DETECTION OF HEAVY METALS FROM MOLLUSCS SHELLS

This work presents aspects regarding some heavy metals (Cd, Pb, Cu and Zn) concentration in shells of different molluscs (Mytilus galloprovincialis, Rapana thomasiana, Mya arenaria, Scapharca) collected from the Romanian Black Sea Coast. The heavy metals were analysed using atomic absorption spectrometry

Research on the Phenotypic Characterization of Mrsa Strains Isolated from Animals

Keywords: chromogen, methicillin, MRSA, resistanceIntroduction: Currently, both in staphylococci isolated from animals with different diseases, as well as in humans, the MRSA strains (Methicillin Resistant S. aureus) are monitored, as the methicillin resistance is associated with the resistance to other antibiotic groups.Methicillin resistance is encoded by mec staphylococcal chromosomal cassettes (SCCmec), which are islands of resistance. These strains can be identified by molecular biology tests and tests that reveal several phenotypic characteristics.The research was made in order to characterize and identify phenotypically the MRSA staphylococci strains isolated from animals.Materials and Methods: Researches were made on 240 coagulase positive and coagulase negative strains of staphylococci. Mannitol fermentation was tested on Champan medium, free coagulase was revealed on Baird-Parker medium and to identify S. aureus subsp. aureus was used the chromogenic medium Chromatic Staph.Methicillin-resistant strains were detected by disc diffusion method, using biodiscs with methicillin, oxacillin and cefoxitin. Also, to identify the MRSA strains, was used the chromogenic medium Chromatic MRSA.Results: The isolates were positive to mannitol and produced complete haemolysis or were unhaemolytic. A total of 44 strains produced free coagulase on Baird-Parker medium, considered coagulase positive strains, while 196 were coagulase negative strains.The isolates conducted differently to methicillin: 22,08% of strains were resistant, 51,25% of strains were susceptible and 26,66% had intermediate resistance, while the resistant strains to oxacillin were 42,91%.The increased frequency of methicillin-resistant strains of staphylococci and, particularly, MRSA strains, determined using the cefoxitin disk diffusion test, which is more reliable than methicillin and oxacillin.On the MRSA chromogenic medium, the methicillin-resistant strains of staphylococci formed colonies with pigment from mauve to orange mauve.Conclusion: The obtained results by disk diffusion test on resistance patterns to 3 beta-lactams, resistant to penicillinase, indicated a different frequency of the resistant strains to these antibiotics.Cefoxitin disk diffusion test revealed a frequency of 2,51% of resistant strains, that can be considered MRSA strains

INVESTIGATION OF HEAVY METALS FROM SOME ALIMENTARY PRODUCTS

The presence in high amount of organic pollutants and heavy metals in environmentrepresents a potential danger for human health and for environment too. This workpresents aspects regarding the pollution with heavy metals (Cd, Pb, Cu and Zn) of some food products: caw milk, caw cheese and caw meat. The samples analysed were collected from some housekeeping of Lumina (Constanta). The heavy metals were analysed using atomic absorption spectrometry

Cervical Cancer Mortality in Romania: Trends, Regional and Rural–Urban Inequalities, and Policy Implications

Background and Objectives: Despite being largely preventable, cervical cancer mortality still remains an important public health problem globally, in Europe, and in Romania. The European Union member states are urged to implement systematic, population-based screenings for cervical cancer, but the programs developed by the countries remain very heterogeneous. This study aimed to investigate the differences in cervix cancer mortality between Romania and EU and within Romania over the last two decades and to reveal the major sources of inequalities and the policy implications. Materials and Methods: We analyzed the number of deaths and the mortality rates by cervical cancer, standardized using the direct method, over two decades (2001–2016 for the EU, and 2001–2019 for the national and sub-national analyses). Trends, mortality reduction over the years, and mortality differences at the beginning and end of the time interval have been calculated for the EU and Romania, at national and sub-national levels (rural–urban and regions). Results: Our results revealed differences in cervical cancer mortality between Romania and EU and within Romania (among regions and rural–urban areas). These differences used to be very high in the past and are still persisting. Conclusions: The country should revisit its national cervical cancer screening program, which has been implemented for many years, but with a very limited participation rate. Due to the similar problems existing in Central-Eastern Europe, targeted support from the EU for the members from this geographical area could contribute to the minimization of differences in cervical cancer mortality among the EU members

Imagistic evaluation of direct dental restoration: En face OCT versus SEM and microCT

There are several methods known which are used to assess the quality of direct dental restorations, but most of them are invasive. These lead to the destruction of the probes and often no conclusion could be drawn in respect to the existence of any microleakage in the investigated areas of interest. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. Using an en-face version of OCT, we have recently demonstrated real time thorough evaluation of quality of dental fillings. The purpose of this in vitro study was to validate the en face OCT imagistic evaluation of direct dental restoration by using scanning electron microscopy (SEM) and microcomputer tomography (μCT). Teeth after several treatment methods are imaged in order to detect material defects and to asses the marginal adaptation at the dental hard tissue walls. SEM investigations evidenced the nonlinear aspect of the interface between the filling material and the buccal and lingual walls in some samples. The results obtained by μCT revealed also some material defects inside the fillings and at the interfaces with the rootcanal walls. The advantages of the OCT method consist in non-invasiveness and high resolution. En face OCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region

