Vibrational Study on the Structure, Bioactivity, and Silver Adsorption of Silk Fibroin Fibers Grafted with Methacrylonitrile

Natural fibers have received increasing attention as starting materials for innovative applications in many research fields, from biomedicine to engineering. Bombyx mori silk fibroin has become a material of choice in the development of many biomedical devices. Grafting represents a good strategy to improve the material properties according to the desired function. In the present study, Bombyx mori silk fibroin fibers were grafted with methacrylonitrile (MAN) with different weight gains. The potential interest in biomedical applications of MAN functionalization relies on the presence of the nitrile group, which is an acceptor of H bonds and can bind metals. IR and Raman spectroscopy were used to characterize the grafted samples and the possible structural changes induced by grafting. Afterward, the same techniques were used to study the bioactivity (i.e., the calcium phosphate nucleation ability) of MAN-grafted silk fibroins after ageing in simulated body fluid (SBF) for possible application in bone tissue engineering, and their interaction with Ag+ ions, for the development of biomaterials with enhanced anti-microbial properties. MAN was found to efficiently polymerize on silk fibroin through polar amino acids (i.e., serine and tryptophan), inducing an enrichment in silk fibroin-ordered domains. IR spectroscopy allowed us to detect the nucleation of a thin calcium phosphate layer and the uptake of Ag+ ions through the nitrile group, which may foster the application of these grafted materials in biomedical applications

Spectroscopic and morphological data assessing the apatite forming ability of calcium hydroxide-releasing materials for pulp capping

A pulp capping material must perform as a barrier and protect the dental pulpal complex by inducing the formation of a new dentin bridge or dentin-like tissue. Being a favorable condition for the healing process, the apatite forming ability of TheraCal (light-curable Portland-dimethacrylate cement) and Dycal (calcium hydroxide-based) pulp capping materials was studied in two simulated body fluids, i.e. Dulbecco's Phosphate Buffered Saline (DPBS) and Hank's Balanced Salt Solution (HBSS). The cements were analyzed before and after soaking in these media for different times (1\u201328 days) by ESEM-EDX, micro-Raman and IR spectroscopy. This data article refers to \u201cAn in vitro study on dentin demineralization and remineralization: collagen rearrangements and influence on the enucleated phase\u201d (Di Foggia et al., 2019)

Post-harvest non-conventional and traditional methods to control cadophora luteo-olivacea: Skin pitting agent of actinidia chinensis var. deliciosa (A. chev.)

Cadophora luteo-olivacea represents a critical problem for kiwifruit in the post-harvest phase, mainly for its little note epidemiology. The study presented some results about the possibility of preserving kiwifruit from skin pitting symptoms using alternative methods to fungicides. By in vitro assays, antagonist mechanisms of action against pathogen isolates were tested. Trichoderma harzianum (Th1) showed the highest inhibitory activity against C. luteo-olivacea isolates by volatile, non-volatile, and by dual culture assay, displaying an inhibition respectively by 90%, 70.6%, and 78.8%, and with respect to Aureobasidium pullulans (L1 and L8) by 23.3% and 25.8%, 50% and 34.7%, and 22.5% and 23.6%, respectively. Further, the sensitivity on CFU and mycelial growth of C. luteo-olivacea isolates to fludioxonil, and CaCl2 was tested, displaying interesting EC50 values (0.36 and 0.92 g L-1, 22.5 g L-1, respectively). The effect of Brassica nigra defatted meal was tested as biofumigation assays and through FT-IR (Fourier-Transform Infrared) spectroscopy. The above-mentioned treatments were applied in vivo to evaluate their efficacy on kiwifruits. Our data demonstrated that alternative solutions could be considered to control postharvest pathogens such as C. luteo-olivacea

The Influence of the Matrix on the Apatite-Forming Ability of Calcium Containing Polydimethylsiloxane-Based Cements for Endodontics

