bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of coaxial and waveguide couplers for helix TWT
Authors: Alaria Mukesh Kumar , Ghosh Sanjay Kumar 
Published: February 2021

Abstract
In this paper, two types of coaxial coupler and waveguide coupler for different frequency helix traveling wave tubes (TWTs) are designed, fabricated and cold tested. The coaxial coupler includes of window ceramic and RF transformer section. At present multi-section impedance transformer design approach is used for wideband helix TWTs. In any helix TWT, impedance of the source is transformed to the characteristic impedance of helix. This is done by the quarter-wavelength (λ/4) impedance transformation approach. The simulated results of different types of couplers are carried out by HFSS and CST microwave studio software and compare with experimental results. Three-dimensional electromagnetic field simulators allowing the any geometry with port excitations it is possible to model the complex coaxial and waveguide type couplers with helix SWS assembly and predict its desired return loss performances.
Comparison of the effects of zinc oxide and zinc oxide nanoparticles on the expression of hepcidin gene in rat liver
Authors: Pourmohammad Pirouz , Alipanah-Moghadam Reza , Nemati Ali , Malekzadeh Vadoud , Mahmoodzadeh Yavar 
Published: February 2021

Abstract

Objectives
Nanoparticles have special properties, such as increased intestinal absorption, permeability, and so on. Zinc oxide (ZnO) nanoparticles have medical applications such as using in drug production. Studies of ZnO nanoparticles have shown the role of these particles in reducing or increasing the genes expression. Given the important role of hepcidin in the development of anemia and iron overload diseases, this study investigated the effect of ZnO nanoparticles on the hepatic expression of the hepcidin gene to help find a way to treat these diseases.

Methods
In this experimental study, 24 male Westar rats were divided into three groups: control, ZnO treating group and ZnO nanoparticle treating group. Both ZnO and ZnO nanoparticles were injected with 50 mg/kg body weight for 14 days. At the end, serums were collected and iron, ferritin and IL-6 levels were measured. Expression of the hepcidin gene was done by Real Time PCR.

Results
ZnO and the ZnO nanoparticle significantly increased the expression of the hepcidin gene relative to the control group. The increase in expression of the hepcidin gene in ZnO nanoparticles was more significant than in the ZnO.

Conclusion
ZnO nanoparticles led to significant increase in expression of the hepcidin gene.
COVID-19 and cardiovascular disease: a review of current knowledge
Authors: Pal Aastha , Ahirwar Ashok Kumar , Sakarde Apurva , Asia Priyanka , Gopal Niranjan , Alam Sana , Kaim Kirti , Ahirwar Pradeep , Sorte Smita R. 
Published: February 2021

Abstract
The uncontrolled spread of the COVID-19 pandemic which originated in China created a global turmoil. While the world is still busy figuring out a cure for the deadly disease, scientists worked out on many theories and conducted several studies to establish a relationship between the infection and other known diseases. Cardiovascular diseases (CVD) are one of the major complications of this infection after the respiratory manifestations. Individuals with cardiovascular complication are said to be more susceptible to acquiring the infection because the novel coronavirus uses the ACE2 receptor for its entry inside the cell and there is a high level of ACE2 expression in individuals with cardiovascular complications because of the enzyme’s anti-hypertrophic, anti-fibrotic and anti-hypertensive effects on the heart. Individuals who belong to the older age group are also more susceptible. Knowing the above information, it might seem that using ACE2 inhibitors would help to slow or prevent the entry of the novel coronavirus but it would also at the same time prove to have deleterious effects on the cardiovascular system as the protective functions of ACE2 would be lost. While the search for a cure still continues it has been stated many a times that the conditions might worsen with time and the only way to keep ourselves and our family safe would be to follow the appropriate social distancing methods and get a COVID test if we experience any of the major symptoms.
COVID-19 and nutritional deficiency: a review of existing knowledge
Authors: Muthuvattur Pallath Meghana , Ahirwar Ashok Kumar , Chandra Tripathi Satyendra , Asia Priyanka , Sakarde Apurva , Gopal Niranjan 
Published: February 2021

