bluuebunny/crossref_metadata_2025 huggingface dataset:
Why We Need a Pension Revolution
Authors: Ambachtsheer Keith
Published: February 2009

There is now a broad consensus that workplace pension arrangements around the world are sick and in need of strong medicine. Pension coverage and adequacy are too low, and pension uncertainty too high. The prescription of some pension experts is to resurrect the traditional defined-benefit (DB) plan. Others say broad defined-contribution (DC) plan coverage is the cure. This article argues that we have to move from an “either-or” to an “and-and” mindset if we want to seriously improve global workplace pension coverage, adequacy, and certainty. Integrative thinking about these issues leads to pension arrangements that combine the best of both traditional DB and DC plans, and that minimize the impact of their less attractive features. However, redesigning the pension formula is only half the cure. We must also redesign the institutional arrangements through which workplace pensions are delivered. The ideal pension delivery institution has expertise, scale, and acts solely in the best interests of plan participants. There are far too few pension funds around the world today that can meet this triple test. Placed in a Canadian context, the first priority should be to fill the workplace pension gap for the some 4 million Canadian private sector workers without registered pension plans currently facing materially reduced post-work standards of living.
Prediction Markets: The Practical and Normative Possibilities for the Social Production of Knowledge
Authors: Bragues George
Published: February 2009

The quest to foretell the future is omnipresent in human affairs. A potential solution to this epistemological conundrum has emerged through mass collaboration. Motored by the Internet, prediction markets allow a multitude of individuals to assume a stake in a security whose value is tied to a future event. The resulting prices offer a continuously updated probability estimate of the event actually taking place. This paper gives a survey of prediction markets, their history, mechanics, uses, and theoretical foundation. We also review the literature surrounding their efficacy. Though there are shortcomings with prediction markets, as well as practical constraints, they hold out the prospect of improving the quality of organizational decisions and increasing the level of participation in the deliberative process. We also note that lessons can be drawn from these markets to guide the epistemological practices of disciplines and inquiries in which empirical methods are difficult to apply.
Automatic Determination of Stepsize Parameters in Monte Carlo Simulation Tested on a Bromodomain-Binding Octapeptide
Authors: Banfelder Jason  R. , Speidel Joshua  A. , Mezei Mihaly
Published: February 2009

The proportional integral controller, commonly used in engineering applications for process control, has been implemented for the tuning of the stepsizes in Metropolis Monte Carlo simulations. Similarly to the recent application for tuning the chemical potential parameter in grand-canonical ensemble simulation, the process-control approach was found to work well for the problem of selecting the stepsize for each torsion angle that results in a targeted acceptance rate during the simulation of an octapeptide in aqueous environment.
Factors Affecting Polyphenol Biosynthesis in Wild and Field Grown St. John’s Wort (Hypericum perforatum L. Hypericaceae/Guttiferae)
Authors: Bruni Renato , Sacchetti Gianni
Published: February 2009

The increasing diffusion of herbal products is posing new questions: why are products so often different in their composition and efficacy? Which approach is more suitable to increase the biochemical productivity of medicinal plants with large-scale, low-cost solutions? Can the phytochemical profile of a medicinal plant be modulated in order to increase the accumulation of its most valuable constituents? Will polyphenol-rich medicinal crops ever be traded as commodities? Providing a proactive answer to such questions is an extremely hard task, due to the large number of variables involved: intraspecific chemodiversity, plant breeding, ontogenetic stage, post-harvest handling, biotic and abiotic factors, to name but a few. An ideal path in this direction should include the definition of optimum pre-harvesting and post-harvesting conditions and the availability of specific Good Agricultural Practices centered on secondary metabolism enhancement. The first steps to be taken are undoubtedly the evaluation and the organization of scattered data regarding the diverse factors involved in the optimization of medicinal plant cultivation, in order to provide an interdisciplinary overview of main possibilities, weaknesses and drawbacks. This review is intended to be a synopsis of the knowledge on this regard focused on Hypericum perforatum L. (Hypericaceae/Guttiferae) secondary metabolites of phenolic origin, with the aim to provide a reference and suggest an evolution towards the maximization of St. John's Wort bioactive constituents. Factors considered emerged not only from in-field agronomic results, but also from physiological, genetical, biotic, abiotic and phytochemical data that could be scaled up to the application level. To increase quality for final beneficiaries, growers’ profits and ultimately transform phenolic-rich medicinal crops into commodities, the emerging trend suggests an integrated and synergic approach. Agronomy and genetics will need to develop their breeding strategies taking account of the suggestions of phytochemistry, biochemistry, pharmacognosy and pharmacology, without losing sight of the economic balance of the production.
Manufacture of a Polyaniline Nanofiber Ammonia Sensor Integrated with a Readout Circuit Using the CMOS-MEMS Technique
Authors: Liu Mao-Chen , Dai Ching-Liang , Chan Chih-Hua , Wu Chyan-Chyi
Published: February 2009

