bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Numerical Research on Limits of the Dispersion Model
Authors: Song Feifei , Schmid Thomas , Häfeli Richard , von Rohr Philipp Rudolf 
Published: April 2017

AbstractThe axial dispersion in tubular reactors is frequently modeled by the dispersion model, which is an analytical solution under the assumption that the vessel dispersion number is sufficiently small. In this study, limits until which the analytical solution is valid are investigated by comparison with the numerical method. The results show that it is applied only if the vessel dispersion number is small enough and the entrance effect of the tracer is avoided. Therefore, an algorithm based on the numerical solution of the control equation of dispersion is proposed, which allows for higher vessel dispersion numbers.
Roles of Hydroxyl Groups During Side‐Chain Alkylation of Toluene with Methanol over Zeolite Na‐Y: A Density Functional Theory Study
Authors: Li Xu , Lu Junran , Li Yi , Yu Jihong 
Published: April 2017

AbstractThe side‐chain alkylation of toluene with methanol over alkali‐cation‐containing zeolite Y is an important reaction for industrial production of styrene, but the exact mechanism of this reaction is still unclear. The most accepted opinion is that the Lewis acid–base sites in zeolite Y activate the transformation from methanol to formaldehyde, the side‐chain alkylation of toluene with formaldehyde, and the formation of 2‐phenylethanol and styrene afterwards. In this study, we investigate the roles of various types of hydroxyl groups that could possibly exist in zeolite Na‐Y during this reaction, including the Brönsted acid sites and the terminal Al—OH and Si—OH groups, respectively. Through density functional theory (DFT) calculations, we find that the Brönsted acid sites in Na‐Y may catalyze the ring alkylation of toluene and be responsible for the formation of xylene, a side product discovered in experiments. More importantly, we find, for the first time, a new reaction pathway from 2‐phenylethanol to styrene over various types of hydroxyl groups in Na‐Y, which is kinetically more favorable than the conventional pathway. According to our calculation results, the most possible mechanism for this styrene production process may involve reactions over both the Lewis acid–base sites and the hydroxyl groups in Na‐Y.
Chromatographic Resolution of α‐Amino Acids by (R)‐(3,3'‐Halogen Substituted‐1,1'‐binaphthyl)‐20‐crown‐6 Stationary Phase in HPLC
Authors: Wu Peng , Wu Yuping , Zhang Junhui , Lu Zhenyu , Zhang Mei , Chen Xuexian , Yuan Liming 
Published: April 2017

AbstractThree new chiral stationary phases (CSPs) for high‐performance liquid chromatography were prepared from R‐(3,3'‐halogen substituted‐1,1'‐binaphthyl)‐20‐crown‐6 (halogen = Cl, Br and I). The experimental results showed that R‐(3,3'‐dibromo‐1,1'‐binaphthyl)‐20‐crown‐6 (CSP‐1) possesses more prominent enantioselectivity than the two other halogen‐substituted crown ether derivatives. All twenty‐one α‐amino acids have different degrees of separation on R‐(3,3'‐dibromo‐1,1'‐binaphthyl)‐20‐crown‐6‐based CSP‐1 at room temperature. The enantioselectivity of CSP‐1 is also better than those of some commercial R‐(1,1'‐binaphthyl)‐20‐crown‐6 derivatives. Both the separation factors (α) and the resolution (Rs) are better than those of commercial crown ether‐based CSPs [CROWNPAK CR(+) from Daicel] under the same conditions for asparagine, threonine, proline, arginine, serine, histidine and valine, which cannot be separated by commercial CR(+). This study proves the commercial usefulness of the R‐(3,3'‐dibromo‐1,1'‐binaphthyl)‐20‐crown‐6 chiral stationary phase.
Comparing outcomes of matched related donor and matched unrelated donor hematopoietic cell transplants in adults with B‐Cell acute lymphoblastic leukemia
Authors: Segal Eric , Martens Michael , Wang Hai‐Lin , Brazauskas Ruta , Weisdorf Daniel , Sandmaier Brenda M. , Khoury H. Jean , de Lima Marcos , Saber Wael 
Published: April 2017

