bluuebunny/crossref_metadata_2025 huggingface dataset:
E2F2 Promotes Wound Healing of Diabetic Foot Ulcer by Regulating
CDCA7L Transcription
Authors: Xiao Meimei , Wang Jiusong , Chen Yanming
Published: March 2023

Objective The E2F2 transcription factor can accelerate cell proliferation
and wound healing. However, its mechanism of action in a diabetic foot ulcer
(DFU) remains unclear. Therefore, this study explores the influence of E2F2 on
wound healing in DFU by examining cell division cycle-associated 7-like (CDCA7L)
expression.

Methods CDCA7L and E2F2 expression in DFU tissues were analyzed with
databases. CDCA7L and E2F2 expression were altered in human umbilical vein
endothelial cells (HUVECs) and spontaneously transformed human keratinocyte cell
culture (HaCaT) cells. Cell viability, migration, colony formation, and
angiogenesis were evaluated. Binding of E2F2 to the CDCA7L promoter was
examined. Subsequently, a diabetes mellitus (DM) mouse model was established and
treated with full-thickness excision followed by CDCA7L overexpression. Wound
healing in these mice was observed and recorded, and vascular endothelial growth
factor receptor 2 (VEGFR2) and hematopoietic progenitor cell antigen CD34 (CD34)
expression were determined. E2F2 and CDCA7L expression levels in cells and mice
were evaluated. The expression of growth factors was tested.

Results CDCA7L expression was downregulated in DFU tissues and wound
tissues from DM mice. Mechanistically, E2F2 bound to the CDCA7L promoter to
upregulate CDCA7L expression. E2F2 overexpression enhanced viability, migration,
and growth factor expression in HaCaT cells and HUVECs, and augmented HUVEC
angiogenesis and HaCaT cell proliferation, which was nullified by silencing
CDCA7L. In DM mice, CDCA7L overexpression facilitated wound healing and elevated
the expression level of growth factors.

Conclusions E2F2 facilitated cell proliferation and migration and fostered
wound healing in DFU cells through binding to the CDCA7L promoter.
Die Bauchspeicheldrüse – der Blick fürs
Ganze
Authors: Rudat Rüdiger
Published: March 2023

Eine Pathologie der Bauchspeicheldrüse ist vielfach Wegbereiter für
weitere Pathologien desselben Organs. Grund dafür ist die enge
Verknüpfung der endokrinen und exokrinen Anteile sowie die vergleichbaren
Pathogenese-Faktoren der unterschiedlichen Erkrankungen. Phytotherapeutika und
Komplexhomöopathika sind aufgrund ihrer Multi-Target-Wirkungen und der
großen therapeutischen Breite ideale Mittel, um bei Diabetes, Exokriner
Pankreas-Insuffizienz und chronischer Pankreatitis helfend einzugreifen.
Ganzheitliche Diagnose- und Therapieansätze bei Hunden mit
rezidivierender Pankreas-Problematik
Authors: Ailer Marion Nicole
Published: March 2023

Rezidivierende Pankreatitiden sind oftmals durch eine falsche
Fütterung bedingt. Dabei scheint weniger die
Fütterungsart an sich, sondern vielmehr ein
unverträglicher Umstand (zu fett, zu schwer verdaulich) der
konkrete Auslöser zu sein. Abhilfe schafft eine strikte
Diät mit nur 50 Prozent Fleischanteil und 50 Prozent gekochtem
Gemüse, zudem sorgt die Zugabe von Pankreasenzymen zur
Vorverdauung des Futters für eine Entlastung der
Bauchspeicheldrüse. Weiterhin können verschiedene
alternative Therapiemethoden unterstützend eingesetzt
werden.
Oxidation Products from the Neolignan Licarin A by Biomimetic Reactions and Assessment of in vivo Acute Toxicity
Authors: Souza Juliana Neves de Paula e , da Silva Rodrigo Moreira , Fortes Simone Silveira , de Oliveira Anderson Rodrigo Moraes , Ferreira Leandro S. , Vessecchi Ricardo , Lopes Norberto Peporine , Silva Denise Brentan
Published: March 2023

Licarin A, a dihydrobenzofuranic neolignan presents in several medicinal plants and seeds of nutmeg, exhibits strong activity against protozoans responsible for Chagas disease and
leishmaniasis. From biomimetic reactions by metalloporphyrin and Jacobsen catalysts, seven products were determined: four isomeric products yielded by epoxidation from licarin A, besides a
new product yielded by a vicinal diol, a benzylic aldehyde, and an unsaturated aldehyde in the structure of the licarin A. The incubation with rat and human liver microsomes partially
reproduced the biomimetic reactions by the production of the same epoxidized product of m/z 343 [M + H]+. In vivo acute toxicity assays of licarin A suggested liver
toxicity based on biomarker enzymatic changes. However, microscopic analysis of tissues sections did not show any tissue damage as indicative of toxicity after 14 days of exposure. New
metabolic pathways of the licarin A were identified after in vitro biomimetic oxidation reaction and in vitro metabolism by rat or human liver microsomes.
Kosten potenziell ambulant erbringbarer endoskopischer Leistungen in Fällen mit 1-Tages-Verweildauer gegenüber einer längeren Verweildauer
Authors: Rathmayer Markus , Heinlein Wolfgang , Wagner Tobias , Lerch Markus M. , Lammert Frank , Dollhopf Markus , Haag Cornelie , Gölder Stefan Karl , Kandulski Arne , Schad Moritz , Schmidt Alexandra , Gundling Felix , Wilke Michael , Albert Jörg G. ,   für die DRG-Projektgruppe der DGVS*
Published: March 2023

Einleitung Die „Ambulantisierung“, d.h. die Ausweitung ambulanter Leistungen auf Behandlungen, die bisher stationär erbracht wurden, ist ein erklärtes Ziel der Gesundheitspolitik. Unklar ist, inwieweit Kosten einer endoskopischen Prozedur und die Erkrankungsschwere von der Dauer der stationären Behandlung abhängig sind. Wir überprüften daher, ob endoskopische Leistungen bei Fällen mit einem Tag Verweildauer (VWD) vergleichbar teuer sind wie Fälle mit längerer VWD.

