bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of hub genes related to prognosis in glioma
Authors: Zhang Delong , Zhao Jinxia , Han Chengzheng , Liu Xiaocen , Liu Jun , Yang Hui
Published: May 2020

Glioma, a common malignant tumor of the central nervous system, has high invasiveness. The objective of the present study was to identify genes playing an important role in the development of glioma and to reveal their potential research value. Conjoint analysis on the GSE16011 dataset in the Gene Expression Omnibus (GEO) database and the ‘Messenger RNA Expression Microarray of Diffuse Gliomas and Controls’ dataset and ‘RNA sequencing of Diffuse Gliomas’ dataset in the Chinese Glioma Genome Atlas (CGGA) database is carried out in the study. The weighted correlation network analysis (WGCNA) was used to carry out co-expression analysis on the GSE16011.

Finally, 24 genes significantly related to grade and prognosis were obtained. In addition, there is no report about CACNG2, JPH3, TUBB6 (tubulin β 6 class V), NRSN1, FAM19A2, NALCN, CDH18, GNAL on glioma.
Dexmedetomidine postconditioning suppresses myocardial ischemia/reperfusion injury by activating the SIRT1/mTOR axis
Authors: Zhang Xiong , Li Yongxing , Wang Yong , Zhuang Yuerong , Ren Xiaojie , Yang Kai , Ma Wuhua , Zhong Ming
Published: May 2020

Myocardial ischemia/reperfusion (MI/R) triggers a complicated chain of inflammatory reactions. Dexmedetomidine (Dex) has been reported to be important in myocardial disorders. We evaluated the role of Dex in MI/R injury via the silent information regulator factor 2-related enzyme 1 (SIRT1)/mammalian target of rapamycin (mTOR) signaling pathway. First, Dex was immediately injected into rat models of MI/R injury during reperfusion. After Evans Blue-triphenyl tetrazolium chloride (TTC) and Hematoxylin–Eosin (H-E) staining, MI/R injury was observed. The extracted serum and myocardial tissues were used to detect oxidative stress and the inflammatory response. Western blot analysis was performed to evaluate MI/R autophagy and the levels of proteins associated with the SIRT1/mTOR axis. The effects of the combination of Dex and SIRT1 inhibitor EX527 on MI/R injury and autophagy were evaluated. Finally, the mechanism of Dex was tested, and autophagy levels and the levels of proteins associated with the SIRT1/mTOR signaling pathway were assessed in MI/R rats. The results of the present study suggested that Dex relieved MI/R injury, reduced cardiomyocyte apoptosis, oxidative stress and inflammatory reactions, up-regulated the SIRT1/mTOR axis and decreased overautophagy in MI/R rats. SIRT1 inhibitor EX527 attenuated the protective effects of Dex. Our study demonstrated that Dex alleviated MI/R injury by activating the SIRT1/mTOR axis. This investigation may offer new insight into the treatment of MI/R injury.
MiR-486-3p inhibits the proliferation, migration and invasion of retinoblastoma cells by targeting ECM1
Authors: Yang Hongwei , Huang Yonggang , He Jian , Chai Guangrui , Di Yu , Wang Aiyuan , Gui Dongmei
Published: May 2020

It has been reported that miR-486-3p expression is decreased in retinoblastoma (RB) tumor tissues, however, its function in RB has been less reported. The present study aimed to explore the regulatory effects of miR-486-3p on RB cells. The expression of miR-486-3p in RB tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, proliferation, apoptosis, migration and invasion ability were determined by cell counting kit-8 (CCK-8) kit, clone formation assay, flow cytometry, scratch assay and transwell, respectively. Targetscan 7.2 and dual-luciferase reporter were used to verify target genes for miR-486-3p. The expressions of apoptosis-related proteins and ECM1 were detected by Western blot. The miR-486-3p expression was decreased in RB tissues and cells. In RB cells, overexpression of miR-486-3p inhibited cell proliferation, migration and invasion, while promoted apoptosis. Moreover, overexpression of miR-486-3p decreased Bcl-2 expression, while increased the expressions of Bax and Cleaved Caspase-3 (C caspase-3). ECM1 was the target gene of miR-486-3p, and miR-486-3p inhibited the expression of ECM1. Furthermore, ECM1 partially reversed the inhibitory effect of miR-486-3p on the proliferation, migration and invasion of RB cells. MiR-486-3p inhibited the proliferation, migration and invasion of RB by down-regulating ECM1.
Centromere assembly and non-random sister chromatid segregation in stem cells
Authors: Carty Ben L. , Dunleavy Elaine M.
Published: May 2020

