bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chaos from a current‐programmed ćuk converter
Authors: Tse C. K. , Chan W. C. Y. 
Published: July 2007

AbstractThe chaotic dynamics of a current‐programmed Ćuk converter having no voltage feedback is studied. an iterative map that describes the operation of the circuit is derived, from which a route to chaos similar to that from a ‘tent’ map is predicted. Computer simulation based on an exact piecewise switched model confirms the predicted route to chaos.
Darwin: Analogue circuit synthesis based on genetic algorithms
Authors: Kruiskamp Wim , Leenaerts Domine 
Published: July 2007

AbstractDARWIN is a synthesis tool for generating sized net lists of CMOS op amps from performance specifications and process parameters. the synthesis process starts with an initial set of randomly generated op amps. Owing to genetic operator ‘crossover’ and ‘mutation’, the population of op amps evolves to a population in which several op amps meet the required specifications. During the synthesis process the circuit topology and circuit parameters (capacitor values, bias currents and transistor lengths and widths) evolve simultaneously with the final solution. the circuit description we use in the genetic algorithm ensures that all intermediately generated circuits possess a number of qualities that are required for a correct functioning of the circuit. Synthesis experiments have shown that DARWIN is capable of synthesizing functional circuits without the need of much design knowledge.
A modified sensitivity measure for linear digital systems
Authors: Xiao Chengshan 
Published: July 2007

AbstractIn this paper a new sensitivity measure for state space systems is proposed. This new measure is a modified form of Tavsanoglu and Thiele's measure but has three advantages: (1) it is more precise than Tavsanoglu and Thiele's measure when the parameters of the state space realizations contain 0 and ±1; (2) it can be used to explain why the sparse Schur and Hessenberg realizations can give better actual sensitivity performance than the corresponding fully parametrized optimal realizations; (3) it is identical with the global round‐off noise gain G = tr(QW) + y obtained by Hwang under a dynamic constraint.
CYP2R1 (vitamin D 25‐hydroxylase) gene is associated with susceptibility to type 1 diabetes and vitamin D levels in Germans
Authors: Ramos‐Lopez Elizabeth , Brück Patrick , Jansen Thomas , Herwig Jürgen , Badenhoop Klaus 
Published: July 2007

AbstractBackgroundThe vitamin D system has been implicated in type 1 diabetes by epidemiological and immune intervention studies as well as by polymorphisms of the vitamin D binding protein (DBP) and CYP27B1 genes. CYP2R1, a cytochrome P450 enzyme, catalyzes the formation of vitamin D3 to 25‐hydroxyvitamin D3 (25(OH)D3), the main circulating vitamin D metabolite.MethodsTwo hundred and three simplex type 1 German diabetes families (609 subjects) were genotyped for the rs10741657 and for the rs12794714 polymorphisms. 25(OH)D3 levels were measured and correlated with CYP2R1 polymorphisms in 133 type 1 diabetes patients as well as its mRNA expression from peripheral blood mononuclear cells (PBMCs) in 58 type 1 diabetes patients.Frequencies and genotypes of the CYP2R1 polymorphisms were analyzed using Haploview software version 3.2. The correlation between 25(OH)D3 and CYP2R1mRNA with the genotypes of the rs10741657 and rs12794714 polymorphism was evaluated by Wilcoxon‐Mann–Whitney‐ and ANOVA test using Bias Statistical package 7.01.ResultsWhereas the rs12794714 polymorphism was not associated with type 1 diabetes the variant ‘G’ of the rs10741657 polymorphism was more often transmitted to affected offspring (61% vs 39% P = 0.004) and was also more frequent in cases than in controls (46.1% vs 35.7%, P = 0.03).Patients carrying the genotype ‘GG’ or ‘GA’ of the rs10741657 polymorphism possessed, on average, lower levels of 25(OH)D3 compared to those with the genotype ‘AA’ (P = 0.003, Pc = 0.01 and P = 0.01, Pc = 0.04, respectively).ConclusionThus, our findings reveal a novel association of CYP2R1 polymorphisms in patients with type 1 diabetes and with their circulating levels of 25(OH)D3. Copyright © 2007 John Wiley & Sons, Ltd.
The use of multiple purging methods as an indicator of eating disorder severity
Authors: Edler Crystal , Haedt Alissa A. , Keel Pamela K. 
Published: July 2007

