bluuebunny/crossref_metadata_2025 huggingface dataset:
Adeno-Associated Virus-Mediated Knockdown of SLC16A11 Improves Glucose Tolerance and Hepatic Insulin Signaling in High Fat Diet-Fed Mice
Authors: Zhang Tan , Qi Zhengtang , Wang Haiyan , Ding Shuzhe
Published: June 2019

Background SLC16A11, a member of the SLC16 family, is associated with lipid metabolism, causing increased intracellular triacylglycerol (TAG) levels. In the current study, our primary goal was to determine if an SLC16A11 knockdown would improve glucose tolerance and hepatic insulin signaling in high fat diet (HFD)–fed mice. Additionally, the mechanism for exercise-improved insulin sensitivity remains unclear, and there is no mechanistic insight into SLC16A11’s role in insulin sensitivity under exercise stress. Therefore, we also examined the impact of endurance exercise on the abundance of SLC16A11.

Methods C57BL/6 J male mice were fed either regular chow (Control) or HFD for 8 weeks and then injected with adeno-associated virus (AAV). Plasma parameters, tissue lipid contents, glucose tolerance, and expression profiles of hepatic insulin signaling were detected. Also, other mice were divided randomly into sedentary and exercise groups. We assessed hepatic expression of SLC16A11 after 8 weeks of endurance exercise.

Results 1) Hepatic SLC16A11 expression was greater in HFD-fed mice compared to Control mice. 2) AAV-mediated knockdown of SLC16A11 improved glucose tolerance, prevented TAG accumulation in serum and liver, and increased phosphorylation of protein kinase B (Akt) and glycogen synthesis kinase-3β (GSK3β) in HFD-fed mice. 3) Endurance exercise decreased hepatic SLC16A11 expression.

Conclusions Inactivation of SLC16A11, which is robustly induced by HFD, improved glucose tolerance and hepatic insulin signaling, independent of body weight, but related to TAG. Additionally, SLC16A11 might mediate the health benefits of endurance exercise.
Von geschwächten Barrieren
Authors: Grafen Keren
Published: June 2019

In der Darmschleimhaut und den Gehirnkapillaren verkitten belastbare Proteinverbindungen - Tight junctions - die Epithelzellen zu einer dicht schließenden Barriere gegen unerwünschte Substanzen und Fremdkörper. Über das Immun- und Stoffwechselsystem stehen die Durchlässigkeit der Darmschleimhaut und der Blut-Hirn-Schranke in enger wechselseitiger Verbindung. Daher gehen Darmstörungen häufig mit subklinischer Neuroinflammation und geistiger Dysbalance einher. Im Fall Johanna P. konnten massive Darm- und Depressionsbeschwerden mit einer Kombination aus Probiotika, Glutamin, Zink, glutenfreier Ernährung und Bewegung erfolgreich behandelt werden.
Hitzewelle auf Chinesisch
Authors: Bögel Martina
Published: June 2019

Hitzemuster stellen einen zentralen pathogenen Faktor in der Chinesischen Medizin dar und finden sich bei diversen Erkrankungen, wie die Beispiele Infektionen, Stress und Wechseljahresbeschwerden zeigen. Für eine gezielte Behandlung muss der Therapeut unter anderem das betreffende Organ, die Wandlungsphase (zum Beispiel Feuer), und die Schicht (nach dem Vier-Schichten-Modell) identifizieren. Abhängig davon, ob es sich um Leere- oder Füllezustände, äußere oder innere Muster handelt, haben sich spezifische Akupunkturpunkte und Arzneirezepturen bewährt.
Imaging of Multiple Myeloma
Authors: Kosmala Aleksander , Bley Thorsten , Petritsch Bernhard
Published: June 2019

Background Multiple myeloma is a malignant hematological disease characterized by uncontrolled proliferation of monoclonal plasma cells mainly in the bone marrow. Imaging plays a crucial role in diagnosis and follow-up.

Method This literature review provides information about multiple myeloma, its precursor diseases, and available imaging techniques. Advantages and limitations as well as possible prognostic and therapeutic implications of the different imaging methods are presented in the context of the current literature.

Results and Conclusion Cross-sectional imaging has replaced conventional X-ray skeletal survey. Widely available whole-body computed tomography is routinely used to detect osteolytic lesions. Magnetic resonance imaging is the most sensitive technique to identify bone marrow infiltration and is recommended in multiple myeloma precursor diseases. Positron emission computed tomography combines morphological and functional imaging. It is mainly used for follow-up, therapy monitoring, and response evaluation.

Key points: 

Citation Format
Vielseitiger Scharfmacher
Authors: Houben Martina
Published: June 2019

Der Wurzelstock des Echten Galgant (Alpinia officinarum) wird in der traditionellen Heilkunde und modernen Phytotherapie bei zahlreichen Indikationen angewendet. Außerdem ist die Gewürzpflanze in der Küche beliebt.
Time Course Changes in Confirmed ‘True’ VO2max After Individualized and Standardized Training
Authors: Weatherwax Ryan , Harris Nigel , Kilding Andrew E. , Dalleck Lance
Published: June 2019