Asymmetric cell division (ACD) produces daughter cells with separate distinct cell fates and is critical for the development and regulation of multicellular organisms. Epigenetic mechanisms are key players in cell fate determination. Centromeres, epigenetically specified loci defined by the presence of the histone H3-variant, centromere protein A (CENP-A), are essential for chromosome segregation at cell division. ACDs in stem cells and in oocyte meiosis have been proposed to be reliant on centromere integrity for the regulation of the non-random segregation of chromosomes. It has recently been shown that CENP-A is asymmetrically distributed between the centromeres of sister chromatids in male and female Drosophila germline stem cells (GSCs), with more CENP-A on sister chromatids to be segregated to the GSC. This imbalance in centromere strength correlates with the temporal and asymmetric assembly of the mitotic spindle and potentially orientates the cell to allow for biased sister chromatid retention in stem cells. In this essay, we discuss the recent evidence for asymmetric sister centromeres in stem cells. Thereafter, we discuss mechanistic avenues to establish this sister centromere asymmetry and how it ultimately might influence cell fate.
Predicting COVID‐19 trends in Canada: a tale of four models
Authors: Zhang Wandong , Zhao W.G. (Will) , Wu Dana , Yang Yimin
Published: May 2020

This study aims to offer multiple‐model informed predictions of COVID‐19 in Canada, specifically through the use of deep learning strategy and mathematical prediction models including long‐short term memory network, logistic regression model, Gaussian model, and susceptible‐infected‐removed model. Using the published data as of the 10th of April 2020, the authors forecast that the daily increased number of infective cases in Canada has not reached the peak turning point and will continue to increase. Therefore, Canada's healthcare services need to be ready for the magnitude of this pandemic.
Hollow top‐hat DOE shaping method applied in space uplink chaotic optical communication for BER improvement
Authors: Li Mi , Chen Yuan , Yu Jianjie , Chen Minwei , Song Yuejiang
Published: May 2020

As the traditional refractive optical telescope blocks part of the transmission beam, the transmission efficiency in space chaotic optical communication is needed to be improved. A couple of diffractive optical elements (DOEs) are introduced into the optical subsystem at transmitting terminal to avoid the obscuration through shaping transmission beam into hollow top‐hat beam (HTB). The simulation results indicate that shaping transmission beam into HTB is more efficient than traditional hollow Gaussian beam in bit error rate (BER) improvement of space chaotic optical communication. The results are significant for the optimisation design of space uplink chaotic optical communication system.
Receiver design for CDMA‐FBMC/ OQAM systems
Authors: Patra R. , Mahapatro A. , Sahu A.K.
Published: May 2020

This Letter documents BER performance analysis of orthogonal affine precoder (OAP)‐based CDMA filter bank multi‐carrier offset QAM (CDMA‐FBMC/OQAM) systems. The use of OAP cancels the interference introduced by simultaneous transmission of data and training sequence during channel estimation and data detection. This makes the channel estimation and data detection more accurate and hence, BER performance is improved. BER is calculated for different power coefficients of the superimposed training sequence and is compared with that of other FBMC systems. It is observed that the proposed system outperforms the state‐of‐art FBMC systems from BER perspective.
Powering strategies for implanted multi‐function neuroprostheses for spinal cord injury
Authors: Kilgore Kevin L. , Smith Brian , Campean Alex , Hart Ronald L. , Lambrecht Joris M. , Buckett James R. , Peckham Paul Hunter
Published: May 2020

Implantable motor neuroprosthetic systems can restore function to individuals with significant disabilities, such as spinal cord injury, stroke, cerebral palsy, and multiple sclerosis. Neuroprostheses provide restored functionality by electrically activating paralysed muscles in coordinated patterns that replicate (enable) controlled movement that was lost through injury or disease. It is important to consider the general topology of the implanted system itself. The authors demonstrate that the wired multipoint implant technology is practical and feasible as a basis for the development of implanted multi‐function neuroprosthetic systems. The advantages of a centralised power supply are significant. Heating due to recharge can be mitigated by using an actively cooled external recharge coil. Using this approach, the time required to perform a full recharge was significantly reduced. This approach has been demonstrated as a practical option for regular clinical use of implanted neuroprostheses.
Parallel mode notch filters for vibration control of magnetically suspended flywheel in the full speed range
Authors: Peng Cong , He Jiaxi , Deng Zhiquan , Liu Qiang
Published: May 2020

Undesired vibration force caused by harmonic currents is a common problem in a magnetically suspended flywheel (MSFW) rotor system. It poses a potential threat to system stability and performance degradation. In this work, multiple different phase‐shift notch filters are connected in parallel mode to suppress the vibration harmonics. First, the multi‐frequency vibrations in the MSFW is modelled and analysed. Then multiple different notch filters in parallel mode are proposed to plug into the baseline magnetically suspension system. The performance comparison with the conventional multiple notch filters is investigated. The parameters design and calculation for the proposed method are analysed in details. Moreover, the closed‐loop stability of the overall system is given in the full speed range. Finally, simulation and experimental results for the MSFW demonstrate the superiority of the proposed method on both harmonics suppression and stability preservation.
Intelligent second‐order sliding mode control for permanent magnet linear synchronous motor servo systems with robust compensator
Authors: Zhao Ximei , Wang Tianhe , Jin Hongyan
Published: May 2020

