Clinical statistical analysis plan for the ACCURE trial:the effect of appendectomy on the clinical course of ulcerative colitis, a randomised international multicentre trial

Background: The primary treatment of ulcerative colitis (UC) is medical therapy using a standard step-up approach. An appendectomy might modulate the clinical course of UC, decreasing the incidence of relapses and reducing need for medication. The objective of the ACCURE trial is to assess the efficacy of laparoscopic appendectomy in addition to standard medical treatment in maintaining remission in UC patients. This article presents the statistical analysis plan to evaluate the outcomes of the ACCURE trial. Design and methods: The ACCURE trial was designed as a multicentre, randomised controlled trial. UC patients with a new diagnosis or a disease relapse within the past 12 months, treated with 5-ASA, corticosteroids, or immunomodulators until complete clinical and endoscopic remission (defined as total Mayo score < 3 with endoscopic subscore of 0 or 1), were counselled for inclusion. Also, patients previously treated with biologicals who had a washout period of at least 3 months were considered for inclusion. Patients were randomised (1:1) to laparoscopic appendectomy plus maintenance treatment or a control group (maintenance therapy only). The primary outcome is the 1-year UC relapse rate (defined as a total Mayo-score ≥ 5 with endoscopic subscore of 2 or 3, or clinically as an exacerbation of symptoms and rectal bleeding or FCP > 150 or intensified medical therapy other than 5-ASA therapy). Secondary outcomes include number of relapses per patient, time to first relapse, disease activity, number of colectomies, medication usage, and health-related quality of life. Discussion: The ACCURE trial will provide comprehensive evidence whether adding an appendectomy to maintenance treatment is superior to maintenance treatment only in maintaining remission in UC patients. Trial registration: Dutch Trial Register (NTR) NTR2883. Registered May 3, 2011. ISRCTN, ISRCTN60945764. Registered August 12, 2019

Graphene-based strain sensing in composites for structural and health monitoring applications

Copyright © 2022 The Author(s). Composite structures are attracting more interest due to their outstanding mechanical properties; thus, their inspection and health assessment are key items for their safe use. In this article we present a graphene-based sensor that evaluates the strain generated within a composite. A finite element model was developed to investigate the mechanism driving the graphene to act as a strain sensor. A prototype sensor was manufactured, using a commercially available graphene ink. The strain in composite samples was measured and the gauge factor identified by applying different load scenarios. The graphene sensor proved to be able to evaluate strain at various levels providing a gauge factor (exceeding 6) higher than commercially available strain gauges.Innovate UK for the project GRAPHOSITE “A Graphene Sensor for Defect Detection and Predictive Maintenance in Composite Materials” [grant number 104266]

Energy transfer in aggregated CuInS2/ZnS core-shell quantum dots deposited as solid films

We report on the morphology and optical properties of CuInS2/ZnS core-shell quantum dots in solid films by means of AFM, SEM, HRTEM, steady state and time-resolved photoluminescence (PL) spectroscopy. The amount of aggregation of the CuInS2/ZnS QDs was controlled by changing the preparation conditions of the films. A red-shift of the PL spectrum of CuInS2/ZnS core-shell quantum dots, deposited as solid films on silicon substrates, is observed upon increasing the amount of aggregation. The presence of larger aggregates was found to lead to a larger PL red-shift. Besides, as the degree of aggregation increased, the PL decay became slower. We attribute the observed PL red-shift to energy transfer from the smaller to the larger dots within the aggregates, with the emission being realized via a long decay recombination mechanism (100-200 ns), the origin of which is discussed. © 2016 IOP Publishing Ltd

Energy transfer in aggregated CuInS₂/ZnS core-shell quantum dots deposited as solid films

