bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Frictional Forces Generated by Three Different Ligation Methods
Authors: Gandini Paola , Orsi Linda , Bertoncini Chiara , Massironi Sarah , Franchi Lorenzo
Published: February 2008

Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures.

Materials and Method: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014″ super elastic nickel titanium wire and 0.019″ × 0.025″ stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state.

Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87–177 g) (P < .05) when CEL on CB was used with both wires.

Conclusion: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.
Orthodontic Attachments and Chlorhexidine-Containing Varnish Effects on Gingival Health
Authors: Paschos Ekaterini , Limbach Mirjam , Teichmann Marion , Huth Karin C. , Folwaczny Matthias , Hickel Reinhard , Rudzki-Janson Ingrid
Published: February 2008

Objective: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)–1β during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated.

Materials and Methods: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1β.

Results: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1β levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PDBand, PIBand, PIBracket, GIBand, GIBracket; P < .015).

Conclusion: The clinically observed parameters as well as the IL-1β levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets.
Soft-Tissue Facial Characteristics of Attractive and Normal Adolescent Boys and Girls
Authors: Sforza Chiarella , Laino Alberto , D'Alessio Raoul , Grandi Gaia , Tartaglia Gianluca Martino , Ferrario Virgilio Ferruccio
Published: February 2008

Objectives: To identify possible esthetic canons in facial size and shape of Italian adolescent boys and girls.

Materials and Methods: The three-dimensional coordinates of 50 facial landmarks (forehead, eyes, nose, cheeks, mouth, jaw, ears) were collected in 231 healthy, reference adolescents (10– 17 years old) and in 93 similar age group “attractive” adolescents selected by a commercial casting organization. Soft-tissue facial angles, distances, areas, and volumes were computed. Comparisons were made with analysis of variance.

Results: Attractive adolescents had wider, shorter, and less deep faces than reference adolescents, with a relatively larger forehead and maxilla, and a reduced mandible relative to the maxilla. Lips were larger and more prominent, and the nasolabial angle was reduced, but in older boys the effect was reversed. The prominence of the soft-tissue profile, and of the maxilla relative to the mandible, were larger in attractive boys, but smaller in attractive girls than in their reference peers. In the horizontal plane, attractive “young” adolescents had a flatter face, while the opposite pattern was observed in the “old” adolescents, with a relatively more prominent chin. Attractive adolescents had smaller noses than reference subjects of the same age and sex.

Conclusions: Overall, all the measurements appeared sufficiently homogenous, and the quantitative characteristics of an “attractive” face well defined. Esthetic reference values can be used to determine optimal timing and goals in orthodontic treatment.
Early Treatment with a Maxillary Lip Bumper-Bite Plateau Combination
Authors: Korn Marcel , Melsen Birte
Published: February 2008

Objective: To evaluate the intra-arch displacements of the molars and the change in molar relationship following the use of a maxillary lip bumper combined with a bite plate.

Materials and Methods: The material comprised study casts taken before and after the treatment of 40 consecutive patients with mixed dentition. The sagittal and transversal displacements were evaluated by a three-dimensional digitizer using the palatal rugae as an indirect fixed reference. The displacements were expressed as translation mesiodistally and buccolingually and rotation around the long axis and tipping mesiodistally. The change in molar relationship was measured to the nearest millimeter at the level of the occlusal plane.

Results: The tooth movements were predominantly of distal rotation (mean, 9.7°; range, 6.5° to 26°) and distal tipping (mean, 5°; range, 5.8° to 18°). The distal displacement was a modest mean (mean, 0.3 mm; SD, 1.6 mm) and more pronounced to the buccal (mean 1.6 mm; SD, 1.5 mm). The molar relationship improved in all but four sites, and a full Class I was obtained in 65 of 80 sites.

Conclusions: The early treatment with the lip bumper and bite plate can be recommended from a cost-benefit point of view.
Defining, Conceptualizing, and Measuring Fidelity of Implementation and Its Relationship to Outcomes in K–12 Curriculum Intervention Research
Authors: O’Donnell Carol L.
Published: February 2008

Education researchers are being asked to conduct rigorous, scientifically based studies of K–12 curriculum interventions; therefore, the need for measuring fidelity of implementation and empirically relating it to outcomes (the chief rationale for this review) is warranted to ensure internal and external validity. The results of this review indicate that there are too few studies to guide researchers on how fidelity of implementation to core curriculum interventions can be measured and related to outcomes, particularly within efficacy and effectiveness studies, where the requirements for fidelity measures differ. This review attempts to clarify the definition, conceptualization, and measurement of fidelity of implementation and to guide future researchers in understanding how fidelity of implementation can be used to adjust or interpret outcome measures.
The Dynamic Apparent Viscosity of Polymer Melts During Pulsatile Extrusion Flow with Vibration Force Field
Authors: He G.-J. , Yin X.-C. , Qu J.-P.
Published: February 2008

