bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of pollen extraction methods confirms dense‐media separation as a reliable method of pollen preparation
Authors: Campbell J. F. E. , Fletcher W. J. , Hughes P. D. , Shuttleworth E. L. 
Published: August 2016

ABSTRACTPalynology is a crucial proxy for understanding Quaternary environmental change. A range of laboratory preparation techniques has been developed to deal with the extraction of pollen in different sedimentary contexts. Here, we present a comparison of the conventional hydrofluoric acid method and the dense‐media separation method using sodium polytungstate. We examine pollen, non‐pollen palynomorphs (NPPs) and microcharcoal by undertaking parallel preparation and counting of 30 paired samples from three sites in the Middle Atlas Mountains, Morocco, with contrasting environmental and sedimentary conditions. Differences between microfossil counts are assessed visually and statistically, using ANOVA and linear regression. We observe that the typical offset between counts for the five most common pollen and NPPs produced by the two methods (µ = 1.6%, SD = 0.9%) is considerably smaller than the 95% uncertainty associated with the standard counting procedure (µ = 6.8%, SD = 2.7%). There is no statistically significant difference associated with the preparation methods, and no significant deviation from a linear relationship between the results obtained by the two methods. There are advantages and disadvantages to both methods in terms of preparation time and visual characteristics. This study confirms that results for pollen, NPPs and microcharcoal obtained by either preparation method can be directly compared.
Maintain Spatial Heterogeneity, Maintain Biodiversity—A Seed Bank Study in a Grazed Alpine Fen Meadow
Authors: Xu Ling‐xiang , Cao Yu , Li Wei , Cheng Yu , Qin Tong‐chun , Zhou Yuan‐chang , Liu Fan 
Published: August 2016

AbstractWetland degradation is a source of anxiety and is more severe in cold regions than other areas. The soil seed bank acts as a propagule source for revegetation to affiliate the restoration of degraded wetlands. However, the effects of this approach are controversial and depend on the traits of the seed bank and its interactions with the environment. The seed bank in an alpine fen meadow was studied to determine its exact role in revegetation. The surveyed shore of a Tibetan lake, Gahai Lake, was divided into three sites under different levels of grazing pressure. Each site was separated into six transects along a water‐depth gradient to collect soil cores to determine the pattern of biodiversity through a germination experiment in a greenhouse. After an analysis of heterogeneity‐related diversity, partitioning of 58 discovered species indicated that 39.5 could be contributed to beta‐diversity, which was mainly contributed to water depth. Overgrazing (0.607 sheep unit/acre, November—March) decreased seed bank diversity in many respects, especially through decreasing spatial heterogeneity and homogenizing biota. A lightly grazed, well‐protected site had not only the highest beta‐diversity and species abundance but also the highest inter‐site species turnover rate compared with other sites under moderate grazing intensity. Despite the lack of target species, the seed bank serves as (i) a species‐rich pool; (ii) an extant legacy seed source for sustaining heterogeneity and floristic diversity; and (iii) an ecological indicator, and its effect can be reinforced by appropriate grazing practices (multiple intensity) and hydrological modifications. Copyright © 2016 John Wiley & Sons, Ltd.
Modeling of Polyolefin Polymerization in Semibatch Slurry Reactors: Experiments and Simulations
Authors: Casalini Tommaso , Visscher Frans , Janssen Erik , Bertola Francesco , Storti Giuseppe , Morbidelli Massimo 
Published: August 2016

In this work, a well‐known single‐particle model (the multigrain model) is applied to simulate size growth and morphology evolution of polyethylene particles obtained through a slurry phase, catalytic polymerization in semibatch reactor. The model explicitly accounts for diffusion limitations within the polymer particle and between the particle and the solvent, as well as void fraction variations due to the particle growth. Catalyst behavior is described assuming a two‐site model, a good compromise between accuracy and simplicity, along with a conventional kinetic scheme, whose kinetic parameters are determined by fitting the model predictions to the experimental data. Polymer molecular weight is evaluated from population balances, solved through the method of moments. The semibatch reactor is modeled by means of fundamental mass conservation equations. Simulations show that the proposed model is able to describe not only the polymer properties of interest but also the evolution of the average particle size, thus providing a comprehensive overview of the system behavior. The model is further validated through regression‐free simulation of additional sets of experimental data, including materials with a bimodal molar mass distribution: the good agreement also found in this case confirms the robustness of the model and the estimated parameter values.image
Chemie als Zukunftswissenschaft
Authors: Lindhorst Thisbe K. 
Published: August 2016

