bluuebunny/crossref_metadata_2025 huggingface dataset:
Pneumothorax
Authors: Eggeling Stephan
Published: February 2021

Als Pneumothorax bezeichnet man das Vorhandensein von freier Luft zwischen der Pleura visceralis und der Pleura parietalis. Es kommt zu einer „Ablösung“ der Lunge von der Brustwand, welche in Abhängigkeit von dem Ausmaß des Pneumothorax zu einer geringen oder auch klinisch bedrohlichen Einschränkung der Lungenfunktion führt. Unspezifische Zeichen wie thorakaler Schmerz oder Hustenreiz sind häufig und korrelieren nicht mit der Ausdehnung des Pneumothorax. Nahezu ausnahmslos besteht die Ursache dieser Luftansammlung in einer Undichtigkeit der Lungenoberfläche, welche dann zu dem Ausweichen der Luft in den Pleuraraum führt. Je nach Ursache der „Lungenundichtigkeit“ unterscheidet man einen primären (idiopathischen) Spontanpneumothorax (PSP), bei zugrundliegender bekannter Lungenerkrankung einen sekundären Spontanpneumothorax (SSP), im Zusammenhang einer Lungenverletzung durch medizinische Maßnahmen einen iatrogenen Pneumothorax sowie bei einem unfallbedingten Lungenriss
einen traumatischen Pneumothorax. Die relevanten Therapieziele sind die Behebung der akuten Symptomatik, die verlässliche Erreichung einer Wiederausdehnung der Lunge sowie nach entsprechender Aufklärung über die Wahrscheinlichkeit und klinische Bedeutung eines Pneumothoraxrezidives je nach Patientenwunsch die Vermeidung eines Rezidives durch operative Maßnahmen. Die Therapiemöglichkeiten reichen hier von einem lediglich befundkontrollierenden abwartenden ambulanten Prozedere bis hin zu einer primären videoassistierten thorakoskopischen operativen Therapie mit Detektion und Resektion der oberflächlichen Lungenläsion sowie einer die Pleurahöhle obliterierenden Maßnahme zur Rezidivprophylaxe. Bezüglich einer „Nachsorge“ oder gar Verhaltensempfehlungen nach stattgehabtem Pneumothorax gibt es keine Empfehlungen, die die Rezidivgefahr verringern.
Das EUROSPINE Ausbildungskonzept
Authors: Blattert T. R. , Côté P. , Krieg S. M. , Meyer B. , Noël J.-L. , Nordin M. , Rothenfluh D.
Published: February 2021

Das Aus- und Fortbildungskonzept von EUROSPINE, der Spine Society of Europe, basiert auf 3 Säulen: Das EUROSPINE Basic Diploma, das EUROSPINE Advanced Diploma und das EUROSPINE Diploma in Interprofessional Spine Care (EDISC). Während die ersten beiden einen operativen Schwerpunkt haben, ist EDISC konservativ und interprofessional ausgelegt.

Sowohl das Basic als auch das Advanced Diploma werden seit 2019 als hybrides Lehrkonzept angeboten. Das bedeutet, dass nur interaktive Falldiskussionen vor Ort stattfinden, während die übrigen Ausbildungsinhalte virtuell gelehrt werden. Ab 2021 wird schließlich das gesamte Ausbildungsspektrum auch vollständig virtuell zur Verfügung stehen.

Im Rahmen eines 2016 ins Leben gerufenen internationalen europäischen Äquivalenzprogramms existiert mit derzeit 6 europäischen nationalen Wirbelsäulenfachgesellschaften, darunter auch mit der DWG, eine gegenseitige Anerkennung der Curricula. Somit besteht Äquivalenz zwischen dem DWG-Basiszertifikat und dem EUROSPINE Basic Diploma sowie zwischen dem DWG-Masterzertifikat und dem EUROSPINE Advanced Diploma.

Die Gewährleistung einer einheitlichen europäischen Ausbildungsstruktur soll schließlich eine Anerkennung der Spezialisierung auf europäischer und nationaler Ebene vorantreiben, wie es für Deutschland konkret die Einführung der Zusatzweiterbildung „Spezielle Wirbelsäulenchirurgie“ sein könnte.
Chirurgische Ausbildung im digitalen Zeitalter – Virtual Reality, Augmented Reality und Robotik im Medizinstudium
Authors: Kuhn Sebastian , Huettl Florentine , Deutsch Kim , Kirchgässner Elisa , Huber Tobias , Kneist Werner
Published: February 2021

Hintergrund Die digitale Transformation der Medizin verändert den Beruf des Arztes. Augmented und Virtual Reality (AR/VR) und die Robotik erfahren einen zunehmenden Einsatz in unterschiedlichen klinischen Kontexten und bedürfen einer begleitenden Aus- und Weiterbildung, die bereits im Medizinstudium beginnen muss. Hier besteht aktuell eine große Diskrepanz zwischen dem hohen Bedarf und der Anzahl an wissenschaftlich überprüften Konzepten. Ziel der vorliegenden Arbeit war die Konzeptionierung und strukturierte Evaluation eines neu entwickelten Lern-/Lehrkonzepts zur digitalen Transformation mit Fokus auf die chirurgische Lehre.

Methoden 35 Studierende haben in 3 Kursen des Blended-Learning-Curriculums „Medizin im digitalen Zeitalter“ teilgenommen. Das 4. Modul dieses Kurses thematisiert Virtual Reality, Augmented Reality und Robotik in der Chirurgie. Es gliedert sich in die folgenden Kursteile: (1) immersive Simulation einer laparoskopischen Cholezystektomie, (2) leberchirurgische Operationsplanung mittels AR/VR, (3) Basisfertigkeiten am VR-Simulator für robotische Chirurgie, (4) kollaborative OP Planung im virtuellen Raum und (5) Expertengespräch. Nach Abschluss des Gesamtcurriculums erfolgte eine qualitative und quantitative Evaluation des Kurskonzepts mittels semistrukturierter Interviews sowie anhand von standardisierten Prä-post-Evaluationsfragebögen.

