bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective atomic layer reaction between GaN and SiN in HBr neutral beam etching
Authors: Ohori Daisuke , Sawada Takahiro , Sugawara Kenta , Okada Masaya , Nakata Ken , Inoue Kazutaka , Sato Daisuke , Samukawa Seiji
Published: May 2021

We investigated higher selective etching between SiN and GaN using an HBr neutral beam (NB) and found that it exhibited a more selective reaction compared to Cl2 NB. The etching rate of GaN mainly depended on the desorption rate of the etching product (GaClx or GaBrx) assisted by the bombardment of NB. As a result, in the case of the HBr neutral beam, the GaN etching rate was drastically decreased at the atomic layer level because the vapor pressure of the etching product, GaBrx, was much lower than that of GaClx. On the other hand, the dominant etching progression of SiN was mainly caused by neutral beam bombardment energy, and the desorption of the etching products (SiClx or SiBrx) was almost the same in both cases because the vapor pressures of the etching product, SiClx and SiBrx. In particular, in the case of the HBr neutral beam, the neutral beam energy dependence of the surface reaction layer of SiN was larger than that of Cl2 NB. As a result, the etching selectivity between SiN and GaN in HBr NB improved to 2.1 at 10 W of bias power, whereas that with Cl2 NB was saturated at 0.41 at more than 10 W of bias power. We found that the surface atomic layer etching reaction could precisely control the desorption rate of the etching product by optimizing the neutral beam bombardment energy and gas chemistry. The HBr neutral beam process can achieve atomic layer level selective reactions on the SiN/GaN structure.
Approaching ultrathin VO2 films on sapphire (001) substrates by biased reactive sputtering: Characteristic morphology and its effect on the infrared-light switching
Authors: Okimura Kunio , Sakai Joe , Kuwahara Masashi , Zaghrioui Mustapha , Uehara Yoichi
Published: May 2021

Ultrathin VO2 films with insulator-metal transition (IMT) were successfully fabricated on sapphire (001) substrates by utilizing radio frequency-biased reactive sputtering. We realized a 6 nm-thick VO2 film that shows resistance change over 2 orders of magnitude. Microscopic observations combined with energy dispersive x-ray analyses revealed characteristic networking morphology in VO2 films with thickness up to around 10 nm. It was found through micro-Raman analyses that a 30 nm-thick film possessed flat surface and ordered lattice with strong in-plane tensile stress. We evaluated the thickness dependence of optical switching performance for infrared-light. The results suggest that the thickness of the VO2 films should be carefully selected for realizing required performances of optical switching, which depends on not only IMT but also characteristic morphological aspects.
Impact of the Inclusion of an Aminoglycoside to the Initial Empirical Antibiotic Therapy for Gram-Negative Bloodstream Infections in Hematological Neutropenic Patients: a Propensity-Matched Cohort Study (AMINOLACTAM Study)
Authors: Albasanz-Puig A. , Gudiol C. , Puerta-Alcalde P. , Ayaz C. M. , Machado M. , Herrera F. , Martín-Dávila P. , Laporte-Amargós J. , Cardozo C. , Akova M. , Álvarez-Uría A. , Torres D. , Fortún J. , García-Vidal C. , Muñoz P. , Bergas A. , Pomares H. , Mercadal S. , Durà-Miralles X. , García-Lerma E. , Pallarès N. , Carratalà J.
Published: May 2021

To test the hypothesis that the addition of an aminoglycoside to a β-lactam antibiotic could provide better outcomes than β-lactam monotherapy for the initial empirical treatment of hematological neutropenic patients with subsequently documented Gram-negative bacillus (GNB) bloodstream infection (BSI), a multinational, retrospective, cohort study of GNB BSI episodes in hematological neutropenic patients in six centers (2010 to 2017) was conducted. Combination therapy (β-lactam plus aminoglycoside) was compared to β-lactam monotherapy.
RNase P Inhibitors Identified as Aggregators
Authors: Schencking Isabell , Schäfer Eva M. , Scanlan J. H. William , Wenzel Benjamin M. , Emmerich Rolf E. , Steinmetzer Torsten , Diederich Wibke E. , Schlitzer Martin , Hartmann Roland K.
Published: May 2021

RNase P is an essential enzyme responsible for tRNA 5′-end maturation. In most bacteria, the enzyme is a ribonucleoprotein consisting of a catalytic RNA subunit and a small protein cofactor termed RnpA. Several studies have reported small-molecule inhibitors directed against bacterial RNase P that were identified by high-throughput screenings.
In Vitro
Viral Evolution Identifies a Critical Residue in the Alphaherpesvirus Fusion Glycoprotein B Ectodomain That Controls gH/gL-Independent Entry
Authors: Vallbracht Melina , Lötzsch Henriette , Klupp Barbara G. , Fuchs Walter , Vollmer Benjamin , Grünewald Kay , Backovic Marija , Rey Felix A. , Mettenleiter Thomas C.
Published: May 2021

The class III fusion protein glycoprotein B (gB) drives membrane fusion during entry and spread of herpesviruses. To mediate fusion, gB requires activation by the conserved gH/gL complex by a poorly defined mechanism.
Functional and Comparative Analysis of Centromeres Reveals Clade-Specific Genome Rearrangements in
Candida auris
and a Chromosome Number Change in Related Species
Authors: Narayanan Aswathy , Vadnala Rakesh Netha , Ganguly Promit , Selvakumar Pavitra , Rudramurthy Shivaprakash M. , Prasad Rajendra , Chakrabarti Arunaloke , Siddharthan Rahul , Sanyal Kaustuv
Published: May 2021

