bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Contact Gait in the Cadaveric Lower Extremity using a Novel Below Knee Simulator
Authors: Iaquinto Joseph , Adelaar Robert S. , Wayne Jennifer S.
Published: February 2008

Background: Research into gait characteristics has led to the creation of experimental gait simulators. The aim of this work was the development of a Contact Gait Simulation System (CGSS) to generate realistic plantar pressures for the contact phase of gait. The simulator seeks to create muscle loads which guide the foot through the entire loaded contact phase. Methods: Two simulations, mid stance only ( n = 8) and full contact gait ( n = 7) were applied to cadaveric lower extremities disarticulated at the knee. The Achilles, extensor digitorum, and extensor hallucis longus tendons were clamped for the application of muscular loads while axial loads were applied to the proximal tibia and plantar pressures were measured. Live subjects ( n = 7) were recorded traversing the plantar pressure sensor, for regional (fore, mid, and hind foot) pressure comparisons. Results: By loading muscle tendons in proportion to live gait, the generated patterns of loading across the fore, mid and hind foot were representative of that found in live subjects. Hindfoot pressures dominated during the initial loading response, while forefoot pressures dominated during the terminal stance phase of gait. Regional trends showed strong similarity in timing and proportion to live gait. Conclusions: The CGSS developed is capable of simulating live plantar pressures in the cadaveric model. Further manipulation of simulator control signals may improve accuracy, but as gait characteristically exhibits broad trends, exact agreement is not necessary. Clinical Relevance: We believe this System can be used to efficiently investigate the alterations to foot/ankle function resulting from injuries and surgical corrective procedures.
Morphometrical Features of the Human Malleolar Groove
Authors: Ozbag Davut , Gumusalan Yakup , Uzel Murat , Cetinus Ercan
Published: February 2008

Background: Our aim was to investigate the morphometric features of malleolar groove of the lateral malleolus in humans. Methods: This study was performed on the malleolar grooves of 93 (80 dry and 13 cadaveric) fibulae. We measured the length of the fibula; length, width, and depth of the malleolar groove; the angle between malleolar groove and the fibular axis. Furthermore, we measured the distances between the distal tip of the fibula and the lateral and medial tubercles of lateral malleolus, and the width of posterior surface of the lateral malleolus. Results: We found the shape of malleolar groove regularly concave in 63 out of 93 (68%) fibulae. The features of the triangular area at the posterior aspect of the lateral malleolus, where the peroneal tendons pass over, may serve as a bed for the peroneal tendons. There was a significant correlation between the depth of the malleolar groove and the distances between the distal tip of the fibula and the medial and lateral tubercles, as well ( p < 0.05). Conclusion: A strong correlation existed between either the shape of the groove or the values of the reference points. Clinical Relevance: The shape of the groove may be important in reinforcing the superior peroneal retinaculum (SPR) and other structures restraining the tendons.
A Review of Family Meal InfluenceOn Adolescents’ Dietary Intake
Authors: Woodruff Sarah J. , Hanning Rhona M.
Published: February 2008

Recent concerns about adolescent nutrition and unhealthy weights have prompted an examination of the myriad influences on dietary intake during adolescence. Included here are a summary of the literature on family influence on dietary intake, specifically during adolescence and within the family context, a summary of family meal patterns, and a systematic review of the known influences of family meals on dietary intake. Because of the complexity of families in today’s society, models were developed to depict the broad context of familial influences on adolescent nutritional behaviours and attitudes and to describe what is known and not known about family meal influences on adolescent dietary intake and quality. A systematic review of the literature revealed seven articles specifically related to adolescents, family meals, and dietary intake, which were analyzed for strength of evidence and plausibility. In spite of data collection methods relying on self-report, results suggested that family meals were associated with improved dietary intakes. Families in today’s societies are complex. Nevertheless, parents have the potential to influence positively, through family meals, what food is provided, where it is provided (e.g., home, restaurant), and within what type of atmosphere it is provided.
Moderate Weight Loss: A Self-directed Protocol for Women
Authors: Santosa Sylvia , Demonty Isabelle , Jones Peter J.H. , Lichtenstein Alice H.
Published: February 2008

This innovative, self-directed diet and physical activity program was designed to achieve moderate weight loss in women. Thirty-five overweight or obese hyperlipidemic women completed a 20-week weight loss study. The weight loss intervention consisted of a 20% decrease in energy intake through diet and a 10% increase in energy expenditure through physical activity. The diet consisted of 50-60% carbohydrates, 20% protein, and 20-30% fat. A personal trainer prescribed physical activity regimens. A progress-tracking system and monthly group sessions were used to maintain participant motivation throughout the weight loss period. Participants lost an average of 11.7 ± 2.5 kg (p<0.001). The pattern of weight loss was linear (p<0.001) throughout the study period. Average weight loss per week was 0.59 ± 0.55 kg. This 20-week program, combining a structured self-selected diet and independent preplanned physical activity with motivational strategies, resulted in weight loss comparable to that observed in more controlled interventions. The lower cost, ease of use, and outcome success make this approach potentially useful in a clinical setting.
Dietitians’ Attitudes, Perceptions, and Usage Patterns For Fresh-cut Fruit and Vegetables
Authors: Sanford Katherine A. , Johnston Elizabeth M. , Porter Jennifer L. , Lowe Judith , Oxby Debra M.
Published: February 2008

Purpose: New fresh-cut fruit and vegetable products are being developed worldwide. Nutrition educators’ perceptions of these products were studied.

