bluuebunny/crossref_metadata_2025 huggingface dataset:
Biosniffers (Gas‐Phase Biosensors) as Artificial Olfaction
Authors: Mitsubayashi Kohji
Published: February 2008

Biochemical gas sensors (called
biosniffers
have been developed as one of the gas‐phase bioassay approaches by using biological recognition systems such as drug metabolizing enzymes. Various kinds of volatile chemicals are analyzed by the biosniffers, with excellent gas selectivity being attributable to biological interactions such as enzyme specificity. The biochemical sniffers have been used for environmental assessment and human odor analysis as physiological and dental diagnoses. Potential application of the biosniffers includes not only its use, instead of sniffer dogs, in the detection of illegal drugs, nerve gases, and disaster victims but also artificial olfaction for smell informatics (smell communication, biometrics, etc.).
Fiber‐Optic Array Biosensors
Authors: Gašparac Rahela , Walt David R.
Published: February 2008

The pursuit of next generation biosensors that provide a high level of multiplexing at a reasonable cost is a high priority in the biosensing community. Biosensors based on optical fibers can detect numerous species accurately and inexpensively. Both single optical fibers and optical fiber arrays have been used for biosensing based on biological recognition events. This chapter reviews progress and developments in the past decade on fiber‐optic array platforms used for nucleic acid, enzyme, whole‐cell, and immunoassay (antibody/antigen) biosensing.
Surface Plasmon Resonance Array Devices
Authors: Suzuki Masayasu , Iribe Yasunori , Tobita Tatsuya
Published: February 2008

In this chapter, we describe a high‐resolution surface plasmon resonance (SPR) imaging system combined with a novel microwell array chip. Our developed microwell array chip consists of highly integrated microwells on a metal (Au, Ag, or Al) film–coated glass substrate (SF6). Well size was designed to the size of a single B cell. When silver film and short‐wavelength light were used, the largest brightness gradient was obtained. Mouse immunoglobulin G (IgG) was detected in the microarray. This result shows the possibility of real‐time monitoring for antibody production by B lymphocytes in microwell arrays.
An Electrochemical Biochip Sensor for the Detection of Pollutants
Authors: Popovtzer Rachela , Shacham‐Diamand Yosi , Rishpon Judith
Published: February 2008

In this chapter we will introduce the general concept of cell‐based biochip sensors. We will focus on the development of cell‐based biochip sensor for the detection of acute toxicity in water, which was performed at Tel Aviv University.
Field‐Operable Biosensors for Tropical Dispatch
Authors: Ionescu Rodica E. , Yavelsky Victoria , Amir Tamar , Gavrielov Natalie , Lobel Leslie
Published: February 2008

Globalization is a primary factor aiding spread of emerging infectious diseases. Thus, detection of pathogens is more critical than in the past, as recent outbreaks of SARS along with emergence of antibiotic‐resistant microorganisms have demonstrated. Owing to the increasing need for detection of infectious agents in the field, and in third world countries, field operability of detection systems is becoming key for surveillance in endemic regions of the world. As such this chapter presents currently available technologies that can be employed in such portable detection systems to help meet the emerging disease challenges of the coming years.
Lateral‐Flow Immunochromatographic Assays
Authors: Davies R. J. , Eapen S. S. , Carlisle S. J.
Published: February 2008

This overview of lateral‐flow immunochromatographic assays covers the development of the first of such tests for pregnancy, their general mode of operation and the role of, and interplay between, their different components. Emerging materials and issues related to the wider range of biofluids these devices are now designed to work with are also discussed. This assay platform has existed for almost 20 years and despite efforts to improve upon it, its ability to produce an accurate and rapid result in the hands of both professional and naïve user 8 will ensure that its spectrum of applicability widens.
Genetic and OtherDNA‐Based Biosensor Applications
Authors: Laureyn Wim , Stakenborg Tim , Jacobs Paul
Published: February 2008

The interest and research effort into the development of DNA diagnostic tools has increased dramatically and new instruments to detect, analyze, and quantify gene‐specific information are expected to revolutionize healthcare. In this chapter, a number of application fields for DNA‐based biosensors are described, together with some examples highlighting the specific nature of DNA‐based diagnostics, its impact on biosensor requirements, and how specific challenges in the field can be addressed. An overview, illustrated with some original work, provides aspects of a potential route toward affordable DNA‐sensor arrays with a particular focus on multiplexing and compatibility with polymer integration technology.
Utility of Biosensors in the Pharmaceutical Industry
Authors: Chapman Trevor , Legge Coulton , Patel Ash
Published: February 2008

The pharmaceutical industry continues to undergo major change while our knowledge of the mechanisms of disease continues to grow, which is, in part, attributable to the advances made within the biosensor community. This contribution will present an overview of areas within the pharmaceutical R&D process that are currently making progress through the use of biosensors. The merits of these techniques will be given along with suggestions on where they could be further improved. Finally, future requirements of biosensors and why their developments may become key to the continued success of the field within the pharmaceutical industry will be presented.
Chip‐Based Biosensors for Environmental Monitoring
Authors: Rogers Kim R.
Published: February 2008

Technological advances in microfabrication and detection techniques continue to effectively miniaturize biosensors onto planer surfaces. One of the advantages of this evolution is the ability to simultaneously measure multiple analytes or multiple attributes of a single sample using an array of biorecognition elements. Multi‐analyte capability often requires more versatile, complex, and expensive instrumentation adapted to multiple biorecognition elements (e.g., multiple antibodies). Although biosensor technologies, for the most part, have shown limited application and commercialization as stand‐alone analytical devices, biosensor concepts and technologies, particularly for biochip formats, have provided key components in a wide range of clinical, diagnostic, and research instrumentation.

Although chip‐based biosensors show the potential for meeting some of the persistent environmental monitoring needs such as simple, cost‐effective, and portable multi‐analyte analysis methods, a range of challenges must be overcome before biosensors find widespread use in environmental monitoring applications. One of the keys to the successful development of chip‐based biosensor systems for environmental applications will be to make use of their multi‐analyte array capability. Nevertheless, it is critical to consider issues such as multiple and shifting pollutants of concern as well as sample preparation strategies for difficult and variable matrices.
Environmental Biochemical Oxygen Demand and Related Measurement
Authors: Nomura Yoko , Shimomura‐Shimizu Mifumi , Karube Isao
Published: February 2008

Biosensors are often used for environmental analyses such as biochemical oxygen demand (BOD) measurements since they can measure or detect pollutants without the special techniques required by conventional methods. Many types of biosensors such as microbial sensors, enzyme sensors, and immunosensors have been developed, and microbial sensors (whole‐cell sensors) are very suitable for environmental monitoring because of their stability. This section describes the BOD sensor as the first microbial sensor or whole‐cell sensor; a few other related microbial sensors are also discussed.
Food and Beverage Applications of Biosensor Technologies
Authors: Schnerr Helge R.
Published: February 2008

The quality control of nutritional content and confirmation of food safety are major tasks for food manufacturers to ensure high‐quality standards and minimize the risk for the consumer. Since food products and their raw materials are complex mixtures of chemical compounds, highly specific, cost‐effective, and reliable methods are increasingly needed. For the past 25 years, we have witnessed remarkable progress in the development of affinity biosensors and their applications in areas such as medical diagnostics, drug screening, and food safety and security.

This chapter presents a review of the potential application of biosensors in the food and drinks industry, the commercially available systems, and some upcoming technology for future developments in this sector.
Agriculture, Horticulture, and Related Applications
Authors: Terry Leon A.
Published: February 2008

The inherent specificity, selectivity, and adaptability of biosensors make them ideal candidates for use throughout the food industry. Until now the main impact of these devices has been in the medical diagnostics field. However, with ongoing technical development, the food industry will be one of the prime beneficiaries from biosensor technology in the future. This chapter assesses the current and future trends in the application of biosensors to the food industry, particularly focusing on both potential and current target analytes that are fundamental to fresh produce quality, traceability, and safety.
FromEarth to Space: Biosensing at the International Space Station
Authors: Baumstark‐Khan Christa , Hellweg Christine E.
Published: February 2008

Humans in space, on board of the International Space Station (ISS) as well as in interplanetary missions, are confronted to a complex matrix of a multitude of environmental factors of various kinds and intensities, with microgravity and cosmic radiation as the most dominant stressors. In the endeavor to assess the risks for humans in space—especially for long‐duration missions—the concerted action of all stimuli has to be known and warning signals about changes of the “health” status of the environment are required. The ISS can be used by scientists and industry as a test bed for the development and validation of biomonitoring systems for human space flight activities and earth‐bound applications. The ISS is still under construction, with many challenges yet to come. Despite somewhat constrained resources available for research to date, much has already been accomplished. Unique investigations in human life sciences have been completed, are still in progress or in preparation, utilizing available facilities on board, such as the Human Research Facility (HRF). Additional facilities, such as the European Laboratory Columbus equipped with different science racks will be added in the coming years, and new types of investigations will be enabled.
Surface‐Enhanced Laser Desorption/Ionization (
SELDI
) Technology
Authors: Lomas Lee O. , Weinberger Scot R.
Published: February 2008

Surface enhanced laser desorption/ionization (SELDI) protein array technology represents a collection of analytical tools and protocols that address the challenges of protein separation, protein purification, and protein detection by mass spectrometry (MS). Commercially, SELDI has been embodied within Ciphergen Biosystems Inc. ProteinChip®Array products (Fremont, CA, USA). First introduced as a commercial product in 1997, this collection of tools has played a significant role, although at times controversial, in the shaping of the proteomics field and in particular the role of “biomarkers” and their relevance to translational medicine. Most recently, SELDI technology has demonstrated the ability to translate the fundamental discovery of protein biomarkers into predictive assays for the purpose of diagnosing the presence of metabolic disease and cancer. This chapter serves as an introduction to the fundamentals of SELDI biochip array technology and providing a recent review of new technologies and achievements in basic proteomic and clinical proteomic research.
Commercialization of
DNA
Arrays—Affymetrix a Case Study
Authors: Abramowitz Stanley
Published: February 2008