This study presents the fabrication of a polyaniline nanofiber ammonia sensor integrated with a readout circuit on a chip using the commercial 0.35 mm complementary metal oxide semiconductor (CMOS) process and a post-process. The micro ammonia sensor consists of a sensing resistor and an ammonia sensing film. Polyaniline prepared by a chemical polymerization method was adopted as the ammonia sensing film. The fabrication of the ammonia sensor needs a post-process to etch the sacrificial layers and to expose the sensing resistor, and then the ammonia sensing film is coated on the sensing resistor. The ammonia sensor, which is of resistive type, changes its resistance when the sensing film adsorbs or desorbs ammonia gas. A readout circuit is employed to convert the resistance of the ammonia sensor into the voltage output. Experimental results show that the sensitivity of the ammonia sensor is about 0.88 mV/ppm at room temperature
Toxicity Evaluation for Safe Use of Nanomaterials: Recent Achievements and Technical Challenges
Authors: Hussain Saber M. , Braydich‐Stolle Laura K. , Schrand Amanda M. , Murdock Richard C. , Yu Kyung O. , Mattie David M. , Schlager John J. , Terrones Mauricio
Published: February 2009

Recent developments in the field of nanotechnology involving the synthesis of novel nanomaterials (NM) have attracted the attention of numerous scientists owing to the possibility of degradative perturbations in human health. This Review evaluates previous investigations related to NM toxicity studies using biological models and describes the limitations that often prevent toxicologists from identifying whether NM pose a real hazard to human health. One major limitation to assess toxicity is the characterization of the NM prior to and after exposure to living cells or animals. The most relevant physicochemical characteristics of NM are: size, surface chemistry, crystallinity, morphology, solubility, aggregation tendency, homogeneity of dispersions, and turbidity. All of these properties need to be assessed in order to determine their contribution to toxicity. Due to the lack of appropriate methods to determine the physicochemical nature of nanoparticles in biological systems, the exact nature of NM toxicity is not fully described or understood at this time. This Review emphasizes the need for state‐of‐the‐art physicochemical characterization, the determination of appropriate exposure protocols and reliable methods for assessing NM internalization and their kinetics in living organisms. Once these issues are addressed, optimal experimental conditions could be established in order to identify if NM pose a threat to human health. Multidisciplinary research between materials scientists and life scientists should overcome these limitations in identifying the true hazards of NM.
Neurotoxic effect of occupational exposure to mixed organic solvents in Korea: Posturographic study
Authors: Park Jae‐Beom , Lee Kyung‐Jong , Lee Keou‐Weon , Lim Kwang‐Jin
Published: February 2009

Background

This study used static posturography to investigate the neurotoxic effects on workers exposed to mixed organic solvents at low concentrations under the levels of the threshold limit values (TLV).

Methods

Forty‐one workers from four plants exposed to mixed solvents and 90 non‐exposed referents were examined. The lifetime cumulative biological exposure (CE) was estimated according to subject's occupational history and biological monitoring results. Static posturography and questionnaire were the basis of data collection.

Results

The mean exposure index of mixed organic solvents of four plants was 0.47 (SD: 0.33, range: 0.08–1.39). The exposed group showed a larger sway area and length under the eye open condition than did the non‐exposed group. In a multiple linear regression, a significant positive association was demonstrated between postural sway area and CE.

Conclusions

This study results suggest that the exposure to organic solvents under TLV levels may cause disturbance in postural stability. Am. J. Ind. Med. 52:429–437, 2009. © 2009 Wiley‐Liss, Inc.
Primary hypogonadism, partial alopecia, and Mullerian hypoplasia: Report of a third family and review
Authors: Tatar Abdulgani , Ocak Zeynep , Tatar Arzu , Yesilyurt Ahmet , Borekci Bunyamin , Oztas Sitki
Published: February 2009

Two sisters presented with partial alopecia, primary hypergonadotropic hypogonadism and Mullerian hypoplasia associated with mild mental retardation, microcephaly, flat occiput, sparse eyebrows, absence of breast tissue, absent ovaries, mild‐moderate dorsal kyphosis, thin upper lip and unilateral sensorioneural deafness in one of them. They were the product of a Turkish consanguineous marriage. The clinical course for our patients is similar to two families reported by Al‐Awadi et al. [Al‐Awadi et al. (1985) Am J Med Genet 22:619–622] and Megarbane et al. [Megarbane et al. (2003) Am J Med Genet Part A 119A:214–217]. This report supports the literature by proposing an autosomal recessive syndrome which was firstly reported by Al‐Awadi et al. [Al‐Awadi et al. (1985) Am J Med Genet 22:619–622]. This condition may be due to a founder mutation. © 2009 Wiley‐Liss, Inc.
Novel UBE3A mutations causing Angelman syndrome: Different parental origin for single nucleotide changes and multiple nucleotide deletions or insertions
Authors: Camprubí Cristina , Guitart Miriam , Gabau Elisabeth , Coll Maria Dolors , Villatoro Sergi , Oltra Silvestre , Roselló Monica , Ferrer Irene , Monfort Sandra , Orellana Carmen , Martínez Francisco
Published: February 2009

