bluuebunny/crossref_metadata_2025 huggingface dataset:
Tuning intramolecular charge transfer and spin–orbit coupling of AIE-active type-I photosensitizers for photodynamic therapy
Authors: Singh Ravinder , Chen Deng-Gao , Wang Chun-Hsiang , Wu Chi-Chi , Hsu Chao-Hsien , Wu Chi-Hua , Lai Tai-Ying , Chou Pi-Tai , Chen Chao-Tsen
Published: July 2022

Judicious strategy to envision fine-tuning of intramolecular charge transfer (ICT) and spin-orbit coupling (SOC) features for the advances of AIE-active Type-I photosensitizers (PSs) for image-guided photodynamic therapy (PDT).
Feature‐based augmentation and classification for tabular data
Authors: Sathianarayanan Balachander , Singh Samant Yogesh Chandra , Conjeepuram Guruprasad Prahalad S. , Hariharan Varshin B. , Manickam Nirmala Devi
Published: July 2022

Generating synthetic samples for a tabular data is a strenuous task. Most of the time, the columns (features) in the dataset may not follow an ideal distribution function. The objective of the proposed algorithm, Histogram Augmentation Technique (HAT), is to generate a dataset whose distribution is similar to that of the original dataset. This augmentation is achieved based on individual columns, where separate algorithms are designed for continuous and discrete columns. Humans also use features of an object for interpretation. When humans make a judgement, they notice prominent features and characterise the perceived object. However, conventional Machine Learning classifiers are designed and trained on the basis of samples. Taking the features as the basis for classification, Feature Importance Classifier (FIC) has been attempted in this work. FIC treats every feature independent of each other, and ranks the features based on its dependence with the classified label. It has been found that the FIC has the highest accuracy and has improved the accuracy by 5.54% on average, when it's compared to other classifiers. The suggested algorithms have been experimented on five datasets and compared with two augmentation algorithms and four state‐of‐the‐art ML classification algorithms.
A novel approach to multi‐objective optimisation of the size and location of an improved hybrid flow controller
Authors: Moradi Behzad , Kargar Abbas , Derakhshandeh Sayed Yaser , Niaki Sayed Ali Nabavi
Published: July 2022

Transient stability is one of the major features of power systems operation which can be also considered an objective function in the flexible AC transmission systems (FACTS) allocation problem. This paper introduces a general multi‐level multi‐objective optimisation framework and its application on optimising the size and location of the improved hybrid flow controller (IHFC). IHFC is a new member of the FACTS family whose ability to control power flow and improve power system stability has been investigated. The optimisation problem considers economic and stability‐based objective functions simultaneously, and the allocation problem is formulated as a non‐linear programming (NLP) problem. The New England 39‐bus system has been used as a case study to demonstrate that the proposed framework can provide efficient and economically viable solutions to the allocation problem.
Dynamic data‐driven computation method for the number of waiting passengers and waiting time in the urban rail transit network
Authors: Chen Yanyan , Li Tongfei , Sun Yan , Wu Jianjun , Guo Xin , Liu Di
Published: July 2022

Excess passengers gathering on the urban rail transit platform in a short time brings huge security risks to passengers and the daily operation of urban rail transit. However, the real‐time monitoring method of passenger flows, which relies on manual methods, cannot satisfy the requirement of daily operations at the network level anymore. This study proposes a dynamic data‐driven computation and monitoring method for the number of waiting passengers on platforms to recognize the operational risk in real‐time. For waiting passengers on platforms, the waiting time duration before boarding is also calculated based on a first‐come‐first‐service basis. It can be used to provide real‐time information services to passengers and evaluate service quality. Moreover, the proposed methodology relies solely on the AFC data and the train timetable, which makes it easy to implement in the daily operation of any urban rail transit system. Finally, taking the Beijing rail transit network as a case study, the real‐time number of waiting passengers on each platform, and the time duration passengers should wait before boarding are calculated dynamically. Meanwhile, the spatio‐temporal distribution of passengers’ waiting time and waiting passengers are detailly analyzed based on the method of cluster analysis and the complex network theory.
Influence of volume and surface conductivity on the transient surface charge characteristics of DC‐GIL insulator under thermal–electric coupled fields
Authors: Li Xiaolong , Han Songling , Wang Wen , Geng Zhenxin , Lin Xin
Published: July 2022

Here, the transient surface charge distribution of a basin‐type insulator is investigated under thermal–electric coupled fields. Horizontally installed ±200 kV direct current gas‐insulated transmission lines (DC‐GIL) are employed, and a 3D geometric model is applied. An improved method is introduced in the transient simulation under coupled fields, which involves simplifying geometric model, decoupling calculation, applying weak form partial differential equation, and simplifying ion transport equation. The influence of volume and surface electric conductivity on the transient surface charge and electric field distribution is discussed. With increasing volume conductivity, the transient charge accumulation is accelerated due to the promotion of conduction through the insulator. With increasing volume conductivity, the polarity of the charge on convex surface changes from negative to positive, while it changes from positive to negative with increasing surface conductivity. This is the consequence of the transition in dominant conduction mechanism. Non‐monotonic variation of charge density is observed attributing to the variation transient field distribution. It can be concluded that the influence of volume and surface conductivity should be focused on when evaluating the insulation characteristics of DC‐GIL insulators, and the thermal gradient should be considered in dealing with the long‐term operating insulators.
Polyphased rare-element magmatism during late orogenic evolution: geochronological constraints from NW Variscan Iberia
Authors: Melleton Jérémie , Gloaguen Eric , Frei Dirk , Lima Alexandre , Vieira Romeu , Martins Tania
Published: July 2022

