In vitro corrosion of some Co-Cr and Ni-Cr alloys used for removable partial dentures: influence of heat treatments

The influence of heat treatments on the corrosion resistance of some base-metal alloys currently used in dentistry as a base for porcelain substrate systems has been investigated. Four Co-Cr alloys (Wironit, Wironit extra hard, Wirobond and Wirolloy) and two Ni-Cr alloys (Wiron 88 and Wirolloy) were submitted to heat treatments for 30 min at 880, 980, 1080 °C for 30 min, and slowly cooled in air. The electrochemical characterization was performed by means of anodic polarization curves in Ringer's solution and artificial saliva at 37 °C. In both solutions it was found that ageing at 880 °C detrimentally affects the corrosion resistance of Co-Cr alloys; the passive zone is narrow and shows rather high current densities. On the contrary, the samples annealed at 1080 °C display a superior corrosion resistance. With Wiron 88 the effect is opposite, but the electrochemical behaviour of Wirolloy, is not affected by heat treatments; although it does have a more negative transpassive potential in artificial saliva and cannot be passivated in Ringer's solution. The SEM examination of the alloys evinces the microstructural modifications induced by heat treatments responsible for changes in the corrosion behaviour of the base-metal alloys.     

Lipomas of the large intestine

The incidence of lipomas of the colon is difficult to evaluate due to lack of symptoms. They are often discovered by chance during endoscopic or radiological examination and sometimes display only obstructive symptoms. A barium enema may be useful for the preoperative diagnosis of lipoma of the colon. The difficulty of obtaining a clear preoperative diagnosis influences the type of surgical treatment undertaken. Thus, a resection is often preferred to the simple removal of the lipoma by colotomy or endoscopy.     

Benign muscular dystrophy with hypergonadotrophic hypogonadism and congenital cataract

A syndrome characterized by benig muscular dystrophy, hypergonadotropic hypogonadism, congenital cataract and normal karyotype is reported. A similar condition was described by Bass?e. The patient's family tree revealed a number of isolated cases presenting some component of the syndrome, suggesting that this is connected with a recessive autosomic gene, probably with pleiotropic effect. The muscular disorder was absent in most of the other family members and its clinical signs were probably favoured by the low plasma level of testosterone with consequent reduced myotrophic action. The simultaneous presence of congenital cataract links the syndrome on the one hand to Steinert's myotonic dystrophy, although there were no clinical or electromyographic signs of myotonia, and on the other to other hereditary or familial neuroectodermal syndromes, compared to which it presents specific differential traits.     

Truncus arteriosus communis. Unusual case associated with transposition

A child with truncus arteriosus communis, characterized by the posterior origin of an individualized pulmonary trunk is presented. This relationship between the great arteries is unusual in truncus arteriosus communis and the spatial orientation resembles that seen in transposition of the great vessels. A brief discussion is proposed about a proper terminology in this type of complex anomaly.     

Colour-difference measurement: The sensitivity of various instruments compared

Because of the progress in electronic technology and the increasing importance of colour quality control in various branches of industry, over the last decades several colour-measuring instruments have been developed, each one with its own design features; the lack of standardization among them might be an obstacle to the spread of colour quality control as a means for product qualification. Colour-difference measurements taken with 11 different models of spectrophotometers [four with 45 (circumferential)/0 geometry and the others with diffuse geometry] were compared with the aim of analyzing their correlation and dispersion. In order to cover different colour-space regions, measurements were taken on test panels painted with four saturated basic hue (red, yellow, green, and blue) acrylic products gradually modified by adding white or black paint. Basic statistical analyses made on colour-difference values (ΔE*_ab, ΔL*, Δa*, and Δb*) resulted in a high correlation among the examined instruments, but a certain variability, particularly as far as certain hues are concerned.     

Composition and stability of phytochemicals in five varieties of black soybeans (Glycine max)

Phytochemical compositions of five varieties of black soybeans (Glycine max) and their stabilities at room temperature, 4 and −80 °C over 14 months were determined by HPLC systems with electrochemical (ECD) and UV detectors. Polyphenol profiling was carried out by a liquid chromatography–electrospray ionisation-mass spectrometry (LC–ESI-MS) with orbitrap as a mass analyser in both positive and negative ion modes, and polyphenols in aglycone forms were quantified by HPLC–ECD. Five different varieties of black soybeans (G. max) contained 249–405 μg/g dry wt of γ-tocopherol and 6.76–14.98 μg/g dry wt of lutein. Major polyphenols in black soybeans (G. max) were daidzein (193–288 μg/g dry wt) and genistein (145–223 μg/g dry wt), mainly present as glucosides and acetyl glucosides. No significant decrease was found in total phenols of black soybeans (G. max) stored at room temperature, 4 or −80 °C for 14 months. On the other hand, lutein and γ-tocopherol degraded significantly within a month of storage at room temperature (p < 0.01), whereas they remained stable up to 6 months at 4 °C and up to 14 months at −80 °C. The current study indicates that black soybeans (G. max) are rich source of γ-tocopherol and phenols (isoflavones, flavonols, flavan-3-ols, proanthocyanidins and anthocyanin) and that the levels vary depending upon varieties. In addition, storage at low temperature is recommended to reduce the loss of fat-soluble phytochemicals in black soybeans (G. max) over an extended period of time.     

Interactions between anthocyanins and organic food molecules in model systems

The interactions between different glucosidic anthocyanins (pelargonin, cyanin, delphinin, malvin and petunin) and some organic compounds (lactic, galacturonic, tannic, phenolic and sinapic acids; pyrogallol, furfural, pectin, cellulose, hydrolitic lignin) which are present in food‐stuffs were investigated at pH 3.0–4.3 and 25 °C. The interactions were monitored by means of u.v.‐VIS spectra and their different behaviours were highlighted by following changes in absorbance over a range of wavelengths (Δλ and ΔA). Significant effects on absorbance were detected and are discussed in terms of the phenomenon of co‐pigmentation.     

Online Portable Microcantilever Biosensors for Salmonella enterica Serotype Enteritidis Detection

The micro- and nano-technologies coupled with a deep knowledge of organic/inorganic interfaces guarantee an exceptional sensitivity and specificity of the sensor, while the lab-on-a-chip platform reduces assay times and limits sampling and/or sample preparation, providing compact and portable objects. Therefore, the development of innovative biosensors such as antibody-immobilized microcantilevers can overcome the evident limits of nowadays technologies, such as time consuming, expensiveness, difficult automation, low sensitivity, accuracy, and precision for quantitative methods. The present study proposes two device designs for the detection of food pathogens, exploiting an antibody-immobilized microcantilever biosensors, a novel class of mass detectors. For the first one, we integrated the mechanical sensors on a microfluidic platform (lab-on-a-chip) to perform online analysis, directly in liquid environment. We showed that our portable biosensors could easily detect the presence of pathogenic bacteria such as Salmonella enterica serotype enteritidis in concentration 10⁵ cfu/mL in just 40 min, without any enrichment and/or sample preparation. To increase the mass sensitivity of our analysis, we also fabricated microstructures optimized for vibrating in vacuum environment. Using a dip-and-dry technique, we showed that, in such configuration, the experimental limit of detection is as low as 10³ cfu/mL. Due to the extremely small volumes needed, our biosensors operating in vacuum have the potentiality of detecting the presence or absence of a single cell.     

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat

Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg^–1 for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, Pseudomonas spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the importance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment.