bluuebunny/crossref_metadata_2025 huggingface dataset:
Remarkable stability of a molecular ruthenium complex in PEM water electrolysis
Authors: Bellini Marco , Bösken Jonas , Wörle Michael , Thöny Debora , Gamboa-Carballo Juan José , Krumeich Frank , Bàrtoli Francesco , Miller Hamish A. , Poggini Lorenzo , Oberhauser Werner , Lavacchi Alessandro , Grützmacher Hansjörg , Vizza Francesco
Published: March 2022

Molecular dinuclear ruthenium complexes deposited on conducting carbon serve as active sites for the evolution of hydrogen from neutral water in a Polymer Exchange Membrane (PEM) water electrolyser.
An atmospheric pressure field effect ionisation source for ion mobility spectrometry
Authors: Fateh Borkhari Arian , Moravský Ladislav , Matejčík Štefan
Published: March 2022

An atmospheric Pressure Field Effect (APFE) ionisation source for drift tube ion mobility spectrometry has been developed for operation in positive and negative polarities.
Controlling CO2 hydrogenation selectivity by Rh-based catalysts with different crystalline phases of TiO2
Authors: Cao Fenghai , Gong Nana , Ma Zixuan , Wang Xiaoxing , Tan Minghui , Wu Yingquan , Tan Yisheng
Published: March 2022

The metal–support interactions could achieve the regulation of CO2 hydrogenation selectivity by modulating the support crystal phases.
Overall design of novel 3D-ordered MEA with drastically enhanced mass transport for alkaline electrolyzers
Authors: Wan Lei , Xu Ziang , Xu Qin , Wang Peican , Wang Baoguo
Published: March 2022

A novel three-dimensionally (3D)-ordered membrane electrode assembly (MEA) based on highly porous catalyst layers with unique vertical channels, an ultrathin membrane layer and 3D interface structures was nanoengineered for alkaline electrolyzers.
DFT and TD-DFT studies of new triphenylamine-based (D–A–D) donor materials for high-efficiency organic solar cells
Authors: Babu Numbury Surendra
Published: March 2022

The DFT approach of Becke's three-parameter compound (B3LYP) was employed in all studies of triphenylamine (TPA) molecules as a donor (D) for solar cell applications in this work.
Optically reconfigurable shape memory metallo-polymer mediated by a carbolong complex and radically exchangeable covalent bond
Authors: Yang Liulin , Zhao Haibo , Xie Yulin , Ouyang Pufan , Ruan Yonghong , Chen Jiangxi , Weng Wengui , He Xumin , Xia Haiping
Published: March 2022

A novel polymer network with NIR induced shape memory behaviour and plasticity.
Three-photon absorption iridium(iii) photosensitizers featuring aggregation induced emission
Authors: Lu Xin , Xiong Chaoya , Li Bo , Du Wenli , Li Dandan , Ma Wen , Tian Xiaohe , Tian Yupeng , Zhang Qiong
Published: March 2022

Ir-H exhibits better three-photon absorption aggregation induced emission property, and thus can enhance the photodynamic therapy efficiency.
α-Branched amines through radical coupling with 2-azaallyl anions, redox active esters and alkenes
Authors: Duan Shengzu , Zi Yujin , Wang Lingling , Cong Jielun , Chen Wen , Li Minyan , Zhang Hongbin , Yang Xiaodong , Walsh Patrick J.
Published: March 2022

A mild method for the construction of α-branched amine derivatives is presented. SET processes between the Ni catalyst, redox active esters and 2-azaallyl anions generate azaallyl radicals and alkyl radicals that functionalize the alkenes.
Controllable access to trifluoromethyl-containing indoles and indolines: palladium-catalyzed regioselective functionalization of unactivated alkenes with trifluoroacetimidoyl chlorides
Authors: Yang Hefei , Wang Le-Cheng , Zhang Yu , Zheng Dongling , Chen Zhengkai , Wu Xiao-Feng
Published: March 2022

A palladium-catalyzed dual functionalization of unactivated alkenes with trifluoroacetimidoyl chlorides toward the synthesis of structurally diverse trifluoromethyl-containing indoles and indolines has been developed.
Operando isotope selective ammonia quantification in nitrogen reduction studies via gas chromatography-mass spectrometry
Authors: Ripepi Davide , Zaffaroni Riccardo , Kolen Martin , Middelkoop Joost , Mulder Fokko M.
Published: March 2022

Direct, fast and sensitive isotopic ammonia detection is key to accessing reliable NRR experiments and accelerate catalyst screening. We develop a GC-MS method to detect NH3 down to 1 ppm in the gas phase, in real-time and without external manipulation.
Multi-cavity gravito-acoustic oscillation modes in stars
Authors: Pinçon C. , Takata M.
Published: March 2022

Context. Over recent decades, asteroseismology has proven to be a powerful method for probing stellar interiors. Analytical descriptions of the global oscillation modes, in combination with pulsation codes, have provided valuable help in processing and interpreting the large amount of seismic data collected, for instance, by space-borne missions CoRoT, Kepler, and TESS. These prior results have paved the way to more in-depth analyses of the oscillation spectra of stars in order to delve into subtle properties of their interiors. This purpose conversely requires innovative theoretical descriptions of stellar oscillations.

Aims. In this paper, we aim to analytically express the resonance condition of the adiabatic oscillation modes of spherical stars in a very general way that is applicable at different evolutionary stages.

