characterization of some dairy drinks based on Milk Serum regarding major whey proteins (WP) and free amino acids (FAAs) using reversed phase high performance liquid chromatographic (RP-HPLC) methods. The studied WP, -lactalbumin (-La), bovine serum albumin (BSA), -lactoglobulin A (-Lg A) and -lactoglobulin B (-Lg B) were separated on Aeris XB-C18 column at 214 nm detection. The RP-HPLC method was validated by selectivity, linearity (R2 ≥0.99), sensitivity (LOQ, 1.35–10.08 µg mL−1), accuracy (recovery 96.79-103.07%) and precision (% RSD ≤ 4.13%). The total studied WP in studied dairy drinks varied between 1.42 and 3.047 g·L-1. The chromatographic profile of FAAs (aspartic acid, glutamic acid, serine, histidine, arginine, glycine, threonine, alanine, tyrosine, cysteine, tryptophan, methionine, valine, phenylalanine, isoleucine, leucine and lysine) was determined in lyophilized concentrate of Milk Serum by RP-HPLC using pre-column derivatization reaction with...
The novelty of this study consists in the formulation and characterization of three experimental ... more The novelty of this study consists in the formulation and characterization of three experimental dental composites (PM, P14M, P2S) for cervical dental lesion restoration compared to the commercial composites Enamel plus HRi® - En (Micerium S.p.A, Avengo, Ge, Italy), G-ænial Anterior® - Ge, (GC Europe N.V., Leuven, Belgium), Charisma® - Ch (Heraeus Kulzer, Berkshire, UK). The physio-chemical properties were studied, like the degree of conversion and the residual monomers in cured samples using FTIR-ATR (attenuated total reflectance) and HPLC-UV (ultraviolet detection), as well as the evaluation of the mechanical properties of the materials. The null hypothesis was that there would be no differences between experimental and commercial resin composites regarding the evaluated parameters. Statistical analysis revealed that water and saliva storage induced significant modifications of all mechanical parameters after three months for all tested materials, except for a few comparisons for ...
JPC - Journal of Planar Chromatography - Modern TLC, 2018
Thin-layer chromatography (TLC) is a frequently used technique for the separation of polar and no... more Thin-layer chromatography (TLC) is a frequently used technique for the separation of polar and non-polar compounds, with a rich literature in this field. The aim of this paper is to show the TLC adsorbent quality of the Nevşehir volcanic tuff from Turkey that is compared with the Mirșid volcanic tuff from Romania. Our experimental investigations have shown that it is possible to achieve TLC plates coated with Nevşehir volcanic tuff, in natural occurrence, excepting grinding and sieving processes, which can be used for the separation of polar compounds, such as amino acids or food dyes. In the present article, modern techniques for characterizing the volcanic tuff powders, namely, X-ray diffraction, inductively coupled plasma-optical emission spectrometry, scanning electron microscopy, specific surface area and porosity measurements, and infrared spectroscopy, were used in addition to the chromatographic testing. TLC plates coated with Nevşehir tuff were prepared and tested at the separation of some amino acids, obtaining good results. Also, the impregnation of Nevşehir tuff with NaOH and NaCl, respectively, allowed the separation of some hydrophilic dyes. The obtained results have contributed to understand the chromatographic properties of the Nevşehir volcanic tuff. The TLC capability of the Nevşehir tuff can enlarge the pallete of inexpensive adsorbents with possible applications in the field of layer chromatographic separations.
Dental light-curing giomers were developed to combine the favourable properties of diacrylic resi... more Dental light-curing giomers were developed to combine the favourable properties of diacrylic resin composites (DRCs) and glass-ionomer cements (GICs) in a single material and to eliminate their inherent drawbacks. Giomers are characterized by their aesthetic appearance, high mechanical properties, adhesion to dental tissues as well as fluoride release and recharge abilities. The qualities of the giomers are greatly influenced by the level of conversion of the component resins. Infrared spectroscopy is one of the most largely used techniques for the determination of the degree of conversion in resin-based dental materials. However different results were obtained due to the performances of the used methods. The present work presents the determination of conversion degree in a series of dental copolymers and their corresponding giomers using transmission Fourier transform infrared spectroscopy (FTIR) and an attenuated total reflection technique (ATR) technique, respectively, the main aim being the study of the influence of the materials composition and of the light curing modes upon the achieved conversion in the cured giomers. Beautifil II commercial giomer was used as a control. A halogen lamp and a diode-blue LED lamp were used for the curing of the materials. The results showed that the composition of the resins greatly influenced the conversion. The highest conversions (up to 79%) were obtained in the case of the experimental giomers which contained the experimental Bis-GMA urethane analogue, followed by the Beautifil II giomer (61%) and experimental giomers based on commercial Bis-GMA (up to 50%), respectively. The resins light-cured by using the diode-blue LED lamp presented slightly higher conversions than the resins cured by halogen lamp. The study demonstrates the possibility to evaluate easily and reproducibly the conversion in light-curing composite materials with complex chemical composition and structure, particularly in the case of giomers by using the ATR technique.