Candida auris
, the killer fungus, emerged as different geographical clades, exhibiting multidrug resistance and high karyotype plasticity. Chromosomal rearrangements are known to play key roles in the emergence of new species, virulence, and drug resistance in pathogenic fungi.
A
Streptococcus
Quorum Sensing System Enables Suppression of Innate Immunity
Authors: Rahbari Kate M. , Chang Jennifer C. , Federle Michael J.
Published: May 2021

Streptococcus pyogenes
is restricted to human hosts and commonly causes superficial diseases such as pharyngitis; it can also cause severe and deadly manifestations including necrotizing skin disease or severe postinfectious sequelae like rheumatic heart disease. Understanding the complex mechanisms used by this pathogen to manipulate host defenses could aid in developing new therapeutics to treat infections.
MicroRNA-Mediated Regulation of Initial Host Responses in a Symbiotic Organ
Authors: Moriano-Gutierrez Silvia , Ruby Edward G. , McFall-Ngai Margaret J.
Published: May 2021

Animals often acquire their microbiome from the environment at each generation, making the initial interaction of the partners a critical event in the establishment and development of a stable, healthy symbiosis. However, the molecular nature of these earliest interactions is generally difficult to study and poorly understood.
Rapid Response of Nitrogen Cycling Gene Transcription to Labile Carbon Amendments in a Soil Microbial Community
Authors: Chuckran Peter F. , Fofanov Viacheslav , Hungate Bruce A. , Morrissey Ember M. , Schwartz Egbert , Walkup Jeth , Dijkstra Paul
Published: May 2021

A large portion of activity in soil microbial communities occurs in short time frames in response to an increase in C availability, affecting the biogeochemical cycling of nitrogen. These changes are of particular importance as nitrogen represents both a limiting nutrient for terrestrial plants as well as a potential pollutant.
Oral Epithelial Cells Distinguish betweenCandidaSpecies with High or Low Pathogenic Potential through MicroRNA Regulation
Authors: Horváth Márton , Nagy Gábor , Zsindely Nóra , Bodai László , Horváth Péter , Vágvölgyi Csaba , Nosanchuk Joshua D. , Tóth Renáta , Gácser Attila
Published: May 2021

A relatively new topic within the field of immunology involves the role of miRNAs in innate as well as adaptive immune response regulation. In recent years, posttranscriptional regulation of host-pathogenic fungal interactions through miRNAs was also suggested.
A MicroRNA Gene Panel Predicts the Vaginal Microbiota Composition
Authors: Cheng Liqin , Kaźmierczak Dominika , Norenhag Johanna , Hamsten Marica , Fransson Emma , Schuppe-Koistinen Ina , Olovsson Matts , Engstrand Lars , Hydbring Per , Du Juan
Published: May 2021

Vaginal microbiota is correlated with women’s health, where a non-
Lactobacillus
-dominated community predisposes women to a higher risk of disease, including human papillomavirus (HPV). However, the molecular relationship between the vaginal microbiota and host is largely unexplored.
Elucidating the Regulatory Elements for Transcription Termination and Posttranscriptional Processing in the Streptomyces clavuligerus Genome
Authors: Hwang Soonkyu , Lee Namil , Choe Donghui , Lee Yongjae , Kim Woori , Jeong Yujin , Cho Suhyung , Palsson Bernhard O. , Cho Byung-Kwan
Published: May 2021

Streptomyces
sp. is a great source of bioactive secondary metabolites, including antibiotics, antifungal agents, antiparasitic agents, immunosuppressant compounds, and other drugs. Secondary metabolites are synthesized via multistep conversions of the precursor molecules from primary metabolism, governed by multicomplex enzymes from secondary metabolite biosynthetic gene clusters.
Spinal Cord Injury Changes the Structure and Functional Potential of Gut Bacterial and Viral Communities
Authors: Du Jingjie , Zayed Ahmed A. , Kigerl Kristina A. , Zane Kylie , Sullivan Matthew B. , Popovich Phillip G.
Published: May 2021

To our knowledge, this is the first article to apply metagenomics to characterize changes in gut microbial population dynamics caused by a clinically relevant model of central nervous system (CNS) trauma. It also utilizes the most current approaches in genome-resolved metagenomics and viromics to maximize the biological inferences that can be made from these data.
Supplemental Material: Postglacial slip distribution along the Teton normal fault (Wyoming, USA), derived from tectonically offset geomorphological features
Authors: Hampel A. , al. et
Published: May 2021

Figures S1–S4 show the scarp profiles sorted by the type of the displaced landforms. Table S1 provides scarp height and/or vertical separation values determined by earlier studies.
Predictive Intelligent Control of Oxygenation (PRICO) in preterm infants on high flow nasal cannula support: a randomised cross-over study
Authors: Dijkman Koen P , Mohns Thilo , Dieleman Jeanne P , van Pul Carola , Goos Tom G , Reiss Irwin KM , Andriessen Peter , Niemarkt Hendrik J
Published: May 2021

Objective

To investigate the efficacy of automated control of inspired oxygen (FiO2) by Predictive Intelligent Control of Oxygenation (PRICO) on the Fabian ventilator in maintaining oxygen saturation (SpO2) in preterm infants on high flow nasal cannula (HFNC) support.

