Acidity of SiO2-Supported Metal Oxides in the Presence of H2O Using the Adsorption Equilibrium Infrared Spectroscopy Method: 1. Adsorption and Coadsorption of NH3 and H2O on SiO2.

The present study is dedicated to the characterization (identification, heats of adsorption, and coverages) of the adsorbed species formed by the adsorption and coadsorption of NH3 and H2O on two SiO2 solids. Adsorption equilibrium infrared spectroscopy allowed us (a) to show that NH3 and H2O are mostly adsorbed on free SiOH groups via H bonds and (b) to determine their individual heats of adsorption: 53 and 49 kJ/mol, whatever be their coverages (Langmuir adsorption model), for NH3ads and H2Oads, respectively. These values consistent with the microcalorimetry literature data explain that their coverages are decreased upon NH3-H2O coadsorption, considering a competitive Langmuir model. However, the temperature-programmed adsorption equilibrium procedure achieved from MS data indicated that a minor amount of other NH3 species (not detected using Fourier-transform infrared) is more strongly adsorbed and that hydrolysis of SiOSi siloxane by H2O could occur in parallel. NH3-H2O coadsorption leads to the formation of NH4+ species, which involves H2O adsorbed species. Both NH3 and H2O are not adsorbed above 450 K, which means that the SiO2 contribution to the characterization of the acidity of metal oxide catalysts supported on SiO2 using NH3 as the probe molecule in the presence of H2O is negligible above this temperature.

Acidity of SiO2-Supported Metal Oxides in the Presence of H2O Using the AEIR Method: 2. Adsorption and Coadsorption of NH3 and H2O on TiO2/SiO2 Catalysts.

Two different TiO2/SiO2 compounds containing TiO2 nanodomains dispersed over SiO2 were investigated applying the AEIR method at the adsorption equilibrium of NH3 and H2O from 300 to 723 K, particularly for the measurement of the individual heats of adsorption of the different species on Lewis acidic sites (LAS) and Brønsted acidic sites (BAS) as evaluation of the strength of the sites. It revealed two types of NH3 adsorption sites: the first ones could correspond either to NH3 species H-bonded to free OH groups or to coordinated weak LAS (named L1). The second ones (L2) were attributed to strongest LAS similar to those present at the surface of TiO2 nanocrystallites. They also correspond to the stronger adsorption sites of H2O. Two types of Brønsted acid sites (BAS) were additionally evidenced by the AEIR method and proposed to be specifically located on the Si-O-Ti bridging bonds at the TiO2/SiO2 interface. The heats of adsorption of the different adsorbed species provided by the AEIR method were consistent with literature data on average values of the heats of adsorption of NH3 and H2O from microcalorimetry measurements. The surface acidity of the two compounds in the presence of H2O was determined using NH3-H2O coadsorption. At T ≥ 473 K, the NH3 species on the L2 sites were not significantly displaced from the surface whatever the partial pressure of H2O studied in agreement with the Temkin competitive model using the individual heats of adsorption of the NH3 and H2O species. This model also revealed the presence of a small amount of H2O species adsorbed on L2 sites allowing H2O dissociation or/and hydrolysis of SiOTi or TiOTi bridges, leading to the formation of a much higher amount of BAS. Therefore, this original work combining the AEIR method and the Temkin competitive model provided new insights for understanding water effects on acidic oxide catalysts.

A case of mixed-pattern calcifications in multinodular goiter associated with a benign diagnosis.

BACKGROUND: Calcified nodules are often found in a goiter when performing an ultrasound of the neck. An analysis of different calcification patterns could contribute to discriminating between nodules with a lower malignancy risk and those with a higher malignancy risk. In certain cases, the results of a simple cytological analysis of a nodule are not specific enough to be completely trusted. CASE PRESENTATION: We present the case of a goiter with a mixed calcification pattern, including a type of calcification that is strongly associated with a malignant diagnosis, for which a completely benign diagnosis was determined. CONCLUSION: We believe that further studies examining a combination of ultrasound (US) and computed tomography (CT) scan presentations of thyroid nodules need to be performed.

Behavior of Escherichia coli O157:H7 during the manufacture and ripening of Fontina Protected Designation of Origin cheese.

