bluuebunny/crossref_metadata_2025 huggingface dataset:
Der Einfluss von Industrie-Sponsoring auf Forschungsergebnisse
randomisierter klinischer Studien in der Plastischen und Ästhetischen
Chirurgie: Eine Querschnittsanalyse der letzten 12 Jahre
Authors: Alawi Seyed Arash , Grigorescu Oana , Bota Olimpiu , Dragu Adrian
Published: February 2023

Hintergrund Die Finanzierung von Forschungsprojekten im Fachbereich der
Plastischen, Rekonstruktiven und Ästhetischen Chirurgie wird zunehmend
durch Industrieunternehmen übernommen. Zielsetzung dieser Arbeit ist es,
randomisierte klinische Studien (RCTs) von führenden internationalen
Journalen für Plastische, Rekonstruktive und Ästhetische
Chirurgie zu untersuchen. Hierbei wurden die Kenndaten und die jeweils
zugrundeliegenden Studienergebnisse in Abhängigkeit zur Finanzierung
untersucht.

Material und Methoden Es erfolgte eine Auswertung der Kenndaten sowie der
Finanzierung von RCTs international führender plastisch-chirurgischer
Journale im Zeitraum Januar 2010 bis Januar 2022. Eine Kategorisierung wurde
zudem nach thematischen Schwerpunkten und den Ergebnissen im Hinblick auf
bestehende Finanzierungen durchgeführt.

Ergebnisse Insgesamt flossen die Daten von 381 RCTs in die Auswertung ein.
Von diesen waren 68,5% aus einer universitären Einrichtung
(n=261). Ein Großteil der Studien enthielt keine Angaben
über die zugrundeliegende Mittelherkunft. 26% der ausgewerteten
Forschungsstudien wurden durch Finanzmittel der Industrie gesponsort
(n=98) und in 9,7% durch die jeweilige
Universität/den Staat (n=37) (p<0,05,
95%-Konfidenzintervall). Der thematische Schwerpunkt der
durchgeführten Studien in privaten Praxen war Ästhetik
(n=32). Insgesamt wurden zum Thema der Ästhetik 28%
(n=153) der RCTs von der Industrie/private Träger vs.
9% Universität/Staat finanziert. Zum Thema
Rekonstruktion/Verbrennung/Handchirurgie wurden 9,2% der
Studien von der Industrie/privaten Trägern und 7,5% von
Universität/Staat finanziert. Die Finanzierung der Forschung
universitärer Einrichtungen wurde in 25% aus Mitteln der
Industrie beglichen (n=64). Von diesen industriegesponserten Studien
waren 73% (n=71) der Studienergebnisse konklusiv
produktfreundlich (p<0,05, 95%-Konfidenzintervall) und hatten
den thematischen Schwerpunkt der therapeutisch-medikamentösen
Anwendung/Produktanwendung (n=50, 75%).

Schlussfolgerung Bei der Finanzierung medizinischer Studien
übernehmen Industrie und private Träger sowohl im Bereich der
Rekonstruktion als auch der Ästhetik eine führende Rolle,
dennoch wird der größere Teil der Studien bisher nicht durch
diese finanziert. Erfolgte die Finanzierung jedoch durch Industrieunternehmen,
konnte signifikant ein positives Studienergebnis verzeichnet werden. Aktuell
wird der Themenbereich der Ästhetik durch die Industrie häufiger
finanziert als die Themenbereiche in der Rekonstruktion, Verbrennungs- und
Handchirurgie.
Differentielle Wirksamkeit einer internetbasierten
kognitiv-behavioralen Schreibtherapie zur Reduktion von PTBS-Symptomen nach
intensivmedizinischer Behandlung: Ergebnisse einer
Per-Protokoll-Analyse
Authors: Knaevelsrud Christine , Rosendahl Jenny , Reck Johannes , Gawlytta Romina , Kesselmeier Miriam , Böttche Maria , Niemeyer Helen
Published: February 2023

Ziel Es wurde die differentielle Wirksamkeit einer internetbasierten,
kognitiv-behavioralen Schreibtherapie (iCBT) zur Reduktion der Symptome einer
posttraumatischen Belastungsstörung (PTBS) bei intensivmedizinisch
behandelten Patient*innen und deren Partner*innen
untersucht.

Methodik Im Rahmen einer Reanalyse von Daten einer
randomisiert-kontrollierten Studie erfolgte der Vergleich der
PTBS-Symptomschwere (gemessen mittels PCL-5) vor und nach Therapie in der
Per-Protocol-Population in Abhängigkeit möglicher
Einflussfaktoren.

Ergebnisse Es zeigte sich eine signifikante Reduktion der
posttraumatischen Symptomschwere nach der Therapie. Elf von 25 behandelten
Teilnehmenden wiesen eine klinisch bedeutsame Veränderung (PCL-5
Differenz≥10 Punkte) auf. Die von den Teilnehmer*innen
geschriebene Wortzahl in den Therapiemodulen hatte einen signifikanten Einfluss
auf den Therapiererfolg.

