bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuroendovascular clinical trials disruptions due to COVID-19. Potential future challenges and opportunities
Authors: Rai Ansaar T , Leslie-Mazwi Thabele M , Fargen Kyle M , Pandey Aditya S , Dabus Guilherme , Hassan Ameer E , Fraser Justin F , Hirsch Joshua A , Gupta Rishi , Hanel Ricardo , Yoo Albert J , Bozorgchami Hormozd , Fiorella David , Mocco J , Arthur Adam S , Zaidat Osama , Siddiqui Adnan H
Published: June 2020

To assess the impact of COVID-19 on neurovascular research and deal with the challenges imposed by the pandemic.

Methods

A survey-based study focused on randomized controlled trials (RCTs) and single-arm studies for acute ischemic stroke and cerebral aneurysms was developed by a group of senior neurointerventionalists and sent to sites identified through the clinical trials website (https://clinicaltrials.gov/), study sponsors, and physician investigators.

Results

The survey was sent to 101 institutions, with 65 responding (64%). Stroke RCTs were being conducted at 40 (62%) sites, aneurysm RCTs at 22 (34%) sites, stroke single-arm studies at 37 (57%) sites, and aneurysm single-arm studies at 43 (66%) sites. Following COVID-19, enrollment was suspended at 51 (78%) sites—completely at 21 (32%) and partially at 30 (46%) sites. Missed trial-related clinics and imaging follow-ups and protocol deviations were reported by 27 (42%), 24 (37%), and 27 (42%) sites, respectively. Negative reimbursements were reported at 17 (26%) sites. The majority of sites, 49 (75%), had put new trials on hold. Of the coordinators, 41 (63%) worked from home and 20 (31%) reported a personal financial impact. Remote consent was possible for some studies at 34 (52%) sites and for all studies at 5 (8%) sites. At sites with suspended trials (n=51), endovascular treatment without enrollment occurred at 31 (61%) sites for stroke and 23 (45%) sites for aneurysms. A total of 277 patients with acute ischemic stroke and 184 with cerebral aneurysms were treated without consideration for trial enrollment.

Conclusion

Widespread disruption of neuroendovascular trials occurred because of COVID-19. As sites resume clinical research, steps to mitigate similar challenges in the future should be considered.
THE IMPACT OF ICT ON SERVICE TRADE
Authors: LUONG TUAN ANH , NGUYEN THU HANG
Published: June 2020

While trade in goods has been investigated extensively over decades, studies on trade in services are relatively new. In this paper, we investigate the impacts of information and communication technology (ICT) on trade in services. We measured ICT by four dimensions, including the subscriptions to broadband, fixed telephones, mobile phones and Internet. Our sample covered more than 200 countries from 2005 to 2015. We employed the modified gravity model and found that all four dimensions had significant impacts on the expansion trade in services, but mobile subscriptions are the most consistent dimensions. Finally, the effects of ICT in exporting and importing countries are similar.
Optimal Design of Ultra-Low-Power 2.4 GHz LNA for IEEE 802.15.4/Bluetooth Applications
Authors: Ghosh Sumalya , De Bishnu Prasad , Maji K. B. , Kar R. , Mandal D. , Mal A. K.
Published: June 2020

In this paper, an evolutionary computation-based optimal design of low power, high gain inductive source degenerated CMOS cascode low noise amplifier (LNA) circuit is presented for 2.4[Formula: see text]GHz frequency. The main challenge for the design of radio frequency (RF) LNAs at nanometer range is the thermal noise generated in the short-channel MOSFETs. The short-channel effects (SCEs), such as velocity saturation and channel-length modulation, are considered for the design of CMOS LNA. The evolutionary algorithm taken for this work is Moth-Flame Optimization (MFO) algorithm. MFO is utilized for the optimization of noise figure (NF) while satisfying all the other design performance parameters like gain, matching parameters at input/output, power dissipation, linearity, stability. Optimal values of the sizes of the transistors and other design parameters in designing the LNA circuit are also obtained from the MFO algorithm. The CMOS LNA circuit is designed by using MFO-based optimal design parameters in CADENCE software with a standard 0.18[Formula: see text][Formula: see text]m CMOS process. The designed LNA shows a gain of 15.28[Formula: see text]dB, NF of 0.376[Formula: see text]dB, the power dissipation of 936[Formula: see text][Formula: see text]W and IIP3 of [Formula: see text][Formula: see text]dBm at 2.4[Formula: see text]GHz. The designed LNA achieves better trade-off which results in an FOM of 42.3[Formula: see text]mW[Formula: see text] and may be useful in the receiver module of IEEE 802.15.4 for WLAN applications.
Evolution of cosmological horizons of wormhole cosmology
Authors: Kim Sung-Won
Published: June 2020

Recently, we solved Einstein’s field equations to obtain the exact solution of the cosmological model with the Morris–Thorne-type wormhole. We found the apparent horizons and analyzed their geometric natures, including the causal structures. We also derived the Hawking temperature near the apparent cosmological horizon. In this paper, we investigate the dynamic properties of the apparent horizons under the matter-dominated universe and lambda-dominated universe. As a more realistic universe, we also adopt the [Formula: see text]CDM universe which contains both the matter and lambda. The past light cone and the particle horizon are examined for what happens in the case of the model with wormhole. Since the spatial coordinates of the spacetime with the wormhole are limited outside the throat, the past light cone can be operated by removing the smaller-than-wormhole region. The past light cones without wormhole begin to start earlier than the past light cones with wormhole in conformal time-proper distance coordinates. The light cone consists of two parts: the information from our universe and the information from other universe or far distant region through the wormhole. Therefore, the particle horizon distance determined from the observer’s past light cone cannot be defined in a unique way.
Thermodynamics and reentrant phase transition for logarithmic nonlinear charged black holes in massive gravity
Authors: Chaloshtary S. Rajaee , Zangeneh M. Kord , Hajkhalili S. , Sheykhi A. , Zebarjad S. M.
Published: June 2020

