bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic MRI using model‐based deep learning and SToRM priors: MoDL‐SToRM
Authors: Biswas Sampurna , Aggarwal Hemant K. , Jacob Mathews 
Published: March 2019

Purpose
To introduce a novel framework to combine deep‐learned priors along with complementary image regularization penalties to reconstruct free breathing & ungated cardiac MRI data from highly undersampled multi‐channel measurements.
Methods
Image recovery is formulated as an optimization problem, where the cost function is the sum of data consistency term, convolutional neural network (CNN) denoising prior, and SmooThness regularization on manifolds (SToRM) prior that exploits the manifold structure of images in the dataset. An iterative algorithm, which alternates between denoizing of the image data using CNN and SToRM, and conjugate gradients (CG) step that minimizes the data consistency cost is introduced. Unrolling the iterative algorithm yields a deep network, which is trained using exemplar data.
Results
The experimental results demonstrate that the proposed framework can offer fast recovery of free breathing and ungated cardiac MRI data from less than 8.2s of acquisition time per slice. The reconstructions are comparable in image quality to SToRM reconstructions from 42s of acquisition time, offering a fivefold reduction in scan time.
Conclusions
The results show the benefit in combining deep learned CNN priors with complementary image regularization penalties. Specifically, this work demonstrates the benefit in combining the CNN prior that exploits local and population generalizable redundancies together with SToRM, which capitalizes on patient‐specific information including cardiac and respiratory patterns. The synergistic combination is facilitated by the proposed framework.
Diffusion‐weighted MRI with intravoxel incoherent motion modeling for assessment of muscle perfusion in the thigh during post‐exercise hyperemia in younger and older adults
Authors: Adelnia Fatemeh , Shardell Michelle , Bergeron Christopher M. , Fishbein Kenneth W. , Spencer Richard G. , Ferrucci Luigi , Reiter David A. 
Published: March 2019

Aging is associated with impaired endothelium‐dependent vasodilation that leads to muscle perfusion impairment and contributes to organ dysfunction. Impaired muscle perfusion may result in inadequate delivery of oxygen and nutrients during and after muscle contraction, leading to muscle damage. The ability to study the relationship between perfusion and muscle damage has been limited using traditional muscle perfusion measures, which are invasive and risky. To overcome this limitation, we optimized a diffusion‐weighted MRI sequence and validated an intravoxel incoherent motion (IVIM) analysis based on Monte Carlo simulation to study muscle perfusion impairment with aging during post‐exercise hyperemia. Simulation results demonstrated that the bias of IVIM‐derived perfusion fraction (fp) and diffusion of water molecules in extra‐vascular tissue (D) ranged from −3.3% to 14% and from −16.5% to 0.002%, respectively, in the optimized experimental condition. The dispersion in fp and D ranged from 3.2% to 9.5% and from 0.9% to 1.1%, respectively. The mid‐thigh of the left leg of four younger (21–30 year old) and four older (60–90 year old) healthy females was studied using the optimized protocol at baseline and at seven time increments occurring every 3.25 min following in‐magnet dynamic knee extension exercise performed using a MR‐compatible ergometer with a workload of 0.4 bar for 2.5 min. After exercise, both fp and D significantly increased in the rectus femoris (active muscle during exercise) but not in adductor magnus (inactive muscle), reflecting the fact that the local increase in perfusion with both groups showed a maximum value in the second post‐exercise time‐point. A significantly greater increase in perfusion from the baseline (p < 0.05) was observed in the younger group (37 ± 12.05%) compared with the older group (17.57 ± 15.92%) at the first post‐exercise measurement. This work establishes a reliable non‐invasive method that can be used to study the effects of aging on dynamic changes in muscle perfusion as they relate to important measures of physical function.
Integrase Inhibitors: After 10 Years of Experience, Is the Best Yet to Come?
Authors: Brooks Kristina M. , Sherman Elizabeth M. , Egelund Eric F. , Brotherton Amy , Durham Spencer , Badowski Melissa E. , Cluck David B. 
Published: March 2019

