bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the Optimal Damping Coefficient in the Continuous Contact Model
Authors: Poursina Mohammad , Nikravesh Parviz E. 
Published: May 2020

AbstractThis paper presents an analytical formula to characterize the damping coefficient as a function of system's parameters in a continuous force model of impact. The contact force element consists of a linear damper which is in a parallel connection to a spring with Hertz force-deformation characteristic. Unlike the existing models in which the separation condition is assumed to be at the time at which both zero penetration (deformation) and zero force occur, in this study, only zero contact force is considered as the separation condition. To ensure that the continuous contact model obtains the desired restitution, an optimization process is performed to find the equivalent damping coefficient. The analytical and numerical investigations show that the resulting damping coefficient can be expressed as a function of system's parameters such as the effective mass, penetration speed at the start of the impact, Hertz spring constant, and the coefficient of restitution.
Liquid Flow Forced Convection in Rectangular Microchannels With Nonuniform Heating: Toward Analytical Modeling of Hotspots
Authors: Azari Milad , Sadeghi Arman , Dejam Morteza 
Published: May 2020

Abstract
The heat generated by microprocessors has an extremely nonuniform spatial distribution with hotspots that have heat fluxes several times larger than the background flux. Hence, for an accurate design of microchannel heat sinks used for cooling of micro-electronic devices, models are required that can take such a nonuniform distribution of wall heat flux into account. In this study, analytical solutions are obtained for hydrodynamically fully developed but thermally developing mixed electro-osmotic and pressure-driven (PD) flow in a rectangular microchannel with a peripherally uniform but axially nonuniform distribution of the wall heat flux. It is assumed that the heat flux is applied over a finite length, to mimic a physically more realistic situation, and the Péclet number is small so that lateral temperature variations are negligible as compared to the axial variations of temperature. By comparing the results with those of full numerical simulations for exponential (EHF), sinusoidal (SHF), and stepwise (STHF) distributions of wall heat flux, it is demonstrated that the solutions obtained are accurate up to a Péclet number of 10. Fortunately, this value is larger than the maximum Péclet number of electro-osmotic microflows. Furthermore, it is shown that smoother distributions of wall heat flux give rise to higher heat transfer rates. The model developed in this study can pave the way for modeling of hotspots in more complicated microfluidic devices.
Effects of Crack Closure on the Fatigue Crack Growth Rates of Ferritic Steels Subjected to Severe Reversing Loads
Authors: Azuma Kisaburo , Hidaka Shinjiro , Yamazaki Yasuhiro 
Published: May 2020

Abstract
Low-alloy steels are extensively used in pressure boundary components of nuclear power plants. The structural integrity of the components made of low-alloy steels can be evaluated by the flaw evaluation procedure provided by Section XI of the ASME Boiler and Pressure Vessel Code. According to the Code, the stress intensity factor range ΔK can be used to determine the fatigue crack growth rates of the material. However, it has been reported that the fatigue crack growth rate under severe reversing loads is also strongly influenced by crack closure behavior. This paper discusses the relation between applied stresses and the fatigue crack growth rate for cracks in low-alloy steels exposed to air. Compressive-tensile cyclic loadings are applied to center-notched plates to obtain the fatigue crack growth curves. The test data demonstrate that effective stress intensity factor range predicted by our closure model described the crack growth property more accurately. A comparison among crack closure models indicates that our crack closure model is suitable to predict the crack growth rates when low constraint conditions are assumed at the crack tip due to severe reversing loads.
Habenula lesions improve glucose metabolism in rats with type 2 diabetes by increasing insulin sensitivity and inhibiting gluconeogenesis
Authors: Qu Peng , Wang Yachun , Liu Lei , Qi Mengmeng , Sun Yimeng , Zheng Siyang , Xu Zichen , Liu Changhong , Bai Xiaoyan , Zhang Qinggao , Yang Limin 
Published: May 2020