We investigate a new class of [Formula: see text]-dimensional topological black hole solutions in the context of massive gravity and in the presence of logarithmic nonlinear electrodynamics. Exploring higher-dimensional solutions in massive gravity coupled to nonlinear electrodynamics is motivated by holographic hypothesis as well as string theory. We first construct exact solutions of the field equations and then explore the behavior of the metric functions for different values of the model parameters. We observe that our black holes admit the multi-horizons caused by a quantum effect called anti-evaporation. Next, by calculating the conserved and thermodynamic quantities, we obtain a generalized Smarr formula. We find that the first law of black holes thermodynamics is satisfied on the black hole horizon. We study thermal stability of the obtained solutions in both canonical and grand canonical ensembles. We reveal that depending on the model parameters, our solutions exhibit a rich variety of phase structures. Finally, we explore, for the first time without extending thermodynamics phase space, the critical behavior and reentrant phase transition for black hole solutions in massive gravity theory. We realize that there is a zeroth-order phase transition for a specified range of charge value and the system experiences a large/small/large reentrant phase transition due to the presence of nonlinear electrodynamics.
Universality of short distance corrections to quantum optics
Authors: Faizal Mir , Momeni Davood
Published: June 2020

As quantum optical phenomena are based on Maxwell’s equations, and it is becoming important to understand quantum optical phenomena at short distances, so it is important to analyze quantum optics using short distance corrected Maxwell’s equation. Maxwell’s action can be obtained from quantum electrodynamics using the framework of effective field theory, and so the leading order short distance corrections to Maxwell’s action can also be obtained from the derivative expansion of the same effective field theory. Such short distance corrections will be universal for all quantum optical systems, and they will affect all short distance quantum optical phenomena. In this paper, we will analyze the form of such corrections, and demonstrate the standard formalism of quantum optics can still be used (with suitable modifications) to analyze quantum optical phenomena from this short distance corrected Maxwell’s actions.
Implications of Changes in GAAP for Business Combinations (and Goodwill) on Accounting and Finance Research
Authors: Chaney Paul K. , Gunn Rita Nevada , Coleman Jeter Debra
Published: June 2020

The accounting standards related to mergers and acquisitions (M&A) have changed drastically in the past twenty years. In spite of significant debate and arguments that the proposed accounting changes might hinder optimal decision-making, the use of business combinations as a means of growth by international companies has escalated. In this paper, we review the extant academic literature on the subject, as well as the changes in the standards on accounting for M&A. We also express some concerns about the ways the standard changes impact accounting data, and the need for extra care in addressing these changes in academic research. The changes addressed include the accounting for goodwill and bargain purchases, contingent consideration (such as earnouts), step acquisitions, and in-process R&D. We present pros and cons for many of these changes, and offer some alternatives and recommendations for improvement as we move forward. In addition, we provide an analysis of the number of M&A transactions relevant in various accounting standard-setting periods and by M&A topic (consideration used, earnouts, step acquisitions, and non-controlling interests).
An analytical solution with existence and uniqueness conditions for fractional integro-differential equations
Authors: Verma Pratibha , Kumar Manoj
Published: June 2020

This study aims to apply the two-step Adomian decomposition method (TSADM) to find an analytical solution of integro-differential equations for fractional order without discretization/approximation with less number of iterations and reduce the computational efforts. Moreover, we have established the results for the existence and uniqueness of a solution with the help of some fixed point theorems and the Banach contraction principle. Furthermore, the method is demonstrated on different test examples arising in real life situations. It is concluded that the TSADM provides exact solution of the fractional integro-differential equations in one iteration. At the same time, the other existing methods furnish an approximate solution and require lots of computation to solve the problem applying discretization/approximation on fractional operators.
Regional geological analysis of the southern deep Gulf of Mexico and northern Yucatán Shelf
Authors: Miranda-Madrigal Ernesto , Chávez-Cabello Gabriel
Published: June 2020

We discuss the sedimentary and structural evolution, and oil possibilities, of a Late Jurassic-Early Cretaceous major salt detached extensional–contractional province in the Yucatán sub-basin at the southern Gulf of Mexico using 2D seismic reflection profiles and well data from the Deep Sea Drilling Project (DSDP). The main basement trends are a central depression that accommodates the pre-salt sequences, and a long ridge where the continental–oceanic crust transition is found. Along this ridge, the geometry of the outer trough was defined by mapping the base salt. The base salt changes from steeply dipping on the Campeche Escarpment to irregular-horizontal on the limit with the recognized outer trough. The extensional–contractional system was divided into three subdomains with: (1) tilted blocks; (2) growth faults and rollover anticlines; and (3) diapirs and fold and thrust. We regionally identify the highest sedimentation stages through the Tertiary, the possible main directions of sediment supply to the basin and their relationship to Neogene diapirism. The two structural traps formation times interpreted in the area are: (a) Late Jurassic-Early Cretaceous traps associated with seaward salt translation; and (b) middle Miocene–early Pliocene traps related to diapiric growth in the outer trough, triggered by sediment load derived from the north of the Gulf of Mexico and from SE Mexico, where the Chiapanecan Orogeny was developed. The integration of the results of this study with the evidence of some elements and processes of the petroleum system allow us to propose that the area may represent an important oil province.
Assembly and Dynamics of the Bacterial Flagellum
Authors: Armitage Judith P. , Berry Richard M.
Published: June 2020

