bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and properties of starch acetate fibers for potential tissue engineering applications
Authors: Reddy Narendra , Yang Yiqi 
Published: March 2009

AbstractThis article reports the development of fibers from starch acetates that have mechanical properties and water stability better than most polysaccharide‐based biomaterials and protein fibers used in tissue engineering. In this research, starch acetates with three different degrees of substitution (DS) have been used to develop fibers for potential use as tissue engineering scaffolds. Varying the DS of starch acetate will provide fibers with different mechanical properties, hydrophilicity, and degradation behavior. Fibers made from DS 2.3 and 2.8 starch acetates have mechanical properties and water stability required for tissue engineering applications. The starch acetate fibers support the adhesion of fibroblasts demonstrating that the fibers would be suitable for tissue engineering and other medical applications. Biotechnol. Bioeng. 2009;103: 1016–1022. © 2009 Wiley Periodicals, Inc.
Modeling nutrient consumptions in large flow‐through bioreactors for tissue engineering
Authors: Devarapalli Mamatha , Lawrence Benjamin J. , Madihally Sundararajan V. 
Published: March 2009

AbstractFlow‐through bioreactors are utilized in tissue regeneration to ensure complete nutrient distribution and apply defined hydrodynamic stresses. The fundamental concepts in designing these bioreactors for regenerating large high aspect ratio tissues (large surface area relative to the thickness of the matrix such as skin, bladder, and cartilage) are not well defined. Further, tissue regeneration is a dynamic process where the porous characteristics change due to proliferation of cells, de novo deposition of matrix components, and degradation of the porous architecture. These changes affect the transport characteristics and there is an imminent need to understand the influence of these factors. Using computational fluid dynamic tools, changes in the pressure drop, shear stress distribution and nutrient consumption patterns during tissue regeneration were assessed in rectangular and circular reactors described by Lawrence et al. [Biotechnol Bioeng 2009;102(3):935–947]. Further, six new designs with different inlet and outlet shapes were analyzed. The fluid flow was defined by the Brinkman equation on the porous regions using the pore characteristics of 85 µm and 120 pores/mm2. The minimum flow requirements to satisfy nutrient (oxygen and glucose) requirements for three different cell types (SMCs, chondrocytes, and hepatocytes) was evaluated using convective diffusion equation. For consumption reaction, the Michaelis–Menten rate law was used, with constants (km and vm values) extracted from literature. Simulations were performed by varying the flow rate as well as the cell number. One of the circular reactors with semicircular inlet and outlet shape decreased (i) non‐uniformity in hydrodynamic stress within the porous structure and (ii) non‐uniform nutrient distribution. All cell types showed increased consumption of oxygen than glucose. Hepatocytes needed a very high flow rate relative to other cell types. Increase in cell number suggested a need for increasing the flow in circular reactors. Biotechnol. Bioeng. 2009;103: 1003–1015. © 2009 Wiley Periodicals, Inc.
Liquid chromatography–tandem mass spectrometry method of loxoprofen in human plasma
Authors: Lee Hye Won , Ji Hye Young , Sohn Dong Hwan , Kim Se‐Mi , Lee Yong Bok , Lee Hye Suk 
Published: March 2009

AbstractA rapid, sensitive and selective liquid chromatography–electrospray ionization mass spectrometric method for the determination of loxoprofen in human plasma was developed. Loxoprofen and ketoprofen (internal standard) were extracted from 20 µL of human plasma sample using ethyl acetate at acidic pH and analyzed on an Atlantis dC18 column with the mobile phase of methanol:water (75:25, v/v). The analytes were quantified in the selected reaction monitoring mode. The standard curve was linear over the concentration range of 0.1–20 µg/mL with a lower limit of quantification of 0.1 µg/mL. The coefficient of variation and relative error for intra‐ and inter‐assay at four quality control levels were 2.8–5.2 and 4.8–7.0%, respectively. The recoveries of loxoprofen and ketoprofen were 69.7 and 67.6%, respectively. The matrix effects for loxoprofen and ketoprofen were practically absent. This method was successfully applied to the pharmacokinetic study of loxoprofen in humans. Copyright © 2009 John Wiley & Sons, Ltd.
Prediction of drug bioavailability in humans using immobilized artificial membrane phosphatidylcholine column chromatography andin vitrohepatic metabolic clearance
Authors: Shin Beom Soo , Yoon Chi Ho , Balthasar Joseph P. , Choi Bu Young , Hong Seok Hyun , Kim Hyoung Jun , Lee Jong Bong , Hwang Sang Wook , Yoo Sun Dong 
Published: March 2009

