bluuebunny/crossref_metadata_2025 huggingface dataset:
Subgroup Variations in Bone Mineral Density Response to Zoledronic Acid After Hip Fracture
Authors: Magaziner Jay S , Orwig Denise L , Lyles Kenneth W , Nordsletten Lars , Boonen Steven , Adachi Jonathan D , Recknor Chris , Colón-Emeric Cathleen S , Mesenbrink Peter , Bucci-Rechtweg Christina , Su Guoqin , Johnson Rasheeda , Pieper Carl F
Published: May 2014

Minimizing post-fracture bone loss is an important aspect of recovery from hip fracture, and determination of factors that affect bone mineral density (BMD) response to treatment after hip fracture may assist in the development of targeted therapeutic interventions. A post hoc analysis of the HORIZON Recurrent Fracture Trial was done to determine the effect of zoledronic acid (ZOL) on total hip (TH) and femoral neck (FN) BMD in subgroups with low-trauma hip fracture. A total of 2127 patients were randomized (1:1) to yearly infusions of ZOL 5 mg (n = 1065) or placebo (n = 1062) within 90 days of operation for low-trauma hip fracture. The 1486 patients with a baseline and at least one post-baseline BMD assessment at TH or FN (ZOL = 745, placebo = 741) were included in the analyses. Percentage change from baseline in TH and FN BMD was assessed at months 12 and 24 and compared across subgroups of hip fracture patients. Percentage change from baseline in TH and FN BMD at months 12 and 24 was greater (p < 0.05) in ZOL-treated patients compared with placebo in most subgroups. Treatment-by-subgroup interactions (p < 0.05) indicated that a greater effect on BMD was observed for TH BMD at month 12 in females, in patients in the lower tertile body mass index at baseline (≤22.6 kg/m2), and in patients with baseline FN BMD T-score of ≤ –2.5; for FN BMD in patients who received ZOL for >6 weeks post-surgery; and for TH and FN BMD in patients with a history of one or more prior fractures. All interactions were limited to the first 12 months after treatment with none observed for the 24-month comparisons. (Clinical trial registration number NCT00046254.) © 2014 American Society for Bone and Mineral Research.
Efficient parameterization of torsional terms for force fields
Authors: Burger Steven K. , Ayers Paul W. , Schofield Jeremy
Published: May 2014

A novel method is presented for fitting force‐field dihedral angles using an ensemble of structures generated from an ab initio Monte Carlo simulation. Importance sampling is used to achieve an efficient algorithm using a low level of theory to minimize the system at each step with the dihedral angles constrained, followed by dihedral fitting using the single point energies at a higher level of theory. The resulting method is an order of magnitude more efficient than the traditional method of doing a constrained scan over each dihedral independently. Also as the sampling is more uniformly distributed, the full surface is approximated to a greater accuracy. The dihedral fitting is done with a nonlinear optimization method to vary the phase as well as the force constant. The utility of the method is demonstrated by fitting dihedrals of methyl L‐lactate, diisopropyl fluorophosphate, isopentenyl phosphate, a leucine dipeptide, and two inhibitors of Signal Transducer and Activator of Transcription 5. The results show that the Monte Carlo scheme is more efficient than constrained scans and is particularly effective at approximating the underlying potential energy surface when the dihedral degrees are coupled. © 2014 Wiley Periodicals, Inc.
In situNIR spectroscopy monitoring of plasmid production processes: effect of producing strain, medium composition and the cultivation strategy
Authors: Lopes Marta B. , Gonçalves Geisa A. L. , Felício‐Silva Daniel , Prather Kristala L. J. , Monteiro Gabriel A. , Prazeres Duarte M. F. , Calado Cecília R. C.
Published: May 2014

BACKGROUND

While the pharmaceutical industry keeps an eye on plasmid DNA production for new generation gene therapies, real‐time monitoring techniques for plasmid bioproduction are as yet unavailable. This work shows the possibility of in situ monitoring of plasmid production in Escherichia coli cultures using a near infrared (NIR) fiber optic probe.

RESULTS

Partial least squares (PLS) regression models based on the NIR spectra were developed for predicting bioprocess critical variables such as the concentrations of biomass, plasmid, carbon sources (glucose and glycerol) and acetate. In order to achieve robust models able to predict the performance of plasmid production processes, independently of the composition of the cultivation medium, cultivation strategy (batch versus fed‐batch) and E. coli strain used, three strategies were adopted, using: (i) E. coli DH5α cultures conducted under different media compositions and culture strategies (batch and fed‐batch); (ii) engineered E. coli strains, MG1655ΔendAΔrecAΔpgi and MG1655ΔendAΔrecA, grown on the same medium and culture strategy; (iii) diverse E. coli strains, over batch and fed‐batch cultivations and using different media compositions. PLS models showed high accuracy for predicting all variables in the three groups of cultures.

CONCLUSION

NIR spectroscopy combined with PLS modeling provides a fast, inexpensive and contamination‐free technique to accurately monitoring plasmid bioprocesses in real time, independently of the medium composition, cultivation strategy and the E. coli strain used. © 2014 Society of Chemical Industry
Iron ochre – a pre‐catalyst for the cracking of methane
Authors: Alharthi Abdulrahman , Blackley Ross A. , Flowers T. Hugh , Hargreaves Justin S. J. , Pulford Ian D. , Wigzell James , Zhou Wuzong
Published: May 2014

BACKGROUND

Iron ochres are gelatinous sludges that can cause problems in terms of water management. In this work, the application of iron ochre obtained from a river has been applied to catalytically crack methane – another potential waste product – into two useful products, hydrogen and a magnetic carbon‐containing composite.

RESULTS

The powder X‐ray diffraction (XRD) pattern of the iron ochre was found to be consistent with the expected 2‐line ferrihydrite, and energy dispersive X‐ray (EDX) analysis showed Fe to be a major component although some Si and Ca were present. The sample was observed to contain a fraction with a tubular morphology consistent with the presence of extra‐cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transform into an active catalyst for hydrogen production yielding a magnetic carbon‐containing composite material comprising filamentous carbon and encapsulating graphite.

CONCLUSION

The application of two waste products – iron ochre and methane – to generate two useful products – hydrogen and a magnetic carbon‐containing composite – has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra‐cellular biogenic iron oxide which may be of interest in terms of other applications. © 2014 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Selection of climate information for regional climate change assessments using regionalization techniques: an example for the Upper Great Lakes Region, USA
Authors: Perdinan  , Winkler Julie A.
Published: May 2014

Climate change assessments often utilize only a small number of climate stations within the assessment region. Consequently, the selection of representative stations that capture the spatial variability of climate is an essential first step of the assessment. Furthermore, climate observations and scenarios frequently need to be linked with other (e.g. agricultural, biological, socioeconomic) datasets available at varying spatial resolutions in order to assess regional‐scale impacts and vulnerability. This study illustrates the utility of well‐known objective climate classification techniques in facilitating regional‐scale climate change assessments, using the Upper Great Lakes region (UGLR) of the United States as an example. A combination of principal components analysis and cluster analysis was employed to group climate stations from the US Historical Climatology Network into a small number of climate regions. The regionalization initially was performed on long‐term averages of monthly maximum and minimum temperatures and precipitation for 1971–2000, and then applied to two earlier time periods (1911–1940 and 1941–1970) to assess the sensitivity of the regionalization to the development period. The spatial variability of average monthly temperature and precipitation in the UGLR was found to be effectively represented by seven climate types. Potential applications of the regionalization for climate change assessments are illustrated. First, Euclidean distance, employed within a geographic information system (ArcGIS), provided a convenient means of assigning political units (counties) within the UGLR to the climate regions to facilitate the integration of point‐scale climate information with spatially‐aggregated datasets. Second, a minimum number of climate stations for an assessment were selected based on the climate regionalization. Finally, the regionalization was used to evaluate the spatial representativeness of a subset of climate stations that were initially chosen based on the completeness of daily observations.
Mental Health Beliefs and Their Relationship With Treatment Seeking Among U.S. OEF/OIF Veterans
Authors: Vogt Dawne , Fox Annie B. , Di Leone Brooke A. L.
Published: May 2014

Many veterans who would benefit from mental health care do not seek treatment. The current study provided an in‐depth examination of mental health‐related beliefs and their relationship with mental health and substance abuse service use in a national sample of 640 U.S. Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) veterans. Both concerns about mental health stigma from others and personal beliefs about mental illness and mental health treatment were examined. Data were weighted to adjust for oversampling of women and nonresponse bias. Results revealed substantial variation in the nature of OEF/OIF veterans’ mental health beliefs, with greater anticipated stigma in the workplace (M = 23.74) than from loved ones (M = 19.30), and stronger endorsement of negative beliefs related to mental health treatment‐seeking (M = 21.78) than either mental illness (M = 18.56) or mental health treatment (M = 20.34). As expected, individuals with probable mental health problems reported more negative mental health‐related beliefs than those without these conditions. Scales addressing negative personal beliefs were related to lower likelihood of seeking care (ORs = 0.80–0.93), whereas scales addressing anticipated stigma were not associated with service use. Findings can be applied to address factors that impede treatment seeking.
What is the Role of Knowledge Management in Establishing the Effectiveness of Public Welfare Services?
Authors: Laihonen Harri , Sillanpää Virpi
Published: May 2014

Because of the increasing cooperation of actors in public service systems, the evaluation of service outcomes involves a complex set of information sources and processes. Organization‐specific evaluation practices yield only a partial picture of the effectiveness of services. To address this issue, the paper studies the information processes in the context of Finnish social services and analyzes knowledge‐related problems in system‐level performance measurement. As a result, this paper proposes that more systematic knowledge management is needed in order to provide valid information on the effectiveness of public welfare services. The findings contribute to the study, analysis, and implementation of knowledge management in the public domain. We further provide a discussion relating to the challenges in measuring service effectiveness of information processes with respect to gathering, combining, and presenting performance information. This research adds to the literature by presenting a system‐level analysis of information flows and pinpointing the most crucial disconnects with respect to these flows. The results that we present have clear implications for strategic and political decision‐making. Copyright © 2014 John Wiley & Sons, Ltd.
Diode laser‐induced tissue effects: In vitro tissue model study and in vivo evaluation of wound healing following non‐contact application
Authors: Havel Miriam , Betz Christian S. , Leunig Andreas , Sroka Ronald
Published: May 2014

Introduction

The basic difference between the various common medical laser systems is the wavelength of the emitted light, leading to altered light–tissue interactions due to the optical parameters of the tissue. This study examines laser induced tissue effects in an in vitro tissue model using 1,470 nm diode laser compared to our standard practice for endonasal applications (940 nm diode laser) under standardised and reproducible conditions. Additionally, in vivo induced tissue effects following non‐contact application with focus on mucosal healing were investigated in a controlled intra‐individual design in patients treated for hypertrophy of nasal turbinate.

Methods

A certified diode laser system emitting the light of λ = 1470 nm was evaluated with regards to its tissue effects (ablation, coagulation) in an in vitro setup on porcine liver and turkey muscle tissue model. To achieve comparable macroscopic tissue effects the laser fibres (600 µm core diameter) were fixed to a computer controlled stepper motor and the laser light was applied in a reproducible procedure under constant conditions.

For the in vivo evaluation, 20 patients with nasal obstruction due to hyperplasia of inferior nasal turbinates were included in this prospective randomised double‐blinded comparative trial. The endoscopic controlled endonasal application of λ = 1470 nm on the one and λ = 940 nm on the other side, both in ‘non‐contact’ mode, was carried out as an outpatient procedure under local anaesthesia. The postoperative wound healing process (mucosal swelling, scab formation, bleeding, infection) was endoscopically documented and assessed by an independent physician.

Results

In the experimental setup, the 1,470 nm laser diode system proved to be efficient in inducing tissue effects in non‐contact mode with a reduced energy factor of 5–10 for highly perfused liver tissue to 10–20 for muscle tissue as compared to the 940 nm diode laser system.

In the in vivo evaluation scab formation following laser surgery as assessed clinically on endonasal endoscopy was significantly reduced on 1,470 nm treated site compared to 940 nm diode laser treated site.

Conclusions

Diode laser system (1,470 nm) induces efficient tissue effects compared to 940 nm diode laser system as shown in the tissue model experiment. From the clinical point of view, the healing process following non‐contact diode laser application revealed to be improved using 1,470 nm diode laser compared to our standard diode laser practise with 940 nm. Lasers Surg. Med. 46:449–455, 2014. © 2014 Wiley Periodicals, Inc.
Silicone Rubber Modified with Methacrylic Acid to Host Antiseptic Drugs
Authors: Vázquez‐González Brenda , Meléndez‐Ortiz H. Iván , Díaz‐Gómez Luis , Alvarez‐Lorenzo Carmen , Concheiro Angel , Bucio Emilio
Published: May 2014

Silicone rubber (SR) was γ‐ray grafted with poly(methacrylic acid) (PMAA) to improve its ability to host antimicrobial drugs. Dependence of grafting yield on monomer concentration, pre‐irradiation dose, temperature and reaction time was evaluated. Modified SR films were characterized by means of FT‐IR, DSC, TGA, SEM, contact angle measurements, and swelling studies. SR‐g‐MAA showed pH sensitivity (critical pH ∼6) and good cytocompatibility. Soaking of SR‐g‐MAA in benzalkonium chloride and vancomycin aqueous solutions led to high loadings; up to 5.8 and 15.2 mg cm‐2, respectively. SR‐g‐MAA released 100% vancomycin after 24 h in buffer pH 7.4 at 37 °C, but only 20% benzalkonium chloride due to strong ionic interactions. Drug‐loaded SR‐g‐MAA prevented in vitro growth of Staphylococcus aureus. Overall, grafting of PMAA may improve the performance of SR for biomedical applications.
Evaluating Modified Tannin Esters as Functional Additives in Polypropylene and Biodegradable Aliphatic Polyester
Authors: Grigsby Warren J. , Bridson James H. , Lomas Cole , Frey Helena
Published: May 2014

Esterified and native condensed tannins have been evaluated in polypropylene and the aliphatic polyester Bionolle. Tannin esters at typical plastic additive loadings have minimal effect on plastic mechanical properties. In assessing functional equivalence tannin esters inhibit the effects of UV degradation in both polypropylene and Bionolle with tannin hexanoate acetate having greater efficacy than a synthetic UV stabiliser at comparable loading. Oxidative induction testing also suggests the tannin esters can act to prevent oxidative degradation of polypropylene. However, retention of antioxidant capacity was crucial to inhibiting oxidative degradation. Outcomes suggest bio‐based tannin additives have potential to substitute synthetic additives and improve plastic sustainability credentials.
UV Cured Polymeric Optical Fluorescence Sensor for the Determination of Au (III)
Authors: Çubuk Soner , Yetimoğlu Ece Kök , Kahraman M. Vezir , Kenan Sibel
Published: May 2014

The recognition and sensing of the biologically and environmentally important metal ions has emerged as a significant goal in the field of chemical sensors in recent years. Among the various analytical methods, fluorescence has been a powerful tool due to its simplicity, high detection limit and application to bio imaging.

