Serbian traditional goat cheese : physico-chemical, sensory, hygienic and safety characteristics

Research Areas: MicrobiologyThis research project aimed to investigate the physico-chemical, sensory, hygienic and safety characteristics of raw goat milk, whey, brine and traditional goat cheese during the ripening period of 28 days. Physico-chemical parameters included the determination of dry matter, fat, ash, protein, pH, water activity and NaCl content. The presence of Enterobacteriaceae and fungi was estimated on milk and cheese samples, and a sensory panel evaluated the products’ features and acceptability during ripening. The results show that the cheese under study belongs to the acid full-fat cheese group. A consumer panel attributed high scores to the goat cheese, until the 21st day of ripening. After this period, the overall features altered significantly, including augmented bitterness, odor intensification and the development of molds on the surface. The presence of fungi, associated with Enterobacteriaceae, suggests that the hygiene of the production processes needs to be improved. Regarding microbial safety, the detection of putative pathogens and antibiotic resistances recommend an active surveillance of traditional foods to avoid foodborne infections and/or the dissemination of resistant microorganisms along the food chaininfo:eu-repo/semantics/publishedVersio

Results of an interlaboratory comparison for characterization of Pt nanoparticles using single-particle ICP-TOFMS

This study describes an interlaboratory comparison (ILC) among nine (9) laboratories to evaluate and validate the standard operation procedure (SOP) for single-particle (sp) ICP-TOFMS developed within the context of the Horizon 2020 project ACEnano. The ILC was based on the characterization of two different Pt nanoparticle (NP) suspensions in terms of particle mass, particle number concentration, and isotopic composition. The two Pt NP suspensions were measured using icpTOF instruments (TOFWERK AG, Switzerland). Two Pt NP samples were characterized and mass equivalent spherical sizes (MESSs) of 40.4 ± 7 nm and 58.8 ± 8 nm were obtained, respectively. MESSs showed <16% relative standard deviation (RSD) among all participating labs and <4% RSD after exclusion of the two outliers. A good agreement was achieved between the different participating laboratories regarding particle mass, but the particle number concentration results were more scattered, with <53% RSD among all laboratories, which is consistent with results from previous ILC studies conducted using ICP-MS instrumentation equipped with a sequential mass spectrometer. Additionally, the capabilities of sp-ICP-TOFMS to determine masses on a particle basis are discussed with respect to the potential for particle density determination. Finally, because quasi-simultaneous multi-isotope and multi-element determinations are a strength of ICP-TOFMS instrumentation, the precision and trueness of isotope ratio determinations were assessed. The average of 1000 measured particles yielded a precision of below ±1% for intensity ratios of the most abundant Pt isotopes, i.e.194Pt and 195Pt, while the accuracy of isotope ratios with the lower abundant isotopes was limited by counting statistics

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Improving detection capability for single particle inductively coupled plasma mass spectrometry with microdroplet sample introduction

Single particle inductively coupled plasma mass spectrometry (sp-ICPMS) is an attractive technique for fast measurement of elemental composition, mass and particle number concentration (PNC) of metal containing nanoparticles (NPs). In order to investigate NPs <10 nm using ICPMS, low instrumental background and high detection efficiency are primary requirements. This study evaluated the performance of a sector-field ICPMS with standard and enhanced sensitivity (“Jet”) vacuum interfaces with different sample introduction setups: conventional pneumatic nebulization with (DSN) and without aerosol desolvation (PN) and microdroplet generation (MDG). Additionally, the influence of nitrogen gas as an addition to a dry aerosol was studied. In this study, transport efficiencies (TEs) and detection efficiencies (DEs) are determined for the different instrumental setups. Gold NP suspensions were analysed and evaluated for PNC and size. Applying counting statistics, the size limit of detection (LODsize) of gold nanoparticles (Au NPs) was estimated to be 6.1 nm and 4.7 nm for PN and MDG with the standard interface, and 3.6 nm and 3.1 nm for DSN and MDG with the “Jet” interface and nitrogen addition, respectively. Additionally, DEs for various elements were determined. 11 isotopes (27Al, 47Ti, 63Cu, 107Ag, 111Cd, 115In, 133Cs, 140Ce, 193Ir, 197Au, and 238U) were measured at a mass resolving power (MRP) of 300 while an MRP of 4000 was used for 56Fe and 66Zn. DEs obtained for the conventional nebulization system with a spray chamber (PN) were in the range of 10−4 to 10−2 counts per atom (low resolution) and 10−6 to 10−5 counts per atom (medium resolution), while significant improvement in DE was obtained for the MDG setup with the “Jet” interface and nitrogen addition resulting in the range of 10−2 to 10−1 counts per atom (low resolution) and 10−4 to 10−3 counts per atom (medium resolution). The enhancement in DE was most pronounced for isotopes of lower m/z indicating reduced mass discrimination of the “Jet” interface with nitrogen gas added to the sample aerosol. The corresponding LODSIZE could thus be decreased by 10 or 2 times for example for Al- and Au-containing NPs, respectively. At the same time the use of an MDG for sample introduction allowed for 98.5% TE in the analyses of NP suspensions, while a TE of 10% (PN) or 23% (DSN) was obtained with pneumatic nebulizers.ISSN:0267-9477ISSN:1364-554

