bluuebunny/crossref_metadata_2025 huggingface dataset:
Talus
Authors: Hirsch Klemens , Manegold Sebastian
Published: February 2021

Knöcherne Verletzungen des Talus sind äußerst selten und komplex. Eine regelhafte Versorgung erfolgt daher in spezialisierten Zentren nach umfangreicher Diagnostik, Klassifikation und Planung des operativen Prozederes. Meist ist eine stabile Schraubenosteosynthese möglich, wobei stets die anatomischen Besonderheiten des Talus mit deren konsekutiven Pitfalls für die operative Therapie beachtet werden müssen. Bei deren Respektierung kann nach anatomischer Reposition und stabiler Osteosynthese eine frühfunktionelle Nachbehandlung eingeleitet und in vielen Fällen ein zufriedenstellendes und langfristig gelenkerhaltendes Outcome erzielt werden. Dieser Artikel gibt zunächst einen Überblick über die anatomischen Besonderheiten des Talus und die Klassifikation seiner Frakturen, um im Anschluss auf Grundlage der beschriebenen Besonderheiten die individuelle Planung und Durchführung des jeweiligen Zuganges und der osteosynthetischen Versorgung unter Beachtung der Pitfalls detailliert zu beschreiben. Er soll dem behandelnden Unfallchirurgen als Hilfestellung und Gedächtnisstütze bei der Versorgung dieser seltenen Verletzungen dienen, bei der nur die wenigsten über Routine verfügen.
Grundlagen der praktischen Kontaktlinsenanpassung. Teil 1
Authors: von Livonius Bettina , Emminger Ralf , Ring-Mangold Theresia
Published: February 2021

Auch wenn sich die Optionen der refraktiven Therapien in den letzten Jahren erheblich weiterentwickelt haben und viele Sehfehler mittlerweile chirurgisch oder mittels Laser korrigiert werden, haben Kontaktlinsen neben der Brille nach wie vor ihre Daseinsberechtigung. Sowohl im Lifestyle-Bereich als auch in den medizinisch indizierten Fällen stellen Kontaktlinsen als nicht operatives und einfach reversibles Verfahren nach wie vor eine sehr gute Option zur visuellen Rehabilitation dar.
Modified endoscopic ultrasound-guided double-balloon-occluded gastroenterostomy bypass (M-EPASS): a pilot study
Authors: Marino Amanda , Bessissow Ali , Miller Corey , Valenti David , Boucher Louis , Chaudhury Prosanto , Barkun Jeffrey , Forbes Nauzer , Khashab Mouen A. , Martel Myriam , Chen Yen-I
Published: February 2021

Introduction We recently developed a double-balloon device, using widely available existing technology, to facilitate endoscopic ultrasound-guided gastroenterostomy (EUS-GE). Our aim is to assess the feasibility of this modified approach to EUS-guided double-balloon-occluded gastroenterostomy bypass (M-EPASS).

Methods This was a single-center retrospective study of consecutive patients undergoing M-EPASS from January 2019 to August 2020. The double-balloon device consists of two vascular balloons that optimize the distension of a targeted small-bowel segment for EUS-guided stent insertion. The primary end point was the rate of technical success.

Results 11 patients (45 % women; mean [standard deviation (SD)] age 64.9 [8.6]) with malignant gastric outlet obstruction were included. Technical and clinical success (ability to tolerate an oral diet) were achieved in 91 % (10/11) and 80 % (8/10) of patients, respectively. There was one adverse event (9 %) due to stent migration. Two patients (18 %) required re-intervention for stent obstruction secondary to food impaction. The mean (SD) time to a low residue diet was 3.5 (2.4) days.

Conclusion M-EPASS appears to facilitate the technique of EUS-GE, potentially enhancing its safety and clinical adoption. Larger studies are needed to validate this innovative approach to gastric outlet obstruction.
Cluster Preface: Radicals – by Young Chinese Organic Chemists
Authors: Zhu Chen , Liu Xin-Yuan
Published: February 2021

(left) received his B.S. degree from Xiamen University in 2003 under the supervision of Prof. Pei-Qiang Huang, and his Ph.D. degree from the Shanghai Institute of Organic Chemistry in 2008 under the supervision of Prof. Guo-Qiang Lin. After postdoctoral research at ­Gakushuin University, Japan with Prof. Takahiko Akiyama, he moved to the University of Texas Southwestern Medical Center, working as a postdoctoral fellow with Prof. John R. Falck and Prof. Chuo Chen. He was appointed as a professor at Soochow University, China in December 2013. He is currently the Head of the Organic Chemistry Department at Soochow University. His current research interests include radical-mediated transformations, in particular radical ­rearrangements, and their applications in the construction of natural products and biologically active compounds. Xin-Yuan Liu (right) obtained his B.S. degree from Anhui Normal University (AHNU) in 2001. He continued his research studies at both the Shanghai Institute of Organic Chemistry (SIOC), CAS and AHNU under the joint supervision of Prof. Dr. Shizheng Zhu and Prof. Dr. Shaowu Wang, obtaining his master’s degree in 2004. After a one-year stint in Prof. Gang Zhao’s laboratory at SIOC, he joined Prof. Dr. Chi-Ming Che’s group at The University of Hong Kong (HKU) and earned his Ph.D. degree in 2010. He subsequently undertook postdoctoral studies in Prof. Che’s group at HKU and in Prof. Carlos F. Barbas III’s group at The Scripps Research Institute. At the end of 2012, he began his independent academic career at the Southern University of Science and Technology (SUSTech) and was promoted to a tenured Full Professor of SUSTech in 2018. His research interests are directed towards the design of novel chiral anionic ligands to solve radical-involved asymmetric reactions.
Counseling During Real Ear Measurements: The Clients' Perspective
Authors: Ryall Angela , Jenstad Lorienne M. , Pumford John , Howe Tami , Grosjean Garnet
Published: February 2021

