bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental measurement of coherent structures in turbulent boundary layers using moving time-resolved particle image velocimetry
Authors: Wang Kangjun , Li Biaohui , Liu Lixia , Wang Chaowei , Jiang Nan
Published: November 2020

A moving time-resolved particle image velocimetry (MTRPIV) system was designed to measure the turbulent boundary layer (TBL). The combination of time-resolved particle image velocimetry and a translational moving system enables the MTRPIV to track the coherent structures with a long period and high temporal resolution. Based on the MTRPIV, the time-evolving of coherent structures within the TBL was measured and analyzed. The observation of the large-scale sweep collision with ejection shows that the strong collision causes the large-scale high- and low-speed coherent structures to break down. The time-evolving process of the hairpin packets shows that the low-speed fluid mass under the hairpin vortices is important for the generation of a whole hairpin packet. The small-scale low-speed structures increase their spatial scales by merging so that the independent hairpin vortices can be organized by merged larger-scale structures. The shear layer exceeding the length of 0.7–0.8 δ (δ is thickness of TBL) or 350–400 υUτ (υ and Uτ denote the kinematic viscosity and friction velocity, respectively) is unstable, and it will roll-up to generate a hairpin vortex. In the hairpin packet growth process, the inclination angle of the hairpin packet decreases from ∼13° to 8° in a time duration of 120 υUτ2, and the underlying low-speed fluid is elongated and then split. The analysis of the uniform momentum zones (UMZs) shows that the topmost UMZ has a relatively stable wall-normal position and convection speed. The lower UMZ is quasi-periodically generated and tends to move upward to merge with the upper UMZs. The hairpin packets impact the lower UMZs by inducing large-scale low-speed fluid mass to modulate the probability density function distribution of instantaneous streamwise velocity. The evolution of UMZs with velocity less than 0.5U∞ (U∞ denotes the free-stream velocity) is the result of the interaction of large- and small-scale streamwise fluctuation velocity.
Heat diffusion imaging: In-plane thermal conductivity measurement of thin films in a broad temperature range
Authors: Zhu Tianhui , Olson David H. , Hopkins Patrick E. , Zebarjadi Mona
Published: November 2020

This work combines the principles of the heat spreader method and the imaging capability of the thermoreflectance measurements to measure the in-plane thermal conductivity of thin films without the requirement of film suspension or multiple thermometer deposition. We refer to this hybrid technique as heat diffusion imaging. The thermoreflectance imaging system provides a temperature distribution map across the film surface. The in-plane thermal conductivity can be extracted from the temperature decay profile. By coupling the system with a cryostat, we were able to conduct measurements from 40 K to 400 K. Silicon thin film samples with and without periodic holes were measured and compared with in-plane time-domain thermoreflectance measurements and literature data as validation for heat diffusion imaging.
Dynamics of viscoelastic fluid in a rotating soft microchannel
Authors: Balasubramanian Srikumar , Kaushik P. , Mondal Pranab K.
Published: November 2020

In this study, we numerically investigate the effects of rotational forces, viz., centrifugal force and Coriolis force, on the flow dynamics of a viscoelastic fluid in a polymeric layer grafted microchannel. The viscoelastic fluid is represented by the Oldroyd-B model, and the effect of viscoelasticity on the underlying transport is studied. A numerical procedure consistent with the finite difference method is used to solve the system of partial differential equations. The numerical model takes into consideration, among many others, the drag effects of the “soft layer” and the transiences in the flow dynamics leading to the steady state. The complex interplay between the effect of rotational forcing and the presence of the soft layer is observed to lead to vital conclusions that could improve the design of many lab-on-a-compact disc based microfluidic devices. In addition, the effect of elasticity on the flow dynamics in the presence of rotational forces and soft layer induced drag force is studied. The in-house numerical code employs the finite difference numerical scheme to discretize the equations and consequently solves the obtained system of linear algebraic equations using the Gauss–Seidel iterative scheme. By demonstrating the velocity profiles, we discuss the effect of the various rheological parameters on the underlying transport feature. Finally, the effect of the rotation on the net throughput is studied extensively.
A generalized Boltzmann kinetic theory for strongly magnetized plasmas with application to friction
Authors: Jose Louis , Baalrud Scott D.
Published: November 2020

Coulomb collisions in plasmas are typically modeled using the Boltzmann collision operator, or its variants, which apply to weakly magnetized plasmas in which the typical gyroradius of particles significantly exceeds the Debye length. Conversely, O'Neil has developed a kinetic theory to treat plasmas that are so strongly magnetized that the typical gyroradius of particles is much smaller than the distance of the closest approach in a binary collision. Here, we develop a generalized collision operator that applies across the full range of magnetization strength. Since there is no closed-form solution for the scattering cross section when plasma is strongly magnetized, the input to the collision operator is obtained by numerically calculating particle trajectories. To demonstrate novel physics associated with strong magnetization, it is used to compute the friction force on a massive test charge. In addition to the traditional stopping power component, this is found to exhibit a transverse component that is perpendicular to both the velocity and Lorentz force vectors in the strongly magnetized regime, as was predicted recently using linear response theory. Good agreement is found between the collision theory and linear response theory in the regime in which both apply, but the new collision theory also applies to stronger magnetization strength regimes than the linear response theory is expected to apply in.
Unsteady combustion mode with a super-high frequency induced by a curved shock
Authors: Teng Honghui , Liu Shuai , Zhang Zijian
Published: November 2020

