Application of fluorescence spectroscopy and chemometric models for the detection of vegetable oil adulterants in Maltese virgin olive oils.

Fluorescence spectrometry, combined with principle component analysis, partial least-squares regression (PLSR) and artificial neural network (ANN), was applied for the analysis of Maltese extra virgin olive oil (EVOO) adulterated by blending with vegetable oil (corn oil, soybean oil, linseed oil, or sunflower oil). The novel results showed that adjusted PLSR models based on synchronised spectra for detecting the % amount of EVOO in vegetable oil blends had a lower root mean square error (0.02-6.27%) and higher R2 (0.983-1.000) value than those observed when using PLSR on the whole spectrum. This study also highlights the use of ANN as an alternative chemometric tool for the detection of olive oil adulteration. The performance of the model generated by the ANN is highly dependent both on the type of data input and the mode of cross validation; for spectral data which had a variable importance plot value > 0.8 the excluded row cross validation was more appropriate while for complete spectral analysis k-fold or CV-10 was more appropriate.

Forward Modeling of Coronal Mass Ejection Flux Ropes in the Inner Heliosphere with 3DCORE.

Forecasting the geomagnetic effects of solar storms, known as coronal mass ejections (CMEs), is currently severely limited by our inability to predict the magnetic field configuration in the CME magnetic core and by observational effects of a single spacecraft trajectory through its 3-D structure. CME magnetic flux ropes can lead to continuous forcing of the energy input to the Earth's magnetosphere by strong and steady southward-pointing magnetic fields. Here we demonstrate in a proof-of-concept way a new approach to predict the southward field B z in a CME flux rope. It combines a novel semiempirical model of CME flux rope magnetic fields (Three-Dimensional Coronal ROpe Ejection) with solar observations and in situ magnetic field data from along the Sun-Earth line. These are provided here by the MESSENGER spacecraft for a CME event on 9-13 July 2013. Three-Dimensional Coronal ROpe Ejection is the first such model that contains the interplanetary propagation and evolution of a 3-D flux rope magnetic field, the observation by a synthetic spacecraft, and the prediction of an index of geomagnetic activity. A counterclockwise rotation of the left-handed erupting CME flux rope in the corona of 30° and a deflection angle of 20° is evident from comparison of solar and coronal observations. The calculated Dst matches reasonably the observed Dst minimum and its time evolution, but the results are highly sensitive to the CME axis orientation. We discuss assumptions and limitations of the method prototype and its potential for real time space weather forecasting and heliospheric data interpretation.

Applying Magnetic Curvature to MMS Data to Identify Thin Current Sheets Relative to Tail Reconnection.

Thin current sheets (TCSs) have been postulated to be a necessary precondition for reconnection onset. Magnetic reconnection X-lines in the magnetotail have been observed to be more common duskward of midnight. We take advantage of the MMS tetrahedral formation during the 2017-2020 MMS tail seasons to calculate the thickness of the cross-tail neutral sheet relative to ion gyroradius. While a similar technique was applied to Cluster data, current sheet thickness over a broader range of radial distances has not been robustly explored before this study. We compare our analysis to recent theories regarding mechanisms of tail current sheet thinning and to recent simulations. We find MMS spent more than twice as long in ion-scale TCSs in the pre-midnight sector than post-midnight, despite nearly even plasma sheet dwell time. The dawn-dusk asymmetry in the distribution of Ion Diffusion Regions, as previously reported in relation to regions of TCSs, is also analyzed.

Seasonal and diurnal variations of Kelvin-Helmholtz Instability at terrestrial magnetopause.

