Home About us Contact
|
Home About us Contact | ||
|
|
||
Complementary Data (complementary + data)
Selected AbstractsCapillary liquid chromatography/atmospheric-pressure matrix-assisted laser desorption/ionisation ion trap mass spectrometry: a comparison with liquid chromatography/matrix-assisted laser desorption/ionisation time-of-flight and liquid chromatography/electrospray ionisation quadrupole time-of-flight for the identification of tryptic peptidesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2006Colin S. Creaser The atmospheric-pressure matrix-assisted laser desorption/ionisation quadrupole ion trap (AP-MALDI-QIT) analysis of tryptic peptides is reported following capillary liquid chromatographic (LC) separation and direct analysis of a protein digest. Peptide fragments were identified by peptide mass fingerprinting from mass spectrometric data and sequence analysis obtained by tandem mass spectrometry of the principal mass spectral peaks using a data-dependent scanning protocol. These data were compared with those from mass spectrometric analysis using capillary LC/MALDI-time-of-flight (TOF) and capillary LC/electrospray ionisation (ESI)-quadrupole TOF. For all three configurations the resulting data were searched against the MSDB database, using MASCOT and the sequence coverage compared for each technique. Complementary data were obtained using the three techniques. Copyright © 2006 John Wiley & Sons, Ltd. [source] Rafts in oligodendrocytes: Evidence and structure,function relationshipGLIA, Issue 6 2006Ellen Gielen Abstract The plasma membrane of eukaryotic cells exhibits lateral inhomogeneities, mainly containing cholesterol and sphingomyelin, which provide liquid-ordered microdomains (lipid "rafts") that segregate membrane components. Rafts are thought to modulate the biological functions of molecules that become associated with them, and as such, they appear to be involved in a variety of processes, including signal transduction, membrane sorting, cell adhesion and pathogen entry. Although still a matter of ongoing debate, evidence in favor of the presence of these microdomains is gradually accumulating but a consensus on issues like their size, lifetime, composition, and biological significance has yet to be reached. Here, we provide an overview of the evidence supporting the presence of rafts in oligodendrocytes, the myelin-producing cells of the central nervous system, and discuss their functional significance. The myelin membrane differs fundamentally from the plasma membrane, both in lipid and protein composition. Moreover, since myelin membranes are unusually enriched in glycosphingolipids, questions concerning the biogenesis and functional relevance of microdomains thus appear of special interest in oligodendrocytes. The current picture of rafts in oligodendrocytes is mainly based on detergent methods. The robustness of such data is discussed and alternative methods that may provide complementary data are indicated. © 2006 Wiley-Liss, Inc. [source] Osteoporosis management: a perspective based on bisphosphonate data from randomised clinical trials and observational databasesINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 12 2009S. Boonen Summary Aims:, The efficacy of treatments for osteoporosis can be evaluated using a variety of study designs. This article aims to comprehensively review the evidence for bisphosphonate anti-fracture efficacy in postmenopausal women, discussing the strengths and limitations associated with each study method. Methods:, Literature analysis included English-language publications reporting results of randomised controlled trials (RCTs), post hoc analyses, meta analyses and observational studies evaluating the efficacy of alendronate (ALN), ibandronate (IBN), risedronate (RIS) and zoledronate (ZOL), with an initial sample size , 100 patients, and follow-up data for at least 1 year. Results:, Primary and secondary analyses of RCT data suggest differences among bisphosphonates with regard to site-specific anti-fracture efficacy and onset of fracture risk reduction. While some observational studies indicate differences in clinical outcomes among these agents, others report similar effectiveness. ALN and RIS data demonstrate sustained fracture protection for up to 10 and 7 years of treatment respectively. The efficacy of IBN and ZOL has been evaluated for up to 3 and 5 years respectively. Conclusions:, Understanding of the benefits of bisphosphonate treatment can be maximised by evaluating complementary data from RCTs and observational database studies. Fracture risk reduction with bisphosphonates is shown in RCTs and in real-world clinical settings. [source] Palaeoenvironmental evolution and sea-level fluctuations along the southeastern Pampa grasslands coast of Argentina during the Holocene,JOURNAL OF QUATERNARY SCIENCE, Issue 3 2006Isabel Vilanova Abstract Holocene pollen and diatom analyses and complementary data from ,18O and ,13C, malacology and sedimentology have provided a detailed record of vegetation history and palaeoenvironmental change at arroyo Las Brusquitas, on the southeastern coast of the pampas of Argentina especially in relation to past sea levels. Holocene palaeosalinity trends were estimated by Detrended Correspondence Analysis and by salinity indexes based on pollen and diatom data. As a consequence of sea-level rise from the postglacial an extensive wave-cut platform formed over which Holocene infilling sequences were deposited unconformably. In these sequences, variation in pollen and diatom assemblages occurred in agreement with changes in mollusc diversity and abundance, isotope values, and sediment deposits. Between ca. 6700 and 6190 14C yr BP (6279,6998,cal. yr BP) saline conditions predominated in an environment highly influenced by tides and salt water during the Holocene sea-level highstand. Between ca. 6200 and 3900 14C yr BP (4235,4608,cal. yr BP) shallow brackish water bodies formed surrounded by saltmarsh vegetation that became more widespread from 5180 14C yr BP (5830,6173,cal. yr