bluuebunny/crossref_metadata_2025 huggingface dataset:
Science underpinning the safety case of deep geological repositories − challenges in the past and in the future and how to maintain knowledge and competence during operation
Authors: Andersson Johan
Published: May 2020

Final repositories for spent nuclear fuel are approaching implementation. A prerequisite for these advancements is that it has been shown that the repository can be constructed and operated in practice in such a way that safety can be assured both during operation and over very long time scales. The success rests on decades of structured and objective-driven research and development. A key element of the research strategy has been to ensure adequate in-house competence and expertise. Also, openness and international cooperation are essential. Workable procedures for data qualification, version control as well as internal and external peer review have gained importance. When the programmes now enter a new phase of construction and operation new challenges will arise. Even if the implementing organisations would need to keep a core competence on post closure safety assessment international cooperation will be even more important on developing, sharing and managing the knowledge needed.
On particles and splines in bounded domains
Authors: Kirchhart Matthias
Published: May 2020

We propose numerical schemes that enable the application of particle methods for advection problems in general bounded domains. These schemes combine particle fields with Cartesian tensor product splines and a fictitious domain approach. Their implementation only requires a fitted mesh of the domain’s boundary, and not the domain itself, where an unfitted Cartesian grid is used. We establish the stability and consistency of these schemes in Ws,p-norms, s ∈ ℝ, 1 ≤ p ≤ ∞.
Case report of maxillary osteosarcoma with up-to date review
Authors: Soufflet Elise , Thibaut Flora
Published: May 2020

Introduction:Osteosarcoma is characterized by its rarity and malignant nature, leading to difficulty in diagnosis.Observation:We present the case of a young woman observed by her orthodontist for a recent asymptomatic intraoral mass. The first anatomo-pathological result of the sample was a benign lesion, but rapid recurrence of the lesion led to the samples being retested, resulting in the diagnosis of osteosarcoma.Discussion:The most common symptom associated with osteosarcoma is painless swelling, sometimes associated with dysesthesia and/or limited mouth opening. The radiological signs may be of the osteogenic- or osteolytic-type. After histological confirmation the treatment of this tumor requires surgical excision sometimes combined with chemotherapy.Conclusion:Osteosarcoma should be part of the differential diagnosis when a patient has an intraoral bone tumor.
Zur Huntington-Erkrankung im Kindes- und Jugendalter – Erkrankung, klinische Präsentation und Probleme der Diagnostik
Authors: Thiels Charlotte , Stahl Anna , Saft Carsten , Juckel Georg , Lücke Thomas
Published: May 2020

Die Huntington-Erkrankung (HD) ist eine autosomal-dominante neurodegenerative Erkrankung, die vornehmlich zwischen dem 30. und 50. Lebensjahr auftritt. Verursacht wird sie durch eine Genmutation auf dem Chromosom 4, welche zu einer Tripletexpansion (CAG) führt. Weniger als 10% der Betroffenen erkranken vor dem 20. Lebensjahr. Die beim Erwachsenen typischen choreatiformen Bewegungsmuster tauchen beim Jugendlichen erst im späteren Verlauf auf, können aber auch ganz fehlen. Etwa ein Drittel der Jugendlichen entwickelt eine Epilepsie.

Wir präsentieren sechs Fälle kindlicher/juveniler HD und beschreiben vergleichend zur adulten HD Erstsymptome, genetische Befunde und weitere Besonderheiten.

Die klinische Präsentation und auch der Erkrankungsverlauf der jugendlichen HD-Patienten unterscheiden sich mitunter deutlich von der adulten Form. Es imponieren initial vor allem Teilleistungsstörungen bei den Kindern sowie psychiatrische Symptome wie Depression und Aufmerksamkeitsstörungen bei den Jugendlichen.

Aufgrund der niedrigen Prävalenz juveniler HD sowie der variablen klinischen Symptomatik ist eine Diagnosestellung im Kindes- und Jugendalter schwierig und gelingt oftmals erst mit einer zeitlichen Latenz. Die frühe Diagnosestellung kann allerdings wichtig sein, insbesondere, um soziale und schulische Probleme zu entschärfen.
Veränderungen im Gangbild bei Personen mit unilateraler transtibialer Amputation – Ein systematisches Literaturreview
Authors: Proksch Lukas , Véghelyi Maria-Magdalena , Sturma Agnes
Published: May 2020

Hintergrund Eine transtibiale Amputation und die damit verbundene Versorgung mit einer Prothese führt zwangsläufig zu einem deutlich veränderten Gangbild beim Menschen, das sich in quantifizierbaren Parametern widerspiegelt. Während ein allgemeiner Konsens bzgl. der Existenz solcher Veränderungen herrscht, fehlt bislang eine systematische Zusammenfassung von Literatur, die dieses Thema abdeckt.

Ziel Einen gesammelten Überblick über die Publikationen schaffen, die sich mit den Veränderungen des Gangbildes bei Menschen mit einer transtibialen Amputation beschäftigen. Auf dieser Basis sollen Referenzwerte als Vergleichsbasis für die Analyse des Gangbildes dieser Personengruppe sowie zukünftige Forschung präsentiert werden.

Methode Es erfolgte eine systematische Literaturrecherche mittels der Datenbanken Pubmed, CINAHL und Cochrane Library nach Studien, welche Veränderungen im Gangbild bei Menschen mit transtibialer Amputation untersuchen. Diese wurden anschließend mithilfe eines Quality-Assessment-Tools bewertet, die das Gangbild beschreibenden Parameter wurden daraus extrahiert.

