A Catalog of Interplanetary Coronal Mass Ejections Observed by Juno between 1 and 5.4 au

We use magnetic field measurements by the Juno spacecraft to catalog and investigate interplanetary coronal mass ejections (ICMEs) beyond 1 au. During its cruise phase, Juno spent about 5 yr in the solar wind between 2011 September and 2016 June, providing measurements of the interplanetary magnetic field (IMF) between 1 and 5.4 au. Juno therefore presents the most recent opportunity for a statistical analysis of ICME properties beyond 1 au since the Ulysses mission (1990–2009). Our catalog includes 80 such ICME events, 32 of which contain associated flux-rope-like structures. We find that the dependency of the mean magnetic field strength of the magnetic flux ropes decreases with heliocentric distance as r −1.24±0.43 between 1 and 5.4 au, in good agreement with previous relationships calculated using ICME catalogs at Ulysses. We combine the Juno catalog with the HELCATS catalog to create a data set of ICMEs covering 0.3–5.4 au. Using a linear regression model to fit the combined data set on a double-logarithmic plot, we find that there is a clear difference between global expansion rates for ICMEs observed at shorter heliocentric distances and those observed farther out beyond 1 au. The cataloged ICMEs at Juno present a good basis for future multispacecraft studies of ICME evolution between the inner heliosphere, 1 au, and beyond.

Analysis of Preterm Pregnancies using Empirical Mode Decomposition based Fractal Features

Preterm birth (gestational age < 37 weeks) is a serious pregnancy related complication that could lead to fetal morbidity and mortality. Monitoring the activity of uterus is considered to be crucial for the early diagnosis of preterm birth. Uterine Electromyography (uEMG) is a non-invasive technique that provides a quantitative measure of uterine activity from the abdominal surface. In this work, an attempt has been made to characterize preterm uEMG signals using Empirical Mode Decomposition based Detrended Fluctuation Analysis (EMD-DFA). Preterm signals with varied gestational ages are considered from an online database. EMD-DFA is applied on these signals to compute the fluctuation function. The double-logarithmic plot of fluctuation function versus scale is evaluated and Chi-square analysis is performed for identifying linear scaling regions. Five features namely shortterm exponent (Hs), long-term exponent (Hl), inflection point, short-term fractal angle (αHs) and long-term fractal angle (αHl) are extracted and analyzed. Further, Coefficient of Variation (CV) is computed to examine the variations of these features among different subjects. Results show that EMD-DFA is able to characterize the fluctuations of preterm signals. From the double-logarithmic plot, a slow variation of fluctuation function is observed with respect to scale when the time to delivery is more. This indicates the presence of rapid signal fluctuations in the early stages of pregnancy. Based on the feature values, it is observed that the signal fluctuations are more correlated and smoother as the time to delivery approaches. Among the extracted features, CV values of Hs, Hl, αHs and αHl are observed to be low indicating that these features have least inter-subject variations in preterm signals. The EMD-DFA based fractal features show the ability to detect the subtle variations in uEMG signals. As early diagnosis of preterm delivery is imperative for timely medical intervention and treatment, it appears that the proposed approach could aid in determining the changes in uterine contractions in preterm condition.

Investigations on the Interactions of 5-Fluorouracil with Herring Sperm DNA: Steady State/Time Resolved and Molecular Modeling Studies

In the present study, the interaction of 5-Fluorouracil with herring sperm DNA is reported using spectroscopic and molecular modeling techniques. This binding study of 5-FU with hs-DNA is of paramount importance in understanding chemico–biological interactions for drug design, pharmacy and biochemistry without altering the original structure. The challenge of the study was to find the exact binding mode of the drug 5-Fluorouracil with hs-DNA. From the absorption studies, a hyperchromic effect was observed for the herring sperm DNA in the presence of 5-Fluorouracil and a binding constant of 6.153 × 103 M-1 for 5-Fluorouracil reveals the existence of weak interaction between the 5-Fluorouracil and herring sperm DNA. Ethidium bromide loaded herring sperm DNA showed a quenching in the fluorescence intensity after the addition of 5-Fluorouracil. The binding constants for 5-Fluorouracil stranded DNA and competitive bindings of 5-FU interacting with DNA–EB systems were examined by fluorescence spectra. The Stern–Volmer plots and fluorescence lifetime results confirm the static quenching nature of the drug-DNA complex. The binding constant Kb was 2.5 × 104 L mol-1 and the number of binding sites are 1.17. The 5-FU on DNA system was calculated using double logarithmic plot. From the Forster nonradiative energy transfer study it has been found that the distance of 5-FU from DNA was 4.24 nm. In addition to the spectroscopic results, the molecular modeling studies also revealed the major groove binding as well as the partial intercalation mode of binding between the 5-Fluorouracil and herring sperm DNA. The binding energy and major groove binding as -6.04 kcal mol-1 and -6.31 kcal mol-1 were calculated from the modeling studies. All the testimonies manifested that binding modes between 5-Fluorouracil and DNA were evidenced to be groove binding and in partial intercalative mode.

Aerosol-deposited BaFe_0.7Ta_0.3O_3-δ for nitrogen monoxide and temperature-independent oxygen sensing

The gas sensing properties of resistive gas sensors of BaFe0.7Ta0.3O3-δ (BFT30) prepared by the so-called aerosol deposition method, a method to manufacture dense ceramic films at room temperature, were investigated. The electrical response of the films was investigated first under various oxygen concentrations and in a wide temperature range between 350 and 900 °C. Between 700 and 900 °C, the conductivity of BaFe0.7Ta0.3O3-δ (BFT30) depends on the oxygen concentration with a slope of almost 1/4 in the double-logarithmic plot vs. oxygen partial pressure. In addition, the sensor response is temperature independent. BFT30 responds fast and reproducibly to changing oxygen partial pressures even at 350 °C. The cross-sensitivity has been investigated in environments with various gases (C3H8, NO, NO2, H2, CO, CO2, and H2O) in synthetic air between 350 and 800 °C. BFT30 exhibits good sensing properties to NO between 350 and 400 °C in the range from 1.5 to 2000 ppm with a high selectivity to the other investigated gas species. Thus this semiconducting ceramic material is a good candidate for a temperature-independent oxygen sensor at high temperatures with the application in exhausts and for a selective nitrogen monoxide (NO) sensor at low temperatures for air quality monitoring.

Relaxation Properties of the Solid Propellant Based on Hydroxyl-Terminated Polybutadiene

The polymer-based propellant is a typical viscoelastic material. Better understanding of the relaxation properties of the propellant in the storage conditions is of great importance for predicting the lifetime. Due to the component complexity of the composite propellants, the transformation relation between the relaxation modulus and the complex modulus may not be suitable for all kinds of propellants. In the present work, we focused on the transformation of the relaxation modulus and complex modulus for the HTPB propellant. The master curves for the relaxation modulus and the storage modulus of the aged/unaged HTPB propellants were obtained by performing the stress relaxation tests and DMA tests, respectively. It was found that there existed a great difference in the double logarithmic plot between relaxation modulus and storage modulus master curves. Moreover, the testing results for the relaxation modulus and the storage modulus were well fitted by an empirical transformation relation with three segment-related coefficients. These three coefficients were determined by using the unaged samples, and then were applied to estimate the relaxation modulus of the aged samples. A good agreement between the calculation and the experimental results was also found, revealing that the three coefficients were insensitive to the aging time.

A Comparative Study on the Viscoelastic Models for Rubbery Materials

The rubbery materials play an important role in the acoustic metamaterials composed of locally resonant structures. To determine the unusual behavior of the dynamic mass density and bulk modulus in acoustic metamaterials in detail, better understanding of the viscoelasticity of rubbery materials is necessary. In the present work, we demonstrated the difference between the fractional and integer constitutive models in describing the viscoelastic behaviors in terms of the natural rubber (NR) and silicone rubber (SR). Test results for the relaxation modulus show that the Maxwell model is not suitable for NR and SR. The fractional Scott-Blair model gave a better estimation for the relaxation modulus but had a more sophisticated relation than the classical Maxwell model did. Compared with the other constitutive models, the fractional Maxwell model gave a better description of the mechanical properties for NR and SR, but it involved four independent parameters to be determined experimentally. By fitting test results in the double logarithmic plot of the modulus and loading time, all the parameters of the fractional Maxwell model were obtained. The present work provided a base for the analysis of the membrane-type acoustic metamaterials.