BP) to 3900 14C yr BP in relation to a sea-level stabilisation period within the regression phase. Less saline conditions marked by frequent variations in salinity predominated between ca. 3900 and 2040,yr 14C BP (1830,2160,cal. yr BP). The intertidal saltmarsh environment changed into a brackish marsh dominated by freshwater conditions and sporadic tidal influence. Halophytic vegetation increased towards ca. 200014C yr BP indicating that saline conditions may be due to either desiccation or an unusually high tide range with rare frequency. After ca. 2000 14C yr BP the sedimentary sequences were buried by aeolian sand dunes. Changes in Holocene vegetation and environments in Las Brusquitas area are in agreement with data obtained from various southeastern coastal sites of the Pampa grasslands. Copyright © 2005 John Wiley & Sons, Ltd. [source] Raman spectroscopy of conducting poly (methyl methacrylate)/polyaniline dodecylbenzenesulfonate blendsJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2010Abdul Shakoor Abstract Polyaniline soluble in organic solvents was prepared using dodecylbenzenesulphonic acid (DBSA) as functional dopant. The solubility parameter was calculated and the most suitable solvent chloroform was checked for the solubility and the most compatible polymer PMMA was selected for blending. Miscibility was maximized with 1% by weight of hydroquinone. Blending of doped polyaniline with dodecylbenzenesulphonic acid (PAni.DBSA) in poly (methyl methacrylate) (PMMA) was explained by a change in the conformation of the polymeric chains leading to an increase in the conductivity. The electrical conductivity increased as the weight percent of PAni.DBSA increased, showing a percolation threshold as low as 3.0% by weight and the highest conductivity was achieved at 20% by wt of PAni.DBSA. Scanning electron micrographs showed lowest level of phase separation. Raman spectroscopy is used to characterize the blending process of two polymers aiming to understand the transformations in different types of charged segments. Raman results give complementary data about the blending process showing that together with the structural change of the polymeric chains, there is also a chemical transformation of these polymers. Analysis of Raman spectra was done investigating the relative intensities of the bands at 574 cm,1 and 607 cm,1. A relationship between conductivity and Raman was also proposed. Copyright © 2009 John Wiley & Sons, Ltd. [source] DNA barcodes for globally threatened marine turtles: a registry approach to documenting biodiversityMOLECULAR ECOLOGY RESOURCES, Issue 2 2010EUGENIA NARO-MACIEL Abstract DNA barcoding is a global initiative that provides a standardized and efficient tool to catalogue and inventory biodiversity, with significant conservation applications. Despite progress across taxonomic realms, globally threatened marine turtles remain underrepresented in this effort. To obtain DNA barcodes of marine turtles, we sequenced a segment of the cytochrome c oxidase subunit I (COI) gene from all seven species in the Atlantic and Pacific Ocean basins (815 bp; n = 80). To further investigate intraspecific variation, we sequenced green turtles (Chelonia mydas) from nine additional Atlantic/Mediterranean nesting areas (n = 164) and from the Eastern Pacific (n = 5). We established character-based DNA barcodes for each species using unique combinations of character states at 76 nucleotide positions. We found that no haplotypes were shared among species and the mean of interspecific variation ranged from 1.68% to 13.0%, and the mean of intraspecific variability was relatively low (0,0.90%). The Eastern Pacific green turtle sequence was identical to an Australian haplotype, suggesting that this marker is not appropriate for identifying these phenotypically distinguishable populations. Analysis of COI revealed a north,south gradient in green turtles of Western Atlantic/Mediterranean nesting areas, supporting a hypothesis of recent dispersal from near equatorial glacial refugia. DNA barcoding of marine turtles is a powerful tool for species identification and wildlife forensics, which also provides complementary data for conservation genetic research. [source] Electrospray ionisation with selected reaction monitoring for the determination of Mn-citrate, Fe-citrate, Cu-citrate and Zn-citrateRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 15 2009Volker Nischwitz Citrate complexes of Mn and Fe, and potentially those of Cu and Zn, are considered as important low molecular mass species in human serum and cerebrospinal fluid (CSF). For example, Mn is supposed to enter the brain under excess exposure as Mn-citrate leading to neurotoxic effects. Mn-citrate has been characterised in human CSF using chromatography and electrophoresis online with inductively coupled plasma mass spectrometry, but not yet with molecular mass spectrometry. Therefore, this study explores the potential of electrospray ionisation (ESI) with selected reaction monitoring (SRM) for the detection of metal-citrate complexes, in particular Mn-citrate. The collision-induced dissociation of precursor ions with various metal:citrate stoichiometries was studied for Mn-citrate, Fe-citrate, Cu-citrate and Zn-citrate. High selectivity was achieved for Mn(II)-citrate even in respect to Fe(III)-citrate which forms isobaric precursor ions. The limit of detection for Mn-citrate was estimated to be around 250,µg,L,1 (referring to the total Mn content in the standard) using flow injection. The sensitivity was sufficient for the determination of Mn-citrate in standard solutions and in an extract of an Mn-citrate-containing supplement. An improved ESI source design is expected to reduce the limits of detection significantly. The developed ESI-SRM method has the potential to provide complementary data for the quality control of current separation methods for metal citrates using element-selective detection, with application to biomedical samples and further matrices. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||