Methods: Professional dietitians in Nova Scotia were asked to complete a questionnaire on their use of fresh-cut produce. The questionnaire also elicited their attitudes and perceptions about the convenience, taste/quality, nutrition/health benefits, cost, and safety of fresh-cut fruit and vegetables.

Results: Sixty-three percent of respondents reported eating five to six servings of fruit and vegetables a day. This group most frequently consumed fresh-cut fruit as snacks or dessert, and vegetables in stir-fry dishes or salads or cooked with meals. In general, fresh-cut fruit and vegetables were perceived as convenient, safe, and nutritious. While approximately 50% of participants felt fresh-cut produce did not differ in taste from whole fresh produce, almost the same number considered whole fresh produce superior in taste.

Conclusions: Dietitians have a generally positive perception of fresh-cut products; however, there is uncertainty about the nutritional value, cost/benefit, and use of the products. Dietitians require more information on the nutrient value of these products and on suggested alternative uses. Attention should be paid to developing fresh-cut products that have good sensory quality.
Registration of ‘Ripper’ Wheat
Authors: Haley Scott D. , Johnson Jerry J. , Peairs Frank B. , Quick James S. , Stromberger John A. , Clayshulte Sally R. , Butler Joshua D. , Rudolph Jeff B. , Seabourn Bradford W. , Bai Guihua , Jin Yue , Kolmer Jim
Published: February 2008

‘Ripper’ (Reg. No. CV‐1016, PI 644222) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2006 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State University, USDA‐ARS researchers in Manhattan, KS, and St. Paul, MN, participated in the development of Ripper. Ripper was selected from the cross CO940606/TAM107R‐2 made in 1996 at Fort Collins, CO. CO940606 is an unreleased sib‐selection of KS94WGRC29 (PI 586954), a germplasm release from Kansas State University with the pedigree PI 220127/P5//‘TAM‐200’/KS87H66, while TAM107R‐2 is an unreleased sib‐selection of the hard red winter wheat cultivar Prairie Red (PI 605390). Ripper was selected as an F3:4 line (F3–derived line in the F4 generation) in 2000 and assigned experimental line number CO00016. Ripper was released because of its superior grain yield performance under nonirrigated production in eastern Colorado and superior milling and bread‐baking quality.
Registration of ‘Osage’ Soybean
Authors: Chen P. , Sneller C.H. , Mozzoni L. A. , Rupe J. C.
Published: February 2008

‘Osage’ soybean [Glycine max (L.) Merr.] (Reg. No. CV‐495, PI 648270) was developed and released by the Arkansas Agricultural Experiment Station as a Maturity Group V conventional cultivar in March 2007. It was derived from the cross ‘Hartz 5545’ × ‘KS4895’ and has been evaluated in 130 field tests in several southern states. Osage is widely adapted to areas between 33 and 37°N latitude and has high yield potential and moderately high protein content. Overall, when grown in southern environments, Osage had seed yield 3.2% greater than the check ‘5601T’ and 3.3% greater than the check ‘5002T’. Seed protein of Osage is 3.1% and 5.4% greater than 5601T and 5002T, respectively. Osage is resistant to several important diseases in the Mid‐South USA, including southern stem canker, sudden death syndrome, soybean mosaic virus, and frogeye leaf spot.
Overview of Modern Analytical Needs
Authors: Davis Frank , Collyer Stuart D. , Higson Séamus P. J.
Published: February 2008

This review aims to introduce and cover some of the requirements of today's analytical chemists and biochemists together with a number of techniques that are being applied to satisfy these demands. The wide variety of analytes for which reliable detection methods are required are discussed initially. This is followed by a basic introduction to a variety of detection methods such as electrochemical approaches, fluorescence‐based techniques, and the quartz crystal microbalance. This is followed by a section covering techniques that are designed for analyses using very small samples such as lab‐on‐a‐chip type measurements and microfluidic devices. The next section contains more detailed information on analyses for specific analytes such as DNA. The use of array technology to perform many simultaneous measurements and the application of this to the growing fields of genomics and proteomics is also presented. Conclusions and a future outlook for these systems are finally discussed.
Luciferase Reporter Bacteriophages
Authors: Hagens Steven , Loessner Martin J.
Published: February 2008