Ergebnisse Es konnten 13 Studien mit insgesamt 266 Teilnehmern identifiziert werden. Diese zeigen, dass Personen mit einer transtibialen Amputation eine geringere Ganggeschwindigkeit, eine geringere Kadenz, eine größere Schrittbreite sowie eine längere Standphase verglichen mit dem physiologischen Gang aufweisen.

Schlussfolgerung Es konnten Parameter für das Gangbild bei Menschen mit transtibialer Amputationen präsentiert werden, die als Vergleichsbasis im klinischen und therapeutischen Umfeld sowie für zukünftige Studien dienen. Es zeigte sich jedoch, dass die Durchführung weitaus umfangreicherer Studien notwendig ist, um allgemein gültige Normwerte erstellen zu können.
Lokal fortgeschrittenes Rektumkarzinom
Authors: Krome Susanne
Published: May 2020

Die Ergänzung der präoperativen Radiochemotherapie mit antiangiogenetischen Substanzen erhöht die Behandlungseffektivität. In der Abwägung von Nutzen und Nebenwirkungsrisiko steht besonders der günstigste Zeitpunkt für eine VEGF-Inhibition zur Diskussion. In der GEMCAD-1402-Studie erhielten Erkrankte eine Induktionschemotherapie mit oder ohne Aflibercept, eine Radiochemotherapie und dann die Operation.
Prostatakarzinom
Authors: Krome Susanne
Published: May 2020

Männer mit Diabetes haben scheinbar ein reduziertes Risiko für Prostatakarzinome. Die Annahme einer inversen Assoziation zwischen der antidiabetischen Medikation und der Tumorinzidenz bestätigte sich jetzt in einer Kohortenstudie nicht. Exponierte Patienten wurden seltener biopsiert, aber wenn Proben genommen wurden, unterschieden sich die Tumordetektionsraten nicht.
Oligometastasiertes nicht kleinzelliges Bronchialkarzinom
Authors: Krome Susanne
Published: May 2020

Etwa 7 % der Patienten mit nicht kleinzelligen Bronchialkarzinomen (NSCLC) weisen eine begrenzte Zahl von Metastasen auf. Studien belegten, dass in diesen Fällen eine längerfristige Krankheitskontrolle möglich ist. Lokaltherapien der Metastasen verlängerten das progressionsfreie und Gesamtüberleben. Bauml et al. verglichen die Überlebensraten nach einer kombinierten Lokal- und Immuntherapie mit einer historischen Kontrollgruppe, die eine lokal ablative Therapie oder eine Kombination mit Chemotherapie erhalten hatte.
The Problem with Problems: Fundamental to Applied Research Using Palladium
Authors: Watson Allan J. B.
Published: May 2020

This Account describes the development of our cross-coupling and medicinal chemistry research from its origins at the outset of my independent career through to the present day. Throughout, the decisions and motivations as well as the mistakes and pitfalls are discussed.

1 Introduction

2 Hobbies and Interests

3 Scooped before Starting

4 Opportunity from Collaboration

5 Chemoselective Suzuki–Miyaura Cross-Coupling

6 Applications to the Medicinal Chemistry Campaign

7 Autotaxin and Heterocycle Synthesis

8 ATX Hybrids and Pd(II) Speciation

9 Conclusions
Divergent Synthesis of Five-Membered Nitrogen Heterocycles via Cascade Reactions of 4-Arylfuroxans
Authors: Fershtat Leonid L. , Chaplygin Daniil A. , Ananyev Ivan V. , Makhova Nina N.
Published: May 2020

A novel method for the synthesis of a diverse series of functionally substituted five-membered heterocyclic compounds via atom-economic, regio-, and diastereoselective one-pot reaction cascade was developed. This approach involves a ring opening in 4-arylfuroxans to α-oximinoarylacetonitrile oxides followed by [3+2] cycloaddition to various dipolarophiles to afford multisubstituted isoxazoles and isoxazolines. Subsequent azole–azole rearrangement of (oximino)isoxazolines/-isoxazoles, which can be conducted in a one-pot manner, results into functionally substituted furazans formation. The developed protocol is operationally simple, proceeds in mild conditions and with high yields of target heterocyclic systems. Overall, this study represents a new mode of isoxazole and 1,2,5-oxadiazole functionalization strategy, which is useful in medicinal and materials chemistry.
Development of Sex-Stratified Prediction Models for Recurrent Venous Thromboembolism: A Danish Nationwide Cohort Study
Authors: Albertsen Ida Ehlers , Søgaard Mette , Goldhaber Samuel Zachary , Piazza Gregory , Skjøth Flemming , Overvad Thure Filskov , Larsen Torben Bjerregaard , Nielsen Peter Brønnum
Published: May 2020

Objective To optimize decision making for anticoagulant treatment duration after incident venous thromboembolism, we derived and internally validated two clinically applicable sex-specific prediction models for venous thromboembolism recurrence, discarding the traditional categorization of provoked and unprovoked venous thromboembolism.

Methods This study was based on data from Danish nationwide registries. We identified all routine care in- and outpatients with completed anticoagulant treatment for incident venous thromboembolism from 2012 through 2017. The outcome was recurrent venous thromboembolism within 2 years. Risk scores were derived using Cox regression analysis and a backward selection process on a set of 24 potential predictors. Performance was assessed through calibration and discrimination using bootstrap techniques to internally validate the scores.