Angelman syndrome (AS) is a genetic disorder caused by a deficiency of UBE3A imprinted gene expression from the maternal chromosome 15. In 10% of AS cases the genetic cause is a mutation affecting the maternal copy of the UBE3A gene. In two large Spanish series of clinically stringently selected and nonstringently selected patients, we have identified 11 pathological mutations—eight of them novel mutations—and 14 sequence changes considered polymorphic variants. Remarkably, single nucleotide substitutions are more likely to be inherited, while multiple nucleotide deletions or insertions are less frequently inherited, thus indicating that single nucleotide substitutions are more likely to originate from the paternal germline. Additionally, there seems to be a different distribution of nucleotide changes and multiple nucleotide deletions or insertions along the UBE3A gene sequence. © 2009 Wiley‐Liss, Inc.
Juvenile macular dystrophy and forearm pronation‐supination restriction presenting with features of distal arthrogryposis type 5
Authors: Castori Marco , Rinaldi Rosanna , Barboni Luana , Tanzilli Paolo , Bamshad Michael , Grammatico Paola
Published: February 2009

The distal arthrogryposes are a heterogeneous group of conditions characterized by congenital contractures of hands and feet, and autosomal dominant inheritance. The concurrence of ophthalmoplegia and additional ocular findings distinguish distal arthrogryposis type 5 (DA5). This rare subtype has been described in 33 patients to date and its clinical spectrum of physical findings is still poorly understood. We report on a family with three individuals with DA5. The index case came to our attention because of restricted forearm pronation‐supination and juvenile macular dystrophy. Further examination revealed short stature, firm muscles, stiff spine with lumbar hyperlordosis, generalized mild limitation of the large joints, external rotation of the hips, unilateral ptosis, exophoria, and abnormal photopic and scotopic responses on electroretinogram testing. However, there was no overt evidence of contractures of the distal joints. Examination of other affected family members revealed restricted range of movement of the small joints together with ulnar deviation of the fingers, and clarified the diagnosis. Our observations suggest that DA5 may have a very mild musculoskeletal phenotype and it should be considered in the differential of congenital contracture syndromes even in the absence of obvious distal joint involvement. Our observations also suggest that fundoscopy and ocular electrophysiological studies might be helpful in the evaluation of patients with otherwise unclassified distal arthrogryposes. Am. J. Med. Genet. © 2009 Wiley‐Liss, Inc.
Molecular breakpoint mapping of 6q11‐q14 interstitial deletions in seven patients
Authors: Wang Jia‐Chi , Dang Linda , Lomax Brenda , Turner Lesley , Shago Mary , Teebi Ahmad S. , Klatt Regan , MacLeod Patrick M. , Yong Siu‐Li , Nowaczyk Malgorzata J.M. , Eydoux Patrice
Published: February 2009

Interstitial deletions involving 6q11‐q14 have been reported in less than 20 patients, with the breakpoints studied by G‐banding alone. We report on seven patients with 6q11‐q14 interstitial deletions of variable size. The breakpoints were studied by G‐banding, dual‐color BAC‐FISH and SNP array. The results showed the molecular breakpoints differed significantly from the ones obtained from G‐banding. The breakpoints studied by BAC‐FISH were consistent with the ones from SNP array. Some characteristics from this cohort are consistent with previous reports, but many typical features are lacking in our patients. The cardinal features of 6q11‐q14 interstitial deletions in this cohort include: umbilical hernia, hypotonia, short stature, characteristic facial features of upslanting palpebral fissures, low set and/or dysplastic ears, high arched palate, urinary tract anomalies, and skeletal/limb anomalies. © 2009 Wiley‐Liss, Inc.
Nickel‐Catalyzed Borylative Coupling of Alkynes, Enones, and Bis(pinacolato)diboron as a Route to Substituted Alkenyl Boronates
Authors: Mannathan Subramaniyan , Jeganmohan Masilamani , Cheng Chien‐Hong
Published: February 2009

Dreikomponentenkupplungen mit einem Alkin, einem Enon und einem Diborreagens eröffnen den Zugang zu hoch substituierten Alkenylboronaten in guten bis hervorragenden Ausbeuten (siehe Schema). Die Kupplung verläuft hoch regio‐ und stereoselektiv, und die Produkte lassen sich anschließend noch weiter modifizieren. R1,R2=H, Alkyl, Aryl, CO2Me; R3=Alkyl, Ph; R4,R5=H, Alkyl.

