bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of tensile and compressive mechanical properties of typical aerospace alloy materials
Authors: Hu Yuting , Li Shuncai , Yu Qiu , Chen Ziyao , Vadim Slatin
Published: April 2021

For typical aerospace alloys, the mechanical properties of TC4 titanium alloy and 7075 aluminum alloy at different loading rates were investigated by uniaxial tension and compression experiments. The fracture microscopic morphologies of the two alloys were compared and analyzed using a scanning electron microscope. In addition, the experiment also combined infrared thermography technology (IRT) to compare and analyze the temperature variation characteristics of TC4 titanium alloy specimens under the same tensile and compressive loading rates. The research results show that the mechanical properties of TC4 titanium alloys are superior to those of 7075 aluminum alloys under the same tensile and compressive loading rates. Constitutive equations considering power-law hardening and tensile loading rate were derived to express the yield flow stress behavior.
Behaviours and attitudes in response to the COVID-19 pandemic: insights from a cross-national Facebook survey
Authors: Perrotta Daniela , Grow André , Rampazzo Francesco , Cimentada Jorge , Del Fava Emanuele , Gil-Clavel Sofia , Zagheni Emilio
Published: April 2021

Background

In the absence of medical treatment and vaccination, individual behaviours are key to curbing the spread of COVID-19. Here we describe efforts to collect attitudinal and behavioural data and disseminate insights to increase situational awareness and inform interventions.

Methods

We developed a rapid data collection and monitoring system based on a cross-national online survey, the “COVID-19 Health Behavior Survey”. Respondent recruitment occurred via targeted Facebook advertisements in Belgium, France, Germany, Italy, the Netherlands, Spain, the United Kingdom, and the United States. We investigated how the threat perceptions of COVID-19, the confidence in the preparedness of organisations to deal with the pandemic, and the adoption of preventive and social distancing behaviours are associated with respondents’ demographic characteristics.

Results

We analysed 71,612 questionnaires collected between March 13-April 19, 2020. We found substantial spatio-temporal heterogeneity across countries at different stages of the pandemic and with different control strategies in place. Respondents rapidly adopted the use of face masks when they were not yet mandatory. We observed a clear pattern in threat perceptions, sharply increasing from a personal level to national and global levels. Although personal threat perceptions were comparatively low, all respondents significantly increased hand hygiene. We found gender-specific patterns: women showed higher threat perceptions, lower confidence in the healthcare system, and were more likely to adopt preventive behaviours. Finally, we also found that older people perceived higher threat to themselves, while all respondents were strongly concerned about their family.

Conclusions

Rapid population surveys conducted via Facebook allow us to monitor behavioural changes, adoption of protective measures, and compliance with recommended practices. As the pandemic progresses and new waves of infections are a threatening reality, timely insights from behavioural and attitudinal data are crucial to guide the decision-making process.
Bifurcation and chaos of axially moving nanobeams considering two scale effects based on non-local strain gradient theory
Authors: Wang Jing , Shen Huoming , Zhang Bo , Sun Jianqiang , Zhang Yuanyuan
Published: April 2021

The nonlinear vibration of axially moving nanobeams at the microscale exhibits remarkable scale effects. A model of an axially moving nanobeam is established based on non-local strain gradient theory and considering two scale effects. The discrete equation of a non-autonomous planar system is obtained using the Galerkin method. The response characteristics of the system are determined using phase diagrams and Poincaré sections, and the effects of the scale parameters on the form of the motion are analyzed. The results show that as the non-local parameter and the material characteristic length parameter vary, the system undergoes multiple forms of motion, including periodic, period-doubling and chaotic motions. Two routes to chaos — period-doubling bifurcation and intermittent chaos — are identified in the variation ranges of the two scale parameters.
Indoor Constant Illumination Control Strategy Research Based on Natural Lighting Analysis
Authors: Ren Jing , Cao Xianghong , Li Jiaqi
Published: April 2021

Lighting energy consumption occupies a large proportion in the building electricity consumption. It cannot only save energy, but also reduce the uneven and constant illumination of the working face, which makes full use of the natural lighting and combines with the intelligent lighting control. An office building in Zhengzhou of China has been selected as an example for analyzing the climatic factors that influence building daylighting and the factors of the building itself, the illuminance of working faces in different sky models and at different times has been simulated and calculated to analyze the illuminance variation law in the direction of room depth and parallel direction of side Windows. Partition and point combined constant illumination control strategy for the lamps in different areas has been put forward and realized by BP neural network algorithm. By controlling the dimming of artificial light source and adjusting the curtain opening degree intelligently, uniform and constant illumination has been achieved. Energy saving effect in combination with natural lighting has been evaluated to prove that the control strategy cannot only maintain constant illumination in every working face but also significantly reduce the electric energy consumption and carbon dioxide emissions.
Thermal stability of Chaplygin gas models and Chevallier–Polarski–Linder parametrization
Authors: Saleem Muhammad , Jawad Abdul , Manzoor Rubab , Tufail Hafsa
Published: April 2021