The bacterial flagellar motor is the most complex structure in the bacterial cell, driving the ion-driven rotation of the helical flagellum. The ordered expression of the regulon and the assembly of the series of interacting protein rings, spanning the inner and outer membranes to form the ∼45–50-nm protein complex, have made investigation of the structure and mechanism a major challenge since its recognition as a rotating nanomachine about 40 years ago. Painstaking molecular genetics, biochemistry, and electron microscopy revealed a tiny electric motor spinning in the bacterial membrane. Over the last decade, new single-molecule and in vivo biophysical methods have allowed investigation of the stability of this and other large protein complexes, working in their natural environment inside live cells. This has revealed that in the bacterial flagellar motor, protein molecules in both the rotor and stator exchange with freely circulating pools of spares on a timescale of minutes, even while motors are continuously rotating. This constant exchange has allowed the evolution of modified components allowing bacteria to keep swimming as the viscosity or the ion composition of the outside environment changes.
Harnessing Advances in Agricultural Technologies to Optimize Resource Utilization in the Food-Energy-Water Nexus
Authors: Miao Ruiqing , Khanna Madhu
Published: June 2020

The food-energy-water (FEW) nexus is facing grand challenges in meeting increasing demand resulting from global changes in climate, economy, and population. Emerging technologies are expected to play a critical role in responding to these challenges. Focusing on four types of prominent emerging technologies (namely precision agriculture coupled with big data and machine learning, gene editing, second-generation biofuels, and agrivoltaics), this article reviews existing studies regarding opportunities and challenges of these emerging technologies to address issues of the FEW nexus. Drivers of innovation and adoption of these emerging technologies as well as the role of public policies that interact with these drivers are reviewed. Finally, this review also discusses research gaps that need to be filled to harness the potential benefits of these emerging technologies.
Climate Change and Forests
Authors: Sohngen Brent
Published: June 2020

Forests have become an important carbon sink in the last century, with management and carbon fertilization offsetting nearly all of the carbon emitted due to deforestation and conversion of land into agricultural uses. Society appears already to have decided that forests will play an equally ambitious role in the future. Given this, economists are needed to help better understand the efficiency of efforts society may undertake to expand forests, protect them from losses, manage them more intensively, or convert them into wood products, including biomass energy. A rich literature exists on this topic, but a number of critical information gaps persist, representing important opportunities for economists to advance knowledge in the future. This article reviews the literature on forests and climate change and provides some thoughts on potential future research directions.
Viperin Reveals Its True Function
Authors: Rivera-Serrano Efraín E. , Gizzi Anthony S. , Arnold Jamie J. , Grove Tyler L. , Almo Steven C. , Cameron Craig E.
Published: June 2020

Most cells respond to viral infections by activating innate immune pathways that lead to the induction of antiviral restriction factors. One such factor, viperin, was discovered almost two decades ago based on its induction during viral infection. Since then, viperin has been shown to possess activity against numerous viruses via multiple proposed mechanisms. Most recently, however, viperin was demonstrated to catalyze the conversion of cytidine triphosphate (CTP) to 3′-deoxy-3′,4′-didehydro-CTP (ddhCTP), a previously unknown ribonucleotide. Incorporation of ddhCTP causes premature termination of RNA synthesis by the RNA-dependent RNA polymerase of some viruses. To date, production of ddhCTP by viperin represents the only activity of viperin that links its enzymatic activity directly to an antiviral mechanism in human cells. This review examines the multiple antiviral mechanisms and biological functions attributed to viperin.
Molecular Mechanisms of Merkel Cell Polyomavirus Transformation and Replication
Authors: Liu Wei , You Jianxin
Published: June 2020

Viral infection underlies a significant share of the global cancer burden. Merkel cell polyomavirus (MCPyV) is the newest member of the human oncogenic virus family. Its discovery over a decade ago marked the beginning of an exciting era in human tumor virology. Since then, significant evidence has emerged to support the etiologic role of MCPyV in Merkel cell carcinoma (MCC), an extremely lethal form of skin cancer. MCPyV infection is widespread in the general population. MCC diagnoses have tripled over the past 20 years, but effective treatments are currently lacking. In this review, we highlight recent discoveries that have shaped our understanding of MCPyV oncogenic mechanism and host cellular tropism, as well as the molecular events occurring in the viral infectious life cycle. These insights will guide future efforts in developing novel virus-targeted therapeutic strategies for treating the devastating human cancers associated with this new tumorigenic virus.
The Hepatitis B Virus Envelope Proteins: Molecular Gymnastics Throughout the Viral Life Cycle
Authors: Seitz Stefan , Habjanič Jelena , Schütz Anne K. , Bartenschlager Ralf
Published: June 2020