AbstractThis study reports a rapid screening method for the prediction of oral drug bioavailability in humans based on combined immobilized artificial membrane (IAM) chromatographic capacity factor (kIAM) andin vitrostability in hepatic microsomes. The fraction of drug absorbed (Fa) in humans was predicted for a set of 15 structurally diverse commercial drugs based onkIAMvalues using a mobile phase consisting of acetonitrile: Dulbecco's phosphate‐buffered saline. The hepatic intrinsic clearance (CL) was calculated fromin vitrodisappearance half‐life, and the oral bioavailability was predicted usingin vitrohepatic clearance (CLh) andFa. Significant correlations were observed for the relationships between predicted hepatic extraction ratios (ERh) and actual presystemic metabolism (r= 0.854) and between predicted and observed oral bioavailabilities (r= 0.805;p< 0.01). The IAM capacity factor together with the hepatic microsomal disappearance half‐life may be useful in identifying compounds with high oral absorption potential in early drug discovery processes. Copyright © 2009 John Wiley & Sons, Ltd.
Wavelet based signal analysis in three phase circuits using neural network
Authors: Suja S. , Jerome Jovitha 
Published: March 2009

AbstractThis article proposes the use of wavelet based neural network in recognizing the harmonics. The discrete wavelet transforms is used in calculating the effective values of three phase active and reactive power. The discrete wavelet transforms with probabilistic neural network (PNN) model is used in constructing the classifier of harmonics. There are four stages in identification of harmonics. First stage is simulation of a three phase inverter circuit. The second stage is the conversion of the three phase current and voltage by PQ theory into alpha–beta reference frame. The third stage is that these alpha–beta vectors are subjected to multi resolution analysis. The signals are then decomposed by discrete wavelet transform (DWT) at six levels. The final stage is that the coefficients generated are used in the calculation of active, reactive power and energy. The DWT coefficients are used in identifying the harmonics using PNN. The main advantage in this analysis is that the active and reactive power calculated is done at various frequency bands. This covers the harmonic power at various frequencies. Wavelet is used in this article since they can detect and locate the disturbance accurately. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 537–546, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20223
Web‐based application for descriptive geometry learning
Authors: Rubio L. , Muñoz‐Abella B. , Castejón C. , Muñoz‐Sánchez A. 
Published: March 2009

AbstractIn the education of basic matters of technical studies, as representation systems, it is necessary to introduce new technologies that allow individual learning to students. Learning can be traditional face to face or remotely by means of e‐learning. In this work, a web‐based computer specific application to study the Monge Projection is presented. The web site is design to have two different parts: the theoretical tutorials to remind the most important concepts of the subject, and some step by step solved exercises with indications, in order to fix the main ideas of the subject in the students mind. Likewise, and for a better comprehension, the students have the possibility, once finished the exercise, to visualize the three‐dimensional solution of the two‐dimensional problem. This application is initially thought to support the master classes, but it is also valid for distance learning, where students face alone the learning. This type of applications allows bringing basic matters closer to the students by the use of new technologies. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 574–581, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20244
Membrane‐Aerated Biofilm Reactor Behaviors for the Treatment of High‐Strength Ammonium Industrial Wastewater
Authors: Cao C. , Zhao L. , Xu D. , Geng Q. 
Published: March 2009

AbstractA single‐tube membrane‐aerated biofilm reactor (MABR) was used to investigate the effect of the reaction time, reaction temperature, pH value, C/N ratio, and sludge concentration on the removal rates of the NOx–‐N and COD in high‐strength ammonium industrial water by supplying oxygen during the batch experiment. The homogeneous mathematical model is developed to predict their transient responses using Monod kinetics with dual substrate limitation. The model incorporates mass transport by convection and diffusion in the surrounding liquid contained inside the interconnected pores and channels within the biofilm. Transport and kinetic parameters are estimated from experiments and the model successfully predicts concentration measurements in some of the sets of experiments.
Sensing Abilities of Crown Ether Functionalized Polythiophenes
Authors: Casanovas Jordi , Preat Julien , Zanuy David , Alemán Carlos 
Published: March 2009