IntroductionThe habenular nucleus (Hb), a famous relay station in the midbrain, is vital for controlling many physiological functions of vertebrates. The role of Hb in the pathogenesis of depression has been thoroughly studied, but whether it functions in the pathogenesis of diabetes remains unknown. In this study, we found that Hb lesions could improve glucose metabolism in type 2 diabetes mellitus (T2DM) by inhibiting the peripheral sympathetic nervous system and hepatic glucose production.Research design and methodsT2DM rats were induced by a high-carbohydrate and fat diet combined with streptozotocin. Electrical lesion method was applied to suppress the function of Hb. Serum and tissue samples of rats in the control group, T2DM group, sham group, and Hb lesion group were detected by ELISA, western blotting, and biochemical methods.ResultsCompared with the sham group, the expression levels of AMPK phosphorylation and insulin receptor (IR) were significantly increased, whereas glucose-6-phosphatase and phosphoenolpyruvate carboxylated kinase were reduced in the liver of the Hb lesion group. In the glucose tolerance test and pyruvate tolerance test, the lesion group showed stronger glucose tolerance and lower hepatic gluconeogenesis than the sham. These results suggest that Hb lesions not only effectively increase insulin sensitivity and improve insulin resistance but also inhibit gluconeogenesis in T2DM rats. Moreover, Hb lesions increase the expression of brain-derived neurotrophic factor, tropomyosin receptor kinase B, glucocorticoid receptor, and IR in the hippocampus. In this study, we also found that Hb lesions increase the content of acetylcholine in the adrenal glands and reduce the content of epinephrine in both the adrenal glands and the liver, which may be the main reason for the Hb lesions to regulate glucose metabolism in the liver.ConclusionHb is an important neuroanatomical target for the regulation of glucose metabolism in the central nervous system of diabetic rats.
Scrutinizing various phenomenological interactions in the context of holographic Ricci dark energy models
Authors: Sadri Ehsan , Khurshudyan Martiros , Zeng Ding-fang 
Published: May 2020

AbstractIn this paper, we examine two types of interacting holographic dark energy model using Pantheon supernova data, BAO BOSS DR12, CMB Planck 2015, fgas (gas mass fraction) and SZ/Xray (Sunyaev–Zeldovich effect and X-ray emission) data from galaxy clusters (GC). In particular, we considered the Holographic Ricci dark energy and Extended holographic Ricci dark energy models. During this analysis, we considered seven types of phenomenological interaction terms (three linear and four non-linear) $$Q_1=3Hb\left( \rho _{D}+\rho _m\right) $$Q1=3HbρD+ρm, $$Q_2=3Hb\rho _{D}$$Q2=3HbρD, $$Q_3=3Hb\rho _{m}$$Q3=3Hbρm, $$Q_4=3Hb\left( \rho _{D}+\frac{\rho _{D}^2}{\rho _{D}+\rho _m}\right) $$Q4=3HbρD+ρD2ρD+ρm, $$Q_5=3Hb\left( \rho _{m}+\frac{\rho _{m}^2}{\rho _{D}+\rho _m}\right) $$Q5=3Hbρm+ρm2ρD+ρm, $$Q_6=3Hb\left( \rho _{D}+\rho _{m}+\frac{\rho _{D}^2}{\rho _{D}+\rho _m}\right) $$Q6=3HbρD+ρm+ρD2ρD+ρm, $$Q_7=3Hb\Big (\rho _{D}+\rho _{m}+\frac{\rho _{m}^2}{\rho _{D}+\rho _m}\Big )$$Q7=3Hb(ρD+ρm+ρm2ρD+ρm) respectively. To find the best model we apply Bayesian Inference (BI) and use the $$\Lambda $$ΛCDM as the referring model for comparison. Using the Bayesian Evidence model selection method we note that the $$Q_3$$Q3 and $$Q_5$$Q5 interaction terms are favored by observational data among the other ones. The obtained results also demonstrated that the evidence from the Bayesian inference method against the considered types of holographic Ricci dark energy model is strong since the $$\Lambda $$ΛCDM is considered as the reference model and also the $$\Lambda $$ΛCDM is preferred over the models. We also observed that the values of the deceleration parameter and the transition redshift for all models are compatible with the latest observational data and Planck 2015. In addition, we studied the jerk parameter for all models. Using our modified CAMB code, we observed that the interacting models suppress the CMB spectrum at low multipoles and enhances the acoustic peaks.
Superradiance of a global monopole in Reissner–Nordström(–AdS) space-time
Authors: Seçuk M. Haluk , Delice Özgür 
Published: May 2020

AbstractIn this article, the behavior of a charged and massive scalar field around a global monopole swallowed by a Reissner–Nordström–Anti-de Sitter (RN–AdS) black hole is investigated by considering the Klein–Gordon equation in this geometry. The superradiance phenomenon and instability behavior of the black hole against charged scalar perturbations are studied for both an RN–AdS case and also for an RN black hole surrounded by a reflective mirror, i.e., the black hole bomb case. The effects of the monopole on these cases are discussed analytically and also with the help of several graphs in detail. The monopole charge affects the superradiance threshold frequency and also effects the instability time scale for both cases. The existence of global monopole makes these black holes more stable against superradiance instability.
Network Efficiency Mediates the Relationship Between Vascular Burden and Cognitive Impairment
Authors: Shen Jun , Tozer Daniel J. , Markus Hugh S. , Tay Jonathan 
Published: May 2020

Background and Purpose—
Cerebrovascular disease contributes to age-related cognitive decline, but the mechanisms underlying this phenomenon remain incompletely understood. We hypothesized that vascular risk factors would lead to cognitive impairment through the disruption of brain white matter network efficiency.

Methods—
Participants were 19 346 neurologically healthy individuals from UK Biobank that underwent diffusion MRI and cognitive testing (mean age=62.6). Global efficiency, a measure of network integration, was calculated from white matter networks constructed using deterministic diffusion tractography. First, we determined whether demographics (age, sex, ethnicity, socioeconomic status, and education), vascular risk factors (hypertension, hypercholesterolemia, diabetes mellitus, smoking, body mass index), and white matter hyperintensities were related to global efficiency using multivariate linear regression. Next, we used structural equation modeling to model a multiple regression. The dependent variable was a latent cognition variable using all cognitive data, while independent variables were a latent factor including all vascular risk factors (vascular burden), demographic variables, white matter hyperintensities, and global efficiency. Finally, we used mediation analysis to determine whether global efficiency explained the relationship between vascular burden and cognition.

Results—

Hypertension and diabetes mellitus were consistently associated with reduced global efficiency even after controlling for white matter hyperintensities. Structural equation models revealed that vascular burden was associated with cognition (
P
=0.023), but not after adding global efficiency to the model (
P
=0.09), suggesting a mediation effect. Mediation analysis revealed a significant indirect effect of global efficiency on cognition through vascular burden (
P
<0.001), suggesting a partial mediation effect.

Conclusions—
Vascular burden is associated with reduced global efficiency and cognitive impairment in the general population. Network efficiency partially mediates the relationship between vascular burden and cognition. This suggests that treating specific risk factors may prevent reductions in brain network efficiency and preserve cognitive functioning in the aging population.
Original and Modified Graeb Score Correlation With Intraventricular Hemorrhage and Clinical Outcome Prediction in Hyperacute Intracranial Hemorrhage
Authors: Bisson Daniel-Alexandre , Flaherty Mathew L. , Shatil Anwar S. , Gladstone David , Dowlatshahi Dar , Carrozzella Janice , Zhang Liying , Hill Michael D. , Demchuck Andrew , Aviv Richard I. ,   for the STOP-IT and SPOTLIGHT Investigators*, Thorpe Kevin E. , Khoury Jane C. , Sucharew Heidi J. , Al-Ajlan Fahad , Butcher Ken , Gubitz Gord , DeMasi Stephanie , Hall Judith , Gregg David , Mamdani Muhammad , Shamy Michel , Swartz Richard H. , Martin del Campo C. , Cucchiara Brett , Panagos Peter , Goldstein Joshua N. , Jauch Edward C. , Broderick Joseph P. 
Published: May 2020

Background and Purpose—
The Graeb score is a visual rating scale of intraventricular hemorrhage (IVH) on noncontrast head CT. Little data exist in the hyperacute (<6 hour) period for reliability and predictive value of the modified Graeb Score (mGS) or the original Graeb Score (oGS) for clinical outcomes or their correlation with quantitative IVH volumes.

Methods—
A retrospective analysis of multicenter prospective intracranial hemorrhage study was performed. oGS and mGS inter-observer agreement and IVH volume correlation on the baseline noncontrast head CT were calculated by intraclass correlation coefficient and Pearson coefficient respectively. Predictors of poor outcome (modified Rankin Scale scores ≥4) at 3 months were identified using a backward stepwise selection multivariable analysis. oGS and mGS performance for modified Rankin Scale scores ≥4 was determined by receiver operating characteristic analysis.

Results—

One hundred forty-one patients (65±12 years) with median (interquartile range) time to CT of 82.5 (70.3–157.5) minutes were included. IVH was observed in 43 (30%) patients. Inter-observer agreement was excellent for both oGS (intraclass correlation coefficient, 0.90 [95% CI, 0.80–0.95]) and mGS (intraclass correlation coefficient, 0.97 [95% CI, 0.84–0.99]). mGS (R=0.79;
P
<0.01) correlated better than oGS (R=0.71;
P
<0.01) with IVH volumes (
P
=0.02). Models of thresholded oGS and mGS were not different from a model of planimetric baseline intracranial hemorrhage and IVH volume for poor outcome prediction. Area under the curves were 0.70, 0.73, and 0.72, respectively.

