bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of differentially culturable tubercle bacteria in sputum using mycobacterial culture filtrates
Authors: Gordhan Bhavna G. , Peters Julian S. , McIvor Amanda , Machowski Edith E. , Ealand Christopher , Waja Ziyaad , Martinson Neil , Kana Bavesh D.
Published: March 2021

Rapid detection of tuberculosis (TB) infection is paramount to curb further transmission. The gold standard for this remains mycobacterial culture, however emerging evidence confirms the presence of differentially culturable tubercle bacteria (DCTB) in clinical specimens. These bacteria do not grow under standard culture conditions and require the presence of culture filtrate (CF), from axenic cultures of Mycobacterium tuberculosis (Mtb), to emerge. It has been hypothesized that molecules such as resuscitation promoting factors (Rpfs), fatty acids and cyclic-AMP (cAMP) present in CF are responsible for the growth stimulatory activity. Herein, we tested the ability of CF from the non-pathogenic bacterium Mycobacterium smegmatis (Msm) to stimulate the growth of DCTB, as this organism provides a more tractable source of CF. We also interrogated the role of Mtb Rpfs in stimulation of DCTB by creating recombinant strains of Msm that express Mtb rpf genes in various combinations. CF derived from this panel of strains was tested on sputum from individuals with drug susceptible TB prior to treatment. CF from wild type Msm did not enable detection of DCTB in a manner akin to Mtb CF preparations and whilst the addition of RpfABMtb and RpfABCDEMtb to an Msm mutant devoid of its native rpfs did improve detection of DCTB compared to the no CF control, it was not statistically different to the empty vector control. To further investigate the role of Rpfs, we compared the growth stimulatory activity of CF from Mtb, with and without Rpfs and found these to be equivalent. Next, we tested chemically diverse fatty acids and cAMP for growth stimulation and whilst some selective stimulatory effect was observed, this was not significantly higher than the media control and not comparable to CF. Together, these data indicate that the growth stimulatory effect observed with Mtb CF is most likely the result of a combination of factors. Future work aimed at identifying the nature of these growth stimulatory molecules may facilitate improvement of culture-based diagnostics for TB.
Analysis of biomolecules in cochineal dyed archaeological textiles by surface-enhanced Raman spectroscopy
Authors: Celis F. , Segura C. , Gómez-Jeria J. S. , Campos-Vallette M. , Sanchez-Cortes S.
Published: March 2021

SERS spectroscopy is successfully employed in this work to reveal different components integrating the cochineal colorant employed for dying archaeological textile samples from the Arica Region in North Chile. This analysis was done by in-situ experiments that does not imply the material (colorant and biomolecules) extraction. The spectroscopic analysis of the archaeological textiles by SERS reveals the presence of bands attributed to carminic acid and nucleobases, mainly adenine and guanine. The identification of these biomolecules was also verified in raw cochineal extract and in cochineal dyed replica wool fibers fabricated by us following ancient receipts. The effect of Al on the complexation of carminic acid and other biomolecules was also tested in order to understand the changes induced by the metal interaction on the colorant structure. This study revealed that Al can also complex biomolecules existing in the cochineal extract. In particular, guanine residue seems to interact strongly with the metal, since SERS bands of this residue are enhanced. Furthermore, a theoretical analysis on the interaction of carminic acid and a silver surface was also performed in order to better understand the interaction mechanism between carminic acid and a metal surface that leads to the final SERS spectrum. The results of the present work will be very useful in the identification of different molecules and metal complexes that may be forming part of the cochineal colorant found in archaeological materials.
Searching for small-world and scale-free behaviour in long-term historical data of a real-world power grid
Authors: Hartmann Bálint , Sugár Viktória
Published: March 2021

Since the introduction of small-world and scale-free properties, there is an ongoing discussion on how certain real-world networks fit into these network science categories. While the electrical power grid was among the most discussed examples of these real-word networks, published results are controversial, and studies usually fail to take the aspects of network evolution into consideration. Consequently, while there is a broad agreement that power grids are small-world networks and might show scale-free behaviour; although very few attempts have been made to find how these characteristics of the network are related to grid infrastructure development or other underlying phenomena. In this paper the authors use the 70-year-long historical dataset (1949–2019) of the Hungarian power grid to perform complex network analysis, which is the first attempt to evaluate small-world and scale-free properties on long-term real-world data. The results of the analysis suggest that power grids show small-world behaviour only after the introduction of multiple voltage levels. It is also demonstrated that the node distribution of the examined power grid does not show scale-free behaviour and that the scaling is stabilised around certain values after the initial phase of grid evolution.
Author Correction: Linear infrastructure habitats increase landscape-scale diversity of plants but not of flower-visiting insects
Authors: Dániel-Ferreira Juliana , Bommarco Riccardo , Wissman Jörgen , Öckinger Erik
Published: March 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
TMT-based quantitative proteome profiles reveal the memory function of a whole heart decellularized matrix for neural stem cell trans-differentiation into the cardiac lineage
Authors: Wang Changyong , Yang Xiaoning , Zhang Xiao , Liu Baijun , Liu Wei , Shen Yuan , Gao Zhongbao , Yin Qi , Wang Chunlan , Zhou Jin
Published: March 2021