In this study, UV cured polymeric optical sensor for Au (III) ion based on a fluorescence membrane has been developed. The response characteristics of the sensor including dynamic range, pH effect and response time were systematically investigated. The influences of the conditions such as pH, response time on the metal ion binding capacity of membrane were also tested.
A Near‐Infrared Spectroscopy Study on Thermal Transitions of PMMA and PMMA/SiO2 Nanocomposites
Authors: Sanchez Freddy A. , Redondo Marta , Olmos Dania , Kuzmanovic Maja , González‐Benito Javier
Published: May 2014

In this work infrared spectroscopy in the near infrared (NIR) range is used to study the dynamics of polymethylmethacrylate (PMMA) as a pure polymer and when it is modified with silica nanoparticles. Different ways of analyzing FT‐NIR spectra were explored taking the temperature as the variable of the systems: i) bands shifts in terms of the first moment of the wavenumber; ii) bands shifts in terms of an absorbance ratio method and iii) absorbance variations in terms of the integrated absorbance. The spectroscopic analysis allowed to study thermal transitions in PMMA and PMMA based nanocomposites. In particular the method based on the use of an absorbance ratio is the most sensible to analyze the thermal transitions. All bands considered could be used to detect thermal transitions reflecting how the vibrations of the groups CH2; CH3 and CO are affected by changes in the free volume of the PMMA. It seems that the PMMA dynamics is more driven by the lateral groups than the backbone of the polymer. The presence of silica nanoparticles, at least when 1% by weight is used, restrains the PMMA motion increasing the relaxation temperatures that can be associated with the glass transitions.
Slow and Very Fast MAS Solid State NMR Study of Biopolymers
Authors: Pawlak Tomasz , Paluch Piotr , Jeziorna Agata , Bujacz Grzegorz D. , Potrzebowski Marek J.
Published: May 2014

In the first part of article, the “NMR Crystallography” approach as tool to fine refinement of solid state structure of biopolymers is presented, employing the α polymorph of L‐polylactide (PLLA) as model. Slow Magic Angle Spinning (MAS) technique (with spinning rate of sample in range from 1.2 kHz to 8.0 kHz) was used to assign 13C isotropic chemical shifts and values of 13C δii principal elements of chemical shifts tensors (CST). Theoretical 13C shielding parameters σii were obtained employing GIPAW (Gauge Invariant Projector Augmented Wave) method and compared with experimental 13C δii elements. The computed and experimental 13C CP/MAS spectra for WAND (Wide Angle Neutron Diffraction) geometry of powdered α PLLA were evaluated. It was revealed that the computed model of α PLLA model better fit to experimental NMR spectra.

In the second part of article the applications of the new NMR methodology, so called very fast MAS (VF MAS) with sample spinning over 60 kHz are presented. The power of this approach is shown employing the 13C and 15N labeled protein, ubiquitin. We revealed that Cross‐Polarization with Variable Contact (CPVC) time sequence under very‐fast MAS condition performed in two‐dimensional (2D) mode is very efficient method to measure accurately the CH and NH distances, and to analyze the dynamics of proteins with overlapped resonances in aliphatic and aromatic regions.
Using Soft Potentials for the Simulation of Block Copolymer Morphologies
Authors: Parker Amanda J. , Rottler Jörg
Published: May 2014

A simulation strategy for the creation of equilibrated nanostructured copolymer melt morphologies is proposed. Molecular dynamics simulations of bead‐spring chains with a soft pair potential are used for efficient modeling of phase separation, while preserving Gaussian chain statistics and chain conformations of an underlying microscopic model. In a second step, hard excluded volume interactions are reintroduced that match the copolymer segregation strength but only require reequilibration of local packing structure. We show that substantial computational gains can be achieved for equilibrating moderately entangled bead‐spring polymers. The resultant configurations can be used for further studies of structural and mechanical properties in melts or glasses.
Increased impulsivity in response to food cues after sleep loss in healthy young men
Authors: Cedernaes Jonathan , Brandell Jon , Ros Olof , Broman Jan‐Erik , Hogenkamp Pleunie S. , Schiöth Helgi B. , Benedict Christian
Published: May 2014

Objective

To investigate whether acute total sleep deprivation (TSD) leads to decreased cognitive control when food cues are presented during a task requiring active attention, by assessing the ability to cognitively inhibit prepotent responses.

Methods

Fourteen males participated in the study on two separate occasions in a randomized, crossover within‐subject design: one night of TSD versus normal sleep (8.5 hours). Following each nighttime intervention, hunger ratings and morning fasting plasma glucose concentrations were assessed before performing a go/no‐go task.

Results

Following TSD, participants made significantly more commission errors when they were presented “no‐go” food words in the go/no‐go task, as compared with their performance following sleep (+56%; P<0.05). In contrast, response time and omission errors to “go” non‐food words did not differ between the conditions. Self‐reported hunger after TSD was increased without changes in fasting plasma glucose. The increase in hunger did not correlate with the TSD‐induced commission errors.

Conclusions

Our results suggest that TSD impairs cognitive control also in response to food stimuli in healthy young men. Whether such loss of inhibition or impulsiveness is food cue‐specific as seen in obesity—thus providing a mechanism through which sleep disturbances may promote obesity development—warrants further investigation.
Improving anticoagulant prescribing for AF
Authors: Petty Duncan , Fay Matthew
Published: May 2014

Anticoagulants are effective at preventing strokes in AF, but there is concern that GPs are not adequately prescribing them. Here, the authors discuss the barriers to prescribing anticoagulants and
how to increase their use.
Relvar Ellipta: new once‐daily steroid/LABA inhaler
Authors: Chaplin Steve , Thomson Neil C
Published: May 2014

Relvar Ellipta is a new inhaled steroid/long‐acting beta‐agonist combination taken once daily. In our New products review, Steve Chaplin presents the data relating to its efficacy and adverse events, and Professor Neil Thomson discusses its place in therapy.
Diagnosis and recommended treatment of helminth infections
Authors: Abbas Allifia , Wade Paul , Newsholme William
Published: May 2014

A number of worm infections are seen in the UK, often in migrants from tropical countries, and it is essential to take a travel history. Our Drug review discusses the features of the most common infections and details currently recommended treatments.
Implementing value‐based assessment of medicines
Authors: Chaplin Steve
Published: May 2014

Steve Chaplin examines NICE's proposals to introduce two weighting systems into its technology appraisal process in order to better reflect the value of new treatments.
Ensemble post‐processing using member‐by‐member approaches: theoretical aspects
Authors: Van Schaeybroeck Bert , Vannitsem Stéphane
Published: May 2014

Linear post‐processing approaches are proposed and fundamental mechanisms are analyzed by which the probabilistic skill of an ensemble forecast can be improved. The ensemble mean of the corrected forecast is a linear function of the ensemble mean(s) of the predictor(s). Likewise, the ensemble spread of the corrected forecast depends linearly on that of the uncorrected forecast. The regression coefficients are obtained by maximizing the likelihood function for the error distribution. Comparing different calibration approaches on simple systems that exhibit chaotic features (the Kuramoto–Sivashinsky equation, the spatially extended Lorenz system), four correction mechanisms are identified: the ensemble‐mean scaling and nudging using the predictor(s), and the ensemble‐spread scaling and nudging. Ensemble‐spread corrections turn out to yield improvement only when ‘reliability’ constraints are imposed on the corrected forecast. First of all climatological reliability is enforced and is satisfied when the total variability of the forecast is equal to the variability of the observations. Second, ensemble reliability or calibration of the ensembles is enforced such that the squared error of the ensemble mean coincides with the ensemble variance.

In terms of continuous ranked probability skill score, spread calibration provides much more gain in skill than the traditional ensemble‐mean calibration and extends for lead times far beyond the error‐doubling time. The skill performance is better than or as good as the benchmark calibration method which derives from statistical assumptions –non‐homogeneous Gaussian regression. In addition to the member‐by‐member nature of the approach, benefits compared with the benchmark method can be pinpointed. In particular, although the post‐processing methods are performed for each lead time, location and variable independently, they preserve the rank correlations and thus take dependencies across space, time, and different variables into account. In addition, higher‐order ensemble moments like kurtosis and skewness correspond to those of the uncorrected forecasts.
Observation of adhesive force and energy of adsorbents on rubber substrates by atomic force microscopy
Authors: Lee Nuri , Jo W. , Lee B. K. , Jung W. K.
Published: May 2014

We observed the surface morphology and adhesive interaction of adsorbents on rubber substrates by atomic force microscopy (AFM). The detachment of adsorbents from rubber substrates is an important issue for various machines like home appliances and laundry machine. Since a clean surface of the functioning parts is required, a frequent cleaning process must be developed. In particular, dust and lint have a tendency to bind to the rubber surface of a laundry machine. Several practical methods have been attempted to remove these particles from the surface. Pure water, detergent, sodium hypochlorite (65 °C), and cold water (18 °C) are treated onto artificial dust and lint mixtures on rubber with water fluid by rapid rpm. The dust‐and‐lint adsorbents are investigated by AFM after the treatment, and topographic images and force–distance (F–D) curves were generated for the samples. The roughness, measured as the root mean square, is a key factor to judge the cleaning quality. From the F–D curves, we are able to obtain adhesive energy in addition to adhesive force which will yield qualitative measures of the interactions between the remaining adsorbents and the rubber surface. Considering the values that were measured, hot water with water fluid by rapid rpm offers the best performance when cleaning the surface. The chemical like sodium hypochlorite is good for thinning the materials, but it solidifies them, which is eventually detrimental to proper functioning. Copyright © 2014 John Wiley & Sons, Ltd.
Preparation of a Mitochondria‐targeted and NO‐Releasing Nanoplatform and its Enhanced Pro‐Apoptotic Effect on Cancer Cells
Authors: Xu Jiangsheng , Zeng Fang , Wu Hao , Hu Caiping , Yu Changmin , Wu Shuizhu
Published: May 2014

