bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Hydrodynamic Characteristics of Non‐Newtonian Polymer Solution Fluid in Concentric Annulus Using Computational Fluid Dynamics Methods
Authors: He Yu , He Guangwen , Yu Bin , Yan Shaowei , Xie Le
Published: October 2021

Non‐Newtonian fluids flowing in a concentric annulus have been widely observed in industrial chemical processes. In this study, the hydrodynamic characteristics of a non‐Newtonian fluid (polymer solution) in concentric annulus are investigated using computational fluid dynamics (CFD) modeling and numerical simulation methods. First, a simple grid independence analysis is carried out to select appropriate grid parameters. Then the rationality of the proposed CFD model is confirmed by the near‐wall velocity profiles. Based on the validated model, the effects of the fluid properties and radius ratio on the flow structure characteristics are studied at various inlet velocities. According to the simulated flow fields (i.e., velocity, pressure, strain rate, and wall shear stress), the flow pattern, flow resistance, and residence time distribution characteristics are analyzed in the laminar and turbulent regimes. The presented results show that non‐Newtonian fluids have unique flow behaviors in concentric annulus when compared with Newtonian fluids.
Intermittent versus daily regimen of prednisolone in ambulatory boys with Duchenne muscular dystrophy: A randomized, open‐label trial
Authors: Kochar Gurpreet S. , Sondhi Vishal , Kabra Sushil K. , Yadav Shiv L. , Dwivedi Sada N. , Gulati Sheffali
Published: October 2021

Introduction/Aims

Corticosteroids prolong ambulation and improve muscle power among boys with Duchenne muscular dystrophy (DMD). However, the optimal steroid regimen remains unclear. Hence, this study was undertaken to compare the efficacy of daily‐ versus intermittent‐steroid regimens in ambulatory boys with DMD.

Methods

In this single‐center, open‐label randomized trial, 72 children were randomized to receive either daily prednisolone (0.75 mg/kg/day) or intermittent prednisolone (0.75 mg/kg/day, for first 10 days of every month). The primary outcome measure was the difference in average score on manual muscle testing (MMT) at baseline and after 6 mo of steroids. A difference of >0.2 was hypothesized to be significant. Secondary outcomes included changes in timed functions, muscular dystrophy‐specific functional‐rating scale score, peak torque, average power, and pulmonary function.

Results

In the intention‐to‐treat analysis, the mean (SD) change in MMT scores was 0.17 (0.15) and 0.08 (0.10) for the daily and intermittent steroid groups, respectively. The mean difference between the two interventions was 0.10 (95% confidence interval [CI] = 0.04–0.16; P = .003), which although significant was less than the predefined value of 0.2. Statistically significantly improvements were observed with daily‐steroid regimen in the Gowers time (P = .01), nine‐metre walk test (P = .02) and average power (P = .02) as compared to intermittent‐steroid regimen. A total of 19/32 (52.8%) children in the daily‐steroid group and 8/29 (27%) children in the intermittent‐steroid group experienced some form of adverse effect (P = .02).

Discussion

Over a short‐term period, the intermittent‐steroid regimen was non‐inferior to the daily‐steroid regime in preserving muscle strength among children with DMD. However, better improvement of functional measures was observed with daily‐steroid administration. The frequency of individual side effects was similar between the two groups.
Formulation and implementation of an elastoplastic constitutive model for sand‐fines mixtures
Authors: Sun ZengChun , Chu Jian , Xiao Yang
Published: October 2021

Sand‐fines mixtures are commonly used engineered materials, and their mechanical behavior is significantly affected by density, confining pressure, as well as fines content. Although many laboratory tests have been performed on sand‐fines mixtures, few works have been conducted on its constitutive law. To adequately describe the mechanical behavior of sand with different fines content, a novel elastoplastic constitutive model was developed for sand‐fines mixtures by incorporating an equivalent granular state parameter into Rowe's stress‐dilatancy equation, plastic modulus, and in conjunction with the correlation between the critical state and fines content. Subsequently, the Runge‐Kutta schemes with automatic error control are adopted for the proposed model and implemented in a finite element code. The performance of the fines‐state‐dependent model with the Runge‐Kutta schemes, in terms of accuracy, efficiency and convergence, is verified by analyzing element scale tests and boundary value problems. The comparisons of simulated and experimental results demonstrate that the fines‐state‐dependent model can effectively capture the strain hardening (or softening) and contraction (or dilatancy) behaviors of sand‐fines mixtures under drained conditions. In addition, the key features under undrained conditions, such as flow, limited flow, and non‐flow behaviors can also be reasonably reproduced.
On hybrid convolution quadrature approaches for modeling time‐domain wave problems with broadband frequency content
Authors: Rowbottom Jacob , Chappell David J.
Published: October 2021