The dynamic apparent viscosity of polymer melts during pulsatile extruding flow with a vibration force field was studied on a self-made dynamic capillary rheometer (DCR). A theory that could reflect the vibration influence on the dynamic apparent viscosity was proposed. Due to the superposition of the vibration force field upon the steady shear flow, the phase difference between the shear stress and the shear rate could be chosen as a parameter to reflect the effect of vibration on the dynamic apparent viscosity. According to this theory, the average shear rate during pulsatile extrusion increased because of the existence of the phase difference, which caused the decrease of the dynamic apparent viscosity. The experimental results proved that the phase difference was reduced with the increase of vibration frequency, which resulted in a decrease in the dynamic apparent viscosity during the pulsatile extrusion.
Influence of Uniaxial Extension on the Mechanical Properties of PET and PEN Films
Authors: Wang J. H. , Kim J. H. , Kang H. J. , Talke F. E.
Published: February 2008

The modulus and hardness of poly(ethylene terephthalate)-(PET) and poly(ethylene naphthalate)(PEN) films are studied as a function of the uniaxial draw ratio using nanoindentation and macro-scale tensile testing equipment. Nanoindentation tests were conducted in the machine-transverse plane, the transvers-normal plane, and the machine-normal plane of the PET and PEN films to determine mechanical properties (hardness and modulus of elasticity) of the uniaxially stretched films at the nano-scale. The films were then re-tested using a tensile tester to determine the modulus on the macro-scale. The results from the two methods show large differences. Birefringence measurements indicate that the macro-scale and nano-scale moduli are strongly influenced by the chain orientation after uniaxial stretching. In addition, the influence of chain orientation is found to be much larger on the macro-scale than on the nano-scale.
Non-Isothermal Simulation of the Film Blowing Process Using Multi-Mode Extended Pom-Pom Model
Authors: Sarafrazi S. , Sharif F.
Published: February 2008

Plastic films are largely produced using the film blowing process. Branched polymers such as LDPE are commonly used in this process to produce a variety of plastic films. In this study, recently developed eXtended Pom-Pom (XPP) model, which focuses on describing rheological behavior of branched polymers, is employed to analyze the non-isothermal flow in the film blowing process. Furthermore, the Nakamura equation for crystallization kinetics is employed to consider crystallization effects and improve prediction of the state of the stress in the film. Results of the numerical analysis show good agreement with the experimental values reported by Tas (1994) for the bubble shape and film velocity of the LDPE films. Predictions for the strain rates in machine and hoop directions which are critical for the estimation of the stress are also compared with the reported data and showed reasonably good agreement.
Flow Analysis of Flat Spiral Dies and Comparison with Cylindrical Spiral Mandrel Dies
Authors: Malekzadeh M. , Goharpey F. , Foudazi R.
Published: February 2008

Cylindrical Spiral Mandrel Dies (SMD) and Flat Spiral Dies (FSD) are widely used in blown film co-extrusion processes. Although in recent years the use of stackable (flat) spiral dies in the blown film extrusion has been continuously growing, a phenomenological study on designing parameters of this type of dies, and comparison of their flow distribution with SMD has not been made yet. In this work, the flow of a viscous power law fluid in a typical flat spiral die, based on Rauwendaal's method (1987) for analyzing cylindrical spiral mandrel dies, has been investigated. Validation of this method for flat spiral dies was confirmed by comparison with the results reported using the finite element method. The effects of some design parameters, such as number of grooves, initial flight clearance, initial groove depth, on pressure gradient, flow distribution and other operational variables have also been studied. It has been found that the flow distribution becomes more uniform with increasing number of grooves, initial groove depth and coefficient of Archimedes type flat spiral. Moreover, the results have shown that the increment of the clearance angle between two die plates, as well as the initial clearance, have an optimum value in which the flow distribution is the most uniform. Finally, flow variations in FSD and SMD have been compared for different design parameters. The results demonstrated that the melt flow distribution at the outlet of the cylindrical spiral mandrel die is more uniform, while the pressure loss of the flat spiral die is lower.
Development of Polymer Blend Morphology along an Extruder with Different Screw Geometries
Authors: Huang H.-X. , Jiang G. , Li X.-J.
Published: February 2008

The morphology development of an immiscible polymer blend along a single screw extruder was investigated, concentrating on the effect of screw geometry. Three different screw geometries were evaluated: one with conventional screw elements; the other two with a fluted and Pineapple mixing element, respectively. The experiments were conducted using a polypropylene/polyamide-6 (PP/PA 6) blend. The blend samples were collected from four different positions using specially designed sampling device along the extruder online during blending and were then examined using scanning electron microscopy. The experimentally observed morphology evolution was evaluated both qualitatively, in terms of spatial distribution of dispersed phase, as well as quantitatively, by analysis for the size of the dispersed phase. The morphology development was interpreted with the aid of the flow fields occurring along screw elements. The results showed that the screw with conventional screw elements produce the coarsest and most non-uniform morphology whereas the screw with a fluted mixing element appears to produce the finest and most uniform morphology at the end of the extruder. The Pineapple mixing element, with a characteristic of chaotic mixing, facilitates to form thinner laminar layers of dispersed phase. The experimentally observed morphology difference between the conventional and fluted mixing element was demonstrated by the simulation.
Melting Mechanism of Thermoplastic Elastomers and Comparison to Polyolefin Thermoplastic Melting Studies in a Single Screw Extruder
Authors: Lu W.-J. , Bumm S. H. , White J. L.
Published: February 2008

An experimental investigation of the mechanisms of melting of various thermoplastics elastomers (TPEs) in single screw extruder was carried out under different operating conditions. The TPEs included three polypropylene vulcanized EPDM (TPV) thermoplastic elastomers and two styrene-hydrogenated butadiene block copolymer. The results were compared to new and earlier experimental investigations of the melting of polyethylene and polypropylene. We also characterized the shear viscosity of all polymer melts studied. The TPEs all exhibited yield values in shear flows. To characterize the melting process in a single screw extruder, we used a flow marker procedure which consists of introducing pigments with the neat pellets. This is a technique originally developed by Maddock (1959). At the steady state, we abruptly stopped the extruder operation, cooled the barrel and pushed the screw from the barrel. The polymer carcasses were stripped from the screws and slices cross-sectioned every turn from the hopper to die were photographed and evaluated, and the melting mechanism was determined. The results for the TPEs exhibit significant differences from the crystalline polyolefin.
Shrinkage Analysis on Convex Shellby Injection Molding
Authors: Chen C.-C. A. , Chang S.-W.
Published: February 2008

Injection molding of a convex shell has induced divergent flow front directions and therefore the shrinkage of a convex shell is difficult to controll. In some optical applications, such as ophthalmic devices of soft contact lens, that can be cast molded with a set of two convex shells made by injection molding there is a demand in maintaining dimensional stability. This research investigates the optimization of injection molding parameters for the minimum shrinkage of a convex shell of polypropylene (PP). The MPI 5.0 software is used first to simulate the filling stage of the convex shell and find the feasible operational ranges of parameters. Experiments were performed by an electric injection machine. Short shot experiments have been tested to compare with results of mold flow simulation. Taguchi's method is then used to find the optimal parameters for the minimum shrinkage of convex shell. Four parameters or factors, including mold temperature, injection temperature, holding pressure, and cooling time are considered in this study. An ANOVA table has been obtained for checking the significance of parameters. Results of simulation and experiments have been compared and the holding or packing pressure is found as the most significant parameter for the minimum shrinkage of a convex shell. Cooling time and injection temperature have been found as the second and third most significant parameters in this study. The optimal parameters have been established and then verified by the optimal injection molding experiment and the minimum shrinkage of convex shell was obtained as 72 μm.
Thermal Degradation of Meta- and Para-Aramid Fibers in Different Atmospheres
Authors: Wang X.-W. , Hu Z.-M. , Liu Z.-F.
Published: February 2008

The thermal degradation behavior of meta- and para-aramid fibers (PMIA and PPTA) in different atmospheres was studied by thermogravimetric analysis coupled with mass spectrometry (TGA-DTA/MS). The process of mass loss in the degradation of PMIA was divided into three steps in both argon and air. The mass loss of PPTA was greater than that of PMIA in argon when the temperature reached 1000°C. Simultaneous TG/DTA measurements showed that the thermal degradation was endothermic in argon and exothermic in air for both fibers. Mass spectra of volatiles were obtained, and PMIA and PPTA gave similar mass signals. The temperatures of maximum abundances in ion currents corresponded to the temperatures of mass loss peaks in the DTG curves. The relative values of ion currents were compared at various temperatures. The yield of CO2 was the largest fraction in ion currents of all the volatiles, and the abundances of ion currents of phenyl compounds were low. The elemental analyses of decomposed PMIA and PPTA fibers provided direct information of chemical and morphological changes. A synthetic kinetic model was introduced, and the analyses of kinetic parameters were used to explain the degradation progresses.
Experimental Studies on Screw Characteristics in Closely Intermeshing Counter-rotating Twin Screw Extruder
Authors: Hong M.-H. , Jiang Q. , White J. L.
Published: February 2008

Experimental studies were carried out to characterize the screw pumping behavior of various screw elements for a closely intermeshing counter-rotating twin screw extruder. The pumping capacity of the screw elements was compared to earlier flow simulations by some the authors of this type of twin screw extruder.
Experimental Analysis of Heat Transfer in Rotational Molding Process
Authors: Sobotka V. , Perot E. , Maazouz A. , Delaunay D.
Published: February 2008

