bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and optimization of a low cost, high breakage resistance ceramic proppant special for the coal‐bed methane
Authors: Qin M. , Zhou Y. , Wang K. , Li G. , Tian Y. , Chai Y. 
Published: April 2020

AbstractA kind of low cost, high breakage resistance ceramic proppant special for exploitation of the coal‐bed methane is successfully produced. The producing conditions are optimized through orthogonal experimental design method. The breakage resistance results of the orthogonal analyses show the best condition of this kind of ceramic proppant is A4B3C3D2, which means sintering temperature of 1350 °C, manganese mineral powder content of 5 wt.%, weight ratio of 75/25 (second grade bauxite to mujie clay), and holding time of 3 h. The ceramic proppants under this very condition of A4B3C3D2 are then prepared and their phase structure and microstructure are characterized subsequently. X‐ray diffraction pattern exhibits that mullite and corundum are the main crystallographic phases. Scanning electron microscopy illustrates the A4B3C3D2 sample is with non‐porous morphology and small amount of corundum grains and liquid phase, which play the role of improving strength. It reveals the orthogonal experimental design is a feasible optimization method and the ceramic proppant made under the condition of A4B3C3D2 is a promising material for exploiting the coal‐bed methane resources.
Enhancement of the mechanical properties of EN52CrMoV4 spring steel by deep cryogenic treatment
Authors: Özden R.C. , Anik M. 
Published: April 2020

AbstractThe effect of the deep cryogenic treatment on the micro‐structure and mechanical properties (tensile strength, toughness, residual stress and fatigue strength) of the medium carbon spring steel, which is subjected to different heat treatment steps, is investigated. Deep cryogenic treatment causes spring steel to keep compressive residual stress more efficiently due to an increase in the density of the crystalline defects, retardation in the stress relief after the phase transformations and nano‐cluster carbide formations. If deep cryogenic treatment is applied before the tempering then the homogeneously distributed fine carbides form after the tempering and the grains remain relatively fine. The microstructure with homogeneously distributed fine carbides and fine grains cause spring steels to have simultaneously enhanced tensile strength, ductility and fatigue strength. If deep cryogenic treatment is applied after the conventional heat treatment (quenching+tempering), however, the coarse carbides form in the micro‐structure and the improvement in the mechanical properties of the spring steel is limited.
Preparation and film formation mechanism of an environmental‐friendly polyester/epoxy ester coil coating primer
Authors: Zhang F. , Zhang G.B. , Chen Z. , Long Z.Z. 
Published: April 2020

AbstractIn this investigation, we have prepared an environmental‐friendly waterborne coil coating primer. Waterborne saturated polyester resin and waterborne epoxy ester resin were selected as the binder resins, and methylated melamine resin and waterborne blocked isocyanate were selected as crosslinking resins. ZnMoO4, Zn3(PO4)2, Zn3Al(PO4)3, and AlH2P3O10 were selected as the anti‐corrosion pigments, and modified nano‐TiO2 particles and other fillers were also employed to further enhance the primer performance. It was found that when polyester/epoxy ester equals to 7/3; binder resins/curing agent equals to 5/1; pigments/binder resin is in range of 1.4–1.6; additives of each is in amount of 0.5 wt.%–1.5 wt.%, the obtained primer has ideal properties, such as T‐bend performance and qualified adhesion, and the salt spray resistance test can reach 360 h with the primer film thickness in range of 6 μm–7 μm after baking at 224 °C for 45 s. As to the coil coating primer film formation mechanism, Fourier transform infrared spectrum analysis indicates that both the amino resin and blocked isocyanate may react with the binder resin, and such chemical reactions can make them crosslinked to form a stereo‐network film, giving birth to a good overall performance of the obtained primer.
Power dissipation efficiency and temperature sensitivity coefficient of 2024Al/Al18B4O33w composite deformed at strain rate up to 10.0 s−1
Authors: Shi W.C. , Bo Y. , Xu F. , Gong D.M. 
Published: April 2020

AbstractPower dissipation efficiency and temperature sensitivity coefficient of 2024Al/Al18B4O33w composite under high strain rate (>0.01 s−1) at elevated temperature is studied. The composite has two instability zones with the one under low temperature and high strain rate. The power dissipation efficiency of composite from 0.08 to 0.30 is lower than that of unreinforced 2024Al alloy, showing the poorer hot forgeability of composite.
Numerical investigations on the mechanical properties of metallic hollow spheres structure with perforations under compression
Authors: Dai M. , Deng J. , Jiang H. , Dai X. , Yang F. , He X. 
Published: April 2020

