Radiocarbon dating was performed for the extracted organic fractions (cellulose-rich and humic acid fractions of plant fragment; fulvic acid, humic acid and humin fractions of humus substance) and shell from core sediments of the Erhai Lake, SW China. The 14C dating results reveal that there are considerable differences, but there apparently is a humic acid ≤ humin < fulvic acid fraction sequen...

The effect of vitamin A supplements on metabolic behavior of an oral tracer dose of [14C]beta-carotene was investigated in a longitudinal test-retest design in two adults. For the test, each subject ingested 1 nmol of [14C]beta-carotene (100 nCi) in an emulsified olive oil-banana drink. Total urine and stool were collected for up to 30 days; concentration-time patterns of [14C]beta-carotene, [1...

A microsomal enzyme system from rat liver was shown to catalyze desaturation, in presence of reduced pyridine nucleotides and oxygen, of 1-acyl-2-[14C]eicosatrienoyl-sn-glycero-3-phosphorylcholine to 1-acyl-2-[14C]arachidonoyl-sn-glycerophosphorylcholine. This desaturation was linear with time and proportional to microsomal protein concentration, and proceeded with no significant breakdown of t...

Intact cells of the alga Amphidinium carterae (Dinophyceae), and a cell-free system prepared from it, incorporated 14C, 3H-labelled mevalonate into lycopene, beta, beta-carotene, zeaxanthin, neoxanthin, diadinoxanthin and peridinin. The 14C/3H ratios of zeaxanthin, neoxanthin and diadinoxanthin formed from (2RS,3R)-[2-14C,2-3H2]mevalonate show that a hydrogen atom from C-2 of mevalonate is reta...

Nonylphenol (NP) and other hydrophobic biodegradation intermediates of nonylphenol ethoxylate (NPE) surfactants have been identified in wastewater treatment biosolids. These biosolids often are land applied, but little is known regarding the potential uptake of biosolid-derived contaminants by plants. Hydroponic experiments, 11 to 14 weeks in duration, were conducted to examine the uptake and t...

Radiocarbon content in tree rings can be an excellent proxy of the past incoming cosmic ray intensities to Earth. Although such past cosmic ray variations have been studied by measurements of 14C contents in tree rings with ≥10-y time resolution for the Holocene, there are few annual 14C data. There is a little understanding about annual 14C variations in the past, with the exception of a few p...

Addition of platelet-activating factor (PAF) to cells doubly labeled with [14C]glycerol plus [3H]arachidonic acid resulted in a transient decrease of [14C]glycerol-labeled phosphatidylinositol (PI) and a transient increase of [14C]glycerol-labeled lysophosphatidylinositol (LPI). [3H]Arachidonate-labeled PI, on the other hand, decreased in a time-dependent manner. The radioactivity in phosphatid...

BACKGROUND We previously showed the practical and ethical feasibility of using [14C]-microdosing for pharmacokinetic studies in children. We now aimed to show that this approach can be used to elucidate developmental changes in drug metabolism, more specifically, glucuronidation and sulfation, using [14C]paracetamol (AAP). METHODS Infants admitted to the intensive care unit received a single ...

We examined whether cardiolipin (CL) synthesis was required to support cholesterol (CH) production from palmitate in Hela cells. Knockdown of human cardiolipin synthase-1 (hCLS1) in Hela cells has been shown to reduce CL synthesis. Therefore Hela cells stably expressing shRNA for hCLS1 and mock control cells were incubated for 16 h with [14C(U)]palmitate bound to albumin (1:1 molar ratio) in th...

The chronology of multiple landslide deposits and related lake sediments in the semi-arid eastern Argentine Cordillera suggests that major mass movements cluster in two time periods during the Quaternary, i.e. between 40 and 25 and after 5 14C kyr BP. These clusters may correspond to the Minchin (maximum at around 28^27 14C kyr BP) and Titicaca wet periods (after 3.9 14C kyr BP). The more humid...