bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flavonoids, taxifolin and luteolin attenuate cellular melanogenesis despite increasing tyrosinase protein levels
Authors: An Sang Mi , Kim Hyo Jung , Kim Jung‐Eun , Boo Yong Chool 
Published: August 2008

AbstractFlavonoids are a group of polyphenolic compounds widely distributed in plants. Their potent bio‐activities and relatively low toxicity have rendered them useful ingredients in functional cosmetics. The purpose of the present study was to examine their potential effects on cellular melanogenesis. When tested in murine melanoma B16F10 cells activated by α‐melanocyte stimulating hormone (α‐MSH), taxifolin and luteolin inhibited the cellular melanogenesis as effectively as arbutin, one of the most widely used hypopigmenting agents in cosmetics. As opposed to their antimelanogenic effects, taxifolin and luteolin rather increased the tyrosinase protein levels in the absence and presence of α‐MSH. However, these flavonoids effectively inhibited tyrosinase‐catalysed oxidation of l‐dihydroxyphenylalanine in cell‐free extracts and in living cells. Furthermore, they attenuated cell pigmentation induced by expression of exogenous human tyrosinase. Therefore, the antimelanogenic effects of taxifolin and luteolin are attributed to their inhibitory effects on tyrosinase enzymatic activity, despite their effects on increasing tyrosinase protein levels. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of the antidiabetic activity of Berberis lyceum root extract and berberine in alloxan‐induced diabetic rats
Authors: Gulfraz M. , Mehmood S. , Ahmad A. , Fatima N. , Praveen Z. , Williamson E. M. 
Published: August 2008

AbstractBerberine has been shown to have hypoglycaemic activity in several in vitro and in vivo models, although the mechanism of action is not fully known. Berberis lyceum Royle root produces high concentrations of berberine, and in traditional medicine, the whole extract of this plant is used widely to treat diabetes. The antidiabetic activity of the ethanol root extract of Berberis lyceum was compared with pure berberine in normal and alloxan‐diabetic rats using similar doses of each. The concentration of berberine in the extract was determined to be 80% dry weight with only trace amounts of other alkaloids present. The purpose of the study was to investigate the effects of berberine and a whole extract of Berberis lyceum on blood glucose and other parameters associated with diabetes, to compare the effects of the crude extract with those of pure berberine and thus validate its use as a therapeutic agent, and finally to identify any contribution of the other components of the extract to these effects.Oral administration of 50 mg/kg of Berberis extract and berberine to normal and experimental diabetic rats produced a significant (p < 0.05) reduction in blood glucose levels from days 3–7 days of treatment. Significant effects were also observed on the glucose tolerance, glycosylated haemoglobin, serum lipid profiles and body weight of experimental animals. Berberis extract and berberine demonstrated similar effects on all parameters measured, and although the extract was comparable in efficacy to berberine, it did not produce any effects additional to those shown by pure berberine. The results support the use of the extract in traditional medicine, and demonstrate that apart from being a highly cost‐effective means of treating with berberine, the total extract does not appear to confer any additional benefits or disadvantages compared with the pure compound. Copyright © 2008 John Wiley & Sons, Ltd.
Towards a consistent numerical compressible non‐hydrostatic model using generalized Hamiltonian tools
Authors: Gassmann Almut , Herzog Hans‐Joachim 
Published: August 2008

AbstractA set of compressible non‐hydrostatic equations for a turbulence‐averaged model atmosphere comprising dry air and water in three phases plus precipitating fluxes is presented, in which common approximations are introduced in such a way that no inconsistencies occur in the associated budget equations for energy, mass and Ertel's potential vorticity. These conservation properties are a prerequisite for any climate simulation or NWP model.It is shown that a Poisson bracket form for the ideal fluid part of the full‐physics equation set can be found, while turbulent friction and diabatic heating are added as separate ‘dissipative’ terms. This Poisson bracket is represented as a sum of a two‐fold antisymmetric triple bracket (a Nambu bracket represented as helicity bracket) plus two antisymmetric brackets (so‐called mass and thermodynamic brackets of the Poisson type).The advantage of this approach is that the given conservation properties and the structure of the brackets provide a good strategy for the construction of their discrete analogues. It is shown how discrete brackets are constructed to retain their antisymmetric properties throughout the spatial discretisation process, and a method is demonstrated how the time scheme can also be incorporated in this philosophy. Copyright © 2008 Royal Meteorological Society
The influence of background wind direction on the roadside turbulent velocity field within a complex urban street
Authors: Smalley R. J. , Tomlin A. S. , Dixon N. S. , Boddy J. W. D. 
Published: August 2008