Schlussfolgerung Die iCBT stellt eine vielversprechende Option zur
Erweiterung des Behandlungsspektrums bei PTBS, insbesondere für
körperlich eingeschränkte Patient*innen nach kritischer
Erkrankung dar.
Kompetenzprofil für Fachpersonen in der Suchthilfe und
Suchtprävention
Authors: Amberg Helen , Schumacher Jann
Published: February 2023

In der Schweiz verfügen die im Bereich Sucht tätigen Fachpersonen
über verschiedene Grundausbildungen, eine suchtspezifische
Grundausbildung gibt es nicht. Dennoch sollten Fachpersonen über
vielfältige spezifische Fähigkeiten verfügen, um in der
Suchtprävention oder Suchthilfe tätig zu sein. Aus diesem Grund
wurde ein sucht- und berufsgruppenübergreifendes Kompetenzprofil
entwickelt, welches grundlegende und weiterführende spezifische
Kompetenzen umfasst.
Button Battery Ingestions cause the Majority of Severe Complications
Authors: Kiefer Alexander , Duppel Uta , Schützenmeier Alexander , Lang Thomas , Kittel Jochen , Kabesch Michael , Kerzel Sebastian
Published: February 2023

Background Foreign body ingestion in children is a clinically important
reason for presentation to the emergency department. The individual outcome
ranges from benign spontaneous courses to severe complications. Fatal outcomes
occur rarely and complications are related to patient’s age as well as
type and location of the foreign body. The aim of our present study was to
evaluate the outcome of children and adolescents with foreign body ingestion
with a focus on complications, which mainly occurred after button battery
ingestion.

Methods We reviewed medical records of patients between 0 and 18 years of
age who had presented to the paediatric emergency department of our hospital
with suspected foreign body ingestion between January 2011 and March 2021 (123
months). Clinical, imaging, and endoscopic data as well as treatment modalities
were analysed.

Results In the ten10 year period under review, a total of 1,162 children
and adolescents (6 months – 18 years) presented to our emergency room
with suspected foreign body ingestion. Among those, 398 ingestions (34%)
could be verified radiologically and/or endoscopically, while in the
remaining 764 cases (66%) the suspicion could not be confirmed. The
majority of patients with verified ingestion (n=324; 81%)
presented with ingestion of a metallic foreign body. We observed 55 cases with
verified ingestion of a button battery. Five of these cases had severe
complications, with a near-fatal course in two patients who developed an
oesophageal-tracheal fistula.

Conclusion In contrast to all other ingestions of foreign bodies in
children, button battery ingestions lead to mucosal damage and severe
complications in a significant number of children.
Behandlungsoutcome von Maßregelpatient:innen mit
Migrationshintergrund. Analyse bayerischer Daten zur Qualitätserfassung
von 2010 bis 2019
Authors: Lutz Maximilian , Querengässer Jan , Bezzel Adelheid , Schlögl Christian , Streb Judith , Dudeck Manuela
Published: February 2023

Ziel der Studie Untersuchung des Zusammenhangs zwischen
Migrationshintergrund von Patient:innen und dem erfolgreichen Abschluss der
Maßregelbehandlung hinsichtlich Unterbringungsdauer und Entlassmodus

Methodik Auf Basis der Ergebnisqualitätserfassung des bayerischen
IFQM von 2010–2019 wurden mittels paarweiser Zuordnung Migrant:innen und
Nicht-Migrant:innen verglichen, die hinsichtlich folgender Variablen
übereinstimmen: Alter, Geschlecht, Hauptdiagnose und Indexdelikt

Ergebnisse In der Gruppe der Patient:innen, die gemäß
§ 63 StGB untergebracht waren, zeigten sich keine signifikanten
Unterschiede zwischen Migrant:innen und Nicht-Migrant:innen. In der Gruppe der
Patient:innen, die gemäß § 64 StGB untergebracht waren,
zeigten sich für Migrant:innen sowohl häufiger
Behandlungsabbrüche als auch eine tendenziell signifikant
kürzere Unterbringungsdauer bis zum Abbruch.

Schlussfolgerung Die Ergebnisse legen nahe, dass die Unterbringung
gemäß § 64 StGB für Migrant:innen weniger
erfolgreich ausfällt.
Control of Thyroid Dysfunction in Spanish Population Registered in
the Primary Care Clinical Database: An Analysis of the Proportion of Patients
with Thyrotropin Values Outside the Reference Range
Authors: Díez Juan J. , Iglesias Pedro
Published: February 2023

Inadequate control of thyroid dysfunction is common and has deleterious health
consequences. Our objective was to determine the prevalence of TSH values
outside the reference range, as an indicator of inadequate control of
hypothyroidism and hyperthyroidism in patients undergoing treatment for thyroid
dysfunction in Spain. An observational, retrospective, non-interventional study
was conducted using the Primary Care Clinical Database (BDCAP). Patients treated
with thyroid hormone for hypothyroidism and with antithyroid drugs for
hyperthyroidism were identified. We assessed serum TSH concentration,
considering values from 0.4 to 4.0 mU/l as the reference interval. We
found 360 313 people with hypothyroidism on thyroid hormone replacement and 9239
with hyperthyroidism on antithyroid drugs therapy. TSH values outside the
reference range in hypothyroid subject were detected in 126 866 (35.20%)
people, of whom 107 205 (29.75%) had TSH>4.0 mU/l,
suggesting inappropriately low doses of levothyroxine, and 19 661
(5.46%) had TSH<0.4 mU/l, suggesting inappropriate over
replacement. In the hyperthyroid group, TSH values outside the reference range
were observed in 4252 (46.02%) patients. There were 2833
(30.66%) patients with TSH<0.4 mU/l, suggesting
undertreatment, and 1419 (15.36%) with TSH>4.0 mU/l,
suggesting overtreatment with antithyroid medication. People over 65 years of
age had a lower frequency of undertreatment of hypothyroidism and a lower
frequency of overtreatment and undertreatment of hyperthyroidism. In conclusion,
our results suggest that inadequate control of thyroid dysfunction, due to its
high frequency and its consequences for health, is a public health problem that
should be addressed by clinicians and health authorities.
Ligand-Promoted Rosenmund–von Braun Reaction
Authors: Ma Dawei , Zhang Quan
Published: February 2023