Rotational molding is a process by which powdered or liquid plastics are converted into hollow articles. This process is relatively simple in a technical point of view but it involves very complex physical phenomena. Constant quality in technical parts requires the mastery of the process by controlling on line these phenomena. One of these of first importance is heat transfer. This paper concerns the experimental analysis of heat transfer in rotational molding process with semi-crystalline polymer. By using an instrumented mold associated with an original radio transmission data acquisition system, we demonstrate that the rotational nature of the process implies complex heat transfer evolutions in the mold. The crystallization of the material is modeled with accuracy by coupling heat transfer equation to a kinetic model determined by calorimetry. It appears that thermal contact resistance evolution is a key point of heat transfer during the solidification of the polymer.
Experimental Study and Modeling of Flow Behavior and Orientation Kinetics of Layered Silicate/Polypropylene Nanocomposites in Start-up of Shear Flows
Authors: Rajabian M. , Naderi G. , Beheshty M. H. , Lafleur P. G. , Dubois C. , Carreau P. J.
Published: February 2008

Effects of organoclay contents on the startup flow properties of layered nano-scale particles in the simple shear mode are investigated. The addition of small amounts of nanoclays to polypropylene melts was found to dramatically change the flow characteristics and creates stress overshoots at large shear rates. A rheological model, initially developed for studying the motion of a group of symmetric ellipsoid particles in viscoelastic fluids was used to describe the orientation state of the uniformly dispersed suspensions of layered silicate in polypropylene melts. The effects of shear, particle loadings, particle interactions, flow reversal and rest time after cession of shear are studied and discussed according to our experimental observations and model predictions. It is shown that another diffusion term in the governing equation for the particles can be used to predict the properties by applying the rest time which was found to change the orientation of particles and shifts it to more isotropic microstructures. The experimental results of the startup viscosity are reasonably well predicted by the model at the three shear rates tested.
Grazing as a factor structuring grasslands in the Pyrenees
Authors: Sebastià Maria‐Teresa , de Bello Francesco , Puig Laura , Taull Marc
Published: February 2008

Questions: What are the relative roles of abiotic and grazing management factors on plant community distribution in landscapes? How are livestock type and stocking rate related to changes in vegetation structure and composition?

Location: Sub‐alpine grasslands in the central and eastern Pyrenees.

Methods: Multivariate analysis and variance partitioning methods were used to evaluate the relative roles of environmental factors in structuring vegetation composition and diversity patterns in three surveys on differently managed grasslands.

Results: Vegetation composition within a region was affected by environmental factors hierarchically, changing first according to abiotic factors and then to grazing management. At landscape scales, abiotic factors explained two‐fold more variation in vegetation composition than grazing factors. Within landscape units, cattle grazing increased vegetation heterogeneity at landscape and patch scales, while sheep grazing favoured the presence of a specific set of species with high conservation value. Species composition was highly responsive to management variables compared to diversity components.

Conclusions: The combination of sheep and cattle grazing at various stocking rates is an effective tool to preserve the diversity of plant species and communities within a region with a long tradition of livestock management, through the scaling up of effects by local processes occurring in patches at smaller scales.
Strong shifts in plant diversity and vegetation composition in grassland shortly after climatic change
Authors: Sebastià Maria‐Teresa , Kirwan Laura , Connolly John
Published: February 2008

Questions:

Is plant diversity in mesic grassland ecosystems vulnerable in the short‐term to extreme climate change events? How rapidly can responses in vegetation composition occur in perennial grasslands? Are the expected compositional changes related to rare species losses or to shifts in the relative abundance of the dominants?

Location:

Subalpine mesic grasslands on limestone in the Pyrenees.

Methods:

Transplanting turves from the upland, with cold‐temperate climate, to a lowland location, with continental Mediterranean climate.

Results:

Transplanting led to decreased biodiversity and strong shifts in vegetation composition. Results from both permutation tests and traditional multivariate analysis suggested different trajectories of vegetation depending on the initial species pool. Vegetation showed a tendency to converge in composition in the lowland over time, independently of initial differences. Estimated changes in relative biomass of the five most abundant species between the upland and the lowland ranged from ‐89 to +96 %. The ensemble of all other species was reduced by 80%. The most dominant species in the upland, Festuca nigrescens, reduced its abundance in the lowland, shifting from having mainly positive to mainly negative associations with other species.

Conclusions:

Mesic grassland ecosystems in the Pyrenees showed strong shifts in plant diversity and composition after a short period of warming and drought, as a consequence of acute vulnerability of some dominant grasses, losses of rare species, and aggregate and trigger effects of originally uncommon forb species.
Increasing Fluency in First Graders: Practice Makes Perfect, or at Least Better
Authors: Broemmel Amy , Boruff Kristi , Murphy-Racey Ellie
Published: February 2008

There is a strong research base indicating that students who read more are better readers, but in the seven years since the report of the National Reading Panel (NICHHD, 2000), there has been much controversy surrounding the impact of Sustained Silent Reading (SSR) on students' reading achievement. This study attempted to assess the effects of time spent reading on first grade students' attitudes and fluency. Two first grade teachers dedicated 45 minutes at the end of every day to independent reading for a 7 week period. Pre- and post-assessment data were collected using two instruments: surveys for attitude and timed readings for fluency. One first grade classroom in the same school served as the control group. Results indicate that although there were no significant patterns in attitudinal changes, there was evidence of increased fluency across all ability levels, both in words read per minute and, more notably, in accuracy rates.
Optimal and self‐tuning fusion Kalman filters for discrete‐time stochastic singular systems
Authors: Sun Shu‐Li , Ma Jing , Lv Nan
Published: February 2008