This study sought to examine time course changes in maximal oxygen consumption (VO2max) confirmed with verification testing following 12 weeks of standardized vs. individualized exercise training. Participants (N=39) were randomly allocated to differing exercise intensity prescription groups: ventilatory threshold (individualized) or % heart rate reserve (standardized). At baseline, 4, 8, and 12 weeks, participants completed maximal exercise testing with a verification protocol to confirm ‘true VO2max.’ VO2max in the standardized group changed from 24.3±4.6 ml·kg−1·min−1 at baseline to 24.7±4.6, 25.9±4.7, and 26.0±4.2 ml·kg−1·min−1 at week 4, 8, and 12, respectively, with a significant difference (p<0.05) in VO2max at week 8 and 12 compared to baseline. The individualized group had increases in VO2max from online 2 9.5±7.5 ml·kg−1·min−1 at baseline to 30.6±8.4, 31.4±8.4, and 32.8±8.6 ml·kg−1·min−1 at week 4, 8, and 12, respectively. In the individualized group, there were significant differences (p<0.05) in VO2max from baseline to week 8 and 12 and a significant increase in VO2max from week 8 to 1 online 2. Although not statistically significant, our preliminary data demonstrates a more rapid and potent improvement in VO2max when exercise intensity is individualized. This is the first investigation to employ use of the verification procedure to confirm ‘true VO2max’ changes following exercise training using ventilatory thresholds.
Antcin-A Modulates Epithelial-to-Mesenchymal Transition and Inhibits Migratory and Invasive Potentials of Human Breast Cancer Cells via p53-Mediated miR-200c Activation
Authors: Kumar K. J. Senthil , Vani M. Gokila , Hsieh Han-Wen , Lin Chin-Chung , Wang Sheng-Yang
Published: June 2019

Antcin-A (ATA) is a steroid-like phytochemical isolated from the fruiting bodies of a precious edible mushroom Antrodia cinnamomea. We previously showed that ATA has strong anti-inflammatory and anti-tumor effects; however, other possible bioactivities of this unique compound remain unexplored. In the present study, we aimed to investigate the modulation of epithelial-to-mesenchymal transition (EMT), anti-migration, and anti-invasive potential of ATA against human breast cancer cells in vitro. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were incubated with ATA for 24 h. Wound healing, trans-well invasion, western blot, q-PCR, F-actin staining, and immunofluorescence assays were performed. We found that treatment with ATA significantly blocked EMT processes, as evidenced by upregulation of epithelial markers (E-cadherin and occludin) and downregulation of mesenchymal markers (N-cadherin and vimentin) via suppression of their transcriptional repressor ZEB1. Next, we found that ATA could induce miR-200c, which is a known player of ZEB1 repression. Further investigations revealed that ATA-mediated induction of miR-200c is associated with transcriptional activation of p53, as confirmed by the fact that ATA failed to induce miR-200c or suppress ZEB1 activity in p53 inhibited cells. Further in vitro wound healing and trans-well invasion assays support that ATA could inhibit migratory and invasive potentials of breast cancer cells, and the effect was likely associated with induced phenotypic modulation. Taken together, the present study suggests that antcin-A could be a lead phyto-agent for the development of anti-metastatic drug for breast cancer treatment.
Higenamine, a Dual Agonist for β
1- and β
2-Adrenergic Receptors Identified by Screening a Traditional Chinese Medicine Library
Authors: Chen Yanmin , Guo Bujing , Zhang Hongda , Hu Lihong , Wang Jue
Published: June 2019

Chronic heart failure is the terminal stage of various cardiovascular diseases. Despite the availability of several classes of drugs, there is still an unmet need for effective treatment. Based on bench work during the past two decades, we have proposed that enhancement of β
2-adrenergic receptor signaling in combination with the presently preferred β
1-adrenergic receptor blockade would be a promising strategy. Chinese herbal medicines have been shown to be effective in the treatment of heart failure, although the mechanisms largely remain unknown. In the present study, we screened an herbal medicine compound/extract library for β-adrenergic receptor ligands to determine the target of certain effective botanical remedies and seek a leading compound(s) for chronic heart failure treatment. Using a high-throughput screening assay, we identified higenamine, which has a long history in chronic heart failure treatment in traditional Chinese medicine, to be a potent β-adrenergic receptor agonist. Further experiments using specific inhibitors showed that higenamine activated both β
1-adrenergic receptor and β
2-adrenergic receptor. Inhibition of its action by pertussis toxin (a Gi inhibitor) indicated that it is a β
2-adrenergic receptor Gs/Gi dual agonist. Contractility experiments demonstrated a positive inotropic effect of higenamine. In conclusion, we found an herbal compound, higenamine, to be a dual agonist for β
1/β
2-adrenergic receptors with no preference in stimulating the Gs and Gi pathways in β
2-adrenergic receptor signaling. Our results elucidated not only the target of higenamine to explain its pharmacological effect in treating chronic heart failure, but also the mechanisms of its cardiac toxicity.
New Alkene Cyclopropanation Reactions Enabled by Photoredox Catalysis via Radical Carbenoids
Authors: Herraiz Ana G. , Suero Marcos G.
Published: June 2019

We describe the recent emergence of a new approach for the synthesis of cyclopropane rings by means of photoredox catalysis. This methodology relies on the photocatalytic generation of radical carbenoids or carbenoid-like radicals as cyclopropanating species, and is characterized by excellent functional group tolerance, chemoselectivity and the ability to form cyclopropanes with excellent control from E/Z alkene mixtures. The mild reaction conditions and employment of user-friendly reagents are highly attractive features that may lead to this approach being used in academic and industrial laboratories.

