bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID-19 Infection and Its Influence in Otorhinolaryngology-Head and Neck Surgery
Authors: Parilli-Troconis Daniella , Baptista Peter , Marcano-Lozada Marcel , Goncalves Stefania , Shahal David , Chiossone-Kerdel Juan Armando
Published: September 2020

Introduction The novel coronavirus disease 2019 pandemic has rapidly spread worldwide, challenging healthcare resources and communities to an unprecedent degree. Simultaneously, the amount of clinical and scientific information released has overwhelmed journal platforms.

Objectives This review aims to summarize the available diagnostic tools and current guidelines to safely assist patients while limiting the exposure of otolaryngologists during this pandemic.

Data Synthesis Key articles were retrieved from the following databases: PubMed, Lancet, Springer Nature, BioMed Central, JAMA network and MEDLINE, as well as updated documents from the Spanish Ministry of Health, World Health Organization, Centers for Disease Control and Prevention, Spanish Association of Surgeons, ENT-UK, American College of Surgeons, and American Academy of Otolaryngology-Head and Neck Surgery. The terms used for the search were: COVID-19, Test COVID, Surgery in COVID, 2019-nCoV, ‘coronavirus’, and SARS-CoV-2. A total of 10,245 papers were retrieved. The inclusion criteria for the review included: COVID-19 testing (n = 531), society guidelines for otolaryngology-head and neck surgery patient care in the outpatient clinic (n = 10) and surgical (n = 18) settings. Studies not related to COVID-19 diagnosis were excluded.

Conclusion Healthcare institutions around the world are outlining their own protocols regarding laboratory testing and personnel protective equipment usage based upon medical societies recommendations during the COVID-19 pandemic. We have summarized the available laboratory tests and their respective sensitivity and specificity. Moreover, clinical guidelines from different societies were reviewed and summarized to facilitate guidance for otolaryngologists in the operating room and in the clinical settings.
Noninvasive Self-monitoring of Blood Glucose at Your Fingertips, Literally!: Smartphone-Based Photoplethysmography
Authors: Mazzu-Nascimento Thiago , Leal Ângela Merice de Oliveira , Nogueira-de-Almeida Carlos Alberto , de Avó Lucimar Retto da Silva , Carrilho Emanuel , Silva Diego Furtado
Published: September 2020

Diabetes is a chronic disease and one of the major public health problems worldwide. It is a multifactorial disease, caused by genetic factors and lifestyle habits. Brazil had ∼ 16.8 million individuals living with diabetes in 2019 and is expected to reach 26 million people by 2045. There are global increasing needs for the development of noninvasive diagnostic methods and use of mobile health, mainly in face of the pandemic caused by the coronavirus disease 2019 (COVID-19). For daily glycemic control, diabetic patients use a portable glucometer for glycemic self-monitoring and need to prick their fingertips three or more times a day, generating a huge discomfort throughout their lives. Our goal here is to present a review with very recent emerging studies in the field of noninvasive diagnosis and to emphasize that smartphone-based photoplethysmography (spPPG), powered by artificial intelligence, might be a trend to self-monitor blood glucose levels. In photoplethysmography, a light source travels through the tissue, interacts with the interstitium and with cells and molecules present in the blood. Reflection of light occurs as it passes through the biological tissues and a photodetector can capture these interactions. When using a smartphone, the built-in flashlight is a white light-emitting LED and the camera works as a photodetector. The higher the concentration of circulating glucose, the greater the absorbance and, consequently, the lesser the reflected light intensity will be. Due to these optical phenomena, the signal intensity captured will be inversely proportional to the blood glucose level. Furthermore, we highlight the microvascular changes in the progression of diabetes that can interfere in the signals captured by the photodetector using spPPG, due to the decrease of peripheral blood perfusion, which can be confused with high blood glucose levels. It is necessary to create strategies to filter or reduce the impact of these vascular changes in the blood glucose level analysis. Deep learning strategies can help the machine to solve these challenges, allowing an accurate blood glucose level and interstitial glucose prediction.
Giant Lipomas of the Hand. Our Experience
Authors: Balvís-Balvís Patricia , Yañez-Calvo Javier , Castro-Menéndez Manuel , Ferreirós-Conde María José
Published: September 2020

Objective Giant lipomas are benign tumors larger than 5 cm in size that are very uncommun in the hand, with the extant literature limited to case reports and small case series. The aim of the present study is to describe our experience with giant lipomas at the level of the hand, reviewing the most important aspects in relation to their diagnosis and treatment.

Material and Methods We present 6 patients treated in our service with giant lipomas of the hand between 2007 and 2015. Four cases only presented difficulty in grasping and mobilizing the hand due to the large size of the lipoma. Two cases were accompanied by a clinical feature of compression of the median nerve in relation to its location within the carpal tunnel.

Results All patients underwent surgery, and a complete excision of the lipoma was performed. The functional results have been satisfactory in all cases.

