bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ultrasonic extrusion of star styrene‐butadiene rubber on properties of carbon black‐ and silica‐filled compounds and vulcanizates
Authors: Liang Tian , Isayev Avraam I. 
Published: January 2019

ABSTRACTExtrusion of star styrene‐butadiene rubber (SBR) without and with ultrasonic treatment at amplitudes 3.5, 5, 7.5, and 10 μm was carried out. The molecular structure of untreated and treated star SBR was determined. Significant reduction of die pressure was observed during ultrasonic treatment due to the thixotropic and degradation effects. Ultrasonic treatment of star SBR at 3.5 μm created molecules of higher molecular weight via long‐chain branching without gel formation. Ultrasonic treatment of star SBR at 5 μm created a small amount of gel. At high ultrasonic amplitudes more gel was generated hindering mixing of star SBR with silica. Extruded star SBR was compounded with carbon black and precipitated silica, with and without silane. It was found that the long‐chain branching induced by ultrasonic treatment improved the rubber–filler interaction in precipitated silica without silane, as confirmed by the increase of bound rubber content. The filler–filler interaction was reduced in silica compounds without silane, as indicated by study of Payne effect. The significantly improved rubber–filler interaction and reduced filler–filler interaction led to an increase of the modulus at 100% elongation and tensile strength of SBR/silica vulcanizates. Extensive comparisons were made with earlier study on ultrasonic treatment of linear SBR. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47451.
Polymer concentration detection method based on fluorescent polymer to evaluate its retention and percolation
Authors: Kang Wanli , Gao Yongbo , Tang Xuechen , Cao Changxiao , Hu Leilei , Yang Hongbin 
Published: January 2019

ABSTRACTA new fluorescent polymer was prepared by copolymerization of acrylamide and a modified rhodamine B (RhB). Fourier transformation infrared spectrometer and nuclear magnetic resonance confirmed the successful modification of RhB and the synthesis of fluorescent polymer. The rheological and fluorescence properties were studied by fluorospectrophotometer and rotational rheometer. The adsorption retention and percolation properties were evaluated by sand pack displacement experiments. The results indicated that fluorescence intensity revealed a distinct linear relationship with polymer concentration within a certain concentration range. High temperature and strong acidic conditions could diminish fluorescence intensity whereas formation water ions exerted inconsiderable influence on it. Rheological results manifested that fluorescent polymer can be used as polymer flooding agent. The sand pack displacement results proved the feasibility of using fluorescent polymer to detect polymer concentration. By this means, polymer breakthrough time and concentration variations could be confirmed. Based on the curves of injection pressure and polymer concentration, the percolation state and retention of polymer were able to be analyzed. Significantly, this work can provide support and guidance for the practical applications of fluorescent polymer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47468.
Feeding Biomechanics in Billfishes: Investigating the Role of the Rostrum through Finite Element Analysis
Authors: Habegger Laura , Motta Philip , Huber Daniel , Pulaski Daniel , Grosse Ian , Dumont Elizabeth 
Published: January 2019

ABSTRACTBillfishes are large pelagic fishes that have an extreme elongation of the upper jaw bones forming the rostrum. Recent kinematic and biomechanical studies show the rostrum to be associated to feeding, however, it is less clear how the wide range of morphologies present among billfish may affect their striking behavior. In this study, we aim to assess the mechanical performance of different rostrum morphologies under loads that simulate feeding and to test existing hypotheses of species‐specific feeding behaviors. We use finite element analysis (FEA)—a physics‐based method that predicts patterns of stress and strain in morphologically complex structures under specified boundary conditions—to test hypotheses on the form and mechanical performance of billfish rostra. Patterns of von Mises stress and total strain energy suggest that distinct rostral morphologies may be functionally segregated. The rounder blue marlin rostrum may be better suited for a wide range of slashing motions to disable prey, whereas the more flattened swordfish rostrum appears to be more specialized for lateral swiping during prey capture. The almost homogenous stress distribution along each rostrum implies their possible use as a predatory weapon regardless of morphological differences between species. The mechanical implications of other less commonly reported behaviors such as spearing are discussed, as well as the potential impact of hydrodynamics in shaping the evolution of the rostrum in this lineage. Anat Rec, 2019. © 2019 American Association for Anatomy.
Performance of Candidate Serum Biomarkers for Systemic Sclerosis–Associated Interstitial Lung Disease
Authors: Elhai Muriel , Hoffmann‐Vold Anna Maria , Avouac Jérôme , Pezet Sonia , Cauvet Anne , Leblond Agathe , Fretheim Håvard , Garen Torhild , Kuwana Masataka , Molberg Øyvind , Allanore Yannick 
Published: January 2019

ObjectiveInterstitial lung disease (ILD) in systemic sclerosis (SSc) runs a highly variable course, and prediction tools are highly desired. The aim of this study was to assess the diagnostic and prognostic performance of 4 candidate serum biomarkers for SSc‐associated ILD.MethodsSerum samples from a combined cohort of SSc patients (from Paris, France and Oslo, Norway; n = 427) were analyzed by enzyme‐linked immunosorbent assay for concentrations of lung epithelial–derived surfactant protein D (SP‐D), Krebs von den Lungen 6 glycoprotein (KL‐6), CCL18, and OX40 ligand (OX40L). Lung fibrosis was measured by high‐resolution computed tomography and pulmonary function tests. Associations of these candidate biomarkers with baseline disease involvement and prediction of disease progression over time (mean ± SD follow‐up 3.2 ± 4.4 years) were investigated.ResultsIn SSc patients at baseline, serum levels of KL‐6 correlated with the forced vital capacity (FVC) (r = −0.317, P < 0.001), diffusing capacity for carbon monoxide (r = −0.335, P < 0.001), and extent of lung fibrosis (r = 0.551, P < 0.001). In multivariate analyses, serum levels of KL‐6 and SP‐D, but not CCL18 and OX40L, were associated with lung fibrosis (odds ratio [OR] 2.41, 95% confidence interval [95% CI] 1.43–4.07 [P = 0.001] and OR 3.15, 95% CI 1.81–5.48 [P < 0.001], respectively). In SSc patients with ILD at baseline, longitudinal, multivariate analyses showed that CCL18 serum levels were an independent predictor of a >10% decrease in the FVC (hazard ratio [HR] 2.90, 95% CI 1.25–6.73; P = 0.014) and de novo development of extensive disease (HR 3.71, 95% CI 1.02–13.52; P = 0.048). Matrix‐based logistic regression models for the diagnosis and prognosis of SSc‐associated ILD were constructed, and these models discriminated 3 groups of risk (mild, moderate, or high) for the diagnosis or worsening of lung fibrosis according to the serum levels of SP‐D (for diagnosis) and serum levels of CCL18 (for progression of disease).ConclusionThese results show that SP‐D is a relevant diagnostic biomarker for SSc‐associated ILD, whereas KL‐6 could be used to assess the severity of lung fibrosis. CCL18 appears to be a potential predictive marker for progression of ILD in SSc.
Carbonyl Compounds′ Journey to Amide Bond Formation
Authors: Narendar Reddy Thatikonda , Beatriz Adilson , Jayathirtha Rao Vaidya , de Lima Dênis Pires 
Published: January 2019

AbstractThe formation of amide bonds is one of the most stimulating emerging areas in organic and medicinal chemistry. Amides are recognized as central building blocks in a plethora of interesting pharmaceuticals, proteins, peptides, polymers, natural products, functional materials, and biologically relevant carbocyclic or heterocyclic molecules, and they are also found in a variety of industrial fields. Therefore, a review of recent developments and challenges in the formation of amide bonds from carbonyl compounds is particularly important. Herein, we have scrutinized a range of metal‐catalyzed and metal‐free approaches for the synthesis of amides from aldehydes, ketones, and oximes. In addition, this Minireview highlights relevant mechanistic studies, as well as the potential applications of these methods in the synthesis of candidate drug molecules. We hope that the data compiled herein will encourage further progress in this notable area of chemistry research.
Control of Circularly Polarized Luminescence by Orientation of Stacked π‐Electron Systems
Authors: Kikuchi Katsuaki , Nakamura Jun , Nagata Yuuya , Tsuchida Hiromu , Kakuta Takahiro , Ogoshi Tomoki , Morisaki Yasuhiro 
Published: January 2019

AbstractPlanar chiral building blocks based on 4,7,12,15‐tetrasubstituted [2.2]paracyclophanes were obtained via a synthetic route involving an optical resolution step. Planar chiral enantiomers, comprising two fluorophores that were stacked to form a V‐shaped higher‐ordered structure, were synthesized from these building blocks. The V‐shaped molecules emitted intense circularly polarized luminescence (CPL). Their chiroptical properties were compared with those of X‐shaped molecules bearing the same two fluorophores stacked together. The CPL sign of the X‐shaped molecule was opposite to that of the V‐shaped molecule, which is supported by the theoretical results, indicating that the CPL sign can be controlled by the orientation of the stacked fluorophores.
Hypoxia‐Activated Prodrugs of PERK Inhibitors
Authors: Liew Lydia P. , Singleton Dean C. , Wong Way W. , Cheng Gary J. , Jamieson Stephen M. F. , Hay Michael P. 
Published: January 2019

AbstractTumour hypoxia plays an important role in tumour progression and resistance to therapy. Under hypoxia unfolded proteins accumulate in the endoplasmic reticulum (ER) and this stress is relieved through the protein kinase R‐like ER kinase (PERK) signalling arm of the unfolded protein response (UPR). Targeting the UPR through PERK kinase inhibitors provides tumour growth inhibition, but also elicits on‐mechanism normal tissue toxicity. Hypoxia presents a target for tumour‐selective drug delivery using hypoxia‐activated prodrugs. We designed and prepared hypoxia‐activated prodrugs of modified PERK inhibitors using a 2‐nitroimidazole bioreductive trigger. The new inhibitors retained PERK kinase inhibitory activity and the corresponding prodrugs were strongly deactivated. The prodrugs were able to undergo fragmentation following radiolytic reduction, or bioreduction in HCT116 cells, to release their effectors, albeit inefficiently. We examined the effects of the prodrugs on PERK signalling in hypoxic HCT116 cells. This study has identified a 2‐substituted nitroimidazole carbamate prodrug with potential to deliver PERK inhibitors in a hypoxia‐selective manner.
Impact time and angle constrained integrated guidance and control with application to salvo attack
Authors: Wang Xiang Hua , Tan Chee Pin , Cheng Li Ping 
Published: January 2019

AbstractIn this paper, a novel method is proposed to estimate the impact time (time taken to hit the target) for missiles guided by integrated guidance and control (IGC). Firstly, the elevator deflection command is directly designed in the frame of IGC to make the line‐of‐sight (LOS) angle converge to the desired value in finite time; thereafter, the missiles will fly along the desired LOS until they hit the target. Then a method to estimate the impact time is provided; this can help the user systematically choose the missile parameters in order to achieve a certain impact time, and thus this result can be applied to the case of salvo attack of multiple missiles without online data links. Finally, simulation studies are performed to verify the effectiveness of the proposed scheme.
Dyadic interactions in children exhibiting the broader autism phenotype: Is the broader autism phenotype distinguishable from typical development?
Authors: Kellerman A. M. , Schwichtenberg A. J. , Tonnsen B. L. , Posada G. , Lane S. P. 
Published: January 2019

In families raising a child with an autism spectrum disorder (ASD), infant siblings are at elevated risk for ASD and other developmental concerns, including elements of the broader autism phenotype (BAP). Typically, the BAP is indexed using standardized developmental assessments; however, these measures do not capture a number of social difficulties commonly associated with the BAP. The present study aims to expand our developmental understanding of the BAP by comparing children exhibiting the BAP to their typically developing peers on, (a) standardized measures of development, and (b) social behaviors exhibited during dyadic play interactions. As part of a prospective study, dyads were recruited from families with at least one older child with ASD (high‐risk, n = 36), and families with no history of ASD (low‐risk, n = 38). During laboratory visits at 12, 15, 18, and 24 months of age, infants completed a series of standardized assessments and a mother–child play interaction. Dyadic play interactions were micro‐analytically coded for gaze, positive affect, and vocalizations to create theory‐driven composites to index dyadic synchrony and responsiveness. Videos were also coded with an existing rating scheme for joint engagement and child responsiveness. Multilevel models revealed significant group differences on select constructs within the first 2 years. Language and cognitive differences emerged by 24 months of age, whereas dyadic differences were evident as early as 15 months. Recognizing the increasing demand for elevated‐risk interventions, these findings highlight several social constructs through which interventions may identify risk and promote optimal development. Autism Res 2019, 12: 469–481 © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryIn families raising children with an autism spectrum disorder (ASD), younger siblings are at an increased risk for social and developmental difficulties that characterize a “broader autism phenotype.” The present study explored the emergence of social, language, and cognitive differences in the first 2 years of life. Social differences were evident as early as 15 months of age for several play‐based measures, and language and cognitive differences emerged by 24 months of age. For infant siblings of children with ASD, some of the earliest behavioral marks for subclinical features of ASD are evident within the first 2 years of life.
The stability of joint engagement states in infant siblings of children with and without ASD: Implications for measurement practices
Authors: Bottema‐Beutel Kristen , Kim So Yoon , Crowley Shannon , Augustine Ashley , Kecili‐Kaysili Bahar , Feldman Jacob , Woynaroski Tiffany 
Published: January 2019

Obtaining stable estimates of caregiver–child joint engagement states is of interest for researchers who study development and early intervention in young children with autism spectrum disorder (ASD). However, studies to date have offered little guidance on the numbers of sessions and coders necessary to obtain sufficiently stable estimates of these constructs. We used procedures derived from G theory to carry out a generalizability study, in which we partitioned error variance between two facets of our system for measuring joint engagement states: session and coder. A decision study was then conducted to determine the number of sessions and coders required to obtain g coefficients of 0.80, an a priori threshold set for acceptable stability. This process was conducted separately for 10 infant siblings of children with ASD (Sibs‐ASD) and 10 infants whose older sibling did not have ASD (Sibs‐TD), and for two different joint engagement states; lower‐ and higher‐order supported joint engagement (LSJE and HSJE, respectively). Results indicated that, in the Sibs‐ASD group, four sessions and one coder was required to obtain acceptably stable estimates for HSJE; only one session and one coder were required for LSJE. In the Sibs‐TD group, two sessions and one coder were required for HSJE; seven sessions and two coders were required for LSJE. Implications for measurement in future research are discussed. Autism Res 2019, 12: 495–504 © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryThis study offers guidance for researchers who measure joint engagement between caregivers and infants who have an older sibling with ASD, and who have older siblings who are TD.
Assessing availability and greenhouse gas emissions of lignocellulosic biomass feedstock supply – case study for a catchment in England
Authors: Ni Yuanzhi , Mwabonje Onesmus N. , Richter Goetz M. , Qi Aiming , Yeung Kenny , Patel Martin , Woods Jeremy 
Published: January 2019

AbstractFeedstocks from lignocellulosic biomass (LCB) include crop residues and dedicated perennial biomass crops. The latter are often considered superior in terms of climate change mitigation potential. Uncertainty remains over their availability as feedstocks for biomass provision and the net greenhouse gas emissions (GHG) during crop production. Our objective was to assess the optimal land allocation to wheat and Miscanthus in a specific case study located in England, to increase biomass availability, improve the carbon balance (and reduce the consequent GHG emissions), and minimally constrain grain production losses from wheat. Using soil and climate variables for a catchment in east England, biomass yields and direct nitrogen emissions were simulated with validated process‐based models. A ‘Field to up‐stream factory gate’ life‐cycle assessment was conducted to estimate indirect management‐related GHG emissions. Results show that feedstock supply from wheat straw can be supplemented beneficially with LCB from Miscanthus grown on selected low‐quality soils. In our study, 8% of the less productive arable land area was dedicated to Miscanthus, increasing total LCB provision by about 150%, with a 52% reduction in GHG emission per ton LCB delivered and only a minor effect on wheat grain production (−3%). In conclusion, even without considering the likely carbon sequestration in impoverished soils, agriculture should embrace the opportunities to provide the bioeconomy with LCB from dedicated, perennial crops. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Training and accrediting international surgeons
Authors: Stawicki S P , Nwomeh B C , Peck G L , Sifri Z C , Garg M , Sakran J V , Papadimos T J , Anderson H L , Firstenberg M S , Gracias V H , Asensio J A 
Published: January 2019