Design

Single-centre randomised two-period crossover study.

Setting

Tertiary neonatal intensive care unit.

Patients

27 preterm infants (gestational age (GA) <30 weeks) on HFNC support with FiO2 >0.25.

Intervention

A 24-hour period on automated FiO2-control with PRICO compared with a 24-hour period on routine manual control (RMC) to maintain a SpO2 level within target range of 88%–95% measured at 30 s intervals.

Main outcome measures

Primary outcome: time spent within target range (88%–95%). Secondary outcomes: time spent above and below target range, in severe hypoxia (SpO2 <80%) and hyperoxia (SpO2 >98%), mean SpO2 and FiO2 and manual FiO2 adjustments.

Results

15 patients received PRICO-RMC and 12 RMC-PRICO. The mean time within the target range increased with PRICO: 10.8% (95% CI 7.6 to 13.9). There was a decrease in time below target range: 7.6% (95% CI 4.2 to 11.0), above target range: 3.1% (95% CI 2.9 to 6.2) and in severe hypoxia: 0.9% (95% CI 1.5 to 0.2). We found no difference in time spent in severe hyperoxia. Mean FiO2 was higher during PRICO: 0.019 (95% CI 0.006 to 0.030). With PRICO there was a reduction of manual adjustments: 9/24 hours (95% CI 6 to 12).

Conclusion

In preterm infants on HFNC support, automated FiO2-control by PRICO is superior to RMC in maintaining SpO2 within target range. Further validation studies with a higher sample frequency and different ventilation modes are needed.
Use of flow diverter stent for treatment of a cervical carotid artery dissection and pseudoaneurysm causing Horner’s syndrome
Authors: Beaty Narlin , Patel Monisha , Martinez Christian , Hollis Lutheria
Published: May 2021

A 28-year-old man in 2004 was identified with a spontaneous pseudoaneurysm and distal left cervical internal carotid artery (ICA) dissection. The patient was followed conservatively for 12 years with cross-sectional imaging. The patient was initially diagnosed with an acute left ICA dissection, with significant luminal narrowing. Follow-up imaging revealed the dissection was not completely healed, and a small pseudoaneurysm, about 4 mm in size, was formed in the distal left cervical ICA. During the 12-year observation period, the patient’s pseudoaneurysm expanded from 4.0 mm to 9.0 mm, and the patient presented with ptosis, anisocoria and myosis. Flow diverter embolisation resulted in a radiographic cure of the pseudoaneurysm and resolution of Horner’s syndrome.
Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study
Authors: Bogan Carley M , Kaczmarek Jessica V , Pierce Janene M , Chen Sheau-chiann , Boyd Kelli L , Calcutt Marion W , Bridges Thomas M , Lindsley Craig W , Nadelmann Jennifer B , Liao Albert , Hsieh Terry , Abramson David H , Francis Jasmine H , Friedman Debra L , Richmond Ann , Daniels Anthony B
Published: May 2021

Background

Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort.

Methods

Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 μg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. Patients: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan.

Results

Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC90 across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%–79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 μV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged.

Conclusions

Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.
Advance care planning for home health staff: a systematic review
Authors: Gleeson Aoife , Noble Simon , Mann Mala
Published: May 2021

Background

Advance care planning (ACP) is a process where patients express their wishes regarding their future healthcare. Its importance has been increasingly recognised in the past decade. As increasing numbers of elderly people are living in care homes, the aim of this review was to identify the most effective ACP interventions to train/educate all levels of healthcare professionals working in care homes.

Design

A systematic review. Two independent reviewers undertook screening, data extraction and quality assessment.

Data sources

 Searched from inception to June 2018: Ovid Medline, Ovid Medline in process, Ovid Embase, Cochrane Central Register of Controlled Trials, EBSCO Cinahl and Ovid PsycINFO.

Results

Six studies were included: three before and after studies, one cluster randomised controlled trial (RCT), one non-blinded RCT and one qualitative study. Five studies reported on ACP documentation, three on impact on ACP practice and three studies on healthcare-related outcomes. All quantitative studies reported an improvement in outcomes. In the three studies reporting on health-related outcomes, one showed significant reductions in hospitalisation rate, days and healthcare costs; one reported significant reductions in hospital deaths; and the third showed reductions in hospital days and deaths. A meta-analysis could not be performed due to the heterogeneity of the outcome measures. The included qualitative study highlighted perceived challenges to implementing an educational programme in the care home setting.

Conclusion

There is limited evidence for the effectiveness of ACP training for care home workers. More well-designed studies are needed.

Trial registration number

CRD42016042385 .
Whole-genome sequencing
Authors: Morris Huw R , Houlden Henry , Polke James
Published: May 2021

The costs of whole-genome sequencing have rapidly decreased, and it is being increasingly deployed in large-scale clinical research projects and introduced into routine clinical care. This will lead to rapid diagnoses for patients with genetic disease but also introduces uncertainty because of the diversity of human genomes and the potential difficulties in annotating new genetic variants for individual patients and families. Here we outline the steps in organising whole-genome sequencing for patients in the neurology clinic and emphasise that close liaison between the clinician and the laboratory is essential.
Characterizing the delays in adequate thromboprophylaxis after TBI
Authors: Dhillon Navpreet K , Hashim Yassar M , Berezin Naomi , Yong Felix , Conde Geena , Mason Russell , Ley Eric J
Published: May 2021

Background

We sought to compare enoxaparin dosing for venous thromboembolism (VTE) prophylaxis in trauma patients with and without traumatic brain injury (TBI) to better understand the time and dose required to reach target anti-Xa levels. Our hypothesis was that patients with TBI have significant delays in the initiation of adequate pharmacological prophylaxis and require a higher enoxaparin dose than currently recommended.