We consider the fractal universe model with timelike fractal profile in flat Friedmann–Robertson–Walker (FRW) universe model and check the thermodynamic stability of various dark energy models. These dark energy models include family of Chaplygin gas models (such as generalized Chaplygin gas, modified Chaplygin gas, generalized cosmic Chaplygin gas, variable modified Chaplygin gas) and parametrized equation-of-state (Chevallier–Polarski–Linder) model. To check the stability of these models in fractal framework thermodynamically, we construct total equation-of-state parameter for each case. The conditions to check the stability of models depending on some thermodynamic quantities yield three conditions on this parameter. We graphically check the behavior of the equation-of-state parameter along with stability of each model. It is concluded that the dark energy models are thermodynamically stable under appropriate choices of model parameters.
Octupole correlations in 127I
Authors: Chakraborty S. , Sharma H. P. , Tiwary S. S. , Majumder C. , Gupta A. K. , Kumar A. , Banerjee P. , Ganguly S. , Kumar S. , Kumar A. , Singh R. P. , Muralithar S.
Published: April 2021

In-beam [Formula: see text]-ray spectroscopy of [Formula: see text]I was carried out following [Formula: see text]Sn(7Li, 4n[Formula: see text]) fusion-evaporation reaction at a beam energy of 33 MeV. Ratio of the electric dipole (E1) and electric quadrupole (E2) transition probabilities [B(E1)/B(E2)] for the transitions depopulating from the [Formula: see text] states have been extracted from this study. Existence of enhanced E1 transition rates between the opposite parity bands, associated dominantly with [Formula: see text] and [Formula: see text] configurations, provides an indication of octupole correlations in this nucleus
MATHEMATICAL ANALYSIS AND NUMERICAL SIMULATION OF A NONLINEAR DYNAMICAL MODEL FOR THE COEXISTENCE OF AGRICULTURE AND MINING IN RURAL AREAS
Authors: KUMARI MONIKA , TANDON ABHINAV
Published: April 2021

Agriculture and mining get interlinked with each other when they take place concurrently in rural parts of the world. In order to explore it in mathematical terms, a nonlinear dynamical model system is proposed in this study with agricultural yield, human population and mining as system variables. The agricultural yield is assumed to have logistic growth and also, supplements rural human population growth. Mining is assumed to be not only advancing with constant rate, but also getting induced through rural human population. The model is qualitatively analyzed for the identification of different equilibrium states and their stability behaviors. The model analysis reveals the conditions under which agriculture and mining together with rural population can achieve a stable system. These qualitative findings are substantiated with quantitative results, under which sensitiveness of different parameters of the model towards the model outcomes are investigated through global sensitivity analysis technique. Also, bifurcation parameters and their critical values are determined to predict the states of qualitative behavioral change. The results suggest that a balanced system can be obtained by taking measures to control unconducive mining and augment agricultural outputs.
DYNAMICS OF A PREDATOR–PREY MODEL WITH CROWLEY–MARTIN FUNCTIONAL RESPONSE, REFUGE ON PREDATOR AND HARVESTING OF SUPER-PREDATOR
Authors: PANJA PRABIR
Published: April 2021

In this paper, a three-species food chain model has been developed by considering the interaction between prey, predator and super-predator species. It is assumed that in the absence of predator and super-predator species, the prey species grow logistically. It is also assumed that predator and super-predator consume prey and predator, respectively. It is assumed that the predator shows refuge behavior to the super-predator. Again, harvesting of super-predator population has been considered. It is assumed that the consumption of prey and predator follows Crowley–Martin-type functional form. Boundedness of the solution of the system has been studied and different equilibrium points are determined and the stability of the system around these equilibrium points has been investigated. Existence conditions of Hopf bifurcation with respect to [Formula: see text] of the system have been studied. It is found that the system shows some complex and critical dynamics due to increase of handling time of prey. It is also found that the system moves towards stable steady state due to increase of predator interference. It is observed that predator refuge may be responsible for the stability of the system. The chaotic dynamics of the system have been found due to the increase of the harvesting rate of super-predator.
Exotic symplectomorphisms and contact circle actions
Authors: Drobnjak Dušan , Uljarević Igor
Published: April 2021

Using Floer-theoretic methods, we prove that the non-existence of an exotic symplectomorphism on the standard symplectic ball, [Formula: see text] implies a rather strict topological condition on the free contact circle actions on the standard contact sphere, [Formula: see text] We also prove an analogue for a Liouville domain and contact circle actions on its boundary. Applications include results concerning the symplectic mapping class group and the fundamental group of the group of contactomorphisms.
A note on classification of locally rotationally symmetric Bianchi type I space–times via conformal vector fields in f(T,B) gravity
Authors: Malik Shabeela , Hussain Fiaz , Shabbir Ghulam
Published: April 2021

The aim of this paper is to classify locally rotationally symmetric (LRS) Bianchi type I space-times via conformal vector fields (CVFs) in the [Formula: see text] gravity. In a first step, we find the space-times that are solutions of some [Formula: see text] gravity model. Furthermore, we classify the resulting space-times via CVFs. During the classification, there arise eight cases. Reviewing each case thoroughly, we find that in two cases, the space-times confess proper CVFs. The space-times in rest of the six cases either become conformally flat or tends to admit homothetic vector fields (HVFs) or the Killing vector fields (KVFs).
Detection of Chemotherapeutic Drug 6-Mercaptopurine Through Manipulating Localized Surface Plasmon Resonance Absorption of Silver Nanoplates
Authors: Cai Qingqing , Zhang Li , Li Ling , Tan Juan , Wu Shiyue , Wang Yi , Fu Wensheng
Published: April 2021