Methods. In the present formulation, a star is represented as an acoustic interferometer composed of a multitude of resonant cavities where waves can propagate and the short-wavelength JWKB approximation is met. Each cavity is separated from the adjacent ones by barriers, which correspond to regions either where waves are evanescent or where the JWKB approximation fails. Each barrier is associated with a reflection and transmission coefficient. The stationary modes are then computed using two different physical representations: (1) studying the infinite-time reflections and transmissions of a wave energy ray through the ensemble of cavities or (2) solving the linear boundary value problem using the progressive matching of the wave function from one barrier to the adjacent one between the core and surface.

Results. Both physical pictures provide the same resonance condition, which ultimately turns out to depend on a number of parameters: the reflection and transmission phase lags introduced by each barrier, the coupling factor associated with each barrier, and the wave number integral over each resonant cavity. Using such a formulation, we can retrieve, in a practical way, the usual forms derived in previous works in the case of mixed modes with two or three cavities coupled though evanescent barriers, low- and large-amplitude glitches, and the simultaneous presence of evanescent regions and glitches.

Conclusions. The resonance condition obtained in this work provides a new tool that is useful in predicting the oscillation spectra of stars and interpreting seismic observations at different evolutionary stages in a simple way. Practical applications require more detailed analyses to make the link between the reflection-transmission parameters and the internal structure. These aspects will be the subject of a future paper.
Efficacy of two endectoparasiticide products combining fipronil and (S)-methoprene or esafoxolaner with eprinomectin and praziquantel against fleas and intestinal helminths in cats naturally infested in Brazil
Authors: Cutolo Andre A. , Jardina Debora T.G. , De Vito Gabriela G. , Grisi do Nascimento Cristiano , Heidmann Maycon Junior , Ferreira Nantes José Dirceu , Bassetto Karolyne Vieira , Chagas Isabella Cristina , Pereira Junior Edgar Ferreira , de Castro Bruno Gomes , Tielemans Eric
Published: March 2022

Eprinomectin and praziquantel, nematodicide and cestodicide compounds, are both combined with the insecticide and acaricide compounds fipronil and (S)-methoprene in Frontline® Protect/Broadline®, or esafoxolaner in NexGard® Combo. These topical feline endectoparasiticide products were tested for efficacy against fleas and intestinal helminths in a field trial in Brazil. Flea- and/or helminth-infested domestic cats were treated twice at a monthly interval following label instructions: 160 cats with Frontline® Protect/Broadline® and 165 cats with NexGard® Combo. The flea and intestinal helminth infestations were evaluated using comb counts and copromicroscopy, respectively before first treatment for baseline value, then 9 and 30 days after each treatment for fleas, and 9 days after each treatment for helminths. Multiparasitism was very frequent at baseline, as amongst the 325 included cats, 295, 280, 86 and 93 cats were at least infested with Ctenocephalides fleas, Ancylostoma, Toxocara and Dipylidium caninum, respectively. Efficacies were calculated by comparing the geometric means at baseline and at post-treatment timepoints for each parasite genus/species. Inclusive of both products and of all evaluation timepoints, the Ctenocephalides, Ancylostoma, Toxocara and D. caninum efficacies were at least 98.3%, 99.8%, 99.8% and 96.3%, respectively. No adverse reactions were observed, except for a few instances of mild, transient, and self-resolving hypersalivation occurring on the day of treatment in both groups. This field trial demonstrated high-level efficacy of Frontline® Protect/Broadline® and NexGard® Combo against major parasites of cats in Brazil.
Integrating Combined First Trimester Screening for Preeclampsia into Routine Ultrasound Examination
Authors: Trottmann Fabienne , Mollet Anne Elena , Amylidi-Mohr Sofia , Surbek Daniel , Raio Luigi , Mosimann Beatrice
Published: March 2022

Introduction The Fetal Medicine Foundation (FMF) London has developed a first trimester screening algorithm for preeclampsia (PE), based on maternal characteristics and past risk
factors, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), and placental growth factor (PlGF). The aim of this study was to determine the feasibility of integrating PE
screening into routine practice.

Material and Methods All pregnancies with a fetal crown-rump length of 45 – 84 mm presenting to our ultrasound department between January 2014 and September 2020 were included in
this analysis. Screening for PE was offered to singleton pregnancies only. The number of screening tests performed in the eligible population was assessed and the reasons for missed
screenings identified with the help of the electronic clinical database. SPSS Statistics 25 and GraphPad version 8.0 for Windows were used for statistical analysis.

Results 6535 pregnancies were included, 4510 (69.0%) of which were screened for PE. The percentage of patients being offered PE screening increased over the years from 63.1 to 96.7%
(rs = 0.96; p = 0.003), while the rate of screenings performed in eligible patients remained stable at a median [range] of 86.2% [78.0 – 91.8%] (p = ns). 2025 (31.0%)
pregnancies were not screened for PE, 1306 (64.5%) because they were not eligible for screening. 145 (2.2%) women explicitly declined PE screening; their background risk was lower than that
of women who accepted screening.

Conclusion Our study shows that integration of PE screening into the routine first trimester ultrasound scan is feasible and widely accepted by pregnant women and health care
providers.
Versorgungsrealität stationär behandelter Patienten mit proximaler Humerusfraktur – Eine Analyse auf Basis von GKV-Daten
Authors: von Dercks Nikolaus , Hepp Pierre , Theopold Jan , Henkelmann Ralf , Häckl Dennis , Kossack Nils
Published: March 2022

Die proximale Humerusfraktur ist eine der häufigsten Frakturen des älteren Menschen. Während epidemiologische Faktoren gut untersucht wurden, ist der Einfluss einer proximalen
Humerusfraktur auf die Morbidität, Mortalität und assoziierten Kosten unzureichend analysiert.