Abstract
COVID-19 has resulted in an ongoing global pandemic, which spread largely among people who have had close contact with the infected person. The immunopathology of the SARS-CoV-2 virus includes the production of an excess amount of pro-inflammatory cytokines “a cytokine-storm”. The respiratory system (main), cardiovascular system and the gastrointestinal tract are the most affected body systems during viral infection. It has been found that most of the patients who require admission to hospital are elderly or have chronic underlying diseases. Higher cases of malnutrition and co-morbidities like diabetes mellitus and cardiovascular diseases are reported in elderly patients due to which, the immune system weakens and hence, the response to the virus is diminished in magnitude. A deficiency of micronutrients results in impaired immune responses leading to improper secretion of cytokines, alterations in secretory antibody response and antibody affinity which increases susceptibility to viral infection. The deficiency of various micronutrients in COVID-19 patient can be treated by appropriate nutritional supplements, prescribed after evaluating the patients’ nutritional status. Here we aim to highlight the role of a few particular nutrients namely Vitamin D, Vitamin C, Omega-3 fatty acids, Zinc and Magnesium along with the synergistic roles they play in enhancing immunity and thus, maintaining homeostasis.
Berberine improves dietary-induced cardiac remodeling by upregulating Kruppel-like factor 4-dependent mitochondrial function
Authors: Ding Laili , Li Shufeng , Wang Fan , Xu Jian , Li Shaojun , Wang Bo , Kou Junjie , Wang Yongshun , Cao Wei 
Published: February 2021

Abstract
Multiple studies have showed that berberine protects against heart diseases, including obesity-associated cardiomyopathy. However, it is not fully disclosed the potential molecular mechanisms of berberine on controlling cardiac remodeling. Kruppel-like factor (KLF) 4, identified as a critical transcriptional factor, participates in multiple cardiac injuries. The present study was to explore whether KLF4 determined the cardioprotective benefits of berberine in dietary-induced obese mice. High fat diet-induced obese mice were treated with berberine with or without lentivirus encoding Klf4 siRNA, and cardiac parameters were analyzed by multiple biological approaches. In dietary-induced obese mouse model, administration of berberine obviously increased cardiac level of KLF4, which closely correlated with improvement of cardiac functional parameters. Co-treatment of lentivirus encoding Klf4 siRNA abolished cardioprotective benefits of berberine, including induction of cardiac hypertrophy, fibrosis, functional disorders, inflammatory response and oxidative stress. Mechanistically, we found berberine improved cardiac mitochondrial biogenesis and activities, whereas silencing Klf4 decreased berberine-upregulated mitochondrial quality, ATP production and oxygen consumption. Our present study demonstrated that berberine protected against dietary-induced cardiac structural disorders and mitochondrial dysfunction dependent on cardiac KLF4 signaling. Cardiac KLF4 was one of potential therapeutic targets for obesity-induced cardiac injuries.
Direct comparison of the immunogenicity of major histocompatibility complex-I and -II deficient mesenchymal stem cells in vivo
Authors: Halm Darius , Leibig Nico , Martens Jens , Stark G. Björn , Groß Tobias , Zimmermann Stefan , Finkenzeller Günter , Lampert Florian 
Published: February 2021

Abstract
Mesenchymal stem cells (MSCs) play an important role in tissue engineering applications aiming at the regeneration or substitution of damaged tissues. In this context, off-the-shelf allogeneic MSCs would represent an attractive universal cell source. However, immune rejection is a major limitation for the clinical use of allogeneic MSCs. Immune rejection is mediated by the expression of major histocompatibility complexes (MHC)-I and -II on the donor cells. In this study, we eliminated MHC-I and/or MHC-II expression in human MSCs by using the CRISPR/Cas9 technology and investigated the effect of the individual or combined knockout of MHC-I and MHC-II on MSC survival after transplantation into immunocompetent mice. Elimination of MHC-I and/or MHC-II expression did not affect mesenchymal marker gene expression, viability, proliferation and the differentiation potential of MSCs in vitro. However, cell survival of transplanted MSCs was significantly elevated in MHC-I and MHC-II deficient MSCs. A direct side-by-side comparison does not reveal any significant difference in the immunogenicity of MHC-I and MHC-II knockout MSCs. Moreover, double knockout of MHC-I and MHC-II did not further increase in vivo cell survival of transplanted MSCs. Our results demonstrate that knockout of MHC-I and/or MHC-II represents an effective strategy to prevent immune rejection of allogeneic MSCs.
Human RecQ helicases in transcription-associated stress management: bridging the gap between DNA and RNA metabolism
Authors: Das Tulika , Pal Surasree , Ganguly Agneyo 
Published: February 2021