BACKGROUNDAllogeneic hematopoietic cell transplantation (HCT) using human leukocyte antigen (HLA)–matched related donors (RDs) and allogeneic HCT using HLA‐matched unrelated donors (URDs) produce similar outcomes for patients with acute myelogenous leukemia, whereas the donor source has been reported to be a predictor of outcomes in myelodysplastic syndrome.METHODSPost‐HCT outcomes for 1458 acute lymphoblastic leukemia patients from 2000 to 2011 were analyzed, and RD and URD transplants were compared.RESULTSThe median age was 37 years (range, 18‐69 years). In the multivariate analysis, HLA 8/8 allele–matched URD recipients had similar transplant‐related mortality (TRM) and all‐cause mortality in comparison with RD recipients (hazard ratios [HRs], 1.16 [95% confidence interval (CI), 0.91‐1.48] and 1.01 [95% CI, 0.85‐1.19], respectively); 7/8 URD recipients had a greater risk of TRM and all‐cause mortality in comparison with RD recipients (HRs, 1.92 [95% CI, 1.47‐2.52] and 1.29 [95% CI, 1.05‐1.58], respectively). The risk of TRM and all‐cause mortality was also greater for 7/8 URD recipients versus 8/8 URD recipients. Compared with RD recipients, both 8/8 and 7/8 URD recipients had a lower risk of relapse (HRs, 0.77 [95% CI, 0.62‐0.97] and 0.75 [95% CI, 0.56‐1.00], respectively). Both 8/8 and 7/8 URD recipients had a greater risk of acute graft‐versus‐host disease (GVHD; HRs, 2.18 [95% CI, 1.76‐2.70] and 2.65 [95% CI, 2.06‐3.42], respectively) and chronic GVHD (HRs, 1.28 [95% CI, 1.06‐1.55] and 1.46 [95% CI, 1.14‐1.88], respectively) in comparison with RD recipients.CONCLUSIONSIn the absence of RD transplantation, 8/8 URD transplantation is a viable alternative with similar survival outcomes, whereas 7/8 URD transplantation is associated with poorer overall survival. Cancer 2017;123:3346‐55. © 2017 American Cancer Society.
Rational Hydrogel Formulation Leads to Reversible and Enhanced Photocontrolled Rigidity
Authors: Royes Mir Jorge , Coudret Christophe , Roux Clément , Benoit‐Marquié Florence , Cazalès Martine , Séverac Childerick , Lorenzo Corinne , Mingotaud Anne‐Françoise 
Published: April 2017

AbstractStimuli‐responsive hydrogels are essential for the future development of synthetic materials that could exchange information with living tissues. In this Article, we present the synthesis of biocompatible hydrogels with an unprecedented range of photocontrolled rigidity. The hydrogels are based on dual physical and chemical crosslinking. Chemical crosslinks are the result of thiol maleimide Michael addition; physical crosslinks are based on host–guest interactions between azobenzene and β‐cyclodextrin moieties. The final properties of the materials are tuned by a design‐of‐experiment approach. This strategy enables us to obtain a hydrogel with mechanical properties close to routinely used agarose gel while maintaining a low UV‐visible absorption. The Young's modulus is monitored in real time during AFM nanoindentation experiments under irradiation. Upon UV and visible irradiation cycles, the hydrogel exhibits a range of reversible evolution greater than 30 %, which is also associated with cycles of swelling/shrinking. A biocompatible hydrogel with predictable and phototunable stiffness and a high variation in mechanical properties has thus been obtained for the first time.
Optimizing the Near‐Infrared Performance of Photorefractive Composites by Chemical Modification of the Sensitizer
Authors: Koeber Sebastian , Seidenspinner Andreas , Meerholz Klaus , Krüger Hartmut , Janietz Silvia 
Published: April 2017

AbstractThe influence of structural changes of a naphthalene–bisimide sensitizer on the photorefractive behavior of the respective polymeric composites is reported. By increasing the number of attached thiophene units, the band gap of the sensitizer was gradually reduced, leading to an increased absorption cross‐section of the photorefractive materials. However, the electron‐accepting capabilities as well as the relative content of the sensitizer in the composites remained unchanged for the whole series. The increased absorption had a remarkably beneficial effect on both the steady‐state as well as the dynamic performance of the composites, leading to a material which is able to outperform the former fastest and most sensitive material at the utilized wavelength by a factor of two.
Design of robust digitally controlled DC–DC converters in the presence of strong interference
Authors: Hayes Brendan , Condon Marissa , Giaouris Damian 
Published: April 2017