Auf der Basis von 4,1 Mio. GKV-Versicherten wurden für den Zeitraum 2012–2016 Patienten mit (Studienpopulation, SP) und ohne (Vergleichsgruppe, VG) proximale Humerusfraktur (pHF) in
Hinblick auf Komorbidität, Rehospitalisierung, Mortalität, Medikamenten- und Heilmittelbedarf sowie Anzahl und Facharztkontakten verglichen.

6068 Patienten der SP erfüllten die Ein- und Ausschlusskriterien (Alter 69,4 ± 14,3 Jahre; m : w = 28,2% : 71,8%). 4781 Patienten (78,8%) erhielten eine operative, 1287 Patienten (21,2%)
eine konservative Versorgung der pHF. Folgehospitalisierungen und Hausarztbesuche traten bei der SP vs. VG häufiger auf (p < 0,01). Facharztkontakte nach pHF variierten nach Fachgebiet
ebenso wie behandelte Neuerkrankungen. Typische Fachrichtungen für Vorsorgeuntersuchungen waren signifikant seltener (Gynäkologie p < 0,01, Pathologie p < 0,01, Dermatologie
p < 0,01). Nach pHF lagen die Kosten der SP für Arzneimittel (2490,76 ± 1395,51 € vs. 2167,86 ± 1314,43 €; p = 0,04), Heil- (867,01 ± 238,67 € vs. 393,26 ± 217,55 €; p < 0,01) und
Hilfsmittel (821,02 ± 415,73 € vs. 513,52 ± 368,76 €; p < 0,01) signifikant über der VG. Die 2-Jahres-Überlebenswahrscheinlichkeit nach pHF ist bei der SP geringer als in der VG
(p < 0,01).

Die Ergebnisse zeigen, dass nach proximaler Humerusfraktur die Morbidität und Mortalität sowie die Kosten der mit der Verletzung assoziierten Versorgung steigen. Vorsorgerelevante
Untersuchungen und Behandlungen werden reduziert in Anspruch genommen. Versorgungskonzepte von Patienten mit proximalen Humerusfrakturen sollten in Zukunft nicht nur in Hinblick auf
funktionelle Scores und Komplikationsraten, sondern auch bez. Lebensqualität und Erhalt der allgemeinen Gesundheit optimiert werden.
Psychiatrieseelsorge als Begegnung und Begleitung in und nach dem Klinikaufenthalt
Authors: Enz Martin
Published: March 2022

Patienten in psychiatischen Kliniken werden in Deutschland von berufenen und ausgebildeten Seelsorgern der beiden großen Konfessionen begleitet. Pfarrer Martin Enz, Psychatrieseelsorger in Ulm, setzt sich dafür ein, dass diese Patienten auch nach dem Klinikaufenthalt von Seelsorgern begleitet werden, so sie es wünschen.
Venous Thromboembolism Risk Assessment Models in Obstetrics: A Review of Current Practices and Future Directions
Authors: Francis Antonia P. , Alshowaikh Khadija , Napoleon Melissa , Al-Khan Abdulla , Kayaalp Emre
Published: March 2022

Pregnancy is a major risk factor for venous thromboembolism (VTE) and its associated complications. The hypercoagulable state in both the antenatal and postnatal periods contributes to thromboembolism and continues to be a leading cause of maternal morbidity and mortality worldwide. The non-specific signs and symptoms of VTE in pregnancy and the lack of specific Risk Assessment Models (RAMs) propose a diagnostic challenge in the obstetric population. This review aims to discuss and compare existing RAMs and highlights the important challenges of using established RAMs in obstetric patients. It also emphasizes the importance of enhancing and individualizing RAMs in obstetrics to improve maternal healthcare.

Key Points
Rh(III)-Catalyzed Tandem [4+2] Annulation To Construct Functional Dihydroisoquinolinones
Authors: Dong Lin , Yang Jia-Hui
Published: March 2022

A highly efficient Rh(III)-catalyzed tandem [4+2] annulation to construct functional dihydroisoquinolinone derivatives with an alkenyl side chain by insertion into an N–O bond as an internal oxidation process has been achieved. A wide range of 1,3-dienes as the coupling partners makes this simple methodology even more useful.
Maternal Perinatal Telemonitoring in the Context of the Coronavirus Disease 2019 Pandemic in a Tertiary Health Center in Peru
Authors: Novoa Rommy H. , Meza-Santibañez Luis , Melgarejo Wilder E. , Huang-Yang Xin , Guevara-Ríos Enrique , Torres-Osorio Juan , Aponte-Laban Rosa , Jáuregui-Canchari Vladimir , Rodríguez-Hilario Noe , Ventura Walter
Published: March 2022

Objective This study aimed to describe the characteristics of a telemonitoring program that was rapidly implemented in our institution as a response to the coronavirus disease 2019 (COVID-19) pandemic, as well as the maternal and perinatal outcomes of women who attended this program.

Study Design Retrospective study of patients via phone-call telemonitoring during the peak period of the COVID-19 pandemic (May 2020–August 2020). Maternal and perinatal outcomes were collected and described. Health providers' satisfaction with the telemonitoring program was assessed via an email survey.