JPC - Journal of Planar Chromatography - Modern TLC, 2016
In our previous papers, we defined layer (planar) dielectrochromatography and we presented its fu... more In our previous papers, we defined layer (planar) dielectrochromatography and we presented its fundamentals (theoretical aspects) such as the displacement of dielectric liquids under nonuniform external alternating electric fields (dielectroosmotic flow [DEOF] effect), the displacement of solute particles or polarized granules (dielectrophoresis [DEP] effect) in electric fields generated by armatures, the theoretical evaluation of the electric intensity generated in the stratified dielectrics, etc. Ready-to-use plates of alumina, silica gel, and cellulose were used for experiments. The obtained results have encouraged us to create our own TLC plates based on alumina enriched with compounds of high dielectric constants like barium sulfate, barium titanate, and titanium dioxide. In this paper, we present the preparation of seven plates containing increasing amounts (1, 2, 3, 4, 6, 8, 10) g of barium titanate in 35 g alumina, the methodology used in their characterization, as well as the obtained results and the perspectives of using this ingredient.
Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to c... more Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to cellular damage and tissue injury. Natural antioxidants compounds found in agro-industrial by-products have proven their effectiveness in treatment of intestinal inflammation and oxidative stress, exhibiting many favourable effects. The aim of this study was to evaluate the capacity of a grape seed meal byproduct (GSM) to counteract the effects induced by E. coli lipopolysaccharide (LPS, 5μg/ml) in vitro on IPEC-1 cells and by dextran sulphate sodium (DSS, 1g/b.w./day) in vivo on piglets after weaning. Reactive oxygen species (ROS), pro-oxidant markers (malondialdehyde MDA, thiobarbituric acid reactive substances TBARS, protein carbonyl, DNA oxidative damage) antioxidant enzymes (catalase -CAT, superoxide dismutase -SOD, glutathione peroxidase -GPx, endothelial and inducible nitric oxide synthases -eNOS and iNOS) and several important components of Keap1/Nrf2 signalling pathway were analy...
The presence of nitrite and nitrate in milk and dairy products may cause serious health problem f... more The presence of nitrite and nitrate in milk and dairy products may cause serious health problem for consumers. Thus, a simple and accurate ion-pair reversed-phase high performance liquid chromatographic (IP-RP-HPLC) method has been developed and validated for determination of nitrite and nitrate in some dairy drinks based on Zonar Milk Serum. The separation was achieved on a Synergy Hydro-RP polar endcapped C18, 80Å, 4m (250 4.6 mm) column using isocratic elution with 0.01M n-octylamine and methanol, 90:10 (v/v) at pH=7; with flow rate of 1 mL•min-1 and detection at 214 nm and 25°C. A linear response (R 2 ≥ 0.9994) was observed in the range between 3.125 and 75 µg mL-1 for the nitrite and nitrate standard solutions. The limits of detection (LOD) and quantification (LOQ) were found as 0.25 µg mL-1 and 0.8 µg mL-1 for nitrite and 0.4 µg mL-1 and 1.2 µg mL-1 for nitrate, respectively. The method was validated according to ICH guidelines with respect to selectivity, linearity, detection and quantitation limits, accuracy, precision. The good analytical performance verified for this method indicates that it is suitable the monitoring of nitrite and nitrate in dairy drinks based on Zonar Milk Serum.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in... more In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in cow milk by solid phase extraction (SPE) and high performance liquid chromatography-diode array detection (HPLC-DAD) method was perform. Five different SPE cartridges were tested in order to evaluate the isolation of purine derivatives (PD) from cow milk. Chromatography was carried out on ODS-2 Hypersil column and 0.05 M (NH4)2HPO4 buffer solution (pH = 7.76) as mobile phase. The HPLC-DAD validated method showed a linearity with regression coefficients higher than 0.999 and the limits of detection and quantification with values in the range 0.09–0.74 µg mL–1 and 0.27–2.24 µg mL–1, respectively. The method showed good precision with a relative standard deviation (RSD) below 4.48%, while the accuracy ranged from 95.34 to 104.47% for all analytes. The best recovery degree of PD by SPE were obtained on Strata SCX cartridge for xanthine (87.79%) and hypoxanthine (89.02%); on Strata NH2 for a...
