bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximal Lactate Accumulation Rate in All-out Exercise Differs between Cycling and Running
Authors: Quittmann Oliver Jan , Schwarz Yannick Max , Mester Jonas , Foitschik Tina , Abel Thomas , Strüder Heiko Klaus
Published: November 2020

This study aims to compare maximal lactate accumulation rate (V̇ Lamax) and power output (Pmax) between cycling and running in terms of reliability, differences between, and correlations among modalities. Eighteen competitive triathletes performed a 15-s all-out exercise test in cycling and a 100-m sprint test in running. Each test was performed twice and separated by one week. Exercise tests in cycling were performed on an ergometer whereas sprint tests in running were performed on an indoor track. Differences between trials and exercise modality were analyzed using two-way ANOVA. V̇ Lamax (ICC=0.894, ICC=0.868) and Pmax (ICC=0.907, ICC=0.965) attained ‘good’ to ‘excellent’ reliability in both cycling and running, respectively. V̇ Lamax was higher in running (d=0.709, p=0.016) whereas Pmax was lower in running (d=−0.862, p < 0.001). For V̇ Lamax, limits of agreement between modalities ranged from −0.224 to +0.437 mmol·l-1·s-1. Pmax correlated between modalities (r=0.811, p < 0.001), whereas no correlation was found in V̇ Lamax (r=0.418, p=0.084). V̇ Lamax is highly reliable in both modalities and higher in running compared to cycling. Since V̇ Lamax does not correlate between cycling and running, it should be determined sport-specifically.
miR-381 Targets KCTD15 to Regulate Bovine Preadipocyte Differentiation In Vitro
Authors: Xu Hongyan , Shao Jing , Fang Jiachen , Yin Baozhen , Zhang Luomeng , Zhang Jiasu , Xia Guangjun
Published: November 2020

MicroRNAs (miRNAs) are small, single-stranded, noncoding RNAs ~21 to ~23 nucleotides in length and have become a popular research topic in recent years due to their regulation of gene expression and many physiological processes, including fat metabolism; however, the precise functional mechanisms underlying their regulation of fat metabolism are not fully understood. Here, we identified miR-381, which specifically targets the 3′ untranslated region (3′ UTR) of potassium channel tetramerization-domain-containing 15 (KCTD15) , and verified the mechanism regulating its expression and participation in adipogenesis. We used a dual luciferase-reporter assay and transfection-mediated miR-381 overexpression and inhibition in Yanbian yellow cattle preadipocytes to investigate the role of miR-381 in adipogenesis. The results showed that miR-381 directly targets the 3′ UTR of KCTD15 and downregulates its expression. Additionally, miR-381 overexpression using an miRNA mimic promoted triglyceride accumulation and upregulated adipogenic peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer-binding protein α (C/EBPα) at both the protein and mRNA levels, whereas miR-381 inhibition produced the opposite effect. These results indicated that miR-381 regulates the differentiation of Yanbian yellow cattle preadipocytes by inhibiting KCTD15 expression, thereby highlighting the importance of miRNA-mediated regulation of adipogenesis. Furthermore, our findings suggested that miR-381 and its target gene(s) might represent new targets for investigating intramuscular fat deposits in cattle and treating human obesity.
Continuous-Flow Reactions Mediated by Main Group Organometallics
Authors: Knochel Paul , Harenberg Johannes H. , Weidmann Niels
Published: November 2020

The generation of reactive organometallic reagents in batch is often complicated by the low thermal stability of these important synthetic intermediates and can require low reaction temperatures and special reaction conditions. However, the use of continuous-flow setups and microreactors has led to a revolution in this field. In this short review, an overview is given of recent advances in this area, with a focus on the main group organometallics of Li, Na, and K.
Access to α,α-Difluoro-γ-amino Acids by Nickel-Catalyzed Reductive Aryldifluoroacetylation of N-Vinylacetamide
Authors: Zhang Xingang , Zhao Qing-Wei , Yang Zhi-Fang , Fu Xia-Ping
Published: November 2020

A nickel-catalyzed reductive aryldifluoroacetylation of N-vinylacetamide with ethyl chloro(difluoro)acetate and aryl iodides is described. This chelating amide carbonyl group-assisted strategy provides rapid access to a variety of protected α,α-difluoro-γ-amino acids that might have potential applications in peptide chemistry and protein engineering. An advantage of this method is its synthetic simplicity, with no preparation of organometallic reagents.
Designing Rh(I)-Half-Sandwich Catalysts for Alkyne [2+2+2] Cycloadditions
Authors: Orian Laura , Bickelhaupt F. Matthias
Published: November 2020

Metal-mediated [2+2+2] cycloadditions of unsaturated molecules to cyclic and polycyclic organic compounds are a versatile synthetic route affording good yields and selectivity under mild conditions. In the last two decades, in silico investigations have unveiled important details about the mechanism and the energetics of the whole catalytic cycle. Particularly, a number of computational studies address the topic of half-sandwich catalysts which, due to their structural fluxionality, have been widely employed, since the 1980s. In these organometallic species, the metal is coordinated to an aromatic ring, typically the ubiquitous cyclopentadienyl anion, C5H5
–(Cp) or to the Cp moiety of a larger polycyclic aromatic ligand (Cp′). During the catalytic process, the metal continuously ‘slips’ on the ring, changing its hapticity. This phenomenon of metal slippage and its implications for the catalyst’s performance are discussed in this work, referring to the most important computational mechanistic studies reported in literature for Rh(I) half-metallocenes, with the purpose of providing hints for a rational design of this class of compounds.