Rare-element granites and pegmatites represent important sources of raw materials for “clean, green and high technologies”, such as lithium and tantalum, for example. However, mechanisms of rare-element granites and pegmatite’s origin are still far from being fully understood. Several rare-element pegmatite fields and a rare-element granite are known in the Variscan realms located in Iberia (Spain and Portugal), enhancing the interest of this area for studying the formation of these extremely fractionated melts. In situ U-Pb dating by LA-SF-ICP-MS of columbite-group minerals from rare-element granites and pegmatites of the Iberian Variscan belt provides new constraints on the generation of rare-element melts. Three events have been recognized: (i) Emplacement of the Argemela rare-element granite, in the Central Iberian Zone (CIZ), with an age of 326 ± 3 Ma; (ii) Emplacement of rare-element pegmatites from the Galicia-Trás-os-Montes Zone (GTOMZ), at an average age of 310 ± 5 Ma; (iii) Emplacement of rare-element pegmatites in the CIZ and in the southern GTOMZ at about 301 ± 3 Ma. These two last events are coeval with the two peaks of ages for the late orogenic magmatism at ca. 308 Ma and 299 Ma, and all dated rare-element pegmatites clearly emplaced during the late-orogenic evolution of the Variscan belt. Contemporaneous fields of rare-element pegmatites are arranged in belts following those formed by similar granitoid suites. Pegmatite fields from both the GTOMZ and the CIZ reveal a southward propagation of ages of emplacement, which matches the observed propagation of deformation, metamorphism and magmatism in the two different geotectonic zones. Existence of three successive rare-element events in the Iberian Massif argues against the involvement of lower crustal HP-HT metamorphism in the generation of rare-element melts. Possible sources of rare-element-enriched melts are more likely located in the middle to upper crust, as are the major components of granitic magmatism. Analyses of U and Pb isotopes from columbite-group minerals are very robust and reproducible, making them good candidates for dating ore deposits related to peraluminous magmatism as well as REE- and Nb-bearing deposits.
L’évolution à petite échelle
Authors: Gibert Jean-Michel
Published: July 2022

L’évolution à petite échelle ou microévolution concerne l’évolution au niveau intra-spécifique ou entre espèces proches. Au niveau intra-spécifique, elle permet d’analyser les forces évolutives en action : mutation, dérive génétique, migration et sélection. De plus, en raison de ce temps évolutif court, il est plus facile d’identifier les bases génétiques des différences phénotypiques observées. La plupart des études porte sur des populations actuelles mais de plus en plus de travaux analysent l’ADN ancien. Ces derniers apportent non seulement des informations importantes pour retracer l’histoire des populations mais permettent également de reconstituer les phénotypes d’individus disparus depuis plusieurs milliers d’années. Dans cette courte revue, je présente des travaux montrant comment se mettent en place des barrières pré-zygotiques ou post-zygotiques impliquées dans la formation d’espèces, avec l’exemple de la barrière géographique due à la formation de l’isthme de Panama et celui de la divergence de l’hétérochromatine chez les drosophilidés. Par ailleurs, à propos de cas bien établis, je décris les différentes approches qui ont été utilisées pour identifier les bases génétiques de variations phénotypiques : approche gène-candidat pour ce qui concerne le mélanisme chez les félins, cartographie QTL (Quantitative trait loci) pour la variation du nombre de plaques osseuses latérales chez les épinoches, étude d’association pour la pigmentation chez la coccinelle asiatique. Enfin, j’illustre le rôle de la sélection naturelle avec l’exemple iconique de l’évolution du bec des pinsons des Galapagos et l’implication de certains gènes du développement dans sa diversification morphologique.
Gemeinsam statt einsam
Authors: Gollnast Franziska
Published: July 2022

Ein verlässlicher Ansprechpartner gibt psychisch erkrankten Menschen während ihres stationären Aufenthalts Sicherheit und Halt – vor allem, wenn sie Jahre oder gar Jahrzehnte unfreiwillig in einer forensischen Klinik verbringen müssen. Die Bezugspflegekraft ist für die Betroffenen da, wenn Frust und Einsamkeit ihren Alltag bestimmen und unterstützt sie auf ihrem Recovery-Weg in ein straffreies Leben.
Authentisch und präsent
Authors: Franke-Luderer Daniela
Published: July 2022

Mut und Reflexionsfähigkeit sind wichtige Grundpfeiler, um als Genesungsbegleitender tätig zu sein. Wie die Ausbildung abläuft, ob die Inklusion ins Team gelingt und welche Rolle Authentizität, Sinnstiftung und Wertschätzung bei der Arbeit spielen, erzählen ein Stationsleiter und zwei Genesungsbegleitende des Pfalzklinikums in Klingenmünster.
Der Return-to-Prozess für die obere Extremität
– ein systematisches Review
Authors: Bäumler Hannah , Griefahn Annika , Zalpour Christoff
Published: July 2022

Einleitung Verletzungen im Sport sind in jeder Altersklasse unvermeidbar.
Häufig unterscheiden sich durchgeführte Rehabilitationsmethoden
weitreichend und der Zeitpunkt der Bereitschaft für eine
Rückkehr in den Sport kann nicht eindeutig bestimmt werden. Ein
funktionsbasiertes Rehabilitationsmodell in Form des Return-to-Prozesses
könnte den Wiedereinstieg in den Sport, anhand von Testbatterien,
strukturierter gestalten und Aussagen über die
Funktionsfähigkeit der betroffenen Struktur ermöglichen. Bisher
erfolgten in diesem Themenbereich vorwiegend Untersuchungen der unteren
Extremität. Ziel dieser Studie ist es Erweiterungsmerkmale für
den Return-to-Prozess der oberen Extremität darzustellen.