AbstractIm Jahr 1867 gründete sich in Berlin die Deutsche Chemische Gesellschaft, die ältere der beiden Vorgängerorganisationen der Gesellschaft Deutscher Chemiker. Doch der Blick zurück reicht nicht aus, denn die Frage lautet: Was bringt die Zukunft uns und was bringen wir der Zukunft?
Hydrostatic pressure and muscarinic receptors are involved in the release of inflammatory cytokines in human bladder smooth muscle cells
Authors: Liang Zhou , Xin Wei , Qiang Liu , Xiang Cai , Bang‐Hua Liao , Jin Yang , De‐Yi Luo , Hong Li , Kun‐Jie Wang 
Published: August 2016

AimsAbnormal intravesical pressure results in a series of pathological changes. We investigated the effects of hydrostatic pressure and muscarinic receptors on the release of inflammatory cytokines in rat and human bladder smooth muscle cells (HBSMCs).MethodsAnimal model of bladder outlet obstruction was induced by urethra ligation. HBSMCs were subjected to elevated hydrostatic pressure and/or acetylcholine (Ach). Macrophage infiltration in the bladder wall was determined by immunohistochemical staining. The expression of inflammatory genes was measured by RT‐PCR, ELISA and immunofluorescence.ResultsIn obstructed bladder, inflammatory genes and macrophage infiltration were remarkably induced. When HBSMCs were subjected to 200–300 cm H2O pressure for 2–24 h in vitro, the expressions of IL‐6 and RANTES were significantly increased. Hydrostatic pressure promoted the protein levels of phospho‐NFκB p65 and phospho‐ERK1/2 as well as muscarinic receptors. Moreover, NFκB or ERK1/2 inhibitors suppressed pressure‐induced inflammatory genes mRNA. When cells were treated with 1 μM acetylcholine for 6 h, a significant increase in IL‐6 mRNA expression was detected. Acetylcholine also enhanced pressure‐induced phospho‐NFκB p65 and IL‐6 protein expression. Additionally, pressure‐induced IL‐6 was partially suppressed by muscarinic receptors antagonists.ConclusionsHydrostatic pressure and muscarinic receptors were involved in the secretion of inflammatory cytokines in HBSMCs, indicating a pro‐inflammatory effect of the two factors in the pathological process of BOO.
Establishing stable time‐steps for DEM simulations of non‐collinear planar collisions with linear contact laws
Authors: Burns Shane J. , Hanley Kevin J. 
Published: August 2016

SummaryThe discrete element method, developed by Cundall and Strack, typically uses some variations of the central difference numerical integration scheme. However, like all explicit schemes, the scheme is only conditionally stable, with the stability determined by the size of the time‐step. The current methods for estimating appropriate discrete element method time‐steps are based on many assumptions; therefore, large factors of safety are usually applied to the time‐step to ensure stability, which substantially increases the computational cost of a simulation. This work introduces a general framework for estimating critical time‐steps for any planar rigid body subject to linear damping and forcing. A numerical investigation of how system damping, coupled with non‐collinear impact, affects the critical time‐step is also presented. It is shown that the critical time‐step is proportional to
if a linear contact model is adopted, where m and k represent mass and stiffness, respectively. The term which multiplies this factor is a function of known physical parameters of the system. The stability of a system is independent of the initial conditions. © 2016 The Authors. International Journal for Numerical Methods in Engineering Published by John Wiley & Sons Ltd.
Prospective study of neuropathic pain after definitive surgery for extremity osteosarcoma in a pediatric population
Authors: Anghelescu Doralina L. , Steen Brenda D. , Wu Huiyun , Wu Jianrong , Daw Najat C. , Rao Bhaskar N. , Neel Michael D. , Navid Fariba 
Published: August 2016

AbstractBackgroundNeuropathic pain (NP) after definitive surgery for extremity osteosarcoma (OS) has not been previously characterized. This study prospectively investigates the incidence, duration, and treatment of NP in limb sparing surgery and amputation groups.ProcedureIn patients treated for OS on a chemotherapy and definitive surgery (limb sparing vs. amputation) protocol (OS08), we prospectively collected the following data: (i) demographical data (age, sex, race); (ii) NP time of onset and duration; and (iii) dose (starting, maximum) and duration of gabapentin, amitriptyline, and methadone treatment.ResultsThirty‐seven patients underwent 38 definitive surgeries: limb sparing (26, 68.4%) or amputations (12, 31.6%). Localization included lower extremity (30, 81%), upper extremity (6, 16%), or pelvis (1, 3%). Thirty patients (81%) developed NP and 26 of them required NP‐specific medications (87.7%). The mean [standard deviation (SD)] duration of NP was 6.5 weeks (7.2) (median 4.4, range 0.3–29.9). All 26 patients (27 surgeries) treated with NP medications received gabapentin, either as single therapy (65.4%) (17 patients, 18 surgeries), dual therapy with gabapentin and amitriptyline (five patients), or triple therapy with gabapentin, amitriptyline, and methadone (four patients). The mean starting (maximum) doses of gabapentin, amitriptyline, and methadone (mg/kg/day) were 20.2 (43.8), 0.5 (0.7), and 0.3 (0.3), respectively. The incidence and duration of NP, duration of treatment, and NP‐specific dose regimens were similar in the limb sparing and the amputation groups.ConclusionsNP after definitive surgery for OS is frequently encountered, can persist for a significant time, and NP outcomes are similar in limb sparing and amputation groups.
Development and evaluation of iManage: A self‐management app co‐designed by adolescents with sickle cell disease
Authors: Crosby Lori E. , Ware Russell E. , Goldstein Alana , Walton Ashley , Joffe Naomi E. , Vogel Craig , Britto Maria T. 
Published: August 2016

AbstractBackgroundAdolescents and young adults (AYAs) with sickle cell disease (SCD) are a vulnerable population with high risk of morbidity that could be decreased with effective self‐management. Previous research suggests that mobile applications (apps) may facilitate AYA engagement in health‐promoting behaviors. The objectives of this study were: (i) describe Internet access and use in AYA with SCD; (ii) identify barriers for self‐management in this population; (iii) collaborate with AYA to co‐design a mobile app that would minimize barriers; and (iv) evaluate the feasibility and acceptability of the app.ProcedureIn phase 1, 46 AYAs with SCD 16–24 years of age completed a survey of Internet access and use. During phase 2, 19 AYAs with SCD (average age 20 ± 2.5 years) and eight healthcare providers participated in interviews to identify barriers and co‐design sessions to develop the app. In phase 3, five AYAs with SCD completed app feasibility and usability testing.ResultsAYAs with SCD had daily Internet access (69%) using their computers (84%) or mobile phones (70%). Participants went online for health information (71%) and preferred Web sites with interactive/social features (83%). Barriers to self‐management included failing to believe that their health would suffer, lack of tailored self‐management support, lack of a mechanism to visualize self‐management progress, and limited opportunities for peer interaction around self‐management. The prototype app (iManage) was rated as highly feasible and beneficial.ConclusionsA mobile app prototype co‐designed by AYAs with SCD may be a useful tool for engaging them in self‐management strategies designed to improve health.
Reducing ocean model imbalances in the equatorial region caused by data assimilation
Authors: Waters J. , Bell M. J. , Martin M. J. , Lea D. J. 
Published: August 2016

The equatorial region is a particularly challenging area for ocean data assimilation. In this region the dominant balance near the surface is between the ocean pressure gradients and the applied wind stress. When increments are applied to an ocean model near the Equator, the pressure gradients are modified and this can cause an imbalance with the unchanged wind stress. This can lead to an initialization shock where spurious equatorial waves and vertical velocities are triggered. The equatorial waves can degrade the performance of the ocean model while the increased vertical velocities have a significant negative impact on biogeochemical models forced by these physical ocean fields. Previous studies have proposed a scheme to reduce the ocean biases associated with slowly varying errors in the applied wind stress by applying a pressure correction calculated from accumulated temperature and salinity increments. This scheme has previously been shown to reduce the mean vertical velocities and improve modelled circulation. However, when applying this scheme, we still see equatorial imbalances from data assimilation on shorter time‐scales.We consider a new method which is an extension of the pressure correction and aims to act as a balance to the equatorial increments and reduce intialization shock. We refer to this as an incremental pressure correction. We provide a description of this method and an analysis of its energetics. In initial experiments with a global ocean data assimilation system, this new method is shown to suppress the generation of equatorial waves in a single observation experiment and to significantly reduce the standard deviation of vertical velocities in a re‐analysis experiment.
Computational approaches to the prediction of the redox potentials of iron and copper bioinorganic systems
Authors: Bruschi Maurizio , Breglia Raffaella , Arrigoni Federica , Fantucci Piercarlo , De Gioia Luca 
Published: August 2016

AbstractAim of this contribution is to review some recent quantum mechanical approaches used to compute the redox potentials of transition metal complexes, with the emphasis on copper and iron species, which are particularly relevant in inorganic biochemistry and in synthetic chemistry of bio‐mimetic compounds. The paper presents also new DFT results obtained on Cu and Fe aquo ions in the framework of the Thermodynamic Integration and Grand Canonical Ensemble approaches. Such results show that without explicit inclusion of water molecules in the external solvation shells (even using a continuum solvation model) also very advanced methodologies fail to predict the redox potential in an acceptable manner. This is a confirmation of some previous studies which however never addressed this specific problem along the aforementioned approaches. Better results are obtained, on the contrary, on a series of Cu(II) complexes with Gly, Ala, en, Im, and water ligands with coordination type
or N4. In this case, the complexes are surrounded by nine water molecules which may partially alleviate the inadequacy of the continuum solvent models, especially in the case of highly positively charged species.
Towards a secure hybrid adaptive gateway discovery mechanism for intelligent transportation systems
Authors: Boukerche Azzedine , Aljeri Noura , Abrougui Kaouther , Wang Yan 
Published: August 2016

AbstractIn the recent years, we are witnessing a growing interest into the design of smart vehicles and smart roads for Intelligent transportation systems. Vehicles as part of the Internet of Things should provide to the driver and passenger with a variety of services using efficient gateway discovery mechanism while maintaining a certain level of security and authentication to avoid potential malicious attacks. In this paper, we propose a secure hybrid adaptive gateway discovery and communication protocol for smart vehicular networks, which we refer to as SEGAL. Our proposed SEGAL protocol is based upon building a secure clustered vehicular network, and permits the exchange of gateway discovery messages through authenticated clusterheads and cluster members. We shall present the design of our protocol, and describe how it can overcome the possible malicious attacks that might harm the network. Then, we report its efficiency and scalability using an extensive set of simulation experiments using Ns‐2 simulator. Our results indicate that the proposed SEGAL protocol is scalable while achieving high success rate, low response time and dropping rate. Copyright © 2016 John Wiley & Sons, Ltd.
Theoretical and Experimental Study of the Antioxidant Behaviors of 5‐O‐Caffeoylquinic, Quinic and Caffeic Acids Based on Electronic and Structural Properties
Authors: Uranga Jorge G. , Podio Natalia S. , Wunderlin Daniel A. , Santiago Ana N. 
Published: August 2016

AbstractThe aim of this study was to elucidate the structural and electronic factors that determine the antioxidant capacity of 5‐O‐caffeoylquinic, caffeic and quinic acids under different experimental conditions. Antioxidant capacity was measured using different in vitro assays, involving diverse mechanisms of antioxidant action, namely, radical scavenging or reduction. The mechanisms of these reactions were analyzed by a theoretical study using the Density Functional Theory. Results allow relating in vitro antioxidant capacity of these three compounds with their chemical structures. The antioxidant capacity experimentally observed for these three acids was interpreted considering the reaction mechanism involved, the nature and stability of the intermediate formed, the formation and reaction of secondary compounds, and the effect of the reaction medium. The main goal of this report is presenting a theoretical analysis of reactions implicated in the antioxidant capacity, identifying the causes that increase or decrease such property. Thus, we present a quantum mechanical description of the antioxidant properties involved with these three compounds, considering equilibria and secondary oxidations involved.
Influence of Halogen Atoms on Spin‐Crossover Properties of 1,2,4‐Triazole‐Based 1D Iron(II) Polymers
Authors: Luo Yang‐Hui , Sun Yu , Liu Qing‐ling , Yang Li‐Jing , Wen Gao‐Ju , Wang Ming‐Xin , Sun Bai‐Wang 
Published: August 2016