Results The study included 11,519 patients. Risk scores under the joint acronym AIM-SHA-RP were developed. Age, Incident pulmonary embolism, and recent Major surgery were predictors for both sexes; Statin treatment, Heart disease and Antiplatelet treatment were predictors specifically for men, while chronic Renal disease and recent Pneumonia or sepsis were predictors specifically for women. The risk scores were well calibrated and identified a low- (< 5%), intermediate- (5–10%), and high-risk (> 10%) group for both sexes. Generally, discriminative capacities, as measured by the c-statistic, were limited.

Conclusion We developed two clinically applicable risk scores to estimate the risk of recurrent venous thromboembolism after completed anticoagulant treatment. The risk scores can potentially guide treatment duration of anticoagulation after incident venous thromboembolism but require further external validation before implemented in clinical practice.
Plasma Levels of Protein Z in Ischemic Stroke: A Systematic Review and Meta-Analysis
Authors: Słomka Artur , Kowalewski Mariusz , Żekanowska Ewa , Suwalski Piotr , Lorusso Roberto , Eikelboom John W.
Published: May 2020

The association between blood levels of protein Z (PZ) and risk of ischemic stroke remains poorly understood. We aimed to assess this potential relationship through a meta-analysis of case–control studies. PubMed, Scopus, Web of Science Core Collection, and the Cochrane Library were searched from April 1984 to April 2019. We selected case–control studies comparing PZ levels in adult patients with ischemic stroke and controls without ischemic stroke. Six case–control studies, with a total of 1,011 ischemic stroke patients and 1,128 controls, were included. Patients in the acute phase of ischemic stroke showed significantly higher levels of PZ compared with patients in the convalescent phase (standardized mean difference [SMD]: 0.289 mg/L; 95% confidence interval [CI]: 0.010, 0.569; p = 0.043). No significant differences in PZ levels were found between patients and controls in the acute phase (SMD: −0.059 mg/L; 95% CI: −0.570, 0.452; p = 0.821) or in the convalescent phase of ischemic stroke (SMD: −0.341 mg/L; 95% CI: −0.736, 0.055; p = 0.091). Subgroup analysis indicated that older patients (≥ 50 years old) had lower PZ levels than similarly aged controls. In contrast, when the study groups came from the United States and Australia or Europe no significant differences in PZ levels existed between patients and controls. No association between PZ and ischemic stroke was identified in this meta-analysis. The acute phase of ischemic stroke was associated with higher levels of PZ.
Development of Myocardial Infarction in a 12-Year-Old Female after the Use of Inhaled Salbutamol
Authors: Yozgat Can Yilmaz , Uzuner Selcuk , Temur Hafize Otcu , Ergor Serap Nur , Guliyeva Aynur , Tahaoglu Irmak , Coban Senay , Yozgat Yilmaz
Published: May 2020

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) accounts for 0.023% of all cases reported in pediatric patients. According to literature, only a handful of ALCAPA patients are able to reach adulthood. Clinical manifestations of ALCAPA range from fatigue during exercise to sudden death in adulthood. Herein, we described a 12-year-old symptomatic patient with ALCAPA who had severe chest pain after using salbutamol treatment for presumed asthma. ALCAPA is one of the curable versions of myocardial ischemia and infarction in childhood. Due to clinical findings in conjunction with electrocardiogram and echocardiography, a computed tomography scan with coronary angiography was performed and the diagnosis of ALCAPA was confirmed. We presented this case because ALCAPA-related myocardial ischemia and infarction in children are rare with only sporadic cases reported. This case illustrated the need for close monitoring and surgery as the best treatment for ALCAPA associated with myocardial infarction.
Variation in the Association between Antineoplastic Therapies and Venous Thromboembolism in Patients with Active Cancer
Authors: Giustozzi Michela , Curcio Antonio , Weijs Bob , Field Thalia S. , Sudikas Saulius , Katholing Anja , Wallenhorst Christopher , Weitz Jeffrey I. , Martinez Carlos , Cohen Alexander T.
Published: May 2020

Background Venous thromboembolism (VTE) is a major cause of death in cancer patients. Although patients with cancer have numerous risk factors for VTE, the relative contribution of cancer treatments is unclear.

Objective The objective of this study is to evaluate the association between cancer therapies and the risk of VTE.

Methods From UK Clinical Practice Research Datalink, data on patients with first cancer diagnosis between 2008 and 2016 were extracted along with information on hospitalization, treatments, and cause of death. Primary outcome was active cancer-associated VTE. To establish the independent effects of risk factors, adjusted subhazard ratios (adj-SHR) were calculated using Fine and Gray regression analysis accounting for death as competing risk.

Results Among 67,801 patients with a first cancer diagnosis, active cancer-associated VTE occurred in 1,473 (2.2%). During a median observation time of 1.2 years, chemotherapy, surgery, hormonal therapy, radiation therapy, and immunotherapy were given to 71.1, 37.2, 17.2, 17.5, and 1.4% of patients with VTE, respectively. The active cancers associated with the highest risk of VTE—as assessed by incidence rates—included pancreatic cancer, brain cancer, and metastatic cancer. Chemotherapy was associated with an increased risk of VTE (adj-SHR: 3.17, 95% confidence interval [CI]: 2.76–3.65) while immunotherapy with a not significant reduced risk (adj-SHR: 0.67, 95% CI: 0.30–1.52). There was no association between VTE and radiation therapy (adj-SHR: 0.91, 95% CI: 0.65–1.27) and hormonal therapies.