Conclusions Giant lipomas of the hand are infrequent tumors of slow growth, generally asymptomatic, although they can cause a compressive pathology due to the great size that they reach. Magnetic resonance imaging is an especially useful test to locate and accurately determine the size of the lesion in view of its surgical excision. After surgery, it is important to make a differential diagnosis with low-grade liposarcomas through an anatomopathological study, since both, macroscopically, have similar characteristics.
Wiedemann–Steiner Syndrome: A Rare Differential Diagnosis of Neurodevelopmental Delay and Dysmorphic Features
Authors: Carman Kursat Bora , Kaplan Emre , Aslan Cefa Nil , Kocagil Sinem , Cilinigr Oguz , Yarar Coskun
Published: September 2020

Wiedemann–Steiner syndrome (WSS) is a rare genetic disorder characterized by dysmorphic features, neurodevelopmental delay, growth retardation, and hypertrichosis cubiti. It is caused by pathogenic variants in the KMT2A gene. Here, we report a child with WSS presented with neurodevelopmental delay. Genetic analysis revealed a heterozygous c.2312dupC (p.Ser774Valfs*11) variant at the KMT2A gene that was classified as pathogenic in dbSNP (rs1057518649). To the best of our knowledge, this is the first patient of WSS from Turkey. This case draws attention to the diagnosis of WSS in children with neurodevelopmental delay.
Fetal Macrocephaly: A Novel Sonographic Finding in Congenital Myotonic Dystrophy
Authors: Shinar Shiri , Balakumar Parry , Shah Vibhuti , Chong Karen , Uster Tami , Chitayat David
Published: September 2020

Objective Sonographic clues to the diagnosis of congenital myotonic dystrophy (CDM) are limited, particularly in the absence of family history of myotonic dystrophy (DM). We reviewed cases of CDM for unique prenatal findings.

Study Design A single-center case series of fetuses with CMD with characteristic prenatal findings confirmed postnatally.

Results Four fetuses with pre- or postnatally diagnosed CDM presented with macrocephaly in utero. While head measurements were appropriate for gestational age until midgestation, third-trimester head circumference and biparietal diameter were both >2 standard deviation (SD) above the mean in all. Abdominal and femur measurements were otherwise appropriate for gestation. Postnatally, the occipitofrontal circumference was >2 SD above the mean in all, confirming the diagnosis of macrocephaly.

Conclusion CDM should be included in the differential diagnosis of third-trimester macrocephaly, especially in the presence of additional sonographic clues and when maternal medical history and physical examination are suggestive of DM.
Histological Assessment of Wallerian Degeneration of the Rat Tibial Nerve Following Crush and Transection Injuries
Authors: Kerns James M. , Walter James S. , Patetta Michael J. , Sood Anshum , Hussain Awais K. , Chung Joyce J. , Deshpande Abhishek , DesLaurier Justin T. , Dieter Raymond A. , Siemionow Maria , Seiler Figen A. , Amirouche Farid M.L. , Gonzalez Mark H.
Published: September 2020

Background Wallerian degeneration (WD) following peripheral nerve injury (PNI) is an area of growing focus for pharmacological developments. Clinically, WD presents challenges in achieving full functional recovery following PNI, as prolonged denervation of distal tissues for an extended period of time can irreversibly destabilize sensory and motor targets with secondary tissue atrophy. Our objective is to improve upon histological assessments of WD.

Methods Conventional methods utilize a qualitative system simply describing the presence or absence of WD in nerve fibers. We propose a three-category assessment that allows more quantification: A fibers appear normal, B fibers have moderate WD (altered axoplasm), and C fibers have extensive WD (myelin figures). Analysis was by light microscopy (LM) on semithin sections stained with toluidine blue in three rat tibial nerve lesion models (crush, partial transection, and complete transection) at 5 days postop and 5 mm distal to the injury site. The LM criteria were verified at the ultrastructural level. This early outcome measure was compared with the loss of extensor postural thrust and the absence of muscle atrophy.

Results The results showed good to excellent internal consistency among counters, demonstrating a significant difference between the crush and transection lesion models. A significant decrease in fiber density in the injured nerves due to inflammation/edema was observed. The growth cones of regenerating axons were evident in the crush lesion group.

Conclusion The ABC method of histological assessment is a consistent and reliable method that will be useful to quantify the effects of different interventions on the WD process.
A 2 kW S-band RF source for multipactor research utilizing GaN HEMTs
Authors: Esser B. , Shaw Z. C. , Dickens J. C. , Neuber A. A.
Published: September 2020

A high power, pulsed RF source designated for use in multipactor research is described. Four gallium nitride high electron mobility transistors from Cree/Wolfspeed, capable of 700 W in long pulse mode (500 W rated output), are combined to achieve a maximum rated output of 2.8 kW with a pulse length of ∼100 µs. Custom splitters/combiners are used due to the power levels considered in addition to a custom power and sequencing control system to ensure the proper biasing and sequencing of the relatively delicate depletion mode GaN devices. With high efficiency and small size, gallium nitride devices present a good solution for lab based sources, and this paper aims to provide information helpful in the construction of such a source. The multipactor phenomenon itself is studied within a high impedance waveguide section—achieved with a tapered impedance transformer—placed in a WR284 traveling wave ring resonator, which increases the effective power up to a factor of 20, or ∼40 kW.
Strong spin-dephasing in a topological insulator-paramagnet heterostructure
Authors: Lapano Jason , Mazza Alessandro R. , Li Haoxiang , Mukherjee Debangshu , Skoropata Elizabeth M. , Ok Jong Mok , Miao Hu , Moore Robert G. , Ward Thomas Z. , Eres Gyula , Lee Ho Nyung , Brahlek Matthew
Published: September 2020

