bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Rice Husk Ashes Filled Recycled Polyethylene Composites towards Physical, Mechanical Properties and Its Degradation Characteristics
Authors: Nurhayati Chasri , Susanto Tri
Published: October 2020

Plastic waste is dominated by 46% Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE). The plastics waste are persistent pollutants that is not biodegradable waste. Recycled polyethylene (RP) from the plastic waste would potentially be used as polymer composites for pavement or road construction application. In order to improve physical, mechanical and water absorption properties, some fillers need to be added. The agro-industrial waste of rice husk ashes (RHA) containing highly silica SiO2 may be utilized as filler in this composites. The objective of this research is to observe the effect of RHA addition in to the recycled plastic composites towards its physical, mechanical properties and degradation characteristics. The RHA loading was designed weight/weight of RP as follows 0%; 5%; 10%; 15%; 20%, while degradation duration was 0, 30 and 60 days. The recycled ethylene was smelted and mixed with the RHA at temperature 120 o C; and then pressed using 200 kg.cm2 hydraulic press as pavement block (20x10x6 cm dimension). The results showed that the addition of RHA leads to increase the water absorption capacity, whereas it reduces the compressive strength. The RHA filler addition into composites has less significantly effects on thickness and surface-physical appearance (cracking profile). The 60 days degradation at ambient temperature with the sun lighting in a burial soil has a slight effect on the decreasing of compressive strength, thickness, and physical appearance (small crack on the surface) due to the thermal oxidative degradation. In addition, the burial soil exacerbate the bio-degradation mechanism due to the presence of high water absorbed within the RP-RHA composites. To sum up, the RHA may be potentially used as filler to improve water absorption capacity. Anti-oxidant and plasticizer types need to be researched to improve its physical mechanical properties.
Magnetization of Biodiesel (Cooking Oil Waste) to Temperature and Pressure Combustion in Diesel Engine
Authors: Nufus T H , Lestari S , Ulfiana A , Manawan M
Published: October 2020

Research related to the provision of magnetic field strength in the flow of fuel that can cause more complete combustion has been reported by many researchers and most of these observations were carried out by measuring machine performance using a dynamometer. Given the dynamometer prices are very expensive then another way to prove the occurrence of complete combustion is through the combustion chamber indicator. The hypothesis is the greater magnetic field passed by fuel, the more perfect the combustion is. In addition, the combustion chamber temperature also increases and thermal efficiency increases. The fuel used is biodiesel derived from cooking oil waste, biodiesel 100% (denoted as B0), a blend of biodiesel (20%)-diesel (80%) (denoted as B20), a blend of biodiesel (40%)-diesel (60%) (denoted as B40), a blend of biodiesel (30%)-diesel (30%) (denoted as B70), and diesel 100% (denoted as B100). The magnetic field used is 500 Gauss, 900 Gauss and 1500 Gauss. Measurement of combustion temperature is using R type temperature sensor, which is connected to the NI USB interface to computer and LabVIEW for data acquisition. 13 HP capacity of diesel engine was used. The results obtained is 13 % temperature increase in the combustion chamber of the engine and 7 - 12% thermal efficiency increase equipped with a magnet compared to a non-magnetic engine.
RETRACTED: Channel Estimation of MIMO-OFDM through Wavelet Transform to Improve the Spectral Efficiency and Data Transmission Rate
Authors: Yogeeswaran S , Parasuraman S , Manimaran A
Published: October 2020

We define a new wavelet transform that is based on a recently defined family of scaling functions: the fractional B-splines. The interest of this family is that they interpolate between the integer degrees of polynomial B- splines and that they allow a fractional order of approximation. The approximation can determine noise in communication signals and help in signal reconstruction and channel estimation in MIMO receiver system. In free space optical communication links, the turbulent atmospheric channel causes fluctuations in both intensity and phase of the transmitted optical signal which degrades their performance. In order to make free space optical communications commercially viable, there is a need for characterizing the atmospheric effects on the received signal statistics, and possibly correcting for the signal degradation using physical optics principles and advanced real-time signal processing techniques. As part of this work, we have constructed an experimental free space optical link over 100 meters so as to characterize the effects of inner-scale and outer-scale turbulence effects, and used it as the platform for carrying out the above objectives. Through these techniques, we have demonstrated bit error rate (BER) reduction and propose to estimate channel accurately.
Twitter Spammer Identification using URL based Detection
Authors: Hasan Fayez Jbara Yosef , Ali Segu Mohamed Hyder
Published: October 2020