1 Introduction

2 Mechanism of Metal-Catalyzed Acetylene [2+2+2] Cycloaddition to Benzene and the Problem of the Indenyl Effect

2.1 Acetylene-Acetonitrile [2+2+2] Co-cycloaddition to 2-Methylpyridine: Evidence of the Indenyl Effect

2.2 Heteroaromatic Catalysts and the Evidence of a Reverse Indenyl Effect

2.3 Booth’s Mechanistic Hypothesis and the Evidence of the Indenyl Effect

3 Structure–Reactivity Correlation: The Slippage-Span Model

4 Conclusions and Perspectives
Accelerating Heat-Initiated Radical Reactions of Organic Halides with Tin Hydride Using Flow Microreactor Technologies
Authors: Nagaki Aiichiro , Jiang Yiyuan , Ashikari Yosuke , Guan Kaiteng
Published: November 2020

We herein report that flow microreactors can promote an efficiency of radical chain reactions. The chain reactions with a fast propagation step can be accelerated by virtue of an efficient heat-transfer character of the microreactors, whereas the yield of those reactions with a slow propagation step was increased by flow microreactors. Moreover, the yield was further increased by a sequential addition of the initiators, which was allowed by a flow-sequential-addition system.
Recent Advances in Organic Synthesis Based on N,N-Dimethyl Enaminones
Authors: Yu Fuchao , Huang Jiuzhong
Published: November 2020

Enaminones are gaining increasing interest because of their unique properties and their importance in organic synthesis as versatile building blocks. N,N-Dimethyl enaminones offer a better leaving group (a dimethylamine group) than other enaminones, and allow further elaboration via a range of facile chemical transformations. Over the past five years, there have been an increasing number of reports describing the synthetic applications of N,N-dimethyl enaminones. This review provides a comprehensive overview on the synthetic applications of N,N-dimethyl enaminones that have been reported since 2016.

1 Introduction

2 Direct C(sp2)–H α-Functionalization

2.1 Synthesis of α-Sulfenylated N,N-Dimethyl Enaminones

2.2 Synthesis of α-Thiocyanated N,N-Dimethyl Enaminones

2.3 Synthesis of α-Acyloxylated N,N-Dimethyl Enaminones

3 Functionalization Reactions via C=C Double Bond Cleavage

3.1 Synthesis of Functionalized Methyl Ketones

3.2 Synthesis of α-Ketoamides, α-Ketoesters and 1,2-Diketones

3.3 Synthesis of N-Sulfonyl Amidines

4 Construction of All-Carbon Aromatic Scaffolds

4.1 Synthesis of Benzaldehydes

4.2 Synthesis of the Naphthalenes

5 Construction of Heterocyclic Scaffolds

5.1 Synthesis of Five-Membered Heterocycles

5.2 Synthesis of Six-Membered Heterocycles

5.3 Synthesis of Quinolines

5.4 Synthesis of Functionalized Chromones

5.5 Synthesis of Other Fused Polycyclic Heterocycles

6 Conclusions and Perspectives
Reconstrução combinada do ligamento cruzado Anterior e lesão do ligamento anterolateral comparada àreconstrução isolada do ligamento cruzado anterior: Uma metanálise
Authors: Bucar Augusto Leão , Pires Rodrigo Nunes de Albuquerque , Silva Rodrigo do Carmo , Araujo Edicarlos André Cavalcante de , da Silva Messias Froes , de Araujo Pedro Henrique Nunes
Published: November 2020

O objetivo da presentepesquisa é comparar, por meio de uma metanálise, os resultados da reconstrução combinada do ligamento cruzado anterior (LCA) e do ligamento anterolateral (LLA), comparado com a reconstrução isolada padrão, em pacientes com lesão crônica do ligamento cruzado anterior. Buscando alcançar o objetivo da pesquisa, foi realizada uma meta-análise para determinar se a combinação da reconstrução combinada LCA e LLA levaria àmelhoria significativa da função do joelho, medida pelos escores de avaliação International Knee Documentation Committee (IKDC), Lysholm, KT-2000 e menor taxa de ruptura do enxerto, em comparação com a reconstrução isolada. Para identificar ensaios clínicos randomizados (ECR) comparando a reconstrução combinada do LCA e LLA com a reconstrução isolada do LCA, foram pesquisados artigos publicados entre 2010 e 2019 nas bases MEDLINE, EMBASE, SPORTDiscus, LILACS e Cochrane Central RegisterofControlledTrials e seguiram os critérios de Itens de Relatórios Preferidos para Revisões Sistemáticas e Metanálises (PRISMA). A estabilidade da articulação do joelho é apenas marginalmente aprimorada com a reconstrução combinada de LCA e LLA, e ambas as técnicas de reconstrução mostram resultados funcionais. Os principais desfechos procurados foram a função do paciente e as taxas de estabilidade e ruptura do enxerto após a reconstrução do LCA. Dos 421 estudos identificados, 6estudos foram incluídos em nossa meta-análise. A qualidade do estudo (validade interna) foi avaliada usando o instrumento Cochrane risco-de-viés; em geral, foi encontrada uma qualidade moderada de evidências dos estudos incluídos. Os pacientes submetidos à reconstrução isolada do LCA mostraram maior taxa de ruptura do enxerto (RR 0,22; índice de confiança [IC]95%: 0,12–0,41; p< 0,00001).
Atualização em instabilidade patelar
Authors: Severino Nilson Roberto , Severino Fabrício Roberto , de Camargo Osmar Pedro Arbix , Guglielmetti Luiz Gabriel Betoni , de Oliveira Victor Marques , Cury Ricardo de Paula Leite
Published: November 2020