The era of the integrase strand transfer inhibitors (INSTIs) for the treatment of human immunodeficiency virus (HIV) infection began with raltegravir in 2007. Since that time, several other INSTIs have been introduced including elvitegravir, dolutegravir, and, most recently, bictegravir, that have shown great utility as part of antiretroviral regimens in both treatment‐naive and treatment‐experienced patients. At present, antiretroviral guidelines fully endorse the INSTI class as part of all first‐line treatment regimens. After 10 years of experience with INSTIs, newer agents are on the horizon such as cabotegravir and MK‐2048 for potential use as either HIV pre‐exposure prophylaxis or maintenance therapy. This review provides a brief overview of the INSTI class including agents currently available and those still in development, reviews available data from both completed and ongoing clinical trials, and outlines simplification strategies using INSTIs.
Adjustable‐Function Beam Shaping Methods
Authors: Brodsky Alexander , Kaplan Natan , Liebl Stefan , Franke Rainer 
Published: March 2019

AbstractLaser welding is used in a wide range of industrial applications including automotive, aerospace, semiconductors, electronics, medical, power, defense, and others. The raw laser beam is not the optimal shape for many industrial applications in general and especially in the field of welding, brazing, soldering, and other similar processes. Compared to other laser material processing applications, these processes stand out in terms of the required laser power (multi kW) and the highly multimode beams often used. A process‐specific tailored laser intensity distribution can improve throughput, seam height, strength, and the edge smoothness of the joints.
Numerical Simulation and Unsteady Combustion Model of AP/HTPB Propellant under Depressurization by Rotation
Authors: Ye Zhen‐W. , Yu Yong‐G. 
Published: March 2019

AbstractIn order to study micro‐scale combustion characteristics of base‐bleed propellant ammonium perchlorate/hydroxyl terminated polybutadiene (AP/HTPB) under rotation condition, a two‐dimensional unsteady rotating combustion model of periodic sandwich model of AP/HTPB was established. In the gas phase, a two‐step overall reaction was used to couple the gas‐solid boundary layer, the rotational momentum was fitted and the numerical simulation comparative analysis under the initial combustion pressure of 0.1 MPa–5 MPa and the rotation velocity of 0–10 800 r min−1 was experimented. The results show that under the conditions of an initial combustion pressure of 3.5 MPa, a depressurization rate of 1000 MPa s−1 and a rotation velocity of 10 200 r min−1, the formation of a narrow diffusion‐controlled chemical reaction zone appears in the initial stage of depressurization. When the combustion pressure drops to about 0.88 MPa, the flame shows dual characteristics: diffusion‐controlled and premixed combustion. When the pressure dropped to 0.1 MPa, the flame is premixed combustion. The steady combustion process at different combustion pressures and different rotational velocities was analyzed numerically. The results show that there is a linear positive correlation between the flame deflection angle and the pressure. When the rotation velocity is lower than 10 000 r min−1, the deflection angle of the gas flame increases linearly with the rotation velocity. However, when the rotation velocity is higher than 10 000 r min−1, the deflection angle and the rotation velocity of the gas flame increase exponentially. The trend of the average Reynolds number of the combustion surface is basically the same as that of the deflection angle of the gas flame. Therefore, the average Reynolds number of the combustion surface can be used to describe the influence of rotation and pressure on the deflection angle of the gas phase flame.
Combustion of HTPB Based Solid Fuels Containing Metals and Metal Hydrides with Nitrous Oxide
Authors: Young Gregory , Risha Grant A. , Connell Terrence L. , Yetter Richard A. 
Published: March 2019

AbstractAn experimental investigation of the combustion characteristics of HTPB‐based solid fuels containing aluminum and aluminum hydride has been conducted. Aluminum is commonly used as a fuel supplement in solid rocket propellants because of its ability to increase the specific impulse of a propellant. Similarly, aluminum hydride, or alane, is another attractive fuel supplement because it can significantly (∼7–8 %) increase specific impulse even beyond that of aluminum. In this study, the regression rates of a baseline fuel (pure HTPB) were compared with that of fuels containing either aluminum or alane as additives using a counterflow combustion experiment with nitrous oxide (N2O) as the oxidizer. The additives were investigated in concentrations of 10, 20, and 40 % by weight of the fuels. The addition of aluminum at all loadings resullted in a decrease in the regression rate relative to the baseline, whereas the addition of alane resulted in at worst similar regression rates and at best (highest loading) approximately a 20 % increase in regression rate. The decomposition behavior of selected fuels was analyzed using traditional thermal analysis techniques; thermal gravimetric analysis and differential scanning calorimetry
Domain‐specific virtual processors as a portable programming and execution model for parallel computational workloads on modern heterogeneous high‐performance computing architectures
Authors: Lyakh Dmitry I. 
Published: March 2019