The relevance and uses of DNA arrays primarily in biomedical and health applications is discussed as well their commercialization. Particular emphasis is placed on Affymetrix as a model for the commercialization of DNA arrays.
RAPTOR
: Development of a Fiber‐Optic Biosensor
Authors: Anderson George P. , McCrae David A.
Published: February 2008

This chapter reviews the development of the fiber‐optic biosensor at the Naval Research Laboratory and the path that led toward the instrument currently produced by Research International, the RAPTOR. We also look ahead to the future of this technology and the capabilities of its successor the BioHawk.
Conducting Polymer Nanowire‐Based Biosensors
Authors: Wanekaya Adam K. , Chen Wilfred , Myung Nosang V. , Mulchandani Ashok
Published: February 2008

This chapter addresses the applications of conducting polymer nanowires (CP NWs) in chemical and biological sensing. In the first section, we introduce CP NWs as new members of the one‐dimensional (1D) nanostructured materials family. We discuss the advantages associated with the use of 1D nanostructure materials in general and CP NWs in particular. In the second section, various methods that are used to synthesize and fabricate CP NWs are discussed including their strengths and limitations. The third section outlines the functionalization of these nanostructures to tailor them to respond only to desired target analytes while the fourth section involves the assembly/alignment of these CP NWs to form functional devices. We demonstrate some sensing applications based on CP NWs in the fifth section and conclude with a brief summary and outlook on the future of CP NWs in sensing applications and some of the limitations that have to be overcome to make them competitive sensing materials.
Manipulation and Detection of Magnetic Nanoparticles for Diagnostic Applications
Authors: Yellen Benjamin B. , Erb Randall M.
Published: February 2008

This review presents recent developments concerning the use of nanoscale magnetic materials in the field of biosensors and bioelectronics. Compared with optical and electrical materials, magnetic materials enjoy several advantages which have been applied to numerous bioanalytical devices. For example, biological fluids do not attenuate magnetic fields, which is advantageous both for detection and manipulation systems due to the reduction of background noise. Magnetic materials are also more stable than their fluorescent counterparts, in which photo‐bleaching is a serious impediment to quantitative analysis. This article begins with a brief tutorial on the magnetization behavior of nanoscale magnetic materials. It is followed by a discussion of how force can be applied to colloidal materials with various magnetic manipulation apparatus, with a particular emphasis on the role that size and geometry play in determining the efficiency of magnetic particle manipulation in the context of randomizing thermal energy. Design principles will be provided to demonstrate how the manipulation apparatus can achieve greater flexibility by using two sources of magnetic field, one which produces strong local magnetic field gradient and the other which produces uniform magnetic field. Next, we review recent developments on miniature magnetic field sensor devices, which are routinely applied to detect and analyze the presence of biological molecules and micro‐organisms. An outline of the different types of magnetic field sensors used in biodiagnostics is provided, however the focus is mainly on the physical principles underlying the most commonly used sensor based on magnetoresistive materials. Finally, a brief conclusion is provided on the future outlook of nanoscale magnetic materials in lab‐on‐a‐chip devices.
Biosensors for Neurological Disease
Authors: Bell Kathryn M. , Kornguth Steven E.
Published: February 2008

The diagnosis of neurological disease (ND) traditionally involves the association of specific symptoms in a patient with a clinical examination, consideration of the patient's prior medical history, and clinical laboratory testing (e.g., electroencephalography, electromyography). The decoding of the human genome has made possible the identification of proteomic and genomic biomarkers associated with specific neurological disorders. The identification of multiple biomarkers, including determination of chemical nature and concentration, provides a disease “signature” that is not achievable through testing for any single marker alone. Biomarker signatures can augment conventional clinical evaluation and testing by improving diagnosis, prognosis, monitoring progression, and management of ND. Biomarker signature profiling for a patient can allow for personalized medicine catered to individual need.

The need for biosensors in the detection of ND is illustrated by recent events. Two cases of bovine spongiform encephalopathy (BSE) in Canada have cost their beef industry millions of dollars and resulted in precluding shipment of cattle from Canada to the United States. The ability to determine absence of prion disease in live cattle could greatly increase confidence in cattle imports. In a separate example, Tysabri, an immunosuppressant drug effective in lengthening periods of remission in patients with multiple sclerosis (MS), was withdrawn from the market because of occurrence of progressive multifocal leukoencephalopathy (PML) in treated individuals. PML in the treated MS individuals was caused by proliferation of JC virus. The ability to detect JC virus production during treatment with Tysabri could remedy this problem.

