Ab Initio Modeling of Thermal Transport through van der Waals Materials

An advanced modeling approach is presented to shed light on the thermal transport properties of van der Waals materials (vdWMs) composed of single-layer transition metal dichalcogenides (TMDs) stacked on top of each other with a total or partial overlap only in the middle region. It relies on the calculation of dynamical matrices from first-principle and on their usage in a phonon quantum transport simulator. We observe that vibrations are transferred microscopically from one layer to the other along the overlap region which acts as a filter selecting out the states that can pass through it. Our work emphasizes the possibility of engineering heat flows at the nanoscale by carefully selecting the TMD monolayers that compose vdWMs.Comment: 14 pages, 11 figures, 6 table

Evaluation of the effect of berry extracts on carboxymethyllysine and lysine in ultra-high temperature treated milk

Both the Maillard reaction (MR) and thermal treatment influence the nutritional value of milk. In this paper, the capability of polyphenolic berry extract (PBE) to inhibit MR in an ultra-high temperature (UHT) treated milk was investigated. Total polyphenol content and antioxidant capacity of blueberry (BE) and raspberry extracts (RE) were also tested. A gas chromatography-mass spectrometry (GC-MS) method was developed to monitor the MR product N ε-(carboxymethyl)-L-lysine (CML) and L-lysine (LYS). PBE was added to milk at 0.05 and 0.1% w/v prior to UHT processing. Data revealed that formation of CML was significantly reduced (23.4 ± 5.1 %) by addition of 0.1% w/v BE. The final concentrations of LYS measured following the addition of PBE prior to thermal treatment were statistically similar to the control milk which was not subjected to thermal processing. Additionally, the metabolic profile of milk samples was investigated by GC-MS and visualised using ‘FancyTiles’

Special Issue "Hepatobiliary and Pancreatic Cancers: Novel Strategies for of Diagnosis and Treatments"

In recent years, hepato-pancreato-biliary (HPB) cancers have been increasing their incidence [...]

Field-Effect Transistors based on 2-D Materials: a Modeling Perspective

Two-dimensional (2D) materials are particularly attractive to build the channel of next-generation field-effect transistors (FETs) with gate lengths below 10-15 nm. Because the 2D technology has not yet reached the same level of maturity as its Silicon counterpart, device simulation can be of great help to predict the ultimate performance of 2D FETs and provide experimentalists with reliable design guidelines. In this paper, an ab initio modelling approach dedicated to well-known and exotic 2D materials is presented and applied to the simulation of various components, from thermionic to tunnelling transistors based on mono- and multi-layer channels. Moreover, the physics of metal - 2D semiconductor contacts is revealed and the importance of different scattering sources on the mobility of selected 2D materials is discussed. It is expected that modeling frameworks similar to the one described here will not only accompany future developments of 2D devices, but will also enable them

D-aspartic acid in vertebrate reproduction: Animal models and experimental designs

This article reviews the animal models and experimental designs that have been used during the past twenty years to demonstrate the prominent role played by d-aspartate (d-Asp) in the reproduction of vertebrates, from amphibians to humans. We have tabulated the findings of in vivo and in vitro experiments that demonstrate the effects of d-Asp uptake on hormone production and gametogenesis in vertebrate animal models. The contribution of each animal model to the existing knowledge on the role of d-Asp in reproductive processes has been discussed. A critical analysis of experimental designs has also been carried out. Experiments performed on wild animal species suggest a role of d-Asp in the mechanisms that regulate the reproductive cycle. Several in vivo and in vitro studies carried out on mouse and rat models have facilitated an understanding of the molecular pathways activated by D-Asp in both steroidogenesis and spermatogenesis, with particular emphasis on testosterone biosynthesis. Some attempts using d-Asp for the improvement of reproductive activity in animals of commercial interest have yielded mixed results. The increased transcriptome activity of enzymes and receptors involved in the reproductive activity in d-Asp-treated broiler roosters revealed further details on the mechanism of action of d-Asp on the reproductive processes. The close relationship between d-Asp and reproductive activity has emerged, particularly in relation to its effects exerted on semen quality, proposing therapeutic applications of this amino acid in andrology and in medically-assisted procreation techniques.This article reviews the animal models and experimental designs that have been used during the past twenty years to demonstrate the prominent role played by D-aspartate (D-Asp) in the reproduction of vertebrates, from amphibians to humans. We have tabulated the findings of in vivo and in vitro experiments that demonstrate the effects of D-Asp uptake on hormone production and gametogenesis in vertebrate animal models. The contribution of each animal model to the existing knowledge on the role of D-Asp in reproductive processes has been discussed. A critical analysis of experimental designs has also been carried out. Experiments performed on wild animal species suggest a role of D-Asp in the mechanisms that regulate the reproductive cycle. Several in vivo and in vitro studies carried out on mouse and rat models have facilitated an understanding of the molecular pathways activated by D-Asp in both steroidogenesis and spermatogenesis, with particular emphasis on testosterone biosynthesis. Some attempts using D-Asp for the improvement of reproductive activity in animals of commercial interest have yielded mixed results. The increased transcriptome activity of enzymes and receptors involved in the reproductive activity in D-Asptreated broiler roosters revealed further details on the mechanism of action of D-Asp on the reproductive processes. The close relationship between D-Asp and reproductive activity has emerged, particularly in relation to its effects exerted on semen quality, proposing therapeutic applications of this amino acid in andrology and in medically-assisted procreation techniques