Based on the optimal fusion estimation algorithm weighted by scalars in the linear minimum variance sense, a distributed optimal fusion Kalman filter weighted by scalars is presented for discrete‐time stochastic singular systems with multiple sensors and correlated noises. A cross‐covariance matrix of filtering errors between any two sensors is derived. When the noise statistical information is unknown, a distributed identification approach is presented based on correlation functions and the weighted average method. Further, a distributed self‐tuning fusion filter is given, which includes two stage fusions where the first‐stage fusion is used to identify the noise covariance and the second‐stage fusion is used to obtain the fusion state filter. A simulation verifies the effectiveness of the proposed algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
Biphasic Aqueous Organometallic Catalysis Promoted by Cyclodextrins: How to Design the Water‐Soluble Phenylphosphane to Avoid Interaction with Cyclodextrin
Authors: Ferreira Michel , Bricout Hervé , Sayede Adlane , Ponchel Anne , Fourmentin Sophie , Tilloy Sébastien , Monflier Eric
Published: February 2008

The ability of cyclodextrin to interact with meta‐trisulfonated triphenylphosphane derivatives bearing one or two methyl (or methoxy) groups on the aromatic ring has been investigated by NMR and UV‐vis spectroscopy. In the case of native β‐cyclodextrin (β‐CD), the presence of one methyl or methoxy group in the ortho‐position on each aromatic ring is necessary to hamper the formation of an inclusion complex between the β‐CD and meta‐trisulfonated triphenylphosphane derivatives. In the case of methylated β‐CD, the formation of an inclusion complex is only observed when the meta‐trisulfonated triphenylphosphane contains a methyl group in the para‐position. The poor affinity of methylated β‐CD towards modified trisulfonated triphenylphosphanes was attributed to the steric hindrance generated by the methyl groups on the CD secondary face. The absence or presence of an interaction between phosphanes and methylated β‐CD was also confirmed by catalytic experiments. Thus, the phosphanes that do not interact with the methylated CD were the most efficient mass‐transfer promoters in an aqueous biphasic palladium‐catalyzed Tsuji–Trost reaction.
Mutations in TPM3 are a common cause of congenital fiber type disproportion
Authors: Clarke Nigel F. , Kolski Hanna , Dye Danielle E. , Lim Esther , Smith Robert L. L. , Patel Rakesh , Fahey Michael C. , Bellance Rémi , Romero Norma B. , Johnson Edward S. , Labarre‐Vila Annick , Monnier Nicole , Laing Nigel G. , North Kathryn N.
Published: February 2008

Objective

Congenital fiber type disproportion (CFTD) is a rare form of congenital myopathy in which the principal histological abnormality is hypotrophy of type 1 (slow‐twitch) fibers compared with type 2 (fast‐twitch) fibers. To date, mutation of ACTA1 and SEPN1 has been associated with CFTD, but the genetic basis in most patients is unclear. The gene encoding α‐tropomyosinslow
(TPM3) is a rare cause of nemaline myopathy, previously reported in only five families. We investigated whether mutation of TPM3 is a cause of CFTD.

Methods and Results

We sequenced TPM3 in 23 unrelated probands with CFTD or CFTD‐like presentations of unknown cause and identified novel heterozygous missense mutations in five CFTD families (p. Leu100Met, p.Arg168Cys, p.Arg168Gly, p.Lys169Glu, p.Arg245Gly). All affected family members that underwent biopsy had typical histological features of CFTD, with type 1 fibers, on average, at least 50% smaller than type 2 fibers. We also report a sixth family in which a recurrent TPM3 mutation (p.Arg168His) was associated with histological features of CFTD and nemaline myopathy in different family members. We describe the clinical features of 11 affected patients. Typically, there was proximal limb girdle weakness, prominent weakness of neck flexion and ankle dorsiflexion, mild facial weakness, and mild ptosis. The age of onset and severity varied, even within the same family. Many patients required nocturnal noninvasive ventilation despite remaining ambulant.

Interpretation

Mutation of TPM3 is the most common cause of CFTD reported to date. Ann Neurol 2008
Frequency and course of mild cognitive impairment in a multiethnic community
Authors: Manly Jennifer J. , Tang Ming‐X. , Schupf Nicole , Stern Yaakov , Vonsattel Jean‐Paul G. , Mayeux Richard
Published: February 2008

Objective

To examine incidence rates and antecedents of mild cognitive impairment (MCI) and Alzheimer's disease (AD) among diverse elders without dementia at the initial visit, and to examine the characteristics of elders with MCI who reverted to normal on follow‐up examination.

