Behaviour of 316L Stainless Steel in Simulated Physiological Fluids AURORA ANCA POINESCU 1 , RODICA-MARIANA ION 1,2 , IONICA IONITA

In contact with biological systems all metals corrode and metal ions freed acts as haptens, forming complexes with native proteins that activate the immune system Experimental part Materials and methods Materials In this respect on this study were made a series of investigations to determine the content of Fe, Cu, Ni and Cr which can migrate from 316L stainless steel (powder and plate), under controlled conditions in the artificial plasma or serum. These investigations were conducted using energy dispersive X-ray fluorescence (EDXRF) spectroscopy and flame atomic absorption spectrometry/ electrothermal atomic absorption spectrometry. The biomaterials used on this study were: -316L stainless steel plate; -316L stainless steel powder; The surgical austenitic grade of stainless steel, such as 316L has the composition: 16-18% Cr; 10-15% Ni; Mo 2-3%; Mn 2%; P 0.04%; 0.035% C; Si 0.03%, S 0.03%; Fe the remaining up to 100%. The determination of Fe, Ni, Cr and Mn from physiological saline (0.9% NaCl) and artificial plasma Methodology The qualitative analysis is very sensitive and it works for both liquid and solid to ppm for all elements from B to Al. The solid samples intended quantitative analysis are in the form of powder and plate with thickness greater than 2 mm and less than 3 cm discs. The liquid samples were analyzed in special tanks made of plastic, covered with a plastic foil (Mylar) to remove the effects of the vacuum. The analysis of the liquid witness samples (saline, 0.9 % NaCl and artificial plasma) and monitored on a sample period were conducted by energy dispersive X-ray fluorescence spectroscopy using Elvax spectrometer. Spectra were processed using software Elvax. From the qualitative point of view, this method provides information on the initial elemental composition of materials composites, as well as of simulated samples of simulated body fluid (SBF) with biocomposites materials studied. The artificial plasma was prepared according to the literature Four samples were prepared by introducing the solid weighed samples in sterile vial of 100 mL by polyethylene terephthalate; 2 samples solids was treated with 50 mL of commercial normal saline and 2 solid sample with 50 m

Correlation between Enzymatic and Non-Enzymatic Antioxidants in Several Edible Mushrooms Species

Characterization of several wild growing and cultivated mushrooms from geographical area of Dambovita County, Romania, in terms of enzymatic and non-enzymatic antioxidants, through a chemometrics approach, was the aim of this study. Related to the authors’ previous studies, the novelty of this paper consists in deepening research toward the complete characterization of the regional mushroom species through emphasizing their potential as food resources. In the context in which species showed their content in biological active compounds, future practical applications in the area of functional food will be developed by integrating the data concerning their lack of the toxicity and nutritional value too. Lack of data focused on the characterization of mushroom species investigated in the paper supports the significance of this research. The statistical analysis of data highlights the relationship between compounds showing antioxidant activity of autochthonous mushrooms (both cap and stipe)

Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery

Currently, approximately 70% of paintings in museum collections are affected by the presence of metallic soaps, evidenced by spherical globules visible on the surface of the paintings. They are responsible for altering the paintings’ surface through processes such as exfoliation and cracking, or even in the form of surface “skins” that appear in the pictorial layers. The objective of this study is the investigation of the icon paintings from Saint Mary Monastery, Techirghiol, Romania, which underwent some restoration procedures. This study is so important/significant, due to the presence of efflorescence that is correlated with the conversion of some fatty acids, as palmitic acid, stearic acid and azelaic acid, in the so-called metallic soaps through the reaction of the metals contained in the pigments from the painting layer and the binder. The investigated paintings are strongly affected by zinc carboxylate aggregation, and for this, the sample was embedded in polyester resin and the obtained cross-section, after polishing, was investigated by microscopic techniques (optical microscopy (OM), stereomicroscopy, and scanning electron microscopy with electronic dispersion spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and gas-chromatography with mass spectrometry (GC-MS) in good agreement with data from the literature. The potential result of this study is the identification and quantification of the metallic soap generated as a white deposit (probably salts, a kind of white efflorescence), from the binding medium of the metal carboxylate ionomer, by the crystallization of saturated fatty acids, through polymerization in oil. Six pigments (calcite, lithopone, carbon black, red ochre, vermilion, and ultramarine), present in the sublayers of the samples were identified

Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery

Currently, approximately 70% of paintings in museum collections are affected by the presence of metallic soaps, evidenced by spherical globules visible on the surface of the paintings. They are responsible for altering the paintings’ surface through processes such as exfoliation and cracking, or even in the form of surface “skins” that appear in the pictorial layers. The objective of this study is the investigation of the icon paintings from Saint Mary Monastery, Techirghiol, Romania, which underwent some restoration procedures. This study is so important/significant, due to the presence of efflorescence that is correlated with the conversion of some fatty acids, as palmitic acid, stearic acid and azelaic acid, in the so-called metallic soaps through the reaction of the metals contained in the pigments from the painting layer and the binder. The investigated paintings are strongly affected by zinc carboxylate aggregation, and for this, the sample was embedded in polyester resin and the obtained cross-section, after polishing, was investigated by microscopic techniques (optical microscopy (OM), stereomicroscopy, and scanning electron microscopy with electronic dispersion spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and gas-chromatography with mass spectrometry (GC-MS) in good agreement with data from the literature. The potential result of this study is the identification and quantification of the metallic soap generated as a white deposit (probably salts, a kind of white efflorescence), from the binding medium of the metal carboxylate ionomer, by the crystallization of saturated fatty acids, through polymerization in oil. Six pigments (calcite, lithopone, carbon black, red ochre, vermilion, and ultramarine), present in the sublayers of the samples were identified

ASSESSMENT OF MICROPLASTICS IN PERSONAL CARE PRODUCTS BY MICROSCOPIC METHODS AND VIBRATIONAL SPECTROSCOPY

Primary microplastics, known as microbeads (μBs), are found in personal care and cosmetic products (PCCPs) being used as an ingredient for physical abrasion on human body surface. Due to the fact that μBs has sizes less than 0.8 mm, sometimes even less than 0.1 mm, they can be ingested by many organisms, being transmitted in the food chain. The development of a method for isolating the microplastics from the matrix of branded PCCPs samples (i.e., shower gel, body spray) using ultrasound technique at constant temperature and pressure, high-performance vacuum filtration method with various high-purity filtration membranes (e.g., cellulose) was the first objective of this study. The second objective was to combine vibrational spectroscopy techniques (i.e., Fourier-transform infrared μ-spectroscopy) with optical microscopy, to investigate the morphology and chemical composition of MPs. Microplastics were identified in all five brands of analyzed products. Thus, an average value of 420 μBs/100 g in shower gel and 200 μBs/100 mL in body sprays was determined; the identified colors were black (mostly), blue, yellow, brown, green, and red. The observed sizes varied from tens of micrometers to a few centimeters in some cases and the thickness reached 10 μm. From visual (microscopy) and chemical (μ-FTIR spectroscopy) point of view the structure was mostly like polypropylene fibers, smaller and having glossy mate appearance

Wood preservation with gold hydroxyapatite system

Abstract Over centuries, the external factors such as fire, low temperature, light or microbiological agents, act on the wood and induce some degradation processes, sometimes irreversible, identified by discoloration, fragility and unsightly appearance. Although there are numerous literature reports about different nanomaterials used for preservation and restoration of wood surfaces (calcium hydroxides, magnesium hydroxides, hydroxyapatite, or even organic resins as Paraloid B72), in this paper it is proposed a new system—gold hydroxyapatite (AuHAp), tested on the hazelnut wood samples (young and aged specimens), as a new solution for preservation of some wooden artifacts. This paper addresses a broad range of analytical methods: X-ray diffraction, UV–Vis spectrophotometry, Fourier transformed infrared spectroscopy, Raman spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, chromatic parameters and hardness test. Also, humidity sorption/desorption measurements are used for humidity sorption and desorption evaluation. The adsorption and desorption tests determined the hydroscopic sorption properties of the wood specimens by measuring the mass of the specimens in equilibrium with air at a specific temperature and RH. All the results concluded that after the application of the new system on the hazelnut wood surface, a well distributed and uniform layer consisting from AuHAp systems with a network aspect are observed, which covers the wood vessels and fibers, filling the voids and stopping the wood weathering process, more accentuated at aged wood than at the young species

Aluminum Oxide Ceramic Coatings on 316l Austenitic Steel Obtained by Plasma Electrolysis Oxidation Using a Pulsed Unipolar Power Supply

AISI 316 steel has good corrosion behavior and high-temperature stability, but often prolonged exposure to temperatures close to 700 °C in aggressive environments (e.g., in boilers and furnaces, in nuclear installations) can cause problems that lead to accelerated corrosion degradation of steel components. A known solution is to prepare alumina ceramic coatings on the surface of stainless steel. The aim of this study is to obtain aluminum oxide ceramic coatings on 316L austenitic steel, by Plasma Electrolysis Oxidation (PEO), using a pulsed unipolar power supply. The structures obtained by PEO under various experimental conditions were characterized by XPS, SEM, XRD, and EDS analyses. The feasibility was proved of employing PEO in NaAlO2 aqueous solution using a pulsed unipolar power supply for ceramic–like aluminum oxide films preparation, with thicknesses in the range of 20–50 μm, and a high content of Al2O3 on the surface of austenitic stainless steels