Methods

The medical records of trauma patients who received enoxaparin dosing based on anti-Xa trough levels between August 2014 and October 2016 were reviewed. Patients were included if their anti-Xa trough level reached the target range (0.1 IU/mL to 0.2 IU/mL).

Results

A total of 163 patients had anti-Xa levels within the target range of which 41 (25.2%) had TBI. Patients with TBI had longer delays before initiating enoxaparin (7.5 days vs. 1.5 days after admission, p<0.01) and were more likely to receive unfractionated heparin prior to enoxaparin (46.3% vs. 11.5%, p<0.01). Anti-Xa levels reached the target range later in patients with TBI (11 days vs. 5 days after admission, p<0.01). Enoxaparin 40 mg two times per day was the median dose required to reach the target anti-Xa levels for both cohorts. VTE rates were higher among patients with TBI (22.0% vs. 9.0%, p=0.03). Four patients (9.8%) had progression of their intracranial hemorrhage prior to receiving enoxaparin, although none progressed during enoxaparin administration.

Conclusion

Among patients with TBI who reached target anti-Xa levels, 11 days after admission were required to reach a median enoxaparin dose of 40 mg two times per day. Unfractionated heparin was used as pharmacological prophylaxis in about half of these patients. The delay in reaching the target anti-Xa levels and the use of unfractionated heparin likely contribute to the higher VTE rate in patients with TBI.

Level of evidence

Level III, therapeutic.
Reply to the comment by Morales et al. on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”
Authors: Lausen C.L. , Proctor Michael F. , Paetkau David , Nagorsen David W. , Govindarajulu Purnima , Burles Doug , Blejwas Karen
Published: May 2021

A.E. Morales et al. (2021. Can. J. Zool. 99(5): 415–422) provided no new evidence to alter the conclusions of C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279). We present background information, relevant comparisons, and clarification of analyses to further strengthen our conclusions. The genesis of the original “evotis–keenii” study in British Columbia (Canada) was to differentiate Myotis keenii (Merriam, 1895) (Keen’s myotis), with one of the smallest North American bat distributions, from sympatric Myotis evotis (H. Allen, 1864) (long-eared myotis), using something other than the suggested post-mortem skull size comparison, but no differentiating trait could be found, leading to the molecular genetics examination of C.L. Lausen et al. (2019). We present cumulative data that rejects the 1979 hypothesis of M. keenii as a distinct species. A.E. Morales et al. (2021) inaccurately portray C.L. Lausen et al.’s (2019) question and results; present inaccurate morphological and outdated distribution data; overstate the impact of homoplasy without supporting evidence; and misinterpret evidence of population structure.
Probing loop effects in wrong-sign Yukawa coupling region of Type-II 2HDM
Authors: Su Wei
Published: May 2021

In the framework of 2HDM, we explore the wrong-sign Yukawa region with direct and indirect searches up to one-loop level. The direct searches include the latest$$H/A \rightarrow f{\bar{f}}, VV, Vh, hh$$H/A→ff¯,VV,Vh,hhreports at current LHC, and the study of indirect Higgs precision measurements works with current LHC, future HL-LHC and CEPC. At tree level of Type-II 2HDM, for degenerate heavy Higgs mass$$m_A=m_H=m_{H^\pm }<800$$mA=mH=mH±<800GeV, the wrong-sign Yukawa regions are excluded largely except for the tiny allowed region around$$\cos (\beta -\alpha )\in (0.2,0.3)$$cos(β-α)∈(0.2,0.3)under the combined Higgs constraints. The excluded region is also nearly independent of parameter$$m_{12}$$m12or$$\lambda v^2=m_A^2-m_{12}^2/(\sin \beta \cos \beta )$$λv2=mA2-m122/(sinβcosβ). The situation changes a lot after including loop corrections to the indirect searches, for example$$m_A=1500 \text {~GeV}$$mA=1500GeV, the region with$$\lambda v^2<0$$λv2<0will be stronger constrained to be totally excluded. Whilst parameter space with$$\lambda v^2>0$$λv2>0would get larger survived wrong-sign region for$$m_A=800 ~\text {~GeV}$$mA=800GeVcompared to it at tree level. We also conclude Higgs direct searches works better on constraining$$\lambda v^2 \approx 0$$λv2≈0GeV range than theoretical constraints. We also find that the loop-level wrong-sign Yukawa limit only occurs at mass decoupling scale.
Investigations on the effects of obstacles on the surfaces of blades of the centrifugal pump to suppress cavitation development
Authors: Zhao Weiguo , Guo Bao
Published: May 2021