Biosensors designed to detect analytes indicative of disease are currently available. Ranging from single target detection to more complex multitarget signature profiling, these biosensors are offered for a wide range of disorders. Many focus on the detection of cancer and ND. The platforms used for cancer detection are directly applicable to ND determination because the sensors detect analytes or genetic mutations present in both disease types. Specific products and technologies that are already being used for or can be readily adapted to ND diagnosis, prognosis, and treatment are discussed. A select list of ND‐related biomarkers for current and future study is presented.
Need for Biosensors in Infectious Disease Epidemiology
Authors: Baril Laurence
Published: February 2008

Infectious disease epidemiology is an emerging discipline which requires a strong interdisciplinary approach. Most infectious diseases do not occur randomly but are related to environmental, economic, societal, and personal characteristics. Novel laboratory testing tools such as optical biosensors will improve the quality of the epidemiological information. In this chapter, the author discusses infectious disease epidemiology, and the methods used in the different applications of this domain. A practical lexicon of the main definitions used in epidemiology and in testing the performance of newly developed diagnostic tools is proposed.
Aptameric Biosensors
Authors: Meir Anat , Marks Robert S. , Stojanovic Milan N.
Published: February 2008

Aptamers are synthetic single stranded DNA or RNA molecules that can bind with high affinity and specificity to their non‐nucleic acid target molecules. The artificial nucleic acid ligands can be generated against proteins, small molecules, ions, whole cells, tissues and organs.

The process of aptamers isolation, their affinity properties and applications thereof are described. In addition, the particular case of how structural changes in aptamers can be used to construct fluorescent molecular sensors coupling both recognition and signaling properties is explained and their use finally as recognition elements in various platforms of biosensors are herein illustrated.
Biosensors Based on Single‐Walled Carbon Nanotube Near‐Infrared Fluorescence
Authors: Barone Paul W. , Jeng Esther S. , Heller Daniel A. , Strano Michael S.
Published: February 2008

Single walled carbon nanotubes (SWNT) possess unique optical properties that render them excellent materials for biosensing. SWNTs photoluminesce at near‐infrared wavelengths, where scattering and absorption from tissue, whole blood, and water is low; and cell autofluorescence is minimal. Furthermore all of the SWNT atoms are on the surface, making them sensitive to local events. This chapter discusses the use of SWNT photoluminescence for bionsensors. One class of sensors utilizes the modulation of photoluminescence intensity to detect molecules such as glucose. A decrease in the intensity is caused by the reaction of glucose oxidase with glucose, coupled to another mediating reaction. Another type of sensor detects events through a shift in the photoluminescence energy. In one scheme DNA hybridizes on the nanotube, resulting in an increased surface coverage of the nanotube after hybridization, causing a photoluminescence energy increase. In another system, divalent ions induce a structural change in DNA strands that are wrapped around SWNTs causing an energy decrease in the nanotube photoluminescence. This sensor is capable of detecting ions even in highly scattering media such as blood, and inside cells. SWNTs represent a new class of materials that have the potential to be widely utilized in various biosensing applications.
Nucleic Acid Arrays
Authors: Miyachi Hirotaka
Published: February 2008

After the completion of the genome project, researchers confronted the issue of requirement of multiple‐detection tools for gene analysis in a single experiment. Today, nucleic acid arrays are the fashion in the field of biological research, genomics, and medical science. In this chapter, the technical foundations of nucleic acid array technology as well as recent research and developments are discussed. The integration of semiconductor and nanotechnology in array production technologies are also discussed.
Prevalence of parameter indicators of obesity and its relationship with metabolic syndrome in urban Moroccan women
Authors: Ayachi Mohammed El , Mohamed Mziwira , Denis Lairon , Rekia Belahsen
Published: February 2008

This study aimed to examine the relationship between metabolic syndrome (MS) and different types of obesity in urban Moroccan women. On 213 women aged 25–55 years, Triglycerides (TG), total cholesterol, high‐density lipoprotein cholesterol (HDL‐c), lower‐density lipoprotein cholesterol (LDL‐c), and fasting blood glucose levels were assessed. Body mass index (BMI), waist to hip ratio (WHR), Waist circumference (WC), and blood pressure (BP) were also measured. Globally 36.6% of women were overweight (25 ≤ BMI < 30 m2), 23.9% obese (BMI > 30 m2), 19.7% had WHR > 0.85 and 28.8% had WC ≥ 88 cm. Indicators of obesity increased with age and the prevalence of co‐morbid factors increased with obesity. The women with android obesity (WHR > 0.85) and central obesity (WC ≥ 88 cm) had greater risk compared to those with overweight and general obesity. The prevalence of MS was 17.8% and increased (31.49%) with high BMI and high WHR (50%). MS and its co‐morbidity factors are prevalent among Moroccan women aged 35years and over. The exaggerated influence of obesity in this prevalence suggests that the prevention of obesity could prevent MS and its complications. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Ontogenesis changes and sex dimorphism of subcutaneous fat distribution: 12‐Year longitudinal study of children and adolescents from Cracow, Poland
Authors: Chrzanowska Maria , Suder Agnieszka
Published: February 2008