Ergebnisse Im qualitativen Auswertungsverfahren der Interviews wurden 79 Textaussagen 4 Schwerpunktkategorien zugewiesen. Den größten Anteil (35%) nahmen hierbei Äußerungen zum „Expertengespräch“ ein, das von den Studierenden als elementarer Teil des Kurskonzepts gewertet wurde. Darüber hinaus empfanden die Studierenden den Kurs als horizonterweiterndes „Lernerlebnis“ (29% der Aussagen) mit einem hohen „Praxisbezug“ (27%). Die quantitative Studierendenevaluation zeigt eine positive Entwicklung für die Teilkompetenzen Wissen und Fertigkeiten sowie eine Tendenz zu einer positiven Haltung nach Kursabschluss.

Schlussfolgerung Die chirurgische Lehre ist zur Entwicklung digitaler Kompetenzen prädestiniert. Dabei muss die Geschwindigkeit des Veränderungsprozesses der digitalen Transformation im chirurgischen Fachgebiet beachtet und im curricularen Konzept verankert werden.
EBV-positive MTX-assoziierte lymphoproliferative Erkrankung und IgM-Myelom bei rheumatoider Arthritis
Authors: Wernecke Marie , Frieling David , Brandl Ulrike , Feller Alfred , von Wichert Götz
Published: February 2021

Anamnese Eine 80-jährige Patientin stellte sich mit einer ausgeprägten Lymphadenopathie und Gewichtsverlust vor. Vorbekannt war eine seit 6 Jahren bestehende rheumatoide Arthritis. Es bestand eine basistherapeutische Behandlung mit Methotrexat (MTX) 10 mg 1-mal/Woche.

Untersuchungen und Diagnose Anhand einer Lymphknotenbiopsie konnte eine klonale Vermehrung sowohl von EBV-positiven B- als auch T-Zellen nachgewiesen werden. Eine neu aufgetretene Anämie (Hb 10 g/dl), eine monoklonale Gammopathie vom Isotyp IgM sowie der Nachweis von 40 % EBV-positiven Plasmazellen im Knochenmark waren vereinbar mit der Diagnose eines IgM-Myeloms. Wir interpretierten dies als biklonale Epstein-Barr-Virus-induzierte MTX-assoziierte lymphoproliferative Erkrankung (MTX-LPD).

Therapie und Verlauf Unmittelbar nach Absetzen von Methotrexat konnte eine relevante klinische Besserung beobachtet werden. In der Verlaufskontrolle nach 4 Monaten war die Gammaglobulin-Konzentration im Serum deutlich reduziert (von 51,1 auf 34,7 %) und eine erneute Immunelektrophorese des Serums war ohne Nachweis einer monoklonalen Gammopathie.

Folgerung Anhand dieses Falls lässt sich die Assoziation einer RA mit lymphoproliferativen Erkrankungen bestätigen – hier als Assoziation einer RA mit einer biklonalen MTX-LPD bzw. einem Multiplen Myelom. Eine Therapie mit MTX sowie die Reaktivierung einer EBV-Infektion stellen dabei wichtige Einflussfaktoren dar.
Utility of Intraoperative Ultrasound in Neurosurgery
Authors: Faria Méndez Gustavo Enrique , Roa Chacón César José , Brito Núñez Nafxiel Jesus , Zerpa José Ramón
Published: February 2021

Objective The purpose of the present study is to demonstrate the usefulness of intraoperative ultrasound guidance as a technique for the assessment, in real time, of tumor resection and as a navigation aid during intra-axial brain lesion removal on patients admitted in the Neurosurgical Department at the Hospital Universitario de Caracas, Caracas, Venezuela, in 2018.

Methods A total of 10 patients were enrolled, each with intra-axial brain lesions with no previous neurosurgical procedures and a mean age of 49 years old, ranging from 29 to 59 years old.

Results A male predominance was observed with 7 cases (70%) over 3 female cases (30%). Six patients had lesions in the dominant hemisphere. The frontal lobe was the most commonly affected, with 5 cases, followed by the parietal lobe, with 4 cases. After craniotomy, ultrasound evaluation was performed previously to dural opening, during tumor resection and after tumor removal. The mean tumor size in axial, coronal and sagittal views was 3.72 cm, 3.08 cm and 3.00 cm, respectively, previously to dural opening with intraoperative ultrasound. The average tumor depth was 1.73 cm from the cerebral cortex. The location and removal duration from the beginning of the approach (ultrasound usage time) was 83.60 minutes, and the average surgery duration was 201 minutes. Navigation with intraoperative ultrasound served to resect intra-axial tumors more precisely and safely. There was no postoperative complication associated with the surgery in this series of cases.

