Investigation of Ni/4H-SiC diodes as radiation detectors with low doped n-type 4H-SiC epilayers

The development of SiC minimum ionising particle (MIP) detectors imposes severe constrains in the electronic quality and the thickness of the material due to the relatively high value of the energy required to produce an electron–hole pair in this material by MIP against the value for Si. In this work, particle detectors were made using semiconductor epitaxial undoped n-type 4H-SiC as the detection medium. The thickness of the epilayer is on the order of 40 μm and the detectors are realised by the formation of a nickel silicide on the silicon surface of the epitaxial layer (Schottky contact) and of the ohmic contact on the back side of 4H-SiC substrate. The low doping concentration (6×10¹³ cm⁻³) of the epilayer allows the detector to be totally depleted at relatively low reverse voltages (100 V). We present experimental data on the charge collection properties by using 5.486 MeV -particles impinging on the Schottky contact. A 100% charge collection efficiency (CCE) is demonstrated for reverse voltages higher than the one needed to have a depletion region equal to the -particle extrapolated range in SiC. The diffusion contribution of the minority change carriers to CCE is pointed out. By comparing measured CCE values to the outcomes of drift–diffusion simulation, values are inferred for the hole lifetime within the neutral region of the charge carrier generation layer.     

THE ROLE OF INTERFACIAL PHENOMENA IN A LIQUID-LIQUID REACTION SYSTEM: EXTRACTION OF PROPANOIC ACID BY TRIOCTYLAMINE

The kinetics of extraction of propanoic acid from water to isobulanol by reaction with trioctylamine have been investigated. Mass transfer was modelled by extending the approach used in absorption with chemical reaction, as it is usually done for liquid-liquid reactions. The presence of the amine, however, gave rise to phenomena that cause this method to fail, producing inconsistent results. In order to explain these data, the presence of relevant interfacial phenomena must be supposed.     

Adipose Stromal/Stem Cell-Derived Extracellular Vesicles: Potential Next-Generation Anti-Obesity Agents

Over the last decade, several compounds have been identified for the treatment of obesity. However, due to the complexity of the disease, many pharmacological interventions have raised concerns about their efficacy and safety. Therefore, it is important to discover new factors involved in the induction/progression of obesity. Adipose stromal/stem cells (ASCs), which are mostly isolated from subcutaneous adipose tissue, are the primary cells contributing to the expansion of fat mass. Like other cells, ASCs release nanoparticles known as extracellular vesicles (EVs), which are being actively studied for their potential applications in a variety of diseases. Here, we focused on the importance of the contribution of ASC-derived EVs in the regulation of metabolic processes. In addition, we outlined the advantages/disadvantages of the use of EVs as potential next-generation anti-obesity agents.     

The Genetic Basis of Primary Myelofibrosis and Its Clinical Relevance

Among classical BCR-ABL-negative myeloproliferative neoplasms (MPN), primary myelofibrosis (PMF) is the most aggressive subtype from a clinical standpoint, posing a great challenge to clinicians. Whilst the biological consequences of the three MPN driver gene mutations (JAK2, CALR, and MPL) have been well described, recent data has shed light on the complex and dynamic structure of PMF, that involves competing disease subclones, sequentially acquired genomic events, mostly in genes that are recurrently mutated in several myeloid neoplasms and in clonal hematopoiesis, and biological interactions between clonal hematopoietic stem cells and abnormal bone marrow niches. These observations may contribute to explain the wide heterogeneity in patients’ clinical presentation and prognosis, and support the recent effort to include molecular information in prognostic scoring systems used for therapeutic decision-making, leading to promising clinical translation. In this review, we aim to address the topic of PMF molecular genetics, focusing on four questions: (1) what is the role of mutations on disease pathogenesis? (2) what is their impact on patients’ clinical phenotype? (3) how do we integrate gene mutations in the risk stratification process? (4) how do we take advantage of molecular genetics when it comes to treatment decisions?     