1 Introduction

2 Photoredox-Catalyzed Alkene Cyclopropanations with Radical Carbenoids

3 Conclusions and Outlook
Infertility Services for Veterans: Policies, Challenges, and Opportunities
Authors: Edmonds Stephanie W. , Zephyrin Laurie C. , Christy Alicia , Ryan Ginny L.
Published: June 2019

Infertility prevalence and care needs among male and female Veterans are understudied topics. The Veterans Health Administration (VHA) medical benefits package covers full infertility evaluation and many infertility treatments for Veterans but not, by law, for their spouses. In vitro fertilization (IVF) is also specifically excluded from this medical benefits package by regulation. Congress passed a law in 2016 that allowed VHA to provide IVF to Veterans and their legal spouses, and broader infertility benefits to the legal spouse, if the Veteran has a service-connected condition associated with his or her infertility, with some limitations. As the Veteran population becomes increasingly female, research efforts in reproductive health, including infertility, are expanding and evolving. This includes a nationwide study currently underway examining infertility among male and female Veterans and associations with military-related trauma, such as injury, posttraumatic stress disorder, military sexual trauma, and toxin exposure. In this review, we describe the state of the science and policy on infertility care in the VHA along with challenges and opportunities that exist within the VHA system.
Obstetric Outcomes in U.S. Veterans: Emerging Knowledge, Considerations, and Gaps
Authors: Hugin Michele , Shaw Jonathan G.
Published: June 2019

In the post-9/11 era, the number of young women serving, and deploying, in the military grew rapidly; as they exit service, there is tremendous increase in reproductive-aged women Veterans. Here, we review the limited but growing research regarding Veterans' pregnancy and obstetric outcomes. U.S. women Veterans returning from deployment carry a high burden of physical and mental health conditions, and often trauma. As poor mental health is known to predict poorer maternal and infant sequelae, there are unique concerns around perinatal outcomes in Veterans. Accordingly, there is new attention to their reproductive risks and needs—evidenced by recent research and programmatic efforts within the VA. Emerging research suggests that the unique health profiles of pregnant Veterans, including prevalent posttraumatic stress disorder, predict increased risk of preterm birth, preeclampsia, and gestational diabetes. In the most contemporary large study, relying on California birth data, Veterans who relied on VA for their health care coverage were high risk, with increased rates of preeclampsia and Cesarean delivery. Additionally, Veterans' infants (compared with non-Veterans') were more likely to require NICU care. Additional research is needed to explore upstream factors leading to these poorer outcomes. Current effort to coordinate VA and non-VA care for Veteran mothers is warranted.
Surgical Management of Thoracolumbar Myelopathies in Pug Dogs with Concurrent Articular Facet Dysplasia
Authors: Tauro Anna , Rose Jeremy , Rusbridge Clare , Driver Colin J.
Published: June 2019

Objectives The aim of this article is to present the outcome of vertebral stabilization using pins and polymethylmethacrylate in isolation or with concurrent spinal cord decompression for thoracolumbar myelopathies in Pug dogs with associated caudal articular process dysplasia.

Materials and Methods Retrospective case review of 14 Pug dogs with thoracolumbar myelopathy and concurrent caudal articular process dysplasia identified with magnetic resonance imaging and computed tomography. Pug dogs were graded based on the Texas Spinal Cord Injury Scale and clinical follow-up was performed immediately after surgery, at the discharge and at during the postoperative period (median 5 months). Postoperative computed tomography was performed immediately post-surgical intervention in all cases and a variable postoperative time (6 weeks or 6 months). Follow-up with telephone interview with owners was performed at a median time of 12 months postoperatively.

Results Median age of presentation was 8.5 years. In 10/14 cases, neurological improvement was observed, while urinary/faecal incontinence resolved in only two of seven affected cases. Other congenital vertebral malformations were identified in 9/14 cases.

Clinical Significance In our population of Pug dogs with thoracolumbar myelopathy and concurrent caudal articular process dysplasia, vertebral stabilization in isolation or with concurrent spinal cord decompression appeared to result in a favourable clinical outcome in the majority of patients. This technique may be favourable for myelopathies with a reportedly poor surgical outcome in this breed.
Avulsion of the Accessory-Carpal Ligaments and Sagittal Fracture of the Ulnar Carpal Bone in a Foal
Authors: Tatarniuk Dane M. , White Robin , Modesto Rolf B. , Miles Kristina G.
Published: June 2019

A 45-day-old foal presented for weight bearing lameness. Radiography revealed an abnormal radiolucent line associated with the proximal ulnar carpal bone and a separate curvilinear mineral opacity palmaromedial to the distal radial epiphysis. Computed tomography illustrated a sagittal, biarticular, non-displaced fracture of the ulnar carpal bone with small separate fragments associated with the accessory-ulnar and accessory-radial carpal ligaments. The foal was treated conservatively with rest and adjunct intra-articular hyaluronic acid. The lameness resolved within 90 days. Full range of motion of the carpus returned within 120 days following an active rehabilitation protocol. This report details avulsion of the accessory-carpal ligaments and sagittal fracture of the ulnar carpal bone secondary to presumed hyperextension injury.
What principle of difference for a truly egalitarian social democracy? Rereading Rawls after social democracy’s failures
Authors: Barata André , Cabrita Maria João
Published: June 2019