New hepatitis B virions released from infected hepatocytes are the result of an intricate maturation process that starts with the formation of the nucleocapsid providing a confined space where the viral DNA genome is synthesized via reverse transcription. Virion assembly is finalized by the enclosure of the icosahedral nucleocapsid within a heterogeneous envelope. The latter contains integral membrane proteins of three sizes, collectively known as hepatitis B surface antigen, and adopts multiple conformations in the course of the viral life cycle. The nucleocapsid conformation depends on the reverse transcription status of the genome, which in turn controls nucleocapsid interaction with the envelope proteins for virus exit. In addition, after secretion the virions undergo a distinct maturation step during which a topological switch of the large envelope protein confers infectivity. Here we review molecular determinants for envelopment and models that postulate molecular signals encoded in the capsid scaffold conducive or adverse to the recruitment of envelope proteins.
Deficiency of bone morphogenetic protein-3b induces metabolic syndrome and increases adipogenesis
Authors: Martí-Pàmies Íngrid , Thoonen Robrecht , Seale Patrick , Vite Alexia , Caplan Alex , Tamez Jesus , Graves Lauren , Han Wei , Buys Emmanuel S. , Bloch Donald B. , Scherrer-Crosbie Marielle
Published: June 2020

Bone morphogenetic protein (BMP) receptor signaling is critical for the regulation of the endocrine system and cardiovascular structure and function. The objective of this study was to investigate whether Bmp3b, a glycoprotein synthetized and secreted by adipose tissue, is necessary to regulate glucose and lipid metabolism, adipogenesis, and cardiovascular remodeling. Over the course of 4 mo, Bmp3b-knockout ( Bmp3b−/−) mice gained more weight than wild-type (WT) mice. The plasma levels of cholesterol and triglycerides were higher in Bmp3b−/− mice than in WT mice. Bmp3b−/− mice developed insulin resistance and glucose intolerance. The basal heart rate was higher in Bmp3b−/− mice than in WT mice, and echocardiography revealed eccentric remodeling in Bmp3b−/− mice. The expression of adipogenesis-related genes in white adipose tissue was higher in Bmp3b−/− mice than in WT control mice. In vitro studies showed that Bmp3b modulates the activity of the C/ebpα promoter, an effect mediated by Smad2/3. The results of this study suggest that Bmp3b is necessary for the maintenance of homeostasis in terms of age-related weight gain, glucose metabolism, and left ventricular (LV) remodeling and function. Interventions that increase the level or function of BMP3b may decrease cardiovascular risk and pathological cardiac remodeling.
Application of FBG Sensing Technology to Internal Deformation Monitoring of Landslide
Authors: Peng Haiyou , Chen Bolin , Dong Ping , chen Si , Liao Yunping , Guo Qi
Published: June 2020

Limited by geological survey methods, processes, and cost, it has long been a difficult thing to accurately detect the position of landslide slip surface and monitor the landslide internal deformation. Fiber Bragg grating (FBG) sensing technology has been widely used in geological engineering and geotechnical engineering due to its high‐precision property. In this research, FBG sensing technology was applied to the monitoring of landslide internal deformation in Toudu, Chongqing, China. The in situ monitoring by FBG accurately determined the position of the landslide slip surface. Based on the relationship between fiber grating strain and deflection, the formula between landslide internal deformation and fiber grating strain was obtained, and the rationality of the formula was verified by the monitoring data of surface displacement. Finally, the internal deformation at the monitoring point of the Toudu landslide was calculated and the mechanism of the landslide was analyzed.
A Parameter Estimation Method of Shock Model Constructed with Phase-Type Distribution on the Condition of Interval Data
Authors: Wang Long , Li Yue , Qian Yanling , Luo Xu
Published: June 2020

The phase-type distribution (also known as PH distribution) has mathematical properties of denseness and closure in calculation and is, therefore, widely used in shock model constructions describing occurrence time of a shock or its damage. However, in the case of samples with only interval data, modeling with PH distribution will cause decoupling issues in parameter estimation. Aiming at this problem, an approximate parameter estimation method based on building PH distribution with dynamic order is proposed. Firstly, the shock model established by PH distribution and the likelihood function under samples with only interval data are briefly introduced. Then, the principle and steps of the method are introduced in detail, and the derivation processes of some related formulas are also given. Finally, the performance of the algorithm is illustrated by a case with three different types of distributions.
Antithrombotic Treatments in Patients with Chronic Coronary Artery Disease or Peripheral Artery Disease: A Systematic Review of Randomised Controlled Trials
Authors: Bauersachs Rupert , Wu Olivia , Briere Jean-Baptiste , Bowrin Kevin , Borkowska Katarzyna , Jakubowska Anna , Taieb Vanessa , Toumi Mondher , Huelsebeck Maria
Published: June 2020