A new colorimetric method for the detection of chemotherapeutic drug 6-mercaptopurine (6-MP) is developed based on controlling localized surface plasmon resonance (LSPR) of triangular silver nanoplates (AgNPs). The triangular AgNPs can be etched by trace amount of Cl− and transformed to a disc-like shape, accompanied by a blueshift of the corresponding LSPR absorption band. With the protective effect of 6-MP, the AgNPs are hardly or partly to be etched by Cl−, resulting in a reversed shift of LSPR. Based on a linear relationship between LSPR wavelength change and the concentration of 6-MP, a fast, visual and selective method for 6-MP assay is established. This method has been successfully applied to the detection of 6-MP in tablets.
From the Editor: Hi-Fi to Wi-Fi and Beyond
Authors: Rajeshwar Krishnan
Published: April 2021

As another year draws to a close, I am caught in a reflective mood, pondering on all these years of steady, incremental progress interspersed with radical breakthroughs in technology. When I was a kid, radio provided the main connectivity to the outside world.
Centennial Campaign: Membership Objectives
Authors: Miller Troy M.
Published: April 2021

Members have been, and continue to be, the lifeblood of the Society. Therefore, making improvement in the overall member satisfaction is a significant goal of the ECS Centennial Campaign. The Electrochemical Society’s Case for Support includes three quantifiable objectives to better allow ECS to improve member satisfaction. These three objectives include increasing marketing efforts and improving customer service; increasing the availability of travel funding; and boosting student membership.
Nanowatch Europe: Chemical Modification of Carbon Nanotubes – From Single Molecule Chemistry to Single-Electron Transistors
Authors: Burghard Marko , Kern Klaus
Published: April 2021

Controlled chemical modification of carbon nanotubes is required for applications that are based on the specific interaction of nanotubes with other molecules. These applications include chemical sensors in the gas or liquid phase, mechanically reinforced composite materials, atomic force microscopy tips of tailored chemical sensitivity, as well as electrical contacting of biological systems like nerve cells.
Responding to a Harsh Business Environment: A New Diaphragm for the Chlor-Alkali Industry
Authors: Ahmed Sajjad , Foller Peter
Published: April 2021

The last several years have been difficult for producers of U.S. chlor-alkali chemicals. Low prices for chlorine and caustic and escalating fuel costs have resulted in several plant closures and have squeezed the profitability of those that have remained. For those plants operating with diaphragm cell technology, which still comprises a major portion of domestic production, conversion to membrane cells is not a viable option.
Optically Transparent Diamond Electrodes for UV-Vis and IR Spectroelectrochemistry
Authors: Stotter Jason , Haymond Shannon , Zak Jerzy , Show Yoshiyuki , Cvackova Zuzana , Swain Greg
Published: April 2021

No other material shows as much versatility as an electrode as does electrically conducting, chemical vapor deposited (CVD) diamond. The material can be used in electroanalysis to provide low detection limits for analytes with superb precision and stability; for high-current density electrolysis (1-10 A/cm2) in aggressive solution environments, without any microstructural or morphological degradation; as a corrosion-resistant electrocatalyst support; and as an optically transparent electrode (OTE) for spectroelectrochemical measurements.
Development of Phosphors for LEDS
Authors: Rohwer Lauren Shea , Srivastava Alok
Published: April 2021

Light emitting diodes are based on semiconductors, which emit spontaneous radiation under suitable forward bias conditions. The basic principle is based on low field injection electroluminescence where light is generated when injected minority carriers recombine with the majority carriers radiatively across the band gap of the crystal.
Detection of Glutathione Conjugate Export from Yeast Cells
Authors: Mauzeroll Janine
Published: April 2021

A Summary Report to The Electrochemical Society for the 2003 Edward G. Weston Summer Research Fellowship.
Anodic Stripping Voltammetry Enhancement by Redox Magnetohydrodynamics
Authors: Clark Emily A.
Published: April 2021

A Summary Report to The Electrochemical Society for the 2003 F. M. Becket Summer Research Fellowship.
Design, implementation, and assessment of an interactive simulation to teach undergraduate immunology students hemolytic disease of the newborn
Authors: Costabile Maurizio
Published: April 2021

Hemolytic disease of the newborn (HDN) is a potentially fatal condition caused by a Rhesus (Rh) antigen incompatibility between a mother and fetus. As a result, determining the Rh status of expectant parents is a routine clinical assessment. Both the physiological and immunological basis of this condition are taught to undergraduate students. At the University of South Australia, some undergraduate immunology students find this topic challenging. The author designed, implemented, and assessed the impact of an interactive simulation to facilitate student learning of HDN. The students were actively engaged in determining the blood grouping and Rh status of an expectant mother and father and then determining the possibility of developing HDN. The simulation was found to take only 15 min to complete yet led to a significant increase in student performance in an end of semester exam question. Student perceived understanding was found to significantly improve following the introduction of the simulation, even though the content had been covered in a formal lecture. Student feedback was highly positive of this learning approach. In conclusion, short, interactive simulations can be used effectively to enhance student learning of challenging concepts.
Treadmill Exercise during Pregnancy Decreased Vulnerability to Neonatal Hypoxia-Ischemia through Reducing Inflammation and Increasing Antiapoptotic Gene Expressions and Antioxidant Capacity in Rats
Authors: Gorgij Elahe , Fanaei Hamed , Yaghmaei Parichehr , Shahraki Mohammad Reza , Mirahmadi Hadi
Published: April 2021