Conclusion VTE risk varies with cancer type. Chemotherapy was associated with an increased VTE risk, whereas with radiation and immunotherapy therapy, an association was not confirmed.
Does Duration Off Respiratory Support Prior to Discharge from NICU Predict Hospital Readmission among Extremely Low Gestational Age Neonates?
Authors: Pattnaik Priyam , Palmaccio Samantha , Aschner Judy , Eisenberg Ruth , Choi Jaeun , LaTuga M. Susan
Published: May 2020

Objective Our objective was to determine if the duration off respiratory support prior to discharge home from the neonatal intensive care unit (NICU) would impact hospital readmission rates among extremely low gestational age neonates (ELGAN).

Study Design In this retrospective chart review, we examined readmission rates for ELGAN admitted to the Montefiore–Weiler NICU between 2013 and 2015.

Results Of 140 infants born at <29 weeks' gestational age, 30 (21%) of these infants were subsequently readmitted within 90 days, primarily for respiratory complaints. Readmitted infants were born at an earlier gestational age (median = 26 weeks; interquartile range [IQR]: 24–27 weeks) compared to infants who did not require readmission (median = 27 weeks; IQR: 25-28 weeks), p = 0.03. Birth weights were smaller among infants who required readmission, 800 ± 248 g compared to 910 ± 214 g (p = 0.02). Infants with Hispanic ethnicity and those discharged during the spring season were likely to be readmitted. Duration off respiratory support prior to discharge did not predict 90-day readmission rates. Lower gestational age and birth weight were associated with higher rates of readmissions after NICU discharge.

Conclusion Duration off and invasiveness of respiratory support prior to discharge did not predict risk of 90-day readmission nor did discharge during months with traditionally higher prevalence of respiratory viruses.
Cardiac Myxoma as a Rare Cause of Pediatric Arterial Ischemic Stroke: Case Report and Literature Review
Authors: Tona Clarissa , Nosadini Margherita , Pelizza Maria F. , Pin Jacopo N. , Baggio Laura , Boniver Clementina , Gabrieli Joseph D. , Causin Francesco , Toldo Irene , Sartori Stefano
Published: May 2020

Background Cardiac disorders are the second leading cause of pediatric arterial ischemic stroke (AIS). Limited literature is available on pediatric AIS caused by cardiac myxoma, a rare tumor in childhood.

Methods We describe a new case of pediatric AIS due to a previously unknown atrial myxoma and we conduct a literature review on children with AIS due to cardiac myxoma.

Results We identified 41 published pediatric cases of AIS and cardiac myxoma, including ours (56% males, median age at AIS was 11 years [range: 3–18]). AIS presentation was most frequently with hemiparesis/hemiplegia (89%). Multiple brain ischemic lesions were detected in 69% of patients, and arteriopathy in 91%. Seven patients underwent mechanical thrombectomy. At AIS presentation, 73% of children had one or more of the following clinical symptoms/signs suggesting a possible underlying cardiac myxoma: Carney's complex, cardiac auscultation abnormalities, extraneurological symptoms/signs, such as skin signs (12, 38, and 65%, respectively). Cardiac myxoma was diagnosed within 72 hours in 68% of cases. Death occurred in 11%, and 40% had persistent neurological deficits.

Conclusion Neurological presentation of AIS due to cardiac myxoma is similar to that of AIS with other etiologies, although clues suggesting a possible underlying cardiac myxoma can be detected in most cases. A timely diagnosis of cardiac myxoma in patients with AIS may favor prompt identification of candidates for endovascular therapy. Therefore, we suggest that in otherwise-healthy children presenting with AIS, transthoracic echocardiography should be performed early after stroke presentation.
Patient-Reported Outcomes for Large Bipolar Osteochondral Allograft Transplantation in Combination with Realignment Osteotomies for the Knee
Authors: Zitsch Bradford P. , Stannard James P. , Worley John R. , Cook James L. , Leary Emily V.
Published: May 2020

