Influence of Volatile Organic Compound Adsorption on the Characteristics of Organic Field-Effect Transistors and Rules for Gas-Sensing Measurements.

Owing to the advantages of organic field-effect transistors (OFETs) in the versatility of organic synthesis, multiparameter measurement, and signal amplification, sensors based on OFETs have received increasing attention for detecting volatile organic compounds (VOCs). However, false device operation and gas-sensing measurements often occur to vitiate the advantages of OFETs and even output error gas-sensing signals. In this work, by experimentally and theoretically studying the effects of VOC adsorption on the operational characteristics of the OFET, the proper operations of OFETs in gas-sensing measurements were clarified. The multiparameter measurements of OFETs showed that the source-drain current was the optimized parameter for achieving high responsivity, and other OFET parameters could be used for fingerprint analysis. By operating OFETs in the near-threshold region, the amplification effect was switched to enhance the responsivity by orders of magnitude to VOCs, while in the overthreshold region, the OFETs had a low signal-to-noise ratio. Besides, a counteraction effect and an uncertainty effect were discovered, leading to error gas-sensing signals. A theoretical study was carried out to reveal the dependency of the gas-sensing properties of OFETs on VOC adsorption. A series of rules were proposed for guiding the measurements of OFET sensors by taking full advantage of transistors in gas-sensing applications.

Lymphocyte to monocyte ratio is associated with response to first-line platinum-based chemotherapy and prognosis of early-stage non-small cell lung cancer patients.

Lymphocyte to monocyte ratio (LMR) has shown prognostic value in different types of cancer. This study assessed the prognostic performance of LMR in early-stage non-small cell lung cancer (NSCLC) patients and investigated the influence of LMR on the treatment response in patients receiving first-line platinum-based chemotherapy. Four hundred eighty-eight NSCLC patients and 500 healthy donors were enrolled in this study. The cutoff value for LMR was chosen by receiver operating characteristic curve analysis. The prognostic significance of markers was assessed by univariate and multivariate Cox regression models. The median overall survival was 43 months, and the median progression-free survival was 38 months. LMR was associated with disease status and the treatment response of first-line platinum-based chemotherapy. Multivariate analysis showed that LMR was an independent prognostic factor for both overall survival (hazard ratio = 1.53, 95 % confidence interval = 1.09-2.14, P = 0.015) and progression-free survival (hazard ratio = 1.20, 95 % confidence interval = 1.02-1.67, P = 0.028). Furthermore, integration of LMR into a prognostic model including TNM stage, tumor status, chemotherapy, and histological type generated a nomogram, which predicted accurately overall survival for NSCLC patients. Decreased LMR may be a potential biomarker of disease status, worse response to first-line platinum-based chemotherapy, and worse survival for NSCLC patients. A prospective study is warranted for further validation of our findings.