Abstract
RecQ helicases are a highly conserved class of DNA helicases that play crucial role in almost all DNA metabolic processes including replication, repair and recombination. They are able to unwind a wide variety of complex intermediate DNA structures that may result from cellular DNA transactions and hence assist in maintaining genome integrity. Interestingly, a huge number of recent reports suggest that many of the RecQ family helicases are directly or indirectly involved in regulating transcription and gene expression. On one hand, they can remove complex structures like R-loops, G-quadruplexes or RNA:DNA hybrids formed at the intersection of transcription and replication. On the other hand, emerging evidence suggests that they can also regulate transcription by directly interacting with RNA polymerase or recruiting other protein factors that may regulate transcription. This review summarizes the up to date knowledge on the involvement of three human RecQ family proteins BLM, WRN and RECQL5 in transcription regulation and management of transcription associated stress.
Seemingly unrelated regression with measurement error: estimation via Markov Chain Monte Carlo and mean field variational Bayes approximation
Authors: Bresson Georges , Chaturvedi Anoop , Rahman Mohammad Arshad , Shalabh  
Published: February 2021

Abstract
Linear regression with measurement error in the covariates is a heavily studied topic, however, the statistics/econometrics literature is almost silent to estimating a multi-equation model with measurement error. This paper considers a seemingly unrelated regression model with measurement error in the covariates and introduces two novel estimation methods: a pure Bayesian algorithm (based on Markov chain Monte Carlo techniques) and its mean field variational Bayes (MFVB) approximation. The MFVB method has the added advantage of being computationally fast and can handle big data. An issue pertinent to measurement error models is parameter identification, and this is resolved by employing a prior distribution on the measurement error variance. The methods are shown to perform well in multiple simulation studies, where we analyze the impact on posterior estimates for different values of reliability ratio or variance of the true unobserved quantity used in the data generating process. The paper further implements the proposed algorithms in an application drawn from the health literature and shows that modeling measurement error in the data can improve model fitting.
Minimum time controller in a class of chemical reactors based on Lagrangian approach
Authors: Aguilar-López Ricardo , Mata-Machuca Juan L. 
Published: February 2021

Abstract
The main goal of this work is the construction of a class of controller, which employs directly a Lagrangian formulation to resolve the classical brachistochrone problem, this allows to obtain an optimal controller which reaches in a minimum time the stabilization of an isothermal continuous stirred tank reactor, whose chemical kinetic model is based on the power law. The proposed methodology is compared with an input/output linearizing which achieve asymptotic and exponential closed-loop convergence, sliding-mode controller with a finite time convergence and an exact gradient optimal control to compare the time convergence performance. Numerical experiments show the satisfactory performance of the proposed controller, despite sustained disturbances in the concentration input feed.
Propargyloligosilazane matrixed composite for high temperature material combining polymer and ceramic properties
Authors: Xuan Lixin , Li Diansen , Wang Mingcun 
Published: February 2021

Abstract
A new single-phased thermosetting resin (propargyloligosilazane, POSZ) was prepared through Hofmann alkylation of oligosilazane with propargylbromide; the propargyl content in POSZ was controlled by monitoring the amount of propargylbromide in synthesis. The characterizations showed that POSZ has ideal rheology during material processing, the thermal curing temperature could be lowered when isocyanate was used as crosslinking agent, and the thermally cured POSZ can be pyrolyzed into anti-oxidative ceramic at a high yield of >70%. For POSZ-matrixed carbon-fabric laminate composite, it possessed high mechanical properties and retained the original shape with the increase of temperature as high as 800 °C. The POSZ-matrixed laminate has the mechanical properties combining polymer character at room temperature and ceramic character at high temperature, and it will find many prospective high temperature applications in need of polymer and ceramic properties simultaneously.
Determination of thermal, molecular changes, and functional properties in stabilized rice bran
Authors: Meral Raciye 
Published: February 2021