Next-Generation Sequencing Workflow for NSCLC Critical Samples Using a Targeted Sequencing Approach by Ion Torrent PGM? Platform

Next-generation sequencing (NGS) is a cost-effective technology capable of screening several genes simultaneously; however, its application in a clinical context requires an established workflow to acquire reliable sequencing results. Here, we report an optimized NGS workflow analyzing 22 lung cancer-related genes to sequence critical samples such as DNA from formalin-fixed paraffin-embedded (FFPE) blocks and circulating free DNA (cfDNA). Snap frozen and matched FFPE gDNA from 12 non-small cell lung cancer (NSCLC) patients, whose gDNA fragmentation status was previously evaluated using a multiplex PCR-based quality control, were successfully sequenced with Ion Torrent PGM™. The robust bioinformatic pipeline allowed us to correctly call both Single Nucleotide Variants (SNVs) and indels with a detection limit of 5%, achieving 100% specificity and 96% sensitivity. This workflow was also validated in 13 FFPE NSCLC biopsies. Furthermore, a specific protocol for low input gDNA capable of producing good sequencing data with high coverage, high uniformity, and a low error rate was also optimized. In conclusion, we demonstrate the feasibility of obtaining gDNA from FFPE samples suitable for NGS by performing appropriate quality controls. The optimized workflow, capable of screening low input gDNA, highlights NGS as a potential tool in the detection, disease monitoring, and treatment of NSCLC.     

Fluidized state gelation of ceramic microspheres: Feasibility study of a continuous process and analysis of the chemical dehydration phenomena

A continuous gelation process for producing aluminum and zirconium hydroxide microparticles was conceived and tested in a lab‐scale apparatus. Fluidized state was devised as an appropriate hydrodynamic configuration to maintain the reacting sol microdrops suspended: stable non‐coalescing spherical gel particles in a size range quite below 100 μm were produced via gelation. The microspheres produced by a subsequent calcination step showed a diameter ranging between 2 μm and 20 μm. This powder, without further size classification, was an optimal product to manufacture test specimens by sintering. Measurements on the mechanical properties, such as toughness, flexural strength and hardness, classified the test bars as a very promising ceramic material. In order to enlighten the chemical drying phenomenon and devise the main governing mechanisms acting in the gelation reaction, an extremely simplified experimental system was set. A single drop of sol was deposited into a given amount of the dehydrating liquid medium and observed by an optical microscope; image analysis permitted us to identify the gel formation, the size reduction kinetics, as well as secondary phenomena.     

Use of polyacrylamide as a tissue-equivalent material in themicrowave range

The use of polyacrylamide gel to simulate biological tissues at microwave frequencies is presented. Formulation and preparation procedures are discussed. Measurements of complex permittivity in the range from 0.75 to 5.5 GHz, together with its temperature sensitivity, are reported. Thermal and optical properties have also been measured: the polyacrylamide is transparent and may be used as a phantom material in designing and testing applicators for microwave hyperthermia and for dosimetry studies     

Biosorption of silver from aqueous solutions using wine industry wastes

The potential of wine industry wastes (grape peel, seed, and stem) as alternative biosorbents to remove Ag from aqueous media was investigated in this work. Wine industry wastes were washed, lyophilized and pulverized to obtain the biosorbents. The powdered biosorbents were characterized in detail and several batch experiments were performed to found the most suitable conditions for Ag biosorption. Kinetic, equilibrium, and thermodynamic studies were also performed. The interactions Ag-biosorbent were elucidated by analyses before and after the biosorption. For all wastes, the maximum removal percentages were found using a biosorbent dosage of 3.0?g?L^?1 at pH of 7.0. The kinetic data were well represented by the pseudo-first-order model. The equilibrium was satisfactorily represented by the Sips model. The maximum biosorption capacities, found at 298?K, were: 41.7, 61.4, and 46.4?mg?g^?1 for grape peel, seed, and stem, respectively. Thermodynamically, the biosorption was a spontaneous, favorable, exothermic, and enthalpy-controlled process. The magnitude of ΔH⁰ indicated a physical sorption. These results showed that the wine industry wastes can be considered alternative efficient, low-cost, and eco-friendly biosorbents to remove Ag from aqueous media.