The interface between magnetic materials and topological insulators can drive the formation of exotic phases of matter and enable functionality through the manipulation of the strong spin polarized transport. Here, we report that the transport processes that rely on strong spin-momentum locking in the topological insulator Bi2Se3 are completely suppressed by scattering at a heterointerface with the kagome-lattice paramagnet, Co7Se8. Bi2Se3–Co7Se8–Bi2Se3 trilayer heterostructures were grown using molecular beam epitaxy, where magnetotransport measurements revealed a substantial suppression of the weak antilocalization effect for Co7Se8 at thicknesses as thin as a monolayer, indicating a strong dephasing mechanism. Bi2−xCoxSe3 films, in which Co is in a non-magnetic 3+ state, show weak antilocalization that survives to higher than x = 0.4, which, in comparison with the heterostructures, suggests that the unordered moments of Co2+ act as a far stronger dephasing element. This work highlights several important points regarding coherent transport processes involving spin-momentum locking in topological insulator interfaces and how magnetic materials can be integrated with topological materials to realize both exotic phases and novel device functionality.
Surface electronic structure and dynamics of lead halide
perovskites
Authors: Niesner Daniel
Published: September 2020

A number of studies investigating the electronic structure of well-defined lead halide perovskite surfaces have emerged in the last five years. Surfaces and their interfaces can not only have considerable effects on the performance of devices such as solar cells but also open a window into the intrinsic electronic properties of lead halide perovskites. This is particularly true for angle-resolved photoelectron spectroscopy, which is possibly the technique giving the most direct access to the electronic (band) structure of a material. The pump–probe version of the technique, two-photon photoelectron spectroscopy, gives information about the femtosecond and picosecond electron dynamics following optical excitation. This review summarizes the recent progress made using these surface-sensitive techniques. In addition, differences between the optical and electronic properties between the near-surface (hundreds of nm) and the deep bulk material of single crystals are discussed. We point out critical issues concerning the comparability between individual results arising from the different depths and timescales probed, or from differing environmental conditions such as the temperature or the surrounding atmosphere.
Tight-binding analysis of helical states in carbyne
Authors: Gunasekaran Suman , Venkataraman Latha
Published: September 2020

Carbyne is a linear allotrope of carbon that is composed of a chain of sp-hybridized carbon atoms. Through appropriate engineering of the chain termination, carbyne can harbor helical states where the π-electron delocalization twists along the axis of the chain. Herein, we present a comprehensive analysis of these helical states at the tight-binding level. We demonstrate that, in general, the molecular orbital coefficients of the helical states trace out an ellipse, in analogy to elliptically polarized light. Helical states can be realized in a model, inspired by the structure of cumulene, which considers a chain terminated by sp2-hybridized atoms oriented at a nontrivial dihedral angle. We provide a complete analytic solution for this model. Additionally, we present a variation of the model that yields perfect helical states that trace out a circle as opposed to an ellipse. Our results provide a deeper understanding of helical states and lay a foundation for more advanced levels of theory.
A methodology for adding thixotropy to Oldroyd-8 family of viscoelastic models for characterization of human blood
Authors: Armstrong Matthew , Tussing Joseph
Published: September 2020

Recent work modeling the rheological behavior of human blood indicates that blood has all the hallmark features of a complex material, including shear-thinning, viscoelastic behavior, a yield stress, and thixotropy. After decades of modeling only the steady state blood data, steady state models, such as the Casson, Carreau–Yasuda, and Herschel–Bulkley models, have been developed. The advancement and evolution of blood modeling to transient flow conditions now has renewed interest. Using recently collected human blood rheological data from a strain-controlled rheometer, we show and compare a new modeling effort using the Oldroyd-8 viscoelastic framework as a foundation. This foundation is enhanced with the application of a recent thixotropic framework recently published to model elastic and viscoelastic contributions from the microstructure to three Oldroyd-8 families of models: the corotational Jeffreys model, the convected Maxwell model, and the Oldroyd 4-constant model. The elastic and viscoelastic stress contributions from the microstructure are then linearly superimposed with the viscoelastic backbone solution for stress given by the Oldroyd-8 family of models. Demonstrated here is a parametric analysis, model comparison, and a comparison of the new approaches made using the ability to predict large amplitude oscillatory shear and uni-directional large amplitude oscillatory shear flow. The new family of models can solve components of the full stress tensor, making them ideal for use with a future conformation tensor to evolve, model, and better understand the effects of the microstructure of human blood. In addition, there is now a methodology to model the normal forces of blood.
A Bayesian inference framework for compression and prediction of quantum states
Authors: Rath Yannic , Glielmo Aldo , Booth George H.
Published: September 2020

The recently introduced Gaussian Process State (GPS) provides a highly flexible, compact, and physically insightful representation of quantum many-body states based on ideas from the zoo of machine learning approaches. In this work, we give a comprehensive description of how such a state can be learned from given samples of a potentially unknown target state and show how regression approaches based on Bayesian inference can be used to compress a target state into a highly compact and accurate GPS representation. By application of a type II maximum likelihood method based on relevance vector machines, we are able to extract many-body configurations from the underlying Hilbert space, which are particularly relevant for the description of the target state, as support points to define the GPS. Together with an introduced optimization scheme for the hyperparameters of the model characterizing the weighting of modeled correlation features, this makes it possible to easily extract physical characteristics of the state such as the relative importance of particular correlation properties. We apply the Bayesian learning scheme to the problem of modeling ground states of small Fermi–Hubbard chains and show that the found solutions represent a systematically improvable trade-off between sparsity and accuracy of the model. Moreover, we show how the learned hyperparameters and the extracted relevant configurations, characterizing the correlation of the wave function, depend on the interaction strength of the Hubbard model and the target accuracy of the representation.
Vertical Transmission
Authors: Lyras Dena
Published: September 2020

