bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Model of Time–Temperature Superposition Principle of the Self‐Healing Kinetics of Supramolecular Polymer Nanocomposites
Authors: Zheng Zijian , Xia Xiuyang , Zeng Xianxiang , Li Xiu , Wu Youping , Liu Jun , Zhang Liqun 
Published: August 2018

AbstractThe matrix‐free polymer nanocomposites (PNCs) formed by polymer‐grafted nanoparticles(NPs) gain enormous attention due to their controllable morphology and robust properties. Herein, through molecular dynamics simulation, such PNCs are successfully constructed, and the dispersion state of the NPs can be tailored by varying the grafting density. By manipulating the interaction strength between the end groups of the grafted polymer chains, the tensile fracture behavior and the chain orientation are examined. It is revealed that both of them fall down at large strain because of the propagation of the cavities. By probing the self‐healing kinetics at various self‐healing temperature and time, a time−temperature superposition principle, similar to the Williams, Landel and Ferry equation, is proposed. These results could provide some fundamental guidelines for the design and fabrication of high performance PNCs with excellent self‐healing functionality.
Experimental Methods for Characterizing the Secondary Structure and Thermal Properties of Silk Proteins
Authors: McGill Meghan , Holland Gregory P. , Kaplan David L. 
Published: August 2018

AbstractSilk proteins are biopolymers produced by spinning organisms that have been studied extensively for applications in materials engineering, regenerative medicine, and devices due to their high tensile strength and extensibility. This remarkable combination of mechanical properties arises from their unique semi‐crystalline secondary structure and block copolymer features. The secondary structure of silks is highly sensitive to processing, and can be manipulated to achieve a wide array of material profiles. Studying the secondary structure of silks is therefore critical to understanding the relationship between structure and function, the strength and stability of silk‐based materials, and the natural fiber synthesis process employed by spinning organisms. However, silks present unique challenges to structural characterization due to high‐molecular‐weight protein chains, repetitive sequences, and heterogeneity in intra‐ and interchain domain sizes. Here, experimental techniques used to study the secondary structure of silks, the information attainable from these techniques, and the limitations associated with them are reviewed. Ultimately, the appropriate utilization of a suite of techniques discussed here will enable detailed characterization of silk‐based materials, from studying fundamental processing–structure–function relationships to developing commercially useful quality control assessments.
Aggregate‐Induced Self‐Assembly and Ultrafast Dynamics of Light‐Harvesting D‐A‐A Polymorphs
Authors: Carlino Thomas M. , Hu Qiaoyu , Scott Amy M. 
Published: August 2018

AbstractOrganic dipolar molecules are an emerging class of light harvesters useful in electronic applications and have captured new urgency with the design and synthesis of new molecular structures for device testing. However, research has not evolved beyond the cyclical thin film preparation—device testing—chemical structural modification approach. Without an understanding of polymorphism, molecular photophysics at the interface or metastable morphologies that regulate charge carrier dynamics, it is not obvious a priori if a new molecular structure will produce a suitable thin film morphology for superior device performance without developing structure–function relationships that consider morphology and photophysics. Dipolar, light harvesting molecules are synthesized with a covalent, para‐functionalized triphenylamine donor (D) and acceptor (A) in π‐conjugated structures, D–A1 and D–A1–A2, that have previously achieved 9.6% power conversion efficiency in thermally evaporated organic solar cell devices with C70. Solution processing and morphological manipulation are hypothesized to reduce ultrafast radiative charge recombination, unique to dipolar structures, that prevents full charge separation to the fullerene. The photophysics of the D–A interface using femtosecond transient absorption spectroscopy is explained, and microscopy data reveal a newly discovered, supramolecular amorphous polymer metastable state presented as a transient absorption assisted strategy for photofunctional polymorph design.
Highly Luminescent Ladderized Fluorene Copolymers Based on B–N Lewis Pair Functionalization
Authors: Alahmadi Abdullah F. , Lalancette Roger A. , Jäkle Frieder 
Published: August 2018

AbstractA new B–N functionalized polyaromatic building block for conjugated hybrid polymers is developed. Bromine‐functionalized dipyridylfluorene is first subjected to Lewis‐base‐directed electrophilic borylation and subsequently incorporated into conjugated polymers via transition‐metal‐catalyzed cross‐coupling reactions. The borane monomer exhibits bright blue luminescence in solution, as a result of the rigid ladder‐type structure generated upon electrophilic borylation. Yamamoto coupling gives rise to a homopolymer and Stille coupling to a vinylene‐bridged copolymer. Polymerization of the BN‐fused ladder molecules leads to large bathochromic shifts in absorption and emission, which are most pronounced for the vinylene‐bridged copolymer. The polymers display strong luminescence in solution with quantum yields of 55% and 78% and sub‐ns fluorescence lifetimes; the copolymer also exhibits bright yellow luminescence in the solid state when precipitated from solution.
Erythropoiesis and chronic kidney disease–related anemia: From physiology to new therapeutic advancements
Authors: Cernaro Valeria , Coppolino Giuseppe , Visconti Luca , Rivoli Laura , Lacquaniti Antonio , Santoro Domenico , Buemi Antoine , Loddo Saverio , Buemi Michele 
Published: August 2018

AbstractErythropoiesis is triggered by hypoxia and is strictly regulated by hormones, growth factors, cytokines, and vitamins to ensure an adequate oxygen delivery to all body cells. Abnormalities in one or more of these factors may induce different kinds of anemia requiring different treatments. A key player in red blood cell production is erythropoietin. It is a glycoprotein hormone, mainly produced by the kidneys, that promotes erythroid progenitor cell survival and differentiation in the bone marrow and regulates iron metabolism. A deficit in erythropoietin synthesis is the main cause of the normochromic normocytic anemia frequently observed in patients with progressive chronic kidney disease. The present review summarizes the most recent findings about each step of the erythropoietic process, going from the renal oxygen sensing system to the cascade of events induced by erythropoietin through its own receptor in the bone marrow. The paper also describes the new class of drugs designed to stabilize the hypoxia‐inducible factor by inhibiting prolyl hydroxylase, with a discussion about their metabolism, disposition, efficacy, and safety. According to many trials, these drugs seem able to simulate tissue hypoxia and then stimulate erythropoiesis in patients affected by renal impairment. In conclusion, the in‐depth investigation of all events involved in erythropoiesis is crucial to understand anemia pathophysiology and to identify new therapeutic strategies, in an attempt to overcome the potential side effects of the commonly used erythropoiesis‐stimulating agents.
Neurectomy preserves fast fibers when combined with tenotomy of infraspinatus muscle via upregulation of myogenesis
Authors: Flück Martin , Valdivieso Paola , Ruoss Severin , von Rechenberg Brigitte , Benn Mario C. , Meyer Dominik C. , Wieser Karl , Gerber Christian 
Published: August 2018

ABSTRACTIntroduction: We evaluated the contribution of denervation‐related molecular processes to rotator cuff muscle degeneration after tendon release. Methods: We assessed the levels of myogenic (myogenin and myogenic differentiation factor [myoD]) and proadipogenic (peroxisome proliferator‐activated receptor γ) transcription factors; the denervation‐associated proteins tenascin‐C, laminin‐2, and calcium/calmodulin‐dependent kinase II (CaMKII); and cellular alterations in sheep after infraspinatus tenotomy (TEN), suprascapular neurectomy (NEU), or both (TEN‐NEU). Results: Extracellular ground substance increased at the expense of contractile tissue 16 weeks after surgery, correlating with CaMKII isoform levels. Sheep undergoing NEU and TEN‐NEU had exaggerated infraspinatus atrophy and increased fast fibers compared with TEN sheep. The βMCaMKII isoform levels increased with TEN, and myoD levels tripled after denervation and were associated with slow fibers. Discussion: In sheep, denervation did not affect muscle‐to‐fat conversion after TEN of the infraspinatus. Furthermore, concurrent NEU mitigated the loss of fast fibers after TEN by inducing a fast‐contractile phenotype. Muscle Nerve 59:100–107, 2019
A multilevel FETI‐DP method and its performance for problems with billions of degrees of freedom
Authors: Toivanen Jari , Avery Philip , Farhat Charbel 
Published: August 2018

SummaryA multilevel generalization of the dual‐primal finite element tearing and interconnecting (FETI‐DP) domain decomposition method is proposed for very large‐scale discrete problems to address the bottleneck associated with the solution of the coarse problems at such scales. This bottleneck destroys the parallel scalability of the original, two‐level FETI‐DP method when using more than a few thousand processor cores. In the multilevel formulation proposed here, the FETI‐DP method is applied recursively to solve all coarse problems but the smallest one. Crucially, this recursive application of the method is enabled by utilizing a new primal formulation of the augmentation/enrichment process of the coarse problems. The efficiency and scalability of the proposed approach are demonstrated for up to 32 768 processor cores, and large‐scale real‐world and benchmark problems with more than 21 billion degrees of freedom. The obtained performance results show that the three‐ and four‐level FETI‐DP methods exhibit a better scalability than the original two‐level FETI‐DP method.
Excessive dietary lipid intake provokes an acquired form of lysosomal lipid storage disease in the kidney
Authors: Rampanelli Elena , Ochodnicky Peter , Vissers Johannes PC , Butter Loes M , Claessen Nike , Calcagni Alessia , Kors Lotte , Gethings Lee A , Bakker Stephan JL , de Borst Martin H , Navis Gerjan J , Liebisch Gerhard , Speijer Dave , van den Bergh Weerman Marius A , Jung Bettina , Aten Jan , Steenbergen Eric , Schmitz Gerd , Ballabio Andrea , Florquin Sandrine , Aerts Johannes MFG , Leemans Jaklien C 
Published: August 2018

AbstractObesity and dyslipidaemia are features of the metabolic syndrome and risk factors for chronic kidney disease. The cellular mechanisms connecting metabolic syndrome with chronic kidney disease onset and progression remain largely unclear. We show that proximal tubular epithelium is a target site for lipid deposition upon overnutrition with a cholesterol‐rich Western‐type diet. Affected proximal tubule epithelial cells displayed giant vacuoles of lysosomal or autophagosomal origin, harbouring oxidised lipoproteins and concentric membrane layer structures (multilamellar bodies), reminiscent of lysosomal storage diseases. Additionally, lipidomic analysis revealed renal deposition of cholesterol and phospholipids, including lysosomal phospholipids. Proteomic profiles of renal multilamellar bodies were distinct from those of epidermis or lung multilamellar bodies and of cytoplasmic lipid droplets. Tubular multilamellar bodies were observed in kidney biopsies of obese hypercholesterolaemic patients, and the concentration of the phospholipidosis marker di‐docosahexaenoyl (22:6)‐bis(monoacylglycerol) phosphate was doubled in urine from individuals with metabolic syndrome and chronic kidney disease. The enrichment of proximal tubule epithelial cells with phospholipids and multilamellar bodies was accompanied by enhanced inflammation, fibrosis, tubular damage markers, and higher urinary electrolyte content. Concomitantly to the intralysosomal lipid storage, a renal transcriptional response was initiated to enhance lysosomal degradation and lipid synthesis. In cultured proximal tubule epithelial cells, inhibition of cholesterol efflux transport or oxysterol treatment induced effects very similar to the in vivo situation, such as multilamellar body and phospholipid amassing, and induction of damage, inflammatory, fibrotic, and lipogenic molecules. The onset of phospholipidosis in proximal tubule epithelial cells is a novel pathological trait in metabolic syndrome‐related chronic kidney disease, and emphasises the importance of healthy lysosomes and nutrition for kidney well‐being. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Psychological risk in long‐term survivors of childhood acute lymphoblastic leukemia and its association with functional health status: A PETALE cohort study
Authors: Anestin Annélie S. , Lippé Sarah , Robaey Philippe , Bertout Laurence , Drouin Simon , Krajinovic Maja , Michon Bruno , Rondeau Émélie , Samoilenko Mariia , Laverdière Caroline , Sinnett Daniel , Sultan Serge 
Published: August 2018

AbstractBackgroundRecent research has suggested that long‐term pediatric cancer survivors were at risk of important physical and psychological morbidities. To date, we do not know to what extent functional health status contributes to psychological risk and which domains are most important. The aim of this study was to systematically explore which functional domain could explain anxiety, depression, and distress symptoms.ProcedureWe used data available for 105 adolescents and 182 adults successfully treated for childhood acute lymphoblastic leukemia at two Canadian sites part of the PETALE cohort. Participants were ≥5 years postdiagnosis, aged 22 ± 6 years, 52% female, and 49% acute lymphoblastic leukemia high‐risk status. The contribution of health functional status (15D/16D questionnaires) to self‐reported anxiety, depression, and distress (Beck scales and distress thermometer) was evaluated using adjusted logistic regression models.ResultsPrevalence rates found for mild–severe anxiety, depression, and distress were 14%, 21%, and 30% among adolescents and 27%, 20%, and 19% among adults. Frequent health domains associated with psychological risk were sleeping and breathing in adolescents, and vitality/fatigue, discomfort/symptoms, mental function, and sleeping in adults. Mental function was systematically associated with psychological risk across age groups (median OR = 10.00, 95% CI 3.01–33.71). Exploratory mediation bootstrapping analyses suggested that the effect on psychological risk of overall health status and mental function problems was partly explained by social/work/school functioning.ConclusionThe results identified important functional health domains that could be targeted for interventions preventing psychological risk: vitality/fatigue, discomfort/symptoms, sleeping, and mental function issues. Health domains probably affect mood partly by limiting social/work/school functioning.
“They've got a lot of needs and I don't think they're being met fully”: A qualitative study of the multi‐professional team approach to the management of children with optic pathway gliomas
Authors: Sturgess Benjamin , Brown Morven , Fraser Faye , Bailey Simon 
Published: August 2018

AbstractBackgroundOptic pathway gliomas (OPGs) are low‐grade tumours of the visual pathway. Although survival rates are high, there is considerable morbidity and hence treatment focuses on preservation of vison and quality of life. The multiple, complex issues faced by these patients are often confounded by a concurrent diagnosis of neurofibromatosis type‐1 (NF1). As there is a paucity of literature addressing the current practices of the multi‐professional team (MPT) caring for children diagnosed with an OPG, individual professional experiences often guide the MPT's approach to the care of these children and their families.AimsThis study aimed to gain views on the management of children with OPGs, from MPT members involved in their care, in order to inform recommendations on how to improve the service offered to these children and their families.MethodsA qualitative design collected experiential data from MPT members via semi‐structured interviews. MPT focus groups were used to validate the data.ResultsData collected from 20 MPT members resulted in the overarching themes of Issues Faced by the Patient and Family and Challenges to the Holistic Care of the Patient. Four recommendations are suggested, namely (1) the production of an MPT training resource, (2) improved visual team links, (3) an OPG patient passport and (4) a joint NF1‐OPG clinic.ConclusionThere are many challenges to MPT members providing holistic care to patients with OPGs. As no OPG clinical practice guidelines currently exist, it is suggested that the above recommendations be piloted with evaluation to validate their use.
Tramadol use in Norway: A register‐based population study
Authors: Birke Hanne , Ekholm Ola , Sjøgren Per , Fredheim Olav , Clausen Thomas , Skurtveit Svetlana 
Published: August 2018

AbstractPurposeIncreasing use of tramadol for chronic non‐cancer pain is concerning since tramadol users may be at risk of developing recurrent opioid use with increasing opioid consumption and co‐medication. Therefore, we investigated a complete national cohort of tramadol users.MethodsThe study population (154 042 adult individuals in Norway, who redeemed ≥ one tramadol prescription in 2012) was stratified into four groups according to their opioid use 2 years before their first tramadol prescription in 2012 and followed until 2016. Information on all dispensed opioid analgesics, benzodiazepines (BZDs), and BZD‐related Z‐hypnotics were retrieved from the Norwegian Prescription Database.ResultsSix percent of opioid naïve tramadol users (no opioid use 2 years before tramadol use in 2012) became recurrent users (received opioids annually during 4‐year follow‐up), almost doubled their mean opioid consumption (66 to 108 defined daily doses [DDD]). One‐quarter proceeded to strong opioids or was co‐medicated with BZDs, one‐third with Z‐hypnotics. Among former weak opioid users, 39.8% became recurrent users, 18.7% proceeded to strong opioids, mean opioid consumption increased slightly, one‐third used BZDs, or Z‐hypnotics concurrently. Among former strong opioid and users in palliative care; 61%, 70% became recurrent users and developed a similar prescription pattern (high and increasing mean opioid consumption, 301 to 318, 413 to 430 DDD); half of them proceeded to strong opioids and/or used BZDs or Z‐hypnotics concurrently.ConclusionsMany patients who developed recurrent opioid use received prescriptions which substantially conflicted with existing guidelines and might lead to problematic opioid use.
Computational and experimental insights into the oxidative stability of iron porphyrins: A mono‐ortho‐substituted iron porphyrin with unusually high oxidative stability
Authors: Khazaei Saeede , Eskandari Mortaza , Zakavi Saeed 
Published: August 2018