Social democracy based on welfare and the redistribution of social contributions is failing. The accumulation of wealth and the increase in inequalities are the two faces of Janus that social democracy has not been able to contain over the recent decades. In this context, it matters to discuss John Rawls’s influential difference principle. According to the maximin criterion put forth by Rawls, it does not suffice that no one becomes worse off; those who are worse off must also become better off than they are. Here, we note that the existence and growth of inequality find no opposition in the maximin rule. Despite appearances, strictly speaking it merely introduces a factor of social compensation, a sort of “assistencialism” to the victims of the greatest inequality. Even the most robust formulation of the principle of difference, according to which the greatest advantage to the less advantaged is indispensable, does not per se preclude an aggregate growth of inequalities. It seems clear that it was an egalitarian goal what Rawls had in mind in A Theory of Justice. Rawls’s critical comments on welfare capitalism must indeed not be forgotten—especially in his further explanations about the application of the principles of justice in a property-owning democracy. Here, as in liberal socialism, the dispersion of property, capital and resources prevents economic and political powers from being concentrated into the hands of a minority. However, the egalitarian aim does not strictly follow from the difference principle as stated, whether taken literally as an application of the maximin rule or inferring from its strongest formulation. A reformulation that does justice to the egalitarian aim of the principle of difference is, however, possible: namely, a degrowthist reformulation, truly requiring a degrowth in accumulation and inequalities, making explicit a brake clause that hinders the aggregate growth of inequalities. Such a degrowthist conception of the difference principle may justify some concrete rules that are able to enforce the egalitarian commitments of social democracy.
Optimized glycerol uptake from biodiesel by activated carbon prepared of Pequi (Caryocar brasiliensis Camb.) biomass residues: A novel raw material option in Brazil
Authors: Cardoso Carlos Magno Marques , Zavarize Danilo Gualberto , Vieira Glaúcia Eliza Gama
Published: June 2019

Optimized glycerol removal by activated carbon prepared with Pequi biomass residues (PBAC) was performed under the effect of different temperatures, doses of PBAC, and contact times. The experiments were arranged in a central composite design strategy following a 23 factorial configuration, totalizing 30 runs. Uptake of glycerol fluctuated between 71.3% and 96.9%, and the experimental data were better represented by a quadratic mathematical model (R2 > 0.99, p < 0.01). All independent variables and their interactions presented statistical significance (p < 0.05) on the process (temperature, p = 0.033; PBAC dosage, p < 0.0001; and contact time, p = 0.024). The interaction between increased temperatures and PBAC dosages lowered the glycerol uptake in approximately 25%. Glycerol uptake fluctuated between 85% and 87% when there was an interaction between increased temperatures and contact times. The highest glycerol uptake peak (96.9%) occurred at the lowest PBAC dosage (0.125 g), a contact time of 25 min, and a temperature of 22.5 °C. An optimized uptake of 95.6% occurred when variables mutually correlated at a temperature of 21.7 °C, a PBAC dosage of 0.29 g, and a contact time of 23.4 min. Validation experiments predicted a removal efficiency of 90.1% ± 6.64, differing in 5.5% from the optimized conditions. The values randomly predicted by the Monte Carlo simulation for glycerol removal efficiency were in close agreement with the experimental data. The lack of fit to the quadratic model was affected by the independent variables in the following magnitude order: contact time < PBAC dose < temperature.
Enhanced bandwidth, high gain, low noise transimpedance amplifier for asynchronous optical sampling systems
Authors: Yang Xue , Su Bo , Wu Yaxiong , Zhang Hongfei , Jones David R.
Published: June 2019

The methodology to correctly identify the high-bandwidth devices that are able to deliver the lowest noise voltage-amplification from receiving terahertz antenna or photodiode current sources is detailed. We further show that to achieve the lowest noise levels, amplifier input capacitance must be minimized requiring the amplifier and detection circuitry to be carefully integrated. We validate a useful technique to minimize feedback parasitic capacitance and demonstrate a transimpedance amplifier (TIA) with a peak gain of 100 MΩ, 0.5 MHz bandwidth, and a signal power to noise power ratio (SNR) of 23 dB for a 5 nA peak-current input and outline the steps required to increase this to 50 dB. Employing this TIA on a 1550 nm fiber-based terahertz asynchronous optical sampling system realizes a 700 mV, 26 dB SNR, single-scan signal from the 8 nA peak/peak antenna source and removes the requirement for an additional data acquisition trigger signal. Real time, subsecond terahertz data collection is possible at a SNR of 30 dB averaging over 16 scans.
Exchange current density model for the contact-determined current-voltage behavior of solar cells
Authors: Roe Ellis T. , Egelhofer Kira E. , Lonergan Mark C.
Published: June 2019

An analytic expression for the current–voltage [J(V)] behavior of a solar cell as limited by equilibrium exchange current densities of both carriers at both contacts is derived. The partial currents at both contacts to a generic semiconductor absorber are assumed to be linearly proportional to the excess carrier concentration at the interface with the contacts (e.g., as with Schottky-like contacts). The assumption that the quasi-Fermi levels in the absorber are approximately flat leads to an algebraic solution for the applied voltage as a function of current, which is inverted to obtain the analytic J(V) curve. The J(V) curve reveals distinct behavior associated with electrons and holes, separately, and allows for the determination of all critical performance parameters. In particular, it demonstrates how the characteristic features of the J(V) curve depend on the relative rate at which a particular carrier (electron or hole) is collected at one contact vs the other, rather than the relative rate of electron vs hole collection at a single contact. Furthermore, the model provides a unified explanation of how majority carrier extraction limitations cause nonideal J(V) behaviors such as S-shaped curves and dark/light crossover (i.e., failure of superposition). The efficacy and limitations of the model when applied to Schottky-type and doped semiconductor contacts are discussed. The work serves as a theoretical guide to scientists studying solar cells that are thought to be primarily limited by their contacts.
Light-controllable Fano resonance in azo-dye-doped all-dielectric multilayer structure
Authors: Motokura Kengo , Kang Byungjun , Fujii Minoru , Nesterenko Dmitry V. , Sekkat Zouheir , Hayashi Shinji
Published: June 2019