I will begin this Vertical Transmission by hoping that you and your families are all healthy and well, and coping during this very confused and frightening time. Microbiology and public health are certainly at the forefront of community and government attention at this time, and rapid solutions are being sought to deal with the SARS-CoV-2 pandemic. Unfortunately, funding for discovery research that will provide the required solutions for this and other microbial threats is lacking. For this reason, the ASM Executive (Dena Lyras, Roy Robins-Browne, Kate Seib, Anthony Baker, Rebecca LeBard), together with Mark Schembri, Jonathan Iredell, Priscilla Johanesen, Enzo Palombo, Cheryl Power, and Deborah
Williamson, have prepared the following statement to share with you and the broader community on this matter.
The risk from Security Sensitive Biological Agents (SSBAs) and the need for response
Authors: Gebbie Sandra , Kaufer Alexa , Rawlinson William
Published: September 2020

In 2011, the International Health Regulations Review Committee of the WHO suggested ‘The world is ill-prepared to respond to a severe influenza pandemic or to any similarly global, sustained and threatening public-health emergency’. This was presumably partly in response to known threats that had occurred over the previous decade – Severe Acute Respiratory Syndrome (SARS) in 2003,H1N1 pandemic influenza in 2009, avian influenza H5N1 in 2004, and predated outbreaks with Zikavirus (2015–2016), Ebolavirus (2014), and most recently SARS CoV2, the causative agent of COVID-19 (2020).
Integrated chromosomal and plasmid sequence analyses reveal diverse modes of carbapenemase gene spread among
Klebsiella pneumoniae
Authors: David Sophia , Cohen Victoria , Reuter Sandra , Sheppard Anna E. , Giani Tommaso , Parkhill Julian ,   the European Survey of Carbapenemase-Producing Enterobacteriaceae (EuSCAPE) Working Group,   the ESCMID Study Group for Epidemiological Markers (ESGEM), Rossolini Gian Maria , Feil Edward J. , Grundmann Hajo , Aanensen David M. , Koraqi Andi , Lacej Denada , Apfalter Petra , Hartl Rainer , Glupczynski Youri , Huang Te-Din , Strateva Tanya , Marteva-Proevska Yuliya , Andrasevic Arjana Tambic , Butic Iva , Pieridou-Bagatzouni Despo , Maikanti-Charalampous Panagiota , Hrabak Jaroslav , Zemlickova Helena , Hammerum Anette , Jakobsen Lotte , Ivanova Marina , Pavelkovich Anastasia , Jalava Jari , Österblad Monica , Dortet Laurent , Vaux Sophie , Kaase Martin , Gatermann Sören G. , Vatopoulos Alkiviadis , Tryfinopoulou Kyriaki , Tóth Ákos , Jánvári Laura , Boo Teck Wee , McGrath Elaine , Carmeli Yehuda , Adler Amos , Pantosti Annalisa , Monaco Monica , Raka Lul , Kurti Arsim , Balode Arta , Saule Mara , Miciuleviciene Jolanta , Mierauskaite Aiste , Perrin-Weniger Monique , Reichert Paul , Nestorova Nina , Debattista Sonia , Mijovic Gordana , Lopicic Milena , Samuelsen Ørjan , Haldorsen Bjørg , Żabicka Dorota , Literacka Elżbieta , Caniça Manuela , Manageiro Vera , Kaftandzieva Ana , Trajkovska-Dokic Elena , Damian Maria , Lixandru Brandusa , Jelesic Zora , Trudic Anika , Niks Milan , Schreterova Eva , Pirs Mateja , Cerar Tjasa , Oteo-Iglesias Jesús , Pérez-Vázquez María , Giske Christian , Sjöström Karin , Gür Deniz , Cakar Aslı , Woodford Neil , Hopkins Katie , Wiuff Camilla , Brown Derek J. , Werner Guido , Couto Natacha
Published: September 2020

Significance

In many clinically important bacteria, antibiotic resistance genes are primarily carried on plasmids. These can spread horizontally between different strains and species. However, current surveillance systems track chromosomal lineages of bacteria only, leading to an incomplete understanding of how resistance spreads, from within an individual hospital to across country borders. We present an integrated, high-resolution analysis of both chromosome and plasmid sequences using
Klebsiella pneumoniae
isolates sampled during a European survey. We show that carbapenemase genes, which confer resistance to last-line antibiotics, have spread in diverse ways including via one plasmid/multiple lineages (
bla
OXA-48-like
), multiple plasmids/multiple lineages (
bla
VIM
,
bla
NDM
), and multiple plasmids/one lineage (
bla
KPC
). These different trajectories must be considered in genomic surveillance systems and the design of new interventions.
14-3-3ζ–TRAF5 axis governs interleukin-17A signaling
Authors: McGowan Jenna , Peter Cara , Kim Joshua , Popli Sonam , Veerman Brent , Saul-McBeth Jessica , Conti Heather , Pruett-Miller Shondra M. , Chattopadhyay Saurabh , Chakravarti Ritu
Published: September 2020

