bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Glycosidase Inhibition Studies of 5‐Methyl‐Substituted Tetrahydroxyindolizidines and ‐pyrrolizidines Related to Natural Hyacinthacines B
Authors: Martella Daniele , Cardona Francesca , Parmeggiani Camilla , Franco Francisco , Tamayo Juan A. , Robina Inmaculada , Moreno‐Clavijo Elena , Moreno‐Vargas Antonio J. , Goti Andrea 
Published: May 2013

AbstractThe synthesis of three tetrahydroxyindolizidines and one tetrahydroxypyrrolizidine related to natural hyacinthacines B and their biological evaluation as glycosidase inhibitors is reported. The target molecules were obtained through highly stereoselective cycloadditions between sugriched allylic and homoallylic alcohols. This allowed the installation of a methyl group at C5 – a common feature of many natural hyacinthacines – with high control over the stereoselectivity. The new compounds inhibit amyloglucosidase from Aspergillus niger and β‐glucosidase from almonds. Compound 1 is a competitive inhibitor of amyloglucosidase and shows a fair selectivity towards this enzyme. The presence of C5‐Me substitution in indolizidines 2 and 3 slightly diminishes the inhibitory activity towards amyloglucosidase whereas it improves the inhibitory properties towards β‐glucosidase.
Urea Assisted Synthesis of Flower Like CuO Nanostructures and Their Chemical Sensing Application for the Determination of Cadmium Ions
Authors: Khun K. , Ibupoto Z. H. , Willander M. 
Published: May 2013

AbstractThe novel nanostructures of CuO with improved morphology are strongly required for the development of devices with enhanced performance. In this study flower like nanostructures of CuO are synthesized by hydrothermal method using urea as tuning material for the morphology of CuO during the growth process. Scanning electron microscopy (SEM) and X‐ray diffraction (XRD) techniques were used for the characterization of these nanostructures. The nanostructures are highly dense, uniform and well aligned on the gold coated glass substrate. Moreover, CuO nanostructures exhibited pure phase of CuO. These novel CuO nanostructures were potentially used for the construction of cadmium ion sensor by functionalizing with tetrathia‐12‐crown‐4 a selective cadmium ion ionophore. The proposed cadmium ion sensor has detected the wide range of cadmium ion concentrations from 1.0×10−9–1.0×10−1 M with a sensitivity of 29.3±0.3 mV/decade and also a fast response time of less than 10.0 s is demonstrated. CuO nanostructures based cadmium ion selective electrode has also shown excellent reproducibility, repeatability, selectivity, and stability. The sensor electrode was also used as indicator electrode for the confirmation of practical utility and the obtained result describes the good behavior of the sensor in the potentiometric titration for the determination of cadmium ions.
From Electrode Surface Fouling to Sensitive Electroanalytical Determination of Phenols
Authors: Kawde Abdel‐Nasser , Morsy Mohamed A. , Odewunmi Nurudeen , Mahfouz Wael 
Published: May 2013

AbstractThe present investigation of phenol and chlorophenols is conducted on the surface of glassy carbon by cyclic and square wave stripping voltammetry, and by Fourier‐transform infrared spectroscopy. The surface fouling is accompanied by the appearance of reversible peaks at lower potential range (+0.1 to+0.4 V), that grew up with CV‐cycling and attributed to the electro‐redox reactions of formed polymer film via electropolymerization. The electroanalytical monitoring of formed polymer oxidation peaks improved both sensitivity and detection limit by 35 and 10 times, respectively. The FT‐IR supported semiempirical prediction attributes the electropolymerization to the formation of ortho‐para and/or ortho‐meta CC coupled‐system.
Organic/Water Interface Electrochemistry for the Direct Detection of a Model Pesticide in Soybean Oil
Authors: Maynart M. C. , Silva R. M. P. , Suffredini H. B. 
Published: May 2013