Methode Die Erstellung der systematischen Übersichtsarbeit
orientierte sich an den PRISMA-Guidelines. Für die Literaturrecherche
wurden die Datenbanken Pubmed, Cochrane Library und Web of Science nach
relevanten Studien durchsucht. Anhand der Studienergebnisse wurden die
angewandten Testverfahren zusammengetragen und miteinander verglichen.

Ergebnisse Den Einschlusskriterien entsprachen eine Kohortenstudie, 6
Fallstudien und 7 Expertenmeinungen. Zum aktuellen Zeitpunkt gibt es keine
einheitliche Definition für die Anwendung des Return-to-Prozesses. Der
Begriff Return-to wird häufig auch unabhängig von
Rehabilitationsmaßnahmen verwendet, um den Wiedereinstieg in den Sport
zu beschreiben. Die Organisation innerhalb des Return-to-Prozesses unterscheiden
sich zwischen den Autoren deutlich. Auch die angewandten Testverfahren wiesen
kaum Überschneidungen auf. Die Bereitschaft für die
Rückkehr in den Sport ist nicht einheitlich definiert und wird sowohl
mit Hilfe von Funktionstests als auch Krafttests dargestellt. Für einen
erfolgreichen Return-to-Prozess werden transparente und athletenzentrierte
Entscheidungen im interdisziplinären Team, die Integration des
biopsychosozialen Ansatzes und eine nachhaltige Steuerung der Belastung
empfohlen.

Schlussfolgerung Der funktionsbasierte Rehabilitationsansatz des
Return-to-Prozesses für die obere Extremität benötigt
einer einheitlichen Begriffsdefinition, sowie einer festgelegten Testbatterie,
deren Gütekriterien wissenschaftlich nachgewiesen wurden. Der
Return-to-Prozess muss funktions- und kraftbasierten Testverfahren beinhalten
und ergänzende Komponenten, wie akute und chronische
Belastungsverhältnisse einschließen.
The Effects of Minimalist Shoes on Plantar Intrinsic Foot Muscle Size
and Strength: A Systematic Review
Authors: Xu Jennifer , Saliba Susan A , Jaffri Abbis H
Published: July 2022

Minimalist shoes are proposed to prevent injury and enhance performance by
strengthening intrinsic foot muscles, yet there is little consensus on the
effectiveness of minimalist shoes in increasing muscle strength or size. This
systematic review assesses using minimalist shoes as an intervention on changes
in plantar intrinsic foot muscle size and strength. PubMed, CINHAL, Scopus, and
SPORT Discus were systematically searched for articles from January 2000 to
March 2022. Studies were included if they had an intervention of at least 2
weeks with a control group and examined the effect of minimalist shoes on
plantar intrinsic foot strength or size (either volume, cross-sectional area, or
thickness). Nine studies were included. There were significant increases and
percent changes in foot muscle strength, volume, cross-sectional area, and
thickness. Strength increased between 9–57%, and size increased
between 7.05–10.6%. Minimalist shoes may effectively increase
intrinsic foot muscle size and strength in healthy individuals, and they may
also be more convenient than implementing time-intensive physical therapy
programs. Future research is needed to explore using minimalist shoes as an
intervention in clinical populations who would benefit from increased IFM
strength and function. It will also be vital to improve upon IFM assessment
methods.
Postoperative Quality of Life in Patients with Pyogenic Spondylodiscitis
Authors: Abboud Tammam , Krolikowska-Fluori Magdalena , Melich Patrick , Rohde Veit , Schatlo Bawarjan
Published: July 2022

Background Pyogenic spondylodiskitis affects a fragile patient population frequently fraught with severe comorbidities. Data on long-term outcomes, especially for patients undergoing surgery, are scarce. The aim of this study was to assess the long-term quality of life after surgical instrumentation.

Methods Data of 218 patients who were treated for spondylodiskitis at our institution between January 2008 and July 2017 were reviewed. In-hospital death and mortality rates at 1 year and follow-up were assessed. A survey was conducted using the following questionnaires: Oswestry Disability Index (ODI), Short Form Work Ability Index (SF-WAI), 36-Item Short Form Health Survey (SF-36), and Short Form McGill Pain Questionnaire (SF-MPQ). We investigated the correlation between the assessed variables and clinical data including patient age, comorbidity score at admission, number of operated levels, corpectomy, and length of hospital stay.