AbstractWe advocate domain‐specific virtual processors (DSVP) as a portability layer for expressing and executing domain‐specific computational workloads on modern heterogeneous HPC architectures, with applications in quantum chemistry. Specifically, in this article we extend, generalize and better formalize the concept of a domain‐specific virtual processor as applied to scientific high‐performance computing. In particular, we introduce a system‐wide recursive (hierarchical) hardware encapsulation mechanism into the DSVP architecture and specify a concrete microarchitectural design of an abstract DSVP from which specialized DSVP implementations can be derived for specific scientific domains. Subsequently, we demonstrate, an example of a domain‐specific virtual processor specialized to numerical tensor algebra workloads, which is implemented in the ExaTENSOR library developed by the author with a primary focus on the quantum many‐body computational workloads on large‐scale GPU‐accelerated HPC platforms.
Double‐hole‐mediated coupling of anionic dopants in perovskite NaNbO3 for efficient solar water splitting
Authors: Wang Jiajun , Teng Jing , Pu Lizhi , Huang Jing , Wang Ying , Li Qunxiang 
Published: March 2019

AbstractDoping is an effective strategy to improve the photocatalytic performances of semiconductor photocatalyst for water splitting. In this work, we perform extensive hybrid density functional calculations to investigate perovskite NaNbO3 with anionic monodoping with N, C, P, and S dopants as well as with (N + N), (C + S), and (N + P) codoping pairs. Theoretical results clearly reveal that the band structures of NaNbO3 can be effectively tailored by introducing double‐hole‐mediated coupling of anion‐anion pairs. Compared with the monodoping cases, the anion‐anion codoped NaNbO3 systems not only have substantially narrowed band gaps, but also can eliminate the unoccupied localized states appearing above the Fermi level, which are disastrous for photocatalysis as they may trap the photogenerated carriers. Optical absorption curves further convince that the codoped NaNbO3 can effectively harvest visible light. The band edge positions with respect to the redox potentials of water demonstrate that the (N + N) codoped NaNbO3 are desirable for efficient solar water splitting.
Identification of new interferences leached from plastic microcentrifuge tubes in electrospray ionization mass spectrometry
Authors: Chai Yunfeng , Chen Hongping , Gao Guanwei , Liu Xin , Lu Chengyin 
Published: March 2019

RationaleThe incredible sensitivity of the modern mass spectrometry instrument enables scientists to detect a large number of molecules ranging from small organic compounds to biological macromolecules. However, the same sensitivity often throws up challenges with respect to background interferences and contaminants. The identification and source of these contaminants is very important for reducing background contamination and ensuring the accuracy of the analysis results.MethodsThe interfering compounds were analyzed by high‐performance liquid chromatography coupled with a hybrid quadrupole‐orbitrap mass spectrometer. The structural analysis was conducted by obtaining the accurate masses of precursors and their fragment ions. The retention time and MS/MS spectrum of one of the interfering compounds (N‐lauryldiethanolamine) were compared with an authentic standard to reach an unequivocal structural assignment.ResultsThe interferences (m/z 274 and 318 in positive mode) were observed during the analysis of herbicides in tea samples by electrospray ionization mass spectrometry (ESI‐MS). Their structures were identified to be N‐lauryldiethanolamine and N‐(2‐hydroxyethyl)‐N‐(2‐(2‐hydroxyethoxy)ethyl)dodecylamine by fragmentation interpretation and further confirmed by a standard compound. These interferences were found to be leached from the plastic microcentrifuge tubes used during sample pretreatment. The plastic tubes from two of the five suppliers tested were found to contain these two interferences.ConclusionsIn this work, we presented an example about the observation, identification and source of interferences in ESI‐MS. The N‐lauryldiethanolamine and other ethoxylated aliphatic alkylamines are common plastic antistatic agents. They possess high proton affinity so that they show a strong response in ESI positive mode. In order to avoid their interference during mass spectrometric analysis we need to choose plastic tubes (or other plastic materials) that do not contain such antistatic agents.
Output feedback preview control for polytopic uncertain discrete‐time systems with time‐varying delay
Authors: Li Li , Yuan Yuanlong 
Published: March 2019

