bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability in Dental Changes in RME and SARME: A 2-Year Follow-up
Authors: Sokucu Oral , Kosger H. Huseyin , Bıcakci A. Altug , Babacan Hasan
Published: September 2008

Objective: To compare the effects of rapid maxillary expansion (RME) and surgically assisted rapid maxillary expansion (SARME) on dentoalveolar structures following orthodontic treatment, as well as stability at 2-year follow-up.

Materials and Methods: Two groups of subjects were used in the study. Group 1 consisted of 14 subjects (mean age, 12.7 ± 1.4 years) who were treated with RME, and Group 2 consisted of 13 subjects (mean age, 18.5 ± 2.3 years) who were treated with SARME. In both groups, all cases had a maxillary width deficiency with bilateral crossbites. Maxillary dental casts were available at three different intervals: pretreatment (T1), after orthodontic treatment (T2), and at follow-up recall (T3). Intermolar and interpremolar width, palatal height, and maxillary arch depth and length were assessed from maxillary dental casts.

Results: Treatment by RME and SARME produced significant increases in intermolar and interpremolar width and maxillary arch length after expansion (T2) (P < .05). The amount of relapse was not significantly different 2 years after treatment (P > .05).

Conclusions: Although age ranges of the patient groups are different, the dentoalveolar responses of RME and SARME were similar after orthodontic treatment. (Angle Orthod. 2009:79; )
Chromium Release from New Stainless Steel, Recycled and Nickel-free Orthodontic Brackets
Authors: Sfondrini Maria Francesca , Cacciafesta Vittorio , Maffia Elena , Massironi Sarah , Scribante Andrea , Alberti Giancarla , Biesuz Raffaela , Klersy Catherine
Published: September 2008

Objective: To test the hypothesis that there is no difference in the amounts of chromium released from new stainless steel brackets, recycled stainless steel brackets, and nickel-free (Ni-free) orthodontic brackets.

Materials and Methods: This in vitro study was performed using a classic batch procedure by immersion of the samples in artificial saliva at various acidities (pH 4.2, 6.5, and 7.6) over an extended time interval (t1 = 0.25 h, t2 = 1 h, t3 = 24 h, t4 = 48 h, t5 = 120 h). The amount of chromium release was determined using an atomic absorption spectrophotometer and an inductively coupled plasma atomic emission spectrometer. Statistical analysis included a linear regression model for repeated measures, with calculation of Huber-White robust standard errors to account for intrabracket correlation of data. For post hoc comparisons the Bonferroni correction was applied.

Results: The greatest amount of chromium was released from new stainless steel brackets (0.52 ± 1.083 μg/g), whereas the recycled brackets released 0.27 ± 0.38 μg/g. The smallest release was measured with Ni-free brackets (0.21 ± 0.51 μg/g). The difference between recycled brackets and Ni-free brackets was not statistically significant (P = .13). For all brackets, the greatest release (P = .000) was measured at pH 4.2, and a significant increase was reported between all time intervals (P < .002).

Conclusion: The hypothesis is rejected, but the amount of chromium released in all test solutions was well below the daily dietary intake level.
Marfan Syndrome—An Orthodontic Perspective
Authors: Utreja Achint , Evans Carla A.
Published: September 2008

Marfan syndrome is a heritable disorder of connective tissue that can affect the heart, blood vessels, lungs, eyes, bones, and ligaments. It is characterized by tall stature, elongated extremities, scoliosis, and a protruded or caved-in breastbone. Patients typically have a long, narrow face. A high-arched palate produced by a narrow maxilla and skeletal Class II malocclusion due to mandibular retrognathia are other common features. For a patient with no family history of the disorder, at least three body systems must be affected before a diagnosis can be made. Individuals affected by the syndrome routinely seek orthodontic treatment to correct the orofacial manifestations. In this report, the authors present the records of three patients with Marfan syndrome who were treated at a dental school. Two patients had severe periodontal disease in the absence of significant contributing local factors. The presentation of systemic symptoms and typical physical characteristics varied. The syndrome thus went unnoticed in one patient for many years. We discuss here the observed intraoral findings and the progress of orthodontic treatment to provide a brief overview of the challenges involved in treating such patients.
Orthodontic Treatment Including Autotransplantation of a Mature Tooth
Authors: Nishimura Kazuaki , Amano Shinobu , Nakao Kimihisa , Goto Shigemi
Published: September 2008

The patient was a 24-year-old Japanese female. The chief complaints were crowding and masticatory dysfunction due to the missing right first molar. Her maxillary first premolars had been extracted when she was a primary school student. We planned orthodontic treatment with extraction of the mandibular first premolars and transplantation of the mandibular left first premolar into the maxillary right first molar area. We made a diagnostic setup model to initiate an appropriate treatment plan for the discrepancy in tooth size ratio. Following the diagnostic setup model, the space in the maxillary right first molar area was closed by a small amount of tooth movement, and a good occlusion was achieved. The patient had been in retention for 7 years, and the occlusion has been maintained very well during this time. In the follow-up, 10 years after autotransplantation, no signs of inflammatory or replacement root resorption were found, and marginal bone support appeared similar to that of neighboring teeth.
Comparative Philosophy and the Liberal Arts: Between and Beyond—Educating to Cultivate Geocitizens
Authors: McCarthy Erin
Published: September 2008

Abstract:

