Detection of pesticide residues on intact tomatoes by carbon fiber ionization mass spectrometry.

Trace and toxic pesticide residues may still remain on crops after harvest. Thus, maximum residual levels (MRLs) of pesticides on crops have been regulated. To determine whether the remaining pesticide residue level is below MRL, time-consuming sample pretreatment is needed prior to analysis of crop samples by suitable analytical tools.

Carbon fiber ionization mass spectrometry coupled with solid phase microextraction for analysis of Benzo[a]pyrene.

Solid phase micro-extraction (SPME) is an effective technique that can be used to selectively enrich trace analytes of interest from complex samples. Owing to its high sensitivity and high selectivity, mass spectrometry (MS) has been widely used as the detection tool to confirm the analytes enriched on SPME fibers. Generally, thermal desorption or solvent desorption is used to desorb analytes from SPME fibers for MS analysis.

Ultrasonication-assisted spray ionization-based micro-reactors for online monitoring of fast chemical reactions by mass spectrometry.

Microfluidics can be used to handle relatively small volumes of samples and to conduct reactions in microliter-sized volumes. Electrospray ionization can couple microfluidics with mass spectrometry (MS) to monitor chemical reactions online. However, fabricating microfluidic chips is time-consuming.

Carbon Fiber Ionization Mass Spectrometry for the Analysis of Analytes in Vapor, Liquid, and Solid Phases.

Various ionization methods in mass spectrometry (MS) are available for the analysis of analytes with different properties. Nonetheless, the use of a single ionization method to analyze mixtures containing analytes with different polarities and volatilities in different phases at atmospheric pressure remains a challenge. Exploring an ionization method that can ionize small organics and large biomolecules with different properties for MS analysis is advantageous.

Inhibition of human alcohol and aldehyde dehydrogenases by aspirin and salicylate: assessment of the effects on first-pass metabolism of ethanol.

Previous studies have reported that aspirin significantly reduced the first-pass metabolism (FPM) of ethanol in humans thereby increasing adverse effects of alcohol. The underlying causes, however, remain poorly understood. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), principal enzymes responsible for metabolism of ethanol, are complex enzyme families that exhibit functional polymorphisms among ethnic groups and distinct tissue distributions.

MDM2 is overexpressed and regulated by the eukaryotic translation initiation factor 4E (eIF4E) in human squamous cell carcinoma of esophagus.

Background: We investigated the association between the increased eukaryotic translation initiation factor 4E (eIF4E) level and MDM2 overexpression in the esophageal cancer tissue and cells.

Methods: This was a retrospective study of specimens from esophageal cancer patients treated over a 5-year period in a Taiwan university hospital. The predictor variable was eIF4E level in esophageal tumors and CE48T/VGH and TE6 esophageal carcinoma cell lines.

Nuclear epidermal growth factor receptor (EGFR) interacts with signal transducer and activator of transcription 5 (STAT5) in activating Aurora-A gene expression.

Loss of the maintenance of genetic material is a critical step leading to tumorigenesis. It was reported that overexpression of Aurora-A and the constitutive activation of the epidermal growth factor (EGF) receptor (EGFR) are implicated in chromosome instability. In this study, we examined that when cells treated with EGF result in centrosome amplification and microtubule disorder, which are critical for genetic instability.