Background. The purpose of present study was to assess the impact of maternal treadmill exercise during pregnancy on inflammation, oxidative stress, expression of Bax and Bcl-2 genes, and brain-derived neurotrophic factor (BDNF) level in neonatal rat brain after the hypoxia-ischemia injury. Material and Methods. A total of 24 female Wistar rats were utilized in this research. Two groups are randomly considered for rats: (1) not exercised through pregnancy and (2) exercised during pregnancy. Offsprings were divided into four groups including after delivery: (1) sham, (2) sham/exercise (sham/EX), (3) HI, and (4) HI+exercise. HI was induced in pups at postnatal day 8. Neurobehavioral tests were done seven days after HI induction. Then, the brain tissue was taken from the skull to estimate Bcl-2 and Bax gene expressions, BDNF, cerebral edema, infarct volume, inflammatory factors, oxidative stress, and neurological function. Results. The BDNF level in the HI+exercise group was considerably higher than the HI, sham, and sham/EX groups. Tumor necrosis factor (TNF-α), C-reactive protein (CRP), and the whole oxidant capacity (TOC) levels in the HI group were significantly higher than the sham and sham/EX groups. TNF-α, CRP, and TOC levels in the HI+exercise group were significantly lower than the HI group. Total antioxidant capacity (TAC) level in the HI+exercise group was significantly higher than the HI group. Infarct volume and edema percent in the HI+exercise group were significantly lower than the HI group. Neurological function in the HI+exercise group was significantly better than the HI group. Bax expression in the HI+exercise group was significantly lower than the HI group. Bcl-2 expression in the HI+exercise group was significantly higher than the HI group. In the sham group, BDNF, TNF-α, CRP, TAC, TOC, edema levels, and neurological function had no significant difference with the sham/EX group. Conclusion. It appears that the maternal treadmill exercise during pregnancy exerts a supportive impact against neonatal HI brain injury through increasing antioxidant capacity, Bcl-2 expression, and BDNF levels and decreasing inflammation that is resulted in the lower infarct volume and sensorimotor dysfunction.
On the Irreducibility of Polynomials Associated with the Complete Residue Systems in any Imaginary Quadratic Fields
Authors: Phetnun Phitthayathon , Kanasri Narakorn Rompurk , Singthongla Patiwat
Published: April 2021

For a Gaussian prime

π

and a nonzero Gaussian integer

β
=
a
+
b
i
∈
ℤ

i

with

a
≥
1

and

β

≥
2
+

2

, it was proved that if

π
=

α

n

β

n

+

α

n
−
1

β

n
−
1

+
⋯
+

α

1

β
+

α

0

≕
f

β

where

n
≥
1

,

α

n

∈
ℤ

i

\

0

,

α

0

,
…
,

α

n
−
1

belong to a complete residue system modulo

β

, and the digits

α

n
−
1

and

α

n

satisfy certain restrictions, then the polynomial

f

x

is irreducible in

ℤ

i

x

. For any quadratic field

K
≔
ℚ

m

, it is well known that there are explicit representations for a complete residue system in

K

, but those of the case

m
≡
1
 

mod
4

are inapplicable to this work. In this article, we establish a new complete residue system for such a case and then generalize the result mentioned above for the ring of integers of any imaginary quadratic field.
Understanding the Integrated Pathways and Mechanisms of Transporters, Protein Kinases, and Transcription Factors in Plants under Salt Stress
Authors: Shah Wasifa Hafiz , Rasool Aadil , Saleem Seerat , Mushtaq Naveed Ul , Tahir Inayatullah , Hakeem Khalid Rehman , Rehman Reiaz Ul
Published: April 2021

Abiotic stress is the major threat confronted by modern-day agriculture. Salinity is one of the major abiotic stresses that influence geographical distribution, survival, and productivity of various crops across the globe. Plants perceive salt stress cues and communicate specific signals, which lead to the initiation of defence response against it. Stress signalling involves the transporters, which are critical for water transport and ion homeostasis. Various cytoplasmic components like calcium and kinases are critical for any type of signalling within the cell which elicits molecular responses. Stress signalling instils regulatory proteins and transcription factors (TFs), which induce stress-responsive genes. In this review, we discuss the role of ion transporters, protein kinases, and TFs in plants to overcome the salt stress. Understanding stress responses by components collectively will enhance our ability in understanding the underlying mechanism, which could be utilized for crop improvement strategies for achieving food security.
The Effect of Two Types of Exercise Preconditioning on the Expression of TrkB, TNF‐α, and MMP2 Genes in Rats with Stroke
Authors: Teymuri Kheravi Mostafa , Nayebifar Shila , Aletaha Seyedeh Motahareh , Sarhadi Sara
Published: April 2021

