Sterol composition of caper (Capparis spinosa) seeds

Caper is a perennial shrub of the Mediterranean Basin. The most important economical species is Capparis spinosa. Sterols of C. spinosa seed oil isolated from seven Tunisian stands were identified andquantified. C. spinosa contained  high levels of phytosterols (2240.4 mg/kg of total extracted lipids), of which -sitosterol, with 1390 mg/kg, was the most abundant (57.53%). Campesterol and stigmasterol accounted for 382 and 265 mg/kg, respectively (17.05 and 11.85% of the total sterols, respectively). C. spinosa seed oil also contained a high level of 5-avenasterol (6%). We detect also brassicasterol (3.39 mg/kg). Cholesterol and campestanol are detected in much lower levels. These results bring attention to the richness of C.spinosa seed oil with sterols which are the most important class of the minor components

A Disposable paper breathalyzer with an alcohol sensing organic electrochemical transistor.

UNLABELLED: Breathalyzers estimate Blood Alcohol Content (BAC) from the concentration of ethanol in the breath. Breathalyzers are easy to use but are limited either by their high price and by environmental concerns, or by a short lifetime and the need for continuous recalibration. Here, we demonstrate a proof-of-concept disposable breathalyzer using an organic electrochemical transistor (OECT) modified with alcohol dehydrogenase (ADH) as the sensor. The OECT is made with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PEDOT: PSS), and is printed on paper. ADH and its cofactor nicotinamide adenine dinucleotide (NAD(+)) are immobilized onto the OECT with an electrolyte gel. When the OECT-breathalyzer is exposed to ethanol vapor, the enzymatic reaction of ADH and ethanol transforms NAD(+) into NADH, which causes a decrease in the OECT source drain current. In this fashion, the OECT-breathalyzer easily detects ethanol in the breath equivalent to BAC from 0.01% to 0.2%. The use of a printed OECT may contribute to the development of breathalyzers that are disposable, ecofriendly, and integrated with wearable devices for real-time BAC monitoring

Observation of slow order parameter fluctuations in superconducting films using beta-detected NMR

We report beta-NMR investigations of polarized 8Li implanted in thin Pb and Ag/Nb films. At the critical superconducting temperature, we observe a singular peak in the spin relaxation rate in small longitudinal magnetic fields, which is attributed to fluctuations in the superconducting order parameter. However, the peak is more than an order of magnitude larger than the prediction based on the enhancement of the dynamic electron spin susceptibility by superconducting fluctuations and reflects the presence of unexpected slow fluctuations. Furthermore the fluctuations are rapidly suppressed in a small magnetic field, which may explain why they have not been observed previously with conventional NMR or NQR.Comment: 5 pages, 2 figure

Vortex lattice disorder in YBCO probed using Beta-NMR

Beta-NMR has been used to study vortex lattice disorder near the surface of the high-Tc superconductor YBCO. The magnetic field distribution from the vortex lattice was detected by implanting a low energy beam of highly polarized 8Li into a thin overlayer of silver on optimally doped, twinned and detwinned YBCO samples. The resonance in Ag broadens significantly below the transition temperature Tc as expected from the emerging field lines of the vortex lattice in YBCO. However, the lineshape is more symmetric and the dependence on the applied magnetic field is much weaker than expected from an ideal vortex lattice, indicating that the vortex density varies across the face of the sample, likely due to pinning at twin boundaries. At low temperatures the broadening from such disorder does not scale with the superfluid density.Comment: 10 pages, 6 figure