In this study, an intelligent second‐order sliding mode control (SMC) method combining second‐order SMC (SOSMC) and recurrent radial basis function neural network (RRBFNN) applicable to the permanent magnet linear synchronous motor (PMLSM) is proposed to achieve high‐performance servo control fields. On the basis of a dynamic model of PMLSM and the SMC theory, the chattering problem in SMC is weakened and the tracking accuracy is improved by the design of SOSMC. As for the boundary of the uncertainty factors is difficult to obtain, the optimal performance of SOSMC is hard to achieve, the RRBFNN uncertainty observer is introduced for estimating the value of the uncertainty factors. Owing to the strong learning ability, the network parameters can be trained online. Besides, a robust compensator is developed to suppress the uncertainties such as approximation error, optimal parameter vector and higher Taylor series for further improving the robustness. Moreover, the adaptive learning algorithms are obtained by using the Lyapunov theorem to guarantee the asymptotical stability of the system. The experiments demonstrate that the proposed scheme provides high performance dynamic characteristics and strong robustness to uncertainties.
EDF‐LPR: a new encoder–decoder framework for license plate recognition
Authors: Gao Fei , Cai Yichao , Ge Yisu , Lu Shufang
Published: May 2020

Although automatic license plate recognition (ALPR) has been studied for decades, the final recognition result can be accurate only if the license plate is detected and the standard format is unambiguous. However, since an image may contain license plates with different formats and scales, license plate detection and standard format classification may fail. In this study, a new ALPR codec framework named EDF‐LPR is presented. As for the encoder, at the first stage, candidate license plate characters are detected and recognised directly without considering the format of license plate, and candidate regions of characters are extracted by density‐based spatial clustering of applications with noise‐like algorithm; at the second stage, poor regions are processed by tilt correction and scale normalisation to obtain more accurate candidate characters. As for the decoder, a sequence learning model is trained to convert each unordered coded sequence into a sequence composed of marks that indicate a way to construct the final result string. Experiments are designed to evaluate the performance of EDF‐LPR on both detection rate and recognition rate. The experimental results on public datasets show that the detection rate and recognition rate are 99.51 and 95.3%, respectively, at about 40 fps.
Energy‐efficient workload allocation in fog‐cloud based services of intelligent transportation systems using a learning classifier system
Authors: Abbasi Mahdi , Yaghoobikia Mina , Rafiee Milad , Jolfaei Alireza , Khosravi Mohammad R.
Published: May 2020

Nowadays, renewable energies have been considered as one of the important sources of energy supply in delay‐sensitive fog computations in intelligent transportation systems due to their cheapness and availability. This study addresses the challenges of using renewable power supplies in delay‐sensitive fogs and proposes an efficient workload allocation method based on a learning classifier system. The system dynamically learns the workload allocation policies between the cloud and the fog servers and then converges on the optimal allocation that fulfils the energy and delay requirements in the overall transportation system. Simulation results confirm that the proposed algorithm reduces the long‐term costs of the system including service delay and operating costs. Also, compared to some other techniques, when the proposed method presents the most successful solution for reducing the average delay of the workloads and converging on the minimum value as well as retaining or even increasing the battery levels of fog nodes up to 100%. The lowest cost of the delay is 5 among other available methods, whereas in the proposed method, this value approaches 4.5.
Development of an adaptive control strategy for the three‐phase grid side converter with wide range of parametric and load uncertainties
Authors: Mondal Prosenjit , Tripathy Praveen , Adda Ravindranath , Saha Ujjwal K.
Published: May 2020

A new approach is proposed here to control the two‐level three‐phase grid side converter. The proposed control strategy is an extended state observer (ESO)‐based adaptive control, consists of two cascaded control loops. The adaptive‐multi‐input multi‐output controller is employed in the inner control loop, which is used to regulate the active and reactive component of the grid currents. The outer‐loop consists of an adaptive controller augmented with an ESO to regulate the DC bus voltage. The goal of the proposed control strategy is to maintain a unity power factor while keeping the DC bus voltage constant under a sudden change in load demand at DC side, i.e. change in the resistive load connected across the DC bus. The proposed adaptive controller in the inner control loop does not require any information about the parameters associated with the grid filter (L‐filter), and hence, it is found to be more robust towards parametric variations. The ESO‐based adaptive controller is compared with the classical proportional–integral control in real‐time, and the comparison indicates that the proposed controller not only accomplishes a nearly flawless tracking performance but also delivers a complete robust performance against resistive load variation across the DC bus.
Step‐Up seven‐level neutral‐point‐clamped inverter based topology for TL‐PVS
Authors: Martinez‐Garcia Juan F. , Vazquez‐Guzman Gerardo , Martinez‐Rodriguez Panfilo Raymundo , Escobar Gerardo , Valdez‐Fernandez Andres A. , Sosa‐Zuniga Jose M.
Published: May 2020

Single‐phase transformerless inverters are widely installed in grid connected photovoltaic systems due to their outstanding advantages, namely, high efficiency, low cost and high power density. The lack of galvanic isolation leads to common‐mode voltage (or current) issues, which are solved by means of modifications to topologies, control schemes and modulation strategies. This study proposes a novel multilevel inverter for single‐phase transformerless photovoltaic systems. The topology is based on the neutral‐point‐clamped inverter, and is aimed to attenuate the leakage ground current. The latter is caused by the common‐mode voltage fluctuations affecting the stray capacitances formed between the photovoltaic cells and the grounded frame. On the one hand, the proposed multilevel inverter can synthesise a seven levels output voltage, which reduces the total harmonic distortion. On the other hand, the magnitude of the output voltage can reach up to 1.5 times the DC input voltage, which eliminates the need of a voltage‐boosting stage for grid interconnection. This study also presents three dedicated pulse‐width modulation strategies, all of them based on the level‐shifted multicarrier sinusoidal pulse‐width modulation scheme. Numerical simulations and experimental tests in a 1 kW setup have been performed to evaluate the performance of the proposed topology
Real‐time open‐switch fault diagnosis in automotive permanent magnet synchronous motor drives based on Kalman filter
Authors: Naseri Farshid , Schaltz Erik , Lu Kaiyuan , Farjah Ebrahim
Published: May 2020