In this paper, I critically engage the meaning of creating multicultural, diverse communities on Liberal Arts campuses through comparative philosophy with a feminist orientation, speaking to theory on undergraduate liberal arts education, my own research and teaching. In Teaching to Transgress: Education as the Practice of Freedom, bell hooks remarks that the “call for a recognition of cultural diversity, a rethinking of ways of knowing, a deconstruction of old epistemologies, and the concomitant demand that there be a transformation in our classrooms, in how we teach and what we teach, has been a necessary revolution—one that seeks to restore life to a corrupt and dying academy” (29–30). Teaching comparative philosophy can be pivotal in this revitalization of the academy and can also contribute to one of the fundamental goals of education in the liberal arts in particular—that of educating world citizens or “geocitizens,” who are prepared to make significant contributions to the multicultural world we live in. I draw on Japanese philosophy, through Watsuji Tetsuro in particular, and on Luce Irigaray's feminist philosophy as well as on current scholarship in liberal arts education to suggest that comparative philosophy can play a pivotal role in fostering the development of ethical geocitizens.
Model-based Design of Clinical Information Systems
Authors: Werner J. , Lee Y. , Malin B. , Ledeczi A. , Mathe J.
Published: September 2008

Objective: The goal of this research is to provide a framework to enable the model-based development, simulation, and deployment of clinical information system prototypes with mechanisms that enforce security and privacy policies.

Methods:
We developed the Model-Integrated Clinical Information System (MICIS), a software toolkit that is based on model-based design techniques and highlevel modeling abstractions to represent complex clinical workflows in a service-oriented architecture paradigm. MICIS translates models into executable constructs, such as web service descriptions, business process execution language procedures, and deployment instructions. MICIS models are enriched with formal security and privacy specifications, which are enforced within the execution environment.

Results:
We successfully validated our design platform by modeling multiple clinical workflows and deploying them onto the execution platform.

Conclusions:
The model-based approach shows great promise for developing, simulating, and evolving clinical information systems with formal properties and policy restrictions.
Model-based Security Analysis of the German Health Card Architecture
Authors: Rumm R. , Jürjens J.
Published: September 2008

Objectives:
Health-care information systems are particularly security-critical. In order to make these applications secure, the security analysis has to be an integral part of the system design and IT management process for such systems.

Methods:
This work presents the experiences and results from the security analysis of the system architecture of the German Health Card, by making use of an approach to model-based security engineering that is based on the UML extension UMLsec. The focus lies on the security mechanisms and security policies of the smart-card-based architecture which were analyzed using the UMLsec method and tools.

Results:
Main results of the paper include a report on the employment of the UMLsec method in an industrial health information systems context as well as indications of its benefits and limitations. In particular, two potential security weaknesses were detected and countermeasures discussed.

Conclusions:
The results indicate that it can be feasible to apply a model-based security analysis using UMLsec to an industrial health information system like the German Health Card architecture, and that doing so can have concrete benefits (such as discovering potential weaknesses, and an increased confidence that no further vulnerabilities of the kind that were considered are present).
Do Tour Boats Affect Fur Seals at Montague Island, New South Wales?
Authors: Shaughnessy Peter D. , Nicholls Anthony O. , Briggs Sue V.
Published: September 2008

Interactions between fur seals (Arctocephalus pusillus doriferus and A. forsteri) and tour boats at Montague Island were investigated between November 1997 and November 1998. The fur seals were in four haul-out sites, which are referred to here as colonies. The study was
instigated by the management requirement of the National Parks and Wildlife Service of New South Wales to determine effects of disturbance from tour boats on the fur seal colonies. At each of 84 inspections, distance between the boat and the colony was measured and seal behavior (or response)
was recorded 11 times at 15-second intervals as the boat moved toward the seals. This period of 2.5 minutes was approximately the time tour boats stayed at a colony. Behavior of the fur seals ashore was recorded in four categories of increasing disturbance from "Resting" to "Many moving."
From analyses using multinomial models, the probability of observing a given response by the fur seals and the pattern of the responses as a function of distance from the colony were both influenced by the colony under observation. In general, fur seals' responses were significantly correlated
with distance between the study boat and the colony, and with the size of the colony (i.e., number of fur seals visible ashore). In all cases, the probability of the colony remaining in the "Resting" category decreased as the distance between the colony and the study boat decreased. Similarly
the probability of the colony showing the maximum response ("Many moving") increased as the distance decreased. The probability of New Zealand fur seals "Resting" was higher than for Australian fur seals. Tour boats approaching the colonies had a relatively small effect on the fur seals; few
or none of them ran to the sea. Based on results from this study, we recommended that the minimum approach distance of tour boats to the fur seal colonies at Montague Island should be 40 m; other recommendations involved how tour boats approach the fur seal colonies. The former has been gazetted
as a government regulation and the other recommendations have been incorporated into the license conditions for the tour boats operators.
Understanding Motivations and Expectations of Scuba Divers
Authors: Meisel-Lusby Carolin , Cottrell Stuart
Published: September 2008

This study examines scuba divers as a vital segment of the marine tourism market. To better understand scuba divers, motivation, expectations, and expectation outcomes were measured. A survey including 28 motivation statements adapted from the recreation experience preference scales
was administered to 300 divers diving with different dive operators in the Florida Keys in summer 2002. Eighteen expectation variables with outcome statements were measured in a pre- and posttest format (expectations before the trip and outcomes after the dive trip). Nonparametric tests revealed
differences between divers of different levels of development (i.e., beginning, intermediate, advanced, expert, postexpert). Beginners dove for the challenge and excitement while advanced divers dove to be with similar people, use equipment, and see shipwrecks. Findings show differences between
Boy Scouts in a youth adventure program and divers (domestic and international) diving with a regular dive shop. Scouts dove for adventure and excitement. Scouts showed the highest scores in postevent expectation variables. Implications for dive operations to improve diver preparations are
given.
The Effectiveness of an Established Sanctuary Zone for Reducing Human Disturbance to Australian Sea Lions (Neophoca Cinerea) at Carnac Island, Western Australia
Authors: Kent Chandra Salgado P. , Crabtree Brett
Published: September 2008

This study tested the effectiveness of a recently established sanctuary zone on Carnac Island (Western Australia) in reducing human disturbances to Australian sea lions (Neophoca cinerea). Several methods of recording behaviors were also tested to clarify their adequacy for detecting
human disturbances. Observations made between March 2005 and September 2006 (98 observations over 16 days) indicated that a wireless camera was effective for monitoring sea lions unobtrusively, and continuous and instantaneous observations were both generally effective in monitoring levels
of human disturbance. The sanctuary zone was ineffective in that sea lions hauled out more often in the adjacent recreational zone, even though the sanctuary was established based on previous observations. This study concluded that sea lions are more likely to haul out where environmental
attributes along a beach are suitable. Because environmental conditions are variable over time, a fixed sanctuary zone will only aid in reducing impacts when conditions are suitable in that zone. The authors recommend that future sanctuaries should include entire stretches of useable beach
to be effective.
Fuel Cell Membrane Electrode Assemblies Fabricated by Layer‐by‐Layer Electrostatic Self‐Assembly Techniques
Authors: Taylor André D. , Michel Marc , Sekol Ryan C. , Kizuka Jeremy M. , Kotov Nicholas A. , Thompson Levi T.
Published: September 2008

High activity, carbon supported Pt electrocatalysts were synthesized using a supercritical fluid method and a selective heterogeneous nucleation reaction to disperse Pt onto single walled carbon nanotube and carbon fiber supports. These nanocomposite materials were then incorporated into catalyst and gas diffusion layers consisting of polyelectrolytes, i.e., Nafion, polyaniline, and polyethyleneimine using layer‐by‐layer (LBL) assembly techniques. Due to the ultrathin nature and excellent homogeneity characteristics of LBL materials, the LBL nanocomposite catalyst layers (LNCLs) yielded much higher Pt utilizations, 3,198 mW mgPt−1, than membrane electrode assemblies produced using conventional methods (∼800 mW mgPt−1). Thinner membranes (100 bilayers) can further improve the performance of the LNCLs and these layers can function as catalyzed gas diffusion layers for the anode and cathode of a polymer electrolyte membrane fuel cell.
Conversion of Propargylic Alcohols to β‐Oxo Esters Catalyzed by Novel Ruthenium‐Phosphoramidite Complexes
Authors: Costin Stephen , Rath Nigam P. , Bauer Eike B.
Published: September 2008

A series of half‐sandwich phosphoramidite complexes of ruthenium were synthesized and employed as catalysts in the atom‐economical formation of β‐oxo esters from carboxylic acids and propargylic alcohols. Reaction of the phosphoramidites (R)‐BINOL‐PNR2 (R=Me, 1a; i‐Pr, 1b; benzyl, 1c) and (rac)‐6,6′‐dibromo‐BINOL‐PNMe2 (1d) with the dimeric p‐cymene‐ruthenium dichloride complex, [RuCl2(p‐cymene)]2, gave the complexes [RuCl2(p‐cymene)(L)] (L=1a, 7a; 1b, 7b; 1c, 7c; 1d, 7d) in 96–66% yield. Accordingly, reaction of (R)‐BINOL(8H)‐PNMe2 (2a) and (R)‐BINOL(8H)‐PN(benzyl)2 (2b) with [RuCl2(p‐cymene)]2 afforded the complexes [RuCl2(p‐cymene)(L)] (L=2a, 8a; 2b, 8b) in 82% and 86% yield. In a similar reaction, treatment of (R)‐BIPHEN‐PNMe2 (9) with [RuCl2(p‐cymene)]2 gave the complex [RuCl2(p‐cymene)(9)] (11) in 60% yield. Finally, phosphoramidite 1b reacted with [RuCl2(C6Me6)]2 to give [RuCl2(C6Me6)(1b)] (12) in 78% yield. All novel complexes are catalytically active in the formation of β‐oxo esters from propargylic alcohols and carboxylic acids. Standard conditions involve cyclohexane solvent, propargylic alcohol (1.0 equiv.), carboxylic acid (1.0 equiv.), ruthenium catalyst (1.5 mol%), and 90 °C for 5–18 h. Isolated yields of the β‐oxo esters range from 87 to 16% and show broad substrate generality. The reaction proceeds without racemization if a chiral propargylic alcohol is employed. The method is practical as no additives are required and the exclusion of oxygen and moisture is not needed. Complex 7c turned out to be the most effective catalyst (5 h reaction time), showing that the ligand structure has a profound impact on the catalytic performance. The crystal structure of 7a was determined, confirming an octahedral coordination geometry about the ruthenium center.
Exploring Structural Diversity in Ligand Design: The Aminoindanol Case
Authors: Rodríguez‐Escrich Sergi , Solà Lluís , Jimeno Ciril , Rodríguez‐Escrich Carles , Pericàs Miquel A.
Published: September 2008