Antibiotics are natural or semi-synthetic compounds used for many decades in human, veterinary an... more Antibiotics are natural or semi-synthetic compounds used for many decades in human, veterinary and plant medicine to prevent and/or to treat bacterial infections and also to promote productivity in animal farming. Traces of antibiotics are found in waste, surface and ground waters, the main source of water pollution being considered waste waters from the industrial production, hospitals, livestock farms, households and incompletely metabolized drugs. The uncontrolled input of antibiotics in surface waters can lead to some unexpected health effects and to an increased resistance to these drugs. The aim of this work consists in the monitoring of six antibiotics (Ampicillin, Amoxicillin, Penicillin G, Ceftazidime, Tetracycline and Doxycycline) in river waters and sediment samples from the Romanian Tisza River Watershed. Solid-phase extraction (SPE) on Oasis HLB Waters cartridges was used for the isolation of antibiotics from water matrices and ultrasound-assisted extraction (USAE) followed by SPE for the sediment samples. Then, the antibiotics were analysed by high-performance liquid chromatography coupled with diode array detector or mass spectrometer (HPLC-DAD/MS). The developed SPE/USAE-HPLC-DAD/MS procedures were applied to monitor these antibiotics in river waters during thirteen months and to analyse them in some sediment samples. The obtained results showed the presence of Tetracycline, Doxycycline and Ceftazidime in the investigated samples.
Polymers represent a novel alternative in bone regeneration. Polydioxanone combined with Pluronic... more Polymers represent a novel alternative in bone regeneration. Polydioxanone combined with Pluronic was used as a carrier for Oxytocin in form of an interfacial deposition obtained scaffold. The low rate of resorption of the scaffold follow the bone regeneration sequence assuring a constant and continuous release of Oxytocin. The Oxytocin release was monitored by RP-HPLC method. The separation was performed on a Phenomenex Luna 5μm C18 100A, 250x4.6mm, using isocratic elution with acetonitrile: phosphate buffer pH 7 (30:70 v/v) mobile phase. Flow rate 1 ml / min, column temperature 30°C, DAD, λ= 220nm. The surface morphology of polydioxanone pluronic 127 Oxytocin impregnated mesh was characterized by SEM. The preliminary results show that the Polydioxanone combined with Pluronic is a promising polymer for bone regeneration engineering.
Pharmaceuticals are compounds intensively used to treat human and animal diseases that end into t... more Pharmaceuticals are compounds intensively used to treat human and animal diseases that end into the surface waters coming from the industrial production, hospitals or households. Because of their toxicity and relative persistence in the water bodies, pharmaceuticals are considered as main micropollutants thereof. Some unexpected health effects have been observed during the last time that are explained by an increased resistance of human and animal bodies to pharmaceuticals caused by their uncontrolled input in surface waters. As a result, the European Union started to pay a special attention to this subject, the European Parliament amending the Water Framework Directive (2000/60/EC) being preoccupied to introduce some emerging pollutants, namely diclofenac (anti-inflammatory) and 17beta-estradiol (hormone), in the list of priority substances and to establish their maximum allowable concentration in surface waters. In this work, the authors present the profile of some pharmaceuticals...
The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone... more The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP...
The purpose of this study was to investigate the potential of a byproduct mixture derived from gr... more The purpose of this study was to investigate the potential of a byproduct mixture derived from grapeseed and sea buckthorn oil industry to mitigate the harmful damage produced by ochratoxin A and aflatoxin B1 at hepatic and renal level in piglets after weaning. Forty cross-bred TOPIGS-40 hybrid piglets after weaning were assigned to three experimental groups (E1, E2, E3) and one control group (C), and fed with experimental diets for 30 days. The basal diet was served as a control and contained normal compound feed for starter piglets without mycotoxins. The experimental groups were fed as follows: E1—basal diet plus a mixture (1:1) of two byproducts (grapeseed and sea buckthorn meal); E2—the basal diet experimentally contaminated with mycotoxins (479 ppb OTA and 62ppb AFB1); and E3—basal diet containing 5% of the mixture (1:1) of grapeseed and sea buckthorn meal and contaminated with the mix of OTA and AFB1. After 4 weeks, the animals were slaughtered, and tissue samples were taken ...