Methods

A total of 2,364 Caribbean Hispanic, black, or non‐Hispanic white subjects, aged 65 or older, who were free of dementia at initial evaluation were followed up every 18 to 24 months. Incidence rate of MCI and AD was determined by examination of neurological, medical, psychiatric, and neuropsychological function.

Results

Over 10,517 person‐years, 21% of normal elderly subjects progressed to MCI (annual incidence rate, 5.1%; 95% confidence interval, 4.6–5.6%). Of those with MCI initially, 21.8% were subsequently diagnosed with AD (annual incidence rate, 5.4%; 95% confidence interval, 4.7–6.3%), 47% remained unchanged, and 31% reverted to normal. Those with MCI were 2.8 times more likely to experience development of AD than normal elderly subjects. MCI with impairment in memory and at least one other cognitive domain was associated with greatest risk for progression to AD and was also least likely to revert to normal at follow‐up. Consistent diagnosis of MCI or incident probable or possible AD was 60% sensitive and 94% specific for the pathological diagnosis of AD.

Interpretation

Impaired memory and language were useful predictors of transition to AD. Reversion to normal from MCI was frequent, but those with impairment in more than one cognitive domain were more likely to progress or remain impaired than those with single‐domain impairment. Clinical diagnosis of MCI does not always predict AD neuropathology. Ann Neurol 2008
Synthesis and properties of novel Y‐shaped nonlinear optical polymers containing imidazole‐based chromophores
Authors: Pan Yang , Tang Xiaozhen
Published: February 2008

This article describes the synthesis and second‐order nonlinearity study of several new polyphosphazene polymers, which are composed of a new type of nonlinear optical chromophore attached to polyphosphazene. They were obtained via a post‐azo coupling reaction. The resulting materials were characterized with 1H‐NMR, 31P‐NMR, Fourier transform infrared, ultraviolet–visible, gel permeation chromatography, and differential scanning calorimetry. Chromophore contents up to 14 mol % were realized. The polymers had good optical transparency, and poled films revealed resonant d33 values in the range of 18–37 pm/V by second harmonic generation measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Simple route to get very hydrophobic surfaces of fibrous materials with core–shell latex particles
Authors: Nguyen David , Chambon Pierre , Rosselgong Julien , Cloutet Eric , Cramail Henri , Ravaine Serge
Published: February 2008

The aim of this article is to report the creation of artificial, robust, and very hydrophobic materials with core–shell polyurethane–polydimethylsiloxane or polyurethane–poly(n‐butyl acrylate) polymer microparticles. These latexes were prepared by polyaddition in cyclohexane with commercial or synthetic steric stabilizers. An easy one‐step method based on the filtration of the colloidal particles was developed to obtain water‐repellent fibrous materials such as paper or textiles that maintain stable properties even after several washing/drying cycles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal stability and molecular interaction of polyurethane nanocomposites prepared by in situ polymerization with functionalized multiwalled carbon nanotubes
Authors: Jana R. N. , Cho Jae Whan
Published: February 2008

Polyurethane (PU) nanocomposites were prepared through conventional and in situ methods with multiwalled carbon nanotubes (MWNTs) functionalized with poly(ϵ‐caprolactone). The thermal degradation and stability of PU–MWNT nanocomposites were investigated with nonisothermal thermogravimetry and were explained in terms of the interaction between MWNTs and PU molecules with Fourier transform infrared spectroscopy. The difference in thermal stability between the conventional and in situ nanocomposites was also compared. The thermal degradation of all the nanocomposite samples took place in two stages and followed a first‐order reaction. The degradation temperature of the in situ nanocomposites was higher than that of the conventional nanocomposites with the same loading of MWNTs. The activation energy at 10% degradation and the half‐life period were also higher in the in situ nanocomposites compared to the conventional nanocomposites. Such higher thermal stability of the in situ nanocomposites was ascribed to covalent bond formation between MWNTs and PU chains, which could result in better dispersion of MWNTs in the PU matrix for the in situ nanocomposites than for the conventional nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Carbonylative Polymerization of Oxetanes Initiated by Acetyl Cobalt Complexes
Authors: Permana Yessi , Nakano Koji , Yamashita Makoto , Watanabe Daisuke , Nozaki Kyoko
Published: February 2008

Four acetyl cobalt complexes, [AcCo(CO)3P(p‐tolyl)3] (1; p‐tolyl=4‐Me‐C6H4), [AcCo(CO)3P(OPh)3] (2), [AcCo(CO)3P(NMe2)3] (3), and [AcCo(CO)2(dppp)] (4; dppp=1,3‐bis(diphenylphosphanyl)propane), were synthesized, characterized, and examined as catalysts for the unprecedented carbonylative polymerization of oxetanes. Copolymers containing ester (4‐hydroxyalkanoate) and/or ether units were obtained with complexes 1 and 2, but not with complexes 3 and 4 either in the presence or absence of additional phosphorus ligands. The ester unit/ether unit ratio varied in the range 21:79–63:37, and the highest ester/ether ratio of 63:37 was achieved by using complex 1 in the presence of a further 5 equivalents of P(OPh)3. Although direct carbonylative polymerization is possible, preformation and ring opening of the γ‐lactone is also suggested as an alternative pathway.
Population-based study of surgical factors in relation to health-related quality of life after oesophageal cancer resection
Authors: Rutegård M , Lagergren J , Rouvelas I , Lindblad M , Blazeby J M , Lagergren P
Published: February 2008

Background

Oesophagectomy for cancer has a negative impact on health-related quality of life (HRQL), but factors influencing postoperative HRQL have been sparsely studied. This study explored how selected surgical factors affected HRQL 6 months after operation.