Millions of users worldwide participate in social networking sites. The interactions between users and those social sites, as Facebook and Twitter, have an enormous effect as well as sometimes unwanted impact on daily life. Spammers have become a target platform on the prominent social networking sites to scatter huge amounts of damaging and irrelevant information. Twitter has become one of the best-used platforms of all times also thus permits unreasoning spamming. Fake users send unwanted tweets to users to encourage services or sites that affect not just genuine users, but also disrupt the consumption of resources. The main aim of this study is to identify forged users who harm real users, threaten users’ identity and therefore their safety and privacy. In this paper, suggest to URL based detection plus machine learning techniques has been developed for the detection of malicious users, celebrities as well as malicious users, based on user characteristics. A crawler is developed for Twitter for the purpose of detecting malicious users, celebrities and non-malicious users and celebrities, and data from around 22 K users were collected from public information. For training and testing purposes, data from around 7,500 users were used in machine learning classifications to classify users. On basis of performance metrics like accuracy, recall, F-measurement also accuracy 5 classifiers were used and compared. With a precision of 99.8 percent, Random Forest is above all classifiers.
Analysis and Design of Modular Multilevel Converter (MMC) Based on Full Bridge Switching Modules (FBSM) for Harmonic Elimination using POD PWM Control Method
Authors: Hari Babu Varaparla , Balaji K
Published: October 2020

Modular Multilevel Converter (MMC) in HVDC for transmitting the power in longer distance because of high in transmission efficiency rate and cost-effective compared to AC system in many industries. The control of voltage and power is earlier and superior method is modular multilevel converter for HVDC transmission. The use of MMC has reduced the filter size and low frequency. Staircase, carrier-based PWM, space vector and selective harmonic elimination are the method using in MMC system control. Unbalanced networks are studied, and strategies are introduced such that in these circumstances MMC contributes to improving the grid efficiency. It involves the key applications in the transmission of high voltage direct current (HVDC) along with other applications of Medium Voltage (MV) and Low Voltage (LV). The MMC with POD-PWM is built using the MATLAB / Simulink method and concludes the advantages and improvements of converter modulation to reduce the voltage ripple and increase the voltage levels.
Computational Fracture Mechanics: Evaluation of The Structural Integrity in a Penstock Applying the BS7910 Standard and Finite Element Analysis
Authors: Barrionuevo G O , Guerrero B A , Walczak M
Published: October 2020

The present work aims to determine the structural integrity of penstocks, applying the BS7910 standard and finite element analysis (FEA). For the study of fracture mechanics in thin-walled cylinders that have defects inside, the structural integrity of the element is determined through a failure assessment diagram (FAD) where the fracture failure index (Kr) is graphed versus plastic collapse index (Lr). Based on the locus of the initial point of failure, the safety factor is calculated, and it is defined if the element is fit for service or if corrective action must be taken to continue operating; later, crack growth is analyzed, where the critical point of rupture of the penstock and therefore its useful life is determined. To contrast results, a simulation of fracture mechanics is performed in ANSYS, where the stress intensity factor (KI) is determined using the fracture tool, and the useful life of the element is also calculated through a fatigue analysis. The use of tetrahedral elements is recommended for the overall meshing and a cobweb configuration for meshing at crack-tip. Finally, the results obtained are compared, where the mean average percentage error of 3.24% was obtained, denoting the usefulness of the two methods as well as the simplicity of the Paris’ law.
Free vibration studies on skew sandwich plates by FEM
Authors: Pavan Kumar Dhotre , Srinivasa C V
Published: October 2020

Present study mainly deals with the extraction of fundamental frequencies using simply supported and clamped isotropic and laminated faced skew sandwich plates with the orthotropic core. Available literature values were referred to validate the fundamental frequencies obtained using the finite element method. The effects of aspect ratio, skew angle, a ratio of the length-to total thickness of the sandwich plate, and the ratio of a thickness of the core to a thickness of face sheet on the free vibration of skew sandwich plates were examined. The present method is also used to study the effect of fiber orientation angle and laminate stacking sequence on free vibration of antisymmetric cross-ply laminated skew sandwich plates are also extracted. CQUAD8 type of element gives converged, accurate results than the CQUAD4 element in the present study. The variation of frequencies is directly proportional with the skew angle.
Multiple Object detection using Autonomous UAVs based on YOLOv3 algorithm
Authors: Murugendrappa N , Gayathri KE , Harshitha GM , Gupta Sony
Published: October 2020

Currently, there has been an enormous increase in interest towards autonomous UAVs and applications with respect to autonomous UAVs such as scientific data collection and security monitoring, infrastructure inspection, search and rescue and much more. Recognizing objects visually is a key step in such applications and is very pivotal to build a complete autonomous system. Nevertheless, the chore of detecting an object is very much challenging and is even more difficult when we have low quality images aboard low cost consumer UAVs. More frequently due to the motion of UAVs, images get blurred, noisy and even onboard cameras have low resolution hence object detection becomes more challenging since identifying objects are quite small and these tasks get even more difficult as there is a necessity of real time detection of objects. This paper focuses on all these aspects and brings an outcome for the object detection and identification.
Portable Intensive Care Unit Equipment Using IoT
Authors: Rakesh Kumar S M , Srikanth K V , Kumar Shubham , Vaibhav Kumar , Madan H T
Published: October 2020