This study proposes an effective diagnosis method for single and multiple open‐switch faults (OSFs) in three‐phase permanent magnet synchronous motor (PMSM) drives. The proposed method is based on the real‐time estimation of the three‐phase motor currents using three Kalman filters (KFs). Three residual signals are defined as the differences between the three‐phase measured and estimated stator currents. The averaged normalised residual signals are used as diagnostic criteria for the detection of OSFs. The proposed method accurately detects the OSFs, localises the faulty switches and effectively discriminates between the OSFs and current sensor faults. The main superiorities of the proposed KF‐based method are its fast detection time and high robustness to measurement noises/errors and load variations. Moreover, the proposed method is useful for both closed‐loop and open‐loop PMSM drives. The proposed method can be embedded as a subroutine in the drive control unit without any hardware extension. The effectiveness of the proposed method is confirmed through extensive simulations and several hardware‐in‐the‐loop experiments on a testbed with a 1.5 kW PMSM and dSPACE1104 control board. In addition, the real‐time feasibility of the proposed method using low‐cost microprocessor technology is guaranteed by testing it on TMS320F28335 from Texas Instruments©.
Active DC‐link balancing and voltage regulation using a three‐level converter for split‐link four‐wire system
Authors: Manandhar Ujjal , Zhang Xinan , Gooi Hoay Beng , Wang Benfei , Fan Feng
Published: May 2020

The integration of the distributed generation to the unbalanced loads or the grid requires a three‐phase four‐wire inverter. The three‐phase four‐wire inverter could be of three‐leg or four‐leg topology. However, both the topologies have their drawbacks. The three‐leg inverter topology with a split capacitor suffers from poor DC link voltage regulation and poor DC link voltage utilisation. The four‐leg inverter topology suffers from poor electromagnetic compatibility. To solve these problems, the split link inverters with active balancing capabilities are studied by many researchers. The split link inverter with an active balancing inverter requires a constant DC link voltage and has less flexibility regarding the variation of the DC link voltage. In this study, a new converter topology is proposed, which provides the controllable DC link voltage to split link inverter with active balancing capability and also reduces the voltage stress to semiconductor switches to half DC link voltage. The detailed description of the proposed converter topology, design of the controller, and control hardware‐in‐the‐loop verification are presented in this study.
Non‐linear bifurcation method to determine the boost converter switching frequency
Authors: Tsirbas Elias D. , Topalis Frangiskos V. , Skoubris Evangelos N.
Published: May 2020

Prior to the design of the feedback system for a boost converter, a suitable switching frequency for the transistor has to be determined. A non‐linear method for determining this frequency via an experimental open‐loop converter model is studied. Utilising the open‐loop model as an investigative tool, two non‐linear distinct resonant frequencies have been found to be a source of chaos. This condition for chaos holds when the boost diode's reverse‐recovery time, its non‐linear capacitance, as well as the inductance are the combined parameters within these frequencies. When the switching frequency is synchronised with these frequencies, ultra‐harmonics, period‐doublings and sudden transitions to chaos occur for various switching frequency ranges. The dependence equations of our theoretical model that incorporate these resonant frequencies predict the unstable frequency regions. The authors’ numerical method utilises a bifurcation peak‐to‐peak analysis that detects the waveform periodicity of certain voltage variables. Highly unstable behaviour of the converter is reported both in simulation and in the laboratory. The periodic and non‐periodic regions are confirmed by the corresponding computations of the Lyapunov exponent, Poincaré sections, frequency spectra and bifurcation diagrams.
Preparation of poly(o‐phenylenediamine) nanoparticles with hydrolysed PEO45‐b‐PtBA35 as template and its electrochemical properties
Authors: Lan Haidie , Muslim Arzugul , Wang Lin
Published: May 2020

Amphiphilic block copolymer poly(ethylene oxide)‐b‐poly(tert‐butyl acrylate) (PEO45‐b‐PtBA35) from atom transfer radical polymerisation was hydrolysed to varying degrees through adjusting hydrolysis time. And the hydrolysis product poly(ethylene oxide)‐b‐poly(acrylic acid) (PEO45‐b‐PAA35) was obtained and used as a template to synthesise nanostructured poly(o‐phenylenediamine) (PoPD). The influence of hydrolysis degrees of PEO45‐b‐PAA35 on the size and electrochemical properties of PoPD was investigated. Results showed that the PoPD particles have uniform sizes, and their size could be tuned with the hydrolysis degree of PEO45‐b‐PAA35. The average diameter and length of PoPD were less than 86 and 135 nm, and the size of these particles was increased with the increase of hydrolysis degree of PEO45‐b‐PAA35. Electrochemical characterisation proves that the particle with a smaller size had a better electrochemical activity. When the hydrolysis time was 12 h, the PoPD had the best specific capacitance compared with other samples. The discharge specific capacitance calculated by chronopotentiometric test of this sample is reached 809 F·g−1 at the current density of 0.5 A·g−1.
Effect of nitrogen or boron impurities on the mechanical and vibrational properties of graphene nanosheets: a molecular dynamics approach
Authors: Mehrabani Mahboube , Khatibi Mohammad Mahdi , Ashory Mohammad Reza , Sadeghzadeh Sadegh
Published: May 2020

