bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns and clinical consequences of discontinuing HIV preexposure prophylaxis during primary care
Authors: Krakower Douglas , Maloney Kevin M , Powell Victoria E , Levine Ken , Grasso Chris , Melbourne Kathy , Marcus Julia L , Mayer Kenneth H
Published: February 2019

Introduction

Discontinuations of HIV preexposure prophylaxis (PrEP) by at‐risk individuals could decrease the effectiveness of PrEP. Our objective was to characterize patterns of, reasons for, and clinical outcomes associated with PrEP discontinuations in primary care.

Methods

We conducted medical chart reviews for patients prescribed PrEP during 2011 to 2014 at a Boston community health centre specializing in healthcare for sexual and gender minorities. Patients were followed through 2015. We characterized patients’ sociodemographics, relationship status, behavioural health conditions, patterns of and reasons for PrEP discontinuations, and HIV seroconversions. Cox proportional hazards models were used to assess patient factors associated with PrEP discontinuations.

Results

Of the 663 patients prescribed PrEP, the median age was 33 years, 96% were men who have sex with men (MSM) and 73% were non‐Hispanic white; 40% were in committed relationships and 15% had HIV‐infected partners. Patients either used PrEP continuously (60%), had 1 or more discontinuations (36%), or did not initiate PrEP (4%). Discontinuations were most often due to a decrease in HIV risk perception (33%), non‐adherence to care plans (16%), or insurance barriers (12%). Of the 7 (1.1%) PrEP patients diagnosed with HIV, 1 was HIV‐infected at baseline, 2 seroconverted while using PrEP, and 4 seroconverted after discontinuations. In a multivariable model adjusted for race/ethnicity, relationship status, substance use disorders, and insurance status, those who were less than 30 years old (aHR 2.0, 95% CI 1.4 to 2.9 for ages 18 to 24, aHR 2.2, 95% CI 1.6 to 3.1 for ages 25 to 29, vs. ages 30 to 39 years), who identified as transgender women (aHR 2.0, 95% CI 1.2 to 3.4, vs. cisgender men), and who had mental health disorders (aHR 1.2, 95% CI 1.1 to 1.4 for each additional disorder) were more likely to have discontinuations.

Conclusions

Discontinuations of PrEP use among this American sample of predominately MSM were common, particularly among patients who were younger, identified as transgender women, or had behavioural health issues. As HIV seroconversions occurred after discontinuations of PrEP, strategies to prevent inappropriate discontinuations are needed.
New insights into human lysine degradation pathways with relevance to pyridoxine‐dependent epilepsy due to antiquitin deficiency
Authors: Crowther Lisa M. , Mathis Déborah , Poms Martin , Plecko Barbara
Published: February 2019

Deficiency of antiquitin (ATQ), an enzyme involved in lysine degradation, is the major cause of vitamin B6‐dependent epilepsy. Accumulation of the potentially neurotoxic α‐aminoadipic semialdehyde (AASA) may contribute to frequently associated developmental delay. AASA is formed by α‐aminoadipic semialdehyde synthase (AASS) via the saccharopine pathway of lysine degradation, or, as has been postulated, by the pipecolic acid (PA) pathway, and then converted to α‐aminoadipic acid by ATQ. The PA pathway has been considered to be the predominant pathway of lysine degradation in mammalian brain; however, this was refuted by recent studies in mouse. Consequently, inhibition of AASS was proposed as a potential new treatment option for ATQ deficiency. It is therefore of utmost importance to determine whether the saccharopine pathway is also predominant in human brain cells. The route of lysine degradation was analyzed by isotopic tracing studies in cultured human astrocytes, ReNcell CX human neuronal progenitor cells and human fibroblasts, and expression of enzymes of the two lysine degradation pathways was determined by Western blot. Lysine degradation was only detected through the saccharopine pathway in all cell types studied. The enrichment of 15N‐glutamate as a side product of AASA formation through AASS furthermore demonstrated activity of the saccharopine pathway. We provide first evidence that the saccharopine pathway is the major route of lysine degradation in cultured human brain cells. These results support inhibition of the saccharopine pathway as a new treatment option for ATQ deficiency.
Tricarboxylic acid cycle metabolites in the control of macrophage activation and effector phenotypes
Authors: Noe Jordan T , Mitchell Robert A
Published: February 2019

The tricarboxylic acid (TCA) cycle is a mitochondrial metabolic hub that coordinates the metabolism of carbohydrates, proteins, and fats into carbon dioxide and ATP. At specific points in the cycle, the diversion, import, or export of TCA metabolites allows for the dynamic regulation of a variety of tissue and/or cell-specific phenotypic processes. Recent studies have identified that a number of TCA metabolites are important in controlling monocyte/macrophage phenotypes and effector functions while specific macrophage activation or polarization states functionally determine the relative utilization of each. This review focuses on the metabolic reprogramming of the TCA cycle in macrophages and how individual metabolites play a variety of context-specific roles in determining physiologic and pathologic macrophage activation and homeostatic functions. We discuss the implications of these findings and address unanswered questions regarding the role of the TCA cycle in guiding macrophage-dependent immune responses.
Early meteorological data in southern Spain during the Dalton Minimum
Authors: Rodrigo Fernando S.
Published: February 2019

The objective of this work is to present new meteorological data from southern Spain corresponding to the period 1785–1830. Data sources are early newspapers and medical studies interested in the influence of environment conditions on health and illness. Data correspond to five cities in the area (Cádiz, Seville, Málaga, Granada, and Cartagena). Around 16,000 new meteorological observations (temperature, pressure, number of rainy days, wind direction, and qualitative statements on rainfall, wind force, cloudiness, fog, and storms) were recorded. Database obtained is a set of scattered meteorological series, with short periods of observation, fragmented and with no homogeneous characteristics. However, these data may offer an overview on the climatic conditions in the area during the studied period, as well as interesting information on extreme events, as for instance floods in the 1780s decade, and the so‐called “year without summer” 1816.
Fermentation product with new equol‐producing Lactobacillus paracasei as a probiotic‐like product candidate for prevention of skin and intestinal disorder
Authors: Kwon Jeong Eun , Lim Jaewon , Bang Ina , Kim Inhye , Kim Donghyuk , Kang Se Chan
Published: February 2019

BACKGROUND

Equol is a major isoflavone metabolite, and equol‐producing bacteria have been isolated and characterized; however, fermentation has been performed with soybean‐based products as substrates. Pueraria lobata has been reported as a plant with higher content of isoflavones.

