bluuebunny/crossref_metadata_2025 huggingface dataset:
Spin state of a single-molecule magnet (SMM) creating long-range ordering on ferromagnetic layers of a magnetic tunnel junction – a Monte Carlo study
Authors: Grizzle Andrew , D'Angelo Christopher , Martínez-Lillo José , Tyagi Pawan
Published: September 2021

Paramagnetic single-molecule magnets (SMMs) interacting with the ferromagnetic electrodes of a magnetic tunnel junction (MTJ) produce new molecular spintronics testbed and highly ordered magnetic metamaterial promising for room temperature.
Tuning the charge of polyelectrolyte complex membranes preparedviaaqueous phase separation
Authors: Durmaz Elif Nur , Willott Joshua D. , Mizan Md Mizanul Haque , de Vos Wiebe M.
Published: September 2021

Positively and negatively charged membranes are obtained by simply changing the mixing ratio of the polyelectrolytes in a fully aqueous preparation approach. This leads to selective retention of asymmetric salts and a new membrane tuning parameter.
Synthesis, characterization and electro-conducting study of isomeric polythiophene
Authors: Kumar Devendra , Tiwari Rudramani , Verma Dipendra Kumar , Yadav Shashikant , Adhikary Pubali , Krishnamoorthi S.
Published: September 2021

Herein we have reported for the first time a one-pot, one step methodology to synthesize isomeric polythiophene (IPTh) possessing 2,2, 2,4 and 5,4 linkages.
Cyclic stability of supercapacitors: materials, energy storage mechanism, test methods, and device
Authors: Wu Qianghong , He Tianqi , Zhang Yikai , Zhang Junlei , Wang Zhijun , Liu Ying , Zhao Lei , Wu Youzhi , Ran Fen
Published: September 2021

Supercapacitors, also known as electrochemical capacitors, have attracted more and more attention in recent decades due to their advantages of higher power density and long cycle life.
Data visualization with the programming language R
Authors: Brennan Paul
Published: September 2021

Data visualization is an extremely valuable skill in science, finance and journalism. Learning to program will help reproducible data analysis and will increase the different types of visualization that can be generated. The statistical programming language R is a very useful programming language. The R community is friendly, supportive and very diverse including students, academics, health scientists, journalists and professional data scientists. An experience of R or another programming language such as Python or JavaScript will improve your science and your employment opportunities in and outside of research. Programming is a useful skill in education, finance, journalism and other areas too.
Large gaps and high accretion rates in photoevaporative transition disks with a dead zone
Authors: Gárate Matías , Delage Timmy N. , Stadler Jochen , Pinilla Paola , Birnstiel Til , Stammler Sebastian Markus , Picogna Giovanni , Ercolano Barbara , Franz Raphael , Lenz Christian
Published: September 2021

Context. Observations of young stars hosting transition disks show that several of them have high accretion rates, despite their disks presenting extended cavities in their dust component. This represents a challenge for theoretical models, which struggle to reproduce both features simultaneously.

Aims. We aim to explore if a disk evolution model, including a dead zone and disk dispersal by X-ray photoevaporation, can explain the high accretion rates and large gaps (or cavities) measured in transition disks.

Methods. We implemented a dead zone turbulence profile and a photoevaporative mass-loss profile into numerical simulations of gas and dust. We performed a population synthesis study of the gas component and obtained synthetic images and SEDs of the dust component through radiative transfer calculations.

Results. This model results in long-lived inner disks and fast dispersing outer disks that can reproduce both the accretion rates and gap sizes observed in transition disks. For a dead zone of turbulence αdz = 10−4 and an extent rdz = 10 AU, our population synthesis study shows that 63% of our transition disks are still accreting with Ṁg ≥ 10−11 M⊙ yr−1 after opening a gap. Among those accreting transition disks, half display accretion rates higher than 5.0 × 10−10 M⊙ yr−1. The dust component in these disks is distributed in two regions: in a compact inner disk inside the dead zone, and in a ring at the outer edge of the photoevaporative gap, which can be located between 20 and 100 AU. Our radiative transfer calculations show that the disk displays an inner disk and an outer ring in the millimeter continuum, a feature that resembles some of the observed transition disks.

Conclusions. A disk model considering X-ray photoevaporative dispersal in combination with dead zones can explain several of the observed properties in transition disks, including the high accretion rates, the large gaps, and a long-lived inner disk at millimeter emission.
Evidence for stellar contamination in the transmission spectra of HAT-P-12b
Authors: Jiang C. , Chen G. , Pallé E. , Murgas F. , Parviainen H. , Yan F. , Ma Y.
Published: September 2021

Context. Transmission spectroscopy characterizes the wavelength dependence of transit depth, revealing atmospheric absorption features in planetary terminator regions. In this context, different optical transmission spectra of HAT-P-12b reported in previous studies exhibited discrepant atmospheric features (e.g., Rayleigh scattering and alkali absorption).

Aims. We aim to understand the atmosphere of HAT-P-12b using two transit spectroscopic observations by the Gran Telescopio Canarias (GTC) and to search for evidence of stellar activity contaminating the transmission spectra, which might be the reason behind the discrepancies.

Methods. We used Gaussian processes to account for systematic noise in the transit light curves and used nested sampling for Bayesian inferences. We performed joint atmospheric retrievals using the two transmission spectra obtained by GTC OSIRIS, as well as previously published results, coupled with stellar contamination corrections for different observations.

Results. The retrieved atmospheric model exhibits no alkali absorption signatures, but shows tentative molecular absorption features including H2O, CH4, and NH3. The joint retrieval of the combined additional public data analysis retrieves similar results, but with a higher metallicity.