We propose two hybrid convolution quadrature based discretizations of the wave equation on interior domains with broadband Neumann boundary data or source terms. The convolution quadrature method transforms the time‐domain wave problem into a series of Helmholtz problems with complex‐valued wavenumbers, in which the boundary data and solutions are connected to those of the original problem through the ‐transform. The hybrid method terminology refers specifically to the use of different approximations of these Helmholtz problems, depending on the frequency. For lower frequencies, we employ the boundary element method, while for more oscillatory problems, we develop two alternative high frequency approximations based on plane wave decompositions of the acoustic field on the boundary. In the first approach, we apply dynamical energy analysis to numerically approximate the plane wave amplitudes. The phases will then be reconstructed using a novel approach based on matching the boundary element solution to the plane wave ansatz in the frequency region where we switch between the low and high frequency methods. The second high frequency method is based on applying the Neumann‐to‐Dirichlet map for plane waves to the given boundary data. Finally, we investigate the effectiveness of both hybrid approaches across a range of numerical experiments.
The full story: Understanding how films affect environmental change through the lens of narrative persuasion
Authors: McCormack Christopher Michael , K. Martin Jennifer , Williams Kathryn J. H.
Published: October 2021

Researchers in conservation fields have recently highlighted the potential for visual storytelling to convey environmental messages to large audiences. However, an effective model for how such narratives can produce environmental outcomes, such as human–nature connection and pro‐environmental behaviour (PEB), has not yet been developed.

Substantial evidence now suggests that narrative is an effective means of changing beliefs, attitudes and behaviours. This effect is demonstrated in diverse disciplines and understood within the theoretical frameworks of narrative persuasion.

We propose a conceptual framework for understanding the impacts of environmental films on environmental behaviours, and connection with nature. Linking insights from the narrative persuasion field with those of conservation psychology, we identify three promising pathways through which environmental films might influence their audiences: (a) reduced resistance to environmental messages, (b) interactions with audience identity and (c) meaningful media experiences.

This analysis raises key questions and illuminates priority areas for future research, with an aim to complement and extend existing calls to better appreciate the role of film in addressing environmental problems. Research moving forward should focus on understanding the role environmental films can play in connecting people with nature, promoting PEB and the relationship between the two. Specifically, more attention should be paid to the role of deictic shift in encouraging environmental outcomes, the relation between audiences and characters and the power for film to support self‐expansion.

A free Plain Language Summary can be found within the Supporting Information of this article.
Comparing efficacy and side effects of two systemic chemotherapy regimens for eye‐preserving therapy in children with retinoblastoma
Authors: Grümme Lea , Biewald Eva , Reschke Madlen , Fischhuber Karen , Hanbücken Anna , Schlüter Sabrina , Müller Bert , Kiefer Tobias , Göricke Sophia , Geismar Dirk , Ryl Tatsiana , Sirin Selma , Wieland Regina , Timmermann Beate , Lohmann Dietmar , Ebinger Martin , Brecht Ines B. , Schönberger Stefan , Schwab Christoph , Eggert Angelika , Süsskind Daniela , Ritter‐Sovinz Petra , Bechrakis Nikolaos E. , Ketteler Petra
Published: October 2021

Background

Eye‐preserving therapy in retinoblastoma comprises systemic chemotherapy, but studies analyzing the efficacy of different chemotherapy regimens are scarce.

Methods

The efficacy and side effects of two different eye‐preserving chemotherapy regimens containing either vincristine, etoposide, and carboplatin (VEC) or cyclophosphamide, vincristine, etoposide, and carboplatin (CyVEC) were compared in a prospective non‐interventional observational study including children diagnosed with retinoblastoma between 2013 and 2019 in Germany and Austria. Event‐free eye survival (EFES) and overall eye survival (OES) of all 164 eyes treated with both regimens and risk factors were investigated.

Results

The EFES after VEC (2‐year EFES 72.3%) was higher than after CyVEC (2‐year EFES 50.4%) (plogrank < .001). The OES did not differ significantly between the two treatment groups (plogrank = .77; 2‐year OES VEC: 82.1% vs. CyVEC: 84.8%). Advanced International Classification of Retinoblastoma (ICRB) group was prognostic for a lower EFES (plogrank < .0001; 2‐year EFES ICRB A/B/C 71.3% vs. ICRB D/E 43.0%) and OES (plogrank < .0001; 2‐year OES ICRB A/B/C 93.1% vs. ICRB D/E 61.5%). The multivariate analysis showed that age at diagnosis older than 12 months and ICRB A/B/C were associated with better EFES. No second malignancies or ototoxicities were reported after a follow‐up of median 3.1 years after diagnosis of retinoblastoma (range 0.1–6.9 years).

Conclusions

Despite omitting cyclophosphamide, the EFES was higher after VEC chemotherapy that contains higher doses of carboplatin compared to CyVEC. The major risk factor for enucleation was advanced ICRB tumor grouping. Randomized clinical trials on efficacy and side effects of eye‐preserving chemotherapy are required to tailor treatment protocols for retinoblastoma patients.
Severe hypertransaminasemia during mild SARS‐CoV‐2 infection: A pediatric case report and literature review
Authors: Palpacelli Alessandra , Martelli Gaia , Lattanzi Bianca , Volpini Alessandro , Cazzato Salvatore
Published: October 2021

Introduction

Liver injury during SARS‐CoV‐2 infection has a multifactorial pathogenesis and it is frequent in pediatric cases.

Case presentation

We report a case with severe hypertransaminasemia associated with mild SARS‐CoV‐2 infection.