AbstractThe introduce of halogen atoms (F, Cl, Br, I) to the triazole‐based ligand N‐benzyl‐4‐amino‐1, 2, 4‐triazole (L) have shown a significant effect on the spin‐crossover (SCO) properties of the corresponding one‐dimensional (1D) coordination Fe (II) polymers with chemical formula [Fe(4‐X–L)3](BF4)2 (X=F, Cl, Br, and I). Compared with the [FeL3](BF4)2, the electronegative halogen atoms have increased the π‐acceptor character of these ligands, which thus improved the ligand field strength and induced the occurrence of SCO for the Fe (II) polymers at higher temperatures. The SCO transition temperatures T1/2 have changed from 200 K to 249 (I), 250 (Br), 252 (Cl) and 275 (F) K, respectively. More importantly, the UV‐Vis absorption spectrum and density functional theory (DFT) calculations indicated that the transition temperatures and the width of thermal hysteresis loops have shown a positive correlation with the electronegativity of the halogen atoms.
Functionalized Multi‐Walled Carbon Nanotubes (f‐MWCNT) as Highly Efficient and Reusable Heterogeneous Catalysts for the Synthesis of Acridinedione Derivatives
Authors: Ulus Ramazan , Yıldız Yunus , Eriş Sinan , Aday Burak , Şen Fatih , Kaya Muharrem 
Published: August 2016

AbstractAddressed herein, carboxylic acid groups were immobilized onto carbon nanotubes and their catalytic properties were examined for the first time for the synthesis of acridinedione derivatives, opening new paths in the investigation of catalysis and their comparison with carbon‐based materials. An efficient methodology for the synthesis of acridinedione derivatives has been achieved by one‐pot, multi‐component condensation of dimedone, substitute aromatic aldehydes, various aromatic amines and, in the presence of the easily available, inexpensive, and nontoxic f‐MWCNTs as versatile biodegradable catalysts. At this method, f‐MWCNTs carrying simple carboxylic acid functionalities catalyze the model reaction in ethanol providing the product in a quantitative yield. This highly monodisperse catalyst is one of the most efficient catalysts which gives the highest yield of products in the shortest time. Its high‐yield efficiency, clean, eco‐friendly, simple work‐up procedure, and easy purification are regarded to be the main advantages of this method. The synthesized compounds are characterized using spectroscopic (IR, 1H‐NMR, 13C‐NMR and HRMS) techniques.
The Quantitative Evaluations of the Luminescent Sensing Ability to Cu2+ Based on Two Homologous Crystalline Coordination Polymers
Authors: Pang Ling‐Yan , Bai Nan‐Nan , Jin Jun‐Cheng , Yang Guo‐Ping , Wu Yun‐Long , Luan Xin‐Jun , Wang Yao‐Yu 
Published: August 2016

AbstractA systematic study has been well conducted on two new homologous Cd(II)‐based luminescent coordination polymers (LCPs), [Cd3(Httac)2(H2O)8]⋅(H2O)2 (1) and [Cd2(ttac)(H2O)6]⋅(H2O)6 (2), (H4ttac=1,1′,2′,1′′‐terphenyl‐4,4′,4′′,5′‐tetracarboxylic acid), to explore their sensing mechanisms to Cu2+. Both 1 and 2 are able to respond to Cu(NO3)2 through luminescent quenching but with the distinct quenching modes. The Stern‐Volmer curves of 1 and 2 both deviate from the linearity, indicating the coexistence of the dynamic and static quenching. Concentration‐dependent lifetime experiments have been carried out carefully to confirm the dynamic quenching and to calculate the dynamic constants quenching Kc; the static quenching is supported by time‐dependent intensity measurements where the intensities of 1 decrease along with time, while for 2, it's a constant in time; the corresponding constants Ks have also been obtained, thus achieving the quantitative evaluations of quenching processes. More importantly, the relationships between the sensing efficiency and inherent structures of two LCPs have been discussed, and the promotion suggestions have also been given finally.