A series of enantiopure ligands based on the aminoindanol scaffold, but differing in regio‐ and stereochemistry has been synthesized. These ligands have been conveniently derivatized and their catalytic efficiency in different enantioselective reactions has been screened to determine privileged candidates with respect to regio‐ and stereochemistry for each considered process. The nature of the amino substituent has been optimized for specific applications and this has led to the development of an efficient method for the preparation of bulky bicyclic amines by reductive amination.
A Direct Palladium‐Catalyzed Route to Selectively Substituted Carbazoles through Sequential CC and CN Bond Formation: Synthesis of Carbazomycin A
Authors: Ca' Nicola Della , Sassi Giovanni , Catellani Marta
Published: September 2008

The present paper offers a synthetically simple one‐pot procedure for the catalytic preparation of the biologically interesting class of carbazoles. The new procedure is based on the combined catalysis of palladium and norbornene starting from o‐substituted iodoarenes and N‐sulfonylated or N‐acetylated o‐bromoanilines. A well‐known member of this class, carbazomycin A, has been successfully prepared.
Reaction rate constant of CO2 hydrate formation and verification of old premises pertaining to hydrate growth kinetics
Authors: Bergeron Sebastien , Servio Phillip
Published: September 2008

Experimental data on the rate of carbon dioxide hydrate formation in a semibatch stirred‐tank reactor was obtained using a particle‐size analyzer capable of detecting particles as small as 0.6 nanometers in a closed‐loop system. Experiments were carried out at temperatures between 275.3 and 279.4 K and pressures ranging from 2,014 to 3,047 kPa. The reaction rate constant of CO2 hydrate formation was determined using a newly developed kinetic model independent of the dissolution rate at the vapor‐liquid water interface. The average reaction rate constant determined experimentally was found to increase with temperature following an Arrhenius‐type relationship, from 1.8 × 10−8 m/s to 1.8 × 10−7 m/s, over the 4‐degree range investigated. Similarly, the reaction rate constant calculated from a population balance varied from 1.4 × 10−8 m/s to 1.7 × 10−7 m/s over the same temperature interval. The initial number of hydrate particles was calculated using the mole fraction of the gas hydrate former in the bulk‐liquid phase at the onset of hydrate growth rather than the equilibrium solubility. The cumulative relative scattering was also compared to the derived count rate to determine whether or not the number of hydrate particles remained constant during the hydrate growth experiment. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Modeling ice removal in fluidized‐bed freeze concentration of apple juice
Authors: Nazir S. , Farid M.M.
Published: September 2008

Stable operation of fluidized‐bed heat exchangers during freeze concentration is limited by the rate of ice removal from the cooling surfaces. Operation remains stable as long as the erosion rate caused by the fluidized particles is equal or greater then the ice growth rate. An empirical model has been devised to estimate the erosion rate at different operating conditions. 4 and 5 mm equilateral cylindrical particles made of stainless steel (SS304) were fluidized in the inside pipe of a vertical double pipe heat exchanger. Bed porosities of 0.94–0.76, and apple juice concentrations of 12, 16, 18, and 20 Brix were tested. The new erosion model was developed based on an analogy between erosion and heat‐transfer phenomenon. Experimental values of erosion rate were obtained for different operating conditions and compared with the values estimated by the model. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE) syndrome: CNS malformations and seizures may be a component of this disorder
Authors: Gucev Zoran S. , Tasic Velibor , Jancevska Aleksandra , Konstantinova Marina Krstevska , Pop‐Jordanova Nada , Trajkovski Zoran , Biesecker Leslie G.
Published: September 2008

A newborn girl was found to have a massive lymphatic truncal vascular malformation with overlying cutaneous venous anomaly associated with overgrown feet and splayed toes. These manifestations comprise the recently described CLOVE syndrome. She also had cranial asymmetry and developed generalized seizures, which were treated with anticonvulsants. Cranial CT showed encephalomalacia, widening of the ventricles and the sulci, hemimegalencephaly (predominantly white matter) and partial agenesis of corpus callosum. Review of the literature identified several other patients with CLOVE syndrome, some of whom were misdiagnosed as having Proteus syndrome, with strikingly similar manifestations. We conclude that CNS manifestations including hemimegalencephaly, dysgenesis of the corpus callosum, neuronal migration defects, and the consequent seizures, may be an rarely recognized manifestation of CLOVE syndrome. © 2008 Wiley‐Liss, Inc.
Tastsysteme mit künstlichem Tastsinn wie beim menschlichen Finger
Authors: Maheshwari Vivek , Saraf Ravi
Published: September 2008

Dank unseres Tastsinns können wir die Oberflächentextur und Form von Gegenständen erkennen und Objekte ergreifen. Für die Herstellung einer elektronischen Haut, die für humanoide Roboter oder für die minimal‐invasive und ferngesteuerte Chirurgie den Tastsinn bereitstellen soll, müssen sowohl die (passiven) mechanischen Eigenschaften der Dermis als auch die charakteristischen Merkmale ihres Fühlmechanismus, besonders die digitale Funktion der Neuronen, nachgebildet werden. Dank des Einsatzes verschiedener Materialien und physikalischer Konzepte sind zwar erhebliche Fortschritte bei der Entwicklung einer elektronischen Haut zu verzeichnen, die Nachbildung des Tastsinns ist aber nach wie vor eine anspruchsvolle Aufgabe. Vor kurzem wurde ein Nanosystem entwickelt, das eine ähnliche Tastauflösung wie ein menschlicher Finger aufweist; verglichen mit anderen Systemen mit einer Kontaktfläche von über 1 cm2 ist dies eine Verbesserung um mehr als eine Größenordnung. Das neue System mit seinen robusten mechanischen Eigenschaften ist daher ein wichtiger Schritt hin zur Realisierung eines künstlichen Tastsinns.
Effect of preshearing on the structure and properties of poly(methyl methacrylate)/clay nanocomposite panels
Authors: Hwang Kab‐Jin , Kim Dae Su
Published: September 2008