AbstractOne of the main advantages of digital control is the ability to design more sophisticated control strategies to enable high‐performance dc–dc converters. One such example is a buck converter operating with a digital state‐feedback controller. Previous works characterise the nonlinear dynamics of such systems under ideal operating conditions. However, in practical applications, these conditions cannot be guaranteed. The focus of this work is on the behaviour of such systems when they operate in the presence of strong interference signals. Previous works on the effect of noise have shown that intermittent operation is possible when the frequency of the noise signal is close to the switching frequency. Intermittent operation can be characterised by long periods of stable operation interspersed with periods of unstable or chaotic operation, which greatly downgrade the efficiency and performance of the converter and reduce its lifetime as for example increase the current ripple or add extra AC components at its output. Typically, such behaviour is avoided by modifying the circuit parameters. However, little or no work exists on developing design guidelines in order to effect its elimination. This is the focus of this research, that is, by utilising Filippov's theory on discontinuous differential equations, to set out a design procedure that can be applied to any dc–dc converter, to tune its controller in order to eliminate intermittent operation. As a case study, the digitally controlled buck converter with a state‐feedback control law is selected. Copyright © 2017 John Wiley & Sons, Ltd.
A new parameterization for integrated population models to document amphibian reintroductions
Authors: Duarte Adam , Pearl Christopher A. , Adams Michael J. , Peterson James T. 
Published: April 2017

AbstractManagers are increasingly implementing reintroduction programs as part of a global effort to alleviate amphibian declines. Given uncertainty in factors affecting populations and a need to make recurring decisions to achieve objectives, adaptive management is a useful component of these efforts. A major impediment to the estimation of demographic rates often used to parameterize and refine decision‐support models is that life‐stage‐specific monitoring data are frequently sparse for amphibians. We developed a new parameterization for integrated population models to match the ecology of amphibians and capitalize on relatively inexpensive monitoring data to document amphibian reintroductions. We evaluate the capability of this model by fitting it to Oregon spotted frog (Rana pretiosa) monitoring data collected from 2007 to 2014 following their reintroduction within the Klamath Basin, Oregon,USA. The number of egg masses encountered and the estimated adult and metamorph abundances generally increased following reintroduction. We found that survival probability from egg to metamorph ranged from 0.01 in 2008 to 0.09 in 2009 and was not related to minimum spring temperatures, metamorph survival probability ranged from 0.13 in 2010–2011 to 0.86 in 2012–2013 and was positively related to mean monthly temperatures (logit‐scale slope = 2.37), adult survival probability was lower for founders (0.40) than individuals recruited after reintroduction (0.56), and the mean number of egg masses per adult female was 0.74. Our study is the first to test hypotheses concerning Oregon spotted frog egg‐to‐metamorph and metamorph‐to‐adult transition probabilities in the wild and document their response at multiple life stages following reintroduction. Furthermore, we provide an example to illustrate how the structure of our integrated population model serves as a useful foundation for amphibian decision‐support models within adaptive management programs. The integration of multiple, but related, data sets has an advantage of being able to estimate complex ecological relationships across multiple life stages, offering a modeling framework that accommodates uncertainty, enforces parsimony, and ensures all model parameters can be confronted with monitoring data.
Characterizing ontogenetic habitat shifts in marine fishes: advancing nascent methods for marine spatial management
Authors: Galaiduk Ronen , Radford Ben T. , Saunders Benjamin J. , Newman Stephen J. , Harvey Euan S. 
Published: April 2017