Methodik Aus dem DGVS-Leistungskatalog wurden ambulant erbringbare Leistungen ausgewählt. 1-Tagesfälle mit genau einer solchen gastroenterologisch-endoskopischen (GAEN-)Leistung wurden mit Fällen mit VWD>1 Tag hinsichtlich ihres Patient Clinical Complexity Level (PCCL) und ihrer mittleren Kosten verglichen. Als Datenquelle diente das DGVS-DRG-Projekt mit §21-KHEntgG-Kostendaten von 57 Krankenhäusern aus 2018 und 2019. Endoskopische Kosten wurden der Kostenstellengruppe 8 der InEK-Kostenmatrix entnommen und plausibilisiert.

Ergebnisse Insgesamt wurden 122.514 Fälle mit genau einer GAEN-Leistung identifiziert. In 30 von 47 Leistungsgruppen zeigten sich statistisch gleiche Kosten. In 10 Gruppen war der Kostenunterschied nicht relevant (<10%). Kostenunterschiede >10% bestanden bei der ÖGD mit Varizentherapie, Einlage einer selbstexpandierenden Prothese, Dilatation / Bougierung, dem Wechsel einer PTCD, der nicht aufwendigen ERCP, der Endosonografie sowie der Koloskopie mit endoskopischer Mukosaresektion, endoskopischer Vollwandresektion oder Fremdkörperentfernung. Der PCCL-Wert war in allen bis auf einen Fall unterschiedlich.

Schlussfolgerung GAEN-Leistungen, die stationär erbracht wurden und potenziell ambulant erbringbar sind, sind bei 1-Tagesfällen überwiegend gleich teuer wie bei Patienten mit einer VWD von mehr als einem Tag. Die Erkrankungsschwere ist geringer. Kalkulierte §21-KHEntgG-Kostendaten bilden damit eine belastbare Basis für die Kalkulation einer sachgerechten Vergütung von zukünftig im Rahmen des AOP ambulant zu erbringenden Leistungen im Krankenhaus.
Kinesiophobia And Related Factors In Adult Patients With Familial
Mediterranean Fever
Authors: Saka Seda , Çetinkaya İrem , Günaydın Elif İrem , Çetinkaya Ayşenur , Yavuzer Melek Güneş
Published: March 2023

Objective Kinesiophobia is a common problem in patients with rheumatic
diseases and can cause physical inactivity, social isolation, disability, and
poor quality of life. This study aimed to evaluate kinesiophobia and associated
factors in patients with familial Mediterranean fever (FMF).

Methods A total of 38 patients diagnosed with FMF volunteered to
participate in the study. All patients were assessed using the Tampa
Kinesiophobia Scale (TKS), the International Physical Activity Questionnaire
(IPAQ), the Fatigue Severity Scale (FSS), and the Hospital Anxiety and
Depression Scale (HADS).

Results Thirty-three (86.8%) of the patients had TKS scores over
37, indicating high levels of kinesiophobia. The TKS score was positively
correlated with the HADS depression score (r=0.530; p=0.001) and
the FSS score (r=0.340; p=0.035) but was not significantly
associated with age (r=0.102; p=0.543), disease duration
(r=–0.110; p=0.511), body mass index (r=0.283;
p=0.085), the HADS anxiety score (r=0.306; p=0.061), or
the IPAQ score (r=–0.097; p=0.563).

Conclusions Our sample of adult FMF patients showed high levels of
kinesiophobia associated with fatigue and depression. Treatments focusing on
kinesiophobia in FMF patients could help to increase the effectiveness of
rehabilitation.
Identifying High-Need Primary Care Patients Using Nursing Knowledge and Machine Learning Methods
Authors: Hewner Sharon , Smith Erica , Sullivan Suzanne S.
Published: March 2023

Background Patient cohorts generated by machine learning can be enhanced with clinical knowledge to increase translational value and provide a practical approach to patient segmentation based on a mix of medical, behavioral, and social factors.

Objectives This study aimed to generate a pragmatic example of how machine learning could be used to quickly and meaningfully cohort patients using unsupervised classification methods. Additionally, to demonstrate increased translational value of machine learning models through the integration of nursing knowledge.

Methods A primary care practice dataset (N = 3,438) of high-need patients defined by practice criteria was parsed to a subset population of patients with diabetes (n = 1233). Three expert nurses selected variables for k-means cluster analysis using knowledge of critical factors for care coordination. Nursing knowledge was again applied to describe the psychosocial phenotypes in four prominent clusters, aligned with social and medical care plans.