Onset–potency relationship of nondepolarizing muscle relaxants: a reexamination using simulations

Nondepolarizing muscle relaxants (MRs) display an inverse onset–potency relationship, that is, less potent MRs display a more rapid onset. We have conducted the current investigation to estimate the impact of variable pharmacokinetic or pharmacodynamic properties of the MRs on potency and onset time, and on the onset–potency relationship. Using a model of neuromuscular transmission, we changed either the affinity of MRs for the postsynaptic receptors or the pharmacokinetic properties of the MRs. The elimination rate constant, k10, which defines the systemic clearance, was assigned one of 9 values and the transport rate constant, k12, one of 5 values. The transport rate constant into the effect compartment was constant (ke1 = 0.2 min–1). Only one parameter was altered at a time. With constant pharmacokinetics, a 100-fold decrease in affinity caused a proportional decrease in potency, but little change (0.02 min) in onset time. With constant affinity, increasing the clearance from 1 to 250 mL·kg–1·min–1 shortened the onset time from 7.2 to 0.7 min and decreased the potency 12-fold. In a double logarithmic plot, the onset–potency relationship was linear. Lesser affinities produce a nearly parallel rightward shift of the regression lines. The inverse onset–potency relationship may be explained by the pharmacokinetic factors producing changes in both the potency and onset times.

Nerve-Evoked Synchronous Release and High K+-Induced Quantal Events Are Regulated Separately by Synaptotagmin I at Drosophila Neuromuscular Junctions

The distal Ca2+-binding domain of synaptotagmin I (Syt I), C2B, has two Ca2+-binding sites. To study their function in Drosophila, pairs of aspartates were mutated to asparagines and the mutated syt I was expressed in the syt I–null background ( P[ syt I B-D1,2N] and P[ syt I B-D3,4N]). We examined the effects of these mutations on nerve-evoked synchronous synaptic transmission and high K+-induced quantal events at embryonic neuromuscular junctions. The P[ syt I B-D1,2N] mutation virtually abolished synaptic transmission, whereas the P[ syt I B-D3,4N] mutation strongly reduced but did not abolish it. The quantal content in P[ syt I B-D3,4N] increased with the external Ca2+ concentration, [Ca2+]e, with a slope of 1.86 in double-logarithmic plot, whereas that of control was 2.88. In high K+ solutions the quantal event frequency in P[ syt I B-D3,4N] increased progressively with [Ca2+]e between 0 and 0.15 mM as in control. In contrast, in P[ syt I B-D1,2N] the event frequency did not increase progressively between 0 and 0.15 mM and was significantly lower at 0.15 than at 0.05 mM [Ca2+]e. The P[ syt I B-D1,2N] mutation inhibits high K+-induced quantal release in a narrow range of [Ca2+]e (negative regulatory function). When Sr2+ substituted for Ca2+, nerve-evoked synchronous synaptic transmission was severely depressed and delayed asynchronous release was appreciably increased in control embryos. In high K+ solutions with Sr2+, the quantal event frequency was higher than that in Ca2+ and increased progressively with [Sr2+]e in control and in both mutants. Sr2+ partially substitutes for Ca2+ in synchronous release but does not support the negative regulatory function of Syt I.

Detection of biomacromolecules with fluorescent light-up probes

The emission properties of selected benzo[b]quinolizinium (acridizinium) derivatives in the presence of double-stranded DNA and proteins are presented. Spectrophotometric studies and linear dichroism (LD) spectroscopic experiments reveal that benzo[b]quinolizinium derivatives bind to DNA, mainly by intercalation. In contrast to the 9-aminobenzo[b]quinolizinium, which exhibits a moderate emission quantum yield in water, the 6-aminobenzo[b]quinolizinium ion as well as N-phenyl-9-aminobenzo[b]quinolizinium derivatives are almost nonfluorescent. The low intrinsic fluorescence quantum yields of the latter compounds are caused by conformational changes in the excited state, as shown by a linear double-logarithmic plot of the emission quantum yield vs. the solvent viscosity. Most notably, the fluorescence intensities of these dyes increase significantly by a factor of 10 to 50 upon addition of double-stranded DNA or proteins such as human serum albumin (HSA) or chicken egg albumin (CEA). Thus, these compounds exhibit ideal properties to be used as DNA- or protein-sensitive light-up probes.