Whole organ or tissue decellularized matrices are a promising scaffold for tissue engineering because they maintain the specific memory of the original organ or tissue.
Epoxy-matrix polyaniline/p-phenylenediamine-functionalised graphene oxide coatings with dual anti-corrosion and anti-fouling performance
Authors: Fazli-Shokouhi Sara , Nasirpouri Farzad , Khatamian Maasoumeh
Published: March 2021

Graphene oxide (GO), GO-functionalised usingp-phenylenediamine (PGO) and polyaniline (PANI)-PGO composites were successfully prepared for use in epoxy-matrix coatings for anti-corrosion and anti-fouling applications.
Au@mSiO2 core–shell nanoparticles loaded with fluorescent dyes: synthesis and application for imaging performance
Authors: Li Xiaorong , Shao Yutong , Lv Shibo , Tian Jiarui , Zheng Daoyuan , Song Jitao , Song Fengling
Published: March 2021

A simple method for preparing and modifying Au@mSiO2 core–shell nanoparticles was proposed, achieving fluorescence and TEM dual mode imaging.
Palladium oxide-decorated mesoporous silica on graphene oxide nanosheets as a heterogeneous catalyst for the synthesis of β-substituted indole derivatives
Authors: Sah Digvijay , Shabir Javaid , Surabhi  , Gupta Padmini , Mozumdar Subho
Published: March 2021

A PdO NPs immobilized mesoporous silica over GO sheets has been synthesized and utilized for the synthesis of β-substituted indole derivatives. An efficient catalytic activity and recyclability are the main features of this protocol.
Endohedral cluster intermetallic superconductors: at the frontier between chemistry and physics
Authors: Verchenko Valeriy Yu. , Shevelkov Andrei V.
Published: March 2021

Intermetallic frameworks built from endohedral clusters of p-metals demonstrate unusual structural flexibility and nontrivial superconducting properties.
Catalytic enantioselective intramolecular Tishchenko reaction of meso-dialdehyde: synthesis of (S)-cedarmycins
Authors: Ismiyarto  , Kishi Nobuki , Adachi Yuki , Jiang Rui , Doi Takahiro , Zhou Da-Yang , Asano Kaori , Obora Yasushi , Suzuki Takayoshi , Sasai Hiroaki , Suzuki Takeyuki
Published: March 2021

The first successful example of a catalytic enantioselective intramolecular Tishchenko reaction of a meso-dialdehyde in the presence of a chiral iridium complex is described.
Catalytically active and thermally stable core–shell gold–silica nanorods for CO oxidation
Authors: Chen Yidong , Lerch Sarah , Say Zafer , Tiburski Christopher , Langhammer Christoph , Moth-Poulsen Kasper
Published: March 2021

Gold nanorods stabilized with mesoporous silica shells are characterized and used as the catalyst for a model CO oxidation reaction to counter the costly sintering phenomena found in many industrial nanoparticle catalysts.
Evaluating the effects of hydrophobic and cationic residues on antimicrobial peptide self-assembly
Authors: Cao Fengyi , Ma Gangqing , Song Meng , Zhu Genxing , Mei Lin , Qin Qi
Published: March 2021

Four PAF26 peptide derivatives were used to study the effects of hydrophobic and cationic residues on self-assembly behaviours. It was found that peptide with different number of hydrophobic and cationic residues had different secondary conformation and microstructure.
Synergistic enhancement of the oxygen evolution reaction by MoSx and sulphate on amorphous polymetallic oxide nanosheets
Authors: Gan Yonghao , Dai Xiaoping , Cui Meilin , Zhao Huihui , Nie Fei , Ren Ziteng , Yin Xueli , Yang Zhaohui , Wu Baoqiang , Cao Yihua , Zhang Xin
Published: March 2021

Amorphous polymetallic oxides containing MoSx and SO42− are proposed to enhance OER performance due to the acceleration of the *OH → *O + *H by MoSx, optimization of *OOH deprotonation by sulfate, polymetallic interaction and abundant oxygen vacancies.
All-solid-state direct Z-scheme NiTiO3/Cd0.5Zn0.5S heterostructures for photocatalytic hydrogen evolution with visible light
Authors: Li Bifang , Wang Wenjing , Zhao Jiwu , Wang Zhaoyu , Su Bo , Hou Yidong , Ding Zhengxin , Ong Wee-Jun , Wang Sibo
Published: March 2021

All-solid-state direct NiTiO3/Cd0.5Zn0.5S Z-scheme heterostructures enabled the visible-light hydrogen evolution at an optimal H2-releasing rate of 26.45 mmol h−1 g−1.
Tuning luminescence from NIR-I to NIR-II in Cr3+-doped olivine phosphors for nondestructive analysis
Authors: Cai Hao , Liu Shengqiang , Song Zhen , Liu Quanlin
Published: March 2021

We report a series of Cr3+-doped olivine phosphors with tunable luminescence from 940 to 1100 nm. They have promising applications in the field of food processing for both qualitative identification and quantitative analysis.
Teachers and Language Outcomes of Young Bilinguals: A Scoping Review
Authors: Ramírez Rica , Huang Becky H. , Palomin Amanda , McCarty Laurenne
Published: March 2021

Purpose

The present scoping review seeks to fill an important need in the bilingual research and education community by analyzing the recent research literature on how teacher factors potentially influence young bilingual children's language outcomes. The research aims are twofold: synthesize the research findings on teacher factors that influence bilinguals' language development, and identify gaps in the literature to determine future research directions.