Conclusions—
Excellent correlation for oGS and mGS with IVH volume was seen. Thresholded oGS and mGS are reasonable surrogates for planimetric IVH volume for hyperacute intracranial hemorrhage studies.
Association of Genetic Variants With Moyamoya Disease in 13 000 Individuals
Authors: Wang Xiaotong , Wang Yue , Nie Fangfang , Li Qian , Zhang Kaili , Liu Mengwei , Yang Luping , Zhang Qian , Liu Shan , Zeng Fanxin , Shang Mengke , Liang Man , Yang Yuetian , Liu Xiuping , Liu Wanyang 
Published: May 2020

Background and Purpose—
A growing body of evidence indicates genetic components play critical roles in moyamoya disease (MMD). Firm conclusions from studies of this disease have been stymied by small sample sizes and a lack of replicative results. This meta-analysis was conducted to determine whether these genetic polymorphisms are associated with MMD.

Methods—

PubMed, Google Scholar, Embase, Wanfang, Web of Science, and China National Knowledge Infrastructure databases were used to identify potentially relevant studies published until January 2020. The Review Manager 5.2 and Stata 15.0 software programs were used to perform the statistical analysis. Heterogeneity was assessed using the Cochran
Q
test and quantified using the
I

2

test.

Results—

Four thousand seven hundred eleven MMD cases and 8704 controls in 24 studies were included, evaluating 7 polymorphisms in 6 genes. The fixed-effect odds ratios (95% CI) in allelic model of
MMP-2
rs243865 were 0.60 (0.41–0.88) (
P
=0.008). In the country-based subgroup analysis, the fixed-effect odds ratios (95% CI) of
RNF213
rs112735431 in allelic model were China, 39.74 (26.63–59.31), Japan, 74.65 (42.79–130.24) and Korea, 50.04 (28.83–86.88; all
P
<0.00001). In the sensitivity analysis, the fixed-effect odds ratios (95% CI) of allelic and dominant models were the
RNF213
rs148731719 variant, 2.17 (1.36–3.48;
P
=0.001), 2.20 (1.35–3.61;
P
=0.002), the
TIMP-2
rs8179090 variant, 0.33 (0.25–0.43;
P
<0.00001), 0.88 (0.65–1.21;
P
=0.440) and the
MMP-3
rs3025058 variant, 0.61 (0.47–0.79;
P
=0.0002), 0.55 (0.41–0.75;
P
=0.0001), respectively.

Conclusions—

RNF213
rs112735431 and rs148731719 were positively, and
TIMP-2
rs8179090,
MMP-2
rs243865, and
MMP-3
rs3025058 were inversely associated with MMD using multiple pathophysiologic pathways. Studies in larger population should be conducted to clarify whether and how these variants are associated with MMD.
Dose and setting of rehabilitation received after stroke in Queensland, Australia: a prospective cohort study
Authors: Grimley Rohan S , Rosbergen Ingrid CM , Gustafsson Louise , Horton Eleanor , Green Theresa , Cadigan Greg , Kuys Suzanne , Andrew Nadine E , Cadilhac Dominique A 
Published: May 2020

Objective: The aims of this study were to describe patterns and dose of rehabilitation received following stroke and to investigate their relationship with outcomes. Design: This was a prospective observational cohort study. Setting: A total of seven public hospitals and all subsequent rehabilitation services in Queensland, Australia, participated in the study. Subjects: Participants were consecutive patients surviving acute stroke between July 2016 and January 2017. Methods: We tracked rehabilitation for six months following stroke and obtained 90- to 180-day outcomes from the Australian Stroke Clinical Registry. Measures: Dose of rehabilitation – time in therapy by physiotherapy, occupational therapy and speech pathology; modified Rankin Scale (mRS)- premorbid, acute care discharge and 90- to 180-day follow-up. Results: We recruited 504 patients, of whom 337 (median age = 73 years, 41% female) received 643 episodes of rehabilitation in 83 different services. Initial rehabilitation was predominantly inpatient (260/337, 77%) versus community-based (77/337, 21%). Therapy time was greater within inpatient services (median = 29 hours) compared to community-based (6 hours) or transition care (16 hours). Median (Quartile 1, Quartile 3) six-month cumulative therapy time was 73 hours (40, 130) when rehabilitation commenced in stroke units and continued in inpatient rehabilitation units; 43 hours (23, 78) when commenced in inpatient rehabilitation units; and 5 hours (2, 9) with only community rehabilitation. In 317 of 504 (63%) with follow-up data, improvement in mRS was most likely with inpatient rehabilitation (OR = 3.6, 95% CI = 1.7–7.7), lower with community rehabilitation (OR = 1.6, 95% CI = 0.7–3.8) compared to no rehabilitation, after adjustment for baseline factors. Conclusion: Amount of therapy varied widely between rehabilitation pathways. Amount of therapy and chance of improvement in function were highest with inpatient rehabilitation.
The burden of prosthetic hip dislocations in the United States is projected to significantly increase by 2035
Authors: Pirruccio Kevin , Premkumar Ajay , Sheth Neil P 
Published: May 2020