Results Four distinct clusters interpreted and mapped to psychosocial need profiles, allowing for immediate translation to clinical practice through the creation of actionable social and medical care plans. (1) A large cluster of racially diverse female, non-English speakers with low medical complexity, and history of childhood illness; (2) a large cluster of English speakers with significant comorbidities (obesity and respiratory disease); (3) a small cluster of males with substance use disorder and significant comorbidities (mental health, liver and cardiovascular disease) who frequently visit the hospital; and (4) a moderate cluster of older, racially diverse patients with renal failure.

Conclusion This manuscript provides a practical method for analysis of primary care practice data using machine learning in tandem with expert clinical knowledge.
The Role of Postoperative Dressing in Hypospadias Surgery: A Systematic Review and Meta-analysis of the Pediatric Literature
Authors: Escolino Maria , Florio Luisa , Esposito Giovanni , Esposito Ciro
Published: March 2023

This study aimed to describe the available dressings and their management in patients undergoing hypospadias repair and compare postoperative outcomes with and without dressing and between the different dressing types. A comprehensive electronic literature search of PubMed, Embase, and Cochrane Library was conducted to obtain studies, published in the period 1990 to 2021, reporting on the dressing used following hypospadias surgery. All information regarding the dressing was considered as primary endpoints, whereas surgical outcomes were assessed as secondary outcomes. Thirty-one studies containing 1,790 subjects undergoing hypospadias repair were included. Dressings were divided into three categories: nonadherent to the wound, adherent to the wound, and glue-based dressings. Most authors preferred to remove/change the dressing in the ward and the median time of removal/change was 6.56 postoperative days. The dressing removal appeared as the most frequent factor generating parental anxiety. The median rate of wound-related complications was 8.18%, of urethroplasty complications 9.08% and of reoperations 8.18%. Meta-analysis of outcomes showed higher risk of reoperations using conventional dressing, with no differences in urethroplasty and wound-related complications rates between conventional and glue-based dressings. Furthermore, the use of dressing reported increased risk of wound-related complications compared with no dressing, without significant differences regarding occurrence of urethroplasty complications and reoperations. The current evidence confirmed that there is no difference in outcomes of hypospadias repair depending on a certain dressing type. To date, surgeon's preference remains the main factor determining the choice for a specific dressing or for no dressing at all.
Metal-Free Synthesis of Guanidines from Thioureas in Water Reactions Mediated by Visible Light
Authors: Wacharasindhu Sumrit , Annuur Rose Malina , Saetan Trin , Sukwattanasinitt Mongkol
Published: March 2023

Metal-free synthesis of guanidines from thioureas under visible-light irradiation in water was successfully developed. Using 1–5 mol% of inexpensive and commercially available phenazine ethosulfate as a photocatalyst in the presence of 1 wt% cetyltrimethylammonium bromide (CTAB) as surfactant with K2CO3 as an additive base, transformations of a variety of thioureas into the corresponding guanidines under visible-light irradiation were achieved in moderate to high yields. The advantages of this reaction include the use of a metal-free photocatalyst, water as a nontoxic solvent, and ease of operating at room temperature in an open-flask manner.
C6–H Bond Functionalization of Indoles: A New Gate
Authors: Saracoglu Nurullah , Taskesenligil Yunus
Published: March 2023

Indoles are valuable precursors in medicinal, bioorganic, and material chemistry and particularly serve as a platform for diversity. However, the scope of the C6-functionalization of indoles was limited until recently. In this short review, we summarize developments in the C6-functionalization reactions of indoles involving transition-metal-catalyzed functionalization and Brønsted and Lewis acid catalyzed processes. The regioselectivity is controlled by remote-C–H activation and hydrogen bond formation.

1 Introduction

2 Transition-Metal-Catalyzed Functionalization

3 Acid-Catalyzed Processes

4 Conclusion
Surgery for Otitis Media with Effusion: A Survey of Otolaryngologists Who Treat Children in Brazil
Authors: Nobrega Manoel de , Carvalho Daniela , Lubianca Neto José Faibes
Published: March 2023

Introduction Myringotomy and ear tube placement (MTP) is the surgical treatment for otitis media with effusion (OME), and it is the most common surgery performed in children. Several guidelines have been developed to assist in the care of patients who become candidates for MTP.

Objectives To evaluate the practice of Brazilian otorhinolarynogologists when performing MTP according to the years of clinical experience. Secondarily, we also want to assess if their practice regarding MTP varied according to the percentage of children treated and the location of their practice.

Methods A 30-question survey was sent to otolaryngologists affiliated with the Brazilian Academy of Pediatric Otorhinolaryngology (Academia Brasileira de Otorrinolaringologia Pediátrica, ABOPe, in Portuguese) and/or the Scientific Department of Otorhinolaryngology of the Brazilian Society of Pediatrics (Sociedade Brasileira de Pediatria, SBP, in Portuguese). The questions included were carefully chosen to provide a profile about the practices adopted in the pre-, peri- and postoperative periods of MTP.

Results The questionnaire was sent to 208 otolaryngologists, and there were 124 (59.6%) respondents. Of those, 59.7% use antiseptics before surgery. Only 54 otolaryngologists, less than half of the subjects in this study (43.5%), always place a tube during the procedure. More physicians who practice in small cities recommend water precautions after MTP when compared to other physicians (p < 0.001).

