bluuebunny/crossref_metadata_2025 huggingface dataset:
Rationalisations for women-only randomised controlled trials in conditions that affect both sexes: a scoping review protocol
Authors: Matthewson Ainsley , Bereznyakova Olena , Dewar Brian , Davis Alexandra , Fedyk Mark , Yogendrakumar Vignan , Fergusson Dean A , Gocan Sophia , Dowlatshahi Dar , Fahed Robert , Shamy Michel
Published: February 2021

Introduction

Women have historically been under-represented in randomised controlled trials (RCTs), including many landmark RCTs that established standards of care. In light of this fact, some modern researchers are calling for replication of earlier landmark trials with women only. This approach is ethically concerning, in that it would require some enrolled women to be deprived of treatments that are currently considered standard of care.

Objective

In an attempt to better understand the justification of a women-only approach to designing clinical trials, this study looks to systematically categorise the number of women-only RCTs for conditions that affect both men and women and the reasons given within the medical and philosophical literatures to perform them.

Methodology

This scoping review of the literature will search, screen and select articles based on predetermined inclusion/exclusion criteria, after which a grounded theory approach will be used to synthesise the data. It is expected that there will be a variety of reasons given for why a women-only trial may be justified. Electronic databases that will be searched include MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Clinical Trials Register, Web of Science Proceedings, ClinicalTrials.gov, Philosopher’s Index, Phil Papers, JSTOR, Periodicals Archive Online, Project MUSE and the National Reference Centre for Bioethics.

Significance

The scope of this study is to determine published rationales used to justify women-only randomised trials, both in the case of new trials and in the repetition of landmark trials.

Ethics and dissemination

Research ethics board approval is not required for this study as there is no participant involvement. Results will be published as a stand-alone manuscript and will inform a larger project related to the ethics of a women-only RCT of carotid intervention for women with symptomatic high-grade carotid stenosis.
Epidemiology of chronic pain in children and adolescents: a protocol for a systematic review update
Authors: Tutelman Perri R , Langley Charlotte L , Chambers Christine T , Parker Jennifer A , Finley G Allen , Chapman Darlene , Jones Gareth T , Macfarlane Gary J , Marianayagam Justina
Published: February 2021

Introduction

Chronic pain, defined as persistent or recurring pain or pain lasting longer than 3 months, is a common childhood problem and can profoundly impact children’s physical, psychological and social functioning. The last comprehensive systematic review estimating the prevalence of chronic pain in children and adolescents was published in 2011. Since then, the literature on paediatric chronic pain has grown substantially. This manuscript outlines a protocol for an updated systematic review to provide updated estimates of the prevalence of various forms of chronic pain in children and adolescence. The review will also examine the relationship between sociodemographic and psychosocial factors related to chronic pain prevalence.

Methods and analysis

This review will follow Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will search EMBASE, PubMed, CINAHL and PsycINFO for observational studies published in English between 2009 and 2020 reporting population-based estimates of chronic non-disease-related pain prevalence in children or adolescents (age ≤19 years). Two independent reviewers will screen the titles and abstracts retrieved from the search based on predefined eligibility criteria. The full texts of relevant studies will then be assessed by two reviewers. Studies meeting inclusion criteria will be categorised according to the type of pain investigated: headache only, abdominal pain only, back pain only, musculoskeletal pain, combined pain, general pain and other pain. Data will be extracted using customised forms and studies will be assessed for risk of bias using a 10-item tool developed by Hoyet al(2012). A narrative synthesis will summarise the prevalence estimates of paediatric chronic pain and associated sociodemographic and psychosocial correlates. Meta-analyses and meta-regressions will be performed if the data permit.

Ethics and dissemination

Ethical approval is not required. Findings will be disseminated through publication in an academic journal, presentations at conferences and in various media.

PROSPERO registration number

CRD42020198690.
Quantification of the peripheral vitreous after vitreous shaving using intraoperative optical coherence tomography
Authors: Nishitsuka Koichi , Nishi Katsuhiro , Namba Hiroyuki , Kaneko Yutaka , Yamashita Hidetoshi
Published: February 2021

Objective

To evaluate the technique of peripheral vitreous shaving during vitrectomy, we measured the residual peripheral vitreous using intraoperative optical coherence tomography (iOCT).

Methods and Analysis

This retrospective study included 44 eyes that underwent 25-gauge pars plana vitrectomy with iOCT by a single surgeon. In all cases, the surgery was performed via ocular indentation. Cases in group A were treated with vitreous shaving under slit lamp microscope illumination, whereas cases in group B were treated with vitreous shaving under a wide-angle viewing system. Residual peripheral posterior vitreous-cortex detachment (PVD) was quantified by iOCT.

Results

iOCT image analysis enabled the visualisation of the angle formed between the retina and peripheral PVD around the vitreous base in all cases. After the completion of vitreous shaving, the mean length of the peripheral PVD was shorter in group A (961.7±214.7 µm) compared with group B (1925.3.7 ± 626.1 µm; p<0.01).