Results Twenty-three (69.7%) health providers answered the survey. The mean age was 64.5 years, 91.3% were OB/GYN (obstetrician-gynecologist) doctors, and 95% agreed that telemonitoring is an adequate method to provide health care when in-person visits are difficult. The 78.7% of scheduled telemonitoring consultations were finally completed. We performed 2,181 telemonitoring consultations for 616 pregnant women and 544 telemonitoring consultations for puerperal women. Other medical specialties offering telemonitoring included gynecology, reproductive health, family planning, cardiology, endocrinology, and following up with patients with reactive serology to severe respiratory syndrome coronavirus 2 (SARS-CoV-2). The majority of the population attending our telemonitoring program were categorized as the lowest strata, i.e., III and IV, according to the Human Development Index, and approximately 42% were deemed as high-risk pregnant women. Additionally, we reported the perinatal outcomes of 424 (63%) pregnant women, the most relevant finding being that approximately 53% of them had cesarean sections.

Conclusion Telemonitoring is an adequate method of continuing the provision of prenatal care when in-person visits are difficult in situations such as the COVID-19 pandemic. Telemonitoring is feasible even in institutions with no or little experience in telemedicine. The perinatal outcomes in women with telemonitoring seem to be similar to that in the general population.

Key Points
Exploration of Differences between Women Who Do and Do Not Disclose Their Marijuana Use during Pregnancy
Authors: Murnan Aaron W. , Keim Sarah A. , Klebanoff Mark A.
Published: March 2022

Objective This study aimed to explore demographic and health-related factors that may differentiate women who do and do not disclose their marijuana use during pregnancy.

Study Design The current study is a secondary analysis of data from a prospective cohort of pregnant women identified as using marijuana during pregnancy via a variety of assessment tools including self-report, urine screen, and obstetrics record abstraction. The cohort included a convenience sample of women recruited from several antenatal clinics at The Ohio State University Wexner Medical Center (OSUWMC). To be eligible, women needed to be within the first or second trimester of their pregnancy, 16 to 50 years of age, able to communicate in English, and intended to deliver at OSUWMC. Chi-square, independent samples t-tests, and logistic regression analyses were used to explore differences between those who did and did not disclose their use in relation to physical and mental health diagnoses, adverse experiences, use of other substances, and demographics.

Results Women who used marijuana during their pregnancy and had mental/physical health data available comprised the current sample (n = 109). Women who attended college were more likely to disclose their marijuana use compared with women who did not attend college (p < 0.001). Women who experienced homelessness (p < 0.01) or self-reported alcohol use during pregnancy (p < 0.001) were significantly more likely to disclose their marijuana use.

Conclusion Findings, suggesting disclosure of other substance use and adverse experiences, such as homelessness, may increase the likelihood that pregnant women will voluntarily disclose their marijuana use to providers. Findings did not reflect racial differences nor significant differences in mental/physical health status among women based on their disclosure. Future research with larger datasets is needed to build on these findings by confirming results, as well as exploring additional factors, that may more effectively differentiate women who are unlikely to disclose their prenatal marijuana use from those who do disclose their use.

Key Points
Heteroatom-Tethered ω-Alkenylallylboronates: Stereoselective Synthesis of Heterocyclic Derived Alcohols
Authors: Barrio Pablo , Garnes-Portolés Francisco , Miguélez Rubén , Grayson Matthew N.
Published: March 2022

The synthesis of ω-alkenylallylboronates using a heteroatom tether to join both functional groups is described for the first time. Then, these unprecedented compounds were used in a tandem Brønsted acid catalyzed allylboration/ring-closing metathesis (RCM) reaction affording heterocyclic derived alcohols as single diastereoisomers. The low enantioselectivity observed in the asymmetric version using a chiral phosphoric acid catalyst was studied theoretically.
Postinfectious Olfactory Complaints: A Follow-up Study
Authors: Passali Giulio Cesare , Passali Desiderio , Ciprandi Giorgio
Published: March 2022

Introduction Acute upper respiratory infection (AURI) is the most common cause of postinfectious olfactory dysfunction (PIOD).

Objective We investigated the prevalence of PIOD in a large group of patients reporting persistent smell impairment perception after the AURI resolution.

Methods Olfactometry was performed within 1 month after the common cold resolution and after 1 year in 467 (299 males, mean age 41.7 years) outpatients. The Sniffin' Sticks olfactory test (Burghart instruments, Wedel, Germany) was used.

Results Anosmia was documented in 28 (6%) patients, hyposmia in 33 (7%), and cacosmia in 55 (11.7%). After 1 year, PIOD improved in 82 (79.6%) patients re-tested.

Conclusion The current study demonstrated that persistent olfactory dysfunction is a relevant symptom in patients with AURI, even though many patients had normal olfactometry. Thus, smell impairment deserves careful attention and requires objective documentation.
Bone-Anchored Hearing Implants: Surgical and Audiological Comparison of Different Surgical Techniques
Authors: Topcu Merve Torun , Mutlu Basak , Celik Serdal , Celikgun Bahtiyar , Mutlu Ahmet , Kalcioglu M. Tayyar
Published: March 2022

Introduction The bone-anchored hearing implant system (BAHS) is an effective amplification system that transmits the sounds received by an external operating system to the inner ear by bypassing the middle ear placed in the temporal bone.

Objective This study compares the results of patients who underwent bone-anchored hearing implant system (BAHS) surgery using two different surgical methods in terms of preoperative and postoperative complications, surgical time, audiological findings, and patient satisfaction.

Methods The results of 22 patients who underwent BAHS were evaluated retrospectively from video records and audiological results, The Turkish Version of the Glasgow Benefit Inventory (GBI) questionnaire were evaluated. Two different surgical approaches were used for implantation: the linear incision technique (n = 9) and the punch technique (n = 13).