AbstractAn electrochemical methodology was applied directly at an organic/water interface to detect a pesticide directly in oil, without the necessity of pre‐treatment of the sample. The oil phase was composed of soybean oil contaminated with carbendazim (methyl‐2‐benzimidazolecarbamate), and the aqueous phase consisted of a conventional BrittonRobinson buffer with a pH of 2. A boron‐doped diamond (BDD) electrode was placed directly at the interface of the two immiscible liquids. The ionic strength played an important role in the oxidation of carbendazim in our interfacial studies, as indicated by the oxidation currents varying from zero to 12 µA, depending on the position of the electrode.
Model updating method for substructure pseudo‐dynamic hybrid simulation
Authors: Kwon Oh‐Sung , Kammula Viswanath 
Published: May 2013

SUMMARYSubstructure hybrid simulation has been actively investigated and applied to evaluate the seismic performance of structural systems in recent years. The method allows simulation of structures by representing critical components with physically tested specimens and the rest of the structure with numerical models. However, the number of physical specimens is limited by available experimental equipment. Hence, the benefit of the hybrid simulation diminishes when only a few components in a large system can be realistically represented. The objective of the paper is to overcome the limitation through a novel model updating method. The model updating is carried out by applying calibrated weighting factors at each time step to the alternative numerical models, which encompasses the possible variation in the experimental specimen properties. The concept is proposed and implemented in the hybrid simulation framework, UI‐SimCor. Numerical verification is carried out using two‐DOF systems. The method is also applied to an experimental testing, which proves the concept of the proposed model updating method. Copyright © 2013 John Wiley & Sons, Ltd.
Multidegrees‐of‐freedom effective force testing: a feasibility study and robust stability assessment
Authors: Nakata Narutoshi , Krug Erin 
Published: May 2013

SUMMARYThis paper presents a feasibility study of multidegrees‐of‐freedom effective force testing (MDOF‐EFT). The study is intended to facilitate the development of a force feedback controller and investigation of performance as well as robustness of MDOF‐EFT. First, the dynamics of MDOF‐EFT systems are analytically investigated. Analytical transfer functions of the control plant, the valve‐to‐force relations, showed that the plant is dynamically coupled and the natural frequencies of test structures are the transmission zeros of the plant. Using a set of model parameters from a previous study, a case study that includes controller design, numerical simulations and robust stability assessment is performed. A decoupling loop shaping (DLS) controller consisting of a pseudo inverse of the plant and second‐order loop shaping controllers is adopted as the force feedback controller. It is shown that the DLS controller provides a stable control system while successfully decoupling the control loops and compensating the control‐structure interaction. Numerical simulations demonstrate that the DLS controller enables tracking of static and dynamic forces for multiple actuators. Robust stability of MDOF‐EFT with the DLS controller is assessed using Monte Carlo simulation. The stochastic simulation results show that the DLS controller is stable and robust, providing sufficient stability margins for uncertain models with maximum 50% errors in the estimated system parameters. This paper demonstrates that MDOF‐EFT is feasible with the DLS controller and can be implemented in experimental laboratories. Copyright © 2013 John Wiley & Sons, Ltd.
Patient and carer views on participating in clinical trials for prodromal Alzheimer's disease and mild cognitive impairment
Authors: Lawrence Vanessa , Pickett James , Ballard Clive , Murray Joanna 
Published: May 2013

ObjectiveThere is great interest in conducting clinical trials of disease‐modifying therapies in the prodromal (early, pre‐dementia), asymptomatic stages of Alzheimer's disease. Diagnostic biomarker tests offer a means of identifying prodromal patients, but it is unclear how potential participants feel about their use. Deciding whether to take part in a clinical trial is a complex process in which eligible participants must balance risks and discomforts against uncertain benefits. We sought to explore the views of potential participants through qualitative research methods.MethodsFocus groups with people with early memory problems, current and former family carers explored attitudes towards participating in clinical trials in the prodromal stages of the disease, using an example of anti‐amyloid antibody‐therapy (immunotherapy), which are currently in development.ResultsDespite the complexities involved, almost all participants had a clear idea about whether they, personally, would like to take part. Many were highly motivated to obtain an unambiguous diagnosis, regardless of their desire to participate in a clinical trial. Participants expressed minimal concern regarding the risk of adverse events associated with immunotherapy, whereas certain tests and trial procedures provoked greater anxiety. People with memory problems were found to assess the study demands in relation to their own priorities and circumstances.ConclusionsThe priorities of patients might be different to clinicians and those who design and regulate clinical trials. Patient views can be used to inform the ethical debate around the disclosure of biomarker status, the design of clinical trials and the content of trial information. Copyright © 2013 John Wiley & Sons, Ltd.
Evaluation of the effects of a metabotropic glutamate receptor 5‐antagonist on electrically induced pain and central sensitization in healthy human volunteers
Authors: Kalliomäki J. , Huizar K. , Kågedal M. , Hägglöf B. , Schmelz M. 
Published: May 2013

