Plant protein phosphatase 2Cs (PP2Cs) function as inhibitors in protein kinase cascades involved in various processes and are crucial participants in both plant development and signaling pathways activated by abiotic stress. In this study, a genome-wide study was conducted on the gene family. A total of putative 117 genes were identified.
View Article and Find Full Text PDFPerfluoroalkyl and polyfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs) are chemicals that may contribute to placenta-mediated complications and adverse maternal-fetal health risks. Few studies have investigated these chemicals in relation to biomarkers of effect during pregnancy. We measured 12 PFASs and four urinary OPFR metabolites in 132 healthy pregnant women during mid-gestation and examined a subset with biomarkers of placental development and disease (n = 62).
View Article and Find Full Text PDFBackground: Perfluoroalkyl substances (PFAS) and polybrominated diphenyl ethers (PBDEs) are used in consumer products for their water repellent and flame retardant properties, respectively. However, there is widespread prenatal exposure and concern about their potential harm to the developing fetus. Here, we utilized data from a demographically diverse cohort of women in San Francisco, CA to examine associations between prenatal exposure to PFAS and PBDEs with gestational age and birth weight for gestational age z-scores.
View Article and Find Full Text PDFThe formation of multiple molecular ions, especially due to sodium adduct ion formation, is commonly observed in electrospray mass spectrometry and may make reproducible and sensitive quantitation difficult. The objective of this work was to investigate the underlying mechanism involved in the suppression of multiple molecular ion formation and to improve the sensitivity of detection for the two anti-neoplastic agents paclitaxel and docetaxel. The results showed that alkylamine additives could significantly improve the detection of paclitaxel and docetaxel by suppression of multiple molecular ions through preferential formation of a predominant alkylamine adduct ion.
View Article and Find Full Text PDFA liquid chromatography method using volatile ion-pairing reagents and tandem mass spectrometry was developed to obviate observed matrix effect for ionizable polar compounds. The present study investigated the addition of volatile ion-pair reagents to the reconstitution solution instead of the mobile phase to enhance the efficiency of chromatographic separation and minimize the sensitivity loss due to the formation of ion-pairs. The volatile ion-pair reagents used were perfluorinated carboxylic acids with n-alkyl chains: heptafluorobutanoic acid (HFBA), nonafluoropentanoic acid (NFPA), tridecafluoroheptanoic acid (TDFHA) and pentadecafluorooctanoic acid (PDFOA).
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
October 2005
High performance liquid chromatography with atmospheric pressure ionization (API) mass spectrometry has been essential to a large number of quantitative analytical applications for a variety of compounds. Poor detection sensitivity however is a problem observed for a number of analytes because detection sensitivity can be affected by many factors. The two most critical factors are the chemical and physical properties of the analyte and the composition of the mobile phase.
View Article and Find Full Text PDFThe objective of this study was to adopt a molecular modeling approach to understand changes in signal intensity due to adduct formation with short-chain alkylamines for two anticancer agents, paclitaxel and docetaxel, during electrospray mass spectrometric analysis. We describe a simple and intuitive modeling procedure using a comparison of hydropathic interaction (HINT) scores to explain differences in responses of amine adducts formed with the two analytes. The responses of paclitaxel and docetaxel were generally enhanced considerably (up to approximately 500% in some instances) on adding the amines.
View Article and Find Full Text PDFAim: To analyse the impurities of gatifloxacin.
Methods: The impurity of gatifloxacin were analysized and determinated by RP-HPLC/electrospray ionization mass spectrometry with a Zorbax SB-C18(4.6 mm x 150 mm ID, 5 microns).