bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Coke‐Resistant Ni Nanoparticle Catalysts with Minimal Sintering in Dry Reforming of Methane
Authors: Han Joung Woo , Kim Chanyeon , Park Jun Seong , Lee Hyunjoo 
Published: January 2014

AbstractNickel catalysts are typically used for hydrogen production by reforming reactions. Reforming methane with carbon dioxide, called dry reforming of methane (DRM), is a good way to produce hydrogen or syngas (a mixture of hydrogen and carbon monoxide) from two notable greenhouse gases. However, Ni catalysts used for DRM suffer from severe coke deposition. It has been known that small Ni nanoparticles are advantageous to reduce coke formation, but the high reaction temperature of DRM (800 °C) inevitably induces aggregation of the nanoparticles, leading to severe coke formation and degraded activity. Here, we develop highly coke‐resistant Ni catalysts by immobilizing premade Ni nanoparticles of 5.2 nm in size onto functionalized silica supports, and then coating the Ni/SiO2 catalyst with silica overlayers. The silica overlayers enable the transfer of reactants and products while preventing aggregation of the Ni nanoparticles. The silica‐coated Ni catalysts operate stably for 170 h without any degradation in activity. No carbon deposition was observed by temperature programmed oxidation (TPO), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and Raman spectroscopy. The Ni catalysts without silica coating show severe sintering after DRM reaction, and the formation of filamentous carbon was observed. The coke‐resistant Ni catalyst is potentially useful in various hydrocarbon transformations.
Optimized Synthesis and Antimalarial Activity of 1,2‐Dioxane‐4‐carboxamides
Authors: Lombardo Marco , Sonawane Dhiraj P. , Quintavalla Arianna , Trombini Claudio , Dhavale Dilip D. , Taramelli Donatella , Corbett Yolanda , Rondinelli Francesca , Fattorusso Caterina , Persico Marco , Taglialatela‐Scafati Orazio 
Published: January 2014

AbstractWe recently proposed 3‐methoxy‐4‐methoxycarbonyl‐1,2‐dioxanes 3 as promising scaffolds enabling access to potential antimalarial drugs. We present here an optimized two‐step synthesis of 3 characterized by high yields, simple work‐up procedures and high diastereoselectivity allowing us to readily prepare 3 on multigram scale. The versatility of the 1,2‐dioxane scaffold was demonstrated by our generation of a new family of 1,2‐dioxane‐4‐carboxamides 8a–h and the realization of their in vitro activities against chloroquine‐sensitive (D10) and chloroquine‐resistant (W2) P. falciparum strains. In particular, one of these amides (8e), displayed antimalarial activity on par with the natural product lead plakortin and was 5‐fold more active than its methyl ester analogue 3. Structure–activity relationship (SAR) analysis supported by DFT calculations revealed that, for this family of compounds, alkyl substituents at C6 dictate, in large part, the degree of antimalarial activity. This finding contrasts those previously observed for the ester series.
Molecular Design Exploiting a Fluorine gauche Effect as a Stereoelectronic Trigger
Authors: Rey Yannick P. , Zimmer Lucie E. , Sparr Christof , Tanzer Eva‐Maria , Schweizer W. Bernd , Senn Hans Martin , Lakhdar Sami , Gilmour Ryan 
Published: January 2014

AbstractAcyclic conformational control often relies on destabilising noncovalent interactions to give rise to predictable conformer populations. Pertinent examples of such strategies include allylic strain (A1,2 and A1,3) and syn‐pentane interactions. However, the incorporation of fluorine vicinal to an electron‐withdrawing group (F–Cβ–Cα–X) can lead to predictable conformations as a consequence of stabilising hyperconjugative and/or electrostatic interactions. Herein, we describe the application of a fluorine gauche effect to predictably control torsional rotation in a class of fluorinated 4‐(dimethylamino)pyridine (DMAP) analogues. Intramolecularisation, such as protonation or acylation, generates an electropositive nitrogen centre vicinal to the fluorine atom at a molecular hinge (F–Cβ–Cα–N+); this is the only rotatable sp3–sp3 bond. In so doing, this “substrate binding” triggers a conformational change akin to the induced fit process inherent to enzymatic systems. Herein, we validate this design approach to control molecular space. A number of X‐ray structures are documented that display this gauche preference (φNCCF ≈ 60°). Preliminary catalysis experiments are disclosed together with a kinetic and reactivity analysis.
A finite strain closed‐form solution for the elastoplastic ground response curve in tunnelling
Authors: Vrakas Apostolos , Anagnostou Georgios 
Published: January 2014

SUMMARYThe ground response to tunnel excavation is usually described in terms of the characteristic line of the ground (also called ‘ground response curve’, GRC), which relates the support pressure to the displacement of the tunnel wall. Under heavily squeezing conditions, very large convergences may take place, sometimes exceeding 10–20% of the excavated tunnel radius, whereas most of the existing formulations for the GRC are based on the infinitesimal deformation theory. This paper presents an exact closed‐form analytical solution for the ground response around cylindrical and spherical openings unloaded from isotropic and uniform stress states, incorporating finite deformations and linearly elastic‐perfectly plastic rock behaviour obeying the Mohr–Coulomb failure criterion with a non‐associated flow rule. Additionally, the influence of out‐of‐plane stress in the case of cylindrical cavities under plane‐strain conditions is examined. The solution is presented in the form of dimensionless design charts covering the practically relevant parameter range. Finally, an application example is included with reference to a section of the Gotthard Base tunnel crossing heavily squeezing ground. The expressions derived can be used for preliminary convergence assessments and as valuable benchmarks for finite strain numerical analyses. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis and characterization of novel pH‐sensitive chitosan‐poly(acrylamide‐co‐itaconic acid) hydrogels
Authors: Bocourt Michel , Bada Nancy , Acosta Niuris , Bucio Emilio , Peniche Carlos 
Published: January 2014

AbstractNovel pH‐sensitive chitosan‐poly(acrylamide‐co‐itaconic acid) hydrogels were prepared by free radical copolymerization of acrylamide and itaconic acid (IA) in chitosan solution. The hydrogels were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and the swelling ratios of the hydrogels in water (pH 6.8) and pH 1.2. The influence of composition on the thermal properties of the hydrogels was assessed. The glass transition temperatures of the samples increased with IA content, ranging from 110 to 136 °C. Swelling of the hydrogels was found to obey second‐order kinetics with respect to the remnant swelling, indicating that diffusion is controlled by the relaxation of chains. The equilibrium swelling degree was strongly dependent on pH and composition. At both pH values the highest water uptake was obtained for the IA‐free sample M1. From the equilibrium swelling results the average molar mass between crosslinks, Mc, and the crosslink density of the chitosan‐poly(acrylamide‐co‐itaconic acid) samples were calculated. The results evidenced the reinforcing effect of IA on the hydrogel structure. It is concluded that these highly swellable pH‐sensitive hydrogels can be useful for applications in biomedicine and pharmacy. © 2013 Society of Chemical Industry
Using Systemability Function for Periodic Replacement Policy in Real Environments
Authors: Sgarbossa Fabio , Persona Alessandro , Pham Hoang 
Published: January 2014

In the last decades, various maintenance policies have been developed and widely used, including, but not limited to replacement policy and preventive maintenance policy, depending on an accurate estimation of the reliability and the failure intensity functions. Many studies, yet, haven't considered the environmental factors (EFs) and their effects on the survival distribution of operating units. This paper is a following up with our recent research about environmental impacts on preventive maintenance by investigating the periodic replacement policy using a systemability approach. The differences between the classical maintenance approach and the systemability approach have been investigated and applied to a real industrial setting to evaluate the importance and the relevance of taking into account EFs in the implementation of one maintenance policy versus another. Copyright © 2014 John Wiley & Sons, Ltd.HighlightsThis research investigates the impacts of different operational environments in periodic replacement policy, using a new concept called systemability.New mathematical formulations for periodic replacement policy have been introduced and applied to real case studies.Comparison between classical approach and new approach allows to validate the use of systemability and to quantify the impact of operational conditions on total cost.
Recent findings on erasure codes for space communications
Authors: Garrammone Giuliano , De Cola Tomaso , Matuz Balázs , Liva Gianluigi 
Published: January 2014

SUMMARYImplementation of automatic repeat request strategies is the main reliability option available in the Consultative Committee for Space Data Systems protocols to support data communications in deep‐space missions. The large latency often experienced in such scenarios, however, penalizes the efficiency of retransmissions, making the overall applicability of automatic repeat request problematic. On the contrary, the use of erasure codes is a more appealing solution to mitigate packet losses. In this regard, preliminary studies on the use of binary low‐density parity‐check codes under maximum likelihood/iterative decoding have already shown the performance benefit they can bring with respect to traditional schemes based on retransmissions. This paper extends the analysis conducted in previous studies toward non‐binary low‐density parity‐check codes. Performance assessment is carried out with respect to reliability metrics (codeword error rate) and encoding/decoding complexity. Finally, the integration of erasure codes into the Consultative Committee for Space Data Systems protocol stack is discussed, by presenting the implementation in the Licklider Transmission Protocol. Copyright © 2014 John Wiley & Sons, Ltd.
Least angle regression for model selection
Authors: Zhang Hongyang , Zamar Ruben H. 
Published: January 2014

Model selection using least angle regression (LARS) is an interesting approach proposed by Efron B, Hastie T, Johnstone L, Tibshirani R. Least angle regression.The Annals of statistics2004, 320:407–499. In this paper we first review theLARSalgorithm and its relationships with other popular methods such as stagewise regression and the lasso. Then we conduct a survey of recent developments and extensions ofLARS.WIREs Comput Stat2014, 6:116–123. doi: 10.1002/wics.1288This article is categorized under:Statistical Learning and Exploratory Methods of the Data Sciences > Modeling MethodsStatistical Models > Model SelectionStatistical and Graphical Methods of Data Analysis > Modeling Methods and AlgorithmsStatistical Models > Linear Models
eIF5A and EF‐P: two unique translation factors are now traveling the same road
Authors: Rossi Danuza , Kuroshu Reginaldo , Zanelli Cleslei Fernando , Valentini Sandro Roberto 
Published: January 2014

Translational control is extremely important in all organisms, and some of its aspects are highly conserved among all primary kingdoms, such as those related to the translation elongation step. The previously classified translation initiation factor 5A (eIF5A) and its bacterial homologue elongation factor P (EF‐P) were discovered in the late 70's and have recently been the object of many studies. eIF5A and EF‐P are the only cellular proteins that undergo hypusination and lysinylation, respectively, both of which are unique posttranslational modifications. Herein, we review all the important discoveries related to the biochemical and functional characterization of these factors, highlighting the implication of eIF5A in translation elongation instead of initiation. The findings that eIF5A and EF‐P are important for specific cellular processes and play a role in the relief of ribosome stalling caused by specific amino acid sequences, such as those containing prolines reinforce the hypothesis that these factors are involved in specialized translation. Although there are some divergences between these unique factors, recent studies have clarified that they act similarly during protein synthesis. Further studies may reveal their precise mechanism of ribosome activity modulation as well as the mRNA targets that require eIF5A and EF‐P for their proper translation. WIREs RNA 2014, 5:209–222. doi: 10.1002/wrna.1211This article is categorized under:

Translation > Translation Mechanisms
Translation > Translation Regulation
A Systematic Review on the Effectiveness of Tai Chi Exercise in Individuals with Parkinson's Disease from 2003 to 2013*
Authors: Toh Sharon Fong Mei 
Published: January 2014

Objective/Background This study aims to review the current evidence on the effectiveness of Tai Chi exercise in individuals with Parkinson's disease (PD) in the past 10 years. Methods A systematic review of studies published in English from 2003 to 2013, retrieved from three electronic databases—MEDLINE, Cumulative Index to Nursing and Allied Health Literature, and ScienceDirect—was performed. The review selected only those studies that investigated the effects of Tai Chi exercise on individuals with PD and had a full-length publication. Methodological qualities of the randomized control trials were appraised based on the modified Jadad scale. Results Of the 702 articles, eight publications, including four randomized controlled trials, two single-arm intervention studies, and two case reports, were reviewed. Results of this review show that there is an inconsistency of strong empirical evidence to support the efficacy of Tai Chi exercise in the PD population. Furthermore, this review reveals that there is a lack of scientific rigor in the experimental designs of the trials conducted to examine the effects of Tai Chi intervention on the PD population. Conclusion Because of the small sample and inconclusive results, this review cannot provide a firm conclusion to support or refute the effectiveness of Tai Chi in improving motor or nonmotor performance in patients with PD. Further research is required to investigate whether there are specific benefits of Tai Chi for people with PD in these areas and future review should include non-English studies, which examine the use of Tai Chi with this type of population.
Stokes waves in water with a non-flat bed
Authors: Constantin A. 
Published: January 2014

AbstractWe investigate the relevance of Stokes waves for the propagation of ocean swell in the absence of strong currents. By providing estimates for the depth of the near-surface layer to which the main effects of a Stokes flow are confined, we show that wind-generated uniform wave trains can be modelled as Stokes waves over a fictitious flat bed, immersed in the water. Throughout the lower parts of this layer the deviations of the flow from a pure current are negligible.
What Happens Next?: How Ovarian Cancer Forces a Woman into a New Draft of Her Life Script
Authors: Carr Philippa 
Published: January 2014

A diagnosis of ovarian cancer has an impact on many areas of a woman's life which define her identity and life story. Women are forced to reconsider the future ‘scenes’ of their life scripts as they deal with the loss of fertility, a challenge to plans and existential threat. This paper considers this experience within the theoretical framework of the Self-Memory System. Alongside this theory, the author shares her use of dramatherapy tools applied to weekend residential courses run across the UK on four occasions to support women affected by ovarian cancer.
Anticipation by basketball defenders: An explanation based on the three‐dimensional inverted pendulum model
Authors: Fujii Keisuke , Shinya Masahiro , Yamashita Daichi , Kouzaki Motoki , Oda Shingo 
Published: January 2014

AbstractWe previously estimated the timing when ball game defenders detect relevant information through visual input for reacting to an attacker's running direction after a cutting manoeuvre, called cue timing. The purpose of this study was to investigate what specific information is relevant for defenders, and how defenders process this information to decide on their opponents' running direction. In this study, we hypothesised that defenders extract information regarding the position and velocity of the attackers' centre of mass (CoM) and the contact foot. We used a model which simulates the future trajectory of the opponent's CoM based upon an inverted pendulum movement. The hypothesis was tested by comparing observed defender's cue timing, model‐estimated cue timing using the inverted pendulum model (IPM cue timing) and cue timing using only the current CoM position (CoM cue timing). The IPM cue timing was defined as the time when the simulated pendulum falls leftward or rightward given the initial values for position and velocity of the CoM and the contact foot at the time. The model‐estimated IPM cue timing and the empirically observed defender's cue timing were comparable in median value and were significantly correlated, whereas the CoM cue timing was significantly more delayed than the IPM and the defender's cue timings. Based on these results, we discuss the possibility that defenders may be able to anticipate the future direction of an attacker by forwardly simulating inverted pendulum movement.
Colour–magnitude diagrams of transiting Exoplanets – I. Systems with parallaxes
Authors: Triaud Amaury H. M. J. 
Published: January 2014

Abstract
Broad-band flux measurements centred around [3.6 μm] and [4.5 μm] obtained with Spitzer during the occultation of seven extrasolar planets by their host stars have been combined with parallax measurements to compute the absolute magnitudes of these planets. Those measurements are arranged in two colour–magnitude diagrams. Because most of the targets have sizes and temperatures similar to brown dwarfs, they can be compared to one another. In principle, this should permit inferences about exoatmospheres based on knowledge acquired by decades of observations of field brown dwarfs and ultracool stars’ atmospheres. Such diagrams can assemble all measurements gathered so far and will provide help in the preparation of new observational programmes. In most cases, planets and brown dwarfs follow similar sequences. HD 2094589b and GJ 436b are found to be outliers, so is the night side of HD 189733b. The photometric variability associated with the orbital phase of HD 189733b is particularly revealing. The planet exhibits what appears like a spectral type and chemical transition between its day and night sides: HD 189733b straddles the L–T spectral class transition, which would imply different cloud coverage on each hemisphere. Methane absorption could be absent at its hotspot but present over the rest of the planet.
The functions of DNA methylation by CcrM in Caulobacter crescentus: a global approach
Authors: Gonzalez Diego , Kozdon Jennifer B. , McAdams Harley H. , Shapiro Lucy , Collier Justine 
Published: January 2014

Abstract
DNA methylation is involved in a diversity of processes in bacteria, including maintenance of genome integrity and regulation of gene expression. Here, using Caulobacter crescentus as a model, we exploit genome-wide experimental methods to uncover the functions of CcrM, a DNA methyltransferase conserved in most Alphaproteobacteria. Using single molecule sequencing, we provide evidence that most CcrM target motifs (GANTC) switch from a fully methylated to a hemi-methylated state when they are replicated, and back to a fully methylated state at the onset of cell division. We show that DNA methylation by CcrM is not required for the control of the initiation of chromosome replication or for DNA mismatch repair. By contrast, our transcriptome analysis shows that &gt;10% of the genes are misexpressed in cells lacking or constitutively over-expressing CcrM. Strikingly, GANTC methylation is needed for the efficient transcription of dozens of genes that are essential for cell cycle progression, in particular for DNA metabolism and cell division. Many of them are controlled by promoters methylated by CcrM and co-regulated by other global cell cycle regulators, demonstrating an extensive cross talk between DNA methylation and the complex regulatory network that controls the cell cycle of C. crescentus and, presumably, of many other Alphaproteobacteria.
Nitrous Oxide–related Postoperative Nausea and Vomiting Depends on Duration of Exposure
Authors: Peyton Philip J. , Wu Christine Yx 
Published: January 2014

Abstract

Background
Inclusion of nitrous oxide in the gas mixture has been implicated in postoperative nausea and vomiting (PONV) in numerous studies. However, these studies have not examined whether duration of exposure was a significant covariate. This distinction might affect the future place of nitrous oxide in clinical practice.

Methods
PubMed listed journals reporting trials in which patients randomized to a nitrous oxide or nitrous oxide–free anesthetic for surgery were included, where the incidence of PONV within the first 24 postoperative hours and mean duration of anesthesia was reported. Meta-regression of the log risk ratio for PONV with nitrous oxide (lnRR PONVN2O) versus duration was performed.

Results
Twenty-nine studies in 27 articles met the inclusion criteria, randomizing 10,317 patients. There was a significant relationship between lnRR PONVN2O and duration (r

2
= 0.51, P = 0.002). Risk ratio PONV increased 20% per hour of nitrous oxide after 45 min. The number needed to treat to prevent PONV by avoiding nitrous oxide was 128, 23, and 9 where duration was less than 1, 1 to 2, and over 2 h, respectively. The risk ratio for the overall effect of nitrous oxide on PONV was 1.21 (CIs, 1.04–1.40); P = 0.014.

Conclusions
This duration-related effect may be via disturbance of methionine and folate metabolism. No clinically significant effect of nitrous oxide on the risk of PONV exists under an hour of exposure. Nitrous oxide–related PONV should not be seen as an impediment to its use in minor or ambulatory surgery.