Microfluidic Templated Multicompartment Microgels for 3D Encapsulation and Pairing of Single Cells

Controlled encapsulation and pairing of single cells within a confined 3D matrix can enable the replication of the highly ordered cellular structure of human tissues. Microgels with independently controlled compartments that can encapsulate cells within separately confined hydrogel matrices would provide precise control over the route of pairing single cells. Here, a one‐step microfluidic method is presented to generate monodisperse multicompartment microgels that can be used as a 3D matrix to pair single cells in a highly biocompatible manner. A method is presented to induce microgels formation on chip, followed by direct extraction of the microgels from oil phase, thereby avoiding prolonged exposure of the microgels to the oil. It is further demonstrated that by entrapping stem cells with niche cells within separate but adjacent compartments of the microgels, it can create complex stem cell niche microenvironments in a controlled manner, which can serve as a useful tool for the study of cell–cell interactions. This microfluidic technique represents a significant step toward high‐throughput single cells encapsulation and pairing for the study of intercellular communications at single cell level, which is of significant importance for cell biology, stem cell therapy, and tissue engineering.     

A method based on Graph Theory and Three Way Decisions to evaluate critical regions in epidemic diffusion:

Applied Intelligence - The paper reports the results of an analysis of COVID-19 diffusion in Italy. The analysis was carried out with a new method based on the combined use of a 3 Way Decisions...     

Solving job shop scheduling with setup times through constraint-based iterative sampling: an experimental analysis

This paper presents a heuristic algorithm for solving a job-shop scheduling problem with sequence dependent setup times and min/max separation constraints among the activities (SDST-JSSP/max). The algorithm relies on a core constraint-based search procedure, which generates consistent orderings of activities that require the same resource by incrementally imposing precedence constraints on a temporally feasible solution. Key to the effectiveness of the search procedure is a conflict sampling method biased toward selection of most critical conflicts and coupled with a non-deterministic choice heuristic to guide the base conflict resolution process. This constraint-based search is then embedded within a larger iterative-sampling search framework to broaden search space coverage and promote solution optimization. The efficacy of the overall heuristic algorithm is demonstrated empirically both on a set of previously studied job-shop scheduling benchmark problems with sequence dependent setup times and by introducing a new benchmark with setups and generalized precedence constraints.     

Chloroplastic glycolipids fuel aldehyde biosynthesis in the marine diatom Thalassiosira rotula

Enzymatic preparations and specialized analytical tools have shown that chloroplast-derived glycolipids are the main substrates for the biosynthetic pathway that produces antiproliferative polyunsaturated aldehydes in broken cells of the marine diatom Thalassiosira rotula. This process, which is associated with the formation of free fatty acids and lyso compounds from polar lipids but not triglycerides, is largely dependent on glycolipid hydrolytic activity, rather than phospholipase A(2) as previously suggested. Preliminary characterization of lipolytic enzymes has revealed protein bands of 40-45 kDa. Under native conditions these proteins seem to be associated with soluble aggregates that have an apparent molecular weight of approximately 200 kDa. The biochemical process, which is similar to that described in the algal-bloom forming diatom Skeletonema costatum, suggests a mechanism based on decompartmentalization and mixing of preexisting enzymes and substrates.     

An adaptive in-network aggregation operator for query processing in wireless sensor networks

A wireless sensor network (WSN) is composed of tens or hundreds of spatially distributed autonomous nodes, called sensors. Sensors are devices used to collect data from the environment related to the detection or measurement of physical phenomena. In fact, a WSN consists of groups of sensors where each group is responsible for providing information about one or more physical phenomena (e.g., group for collecting temperature data). Sensors are limited in power, computational capacity, and memory. Therefore, a query engine and query operators for processing queries in WSNs should be able to handle resource limitations such as memory and battery life. Adaptability has been explored as an alternative approach when dealing with these conditions. Adaptive query operators (algorithms) can adjust their behavior in response to specific events that take place during data processing. In this paper, we propose an adaptive in-network aggregation operator for query processing in sensor nodes of a WSN, called ADAGA (ADaptive AGgregation Algorithm for sensor networks). The ADAGA adapts its behavior according to memory and energy usage by dynamically adjusting data-collection and data-sending time intervals. ADAGA can correctly aggregate data in WSNs with packet replication. Moreover, ADAGA is able to predict non-performed detection values by analyzing collected values. Thus, ADAGA is able to produce results as close as possible to real results (obtained when no resource constraint is faced). The results obtained through experiments prove the efficiency of ADAGA.     