Previous studies of a high-speed blunt projectile in a combustible mixture found two oscillating unsteady combustion modes induced by the curved shock, referred to as high- and low-frequency modes. A new unsteady combustion mode is observed in the present study. The frequency reaches approximately twice the high frequency and is referred to as the super-high frequency to maintain consistency with the terminology used in previous works. The super-high-frequency mode appears in cases of a small sphere diameter, and with a proper diameter, an intermediate mode arises with the co-existence of both high and the super-high frequencies. An analysis of pressure and temperature gradients along the stagnation streamline attributes the oscillation of combustion to the interaction of compression and entropy waves between the shock and flame front. If the compression/entropy waves affect the flame front of the next cycle, the high-frequency mode arises; this is consistent with the results of previous works. However, weakened compression/entropy waves in cases of a small sphere diameter only affect the flame front of every other cycle, leading to the super-high-frequency mode.
Optical properties and structural coloration of chocolate
Authors: Galinski H. , Jeoffroy E. , Zingg A. , Grob L. , Rühs P. A. , Spolenak R. , Studart A. R.
Published: November 2020

Chocolate consists of cocoa butter, cocoa particles, sugar, and additives, which together determine its taste and optical properties. The optical properties of chocolate play a vital role in consumer perception, representing type and quality in the blink of an eye. Here, we present a comprehensive analysis of the optical properties of white, milk, and dark chocolate, while demonstrating how to craft orange to blue chocolate via a thin food-grade coating. Using Mie theory, we show that chocolate can be treated as a turbid solid, where cocoa butter acts as a glass-like dielectric while all other ingredients contribute to its scattering and absorption. We expect the proposed coating to be easily adapted to other food surfaces to bring color to a broader range of edible products.
Introduction to Focus Issue: Instabilities and nonequilibrium structures
Authors: Clerc Marcel G. , Coullet Pierre , Rojas Rene G. , Tlidi Mustapha
Published: November 2020

This Focus Issue on instabilities and nonequilibrium structures includes invited contributions from leading researchers across many different fields. The issue was inspired in part by the “VII Instabilities and Nonequilibrium Structures 2019” conference that took place at the Pontifica Universidad Católica de Valparaiso, Chile in December 2019. The conference, which is devoted to nonlinear science, is one of the oldest conferences in South America (since December 1985). This session has an exceptional character since it coincides with the 80th anniversary of Professor Enrique Tirapegui. We take this opportunity to highlight Tirapegui’s groundbreaking contributions in the field of random perturbations experienced by macroscopic systems and in the formation of spatiotemporal structures in such systems operating far from thermodynamic equilibrium. This issue addresses a cross-disciplinary area of research as can be witnessed by the diversity of systems considered from inert matter such as photonics, chemistry, and fluid dynamics, to biology.
Analytical study and parameter-sensitivity analysis of catalytic current at a rotating disk electrode
Authors: Selvi M SalaiMathi , Rajendran L , Abukhaled Marwan
Published: November 2020

A convective-diffusion equation with semi-infinite boundary conditions for rotating disk electrodes under the hydrodynamic conditions is discussed and analytically solved for electrochemical catalytic reactions. The steady-state catalytic current of the rotating disk electrode is derived for various possible values of parameters by using a new approach of the homotopy perturbation method. The theoretical approach in this paper is described, for the first time, on the basis of convection–diffusion equations for the kinetics of Fenton's reagent using a platinum rotating disk electrode. The obtained approximate analytical expression for the concentrations of ferric and ferrous ions for steady-state conditions are shown to be highly accurate when compared to numerical results and other approximations found in the literature. A sensitive analysis of parameters of the current and concentration is presented.
Microconical surface structuring of aluminium tubes by femtosecond laser processing
Authors: Wöbbeking Karl , Li Mingji , Schade Wolfgang , Hübner Eike G
Published: November 2020

Femtosecond laser microstructuring is a convenient technology for the targeted surface functionalization of various materials. Commonly, the structuring process is performed on planar surfaces. Here, we investigated femtosecond laser structuring of aluminium tubes. Process parameters, i.e. the number of pulses per spot on the surface and the line distance, have been transformed from a line-by-line process on planar samples towards a helical process. The process is based on laser treating the rotating tube while the laser beam is moved along the axis of the tube. A significant difference of the surface structure obtained on a cylinder in comparison to the planar geometry is revealed. With exactly matching process parameters, a strong increase of the dimensions of the surface structures on aluminium tubes has been observed. With a typical parameter set to achieve microconically structured aluminium, the cone height increases from 5 to 24 μm and the cone-to-cone distance from 13 to 59 μm. The structure sizes were found to be unaffected from the diameter of the tube within a range from 12 to 40 mm. A possible explanation for the increased structure size is given by altered particle redeposition. Two different parameter sets have been transformed from a planar geometry to the cylindrical geometry. Deep black aluminium tubes providing hydrophobicity with a water contact angle up to 148° and a thermal emissivity up to 87% are demonstrated.
Application of a Validated RP-HPLC Method in Solubility and Dissolution Testing for Simultaneous Estimation of Diacerein and Its Active Metabolite Rhein in Presence of Coformers in the Eutectic Tablet Formulation
Authors: Patel Rajeshri D , Raval Mihir K , Pethani Trupesh M
Published: November 2020