Investigation of mechanical and vibrational properties of nano‐structures using the analytical methods would be time‐consuming. Therefore, using a semi‐empirical method would reduce the time needed to investigate materials characterisation. One of the semi‐empirical approaches is molecular dynamics. In this Letter, the large‐scale atomic/molecular massively parallel simulator software is used to simulate the mechanical and vibrational behaviour of a nitrogen‐ and boron‐doped 24.04 × 51.13 Å graphene nano‐sheet. The natural frequencies, Young's modulus, and ultimate tensile strength (UTS) are studied. By adding impurity to the nanosheet and increasing its density, Young's modulus, UTS, and natural frequencies were decreased. The decrease in tensile properties was more significant in the case of boron impurity. When the boron (nitrogen) impurity increased to about 20%, Young's modulus and the first natural frequency were decreased 7.1% (9%) and 16.8% (73%), respectively. This illustrates that Young's modulus and natural frequencies are directly related. Therefore, for the same dimensions and boundary conditions, it is obvious that the increase in impurity content has reduced the natural frequencies of the nanostructure.
Reconstruction of water ice: the neglected process OH + OH → H2O + O
Authors: Redondo P. , Pauzat F. , Ellinger Y. , Markovits A.
Published: May 2020

Context. Although H2O is the most important molecular material found in the solid state in the interstellar medium, the chemical routes leading to ice through surface reactions are still a matter of discussion. Three reaction pathways proposed in the past are at the heart of current research: hydrogenation of atomic oxygen, molecular oxygen, and ozone. The reaction network finally leads to a small number of processes giving H2O: H + OH, H2 + OH, and H + H2O2. To these processes, OH + OH should be added. It is known to be efficient in atmospheric chemistry and takes the irradiations of the interstellar grains into account that, directly or indirectly, create a number of OH radicals on and in the icy mantles.

Aims. We study the role of the existing ice in its own reconstruction after it is destroyed by the constant irradiation of interstellar grains and focus on the OH + OH reaction in the triplet state.

Methods. We used numerical simulations with a high level of coupled cluster ab initio calculations for small water aggregates and methods relevant to density functional theory for extended systems, including a periodic description in the case of solid water of infinite dimensions.

Results. OH + OH → H2O + O reaction profiles are reported that take the involvement of an increasing number of H2O support molecules into account. It is found that the top of the barrier opposing the reaction gradually decreases with the number of supporting H2O and falls below the level of the reactants for H2O layers or solid water.

Conclusions. In contrast to the gas phase, the reaction is barrierless on water ice. By adding a reconstructed H2O molecule and a free oxygen atom at the surface of the remaining ice, this reaction leaves open the possibility of the ice reconstruction.
The effects of a background potential in star cluster evolution
Authors: Reinoso B. , Schleicher D. R. G. , Fellhauer M. , Leigh N. W. C. , Klessen R. S.
Published: May 2020

Runaway stellar collisions in dense star clusters are invoked to explain the presence of very massive stars or blue stragglers in the center of those systems. This process has also been explored for the first star clusters in the Universe and shown to yield stars that may collapse at some points into an intermediate mass black hole. Although the early evolution of star clusters requires the explicit modeling of the gas out of which the stars form, these calculations would be extremely time-consuming and often the effects of the gas can be accurately treated by including a background potential to account for the extra gravitational force. We apply this approximation to model the early evolution of the first dense star clusters formed in the Universe by performingN-body simulations, our goal is to understand how the additional gravitational force affects the growth of a very massive star through stellar mergers in the central parts of the star cluster. Our results show that the background potential increases the velocities of the stars, causing an overall delay in the evolution of the clusters and in the runaway growth of a massive star at the center. The population of binary stars is lower due to the increased kinetic energy of the stars, initially reducing the number of stellar collisions, and we show that relaxation processes are also affected. Despite these effects, the external potential enhances the mass of the merger product by a factor ∼2 if the collisions are maintained for long times.
Mathematical modelling for coronavirus disease (COVID-19) in predicting future behaviours and sensitivity analysis
Authors: Khoshnaw Sarbaz H. A. , Salih Rizgar H. , Sulaimany Sadegh
Published: May 2020

