Here, we describe the design and performance characteristics of a low temperature probe for dynamic nuclear polarization (DNP) experiments, which is compatible with demanding multiple-pulse experiments. The competing goals of a high-Q microwave cavity to achieve large DNP enhancements and a high efficiency NMR circuit for multiple-pulse control lead to inevitable engineering tradeoffs. We have designed two probes-one with a single-resonance RF circuit and a horn-mirror cavity configuration for the microwaves and a second with a double-resonance RF circuit and a double-horn cavity configuration. The advantage of the design is that the sample is in vacuum, the RF circuits are locally tuned, and the microwave resonator has a large internal volume that is compatible with the use of RF and gradient coils.
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http://dx.doi.org/10.1016/j.jmr.2007.04.012 | DOI Listing |
Risk Manag Healthc Policy
January 2025
Department of Cardiology, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, People's Republic of China.
Purpose: The effect of the diurnal temperature range (DTR) on human health in diverse geographic areas and the potential confounding factors are not fully understood. Additionally, while a robust association has been reported between temperature and cardiomyopathy (CM), evidence of the impact of DTR is relatively limited. Here, we determined whether an association exists between DTR and CM hospitalisations in vulnerable populations.
View Article and Find Full Text PDFJ Food Sci Technol
January 2025
Department of Food Engineering and Technology, School of Food Engineering, Universidade Estadual de Campinas (UNICAMP), Monteiro Lobato 80, 6121, Campinas, SP 3083-862 Brazil.
Unlabelled: The effects of high hydrostatic pressure (HHP) (400-650 MPa) and holding temperature (25-50 °C) in thermally assisted HHP processing on multi-scale structure of starch (granule, crystalline and molecular), techno-functional properties, and digestibility of sorghum starch (SS) were evaluated. Response surface methodology has verified that the process impact on the modification of SS was dependent primarily on the pressure level. As HHP increased, processed SS progressively lost their granular structure and Maltese cross, indicating gradual structural disorder within the granules.
View Article and Find Full Text PDFInd Eng Chem Res
January 2025
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
This work presents the scale-up of room-temperature mechanochemical synthesis of nanocorundum (high-surface-area α-AlO) from boehmite (γ-AlOOH). This transformation on the 1 g scale using a laboratory shaker mill had previously been reported. High-energy Simoloyer ball mills equipped with milling chambers of sizes ranging from 1 to 20 L were used to scale up the mechanochemical nanocorundum synthesis to the 50 g to 1 kg scale, which paves the way to further increase batch size.
View Article and Find Full Text PDFRSC Adv
January 2025
College of Material Science and Art Design, Inner Mongolia Agricultural University Hohhot 010018 China
Corn stover was used as raw material, and purification, oxalic acid treatment, oxidation treatment, and ultrasonic treatment were performed to realize the preparation of corn stover nanocellulose with low energy consumption. The effects of oxalic acid concentration (1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt%) on the purity, morphology, crystalline structure and oxidation efficiency of corn stover cellulose during oxalic acid treatment were investigated. The controllable preparation of corn stover nanocellulose was achieved by changing the parameter conditions of ultrasonic treatment.
View Article and Find Full Text PDFFront Physiol
January 2025
Susan Samueli Integrative Health Institute and Department of Medicine, University of California, Irvine, Irvine, CA, United States.
Stellate ganglion blockade (SGB) is a practical approach to managing many clinical disorders. Ultrasound-guided SGB is currently adopted as a more effective and safer method in humans. Developing this technique in rats would facilitate further study of SGB application.
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