The aim of the work was to analyze the direction and tempo of subcutaneous fat redistribution during ontogenesis, appearing sex differences and relations to puberty on the basis of 12‐year longitudinal data of 270 boys and 154 girls from Cracow, Poland. They all had complete data (from 7 to 18‐years old) of three trunk (subscapular, abdominal, suprailiac) and three extremity (triceps, knee, medial calf) skinfold thicknesses. The type of subcutaneous adipose tissue distribution was determined based on trunk to extremity ratio to analyze the process of fat redistribution. The analysis included medians of extremity and trunk skinfolds and medians of their sums and age altered frequency of central and peripheral type of fat distribution. To present empirical values, the median variability of the sums of three trunk and extremity skinfolds was calculated using a third degree polynomial as an age function. Polynomial regression of extremity skinfolds median explained 88% of its variability (F = 71.2, P < 0.001) and for trunk skinfolds as far as 96% (F = 111.65, P < 0.001). The median variability curves of both types of distribution crossed at the age of 11.88 in girls and 13.45 in boys directly preceding puberty stage, which indicated clear dependencies between fat redistribution and puberty. The results showed a tight connection between the process of subcutaneous fat redistribution and puberty, and also sex dimorphism of the process. More dynamic fat redistribution in boys contrasted trunk and extremity fatness, while in girls less dynamic changes resulted in more even fatness. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Transport properties of natural rubber latex layered clay nanocomposites
Authors: Jacob Ansu , Kurian Philip , Aprem Abi Santhosh
Published: February 2008

Natural rubber latex layered clay nanocomposites were prepared with low loadings of nanoclay using conventional compounding technique. A higher loading of clay resulted in processing difficulties due to viscosity build up. X‐ray analysis showed that nanocomposites in which layered silicate layers were either delaminated or ordered as in an intercalated structure was obtained. Partially exfoliated structure was observed from TEM photographs of nanocomposites with 3 phr nanoclay. The transport properties, sorption, diffusion, and permeation coefficients were measured using the solvent toluene at 303 K. A higher decrease for the diffusion coefficient for nanocomposites directs the presence of tortuous path for the diffusing molecules. Thermodynamic parameters show a better compatibility for the silicates with rubber resulted in the formation of an elastomeric network. Gas permeability results of the nanocomposites suggest a better barrier resistancefor oxygen molecules even in lower loading of nanoclay and different gas transport models (Nielsen, Bharadwaj, Cussler) were applied to describe the behavior of these nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Chemoselective hydrolysis of methyl 2‐acetoxybenzoate using free and entrapped esterase in K‐carrageenan beads
Authors: Desai P. D. , Dave A. M. , Devi Surekha
Published: February 2008

Porcine liver esterase was entrapped in natural polysaccharides K‐carrageenan and retention of its activity was determined using p‐nitrophenyl acetate as the substrate. The optimum pH for esterase activity of entrapped enzyme showed a little shift towards acidic side. Immobilized enzyme showed improved thermal and storage stability. The entrapped esterase retained 50% of its activity after eight repetitive cycles. Michaelis constant Km for the free and entrapped enzymes was almost same indicting no conformational change during immobilization. Maximum velocity Vmax was observed to decrease on immobilization. The free and entrapped esterase was used for selective hydrolysis of methyl 2‐acetoxybenzoate to methyl 2‐hydroxybenzoate in batch process as well as in a fixed bed reactor. The hydrolysis was observed to be 99% within 2 h for free as well as immobilized enzyme in batch process. The rate of hydrolysis was found to depend on pH. The turn over number of selective hydrolysis in batch and fixed bed reactor was 3.08 × 106 and 1.19 × 107, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Accurate determination of calcium stearate by atomic absorption spectrophotometric method in polymer
Authors: Farajzadeh Mir Ali , Ravandi Mahboobe Ghorbani , Ranji Ali , Feyz Elham
Published: February 2008

In this study, an atomic absorption spectrophotometric method is presented for the determination of calcium stearate in polymer samples after their pyrolysis. Samples of polymers were burned in an electrical furnace at 500°C. After thermal degradation of polymeric matrix, 1M HCl solution was added to dissolve the residue. Then the absorbance of solution was measured by an atomic absorption spectrophotometer at calcium atomic line. This method has an extent linear dynamic range (0.4–50 mg/L) with a limit of detection (LOD) 0.1 mg/L in solution. LOD of the proposed method in polymer sample using 0.5 g sample size is 15 ppm as calcium stearate. Some effective parameters such as time and temperature of pyrolysis and concentration of hydrochloric acid were studied. Finally, this method was successfully applied for the determination of calcium stearate content of standard and real polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of N‐polyethereal polypyrroles and their application for the preconcentration of rare earth ions
Authors: Köksel Bahar , Cihaner Atilla , Kaya Murat , Volkan Mürvet , Önal Ahmet M.
Published: February 2008