AbstractThe turbulent velocity field within a complex urban street in the city of York, United Kingdom was measured over a one‐month period, with data coverage over a wide range of background wind directions, θref (where θref = 0° is relative to the street axis, and angles increasing clockwise). Within the street, a persistent mean‐flow cross‐street circulation exists for 15° ⩽θref < 165° in addition to possible flow convergence for 240° ⩽θref < 300° . The magnitude of the in‐street normalised turbulent kinetic energy (TKE) is dependent on the type of predominant in‐street mean‐flow structures. During conditions that correspond to mean‐flow cross‐street circulation, the TKE is approximately twice the magnitude on the windward side compared with the leeward side. For nearly all wind directions, and on both sides of the street, the TKE is approximately constant with height for 0.4 < z/H < 0.8. There is evidence that the in‐street TKE increases with background TKE when other meteorological influences are relatively constant. For background wind directions free from mean flow convergence, the least variability in the sector‐averaged turbulence data occurs when the TKE is normalised by the in‐street mean wind speed, rather than the background wind speed. The two‐point cross‐correlation of the vertical‐velocity component fluctuations on the windward side is at least 0.6 between the mid and upper anemometers. The two‐point cross‐correlation between cross‐street (same height) vertical‐velocity component fluctuations is negative and non‐negligible during mean‐flow circulation, which indicates possible cross‐street coherence in the turbulent velocity field. The turbulent Reynolds stress anisotropy tensor, which provides an indication of the level of TKE redistribution between the components, and the overall level of turbulence anisotropy, is discussed with reference to the mean‐flow structures within the street. Copyright © 2008 Royal Meteorological Society
Perspectives on team dynamics: Meta learning and systems intelligence
Authors: Luoma Jukka , Hämäläinen Raimo P. , Saarinen Esa 
Published: August 2008

AbstractLosada observed management teams develop their annual strategic plans in a lab designed for studying team behaviour. Based on these findings he developed a dynamical model of team interaction and introduced the concept of meta learning (ML) which represents the ability of a team to avoid undesirable attractors. This paper analyses the dynamic model in more detail and discusses the relationship between ML and the new concept of systems intelligence (SI) introduced by Saarinen and Hämäläinen. We propose that the ML ability of a team clearly represents a systems intelligent competence. Losada's mathematical model predicts interesting dynamic phenomena in team interaction. However, our analysis shows how the model also produces strange and previously unreported behaviour under certain conditions. Thus, the predictive validity of the model also becomes problematic. It remains unclear whether the model behaviour can be said to be in satisfactory accordance with the observations of team interaction. Copyright © 2008 John Wiley & Sons, Ltd.
Functional supramolecular systems with highly cooperative and responding properties
Authors: Nabeshima Tatsuya , Akine Shigehisa 
Published: August 2008

AbstractThe dynamic processes of host–guest interactions contribute to the multistep regulation of various molecular functions such as the catalysis of chemical reactions, transport of materials, control of reaction pathways, and cooperative and responsive phenomena particularly in biological systems. In this review, we describe artificial metallo‐supramolecular systems, which exhibit highly cooperative and responsive functions to external stimulus, by utilizing formation of the metal complexes and their characteristic properties. Pseudomacrocycles such as pseudocrown ethers and pseudocryptands have been synthesized to control macrocyclic and macrobicyclic effects on guest recognition by using a metal ion as an effector, and remarkably positive and negative allosteric effects have been achieved. Highly cooperative stepwise regulation of the affinity to anions has also been achieved by a pseudocryptand and a salt‐binding host. The electrostatic interactions between the anions and cations are important for the combination specificity of the salts. We also introduce a linear bis‐salamo ligand as a precursor for a novel multimetal cooperative host. A trinuclear zinc complex was formed cooperatively and only the central zinc ion was replaced by lanthanide and calcium ions in a transmetalation way. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 240–251; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20153
Derivation of coupled impedance equation of a transformer and its application
Authors: Lee Kwang‐Jeek , Park Gooman 
Published: August 2008