AbstractObjective:Previous studies indicate a distinction between those who use one versus multiple methods of purging, but these studies have not controlled for differences in purging frequency. The current study examined whether purging frequency or the use of multiple purging (MP) methods provides more information about eating disorder severity.Method:Existing data were reanalyzed to examine associations between facets of purging and psychological measures among women with bulimia nervosa, purging disorder, and controls. Analyses compared the use of MP methods and purging frequency as indicators of eating pathology.Results:MP methods demonstrated associations with greater eating disorder severity; purging frequency was associated with increased binge frequency and general psychopathology.Conclusion:The presence of MP methods provides more information about eating disorder severity than purging frequency, which seems to be a marker of related psychopathology. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
The influence of success and failure experiences on agency
Authors: Abele Andrea E. , Rupprecht Thomas , Wojciszke Bogdan 
Published: July 2007

AbstractAgency is—besides communion—a basic dimension of traits. It can be specifically linked to behavioral outcomes, to status, mastery, self‐esteem and to success. The present paper analyzes the situational malleability of agency. Two studies tested whether an individual's agency (but not communion) is situationally influenced by the experience of success versus failure at a task, as well as whether this effect is the same for men and women. Supporting our hypotheses, the induction of success versus failure experiences led to changes in agency that were independent of actual performance, independent of type of task (memorizing vs. face recognition), independent of induction methodology (easy vs. difficult task vs. manipulated performance feedback), and independent of self‐esteem, initial level of agency and of the participants' gender. Communion was not influenced by this kind of experience. Implications for both the basic dimension of agency and for theories on gender and gender stereotypes are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Motivated self and recall: visual perspectives in remembering past behaviors
Authors: Sanitioso Rasyid Bo 
Published: July 2007

AbstractThe present study examined motivational influences on visual perspectives in remembering past events and behaviors. Participants were first induced to believe that extraversion or introversion is conducive of success. Next, they recalled in details two introverted past behaviors. Introversion‐success participants, presumably motivated to see themselves as introverted, recalled and visualized the behaviors more from a first‐person actor perspective than did extraversion‐success participants (who recalled the behaviors from a third‐person observer perspective). Remembering past behaviors from a first‐person actor perspective implies that the behaviors are true of the self and impacts self‐definition to a relatively greater degree. The findings thus extend the influence of desired self to how people remember past events. They also contribute to the integration of motives in research on the link between self‐inferences and the subjective experience of remembering. Copyright © 2007 John Wiley & Sons, Ltd.
Pilot scale SO2 control by dry sodium bicarbonate injection and an electrostatic precipitator
Authors: Pilat Michael J. , Wilder James M. 
Published: July 2007

AbstractA 500 actual cubic feet gas per minute (acfm) pilot‐scale SO2 control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400°F (204.5°C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO2. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO2 concentrations were measured upstream of the reagent injection, 25‐ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO2 collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in‐duct SO2 removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide–sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature. © 2007 American Institute of Chemical Engineers Environ Prog, 2007
A combined S‐transform and fuzzy expert system for phase selection in digital relaying
Authors: Samantaray S. R. , Dash P. K. , Panda G. 
Published: July 2007

AbstractThis paper presents a new approach for faulty phase selection in transmission line based on combined S‐transform and Fuzzy Expert System (FES). The S‐transform with complex window is used to generate S‐contours (time–frequency contours), which ‘time‐localizes’ the fault. Features such as standard deviation (sd) and change in energy (ce) of the S‐contours for half cycle post fault current samples are calculated and fuzzified with simple triangular membership function. The fuzzified inputs are fed to the FES and the corresponding fuzzy rule is fired to provide the output as “1” for faulty phase and ground involved and “0” for no‐fault. The proposed integrated approach is tested for all 11 types of shunt faults with a wide range of operating conditions of the power system network. For testing the robustness of the proposed technique, the same is applied for the faults created on experimental set up with different operating conditions and provides accurate results. The output from the FES shows the fastness of the proposed technique and thus suitable for online application. Copyright © 2007 John Wiley & Sons, Ltd.
Flux variation in a Siberian taiga forest near Yakutsk estimated by a one‐dimensional model with routine data, 1986–2000
Authors: Yamazaki Takeshi , Ohta Takeshi , Suzuki Rikie , Ohata Tetsuo 
Published: July 2007