The effect of preshearing resin mixtures prior to casting on the structure and properties of in situ polymerized poly(methyl methacrylate)/clay nanocomposite panels was investigated. The preshearing was performed with a mechanical stirrer and controlled by varying mixing time. The structure, thermomechanical, and optical properties of the panels prepared with different preshearing times were analyzed by XRD, TEM, DMA, and UV/visible spectrophotometer. The properties of the panels increased with preshearing time because of improved intercalation and exfoliation of the clay. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Cure behavior and thermal stability analysis of multiwalled carbon nanotube/epoxy resin nanocomposites
Authors: Yang Kai , Gu Mingyuan , Jin Yanping
Published: September 2008

As‐received multiwalled carbon nanotubes (MWCNTs) were first treated by a 3 : 1 (v/v) mixture of concentrated H2SO4/HNO3 and further functionalized by ethylenediamine/dicyclohexylcarbodiimide/tetrahydrofuran solution. MWCNT/epoxy nanocomposites were prepared. Their cure behaviors were investigated by dynamic differential scanning calorimetry. Quantitative analysis of the activation energy as a function of the degree of curing was carried out by the Flynn‐Wall‐Ozawa method. The fitted multiple regression equations for values of the activation energy of different systems were obtained. MWCNTs have the retardation effect on the cure reaction of epoxy resin, while the functional groups on the surface of amine‐modified MWCNTs could accelerate the cure reactions. Thermal stability was studied by thermogravimetric analysis. The filling of amine‐modified MWCNTs is beneficial to lower the cure activation energy and improve thermal stability of the nanocomposite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Sequences of fracture toughness micromechanisms in PP/CaCO3 nanocomposites
Authors: Khosh R. Lesan , Bagheri R. , Zokaei S.
Published: September 2008

Mechanical properties and fracture toughness micromechanisms of copolypropylene filled with different amount of nanometric CaCO3 (5–15 wt %) were studied. J‐integral fracture toughness was incorporated to measure the effect of incorporation of nanoparticle into PP matrix. Crack‐tip damage zones and fracture surfaces were studied to investigate the effect of nanofiller content on fracture toughness micromechanisms. It was found that nanofiller acted as a nucleating agent and decreased the spherulite size of polypropylene significantly. J‐integral fracture toughness (Jc) of nanocomposites was improved dramatically. The Jc value increased up to approximately two times that of pure PP at 5 wt % of nano‐CaCO3. The fracture micromechanisms varied from rubber particles cavitation and shear yielding in pure PP to simultaneous existence of rubber particles cavitation, shear yielding, filler particles debonding, and crazing in PP/CaCO3 nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of the new derivatives of cellulose and oligomeric species of cellulose containing magneson II chromophore
Authors: Namazi Hassan , Jafarirad Saeed
Published: September 2008

Fully acetylated cellulose triacetate (CTA) was hydrolyzed in the presence of hydronium ions in a solution of acetic acid and concentrated sulfuric acid to give a hydroxyl‐terminated cellulose triacetate oligomers (HCTA). By using gel permeation chromatography (GPC) analysis, the molecular weight of the isolated oligomeric product was calculated to be 3748 Da. HCTA was converted to their new derivatives having 4‐(4‐nitrophenylazo)‐1‐naphthol (magneson II) as a chromophore. Then 4′‐bromobutoxy‐4‐(4‐nitrophenylazo) naphthalene was synthesized from the reaction of 4‐(4‐nitrophenylazo)‐1‐naphthol with 1,4‐dibromobutane. The synthesized alkylated chromophore was reacted with oligomeric cellulose and cellulose itself in the solution of dimethyl sulfoxide to produce cellulose ethers containing the desired chromophore. In the last step, the isolated compounds were used for the preparation of new polymers and oligomers, which contain both of dodecane and butoxy‐4‐(4‐nitrophenylazo)naphthalene as the alkyl side chains in their backbone. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal and thermomechanical properties of hyperbranched polyurethane‐urea/cenosphere hybrids
Authors: Jena Kishore K. , Mishra Aswini K. , Raju K. V. S. N.
Published: September 2008

Hyperbranched polyurethane (HBPU)‐urea/cenosphere hybrid coatings were synthesized by incorporating various concentrations of cenosphere into HB polyester matrix by ultrasonication technique, and this polyester was further used for the preparation of isocyanate terminated HBPU prepolymers by reacting with excess isophorone diisocyanate (IPDI) in a NCO/OH ratio of 1.6 : 1. The desired hybrid coating is obtained by moisture curing the excess NCO present in the prepolymer through film casting. The structure of the hyperbranched polyester (HBPE) was conformed by 1H, 13C NMR and FTIR spectroscopy and the degree of branching (DB) was calculated using Frechet and Frey equations. These hybrid films were characterized by powder XRD, FTIR, SEM, DMTA, and TGA. The structure property correlation, intermolecular/intramolecular hydrogen bonding, the surface morphology, and viscoelastic properties were studied. These results showed an increase in Tg and thermal stability of the hybrid coatings than the base polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and properties of silylene–acetylene preceramic polymers
Authors: Ye Li , Han Weijian , Zhang Ruilin , Hu Jidong , Zhao Tong
Published: September 2008

