bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Eddy Simulation of Lean Mixed-Mode Combustion Assisted by Partial Fuel Stratification in a Spark-Ignition Engine
Authors: Xu Chao , Som Sibendu , Sjöberg Magnus
Published: December 2020

Lean operation is beneficial to spark-ignition engines due to the high thermal efficiency compared with conventional stoichiometric operation. Lean combustion can be significantly stabilized by the partial fuel stratification (PFS) strategy, in which a small amount of pilot injection is applied near the spark energizing timing in addition to main injections during intake. Furthermore, mixed-mode combustion, which makes use of end-gas autoignition following conventional deflagration-based combustion, can be further utilized to speed up the overall combustion. In this study, PFS-assisted mixed-mode combustion in a lean-burn direct injection spark-ignition (DISI) engine is numerically investigated using multi-cycle large eddy simulation (LES). To accurately represent the pilot injection characteristics, experimentally-derived spray morphology parameters are employed for spray modeling. A previously developed hybrid G-equation/well-stirred reactor model is extended to PFS conditions, to capture interactions of pilot injection, turbulent flame propagation and end-gas autoignition. The LES-based engine model is compared with Reynolds-averaged Navier-Stokes (RANS) based model, allowing an investigation of both mean and cycle-to-cycle variation (CCV) of combustion characteristics. Instantaneous spray and flame structures from simulations are compared with experiments. The LES-based model is finally leveraged to investigate impacts of fuel properties including heat of vaporization (HoV) and laminar flame speed (SL). It is shown that overall, the predicted mean pressure and heat release rate traces from both RANS and LES agree well with the experiment, while LES captures the CCV and the combustion phasing in the mass burned space much better than RANS. Predicted liquid fuel penetrations agree reasonably well with the experiment, both for RANS and LES. Detailed flame structures in the simulations also reveal the transition from a sooting flame to a lean premixed flame, which is consistent with experimental findings. LES is shown to capture more wrinkled and stretched flame fronts than RANS. Local sensitivity analysis further identifies the stronger combustion phasing sensitivity to SL compared with that to HoV, and the stronger sensitivity of autoignition heat release rate than deflagration. The results from this study demonstrate the high fidelity of the developed computational model based on LES, enabling future investigation of PFS-assisted mixed-mode combustion for different fuels and a wider range of operating conditions.
Impact of Geometric Compression Ratio and Variable Valve Actuation on Gasoline Compression Ignition in a Heavy-Duty Diesel Engine
Authors: Zhang Yu , Kumar Praveen , Tang Meng , Pei Yuanjiang , Merritt Brock , Traver Michael , Popuri Sriram
Published: December 2020

Gasoline compression ignition (GCI) is a promising powertrain solution to simultaneously address the increasingly stringent regulation of oxides of nitrogen (NOx) and a new focus on greenhouse gases. GCI combustion benefits from extended mixing times due to the low reactivity of gasoline, but only when held beneath the threshold of the high temperature combustion regime. The geometric compression ratio (GCR) of an engine is often chosen to balance the desire for low NOx emissions while maintaining high efficiency. This work explores the relationship between GCR, variable valve actuation (VVA) and emissions when using GCI combustion strategies. The test article was a Cummins ISX15 heavy-duty diesel engine with an unmodified production air and fuel system. The test fuel was an ethanol-free gasoline with a market-representative research octane number (RON) of 91.4–93.2. In the experimental investigation at 1375 rpm/10 bar BMEP, three engine GCRs were studied, including 15.7, 17.3, and 18.9.

Across the three GCRs, GCI exhibited a two-stage combustion process enabled through a split injection strategy. When keeping both NOx and CA50 constant, varying GCR from 15.7 to 18.9 showed only a moderate impact on engine brake thermal efficiency (BTE), while its influence on smoke was pronounced. At a lower GCR, a larger fraction of fuel could be introduced during the first injection event due to lower charge reactivity, thereby promoting partially-premixed combustion and reducing smoke. Although increasing GCR increased gross indicated thermal efficiency (ITEg), it was also found to cause higher energy losses in friction and pumping. In contrast, GCI performance showed stronger sensitivity towards EGR rate variation, suggesting that air-handling system development is critical for enabling efficient and clean low NOx GCI combustion.

To better utilize gasoline’s lower reactivity, an analysis-led variable valve actuation investigation was performed at 15.7 GCR and 1375 rpm/10 bar BMEP. The analysis was focused on using an early intake valve closing (EIVC) approach by carrying out closed-cycle, 3-D CFD combustion simulations coupled with 1-D engine cycle analysis. EIVC was shown to be an effective means to lengthen ignition delay and promote partially-premixed combustion by lowering the engine effective compression ratio (ECR). By combining EIVC with a tailored fuel injection strategy and properly developed thermal boundary conditions, simulation predicted a 2.3% improvement in ISFC and 47% soot reduction over the baseline IVC case while keeping NOx below the baseline level.
Atmospheric sound propagation in a stratified moving media: Application of the semi analytic finite element method
Authors: Kirby Ray
Published: December 2020

