Risk Assessment of RYR Food Supplements: Perception vs. Reality

Thirty-seven red yeast rice (RYR) food supplements were screened for their mycotoxin and natural statin content. Products included pure RYR capsules and multi-ingredient formulations with standardized amounts of monacolin K (MK), marketed both online and retail in the European Union. In terms of mycotoxins, citrinin (CIT) was found in all the monitored products. As CIT content ranged from 100 to 25100 μg/kg, only four products were compliant with maximum EU levels in force until April 2020, while a single product was compliant with the limit of 100 μg/kg introduced after that date. Four contaminated products were labeled as “citrinin free”. In terms of natural statins, nine products had a lower content vs. label statements (from −30 to −83%), while for 24 a larger MK amount (from 10 to 266%) was noticed. Three products had a negligible MK content and only 19 offered a daily dosage exceeding 10 mg as dictated by the health claim granted by EFSA in the EU. No sample had label values compliant with pharmaceutical Good Manufacturing Practices requirements (95–105% content of active constituent). Variable, but small amounts of simvastatin (0.1–7.5 μg per daily dose) were found in 30 samples. These results suggest that limited efficacy and reported safety issues may stem from an under-regulated and undercontrolled market, weakening both effectiveness and risk assessment evaluations

Structural relaxation in PLLA: Contribution of different scale motions

The enthalpy relaxation in amorphous and semi-crystalline poly(L-lactic acid) (PLLA) has been investigated at low and high undercooling to identify the different scale motions that contribute to physical ageing, and the temperature ranges in which they are active. The temperature limit below which exclusively small-scale localized motions produce structural relaxation in PLLA has been identified. In addition, motions different from pure cooperative large-scale motions and pure small-scale local rearrangements, localized in the mobile amorphous fraction, are found to mainly contribute to structural relaxation at intermediate undercoolings. These motions are suggested to be related with the Johari-Goldstein process

Flow boiling heat transfer capabilities of R134a low GWP substitutes inside a 4\ua0mm id horizontal smooth tube: R600a and R152a

R134a was recognized as probably one of the most important refrigerants of the two past decades. Among the proposed alternative fluids, there are certainly isobutane (R600a) and R152a.\ua0This article presents about 200 new heat transfer coefficient and pressure drop data obtained during flow boiling of R152a and R600a inside a smooth copper tube having an internal diameter of 4\ua0mm.\ua0Three saturation temperatures were considered for each refrigerant, from 5\ua0\ub0C to 20\ua0\ub0C. Furthermore, for each temperature studied, the heat flux was varied between 15 and 30\ua0kW\ua0m 122 and the refrigerant mass flux from 100 to 400\ua0kg\ua0m 122\ua0s 121. After presenting the new data, a critical comparison was proposed between the performance of these refrigerants and R134a. Finally, some classic correlations available in the literature have been implemented. The deviations between the calculated and experimental values were reported and commented

Performance evaluation of Attribute-Based Encryption on constrained IoT devices

The Internet of Things (IoT) is enabling a new generation of innovative services based on the seamless integration of smart objects into information systems. This raises new security and privacy challenges that require novel cryptographic methods. Attribute-Based Encryption (ABE) is a type of public-key encryption that enforces a fine-grained access control on encrypted data based on flexible access policies. The feasibility of ABE adoption in fully-fledged computing systems, i.e., smartphones or embedded systems, has been demonstrated in recent works. In this paper, we consider IoT devices characterized by strong limitations in terms of computing, storage, and power. Specifically, we assess the performance of ABE in typical IoT constrained devices. We evaluate the performance of three representative ABE schemes configured considering the worst-case scenario on two popular IoT platforms, namely ESP32 and RE-Mote. Our results show that, if we assume to employ up to 10 attributes in ciphertexts and to leverage hardware cryptographic acceleration, then ABE can indeed be adopted on devices with very limited memory and computing power, while obtaining a satisfactory battery lifetime. In our experiments, as also performed in other works in the literature, we consider only the worst-case configuration, which, however, might not be completely representative of the real working conditions of sensors employing ABE. For this reason, we complete our evaluation by proposing a novel benchmark method that we used to complement the experiments by evaluating the average performance. We show that by always considering the worst case, the current literature significantly overestimates the processing time and the energy consumption

The structure of gravel-bed flow with intermediate submergence: a laboratory study

