bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excellent Polyimide Dielectrics Containing Conjugated ACAT for High‐Temperature Polymer Film Capacitor
Authors: Wu Zhiqiang , Guo Qiang , Liu Yang , Zhou Huihui , Zheng Hua , Lei Xingfeng , Gong Lei , Chen Yanhui , Liu Zhenguo , Zhang Qiuyu 
Published: September 2021

AbstractIn order to meet the requirements of polymer dielectric materials for high thermal stability and excellent dielectric properties in the application of high‐temperature film capacitors, a series of polyimide (PI) films are fabricated by introducing a self‐synthesized aniline trimer (ACAT) with a conjugated structure in this work. Since the conjugated ACAT in the main chains of PI improves the electron polarization and carrier mobility of the PI molecular chains, the dielectric constant of the ACAT‐PI films is greatly enhanced (4.4–7.4). Meanwhile, the dissipation factor does not increase apparently (0.002–0.013). The dielectric properties are stable even when the temperature is up to 200 °C, the thermal degradation temperature is as high as 450 °C, and the mechanical properties are also excellent (70–105 MPa). Among all the films, the PI film with 5 mol% ACAT exhibits the maximal energy density of 3.6 J cm−3 under the field of 426 kV mm−1, the high tensile strength (90 MPa) and the excellent thermal stability (Td5 = 515 °C). The work paves the way to prepare high‐temperature polymer dielectric film materials with high energy storage density.
Theory of Y‐ and Comb‐Shaped Polymer Brushes: The Parabolic Potential Framework
Authors: Lebedeva Inna O. , Zhulina Ekaterina B. , Leermakers Frans A.M. , Sheiko Sergei S. , Borisov Oleg V. 
Published: September 2021

AbstractThe parabolic approximation for self‐consistent molecular potential is widely used for theoretical analysis of conformational and thermodynamic properties of polymer brushes formed by linear or branched macromolecules. The architecture‐dependent parameter of the potential (topological coefficient) can be calculated for arbitrary branched polymer architecture from the condition of elastic stress balance in all the branching points. However, the calculation routine for the topological coefficient does not allow unambiguously identifying the range of applicability and the accuracy of the parabolic approximation. Here the limits of applicability of parabolic approximation are explored by means of numerical self‐consistent field method for brushes formed by Y‐shaped and comb‐like polymers. It is demonstrated that violation of the potential parabolic shape can be evidenced by appearance of multimodal distribution of the end monomer unit in the longest elastic path of the macromolecule. The asymmetry of branching of Y‐shaped polymers does not disturb the parabolic shape of the potential as long as the degree of polymerization of the root segment remains sufficiently large. The same applies to comb‐shape polymers with sufficiently long main chain and large number of branching points. For short comb‐like polymers multiple modes in the distribution of the end monomer unit of the main chain are observed and related to deviation from the parabolic shape of the potential.
Far and wide: Exploring provider utilization of remote service provision for genome‐wide sequencing in Canada
Authors: Enns Emily A. , Wainstein Tasha , Dragojlovic Nick , Kopac Nicola ,   GenCOUNSEL Study, Lynd Larry D. , Elliott Alison M. 
Published: September 2021

AbstractBackgroundIn Canada, funding for genome‐wide sequencing (GWS; exome and whole genome) is provincially regulated. We characterized the uptake of GWS by genetics health professionals (GHPs) across Canada and describe how they use remote technologies for patient access to GWS and genomic counseling.MethodsWe distributed a survey to 574 Canadian GHPs addressing: GWS use, remote technologies (e.g., telephone, videoconferencing) for GWS and provider opinions regarding these technologies. Data were summarized using descriptive statistics. Associations between variables were evaluated using Chi‐square and Fisher's Exact tests for categorical data, and t‐tests or Mann–Whitney U tests for continuous data.ResultsOf 116 GHPs, 50% reported using GWS in the last year and 57% of GWS users reported using remote technologies. Clinical geneticists who did not use GWS reported lack of provincial funding as the principal reason. Remote technologies were most commonly used for informed consent and results, and rarely used for initial consultations. Average wait times for a GWS appointment were shorter for remote appointments (mean 44.2 (SD 40.2) weeks) than for in‐person (mean 58.2 (SD 42.9), p = 0.036).ConclusionThe use of GWS varied across Canada, professional designation, and discipline. Funding remains a barrier to GWS access. Remote technologies increase patient access with reduced wait times.
Beckwith–Wiedemann syndrome: Clinical, histopathological and molecular study of two Tunisian patients and review of literature
Authors: Sassi Hela , Elaribi Yasmina , Jilani Houweyda , Rejeb Imen , Hizem Syrine , Sebai Molka , Kasdallah Nadia , Bouthour Habib , Hannachi Samia , Beygo Jasmin , Saad Ali , Buiting Karin , H’mida Ben‐Brahim Dorra , BenJemaa Lamia 
Published: September 2021