Results Mean surgical durations were 9.67 ± 2.85 and 47.65 ± 6.13 minutes for Groups A and B, respectively, and these were significantly different (p < 0.001). There were no significant differences between the groups' speech recognition scores for a signal-to-noise ratio (SNR) of +5 (p = 0.173), SNR of 0 (p = 0.315), or SNR of -5 (p = 0.360) and results of the GBI scores.

Conclusion The punch technique has a significant advantage due to a shorter surgery duration without increased surgical complications. Additionally, the punch technique showed no significant difference in hearing performance or satisfaction compared with linear incision.
Masterstudium Management für Technik im Gesundheitswesen: Letzte Gelegenheit für die Teilnahme am bewährten Programm
Authors: Thalmayr Maria
Published: March 2022

Mit dem Hochschullegistikpaket steht Österreich eine umfassende Reform für die hochschulische Weiterbildung ins Haus. Das Masterstudium Management für Technik im Gesundheitswesen wird daher grundlegend überarbeitet und startet im Sommersemester 2023 zum letzten Mal in der aktuellen Form.
A bibliometric analysis of the internationalisation of political science in Europe
Authors: Carammia Marcello
Published: March 2022

Based on data on 67,000 articles published in 100 high-impact journals in the twenty years between 2000 and 2019, I analyse the scientific contribution of European political science scholarly communities in the global context. The scholars contributing to the global scientific production are largely concentrated in a few countries, with the US and UK alone accounting for more than half of the articles published in high-impact journals. However, the tendency is towards increasing diversity in the geographic basis of the international scientific production; and European countries are central to this change. Contributing to international collaborative publications has been a key engine of the increased scientific production of scholars based in Europe. This was a generalised global tendency, and a spectacular one for certain national scholarly communities. The network analysis of international collaborations points to the consolidation of three clusters within a growing and increasingly dense network. The US, followed by the UK, are central to a global cluster of collaborations. European countries are primarily clustered in two groups: a larger and growing cluster; and a smaller but even more integrated, highly productive and connected cluster of scholars based in seven northern European countries. All bibliometric indicators consistently point to a generalised growth in the output and internationalisation of the scientific contribution provided by the European political science community.
Identifying the shifting sources to predict the dynamics of COVID-19 in the U.S.
Authors: Wang Yanchao , Zhong Lu , Du Jing , Gao Jianxi , Wang Qi
Published: March 2022

Mobility restriction is a crucial measure to control the transmission of the COVID-19. Research has shown that effective distance measured by the number of travelers instead of physical distance can capture and predict the transmission of the deadly virus. However, these efforts have been limited mainly to a single source of disease. Also, they have not been tested on finer spatial scales. Based on prior work of effective distances on the country level, we propose the multiple-source effective distance, a metric that captures the distance for the virus to propagate through the mobility network on the county level in the U.S. Then, we estimate how the change in the number of sources impacts the global mobility rate. Based on the findings, a new method is proposed to locate sources and estimate the arrival time of the virus. The new metric outperforms the original single-source effective distance in predicting the arrival time. Last, we select two potential sources and quantify the arrival time delay caused by the national emergency declaration. In doing so, we provide quantitative answers on the effectiveness of the national emergency declaration.
Experimental observation of transition from type I to type II ultrafast demagnetization dynamics in chemically disordered Fe60Al40 thin film, driven by laser fluence
Authors: Arslan M. , Bese C. , Tabak Z. , Bozdag T. , Duman E. , Yaglioglu H. G.
Published: March 2022

Understanding of the laser-induced ultrafast demagnetization dynamics is one of the most challenging and hot topics in magnetism research due to its potential applications in magnetic storage devices and the field of spintronics. Recently, a laser-induced switching of ferromagnetism, driven by a disorder–order transition on FeAl thin films, has been experimentally demonstrated. The switching of ferromagnetic ordering by ultrafast laser pulses in FeAl thin films may open new possible applications of this material such as magnetic data storage and manipulation. Since the speed of the magnetic switching of magnetic states in thin films is one of the critical parameters for these applications, here we used time resolved magneto-optical Kerr measurements to investigate the demagnetization dynamics of Fe60Al40 thin films at room temperature. We have for the first time observed a clear transition from one-step dynamics (type I) to two-step (type II) dynamics in the same material by increasing pump laser fluence. This experimental observation may give a strong confirmation that the ultrafast demagnetization process can be treated as a thermal process and is driven by the difference between temperatures of the electron and spin systems.
Influence of time-delayed feedback on the dynamics of temporal localized structures in passively mode-locked semiconductor lasers
Authors: Seidel Thomas G. , Javaloyes Julien , Gurevich Svetlana V.
Published: March 2022

In this paper, we analyze the effect of optical feedback on the dynamics of a passively mode-locked ring laser operating in the regime of temporal localized structures. This laser system is modeled by a set of delay differential equations, which include delay terms associated with the laser cavity and the feedback loop. Using a combination of direct numerical simulations and path-continuation techniques, we show that the feedback loop creates echoes of the main pulse whose position and size strongly depend on the feedback parameters. We demonstrate that in the long-cavity regime, these echoes can successively replace the main pulses, which defines their lifetime. This pulse instability mechanism originates from a global bifurcation of the saddle-node infinite-period type. In addition, we show that, under the influence of noise, the stable pulses exhibit forms of a behavior characteristic of excitable systems. Furthermore, for the harmonic solutions consisting of multiple equispaced pulses per round-trip, we show that if the location of the pulses coincides with the echo of another, the range of stability of these solutions is increased. Finally, it is shown that around these resonances, branches of different solutions are connected by period-doubling bifurcations.
Atomic-level smoothing of glass and silicon surfaces by water polishing with an acrylic polymer plate
Authors: Guo Jianli , Matsuzawa Yusuke , Yamaguchi Gota , Mimura Hidekazu
Published: March 2022