AbstractThis paper numerically investigates the compressive mechanical properties of the perforated hollow spheres structures with different geometrical and physical properties. In these structures, the metallic hollow spheres are perforated regularly with several holes, which open the inner sphere volume and surface and are bonded in simple cubic, body‐centered cubic and face‐centred cubic patterns. The 5×5 cells finite element models under uniaxial compression are established by ABAQUS 6.14 software for simulation. The influence of the spheres’ spatial pattern, as well as base materials for the spheres and bonding necks on the structural mechanical properties are evaluated. By changing the wall thickness, hole diameter and bonding radius in the body‐centered cubic packing finite element model, the elastic modulus, Poisson's ratio and initial yield stress are calculated and discussed as functions of these geometrical parameters and their average densities.
Hydrogen effects in X30MnCrN16‐14 austenitic steel
Authors: Michler T. , Bruder E. , Lindner S. 
Published: April 2020

AbstractChrome‐manganese‐nitrogen austenitic steels show a technically relevant combination of proprties, i. e. high strength, high ductility, non magnetic and good corrosion resistance at costs being much lower compared to conventional chrome‐nickel austenitic stainless steels which are widely used for hydrogen applications. Hydrogen environment embrittlement of steel X30MnCrN16‐14 is investigated by slow displacement rate tensile testing in hydrogen atmosphere at 10 MPa and room temperature. Compared to the values in air, the elongation at fracture as well as the reduction of area are severely reduced in the presence of hydrogen. The microstructure is characterized in detail and the deformation modes are previously reported. It is assumed that the inherent planar deformation modes are facilitated by hydrogen resulting in premature failure.
Stabilized cyclic stress‐strain calculation for metals under multiaxial loading
Authors: Li J. , Qiu Y.Y. , Wang H.D. , Wang Z.X. 
Published: April 2020

AbstractA simple plasticity model for modeling the stabilized cyclic stress‐strain responses is developed to consider the effect of non‐proportional additional hardening. In the proposed model, the plastic modulus for uniaxial loading is extended to multiaxial loading by introducing the non‐proportionality factor and the additional hardening coefficient. The two introduced factors take into account the effects of non‐proportional additional hardening, not only on the shape of the loading path, but also on the material and its microstructure. And then, the basic Armstrong‐Frederick nonlinear hardening rule is modified to model the evolution of the back stress. The consistency condition is enforced to obtain the relationship between the back stress and plastic modulus. The proposed model requires only six material constants for estimating the stabilized responses. Comparisons between the test results (30CrNiMo8HH steel, SA 333 Gr.6 steel, and 1 %CrMoV steel) and model predictions show that the proposed model predicts relatively accurate stress responses under both proportional and non‐proportional loading paths.
A novel terpenoid class for prevention and treatment of KRAS‐driven cancers: Comprehensive analysis using in situ, in vitro, and in vivo model systems
Authors: Ganaie Arsheed A. , Siddique Hifzur R. , Sheikh Ishfaq A. , Parray Aijaz , Wang Lei , Panyam Jayanth , Villalta Peter W. , Deng Yibin , Konety Badrinath R. , Saleem Mohammad 
Published: April 2020

AbstractInhibiting the disease progression in KRAS‐driven cancers after diagnosis has been a difficult task for clinicians to manage due to the lack of effective intervention/preventive therapies. KRAS‐driven cancers depend on sustained KRAS signaling. Although developing inhibitors of KRAS signaling has proven difficult in the past, the quest for identifying newer agents has not stopped. Based on studies showing terpenoids as modulators of KRAS‐regulated downstream molecular pathways, we asked if this chemical family has an affinity of inhibiting KRAS protein activity. Using crystal structure as a bait in silico, we identified 20 terpenoids for their KRAS protein‐binding affinity. We next carried out biological validation of in silico data by employing in situ, in vitro, patient‐derived explant ex vivo, and KPC transgenic mouse models. In this report, we provide a comprehensive analysis of a lup‐20(29)‐en‐3b‐ol (lupeol) as a KRAS inhibitor. Using nucleotide exchange, isothermal titration calorimetry, differential scanning fluorimetry, and immunoprecipitation assays, we show that lupeol has the potential to reduce the guanosine diphosphate/guanosine triphosphate exchange of KRAS protein including mutant KRASG12V. Lupeol treatment inhibited the KRAS activation in KRAS‐activated cell models (NIH‐panel, colorectal, lung, and pancreatic intraepithelial neoplasia) and patient tumor explants ex vivo. Lupeol reduced the three‐dimensional growth of KRAS‐activated cells. The pharmacokinetic analysis showed the bioavailability of lupeol after consumption via oral and intraperitoneal routes in animals. Tested under prevention settings, the lupeol consumption inhibited the development of pancreatic intraepithelial neoplasia in LSL‐KRASG12D/Pdx‐cre mice (pancreatic ductal adenocarcinoma progression model). These data suggest that the selected members of the triterpene family (such as lupeol) could be exploited as clinical agents for preventing the disease progression in KRAS‐driven cancers which however warrants further investigation.
Asleep Deep Brain Stimulation of the Nucleus Ventralis Intermedius for Essential Tremor Using Indirect Targeting and Interventional Magnetic Resonance Imaging: Single‐Institution Case Series
Authors: Gravbrot Nicholas , Burket Aaron , Saranathan Manojkumar , Kasoff Willard S. 
Published: April 2020