Method

The search parameters used in this review included peer-reviewed journal articles from 2000 to 2019 in order to synthesize the most recent empirical work on this topic, a focus on typically developing bilinguals from the age of 3 to 8 years, and research designs that included case studies, descriptive, cross-sectional, quasi-experimental, experimental, longitudinal, mixed methods, and qualitative methods.

Results

A search of major databases for studies on young bilinguals and teachers between 2000 and 2019 combined with multiple levels of screening and review yielded 21 peer-reviewed articles. Four major themes emerged: (a) teacher characteristics, (b) teacher quality, (c) teacher talk, and (d) teacher emotional support.

Conclusions

Overall, the results of this synthesis suggest that teachers do in fact influence the language development of young bilinguals. Teacher talk and teacher quality were found to be the two themes that were of most interest in the research community, and the results generally supported the positive effect of teacher quality and teacher talk on language outcomes among bilinguals, with some variability. This review has important implications for teacher training and education in an effort to better serve the growing population of bilingual children.
Cluster optimization in wireless sensor network based on optimized Artificial Bee Colony algorithm
Authors: S. R Deepa , D Rekha
Published: March 2021

Wireless sensor networks (WSNs) have emerged as a potential research area owing to their wide range of applicability in various fields. Critical application areas of WSN include defence and military surveillance, weather monitoring, health care monitoring, and Internet of Things. Extensive research efforts have been made to improve energy and data delivery performance in WSN with different bio‐inspired optimized clustering methodologies such as particle swarm optimization (PSO), and the bacterial foraging algorithm for optimization (BFAO). However, most constrained solutions are limited to data aggregation performance and enhance the energy efficiency of the network to some extent. Therefore, balancing energy and data delivery performance to a greater extent is crucial because of design limitations imposed on existing hierarchical solutions. This article introduces a novel clustering paradigm, namely optimal clustering using the Artificial Bee Colony (OCABC) algorithm, which improves energy efficiency based on a simplified and robust ABC algorithm. The central idea is to increase the network lifetime of the WSN by optimizing the cluster formation process. The implemented structured module of OCABC attempts to overcome challenges encountered in existing baselines. The extensive numerical analysis with respect to significant performance parameters assists in benchmarking the OCABC compared with the PSO and BFAO.
Short-term outcomes of total knee arthroplasty performed with and without a tourniquet
Authors: Grigoras Mihai , Boughton Oliver , Cleary May , McKenna Paul , Rowan Fiachra E.
Published: March 2021

Introduction: Not using a tourniquet could improve early postoperative pain, range of motion (ROM), length of stay (LOS), and thromboembolic risk in patients undergoing total knee arthroplasty (TKA). Our aim was to compare these factors, intraoperative blood loss, and gender-related outcomes in patients undergoing primary TKA with or without a tourniquet. Methods: We performed a retrospective cohort study of 97 patients undergoing TKA with or without tourniquet from 2018 to 2020. Revisions and bilateral TKAs were excluded. Blood loss was estimated using a validated formula. Postoperative pain was tested using the visual analogue scale (VAS). ROM and quadriceps lag were assessed by a physiotherapist on a postoperative day 2 and discharge. The index of suspicion for a thromboembolic event was defined as the number of embolic-related investigations ordered in the first 6 months post-surgery. The Shapiro–Wilk test was used to assess the distribution of the data, Mann–Whitney for the continuous variables, and Fischer’s test for the categorical ones. Results and Discussion: There was a significant difference in blood loss. The non-tourniquet group lost on average 32% more blood (1291 mL vs. 878 mL, p<0.001 two-tailed). We found no difference in pain, ROM, LOS, and quadriceps lag on day 2 and at discharge. There was one thromboembolic event in the tourniquet group, but the thromboembolic index of suspicion did not differ (p=0.53). With tourniquet use, women had a significantly lower day 2 maximum flexion than men (71.56° vs. 84.67°, p=0.02). In this retrospective cohort study, the results suggest that tourniquet use is associated with lower blood loss and similar postoperative pain, range of motion, quadriceps lag, length of stay, and thromboembolic risk. There might be some differences between how men and women tolerate a tourniquet, with women having worse short-term outcomes compared to men.
Sexueller Missbrauch von Minderjährigen
Authors: John Anne-Christin
Published: March 2021

Wenn Kinder oder Jugendliche sexuell missbraucht werden, leiden sie meist ihr Leben lang unter den psychischen Folgen. Da die Symptome und Auswirkungen bei jedem Minderjährigen unterschiedlich sein können, müssen Behandlungsansätze individuell angepasst werden. Welche psychischen Konsequenzen ein sexueller Missbrauch haben kann und wie sie mithilfe der Strukturierten Trauma-Intervention therapiert werden können, schildert unsere Autorin.
Forensische Nachsorge: In kleinen Schritten zum Ziel
Authors: Diemer Annette
Published: March 2021