Cloning, characterization, expression and antifungal activity of an alkaline serine protease of Aureobasidium pullulans PL5 involved in the biological control of postharvest pathogens

An alkaline protease gene was amplified from genomic DNA and cDNA of the antagonistic yeast-like fungus Aureobasidium pullulans PL5, a biocontrol agent effective against Monilinia laxa on stone fruit and Botrytis cinerea and Penicillium expansum on pome fruits. An open reading frame of 1248 bp encoding a 415-amino acid (aa) protein with a calculated molecular weight (M_r) of 42.9 kDa and an isoelectric point (pI) of 4.5 was characterized. The cDNAALP5 gene had an 18-amino acid signal peptide, one N-gylcosylation, one histidine active site, and one serine active site. The ALP5 gene with a M_r of 1351 bp contained two introns. One intron was of 54 bp, while the other was of 50 bp. Protein BLAST and phylogenetic tree analysis of the deduced amino sequences from the cDNAALP5 gene showed that the encoded protein had 100% homology to a protease enzyme (ALP2) of a sea strain of A. pullulans, suggesting that the protein ALP5 was an alkaline serine protease. Expression of ALP5 in Escherichia coli BL21 (DE3), followed by identification with Western-blotting, purification with Ni-NTA and analysis of enzymatic activity, yielded an homogeneous recombinant ALP5 which hydrolysed the substrate casein and inhibited the mycelial growth of the pathogens. At its optimal pH of 10.0 and reaction temperature of 50 °C, the recombinant protease exhibited the highest activity towards the substrate casein, though the highest stability was at lower temperatures and pH between 7.0 and 9.0. This study provided the direct evidence that extracellular proteases secreted by the antagonist A. pullulans PL5 played a role in the biocontrol activities against some postharvest pathogens of apple and peach.     

The role of tryptophan in protein fibrillogenesis: relevance of Trp7 and Trp14 to the amyloidogenic properties of myoglobin

In order to understand the role of tryptophan in the mechanisms of fibrils formation, the ability of a series of analogs of the residue 7-18 span of myoglobin to form amyloid-like fibrils was investigated. Alternatively one or both tryptophans were substituted with alanine and leucine, to determine the contribution of hydrophobicity and aromaticity. The scale of aggregation propensity of the peptides determined indicates that tryptophan is crucial for the amyloidogenic process. Since the rare tryptophan residue is generally engaged in structural roles in proteins, or when exposed serves as binding sites, we surmise that its exposure in the amyloidogenic fragments allows for intermolecular clustering with residues from other molecules leading to the formation of amyloid aggregates.     

Heterogeneous Catalysis in Biodiesel Production: The Influence of Leaching

The catalytic performances of several solid catalysts in the transesterification of vegetable oils with methanol were studied in small steel vials. The eventual presence of an homogeneous contribution to the catalysis—due to the leaching of the active phase—was also investigated. The behaviour of one of the more promising catalyst (TiO₂ supported on SiO₂) was further deepened in batch and continuous reactors by using the catalysts in pellets, to evaluate the possibility of developing an industrial process based on this catalyst. The catalyst life-time run, in a continuous tubular reactor, was determinant for this evaluation.     

Corrosion behavior of Eurofer 97 and ODS-Eurofer alloys compared to traditional stainless steels

In the present work, the corrosion resistance of ferritic-martensitic EUROFER 97 and ODS-EUROFER steels was tested in solutions containing NaCl or H₂SO₄ and KSCN, both at 25 °C. The results were compared to those of AISI 430 ferritic and AISI 410 martensitic conventional stainless steels. The as-received samples were tested by electrochemical techniques, specifically, electrochemical impedance spectroscopy, potentiodynamic polarization curves, and double-loop electrochemical potentiokinetic reactivation tests. The surfaces were observed by scanning electron microscopy after exposure to corrosive media. The results showed that EUROFER 97 and ODS-EUROFER alloys present similar corrosion resistance but lower than ferritic AISI 430 and martensitic 410 stainless steels.