This paper proposes a new method that obstacles are attached to both the suction and pressure surfaces of the blades to suppress cavitation development. A centrifugal pump with a specific speed of 32 is selected as the physical model to perform the external characteristic and cavitation performance experiments. SST [Formula: see text] turbulence model and Zwart cavitation model were employed to simulate the unsteady cavitation flow in the pump. The results indicate that the numerical simulation results are in good agreement with the experimental counterparts. After the obstacles are arranged, the maximum head decrease is only 1.37%, and the relative maximum drop of efficiency is 1.12%. Obstacles have minimal impacts on the variations of head and efficiency under all flow rate conditions. The distribution of vapor volume in the centrifugal pump is significantly reduced after obstacles are arranged and the maximum fraction reduction is 53.6%. The amplitude of blade passing frequency decreases significantly. While obstacles decrease the intensity of turbulent kinetic energy near the wall in the impeller passages to effectively reduce the distribution of cavitation bubbles, and control the development of cavitation. After the obstacles are set, the strength of the vortex in the impeller passages is weakened significantly, the shedding of the vortex is suppressed, flow in the impeller becomes more stable.
An Antipodal Vivaldi Antenna with Elliptical Slots for Low-Cost Rectenna Applications
Authors: Pereira E. T. , Paz H. P. , Silva V. S. , Cambero E. V. V. , Casella I. R. S. , Capovilla C. E.
Published: May 2021

In this paper, a low-cost rectenna based on an antipodal Vivaldi antenna (AVA) with elliptical slots (AVA-ES) is developed and analyzed. The design of AVA-ES, when compared to a reference AVA, presents significant improvements in directivity and gain (58% at 2.45[Formula: see text]GHz for both), evidencing its advantages for using in rectennas. The proposed rectenna prototype presents satisfactory results at 2.45[Formula: see text]GHz, such as conversion efficiency for low-power input levels (27% at [Formula: see text]10[Formula: see text]dBm) and maximum output voltage (550[Formula: see text]mV), that supports its use for radio-frequency energy harvesting (RFEH).
A Novel Oriented CNT fiber/PDMS Elastic Conductive Composite with Reversible Two-Stage Conductivity
Authors: Xiong Yilian , Ma Ruiqi , Jiang Min , Lin Wenxin , Zhu Hongliang , Chen Jianjun
Published: May 2021

In recent years, intensive researches have been stimulated to explore the promising prospect for carbon nanotubes (CNTs) in the fabrication of novel polymer sensor composites. In this study, the fabrication and properties of a flexible and stretchable composite elastomer fabricated from direct-spun carbon nanotube fiber (yarns) were presented, and the novel CNT fiber/polydimethylsiloxane (PDMS) elastic conductive composite shows the reversible two-stage conductivity owing to its unique structure of CNTs fabricated by the floating catalyst chemical vapor deposition (FCCVD). As the strain increased from 0% to 10% (Stage I), stretching the oriented CNT fiber/PDMS elastic conductive composite induces a constant decrease in the conductive pathways and contact areas between CNTs depending on the stretching distance. However, this composite elastomer will retain almost stable electrical resistance while being stretched by over 10% (Stage II). Furthermore, the composite shows very little variation in resistance under 187 stretching–releasing cycles up to a pre-strain level of 6%, indicating the outstanding stability and repeatability in performance as stretchable conductors. The microstructure, reversible two-stage conductive properties and mechanism were also discussed.
LIMIT-TO-ARBITRAGE FACTORS AND IVOL RETURNS PUZZLE: EMPIRICAL EVIDENCE FROM TAIWAN BEFORE AND DURING COVID-19
Authors: DUONG KHOA DANG , NGUYEN QUI NHAT , LE TRUONG VINH , NGUYEN DIEP VAN
Published: May 2021

This paper examines the impacts of limit-to-arbitrage factors on the returns of the idiosyncratic volatility (IVOL) puzzle in Taiwan before and during the Covid-19 pandemic. Although various studies explore the relationship between stock returns and IVOL, the empirical findings are mixed. We are motivated by unique market microstructures in Taiwan, such as individual investors’ aggressive trading volume and low transaction costs in Taiwan, discouraging arbitrary trading activities. Our empirical results indicate a negative relationship between IVOL and stock returns by using data from the Taiwan stock market. However, the IVOL anomaly does not exist during the Covid-19 pandemic, even in the small stocks sample. Besides, our findings suggest that four proxies of limits-to-arbitrage, such as reversal, transaction costs, turnover and Amihud’s Illiquidity, have statistically significant impacts on the return of IVOL anomaly in Taiwan except for the pandemic period. Finally, our finding suggests that the stock turnover is the only limit-to-arbitrage factor that helps investors earn arbitrary profits during the COVID-19 period.
Coping with Unrest in the Periphery of China: Comparative Case Studies of Thailand, Myanmar and HKSAR
Authors: Chiam Jason Chiah Sern , Lim Tai Wei
Published: May 2021

This paper examines the case studies of three East Asian entities (Thailand, Myanmar and Hong Kong) battling both the COVID-19 coronavirus pandemic as well as socio-political unrest simultaneously. While Thailand/Myanmar and Hong Kong are different in geographical/demographic sizes and the former two are sovereign states while the latter is a Special Administrative Region (SAR), they have similar challenges in experiencing cosmopolitan pro-democracy movements (made up of young activists) pitted against the governments determined to maintain control in what political scientists may characterize as illiberal political systems. While Thailand and Myanmar may be much larger in terms of geographical/demographic sizes, much of the recent political activism occurred in the capital city of Bangkok (a city of about 8 million people) and Yangon (also having about 7 million in population and being the former capital of Myanmar before the military elites had moved the capital to Naypyidaw in anticipation of political unrests). In the case of Myanmar, the demonstration and protests have effectively spread nationwide. Both cities are similar in size to Hong Kong that is with approximately 7 million inhabitants. Both Bangkok and Hong Kong are also cosmopolitan cities with high exposure to global commerce, ideas and tourism while Yangon is a fast-developing urban commercial capital city. In terms of ideologies and political systems, both Bangkok and Hong Kong have nominal liberal democratic systems that have limits imposed on political freedoms while Myanmar was liberalizing and democratizing before the military coup on February 1, 2020. These similarities make them suitable candidates for comparative studies, including analyzing their differences in managing the political challenges.
Toward a Holistic Approach to Verification and Validation of Autonomous Cognitive Systems
Authors: Ferrando Angelo , Dennis Louise A. , Cardoso Rafael C. , Fisher Michael , Ancona Davide , Mascardi Viviana
Published: May 2021

