bluuebunny/crossref_metadata_2025 huggingface dataset:
Endovascular treatment of bilateral intracranial vertebral artery aneurysms: an algorithm based on a 10-year neurointerventional experience
Authors: Zhang Yisen , Tian Zhongbin , Zhu Wei , Liu Jian , Wang Yang , Wang Kun , Zhang Ying , Yang Xinjian , Li Wenqiang
Published: August 2020

Background

The management of bilateral intracranial vertebral artery dissecting aneurysms (IVADAs) is controversial, and requires the development of endovascular treatment modalities and principles. We aim to investigate the endovascular treatment strategy and outcomes of bilateral IVADAs.

Methods

We identified all bilateral IVADAs at a high-volume neurointerventional centre over a 10-year period (from January 2009 to December 2018). Radiographic and clinical data were recorded, and a treatment algorithm was derived.

Results

Twenty-seven patients with bilateral IVADAs (54 IVADAs in total, 51 unruptured, 3 ruptured) were diagnosed. Four patients (14.8%) received single-stage endovascular treatment, 12 patients (44.4%) with staged endovascular treatment and 11 patients (40.8%) with unilateral endovascular treatment of bilateral IVADAs. Thirty-six IVADAs (85.7%) have complete obliteration at the follow-up angiography. Two of three ruptured IVADAs with stent-assisted coiling recanalised, and had further recoiling. Three patients (11.1%) have intraprocedural or postprocedural complications (two in single-stage and one in staged). Twenty-five patients (92.6%) had a favourable clinical outcome, and two patients (7.4%, all in single-stage) showed an unfavourable clinical outcome at follow-up. For the patients with unilateral reconstructive endovascular treatment, the contralateral untreated IVADAs were stable and had no growth or ruptured during follow-up period. None of all IVADAs had rebleeding during the clinical follow-up.

Conclusions

Endovascular treatment can be performed in bilateral IVADAs with high technical success, high complete obliteration rates and acceptable morbidity/mortality. Contralateral IVADAs had low rates of aneurysm growth and haemorrhage when treated in a staged/delayed fashion.
Chinese Stroke Association guidelines for clinical management of cerebrovascular disorders: executive summary and 2019 update of the management of high-risk population
Authors: Wang Yilong , Han Shangrong , Qin Haiqiang , Zheng Huaguang , Jiang Bin , Cao Yong , Gao Yuan , Guan Ling , Jia Qian , Jiang Yong , Jiao Yuming , Li Shuya , Li Yapeng , Li Zixiao , Liu Wei , Ru Xiaojuan , Sun Dongling , Sun Haixin , Wang Penglian , Wang Tingting , Zong Lixia , Guo Lei , Xie Xuewei , Xu Yuming , Xu Yuyuan , Yang Xiaomeng , Yang Yingying , Zhou Mengyuan , Wang Wenzhi
Published: August 2020

Aim

Cerebrovascular disease is the leading cause of death and disability in China, causing a huge burden among patients and their families. Hence, stroke prevention is critical, especially in the high-risk population. Here, we present the evidence-based guideline suitable for the Chinese population.

Methods

Literature search of PubMed and Cochrane library (from January 1964 to June 2019) was done. After thorough discussion among the writing group members, recommendations were listed and summarised. This guideline was reviewed and discussed by the fellow writing committees of the Chinese Stroke Association’s Stroke.

Results

This evidence-based guideline was written in three parts: controlling the risk factors of stroke, utilisation of antiplatelet agents and assessing the risks of first-ever stroke. All recommendations were listed along with the recommending classes and levels of evidence.

Conclusions

This guideline provides recommendations for primary prevention of cerebrovascular disease among high-risk population in China. Controlling related risk factors, appropriately using antiplatelet agents, assessing the risk of developing first-ever stroke should help reduce the rate of cerebrovascular disease in China.
Modifications to gravitational wave equation from canonical quantum gravity
Authors: Dapor Andrea , Liegener Klaus
Published: August 2020

It is expected that the quantum nature of spacetime leaves its imprint in all semiclassical gravitational systems, at least in certain regimes, including gravitational waves. In this paper we investigate such imprints on gravitational waves within a specific framework: space is assumed to be discrete (in the form of a regular cubic lattice), and this discrete geometry is quantised following Dirac’s canonical quantisation scheme. The semiclassical behavior is then extracted by promoting the expectation value of the Hamiltonian operator on a semiclassical state to an effective Hamiltonian. Considering a family of semiclassical states representing small tensor perturbations to Minkowski background, we derive a quantum-corrected effective wave equation. The deviations from the classical gravitational wave equation are found to be encoded in a modified dispersion relation and controlled by the discreteness parameter of the underlying lattice. For finite discretisations, several interesting effects appear: we investigate the thermodynamical properties of these modified gravitons and, under certain assumptions, derive the tensor power spectrum of the cosmic microwave background. The latter is found to deviate from the classical prediction, in that an amplification of UV modes takes place. We discuss under what circumstances such effect can be in agreement with observations.
Positivity of vector bundles on homogeneous varieties
Authors: Biswas Indranil , Hanumanthu Krishna , Nagaraj D. S.
Published: August 2020

