Results 41 to 50 of about 163,020 (214)

Manganese–pyridone-catalyzed site-selective hydrogen isotope exchange of 2-arylpyridines using D2O [PDF]

RSC Advances
We report a manganese-catalyzed protocol for the selective ortho-deuteration of 2-arylpyridines using D2O as a readily available deuterium source. Enabled by Mn(CO)5Br and 2-pyridone, the reaction delivers deuterated products in good isolated yields with
Jian-Fei Bai, Tao Qian, Yunlong Yao, Zhi-Jiang Jiang, Jia Chen, Zhanghua Gao   +5 more
doaj   +1 more source

Nitrogen-Induced Changes in Soil Environmental Factors Are More Important Than Nitrification and Denitrification Gene Abundance in Regulating N2O Emissions in Subtropical Forest Soils

Frontiers in Plant Science, 2022
Subtropical regions are currently experiencing a dramatic increase in nitrogen (N) deposition; however, the contributions of nitrification and denitrification processes to soil N2O emissions and the underlying mechanisms under increasing N deposition ...
Qingyan Qiu, Abubakari Said Mgelwa, Shaofei Jin, Yalin Hu   +3 more
doaj   +1 more source

Determining trophic niche width: a novel approach using stable isotope analysis [PDF]

, 2004
1. Although conceptually robust, it has proven difficult to find practical measures of niche width that are simple to obtain, yet provide an adequate descriptor of the ecological position of the population examined. 2.
Bearhop, S., Bearhop, Stuart, Fuller, R.A., Waldron, S., Adams, C.E., Macleod, H.   +5 more
core   +1 more source

Content, composition, and transfer of polyunsaturated fatty acids in an Arctic lake food web

Ecosphere, 2022
Freshwater fish production depends on the production and use of polyunsaturated fatty acids (n‐3 and n‐6 PUFA) from lower trophic levels. Here, we aimed to identify the main trophic pathways that support PUFA content in different fish species (mean 39.7 ...
Guillaume Grosbois, Michael Power, Marlene Evans, Geoff Koehler, Milla Rautio   +4 more
doaj   +1 more source

Recent freshening in the Kara sea (Siberia) recorded by stable isotopes in Arctic bivalve shells, [PDF]

, 2005
Oxygen and stable carbon isotope records along the growth direction on shells of the bivalve species Astarte borealis and Serripes groenlandicus reliably record all important aspects of the bottom water hydrography in the shallow southeastern Kara Sea ...
Simstich, Johannes, Erlenkeuser, H., Bauch, Dorothea, Karcher, Michael, Spielhagen, Robert F., Spielhagen, R. F., Kodina, L., Karcher, M. J., Spielhagen, Robert, Simstich, J., Bauch, D., Stanovoy, V., Harms, I., Karcher, M.   +13 more
core   +1 more source

Computational Mass Transfer Study of Special High-efficiency Packing Used in the Separation of Carbon-13

Journal of Isotopes, 2020
The separation of stable isotope carbon-13（13C） is very difficult because the separation coefficient is only 1.007. So it is necessary that nearly three thousand theoretical stages should be required to obtain a high abundance product of 99 atom% 13C. In
TIAN Yesheng;LI Hulin
doaj   +1 more source

Stable isotopic labeling in proteomics [PDF]

PROTEOMICS, 2008
AbstractLabeling of proteins and peptides with stable heavy isotopes (deuterium, carbon‐13, nitrogen‐15, and oxygen‐18) is widely used in quantitative proteomics. These are either incorporated metabolically in cells and small organisms, or postmetabolically in proteins and peptides by chemical or enzymatic reactions.
Gevaert, Kris, Impens, Francis, Ghesquière, Bart, Van Damme, Petra, Lambrechts, Anja, Vandekerckhove, Joël   +5 more
openaire   +3 more sources

Is the Mesolithic-Neolithic Subsistence Dichotomy Real? New Stable Isotope Evidence from the Danube Gorges [PDF]

, 2004
The article presents new results of stable isotope analyses made on animal and human bones from the Mesolithic-early Neolithic sites of Lepenski Vir and Vlasac in the Danube Gorges of the Balkans.
Borić, Dušan, Mikić, Živko, Mikić, Z., Grupe, Gisela, Grupe, G., Peters, Joris, Peters, J.   +6 more
core   +1 more source

Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest

iForest - Biogeosciences and Forestry, 2009
Due to climate change, drier summers have been observed over the last ten years in Mediterranean areas. Increasing drought levels may have a different weight in influencing the stomatal versus photosynthetic activity of forests, altering the water-use ...
Ripullone F, Guerrieri MR, Saurer M, Siegwolf R, Jäggi M, Guarini R, Magnani F   +6 more
doaj   +1 more source

Syntheses of Stable Isotope ［13C］/D Labelled p-Methoxybenzoic Acid

Journal of Isotopes, 2020
Stable isotope labelled p-methoxybenzoic acid is an important intermediate in the synthesis of stable isotope labelled preservative, anti-microbial, anti-fungal, spices, and other internal standard reagentsspices, drugs and other compounds.
WANG Wei;DU Xiaoning;XU Jianfei;LEI Wen
doaj   +1 more source