A instabilidade patelar é uma condição clínica multifatorial, que acomete um número expressivo de pacientes, ocorrendo devido a variações anatômicas, morfológicas da articulação e do alinhamento patelofemoral. O presente estudo de revisão e atualização da literatura teve como objetivos identificar e sumarizar os conceitos atuais sobre instabilidade patelar em relação aos fatores de risco associados, os critérios diagnósticos e os benefícios e riscos dos tratamentos conservador e cirúrgico. Para tanto, foi realizado um levantamento nas bases de dados eletrônicas MEDLINE (via Pubmed), LILACS e Cochrane Library. Conclui-se que o diagnóstico preciso depende da avaliação clínica detalhada, incluindo o histórico e possíveis fatores de risco individuais, além de exames de imagem. O tratamento inicial da instabilidade patelar é ainda controverso, e requer a combinação de intervenções conservadoras e cirúrgicas, levando em consideração tanto os tecidos moles quanto as estruturas ósseas, sendo estas últimas a razão mais comum para a escolha do tratamento cirúrgico, principalmente instabilidade patelar lateral.
Hemopatch to Fix Mobile Lobe after Thoracoscopic Lobectomy
Authors: Fiorelli Alfonso , Carlucci Annalisa , Cascone Roberto , Santini Mario
Published: November 2020

Herein, we report a new technique of middle lobe fixation using Hemopatch after thoracoscopic right upper lobectomy. A 3–0 atraumatic polypropylene suture is passed first through the Hemopatch, then two not-inflated lobes, and then again patch. The lung is half-inflated, and the Hemopatch is placed onto the surface of the two half-inflated lobes in a bridging manner over the fissure. The suture is then tied by a clip. This procedure was successfully applied in five consecutive patients after thoracoscopic right upper lobectomy for cancer. No complications occurred during and after operation.
Surgical Management of Recurrent Uncomplicated Diverticulitis
Authors: Rai Vinay , Mishra Nitin
Published: November 2020

Sigmoid diverticulitis represents a most common gastroenterological diagnosis in the western world. There has been a significant change in the management of recurrent uncomplicated diverticulitis in the last 10 to 15 years. The absolute number of previous episodes is not used as criteria to recommend surgery anymore. Young age is no longer considered to be an indication for more aggressive surgical treatment. It is accepted that subsequent episodes of diverticulitis are not significantly worse than the first episode. Laparoscopic surgery is now the standard of care for elective surgery for diverticulitis where expertise is available. There is a consensus that decision to perform sigmoid colectomy should be individualized, after careful risk benefit assessment.
Tratamento não operatório de fraturas desviadas da extremidade proximal do úmero em idosos: Correlação entre os desvios e os resultados clínicos
Authors: Gracitelli Mauro Emilio Conforto , Yamamoto Gustavo Jum , Malavolta Eduardo Angeli , Andrade-Silva Fernando Brandão , Kojima Kodi Edson , Ferreira Neto Arnaldo Amado
Published: November 2020

Objetivos Descrever o resultado funcional do tratamento não operatório de fraturas desviadas da extremidade proximal do úmero (FEPU) pela escala da American Shoulder and Elbow Surgeons (ASES, na sigla em inglês) após 12 meses e avaliar se as diferentes classificações e medidas radiográficas iniciais têm correlação com os resultados clínicos.

Métodos Foram avaliados em tempos padronizados (3, 6 e 12 meses), 40 pacientes > 60 anos com FEPU submetidos ao tratamento não operatório. Foram utilizadas as escalas da ASES, Constant-Murley e Single Assessment Numeric Evaluation (SANE, na sigla em inglês). As variáveis radiográficas incluíram as classificações de Neer e Resch, a presença de fratura e desvio dos tubérculos, cominuição metafisária, lesão periosteal medial, desvios angulares e translacionais da cabeça no plano coronal e sagital e desvio dos tubérculos.

Resultados Observamos resultados pela escala de ASES de 77,7 ± 23,2 para toda a amostra, pela de Constant-Murley de 68,7 ± 16 e de 82,6% para a escala em relação ao lado contralateral. A escala de SANE aos 12 meses foi de 84,8 ± 19. Os critérios radiográficos que apresentaram influência negativa no resultado clínico pela escala de ASES aos 12 meses foram a gravidade pela classificação de Neer e pelo desvio angular no plano coronal (mensurado pelo ângulo cabeça-diáfise) e a presença de fratura dos tubérculos.

