scholarly journals Respiratory losses in the light in a marine diatom: Measurements by short-term mass spectrometry

1989 ◽  
Vol 34 (7) ◽  
pp. 1153-1161 ◽  
Author(s):  
Harold G. Weger ◽  
Ronny Herzig ◽  
Paul G. Falkowski ◽  
David H. Turpin
Keyword(s):  
Mass Spectrometry ◽  
Marine Diatom ◽  
Short Term

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Unsaturated Fatty Acid ◽  
Ion Trap ◽  
Carbon Chain ◽  
Highly Unsaturated Fatty Acid ◽  
Marine Diatom ◽  
Ion Trap Mass Spectrometry ◽  
Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

scholarly journals Evaluating Phthalate Contaminant Migration Using Thermal Desorption–Gas Chromatography–Mass Spectrometry (TD–GC–MS)

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 683 ◽  
Author(s):  
Yukihiro Ouchi ◽  
Hiroyuki Yanagisawa ◽  
Shigehiko Fujimaki
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Thermal Desorption ◽  
Gas Chromatography Mass Spectrometry ◽  
Approximation Model ◽  
Contaminant Migration ◽  
Short Term ◽  
Small Organic Molecules ◽  
Chromatography Mass Spectrometry ◽  
Ethylhexyl Phthalate

This study describes a methodology for evaluating regulatory levels of phthalate contamination. By collecting experimental data on short-term phthalate migration using thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS), the migration of di(2-ethylhexyl) phthalate (DEHP) from polyvinyl chloride (PVC) to polyethylene (PE) was found to be expressed by the Fickian approximation model, which was originally proposed for solid (PVC)/liquid (solvent) migration of phthalates. Consequently, good data correlation was obtained using the Fickian approximation model with a diffusion coefficient of 4.2 × 10−12 cm2/s for solid (PVC)/ solid (PE) migration of DEHP at 25 °C. Results showed that temporary contact with plasticized polymers under a normal, foreseeable condition may not pose an immediate risk of being contaminated by phthalates at regulatory levels. However, as phthalates are small organic molecules designed to be dispersed in a variety of polymers as plasticizers at a high compounding ratio, the risk of migration-related contamination can be high in comparison with other additives, especially under high temperatures. With these considerations in mind, the methodology for examining regulatory levels of phthalate contamination using TD–GC–MS has been successfully demonstrated from the viewpoint of its applicability to solid (PVC)/solid (PE) migration of phthalates.

scholarly journals Radiocarbon in 9th to 5th Century BC Tree-Ring Samples from the Ouban 1 Archaeological Site, Hiroshima, Japan

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 473-479 ◽  
Author(s):  
Hiromasa Ozaki ◽  
Mineo Imamura ◽  
Hiroyuki Matsuzaki ◽  
Takumi Mitsutani
Keyword(s):  
Mass Spectrometry ◽  
Tree Ring ◽  
Calibration Curve ◽  
Accelerator Mass Spectrometry ◽  
Wood Sample ◽  
Archaeological Site ◽  
Short Term ◽  
Statistical Errors ◽  
Term Fluctuation

In order to investigate the regional atmospheric radiocarbon offset, accelerator mass spectrometry (AMS) 14C measurements were made on 5-yr increments of a Japanese wood sample dendrochronologically dated to 820–436 BC. The 14C data from the Japanese tree-ring samples were compared with the IntCal04 calibration curve (Reimer et al. 2004). In most parts, the differences between IntCal04 and 14C dates in the Japanese tree-ring samples were within experimental statistical errors. At around 680 BC, however, significant differences of up to 100 14C yr were observed. These differences may indicate either regional offsets in Japan or the short-term fluctuation of a subdecadal timescale in atmospheric 14C variations.

Structural insights into calmodulin/Munc13 interaction

2014 ◽  
Vol 395 (7-8) ◽  
pp. 763-768 ◽  
Author(s):  
Sabine Herbst ◽  
Noa Lipstein ◽  
Olaf Jahn ◽  
Andrea Sinz
Keyword(s):  
Mass Spectrometry ◽  
Synaptic Plasticity ◽  
Binding Site ◽  
Cross Linking ◽  
Binding Motif ◽  
Binding Modes ◽  
Short Term ◽  
Common Domain ◽  
Structural Insights ◽  
Chemical Cross Linking

Abstract Munc13 proteins are essential presynaptic regulators that mediate synaptic vesicle priming and play a role in the regulation of neuronal short-term synaptic plasticity. All four Munc13 isoforms share a common domain structure, including a calmodulin (CaM) binding site in their otherwise divergent N-termini. Here, we summarize recent results on the investigation of the CaM/Munc13 interaction. By combining chemical cross-linking, photoaffinity labeling, and mass spectrometry, we showed that all neuronal Munc13 isoforms exhibit similar CaM binding modes. Moreover, we demonstrated that the 1-5-8-26 CaM binding motif discovered in Munc13-1 cannot be induced in the classical CaM target skMLCK, indicating unique features of the Munc13 CaM binding motif.

scholarly journals Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

2002 ◽  
Vol 2 ◽  
pp. 1579-1593 ◽  
Author(s):  
J.T. Jull ◽  
G.S. Burr ◽  
J.W. Beck ◽  
D.J. Donahue ◽  
D. Biddulph ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Radioactive Waste ◽  
Environmental Conditions ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Southern Oscillation ◽  
Waste Dump ◽  
Short Term ◽  
Millennial Time Scale ◽  
Climatic Record

There are many diverse uses of accelerator mass spectrometry (AMS).14C studies at our laboratory include much research related to paleoclimate, with14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation), or on the millennial time scale. In tracer applications, we have developed the use of129I as well as14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

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