Conclusion

iOCT enabled the quantification of the residual peripheral vitreous after vitreous shaving. The quantification of the residual peripheral vitreous after different shaving procedures will be important for advocating appropriate vitreous shaving in future.
Comparative effectiveness of oral anticoagulants in everyday practice
Authors: Camm A John , Fox Keith A A , Virdone Saverio , Bassand Jean-Pierre , Fitzmaurice David A , Berchuck Samuel I , Gersh Bernard J , Goldhaber Samuel Z , Goto Shinya , Haas Sylvia , Misselwitz Frank , Pieper Karen S , Turpie Alexander G G , Verheugt Freek W A , Cappato Riccardo , Kakkar Ajay K
Published: February 2021

Objectives

This study evaluated the comparative effectiveness of vitamin K antagonists (VKAs), direct thrombin inhibitors (DTIs) and factor Xa inhibitors (FXaI) in patients with atrial fibrillation (AF) at risk of stroke in everyday practice.

Methods

Data from patients with AF and Congestive heart failure, Hypertension, Age 75 years, Diabetes mellitus, prior Stroke, TIA, or thromboembolism, Vascular disease, Age 65-74 years, Sex category (CHA2DS2-VASc) score ≥2 (excluding gender) in the Global Anticoagulant Registry in the FIELD–Atrial Fibrillation registry were analysed using an improved method of propensity weighting, overlap weights and Cox proportional hazards models.

Results

All-cause mortality, non-haemorrhagic stroke/systemic embolism (SE) and major bleeding over 2 years were compared in 25 551 patients, 7162 (28.0%) not treated with oral anticoagulant (OAC) and 18 389 (72.0%) treated with OAC (FXaI (41.8%), DTI (11.4%) and VKA (46.8%)). OAC treatment compared with no OAC treatment was associated with decreased risk of all-cause mortality (HR 0.82 (95% CI 0.74 to 0.91)) and non-haemorrhagic stroke/SE (HR 0.71 (95% CI 0.57 to 0.88)) but increased risk of major bleeding (HR 1.46 (95% CI 1.15 to 1.86)). Non-vitamin K antagonist oral anticoagulant (NOAC) use compared with no OAC treatment was associated with lower risks of all-cause mortality and non-haemorrhagic stroke/SE (HR 0.67 (95% CI 0.59 to 0.77)) and 0.65 (95% CI 0.50 to 0.86)) respectively, with no increase in major bleeding (HR 1.10 (95% CI 0.82 to 1.47)). NOAC use compared with VKA use was associated with lower risk of all-cause mortality and major bleeding (rates/100 patient-years 3.6 (95% CI 3.3 to 3.9) vs 4.8 (95% CI 4.5 to 5.2) and 1.0 (95% CI 0.9 to 1.1) vs 1.4 (95% CI 1.2 to 1.6); HR 0.79 (95% CI 0.70 to 0.89) and 0.77 (95% CI 0.61 to 0.98) respectively), with similar risk of non-haemorrhagic stroke/SE (rates/100 patient-years 0.8 (95% CI 0.7 to 0.9) versus 1.0 (95% CI 0.8 to 1.1); HR 0.96 (95% CI 0.73 to 1.25).

Conclusion

Important benefits in terms of mortality and major bleeding were observed with NOAC versus VKA with no difference among NOAC subtypes.

Trial registration number

NCT01090362.
How individual ethical frameworks shape physician trainees’ experiences providing end-of-life care: a qualitative study
Authors: Rosenwohl-Mack Sarah , Dohan Daniel , Matthews Thea , Batten Jason Neil , Dzeng Elizabeth
Published: February 2021

Objectives

The end of life is an ethically challenging time requiring complex decision-making. This study describes ethical frameworks among physician trainees, explores how these frameworks manifest and relates these frameworks to experiences delivering end-of-life care.

Design

We conducted semistructured in-depth exploratory qualitative interviews with physician trainees about experiences of end-of-life care and moral distress. We analysed the interviews using thematic analysis.

Setting

Academic teaching hospitals in the United States and United Kingdom.

Participants

We interviewed 30 physician trainees. We purposefully sampled across three domains we expected to be associated with individual ethics (stage of training, gender and national healthcare context) in order to elicit a diversity of ethical and experiential perspectives.

Results

Some trainees subscribed to a best interest ethical framework, characterised by offering recommendations consistent with the patient’s goals and values, presenting only medically appropriate choices and supporting shared decision-making between the patient/family and medical team. Others endorsed an autonomy framework, characterised by presenting all technologically feasible choices, refraining from offering recommendations and prioritising the voice of patient/family as the decision-maker.

Conclusions

This study describes how physician trainees conceptualise their roles as being rooted in an autonomy or best interest framework. Physician trainees have limited clinical experience and decision-making autonomy and may have ethical frameworks that are dynamic and potentially highly influenced by experiences providing end-of-life care. A better understanding of how individual physicians’ ethical frameworks influences the care they give provides opportunities to improve patient communication and advance the role of shared decision-making to ensure goal-aligned end-of-life care.
Intrinsic hospital factors: overlooked cause for variations in delay to transfer for endovascular thrombectomy
Authors: Danziger Ron , Tan Christina , Churilov Leonid , Mitchell Peter , Dowling Richard , Bush Steven , Yan Bernard
Published: February 2021

Background

Intrinsic hospital factors leading to time delay to inter-hospital transfer for endovascular thrombectomy (EVT) have not been adequately investigated, leading to uncertainty in generalizability of hub and spoke EVT services. We investigated the contribution of intrinsic hospital factors to variations in time delay in a multicenter, retrospective study.