AbstractWhen the load of a resonant transformer is variable, it is complicated to find the value of the quality factor Q of the primary circuit of the transformer because the coupled impedance operated by the secondary circuit of the transformer has a great effect on its primary circuit. Therefore, the only way to find out Q is to get the ratio of the inductor voltage V1 of the primary of the transformer to the voltage of the source Vg, which must be measured by equipment such as oscilloscopes.In this paper we have derived a new equation for the coupled impedance including the coupling coefficient k, the turns ratio n, the resistive load R0, and the reactance XL1 of the primary of the transformer as the main parameters from the existing equation of coupled impedance. And we derived an equation for the quality factor Q, which involves the coupled impedance in series with the resonant circuit of the transformer.When R0 ≥ 2XL2, for quality factor Q, the errors in its theoretical values are less than 3.98% of its measured values. And in the case of the load voltage V0, all errors in the theoretical values are less than 2.65% of its measured values. Moreover, we also analyzed a typical transformer by using the derived equation for coupled impedance. Then, in the case of the load voltage V0, when the load is variable, the difference of its measured values from the theoretical ones is less than 5.18%. As a result, the newly derived equation for coupled impedance is very useful to analyze the characteristics of a typical transformer as well as a series resonant transformer which has many benefits by virtue of the quality factor Q. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Numerical techniques for accurate evaluation of overhead line and underground cable constants
Authors: Noda Taku 
Published: August 2008

AbstractAccurately calculating the electrical constants of a transmission line, such as an overhead line or an underground cable, is of crucial importance for various types of power system simulations. This article presents some techniques as elements for accurately calculating the transmission line constants. One is a numerical integration technique for rigorously evaluating the ground‐return impedance of a transmission line. The technique achieves specified accuracy such as a relative error of 10−6 with practical computation time and is applicable both to overhead lines and underground cables. A technique to calculate conductor‐internal impedances, which preserves at least 7 digits of accuracy, is also presented. For the constant calculations of coaxial cables, a systematic procedure for converting the loop impedances of coaxial conductors into their series impedance matrix is derived. Finally, a method for properly sorting modal quantities to obtain their smooth frequency responses, while considering eigenvalue degeneracy, is given. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Design of a robust current controller to position estimation error for positioning of a sensorless control of interior permanent magnet synchronous motors under high‐speed drives
Authors: Hasegawa Masaru , Matsui Keiju 
Published: August 2008

AbstractThis article proposes a new current controller for high‐speed drives in interior permanent magnet synchronous motors (IPMSMs) with position sensorless control. It has been pointed out that the conventional current control systems become unstable under high‐speed drives. First, this article shows that rotor position estimation error causes unstable current control, and this instability is especially emphasized at high speed. To overcome this instability, this article proposes a simple modified controller with 2DOF structure, the design of which is also explained. Stability, using the proposed current controller, is then analyzed theoretically, and the proposed controller can extend the stable region for IPMSM position sensorless control, which is an improvement over conventional systems. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Development of recursive interpolated D/FFT for on‐line and highly accurate frequency analysis
Authors: Kuraishi Takashi , Kawada Masatake , Isaka Katsuo 
Published: August 2008

AbstractFrequency analysis of digital signals based on discrete/fast Fourier transform (D/FFT) inevitably has some inherent drawbacks such as short‐and long‐range leakage. As one of the methods to overcome the above drawbacks, interpolated discrete/fast Fourier transform (IpD/FFT) has been proposed. IpD/FFT has the ability to improve accuracy considerably. We proposed IpD/FFT, combined with recursive algorithm (RA), to achieve on‐line calculation. By evaluating the errors of the proposed method due to short‐and long‐range leakage, we showed that the proposed method can provide more accurate performance compared with recursive DFT (R‐DFT). © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A study of lightning risk
Authors: Shindo Takatoshi , Suda Tomotaka 
Published: August 2008