This study was conducted to describe the cheese-making procedure of Fontina Protected Designation of Origin (PDO) cheese and to evaluate the behavior of Escherichia coli O157:H7 during cheese manufacture and ripening. The study was divided into 2 phases: the production of Fontina PDO cheese was monitored at 3 different dairies in the Aosta Valley and an E. coli O157 challenge was conducted at a fourth dairy. The dairies employ different commercial starter cultures for cheese making. The growth of lactic acid bacilli (LAB) and the decrease in pH were slower in the first hours and the LAB concentrations were overall higher in dairy A than in the other 2 dairies. The pH remained substantially unchanged during ripening (range 5.2 to 5.4) in all dairies. Water activity remained constant at around 0.98 until d 21, when it decreased to around 0.97 until d 80 in dairies A and B and 0.95 in dairy E. Whole raw cow milk was used for making Fontina cheese according to the standard procedure. For the experimental production, the milk was inoculated with E. coli O157:H7 at a concentration of approximately 5 log10 cfu/mL and commercial starter cultures were used according to the Fontina PDO regulation. An increase of 2.0 log10 cfu/g in E. coli O157:H7 was observed during the first 9.5 h of cheese making, followed by a decrease at 46 h when pH decreased to 5.4 in all trials. Fresh cheeses were salted and held at 10°C for ripening for 80 d. Water activity was decreased to 0.952 at the end of the ripening stage. The LAB concentrations declined gradually; this trend was more marked for the lactobacilli than either the thermophilic or the mesophilic lactococci. The increase in LAB count and the decrease in pH in the first hours did not seem to affect E. coli O157 growth. Ripening was found to inhibit pathogen survival, however, as seen in the reduction of 3 log10 from the maximum concentration measured during the earlier stages of production.

Intravescical prostatic protrusion is a predictor of alpha blockers response: results from an observational study.

BACKGROUND: To investigate the efficacy of tamsulosin in patients with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) with intravesical prostatic protrusion (IPP). Ultrasound measurement of the IPP has been previously described as an effective instrument for the evaluation of benign prostatic obstruction (BPO) and could help in clarifying the role of alpha-blockers in patients with (BPE). METHODS: Patients with BPE and LUTS were enrolled in this observational study. Intravesical prostatic protrusion was graded as grade 1 (< 5 ml), 2 (5 < IPP < 10 ml) and 3 (> 10 ml). Patients were treated with tamsulosin for twelve weeks. Evaluation was performed before and at the end of treatment by means of International Prostate Symptom Score (IPSS) and uroflowmetry. Patients were considered responders if a reduction of IPSS > 3 points was reported. RESULTS: One hundred forty-two patients were enrolled. Twelve patients were excluded because of incomplete data. Fifty patients showed an IPP grade 1 (group A), 52 a grade 2 (group B) and 28 a grade 3 (group C). Treatment success was obtained in 82%, 38,5% and 7,1% of patients respectively; these differences (group A vs B-C and group B vs C) were highly significant. The odd ratio to obtain a treatment success was of 59 and 8.1 in group A and group B respectively, in comparison to group C. After a multivariate regression, the relationship between IPP grade and treatment success remained significant. Improvement of uroflowmetry parameters has been reported in all the groups especially in patients with a low grade IPP (p value = 0,016 group A vs group B; p value = 0,005 group A vs group C). Prostate volume seems not to influence this relationship. CONCLUSIONS: Intravesical prostatic protrusion has found to be significantly and inversely correlated with treatment success in patients with LUTS and BPE under alpha-blockers therapy. Alpha blockers odd ratio of success is 59 times higher in patients with a low grade IPP in comparison to patients with a high grade.

A coupled human-Earth model perspective on long-term trends in the global marine fishery.

The global wild marine fish harvest increased fourfold between 1950 and a peak value near the end of the 20th century, reflecting interactions between anthropogenic and ecological forces. Here, we examine these interactions in a bio-energetically constrained, spatially and temporally resolved model of global fisheries. We conduct historical hindcasts with the model, which suggest that technological progress can explain most of the 20th century increase of fish harvest. In contrast, projections extending this rate of technological progress into the future under open access suggest a long-term decrease in harvest due to over-fishing. Climate change is predicted to gradually decrease the global fish production capacity, though our model suggests that this is of secondary importance to social and economic factors. Our study represents a novel way to integrate human-ecological interactions within a single model framework for long-term simulations.