Methods

This population-based study was based on a Swedish network of physicians with almost complete nationwide coverage and data on oesophageal cancer surgery collected prospectively between 2001 and 2005. Patients completed validated HRQL questionnaires 6 months after operation. Mean scores with 95 per cent confidence intervals were calculated and clinically relevant differences between groups were analysed in a linear regression model, adjusted for potential confounders.

Results

Some 355 patients were included in the analysis (participation rate 79·6 per cent). Extensive surgery, as indicated by a transthoracic approach, more extensive lymphadenectomy, wider resection margins and a longer duration of operation, was not associated with worse HRQL measures than less extensive operations. Dysphagia was similar in patients who had handsewn and stapled anastomoses. Technical surgical complications had significant deleterious effects on several aspects of HRQL.

Conclusion

This study provides no evidence to suggest that less extensive surgery for oesophageal cancer should be recommended from the perspective of HRQL. It is essential, however, that attention be paid to minimizing technical surgical complications.
Outcome after abdominal aortic aneurysm repair in Sweden 1994–2005
Authors: Wanhainen A , Bylund N , Björck M
Published: February 2008

Background

The aim was to study the epidemiology of abdominal aortic aneurysm (AAA) repair in Sweden.

Methods

Primary AAA repairs registered in the Swedish Vascular Registry between 1994 and 2005 were studied. Mortality data were obtained from the national population registry, and age- and sex-specific populations for each calendar year from Statistics Sweden.

Results

Some 10 691 primary AAA repairs were identified. In the population aged 60 years or over the incidence of intact AAA repair increased from 27·0 per 100 000 in 1994–1999 to 28·8 per 100 000 in 2000–2005 (P = 0·006), while the incidence of surgery for ruptured AAA (rAAA) remained stable (13·8 versus 14·1 per 100 000; P = 0·595). Open repair with a bifurcated graft decreased, whereas endovascular repair (EVAR) increased to 35·0 per cent of intact AAA and 10·3 per cent of rAAA procedures in 2005. Patients who had EVAR were older than those undergoing open repair (74·1 versus 71·9 years; P < 0·001). The 30-day mortality rate decreased over time for intact and ruptured aneurysm operations (P = 0·001). Age, female sex and open repair (compared with EVAR) were independently associated with a higher 30-day mortality rate in a logistic regression model.

Conclusion

The introduction of EVAR was associated with an increasing incidence of intact AAA repair, whereas the rate of rAAA was stable. Perioperative mortality rates decreased over time.
Star‐Shaped Oligobenzoates: Non‐conventional Mesogens Forming Columnar Helical Mesophases
Authors: Lehmann Matthias , Jahr Michael , Donnio Bertrand , Graf Robert , Gemming Sibylle , Popov Igor
Published: February 2008

Star‐shaped mesogens with a phloroglucinol or a trimesic acid core and oligobenzoate arms with up to five repeating units have been synthesised. These non‐conventional mesogens form various columnar mesophases over a broad temperature range. The liquid‐crystal phases were characterised by optical microscopy, differential scanning calorimetry, X‐ray diffraction, dilatometry and solid‐state NMR spectroscopy. In addition to the high‐temperature hexagonal columnar phases, the columnar self‐assemblies undulate upon cooling and consequently form higher‐ordered body‐centred orthorhombic columnar 3D structures. A model of E‐shaped folded conformers helically displaced along the columns is proposed. Helical preorganisation in the hexagonal phase precedes the transition to the low‐temperature phases. Space filling and nano‐segregation compete in the self‐organisation process, thus aliphatic chains and the polar oligobenzoate scaffold are not perfectly separated in these star‐shaped mesogens.
High‐dose melphalan‐based autotransplants for multiple myeloma
Authors: Pineda‐Roman Mauricio , Barlogie Bart , Anaissie Elias , Zangari Maurizio , Bolejack Vanessa , van Rhee Frits , Tricot Guido , Crowley John
Published: February 2008

BACKGROUND

In this report, the authors describe their collective experience with melphalan‐based autotransplants since the inception of their program at the University of Arkansas for Medical Sciences in 1989.

METHODS

The authors evaluated the clinical outcomes of 3077 successive patients with multiple myeloma (MM) who underwent at least 1 melphalan‐based autotransplantation at the University of Arkansas. Of these, 1078 patients were enrolled on front‐line Total Therapy (TT) protocols (TT‐P) TT1, TT2, and TT3; 1104 patients were entered on protocols for newly diagnosed or previously treated patients (non‐TT‐P); and 895 patients were treated off protocol (non‐P).