Polishing techniques have been used since antiquity but remain important in high-value manufacturing processes in optics and semiconductor fields. State-of-the-art polishing enables the production of atomically flat surfaces of even advanced materials, such as diamond, SiC, and GaN, by exploiting the exceptional chemical characteristics of particle surfaces, fluid solutions, and pad surfaces. Although various effective chemical reactions are employed, chemical reactivities of organic polymer surfaces have not been thoroughly explored. We demonstrate a water-only and slurry-less polishing technique using an acrylic polymer plate. We investigated the possibility of glass processing with several polymer materials and found that normal acrylic polymers have remarkable properties for polishing. Glass and silicon surfaces with atomic-level flatness can be produced using only an acrylic polymer plate and water. We believe that the developed polishing methods will become popular in the future because they are simple and cost-effective processes.
Real time investigation of double magnetic tunnel junction with a switchable assistance layer for high efficiency STT-MRAM
Authors: Sanchez Hazen D. , Teixeira B. M. S. , Salomoni D. , Auffret S. , Vila L. , Sousa R. C. , Prejbeanu I. L. , Buda-Prejbeanu L. D. , Dieny B.
Published: March 2022

This work reports experimental confirmation of the working principles of a double magnetic tunnel junction (DMTJ) to achieve highly efficient spin-transfer-torque (STT) switching. This concept uses a magnetically switchable assistance layer (ASL) acting as a top perpendicular spin polarizer. The STT-induced switching dynamics were described by macrospin simulations, while the magnetic and electrical properties of the devices were investigated in switching experiments. The reversal dynamics of the storage layer/ASL coupled system were validated by time-resolved measurements of the device resistance during write operation, confirming that the storage layer is subjected to additive STT contributions both from the reference layer and the ASL throughout its parallel-to-antiparallel and antiparallel-to-parallel transitions. The STT efficiency of the ASL-DMTJ was compared to that of single MTJ stacks comprising the same storage layer and no assistance layer. The figure of merit ∆/Ic (stability/critical current) was found to nearly double in devices of 80 and 100 nm diameter, with a smaller 30% increase obtained for 50 nm diameter cells.
Interventions and their efficacy in controlling the spread of an epidemic: A numerical study
Authors: Shukla Shantanu , Tiwari Ishant , Sarin Pradeep , Parmananda P.
Published: March 2022

The effect of interventions on the progression of an epidemic is studied by numerically modeling attributes, such as lockdowns and vaccinations within a stochastic, highly connected, mobile community using an agent-based model. Based on real life assumptions, we are able to gauge the effectiveness of various strategies to contain the spread of a disease through a population. The fine-tuning of control parameters makes the model coherent with real life scenarios and robust from a policy-maker’s perspective.
A classical analog of the quantum Zeeman effect
Authors: Jamet P. , Drezet A.
Published: March 2022

We extend a recent classical mechanical analog of Bohr’s atom consisting of a scalar field coupled to a massive point-like particle [P. Jamet and A. Drezet, “A mechanical analog of Bohr’s atom based on de Broglie’s double-solution approach,” Chaos 31, 103120 (2021)] by adding and studying the contribution of a uniform weak magnetic field on their dynamics. In doing so, we are able to recover the splitting of the energy levels of the atom called Zeeman’s effect within the constraints of our model and in agreement with the semiclassical theory of Sommerfeld. This result is obtained using Larmor’s theorem for both the field and the particle, associating magnetic effects with inertial Coriolis forces in a rotating frame of reference. Our work, based on the old “double solution” theory of de Broglie, shows that a dualistic model involving a particle guided by a scalar field can reproduce the normal Zeeman effect.
Planar Hall effect and large anisotropic magnetoresistance in a topological superconductor candidate Cu0.05PdTe2
Authors: Feng Guolin , Huang Hui , Wu Zhiqiang , Han Yuyan , Zhang Changjin
Published: March 2022

We report the observation of a large anisotropic magnetoresistance (AMR) and planar Hall effect (PHE) in a topological superconducting candidate Cu0.05PdTe2. The AMR and PHE data in Cu0.05PdTe2 can be well explained by the semiclassical theory, confirming that the magneto-transport behaviors of the Cu0.05PdTe2 superconductor are related to its topological nature. The AMR ratio in Cu0.05PdTe2 is one order of magnitude larger than those in traditional ferromagnetic metals. The present results suggest that Cu0.05PdTe2 is a promising material in future magnetoresistive devices with low power consumption.
Inverse Compton scattering of the ITG turbulence by energetic ions
Authors: Marchenko V. S.
Published: March 2022

Linearly stable toroidal Alfvén eigenmodes (TAEs) can be non-linearly excited by the ion temperature gradient mode turbulence having frequencies an order of magnitude lower than TAE. An excitation mechanism is the inverse Compton scattering by energetic ions, i.e., the inverse non-linear Landau damping accompanied by a frequency increase in the scattered waves. This effect can be responsible for excitation of the stable TAE by turbulence observed in numerical simulations [Di Siena et al., Nucl. Fusion 59, 124001 (2019)]. Such non-linear coupling to stable TAE via energetic ions provides an efficient energy sink for turbulence and can explain strong reduction of the thermal ion heat flux in the presence of fast ions observed in gyro-kinetic modeling [Citrin et al., Phys. Rev. Lett. 111, 155001 (2013)].
Deconvoluting the energy transport mechanisms in all-inorganic CsPb2Br5/CsPbBr3 perovskite composite systems
Authors: Wang Yunpeng , Wang Fei , Zhu Gangbei , Quan Quan , Lai Zhengxun , Meng You , Fan Yi , Yip SenPo , Zhao Dongxu , Ho Johnny C.
Published: March 2022

