Analysis of amino acids by gas-liquid chromatography: The development of a method and its application

Ion exchange chromatography is the most widely used method for the analysis of amino acids. However, in respect of economy, speed, sensitivity and resolving power, gas liquid chromatography is potentially better than the conventional amino acid analyser. The technique requires that the amino acids be converted into some suitable volatile derivative prior to their separation by GLC. N-acetyl amino acid methyl esters were examined with regard to their suitability for gas chromatographic analysis, but were found to be not sufficiently volatile. When the N-trifluoroacetyl methyl esters were investigated no single column was found on which all of the amine acids could be resolved. However, it was found possible to separate all of the N-trifluoroacetyl methyl esters of the twenty amino acids which occur in proteins by using two columns - one coated with NPGS (neopentyl glycol succinate polyester) and the other coated with a mixture of DEGS (diethylene glycol suecinate) EGSS-X (ethylene glycol succinate polyenter chemically combined with a methyl silicone) and EGSP-Z (ethylene glycol suceinate polyester chemically combined with a methyl silicone). No better resolution of the N-trifluoroacetyl n-propyl or n-butyl esters of the amino acids was obtained when these derivatives were chromatographed on a number of columns than had seen achieved with the N-trifluoroacetyl methyl esters. Taking the response of the flame ionisation detector to N-trifluoroacetyl leucine methyl estor as unity, the response of the detector to the corresponding derivatives of the other amino acids was determined. Good reproducibility in the response factors was observed on both of the columns used for all of the amino acid derivatives with the exception of histidine, tryptophan and cystine. In order to assess the potential of the method, it was applied to hydrolysates of a number of pure peptides and also to mothanolysates of these peptides, prepared with methanol/HCI. Good agreement was obtained by both procedures. However, when the method wasapplied to poptides which had been elated from peptide maps, the results were poor. This was found to be due to the fact that a considerable amount of material was elated from the chromatography cower which produced spurious peaks on the chromatograms. When the method was applied to the analysis of hydrolysates of cytochrome c, insulin and bovine serua albumen, the results obtained were in poor agreement with the results of amino acid analysis carried out on the amino acid analyser. The chromatogram obtained from a methanolysate of cytochrome c gave reduced values for a number of amine acids such as valine and isoleucine. It appears that under the conditions of mothanolysis used, cleavage of bonds involving these amino acids does not proceed to completion. Butanolysis of leucylglyeylglycine was found to be much more rapid than methanolysis of this peptide, and so the N-trifluoroacetyl n-butyl esters of the amino acids map be more suitable derivatives for GLC studies

Supplemental prophylactic intervention for chemotherapy-induced nausea and emesis (spice) trial: Protocol for a multi-centre double-blind placebo-controlled randomized trial

Aim: There is significant recent interest in the role of ginger root (Zingiber officinale) as an adjuvant therapy for chemotherapy‐induced nausea. The supplemental prophylactic intervention for chemotherapy‐induced nausea and emesis (SPICE) trial aims to assess the efficacy by reduced incidence and severity of chemotherapy‐induced nausea and vomiting, and enhanced quality of life, safety and cost effectiveness of a standardised adjuvant ginger root supplement in adults undergoing single‐day moderate‐to‐highly emetogenic chemotherapy. Methods: Multisite, double‐blind, placebo‐controlled randomised trial with two parallel arms and 1:1 allocation. The target sample size is n = 300. The intervention comprises four capsules of ginger root (totalling 60 mg of active gingerols/day), commencing the day of chemotherapy and continuing for five days during chemotherapy cycles 1 to 3. The primary outcome is chemotherapy‐induced nausea‐related quality of life. Secondary outcomes include nutrition status; anticipatory, acute and delayed nausea and vomiting; fatigue; depression and anxiety; global quality of life; health service use and costs; adverse events; and adherence. Results: During the five‐month recruitment period from October 2017 to April 2018 at site A only, a total of n = 33 participants (n = 18 female) have been enrolled in the SPICE trial. Recruitment is expected to commence at Site B in May 2018. Conclusions: The trial is designed to meet research gaps and could provide evidence to recommend specific dosing regimens as an adjuvant for chemotherapy‐induced nausea and vomiting prevention and management.No Full Tex

The Atacama Cosmology Telescope: Dusty Star-Forming Galaxies and Active Galactic Nuclei in the Southern Survey