The paper reports an experimental study of the flow structure over an immobile gravel bed in open channel at intermediate submergence, with particular focus on the near-bed region. The experiments consisted of velocity measurements using three-component (stereoscopic) Particle Image Velocimetry (PIV) in near-bed horizontal plane and two-component PIV in three vertical planes that covered three distinctly different hydraulic scenarios where the ratio of flow depth to roughness height (i.e., relative submergence) changes from 7.5 to 10.8. Detailed velocity measurements were supplemented with fine-scale bed elevation data obtained with a laser scanner. The data revealed longitudinal low-momentum and high-momentum "strips'' in the time-averaged velocity field, likely induced by secondary currents. This depth-scale pattern was superimposed with particle-scale patches of flow heterogeneity induced by gravel particle protrusions. A similar picture emerged when considering second-order velocity moments. The interaction between the flow field and gravel-bed protrusions is assessed using cross correlations of velocity components and bed elevations in a horizontal plane just above gravel particle crests. The cross correlations suggest that upward and downward fluid motions are mainly associated with upstream-facing and lee sides of particles, respectively. Results also show that the relative submergence affects the turbulence intensity profiles for vertical velocity over the whole flow depth, while only a weak effect, limited to the near-bed region, is noticed for streamwise velocity component. The approximation of mean velocity profiles with a logarithmic formula reveals that log-profile parameters depend on relative submergence, highlighting inapplicability of a conventional "universal'' logarithmic law for gravel-bed flows with intermediate submergence

Evaluation of Feasibility and Impact of Attacks against the 6top Protocol in 6TiSCH Networks

The 6TiSCH architecture has been gaining attraction as a promising solution to ensure reliability and security for communication in applications for the Industrial Internet of Things (IIoT). While many different aspects of the architecture have been investigated in literature, an in-depth analysis of the security features included in its design is still missing. In this paper, we assess the security vulnerabilities of the 6top protocol, a core component of the 6TiSCH architecture for enabling network nodes to negotiate communication resources. Our analysis highlights two possible attacks against the 6top protocol that can impair network performance and reliability in a significant manner. To prove the feasibility of the attacks in practice, we implemented both of them on the Contiki-NG Operating System and tested their effectiveness on a simple deployment with three Zolertia RE-Mote sensor nodes. Also, we carried out a set of simulations using Cooja in order to assess their impact on larger networks. Our results show that both attacks reduce reliability in the overall network and increase energy consumption of the network nodes

Development of a flow process for an easy and fast access to 2-pyrone derivatives

2-Pyrones are compounds widely present in nature and they represent interesting building blocks both in medicinal and synthetic chemistry. Due to their peculiar pharmacological activity and structure, they have attracted much attention during the last decades and several protocols for their synthesis have been developed. In this work we propose the synthesis of bio-sourced 2-pyrones, exploiting continuous-flow conditions for an easy, sustainable and fast access to these important molecules

A Bayesian approach for the assessment of shallow and deep aquifers susceptibility to point sources contamination in the Province of Milan, Italy

In densely populated areas, urban and industrial activities are responsible for groundwater quality deterioration due to point sources contamination (Kuroda and Fukushi, 2008). In the Province of Milan (Northern Italy), the available water-quality data indicate the occurrence of high PCE+TCE and chromium concentrations in the unconfined shallow as well as in the confined deep aquifers. To cope with this problem, statistical methods can represent reliable tools to provide key information for groundwater management and protection

Effect of the addition of natural rice bran oil on the thermal, mechanical, morphological and viscoelastic properties of poly(Lactic Acid)

For the first time in this study, the utilization of rice bran oil (RBO) as possible totally eco-friendly plasticizer for poly(lactic acid) (PLA) has been investigated. For comparison, the behavior of soybean oil (SO) has also been analyzed. Both oils are not completely miscible with PLA. However, certain compatibility exists between PLA and (i) RBO and (ii) SO, because demixing is not complete. Although not totally miscible, RBO and SO are able to reduce the viscosity of the PLA+RBO and PLA+SO mixtures, which attests that a small amount of RBO or SO can be successfully added to PLA to improve its processability. Additionally, the mechanical properties of the PLA+RBO and PLA+SO mixtures exhibit trends typical of plasticizer-polymer systems. More interestingly, RBO was found to accelerate the growth of PLA α'-crystals at a low crystallization temperature. This feature is appealing, because the α'-phase presents lower elastic modulus and higher permeability to water vapor in comparison to the α-phase, which grows at high temperatures. Thus, this study demonstrates that the addition of RBO to PLA in small percentages is a useful solution for a faster preparation of PLA materials containing mainly the α'-phase

A Bayesian approach for the assessment of shallow and deep aquifers susceptibility to point sources contamination in the Province of Milan, Italy

In densely populated areas, urban and industrial activities are responsible for groundwater quality deterioration due to point sources contamination (Kuroda and Fukushi, 2008). In the Province of Milan (Northern Italy), the available water-quality data indicate the occurrence of high PCE+TCE and chromium concentrations in the unconfined shallow as well as in the confined deep aquifers. To cope with this problem, statistical methods can represent reliable tools to provide key information for groundwater management and protection