Conducting polymers containing polyether pseudocages (PI, PII, PIII) have been synthesized via chemical oxidation of 1,5‐bis(1,1‐pyrrole)‐3‐oxabutane (MI), 1,8‐bis(1,1‐pyrrole)‐3,6‐dioxahexane (MII), and 1,11‐bis(1,1‐pyrrole)‐3,6,9‐trioxaundecane (MIII) using anhydrous FeCl3 in CHCl3. Because as obtained polymer resins did not give any response toward any cations, they were reduced (undoped) using chemical reducing agents. Tetrabutylammonium hydroxide was found to be more effective in undoping to obtain more reproducible and reusable polymer resins. The undoped polymer resins were tried in the extraction of rare earth metal ions from the aqueous medium. Among them, only PIII resin removes La(III), Eu(III) and Yb(III) and can be employed for the preconcentration of these metal ions. For batch extraction of La(III), Eu(III) and Yb(III) at neutral pH values, percent recoveries of 98.0 ± 1.0, 90.7 ± 1.4, 87.3 ± 4.0, respectively, has been obtained. The sorption capacity is found as 1.3 mg of La(III) per gram of PIII resin. The PIII resin could be reused at least five times without significant change in its sorption capacity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and self‐assembly of cationic coumarin side‐chain polymer
Authors: Zhang Chuanzhi , Liang Ruiyuan , Jiang Chunxia , Chen Deben , Zhong Anyong
Published: February 2008

In this study, the synthesis of a novel cationic coumarin‐containing polymer (C‐CPA) was presented. C‐CPA was examined optically using photoluminescence (PL) spectroscopy. The optical data suggested that they were promising blue‐emitting materials mainly due to the coumarin chromophore on the side chain. Moreover, the synthesized cationic polymer was suitable for layer‐by‐layer electrostatic self‐assembly thin film deposition from dilute polymer solution and multilayers were fully characterized by UV–vis spectroscopy, PL spectroscopy and atomic force microscope. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of crystalline microstructure near the particle/matrix interface on the toughening of syndiotactic polystyrene/polyamide‐6 blends
Authors: Il Kang Byung , Nair Sobha V. , Yang Hoichang , Lim Ho Sun , Lee Dae Ho , Cho Kilwon
Published: February 2008

Toughening behavior of semicrystalline polymers was investigated using syndiotactic polystyrene (sPS)/polyamide 6(PA‐6) blends compatibilized with maleic‐anhydride functionalized poly (styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) SEBS‐MA triblock copolymer. The effect of interparticle distance and crystal microstructure near the particle/matrix interface of the blends were studied. The morphology studies revealed that the size and interparticle distance of the dispersed PA‐6 particles decreased with increasing SEBS‐MA concentration. sPS/PA‐6 blends exhibited sharp brittle‐ductile transitions at a critical interparticle distance of 0.25 μm. With the increase of the compatibilizer concentration beyond a certain level, it was observed that the further addition resulted in decreased impact strength. This could be attributed to the formation of a separate phase in the matrix by the additional SEBS added. The TEM studies showed that when the interparticle distance is below 0.25 μm, the matrix ligaments between the inclusions will be filled with well‐oriented crystalline material of reduced plastic resistance. From DSC and X‐ray diffraction studies of model thin films, it was found that the fraction of small and imperfect crystallites near the particle/matrix interface increased with decreasing interparticle distance. This resulted in decreased yield stress of the whole matrix with increasing concentration of SEBS‐MA accompanied by changes in the fracture mode from brittle to tough. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Tuning the particle size and charge density of the crosslinked polystyrene particles
Authors: Arunbabu Dhamodaran , Sannigrahi Arindam , Jana Tushar
Published: February 2008

We report the synthesis of charged spherical colloidal particles of poly [styrene‐(co‐2‐propene sulfonic acid)] crosslinked with divinylbenzene by emulsion polymerization. The effects of concentration of both the emulsifier and initiator on the polymerization, particle size, and charge density are studied. The particle size is found to be dependent on both the emulsifier and initiator concentration and their power dependencies are different. Below critical micelle concentration (CMC), the particle size varies significantly within a small range of emulsifier concentration. In contrast, particle size decrease is not very pronounced at the heterogeneous (micellar) particle nucleation regime where the emulsifier concentration is well above of the CMC. The power dependencies of the number of particles on surfactant concentration are explained in the light of conversion–time profile of the polymerization. The surface charge density of the colloidal particles also varies with both the emulsifier and initiator concentration. Both the particle size and charge density show an inverse relation with the molecular weight of the polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Degradation behavior of linear low‐density polyethylene films containing prooxidants under accelerated test conditions
Authors: Roy P. K. , Surekha P. , Rajagopal C. , Choudhary V.
Published: February 2008

This article reports the results of studies on the photooxidative and thermooxidative degradation of linear low‐density polyethylene (LLDPE) in the presence of cobalt stearate. Various amounts of cobalt stearate (0.1–0.9% w/w) blended with LLDPE and films of 70 ± 5 μ thickness were prepared by a film‐blowing technique. The films were subjected to xenon arc weathering and air‐oven aging tests (at 70°C) for extended time periods. We followed the chemical and physical changes induced as a result of aging by monitoring changes in the mechanical properties (tensile strength and elongation at break), carbonyl index, morphology (scanning electron microscopy), melt flow index, and differential scanning calorimetry crystallinity. Cobalt stearate was highly effective in accelerating the photodegradation of LLDPE films at concentrations greater than 0.2% w/w. The kinetic parameters of degradation, as determined by nonisothermal thermogravimetric analysis, were estimated with the Flynn–Wall–Ozawa isoconversion technique, which was subsequently used to determine the effect of cobalt stearate on the theoretical lifetime of LLDPE. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Melatonin is as Effective as Testosterone in the Prevention of Soleus Muscle Atrophy Induced by Castration in Rats
Authors: Öner Jale , Öner Hakan , Sahin Zeliha , Demir Ramazan , Üstünel İsmail
Published: February 2008