Significance

Blocking IL-17A signaling is an attractive therapy in treating autoimmune diseases. Current IL-17A blockers target both signaling branches, leading to inhibition of TRAF6-based IL-6 production, and TRAF5-based CXCL-1 production. Global suppression of both branches is of concern due to the critical role IL-17A plays in the host-defense mechanisms. Our study shows that 14-3-3ζ is necessary for IL-17A–stimulated IL-6 production. We also found that 14-3-3ζ represses TRAF5-mediated suppression of IL-17A–stimulated IL-6 induction. Taken together, our results show a unique cross-talk between two branches via the 14-3-3ζ–TRAF5 axis that regulates the IL-17A signaling output. These foundational results can lead to the design of a unique inhibitor targeting a specific branch of IL-17A signaling and obtaining the desired output.
Morphological evolution of NbC particles at the interface of niobium–iron diffusion couple
Authors: Bai Haiqiang , Zhong Lisheng , Wei Junzhe , Lv ZhenLin , Xu Yunhua
Published: September 2020

To investigate the morphological evolution of the NbC phase, a niobium-cast iron diffusion couple was designed and fabricated. The two-dimensional (2D) and three-dimensional (3D) growth morphology of NbC particles were analysed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphological evolution mechanism of NbC particles was also discussed. The results reveal that from the interface of the Nb wire/NbC-Fe diffusion layer to the cast iron, as the thickness of the NbC-Fe diffusion layer increases, the morphology of NbC particles changed from the nearly spherical to truncated cube, then to a perfect cube. The evolution of particle morphology is mainly attributed to the change in the C/Nb ratio and the existence of Fe atoms affecting the relative growth rates of the {111} and {100} facets on a NbC crystal.
Identifying #Addiction Concerns on Twitter during the COVID-19 Pandemic: A Text Mining Analysis
Authors: Glowacki Elizabeth M. , Wilcox Gary B. , Glowacki Joseph B.
Published: September 2020

Background

The 2019 Novel Coronavirus (COVID-19) is responsible for thousands of deaths and hospitalizations. To curb the spread of this highly transmissible disease, governments enacted protective guidelines for its citizens, including social distancing and stay-at-home orders. These restrictions on social interactions can be especially problematic for individuals managing or recovering from addiction given that treatment often involves access to services and resources that became limited or even unavailable at this time. Social media sites like Twitter serve as a space for users to post questions and concerns about timely topics and allow for researchers to track common themes among the public. The goal of this study was to identify how the public was discussing addiction on Twitter during the COVID pandemic.

Methods

We performed a text mining analysis to analyze tweets that contained “addiction” and “covid” to capture posts from the public that illustrated comments and concerns about addiction during the COVID-19 pandemic. We report on 3,301 tweets captured between January 31 and April 23, 2020. The study was conducted in the United States, but contained tweets from multiple countries.

Results

The most prevalent topics had to do with services offered by Acadia Healthcare and Serenity Healthcare Centers, attempts to manage time while home, difficulties of coping with alcoholism amidst rising sales of alcohol, and attention to ongoing health crises (e.g.,., opioids, vaping). Additional topics included affordable telehealth services, research from France on the relationship between nicotine and COVID-19, concerns about gambling addiction, and changing patterns in substance misuse as drug availability varies.

Conclusions

Analyzing Twitter content enables health professionals to identify the public's concerns about addiction during the COVID-19 pandemic. Findings from text mining studies addressing timely health topics can serve as preliminary analyses for building more comprehensive models, which can then be used to generate recommendations for the larger public and inform policy.
The Production of Knowledge in Different Sectors: a model and some hypotheses
Authors: Foray Dominique , Hargreaves David
Published: September 2020

We develop a model that supports the rapid production and accumulation of knowledge in different sectors. The model combines two dimensions: the first is the mode of knowledge production, either scientific or humanistic; and the second concerns the strength of knowledge spillovers,
generated by competition and/or cooperation. The model is then applied to the knowledge base in different sectors. The contrasting historical trajectories of knowledge production and dissemination in medicine and education in England are examined in the light of the continuing debate about
the nature of educational research and the role of teachers within it.
The RNA binding protein FMR1 controls selective exosomal miRNA cargo loading during inflammation
Authors: Wozniak Ann L. , Adams Abby , King Kayla E. , Dunn Winston , Christenson Lane K. , Hung Wei-Ting , Weinman Steven A.
Published: September 2020

Cells respond to inflammatory disease states by releasing exosomes containing highly specific protein and RNA cargos, but how inflammation alters cargo specificity and secretion of exosomes is unknown. We show that increases in exosome secretion induced by either viral infection or LPS/ATP exposure result from inflammasome activation and subsequent caspase-1–dependent cleavage of the trafficking adaptor protein RILP. This cleaved form of RILP promotes the movement of multivesicular bodies toward the cell periphery and induces selective exosomal miRNA cargo loading. We have identified a common short sequence motif present in miRNAs that are selectively loaded into exosomes after RILP cleavage. This motif binds the RNA binding protein FMR1 and directs miRNA loading into exosomes via interaction with components of the ESCRT (endosomal sorting complex required for transport) pathway. These results indicate that inflammasome-mediated RILP cleavage, and sequence-specific interactions between miRNAs and FMR1, play a significant role in exosome cargo loading and enhanced secretion during cellular inflammatory responses.
Determining the eccentricity of Mercury’s orbit from its transit
Authors: Souza J V A , Bertuola A C , Filho V S
Published: September 2020

