Application of the novel Droplet digital PCR technology for identification of meat species

The authenticity and traceability of meat products are issues of primary importance to ensure food safety. Unfortunately, food adulteration (e.g. the addition of inexpensive cuts to minced meat products) and mislabelling (e.g. the inclusion of meat from species other than those declared) happens frequently worldwide. The aim of this study was to apply a droplet digital PCR assay for the detection and quantification (copies μL⁻¹) of the beef, pork, horse, sheep, chicken and turkey in meat products. The analysis conducted on commercial meat showed the presence of traces of DNA from other animal species than those declared. We show that the method is highly sensitive, specific and accurate (accuracy = 100%). This method could be adopted by competent food safety authorities to verify compliance with the labelling of meat products and to ensure quality and safety throughout the meat supply chain, from primary production to consumption.     

Prefabricated building elements based on FGD gypsum and ashes from coal-fired electric generating plants

Mixtures of fly ash, bottom ash and Flue Gas Desulphurized (FGD) gypsum, all solid wastes from coalfired electric generating plants, can be combined with lime and 10% of water to produce a damp powder which can be moulded at a pressure of 20–40 MPa and then steam-cured in less than 1 day at 35–80°C. The resulting building materials-in the form of bricks, blocks or slabs-produced by this Pressure Forming (PF) process, are stronger and sounder than the corresponding materials produced by a slip casting (SC) process. The physical and mechanical properties of the materials manufactured through the PF process are based on the reaction of amorphous silica and alumina of the ash with lime or lime and gypsum respectively, so that calcium silicate hydrate and ettringite are produced. When the temperature of the steam curing is as low as 35°C, the hardened material is sound in the air, but it swells and is quickly destroyed by the action of water. This effect can be ascribed to the formation of ill-crystallized ettringite. On the other hand, with thermal treatment at higher temperatures (60–80°C), the material is stronger and sound even in the presence of water in service. The well-crystallized ettringite fibers, favoured by the higher temperature of the steam curing treatment, are considered to be responsible for the better mechanical performances and the lower change in length. In general, the physical and mechanical properties of the ash-gypsym-lime cementitious system are better than those of the traditional clay-based ceramic products manufactured at temperatures as high as 1000°C. Therefore, this process based on steam curing at 60–80°C appears to be very useful for both the re-utilization of solid wastes and the saving of energy in the production of building materials.     

Preoperative selection for curable renovascular hypertension

Clinical research has defined the criteria for identifying "curable" renovascular hypertension. The prediction is based on the measurement of plasma renin activity in peripheral veins, renal veins, and the aorta. Renin profiles can be examined with the method of Laragh and coworkers (the so-called incremental method), in which values for plasma renin activity are incorporated into formulas to compute indexed parameters. A score is attributed to each index and the prediction is based on the final score. Because the identification of curable renovascular hypertension is made according to numerical rules, the method is easily transformed into a computer-assisted process. The program is written in BASIC, and it is short enough to run on a personal computer.     

Reversible Fragmentation and Self‐Assembling of Nematic Liquid Crystal Droplets on Functionalized Pyroelectric Substrates

Investigation on the behavior of nematic liquid crystals on functionalized polar dielectric crystal substrates is accomplished. Very interesting effects can be observed in maneuvering liquid crystal droplets on the substrate surface, driven by electric fields generated by pyroelectric effect. Reversible drops fragmentation and self‐assembling in different configurations can be achieved. The dynamics of the observed phenomena is studied and the repeatability of the process is full assessed.     

Evaluation of the corrosion inhibition of salts of organic acids in alkaline solutions and chloride contaminated concrete

This paper summarizes the results of testing on salts of organic acids for evaluating their use as inhibitors of rebar corrosion in chloride‐contaminated concrete. Initially a screening based on electrochemical tests in alkalinized calcium hydroxide solutions was performed on a number of carboxylic acid salts with different number of carbon atoms in the chain and carboxylic groups, also covering substances with hydroxyl and amine group substituents. The screening was completed by testing on carbon steel rebars in concretes with chlorides and substances added at 1:1 molar ratio, focused on sodium lactate, sodium oxalate and sodium borate for comparison. The monitoring of free corrosion potential and linear polarization resistance of steel bars have confirmed significant inhibition only for lactate. Corrosion was only restricted to occluded zones where the access of substance was limited by disadvantageous geometry, producing shallow attacks. Results of further tests in saturated calcium hydroxide solution are reported in order to assess the inhibition ability of lactate as a function of its content, chloride content and pH.     