Methods

The setting was a hub and spoke EVT state-wide system for a population of 6.3 million and 34 spoke hospitals. We collected data on acute large vessel occlusion strokes transferred from spoke to hub for consideration of EVT between January 2016 and December 2018. The primary endpoint was the proportion of variability in delay-time in transfer cases contributed to by intrinsic hospital factors estimated through variance component analysis implemented as a mixed-effect linear regression model with hospitals as random effects.

Results

We included 434 patients. The median age was 72 years (IQR 62–79), 44% were female, and the median baseline National Institutes of Health Stroke Scale (NIHSS) was 16 (IQR 11–20). The median onset to CT time was 100 mins (IQR 69–157) at the spoke hospitals and CT acquisition at the spoke hospital to time of transfer was 93 min (IQR 70–132). 53% of the observed variability in time from CT acquisition at the spoke hospital to transfer to the EVT center was explained by intrinsic hospital factors, as opposed to patient-related factors.

Conclusions

Intrinsic hospital factors explained more than half of the observed variability in time from CT acquisition at the spoke hospital to departure for transfer. We recommend that the design of hub and spoke EVT services should account for intrinsic hospital factors to minimize hospital transfer delay.
Upper extremity transvenous access for neuroendovascular procedures: an international multicenter case series
Authors: Abecassis Isaac Josh , Saini Vasu , Phillips Timothy John , Osbun Joshua W , Martínez-Galdámez Mario , Nada Ahmed , Levitt Michael R , Crowley R Webster , Sattur Mithun G , Spiotta Alejandro M , Luther Evan , Chen Stephanie H , Burks Joshua , Jabbour Pascal , Sweid Ahmad , Psychogios Marios N , Park Min S , Yavagal Dileep R , Peterson Eric C , Waqas Muhammad , Dossani Rimal Hanif , Davies Jason M , Brehm Alex , Selkirk Gregory D , Fox W Christopher , Abud Daniel Giansante , Galvan Fernandez Jorge , Schüller Arteaga Miguel , Starke Robert M
Published: February 2021

Background

Radial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates.

Methods

An international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature.

Results

One hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%).

Conclusions

UETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.
Comparing how Canadian packaged food products align with the 2007 and 2019 versions of Canada’s Food Guide
Authors: Mulligan Christine , Franco-Arellano Beatriz , Ahmed Mavra , Vergeer Laura , Dickinson Kacie , L’Abbé Mary R.
Published: February 2021

In 2019, Canada’s Food Guide (CFG) was updated from the 2007 version. This study developed a food-based nutrient profile model (NPM) to evaluate the alignment of packaged food and beverage products with CFG 2019 and compared it with CFG 2007. Packaged products from the University of Toronto’s Food Label Information Program 2017 database were evaluated in terms of their alignment with CFG 2007 (using the Health Canada Surveillance Tool (HCST)) and CFG 2019 (using our newly developed CFG 2019 NPM). Agreement in alignment (e.g., products “in line” according to CFG 2019 NPM and in Tiers 1 or 2 according to the HCST) was calculated and differences in alignment and reasons for differences were quantified and described. Overall agreement in product alignment between CFG 2007 and 2019 was 81.9%, with fewer products aligned with CFG 2019: 16.4% vs. 31.8%, (χ2 = 189.12, p < 0.001). Differences in alignment varied across food categories (0.0–73.8%), explained by differences in CFG 2019, reflected in the CFG 2019 NPM (e.g., emphasis on avoiding processed foods, encouraging whole grains and low-fat dairy). This study presents a first step in assessing packaged foods’ alignment with CFG 2019; future work is needed to evaluate broader dietary adherence to the updated recommendations.

Novelty: A food-based nutrient profile model was developed based on the 2019 CFG and tested on packaged foods by comparing it with the nutrient-based HCST, based on CFG 2007. Most (82%) packaged products were “not in line” with either CFG version.
The acute and postprandial effects of sugar moiety on vascular and metabolic health outcomes in adolescents
Authors: Koep Jodie L. , Barker Alan R. , Banks Rhys , Banger Rohit R. , Lester Alice , Sansum Kate M. , Weston Max E. , Bond Bert
Published: February 2021

This study explored the cardiometabolic responses to sugar moieties acutely, and following a subsequent mixed meal tolerance test (MMTT). Twenty-one healthy adolescents (N = 10 female, 14.3 ± 0.4 years) completed 3 experimental and 1 control condition, in a counterbalanced order. These consisted of different drinks to compare the effect of 300 mL of water (control), or 300 mL of water mixed with 60 g of glucose, fructose or sucrose, on vascular function (flow-mediated dilation (FMD), microvascular reactivity (total hyperaemic response; TRH), and cerebrovascular reactivity (CVR)), and blood samples for uric acid, glucose, triglycerides and lactate concentrations. FMD increased 1 h after glucose and sucrose (P < 0.001, ES ≥ 0.92) but was unchanged following fructose and water (P ≥ 0.19, ES ≥ 0.09). CVR and TRH were unchanged 1 h following all conditions (P > 0.57, effect size (ES) > 0.02). Following the MMTT, FMD was impaired in all conditions (P < 0.001, ES > 0.40) with no differences between conditions (P > 0.13, ES < 0.39). Microvascular TRH was increased in all conditions (P = 0.001, ES = 0.88), and CVR was preserved in all conditions after MMTT (P = 0.87, ES = 0.02). Blood uric acid concentration was elevated following fructose consumption and the MMTT (P < 0.01, ES > 0.40). Consumption of a sugar sweetened beverage did not result in vascular dysfunction in healthy adolescents; however, the vascular and metabolic responses were dependent on sugar moiety.