Conclusion

This highlights the potential need of hepatic function evaluation during acute illness and follow‐up even in non‐critically ill children with COVID‐19.
Information communication technology use and school belonging in Australian high school students
Authors: McCahey Angela , Allen Kelly‐Ann , Arslan Gokmen
Published: October 2021

School belonging is an important component of adolescent well‐being, yet little is known about its relationship with adolescents' Information Communication Technology (ICT) use. This study aimed to examine the relationship between school belonging and various ICT use types in Australian adolescents. The sample was drawn from 14,530 Australian students in Grade 7 or higher, who completed the 2015 Organization for Economic Cooperation and Development's Program for International Student Assessment survey. A hierarchical regression analysis was conducted to investigate the relationship between self‐reported measures of school belonging and ICT use at home for schoolwork and ICT use at home for leisure, adjusting for covariates (age, gender, and economic, social, and cultural status). The regression model accounted for 3% of the variability of sense of school belonging, R2 = 0.03, F(5, 10196) = 60.00, p < .001. After adjusting for covariates, more frequent ICT use at home for schoolwork predicted a higher sense of school belonging. Conversely, more frequent ICT use at home for leisure predicted lower levels of sense of school belonging. The way adolescents engage with ICT is important for a student's sense of school belonging, and the present findings have implications for researchers and psychologists.
Early nasal continuous positive airway pressure failure prediction in preterm infants less than 32 weeks gestational age suffering from respiratory distress syndrome
Authors: Dell'Orto Valentina , Nobile Stefano , Correani Alessio , Marchionni Paolo , Giretti Ilaria , Rondina Clementina , Burattini Ilaria , Palazzi Maria L. , Carnielli Virgilio P.
Published: October 2021

Background

Early continuous positive airway pressure (CPAP) and surfactant replacement are effective treatments for neonatal respiratory distress syndrome (RDS). CPAP is the first line in preterm infants needing respiratory support, with surfactant replacement in case of CPAP failure (CPAP‐F).

Objectives

To analyze incidence and factors associated with CPAP‐F in preterm infants with RDS.

Design, Setting and Patients

Single‐center retrospective database analysis (2004–2017) of inborn infants, gestational age (GA) 24 + 0/7–31 + 6/7 weeks, not intubated on admission to the neonatal intensive care unit, managed with CPAP. CPAP‐F was defined as intubation and surfactant administration in the first 72 h of life; CPAP success (CPAP‐S) was CPAP alone without need for additional RDS treatments. Demographic, respiratory, and clinical data associated with CPAP‐F were studied using logistic regression analysis.

Results

A total of 562 infants met the inclusion criteria: 252 (44.8%) were CPAP‐F and 310 (55.2%) were CPAP‐S. The CPAP‐F, compared to CPAP‐S group, had lower GA and birth weight, and were less likely to receive antenatal steroids or to be vaginal births. Logistic regression showed that the fraction of inspired oxygen (FiO2) ≥ 0.23 between 180 and 240 min of life (FiO2 180–240 min) was the strongest factor associated with CPAP‐F (odds ratio: 16.01 [95% confidence interval: 10.34–24.81]).

Conclusion

FiO2 180–240 min was highly predictive of CPAP‐F in preterm infants. With this model for surfactant administration/CPAP‐F, 11.2% of infants would have unnecessarily received treatment, but importantly, 27.7% would have been treated much earlier, with a potential reduction in air leaks and duration of mechanical ventilation.
The Impact of Surface Voltage on Photoluminescence Response for the Detection of Copper and Iron Contamination in Silicon
Authors: Nassiet Thomas , Duru Romain , Le-Cunff Delphine , Bremond Georges , Bluet Jean-Marie
Published: October 2021

Herein, silicon substrates intentionally contaminated by iron and copper are analyzed by an innovative technique based on photoluminescence (PL) measurement, with the aim to evaluate the sensitivity of this technique to low level contamination and its capability for further in‐line monitoring during devices fabrication. Measurements are carried out directly after samples preparation, with the combined use of PL and corona discharges to separate the contribution of metallic contamination from interface properties on the PL signal. The sensitivity of PL to both iron and copper contamination in silicon with higher sensitivity when surface recombination is minimized is shown. Therefore, this work highlights the importance of surface properties monitoring for the optimization of PL detection of metallic contamination.
Strong Electron–Phonon Coupling in 3D WN and Coexistence of Intrinsic Superconductivity and Topological Nodal Line in Its 2D Limit
Authors: Chen Jianyong , Gao Jiacheng
Published: October 2021

The electron–phonon coupling (EPC) and superconductivity in three‐component‐fermion materials WN, WC, and TaN are systematically investigated using first‐principles calculations. The EPC strength in pristine or pressurized WC and TaN are found to be negligibly weak (<0.2), but can be enhanced significantly by electron doping, and the predicted transition temperatures (Tc) reach the values observed in experiments (≈4 K), demonstrating the vital role of charge doping in the formation of superconductivity. Surprisingly, pristine WN has strong EPC due to a synergistic effect of strong Fermi nesting and large deformation potential and behaves as a good superconductor with Tc of 31 K. Going down from 3D to 2D, WN thin film (i.e., monolayer W3N4) is also predicted to be an intrinsic superconductor with Tc of 11 K. Most importantly, monolayer W3N4 hosts nodal lines that are robust against spin–orbit coupling (SOC), close to the Fermi level and apart from other trivial bands, which are scarce in real materials. The coexistence of high‐transition‐temperature superconductivity and topological states in 3D and 2D WN render them promising platforms for realizing topological superconductivity.
Molecular mechanism of anti‐adipogenic effect of vitexin in differentiating hMSCs
Authors: Gire Dhananjay , Acharya Jhankar , Malik Sajad , Inamdar Shrirang , Ghaskadbi Saroj
Published: October 2021