Abstract Background When dispensing hearing aids, audiologists must follow validated fitting and verification procedures to ensure that the hearing aids are properly fitted to the client's hearing. Real ear measurements (REMs) are best practice for verifying
hearing aids. Prior literature regarding REMs has mainly focused on the clinicians' perspective. Purpose This study investigated informational counseling throughout REMs by gathering perspectives of first-time hearing aid users regarding the content and format of counseling.
Research Design The study used an interpretive description approach with focus groups. Study Sample There were 16 adult participants (4 males, 12 females) who were first-time hearing aid users and who all had memory of REMs occurring during their own hearing aid
verification. Intervention We investigated the addition of informational counseling during REM verification. Data Collection and Analysis Four focus groups were conducted to elicit feedback on a demonstration of informational counseling during REM hearing aid
verification. The data from the focus groups were transcribed verbatim and analyzed using qualitative content analysis. Results Analysis revealed positive aspects, negative aspects, and suggested changes in relation to the verbal and visual information presented during the
REM verification demonstration. These data fell into two broad categories: the interaction and transaction of informational counseling. Conclusion Most clients were interested in learning more about REMs if the information was accessible. Results provide recommendations for
clinical audiologists and REM system manufacturers to make the information presented during informational counseling more client-friendly and individualized for client-centered care. To continue exploring this new inquiry, further experimental research is required to determine if there is
any added value of incorporating informational counseling during REMs.
Acceptable Noise Levels Determined by Traditional and Self-Assessed Methods
Authors: Barnett Megan , Jones Alisha L. , Westbrook Erin
Published: February 2021

Abstract Background Many apps have been developed for users to screen their hearing in their own home. The purpose of this study was to investigate the validity and efficiency of a self-assessed acceptable noise level (ANL) in comparison to the traditional ANL
measurements. Research Design A within-subject repeated measures research design was utilized. Data Collection and Analysis Sixty-two adults with normal hearing were recruited from Auburn University and the surrounding community. ANLs were measured utilizing
the traditional measurement as well as the self-assessed ANL via the Unitron uHear app. Results Within-subject repeated measures of variance revealed no significant differences between traditional ANL measurements and self-assessed ANL measurements. Significant differences
were found for time required for testing in each condition, revealing self-assessed testing to be significantly faster. Conclusion The self-assessed ANL measurement via the Unitron uHear app is a valid and efficient measurement of ANL in adults with normal hearing.
Three Cases of Recovery from Sensorineural Hearing Loss in the First Year of Life: Implications for Monitoring and Management
Authors: Plyler Erin , Harkrider Ashley W. , Little John P.
Published: February 2021

Abstract Background Three infants with different risk factors, behavioral and physiologic audiometric histories, and diagnoses were fit with amplification between 3 and 8 months of age. Two of the three met criteria for cochlear implantation. Purpose This
article aims to heighten awareness of the rare possibility of recovery from sensorineural hearing loss in infants with varying histories and emphasize the importance of a full diagnostic test battery in all infants diagnosed with sensorineural hearing loss every 3 months until objective and
subjective thresholds are stable to ensure appropriate intervention. Research Design Case reports. Results All three infants demonstrated improvement or full recovery of hearing and cochlear function by approximately 12 months old. Their change in hearing was
discovered due to frequent follow-up and/or caregiver report. One of these infants was tentatively scheduled to have cochlear implant surgery 2 months later. Conclusion Appropriate early intervention for infants with hearing loss is critical to ensure maximum accessibility
to speech and language cues. The Federal Drug Administration approves cochlear implantation in infants as young as 12 months. When providing audiometric management of infants with sensorineural hearing loss, it is imperative to conduct a full diagnostic test battery every 3 months (including
tympanometric, acoustic reflex, and otoacoustic emission measurement) until objective and subjective thresholds are stable. There was no apparent pattern of factors to predict that the infants highlighted in these cases would recover. Discussion among pediatric audiologists and otologists
and comparison of data from clinics across the U.S. is needed to identify predictive patterns and determine appropriate, consistent monitoring of infants with sensorineural hearing loss.
The Effect of Background Noise on Immediate Free Recall of Words in Younger and Older Listeners with Hearing Loss
Authors: Hwang Jung-sun , Jung Yukyeong , Lee Jae Hee
Published: February 2021