Conclusão O tratamento não operatório de fraturas desviadas da extremidade proximal do úmero em pacientes idosos resulta em bons resultados clínicos. Os resultados clínicos são influenciados negativamente pelo desvio angular da cabeça do úmero e pela presença de fratura dos tubérculos maior e menor, assim como pela classificação de Neer.
Thyroid Functions in Children on Levetiracetam or Valproic Acid Therapy
Authors: Karatoprak Elif , Paksoy Samet
Published: November 2020

The aim of this study was to investigate the thyroid functions in children receiving levetiracetam or valproate monotherapy. We retrospectively reviewed the records of children with controlled epilepsy receiving valproic acid (VPA group) or levetiracetam monotherapy (LEV group) for at least 6 months. Free thyroxine 4 levels (fT4) and thyroid stimulating hormone (TSH) levels were compared between VPA group, LEV group, and age- and gender-matched healthy children (control group). A total of 190 children were included in the study: 63 were in the VPA, 60 in the LEV, and 67 in the control group. Although there was no significant difference regarding average fT4 levels, higher TSH levels were found in the VPA group when compared with the LEV and control groups (p < 0.001 and p < 0.001, respectively). There was no significant difference in terms of fT4 and TSH values in the LEV group when compared with the control group (p = 0.56 and p = 0.61, respectively). Subclinical hypothyroidism (defined as a TSH level above 5 uIU/mL with a normal fT4 level was detected in 16% of patients in the VPA group, none in the LEV and control groups. Our study found that VPA therapy is associated with an increased risk of subclinical hypothyroidism while LEV had no effect on thyroid function tests.
Reconstruction of Extensive Composite Parotid Region Oncologic Defects with Immediate Facial Nerve Reconstruction Using a Chimeric Scapulodorsal Vascularized Nerve Free Flap
Authors: Mangialardi Maria L. , Honart Jean-Fracois , Qassemyar Quentin , Guyon Alice , Li Sean S. , Benmoussa Nadia , Beldarida Vincent , Temam Stéphane , Kolb Frédéric
Published: November 2020

Background Cancer involving the parotid gland region may originates from parotid parenchyma itself or from locoregional organs and in rare cases, the facial nerve (FN) has to be sacrificed during tumor resection. In these cases, cancer extension often goes beyond the parotid compartment and requires extensive local resection responsible for complex multitissular defects. The goals of reconstruction may be summarized in the following two components: (1) restoration of the volumetric tissue defect and (2) FN reconstruction. The aim of this study is to describe our surgical technique and our cosmetic results using the chimeric scapulodorsal vascularized nerve (SDVN) flap to reconstruct extensive maxillofacial defects associated with FN sacrifice.

Methods All patients undergone an extensive maxillofacial resection with FN sacrifice and primarily reconstructed with a SDVN flap were included. We classified the maxillofacial defects into six groups based on the type of resection. Intraoperative data including flap composition, topography of FN injury, length of nerve gap, and number of nervous anastomosis were recorded.

Results Twenty-nine patients were included. Mean follow-up was 38.7 months. The harvested flaps included the SDVN combined with different components according to the defect group. A satisfactory volumetric restoration was obtained in 93% of cases. The mean number of distal nervous anastomosis was 4.5. The length of the vascularized grafted nerve ranged from 7 to 10 cm.

Conclusion This is largest series presented in literature on primary FN reconstruction utilizing a vascularized nerve graft. We believe that the chimeric SDVN flap should be highly considered for these cases due to its versatility. The surgeon is able to use single donor site available soft and hard tissues components along with a vascular motor nerve graft, which offers a great length and number of distal branches, and easily matches with the extracranial FN trunk and its peripheral ramifications.
Elderly consumers and financial choices: A systematic review
Authors: Guido Gianluigi , Amatulli Cesare , Sestino Andrea
Published: November 2020

The purpose of this paper is to investigate elderly choices and behaviors in financial services markets. A systematic review of a five-decade period (1970–2019) of academic research in the marketing field was carried out in order to identify elderly consumers’ decisions regarding financial asset management and legacy, highlighting the main findings of extant research and practical implications for marketers. Results shed light on financial asset management in terms of welfare, retirement planning, and investments for old age, as well as legacy practices in terms of special possessions, charities, and rites of passage. The study underlines the need to consider the heterogeneous nature of elderly consumers’ values and lifestyles in designing strategies for financial services and products, emphasizing that demographic differences alone are not adequate to effectively define market segments. Furthermore, the role of mixed marketing approaches considering elderly choices are discussed, together with implications for companies that want to target such consumer target.
Bulk modulus measurement at mHz frequencies and high-pressure using synchrotron x-ray radiation
Authors: Li L. , Weidner D. J. , Chen Haiyan , Triplett Richard
Published: November 2020

We report an experimental protocol for measuring the frequency dependence of the bulk modulus carried out in a synchrotron x-ray facility based multi-anvil high-pressure apparatus. An oscillating pressure perturbation characterized by x-ray diffraction produces a volume strain measured by imaging. Together, these yield the bulk modulus of the sample. Here, we report data at 3 mHz as an example of the possibility of providing these data for the frequency range of 1 mHz–100 mHz.
Magnetically mediated thermoacoustic imaging with single coil based on non-uniform magnetic field excitation
Authors: Li Yanhong , Liu Guoqiang , Song Jiaxiang
Published: November 2020

In order to eliminate the limitation caused by the use of a uniform magnetic field mode in magnetically mediated thermoacoustic imaging (MM-TAI), non-uniform magnetic field excitation with a single coil for MM-TAI is proposed in this paper. The theoretical model of the electromagnetic field based on time–space separation and acoustic field problems for MM-TAI is solved. For the inverse problem, the heat absorption distribution is reconstructed by the time reversal technique. The reconstructed results are in good accord with the original structure model, and the image can be clearly identified and agree well with the electric conductivity model. The experimental system is optimized to test the method, then the phantoms with conductivities of 8 S/m and 7 S/m are used for thermoacoustic signal detection and imaging. The signal detecting ability of the low conductivity target has improved significantly. These results provide the basis of MM-TAI for further application in biomedical imaging.
Experimental and simulation analysis of dielectric barrier discharge based pulsed cold atmospheric pressure plasma jet
Authors: Sharma Navin Kumar , Misra Shikha , Varun  , Pal Udit Narayan
Published: November 2020