Despite the beneficial effects of exercise and physical activity, there is little knowledge about the effects of different types of physical activity on neural function. The present study assessed the effects of two types of selected aerobic exercises prior to stroke induction and characterized the expression of TrkB, TNF‐α, and MMP2 genes in vivo. Forty male adult Wistar rats were exposed to aerobic exercises following randomization into four groups, including swimming + MCAO (Middle Cerebral Artery Occlusion) (n = 10), treadmill training + MCAO (n = 10), MCAO (n = 10), and control (n = 10). The swimming + MCAO group included swimming for 30 minutes each day, while the treadmill training + MCAO group program involved running for 30 minutes each day at an intensity of 15 m/min, for three weeks, five days a week. Neurological deficit was assessed using modified criteria at 24 h after the onset of cerebral ischemia. In the control group, the animals worked freely for three weeks without undergoing ischemia. The MCAO group also operated freely for three weeks after they underwent a stroke. Both training groups underwent ischemia after three weeks of training. TrkB, TNF‐α, and MMP2 gene expressions were increased in the MCAO+ swimming training and in the MCAO + running training group compared to the control and MCAO groups, respectively. Preconditioning aerobic exercises significantly increased brain trophic support and reduced brain damage conditions in exercise groups, which support the importance of aerobic exercise in the prevention and treatment of stroke.
Quantitative Analysis of Postural Instability in Patients with Parkinson’s Disease
Authors: Yu Yang , Liang Siquan , Wang Yue , Zhao Yanan , Zhao Jiaojiao , Li Haitao , Wu Jingchao , Cheng Yuanyuan , Wu Fan , Wu Jialing
Published: April 2021

Introduction. Postural instability is commonly observed in Parkinson’s disease, leading to an increasing risk of falling and worsening as the disease progresses. We found that limit of stability can be applied to reflect the dynamic evolution of postural instability in patients with Parkinson's disease. Methods. Forty-three patients (9 of Hoehn and Yahr stage I, 12 of stage II, 14 of stage III, and 8 of stage IV) met the criteria for the diagnosis of idiopathic Parkinson’s disease and could stand independently for at least 10 minutes. Twelve healthy controls with no sign of parkinsonism were also recruited. Postural instability was assessed by posturography in different directions (forward, backward, right, left, forward-right, forward-left, backward-right, and backward-left). This study trial was registered with the Chinese Clinical Trial Registry (no. ChiCTR1900022715). Results. All participants were able to complete the limit of stability tasks without any complications. Patients in stages II to IV exhibited smaller end point excursion and slower time to complete than controls, suggesting an impaired limit of stability. The patients in stage II exhibited a remarkable decline in most directions compared to controls, except for right and left, and forward and backward decline occurred the earliest. For patients in stage III, right was the only direction with no significant difference from controls. In stage IV patients, the limit of stability declined significantly in all directions (

p
<
0.05

). Conclusions. The postural abnormalities of Parkinson’s disease can occur at early stages, and the pattern of decline is more severe in the forward-backward direction. This trial is registered with ChiCTR1900022715.
Exploring Local People’s Perception of Ecosystem Services in Djoumouna Periurban Forest, Brazzaville, Congo
Authors: Kimpouni V. , Nzila J. D. D. , Watha-Ndoudy N. , Madzella-Mbiemo M. I. , Yallo Mouhamed S. , Kampe J.-P.
Published: April 2021

The perception of ecosystem goods and services by local residents is studied in Brazzaville, around the periurban forest of Djoumouna. This study, which documents the ecosystem services provided to communities by this ecosystem facing anthropogenic degradation, evaluates the understanding and consideration of these functions, according to socioprofessional categories. Socioeconomic and ethnobotanical surveys conducted among the group of informants are supported by direct field observations and literature review. The data collected within a 2 km radius around the forest were subjected to descriptive and statistical analysis. The group of informants, including all socioprofessional strata, was organised into 4 age groups and involved 143 heads of household aged from 15 to over 45. The survey reveals 14 ecosystem services that fall into three categories. The provisioning services included food, wood energy, pharmacopoeia, and wood services. The regulatory functions cited are maintaining air quality, shade, erosion control, and windbreak. Recognized sociocultural services are the source of income, recreation, and ecotourism, source of inspiration, fishing, initiation sanctuary, and hunting. According to gender, men are more dependent on the forest than women, and those aged 15–25 and over 45 are the most active. The socioprofessional scale shows an unequal exploitation of the forest. The informants, at least for the majority, integrate the notions of the value of ecosystem services, provided by the Djoumouna periurban forest, into their daily lives. Finally, the study highlights the social and ecological value of periurban and urban forests in the daily lives of people and urban resilience.
Evaluation of Potential Correlation of Piano Teaching Using Edge-Enabled Data and Machine Learning
Authors: Sun Sibing
Published: April 2021