The purpose of this experiment was to compare the weight, insulin‐like growth factor‐I (IGF‐I) expression, and ultrastructure of the soleus muscle in growing castrated rats treated with testosterone or melatonin. In this study, adult male Wistar albino rats were used. The groups were arranged as sham, castrated, and testosterone‐ or melatonin‐injected groups after castration. The soleus muscle samples were fixed in Bouin's solution for immunohistochemistry, and in 2.5% gluteraldehyde in 0.1 M phosphate buffer (pH 7.4). Whereas castration reduced the soleus weight and fiber diameter, testosterone and melatonin administration increased them. IGF‐I immunostaining observed in the satellite cells and periphery of the myofibers was least intense in the castrated group. Strong staining of IGF‐I was observed in the testosterone‐ and melatonin‐administered groups. The ultrastructure of the soleus muscle in castrated animals showed the important ultrastructural modifications related to degeneration. In these groups, degenerative mitochondria, glycogen clusters under the sarcolemma, irregular Z lines, and loss of lamina externa were observed. The ultrastructure of myofibrils in the testosterone‐ and melatonin‐injected groups was similar to that in sham groups in view of structure. In conclusion, we suggest that melatonin is as effective as testosterone in the prevention of atrophy induced by castration through the IGF‐I axis. Anat Rec, 291:448–455, 2008. © 2008 Wiley‐Liss, Inc.
Information quality work organization in wikipedia
Authors: Stvilia Besiki , Twidale Michael B. , Smith Linda C. , Gasser Les
Published: February 2008

The classic problem within the information quality (IQ) research and practice community has been the problem of defining IQ. It has been found repeatedly that IQ is context sensitive and cannot be described, measured, and assured with a single model. There is a need for empirical case studies of IQ work in different systems to develop a systematic knowledge that can then inform and guide the construction of context‐specific IQ models. This article analyzes the organization of IQ assurance work in a large‐scale, open, collaborative encyclopedia—Wikipedia. What is special about Wikipedia as a resource is that the quality discussions and processes are strongly connected to the data itself and are accessible to the general public. This openness makes it particularly easy for researchers to study a particular kind of collaborative work that is highly distributed and that has a particularly substantial focus, not just on error detection but also on error correction. We believe that the study of those evolving debates and processes and of the IQ assurance model as a whole has useful implications for the improvement of quality in other more conventional databases.
Construction of Chemical‐Responsive Supramolecular Hydrogels from Guest‐Modified Cyclodextrins
Authors: Deng Wei , Yamaguchi Hiroyasu , Takashima Yoshinori , Harada Akira
Published: February 2008

A methodology for preparing supramolecular hydrogels from guest‐modified cyclodextrins (CDs) based on the host–guest and hydrogen‐bonding interactions of CDs is presented. Four types of modified CDs were synthesized to understand better the gelation mechanism. The 2D ROESY NMR spectrum of β‐CD‐AmTNB (Am=amino, TNB=trinitrobenzene) reveals that the TNB group was included in the β‐CD cavity. Pulsed field gradient NMR (PFG NMR) spectroscopy and AFM show that β‐CD‐AmTNB formed a supramolecular polymer in aqueous solution through head‐to‐tail stacking. Although β‐CD‐AmTNB did not produce a hydrogel due to insufficient growth of supramolecular polymers, β‐CD‐CiAmTNB (Ci=cinnamoyl) formed supramolecular fibrils through host–guest interactions. Hydrogen bonds between the cross‐linked fibrils resulted in the hydrogel, which displayed excellent chemical‐responsive properties. Gel‐to‐sol transitions occurred by adding 1‐adamantane carboxylic acid (AdCA) or urea. 1H NMR and induced circular dichroism (ICD) spectra reveal that AdCA released the guest parts from the CD cavity and that urea acts as a denaturing agent to break the hydrogen bonds between CDs. The hydrogel was also destroyed by adding β‐CD, which acts as the competitive host to reduce the fibrils. Furthermore, the gel changed to a sol by adding methyl orange (MO) as a guest compound, but the gel reappeared upon addition of α‐CD, which is a stronger host for MO.
Major congenital malformations following prenatal exposure to serotonin reuptake inhibitors and benzodiazepines using population‐based health data
Authors: Oberlander Tim F. , Warburton William , Misri Shaila , Riggs Wayne , Aghajanian Jaafar , Hertzman Clyde
Published: February 2008