Psychisch erkrankte Straftäter wieder in die Gesellschaft einzugliedern, ist eine hochkomplexe Aufgabe. Im Fokus steht dabei immer die Frage, ob sich die Patienten in einem Setting befinden, das sie mit hoher Wahrscheinlichkeit vor neuen Straftaten schützt. Damit das gelingt, arbeitet in der Forensischen Ambulanz Wiesloch ein multiprofessionelles Team eng zusammen. Patienten erhalten hier eine qualifizierte Behandlung und ein individuelles Risikomanagement, zudem werden ihr Risiko und ihre Prognose kontinuierlich im konkreten Lebensumfeld eingeschätzt.
Weakly nonlinear instability of annular viscous sheets
Authors: Xie Luo , Ye Han-Yu , Ren Feng , Hu Hai-Bao
Published: March 2021

A second-order perturbation analysis has been performed on the nonlinear temporal instability of para-sinuous disturbances on annular viscous sheets moving in an inviscid stationary gas medium. The mathematical expressions of second-order interface disturbances, velocity, and pressure have been derived. The nonlinear instability of annular viscous sheets has several characteristics which differ from that of planar viscous sheets: (1) both the first-order interface disturbances and the second-order interface disturbances contribute to breakup; (2) the zero-wavenumber component of interface disturbances in the second-order solution is nonzero; (3) the second-order interface disturbance is para-varicose in most cases, but para-sinuous for some cases. As with planar viscous sheets, it was found that viscosity plays a dual role in the nonlinear instability of annular viscous sheets. However, with the decrease in the ratio of inner radius to sheet thickness, the interval between the upper and the lower critical Reynolds numbers shrinks, and when the ratio of inner radius to sheet thickness is less than a certain value, the dual effect of viscosity vanishes.
Rescue of codon-pair deoptimized respiratory syncytial virus by the emergence of genomes with very large internal deletions that complemented replication
Authors: Le Nouën Cyril , McCarty Thomas , Yang Lijuan , Brown Michael , Wimmer Eckard , Collins Peter L. , Buchholz Ursula J.
Published: March 2021

Significance

Synonymous recoding of viral genomes by codon-pair deoptimization (CPD) provides live-attenuated vaccine candidates expected to be genetically stable. However, their actual genetic stability is largely unknown. Under selective pressure, a highly attenuated human respiratory syncytial virus bearing CPD G and F ORFs (called Min B) generated abundant subpopulations of genomes containing large internal deletions (LD genomes). These LD genomes contained the CPD F gene in the first or second promoter-proximal position. This provided increased expression of the F protein, which rescued Min B replication. Thus, defective genomes were specifically selected to complement and rescue the replication of a CPD RNA virus. This study describes a previously unknown mechanism of adaptation of negative-strand RNA viruses.
“Don’t go getting into trouble again!”
Authors: Fanego Teresa
Published: March 2021

Building on Goldberg’s (2006: 52) observation regarding the existence of “a family of related constructions in English” centred around the verbgo, this article explores the history of the construction exemplified in the title (“Don’t go getting into trouble again!”) and its relation to other members of the network ofgo-constructions. The analysis, conducted using three large corpora, shows that theGoVPingconstruction emerges from two source constructions (one with an –ingparticiple following the verbgoand the other with an infinitive) which exhibit overlap in terms of certain aspects of their form and meaning. From its earliest attestations in the eighteenth century, theGoVPingconstruction has grown increasingly more interpersonal, and has become conventionalized as a marker of admonitive mood (Bybee et al. 1994: 321) which serves to dissuade or limit the performance of an activity that is apprehended as undesirable and counter-normative.
Substances and Your Senses: The Sensory Patterns of Young People within an Alcohol and Drug Treatment Service
Authors: Kelly John , Meredith Pamela Joy , Taylor Michelle , Morphett Amanda , Wilson Hollie
Published: March 2021

Background

Substance use disorders (SUD) and trauma histories in adults have been linked with sensory processing patterns that are significantly different from the general population. Nevertheless, no studies have investigated sensory patterns, or the variables with which they are related, in youth with SUD. This study aimed to compare sensory patterns of this sample with normative data and consider associations between sensory patterns and: substance use, trauma, quality-of-life, mental and physical health.

Methods

A cross-sectional quantitative research design was employed with a sample of 87 young people (mean age = 20.8 years) with SUD voluntarily attending a specialist youth outpatient alcohol and other drug (AOD) service. For participants, the Adolescent Adult Sensory Profile was added to measures routinely collected at the service.

Results

Participants’ sensory processing patterns for low registration, sensory sensitivity, and sensation avoiding were significantly higher than the normative population, while sensation seeking was both lower and higher. Ninety-one percent reported atypical scores on one or more sensory patterns. High rates of probable Post-Traumatic-Stress-Disorder (PTSD), psychological distress, and low quality-of-life were also reported, which were meaningfully related with sensory patterns.