We study the following question: Given a vector bundle on a projective variety [Formula: see text] such that the restriction of [Formula: see text] to every closed curve [Formula: see text] is ample, under what conditions [Formula: see text] is ample? We first consider the case of an abelian variety [Formula: see text]. If [Formula: see text] is a line bundle on [Formula: see text], then we answer the question in the affirmative. When [Formula: see text] is of higher rank, we show that the answer is affirmative under some conditions on [Formula: see text]. We then study the case of [Formula: see text], where [Formula: see text] is a reductive complex affine algebraic group, and [Formula: see text] is a parabolic subgroup of [Formula: see text]. In this case, we show that the answer to our question is affirmative if [Formula: see text] is [Formula: see text]-equivariant, where [Formula: see text] is a fixed maximal torus. Finally, we compute the Seshadri constant for such vector bundles defined on [Formula: see text].
The cooperative and competitive mechanisms of a leader’s opinion transmission
Authors: Amirjanov Adil
Published: August 2020

The paper modeled a leader’s opinion transmission in a population. The proposed model develops the cooperation agent-based continuous model in which the cooperation of individuals is based on the similarity of evolved “tags” which are relative to evolved tag-difference tolerances. In proposed model, an individual’s opinion and the individual’s tolerance are specified as variables in the model. During communication with each other and with a leader, the resources of individuals are incremented, if they are tolerable to the opinions of their opponents. An opinion formation in population is established by a cooperative process — changing individual’s opinion, if the individual is tolerable to the opinions of opponents, and by a competitive process — copying opinions and tolerances of successful individuals who have higher resource. Numerical experiments have proven that the public opinion reached a consensus followed the leader’s opinion.
Aircraft approaching service of terminal control based on fuzzy control
Authors: Su Te-Jen , Lo Kun-Liang , Lee Feng-Chun , Chang Yuan-Hsiu
Published: August 2020

Aircraft approaching is the most dangerous phase in every complete flight. To solve the pressure of air traffic controllers and the landings delayed problems caused by the huge air traffic flow in Terminal Control Area (TCA), an automatic Air Traffic Control (ATC) instructions system is initially designed in this paper. It applies the fuzzy theory to make instant and appropriate decisions which can be transmitted via Controller-Pilot Datalink Communications (CPDLC). By means of the designed system, the decision-making time can be saved and the human factors can be reduced to avoid the flight accidents and further delays in aircraft approaching.
Comparative study of low-frequency vibrations assigned to a workpiece in EDM and PMEDM
Authors: Le Quang Dung , Nguyen Huu Phan , Banh Tien Long , Nguyen Duc Toan
Published: August 2020

This study deals about the influence of vibrations incorporated into a workpiece during powder-mixed electrical discharge machining (PMEDM) on quality measures such as material removal rate (MRR), surface roughness [Formula: see text] and microhardness. It has been found that the low-frequency vibration incorporated into the workpiece positively affects the processing efficiency of electrical discharge machining (EDM) and PMEDM. However, the effect of low-frequency vibration in PMEDM has been better than EDM. The higher vibration frequency significantly improves the MRR and [Formula: see text] in PMEDM. The MRR has been improved by 95.89% and with lower [Formula: see text] of 63.2% in PMEDM. The hardness of the machined surface after PMEDM using titanium powder mixed in dielectric liquid was increased approximately two times as compared with conventional EDM.
A study on the vibrations in the external cylindrical grinding process of the alloy steels
Authors: Nguyen Tuan-Linh , Nguyen Nhu-Tung , Hoang Long
Published: August 2020

The vibration during external cylindrical grinding is caused by many factors such as the rigidity of the technology system, machining modes, machining materials, cooling mode, etc. This paper employed a Taguchi method to design experiments and evaluate the influence of machining mode parameters and workpiece material hardness on the vibrations when machining some types of alloy steel in external cylindrical grinding process. The influence of machining conditions on the vibrations was investigated. Besides, the mathematical models of vibration amplitudes were also modeled. The achieved results can be used to control the vibrations through machining conditions to improve the surface quality of the product.
Behavioral modeling of current conveyors for circuit simulation
Authors: Jeang Ta-Chi , Cai Hong-Qi , Yang Chih-Chin , Shen Chih-Lung , Wang Hung-Yu
Published: August 2020

Behavior models are proposed for HSPICE simulation of first-, second- and third-generation current conveyors. They can be used to speed up the exploration and verification of current conveyor-based circuit designs. To demonstrate the feasibility and workability of the proposed HSPICE simulation models, they are used as the current measuring devices for grounded and floating current sensing, and the simulation results are consistent with the theoretical expectation. The flexibility in the current sensing capability of the CCIII is also shown by a practical example using the behavior model. HSPICE simulation results are given.
Analytic infinite derivative gravity, R2-like inflation, quantum gravity and CMB
Authors: Koshelev Alexey S. , Kumar K. Sravan , Starobinsky Alexei A.
Published: August 2020

Emergence of [Formula: see text] inflation, which is the best fit framework for CMB observations till date, comes from the attempts to attack the problem of quantization of gravity which in turn have resulted in the trace anomaly discovery. Further developments in trace anomaly and different frameworks aiming to construct quantum gravity indicate an inevitability of nonlocality in fundamental physics at small time and length scales. A natural question would be to employ the [Formula: see text] inflation as a probe for signatures of nonlocality in the early Universe physics. Recent advances of embedding [Formula: see text] inflation in a string theory inspired nonlocal gravity modification provide very promising theoretical predictions connecting the nonlocal physics in the early Universe and the forthcoming CMB observations.
Information loss paradox revisited: Farewell firewall?
Authors: Gan Wen-Cong , Shu Fu-Wen
Published: August 2020