The present study aimed to develop and validate a novel reversed-phase high-performance liquid chromatography method for simultaneous estimation of Diacerein (DIA) and Rhein (Rh, alkaline degradation product and active metabolite) in the presence of various coformers used to prepare eutectic oral formulation. Chromatographic separations were achieved on a Phenomenex Gemini C18 column (250 mm × 4.6 mm, 5 μm) placed in the thermostated column oven at 40°C. The mobile phase, comprising of acetonitrile and 10 mM ammonium acetate (pH 3.0), was eluted through the gradient system with 0.8 mL/min flow rate at 254 nm detection and analytical run time of 14 min. Additionally, the method was validated for specificity, linearity, precision, accuracy, selectivity, limit of quantitation, limit of detection and robustness as per International Conference on Harmonization guideline. The developed method was applied for the comparison of drug release profiles of pure DIA and from prepared eutectic formulations for the quantitation of DIA and Rh in the multicomponent adducts. The achieved method advocated their applicability in routine quality control analysis of DIA formulations without interference of degraded product and excipients.
Liquid Chromatographic Methods for COVID-19 Drugs, Hydroxychloroquine and Chloroquine
Authors: Bilgin Zeynep Derya , Evcil Isil , Yazgi Didem , Binay Gokce , Okuyucu Genc Ceren , Gulsen Busra , Huseynova Aytaj , Ozdemir Ayse Zehra , Ozmen Emel , Usta Yakup , Ustun Suade , Caglar Andac Sena
Published: November 2020

COVID-19 has been a threat throughout the world since December 2019. In attempts to discover an urgent treatment regime for COVID-19, hydroxychloroquine (HCQ) and chloroquine (CQ) have been on solidarity clinical trial. However, many countries have pulled HCQ and CQ from their COVID-19 treatment regimens recently, some countries still continue using them for patients who have previously started HCQ and CQ and they may complete their course under the supervision of a doctor. HCQ and CQ are 4-aminoquinoline drugs and it is safe to use them for autoimmune diseases, rheumatoid arthritis, systemic lupus erythematosus and malaria as well. Determination of CQ, HCQ and their metabolites in biologic fluids and in pharmaceuticals has great importance, especially for pharmacokinetics, pharmacodynamics and epidemiological studies. In this review, liquid chromatographic methods developed in the last 10 years were summarized focusing on sample preparation and detection methods for HCQ and CQ determination in biological fluids and pharmaceutical preparations. It is hoped that this article could be helpful to facilitate the use of these drugs in clinical trials or drug research studies as it provides comprehensive information on the reported analytical methods.
Seismotectonic evidence for subduction beneath the Eastern Greater Caucasus
Authors: Gunnels Michael , Yetrimishli Gurban , Kazimova Sabina , Sandvol Eric
Published: November 2020

We generated high-resolution 3-D seismic velocity models as well as a relocated earthquake catalogue across the eastern Greater Caucasus and Kura basins. This work was done using data from the recently upgraded Republic Seismological Survey Center's (RSSC) seismic network. We generated our tomographic images of crustal velocity structure in Azerbaijan using double-difference inversions (i.e. tomoDD and hypoDD). Earthquake catalogues from the RSSC between 2011 and 2016 were used; these catalogues include absolute arrival times of 103 288 P- and 120 952 S-wave traveltime picks for 7574 events recorded at 35 stations in Azerbaijan. Beginning with a layered, 1-D velocity model that was estimated using VELEST, we inverted simultaneously for relative location, Vp and Vs on a 3-D grid with dimensions 670 × 445 × 45 km, with a uniform grid spacing of 55 × 55 × 5 km for all of Azerbaijan. We observe that the relocated hypocentres cluster into two depth ranges, at the surface and at depth, that appear to correspond to major fault zones and the top of a subducting plate. Additionally, we note intermediate depth seismicity (∼50–60 km) beneath the Kura Basin, and a northward deepening of earthquake depths. Seismic velocities vary significantly throughout the study region; we observe very slow velocities throughout the Kura Basin between 5 and 15 km, and elevated velocities at 20–35 km. The wholesale velocity structure and seismic structure of Kura Basin strongly mirrors that of the Caspian Sea, which suggests that the geodynamics of the Caspian continue westwards into Azerbaijan. The key results of this study suggest that the northward subduction observed in the Caspian Sea continues beneath the Eastern Greater Caucasus, as well as provides evidence for active faulting along the southern margin of the mountain range.
Accounting for uncertain 3-D elastic structure in fault slip estimates
Authors: Ragon Théa , Simons Mark
Published: November 2020

Earthquake source estimates are affected by many types of uncertainties, deriving from observational errors, modelling choices and our simplified description of the Earth’s interior. While observational errors are often accounted for, epistemic uncertainties, which stem from our imperfect description of the forward model, are usually neglected. In particular, 3-D variations in crustal properties are rarely considered. 3-D crustal heterogeneity is known to largely affect estimates of the seismic source, using either geodetic or seismic data. Here, we use a perturbation approach to investigate, and account for, the impact of epistemic uncertainties related to 3-D variations of the mechanical properties of the crust. We validate our approach using a Bayesian sampling procedure applied to synthetic geodetic data generated from 2-D and 3-D finite-fault models. We show that accounting for uncertainties in crustal structure systematically increases the reliability of source estimates.
Association of Reduced Long-Lasting Insecticidal Net Efficacy and Pyrethroid Insecticide Resistance With Overexpression of CYP6P4, CYP6P3, and CYP6Z1 in Populations of Anopheles coluzzii From Southeast Côte d’Ivoire
Authors: Meiwald Anne , Clark Emma , Kristan Mojca , Edi Constant , Jeffries Claire L , Pelloquin Bethanie , Irish Seth R , Walker Thomas , Messenger Louisa A
Published: November 2020

Background

Resistance to major public health insecticides in Côte d’Ivoire has intensified and now threatens the long-term effectiveness of malaria vector control interventions.