Many lives have been affected every day in remote areas mainly because the patients are not timely and properly treated by the healthcare centers, that unfortunately resulting in loss of human lives. In most of the rural hospitals, patients are unable to get the timely response because of lack of human resources and facilities. In some cases, it becomes even difficult for hospitals to frequently check patients’ conditions and update their record on a regular basis. To deal with these sort of real time problems, we have designed a portable healthcare system, which can be easily adopted in the health care centers. The proposed health care system can be used to measure and monitor various health indicators like temperature, ECG, Blood Pressure, heartbeat etc. The measured parameters of the patient will be recorded using ESP32 module and stored in the cloud server. The Doctors can login to the website, view the parameters and can take the necessary action.
Smart Monitor for Enhancing Security in Smart Home Systems
Authors: Janita Bhuvana , Kannan Jagadeesh
Published: October 2020

This Smart Home device like smart TV, Refrigerator, Smart Thermostat, Smart bulbs, Smart garage doors are preferred for hassle free life, better ambience and to automate mundane tasks. Smart Home helps in Mindful resource utilization and also in Wellness assisted living. Though there are many advantages, Smart Home devices are basically embedded devices that comes with firmware and limited memory capacity. These devices cannot have an Antivirus installed for preventing Virus, Malware, Worms and other security hazards. The Internet of Things has no standard protocol for communication. This is a serious security threat for Home Automation systems. Proposed Idea is to introduce an edge device that will monitor and manage all the home devices and alert user in the event of their abnormal activity. The proposed idea would mitigate Man-in the –Middle (MITM) attacks and Denial of service (DOS) attacks.
Inelastic Behavior of En 31 Steel Metallic Surface Subjected to Hard Body
Authors: Darshan C J , Mahendra H S , Hemaraju  , Rashmi S N
Published: October 2020

In machineries of thermal power plants elements such as coal conveying systems, grinding balls, slurry carrying systems involves transfer of load and displacements. In all these machineries every element is subjected to the hard body such as particles from coal and slurry cause continuous wear results with abrasive wear. Due to this abrasive wear there is inelastic and damage of both the objects was takes place. Since many elements of all these machineries were made from En category steels this study was focused on En 31 steel. In the present study rubber wheel abrader was used to conduct the experiments. 106 microns, 212 microns and 425 microns graded abrader was used for conducting the test. En category steel i.e. En 31 was used as target material for the studies. The sand flow rate of 95 grams/minute was maintained. The weight loss was calculated and found that 0.004, 0.012 and 0.021, for an abrader size of 106 microns following with 0.005, 0.012 and 0.020 & 0.007, 0.022 and 0.023 for an abrader size 425 microns. For all these three tests a normal load of 11.37 N, 35.31 N, and 58.85 N was applied. Scanning electron microscope (SEM) was used to study the morphological analysis. There is light influence on volume loss due to the influence of abrader. Weight loss of the material does not solely depend on increasing in abrader size. Inelastic deformation and wear modes are seen as subject to mechanical properties of the target material. Disfigurement highlights describe the volume loss of the wear.
Protective Coatings for Bio-Composites – A Review
Authors: Srinivasa C V , Ani Allamaprabhu S , Jyothi Prasad B M
Published: October 2020

Even though Bio-based composites are eco-friendly, they are susceptible to degradation owing to both mechanical as well as biological factors. While it is evident that moisture affects the composites considerably, there are other factors such as heat and abrasion that could further accelerate the degradation. This article aims to encapsulate a few techniques for protection of the natural fibre-based composites. The reasons of thermal degradation and efforts to minimize the combustibility of substrates by application of aqueous, organic as well as intumescent coatings along with chemical treatments is discussed in brief. An account on the methods of applying a barrier coat and its subsequent curing is given. The need of gel coats, their advantages and several treatments to enhance the fibres to combat against degradation are outlined.
CFD Simulation of Producer Gas Fuelled SI Engine
Authors: Kumar Amit , Rajakumar D G , Mownesh G K , Basavarajappa
Published: October 2020

Syngas generated from the thermochemical conversion of biomass in a gasifier is increasingly being used for fuelling internal combustion engines, especially for distributed power generation. Producer gas as a fuel has thermo physical properties significantly different from those of conventional fuels. As of date, there are no dedicated engines for alternative fuels in general and producer gas in particular. A review of the available literature indicates experimental experience with producer gas but very little information on modelling and simulation studies are available. While experimental investigations provide actual performance parameters, the information is essentially spatial or temporal average only. Apart from that, fluid dynamic and combustion progress parameters cannot be acquired inexpensively. The current work primarily addresses the combustion progression parameters in a typical spark ignited engine under naturally aspirated and turbocharged after cooled configuration at varying mixture quality using the ANSYS FLUENT computational fluid dynamics software. The CHEMKIN software is used for determining the laminar flame speed for producer gas as a function of the mixture quality. Spatially averaged pressure traces from the simulation are compared with literature pressure traces at the desired condition and various simulation parameters are tuned till a match between the literature and simulation pressure is obtained. Once the simulation is validated, the progress of combustion parameters is derived from the simulation in post processing.
Adaptive Noise Cancellation Using Kalman Filter for Non-Stationary Signals
Authors: Murugendrappa N , Ananth A G , Mohanesh K M
Published: October 2020