Novelty: Glucose consumption acutely increases peripheral vascular function in healthy adolescents. Acute sugar sweetened beverage consumption (sucrose) does not result in adverse vascular outcomes. Elevations in uric acid are observed with fructose consumption, which may have implications over repeated exposure.
Effects of ionized brackish water and polyacrylamide application on infiltration characteristics and improving water retention and reducing soil salinity
Authors: Wei Kai , Zhang Jihong , Wang Quanjiu , Chen Yong , Ding Qian
Published: February 2021

There is an urgent need for brackish groundwater-based irrigation methods to be developed for saline soils that are effective, economically advantageous, and environmentally friendly. The use of both ionized brackish water and polyacrylamide (PAM) might provide such a method. The long-term use of brackish water irrigation can lead to the secondary salinization of soil and, as a consequence, restrict the development of the agricultural economy. Here, we conducted one-dimensional vertical infiltration experiments to examine the effects of ionized brackish water and PAM on soil infiltration characteristics. The result indicated that the water retention of soil first increased and then decreased with the increased in PAM application rates. The maximum water retention of soil was obtained in PAM application of 0.04% for ionized brackish water treatment. Soil water storage for the 0.04% PAM application under ionized brackish water irrigation was the highest and 5.1% higher compared with non-ionized brackish water at a PAM application rate of 0.04%. The ionized brackish water treatment at a PAM application rate of 0.04% improved the desalinization efficiency by 2.3% compared with non-ionized brackish water treatment. Thus, ionized treatment and PAM application are effective for improving the characteristics of soil water and salt transport and permit the safe use of brackish groundwater for irrigation.
Evaluation of a combination of phosphorylated fibers and zeolite as a potential substitute to synthetic wetting agents in peat moss products
Authors: Mouandhoime Zahahe Oulame , Brouillette François
Published: February 2021

Water availability and pH are important factors to consider to determine the suitability of a material for use as a growing medium. Unfortunately, most horticultural substrates are characterized by their water repellency. This is the case with peat moss which is hydrophobic and acidic. Synthetic surfactants are required to improve its wettability. In this study, a combination of phosphorylated wood pulp fibers (FLP) and zeolite is proposed as a substitute to surfactants to increase the wettability of peat moss in the presence of lime, an additive generally used as fertilizer or pH regulator. Results show that lime reduces the water retention capacity of FLP. However, the addition of 15% zeolite to the peat moss/FLP system increases the pH and water retention of the substrate. The negative effect of the presence of 1 wt. % lime on the water retention of the peat moss/FLP mixture was corrected by zeolite addition. Optimal conditions were obtained at 10% zeolite for the two types of lime tested with favorable pH and water retention capacity values. Zeolite was shown to have a higher affinity than FLP for calcium ions preventing the detrimental interaction between FLP and calcium ions.
Adjusting extracellular pH to prevent entry of SARS-CoV-2 into human cells
Authors: Wang Bin
Published: February 2021

The frequent outbreaks of life-threatening RNA viruses, including the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), pose tremendous challenges to humanity. The author proposes that creating a more alkaline extracellular environment that is unsuitable for the fusion between the envelope of SARS-CoV-2 and the host cell membrane is a promising method to prevent the entry of coronaviruses into human cells. The alkaline environment could be achieved by exposing the general public to water-clustered negative air ions (NAIs), both indoors and outdoors, to induce a gradual increase in the pH of the human body. Previous studies have demonstrated that there are no harmful effects of high-concentration NAIs on human health.
Incorporating Uncertainty in Data Labeling into Automatic Detection of Interictal Epileptiform Discharges from Concurrent Scalp-EEG via Multi-way Analysis
Authors: Abdi-Sargezeh Bahman , Valentin Antonio , Alarcon Gonzalo , Sanei Saeid
Published: February 2021

Interictal epileptiform discharges (IEDs) are elicited from an epileptic brain, whereas they can also be due to other neurological abnormalities. The diversity in their morphologies, their strengths, and their sources within the brain cause a great deal of uncertainty in their labeling by clinicians. The aim of this study is therefore to exploit and incorporate this uncertainty (the probability of the waveform being an IED) in the IED detection system which combines spatial component analysis (SCA) with the IED probabilities referred to as SCA-IEDP-based method. For comparison, we also propose and study SCA-based method in which probability of the waveform being an IED is ignored. The proposed models are employed to detect IEDs in two different classification approaches: (1) subject-dependent and (2) subject-independent classification approaches. The proposed methods are compared with two other state-of-the-art methods namely, time–frequency features and tensor factorization methods. The proposed SCA-IEDP model has achieved superior performance in comparison with the traditional SCA and other competing methods. It achieved 79.9% and 63.4% accuracy values in subject-dependent and subject-independent classification approaches, respectively. This shows that considering the IED probabilities in designing an IED detection system can boost its performance.
Production cross-section calculations of 111In via proton and alpha-induced nuclear reactions
Authors: Özdoğan H. , Sarpün İsmail Hakki , Şekerci Mert , Kaplan Abdullah
Published: February 2021