Conclusions. Based on Bayesian model comparison, the discrepancies of the transmission spectra of HAT-P-12b can be explained by the effect of different levels of unocculted stellar spots and faculae. In addition, we did not find strong evidence for a cloudy or hazy atmosphere from the joint analysis, which is inconsistent with prior studies based on the observations of the Hubble Space Telescope.
OMEP-EOR: A MeV proton flux specification model for electric orbit raising missions
Authors: Brunet Antoine , Sicard Angélica , Papadimitriou Constantinos , Lazaro Didier , Caron Pablo
Published: September 2021

Electric Orbit Raising (EOR) for telecommunication satellites significantly reduced on-board fuel mass at the price of extended transfer durations. These relatively long transfers, which usually span a few months, cross large spans of the radiation belts, resulting in significant exposure of the spacecraft to space radiations. Since they are not very populated, the radiation environment of intermediate regions of the radiation belts is less constrained than on popular orbits such as low Earth orbit or geostationary orbit in standard environment models. In particular, there is a need for more specific models for the MeV energy range proton fluxes, responsible for solar arrays degradations, and hence critical for EOR missions. ONERA has developed a specification model of proton fluxes dedicated for EOR missions as part of the ESA ARTES program. This model can estimate the average proton fluxes between 60 keV and 20 MeV on arbitrary trajectories on the typical duration of EOR transfers. A global statistical model of the radiation belts was extracted from the Van Allen Probes RBSPICE data. For regions with no or low sampling, simulation results from the Salammbô radiation belt model were used. Special care was taken to model the temporal dynamics of the belts on the considered mission durations. A Gaussian Process model was developed, allowing to compute the distribution of the average fluxes on arbitrary mission durations analytically. Satellites trajectories can be flown in the resulting global distribution, yielding the proton flux spectrum distribution as seen by the spacecraft. We show the results of the model on a typical EOR trajectory. The obtained fluxes are compared to the standard AP8 model, the AP9 model and validated using the THEMIS satellites data. We illustrate the expected effect on solar cell degradation, where our model shows an increase of up to 20% degradation prediction compared to AP8.
Bilder sind Daten: Eine Perspektive der Brustbildgebung auf ein zeitgenössisches Paradigma
Authors: Dietzel Matthias , Clauser Paola , Kapetas Panagiotis , Schulz-Wendtland Rüdiger , Baltzer Pascal Andreas Thomas
Published: September 2021

Hintergrund Radiologische Untersuchungen nicht nur als bloße Bilder, sondern als Datenquelle zu betrachten, ist zum modernen Paradigma der diagnostischen Bildgebung geworden. Dieser Perspektivwechsel hat sich besonders in der Brustbildgebung durchgesetzt, ermöglicht er doch, aus der Informatik abgeleitete Verfahren anzuwenden, innovative klinische Anwendungen zu realisieren und bereits etablierte Methoden zu verfeinern. In diesem Zusammenhang sind die Begriffe „bildgebender Biomarker“, „Radiomics“ und „künstliche Intelligenz“ von zentraler Bedeutung. Diese Methoden versprechen nichtinvasive, kostengünstige (z. B. im Vergleich zu Multigen-Arrays), workflow-freundliche (automatisiert, nur eine Untersuchung, sofortige Ergebnisse) und klinisch relevante Informationen.

Methoden und Ergebnisse Dieser Artikel wurde als narratives Review zu dem besagten Paradigma im Bereich der Brustbildgebung konzipiert. Der Schwerpunkt liegt auf den Schlüsselkonzepten und wichtigen Schlagworten. Für alle Bereiche der Brustbildgebung werden beispielhafte Studien diskutiert.

Schlussfolgerung Die Interpretation von radiologischen Untersuchungen als Datenquelle verspricht eine Optimierung der Behandlung von Brustkrebspatientinnen im Zeitalter der Präzisionsmedizin, weil damit die Diagnose verfeinert und eine individualisierte Behandlung erreicht werden könnte.

Kernaussagen:
Verteilung des 21-Gen-Rezidiv-Scores bei Patientinnen mit primärem Mammakarzinom in Deutschland
Authors: Walter Vincent P. , Taran Florin-Andrei , Wallwiener Markus , Bauer Armin , Grischke Eva-Maria , Walter Christina Barbara , Hahn Markus , Brucker Sara Y. , Hartkopf Andreas Daniel
Published: September 2021

Einleitung Multigen-Assays werden zunehmend als Entscheidungshilfe für eine Chemotherapie beim Mammakarzinom verwendet. Wir stellen hier den 21-Gen-Recurrence-Score (RS) von Patientinnen mit Brustkrebs vor, die routinemäßig in Deutschland untersucht wurden.

Patientinnen und Methoden 4695 Patientinnen mit hormonrezeptorpositivem und HER2-negativem Brustkrebs im Frühstadium (pT1–3, pN0–1, M0) wurden einer retrospektiven Analyse unterzogen. Bei diesen Patientinnen wurde in Deutschland zwischen November 2015 und Juli 2018 der Genexpressionstest Oncotype DX zur Ermittlung des Recurrence-Scores durchgeführt. Die Klassifikation der RS-Gruppen erfolgte gemäß der TAILORx Studie (RS: 0–10; 11–25; 26–100).