RESULTS

The genome of new equol‐producing bacteria, Lactobacillus paracasei JS1, was analyzed. Also, the effect of P. lobata extract fermented with L. paracasei JS1 (FPE) on the skin and intestinal immune response was examined. With gene expression analysis, it was proven that seven skin‐related proteins, hyaluronan synthase‐1, ‐2, ‐3, collagen, elastin, epidermal growth factor, and epidermal growth factor receptor were differentially expressed upon FPE treatment. The messenger RNA expression increased with treatment with the FPE, and a skin moisturizing effect was confirmed by a hematoxylin–eosin staining experiment. In addition, such an experiment showed that proinflammatory cytokines, tumor necrosis factor‐α, cyclooxygenase‐2, inducible nitric oxide synthase, interleukin‐1β, ‐4, and ‐6, were reduced in large intestine when treated with FPE.

CONCLUSION

L. paracasei JS1 has the ability to produce equol having beneficial effects on the skin. Moreover, FPE also has an inhibitory effect on inflammation cytokines in the large intestine. Thus, the novel and edible equol‐producing L. paracasei JS1 and FPE have thepotential to be developed as nutricosmetic resources. © 2019 Society of Chemical Industry
The impact of self‐concept and place attachment on migrants' travel
Authors: Yankholmes Aaron , McKercher Bob
Published: February 2019

This study links self‐concept and place attachment to generate a better understanding of travel behavior patterns by migrant populations, in this case, Western professional migrants who live in the Hong Kong and Macau Special Administrative Regions of China. Five discrete Western professional migrant groups are identified, each with different demographic profiles, travel patterns, propensity, and intensity. The findings challenge the view that migrant populations are homogenous and also challenge the widely held notion that home return travel is their dominant mobility pattern. Conceptual and managerial implications of migrant travel behavior for destination marketers are briefly outlined.
Tannin of Acacia mearnsii as green corrosion inhibitor for AA7075‐T6 alluminum alloy in acidic medium
Authors: Guedes Letícia A. L. , Bacca Katryanne G. , Lopes Natália F. , da Costa Eleani M.
Published: February 2019

The inhibition performance of Acacia mearnsii bark tannin was investigated as eco‐friendly green inhibitor on the corrosion of AA7075‐T6 aluminum alloy in 0.1 M HCl solution by potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS) and scanning electron microcopy (SEM). Polarization curves showed that this tannin acts predominantly as a cathodic inhibitor. High corrosion inhibition performance was achieved with inhibition efficiencies of 95% and 97% at 14 g L−1 as obtained by polarization and EIS electrochemical techniques, respectively. The SEM images revealed that localized attack initiated at intermetallic particles causing local dissolution of the matrix due to potential differences between them. EIS results and SEM images confirmed the protection of AA7075‐T6 aluminum alloy by A. mearnsii bark tannin, evidencing the formation of an adsorbed film on the metal surface that attenuate the aluminum dissolution reaction.
Synthesis and Characterization of Poly(3‐Hexylthiophene) for Organic Solar Cells
Authors: Silva Santos Bianca Pedroso , Rubio Arias Jose Jonathan , de Fátima Vieira Marques Maria , de Melo Furtado Jose Geraldo , Silva Luiz Alberto , Simão Renata Antoun
Published: February 2019

Poly(3‐hexylthiophene) (P3HT) has been successfully synthesized through McCullough route. The influence of nickel catalyst content on molar mass (Mn and Mw), dispersity (Đ), regioregularity (rr), as well as optical, thermal, and morphological properties is systematically investigated. The results evidence that polymer dispersities are narrow, Mn and rr values decrease with the augmentation of catalyst content. Polymer solution in different solvents (chloroform and dichlorobenzene) show similar optical band gaps. Solid state band gap of obtained material is lower than in solution, which confirms the reorganization of polymer chains in solid state. Both polymers show good thermal stability and their morphologies are tightly influenced by the monomer/catalyst ratio in the synthesis. Two main morphologies are obtained, for the higher molar mass P3HT it is nodule‐like, while the lower Mn presented rod form. The fore polymer combined with PCMB results in lower root mean square (RMS) indicating smoother morphology, which is more appropriate for solar cells application.
Antioxidant Effects of Vitamin C on Biomedical UHMWPE Compounds
Authors: Souza Vanessa C. , Fim Fabiana C. , Lima Maria Edvania A. , Silva Lucineide B.
Published: February 2019