Kelvin-Helmholtz Instability is ubiquitous at Earth's magnetopause and plays an important role in plasma entry into the magnetosphere during northward interplanetary magnetic fields. Here, using one solar cycle of data from NASA THEMIS (Time History of Events and Macro scale Interactions during Substorms) and MMS (Magnetospheric Multiscale) missions, we found that KHI occurrence rates show seasonal and diurnal variations with the rate being high near the equinoxes and low near the solstices. The instability depends directly on the Earth's dipole tilt angle. The tilt toward or away from the Sun explains most of the seasonal and diurnal variations, while the tilt in the plane perpendicular to the Earth-Sun line explains the difference between the equinoxes. The results reveal the critical role of dipole tilt in modulating KHI across the magnetopause as a function of time, highlighting the importance of Sun-Earth geometry for solar wind-magnetosphere interaction and for space weather.

Porphyromonas gingivalis Outer Membrane Vesicles Increase Vascular Permeability.

Periodontitis is increasingly associated with increased risk of cardiovascular and other systemic diseases. The Gram-negative anaerobe, Porphyromonas gingivalis, is a key periodontal pathogen, and several lines of evidence link the presence of this bacterium in the circulation with vascular disease. The outer membrane vesicles (OMVs) produced by P. gingivalis have been shown to play a role in periodontitis, although, to date, little is known about their interaction with the vasculature; therefore, this study assessed the effects of P. gingivalis OMVs on the endothelium. OMVs were isolated from wild-type strain W83 and the gingipain-deficient strain ΔK/R-ab. Immunoblotting along with cryo-EM showed gingipain expression in W83 but not ΔK/R-ab-derived OMVs, where gingipains were localized to the cell wall surface. Confluent endothelial cell monolayers infected with either W83 or W83-derived OMV displayed significantly increased dextran permeability over those infected with ΔK/R-ab or its OMV. Moreover, W83-derived OMVs induced significantly more vascular disease in a zebrafish larvae systemic infection model over 72 h compared to those injected with gingipain-deficient OMVs or controls. In line with these data, human microvascular endothelial cells (HMEC-1) displayed an OMV-associated, gingipain-dependent decrease in cell surface levels of the intercellular adhesion molecule PECAM-1 (CD31) when examined by flow cytometry. These data show, for the first time, that OMVs from P. gingivalis mediate increased vascular permeability, leading to a diseased phenotype both in vitro and in vivo. Moreover, these data strongly implicate gingipains present on the OMV surface in mediating these vascular events, most likely via a mechanism that involves proteolytic cleavage of endothelial cell-cell adhesins such as PECAM-1. These data provide important evidence for the role of bacterial-derived OMVs in mediating systemic disease.

Standardization of antimicrobial testing of dental devices.

OBJECTIVE: Dental device is a very broad term that can be used to include any foreign material or product that is introduced in the host oral cavity to replace missing tissues. These devices are subjected to different environments which include dental hard tissues, tissue fluids, blood and saliva. All dental devices are continuously challenged microbiologically and a number of failures in clinical management are related to microbial colonization. Thus, the assessment of the antimicrobial properties of dental devices are extremely important. In this paper, a classification of dental devices is being proposed. This classification distinguishes the devices based on whether they are implantable or not, and also sub-classified based on their specific application and the substrate receiving the device. METHODS AND RESULTS: A literature search was conducted to identify how dental devices have been tested with relation to the microbial strains used and whether the testing has been performed in isolation or reported with other relevant tests such as material characterization and biological activity. The results of the literature review were analyzed and recommendations for antimicrobial testing of dental devices are proposed. These recommendations include the need for the setting up of pre-testing parameters such as ageing and the details of the pre-testing sterilization procedures, as these may affect the material chemistry and the specification for antimicrobial testing to be done with specific single strains or polymicrobial that are native to the region where the device is located are also suggested. Testing can be undertaken in vitro, ex vivo and in vivo. Since the antimicrobial and biological activities influence/condition one another and the material chemistry may affect both the antimicrobial and biological testing this document also makes recommendations regarding biological assessment which can be carried out in isolation or integrated with the microbiological testing and also material testing methods including chemical and physical characterization of bulk, surface, eluted and degraded materials as well as physical characterization methods. SIGNIFICANCE: The level of standardization of antimicrobial testing for the dental devices needs to be based on the device location and host interaction in order to increase the clinical applicability of the mentioned tests.