Ergebnisse Von diesen Patientinnen wurden 21 % in die niedrige RS-Gruppe, 63 % in die mittlere RS-Gruppe, und 15 % in die hohe RS-Gruppe eingeteilt. 1772 (81 %) von 2175 Patientinnen im Alter von über 50 Jahren und ohne Lymphknotenbefall wurden entweder in die niedrige oder die mittlere RS-Gruppe eingeteilt. Der Prozentsatz an Patientinnen mit einem niedrigen oder mittleren RS betrug 90 % bei Patientinnen ohne Lymphknotenbefall (1284 von 1432 Patientinnen), 79 % bei Patientinnen mit einem hohen (≥ 20 %) Ki-67-Wert (1829 von 2310 Patientinnen), 86 % bzw. 70 % bei Patientinnen mit G2- bzw. G3-Tumoren (3244 von 3762 Patientinnen bzw. 368 von 522 Patientinnen), 88 % bei Patientinnen mit einem Tumordurchmesser von > 5 cm (140 von 159 Patientinnen) und 82 % bei Patientinnen ohne Lymphknotenbefall, aber mit einem hohen klinischen Risiko (1110 von 1352).

Schlussfolgerung Die Verteilung des 21-Gens RS bei deutschen Patientinnen, die in der klinischen Routinepraxis getestet wurden, deutet darauf hin, dass gemäß den Ergebnissen der TAILORx-Studie die Chemotherapie bei den meisten dieser Patientinnen keinen Nutzen hat.
Gewalt gegen Kreißsaalpersonal – Ergebnisse einer
Online-Befragung und von Leitfadeninterviews an Berliner
Geburtskliniken
Authors: Böhle Saskia , David Matthias , Breckenkamp Jürgen , Henrich Wolfgang , Seidel Vera
Published: September 2021

Einleitung Gewalt gegenüber medizinischem Personal ist ein
bekanntes Problem in der Notfallversorgung. Es gibt wenig empirische Daten zu
körperlicher und verbaler Gewalt gegen Kreißsaal-Personal in
Deutschland.

Methodik Es handelt sich um eine Studie mit quantitativer und qualitativer
Datenerhebung. Für die quantitative Erhebung wurden zwischen dem
15.11.2019 und 15.02.2020 Hebammen, Ärztinnen und Ärzte, die in
Kreißsälen Berliner Geburtskliniken tätig sind, mittels
Fragebogen zu Gewalterleben innerhalb der letzten 6 Monate befragt. Im Rahmen
der qualitativen Erhebung wurde die Thematik mittels Leitfadeninterviews
vertiefend beleuchtet.

Ergebnisse Von 173 Teilnehmern waren nach eigenen Angaben 148
(86%) verbaler Gewalt und 82 (47%) körperlicher Gewalt
ausgesetzt. Hebammen und junges Personal scheinen häufiger von Gewalt
betroffen zu sein. Von den Teilnehmenden fühlten sich ca. 70%
nicht ausreichend auf Gewaltsituationen vorbereitet. In den 36 Interviews wurden
insbesondere Kommunikationsprobleme, zu hohe Erwartungshaltungen der Schwangeren
und ihrer Begleitung, Sprachbarrieren und kulturelle Missverständnisse
als Gewalt begünstigend genannt.

Schlussfolgerung Gewalt gegen Personal ist ein relevantes Problem in
Kreißsälen in Berlin. Schulungsangebote zum Umgang mit Gewalt
und professionelle Aufarbeitung von Gewalterlebnissen wurden von den Befragten
gewünscht. Verbesserte Aufklärung über Schwangerschaft
und Geburt, institutionalisierte Sprachmittlung und mehr Personal
könnten helfen, die Häufigkeit von Gewalt zu senken.
Assessment of Oral Anticancer Medication Adherence: A Survey from a Tertiary Cancer Center
Authors: Ramachandiran Balaji , Dubashi Biswajit , Kayal Smita , Menon Vikas , Yuvaraj K. , Deepika C. , Francis Deepa , Debbarma Deeksha , Nair Devika S.
Published: September 2021

Background Adherence to oral anticancer medication is important in cancer chemotherapy, with the advent of many oral anticancer regimens to ensure adequate cytologic response. Literature on adherence to oral anticancer therapy in India is very less.

Materials and Methods This is a cross sectional analytical study consisting of all fit patients > 18 years of age taking oral anticancer therapy, with or without intravenous (IV) chemotherapy. Adherence was determined using Morisky–Green–Levine (MGL) scale, and factors affecting adherence details about cancer and treatment were obtained. All fit patients were recruited. Information was obtained using Tamil questionnaire and pro forma.

Observation Of 152 patients, only 111 patients were found to be adherent to treatment. The mean age of the study population was 49.03 ± 13.48 years. Only 12.5% of patients were aware of the diagnosis, treatment, and outcome. The study population consisted mainly of patients with chronic myeloid leukemia, colorectal carcinoma, breast carcinoma, and stomach carcinoma, which amounted for 78.3% of the study population. Bivariate analysis concluded that duration of treatment, adverse drug reaction (ADR), duration of oral anticancer drug intake in a month, coadministration with IV anticancer drugs, and frequency of drug intake (anticancer drug) were significant factors affecting drug adherence. Multivariate analysis of the above variables was insignificant, but ADR tended toward significance.

Conclusion Drug adherence plays a major role in treatment outcome in cancer patients. ADR was independently associated with decreased drug adherence. Key interventions which should include counseling and behavioral modifications will reduce nonadherence.
Liderazgo femenino en medicina y su evolución en el tiempo: 50 años de análisis bibliométrico
Authors: Mendoza Catalina Solano , Gomez Andrea Patricia Bolaños , Tobar Veronica , Carvajal Luisana Castillo , Vega Johanna , Jaimes Luz Marina Bernal
Published: September 2021

Objetivo Realizar un análisis bibliométrico sobre el liderazgo femenino en medicina para conocer el panorama actual y dirigir futuras investigaciones.