This article presents a finite element based solution of the exact governing wave equation for a stratified inhomogeneous moving media. The model is applied to a two dimensional range independent problem in outdoor sound propagation in which the ground is treated as perfectly reflecting. The sound pressure field is expanded as a sum over eigenmodes propagating in the range direction, and the semi analytic finite element method is used to solve the governing eigenequation. This delivers faster solution times when compared to traditional finite element based methods while simultaneously accommodating continuous variations in fluid properties in the vertical direction. In principle, the method converges toward the exact solution and so delivers a benchmark method for range independent problems. The method is shown to provide excellent agreement with analytic solutions, and good convergence is demonstrated for more complex problems, including temperature inversions and logarithmic profiles for wind velocity. Finally, qualitative comparisons are made against infrasound predictions, including those obtained using wide angle parabolic equations. The method is shown to provide a focussed image of the sound pressure field over large distances, as well as to reproduce multiple turning points and ground interactions.
Semi-supervised audio-driven TV-news speaker diarization using deep neural embeddings
Authors: Tsipas Nikolaos , Vrysis Lazaros , Konstantoudakis Konstantinos , Dimoulas Charalampos
Published: December 2020

In this paper, an audio-driven, multimodal approach for speaker diarization in multimedia content is introduced and evaluated. The proposed algorithm is based on semi-supervised clustering of audio-visual embeddings, generated using deep learning techniques. The two modes, audio and video, are separately addressed; a long short-term memory Siamese neural network is employed to produce embeddings from audio, whereas a pre-trained convolutional neural network is deployed to generate embeddings from two-dimensional blocks representing the faces of speakers detected in video frames. In both cases, the models are trained using cost functions that favor smaller spatial distances between samples from the same speaker and greater spatial distances between samples from different speakers. A fusion stage, based on hypotheses derived from the established practices in television content production, is deployed on top of the unimodal sub-components to improve speaker diarization performance. The proposed methodology is evaluated against VoxCeleb, a large-scale dataset with hundreds of available speakers and AVL-SD, a newly developed, publicly available dataset aiming at capturing the peculiarities of TV news content under different scenarios. In order to promote reproducible research and collaboration in the field, the implemented algorithm is provided as an open-source software package.
Development and Validation of an
In Vitro
Resazurin-Based Susceptibility Assay against
Madurella mycetomatis
Authors: Abd Algaffar S. O. , Verbon A. , van de Sande W. W. J. , Khalid S. A.
Published: December 2020

We present an
in vitro
susceptibility assay for
Madurella mycetomatis
hyphae using resazurin for endpoint reading. Using this assay, reproducible MICs were obtained for amphotericin B, itraconazole, voriconazole, posaconazole, terbinafine, and micafungin.
The Pharmacodynamic-Toxicodynamic Relationship of AUC and
C
max
in Vancomycin-Induced Kidney Injury in an Animal Model
Authors: Avedissian Sean N. , Pais Gwendolyn , Liu Jiajun , O’Donnell J. Nicholas , Lodise Thomas P. , Neely Michael , Prozialeck Walter C. , Lamar Peter C. , Becher Leighton , Scheetz Marc H.
Published: December 2020

Vancomycin induces exposure-related acute kidney injury. However, the pharmacokinetic-toxicodynamic (PK-TD) relationship remains unclear.
Efficacy of Rezafungin in Prophylactic Mouse Models of Invasive Candidiasis, Aspergillosis, and
Pneumocystis
Pneumonia
Authors: Miesel Lynn , Cushion Melanie T. , Ashbaugh Alan , Lopez Santiago R. , Ong Voon
Published: December 2020

Antifungal prophylaxis is recommended to prevent invasive fungal disease caused by
Candida
spp.,
Aspergillus
spp., and
Pneumocystis jirovecii
in patients at risk for opportunistic infections, such as allogeneic blood or marrow transplant recipients, patients with hematological disease undergoing chemotherapy, or patients on immunosuppressive therapies. Current approaches to antifungal prophylaxis require multiple agents to cover these key fungi.
Molecular Characterization of Baseline
Enterobacterales
and Pseudomonas aeruginosa Isolates from a Phase 3 Nosocomial Pneumonia (ASPECT-NP) Clinical Trial
Authors: Castanheira Mariana , Johnson Matthew G. , Yu Brian , Huntington Jennifer A. , Carmelitano Patricia , Bruno Christopher , Rhee Elizabeth G. , Motyl Mary
Published: December 2020

We evaluated β-lactam-resistant baseline
Enterobacterales
species and
Pseudomonas aeruginosa
lower respiratory tract isolates collected during the ASPECT-NP phase 3 clinical trial evaluating the safety and efficacy of ceftolozane-tazobactam compared with meropenem for the treatment of nosocomial pneumonia in ventilated adults. Isolates were subjected to whole-genome sequencing, quantitative real-time PCR for quantification of the expression levels of β-lactamase and efflux pump genes, and Western blot analysis for the detection of OprD (
P. aeruginosa
only).
Systematic Evaluation of Mycobacterium tuberculosis Proteins for Antigenic Properties Identifies Rv1485 and Rv1705c as Potential Protective Subunit Vaccine Candidates
Authors: Wang Yaguo , Li Zihui , Wu Shucai , Fleming Joy , Li Chuanyou , Zhu Guofeng , Chen Bo , Ren Baiguang , Wang Xingyun , Du Boping , Li Pingjun , Hu Peilei , Yang Juwang , Liu Yi , Zhou Chongchen , Zhang Xian-En , Bi Lijun , Zhang Hongtai , Yang Junmei , Zhang Zongde
Published: December 2020