The aim of the present study is to evaluate the antioxidant activity of ascorbic acid (Vitamin C) at concentrations of 0.5, 1.0, and 2.0% wt on Biomedical Ultra High Molecular Weight Polyethylene (B‐UHMWPE), using a stable free radical 2,2‐diphenyl‐1‐picryl‐hydrazyl (DPPH). The compounds are prepared by compression molding at 160 °C for 6 min, and pressure of 10 MPa. Infrared spectroscopy indicated a weak interaction between the compound constituents, at 3600, 1800, and 1500 cm−1 bands attributed to Vitamin C. Atomic force microscopy (AFM) revealed that the addition of 2.0% wt. of Vitamin C promoted B‐UHMWPE crystalline particle size decreases and molecular disorder. In the presence of the vitamin, Raman spectroscopy suggested a decrease in the degree of polymer crystallinity which may be attributable to modifications in morphological aspects of the polymer. Vitamin C acted as an antioxidant agent, an important result; an increasing amount of radical is scavenged with the addition of the vitamin to the compounds. Thus, Vitamin C presents potential as an antioxidant for B‐UHMWPE compounds.
Cellulose Based Cryogels as Adsorbents for Organic Pollutants
Authors: Toledo Paulo V. O. , Martins Bianca F. , Pirich Cleverton L. , Sierakowski Maria Rita , Neto Erico Teixeira , Petri Denise F. S.
Published: February 2019

Cryogels of hydroxypropyl methylcellulose (HPMC) and bacterial cellulose nanocrystals (CNC) were prepared with 0, 5, or 15 wt% contents of CNC. Two types of CNC were used, namely, CNC‐SO4 and CNC, with ζ‐potential values of − (46 ± 1) mV and − (5 ± 1) mV, respectively. Regardless the CNC type or content, all cryogels presented similar density, capillarity constant, contact angle, swelling rate values, and morphology. However, the addition of only 5% of CNC‐SO4 to HPMC cryogels increased the compressive modulus from (120 ± 15) kPa to (150 ± 19) kPa. The cryogels were tested as adsorbents for 17α‐ethinyl estradiol (EE) and methylene blue (MB). In the dilute range, the pollutants removal efficiency of reinforced cryogels was considerably larger than that of neat cryogels. In the more concentrated range, all adsorbents presented similar efficiency. The adsorption isotherms of EE and MB onto cryogels fitted with sigmoidal and Freundlich adsorption models, indicating higher affinity for aerogels with 5% CNC‐SO4. Cryogels could be recycled 10 and 5 times, respectively, for MB and EE adsorption/desorption under flow without losing efficiency, disclosing their potential for preconcentration of pollutants, and environmental remediation.
Preparation and Characterization of Polymeric Microfibers of PLGA and PLGA/PPy Composite Fabricated by Solution Blow Spinning
Authors: Cerna Nahuis Liesel E. , Alvim Valente Cristhiane , de Freitas Oliveira Danilo , de Souza Basso Nara R. , Antonio Malmonge José
Published: February 2019

In this study, microfibers of poly(L‐lactic‐co‐glycolic acid) (PLGA) and PLGA/polypyrrole (PPy) composite (90/10 wt%) are produced by using the solution blow spinning (SBS) technique. PPy is synthesized by the oxidative polymerization method using p‐toluenesulfonic acid (p‐TSA) as the dopant and FeCl3 as the oxidant. The prepared PPy showed microfibers with globular particles morphology. Mixtures of porous and nonporous microfibers and microfibers incorporated with PPy are obtained. A wettability test shows that the PLGA and PLGA/PPy fibrous mats are hydrophobic. The electrical conductivity of the PLGA/PPy composite is of the same order as that of pure PLGA (≈10−10 S cm−1), indicating that the electrical percolation threshold is not reached for PPy loading of 10 wt%. The incorporation of PPy into PLGA microfibers improved the thermal stability of the composite and also increases the PLGA crystalline phase.
Effect of Babassu Mesocarp Incorporation on the Biodegradation of a PBAT/TPS Blend
Authors: Nunes Mário A. B. S. , Castro‐Aguirre Edgar , Auras Rafael A. , Bardi Marcelo A. G. , Carvalho Laura H.
Published: February 2019

The influence of thermoplastic starch (TPS) and babassu mesocarp incorporation on the biodegradation of poly(butylene adipate‐co‐terephthalate), PBAT, PBAT/TPS blend, and its biocomposite were investigated. PBAT/TPS blend (70:30) and its biocomposite containing 20% babassu (i.e., 17:58:25% wt/wt babassu mesocarp/PBAT/TPS system) were prepared by melt blending in a torque rheometer at 150 °C. Samples for biodegradation were obtained by hot pressing. Size exclusion chromatography showed that incorporation of TPS and babassu mesocarp to PBAT led to a reduction in PBAT molecular weight on the blends and composite. The reduction was higher on the blends than in the composite. Respirometry data showed that while addition of TPS accelerated biodegradation incorporation of babassu retarded it.
Effect of Processing Conditions on the Mechanical and Morphological Properties of Elastomeric Poly (Methyl Methacrylate)/Polycarbonate Blends
Authors: de Macedo Thatiana Cristina Pereira , da Silva Reinaldo Juciklécia , Pereira Laurenice Martins , do Rêgo José Kaio Max Alves , Ueki Marcelo Massayoshi , Damasceno Igor Zumba , Ito Edson Noriyuki
Published: February 2019

The aim of this study was to investigate the influence of the processing conditions in single and co‐rotational twin screw extruders on the mechanical and morphological properties of elastomeric poly (methyl methacrylate)/polycarbonate (PMMAe/PC) blends until the phase inversion. The characterizations were performed by measuring the melt flow index, capillary rheometry, thermogravimetric analysis, tensile tests, Izod impact, and atomic force microscopy (AFM). The thermal and rheological properties showed that PC had a higher sensitivity to processing conditions than PMMAe. The increase in PC concentration altered the mechanical properties of the PMMAe/PC blends with variations according to processing conditions. The morphology of PMMAe/PC blends up to phase inversion was visualized by AFM, and the results showed that the material processed with a single screw extruder obtained similar morphologies to that material processed in twin screw extruder.
Dynamic Mechanical Characterization of Composite Solid Propellant for Propellant Grain Structural Integrity Assessment
Authors: Murari Gustavo Henrique , Calciolari Fabio Luiz , de Almeida Luis Eduardo Nunes
Published: February 2019

The objective of this work was to characterize mechanical properties of composite solid propellant in order to conduct the structural integrity assessment of propellant grain. Data required for analyses regarding loads experienced during rocket motor transportation and flight were obtained. Based on time and temperature superposition, master curves were constructed from propellant mechanical properties determined by dynamic mechanical analysis. These curves can be used as input in finite elements analysis software, demonstrating the applicability of the proposed methodology.
Polymer Nanocomposites of Surface‐Modified Graphene. I: Thermal and Electrical Properties of Poly(Vinyl Alcohol)/Aminoacid‐Functionalized Graphene
Authors: Lima Thaíses B. S. , Silva Valdilene O. , Araujo Elmo S. , Araujo Patricia L. B.
Published: February 2019

Extrinsic electrically conducting polymer composites are versatile materials for applications in sensors, electrical components, antistatic coatings, among others. The use of carbon‐based conducting loads, such as graphene, in polymer nanocomposites allows the manufacturing of suitable electrically conducting films for a variety of applications. In our work, graphene sheets are covalently modified with histidine, phenylalanine, or beta‐alanine aminoacids, in order to improve dispersion and impart extrinsic conductivity to poly(vinyl alcohol) (PVA) films. The presence of organic groups in the surface of graphene sheets improved their dispersion in polymer matrices. In addition, such benign surface modifiers are suitable to produce environmentally friendly, electrically conducting loads for polymer nanocomposites. Our findings showed that aminoacid‐functionalized graphenes have good dispersability, resulting in semiconducting nanocomposite films with preserved thermal stability, suggesting that these carbon‐based nanoloads are suitable additives for PVA in applications including antistatic paints and coatings.
The Role of Dispersion Technique and Type of Clay on the Mechanical Properties of Clay/Epoxy Composites
Authors: Amaral Ceretti Daniel Victor , Escobar da Silva Laura Caetano , do Carmo Gonçalves Maria , Carastan Danilo Justino
Published: February 2019

Epoxy composites containing montmorillonite (MMT), laponite (LAP), and halloysite nanotubes (HNT) are prepared using two different dispersion techniques: sonication and high energy ball milling. The mechanical properties of the composite materials are monitored as a function of the type of clay particle/geometry and processing technique. The materials are characterized by X‐ray diffraction, microscopy techniques, parallel plate rheometry, and mechanical testing. Experimental results present clear evidence that sonication has led to better nanoparticle dispersion. The results also indicate that the composites manufactured via sonication exhibited higher ductility.
Synthesis and Evaluation of Multifunctional Anionic Initiators Based on n‐BuLi and Meta‐Diisopropenyl Benzene
Authors: Cazumbá Anderson , Tauchert Elias , Nicolini Luis F. , Moutinho Marcus , Pinto José Carlos
Published: February 2019

Multifunctional anionic initiators based on n‐BuLi and the diolefin m‐DIB (meta‐diisopropenylbenzene) were synthesized and stored at different temperatures, using different polar modifier contents and solvents. Solution styrene polymerizations were then used to evaluate the performances of the produced initiators. Based on the obtained results, it is shown that the best initiators were the ones prepared at 40 °C, using the DTHFP/BuLi molar feed ratio of 0.1 in cyclohexane. At these preparation conditions, the produced initiator has higher contents of multifunctional species and presents higher stability. The DTHFP/n‐BuLi ratio of 0.1 was shown to be the most appropriate because it minimizes the formation of oligomers and allows for suitable initiation of styrene polymerizations.
Synthesis and Characterization of Binders for Propellants
Authors: de Araújo Nicolis Amaral , Pinto José Carlos , Caldeira Aldélio Bueno , dos Santos Cople Lima Keila , dos Santos Lima Antonio Luís
Published: February 2019

The present work is devoted to the synthesis and characterization of polymeric binders for use in composite propellants. Polymeric binders hold together solid fuel and oxidant particles that constitute composite propellants, forming a solid elastic mass that is able to withstand thermal and mechanical stresses. Usually, the binder is also a fuel, working as a source of carbon and hydrogen for the propellant burning reaction. In the present study, polyester binders based on the reaction of green 1,2‐propanediol, 1,3‐propanediol, ethylene glycol, diethylene glycol, and 1,4‐butanediol with succinic acid were produced through two‐step polycondensations (esterification and transesterification), using the initial proportion of 4 (OH): 3 (COOH). Polymer samples were characterized with help of Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Matrix‐Assisted Laser Desorption Ionization Process (MALDI TOF) and Reaction Calorimetry (RC). The obtained results indicate that the use of the proposed polymeric binders can be advantageous for formulation of new green composite propellants.
Wear and corrosion studies of graphite‐aluminum composite reinforced with micro/nano‐TiB2 via spark plasma sintering
Authors: Durowoju M.O. , Sadiku E.R. , Diouf S. , Shongwe M.B. , Makena I.M. , Ramakokovhu M.M. , Olubambi P.A. , Eze A.A.
Published: February 2019

The demand for lightweight materials in the automobile and aerospace industries has led to various researches on graphite and graphite‐aluminum composites. The aim of this study was to investigate the effect of the addition of micron/nano TiB2 particles on the properties of graphite‐aluminum composite particularly the wear resistance. The powders were sintered at 550 °C and 50 MPa with more attention on the effect of the sintering temperature on densification, microhardness, coefficient of thermal expansion, wear and frictional force. The results show that the addition of nano TiB2 reduces the densification while improving the hardness of Gr−Al composite with the lowest value being 96.0 % of relative density and the highest microhardness of 43.58 HV 0.1. The coefficient of thermal expansion and frictional force of the composite materials increases with increasing TiB2 content and heating rate (100 °C/min–150 °C/min). TiB2 particles enhance the wear resistance of graphite‐aluminum composite. The addition of micro/nanoparticles of TiB2 to graphite‐aluminum composite increases its corrosion rate with improved passivation behavior in 3.5 wt.% NaCl solution. Nevertheless, 5 wt.% nano (100 °C/min) TiB2 additions do not affect the overall corrosion rate. This work has shown that we can take advantage of some of the properties of TiB2 to improve the performance of graphite‐aluminum composite.
Influence of equal channel angular pressing in an acute angle die with a back pressure notch on grain refinement, torsion and mechanical properties of aluminium
Authors: Sadasivan N. , Balasubramanian M. , Venkatesh R. , Vigneshram S. , Sunil T.
Published: February 2019

Severe plastic deformation improves the strength of a metal by strain hardening. Of the various severe plastic deformation processes, equal channel angular pressing proves to be the right candidate for bulk metal processing. Extensive works were carried out on equal channel angular pressing with channel angle ranging from 90° to 120° with or without back pressure on the exit channel. Numerical analyses suggest that reducing the channel angle below 90° would enhance the magnitude of strain imparted and, with prediction of a lesser strain homogeneity in such cases. Hence an acute angled equal channel angular pressing die with a back‐pressure notch sunken into the roof of the exit channel was designed, fabricated and was used for processing pure aluminium. Various mechanical properties of the processed materials were tested and acute angle processing imparted superior tensile strength to the work pieces in a single pass that would require several passes in a conventional equal channel angular pressing die. Substantial improvement in grain refinement and torsional properties was identified.
Optimization of austenitization time for press hardening of steels by using Hollomon‐Jaffe parameter
Authors: Fritz S. , Pfeiffer M.A. , Gollnick J.
Published: February 2019

Das Presshärten ermöglicht als Kombinationsprozess aus Wärmebehandlung und Formgebung die Herstellung von hochfesten Karosseriestrukturbauteilen aus Stahl im Serienmaßstab. Der konventionelle Austenitisierungsprozess im Ofen bestimmt dabei maßgeblich die Prozessgesamtdauer. In dieser Arbeit wird ein alternativer Ansatz zur herkömmlichen, auf Zeit‐Temperatur‐Austenitisierungsschaubildern oder Erfahrungswerten beruhenden, Ermittlung der nötigen Austenitisierungszeit untersucht. Die Berechnung der optimalen Austenitisierungszeit basiert dabei auf experimentell gewonnenen Werkstoffkennwerten. Die Grundlage zur phänomenologischen Beschreibung des Austenitisierungsvorgangs bildet der durch den Hollomon‐Jaffe Parameter beschriebene Zusammenhang zwischen Temperatur und Zeit für den Reaktionsfortschritt thermisch aktivierter Prozesse. Die nötigen Werkstoffkennwerte werden mittels Austenitisierungsversuchen in einem Dilatometer anhand von Kleinproben bestimmt. Die Anwendbarkeit dieses Parameters zur Berechnung der optimalen Austenitisierungsdauer für isotherme und prozessnahe Temperaturführung wird für die Stähle 22MnB5 und X15Cr13 exemplarisch beschrieben und nachgewiesen.
High surface area ZnAl2O4/reduced graphene oxide nanocomposites with enhanced photocatalytic performance
Authors: Miroliaee A. , Hoshdari S. , Mohammadi Chahaki M. , Abdouss M.
Published: February 2019

In this study, the fabrication of ZnAl2O4/reduced graphene oxide nanocomposites is reported for the initial time. Two nanocomposites, ZnAl2O4/reduced graphene oxide‐50 and ZnAl2O4/reduced graphene oxide‐100, with different reduced graphene oxide contents (50 mg/ml and 100 mg/ml initial graphene oxide concentration respectively) were synthesized via a hydrothermal route; and characterized with the aid of suitable characterization and analytical techniques. For comparative purposes, two pure ZnAl2O4 samples were fabricated by citrate sol‐gel and urea combustion methods. The photocatalytic activity of the synthesized pure nanospinels and nanocomposites was studied for the degradation of rhodamine B dye under ultraviolet–A light irradiation. Compared to pure ZnAl2O4 nanoparticles, ZnAl2O4/reduced graphene oxide nanocomposites exhibited superior photocatalytic activity. The highest efficiency was observed for ZnAl2O4/reduced graphene oxide‐100 composite, where; full degradation of rhodamine B occurred after 45 min. The enhancements of the photocatalytic performance of ZnAl2O4/reduced graphene oxide composites were mainly attributed to unique electronic and surface properties of reduced graphene oxide.
Magnetic immobilization of a quorum sensing signal hydrolase, AiiA
Authors: Wang Lin , Xu Haixing , Liu Zewen , Sun Taolei , Yuan Chengqing , Yang Ying , Guo Junhui , Xie Hao
Published: February 2019

Magnetic immobilization of quorum sensing (QS) signal hydrolases provides a convenient solution for quenching QS process that is essential for bacterial biofilm formation and antimicrobial resistance. In the present study, a QS signal hydrolase, AiiA, was fused with a magnetic protein, MagR, and expressed in Escherichia coli. Magnetic immobilization of AiiA was achieved on Fe3O4‐SiO2 iron beads and was confirmed via SDS‐PAGE, zeta potential measurement, FTIR spectrometry, and SEM analysis. The magnetic immobilized AiiA exhibited activity in degrading the quorum sensing signal, C6‐HSL. This study opens a new avenue to actively immobilize enzymes via magnetic interaction and quench quorum sensing.
Impact of seasonality, storage of semen, and sperm head‐shape on whole tissue methylation and expression of methylation responsive candidate genes in swine placenta and fetal livers from summer and winter breedings
Authors: Rempel Lea A. , Krautkramer Megan M. , Parrish John J. , Miles Jeremy R.
Published: February 2019

Epigenetics includes the study of external factors that can influence the expression of genes by altering the accessibility of DNA through methylation. To investigate the epigenetic influence of season, sperm head shape, and semen storage on placental and fetal tissues, pregnancies were generated in the summer or winter using boar semen from either least or most sperm head shape change, collected during cool or warm seasons, and stored as cooled‐extended or cryopreserved. The lowest (p < 0.05) ratios of 5‐methylcytosine to 5‐hydroxymethylcytosine activity (5mC:5hmC) in fetal liver were from summer breedings and in placental tissues from winter breedings. The relative expression of placental
CDH1 tended (
p < 0.10) to be greater in placenta generated from cryopreserved semen or semen collected during cool periods. The relative expression of placental
GNAS was affected (
p < 0.05) by the interaction of breeding and semen collection seasons. Cryopreserved semen increased (
p < 0.05) the placental relative expression of
GNAS. Placental
MEST and
RHOBTB3 tended (
p < 0.10) to have a greater relative expression from pregnancies generated using semen collected during cool periods used during winter breedings. Within fetal liver, the relative expression of
GNAS and
HGF was greater (
p < 0.05) from winter breedings. Interaction of winter breedings and least sperm head shape change tended (
p < 0.10) to have the greatest fetal liver expression of
CDH1. Seasonality of semen collection, breeding, and the effect on sperm head shape change had an influence on the expression of genes with known differentially methylated regions or response to methylation activity from embryonic and extraembryonic tissues.
On the rheological characterisation of liquefied sands through the dam‐breaking test
Authors: Della Vecchia Gabriele , Cremonesi Massimiliano , Pisanò Federico
Published: February 2019

This paper concerns the rheological characterisation of liquefied sands as non‐Newtonian Bingham fluids. For this purpose, dam‐breaking laboratory tests are often executed and interpreted, offering a viable option to identify the properties of fluidised water‐soil mixtures. However, limited attention has been devoted so far to clarify what variables and measurements would allow unambiguous calibration of Bingham parameters, namely, the viscosity η and the yield stress τy. The numerical results of parametric studies based on the particle finite element method (PFEM) are critically inspected to gain deeper insight into the problem. First, it is confirmed that multiple η − τy pairs may reproduce the same experimental evidence when formed by only one measurement—usually, the post–dam‐breaking displacement of the bottom toe (tip) of the liquefied mass. Then, two alternative procedures are proposed for unambiguous identification of both η and τy: one is based on monitoring the evolving aspect ratio of the fluid mass during free, gravity‐driven flow; the other relies on a slightly different dam‐breaking test, also including impact against a rigid obstacle. In particular, the latter approach reduces the relevant duration of the test, reducing the possible influence of reconsolidation effects on the calibration of rheological parameters.
Patient participation in the clinical pathway—Nurses’ perceptions of adults’ involvement in haemodialysis
Authors: Andersen‐Hollekim Tone E. , Kvangarsnes Marit , Landstad Bodil J. , Talseth‐Palmer Bente A. , Hole Torstein
Published: February 2019

Aim

To develop knowledge of nurses’ perceptions of participation for patients treated with haemodialysis and their next of kin.

Design

A qualitative study with a hermeneutic approach.

Methods

The data were collected in 2015 through focus groups with 13 nurses in Central Norway.

Results

The nurses reported that patient participation ranging from non‐involvement to shared decision‐making was related to whether dialysis was initiated as acute or scheduled. The restrictions required in chronic haemodialysis limited participation. The next of kin were not involved. The nurses highlighted interventions on both the individual and system levels to strengthen participation.

Conclusion

Dialysis units should develop strategies for participation related to individual needs and design treatment in cooperation with patients and their families, ensuring involvement early in the clinical pathway. Further research is needed on issues related to next of kin, including their desired level of involvement.
Attenuation of Postmeal Metabolic Indices with Red Raspberries in Individuals at Risk for Diabetes: A Randomized Controlled Trial
Authors: Xiao Di , Zhu Lanjun , Edirisinghe Indika , Fareed Jawed , Brailovsky Yevgeniy , Burton‐Freeman Britt
Published: February 2019

Objective

This study investigated the effect of red raspberry intake on meal‐induced postprandial metabolic responses in individuals who have overweight or obesity with prediabetes and insulin resistance (PreDM‐IR), and in metabolically healthy individuals (Reference).

Methods

Thirty‐two adults (PreDM‐IR, n = 21; Reference, n = 11) were randomized to a controlled, three‐arm, single‐blinded, crossover trial. Participants were provided 0 g of frozen red raspberries (Control), 125 g of frozen red raspberries (RR‐125) (~1 cup), or 250 g of frozen red raspberries (RR‐250) (~2 cups), with a challenge breakfast meal (high carbohydrate/moderate fat) on three separate days. Multiple blood samples were collected up to 8 hours post breakfast with a final blood sample at 24 hours. A snack was provided at 6 hours.

Results

Breakfast containing RR‐125 and RR‐250 significantly reduced 2‐hour insulin area under the curve, and RR‐250 reduced peak insulin, peak glucose, and 2‐hour glucose AUC compared with Control in the PreDM‐IR group (P < 0.05). Postprandial triglycerides were significantly lower after RR‐125 versus RR‐250 (P = 0.01) but not different from Control (P > 0.05). No significant meal‐related differences were observed for oxidative stress or inflammatory biomarkers.

Conclusions

Our findings suggest that red raspberries aid in postmeal glycemic control in individuals with PreDM‐IR, reducing glycemic burden with less insulin, which may be related to improved tissue insulin sensitivity.
Monitoring Hydrogenation Reactions using Benchtop 2D NMR with Extraordinary Sensitivity and Spectral Resolution
Authors: Gołowicz Dariusz , Kazimierczuk Krzysztof , Urbańczyk Mateusz , Ratajczyk Tomasz
Published: February 2019

Low‐field benchtop nuclear magnetic resonance (BT‐NMR) spectrometers with Halbach magnets are being increasingly used in science and industry as cost‐efficient tools for the monitoring of chemical reactions, including hydrogenation. However, their use of low‐field magnets limits both resolution and sensitivity. In this paper, we show that it is possible to alleviate these two problems through the combination of parahydrogen‐induced polarization (PHIP) and fast correlation spectroscopy with time‐resolved non‐uniform sampling (TR‐NUS). PHIP can enhance NMR signals so that substrates are easily detectable on BT‐NMR spectrometers. The interleaved acquisition of one‐ and two‐dimensional spectra with TR‐NUS provides unique insight into the consecutive moments of hydrogenation reactions, with a spectral resolution unachievable in a standard approach. We illustrate the potential of the technique with two examples: the hydrogenation of ethylphenyl propiolate and the hydrogenation of a mixture of two substrates – ethylphenyl propiolate and ethyl 2‐butynoate.
Bimolecular Cross‐Metathesis of a Tetrasubstituted Alkene with Allylic Sulfones
Authors: Sapkota Rishi R. , Jarvis Jacqueline M. , Schaub Tanner M. , Talipov Marat R. , Arterburn Jeffrey B.
Published: February 2019

Exquisite control of catalytic metathesis reactivity is possible through ligand‐based variation of ruthenium carbene complexes. Sterically hindered alkenes, however, remain a generally recalcitrant class of substrates for intermolecular cross‐metathesis. Allylic chalcogenides (sulfides and selenides) have emerged as “privileged” substrates that exhibit enhanced turnover rates with the commercially available second‐generation ruthenium catalyst. Increased turnover rates are advantageous when competing catalyst degradation is limiting, although specific mechanisms have not been defined. Herein, we describe facile cross‐metathesis of allylic sulfone reagents with sterically hindered isoprenoid alkene substrates. Furthermore, we demonstrate the first example of intermolecular cross‐metathesis of ruthenium carbenes with a tetrasubstituted alkene. Computational analysis by combined coupled cluster/DFT calculations exposes a favorable energetic profile for metallacyclobutane formation from chelating ruthenium β‐chalcogenide carbene intermediates. These results establish allylic sulfones as privileged reagents for a substrate‐based strategy of cross‐metathesis derivatization.
Facile Protection of Lithium Metal for All‐Solid‐State Batteries
Authors: Delaporte Nicolas , Guerfi Abdelbast , Demers Hendrix , Lorrmann Henning , Paolella Andrea , Zaghib Karim
Published: February 2019

A nanolayer of reactive propyl acrylate silane groups was deposited on a lithium surface by using a simple dipping method. The polymerization of cross‐linkable silane groups with a layer of ally‐ether‐ramified polyethylene oxide was induced by UV light. SEM analysis revealed a good dispersion of silane groups grafted on the lithium surface and a layer of polymer of about 4 μm was obtained after casting and reticulation. The electrochemical performance for the unmodified and modified lithium electrodes were compared in symmetrical Li/LLZO/Li cells. Stable plating/stripping and low interfacial resistance were obtained when the modified lithium was utilized, indicating that the combination of silane and polymer deposition is promising to increase Li‐metal/garnet contact.
Effect of micro‐/nano‐hybrid hydroxyapatite rod reinforcement in composite resins on strength through thermal cycling
Authors: Wu Yu‐Ren , Chang Chin‐Wei , Chang Kai‐Chi , Lin Dan‐Jae , Ko Chia‐Ling , Wu Hui‐Yu , Chen Wen‐Cheng
Published: February 2019

This study was based on the hypothesis that mechanical strength and ion release from bioactive restorative composites containing hydroxyapatite (HA) nanometer scale fillers lead to superior precipitation ability, which could facilitate load transfer, bridge, and toughening mechanisms. The prepared specimens included the respective composite resins with singular filler form of synthetic 50 wt% microrod HA (abbreviated as 50Mr‐HA) and nanorod HA (designated as 50Nr‐HA) and micro‐/nanorod hybrid fillers with 50 wt% microrod HA mixing with 5 and 10 wt% nanorod HA (55 and 60 wt% fillers in composites), which were designated as 50M5Nr‐HA and 50M10Nr‐HA groups, respectively. The measured properties were as follows: flexural strength and re‐precipitation after specimen immersion for 24 h and further exposure to thermal fatigue between 5°C and 55°C for 600 and 2,400 cycles. The groups of micro‐/nanorod hybrid resins reinforced with nanorods showed a significant increase in microhardness, modulus, and the capacity to re‐precipitate. The 50M5Nr‐HA sample showed the highest flexural strength after thermal fatigue among the four types of fillers. The 50Nr‐HA sample showed the lowest flexural bending strength and modulus. The 50Mr‐HA filler showed better re‐mineralization capability after immersion. However, the micro‐/nanorod hybrid 50M5Nr‐HA exhibited an advantage after thermal fatigue and could avoid the aggregate problem that occurred in 50Nr‐HA or 50M10Nr‐HA. With proper hybrid nanorods and microrod HA‐reinforced composites exhibited superior potential application as for dental caries restoration. POLYM. COMPOS., 40:3703–3710, 2019. © 2019 Society of Plastics Engineers
Paediatric safety signals identified in VigiBase: Methods and results from Uppsala Monitoring Centre
Authors: Star Kristina , Sandberg Lovisa , Bergvall Tomas , Choonara Imti , Caduff‐Janosa Pia , Edwards I. Ralph
Published: February 2019

Purpose

The purpose of this study is to uncover previously unrecognised risks of medicines in paediatric pharmacovigilance reports and thereby advance a safer use of medicines in paediatrics.