Active modulation of Fano resonance by light is demonstrated for an all-dielectric multilayer system containing an azo-dye-doped layer. The sample studied consists of a polystyrene layer doped with disperse red 1 (azo dye) molecules, a polyvinyl alcohol layer, and a pure polystyrene layer. In a Kretschmann attenuated-total-reflection configuration, angle-scan reflection spectra of the sample were measured with blue probe light under blue light pumping. The Fano line shape was found to change systematically depending on the intensity of the pump light. Analyses based on electromagnetic calculations of the spectra and field distributions in the layers indicate that the Fano resonance observed is generated by coupling between a broad half-leaky guided mode supported by the azo-dye-doped layer and a sharp planar waveguide mode supported by the pure polystyrene layer. The systematic changes in the Fano line shape under pump light irradiation can be well understood by a systematic decrease in light absorption in the azo-dye-doped polystyrene layer; the decrease in light absorption is due to a decrease in the extinction coefficient of the layer arising from the photoisomerization of azo dye molecules.
Improved theoretical model of two-dimensional flow field in a severely narrow circular pipe
Authors: Yao Li
Published: June 2019

Based on the two-dimensional theory of a Newtonian incompressible fluid, an improved model is proposed by combining Reynolds stresses of new disturbance factors and velocity polynomials. It is used to solve the Reynolds averaged Navier-Stokes equation for flow through a severely narrow pipe at the continuous change of the Reynolds number from laminar flow to turbulence. Both axial and radial velocity polynomials are considered in the momentum integral method. Under boundary and symmetry conditions, a first-order differential equation for a coefficient of the axial velocity with the disturbance factors is derived. Using a numerical shooting method to solve the equation, the axial distributions of pressure are obtained in the range of Reynolds numbers from 20 to 105 when the degree of stenosis equals 0.4 or 0.9. Also, under a lower Reynolds number, the velocity profiles in axial and radial directions, the streamlines at downstream and the wall shear stresses (WSS) in narrow regions are illustrated. The disturbance factors introduced can sensitively regulate the variation of inertia, pressure gradient, and viscosity term in the Reynolds averaged Navier-Stokes equation. With an increase in the Reynolds number and the parameters from 0.02 to 20 in the disturbance factors, the axial and radial velocities reverse at some narrow regions gradually, the WSS falls to below zero downstream, and the pressure drop increases in the narrow section of the pipe. It is implied that the pressure drop plays an important role in artery collapse when it is less than 40% stenosis. When the percentage of stenosis is increased to more than 40% and the Reynolds number is only 200, WSS gradually exceeds the tolerance of endothelial cells in blood vessels. The increase in pressure drop at downstream and WSS at upstream leads to the aggravation of vascular stenosis and exfoliation of the atherosclerotic plaque.
Energy-efficient data routing in cooperative UAV swarms for medical assistance after a disaster
Authors: Yang Yuanhao , Qiu Xiaoyu , Li Shenghui , Wang Junbo , Chen Wuhui , Hung Patrick C. K. , Zheng Zibin
Published: June 2019

Medical assistance is crucial to disaster management. In particular, the situation of survivors as well as the environmental information after disasters should be collected and sent back to cloud/data centers immediately for further interpretation and analysis. Recently, unmanned aerial vehicle (UAV)-aided disaster management has been considered a promising approach to enhance the efficiency of searching and rescuing survivors after a disaster, in which a group of UAVs collaborates to accomplish the search and rescue task. However, the battery capacity of UAVs is a critical shortcoming that limits their usage. Worse still, the unstable network connectivity of disaster sites could lead to high latency of data transmission from UAV to remote data centers, which could make significant challenges on real-time data collecting and processing. To solve the above problems, in this paper, we investigate an energy-efficient multihop data routing algorithm with the guarantee of quality-of-service for UAV-aided medical assistance. Specifically, we first study the data routing problem to minimize the energy consumption considering transmission rate, time delay, and life cycle of the UAV swarms. Then, we formulate the issue as a mixed-integer nonlinear programming model. Because of the Non-deterministic Polynomial-hardness of this problem, we propose a polynomial time algorithm based on a genetic algorithm to solve the problem. To achieve high efficiency, we further enhance our algorithm based on DBSCAN and adaptive techniques. Extensive experiments show that our approach can outperform the state-of-the-art methods.
Modeling of mass transfer enhancement in a magnetofluidic micromixer
Authors: Kumar Chandan , Hejazian Majid , From Christopher , Saha Suvash C. , Sauret Emilie , Gu Yuantong , Nguyen Nam-Trung
Published: June 2019