Abstract Background Auditory working memory is a crucial factor for complex cognitive tasks such as speech-in-noise understanding because speech communication in noise engages multiple auditory and cognitive capacities to encode, store, and retrieve information.
An immediate free recall task of words has been used frequently as a measure of auditory working memory capacity. Purpose The present study investigated performance on the immediate free recall of words in quiet and noisy conditions for hearing-impaired listeners. Research
Design Fifty hearing-impaired listeners (30 younger and 20 older) participated in this study. Lists of 10 phonetically and lexically balanced words were presented with a fixed presentation rate in quiet and noise conditions. Target words were presented at an individually determined
most comfortable level (MCL). Participants were required to recall as many of the words in an arbitrary order immediately after the end of the list. Serial position curves were determined from the accuracy of free recall as a function of the word position in the sequence. Data Collection
and Analysis Three-way analyses of variance with repeated measures were conducted on the percent-correct word recall scores, with two independent within-group factors (serial position and listening condition) and a between-group factor (younger, older). Results A traditional
serial position curve was found in hearing-impaired listeners, yet the serial position effects depended on the listening condition. In quiet, the listeners with hearing loss were likely to recall more words from the initial and final positions compared with the middle-position words. In multi-talker
babble noise, more difficulties were observed when recalling the words in the initial position compared with the words in the final position. Conclusion Without a noise, a traditional U-shaped serial position curve consisting of primacy and recency effects was observed
from hearing-impaired listeners, in accord with previous findings from normal-hearing listeners. The adverse impact of background noise was more pronounced in the primacy effect than in the recency effect.
Korean Clear Speech Improves Speech Intelligibility for Individuals with Normal Hearing and Individuals with Hearing Loss
Authors: Shin Su Yeon , Oh Hongyeop , Jin In-Ki
Published: February 2021

Abstract Background Clear speech is an effective communication strategy to improve speech intelligibility. While clear speech in several languages has been shown to significantly benefit intelligibility among listeners with differential hearing sensitivities
and across environments of different noise levels, whether these results apply to Korean clear speech is unclear on account of the language's unique acoustic and linguistic characteristics. Purpose This study aimed to measure the intelligibility benefits of Korean clear speech
relative to those of conversational speech among listeners with normal hearing and hearing loss. Research Design We used a mixed-model design that included both within-subject (effects of speaking style and listening condition) and between-subject (hearing status) elements.
Data Collection and Analysis We compared the rationalized arcsine unit scores, which were transformed from the number of keywords recognized and repeated, between clear and conversational speech in groups with different hearing sensitivities across five listening conditions (quiet
and 10, 5, 0, and ‐5 dB signal-to-noise ratio) using a mixed model analysis. Results The intelligibility scores of Korean clear speech were significantly higher than those of conversational speech under most listening conditions in all groups; the former yielded
increases of 6 to 32 rationalized arcsine units in intelligibility. Conclusion The present study provides information on the actual benefits of Korean clear speech for listeners with varying hearing sensitivities. Audiologists or hearing professionals may use this information
to establish communication strategies for Korean patients with hearing loss.
Extracerebral Pterional Metastasis from Malignant Meningioma: A Case Report
Authors: Pereira Edmundo Luís Rodrigues , Cabral Diego Arthur Castro , Campos Fernanda Myllena Sousa
Published: February 2021

Anaplastic or malignant meningiomas that are classified as World Health Organization (WHO) grade III account for less than 1% of all meningiomas diagnosed. Despite the aggressive course, distant metastases are a rarity, occurring in only 0.1% to 0.2% of cases. We report the case of a 56-year-old woman who presented with parasagittal benign meningioma that underwent malignant transformation along with metastasis into the right orbitosphenoid region. The clinical, radiological, and histopathological aspects are highlighted, with an emphasis on the natural history of meningiomas.
Enhancing Adherence to Voice Therapy via Social Cognitive Strategies
Authors: van Leer Eva
Published: February 2021

Treatment adherence is a challenge in behavioral voice therapy. Patients commonly encounter difficulties with practicing and implementing target voice techniques outside of the clinic. Several mobile support strategies have been shown to improve adherence. These strategies are driven by social cognitive theory, which provides a theoretical but practical framework for understanding adherence behavior and solving adherence problems. Key features of the theory include (1) its model of triadic asymmetrical reciprocal causation, (2) the concept of human agency, and (3) the constructs of self-efficacy and goal commitment. The purpose of this article is to (1) explain voice therapy adherence within the framework of social cognitive theory, (2) illustrate three broad categories of adherence problems, and (3) provide examples of strategies to address each. With this exemplified knowledge, the clinician can diagnose factors that underlie patients' adherence problems and develop individualized solutions. Given the significant role adherence plays in behavioral interventions, this information holds substantial clinical relevance.
Histomorphology of the Subregions of the Scapholunate Interosseous Ligament and Its Enthesis
Authors: Liew Mei Yen , Mortimer Jeremy W. , Paxton Jennifer Z. , Tham Stephen , Rust Philippa A.
Published: February 2021

Background The scapholunate interosseous ligament (SLIL) has three subregions: dorsal, proximal, and volar. The SLIL enthesis has not previously been studied despite its important mechanical function in wrist joint biomechanics.

Questions/Purposes This study aims to compare the histomorphological differences between the SLIL subregions, including at their entheses. Three questions are explored: Do the gross dimensions differ between SLIL subregions? Does the enthesis qualitatively, and its calcified fibrocartilage (CF) quantitatively, differ between (a) SLIL subregions and (b) scaphoid and lunate attachments?