AbstractBackgroundThis study aimed to investigate the effect of a single dose of the mGluR5‐antagonist AZD9272 on electrically induced pain, central sensitization and axon reflex flare.MethodsThis was a randomized, double‐blind, placebo‐controlled crossover study. Twenty‐five healthy male volunteers received a single oral dose of AZD9272 or placebo on two occasions separated by 10–20 days. Electrical stimulation with a constant current for 100 min delivered through intracutaneous electrodes inserted on the forearm was used to induce a stable level of pain (6 of 10 on a 0–10 numerical rating scale; NRS). Pain intensity was assessed every 10 min during stimulation. The area of punctate hyperalgesia, area of dynamic mechanical allodynia, and area and intensity of flare reaction were measured every 20 min during stimulation. The stimulation procedure, current intensity and measurements were identical at both treatment visits. The AUC0–100 min (area under curve, 100 min stimulation) was calculated for each variable. The AUC0–100 min for pain NRS and hyperalgesia area were defined as primary variables. Linear mixed effects models were used for the statistical analysis.ResultsTwenty‐one subjects completed the study per protocol. No significant differences were found between AZD9272 and placebo regarding any of the AUC0–100 min variables for pain NRS, hyperalgesia area, allodynia area, flare area or flare intensity. The plasma levels of AZD9272 were maximal during the pain measurements and corresponded to >50% brain mGluR5 receptor occupancy.ConclusionSingle doses of the centrally acting mGluR5‐antagonist AZD9272 did not reduce C‐fibre evoked pain, central sensitization or flare reaction.
Ebselen Reduces the Toxicity of Mechlorethamine in A‐431 Cells via Inhibition of Apoptosis
Authors: Lulla Anju , Pino Maria A. , Piętka‐Ottlik Magdalena , Młochowski Jacek , Sparavalo Oleksiy , Billack Blase 
Published: May 2013

ABSTRACTA series of test compounds were evaluated for an ability to reduce the toxicity of the nitrogen mustard mechlorethamine (HN2) in vitro. The test compounds included resveratrol, pterostilbene, vitamin C, ebselen, ebselen diselenide, and ebselen‐sulfur. Among them, ebselen demonstrated the highest degree of protection against HN2 toxicity. To this end, pretreatment of the cells with ebselen offered protection against the toxicant whereas no protection was observed when cells were first incubated with HN2 and then treated with ebselen. Significant increases in caspase 3 and caspase 9 activities were observed in response to HN2, and ebselen was found to reduce these effects. Taken together, the data presented here indicate that ebselen is an effective countermeasure to nitrogen mustard in vitro, which is worthy of future investigation in vivo. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:313‐322, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21490
Localization of Scopolamine Induced Electrocortical Brain Activity Changes, in Healthy Humans at Rest
Authors: Ramos Reis Pedro Miguel , Eckhardt Holger , Denise Pierre , Bodem Friedrich , Lochmann Matthias 
Published: May 2013

