Based on the principle of stability of geopolymer gel as refractory binder, a geopolymeric paste in the K
2
O–Al
2
O
3
–SiO
2
system was developed and used to produce refractory concretes by adding ...various amount of α-quartz sand (grain size in the range 0.1 μm to 1 mm) and fine powder alumina (grain size in the range 0.1–100 μm). The consolidated samples were characterized before and after sintering using optical dilatometer, DSC, XRD and SEM. The total shrinkage in the range of 25–900 °C was less than 3%, reduced with respect to the most diffused potassium or sodium based geopolymer systems, which generally records a >5% shrinkage. The maximum shrinkage of the basic geopolymer composition was recorded at 1000 °C with a 17% shrinkage which is reduced to 12% by alumina addition. The temperature of maximum densification was shifted from 1000 °C to 1150 or 1200 °C by adding 75 wt% α-quartz sand or fine powder alumina respectively. The sequences of sintering of geopolymer concretes could be resumed as dehydration, dehydroxylation, densification and finally plastic deformation due to the importance of liquid phase. The geopolymer formulations developed in this study appeared as promising candidates for high-temperature applications: refractory, fire resistant or insulating materials.
The guarantee of the origin and quality of raw material is essential for the protection and valorization of Campana buffalo mozzarella cheese. The risk of utilization of semifinished products and ...stored milk in substitution for fresh milk is increasing, due to the continuous desire to reduce production costs. A proteomics approach and electrophoresis survey of retail mozzarella cheeses indicated different rates of proteolysis in the production of dairy industries. The use of fresh milk and correct cheesemaking protocol yielded only γ-caseins, which are derived from β-casein by plasmin, and para-κ-casein, which is derived from κ-casein by chymosin. The detection of abnormal hydrolysis resulting in β- and αS1-casein fragments, identified by mass spectrometry, indicates the use of stored milk or stored and pressed curd, or the reuse of unsold mozzarella cheese, to produce mozzarella. The formation of γ-caseins and other fragments during a long storage of raw materials at room or refrigeration temperature was ascribed to plasmin (endogenous milk enzyme), whereas formation of αS1-casein fragments, mainly αS1-I6P- and αS1-I7P-casein during the storage of curd was ascribed to the action of chymosin (exogenous enzyme) from rennet. Sodium dodecyl sulfate-PAGE and alkaline urea-PAGE permitted us to evaluate the freshness of the raw materials used in the manufacturing of buffalo mozzarella cheese and to reveal possible inappropriate preservation.
The effect of intense electromagnetic fields, generated inside a multimode microwave applicators, on the crystallization of calcium carbonate polymorphs starting from calcium bicarbonate solutions ...has been investigated. The identification and quantitative analysis of the calcium carbonate polymorphs has been made by X-ray diffraction using Rietveld-Reference Intensity Ratio (RIR) method. Scanning Electron Microscopy analysis has also been performed to study the morphology of calcium carbonate samples. Crystallization tests have been conducted at atmospheric pressure while adjusting microwave power to maintain solution temperature between 80 °C and 90 °C. For the sake of comparison, calcium carbonate powders have also been prepared using conventional heating either in a oven or on a hot plate with a magnetic stirrer. The experiments conducted using microwave radiation gave in a high percentage yield of aragonite (99%) which has been favoured by increasing microwave exposure times. Low microwave exposure times, on the other hand, favours vaterite formation which crystallized in an unusual flower-like morphology.
Effect of microwave irradiation on crystallization of calcium carbonate from homogeneous solution was studied. The increase of microwave exposure time favours the formation of needle-like aragonite particles which can reach the 99% of the overall calcium carbonate crystals. Such a result is difficult to afford by means of the conventional heating methods.
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Summary
Background Alopecia areata (AA) is a multifactorial disease characterized by hair loss especially from the scalp. As for other autoimmune conditions, the major histocompatibility complex ...(HLA) region is associated with AA susceptibility.
Objective To provide evidence for the association of specific HLA‐DQB1 and HLA‐DRB1 alleles with AA in an Italian population, using a case–control approach.
Methods We performed a case–control study to investigate whether HLA‐DQB1 and ‐DRB1 alleles predispose to AA in the Italian population. HLA class II typing was performed in 85 patients with AA and 210 healthy controls from the same ethnic group.