Nowadays, there are a variety of descriptive studies of available clinical data for coronavirus disease (COVID-19). Mathematical modelling and computational simulations are effective tools that help global efforts to estimate key transmission parameters. The model equations often require computational tools and dynamical analysis that play an important role in controlling the disease. This work reviews some models for coronavirus first, that can address important questions about the global health care and suggest important notes. Then, we model the disease as a system of differential equations. We develop previous models for the coronavirus, some key computational simulations and sensitivity analysis are added. Accordingly, the local sensitivities for each model state with respect to the model parameters are computed using three different techniques: non-normalizations, half normalizations and full normalizations. Results based on sensitivity analysis show that almost all model parameters may have role on spreading this virus among susceptible, exposed and quarantined susceptible people. More specifically, communicate rate person–to–person, quarantined exposed rate and transition rate of exposed individuals have an effective role in spreading this disease. One possible solution suggests that healthcare programs should pay more attention to intervention strategies, and people need to self-quarantine that can effectively reduce the disease.
Auf der anderen Seite – Erfahrungen mit einem Frühgeborenen
Authors: Meinen Sabrina , Krüger Edeltraud
Published: May 2020

Sabrina Meinen ist Ergotherapeutin und hat lange auf einer Stroke Unit gearbeitet. Unerwartet steht sie eines Tages auf der anderen Seite: Ihr Sohn kommt zehn Wochen zu früh zur Welt. Gemeinsam mit der behandelnden Physiotherapeutin berichtet sie von der intensiven Zeit. Ein Erfahrungsbericht.
Biochanin A, the Most Potent of 16 Isoflavones, Induces Relaxation of the Coronary Artery Through the Calcium Channel and cGMP-dependent Pathway
Authors: Migkos Thomas , Pourová Jana , Vopršalová Marie , Auger Cyril , Schini-Kerth Valérie , Mladěnka Přemysl
Published: May 2020

The dietary intake of flavonoids seems to be inversely related to cardiovascular mortality. The consumption of isoflavonoids is increasing in the general population, especially due to the use of food supplements and a variety of isoflavonoid-rich foods. However, detailed studies on the vascular influence of individual pure isoflavonoids are mostly missing. For this study, 16 isoflavonoids were initially screened for their vasorelaxant properties on rat aortas. The 2 most potent of them, biochanin A and glycitein, were further tested for the mechanism of action on porcine coronary arteries. They both induced an endothelium independent vascular relaxation, with EC50 below 6 and 17 µM, respectively. Biochanin A, but not glycitein, was able to block the vasoconstriction caused by KCl, CaCl2, serotonin, and U46619 in a dose-dependent manner. Another series of experiments suggested that the major mechanism of action of biochanin A was the inhibition of L-type calcium channels. Moreover, biochanin A in relatively small concentrations (2 – 4 µM) interfered with the cGMP, but not cAMP, pathway in isolated coronary arteries. These results indicate that some isoflavonoids, in particular biochanin A, are able to have vasodilatory effects in micromolar concentrations, which is of potential clinical interest for the management of cardiovascular pathologies.
Fan flaps for Cheiloplasty (lower lip reconstruction): A two year experience
Authors: Rajan T.M. Sheeja , Varughese Saramma , Jagadeesh S.
Published: May 2020

Aim:To evaluate the fan flaps done during the past two years with regard to applicability, reliability, functional perspective and complications.Materials and Methods:All the fan flaps done were reviewed by inspecting case records and directly following up the patients (at periodic intervals). The indications, applicability to defect size, postoperative aesthetic and functional results and drawbacks were noted.Results: Eight fan flaps were done during this period. All were done for squamous cell carcinoma affecting lower lip. All the flaps survived. Two early cases of Gilles fan flap developed significant microstomia. Later flaps with neurovascular preservation maintained sensations with good commissural competence. Nakajima fan flaps gave good overall results.Conclusions: The fan flaps, especially the Nakajima modification with neurovascular preservation are safe and reliable flaps for lip reconstruction in terms of form and function.
Flexor accessorius longus: A rare variationof the deep extrinsic digital flexors of the leg and its phylogenetic significance
Authors: Jaijesh P , Shenoy M , Anuradha L , Chithralekha K K
Published: May 2020

Anomalies of the calf muscles are rare. One such anomalous muscle, known as the Muscle Flexor accessorius longus (also named accessorius ad accessorium, accessorius secondus, accessory flexor digitorum longus or pronator pedis) is of morphological significance. When present, this originates in the deep fascia of the tibia or fibula and inserts in the foot either into the flexor digitorum accessorius or into the tendons of the flexor digitorum longus. In this report we present a discussion of the morphological significance and phylogenetic history of one such muscle observed. In this case report we describe an anomalous calf muscle which extends from the popliteal region, runs along the posterior compartment of the leg, reaches the sole and is inserted to the flexor digitorum longus muscle. This kind of muscle variations are considered to be the higher origin of the flexor digitorum accessorius muscle of the sole. Here we discuss the phylogenetic history of this muscle as this muscle variant is present in some primitive mammals, absent in apes and in this particular case appeared as one of the muscles of the flexor compartment of the leg.
Effect of Limb Position on Measurements of the Quadriceps Muscle Length/Femoral Length Ratio in Normal Beagle Dogs
Authors: Murakami Sawako , Nagahiro Yukari , Shimada Masakazu , Kanno Nobuo , Suzuki Shuji , Yogo Takuya , Harada Yasuji , Hara Yasushi
Published: May 2020

Objectives Dogs with patella alta reportedly have a shorter extensor mechanism than normal dogs. The present study aimed to measure the length of the extensor mechanism and to assess the effect of limb position on the quadriceps muscle length (QML)/femoral bone length (FL) ratio.