We report on the morphology and optical properties of CuInS2/ZnS core-shell quantum dots in solid films by means of AFM, SEM, HRTEM, steady state and time-resolved photoluminescence (PL) spectroscopy. The amount of aggregation of the CuInS2/ZnS QDs was controlled by changing the preparation conditions of the films. A red-shift of the PL spectrum of CuInS2/ZnS core-shell quantum dots, deposited as solid films on silicon substrates, is observed upon increasing the amount of aggregation. The presence of larger aggregates was found to lead to a larger PL red-shift. Besides, as the degree of aggregation increased, the PL decay became slower. We attribute the observed PL red-shift to energy transfer from the smaller to the larger dots within the aggregates, with the emission being realized via a long decay recombination mechanism (100-200 ns), the origin of which is discussed.</p

Organic solar cells of enhanced efficiency and stability using zinc oxide:zinc tungstate nanocomposite as electron extraction layer

In this work, the enhanced performance of inverted bulk heterojunction (BHJ) organic solar cells (OSCs) using zinc oxide (ZnO):polyoxometalate (POM), in particular sodium metatungstate (Na6H2W12O40), nanocomposite films as electron extraction layers (EELs) is demonstrated. The addition in the precursor solution of ZnO of sodium metatungstate results in the formation of ZnO:ZnWO4 nanocomposite as evidenced by X-ray diffraction, Fourier transform infrared and photoluminescence measurements. The formation of ZnO:ZnWO4 heterointerface reduces the work function of the nanocomposite material leading to a more favorable electron extraction/transport at the organic blend/electron transport layer interface. Additionaly, the amount of zinc interstitial defects is suppressed having a profound positive effect on device stability. As a result, simultaneously improved open-circuit voltage (Voc), short-circuit current density (Jsc) and fill factor (FF) are obtained in the devices using the ZnO:ZnWO4 nanocomposites. Therefore, both of the inverted BHJ OSCs composed of either poly (3-hexylthiophene) (P3HT):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) or P3HT:indene-C60 bisadduct (IC60BA) photoactive blends show a significant performance enhancement when using the nanocomposite electron extraction layer, exhibiting a 27% and 23%, respectively, improvement in their power conversion efficiency (PCE) values compared to the reference devices based on pristine ZnO. In addition, the devices with the ZnO:ZnWO4 layer exhibit a remarkable stability enhancement retaining 95% of their initial PCE value upon storage for 500 h. © 2019 Elsevier B.V

Expression of arylamine N-acetyltransferase in human intestine

Background—Arylamine N-acetyltransferases in humans (NAT1 and NAT2) catalyse the acetylation of arylamines including food derived heterocyclic arylamine carcinogens. Other substrates include the sulphonamide 5-aminosalicylic acid (5-ASA), which is an NAT1 specific substrate; N-acetylation of 5-ASA is a major route of metabolism. NAT1 and NAT2 are both polymorphic. 
Aims—To investigate NAT expression in apparently healthy human intestines in order to understand the possible role of NAT in colorectal cancer and in the therapeutic response to 5-ASA. 
Methods—The intestines of four organ donors were divided into eight sections. DNA was prepared for genotyping NAT1 and NAT2 and enzymic activities of NAT1 and NAT2 were determined in cytosols prepared from each section. Tissue was fixed for immunohistochemistry with specific NAT antibodies. Western blotting was carried out on all samples of cytosol and on homogenates of separated muscle and villi after microdissection. 
Results—NAT1 activity of all cytosols was greater than NAT2 activity. NAT1 and NAT2 activities correlated with the genotypes of NAT1 and NAT2 and with the levels of NAT1 staining determined by western blotting. The ratio of NAT1:NAT2 activities showed interindividual variations from 2 to 70. NAT1 antigenic activity was greater in villi than in muscle. NAT1 was detected along the length of the villi in the small intestine. In colon samples there was less NAT1 at the base of the crypts with intense staining at the tips. 
Conclusions—The interindividual variation in NAT1 and NAT2 in the colon could affect how individuals respond to exposure to specific NAT substrates including carcinogens and 5-ASA. 