Conclusion

Young people reported complex combinations of sensory processing patterns, with comorbid probable PTSD, psychological distress, and low quality-of-life. Findings reflect studies with adult AOD, trauma, and other clinical conditions, and highlight the potential value of screening for sensory patterns and applying transdiagnostic approaches which simultaneously address substance use, mental health, trauma and sensory needs to optimize outcomes for young people with SUD.
Immune-mediated vincristine-induced neuropathy: Unlocking therapies
Authors: Savelieff Masha G. , Feldman Eva L.
Published: March 2021

Vincristine-induced peripheral neuropathy (VIPN) is a prevalent and painful complication in cancer patients that lacks effective treatments. In this issue of JEM, Starobova et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20201452) report that VIPN is driven by innate immune system activation, a discovery that unlocks immunotherapies as potential treatments.
Transfer of learning in a mathematical methods in physics course for undergraduate students of physics
Authors: Arbabifar Fatemeh
Published: March 2021

This study examined the effect of transfer of learning on undergraduate students of physics education. Because mathematical methods are valuable for presenting and solving physics problems, students of physics must learn to use their knowledge of mathematics in a physical context rather than struggling with complicated mathematical problems. This study sought to determine whether or not practice with physics problems by a physics instructor for the course could help the undergraduate students transfer their mathematics knowledge to a physics context. To do this, the experimental and control groups of physics education students were provided with an exam sheet and interviewed about difficulties after passing the course taught by either a physics or mathematics instructor. After completion of the course, the student responses to the exam and interviews were analyzed qualitatively. It was concluded that simply learning mathematics by the control group suppressed their initiative and caused them to resist completing the physics problems. The experimental group felt capable of attempting this kind of problem, but lacked additional factors that prevented them from producing complete solutions.
Modulation of electronic and optical properties of line defected armchair MoS2 nanoribbon by vacancy passivation
Authors: Gholami Rudi Somayeh , Soleimani-Amiri Samaneh
Published: March 2021

In this study, the density functional theory (DFT) is used to investigate the effects of passivating line sulfur vacancies by non-metal species (C, N, O, F, OH and NH2) in armchair MoS2 nanoribbon (AMoS2NR) on its structural, electrical and optical properties. Calculated binding energies show that passivation of line vacancies by oxygen atoms leads to the most stable structures. Electronic calculations show that presence of single line vacancies decreases the bandgap of 0.68 eV in perfect AMoS2NR to 0.62 eV in single line vacant AMoS2NR (SV) and substituting the vacancies with carbon and oxygen (C-SV and O-SV) returns the bandgap to its initial value. It is also shown that passivation of SV with NH2 leads to a semiconductor with a small bandgap of 0.08 eV. However, substituting the vacancies of SV with N, F and OH results in metallic structures. In the case of double line vacant AMoS2NR (DV), the bandgap reduces significantly (0.38 eV) with respect to its perfect counterpart. Similar to what happened in SV, passivating DV with C and O again increases the bandgap to the bandgap of the perfect structure. Furthermore, N-, F-, OH- and NH2-DV show metallic behavior. In addition, we use total, projected and local density of states (TDOS, PDOS and LDOS) analysis to reveal the role of different atoms in different positions on the electronic properties of defective AMoS2NRs. In order to investigate the effect of passivation on the optical properties of defective AMoS2NRs we present the real and imaginary parts of dielectric function spectra. Our results suggest that passivation of line vacancies by different atoms can efficiently tune the absorption of AMoS2NR and open a new path to obtain MoS2-based optoelectronic devices.
Terrace-confined guided growth of high-density ultrathin silicon nanowire array for large area electronics
Authors: Xu Shun , Hu Ruijin , Wang Junzhuan , Li Zheyang , Xu Jun , Chen Kunji , Yu Linwei
Published: March 2021

Ultrathin silicon nanowires (SiNWs) are ideal 1D channels to construct high performance nanoelectronics and sensors. We here report on a high-density catalytic growth of orderly ultrathin SiNWs, with diameter down to

D

nw

=
27
±
2

nm

and narrow NW-to-NW spacing of only

S

nw

 ∼80 nm, without the use of high-resolution lithography. This has been accomplished via a terrace-confined strategy, where tiny indium (In) droplets move on sidewall terraces to absorb precoated amorphous Si layer as precursor and produce self-aligned SiNW array. It is found that, under proper parameter control, a tighter terrace-step confinement can help to scale the dimensions of the SiNW array down to the extremes that have not been reported before, while maintaining still a stable guiding growth over complex contours. Prototype SiNW field effect transistors demonstrate a high I
on/I
off current ratio ∼107, low leakage current of ∼0.3 pA and steep subthreshold swing of 220 mV dec−1. These results highlight the unexplored potential of catalytic growth in advanced nanostructure fabrication that is highly relevant for scalable SiNW logic and sensor applications.
3-bit multilevel operation with accurate programming scheme in TiO
x
/Al2O3 memristor crossbar array for quantized neuromorphic system
Authors: Kim Tae-Hyeon , Lee Jaewoong , Kim Sungjoon , Park Jinwoo , Park Byung-Gook , Kim Hyungjin
Published: March 2021

