Search results for " Phase"
showing 10 items of 1862 documents
Recent Advances in Sample Preparation for Pesticide Analysis
2012
Much progress has been made in pesticide analysis in the past decade. During this time, hyphenated techniques involving highly efficient separation with sensitive mass spectrometric detection have become the methods of choice. Even with such powerful instrumental techniques, a demanding task in pesticide residue analysis is the development of multiresidue methods for the determination of pesticides in air, water, soil, sediment, biota, and food. This chapter summarizes the analytical characteristics of the different methods of sample preparation for the determination of pesticide residues in a variety of food matrices, and surveys their recent applications in combination with gas chromatogr…
A Case of Follicular Tumor of Uncertain Malignant Potential (FT-UMP) with Glomeruloid Features Showing Capsular Mucinous Degeneration
2021
The most recent revision of the World Health Organization (WHO) Classification of Tumours of Endocrine Organs introduced a new variant of follicular thyroid carcinoma (FTC). It is characterized by a “glomeruloid” architectural pattern of growth. We present a case of follicular tumor with glomeruloid features, with Alcian Blue positive mucinous stromal degeneration in foci of questionable capsular microinvasion. At our knowledge, this the second case of glomeruloid follicular tumor in the literature and the first case in which Alcian Blue staining was used to investigate capsular invasion. Moreover, RAS mutation further supports that this is a variant of follicular tumor with uncertain malig…
Response and Recovery of Brain Acetylcholinesterase Activity in the European Eel,Anguilla anguilla,Exposed to Fenitrothion
1998
European eel (Anguilla anguilla) were exposed to sublethal fenitrothion concentrations in a continuous flow-through system for 4 days. Brain acetylcholinesterase (AChE) activity was evaluated after 2, 8, 12, 24, 32, 48, 56, 72, and 96 h pesticide exposure. Results indicated that AChE activity in eel brains decreased as the concentration of fenitrothion increased. The pesticide induced significant inhibitory effects on the AChE activity ofA. anguilla,ranging from >40% inhibition at a sublethal concentration of 0.02 ppm to >60% inhibition at a sublethal concentration of 0.04 ppm. Eel were exposed to both fenitrothion concentrations for 96 h and then allowed a period of recovery in pesticide-f…
Human Embryonic Stem Cell Derived Hepatocyte-Like Cells as a Tool for In Vitro Hazard Assessment of Chemical Carcinogenicity
2011
Hepatocyte-like cells derived from the differentiation of human embryonic stem cells (hES-Hep) have potential to provide a human relevant in vitro test system in which to evaluate the carcinogenic hazard of chemicals. In this study, we have investigated this potential using a panel of 15 chemicals classified as noncarcinogens, genotoxic carcinogens, and nongenotoxic carcinogens and measured whole-genome transcriptome responses with gene expression microarrays. We applied an ANOVA model that identified 592 genes highly discriminative for the panel of chemicals. Supervised classification with these genes achieved a cross-validation accuracy of > 95%. Moreover, the expression of the response g…
Non-Invasive Assessment of LV Systolic Function and Diastolic Filling at Rest and During Exercise in Coronary Heart Disease
1985
In the assessment of the main determinants of cardiac function the study of the systolic phase and diastolic filling appear to be of paramount importance[1–3].
Everything you wanted to know about phase and reference frequency in one- and two-dimensional NMR spectroscopy
2019
The fundamental concept of phase discussed in this tutorial aimed at providing students with an explanation of the delays and processing parameters they may find in nuclear magnetic resonance (NMR) pulse programs. We consider the phase of radio-frequency pulses, receiver, and magnetization and how all these parameters are related to phases and offsets of signals in spectra. The impact of the off-resonance effect on the phase of the magnetization is discussed before presenting an overview of how adjustment of the time reference of the free induction decay avoids first-order correction of the phase of spectra. The main objective of this tutorial is to show how the relative phase of a pulse an…
Solid-Phase Extraction and Clean-Up Procedures in Pharmaceutical Analysis
2012
Solid-phase extraction (SPE) using small cartridges filled with sorbents of a small particle size has rapidly established itself as an important sample clean-up technique. It has prospered at the expense of liquid-liquid extraction (LLE), which is considered labor intensive and frequently plagued by problems, such as emulsion formation and use of large volumes of hazardous solvents. A remarkable characteristic of SPE is its easy adaptation to on-line mode by column-switching techniques; switching can be effected manually or by automated controllers. The same analyte/sorbent interactions that are exploited in liquid chromatography (LC) are of use in SPE, but particle sizes employed are great…
Nucleation and cavitation in parahydrogen
2012
We have used a density functional approach to investigate thermal homogeneous nucleation and cavitation in parahydrogen. The effect of electrons as seeds of heterogeneous cavitation in liquid parahydrogen is also discussed within the capillary model. (C) 2011 Elsevier B.V. All rights reserved.
Inhibitory effects oftrans-resveratrol analogs molecules on the proliferation and the cell cycle progression of human colon tumoral cells
2008
International audience; Resveratrol may function as a cancer chemopreventive agent. However, few data are available on the antitumoral activities of its dimer, epsilon-viniferin, also present in human diet. So, the effects of resveratrol, epsilon-viniferin, of their acetylated forms (resveratrol triacetate, epsilon-viniferin pentaacetate) and of vineatrol (a wine grape extract) were compared on human adenocarcinoma colon cells. Resveratrol and resveratrol triacetate inhibit cell proliferation and arrest cell cycle. epsilon-Viniferin and epsilon-viniferin pentaacetate slightly reduce cell proliferation. Vineatrol inhibits cell proliferation and favors an accumulation in the S phase of the ce…
The autoantigen La/SSB: detection on and uptake by mitotic cells.
1992
Abstract The nuclear autoantigen La, a transcription/termination factor of RNA polymerase III, was recently shown to translocalize to the cell surface of growth-stimulated cells during transition from G0- to G1-phase. Here we describe the staining of living mitotic cells with the anti-La mab La11G7. Moreover, La protein added to cell culture medium was able to enter into synchronized mitotic cells. Uptake was inhibited by the anti-La mab. La protein taken up into prophase cells assembled into a fibrillar network. Taken up by ana/telophase cells, La protein was preferentially transported into the newly forming or formed nuclei. This import allowed us to study directly the intranuclear locali…