In the present work, we propose a procedure to allow undergraduate students to obtain two experimental values of the Mercury–Sun distance, using geometric compositions of photographs of Mercury’s transits at its perihelion and its aphelion. From those distances, the model also allows students to calculate the value of the eccentricity of Mercury’s orbit. Our procedure is validated against published values based on Mercury’s transits in 2006 and 2016.
A novel rare cell sorting microfluidic chip based on magnetic nanoparticle labels
Authors: Yang Mengzheng , Wu Xinyu , Li Helin , Cui Guangchao , Bai Zhongyang , Wang Lin , Kraft Michael , Liu Guozhen , Wen Lianggong
Published: September 2020

Rare cell sorting with magnetic nanoparticles labels (MNPs) has been achieved by the aid of microfluidic chip, which offers an easy processing approach to sort the rare cells from a trace original sample. However, its applications have been limited in large part due to the presence of some redundant MNPs in the sorted target cells affecting the purity of sorted target cells. This paper demonstrates a novel rare cell-sorting microfluidic chip based on polydimethylsiloxane (PDMS) and the MNPs. The cell-sorting system combines the mechanisms of magnetic sorting, the geometry selection and the microfluidic manoeuvre to achieve high efficient cell sorting with real-time monitoring. The device with an array of microcolums acting as a micro-sieve is capable of separating target cells, background cells and redundant MNPs simultaneously while having the target cells from the chip outlet for subsequent studies. A finite element method simulation is implemented to quantify the experimental conditions. Green fluorescent Hela cells (Hela-GFP) with different concentrations are used in the cell sorting experiments. The experimental results show the ability of this microfluidic chip to capture MNPs-labelled target cells with high capture accuracy and the maximum recovery rate up to 99.7%. The proposed approach provides an effective and reliable tool for biological and clinical researches, and paves the way to an automated rare cell sorting system.
Neutrino(antineutrino)–nucleus interactions in the shallow- and deep-inelastic scattering regions
Authors: Athar M Sajjad , Morfín Jorge G
Published: September 2020

In

ν
/

ν

̄

–nucleon/nucleus interactions shallow inelastic scattering (SIS) is technically defined in terms of the four-momentum transfer to the hadronic system as non-resonant meson production with Q
2 ⪅ 1 GeV2. This non-resonant meson production intermixes with resonant meson production in a regime of similar effective hadronic mass W of the interaction. As Q
2 grows and surpasses this ≈1 GeV2 limit, non-resonant interactions begin to take place with quarks within the nucleon indicating the start of deep inelastic scattering (DIS). To essentially separate this resonant plus non-resonant meson production from DIS quark-fragmented meson production, a cut of 2 GeV in W of the interactions is generally introduced. However, since experimentally mesons from resonance decay cannot be separated from non-resonant produced mesons, SIS for all practical purposes in this review has been defined as inclusive meson production that includes non-resonant plus resonant meson production and the interference between them. Experimentally then for W ⪅ 2 GeV inclusive meson production with W ⪆ (M

N
+ M

π
) and all Q
2 is here defined as SIS, while for W ⪆ 2 GeV, the kinematic region with Q
2 ⪆ 1 GeV2 is defined as DIS. The so defined SIS and DIS regions have received varying degrees of attention from the community. While the theoretical/phenomenological study of ν–nucleon and ν–nucleus DIS scattering is advanced, such studies of a large portion of the SIS region, particularly the SIS to DIS transition region, have hardly begun. Experimentally, the SIS and the DIS regions for ν–nucleon scattering have minimal results and only in the experimental study of the ν–nucleus DIS region are there significant results for some nuclei. Since current and future neutrino oscillation experiments have contributions from both higher W SIS and DIS kinematic regions and these regions are in need of both considerable theoretical and experimental study, this review will concentrate on these SIS to DIS transition and DIS kinematic regions surveying our knowledge and the current challenges.
Teaching physics online through spreadsheets in a pandemic situation
Authors: Iqbal Majid , Ahmed Fayzan , Iqbal Arshad , Uddin Zaheer
Published: September 2020

Teaching physics with simulations is an interactive way of teaching physics to students. In recent years, many scientists have used spreadsheets for simulating topics in physics and other fields. Excel is a piece of user-friendly spreadsheet software. In this lockdown situation, spreadsheets are good tools to teach physics experiments online through simulation. In this paper, we present two examples which are simulated on an Excel spreadsheet. The examples include simulations of image formations by spherical mirrors with a ray diagram and a demonstration of Malus’ law.
A study of the impact of x-ray tube performance on angiography system imaging efficiency
Authors: Dehairs M , Bosmans H , Marshall N W
Published: September 2020