AbstractFor a larch forest site near Yakutsk, energy and water fluxes are estimated and their variations are investigated using a one‐dimensional land surface model with daily routine data. The estimation period is 1986–2000, including the period before the start of tower observation (1997) on the left bank of the Lena River. The land surface model includes three submodels: vegetation, snow cover, and soil. The model can calculate water and energy fluxes above and within the forest if meteorological data over the forest are given as input. Data used in this study are Baseline Meteorological Data in Siberia (BMDS) Version 3. This set comprises daily data of main meteorological elements. The procedure is as follows: (1) preparation of equations between routine Yakutsk data and larch tower data; (2) estimation of past meteorological data over the taiga using those equations; and (3) estimation of fluxes using the one‐dimensional model. The date of leaf‐out start is parameterized with soil temperature and accumulated air temperature. It corresponds to the green‐up time obtained from satellite normalized difference vegetation index (NDVI) data. Estimated monthly deviation of net radiation, Rn, is 10 Wm−2. Its maximum is 20 Wm−2. The monthly deviation of latent heat flux, LE, is less than 12 Wm−2. Its warm season average is less than 7 Wm−2. Although the magnitude of LE is almost zero in December and January, and several Wm−2 aside from these 2 months, the sensible heat flux, H, sometimes becomes negative during the cold season. The variation of evapotranspiration is considerably smaller than that of precipitation. The evapotranspiration (E) normalized by potential evaporation (Ep), E/Ep is 0·37–0·44 in the warm season; it tends to be large when leaf‐out starts early. The amount of evapotranspiration in the warm season can be estimated from Ep within an error of 5 mm using this relationship. Copyright © 2007 John Wiley & Sons, Ltd.
Osteoblast adhesion and morphology on TiO2 depends on the competitive preadsorption of albumin and fibronectin
Authors: Sousa S. R. , Lamghari M. , Sampaio P. , Moradas‐Ferreira P. , Barbosa M. A. 
Published: July 2007

AbstractThis study aims at assessing the influence of the competitive preadsorption of human serum albumin (HSA) and human plasma fibronectin (FN) from binary solutions and 10% plasma on MC3T3‐E1 osteoblast adhesion and morphology on two types of TiO2 substrates. One was commercially pure titanium with a titanium oxide layer formed in an H2O2 solution and the other TiO2 sputtered on Si (Sousa et al., Langmuir 2004; 20:9745–9754.). The strategy applied in the present investigation was to compare osteoblast adhesion to surfaces preadsorbed with HSA, FN, HSA/FN = 1, HSA/FN = 200, and 10% plasma. The adsorption of proteins was evaluated measuring the amount and the effectiveness of binding with radiolabeled proteins, 125I‐FN and 125I‐HSA. Our results indicated that MC3T3‐E1 osteoblast adhesion correlates well with the amounts of FN and HSA adsorbed on TiO2 surfaces. Also, we found that fewer osteoblasts adhered to both substrates preadsorbed with HSA, HSA/FN = 200, and 10% plasma, after 4 and 24 h, than to the surfaces preadsorbed with FN and HSA/FN = 1. For the latter, FN was able to compensate the inhibitory effect of HSA on osteoblast adhesion. Therefore, the presence of lower amounts of coadsorbed albumin may improve presentation of FN in a more integrin‐recognized conformation, suggesting that some degree of molecular packing prevents loss of integrin‐binding activity. FN reversibility does not seem to be dependent on the HSA/FN adsorption mass ratio in solution, suggesting that FN competitively adsorbs to TiO2 in a favorable conformation and does not suffers subsequent conformational changes allowing exchange with other FN molecules in solution. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Matrix metalloproteinases and their inhibitors in the foreign body reaction on biomaterials
Authors: Jones Jacqueline A. , McNally Amy K. , Chang David T. , Qin L. Abigail , Meyerson Howard , Colton Erica , Kwon I.L. Keun , Matsuda Takehisa , Anderson James M. 
Published: July 2007