Métodos Se realizó un análisis bibliométrico descriptivo retrospectivo de la literatura disponible en MEDLINE en relación con el liderazgo de mujeres médicas de 1973 al 2019.

Se utilizó Pubmed y FABUMED, y la siguiente estrategia: ("Leadership"[Mesh]) AND "Physicians, Women"[Mesh] (1973:2019[dp]). Se incluyeron artículos originales, de revista, ensayos, informes científicos y reseñas, para analizar toda la literatura indexada relacionada.

Para la obtención del factor de impacto (FI), se utilizó el Journal Citation Reports (7)2017/2018 de las revistas encontradas para estimar la calidad de cada una de ellas.

Resultados Un total de 310 referencias fueron encontradas en 139 revistas publicadas, el 71,2% fueron artículos originales, el resto revisiones. Hubo un incremento en las publicaciones de 1996 al 2019 en un 11,9%. Las revistas con mayor porcentaje de publicaciones fueron: Academic Medicine y J Womens Health (Larchmt), con 7,7% y 7,1%. Los países con mayores publicaciones fueron Estados Unidos, con 66 (56%) y Reino Unido con 10 (8,6%). América latina tiene cuatro publicaciones y Colombia no cuenta con ninguna publicación indexada.

Conclusión El liderazgo femenino en medicina y las publicaciones sobre el tema han aumentado en las últimas décadas en países industrializados. Por su parte, Latinoamérica debe aumentar sus esfuerzos en publicar en revistas con alto factor de impacto para trabajar por la equidad de género.
The Effect of Glyphosate on Human Sperm: In Vitro Approximation
Authors: Morales Velásquez Mateo , Velásquez Rivera Valentina , Cardona Maya Walter D.
Published: September 2021

Introduction Glyphosate is an herbicide used to eradicate illicit crops; however, its use is controversial due to different health problems associated with it. The present study aims to evaluate the effects of glyphosate on human sperm in vitro.

Methods Twenty-two semen samples from healthy normozoospermic men were included; 11 semen samples were incubated with Panzer (INVESA S.A., Antiquia, Colombia) and 11 with Roundup (Monsanto Company, MO, USA). The changes in motility and viability were observed. Functional seminal parameters were evaluated as well.

Results The samples exposed to glyphosate showed less motility and viability; a decrease in the potential of the mitochondrial membrane was observed, and an increase in the lipoperoxidation of the membrane was evidenced.

Conclusion Based on the present results, we concluded that glyphosate has cytotoxic potential for exposed people and may affect their fertility.
Randomized Double-Blind, Placebo-Controlled Feasibility Study, Evaluating the Efficacy of Homeopathic Medicines in the Prevention of COVID-19 in a Quarantined Population
Authors: Talele Gitanjali , Vaidhya Shashikant , Chowdhary Abhay , Herscu Paul , Shah Rajesh
Published: September 2021

Introduction Exploring preventive therapeutic measures has been among the biggest challenges during the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We explored the feasibility and methods of recruitment, retention, and potential signal of efficacy, of selected homeopathic medicines as preventive measure for developing COVID-19 in a multi-group study.

Methods A six-group, randomized, double-blind, placebo-controlled prophylaxis study was conducted in a COVID-19 exposed population in a quarantine facility in Mumbai, India. Each group received one of the following: Arsenicum album 30c, Bryonia alba 30c, a combination (Arsenicum album 30c, Bryonia alba 30c, Gelsemium sempervirens 30c, and Influenzinum 30c), coronavirus nosode CVN01 30c, Camphora 1M, or placebo. Six pills twice a day were administered for 3 days. The primary outcome measure used was testing recruitment and retention in this quarantined setting. Secondary outcomes were numbers testing positive for COVID-19 after developing symptoms of illness, number of subjects hospitalized, and days to recovery.

Results Good rates of recruitment and retention were achieved. Of 4,497 quarantined individuals, 2,343 sought enrollment, with 2,294 enrolled and 2,233 completing the trial (49.7% recruitment, 97.3% retention). Subjects who were randomized to either Bryonia alba or to the CVN01 nosode signaled (p <0.10) a lower incidence of laboratory-confirmed COVID-19 and a shorter period of illness, with evidence of fewer hospitalizations, than those taking placebo. The three other groups did not show signals of efficacy.

Conclusion This pilot study supports the feasibility of a larger randomized, double-blind, placebo-controlled trial. Bryonia alba 30c and CVN01 30c should both be explored in disease prevention or shortening the course of disease symptomatology in a COVID-19-exposed population.
Perception of Harrasment or Discrimination during Urology Residency in Colombia
Authors: Ortiz-Zableh Ana María , Quiñones Roa Andres Felipe , Santamaria Fuerte Bernardo , Tobar-Roa Veronica
Published: September 2021

Purpose Workplace bullying (harassment, abuse, or discrimination), practiced persistently against an individual, can generate a hostile workplace environment, consequently leading to exhaustion, with poor psychological outcomes, and the onset of symptoms such as loss of confidence, fatigue, depressive thoughts, desertion, and suicidal thoughts. There are no publications regarding this issue in Colombia.

Our objective is to describe the residents' perception of gender and workplace discrimination and verbal/sexual harassment during their urological training.

Methods Observational, descriptive, cross-sectional study with anonymous surveys. We evaluated the demographic characteristics and the residents' perception of harassment, the type of harassment, how it affected their performance during residency, and from whom it was perceived.