The present paper states with the Adaptive Noise Cancellation (ANC) of speech signal corrupted with additive Gaussian white noise. A new method is proposed based on adaptive Kalman filtering. The probabilistic approach of kalman filters over a packet-delaying network given the postpone distribution and decide the minimum required buffer length and algorithm has been used for estimation of unknown state variables within the system. Any work has been achieved for structures with fractional-order dynamics. The new techniques based totally at the kalman filter proposed within the beyond, function in steps: first the noise variance and the parameters of the signal version is estimated and secondly the speech signal expected. The strategies provided inside the paper gives an exclusive method consequently it does not require estimation of the noise variance. The noise variance estimation is always will become part of the kalman advantage calculation. The results of the application of Kalman filter on a non-stationary acoustic signal indicated that SNR of the ∼ 1.17 dB and MSE`0.032 can be achievable using Kalman filters and Kalman filter can be efficiently used for noise cancellation in place of other adoptive filters.
Exploring the role of surface modifications of TiNi-based alloys in evaluating in vitro cytocompatibility: a comparative study
Authors: Kokorev Oleg , Chekalkin Timofey , Marchenko Ekaterina , Yasenchuk Yuri , Gunther Sergey , Serebrov Vladimir , Chernyshova Alena , Obrosov Aleksei , Uludintceva Elena , Kang Ji-Hoon
Published: October 2020

The aim of this study was the comparative analysis of in vitro bio-testing of solid and porous TiNi samples with modified surfaces (intact, oxidated, and etched). Tests for cytocompatibility, hemolysis, and cytotoxicity (MTT) as well as visualization by confocal and scanning electron microscopy have shown that the chemically modified samples are the most cytocompatible. The intact and etched samples did not induce hemolysis greater than 2%, and thus they comply with the ISO 10993-4:2018 standard for hemolysis by blood-contacting biomaterials. Direct culture of etched samples with MCF-7 cells and human leukocytes showed low cytotoxicity. At the same time, the cytotoxicity of samples oxidated at 500 °C was significantly greater than that of the etched samples. Confocal and electron microscopy also confirmed the abovementioned quantitative data. The cells attached to the etched surface in numbers sufficient for them to be able to grow and proliferate on this substrate in vitro. These findings indicate that solid and porous TiNi alloy with surface modifications achieved by a cost-effective method is biotolerable and promising for clinical use and for tissue engineering.
Effect of laser remelting on microstructure and properties of two Ni-base coatings by supersonic particles deposition
Authors: Bingyuan Han , Shaoyi Bei , Kebing Zhou , Yuxiang Liu , Yan Zhang , Xue Yan , Weixing Hang , Fangfang Cui , Wenwen Xu , Wei Du , Sheng Zhu
Published: October 2020

Remelting treatment of In718 and In625 coatings deposited by supersonic particles were conducted by using laser technology. The microstructure, phase composition, microhardness, wear resistance and corrosion of the coating before and after remelting were studied. The results showed that defects such as voids and cracks of the deposited coating were eliminated by laser remelting treatment, the microstructure of the coating became compact and uniform and the bonding mode changed from mechanical bonding to metallurgical bonding. The deposited coating consisted of γ-Ni solid solution and Fe3Ni2 intermetallic compound phase, remelting to form a new phase Ni3(Al,Ti) and high hard phase carbide (Nb,Mo) C. The average microhardness of the remelted coating was 6.96 GPa, which was 1.72 times than that of the deposited coating. The wear resistance of remelting coating was significantly better than that of deposited coating and substrate, and its wear form was mainly abrasive wear. The corrosion resistance of the coating was significantly improved after remelting treatment.
Ellipsometric and ultrasonic studies of nano titanium dioxide specimens doped with Erbium
Authors: Al-Shomar S M , Barakat Mirham A Y , Abdallah A W
Published: October 2020

Nano Er-doped TiO2 thin films prepared by sol-gel technique at different doping concentrations (5%, 7%, 9%, and 11%). The prepared thin films were studied through ultrasonic and ellipsometric measurements. Mechanical properties are known from the ultrasonic method that investigated the effect of the Er-doped amount on the cross-link density, bond strength, elastic properties, and stress-strain relation between atoms of TiO2 thin films. Ellipsometric measurements studied the variation of optical transmittance, energy band gap, refractive index, Urbach energy roughness, and porosity with changing Er-doped amount. Finally, contact angle measurements are done to ensure the self-cleaning property of the prepared thin films. Results deduced that Er-doped enhanced greatly TiO2 thin films, to be used in many industrial applications as self-cleaning glass fabrication.
A new modifier for microstructure and mechanical properties of 6063 aluminum alloy
Authors: Ding Wanwu , Liu Xiaoxiong , Zhao Xiaoyan , Chen Taili , Zhang Haixia , Zhao Wenjun , Li Changfeng
Published: October 2020