Methods Twelve fresh-frozen human cadaveric wrists were dissected and the gross dimensions of the SLIL subregions measured. Subregions were histologically processed for morphological and compositional analyses, including quantification of enthesis CF area.

Results The dorsal subregion was the thickest. The dorsal and volar subregions had fibrocartilaginous entheses, while the proximal subregion was attached to articular cartilage. The dorsal subregion had significantly more CF than the volar subregion. There was no significant difference in the enthesis CF between scaphoid and lunate attachments in the three subregions.

Conclusions There are significant morphological differences between the SLIL subregions. The dorsal subregion has the largest amount of CF, which is consistent with the greater biomechanical force subjected to this subregion. The similar histomorphology of the ligament at the scaphoid and lunate entheses suggests that similar biomechanical forces are applied to both attachments.

Clinical Relevance The histomorphological results confirm that the dorsal subregion is the strongest of the three subregions. The results from the entheseal region may have important implications in the study of graft incorporation during SLIL reconstruction.
A Systematic Review and Meta-Analysis of Microvascular Stacked and Conjoined-Flap Breast Reconstruction
Authors: Salibian Ara A. , Nolan Ian T. , Bekisz Jonathan M. , Frey Jordan D. , Karp Nolan S. , Choi Mihye , Levine Jamie P. , Thanik Vishal D.
Published: February 2021

Background Stacked and conjoined (SC) flaps are a useful means of increasing flap volume in autologous breast reconstruction. The majority of studies, however, have been limited to smaller, single-center series.

Methods A systematic literature review was performed to identify outcomes-based studies on microvascular SC-flap breast reconstruction. Pooled rates of flap and operative characteristics were analyzed. Meta-analytic effect size estimates were calculated for reconstructive complication rates and outcomes of studies comparing SC flaps to non-SC flaps. Meta-regression analysis identified risk factors for flap complications.

Results Twenty-six studies were included for analysis (21 case series, five retrospective cohort studies) for a total of 869 patients, 1,003 breasts, and 2006 flaps. The majority of flaps were harvested from the bilateral abdomen (78%, 782 breasts) followed by combined abdomen-thigh stacked flaps (22.2%, 128 breasts). About 51.1% of flaps were anastomosed to anterograde/retrograde internal mammary vessels (230 breasts) and 41.8% used internal mammary/intraflap anastomoses (188 breasts). Meta-analysis revealed a rate of any flap complication of 2.3% (95% confidence interval: 1.4–3.3%), Q-statistic value p = 0.012 (I
2 = 43.3%). SC flaps had a decreased risk of fat necrosis compared with non-SC flaps (odds ratio = 0.126, p < 0.0001, I
2 = 0.00%), though rates of any flap and donor-site complication were similar. Age, body mass index, flap weight, and flap donor site and recipient vessels were not associated with increased risk of any flap complication.

Conclusion A global appraisal of the current evidence demonstrated the safety of SC-flap breast reconstruction with low complication rates, regardless of donor site, and lower rates of fat necrosis compared with non-SC flaps.
Arctic narratives: brewing a brand with neolocalism
Authors: Ikäheimo Janne P.
Published: February 2021

Neolocalism has been identified as an important component in the current boom in microbreweries. When constructed actively and consciously, it can also be deployed in marketing as a method of brand-related storytelling. This argument is strengthened here through a case study focusing on Tornio Brewery, a microbrewery located near the southern edge of the Arctic in northern Finland. The qualitative research method used here involves the identification of stories related to neolocalism from the brand narrative composed of media releases, advertisements and other promotional material, in addition to beer names and labels. The themes emerging from this material—history and heritage, Lapland and the Arctic as geographic locations, the use of local ingredients and community involvement, as well as the culture and heritage of northern Finland—are then explored. Neolocalism is shown to provide a rich vein of storytelling that can be used effectively for marketing purposes as a holistic concept. While craft brewers have already explored neolocalism in their marketing efforts, the use of professional assistance in creating all-encompassing and meditated storylines is strongly recommended.
Associations of physical activity in rural life with happiness and ikigai: a cross-sectional study
Authors: Kabasawa Keiko , Tanaka Junta , Ito Yumi , Yoshida Kinya , Kitamura Kaori , Tsugane Shoichiro , Nakamura Kazutoshi , Narita Ichiei
Published: February 2021