Abstract
In this study, stabilization was performed using three different oven temperatures (110, (T1) 130 (T2) and 150 °C(T3)) in the oven set at 10% moisture. The effect of stabilization on lipase activity, functional, and thermal properties of rice bran. Lipase activity of control (27.92 U/g) was to be higher than stabilized rice bran samples. Starch gelatinization peak temperature ranged from 70.05 (T3) to 85.09 °C (control). DPPH scavenging effect of control was 12.99 mmol TE. The highest DPPH radical scavenging effect value (15.72 mmol TE) was determined in the T3 sample. ABTS radical scavenging effect of stabilized samples significantly increased (p < 0.05) and the increase for T1, T2, and T3 was found to be 73, 75, and 77%, respectively. The highest ferulic (4284 μg/g) and p-coumaric acid (1180 μg/g) contents were determined in T3 and T1 samples, respectively. The content of bound ferulic and p-coumaric acids of stabilized rice bran samples was 2.41 and 2.33 times higher than control samples. While prolamine content was 3.38–4.18 mg/mL; glutelin content ranged from 4.45 to 5.11 mg/mL. An obvious state change during stabilization was observed in all samples around 70–85.9 °C. The results of the study revealed that stabilization might change the functional and thermal properties of rice bran.
Quantitative detection of soluble solids content, pH, and total phenol in Cabernet Sauvignon grapes based on near infrared spectroscopy
Authors: Luo Yijia , Dong Juan , Shi Xuewei , Wang Wenxia , Li Zhuoman , Sun Jingtao 
Published: February 2021

Abstract
Determination of Cabernet Sauvignon grapes quality plays an important role in commercial processing. In this research, a rapid approach based on near infrared spectroscopy was proposed to the determination of soluble solids content (SSC), pH, and total phenol content (TPC) in entire bunches of Cabernet Sauvignon grapes. Standardized normal variate (SNV) and competitive adaptive weighted sampling (CARS), genetic algorithm (GA), and synergy interval partial least squares (si-PLS) were used to optimize the spectral data. With optimal combination input, the prediction accuracy of partial least squares regression (PLSR) and support vector regression (SVR) models was compared. The results showed that these models based on variable optimization method could predict well the SSC, pH, and TPC of Cabernet Sauvignon grapes. The correlation coefficient of prediction for SSC, pH, and TPC had reached more than 0.85. This work provides an alternative to analyze the chemical parameters in whole bunch of Cabernet Sauvignon grape.
Drying characteristics and bioactivity evolution of Platycodon grandiflorum as affected by different microwave combined drying methods
Authors: Liu Yuan-Yuan , Lv Wei-Qiao , Lin Ruo-Hui , Li Dong , Wang Li-Jun 
Published: February 2021

Abstract
This study was to investigate the effect of different drying methods on the drying kinetics, physical properties, and bioactivity of Platycodon grandiflorum (PG). Four drying methods were employed to conduct the dehydrated process, namely, hot air drying (AD), vacuum drying (VD), microwave hot airflow rolling-bed drying (MHARD), and pulse-spouted microwave vacuum drying (PSMVD). PSMVD showed the highest drying rate among four drying methods based on the result of fitting first-order reaction model. And PSMVD-dried product showed higher rehydration ratio and better mechanical properties, suggesting a better rehydration characteristic. In addition, considering the content of Platycodin D, PSMVD is a promising drying technology for the dehydration of PG.
Diffusion-alloying sintering of Cr–Mo pre-alloyed iron powders with carbon: The effect of the carbon introduction method on the sinter’s properties
Authors: Anestiev Lubomir , Georgiev Jordan , Valkanov Seryozha , Selecká Marcela , Cherneva Sabine , Iankov Roumen 
Published: February 2021