In this study, we evaluated a detailed molecular mechanism of anti‐adipogenic activity of vitexin, apigenin flavone glucoside, present in germinated fenugreek seeds, in differentiating human mesenchymal stem cells (hMSCs). The lipid content of differentiated adipocytes was estimated by ORO staining. Effect on mitotic clonal expansion was checked by cell cycle analysis. Expression of early and terminal adipocyte differentiation markers, anti‐ and pro‐adipogenic transcription factors and signalling intermediates regulating them was evaluated at RNA and protein level. We found vitexin to be non‐cytotoxic up to 20 μM at which intracellular lipid accumulation was significantly decreased. Cell cycle analysis suggested that vitexin does not affect mitotic clonal expansion. Expression of early and late differentiation markers, such as CEBPα, CEBPβ, PPARγ, FABP4, perilipin, adiponectin and Glut4 was significantly reduced in the presence of vitexin. Expression of KLF4 and KLF15, positive regulators of PPARγ, was decreased, whereas that of negative regulators, namely KLF2, GATA2, miR20a, miR27a, miR27b, miR128, miR130a, miR130b, miR182 and miR548 increased with vitexin treatment. This effect was mediated by the activation of the AMP‐activated protein kinase (AMPK) pathway via the activation of LepR and additionally by inhibiting ROS. Thus, our results showed that vitexin regulates the expression of PPARγ and inhibits adipogenesis of hMSCs at an early stage of differentiation.
Structural characterization of Chemical Weapons Convention‐related phosphonoselenoates by electron ionization and electrospray ionization mass spectrometry
Authors: Hosseini Seyed Esmaeil , Mousavi Faraz Sajjad , Naseri Mohammad Taghi , Ashrafi Davood , Saeidian Hamid
Published: October 2021

Rationale

Organophosphorus compounds with phosphorus atom bonded to one methyl, ethyl or propyl (normal or iso) group are listed in Schedule 2 of the Chemical Weapons Convention (CWC). Selenophosphorus compounds, listed in Schedule 2.B.4, have very limited representation in mass spectral libraries and the open literature.

Methods

Members of a new category of selenophosphorus compounds were prepared via microsynthetic protocols and their fragmentation pathways were investigated using electron ionization (EI) and positive electrospray ionization (ESI) mass spectrometry. The EI and ESI fragmentation pathways were suggested and supported by acquired fragment ions of deuterated analogs and density functional theory calculations.

Results

Mass spectrometric investigations showed some interesting fragmentation pathways, such as McLafferty‐type, selenono–selenolo rearrangements, intramolecular electrophilic aromatic substitution reaction and α‐cleavage.

Conclusions

Efficient microsynthesis was conducted, and EI‐MS spectra and ESI‐MS/MS spectra of a series of selenophosphorus compounds were collected and studied with the purpose of identifying CWC‐related chemicals during on‐site inspection and/or off‐site analysis.
DNA Origami Frameworks Enabled Self‐Protective siRNA Delivery for Dual Enhancement of Chemo‐Photothermal Combination Therapy
Authors: Xu Tingting , Yu Sha , Sun Yao , Wu Shaojun , Gao Di , Wang Mingyang , Wang Zhenzhen , Tian Ye , Min Qianhao , Zhu Jun‐Jie
Published: October 2021

Although chemotherapy and photothermal therapy are widely used to combat cancer, their efficacy is often limited by multidrug resistance. Small interfering RNAs (siRNAs) have ability to suppress the expression of target genes, which has been extensively employed for combating the multidrug resistance to chemodrugs and hyperthermia in cancer therapy. However, efficient delivery of siRNAs along with chemo‐photothermal agents in vivo is still an enormous challenge. Herein, octahedral DNA origami frameworks (OctDOFs) are constructed as a nanovehicle for precise organization and orchestrated delivery of siRNAs, chemodrugs (doxorubicin, Dox), and photothermal agents (gold nanorods, AuNRs) in combinatorial treatment of cancer. The inner cavity of the rigid OctDOFs structure is able to shield the encapsulated siRNAs during transportation by sterically hindering RNase degradation and protein binding, thus achieving effective downregulation of connective tissue growth factor (CTGF) and heat shock protein 72 (HSP72) for dual sensitization of cancer cells to chemodrugs and hyperthermia. By amplifying chemo‐photothermal therapeutic potency with siRNAs, the proposed OctDOFs exhibited superior cytotoxicity and tumor inhibition efficacy in vitro and in vivo. This nanovehicle creates a promising siRNA delivery platform for precise medication and combination therapy.
Nanospatial Charge Modulation of Monodispersed Polymeric Microsphere Photocatalysts for Exceptional Hydrogen Peroxide Production
Authors: Tian Qiang , Jing Lingyan , Ye Sheng , Liu Junxue , Chen Ruotian , Price Cameron‐Alexander Hurd , Fan Fengtao , Liu Jian
Published: October 2021