Reporter bacteriophages harness the biological specificity of the interaction between bacterial cells and their bacteriophages. The use of phages that have been genetically engineered to carry luciferase genes which provide an easily quantifiable signal upon infection represents a highly specific means for the detection of viable bacteria. Luciferases of different origin can be used, in conjunction with phages infecting a variety of different pathogenic microorganisms. This chapter aims to describe the biology behind the approach and summarizes the current standing with respect to the various luciferase reporter phages and their applications.
Recombinant Whole‐Cell Bioreporter Systems Based on Beetle Luciferases
Authors: Ivask Angela , Kahru Anne , Virta Marko
Published: February 2008

Bioluminescence is one of the most widely used reporter systems in living cells. Luciferase encoded by
luc
gene from the firefly
Photinus pyralis
is a commonly used reporter gene that can be detected by bioluminescence and utilized in the construction of bioreporters. In a classical bioreporter, the expression of a reporter gene is controlled by a natural regulatory circuit, which in many cases consists of a regulatory protein and its corresponding promoter. In the absence of analyte, the regulatory protein is either repressing the transcription initiation from the corresponding promoter or simply does not activate the transcription. However, when the analyte is present in the bioreporter cells, it binds with the regulatory protein, which initiates the transcription and thus, the expression of the reporter gene, the specificity of a bioreporter, is mostly defined by the regulatory unit.

An overview is given on the possibilities and limitations of beetle luciferases in whole‐cell bioreporter systems and biosensors. Examples of the use of beetle luciferase‐based bacterial and yeast‐based bioreporter systems for the quantification of bioavailable heavy metals and organic compounds in environmental samples as well as for identifying endocrine disruptive compounds are given.
Molecularly Imprinted Polymers as Recognition Elements in Sensors
Authors: Haupt Karsten , Belmont Anne‐Sophie
Published: February 2008

The technique of molecular imprinting allows for the formation of specific recognition sites in synthetic polymers through the use of templates or imprint molecules. These recognition sites mimic the binding sites of biological receptor molecules such as antibodies and enzymes. Molecularly imprinted polymers can therefore be used in applications based on specific molecular binding events, such as, assays and sensors. The stability, ease of preparation, and low cost of these materials make them particularly attractive. This review focuses on recent developments and advances in the field with special emphasis on the use of molecularly imprinted materials as recognition elements in sensors and their interfacing with the transducer.
Ion Channel Biosensors
Authors: Cornell Bruce A.
Published: February 2008

Ion channel switch biosensors detect the presence of target molecules from changes in the ac ionic conduction of a tethered membrane containing ion channels. The membranes comprise one or more lipid layers and are tethered to an electrical conductor such as gold. Modulation of the ionic conductance of the membrane induces a change in the image charge at the gold surface resulting in a current flow in an external circuit. The magnitude of these changes is greatly increased by separating the membrane from the metal surface using a hydrophilic spacer. A generic immunosensing device has been devised in which the ion channel, gramicidin A has been incorporated into a tethered lipid membrane and coupled to an antibody that is targeted to a compound of diagnostic interest. Quantitative detection of an extensive class of target species, including proteins, bacteria, drug and toxins has been demonstrated. By using DNA probes, DNA sequences have also been detected. In this review results are presented of multianalyte sensing using silicon chip arrays decorated using “ink‐jet” printing to apply antibodies to specific sites in the array. Also reviewed are scale‐up issues such as reproducibility over extended periods of sensor fabrication and of sources of instability on storage.
Electrochemical Techniques in Biosensors
Authors: Arya Sunil K. , Singh Surinder P. , Malhotra Bansi D.
Published: February 2008

Recent progress in biosensors has resulted because of the extensive applications of electroanalytical tools. The present chapter deals with the description of electrochemical techniques in general and electrochemical biosensors in particular.
Overview of Optical Biosensing Techniques
Authors: Abdulhalim Ibrahim , Zourob Mohammad , Lakhtakia Akhlesh
Published: February 2008

Commonplace optical biosensing techniques include the classical techniques of optical spectroscopy, polarimetry, and ellipsometry, in addition to more modern techniques such as surface plasmon resonance and guided waves. Currently state‐of‐the‐art techniques under extensive investigation include whispering‐gallery waves and surface‐enhanced optical phenomena near metallic nanoparticles. A succinct overview of the fundamentals of these techniques accompanies remarks on commercial successes and research accomplishments.
Phagocyte Luminescent Sensor
Authors: Magrisso Moni , Marks Robert S.
Published: February 2008

The article describes basics of approach to build a device dedicated to sensitive assessment of phagocyte activity in biological fluids. The unique place of phagocytosis in the innate immune system, the mechanisms, localization and factors of oxidative phagocyte activity as well as the techniques used to detect respiratory burst and localization are briefly reviewed. Sensor design combines simplicity and artifact ‐absence in whole blood system, simultaneous record and analysis of extra‐cellular and intra‐cellular luminescence, sensitivity and efficiency of signal capturing of optical fiber–photomultiplier detection system and the convenience of disposable sample holder.
Introduction to Acoustic Technologies
Authors: Araya‐Kleinsteuber Bernardita , Lowe Christopher R.
Published: February 2008