Results In-hospital mortality rate was 1.8% and 1-year mortality rate was 5.5%. At the final follow-up (mean 7 ± 6 years), the mortality rate was 45.4%. Seventy-four patients were lost to follow-up or refused to participate in the study. Forty-four patients responded to the survey and had a mean age of 73 years and mean follow-up of 7 ± 2 years. In the ODI questionnaire, disability grades were classified as minimal (23%), moderate (21%), severe (19%), complete (33%), and bed bound (4%). We found a significant correlation between inability to return to work and severe disability on ODI (p < 0.001), as well as a low score on any component of the SF-36 (p < 0.05).

Conclusion Despite low in-hospital and 1-year mortality rates, patients with surgically treated pyogenic spondylodiskitis are prone to long-term limitation in all domains of quality of life, especially in physical health and work ability.
The rise of ‘smart’ solutions in Africa: a review of the socio-environmental cost of the transportation and employment benefits of ride-hailing technology in Ghana
Authors: Boateng Festival Godwin , Appau Samuelson , Baako Kingsley Tetteh
Published: July 2022

Governments in Africa are licensing major global ride-hailing firms to launch operations in the continent. This is often presented as a refreshing development for the continent to leverage technology to address its twin problems of inefficient urban transport and rising youth unemployment. Interviews with ride-hailing adopters (drivers, riders, and car owners) and researchers in Ghana suggest, however, that whereas the technology is driving up the standards of road transport experience, the benefits are accessible to a select few (largely, the younger, highly educated and relatively high income-earning class). The lopsided power relations underlying the ride-hailing industry have also meant that the economic opportunities it avails disproportionately benefit a few powerful players (e.g. ride-hailing firms and car owners) while stimulating‘turf wars’among online and traditional taxi drivers; deepening existing gender inequalities in access to income-earning opportunities in the commercial passenger transport sector; encouraging unhealthy driving practices, shifts from shared public transport, and inundation of the roads with more private cars. While it will be imprecise to say that the private gains of ride-hailing outstrip the public costs and, therefore, the technology is detrimental to Ghana’s development, the considered evidence raises the need for sustained scrutiny of the hailing of technological interventions as though they are the magic bullets for socio-economic transformation in Africa. Overall, the paper argues that dismantling the power structures underlying Africa’s urban challenges will require more than splashing‘smart’apps and other tech wizardries around. Indeed, the lessons from Ghana’s ride-hailing industry suggest that such exclusively technical solutions could easily take root and pattern after existing strictures of unjust power structures in ways that could exacerbate the social and environmental problems they are supposed to address.
What is wellbeing for rural South African women? Textual analysis of focus group discussion transcripts and implications for programme design and evaluation
Authors: Ferrari Giulia
Published: July 2022

Policy makers’ ultimate goal is to deliver the highest possible level of population welfare. Economists investigate the effect of socio-economic dimensions on wellbeing using unidimensional measures of life satisfaction or happiness as proxies for welfare. However, social psychologists have shown that wellbeing is a much broader construct and that an intervention may have opposite effects on its components. Unidimensional measures may hide these patterns. Most literature focuses on high-income countries. The growing evidence from low- and middle-income countries also largely relies on standard unidimensional measures. This study tests the validity of this reliance by exploring the wellbeing construct of South African women, quantitatively analysing textual data from focus group discussions to investigate whether unidimensional measures are appropriate in this context. It provides evidence against the indiscriminate use of unidimensional wellbeing measures. Cluster and correspondence analysis of the transcripts show that relevant domains of women’s wellbeing include relations with others, autonomy, and a perception of control over their environment (environmental mastery). Results also reveal that participants have a relational view of themselves, distinct from the individuated view predominant in the US and Europe and the collectivist view found in East Asia. Such relational self-perception modifies study participants’ wellbeing construct in ways that are important for policy implementation and evaluation. For example, women’s autonomy and environmental mastery rely on shared peer-identity to redefine rules and meet challenges. Wellbeing measures for policy evaluation would benefit from incorporating these insights to meaningfully measure progress towards Sustainable Development Goal 3 on ‘good health and wellbeing’ in South Africa and other contexts that exhibit similar concepts of wellbeing.
A comparable study of defect diffusion and recombination in Si and GaN
Authors: Han Xiang-Ru , Li Yang , Li Pei , Yan Xiao-Lan , Wu Xiao-Qiang , Huang Bing
Published: July 2022

Both the static and kinetic properties of defects play fundamental roles in determining the physical properties of semiconductors. Compared to the static properties of defects, a comprehensive understanding of the different defects diffusing in different types of semiconductors is still lacking. In this article, based on extensive first-principles calculations, we have done a comparative study on the diffusion mechanisms of point defects in Si (a typical elemental semiconductor) and GaN (a typical compound semiconductor). The significantly different diffusion mechanisms of vacancies and interstitials in Si and GaN result in significantly different recombination mechanisms, i.e., a novel synergistic effect to accelerate the annihilation of defects is observed in Si but not in GaN, indicating that an efficient self-recovery mechanism can exist in Si but not in GaN. Our results not only explain some experimental observations in Si and GaN under nonequilibrium irradiation conditions but also provide a good example to understand the different kinetic properties of defects in elemental and compound semiconductors.
Going beyond the electric-dipole approximation in the calculation of absorption and (magnetic) circular dichroism spectra including scalar relativistic and spin–orbit coupling effects
Authors: Foglia Nicolás O. , Maganas Dimitrios , Neese Frank
Published: July 2022