The compound [2,6-(Me2NCH2)2C6H3]Hg(OAc) (1) was prepared by direct mercuration of 1,3-(Me2NCH2)2... more The compound [2,6-(Me2NCH2)2C6H3]Hg(OAc) (1) was prepared by direct mercuration of 1,3-(Me2NCH2)2C6H4 with Hg(OAc)2. Treatment of 1 with excess of LiCl resulted in isolation of the chloride [2,6-(Me2NCH2)2C6H3]HgCl (2) in a good yield. The IR spectroscopy confirms the presence of the acetate group in 1. Both compounds 1 and 2 were characterized by solution multinuclear (1H, 13C and 199Hg) NMR spectroscopy and mass spectrometry. Their crystal and molecular structures were established by single-crystal X-ray diffraction. Different intermolecular interactions, i.e. Hg···Hg, O···Hg and C‒H···π (Arcentroid), were found for both compounds in solid state resulting in dimer or chain polymer associations.
Hypercoordinated triaryltelluronium compounds of type [{2-(Me2NCH2)C6H4}3Te]+L [L = (SPMe2)2N (... more Hypercoordinated triaryltelluronium compounds of type [{2-(Me2NCH2)C6H4}3Te]+L [L = (SPMe2)2N (1), (OPPh2)2N (2), (SPPh2)2N (3), (SPPh2){OP(OEt)2}N (4), (SPPh2)(O2SMe)N (5) and {SP(OEt)2}(O2SC6H4Cl-4)N (6)] were prepared by salt metathesis reactions between [{2-(Me2NCH2)C6H4}3Te]Cl•H2O and the potassium salts of the corresponding organophosphorus ligands in a 1:1 molar ratio. Multinuclear NMR spectroscopy, mass spectrometry, molar conductivity and IR spectroscopy were used to characterize the new complexes. The 1H NMR spectra suggest for all compounds the intramolecular coordination of the nitrogen atoms from the pendant arms to tellurium in solution. For compound 3 single-crystal X-ray diffraction studies revealed strong N→Te intramolecular interactions in solid state, which result in hypercoordinated triaryltelluronium(IV) cations (14‒Te‒6 species) with a distorted octahedral coordination geometry around tellurium. Weak S⋅⋅⋅H interactions between anions and cations resulted in a...
The aim of this study was characterization of some dairy drinks based on Milk Serum regarding maj... more The aim of this study was characterization of some dairy drinks based on Milk Serum regarding major whey proteins (WP) and free amino acids (FAAs) using reversed phase high performance liquid chromatographic (RP-HPLC) methods. The studied WP, -lactalbumin (-La), bovine serum albumin (BSA), -lactoglobulin A (-Lg A) and -lactoglobulin B (-Lg B) were separated on Aeris XB-C18 column at 214 nm detection. The RP-HPLC method was validated by selectivity, linearity (R2 ≥0.99), sensitivity (LOQ, 1.35–10.08 µg mL−1), accuracy (recovery 96.79-103.07%) and precision (% RSD ≤ 4.13%). The total studied WP in studied dairy drinks varied between 1.42 and 3.047 g·L-1. The chromatographic profile of FAAs (aspartic acid, glutamic acid, serine, histidine, arginine, glycine, threonine, alanine, tyrosine, cysteine, tryptophan, methionine, valine, phenylalanine, isoleucine, leucine and lysine) was determined in lyophilized concentrate of Milk Serum by RP-HPLC using pre-column derivatization reaction with...
The novelty of this study consists in the formulation and characterization of three experimental ... more The novelty of this study consists in the formulation and characterization of three experimental dental composites (PM, P14M, P2S) for cervical dental lesion restoration compared to the commercial composites Enamel plus HRi® - En (Micerium S.p.A, Avengo, Ge, Italy), G-ænial Anterior® - Ge, (GC Europe N.V., Leuven, Belgium), Charisma® - Ch (Heraeus Kulzer, Berkshire, UK). The physio-chemical properties were studied, like the degree of conversion and the residual monomers in cured samples using FTIR-ATR (attenuated total reflectance) and HPLC-UV (ultraviolet detection), as well as the evaluation of the mechanical properties of the materials. The null hypothesis was that there would be no differences between experimental and commercial resin composites regarding the evaluated parameters. Statistical analysis revealed that water and saliva storage induced significant modifications of all mechanical parameters after three months for all tested materials, except for a few comparisons for ...