Unitary evolution makes pure state on one Cauchy surface evolve to pure state on another Cauchy surface. Outgoing Hawking radiation is the only subsystem on the late Cauchy surface. The requirement that Hawking radiation should be pure amounts to requiring purity of the subsystem when the total system is pure. We will see that this requirement will lead to firewall even in flat spacetime, and thus is invalid. Information is either stored in the entanglement between field modes inside black hole and the outgoing modes or stored in correlation between geometry and Hawking radiation when singularity is resolved by quantum gravity effects. We will give a simple argument that even in semi-classical regime, information is (at least partly) stored in correlation between geometry and Hawking radiation.
Deformations of Courant pairs and Poisson algebras
Authors: Mandal Ashis , Mishra Satyendra Kumar
Published: August 2020

We study the deformation of Courant pairs with a commutative algebra base. We consider the deformation cohomology bi-complex and describe a universal infinitesimal deformation. In a sequel, we formulate an extension of a given deformation of a Courant pair to another with extended base, which leads to describe the obstruction in extending a given deformation. We also discuss the construction of versal deformation of Courant pairs. As an application, we compute universal infinitesimal deformation of Poisson algebra structures on the three-dimensional complex Heisenberg Lie algebra. We compare the second deformation cohomology spaces of these Poisson algebra structures by considering them in the category of Leibniz pairs and Courant pairs, respectively.
PPG-BASED AUTOMATED ESTIMATION OF BLOOD PRESSURE USING PATIENT-SPECIFIC NEURAL NETWORK MODELING
Authors: CHAKRABORTY ABHISHEK , SADHUKHAN DEBOLEENA , PAL SAURABH , MITRA MADHUCHHANDA
Published: August 2020

Recently, photoplethysmography (PPG)-based techniques have been extensively used for cuff-less, automated estimation of blood pressure because of their inexpensive and effortless acquisition technology compared to other conventional approaches. However, most of the reported PPG-based, generalized BP estimation methods often lack the desired accuracy due to pathophysiological diversity. Moreover, some methods rely on several correction factors, which are not globalized yet and require further investigation. In this paper, a simple and automated systolic (SBP) and diastolic (DBP) blood pressure estimation method is proposed based on patient-specific neural network (NN) modeling. Initially, 15 time-plane PPG features are extracted and after feature selection, only four selected features are used in the NN model for beat-to-beat estimation of SBP and DBP, respectively. The proposed technique also presents reasonable accuracy while used for generalized estimation of BP. Performance of the algorithm is evaluated on 670 records of 50 intensive care unit (ICU) patients taken from MIMIC, MIMIC II and MIMIC Challenge databases. The proposed algorithm exhibits high average accuracy with (mean[Formula: see text][Formula: see text][Formula: see text]SD) of the estimated SBP as ([Formula: see text]) mmHg and DBP as ([Formula: see text]) mmHg. Compared to the other generalized models, the use of patient-specific approach eliminates the necessity of individual correction factors, thus increasing the robustness, accuracy and potential of the method to be implemented in personal healthcare applications.
Direct interaction network inference for compositional data via codaloss
Authors: Chen Liang , He Shun , Zhai Yuyao , Deng Minghua
Published: August 2020

16S rRNA gene sequencing and whole microbiome sequencing make it possible and stable to quantitatively analyze the composition of microbial communities and the relationship among microbial communities, microbes, and hosts. One essential step in the analysis of microbiome compositional data is inferring the direct interaction network among microbial species, bringing to light the potential underlying mechanism that regulates interaction in their communities. However, standard statistical analysis may obtain spurious results due to compositional nature of microbiome data; therefore, network recovery of microbial communities remains challenging. Here, we propose a novel loss function called codaloss for direct microbes interaction network estimation under the sparsity assumptions. We develop an alternating direction optimization algorithm to obtain sparse solution of codaloss as estimator. Compared to other state-of-the-art methods, our model makes less assumptions about the microbial networks. The simulation and real microbiome data results show that our method outperforms other methods in network inference. An implementation of codaloss is available from https://github.com/xuebaliang/Codaloss .
Scattering for the one-dimensional Klein–Gordon equation with exponential nonlinearity
Authors: Ikeda Masahiro , Inui Takahisa , Okamoto Mamoru
Published: August 2020

We consider the asymptotic behavior of solutions to the Cauchy problem for the defocusing nonlinear Klein–Gordon equation (NLKG) with exponential nonlinearity in the one spatial dimension with data in the energy space [Formula: see text]. We prove that any energy solution has a global bound of the [Formula: see text] space-time norm, and hence, scatters in [Formula: see text] as [Formula: see text]. The proof is based on the argument by Killip–Stovall–Visan (Trans. Amer. Math. Soc. 364(3) (2012) 1571–1631). However, since well-posedness in [Formula: see text] for NLKG with the exponential nonlinearity holds only for small initial data, we use the [Formula: see text]-norm for some [Formula: see text] instead of the [Formula: see text]-norm, where [Formula: see text] denotes the [Formula: see text]th order [Formula: see text]-based Sobolev space.
Influence of strong time-dependent oscillations in semilinear damped wave models
Authors: Aslan Halit Sevki , Reissig Michael
Published: August 2020