As interest in artificial intelligence (AI) and relevant hardware technologies has been developed rapidly, algorithms and network structures have become significantly complicated, causing serious power consumption issues because an enormous amount of computation is required. Neuromorphic computing, a hardware AI technology with memory devices, has emerged to solve this problem. For this application, multilevel operations of synaptic devices are important to imitate floating point weight values in software AI technologies. Furthermore, weight transfer methods to desired weight targets must be arranged for off-chip training. From this point of view, we fabricate 32 × 32 memristor crossbar array and verify the 3-bit multilevel operations. The programming accuracy is verified for 3-bit quantized levels by applying a reset-voltage-control programming scheme to the fabricated TiO
x
/Al2O3-based memristor array. After that, a synapse composed of two differential memristors and a fully-connected neural network for modified national institute of standards and technology (MNIST) pattern recognition are constructed. The trained weights are post-training quantized in consideration of the 3-bit characteristics of the memristor. Finally, the effect of programming error on classification accuracy is verified based on the measured data, and we obtained 98.12% classification accuracy for MNIST data with the programming accuracy of 1.79% root-mean-square-error. These results imply that the proposed reset-voltage-control programming scheme can be utilized for a precise tuning, and expected to contribute for the development of a neuromorphic system capable of highly precise weight transfer.
Cosmic shear power spectra in practice
Authors: Nicola Andrina , García-García Carlos , Alonso David , Dunkley Jo , Ferreira Pedro G. , Slosar Anže , Spergel David N.
Published: March 2021

Cosmic shear is one of the most powerful probes of Dark
Energy, targeted by several current and future galaxy
surveys. Lensing shear, however, is only sampled at the positions of
galaxies with measured shapes in the catalog, making its associated
sky window function one of the most complicated amongst all
projected cosmological probes of inhomogeneities, as well as giving
rise to inhomogeneous noise. Partly for this reason, cosmic shear
analyses have been mostly carried out in real-space, making use of
correlation functions, as opposed to Fourier-space power
spectra. Since the use of power spectra can yield complementary
information and has numerical advantages over real-space pipelines,
it is important to develop a complete formalism describing the
standard unbiased power spectrum estimators as well as their
associated uncertainties. Building on previous work, this paper
contains a study of the main complications associated with
estimating and interpreting shear power spectra, and presents fast
and accurate methods to estimate two key quantities needed for their
practical usage: the noise bias and the Gaussian covariance matrix,
fully accounting for survey geometry, with some of these results
also applicable to other cosmological probes. We demonstrate the
performance of these methods by applying them to the latest public
data releases of the Hyper Suprime-Cam and the Dark Energy Survey
collaborations, quantifying the presence of systematics in our
measurements and the validity of the covariance matrix estimate. We
make the resulting power spectra, covariance matrices, null tests
and all associated data necessary for a full cosmological analysis
publicly available.
Silicone encapsulation of thin-film SiO
x
, SiO
x
N
y
and SiC for modern electronic medical implants: a comparative long-term ageing study
Authors: Lamont C , Grego T , Nanbakhsh K , Shah Idil A , Giagka V , Vanhoestenberghe A , Cogan S , Donaldson N
Published: March 2021

Objective. Ensuring the longevity of implantable devices is critical for their clinical usefulness. This is commonly achieved by hermetically sealing the sensitive electronics in a water impermeable housing, however, this method limits miniaturisation. Alternatively, silicone encapsulation has demonstrated long-term protection of implanted thick-film electronic devices. However, much of the current conformal packaging research is focused on more rigid coatings, such as parylene, liquid crystal polymers and novel inorganic layers. Here, we consider the potential of silicone to protect implants using thin-film technology with features 33 times smaller than thick-film counterparts. Approach. Aluminium interdigitated comb structures under plasma-enhanced chemical vapour deposited passivation (SiO
x
, SiO
x
N
y
, SiO
x
N
y
+ SiC) were encapsulated in medical grade silicones, with a total of six passivation/silicone combinations. Samples were aged in phosphate-buffered saline at 67 ∘C for up to 694 days under a continuous ±5 V biphasic waveform. Periodic electrochemical impedance spectroscopy measurements monitored for leakage currents and degradation of the metal traces. Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, focused-ion-beam and scanning-electron- microscopy were employed to determine any encapsulation material changes. Main results. No silicone delamination, passivation dissolution, or metal corrosion was observed during ageing. Impedances greater than 100 GΩ were maintained between the aluminium tracks for silicone encapsulation over SiO
x
N
y
and SiC passivations. For these samples the only observed failure mode was open-circuit wire bonds. In contrast, progressive hydration of the SiO
x
caused its resistance to decrease by an order of magnitude. Significance. These results demonstrate silicone encapsulation offers excellent protection to thin-film conducting tracks when combined with appropriate inorganic thin films. This conclusion corresponds to previous reliability studies of silicone encapsulation in aqueous environments, but with a larger sample size. Therefore, we believe silicone encapsulation to be a realistic means of providing long-term protection for the circuits of implanted electronic medical devices.
Validity of models for Dreicer generation of runaway electrons in dynamic scenarios
Authors: Olasz S. , Embreus O. , Hoppe M. , Aradi M. , Por D. , Jonsson T. , Yadikin D. , Pokol G.I. , EU-IM Team
Published: March 2021