ABSTRACTBackgroundLiterature on asleep deep brain stimulation (DBS) of the ventralis intermedius (Vim) nucleus in essential tremor is relatively sparse. Furthermore, controversy exists as to whether indirect (“consensus” or “atlas‐based”) targeting of the Vim requires physiologic adjustment for effective clinical outcomes in DBS surgery.ObjectivesThe objective of this study was to evaluate the clinical results of asleep Vim DBS using indirect coordinates and real‐time interventional magnetic resonance imaging guidance.MethodsRetrospective review of a prospectively collected database was performed to identify patients with essential tremor undergoing asleep Vim DBS using interventional magnetic resonance imaging guidance. Stereotactic and clinical outcomes were abstracted and analyzed using descriptive statistics.ResultsA total of 12 consecutive patients were identified, all of whom were available for 6‐month clinical follow‐up. Stereotactic (radial) error was 0.5 ± 0.2 mm on the left and 0.5 ± 0.3 mm on the right. Fahn‐Tolosa‐Marin tremor scores in the treated limb(s) decreased by 71.2% ± 31.0% (P = 0.0088), The Essential Tremor Rating Assessment Scale activities of daily living improved by 74.9% ± 23.7% (P < 0.0001), and The Essential Tremor Rating Assessment Scale performance improved by 64.3 ± 16.2% (P = 0.0004). Surgical complications were mild and generally transient. Stimulation‐related side effects were similar to those reported in historical series of awake Vim DBS.ConclusionsAsleep Vim DBS using indirect targeting and interventional magnetic resonance imaging–guided placement is safe and effective, with 6‐month clinical results similar to those achieved with awake placement. These data support the use of asleep surgery in essential tremor and represent a baseline for comparison with future studies using more advanced targeting techniques.
Nilotinib Fails to Prevent Synucleinopathy and Cell Loss in a Mouse Model of Multiple System Atrophy
Authors: Lopez‐Cuina Miguel , Guerin Paul A. , Canron Marie‐Hélène , Delamarre Anna , Dehay Benjamin , Bezard Erwan , Meissner Wassilios G. , Fernagut Pierre‐Olivier 
Published: April 2020

AbstractBackgroundMultiple system atrophy (MSA) is a rare, untreatable neurodegenerative disorder characterized by accumulation of α‐synuclein in oligodendroglial inclusions. As such, MSA is a synucleinopathy along with Parkinson's disease (PD) and dementia with Lewy bodies. Activation of the abelson tyrosine kinase c‐Abl leads to phosphorylation of α‐synuclein at tyrosine 39, thereby promoting its aggregation and subsequent neurodegeneration. The c‐Abl inhibitor nilotinib used for the treatment of chronic myeloid leukemia based on data collected in preclinical models of PD might interfere with pathogenic mechanisms that are relevant to PD and dementia with Lewy bodies, which motivated its assessment in an open‐label clinical trial in PD and dementia with Lewy bodies patients. The objective of this study was to assess the preclinical efficacy of nilotinib in the specific context of MSA.MethodsMice expressing human wild‐type α‐synuclein in oligodendrocytes received daily injection of nilotinib (1 or 10 mg/kg) over 12 weeks. Postmortem analysis included the assessment of c‐Abl activation, α‐synuclein burden, and dopaminergic neurodegeneration.Resultsα‐Synuclein phosphorylated at tyrosine 39 was detected in glial cytoplasmic inclusions in MSA patients. Increased activation of c‐Abl and α‐synuclein phosphorylation at tyrosine 39 were found in transgenic mice. Despite significant inhibition of c‐Abl and associated reduction of α‐synuclein phosphorylation at tyrosine 39 by 40%, nilotinib failed to reduce α‐synuclein aggregate burden (including phosphorylation at serine 129) in the striatum and cortex or to lessen neurodegeneration in the substantia nigra.ConclusionsThis preclinical study suggests that partial inhibition of c‐Abl and reduction of α‐synuclein phosphorylation at tyrosine 39 may not be a relevant target for MSA. © 2020 International Parkinson and Movement Disorder Society
NMR shielding in helium‐3 atoms modified by gaseous nitrogen and oxygen
Authors: Garbacz Piotr , Misiak Maria , Jackowski Karol 
Published: April 2020