We study the global (in time) existence of small data solutions to some Cauchy problems for semilinear damped wave models with strong time-dependent oscillations. The goal is to understand the influence of strong oscillations in the coefficients on solutions to some semilinear models with an “effective-like” damping term, where the data are supposed to belong to different classes of regularity.
A semiparametric model for matrix regression
Authors: Zhao Weihua , Zhang Xiaoyu , Lian Heng
Published: August 2020

We focus on regression problems in which the predictors are naturally in the form of matrices. Reduced rank regression and related regularized method have been adapted to matrix regression. However, linear methods are restrictive in their expressive power. In this work, we consider a class of semiparametric additive models based on series estimation of nonlinear functions which interestingly induces a problem of 3rd order tensor regression with transformed predictors. Risk bounds for the estimator are derived and some simulation results are presented to illustrate the performances of the proposed method.
Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK
Authors: Catlos Elizabeth J. , Mark Darren F. , Suarez Stephanie , Brookfield Michael E. , Miller C. Giles , Schmitt Axel K. , Gallagher Vincent , Kelly Anne
Published: August 2020

The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assemblage of fish scales. Units above provide insights into the early evolution of animal and plant life. The bed has not yet been radioisotopically dated. Here, we report 207 secondary ion mass spectrometry (SIMS) ages from 102 zircon (ZrSiO
4
) grains from the Ludlow (
n
 = 2) and stratigraphically higher Downton (
n
 = 1) bone beds. SIMS ages are middle Ordovician (471.6 ± 20.7 Ma) to late Devonian (375.7 ± 14.6 Ma,
238
U–
206
Pb, ±1σ analytical uncertainty). Cathodoluminescence images show that the youngest ages appear affected by alteration. Chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) U–Pb geochronology was utilized to improve precision. Detrital zircon grains from Downton yield 424.91 ± 0.34/0.42/0.63 Ma and from Ludlow 424.85 ± 0.32/0.41/0.62 Ma (
n
 = 5 each,
238
U–
206
Pb, ±2σ analytical, tracer or systematic uncertainty). These ages provide a maximum deposition age. Results overlap the basal Přídolí age (423.0 ± 2.3 Ma) in its stratotype (Požáry Section, Reporyje, Prague, Czech Republic). The Ludlow Bone Bed marks the base of the local Downton Group, which has previously been correlated with the base of the Přídolí Series. The CA-ID-TIMS ages are older than those for other land arthropod-bearing sediments, such as the Cowie Harbour Fish Bed and Rhynie Chert.

Supplementary material:
An Excel file containing detailed information on the SIMS analyses, a figure showing calibration curves for AS3 standards sputtered over sessions 1 and 2, and a figure showing CA-ID-TIMS U–Pb age data (concordia and weighted mean plots) are available at
https://doi.org/10.6084/m9.figshare.c.5087031
Predator Effects on Plant-Pollinator Interactions, Plant Reproduction, Mating Systems, and Evolution
Authors: Benoit Amanda D. , Kalisz Susan
Published: August 2020

Plants are the foundation of the food web and therefore interact directly and indirectly with myriad organisms at higher trophic levels. They directly provide nourishment to mutualistic and antagonistic primary consumers (e.g., pollinators and herbivores), which in turn are consumed by predators. These interactions produce cascading indirect effects on plants (either trait-mediated or density-mediated). We review how predators affect plant-pollinator interactions and thus how predators indirectly affect plant reproduction, fitness, mating systems, and trait evolution. Predators can influence pollinator abundance and foraging behavior. In many cases, predators cause pollinators to visit plants less frequently and for shorter durations. This decline in visitation can lead to pollen limitation and decreased seed set. However, alternative outcomes can result due to differences in predator, pollinator, and plant functional traits as well as due to altered interaction networks with plant enemies. Furthermore, predators may indirectly affect the evolution of plant traits and mating systems.
Urban Climates and Climate Change
Authors: Masson Valéry , Lemonsu Aude , Hidalgo Julia , Voogt James
Published: August 2020

Cities are particularly vulnerable to extreme weather episodes, which are expected to increase with climate change. Cities also influence their own local climate, for example, through the relative warming known as the urban heat island (UHI) effect. This review discusses urban climate features (even in complex terrain) and processes. We then present state-of-the-art methodologies on the generalization of a common urban neighborhood classification for UHI studies, as well as recent developments in observation systems and crowdsourcing approaches. We discuss new modeling paradigms pertinent to climate impact studies, with a focus on building energetics and urban vegetation. In combination with regional climate modeling, new methods benefit the variety of climate scenarios and models to provide pertinent information at urban scale. Finally, this article presents how recent research in urban climatology contributes to the global agenda on cities and climate change.
Credit Default Swaps: A Primer and Some Recent Trends
Authors: Lando David
Published: August 2020

The credit default swap (CDS) remains an important class of derivatives contract despite the declining activity in the single-name corporate market. I provide a quick introduction to the contracts, the pricing formula used to interpret the market premiums, the development in trading volumes, and some key insights that are important for understanding its role in markets. I then take a closer look at the CDS-bond basis and the role of trading and regulatory frictions. Finally, the European sovereign debt crisis brought back in focus the notion of a quanto spread, which I explain.
Using exam reflections to augment learning
Authors: Gorres-Martens Brittany K.
Published: August 2020