AbstractIt is important to establish a lightning risk management scheme for rational insulation design. In this paper, lightning risk assessment is carried out for a customer facility and a wind turbine blade. The calculated values of lightning risk agree with field experiences. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Room temperature operation of surface‐conduction single chamber fuel cell using a novel inorganic electrolyte as proton conductor
Authors: Nagata Akiyoshi , Nosaka Hidehiko , Yoshimura Yutaro , Kimura Takeshi 
Published: August 2008

AbstractThe performance at room temperature of a single chamber fuel cell (SCFC) using a novel pseudboehmite (pb) proton conductor as the inorganic electrolyte, which can operate in the gas mixtures of hydrogen and oxygen, is studied based on the dependence on the soaked treatments of the pb electrolyte, generated from the aluminum film. The surface‐conduction SCFC with a new electrode arrangement, moreover, operated at room temperature in the dry and wet gas mixtures. Maximum open circuit voltage (OCV) of 540 mV was achieved at room temperature operation in the wet gas mixture using the pb electrolyte generated by the soaked treatment of 60 °C. The OCV property in the dry gas mixture falls by a half value when compared to the case of the wet gas mixtures. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Numerical simulation of hydrogen storage into a single‐walled carbon nanotube in a plasma
Authors: Yamaguchi Hiroyuki , Nejoh YasuNori 
Published: August 2008

AbstractA model of the hydrogen storage into a single‐walled carbon nanotube (SWNT) in a plasma is studied by numerical simulation. It is demonstrated for the first time that a proton entering into the SWNT shows a two‐dimensional trajectory even though the SWNT is capped when Lennard‐Jones and Coulomb potentials exist. The conditions for the proton to enter into the SWNT are that the carbon atoms should be negatively charged and the potential formed by the SWNT at the center of its hexagonal structure is negative. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Pediatric otolaryngologists' actions regarding secondhand smoke exposure: Pilot data suggest an opportunity to enhance tobacco intervention
Authors: Mueller Darryl T. , Collins Bradley N. 
Published: August 2008

OBJECTIVETo assess pediatric otolaryngologists' training, actions, and attitudes with respect to patients exposed to secondhand smoke.STUDY DESIGNCross‐sectional survey.SUBJECTSPediatric otolaryngologists and senior residents.METHODSAn anonymous, Web‐based survey of pediatric oloaryngologists was designed to capture demographics, tobacco‐specific education, actions, and attitudes. Responses were analyzed descriptively and entered into logistic regression models to determine predictors of adherence to the basic tenets of the general pediatrics secondhand smoke exposure‐prevention guidelines.RESULTSOne hundred‐fifteen US physicians completed the survey. Descriptive analysis revealed low levels of training and low levels of tobacco‐specific intervention among respondents. Logistic regression models showed that greater tobacco‐specific knowledge/education and fewer perceived barriers predicted greater adherence to the basic tenets of the pediatrics guidelines.CONCLUSIONOur pilot study provides preliminary evidence that can guide specific improvements in tobacco‐intervention training for pediatric otolaryngologists and residents.
Evaluation of prognostic factors and middle ear risk index in tympanoplasty
Authors: Pinar Ercan , Sadullahoglu Kerim , Calli Caglar , Oncel Semih 
Published: August 2008

