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Base Excision Repair Of Oxidative Dna Damage Coupled With Removal Of A Cag Repeat Hairpin Attenuates Trinucleotide Repeat Expansion, Meng Xu, Yanhao Lai, Justin Torner, Yanbin Zhang, Zunzhen Zhang, Yuan Liu Dec 2013

Base Excision Repair Of Oxidative Dna Damage Coupled With Removal Of A Cag Repeat Hairpin Attenuates Trinucleotide Repeat Expansion, Meng Xu, Yanhao Lai, Justin Torner, Yanbin Zhang, Zunzhen Zhang, Yuan Liu

Department of Chemistry and Biochemistry

Trinucleotide repeat (TNR) expansion is responsible for numerous human neurodegenerative diseases. However, the underlying mechanisms remain unclear. Recent studies have shown that DNA base excision repair (BER) can mediate TNR expansion and deletion by removing base lesions in different locations of a TNR tract, indicating that BER can promote or prevent TNR expansion in a damage location–dependent manner. In this study, we provide the first evidence that the repair of a DNA base lesion located in the loop region of a CAG repeat hairpin can remove the hairpin, attenuating repeat expansion. We found that an 8-oxoguanine located in the loop …


Application Of Receiver Operating Characteristic (Roc) Curves For Explosives Detection Using Different Sampling And Detection Techniques, Mimy Young, Wen Fan, Anna Raeva, Jose Almirall Dec 2013

Application Of Receiver Operating Characteristic (Roc) Curves For Explosives Detection Using Different Sampling And Detection Techniques, Mimy Young, Wen Fan, Anna Raeva, Jose Almirall

Department of Chemistry and Biochemistry

Reported for the first time are receiver operating characteristic (ROC) curves constructed to describe the performance of a sorbent-coated disk, planar solid phase microextraction (PSPME) unit for non-contact sampling of a variety of volatiles. The PSPME is coupled to ion mobility spectrometers (IMSs) for the detection of volatile chemical markers associated with the presence of smokeless powders, model systems of explosives containing diphenylamine (DPA), 2,4-dinitrotoluene (2,4-DNT) and nitroglycerin (NG) as the target analytes. The performance of the PSPME-IMS was compared with the widely accepted solid-phase microextraction (SPME), coupled to a GC-MS. A set of optimized sampling conditions for different volume …


Online Solid Phase Extraction Liquid Chromatography Tandem Mass Spectrometry (Spe-Lc-Ms/Ms) Method For The Determination Of Sucralose In Reclaimed And Drinking Waters And Its Photo Degradation In Natural Waters From South Florida, Sudha Rani Butchu, Natalia Quinete, Venkata R. Panditi, Piero R. Gardinali Aug 2013

Online Solid Phase Extraction Liquid Chromatography Tandem Mass Spectrometry (Spe-Lc-Ms/Ms) Method For The Determination Of Sucralose In Reclaimed And Drinking Waters And Its Photo Degradation In Natural Waters From South Florida, Sudha Rani Butchu, Natalia Quinete, Venkata R. Panditi, Piero R. Gardinali

Department of Chemistry and Biochemistry

Background

Sucralose has gained popularity as a low calorie artificial sweetener worldwide. Due to its high stability and persistence, sucralose has shown widespread occurrence in environmental waters, at concentrations that could reach up to several μg/L. Previous studies have used time consuming sample preparation methods (offline solid phase extraction/derivatization) or methods with rather high detection limits (direct injection) for sucralose analysis. This study described a faster and sensitive analytical method for the determination of sucralose in environmental samples.

Results

An online SPE-LC–MS/MS method was developed, being capable to quantify sucralose in 12 minutes using only 10 mL of sample, with …