Conclusions Intraoperative ultrasound guidance for intra-axial subcortical tumor resection is a technique that serves as a surgical and anatomical orientation tool.
Conversation Training Therapy: Let's Talk It Through
Authors: Gartner-Schmidt Jackie , Gillespie Amanda I.
Published: February 2021

This article introduces a novel approach to voice therapy called conversation training therapy (CTT). CTT is the first voice therapy approach to remove the therapeutic hierarchy common in most treatment programs. Rather, CTT uses patient-driven conversation as the sole stimuli in therapy to increase perceptual awareness of voice production in conversational speech. The genesis as to why CTT was developed, as well as the conceptual, theoretical, and component parts of CTT, will be explained. In addition, this article will offer examples of the language of therapy, as it applies to CTT and how to trouble-shoot if problems arise. Medical documentation relevant to CTT will also be outlined. Last, results from a recent efficacy study on CTT will be reported.
Phonogenic Voice Problems among Speech-Language Pathologists in Synchronous Telepractice: An Overview and Recommendations
Authors: Knickerbocker Kristie , Bryan Cara , Ziegler Aaron
Published: February 2021

Many speech-language pathologists (SLPs) recently adopted a live, synchronous online distribution of clinical services due to physical distancing measures aimed at bringing the coronavirus disease 2019 (COVID-19) outbreak under control. Few SLPs had received training in telepractice to prepare them for changes from an in-person service delivery model to synchronous telepractice. The new telepractice environment may alter vocal behaviors and communication interactions in such a way that negatively impacts voice production. Thus, delivering synchronous online clinical services may require that SLPs adopt novel prevention strategies for avoiding phonogenic voice problems. Guided by two complementary injury frameworks, the Haddon Matrix and the Haddon Countermeasures, this article provides an overview of potential factors associated with phonogenic voice problems among SLPs in telepractice and proposes possible prevention strategies to maintain optimal vocal health and function with synchronous modes of online clinical practice.
Role of Photo-Biomodulation Therapy in Facial Rejuvenation and Facial Plastic Surgery
Authors: De Cordova Jose A.
Published: February 2021

Photo-biomodulation (PBM) also known as low-level laser therapy is a rising technology with multiple potential uses in medicine and recently in the cosmetic field for the treatment of skin conditions and skin rejuvenation. Due to its wound healing and anti-inflammatory properties, there is an increase in popularity in its use as adjunctive treatment before and after surgical procedures in the face and neck.
Telehealth: Could It Be an Avenue to Microvascular Breast Reconstruction for Patients with Geographical Barriers?
Authors: Colakoglu Salih , Johnson Ariel , Mureau Marc A.M. , Douglass Sara , Kaoutzanis Christodoulos , Chong Tae W. , Mathes David W. , Cohen Justin B.
Published: February 2021

Background All women undergoing a mastectomy have the right to reconstruction. However, many women do not receive reconstruction and many more are not aware of all the reconstructive options available to them. Travel distance to a center that provides reconstruction and subsequent follow-up may be a contributing factor to this disparity especially among those who seek microsurgical options. Telehealth, which provides patients with remote video consultations and decreases the travel burden, may be a solution to optimize the accessibility of breast reconstruction for these patients. The purpose of this study was to discuss the efficacy and reliability of telehealth to overcome geographic barriers.

Methods Patients who received breast reconstruction and participated in video telehealth visits between February and May 2020 were included in this study. Patient demographics, comorbidities, and clinical outcomes were collected. Video telehealth encounters were reviewed to determine specific concerns and questions discussed during these encounters.

Results A total of 235 breast reconstruction surgery patient encounters were recorded for 4 plastic surgeons who offer microsurgical breast reconstruction. Eighty-eight patients (37.4%) were seen as telehealth visits, 20 (22.7%) of which were new patient visits. Eight (9.09%) patients were microsurgical breast reconstruction candidates and 25 (28.4%) were following-up after microsurgical breast reconstruction. The majority of telehealth visits included normally healing wounds in the postoperative patient.

Conclusion Telehealth provides an avenue for premastectomy consultation, second opinion visits, and postoperative follow-up for patients who have geographical barriers precluding them from reaching plastic surgeons who perform all types of breast reconstruction.
Development of interface-/surface-specific two-dimensional electronic spectroscopy
Authors: Deng Gang-Hua , Wei Qianshun , Qian Yuqin , Zhang Tong , Leng Xuan , Rao Yi
Published: February 2021

Structures, kinetics, and chemical reactivities at interfaces and surfaces are key to understanding many of the fundamental scientific problems related to chemical, material, biological, and physical systems. These steady-state and dynamical properties at interfaces and surfaces require even-order techniques with time-resolution and spectral-resolution. Here, we develop fourth-order interface-/surface-specific two-dimensional electronic spectroscopy, including both two-dimensional electronic sum frequency generation (2D-ESFG) spectroscopy and two-dimensional electronic second harmonic generation (2D-ESHG) spectroscopy, for structural and dynamics studies of interfaces and surfaces. The 2D-ESFG and 2D-ESHG techniques were based on a unique laser source of broadband short-wave IR from 1200 nm to 2200 nm from a home-built optical parametric amplifier. With the broadband short-wave IR source, surface spectra cover most of the visible light region from 480 nm to 760 nm. A translating wedge-based identical pulses encoding system (TWINs) was introduced to generate a phase-locked pulse pair for coherent excitation in the 2D-ESFG and 2D-ESHG. As an example, we demonstrated surface dark states and their interactions of the surface states at p-type GaAs (001) surfaces with the 2D-ESFG and 2D-ESHG techniques. These newly developed time-resolved and interface-/surface-specific 2D spectroscopies would bring new information for structure and dynamics at interfaces and surfaces in the fields of the environment, materials, catalysis, and biology.
Experimental characterization of a one-dimensional nonreciprocal acoustic metamaterial with anti-parallel diodes
Authors: Raval S. , Petrover K. , Baz A.
Published: February 2021