In this work, a time-dependent density functional theory (TD-DFT) scheme for computing optical spectroscopic properties in the framework of linearly and circularly polarized light is presented. The scheme is based on a previously formulated theory for predicting optical absorption and magnetic circular dichroism (MCD) spectra. The scheme operates in the framework of the full semi-classical field–matter interaction operator, thus generating a powerful and general computational scheme capable of computing the absorption, circular dichroism (CD), and MCD spectra. In addition, our implementation includes the treatment of relativistic effects in the framework of quasidegenerate perturbation theory, which accounts for scalar relativistic effects (in the self-consistent field step) and spin–orbit coupling (in the TD-DFT step), as well as external magnetic field perturbations. Hence, this formalism is also able to probe spin-forbidden transitions. The random orientations of molecules are taken into account by a semi-numerical approach involving a Lebedev numerical quadrature alongside analytical integration. It is demonstrated that the numerical quadrature requires as few as 14 points for satisfactory converged results, thus leading to a highly efficient scheme, while the calculation of the exact transition moments creates no computational bottlenecks. It is demonstrated that at zero magnetic field, the CD spectrum is recovered, while the sum of left and right circularly polarized light contributions provides the linear absorption spectrum. The virtues of this efficient and general protocol are demonstrated on a selected set of organic molecules where the various contributions to the spectral intensities have been analyzed in detail.
Bessel beam induced deep-penetrating bioimaging and self-monitored heating using Nd/Yb heavily doped nanocrystals
Authors: Ning Danyang , Xu Li , Zhu Yin , Li Dongyu , Jiang Haili , Carvajal Joan Josep , Li Hanyang , Ren Jing , Liu Lu , Zhang Jianzhong
Published: July 2022

Biological probes facilitate optical imaging and disease diagnosis and treatment. However, the large absorption and scattering loss in the tissue highly limit the depth during the application. In the present research, an NIR-I bioprobing system, which utilizes the Bessel beam to excite heavily doping nanocrystals, has been developed for deep tissue applications. On the one hand, the capillary mode selection method generates the Bessel excitation beam, lowering the excitation energy loss. On the other hand, a strong energy harvest of NaYbF4:90%Nd nanocrystals enables effective fluorescence and heat generation upon 800 nm excitation. By considering the advantages of Bessel excitation and heavily doping nanocrystals, up to ∼3 cm penetration depth for ex vivo bioimaging and the potential self-monitored photothermal treatment are demonstrated. The resultant bioprobing system allows deep tissue imaging and photothermal therapy, showcasing broad prospects in medical research and clinical applications.
Understanding and controlling capsule symmetry in near vacuum hohlraums at the National Ignition Facility
Authors: Higginson Drew P. , Strozzi D. J. , Bailey D. , MacLaren S. A. , Meezan N. B. , Wilks S. C. , Zimmerman G.
Published: July 2022

The near vacuum hohlraum platform is an inertial confinement fusion design at the National Ignition Facility (NIF) that uses the lowest practical density of helium gas of 30 μg/cc to fill the hohlraum, which is ten times lower than now used routinely. This has several advantages, such as high laser coupling; however, the inability to understand and simulate the symmetry of the imploded capsule has limited the use of this platform. This work presents the first simulations that are able to accurately capture the highly prolate implosion seen experimentally without unphysical, ad hoc model changes. While previous investigations attributed this asymmetry to multi-species interpenetration in the hohlraum, we find that this alone has little effect on symmetry. Instead, it is the presence of crossed-beam energy transfer (CBET), occurring with no applied wavelength shift between the laser beams, that increases the laser power to the inner cones and causes a more prolate implosion. The effect of CBET is increased in the simulation model when the hohlraum laser entrance hole hardware is included. Using this understanding, CBET is exploited by shifting the inner-beam wavelength by −0.75 Å (at 1ω) with respect to the outer-beams. This transfers laser power to the outer-beams in contrast to positive wavelength shifts as done routinely on NIF and produces a round capsule implosion in our simulations. This work shows the possibility of the near vacuum hohlraum as a viable experimental platform.
Electronic structure of silver chalcogenides investigated by hard x-ray photoemission spectroscopy and density functional theory calculations
Authors: Sato K. , Hirata K. , Singh S. , Kuga K. , Ogawa F. , Matsunami M. , Takeuchi T.
Published: July 2022

We have investigated the electronic structure of silver chalcogenides Ag2X (X = S, Se, Te) and their solid solutions using hard x-ray photoemission spectroscopy in combination with density functional theory calculations using generalized gradient approximation (GGA). By including the corrections for on-site Coulomb interactions (GGA + U), we successfully reproduced the valence band photoemission spectra, which consist mainly of the Ag 4d band, by calculation. The estimated values for U = 4–6 eV are slightly high for Ag 4d electrons but are consistent with those used in previously reported structural studies. On the other hand, the magnitude of the energy gap is virtually independent of U. These results suggest the strong correlation between Ag 4d electrons in Ag2X compounds to have surprisingly little impact on their electron transport properties.
Ammonia: The molecule for establishing 14N and 15N absolute shielding scales and a source of information on nuclear magnetic moments
Authors: Makulski Włodzimierz , Aucar Juan J. , Aucar Gustavo A.
Published: July 2022