[Formula: see text], a known gamma emitter, is used for many medical purposes such as imaging of myocardial metastases. It can be produced by using different nuclear reactions. In this study, the reactions of [Formula: see text]Ag([Formula: see text]2n)[Formula: see text], [Formula: see text](p,[Formula: see text]n)[Formula: see text], [Formula: see text](p,[Formula: see text]2n)[Formula: see text], [Formula: see text](p,[Formula: see text]3n)[Formula: see text] and [Formula: see text](p,[Formula: see text]4n)[Formula: see text], which are the production routes of [Formula: see text], were investigated. Production cross-section calculations were performed by using equilibrium and pre-equilibrium models of TALYS 1.95 and EMPIRE 3.2 nuclear reaction codes. Hauser–Feshbach Model was appointed in both codes for calculations of equilibrium approximations. Exciton and Hybrid Monte Carlo Simulation (HMS) models were used in the EMPIRE 3.2, whereas Two-Component Exciton and Geometry Dependent Hybrid Model, which is implemented to TALYS code, has been used in the TALYS 1.95 for pre-equilibrium reactions. Also, a weighting matrix of the nuclear models was obtained by using statistical variance analysis. The optimum beam energy to obtain [Formula: see text] has been determined by using the results obtained from this weighting matrix.
Crash behavior modeling and analysis on two interdependent networks
Authors: Zhao Yaning , Xia Chengyi
Published: February 2021

In real-world systems, one random failure or targeted attack may lead to the cascading destruction within a system, and even create the systemic collapse among multiple correlated ones. With the help of network science, modeling the cascade failure on complex networks has become a challenging topic. In this paper, we put forward an improved cascading model on two interdependent networks to further explore the impact of the specific detachment logic on the system collapse, where the distinct condition to leave the system for a pair of nodes exists on the two-layered networks. Meanwhile, once the detachment logic is satisfied, two different criteria are adopted to determine whether this pair of nodes will leave the interdependent networks. Through extensive numerical simulations, we analyze the effects of detachment logic, network topology, departure criteria and nodal coupling relationship between layers in detail. It is found that in our detachment logic, both criteria will render the whole system to exhibit the phenomenon of pseudo-steady state and sudden collapse. In particular, two critical thresholds to characterize the evolution of system crashing emerge, which is different from previous findings under other detachment logic conditions on two-layered networks. Current results are conducive to further understanding the crashing behaviors of interdependent networks and designing the more robust networked systems in practice.
Dynamical analysis, circuit implementation and synchronization of a new memristive hyperchaotic system with coexisting attractors
Authors: Lai Qiang , Wan Zhiqiang , Kamdem Kuate Paul Didier , Fotsin Hilaire
Published: February 2021

This paper constructs a novel memristive hyperchaotic system by introducing the flux-controlled memristor to an extended jerk system. The memristive system has two equilibria and coexists two symmetric hyperchaotic attractors. The dynamic behaviors of the system are studied through bifurcation analysis. The analog circuit design and microcontroller-based experimental implementation of the system are presented. The synchronization of the system is realized by using the adaptive control technique. The sufficient conditions for synchronization are established via theoretical and numerical analysis.
The generalized exponential rational function and Elzaki–Adomian decomposition method for the Heisenberg ferromagnetic spin chain equation
Authors: Sağlam Özkan Yeşim
Published: February 2021

In this paper, the Heisenberg ferromagnetic spin chain equation, which is a model with different magnetic interactions in the classical and semiclassical limits, is investigated using the generalized exponential rational function method. The reduction of the governing equation to a simpler ordinary differential equation by wave transformation is the first step of the procedure. A plurality of the exact solution is obtained by using the relevant method. Physical interpretations of some obtained solutions are also included. Particularly, upon choosing appropriate parameters, various plots are depicted. We achieve also a numerical solution corresponding to the initial value problem by the Elzaki–Adomian decomposition method and give comparative results in a table. Moreover, by using Maple, some graphical simulations are done to see the behavior of these solutions with choosing the suitable parameters.
On Edge-Fault Tolerance in Augmented Cubes
Authors: SHINDE AMRUTA , BORSE Y. M.
Published: February 2021

The augmented cube AQn is one of the important variations of the hypercube Qn. In this paper, we prove that the conditional h-edge connectivity of AQn with n ≥ 3 is 8n − 16 for h = 3 and 2n for h = 2n − 3. We also obtain an upper bound on the conditional h-edge connectivity for odd integer h satisfying [Formula: see text].
The Mechanical Properties of Origami Structure Determined by the Improved Virtual Crease Method
Authors: Wang Wei , Qiu Xinming
Published: February 2021