Data science has expanded at an exponential growth with the advancement of big data technology. The data analysis techniques need to delve deeper to find valuable information (Sarac 2017). The notion of edge computing is broadly acknowledged. Edge-enabled solutions provide computing, analysis, storage, and control nearer to the edge of the network, which support the efficient processing and decision-making. Machine learning has also attained significant attention in this context due to its flexibility and its ability to provide a variety of supervised, unsupervised, and semisupervised techniques. This research presents a specific model to evaluate the potential correlation of piano teaching using machine learning. The data analysis is performed at the edges of network for efficient results (Tan et al. 2017). The association rule mining technique of machine learning is utilized with the integration of improved T-test method. The improved T-test is performed for the measurement of association rules and proposed a new measure and influence degree of association rules. It is evident from the results that the use of the degree of influence as a measure of association rules to find the potential relevance of multimedia-assistant piano teaching evaluation data is extremely feasible. It overcomes shortcomings of existing measurement standards and reduces the generation of redundant rules. The existing literature highlights the concepts of evaluation of potential correlation and evaluates the advantages. However, there is a lack of an effective strategy for piano teaching. The proposed model performs efficient calculation and storage. The feasibility and effectiveness of the proposed framework are verified using the analysis of the actual dataset. The verification results show that it is feasible and valuable to find the potential relevance of multimedia-assisted piano teaching evaluation.
Fast Mumford-Shah Two-Phase Image Segmentation Using Proximal Splitting Scheme
Authors: Shah Nilima , Patel Dhanesh , Fränti Pasi
Published: April 2021

The Mumford-Shah model is extensively used in image segmentation. Its energy functional causes the content of the segments to remain homogeneous and the segment boundaries to become short. However, the problem is that optimization of the functional can be very slow. To attack this problem, we propose a reduced two-phase Mumford-Shah model to segment images having one prominent object. First, initial segmentation is obtained by the k-means clustering technique, further minimizing the Mumford-Shah functional by the Douglas-Rachford algorithm. Evaluation of segmentations with various error metrics shows that 70 percent of the segmentations keep the error values below 50%. Compared to the level set method to solve the Chan-Vese model, our algorithm is significantly faster. At the same time, it gives almost the same or better segmentation results. When compared to the recent k-means variant, it also gives much better segmentation with convex boundaries. The proposed algorithm balances well between time and quality of the segmentation. A crucial step in the design of machine vision systems is the extraction of discriminant features from the images, which is based on low-level segmentation which can be obtained by our approach.
LIFU Alleviates Neuropathic Pain by Improving the KCC2 Expression and Inhibiting the CaMKIV–KCC2 Pathway in the L4–L5 Section of the Spinal Cord
Authors: Liao Ye-Hui , Wang Bin , Chen Mo-Xian , Liu Yao , Ao Li-Juan
Published: April 2021

Effective treatment remains lacking for neuropathic pain (NP), a type of intractable pain. Low-intensity focused ultrasound (LIFU), a noninvasive, cutting-edge neuromodulation technique, can effectively enhance inhibition of the central nervous system (CNS) and reduce neuronal excitability. We investigated the effect of LIFU on NP and on the expression of potassium chloride cotransporter 2 (KCC2) in the spinal cords of rats with peripheral nerve injury (PNI) in the lumbar 4–lumbar 5 (L4–L5) section. In this study, rats received PNI surgery on their right lower legs followed by LIFU stimulation of the L4–L5 section of the spinal cord for 4 weeks, starting 3 days after surgery. We used the 50% paw withdraw threshold (PWT50) to evaluate mechanical allodynia. Western blotting (WB) and immunofluorescence (IF) were used to calculate the expression of phosphorylated extracellular signal–regulated kinase 1/2 (p-ERK1/2), calcium/calmodulin-dependent protein kinase type IV (CaMKIV), phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB), and KCC2 in the L4–L5 portion of the spinal cord after the last behavioral tests. We found that PWT50 decreased (

P
<
0.05

) 3 days post-PNI surgery in the LIFU− and LIFU+ groups and increased (

P
<
0.05

) after 4 weeks of LIFU stimulation. The expression of p-CREB and CaMKIV decreased (

P
<
0.05

) and that of KCC2 increased (

P
<
0.05

) after 4 weeks of LIFU stimulation, but that of p-ERK1/2 (

P
>
0.05

) was unaffected. Our study showed that LIFU could effectively alleviate NP behavior in rats with PNI by increasing the expression of KCC2 on spinal dorsal corner neurons. A possible explanation is that LIFU could inhibit the activation of the CaMKIV–KCC2 pathway.
A Systematic Review and Meta-Analysis of Risk Factors Associated with Severity and Death in COVID-19 Patients
Authors: Du Pengqiang , Li Dandan , Wang Aifeng , Shen Su , Ma Zhichao , Li Xingang
Published: April 2021

This meta-analysis aims to screen the risk factors for severe illness and death and provide help for early clinical treatment of the new coronavirus (COVID-19). Based on a comprehensive search of PubMed, Embase, and Web of Science databases, we included studies that explored the cause and risk factors for severe illness and death in COVID-19 patients. We evaluated the strength of this relationship using odds ratios (ORs) with 95% confidence intervals (CIs). A total of 17 articles were included; 16 of the 17 articles were from China, and the risk factors associated with severe illness and death were age, sex, and multiple comorbidities. Advanced age (≥65 years, severe illness, OR = 2.62; death, OR = 6.00), male (severe illness, OR = 1.49; death, OR = 1.54), chronic respiratory diseases (severe illness, OR = 5.67; death, OR = 3.72), diabetes (severe illness, OR = 3.27; death, OR = 2.60), hypertension (severe illness, OR = 3.08; death, OR = 3.53), chronic kidney disease (severe illness, OR = 3.59; death, OR = 5.38), and cardiovascular diseases (severe illness, OR = 3.87; death, OR = 4.91) were all risk factors. For COVID-19 patients, advanced age, male, and patients with chronic disease are at higher risk of developing severe illness or even death.
[Retracted] Epicardial Adipose Tissue Volume Is Associated with High Risk Plaque Profiles in Suspect CAD Patients
Authors: Shan Dongkai , Dou Guanhua , Yang Junjie , Wang Xi , Wang Jingjing , Zhang Wei , He Bai , Liu Yuqi , Chen Yundai , Li Yang
Published: April 2021