The lack of efficacious vaccines against
Mycobacterium tuberculosis
(MTB) infection is a limiting factor in the prevention and control of tuberculosis (TB), the leading cause of death from an infectious agent. Improvement or replacement of the BCG vaccine with one that reliably protects all age groups is urgent.
Annexin A1 Attenuates Neutrophil Migration and IL-6 Expression through Fpr2 in a Mouse Model of Streptococcus suis-Induced Meningitis
Authors: Ni Chengpei , Gao Song , Zheng Yuling , Liu Peng , Zhai Yajie , Huang Wenhua , Jiang Hua , Lv Qingyu , Kong Decong , Jiang Yongqiang
Published: December 2020

Streptococcus suis
serotype 2 is a crucial pathogenic cause of bacterial meningitis, a life-threatening disease with neurological sequelae and high rates of mortality. Inflammation triggered by
S. suis
infection must be precisely regulated to prevent further tissue damage.
The Transcription Regulator and c-di-GMP Phosphodiesterase PdeL Represses Motility in
Escherichia coli
Authors: Yilmaz Cihan , Rangarajan Aathmaja Anandhi , Schnetz Karin
Published: December 2020

Bacteria adopt different lifestyles depending on their environment and physiological conditions. In
Escherichia coli
and other enteric bacteria, the transition between the motile and the sessile states is controlled at multiple levels from the regulation of gene expression to the modulation of various processes by the second messenger c-di-GMP as a signaling molecule.
Immunologic Testing for SARS-CoV-2 Infection from the Antigen Perspective
Authors: Li Dandan , Li Jinming
Published: December 2020

Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally as a severe pandemic. SARS-CoV-2 infection stimulates antigen-specific antibody responses.
Restoring Balance to the Outer Membrane: YejM’s Role in LPS Regulation
Authors: Simpson Brent W. , Douglass Martin V. , Trent M. Stephen
Published: December 2020

Gram-negative bacteria produce an asymmetric outer membrane (OM) that is particularly impermeant to many antibiotics and characterized by lipopolysaccharide (LPS) exclusively at the cell surface. LPS biogenesis remains an ideal target for therapeutic intervention, as disruption could kill bacteria or increase sensitivity to existing antibiotics.
Interactions of the Nipah Virus P, V, and W Proteins across the STAT Family of Transcription Factors
Authors: Keiffer Timothy R. , Ciancanelli Michael J. , Edwards Megan R. , Basler Christopher F.
Published: December 2020

How Nipah virus (NiV) antagonizes innate immune responses is incompletely understood. The P gene of NiV encodes the P, V, and W proteins.
Introducing an innovative model of acute paediatric mental health and addictions care to paediatric emergency departments: a protocol for a multicentre prospective cohort study
Authors: Freedman Stephen , Thull-Freedman Jennifer , Lightbody Teresa , Prisnie Kassi , Wright Bruce , Coulombe Angela , Anderson Linda M , Stang Antonia S , Mikrogianakis Angelo , VanRiper Lindy , Stubbs Michael , Newton Amanda
Published: December 2020

Introduction

Children and youth with mental health and addiction crises are a vulnerable patient group that often are brought to the hospital for emergency department care. We propose to evaluate the effect of a novel, acute care bundle that standardises a patient-centred approach to care.

Methods and analysis

Two paediatric emergency departments in Alberta, Canada are involved in this prospective, pragmatic, 29-month interventional quasi-experimental study. The acute care bundle comprises three components, applied when appropriate: (1) assessing self-harm risk at triage using the Ask Suicide-Screening Questionnaire (ASQ) to standardise the questions administered, enabling risk stratification; (2) use of the HEADS-ED (Home, Education, Activities/peers, Drug/alcohol, Suicidality, Emotions and behaviour, Discharge Resources) to focus mental health evaluations for those who screen high risk on the ASQ; and (3) implementation of a Choice And Partnership Approach to enable shared decision making in care following the emergency department visit. The overarching goal is to deliver the right care at the right place and time for the patients. The study design involves a longitudinal collection of data 12 months before and after the introduction of the bundle and the use of quality improvement strategies such as Plan-Do-Study-Act cycles during a 5-month run-in period to test and implement changes. The primary study end-point is child/youth well-being 1 month after the emergency department visit. Secondary outcomes include family functioning, child/youth well-being at 3 and 6 months, satisfaction with emergency department care, and health system outcomes (hospital admissions, length of emergency department stays, emergency department revisits).

Ethics and dissemination

The study is registered atwww.ClinicalTrials.govand has received ethics and operational approvals from study sites. The results of the study will be reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement. Results will be shared broadly with key policy and decision makers and disseminated in peer-reviewed academic journals and presentations at conferences.