Aims. Acetylsalicylic acid (ASA) is widely used for the prevention of atherothrombotic events in patients with chronic coronary artery disease (CAD) and peripheral artery disease (PAD), but the risk of vascular events remains high. We aimed at identifying randomised controlled trials (RCTs) on antithrombotic treatments in patients with chronic CAD or PAD. Methods. Searches were conducted on MEDLINE, EMBASE, and CENTRAL on March 1st, 2018. This systematic review (SR) uses a narrative synthesis to summarize the evidence for the efficacy and safety of antiplatelet and anticoagulant therapies in the population of both chronic CAD or PAD patients. Results. Four RCTs from 27 publications were included. Study groups included 15,603 to 27,395 patients. ASA alone was the most extensively studied (n=3); other studies included rivaroxaban with or without ASA (n=1), vorapaxar alone (n=1), and clopidogrel with (n=1) or without ASA (n=1). Clopidogrel alone and clopidogrel plus ASA compared to ASA presented similar efficacy with comparable safety profile. Rivaroxaban plus ASA significantly reduced the risk of the composite of cardiovascular death, myocardial infarction, and stroke compared to ASA alone, although major bleeding with rivaroxaban plus ASA increased. Conclusion. There is limited and heterogeneous evidence on the prevention of atherothrombotic events in patients with chronic CAD or PAD. Clopidogrel alone and clopidogrel plus ASA did not demonstrate superiority over ASA alone. A combination of rivaroxaban plus ASA may offer significant additional benefit in reducing cardiovascular outcomes, yet it may increase the risk of bleeding, compared to ASA alone.
Adaptive Double-Threshold Cooperative Spectrum Sensing Algorithm Based on History Energy Detection
Authors: Yu Shanshan , Liu Ju , Wang Jing , Ullah Inam
Published: June 2020

Spectrum sensing is one of the key technologies in the field of cognitive radio, which has been widely studied. Among all the sensing methods, energy detection is the most popular because of its simplicity and no requirement of any prior knowledge of the signal. In the case of low signal-to-noise ratio (SNR), the traditional double-threshold energy detection method employs fixed thresholds and there is no detection result when the energy is between high and low thresholds, which leads to poor detection performance such as lower detection probability and longer spectrum sensing time. To address these problems, we proposed an adaptive double-threshold cooperative spectrum sensing algorithm based on history energy detection. In each sensing period, we calculate the weighting coefficient of thresholds according to the SNR of all cognitive nodes; thus, the upper and lower thresholds can be adjusted adaptively. Furthermore, in a single cognitive node, once the current energy is within the high and low thresholds, we utilize the average energy of history sensing times to rejudge. To ensure the real-time performance, if the average history energy is still between two thresholds, the single-threshold method will be used for the end decision. Finally, the fusion center aggregates the detection results of each node and obtains the final cooperative conclusion through “or” criteria. Theoretical analysis and simulation results show that the algorithm proposed in this paper improved detection performance significantly compared with the other four different double-threshold algorithms.
Detection of Pulmonary Embolism with Gallium-68 Macroaggregated Albumin Perfusion PET/CT: An Experimental Study in Rabbits
Authors: Gültekin Aziz , Çayır Mustafa Çağdaş , Uğur Ayşe , Bir Ferda , Yüksel Doğangün
Published: June 2020

This study was designed to evaluate the accuracy of detecting pulmonary embolism (PE) using the Technegas SPECT/CT combined with 68Ga PET/CT in a rabbit model. One hour after artificial PE (n = 6) and sham (n = 6) models were created, Technegas SPECT/CT ventilation and 68Ga-MAA PET/CT perfusion scan (V/Q scan) were performed. Ventilation imaging was performed first on all cases. Technegas SPECT/CT and 68Ga-MAA PET/CT images were evaluated by a nuclear medicine physician who recorded the presence, number, and location of PE on a per-lobe basis. The sensitivity, specificity, and accuracy of Technegas SPECT/CT and 68Ga-MAA PET/CT for detecting PE were calculated using a histopathological evaluation as a reference standard. A total of 60 lung lobes were evaluated in 12 rabbits, and PE was detected in 20 lobes in V/Q scans and histopathological analysis. The overall sensitivity, specificity, and accuracy were 100%, 100%, and 100%, respectively, for both the Technegas SPECT/CT and 68Ga-MAA PET/CT V/Q scans. Technegas/68Ga-MAA V/Q scans have good sensitivity, specificity, and accuracy in the detection of PE in this animal model study.
Postendodontic Pain after Pulpotomy or Root Canal Treatment in Mature Teeth with Carious Pulp Exposure: A Multicenter Randomized Controlled Trial
Authors: Eghbal Mohammad Jafar , Haeri Ali , Shahravan Arash , Kazemi Ali , Moazami Fariborz , Mozayeni Mohammad Ali , Saberi Eshaghali , Samiei Mohammad , Vatanpour Mehdi , Akbarzade Baghban Alireza , Fazlyab Mahta , Parhizkar Ardavan , Ahmadi Mahboobe , Akbarian Rad Nazila , Bijari Shima , Bineshmarvasti Delaram , Davoudi Paria , Dehghan Roya , Dehghani Mandana , Ebrahimi Habibollah , Emami Nafiseh , Farajian Nafiseh , Fereidooni Rahim , Ghobadi Gelareh , Ghodrati Mostafa , Gohari Atefeh , Hashemi Azadeh , Hosseini Mohammadreza , Karami Elham , Kheirabadi Nasir , Kozegari Sepideh , Labaf Ghasemi Hadi , Majidi Alireza , Malekzadeh Parastu , Mehrabi Vahid , Mohammadi Mehrnush , Moradi Eslami Leila , Noghani Atefeh , Omatali Negin , Pourhatami Negar , Rahbani Nobar Behnam , Rahmani Saeid , Shafaq Parviz , Soofiabadi Sara , Teimoori Somaye , Vatandoost Farzaneh , Asgary Saeed
Published: June 2020