Effective treatment for bipolar articular cartilage lesions in the knee remains a clinical challenge. Lower extremity malalignment is a risk factor for treatment failures, which can be addressed by tibial or femoral osteotomy. The purpose of this study was to compare outcomes among patients who underwent knee joint restoration by osteochondral allograft (OCA) transplantation with concurrent or staged realignment osteotomy. With Institutional Review Board approval, patients undergoing bipolar OCA transplantation with concurrent or staged distal femoral osteotomy (DFO) or high tibial osteotomy (HTO) were analyzed. Patients were categorized by osteotomy type (DFO and HTO) and timing (concurrent and staged). Patient-reported outcome measures (PROMs), revisions, failures, and complications were examined preoperatively (baseline), 3, 6, 12, and 24 months after OCA transplantation; change scores from preoperative values were used for analysis. A total of 23 patients met inclusion criteria (15 males); 13 (56.5%) received HTO (5 concurrent), while 10 (43.5%) received DFO (5 concurrent). There were no significant differences in complication rates between concurrent and staged osteotomies. Primary bipolar OCA transplantation with osteotomy was associated with successful outcomes in 70% of patients; four patients underwent revision (17.4%) and three (13.0%) failed and were treated by total knee arthroplasty. Further, the four patients undergoing revision met functional criteria for success at final follow-up, resulting in a 2-year functional survival rate of 87.4%. Aside from Patient-Reported Outcomes Measurement Information System (PROMIS) physical function, all PROMs for concurrent and staged osteotomies improved from baseline to 2 years postoperatively. Concurrent osteotomies of both types were associated with significantly lower pain scores at 12 months (p = 0.04), compared with staged osteotomies. Apart from Single Assessment Numerical Evaluation (SANE), more PROM improvement was observed for concurrent osteotomies at 2 years. Improvements in PROMs for patients undergoing OCA transplantation combined with osteotomy were observed at 2-year follow-up. PROMs for concurrent osteotomy were consistently greater than staged osteotomy, lending support to addressing lower extremity malalignment with bipolar OCA transplantation in the knee during a single surgery when possible.
Expanding Clinical Phenotype of TRAPPC12-Related Childhood Encephalopathy: Two Cases and Review of Literature
Authors: Aslanger Ayca Dilruba , Demiral Emine , Sonmez-Sahin Seyma , Guler Serhat , Goncu Beyza , Yucesan Emrah , Iscan Akın , Saltik Sema , Yesil Gozde
Published: May 2020

Biallelic mutations in the TRAPPC12 gene are responsible for early-onset progressive encephalopathy with brain atrophy and spasticity (PEBAS). To date, three different allelic variants have been reported. Next-generation sequencing allowed discovery of unique alternations in this gene with different phenotypes. We report two patients carrying TRAPPC12 variants, one previously reported and one unknown mutation, with severe neurodevelopmental delay and brain atrophy. Standard clinical examination and cranial imaging studies were performed in these two unrelated patients. In addition, whole-exome sequencing was performed, followed by Sanger sequencing for verification. The first patient, a 2-year-old boy, was found to be homozygous for the previously reported c.1880C > T (p.Ala627Val) mutation. He presented with a phenotype including severe progressive cortical atrophy, moderate cerebellar atrophy, epilepsy, and microcephaly, very similar to the previously reported cases. The second case, a 9-year-old boy, carried a novel homozygous c.679T > G (p.Phe227Val) variant and presented with mild cortical atrophy, severe cerebellar atrophy, and neither clinically manifest epilepsy nor microcephaly, which were previously considered typical findings in PEBAS with TRAPPC12 mutations. Our findings suggest that clinical and brain imaging findings might be more variable than previously anticipated; however, a larger number of observations would benefit for broader phenotypic spectrum.
The roles of attitudes towards learning and opposite sex as a predictor of school engagement: mixed or single gender education?
Authors: Erdoğdu Mustafa Yüksel
Published: May 2020

Students’ attitudes towards learning and their school engagement play important roles on the success of educational programs. Therefore, the main purpose of this research is to examine the roles of attitude towards learning and attitude towards the opposite sex as a predictor of school engagement and to determine the correlation between mixed gender education vs. single gender education and school engagement. Eight hundred and forty-three students (525 females and 318 males) who were studying in single gender or mixed gender schools were included in the research. Data were collected through School Engagement Scale, Attitude Scale towards Learning and Opposite Sex Attitude Scale. The Pearson moment correlation coefficient, multiple regression and stepwise regression were used to analyze the data. Findings showed that attitudes towards learning scores are the most predictive for school engagement. Results also showed that school engagement was higher in single gender schools for girls than in single gender schools for boys and mixed gender schools. The success of the student and the attitude towards the opposite sex were also variables that predict school engagement. The democratic attitude and education levels of parents also had important effects on students’ school engagement. The findings have important implications for educational policy making and curriculum designs. Some general recommendations were made based on the findings.
Models of good teaching practices for mobile learning in higher education
Authors: Romero-Rodríguez José-María , Aznar-Díaz Inmaculada , Hinojo-Lucena Francisco-Javier , Cáceres-Reche María-Pilar
Published: May 2020

Mobile learning is an emerging teaching methodology in the university system. Every year, the International Horizon Reports highlight the trend of implementing mobile devices in the classroom. Therefore, the Spanish university system presents the current challenge of adapting these resources to improve student learning, in line with the knowledge society in which we are immersed. This requires examples of good teaching practice. The purposes of this paper were to evaluate the mobile learning (m-learning) practices implemented by university teachers and to compile experiences on good teaching practices of m-learning developed in the classroom. A mixed method was used in which the responses of 1125 professors from 59 different universities located throughout Spain were analyzed. The APMU scale developed by the authors was applied for the detection of good teaching practices of m-learning and the structured interview for the collection of concrete experiences of good teaching practices. The results showed that the largest proportion of good teaching practices were concentrated at the University of La Laguna, University of Almeria, University of La Rioja, Camilo José Cela University and University of Seville. Furthermore, three experiences carried out by teachers who were agents of good practice were collected. Based on this, three models of good teaching practices were generated and exemplified through the concept mapping technique. Finally, the main findings and implications of the study are discussed.
Cathodoluminescent screen imaging system for seeded blob detection in toroidal plasma experiment
Authors: Micheletti P. , Baquero-Ruiz M. , Manke F. , Furno I. , Ricci P. , Fasoli A. , Bowen P. , Morais C. , Zhao W.
Published: May 2020