Results We were able to obtain answers from 82/115 residents (71.3%), most of them men (45 [56%]). In total, 66% (54) reported workplace harassment; and 35.4% (29) felt gender discrimination, most of them women (17; 58.6%). Verbal abuse was reported by 64.6% (53), and it affected the work of 92.5%. The parception of workplace harassment was similar among both men and women (32 [69.5%] men and 21 [61.1%] women). A total of 7(19%) women reported sexual abuse. Regarding the source of the abuse, 39 (65.8%) was by professors, 26 (45%), by other residents, and 17 (35.4%), by patients.

Conclusion The perception of harassment during urology residency in Colombia is real, and it affects the work of residents. This abuse is greater on the part of men, and is mainly perpetrated by professors. We consider our work the starting point to continue researching a topic of national and international importance.
Imperial policy of the Russian Federation versus cohesion and coherence of NATO’s new strategic concept
Authors: Mierzwa Danuta , Tomaszycki Marek
Published: September 2021

The article presents a multifaceted analysis of threats to Central and Eastern Europe by the Russian Federation. Russia’s imperial policy, as set out in Gerasimov doctrines in 2013 and 2019, forced NATO to develop a new strategic concept. NATO’s new strategic concept was put forward at NATO Summits of 2018 and 2019 by Member State leaders, and it defines a new strategy to deter a potential aggressor. The new strategic concept is based on NATO’s strategy of cohesion and coherence discussed in detail in this article. NATO’s new strategic concept was a result of Russian military operations in Ukraine, Georgia, Estonia and Montenegro, as well as the deployment of Russian forces on Russia’s western and southern borders. Nowadays, when the application of a new strategy can give a significant advantage, Russia’s imperial policy using cutting edge technology seems unpredictable, as it does not give the enemy a chance to repel an attack in a timely manner. Thus, NATO’s new strategic concept contributes to creating a space of security cooperation for Member States.
High-density low-loss millimeter-wave package interconnects with the impact of dielectric-material surface roughness
Authors: Watanabe Atom O. , Kanno Kimiyuki , Ito Hirokazu , Tummala Rao R. , Swaminathan Madhavan
Published: September 2021

Heterogeneous package integration and chiplet approaches are the key technology to enable next-generation high performance small form-factor packages for emerging applications. Millimeter-wave packaging for fifth-generation and upcoming sixth-generation platforms also need to meet the high-density low signal-loss interconnect specifications utilizing advanced conductor and dielectric materials. This article presents the comparison of the liquid-based photoimageable dielectric (PID) and dry-film dielectric materials in terms of interconnect path losses that are critical in mm-wave frequency bands. The conductor loss being more dominant in the frequency bands and in thinner dielectric structures, we assess daisy chains and microstrip lines on 15-μm dielectric by measuring the S-parameters to quantify the impact of the surface roughness at around 28 GHz. Measured results from the daisy chain and microstrip line structures exhibit that the smooth surface of the liquid-based PID (3 nm) leads to 8%–32% lower signal loss in the dB scale than the 325-nm rough dry-film dielectric. The study provides comprehensive experimental results that the different material forms with various surface roughness largely impact the package-level interconnect loss.
Comparative analysis of laser and simulated speckle pattern for single shot 3D reconstruction
Authors: Khan Danish , Kim Min Young
Published: September 2021

Stereo photogrammetry is a fundamental technique for 3D measurements in different applications. As passive stereo methods struggle in texture-less regions, different light-coded patterns are projected to solve the correspondence problem. When the reconstruction method requires a series of sequentially coded light patterns, the system is prone to movement-related errors. A single pattern is utilized where the potential subjects are dynamic or change the position rapidly. A random speckle pattern is a good candidate for such systems. Primarily, there are two approaches to generate the speckle pattern in stereoscopic systems. The speckles can be generated by the coherent illumination of a laser diode, and the laser speckle-like pattern can also be simulated and projected by a professional projector. The purpose of both is to solve the stereo correspondence problem; however, the performance of both can differ, subjective to employed 3D sensing algorithm. In this Letter, we compare the performance of both for single-shot 3D reconstruction. We have discussed the pros and cons of both methods and analyze their ability to resolve long range 3D reconstruction.
High-throughput assays show the timescale for phagocytic success depends on the target toughness
Authors: Bakhtiari Layla A. , Wells Marilyn J. , Gordon Vernita D.
Published: September 2021

Phagocytic immune cells can clear pathogens from the body by engulfing them. Bacterial biofilms are communities of bacteria that are bound together in a matrix that gives biofilms viscoelastic mechanical properties that do not exist for free-swimming bacteria. Since a neutrophil is too small to engulf an entire biofilm, it must be able to detach and engulf a few bacteria at a time if it is to use phagocytosis to clear the infection. We recently found a negative correlation between the target elasticity and phagocytic success. That earlier work used time-consuming, manual analysis of micrographs of neutrophils and fluorescent beads. Here, we introduce and validate flow cytometry as a fast and high-throughput technique that increases the number of neutrophils analyzed per experiment by two orders of magnitude, while also reducing the time required to do so from hours to minutes. We also introduce the use of polyacrylamide gels in our assay for engulfment success. The tunability of polyacrylamide gels expands the mechanical parameter space we can study, and we find that high toughness and yield strain, even with low elasticity, also impact the phagocytic success as well as the timescale thereof. For stiff gels with low-yield strain, and consequent low toughness, phagocytic success is nearly four times greater when neutrophils are incubated with gels for 6 h than after only 1 h of incubation. In contrast, for soft gels with high-yield strain and consequent high toughness, successful engulfment is much less time-sensitive, increasing by less than a factor of two from 1 to 6 h incubation.
Modeling lipid–protein interactions for coarse-grained lipid and Cα protein models
Authors: Ugarte La Torre Diego , Takada Shoji
Published: September 2021

