Collision Energy and Cone Voltage Optimisation for Glycopeptide Analysis

2009 ◽  
Vol 15 (2) ◽  
pp. 361-365 ◽  
Author(s):  
Judit Krenyacz ◽  
László Drahos ◽  
Károly Vékey
Keyword(s):  
Aspartic Acid ◽  
Collision Energy ◽  
Cone Voltage ◽  
Peptide Analysis ◽  
Glycosylation Pattern ◽  
Low Mass ◽  
Suitable Standard ◽  
High Degree ◽  
Glycopeptide Analysis ◽  
Degree Of Fragmentation

Instrument tuning commonly used for peptide analysis and for proteomics causes a high degree of fragmentation for glycopeptides. This results in a strongly biased glycosylation pattern. To obtain correct results for glycopeptides, both the cone voltage and the collision energy has to be reduced significantly. A suitable standard for tuning the instrument for glycopeptide analysis is aspartic acid (which fragments under similar conditions as glycopeptides); while low mass sugar fragments (for example, at 657.3 Da) are good indicators for the presence/absence of glycopeptide fragmentation.

scholarly journals Forest fragmentation in the landscape in the Atlantic Forest Biome: A systematic review of the literature

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Stephany Diolino Cunha ◽  
Bruna Sampaio Crivilin ◽  
Matheus da Silva Araújo ◽  
Luís Antônio Coimbra Borges
Keyword(s):  
Systematic Review ◽  
Landscape Ecology ◽  
Forest Fragmentation ◽  
Atlantic Forest ◽  
Forest Fragments ◽  
Review Of The Literature ◽  
Search Terms ◽  
High Degree ◽  
Forest Biome ◽  
Degree Of Fragmentation

Forest fragmentation is defined as the process by which a continuous area of habitat is reduced in size and divided between spaces. Therefore, due to the increase in these areas, this study aimed to conduct a systematic review of the literature on forest fragments in the Atlantic Forest biome in order to verify their main characteristics and landscape ecology. Publications in search platforms referring to the period from 2000 to 2020 were analyzed such as: SciELO, Google academic and CAPES journals portal. The search terms entered were: “Studies of forest fragments in the Atlantic Forest biome” and “Landscape ecology in forest fragments”. A total of 15 articles were selected from among the works found, and 5 of these were chosen to be evaluated in the present study. Four of the five works were carried out in the state of Espírito Santo, close to basins and sub-basins, and only one work was carried out in a state park. Thus, the evaluated works with the theme, study of fragmentation and ecology of the landscape showed a high degree of fragmentation, meaning that they have fragments smaller than 5 hectares; in addition, all fragments have an irregular edge effect. Therefore, measures aimed at the conservation of biodiversity are needed in all places so that there is ecological restoration of the landscape and conservation of fauna and flora in the Atlantic Forest biome. 

scholarly journals Optimal Dissociation Methods Differ for N- and O-glycopeptides

2020 ◽  
Author(s):  
Nicholas Riley ◽  
Stacy A. Malaker ◽  
Marc D. Driessen ◽  
Carolyn Bertozzi
Keyword(s):  
Large Scale ◽  
Collision Energy ◽  
Electron Transfer Dissociation ◽  
Method Performance ◽  
Site Specific ◽  
Advantages And Disadvantages ◽  
Beam Type ◽  
Supplemental Activation ◽  
Glycopeptide Analysis

<p><a>Site-specific characterization of glycosylation requires intact glycopeptide analysis, and recent efforts have focused on how to best interrogate glycopeptides using tandem mass spectrometry (MS/MS). Beam-type collisional activation, i.e., higher-energy collisional dissociation (HCD), has been a valuable approach, but stepped collision energy HCD (sceHCD) and electron transfer dissociation with HCD supplemental activation (EThcD) have emerged as potentially more suitable alternatives. Both sceHCD and EThcD have been used with success in large-scale glycoproteomic experiments, but they each incur some degree of compromise. Most progress has occurred in the area N-glycoproteomics. There is growing interest in extending this progress to O-glycoproteomics, which necessitates comparisons of method performance for the two classes of glycopeptides. Here, we systematically explore the advantages and disadvantages of conventional HCD, sceHCD, ETD, and EThcD for intact glycopeptide analysis and determine their suitability for both N- and O-glycoproteomic applications. For N-glycopeptides, HCD and sceHCD generate similar numbers of identifications, although sceHCD generally provides higher quality spectra. Both significantly outperform EThcD methods, indicating that ETD-based methods are not required for routine N-glycoproteomics. Conversely, ETD-based methods, especially EThcD, are indispensable for site-specific analyses of O-glycopeptides. Our data show that O-glycopeptides cannot be robustly characterized with HCD-centric methods that are sufficient for N-glycopeptides, and glycoproteomic methods aiming to characterize O-glycopeptides must be constructed accordingly.</a></p>

