Rationale: Traditionally, stable isotope analysis of plant and soil water has been a technically challenging, labour-intensive and time-consuming process. Here we describe a rapid single-step technique which combines Microwave Extraction with Isotope Ratio Infrared Spectroscopy (ME-IRIS).
Methods: Plant, soil and insect water is extracted into a dry air stream by microwave irradiation within a sealed vessel. The water vapor thus produced is carried to a cooled condensation chamber, which controls the water vapor concentration and flow rate to the spectrometer. Integration of the isotope signals over the whole analytical cycle provides quantitative δ(18)O and δ(2) H values for the initial liquid water contained in the sample. Calibration is carried out by the analysis of water standards using the same apparatus. Analysis of leaf and soil water by cryogenic vacuum distillation and IRMS was used to validate the ME-IRIS data.
Results: Comparison with data obtained by cryogenic distillation and IRMS shows that the new technique provides accurate water isotope data for leaves from a range of field-grown tropical plant species. However, two exotic nursery plants were found to suffer from spectral interferences from co-extracted organic compounds. The precision for extracted leaf, stem, soil and insect water was typically better than ±0.3 ‰ for δ(18)O and ±2 ‰ for δ(2) H values, and better than ±0.1 ‰ for δ(18)O and ±1 ‰ for δ(2) H values when analyzing water standards. The effects of sample size, microwave power and duration and sample-to-sample memory on isotope values were assessed.
Conclusions: ME-IRIS provides rapid and low-cost extraction and analysis of δ(18)O and δ(2) H values in plant, soil and insect water (≈10-15 min for samples yielding ≈ 0.3 mL of water). The technique can accommodate whole leaves of many plant species.
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http://dx.doi.org/10.1002/rcm.7005 | DOI Listing |
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December 2024
Department of Physics, Incheon National University, Incheon, 22012, South Korea.
The concept of non-trivial electronic structure combined with reduced dimensionality presents a promising strategy for advancing optical applications and energy harvesting technologies. Symmetry breaking in low dimensional system enables the emergence of non-linear optical responses, which are greatly amplified by the singular points of band inversion. Here, using first-principles calculations, the significant enhancement of the shift current in Bi nanotubes is investigated, driven by the combined effects of 1D geometry and non-trivial band order.
View Article and Find Full Text PDFVet Anim Sci
September 2024
Food Science Division: Microbial Biochemical and Food Biotechnology, Faculty of Natural and Agricultural Sciences, PO Box 339, Bloemfontein, 9300, South Africa.
The effects of A (African wormwood) essential oil incorporation in diets on meat quality and fatty acid profilers of broilers was assessed. Four hundred Cobb500 day-old chicks were obtained and placed randomly into the following 4 diets replicated 10 times: NC-Negative control (broiler diet without antibiotics), PC-positive control (broiler diet with zinc bacitracin), AA1-broiler diet + 0.1 % essential oil and AA2 - broiler diet + 0.
View Article and Find Full Text PDFAdv Mater
October 2024
State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
Dipole moment arrangement in organic semiconductors plays a critical role in affecting the intermolecular packing, determining optoelectronic properties and device performance. Here, to get the desired fill factor (FF) values in organic solar cells (OSCs), the local dipole of non-fullerene acceptors (NFAs) is modulated by changing the molecular asymmetries. Two NFAs, AA-1 and AA-2 are designed and synthesized, which have different substitutions of alkyl and alkoxyl groups.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
The objective of this investigation is to learn more about the structural, electrical, spectroscopic, and physiochemical characteristics of biologically active cyano-4'-hydroxybiphenyl (CHBP). The title molecule's optimized conformational analysis was computed using the DFT/B3LYP/6-311++G (d, p) level of theory. The observed wavenumbers were compared with theoretical FT-IR and FT-Raman spectra.
View Article and Find Full Text PDFBackground: Alopecia areata (AA) is a debilitating autoimmune disease that results in non-scarring hair loss. Baricitinib is the Food and Drug Administration (FDA) approved treatment for AA. Objective: Review the mechanism of action, pharmacokinetics, pharmacodynamics, efficacy, and safety of baricitinib in the treatment of AA.
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