This work compared the impact of x-ray tube performance and automatic dose rate control (ADRC) parameter selection on system imaging efficiency of two Siemens angiography systems: a Siemens Megalix x-ray tube installed on an Artis Zee system (denoted ‘MEGALIX’) and a newer generation Gigalix x-ray tube installed on an Artis Q (denoted ‘GIGALIX’). A method was used that accounted for two potential sources of bias in this comparison: differences in radiation output between the x-ray tubes and differences between the x-ray detectors on the two systems. First, ADRC x-ray factors (tube voltage, tube current, pulse length, focus size, spectral prefilter) and radiation output were recorded as a function of poly(methyl) methacrylate (PMMA) thickness on the MEGALIX unit. These factors were then applied manually on the GIGALIX system and incident air kerma rate (IAKR) and signal difference to noise ratio (SDNR) were measured. Second, the ADRC on the GIGALIX system was used to give the x-ray factors and both IAKR and SDNR relevant to the GIGALIX based system directly. This method enabled the SDNR to be measured from images acquired on the same x-ray detector. SDNR and IAKR were measured on both systems using a PMMA phantom covering thicknesses from 6 cm to 40 cm. A small 0.3 mm iron insert was used to measure SDNR, which was then multiplied by modulation transfer function based weighting factors for focal spot blurring and motion blurring. These factors were evaluated for an object motion of 25 mm s−1 and at a spatial frequency of 1.4 mm−1 in the object plane, relevant to interventional cardiology, giving a spatial frequency dependent SDNR(u). In the second phase of the study, a technical figure of merit (FOM) was used to express imaging performance of both systems, calculated as SDNR2(u)/IAKR. Averaged over all phantom thicknesses, the FOM of the GIGALIX-based system was 42% and 73% higher compared to that of the MEGALIX based system, for fluoroscopy and acquisition mode respectively. The results indicate that increased x-ray tube power and smaller foci can improve overall system efficiency and reduce doses.
Depletion of atomic hydrogen in a high power helicon discharge
Authors: Cousens Samuel , Santoso Jesse , Corr Cormac S
Published: September 2020

Depletion of the ground state atomic hydrogen density has been directly measured using two-photon laser-induced fluorescence in a high-density helicon plasma. The depletion is correlated with the plasma pressure becoming increasingly higher than the neutral gas fill pressure. Spatially resolved measurements show depletion of atomic hydrogen in the centre of the discharge chamber. Temporally resolved measurements display a replenishment of atomic hydrogen in the plasma afterglow at high plasma densities in comparison to the typical two-step decay at lower plasma densities.
Using ultrathin double-layer gas-permeable capping metal to form sensitive low-power gas sensors
Authors: Madhaiyan Govindasamy , Chen Chao-Hsuan , Lin Hong-Cheu , Meng Hsin-Fei , Zan Hsiao-Wen
Published: September 2020

In this work, we investigated a simple, sensitive, and low-powered ammonia (NH3) gas sensor using a thin bi-layered metal capped on an organic semiconductor chemoresistor to deliver a sensitive response to NH3 (ppb level) at room temperature. An optimized thin bi-layered Al/Ag metal (2 nm/10 nm) successfully forms a gas-permeable structure to realize ppb-regime gas sensing better than other single-layered thin Ag, Al, or Au (12 nm) metal electrodes. The performance of the simple metal-capped gas sensor is greatly dependent on the surface roughness of the thin metal electrodes, and the very rough thin bi-layered metal Al/Ag (2 nm/10 nm) allows high gas penetration. The optimized device exhibits more than 10% response to 100 ppb NH3 at only 0.5 V. The simple, low-cost, highly sensitive, and low-powered gas sensors are promising for Internet of things applications.
Research on dynamic thermal performance of high-power ThinGaN vertical light-emitting diodes with different submounts
Authors: Raypah Muna E , Mahmud Shahrom , Devarajan Mutharasu , AlShammari Anoud Saud
Published: September 2020

Investigation of dynamic thermal performance is a key to improve the heat management of high-power (HP) vertical light-emitting diodes (VLEDs). Specifically, the thermal time constant is a crucial parameter for optimizing the design and reliability of HP LEDs. Herein, the dynamic thermal behavior of seven HP ThinGaN VLEDs with different constructions was demonstrated. The LEDs’ thermal parameters were measured through the thermal transient tester system by a forward voltage technique. A three-stage of multiexponential function model was applied to divide the transient response curve into three regions with different thermal properties. This study focused on analyzing the first region that involved the chip region (epitaxial layer, wafer bonding layer, and submount) and chip bonding layer. The submounts of the LEDs under consideration include silicon carbide (SiC), silicon (Si), sapphire (Al2O3), and germanium (Ge). The results revealed that with a qualified wafer bonding layer, the LED packages with SiC, Si, and Al2O3 submount presented the optimum thermal time constant, which was 85, 69, 75, and 81 ms, respectively.
Stability analysis of the optical field and spectrum characteristics inside the dual coupled microcavities
Authors: Xu Xin , Jin Xueying , Lu Yang , Gao Haoran , Cheng Jie , Yu Liandong
Published: September 2020

For improving the energy conversion efficiency from the pump to the available optical field in the microcavity, the dual coupled microcavities are proposed. Based on the coupled nonlinear Schrödinger equations, the optical field and spectrum characteristics inside the dual coupled microcavities can be studied, and the effect of the each parameter on the field is analyzed. Simulation results indicate that the bright soliton can exist in the coupled microcavities. The weak pump causes soliton breathers, even a sinusoidal field, while the increment of the pump power leads to the multi-pulse and chaos. Additionally, the trigger pulse has an important role to excite multi-pulse field and the mixed field. The diagram of the coupled field with various frequency detuning is also demonstrated. The significant soliton generates on the condition that the frequency of the first microcavity is in a certain range of several GHz. Theoretical analysis results are significant for studying the field in the dual coupled microcavities.
Structural, optical, antibacterial analysis of Se NPs synthesized by precipitation method
Authors: Dar Mohd Arif , Mala Nazir Ahmad , Dar G N , Satheesh Kumar S , Govindarajan D
Published: September 2020