While teaching, learning, and assessment should undoubtedly encompass more than just focusing on student exam scores, exams are a pervasive assessment tool at many academic institutions. This paper describes a newly developed exam reflection assignment, which is a tool to assist students in successful exam experiences throughout the course. The exam reflection is described and compared and contrasted to other types of exam reflections.
Comparative Evaluation and Measure of Accuracy of ELISAs, CLIAs, and ECLIAs for the Detection of HIV Infection among Blood Donors in China
Authors: Chang Le , Zhao Junpeng , Guo Fei , Ji Huimin , Zhang Lu , Jiang Xinyi , Wang Lunan
Published: August 2020

Background. Enzyme-linked immunosorbent assay (ELISA) is the only serological method approved for blood screening in China. Automated chemiluminescence immunoassay (CLIA) and electrochemiluminescence immunoassay (ECLIA) had been used in clinical laboratories but not applied to screen HIV among blood donors. This study aimed to evaluate the performance of ELISA, CLIA, and ECLIA, focusing on the feasibility of CLIA/ECLIA for blood screening. Method. 1029 blood donations from 14 blood centers screened by ELISA were enrolled in the study. All plasma samples were tested by eight ELISA assays in 16 blood centers, followed by the detection of CLIA and ECLIA methods in the National Center for Clinical Laboratories (NCCL), further confirmed by nucleic acid testing (NAT) and Western blot (WB). Results. Of 1029 samples, 136 were confirmed as HIV positive. CLIA and ECLIA assay had similar sensitivities with ELISAs but showed higher specificity (CLIA: 99.1%, 885/893; ECLIA: 99.0%, 884/893), concordance rate (CLIA: 99.2%, 1021/1029; ECLIA: 99.1%, 1020/1029), and positive predictive value (PPV) (CLIA: 94.4%, 136/144; ECLIA: 93.8%, 136/145) than most of ELISA kits (>5 ELISAs) (P<0.05). Kappa values of CLIA (0.967) and ECLIA (0.963) were the highest among all the serologic assays. Among 451 samples with initial ELISA reactivity, 315 were negatives, of which 307 (97.5%) and 306 (97.1%) were detected as nonreactive by CLIA (8 nonspecific reactions) and ECLIA (9 nonspecific reactions), respectively. Conclusion. Compared with ELISA, CLIA and ECLIA are more specific and accurate in detecting HIV antibody/antigen and can keep more nonspecifically reactive donors detected by ELISA. CLIA and ECLIA can be used for the improvement of serological blood screening strategy to avoid the unnecessary loss of blood donors.
The Development and Application of a Base Editor in Biomedicine
Authors: Wang Fang , Zeng Yuqiang , Wang Yi , Niu Yuyu
Published: August 2020

Using a base editor to generate monogenic disease models and correct pathogenic point mutations is a breakthrough technology for exploration and treatment of human diseases. As a burgeoning approach for genomic modification, the fused CRISPR/Cas9 with various deaminase separately has significantly increased the efficiency of producing a precise point mutation with minimal insertions or deletions (indels). Along with the flexibility and efficiency, a base editor has been widely used in many fields. This review discusses the recent development of a base editor, including evolution and advance, and highlights the applications and challenges in the field of gene therapy. Depending on rapid improvement and optimization of gene editing technology, the prospect of base editor is immeasurable.
Natural Antioxidants: A Review of Studies on Human and Animal Coronavirus
Authors: Diniz Lúcio Ricardo Leite , Bezerra Filho Carlos da Silva Maia , Fielding Burtram C. , de Sousa Damião Pergentino
Published: August 2020

The outbreaks of viruses with wide spread and mortality in the world population have motivated the research for new therapeutic approaches. There are several viruses that cause a biochemical imbalance in the infected cell resulting in oxidative stress. These effects may be associated with the development of pathologies and worsening of symptoms. Therefore, this review is aimed at discussing natural compounds with both antioxidant and antiviral activities, specifically against coronavirus infection, in an attempt to contribute to global researches for discovering effective therapeutic agents in the treatment of coronavirus infection and its severe clinical complications. The contribution of the possible action of these compounds on metabolic modulation associated with antiviral properties, in addition to other mechanisms of action, is presented.
Some Properties of Kantorovich-Stancu-Type Generalization of Szász Operators including Brenke-Type Polynomials via Power Series Summability Method
Authors: Braha Naim Latif , Mansour Toufik , Mursaleen Mohammad
Published: August 2020

In this paper, we study the Kantorovich-Stancu-type generalization of Szász-Mirakyan operators including Brenke-type polynomials and prove a Korovkin-type theorem via the T-statistical convergence and power series summability method. Moreover, we determine the rate of the convergence. Furthermore, we establish the Voronovskaya- and Grüss-Voronovskaya-type theorems for T-statistical convergence.
An Experimental Study on Coal Fines Migration during Single Phase Water Flow
Authors: Han Wenlong , Wang Yanbin , Fan Jingjing , Li Yong , Wu Xiang , Yu Yun
Published: August 2020

