Fast and Highly Sensitive Ionic‐Polymer‐Gated WS2–Graphene Photodetectors

The combination of graphene with semiconductor materials in heterostructure photodetectors enables amplified detection of femtowatt light signals using micrometer‐scale electronic devices. Presently, long‐lived charge traps limit the speed of such detectors, and impractical strategies, e.g., the use of large gate‐voltage pulses, have been employed to achieve bandwidths suitable for applications such as video‐frame‐rate imaging. Here, atomically thin graphene–WS₂ heterostructure photodetectors encapsulated in an ionic polymer are reported, which are uniquely able to operate at bandwidths up to 1.5 kHz whilst maintaining internal gain as large as 10⁶. Highly mobile ions and the nanometer‐scale Debye length of the ionic polymer are used to screen charge traps and tune the Fermi level of the graphene over an unprecedented range at the interface with WS₂. Responsivity R = 10⁶ A W^?1 and detectivity D* = 3.8 × 10¹¹ Jones are observed, approaching that of single‐photon counters. The combination of both high responsivity and fast response times makes these photodetectors suitable for video‐frame‐rate imaging applications.     

Validation of Tuba1a as Appropriate Internal Control for Normalization of Gene Expression Analysis during Mouse Lung Development

The expression ratio between the analysed gene and an internal control gene is the most widely used normalization method for quantitative RT-PCR (qRT-PCR) expression analysis. The ideal reference gene for a specific experiment is the one whose expression is not affected by the different experimental conditions tested. In this study, we validate the applicability of five commonly used reference genes during different stages of mouse lung development. The stability of expression of five different reference genes (Tuba1a, Actb Gapdh, Rn18S and Hist4h4) was calculated within five experimental groups using the statistical algorithm of geNorm software. Overall, Tuba1a showed the least variability in expression among the different stages of lung development, while Hist4h4 and Rn18S showed the maximum variability in their expression. Expression analysis of two lung specific markers, surfactant protein C (SftpC) and Clara cell-specific 10 kDA protein (Scgb1a1), normalized to each of the five reference genes tested here, confirmed our results and showed that incorrect reference gene choice can lead to artefacts. Moreover, a combination of two internal controls for normalization of expression analysis during lung development will increase the accuracy and reliability of results.     

Gastric Adenocarcinomas and Signet-Ring Cell Carcinoma: Unraveling Gastric Cancer Complexity through Microbiome Analysis—Deepening Heterogeneity for a Personalized Therapy

Gastric cancer (GC) is the fifth most prevalent cancer worldwide and the third leading cause of global cancer mortality. With the advances of the omic studies, a heterogeneous GC landscape has been revealed, with significant molecular diversity. Given the multifaceted nature of GC, identification of different patient subsets with prognostic and/or predictive outcomes is a key aspect to allow tailoring of specific treatments. Recently, the involvement of the microbiota in gastric carcinogenesis has been described. To deepen this aspect, we compared microbiota composition in signet-ring cell carcinoma (SRCC) and adenocarcinoma (ADC), two distinct GC subtypes. To this purpose, 10 ADC and 10 SRCC and their paired non-tumor (PNT) counterparts were evaluated for microbiota composition through 16S rRNA analysis. Weighted and unweighted UniFrac and Bray–Curtis dissimilarity showed significant community-level separation between ADC and SRCC. Through the LEfSe (linear discriminant analysis coupled with effect size) tool, we identified potential microbial biomarkers associated with GC subtypes. In particular, SRCCs were significantly enriched in the phyla Fusobacteria, Bacteroidetes, Patescibacteria, whereas in the ADC type, Proteobacteria and Acidobacteria phyla were found. Overall, our data add new insights into GC heterogeneity and may contribute to deepening the GC classification.     