Characterization of a newly developed class of passive nonreciprocal acoustic metamaterials is presented in an attempt to quantify their ability of controlling the flow and distribution of acoustic energy in acoustic cavities and systems. The proposed nonreciprocal acoustic metamaterial (NAMM) cell consists of a one-dimensional acoustic cavity provided with piezoelectric flexible boundaries connected to an array of anti-parallel diodes to introduce the nonlinear damping effect that tends to break the reciprocity of the energy flow through the NAMM cell. A comprehensive experimental characterization of prototypes of the NAMM cells is presented here in order to investigate the effect of various anti-parallel diode arrangements on the nonreciprocal behavior of the cell. Furthermore, the experimental characterization aims also at demonstrating the effectiveness of the proposed NAMM in tuning the directivity, flow, and distribution of acoustic energy propagating through the metamaterial.
Understanding biological control with entomopathogenic fungi—Insights from a stochastic pest–pathogen model
Authors: Djouda Byliole S. , Ndjomatchoua Frank T. , Moukam Kakmeni F. M. , Tchawoua Clément , Tonnang Henri E. Z.
Published: February 2021

In this study, an individual-based model is proposed to investigate the effect of demographic stochasticity on biological control using entomopathogenic fungi. The model is formulated as a continuous time Markov process, which is then decomposed into a deterministic dynamics using stochastic corrections and system size expansion. The stability and bifurcation analysis shows that the system dynamic is strongly affected by the contagion rate and the basic reproduction number. However, sensitivity analysis of the extinction probability shows that the persistence of a biological control agent depends to the proportion of spores collected from insect cadavers as well as their ability to be reactivated and infect insects. When considering the migration of each species within a set of patches, the dispersion relation shows a Hopf-damped Turing mode for a threshold contagion rate. A large size population led to a spatial and temporal resonant stochasticity and also induces an amplification effect on power spectrum density.
Dynamics of magnetic islands driven by ballooning turbulence
Authors: Dubuit N. , Agullo O. , Muraglia M. , Frank J. , Garbet X. , Maget P.
Published: February 2021

Magnetic island generation by remote ballooning turbulence close to the plasma edge is investigated through flux-driven 3D Reduced-MHD simulations. Various coupling mechanisms are investigated: mono-helicity nonlinear coupling, multi-helicity nonlinear coupling, and linear toroidal coupling. The dominant process depends on the imposed heat flux driving the turbulence. The remote drive occurs in two successive phases corresponding to different coupling paths. While an island is remotely generated in both phases, it is dominated by different mode numbers, or harmonics, and, therefore, has a different shape. The size of the generated island is found to be proportional to the imposed heat flux, without threshold. The shape of the island in the saturated regime also depends on the imposed heat flux, with a more distorted shape at low power levels.
Noise-driven multistability vs deterministic chaos in phenomenological semi-empirical models of whole-brain activity
Authors: Piccinini Juan , Ipiñna Ignacio Perez , Laufs Helmut , Kringelbach Morten , Deco Gustavo , Sanz Perl Yonatan , Tagliazucchi Enzo
Published: February 2021

An outstanding open problem in neuroscience is to understand how neural systems are capable of producing and sustaining complex spatiotemporal dynamics. Computational models that combine local dynamics with in vivo measurements of anatomical and functional connectivity can be used to test potential mechanisms underlying this complexity. We compared two conceptually different mechanisms: noise-driven switching between equilibrium solutions (modeled by coupled Stuart–Landau oscillators) and deterministic chaos (modeled by coupled Rossler oscillators). We found that both models struggled to simultaneously reproduce multiple observables computed from the empirical data. This issue was especially manifested in the case of noise-driven dynamics close to a bifurcation, which imposed overly strong constraints on the optimal model parameters. In contrast, the chaotic model could produce complex behavior over a range of parameters, thus being capable of capturing multiple observables at the same time with good performance. Our observations support the view of the brain as a non-equilibrium system able to produce endogenous variability. We presented a simple model capable of jointly reproducing functional connectivity computed at different temporal scales. Besides adding to our conceptual understanding of brain complexity, our results inform and constrain the future development of biophysically realistic large-scale models.
Prototype system of noninterferometric phase-contrast computed tomography utilizing medical imaging components
Authors: Wu Z. , Wei W. B. , Gao K. , Liu G. , Liu G. F. , Sun H. X. , Jiang J. , Wang Q. P. , Lu Y. L. , Tian Y. C.
Published: February 2021

Grating-based x-ray phase-contrast imaging has been demonstrated to provide more information and higher-contrast images for low-Z soft tissues, compared with conventional absorption-based imaging. However, the existing Talbot–Lau phase-contrast devices are operated in either a two- or three-dimensional mode at low energy with a small field of view and long exposure time. This is because of coherence limitations, difficulties in fabricating high aspect ratio gratings, and the slow readout speed of the detector. For preclinical or even clinical applications, a variable x-ray energy, a large field of view, and fast phase-contrast computed tomography (CT) devices are desirable. The noninterferometric grating-based phase-contrast imaging method is a good candidate, as it relaxes requirements on gratings, including grating period and aspect ratio. Based on the noninterferometric imaging principle, we constructed a prototype phase-contrast CT system, at the National Synchrotron Radiation Laboratory of the University of Science and Technology of China, with medical imaging components. This prototype system enables a large field of view and fast phase-contrast CT imaging under medical imaging energies. In this paper, the prototype system and preliminary experimental results are reported, and possible optimization for forthcoming work is also discussed.
Role of strain and composition on the piezoelectric and dielectric response of AlxGa1−xN: Implications for power electronics device reliability
Authors: Mishra Saswat , Guda Vishnu Kathik , Strachan Alejandro
Published: February 2021