CA19.9 Serum Level Predicts Lymph-Nodes Status in Resectable Pancreatic Ductal Adenocarcinoma: A Retrospective Single-Center Analysis

BackgroundThe choice between upfront surgery or neoadjuvant treatments (NAT) for resectable pancreatic ductal adenocarcinoma (R-PDAC) is controversial. R-PDAC with potential nodal involvement could benefit from NT. Ca (Carbohydrate antigen) 19.9 and serum albumin levels, alone or in combination, have proven their efficacy in assessing PDAC prognosis. The objective of this study was to evaluate the role of Ca 19.9 serum levels in predicting nodal status in R-PDAC.MethodsPreoperative Ca 19.9, as well as serum albumin levels, of 165 patients selected for upfront surgery have been retrospectively collected and correlated to pathological nodal status (N), resection margins status (R) and vascular resections (VR). We further performed ROC curve analysis to identify optimal Ca 19.9 cut-off for pN+, R+ and vascular resection prediction.ResultsIncreased Ca 19.9 levels in 114 PDAC patients were significantly associated with pN+ (p <0.001). This ability, confirmed in all the series by ROC curve analysis (Ca 19.9 >= 32 U/ml), was lost in the presence of hypoalbuminemia. Furthermore, Ca 19.9 at the cut off >418 U/ml was significantly associated with R+ (87% specificity, 36% sensitivity, p 0.014). Ca 19.9, at the cut-off >78 U/ml, indicated a significant trend to predict the need for VR (sensitivity 67%, specificity 53%; p = 0.059).ConclusionsIn R-PDAC with normal serum albumin levels, Ca 19.9 predicts pN+ and R+, thus suggesting a crucial role in deciding on NAT

Proteomic snapshot of the EGF-induced ubiquitin network

In this work, the authors report the first proteome-wide analysis of EGF-regulated ubiquitination, revealing surprisingly pervasive growth factor-induced ubiquitination across a broad range of cellular systems and signaling pathways

Quantitative analysis reveals how EGFR activation and downregulation are coupled in normal but not in cancer cells

Ubiquitination of the epidermal growth factor receptor (EGFR) that occurs when Cbl and Grb2 bind to three phosphotyrosine residues (pY1045, pY1068 and pY1086) on the receptor displays a sharp threshold effect as a function of EGF concentration. Here we use a simple modelling approach together with experiments to show that the establishment of the threshold requires both the multiplicity of binding sites and cooperative binding of Cbl and Grb2 to the EGFR. While the threshold is remarkably robust, a more sophisticated model predicted that it could be modulated as a function of EGFR levels on the cell surface. We confirmed experimentally that the system has evolved to perform optimally at physiological levels of EGFR. As a consequence, this system displays an intrinsic weakness that causes—at the supraphysiological levels of receptor and/or ligand associated with cancer—uncoupling of the mechanisms leading to signalling through phosphorylation and attenuation through ubiquitination