爆炸荷载下钢筋混凝土简支板的有限差分分析

考虑应变率效应、剪切和弯曲变形、横断面几何尺寸、荷载情况,编制有限差分分析程序,精确有效地分析爆炸荷载下钢筋混凝土简支板的动力响应。与构件截面应变速率相适应,采用截面分层分析模型,建立截面矩与和曲率的关系。根据所提公式,将相应的应变率效应与截面分层分析模型相结合,沿构件长度方向,对构件纵向应变速率的分布进行评估。采用明确的有限差分方法,可得到包括剪切变形和转动变量的Timoshenko梁方程的数值解。结合爆炸量和距离,根据钢筋混凝土板爆炸试验的结果,验证所提有限差分分析模型的精确性。与传统的单自由度分析和有限元分析相比,有限差分分析程序快速、精确,结合了单自由度分析的速度和有限元分析精确的优势,十分适合于设计公司应用。     

Electroosmotic transport in porous construction materials and dehumidification of masonry

Techniques based on electroosmosis have been proposed as restoration methods to reduce the moisture content in masonry subjected to capillary suction. Although several applications have been reported in the literature and beneficial effects of electroosmosis are often claimed, very little technical information is available. Quite rarely quantitative measurements of humidity changes in the masonry following the application of the current are reported. This paper reports the results of a research work aimed at studying the electroosmotic transport through porous construction materials, in order to investigate the factors that influence electroosmosis and define its actual technological applicability for the rehabilitation of damp masonry. The experimental tests showed that, for several concomitant circumstances, the chances that the technique based on electroosmosis might be effective in drying damp masonry are extremely low.     

The assessment of the damage probability of storage tanks in domino events triggered by fire

An approach aimed to the quantitative assessment of the risk caused by escalation scenarios triggered by fire was developed. Simplified models for the estimation of the vessel time to failure (ttf) with respect to the radiation intensity on the vessel shell were obtained using a multi-level approach to the analysis of vessel wall failure under different fire conditions. Each vessel “time to failure” calculated by this approach for the specific fire scenario of concern was compared to a reference time required for effective mitigation actions and related to the escalation probability. The failure probability of each vessel was correlated to the probability of scenarios involving multiple vessel failure as a consequence of the primary fire, thus allowing a comprehensive assessment of domino scenarios triggered by fire. The application of the methodology to the analysis of several case-studies allowed the estimation of the quantitative contribution of escalation events triggered by fire to the overall individual and societal risk indexes.     

Microbial succession during ripening of Naples-type salami, a southern Italian fermented sausage

Studies were carried out on the microbiological and physico-chemical changes which occurred during the ripening of five batches of Naples-type salami, manufactured without starter cultures. Salami were sampled internally and externally, and the following microbial groups were studied: lactic acid bacteria, Micrococcaceae and yeasts. The results obtained indicated that lactobacilli constituted the predominant flora, both on the surface and in the interior of the pieces throughout the ripening period. Micrococcaceae and yeasts were also found in considerable number in both locations. Characterisation of 191 lactic isolates indicated that the salami microflora was dominated by homofermentative lactobacilli; approximately 63% of them could be identified as Lactobacillus sake; 40% showing the traits of a racemase negative variant of this species, once referred to Lactobacillus bavaricus. Yeast population mainly comprised Debaryomyces strains. All the colonies grown on mannitol salt and Kranep agar were catalase-positive cocci; novobiocin-resistant staphylococci were the only Micrococcaceae found. The API Staph identification system did not prove to be reliable: 82% of the isolates remained unidentified. To achieve improved characterisation, cluster analysis was subsequently performed on this group, corroborating the existence of a fairly homogeneous group representing an intermediate variety between Staphylococcus xylosus and Staphylococcus saprophyticus that was isolated during the whole ripening process.