Conclusion The present study reveals that many respondents do not follow some of the recommendations of the current guidelines of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) on OME, either perioperatively and postoperatively, or regarding the option of placing a ventilation tube. This part of the care also varied depending on the respondents' work location and experience in the medical practice.
Statin Treatment Is Associated with Alterations in the Platelet Lipidome
Authors: Harm Tobias , Frey Moritz , Dittrich Kristina , Goldschmied Andreas , Rohlfing Anne-Katrin , Fu Xiaoqing , Brun Adrian , Castor Tatsiana , Rath Dominik , Müller Karin , Lammerhofer Michael , Gawaz Meinrad
Published: March 2023

Background Platelets are key players in the pathophysiology of coronary artery disease (CAD) and platelet hyperreactivity leads to increased risk of developing adverse cardiovascular events. Further, significant changes in the platelet lipidome occur in patients with acute coronary syndrome (ACS) and critically regulated lipids lead to platelet hyperresponsiveness. Statin treatment is crucial in the treatment and prevention of patients with CAD by remodeling lipid metabolism.

Objective In this study, we investigate the platelet lipidome of CAD patients by untargeted lipidomics, highlighting significant changes between statin-treated and naïve patients.

Methods We characterized the platelet lipidome in a CAD cohort (n = 105) by an untargeted lipidomics approach using liquid chromatography coupled to mass spectrometry.

Results Among the annotated lipids, 41 lipids were significantly upregulated in statin-treated patients, whereas 6 lipids were downregulated compared to naïve patients. The most prominent upregulated lipids in statin-treated patients belong to the class of triglycerides, cholesteryl esters, palmitic acid, and oxidized phospholipids, whereas mainly glycerophospholipids were downregulated compared to untreated patients. A more pronounced effect of statin treatment on the platelet lipidome was observed in ACS patients. We further highlight a dose-dependent influence on the platelet lipidome.

Conclusion Our results reveal that the platelet lipidome is altered in CAD patients with statin treatment and upregulated lipids embody mainly characteristic triglycerides, whereas downregulated lipids mostly compromise glycerophospholipids, which may play a role in the pathophysiology of CAD. Results of this study may contribute to the understanding of statin treatment softening the lipid phenotype.
How not to respond to populism
Authors: Malkopoulou Anthoula , Moffitt Benjamin
Published: March 2023

Although the nature and definition of populism are a source of considerable disagreement, there seems to be a minimal consensus by now that populism poses a number of threats to liberal democracy, and that public authorities should therefore act in defence of the latter. In searching for appropriate responses, however, most scholars draw from strategies for combatting anti-democratic or extremist parties, without considering the important differences between populist parties and these other political actors. We argue that the two central types of democratic defence—the ‘intolerant’ militant democratic defence and the ‘tolerant’ defence—do not offer satisfying responses to populist parties precisely because they were conceived and developed as responses to different phenomena. For public authorities to successfully address populism, responses need to contain its most egregious characteristics, yet salvage its productive side.
Data augmentation-based statistical inference of diffusion processes
Authors: Wang Yasen , Cheng Cheng , Sun Hongwei , Jin Junyang , Fang Huazhen
Published: March 2023

The identification of diffusion processes is challenging for many real-world systems with sparsely sampled observation data. In this work, we propose a data augmentation-based sparse Bayesian learning method to identify a class of diffusion processes from sparsely sampled data. We impute latent unsampled diffusion paths between adjacent observations and construct a candidate model for the diffusion processes with the sparsity-inducing prior on model parameters. Given the augmented data and candidate model, we investigate the full joint posterior distribution of all the parameters and latent diffusion paths under a Bayesian learning framework. We then design a Markov chain Monte Carlo sampler with non-degenerate acceptance probability on system dimension to draw samples from the posterior distribution to estimate the parameters and latent diffusion paths. Particularly, the proposed method can handle sparse data that are regularly or irregularly sampled in time. Simulations on the well-known Langevin equation, homogeneous diffusion in a symmetric double-well potential, and stochastic Lotka–Volterra equation demonstrate the effectiveness and considerable accuracy of the proposed method.
One-dimensional turbulence modeling of compressible flows. I. Conservative Eulerian formulation and application to supersonic channel flow
Authors: Gao Tianyun , Schmidt Heiko , Klein Marten , Liang Jianhan , Sun Mingbo , Chen Chongpei , Guan Qingdi
Published: March 2023

Accurate but economical modeling of supersonic turbulent boundary layers is a standing challenge due to the intricate entanglement of temperature, density, and velocity fluctuations on top of the mean-field variation. Application of the van Driest transformation may describe well the mean state but cannot provide detailed flow information. This lack-in modeling coarse and fine-scale variability is addressed by the present study using a stochastic one-dimensional turbulence (ODT) model. ODT is a simulation methodology that represents the evolution of turbulent flow in a low-dimensional stochastic way. In this study, ODT is extended to fully compressible flows. An Eulerian framework and a conservative form of the governing equations serve as the basis of the compressible ODT model. Computational methods for statistical properties based on ODT realizations are also extended to compressible flows, and a comprehensive way of turbulent kinetic energy budget calculation based on compressible ODT is put forward for the first time. Two canonical direct numerical simulation cases of supersonic isothermal-wall channel flow at Mach numbers 1.5 and 3.0 with bulk Reynolds numbers 3000 and 4880, respectively, are used to validate the extended model. A rigorous numerical validation is presented, including the first-order mean statistics, the second-order root mean square statistics, and higher-order turbulent fluctuation statistics. In ODT results, both mean and root mean square profiles are accurately captured in the near-wall region. Near-wall temperature spectra reveal that temperature fluctuations are amplified at all turbulent scales as the effects of compressibility increase. This phenomenon is caused by intensified viscous heating at a higher Mach number, which is indicated by the steeper profiles of viscous turbulent kinetic energy budget terms in the very near-wall region. The low computational cost and predictive capabilities of ODT suggest that it is a promising approach for detailed modeling of highly turbulent compressible boundary layers. Furthermore, it is found that the ODT model requires a Mach-number-dependent increase in a viscous penalty parameter Z in wall-bounded turbulent flows to enable accurate capture of the buffer layer.
A universal method for analyzing copolymer growth
Authors: Qureshi Benjamin , Juritz Jordan , Poulton Jenny M. , Beersing-Vasquez Adrian , Ouldridge Thomas E.
Published: March 2023