AbstractTo prevent the participants of parabolic flights from nausea they are optionally treated with subcutaneously injected antiemetic scopolamine. The range of side effects of this substance include reductions of the α‐2 frequency band. Previous studies, however, have given no information as to which generator centers are responsible for this effect. The objective of this study therefore, is to identify the cortex area that may be responsible for this effect. Six participants were subcutaneously administered 0.7 mg of scopolamine. EEG was recorded for 10 minutes before to 20 minutes after injection. Data preprocessing followed including filtering and artifact minimization. A statistical analysis was performed with sLORETA/eLORETA software for each subject over a time window from 3 minutes before to 17–20 minutes after scopolamine injection. Results show, that in the BA7, the precuneus, on both hemispheres suffered a α‐2 activity decrease in absolute power. The identified brain cortex center is an important hub with high connectivity and centrality values within the neural network. It contributes to the control of movement and to space orientation. Therefore, an activity alteration in this area can possibly explain the antiemetic effect of scopolamine and open a window to understand the origin of motion sickness.
Simulation of permafrost and seasonally frozen ground conditions on the Tibetan Plateau, 1981–2010
Authors: Guo Donglin , Wang Huijun 
Published: May 2013

AbstractPermafrost and seasonally frozen ground conditions on the Tibetan Plateau were investigated using the Community Land Model, version 4 (CLM4), forced by a suite of new, high‐resolution data. This new data set was highly accurate and had an advantage in the frozen ground simulations for its fine temporal and spatial resolution. The simulated current (1981–2000) near‐surface permafrost area was 151.50 × 104 km2, which is close to, but slightly larger than, the range from previous studies (111.80 ~ 150.0 × 104 km2). The simulated current active layer thicknesses ranged from 0 to 4.74 m, with an average of 2.01 m. The other frozen ground parameters, such as the maximum freezing depths for seasonally frozen ground, the date of freeze start, the date of freeze end, and the freeze duration at 1 m depth, were also examined. Considering the issue of scale mismatch, the simulated soil temperature and other frozen ground parameters were reasonable compared to our observations. In response to the Plateau warming of approximately 0.44°C/decade from 1981 to 2010, the near‐surface permafrost area decreased at a rate of 9.20 × 104 km2/decade, and the area‐mean active layer thickness increased by 0.15 m/decade. The area‐mean maximum freezing depth of the seasonally frozen ground decreased by 0.34 m/decade. At a depth of 1 m, the dates of freeze start for permafrost and seasonally frozen ground delayed linearly by 3.8 and 4.0 days/decade, respectively, while the dates of freeze end for them advanced linearly by 5.9 and 4.6 days/decade, respectively. These trends in the dates of freeze start and freeze end resulted in freeze durations that were shortened by 9.7 and 8.6 days/decade for permafrost and seasonally frozen ground, respectively. These results give detailed permafrost and seasonally frozen ground states as well as their changes, which will be useful for studying frozen ground's response to climate change and frozen ground engineering stabilization.
Arc‐Disjoint Cycles and Feedback Arc Sets
Authors: Florek Jan 
Published: May 2013

AbstractIsaak posed the following problem. Suppose T is a tournament having a minimum feedback arc set, which induces an acyclic digraph with a hamiltonian path. Is it true that the maximum number of arc‐disjoint cycles in T equals the cardinality of minimum feedback arc set of T? We prove that the answer to the problem is in the negative.
Influence of climate change on IDF curves for the metropolitan area of Barcelona (Spain)
Authors: Rodríguez Raul , Navarro Xavier , Casas M. Carmen , Ribalaygua Jaime , Russo Beniamino , Pouget Laurent , Redaño Angel 
Published: May 2013

ABSTRACTThe evaluation of the possible climate change influence on extreme precipitation is very interesting in the Mediterranean area due to the usual and characteristic high intensities of its rainfall pattern. This analysis is also very important in urban zones, especially those densely populated with complex sewer systems, generally vulnerable to torrential rainfall. In this work, a total of 114 simulated daily rainfall series, 84 for the period 2000–2099 and 30 for the control period 1951–1999, have been analysed. These series were obtained for six thermo‐pluviometric stations located in the metropolitan area of Barcelona using the information provided by five general circulation models under four future climate scenarios of greenhouse gas emissions and applying statistical downscaling methods. The potential changes in the intensity–duration–frequency relationships due to climate change have been investigated. For the last third of the 21st century, under A1B, A2 and B2 climate scenarios, an increase of at least 4% has been found on the expected daily rainfall with return period longer than 20 years. Using a temporal downscaling based on scaling properties of rainfall, future hourly extreme rainfall has been estimated. For almost all the scenarios and periods considered, the increase on the expected hourly rainfall has resulted slightly higher than the corresponding daily rainfall. The greatest differences between the future hourly and daily rainfall estimated have been found in the second third of the century under scenarios A1B (8%) and A2 (9%). © 2013 Royal Meteorological Society
Biomechanical properties of the plantar flexor muscle–tendon complex 6 months post‐rupture of the achilles tendon
Authors: McNair Peter , Nordez Antoine , Olds Margie , Young Simon W. , Cornu Christophe 
Published: May 2013

ABSTRACTWe compared the effects of a non‐weight bearing protocol (NWB) and a weight bearing (WB) protocol on energy stored, stiffness, and shock absorption in the plantar flexor muscle–tendon unit of patients managed non‐operatively following an Achilles tendon rupture. Thirty‐eight subjects were randomized to a WB cast fitted with a Bohler iron or a traditional non‐weight‐bearing cast. At a 6‐month follow‐up, a biomechanical assessment utilizing an isokinetic dynamometer allowed measurement of peak passive torque, energy stored, shock absorption, and stiffness. The WB group had greater peak passive torque (∼20%). Irrespective of group, peak passive torque in unaffected legs was greater (∼26%) than affected legs. Across the groups, energy stored in the NWB group was 74% of the WB group. The energy stored in affected legs was 80% of that in unaffected legs. Shock absorption was not significantly different across legs or groups. Irrespective of group, affected legs had significantly less stiffness (20–40%). While the augmentation of plaster with a Bohler iron to allow increased weight bearing had positive effects, deficits in affected compared to unaffected legs irrespective of group were notable, and should be addressed prior to participation in vigorous physical activities. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1469–1474, 2013
The effects of potassium fertilization on water‐use efficiency in crop plants
Authors: Grzebisz Witold , Gransee Andreas , Szczepaniak Witold , Diatta Jean 
Published: May 2013

AbstractThe supplies of water and nitrogen to a plant during its critical stages of growth are the main factors that define crop yield. A crop experiences irregular water deficits during its life cycle in rain‐fed agriculture. An effective anti‐stress‐oriented approach therefore ought to focus on increasing the units of water productivity. The main objective of this conceptual review is to confirm that adequate K management can be used as an important tool to alleviate the negative effects of water deficit on plant growth, yield‐component formation, and yield. The French and Schultz approach of using the water‐limited yield (WLY) was modified in this review into a graphical form and was used to discriminate between yield fractions that depended on the volume of transpired water from those that were induced by K fertilizer. By using this method, it was possible to demonstrate the extent of several crop (winter wheat, spring triticale, maize, sugar beet) responses to the K supply. Yield increases resulting from K application mostly appeared under conditions of mild water deficit. As described for sugar beet, finding the critical period of crop K sensitivity is a decisive step in understanding its impact on water‐use efficiency. It has been shown that an insufficient supply of K during crucial stages in the yield formation of cereals (wheat, spring triticale), maize, and sugar beet coincides with a depressed development in the yield components. The application of K fertilizer to plants is a simple agronomic practice used to increase crop tolerance to a temporary water shortage. It may be that the improvement of a plant's access to K during mild water‐deficiency stress will increase water uptake by the root cells, which in turn increases their osmotic potential and thereby allows extension growth. This growth in turn promotes access to other mineral elements (including nitrogen) and water, which favor plant growth and yield.
Feasibility study of novel fast‐switching liquid crystal displays using electric birefringence effect
Authors: Kosuge Masahiro , Naemura Shohei , Fujimura Kaoru 
Published: May 2013

AbstractBoth theoretical and experimental studies were made on electric birefringence effect of nematic liquid crystals in isotropic phase with respect to its applicability to novel LCDs. It was confirmed that response times are <1 ms, and a critical point exists where electro‐optic hysteresis vanishes. Substrate surface treatments were also found to improve the electro‐optic characteristics. The results are promising for both projection and direct view display applications featuring fast switching and high image quality.