Two picolinamide ligands were found to have significant accelerating effect to classical Rosenmund–von Braun reaction, making the coupling of (hetero)aryl bromides with CuCN occur at 100–120 °C with good to excellent yields in most cases. A large number of functional groups and heterocycles were tolerated under these conditions, thereby providing a convenient and reliable approach for diverse synthesis of aryl nitriles.
Bioinspired Total Syntheses of Gymnothelignans
Authors: Li Huilin , She Xuegong , Hong Xiaoling , Chen Peng
Published: February 2023

Since 2012, Xu and Zhou have reported the isolation of a series of gymnotheligans, a large group of novel tetrahydrofuran-containing lignan natural products. In the past decade, considerable achievements in the total syntheses of these lignans have been achieved based on a plausible biogenetic pathway proposed by our group in 2014. In this account, we summarize these remarkable synthetic works of the past ten years.

1 Introduction

2 Biogenetic Pathways to Gymnothelignans

3 Total Syntheses of Eupodienones

4 Total Syntheses of Eupomatilones

5 Total Synthesis of Dibenzocyclooctenes

6 Conclusions
Dark money, US security guarantees and the twisting of allied arms
Authors: Banka Andris
Published: February 2023

How can powerful states best extract domestic concessions from their junior allies? What are the conditions under which the powerful state is more likely to succeed in inducing such domestic policy change? This article explores the link between US security commitments and Washington’s ability to attain favourable policy outcomes within the allied domestic arena. It provides an illustrative case of how the USA, using security guarantees as leverage, can enter allied domestic space and shape its decision-making process. After it was revealed that Latvia had served as a key node through which North Korea attempted to evade the sanctions regime, the USA, by playing its security guarantor card, pressured Riga to carry out substantial policy reforms in relation to its financial system. This approach yielded considerable results. In order to preserve the existing security arrangements with the dominant alliance member, Latvia offered significant policy concessions. This finding demonstrates that US security alliances come with side benefits that are often underrated or neglected in the scholarly literature.
Salt fingers in a constricted channel
Authors: Shapiro Maura
Published: February 2023

Constriction of a channel dominates fluid flow and the salt finger, double-diffusive instability.
Compositional thermostatics
Authors: Baez John C. , Lynch Owen , Moeller Joe
Published: February 2023

We define a thermostatic system to be a convex space of states together with a concave function sending each state to its entropy, which is an extended real number. This definition applies to classical thermodynamics, classical statistical mechanics, quantum statistical mechanics, and also generalized probabilistic theories of the sort studied in quantum foundations. It also allows us to treat a heat bath as a thermostatic system on an equal footing with any other. We construct an operad whose operations are convex relations from a product of convex spaces to a single convex space and prove that thermostatic systems are algebras of this operad. This gives a general, rigorous formalism for combining thermostatic systems, which captures the fact that such systems maximize entropy subject to whatever constraints are imposed upon them.
Enhancing the precision of 3D sidewall measurements of photoresist using atomic force microscopy with a tip-tilting technique
Authors: Kizu Ryosuke , Misumi Ichiko , Hirai Akiko , Gonda Satoshi
Published: February 2023

A key issue associated with advanced lithography techniques for semiconductor-device manufacturing is the reduction in the sidewall roughness of photoresist line patterns, known as line-edge roughness (LER). We have developed a technique for measuring the sidewall of the resist pattern using atomic force microscopy (AFM) that enables three-dimensional (3D), high-resolution, low-noise, and nondestructive measurements. Conventional LER measurement technology using scanning electron microscopy (SEM) causes shrinkage of the resist pattern due to electron-beam (EB) exposure, whereas our new AFM technique can in principle avoid EB-induced shrinkage. This AFM technology is capable of 3D measurements because it employs a tip-tilting mechanism that enables the sharp AFM tip to scan the vertical sidewalls, which is difficult for a conventional AFM technique. In addition, laser interferometers are equipped for the measurement of the AFM tip displacement, which yields high-resolution, high-accuracy, and low-noise results. This technology overcomes issues such as low resolution, noise, and destructive measurements that afflict conventional SEM measurements. In addition, it enables observations and quantitative analyses of the 3D sidewall roughness. For example, in the present experiment, we observed that grain shapes (several tens of nm in size) were formed randomly on the resist sidewall and that there were almost no footing shapes. By analyzing the sidewall profiles with a height resolution of 1 nm, we obtain the roughness (self-affine fractal) parameters at each height. This AFM-based resist sidewall measurement technique can, thus, provide important insights into resist patterning and related process technologies for next-generation semiconductor-device manufacturing.
Accelerating ultrafast processes in hydrogen-bonded complexes under pressure
Authors: Li Qi , Zhu Lixia , Wan Yu , Wan Yongfeng , Gao Jianbo , Yin Hang , Shi Ying
Published: February 2023

Acceleration of ultrafast processes is vital in hydrogen-bonded coumarin–methanol complexes for improving the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs). The traditional methods expedite ultrafast processes individually related to electron injection in DSSCs, namely, internal conversion (IC) or intermolecular charge transfer (inter-CT), by adjusting molecular topologies. We introduce pressure as an external drive to realize the acceleration of both processes simultaneously without changing the configuration. In the definite hydrogen-bonded complexes, the acceleration of IC and inter-CT processes is visualized by in situ high-pressure femtosecond transient absorption spectroscopy. In liquid-phase methanol, the IC and inter-CT processes are actuated effectively from 150.20 to 59.21 fs and 93.95 to 29.05 ps, respectively. The quickening of both processes is attributed to the enhancement of intermolecular hydrogen bonds under pressure. After the pressure-induced methanol phase transition, the rates of IC and inter-CT processes at 3.67 GPa are increased by 36.42% and 80.55% compared to at 1.00 atm. Our study results open an enlightening avenue for boosting the photoelectric conversion efficiency of DSSCs.
Coexistence of volatile and nonvolatile memristive effects in phase-separated La0.5Ca0.5MnO3-based devices
Authors: Ramírez G. A. , Román Acevedo W. , Rengifo M. , Nuñez J. M. , Aguirre M. H. , Briático J. , Rubi D.
Published: February 2023