Gallium nitride (GaN) and AlxGa1−xN, its solid solution with Al, play a vital role in a variety of high-power applications owing to their high breakdown voltage, drift velocity, and sheet charge density. Their piezoelectric nature is critical for both the operation and reliability of GaN-based devices, and this is compounded by the lack of lattice-matched substrates and the lattice mismatch between GaN and AlxGa1−xN, which invariably results in strained films. Thus, accurate models of performance and reliability require knowledge of how strain affects dielectric and piezoelectric response. We used density functional theory to calculate the piezoelectric and dielectric constants for different compositions of AlxGa1−xN as a function of biaxial strain and use Gaussian process regression to develop models, including uncertainties, from the ab initio results. We find that the dielectric constants decrease with compressive biaxial strain and increasing Al content due to an increase in phonon frequencies. Meanwhile, the piezoelectric constants increase with compressive biaxial strain and with Al doping. Our results show that the presence of strain can explain discrepancies in experimental measurements of dielectric constants but not piezoelectric ones. Interestingly, the piezoelectric constants e33 and e31 (which control the elastic energy induced by the application of gate voltage in GaN high electron mobility transistors, which have been related to their degradation) vary by almost 100% within a biaxial strain range of ∼3%. These results indicate that incorporating strain-dependent and composition-dependent piezoelectric response into current degradation models based on inverse piezoelectricity is crucial for accurate reliability predictions in GaN-based transistors.
DFT based first principles study of novel combinations of perovskite-type hydrides XGaH3 (X = Rb, Cs, Fr) for hydrogen storage applications
Authors: Khalil R. M. Arif , Hayat Shafqat , Hussain Muhammad Iqbal , Rana Anwar Manzoor , Hussain Fayyaz
Published: February 2021

Hydrogen storage has become a challenge for researchers of this era because it is a cheap, clean, and non-pollutant element existing in nature. The current study has been performed in order to calculate the structural, electronic, optical, and magnetic properties of perovskite hydrides XGaH3 (X = Rb, Cs, Fr) through the Cambridge serial total energy package code based on density functional theory. The comprehensive investigations have been made while utilizing three cations (Rb, Cs, and Fr) in the cubic form of the ABH3 symmetry phase. The electronic properties of the considered hydrides have been investigated to determine bandgap, total density of states, and partial density of states, and their trends are devised against frequency (eV) of incident radiations. XGaH3 hydrides have shown metallic behavior because no energy bandgap is noticed near the Fermi level. The lattice constants of RbGaH3, CsGaH3, and FrGaH3 by utilizing the Perdew–Burke–Ernzerhof-Generalized Gradient Approximation (PBE + GGA) functional are found to be 4.0754 Å, 4.2137 Å, and 3.1237 Å. The local density approximation functional has also been used for calculations of lattice parameters, which are observed to be 3.9287 Å, 4.0673 Å, and 3.9818 Å, respectively. Anti-ferromagnetism is observed through magnetic analysis of the studied hydrides XGaH3 (X = Rb, Cs, Fr). Regarding the optical analysis, FrGaH3 is found to be a more suitable material for hydrogen storage. These novel materials exhibit minimum energy loss with maximum conductivity. The gravimetric ratio for hydrogen storage capacity is determined to be 2.5 wt. %, 2.0 wt. %, and 2.1 wt. % for RbGaH3, CsGaH3, and FrGaH3, respectively. The present computational calculations of these hydrides are attempted for the first time, which may provide exceptional improvements for applications in hydrogen storage.
Atomistic insight towards the impact of polymer architecture and grafting density on structure-dynamics of PEGylated bovine serum albumin and their applications
Authors: Munasinghe Aravinda , Mathavan Akash , Mathavan Akshay , Lin Ping , Colina Coray M.
Published: February 2021

Macromolecules such as proteins conjugated to polyethylene glycol (PEG) have been employed in therapeutic drug applications, and recent research has emphasized the potential of varying polymer architectures and conjugation strategies to achieve improved efficacy. In this study, we performed atomistic molecular dynamics simulations of bovine serum albumin (BSA) conjugated to 5 kDa PEG polymers in an array of schemes, including varied numbers of attached chains, grafting density, and nonlinear architectures. Nonlinear architectures included U-shaped PEG, Y-shaped PEG, and poly(oligoethylene glycol methacrylate) (POEGMA). Buried surface area calculations and polymer volume map analyses revealed that volume exclusion behaviors of the high grafting density conjugate promoted additional protein–polymer interactions when compared to simply increasing numbers of conjugated chains uniformly across the protein surface. Investigation of nonlinear polymer architectures showed that stable polymer-lysine loop-like conformations seen in previous conjugate designs were more variable in prevalence, especially in POEGMA, which contained short oligomer PEG chains. The findings of this comprehensive study of alternate PEGylation schemes of BSA provide critical insight into molecular patterns of interaction within bioconjugates and highlight their importance in the future of controlled modification of conjugate system parameters.
Instrument for in situ hard x-ray nanobeam characterization during epitaxial crystallization and materials transformations
Authors: Marks Samuel D. , Quan Peiyu , Liu Rui , Highland Matthew J. , Zhou Hua , Kuech Thomas F. , Stephenson G. Brian , Evans Paul G.
Published: February 2021