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Raman‐spektroskopische Studie der Phasenumwandlung von amorpher in kristalline β‐Kohlensäure
Authors: Kohl Ingrid , Winkel Katrin , Bauer Marion , Liedl Klaus R. , Loerting Thomas , Mayer Erwin
Published: February 2009

Hilfreiche Labordaten für die Detektion von Kohlensäure auf der Oberfläche der Mars‐Polkappen, wenn 2009 das Mars‐Microbeam‐Raman‐Spektrometer wie geplant auf dem Mars landet, bieten die hier vorgestellten Raman‐Spektren von Kohlensäure (H2CO3), und zwar sowohl vom β‐Polymorph als auch vom amorphen Zustand. Der Bildhintergrund zeigt einen Marskrater mit Eis unbekannter Zusammensetzung, in dem möglicherweise Kohlensäure existiert (Überarbeitung eines Bildes der deutschen Marskamera, mit Erlaubnis von ESA, DLR und FU Berlin – G. Neukum).

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Spider Silk: From Soluble Protein to Extraordinary Fiber
Authors: Heim Markus , Keerl David , Scheibel Thomas
Published: February 2009

On a silky thread: Spider silks have mechanical properties that outperform most natural and synthetic fibers. Classical spinning methods have failed to mimic the highly complex natural in‐vivo spinning process. Analyzing this process in combination with in‐vitro findings allows the development of biomimetic spinning devices for the technical production of silk fibers (see picture).

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Spider silks outrival natural and many synthetic fibers in terms of their material characteristics. In nature, the formation of a solid fiber from soluble spider silk proteins is the result of complex biochemical and physical processes that take place within specialized spinning organs. Herein, we present natural and artificial silk production processes, from gene transcription to silk protein processing and finally fiber assembly. In‐vivo and in‐vitro findings in the field of spider silk research are the basis for the design of new proteins and processing strategies, which will enable applications of these fascinating protein‐based materials in technical and medical sciences.
Coordination Polymers: From Metal–Organic Frameworks to Spheres
Authors: Champness Neil R.
Published: February 2009

Sphere of destiny: Metal–organic spheres with remarkable encapsulation properties are readily prepared and their ability to host a wide range of guest species, including nanoparticles, fluorescent dyes, and quantum dots, is demonstrated. Both the metal–organic spheres and the encapsulated species maintain their fluorescent or magnetic properties, highlighting the importance of these systems as new multifunctional materials.

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Wear of the artificial hip joint material under lubrication
Authors: Waters E. P. J. , Spedding P. L. , Doherty A.P. , Spedding R. L.
Published: February 2009

A study of wear properties of hip‐replacement materials, namely high‐nitrogen stainless‐steel femoral heads and ultra‐high molecular weight polyethylene (UHMWPE), was conducted in a non‐conforming apparatus using various liquid lubricants. The liquids used were normal saline solution, sodium azide solution, pure ethanol, aqueous hyaluronic acid and aqueous hyaluronic acid/cholesterol and cholesterol palmitate liquid crystal lubricant. Saline solution proved to be unsuitable as a lubricant while sodium azide that was used as a bactericide provided some evidence of mixed lubrication. A bactericide was included to overcome degradation. The aqueous hyaluronic acid exhibited cushion form lubrication as evidenced by retention of the original polymer surface features within the wear indent. Cholesterol addition showed little improvement on the wear properties but massively increased the bacterial activity. Again, inclusion of a bactericide was necessary. Liquid crystal lubricant significantly reduced wear and the atomic force microscope (AFM) showed that the liquid crystal formed protective layers on the counter face surfaces. The sub‐surface of the polymer possessed plastic creep under load but low adhesive wear was present. There also was an absence of sub‐micron polymer debris. It was concluded that a dramatic reduction in wear could be achieved by incorporation of liquid crystal lubricant in hip‐replacement elements. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
New type of phenolic resin: Curing reaction of phenol‐novolac based benzoxazine with bisoxazoline or epoxy resin using latent curing agent and the properties of the cured resin
Authors: Kimura Hajime , Matsumoto Akihiro , Ohtsuka Keiko
Published: February 2009

In this study, we aimed to reduce the cure time, and to lower the cure temperature of the benzoxazine compound. Therefore, curing reaction of benzoxazine with bisoxazoline or epoxy resin using the latent curing agent and the properties of the cured resins were investigated. The cure behavior of benzoxazine with bisoxazoline or epoxy resin using the latent curing agent was monitored by differential scanning calorimetry and measurements for storage modulus (G′). The properties of the cured resin were estimated by mechanical properties, electrical insulation, water resistance, heat resistance, and flame resistance. As a result, it was confirmed that by using the latent curing agent, cure time of benzoxazine and bisoxazoline or epoxy resin was reduced, and cure temperature was lowered. And it was found that the curing reaction using phenol‐novolac based benzoxazine (Na) as the benzoxazine compound could proceed more rapidly than that using bisphenol‐A based benzoxazine (Ba) as the benzoxazine compound. However, the cured resins from Ba and bisoxazoline or epoxy resin using the latent curing agent showed good heat resistance, flame resistance, and mechanical properties compared with those from Na and bisoxazoline or epoxy resin using the latent curing agent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of functionalized MWNTs with GMA on the properties of PMMA nanocomposites
Authors: Zheng Yaping , Zhang Jiaoxia , Xiaodong Yang , Chen Weiwei , Wang Rumin
Published: February 2009