In this paper, 6063 aluminum alloy for common building profiles is used as the research object. The effect of 6063 aluminum alloy on the microstructure and properties of 6063 aluminum alloy is studied by adding a new type of Al-Ti-C-La master alloy. The results show that Al-Ti-C-La master alloy has an obvious influence on grain refinement of 6063 aluminum alloy. With the addition of Al-Ti-C-La master alloy, the grain size decreased significantly. When the additional amount of Al-Ti-C-La master alloy is 1%, the grain size is reduced from 482 μm to 121 μm. Rare earth La is mainly distributed near the Mg2Si phase and β-AlFeSi, and complex compounds such as AlFeSiMgLa are formed. After aging for 270 days based on T6 heat treatment, the tensile strength, and elongation of 6063 aluminum alloy increase with the addition of Al-Ti-C-La master alloy, while Vickers hardness decreases gradually. When the content of Al-Ti-C-La master alloy is 1%, the tensile strength, elongation, and Vickers hardness of 6063 aluminum alloy reach 177.2 MPa, 17.8% and 60.9 HV respectively, and the tensile strength is increases by 16.3%. The elongation rate increased by 50.8%, the Vickers hardness decreased by 15.4%, and the ductile fracture was the main fracture of the alloy.
Effect of the matrix material and electroplating process on the microstructure and properties of isolation switch contacts
Authors: Qianqian Yang , Zhang Changle , Yuan Liu , Molin Zhao , Yao Wang , Xinghai Shao , Shouhong Xue , Biao Wang , Yu Xu , Yutong Lv
Published: October 2020

In the KI system, Ag plating, hard-Ag plating and graphene-Ag plating were prepared on the surface of the copper and Cu–Cr alloy matrix materials by the electrodeposition method. The purpose of this paper is to define the copper-based material and related plating process suitable for the contacts of the isolating switch, obtaining excellent comprehensive properties and revealing the strengthening mechanism and wear mechanism of contact materials. Copper alloy was obtained by smelting in a high-frequency vacuum induction furnace, and then cold rolled. Effects of different plating processes and matrix materials on the microstructure, bonding degree between the plating and matrix, microhardness, contact resistance and wear resistance of copper-based contact materials were studied. The results showed that the matrix and the plating are well bonded. Both the Cu–Cr alloy matrix and the hard-Ag plating were rich in a large number of nano twins, dislocations and precipitates, which can strengthen the matrix and the plating. Moreover, they are beneficial to obtaining contact materials with high strength, high toughness and high conductivity. The contact resistance of the 3 kinds of plating changed little. The contact resistance of the Ag plating was the smallest, which was the largest of the hard-Ag plating, increased by 19.5%. The hard-Ag plating has the highest hardness and best wear resistance. Under the same test conditions, the combination of the hard-Ag plating and the Cu–Cr alloy matrix enables the copper-based contact material to obtain good cooperation of hardness, wear resistance and conductivity, and the comprehensive performance is the best.
Dictionary selection for compressed sensing of EEG signals using sparse binary matrix and spatiotemporal sparse Bayesian learning
Authors: Dey Manika Rani , Shiraz Arsam , Sharif Saeed , Lota Jaswinder , Demosthenous Andreas
Published: October 2020

Online monitoring of electroencephalogram (EEG) signals is challenging due to the high volume of data and power requirements. Compressed sensing (CS) may be employed to address these issues. Compressed sensing using a sparse binary matrix, owing to its low power features, and reconstruction/decompression using spatiotemporal sparse Bayesian learning have been shown to constitute a robust framework for fast, energy efficient and accurate multichannel bio-signal monitoring. EEG signal, however, does not show a strong temporal correlation. Therefore, the use of sparsifying dictionaries has been proposed to exploit the sparsity in a transformed domain instead. Assuming sparsification adds values, a challenge, therefore, in employing this CS framework for the EEG signal, is to identify the suitable dictionary. Using real multichannel EEG data from 15 subjects, in this paper, we systematically evaluate the performance of the framework when using various wavelet bases while considering their key attributes namely number of vanishing moments and coherence with sensing matrix. We identified Beylkin as the wavelet dictionary leading to the best performance. Using the same dataset, we then compared the performance of Beylkin with the discrete cosine basis, often used in the literature, and the alternative of not using a sparsifying dictionary. We further demonstrate that using dictionaries (Beylkin and Discrete Cosine Transform (DCT)) may improve performance tangibly only for a high compression ratio (CR) of 80% and with smaller block sizes, as compared to using no dictionaries.
Role of defects and phonons in bandgap dynamics of monolayer WS2 at high carrier densities
Authors: Brasington Alexandra , Golla Dheeraj , Dave Arpit , Chen Bin , Tongay Sefaattin , Schaibley John , LeRoy Brian J , Sandhu Arvinder
Published: October 2020

We conduct ultrafast pump-probe spectroscopy in monolayer WS2 at high pump fluences to gain direct insight into interactions between a high density of carriers, defects, and phonons. We find that defects in the lattice play a major role in determining the relaxation dynamics by trapping the photoexcited carriers and acting as non-radiative recombination centers that emit phonons. In the high carrier density regime explored in our experiments, we observe substantial changes in the transient absorbance signal at unexpectedly long-time delays which we attribute to phonon-induced band gap modification. Our probe frequency dependent measurements and modeling indicate a renormalization of the bandgap by up to 23 meV. These results highlight the importance of defects and phonons for optical applications of monolayer transition metal dichalcogenides.
Clinical significance and immunogenomic landscape analyses of the immune cell signature based prognostic model for patients with breast cancer
Authors: Wang Shiyuan , Xiong Yuqiang , Zhang Qi , Su Dongqing , Yu Chunlu , Cao Yiyin , Pan Yi , Lu Qianzi , Zuo Yongchun , Yang Lei
Published: October 2020