In this paper, experimental and simulation investigations have been carried out for the characterization of the dielectric barrier discharge based cold atmospheric pressure plasma jet (C-APPJ) for a unique geometry in which argon gas is used at different flow rates along with pulsed DC supply at different frequencies. A tapered structure has been fabricated for acquiring sufficient velocity of the gas at a low flow rate. The typical V–I characteristic of the C-APPJ has been presented for a wide range of flow rates (1–5 SLM) and frequencies (10–25 kHz). On increasing the gas flow rate and frequency, discharge sustains for the lower potential of 5 kV and requires low power. It has been observed that the power dissipation for the formation of the plasma jet increases on increasing frequency at a constant flow rate. Also, the analysis of discharge current is presented for each combination of the flow rate and operating frequencies. Furthermore, the investigation has been carried out for the analysis of electron density, velocity distribution of gas, and distribution of the electric field in the C-APPJ for the same experimental geometry through the simulation tool COMSOL Multiphysics. The maximum electric field of 3.22×106 V/m and the maximum electron density of 3.38×1019 1/m3 have been observed during the propagation of the plasma jet at 1 SLM flow rate. Such qualitative analysis of jet formation along the electric field distribution in a wide range of operating parameters would certainly be helpful in the development of dielectric barrier discharge based C-APPJ sources suitable for the biomedical and food related applications.
Modeling on the dynamic mechanical response of single-crystalline Ni–Mn–Ga alloys based on Hamilton’s principle
Authors: Wang Jiong , Fan Chengkai
Published: November 2020

In this paper, a variational approach is proposed to study the dynamic mechanical response of a single-crystalline Ni–Mn–Ga sample. First, some constitutive assumptions are adopted to describe the material properties of single-crystalline Ni–Mn–Ga alloys. Hamilton’s action integral is then formulated for the mechanical system being studied, which depends on the position vector field and the variant state distribution in the sample. By calculating the variation of the action integral with respect to the position vector field, the equation of motion, as well as the boundary condition and the twin interface connection condition, can be obtained. By further calculating the variation of the action integral with respect to the variant state distribution (through twin interface movements), the expression of the driving force on the twin interfaces is derived, based on which the twin interface movement criterion is established. Combining the equation of motion and the twin interface movement criterion, the governing system for modeling the dynamic response of the single-crystalline Ni–Mn–Ga sample can be formulated. To show the validity of the governing system, a simple example is studied and some analytical results are constructed. Especially, the relation between the external mechanical load and the twin interface velocity is revealed, which is consistent with the experimental observations.
Computationally efficient approach for the identification of ice-binding surfaces and how they bind ice
Authors: Naullage Pavithra M. , Metya Atanu K. , Molinero Valeria
Published: November 2020

Recognition and binding of ice by proteins, crystals, and other surfaces is key for their control of the nucleation and growth of ice. Docking is the state-of-the-art computational method to identify ice-binding surfaces (IBS). However, docking methods require a priori knowledge of the ice plane to which the molecules bind and either neglect the competition of ice and water for the IBS or are computationally expensive. Here we present and validate a robust methodology for the identification of the IBS of molecules and crystals that is easy to implement and a hundred times computationally more efficient than the most advanced ice-docking approaches. The methodology is based on biased sampling with an order parameter that drives the formation of ice. We validate the method using all-atom and coarse-grained models of organic crystals and proteins. To our knowledge, this approach is the first to simultaneously identify the ice-binding surface as well as the plane of ice to which it binds, without the use of structure search algorithms. We show that biased simulations even identify surfaces that are too small or too weak to heterogeneously nucleate ice. The biasing simulations can be used to identify of IBS of antifreeze and ice nucleating proteins and to equilibrate ice seeds bound to an IBS for the calculation of heterogeneous ice nucleation rates using classical nucleation theory.
Mechanical drift modeling and analysis of V-shaped linear ultrasonic motors with a flexible clamp
Authors: Geng Ranran , Cui Song , Huang Jiacai , Bian Rong
Published: November 2020

The flexible clamp used in linear ultrasonic motors (LUMs) not only supports the motor but also simplifies the structure and improves the vibration characteristics. However, the flexible clamp causes the mechanical drift phenomenon, leading to a reduction in positional accuracy. To solve this problem, the mechanical drift mechanism and the control methods of V-shaped LUMs are investigated in this work. First, a mechanical model of the stator of a LUM with a flexible clamp is established to analyze the reason for the mechanical drift. Then, based on the mechanical model, the rules of the appearance of mechanical drift in clamping components with different stiffnesses and shapes are studied. The results indicate that mechanical drift is obvious when the stiffnesses of the two flexible clamps are different, whereas it hardly occurs when clamping components with tremendous tangential stiffnesses are used. Finally, two new types of V-shaped LUM stators that have a flexible clamp on one side and an analogous straight-beam clamp on the other side are proposed. Experiments were conducted to validate the mechanical model analysis and the clamp drift findings, and the results demonstrate that the novel motors have little mechanical drift and stable running characteristics and can be used in precision motion platforms.
Dynamic mechanical characterization of two-photon-polymerized SZ2080 photoresist
Authors: Pertoldi L. , Zega V. , Comi C. , Osellame R.
Published: November 2020