We designed and built a diagnostic based on a cathodoluminescent screen for the detection of turbulent plasma structures with high spatial resolution. The screen is coated with a low threshold energy cathodoluminescent powder that emits light when exposed to a plasma. The emitted light is imaged with a fast frame camera combined with an image intensifier and an optical bandpass filter. The diagnostic is used to study turbulent structures and seeded blobs. The results are analyzed with pattern recognition algorithms to track the turbulent structures and study their evolution in time.
Quantum monotone metrics induced from trace non-increasing maps and additive noise
Authors: Yamagata K.
Published: May 2020

Quantum monotone metric was introduced by Petz [Linear Algebra Appl. 244, 81–96 (1996)], and it was proved that quantum monotone metrics on the set of quantum states with trace one were characterized by operator monotone functions. Later, these were extended to monotone metrics on the set of positive operators whose traces are not always the one based on completely positive, trace preserving maps. It was shown that these extended monotone metrics were characterized by operator monotone functions continuously parameterized by traces of positive operators and did not have some ideal properties such as monotonicity and convexity with respect to the positive operators. In this paper, we introduce another extension of quantum monotone metrics that have monotonicity under completely positive, trace non-increasing maps and additive noise. We prove that our extended monotone metrics can be characterized only by static operator monotone functions from few assumptions without assuming continuities of metrics. We show that our monotone metrics have some natural properties such as additivity of direct sum, convexity, and monotonicity with respect to positive operators.
Dissociative electron attachment to benzoic acid (C7H6O2)
Authors: Zawadzki M. , Wierzbicka P. , Kopyra J.
Published: May 2020

The dissociative electron attachment (DEA) to benzoic acid (C6H5COOH) has been studied using an experimental crossed beam setup of a quadrupole mass spectrometer and a trochoidal electron monochromator. Relative partial cross sections for the DEA to produce negative ion fragments show the main channels for dissociation. The comparison of the present results with the ultraviolet photoelectron spectrum of benzoic acid [J. Meeks, A. Wahlborg, and S. P. McGlynn, J. Electron Spectrosc. Relat. Phenom. 22, 43 (1981)] implies that most DEA bands in the high energy range are due to Feshbach resonances with double occupation of diffuse Rydberg-like orbitals. The measurements are supported by density functional theory calculations of the threshold energies.
Characterizing plasma with emission tomography—Feasibility study on synthetic and experimental data
Authors: Nikolić M. , Samolov A. , Godunov A. , Vušković L. , Popović S.
Published: May 2020

We present a feasibility study on different tomographic algorithms to overcome the issues of finite sets of projection data, limited viewing angles, and noisy data, which cause the tomographic reconstruction to be an ill-posed inversion problem. We investigated three approaches: single angle Abel inversion, two angle approach, and multiple angle 2D plasma tomography. These methods were tested on symmetric and asymmetric sample functions and on experimental results from a supersonic flowing argon microwave plasma sustained in a cylindrical quartz cavity. The analysis focused on the afterglow region of the microwave flow where a plasmoid-like formation was observed. We investigated the effects of the uniform random noise added to the simulated data by applying smoothing techniques. The quality of reconstructed images was assessed by using peak signal-to-noise ratio and universal quality image measures. The results showed that the Abel inversion approach could be employed only when the system is radially symmetric, while the systems with slight asymmetry could be reconstructed with the two angle approach. In the complete absence of symmetry, full 2D tomographic reconstruction should be applied. The data analysis showed that the best results were obtained by employing either the filtered back projection or the simultaneous algebraic reconstruction technique. The total variation minimization method proved to be the best denoising technique. Each approach was used to obtain the spatial distributions of argon excited states taken at three positions along the plasmoid-like structure. The results indicated that the plasma was asymmetric with argon populating the cavity surface.
Axisymmetric magnetically enhanced discharges described in terms of flux coordinates
Authors: Brinkmann Ralf Peter , Krüger Dennis
Published: May 2020

Magnetically enhanced glow discharges and arcs are widely used in materials processing and other branches of plasma technology. An important class—including, for example, circular magnetrons, Hall thrusters, and certain ion sources—is axisymmetric devices with a poloidal magnetic field. This paper discusses the representation of such fields using the so-called flux coordinates (ψ,θ,s), a system of field aligned spatial coordinates which include the flux label ψ of a magnetic field line, the azimuth angle θ, and the arc length s. After reviewing the formalism—which finds widespread use in fusion research and plasma astrophysics—a number of special amendments are introduced to make it suitable for technological plasmas. Focus is put on the description of internal and external domain boundaries (separatrices and walls). The flux coordinates are numerically constructed for the confinement region of a circular magnetron using an analytical field model that was obtained in earlier investigations by fitting a physically plausible ansatz to Hall probe measurements. As a first application, the dynamics of the energetic electron component in a high power impulse magnetron sputtering discharge is investigated on the basis of a linear kinetic model and the corresponding confinement is calculated by solving an eigenvalue problem.
Second-order phase transition in phytoplankton trait dynamics
Authors: Held Jenny , Lorimer Tom , Pomati Francesco , Stoop Ruedi , Albert Carlo
Published: May 2020