In this work, we have investigated the coexistence of volatile and nonvolatile memristive effects in epitaxial phase-separated La0.5Ca0.5MnO3 thin films. At low temperatures (50 K), we observed volatile resistive changes arising from self-heating effects in the vicinity of a metal-to-insulator transition. At higher temperatures (140 and 200 K), we measured a combination of volatile and nonvolatile effects arising from the synergy between self-heating effects and ferromagnetic-metallic phase growth induced by an external electrical field. The results reported here add phase separated manganites to the list of materials that can electrically mimic, on the same device, the behavior of both neurons and synapses, a feature that might be useful for the development of neuromorphic computing hardware.
An operative framework to model mucus clearance in silico by coupling cilia motion with the liquid environment
Authors: Laborie Emeline , Melchionna Simone , Sterpone Fabio
Published: February 2023

Mucociliary clearance is the first defense mechanism of the respiratory tract against inhaled particles. This mechanism is based on the collective beating motion of cilia at the surface of epithelial cells. Impaired clearance, either caused by malfunctioning or absent cilia, or mucus defects, is a symptom of many respiratory diseases. Here, by exploiting the lattice Boltzmann particle dynamics technique, we develop a model to simulate the dynamics of multiciliated cells in a two-layer fluid. First, we tuned our model to reproduce the characteristic length- and time-scales of the cilia beating. We then check for the emergence of the metachronal wave as a consequence of hydrodynamic mediated correlations between beating cilia. Finally, we tune the viscosity of the top fluid layer to simulate the mucus flow upon cilia beating, and evaluate the pushing efficiency of a carpet of cilia. With this work, we build a realistic framework that can be used to explore several important physiological aspects of mucociliary clearance.
Fragmentation dynamics of tetrachloromethane molecule induced by highly charged Ar7+-ion impact
Authors: Das Nirmallya , De Sankar , Bhatt Pragya , Safvan C. P. , Majumdar Abhijit
Published: February 2023

The ion impact multiple ionization and subsequent dissociation of CCl4 is studied using a beam of Ar7+ ion having the energy of about 1 MeV in a linear time- of-flight mass spectrometer, coupled with a position-sensitive detector. The complete, as well as incomplete Coulomb explosion pathways, for CCl42+ and CCl43+ ions are identified and studied. The kinetic energy release distributions of channels, kinetic energies, and momentum distributions of fragmented ions, as well as neutrals, are also calculated. Possible modes of fragmentation pathways, i.e., concerted and/or sequential, for all the identified channels are studied using Newton diagrams, Dalitz plots, and kinetic energy distributions. The dynamical information and fragmentation pathways were analyzed with the Dalitz plot and Newton diagram for the three-body dissociation channel. The nature of the fragmentation process is further investigated with simulated Dalitz plots and Newton diagrams using the simple classical mechanical model.
Benchmarking two-photon absorption strengths of rhodopsin chromophore models with CC3 and CCSD methodologies: An assessment of popular density functional approximations
Authors: Sirimatayanant Saruti , Andruniów Tadeusz
Published: February 2023

This work presents the investigations of the impact of an increasing electron correlation in the hierarchy of coupled-cluster methods, i.e., CC2, CCSD, and CC3, on two-photon absorption (2PA) strengths for the lowest excited state of the minimal rhodopsin’s chromophore model—cis-penta-2,4-dieniminium cation (PSB3). For a larger chromophore’s model [4-cis-hepta-2,4,6-trieniminium cation (PSB4)], CC2 and CCSD calculations of 2PA strengths were performed. Additionally, 2PA strengths predicted by some popular density functional theory (DFT) functionals differing in HF exchange contribution were assessed against the reference CC3/CCSD data. For PSB3, the accuracy of 2PA strengths increases in the following order: CC2 < CCSD < CC3, with the CC2 deviation from both higher-level methods exceeding 10% at 6-31+G* basis sets and 2% at aug-cc-pVDZ basis set. However, for PSB4, this trend is reversed and CC2-based 2PA strength is larger than the corresponding CCSD value. Among the DFT functionals investigated, CAM-B3LYP and BHandHLYP provide 2PA strengths in best compliance with reference data, however, with the error approaching an order of magnitude.
Concurrent surface enhanced infrared and Raman spectroscopy with single molecule sensitivity
Authors: Anderson Mark S.
Published: February 2023

Surface enhanced infrared absorption (SEIRA) and surface enhanced Raman Spectroscopy (SERS) were simultaneously measured from the same location on plasmonically active substrates. The spectra were acquired using an optical photothermal infrared spectrometer coupled with a Raman spectrometer. The sensitivity of this approach enables exceptionally small quantities of molecules to be interrogated while providing complementary information from both infrared and Raman spectroscopy. This arrangement provides additional improvement of SEIRA through the enhancement of both the optical photothermal detector signal and the infrared absorption. The plasmonic substrates tested were silver nanospheres and a gold coated atomic force microscope tip. The concurrent acquisition of SEIRA and SERS is further demonstrated by nano-sampling material onto an atomic force microscope tip. The analytes, Buckminsterfullerene and 1,2-bis(4-pyridyl) ethylene, were analyzed individually and as mixtures. The concurrent acquisition of SERIA and SERS is a unique approach. It has general applications in trace surface analysis and for the analysis of returned planetary samples.
Tuning magnetic anisotropy in SrRuO3 thin film by Ru vacancies induced phase transition
Authors: Zhang Jian , Jiang Zhongyuan , Huang Haoliang , Shan Zheling , Wang Lenan , Wang Jianlin , Huang Qiuping , Fu Zhengping , Lu Yalin
Published: February 2023