Runaway electron modelling efforts are motivated by the risk these energetic particles pose to large fusion devices. The sophisticated kinetic models can capture most features of the runaway electron generation but have high computational costs, which can be avoided by using computationally cheaper reduced kinetic codes. This paper compares the reduced kinetic and kinetic models to determine when the former solvers, based on analytical calculations assuming quasi-stationarity, can be used. The Dreicer generation rate is calculated by two different solvers in parallel in a workflow developed in the European integrated modelling framework, and this is complemented by calculations of a third code that is not yet integrated into the framework. Runaway Fluid, a reduced kinetic code, NORSE, a kinetic code using non-linear collision operator, and DREAM, a linearized Fokker–Planck solver, are used to investigate the effect of a dynamic change in the electric field for different plasma scenarios spanning across the whole tokamak-relevant range. We find that on time scales shorter than or comparable to the electron–electron collision time at the critical velocity for runaway electron generation, kinetic effects not captured by reduced kinetic models play an important role. This characteristic time scale is easy to calculate and can reliably be used to determine whether there is a need for kinetic modelling or cheaper reduced kinetic codes are expected to deliver sufficiently accurate results. This criterion can be automated, and thus it can be of great benefit for the comprehensive self-consistent modelling frameworks that are attempting to simulate complex events such as tokamak start-up or disruptions.
Diffusive epidemic process in 3D: a two-species reaction–diffusion phase transition
Authors: Argolo C , Tenório V , Albuquerque S S
Published: March 2021

By the use of Monte Carlo simulation we study the critical behavior of a three-dimensional stochastic lattice model describing a diffusive epidemic propagation process. In this model, healthy (A) and sick (B) individuals diffuse on the lattice with diffusion constants d

A
and d

B
, respectively, and undergo reactions B → A and A + B → 2B. We determine the absorbing phase transition between a steady reactive state and a vacuum state. We obtained the order parameter, order parameter fluctuations, correlation length and their critical exponents by the use of steady state and short-time dynamics simulations. We studied three different diffusion regimes: the case of species A diffusing much slower than species B (d

A
≪ d

B
), the case of species with equal diffusion constants (d

A
= d

B
) and the case of species A diffusing much faster than species B (d

A
≫ d

B
). We found only second order transition for all three cases. We did not identify any signal of first order transition for the case d

A
> d

B
as predicted by field theory in first order approximation.
Performance of Undergraduate Students To Deal with STEM (Science, Technology, Engineering and Mathematics) Based Problems
Authors: Lubis A , Nasution AA , Hia Y. , Ritonga A
Published: March 2021

The type of research carried out in this article is descriptive which aims to provide an overview of students’ high-level thinking skills in solving STEM-based problems, especially Medan State University. The subjects in this study were 45 students in the first semester of the mathematics education study program. Data collection in this study was carried out by giving a pretest to students with 15 minutes and interviews. Interviews were conducted with the aim of obtaining information about how students solve the problems presented. The results of the pretest and interviews were used as material to answer the main problem in this study. In this case, the research findings suggest that the initial abilities of students generally have not been able to help them solve the STEM problems presented to them. In solving the problems given, some students tend to use trial and error methods, while others use descriptions in words or pictures.
The Mathematics Learning using Geogebra Software to Improve Students’ CreativeThinking Ability
Authors: Romaito Pinta , Safitri Islamiani , Sarida Hotna , Nisah Hairun , Uswatun  , Hasanah  , Apriani Dede , Afsari Siska , Dwichanda Olivia , Lucky Yossy
Published: March 2021

Creative thinking in mathematics learning is a form of thinking that has received less attention in formal education until now. Creative thinking can be improved through special modifications in mathematics learning, one of which is by using Geogebra Software. This study aims to determine students’ creative thinking skills in mathematics learning with Geogebra software. This research uses quantitative methods with Quasy Experimental Design. The subjects of this study were students of class VIII SMP N 1 Pulau Rakyat with a population of 184 students. The samples in this study were class VIII-3 as the experimental class and class VIII-5 as the control class. The data analysis technique used the normality test with the Shapiro-Wilk test and the homogeneity test with the Levene test. Followed by testing the hypothesis that is using the independent sample t-test t-test. Based on the results of the analysis and discussion of the research data, it is found that the creative thinking ability of students whose learning process uses mathematics learning with Geogebra Software is higher than those using conventional learning models. Students with mathematics learning treatment with Geogebra Software have better creative thinking skills than students with learning treatment using conventional learning models.
Effect of Giving Beetroot Juice During Submaximal Exercise Against Muscle Damage
Authors: Sinaga F A , Sinaga R N , Manalu N
Published: March 2021

Strenuous physical activity causes muscle damage marked by an increase in C-reactive protein (CRP) concentrations. Muscle damage caused by physical activity can be prevented or reduced by giving antioxidants and anti-inflammatory. It is known that beetroot (Beta Vulgaris L) has antioxidant and anti-inflammatory effects. The purpose of this study was to determine the effect of giving beet juice during submaximal exercise on concentrations of C - reactive protein (CRP). This type of research is an experimental study with a randomized control group pretest-posttest design. The research was conducted at the physiology laboratory of Departement of Sports Science Faculty Universitas Negeri Medan and the integrated Laboratory of the Faculty of Medicine at University of Sumatera Utara. The study used 20 futsal athletes who met the criteria. Furthermore, the sample was divided into 2 groups (experiment = 10, control = 10). The pre-test was done by checking the CRP concentrations prior to submaximal physical exercise. During one month of sub-maximal exercise program with a frequency of 3 times a week with an intensity of 80-90%, the experimental group was given 300 ml of beetroot juice one hour before submaximal exercise, while the control group was given a placebo drink. Measurement of research variables was carried out again immediately after submaximal exercise for one month. The results showed that beetroot juice supplementation at a dose of 300 ml/day in submaximal exercise significantly reduced CRP levels compared to the control group (18.00 ± 5.65 mg/L VS 74.66 ± 23.85 mg/L; p = 0.000). In conclusion, giving beetroot juice during training for one month can reduce the CRP levels that are increased in submaximal physical exercise in athletes. The decrease in CRP levels is due to the antioxidant content found in beetroot juice.
The Design of Evaluation Model Towards The Public-Service-Agency Financial Management System at Medan State University
Authors: Mansyur A , Gultom S , Ritonga W , Darwin  , Nasution A A
Published: March 2021