Methods

This study evaluated the bioefficacy of conventional and next-generation long-lasting insecticidal nets (LLINs), determined resistance profiles, and characterized molecular and metabolic mechanisms in wild Anopheles coluzzii from Southeast Côte d’Ivoire in 2019.

Results

Phenotypic resistance was intense: >25% of mosquitoes survived exposure to 10 times the doses of pyrethroids required to kill susceptible populations. Similarly, the 24-hour mortality rate with deltamethrin-only LLINs was very low and not significantly different from that with an untreated net. Sublethal pyrethroid exposure did not induce significant delayed vector mortality effects 72 hours later. In contrast, LLINs containing the synergist piperonyl butoxide, or new insecticides clothianidin and chlorfenapyr, were highly toxic to A. coluzzii. Pyrethroid-susceptible A. coluzzii were significantly more likely to be infected with malaria, compared with those that survived insecticidal exposure. Pyrethroid resistance was associated with significant overexpression of CYP6P4, CYP6P3, and CYP6Z1.

Conclusions

Study findings raise concerns regarding the operational failure of standard LLINs and support the urgent deployment of vector control interventions incorporating piperonyl butoxide, chlorfenapyr, or clothianidin in areas of high resistance intensity in Côte d’Ivoire.
The Best of Both Worlds: Compensation via Price-Caps for Passed-On Overcharges
Authors: Yarkoni Barak , Shalem Roy , Hannes Sharon
Published: November 2020

We present a market-based compensation approach to antitrust litigation and other cases of price overcharges. Instead of lump-sum compensation, paid either directly or through coupons, defendants are required to lower their prices for a certain designated period, i.e. price-cap compensation (PCC). We show why previous criticism of PCC was misguided. And, in sharp contrast to the common view in the literature, implementing PCC may have many substantive and procedural advantages. Importantly, although PCC is implemented vis-à-vis direct purchasers only, it reconciles the U.S. and European Union legal approaches and solves the challenge of passed-on damages to indirect purchasers.
Management of cerebrospinal fluid leak from cervical gunshot wounds with external ventricular drainage: a small case series
Authors: Crutcher Clifford L , Wilson John M , Morrow Kevin D , Shields Jessica A , Lasseigne Lindsay M , Culicchia Frank , Tender Gabriel
Published: November 2020

Historically, the surgical management of gunshot wounds to the spine has been controversial. Repair of a persistent cerebrospinal fluid (CSF) leak is a generally agreed upon indication. The management of such CSF leaks typically involves lumbar drainage or direct surgical repair. Here, the authors report two cases of CSF diversion with an external ventricular drain (EVD) in patients with cervical gunshot wounds. Both patients had spinal canal obliteration or physiologic myelographic block at or below the level of injury. To the best of the author’s knowledge, these are the first two reports of successful EVD treatment of persistent CSF leaks related cervical gunshot wounds. The authors also propose a CSF treatment algorithm for cervical gunshot wounds that includes EVD.
Identifying and mitigating noise sources in precision pulsar timing data sets
Authors: Goncharov Boris , Reardon D J , Shannon R M , Zhu Xing-Jiang , Thrane Eric , Bailes M , Bhat N D R , Dai S , Hobbs G , Kerr M , Manchester R N , Osłowski S , Parthasarathy A , Russell C J , Spiewak R , Thyagarajan N , Wang J B
Published: November 2020

Pulsar timing array projects measure the pulse arrival times of millisecond pulsars for the primary purpose of detecting nanohertz-frequency gravitational waves. The measurements include contributions from a number of astrophysical and instrumental processes, which can either be deterministic or stochastic. It is necessary to develop robust statistical and physical models for these noise processes because incorrect models diminish sensitivity and may cause a spurious gravitational wave detection. Here we characterize noise processes for the 26 pulsars in the second data release of the Parkes Pulsar Timing Array using Bayesian inference. In addition to well-studied noise sources found previously in pulsar timing array data sets such as achromatic timing noise and dispersion measure variations, we identify new noise sources including time-correlated chromatic noise that we attribute to variations in pulse scattering. We also identify ‘exponential dip’ events in four pulsars, which we attribute to magnetospheric effects as evidenced by pulse profile shape changes observed for three of the pulsars. This includes an event in PSR J1713+0747, which had previously been attributed to interstellar propagation. We present noise models to be used in searches for gravitational waves. We outline a robust methodology to evaluate the performance of noise models and identify unknown signals in the data. The detection of variations in pulse profiles highlights the need to develop efficient profile domain timing methods.
Exploring the Galaxy’s halo and very metal-weak thick disc with SkyMapper and Gaia DR2
Authors: Cordoni G , Da Costa G S , Yong D , Mackey A D , Marino A F , Monty S , Nordlander T , Norris J E , Asplund M , Bessell M S , Casey A R , Frebel A , Lind K , Murphy S J , Schmidt B P , Gao X D , Xylakis-Dornbusch T , Amarsi A M , Milone A P
Published: November 2020