Click-Chemistry (CuAAC) Trimerization of an αvβ6 Integrin Targeting Ga-68-Peptide: Enhanced Contrast for in-Vivo PET Imaging of Human Lung Adenocarcinoma Xenografts

α_vβ₆ Integrin is an epithelial transmembrane protein that recognizes latency-associated peptide (LAP) and primarily activates transforming growth factor beta (TGF-β). It is overexpressed in carcinomas (most notably, pancreatic) and other conditions associated with α_vβ₆ integrin-dependent TGF-β dysregulation, such as fibrosis. We have designed a trimeric Ga-68-labeled TRAP conjugate of the α_vβ₆-specific cyclic pentapeptide SDM17 (cyclo[RGD-Chg-E]-CONH₂) to enhance α_vβ₆ integrin affinity as well as target-specific in-vivo uptake. Ga-68-TRAP(SDM17)₃ showed a 28-fold higher α_vβ₆ affinity than the corresponding monomer Ga-68-NOTA-SDM17 (IC₅₀ of 0.26 vs. 7.4 nM, respectively), a 13-fold higher IC₅₀-based selectivity over the related integrin α_vβ₈ (factors of 662 vs. 49), and a threefold higher tumor uptake (2.1 vs. 0.66 %ID/g) in biodistribution experiments with H2009 tumor-bearing SCID mice. The remarkably high tumor/organ ratios (tumor-to-blood 11.2; -to-liver 8.7; -to-pancreas 29.7) enabled high-contrast tumor delineation in PET images. We conclude that Ga-68-TRAP(SDM17)₃ holds promise for improved clinical PET diagnostics of carcinomas and fibrosis.     

Development of an experimental test rig for cogeneration based on a Stirling engine and a biofuel burner

A system consisting of a last-generation Stirling engine (SE) and a fuel burner for distributed power generation has been developed and experimentally investigated. The heat generated by the combustion of two liquid fuels, a standard Diesel fuel and a rapeseed oil, is used as a heat source for the SE, that converts part of the thermal energy into mechanical and then electric energy. The hot head of the SE is kept in direct contact with the flame generated by the burner. The burner operating parameters, designed for Diesel fuel, were changed to make it possible to burn vegetable oils, not suitable for internal combustion engines. The possibility of adopting different configurations of the combustion chamber was taken into account to increase the system efficiency. The preliminary configurations adopted allowed to operate this integrated system, obtaining an electric power up to 4.4 kW_el with a net efficiency of 11.6%.     

Critical Role for the Protons in FRTL-5 Thyroid Cells: Nuclear Sphingomyelinase Induced-Damage

Proliferating thyroid cells are more sensitive to UV-C radiations than quiescent cells. The effect is mediated by nuclear phosphatidylcholine and sphingomyelin metabolism. It was demonstrated that proton beams arrest cell growth and stimulate apoptosis but until now there have been no indications in the literature about their possible mechanism of action. Here we studied the effect of protons on FRTL-5 cells in culture. We showed that proton beams stimulate slightly nuclear neutral sphingomyelinase activity and inhibit nuclear sphingomyelin-synthase activity in quiescent cells whereas stimulate strongly nuclear neutral sphingomyelinase activity and do not change nuclear sphingomyelin-synthase activity in proliferating cells. The study of neutral sphingomyelinase/sphingomyelin-synthase ratio, a marker of functional state of the cells, indicated that proton beams induce FRTL-5 cells in a proapoptotic state if the cells are quiescent and in an initial apoptotic state if the cells are proliferating. The changes of cell life are accompanied by a decrease of nuclear sphingomyelin and increase of bax protein.     

Bijective Linear Time Coding and Decoding for k-Trees

The problem of coding labeled trees has been widely studied in the literature and several bijective codes that realize associations between labeled trees and sequences of labels have been presented. k-trees are one of the most natural and interesting generalizations of trees and there is considerable interest in developing efficient tools to manipulate this class of graphs, since many NP-Complete problems have been shown to be polynomially solvable on k-trees and partial k-trees. In 1970 Rényi and Rényi generalized the Prüfer code, the first bijective code for trees, to a subset of labeled k-trees. Subsequently, non redundant codes that realize bijection between k-trees (or Rényi k-trees) and a well defined set of strings were produced. In this paper we introduce a new bijective code for labeled k-trees which, to the best of our knowledge, produces the first coding and decoding algorithms running in linear time with respect to the size of the k-tree.