Physical activity is associated with subjective well-being. In rural communities, however, physical activity may be affected by environmental factors (e.g., nature and socioecological factors). We examined the association of two physical activities in rural life (farming activity and snow removal) with subjective well-being in terms of happiness andikigai(a Japanese word meaning purpose in life). In this cross-sectional study, we analysed data collected from community-dwelling adults aged ≥ 40 years in the 2012–2014 survey of the Uonuma cohort study, Niigata, Japan. Happiness (n = 31,848) andikigai(n = 31,785) were evaluated with respect to farming activity from May through November and snow removal from December through April by using an ordinal logistic regression model with adjustments for potential confounders. The analyses were conducted in 2019. Among the participants who reported some farming or snow-removal time, median farming and snow-removal time (minutes per day) was 90.0 and 64.3 for men and 85.7 and 51.4 for women, respectively. Ordinal logistic regression analysis showed that longer time farming was associated with greater happiness andikigaiin men (adjusted odds ratio for first vs. fourth quartile: happiness = 1.17, 95% confidence interval [CI] = 1.01, 1.35;ikigai = 1.29, 95% CI = 1.10, 1.50), and also in women (adjusted odds ratio for first vs. fourth quartile: happiness = 1.17, 95% CI = 1.001, 1.36;ikigai = 1.42, 95% CI = 1.20, 1.67). More snow-removal time was inversely associated with happiness and withikigaiin women only (adjusted odds ratio for first vs. fourth quartile: happiness = 0.75, 95% CI = 0.67, 0.85;ikigai = 0.78, 95% CI = 0.69, 0.88). Our findings showed that physical activity in rural life was associated with happiness and withikigai, and gender differences were observed in their associations with more snow-removal time. These results may be useful in helping to identify people in rural communities who are vulnerable in terms of psychological well-being.
Singular geometrical optics for differential operators on surfaces
Authors: Valero-Valdés Carlos
Published: February 2021

Inspired by the optical phenomenon of conical refraction, discovered by Hamilton in 1832, we study the existence of singular optical phenomena associated with linear differential operators acting on vector fields on a surface. We do this by studying the singularities of the Fresnel hyper-surface associated with the differential operator and show that the existence of these singularities can be accounted for from purely topological considerations. We associate a topological number (an integer) to the space of singularities of the Fresnel hyper-surface, which can be used to “count” the number points at which singular optical phenomena occur.
A new MPPT method based on a modified Fibonacci search algorithm for wind energy conversion systems
Authors: Yazıcı İrfan , Yaylacı Ersagun Kürşat , Cevher Barış , Yalçın Faruk , Yüzkollar Can
Published: February 2021

In this paper, a new maximum power point tracking (MPPT) method based on the Fibonacci search algorithm (FSA) is proposed for the wind energy conversion system (WECS). The conventional FSA is modified according to the requirements of the WECS to improve its performance as an MPPT algorithm. The performance of the proposed method is investigated for different wind-speed profiles such as step-type and stochastically varied wind speed. Also, the modified FSA based MPPT algorithm is compared with the conventional perturb and observe (CPO) and variable-step PO (VSPO) algorithms. The simulation results approve the superior performance of the proposed method over the CPO and VSPO in terms of maximum power extracted from the system. The real-time performance of the proposed method is also investigated for varying wind conditions in the form of step-up and step-down.
The Devil’s Triangle of Kohn–Sham density functional theory and excited states
Authors: Mendes Rodrigo A. , Haiduke Roberto L. A. , Bartlett Rodney J.
Published: February 2021

Exchange–correlation (XC) functionals from Density Functional Theory (DFT) developed under the rigorous arguments of Correlated Orbital Theory (COT) address the Devil’s Triangle of prominent errors in Kohn–Sham (KS) DFT. At the foundation of this triangle lie the incorrect one-particle spectrum, the lack of integer discontinuity, and the self-interaction error. At the top level, these failures manifest themselves in incorrect charge transfer and Rydberg excitation energies, along with poor activation barriers. Accordingly, the Quantum Theory Project (QTP) XC functionals have been created to address several of the long-term issues encountered in KS theory and its Time Dependent DFT (TDDFT) variant for electronic excitations. Recognizing that COT starts with a correct one-particle spectrum, a condition imposed on the QTP functionals by means of minimum parameterization, the question that arises is how does this affect the electronically excited states? Among up to 28 XC functionals considered, the QTP family provides one of the smallest mean absolute deviations for charge-transfer excitations while also showing excellent results for Rydberg states. However, there is some room for improvement in the case of excitation energies to valence states, which are systematically underestimated by all functionals investigated. An alternative path for better treatment of excitation energies, mainly for valence states, is offered by using orbital energies from QTP functionals, especially by CAM-QTP-02 and LC-QTP. In this case, the deviations from the reference data can be reduced approximately by half.
Turbulent transport of fast ions in tokamak plasmas in the presence of resonant magnetic perturbations
Authors: Palade D. I.
Published: February 2021

The effects of resonant magnetic perturbations on the turbulent transport of fast ions in tokamak devices are investigated using a theoretical transport model of test-particle type. The direct numerical simulation method is used to compute, via the transport model, the diffusion coefficients. The numerical results are in good agreement with other, analytically derived, estimations. It is found that finite Larmor radius effects algebraically decrease the transport, while the amplitude of magnetic perturbations has an opposite effect. In the presence of stochastic dynamics, the asymmetric toroidal magnetic field induces a small, radial, outward pinch. A synergistic mechanism of non-linear coupling between the effects of turbulence and those of magnetic perturbations enhances the radial diffusion. General scaling laws are proposed for the transport coefficients.
Soft-mode spectroscopy of ferroelectrics and multiferroics: A review
Authors: Kamba S.
Published: February 2021