scholarly journals Estimating landscape structure effects on pollination for management of agricultural landscapes

2021 ◽  
Author(s):  
Ehsan Rahimi ◽  
Shahindokht Barghjelveh ◽  
Pinliang Dong
Keyword(s):  
Landscape Composition ◽  
Agricultural Landscapes ◽  
Edge Density ◽  
Forest Patches ◽  
Habitat Amount ◽  
High Degree ◽  
Very High ◽  
Landscape Composition And Configuration ◽  
Degree Of Fragmentation ◽  
Significant Factors

Abstract The present study aims to examine the effects of habitat fragmentation to find a pattern of forest patches in agricultural landscapes that provide the highest pollination level. For this purpose, using simulated agricultural landscapes, including different forest proportions and degrees of fragmentation, pollination in different scenarios was estimated. We used landscape metrics to measure the landscape composition and configuration of each simulated landscape and estimated their statistical relationship with pollination. Our results showed that the effects of fragmentation on pollination were affected by two significant factors; 1- habitat amount and 2- small patches' capacity to supply pollination. Our results showed that when small patches' capacity in supplying pollination was low, fragmentation decreased pollination. When this capacity was very high, landscapes with a high degree of fragmentation showed higher levels of pollination. There was an exception for habitat amounts less than 0.1 of the entire landscape that increasing edge density, aggregation, and the number of patches, resulted in increasing pollination in all scenarios.

A Validated Chiral-RP-UPLC-MS/MS Method for the Enantiomeric Detection of Rivaroxaban In vitro

2019 ◽  
Vol 15 (4) ◽  
pp. 305-311 ◽  
Author(s):  
Fuxin Chen ◽  
Xiaoxian Ma ◽  
Chuangqian Chen ◽  
Kanshe Li ◽  
Suying Chen ◽  
...  
Keyword(s):  
Collision Energy ◽  
Limit Of Detection ◽  
Ion Pairs ◽  
Enantiomeric Separation ◽  
Rapid Onset ◽  
Cone Voltage ◽  
Onset Of Action ◽  
Column Temperature ◽  
Blood Samples

Background: Rivaroxaban is the first oral, selective direct FXa inhibitor with rapid onset of action and its biological toxicity may be related to the enantiomer. </P><P> Objective: The aim of the current study was to develop and validate a precise, accurate, and specific direct Chiral-RP-UPLC-MS/MS method for the enantiomeric separation and detection of rivaroxaban and its enantiomer. Methods: The present study screened various conditions of chromatographic and mass spectra, including chromatographic column model, flow velocity, phase ratio, column temperature, and collision energy, parent/daughter ion pairs, etc. Try to match the chromatographic and mass spectrometric conditions. Results: Good Rs (Rs>2.5) was achieved on a Chiralpak IC column (4.6 × 250 mm, 5µm) using H2O:acetonitrile (10:90) as mobile phase at 25 oC column temperature. The rate of flow was set at 0.4 ml/min and enantiomers were detected by triple-quadruple tandem mass spectrometry using positive electrospray ionization (ESI) with MRM transitions of m/z 436.07>144.95. The cone voltage and collision energy were kept at 48 V and 28 eV, respectively. The limit of detection and quantification of (S)- rivaroxaban were 0.39 and 1.30 ng/ml, respectively. This method was validated and found to be selective, precise, accurate, linear and robust for the quantitative determination of chiral impurities. It is also a good application for the blood samples analysis in vitro. Conclusion: Chiral-RP-UPLC-MS/MS method has entirely detected (S)-rivaroxaban and its (R)- enantiomer in very low concentration and complex matrix directly, especially for blood samples.