Study Design Three-dimensional computed tomography images were taken of 12 Beagle dogs. Each dog underwent computed tomographic imaging 24 times with different limb positions. The QML/FL was measured on each image, along with the hip flexion–extension, hip abduction–adduction and stifle flexion–extension angles. Multiple regression analysis was used to determine the effect of these angles on the QML/FL.

Results The QML/FL was increased with the hip extended (standardized partial regression coefficient 0.855 with linear plotting, 0.829 with log plotting) and with the stifle flexed (standardized partial regression coefficient 0.814 with linear plotting, 0.800 with log plotting). The partial regression coefficient of the hip abduction–adduction angle was small, indicating a small impact on the QML/FL. The 95% confidence range of the QML/FL with the hip extended and stifle flexed was 0.87 to 1.00 (mean ± standard deviation: 0.93 ± 0.03).

Conclusion The QML/FL was more influenced by joint angles when the hip was flexed or the stifle was extended. Hence, these positions should be avoided when evaluating the QML/FL so that the QML is less altered by slight positioning disparities.
Rectal Perforation following High-Pressure Distal Colostogram
Authors: Brisighelli Giulia , Lorentz Liam , Pillay Tanyia , Westgarth-Taylor Christopher J.
Published: May 2020

In patients with anorectal malformations and a colostomy, the high-pressure distal colostogram is the technique of choice to determine the type of malformation and thus to plan the surgical repair. Perforations associated with high-pressure distal colostograms are very rare. The aim of our study was to identify pitfalls to prevent perforation secondary to high-pressure distal colostogram. The study included two male patients and was complicated with rectal perforations secondary to high-pressure distal colostogram. Both patients had an imperforate anus without a fistula. One patient had extraperitoneal rectal perforation with progressive contrast spillage into the peritoneum and demised. The other patient developed an extraperitoneal perforation and an associated necrotizing fasciitis of his perineum and scrotum, but he recovered well after debridement. Two further cases of rectal perforation have been described in the literature. Rectal perforation, although rare, is a described life-threatening complication secondary to high-pressure distal colostogram. The cause is excessive contrast pressure. Injection of contrast should be stopped once the distal end of the colon has a convex shape. Intraperitoneal perforation may cause hypovolemic/septic shock, and patients need to be appropriately resuscitated and should undergo laparotomy. Extraperitoneal perforation requires close monitoring for possible local complications, which may necessitate early debridement.
Idiopathic Intracranial Hypertension: Contemporary Management and Endovascular Techniques
Authors: Case David , Seinfeld Joshua , Roark Christopher , Kumpe David
Published: May 2020

Idiopathic intracranial hypertension (IIH) is a disease process of abnormally increased intracranial pressure in the absence of a mass lesion. Medical management, optic nerve fenestration, and surgical shunting procedures have failed to produce consistently successful results. In an unknown percentage of cases, IIH is caused by dural venous sinus obstruction which can be cured by endovascular treatment with dural venous sinus stent placement. This helps prevent progressive vision loss and worsening papilledema caused by underlying increased intracranial pressure from venous outflow obstruction. Patients are required to have an established diagnosis of IIH, preferably made by a neuroophthalmologist, with clearly documented papilledema or at minimum visual disturbance along with lumbar puncture opening pressure greater than 25 cm H2O. Transverse to sigmoid sinus focal narrowing (intraluminal filling defect or extrinsic compression) must be seen during the venous phase of neuroangiography (NA) along with a pressure gradient of 10 mm Hg or greater across the focal narrowing during dural venous sinus pressure monitoring. A successful reduction is defined as a pressure gradient of less than 10 mm Hg after stent placement. Neuroophthalmologic follow-up occurs within 1 to 2 months to assess for changes in papilledema. If papilledema is unchanged or worsened, NA and hemodynamic evaluation is repeated for consideration of restenting. Appropriate patient selection criteria are required for IIH venous sinus stenting. The utilization of refined endovascular techniques along with postprocedure follow-up protocols can ultimately cure IIH for a select group of patients.
Radial Access for Neurovascular Procedures
Authors: Satti Sudhakar R. , Vance Ansar Z.
Published: May 2020

Radial access is increasingly being considered in neurovascular procedures after becoming the standard access route in percutaneous cardiovascular interventions. Current barriers include a lack of dedicated equipment for radial to neurovascular target vessels, lack of training for physicians and fellows, and physician bias toward femoral access secondary to greater experience and familiarity. Radial access has been proven to be safer and the preferred access route by most patients. These two factors make radial access inevitability when the aforementioned barriers are overcome. The purpose of this brief article is to highlight some important considerations of radial access specific to the neurovasculature.
Vertebral Compression Fractures: Evaluation and Management
Authors: Madassery Sreekumar
Published: May 2020