This article summarizes the results of the investigations of the dynamics of ferroelectric (FE) phase transitions (PTs) obtained in Prague during the last 25 years. After a short introduction, explaining differences between displacive and order-disorder types of FE PTs, the results of the broadband dielectric, THz, and mainly IR spectroscopic investigations of hydrogen-bonded FEs, BaTiO3, relaxor FEs, strained incipient FEs, and various multiferroics are reviewed. The high sensitivity of the IR spectroscopy to polar phonons was demonstrated in ultrathin films, which allowed us to reveal strain-induced FE PTs. Electrically active magnons (i.e., electromagnons) can be observed in the IR and Raman spectra of multiferroics. Their frequencies soften on heating toward temperatures of magnetic PTs similarly as phonons in displacive FEs. As expected, the electromagnons can be dependent on the external magnetic field. This behavior has been demonstrated in BiFeO3, SrMn7O12, and multiferroics with Y- and Z-type hexaferrite crystal structures.
Improved control of atomic layering in perovskite-related homologous series
Authors: Barone Matthew R. , Dawley Natalie M. , Nair Hari P. , Goodge Berit H. , Holtz Megan E. , Soukiassian Arsen , Fleck Erin E. , Lee Kiyoung , Jia Yunfa , Heeg Tassilo , Gatt Refael , Nie Yuefeng , Muller David A. , Kourkoutis Lena F. , Schlom Darrell G.
Published: February 2021

Homologous series are layered phases that can have a range of stoichiometries depending on an index n. Examples of perovskite-related homologous series include (ABO3)nAO Ruddlesden–Popper phases and (Bi2O2) (An−1BnO3n+1) Aurivillius phases. It is challenging to precisely control n because other members of the homologous series have similar stoichiometry and a phase with the desired n is degenerate in energy with syntactic intergrowths among similar n values; this challenge is amplified as n increases. To improve the ability to synthesize a targeted phase with precise control of the atomic layering, we apply the x-ray diffraction (XRD) approach developed for superlattices of III–V semiconductors to measure minute deviations from the ideal structure so that they can be quantitatively eradicated in subsequent films. We demonstrate the precision of this approach by improving the growth of known Ruddlesden–Popper phases and ultimately, by synthesizing an unprecedented n = 20 Ruddlesden–Popper phase, (ATiO3)20AO where the A-site occupancy is Ba0.6Sr0.4. We demonstrate the generality of this method by applying it to Aurivillius phases and the Bi2Sr2Can–1CunO2n+4 series of high-temperature superconducting phases.
An integrated microfluidic bubble pocket for long-term perfused three-dimensional intestine-on-a-chip model
Authors: Lee Kang Kug (Paul) , Matsu-ura Toru , Rosselot Andrew E. , Broda Taylor R. , Wells James M. , Hong Christian I.
Published: February 2021

Perfused three-dimensional (3D) cultures enable long-term in situ growth and monitoring of 3D organoids making them well-suited for investigating organoid development, growth, and function. One of the limitations of this long-term on-chip perfused 3D culture is unintended and disruptive air bubbles. To overcome this obstacle, we invented an imaging platform that integrates an innovative microfluidic bubble pocket for long-term perfused 3D culture of gastrointestinal (GI) organoids. We successfully applied 3D printing technology to create polymer molds that cast polydimethylsiloxane (PDMS) culture chambers in addition to bubble pockets. Our developed platform traps unintended, or induced, air bubbles in an integrated PDMS pocket chamber, where the bubbles diffuse out across the gas permeable PDMS or an outlet tube. We demonstrated that our robust platform integrated with the novel bubble pocket effectively circumvents the development of bubbles into human and mouse GI organoid cultures during long-term perfused time-course imaging. Our platform with the innovative integrated bubble pocket is ideally suited for studies requiring long-term perfusion monitoring of organ growth and morphogenesis as well as function.
Research on maximum power point tracking control of acoustic energy harvest system
Authors: Gu Cong , Chen Yuansheng , Jiang Kun
Published: February 2021

As a kind of renewable energy, acoustic energy can be converted into electrical energy to supply energy for micro-electronic devices, which is a meaningful research topic. In order to keep working at the maximum power point all the time, an acoustic energy harvest system based on the maximum power point tracking (MPPT) control method is proposed. The system is composed of a Helmholtz resonator, a piezoelectric transducer, and an interface circuit, and the interface circuit is composed of a rectifier circuit and a buck-boost circuit. When the acoustic wave enters the cavity, the acousto-electric conversion is carried out through the piezoelectric transducer, and then the DC power is output through the interface circuit. Finally, through the MPPT control program, the system always works at the maximum power point. The theoretical and simulation analysis of the interface circuit is carried out, and the performance of the system is studied and verified by experiments. When the load is constant and the SPL (Sound Pressure Level) increases, the optimal duty cycle fluctuates between 0.1 and 0.3, and the voltage and power of the load increase with the increase of the SPL. When the SPL is 110 dB and the duty cycle is 0.15, the maximum power of the load is 115.2 µW. When the SPL is 110 dB, the optimal duty cycle fluctuates between 0.1 and 0.2. When the load resistance is 30 kΩ, 50 kΩ, 70 kΩ, 90 kΩ, and 110 kΩ, the maximum power of the load is 110.45 µW, 115.2 µW, 104.14 µW, 106.78 µW, and 105.1 µW, respectively.
Effects of interaction strength of associating groups on linear and star polymer dynamics
Authors: Senanayake Manjula , Perahia Dvora , Grest Gary S.
Published: February 2021