The use of magnetism for various microfluidic functions such as separation, mixing, and pumping has been attracting great interest from the research community as this concept is simple, effective, and of low cost. Magnetic control avoids common problems of active microfluidic manipulation such as heat, surface charge, and high ionic concentration. The majority of past works on micromagnetofluidic devices were experimental, and a comprehensive numerical model to simulate the fundamental transport phenomena in these devices is still lacking. The present study aims to develop a numerical model to simulate transport phenomena in microfluidic devices with ferrofluid and fluorescent dye induced by a nonuniform magnetic field. The numerical results were validated by experimental data from our previous work, indicating a significant increase in mass transfer. The model shows a reasonable agreement with experimental data for the concentration distribution of both magnetic and nonmagnetic species. Magnetoconvective secondary flow enhances the transport of nonmagnetic fluorescent dye. A subsequent parametric analysis investigated the effect of the magnetic field strength and nanoparticle size on the mass transfer process. Mass transport of the fluorescent dye is enhanced with increasing field strength and size of magnetic particles.
Simulation of NACA0015 flow separation control by burst-mode plasma actuation
Authors: Wu Bin , Gao Chao , Liu Feng , Xue Ming , Zheng Borui
Published: June 2019

Dielectric Barrier Discharge (DBD) plasma actuators can generate trains of vortices under burst mode actuation, which is very different from the wall jet flow under steady operation. To clarify the mechanism of DBD under burst mode actuation on separation control, the improved simulation model of burst-mode plasma actuation was developed and validated, and then, the flow field of NACA0015 under 12° and 14° of stall was numerically simulated and compared with the experimental result simultaneously. The results show that the DBD plasma actuator under burst mode actuation is very efficient for separation flow control, and the ability of separation flow control under F+ = 10 is more efficient than that under F+ = 0.3–5 investigated. The mechanism of burst mode actuation proposed that trains of vortices shed by burst mode actuation could enhance the momentum transfer between the boundary layer and the main flow, and the vortex of large scale shed from the leading edge could merge with the vortices of small scale shed by the DBD plasma actuator with burst mode actuation, which results in the reattachment of separated flow.
First-principles calculation of ideal-gas thermodynamic properties of long-chain molecules by R1SM approach—Application to n-alkanes
Authors: Štejfa Vojtěch , Fulem Michal , Růžička Květoslav
Published: June 2019

First-principles calculations, coupled with statistical thermodynamics, can provide ideal-gas thermodynamic properties but get complicated and less reliable with an increasing number of conformers. An approach designed for calculation of ideal-gas thermodynamic properties of long-chain molecules, R1SM, and its simplified version, sR1SM, is tested in this work by calculation of ideal-gas heat capacities and entropies for a homologous series of n-alkanes up to n-tetradecane. The R1SM approach incorporates the rigid rotor-harmonic oscillator approximation in combination with a correction for internal rotations of methyl tops using the one-dimensional hindered rotor scheme and the mixing model accounting for the population of conformers based on the Boltzmann distribution. The R1SM approach is applicable for compounds with up to hundreds of conformers, while the simplified sR1SM approach can be used for molecules with up to 105 conformers when coupled with rules for enumeration of stable conformers and estimation scheme for their energies. The obtained results for n-alkanes are compared with experimental values and previously employed computational schemes. As the conformational behavior and conformer energies are inherent parts of the proposed approaches, a thorough conformational study of n-alkanes is performed and compared with experiments and the Tasi rules for enumeration of n-alkane conformers. Finally, the standard uncertainty of the R1SM-calculated ideal-gas thermodynamic properties is estimated based on the error propagation from the used input quantities and approximations as well as on comparison to experimental values and amounts to less than 1% for both ideal-gas heat capacity and standard ideal-gas entropy.
Toward a subhourly net zero energy district design through integrated building and distribution system modeling
Authors: Doubleday Kate , Parker Andrew , Hafiz Faeza , Irwin Benjamin , Hancock Samuel , Pless Shanti , Hodge Bri-Mathias
Published: June 2019

A modeling framework integrating both building energy modeling and power system modeling is introduced for the design of net zero energy (NZE) districts for the simultaneous selection of both demand-side efficiency measures and supply-side generation technologies. A novel district control scheme is proposed for pursuing NZE on a subhourly basis while mitigating potential grid impacts such as power backfeeding and voltage violations. As a case study, Peña Station NEXT, a new 100-building, mixed-use district on a 1200-node distribution feeder in Denver, Colorado, is modeled in the integrated framework. An exhaustive scenario analysis is conducted for sizing the district's distributed energy resources, considering multiple objectives such as capital cost, net energy import, and equipment violations. When trying to achieve annual NZE, the district incurs frequent operating violations, and achieving NZE on a 15-min basis is also limited by seasonal fluctuations in photovoltaic output, illustrating the need for diverse generation or seasonal storage. As a practical compromise, both annual and 15-min district import can be reduced by ∼78% without significant violations.
Experimental and theoretical study of swept-wing boundary-layer instabilities. Unsteady crossflow instability
Authors: Borodulin V. I. , Ivanov A. V. , Kachanov Y. S. , Mischenko D. A. , Örlü R. , Hanifi A. , Hein S.
Published: June 2019

Extensive combined experimental and theoretical investigations of the linear evolution of unsteady (in general) Cross-Flow (CF) and three-dimensional (3D) Tollmien-Schlichting (TS) instability modes of 3D boundary layers developing on a swept airfoil section have been carried out. CF-instability characteristics are investigated in detail at an angle of attack of −5° when this kind of instability dominates in the laminar-turbulent transition process, while the 3D TS-instability characteristics are studied at an angle of attack of +1.5° when this kind of instability is predominant in the transition process. All experimental results are deeply processed and compared with results of calculations based on several theoretical approaches. For the first time, very good quantitative agreement of all measured and calculated stability characteristics of swept-wing boundary layers is achieved both for unsteady CF- and 3D TS-instability modes for the case of a boundary layer developing on a real swept airfoil. The first part of the present study (this paper) is devoted to the description of the case of CF-dominated transition, while the TS-dominated case will be described in detail in a subsequent second part of this investigation.
Electronic structure and superconductivity in hexagonal Li3B2 and Li2B2H phases under pressure
Authors: Hao Lingjuan , Li Xiaochuan , Zhang Yang , Luo Kun , Gao Yufei , Yuan Zhikang , Ling Feifei , Zhao Zhisheng , Yu Dongli
Published: June 2019