Multinuclear Nuclear Magnetic Resonance (NMR) studies of the gaseous mixtures 3He/14NH3 and 3He/15NH3 are reported. Precise analysis of the 3He, 14N, 15N, and 1H resonance frequencies show a linear dependence on the gas density. Extrapolation of these results to the zero-pressure limit gives ν0(1H), ν0(14N), and ν0(15N) resonance frequencies of the isolated ammonia molecule at 300 K. The analogous value for 3He atoms in gaseous mixtures ν0(3He) was measured as well. The application of a new scheme to introduce the most important electronic effects on NMR shieldings, together with highly accurate quantum chemical shielding calculations, allows the 14/15N and 1H shielding of the isolated ammonia molecule to be obtained with the greatest accuracy and precision. For the first time, these studies were carried out on ammonia within the so-called four-component relativistic framework. The NMR frequency comparison method provides an approach for determining the 14N and 15N nuclear magnetic moments. The new shielding parameters in ammonia were used for re-evaluation of the entire nitrogen absolute shielding scale. Additionally, the absolute shielding values of several gaseous compounds and secondary reference substances in liquids were presented. It was established that 14N and 15N absolute shielding constants in 14NH3 and 15NH3 are very similar and only differ by less than 0.01 ppm, which is not usually measurable in NMR experiments. Precise calculations of 14N and 15N dipole moments were also made from these accurate shielding values.
Modeling the temporal evolution and stability of thin evaporating films for wafer surface processing
Authors: Huber Max , Hu Xiao , Zienert Andreas , Schuster Jörg , Schulz Stefan E.
Published: July 2022

The interaction of thin evaporating fluid films with solids is studied using the example of water on LiTaO3 (LTO). Adsorption energies are computed by ab initio density functional theory (DFT) and used to calculate the Gibbs free energy of adsorption of water on LTO. Integrating the disjoining pressure, consisting of molecular and structural components, with respect to film thickness gives an expression for the Gibbs free energy. In this way, parameters for the disjoining pressure can be calculated by fitting its integral to the Gibbs free energy computed by ab initio DFT. A combination of literature-known models for spin drying and evaporation is utilized to describe the temporal evolution of the water layer. The vapor above the water layer is modeled by diffusion and a mass balance is applied at the water–air interface. For thick initial layers, an analytical approximation is derived which only depends on fluid and ambient conditions but not on the substrate properties.
Protein folding intermediates on the dimensionality reduced landscape with UMAP and native contact likelihood
Authors: Oide Mao , Sugita Yuji
Published: July 2022

To understand protein folding mechanisms from molecular dynamics (MD) simulations, it is important to explore not only folded/unfolded states but also representative intermediate structures on the conformational landscape. Here, we propose a novel approach to construct the landscape using the uniform manifold approximation and projection (UMAP) method, which reduces the dimensionality without losing data-point proximity. In the approach, native contact likelihood is used as feature variables rather than the conventional Cartesian coordinates or dihedral angles of protein structures. We tested the performance of UMAP for coarse-grained MD simulation trajectories of B1 domain in protein G and observed on-pathway transient structures and other metastable states on the UMAP conformational landscape. In contrast, these structures were not clearly distinguished on the dimensionality reduced landscape using principal component analysis or time-lagged independent component analysis. This approach is also useful to obtain dynamical information through Markov state modeling and would be applicable to large-scale conformational changes in many other biomacromolecules.
ELECTRODE: An electrochemistry package for atomistic simulations
Authors: Ahrens-Iwers Ludwig J. V. , Janssen Mathijs , Tee Shern R. , Meißner Robert H.
Published: July 2022

Constant potential methods (CPMs) enable computationally efficient simulations of the solid–liquid interface at conducting electrodes in molecular dynamics. They have been successfully used, for example, to realistically model the behavior of ionic liquids or water-in-salt electrolytes in supercapacitors and batteries. CPMs model conductive electrodes by updating charges of individual electrode atoms according to the applied electric potential and the (time-dependent) local electrolyte structure. Here, we present a feature-rich CPM implementation, called ELECTRODE, for the Large-scale Atomic/Molecular Massively Parallel Simulator, which includes a constrained charge method and a thermo-potentiostat. The ELECTRODE package also contains a finite-field approach, multiple corrections for nonperiodic boundary conditions of the particle–particle particle–mesh solver, and a Thomas–Fermi model for using nonideal metals as electrodes. We demonstrate the capabilities of this implementation for a parallel-plate electrical double-layer capacitor, for which we have investigated the charging times with the different implemented methods and found an interesting relationship between water and ionic dipole relaxations. To prove the validity of the one-dimensional correction for the long-range electrostatics, we estimated the vacuum capacitance of two coaxial carbon nanotubes and compared it to structureless cylinders, for which an analytical expression exists. In summary, the ELECTRODE package enables efficient electrochemical simulations using state-of-the-art methods, allowing one to simulate even heterogeneous electrodes. Moreover, it allows unveiling more rigorously how electrode curvature affects the capacitance with the one-dimensional correction.
Correlative study between the local atomic and electronic structures of amorphous carbon materials via 4D-STEM and STEM-EELS
Authors: Ryu Jinseok , Lee Sangmin , Kim Sungtae , Joo Young-Chang , Kim Miyoung
Published: July 2022