CsPb2Br5/CsPbBr3 composite systems have received considerable attention among numerous lead halide perovskite materials due to their significantly enhanced photoluminescence intensity and stability against moisture. However, the luminescence mechanism of CsPb2Br5 based materials remains controversial, which significantly hinders the further material design and utilization for optoelectronic devices. In this work, to deconvolute their luminescent mechanisms, high-quality CsPb2Br5 crystals without any undesired by-products and impurities have been first prepared by a microwave-assisted synthesis method. The luminescence-inactive characteristics of the material are then confirmed by the steady-state absorption, photoluminescence, transient absorption spectra, and time-resolved terahertz spectroscopy. The prepared CsPb2Br5 crystals exhibit excellent crystallinity and enhanced thermal stability, particularly that they can maintain their crystalline structures in polar organic solvents. By simply manipulating the ratios of different precursor materials, it is witnessed that the green emission comes from the CsPbBr3 adhered, nucleated, and grown on the CsPb2Br5 crystals. Ultrafast transient absorption measurements in visible and terahertz spectral regions reveal that with the help of phonon scattering-assisted hopping at interfacial states, intersystem crossing dominates the electron transfer process in the composite crystals. As a result, the CsPb2Br5 and CsPbBr3 interact extensively with each other. Meanwhile, the Auger recombination rate and the defect-related non-radiative process are suppressed in the composite crystals, thereby enhancing the fluorescence of composite crystals. This work has not only deconvoluted the controversial and unclear luminescent mechanisms of CsPb2Br5 materials but also established a pathway to design and enhance the fluorescence of materials for technological applications.
Adsorption of methyl orange, acid chrome blue K, and Congo red dyes on MIL-101-NH2 adsorbent: Analytical interpretation via advanced model
Authors: Aouaini Fatma , Bouaziz Nadia , Khemiri Noura , Alyoussef Haifa , Nasr Samia , Ben Lamine Abdelmottaleb
Published: March 2022

A synthesized MIL-101-NH2 has been used as an adsorbent to analyze Congo red (CR), methyl orange (MO), and acid chrome blue K (AC) dye adsorption phenomena. This investigation, based on statistical physics treatment, applied the double layer model with two energies to understand dye adsorption on three samples, namely, MIL-101-NH2-1, MIL-101-NH2-2, and MIL-101-NH2-3, at T = 298 K. Modeling results indicated that dye adsorption occurred via a mixed adsorption orientation for CR and MO dyes and a non-parallel orientation for AC dye on the MIL-101-NH2 surface. Dye uptake quantities varied from 2534.4 to 3440 mg/g for CR dye, 240.4 to 490.8 mg/g for MO dye, and 277 to 293 mg/g for AC dye. Thus, the highest adsorption amount appeared in the case of CR dye. Interpretation of the calculated energies showed that adsorption of the dyes on MIL-101-NH2 is a physisorption phenomenon, which could be controlled through energetic parameters obtained via numerical findings using the statistical double layer model. Moreover, the expression of the model is exploited to investigate the thermodynamic functions, such as internal energy.
Fishtail effect and the vortex phase diagram of high-entropy alloy superconductor
Authors: Gao Lingling , Ying Tianping , Zhao Yi , Cao Weizheng , Li Changhua , Xiong Lin , Wang Qi , Pei Cuiying , Ge Jun-Yi , Hosono Hideo , Qi Yanpeng
Published: March 2022

High-entropy alloy (HEA) is an attracting topic raising in materials science and condensed matter physics. Although several types of superconductors have been discovered in HEAs, the critical currents (Jc) of HEA superconductors require further study. Here, we study the current-carrying ability of (TaNb)0.7(HfZrTi)0.5 HEA at various heat treatment conditions. We obtained the high upper critical field and large current carrying ability, which point to the potential applicability of the HEA superconductor under extreme conditions. Interestingly, the fishtail or the second peak effect was found in HEA superconductors, and the position of the vortex pinning force shows a maximum at 0.72 of the reduced field, which is quite different from the cuprates and iron-based high-Tc superconductors. Together with the resistive measurements, the vortex phase diagram is obtained for the HEA superconductor.
Research on a material for hydrogen purifying and flux controlling with application to space active hydrogen-masers
Authors: Li Qi , Hou Xueling , Dai Jiayu , Chen Zhichun , Liu Tiexin , Yang Hao
Published: March 2022