Polymers consisting of more than one type of monomer, known as copolymers, are vital to both living and synthetic systems. Copolymerization has been studied theoretically in a number of contexts, often by considering a Markov process in which monomers are added or removed from the growing tip of a long copolymer. To date, the analysis of the most general models of this class has necessitated simulation. We present a general method for analyzing such processes without resorting to simulation. Our method can be applied to models with an arbitrary network of sub-steps prior to addition or removal of a monomer, including non-equilibrium kinetic proofreading cycles. Moreover, the approach allows for a dependency of addition and removal reactions on the neighboring site in the copolymer and thermodynamically self-consistent models in which all steps are assumed to be microscopically reversible. Using our approach, thermodynamic quantities such as chemical work; kinetic quantities such as time taken to grow; and statistical quantities such as the distribution of monomer types in the growing copolymer can be directly derived either analytically or numerically from the model definition.
Velocity feedback control method of low-frequency electromagnetic vibration exciter based on Kalman filter estimation
Authors: Li Wei , Cui Junning , Bian Xingyuan , Zou Limin
Published: March 2023

The absence of an appropriate low-frequency vibration velocity detection method to establish feedback control limits the further improvement of the low-frequency vibration performance of electromagnetic vibration exciters. In this article, a low-frequency vibration velocity feedback control method based on the Kalman filter estimation is proposed for the first time to reduce the total harmonic distortion of the vibration waveform. The rationality of establishing velocity feedback control in the velocity characteristic band of the electromagnetic vibration exciter is analyzed. Based on an identification model of the system and measured vibration displacements, the vibration velocity is estimated with high accuracy through the Kalman filter. The velocity feedback control system is established to suppress the impacts of disturbances effectively. Experimental results show that the method proposed in this paper can reduce the harmonic distortion of vibration waveform by 40%, which is 20% higher than the traditional control method, thoroughly verifying its superiority.
Multicomponent wavefunction-in-DFT embedding for positronium molecules
Authors: Moncada Félix , Reyes Andrés
Published: March 2023

This work presents an extension of the projector operator embedding scheme of Manby et al. [J. Chem. Theory Comput. 8, 2564 (2012)] in a multicomponent (MC) framework. Here, a molecular system containing electrons and other types of quantum species is divided into a wavefunction (WF) subsystem of interest and a density functional theory (DFT) environment. The WF-in-DFT partition decreases computational costs by partially truncating the WF subsystem basis set at the cost of introducing a controllable embedding error. To explore the applicability of the MC extension, third-order propagator-in-DFT calculations were performed for positron–anion complexes for alkoxides and carboxylates with carbon chains of different sizes. For these systems, it was found that selecting a WF subsystem with the positron and only the oxygen atoms caused an error of 0.1 eV or lower in positron-binding energies, while reducing between 33% and 55% the basis set size. The reduction of computational costs achieved with the embedding scheme allowed us to improve molecular positron-binding energy predictions by performing complete basis set limit extrapolations. Combining the WF-in-DFT embedding and the complete basis set extrapolation, positronium aliphatic alkoxides were predicted to be energetically stable by 0.3 eV with respect to Ps emission. Similarly, positronium carboxylates, both aromatic and aliphatic, were predicted to be stable by 1.3 eV.
Indirect nuclear spin–spin couplings with third-order contributions added to the SOPPA method
Authors: Rodrigo Javier Sanz , Hillers-Bendtsen Andreas Erbs , Kjeldal Frederik Ø. , Høyer Nicolai M. , Mikkelsen Kurt V. , Sauer Stephan P. A.
Published: March 2023

In this article, a modification of the second-order polarization propagator approximation (SOPPA) method is introduced and illustrated for the calculation of the indirect nuclear spin–spin couplings. The standard SOPPA method, although cheaper in terms of computational cost, offers less accurate results than the ones obtained with coupled cluster methods. A new method, named SOPPA+A3-3, was therefore developed by adding the terms of the third-order A matrix that rely on the second-order double amplitudes. The performance of this third-order contribution was studied using the coupled cluster singles and doubles method as a reference, calculating the spin–spin couplings of molecules of diverse sizes and compositions, and comparing them to the SOPPA method. The results show that inclusion of this third-order contribution gives more accurate results than the standard SOPPA method with a level of accuracy close to that of the coupled cluster method with only a small increase in the computational cost of the response calculation that dominates the computational cost for small- to medium-sized molecules. The implementation of the first contributions to the third-order polarization propagator approximation in the Dalton program, thus, already shows a significant change in these molecular properties over those obtained with the standard SOPPA method.
Three-dimensional wall heating elements effect on the instability in zero pressure gradient supersonic boundary layers
Authors: Bi Zhouhua , Wang Ping , Xu Jiakuan , Liu Jianxin
Published: March 2023