Trial registration number

NCT04292379.
Implementation of the CMS-EXO-17-015 analysis in the MadAnalysis 5 framework (leptoquark and dark matter with one muon, one jet and missing transverse energy; 77.4 fb−1)
Authors: Fuks Benjamin , Jueid Adil
Published: December 2020

We present an implementation of the CMS-EXO-17-015 analysis in the MadAnalysis 5 framework. The analysis targets a search for dark matter in a channel in which it originates from the production and decay of a pair of scalar leptoquarks. This search considers a luminosity [Formula: see text] of CMS data collected in 2016 and 2017, in proton-proton collisions at a center-of-mass energy of 13 TeV. The final state signature is comprised of one isolated highly-energetic muon, one jet with a large transverse momentum and a significant amount of missing transverse energy. We validate our implementation in MadAnalysis 5 for a specific leptoquark/dark matter benchmark scenario. In particular, we compare predictions obtained with MadAnalysis 5 with the official CMS results for various kinematical distributions relevant for the CMS-EXO-17-015 analysis, as well as detailed cut-flow tables. We have found an excellent agreement.
A Proposed 2.45 GHz RF-Symmetrical DC Energy Harvester for the Power Unit in the Biosensor
Authors: Daoud Maissa , Mnif Hassene , Ghorbel Mohamed
Published: December 2020

This paper presents the proposed inductorless RF-Symmetrical DC energy harvester for low power biosensor transceiver. It is designed to benefit from the symmetrical power supply to reduce the low noise amplifier power consumption of the biosensor reception part. Several techniques are used in this work to design a high efficiency RF-DC harvester with minimum number of stages as: the use of the diode-connected CMOS transistor which its bulk is related to its drain to minimize the leakage current and to reduce the threshold voltage for more energy harvesting, and the use of the Greinacher voltage multiplier to decrease the effect of the voltage drop between the drain and the source of the CMOS transistor. The impedance matching circuit between the antenna and the energy converter is designed without inductors to gain more power and space. Conceived under the 0.18[Formula: see text][Formula: see text]m TSMC MOS technology with only four stages, the harvester simulation results show a high efficiency of 56% which the minimal voluntary received power is about 0dBm required by the IEEE 802.15.4 standard. The symmetrical DC output voltage is of 1/[Formula: see text]1V as expected in the specifications. Therewith, its delivered power is equal to 1mW for storage capacity about 20[Formula: see text]nF.
AdaBoosted Extra Trees Classifier for Object-Based Multispectral Image Classification of Urban Fringe Area
Authors: Patel Alpesh M. , Suthar Anil
Published: December 2020

In the past decade, it is proven that satellite image classification using an object-based technique is better than the standard pixel-based technique. With the increasing need for classifying multispectral satellite images for urban planning, the accuracy of the classification becomes a significant performance parameter. Object-based classification (OBC) is a technique in which group of pixels having similar spectral properties, called objects, are generated using image segmentation and then these objects are classified based on their attributes. In this paper, the combination of a multiclass AdaBoost algorithm with extra trees classifier (ETC) is proposed with higher prediction accuracy for the OBC of the urban fringe area. The performance of the AdaBoost algorithm is found to be better in terms of classification accuracy than benchmarked SVM and RF classifiers for OBC. These classification methods were applied to IRS-R2 LISS IV data. The AdaBoosted extra trees classifier (ABETC) has demonstrated the highest accuracy with overall accuracy (OA) of 88.47% and a kappa coefficient of 0.85. The computational time of the ABETC is found to be much smaller than the RF algorithm. In detail, the sensitivity of the classifiers was investigated using stratified random sampling with various sample sizes.
On some properties of sticky Brownian motion
Authors: Zhang Haoyan , Jiang Pingping
Published: December 2020

In this paper, we investigate a generalization of Brownian motion, called sticky skew Brownian motion, which has two interesting characteristics: stickiness and skewness. This kind of processes spends a lot more time at its sticky points so that the time they spend at the sticky points has positive Lebesgue measure. By using time change, we obtain an SDE for the sticky skew Brownian motion. Then, we present the explicit relationship between symmetric local time and occupation time. Some basic probability properties, such as transition density, are studied and we derive the explicit expression of Laplace transform of transition density for the sticky skew Brownian motion. We also consider the first hitting time problems over a constant boundary and a random jump boundary, respectively, and give some corollaries based on the results above.
Perturbation analysis of low-rank matrix stable recovery
Authors: Huang Jianwen , Wang Jianjun , Zhang Feng , Wang Hailin , Wang Wendong
Published: December 2020

In this paper, we bring forward a completely perturbed nuclear norm minimization method to tackle a formulation of completely perturbed low-rank matrices recovery. In view of the matrix version of the restricted isometry property (RIP) and the Frobenius-robust rank null space property (FRNSP), this paper extends the investigation to a completely perturbed model taking into consideration not only noise but also perturbation, derives sufficient conditions guaranteeing that low-rank matrices can be robustly and stably reconstructed under the completely perturbed scenario, as well as finally presents an upper bound estimation of recovery error. The upper bound estimation can be described by two terms, one concerning the total noise, and another regarding the best [Formula: see text]-approximation error. Specially, we not only improve the condition corresponding with RIP, but also ameliorate the upper bound estimation in case the results reduce to the general case. Furthermore, in the case of [Formula: see text], the obtained conditions are optimal.
Results on uniquely colorable digraphs
Authors: Dhanalakshmi K. , Germina K. A. , Jerline J. Amalorpava , Raj L. Benedict Michael
Published: December 2020