A series of silylene–acetylene preceramic polymers 3a–e were synthesized by polycondensation reaction of dilithioacetylene with dichlorosilane (H2SiCl2) or/and methyldichlorosilane (MeSiHCl2). Their structures were confirmed by infrared spectra (IR), and 1H and 29Si NMR spectroscopies. Differential scanning calorimetry (DSC) diagrams show exotherms centered at 200 to 233°C temperature range, attributed to crosslinking reaction of the acetylene and SiH groups. After thermal treatment, the obtained thermosets 4a–e possess excellent thermal stability. Thermogravimetric analysis (TGA) under nitrogen show the Td5s (temperature of 5% weight loss) for all the thermosets are above 600°C, and the overall char yields are between 95.62% and 89.67% at 900°C. After pyrolysis at 1200°C, the obtained ceramic residues 5a–e exhibit good thermo‐oxidative stability with final weight retention between 98.76% and 91.66% at 900°C under air. In particular, perhydroploy(silylene)ethynylene 3a, which has the highest Si/C ratio in silylene–acetylene polymers, has the highest char yield, and the derived ceramic material 5a displays the best thermo‐oxidative stability. Based on Scanning electron microscopy and its associated energy‐dispersive X‐ray microanalysis (SEM EDX) and 13C magic angle spinning nuclear magnetic resonance (MAS NMR) analysis, ceramic 5a contains the highest SiC content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of grafted maleic anhydride content and recyclability of dynamically cured maleated natural rubber/polypropylene blends
Authors: Nakason Charoen , Saiwari Sitisaiyidah
Published: September 2008

Maleated natural rubbers (MNRs) were prepared using various levels of maleic anhydride (MA) at 4, 6, 8, 10, and 12 phr. Dynamically cured 60/40 MNR/PP blends with phenolic‐modified polypropylene (Ph‐PP) compatibilizer at a loading level of 5 wt % of PP were prepared by melt mixing process using sulfur vulcanization system. The influence of the level of MA on properties of the thermoplastic vulcanizates (TPVs) was studied. It was found that the mixing torque, apparent shear stress, shear viscosity, tensile strength, and hardness properties increased with increasing levels of the MA or grafted succinic anhydride groups in the MNR molecules. This is attributed to an increase in chemical interaction and reaction between methylol groups in the Ph‐PP molecules and polar functional groups in the MNR molecules upon increasing levels of the grafted succinic anhydride groups. As a consequence, compatibilizing block copolymers of MNR and PP blocks were formed. The block copolymers were capable of compatibilizing with MNR and PP blend components via the respective blocks. Recyclability of the MNR/PP TPVs was also studied. It was found that, after processing through a number of cycles by injection molding and extrusion processing, the TPV exhibited marginal decreases in mechanical properties. This corresponded to slightly increasing size of the dispersed vulcanized rubber domains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A multi‐attribute trade‐off approach for advancing the management of marine wildlife tourism: a quantitative assessment of heterogeneous visitor preferences
Authors: Semeniuk Christina A.D. , Haider Wolfgang , Beardmore Ben , Rothley Kristina D.
Published: September 2008

Wildlife tourism can be prone to unmitigated development to promote visitor satisfaction that is all too often progressed at the cost of ecological integrity. A manager is thus faced with the dual task of enhancing the tourist experience and protecting the wildlife species. Accordingly, this mandate requires research into how tourists would respond to proposed wildlife‐management plans.

This study examines the heterogeneity of tourist preferences for wildlife management at a stingray‐feeding attraction in the Cayman Islands, using a latent class stated preference choice model. A sample of visitors to Stingray City Sandbar (SCS) evaluated hypothetical wildlife viewing experiences in a discrete choice experiment. Its scenarios were characterized by seven attributes such as animal‐feeding and handling rules, ecological outcomes, social crowding, and management cost (defined as a conservation access fee).

The latent class segmentation identified two groups in the population: approximately 68% preferred the implementation of fairly strict management rules, while the other 32% valued more the maintenance of status quo with its intensive human — wildlife interactions. Despite the differences between the ‘pro‐management’ and the ‘pro‐current’ segments, both exhibited a preference for the continuation of feeding and handling the stingrays (albeit at different levels of intensity) suggesting that one effective way to implement any management actions is to alter the promotional and marketing strategies for SCS. Other survey questions on trip experience, conservation values, and socio‐demographics were used to define these classes further, with the main distinguishing trait being the level of concern for potential impacts occurring at SCS. The discrepancies between the two segments became most obvious when calculating their respective market shares of support for alternative management strategies.

This approach to determining visitor preferences can help explain how the various segments will be affected by management options, and therefore can provide the basis for developing feasible strategies that will assist wildlife managers in maximizing tourist satisfaction while achieving wildlife‐protection goals.

Copyright © 2008 John Wiley & Sons, Ltd.
New Amides of 5‐(4‐Chlorobenzoyl)aminoorotic Acid: Their Synthesis and Biological Activity
Authors: Regiec Andrzej , Śpiewak Magdalena , Jasztold‐Howorko Ryszard , Miedzybrodzki Ryszard
Published: September 2008