The therapeutic applications of exogenous nitric oxide are usually limited by its short half‐life and its vulnerability to many biological substances, thus straightforward and precise spatiotemporal control of NO delivery may be critical to its therapeutic effects. Herein, the mitochondria‐targeted and photoresponsive NO‐releasing nanosystem is demonstrated as a new approach for cancer treatment. The nanosystem is fabricated by covalently incorporating a NO photo‐donor and a mitochondria targeting ligand onto carbon‐dots; accordingly, multi‐functionalities (mitochondria‐targeting, light‐enhanced efficient NO‐releasing, and cell imaging) are achieved. The in vitro NO release profiles for the nanosystem show that the duration of NO release from the present C‐dot‐based nanosystem containing immobilized SNO can be extended up to 8 hours or more. Upon cellular internalization, the nanosystem can target mitochondria and release NO. The action of the nanosystem on three cancer cell lines is evaluated; it is found that the targeted NO‐releasing system can cause high cytotoxicity towards the cancer cells by specifically damaging their mitochondria. Additionally, light irradiation can amplify the cell apoptosis by enhancing NO release. These observations demonstrate that incorporating mitochondria‐targeting ligand onto a NO‐releasing system can enhance its pro‐apoptosis action, thereby providing new insights for exploiting NO in cancer therapy.
Breeze graph grammar: a graph grammar approach for modeling the software architecture of big data‐oriented software systems
Authors: Li Chen , Huang Linpeng , Chen Luxi
Published: May 2014

Various technologies have been proposed to support the processing of big data. However, such technologies require software architectures not only to adapt to the changes and achieve dynamic evolution but also to be reliable. Most of the architecture description techniques are not able to directly capture the dynamic changes in the definition of the software architecture and cannot analyze or evaluate the system reliability. In this paper, we provide a breeze graph grammar (BGG) to model the software architecture in both static and dynamic aspects and give a BGG reliability model to help supporting software system reliability modeling and evaluation. Our work expands this idea in three directions. We first present the definition of BGG to specify the software architecture and map the system dynamic evolution to BGG transformation rules. Second, a BGG reliability model is proposed in which we add error attributes to the BGG graph for capturing the system error information, and the system error state transition is performed through BGG graph rewriting rules. Then, we study the rules to map the BGG reliability model to a generalized stochastic Petri net (GSPN) model, which can be used for reliability evaluation. Throughout this paper, we use a big data‐based centralized system to demonstrate our approach. The BGG graph rewriting characteristic supports the dynamic change requirements, and the architecture is statically checked through the BGG productions. Moreover, system reliability modeling and evaluation can be achieved through the BGG reliability model by combining GSPN. Copyright © 2014 John Wiley & Sons, Ltd.
Netkit: network emulation for education
Authors: Pizzonia Maurizio , Rimondini Massimo
Published: May 2014

In the era of virtualization, virtual networking plays an important role. Besides production use, virtual networking can be effectively adopted in many other contexts where accurate emulation of functionalities is important, like testing before deployment, evaluation of what‐if scenarios, research, and, increasingly, didactics. In this paper, we describe our 10‐year experience in designing, implementing, using, and maintaining Netkit, an environment for simple, inexpensive, and lightweight network emulation targeted at didactics. We analyze the peculiar requirements in this context and discuss how the architecture chosen for Netkit is tailored to fulfill them. We show that Netkit is particularly well suited for a quick preparation of complex network scenarios comprising a wide range of networking technologies. These scenarios can be specified using configuration languages that are similar to those used on real devices and, once set up, can be easily distributed via email or published on the Web. Netkit comes with a rich set of ready‐to‐use pre‐configured networks, accompanied by lecture slides that enable users to immediately experiment with specific case studies. To complete the picture, we report our experience in supporting and fostering the growth of the community of users revolving around Netkit: more than 15 educational institutions worldwide take advantage of Netkit, allowing teachers and students to practice with realistic networks without the need of expensive laboratories. We also detail how we profitably use Netkit within advanced academic‐level networking courses and related examinations at the Roma Tre University. Copyright © 2014 John Wiley & Sons, Ltd.
Assessment of esophageal motor function using combined multichannel intraluminal impedance and manometry in patients with achalasia
Authors: Lei Wei‐Yi , Lo Wen‐Lin , Yi Chih‐Hsun , Liu Tso‐Tsai , Chen Chien‐Lin
Published: May 2014

Background

Achalasia is characterized by esophageal aperistalsis and a failure of lower esophageal sphincter (LES) relaxation. Combined multichannel intraluminal impedance and manometry (MII‐EM) allows the simultaneous recording of esophageal peristalsis and bolus transport patterns. The aim of this study was to evaluate the feasibility of MII‐EM for the assessment of esophageal motility and to characterize patterns of esophageal bolus transport in patients with achalasia with or without Heller myotomy.

Materials and methods

A total of nine patients (2 men and 7 women, age range 25–46 years) were enrolled in this study. Two of the patients had previously undergone Heller myotomy. All patients underwent combined MII‐EM with a nine‐channel esophageal function testing catheter containing four impedance measuring segments and five solid‐state pressure transducers. Each patient received 10 liquid and 10 viscous swallows in a sitting position. All tracings were recorded and analyzed for esophageal contractions and bolus transit.

Results

None of the patients with achalasia, whether they had undergone a Heller myotomy or not, had manometrically normal esophageal peristalsis during saline or viscous swallowing. They had a normal LES resting pressure, incomplete LES relaxation, and lower distal esophageal contraction. The LES relaxation percentages in the patients who had undergone Heller myotomy (97% and 51%) were higher than those of the untreated patients (mean 47%). All patients demonstrated a low baseline impedance level in the distal esophagus. Air trapping in the proximal esophagus was also detected in nearly all of the patients. None of the patients in either group had complete bolus transit with either saline or viscous swallows.

Conclusion

Patients with achalasia are characterized by poor esophageal contraction and absent esophageal bolus clearance and such abnormalities are still noticeable after Heller myotomy. Although combined MII‐EM can provide additional information regarding esophageal bolus transit, a low baseline impedance level and air trapping in the proximal esophagus may limit its utility in the diagnosis of esophageal dysmotility in patients with achalasia.
Time-analyticity of Lagrangian particle trajectories in ideal fluid flow
Authors: Zheligovsky Vladislav , Frisch Uriel
Published: May 2014

It is known that the Eulerian and Lagrangian structures of fluid flow can be drastically different; for example, ideal fluid flow can have a trivial (static) Eulerian structure, while displaying chaotic streamlines. Here, we show that ideal flow with limited spatial smoothness (an initial vorticity that is just a little better than continuous) nevertheless has time-analytic Lagrangian trajectories before the initial limited smoothness is lost. To prove these results we use a little-known Lagrangian formulation of ideal fluid flow derived by Cauchy in 1815 in a manuscript submitted for a prize of the French Academy. This formulation leads to simple recurrence relations among the time-Taylor coefficients of the Lagrangian map from initial to current fluid particle positions; the coefficients can then be bounded using elementary methods. We first consider various classes of incompressible fluid flow, governed by the Euler equations, and then turn to highly compressible flow, governed by the Euler–Poisson equations, a case of cosmological relevance. The recurrence relations associated with the Lagrangian formulation of these incompressible and compressible problems are so closely related that the proofs of time-analyticity are basically identical.
Mixed acoustic–entropy combustion instabilities in gas turbines
Authors: Motheau Emmanuel , Nicoud Franck , Poinsot Thierry
Published: May 2014

A combustion instability in a combustor terminated by a nozzle is analysed and modelled based on a low-order Helmholtz solver. A large eddy simulation (LES) of the corresponding turbulent, compressible and reacting flow is first performed and analysed based on dynamic mode decomposition (DMD). The mode with the highest amplitude shares the same frequency of oscillation as the experiment (approximately 320 Hz) and shows the presence of large entropy spots generated within the combustion chamber and convected down to the exit nozzle. The lowest purely acoustic mode being in the range 700–750 Hz, it is postulated that the instability observed around 320 Hz stems from a mixed entropy–acoustic mode, where the acoustic generation associated with entropy spots being convected throughout the choked nozzle plays a key role. The DMD analysis allows one to extract from the LES results a low-order model that confirms that the mechanism of the low-frequency combustion instability indeed involves both acoustic and convected entropy waves. The delayed entropy coupled boundary condition (DECBC) (Motheau, Selle & Nicoud, J. Sound Vib., vol. 333, 2014, pp. 246–262) is implemented into a numerical Helmholtz solver where the baseline flow is assumed at rest. When fed with appropriate transfer functions to model the entropy generation and convection from the flame to the exit, the Helmholtz/DECBC solver predicts the presence of an unstable mode around 320 Hz, in agreement with both LES and experiments.
Acoustic invisibility in turbulent fluids by optimised cloaking
Authors: Huang Xun , Zhong Siyang , Liu Xin
Published: May 2014

Acoustic invisibility of a cloaking system in turbulent fluids is poorly understood. Here we show that evident scattering would appear in turbulent wakes due to the submergence of a classical cloaking device. The inherent physical mechanism is explained using our theoretical model, which eventually inspires us to develop an optimised cloaking approach. Both the near- and far-field scattered fields are examined using computational methods. The remarkably low scattering demonstrates the effectiveness of the proposed approach, in particular for acoustic cloaking in turbulent fluids.
Nature and dynamics of overreflection of Alfvén waves in MHD shear flows
Authors: Gogichaishvili D. , Chagelishvili G. , Chanishvili R. , Lominadze J.
Published: May 2014

Our goal is to gain new insights into the physics of wave overreflection phenomenon in magnetohydrodynamic (MHD) nonuniform/shear flows changing the existing trend/approach of the phenomenon study. The performed analysis allows to separate from each other different physical processes, grasp their interplay and, by this way, construct the basic physics of the overreflection in incompressible MHD flows with linear shear of mean velocity, U0=(Sy,0,0), that contain two different types of Alfvén waves. These waves are reduced to pseudo- and shear-Alfvén waves when wavenumber along Z-axis equals zero (i.e. when kz=0). Therefore, for simplicity, we labeled these waves as: P-Alfvén and S-Alfvén waves (P-AWs and S-AWs). We show that: (1) the linear coupling of counter-propagating waves determines the overreflection, (2) counter-propagating P-AWs are coupled with each other, while counter-propagating S-AWs are not coupled with each other, but are asymmetrically coupled with P-AWs; S-AWs do not participate in the linear dynamics of P-AWs, (3) the transient growth of S-AWs is somewhat smaller compared with that of P-AWs, (4) the linear transient processes are highly anisotropic in wave number space, (5) the waves with small streamwise wavenumbers exhibit stronger transient growth and become more balanced, (6) maximal transient growth (and overreflection) of the wave energy occurs in the two-dimensional case – at zero spanwise wavenumber.