AbstractBackgroundFormal international medical programmes (IMPs) represent an evolution away from traditional medical volunteerism, and are based on the foundation of bidirectional exchange of knowledge, experience and organizational expertise. The intent is to develop multidirectional collaborations and local capacity that is resilient in the face of limited resources. Training and accreditation of surgeons continues to be a challenge to IMPs, including the need for mutual recognition of competencies and professional certification.MethodsMEDLINE, Embase and Google Scholar™ were searched using the following terms, alone and in combination: ‘credentialing’, ‘education’, ‘global surgery’, ‘international medicine’, ‘international surgery’ and ‘training’. Secondary references cited by original sources were also included. The authors, all members of the American College of Academic International Medicine group, agreed advice on training and accreditation of international surgeons.Results and conclusionThe following are key elements of training and accrediting international surgeons: basic framework built upon a bidirectional approach; consideration of both high-income and low- and middle-income country perspectives; sourcing funding from current sources based on existing IMPs and networks of IMPs; emphasis on predetermined cultural competencies and a common set of core surgical skills; a decentralized global system for verification and mutual recognition of medical training and certification. The global medical system of the future will require the assurance of high standards for surgical education, training and accreditation.
Scrotal hematoma following femoral artery puncture
Authors: Ishibashi Shun , Sakakura Kenichi , Yamamoto Kei , Okochi Tomohisa , Momomura Shin‐ichi , Fujita Hideo 
Published: January 2019

Key Clinical Message
The scrotum hematoma following femoral artery puncture is a rare complication. The bleeding from the puncture site drained through the inguinal canal into the scrotum. The present case may indicate the importance of quick observation of the scrotum, when the puncture of femoral artery was performed.
Thioesters as Acyl Donors in Biocatalytic Friedel‐Crafts‐type Acylation Catalyzed by Acyltransferase from Pseudomonas Protegens
Authors: Żądło‐Dobrowolska Anna , Schmidt Nina G. , Kroutil Wolfgang 
Published: January 2019

AbstractFunctionalization of aromatic compounds by acylation has considerable significance in synthetic organic chemistry. As an alternative to chemical Friedel‐Crafts acylation, the C‐acyltransferase from Pseudomonas protegens has been found to catalyze C−C bond formation with non‐natural resorcinol substrates. Extending the scope of acyl donors, it is now shown that the enzyme is also able to catalyze C−S bond cleavage prior to C−C bond formation, thus aliphatic and aromatic thioesters can be used as acyl donors. It is worth to mention that this reaction can be performed in aqueous buffer. Identifying ethyl thioacetate as the most suitable acetyl donor, the products were obtained with up to >99 % conversion and up to 88 % isolated yield without using additional base additives; this represents a significant advancement to prior protocols.
Mechanistic Insight into Palladium‐Catalyzed Carbocyclization‐Functionalization of Bisallene: A Computational Study
Authors: Zhang Jing , Shan Chunhui , Lv Kang , Zhu Lei , Li Yuanyuan , Liu Tao , Lan Yu 
Published: January 2019

AbstractDensity functional theory calculations were performed to reveal the mechanisms of Pd‐catalyzed cascade carbocyclization‐borylation and arylation reactions. The computational results indicate that the reactions start with allylic C−H cleavage through concerted metalation‐deprotonation and an intramolecular exo‐type allene insertion to form a six‐membered carbocycle intermediate. The regioselectivity of insertion could be explained by frontier molecular orbital theory and natural population analysis calculation. In the absence of extra nucleophiles, η1/η3‐isomerization followed by acetate‐assisted deprotonation could yield polyene product. When nucleophile was added to the reaction system, transmetalation and subsequent reductive elimination could give the exo‐substituted triene as major product. Meanwhile, η1/η3‐isomerization, transmetalation, and reductive elimination could afford the endo‐isomer as side product. The regioselectivity of further functionalization is controlled by the competition of transmetalation and η1/η3‐isomerization. The computational results show that both exo‐ and endo‐boronation product could be observed when bis(pinacolato)diboron is added as nucleophile. However, only exo‐phenylation product is observed when phenylboronic acid is used as nucleophile because of the high free‐energy barrier for reductive elimination from aryl η3‐allylic palladium.