When applying formal verification to a system that interacts with the real world, we must use a
model
of the environment. This model represents an
abstraction
of the actual environment, so it is necessarily incomplete and hence presents an issue for system verification. If the actual environment matches the model, then the verification is correct; however, if the environment falls outside the abstraction captured by the model, then we cannot guarantee that the system is well behaved. A solution to this problem consists in exploiting the model of the environment used for statically verifying the system’s behaviour and, if the verification succeeds, using it also for validating the model against the real environment via runtime verification. The article discusses this approach and demonstrates its feasibility by presenting its implementation on top of a framework integrating the Agent Java PathFinder model checker. A high-level Domain Specific Language is used to model the environment in a user-friendly way; the latter is then compiled to trace expressions for both static formal verification and runtime verification. To evaluate our approach, we apply it to two different case studies: an autonomous cruise control system and a simulation of the Mars Curiosity rover.
GraphPEG
Authors: Lü Yashuai , Guo Hui , Huang Libo , Yu Qi , Shen Li , Xiao Nong , Wang Zhiying
Published: May 2021

Due to massive thread-level parallelism, GPUs have become an attractive platform for accelerating large-scale data parallel computations, such as graph processing. However, achieving high performance for graph processing with GPUs is non-trivial. Processing graphs on GPUs introduces several problems, such as load imbalance, low utilization of hardware unit, and memory divergence. Although previous work has proposed several software strategies to optimize graph processing on GPUs, there are several issues beyond the capability of software techniques to address.

In this article, we present GraphPEG, a graph processing engine for efficient graph processing on GPUs. Inspired by the observation that many graph algorithms have a common pattern on graph traversal, GraphPEG improves the performance of graph processing by coupling automatic edge gathering with fine-grain work distribution. GraphPEG can also adapt to various input graph datasets and simplify the software design of graph processing with hardware-assisted graph traversal. Simulation results show that, in comparison with two representative highly efficient GPU graph processing software framework Gunrock and SEP-Graph, GraphPEG improves graph processing throughput by 2.8× and 2.5× on average, and up to 7.3× and 7.0× for six graph algorithm benchmarks on six graph datasets, with marginal hardware cost.
The Netivus Manifesto
Authors: Severini Joseph , Mysore Radhika Niranjan , Sekar Vyas , Banerjee Sujata , Reiter Michael K.
Published: May 2021

We study operational issues faced by Small and Medium Enterprise (SME) network owners and find that SME network management practices have stagnated over the past decade, despite many recent advances in network management. Many of these advances target hyperscalers and ISPs and cannot be directly applied to SME networks that are operated with vastly different constraints. In our work, we outline these constraints and explain how they impact challenges around debugging, namely: representing, reproducing, and remediating network problems. This article takes a fresh look at these challenges in the light of SME practices around collaborative debugging and presents a roadmap aimed to help resolve SME operational issues quickly.
Teaching multivariable calculus and tensor calculus with computer algebra software
Authors: Ou Miao-jung Yvonne
Published: May 2021

To go from calculus of scalar functions of one variable to multivariate calculus of vector-valued functions is a steep learning curve for many students. It takes a lot of practice to get used to the new concepts such as the directional derivatives, the di.erentiability, the many types of first order di.erential operators, parameterization of surfaces and the fundamental theorems of integrals, e.g. the Divergence Theorem and the Stokes Theorem. Along the learning process of mastering the skills, the students often need to check whether the intermediate steps in the tedious calculations are correct. Unfortunately, this is beyond the capability of an ordinary calculator and the answers provided at the end of the books. This is where computer algebra software, such as Mathematica, can come to students' help. With the developed symbolic computation tools, the students can tweak a given problem, solve a new one by hand and then check the answer against the result obtained by using the computer algebra software.
Induction of renal tumor necrosis factor-α and other autacoids and the beneficial effects of hypertonic saline in acute decompensated heart failure
Authors: Gatzoflias Stergios , Hao Shoujin , Ferreri Nicholas R.
Published: May 2021