Effective control of magnetic anisotropy, including perpendicular magnetic anisotropy (PMA) and lateral magnetic anisotropy, is important for the design of low-power and high-density spintronic devices. However, the rarity of oxide materials with PMA and stringent conditions required to control magnetic anisotropy have prevented its large-scale application. Here, we demonstrate that the magnetic anisotropy of SrRuO3 films can be specified on-demand by adjusting the content of Ru vacancies to control the structure of the films. With the increase in Ru vacancies, the structure of SrRuO3 changes from orthorhombic to tetragonal. The field angle dependence of the Hall resistance confirmed that the uniaxial magnetic easy axis of SrRuO3 thin films continuously rotates in the (100)pc crystallographic plane, which is identical to the continuous phase transition. Our results not only provide a way to continuously tune the physical properties of epitaxial oxide films by continuously changing the composition but also help to provide guidance for the on-demand design of spintronic devices.
MCL-1 promiscuity and the structural resilience of its binding partners
Authors: Heckmeier Philipp J. , Ruf Jeannette , Janković Brankica G. , Hamm Peter
Published: February 2023

The allosteric protein MCL-1 and its natural inhibitors, the BH3-only proteins PUMA, BIM, and NOXA regulate apoptosis by interacting promiscuously within an entangled binding network. Little is known about the transient processes and dynamic conformational fluctuations that are the basis for the formation and stability of the MCL-1/BH3-only complex. In this study, we designed photoswitchable versions of MCL-1/PUMA and MCL-1/NOXA, and investigated the protein response after an ultrafast photo-perturbation with transient infrared spectroscopy. We observed partial α-helical unfolding in all cases, albeit on strongly varying timescales (1.6 ns for PUMA, 9.7 ns for the previously studied BIM, and 85 ns for NOXA). These differences are interpreted as a BH3-only-specific “structural resilience” to defy the perturbation while remaining in MCL-1’s binding pocket. Thus, the presented insights could help to better understand the differences between PUMA, BIM, and NOXA, the promiscuity of MCL-1, in general, and the role of the proteins in the apoptotic network.
Sputter yields of surfaces with nanoscale textures: Analytical results and Monte Carlo simulations
Authors: Bradley R. Mark , Hobler Gerhard
Published: February 2023

We find the spatially averaged sputter yield Y¯ analytically for non-planar surfaces that have slowly varying surface heights h=h(x,y). To begin, nonlocal effects like redeposition of sputtered material and secondary sputtering are neglected. We show that the leading order corrections to Y¯ are proportional to the spatial averages of (∂h/∂x)2 and (∂h/∂y)2. The constants of proportionality can be written in terms of the first and second derivatives of the sputter yield of a flat surface with respect to the ion incidence angle θ. For a range of θ values, Y¯ is a decreasing function of the amplitude of the surface texture. We also determine how the contribution of redeposition to Y¯ depends on the amplitude and characteristic lateral length scale of the surface morphology. As a test of our theory and to quantify the roles of redeposition and secondary sputtering, we performed Monte Carlo simulations of sputtering from Si targets with sinusoidal surfaces by 1 keV Ar+ ions. The theory agrees remarkably well with our Monte Carlo simulations. Our simulations also lead to the notable result that atoms that are sputtered and then strike the surface can themselves cause significant sputtering.
Outstanding improvement in removing the delocalization error by global natural orbital functional
Authors: Huan Lew-Yee Juan Felipe , Piris Mario , del Campo Jorge M.
Published: February 2023

This work assesses the performance of the recently proposed global natural orbital functional (GNOF) against the charge delocalization error. GNOF provides a good balance between static and dynamic electronic correlations leading to accurate total energies while preserving spin, even for systems with a highly multi-configurational character. Several analyses were applied to the functional, namely, (i) how the charge is distributed in super-systems of two fragments, (ii) the stability of ionization potentials while increasing the system size, and (iii) potential energy curves of a neutral and charged diatomic system. GNOF was found to practically eliminate the charge delocalization error in many of the studied systems or greatly improve the results obtained previously with PNOF7.
On the self-consistency of DFT-1/2
Authors: Cui Hanli , Yang Shengxin , Xue Kan-Hao , Huang Jinhai , Miao Xiangshui
Published: February 2023

Density functional theory (DFT)-1/2 is an efficient bandgap rectification method for DFT under local density approximation (LDA) or generalized gradient approximation. It was suggested that non-self-consistent DFT-1/2 should be used for highly ionic insulators like LiF, whereas self-consistent DFT-1/2 should still be used for other compounds. Nevertheless, there is no quantitative criterion prescribed for which implementation should work for an arbitrary insulator, which leads to severe ambiguity in this method. In this work, we analyze the impact of self-consistency in DFT-1/2 and shell DFT-1/2 calculations in insulators or semiconductors with ionic bonds, covalent bonds, and intermediate cases and show that self-consistency is required even for highly ionic insulators for globally better electronic structure details. The self-energy correction renders electrons more localized around the anions in self-consistent LDA-1/2. The well-known delocalization error of LDA is rectified, but with strong overcorrection, due to the presence of additional self-energy potential. However, in non-self-consistent LDA-1/2 calculations, the electron wave functions indicate that such localization is much more severe and beyond a reasonable range because the strong Coulomb repulsion is not counted in the Hamiltonian. Another common drawback of non-self-consistent LDA-1/2 is that the ionicity of the bonding gets substantially enhanced, and the bandgap can be enormously high in mixed ionic-covalent compounds like TiO2.
The effects of experimentally obtained electron correlation and polarization on electron densities and exchange-correlation potentials
Authors: Hupf Emanuel , Kleemiss Florian , Borrmann Tobias , Pal Rumpa , Krzeszczakowska Joanna M. , Woińska Magdalena , Jayatilaka Dylan , Genoni Alessandro , Grabowsky Simon
Published: February 2023