Sampathkumar [F. Harary, Graph Theory (Addison-Wesley, Reading, MA, 1969)] defined the coloring of a digraph [Formula: see text] as a coloring of its vertices by the following rule: Let [Formula: see text] be an arc in [Formula: see text]. If the tail [Formula: see text] is colored first, then the head [Formula: see text] should receive a color different from that of [Formula: see text]. But, if [Formula: see text] is colored first, then [Formula: see text] may or may not receive the color of [Formula: see text]. The dichromatic number [Formula: see text] of a digraph [Formula: see text] is the minimum number of colors needed for coloring of a digraph [Formula: see text]. In this paper, we obtain some results on uniquely colorable digraphs and Nordhaus–Gaddum type results for digraphs.
Children's Socioemotional Development Across Cultures
Authors: Keller Heidi
Published: December 2020

The development of socioemotional competencies is central for children's development in general. Infants are equipped with basic predispositions to acquire environmental information. However, contexts and cultures differ with respect to their emphasis on particular developmental domains. Two developmental pathways for which research evidence is available have been characterized: the Western middle-class perspective and the perspective of rural traditionally living farming families. Infants have different social experiences with respect to their caregivers, their behaviors, and their social regulation. The developmental focus of Western middle-class children is on individualistic agency, which implies that socioemotional development is subordinated to self-development. The developmental focus of the rural traditionally living farmer child is on social connectedness and social responsibility. Self-development is part of the development of communal agency. This review discusses the ethical implications of regarding the Western middle-class pathway as universal and normative and emphasizes the need to consider different pathways as normative.
A Glass Half Full and Half Empty: The State of the Science in Early Childhood Prevention and Intervention Research
Authors: Fisher Philip A. , Barker Tyson V. , Blaisdell Kellyn N.
Published: December 2020

In this article, we review the field of early childhood prevention and intervention science, describe noteworthy achievements over the past half-century by researchers in this area, and comment on current issues in need of ongoing attention. Although there have been many successes and noteworthy achievements in the field, in recent decades there has been little progress toward population-level impacts of early intervention. As such, novel empirical methods and revised standards of evidence are needed to complement (rather than replace) existing best practices for the development, implementation, evaluation, and scaling of effective programs.
Gut Colonization Mechanisms of Lactobacillus and Bifidobacterium: An Argument for Personalized Designs
Authors: Xiao Yue , Zhai Qixiao , Zhang Hao , Chen Wei , Hill Colin
Published: December 2020

Lactobacillus and Bifidobacterium spp. are best understood for their applications as probiotics, which are often transient, but as commensals it is probable that stable colonization in the gut is important for their beneficial roles. Recent research suggests that the establishment and persistence of strains of Lactobacillus and Bifidobacterium in the gut are species- and strain-specific and affected by natural history, genomic adaptability, and metabolic interactions of the bacteria and the microbiome and immune aspects of the host but also regulated by diet. This provides new perspectives on the underlying molecular mechanisms. With an emphasis on host–microbe interaction, this review outlines how the characteristics of individual Lactobacillus and Bifidobacterium bacteria, the host genotype and microbiome structure,diet, and host–microbe coadaptation during bacterial gut transition determine and influence the colonization process. The diet-tuned and personally tailored colonization can be achieved via a machine learning prediction model proposed here.
Review—Lithium Plating Detection Methods in Li-Ion Batteries
Authors: Janakiraman Umamaheswari , Garrick Taylor R. , Fortier Mary E.
Published: December 2020

Lithium-ion batteries (LiB) offer a low-cost, long cycle-life and high energy density solution to the automotive industry. There is a growing need of fast charging batteries for commercial application. However, under certain conditions of high currents and/or low temperatures, the chance for Li plating increases. If the anode surface potential falls below 0 V vs Li/Li+, the formation of metallic Li is thermodynamically feasible. Therefore, determination of accurate Li plating curve is crucial in estimating the boundary conditions for battery operation without compromising life and safety. There are various electrochemical and analytical methods that are employed in deducing the Li plating boundary of the Li-ion batteries. The present paper reviews the common test methods and analysis that are currently utilized in Li plating determination. Knowledge gaps are identified, and recommendations are made for the future development in the determination and verification of Li plating curve in terms of modeling and analysis.
Superconformal Cobalt Electrodeposition with a Hydrogen Evolution Reaction Suppressing Additive
Authors: Kang Jungkyu , Sung Minjae , Byun Jinuk , Kwon Oh Joong , Kim Jae Jeong
Published: December 2020

In this study, superconformal cobalt filling of submicron trenches by electrodeposition is investigated in the presence of 2-mercaptobenzimidazole (MBI), which suppresses both cobalt deposition and the hydrogen evolution reaction (HER). The mechanism through which this single additive enables superconformal cobalt filling is investigated. The formation and breakdown of the suppression layer are characterized by linear sweep voltammetry and chronoamperometry. The convection-driven local concentration of MBI exerts different suppressing effects on cobalt reduction and the HER, leading to a change in the deposition rate and the current efficiency of cobalt. These phenomena induce a deposition rate differential between the top and bottom of the submicron trench, enabling bottom-up cobalt filling with a V-shape profile.
A Piecewise Yield Failure Criterion including the Critical State for Brittle Rock
Authors: Zhang Jing , Ren Fengyu , Ouyang Zhihua , Liu Huan
Published: December 2020