OBJECTIVEThe aim of this study was to examine the role of the prognostic factors and middle ear risk index on the success of tympanoplasty.STUDY DESIGNCase series.SUBJECTS AND METHODSThe charts of 231 patients who underwent tympanoplasty operations between 2002 and 2007 were reviewed. Prognostic factors such as age, sex, presence of systemic diseases, location and size of perforation, duration of dry period, presence of myringosclerosis, presence of septal and conchal pathology, operation type, and status of the opposite ear and middle ear risk index were investigated.RESULTSThe overall success rate was 74.4%. Multivariate analysis was carried out on significant prognostic factors to obtain independent variables and yielded the following results (95% CI): size of the perforation (<50%) (OR:8.11), healthy opposite ear (OR:5.64), more than 3 months dry period (OR:2.21), absence of myringosclerosis (OR:4.01) and low middle ear risk index (OR:87.1).CONCLUSIONSize of the perforation(<50%), healthy opposite ear, absence of myringosclerosis, more than 3 months dry period, and low middle ear risk index were found to be significant independent prognostic factors.
Double‐blind, placebo‐controlled trial with esomeprazole for symptoms and signs associated with laryngopharyngeal reflux
Authors: Reichel Oliver , Dressel Holger , Wiederänders Katrin , Issing Wolfgang J. 
Published: August 2008

OBJECTIVETo determine the efficacy of proton pump inhibitor (PPI) therapy with esomeprazole on symptoms and signs associated with laryngopharyngeal reflux (LPR).STUDY DESIGN AND METHODSProspective, double‐blind, randomized, placebo‐controlled study. Sixty‐two patients with a reflux finding score (RFS) > 7 and a reflux symptom index (RSI) > 13 were enrolled and received either esomeprazole 20 mg twice daily or placebo for three months. RSI and RFS were assessed at baseline, after six weeks, and after three months.RESULTSReductions of total RSI and RFS as well as of several subscores were significantly higher in the treatment group compared to placebo after three months (P < 0.05 each). The difference between study groups was most pronounced for posterior commissure hypertrophy (P < 0.01).CONCLUSIONIn the treatment of LPR‐related symptoms a high placebo effect can be observed. However, compared to control, twice‐daily PPI treatment for three months demonstrated a significantly greater improvement in laryngeal appearance and LPR symptoms.
Pharyngeal adaptation in Zenker's diverticulum: The “faux pharyngoesophageal segment”
Authors: Leonard Rebecca , Belafsky Peter , McKenzie Susan 
Published: August 2008

BackgroundWe have noticed a protrusion on the pharyngeal wall in patients with Zenker's diverticulum (ZD). The protrusion gives the appearance of a neo‐pharyngoesophageal segment (faux‐PES) and may represent an adaptation to protect the airway.Study DesignA case‐control study.MethodologyThe fluoroscopic swallow studies of patients with ZD were compared with matched controls. Information regarding the presence and location of a faux‐PES, true PES opening, pharyngeal constriction, and laryngohyoid elevation was compared.ResultsThe fluoroscopic swallow studies of 31 patients with ZD were compared with 31 controls. A faux‐PES was found in 100 percent of ZD patients and in 0 percent of controls. The mean maximum opening of the faux‐PES was 1.5 (±0.27) cm. The faux‐PES was located 1 cm above the true PES below the entrance to the supraglottic airway. This is the optimal location for airway defense.ConclusionsThe faux‐PES was identified in 100 percent of patients with ZD. The faux‐PES may represent a physiologic adaptation to protect the airway from regurgitation out of a ZD.
Risks of allergy vial contamination: Comparison of mixing in‐office versus under ventilation hood
Authors: Lay P. Chase , Bass Richard , Hughes Larry F. , Lin Sandra Y. 
Published: August 2008

ObjectiveCompare the risk of bacterial contamination of allergy immunotherapy vials prepared in‐office versus those mixed under a ventilation hood.Study DesignProspective single‐blinded study.SettingTertiary otolaryngology outpatient clinic.ResultsFive hundred thirty‐seven vials were prepared and cultured for aerobes and anaerobes over an 11‐month period. Three hundred twenty vials were arbitrarily assigned to in‐office preparation and 217 to under‐hood preparation. A total of two positive cultures occurred in vials prepared in‐office and one from under‐hood preparation. Follow‐up cultures of these three vials were all negative. No patients receiving injections had signs or symptoms of skin or systemic infections from the injections.ConclusionOur results suggest that the risk of bacterial contamination in immunotherapy vials in both groups is rare.