Breast cancer is one of the most common types of cancers and the leading cause of death from malignancy among women worldwide. Tumor-infiltrating lymphocytes are a source of important prognostic biomarkers for breast cancer patients. In this study, based on the tumor-infiltrating lymphocytes in the tumor immune microenvironment, a risk score prognostic model was developed in the training cohort for risk stratification and prognosis prediction in breast cancer patients. The prognostic value of this risk score prognostic model was also verified in the two testing cohorts and the TCGA pan cancer cohort. Nomograms were also established in the training and testing cohorts to validate the clinical use of this model. Relationships between the risk score, intrinsic molecular subtypes, immune checkpoints, tumor-infiltrating immune cell abundances and the response to chemotherapy and immunotherapy were also evaluated. Based on these results, we can conclude that this risk score model could serve as a robust prognostic biomarker, provide therapeutic benefits for the development of novel chemotherapy and immunotherapy, and may be helpful for clinical decision making in breast cancer patients.
Transmission of high-frequency vocalizations from hummingbirds living in diverse habitats
Authors: Duque F G , Rodriguez-Saltos C A , Monteros M F , Wilczynski W
Published: October 2020

Some species of Andean hummingbirds produce high-frequency vocalizations which exceed the vocal range of most birds. They also challenge our understanding of the role of habitat structure in the evolution of vocal signals because these hummingbirds live in strikingly different habitats, ranging from cloud forest to high-altitude grasslands. Although these vocalizations are produced at high frequencies, they exhibit considerable variation in frequency content and temporal structure. The calls of the hummingbirds from the cloud forest are simpler and have a narrow frequency range compared to the complex song of the grasslands hummingbird. We hypothesized that each of the three high-frequency vocalizations is adapted for transmission in their habitat. We characterized the transmission of high-frequency vocal signals in the cloud forest and in the grasslands. All vocalizations attenuated and degraded substantially at short distances, suggesting that they are adapted for short-range communication. The simple vocalizations of the cloud-forest species transmitted better in both environments compared to the complex song of the grasslands hummingbird, probably due to relaxed constraints for high-frequency sounds in open habitats.
Phylogenetic patterns and ontogenetic origins of limb length variation in ecologically diverse lacertine lizards
Authors: Cordero Gerardo A , Maliuk Anastasiia , Schlindwein Xenia , Werneburg Ingmar , Yaryhin Oleksandr
Published: October 2020

Limb length is intrinsically linked to function and, ultimately, fitness. Thus, it can co-evolve with habitat structure, as exemplified by tropical lizards in highly heterogeneous environments. But does lizard limb length respond in a similar manner during adaptive diversification in temperate zones? Here, we examine variation in habitat preference and limb length in lacertine lizards from the Palaearctic. We tested the following three hypotheses: (1) species of the Lacertini tribe descended from a generalist ancestor and subsequently underwent habitat specialization; (2) specialized ecological roles are associated with relative limb length in extant species; and (3) interspecific differences in limb length emerge in embryonic development. Our comparisons supported an ancestral ‘rocky’ or ‘generalist’ habitat preference, and phenotype–habitat associations were particularly supported when examining size-adjusted forelimb length in 69 species that represented all known Lacertini genera. Moreover, we revealed an elevated interlimb ratio in high-vegetation species, which might be linked to climbing performance in species with relatively longer forelimbs. Furthermore, embryonic limb variation was detected solely against an Eremiadini outgroup species. Instead, hind limb length differences within Lacertini originated in post-hatching ontogeny. The mechanisms that modulate limb growth are likely to be limited in Lacertini, because adaptive morphological change might mirror historical contingency and the ecological context wherein this clade diversified.
The influence of domestication, insularity and sociality on the tempo and mode of brain size evolution in mammals
Authors: Castiglione Silvia , Serio Carmela , Piccolo Martina , Mondanaro Alessandro , Melchionna Marina , Di Febbraro Mirko , Sansalone Gabriele , Wroe Stephen , Raia Pasquale
Published: October 2020

The ability to develop complex social bonds and an increased capacity for behavioural flexibility in novel environments have both been forwarded as selective forces favouring the evolution of a large brain in mammals. However, large brains are energetically expensive, and in circumstances in which selective pressures are relaxed, e.g. on islands, smaller brains are selected for. Similar reasoning has been offered to explain the reduction of brain size in domestic species relative to their wild relatives. Herein, we assess the effect of domestication, insularity and sociality on brain size evolution at the macroevolutionary scale. Our results are based on analyses of a 426-taxon tree, including both wild species and domestic breeds. We further develop the phylogenetic ridge regression comparative method (RRphylo) to work with discrete variables and compare the rates (tempo) and direction (mode) of brain size evolution among categories within each of three factors (sociality, insularity and domestication). The common assertion that domestication increases the rate of brain size evolution holds true. The same does not apply to insularity. We also find support for the suggested but previously untested hypothesis that species living in medium-sized groups exhibit faster rates of brain size evolution than either solitary or herding taxa.
Molecular phylogeny and biogeography ofPabstiella(Pleurothallidinae: Orchidaceae) highlight the importance of the Atlantic Rainforest for speciation in the genus
Authors: Gutiérrez Morales Nicolás , Toscano De Brito Antonio L V , Silvério Righetto Mauad Anna Victoria , De Camargo Smidt Eric
Published: October 2020