Characteristics of Minor Ions and Electrons in Flux Transfer Events Observed by the Magnetospheric Multiscale Mission.

In this study, the ion composition of flux transfer events (FTEs) observed within the magnetosheath proper is examined. These FTEs were observed just upstream of the Earth's postnoon magnetopause by the National Aeronautics and Space Administration (NASA) Magnetospheric Multiscale (MMS) spacecraft constellation. The minor ion characteristics are described using energy spectrograms, flux distributions, and ion moments as the constellation encountered each FTE. In conjunction with electron data and magnetic field observations, such observations provide important contextual information on the formation, topologies, and evolution of FTEs. In particular, minor ions, when combined with the field-aligned streaming of electrons, are reliable indicators of FTE topology. The observations are also placed (i) in context of the solar wind magnetic field configuration, (ii) the connection of the sampled flux tube to the ionosphere, and (iii) the location relative to the modeled reconnection line at the magnetopause. While protons and alpha particles were often depleted within the FTEs relative to the surrounding magnetosheath plasma, the He+ and O+ populations showed clear enhancements either near the center or near the edges of the FTE, and the bulk plasma flow directions are consistent with magnetic reconnection northward of the spacecraft and convection from the dayside toward the flank magnetopause.

National hand hygiene campaigns in Europe, 2000-2009.

Hand hygiene represents the single most effective way to prevent healthcare-associated infections. The World Health Organization, as part of its First Global Patient Safety Challenge, recommends implementation of multi-faceted strategies to increase compliance with hand hygiene. A questionnaire was sent by the European Centre for Disease Prevention and Control to 30 European countries, regarding the availability and organisation of their national hand hygiene campaigns. All countries responded. Thirteen countries had organised at least one national campaign during the period 2000-2009 and three countries were in the process of organising a national campaign. Although the remaining countries did not have a national campaign, several reported regional and local hand hygiene activities or educational resources on national websites.

Real-time PCR on the first galactomannan-positive serum sample for diagnosing invasive aspergillosis in liver transplant recipients.

Invasive aspergillosis (IA) is a life-threatening complication of liver transplantation. Detection of circulating galactomannan (GM) in serum samples is a method to improve the microbiological diagnosis in patients at risk for IA. However, the assay is hampered by false-positive results. The search for circulating Aspergillus DNA in the first GM-positive sample could improve the specificity of the test. Among 484 liver transplant recipients followed in a single center over 4 years, 25 patients had at least 1 GM-positive serum sample. The threshold of GM positivity was a ratio >or=1. These 25 patients were classified by the clinicians as probable IA (n=11), possible IA (n=2), and no IA (n=12) using the EORTC/MSG criteria with blinding to the polymerase chain reaction (PCR) results. After 1 mL aliquots of the first GM-positive serum sample were thawed, 2 independent DNA extractions were performed using the MagNA Pure Compact apparatus. Real-time amplification targeted at Aspergillus fumigatus mitochondrial DNA was performed on 10 microL of the final eluate in duplicate in the 2 independent DNA extractions using a LightCycler instrument. A sample was considered positive when the crossing point was

Allele frequencies of 14 STR loci in the population of Malta.

Allele frequencies of 14 STR loci (D13S317, D16S539, D2S1338, vWA, TPOX, D18S51, D5S818, FGA, D8S1179, D21S11, D7S820, CSF1PO, TH01 and D3S1358) observed in the population of Malta are being reported. Polymerase chain reaction (PCR) amplification using the AmpFl STR Identifiler kit was performed in a random sample of 157 subjects (314 chromosomes). Markers D2S1338, D18S51 and FGA had the highest power of discrimination (PD) values while TPOX was the least informative marker. Allele frequencies observed in the Maltese population were also compared with those of other populations from the Mediterranean region, Europe and Africa. Our data is useful for anthropological and other comparative studies of populations and is powerful for forensic and paternity testing in the Maltese islands.