Coal fines migration and intrusion in coal fractures affect coalbed methane (CBM) wells performance by reducing reservoir permeability and production continuity. Physical simulations are conducted to investigate the permeability variation under different diameter coal fines intrusion at various flow velocities and confining pressures. The results show that the conductivity of fractures is dramatically reduced and hardly recover to its initial condition after coal fines intrusion. The permeability after coal fines intrusion (Pcfi) has no direct correlation with the increase of flooding velocity, while decreases with the increase of confining pressures. The fractures can be totally blocked by coal fines, while penetration also happened during the flooding process, causing permeability fluctuation. The permeability loss rates value for 80-120 mesh coal fines intrusion are generally <60% compared with the initial permeability, including the flow velocity of 2, 3, 4, 6, 8, and 10 mL/min with confining pressure of 6 MPa and the confining pressure of 2, 3, 4, 5, and 6 MPa with flow velocity of 3 mL/min. However, under 120+ mesh coal fines condition, the permeability loss rates are higher than 85% under most flow velocities and confining pressures. When coal fines become smaller, the permeability loss rates decrease to be lower than 45%, and part the coal fines are discharged with the water flow. Thus, coal fines proper dischargement can partly maintain the reservoir permeability during coalbed methane production. The results would be useful in understanding coal fines intrusion behaviors and its controlling strategies during CBM drainage.
The Petri Dish-N2B27 Culture Condition Maintains RPE Phenotype by Inhibiting Cell Proliferation and mTOR Activation
Authors: Lou Hui , Lian Chunpin , Shi Fanjun , Chen Liqun , Qian Sicheng , Wang Hui , Zhao Xiaoyun , Ji Xiaoyan , Zhang Jingfa , Xu Guoxu
Published: August 2020

Objective. To develop a method for the rapid isolation of rat RPE cells with high yield and maintain its epithelial state in modified culture system. Methods. The eyeballs were incubated with dispase. The retina was isolated with RPE attached and cut into several pieces. Following a brief incubation in growth medium, large RPE sheets can be harvested rapidly. RPE cells were divided into four groups and cultured for several weeks, that is, (1) in cell culture dishes with 10% FBS containing medium (CC dish-FBS), (2) in petri dishes with 10% FBS containing medium (Petri dish-FBS), (3) in cell culture dishes with N2 and B27 containing medium (CC dish-N2B27), and (4) in petri dishes with N2 and B27 containing medium (Petri dish-N2B27). Morphological and biological characteristics were investigated using light microscopy, Q-PCR, and western blot. Results. The retina would curl inwardly during the growth medium incubation period, releasing RPE sheets in the medium. Compared with low density group (5,000 cells/cm2), RPE cells plated at high density (15,000 cells/cm2) can maintain RPE morphology for a more extended period. Meanwhile, plating RPE cells at low density significantly reduced the expression of RPE cell type-specific genes (RPE65, CRALBP, and bestrophin) and increased the expression of EMT-related genes (N-cadherin, fibronectin, and α-SMA), in comparison with the samples from the high density group. The petri dish culture condition reduced cell adhesion and thus inhibited RPE cell proliferation. As compared with other culture conditions, RPE cells in the petri dish-N2B27 condition could maintain RPE phenotype with increased expression of RPE-specific genes and decreased expression of EMT-related genes. The AKT/mTOR pathway was also decreased in petri dish-N2B27 condition. Conclusion. The current study provided an alternative method for easy isolation of RPE cells with high yield and maintenance of its epithelial morphology in the petri dish-N2B27 condition.
Constant Frequency Control Strategy of Microgrids by Coordinating Energy Router and Energy Storage System
Authors: Lan Zheng , Wang Junzhang , Zeng Jinhui , He Dong , Xiao Fan , Jiang Fei
Published: August 2020

In this paper, a constant frequency control strategy of a microgrid by coordinating energy router (ER) and energy storage system is proposed to solve the frequency fluctuation problem of microgrid, in which ER is the core of the energy management system. The interface converter of ER connected to the microgrid adopts the virtual synchronous generator (VSG) control, which adjusts the mechanical reference power in real time according to the state of charge (SOC) of the energy storage. The energy storage system adopts constant voltage and constant frequency (V/F) control to maintain the frequency and voltage stability of microgrid. The energy storage system with fast charge and discharge responds to the power fluctuation of the microgrid. ER maintains the stability of the energy storage capacity through bidirectional power regulation. When the energy storage system fails, the frequency and voltage droop characteristics of ER controlled by VSG will play a role in maintaining the stable operation of the microgrid. By the coordinating control strategy, the maximum efficiency of intermittent distributed energy can be guaranteed, and the stability, reliability, and grid-connection friendliness of the microgrid operation can be improved. Simulation results prove the effectiveness of the proposed control strategy.
Inconclusive Syphilis Results: A Retrospective Review of Public Health Results
Authors: O’Byrne Patrick , Tilley Leslie , Friedman Dara Spatz , Orser Lauren
Published: August 2020

In the context of increasing syphilis incidence in many Western countries, we sought to better understand the frequency and outcomes associated with inconclusive serologic syphilis results. To accomplish this, we reviewed all inconclusive results that arose from an indeterminant confirmatory treponemal screen (specifically the Treponema pallidum particulate agglutination test), which were reported to Ottawa Public Health from January 1, 2019, through December 31, 2019. Our case review identified that 52 persons generated such test results during the study period, of whom 44.4% were cases requiring treatment, 46.3% were persons without new risk factors or symptoms of syphilis who had been previously treated for this infection, and 9.3% were not syphilis. Overall, these untreated syphilis cases accounted for 8.6% of all new syphilis diagnoses in our local jurisdiction during the study period. These results highlight that case investigation and prompt management of inconclusive syphilis results is an appropriate public health and clinical approach and that such a strategy could contribute to efforts to reduce increasing syphilis incidence.
Combined Effects of Graphite Tailings and Curing Conditions on the Early‐Age Performances of Cement Mortar
Authors: Liu Hongbo , Zhang Yuxin , Li Ben , Wang Zhongrui
Published: August 2020

