Mejiajuul8744

In the last decade, wearable sensors have gained a key role on biomedical research field for reliable health state monitoring. A wide plethora of physics marker sensors is already commercially available, including activity tracker, heart rate devices, and fitness smartwatch. On the contrary, wearable and epidermal sensors for chemical biomarker monitoring in several biofluids are not ready yet. Herein, we report a wireless and flexible epidermal device for pH monitoring in sweat, fabricated by encompassing a screen-printed potentiometric sensor, an integrated circuit, and antenna embedded onto the same Kapton substrate. An iridium oxide film was electrodeposited onto the graphite working electrode providing the pH sensitive layer, while the integrated circuit board allows for data acquisition and storing. Furthermore, a radio frequency identification antenna surrounding the entire system enables data transmission to an external reader up to nearly 2 m in the most favourable case. The potentiometric sensor was firstly characterised by cyclic voltammetry experiments, then the iridium oxide electrodeposition procedure was optimised. Next, the sensor was tested toward pH detection in buffer solutions with a near-Nernstian response equal to -0.079 ± 0.002 V for unit of pH. Interference studies of common sweat ions, including Na+, K+ and Cl-, showed any influence on the pH sensor response. Finally, the integrated epidermal device was tested for real-time on-body pH sweat monitoring during a running activity. Data recorded for a running subject were wireless transmitted to an external receiver, showing a pH value close to 5.5, in agreement with value obtained by pH-meter reference measurement.Novel materials with high adsorption and desorption efficiencies are significant for studying compounds at ultra-trace level. Herein, covalent organic framework-graphene oxide (COF-GO) composite materials are synthesized, and tested for solid phase microextraction (SPME) of bisphenol A (BPA) at ultra-trace level. With GO modified successively by 3-aminopropyltriethoxysilane, 1,3,5-triformylphloroglucinol (Tp), and different ratios of COF monomers (Tp and benzidine (BD)), the composites of TpBD-GO-n (n = 1-4) are synthesized. By coating the composites on a glass fiber, the extraction performances of the composites for BPA are tested with constant flow desorption ionization mass spectrometry (CFDI-MS). The extraction efficiency of the composite TpBD-GO-2 is 2.2 and 4.7 times higher than those of TpBD and GO, respectively. The chromatographic separation becomes a non-essential step for detection of BPA, the analysis time for each sample is reduced to 8 min. The limits of detection and quantification of MS for BPA analysis are improved to be 22.2 and 73.9 ng L-1. The linear range is extended to be 10.0 μg L-1 (R2 = 0.9990), and the relative standard deviations of one fiber (n = 11) and fiber-to-fiber (n = 8) are 4.3% and 5.6% (1 μg L-1), respectively. With this method, ultra-trace levels of BPA present in river water and sea water samples can be successfully detected and quantified. The results indicate that the TpBD-GO-n composites possess superior extraction performance, and their various applications could be expected.Alkylated DNA adducts are the most important and common form of DNA damage at the molecular level. In addition to known alkylated DNA adducts, many unknown DNA adducts remain to be discovered. A prediction-driven MRM profiling MS strategy has been established for the rapid discovery of unknown DNA adducts induced by sulfonates. The innovative aspects and core of this strategy are the construction of the prediction MRM list, which includes 36 possible precursor ion and characteristic product ion transitions of DNA adducts based on MS fragmentation patterns, and then unknown DNA adducts 7-propyl guanine and 7-butyl guanine were discovered based on the diagnostic MRM signals of the DNA samples, and subsequently confirmed using high-resolution MS data and synthetic standards for the first time. Furthermore, DNA adducts, including newly found adducts in a human cell model and rat tissues after nitrosamine and sulfonate exposure, were unambiguously investigated by a UHPLC-MS/MS method. As a result, different alkyl methanesulfonates, including methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), PMS and BMS, all lead to the formation of 7MeG in addition to their own specific alkylation DNA adducts. TRP Channel inhibitor The ester group of the sulfonate determines the specific types of DNA adducts produced, and the sulfonate might undergo transesterification with the methyl donors that commonly exist in eukaryotic organisms such as SAM, resulting in the formation of MMS, which induce the generation of methyl DNA adducts after EMS, PMS and BMS exposure. Furthermore, similar DNA adduct profiles were presented in both human cells and rat tissues. This approach could be useful in the future for probing unknown DNA adducts and simultaneously profiling both known and unknown DNA adducts in both in vitro to in vivo settings to evaluate potential genotoxicities and cancer risks to populations exposed to genotoxins.Endogenous steroid hormones and endocannabinoids (ECs) are important regulators in the stress response of the human body. For the measurement of chronic stress, hair analysis has been established as method of choice for long-term and retrospective determination of endogenous stress markers. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of five steroid hormones (cortisone, cortisol, androstenedione, testosterone, progesterone) and four endocannabinoids (anandamide, palmitoylethanolamide, 2-arachidonylglycerol, oleoylethanolamide) in hair was developed and validated. The hair samples were extracted with methanol and cleaned up with a fully automated supported liquid extraction (SLE) before analysis. Special attention was paid to the difficulties accompanying the quantification of endogenous analytes in hair. Five different strategies for endogenous compound quantification in hair (surrogate analyte, standard addition, background correction, stripped matrix and solvent calibration) were tested and compared.