Two-photon polymerization (2PP) is a material processing technique employed for the production of high-resolution microstructures. The high potential of this technique in the fabrication of structured materials, or metamaterials, has recently attracted significant research interest. To proceed toward real applications, the mechanical properties of the material obtained by 2PP should be known. These properties depend on all the process parameters, which affect the cross-linking between the polymeric chains, and very few results are available in the literature. In this work, we perform a systematic characterization of the elastic properties of femtosecond laser-polymerized SZ2080 (hybrid organic–inorganic photoresist) by combining dynamic experimental tests and numerical simulations on properly designed microstructures. Studying the resonance frequencies of micro-cantilevers, we demonstrate the possibility of tailoring the mechanical properties of the material by changing the laser irradiation conditions. This result paves the way to the use of 2PP for the fabrication of microdevices operating in a dynamic regime with optimized material properties.
Effect of radiation on thermosolutal Marangoni convection in a porous medium with chemical reaction and heat source/sink
Authors: Mahabaleshwar U. S. , Nagaraju K. R. , Vinay Kumar P. N. , Azese Martin Ndi
Published: November 2020

Thermosolutal Marangoni boundary layer flows are of great interest due to their applications in industrial applications such as drying of silicon wafers, thin layers of paint, glues, in heat exchangers, and crystal growth in space. The present analysis deals with the effect of chemical radiation and heat absorption/generation of the viscous fluid flow on a thermosolutal Marangoni porous boundary with mass transpiration and heat source/sink. The physical flow problem is mathematically modeled into Navier–Stokes equations. These nonlinear partial differential equations are then mapped into a set of nonlinear ordinary differential equations using similarity transformation. The analytical solutions for velocity, temperature, and concentration profiles are rigorously derived. The solutions so obtained are analyzed through various plots to demonstrate the effect of various physical parameters such as mass transpiration parameter Vc, inverse Darcy number Da−1, Marangoni number Ma, Schmidt number Sc, chemical reaction coefficient (K), Prandtl number (Pr), thermal radiation parameter (NR), and the heat source/sink parameter (I) on the momentum/thermal boundary, and their physical insights are also reported.
Application of the James criterion to explosives with thick cover plates
Authors: Williams J. S. , Howard W. S. , Hawkins S. P.
Published: November 2020

A method for applying the James initiation criterion for explosives with thick cover plates is established. Impact data and corresponding shock induced detonation thresholds were collected and evaluated for flat steel projectiles of different diameters impacting PBX-9501 explosive charges covered by steel plates of various thicknesses. The analysis of the data demonstrated an improved prediction of the detonation thresholds of the explosive charges using the James criterion with a proper accounting of material strength effects, particularly for explosives with relatively thick cover plates. The approach is limited to impacts that produce a one-dimensional flow in the explosive.
Further discussion about transitivity and mixing of continuous maps on compact metric spaces
Authors: Liu Guo , Lu Tianxiu , Yang Xiaofang , Waseem Anwar
Published: November 2020

Let (X, d) be a compact metric space and f : X → X be a continuous map. This work investigates the relationships among various forms of transitivity, such as syndetically transitive, totally transitive, and strongly transitive. Some necessary and sufficient conditions, or sufficient conditions for f to be totally (respectively, strongly and syndetically) transitive, weakly mixing, mixing, and minimal, are obtained. Then, let (K(X),f̄) be the natural extension of (X, f), where K(X) is the family of all nonempty compact subsets of X. The above properties of f̄ are further studied. It is proved that syndetical transitivity, total transitivity, and weak mixing of f̄ are equivalent, and if f̄ is strongly transitive, then f̄ is mixing.
Magnetostrictive iron–gallium alloy harvester with efficient two-mode AC–DC converting technology for effective vibration energy harvesting
Authors: Liu Huifang , Cao Chongdong , Sun Xingwei , Zhao Luyao , Cong Chen
Published: November 2020

A magnetostrictive vibration energy harvester based on an iron–gallium alloy composite cantilever beam is developed, and its capability is optimized from the aspects of bias magnetic field and the number of active layers. To solve the issue of low and irregular output voltage, it designs a converter suitable for a low-power harvester to make full use of the generated electric energy. A set of AC–DC converters with two working modes is designed by using the multiple voltage rectification method, which is able to directly drive low power load or store energy to supply power to higher power load. Through theoretical simulation and experiment, the converter’s characteristics, such as rectifier and filter characteristics, energy storage, and release process are systematically studied and tested. 1 V AC output voltage of the harvester is able to be converted into 5 V DC voltage after being processed by the converter. The proposed harvester provides an excellent vibration harvesting capacity that the AC normalized power density (power density per volume and acceleration) reaches 7.4 mW/(cm3/g). The harvesting system with the two-mode converter has achieved a high normalized DC output power vs AC input voltage of 630 µW/V. We have applied the harvester and converter for a low power electronic meter, which can work normally and display the time, temperature, and humidity in the laboratory. In addition, we have also applied the harvesting system for a higher power (1.2 W) electric fan with a universal serial bus (USB) port. After battery charging and IP5306 voltage boosting, the harvester meets the normal operation requirements of an electric fan with a USB port and it is able to operate normally.
Optical inspection path planning for large liquid crystal glass substrate detection instrument
Authors: Fu Teng , Huang Bin , Xu Zhi , Ma Yunjie , Tao Xiaojie
Published: November 2020