Although administration of hypertonic saline (HSS) in combination with diuretics has yielded improved weight loss, preservation of renal function, and reduction in hospitalization time in the clinical setting of patients with acute decompensated heart failure (ADHF), the mechanisms that underlie these beneficial effects remain unclear and additional studies are needed before this approach can be adopted on a more consistent basis. As high salt conditions stimulate the production of several renal autacoids that exhibit natriuretic effects, renal physiologists can contribute to the understanding of mechanisms by which HSS leads to increased diuresis both as an individual therapy as well as in combination with loop diuretics. For instance, since HSS increases TNF-α production by proximal tubule and thick ascending limb of Henle’s loop epithelial cells, this article is aimed at highlighting how the effects of TNF-α produced by these cell types may contribute to the beneficial effects of HSS in patients with ADHF. Although TNF-α produced by infiltrating macrophages and T cells exacerbates and attenuates renal damage, respectively, production of this cytokine within the tubular compartment of the kidney functions as an intrinsic regulator of blood pressure and Na+ homeostasis via mechanisms along the nephron related to inhibition of Na+-K+-2Cl− cotransporter isoform 2 activity and angiotensinogen expression. Thus, in the clinical setting of ADHF and hyponatremia, induction of TNF-α production along the nephron by administration of HSS may attenuate Na+-K+-2Cl− cotransporter isoform 2 activity and angiotensinogen expression as part of a mechanism that prevents excessive Na+ reabsorption in the thick ascending limb of Henle’s loop, thereby mitigating volume overload.
Restoration of Primary Anterior Teeth with Glass Fiber-Reinforced Post and Core: 3-Year Follow-Up Case Report
Authors: Afraa Salah , Raghad Hashim , Ayam Khalid , Aeshah Hamid
Published: May 2021

Background. Esthetic appearance of primary anterior teeth is one of the major demands in the dental field. Destructed anterior primary teeth due to caries is considered a major issue due to the difficulty in regaining the esthetic crowns and attaching them until the normal exfoliation time. There have been many attempts and tools used to attach the composite crowns to the treated canals of primary anterior teeth. The study evaluates endodontic treatment for destructed primary maxillary incisors with a glass fiber-reinforced post as a retentive tool to hold the esthetic composite crowns until the normal exfoliation time of primary incisors. Case Presentation. A four-year-old child attending a dental clinic complained of pain of maxillary incisors. Dental examination showed irreversible pulpitis of four maxillary incisors indicated for root canal treatment and crown placement. Endodontic treatment was carried out, and a glass fiber-reinforced post was used to get successful retention for the composite crowns. Follow-up was carried out for 3 years. The 3 crowns were retained successfully until replaced by permanent incisors. One crown fell during the treatment course. Conclusion. Retention of primary teeth is one of the challenges in pediatric dentistry. Restoration of primary decayed incisors is important for child medical, physical, and psychological conditions. A glass fiber-reinforced post and core is a strong retentive tool for composite crown retention for primary incisors. This procedure opens the door for a strong tool to retain composite crowns for a long time. The glass fiber-reinforced post and core is a strong retentive tool for composite crown retention for primary incisors.
Synthesis and Characterisation of Activated Carbon Obtained from Marula (Sclerocarya birrea) Nutshell
Authors: Mkungunugwa Tafadzwa , Manhokwe Shepherd , Chawafambira Armistice , Shumba Munyaradzi
Published: May 2021

Globally, a ninth of people use polluted water sources because an estimated 300–400 Mt of waste and 90% of sewage are discharged into water bodies from industries and developing countries, respectively. The utilisation of indigenous fruit pits in producing novel adsorbents will greatly benefit in wastewater treatment. In most underdeveloped countries, activated carbon (AC) is imported at a high cost. The study was aimed at synthesising and characterisation of AC obtained from Marula nutshell. Carbonization of organic matter from Marula nutshell was carried out at 200°C, 400°C, 500°C, and 600°C. Sulphuric (H2SO4) and phosphoric (H3PO4) acids were used as activating agents at concentrations of 20–60% (

v
/
v

). Physicochemical characteristics of the AC, such as bulk density, moisture, ash, pH, and iodine number, were analyzed using standard methods. Functional groups and total carbon content were determined using the FTIR spectroscopy and Nitrogen Carbon Sulphur (NCS) analyzer, respectively. The values of carbon yield and total carbon in activated samples with H2SO4 and H3PO4 were 32.2–93.2%, 26.9–95.8%, and 46–79%, 20.8–69.8%, respectively. The pH, ash, moisture, and bulk density of activated high carbon samples with H2SO4 ranged from 2.4–6.1, 0.65–3.49%, 1.3–8.4%, and 0.42–0.62 gcm−3, respectively. Activated high carbon samples with H3PO4 had 2.7–3.2, 11.3–29.8%, 4.7–14.6%, and 0.39–0.54 gcm−3 pH, ash, moisture, and bulk density, respectively. The synthesised AC samples with 40% H3PO4 at 500°C had the highest iodine value of 1075.7 mg/g. FTIR results showed the presence of aliphatic carboxylic acid salt, inorganic nitrate (NO3−), and phosphate groups in the synthesised AC and were not significantly different (

p
<
0.05

) from commercial AC. The untreated Marula nutshell had some aliphatic hydrocarbon (alkanes), inorganic phosphate (

PO

4

3
−

), aliphatic ester (–COO), and aliphatic carboxylic acid salt (–C(=O)O–) groups. A novel adsorbent, AC was produced from Marula nutshell with the potential to be used in water treatment.
Optical Feedback for Sensitivity Enhancement in Direct Raman Detection of Liquids
Authors: Liu Miao , Mu Yunyun , Hu Jingyun , Li Jiajun , Zhang Xinping
Published: May 2021