The relatively low-pressure layered hexagonal Li3B2 (h-Li3B2) phase under 20 GPa was identified on the basis of ab initio calculations. Inspired by the high-temperature superconductivity of metallic hydrogen, this study obtained a novel hexagonal Li2B2H (h-Li2B2H) structure by replacing Li2 with H. Contrast to h-Li3B2, h-Li2B2H may be directly synthesized by α-LiB and H2 under pressure. The two phases exhibited electronic features similar to those in MgB2 and were expected to be good superconductors. Electron–phonon coupling calculations illustrated that the layered h-Li3B2 structure is superconducting at 2 K with λ = 0.39 under 20 GPa. Moreover, h-Li2B2H was predicted to possess a large electron–phonon coupling parameter λ of approximately 0.81 and a resulting superconducting critical temperature about 28 K at 20 GPa. The introduced H in the h-Li2B2H structure had strong vibrational energy due to its light atomic mass and could enhance the energy of σ and π bonds by bonding with Li. Thus, the introduced H in the h-Li2B2H structure is important due to its enhanced electron–phonon coupling and superconducting property.
Exciton aggregation induced photoluminescence enhancement of monolayer WS2
Authors: Cheng Guanghui , Li Baikui , Zhao Chunyu , Jin Zijing , Li Hui , Lau Kei May , Wang Jiannong
Published: June 2019

Defect mediated nonradiative recombination limits the photoluminescence (PL) quantum yield of transition metal dichalcogenide monolayers (MLs). In this work, the enhancement of the PL intensity of ML WS2 is reported in a van der Waals heterostructure of WS2 ML and InGaN quantum dots (QDs) under excitation with photon energy larger than the bandgaps of both WS2 and QDs. The mechanism of this PL enhancement is due to the aggregation of excitons in WS2 ML toward the QD sites to form an interfacial bound state, which effectively mitigates the influence of defects. This exciton aggregation induced enhancement of PL intensity is more pronounced at low temperatures and under low power excitations. The lifetime and diffusion coefficient of the excitons in WS2 ML are also measured to validate the aggregation scenario.
Magnetic skyrmions in atomic thin CrI3 monolayer
Authors: Behera Aroop K. , Chowdhury Sugata , Das Suprem R.
Published: June 2019

In this letter, we report on the visualization of topologically protected spin textures, in the form of magnetic skyrmions, in recently discovered monoatomic-thin two-dimensional CrI3. By combining density functional theory and atomistic spin dynamic simulation, we demonstrate that an application of an out-of-plane electric field to the CrI3 lattice favors the formation of sub-10 nm skyrmions at 0 K temperature. The spin texture arises due to a strong correlation between magnetocrystalline anisotropy, Dzyaloshinskii-Moriya interaction, and the vertical electric field, whose shape and size could be tuned with the magnetic field. Such a finding will open avenues for atomic-scale quantum engineering and precision sensing.
A revised nuclear quadrupole moment for aluminum: Theoretical nuclear quadrupole coupling constants of aluminum compounds
Authors: Aerts Antoine , Brown Alex
Published: June 2019

The nuclear quadrupole moment of aluminum (27Al) has been re-evaluated by determining the electric field gradients at this nucleus for AlF and AlCl using the coupled cluster method with single, double, and perturbative triple excitations [CCSD(T)]/aug-cc-pwCVXZ (X = T and Q) accounting for both vibrational averaging and core–core/core–valence electron correlation and then comparing to the experimentally measured nuclear quadrupole coupling constants (NQCCs). The new recommended value is Q(27Al) = 148.2 ± 0.5 mb, which can be compared to the previous value of 146.6 ± 1 mb. Using the new value of the nuclear quadrupole moment, the accuracy is assessed for several computational approaches [i.e., Hartree–Fock, Møller–Plesset perturbation theory to the second order, quadratic configuration interaction with single and double excitations, CCSD, CCSD(T), and density functional theory (DFT) with the B3LYP, PBE0, and M06-2X functionals] and basis sets (the aug-cc-pVXZ and aug-cc-pwCVXZ families) for determining the nuclear quadruple coupling constants for AlCN, AlNC, AlSH, AlOH, and AlCCH, where experimental measurements are available. From the results at equilibrium geometries of the polyatomic molecules, it has been determined that (i) the CCSD(T)/aug-cc-pwCVXZ approach is needed to obtain results within 4% of the experimental measurements, (ii) typical DFT values are only within 10%–15% of the experimental measurements, and (iii) the aug-cc-pVXZ family of basis sets is not recommended for computing the electric field gradients at aluminum. The present results also suggest that the NQCC for AlOH should be remeasured. Using the recommended CCSD(T)/aug-cc-pwCVXZ approach, the equilibrium geometries and corresponding NQCCs for AlCH3 and AlCCCN were determined, and the NQCCs are in excellent agreement with previously reported experimental values.
Insight into the impact of atomic- and nano-scale indium distributions on the optical properties of InGaN/GaN quantum well structures grown on m-plane freestanding GaN substrates
Authors: Tang Fengzai , Zhu Tongtong , Fu Wai-Yuan , Oehler Fabrice , Zhang Siyuan , Griffiths James T. , Humphreys Colin , Martin Tomas L. , Bagot Paul A. J. , Moody Michael P. , Patra Saroj Kanta , Schulz Stefan , Dawson Philip , Church Stephen , Jacobs Janet , Oliver Rachel A.
Published: June 2019