Confined placental mosaicism for 22q11.2 deletion as the etiology for discordant positive NIPT results.

22q11.2 deletion, the most common microdeletion syndrome within the general population, is estimated to have a prevalence of 1 in 3000 to 6000. Non-invasive prenatal testing has recently expanded to include screening for several microdeletions including 22q11.2. Given the expansion of prenatal screening options to include microdeletions, it is important to understand the limits of this technology and the variety of reasons that a discordant positive result can occur. Here, we describe a case of a pregnant woman who received a positive non-invasive prenatal maternal plasma screen for 22q11.2 deletion. Maternal and postnatal neonatal peripheral blood cytogenetic, PCR, and fluorescence in situ hybridization studies were normal, but the placenta was mosaic for 22q11.2 deletion in two of three biopsy sites. This case illustrates both the complexities of pre- and post-test counseling for microdeletion screening and the potential for a discordant positive microdeletion result because of confined placental mosaicism. © 2017 John Wiley & Sons, Ltd.

Paediatric HUS Cases Related to the Consumption of Raw Milk Sold by Vending Machines in Italy: Quantitative Risk Assessment Based on Escherichia coli O157 Official Controls over 7 years.

A quantitative risk assessment (RA) was developed to estimate haemolytic-uremic syndrome (HUS) cases in paediatric population associated with the consumption of raw milk sold in vending machines in Italy. The historical national evolution of raw milk consumption phenomenon since 2008, when consumer interest started to grow, and after 7 years of marketing adjustment, is outlined. Exposure assessment was based on the official Shiga toxin-producing Escherichia coli O157:H7 (STEC) microbiological records of raw milk samples from vending machines monitored by the regional Veterinary Authorities from 2008 to 2014, microbial growth during storage, consumption frequency of raw milk, serving size, consumption preference and age of consumers. The differential risk considered milk handled under regulation conditions (4°C throughout all phases) and the worst time-temperature field handling conditions detected. In case of boiling milk before consumption, we assumed that the risk of HUS is fixed at zero. The model estimates clearly show that the public health significance of HUS cases due to raw milk STEC contamination depends on the current variability surrounding the risk profile of the food and the consumer behaviour has more impact than milk storage scenario. The estimated HUS cases predicted by our model are roughly in line with the effective STEC O157-associated HUS cases notified in Italy only when the proportion of consumers not boiling milk before consumption is assumed to be 1%. Raw milk consumption remains a source of E. coli O157:H7 for humans, but its overall relevance is likely to have subsided and significant caution should be exerted for temporal, geographical and consumers behaviour analysis. Health education programmes and regulatory actions are required to educate people, primarily children, on other STEC sources.

Assessing the fetal effects of maternal obesity via transcriptomic analysis of cord blood: a prospective case-control study.

OBJECTIVE: To analyse fetal gene expression at term using umbilical cord blood, in order to provide insights into the effects of maternal obesity on human development. DESIGN: Prospective case-control study. SETTING: Academic tertiary care centre. POPULATION: Eight obese (body mass index ≥30 kg/m(2)) and eight lean (body mass index <25 kg/m(2)) pregnant women undergoing prelabour caesarean delivery at term. METHODS: Women were matched for gestational age and fetal sex. Cord blood RNA was extracted and hybridised to gene expression arrays. Differentially regulated genes were identified using paired t-tests and the Benjamini-Hochberg correction. Functional analyses were performed using Ingenuity Pathway Analysis, BioGPS and Gene Set Enrichment Analysis with a fetal-specific annotation. Z-scores ≥2.0 or P-values <0.01 were considered significant. MAIN OUTCOME MEASURE: Functions of differentially regulated genes in fetuses of obese women. RESULTS: A total of 701 differentially regulated genes were identified, producing an expression profile implicating neurodegeneration, decreased survival of sensory neurons, and decreased neurogenesis in the fetuses of obese women. Upstream regulators related to inflammatory signalling were significantly activated; those related to insulin receptor signalling, lipid homeostasis, regulation of axonal guidance, and cellular response to oxidative stress were significantly inhibited. Of 26 tissue-specific genes that were differentially regulated in fetuses of obese women, six mapped to the fetal brain. CONCLUSION: Maternal obesity affects fetal gene expression at term, implicating dysregulated brain development, inflammatory and immune signalling, glucose and lipid homeostasis, and oxidative stress. This may have implications for postnatal neurodevelopment and metabolism.