AbstractHelium‐3 nuclear magnetic resonance (3He NMR) measurements were carried out for the gaseous mixtures of helium‐3 with pure nitrogen and synthetic air as the solvents. It was found that 3He shielding is linearly dependent on solvent density up to approx. 6 mol/L. At higher density of the gaseous solvent, the change of 3He shielding is nonlinear and especially distinct when helium‐3 atoms can interact with two O2 molecules. The interaction with paramagnetic oxygen molecules can induce two kinds of 3He shielding changes: (1) due to the isotropic Fermi contact interaction and (2) from the dipolar magnetic interaction between unpaired O2 electrons and 3He nuclear magnetic dipole moment. The two paramagnetic effects in helium‐3 shielding cannot be experimentally separated, although for such small molecular objects, they could be presumably modeled by advanced theoretical calculations.
Efficient spiral in‐out and EPI balanced steady‐state free precession cine imaging using a high‐performance 0.55T MRI
Authors: Restivo Matthew C. , Ramasawmy Rajiv , Bandettini W. Patricia , Herzka Daniel A. , Campbell‐Washburn Adrienne E. 
Published: April 2020

PurposeLow‐field MRI offers favorable physical properties for SNR‐efficient long readout acquisitions such as spiral and EPI. We used a 0.55 tesla (T) MRI system equipped with high‐performance hardware to increase the sampling duty cycle and extend the TR of balanced steady‐state free precession (bSSFP) cardiac cine acquisitions, which typically are limited by banding artifacts.MethodsWe developed a high‐efficiency spiral in‐out bSSFP acquisition, with zeroth‐ and first‐gradient moment nulling, and an EPI bSSFP acquisition for cardiac cine imaging using a contemporary MRI system modified to operate at 0.55T. Spiral in‐out and EPI bSSFP cine protocols, with TR = 8 ms, were designed to maintain both spatiotemporal resolution and breath‐hold length. Simulations, phantom imaging, and healthy volunteer imaging studies (n = 12) were performed to assess SNR and image quality using these high sampling duty‐cycle bSSFP sequences.ResultsSpiral in‐out bSSFP performed favorably at 0.55T and generated good image quality, whereas EPI bSSFP suffered motion and flow artifacts. There was no difference in ejection fraction comparing spiral in‐out with standard Cartesian imaging. Moreover, human images demonstrated a 79% ± 21% increase in myocardial SNR using spiral in‐out bSSFP and 50% ± 14% increase in SNR using EPI bSSFP as compared with the reference Cartesian acquisition. Spiral in‐out acquisitions at 0.55T recovered 69% ± 14% of the myocardial SNR at 1.5T.ConclusionEfficient bSSFP spiral in‐out provided high‐quality cardiac cine imaging and SNR recovery on a high‐performance 0.55T MRI system.
Lowering the cutoff value for increment increases the sensitivity for the diagnosis of Lambert‐Eaton myasthenic syndrome
Authors: Lipka Alexander F. , Titulaer Maarten J. , Tannemaat Martijn R. , Verschuuren Jan J.G.M. 
Published: April 2020