In this study, the combined effects of different amounts of graphite tailings (GT) as a substitute for sand and three cure methods on the early‐age mechanical and material performances of cement mortar have been investigated. The results can be concluded that graphite tailings and hot‐water cure method can effectively improve the early strength of cement‐based materials and facilitate the formation of high‐density calcium silicate hydrate (C‐S‐H), more Ca(OH)2 (CH), and other hydration products. Simultaneously, the pore structure distribution in the cement mortar is improved to be finer. Finally, this paper explains the mechanism of GT and hot‐water curing (HWC) method on early‐age performances of the cement mortar through the graphic model and provides the basis for selecting the GT and HWC method on improving early performance requirements for special engineering or rapid repair engineering through the proposed comprehensive quantitative calculation model.
Analysis on Existence of Positive Solutions for a Class Second Order Semipositone Differential Equations
Authors: Wang Yunhai , Yang Xu
Published: August 2020

In this paper, we study the existence of positive solutions of the following second-order semipositone system (see equation 1). By applying a well-known fixed-point theorem, we prove that the problem admits at least one positive solution, if f is bounded below.
Transcriptomics Study to Determine the Molecular Mechanism by which sIL‐13Rα2‐Fc Inhibits Caudal Intervertebral Disc Degeneration in Rats
Authors: Wang Xin , Tan Jianshi , Sun Junhao , Fang Pengzhong , Chen Jinlei , Yuan Wen , Chen Huajiang , Liu Yang
Published: August 2020

Background. Intervertebral disc degeneration is related to tissue fibrosis. ADAMTS can degrade the important components of the ECM during the process of intervertebral disc degeneration, ultimately resulting in the loss of intervertebral disc function. sIL‐13Rα2‐Fc can inhibit fibrosis and slow down the degeneration process, but the mechanism involved remains unclear. Objective. To determine the mechanism by which sIL‐13Rα2‐Fc inhibits ECM degradation and reduces intervertebral disc tissue fibrosis using a transcriptomics analysis. Methods. A rat model of caudal intervertebral disc degeneration was established, and Sirius red staining was used to observe the pathological changes in the caudal intervertebral disc. Transcriptome sequencing was employed to assess the gene expression profiles of the intervertebral disc tissues in the model group and the sIL‐13Rα2‐Fc‐treated group. Differentially expressed genes were identified and analyzed using GO annotation and KEGG pathway analyses. Real‐time fluorescence quantitative PCR was used to verify the expression levels of candidate genes. The levels of GAG and HA were quantitatively assessed by ELISA, and the levels of collagen I and collagen II were analyzed by western blotting. Results. Sirius red staining showed that in the model group, the annulus fibrosus was disordered, the number of breaks increased, and the type I collagen protein levels increased, whereas in the sIL‐13Rα2‐Fc group, the annulus fibrosus was ordered, the number of breaks decreased, and the type II collagen protein levels increased. In comparison with the model group, we identified 58 differentially expressed genes in the sIL‐13Rα2‐Fc group, and these were involved in 35 signaling pathways. Compared with those in the model group, the mRNA expression levels of Rnux1, Sod2, and Tnfaip6 in the IL‐13Rα2‐Fc group were upregulated, and the mRNA expression levels of Aldh3a1, Galnt3, Fgf1, Celsr1, and Adamts8 were downregulated; these results were verified by real‐time fluorescence quantitative PCR. TIMP‐1 (an ADAMTS inhibitor) and TIMP‐1 combined with the sIL‐13Rα2‐Fc intervention increased the levels of GAG and HA, inhibited the expression of type I collagen, and promoted the expression of type II collagen. Conclusion. Adamts8 may participate in the degradation of ECM components such as GAG and HA and lead to an imbalance in the ECM of the intervertebral disc, resulting in intervertebral disc degeneration. sIL‐13Rα2‐Fc promoted anabolism of the ECM and increased the levels of ECM components by inhibiting the expression of Adamts8, thus maintaining the dynamic equilibrium of the ECM and ultimately delaying intervertebral disc degeneration.
A Theoretical Calculation Method of the Unsupported Span for the Shallow Tunnel in the Soft Stratum
Authors: Tian Xiaoxu , Song Zhanping , Zhou Guannan , Zhang Xiaowei
Published: August 2020

During the construction of the tunnel in soft stratum, it is often found that the unsupported span is too large, resulting in instability of the tunnel face and collapse of the vault. However, the unsupported span was often selected according to the experience of engineers in the actual construction process, which was lack of the theoretical basis. Therefore, based on the calculation model of the surrounding rock pressure of shallow buried tunnel, this paper analyzed the stability of the tunnel face and the vault and then obtained the calculation formula of the unsupported span of the shallow buried tunnel in soft rock stratum. It was pointed out that the unsupported span is not determined by the arch crown stability or the tunnel face stability alone, but by both. The rationality of the formula was verified by a centrifugal test and an engineering case. The analysis and discussion showed that the unsupported span is sensitive to the cohesion and internal friction angle of the rock‐soil mass, especially the cohesion. The unsupported span of the shallow buried tunnel in the soft rock stratum is a linear function of the support pressure. The support pressure has a more significant contribution to the increase of the unsupported span by the centre cross diaphragm (CRD) method, and the unsupported span increases linearly with the increase of the support pressure. The research results provide a theoretical reference for the determination of the unsupported span for the shallow tunnel in the soft stratum.
MicroRNA-451 as an Early Predictor of Chronic Kidney Disease in Diabetic Nephropathy
Authors: Abdelsalam Mostafa , Wahab A. M. , El Sayed Zaki Maysaa , Motawea Mohamad
Published: August 2020