We investigate the atomic scale structure of m-plane InGaN quantum wells grown on bulk m-plane GaN templates and reveal that as the indium content increases there is an increased tendency for nonrandom clustering of indium atoms to occur. Based on the atom probe tomography data used to reveal this clustering, we develop a k · p model that takes these features into account and links the observed nanostructure to the optical properties of the quantum wells. The calculations show that electrons and holes tend to colocalize at indium clusters. The transition energies between the electron and hole states are strongly affected by the shape and size of the clusters. Hence, clustering contributes to the very large line widths observed in the experimental low temperature photoluminescence spectra. Also, the emission from m-plane InGaN quantum wells is strongly linearly polarized. Clustering does not alter the theoretically predicted polarization properties, even when the shape of the cluster is strongly asymmetric. Overall, however, we show that the presence of clustering does impact the optical properties, illustrating the importance of careful characterization of the nanoscale structure of m-plane InGaN quantum wells and that atom probe tomography is a useful and important tool to address this problem.
Dielectric function tensor (1.5 eV to 9.0 eV), anisotropy, and band to band transitions of monoclinic
β
-(AlxGa1–x)2O3 (x ≤ 0.21) films
Authors: Hilfiker Matthew , Kilic Ufuk , Mock Alyssa , Darakchieva Vanya , Knight Sean , Korlacki Rafał , Mauze Akhil , Zhang Yuewei , Speck James , Schubert Mathias
Published: June 2019

A set of monoclinic β-(AlxGa1–x)2O3 films coherently grown by plasma-assisted molecular beam epitaxy onto (010)-oriented β-Ga2O3 substrates for compositions x ≤ 0.21 is investigated by generalized spectroscopic ellipsometry at room temperature in the spectral range of 1.5 eV–9.0 eV. We present the composition dependence of the excitonic and band to band transition energy parameters using a previously described eigendielectric summation approach for β-Ga2O3 from the study by Mock et al. All energies shift to a shorter wavelength with the increasing Al content in accordance with the much larger fundamental band to band transition energies of Al2O3 regardless of crystal symmetry. The observed increase in the lowest band to band transition energy is in excellent agreement with recent theoretical predictions. The most important observation is that charge confinement in heterostructures will strongly depend on the growth condition due to the strongly anisotropic properties of the band to band transitions.
Silica-coated metallic nanoparticle-based hierarchical super-hydrophobic surfaces fabricated by spin-coating and inverse nanotransfer printing
Authors: Zhai Shengjie , Zhao Hui
Published: June 2019

By combining spin coating and inverse nanotransfer printing, silica-coated gold nanoparticles are patterned onto polydimethylsiloxane (PDMS) superhydrophobic surfaces to form a hierarchical structure. A layer of nanoparticles is spin-coated on a flat silicon substrate serving as the stamp, which is then transferred to the raised regions of PDMS surfaces. Our inverse nanotransfer printing is in contrast to the standard nanotransfer printing, which transfers metal from the raised regions of a stamp to a flat PDMS surface. The fabricated hierarchical surface exhibits a higher contact angle and delays the Cassie-Wenzel transition during evaporation of a sessile droplet, indicating an improvement of superhydrophobicity. Finally, we demonstrate that the fabricated nanoparticle-based superhydrophobic surfaces can enhance the Raman intensity and significantly decrease the surface-enhanced Raman scattering detection limit.
Control effect of micro vortex generators on attached cavitation instability
Authors: Che Bangxiang , Chu Ning , Cao Linlin , Schmidt Steffen J. , Likhachev Dmitriy , Wu Dazhuan
Published: June 2019

The control effect of micro-vortex generators (VGs) on the instability of attached cavitation was investigated in a series of experiments. The micro-VGs, located at the leading edge of a NACA0015 hydrofoil, were used to alter the near-wall flow and control the attached cavitation dynamics. The effect of the nondimensional height of micro-VGs on the nondimensional cavity length was quantitatively evaluated by regression equations through response surface methodology. The micro-VGs increased the nondimensional cavity length. The counter-rotating streamwise vortices induced by micro-VGs had a rectifying effect on the near-wall flow and withstood the flow disturbance in the spanwise direction. Additionally, the micro-VGs partially suppressed Rayleigh–Taylor instability and Kelvin–Helmholtz instability arising from reverse flow underneath the cavity. Under a partial cavity oscillation (PCO) condition, the growth of sheet cavitation was highly two-dimensional in the spanwise direction, and the cloud cavity shedding had a strict periodicity with a smaller Strouhal number (St) than for the smooth hydrofoil. The shedding cloud cavity was captured in a single spanwise vortex core, which was advected toward the trailing edge of the hydrofoil. The transition from PCO to transitional cavity oscillation (TCO) occurred when the cavity length was larger than 0.8 of chord length. Under the TCO condition, the concave cavity closure line of sheet cavitation on the hydrofoil showed perfect symmetry and the St was nearly constant. As a result of our investigation, the micro-VGs have high potential to manipulate and control the attached cavitation dynamics.