This chapter gives an introduction to acoustic technologies, particularly focused on how acoustic waves are generated in piezoelectric crystals and how that can be used for the development of biosensors. Secondly, a detailed explanation of the fabrication of acoustic wave devices is given, including materials used for construction and vibration modes of different devices. Thirdly, the most common types of acoustic sensors are described—quartz crystal microbalance, acoustic plate wave devices, surface wave sensors, and flexural plate wave devices. Also, for the quartz crystal microbalance a detailed description of the physical models developed to quantify the mass loading from the acoustic response is presented. Finally, a brief account of the acoustic sensors applications is presented, both industrial and in the biosensing arena.
Magnetic Biosensor Techniques
Authors: Marrows Christopher H.
Published: February 2008

The use of various microscale magnetometers to detect magnetic nanoparticles that label biochemical cargoes is reviewed. These include sensors based on superconducting quantum interference devices (SQUIDs), the Hall effect, and various magnetoresistive effects. The most commonly reported of these in the literature is a sensor based on the giant magnetoresistance (GMR) effect, and some emphasis is placed on this method in this review. The basic requirements for the magnetic labels themselves are discussed, and some of the methods developed for magnetically driving biochemical cargoes around a chip surface are described. Finally some prospects for the future are given.
Introduction to Microfluidic Techniques
Authors: Weigl Bernhard H. , Bardell Ron L. , Cabrera Catherine
Published: February 2008

This chapter provides an introduction to concepts of microfluidics and microfluidic design. First, terms are defined and basic fluid dynamic relationships are introduced. Physical aspects and design consequences of working with fluid flow at the microscale are described. Then, the determination of the preferred scale for various applications of microfluidic devices is discussed. Finally, various kinds of fluid flow typical of microdevices are described in more detail, including gravity‐ and pressure‐driven flow, flow through packed media, electrokinetic flow, capillary‐driven flow, and absorption‐driven flow.
Micro‐ and Nanoelectromechanical Sensors
Authors: Aubin Keith L. , Ilic Bojan , Craighead Harold G.
Published: February 2008

This chapter highlights the use of micro‐ and nanoscale mechanical devices whose mechanical properties are being used to create biological sensors. One aim is to provide tools and improvements upon current methods for biological and biomedical research. Currently used biosensors such as enzyme‐linked immunosorbent assays (ELISA) assays, though quite sensitive, have several drawbacks and resist miniaturization. The research highlighted in the chapter may provide alternative measurement techniques that readily lend themselves to miniaturization and portability. The ultimate goal of much of this research is to provide inexpensive, portable sensors that rival or surpass present techniques with regard to sensitivity.
Microarray Analysis Software and its Applications
Authors: Bessant Conrad
Published: February 2008

This chapter describes generic approaches for the analysis of data from sensor arrays, using gene expression microarrays as an example. The two main areas covered are the image analysis processes used to read data from an array and the multivariate analysis techniques used to allow biological interpretation of the data acquired.
Biosensors for Monitoring Metabolites in Clinical Medicine
Authors: Pickup John C.
Published: February 2008

Biosensors for small‐molecular‐weight metabolites are finding increasing use in medicine for rapid, reagentless point‐of‐care measurement and continuous in vivo monitoring. Though glucose is the most well‐established clinical biosensor application, others include urea and creatinine for assessing renal function; lactic acid for monitoring tissue oxygenation; uric acid for assessing nucleic acid metabolism; cholesterol, triglyceride, and ketones for monitoring lipid metabolism; and bilirubin for liver and blood disorders. Many metabolite biosensors are enzyme electrodes, based on immobilized oxidases, hydrolases, or other enzymes, with amperometric or potentiometric electrochemical reaction monitoring, but other bioreceptors such as computer‐designed proteins and other reaction detection methods such as fluorescence are in use.
Biacore—Creating the Business of Label‐Free Protein‐Interaction Analysis
Authors: Löfås Stefan
Published: February 2008

The chapter describes the story of Biacore AB and its development of commercial optical biosensor instruments based on surface plasmon resonance (SPR) detection. Background reasons are given for the starting of this venture, as well as a technical overview of the basic aspects of the instruments, in particular, the core technologies–optical detection, surface chemistry, and microfluidic sample handling. Recent developments and the progress of the technology, application areas, and new instruments are also reviewed. The commercial aspects from the first instrument launch in 1990 through to what became a successful business are described, including the importance of identifying applications with significant commercial relevance.
Basis of metamemory judgments for text with multiple‐choice, essay and recall tests
Authors: Maki Ruth H. , Willmon Cynthia , Pietan Amy
Published: February 2008