We present a catalog of 191 extragalactic sources detected by the Atacama Cosmology Telescope (ACT) at 148 GHz and/or 218 GHz in the 2008 Southern survey. Flux densities span 14-1700 mJy, and we use source spectral indices derived using ACT-only data to divide our sources into two sub-populations: 167 radio galaxies powered by central active galactic nuclei (AGN), and 24 dusty star-forming galaxies (DSFGs). We cross-identify 97% of our sources (166 of the AGN and 19 of the DSFGs) with those in currently available catalogs. When combined with flux densities from the Australian Telescope 20 GHz survey and follow-up observations with the Australia Telescope Compact Array, the synchrotron-dominated population is seen to exhibit a steepening of the slope of the spectral energy distribution from 20 to 148 GHz, with the trend continuing to 218 GHz. The ACT dust-dominated source population has a median spectral index of 3.7+0.62-0.86, and includes both local galaxies and sources with redshifts as great as 5.6. Dusty sources with no counterpart in existing catalogs likely belong to a recently discovered subpopulation of DSFGs lensed by foreground galaxies or galaxy groups.Comment: 13 pages, 8 figures, 4 table

The Atacama Cosmology Telescope: The LABOCA/ACT Survey of Clusters at All Redshifts

We present a multi-wavelength analysis of eleven Sunyaev Zel'dovich effect (SZE)-selected galaxy clusters (ten with new data) from the Atacama Cosmology Telescope (ACT) southern survey. We have obtained new imaging from the Large APEX Bolometer Camera (345GHz; LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope, the Australia Telescope Compact Array (2.1GHz; ATCA), and the Spectral and Photometric Imaging Receiver (250, 350, and $500\,\rm\mu m$; SPIRE) on the Herschel Space Observatory. Spatially-resolved 345GHz SZE increments with integrated S/N > 5 are found in six clusters. We compute 2.1GHz number counts as a function of cluster-centric radius and find significant enhancements in the counts of bright sources at projected radii $\theta < \theta_{2500}$. By extrapolating in frequency, we predict that the combined signals from 2.1GHz-selected radio sources and 345GHz-selected SMGs contaminate the 148GHz SZE decrement signal by ~5% and the 345GHz SZE increment by ~18%. After removing radio source and SMG emission from the SZE signals, we use ACT, LABOCA, and (in some cases) new Herschel SPIRE imaging to place constraints on the clusters' peculiar velocities. The sample's average peculiar velocity relative to the cosmic microwave background is $153\pm 383\,\rm km\,s^{-1}$.Comment: 19 pages, 11 figures, Accepted for Publication in The Astrophysical Journa

The Atacama Cosmology Telescope: Temperature and Gravitational Lensing Power Spectrum Measurements from Three Seasons of Data

We present the temperature power spectra of the cosmic microwave background (CMB) derived from the three seasons of data from the Atacama Cosmology Telescope (ACT) at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. We detect and correct for contamination due to the Galactic cirrus in our equatorial maps. We present the results of a number of tests for possible systematic error and conclude that any effects are not significant compared to the statistical errors we quote. Where they overlap, we cross-correlate the ACT and the South Pole Telescope (SPT) maps and show they are consistent. The measurements of higher-order peaks in the CMB power spectrum provide an additional test of the Lambda CDM cosmological model, and help constrain extensions beyond the standard model. The small angular scale power spectrum also provides constraining power on the Sunyaev-Zel'dovich effects and extragalactic foregrounds. We also present a measurement of the CMB gravitational lensing convergence power spectrum at 4.6-sigma detection significance.Comment: 21 pages; 20 figures, Submitted to JCAP, some typos correcte

A Map of the Nanoworld: Sizing up the Science, Politics, and Business of the Infinitesimal

Mapping out the eight main nodes of nanotechnology discourse that have emerged in the past decade, we explore how various scientific, social, and ethical islands of discussion have developed, been recognized, and are being continually renegotiated. We do so by (1) identifying the ways in which scientists, policy makers, entrepreneurs, educators, and environmental groups have drawn boundaries on issues relating to nanotechnology; (2) describing concisely the perspectives from which these boundaries are drawn; and (3) exploring how boundaries on nanotechnology are marked and negotiated by various nodes of nanotechnology discourse.Comment: 25 page