The acid modification of multiwall carbon nanotubes (MWNTs) was performed by an HNO3/H2SO4 solution. The glycidyl methacrylate (GMA) undergoing an opening‐ring was grafted onto the surface of acid‐modified MWNTs. The surface properties of MWNTs were investigated by Fourier transform infrared spectrometer (FTIR), Raman spectra, transmission electron microscopy (TEM), X‐ray diffraction, and thermogravimeric analysis. Then the MWNTs/ poly(methyl methacrylate) (PMMA) nanocomposites were prepared by in situ polymerization. The tribological and dielectric properties of nanocomposites were studied. As a result, GMA was grafted on the surface of MWNTs. The tribological and dielectric properties of MWNTs/ PMMA nanocomposites were improved as the content of the surface‐modified MWNT increased. The marked improvement in tribological and dielectric properties were attributed to the good dispersion of MWNTs that were bonded with CC on the surface that participated in the polymerization of MMA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Enzymatic degradation of hyperbranched polyesters
Authors: Mallepally Rajendar Reddy , Smirnova Irina , Arlt Wolfgang , Seiler Matthias , Klee‐Laquai Saskia K. , Hills Geoffrey
Published: February 2009

In this work, the enzyme‐catalyzed degradation of hyperbranched polyesters (HBPEs) was investigated. Enzymatic degradation experiments were performed in a phosphate buffer in the presence of the lipases Candida cylindracea, Pseudomonas cepacia, Novozym 388, Amano CE, Lipomod 34P, and Cal‐B, whereas control experiments were performed in the same system without lipases. The extent of polymer degradation was determined by quantification of the released free fatty acids by gas chromatography. The influence of the alkane chain length and the number of alkane chain end groups on the lipase‐catalyzed hydrolysis of esterified HBPEs was investigated systematically. It was found that the increase in the alkane chain length of the end groups diminished the enzymatic degradation of the polymer, whereas the number of end groups had no influence on the degradation rate. The effect of temperature on the rate of degradation was also described. Surface morphological changes that occurred during the degradation were assessed with reflected electron microscopy. The changes in the crystallinity of the polymers after they were subjected to degradation were qualitatively determined with differential scanning calorimetry through the quantification of the enthalpy of melting. The enthalpy of melting of one HBPE sample increased from 79 to 90 and 94 J/g with and without the action of Lipomod 34P, respectively, in 7 days, showing the changes in the crystallinity of the polymer. The results prove that modified HBPEs are an important new class of biodegradable materials with a predictable degradation mechanism, and the degradation can be adjusted on the basis of the molecular engineering. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
PVDF/PMMA composite nanofiber fabricated by electrospray deposition: Crystallization of PVDF induced by solvent extraction of PMMA component
Authors: Danno T. , Matsumoto H. , Nasir M. , Minagawa M. , Horibe H. , Tanioka A.
Published: February 2009

The crystallization of poly(vinylidene fluoride) (PVDF) was observed after the poly(methyl methacrylate) (PMMA) component was extracted from the PVDF/PMMA (50/50) composite nanofiber fabricated by electrospray deposition, even though the original composite showed a completely amorphous pattern in the wide‐angle X‐ray diffraction. The content of the β‐crystal form in the crystalline region depended on the PVDF/PMMA composite ratios and the type of solvents used for the extraction of the PMMA component, e.g., chloroform and toluene. Thus, the content of the β‐crystal form can be controlled by selecting the original PVDF/PMMA composition and the solvent used to extract the PMMA component. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mechanical, vulcametric, and thermal properties of the different 5‐ethylidene 2‐norbornene content of ethylene‐propylene‐diene‐monomer vulcanized with different types and compositions of peroxides
Authors: Çavdar Seda , Özdemir Tonguç , Usanmaz Ali
Published: February 2009

Ethylene‐propylene‐diene‐monomer (EPDM) rubber is an important commercial polymer. The vulcanization process significantly changes its thermal, mechanical, and vulcametric properties. This study was carried out to find optimum formulation of EPDM composite for a better application in automotive industry. Sixteen EPDM polymer samples having different 5‐ethylidene 2‐norbornene (ENB) and ethylene contents were vulcanized with different types and compositions of peroxide and coagents. The mechanical and vulcametric properties of these samples were measured and compared. The type of peroxide, coagent, and EPDM grade affected the mechanical, thermal, and vulcametric properties of the EPDM rubber to some extend. Use of aromatic peroxide and coagent increased the thermal stability slightly. Mechanical properties were changed very slightly with the change of peroxide type for the same content of peroxide and coagent. Scorch time and cure time decreased with initial increase of the peroxide content. EPDM compound vulcanized with BBPIB peroxide and TAC/S coagent has higher cure time than EPDM compound vulcanized with DMBPHa peroxide and TMPTMA coagent. Coran method was used for the modeling of experimental data. Velocity constant for the formation of peroxide radical and polymer radical were found for each case. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of prepolymerization on propylene polymerization
Authors: Monji Majid , Abedi Sadegh , Pourmahdian Saeed , Taromi Faramarz Afshar
Published: February 2009