Pabstiella consists of c. 130 epiphytic species in the Neotropics. We present a phylogenetic analysis based on nrITS, matK and trnH-psbA sequences from 59 species of the genus and 40 Pleurothallidinae and two Laeliinae and one Bletiinae as an outgroup, using maximum likelihood, Bayesian inference and maximum parsimony. We also performed molecular dating, biogeographical analyses and ancestral morphological character reconstruction. Our results confirm the monophyly of Pabstiella with strong support. Ten clades are inferred and are herein proposed as sections. Pabstiella originated in the Andes and the Atlantic Rainforest in the Late Miocene (c. 7.93 Mya) in an epoch when these biomes were probably connected. A main vicariance event divided an early-diverging lineage that inhabited the Andes from an Atlantic Rainforest lineage that diversified in this region during the Pliocene and Pleistocene, mainly in the Serra do Mar in south-eastern Brazil. Our findings also suggest that the Atlantic Rainforest may have played an important role in the origin of subtribe Pleurothallidinae. The morphological character reconstruction showed high levels of homoplasy, with few recognized synapomorphies associated with stems and petals. Other characters related to the habit and stems were identified as important in the evolutionary history of the genus.
Intergenerational Transmission of Cortical Sulcal Patterns from Mothers to their Children
Authors: Ahtam Banu , Turesky Ted K , Zöllei Lilla , Standish Julianna , Grant P Ellen , Gaab Nadine , Im Kiho
Published: October 2020

Intergenerational effects are described as the genetic, epigenetic, as well as pre- and postnatal environmental influence parents have on their offspring’s behavior, cognition, and brain. During fetal brain development, the primary cortical sulci emerge with a distinctive folding pattern that are under strong genetic influence and show little change of this pattern throughout postnatal brain development. We examined intergenerational transmission of cortical sulcal patterns by comparing primary sulcal patterns between children (N = 16, age 5.5 ± 0.81 years, 8 males) and their biological mothers (N = 15, age 39.72 ± 4.68 years) as well as between children and unrelated adult females. Our graph-based sulcal pattern comparison method detected stronger sulcal pattern similarity for child–mother pairs than child-unrelated pairs, where higher similarity between child–mother pairs was observed mostly for the right lobar regions. Our results also show that child–mother versus child-unrelated pairs differ for daughters and sons with a trend toward significance, particularly for the left hemisphere lobar regions. This is the first study to reveal significant intergenerational transmission of cortical sulcal patterns, and our results have important implications for the study of the heritability of complex behaviors, brain-based disorders, the identification of biomarkers, and targets for interventions.
European East–West divide in kidney disease: the need to understand the drivers of chronic kidney disease outcomes
Authors: Carriazo Sol , Ortiz Alberto
Published: October 2020

In this issue of ckj, Sever et al. (A roadmap for optimizing chronic kidney disease patient care and patient-oriented research in the Eastern European nephrology community. Clin Kidney J, this issue) present a roadmap for optimizing chronic kidney disease (CKD) patient care and patient-oriented research in Eastern Europe. The document clearly identifies current unmet needs and proposes corrective actions. Focusing on CKD epidemiology and outcomes, it collects evidence pointing to an East–West gradient for some key risk factors for CKD development. Thus, the prevalence of diabetes, raised blood pressure, obesity and tobacco use is higher in Eastern than in Western Europe. These risk factors may contribute to the higher CKD prevalence in Eastern Europe, which for the Eastern-most countries may be more than 2-fold higher than in Western Europe. The problem is compounded by the lower prevalence of dialysis and transplantation in Eastern Europe, especially in lower income countries. The combination of higher prevalence of CKD with lower prevalence of renal replacement therapy would be expected to result in higher CKD-associated mortality, but this is not the case. CKD-associated mortality may even be lower in the Eastern-most European countries than in Western Europe. The reasons for this discrepancy should be studied, since it may reveal serious additional healthcare issues, potentially related to high mortality from other non-communicable diseases (NCDs). If this is the case and the high mortality from other NCD is successfully addressed, pressure will further mount on renal replacement capacity needs in Eastern Europe.
Transcatheter aortic valve-in-valve post-dilatation as an overlooked risk factor of delayed coronary obstruction: a case report
Authors: Marchese Alfredo , Tarantini Giuseppe , Tito Antonio , Colombo Antonio
Published: October 2020

Background

The risk of coronary obstruction during transcatheter aortic valve-in-valve replacement (VIV-TAVR) in patients deemed at high risk for surgical re-intervention is still a concerning issue.