The mechanical properties and deformation of Origami structures are studied in this paper. Usually, it is a coupling problem of crease rotation and shell deformation. Here, the creases are simplified as torsional springs, whose rotational stiffness [Formula: see text] is obtained by the experiment of compressing a creased shell. While the shells that may have large deformation are simplified as rigid plates connected by virtual creases, whose rotational stiffness is roughly expressed as bending stiffness divides width of the shell. Hence, a coupling factor [Formula: see text] is defined to evaluate the coupling effect of creases and shells. Implementing the obtained rotational stiffnesses of real and virtual creases into the expression of strain energy, an improved Virtual Crease Method (VCM) is proposed. By analyzing the bi-stability of creased shell and Miura-Ori structure, the accuracy and convergence of this improved VCM is proved.
Static Response Analysis of Uncertain Structures With Large-Scale Unknown-But-Bounded Parameters
Authors: Wei Tonghui , Li Feng , Meng Guangwei , Zuo Wenjie
Published: February 2021

This paper proposes an interval finite element method based on function decomposition for structural static response problems with large-scale unknown-but-bounded parameters. When there is a large number of uncertain parameters, it will lead to the curse of dimensionality. The existing Taylor expansion-based methods, which is often employed to deal with large-scale uncertainty problems, need the sensitivity information of response function to uncertain parameters. However, the gradient information may be difficult to obtain for some complicated structural problems. To overcome this drawback, univariate decomposition expression (UDE) and bivariate decomposition expression (BDE) are deduced by the higher-order Taylor series expansion. The original structure function with [Formula: see text]-dimensional interval parameters is decomposed into the sum of several low-dimensional response functions by UDE or BDE, each of which has only one or two interval parameters while the other interval parameters are replaced by their midpoint values. Therefore, solving the upper and lower bounds of the [Formula: see text]-dimensional function can be converted into solving those of the one- or two-dimensional functions, which savethe calculation costs and can be easily implemented. The accuracy and efficiency of the new method are verified by three numerical examples.
Parametric Study on Mechanical, Thermal and Electrical Properties of Graphene Reinforced Composites by Effective Medium Theory
Authors: Tong Zhilin , Wang Yu , Feng Chuang , Zhu Dong , Jin Sujing
Published: February 2021

This paper conducts theoretical study on the mechanical, thermal and electrical properties of graphene reinforced composites by effective medium theory (EMT). Considering the imperfect bonding between the reinforcing fillers and the matrix, an interphase surrounding the graphene fillers is introduced during the EMT modeling. The coated graphene fillers are homogenized as effective reinforcements dispersed in a matrix. The EMT model is validated by comparing the predicted material properties with previously reported results. Parametric study is carried out to investigate the influences of several parameters, including concentration and geometry of graphene fillers, the attributes of the introduced an interphase and the alternating current (AC) frequency, upon the effective material properties of the reinforced composites. The results demonstrate that the increase of the thickness of the interphase results in the decrease of Young’s modulus, thermal conductivity and electrical conductivity of the composites while it is favorable to enhance the dielectric properties of the composites. The increase in the aspect ratio of the graphene filler enhances all material properties involved. Percolation behaviors are observed for the dielectric properties of the composites. Moreover, the dielectric properties of the composites are very sensitive to the change of the AC frequency within a certain range, which suggests the achievement of active tuning of material properties.
Numerical Model for Formation and Evolution of the Bleb
Authors: Feng Jiju , Tang Liqun , Liu Zejia , Dong Shoubin , Zhou Licheng , Liu Yiping , Jiang Zhenyu
Published: February 2021

The morphology of a bleb and its changes are critical to the amoeboid migration of a cell. By releasing bonds between the membrane and the cortex of a cell, the formation of a bleb can be observed experimentally, but the mechanism that affects the size and shape of a bleb during amoeboid migration requires further study. In this study, by adapting the governing equations and discrete equations of the two-dimensional fluid–solid coupling model recommended by Strychalski and Guy [2013 “A computational model of bleb formation,” Mathematical Medicine and Biology 30(2), 115–130], we overcome the defect that the bleb by traditional means is always too small compared with experimental results, and simulate the behaviors of cell blebs successfully. The effects of various parameters such as the number of broken bonds, the viscosity coefficient of the cortex, and the cell’s membrane modulus on the size and the shape of the bleb are investigated. Numerical results show that the model effectively simulates the formation and evolution of a bleb, thus, the contributions of several factors to bleb shape and size are successfully derived.
A Finite Strain Analytical Solution for Stress-Softening of Hyperelastic Materials Under Cyclic Bending
Authors: Pashazadeh Jafar , Amiri Arya , Taheri Ali , Baghani Mostafa
Published: February 2021