AbstractBackgroundIncrement of compound muscle action potential amplitude is a diagnostic hallmark of Lambert‐Eaton myasthenic syndrome (LEMS). Making a diagnosis can be challenging, therefore, a proper cutoff for abnormal increment is highly relevant for improved recognition of this rare disease.MethodsWe determined the sensitivity and specificity of 60% and 100% cutoff values in all consecutive patients who underwent increment testing in our hospital from 1999 to 2016.ResultsWe included 156 patients, 63 with LEMS and 93 without LEMS. Sensitivity of a 60% cutoff for increment testing was 77.8% (95% confidence interval 65.5%–87.3%) and 58.7% (45.6%–71.0%) for 100%. Specificity was 98.9% (94.2%–100%) and 100% (96.1%–100%) using a threshold of 60% and 100%, respectively.ConclusionsLowering the cutoff value for abnormal increment to 60% greatly increases sensitivity to diagnose LEMS without an overt loss in specificity.
Pressure‐volume analysis of rat's micturition cycles in vivo
Authors: Peng Hsien‐Yu , Lai Cheng‐Yuan , Hsieh Ming‐Chun , Ho Yu‐Cheng , Lin Tzer‐Bin 
Published: April 2020

AbstractAimsThough the pressure‐volume analysis (PVA), a method based on thermodynamics, is broadly used for assaying cardiac functions, its potential application on the physiology/pathophysiology of the urinary bladder, which processes resemble thermodynamic cycles to the heart, has not been established.MethodsCystometry recording intravesical pressure (IVP) and intravesical volume (IVV) of rhythmic voiding contractions caused by a constant saline infusion (0.04 mL/min) were carried out in forty urethane‐anesthetized female Sprague‐Dawley rats, and the PVA was established by plotting IVP against IVV.ResultsPressure‐volume points shaped coincident enclosed loops, and loop‐associated urodynamic parameters kept stable under a constant infusion rate (0.04 mL/min). Enhancing preload (by elevating infusion rates to 0.08 and 0.12 mL/min) increased the area enclosed by the loop (Apv) and shifted loops to the right and slightly upward. Augmenting afterload (by enhancing resistances using 1/4 and 1/2 urethra clamping) increased Apv and shifted loops markedly to the right and upward. Without affecting Apv, muscarine (0.01 and 0.1 mM)‐induced inotropic states shifted loop to the left and upward that was as opposed to the atropine (0.01 and 0.1 mM)‐induced anti‐inotropic state.ConclusionsNot only consistently assayed baseline bladder functions, PVA but also validly measured modified bladder functions due to altered extrinsic environment and intrinsic contractility of the bladder itself. In accompanied by cystometry, PVA could provide a clear concept about the relationship between time, pressure, and volume in the voiding activity.
Information theory for ranking and selection
Authors: Delshad Saeid , Khademi Amin 
Published: April 2020

AbstractWe study the classical ranking and selection problem, where the ultimate goal is to find the unknown best alternative in terms of the probability of correct selection or expected opportunity cost. However, this paper adopts an alternative sampling approach to achieve this goal, where sampling decisions are made with the objective of maximizing information about the unknown best alternative, or equivalently, minimizing its Shannon entropy. This adaptive learning is formulated via a Bayesian stochastic dynamic programming problem, by which several properties of the learning problem are presented, including the monotonicity of the optimal value function in an information‐seeking setting. Since the state space of the stochastic dynamic program is unbounded in the Gaussian setting, a one‐step look‐ahead approach is used to develop a policy. The proposed policy seeks to maximize the one‐step information gain about the unknown best alternative, and therefore, it is called information gradient (IG). It is also proved that the IG policy is consistent, that is, as the sampling budget grows to infinity, the IG policy finds the true best alternative almost surely. Later, a computationally efficient estimate of the proposed policy, called approximated information gradient (AIG), is introduced and in the numerical experiments its performance is tested against recent benchmarks alongside several sensitivity analyses. Results show that AIG performs competitively against other algorithms from the literature.
Optimal redesign decisions through failure rate estimates
Authors: Ge Qianru , van Jaarsveld Willem , Atan Zümbül 
Published: April 2020

AbstractTo reduce the time‐to‐market of newly developed systems, manufacturers increasingly adopt strategies where systems are brought to market while system field reliability is still uncertain. These systems are typically sold under performance‐based contracts, which incentivizes potential customers to invest in them despite reliability uncertainty. Such contracts make the manufacturer (partly) responsible for the availability of the system. Subsequently, when field reliability is lower than anticipated, the manufacturer may choose to redesign the system to avoid high contract penalties. Redesign is a costly effort which may substantially increase field reliability. Deciding when to redesign is challenging, especially because the initial failure rate estimate by the system's engineers is refined over time as failure data accrues. We propose a model that endogenizes the failure rate updating to analyze this tactical redesign decision. We study additive and multiplicative redesigns and show that the optimal policy has a control limit structure. We benchmark our optimal policy against a static counterpart numerically, and conclude that basing redesign decisions on the updated estimate of the failure rate can substantially reduce costs.