Abstract
The influence of the carbon introduction method on the microstructure and the mechanical properties of sinters produced from iron-based powders by diffusion-alloying sintering has been studied. Two methods of carbon introduction were tested: (1) Premixing of the base powder with graphite, and (2) Coating of the base powder with a carbon-containing substance. The results obtained could be summarized as (1) The microstructure and the mechanical properties depend on the method of carbon introduction; (2) The sinters produced from coated powders possess finer micro-structure, improved homogeneity, and in two out of three of the studied compositions, better mechanical properties. Based on the results obtained, a reasonable assumption was made that the method of carbon introduction affects the dissolution rate of the carbon additive, thus affecting the micro-structure and the mechanical properties of the sinter.
Predicting doped Fe-based superconductor critical temperature from structural and topological parameters using machine learning
Authors: Zhang Yun , Xu Xiaojie 
Published: February 2021

Abstract
Recently, Fe-based superconductors have shown promising properties of high critical temperature and high upper critical fields, which are prerequisites for applications in high-field magnets. Critical temperature, T
c, is an important characteristic correlated with crystallographic and electronic structures. By doping with foreign ions in the crystal structure, T
c can be modified, which however requires significant manpower and resources for materials synthesis and characterizations. In this study, we develop the Gaussian process regression model to predict T
c of doped Fe-based superconductors based on structural and topological parameters, including the lattice constants, volume, and bonding parameter topological index H
31. The model is stable and accurate, contributing to fast T
c estimations.
Dynamics of a stochastic susceptible-infective-recovered (SIRS) epidemic model with vaccination and nonlinear incidence under regime switching and Lévy jumps
Authors: Hu Junna , Wen Buyu , Zeng Ting , Teng Zhidong 
Published: February 2021

Abstract
In this paper, a stochastic susceptible-infective-recovered (SIRS) epidemic model with vaccination, nonlinear incidence and white noises under regime switching and Lévy jumps is investigated. A new threshold value is determined. Some basic assumptions with regard to nonlinear incidence, white noises, Markov switching and Lévy jumps are introduced. The threshold conditions to guarantee the extinction and permanence in the mean of the disease with probability one and the existence of unique ergodic stationary distribution for the model are established. Some new techniques to deal with the Markov switching, Lévy jumps, nonlinear incidence and vaccination for the stochastic epidemic models are proposed. Lastly, the numerical simulations not only illustrate the main results given in this paper, but also suggest some interesting open problems.
Design of the state feedback-based feed-forward controller asymptotically stabilizing the double-pendulum-type overhead cranes with time-varying hoisting rope length
Authors: Vrabel Robert 
Published: February 2021

Abstract
In this paper we focus our attention on the design of the feedback-based feed-forward controller asymptotically stabilizing the double-pendulum-type (D-P-T) crane system with the time-varying rope length in the desired end position of payload (the origin of the coordinate system). In principle, two cases are considered, in the first case, the sway angle of payload is uncontrolled and second case, when the sway angle of payload is controlled by an external force. Precise mathematical modeling in the framework of Lagrange formalism without the traditional neglect of the important structural parameters of the D-P-T crane system and numerical simulation in the Matlab environment indicate the substantial reduction of the transportation time to the desired end position.
Invariant solutions of fractional-order spatio-temporal partial differential equations
Authors: Mnguni Nkosingiphile , Jamal Sameerah 
Published: February 2021

Abstract
This paper considers two categories of fractional-order population growth models, where a time component is defined by Riemann–Liouville derivatives. These models are studied under the Lie symmetry approach, and we reduce the fractional partial differential equations to nonlinear ordinary differential equations. Subsequently, solutions of the latter are determined numerically or with the aid of Laplace transforms. Graphical representations for integral and trigonometric solutions are presented. A key feature of these models is the connection between spatial patterning of organisms versus competitive coexistence.
An exploratory study on pro-drop in a written description task in L2 Spanish
Authors: Vande Casteele An , Palomares Ortiz Alejandro 
Published: February 2021

Abstract
The present article aims at investigating the pro-drop phenomenon in L2 Spanish. The phenomenon of pro-drop or null subject is a typological feature of some languages, which are characterized by an implicit subject in cases of topic continuity. More specifically, behaviour regarding subject (dis)continuity in Spanish differs from French. This paper will offer a contrastive analysis on subject realisation by French learners of L2 Spanish compared to L1 Spanish speakers. So, the goal of this pilot study is to see if a different functioning in pro-drop in the mother tongue also influences the L2. The study is based upon a written description task presented to the two groups of participants: the experimental group of French mother tongue L2 Spanish language learners and the control group of Spanish native speakers.