This study aimed to characterize the chemical properties and bioactivity of an endodontic sealer (GuttaFlow Bioseal) based on polydimethylsiloxane (PDMS) and containing a calcium bioglass as a doping agent. Commercial PDMS-based cement free from calcium bioglass (GuttaFlow 2 and RoekoSeal) were characterized for comparison as well as GuttaFlow 2 doped with dicalcium phosphate dihydrate, hydroxyapatite, or a tricalcium silicate-based cement. IR and Raman analyses were performed on fresh materials as well as after aging tests in Hank's Balanced Salt Solution (28 d, 37 degrees C). Under these conditions, the strengthening of the 970 cm(-1) Raman band and the appearance of the IR components at 1455-1414, 1015, 868, and 600-559 cm(-1) revealed the deposition of B-type carbonated apatite. The Raman I-970/I-638 and IR A(1010)/A(1258) ratios (markers of apatite-forming ability) showed that bioactivity decreased along with the series: GuttaFlow Bioseal > GuttaFlow 2 > RoekoSeal. The PDMS matrix played a relevant role in bioactivity; in GuttaFlow 2, the crosslinking degree was favorable for Ca2+ adsorption/complexation and the formation of a thin calcium phosphate layer. In the less crosslinked RoekoSeal, such processes did not occur. The doped cements showed bioactivity higher than GuttaFlow 2, suggesting that the particles of the mineralizing agents are spontaneously exposed on the cement surface, although the hydrophobicity of the PDMS matrix slowed down apatite deposition. Relevant properties in the endodontic practice (i.e., setting time, radiopacity, apatite-forming ability) were related to material composition and the crosslinking degree

Few-shot re-identification of the speaker by social robots

Nowadays advanced machine learning, computer vision, audio analysis and natural language understanding systems can be widely used for improving the perceptive and reasoning capabilities of the social robots. In particular, artificial intelligence algorithms for speaker re-identification make the robot aware of its interlocutor and able to personalize the conversation according to the information gathered in real-time and in the past interactions with the speaker. Anyway, this kind of application requires to train neural networks having available only a few samples for each speaker. Within this context, in this paper we propose a social robot equipped with a microphone sensor and a smart deep learning algorithm for few-shot speaker re-identification, able to run in real time over an embedded platform mounted on board of the robot. The proposed system has been experimentally evaluated over the VoxCeleb1 dataset, demonstrating a remarkable re-identification accuracy by varying the number of samples per speaker, the number of known speakers and the duration of the samples, and over the SpReW dataset, showing its robustness in real noisy environments. Finally, a quantitative evaluation of the processing time over the embedded platform proves that the processing pipeline is almost immediate, resulting in a pleasant user experience

Chemical and physical characterization of thermal aggregation of model proteins modulated by zinc (II) and copper (II) ions.

BACKGROUND: Metal ions are implicated in protein aggregation processes of several neurodegenerative pathologies, where the protein deposition occurs, and in the biotechnology field like the food technology where many processes in food manufacturing are based on thermal treatments. OBJECTIVE: The influence of Cu2+ or Zn2+ ions on the thermal aggregation process of Bovine beta-lactoglobulin (BLG) and Bovine Serum Albumin (BSA), two protein models, was studied with the aim of delineating the role of these ions in the protein aggregation kinetics and to clarify the related molecular mechanisms. METHODS: The protein structure changes were monitored by Raman spectroscopy, whereas the aggregate growth was followed by Dynamic Light Scattering measurements. RESULTS: Both metal ions are able to favour the BLG aggregation, whereas only Zn2+ ions have a promoter effect on the thermal aggregation of BSA. The reason of this different behaviour is that the BLG aggregation evolution is manly affected by the redistribution of charges, whereas that of BSA by the metal coordination binding which depends on metal. CONCLUSIONS: Raman spectroscopy, combined with dynamic light scattering experiments, was very useful in identifying the role played by Cu2+ and Zn2+ on the aggregation pathways of BLG and BSA. The results provide evidence for the role of histidine residues both in the redistribution of charges and in the two modes of metal binding that take place in BLG- and BSA-containing systems, respectively

Assessing the potential of the terrestrial cyanobacterium Anabaena minutissima for controlling Botrytis cinerea on tomato fruits