Biological membranes that play major roles in diverse functions are composed of numerous lipids and proteins, making them an important target for coarse-grained (CG) molecular dynamics (MD) simulations. Recently, we have developed the CG implicit solvent lipid force field (iSoLF) that has a resolution compatible with the widely used Cα protein representation [D. Ugarte La Torre and S. Takada, J. Chem. Phys. 153, 205101 (2020)]. In this study, we extended it and developed a lipid–protein interaction model that allows the combination of the iSoLF and the Cα protein force field, AICG2+. The hydrophobic–hydrophilic interaction is modeled as a modified Lennard-Jones potential in which parameters were tuned partly to reproduce the experimental transfer free energy and partly based on the free energy profile normal to the membrane surface from previous all-atom MD simulations. Then, the obtained lipid–protein interaction is tested for the configuration and placement of transmembrane proteins, water-soluble proteins, and peripheral proteins, showing good agreement with prior knowledge. The interaction is generally applicable and is implemented in the publicly available software, CafeMol.
Identification of free and bound exciton emission of MgO single crystal in vacuum ultraviolet spectral range
Authors: Onuma Takeyoshi , Kosaka Wataru , Kudo Kanta , Ota Yuichi , Yamaguchi Tomohiro , Kaneko Kentaro , Fujita Shizuo , Honda Tohru
Published: September 2021

Temperature dependencies of optical reflectance and cathodoluminescence (CL) spectra were measured for the MgO single crystal using a custom-built vacuum ultraviolet (VUV) spectroscopic system. Simultaneous observation enabled us to identify free exciton (FE) and bound exciton (BE) emissions by comparing the CL emission with the exciton resonance structures. The results indicated that the BE emission dominates the near-band edge emission, and the FE emission was observed as a shoulder at 300 K. The results ensure strong excitonic nature and potential of a rock salt-structured MgO-based material system for an active element in the VUV light emitter.
Properties of aqueous 1,4-dioxane solution via molecular dynamics
Authors: Bakulin I. , Kondratyuk N. , Lankin A. , Norman G.
Published: September 2021

Polyethers are promising compounds for the creation of electrochemical energy storage systems. The molecular dynamics method can facilitate the search of compounds that have the most potential. However, the application of this method requires verification of the force fields. We perform molecular dynamics calculations of the physical properties of the aqueous 1,4-dioxane solution (density, enthalpy of mixing, and viscosity) and compare them to the available experimental data. In addition, we confirm the idea that the solution structure depends on the dioxane molar fraction, proposed in the experiment of Takamuku et al. [J. Mol. Liq. 83(1-3), 163–177 (1999)]. The hydrogen bonds between dioxane and water are analyzed. The correlation between the excess viscosity and enthalpy of mixing is demonstrated.
Impurity diffusion in magic-size icosahedral clusters
Authors: Nelli Diana , Pietrucci Fabio , Ferrando Riccardo
Published: September 2021

Atomic diffusion is at the basis of chemical ordering transformations in nanoalloys. Understanding the diffusion mechanisms at the atomic level is therefore a key issue in the study of the thermodynamic behavior of these systems and, in particular, of their evolution from out-of-equilibrium chemical ordering types often obtained in the experiments. Here, the diffusion is studied in the case of a single-atom impurity of Ag or Au moving within otherwise pure magic-size icosahedral clusters of Cu or Co by means of two different computational techniques, i.e., molecular dynamics and metadynamics. Our simulations reveal unexpected diffusion pathways, in which the displacement of the impurity is coupled with the creation of vacancies in the central part of the cluster. We show that the observed mechanism is quite different from the vacancy-mediated diffusion processes identified so far, and we demonstrate that it can be related to the presence of non-homogeneous compressive stress in the inner part of the icosahedral structure.
Prospects in x-ray science emerging from quantum optics and nanomaterials
Authors: Wong Liang Jie , Kaminer Ido
Published: September 2021

The science of x-rays is by now over 125 years old, starting with Wilhelm Röntgen's discovery of x-rays in 1895, for which Röntgen was awarded the first Nobel Prize in Physics. X-rays have fundamentally changed the world in areas, including medical imaging, security scanners, industrial inspection, materials development, and drugs spectroscopy. X-ray science has been so far responsible for over 25 Nobel Prizes in Physics, Chemistry, and Medicine/Physiology. With x-ray generation being a highly commercialized, widely adopted technology, it may appear that there is little left to discover regarding the fundamentals of x-ray science. Contrary to this notion, recent years have shown renewed interest in the research and development of innovative x-ray concepts. We highlight, in this Perspective, promising directions for future research in x-ray science that result from advances in quantum science and in nanomaterials. Specifically, we describe three key opportunities for advancing x-ray science in the near future: (1) emerging material platforms for x-ray generation, especially 2D materials and their heterostructures; (2) free-electron-driven emission of entangled photon–photon and electron–photon pairs for x-ray quantum optics; and (3) shaping free-electron wavepackets for controllable x-ray emission. These research directions could lead to improvements in x-ray resonance fluoroscopy, high-contrast x-ray imaging, stimulated coherent x rays, x-ray superradiance, and other prospects for x-ray quantum optics.
On the inclusion of one double within CIS and TDDFT
Authors: Athavale Vishikh , Teh Hung-Hsuan , Subotnik Joseph E.
Published: September 2021