AbstractBackgroundBeckwith–Wiedemann syndrome (BWS) is a rare overgrowth syndrome characterized by congenital malformations and predisposition to embryonic tumors. Loss of methylation of imprinting center 2 (IC2) is the most frequent alteration and rarely associated with tumors compared to paternal uniparental disomy of chromosome 11 (UPD(11)pat) and gain of methylation of imprinting center 1.MethodsOur study aimed to describe the clinical, histopathological and genetic characteristics of two patients and establish genotype‐phenotype correlations. The clinical diagnosis was based on the criteria defined by the international expert consensus of BWS. Molecular study of 11p15.5 methylation status was assessed using methylation‐specific‐multiplex ligation probe amplification (MS‐MLPA).ResultsPatients were aged 12 months and 3 months and fulfilled the clinical score of BWS. MS‐MLPA showed molecular alterations consisting of loss of methylation in IC2 (IC2‐LOM) at the maternal allele for one patient and a mosaic UPD(11)pat for the second patient in whom follow‐up at 6months revealed adrenocortical carcinoma (ACC) with low grade of malignancy. Molecular subtypes guide the follow‐up and tumor surveillance, our major concern.ConclusionWe have to take into account the psychological impact of a possible tumor whatever the underlying mechanism is. Nevertheless, the tumor risk remains high for UPD(11)pat. Our study extended the phenotype of BWS with absence of macrosomia in Tunisian patients, contrasting with literature, and added a supplementary case of ACC in the tumor spectrum of BWS patients with UPD(11)pat.
Influence of Poisons Originating from Chemically Recycled Plastic Waste on the Performance of Ziegler–Natta Catalysts
Authors: Pernusch Daniel Christian , Spiegel Gunnar , Paulik Christian , Hofer Wolfgang 
Published: September 2021

AbstractChemically recycled monomer feed streams from postconsumer plastic packaging waste are expected to contain impurities that act as catalyst poisons. This work investigates the impact of such impurities on a commercial fourth‐generation Ziegler–Natta catalyst system. A recycled monomer feed stream in two different procedures by adding representative catalyst poisons (pyridine and n‐butanol) in various quantities to the reactor setup is simulated. Measuring catalyst activity and molecular weight distribution (MWD) and performing kinetic and MWD deconvolution modeling, the impact of the catalyst poisons on polymer product properties at the microstructural level is evaluated. The results demonstrate that, beyond a certain concentration (120 ppm), catalyst poisons have a substantial impact on the activity levels of the catalyst system tested. MWD deconvolution modeling shows an influence of the poisons on the composition of the resulting polymer product in the form of a shift toward lower or higher molecular weights (depending on the procedure). This microstructural analysis highlights the importance of purifying chemically recycled monomer feed streams.
A sparse domain decomposition method for parallel computing of a four‐dimensional lattice spring model
Authors: Fu Meng , Zhao Gao‐Feng 
Published: September 2021

AbstractIn this work, an improved domain decomposition method is developed to address workload imbalance when implementing the parallel computing of a four‐dimensional lattice spring model (4D‐LSM) to solve problems in rock engineering on a large scale. A cubic domain decomposition scheme is adopted and optimized by a simulated annealing algorithm (SAA) to minimize the workload imbalance among subdomains. The improved domain decomposition method is implemented in the parallel computing of the 4D‐LSM. Numerical results indicate that the proposed domain decomposition method can further improve the workload balance among processors, which is helpful to supersede the limit of computational scale when solving large‐scale geotechnical problems and decrease the runtime of the parallel 4D‐LSM by at most 40% compared to the original cubic decomposition method. This shows the practicability of the proposed method in parallel computing. Two types of target functions of SAA are tested, and their influence on the performance of the parallel 4D‐LSM is investigated. Finally, a computational model with one billion particles for one actual engineering application of using 4D‐LSM is realized, and the result shows the advantages of parallel computing.
Second‐order design sensitivity analysis using diagonal hyper‐dual numbers
Authors: Endo Vitor Takashi , Fancello Eduardo Alberto , Muñoz‐Rojas Pablo Andrés 
Published: September 2021