scholarly journals Boron Particles Production in Nonequilibrium Laser-Chemical Radical Reactions During the IR Multiphoton Dissociation of HCIC=CBCI2H Molecules

1989 ◽  
Vol 10 (2) ◽  
pp. 81-92 ◽  
Author(s):  
G. I. Abdushelishvili ◽  
T. G. Abzianidze ◽  
A. G. Bakhtadze ◽  
P. D. Kervalishvili ◽  
G. I. Tkeshelashvili ◽  
...  
Keyword(s):  
Experimental Results ◽  
Radical Reactions ◽  
Bimolecular Reactions ◽  
Elementary Boron ◽  
Multiphoton Dissociation ◽  
Boron Particles ◽  
High Degree ◽  
Degree Of Fragmentation

The study of IR MPD of HCIC=CBCI2H molecule by CO2.-laser is presented. We provide experimental results showing high degree of fragmentation of this molecule (down to elementary boron) during nonequilibrium laser induced radical bimolecular reactions.

Numerical Simulation of the Multiple Branch Transverse Response of a Low Mass Ratio Elastically Supported Circular Cylinder

2006 ◽  
Author(s):  
Richard H. J. Willden
Keyword(s):  
Circular Cylinder ◽  
Maximum Amplitude ◽  
Mass Ratio ◽  
Large Eddy Simulation Model ◽  
Eddy Simulation ◽  
Vortex Induced Vibrations ◽  
Low Mass ◽  
Low Mass Ratio ◽  
Elastically Supported ◽  
High Degree

The paper presents the results of a numerical investigation of the transverse Vortex-Induced Vibrations of an undamped, low mass ratio elastically supported circular cylinder that was subjected to a uniform flow that resulted in a Reynolds number of 104. The numerical simulations were performed using a two-dimensional Large Eddy Simulation model. The computed cylinder response exhibits three branches; the initial, upper and lower branches. The computed initial and lower branches, which exhibit 2S and 2P modes of shedding respectively, show many similarities to those reported from experiments. However, the computed upper branch, on which a maximum amplitude of response of 0.83D was achieved, shows some dissimilarities to those reported from experiments. The failure to correctly simulate the upper branch response is thought to be due to the high degree of flow three-dimensionality that has been reported to exist on the upper branch.

scholarly journals A study of the metabolism of l-αγ-diaminobutyric acid in a Xanthomonas species

1969 ◽  
Vol 114 (1) ◽  
pp. 107-115 ◽  
Author(s):  
D. Rajagopal Rao ◽  
K. Hariharan ◽  
K. R. Vijayalakshmi
Keyword(s):  
Substrate Specificity ◽  
Aspartic Acid ◽  
Acid Metabolism ◽  
Ph Optimum ◽  
Diaminobutyric Acid ◽  
Oxaloacetic Acid ◽  
Binding Agents ◽  
Xanthomonas Species ◽  
High Degree

1. l-αγ-Diaminobutyric acid is metabolized in Xanthomonas sp. to aspartic β-semialdehyde, aspartic acid and oxaloacetic acid. 2. Aspartic β-semialdehyde is formed from diaminobutyric acid by a pyruvate-dependent γ-transamination. 3. The transaminase has a pH optimum of 9 and exhibits a high degree of substrate specificity, as analogues of diaminobutyric acid and pyruvate are inert in the system. The transaminase is inhibited by carbonyl-binding agents such as hydroxylamine. 4. Aspartic acid is formed from aspartic β-semialdehyde by an NAD+-dependent dehydrogenation. 5. The dehydrogenase has a pH optimum of 8·5 and is a thiol enzyme. It is specific for aspartic β-semialdehyde but analogues of NAD+ such as 3-acetylpyridine–adenine dinucleotide and deamino-NAD are partly active in the system. 6. The significance of these reactions is discussed in relation to diaminobutyric acid metabolism in plants and mammalian systems.

scholarly journals Network position, export patterns and competitiveness: Evidence from the European automotive industry

2017 ◽  
Vol 21 (2) ◽  
pp. 132-158 ◽  
Author(s):  
Manuel Gracia ◽  
María J Paz
Keyword(s):  
European Union ◽  
Automotive Industry ◽  
Production Network ◽  
Regional Demand ◽  
Export Competitiveness ◽  
Automotive Production ◽  
Fragmentation Of Production ◽  
High Degree ◽  
European Regional ◽  
Degree Of Fragmentation