JPC - Journal of Planar Chromatography - Modern TLC, 2018
Thin-layer chromatography (TLC) is a frequently used technique for the separation of polar and no... more Thin-layer chromatography (TLC) is a frequently used technique for the separation of polar and non-polar compounds, with a rich literature in this field. The aim of this paper is to show the TLC adsorbent quality of the Nevşehir volcanic tuff from Turkey that is compared with the Mirșid volcanic tuff from Romania. Our experimental investigations have shown that it is possible to achieve TLC plates coated with Nevşehir volcanic tuff, in natural occurrence, excepting grinding and sieving processes, which can be used for the separation of polar compounds, such as amino acids or food dyes. In the present article, modern techniques for characterizing the volcanic tuff powders, namely, X-ray diffraction, inductively coupled plasma-optical emission spectrometry, scanning electron microscopy, specific surface area and porosity measurements, and infrared spectroscopy, were used in addition to the chromatographic testing. TLC plates coated with Nevşehir tuff were prepared and tested at the separation of some amino acids, obtaining good results. Also, the impregnation of Nevşehir tuff with NaOH and NaCl, respectively, allowed the separation of some hydrophilic dyes. The obtained results have contributed to understand the chromatographic properties of the Nevşehir volcanic tuff. The TLC capability of the Nevşehir tuff can enlarge the pallete of inexpensive adsorbents with possible applications in the field of layer chromatographic separations.
Dental light-curing giomers were developed to combine the favourable properties of diacrylic resi... more Dental light-curing giomers were developed to combine the favourable properties of diacrylic resin composites (DRCs) and glass-ionomer cements (GICs) in a single material and to eliminate their inherent drawbacks. Giomers are characterized by their aesthetic appearance, high mechanical properties, adhesion to dental tissues as well as fluoride release and recharge abilities. The qualities of the giomers are greatly influenced by the level of conversion of the component resins. Infrared spectroscopy is one of the most largely used techniques for the determination of the degree of conversion in resin-based dental materials. However different results were obtained due to the performances of the used methods. The present work presents the determination of conversion degree in a series of dental copolymers and their corresponding giomers using transmission Fourier transform infrared spectroscopy (FTIR) and an attenuated total reflection technique (ATR) technique, respectively, the main aim being the study of the influence of the materials composition and of the light curing modes upon the achieved conversion in the cured giomers. Beautifil II commercial giomer was used as a control. A halogen lamp and a diode-blue LED lamp were used for the curing of the materials. The results showed that the composition of the resins greatly influenced the conversion. The highest conversions (up to 79%) were obtained in the case of the experimental giomers which contained the experimental Bis-GMA urethane analogue, followed by the Beautifil II giomer (61%) and experimental giomers based on commercial Bis-GMA (up to 50%), respectively. The resins light-cured by using the diode-blue LED lamp presented slightly higher conversions than the resins cured by halogen lamp. The study demonstrates the possibility to evaluate easily and reproducibly the conversion in light-curing composite materials with complex chemical composition and structure, particularly in the case of giomers by using the ATR technique.
JPC - Journal of Planar Chromatography - Modern TLC, 2016
In our previous papers, we defined layer (planar) dielectrochromatography and we presented its fu... more In our previous papers, we defined layer (planar) dielectrochromatography and we presented its fundamentals (theoretical aspects) such as the displacement of dielectric liquids under nonuniform external alternating electric fields (dielectroosmotic flow [DEOF] effect), the displacement of solute particles or polarized granules (dielectrophoresis [DEP] effect) in electric fields generated by armatures, the theoretical evaluation of the electric intensity generated in the stratified dielectrics, etc. Ready-to-use plates of alumina, silica gel, and cellulose were used for experiments. The obtained results have encouraged us to create our own TLC plates based on alumina enriched with compounds of high dielectric constants like barium sulfate, barium titanate, and titanium dioxide. In this paper, we present the preparation of seven plates containing increasing amounts (1, 2, 3, 4, 6, 8, 10) g of barium titanate in 35 g alumina, the methodology used in their characterization, as well as the obtained results and the perspectives of using this ingredient.
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Papers by mihaela vlassa