The streaky boundary layers have very important roles in laminar-turbulent transition. Streaks of appropriate size can influence stabilities in boundary layers. In this paper, the effect of steady streamwise elongated, spanwise periodic wall heating elements on the first mode instability in supersonic flat plate boundary layers was investigated. For the balance of the efficient and accuracy, the linearized Navier–Stokes equations are used to obtain the base flow and compared with compressible Navier–Stokes equations. A bi-global analysis tool is used for the instability analysis because the heating source has a much larger length-scale in the streamwise direction than that in the spanwise direction, and the streamwise velocity is much larger than the normal velocity and the spanwise one. Results indicated that the distortion caused by the three-dimensional surface heating elements could modify the first mode, resulting in a lower frequency but with an uncertain effect on the higher frequency modes. Additionally, the streaks make the lower spanwise wave number components of the even first mode disturbance in a three-dimensional supersonic boundary layer in the freestream. As a result, the spontaneous radiation of an acoustic wave to the far field was found for the even mode. These findings suggest that laminar-turbulence transition can be suppressed or enhanced by the three-dimensional wall heating.
Stacking strategy-assisted random forest algorithm and its application
Authors: Wang Kun , Gao Jinggeng , Li Hu , Liang Li
Published: March 2023

Short-term power load forecasting provides important guidance for the improvement of power marketing and control levels of power enterprises. In this paper, a novel method, named RF-TStacking, is proposed to forecast the short-term load. This study starts from the influence factors of the power load, the random forest is applied to estimate the importance of the influence factors of short-term load. Based on Stacking strategy, the integration of LightGBM and random forest is realized to achieve short-term power load forecasting. To improve the generalization ability of the load model, random put back sampling is used to sample each primary learner, and the average value is taken as the result of each primary learner. The Bayesian optimization is used to adjust the super parameters of the model to improve the accuracy of the selection of influencing factors. The load data of a region in northwest China are used for the testing, and it is found that the model can provide stable prediction results.
A Cartesian grid-based two-dimensional plus time method for simulating ship bow waves
Authors: Zhang Yifan , Zhang Yunxing , Ma Shan , Shao Wenbo , Liu Jianyu , Chen Xiaobo
Published: March 2023

Numerical modeling of ship bow waves is still hard work, partly due to their multiscale features. Direct three-dimensional (3D) computational fluid dynamics simulation could be an appropriate choice to investigate the problem. However, limited by computational resources, small scale phenomena such as spraying and wave breaking that could be observed during the ship wave generation process are usually simplified or not fully distinguished in a 3D simulation. In order to accurately capture the small scales flow field information with the available computational resource, a new Cartesian grid-based two-dimensional plus time (2D+t) method is developed in this paper, which is suitable for 3D slender ships. With this method, a 3D steady ship wave-making problem is transformed into a 2D unsteady wave-making problem of a deformable body. The boundary velocity of the deformable body is obtained with a novel interpolation algorithm, which is then enforced on the background Cartesian grid by a newly proposed immersed boundary method. The pressure boundary condition on the surface of the deformable body is explicitly considered in the solution of the pressure Poisson equation. Moreover, an extra open boundary condition is applied to the upper boundary of the computational domain to achieve a better conservation. The proposed model is validated with selected cases, showing that the model is capable of simulating both non-wave-breaking and wave-breaking problems.
Toward an efficient implementation of internally contracted coupled-cluster methods
Authors: Black Joshua A. , Waigum Alexander , Adam Robert G. , Shamasundar K. R. , Köhn Andreas
Published: March 2023

A new implementation of the internally contracted multireference coupled-cluster with singles and doubles (icMRCCSD) method is presented. The new code employs an efficient tensor contraction kernel and can also avoid full four-external integral transformations, which significantly extends the scope of the applicability of icMRCCSD. The new implementation is currently restricted to the simple case of two active electrons in two orbitals and also supports the computation of spin-adapted doublet and triplet coupled-cluster wavefunctions. This contribution describes the basic approach for the automated derivation of working equations and benchmarks the current code against efficient implementations of standard methods, such as single-reference coupled-cluster singles and doubles (CCSD) and internally contracted multireference configuration interaction (icMRCI). Run times for linearized variants of icMRCCSD are only twice as long as comparable CCSD runs and similar to those of the icMRCI implementation, while non-linear terms of more complete variants of icMRCCSD lead to an order of magnitude longer computation times. Nevertheless, the new code allows for computations at larger scales than it was possible previously, with less demands on memory and disk-space resources. This is exemplified by numerical structure optimizations and harmonic force field determinations of NC2H5 isomers and the singlet and triplet states of m-benzyne. In addition, the exchange coupling of a dinuclear copper complex is determined. This work also defines a new commutator approximation for icMRCCSD, which includes all terms that are also present in the single-reference CCSD method, thus yielding a consistent pair of single-reference and multireference coupled-cluster methods.
A general-purpose machine learning Pt interatomic potential for an accurate description of bulk, surfaces, and nanoparticles
Authors: Kloppenburg Jan , Pártay Livia B. , Jónsson Hannes , Caro Miguel A.
Published: March 2023