In this paper, a new approach for stress-softening of an isotropic, incompressible, hyperelastic and rectangular beam that undergoes cyclic bending-unbending deformation, is presented. Employing an exponential softening function, damage response of the hyperelastic beam due to cyclic finite bending is investigated. The stress-softening phenomenon occurs in elastomeric materials when they deform for the first time. Under the same deformation, the stress required in reloading is smaller than the initial loading stage. This is known as the Mullins effect. To verify the accuracy of the proposed solution, finite element analysis of the same problem is carried out. In this study, a principal stretch-based strain energy function i.e., Ogden model and an invariant-based function such as a newly introduced Exp–Exp model are used for all bending, unbending and re-bending procedures. The proposed method needs a much shorter time compared to FEM simulations. Thus, in design and optimization of the structures under bending that requires a large number of analyses, the proposed semi-analytical solution can be considered as an efficient tool for studying the effects of different material and geometrical parameters.
Force Steadiness: From Motor Units to Voluntary Actions
Authors: Enoka Roger M. , Farina Dario
Published: February 2021

Voluntary actions are controlled by the synaptic inputs that are shared by pools of spinal motor neurons. The slow common oscillations in the discharge times of motor units due to these synaptic inputs are strongly correlated with the fluctuations in force during submaximal isometric contractions (force steadiness) and moderately associated with performance scores on some tests of motor function. However, there are key gaps in knowledge that limit the interpretation of differences in force steadiness.
Associations among Cognitive Functions, Plasma DNA, and Diffusion Tensor Image along the Perivascular Space (DTI‐ALPS) in Patients with Parkinson’s Disease
Authors: Chen Hsiu-Ling , Chen Pei-Chin , Lu Cheng-Hsien , Tsai Nai-Wen , Yu Chiun-Chieh , Chou Kun-Hsien , Lai Yun-Ru , Taoka Toshiaki , Lin Wei-Che
Published: February 2021

Background. Parkinson’s disease (PD) is a common neurodegenerative disease associated with accumulation of misfolding proteins and increased neuroinflammation, which may further impair the glymphatic system. The purpose of this study was to utilize diffusion tensor image analysis along the perivascular space (DTI‐ALPS) to evaluate glymphatic system activity and its relationship with systemic oxidative stress status in PD patients. Methods. Magnetic resonance imaging and neuropsychological tests were conducted on 25 PD patients with normal cognition (PDN), 25 PD patients with mild cognitive impairment (PD‐MCI), 38 PD patients with dementia (PDD), and 47 normal controls (NC). Oxidative stress status was assessed by plasma DNA level. Differences in ALPS‐index among the subgroups were assessed and further correlated with cognitive functions and plasma DNA levels. Results. The PD‐MCI and PDD groups showed significantly lower ALPS‐index compared to normal controls. The ALPS‐index was inversely correlated with plasma nuclear DNA, mitochondrial DNA levels, and cognitive scores. Conclusions. Lower diffusivity along the perivascular space, represented by lower ALPS‐index, indicates impairment of the glymphatic system in PD patients. The correlation between elevated plasma nuclear DNA levels and lower ALPS‐index supports the notion that PD patients may exhibit increased oxidative stress associated with glymphatic system microstructural alterations.
Self-Sustained Oscillation of a Photothermal-Responsive Pendulum under Steady Illumination
Authors: Ge Dali , Xu Peibao , Li Kai
Published: February 2021

Self-sustained oscillation has the advantages of harvesting energy from the environment and self-control, and thus, the development of new self-oscillating systems can greatly expand its applications in active machines. In this paper, based on conventional photothermal shrinkable material or photothermal expansive material, a simple pendulum is proposed. The light-powered self-sustained oscillation of the simple pendulum is theoretically studied by establishing a dynamic model of the photothermal-responsive pendulum. The results show that there are two motion modes of the simple pendulum, which are the static mode and the oscillation mode. Based on the photothermal-responsive model, this paper elucidates the mechanism of the self-excited oscillation. The condition for triggering self-excited oscillation is further studied. In addition, the influence of the system parameters on the amplitude and frequency is also obtained. This study may have potential applications in energy harvesting, signal monitoring, and soft machines.
A Study of the Anchorage Body Fracture Evolution and the Energy Dissipation Rule: Comparison between Tensioned Rock Bolts and Torqued Rock Bolts
Authors: Wu Bowen , Wang Xiangyu , Bai Jianbiao , Liu Shuaigang , Wang Guanghui , Li Guanjun
Published: February 2021

Rock bolt support is an effective technique for controlling surrounding rock of deep roadway. The stability of the anchorage body composed of rock bolts and surrounding rock mass is the core in keeping the stability of roadways. In this paper, the UDEC Trigon model was used in simulating uniaxial compressive test on the anchorage body under different pretension loads. The energy equilibrium criterion of the anchorage body under the uniaxial compressive state was proposed. Furthermore, the fracture evolution and the energy dissipation during the failure process of the anchorage body were analyzed. Results showed that before the peak strength, the external work was stored in the anchorage body in the form of the elastic strain energy (Ue). After the peak, energy dissipated through three ways, including the fracture developing friction (Wf), plastic deformation (Wp), and acoustic emission (Ur). Based on the simulation results, the high pretensioned rock bolts can eliminate the continuous tensile fractures in the anchorage body, decreasing the damaging extent of the anchorage body and the energy that was consumed by the following two main approaches: fracture developing friction (Wf) and plastic deformation (Wp). Moreover, the surplus of the elastic strain energy (Ue) and the strength of the anchorage body can be improved. The pretension load had a positive relationship with elastic strain energy and a negative relationship with the anchorage body damage degree. Based on the above research, the transport roadway of the working face 6208 in the Wangzhuang Coal Mine selected tensile rock bolts to establish the high‐performance anchorage body. The monitoring data showed that this reinforcement method effectively managed the serious deformation issue of the roadway surrounding the rock masses.
Experimental Evaluation of Multiple Frost Heaving Parameters for Preflawed Granite in Beizhan Iron Mining, Xinjiang, China
Authors: Wang Yu , Long Dayu , Rejuti Zulifeiya , Wang Huajian
Published: February 2021