To the end, we analyze nonlinear consequences of the described anisotropic linear dynamics – they should lead to an anisotropy of nonlinear cascade processes significantly changing their essence, pointing to a need of revisiting the existing concepts of cascade processes in MHD shear flows.
Effect of dust–dust interaction type on normal modes of two-dimensional dust crystals
Authors: Bekda A. , Djebli M.
Published: May 2014

Dispersion relations for longitudinal and transverse dust lattice waves in two-dimensional hexagonal dust crystals of negatively charged particles were investigated and compared for two different interaction types, namely, Coulomb and screened Yukawa potentials. Results showed that the interaction type and the wave propagation direction change the characteristics of the dispersion relation as well as the group velocity. The screening parameter is also found to reduce the mode frequencies.
Heterobranch sea slugs (Mollusca: Gastropoda) from Ascension Island, South Atlantic Ocean
Authors: Padula Vinicius , Wirtz Peter , Schrödl Michael
Published: May 2014

The small volcanic island of Ascension is situated in the middle of the South Atlantic Ocean, more than 1500 km from the coast of Africa, its nearest continental area. To date, eight ‘opisthobranch’ species were reported from the island. As a result of a recent survey, 10 species were found. Seven species are new records from Ascension:Platydoris angustipes(Mörch, 1863),Diaululasp.,Dolabrifera dolabrifera(Rang, 1828),Aplysia parvulaGuilding in Mörch, 1863and Caliphylla mediterraneaA. Costa, 1867, and two new species:Phidiana mimica sp. nov.; andFelimida atlantica sp. nov. Half of the species found have a wide geographical distribution, being not restricted to the Atlantic Ocean. However, traditional taxonomy based on few characters is probably masking complexes of species.
The United States and China in the Arctic
Authors: Lundestad Ingrid , Tunsjø Øystein
Published: May 2014

US-China relations represent the most central bilateral relationship in the world, but few studies investigate the two countries’ approaches to the Arctic. This article explores the geopolitical shifts in the Arctic, and compares and contrasts American and Chinese policy in the region. The article examines to what extent the two have common or conflicting interests, and discusses the potential for US-China friction and rivalry. Some alarmist writers suggest that the future Arctic is set for confrontation. This article, however, argues that the current stakes in the circumpolar Arctic region are not sufficiently high to warrant confrontation between the two states. Cooperation predominantly guides their policies and activities. While they play different roles and increasingly seek to demonstrate their influence, there are common interests, such as in the freedom of the seas, in resource extraction and in developing infrastructure in the region.
Road Expansion and Off-Farm Work in Rural China
Authors: Qiao Fangbin , Rozelle Scott , Huang Jikun , Zhang Linxiu , Luo Renfu
Published: May 2014

This study estimates the impact of road expansion on off-farm activities in rural China. To achieve this goal, econometric models that capture the impact of road expansion on migration and local off-farm works are developed and estimated using individual data. Estimation results show that road expansion encourages farmers to participate in local off-farm work rather than migrate. In addition, road expansion also has a significant impact on the working time and income of local off-farm work.
Fractional vector-valued Littlewood–Paley–Stein theory for semigroups
Authors: Torrea José L. , Zhang Chao
Published: May 2014

We consider the fractional derivative of a general Poisson semigroup. With this fractional derivative, we define the generalized fractional Littlewood–Paley g-function for semigroups acting on Lp-spaces of functions with values in Banach spaces. We give a characterization of the classes of Banach spaces for which the fractional Littlewood–Paley g-function is bounded on Lp-spaces. We show that the class of Banach spaces is independent of the order of derivation and coincides with the classical (Lusin-type/-cotype) case. We also show that the same kind of results exist for the case of the fractional area function and the fractional gλ*-function on ℝn. Finally, we consider the relationship of the almost sure finiteness of the fractional Littlewood–Paley g-function, the area function and the gλ*-function with the Lusin-cotype property of the underlying Banach space. As a byproduct of the techniques developed, one can find some results of independent interest for vector-valued Calderón–Zygmund operators. For example, one can find the following characterization: a Banach space is the unconditional martingale difference if and only if, for some (or, equivalently, for every) p ∈ [1, ∞), dy exists for almost every x ∈ ℝ and every .
Cellular self-organizing systems: A field-based behavior regulation approach
Authors: Jin Yan , Chen Chang
Published: May 2014

Multiagent systems have been considered as a potential solution for developing adaptive systems. In this research, a cellular self-organizing (CSO) approach is proposed for developing such multiagent adaptive systems. The design of CSO systems however is difficult because the global effect emerges from local actions and interactions that are often hard to specify and control. In order to achieve high-level flexible and robustness of CSO systems and retain the capability of specifying desired global effects, we propose a field-based regulative control mechanism, called field-based behavior regulation (FBR). FBR is a real-time, dynamical, distributed mechanism that regulates the emergence process for CSO systems to self-organize and self-reconfigure in complex operation environments. FBR characterizes the task environment in terms of “fields” and extends the system flexibility and robustness without imposing global control over local cells or agents. This paper describes the model of CSO systems and FBR, and demonstrates their effectiveness through simulation-based case studies.