Solid-phase epitaxy (SPE) and other three-dimensional epitaxial crystallization processes pose challenging structural and chemical characterization problems. The concentration of defects, the spatial distribution of elastic strain, and the chemical state of ions each vary with nanoscale characteristic length scales and depend sensitively on the gas environment and elastic boundary conditions during growth. The lateral or three-dimensional propagation of crystalline interfaces in SPE has nanoscale or submicrometer characteristic distances during typical crystallization times. An in situ synchrotron hard x-ray instrument allows these features to be studied during deposition and crystallization using diffraction, resonant scattering, nanobeam and coherent diffraction imaging, and reflectivity. The instrument incorporates a compact deposition system allowing the use of short-working-distance x-ray focusing optics. Layers are deposited using radio-frequency magnetron sputtering and evaporation sources. The deposition system provides control of the gas atmosphere and sample temperature. The sample is positioned using a stable mechanical design to minimize vibration and drift and employs precise translation stages to enable nanobeam experiments. Results of in situ x-ray characterization of the amorphous thin film deposition process for a SrTiO3/BaTiO3 multilayer illustrate implementation of this instrument.
High-power mid-wave infrared LED using W-superlattices and textured surfaces
Authors: Montealegre D. A. , Schrock K. N. , Walhof A. C. , Muellerleile A. M. , Prineas J. P.
Published: February 2021

Efficient mid-infrared light output has been obtained by incorporating a W-superlattice into a cascaded mid-infrared LED structure and by thinning and roughening of the emission side of the structure. At cryogenic temperatures, a radiance of ∼13.4 W/cm2-sr is achieved. Compared to the best published InAs/GaSb mid-IR LED, the maximum radiance is improved by ∼2.0×, while the wallplug efficiency improvement at the maximum radiance is improved >10×. For room temperature measurements on an un-thinned 400 μm diameter diode, the radiance (light output power) for a quasi-continuous wave and 1% duty cycle were ∼ 0.48 W/cm2-sr (2.4 mW) and ∼1.35 W/cm2-sr (6.8 mW), respectively. When compared to previous room temperature 4.2 μm LEDs, at a 1% duty cycle, this LED has optical powers that are 3× brighter. When compared to thermal emitters used in gas sensors, in the quasi-continuous wave, this LED uses ∼100× less energy per measurement.
A sub-4 Kelvin radio frequency linear multipole wire trap
Authors: Geistlinger Katharina , Fischer Moritz , Spieler Steffen , Remmers Lena , Duensing Felix , Dahlmann Franziska , Endres Eric , Wester Roland
Published: February 2021

A linear cryogenic 16-pole wire ion trap has been developed and constructed for cryogenic ion spectroscopy at temperatures below 4 K. The trap is temperature-variable, can be operated with different buffer gases, and offers large optical access perpendicular to the ion beam direction. The housing geometry enables temperature measurement during radio frequency operation. The effective trapping potential of the wire-based radio frequency trap is described and compared to conventional multipole ion trap designs. Furthermore, time-of-flight mass spectra of multiple helium tagged protonated glycine ions that are extracted from the trap are presented, which prove very low ion temperatures and suitable conditions for sensitive spectroscopy.
Expansion of ultracold neutral plasmas with exponentially decaying density distributions
Authors: Warrens M. K. , Gorman G. M. , Bradshaw S. J. , Killian T. C.
Published: February 2021

We present a study of the expansion of an ultracold neutral plasma (UCNP) with an initial density distribution that decays exponentially in space, created by photoionizing atoms shortly after their release from a quadrupole (or biconic cusp) magnetic trap. A characteristic ion acoustic timescale is evident in the evolution of the plasma size and velocity, indicating that the dynamics are reasonably well described by a model of hydrodynamic expansion of a quasi-neutral plasma. However, for low plasma density and high initial electron temperature, excess ion kinetic energy in the vicinity of the central density peak suggests significant local non-neutrality at early times. Observations are compared to the well-understood self-similar expansion of a UCNP with an initial Gaussian density distribution, and a similar scaling law describes the evolution of plasma size for both cases.
Cutoff low over the southeastern Pacific Ocean: a case study
Authors: Quispe-Gutiérrez Nelson , Aliaga-Nestares Vannia , Rodríguez-Zimmermann Diego , Bonshoms Martí , Loayza Raquel , García Teresa , Mesia José , Duran Ricardo , Olivares Sara
Published: February 2021

Cutoff lows (COLs) are infrequent events in the tropics that can cause extreme rainfall, flash flooding and landslides in arid areas, such as western South America. In this study, the life cycle of a COL in the southeastern Pacific at the beginning of April 2012 was analysed using the ERA-Interim reanalysis dataset. This paper examines: (1) the precursor flow evolution prior to the COL, its development and dissipation by applying the quasi-geostrophic and vorticity equations; and (2) the influence of the COL in the heavy precipitation events over the western Peruvian Andes. During April 2012, the highest amount of precipitation was recorded in Chosica (850 masl) with 37 mm on 5 April. Days prior to the formation of the COL, a subtropical trough deepened by the amplification of a ridge over the tropical Pacific and the incursion of cold air from medium and low levels into the trough. The strong cyclonic vorticity advection was intensified by a short-wave trough embedded inside a long-wave one that strengthened the system on 5 April 2012. In the dissipation stage, warm vertical advection predominated, resulting in the reabsorption of the COL by a new trough. Understanding the behaviour COL systems is important for reducing the impact of these extreme weather events on lives and infrastructure in densely populated areas.
Stable reliability diagrams for probabilistic classifiers
Authors: Dimitriadis Timo , Gneiting Tilmann , Jordan Alexander I.
Published: February 2021

Significance

Probabilistic classifiers assign predictive probabilities to binary events, such as rainfall tomorrow, a recession, or a personal health outcome. Such a system is reliable or calibrated if the predictive probabilities are matched by the observed frequencies. In practice, calibration is assessed graphically in reliability diagrams and quantified via the reliability component of mean scores. Extant approaches rely on binning and counting and have been hampered by ad hoc implementation decisions, a lack of reproducibility, and inefficiency. Here, we introduce the CORP approach, which uses the pool-adjacent-violators algorithm to generate optimally binned, reproducible, and provably statistically consistent reliability diagrams, along with a numerical measure of miscalibration based on a revisited score decomposition.
Peripheral sensory stimulation elicits global slow waves by recruiting somatosensory cortex bilaterally
Authors: Rosenthal Zachary P. , Raut Ryan V. , Bowen Ryan M. , Snyder Abraham Z. , Culver Joseph P. , Raichle Marcus E. , Lee Jin-Moo
Published: February 2021