In this work, we combine spectroscopic information from the SkyMapper survey for Extremely Metal-Poor stars and astrometry from Gaia DR2 to investigate the kinematics of a sample of 475 stars with a metallicity range of $-6.5 \le \rm [Fe/H] \le -2.05$ dex. Exploiting the action map, we identify 16 and 40 stars dynamically consistent with the Gaia Sausage and Gaia Sequoia accretion events, respectively. The most metal poor of these candidates have metallicities of $\rm [Fe/H]=-3.31\, \mathrm{ and }\, -3.74$, respectively, helping to define the low-metallicity tail of the progenitors involved in the accretion events. We also find, consistent with other studies, that ∼21 per cent of the sample have orbits that remain confined to within 3 kpc of the Galactic plane, that is, |Zmax| ≤ 3 kpc. Of particular interest is a subsample (∼11 per cent of the total) of low |Zmax| stars with low eccentricities and prograde motions. The lowest metallicity of these stars has [Fe/H] = –4.30 and the subsample is best interpreted as the very low-metallicity tail of the metal-weak thick disc population. The low |Zmax|, low eccentricity stars with retrograde orbits are likely accreted, while the low |Zmax|, high eccentricity pro- and retrograde stars are plausibly associated with the Gaia Sausage system. We find that a small fraction of our sample (∼4 per cent of the total) is likely escaping from the Galaxy, and postulate that these stars have gained energy from gravitational interactions that occur when infalling dwarf galaxies are tidally disrupted.
‘Novae, supernovae, or something else?’ – (super-)nova highlights from Hoffmann & Vogt are quite certainly comets (ad 668 and 891)
Authors: Neuhäuser Ralph , Neuhäuser Dagmar L , Chapman Jesse
Published: November 2020

Galactic novae and supernovae can be studied by utilizing historical observations, yielding explosion time, location on sky, etc. Recent publications by Hoffmann & Vogt present CVs (Cataclysmic Variables), supernova remnants, planetary nebulae, etc. as potential counterparts based on their list of historically reported transients from the Classical Chinese text corpus. Since their candidate selection neglects the state-of-the-art (e.g. Stephenson & Green), and since it includes ‘broom stars’ and ‘fuzzy stars’, i.e. probable comets, we investigate their catalogue in more detail. We discuss here their two highlights, the suggestion of two ‘broom star’ records dated ad 667 and 668 as one historical supernova and of the ‘guest star’ of ad 891 as recurrent nova U Sco. The proposed positional search areas are not justified due to translation and dating problems, source omission, as well as misunderstandings of historical Chinese astronomy and unfounded textual interpretations. All sources together provide strong evidence for comet sightings in both ad 668 and 891 – e.g. there are no arguments for stationarity. The ad 667 record is a misdated doublet of 668. Our critique pertains more generally to their whole catalogue of ‘24 most promising events’: their speculations on counterparts lack a solid foundation and should not be used in follow-ups.
Design and application of circular RNAs with protein-sponge function
Authors: Schreiner Silke , Didio Anna , Hung Lee-Hsueh , Bindereif Albrecht
Published: November 2020

Circular RNAs (circRNAs) are a class of noncoding RNAs, generated from pre-mRNAs by circular splicing of exons and functionally largely uncharacterized. Here we report on the design, expression, and characterization of artificial circRNAs that act as protein sponges, specifically binding and functionally inactivating hnRNP (heterogeneous nuclear ribonucleoprotein) L. HnRNP L regulates alternative splicing, depending on short CA-rich RNA elements. We demonstrate that designer hnRNP L-sponge circRNAs with CA-repeat or CA-rich sequence clusters can efficiently and specifically modulate splicing-regulatory networks in mammalian cells, including alternative splicing patterns and the cellular distribution of a splicing factor. This new strategy can in principle be applied to any RNA-binding protein, opening up new therapeutic strategies in molecular medicine.
Metabolomic Analysis Identified Reduced Levels of Xenobiotics, Oxidative Stress, and Improved Vitamin Metabolism in Smokers Switched to Vuse Electronic Nicotine Delivery System
Authors: Liu Gang , Lin Chi Jen , Yates Charles R , Prasad G L
Published: November 2020

Introduction

Switching to noncombustible tobacco products presents an opportunity for cigarette smokers to potentially reduce the health risks associated with smoking. Electronic Nicotine Delivery Systems (ENDS) are one such product because the vapor produced from ENDS contains far fewer toxicants than cigarette smoke. To investigate the biochemical effects of switching from smoking to an ENDS, we assessed global metabolomic profiles of smokers in a 7-day confinement clinical study.

Methods

In the first 2 days of this clinical study, the subjects used their usual brand of cigarettes and then switched to exclusive ENDS ad libitum use for 5 days. Urine and plasma samples were collected at baseline and 5 days after switching. The samples were analyzed using a mass spectrometry-based metabolomic platform.