Cyanobacteria are oxygenic phototrophs that have an essential role in soil N2 fixation, fertility, and water retention. Cyanobacteria are also natural sources of bioactive metabolites beneficial to improve plant vigor and potentially active against fungal plant pathogens. Therefore, we studied the antifungal activity of water extract (WE) and phycobiliproteins (PBPs) from Anabaena minutissima strain BEA 0300B against the fungal plant pathogen Botrytis cinerea on tomato fruits and in vitro. The water extract and PBPs were characterized by using FT-IR and FT-Raman spectroscopies. Both water extract (5 mg/mL) and PBPs (ranged from 0.3 to 4.8 mg/mL) reduced disease incidence and disease severity on tomato fruits and mycelium growth and colony forming units in vitro. For mycelium growth, a linear PBP dose-response was found. Tomato fruits were also characterized by FT-IR and FT-Raman spectroscopies in order to evaluate structural modifications induced by pathogen and PBP treatment. PBPs preserved cutin and pectin structures by pathogen challenge. In conclusion, A. minutissima can be considered a potential tool for future large-scale experiments for plant disease control

Vibrational Raman and IR data on brown hair subjected to bleaching

Brown human hair was bleached three times (45 min × 3) and four times (45 min × 3 + 15 min) with commercial formulations containing persulfate salts and hydrogen peroxide. The hair samples were characterized by Raman and IR spectroscopy in the Attenuated Total Reflectance (ATR) mode to gain more insights into the possible secondary structure and Cα-Cβ-S-S-Cβ-Cα conformational changes induced by bleaching. The latter were evaluated through band-fitting procedures; the relative content of the disulfide bridges and oxidized sulfur species (cysteic acid, Bunte salt, cystine oxides) was assessed. The observed conformational changes could be significant in developing restoring agents to be used after hair decoloration. The use of two different spectroscopic techniques allowed to discriminate the information coming from the cortical region of hair (Raman) and the cuticle (ATR/IR). This article refers to “Structural investigation on damaged hair keratin treated with α,β-unsaturated Michael acceptors used as repairing agents” (Di Foggia et al., Int. J. Biol. Macromol. 167 (2021) 620–632 https://doi.org/10.1016/j.ijbiomac.2020.11.194)

On the Uniform Random Generation of Non Deterministic Automata Up to Isomorphism

In this paper we address the problem of the uniform random generation of non deterministic automata (NFA) up to isomorphism. First, we show how to use a Monte-Carlo approach to uniformly sample a NFA. Secondly, we show how to use the Metropolis-Hastings Algorithm to uniformly generate NFAs up to isomorphism. Using labeling techniques, we show that in practice it is possible to move into the modified Markov Chain efficiently, allowing the random generation of NFAs up to isomorphism with dozens of states. This general approach is also applied to several interesting subclasses of NFAs (up to isomorphism), such as NFAs having a unique initial states and a bounded output degree. Finally, we prove that for these interesting subclasses of NFAs, moving into the Metropolis Markov chain can be done in polynomial time. Promising experimental results constitute a practical contribution.Comment: Frank Drewes. CIAA 2015, Aug 2015, Umea, Sweden. Springer, 9223, pp.12, 2015, Implementation and Application of Automata - 20th International Conferenc

Cognitive Decision-making Systems for Scraps Control in Aerospace Turbine Blade Casting☆

Abstract The competitiveness of a casting system in modern lost wax production of superalloy turbine blades strongly depends on the reduction of scraps, which commonly affect superalloy cast parts. In order to achieve a focused goal of competitiveness, some key and vital parameters (Key Process Variables) have to be continuously taken under control to make very accurate predictions of Target Variables, which represent, as mapped KPVs domain, the ultimate performance of the entire production link. Such an approach is based on the development of robust control monitoring of the ceramic shell manufacture, which is specifically conceived to foster a possible reduction of scraps in the production if superalloy components. The concerned control will take into consideration data coming from both sensors and measured values in laboratory. The sensor data, which is originated from both new adopted inline and offline equipments at Europea Microfusioni Aerospaziali S.p.A. (EMA) and data measured in the EMA laboratories, will be merged into a sensor pattern vector which represents the basis to develop the EMA demonstrator within the Intelligent Fault Correction and self Optimizing manufacturing systems EU project funded in FP7. The sensor pattern vector will be used to feed an automatic system for the prediction of the process vital parameters. An automated system, based on artificial intelligence paradigms, in particular neural networks, will be fed with the data coming from the sensor pattern vector in order to produce an optimal multi-object output