SummaryThis paper considers the preview tracking control problem of polytopic uncertain discrete‐time systems with a time‐varying delay subject to a previewable reference signal. First, a model transformation is employed and a discrete‐time system with a time‐invariant delay and an external disturbance is obtained. The difference operator method can be extended to derive an augmented error system that includes future information on the reference signal. Then, a previewable reference signal is fully utilized through reformulation of the output equation while considering the output feedback. Based on the small gain theorem, a static output feedback controller with preview actions is designed such that the output can asymptotically track the reference signal. Finally, numerical simulation examples also illustrate the superiority of the desired preview controller for the uncertain system in the paper.
Mechanism of Direct Electrophilic Aromatic Amination: an Electrophile is Found by Quantum‐Chemical Study
Authors: Stankevich Ksenia S. , Bondarev Alexander A. , Lavrinenko Anastasia K. , Filimonov Victor D. 
Published: March 2019

AbstractDirect amination is an extremely valuable reaction, allowing for the one‐step preparation of aromatic amines. However, its mechanism was poorly studied. Here, for the first time, using quantum chemical calculations, we have shown that direct amination of arenes by hydrazoic acid follows the classical SEAr mechanism with aminodiazonium cation H2N3+ as electrophile. The peculiarity of H2N3+ electronic structure has been described using our novel method for tracing the molecular orbitals. The located stationary points and transition states allowed us to define direct amination as SEAr reaction, which rate is determined by early transition state between π‐ and σ‐complexes. Considering the calculated reaction constant ρ and an early transition state, we placed direct amination of arenes by HN3 somewhere in‐between nitration and halogenations. Our results explain the accumulated experimental data and open a prospect for the development of the new aminating agents working in milder conditions.
A Supramolecular Gel to Reduce Tool Wear and Protect Surfaces during Metalworking
Authors: Chowdhury Srayoshi Roy , Chidambaram C. T.  , Podder Debasish , Sasmal Supriya , Debnath Mintu , Kumaraswamidhas LA , Dutta Suman , Haldar Debasish 
Published: March 2019

AbstractMetalworking includes creating tiny designer parts, fitting of the parts and assemblies to large scale structures by forming, cutting, and joining. The processes produce lots of dust, pollutants, noise and heat. A metalworking supramolecular gel has been developed to improve workpiece quality, to reduce tool wear and protect newly cut metal surface. An efficient NDI‐based gelator for silicon oil has been synthesized and investigated. From X‐ray single crystal studies, the dodecyl groups adopt all anti conformation on both side of the diimide and the compound self‐assembled to form supramolecular sheet‐like structure. The compound successfully imbololized silicon oil and formed a soft gel at 4 wt% (w/v). From mechanical response, storage modulus (G’) was greater than loss modulus (G”) and did not cross each other over the entire range of angular frequency, which indicates that the gel is elastic in nature. The FE‐SEM images showed that the gel is made of entangled fibers. Further the gel was used during metal cutting and grinding to reduce tool wear, and was found to prevent the sparking, absorb the dust and finally release the silicon oil to protect newly cut metal surface.
In Situ Wrapping SiO with Carbon Nanotubes as Anode Material for High‐Performance Li–Ion Batteries
Authors: Li Jianbin , Wang Lei , Liu Fangming , Liu Wenjing , Luo Caikun , Liao Yingling , Li Xuan , Qu Meizhen , Wan Qi , Peng Gongchang 
Published: March 2019

AbstractSilicon‐based material as lithium‐ion anodes has attracted huge attention owing to their ultrahigh capacity. However, they usually undergo severe volume expansion over the repeated lithiation/delithiation processes and have low electronic conductivity, leading to the inferior cycling stability and the poor rate capability. Here, an in‐situ growth of carbon nanotubes (CNTs) on the surface of SiO composite was prepared and then encapsulated by the amorphous carbon derived from high softening point pitch. SEM and TEM studies show that SiO was firmly wrapped with CNTs and well coated with the amorphous carbon. Meanwhile, nitrogen adsorption‐desorption measurement indicated the prepared composite SiO@CNTs/C was hierarchical pore structure, which can shorten the lithium‐ion transport pathway and enhance the structural stability. The prepared SiO@CNTs/C exhibited an excellent long‐term cycling stability (a high reversible specific capacity of 821.7 mAh g−1, and a high capacity retention of 95.9% to the 3rd cycle after 200 cycles), and prominent rate capacity, indicating the great potential of SiO@CNTs/C anode for practical application.
Seroprevalence of Q fever in cattle, sheep and goats in the Volta region of Ghana
Authors: Johnson Sherry A. M. , Kaneene John B. , Asare‐Dompreh Kweku , Tasiame William , Mensah Ivy G. , Afakye Kofi , Simpson Shirley V. , Addo Kwasi 
Published: March 2019

