Advanced searches left 3/3

Carbon-13 - DOAJ

Summarized by Plex Scholar
Last Updated: 10 January 2023

* If you want to update the article please login/register

Implementation and initial calibration of carbon-13 soil organic matter decomposition in the Yasso model

Soils account for the largest amount of carbon found in terrestrial ecosystems, and their presence is of particular concern for global carbon cycle preservation and atmospheric carbon concentration. Investigating soil organic matter concentrations gives one of the best ways to investigate carbon decomposition processes. We introduce a carbon-13-isotope-specific soil organic matter decomposition add-on to the Yasso soil carbon model and evaluate its functionality in this essay. The new 13 C-dedicated decomposition is simple to implement and reduces linearly on the default Yasso model parameters and the relative carbon isotope concentration. In a 100-year-long simulation, modelled u03b4 13 is compared to fractionated peat column carbon content, where modelled u03b4 13 is significantly improved the model behavior. The work presented here is a demonstration of concept and enables 13 C to be used as a natural tracer to detect changes in the underlying soil organic matter decomposition.

Source link: https://doi.org/10.5194/bg-19-4305-2022


Diagnosis of by carbon-13 urea breath test using a portable mass spectrometer

Helicobacter pylori has been implicated in the onset of chronic gastritis, gastric, and duodenal ulcers, as well as gastric cancer. Objects: To compare the findings obtained from a H. pylori experiment using a portable quadrupole mass spectrometer with those obtained from a fixed mass spectrometer in a hospital-based clinical trial. Methods: 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag, according to a protocol defined by ethics. If the post-drink level was above the pre-drink threshold by 3% or more, there was a good indication of H. pylori. The portable quadrupole mass spectrometer's development could reduce further its size and cost, according to more research to confirm this new technology and to expand its use in mass spectrometry diagnosis of other medical conditions.

Source link: https://doi.org/10.1177/2050312115569565


Studies on carbon-13 turnover in eggs and blood of commercial layers

This paper was designed to investigate the effect of diets containing different isotopic values of carbon-13 turnover on egg, yolk and albumen's half-life individually and blood of poultry using delta > 203013C isotopic variation. Both blood and albumen were more affected by dietary habits than egg and yolk.

Source link: https://doi.org/10.1590/S1516-635X2006000400008


Description of a global marine particulate organic carbon-13 isotope data set

Understanding carbon cycling in the atmosphere, ocean, and biosphere can be aided by marine particulate organic carbon stable isotope ratios. To produce the most complete marine u03b4 13 C POC data set, we assembled all such available data sets and merged and homogenized them. The dataset consists of 4732 data points spanning all major ocean basins that have existed since the 1960s. An analysis of 1990s median u03b4 13 C POC values in a meridional section across the best-covered Atlantic Ocean shows relatively high values in the low latitudes trending toward lower values in the Arctic Ocean and Southern Ocean. The median u03b4 13 C POC decline in all basins except for the Southern Ocean, which shows a decrease in the median trend since the 1960s but has relatively poor multi-decadal coverage.

Source link: https://doi.org/10.5194/essd-13-4861-2021


Determination of Lignin-Carbohydrate Complexes Structure of Wheat Straw using Carbon-13 Isotope as a Tracer

The conversion of lignin-carbohydrate complexes was defined by injection of 13C isotope-labeled xylose into living wheat straw, allowing for maximum usage of wheat straw as a feedstock for biofuels and other biorefinery products. The Bju00f6rkman method extracted lignin-carbohydrate complexes from the harvested straw lignin-carbohydrate complexes later. LCCs in wheat straw were particularly rich in xylan and showed little polydispersity, according to the study. The lignin in the LCCs of wheat straw contained aiacyl, syringyl, and p-hydroxyphenyl units in the proportion of 5:4:1. In 13C-LCC, the number of bonded linksages was 210. 86/100C9, dominated by phenyl glycoside linkages, followed by u03b3-ester bonds and small amounts of benzyl ether bonds, with phenyl glycoside linkages. The LCCs of wheat straw were mainly linked by benzyl ether bonds and phenyl glycoside linkages, with benzyl ether bonds and phenyl glycoside linkages principally linking Lignin and xylan.

Source link: https://doi.org/10.15376/biores.11.3.6692-6707


Simultaneous quantitative determination of deuterium- and carbon-13-labeled essential fatty acids in rat plasma

In rat plasma samples at 24 h after dosing, there were no significant differences between the 2H versus 13C isotopomers of 18:2n-6, 18:3n-3, arachidonic acid, and docosahexaenoic acid, according to Thu, but there were no significant differences between the two groups of the 2H versus 13C isotopomers of 18:2n-6, 18:3n-3, arachid.

Source link: https://doi.org/10.1194/jlr.M500128-JLR200


Synthesis of carbon-13-labeled tetradecanoic acids.

The synthesis of tetradecanoic acid enriched with 13C at carbons 1,3, or 6 is described. [3-13C]tetradecanoic acid was synthesized by alkylation of diethyl sodio-malonate with [1-13C]1-bromodecane; the acid was obtained after saponification and decarboxylation. The label at the 6 position was introduced by coupling the appropriately labeled alkylcadmium chloride with the half acid chloride methyl ester of the appropriate dioic acid, supplying the appropriate oxo fatty acid ester. The oxo-ester's tosylhydrazone's tosylhydrazone was formed by the oxo-ester's tosylhydrazone's formation was followed by reduction with sodium cyanoborohydride, resulting in the desired tetradecanoic acid on hydrolysis.

Source link: https://doi.org/10.1016/S0022-2275(20)37940-2


Taxonomy-Focused Natural Product Databases for Carbon-13 NMR-Based Dereplication

A series of freely available python scripts, CNMR_Predict, is recommended for the quick enhancement of taxon oriented search results from the naturaL prOducts database with predicted carbon-13 nuclear magnetic resonance results from the ACD/Labs CNMR predictor and DB software to create fast searchable databases. Using Brassica rapa as a taxon example, the database building process can be shown.

Source link: https://doi.org/10.3390/analytica2030006


Quantitative analysis of the main components of the wines by means of carbon-13 NMR : optimisation of the method

Despite the low sensitivity and aboundance of the carbon 13 nuclei, 13C NMR spectroscopy was demonstrated to be an effective quantitative analytic device for the main ingredients of the wines. Excellent linear correlations were established between the integral of the resonance signals and the concentrations of the corresponding components of the corresponding components when the acquisition parameters of the 13C NMR spectra modified by means of the simplexe method.

Source link: https://doi.org/10.20870/oeno-one.1996.30.2.1107


Inhibitors of sterol biosynthesis. Carbon-13 nuclear magnetic resonance studies of 9 alpha-fluoro-5 alpha-cholest-8(14)-en-3 beta-ol-15-one and related compounds.

3 alpha-cholest alpha-cholests-8-one, 9 alpha-cholest alpha-cholest-8-en-3 beta-one, 3 beta-acetoxy-5 alpha-cholest 8-en-3 beta-one, 3 beta-hydroxy-5 alpha-cholest-8-en-3 beta-one, 3 alpha-cholest-8-en-3 beta-one, 3 beta-acetoxy-5 alpha-cholest alpha-cholest-8-en-3 alpha-en-3 alpha-cholest alpha-en-3 alpha-l-ene-cholest alpha-cholest-alpha-cholest alpha-en-3.

Source link: https://doi.org/10.1016/S0022-2275(20)37311-9

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions