bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical characterisation of Nigerian red propolis and its biological activity against Trypanosoma Brucei
Authors: Omar Ruwida M. K. , Igoli John , Gray Alexander I. , Ebiloma Godwin Unekwuojo , Clements Carol , Fearnley James , Edrada Ebel Ru Angeli , Zhang Tong , De Koning Harry P. , Watson David G. 
Published: December 2015

AbstractIntroductionA previous study showed the unique character of Nigerian red propolis from Rivers State, Nigeria (RSN), with regards to chemical composition and activity against Trypanosoma brucei in comparison with other African propolis.ObjectiveTo carry out fractionation and biological testing of Nigerian propolis in order to isolate compounds with anti‐trypanosomal activity. To compare the composition of the RSN propolis with the composition of Brazilian red propolis.MethodologyProfiling was carried out using HPLC‐UV‐ELSD and HPLC‐Orbitrap‐FTMS on extracts of two samples collected from RSN with data extraction using MZmine software. Isolation was carried out by normal phase and reversed phase MPLC. Elucidation of the compounds with a purity > 95% was performed by 1D/2D NMR HRMS and HRLC‐MSn.ResultsTen phenolic compounds were isolated or in the case of liquiritigenin partially purified. Data for nine of these correlated with literature reports of known compounds i.e. one isoflavanone, calycosin (1); two flavanones, liquiritigenin (2) and pinocembrin (5); an isoflavan, vestitol (3); a pterocarpan, medicarpin (4); two prenylflavanones, 8‐prenylnaringenin (7) and 6‐prenylnaringenin (8); and two geranyl flavonoids, propolin D (9) and macarangin (10). The tenth was elucidated as a previously undescribed dihydrobenzofuran (6). The isolated compounds were tested against Trypanosoma brucei and displayed moderate to high activity. Some of the compounds tested had similar activity against wild type T. brucei and two strains displaying pentamidine resistance.ConclusionNigerian propolis from RSN has some similarities with Brazilian red propolis. The propolis displayed anti‐trypanosomal activity at a potentially useful level. Copyright © 2015 John Wiley & Sons, Ltd.
Role of family caregivers' self‐perceived preparedness for the death of the cancer patient in long‐term adjustment to bereavement
Authors: Kim Youngmee , Carver Charles S. , Spiegel David , Mitchell Hannah‐Rose , Cannady Rachel S. 
Published: December 2015

AbstractBackgroundA substantial number of family caregivers go through bereavement because of cancer, but little is known about the bereaved caregivers' long‐term adjustment. This study aimed to document levels of bereavement outcomes (prolonged grief symptoms, intense emotional reaction to the loss, depressive symptoms, and life satisfaction) among family cancer caregivers 3–5 years post‐loss and to investigate how self‐rated preparedness for the patient's death predicted those bereavement outcomes.MethodsFamily members participated in a nationwide survey for cancer caregivers 2 years after the relative's diagnosis (T1). Of those, 109 were identified as bereaved by 5 years post‐diagnosis (T2). Of those, 88 continued to participate at 8‐year follow‐up (T3) and provided valid data for the study variables. Caregivers' distress risk factors were measured at T1, satisfaction with palliative care and preparedness for the death of the patient at T2, and time since death of the patient at T2 or T3.ResultsSubstantial numbers of family members (18% to 48%) displayed heightened levels of bereavement‐related psychological distress years after the loss. Hierarchical general linear modeling revealed that perceived preparedness for the death of the patient concurrently and prospectively predicted better adjustment to bereavement, independent of contributions of other factors studied.ConclusionsFindings underscore the high prevalence of long‐lasting bereavement‐related distress among family cancer caregivers and the role of preparedness for the relative's death in the level of that distress. Findings suggest that psychosocial programs among caregivers focus on not only caregiving skills per se but also preparedness for the death of the patient. Copyright © 2015 John Wiley & Sons, Ltd.
Social Trust Between Rural Migrants and Urban Locals in China – Exploring the Effects of Residential Diversity and Neighbourhood Deprivation
Authors: Wang Zheng , Zhang Fangzhu , Wu Fulong 
Published: December 2015

AbstractThe social integration of migrants has become a major challenge for Chinese cities as many rural migrants still face discrimination from urban natives. Research suggests that intergroup social trust can improve cohesion and reduce stigmatisation. However, little is known about the trust level between migrants and locals and its underlying dynamics in urban China. Our study explores the trust between native Shanghai residents and rural migrants and how neighbourhood factors including residential diversity and neighbourhood poverty may play a role. We adopt a multilevel model to analyse the 1,420 questionnaire samples collected in 2013 from local and migrant residents in Shanghai. Our results show that people living in areas with more migrant residents also have higher intergroup social trust, which may indicate that exposure to more out‐group neighbours can remove preconceived stigmas and foster tolerance. In contrast, there is less intergroup trust in poor neighbourhoods although migrant residents are exceptions. We speculate that migrants are less affected by local poverty because they are less spatially bound to the locality and are thus less likely to compete with native residents over local resources. Our results differ from findings in multi‐ethnic societies where residential diversity causes distrust, but we believe this is a reasonable outcome considering that locals and migrants in urban China share more in common such as ethnicity, language, and national identity. © 2015 The Authors.Population, Space and Placepublished by John Wiley & Sons Ltd.
Fragmentation study of aminoalcohol‐diterpenoid alkaloids by electrospray ionization time‐of‐flight mass spectrometry
Authors: Liu Xiuxiu , Tang Minghai , Wang Lu , Chao Ruobing 
Published: December 2015

RationaleAminoalcohol‐diterpenoid alkaloids were found to be a group of cardioactive substances in the lateral roots of Aconitum carmichaeli Debx. Studies on the fragmentation behaviors and features of these alkaloids in mass spectrometry would be important for their structural identification and in vivo metabolic research, which has not received much attention thus far.MethodsIn this study, the fragmentation behaviors of 14 aminoalcohol‐diterpenoid alkaloids were investigated by utilizing high‐resolution time‐of‐flight tandem mass spectrometry. By analysis of the obtained MS2 data, we summarized the fragmentation features of the corresponding alkaloids under different collision energy.ResultsThe dissociation of functional groups from the skeleton was observed as the main fragmentation way in electrospray ionization (ESI) mode. The order of fragmentation sites was C1/C3 > C16 > C15 > C6 > N, with loss of one or more CH3OH, H2O, C2H4 (substituent on N atom) or CO (at C15) groups.ConclusionsThe first systematic investigations on the fragmentation of aminoalcohol‐diterpenoid alkaloids are described in this paper, setting the stage for an in‐depth identification and study of the corresponding components in complex systems. Copyright © 2015 John Wiley & Sons, Ltd.
Diet‐tissue stable isotope (Δ13C and Δ15N) discrimination factors for multiple tissues from terrestrial reptiles
Authors: Steinitz Ronnie , Lemm Jeffrey M. , Pasachnik Stesha A. , Kurle Carolyn M. 
Published: December 2015

RationaleStable isotope analysis is a powerful tool for reconstructing trophic interactions to better understand drivers of community ecology. Taxon‐specific stable isotope discrimination factors contribute to the best use of this tool. We determined the first Δ13C and Δ15N values for Rock Iguanas (Cyclura spp.) to better understand isotopic fractionation and estimate wild reptile foraging ecology.MethodsThe Δ13C and Δ15N values between diet and skin, blood, and scat were determined from juvenile and adult iguanas held for 1 year on a known diet. We measured relationships between iguana discrimination factors and size/age and quantified effects of lipid extraction and acid treatment on stable isotope values from iguana tissues. Isotopic and elemental compositions were determined by Dumas combustion using an elemental analyzer coupled to an isotope ratio mass spectrometer using standards of known composition.ResultsThe Δ13C and Δ15N values ranged from –2.5 to +6.5‰ and +2.2 to +7.5‰, respectively, with some differences among tissues and between juveniles and adults. The Δ13C values from blood and skin differed among species, but not the Δ15N values. The Δ13C values from blood and skin and Δ15N values from blood were positively correlated with size/age. The Δ13C values from scat were negatively correlated with size (not age). Treatment with HCl (scat) and lipid extraction (skin) did not affect the isotope values.ConclusionsThese results should aid in the understanding of processes driving stable carbon and nitrogen isotope discrimination factors in reptiles. We provide estimates of Δ13C and Δ15N values and linear relationships between iguana size/age and discrimination factors for the best interpretation of wild reptile foraging ecology. Copyright © 2015 John Wiley & Sons, Ltd.
Electrospray ion mobility mass spectrometry of positively and negatively charged (1R,2S)‐dodecyl(2‐hydroxy‐1‐methyl‐2‐phenylethyl)dimethylammonium bromide aggregates
Authors: Indelicato Serena , Bongiorno David , Ceraulo Leopoldo , Calabrese Valentina , Piazzese Daniela , Napoli Anna , Mazzotti Fabio , Avellone Giuseppe , Di Stefano Vita , Turco Liveri Vincenzo 
Published: December 2015

RationaleSelf‐assembling processes of surfactants in the gas phase constitute a developing research field of interest since they allow information to be gained on the peculiar structural organization of these aggregates, on their ability to incorporate from small molecules up to proteins and on their possible use as carriers of drugs in the gas phase or as cleaning agents and exotic reaction media.MethodsThe mass spectra of charged aggregates of the chiral surfactant (1R,2S)‐dodecyl(2‐hydroxy‐1‐methyl‐2‐phenylethyl)dimethylammonium bromide (DMEB) in the gas phase have been recorded using a Synapt G2‐Si mass spectrometer in the positive and negative ion mode. For comparison purposes, the mass spectra of sodium bis(2‐ethylhexyl)sulfosuccinate and sodium octane sulfonate aggregates have also been recorded under the same experimental conditions. The collisional cross sections of positively and negatively charged DMEB aggregates were obtained through an appropriate calibration of the measured drift times.ResultsFor all the surfactants investigated, it has been found that there is a lowest and a highest limit of the aggregation number at each charge state: no aggregates are found outside this range. Moreover, the occurrence at each aggregation number and extra charge of a unique value of drift time points toward aggregates whose conformations do not show discernible shape change in the experiment time scale. The analysis of the collisional cross sections emphasizes that the DMEB aggregates are nearly spherical clusters somewhat affected by the charge state and constituted by interlaced polar and apolar domains.ConclusionsThe analysis of all the experimental findings indicates that in the gas phase DMEB forms supramolecular aggregates characterized by an internal organization whose stability is triggered by the charge state. The comparison of the behavior of DMEB aggregates with that of sodium bis(2‐ethylhexyl)sulfosuccinate and sodium octane sulfonate aggregates allows us to highlight the effects on the aggregate organization in gas phase due to nature of the head group and alkyl chain steric hindrance. Copyright © 2015 John Wiley & Sons, Ltd.
Reagent approaches for improved detection of chlorate and perchlorate salts via thermal desorption and ionization
Authors: Kelley Jude A. , Ostrinskaya Alla , Geurtsen Geoff , Kunz Roderick R. 
Published: December 2015

RationaleTechniques for improving the detectability of chlorate and perchlorate salts with thermal desorption based ionizers (i.e. radioactive, corona discharge and photoionization‐based) are desired. This work employs acidic reagents to chemically transform chlorate and perchlorate anions into traces of chloric and perchloric acid. These high vapor pressure acids are easier to detect than the originating salts.MethodsThe efficacy of the reagent chemistry was quantified with a triple‐quadrupole mass spectrometer interfaced with a custom‐built thermal‐desorption atmospheric‐pressure chemical ionization (TD‐APCI) source. Additional experiments were conducted using tandem IMS/MS instrumentation. Reagent pKa and pH values were varied in order to gain a better understanding of how those parameters affect the degree of observed signal enhancement.ResultsSamples of chlorates and perchlorates treated with liquid acidic reagents exhibit signal enhancement of up to six orders of magnitude compared with signals from untreated analytes. Three orders of magnitude of signal enhancement are demonstrated using solid‐state reagents, such as weakly acidic salts and polymeric acids. Data is presented that demonstrates the compatibility of the solid‐state approach with both MS and IMS/MS platforms.ConclusionsSeveral methods of acidification were demonstrated for enhanced vaporization and detection of chlorates and perchlorates. For applications where rapid surface collection and analysis for chlorates and perchlorates are desired, the solid‐state approaches offer the simplest means to integrate the reagent chemistry into MS or IMS detection. Copyright © 2015 John Wiley & Sons, Ltd.
A novel methylation derivatization method for δ18O analysis of individual carbohydrates by gas chromatography/pyrolysis–isotope ratio mass spectrometry
Authors: Lehmann Marco M. , Fischer Maria , Blees Jan , Zech Michael , Siegwolf Rolf T. W. , Saurer Matthias 
Published: December 2015

RationaleThe oxygen isotope ratio (δ18O) of carbohydrates derived from animals, plants, sediments, and soils provides important information about biochemical and physiological processes, past environmental conditions, and geographical origins, which are otherwise not available. Nowadays, δ18O analyses are often performed on carbohydrate bulk material, while compound‐specific δ18O analyses remain challenging and methods for a wide range of individual carbohydrates are rare.MethodsTo improve the δ18O analysis of individual carbohydrates by gas chromatography/pyrolysis–isotope ratio mass spectrometry (GC/Pyr‐IRMS) we developed a new methylation derivatization method. Carbohydrates were fully methylated within 24 h in an easy‐to‐handle one‐pot reaction in acetonitrile, using silver oxide as proton acceptor, methyl iodide as methyl group carrier, and dimethyl sulfide as catalyst.ResultsThe precision of the method ranged between 0.12 and 1.09‰ for the δ18O values of various individual carbohydrates of different classes (mono‐, di‐, and trisaccharides, alditols), with an accuracy of a similar order of magnitude, despite high variation in peak areas. Based on the δ18O values of the main isomers, important monosaccharides such as glucose and fructose could also be precisely analyzed for the first time. We tested the method on standard mixtures, honey samples, and leaf carbohydrates extracted from Pinus sylvestris, showing that the method is also applicable to different carbohydrate mixtures.ConclusionsThe new methylation method shows unrivalled accuracy and precision for δ18O analysis of various individual carbohydrates; it is fast and easy‐to‐handle, and may therefore find wide‐spread application. Copyright © 2015 John Wiley & Sons, Ltd.
Satellite remote sensing to monitor species diversity: potential and pitfalls
Authors: Rocchini Duccio , Boyd Doreen S. , Féret Jean‐Baptiste , Foody Giles M. , He Kate S. , Lausch Angela , Nagendra Harini , Wegmann Martin , Pettorelli Nathalie 
Published: December 2015

AbstractAssessing the level of diversity in plant communities from field‐based data is difficult for a number of practical reasons: (1) establishing the number of sampling units to be investigated can be difficult; (2) the choice of sample design can impact on results; and (3) defining the population of concern can be challenging. Satellite remote sensing (SRS) is one of the most cost‐effective approaches to identify biodiversity hotspots and predict changes in species composition. This is because, in contrast to field‐based methods, it allows for complete spatial coverages of the Earth's surface under study over a short period of time. Furthermore, SRS provides repeated measures, thus making it possible to study temporal changes in biodiversity. Here, we provide a concise review of the potential of satellites to help track changes in plant species diversity, and provide, for the first time, an overview of the potential pitfalls associated with the misuse of satellite imagery to predict species diversity. Our work shows that, while the assessment of alpha‐diversity is relatively straightforward, calculation of beta‐diversity (variation in species composition between adjacent locations) is challenging, making it difficult to reliably estimate gamma‐diversity (total diversity at the landscape or regional level). We conclude that an increased collaboration between the remote sensing and biodiversity communities is needed in order to properly address future challenges and developments.
Gleitfeste Verbindungen im Turm‐ und Mastbau
Authors: Stranghöner Natalie , Afzali Nariman , Berg Jörn 
Published: December 2015

AbstractSchraubenverbindungen im Turm‐ und Mastbau werden immer dann als gleitfest vorgespannte Verbindungen der Kategorien B oder C nach DIN EN 1993‐1‐8 ausgeführt, wenn die Verformungen und der Schlupf in den Verbindungen minimiert werden müssen, wie zum Beispiel bei Funkmasten und Türmen von Windenergieanlagen. Wesentliche Einflussparameter auf die Tragfähigkeit einer gleitfesten Verbindung sind die Höhe der Vorspannkraft in den Schrauben und die Reibeigenschaften der gepaarten Oberflächen – beschrieben durch die Haftreibungszahl. Ein möglichst hoher und über die Lebensdauer der Struktur garantierter Gleitwiderstand ist wünschenswert, um die Anzahl der Schrauben und die Flächen der aufwändig und damit kostenintensiv herzustellenden Verbindungen gering zu halten und der Forderung der Industrie nach wartungsfreien Verbindungen nachzukommen. Aus diesen Gründen erfolgen derzeit umfangreiche Untersuchungen zur Ermittlung der Haftreibungszahl gleitfester Verbindungen auf Basis der DIN EN 1090‐2 im Rahmen des europäischen RFCS‐Forschungsvorhabens SIROCO unter Berücksichtigung unterschiedlicher Vorspannkraftniveaus und Beschichtungsarten, die im vorliegenden Beitrag auszugsweise am Beispiel von Alkali‐Zink‐Silikat beschichteten und spritzverzinkten gleitfesten Oberflächen vorgestellt werden.Slip‐resistant connection in towers and masts – testing and coating. Bolted connections in towers and masts are executed as slip‐resistant connections of categories B or C according to EN 1993‐1‐8 when deformations and slip have to be minimized, e. g. in radio masts and towers of wind turbines. The load bearing capacity of slip‐resistant connections is mainly influenced by the level of preloading in the bolts and the friction of the faying surfaces – described by the slip factor. The highest possible and over the service life of the structure guaranteed slip resistance is desirable in order to keep the number of bolts and the faying surfaces of the complex and therefore expensive connections low and to meet the demand of the industry for maintenance‐free connections. For these reasons, at present, extensive studies on the determination of the slip factor of slip‐resistant connections on the basis of EN 1090‐2 are carried out as part of the European RFCS research project SIROCO taking into account different preloading levels and coating types. Within the present contribution, first results are presented for alkali zinc silicate coated and zinc spray metallized faying surfaces.
Fachgerechter Korrosionsschutz für Türme und Maste aus Stahl
Authors: Gehrke Jörg , Lebelt Peter 
Published: December 2015

AbstractDer Einsatz von Korrosionsschutzsystemen, bestehend aus organischen Beschichtungssystemen oder metallischen Überzügen, wird in teils umfangreichen technischen Regelwerken für die Anwendung auf dünnem Blech bis 3 mm Blechdicke bis hin zu massiven Stahlbaukonstruktionen mit Tragsicherheitsnachweis umfassend beschrieben. Nach Bestimmung der vor Ort vorhandenen Korrosivitätskategorie und Festlegung der gewünschten Schutzdauer können geeignete Korrosionsschutzsysteme für ein bestimmtes Objekt aus Tabellen ausgewählt werden. Des Weiteren lassen sich zahlreiche Hinweise zur korrosionsschutzgerechten Konstruktion, zur Oberflächenvorbereitung und ‐vorbehandlung des Substrates und zu den Verarbeitungsbedingungen des Korrosionsschutzsystems in einschlägigen Regelwerken finden. Ein fachgerechter Korrosionsschutz an Stahlkonstruktionen muss durch Umsetzung der in Regelwerken genannten Qualitätssicherungsmaßnahmen sowohl bei der Planung als auch bei der Ausführung der Korrosionsschutzarbeiten erfolgen.Professional corrosion protection for towers and masts made of steel. The usage of corrosion protection systems, consisting of organic or metallic coatings, are comprehensively described in partly extensive technical rules for the application on thin metal sheets (3 mm sheet thickness maximum) up to massive steel structures with ultimate limit state design. After determining of existing on‐site corrosion category and defining the desired term of protection time, the appropriate corrosion protection systems for a particular object can be selected from tables. Furthermore, numerous comments can be found for corrosion‐resistant construction, for surface preparation and pretreatment of the substrate and the processing conditions of the corrosion protection system in the relevant regulations. A professional corrosion protection for steel structures must be carried out by implementation of technical rules mentioned in quality assurance measures, both in planning and in the execution of corrosion protection work.
DPPA5 Supports Pluripotency and Reprogramming by Regulating NANOG Turnover
Authors: Qian Xu , Kim Jin Koo , Tong Wilbur , Villa-Diaz Luis G. , Krebsbach Paul H. 
Published: December 2015

Abstract
Although a specific group of transcription factors such as OCT4, SOX2, and NANOG are known to play essential roles in pluripotent stem cell (PSC) self-renewal, pluripotency, and reprogramming, other factors and the key signaling pathways regulating these important properties are not completely understood. Here, we demonstrate that the PSC marker Developmental Pluripotency Associated 5 (DPPA5) plays an important role in human PSC (hPSC) self-renewal and cell reprogramming in feeder-free conditions. Compared to hPSCs grown on mouse embryonic fibroblasts, cells cultured on feeder-free substrates, such as Matrigel, Laminin-511, Vitronectin, or the synthetic polymer poly[2-(methacryloyloxy) ethyl dimethyl-(3-sulfopropyl) ammonium hydroxide], had significantly higher DPPA5 gene expression and protein levels. Overexpression of DPPA5 in hPSCs increased NANOG protein levels via a post-transcriptional mechanism. Coimmunoprecipitation, protein stability assays, and quantitative RT-PCR, demonstrated that DPPA5 directly interacted, stabilized, and enhanced the function of NANOG in hPSCs. Additionally, DPPA5 increased the reprogramming efficiency of human somatic cells to induced pluripotent stem cells (hiPSCs). Our study provides new insight into the function of DPPA5 and NANOG regulation in hPSCs.