Photocatalysis offers a sustainable strategy for hydrogen peroxide (H2O2) production, which is an essential oxidant and emerging energy carrier in modern chemical industry. The development of polymer‐based photocatalysts to produce H2O2 has great potential but is limited by lower efficiency due to the limitation of light utilization and the low charge separation efficiency. Herein, a series of monodispersed mesoporous resorcinol‐formaldehyde resin spheres (MRFS) are reported with a rational designed spatial charge distribution, exhibiting wide light absorption with a solar‐to‐chemical conversion (SCC) efficiency of 1.1%. Surface photovoltage microscopy (SPVM) measurements unraveled the charge separation in nanospace with uneven distribution of donor (D) and acceptor (A) sites. A density functional theory (DFT) calculation elucidated the origin of photogenerated electrons and holes. Moreover, MRFS demonstrates photocatalytic water oxidation ability. The findings in this work open a new avenue for the development of porous polymeric photocatalysts toward highly efficient solar energy conversion.
Confidence‐driven weighted retraining for predicting safety‐critical failures in autonomous driving systems
Authors: Stocco Andrea , Tonella Paolo
Published: October 2021

Safe handling of hazardous driving situations is a task of high practical relevance for building reliable and trustworthy cyber‐physical systems such as autonomous driving systems. This task necessitates an accurate prediction system of the vehicle's confidence to prevent potentially harmful system failures on the occurrence of unpredictable conditions that make it less safe to drive. In this paper, we discuss the challenges of adapting a misbehavior predictor with knowledge mined during the execution of the main system. Then, we present a framework for the continual learning of misbehavior predictors, which records in‐field behavioral data to determine what data are appropriate for adaptation. Our framework guides adaptive retraining using a novel combination of in‐field confidence metric selection and reconstruction error‐based weighing. We evaluate our framework to improve a misbehavior predictor from the literature on the Udacity simulator for self‐driving cars. Our results show that our framework can reduce the false positive rate by a large margin and can adapt to nominal behavior drifts while maintaining the original capability to predict failures up to several seconds in advance.
Project Recuerdo: Honoring Latinx Families’ Knowledge Within the School
Authors: Lopez Michelle , Butvilofsky Sandra A. , Le Khanh , Gumina Deena
Published: October 2021

The authors describe a culturally sustaining bilingual family engagement project that draws upon Latinx families’ experiential and cultural wealth and integrates that knowledge within the literacy curriculum of a bilingual fourth grade classroom. Through the use of monthly writing prompts, Project Recuerdo, engages families in sharing stories that demonstrate cultural, linguistic, and historical knowledge with the child, teacher, and wider community. This form of family engagement counters deficit orientations towards diverse families, especially Mexican American families, as problems to fix, and instead honors the wealth of knowledge families have and integrates it within the curriculum. Through the analysis of the bilingual journal entries, related classroom artifacts, and family focal groups, the authors validate the importance of learning with and from diverse families; and detail the process for planning the implementation of the family project. Authors provide suggestions for teacher self‐reflection and possible writing prompts to engage families.
Management of intertarsal septic arthritis in an ostrich (Struthio camelus)
Authors: Peel Melanie J. , Torres Rodrigo S. Garcés , Ivančić Marina , Hernández Benjamín E. Alcántar
Published: October 2021

A 7‐year‐old female ostrich (Struthio camelus) presented with lameness, left intertarsal joint swelling and a healing wound on the caudomedial aspect of the joint. Synovial culture revealed Corynebacterium species and radiographs were consistent with progressive septic arthritis. Multiple treatments were attempted including through‐and‐through joint lavage, intra‐articular antibiotics, caudomedial arthrotomy, and regional limb perfusion in conjunction with systemic antibiotics and analgesia. Euthanasia was ultimately performed due to prolonged recumbency and poor prognosis. This report describes novel therapies and a surgical approach utilized for treatment of intertarsal septic arthritis in an ostrich and exemplifies the poor prognosis described in other species presenting with non‐responsive septic arthritis of critical joints.
Clinical features, imaging characteristics, genetic investigation and histopathologic findings in a Chihuahua dog with Lafora disease
Authors: Menchetti Marika , Antinori Lucia , Serra Giulia Dalla , Bertolini Giovanna , Rosati Marco
Published: October 2021

A nine‐year‐old female spayed Chihuahua dog had developed hypnic jerks and progressive myoclonic seizures three months before presentation. Neurological examination showed mental depression and spontaneous or reflex myoclonus. Magnetic resonance imaging findings were consistent with cerebral cortical atrophy and mild cranio‐cervical junction abnormalities. Genetic testing revealed a homozygous NHCLR1 gene mutation, consistent with Lafora disease. Antiepileptic treatment was unsuccessful. Postmortem brain histopathological examination showed a diffuse combination of perikaryal, axonal and/or dendritic accumulation of periodic acid Schiff‐positive cytoplasmic polyglucosan bodies (Lafora bodies), in particular, in the cerebellar cortex. Lafora disease should be considered in the differential diagnosis of late‐onset myoclonus seizures in Chihuahua dogs. Genetic testing of relatives of affected cases is recommended in order to identify carriers and dogs at the preclinical disease stage, to establish the frequency of the mutation in the Chihuahua population, and ultimately to decrease the frequency of this fatal disease.
How to strike a conformational balance in protein force fields for molecular dynamics simulations?
Authors: Kang Wei , Jiang Fan , Wu Yun‐Dong
Published: October 2021