Geochemical Responses to Natural and Anthropogenic Settings in Salt Lakes Sediments from North-Eastern Romanian Plain

Chemical analysis was performed on sediment core samples collected from three salt lakes, Amara Lake, Caineni Lake, and Movila Miresii Lake, located in the northeast of the Romanian Plain. The concentration of 10 main elements, 6 heavy metals (HMs), 8 rare earth elements (REEs), and 10 trace elements (TEs)—determined using neutron activation analysis (NAA)—showed variability dependent on the depth sections, lake genesis and geochemical characteristics (oxbow, fluvial harbor/liman and loess saucer type). The assessment of pollution indices (contamination factor, pollution load index, geoaccumulation index, and enrichment factor) highlighted low and moderate degrees of contamination for most of the investigated elements. Principal component analysis (PCA) extracted three principal components, explaining 70.33% (Amara Lake), 79.92% (Caineni Lake), and 71.42% (Movila Miresii Lake) of the observed variability. The principal components extracted were assigned to pedological contribution (37.42%—Amara Lake, 55.88%—Caineni Lake, and 15.31%—Movila Miresii Lake), salts depositions (due to the lack of a constant supply of freshwater and through evaporation during dry periods), atmospheric deposition (19.19%—Amara Lake, 13.80%—Caineni Lake, and 10.80%—Movila Miresii Lake), leaching from soil surface/denudation, rock weathering, and mixed anthropogenic input (e.g., agricultural runoff, wastewater discharges) (13.72%—Amara Lake, 10.24%—Caineni Lake, and 45.31%—Movila Miresii Lake)

Multi-Analytical Characterization of Corvins’ Castle—Deserted Tower. Construction Materials and Conservation Tests

The aim of this paper is to analyze the construction materials (mortars) of an architectural monument (Deserted Tower (Lilly Tower) from Corvins’ Castle, Romania). The mortars were characterized following a multidisciplinary approach, combining macroscopic observation with petrographic microscopy, mineralogical analysis (X-ray diffraction) and elemental analysis (X-ray fluorescence), hydric properties, and color of representative samples of the monument. The results revealed the use of gypsum mortars (produced by lumps with higher Fe content), with minor concentrations of crystalline dolomites of the Southern Carpathians, calcite, and quartz. The materials’ effective porosity and their water absorption capacity were high. A possible solution to consolidate the damaged area with some consolidation products (hydroxyapatite carbonate and its derivatives with Ag and Sr) was investigated, too. The interactions between the mortar’s specimens and the effectiveness of the consolidation treatments were evaluated by physico-chemical analyses (molecular structure by X-ray powder diffraction (XRPD), wavelength dispersive X-ray fluorescence (WDXRF), dynamic light scattering (DLS)), morphological characterization by microscopic techniques as SEM-EDS, TEM, and physical and mechanical investigations (peeling test and compressive strength). Results were drawn based on historical, in situ observations, and analytical data, and put into evidence the composition, high weathering degree, and the possibility to surface consolidate with Sr-CHAp

Novel Structures of Functionalized Graphene Oxide with Hydrazide: Characterization and Bioevaluation of Antimicrobial and Cytocompatibility Features

Graphite was oxidized to graphene oxide and activated by thionyl chloride, for further covalently linking three hydrazides with potential biological activity. The obtained materials were characterized by scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared and Raman spectroscopies. The presence of various functional groups specific to graphene oxide (GO) functionalized with different hydrazides was confirmed by spectral data. The ratio between D- and G-bands, observed in Raman spectra, allowed for an evaluation of the disorder degree and the mean crystallite size of the samples. The micrographs highlighted that the samples lead to the occurrence of disorders, probably caused by the sp3 carbons, the formation of oxygen-containing functional groups in the basal planes, and by various structural defects. The new graphene oxide–hydrazide derivatives were tested for their antimicrobial and cytotoxicity activity. Their antimicrobial activity against planktonic and biofilm-embedded cells was inferior to that of free hydrazides, except for GO-3 against planktonic Escherichia coli and GO-2 against Pseudomonas aeruginosa biofilm, demonstrating that further optimization is needed to be able to exploit the huge potential of GO for developing potent antimicrobials