The issuance of Indonesian finance minister’s decree, No. 362/KMK.05/2018 about the designation of Medan State University as government institution that applies financial management system of public service agency, requires it to have transparant, accountable and well-organized performance evaluation model. The problem that arises in carrying out the evaluation function is the unavailability of performance evaluation model and instruments that can be used to enroll the evaluation process. Thus, this paper attempts to develop a performance evaluation model at Medan State University in achieving its vision and missions. The procedures of this study involve writing research proposal, identification of need analysis, mapping the evaluation model, development, validation, implementation, data processing, and writing report. This study yields a valid model and instruments that can be implemented as a supervisory system to the academic activites at Unimed.
Characterization of Modified Fe-Cu Nanoparticle Activated Carbon Derived of Oil Palm Empty Bunches
Authors: Zubir M , Muchtar Z , Syahputra R A , Sudarma T F , Nasution H I , Lubis R A F , Fadillah L , Sandi K
Published: March 2021

We prepared activated carbon from empty oil palm bunches by modifying the metal (Fe and Cu) in the structure of the activated carbon. Empty oil palm bunches obtained in Padang Bulan, Medan, North Sumatera and after washed, it mashed then heated at 500 °C for 1 minutes. For modification, activated carbon was dissolved in a 0.1 M solution of Fe(NO3)2 and Cu(NO3)2 which is heated at 60 oC for 3 hours. Activated carbon without and with modification was then characterized using XRD and SEM / EDX. The XRD results showed slighly change after modification with new peaks appearing and missing peaks. SEM images also show that the activated carbon before modification is irregular in shape, while the activated carbon after modification is more regular and homogeneous. The presence of Fe and Cu on the modified activated carbon is also evidenced by the EDX image, which shows the presence of Fe and Cu peaks when compared to activated carbon before modification which does not show the presence of Fe and Cu metals. It successful to modified Fe and Cu inside the activated carbon of empty oil palm bunches which consider to improve their adsorption properties.
Comparative Study on Au-Ag composition in Lithium Zinc Calcium Fluroborate Glasses: Nonlinear Optics Perspective
Authors: Abhiram J , Rajaramakrishna R. , Rajashekara K M , Jagannath G , Kaewkhao J. , Rajagukguk J.
Published: March 2021

20Li2O-15CaF2-20ZnO-45B2O3- 0.XAu-(0.5-X) Ag, (where X= 0.2, 0.3) glasses were prepared by the conventional melt quench technique and coded as 2G3S and 3G2S respectively. The idea of this current work is to check the compositional dependence on the gold and silver nanoparticles in the glass. The XRD results confirmed presence of Au-Ag (111) peak at 38.11. The Infrared spectral study confirms the presence of borate segments. The UV Visible Spectroscopic studies confirms the presence of surface plasmon resonance shoulder peak for Ag nanoparticles around 490nm and 509 nm for glass 2G3S and 3G2S which had overlapped with SPR resonance peak of Au around 603 nm for glass 2G3S and around 559nm for glass 3G2S. The nonlinear optical properties were characterized using Z-Scan experimental technique for these glasses and it suggests the Glass 3G2S exhibited better nonlinear refractive index and nonlinear absorption coefficient compared to Glass 2G3S
The Effectiveness of Stem-Oriented Project and Mini-Research Teaching Materials in Improving Student Learning Outcomes at SMP 37 Medan
Authors: Simatupang H , Hardinata A , Ningsih W , Dhani F.R , Josephin A.A , Lismayadi
Published: March 2021

Several STEM-oriented project and mini research teaching materials created by undergraduate students were utilized in schools as a contribution of the campus to the school. This study aims to determine the effectiveness of STEM-oriented projects and mini-research teaching materials in improving the learning outcomes of science students at SMP Negeri 37 Medan. The research approach used in this study is a development research model which refers to Thiagarajan, the 4D model. The validation of the teaching materials was carried out by content-related experts, education experts and the science teacher. The effectiveness of the teaching materials was then explored in Grade 7 students of SMP Negeri 37 Medan bydistributing pre-test and post-test as data for the analysis of N-gain calculations. The results showed that the teaching materials were very feasible as accordance to the answer of the content expert; feasible as stated by the education expert; and very feasible as mentioned by the science teacher. Additionally, the students’ responses were very good and the N-gain test result was obtained at 0.5 which is categorized within the “medium” category at the distribution stage. This indicated that the implementation of STEM-oriented project and mini research teaching materials by undergraduate science students is effective in improving the learning outcomes of Grade 7 students in SMP Negeri 37 Medan in the academic year of2020/2021.