Case summary

A 78-year-old woman with a past medical history of hypertension, chronic kidney disease, and rheumatoid arthritis was referred for a symptomatic and severely stenotic surgical Mitroflow n.21 bio-prosthesis and was subsequently recommended for a VIV procedure. Multiple anatomical risk factors for coronary occlusion required a pre-emptive coronary chimney stenting protection. The implantation of an Evolut-R 23 mm valve resulted in a gradient of 21 mmHg thus, a post-dilatation with an 18 mm balloon was performed. Both electrocardiographic and haemodynamic parameters remained excellent, however, a hazardous leaflet dislodgment became evident. Regardless, a prophylactic chimney stenting was performed because of the operator’s perceived high risk of late coronary occlusion.

Discussion

The implantation of transcatheter valves inside failed surgically implanted aortic bio-prosthesis is broadly recognized as a safe and less-invasive alternative to repeated high-risk surgery. Although procedural success is achieved in the great majority of patients, this therapy may be jeopardized by rare but serious complications such as impending or established acute coronary occlusion. Several specific anatomical and procedural risk factors have been identified and primary coronary prevention strategies are often mandatory when they arise. Valve-in-valve post-dilation has been overlooked in its role as an additional risk factor of late coronary obstruction. Therefore, chimney stenting, performed after balloon post-dilation to prevent delayed coronary obstruction, even if the acute coronary event does not occur intra-procedurally, is strongly advisable.
Long-term clinical outcomes after major bleeding in patients with atrial fibrillation: the Fushimi AF registry
Authors: Ogawa Hisashi , An Yoshimori , Ishigami Kenjiro , Ikeda Syuhei , Doi Kosuke , Hamatani Yasuhiro , Fujino Akiko , Ishii Mitsuru , Iguchi Moritake , Masunaga Nobutoyo , Esato Masahiro , Tsuji Hikari , Wada Hiromichi , Hasegawa Koji , Abe Mitsuru , Lip Gregory Y H , Akao Masaharu ,   Fushimi AF Registry investigators
Published: October 2020

Aims

Oral anticoagulants reduce the risk of ischaemic stroke but may increase the risk of major bleeding in atrial fibrillation (AF) patients. Little is known about the clinical outcomes of patients after a major bleeding event. This study assessed the outcomes of AF patients after major bleeding.

Methods and results

The Fushimi AF Registry is a community-based prospective survey of the AF patients in Fushimi-ku, Kyoto, Japan. Analyses were performed on 4304 AF patients registered by 81 institutions participating in the Fushimi AF Registry. We investigated the demographics and outcomes of AF patients who experienced major bleeding during follow-up period. During the median follow-up of 1307 days, major bleeding occurred in 297 patients (6.9%). Patients with major bleeding were older than those without (75.6 vs. 73.4 years; P < 0.01). They were more likely to have pre-existing heart failure (33.7% vs. 26.7%; P < 0.01), history of major bleeding (7.7% vs. 4.0%; P < 0.01), and higher mean HAS-BLED score (2.05 vs.1.73; P < 0.01). On landmark analysis, ischaemic stroke or systemic embolism occurred in 17 patients (3.6/100 person-years) after major bleeding and 227 patients (1.7/100 person-years) without major bleeding, with an adjusted hazard ratio (HR) of 1.93 [95% confidence interval (CI), 1.06–3.23; P = 0.03]. All-cause mortality occurred in 97 patients with major bleeding (20.0/100 person-years) and 709 (5.1/100 person-years) patients without major bleeding [HR 2.73 (95% CI, 2.16–3.41; P < 0.01)].

Conclusion

In this community-based cohort, major bleeding is associated with increased risk of subsequent all-cause mortality and thromboembolism in the long-term amongst AF patients.

Trial registration

https://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000005834. (last accessed 22 October 2020)
Effect of Consecutive Alternating Administration of a Triple Combination of Anti-Enteroviral Compounds in Mice Infected with Coxsackievirus B3
Authors: Stoyanova Adelina , Galabov Angel S
Published: October 2020

A novel approach for treatment of enterovirus infections was characterized. Application of treatment course of consecutive alternating administration (CAA) of triple combination of enterovirus replication inhibitors in experimental infections (20 MLD50) with coxsackievirus B3 (CVB3) strains in newborn mice is presented. It was established that in infection with cardiotropic Woodruff strain the combination of pleconaril, МDL-860 and oxoglaucine (PMO) subjected to the CAA scheme, a significant protective effect was observed. Monotherapeutic courses as well as simultaneously daily applied PMO were without effect. Analogous data were observed at experimental infection with the neurotriopic Nancy strain of CVB3. Following IC50 values of virus samples taken every day from target organs of infected animals during the whole period of study, a drug-resistance was established in monotherapy with compounds-partners in the PMO combination. At courses by the treatment scheme CAA of PMO development of drug-resistance was not established, but an increased susceptibility to the effect of the inhibitor-components in the combination was proven. Toxicity of PMO applied via the CAA scheme and in the monotherapeutic courses in both healthy and CVB3 infected animals was recorded. All data obtained prove the potential of the CAA treatment scheme for development of effective chemotherapy of enterovirus infections.