The critical state of rock is an important index for measuring the changes in rock characteristics. However, this state is not unique because of the different researcher assumptions. Based on the theory of the partial differential equation proposed by Vutukuri, according to Mohr’s envelope, a piecewise yield failure criterion (referred to as the Mohr–Wedge criterion), including the critical state for brittle rock, is obtained by introducing the wedge model to solve this equation. The Mohr–Wedge (M–W) criterion consisting of nonlinear and linear components includes the critical state for brittle rock. When the minimum principal stress σ3 is lower than the confining pressure σk, the maximum principal stress σ1 varies nonlinearly with σ3; otherwise, σ1 varies linearly with σ3. This variation conforms to rock deformation features under triaxial compression. In this study, we investigate the rationality of this critical state by an analogy method and illustrate that the critical state mentioned in this criterion is related to the microcracks in the potential failure zone of the rock. Alternatively, the primary object of this study is to reveal the applicability of predicting the yield state for this criterion. The method used in our study is compared to the Mohr–Coulomb (M‐C) criterion, the Hoek–Brown (H‐B) criterion, and the Exponential (Exp.) criterion by the yield surfaces on the deviatoric plane. Notably, there is a vertex consistent region for the four criteria, but except for this region, the yield state of rock predicted by the four criteria is quite different, depending on the extent of the parameters for the criteria and the magnitude of the slopes of the yield surfaces. The results show that the M‐W criterion has certain applicability for predicting the rock yield state by using the multiple data of rock triaxial compression tests in the published literature.
Astragaloside and/or Hydroxysafflor Yellow A Attenuates Oxygen‐Glucose Deprivation‐Induced Cultured Brain Microvessel Endothelial Cell Death through Downregulation of PHLPP‐1
Authors: Cao Jinyi , Wang Kai , Lei Lu , Bai Lu , Liang Ruimin , Qiao Yi , Duan Jialin , Gao Kai , Cao Shanshan , Zhao Chao , Yang Zhifu
Published: December 2020

The incidence of ischemic stroke, a life‐threatening condition in humans, amongst Asians is high and the prognosis is poor. In the absence of effective therapeutics, traditional Chinese medicines have been used that have shown promising results. It is crucial to identify traditional Chinese medicine formulas that protect the blood‐brain barrier, which is damaged by an ischemic stroke. In this study, we aimed to elucidate such formulas. Brain microvascular endothelial cells (BMECs) were used to establish an in vitro ischemia‐reperfusion model for oxygen‐glucose deprivation (OGD) experiments to evaluate the function of two traditional Chinese medicines, namely, astragaloside (AS‐IV) and hydroxysafflor yellow A (HSYA), in protecting against BMEC. Our results revealed that AS‐IV and HSYA attenuated the cell loss caused by OGD by increasing cell proliferation and inhibiting cell apoptosis. In addition, these compounds promoted the migration and invasion of BMECs in vitro. Furthermore, we found that BMECs rescued by AS‐IV and HSYA could be functionally activated in vitro, with AS‐IV and HSYA showing synergetic effects in rescuing BMECs survival in vitro by reducing the expression of PHLPP‐1 and activating Akt signaling. Our results elucidated the potential of AS‐IV and HSYA in the prevention and treatment of stroke by protecting against cerebral ischemia‐reperfusion injury.
Evaluation of the Therapeutic Effect of Traditional Chinese Medicine on Osteoarthritis: A Systematic Review and Meta-Analysis
Authors: Wang Lin , Zhang Xiao-Fei , Zhang Xue , Guo Dong-Yan , Duan Yu-Wei , Wang Zhi-Chao , Pei Li-Shan , Ru Han , Cheng Jiang-Xue , Shi Ya-Jun , Zou Jun-Bo
Published: December 2020

Background. Osteoarthritis (OA) is a common degenerative disease of bone and joint characterized by the damage of articular cartilage and hypertonia, which often occurs in the middle-aged and elderly. Traditional Chinese medicine (TCM) therapy, including acupuncture (ACU), oral administration, and external use of traditional Chinese medicines (TCMs), can significantly improve the therapeutic effect on OA and reduce the occurrence of side effects. We provide a latest meta-analysis on the treatment of OA with TCM. Materials and Methods. In the electronic database, appropriate articles without language restrictions on keywords were selected until August 1, 2019. All trajectories are screened according to certain criteria. The quality of qualified research was also assessed. We have made a detailed record of the results of the measurement. Meta-analysis was carried out with Revman 5.3 software. Results. Forty-four articles involving 4014 patients (2012 cases in the experimental group and 2002 cases in the control group) with OA were selected. This article focuses on the study of the treatment of OA by using the general mode of TCM. The quality evaluation included in the study was evaluated independently according to the Cochrane intervention system evaluation manual. In this meta-analysis, 68.18% of the literature correctly described the conditions for the generation of random assignment sequences, only 6.82% of the literature correctly mentioned the hidden details of allocation, and all studies mentioned randomly assigned participants. Compared with Western medicine, the total effective rate (TER) of OA treatment in TCM was significantly increased and the recurrence rate (RR) was significantly decreased (