Molecular dynamics (MD) simulation is a powerful tool for exploring the conformational energy landscape of proteins, and the reliability of MD results is crucially dependent on the underlying force field (FF). An accurate FF capable of producing balanced distributions of diverse conformations at multiple levels has been a long‐sought goal. Towards this, several decades of joint efforts have been made to address FF deficiencies, manifested by conformational biases at different levels (local conformations, secondary structures, and global extendedness of polypeptide chain). We first present the major FF biases, then review the strategies to address them separately. Specifically, both nonresidue‐specific and residue‐specific strategies for torsional parameter optimization have been applied to achieve local conformation and secondary structure balances. Significant improvements can be gained with residue‐specific torsional parameters especially when explicit dihedral couplings are considered. Further, the additional balance between protein–protein and protein–water interactions has been optimized via multiple ways to reproduce the global extendedness of polypeptide chains, especially for unfolded or disordered proteins. This review aims to summarize the most valuable experience and lessons gained from the past, which, we hope, can facilitate further improvements of both classical FFs and more sophisticated models such as polarizable FFs.

This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods

Molecular and Statistical Mechanics > Molecular Mechanics
2d TQFTs and baby universes
Authors: Gardiner John , Megas Stathis
Published: October 2021

Abstract

In this work, we extend the 2d topological gravity model of [1] to have as its bulk action any open/closed TQFT obeying Atiyah’s axioms. The holographic duals of these topological gravity models are ensembles of 1d topological theories with random dimension. Specifically, we find that the TQFT Hilbert space splits into sectors, between which correlators of boundary observables factorize, and that the corresponding sectors of the boundary theory have dimensions independently chosen from different Poisson distributions. As a special case, we study in detail the gravity model built from the bulk action of 2d Dijkgraaf-Witten theory, with or without end-of-the-world branes, and for arbitrary finite group G. The dual of this Dijkgraaf-Witten gravity model can be interpreted as a 1d topological theory whose Hilbert space is a random representation of G and whose aforementioned sectors are labeled by the irreducible representations of G.

These holographic interpretations of our gravity models require projecting out negative-norm states from the baby universe Hilbert space, which in [1] was achieved by the (only seemingly) ad hoc solution of adding a nonlocal boundary term to the bulk action. In order to place their solution in the completely local framework of a TQFT with defects, we couple the boundaries of the gravity model to an auxiliary 2d TQFT in a non-gravitational (i.e. fixed topology) region. In this framework, the difficulty of negative-norm states can be remedied in a local way by the introduction of a defect line between the gravitational and non-gravitational regions. The gravity model is then holographically dual to an ensemble of boundary conditions in an open/closed TQFT without gravity.
Einsatz von Albumin
Authors: Mayerhöfer Timo , Wiedermann Christian J. , Joannidis Michael
Published: October 2021

Die Saline vs. Albumin Fluid Evaluation (SAFE) Studie hat gezeigt, dass der Einsatz von Albumin als Infusionslösung im Bereich der Volumentherapie fast überall sicher ist. Eine Ausnahme stellt hypoonkotisches Albumin beim Schädel-Hirn-Trauma dar. Während für Patientinnen und Patienten mit Leberzirrhose klare Indikationen existieren, fehlen für andere Einsatzgebiete noch große Studien, die einen klinisch relevanten Vorteil jenseits der hämodynamischen Wirksamkeit zweifelsfrei zeigen konnten und damit einen breiteren Einsatz rechtfertigen würden. Bei der „Large-volume“-Parazentese, der spontanen bakteriellen Peritonitis, aber auch beim hepatorenalen Syndrom ist der Einsatz von Albumin aufgrund eines klinischen Benefits in randomisierten kontrollierten Studien klar empfohlen und etabliert. Beim septischen Schock kann ein Einsatz von Albumin in Erwägung gezogen werden, wobei sich zwei große Studien zu dieser Fragestellung in Deutschland und Italien noch in der Rekrutierungsphase befinden. Für viele Einsatzgebiete in der Volumentherapie gilt, dass Albumin vor allem dann eingesetzt werden kann, wenn andere Maßnahmen zur hämodynamischen Stabilisierung bereits ausgeschöpft sind. Das gilt sowohl für die Volumengabe bei Hypovolämie als auch für das konservative Volumenmanagement einschließlich der sog. Deresuscitation-Phase. Inwieweit die Korrektur einer ausgeprägten Hypoalbuminämie durch Gabe von exogenem Albumin auch das schlechtere Outcome solcher Patientinnen und Patienten verbessert, ist ebenfalls Teil laufender Studien. Auf dem Weg zu einem Mehr an individualisierter Therapie kann in Zukunft die Hypoalbuminämie bei Entscheidungen für oder gegen einen Einsatz von intravenösen Albuminlösungen in der Volumentherapie eine wichtige Rolle einnehmen.
The consequences of out-of-hours hip fracture surgery: insights from a retrospective nationwide study
Authors: Forssten Maximilian Peter , Mohammad Ismail Ahmad , Borg Tomas , Cao Yang , Wretenberg Per , Bass Gary Alan , Mohseni Shahin
Published: October 2021

Purpose

The study aimed to investigate the association between out-of-hours surgery and postoperative mortality in hip fracture patients. Furthermore, internal fixation and arthroplasty were compared to determine if a difference could be observed in patients operated with these techniques at different times during the day.

