Evaluating causal effects on time-to-event outcomes in an RCT in Oncology with treatment discontinuation due to adverse events

In clinical trials, patients sometimes discontinue study treatments prematurely due to reasons such as adverse events. Treatment discontinuation occurs after the randomisation as an intercurrent event, making causal inference more challenging. The Intention-To-Treat (ITT) analysis provides valid causal estimates of the effect of treatment assignment; still, it does not take into account whether or not patients had to discontinue the treatment prematurely. We propose to deal with the problem of treatment discontinuation using principal stratification, recognised in the ICH E9(R1) addendum as a strategy for handling intercurrent events. Under this approach, we can decompose the overall ITT effect into principal causal effects for groups of patients defined by their potential discontinuation behaviour in continuous time. In this framework, we must consider that discontinuation happening in continuous time generates an infinite number of principal strata and that discontinuation time is not defined for patients who would never discontinue. An additional complication is that discontinuation time and time-to-event outcomes are subject to administrative censoring. We employ a flexible model-based Bayesian approach to deal with such complications. We apply the Bayesian principal stratification framework to analyse synthetic data based on a recent RCT in Oncology, aiming to assess the causal effects of a new investigational drug combined with standard of care vs. standard of care alone on progression-free survival. We simulate data under different assumptions that reflect real situations where patients' behaviour depends on critical baseline covariates. Finally, we highlight how such an approach makes it straightforward to characterise patients' discontinuation behaviour with respect to the available covariates with the help of a simulation study

2,4-Dinitro­benzaldehyde hydrazone

The title compound, C7H6N4O4, plays an important role in the synthesis of biologically active compounds. The planar hydrazone group is oriented at a dihedral angle of 8.27 (3)° with respect to the benzene ring. In the crystal structure, inter­molecular N—H⋯O and N—H⋯N hydrogen bonds link the mol­ecules

Influence of mixed-phase TiO2 on the activity of adsorption-plasma photocatalysis for total oxidation of toluene

Herein, the effects of different crystalline phases of TiO2 on the adsorption-plasma photocatalytic oxidation of toluene were investigated. First, photocatalysts loaded on a molecular sieve (MS) were characterised and the catalytic performance of toluene abatement was evaluated in a plasma system. The COx yield of the pure anatase (An) sample outperformed other samples in the adsorption-plasma photocatalytic oxidation process, especially for CO2 yield (69.1%). It was revealed that the highest space-time-yield of 2.35 gco(2)/Lcat.h was also achieved using plasma-An/MS. However, the highest total toluene abatement (99.5%) was achieved in the plasma-P25/MS system. The plasma-generated UV flux only played a minor role in photocatalyst activation because of the very low UV flux of 2.7 mu W/cm(2) generated by discharge. For the degradation pathway, compared with the plasma-MS system, byproducts of 1,3-Butadiyne (C4H2), guanidine, methyl-(C2H7N3) did not exist in the TiO2-assisted system, indicating a difference in the toluene degradation pathway. There were no obvious effects of different TiO2 samples on organic byproducts generation, and almost a complete mineralisation of all byproducts was observed after 30 min of treatment, with the exception of ethylamine (C2H7N) and acetaldehyde (C2H4O). Finally, a cycled adsorption-plasma study was conducted to reveal the sustainability of the process. A partial deactivation of plasma-An/MS with less than 7% decrease in CO2 selectivity after 7 cycles was revealed, which is a promising result for use in possible industrial applications

Preformed Pt nanoparticles supported on nanoshaped CeO2 for total propane oxidation

Pt-based catalysts have been widely used for the removal of short-chain volatile organic compounds (VOCs), such as propane. In this study, we synthesized Pt nanoparticles with a size of ca. 2.4 nm and loaded them on various fine-shaped CeO2 with different facets to investigate the effect of CeO2 morphology on the complete oxidation of propane. The Pt/CeO2-o catalyst with {111} facets exhibited superior catalytic activity compared to the Pt/CeO2-r catalyst with {110} and {100} facets. Specifically, the turnover frequency (TOF) value of Pt/CeO2-o was 1.8 times higher than that of Pt/CeO2-r. Moreover, Pt/CeO2-o showed outstanding long-term stability during 50 h. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed that the excellent performance of Pt/CeO2-o is due to the prevalence of metallic Pt species, which promotes C–C bond cleavage and facilitates the rapid removal of surface formate species. In contrast, a stronger metal–support interaction in Pt/CeO2-r leads to easier oxidation of Pt species and the accumulation of intermediates, which is detrimental to the catalytic activity. Our work provides insight into the oxidation of propane on different nanoshaped Pt/CeO2 catalysts.Peer ReviewedPostprint (published version

Near Real-Time InSAR Deformation Time Series Estimation With Modified Kalman Filter and Sequential Least Squares

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A wafer-scale two-dimensional platinum monosulfide ultrathin film via metal sulfurization for high performance photoelectronics

2D nonlayered materials have attracted enormous research interests due to their novel physical and chemical properties with confined dimensions. Platinum monosulfide as one of the most common platinum-group minerals has been less studied due to either the low purity in the natural product or the extremely high-pressure conditions for synthesis. Recently, platinum monosulfide (PtS) 2D membranes have emerged as rising-star materials for fundamental Raman and X-ray photoelectron spectral analysis as well as device exploration. However, a large-area homogeneous synthesis route has not yet been proposed and released. In this communication, we report a facile metal sulfurization strategy for the synthesis of a 4-inch wafer-scale PtS film. Enhanced characterization tools have been employed for thorough analysis of the crystal structure, chemical environment, vibrational modes, and atomic configuration. Furthermore, through theoretical calculations the phase diagram of the Pt–S compound has been plotted for showing the successful formation of PtS in our synthesis conditions. Eventually, a high-quality PtS film has been reflected in device demonstration by a photodetector. Our approach may shed light on the mass production of PtS films with precise control of their thickness and homogeneity as well as van der Waals heterostructures and related electronic devices