Results

Random forest analyses of urine and plasma metabolomic data revealed excellent predictive accuracy (>97%) of a 30-metabolite signature that can differentiate smokers from 5-day ENDS switchers. In these signatures, most biomarkers are nicotine-derived metabolites or xenobiotics. They were significantly reduced in urine and plasma, suggesting a decreased xenobiotic load on subjects. Our results also show significantly decreased levels of plasma glutathione metabolites after switching, which suggests reduced levels of oxidative stress. In addition, increased urinary and plasma levels of vitamins and antioxidants were identified, suggesting enhanced bioavailability due to discontinuation of cigarette smoking and switching to Vuse ENDS use.

Conclusions

Our results suggest reduced toxicant exposure, reduced oxidative stress, and potential beneficial changes in vitamin metabolism within 5 days in smokers switching to Vuse ENDS.

Implications

Switching from smoking to exclusive ENDS use in clinical confinement settings results in significant reduction of nicotine metabolites and other cigarette-related xenobiotics in urine and plasma of subjects. Significantly decreased oxidative stress-related metabolites and increased urinary and plasma levels of vitamin metabolites and antioxidants in 5-day short-term ENDS switchers suggest less toxic physiological environment for consumers of ENDS products and potential health benefits if such changes persist.
Sexually Transmitted Infection Diagnoses and Access to a Sexual Health Service Before and After the National Lockdown for COVID-19 in Melbourne, Australia
Authors: Chow Eric P F , Hocking Jane S , Ong Jason J , Phillips Tiffany R , Fairley Christopher K
Published: November 2020

Background

We aimed to examine the impact of lockdown on sexually transmitted infection (STI) diagnoses and access to a public sexual health service during the coronavirus disease 2019 (COVID-19) pandemic in Melbourne, Australia.

Methods

The operating hours of Melbourne Sexual Health Centre (MSHC) remained the same during the lockdown. We examined the number of consultations and STIs at MSHC between January and June 2020 and stratified the data into prelockdown (February 3 to March 22), lockdown (March 23 to May 10), and postlockdown (May 11 to June 28), with 7 weeks in each period. Incidence rate ratios (IRRs) and their 95% confidence intervals (CI) were estimated using Poisson regression models.

Results

The total number of consultations dropped from 7818 in prelockdown to 4652 during lockdown (IRR, 0.60; 95% CI, 0.57–0.62) but increased to 5347 in the postlockdown period (IRR, 1.15; 95% CI, 1.11–1.20). There was a 68% reduction in asymptomatic screening during lockdown (IRR, 0.32; 95% CI, 0.30–0.35), but it gradually increased during the postlockdown period (IRR, 1.59; 95% CI, 1.46–1.74). Conditions with milder symptoms showed a marked reduction, including nongonococcal urethritis (IRR, 0.60; 95% CI, 0.51–0.72) and candidiasis (IRR, 0.61; 95% CI, 0.49–0.76), during lockdown compared with prelockdown. STIs with more marked symptoms did not change significantly, including pelvic inflammatory disease (IRR, 0.95; 95% CI, 0.61–1.47) and infectious syphilis (IRR, 1.14; 95% CI, 0.73–1.77). There was no significant change in STI diagnoses during postlockdown compared with lockdown.

Conclusions

The public appeared to be prioritizing their attendance for sexual health services based on the urgency of their clinical conditions. This suggests that the effectiveness of clinical services in detecting, treating, and preventing onward transmission of important symptomatic conditions is being mainly preserved despite large falls in absolute numbers of attendees.
Spiritual Well-Being in People Living with Persistent Non-Cancer and Cancer-Related Pain
Authors: Lovell Melanie , Corbett Mandy , Dong Skye , Siddall Philip
Published: November 2020

Context

Existential and spiritual factors are known to play an important role in how people cope with disability and life-threatening illnesses such as cancer. However, comparatively little is known about the impact of pain on factors such as meaning and purpose in one’s life and their potential roles in coping with pain.

Objectives

The aim of this study was to determine spiritual well-being scores in people with persistent pain and to compare these with people with cancer and healthy controls.

Methods

We assessed 132 people with chronic pain, 74 people with cancer (49 with pain and 25 without pain) and 68 control participants using standardised measures of pain-related variables including pain intensity, physical function, mood and cognitions. Spiritual well-being was also assessed using a validated and widely used questionnaire, the Functional Assessment of Chronic Illness Therapy – Spirituality Scale (FACIT-Sp).

Results

Spiritual well-being scores were significantly lower in people with persistent pain when compared with controls and were no different when compared with people with cancer, including those who had cancer and pain. In addition, low levels of meaning and purpose were significant predictors of depression, anxiety, and stress across all groups.

Conclusion

The findings demonstrate that persistent pain is associated with spiritual distress that is equal to those observed in people who have cancer. Furthermore, those who have higher levels of meaning and purpose are less likely to develop mood dysfunction when experiencing pain, indicating they may have a protective role.
Explore comorbidities associated with systemic lupus erythematosus: a total population-based case–control study
Authors: Chen J -H , Lee C T -C
Published: November 2020

Background

Because of the increasing incidence and overall burden of systemic lupus erythematosus (SLE), efforts have been made to identify the factors that contribute to SLE onset and progression.

Aim

We conducted a total population-based case–control study to explore the prior comorbidities associated with SLE.

Design and methods

Data were collected from Taiwan’s National Health Insurance Research Database. Newly diagnosed SLE patients from 1 January 2010, to 31 December 2013 (n = 2847), were exactly matched at a 1:4 ratio for gender, age, residence and insurance premium to form a non-SLE group. Multivariate conditional logistic regression with stepwise selection was used to find the prior-associated comorbidities.