A large liquid crystal glass substrate detection instrument usually uses the air flotation platform to support a glass substrate. The glass substrate will be deformed by air pressure on the air flotation platform, which will affect the accuracy of detection. In this paper, combined with the characteristics of the detection method of the detection instrument, an optimal detection scanning path with the minimum deflection variation range of the glass substrate is planned so as to minimize the influence of glass substrate deformation on the detection accuracy. In theory, the calculation model of the deflection variation ranges of different paths on the glass substrate is established, the numerical method is used to solve it, and finally, the optimal scanning path for the optical inspection is obtained. The experimental results verify the correctness of the model.
Effects of macromolecular crowding on the folding of a polymer chain: A Wang–Landau simulation study
Authors: Taylor Mark P. , Vinci Christopher , Suzuki Ryogo
Published: November 2020

A flexible polymer chain in the presence of inert macromolecular crowders will experience a loss of configurational entropy due to the crowder excluded volume. This entropy reduction will be most pronounced in good solvent conditions where the chain assumes an expanded coil conformation. For polymers that undergo a folding transition from a coil to a compact ordered state, as is the case for many globular proteins, macromolecular crowding is expected to stabilize the folded state and thereby shift the transition location. Here, we study such entropic stabilization effects for a tangent square-well sphere chain (monomer diameter σ) in the presence of hard-sphere (HS) crowders (diameter D ≥ σ). We use the Wang–Landau simulation algorithm to construct the density of states for this chain in a crowded environment and are thus able to directly compute the reduction in configurational entropy due to crowding. We study both a chain that undergoes all-or-none folding directly from the coil state and a chain that folds via a collapsed-globule intermediate state. In each case, we find an increase in entropic stabilization for the compact states with an increase in crowder density and, for fixed crowder density, with a decrease in crowder size (concentrated, small crowders have the largest effect). The crowder significantly reduces the average size for the unfolded states while having a minimal effect on the size of the folded states. In the athermal limit, our results directly provide the confinement free energy due to crowding for a HS chain in a HS solvent.
Nano-particles in optimal concentration facilitate electrically driven dynamic spreading of a drop on a soft viscoelastic solid
Authors: Kumar Sumit , DasGupta Sunando , Chakraborty Suman
Published: November 2020

Electrically driven dynamic spreading of drops on soft solids is of fundamental importance in a plethora of applications ranging from bio-medical diagnostics to liquid lenses and optoelectronics. However, strategies reported in this regard are challenged by the fact that the spreading gets significantly arrested due to viscoelastic dissipation at the three phase contact line. Circumventing these limits, here we bring out a possibility of substantial augmentation in the rate of electro-spreading on a soft matrix by deploying nano-scale fluidic suspensions of optimal volume fraction. We attribute these findings to a consequent increment in the electrical stresses toward combating the viscoelastic dissipation in the interfacial layer. We also present a simple scaling theory that unveils the manner in which the nano-suspension alters the spreading dynamics of a droplet, effectively by changing the final equilibrium contact angle. These findings open up new possibilities of using nano-fluids of optimal concentration toward modulating the dynamic spreading of a drop on a deformable substrate, a paradigm hitherto remaining unexplored.
Multifractal detrended cross-correlation analysis of wind speed and solar radiation
Authors: Plocoste Thomas , Pavón-Domínguez Pablo
Published: November 2020

In this work, the multifractal properties of wind speed and solar radiation are studied in a small region in which a wide variety of micro-climates are concentrated. To achieve this, two years of hourly data are analyzed in Guadeloupe archipelago. The four selected stations for wind speed were chosen according to trade winds direction, while solar radiation is recorded at a representative location at the center of the island. First, the results of the multifractal detrended fluctuation analysis (MF-DFA) showed the multifractal and persistent behaviors of wind speed at all locations. Due to the continental effect that increases along the transect, the Hurst exponent (H) values decrease from east to west. In addition, the MF-DFA clearly highlighted the presence of a nocturnal radiative layer that weakens wind speed in the surface layer. The multifractality degree [Δh(q)] values confirm the peculiarity of wind speed regimes at the center of the island. Thereafter, the MF-DFA results of solar radiation exhibited its multifractal and persistent behavior. Due to the solar radiation planetary scale, its Δh(q) is lower than those obtained for wind speed, which strongly depends on synoptic and local scales. The source of multifractality of wind speed and solar radiation is due to correlations of small and large fluctuations. Finally, the results of the multifractal detrended cross-correlation analysis between wind speed and solar radiation pointed out that the multifractal cross-correlation degree [Δhxy(q)] is identical for each site, which is not the case for Hurst exponent values.
Deconvolutional artificial neural network models for large eddy simulation of turbulence
Authors: Yuan Zelong , Xie Chenyue , Wang Jianchun
Published: November 2020