Detection of low-concentration molecules in liquids has been a challenge in sensing technologies. Raman spectroscopy is an effective approach for trace detection, which is in fact a “volume-excitation” and “volume-collection” technique in the analysis of liquid samples. However, for the commonly employed one-pass excitation and back-scattering detection scheme, a large portion of both the excitation laser energy and the Raman-scattering light energy is wasted without efficient reuse or collection. In this consideration, we demonstrate a broadband optical feedback scheme by a curved high-reflection mirror for both the excitation and the Raman-scattering light, so that the excitation and the forward-propagating Raman signal can be back-reflected and collected with a high efficiency. Using the “F+2f” design, where F and f are the focal lengths of the focusing lens and curved reflection mirror, respectively, we were able to not only produce two focuses of the excitation laser beam but also extend the Raman interaction by a doubled distance. For the detection of pure ethanol molecules and the R6G molecules in water with a concentration of 10−3 M, the Raman signal was enhanced by a factor of about 5.6. The optical feedback scheme and discovered optical mechanisms supply effective improvements to the Raman spectroscopic measurements on liquid samples.
Screening and Characterization of Thermostable Amylase-Producing Bacteria Isolated from Soil Samples of Afdera, Afar Region, and Molecular Detection of Amylase-Coding Gene
Authors: Yassin Semira Nureddin , Jiru Tamene Milkessa , Indracanti Meera
Published: May 2021

Studying thermostable amylase-producing bacteria in extreme environments has a crucial role to overcome different industrial challenges. Afar Region is one of the hottest and salty areas, making it the home of extremophiles. This study aimed at screening and characterizing amylase-producing bacteria isolated from soil samples of Afdera, Afar Region, and detection of their amylase-coding genes. Thus, a total of 49 bacterial isolates were obtained from the collected soil samples. Out of these, three isolates (M2, M8, and M13) were selected on the basis of diameter of the average clear zone formation and time taken to decolorize iodine solution. Based on their morphological and biochemical characteristics, the isolates were identified as genus Bacillus. PCR amplification and detection of the amylase-coding gene confirmed the presence of the amylase gene in the three bacterial isolates. Optimum amylase production time for these isolates was 48 hrs (M13 and M8) and 72 hrs (M2) corresponding to the amylase activity of 0.67 U/mL for M13, 0.74 U/mL for M8, and 0.73 U/mL for M2 with an optimum temperature of 55°C. Studies on the effect of temperature revealed that the crude enzyme had a maximum activity and stability at 75°C, 70°C, and 65°C for isolates M13, M8, and M2, respectively. Additionally, amylase produced from all isolates retained more than 66.41% of their original activity after incubating them at a temperature range from 55 to 80°C for 50 min. Optimum pH for the activity of all crude amylases was in the range from 5 to 9 with a peak activity at pH 8. Their activity decreased significantly by the presence of Zn+2 and Mg2+; however, their activity increased by the presence of Ca+2. Moreover, the three crude amylases were stable (0–3 M) with NaCl concentration. Amylases of this finding with thermophilic and halophilic characteristics offer a wide range of applications in food, brewing, textile, starch, paper, and deterrent industries. Thus, identification of these Bacillus isolates at a molecular level and purification as well as detailed characterization of the types of amylases are recommended for effective utilization in different industries.
Elevated Serum Small Dense Low-Density Lipoprotein Cholesterol May Increase the Risk and Severity of Coronary Heart Disease and Predict Cardiovascular Events in Patients with Type 2 Diabetes Mellitus
Authors: Huang Juan , Gu Jun-Xu , Bao Hui-Zhang , Li Shan-Shan , Yao Xiao-Qin , Yang Ming , Li Yang , Zhang Ai-Min , Yin Yue , Zhang Na , Jia Mei , Su Ming
Published: May 2021

Background. Coronary heart disease (CHD) is a common and severe complication in type 2 diabetes mellitus (T2DM) patients. Increased amount of circulatory small dense low-density lipoprotein cholesterol (sdLDL-C) particles is known to be a sign of dyslipidemia and can result in atherosclerosis. However, the association between serum sdLDL-C levels and CHD in T2DM patients remains unclear. Methods. A total of 3684 T2DM patients who received selective coronary angiography (CAG) were selected. For analyzing the association between sdLDL-C and CHD severity in T2DM, the patients with CHD were further divided into four subgroups according to the quartiles of sdLDL-C. A multivariate logistic regression was used for analyzing the risks and severity of CHD. A total of 3427 patients with continuous stable CHD were recruited and followed up for 5 years. Results. Serum sdLDL-C levels in the CHD group were significantly increased compared with those in the non-CHD group [0.80 (0.49) mmol/L vs. 0.70 (0.30) mmol/L,

p
<
0.001

]. The results from CHD subgroup analysis indicated that the sdLDL-C levels in patients with multiple-vessel disease and high Gensini score (GS) were significantly increased. By adjusting the confounding factors and analyzing with multiple logistic regression, we found that sdLDL-C independently correlated with the presence and severity of CHD (CHD:

OR
=
2.257

; multiple-vessel disease:

OR
=
3.288

; high GS:

OR
=
2.554

). A total of 484 major cardiovascular events (MACEs) were documented. After Kaplan-Meier analysis and chi-squared analysis, the incidence of MACEs in the high sdLDL-C group was higher than that in the low sdLDL-C group (16.04% vs. 12.25%,

p
=
0.002

). Conclusion. In T2DM patients, elevated serum sdLDL-C may increase the severity of CHD and predict cardiovascular events in the future. Therefore, serum sdLDL-C may be a potential biomarker for the surveillance of CHD in T2DM patients.