bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphitic‐Carbon Layers on Oxides: Toward Stable Heterogeneous Catalysts for Biomass Conversion Reactions
Authors: Xiong Haifeng , Schwartz Thomas J. , Andersen Nalin I. , Dumesic James A. , Datye Abhaya K. 
Published: May 2015

AbstractConversion of biomass‐derived molecules involves catalytic reactions under harsh conditions in the liquid phase (e.g., temperatures of 250 °C and possibly under either acidic or basic conditions). Conventional oxide‐supported catalysts undergo pore structure collapse and surface area reduction leading to deactivation under these conditions. Here we demonstrate an approach to deposit graphitic carbon to protect the oxide surface. The heterogeneous catalysts supported on the graphitic carbon/oxide composite exhibit excellent stability (even under acidic conditions) for biomass conversion reactions.
Praktische kontinuierliche Durchfluss‐Abfangmetallierungen funktionalisierter Arene und Heteroarene mit TMPLi in Gegenwart von Mg‐, Zn‐, Cu‐ oder La‐Halogeniden
Authors: Becker Matthias R. , Knochel Paul 
Published: May 2015

AbstractEs wird die Durchflussmetallierung verschiedener Arene und Heteroarene durch In‐situ‐Abfangen mit Metallsalzen (ZnCl2⋅2 LiCl, MgCl2, CuCN⋅2 LiCl, LaCl3⋅2 LiCl) unter sehr zweckmäßigen Bedingungen (0 °C, 40 s) beschrieben. Die entstehenden Mg‐, Zn‐, Cu‐ oder La‐organischen Spezies werden mit verschiedenen Elektrophilen in hohen Ausbeuten abgefangen. In mehreren Fällen werden ungewöhnliche kinetische Regioselektivitäten erzielt. Die Durchflussmetallierungen werden ohne weitere Optimierung schlicht durch Verlängerung der Reaktionszeit skaliert. Verglichen mit den entsprechenden Batch‐Prozessen werden die Anwendungsmöglichkeiten durch solche Flussmetallierungen beträchtlich erweitert.
A Minimal β‐Lactone Fragment for Selective β5c or β5i Proteasome Inhibitors
Authors: Groll Michael , Korotkov Vadim S. , Huber Eva M. , de Meijere Armin , Ludwig Antje 
Published: May 2015

AbstractBroad‐spectrum proteasome inhibitors are applied as anticancer drugs, whereas selective blockage of the immunoproteasome represents a promising therapeutic rationale for autoimmune diseases. We here aimed at identifying minimal structural elements that confer β5c or β5i selectivity on proteasome inhibitors. Based on the natural product belactosin C, we synthesized two β‐lactones featuring a dimethoxybenzyl moiety and either a methylpropyl (pseudo‐isoleucin) or an isopropyl (pseudo‐valine) P1 side chain. Although the two compounds differ only by one methyl group, the isoleucine analogue is six times more potent for β5i (IC50=14 nM) than the valine counterpart. Cell culture experiments demonstrate the cell‐permeability of the compounds and X‐ray crystallography data highlight them as minimal fragments that occupy primed and non‐primed pockets of the active sites of the proteasome. Together, these results qualify β‐lactones as a promising lead‐structure motif for potent nonpeptidic proteasome inhibitors with diverse pharmaceutical applications.
In Situ Microscopic Observation of the Crystallization Process of Molecular Microparticles by Fluorescence Switching
Authors: Ye Xin , Liu Yang , Lv Yun , Liu Guangfeng , Zheng Xiaoxin , Han Quanxiang , Jackson Kenneth A. , Tao Xutang 
Published: May 2015

AbstractTo clearly understand the solid‐state amorphous‐to‐crystalline transformation is a long‐standing challenge because such crystallization occuring in confined environments is difficult to observe directly. We developed an in situ and real‐time imaging procedure to record the interface evolution in a solid‐state crystallization of molecular amorphous particles. The method, by employing a tetra‐substituted ethene with novel morphology‐dependent fluorescence, which can distinguish the interfaces between the crystalline and amorphous phase by fluorescence color, is a simple and practical method to probe the inner process of a molecular microparticle. The crystallization of amorphous microparticles in different cases was clearly recorded, where the perfect microparticles and those with defects demonstrate diverse destinies. The details disclosed in this observation will deepen the understanding for a series of solid‐state crystallization that we know little about before.
Crystallization behavior and mechanical properties of an electrospun ethanol‐mediated poly(ethylene terephthalate) fibrous membrane
Authors: Wang Li‐Na , Wang Yan‐Wei , Liu Wen‐Tao , Xia Xue‐Lian , He Su‐Qin , Liu Hao , Zhu Cheng‐Shen 
Published: May 2015

ABSTRACTA simple approach for preparing electrospun poly(ethylene terephthalate) (PET) fibrous membranes with excellent spinnability and mechanical properties is introduced in this article. To enhance the electrospinnability of PET, a small content of ethanol was incorporated into a 16 wt % PET solution. The effects of ethanol on the solution properties, mechanical properties and crystallization properties and the related morphology were systematically evaluated. The conductivity (κ) measurement indicated that ethanol could obviously improve κ of the PET solution; this correlated well with the morphology of fibers. Scanning electron microscopy images showed that the diameter of the fibers decreased with increasing solution κ. The tensile strength of the PET fibrous membrane increased 1.8 times through the blending of 2.5 vol % ethanol with the PET solution. The differential scanning calorimetry results showed that the crystallinity was improved when the ethanol content increased; this was beneficial to the enhancement of the tensile strength. The glass‐transition temperature and melting temperature increased slightly, but the cold‐crystallization peak shifted to a lower temperature with increasing ethanol content (<3.75 vol %); this was attributed to the increasing in the oriented degree. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42341.
Physical properties and crystallization behavior of poly(lactide)/poly(methyl methacrylate)/silica composites
Authors: Wu Jyh‐Horng , Kuo M. C. , Chen Chien‐Wen 
Published: May 2015

ABSTRACTPoly(lactide)/poly(methyl methacrylate)/silica (PLA/PMMA/SiO2) composites were fabricated using a twin‐screw extruder. Nanosilica particles were incorporated to improve the toughness of the brittle PLA, and a chain extender reagent (Joncryl ADR 4368S) was used to reduce the hydrolysis of the PLA during fabrication. Highly transparent PLA and PMMA were designated to blend to obtain the miscible and transparent blends. To estimate the performance of the PLA/PMMA/SiO2 composites, a series of measurements was conducted, including tensile and Izod impact tests, light transmission and haze measurements, thermomechanical analysis, and isothermal crystallization behavior determination. A chain extender increases the ultimate tensile strength of the PLA/PMMA/SiO2 composites by ∼43%, and both a chain extender and nanosilica particles increase Young's modulus and Izod impact strength of the composites. Including 0.5 wt % nanosilica particles increase the elongation at break and Izod impact strength by ∼287 and 163%, respectively, compared with those of the neat PLA. On account of the mechanical performances, the optimal blending ratio may be between PLA/PMMA/SiO2 (90/10) and PLA/PMMA/SiO2 (80/20). The total light transmittance of the PLA/PMMA/SiO2 composites reaches as high as 91%, indicating a high miscible PLA/PMMA blend. The haze value of the PLA/PMMA/SiO2 composites is less than 35%. Incorporating nanosilica particles can increase the crystallization sites and crystallinities of the PLA/PMMA/SiO2 composites with a simultaneous decrease of the spherulite dimension. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42378.
Preparation and properties of compatible starch‐polycaprolactone composites: Effects of molecular weight of soft segments in polyurethane compatilizer
Authors: Zhang Xu , Zhang Yu , Liao Jingjing , Yu Ting , Hu Rongrong , Wu Zhengshun , Wu Qiangxian 
Published: May 2015

ABSTRACTIn this study, polycaprolactone (PCL)‐diol samples of soft segment with different molecular weights were utilized to synthesiz polyurethane prepolymer (PCLPUP) and was charged in an intensive mixer to prepare starch‐PCLPU‐PCL composites. The impact of the polyurethane soft segments with different molecular weights on the starch‐PCLPI‐PCL composite systems regarding their structure and properties, were thoroughly analyzed. Results showed that the PCLPU successfully increased the interaction between the starch and PCL in the composites, and can thus be used as an effective compatilizer to improve the compatibility between starch and PCL in the resultant composites. With decreasing molecular weight of PCLPU soft segments, the isocyanate group (NCO) content in the PCLPU increased, generating more urethane covalent bonds between PCLPU and starch, thereby enhancing the interaction between starch and PCLPU interface. Again, with decreasing molecular weight of PCLPU soft segments, the physical cross‐linking between the PCLPU and PCL was increased, thereby enhancing the compatibility between PCL matrix and PCLPU interface. Owing to the improvement of compatibility between the starch filler and PCL matrix, the elongation and strength at break for the composite material likewise improved after the addition of PCLPU soft segments with low molecular weight. To this effect, a PCLPU soft segment with low molecular weight was added to the starch‐PCL composites system to boost the overall performance of these starch‐PCL composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42381.
Electrical properties of acrylic resin composite thin films with graphene/silver nanowires
Authors: Wang Xiaoxia , Pang Beili , Zhu Qianqian , Yu Jianhua , Dong Hongzhou , Dong Lifeng 
Published: May 2015

ABSTRACTSilver nanowires and graphene were used to form networks within acrylic resin to improve its toughness and conductivity through silane coupling agent. Meanwhile, acrylic resin was favorable to the adhesion of graphene to glass substrates and the connection among graphene sheets to form films. Experimental results indicate that after annealing at 400°C, sheet resistances of graphene‐silver nanowire films were lower than those graphene films without silver nanowires. The findings in this study provide helpful information on the fabrication of graphene‐based electronic devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42387.
Effect of surfactant and electron treatment on the electrical and thermal conductivity as well as thermal and mechanical properties of ethylene vinyl acetate/expanded graphite composites
Authors: Sefadi Jeremia Shale , Luyt Adriaan Stephanus , Pionteck Jürgen , Piana Francesco , Gohs Uwe 
Published: May 2015

ABSTRACTThis study presents an investigation of the electrical and thermal conductivities of composites based on an ethylene vinyl acetate (EVA) copolymer matrix and nanostructured expanded graphite (EG). To improve the EG dispersion in EVA, EG sheets were modified by treating them with the anionic surfactant sodium dodecyl sulphate (SDS) in water. The modified SDS‐EG platelets, after being filtered and dried, were melt‐mixed with EVA to prepare the composites. Finally, both EVA/EG and EVA/SDS‐EG composites were subjected to 50 kGy electron beam (EB) irradiation. SEM images confirm that the irradiated EVA/EG samples had improved interfacial adhesion, while the irradiated EVA/SDS‐EG samples showed even better interfacial adhesion. The gel contents of the irradiated samples without and with SDS treatment increased with increase in EG loading. The EVA/EG composites exhibited a sharp transition from an insulator to a conductor at an electrical percolation threshold of 8 wt %, but with SDS‐EG the electrical conductivity was extremely low, showing no percolation up to 10 wt % of filler. The EB irradiation had no influence on electrical conductivity. The thermal conductivity linearly increased with EG content, and this increase was more pronounced in the case of SDS‐EG, but decreased after EB irradiation. The thermal properties were little influenced by EB irradiation, while better polymer–filler interaction and better filler dispersion as a result of SDS treatment, and the EB irradiation initiated formation of a cross‐linked network, had a positive effect on the tensile properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42396.
A biomimetic surface treatment to obtain durable omniphobic textiles
Authors: De Marco Carmela , Oldani Valeria , Bianchi Claudia Letizia , Levi Marinella , Turri Stefano 
Published: May 2015

ABSTRACTA bio‐inspired surface treatment to make fabrics omniphobic is reported, exploiting the ability of dopamine – a widespread naturally occurring biological neurotransmitter – to give substrate adhesion and surface immobilization. Standard polyester and polyacrylonitrile fabrics, which are intrinsically rather hydrophilic, are first dip‐coated in an aqueous solution of dopamine and then treated with a fluorocarbon‐based solution. After the treatment, fabrics show a strong omniphobic behavior, while remaining quite permeable to water vapor. The efficiency of the proposed biomimetic treatment is investigated by Optical Contact Angle, Environmental Scanning Electron Microscopy (ESEM), and X‐ray Photoelectron Spectroscopy (XPS). Moreover, the mechanical durability of the surface treatment is tested through Martindale abrasion resistance measurements. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42404.
Silk fibroin composite membranes for application in corneal regeneration
Authors: Zhang Shanshan , Li Jiaojiao , Yin Zhuping , Zhang Xiaofeng , Kundu Subhas C. , Lu Shenzhou 
Published: May 2015

ABSTRACTThe ordered microstructure of the corneal stroma determines the transparency of the cornea. The difficulty of constructing three‐dimensional corneal tissue mainly lies in the reconstruction of the corneal stroma. This article reports propionamide/silk fibroin composite membrane materials for use in corneal regeneration. X‐ray diffraction is used to explore the structure of the composite fibroin membrane. Propionamide acts as a crosslinking agent and inhibits the formation of larger crystal grains controlling the crystallization process. Corneal stromal cells are seeded on sterilized composite films. Propionamide/fibroin membranes with different blending proportions exhibit stable transparency and good cell compatibility. The results demonstrate that composite fibroin membranes are suitable potential materials for use in corneal stromal cell proliferation and repair. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42407.
Differential β3 and β1 Integrin Expression in Bone Marrow and Cortical Bone of Estrogen Deficient Rats
Authors: Voisin Muriel , McNamara Laoise M. 
Published: May 2015

ABSTRACTIntegrin‐based (β3) attachments to the extracellular matrix (ECM) on osteocyte cell processes have recently been proposed to play an important role in facilitating osteocyte mechanosensation. However, it is not yet known whether integrin expression is altered in the mechanoregulatory osteocytes during osteoporosis. The objective of this study was to test the hypothesis that the expression of integrin‐based mechanosensory complexes (β1 and β3 integrins) is altered as a direct response to estrogen deficiency, in an estrogen deficient animal model of osteoporosis. Four weeks post‐operatively, immunohistochemistry was used to detect for β1 and β3 integrin subunits in bone tissue and marrow of ovariectomized (OVX; N = 4) and SHAM (N = 4) operated animals. A tartrate resistant acid phosphatase (TRAP) control stain was performed to quantify the presence of osteoclasts in the bone marrow and bone surfaces. Image analysis was performed to quantify expression patterns in different biological compartments, that is, bone marrow, endosteum, and cortical bone. Our results showed that β1 integrins were ubiquitously expressed throughout the bone and marrow, for both OVX and SHAM groups. β3 integrin subunit expression was lower in bone cells from osteoporotic animals compared to controls, whereas β3 expression in marrow cells did not differ significantly between groups. At the endosteum no difference was observed in β3 integrin subunit expression. As expected, the number of osteoclasts was higher in the OVX group validating an imbalance in bone remodeling. We propose that a reduction in β3 integrin expression in osteocytes might impair mechanosensation by bone cells during estrogen deficiency. Anat Rec, 298:1548–1559, 2015. © 2015 Wiley Periodicals, Inc.
Enzymatic cell disruption of microalgae biomass in biorefinery processes
Authors: Demuez Marie , Mahdy Ahmed , Tomás‐Pejó Elia , González‐Fernández Cristina , Ballesteros Mercedes 
Published: May 2015

ABSTRACTWhen employing biotechnological processes for the procurement of biofuels and bio‐products from microalgae, one of the most critical steps affecting economy and yields is the “cell disruption” stage. Currently, enzymatic cell disruption has delivered effective and cost competitive results when compared to mechanical and chemical cell disruption methods. However, the introduction of enzymes implies additional associated cost within the overall process. In order to reduce this cost, autolysis of microalgae is proposed as alternative enzymatic cell disruption method. This review aims to provide the state of the art of enzymatic cell disruption treatments employed in biorefinery processes and highlights the use of endopeptidases. During the enzymatic processes of microalgae life cycle, some lytic enzymes involved in cell division and programmed cell death have been proven useful in performing cell lysis. In this context, the role of endopeptidases is emphasized. Mirroring these natural events, an alternative cell disruption approach is proposed and described with the potential to induce the autolysis process using intrinsic cell enzymes. Integrating induced autolysis within biofuel production processes offers a promising approach to reduce overall global costs and energetic input associated with those of current cell disruption methods. A number of options for further inquiry are also discussed. Biotechnol. Bioeng. 2015;112: 1955–1966. © 2015 Wiley Periodicals, Inc.
Systematic review of cardiovascular disease and cardiovascular death in patients with a small abdominal aortic aneurysm
Authors: Bath M F , Gokani V J , Sidloff D A , Jones L R , Choke E , Sayers R D , Bown M J 
Published: May 2015

Abstract

Background
Screening for abdominal aortic aneurysm (AAA) has reduced the rate of AAA rupture. However, cardiovascular disease is still a major cause of death in men with an AAA. The aim of this study was to assess cardiovascular risk in patients with a small AAA.

Methods
Standard PRISMA guidelines were followed. Analysis was performed of studies reporting cardiovascular outcomes in patients with a small AAA (30–54 mm). Weighted metaregression was performed for cardiovascular death in patients with a small AAA, and the prevalence of cardiovascular disease was reviewed.

Results
Twenty-one articles were identified describing patients with an AAA, and the prevalence of, and death from, cardiovascular disease. Ten of these reported cardiovascular death rates in patients with a small AAA. Some 2323 patients with a small AAA were identified; 335 cardiovascular deaths occurred, of which 37 were due to AAA rupture. Metaregression demonstrated that the risk of cardiovascular death was 3·0 (95 per cent c.i. 1·7 to 4·3) per cent per year in patients with a small AAA (R2 = 0·902, P &lt; 0·001). The prevalence of ischaemic heart disease (44·9 per cent), myocardial infarction (26·8 per cent), heart failure (4·4 per cent) and stroke (14·0 per cent) was also high in these patients.

Conclusion
The risk of cardiovascular death in patients with a small AAA is high and increases by approximately 3 per cent each year after diagnosis. Patients with a small AAA have a high prevalence of cardiovascular disease. Patients a small AAA should be considered for lifestyle modifications and secondary cardiovascular protection.
Frozen moments: flashback memories of critical incidents in emergency personnel
Authors: Kleim Birgit , Bingisser Martina‐Barbara , Westphal Maren , Bingisser Roland 
Published: May 2015

AbstractBackgroundEmergency Department personnel regularly face highly stressful situations or critical incidents (CIs) that may subsequently be recalled as unbidden intrusive memories. In their most extreme form, such memories are reexperienced as if they were happening again in the present, as flashbacks. This study examined (1) which CIs are associated with flashback memories; (2) candidate person and work‐related features that predict flashback memories; and (3) the association between flashback memories and anxiety, depression, and emotional exhaustion.MethodsEmergency nurses (N = 91; 80.2% female) were recruited from two urban teaching hospitals and filled in self‐report questionnaires.ResultsA majority (n = 59, 65%) experienced intrusive memories; almost half of the sample reported that their memories had flashback character. Those involved in resuscitations in the past week were at a fourfold risk for experiencing flashbacks. Having worked more consecutive days without taking time off was associated with a somewhat lower incidence of flashbacks. Moreover, older individuals who reported more work‐related conflicts were at greater risk for experiencing flashback memories than their younger colleagues with heightened work conflict and flashback memory scores, respectively. Flashback memories were associated with heightened symptoms of anxiety, depression, and emotional exhaustion.ConclusionsThe present findings have implications for evidence‐based health promotion in emergency personnel and other individuals regularly exposed to CIs.
Identifying Etiologically Distinct Sub‐Types of Cancer: A Demonstration Project Involving Breast Cancer
Authors: Begg Colin B. , Orlow Irene , Zabor Emily C. , Arora Arshi , Sharma Ajay , Seshan Venkatraman E. , Bernstein Jonine L. 
Published: May 2015

AbstractWith the advent of increasingly detailed molecular portraits of tumor specimens, much attention has been directed toward identifying clinically distinct subtypes of cancer. Subtyping of tumors can also be accomplished with the goal of identifying distinct etiologies. We demonstrate the use of new methodologies to identify genes that distinguish etiologically heterogeneous subtypes of breast cancer using data from the case–control Cancer and Steroid Hormone Study. Tumor specimens were evaluated using a breast cancer expression panel of 196 genes. Using a statistical measure that distinguishes the degree of etiologic heterogeneity in tumor subtypes, each gene is ranked on the basis of its ability to distinguish etiologically distinct subtypes. This is accomplished independently using case–control comparisons and by examining the concordance odds ratios in double primaries. The estrogen receptor gene, and others in this pathway with expression levels that correlated strongly with estrogen receptor levels, demonstrate high degrees of etiologic heterogeneity in both methods. Our results are consistent with a growing literature that confirms the distinct etiologies of breast cancers classified on the basis of estrogen receptor expression levels. This proof‐of‐principle project demonstrates the viability of new strategies to identify genomic features that distinguish subtypes of cancer from an etiologic perspective.