AbstractNiche requirements and habitat resource partitioning by conspecific fishes of different sizes are significant knowledge gaps in the species distribution modelling domain. Management actions and operations are typically concentrated on static habitats, or specific areas of interest, without considering movement patterns of species associated with ontogenetic shifts in habitat usage. Generalized additive models were used to model the body‐length–habitat relationships of six fish species. These models were used to identify subsets of environmental parameters that drive and explain the continuous length–habitat relationships for each of the study species, which vary in their degree of ecological and/or commercial importance. Continuous predictive maps of the length distributions for each of the six study species across approximately 200 km2 of the study area were created from these models. The spatial patterns in habitat partitioning by individuals of different body lengths for all six study species provide strong evidence for ontogenetic shifts. This highlights the importance of considering ontogenetic processes for marine spatial management. Importantly, predictive hotspot maps were created that identify potential areas that accumulate individuals of similar life stages of multiple species (e.g., multispecies nursery areas). In circumstances where limited resources are available for monitoring and management of fish resources, predictive modelling is a valuable tool for studying previously overlooked processes such as ontogenetic habitat shifts. Predictive modelling provides crucial information that elucidates spatial patterns in community composition across mosaics of benthic habitats. This novel technique can contribute to the spatial management of coastal fish and fisheries by identifying areas that are important for different life history stages of multiple fish species.
Influence of pollen limitation and inbreeding depression in the maintenance of incomplete dichogamy in Salvia elegans
Authors: Rosas‐Guerrero Víctor , Hernández Diego , Cuevas Eduardo 
Published: April 2017

AbstractThe widespread presence of incomplete dichogamy (i.e., partial separation in time between male and female phases) in flowering plants is a long‐standing question in floral evolution. In this study, we proposed four scenarios in which depending on the particular combination of pollen limitation and inbreeding depression, the presence of complete dichogamy, incomplete dichogamy, or adichogamy may be favored. Moreover, we evaluated the role of pollen limitation and inbreeding depression in a natural population of Salvia elegans to test the validity of our predicted scenarios. Our results indicate that S. elegans is partially protandrous as pollen viability and stigma receptivity overlap in the last days of life of the flower. Furthermore, through pollination treatments, we found no evidence of pollen limitation or inbreeding depression in any of the evaluated fitness components. As expected by one of the proposed scenarios, incomplete dichogamy seems to be favored in plants with absence of inbreeding depression and pollen limitation as a way to diminish interference between male and female functions.
Coevolution leaves a weak signal on ecological networks
Authors: Ponisio Lauren C. , M'Gonigle Leithen K. 
Published: April 2017

AbstractOne of the major challenges in evolutionary ecology is to understand how coevolution shapes species interaction networks. Important topological properties of networks such as nestedness and modularity are thought to be affected by coevolution. However, there has been no test whether coevolution does, in fact, lead to predictable network structure. Here, we investigate the structure of simulated bipartite networks generated under different modes of coevolution. We ask whether evolutionary processes influence network structure and, furthermore, whether any emergent trends are influenced by the strength or “intimacy” of the species interactions. We find that coevolution leaves a weak and variable signal on network topology, particularly nestedness and modularity, which was not strongly affected by the intimacy of interactions. Our findings indicate that network metrics, on their own, should not be used to make inferences about processes underlying the evolutionary history of communities. Instead, a more holistic approach that combines network approaches with traditional phylogenetic and biogeographic reconstructions is needed.
Serelaxin in addition to standard therapy in acute heart failure: rationale and design of the RELAX‐AHF‐2 study
Authors: Teerlink John R. , Voors Adriaan A. , Ponikowski Piotr , Pang Peter S. , Greenberg Barry H. , Filippatos Gerasimos , Felker G. Michael , Davison Beth A. , Cotter Gad , Gimpelewicz Claudio , Boer‐Martins Leandro , Wernsing Margaret , Hua Tsushung A. , Severin Thomas , Metra Marco 
Published: April 2017

AbstractPatients admitted for acute heart failure (AHF) experience high rates of in‐hospital and post‐discharge morbidity and mortality despite current therapies. Serelaxin is recombinant human relaxin‐2, a hormone with vasodilatory and end‐organ protective effects believed to play a central role in the cardiovascular and renal adaptations of human pregnancy. In the phase 3 RELAX‐AHF trial, serelaxin met its primary endpoint of improving dyspnoea through day 5 in patients admitted for AHF. Compared to placebo, serelaxin also reduced worsening heart failure (WHF) by 47% through day 5 and both all‐cause and cardiovascular mortality by 37% through day 180. RELAX‐AHF‐2 (
ClinicalTrials.gov NCT01870778) is designed to confirm serelaxin's effect on these clinical outcomes. RELAX‐AHF‐2 is a multicentre, randomized, double‐blind, placebo‐controlled, event‐driven, phase 3 trial enrolling ∼6800 patients hospitalized for AHF with dyspnoea, congestion on chest radiograph, increased natriuretic peptide levels, mild‐to‐moderate renal insufficiency, and systolic blood pressure ≥125 mmHg. Patients are randomized within 16 h of presentation to 48 h intravenous infusions of serelaxin (30 µg/kg/day) or placebo, both in addition to standard of care treatments. The primary objectives are to demonstrate that serelaxin is superior to placebo in reducing: (i) 180 day cardiovascular death, and (ii) occurrence of WHF through day 5. Key secondary endpoints include 180 day all‐cause mortality, composite of 180 day combined cardiovascular mortality or heart failure/renal failure rehospitalization, and in‐hospital length of stay during index AHF. The results from RELAX‐AHF‐2 will provide data on the potential beneficial effect of serelaxin on cardiovascular mortality and WHF in selected patients with AHF.
Topographic forcing of tidal sandbar patterns for irregular estuary planforms
Authors: Leuven J. R. F. W. , de Haas T. , Braat L. , Kleinhans M. G. 
Published: April 2017