AbstractTuning sensing abilities! The affinity of three different [15]crown‐5 ether functionalized polythiophenes for alkali ions has been explored (see figure). Ab initio and DFT quantum mechanical calculations show that the binding energy between neutral conducting polymers and metallic ions, which interact attractively, decreases as the size of the ion increases. Oxidation of these polythiophene derivatives significantly reduces their affinity towards alkali ions, becoming low or even nonexistent.magnified imageThis work reports a theoretical study of the affinity of three different [15]crown‐5 ether functionalized polythiophenes for alkali ions. Ab initio and DFT quantum mechanical calculations have evidenced that the binding energy between neutral conducting polymers and metallic ions, which interact attractively, decreases as the size of the ion increases. However, the preferences of these polythiophene derivatives have been found to be influenced by the entropic contribution, which favors binding with Na+ in preference to Li+. Molecular dynamics simulations have shown that this behavior can be accounted for on the basis of the large fluctuations that Li+ undergoes when it is contained in the cavity of the [15]crown‐5 ether macrocycle. In contrast, the fluctuations detected for complexes with Na+ and K+ were particularly low, even though only the former ion fits into the center of the macrocyclic cavity. Oxidation of these polythiophene derivatives produces a drastic change in their sensing abilities, their affinities towards alkali ions becoming low or even nonexistent. Moreover, calculations indicate that the presence of unsubstituted thiophene rings directly attached to a functionalized thiophene modulates the strength of the binding in the oxidized state by reducing the repulsive interaction between the metallic cation and the π‐conjugated system. On the other hand, the influence of alkali ions on the electronic properties, in particular, on the ionization potentials and the lowest π–π* transitions, of both the neutral and oxidized polythiophenes is discussed.
A First Total Synthesis of Ganglioside HLG‐2
Authors: Iwayama Yuki , Ando Hiromune , Ishida Hideharu , Kiso Makoto 
Published: March 2009

AbstractA neuritegenic ganglioside from sea cucumber, HLG‐2 (see figure), has been synthesized for the first time. The unique tandem of sialic acids, Neu5Gc‐α(2,4)‐NeuAc, was established by the combination of a reactive N‐Troc sialyl donor and a 1,5‐lactamized sialyl acceptor. The ceramide counterpart was assembled in a stereoselective manner. Direct connection of the trisaccharide and the ceramide successfully afforded a precursor of HLG‐2, which was converted to ganglioside HLG‐2 in pure form.magnified imageA first synthesis of the neuritegenic ganglioside HLG‐2, which was identified in extracts of the sea cucumber Holothuria leucospilota, is described. The characteristic sequence of the trisaccharide part, α‐N‐glycolylsialyl‐(2,4)‐α‐N‐acetylsialyl‐(2,6)‐glucoside, was efficiently assembled by coupling of a highly active N‐2,2,2‐trichloroethoxycarbonyl (Troc)‐protected sialyl donor and a 1,5‐lactamized sialyl acceptor with high stereoselectivity. The corresponding trisaccharyl imidate donor was directly glycosidated with the primary hydroxyl group of the ceramide part, producing protected HLG‐2 in relatively high yield, global deprotection of which furnished ganglioside HLG‐2 in highly pure form.
The Search for the Mechanism of the Reaction Catalyzed by Farnesyltransferase
Authors: Sousa Sérgio Filipe , Fernandes Pedro Alexandrino , Ramos Maria João 
Published: March 2009

AbstractAtomic‐level portrait: The mechanism of the reaction catalyzed by the puzzling enzyme farnesyltransferase is elucidated by using computational methods, allowing the obtainment of the first real detailed atomistic quantum‐chemical transition‐state structure (see figure) for the reaction catalyzed by this enzyme. The results obtained provide an atomic‐level framework for the design of more potent and specific inhibitors for this important enzyme.magnified image
Structural replacement or structural inducement: government ties of Chinese business executives
Authors: Yao Xiaotao , Li Stan Xiao , Sue‐Chan Christina , Xi Youmin 
Published: March 2009

AbstractWe suggest that the structural replacement thesis, which proposes that managers in Chinese nonstate‐owned enterprises (NSOEs) possess more government ties than managers in Chinese state‐owned enterprises (SOEs), is theoretically incomplete because it considers only the motivation of managers of NSOEs. The extensiveness of social ties is influenced also by the capability and opportunity for social actors to cultivate these social ties. We introduce the structural inducement thesis, which holds that SOE managers have more government ties than do NSOE managers, as an alternative to the structural replacement thesis. Our analysis of 250 Chinese managers' ties supports this structural inducement thesis. The theoretical and applied implications of these findings are discussed. Copyright © 2009 ASAC. Published by John Wiley & Sons, Ltd.
Exploring a non‐dimensional varying exponent equation relating minimum spouting velocity to maximum spoutable bed depth
Authors: Du Wei , Bi Xiaotao , Epstein Norman 
Published: March 2009