P
<
0.00001

). In addition, the experimental group was also superior to the control group in terms of the indicators of joint activity function, inflammatory factor content, and various indicators affecting bone metabolism. It can be showed by the network analysis diagram that Aconiti Radix, Achyranthis Bidentatae Radix, and other TCMs can inhibit inflammatory stimulation and relieve the pain symptoms of patients with OA. ACU at Yinlingquan, Xiyan, and other acupoints can effectively improve the clinical symptoms of patients with OA. Conclusion. TCM therapy in treatment of patients with OA could effectively restore joint function, enhance the TER, and reduce RR. However, the results of this study should be handled with care due to the limitations existing. Some rigorous randomized controlled trials (RCTs) are needed to confirm these findings.
Systematical Identification of the Protective Effect of Danhong Injection and BuChang NaoXinTong Capsules on Transcription Factors in Cerebral Ischemia Mice Brain
Authors: Xu Jing , Wang Tingting , Guo Feifei , Ji Enhui , Zhang Yi , Wu Hongwei , Tang Shihuan , Wei Junying , Yang Hongjun
Published: December 2020

Cerebral ischemia has led to a high rate of both disability and mortality with massive healthcare costs. Although transcriptional regulation is typically mediated by different combinations of TFs, a combined regulatory unit to synergistically activate transcription has remained unclear in cerebral ischemia, especially in different drug treatments. In this study, TFs alterations after 6 h cerebral ischemic injury and repair were performed by a concatenated tandem array of consensus transcription factor response elements (catTFREs), and vital TFs were obtained by TFs-target imbalanced network. Drug intervention used Danhong injection (DHI) and BNC (BuChang NaoXinTong Capsules), which has been widely prescribed in Chinese herb medicine for the treatment of cerebrovascular and cardiovascular diseases. There were 198 TFs identified after 6 h MCAO operation, and six TFs (Sox2, Smad3, FoxO1, Creb1, Egr,1 and Smad4) were considered as critical TFs in response to cerebral ischemia. Moreover, Smad3 was identified as a hub TF among six vital TFs, and the transcription activity of Smad3 was further verified. These 6 TFs were all reversed by DHI or BNC, indicating different medications may regulate different transcription factors through TF synergy. Moreover, validation results indicated that Smad3 was a putative target TF for DHI and BNC-mediated protection against cerebral ischemia. The observations of the present study provide a fresh understanding of biomolecules and possible new avenues for therapeutic interventions, in addition to the new intervention pattern for different treatments for ischemia stroke.
Cyber Security and Key Management Issues for Internet of Things: Techniques, Requirements, and Challenges
Authors: Faisal Mohammad , Ali Ikram , Khan Muhammad Sajjad , Kim Junsu , Kim Su Min
Published: December 2020

Internet of Things-based environments pose various challenges due to their anytime/anywhere computing, and the efficient cryptographic based key management is one of the major challenges in Internet of Things. The key management life cycle consists of initialization, key generation, key registration, key backup, key update, key recovery, and key revocation. Our contribution in this paper is to summarize the state-of-the-art key management schemes and techniques in different scenarios, such as mobile ad hoc networks, wireless sensor networks, and the Internet of Things environments. Further different issues related specifically to the Internet of Things environment are discussed and the causes and effects pertaining to the security breach for Internet of Things are identified. Furthermore, in this research work, we develop a novel permutation of threshold and identity-based key management schemes for the Internet of Things environment and have proposed future directions to counteract the attacks on confidentiality, integrity, authentication, and availability of security services in the Internet of Things environment and identified the two key management schemes, that is, identity and threshold schemes for Internet of Things, to resolve Internet of Things key management issues and maximum possible security services effective implementation. We evaluate our scheme with the help of mathematical and statistical techniques.
Genetic Programming Method for Satellite System Topology and Parameter Optimization
Authors: Li Jinhui , Dong Yunfeng , Xu Ming , Li Hongjue
Published: December 2020

In this paper, a genetic programming method for satellite system design is proposed to simultaneously optimize the topology and parameters of a satellite system. Firstly, the representation of satellite system design is defined according to the tree structure. The genetic programming method is designed based on that representation. Secondly, according to the tree structure of different satellite schemes, different multiscale satellite models are established, in which various physical fields couple together. Then, an evaluation system is also proposed to test the performances of different satellite schemes. Finally, the application to the design of an earth observation satellite demonstrates the effectiveness of the proposed method.
Improved Generalized Predictive Control for High-Speed Train Network Systems Based on EMD-AQPSO-LS-SVM Time Delay Prediction Model
Authors: Kong Xiangyu , Zhang Tong
Published: December 2020