Amorphous materials have been used in a range of electronic and photonic applications, and the need for quantitative analytical techniques on their local structural information is growing. We present a comprehensive analysis of the atomic and electronic structures of an amorphous material, amorphous carbon (a-C), with scanning transmission electron microscopy (STEM)-derived techniques, four-dimensional STEM (4D-STEM), and STEM-electron energy loss spectroscopy (STEM-EELS). Each diffraction pattern of an a-C layer stack acquired via 4D-STEM is transformed into a reduced density function (RDF) and a radial variance profile (RVP) to retrieve the information on the atomic structures. Importantly, a machine-learning approach (preferably cluster analysis) separates distinct features in the EELS and RDF datasets; it also describes the spatial distributions of these features in the scanned regions. Consequently, we showed that the differences in the sp2/sp3 ratio and the involvement of additional elements led to changes in the bond length. Furthermore, we identified the dominant types of medium-range ordering structures (diamond-like or graphite-like nano-crystals) by correlations among the EELS, RDF, and RVP data. The information obtained via STEM-EELS and 4D-STEM can be strongly correlated, leading to the comprehensive characterization of the a-C layer stack for a nanometer-scale area. This process can be used to investigate any amorphous material, thereby yielding comprehensive information regarding the origins of notable properties.
Electron attachment to fluorodeoxyglucose: Dissociation dynamics in a molecule of near-zero electron affinity
Authors: Arthur-Baidoo Eugene , Ončák Milan , Denifl Stephan
Published: July 2022

Fluorodeoxyglucose (FDG) is a glucose derivative with fluorine at the C2 position. The molecule containing the radioactive F-18 isotope is well known from its application in positron emission tomography as a radiotracer in tumor examination. In the stable form with the F-19 isotope, FDG was proposed as a potential radiosensitizer. Since reduction processes may be relevant in radiosensitization, we investigated low-energy electron attachment to FDG with a crossed electron–molecule beam experiment and with quantum chemical calculations as well as molecular dynamics at elevated temperatures to reveal statistical dissociation. We experimentally find that the susceptibility of FDG to low-energy electrons is relatively low. The calculations indicate that upon attachment of an electron with a kinetic energy of ∼0 eV, only dipole-bound states are accessible, which agrees with the weak ion yields observed in the experiment. The temporary negative ions formed upon electron attachment to FDG may decay by a large variety of dissociation reactions. The major fragmentation channels include H2O, HF, and H2 dissociation, accompanied by ring opening.
Spin–orbit transitions in the N+(PJA3)+H2→ NH+(X2Π,4Σ−) + H(2S) reaction, using adiabatic and mixed quantum-adiabatic statistical approaches
Authors: Gómez-Carrasco Susana , Félix-González Daniel , Aguado Alfredo , Roncero Octavio
Published: July 2022

The cross section and rate constants for the title reaction are calculated for all the spin–orbit states of N+(PJA3) using two statistical approaches, one purely adiabatic and the other one mixing quantum capture for the entrance channel and adiabatic treatment for the products channel. This is made by using a symmetry adapted basis set combining electronic (spin and orbital) and nuclear angular momenta in the reactants channel. To this aim, accurate ab initio calculations are performed separately for reactants and products. In the reactants channel, the three lowest electronic states (without spin–orbit couplings) have been diabatized, and the spin–orbit couplings have been introduced through a model localizing the spin–orbit interactions in the N+ atom, which yields accurate results as compared to ab initio calculations, including spin–orbit couplings. For the products, 11 purely adiabatic spin–orbit states have been determined with ab initio calculations. The reactive rate constants thus obtained are in very good agreement with the available experimental data for several ortho-H2 fractions, assuming a thermal initial distribution of spin–orbit states. The rate constants for selected spin–orbit JA states are obtained, to provide a proper validation of the spin–orbit effects to obtain the experimental rate constants.
Effects of flow intensity on local scour around a submerged square pile in a steady current
Authors: Du Shengtao , Wang Zhenlu , Wang Risheng , Liang Bingchen , Pan Xinying
Published: July 2022

Local scour around submerged square piles is very common in offshore and coastal engineering and can result in pile failure. In the study reported here, because the flow intensity (the ratio of the depth-averaged velocity to the threshold velocity for sediment particle motion) is one of the most important factors affecting the maximum scour depth in local scour, its effects on local scour around a submerged square pile were studied under clear-water scour conditions. A series of experimental tests with flow intensity in the range of 0.39–1.04 was conducted in steady current, and the flow intensity was classified as weak, transitional, or high according to the pattern of the scour hole upstream of the pile and the sand dunes downstream. The characteristics of sediment scour and deposition for temporal sediment bed elevation along a pile side and the temporal maximum scour depth were found to vary greatly among the three flow intensity conditions. An exponential function, which fitted the experimental data well, was used to fit how the maximum scour depth evolved, and the coefficients of timescale and scour depth proportion in the initial and development scouring stages were obtained at different values of the flow intensity.
Full-dimensional automated potential energy surface development and dynamics for the OH + C2H6 reaction
Authors: Gruber Balázs , Tajti Viktor , Czakó Gábor
Published: July 2022