The synthesis and in‐vitro biological evaluation of the amide series 4 of 5‐(4‐chlorobenzoyl)aminoorotic acid 2 are presented. The biological properties of a few 5‐(4‐chlorobenzoyl)amino‐2,6‐dihydroxy‐N‐substituted‐4‐pyrimidinecarboxamide derivatives 4 tested here were compared with those of the isosteric isothiazole derivative MR‐2/94 (5‐(4‐chlorobenzoyl)amino‐N‐(4‐chlorophenyl)‐3‐methyl‐4‐isothiazolecarboxamide), which possesses a strong immunosuppressive and anti‐inflammatory activity [1, 2], It must be suggested that replacement of the isothiazole by a pyrimidine core ring system resulted in considerable lowering of the anti‐inflammatory and immunotropic actions of the obtained amides. Physicochemical properties of 2‐(4‐chlorophenyl)‐6,8‐dihydroxy‐4H‐pyrimido[5,4‐d]‐1,3‐oxazin‐4‐on 3 are also briefly described.
Refined Docking as a Valuable Tool for Lead Optimization: Application to Histamine H3 Receptor Antagonists
Authors: Levoin Nicolas , Calmels Thierry , Poupardin‐Olivier Olivia , Labeeuw Olivier , Danvy Denis , Robert Philippe , Berrebi‐Bertrand Isabelle , Ganellin C. Robin , Schunack Walter , Stark Holger , Capet Marc
Published: September 2008

Drug‐discovery projects frequently employ structure‐based information through protein modeling and ligand docking, and there is a plethora of reports relating successful use of them in virtual screening. Hit / lead optimization, which represents the next step and the longest for the medicinal chemist, is very rarely considered. This is not surprising because lead optimization is a much more complex task. Here, a homology model of the histamine H3 receptor was built and tested for its ability to discriminate ligands above a defined threshold of affinity. In addition, drug safety is also evaluated during lead optimization, and “antitargets” are studied. So, we have used the same benchmarking procedure with the HERG channel and CYP2D6 enzyme, for which a minimal affinity is strongly desired. For targets and antitargets, we report here an accuracy as high as at least 70%, for ligands being classified above or below the chosen threshold. Such a good result is beyond what could have been predicted, especially, since our test conditions were particularly stringent. First, we measured the accuracy by means of AUC of ROC plots, i. e. considering both false positive and false negatives. Second, we used as datasets extensive chemical libraries (nearly a thousand ligands for H3). All molecules considered were true H3 receptor ligands with moderate to high affinity (from μM to nM range). Third, the database is issued from concrete SAR (Bioprojet H3 BF2.649 library) and is not simply constituted by few active ligands buried in a chemical catalogue.
Synthesis and SAR Study of T‐Type Calcium Channel Blockers. Part II
Authors: Choe Yun Jeong , Seo Han Na , Jung Soo Yeon , Rhim Hyewhon , Kim Jungahn , Choo Dong Joon , Lee Jae Yeol
Published: September 2008

3,4‐Dihydroquinazoline derivatives have been known to be the novel and potent T‐type calcium channel blockers. From a systematic variation of 3,4‐dihydroquinazoline derivative 5c (KYS05043), plausible SAR results were established. It was revealed that a 5‐(dimethylamino)pentylamino group at R1, a biphenyl group at R2, and a benzyl amido group at R3 in the 3,4‐dihydroquinazoline backbone are closely related with the channel selectivity (T/N‐type) as well as the potency based on the discovery of 6k (KYS05090).
Synthesis and Biochemical Characterization of New Phenothiazines and Related Drugs as MDR Reversal Agents
Authors: Schmidt Matthias , Teitge Marlen , Castillo Marianela E. , Brandt Tobias , Dobner Bodo , Langner Andreas
Published: September 2008

Chemotherapy is one of the most important methods in the treatment of cancer. However, development of drug resistance during chemotherapy is the leading cause of treatment failure and decreased survival in cancer patients. Multidrug resistance (MDR) is one of the extensively studied forms of drug resistance for more than 30 years. The members of ATP‐binding cassette protein family are responsible for multidrug resistance with P‐glycoprotein as most representative transporter. To overcome multidrug resistance, pharmacological modulation of the transporters by efflux pump inhibitors seem to be the first choice, but preclinical studies did not lead to clinical applications. Therefore, a systematical research for pharmacophor structures is a promising strategy to increase the efficacy of those drugs still influencing multidrug resistance. In this study a range of phenothiazine derivatives was synthesizied with systematical variation of three molecule domains. The biochemical determination of multidrug resistance reversal activity was achieved with the crystalviolet assay on LLC‐PK1/MDR1 cells. The results will be discussed considering of hypotheses in the literature directed to new structure‐acitivity relationships to overcome drug resistance in the future.
Further studies of the heat island associated with a small midwestern city
Authors: Buckley Patrick I. , Market Patrick S. , Lupo Anthony R. , Fox Neil
Published: September 2008

Recently, the University of Missouri (UM) moved its SuomiNet station from the roof of a building near downtown Columbia, Missouri, USA, to the University's rural South Farm. Comparisons of Columbia Regional Airport (KCOU) data and SuomiNet data are presented both prior to and after the latter's relocation. Analysis reveals an elevation of mean temperature by ∼1.5 °C at the downtown location, but no difference between the more rural station and KCOU. These results show that the influence of the Columbia heat island does not extend to 7 km from the city center and that the present SuomiNet location is now more representative. Copyright © 2008 Royal Meteorological Society
Photo‐immobilization of biological components on gold‐coated chips for measurements using surface plasmon resonance (SPR) and a quartz crystal microbalance (QCM)
Authors: Tsuzuki Saki , Wada Akira , Ito Yoshihiro
Published: September 2008