AbstractThe equation $U_{{\rm ms}} /U_{{\rm mf}} = (H/H_{\rm m} )^{1 - (0.5\,H/H_{\rm m} )}$ was critically examined for spouting both in small conical‐cylindrical columns (Dc < 0.5 m) and large cone‐base or flat‐bottom cylindrical columns (Dc ≥ 0.5 m). For small columns, a data base of 36 points with experimental measurements of both Hm and Um(=Ums at H = Hm) afforded some insights into the components of this equation and to the merits of the equation itself. For large columns, in the absence of verifiable methods of predicting Hm, correlation of Ums/Umf as a function of H/Hm, using the available experimental data on Ums, has not been achieved.
CFD modelling of a semi‐cylindrical spouted bed: Numerical simulation and experimental verification
Authors: Béttega Rodrigo , de Almeida André Ricardo Felkl , Corrêa Ronaldo Guimarães , Freire José Teixeira 
Published: March 2009

AbstractIt is well known that a special attention is necessary to infer process information of a spouted bed at full‐column using data from semi‐cylindrical vessels. In this work experimental data are obtained from a semi‐cylindrical spouted bed for comparison with CFD simulations performed using a 3D simulation scheme. The purpose of this paper is to contribute on the discussing about the influence of the flat wall in the solid behaviour inside the semi‐cylindrical vessel by comparing numerical results with experimental data. Simulated results of fountain height, spout diameter and particle velocities inside the bed are compared with image data obtained from a semi‐cylindrical column. The simulations were accomplished using the commercial package FLUENT 6.3.26.
Drying of herbal extract in a draft‐tube spouted bed
Authors: Souza C.R.F. , Oliveira W.P. 
Published: March 2009

AbstractThis work evaluates the feasibility of the draft‐tube spouted bed for drying of herbal extract. Drying runs were carried out according to a central composite design in a conical–cylindrical draft‐tube spouted bed. The variables studied were the percentage of the drying aid (ADJ), the drying gas flow rate relative to gas flow at minimum spouting (Q/Qms), and the flow rate of extract fed to the system relative to the spouting gas flow rate (Ws/Wg). Colloidal silicon dioxide was the drying aid used in order to improve drying performance. Statistical analysis of the effects of processing parameters on product recovery, product accumulation in the bed, and product properties permitted the identification of parameters presenting significant effects on drying. Optimized drying conditions were related to experimental parameters as follow: high levels of the percentage of drying adjuvant (ADJ), high airflow rate relative to minimum spouting (Q/Qms), and low values of the feed flow rate of the extract relative to the gas flow rate (Ws/Wg).
The Impact of Aspirin Resistance on the Long‐term Cardiovascular Mortality in Patients with Non‐ST Segment Elevation Acute Coronary Syndromes
Authors: Foussas Stefanos G. , Zairis Michael N. , Tsirimpis Vasilios G. , Makrygiannis Stamatis S. , Patsourakos Nikolaos G. , Adamopoulou Evdokia N. , Mytas Demetrios Z. , Prekates Athanasios A. , Perdiou Anna J. , Tsoukanas Vasilios K. , Argyrakis Spyros K. 
Published: March 2009

AbstractBackgroundAspirin resistance has been associated with an adverse long‐term outcome in patients with atherosclerotic coronary artery disease, but more studies are needed.HypothesisThe aim of this study was to investigate the impact of aspirin resistance, assessed by the Platelet Function Analyzer‐100 (PFA‐100) (Dade Behring Inc., Deerfield, Ill., USA) on the long‐term prognosis in patients with non‐ST segment elevation acute coronary syndromes (NSTE‐ACS).MethodsA total of 496 consecutive patients were studied. The 1‐y incidence of cardiovascular death was the prespecified study endpoint. The patients were divided, according to the values of PFA‐100 collagen epinephrine closure time (CEPI‐CT) upon presentation, into aspirin sensitives (those with a PFA‐100 CEPI‐CT > 193 sec) and aspirin resistants (those with a PFA‐100 CEPI‐CT ≤ 193 sec).ResultsAspirin resistants were younger (p‐value = 0.04), and less frequently hypertensives (p‐value = 0.05) or diabetics (p‐value = 0.04) than aspirin sensitives. By 1 y, the incidence of cardiovascular deaths in the entire cohort was 12.9% (64/496), and aspirin resistants were at significantly higher risk of cardiovascular death (23.1% versus 9.6%; hazard ratio [HR] = 2.6; 95% confidence interval [CI] = 1.6–4.3; p‐value < 0.001), than aspirin sensitives. By multivariate Cox regression analysis, aspirin resistance (a PFA‐100 CEPI‐CT ≤ 193 sec) was among the most potent predictors of the 1‐y incidence of cardiovascular death (HR = 2.8; 95% CI = 1.7–4.6; p‐value < 0.001).ConclusionAccording to the present data, aspirin resistance, assessed by the PFA‐100, is an independent predictor of long‐term cardiovascular mortality in patients with NSTE‐ACS. Copyright © 2009 Wiley Periodicals, Inc.
QPV Interval as a Measure of Arterial Stiffness in Women with Systemic Lupus Erythematosus
Authors: Qureshi Ghazanfar , Salciccioli Louis , Lee Susan , Qureshi Mohammad , Kapoor Amit , Ginzler Ellen , Lazar Jason M. 
Published: March 2009