Direct analysis of nanoparticles in organic solvents by ICPMS with microdroplet injection

In recent years, the capabilities for characterizing inorganic nanoparticles (NPs) in aqueous solvents with respect to their elemental composition, mass and particle number concentration have been expanded using single particle inductively coupled plasma mass spectrometry (sp-ICPMS). However, colloidal NPs with high monodispersity, size, shape and surface chemistry control are frequently synthesized using hot-injection methods, utilizing hydrophobic organic ligands which are only soluble in non-polar organic solvents. Due to several instrumental limitations, suspensions in organic solvents are not commonly analysed by sp-ICPMS. In this study, we investigated the direct introduction of organic solvents into an ICPMS using a microdroplet generator. With this configuration the solvent load in the ICP is substantially reduced and soot formation, causing instrumental drift, was minimized while maintaining a transport efficiency (TE) of 100%. Furthermore, the effect of different vacuum interface configurations and the addition of oxygen or nitrogen on the detection efficiency (DE) and instrumental background signals was investigated for Al, Si, Ti, Fe Cu, Ag, Cd, and Pb. The highest DE was obtained for a “Jet” interface with the addition of nitrogen at a flow rate of 10 mL/min, resulting in an increase by a factor of 2-8 depending on the element. The lowest detectable mass, based on counting statistics, was 1.4 ag for Pb, which corresponds to a size of 6.1 nm of a pure metallic NP. The approach can not only be used for NP characterization, but also holds promise for the sensitive determination of trace elements in organic solventsISSN:0267-9477ISSN:1364-554

Predictive Markers for Malignant Urothelial Transformation in Balkan Endemic Nephropathy: A Case–Control Study

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial disease frequently accompanied by urothelial carcinoma (UC). In light of the increased UC incidence and the markers observed in BEN patients with developed UC, the aim of the current case&ndash;control study is to assess survivin, p53 protein, growth factors and receptors (VEGF, VEGFR1, IGF I, IGF-1R and IGFBP5), tumor marker (TF)/CD142, circulating soluble Fas receptor and neopterin, as potentially predictive markers for UC in patients with BEN (52 patients), compared to healthy, age-matched subjects (40). A threefold increase was registered in both circulating and urinary survivin level in BEN patients. Especially noticeable was the ratio of U survivin/U Cr level five times the ratio of BEN patients associated with standard renal markers in multivariate regression models. The concentrations of VEGF, VEGFR1, (TF)/CD142, (sFas) were not significantly different in BEN patients, while urinary/plasma level demonstrated a significant decrease for VEGF. The levels of IGF I, IGFBP5 and IGF-1R were significantly reduced in the urine of BEN patients. Plasma concentration of neopterin was significantly higher, while urinary neopterin value was significantly lower in BEN patients compared to healthy controls, which reflected a significantly lower urine/plasma ratio and low local predictive value. As BEN is a slow-progressing chronic kidney disease, early detection of survivin may be proposed as potential predictor for malignant alteration and screening tool in BEN patients without the diagnosis of UC

Validation of the Study Burnout Inventory and the Copenhagen Burnout Inventory for the use among medical students

ObjectivesThe aim of this study was to assess the validity and reliability of the Serbian versions of the Copenhagen Burnout Inventory (CBI) and the Study Burnout Inventory (SBI) among fifth-year medical students at 5 universities in Serbia.Material and MethodsThe study included 573 fifthyear medical students at 5 universities in Serbia. The research instrument consisted of SBI and CBI. The reliability of these instruments was assessed using an internal consistency measure (Cronbach’s α), an intra-class coefficient (ICC) and factor analysis.ResultsCronbach’s α for SBI was 0.83, including for exhaustion 0.73, for cynicism 0.70, and for inadequacy 0.48. The test-retest reliability (ICC) was 0.75. Cronbach’s α for personal burnout on CBI was 0.89, for the faculty-related burnout 0.86, and for the faculty-members-related burnout 0.92. Cronbach’s α for CBI was 0.93. The factor analysis for SBI showed 2 factors and for CBI 3 factors.ConclusionsThis study revealed that the Serbian versions of both SBI and CBI could be used for the assessment of burnout in this population