BACKGROUND: To determine a population‐based incidence of congenital anomalies following prenatal exposure to serotonin reuptake inhibitor (SRI) antidepressants used alone and in combination with a benzodiazepines (BZ). METHODS: Population health data, maternal health, and prenatal prescription records were linked to neonatal records, representing all live births (British Columbia, Canada, N=119,547) during a 39‐month period (1998–2001). The incidence and risk differences (RD) for major congenital anomalies (CA) and congenital heart disease (CHD), including ventricular and atrial septal defects (VSD, ASD), from infants of mothers treated with an SRI alone, a benzodiazepine (BZ) alone, or SRI+BZ in combinationcompared to outcomesno exposure. RESULTS: Risk for a CA or CHD did increase following combined SRI+BZ exposure compared with no exposure. However, using a weighted regression model, controlling for maternal illness characteristics, combination therapy risk remained significantly associated only with CHD. The risk for an ASD was higher following SRI monotherapy compared with no exposure, after adjustment for maternal covariates. Dose/day was not associated with increased risk. CONCLUSIONS: Infants exposed to prenatal SRIs in combination with BZs had a higher a incidence of CHD compared to no exposure, even after controlling for maternal illness characteristics. SRI monotherapy was not associated with an increased risk for major CA, but was associated with an increased incidence of ASD. Risk was not associated with first trimester medication dose/day. Birth Defects Research (Part B) 83:68–76, 2008. © 2008 Wiley‐Liss, Inc.
Towards an integrated understanding of the structure and mechanics of the cell nucleus
Authors: Rowat Amy C. , Lammerding Jan , Herrmann Harald , Aebi Ueli
Published: February 2008

Changes in the shape and structural organization of the cell nucleus occur during many fundamental processes including development, differentiation and aging. In many of these processes, the cell responds to physical forces by altering gene expression within the nucleus. How the nucleus itself senses and responds to such mechanical cues is not well understood. In addition to these external forces, epigenetic modifications of chromatin structure inside the nucleus could also alter its physical properties. To achieve a better understanding, we need to elucidate the relationship between nuclear structure and material properties. Recently, new approaches have been developed to systematically investigate nuclear mechanical properties. These experiments provide important new insights into the disease mechanism of a growing class of tissue‐specific disorders termed ‘nuclear envelopathies’. Here we review our current understanding of what determines the shape and mechanical properties of the cell nucleus. BioEssays 30:226–236, 2008. © 2008 Wiley Periodicals, Inc.
Insight into initiator–DNA interactions: a lesson from the archaeal ORC
Authors: Tada Shusuke , Kundu Lena R. , Enomoto Takemi
Published: February 2008

Although initiation of DNA replication is considered to be highly coordinated through multiple protein–DNA and protein–protein interactions, it is poorly understood how particular locations within the eukaryotic chromosome are selected as origins of DNA replication. Here, we discuss recent reports that present structural information on the interaction characteristics of the archaeal orthologues of the eukaryotic origin recognition complex with their cognate binding sequences.1,2 Since the archaeal replication system is postulated as a simplified version of the one in eukaryotes, by analogy, these works provide insights into the functions of the eukaryotic initiator proteins. BioEssays 30:208–211, 2008. © 2008 Wiley Periodicals, Inc.
Gene expression studies on bio‐electrosprayed primary cardiac myocytes
Authors: Barry Seán P. , Jayasinghe Suwan N. , Pericleous Charis , Hubank Mike , Latchman David S. , Stephanou Anastasis
Published: February 2008

Cardiovascular pathology accounts for the greatest number of mortalities in the western world and thus the development of ex vivo cardiac tissue has vast potential in cardiac therapy. Bio‐electrosprays (BES), a recently discovered direct cell engineering protocol, has demonstrated tremendous applicability for regenerative and therapeutic medicine. For bio‐electrospraying to be carried forward as a novel method of cardiac tissue engineering, it is important that the process does not adversely affect cellular physiology. Our previous work has shown that bio‐electrospraying does not induce cell death, activate intracellular stress pathways or induce DNA damage in primary cardiac myocytes. Here we show for the first time using genome‐wide microarray analysis, that bio‐electrospraying has no negative effects on global gene expression in cardiac myocytes. Moreover, we show that bio‐electrospraying does not lead to endothelial cell activation. These data suggest that BES has minimal effect upon the physiology of cardiac myocytes and endothelial cells and thus paves the way for the development of BES in cardiac tissue engineering.
Challenges and opportunities for training the next generation of biophysicists: Perspectives of the directors of the Molecular Biophysics Training Program at Northwestern University
Authors: Neuhaus Francis , Widom Jonathan , MacDonald Robert , Jardetzky Theodore , Radhakrishnan Ishwar
Published: February 2008

Molecular biophysics is a broad, diverse, and dynamic field that has presented a variety of unique challenges and opportunities for training future generations of investigators. Having been or currently being intimately associated with the Molecular Biophysics Training Program at Northwestern, we present our perspectives on various issues that we have encountered over the years. We propose no cookie‐cutter solutions, as there is no consensus on what constitutes the “ideal” program. However, there is uniformity in opinion on some key issues that might be useful to those interested in establishing a biophysics training program. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 253–255, 2008.