AbstractBackgroundSystemic lupus erythematosus (SLE) is associated with premature atherosclerosis and increased arterial stiffness. The QPV interval has been proposed as a measure of arterial stiffness. The QPV interval is based on the premise that transit time from cardiac ejection to brachial artery flow is shortened in patients with increased arterial stiffness.HypothesisThe objective of this study was to determine the significance of the QPV interval as a measure of arterial stiffness in patients with SLE.MethodsWe prospectively studied 46 female SLE patients. The QPV interval was calculated as the time from onset of the QRS complex to peak flow velocity of the brachial artery during ultrasound examination. Measurements of arterial stiffness: augmentation index (AI) and pulse wave velocity (PWV) were obtained by applanation tonometry while patients were on a stable medical regimen.ResultsMean age was 44 ± 14 y and mean QPV interval was 198 ± 18 msec QPV interval correlated inversely with age (r = − 0.39, p = 0.008), AI (r = − 0.41, p = 0.004), PWV (r = − 0.39, p = 0.007), and aortic pulse pressure (PP) (r = − 0.45, p = 0.002). On multivariate regression analysis, QPV interval was found to be an independent predictor of PWV after adjusting for age (R2 = 0.26, p < 0.001).ConclusionIn women with SLE, QPV decreases with age and is inversely related with measures of arterial stiffness. QPV may be useful in identifying SLE patients with higher arterial stiffness in the clinical or research setting. Further larger studies are needed to confirm these preliminary results. Copyright © 2009 Wiley Periodicals, Inc.
Clinical Diagnosis of Posttraumatic Stress Disorder After Myocardial Infarction
Authors: Guler Erika , Schmid Jean‐Paul , Wiedemar Lina , Saner Hugo , Schnyder Ulrich , Känel Roland von 
Published: March 2009

AbstractBackgroundClinician‐rated large‐scale studies estimating the prevalence of posttraumatic stress disorder (PTSD) related to myocardial infarction (MI) and identifying predictors of clinical PTSD are currently lacking.HypothesesWe hypothesized that PTSD is prevalent in post‐MI patients and that the subjective experience of the MI determines PTSD status.MethodsWe approached 951 post‐MI patients with a questionnaire screening for PTSD symptoms related to their MI. Those responding and meeting a cutoff of PTSD symptom levels were invited to participate in a structured clinical interview to diagnose PTSD following Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV) criteria. Fear of dying, feelings of helplessness, and severity of pain perceived during the MI were also assessed by visual analog scales.ResultsThe screening questionnaire was completed by 394 patients, whereby 77 met the cutoff for the interview (8 patients declined the interview). Forty of 394 patients (10.2%) had clinical PTSD (subsyndromal and syndromal forms combined). Younger age (OR 0.95, 95% CI 0.91–0.99), greater fear of dying (OR 2.77, 95% CI 1.28–5.97), and more intense feelings of helplessness (OR 2.97, 95% CI 1.42–6.21) were independent predictors of PTSD status. Perceived pain intensity during MI, sex, type of index MI, left ventricular ejection fraction, number of coronary occlusions, and highest level of total creatinine kinase were not significant predictors.ConclusionsClinical PTSD is prevalent in post‐MI patients. Demographic and particularly psychological variables related to the subjective experience of the event were stronger predictors of PTSD status than were objective measures of MI severity. Copyright © 2009 Wiley Periodicals, Inc.