In X-ray constrained wavefunction (XCW) fitting, external information, such as electron correlation and polarization, is included into a single-determinantal isolated-molecule wavefunction. In a first step, we show that the extraction of these two physical effects by XCW fitting is complete and accurate by comparing to theoretical reference calculations. In a second step, we show that fitting to data from single-crystal x-ray diffraction measurements provides the same results qualitatively and how the physical effects can be separated, although always inherently convolved in the experiment. We further demonstrate that exchange–correlation potentials are systematically affected by XCW fitting in a physically meaningful way, which could be exploited for method development in quantum chemistry, subject to some remaining challenges that we also outline.
Pseudopotential analysis on hyperfine splitting frequency shift of alkali-metal atoms in noble gases, revisited
Authors: Ishikawa Kiyoshi
Published: February 2023

Theoretical pseudopotentials and dispersion potentials are used to study ground-state hyperfine splitting frequencies of alkali-metal atoms (Li, Na, K, Rb, and Cs) in noble gases (He, Ne, Ar, Kr, and Xe) in all combinations. With a single fitting parameter, calculations based on first-order perturbation theory qualitatively present each temperature dependence of the measured frequency shift. With this parameter and excitation energies of alkali-metal and noble-gas atoms, the hyperfine splitting frequency of alkali-metal atoms is suitable for investigating the properties of noble-gas atoms, such as the s-wave scattering length of electrons, the electric-dipole polarizability, and the van der Waals radius. This study suggests the possibility of improving excitation energies and van der Waals potentials of colliding pairs.
Kinetics of formic acid dehydration on Pt electrodes by time-resolved ATR-SEIRAS
Authors: Pérez-Martínez Laura , Herrero Enrique , Cuesta Angel
Published: February 2023

The potential dependence of the rate of dehydration of formic acid to adsorbed CO (COad) on Pt at pH 1 has been studied on a polycrystalline Pt surface by time-resolved surface-enhanced infrared absorption spectroscopy in the attenuated total reflection mode (ATR-SEIRAS) with simultaneous recording of current transients after a potential step. A range of formic acid concentrations has been used to obtain a deeper insight into the mechanism of the reaction. The experiments have allowed us to confirm that the potential dependence of the rate of dehydration has a bell shape, going through a maximum around the potential of zero total charge (pztc) of the most active site. The analysis of the integrated intensity and frequency of the bands corresponding to COL and COB/M shows a progressive population of the active sites on the surface. The observed potential dependence of the rate of formation of COad is consistent with a mechanism in which the reversible electroadsorption of HCOOad is followed by its rate-determining reduction to COad.
Dynamics of co-current gas–liquid film flow through a slippery channel
Authors: Vellingiri Rajagopal
Published: February 2023

We consider a thin liquid film in a wide inclined channel being driven by gravity and co-current turbulent gas flow. The bottom plate with which the liquid is in contact with is taken to be slippery, and we impose the classic Navier slip condition at this substrate. Such a setting finds application in technological processes as well as nature (e.g., distillation, absorption, and cooling devices). The gas–liquid problem can be decoupled by making certain reasonable assumptions. Under these assumptions, we solve the gas problem to obtain the tangential and normal stresses acting at the wavy gas–liquid interface for arbitrary waviness. In modeling the liquid layer dynamics, we make use of the stresses computed in the gas problem as inputs to the interface boundary conditions. We develop the long-wave model and the weighted-integral boundary layer (WIBL) model to describe the thin film dynamics. We perform a linear stability of these reduced order models to scrutinize the effect of wall slip, liquid flow rate, and the gas shear on the stability of the flat film solution. It is found that the wall slip promotes the instability of the flat interface. Furthermore, we compute solitary wave solutions of the WIBL model by implementing Keller's pseudo-arc length algorithm on a periodic domain. We observe that the wave speed as well as the wave amplitude are attenuated on incrementing the liquid slip at the substrate. We corroborate these findings with the time-dependent computations of the nonlinear WIBL model.
Theory of radial oscillations in metal nanoparticles driven by optically induced electron density gradients
Authors: Salzwedel Robert , Knorr Andreas , Hoeing Dominik , Lange Holger , Selig Malte
Published: February 2023

We provide a microscopic approach to describe the onset of radial oscillation of a silver nanoparticle. Using the Heisenberg equation of motion framework, we find that the coupled ultrafast dynamics of coherently excited electron occupation and the coherent phonon amplitude initiate periodic size oscillations of the nanoparticle. Compared to the established interpretation of experiments, our results show a more direct coupling mechanism between the field intensity and coherent phonons. This interaction triggers a size oscillation via an optically induced electron density gradient occurring directly with the optical excitation. This source is more efficient than the incoherent heating process currently discussed in the literature and well-describes the early onset of the oscillations in recent experiments.
Effect of aspect ratio on the wake transition behind a thin pitching plate
Authors: De Arnab Kumar , Sarkar Sandip
Published: February 2023