Accuracy of metamemory for text was compared for multiple‐choice, essay and recall tests. Essay and recall tests were scored with Latent Semantic Analysis (LSA), number of correct idea units and number of word matches. Each measure was correlated with college students' predictions and posttest confidence judgments across texts to determine metamemory accuracy. Metamemory accuracy varied for different types of tests with multiple‐choice tests generally producing greater accuracy than essay tests. However, metamemory accuracy for essay and recall tests depended on the measure used to score them. Number of correct idea units produced the highest metamemory accuracy, word matches produced an intermediate level, and LSA produced the lowest accuracy. Students used the quantity of output in their judgments, so performance measures that related most strongly to quantity matched judgments better than measures based on answer quality. The results are compatible with an accessibility account of judgments about performance on text. Copyright © 2008 John Wiley & Sons, Ltd.
Piecewise MILP under‐ and overestimators for global optimization of bilinear programs
Authors: Wicaksono Danan Suryo , Karimi I. A.
Published: February 2008

Many practical problems of interest in chemical engineering and other fields can be formulated as bilinear programs (BLPs). For such problems, a local nonlinear programming solver often provides a suboptimal solution or even fails to locate a feasible one. Numerous global optimization algorithms devised for bilinear programs rely on linear programming (LP) relaxation, which is often weak, and, thus, slows down the convergence rate of the global optimization algorithm. An interesting recent development is the idea of using an ab initio partitioning of the search domain to improve the relaxation quality, which results in a relaxation problem that is a mixed‐integer linear program (MILP) rather than LP, called as piecewise MILP relaxation. However, much work is in order to fully exploit the potential of such approach. Several novel formulations are developed for piecewise MILP under‐ and overestimators for BLPs via three systematic approaches, and two segmentation schemes. As is demonstrated and evaluated the superiority of the novel models is shown, using a variety of examples. In addition, metrics are defined to measure the effectiveness of piecewise MILP relaxation within a two‐level‐relaxation framework, and several theoretical results are presented, as well as valuable insights into the properties of such relaxations, which may prove useful in developing global optimization algorithms. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Novel anticorrelation criteria for model‐based experiment design: Theory and formulations
Authors: Franceschini Gaia , Macchietto Sandro
Published: February 2008

Model‐based experiment design techniques are becoming an essential tool for the rapid development and refining of process models. One of the areas where an effective design can be most useful is the identification of the kinetic parameters of a model. When complex kinetic networks (i.e., parallel, consecutive reactions) are involved, parameter correlations play a significant role because they often prevent the solution of experiment design calculations, make parameter identification more difficult, and decrease the statistical validity of the resulting models. It is therefore important to obtain estimates of the parameters as uncorrelated as possible and this article presents new optimal experiment design criteria that include explicit measures of correlation as objective function or as constraints and are able to target the experiments to the improvement of specific parameter(s). Through an illustrative application to an epoxidation example, the new approach proposed is demonstrated to be very successful, highly flexible, and more effective than the standard experiment design criteria in both reducing the uncertainty regions of the parameters and improving the reliability of the estimates. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Effect of chemical heterogeneity on adsorbed solute dispersion at column scale
Authors: Semra Safia , Sardin Michel , Simonnot Marie‐Odile
Published: February 2008

Chemical heterogeneity seems to be responsible for spreading increase of adsorbed solute breakthrough curves. Adsorption in fixed beds assumes chemically homogeneous media. However, this is not always true, in particular when natural sands or mixed adsorbent filters are used in drinking water purification. Neglecting eventual effect of chemical heterogeneity may engender false modeling bases. So, considering homogeneous grain size distribution, the effect of chemical heterogeneity on global dispersion in porous media has been investigated experimentally in this article at column scale. Breakthroughs of adsorbed solute showed a visible effect of chemical heterogeneity on solute global dispersion increasing. The more heterogeneous the medium, the more spread the adsorbed solute breakthrough. Reduced variance showed a linear variation with the chemical heterogeneity scale at closely constant media global capacity. A pseudo‐homogeneous model has been developed to simulate experimental data by increasing dispersion parameter. © 2008 American Institute of Chemical Engineers AIChE J, 2008
On bubbles rising through suspensions of solid particles
Authors: Mondy Lisa A. , Retallack Charles , Thompson Kyle , Barney Jeremy , Grillet Anne , Graham Alan L.
Published: February 2008

Individual bubbles rising through suspensions of spherical particles neutrally buoyant in viscous Newtonian liquids are tracked with real time radiography. The effects of the containing cylinder, suspended particle, and bubble sizes are reported for particle volume fractions ranging from 0.20 to 0.50. In the most concentrated suspensions, the effect of the bottom surface is felt by the bubble much farther into the suspension than would be true for a single‐phase Newtonian liquid. Corrected for wall effects, the apparent viscosity felt by the bubbles is independent of the relative size of the bubble to the particle over a wide range of parameters, and is approximately linear with the suspended particle volume fraction, in contrast to the exponential dependence derived in conventional rheometry. Finally, in the most concentrated suspensions, the bubble deforms to a prolate spheroidal shape despite the lack of significant inertial effects or a viscoelastic suspending liquid. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Semibatch RAFT polymerization for producing ST/BA copolymers with controlled gradient composition profiles
Authors: Sun Xiaoying , Luo Yingwu , Wang Rui , Li Bo‐Geng , Zhu Shiping
Published: February 2008

With controlled/living radical copolymerization, the composition profile along polymer chains becomes a tunable parameter in preparing copolymer products for novel materials properties. In this work, a novel series of styrene/butyl acrylate (St/BA) copolymers with precisely designed composition profiles (uniform, linear gradient, tanh gradient, and triblock with a linear gradient mid‐block) were produced using a semibatch reversible addition‐fragmentation chain transfer copolymerization mediated by benzyl dithioisobutyrate. The comonomer feeding rate was programmed based on a kinetic model with the targeted composition profile as an objective functions. The experimental composition and molecular weight profiles agreed very well with the model predictions. The polymer molecular weight distributions were narrow with polydispersity index values about 1.3. The amount of dead chains was controlled below 10%. The glass transition behaviors of the St/BA copolymers were evaluated and their Tg values were found to be in an order of uniform < linear gradient < tanh gradient < triblock with 10°C for uniform and 140°C for triblock copolymers. © 2008 American Institute of Chemical Engineers AIChE J 2008
A girl with fragile X premutation from sperm donation
Authors: Wirojanan Juthamas , Angkustsiri Kathleen , Tassone Flora , Gane Louise W. , Hagerman Randi J.
Published: February 2008

We present a girl with the fragile X premutation who obtained the premutation allele from donated sperm. Our patient has clinical characteristics of fragile X syndrome including emotional problems and neuropsychological difficulties presenting as learning disabilities. She is also at high risk for premature ovarian failure and low risk for the fragile X‐associated tremor ataxia (FXTAS). We suggest fragile X DNA screening in gamete donor candidates to decrease the chance of fragile X involvement in their offspring. © 2008 Wiley‐Liss, Inc.
Autism and serotonin transporter gene polymorphisms: A systematic review and meta‐analysis
Authors: Huang Christine H. , Santangelo Susan L.
Published: February 2008

The serotonin transporter gene (5‐HTT) plays a crucial role in serotonergic neurotransmission and has been found to be associated, with varying degrees of significance, with many diseases, including autism. Prior association studies of autism have yielded conflicting results regarding the association between two common 5‐HTT polymorphisms, the promoter insertion/deletion (5‐HTTLPR) and the intron 2 VNTR (STin2 VNTR). We conducted a systematic review and meta‐analysis to test the following hypotheses: (i) there is an association between autism and either or both of the 5‐HTTLPR and STin2 VNTR polymorphisms, and (ii) the S allele of 5‐HTTLPR and/or the STin2.12 allele of the VNTR are the specific risk alleles for autism. All published family‐based and population based studies were examined to determine the overall strength of association between 5‐HTT polymorphisms and autism. After exclusion of studies with overlapping samples and studies whose data did not allow for calculation of an odds ratio, 16 studies were included for final analyses, all but two of which used a family‐based design. The meta‐analysis failed to find a significant overall association between either of the 5‐HTT polymorphisms examined and autism. Further, no allelic transmission distortion was found when studies of simplex (11 studies) and multiplex (3 studies) family samples were analyzed separately. However, there was significant heterogeneity by ethnicity; family based studies of US mixed population samples showed preferential transmission of the S allele of 5‐HTTLPR (S allele:L allele = 247:183), while there was no allelic distortion among the family‐based studies of European and Asian samples. © 2008 Wiley‐Liss, Inc.
Electroless nickel plating of polyester fiber
Authors: Jiang S. Q. , Kan C. W. , Yuen C. W. M. , Wong W. K.
Published: February 2008

The optimization of the electroless nickel plating process used for textile applications was investigated with the orthogonal array testing strategy. It was found that the electroless nickel plating process conducted at 40°C and pH 10 for 20 min was the most effective method for improving the metal adhesion performance. The performance of nickel‐plated polyester fabrics was confirmed to be dependent on the amount of nickel particles adhering to the fabric surface. The properties of the optimized nickel‐plated polyester were enhanced in terms of the fabric weight, fabric thickness, and tensile strength. However, there was a moderate decrease in the tearing strength and crocking fastness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of cationic starch: An efficient flocculating agent
Authors: Pal Sagar , Mal D. , Singh R. P.
Published: February 2008

Starch is a known carbohydrate in which, regardless of its origin, two polysaccharides are found namely amylose and amylopectin. By insertion of a cationic moiety to the backbone of starch, a modified cationic starch can be developed which can be used as flocculant. Various grades of cationic starches were developed to optimize the best performing flocculant. The base polysaccharide, starch and the best performing cationic starch i.e., Cat St3 (which have been confirmed from flocculation characteristics and intrinsic viscosity measurement) have been characterized by various characterization techniques such as determination of molecular weight, elemental analysis, FTIR spectroscopy, intrinsic viscosity measurement, thermal analysis, etc. From the characterization, it could be concluded that there was a substantial incorporation of cationic moiety onto the backbone of starch. The flocculation efficacy of these cationized starches was compared with each other and with some of the commercial flocculants available in national and international market in manganese ore suspensions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Molecular weight distribution broadening of polypropylene by periodic switching of hydrogen and catalyst additions
Authors: Ali M. Al‐Haj , Stroomer J. , Betlem B. , Weickert G. , Roffel B.
Published: February 2008