AbstractAlthough sensitivity analysis provides valuable information for structural optimization, it is often difficult to use the Hessian in large models since many methods still suffer from inaccuracy, inefficiency, or limitation issues. In this context, we report the theoretical description of a general sensitivity procedure that calculates the diagonal terms of the Hessian matrix by using a new variant of hyper‐dual numbers as derivative tool. We develop a diagonal variant of hyper‐dual numbers and their arithmetic to obtain the exact derivatives of tensor‐valued functions of a vector argument, which comprise the main contributions of this work. As this differentiation scheme represents a general black‐box tool, we supply the computer implementation of the hyper‐dual formulation in Fortran. By focusing on the diagonal terms, the proposed sensitivity scheme is significantly lighter in terms of computational costs, facilitating the application in engineering problems. As an additional strategy to improve efficiency, we highlight that we perform the derivative calculation at the element‐level. This work can contribute to many studies since the sensitivity scheme can adapt itself to numerous finite element formulations or problem settings. The proposed method promotes the usage of second‐order optimization algorithms, which may allow better convergence rates to solve intricate problems in engineering applications.
Four almost unexplored species of Brazilian Connarus (Connaraceae): Chemical composition by ESI‐QTof‐MS/MS–GNPS and a pharmacologic potential
Authors: Nunes Alves Paim Luís Fernando , dos Santos Paulo Roberto , Patrocinio Toledo Cássio Augusto , Minello Luana , Lima da Paz Joicelene Regina , Castro Souza Vinicius , Salvador Mirian , Moura Sidnei 
Published: September 2021

AbstractIntroductionSpecies of Connaraceae are globally used in traditional medicines. However, several of these have not been studied regarding their chemical composition, and some are even at risk of extinction without proper studies. Therefore, the chemical composition and pharmacological potential of Connarus blanchetii Planch., Connarus nodosus Baker, Connarus regnellii G. Schellenb., and Connarus suberosus Planch., which were previously unknown, were analyzed.ObjectiveThis work aims to investigate the pharmacological potential of these four Connarus species. The chemical composition of different extracts was determined by high‐resolution mass spectrometry (HRMS), with subsequent analysis by the GNPS platform and competitive fragmentation modeling (CFM).Materials and methodsLeaf extracts (C. blanchetii, C. nodosus, C. regnellii, and C. suberosus) and bark extracts (C. regnellii and C. suberosus) were obtained by decoction, infusion, and maceration. LC/HRMS data were submitted to the GNPS platform and evaluated using CFM in order to confirm the structures.ResultsThe HRMS–GNPS/CFM analysis indicated the presence of 23 compounds that were mainly identified as phenolic derivatives from quercetin and myricetin, of which 21 are unedited in the Connarus genus. Thus, from the analyses performed, we can identify different compounds with pharmacological potential, as well as the most suitable forms of extraction.ConclusionUsing HRMS–GNPS/CFM, 21 unpublished compounds were identified in the studied species. Therefore, our combination of data analysis techniques can be used to determine their chemical composition.
Identification of multiple proteins whose interaction with mannitol dehydrogenase is induced by salicylic acid: Implications for unconventional secretion
Authors: Ho Tricia C. , Blackburn R. Kevin , Goshe Michael B. , Williamson John D. 
Published: September 2021

AbstractAlthough protein secretion was previously believed to be solely via ER/Golgi pathways, Golgi‐independent secretion has now been described in both animals and plants. Secretion of the mannitol catabolic enzyme mannitol dehydrogenase (MTD) in response to the endogenous pathogen response signal salicylic acid (SA) was one of the first reports of unconventional protein secretion in plants. To begin assessing potential secretion‐associated MTD protein interactors, we present here high‐quality databases describing changes in MTD‐interacting proteins following SA treatment of Arabidopsis thaliana cells expressing MTD.
Reliability and validity of subjective radiologist reporting of temporal changes in lumbar spine MRI findings
Authors: Hancock Mark J. , Maher Chris G. , Jarvik Jeffrey G. , Battié Michele C. , Elliott James M. , Jensen Tue S. , Panagopoulos John , Jenkins Hazel , Pardey Margery C. , McIntosh Jeffery , Magnussen John 
Published: September 2021