The Space Active Hydrogen-Maser (SAHM) can be used for the Space Very Long Baseline Interferometry Project to improve the resolution of the space astronomical telescope. The standard frequency signals provided by the SAHM have their stability dependent on the flux of effective H atoms. Therefore, a nickel (Ni) tube, one end closed, has been designed in this paper for the SAHM as a hydrogen (H2) purification and flux control device. Mechanisms of the H2 purification and flux control by a Ni tube were studied. H2 flux and ΔU, as a function of an input current, are given by experimental analyses. The diffusion activation energy of atomic H is much less than that of other atoms under the same conditions in Ni. The H atoms reversibly diffuse in Ni, and their diffusion speed has a high response to temperature. Experimental research shows that when the temperature of the tube was changed (from 27 to 700 °C), by an input heating electrical current (from 0 to 3.5 A), the H2 flux varied from 0 to 9.18 × 10−10 mol/s and no change in the phase structure of Ni. The data of flux should be useful for the frequency stability performance research of the SAHM. In addition, no phase change of the material indicates a stable performance of the tube for H-purifying and flux controlling. Finally, the above advantages make it a promising candidate for the reliability of the SAHM.
Magnetic thickness measurement for various iron steels using magnetic sensor and effect of electromagnetic characteristics
Authors: Tsukada Keiji , Hayashi Minoru , Kawakami Taisei , Adachi Shoya , Sakai Kenji , Kiwa Toshihiko , Ishikawa Toshiyuki , Saari Mohd Mawardi , Hori Kengo , Hisazumi Kazumasa , Tominaga Tomonori
Published: March 2022

The diagnosis and prevention of the deterioration of iron-steel infrastructure has become an important social issue in recent years. The thickness measurement technique (extremely low-frequency eddy current testing (ELECT)) using a magnetic sensor for detecting steel corrosion at extreme frequency ranges has been previously reported. Using the calibration curves based on the correlation between the phase of the detected magnetic signal and the plate thickness, the plate thickness reduction caused by corrosion can be estimated from the detected phase signal. Iron-steel materials have large changes in electromagnetic characteristics; therefore, the reference calibration data for each type of iron-steel are required for plate thickness estimation. In this study, the effect of electromagnetic characteristics on the magnetic thickness measurement was investigated to improve the thickness estimation. Four types of iron-steel plates (SS400, SM400A, SM490A, and SMA400AW) with thicknesses ranging from 1 mm to 18 mm were measured by ELECT, and the phase change at multiple frequencies of each plate were analyzed. The shift in the phase and linearity regions of the calibration curves for each type of steel plate was observed. To analyze this shift phenomenon, the electromagnetic characteristics (permeability μ and conductivity σ) of each type of steel were measured. Compared with the permeability μ and conductivity σ of each steel plate in the applied magnetic field strength range, the product (σμ) for various steel plates decreased in the following order: SM400 > SS400 >SMA400AW > SM490A. The product of μ and σ is related to the skin depth, indicating the electromagnetic wave attenuation and eddy current phase shift in the material. Therefore, each shift in the calibration curve of each type of iron steel is explained by the changes in the parameters σ and μ.
Left-invariant optimal control problems on Lie groups: classification and problems integrable by elementary functions
Authors: Sachkov Yu. L.
Published: March 2022

Left-invariant optimal control problems on Lie groups are an important class of problems with a large symmetry group. They are theoretically interesting because they can often be investigated in full and general laws can be studied by using these model problems. In particular, problems on nilpotent Lie groups provide a fundamental nilpotent approximation to general problems. Also, left-invariant problems often arise in applications such as classical and quantum mechanics, geometry, robotics, visual perception models, and image processing.

The aim of this paper is to present a survey of the main concepts, methods, and results pertaining to left-invariant optimal control problems on Lie groups that can be integrated by elementary functions. The focus is on describing extremal trajectories and their optimality, the cut time and cut locus, and optimal synthesis. Questions concerning the classification of left-invariant sub-Riemannian problems on Lie groups of dimension three and four are also addressed.

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Supplementation of reduced protein diets with
Authors: Dao Hiep Thi , Sharma Nishchal K. , Daneshmand Ali , Kumar Alip , Bradbury Emma J. , Wu Shu-Biao , Swick Robert A.
Published: March 2022

Context Improving immune status through nutritional adjustments may be part of an effective strategy to reduce reliance on antibiotic growth promoters for controlling necrotic enteritis (NE) in broiler chickens. Aims This study examined the effect of dietary protein level and the replacement of crystalline l-arginine (Arg) with l-citrulline (Cit) in the reduced-protein diet on the performance of broilers challenged with subclinical NE. Methods Ross 308 cockerels (n = 720) were randomly allocated to six dietary treatments, with eight replicates of 15 birds per pen, during a 35-day feeding experiment. The treatments were as follows: standard protein without NE challenge (SP−); standard protein with NE challenge (SP+); reduced protein (two percentage points lower crude protein) without NE challenge (RP−); reduced protein with NE challenge (RP+); RP+ plus added Arg (103% of RP, RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. The first four treatments were considered as a 2 × 2 factorial arrangement, with factors being NE (− or +) and protein level (SP or RP). Treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results Subclinical NE challenge reduced feed intake (FI), reduced body weight gain (BWG) and increased feed to gain ratio (FCR) from Day 0 to Day 35, increased intestinal lesion scores on Day 16, and reduced relative breast yield on Day 35 (P < 0.05). Feeding RP diets increased FI (P < 0.001), increased BWG (P < 0.01) and reduced FCR (P < 0.01) during the grower phase compared with SP diets when birds were challenged with NE. Birds in the RPC+ treatment had a lower overall FCR than did those in the SP+ treatment (P < 0.001). Birds in the RPA+ treatment had similar FI, BWG and FCR to those in the RP+ treatment (P > 0.05). Conclusions Collectively, the results showed protective effects of replacing the supplemental Arg with Cit against NE in RP diets, as indicated by higher performance during and after the challenge. Implications Feeding the RP diets supplemented with Cit may be part of an effective strategy to reduce reliance on antibiotic growth promoters for controlling NE in broiler chickens.