The organizational characteristics of production in the European automotive industry have favoured a high degree of fragmentation and productive mobility. This article analyses the differing national positions of automotive producing countries and their export patterns – particularly their export reorientation to extra-European Union markets following the collapse of regional demand in the European automotive industry. Based on the methodologies of Mahutga and Piana, our position analysis arrives at two main conclusions: (i) the countries best positioned in the European regional automotive production network are precisely those that have experienced a greater increase in extra-European Union exports, thus reducing their dependence on regional European demand; (ii) the increase in extra-European Union exports (mainly of final goods) is linked to increased regional fragmentation of production in the automotive industry. We conclude that the governance of this fragmentation process is a key determinant of extra-European Union export competitiveness.

Active Membrane Using Electrostructure Graft Elastomer for Deployable and Lightweight Mirrors

2007 ◽  
Author(s):  
E. H. Yang ◽  
Y. Hishinuma ◽  
J. Su ◽  
T. B. Xu ◽  
R. Morgan ◽  
...  
Keyword(s):  
Optical Quality ◽  
Space Telescopes ◽  
Current State ◽  
Layer Structures ◽  
Future Space ◽  
Low Mass ◽  
Resolution Imaging ◽  
Drive And Control ◽  
And Control ◽  
High Degree

An important requirement enabling future space missions is the availability of very large, deployed, re-configurable apertures for high-resolution imaging. Membrane-based architectures have the potential for very low aerial densities, which will enable large aperture space telescopes. Two major requirements for considering large apertures are: 1) a high degree of surface control coupled with a low-mass deployable capability and 2) an optical quality membrane mirror technology. Current state-of-the-art deployable aperture technologies have significant limitations in their ability to correct the surface figure following deployment. In this paper, a controlled deformation of silicon membrane mirrors using electroactive polymer has been demonstrated to overcome these limitations. We have designed, modeled, and fabricated Electrostrictive Graft Elastomer (G-elastomer)-based bi-layer membranes. The bi-layer mirror membranes maintain a good working condition after thermal cyclic tests, performed at temperatures between −50 °C and 150 °C. G-elastomer provides means to drive and control the deflection and curvature of reflective membranes. Several G-elastomer-based bi-layer structures have been optically characterized. This concept can be scaled to a deployable ultra-large mirror with a self-reconfiguration capability.

scholarly journals Dust distribution around low-mass planets on converging orbits

2020 ◽  
Vol 641 ◽  
pp. A125
Author(s):  
Francesco Marzari ◽  
Gennaro D’Angelo
Keyword(s):  
Outer Planet ◽  
Resonance Strength ◽  
Mean Motion Resonances ◽  
Tidal Interactions ◽  
Low Mass ◽  
Local Properties ◽  
Tidal Torques ◽  
Dust Distribution ◽  
High Degree ◽  
Dust Evolution

Context. Super-Earths can form at large orbital radii and migrate inward due to tidal interactions with the circumstellar disk. In this scenario, convergent migration may occur and lead to the formation of resonant pairs of planets. Aims. We explore the conditions under which convergent migration and resonance capture take place, and what dynamical consequences can be expected on the dust distribution surrounding the resonant pair. Methods. We combine hydrodynamic planet–disk interaction models with dust evolution calculations to investigate the signatures produced in the dust distribution by a pair of planets in mean-motion resonances. Results. We find that convergent migration takes place when the outer planet is the more massive. However, convergent migration also depends on the local properties of the disk, and divergent migration may result as well. For similar disk parameters, the capture in low degree resonances (e.g., 2:1 or 3:2) is preferred close to the star where the resonance strength can more easily overcome the tidal torques exerted by the gaseous disk. Farther away from the star, convergent migration may result in capture in high degree resonances. The dust distribution shows potentially observable features typically when the planets are trapped in a 2:1 resonance. In other cases, with higher degree resonances (e.g., 5:4 or 6:5) dust features may not be sufficiently pronounced to be easily observable. Conclusions. The degree of resonance established by a pair of super-Earths may be indicative of the location in the disk where capture occurred. There can be significant differences in the dust distribution around a single super-Earth and a pair of super-Earths in resonance.

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