Methods

All patients above 18 of age years in Sweden who underwent hip fracture surgery between 2008 and 2017 were eligible for inclusion. Pathological fractures, non-operatively managed fractures, or cases whose time of surgery was missing were excluded. The cohort was subdivided into on-hour (08:00–17:00) and out-of-hours surgery (17:00–08:00). Poisson regression with adjustments for confounders was used to evaluate the association between out-of-hours surgery and both 30-day and 90-day postoperative mortality.

Results

Out-of-hours surgery was associated with a 5% increase in the risk of both 30-day [adj. IRR (95% CI) 1.05 (1.00–1.10), p = 0.040] and 90-day [adj. IRR (95% CI) 1.05 (1.01–1.09), p = 0.005] mortality after hip fracture surgery compared to on-hour surgery. There was no statistically significant association between out-of-hours surgery and postoperative mortality among patients who received an internal fixation. Arthroplasties performed out-of-hours were associated with a 13% increase in 30-day postoperative mortality [adj. IRR (95% CI) 1.13 (1.04–1.23), p = 0.005] and an 8% increase in 90-day postoperative mortality [adj. IRR (95% CI) 1.08 (1.01–1.15), p = 0.022] compared to on-hour surgery.

Conclusion

Out-of-hours surgical intervention is associated with an increase in both 30- and 90-day postoperative mortality among hip fracture patients who received an arthroplasty, but not among patients who underwent internal fixation.
3D tumor angiogenesis models: recent advances and challenges
Authors: Bhat Sharath M. , Badiger Vaishnavi A. , Vasishta Sampara , Chakraborty Juhi , Prasad Seetharam , Ghosh Sourabh , Joshi Manjunath B.
Published: October 2021

The development of blood vessels, referred to as angiogenesis, is an intricate process regulated spatially and temporally through a delicate balance between the qualitative and quantitative expression of pro and anti-angiogenic molecules. As angiogenesis is a prerequisite for solid tumors to grow and metastasize, a variety of tumor angiogenesis models have been formulated to better understand the underlying mechanisms and associated clinical applications. Studies have demonstrated independent mechanisms inducing angiogenesis in tumors such as (a) HIF-1/VEGF mediated paracrine interactions between a cancer cell and endothelial cells, (b) recruitment of progenitor endothelial cells, and (c) vasculogenic mimicry. Moreover, single-cell sequencing technologies have indicated endothelial cell heterogeneity among organ systems including tumor tissues. However, existing angiogenesis models often rely upon normal endothelial cells which significantly differ from tumor endothelial cells exhibiting distinct (epi)genetic and metabolic signatures. Besides, the existence of intra-individual variations necessitates the development of improved tumor vascular model systems for personalized medicine. In the present review, we summarize recent advancements of 3D tumor vascular model systems which include (a) tissue engineering-based tumor models; (b) vascular organoid models, and (c) organ-on-chips and their importance in replicating the tumor angiogenesis along with the associated challenges to design improved models.
Seasonal variations in the synoptic climatology of air pollution in Birmingham, UK
Authors: Hodgson Edward C. , Phillips Ian D.
Published: October 2021

A synoptic typing approach was undertaken to examine the seasonal relationship (winter versus summer) between air mass types and pollutant concentrations of O3, PM10, NOx, NO2 and CO in Birmingham, UK, from 2000 to 2015. Daily means of seven surface meteorological variables were entered into a P-mode principal component analysis. Three principal components explained 72.2% (72.9%) of the variance in winter (summer). Cluster analysis was used to group together days with similar PC scores and thus similar meteorological conditions. Six clusters provided the best air mass classification in both seasons. High pollutant concentrations were associated with anticyclonic types. In particular, tropical (polar) continental air mass type was most likely to produce extremely high concentrations in summer (winter). In winter, a sequence of Polar Continental (cool and humid) and Binary Mid-latitude Anticyclonic Maritime—Sub-Polar Cyclonic Maritime (cold and dry) induced severe pollution episodes in all pollutants. Whilst the mean duration of severe pollution episodes varied little between winter and summer (O3 was an exception, with severe episodes lasting 20% longer in summer), high pollutant extremes were more common in winter. This was due to more favourable meteorological conditions (e.g. temperature inversions) and increased anthropogenic emissions during the cold season.
Geophysical methods help to assess potential groundwater extraction sites
Authors: Wiederhold Helga , Kallesøe Anders Juhl , Kirsch Reinhard , Mecking Rebekka , Pechnig Renate , Skowronek Frank
Published: October 2021

Complex geology in glacial terrain makes groundwater exploration challenging for water supply companies. Abrupt lateral changes of geological conditions, for example, raise the risk of unsuccessful exploration drilling. At some locations, local water supply companies experience a large number of dry wells, raising the need for better exploration approaches. The use of geophysical techniques enables the detection and characterization of subsurface structures in terms of aquifers and aquitards.