Methods

Individual case safety reports (ICSRs) with ages less than 18 years were retrieved from VigiBase, the World Health Organization (WHO) global database of ICSRs, in September 2014. The reports were grouped according to the following age spans: 0 to 27 days; 28 days to 23 months; 2 to 11 years; and 12 to 17 years. vigiRank, a data‐driven predictive model for emerging safety signals, was used to prioritise the list of drug events by age groups. The list was manually assessed, and potential signals were identified to undergo in‐depth assessment to determine whether a signal should be communicated.

Results

A total of 472 drug‐event pairs by paediatric age groups were the subject of an initial manual assessment. Twenty‐seven drug events from the two older age groups were classified as potential signals. An in‐depth assessment resulted in eight signals, of which one concerned harm in connection with off‐label use of dextromethorphan and another with accidental overdose of olanzapine by young children, and the remaining signals referred to potentially new causal associations for atomoxetine (two signals), temozolamide, deferasirox, levetiracetam, and desloratadine that could be relevant also for adults.

Conclusions

Clinically relevant signals were uncovered in VigiBase by using vigiRank applied to paediatric age groups. Further refinement of the methodology is needed to identify signals in reports with ages under 2 years and to capture signals specific to the paediatric population as a risk group.
Determination of pKa values of fluorocompounds in water using 19F NMR
Authors: Parman Elisabeth , Toom Lauri , Selberg Sigrid , Leito Ivo
Published: February 2019

Brønsted acidities of 19 fluorocompounds in the pKa range from 3.5 to 10 have been measured in aqueous solution using an approach involving absolute and relative pKa measurements with 19F NMR. 19F NMR has not been frequently used for determining pKa values, but it has a number of advantages, especially when relative values are considered: accurate concentrations not needed, tolerant to impurities, several compounds can be measured simultaneously, several uncertainty sources cancel out.
Implementing Reverse Phase Protein Array Profiling as a Sensitive Method for the Early Pre‐Clinical Detection of Off‐Target Toxicities Associated with Sunitinib Malate
Authors: O'Farrell Alice C. , Miller Ian S. , Evans Rhys , Alamanou Marina , Cary Maurice , Mallya Udupi Girish , Lafferty Adam , Monsefi Naser , Cremona Mattia , Prehn Jochen H. M. , Verheul Henk M. , Gallagher William M. , Gehrmann Mathias , Byrne Annette T.
Published: February 2019

Purpose

The tyrosine kinase inhibitor (TKI) sunitinib is a multi‐targeted agent approved across multiple cancer indications. Nevertheless, since approval, data has emerged to describe a worrisome side effect profile including hypertension, hand‐foot syndrome, fatigue, diarrhea, mucositis, proteinuria, and (rarely) congestive heart failure. It has been hypothesized that the observed multi‐parameter toxicity profile is related to “on‐target” kinase inhibition in “off‐target” tissues.

Experimental Design

To interrogate off‐target effects in pre‐clinical studies, a reverse phase protein array (RPPA) approach is employed. Mice are treated with sunitinib (40 mg kg−1) for 4 weeks, following which critical organs are removed. The Zeptosens RPPA platform is employed for protein expression analysis.

Results

Differentially expressed proteins associated with damage and/or stress are found in the majority of organs from treated animals. Proteins differentially expressed in the heart are associated with myocardial hypertrophy, ischaemia/reperfusion, and hypoxia. However, hypertrophy is not evidenced on histology. Mild proteinuria is observed; however, no changes in renal glomerular structure are visible via electron microscopy. In skin, proteins associated with cutaneous inflammation, keratinocyte hyper‐proliferation, and increased inflammatory response are differentially expressed.

Conclusions and Clinical Relevance

It is posited that pre‐clinical implementation of a combined histopathological/RPPA approach provides a sensitive method to mechanistically elucidate the early manifestation of TKI on‐target/organ off‐target toxicities.
Photoluminescence Enhancement and Change in the Second Nearest Neighbor Distance of Sm‐Doped TiO2 Thin Films
Authors: Murayama Mariko , Yoda Kensaku , Shiraishi Keita , Crowe Iain F. , Komuro Shuji , Zhao Xinwei
Published: February 2019

Rare earth ions in the oxide semiconductors are commonly surrounded by oxygen (O) ligands which are the first nearest neighbors to rare earths. Intensities of the rare earth‐related luminescence are strongly influenced by crystal symmetry of the rare earth ions. Especially, distortion of the first nearest neighbor bonds is key to improving emission from these luminescent centers. In this paper, samarium (Sm) is doped into titanium dioxide (TiO2) with two different crystal structures, anatase and rutile, to investigate the influence of the different host crystal symmetries on the material optical properties. Sm‐related photoluminescence (PL) intensity from the samples, annealed at different temperatures reveals the optimal preparation condition. Also, X‐ray absorption fine structure (XAFS) spectra are measured, providing detailed information regarding the local fine structure around Sm. From these studies, the authors find that the optical properties of the TiO2:Sm are not only influenced by structural changes in the first nearest neighbor, O, but also the second nearest neighbor, Ti by annealing at different temperatures and/or crystal structure of TiO2. The authors discuss the connection between the enhanced PL intensity and the local fine structure around the Sm luminescent centers, including these changes in the second nearest neighbor, Ti.