We present an improved approach for generating a set of optimized frontier orbitals (HOMO and LUMO) that minimizes the energy of one double configuration. We further benchmark the effect of including such a double within a rigorous configuration interaction singles or a parameterized semi-empirical time-dependent density functional theory Hamiltonian for a set of test cases. Although we cannot quite achieve quantitative accuracy, the algorithm is quite robust and routinely delivers an enormous qualitative improvement to standard single-reference electronic structure calculations.
Excimer laser liftoff of AlGaN/GaN HEMTs on thick AlN heat spreaders
Authors: Alam Md Didarul , Gaevski Mikhail , Jewel Mohi Uddin , Mollah Shahab , Mamun Abdullah , Hussain Kamal , Floyd Richard , Simin Grigory , Chandrashekhar MVS , Khan Asif
Published: September 2021

We report on 193 nm excimer laser-based liftoff (LLO) of Al0.26Ga0.74N/GaN high electron mobility transistors (HEMTs) with thick (t > 10 μm) AlN heat spreading buffer layers grown over sapphire substrates. The use of the thick AlN heat spreading layer resulted in thermal resistance (Rth) of 16 K mm/W for as-fabricated devices on sapphire, which is lower than the value of ∼25–50 K mm/W for standard HEMT structures on sapphire without the heat-spreaders. Soldering the LLO devices onto a copper heat sink led to a further reduction of Rth to 8 K mm/W, a value comparable to published measurements on bulk SiC substrates. The reduction in Rth by LLO and bonding to copper led to significantly reduced self-heating and drain current droop. A drain current density as high as 0.9 A/mm was observed despite a marginal reduction of the carrier mobility (∼1800 to ∼1500 cm2/V s). This is the highest drain current density and mobility reported to-date for LLO AlGaN/GaN HEMTs.
The critical behavior of the clogging process in a porous medium
Authors: Seybold H. J. , Lima Izael A. , Araújo Ascânio D.
Published: September 2021

Flows through porous media can carry suspended and dissolved materials. These sediments may deposit inside the pore-space and alter its geometry. In turn, the changing pore structure modifies the preferential flow paths, resulting in a strong coupling between structural modifications and transport characteristics. Here, we compare two different models that lead to channel obstruction as a result of subsequent deposition. The first model randomly obstructs pore-throats across the porous medium, while the second model always blocks the pore-throat with the highest flow rate. By subsequently closing pores, we find that the breakdown of the permeability follows a power-law scaling, whose exponent depends on the obstruction model. The pressure jumps that occur during the obstruction process follow a universal power-law distribution with the same scaling exponent as the avalanche size distribution of invasion percolation. The fact that this exponent is also independent of the model suggests that the clogging processes and invasion percolation may belong to the same universality class.
Forward and backward electron transfer on Pt loaded TiO2 photocatalysts under visible-light illumination
Authors: Inoue Naohiro , Shiraki Kyohei , Kato Kosaku , Ashimura Shu , Yoshida Masaaki , Yamakata Akira
Published: September 2021

The surface plasmon resonance (SPR) effects of metal nanoparticles prove versatile in terms of equipping wideband-gap photocatalysts, such as TiO2, with visible-light responsiveness. In this regard, Au is the most frequently used material for its SPR, but alternative materials are also being actively developed to effectively utilize solar light from the visible to the near-infrared region. In this work, we found that Pt particles loaded on TiO2 were also active in effecting SPR-induced photocatalysis. Time-resolved absorption measurements confirmed that visible-light irradiation induces electron transfer from Pt to TiO2, and the efficiency of this electron injection increases as the wavelength of the incident light decreases from 660 to 450 nm. Observations of the peak shift of the vibrational frequency of adsorbed CO on Pt confirmed that the Fermi level of Pt decreases as the electron transfer from Pt to TiO2 proceeds. These results imply that Pt nanoparticles can act as sensitizers to induce electron transfer from Pt to TiO2, although Pt is a well-known cocatalyst that enhances H2 evolution by collecting electrons from TiO2. However, as the intensity of the irradiated light increased beyond 50 mW cm−2, a portion of the Pt particles started to capture the injected electrons from TiO2, suggesting that the electron transfer from one Pt particle to the other Pt particles via the conduction band of TiO2 proceeds under visible light illumination. These opposing roles may be ascribed to the variation in the size of Pt particles as well as density of electrons injected into TiO2.
Structure of benzothiadiazine at zwitterionic phospholipid cell membranes
Authors: Hu Zheyao , Martí Jordi , Lu Huixia
Published: September 2021

The use of drugs derived from benzothiadiazine, which is a bicyclic heterocyclic benzene derivative, has become a widespread treatment for diseases such as hypertension (treated with diuretics such as bendroflumethiazide or chlorothiazide), low blood sugar (treated with non-diuretic diazoxide), or the human immunodeficiency virus, among others. In this work, we have investigated the interactions of benzothiadiazine with the basic components of cell membranes and solvents, such as phospholipids, cholesterol, ions, and water. The analysis of the mutual microscopic interactions is of central importance to elucidate the local structure of benzothiadiazine as well as the mechanisms responsible for the access of benzothiadiazine to the interior of the cell. We have performed molecular dynamics simulations of benzothiadiazine embedded in three different model zwitterionic bilayer membranes made by dimyristoylphosphatidylcholine, dioleoylphosphatidylcholine, 1,2-dioleoyl-sn-glycero-3-phosphoserine, and cholesterol inside aqueous sodium-chloride solution in order to systematically examine microscopic interactions of benzothiadiazine with the cell membrane at liquid-crystalline phase conditions. From data obtained through radial distribution functions, hydrogen-bonding lengths, and potentials of mean force based on reversible work calculations, we have observed that benzothiadiazine has a strong affinity to stay at the cell membrane interface although it can be fully solvated by water in short periods of time. Furthermore, benzothiadiazine is able to bind lipids and cholesterol chains by means of single and double hydrogen-bonds of different characteristic lengths.
Sigmoidal curves of stochastic magnetic tunnel junctions with perpendicular easy axis
Authors: Kobayashi Keito , Borders William A. , Kanai Shun , Hayakawa Keisuke , Ohno Hideo , Fukami Shunsuke
Published: September 2021