Significance

Slow waves are the predominant feature of brain activity during sleep and anesthesia. Slow waves are associated with plasticity, memory consolidation, and other brain functions. However, much remains unknown about the brain circuits that coordinate slow wave propagation. Here, we demonstrate that somatosensory stimulation evokes bilateral activation of primary somatosensory cortices (S1). Under anesthesia, S1 activation is followed by a global, front-to-back cortical slow wave. Using a focal lesion model, we show that evoked global slow waves depend on bilateral S1 activation, whereas spontaneous slow wave initiation does not depend on S1. These results demonstrate the existence of mechanisms by which focal injury may disrupt brain network dynamics.
Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides
Authors: Prajapati Aditya , Collins Brianna A. , Goodpaster Jason D. , Singh Meenesh R.
Published: February 2021

Significance

The electrochemical conversion of CH
4
to liquid fuel such as CH
3
OH offers a sustainable and environmentally benign route to utilize shale gas. This process requires controlled oxidation by optimal splitting and formation of C–H and C–O bonds to produce desired products at ambient conditions, which has been a long-standing challenge in electrocatalysis of hydrocarbons. Here, we combine electrochemical experiments with quantum chemical calculations to develop activity descriptors for identification of efficient electrocatalysts that can partially oxidize CH
4
to CH
3
OH. This work provides much deeper insights into potential-driven breakage/formation of C–H and C–O bonds, which will greatly advance the scientific understanding of hydrocarbon electrochemistry.
Pæn, flot, dejlig, andlækker
Authors: Levisen Carsten
Published: February 2021

This paper examines the Danish language of aesthetics from the perspective of four untranslatable adjectives:pæn, flot, dejlig, andlækker. These words are frequent and salient in everyday discourses, and as such they shed light on Danish “folk” conceptions. From the perspective of Lexical Anthropology and NSM Semantics, each of the words are explored and explicated in order to shed light on the ways in which Danish discourse organize positive aesthetic experiences. Sensitive to polysemy, and the variety of lexicogrammatical frames in which the words occur, the paper provides a high-resolution analyses of the “something ADJ frame” which enables discourses of design, food, and art. Based on lexical semantic evidence, the paper locates two themes in Danish discourse: “aesthetic normality” and “ordinary hedonism” which seem to act as cognitive axes around which discourses revolve. The paper argues that words hold the key to understanding the diversity of aesthetic cultures, and that untranslatables in particular, allow for a deep emic understanding of how local configurations of seeing, feeling, touching, and thinking are constituted.
納西語音節弱化與合音
Authors: He Likun , Liu Yan
Published: February 2021

抽象的

前賢認為納西語某些高調音節（虛詞）完全丟失音段弱化為「浮游調」使左鄰音節（宿主）變調。重新考察此現象發現音節弱化在現代納西語中很普遍，弱化並不限於高調音節，弱化後宿主產出非常豐富的音變形式，一共十二種。雖然這與浮游調引起的變調極為相似，但音節弱化並不產生典型的浮游調。納西語音節弱化與合音音變的研究為描寫複雜變調提供了框架，同時為浮游調歷史來歷與演變路徑、詞彙化和語法化過程中音節的演變提供了線索。
現代台灣客語與「分佢」相關的致使結構之語法和語意特點
Authors: Yeh Jui-chuan
Published: February 2021

抽象的

從現代台灣地區客語出發，佐以巴色會客語和跨漢語方言中關於雙及物結構的考察，本文討論客語中由「分佢」和結果式動補（V-R）結構互動所產生的致使結構，並聚焦於「分佢」出現在V和R之中和之後的例子。本文主要觀點如下：第一，「分佢」句式表達言者主觀性，凸顯說話者的意志，但此特點不是因為「我者」視角，而是來自於構式本身；第二，「分佢」句式的複句性質仍然存在，但在語法化的路徑上，整個構式逐漸演變成單子句結構，其中的關鍵在於「佢」的指稱限制降低，經歷了「單數指稱>兼具單數、複數指稱>複數指稱>泛稱>無指稱」等演變階段，這造成了主語的泛化，帶動句式的整體變化，而隨著使用頻率的提高，「分佢」甚至合音成bi2
，演變成單一的語法標記，單子句的性質益發明顯；第三，「分佢」致使結構不是構詞型，而是分析型；第四，「分佢」在這些結構中的句法位置和雙賓A和B式中接收者的位置有關，非因語意冗贅而產生的自由變換、非取決於R的語義指向、也非源自於雙及物結構中的介賓補語式和複合詞式中「分+賓語」的位置。
Dynamic Variation in Second Language Acquisition
Authors: Dyson Bronwen Patricia
Published: February 2021

Dynamic Variation in Second Language Acquisition makes a cutting-edge contribution to knowledge about how second language learners develop their second language. Drawing comprehensively on Processability Theory’s theoretical understanding that individual variation dynamically interacts with ordered stages of language acquisition, the book provides an informative, critical analysis of historical and contemporary debates about the role of variation in linguistic variation, particularly second language variation. Richly illustrated with a forensic year-long study of how eight adolescent learners of English vary in their acquisition of syntax and morphology, this monograph shows that learners vary in their timing of development between two distinct learner types along a continuum and without skipping stages. The book uncovers how learner variation is dynamic and quite (although not entirely) systematic and how this variation contributes to change in the second language. It will be essential reading for researchers, students, and practitioners.
Yielding behaviour and Hall­–Petch relationship in ultrafine-grained Al–Mg binary alloys
Authors: Kamikawa Naoya , Hirooka Toyohisa , Furuhara Tadashi
Published: February 2021