Neck schwannoma diagnosed by core needle biopsy: a case report.

Here we present a case of a 58 year old man referred to our hospital to undergo neck and thyroid ultrasonography (US) following palpable neck mass. US revealed a solid hypoechoic nodule in right thyroid lobe, and a solid lesion on the right laterocervical neck region with ultrasound suspicious features of neoplastic lymph node. In order to achieve a diagnosis of the neck mass and to get a proper evaluation of the thyroid nodule, we decided to perform a fine-needle aspiration (FNA) of both lesions. At cytopathologic examination the thyroid nodule appeared as benign, while cytologic sampling of the neck lesion was inadequate for a proper evaluation. Thus, we performed core needle biopsy (CNB) of the neck lesion like recently proposed for thyroid lesions; also, to definitively exclude malignancy of thyroid nodule, this also underwent CNB. Histologic report of CNB confirmed benign thyroid nodule, while the neck lesion revealed a proliferation of neuronal type consistent with schwannoma. The patient has been addressed to clinical and ultrasonographic follow-up. CNB appears as a safe and minimally-invasive approach to diagnose indeterminate neck masses and avoid unnecessary diagnostic surgery.

Methicillin resistance in Staphylococcus aureus strains isolated from food and wild animal carcasses in Italy.

Following the detection of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in food-producing animals, both livestock and wildlife, and derived products, are considered potential sources of MRSA in humans. There is a paucity of data on MRSA in foods in Italy, and the data regarding wild animals are particularly scarce. A total of 2162 food samples collected during official monitoring activities in 2008 were analyzed for the detection of S. aureus. Also, samples from 1365 wild animals collected by the National Reference Center for Wild Animal Diseases in 2003-2009 were subjected to anatomopathological examination. S. aureus isolates were processed for phenotypic and molecular methicillin resistance determinations. S. aureus was found in 2.0% of wild animal carcasses and in 3.2% of wild boar lymph nodes: none showed methicillin resistance. The prevalence of S. aureus in food was 17.1%. Two MRSA strains, both from bulk tank milk (prevalence 0.77%) were isolated: the strains were resistant to tetracycline, had spa-type t899, and were negative for the Panton-Valentine leukocidin gene. The low prevalence of MRSA suggests that the risk of transmission to humans via food is limited. However, attention should be paid to the cattle food chain, which may be a potential route of transmission of LA-MRSA.

Bilateral Ureteral Obstruction in Children after Appendectomy.

Acute renal failure due to bilateral ureteral obstruction is a rare complication after appendectomy in children. We report a case of bilateral ureteric obstruction in a 14-year-old boy nine days after surgery for an acute appendicitis. After saline-filling of the urinary bladder, transabdominal ultrasound demonstrated bilateral hydronephrosis of moderate degree. No abscess was found with CT but presence of millimetric stones on both distal ureters was shown, with bilateral calyceal dilatation. Cystoscopy revealed inflammatory changes in the bladder base. Following introduction of bilateral ureteric stents, there was rapid normalisation of urinary output and serum creatinine.

Applicability of Macroscopic Wear and Friction Laws on the Atomic Length Scale.

Using molecular dynamics, we simulate the abrasion process of an atomically rough Fe surface with multiple hard abrasive particles. By quantifying the nanoscopic wear depth in a time-resolved fashion, we show that Barwell's macroscopic wear law can be applied at the atomic scale. We find that in this multiasperity contact system, the Bowden-Tabor term, which describes the friction force as a function of the real nanoscopic contact area, can predict the kinetic friction even when wear is involved. From this the Derjaguin-Amontons-Coulomb friction law can be recovered, since we observe a linear dependence of the contact area on the applied load in accordance with Greenwood-Williamson contact mechanics.