A Gaussian approximation machine learning interatomic potential for platinum is presented. It has been trained on density-functional theory (DFT) data computed for bulk, surfaces, and nanostructured platinum, in particular nanoparticles. Across the range of tested properties, which include bulk elasticity, surface energetics, and nanoparticle stability, this potential shows excellent transferability and agreement with DFT, providing state-of-the-art accuracy at a low computational cost. We showcase the possibilities for modeling of Pt systems enabled by this potential with two examples: the pressure–temperature phase diagram of Pt calculated using nested sampling and a study of the spontaneous crystallization of a large Pt nanoparticle based on classical dynamics simulations over several nanoseconds.
The kinetics of the PuO2 to Pu2O3 conversion
Authors: Dinh L. N. , Donald S. B. , Stanford J. A. , Saw C. K. , Gollott R. , Haschke J. M. , McLean W.
Published: March 2023

In an oxidizing environment, the oxide formed on plutonium (Pu) metal is composed of a plutonium dioxide (PuO2) top layer and a thin cubic plutonium sesquioxide (Pu2O3) middle layer. In a reducing environment, the PuO2 layer auto-reduces to cubic Pu2O3. The speed and extent of this conversion depend on the combination of temperature and time. While PuO2 provides a strong diffusion barrier against unwanted Pu corrosion by gaseous species (like hydrogen), Pu2O3 does not, since its crystal structure has chains of oxygen vacancies. The kinetics of the PuO2 reduction are, therefore, of fundamental interest and enable researchers to better protect Pu from corrosion. In this report, the oxygen-diffusion-limited kinetics of the dioxide to sesquioxide conversion were obtained by dynamically heating a PuO2-covered Pu sample from 294 to 418 K in a high-vacuum vessel equipped with an in situ spectroscopic ellipsometer. The physical/chemical constraints in the conversion process were combined with the ellipsometry method of multi-sample analysis to track the percentage of PuO2 and to compute the extent of Pu2O3 formation. The resulting diffusion coefficients were compared against and then combined with complementary literature data to produce a comprehensive set of kinetic parameters for reliably modeling oxide conversion over a larger temperature range than spanned by prior studies. The extracted thermal activation energy barrier (43.7 kJ/mol) and pre-exponential factor (5.0 × 10−10 cm2/s) for the oxygen-diffusion-limited process can be used to accurately model the PuO2 to Pu2O3 transformation in vacuum and/or inert gas applications.
Shape optimization and demagnetization analysis of interior permanent magnet synchronous machine with hybrid cores
Authors: Liu Chengcheng , Huang Xiaorui , Zhang Wenfeng , Wang Youhua
Published: March 2023

With designing stator teeth by using grain oriented silicon sheets (GO) and other parts still with non-grain oriented silicon sheets (NGO), the electromagnetic performance of interior permanent magnet synchronous machine (GO-IPMSM) can be improved greatly, however its torque ripple will be increased as well. For reducing its torque ripple, optimizing its rotor barrier shape is an effective way. In this paper, the polynomial method is proposed to establish the rotor barrier shape, and the genetic algorithm (GA) method is employed for the optimization process. In case the optimized GO-IPMSM can work normally, its anti irreversible demagnetization ability is analyzed as well. As shown, with the GO is adopted for designing the stator teeth and its rotor barrier shape is optimized, though its torque ability and efficiency have been increased, its anti irreversible demagnetization risk ability is reduced, however the proposed machine can still operate safely.
Toward new tools for biodiversity studies: the use of portable near-infrared spectroscopy combined with machine learning to identify species of Decapoda
Authors: Carvalho Fabrício Lopes , Novais Wendel Resende Ramos , Soares-Silva Ana Carla , Flores Douglas William Menezes , Magalhães Robson da Silva
Published: March 2023

Context Accuracy in species identification is a crucial factor for the quality of biodiversity studies and species management. Ensuring high accuracy is challenging for diverse taxonomic groups, including those with fishery importance such as Decapoda. Aims The objective of the present study was to use portable near-infrared spectroscopy combined with machine learning through a neural network (ANN) to identify species of Decapoda. Methods We propose an ANN application that rapidly and accurately emulates the results that would be obtained by a specialist. We used 124 specimens from seven marine Decapoda species as a dataset to fit the model. Key results The ANN was able to correctly learn (classify) all the patterns of the species (100% accuracy), with an overall mean probability of 0.97 ± 0.068. Conclusions The results obtained using portable near-infrared spectroscopy combined with machine learning (ANN) demonstrated that this method can be used with high accuracy to distinguish Decapoda species. Implications Studies aiming at comparisons among species may consider the use of this technique for the precise and inexpensive separation among species by non-specialists or for species that require the identification of a large number of individuals.
Resolution of the Eremophila tietkensii (Scrophulariaceae) species complex based on congruence between morphological and molecular pattern analyses
Authors: Curtis Amy L. , Grierson Pauline F. , Batley Jacqueline , Naaykens Jeremy , Fowler Rachael M. , Severn-Ellis Anita , Thiele Kevin R.
Published: March 2023