A small number of associating groups incorporated onto a polymer backbone have dramatic effects on the mobility and viscoelastic response of the macromolecules in melts. These associating groups assemble, driving the formation of clusters, whose lifetime affects the properties of the polymers. Here, we probe the effects of the interaction strength on the structure and dynamics of two topologies, linear and star polymer melts, and further investigate blends of associative and non-associating polymers using molecular dynamics simulations. Polymer chains of approximately one entanglement length are described by a bead–spring model, and the associating groups are incorporated in the form of interacting beads with an interaction strength between them that is varied from 1 to 20 kBT. We find that, for all melts and blends, interaction of a few kBT between the associating groups drives cluster formation, where the size of the clusters increases with increasing interaction strength. These clusters act as physical crosslinkers, which slow the chain mobility. Blends of chains with and without associating groups macroscopically phase separate for interaction strength between the associating groups of a few kBT and above. For weakly interacting associating groups, the static structure function S(q) is well fit by functional form predicted by the random phase approximation where a clear deviation occurs as phase segregation takes place, providing a quantitative assessment of phase segregation.
Dipole-bound and valence excited states of AuF anions via resonant photoelectron spectroscopy
Authors: Lu Yuzhu , Tang Rulin , Fu Xiaoxi , Liu Hongtao , Ning Chuangang
Published: February 2021

Gold fluoride is a very unique species. In this work, we reported the resonant photodetachment spectra of cryogenically cooled AuF− via the slow-electron velocity-map imaging method. We determined the electron affinity of AuF to be 17 976(8) cm−1 or 2.2287(10) eV. We observed a dipole-bound state with a binding energy of 24(8) cm−1, a valence excited state with a binding energy of 1222(11) cm−1, and a resonant state with an energy of 814(12) cm−1 above the photodetachment threshold. An unusual vibrational transition with Δn = −3 was observed in the autodetachment from the dipole-bound state. Moreover, two excited states of neutral AuF were recognized for the first time, located at 13 720(78) cm−1 and 16 188(44) cm−1 above the AuF ground state.
A comparison of Raman and pyrometry dynamic temperature measurements of shocked cyclohexane
Authors: Hartsfield T. M. , Lang J. M. , Goodwin P. M. , Veeser L. R.
Published: February 2021

Optical pyrometry is a well-developed, broadly applicable method to determine temperature in dynamic compression experiments. However, it measures radiation from only the skin depth of the radiant material, is highly susceptible to spurious backgrounds, and requires an often-unmeasurable free parameter—the sample dynamic emissivity. Raman spectroscopy offers a method to determine temperature directly from fundamental theory, but it is practically limited in applications to a small subset of shock experiments. In this work, we describe an experiment allowing simultaneous application of Raman and pyrometric temperature techniques to benchmark a specific instance of pyrometry. We attempted both measurements on multiple experiments and compare the successful temperature results between the separate but highly repeatable shots. We find that dynamic shock temperatures inferred from Raman spectroscopy and pyrometry generally agree within the uncertainties of each measurement, although those uncertainties are larger than typical for a specially designed pyrometry experiment on a shocked metal sample.
A foldable compact actuator based on an oxetane liquid crystal network
Authors: Hoekstra Davey C. , Visser Patricia P. M. , Houben Simon J. A. , Lub Johan , Debije Michael G. , Schenning Albert P. H. J.
Published: February 2021

The fabrication of a foldable, compact liquid crystal actuator based on oxetane reactive monomers is reported. The free-standing liquid crystal network films are optically clear, flexible, and have easily tunable anisotropic thermal and mechanical properties. The oxetane liquid crystal networks demonstrate excellent one-way shape memory properties, with good temporary shape fixation and complete shape recovery. In addition, the flexible polyether backbone of the oxetane liquid crystal networks results in large two-way bending actuation, with the actuators showing rotation inversion and making multiple rotations. Both actuation mechanisms could be combined to form actuators that can be temporarily folded before fully recovering to their original shape prior to use. As a result, the oxetane liquid crystal networks have great potential as foldable, compact actuators.
Efficient implementation of the single-reference algebraic diagrammatic construction theory for charged excitations: Applications to the TEMPO radical and DNA base pairs
Authors: Banerjee Samragni , Sokolov Alexander Yu.
Published: February 2021

We present an efficient implementation of the second- and third-order single-reference algebraic diagrammatic construction (ADC) theory for electron attachment and ionization energies and spectra [EA/IP-ADC(n), n = 2, 3]. Our new EA/IP-ADC program features spin adaptation for closed-shell systems, density fitting for efficient handling of the two-electron integral tensors, and vectorized and parallel implementation of tensor contractions. We demonstrate capabilities of our efficient implementation by applying the EA/IP-ADC(n) (n = 2, 3) methods to compute the photoelectron spectrum of the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) radical, as well as the vertical and adiabatic electron affinities of TEMPO and two DNA base pairs (guanine–cytosine and adenine–thymine). The spectra and electron affinities computed using large diffuse basis sets with up to 1028 molecular orbitals are found to be in good agreement with the best available results from the experiment and theoretical simulations.
Design of a dispersion interferometer on a field-reversed configuration device
Authors: Yang Chengyu , Gao Li , Chen Zhipeng , Ding Yonghua , Rao Bo , Yang Zhoujun , Zhou Yinan
Published: February 2021