We present two examples in which seismic and resistivity methods are combined for subsurface characterization. A thrust structure is detected in the Varde study area in Denmark and a channel structure is mapped in the Hamburg-Sülldorf study area in Germany. The different imaging characteristics of seismic P‑ and S‑waves are demonstrated. The combination of seismic and resistivity methods enables delineating groundwater-bearing and groundwater-barrier layers down to a depth of 150 m.
The impact of the COVID-19 pandemic on global neurosurgical education: a systematic review
Authors: Jain Raunak , Carneiro Raquel Alencastro Veiga Domingues , Vasilica Anca-Mihaela , Chia Wen Li , de Souza Abner Lucas Balduino , Wellington Jack , Kumar Niraj S.
Published: October 2021

The COVID-19 pandemic has disrupted neurosurgical training worldwide, with the shutdown of academic institutions and the reduction of elective surgical procedures. This impact has disproportionately affected LMICs (lower- and/or middle-income countries), already burdened by a lack of neurosurgical resources. Thus, a systematic review was conducted to examine these challenges and innovations developed to adapt effective teaching and learning for medical students and neurosurgical trainees. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and The Cochrane Handbook of Systematic Reviews of Interventions. MEDLINE, PubMed, Embase and Cochrane databases were accessed, searching and screening literature from December 2019 to 5th December 2020 with set inclusion and exclusion criteria. Screening identified 1254 articles of which 26 were included, providing data from 96 countries. Twenty-three studies reported transition to online learning, with 8 studies also mentioned redeployment into COVID wards with 2 studies mentioning missed surgical exposure as a consequence. Of 7 studies conducted in LMICs, 3 reported residents suffering financial insecurities from reduced surgical caseload and recession. Significant global disruption in neurosurgical teaching and training has arisen from the COVID-19 pandemic. Decreased surgical exposure has negatively impacted educational provision. However, advancements in virtual technology have allowed for more affordable, accessible training especially in LMICs. Using this, initiatives to reduce physical and mental stress experienced by trainees should be paramount.
Macroinvertebrate species occupancy frequency distribution patterns in eutrophic lakes
Authors: Suhonen Jukka , Paasivirta Lauri , Rantala Markus J. , Jukka Salmela , Suutari Erna
Published: October 2021

Metacommunity models describe species occupancy frequency distribution (hereinafter ‘SOFD’). Our goal is to present how the differences in eight macroinvertebrate orders dispersal ability affect SOFD patterns. A total of 293 species from eight macroinvertebrate orders were observed in 14 eutrophic lakes in southern Finland. Species occupancy ranged from 1 to 14. About 30% (89 out of 293) of the species were found in only one lake, yielding a surprisingly high number of rare species. So, there were few widely distributed common species and numerous rare species with a restricted distribution. Combined data from eight macroinvertebrate orders supported the bimodal truncated SOFD pattern. Similarly, the low dispersal ability orders, watermites and mayflies, fitted the bimodal truncated SOFD pattern. However, bimodal symmetric SOFD pattern also fitted relatively well to the dragonflies and damselflies with high dispersal ability. It seems that differences in dispersal ability among different macroinvertebrate orders may partly explain observed differences. Moreover, our results supported slightly more a niche-based model rather than a metapopulation dynamics model in eutrophic lakes littoral macroinvertebrate metacommunities. Our results highlight that the dispersal ability is important trait for species conservation in patchily distributed habitat.
Assemblages of Acari in shallow burials: mites as markers of the burial environment, of the stage of decay and of body-cadaver regions
Authors: Rai Jas K. , Pickles Brian J. , Perotti M. Alejandra
Published: October 2021

The burial of a cadaver results in reduced arthropod activity and disruptions in colonisation patterns. Here, the distribution and diversity of mite taxa was studied across decomposition stages of shallowly buried pig carcasses (Sus scrofa domesticus). In total 300 mites (88 species) were collected from three pig shallow graves compared to 129 mites (46 species) from control (bare) soil samples at the same depth. A successional pattern of Acari higher taxa and families was observed, and species richness and biodiversity fluctuated throughout decomposition, whereas active decay showed the greatest biodiversity. Mesostigmata mites were the most abundant in ‘cadaver soils’ with a significant difference in the abundance of Parasitidae mites, whereas Oribatida mites (true soil mites) were the most abundant in control soils. Certain mite species were significantly associated with decay stages:Cornigamasus lunariswith ‘bloated’,Gamasodes spinigerwith ‘active’,Eugamasussp. andLorryia reticulatawith ‘advanced’, andMacrocheles matriusandRamusella clavipectinatain ‘dry’.Scheloribates laevigatuswas a marker of bare soil at a shallow depth andVulgoramasus rembertiof buried decomposition, not specific to any decay stage. Analysis of mite assemblages associated with head, torso and posterior body showed thatParasitus evertsiandM.matriusare attracted to beneath the thighs, whereasL.reticulatato beneath the head. This study highlights the value of mites as indicator species of decomposition and its stages, confirming (1) a succession of Acari on buried remains and (2) species specificity to body regions.
A different approach to fixed-time stability for a wide class of time-varying neural networks
Authors: Matusik Radosław
Published: October 2021

We present sufficient conditions for fixed-time stability for a wide class of neural networks described by a system of differential equations with right-hand side satisfying the Carathéodory conditions. In contrast to the results given in the literature, where the settling-time function is estimated by an unknown Lyapunov function, we estimate the settling-time by a known function. In addition, the settling-time function does not depend on the initial values. We also give numerical examples, which confirm the theoretical results.