Polymerization of propylene was performed using MgCl2. EtOH.TiCl4.ID.TEA.ED catalyst system in hexane, where internal donor (ID) was an organic diester and external donor (ED) was a silane compound and also triethyl aluminum (TEA) as activator. A new method called isothermal/nonisothermal method (INM), a combination of isothermal and nonisothermal methods, was applied to produce the spherical polymer particles. The effects of the INM method and prepolymerization temperature on the final polymer morphology, Mw, and catalyst activity were also investigated. The morphology of the polymers was evaluated through scanning electron microscopy (SEM) images. GPC results were used for molecular weight (Mw) evaluation. It was found that the polymers had a better morphology when they were prepared using INM method. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of LCP and rPET as reinforcing materials on rheology, morphology, and thermal properties of in situ microfibrillar‐reinforced elastomer composites
Authors: Saikrasun Sunan , Limpisawasdi Panpirada , Amornsakchai Taweechai
Published: February 2009

Microfibrillar‐reinforced elastomer composites based on two dispersed phases, liquid crystalline polymer (LCP) and recycled poly(ethylene terephthalate)(rPET), and styrene‐(ethylene butylene)‐styrene (SEBS) were prepared using extrusion process. The rheological behavior, morphology, and thermal stability of SEBS/LCP and SEBS/rPET blends containing various dispersed phase contents were investigated. All blends and LCP exhibited shear thinning behavior, whereas Newtonian fluid behavior was observed for rPET. The incorporation of both LCP and rPET into SEBS significantly improved the processability by bringing down the melt viscosity of the blend system. The fibrillation of LCP dispersed phase was clearly observed in as‐extruded strand with addition of LCP up to 20–30 wt %. Although the viscosity ratio of SEBS/rPET system is very low (0.03), rPET domains mostly appeared as droplets in as‐extruded strand. The results obtained from thermogravimetric analysis suggested that an addition of LCP and rPET into the elastomer matrix improved the thermal resistance significantly in air but not in nitrogen. The simultaneous DSC profiles revealed that the thermal degradation of all polymers examined were endothermic and exothermic in nitrogen and in air, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The design of a test protocol to model the degradation of polyolefins during recycling and service life
Authors: Strömberg Emma , Karlsson Sigbritt
Published: February 2009

In terms of the sustainable development for polymeric materials the recovery of plastic waste by means of mechanical recycling is a favorable technique. The largest part of the collected plastic municipal solid waste fraction consists of packaging materials, e.g., polypropylene (PP) and polyethylene. A major drawback to the increased use of recycled polymers is the lack of knowledge about the property changes and the overall quality of the recyclates, e.g., the degree of degradation, mixing, and contamination. This article presents a test protocol for description of the mechanical, physical, and chemical property changes during recycling and service life by combining several reprocessing cycles and thermo‐oxidation. The test protocol was designed to mimic the degradation mechanisms potentially occurring in the materials during the service life and the reprocessing. Virgin PP and HDPE were multiply processed by injection molding. Service life of plastic materials was modeled by accelerated thermal degradation of one time processed materials. Tensile testing, MFR, HT‐SEC, DSC, FTIR, and SEM were used to analyze material changes. In parallel, a set of industrially recycled PP and HDPE were also subjected to the same analyses. The results proved that recycled plastics maintain the majority of the material properties even when reprocessed several times. It was demonstrated that the mechanical and thermal properties of PP and HDPE were preserved also after several reprocessing steps. Initiation of degradation was observed for PP but not for HDPE. A decrease in Mw of PP from 240,000 to 190,000 (six times reprocessed) was established, this corresponds to an increase in MFR from 8 to 18 g/10 min. By FTIR, it was shown that the carbonyl index increased. The loss of stabilizers affects the properties of the final product. In comparison, industrially recycled PP and HDPE presented to some extent poorer mechanical properties than the materials subjected to model recycling. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of plasma‐polymerized 3‐quinolinecarbonitrile and its photo(electro)‐luminescence properties
Authors: Zhao Xiong‐Yan
Published: February 2009

A novel plasma‐polymerized 3‐quinolinecarbonitrile (PP3QCN) thin film was prepared by plasma polymerization of 3‐quinolinecarbonitrile (3QCN) for the first time. The PP3QCN thin films show a blue emission with a narrow peak at ∼ 475 nm and there appeared a relatively high intensity of PL peak. The EL devices with PP3QCN as electroluminescent layer sandwiched between ITO and Al were fabricated. It was found that the ITO/PP3QCN/Al devices also show a blue emission and PP3QCN thin film was stable and appropriate for the electroluminescent layer. The external quantum efficiency of ITO/PP3QCN/Al devices can reach to 0.0068%. The plasma‐polymerized conjugated polynitrile thin film obtained from 3QCN precursor might be a promising material for application in LED and photodiode device. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetic degradation and controlled drug delivery system studies for sensitive hydrogels prepared by gamma irradiation
Authors: Eid M. , El‐Arnaouty M. B.
Published: February 2009