AbstractBackgroundThe importance of lumbar findings on magnetic resonance imaging (MRI) remains controversial. Changes in lumbar MRI findings over time may provide important insights into the causes of low back pain. However, the reliability and validity of temporal changes are unknown.ObjectiveTo (1) investigate the interrater reliability of subjective radiologist reporting of temporal changes in lumbar spine MRI findings and (2) determine how commonly temporal changes are reported when two scans are conducted 30 minutes apart (considered false positives).DesignCross‐sectional study.SettingRadiology clinic.ParticipantsForty volunteers (mean age 40; 53% female) with current (n = 31) or previous (n = 9) low back pain underwent initial lumbar MRI on a single 3T scanner. Participants then lay on a bed for 30 minutes before undergoing an identical MRI. In addition, we purposely selected five participants from a previous study with repeat lumbar MRI scans where temporal changes were reported in at least one MRI finding (1–12 weeks after initial scan) and another five participants where no temporal change was reported. The 10 participants were included in analyses for aim 1 only.InterventionsNot applicable.Main Outcome MeasuresTwo blinded radiologists reported on temporal changes between the baseline and repeat scan for 12 different MRI findings (eg, disk herniation, annular fissure) at five levels.ResultsThe interrater reliability of subjective reporting of temporal changes was poor for all MRI findings based on Kappa values (≤ 0.24), but agreement was relatively high (≥ 90.8%). This is explained by the low prevalence of temporal changes as demonstrated by high values for Prevalence and Bias Adjusted Kappa (≥ 0.82). “False positive” temporal changes were reported by at least one radiologist for most MRI findings, but the rate was generally low.ConclusionsCaution is required when interpreting temporal changes in lumbar MRI findings owing to low reliability and some false positive reporting.
Decisional capacity determination and serious mental illness in oncology: Implications for equitable and beneficent care
Authors: McFarland Daniel C. , Voigt Louis , Alici Yesne 
Published: September 2021

AbstractBackgroundPatients with Serious Mental Illness (SMI) have worse survival compared to cancer patients without SMI after controlling for delayed diagnosis. Decision‐making capacity (DMC) may be impaired in both populations (cancer or SMI). DMC may be further impaired based on coupled vulnerability factors that challenge Shared Decision Making (SDM) for patients with cancer and SMI.MethodsPsychiatric consultations for DMC in hospitalized patients with cancer (n = 97) were consecutively evaluated across a single institution cancer center. SMI data, demographic, and cancer‐related variables were obtained from the medical record. Descriptive data were contrasted in patients with and without DMC and used for logistic regression modeling.ResultsOverall, 42% had DMC with no significant differences based on SMI (χ2 = 2.60,p = 0.11). Patients with SMI were younger, receiving anticancer treatment, and were less likely facing end of life issues. Age (OR 1.03,p = 0.05) and no recent anticancer treatments (OR 0.34,p = 0.02) were associated with decisional incapacity. At 3 months post discharge, almost two‐thirds were dead with no difference based on SMI (χ2 = 0.01,p = 0.91). But End of Life (EOL) concerns were documented in 63% of non‐SMI patients and only 36% of SMI patients (χ2 = 5.63,p = 0.02). Healthcare proxy (16%), four determinates of DMC (22%), and repeated psychiatric DCM assessments (35%) were documented with no differences based on SMI.ConclusionSDM is not equitable for cancer patients with SMI. Advanced directives and a robust effort to provide value‐congruent care for patient with SMI who develop cancer may lessen this health inequity for cancer patients with SMI.
Proteomic study of apheresis platelets made HLA class I deficient for transfusion of refractory patients
Authors: Mirlashari Mohammad Reza , Vetlesen Annette , Nissen‐Meyer Lise Sofie H. , Stensland Maria Ekman , Singh Sachin Kumar , Nyman Tuula Anneli , Hetland Geir 
Published: September 2021