Electron-scale dynamics of the diffusion region during symmetric magnetic reconnection in space.

Magnetic reconnection is an energy conversion process that occurs in many astrophysical contexts including Earth's magnetosphere, where the process can be investigated in situ by spacecraft. On 11 July 2017, the four Magnetospheric Multiscale spacecraft encountered a reconnection site in Earth's magnetotail, where reconnection involves symmetric inflow conditions. The electron-scale plasma measurements revealed (i) super-Alfvénic electron jets reaching 15,000 kilometers per second; (ii) electron meandering motion and acceleration by the electric field, producing multiple crescent-shaped structures in the velocity distributions; and (iii) the spatial dimensions of the electron diffusion region with an aspect ratio of 0.1 to 0.2, consistent with fast reconnection. The well-structured multiple layers of electron populations indicate that the dominant electron dynamics are mostly laminar, despite the presence of turbulence near the reconnection site.

Antimicrobial activity of ProRoot MTA in contact with blood.

Dental materials based on Portland cement, which is used in the construction industry have gained popularity for clinical use due to their hydraulic properties, the interaction with tooth tissue and their antimicrobial properties. The antimicrobial properties are optimal in vitro. However in clinical use contact with blood may affect the antimicrobial properties. This study aims to assess whether antimicrobial properties of the Portland cement-based dental cements such as mineral trioxide aggregate (MTA) are also affected by contact with blood present in clinical situations. ProRoot MTA, a Portland cement-based dental cement was characterized following contact with water, or heparinized blood after 1 day and 7 days aging. The antimicrobial activity under the mentioned conditions was assessed using 3 antimicrobial tests: agar diffusion test, direct contact test and intratubular infection test. MTA in contact with blood was severely discoloured, exhibited an additional phosphorus peak in elemental analysis, no calcium hydroxide peaks and no areas of bacterial inhibition growth in the agar diffusion test were demonstrated. ProRoot MTA showed limited antimicrobial activity, in both the direct contact test and intratubular infection test. When aged in water ProRoot MTA showed higher antimicrobial activity than when aged in blood. Antimicrobial activity reduced significantly after 7 days. Further assessment is required to investigate behaviour in clinical situations.

[Primary infection with cytomegalovirus: An infectious cause of splenic infarction]. / Primo-infection à cytomégalovirus : une cause infectieuse d'infarctus splénique.

INTRODUCTION: Cytomegalovirus-associated thrombosis has been extensively reported in the medical literature, mainly in immune-compromised patients. However, the association with splenic infarcts has rarely been reported. CASE REPORT: We report a 32-year-old Caucasian and immunocompetent woman who presented with a splenic infarction during a primary infection with CMV. The differential diagnostic ruled out embolic, hematologic, gastrointestinal and coagulation disorders. The outcome was favorable with symptomatic treatment. CONCLUSION: A primary infection with CMV must be added to the diagnostic work-up in the presence of a febrile splenic infarction, especially when it is associated with a biological mononucleosis reaction.

Factors Affecting the Geo-effectiveness of Shocks and Sheaths at 1 AU.

We identify all fast-mode forward shocks, whose sheath regions resulted in a moderate (56 cases) or intense (38 cases) geomagnetic storm during 18.5 years from January 1997 to June 2015. We study their main properties, interplanetary causes and geo-effects. We find that half (49/94) such shocks are associated with interacting coronal mass ejections (CMEs), as they are either shocks propagating into a preceding CME (35 cases) or a shock propagating into the sheath region of a preceding shock (14 cases). About half (22/45) of the shocks driven by isolated transients and which have geo-effective sheaths compress pre-existing southward Bz . Most of the remaining sheaths appear to have planar structures with southward magnetic fields, including some with planar structures consistent with field line draping ahead of the magnetic ejecta. A typical (median) geo-effective shock-sheath structure drives a geomagnetic storm with peak Dst of -88 nT, pushes the subsolar magnetopause location to 6.3 RE, i.e. below geosynchronous orbit and is associated with substorms with a peak AL-index of -1350 nT. There are some important differences between sheaths associated with CME-CME interaction (stronger storms) and those associated with isolated CMEs (stronger compression of the magnetosphere). We detail six case studies of different types of geo-effective shock-sheaths, as well as two events for which there was no geomagnetic storm but other magnetospheric effects. Finally, we discuss our results in terms of space weather forecasting, and potential effects on Earth's radiation belts.