In this paper Se NPs have been synthesised through precipitation technique by using different sorts of solvents such as sodium hydroxide, tin chloride, sodium borohydride, hydrochloric acid and citrus acid so as to consider its antibacterial activities. These Se NPs are characterised by experimental techniques such as UV-Vis spectrophotometer, SEM, TEM, FT-IR, XRD, EDX and antibacterial activities. Powder XRD analysis reveals the hexagonal phase (HCP) of Se NPs with average particle size of 27 nm. SEM and TEM reveal agglomerated spherical images with spherical shape and EDX spectra of the pure Se NPs show the peaks of pure selenium. Maximum absorption occurs in the range of 200–400 nm with an energy band gap of 3.58 eV. Presence of different functional groups liable for the production and stability of the Se NPs was confirmed by FT-IR spectrum. The antibacterial activity was achieved against two Gram-negative microorganisms (Escherichia coli, Salmonella typhi) and two Gram-positive microorganisms (Staphylococcus aureus, Streptococcus epidermidis).
Hierarchical mesoscale assembly of PbO2on 3D titanium felt/TiO2nanotubular array electrode for anodic decolourisation of RB-5 dye
Authors: Harito C , Zaidi S Z J , Bavykin D V , Martins A S , Yuliarto B , Walsh F C , de León C Ponce
Published: September 2020

Hierarchical PbO2nanoparticles (NPs) were grown by hydrothermal method on TiO2nanotubes (NTs) at 3D titanium felt, which is simple and scalable method. TiO2NTs were formed on titanium felt by anodising at 25 °C in environmentally friendly methanesulphonic acid solution. The growth of PbO2on the TiO2NTs depended on immersion time during hydrothermal synthesis and followed a LaMer-Dinegar burst kinetic model of nucleation and growth. PbO2formation began with rapid nucleation, followed by mesoscale assembly due to organic capping of poly(vinylpyrrolidinone). The electrochemical performance of 3D electrode was recorded in pH 3 sodium sulphate solutions containing Reactive Black 5 (RB-5) azo dye at 25 °C. The resulting hierarchical 3D electrode achieved 98% decolourisation after 50 min of anodic oxidation with a first order batch decay rate of 0.0875 min−1.
Molecular-scale descriptions and experimental characterizations of nitrocellulose soaked in pure liquid ethanol or diethyl ether respectively at room temperature
Authors: Liu Pingan , Sun Ruochen , Sui Penghua , Gao Song , Feng Zhichao , Zou Gaowan , Qi Hui
Published: September 2020

Studies on nitrocellulose (NC) mixtures with little solubilities were neglected in many cases previously. This investigation was performed to provide supplemental characterizations of NC and its soaked state with pure liquid ethanol or diethyl ether by simulations and practical methods. Above all, a short-chained NC model (polymerisation degree: 8) and a dried NC specimen were characterized for their substitution of nitrate and microstructure. It was confirmed that both the numerical model and practical specimen belonged to low-nitrated NC. The bonding information of a glycosyl unit and nitrate ester were summarized via first-principle calculations. Then, ReaxFF potential based Molecular Dynamic (MD) simulations and soaking tests on binary organic mixtures demonstrated that both ethanol and diethyl ether had limited solubility for our specified NC. However, potential energies and diffusion coefficients of both computational models showed that the interactions from ethanol molecules were relatively stronger than diethyl ether molecules. The viscosities of saturated NC solutions also proved this consequence, as the difference between pure ether and its filtered NC solution was only 0.02 mm2 s−1. Finally, the strong volatility of diethyl ether itself could keep the wetness of NC upper surface shortly, because this was an upward volatilization effect. Due to this effect, the penetration of NC-diethyl ether mixture was higher in the early period of penetration tests.
Zinc chloride modification of sage leaves powder and its application as an adsorbent for KMnO4 removal from aqueous solutions
Authors: Bani-Atta Suhair A
Published: September 2020

Sage Leaves Powder was modified by 30% w/w of Zink Chloride (ZnCl2) and used as a cheap adsorbent for potassium permanganate (KMnO4) adsorption from aqueous media. The characterization of the synthesized adsorbent showed diversity in its functional groups at 1030, 1700, and 2930 cm−1. The impact of experimental conditions on the adsorption was investigated. It was found that these experimental conditions except pH have positive effects on the efficiency of this adsorbent. The initial KMnO4 concentration of 1500 mg l−1, the temperature of 60 °C and the solution pH of 1.5 were found to be the ideal conditions in this adsorption. The equilibrium data were analyzed using three isotherm models. Langmuir model was found to be the best model applied in this work. The adsorption capacities were 714.29, 769.23, 833.33 and 909.09 (mg g−1) at 30, 40, 50 and 60 (°C), respectively. The parameters of the adsorption kinetics were evaluated by three kinetic models. The kinetic results confirm that the 2nd order described well the experimental data. Thermodynamic outcomes suggest that this adsorption is a spontaneous and endothermic process. The obtained results make from this adsorbent a good option for KMnO4 removal from wastewater in terms of its low-cost and adsorption performance.