Objective. To explore the association between EAT volume and plaque precise composition and high risk plaque detected by coronary computed tomography angiography (CCTA). Methods. 101 patients with suspected coronary artery disease (CAD) underwent CCTA examination from March to July 2019 were enrolled, including 70 cases acute coronary syndrome (ACS) and 31 cases stable angina pectoris (SAP). Based on CCTA image, atherosclerotic plaque precise compositions were analyzed using dedicated quantitative software. High risk plaque was defined as plaque with more than 2 high risk features (spotty calcium, positive remolding, low attenuation plaque, napkin‐ring sign) on CCTA image. The association between EAT volume and plaque composition was assessed as well as the different of correlation between ACS and SAP was analyzed. Multivariable logistic regression analysis was used to explore whether EAT volume was independent risk factors of high risk plaque (HRP). Results. EAT volume in the ACS group was significantly higher than that of the SAP group (143.7 ± 49.8 cm3 vs. 123.3 ± 39.2 cm3, P = 0.046). EAT volume demonstrated a significant positive correlation with total plaque burden (r = 0.298, P = 0.003), noncalcified plaque burden (r = 0.245, P = 0.013), lipid plaque burden (r = 0.250, P = 0.012), and homocysteine (r = 0.413, P ≤ 0.001). In ACS, EAT volume was positively correlated with total plaque burden (r = 0.309, P = 0.009), noncalcified plaque burden (r = 0.242, P = 0.044), and lipid plaque burden (r = 0.240, P = 0.045); however, no correlation was observed in SAP. Patients with HRP have larger EAT volume than those without HRP (169 ± 6.2 cm3 vs. 130.6 ± 5.3 cm3, P = 0.002). After adjustment by traditional risk factors and coronary artery calcium score (CACS), EAT volume was an independent risk predictor of presence of HRP (OR: 1.018 (95% CI: 1.006‐1.030), P = 0.004). Conclusions. With the increasing EAT volume, more dangerous plaque composition burdens increase significantly. EAT volume is a risk predictor of HRP independent of convention cardiovascular risk factors and CACS, which supports the potential impact of EAT on progression of coronary atherosclerotic plaque.
Time‐Frequency Analysis and Target Recognition of HRRP Based on CN‐LSGAN, STFT, and CNN
Authors: Nie Jianghua , Xiao Yongsheng , Huang Lizhen , Lv Feng
Published: April 2021

Aiming at the problem of radar target recognition of High‐Resolution Range Profile (HRRP) under low signal‐to‐noise ratio conditions, a recognition method based on the Constrained Naive Least‐Squares Generative Adversarial Network (CN‐LSGAN), Short‐time Fourier Transform (STFT), and Convolutional Neural Network (CNN) is proposed. Combining the Least‐Squares Generative Adversarial Network (LSGAN) with the Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN‐GP), the CN‐LSGAN is presented and applied to the HRRP denoise. The frequency domain and phase features of HRRP are gained by STFT in order to facilitate feature learning and also match the input data format of the CNN. These experimental results show that the CN‐LSGAN has better data augmentation performance and can effectively avoid the model collapse compared to the generative adversarial network (GAN) and LSGAN. Also, the method has better recognition performance than the one‐dimensional CNN method and the Long Short‐Term Memory (LSTM) network method.
Magnetohydrodynamic Time-Dependent Bio-Nanofluid Flow in a Porous Medium with Variable Thermophysical Properties
Authors: Irfan M. , Farooq M. Asif , Aslam A. , Mushtaq A. , Shamsi Z. H.
Published: April 2021

In this work, a theoretical model with a numerical solution is brought forward for a bio-nanofluid with varying fluid features over a slippery sheet. The partial differential equations (PDEs) involving temperature-dependent quantities have been translated into ordinary differential equations (ODEs) by using similarity variables. Numerical verifications have been done in three different methods: finite difference method, shooting method, and bvp4c. To figure out the influence of parameters on the flows, the graphs are plotted for the velocity, temperature, concentration, and microorganism curves. The boundary layer thickness of the microorganism profile reduces with the Schmidt number and Peclet number. In addition to adding radiative heat flux, we added heat generation, rate of chemical reaction, and first-order slip. Adding these parameters brought new aspects to the underlying profiles. Moreover, the obtained data of the skin friction coefficient, the local Nusselt number, the local Sherwood number, and the local density of motile microorganisms are tabulated against various parameters for the physical parameters. From the results, it is apparent that the local Nusselt number decreases with the Brownian and thermophoretic parameters. The data obtained for physical parameters have a close agreement with the published data. Finally, the graphs for slip conditions are significantly different when the comparison is drawn with no-slip condition.
Identification of Molecular Regulatory Features and Markers for Acute Type A Aortic Dissection
Authors: Lian Rui , Zhang Guochao , Yan Shengtao , Sun Lichao , Zhang Guoqiang
Published: April 2021