The activity of unloaded gelatin nanoparticles on murine melanoma B16-F0 growth in vivo.

BACKGROUND: Bacillus Calmette-Guérin (BCG) vaccine is a non-specific immunostimulant which has been used clinically in the treatment of melanoma. In this communication, the antimelanoma activity of BCG was related to its fibronectin-binding properties and mimicked using gelatin nanoparticles. MATERIALS AND METHODS: The fibronectin-binding properties of aqueous gelatin solutions, gelatin nanoparticles, BCG vaccine, and PS1 (a glucan extracted from Tice BCG) were compared by an enzyme-linked immunosorbent assay and their ability to suppress murine B16-F0 melanoma in vivo investigated. RESULTS: Aqueous gelatin solutions, gelatin nanoparticles and BCG all bound to fibronectin in vitro. The immunostimulant PS1 did not. In vivo, BCG and gelatin nanoparticles suppressed melanoma growth while PS1 and aqueous gelatin solutions had no effect. CONCLUSIONS: The antimelanoma activity of BCG is not due to the associated immunostimulatory glucan but can be correlated to its fibronectin-binding properties. Since solutions of gelatin have no effect whereas nanoparticles produce total suppression, this suggests a relationship between the volume of the fibronectin-binding entities and their antitumour activity. Thus, gelatin nanoparticles may represent an attractive alternative to the use of BCG vaccine in melanoma treatment.

Geometric considerations of the evolution of magnetic flux ropes.

We use flux conservation and magnetohydrodynamics (MHD) theory to discuss essential differences in the nature of the evolution of two analytical solutions describing magnetic flux tubes evolving in time. The first of these maintains the elongation of the tube, while the second maintains a constant angular extension with respect to a possible pointlike source. In the first case, free expansion of the plasma (density N) occurs only in a direction perpendicular to the flux-tube x axis. In the second case, isotropic evolution is considered. In both cases it is assumed that at initial time t(0) the flux-tube B field is the force-free magnetostatic Lundquist solution, which energetically corresponds to the most stable state for any flux-tube structure. We show that for each case conservation of magnetic flux is enough to establish the scaling with time of the B field. While both expansions may correspond to the evolution of observed flux tubes in the heliosphere, the isotropic expansion appears to capture consistently essential features associated with the actual observations of expanding coronal mass ejections within 30 solar radii. For isotropic expansion of the plasma the force-free nature of the B field is preserved for all time. As an example the MHD solutions are applied to an interplanetary magnetic cloud observed with the spacecraft Wind, which passed Earth's vicinity on June 2, 1998.

Gelatin behaviour in dilute aqueous solution: designing a nanoparticulate formulation.