AbstractQ fever is a zoonotic disease caused by Coxiella burnetii, a causative agent of abortion in livestock and febrile illness in humans. Outbreaks of human cases of Q fever have been reported in Australia and the Netherlands, which was linked to abortions in goat and sheep farms. In Ghana, information on Q fever in both livestock and humans is scanty. This study sought to determine the seroprevalence of Q fever in livestock in the Tongu area of the Volta region of Ghana. It was a cross sectional study with blood sampled from 204 cattle, 158 sheep and 100 goats. An indirect ELISA test was performed to detect Q fever antibodies in the serum of livestock. A total of 20 farms were sampled across the municipalities and an overall prevalence of Q fever was 21.6%. Specie‐specific prevalence was 28.4% (45/158) for sheep, 21.7% (45/204) for cattle and 10% (10/100) for goats. Abortions were reported on all the farms sampled and most farmers lived in close proximity to the farms sampled. Q fever is prevalent in the North Tongu area and requires the attention of the veterinary and health authorities, using the One‐ Health approach in order to control its occurrence and save lives.
Participation of wind power producers in day‐ahead and balancing markets: An overview and a simulation‐based study
Authors: Algarvio Hugo , Lopes Fernando , Couto António , Estanqueiro Ana 
Published: March 2019

At present, a harmonized pan‐European electricity market (EM) is a close reality. While in day‐ahead markets (DAMs) the harmonization is at an advanced stage, in balancing markets (BMs) still exist some challenging issues, notably the remuneration of imbalances: some countries have simple and clear methods, but others consider complex methods that are not appealing to the participation of variable renewable energy (VRE). The participation of VRE in BMs is technically feasible, although with some restrictions to guarantee security and stability. Thus the economic attractiveness of these markets should be increased in order to enable full integration of VRE without feed‐in‐tariffs or other incentives. This article presents an overview of EMs, focusing on European BMs, and also investigates the benefits of the participation of wind power producers (WPPs) in BMs at both economic and technical levels. In particular, the article presents a new strategy allowing WPPs to bid in BMs. It also presents a study involving four scenarios, where WPPs participate in: (a) the DAM (baseline scenario), (b) the DAM and the automatic‐activated frequency restoration reserve market, (c) the DAM and the manually activated FRR (mFRR) market, and (d) the DAM and a 15‐min mFRR market. The simulations are performed with the agent‐based system MATREM (for Multi‐Agent TRading in EMs). For the last scenario, the results indicate an increase around 6% in the wind energy value to the market, a decrease of 12% in the total reserve used, and a decrease around 16% in the costs from the BM.This article is categorized under:

Wind Power > Systems and Infrastructure
Wind Power > Economics and Policy
Energy Systems Analysis > Economics and Policy
Are we born equal: a study of intergenerational income mobility in China
Authors: Jin Mengjie , Bai Xuemei , Li Kevin X , Shi Wenming 
Published: March 2019

AbstractStudies show that the gain from China's remarkable growth of the past 35 years has not been evenly shared, especially through the intergenerational transmission of income. To address this concern, we use data from China Health and Nutrition Survey and find the intergenerational income elasticity to be 0.466 in 2011, which suggests that sons’ incomes are affected by their fathers’ economic statuses to a large extent. A cross-country comparison indicates that the degree of generational income mobility in China is lower than that in many developed nations. Meanwhile, by investigating possible transmission channels, we find that the fathers’ investments in the sons’ education and occupation play substantial roles in intergenerational transmission of income. The results not only demonstrate the trends in intergenerational income mobility in China, but also identify the most likely transmission channels, which is of great importance to improving social equality.