Introduction: Prosthetic hip dislocation is a common, costly complication of total hip arthroplasty (THA). Despite this, the national burden of prosthetic hip dislocations remains uncharacterised in the United States, especially pertaining to injuries occurring years after the index procedure. This study examines historical and projected national estimates of prosthetic hip dislocations presenting to U.S. emergency departments between 2000 and 2035. Methods: We conducted a cross-sectional, retrospective epidemiological study using narratives in the National Electronic Injury Surveillance System (NEISS) database (2000–2017) to identify an estimated 64,671 prosthetic hip implant dislocations presenting to U.S. emergency departments. Estimates for the prevalence of individuals living with a total hip implant were derived from the literature. Results: The national estimate of prosthetic hip dislocations presenting to U.S. emergency departments rose significantly ( p < 0.001) between 2000 ( n = 2395; 95% CI, 1264–3526) and 2017 ( n = 8094; 95% CI, 4276–11,912). These increases are likely driven by increased numbers of people living with THA overall, since between 2000 and 2017, the average incidence of prosthetic hip dislocation (0.14%; CI 0.08–0.21%) in patients living with hip implants has not changed significantly. Linear regression modeling (R2 = 0.7, p < 0.01) projected an increasing number of dislocations through 2035, predicting 10,446 national cases per year by this date. Conclusions: Driven by increases in THA, the annual volume of prosthetic hip dislocations presenting to U.S. emergency departments has increased significantly since 2000 and is projected to continue to rise sharply. Future advances in surgical technique, prosthesis design, and injury prevention policies aimed at decreasing the rate of THA dislocation would help alleviate this mounting national health burden.
Exercise training and cognitive performance in persons with multiple sclerosis: A systematic review and multilevel meta-analysis of clinical trials
Authors: Gharakhanlou Reza , Wesselmann Leonie , Rademacher Annette , Lampit Amit , Negaresh Raoof , Kaviani Mojtaba , Oberste Max , Motl Robert W , Sandroff Brian M , Bansi Jens , Baker Julien S , Heesen Christoph , Zimmer Philipp , Javelle Florian 
Published: May 2020

Background: Cognitive impairment is common, debilitating, and poorly managed in persons with multiple sclerosis (pwMS). Exercise training might have positive effects on cognitive performance in pwMS, yet the overall magnitude, heterogeneity, and potential moderators remain unclear. Objective: This three-level meta-analysis aims to identify the effects of exercise training and those of exercise modalities on global and domain-specific cognitive performance in pwMS. Methods: MEDLINE, PsycInfo, SportDiscus, CENTRAL, and EMBASE were screened for randomized and non-randomized clinical trials from inception to 27 January 2020, yielding 3091 articles. Based on titles and abstracts, 75 articles remained in the selection process. After full-text evaluation, 13 studies were finally selected (PROSPERO pre-registered). Results: The pooled effect of exercise training on the global cognitive performance was null ( g = 0.04, 95% confidence interval (CI): –0.11 to 0.18) and no significant differences were displayed among domains. Heterogeneity within studies was null ([Formula: see text]= 0.0%) and between studies was low ([Formula: see text]= 25.1%). None of the moderators (exercise modalities, age, Expanded Disability Status Scale (EDSS), supervision, cognitive domains) reached significance. However, the exercise volume explained most of the overall heterogeneity (slope = 4.651 × 10−5, [Formula: see text] = 100%, [Formula: see text] = 52.34%). Conclusion: These results do not support the efficacy of exercise training on global or domain-specific cognitive performance in pwMS. Future studies are needed to determine whether higher training dose are beneficial.