AbstractPurposeRefractoriness can occur after repeated platelet (PLT) transfusions because of alloimmunization to HLA class I antigens on transfused PLTs and generation of anti‐HLA antibodies that bind to the foreign PLTs and initiate their destruction. Such refractoriness can be overcome by provision of HLA‐matched PLTs from HLA typed donors. However, since the procedure is both expensive and time‐consuming, an alternative approach is to deplete PLTs of HLA class I molecules by a brief treatment with citric acid, on ice. This is shown to be feasible without damaging PLT function. We used label free quantitative mass spectrometry (MS)‐based proteomics to investigate the effect of acid treatment on apheresis PLTs for combatting immunologic PLT refractoriness.Experimental DesignProteomic analyses are undertaken using PLTs from seven apheresis concentrates, which were split in two with or without acid treatment.ResultsIn total 1717 proteins in apheresis PLTs were quantified using proteomics. Data are available via ProteomeXchange with identifier PXD027893 . Of these, the amount of 80 proteins changed significantly after acid treatment, but overall there were not any major differences in proteomes between samples with and without acid treatment.Conclusions and Clinical RelevanceIn general, the changes of PLT proteins after treatment with citric acid were quite small and functionally safe. Hence, this result taken together with our previously published data indicates that acid treated PLTs can be used for treatment of patients with PLT refractoriness and opens up for a clinical trial.
Influences of the Random Stacking and Charge's Diameter on Compression and Fracture Process of Propellant Charge
Authors: Li Chao , Rui Xiaoting , Gu Junjie , Gu Jian , Wang Yan 
Published: September 2021

AbstractAfter decades of unremitting research on the launch safety of propellant charge at home and abroad, it is gradually recognized that the fractured propellant charge generated by the compression process of propellant particles is the leading cause of chamber explosion. The large numbers of particles in propellant charge inevitably bring out the complexity in describing the fracture process under impact load in description. The discrete element method is applied to study the influences of the random stacking configurations of propellant charge and the charge diameter on the compression and fracture process of propellant charge in this paper. The results show that the random stacking of propellant bed influences little on the fracture process under the same impact load. When the diameter of propellant charge is larger than a certain value, the charge's diameter has little influence on the fracture process.
Experimental Investigation on Combustion Characteristics and Agglomeration of Al/NEPE Propellants
Authors: Zhang Beichen , Xu Jinsheng , Feng Yaya , Zhang Anjie , Chen Xiong , Cai Wengxiang , Yingkun Li , Zhu Min 
Published: September 2021

AbstractIn order to understand the ignition and combustion characteristics of NEPE propellants under different pressure conditions and the agglomeration behavior of aluminum particles on the burning surface, the Al/NEPE propellant was tested on a sealed high‐pressure laser ignition platform. Laser ignition experiments show that both ignition delay time and combustion time are inversely proportional to ambient pressure. With the increase of pressure, the reduction of ignition delay time and self‐sustaining combustion time is reduced. The impact of pressure on ignition and combustion is very complex. We then analyze the effect of pressure on ignition delay time using a theoretical mechanism. High‐speed microscopic images display the agglomeration of aluminum particles in propellants mainly through the following three processes: accumulation, aggregation, and agglomeration. It is also found that many aluminum particles are agglomerated on the surface, the aluminum droplet agglomerates formed on the combustion surface are separated from the combustion surface, and the agglomerates rupture and flow out of the liquid alumina during the combustion process. The phenomenon of secondary agglomeration is also observed. The microstructure and elemental composition of combustion products of aluminum particles in NEPE propellant were obtained by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The detection results confirmed some agglomeration phenomena. At 3.0 MPa, the combustion of the propellant sample is sufficient, and the aluminum particles are smooth spherical alumina particles. At 1.0 MPa, the combustion of the propellant sample is insufficient, and the aluminum particles are rough. The particle size under different pressure was analyzed by a laser particle size analyzer. The results show that increasing the pressure can reduce the average agglomeration size of aluminum particles and improve combustion efficiency. The number of large particle aggregates is more at 3 MPa. From the perspective of overall particle size results, within the same diameter interval, the percentage of particle number does not increase or decrease significantly with the increase of pressure.