This study investigates yielding behaviour, Hall–Petch relationship and strengthening mechanism of ultrafine-grained Al–Mg binary alloys. Ultrafine-grained Al–Mg samples reveal unusual discontinuous yielding and extra Hall–Petch strengthening. The critical grain size to separate the extra Hall–Petch strengthening from the conventional Hall–Petch strengthening becomes larger as the Mg content is higher, indicating that dislocation sources in the ultrafine-grained structure becomes more difficult to activate by solute atoms of Mg. It is also found that the Lüders elongation in the discontinuous yielding becomes less pronounced by Mg addition, suggesting that enhancement of work hardening ability by addition of solute atoms is effective to avoid the occurrence of unwanted discontinuous yielding in ultrafine-grained metals.
Building a culture of deference: American Jewish givers, Israelis and control over donations to Israel, 1920–1989
Authors: Fleisch Eric
Published: February 2021

This article tells the story of duelling philosophies over money and power in the philanthropic relationship between American Jews and Israelis during the twentieth century. Its purpose is to provide one case study for how an affluent diaspora community and the leadership of the corresponding ethnic homeland viewed the roles each should play in allocating funds. It details the battle over two conflicting schools of thought for how best to control the nature and flow of American Jewish philanthropy to the Yishuv and early Israeli State. It then describes the extensive steps taken by the eventual winning side to entrench a culture of American deference to Israelis in allocations decision making as the dominant mode of philanthropic partnership in the second half of the twentieth century. The relationship dynamics and tactical measures employed in the battle over allocations discussed in this case provide a framework for analysing other similar homeland-diaspora philanthropic relationships.
Variability determinants of new consumption formats in the agricultural sector of the economy
Authors: Alekseev N E , Patlasov O Yu
Published: February 2021

This paper presents differentiates between new consumption formats. It also analyzes information platforms and collaborative consumption services. It is proved that the emergence of new consumption formats is both a consequence of economic science evolution and a reaction to the failures of the traditional economic system. The authorial list of structural changes determinants in the economy is defined. Some forecasts for collaborative consumption economy development are given. Modern economic reality allows us to conclude that the transformation has begun and there is a fundamental revision of the economic science foundations and the modern economy model, the search for a new, alternative economic development model based on the study of needs formation, development and satisfaction. There is a clearer relationship between the change in technology and changes in the structure of economic entities needs and consumption patterns. It is concluded that the extent of the sharing economy depends on the socio-demographic structure of the population.
Research of a conical pneumatic grain separator with a device for forced light fraction removal
Authors: Chernyakov A V , Koval V S , Yatsunov A N , Begunov M A , Shevchenko A P , Evchenko A V
Published: February 2021

The article studies a modernized conical air grain separator. It describes modern agricultural production and post-harvest grain processing in the north of Omsk region. The need for using new farm developments for cleaning grain is substantiated. The design of a modernized conical air grain separator is described. The modernization concerns the accelerated efficient removal of light impurities. Some modes of the system of forced removal of light fraction are effective when cleaning grain from light impurities using a conical air separator. The loss of high-grade grain may increase. To test the consistency of the hypothesis, two series of experiments were carried out. During the first series, the field of air flow velocities was investigated. It resembles a downward convex figure associated with the loss of air friction against the walls. During the second series, experiments on cleaning grain from impurities with the participation of a system for removing light impurities were conducted. A classic experiment with a conical air separator and a working system for removing light impurities was carried out and its results were processed. It was found that the height of the probe rise above the edge of the conical air separator, equal to 20 mm, gives the highest result when removing light impurities. The processes were interpreted and the results obtained were analyzed. A comparison of the quantitative and qualitative characteristics of the modernized separator with those of the classical one was carried out. It was found that the system of forced removal of light impurities is efficient: with fixed separation completeness, the performance of the separator increases 1.6 times.
The effect of particle motion on mixing intensity in a vibrating mixer
Authors: Yatsunov A N , Chernyakov A V , Koval V S , Shevchenko A P , Evchenko A V , Begunov M A
Published: February 2021

The intensity of mixing bulk materials, including feed, depends on technological parameters, kinematic and design parameters of the mixing plant, physical and mechanical properties of mixed components, etc. To study the process, a laboratory-experimental vibrating mixer was designed. The main working elements are vibration contact surfaces of various designs. It is possible to intensify the mixing process by influencing the nature of movement of particles along the mixing elements, including by giving them special shapes. In most cases, such a pattern can be traced: the more complex the particle trajectories, the higher the homogeneity of the finished feed mixture. The vibration contact surfaces can be divided into two groups, depending on their working surfaces. Mixing elements of the first group have holes or recesses. The holes can be as isosceles triangles, plates and concave are located at a certain angle under the holes. These surfaces are easy to manufacture, have low cost and material consumption and high productivity. It was revealed that at intensive operating modes, there is a decrease in the homogeneity of the mixture obtained. In this regard, when it is necessary to obtain highly homogeneous bulk feed mixtures, it is recommended to use mixing elements of the second group, which have protrusions on the working surfaces of various geometric shapes. The constructed theoretical trajectories of particle motion confirm the intensification of the mixing process. In addition, there are two ways of attaching the stirring elements, which give an additional effect. The laboratory-experimental mixer has been successfully tested in an agricultural organization preparing concentrates for feeding cattle.