Although it has been claimed that nanoparticles can be produced from gelatin, a naturally occurring polypeptide, the commercial conversion of animal collagen to gelatin results in a heterogeneous product with a wide molecular-weight range. This is probably responsible for the widely observed variation in the experimental conditions required for nanoparticle formation. In this study, 0.2% w/v aqueous B225 gelatin solutions were incubated under various conditions of time, temperature, pH and ethanol concentration and characterized by both size-exclusion high-performance liquid chromatography (HPLC) and dynamic light scattering. Gelatin was shown to be denatured when the temperature was increased to 37 degrees C (approx.) and the rate of renaturation was optimized over the temperature range 7-20 degrees C at pH 5.0, equivalent to the isoelectric point (IEP). The molecular-weight profile remained unchanged at 37 degrees C (approx.) in the pH range 5-7. When the gelatin solutions were mixed with ethanol, higher-molecular-weight fractions (microgel, delta and zeta fractions, all with molecular weights > 700 kDa) precipitated at ethanol concentrations lower than those required to precipitate the lower molecular weight material ( < 700 kDa), with maximum precipitation occurring close to the isoelectric point (pH 5.0). The molecular weight profile of gelatin in solution is evidently critically affected in a time-dependent manner by both pH and temperature. These two factors influence the noncovalent interactions responsible for the molecular structure of gelatin. The molecular weight profiles, in turn, affect the phase behaviour of gelatin in hydroalcoholic solutions. Systematically investigating the effect of time, temperature, pH and ethanol concentration on the molecular-weight-distribution profile of a gelatin solution enabled a robust method to be developed for the preparation of colloidal dispersions of non-aggregated gelatin nanoparticles 220-250 nm in diameter. This contrasts with the multiparticulate aggregates produced by earlier literature methods.

Delivering the infection control message: a communication challenge.

BACKGROUND: Hospital infection control teams (ICTs) worldwide face a constant challenge to deliver timely information to audiences with specific and diverse information needs. AIM: Our study investigated the communication flow between the ICT and healthcare workers (HCWs) at St Luke's Hospital, Malta, using an exploratory descriptive research design. METHOD: Using a self-administered questionnaire, data were collected from a stratified random sample of nurses (N = 143) and doctors (N = 63) working within inpatient wards; a response rate of 97% was achieved. FINDINGS: HCWs felt most comfortable receiving information from members of their same profession. Information transfer was mainly vertically up and down the hierarchy. Respondents preferred to receive information through educational activities (35%, N = 69) and through face-to-face contact (31%, N = 62). Electronic channels (e-mail and intranet) were ranked least preferable; however, only 41% (N = 81) had regular access to a computer system at work. The majority of respondents 91% (N = 181) trusted the information by the ICT and 60% (N = 118) regarded it as being consistent. Nevertheless, this did not guarantee constant compliance; 54% (N = 106) of respondents implemented IC measures only when they perceived a risk for their health. Greater presence of the ICT on the wards was recommended. CONCLUSION: Notwithstanding the electronic age, the study confirms that face-to-face contact between ICTs and HCWs remains the most effective way of disseminating IC information.

Yeast contamination of kidney, liver and cardiac preservation solutions before graft: need for standardisation of microbial evaluation.

Contamination of preservation solution (PS) with yeasts during solid organ recovery can lead to life-threatening complications in the recipients. The prevalence of such a contamination needs to be established. From January 2004 to December 2008, we prospectively investigated the potential fungal contamination of all the PSs collected in our institution using a standardised procedure consisting in centrifugation of 10 mL PS and incubation of the pellet seeded on fungal-specific medium for 15 days at 30 degrees C. During the study period, 728 transplantations (397 kidneys, 262 livers and 69 hearts) were performed for which 659 PSs (90.5%) were available. The yeast contamination rate was 0% (0/62), 3.1% (11/356) and 4.1% (10/241) for heart, kidney and liver transplants, respectively. We identified 10 Candida albicans, five C. glabrata, two C. krusei, one C. tropicalis, one C. valida, one Pichia etchelsii and one Rhodorula sp. Routine bacterial analysis identified only five of these 21 fungal contaminations. Twenty recipients were alive after at least one year of follow-up and one died from meningeal carcinomatosis at seven months. Three patients were found to have the same species of Candida from their surgical drains but did not develop any infection or abnormalities upon ultrasound investigation. Fourteen patients received antifungal drugs. Yeast contamination occurred in 3.4% of all kidney and liver PSs tested. Its clinical consequences and therapeutic management remain to be defined. Our study also suggests that optimisation/standardisation of microbiological procedures is warranted, including analysis of large PS volume, seeding of fungal-specific medium and prolonged incubation.