AbstractMatrix metalloproteinases (MMPs) can degrade structural components within the extracellular matrix and at the cellular surface producing changes in cellular behavior (i.e., adhesion and migration) and subsequent pathological responses (i.e., the foreign body reaction and wound healing). We continue to study the foreign body reaction that occurs following biomaterial implantation by investigating secretory responses of biomaterial‐adherent macrophages and foreign body giant cells (FBGCs) as directed by material surface chemistry and further this research by determining whether secreted MMPs play a role in macrophage adhesion and fusion. We have identified numerous MMPs and their tissue inhibitors (TIMPs) in in vitro cell‐culture supernatants using antibody arrays and quantified select MMP/TIMPs with ELISAs. MMP‐9 concentrations were significantly greater than both TIMP‐1 and TIMP‐2 on all materials. The ratios of MMP‐9/TIMP‐1 and MMP‐9/TIMP‐2 increased with time because of an increase in MMP‐9 concentrations over time, while the TIMP concentrations remained constant. Total MMP‐9 concentrations in the supernatants were comparable on all materials at each timepoint, while TIMP‐1 and TIMP‐2 concentrations tended to be greater on hydrophilic/anionic surfaces. Analysis of the MMP/TIMP quantities produced per cell revealed that the hydrophilic/neutral surfaces, which inhibited macrophage adhesion, activated the adherent macrophages/FBGCs to produce a greater quantity of MMP‐9, TIMP‐1, and TIMP‐2 per cell. Pharmacological inhibition of MMP‐1,‐8,‐13, and ‐18 reduced macrophage fusion without affecting adhesion, while inhibitors of MMP‐2,‐3,‐9, and ‐12 did not affect adhesion or fusion. These findings demonstrate that material surface chemistry does modulate macrophage/FBGC‐derived MMP/TIMP secretion and implicates MMP involvement in macrophage fusion. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Effect of weight‐bearing on bone‐bonding behavior of strontium‐containing hydroxyapatite bone cement
Authors: Ni G.X. , Lu W.W. , Tang B. , Ngan A.H.W. , Chiu K.Y. , Cheung K.M.C. , Li Z.Y. , Luk K.D.K. 
Published: July 2007

AbstractThe purpose of this study was to investigate and compare the chemical composition and nanomechanical properties at the bone‐cement interface under non‐weight‐bearing and weight‐bearing conditions, in order to understand the effect of weight‐bearing on the bone‐bonding behavior of strontium‐containing hydroxyapatite (Sr‐HA) cement. In one group, Sr‐HA cement was injected into rabbit ilium (under non‐weight‐bearing conditions). Unilateral hip replacement was performed with Sr‐HA cement (under weight‐bearing conditions) in the other group. Six months later, scanning electron microscopy (SEM) with energy‐dispersive X‐ray (EDX) analysis and nanoindentation tests were conducted on the interfaces between cancellous bone and the Sr‐HA cement. The nanoindentation results revealed two different transitional behaviors under different conditions. nder weight‐bearing conditions, both the Young modulus and hardness at the interface were considerably higher than those at either the Sr‐HA cement or cancellous bone. On the contrary, under non‐weight‐bearing conditions, both the Young modulus and hardness values at the interface were lower than those at the cancellous bone, but were higher than the Sr‐HA cement. In addition, EDX results showed that the calcium and phosphorus contents at the interface under weight‐bearing conditions were considerably higher than those under non‐weight‐bearing conditions. The differences in chemical composition and nanomechanical properties at the cement‐bone interface under two different conditions indicate that weight‐bearing produces significant effects on the bone‐bonding behavior of the Sr‐HA cement. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Quantitative analysis of cell adhesion on aligned micro‐ and nanofibers
Authors: Tian Furong , Hosseinkhani Hossein , Hosseinkhani Mohsen , Khademhosseini Ali , Yokoyama Yoshiro , Estrada Giovani Gomez , Kobayashi Hisatoshi 
Published: July 2007