Key traits of unicellular species, such as cell size, often follow scale-free or self-similar distributions, hinting at the possibility of an underlying critical process. However, linking such empirical scaling laws to the critical regime of realistic individual-based model classes is difficult. Here, we reveal new empirical scaling evidence associated with a transition in the population and the chlorophyll dynamics of phytoplankton. We offer a possible explanation for these observations by deriving scaling laws in the vicinity of the critical point of a new universality class of non-local cell growth and division models. This “criticality hypothesis” can be tested through new scaling predictions derived for our model class, for the response of chlorophyll distributions to perturbations. The derived scaling laws may also be generalized to other cellular traits and environmental drivers relevant to phytoplankton ecology.
Coupling of polarization orientations of the ferroelectric layers in an oxide sandwich structure
Authors: Zhu Qing , Xu Xiaofeng , Meng Meng , Yang Fang , Guo Jiandong
Published: May 2020

Mediated by the intrinsic polarization field, ferroelectric materials induce rich lattice and electronic responses associated with remarkable physical properties in their heterointerface structures. In this work, we investigate the coupling of polarization orientations of the ferroelectric BaTiO3 layers sandwiching the metallic SrRuO3 layer with different thicknesses. Measured by the electric field for switching the polarization orientation of the upper BaTiO3, it is found that the coupling of the polarization orientations increases as the SrRuO3 thickness decreases and the interaction length is determined to be 8 monolayers of SrRuO3. The transport properties of the SrRuO3 layer sensitively depend on the parallel/antiparallel orientation configuration of BaTiO3, with the resistivity changing by as much as 250% for the 6-monolayer sample. This work provides the fundamental knowledge of ferroelectric interactions in oxide sandwich structures toward their potential applications of nonvolatile memory devices.
Cell shape, and not 2D migration, predicts extracellular matrix-driven 3D cell invasion in breast cancer
Authors: Baskaran Janani P. , Weldy Anna , Guarin Justinne , Munoz Gabrielle , Shpilker Polina H. , Kotlik Michael , Subbiah Nandita , Wishart Andrew , Peng Yifan , Miller Miles A. , Cowen Lenore , Oudin Madeleine J.
Published: May 2020

Metastasis, the leading cause of death in cancer patients, requires the invasion of tumor cells through the stroma in response to migratory cues, in part provided by the extracellular matrix (ECM). Recent advances in proteomics have led to the identification of hundreds of ECM proteins, which are more abundant in tumors relative to healthy tissue. Our goal was to develop a pipeline to easily predict which ECM proteins are more likely to have an effect on cancer invasion and metastasis. We evaluated the effect of four ECM proteins upregulated in breast tumor tissue in multiple human breast cancer cell lines in three assays. There was no linear relationship between cell adhesion to ECM proteins and ECM-driven 2D cell migration speed, persistence, or 3D invasion. We then used classifiers and partial-least squares regression analysis to identify which metrics best predicted ECM-driven 2D migration and 3D invasion responses. We find that ECM-driven 2D cell migration speed or persistence did not predict 3D invasion in response to the same cue. However, cell adhesion, and in particular cell elongation and shape irregularity, accurately predicted the magnitude of ECM-driven 2D migration and 3D invasion. Our models successfully predicted the effect of novel ECM proteins in a cell-line specific manner. Overall, our studies identify the cell morphological features that determine 3D invasion responses to individual ECM proteins. This platform will help provide insight into the functional role of ECM proteins abundant in tumor tissue and help prioritize strategies for targeting tumor-ECM interactions to treat metastasis.
Toward DMRG-tailored coupled cluster method in the 4c-relativistic domain
Authors: Brandejs Jan , Višňák Jakub , Veis Libor , Maté Mihály , Legeza Örs , Pittner Jiří
Published: May 2020

There are three essential problems in computational relativistic chemistry: Electrons moving at relativistic speeds, close lying states, and dynamical correlation. Currently available quantum-chemical methods are capable of solving systems with one or two of these issues. However, there is a significant class of molecules in which all the three effects are present. These are the heavier transition metal compounds, lanthanides, and actinides with open d or f shells. For such systems, sufficiently accurate numerical methods are not available, which hinders the application of theoretical chemistry in this field. In this paper, we combine two numerical methods in order to address this challenging class of molecules. These are the relativistic versions of coupled cluster methods and the density matrix renormalization group (DMRG) method. To the best of our knowledge, this is the first relativistic implementation of the coupled cluster method externally corrected by DMRG. The method brings a significant reduction of computational costs as we demonstrate on the system of TlH, AsH, and SbH.
Cluster-based Markov model to understand the transition dynamics of a supersonic mixing layer
Authors: Li Hao , Tan Jianguo
Published: May 2020

The cluster-based Markov model (CMM) is performed on a numerically simulated supersonic mixing layer at Re = 10 400 to extract physical mechanisms. The high-dimensional state space of the supersonic mixing layer is automatically partitioned into ten relatively homogeneous clusters with representative states called centroids via the cluster analysis. The transition dynamics is conceptualized as a Markov model between centroids using the cluster transition matrix from a probabilistic point of view. A comprehensive analysis of CMM’s outcomes reveals two flow regimes: the single/double-vortex interaction (SDV) and multiple-vortex interaction (MV). The SDV regime plays the dominant role in the supersonic mixing layer, although any single centroid from the MV group carries much larger energy than that from the SDV group. More complicated patterns of vortex are well captured in an intelligent way associated with triple-vortex, quadruple-vortex, and even quintuple-vortex interaction. These vortex formations transport much more energy than the double-vortex pairing/merging. The CMM reveals a complicated set of dynamics that intermittently appear in the two regimes. The inner-circulation transition inside the SDV regime is the most probable route in the supersonic mixing layer. The MV regime can only be accessed from the SDV regime; meanwhile, it inclines to move back to the SDV regime. The transitions linking two regimes undergo large energy fluctuations. The predicted distribution of future cluster probability converges to a unique stationary distribution, which approximates the statistical probability distribution of the dataset.
Mean velocity and temperature scaling for near-wall turbulence with heat transfer at supercritical pressure
Authors: Wan Teng , Zhao Pinghui , Liu Jiaming , Wang Chaozheng , Lei Mingzhun
Published: May 2020