We study the influence of Aspect Ratio (AR) on three-dimensional wake transition past a thin pitching plate at Reynolds number of 1000 by performing computations for the range 0.54≤AR≤16 at pitching frequencies St=0.5,1 and maximum pitching angles θmax=5°,15°. For all AR, larger θmax and St promote thrust generation. However, higher AR imparts a stabilizing influence in the wake of the drag regime. For the ranges of AR, the drag-producing wake consisting of horseshoe vortices and bridgelets-type vortex structures, whereas twin-jet type bifurcated wakes with entangled vortices are observed for thrust-generating wakes. At higher AR, the wakes show a two-dimensional signature in the drag regime, whereas a spatial wake transition is observed in the thurst regime. The spanwise wake width shows the effect of wake compression for larger St even at θmax=5°, which is also substantiated by particle tracking showing wake compression for the thrust cases up to AR≤12. The near wake oscillations are prevalent for higher AR, although the core region remains unaffected by the aiding influence of spanwise instability for larger AR. The time average streamwise velocity for both drag and thrust regimes resembles an apparent feature of the reverse von Kármán vortex street.
Prediction of glassy silica etching with hydrogen fluoride gas by kinetic Monte Carlo simulations
Authors: Park Hyunhang , Antony Andrew C. , Banerjee Joy , Smith Nicholas J. , Agnello Gabriel
Published: February 2023

Understanding the surface properties of glass during the hydrogen fluoride (HF)-based vapor etching process is essential to optimize treatment processes in semiconductor and glass industries. In this work, we investigate an etching process of fused glassy silica by HF gas with kinetic Monte Carlo (KMC) simulations. Detailed pathways of surface reactions between gas molecules and the silica surface with activation energy sets are explicitly implemented in the KMC algorithm for both dry and humid conditions. The KMC model successfully describes the etching of the silica surface with the evolution of surface morphology up to the micron regime. The simulation results show that the calculated etch rate and surface roughness are in good agreement with the experimental results, and the effect of humidity on the etch rate is also confirmed. Development of roughness is theoretically analyzed in terms of surface roughening phenomena, and it is predicted that the values of growth and roughening exponents are 0.19 and 0.33, respectively, suggesting that our model belongs to the Kardar–Parisi–Zhang universality class. Furthermore, the temporal evolution of surface chemistry, specifically surface hydroxyls and fluorine groups, is monitored. The surface density of fluorine moieties is 2.5 times higher than that of the hydroxyl groups, implying that the surface is well fluorinated during vapor etching.
Rapidly changing speciation and extinction rates can be inferred in spite of nonidentifiability
Authors: Kopperud Bjørn T. , Magee Andrew F. , Höhna Sebastian
Published: February 2023

The birth–death model is commonly used to infer speciation and extinction rates by fitting the model to phylogenetic trees with exclusively extant taxa. Recently, it was demonstrated that speciation and extinction rates are not identifiable if the rates are allowed to vary freely over time. The group of birth–death models that have the same likelihood is called a congruence class, and there is no statistical evidence to favor one model over the other. This issue has led researchers to question if and what patterns can reliably be inferred from phylogenies of only extant taxa and whether time-variable birth–death models should be fitted at all. We explore the congruence class in the context of several empirical phylogenies as well as hypothetical scenarios. For these empirical phylogenies, we assume that we inferred the true congruence class. Thus, our conclusions apply to any empirical phylogeny for which we robustly inferred the true congruence class. When we summarize shared patterns in the congruence class, we show that strong directional trends in speciation and extinction rates are shared among most models. Therefore, we conclude that the inference of strong directional trends is robust. Conversely, estimates of constant rates or gentle slopes are not robust and must be treated with caution. Interestingly, the space of valid speciation rates is narrower and more limited in contrast to extinction rates, which are less constrained. These results provide further evidence and insights that speciation rates can be estimated more reliably than extinction rates.
Self-regulation of the nuclear pore complex enables clogging-free crowded transport
Authors: Zheng Tiantian , Zilman Anton
Published: February 2023

Nuclear pore complexes (NPCs) are the main conduits for macromolecular transport into and out of the nucleus of eukaryotic cells. The central component of the NPC transport mechanism is an assembly of intrinsically disordered proteins (IDPs) that fills the NPC channel. The channel interior is further crowded by large numbers of simultaneously translocating cargo-carrying and free transport proteins. How the NPC can efficiently, rapidly, and selectively transport varied cargoes in such crowded conditions remains ill understood. Past experimental results suggest that the NPC is surprisingly resistant to clogging and that transport may even become faster and more efficient as the concentration of transport protein increases. To understand the mechanisms behind these puzzling observations, we construct a computational model of the NPC comprising only a minimal set of commonly accepted consensus features. This model qualitatively reproduces the previous experimental results and identifies self-regulating mechanisms that relieve crowding. We show that some of the crowding-alleviating mechanisms—such as preventing saturation of the bulk flux—are “robust” and rely on very general properties of crowded dynamics in confined channels, pertaining to a broad class of selective transport nanopores. By contrast, the counterintuitive ability of the NPC to leverage crowding to achieve more efficient single-molecule translocation is “fine-tuned” and relies on the particular spatial architecture of the IDP assembly in the NPC channel.
Driving and characterizing nucleation of urea and glycine polymorphs in water
Authors: Zou Ziyue , Beyerle Eric R. , Tsai Sun-Ting , Tiwary Pratyush
Published: February 2023