Background. Diabetes mellitus is the leading cause of end-stage renal disease worldwide. Microalbuminuria is the cornerstone for the diagnosis of diabetic nephropathy. However, it is an inadequate marker for early diagnosis. MicroRNAs are not only new and promising markers for early diagnosis but also, but they may also play a role in the prevention of disease progression. Methods. This study included ninety patients with type 2 DM in addition to 30 control subjects. MicroRNA-451 expression in blood and plasma using real-time PCR was evaluated in addition to the classic diabetic nephropathy markers (serum creatinine, urinary albumin, and eGFR). Results. There was a significant difference between the studied groups versus control regarding serum creatinine, eGFR, urinary, and plasma microRNA-451 with p=0.0001. Patients with eGFR 60 ml/min/1.73 m2 showed a significantly higher plasma microRNA-451 (29.6 ± 1.6) and significantly lower urinary microRNA-451 (21 ± 0.9) in comparison to patients with eGFR >60 ml/min/1.73 m2 and p=0.0001. eGFR showed a positive correlation with urinary microRNA-451 and negative correlation with both plasma microRNA-451 and urinary albumin. Both plasma and urinary microRNA-451 are highly sensitive and specific markers for chronicity in diabetic nephropathy patients with sensitivity of 90.9% and 95.5% and specificity of 67.6% and 95.6%, respectively. Conclusion. MicroRNA-451 is a promising early biomarker for chronic kidney disease in diabetic nephropathy with high sensitivity and specificity.
Scalp Necrosis Revealing Severe Giant-Cell Arteritis
Authors: Idoudi Safa , Ben Kahla Marouene , Mselmi Fares , Sriha Badreddine , Guiga A. , Ayachi Samia , Belajouza Colandane , Denguezli Mohamed
Published: August 2020

Giant-cell arteritis (GCA), also referred to as temporal arteritis, is the most common primary vasculitis of the elderly involving the extracranial branches of the carotid arteries, in particular, the temporal artery. Patients usually present with temporal headaches, visual impairment, fever, and scalp tenderness. Scalp necrosis associated with GCA is a rare occurrence with approximately 100 cases reported in the literature to date. It is a therapeutic emergency requiring urgent management as it may lead to irreversible loss of vision. To increase awareness of this severe complication, we report a patient with a scalp necrosis revealing a GCA.
T-Cell Large Granular Lymphocytic Leukemia with Extremely Rare Immunophenotype (CD4/CD8 Double-Positive) Followed by Multiple Myeloma Diagnosis
Authors: Soliman Dina , Sallam Sherin , Akiki Susanna , Mudawi Deena , Ibrahim Feryal
Published: August 2020

T-cell large granular lymphocytic leukemia is characterized by clonal expansion of a CD3+/CD57+ subpopulation, which are typically CD8+ positive cytotoxic T- cells, and can only be diagnosed if there is a persistent, greater than 6 months, elevation of LGL in the blood (usually 2–20 × 109/L), in the absence of an identifiable cause. T-LGLL has been associated with reactive conditions such as autoimmune diseases and viral infections and has also been reported in association with hematologic and non-hematologic malignancies. We report a case of asymptomatic CD4/CD8 double-positive T-LGLL. Flow cytometry on peripheral blood revealed a subpopulation of CD4/CD8 double-positive T cells expressing CD57 and cTIA. Clonality was established by flow cytometric analysis of T-cell receptor V(â) region repertoire which showed that >70% of the cells failed to express any of the tested V(â) regions. Clonality was further confirmed by PCR with the detection of clonal TCR beta and TCR gamma gene rearrangements. Six months later, she presented with persistent lower back pain and diagnosed with IgG kappa multiple myeloma. CD4/CD8 double-positive T-large granular leukemia is the first case reported in the literature. This rare phenotype is either underreported or a truly rare clinical entity. More studies are warranted to characterize the pathogenesis and clinical characteristics of this group of patients and to further assess the relationship between multiple myeloma and T-LGLL as a cause-and-effect relationship or simply related to the time at which diagnosis has been made.
Central Serous Chorioretinopathy: Multimodal Imaging and Management Options
Authors: Iyer Prashanth G. , Schwartz Stephen G. , Russell Jonathan F. , Flynn Harry W.
Published: August 2020

Central serous chorioretinopathy (CSCR) is an idiopathic maculopathy characterized by thickened choroid, retinal pigment epithelial detachment, and variable subretinal fluid. CSCR predominantly affects young men, with risk factors including corticosteroid use, the type A behavior pattern, and psychological stress. While usually self-limited with a good visual prognosis, recurrent and persistent CSCR can lead to outer retinal and/or retinal pigment epithelial atrophy, choroidal neovascularization, and visual loss. This article reviews current multimodal imaging and treatment options, which include observation, mineralocorticoid receptor antagonists, thermal laser photocoagulation, and off-label photodynamic therapy with verteporfin.