Compared with conventional gaseous and liquid fluids, fluids operating at supercritical pressure undergo drastic variations in thermophysical properties within a small temperature range across the pseudo-critical point. Therefore, the effect of these variations on flow and heat transfer must be studied. This paper presents direct numerical simulations (DNSs) of the turbulent heat transfer of CO2 at supercritical pressure in a fully developed channel flow between two isothermal walls. The thermophysical property tables generated from the REFPROF 9.1 database were used in this DNS. The velocity and temperature scaling and the analogy between momentum and scalar transport are comprehensively explored by using stress balance and semi-local methods. The results show that at small temperature differences, the velocity transformation developed by Trettel and Larsson [“Mean velocity scaling for compressible wall turbulence with heat transfer,” Phys. Fluids 28, 026102 (2016)] with a semi-local coordinate provides a good description of the near-wall turbulence of supercritical fluids. Upon including how large specific-heat variations affect temperature transformation, the logarithmic region of the cooled wall becomes consistent, as does the heated wall in a certain temperature range. In addition, in near-wall turbulence with small temperature differences at supercritical pressure, momentum transport is highly analogous to scalar transport.
Direct observation of surface polarization at hybrid perovskite/Au interfaces by dark transient experiments
Authors: Caram Jorge , García-Batlle Marisé , Almora Osbel , Arce Roberto D. , Guerrero Antonio , Garcia-Belmonte Germà
Published: May 2020

A distinctive feature of hybrid perovskite light-absorbing materials is the non-negligible ionic conductivity influencing photovoltaic performance and stability. Moving ions or vacancies can naturally accumulate at the outer interfaces (electrode polarization) upon biasing. Contrary to that approach, a modulation of conductive or recombination properties could manifest as an alteration in the low-frequency part of the impedance response, either producing inductive or large capacitive features. Under this last view, capacitances are not the response of polarized structures or charging mechanisms, but result from the modulation of currents. This work intends to provide pieces of evidence that assist us in distinguishing between these two dissimilar mechanisms, namely, real charge polarization and delayed current effects under bias in the dark. The analysis relays upon an experimental technique based on transient charging signals using the Sawyer-Tower circuit. Instead of applying an alternating small perturbation over a steady-state voltage (differential capacitance method), transient charging measures the resulting polarization upon a large bias step under the suppression of dc currents. Our findings reveal that real steady-state charge is indeed induced by the applied voltage in the dark, easily interpreted by means of charged real capacitors with values much larger than the geometrical capacitance of the film. The connection between that polarization and the charging of perovskite/contact interfaces is highlighted.
Direct experimental observations of the impact of viscosity contrast on convective mixing in a three-dimensional porous medium
Authors: Liyanage Rebecca , Russell Andrew , Crawshaw John P. , Krevor Sam
Published: May 2020

Analog fluids have been widely used to mimic the convective mixing of carbon dioxide into brine in the study of geological carbon storage. Although these fluid systems had many characteristics of the real system, the viscosity contrast between the resident fluid and the invading front was significantly different and largely overlooked. We used x-ray computed tomography to image convective mixing in a three-dimensional porous medium formed of glass beads and compared two invading fluids that had a viscosity 3.5× and 16× that of the resident fluid. The macroscopic behavior such as the dissolution rate and onset time scaled well with the viscosity contrast. However, with a more viscous invading fluid, fundamentally different plume structures and final mixing state were observed due in large part to greater dispersion.
Nanodomain patterns in ultra-tetragonal lead titanate (PbTiO3)
Authors: Kumar Amit , Guy Joseph G. M. , Zhang Linxing , Chen Jun , Gregg J. Marty , Scott James F.
Published: May 2020

Very recently, the discovery of ultra-tetragonal PbTiO3 thin films was reported [Zhang et al., Science, 361, 494 (2018)], in which the switchable out-of-plane polarization was seen to be almost twice that of any previously known ferroelectric. To understand more about this system and to explore features that might contribute to these remarkable functional properties, we have mapped the polarization microstructure on the nanoscale using piezoresponse force microscopy (PFM) (scan sizes less than 700 nm). Our study reveals an extremely fine-scale pattern, with individual domains typically 20–50 nm in size, all of which exhibit both out-of-plane and in-plane polarization components. In-plane vector PFM polarization maps show strongly charged quadrant-lattice domain arrays with fourfold domain wall junctions (vertices). The existence of fourfold vertices in ferroelectrics is rare but can be explained via the “Ashkin-Teller” model, in which very large interfacial lattice mismatch strains and local electric fields play a role. This ultra-tetragonal ferroelectric system was expected to contain straightforward c-axis out-of-plane 180° domains, but instead shows an extremely rich nanoscale domain tiling pattern; these unusual nanodomains may be important in facilitating the extremely high switchable polarization values previously reported.