Reproducibility study for the detection of Staphylococcal enterotoxins in dairy products between official Italian national laboratories.

Staphylococcal food poisoning is a common foodborne disease caused by the ingestion of staphylococcal enterotoxins (SEs) produced mainly by enterotoxigenic strains of Staphylococcus aureus. To date, 21 SEs and/or enterotoxin-like types have been identified, several of which represent a potential hazard for consumers. To protect consumer health and to reduce the amount of SE-contaminated food entering the market, European Union legislation regulating food safety requires testing for SEs. The Italian National Reference Laboratory organized a ring trial to test technical and analytical proficiency in the national network of official food laboratories. Twenty-four laboratories took part, and each received and analyzed 24 blind dairy samples. Reproducibility of the results from the laboratories was assessed by the Cohen k index, and accuracy (sensitivity and specificity) was evaluated according to the International Organization for Standardization definition (ISO 16140:2003). Trial results revealed partially satisfactory agreement: 254 of 276 possible paired participants (92%) reached a k value >0.60, which is conventionally recognized as satisfactory. Accuracy was deemed satisfactory; 100% sensitivity and 100% specificity were achieved by 22 and 18 of the 24 laboratories, respectively.

Validation according to ISO 16140:2003 of a commercial real-time PCR-based method for detecting Campylobacter jejuni, C. coli, and C. lari in foods.

Campylobacteriosis was the most frequently reported zoonosis in the European Union (EU) in 2010, with Campylobacter jejuni, Campylobacter coli, and Campylobacter lari as the most frequently reported species in foodborne outbreaks (FBOs). Relatively sensitive to environmental factors, these species may be present in low numbers. In line with EU policy for food control and FBO detection and in view of the need to reduce response time, we validated an alternative molecular method according to ISO 16140:2003 which establishes the general principle and technical protocol for the validation of alternative methods in the microbiological analysis of food. We used a qualitative real-time PCR commercial kit for the detection of C. jejuni, C. coli, and C. lari in two food categories "fruit and vegetable-based products" and "dairy products". The validation protocol comprises two phases: the first is a method comparison study of the alternative method against the reference method, and the second is an interlaboratory study of each of the two methods. In the first step, ISO 16140:2003 validation examines the following parameters: limit of detection (LOD); relative accuracy, relative specificity and sensitivity; relative detection level (RDL); and inclusivity and exclusivity. Except for LOD, inclusivity and exclusivity, the other steps were performed against the reference method (ISO 10272:2006). The LOD of the real-time PCR method was set at 4CFU/25g or mL for both food categories. Relative accuracy (98.33%), specificity (96.77%), and sensitivity (100%) were recorded for the food category "fruit and vegetable-based products" and 93.3%, 88.24%, 100%, respectively, for "dairy products". The RDL according to Fisher's exact test was p=1 for both food categories, for each level, and each food/strain combination. The interlaboratory study results showed correct identification of all 24 blind samples with both methods by all the participating laboratories. The results show that this commercial kit is suitable for the rapid detection of C. jejuni, C. coli, and C. lari on fruit, vegetables and dairy products and may aid in official controls. In conclusion, the use of alternative methods is recommended for the rapid identification of positive samples and the identification of the possible bacterial source in a FBO within 48 h.

Review: cell-free fetal DNA in the maternal circulation as an indication of placental health and disease.

In human pregnancy, the constant turnover of villous trophoblast results in extrusion of apoptotic material into the maternal circulation. This material includes cell-free (cf) DNA, which is commonly referred to as "fetal", but is actually derived from the placenta. As the release of cf DNA is closely tied to placental morphogenesis, conditions associated with abnormal placentation, such as preeclampsia, are associated with high DNA levels in the blood of pregnant women. Over the past five years, the development and commercial availability of techniques of massively parallel DNA sequencing have facilitated noninvasive prenatal testing (NIPT) for fetal trisomies 13, 18, and 21. Clinical experience accrued over the past two years has highlighted the importance of the fetal fraction (ff) in cf DNA analysis. The ff is the amount of cell-free fetal DNA in a given sample divided by the total amount of cell-free DNA. At any gestational age, ff has a bell-shaped distribution that peaks between 10 and 20% at 10-21 weeks. ff is affected by maternal body mass index, gestational age, fetal aneuploidy, and whether the gestation is a singleton or multiple. In approximately 0.1% of clinical cases, the NIPT result and a subsequent diagnostic karyotype are discordant; confined placental mosaicism has been increasingly reported as an underlying biologic explanation. Cell-free fetal DNA is a new biomarker that can provide information about the placenta and potentially be used to predict clinical problems. Knowledge gaps still exist with regard to what affects production, metabolism, and clearance of feto-placental DNA.