AbstractEstuaries typically show converging planforms from the sea into the land. Nevertheless, their planform is rarely perfectly exponential and often shows curvature and the presence of embayments. Here we test the degree to which the shapes and dimensions of tidal sandbars depend on estuary planform. We assembled a dataset with 35 estuary planforms and properties of 190 tidal bars to induce broad‐brush but significant empirical relations between channel planform, hydraulic geometry and bar pattern, and tested a linear stability theory for bar pattern. We found that the location where bars form is largely controlled by the excess width of a channel, which is calculated as the observed channel width minus the width of an ideal exponentially widening estuary. In general, the summed width of bars approximates the excess width as measured in the along‐channel variation of three estuaries for which bathymetry was available as well as for the local measurements in the 35 investigated estuaries. Bar dimensions can be predicted by either the channel width or the tidal prism, because channel width also strongly depends on local tidal prism. Also braiding index was predicted within a factor of 2 from excess width divided by the predicted bar width. Our results imply that estuary planform shape, including mudflats and saltmarsh as well as bar pattern, depend on inherited Holocene topography and lithology and that eventually convergent channels will form if sufficient sediment is available. Copyright © 2017 John Wiley & Sons, Ltd.
Analyzing the capacity of the Daphnia magna and Pseudokirchneriella subcapitata bioavailability models to predict chronic zinc toxicity at high pH and low calcium concentrations and formulation of a generalized bioavailability model for D. magna
Authors: Van Regenmortel Tina , Berteloot Olivier , Janssen Colin R. , De Schamphelaere Karel A. C. 
Published: April 2017

Abstract

Risk assessment in the European Union implements Zn bioavailability models to derive predicted-no-effect concentrations for Zn. These models are validated within certain boundaries (i.e., pH ≤ 8 and Ca concentrations ≥ 5mg/L), but a substantial fraction of the European surface waters falls outside these boundaries. Therefore, we evaluated whether the chronic Zn biotic ligand model (BLM) for Daphnia magna and the chronic bioavailability model for Pseudokirchneriella subcapitata could be extrapolated to pH &gt; 8 and Ca concentrations &lt; 5 mg/L. Results from D. magna experiments suggested that the BLM is not able to reflect the pH effect over a broad pH range (5.5–8.5). In addition, because of Ca deficiency of D. magna in the soft water tests, we cannot conclude whether the BLM is applicable below its Ca boundary. Results for P. subcapitata experiments showed that the bioavailability model can accurately predict Zn toxicity for Ca concentrations down to 0.8 mg/L and pH values up to 8.5. Because the chronic Zn BLM for D. magna could not be extrapolated beyond its validity boundaries for pH, a generalized bioavailability model (gBAM) was developed. Of 4 gBAMs developed, we recommend the use of gBAM-D, which combines a log-linear relation between the 21-d median effective concentrations (expressed as free Zn2+ ion activity) and pH, with more conventional BLM-type competition constants for Na, Ca, and Mg. This model is a first step in further improving the accuracy of chronic toxicity predictions of Zn as a function of water chemistry, which can decrease the uncertainty in implementing the bioavailability-based predicted-no-effect concentration in the risk assessment of high-pH and low–Ca concentration regions in Europe. Environ Toxicol Chem 2017;36:2781–2798. © 2017 SETAC