Deconvolutional artificial neural network (DANN) models are developed for subgrid-scale (SGS) stress in large eddy simulation (LES) of turbulence. The filtered velocities at different spatial points are used as input features of the DANN models to reconstruct the unfiltered velocity. The grid width of the DANN models is chosen to be smaller than the filter width in order to accurately model the effects of SGS dynamics. The DANN models can predict the SGS stress more accurately than the conventional approximate deconvolution method and velocity gradient model in the a priori study: the correlation coefficients can be made larger than 99% and the relative errors can be made less than 15% for the DANN model. In an a posteriori study, a comprehensive comparison of the DANN model, the implicit LES (ILES), the dynamic Smagorinsky model (DSM), and the dynamic mixed model (DMM) shows that the DANN model is superior to the ILES, DSM, and DMM models in the prediction of the velocity spectrum, various statistics of velocity, and the instantaneous coherent structures without increasing the considerable computational cost; the time for the DANN model to calculate the SGS stress is about 1.3 times that of the DMM model. In addition, the trained DANN models without any fine-tuning can predict the velocity statistics well for different filter widths. These results indicate that the DANN framework with the consideration of SGS spatial features is a promising approach to develop advanced SGS models in the LES of turbulence.
Study of spontaneous mobility and imbibition of a liquid droplet in contact with fibrous porous media considering wettability effects
Authors: Ezzatneshan Eslam , Goharimehr Reza
Published: November 2020

In this paper, droplet mobility and penetration into a fibrous porous medium are studied considering different physical and geometrical properties for the fibers. An in-depth insight into the droplet imbibition into the fibrous medium is beneficial for improving membrane products in different applications. Herein, a multiphase lattice Boltzmann method is employed as an efficient numerical algorithm for predicting the multiphase flow characteristics and the interfacial dynamics affected by the interaction between the droplet and fibrous substrates considered. This computational technique is validated by comparison of the present results obtained for different benchmark two-phase flow problems with those reported in the literature, which shows good agreement and confirms its accuracy and efficiency. Droplet spreading and penetration into the fibrous porous geometries are then studied considering various porous topologies, intrinsic contact angles, and fiber sizes. This study shows that the intrinsic contact angle has a great influence on the capillary pressure and, consequently, on the droplet imbibition into the porous medium. The droplet easily penetrates the porous substrate by decreasing the intrinsic contact angle of the fibers, and vice versa. It is also concluded that by coating the fibrous porous medium with a narrow layer of thin fibers, the surface resistance to liquid penetration significantly increases. The present results illustrate that the droplet size impacts the directional wicking ability of the fibrous porous structure used in this study. This property should be considered to produce appropriate two-layer membranes for different applications.
Complete description of the Lyapunov spectra of continuous families of linear differential systems with unbounded coefficients
Authors: Bykov V. V.
Published: November 2020

For every positive integer

and every metric space

we consider the class

of all parametric families

, where

,

,

, of linear differential systems whose coefficients are piecewise continuous and, generally speaking, unbounded on the time semi-axis for every fixed value of the parameter

such that if a sequence

converges to

in the space of parameters, then the sequence

converges uniformly on the semi-axis to the matrix

. For the families in

, we obtain a complete description of individual Lyapunov exponents and their spectra as functions of the parameter.
General Fourier coefficients and convergence almost everywhere
Authors: Gogoladze L. D. , Cagareishvili G.
Published: November 2020

We find sufficient conditions which are in a sense best possible that must be satisfied by the functions of an orthonormal system

in order for the Fourier coefficients of functions of bounded variation to satisfy the hypotheses of the Men’shov–Rademacher theorem. We also prove a theorem saying that every system

contains a subsystem

with respect to which the Fourier coefficients of functions of bounded variation satisfy those hypotheses. The results obtained complement and generalize the corresponding results in [1].
On a class of Anosov diffeomorphisms on the infinite-dimensional torus
Authors: Glyzin S. D. , Kolesov A. Yu. , Rozov N. Kh.
Published: November 2020

We study a quite natural class of diffeomorphisms

on

, where

is the infinite-dimensional torus (the direct product of countably many circles endowed with the topology of uniform coordinatewise convergence). The diffeomorphisms under consideration can be represented as the sums of a linear hyperbolic map and a periodic additional term. We find some constructive sufficient conditions, which imply that any

in our class is hyperbolic, that is, an Anosov diffeomorphism on

. Moreover, under these conditions we prove the following properties standard in the hyperbolic theory: the existence of stable and unstable invariant foliations, the topological conjugacy to a linear hyperbolic automorphism of the torus and the structural stability of

.
Exact value of the exponent of convergence of the singular integral in Tarry’s problem for homogeneous polynomials of degree

in two variables
Authors: Chakhkiev M. A.
Published: November 2020

Jabbarov [1] obtained the exact value of the exponent of convergence of the singular integral in Tarry’s problem for homogeneous polynomials of degree

. We extend this result to the case of polynomials of degree

.
Approximation in measure: the Dirichlet problem, universality and the Riemann hypothesis
Authors: Falcó J. , Gauthier P. M.
Published: November 2020

We use approximation in measure to solve an asymptotic Dirichlet problem on arbitrary open sets and to show that many functions, including the Riemann zeta-function, are universal in measure. Connections with the Riemann hypothesis are suggested.
Nevanlinna factorization in weighted classes of analytic functions of variable smoothness
Authors: Shirokov N. A.
Published: November 2020

We define a new class of functions of variable smoothness that are analytic in the unit disc and continuous in the closed disc. We construct the theory of the Nevanlinna outer-inner factorization, taking into account the influence of the inner factor on the outer function, for functions of the new class.