This equivalence, randomized, clinical trial aimed to compare the postoperative pain of root canal therapy (RCT) with pulpotomy with mineral trioxide aggregate (PMTA) or calcium-enriched mixture (PCEM) in permanent mature teeth. In seven academic centers, 550 cariously exposed pulps were included and randomly allocated into PMTA (n = 188), PCEM (n = 194), or RCT (n = 168) arms. Preoperative “Pain Intensity” (PI) on Numerical Rating Scale and postoperative PIs until day 7 were recorded. Patients’ demographic and pre-/intra-/postoperative factors/conditions were recorded/analysed. The arms were homogeneous in terms of demographics. The mean preoperative PIs were similar (P=0.998), the mean sum PIs recorded during 10 postoperative intervals were comparable (P=0.939), and the trend/changes in pain relief were parallel (P=0.821) in all study arms. The incidences of preoperative moderate-severe pain in RCT, PMTA, and PCEM arms were 56.5%, 55.7%, and 56.7%, which after 24 hours considerably decreased to 13.1%, 10.6%, and 12.9%, respectively (P=0.578). The time span of endodontic procedures was statistically different; RCT = 69.73, PMTA = 35.37, and PCEM = 33.62 minutes (P<0.001). Patients with greater preoperative pain, symptomatic apical periodontitis, or presence of PDL widening suffered more pain (P=0.002, 0.035, and 0.023, resp.); however, other pre-/intra-/postoperative factors/conditions were comparable. Pulpotomy with MTA/CEM and RCT demonstrate comparable and effective postoperative pain relief.
Gait Analysis after Total Knee Arthroplasty Assisted by 3D‐Printed Personalized Guide
Authors: Sun Maolin , Zhang Ying , Peng Yang , Fu Dejie , Fan Huaquan , He Rui
Published: June 2020

Background. With the development of three‐dimensional printing (3DP) technology, the patient‐specific instrumentation (PSI) has been widely applied in total knee arthroplasty (TKA). The purpose of this study was to compare the gait parameters of patients with 3DP personalized guide‐assisted and standard TKA. Methods. Retrospective analysis of the advanced knee OA cases in our hospital between June 2017 and June 2018 was conducted. 30 cases received 3DP personalized guide‐assisted TKA (group A), and 60 patients who underwent standard TKA during the same period were in group B and group C according to the computed tomography (CT) measurement results, each with 30 cases. Hip–knee–ankle angle (HKA), patella transverse axis‐femoral transepicondylar axis angle (PFA), and gait parameters were statistically analyzed. The function was assessed by Hospital for Specific Surgery (HSS) and Knee Society Score (KSS). Results. The mean follow‐up period was 12.3 months in the three groups. The knee max flexion angle at the swing phase of group A was larger than group B and group C (P < 0.05), there was no statistically significant difference in other gait parameters. The mean PFA of group A was smaller than that of group B and group C (P < 0.05). While, the HKA, HSS, and KSS scores of three groups showed no significant difference. Conclusion. 3DP personalized guide technology could improve the gait parameters after surgery, specifically reflected in the knee max flexion angle at the swing phase. It could also assist in the reconstruction of more accurate patellar tracking and rotational alignment in TKA, avoiding the occurrence of insufficient or excessive extorsion.
On the Location of Multiple Failure Slip Surfaces in Slope Stability Problems Using the Meshless SPH Algorithm
Authors: Li Liang , Zhai Ming , Ling Xianzhang , Chu Xuesong , Hu Bin , Cheng Yungming
Published: June 2020

The occurrence of multiple critical slip surfaces with equal importance in rehabilitating and reinforcing slopes has been frequently observed in geotechnical engineering practices. The simultaneous determination of these potential slip surfaces is, however, not trivial. This paper presents a methodology based on the smoothed particle hydrodynamics (SPH) approach, which can simultaneously determine multiple failure slip surfaces and the debris flow process without previous knowledge or trial‐and‐error processes, and this methodology is validated against a slope with the presence of multiple critical slip surfaces. The proposed methodology serves as an efficient and effective alternative approach to traditional approaches, which involve cumbersome treatments performed by engineers based on their subjective experiences. The multiple sources of failure slip surfaces in slope stability are equivalent to multiple sources of initiation of slope failure, and it is found that SPH can provide a direct and systematic tool for identifying multiple failure slip surfaces. However, some minor potential problems are also found with the use of the SPH method in actual applications.
Dimensional Analysis of Gas Holdup of Venturi Carbonation Reactor for Red Mud Processing
Authors: Xiao Yibin , Liu Yan , Zhao Zhibin , Zhang Ting’an , Li Ruibing
Published: June 2020

Gas holdup is an important parameter in the carbonation reaction for processing red mud. In this paper, for estimating the gas holdup of Venturi carbonation reactor, water model experiments were performed. The effects of superficial gas velocities, superficial liquid velocities, and liquid-to-solid and height-to-diameter ratio on the gas holdup are investigated. Through dimensional analysis using Buckingham π principle, a derivation of the empirical correlation is also proposed. The results indicate that gas holdup increases with the increase in gas velocity, with the decrease in liquid velocity, with the increase in liquid-to-solid ratio, and with the increase in height-to-diameter ratio. The calculated results from the empirical correlation agree well with the experimental data, which is important for designing a highly efficient Venturi reactor with a high temperature, high pressure, and three phases of gas, liquid, and solid.
Improving Maneuver Strategy in Air Combat by Alternate Freeze Games with a Deep Reinforcement Learning Algorithm
Authors: Wang Zhuang , Li Hui , Wu Haolin , Wu Zhaoxin
Published: June 2020