Early characterization of occlusal overloaded cervical dental hard tissues by en face optical coherence tomography

Early diagnosis of occlusal overload is an important issue in dental medicine. The high occlusal forces can cause irreversible damage to the dental hard tissues. Our study proposes the early microstructural characterization of occlusal overloaded bicuspids, with abnormal crown morphology, by en face optical coherence tomography (eFOCT). The dental samples were investigated using an eFOCT system operating at 1300 nm in B-scan and C-scan mode. The eFOCT images obtained from these teeth visualized cracks, which didn't reach the tooth surface. The μCT and histological images confirmed the microstructural defects identified on eFOCT images. In conclusion, eFOCT is a promising imaging method for the early diagnosis of occlusal overload on bicuspids with normal crown morphology and for the prophylaxis of dental wear

Luminescence, Paramagnetic, and Electrochemical Properties of Copper Oxides-Decorated TiO₂/Graphene Oxide Nanocomposites

The properties of newly synthesized Cu2O/CuO-decorated TiO2/graphene oxide (GO) nanocomposites (NC) were analyzed aiming to obtain insight into their photocatalytic behavior and their various applications, including water remediation, self-cleaning surfaces, antibacterial materials, and electrochemical sensors. The physico-chemical methods of research were photoluminescence (PL), electron paramagnetic resonance (EPR) spectroscopy, cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The solid samples evidenced an EPR signal that can be attributed to the oxygen-vacancy defects and copper ions in correlation with PL results. Free radicals generated before and after UV-Vis irradiation of powders and aqueous dispersions of Cu2O/CuO-decorated TiO2/GO nanocomposites were studied by EPR spectroscopy using two spin traps, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) and CPH (1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine), to highlight the formation of hydroxyl and superoxide reactive oxygen species, respectively. The electrochemical characterization of the NC modified carbon-paste electrodes (CPE) was carried out by CV and DPV. As such, modified carbon-paste electrodes were prepared by mixing carbon paste with copper oxides-decorated TiO2/GO nanocomposites. We have shown that GO reduces the recombination process in TiO2 by immediate electron transfer from excited TiO2 to GO sheets. The results suggest that differences in the PL, respectively, EPR data and electrochemical behavior, are due to the different copper oxides and GO content, presenting new perspectives of materials functionalization

Analysis of dental abfractions by optical coherence tomography

Aim and objectives. Abfraction is the pathological loss of cervical hard tooth substance caused by biomechanical overload. High horizontal occlusal forces result in large stress concentrations in the cervical region of the teeth. These stresses may be high enough to cause microfractures in the dental hard tissues, eventually resulting in the loss of cervical enamel and dentin. The present study proposes the microstructural characterization of these cervical lesions by en face optical coherence tomography (eFOCT). Material and methods: 31 extracted bicuspids were investigated using eFOCT. 24 teeth derived from patients with active bruxism and occlusal interferences; they presented deep buccal abfractions and variable degrees of occlusal pathological attrition. The other 7 bicuspids were not exposed to occlusal overload and had a normal morphology of the dental crowns. The dental samples were investigated using an eFOCT system operating at 1300 nm (B-scan at 1 Hz and C-scan mode at 2 Hz). The system has a lateral resolution better than 5 μm and a depth resolution of 9 μm in tissue. OCT images were further compared with micro - computer tomography images. Results. The eFOCT investigation of bicuspids with a normal morphology revealed a homogeneous structure of the buccal cervical enamel. The C-scan and B-scan images obtained from the occlusal overloaded bicuspids visualized the wedge-shaped loss of cervical enamel and damage in the microstructure of the underlaying dentin. The high occlusal forces produced a characteristic pattern of large cracks, which reached the tooth surface. Conclusions: eFOCT is a promising imaging method for dental abfractions and it may offer some insight on the etiological mechanism of these noncarious cervical lesions

Root canal filling evaluation using optical coherence tomography

Endodontic therapy consists in cleaning and shaping the root canal system, removing organic debris and sealing the intra-canal space with permanent filling materials. The purpose of this study was to evaluate various root canal fillings in order to detect material defects, the marginal adaptation at the root canal walls and to assess the quality of the apical sealing. 21 extracted single-root canal human teeth were selected for this study. We instrumented all roots using NiTi rotary instruments. All canals were enlarged with a 6% taper size 30 GT instrument, 0,5 mm from the anatomical apex. The root canals were irrigated with 5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid (EDTA). After the instrumentation was completed, the root canals were obturated using a thermoplasticizable polymer of polyesters. In order to assess the defects inside the filling material and the marginal fit to the root canal walls, the conebeam micro-computed tomography (CBμCT) was used first. After the CBμCT investigation, time domain optical coherence tomography working in en face mode (TDefOCT) was employed to evaluate the previous samples. The TDefOCT system was working at 1300 nm and was doubled by a confocal channel at 970 nm. The results obtained by CBμCT revealed no visible defects inside the root-canal fillings and at the interfaces with the root-canal walls. TDefOCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region