The photo‐immobilization technique is useful for immobilization of various biomolecules on assorted material surfaces, independent of the organic functional groups that may be present. Here, we report a convenient new photo‐immobilization technique that was developed by combining a nonbiofouling polymer containing polyethylene glycol and a photoreactive crosslinker for surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) measurements. By this method, nonspecific interactions were reduced and various types of molecules, bovine serum albumin, heparin, dsDNA, phosphatidylserine, Tobacco Mosaic Virus, and norfloxacine, were immobilized on an alkane thiol‐modified gold surface by a single method. The interactions of photo‐immobilized biomolecules and their corresponding antibodies were investigated by SPR and QCM. In addition, SPR imaging was possible using the present method. Biotechnol. Bioeng. 2009; 102: 700–707. © 2008 Wiley Periodicals, Inc.
Development of a denaturation/renaturation‐based production process for ferritin nanoparticles
Authors: Jääskeläinen Anu , Soukka Tero , Lamminmäki Urpo , Korpimäki Teemu , Virta Marko
Published: September 2008

Recently, we presented a simple method for generating biological functional protein‐based nanoparticles that are ready for use as label agents in bioaffinity assays (Jääskeläinen et al., 2007 Small 3:1362–1367). In this process, the particle shell (ferritin protein) and binding molecules are conjugated via genetic fusion, and particles with binding capacity are produced in a single bacterial cultivation. Production is combined with simple, non‐chromatographic purification during which Europium ions are introduced into particles to serve as marker agents. Denaturation‐refolding has previously performed by means of pH changes. Here, we test urea as an alternative agent for denaturation, and examine techniques to improve refolding of the functional particles. Three different types of binding molecules were employed in our experiments: biotin carboxyl carrier protein (a small protein with 87 amino acids), single chain antibody fragment (a complex binding protein) and calmodulin‐binding peptide (27 amino acids). Urea was successfully utilized to generate functional particles with inherent binding activity and label function. Additionally, particle yield was effectively optimized by analyzing various refolding and bacterial production conditions. Our results clearly demonstrate that this simple biological method of producing functional ferritin‐based particles is flexible, and different types of binding moieties can be applied by adjusting the production conditions. Biotechnol. Bioeng. 2009;102: 1012–1024. © 2008 Wiley Periodicals, Inc.
Simultaneous determination of main taxoids in Taxus needles extracts by solid‐phase extraction‐high‐performance liquid chromatography with pentafluorophenyl column
Authors: Fu Yu‐Jie , Sun Rui , Zu Yuan‐Gang , Li Shuang‐Ming , Liu Wei , Efferth Thomas , Gu Cheng‐Bo , Zhang Lin , Luo Hao
Published: September 2008

A simple and accurate RP‐HPLC method with pentafluorophenyl (PFP) column was developed for the simultaneous determination of six taxoids, i.e. paclitaxel, 10‐deacetylbaccatin III (10‐DAB III), 7‐xylosyl‐10‐deacetyltaxol (7‐xyl‐10‐DAT), 10‐deacetyltaxol (10‐DAT), cephalomannine and 7‐epi‐10‐deacetyltaxol (7‐epi‐10‐DAT), in the extracts from the needles of three Taxus species. The mobile phase consisted of acetonitrile (A) and water (B), and the extracts were separated using gradient elution program: 30% A at the first 7 min, and then ramped to 42% A at 8 min, held until 38 min. The developed method was validated with satisfactory precision (RSD < 2.61%), repeatability (RSD < 2.92%) and recovery (95.19–104.47%). The above taxoids in the extracts of Taxus cuspidata, T. chinensis and T. media were analyzed with the developed RP‐HPLC method, and the results showed that the contents of different taxoids in three mentioned species were distinct. Maximal amounts of 10‐DAB III, 7‐xyl‐10‐DAT and 7‐epi‐10‐DAT appeared in T. chinensis, while T. media possessed the highest content of 10‐DAT, cephalomannine and paclitaxel. The developed method is accurate and efficient. It can be reliably used in the improved determination of taxoids for the quality control of Taxus species. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous determination of mifepristone and monodemethyl‐mifepristone in human plasma by liquid chromatography–tandem mass spectrometry method using levonorgestrel as an internal standard: application to a pharmacokinetic study
Authors: Tang Cheng , Bi Hui‐chang , Zhong Guo‐ping , Chen Xiao , Huang Zhi‐ying , Huang Min
Published: September 2008

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC‐MS/MS) method was developed and validated to simultaneously determine mifepristone and monodemethyl‐mifepristone in human plasma using levonorgestrel as the internal standard (IS). After solid‐phase extraction of the plasma samples, mifepristone, monodemethyl‐mifepristone and the IS were subjected to LC‐MS/MS analysis using electro‐spray ionization (ESI) in the multiple reaction monitoring (MRM) mode. Chromatographic separation was performed on an XTERRA MS C18column (150 × 2.1 mm i.d., 5 µm). The method had a chromatographic run time of 4.5 min and linear calibration curves over the concentration ranges of 5–2000 ng/mL for mifepristone and monodemethyl‐mifepristone. The recoveries of the method were found to be 94.5–103.7% for mifepristone and 70.7–77.3% for monodemethyl‐mifepristone. The method had a lower limit of quantification (LLOQ) of 5.0 ng/mL and a lower limit of detection (LOD) of 1.0 ng/mL for both mifepristone and monodemethyl‐mifepristone. The intra‐ and inter‐batch precision was less than 15% for all quality control samples at concentrations of 10, 100 and 1000 ng/mL. These results indicate that the method was efficient with a short run time (4.5 min) and acceptable accuracy, precision and sensitivity. The validated LC‐MS/MS method was successfully used in a pharmacokinetic study in healthy female volunteers after oral administration of 25 mg mifepristone tablet. Copyright © 2008 John Wiley & Sons, Ltd.