Crystal nucleation is relevant across the domains of fundamental and applied sciences. However, in many cases, its mechanism remains unclear due to a lack of temporal or spatial resolution. To gain insights into the molecular details of nucleation, some form of molecular dynamics simulations is typically performed; these simulations, in turn, are limited by their ability to run long enough to sample the nucleation event thoroughly. To overcome the timescale limits in typical molecular dynamics simulations in a manner free of prior human bias, here, we employ the machine learning-augmented molecular dynamics framework “reweighted autoencoded variational Bayes for enhanced sampling (RAVE).” We study two molecular systems—urea and glycine—in explicit all-atom water, due to their enrichment in polymorphic structures and common utility in commercial applications. From our simulations, we observe multiple back-and-forth nucleation events of different polymorphs from homogeneous solution; from these trajectories, we calculate the relative ranking of finite-sized polymorph crystals embedded in solution, in terms of the free-energy difference between the finite-sized crystal polymorph and the original solution state. We further observe that the obtained reaction coordinates and transitions are highly nonclassical.
Small molecules disaggregate alpha-synuclein and prevent seeding from patient brain-derived fibrils
Authors: Murray Kevin A. , Hu Carolyn J. , Pan Hope , Lu Jiahui , Abskharon Romany , Bowler Jeannette T. , Rosenberg Gregory M. , Williams Christopher K. , Elezi Gazmend , Balbirnie Melinda , Faull Kym F. , Vinters Harry V. , Seidler Paul M. , Eisenberg David S.
Published: February 2023

The amyloid aggregation of alpha-synuclein within the brain is associated with the pathogenesis of Parkinson’s disease (PD) and other related synucleinopathies, including multiple system atrophy (MSA). Alpha-synuclein aggregates are a major therapeutic target for treatment of these diseases. We identify two small molecules capable of disassembling preformed alpha-synuclein fibrils. The compounds, termed CNS-11 and CNS-11g, disaggregate recombinant alpha-synuclein fibrils in vitro, prevent the intracellular seeded aggregation of alpha-synuclein fibrils, and mitigate alpha-synuclein fibril cytotoxicity in neuronal cells. Furthermore, we demonstrate that both compounds disassemble fibrils extracted from MSA patient brains and prevent their intracellular seeding. They also reduce in vivo alpha-synuclein aggregates in
C. elegans
. Both compounds also penetrate brain tissue in mice. A molecular dynamics–based computational model suggests the compounds may exert their disaggregating effects on the N terminus of the fibril core. These compounds appear to be promising therapeutic leads for targeting alpha-synuclein for the treatment of synucleinopathies.
Enhancing the mechanical properties of coarse-grained cemented carbides by tailoring microstructure
Authors: Yu Songbai , Zhang Jianfeng , Tong Jing , Min Fanlu , Zhang Hailong , Ma Jichang , Wang Congxu , Zhao Kui
Published: February 2023

In this study, ultrafine WC@10Co powders were used for the fabrication of coarse-grained WC-10Co with almost full densification. The incorporation of WC@10Co resulted in a decreasing size of WC grain with a rounded shape, the mean free path of Co and the WC contiguity. Further, substantial Co with face-centered cubic structure dispersed uniformly in the cemented carbides with WC@10Co-contained intergranular fracture accompanied by a large number of plastic deformation tears of the Co phase at the fracture surface and crack bridges at the crack tip. Therefore, the hardness, fracture toughness and bending strength of cemented carbides with WC@10Co reached the highest levels of 1045.3 kgf m−2, 23.6 MPa·m1/2 and 2308 MPa, respectively.

HIGHLIGHTS

The ultrafine WC@10Co contracted size distribution of WC grain with a rounded shape. The uniformly dispersed Co with a high content of FCC structure was obtained. The as-obtained coarse-grained cemented carbides showed enhanced mechanical properties
Microstructure of Al–Mg–Si–La alloy under pulsed magnetic field treatment during solidification
Authors: Gong Meina , Liu Kui , Hu Wenxin , Liu Yongzhen , Ma Yonglin
Published: February 2023

The grains refinement and secondary phase modification mechanism of Al–Mg–Si–La alloy under pulsed magnetic field during solidification were studied in detail. With application of pulsed magnetic field, the microstructure of Al–Mg–Si–La alloy consists of fine and equiaxed grains. Meanwhile, the smaller size of Mg2Si homogeneously dispersed in α-Al grains, and the number of AlFeSi and LaAlSi phase obviously decreased compared with the ones without pulsed magnetic field treatment. The cluster nucleation at the liquid region during early solidification stage is dominant reason for grains refinement in Al–Mg–Si–La alloy under pulsed magnetic field. Theoretical calculation indicated that pulsed magnetic field provides maximum energy in the alloy melt at about 760°C, which decreased the critical radius and energy barrier for nucleation.
Effect of rolling deformation on microstructure and mechanical properties of Mg–Y–Nd–Al alloy
Authors: Guo Erjun , Cao Yang , Wang Lei , Zhao Sicong , Feng Yicheng , Fu Yuanke
Published: February 2023

In this paper, a low-cost and high-performance Mg–4Y–3Nd–1.5Al rolled magnesium rare earth alloy sheet was developed by a multi-pass rolling process. The effect of cumulative rolling deformation on the microstructure and mechanical properties of the alloy sheet was studied. It is found that with the increase of rolling passes, the proportion of dynamic recrystallisation grains increases, the grains are refined and the texture strength is weakened due to the combined effect of particle excitation nucleation mechanism and grain-boundary-induced nucleation mechanism. The results show that fine-grain strengthening and work hardening are the main reasons for the high strength of the alloy sheet. This experiment provides scientific guidance for developing fine-grained magnesium alloy sheets.