Ice-driven mechanical weathering in cold regions is considered a main factor impacting the stability of rock mass. In this work, the response surface method (RSM) was employed to evaluate and optimize the multiple frost heaving parameters to seek the maximum frost heaving force (FHF), in combination with experimental modeling based on a specially designed frost heaving force measurement system. Three kinds of rocks were prepared with parallel flaws in it having different flaw width, length, and cementation type, and these factors were used to fit an optimal response of the maximum FHF. The experimental results reveal five distinguished stages from the frost heaving force curve, and they are inoculation stage, explosive stage, decline to steady stage, recovery stage, and sudden drop stage. The sensitivity analysis reveals the influential order of the considered factors to peak FHF, which is the rock lithology, flaw width, flaw cement type, and flaw length. For low-porosity hard rock, increasing flaw width, flaw length, and flaw cement strength can improve the probability of frost heaving failure. It is suggested that rock lithology determines the water migration ability and influences the water-ice phase transformation a lot.
An Experimental Study on [125I]I-pHLIP (Var7) for SPECT/CT Imaging of an MDA-MB-231 Triple-Negative Breast Cancer Mouse Model by Targeting the Tumor Microenvironment
Authors: Yu Mingming , Sun Yanqin , Yang Guangjie , Wang Zhenguang
Published: February 2021

Objective. To evaluate the diagnostic efficacy of MDA-MB-231 triple-negative breast cancer with 125I-labeled pHLIP (Var7) by single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. Methods. The binding fraction of [125I]I-pHLIP (Var7) and MDA-MB-231 cells was measured at pH 7.4 and pH 6.0, and tumor-bearing mice were subjected to small-animal SPECT/CT imaging studies. Results. At [Formula: see text], the binding fractions of [125I]I-pHLIP (Var7) and MDA-MB-231 cells at 10 min, 40 min, 1 h, and 2 h were 1[Formula: see text]%, [Formula: see text]%, [Formula: see text]%, and [Formula: see text]%, respectively. At [Formula: see text], there was no measured binding between [125I]I-pHLIP (Var7) and MDA-MB-231 cells. Small-animal SPECT/CT imaging showed clearly visible tumors at 1 and 2 h after injection. Conclusions. [125I]I-pHLIP (Var7) could bind to MDA-MB-231 cells in an acidic environment, and small-animal SPECT/CT imaging showed clear tumors at 1 and 2 h after probe injection.
Orthogonal Stability and Nonstability of a Generalized Quartic Functional Equation in Quasi-β-Normed Spaces
Authors: Alessa Nazek , Tamilvanan K. , Loganathan K. , Karthik T. S. , Rassias John Michael
Published: February 2021

In this work, we examine the generalized Hyers-Ulam orthogonal stability of the quartic functional equation in quasi-β-normed spaces. Moreover, we prove that this functional equation is not stable in a special condition by a counterexample.
A Dual-Mode Medium Access Control Mechanism for UAV-Enabled Intelligent Transportation System
Authors: Khan Muhammad Asghar , Cheema Tanweer Ahmad , Ullah Insaf , Noor Fazal , Rehman Sajjad Ur , Rehman Ateeq Ur , Aziz Muhammad Adnan
Published: February 2021

With the exponential growth in technologies for the vehicular Internet of things applications and high demands for autonomous road vehicles, future transportation systems are projected to be revolutionized on a global scale. This new landscape requires a stable, flexible, and business-friendly base of connectivity, networking, and computing technology, in which Unmanned Aerial Vehicles (UAVs) can play an important role. A UAV-enabled Intelligent Transportation System (ITS) can provide a cost-effective communication solution to improve the safety and efficiency of the transportation system, particularly if the data traffic is nonhomogeneous and nonstationary. Typically, wireless is the communication medium between vehicles and UAVs in an ITS setting, which is based on the IEEE802.11p MAC protocol adopted by car manufactures. However, the IEEE 802.11p MAC protocol is modified solely for omnidirectional antennas, which restricts network coverage, delay, and throughput. In comparison, the directional antenna has greater network coverage, spatial reuse, and bandwidth. In addition, a multiaccess edge computing (MEC) facility at the backhaul link will provide ultralow latency and high bandwidth services to meet the increasingly growing demand for latency-sensitive vehicle applications such as vehicular video data analytics, autonomous driving, and intelligent navigation. Therefore, this article aims to propose a novel dual-mode MAC protocol that can work in two antenna modes, i.e., directional and omnidirectional. For modeling and simulation purposes, we use the Optimized Network Engineering Tool (OPNET) and aim to seek an evaluation with respect to throughput, media access delay, and retransmission attempts. The results obtained demonstrate the effectiveness of the proposed scheme.