In a one-on-one air combat game, the opponent’s maneuver strategy is usually not deterministic, which leads us to consider a variety of opponent’s strategies when designing our maneuver strategy. In this paper, an alternate freeze game framework based on deep reinforcement learning is proposed to generate the maneuver strategy in an air combat pursuit. The maneuver strategy agents for aircraft guidance of both sides are designed in a flight level with fixed velocity and the one-on-one air combat scenario. Middleware which connects the agents and air combat simulation software is developed to provide a reinforcement learning environment for agent training. A reward shaping approach is used, by which the training speed is increased, and the performance of the generated trajectory is improved. Agents are trained by alternate freeze games with a deep reinforcement algorithm to deal with nonstationarity. A league system is adopted to avoid the red queen effect in the game where both sides implement adaptive strategies. Simulation results show that the proposed approach can be applied to maneuver guidance in air combat, and typical angle fight tactics can be learnt by the deep reinforcement learning agents. For the training of an opponent with the adaptive strategy, the winning rate can reach more than 50%, and the losing rate can be reduced to less than 15%. In a competition with all opponents, the winning rate of the strategic agent selected by the league system is more than 44%, and the probability of not losing is about 75%.
Properties and Applications of a New Chemical Grouting Material
Authors: Yang Xiaohua , Zheng Kunlong , Xu Lixiao , Liu Nieyangzi
Published: June 2020

The study investigates a new chemical grout by mixing the main agent, auxiliary agent, catalyst, foam stabilizer, solvent, and water, to treat the distress of railway tunnel. The orthogonal design was used to obtain 16 groups of grout proportion schemes, and reasonable proportion parameters were screened using laboratory and field tests. Additionally, this study included detailed research on the grout performance. The test results showed that the proportion schemes of groups 3, 4, and 15 grout were the most reasonable. In particular, for group 3, the viscosity is 663 MPa·s, the curing time is 119 s, the foaming capacity is 1589%, and the compressive strength is 20.16 MPa. For group 4, the viscosity is 663 MPa·s, the curing time is 137 s, the foaming capacity is 1809%, and the compressive strength is 17.76 MPa. For group 15, the viscosity is 281 MPa·s, the curing time is 98 s, the foaming capacity is 1173%, and the compressive strength is 26.79 MPa. Groups 4 and 15 grouts were used to treat the frost boiling and track bed subsidence in existed railway tunnels. Based on this, field monitoring showed that muddy water became clear water with an average depth of only 4 mm in the drainage ditch and that the irregular subsidence of the track bed was also solved after treatment. According to the aforementioned experimental research and analysis, it is proven that new grout not only exhibits a reasonable solidification time, high strength, and excellent waterproofing and impermeability with no pollution of the environment but also can be produced by a safe and convenient synthesis method. Group 4 is suitable for treating tunnel seepage, group 15 is suitable for structural reinforcement, and group 3 confers the advantages of seepage prevention, leakage stoppage, and reinforcement.
Association between Plasma Sestrin2 Levels and the Presence and Severity of Coronary Artery Disease
Authors: Kishimoto Yoshimi , Aoyama Masayuki , Saita Emi , Ikegami Yukinori , Ohmori Reiko , Kondo Kazuo , Momiyama Yukihiko
Published: June 2020

Aims. Atherosclerotic disease, such as coronary artery disease (CAD), is recognized to be associated with inflammation and oxidative stress. We investigated the association between CAD and plasma levels of sestrin2 which is one of the stress-inducible antioxidant proteins. Methods. We measured plasma sestrin2 levels in 304 patients undergoing elective coronary angiography. The severity of CAD was represented as the numbers of >50% stenotic coronary vessels and segments and the severity score. Results. CAD was found in 175 patients, of whom 73 had 1-vessel (1-VD), 59 had 2-vessel (2-VD), and 43 had 3-vessel disease (3-VD). Plasma sestrin2 levels were significantly higher in 175 patients with CAD than in 129 without CAD (median 16.4 vs. 14.2 ng/mL, P<0.05). A stepwise increase in sestrin2 levels was found depending on the number of >50% stenotic coronary vessels: 14.2 in CAD(-), 15.4 in 1-VD, 17.3 in 2-VD, and 17.7 ng/mL in3-VD (P<0.05). High sestrin2 level (>16.0 ng/mL) was present in 38% of patients with CAD(-), 47% of 1-VD, 66% of 2-VD, and 53% of 3-VD (P<0.005). Sestrin2 levels significantly, but weakly, correlated with the number of >50% stenotic segments and the severity score (rs=0.12 and rs=0.13, P<0.05). In the multivariate analysis, sestrin2 levels were a significant factor associated with CAD independent of atherosclerotic risk factors. The odds ratio for CAD was 1.79 (95%CI=1.09‐2.95) for high sestrin2 level of >16.0 ng/mL (P<0.025). Conclusions. Plasma sestrin2 levels in patients with CAD were found to be high and to be associated with the severity of CAD. High sestrin2 levels in patients with CAD may reflect a protective response against the progression of CAD.
A Novel Ensemble Credit Scoring Model Based on Extreme Learning Machine and Generalized Fuzzy Soft Sets
Authors: Xu Dayu , Zhang Xuyao , Hu Junguo , Chen Jiahao
Published: June 2020