Background. Acute type A aortic dissection (ATAAD) is one of the most lethal cardiovascular diseases, and its molecular mechanism remains unclear. Methods. Differentially expressed genes (DEGs) between ATAAD and control were detected by limma R package in GSE52093, GSE153434, GSE98770, and GSE84827, respectively. The coexpression network of DEGs was identified by the WGCNA package. Enrichment analysis was performed for module genes that were positively correlated with ATAAD using clusterProfiler R package. In addition, differentially methylated markers between aortic dissection and control were identified by ChAMP package. After comparing with ATAAD-related genes, a protein-protein interaction (PPI) network was established based on the STRING database. The genes with the highest connectivity were identified as hub genes. Finally, differential immune cell infiltration between ATAAD and control was identified by ssGSEA. Results. From GSE52093 and GSE153434, 268 module genes were obtained with consistent direction of differential expression and high correlation with ATAAD. They were significantly enriched in T cell activation, HIF-1 signaling pathway, and cell cycle. In addition, 2060 differentially methylated markers were obtained from GSE84827. Among them, 77 methylation markers were ATAAD-related DEGs. Using the PPI network, we identified MYC, ITGA2, RND3, BCL2, and PHLPP2 as hub genes. Finally, we identified significantly differentially infiltrated immune cells in ATAAD. Conclusion. The hub genes we identified may be regulated by methylation and participate in the development of ATAAD through immune inflammation and oxidative stress response. The findings may provide new insights into the molecular mechanisms and therapeutic targets for ATAAD.
Differential ROS‐Mediated Phosphorylation of Drp1 in Mitochondrial Fragmentation Induced by Distinct Cell Death Conditions in Cerebellar Granule Neurons
Authors: Cid-Castro Carolina , Morán Julio
Published: April 2021

Reactive oxygen species (ROS) production has been associated with neuronal death. ROS are also involved in mitochondrial fission, which is mediated by Dynamin‐related protein 1 (Drp1). The regulation of mitochondrial fragmentation mediated by Drp1 and its relationship to mitochondrial ROS (mtROS) in neuronal death have not been completely clarified. The aim of this study is to evaluate the role of mtROS in cell death and their involvement in the activation of Drp1 and mitochondrial fission in a model of cell death of cultured cerebellar granule neurons (CGN). Neuronal death of CGN induced by potassium deprivation (K5) and staurosporine (ST) triggers mitochondrial ROS production and mitochondrial fragmentation. K5 condition evoked an increase of Drp1 phosphorylation at Ser616, but ST treatment led to a decrease of Drp1 phosphorylation. Moreover, the death of CGN induced by both K5 and ST was markedly reduced in the presence of MitoTEMPO; however, mitochondrial morphology was not recovered. Here, we show that the mitochondria are the initial source of ROS involved in the neuronal death of CGN and that mitochondrial fragmentation is a common event in cell death; however, this process is not mediated by Drp1 phosphorylation at Ser616.
Linear Barycentric Rational Method for Two-Point Boundary Value Equations
Authors: Ge Qian , Zhang Xiaoping
Published: April 2021

Linear barycentric rational method for solving two-point boundary value equations is presented. The matrix form of the collocation method is also obtained. With the help of the convergence rate of the interpolation, the convergence rate of linear barycentric rational collocation method for solving two-point boundary value problems is proved. Several numerical examples are provided to validate the theoretical analysis.
Percutaneous Nephrolithotomy Can Reduce the Incidence of Sepsis Compared with Flexible Ureteroscopy in Treating Solitary Proximal Ureteral Stone Patients with Positive Urine Culture
Authors: Xia Qi-Dong , Wang Yu-Feng , Liu Chen-Qian , Xu Jin-Zhou , Sun Jian-Xuan , Xun Yang , Li Cong , Hu Jia , Lu Jun-Lin , Wang Shao-Gang
Published: April 2021

Background. Sepsis is a potentially lethal complication for both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL). This study is aimed at comparing the sepsis rate after fURS and PCNL and the risk factors for sepsis in patients with solitary proximal ureteral stone. Methods. We reviewed the data of patients with calculi between 10 mm to 20 mm who underwent fURS or PCNL surgery from Tongji Hospital’s database. A total of 910 patients were eligible with 412 fURS cases and 498 PCNL cases. We used univariate analysis and multivariate logistic regression analysis to identify the risk factors for sepsis. Subgroup analysis was performed using logistic regression analysis. Results. In the cohort, 27 (6.6%) and 19 (3.8%) patients developed sepsis after fURS and PCNL, respectively. Multivariate analysis shows that the risk factors for sepsis are fURS (OR = 3.160, P = 0.004), serum WBC ≥ 10,000 cells/μL (OR = 3.490, P = 0.008), albumin − globulin ratio < 1.2 (OR = 2.192, P = 0.029), positive urine culture (OR = 6.145, P < 0.001), and prolonged operation time (OR = 1.010, P = 0.046). Subgroup analysis was conducted using potential risk factors: stone size, serum WBC, urine culture, and albumin‐globulin ratio (AGR). In subgroup of positive urine culture, patients were more likely to develop sepsis after fURS than PCNL. Conclusions. PCNL may be a better choice than fURS to reduce postoperative sepsis, especially for patients with positive urine culture.