Messenger ribonucleoprotein particles from plant cell cultures

Messenger ribonucleoprotein particles were isolated from the polysomes of logarithmically growing plant cell cultures, pulse-labeled with [3H] adenosine for 30 min. More than 80% of the labeled RNP was present in particles sedimenting between 80 S and 30 S on sucrose density gradients, but was not associated with ribosomal subunits. The size distribution differs from those reported for polysomal mRNP particles to date. After fixation with glutaraldehyde the labeled RNP particles had a buoyant density of 1.38 g/cm3 in CsCl gradients. Radioactively labeled RNA extracted from the RNP particles showed a heterodisperse size distribution and contained poly (A) stretches as determined by affinity chromatography and ribonuclease digestion experiments. © 1978, Walter de Gruyter. All rights reserved

Superconductivity in SrNi2As2 Single Crystals

The electrical resistivity \rho(T) and heat capacity C(T) on single crystals of SrNi2As2 and EuNi2As2 are reported. While there is no evidence for a structural transition in either compound, SrNi2As2 is found to be a bulk superconductor at T_c=0.62 K with a Sommerfeld coefficient of \gamma= 8.7 mJ/mol K^2 and a small upper critical field H_{c2} \sim 200 Oe. No superconductivity was found in EuNi2As2 above 0.4 K, but anomalies in \rho and C reveal that magnetic order associated with the Eu^{2+} magnetic moments occurs at T_m = 14 K.Comment: 8 pages, 5 figure

Strong coupling between Eu2+ spins and Fe2As2 layers in EuFe1.9Co0.1As2 observed with NMR

A combination of x-ray diffraction, magnetization, and 75As nuclear magnetic resonance (NMR) experiments were performed on single-crystal EuFe1.9Co0.1As2. The strength of the hyperfine interaction between the 75As nuclei and the Eu^(2+) 4f states suggests a strong coupling between the Eu^(2+) moments and the Fe1.9Co0.1As2 layers. Such a strong interlayer coupling may be due to an indirect exchange interaction between the localized Eu^(2+) 4f moments, mediated by the Fe 3d conduction electrons. Magnetic susceptibility as well as 75As-NMR measurements reveal a decrease of the SDW transition temperature to T_SDW = 120 K as a result of Co doping. A change of the slope in the temperature dependence of the NMR frequency of the 75As lower-satellite line was observed at 225 K. At the same temperature also a change of the satellite line shape was found. These changes of the NMR spectra may be caused by the formation of a nematic phase below 225 K in EuFe1.9Co0.1As2.Comment: 8 pages, 7 figure

Intuitive Data-Driven Visualization of Food Relatedness via t-Distributed Stochastic Neighbor Embedding

The relationship between diet and health is important, yet difficultto study in practice. Dietary pattern analysis is one method forinvestigating this link; having more variety in diet tends to be bene-ficial and a score can be generated based on a heuristic approachto food intake habits. We aim to enhance the intuition behindthese food scores by creating an intuitive data-driven visualizationof food relatedness by leveraging t-distributed stochastic neighborembedding (t-SNE). More specifically, by performing t-SNE anal-ysis in a controlled manner to project the high-dimensional nutri-tional information of food items into a lower dimensional food sim-ilarity space, the natural clustering of foods based on the underly-ing nutritional composition becomes visually observable. The effi-cacy of this data-driven approach for visualizing food relatednesswas investigated on a total of 8549 food item entries in the USDAfood composition database, with the results showing considerablepromise as a tool for gaining important nutritional insights. This isthe first step toward providing a novel method to enhance dietarypattern analysis with additional context and insight into food intakehabits based on the inherent nutritional content of the foods con-sumed

Ambulatory scintigraphic assessment of transient changes in left ventricular function: a new method for detection of silent myocardial ischaemia

Demonstration of ischaemic left ventricular dysfunction in the absence of chest pain should provide important confirmation of silent myocardial ischaemia in patients with asymptomatic ST segment changes. For this purpose, a new portable scintillation probe (VEST) similar to a miniaturized nuclear stethoscope combined with a Hotter ECG was evaluated. After standard equilibrium radionuclide angiocardiography with technetium-99m labelled red blood cells, the VEST was positioned under gamma-camera control and data were recorded from 1-12 h in 61 unselected patients. Ejection fraction (LVEF), relative changes in volumes, heart rate and ST segment changes were determined. Reproducibility of LVEF at rest (r = 0.91; variability 3.8 ± 3%, N = 19) and during exercise (r = 0.98; variability 3.2 ± 2%, N = 19) was good. In 15 asymptomatic exercise tests four different patterns of LVEF and ST segment responses were identified: (1) decrease in LVEF followed by significant ST depression (five times); (2) ST depression followed by decrease in LVEF (three times); (3) decrease in LVEF without significant ST changes (three times); and (4) ST depression without significant LVEF change (four times). In this still small series, patterns (1) to (3) corresponded to patients with documented coronary artery disease, which was not the case for pattern (4). For detection of silent ischaemia at rest, a decrease in LVEF of >5% lasting for >1 min was defined as ischaemic LV dysfunction. Using this definition, four spontaneous episodes of silent LV dysfunction could be demonstrated in two of three CCU patients with unstable angina during 160-680 min of data recordings without simultaneous ST changes. Based on this initial experience, we conclude that VEST is a reproducible method to detect transient global LV dysfunction and will be useful to confirm silent ischaemia in otherwise uncertain ST segment change