This study presents a feasibility study of the broadening of the polypropylene molecular weight distribution produced using a multisite Ziegler‐Natta catalyst in a continuous liquid‐pool polymerization reactor. The broadening is achieved by operating the reactor under periodic forcing of both hydrogen and catalyst feed flows. Model‐based dynamic optimization is used to determine the cycle period and peak width for these inputs. Through simulation it is shown that limited widening (∼ 30%) of the molecular weight distribution can be achieved in case of a limited removal of hydrogen from the reactor. The results also show that the forced removal of hydrogen from the reactor could potentially double the polydispersity index of the produced polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improvement of the conductivity, electroactivity, and redoxability of polythiophene by electropolymerization of thiophene in the presence of catalytic amount of 1‐(2‐pyrrolyl)‐2‐(2‐thienyl) ethylene (PTE)
Authors: Kiani G. R. , Arsalani N. , Hosseini M. G. , Entezami A. A.
Published: February 2008

The electropolymerization of thiophene in the presence of 1‐(2‐pyrrolyl)‐2‐(2‐thienyl) ethylene (PTE) was investigated. PTE was synthesized via Wittig reaction and by the addition of catalytic amount of PTE during the electropolymerization of thiophene, the conditions of electropolymerization of thiophene were modified. The cyclic votammograms of polythiophenes (PThs) in different conditions were obtained. The analysis of cyclic votammograms of PThs shows a considerable increase in the electroactivity and redoxability when the electropolymerization of thiophene in the presence of catalytic amount of PTE was performed. The presence of PTE during electropolymerization of thiophene leads to an increase in the rate of polymerization too. The cyclic voltammetry (CV) measurement of electron transfer ferro/ferricyanide redox system on different modified glassy carbon (GC) electrode has shown that the rate of charge transfer for PTh in the presence of PTE increased in comparison to pure PTh. The conductivity of obtained polymers was determined by electrochemical impedance spectroscopy (EIS) technique in 3.5% (w/v) NaCl solutions. The Zview(II) software was applied to the EIS to estimate the parameters of the proposed equivalent circuit, based on a physical model for the electrochemical behavior of coatings on GC. The Rct value obtained for PTh is 7667 Ω cm2. This value decreases in the presence of PTE to 4437 Ω cm2. Thus, the new film has more conductivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structure and properties of tailor‐made poly(ethyl acrylate)/clay nanocomposites prepared by in situ atom transfer radical polymerization
Authors: Datta Haimanti , Singha Nikhil K. , Bhowmick Anil K.
Published: February 2008

An in‐depth study was carried out on the structure and properties of a series of poly(ethyl acrylate)/clay nanocomposites prepared by in situ atom transfer radical polymerization (PNCIs) with well‐defined molecular weights and narrow molecular weight distributions. Wide‐angle X‐ray diffraction and transmission electron microscopy studies revealed an exfoliated clay morphology, whereas conventional solution blending generated an intercalated structure. The storage moduli of the PNCIs showed a moderate increase over that of the neat polymer [poly(ethyl acrylate)]. The sample containing 4 wt % clay (PNCI4, where the number following PNCI indicates the weight percentage of clay) exhibited the highest improvement (31.9% at 25°C). In PNCIs, the β‐transition temperature showed a remarkable decrease (by 175% in PNCI4) along with a shift toward higher temperatures. This indicated the probability of the anchoring of the OH group of the clay layers to the >CO group of the pendant acrylate moiety, which was also confirmed by Fourier transform infrared analysis. Rheological measurements indicated a significant increase in the shear viscosity [by 9% in PNCI2, 15% in PNCI4, and 6% in the poly(ethyl acrylate)/clay nanocomposite with 2 wt % clay prepared by solution blending]. The PNCIs registered enhanced thermal stability, as indicated by the shift in the peak maximum temperature (388 and 392°C for the neat polymer and PNCI4, respectively) and a decrease in the rate of degradation (by 3.5% in PNCI2, 10.2% in PNCI4, and 49.3% in PNCI6). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Microwave heating of poly(ethylene terephthalate) bottle preforms used in the thermoforming process
Authors: Lebaudy Philippe , Estel Lionel , Ledoux Alain
Published: February 2008

Thermoforming (free blowing) of poly(ethylene terephthalate) preforms was successfully and quickly performed in a rotating system designed for dielectric hysteresis heating. Temperature profile modeling was carried out with the amorphous poly(ethylene terephthalate) permittivity at different temperatures. The Maxwell and heat equations were used to determine the best profile and power tuning. The determination of the theoretical boundary conditions was accomplished by the adjustment of the numerical transient external surface wall temperature with experimental infrared pyrometry results. In comparison with infrared, microwaves allowed high power density absorption inside the perform wall without a dramatic temperature gradient. Consequently, the heat blowing stage could be accelerated, and the process took at least 5 times less energy than infrared heating. Industrial applications involve the integration of the molding step and the design of the overall process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Chelation properties of poly(β‐diketone) polymer and its oxime toward heavy metal ions
Authors: Hammad Eman M. , Mubarak Mohammad S.
Published: February 2008