Dispersion interferometry (DI) is a promising method for density measurement. Compared with the traditional interferometer, the DI is immune to mechanical vibration and can avoid the fringe jump error. In addition, a simple optical configuration is also one of the advantages of the DI. The electron density of the Huazhong University of Science and Technology field-reversed configuration (HFRC) device can reach 1020 m−3 with a pulse length of 50 µs. In this case, the DI based on the CO2 laser on the HFRC device adopts the heterodyne technique based on the acousto-optic modulator, which can increase the temporal resolution to 40 MHz. It can realize density fluctuation measurements in the MHz range. The test of each optical element, especially the nonlinear crystal, has been completed. The AgGaSe2 crystal can produce a second harmonic wave of about 52.5 µW when the incident CO2 power is 10 W. Based on these designs and tests, a DI system can be expected on the HFRC device.
Visualization of large-scale charged domain Walls in hexagonal manganites
Authors: Fan Fei , Gao Ziyan , Ponet Louis , Wang Jing , Huang Houbing , Artyukhin Sergey , Hong Jiawang , Cheong Sang-Wook , Wang Xueyun
Published: February 2021

A ferroelectric charged domain wall (CDW) carries bound charges, originating from the variation of the normal components of polarization across the domain boundary, leading to a possible two-dimensional conductive interface in insulating materials. The ferroelectric CDW can be precisely created, erased, and manipulated, therefore offering an intriguing pathway toward the design of nano-devices. However, due to rather large energy costs, the size of the CDW is usually on the nanoscale. Here, taking flux-grown ferroelectric hexagonal manganites (h-RMnO3) as an example, we creatively adopted an accessible inclined polishing process to reveal the domain evolution of stripe, loop, and vortex domain patterns by depth profiling. Interestingly, we observed an unexpected large-scale straight CDW in as-grown LuMnO3 with length up to a millimeter size, which may result from the “polar catastrophe” during the flux growth. The large-scale CDW has a residual influence on the formation of the loop domain when the crystal anneals below the ferroelectric transition temperature, but completely disappears as the topological vortices emerge. The observed large-scale CDWs make h-RMnO3 a potential candidate for advanced electronic devices, leading to a panoply of desired properties.
An intravascular helical magnetic millirobot with a gripper mechanism performing object delivery and collecting motions actuated by precession rotating magnetic fields
Authors: Lee H. J. , Jeon S. M.
Published: February 2021

This research proposes a novel intravascular helical magnetic millirobot (IHMM) that can conduct various functional motions such as helical navigating, unclogging, object delivery, and object collecting motions, simply actuated by a precession rotating magnetic field (PRMF). The proposed IHMM is composed of a helical body with a tapered drilling tip attached to the front head. Since it is composed of two identical halves of a cone hinged to two separate pin joints, the drilling tip can also act as a magnetically actuated gripper to deliver objects to a target area or collect debris after unclogging motions. This research established a simplified equation to maneuver the IHMM’s different mechanical motions in a straightforward manner. Then, it conducted various experiments demonstrating various functional motions of the IHMM to show the validity of the proposed mechanism.
The linguistic conceptualization in folk aesthetics
Authors: Gladkova Anna , Romero-Trillo Jesús
Published: February 2021

This Special Issue is dedicated to the analysis of the linguistic conceptualization of “beautiful” and “ugly” as
the key concepts that are basic to aesthetic appreciation across languages and cultures within the framework of folk aesthetics.
For this purpose, we present a collection of original research articles analyzing concepts related to folk aesthetics in seven
languages: English, Spanish, Japanese, Russian, Danish, Persian, and Mandarin Chinese. All studies in this Special Issue focus on
words and concepts as representations of culture-specific ways of aesthetic appreciation. Most of the studies are corpus-based,
therefore they draw their conclusions on significant linguistic data.
“What is beauty?”
Authors: Gladkova Anna
Published: February 2021

The paper studies the semantics of four Russian key terms of aesthetic evaluation:krasivyj‘beautiful’,prekrasnyj‘beautiful/fine’,nekrasivyj’ugly/plain’ andbezobraznyj‘ugly/frightful’. It demonstrates different patterns of polysemy of the words and the nuances of meaning. Following the framework of folk aesthetics and cultural semantics, the meanings of the terms in question are represented using the Natural Semantic Metalanguage (NSM) and are shown to relate to Russian cultural themes. The analysis demonstrates cultural significance of aesthetic value in Russian and its intrinsic link with ethics, morality and politeness.
The good, the bad… and the ugly?
Authors: Romero-Trillo Jesús
Published: February 2021

The present article describes the conceptualization of aesthetics in Spanish through the analysis of the two prototypical terms that describe positive and negative sensory appreciation, i.e., “bonito” (beautiful) and “feo” (ugly). Following a mixed-approach methodology combining Natural Semantic Metalanguage and Corpus Pragmatics, the article compares the use of these adjectives in spoken and written language, analyzes their realization in the corpora under analysis, provides the explications that support their polysemy, and describes their distribution in different contexts. The final part of the paper is devoted to the comparison of the use of these adjectives with their counterparts in English, as evidenced by another paper in this special issue.