AbstractThe oxidative stability of iron(III) meso‐tetraarylporphyrins in oxidation of styrene with periodate decreased in the order FeT(2‐Me)PPOAc > > FeT(2‐Cl)PPOAc > FeTPPOAc > FeT(4‐OMe)PPOAc. While the observed order correlates approximately with the electron deficiency of the porphyrin ligands, FeT(2‐Me)PPOAc showed an unusually high stability (99.1% in 120 minutes) under reaction conditions. It is noteworthy that due to the presence of bulky and electronegative chlorine atoms at the ortho positions of FeT(2‐Cl)PPOAc, a higher or at least comparable oxidative stability was expected for FeT(2‐Cl)PPOAc. The energy, electronic, and structural features obtained from spin‐unrestricted hybrid density functional theory‐based calculations showed the involvement of steric and electronic effects as the main factors determining the oxidative stability of iron porphyrins. In the case of FeT(2‐Me)PPOAc, the steric bulk of methyl substituents as well as the large dihedral angle between the aryl substituents and porphyrin mean plane seem to play crucial roles in the observed oxidative stability.
The effect of light penetration depth on the LCST phase behavior of a thermo‐ and photoresponsive statistical copolymer in an ionic liquid
Authors: Hall Cecilia C. , Rivera Cecelia A. , Lodge Timothy P. 
Published: August 2018

ABSTRACTA reflection cloud point technique allows for rapid screening of light‐dependent phase separation temperatures of thermo‐ and photoresponsive polymer/ionic liquid solutions as a function of sample thickness, molecular weight, and copolymer composition. We systematically investigate the lower critical solution temperature (LCST) phase behavior of poly(benzyl methacrylate‐stat‐(4‐phenylazophenyl methacrylate)). Under UV light, the photoresponsive azobenzene‐based repeat unit becomes more polar as the cis form dominates, increasing its solubility in the ionic liquids 1‐ethyl‐3‐methyl imidazolium and 1‐butyl‐3‐methyl imidazolium bis(trifluoromethanesulfonyl)imide. This light‐dependent polarity change leads to two phase separation temperatures, depending on the illumination wavelength. Under visible light, which drives the azobenzene moiety into the trans ground state, the LCST shows no sample thickness dependence. Under UV light, however, sample thickness plays a significant role. Samples of around 1 mm thickness show no apparent difference under UV and visible light, whereas thinner samples show an increasing difference between the phase separation temperatures with decreasing sample thickness. Neither phase separation temperature exhibits a significant dependence on molecular weight. Increasing the photoresponsive monomer content did not lead to an increase in the difference between the phase separation temperatures at fixed thickness, due to a concomitant increase in UV light absorbed at the sample surface. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 281–287
Superhydrophobic Polypropylene Surfaces Prepared with TiO2 Nanoparticles Functionalized by Dendritic Polymers
Authors: Contreras Cintia B. , Figueroa Francisco N. , Weibel Daniel E. , Strumia Miriam C. 
Published: August 2018

ABSTRACTHybrid inorganic–organic nanomaterials have received increasing interest due to the possibility of implementing different functions and characteristics within a single material. Their functionalities are a consequence of the synergy of the properties of distinct building blocks and are related to their varied natures and spatial locations. In this work, we present the development of superhydrophobic properties on polypropylene (PP) surfaces using hybrid nanomateriales from TiO2 nanoparticles (NPs) and dendronized polymers. The dendron acryl Behera's amine was successfully grafted on the TiO2 NP surfaces by Surface‐Initiated Atom Transfer Radical Polymerization (SI‐ATRP) and a core‐brush material was obtained. Finally, PP substrates were coated with NP hybrids to produce superhydrophobic surfaces with water contact angles of over 158 degrees. Controlling the organic silane concentration on the TiO2 NPs allowed the dendronized process to be driven and thereby permitted the selection of specific wettability properties on PP substrate surfaces with high water adhesion or self‐cleaning conditions. This dendronized effect with consequent steric congestion of the polymeric brushes on the NPs changed their behaviors from Wenzel to the Cassie Baxter state. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2019–2029