RESULTS

The 10‐year overall survival (OS) rates after first transplantation were 41%, 19%, and 11% (P< .001) for the TT‐P, non‐TT‐P, and non‐P groups, respectively. In the TT‐P group, the median OS was 72 months on TT1, was not reached at ≥7 years on TT2, and was 88% at 2 years on TT3. Among 2683 patients with complete baseline data, absence of hypodiploidy/chromosome 13 deletion, β‐2‐microglobulin <3.0 mg/L, C‐reactive protein <6 mg/L, albumin ≥3.0 g/dL, and platelet count ≥100,000/μL all were associated independently with superior OS (P< .001), event‐free survival (P< .001), and duration of complete remission (P< .001).

CONCLUSIONS

The results from this large, single‐institution experience demonstrated that >10‐year OS was accomplished in >40% of all patients enrolled on TT‐P, whereas such success was observed in only 15% of the remaining patients (including 25% in the presence of all 5 good‐risk features). Superior outcomes with protocol‐based, primary transplant regimens such as TT‐P draw attention to the importance of applying the best available therapies upfront. Cancer 2008. © 2008 American Cancer Society.
Double‐blind, placebo‐controlled, randomized study of chlorhexidine prophylaxis for 5‐fluorouracil‐based chemotherapy‐induced oral mucositis with nonblinded randomized comparison to oral cooling (cryotherapy) in gastrointestinal malignancies
Authors: Sorensen Jens Benn , Skovsgaard Torben , Bork Ellen , Damstrup Lars , Ingeberg Sten
Published: February 2008

BACKGROUND

The purpose was to evaluate prevention of oral mucositis (OM) using chlorhexidine compared with placebo and with oral cooling (cryotherapy) during fluorouracil (5‐FU)‐based chemotherapy in gastrointestinal (GI) cancer.

METHODS

Patients with previously untreated GI cancer receiving bolus 5‐FU/leucovorin chemotherapy were randomized to chlorhexidine mouthrinse 3 times a day for 3 weeks (Arm A), double‐blind placebo (normal saline) with the same dose and frequency (Arm B), or cryotherapy with crushed ice 45 minutes during chemotherapy (Arm C). Patients self‐reported on severity (CTC‐grading) and duration of OM.

RESULTS

Among 225 patients randomized, 206 answered the questionnaire (70, 64, and 63 patients in Arms A, B, and C, respectively) and were well balanced with respect to diagnoses, stage, age, sex, smoking habits, and performance status. Mucositis grade 3–4 occurred more frequently in Arm B (33%) than in A (13%, P < .01) and C (11%, P < .005). Duration was significantly longer in B than in both A (P = .035) and C (P = .003).

CONCLUSIONS

The frequency and duration of OM are significantly improved by prophylactic chlorhexidine and by cryotherapy. The latter is easy and inexpensive but has limited use, as it is drug‐ and schedule‐dependent. The current study is the first double‐blind randomized evaluation of prophylactic chlorhexidine in a large adult patient population with solid tumors receiving highly OM‐inducing chemotherapy. A role for chlorhexidine in the prevention of OM is suggested, which should be evaluated further. Cancer 2008. ©2008 American Cancer Society.
Local environmental influences on uveal melanoma
Authors: Canovas David , Rennie Ian G. , Nichols Carmel E. , Sisley Karen
Published: February 2008

BACKGROUND

Uveal melanomas of the choroid and ciliary body are aggressive tumors causing the death of approximately 50% of patients. In contrast, iris melanomas only infrequently metastasize; why these differences exist is not known. The local environment can regulate cancer growth and development, and it is probable the aqueous and vitreous humors have an important role in regulating uveal melanoma behavior.

METHODS

To explore this possibility cultures of uveal melanoma were exposed to aqueous and vitreous and the effects investigated using invasion and proliferation assays. ChemiArrays (Chemicon International, Temecula, Calif) were performed to determine which regulatory factors might influence the process.

RESULTS

The vitreous universally promoted uveal melanoma invasion, whereas the aqueous mainly had no effect or was inhibitory. Tumor location, and the baseline invasion of the melanoma, affected the ability of aqueous and vitreous from different patients to regulate invasive behavior. Proliferation was not significantly altered as a result of exposure to the aqueous or vitreous. The ability of the humors to regulate uveal melanomas may involve TIMP‐2, TIMP‐3, and TGF‐β2, as high expression was found by ChemiArray analysis and there were differences in the levels of the regulators in the aqueous compared with the vitreous.

CONCLUSIONS

The findings suggest that in situ uveal melanoma development reflects an interaction between the tumor and the environment of the eye. Exposure to the aqueous would therefore contribute to the benign nature of iris melanomas, whereas potential interaction with the vitreous appears to promote the aggressive behavior of posterior uveal melanomas. Cancer 2008. © 2008 American Cancer Society.