Results An increased frequency of DQB1*03, coding for DQ7 heterodimers, and a decreased rate of the DQB1*06 allele were observed in patients when compared with controls; the greatest and significant difference was in the group of cases with a more severe phenotype AA > 50% patients (more than 50% hair loss) vs. controls, P = 4·5 × 10−3, Pc = 0·031, odds ratio (OR) 2·01, 95% confidence interval (CI) 1·22–3·31 and P = 2·5 × 10−3, Pc = 0·017, OR 0·22, 95% CI 0·07–0·72, respectively. DQB1*03, serologically related to DQ8 or coding for DQ9 molecules, was not associated with AA susceptibility. Out of all patients, 65·9% carried DQ7 heterodimers compared with 49·5% of the controls (P = 7·3 × 10−3, OR 1·97, 95% CI 1·17–3·32) and DQ7 prevalence rose to 76·3% in patients with AA > 50% (P = 1·7 × 10−3, OR 3·28, 95% CI 1·48–7·27). No significant difference was found in the distribution of DRB1 variants or phenotypes among cases and controls.
Conclusion Our data show a correlation between the HLA‐DQB1 locus and the occurrence of AA in Italy supporting DQB1*03(DQ7) as a predisposing allele for the disease and the relevance of the HLA genetic test in the clinical management of AA.
Vaccine-associated measles in a healthy 40-year-old woman Churchill, Lucas; Rizzuti, Francesco A; Fonseca, Kevin ...
CMAJ. Canadian Medical Association journal,
2018-Sep-04, 2018-09-04, 20180904, Letnik:
190, Številka:
35
Journal Article
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A 40-year-old woman, originally from Armenia, presented to the emergency department with a three-day history of fever, malaise, myalgia and nonproductive cough, followed by a rash that began on her ...face and spread downwards to her trunk and arms. She had delivered her first child nine weeks earlier with no complications. Ten days before onset of symptoms, she had received both mumps-measles-rubella and tetanus-diphtheria vaccinations. The patient lacked childhood immunization records and reported that she had not received all of her childhood vaccinations in Armenia owing to an allergic reaction, which remained unrecognized on her immigration to Canada. An acute respiratory viral infection, along with the possibility of measles, was considered based on the fever and rash presentation. A nasopharyngeal swab and urine sample were sent for respiratory viruses and measles virus testing. On admission, the patient was placed in an airborne isolation room, along with additional precautions.
Hodgkin lymphoma (HL) is cured in the majority of children and adolescents. However, there remains a group of patients with primary refractory or relapsed disease for whom cure is more difficult to ...achieve. Most of these patients receive high-dose chemotherapy followed by auto-SCT, with expected cure rates ranging from 40 to 60%. Conditioning regimens often consist of multiple non-cross-resistant agents, with well-described risks of morbidity and mortality. The use of single-agent high-dose melphalan (HDM) as conditioning, before autologous rescue, has been described in adult patients at our center, with comparable efficacy and less morbidity. We present a series of eight pediatric patients conditioned with single-agent HDM before autologous stem cell rescue for relapsed and primary refractory HL. All patients engrafted with a median of 12 days to neutrophil engraftment. Two patients subsequently relapsed. Seven patients are currently alive, and seven of eight patients have no evidence of disease (one in CR3). Toxicities included grade 4 hematologic in 8/8, grade 3 mucositis in 3/8, grade 3 infectious in 2/8 and grade 4 infectious in 1/8. Our analysis suggests that this regimen is feasible in pediatric patients with acceptable engraftment and toxicity.
•Analysis of brGDGT distributions in global peat dataset.•Correlation of brGDGT distributions with peat pH and mean annual air temperature.•Development of peat-specific temperature and pH proxies.