Enterotoxin gene profiles of Staphylococcus aureus isolated from milk and dairy products in Italy.

UNLABELLED: Staphylococcal foodborne intoxication, occurring after consumption of staphylococcal enterotoxins (SEs) in food, is considered one of the most common forms of bacterial foodborne outbreaks worldwide. Milk and dairy products account for 5% of all the incriminated foods in staphylococcal outbreaks, referring to Europe. The distribution of genes encoding for enterotoxins in Staphylococcus aureus strains is highly variable, with some carried on stable regions of the chromosome and others carried on mobile genetic elements. The aim of this study was to analyse the distribution of genes encoding for SEs in Staph. aureus strains isolated from milk and dairy products. In the period from January 2010 to June 2011, a total of 1245 dairy samples (848 of raw milk and 397 of dairy products) were collected and analysed for detection of genes encoding for 11 SEs and SEls (SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI, SER SElJ and SElP) according to the procedures of the Italian National Reference Laboratory for coagulase-positive Staphylococci including Staph. aureus. Staphylococcus aureus strains were isolated in 481 (39%) samples. Of the 481 isolates of Staph. aureus tested, 255 (53%) were positive for one or more SE genes, and thirty-five different enterotoxin gene profiles were distinguished among the isolates. ser gene, found in 134 (28%) of the isolates, was the most frequent, followed by sed (25%) and selj genes (25%). The identification of new SEs increased the isolation frequency of enterotoxigenic staphylococci, thus suggesting that the pathogenic potential of Staph. aureus may be of greater importance than previously thought. Further studies are needed to quantify the expression of these new enterotoxins, and to assess their contribution to foodborne disease burden. SIGNIFICANCE AND IMPACT OF THE STUDY: The analyses targeted 11 staphylococcal enterotoxins genes and 35 different enterotoxin gene profiles were distinguished among the isolates. A total of 255 Staph. aureus isolates were positive for one or more SE genes while ser gene was the most prevalent. In 93% of the isolates bearing genes located on the enterotoxin gene cluster (n = 89), both seg and sei genes were present.

Staphylococcal poisoning foodborne outbreak: epidemiological investigation and strain genotyping.

In June 2011, an outbreak of Staphylococcus aureus enterotoxin food poisoning gastroenteritis occurred in Turin, Italy, following a catered dinner party at a private home. Within a few hours, 26 of the 47 guests experienced gastrointestinal illness, and 9 were hospitalized. A retrospective cohort study using a standardized questionnaire was carried out, and the risk ratios for each food item were calculated. The analysis indicated consumption of seafood salad as the most probable cause of the outbreak (risk ratio = 11.72; 95 % confidence interval, 1.75 to 78.54). Biological samples were collected from four of the hospitalized guests (stool and vomit), nasal mucosa swabs from three food handlers employed with the caterer, and available food residuals. All stool and vomit samples tested positive for enterotoxigenic S. aureus. As residues of the seafood salad were no longer available for sampling, suspected contamination could not be verified. However, no other food was found contaminated by S. aureus or its enterotoxins. All isolates from the biological samples were characterized at the genomic level by means of two multiplex PCR protocols to determine the presence of genes encoding staphylococcal enterotoxins, pulsed-field gel electrophoresis and staphylococcal protein A gene (spa) typing to describe their genetic profiles. All the isolates presented genes encoding SEA and SEI; the pulsed-field gel electrophoresis genetic profiles revealed the same pulsotype in the microorganism isolated from the hospitalized guests as in one of the isolates from a food handler's nasal mucosa, and the spa typing analysis reported two closely related spa types (t701 and t267), implicating the food handler as the most likely outbreak source.