Various control signals of high-speed trains (HSTs) are transmitted through the train communication network. However, the time delay generated during the transmission will cause a significant threat to the stability and safe operation of the train. To overcome the effect of time delay on the train control system, based on empirical mode decomposition (EMD) and adaptive quantum particle swarm optimization (AQPSO) algorithms, a least squares support vector machine (LS-SVM) time delay prediction model is proposed in this paper. The EMD algorithm is used to decompose the time delay sequence into several subsequences, which emphasizes the different local characteristics of the time delay sequence. By improving the calculation method about the successful value of particle iteration, an AQPSO algorithm with adaptive contraction-expansion coefficient is designed to optimize the parameters of different LS-SVM models for predicting each time delay component, which improves the prediction accuracy of network delay. Further, based on actor-critic reinforcement learning algorithm, an improved generalized predictive control method is proposed for the train network system. The actor-critic network is used to predict the future output of the system, and the recursive least squares identification algorithm with the variable forgetting factor is adopted to identify the future system model parameters. Combined with the time delay predicted accurately, the control quantity is sent in advance according to the properly arranged time series, which compensates efficiently the influence of the time delay on the control system. Simulation results show that compared with other control methods, the proposed method has better robustness and stability, which ensures the safe operation of high-speed trains under various working conditions.
YQWY Decoction Improves Myocardial Remodeling via Activating the IL‐10/Stat3 Signaling Pathway
Authors: Li He , Gong Zhi-Jun , He Yun , Huang Jing-Jing , Jiang Yu-Ning , Liu Ya-Yang , Zhu Yao , Jiang Wei-Min
Published: December 2020

Heart failure (HF) has been known as a global health problem, and cardiac remodeling plays an essential role in the development of HF. We hypothesized that YQWY decoction might exert a cardioprotective effect against myocardium inflammation, fibrosis, and apoptosis via activating the interleukin‐10 (IL‐10)/Stat3 signaling pathway. To test this hypothesis, the HF model in rats was established by pressure overload through the minimally invasive transverse aortic constriction (MTAC). Echocardiography was performed to assess the left ventricular function of rats. Myocardial fibrosis in rats was observed by Masson and Picrosirius red staining, and the degree of myocardial apoptosis was detected via TUNEL staining. In addition, expression levels of IL‐10, tumor necrosis factor‐α (TNF‐α), Stat3 (P‐Stat3), P65 (P‐P65), CD68, collagen I, TGF‐β, CTGF, Bax, Bcl‐2, cleaved caspase‐3, and PARP in rat serum and myocardium samples were examined by ELISA, western blot, and immunohistochemistry, respectively. YQWY decoction treatment significantly improved left ventricular function in HF rats, especially in those of the high‐dose group (LVEF%: 51.29 ± 5.876 vs. 66.02 ± 1.264, P < 0.01;, LVFS%: 27.75 ± 3.757 vs. 37.76 ± 1.137, P < 0.01). Furthermore, YQWY decoction markedly inhibited MTAC‐induced myocardial fibrosis as evidenced by downregulated collagen I, TGF‐β, and CTGF in myocardium and alleviated apoptosis (downregulated caspase‐3 and PARP and increased Bcl‐2/Bax ratio in cardiomyocytes). In addition, YQWY decoction decreased the level of the proinflammatory cytokine TNF‐α in both circulating blood and myocardium and attenuated infiltration of inflammatory cells in heart tissue from HF rats. Most importantly, YQWY decoction suppressed MTAC‐induced NF‐κB activation and phosphorylated Stat3 by upregulating IL‐10 in rat heart tissues. Our study showed that YQWY decoction could attenuate MTAC‐induced myocardial inflammation, fibrosis, apoptosis, and reverse the impairment of cardiac function in rats by activating the IL‐10/Stat3 signaling pathway and improving myocardium remodeling. Our findings suggested a therapeutic potential of YQWY decoction in HF.
Preparation and Characterisation of Polypyrrole‐Iron Oxyhydroxide Nanocomposite as Sensing Material
Authors: Diauudin Farah Nabila , Mohd Noor Siti Aminah , Abdul Rashid Jahwarhar Izuan , Feizal Knight Victor , Wan Yunus Wan Md Zin , Ong Keat Khim , Mohd Kasim Noor Azilah , Taufik Safura , Samsuri Alinda , Shamsudin Intan Juliana , Latip Wahhida
Published: December 2020

Polypyrrole (PPy) has been widely used as a sensing material in many studies as PPy gives out noticeable reactions towards varieties of vapours of acids, bases, alcohols, alkanes, and chemical warfare agent (CWA) simulants. However, due to dispersion and mechanical properties limitation, PPy in nanoparticles (PPy NPs) has been introduced. The combinations between PPy NPs and nanosized metal oxide have shown promising improvement in the sensitivity of a sensor due to the larger total surface area of detection. In this study, the potential of PPy NPs and polypyrrole‐iron oxyhydroxide (PFFs) nanocomposite as sensing materials in detecting the CWA simulant, dimethyl methylphosphonate (DMMP), is investigated. PPy NPs and modified PFFs nanocomposite were successfully synthesised using chemical oxidative polymerisation. The formation of PPy NPs and the effect of iron‐oxyhydroxide (FeOOH) on the chemical interaction, morphology, and size of PPy NPs were investigated using attenuated total reflection‐Fourier transform infrared (ATR‐FTIR), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). ATR‐FTIR analysis showed that the modified PFFs nanocomposite was successfully produced through the presence of a sharp –OH peak. The size of the prepared PPy NPs and PFFs nanocomposite was observed in the range of 50 to 70 nm and 110 to 160 nm, respectively, through TEM analysis. The electrochemical behaviour of PPy NPs and PFFs nanocomposite towards DMMP was investigated using cyclic voltammetry (CV) where, in the presence of DMMP, PPy NPs and PFFs nanocomposite showed 24% and 21% current signal reduction, respectively. This suggests that both PPy NPs and PFFs nanocomposite are able to discriminate an electrical signal both with and without the presence of DMMP.