...Glycerol dialkyl glycerol tetraethers (GDGTs) are membrane-spanning lipids from Bacteria and Archaea that are ubiquitous in a range of natural archives and especially abundant in peat. Previous work demonstrated that the distribution of bacterial branched GDGTs (brGDGTs) in mineral soils is correlated to environmental factors such as mean annual air temperature (MAAT) and soil pH. However, the influence of these parameters on brGDGT distributions in peat is largely unknown. Here we investigate the distribution of brGDGTs in 470 samples from 96 peatlands around the world with a broad mean annual air temperature (−8 to 27°C) and pH (3–8) range and present the first peat-specific brGDGT-based temperature and pH calibrations. Our results demonstrate that the degree of cyclisation of brGDGTs in peat is positively correlated with pH, pH=2.49×CBTpeat+8.07 (n=51, R2=0.58, RMSE=0.8) and the degree of methylation of brGDGTs is positively correlated with MAAT, MAATpeat (°C)=52.18×MBT5me′−23.05 (n=96, R2=0.76, RMSE=4.7°C). These peat-specific calibrations are distinct from the available mineral soil calibrations. In light of the error in the temperature calibration (∼4.7°C), we urge caution in any application to reconstruct late Holocene climate variability, where the climatic signals are relatively small, and the duration of excursions could be brief. Instead, these proxies are well-suited to reconstruct large amplitude, longer-term shifts in climate such as deglacial transitions. Indeed, when applied to a peat deposit spanning the late glacial period (∼15.2kyr), we demonstrate that MAATpeat yields absolute temperatures and relative temperature changes that are consistent with those from other proxies. In addition, the application of MAATpeat to fossil peat (i.e. lignites) has the potential to reconstruct terrestrial climate during the Cenozoic. We conclude that there is clear potential to use brGDGTs in peats and lignites to reconstruct past terrestrial climate.
This work focuses on the assessment, in terms of effectiveness, feasibility and sustainability, of three different procedures for the synthesis of vanadium-based mixed-acid electrolytes to be used in ...vanadium redox-flow batteries (VRFBs). Procedures considered consisted in: a) the mere mixing of suitable vanadium precursors (Electrolyte A); b) the chemical reduction of V2O5 by oxalic acid (Electrolyte B); c) the electrochemical reduction of V2O5 using a home-made “H-shaped” electrolysis cell (Electrolyte C). VRFB properties such as energy efficiency, mean charge–discharge voltages, cycle duration as well as stability and conductivity of the electrolyte were analysed and compared with the state-of-the-art. Experimental tests carried out on a laboratory scale VRFB battery comprised: thermal stability test, cyclic voltammetry, electrochemical impedance spectroscopy measurements and charge–discharge tests. A Life Cycle Assessment of the three electrolytes is also presented for benchmarking purposes.
•Assessing sustainability of vanadium redox-flow battery electrolyte through advanced LCA tools (ISO 14040).•Sustainable experimental synthesis procedures of vanadium electrolytes.•Cradle-to-gate LCA comparison with local specific data.•Syntheses of mixed acid vanadium electrolytes for VRFB are compared in terms of effectiveness and sustainability.
Investigation on the use of volcanic ash as 100% raw materials for traditional vitrified ceramic products is reported. X-ray diffraction (XRD), thermogravimetric-thermal differential analyses ...(DTA-TGA) and chemical analysis were used to characterise raw samples. Fired specimens were used to evaluate their ceramic properties. Volcanic ash contains essentially classical traditional ceramic oxides, plagioclase, pyroxene and olivine as principal minerals. In the temperature range 1100-1150°C, they present dense structure, low open porosity, without isolated quartz grains. The fired materials properties were found to be in agreement with those of stoneware class BI referring to standard ISO 13006 (i.e.the water absorption values were <1·5%). The presence of a sufficiently extended glassy phase capable of embedding crystalline phases developed during sintering allows comparison of the microstructure of fired volcanic ash with that of traditional porcelain or stoneware.
Over the past ten years, several U.S. cities have switched from using free chlorine to chloramines to disinfect drinking water. Coincident with this shift have been reports by some water districts of ...lead (Pb) levels in drinking water that exceed the action limit of 15ppb set by the EPA. In this paper, a study was conducted on a water district that utilizes monochloramines to disinfect drinking water. The purpose of this research was to determine the Pb content of drinking water treated in this district. Water samples were collected both from homes with and from homes without Pb plumbing. The water samples were analyzed for Pb content using graphite furnace atomic absorption spectrophotometry. Samples obtained from homes without Pb plumbing had a Pb concentration range of 10.7 ppb − 20.3 ppb (average = 15.9 ppb), whereas samples obtained from homes with Pb plumbing had a Pb concentration range of 20.4 ppb − 73.9 ppb (average = 29.0 ppb). The average Pb concentrations for both types of homes were above the EPA action limit of 15ppb. The most plausible explanation for this is leaching of Pb from the water distribution system caused by the water treatment plants' use of monochloramines to disinfect water.
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