Results

A total of 38 prior comorbidities were associated with SLE incidence (32 positive and 6 negative associations). Positively associated comorbidities could be categorized as autoimmune-related inflammation of multiple organs including skin, blood, liver, tooth, thyroid, musculoskeletal and connective tissue. Among them, diffuse diseases of connective tissue (International Classification of Disease, Ninth Revision, Clinical Modification 710) exhibited the most robust association (OR = 5.68, 95% CI = 4.02–8.03, P < 0.001) in the 5 years before the index date. Negatively associated comorbidities could be attributed to diabetes mellitus and pregnancy related symptoms.

Conclusions

Our results supported that increased awareness of SLE may be warranted for patients with autoimmune-related comorbidities of multiple organs. However, diabetes mellitus and pregnancy related symptoms were negatively associated with SLE incidence in this study. Further studies are warranted to elucidate the possible underlying mechanism and for better understanding the pathogenesis of SLE.
The Multilocus Multispecies Coalescent: A Flexible New Model of Gene Family Evolution
Authors: Li Qiuyi , Scornavacca Celine , Galtier Nicolas , Chan Yao-Ban
Published: November 2020

Incomplete lineage sorting (ILS), the interaction between coalescence and speciation, can generate incongruence between gene trees and species trees, as can gene duplication (D), transfer (T), and loss (L). These processes are usually modeled independently, but in reality, ILS can affect gene copy number polymorphism, that is, interfere with DTL. This has been previously recognized, but not treated in a satisfactory way, mainly because DTL events are naturally modeled forward-in-time, while ILS is naturally modeled backward-in-time with the coalescent. Here, we consider the joint action of ILS and DTL on the gene tree/species tree problem in all its complexity. In particular, we show that the interaction between ILS and duplications/transfers (without losses) can result in patterns usually interpreted as resulting from gene loss, and that the realized rate of D, T, and L becomes nonhomogeneous in time when ILS is taken into account. We introduce algorithmic solutions to these problems. Our new model, the multilocus multispecies coalescent, which also accounts for any level of linkage between loci, generalizes the multispecies coalescent (MSC) model and offers a versatile, powerful framework for proper simulation, and inference of gene family evolution. [Gene duplication; gene loss; horizontal gene transfer; incomplete lineage sorting; multispecies coalescent; hemiplasy; recombination.]
Toxicological evaluation of transgenic silkworms
Authors: Jiang Liang , Wang Yumei , Guo Huizhen , Sun Qiang , Xie Enyu , Liuli Haoyu , Li Qing , Xia Qingyou
Published: November 2020

Safety of transgenic silkworms must be evaluated before their commercial application. We assessed subacute toxicity using a 28-day feeding study in rats. Eighty rats were evenly allocated into four groups, with each group containing 10 male and 10 female rats. Rats of three groups were fed dried transgenic silkworm H19.9A pupae with overexpressed endogenous Bmhsp19.9, transgenic silkworm A4SOR pupae with overexpressed exogenous SOR, or normal silkworm pupae at a dose of 3.0 g/kg/day, respectively. The fourth group served as a normal feeding control. The body weight, feed consumption, hematology response variables, serum biochemical parameters, organ weights, gross necropsy, and histopathologic of animals were evaluated. No mortality, adverse effects, or major differences in the evaluated parameters were observed in the groups fed transgenic pupae in comparison with the control, suggesting that transgenic silkworms are toxicologically equivalent to normal silkworms and are safe for consumption in rats.
Intravenous doxapram administration as a potential model of panic attacks in rats
Authors: Batista Luara A. , Lopes Jadna B. , Brianis Rayssa C. , Haibara Andrea S. , Moreira Fabrício A.
Published: November 2020

Panic disorder can be categorized into the nonrespiratory or the respiratory subtypes, the latter comprising dyspnea, shortness of breath, chest pain, feelings of suffocation, and paresthesias. Doxapram is an analeptic capable of inducing panic attacks with respiratory symptoms in individuals diagnosed with the disorder; however, its neuroanatomical targets and its effects on experimental animals remain uncharacterized. One of the brain regions proposed to trigger panic attacks is the midbrain periaqueductal gray (PAG). Therefore, in this study, we evaluated the effects of doxapram in Fos (c-Fos) protein expression in the PAG and characterized its cardiorespiratory and behavioral effects on the elevated T maze and in the conditioned place aversion (CPA) paradigms. Doxapram increased Fos expression in different columns of the PAG, increased respiratory frequency, decreased heart rate, and increased arterial pressure when injected via intravenous route. Alprazolam, a panicolytic benzodiazepine, injected via intraperitoneal route, decreased respiratory frequency, whereas URB597, an anandamide hydrolysis inhibitor injected via intraperitoneal route, was ineffective. Doxapram injected via intraperitoneal route induced an anxiogenic-like effect in the elevated T-maze model; however, it failed to induce CPA. This study suggests that the cardiorespiratory and behavioral effects of doxapram in rodents serve as an experimental model that can provide insights into the neurobiology of panic attacks.
Comprehensive Outcomes Evaluation After Percutaneous Coronary Intervention in Stable Ischemic Heart Disease and Acute Coronary Syndrome for Short- Versus Standard-Term Dual Antiplatelet Therapy: A Systematic Review and Meta-analysis of Randomized Control Trials
Authors: Bhattarai Mukul , Ibrahim Abdisamad M. , Salih Mohsin , Tandan Nitin , Al-Akchar Mohammad , Ayan Mohamed , Kulkarni Abhishek , Hafiz Abdul M.
Published: November 2020