The chelation behavior of poly(β‐diketone), polymer I, and poly(β‐diketone) oxime, polymer II, toward the divalent metal ions, Cu2+, Zn2+, Ni2+, and Cd2+, and the trivalent lanthanide metal ions, La3+, Nd3+, Sm3+, Gd3+, and Tb3+ was investigated by a batch equilibration technique as a function of contact time, pH, and counter ion. Polymer II exhibited improved chelation characteristics toward lanthanide metal ions in comparison with polymer I and the metal‐ion uptake follows the order Tb3+ ≈ Gd3+ ≈ Sm3+ > Nd3+ ≈ La3+. On the other hand, polymer I showed relatively higher capacity than polymer II, toward the investigated divalent metal ions, where the metal‐ion uptake follows the order Cu2+ > Cd2+ ≈ Zn2+ > Ni2+. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Graft copolymerization of sodium acrylate onto organophilic montmorillonites initiated by potassium diperiodatonickelate (IV) and application of graft copolymer in water‐superabsorbent
Authors: Deng Kui Lin , Zheng Xiang Yang , Liu Jing , Zhang Ya Qin , Jia Na , Tian Hua , Liu Ying Hai
Published: February 2008

The graft copolymerization of sodium acrylate (SA) onto organophilic montmorillonites (OMMT) initiated by redox reaction of potassium diperiodatonickelate (IV) [Ni(IV)] with reactive groups on OMMT substrate was studied in alkaline medium. The grafting parameters have been investigated as a function of the ratio of monomer to OMMT, the concentration of initiator, temperature, and pH value. The structure of the graft copolymer (OMMT‐g‐PSA) was systematically characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscope (SEM). It was found that [Ni(IV)] belongs to a highly efficient initiator for graft copolymerization of SA onto OMMT via the redox iniation (grafting efficiency > 95%). Furthermore, the experimental results also showed that the graft copolymer gels synthesized under optimal condition exhibited a maximum water absorbency of 1104 g/g in distilled water and 111 g/g in 0.2 wt % NaCl solution, respectively, and its water retention ability is more than 91% after centrifugal separation for 2 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Viscoelasticity of epoxy resin/silica hybrid materials with an acid anhydride curing agent
Authors: Araki Wakako , Wada Shogo , Adachi Tadaharu
Published: February 2008

The viscoelasticity of epoxy resin/silica hybrid materials manufactured by the sol–gel process with an acid anhydride curing agent was investigated in terms of morphology. Transmission microscopy observations demonstrated that all the prepared hybrid samples had a two‐phased structure consisting of an epoxy phase and a silica phase. The formed silica had either nanosized particles or coarse domains, depending on the catalyst for the sol–gel process. Raman spectroscopy analysis showed that the formed silica had features typical of sol–gel derived silica glass and that the ring‐opening reactions of the epoxy groups developed in the hybrid samples and in the neat epoxy samples. In dynamic mechanical thermal analysis, there were two transition temperatures due to epoxy chain mobility and epoxy network relaxation, through which the moduli changed by nearly 3 orders of magnitude. The hybridization disturbed epoxy network formation but also reinforced the epoxy network with the formed silica, which was characterized by the activation energy of the network relaxation; therefore, the modulus of the rubbery state was correlated to the activation energy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Knee Posture Predicted from Subchondral Apparent Density in the Distal Femur: An Experimental Validation
Authors: Polk John D. , Blumenfeld J. , Ahluwalia D.
Published: February 2008

Spatial patterning in the apparent density of subchondral bone can be used to discriminate between species that differ in their joint loading conditions. This study provides an experimental test of two hypotheses that relate aspects of subchondral apparent density patterns to joint loading conditions. First, the region of maximum subchondral apparent density (RMD) will correspond to differences in joint posture at the time of peak locomotor loads; and second, differences in maximum density between individuals will correspond to differences in exercise level. These hypotheses were tested using three age‐matched samples of juvenile sheep. Two groups of five sheep were exercised, at moderate walking speeds, twice daily for 45 days on a treadmill with either a 0% or 15% grade. The remaining sheep were not exercised. Sheep walking on the inclined treadmill used more flexed knee postures than those in the level walking group at the time of peak vertical ground reaction forces. Kinematic measurements of knee posture were compared with knee postures estimated from the spatial position of the RMD on the medial femoral condyle. Our results show that the difference in the position of the RMD between the incline and level walking groups corresponded to the difference in knee postures obtained kinematically; however, exercised and nonexercised sheep did not differ in the magnitude of apparent density. These results suggest that patterns of subchondral apparent density are good indicators of the experimental modifications in joint posture during locomotion and may, therefore, be used to investigate differences between species in habitual joint loading. Anat Rec, 291:293–302, 2008. © 2008 Wiley‐Liss, Inc.