Painful vertebral body compression fractures are prevalent in elderly patients. Two-thirds of patients will have spontaneous resolution of pain in 4 to 6 weeks and initial management is nonoperative with pain management and bracing. A focused history and exam can identify patients likely to benefit from vertebral body augmentation (e.g., vertebroplasty or kyphoplasty). Patients with persistent back pain and bone marrow edema on magnetic resonance imaging may benefit from injection of cement into the fractured vertebral body with either vertebroplasty or kyphoplasty. Patients most likely to benefit are those with severe pain refractory to nonoperative management who are offered intervention within 3 weeks. The procedure is usually performed as an outpatient with rare complications. Most patients report immediate, durable pain relief.
Gender-Related Differences in Clinical Presentation and Angiographic Findings in Patients with Ischemia and No Obstructive Coronary Artery Disease (INOCA): A Single-Center Observational Registry
Authors: Gitto Mauro , Gentile Francesco , Nowbar Alexandra N. , Chieffo Alaide , Al-Lamee Rasha
Published: May 2020

Ischemia and no obstructive coronary arteries (INOCA) is a common clinical presentation, with a variety of causes that are often not fully investigated in routine clinical practice. The goal of our study was to characterize a real-world population of patients with INOCA, with a deeper focus on symptoms and stress test findings. The study population consisted of 435 patients who underwent diagnostic coronary angiography for anginal symptoms and/or evidence of myocardial ischemia at non-invasive imaging. In all patients angiography demonstrated nonobstructive coronary artery disease (CAD, less than 30% luminal diameter stenosis or fractional flow reserve > 0.8 and/or instantaneous wave-free ratio  > 0.89). Fifty-four percent of the patients were women. Atypical clinical presentation was more common in women (59.5 vs. 49.5%, p = 0.037). Women were more likely to have normal coronary arteries than men (41.8 vs. 16.2%, p < 0.001), and less likely than men to have hemodynamically non-significant CAD (32.1 vs. 55.1%, p < 0.001). No significant correlation between typicality of symptoms and evidence of ischemia was found in those patients (244/435, 56.1%) who had either dobutamine stress echocardiography or electrocardiogram stress test. INOCA is a common clinical condition, prevalent in women often presenting with atypical symptoms.
Perioperative Acute Pulmonary Embolism: A Concise Review with Emphasis on Multidisciplinary Approach
Authors: Porres-Aguilar Mateo , Rivera-Lebron Belinda N. , Anaya-Ayala Javier E. , León María Cristina Guerrero de , Mukherjee Debabrata
Published: May 2020

Perioperative acute pulmonary embolism represents a relatively rare complication; however, it could be very serious and devastating in some cases. Its diagnosis could be particularly challenging, especially in the intraoperative period. Herein, we emphasize some key concepts with the aim to perform an early and appropriate risk stratification, diagnostic and therapeutic approach in a multidisciplinary fashion, a brief overview on thromboprophylaxis, with the main objective to improve outcomes and survival in these challenging patients.
Good Inter- and Intra-Observer Reliability for Assessment of Radiographic Femoral and Tibial Frontal and Sagittal Planes Joints Angles in Normal Cats
Authors: Palumbo Piccionello Angela , Salvaggio Alberto , Volta Antonella , Emiliozzi Fabiola , Botto Riccardo , Dini Fabrizio , Petazzoni Massimo
Published: May 2020

Objective The aim of this study was to evaluate the inter- and intra-observer reliability of plain digital radiographs for assessing normal feline femoral and tibial joint reference angles in the sagittal and frontal planes.

Study Design This was a cadaveric radiographic anatomical study. that involved 20 short-haired domestic adult cats.

Materials and Methods Sagittal and frontal plane tibial and femoral joint angles of 40 limbs were measured twice by three observers with different levels of experience. Inter- and intraobserver reliability was determined by the intra-class correlation coefficient (ICC). An ICC > 0.75 was considered high correlation, 0.74 > ICC > 0.60 good correlation, 0.59 > ICC > 0.4 fair correlation and an ICC < 0.40 poor correlation.

Results Mean ± standard deviation angles were anatomic lateral proximal femoral angle (aLPFA) 110.6 ± 3.6; anatomic lateral distal femoral angle (aLDFA) 91.9 ± 2.1; mechanical lateral proximal femoral angle; mLPFA (mLPFA) 107.3 ± 3.6; mechanical lateral distal femoral angle (mLDFA) 95.5 ± 1.7; femoral neck anteversion (FNA) 121.9 ± 4.1; anatomical caudal proximal femoral angle (aCPFA) 156.1 ± 3.9; anatomical caudal distal femoral angle (aCDFA) 101.4 ± 1.4; mechanical medial proximal tibial angle (mMPTA) 93.5 ± 1.2; mechanical medial distal tibial angle (mMDTA) 100.5 ± 2.3; mechanical cranial proximal tibial angle (mCrPTA) 113.1 ± 3.2; tibial plateau angle (TPA) 23.1 ± 3.2; mechanical cranial proximal tibial angle (mCrDTA) 86.7 ± 3.1.

The intra-observer ICC indicated high correlation for 70% or more of the measurements. The inter-observer agreement among observers was high. These results show that the radiographic method for measuring femoral and tibial joint angles was good or high, except for FNA and mCrDTA.

Conclusions This study provides some radiographic anatomical and mechanical joint angles of the femurs and tibias of normal domestic short-haired cats. We found good reliability for both intra- and interobserver measurements.