Ternary mixtures of N‐vinyl‐2‐pyrrolidone/itaconic acid and gelatin were irradiated by gamma rays at 30 kGy/s and at ambient temperature to prepared poly (NVP/IA and G) hydrogels. Poly (NVP/IA) hydrogels were prepared in different compositions (NVP/IA) mole ratio, (100/0), (98/1.5), (96.5/3.5), and (93/7.0) at 30 kGy. Then adding gelatin at different content (5, 10, 15, 20) mg to the best composition (NVP/IA/H2O) (93/7)% for the characterization of network structure of these hydrogels, kinetic swelling drug release behavior and Scan Electron Microscope was studied. The equilibrium degree of swelling for P(NVP/IA) and P(NVP/IA/G) copolymer and the swelling‐degradation kinetics were also studies. According to dynamic swelling studies, both the diffusion exponent and the diffusion coefficient increase with increasing content of (IA), whereas, the addition of gelatin to (NVP/IA) composition by different content did not lead to any significant change in swelling percent. Also, the swelling behavior of copolymer hydrogels in response to pH value of the external media was studied, it is noted that the highest swelling values were at pH 4. The in vitro drug release behavior of these hydrogels was examined by quantification analysis with a UV/VIS spectrophotometers. Chlorpromazine hydrochloride was loaded into dried hydrogels to investigate the stimuli‐sensitive property at the specific pH and the drug release profile of these pH‐sensitive hydrogels in vitro. The release studies show that the highest value of release was at pH 4 which can be used for drug delivery system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improving interfacial adhesion between thermoplastic polyurethane and copper foil using amino carboxylic acids
Authors: Ghosh Arun , Schiraldi David A.
Published: February 2009

A chemical methodology to improve the adhesion between copper foil and a thermoplastic polyurethane (TPU) matrix is reported. The copper foil (0.127 mm thickness) was treated with aminocarboxylic acid‐based coupling agents such as 6‐aminohexanoic acid and 4‐aminobenzoic acid. 3‐Aminopropyl trimethoxysilane was also used as a conventional silane coupling agent for comparative studies. The interfacial adhesion between copper foil and laminated TPU was examined by means of peel adhesion test, scanning electron microscopy, and attenuated total reflection‐infrared spectroscopic methods. The treatment of copper foils with 6‐aminohexanoic acid resulted in improved adhesion, which was equal to that of the silane‐treated system. The mechanism of how the coupling agents strengthen the interfacial adhesion between TPU and copper foil is discussed. The solution concentrations of the coupling agents were optimized with respect to the peel adhesion of the interface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Limited proteolysis analysis of the ribosome is affected by subunit association
Authors: Hamburg Daisy‐Malloy , Suh Moo‐Jin , Limbach Patrick A.
Published: February 2009

Our understanding of the structural organization of ribosome assembly intermediates, in particular those intermediates that result from misfolding leading to their eventual degradation within the cell, is limited because of the lack of methods available to characterize assembly intermediate structures. Because conventional structural approaches, such as NMR, X‐ray crystallography, and cryo‐EM, are not ideally suited to characterize the structural organization of these flexible and sometimes heterogeneous assembly intermediates, we have set out to develop an approach combining limited proteolysis with matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) that might be applicable to ribonucleoprotein complexes as large as the ribosome. This study focuses on the limited proteolysis behavior of appropriately assembled ribosome subunits. Isolated subunits were analyzed using limited proteolysis and MALDI‐MS and the results were compared with previous data obtained from 70S ribosomes. Generally, ribosomal proteins were found to be more stable in 70S ribosomes than in their isolated subunits, consistent with a reduction in conformational flexibility on subunit assembly. This approach demonstrates that limited proteolysis combined with MALDI‐MS can reveal structural changes to ribosomes on subunit assembly or disassembly, and provides the appropriate benchmark data from 30S, 50S, and 70S proteins to enable studies of ribosome assembly intermediates. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 410–422, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Detecting cellulase penetration into corn stover cell walls by immuno‐electron microscopy
Authors: Donohoe Bryon S. , Selig Michael J. , Viamajala Sridhar , Vinzant Todd B. , Adney William S. , Himmel Michael E.
Published: February 2009