Eremophila R.Br. comprises at least 238 species endemic to Australia, with many more having not yet been formally described. Three putative new taxa, namely, E. sp. Hamersley Range (K. Walker KW 136), E. sp. Calvert Range (A. A. Burbidge 738) and E. sp. Rudall River (P. G. Wilson 10512), were segregated from a broadly defined E. tietkensii F.Muell. & Tate by J. Hurter at the Western Australian Herbarium in 2012. Both E. sp. Hamersley Range and E. sp. Rudall River are listed as being of conservation concern in Western Australia, the former occurring in the Pilbara region in areas of prospective interest for mining development. We sought to determine whether these phrase-named entities should be formally described as new species, using multivariate analyses of morphometric and molecular data derived from specimens in the Western Australia Herbarium. Eremophila sp. Rudall River could not be adequately separated from E. tietkensii by either morphological or molecular data, and is here included within that species. By contrast, E. sp. Hamersley Range and E. sp. Calvert Range are clearly morphologically and genetically distinct. We thus describe them here as the new species E. naaykensii A.L.Curtis & K.R.Thiele and E. hurteri A.L.Curtis & K.R.Thiele. The recognition of these taxa will help inform their conservation prioritisation and subsequent management.
Propofol disrupts alpha dynamics in functionally distinct thalamocortical networks during loss of consciousness
Authors: Weiner Veronica S. , Zhou David W. , Kahali Pegah , Stephen Emily P. , Peterfreund Robert A. , Aglio Linda S. , Szabo Michele D. , Eskandar Emad N. , Salazar-Gomez Andrés F. , Sampson Aaron L. , Cash Sydney S. , Brown Emery N. , Purdon Patrick L.
Published: March 2023

During propofol-induced general anesthesia, alpha rhythms measured using electroencephalography undergo a striking shift from posterior to anterior, termed anteriorization, where the ubiquitous waking alpha is lost and a frontal alpha emerges. The functional significance of alpha anteriorization and the precise brain regions contributing to the phenomenon are a mystery. While posterior alpha is thought to be generated by thalamocortical circuits connecting nuclei of the sensory thalamus with their cortical partners, the thalamic origins of the propofol-induced alpha remain poorly understood. Here, we used human intracranial recordings to identify regions in sensory cortices where propofol attenuates a coherent alpha network, distinct from those in the frontal cortex where it amplifies coherent alpha and beta activities. We then performed diffusion tractography between these identified regions and individual thalamic nuclei to show that the opposing dynamics of anteriorization occur within two distinct thalamocortical networks. We found that propofol disrupted a posterior alpha network structurally connected with nuclei in the sensory and sensory associational regions of the thalamus. At the same time, propofol induced a coherent alpha oscillation within prefrontal cortical areas that were connected with thalamic nuclei involved in cognition, such as the mediodorsal nucleus. The cortical and thalamic anatomy involved, as well as their known functional roles, suggests multiple means by which propofol dismantles sensory and cognitive processes to achieve loss of consciousness.
A complete biomechanical model of
Hydra
contractile behaviors, from neural drive to muscle to movement
Authors: Wang Hengji , Swore Joshua , Sharma Shashank , Szymanski John R. , Yuste Rafael , Daniel Thomas L. , Regnier Michael , Bosma Martha M. , Fairhall Adrienne L.
Published: March 2023

How does neural activity drive muscles to produce behavior? The recent development of genetic lines in
Hydra
that allow complete calcium imaging of both neuronal and muscle activity, as well as systematic machine learning quantification of behaviors, makes this small cnidarian an ideal model system to understand and model the complete transformation from neural firing to body movements. To achieve this, we have built a neuromechanical model of
Hydra
’s fluid-filled hydrostatic skeleton, showing how drive by neuronal activity activates distinct patterns of muscle activity and body column biomechanics. Our model is based on experimental measurements of neuronal and muscle activity and assumes gap junctional coupling among muscle cells and calcium-dependent force generation by muscles. With these assumptions, we can robustly reproduce a basic set of
Hydra
’s behaviors. We can further explain puzzling experimental observations, including the dual timescale kinetics observed in muscle activation and the engagement of ectodermal and endodermal muscles in different behaviors. This work delineates the spatiotemporal control space of
Hydra
movement and can serve as a template for future efforts to systematically decipher the transformations in the neural basis of behavior.
Self-propulsion via slipping: Frictional swimming in multilegged locomotors
Authors: Chong Baxi , He Juntao , Li Shengkai , Erickson Eva , Diaz Kelimar , Wang Tianyu , Soto Daniel , Goldman Daniel I.
Published: March 2023

Locomotion is typically studied either in continuous media where bodies and legs experience forces generated by the flowing medium or on solid substrates dominated by friction. In the former, centralized whole-body coordination is believed to facilitate appropriate slipping through the medium for propulsion. In the latter, slip is often assumed minimal and thus avoided via decentralized control schemes. We find in laboratory experiments that terrestrial locomotion of a meter-scale multisegmented/legged robophysical model resembles undulatory fluid swimming. Experiments varying waves of leg stepping and body bending reveal how these parameters result in effective terrestrial locomotion despite seemingly ineffective isotropic frictional contacts. Dissipation dominates over inertial effects in this macroscopic-scaled regime, resulting in essentially geometric locomotion on land akin to microscopic-scale swimming in fluids. Theoretical analysis demonstrates that the high-dimensional multisegmented/legged dynamics can be simplified to a centralized low-dimensional model, which reveals an effective resistive force theory with an acquired viscous drag anisotropy. We extend our low-dimensional, geometric analysis to illustrate how body undulation can aid performance in non–flat obstacle-rich terrains and also use the scheme to quantitatively model how body undulation affects performance of biological centipede locomotion (the desert centipede
Scolopendra polymorpha
) moving at relatively high speeds (∼0.5 body lengths/sec). Our results could facilitate control of multilegged robots in complex terradynamic scenarios.