Newer generation drug eluting stents (DES) and pharmacotherapy have decreased thrombotic events post-percutaneous coronary intervention (PCI). There is lack of wide-ranging safety and efficacy evaluation in both stable ischemic heart disease and acute coronary syndrome in short-term (3–6 months) versus Standard-term (12 months) dual antiplatelet therapy (DAPT). We searched electronic databases using specific terms to identify randomized control trials comparing different durations of DAPT after PCI with DES. The outcomes of interest included all-cause mortality, myocardial infarction, stent thrombosis, major bleeding, target lesion and vessel revascularization, and stroke at follow-up duration ≥12 months post index PCI. Studies that compared DAPT <3 months or DAPT ≥12 months were excluded. Thirteen randomized control trials (n = 31,831) were included; 8401 patients received DAPT for 3 months and 7482 patients received DAPT in the 6 months group. Major bleeding rate was lower in the short-term (3–6 months) versus Standard-term (12 months) group (risk ratio 0.66; 95% confidence interval, 0.52–0.84, P < 0.05). Repeat revascularization rate was higher in the short-term (3–6 months) versus Standard-term (12 months) (risk ratio 1.17; 95% confidence interval, 1.01–1.36, P < 0.05) of DAPT duration after PCI with DES. No difference in other outcomes were observed when comparing short versus standard duration of DAPT in both stable ischemic heart disease and acute coronary syndrome.
Breast cancer in global health: beyond diversity and inequality
Authors: Liu Lin , Kawashima Masahiro , Toi Masakazu
Published: November 2020

Over the past 50 years, we have seen several innovations and breakthroughs in breast cancer screening, molecular diagnosis, prevention, and adjuvant treatment, which have led to a substantial reduction in mortality. However, upon looking at its prevalence on a global scale, this achievement seems to be limited to western and some developed countries. The mortality of breast cancer is stable or even increasing in most other countries, and is a major threat to women’s global health. According to the worldwide epidemiological data and recent advances in genetics, we have begun to understand that there may be geographic, racial, ethnic, and possibly cultural diversity in terms of genetic predisposition, age-standardized incidence, and mortality of breast cancer. A deeper understanding of this potential diversity is essential to establish screening and prevention schemes as well as systematic treatments that are optimized for the epidemiological and genetic characteristics of each region. Considering most of the key evidence regarding breast cancer has been generated mainly in western countries, multidisciplinary global communication will facilitate understanding of breast cancer diversity, promote the equality and individualization of breast management, and improve breast cancer survival worldwide.
Our round Japanese fan-like flap decreases complications: case reports of distally based sural flap
Authors: Uemura Tetsuji , Watanabe Hidetaka , Yanai Tetsu , Kawano Hiroshige
Published: November 2020

Introduction:

We report a modified distally based sural flap in the shape of a pedicle, based on deep fascia, which we call a “round Japanese folding fan-like flap,” that decreases the complication rate because our modified flap promotes reverse venous return through existing adipofascial tissue.

Presentation of cases:

A retrospective chart review was conducted on patients that underwent distally based sural flap reconstruction between 1994 and 2018 in Saga University Hospital and other related hospitals. We treated 25 patients (17 men and 8 women) who suffered from different etiological causes, for example, malignant tumors, trauma, osteomyelitis of the heel, and/or a diabetic foot. The mean flap size was 12.0 cm×7.0 cm (range: 7–20 cm×3–13 cm). All flaps survived, although 1 flap from among the 5 patients treated with standard distally based sural flap reconstruction before 2000 suffered from partial necrosis due to venous congestion. None of the 20 patients treated with the round Japanese fan-like flap have developed either partial or complete flap necrosis due to venous congestion. No other complications concerning the flap or donor site were observed.

Discussion:

The elevation of distally based sural flap is quick and easy to locate, however, it has been associated with complications, for example, postoperative venous congestion.

Conclusion:

The round Japanese fan-like flap (shaped from the pedicle to the distal area of the flap) promotes reverse venous return through existing adipofascial tissue, thus preventing the development of flap necrosis. This flap is able to cover a large wound defect of the ankle bone and cover the tendon with deep fascia by using a wrapping technique to treat the exposed tendon. Furthermore, our flap can be applied to many patients with large wound defects and/or diabetic foot patients.
Pound-shape Silicone Oil Retention Suture in Aphakic Eyes With Intact Iris
Authors: Jun Sung Yeon , Son Gisung
Published: November 2020

Purpose:

To introduce a surgical technique, “pound-shape silicone oil retention suture in aphakic eye with intact iris.”

Methods:

A retrospective analysis of medical records was performed. Each patient had an aphakic eye with intact iris and received the pound-shape silicone oil retention suture during vitrectomy combined with silicone oil injection.

Results:

In the four patients who received the pound-shape silicone oil retention suture, the silicone oil was confined behind the suture for 3 months to 7 months without prolapse into the anterior chamber. Increased intraocular pressure was not observed in any patient, although peripheral iridectomy was not performed.

Conclusion:

Pound-shape silicone oil retention suture is a simple and effective surgical technique to prevent silicone oil prolapse into the anterior chamber.