We investigate the physical mechanism governing the sigmoid-like time-averaged response of stochastic magnetic tunnel junctions (s-MTJ), which is a promising building block for probabilistic computers. We measure the time-averaged resistance of perpendicular easy-axis s-MTJs with various free-layer thicknesses and diameters as functions of an external magnetic field and current. The time-averaged response shows no significant dependence on the free-layer thickness, whereas significantly varies with the diameter. Based on the Néel-Arrhenius law, we derive an analytical expression of the time-averaged response against both the magnetic field and current and discuss the underlying mechanism accounting for the obtained results. We show that the experimental results are well explained by considering magnetically active and electrically active volumes of the superparamagnetic free layer in s-MTJs. The obtained finding provides an important design guideline of s-MTJs for probabilistic computers.
Nonuniqueness of generalized quantum master equations for a single observable
Authors: Ng Nathan , Limmer David T. , Rabani Eran
Published: September 2021

When deriving exact generalized master equations for the evolution of a reduced set of degrees of freedom, one is free to choose what quantities are relevant by specifying projection operators. However, obtaining a reduced description does not always need to be achieved through projections—one can also use conservation laws for this purpose. Such an operation should be considered as distinct from any kind of projection; that is, projection onto a single observable yields a different form of master equation compared to that resulting from a projection followed by the application of a constraint. We give a simple example to show this point and give relationships that the different memory kernels must satisfy to yield the same dynamics.
Effect of climate variability on water quality trends in New Zealand rivers
Authors: Snelder T. H. , Larned S. T. , Fraser C. , De Malmanche S.
Published: September 2021

Associations between temporal variability in 10 water quality variables and the El Niño–Southern Oscillation (ENSO) climate pattern, quantified by the Southern Oscillation Index (SOI), were assessed at 56 river sites in New Zealand over a 31-year period (1989–2019). Fluctuations in monthly observations of water quality at each site were correlated to varying degrees with the corresponding SOI value (ro). Trends for rolling windows of 5-, 10- and 15-year duration were evaluated for each site and variable using Kendall’s tau (τw) and for the SOI using linear regression (δSOIw). Aggregate trends for each variable, duration and time window were quantified as proportions of site trends that were increasing (Pw). Fluctuations in τw and Pw between time windows for all durations were explained by the corresponding SOI trend (δSOIw). Between-site and between-variable differences in the trend responses to the SOI trends were explained by the corresponding ro values and the median of the ro values (MF21087_IE1.gif) respectively. These results indicate that climate variability makes a significant contribution to water quality trends, even at timescales longer than ENSO cycles. Our models can be used to quantify this contribution for individual sites (i.e. τw) and for aggregate trends (i.e. Pw).
Unraveling the hidden role of a uORF-encoded peptide as a kinase inhibitor of PKCs
Authors: Jayaram Divya Ram , Frost Sigal , Argov Chanan , Liju Vijayasteltar Belsamma , Anto Nikhil Ponnoor , Muraleedharan Amitha , Ben-Ari Assaf , Sinay Rose , Smoly Ilan , Novoplansky Ofra , Isakov Noah , Toiber Debra , Keasar Chen , Elkabets Moshe , Yeger-Lotem Esti , Livneh Etta
Published: September 2021

Significance

Bioinformatic analysis revealed that approximately 40% of human messenger RNAs contain upstream open reading frames (uORFs) in their 5′ untranslated regions. Some of these sequences are translated, but the function of the encoded peptides remains unknown. Our study revealed a uORF encoding for a peptide exhibiting kinase inhibitory activity. This uORF, upstream of a PKC family member, possess the typical pseudosubstrate motif, which autoinhibits the catalytic activity of all PKCs. Using mouse models and human cells, we show that this peptide inhibits cancer cell survival, tumor progression, invasion, and metastasis and synergizes with chemotherapy by interfering with DNA damage response. Together, we point to a previously unrecognized function of a uORF-encoded peptide as a kinase inhibitor, pertinent to cancer therapy.
Automated design of pulse sequences for magnetic resonance fingerprinting using physics-inspired optimization
Authors: Jordan Stephen P. , Hu Siyuan , Rozada Ignacio , McGivney Debra F. , Boyacioğlu Rasim , Jacob Darryl C. , Huang Sherry , Beverland Michael , Katzgraber Helmut G. , Troyer Matthias , Griswold Mark A. , Ma Dan
Published: September 2021

Significance

Magnetic resonance is a widely used noninvasive medical imaging technology. Most clinical MRI scans generate qualitative or “weighted” images. A recent new technology, magnetic resonance fingerprinting (MRF), simultaneously extracts quantitative voxel-by-voxel measurements of multiple intrinsic tissue properties such as

T

1

and

T

2

relaxation rates in a single scan, rapid enough for clinical use. These have been used for tumor characterization, epilepsy lesion detection, and for estimating variability of tissues in asymptomatic subjects. Here, we find that detailed computer models of random and systematic errors can be combined with physics-inspired optimization heuristics to discover MRF pulse sequences achieving substantially improved performance relative to MRF pulse sequences previously designed by human experts.