This paper mainly discusses the hybrid application of ensemble learning, classification, and feature selection (FS) algorithms simultaneously based on training data balancing for helping the proposed credit scoring model perform more effectively, which comprises three major stages. Firstly, it conducts preprocessing for collected credit data. Then, an efficient feature selection algorithm based on adaptive elastic net is employed to reduce the weakly related or uncorrelated variables to get high-quality training data. Thirdly, a novel ensemble strategy is proposed to make the imbalanced training data set balanced for each extreme learning machine (ELM) classifier. Finally, a new weighting method for single ELM classifiers in the ensemble model is established with respect to their classification accuracy based on generalized fuzzy soft sets (GFSS) theory. A novel cosine-based distance measurement algorithm of GFSS is also proposed to calculate the weights of each ELM classifier. To confirm the efficiency of the proposed ensemble credit scoring model, we implemented experiments with real-world credit data sets for comparison. The process of analysis, outcomes, and mathematical tests proved that the proposed model is capable of improving the effectiveness of classification in average accuracy, area under the curve (AUC), H-measure, and Brier’s score compared to all other single classifiers and ensemble approaches.
An ES-MITC3 Finite Element Method Based on Higher-Order Shear Deformation Theory for Static and Free Vibration Analyses of FG Porous Plates Reinforced by GPLs
Authors: Tran The-Van , Tran Tuan-Duy , Hoa Pham Quoc , Nguyen-Thoi Trung , Tran Van Ke
Published: June 2020

An edge-based smoothed finite element method (ES-FEM) combined with the mixed interpolation of tensorial components technique (MITC) for triangular elements, named as ES-MITC3, was recently proposed to enhance the accuracy of the original MITC3 for analysis of plates and shells. In this study, the ES-MITC3 is extended to the static and vibration analysis of functionally graded (FG) porous plates reinforced by graphene platelets (GPLs). In the ES-MITC3, the stiffness matrices are obtained by using the strain smoothing technique over the smoothing domains created by two adjacent triangular elements sharing an edge. The effective material properties are variable through the thickness of plates including Young’s modulus estimated via the Halpin–Tsai model and Poisson’s ratio and the mass density according to the rule of mixture. Three types of porosity distributions and GPL dispersion pattern into the metal matrix are examined. Numerical examples are given to demonstrate the performance of the present approach in comparison with other existing methods. Furthermore, the effect of several parameters such as GPL weight fraction, porosity coefficient, porosity distribution, and GPL dispersion patterns on the static and free vibration responses of FG porous plates is discussed in detail.
Dynamic Behavior and Serviceability Analysis of a New Type of U‐Shaped Steel‐Concrete Composite Floor Slab
Authors: Lu Yaqin , Shang Hongkun , Li Zhengnong , Ma Kejian , Jiang Lan
Published: June 2020

A new type of U‐shaped steel‐concrete composite floor is analyzed in detail. The experimental test and finite element analysis of the floor are conducted to study the natural frequency and serviceability characteristics of the new composite floor structure. The natural frequency of the floor is measured under the environmental random vibration stimulating method, and the peak acceleration of the floor is measured under pedestrian‐induced load. The experimental test results show that the U‐shaped steel‐concrete composite floor has better antiseismic behaviors and meet the specified serviceability requirements. The finite element analysis results indicate the constraints have a great impact on the calculation results. The experimental tests and FEM results of the floor are compared based on the modal assurance criterion, and the results are in good agreement. The experimental test acceleration curves demonstrate that the peak values meet the requirements of Chinese specification.
Investor Sentiment in an Artificial Limit Order Market
Authors: Wei Lijian , Shi Lei
Published: June 2020

This paper examines the under/overreaction effect driven by sentiment belief in an artificial limit order market when agents are risk averse and arrive in the market with different time horizons. We employ agent-based modeling to build up an artificial stock market with order book and model a type of sentiment belief display over/underreaction by following a Bayesian learning scheme with a Markov regime switching between conservative bias and representative bias. Simulations show that when compared with classic noise belief without learning, sentiment belief gives rise to short-term intraday return predictability. In particular, under/overreaction trading strategies are profitable under sentiment beliefs, but not under noise belief. Moreover, we find that sentiment belief leads to significantly lower volatility, lower bid-ask spread, and larger order book depth near the best quotes but lower trading volume when compared with noise belief.
Experimental Study on Thermal Performance of a Bent Copper-Water Heat Pipe
Authors: Miao Shuangshuang , Sui Jiajia , Zhang Yulong , Yao Feng , Liu Xiangdong
Published: June 2020

Vapor-liquid phase change is regarded as an efficient cooling method for high-heat-flux electronic components. The copper-water bent heat pipes are particularly suited to the circumstances of confined space or misplaced heat and cold sources for high-heat-flux electronic components. In this paper, the steady and transient thermal performance of a bent copper-water heat pipe is studied based on a performance test system. The effects of cooling temperature, working conditions on the critical heat flux, and equivalent thermal conductivity have been examined and analyzed. Moreover, the influences of heat input and working conditions on the thermal response of a bent heat pipe have also been discussed. The results indicate that the critical heat flux is enhanced due to the increases in cooling temperature and the lengths of the evaporator and condenser. In addition, the critical heat flux is improved by extending the cooling length only when the operating temperature is higher than 50°C. The improvement on the equivalent thermal by increasing the heating length is more evident than that by increasing cooling length. It is also demonstrated by the experiment that the bent copper-water heat pipe can respond quickly to the variation of heat input and possesses superior transient heat transfer performance.