 Keywords: arylamine N-acetyltransferase; 5-aminosalicylate; colorectal cancer; drug metabolism; inflammatory bowel disease; die

Synthesis of two tri-arylamine derivatives as sensitizers in dye-sensitized solar cells: Electron injection studies and photovoltaic characterization

WOS: 000331504500012Two organic sensitizers with the structure donor-pi-acceptor, having tri-arylamine as electron donor, cyano-acetic acid as electron acceptor and a phenyl or thiophene ring as pi-bridge, are synthesized. The synthetic procedure, the photophysical and electrochemical properties of both dyes are described in detail. In particular, cyclic voltammetry and spectroscopic measurements were performed while the energy gap between highest occupied and lowest unoccupied molecular orbital for both dyes was calculated. Besides, electron injection dynamics on a series of titanium dioxide nanostructured films sensitized with the two dyes were investigated with time resolved fluorescence spectroscopy using femtosecond temporal resolution, while nanostructured alumina films were used as reference. The photovoltaic performances of both dyes in quasi-solid state dye sensitized solar cells were also investigated. A maximum overall conversion efficiency of 3.8% was monitored for two micrometer thin titanium dioxide films and quasi-solid state electrolyte. The performances of the solar cells are explained in terms of photophysical properties and electron injection dynamics of both dyes. (C) 2013 Elsevier B.V. All rights reserved.European Union (European Social Fund - ESF)European Union (EU)European Social Fund (ESF); Greek National funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) [377756]; State Planning Organization of Turkey (DPT) [11-DPT-001]Prof. E. Stathatos would like to acknowledge that his research has been co-financed by the European Union (European Social Fund - ESF) and Greek National funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Thales MIS: 377756.; M. Can, S. Demic and S. Icli acknowledge the supports from the State Planning Organization of Turkey (DPT) for financial support through the project 11-DPT-001. Z.M. Yigit also thanks for Erasmus Student Exchange program for the visit to the Technological-Educational Institute of Western Greece. Finally, the authors would like also to thank Dr. Peter Hrobarik for useful discussions

Avoiding ambient air and light induced degradation in high-efficiency polymer solar cells by the use of hydrogen-doped zinc oxide as electron extraction material

Polymer solar cells have undergone rapid development in recent years. Their limited stability to environmental influence and during illumination, however, still remains a major stumbling block to the commercial application of this technology. Several attempts have been made to address the instability issue, mostly concentrated on the insertion of charge transport interlayers in the device stack. Although zinc oxide (ZnO) is one of the most common electron transport materials in those cells, the presence of defects at the surface and grain boundaries significantly affects the efficiency and stability of the working devices. To address these issues, we herein employ hydrogen-doping of ZnO electron extraction material. It is found that devices based on photoactive layers composed of blends of poly(3-hexylthiophene) (P3HT) with electron acceptors possessing different energy levels, such as [6,6]-phenyl-C70butyric acid methyl ester (PC70BM) or indene-C60 bisadduct (IC60BA) essentially enhanced their photovoltaic performance when using the hydrogen-doped ZnO with maximum power conversion efficiency (PCE) reaching values of 4.62% and 6.65%, respectively, which are much higher than those of the cells with the pristine ZnO (3.08% and 4.51%). Most significantly, the degradation of non-encapsulated solar cells when exposed to ambient or under prolonged illumination is studied and it is found that devices based on un-doped ZnO showed poor environmental stability and significant photo-degradation while those using hydrogen-doped ZnO interlayers exhibited high long-term ambient stability and maintained nearly 80–90% of their initial PCE values after 40 h of 1.5 AM illumination. All mechanisms responsible for this enhanced stability are elucidated and corresponding models are proposed. This work successfully addresses and tackles the instability problem of polymer solar cells and the key findings pave the way for the upscaling of these and, perhaps, of related devices such as perovskite solar cells. © 2017 Elsevier Lt