AbstractIn this study, we quantitatively analyzed the affinity of cell adhesion to aligned nanofibers composed of composites of poly(glycolic acid) (PGA) and collagen. Electrospun composite fibers were fabricated at various PGA/collagen weight mixing ratio (7, 18, 40, 67, and 86%) to generate fibers that ranged in diameter from 10 μm to 500 nm. Scanning electron microscopy (SEM) observation revealed that the PGA/collagen fibers were long and uniformly aligned, irrespective of the PGA/collagen weight mixing ratio. In addition, it was observed that a significantly higher number of NIH3T3 fibroblasts adhered to nanofibers with smaller diameters in comparison to fibers with larger diameters. The highest affinity of cell adhesion was observed in the PGA/collagen fibers with diameter of 500 nm and PGA/collagen weight mixing ratio of 40%. Furthermore, the adherent cells were more elongated on fibers with smaller diameters. Thus, based on the results here, PGA/collagen composite fibers are suitable for tissue culture studies and provide an attractive material for tissue engineering applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Tissue response around silicon nitride implants in rabbits
Authors: Guedes e Silva Cecilia C. , König Bruno , Carbonari Marcelo José , Yoshimoto Marcelo , Allegrini Sérgio , Bressiani José Carlos 
Published: July 2007

AbstractThe chemical and dimensional stability associated with suitable fracture toughness and propitious tribological characteristics make silicon nitride–based ceramics potential candidates for biomedical applications, mainly as orthopedic implants. Considering this combination of properties, silicon nitride components were investigated in relation to their biocompatibility. For this study, two cylindrical implants were installed in each tibia of five rabbits and were kept in the animals for 8 weeks. During the healing time, tissue tracers were administrated in the animals so as to evaluate the bone growth around the implants. Eight weeks after the surgery, the animals were euthanized and histological analyses were performed. No adverse reactions were observed close to the implant. The osteogenesis process occurred during the entire period defined by the tracers. However, this process occurred more intensely 4 weeks after the surgery. In addition, the histological analyses showed that bone growth occurred preferentially in the cortical areas. Different kinds of tissue were identified on the implant surface, characterized by lamellar bone tissue containing osteocytes and osteons, by a noncalcified matrix containing osteoblasts, or by the presence of collagen III, which may change to collagen I or remain as a fibrous tissue. The results demonstrated that silicon nitride obtained according to the procedure proposed in this research is a biocompatible material. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
The impact of sorption, buffering, and proteins on leaching of organic and inorganic substances from dental resin core material
Authors: Gregson Karen , Beiswanger A.J. , Platt Jeffrey 
Published: July 2007

AbstractDental core materials are resin‐based polymers that act as support for overlying dental restorations. Interaction with aqueous media, such as saliva in the oral cavity or serum in the pulp chamber, can cause leaching of substances from core materials. These substances can potentially have serious effects to tissues. The purpose of this study was to delineate the factors that cause leaching and to quantitate both organic and inorganic substances that leach from core materials. Two core materials and one control material were stored in distilled water, artificial saliva, buffered artificial saliva, or artificial serum for 30 days at 37°C. The materials were examined for changes in appearance and chemical composition, with a surface precipitate appearing on specimens stored in artificial saliva. The pH of the media was monitored and increased for all conditions. Organic eluants, triethyleneglycol dimethacrylate (TEGDMA), and camporquinone (CQ) were identified and measured in all media with high pressure liquid chromatography. Silicon, calcium, phosphate, and potassium were measured in the media using inductively coupled plasma optical emission spectroscopy. These results show that sorption, buffering, and the presence of proteins have an impact on the quantity of eluants that are leached from dental core materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008