We develop a full-dimensional analytical potential energy surface (PES) for the OH + C2H6 reaction using the Robosurfer program system, which automatically (1) selects geometries from quasi-classical trajectories, (2) performs ab initio computations using a coupled-cluster singles, doubles, and perturbative triples-F12/triple-zeta-quality composite method, (3) fits the energies utilizing the permutationally invariant monomial symmetrization approach, and (4) iteratively improves the PES via steps (1)–(3). Quasi-classical trajectory simulations on the new PES reveal that hydrogen abstraction leading to H2O + C2H5 dominates in the collision energy range of 10–50 kcal/mol. The abstraction cross sections increase and the dominant mechanism shifts from rebound (small impact parameters and backward scattering) to stripping (larger impact parameters and forward scattering) with increasing collision energy as opacity functions and scattering angle distributions indicate. The abstraction reaction clearly favors side-on OH attack over O-side and the least-preferred H-side approach, whereas C2H6 behaves like a spherical object with only slight C–C-perpendicular side-on preference. The collision energy efficiently flows into the relative translation of the products, whereas product internal energy distributions show only little collision energy dependence. H2O/C2H5 vibrational distributions slightly/significantly violate zero-point energy and are nearly independent of collision energy, whereas the rotational distributions clearly blue-shift as the collision energy increases.
Efficient simulation of resonance Raman spectra with tight-binding approximations to density functional theory
Authors: Ashtari-Jafari Sahar , Jamshidi Zahra , Visscher Lucas
Published: July 2022

Resonance Raman spectroscopy has long been established as one of the most sensitive techniques for detection, structure characterization, and probing the excited-state dynamics of biochemical systems. However, the analysis of resonance Raman spectra is much facilitated when measurements are accompanied by Density Functional Theory (DFT) calculations that are expensive for large biomolecules. In this work, resonance Raman spectra are therefore computed with the Density Functional Tight-Binding (DFTB) method in the time-dependent excited-state gradient approximation. To test the accuracy of the tight-binding approximations, this method is first applied to typical resonance Raman benchmark molecules, such as β-carotene, and compared to results obtained with pure and range-separated exchange–correlation functionals. We then demonstrate the efficiency of the approach by considering a computationally challenging heme variation. Overall, we find that the vibrational frequencies and excited-state properties (energies and gradients) that are needed to simulate the spectra are reasonably accurate and suitable for interpretation of experiments. We can therefore recommend DFTB as a fast computational method to interpret resonance Raman spectra.
A gut microbial peptide and molecular mimicry in the pathogenesis of type 1 diabetes
Authors: Girdhar Khyati , Huang Qian , Chow I-Ting , Vatanen Tommi , Brady Claudia , Raisingani Amol , Autissier Patrick , Atkinson Mark A. , Kwok William W. , Kahn C. Ronald , Altindis Emrah
Published: July 2022

Type 1 diabetes (T1D) is an autoimmune disease characterized by the destruction of pancreatic β-cells. One of the earliest aspects of this process is the development of autoantibodies and T cells directed at an epitope in the B-chain of insulin (insB:9–23). Analysis of microbial protein sequences with homology to the insB:9–23 sequence revealed 17 peptides showing >50% identity to insB:9–23. Of these 17 peptides, the
hprt4–18
peptide, found in the normal human gut commensal
Parabacteroides distasonis
, activated both human T cell clones from T1D patients and T cell hybridomas from nonobese diabetic (NOD) mice specific to insB:9–23. Immunization of NOD mice with
P. distasonis
insB:9–23 peptide mimic or insB:9–23 peptide verified immune cross-reactivity. Colonization of female NOD mice with
P. distasonis
accelerated the development of T1D, increasing macrophages, dendritic cells, and destructive CD8
+
T cells, while decreasing FoxP3
+
regulatory T cells. Western blot analysis identified
P. distasonis
–reacting antibodies in sera of NOD mice colonized with
P. distasonis
and human T1D patients. Furthermore, adoptive transfer of splenocytes from
P. distasonis
–treated mice to NOD/SCID mice enhanced disease phenotype in the recipients. Finally, analysis of human children gut microbiome data from a longitudinal DIABIMMUNE study revealed that seroconversion rates (i.e., the proportion of individuals developing two or more autoantibodies) were consistently higher in children whose microbiome harbored sequences capable of producing the
hprt4–18
peptide compared to individuals who did not harbor it. Taken together, these data demonstrate the potential role of a gut microbiota-derived insB:9–23-mimic peptide as a molecular trigger of T1D pathogenesis.
Anode electrolysis of sulfides
Authors: Qu Jiakang , Chen Xiang , Xie Hongwei , Gao Shuaibo , Wang Dihua , Yin Huayi
Published: July 2022

Traditional sulfide metallurgy produces harmful sulfur dioxide and is energy intensive. To this end, we develop an anode electrolysis approach in molten salt by which sulfide is electrochemically split into sulfur gas at a graphite inert anode while releasing metal ions that diffuse toward and are deposited at the cathode. The anodic splitting dictates the “sulfide-to-metal ion and sulfur gas” conversion that makes the reaction recur continuously. Using this approach, Cu
2
S is converted to sulfur gas and Cu in molten LiCl-KCl at 500 °C with a current efficiency of 99% and energy consumption of 0.420 kWh/kg
−Cu
(only considering the electricity for electrolysis). Besides Cu
2
S, the anode electrolysis can extract Cu from Cu matte that is an intermediate product from the traditional sulfide smelting process. More broadly, Fe, Ni, Pb, and Sb are extracted from FeS, CuFeS
2
, NiS, PbS, and Sb
2
S
3
, providing a general electrochemical method for sulfide metallurgy.