In general, pretreatments are designed to enhance the accessibility of cellulose to enzymes, allowing for more efficient conversion. In this study, we have detected the penetration of major cellulases present in a commercial enzyme preparation (Spezyme CP) into corn stem cell walls following mild‐, moderate‐ and high‐severity dilute sulfuric acid pretreatments. The Trichoderma reesei enzymes, Cel7A (CBH I) and Cel7B (EG I), as well as the cell wall matrix components xylan and lignin were visualized within digested corn stover cell walls by immuno transmission electron microscopy (TEM) using enzyme‐ and polymer‐specific antibodies. Low severity dilute‐acid pretreatment (20 min at 100°C) enabled <1% of the thickness of secondary cell walls to be penetrated by enzyme, moderate severity pretreatment at (20 min at 120°C) allowed the enzymes to penetrate ∼20% of the cell wall, and the high severity (20 min pretreatment at 150°C) allowed 100% penetration of even the thickest cell walls. These data allow direct visualization of the dramatic effect dilute‐acid pretreatment has on altering the condensed ultrastructure of biomass cell walls. Loosening of plant cell wall structure due to pretreatment and the subsequently improved access by cellulases has been hypothesized by the biomass conversion community for over two decades, and for the first time, this study provides direct visual evidence to verify this hypothesis. Further, the high‐resolution enzyme penetration studies presented here provide insight into the mechanisms of cell wall deconstruction by cellulolytic enzymes. Biotechnol. Bioeng. 2009;103: 480–489. © 2009 Wiley Periodicals, Inc.
3D‐CAD learning environment through interactive modular system (AIMECDT‐3D)
Authors: Pando Cerra Pablo , Alvarez Peñin Pedro , Garcia Diaz Rafael , Perez Morales Maximo
Published: February 2009

The herein presented application allows the betterment of the learning process of 3D‐Computer Assisted Design. In this way the student can easily develop the necessary skills as to the use of the tools by following a regular procedure for grasping the knowledge. For this she/he may use an exercise organizer. Besides, the teacher is allowed to customize the contents and control all the information. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 93–107, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20203
If the Cluster Were a Cluster: The Active Centre of Nitrogenase Revisited
Authors: Kühl Olaf
Published: February 2009

The electronic and physical structure of the active centre of nitrogenase is described from an inorganic point of view, the central main‐group element is determined and its role within the cluster is explained.

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pH‐Dependent Optical Properties of Synthetic Fluorescent Imidazoles
Authors: Berezin Mikhail Y. , Kao Jeff , Achilefu Samuel
Published: February 2009

New pH‐sensitive probe design: A peek into the structure of fluorescent proteins led to the synthesis of fluorescent imidazoles. The prepared compounds demonstrated an array of remarkable pH‐dependent optical properties including at least two types of excited‐state charge transfers (see picture).

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An imidazole moiety is often found as an integral part of fluorophores in a variety of fluorescent proteins and many such proteins display pH‐dependent light emission. In contrast, synthetic fluorescent compounds with incorporated imidazoles are rare and have not been studied as pH probes. In this report, the richness of imidazole optical properties, including pH sensitivity, was demonstrated by means of a novel imidazole‐based fluorophore 1H‐imidazol‐5‐yl‐vinylbenz[e]indolium. Three species corresponding to protonated, neutral, and deprotonated imidazoles were identified in the broad range of pH 1–12. The absorption and emission bands of each species were assigned by comparative spectral analysis with synthesized mono‐ and di‐N‐methylated fluorescent imidazole analogues. pKa analysis in the ground and the excited states showed photoacidic properties of the fluorescent imidazoles due to the excited state proton transfer (ESPT). This effect was negligible for substituted imidazoles. The assessment of a pH‐sensitive center in the imidazole ring revealed the switching of the pH‐sensitive centers from 1‐N in the ground state to 3‐N in the excited state. The effect was attributed to the unique kind of the excited state charge transfer (ESCT) resulting in a positive charge swapping between two nitrogens.
Cyclic RGD‐Containing Functionalized Azabicycloalkane Peptides as Potent Integrin Antagonists for Tumor Targeting
Authors: Manzoni Leonardo , Belvisi Laura , Arosio Daniela , Civera Monica , Pilkington‐Miksa Michael , Potenza Donatella , Caprini Andrea , Araldi Elena M. V. , Monferini Eugenia , Mancino Monica , Podestà Francesca , Scolastico Carlo
Published: February 2009

Vitronectin receptors αvβ3 and αvβ5 have emerged as potential therapeutic targets for the treatment of osteoporosis, restenosis, ocular disease, tumor‐induced angiogenesis, metastasis, and sickle‐cell anemia. Among a collection of compounds, a new potent integrin antagonist was synthesized, and its binding toward the αvβ3 and αvβ5 receptors was evaluated. This molecule is a suitable candidate as a vector for therapeutics and diagnostics.

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Cyclic RGD‐containing functionalized azabicycloalkane peptides were synthesized with the aim of developing high‐affinity selective integrin ligands as carriers for therapeutic and diagnostic purposes. Herein we describe the synthesis and in vitro screening of these RGD derivatives, as well as the determination of their conformational properties in solution by spectroscopic and computational methods. Docking studies with the X‐ray crystal structure of the extracellular domain of integrin αvβ3 were also performed to elucidate the structural binding requirements and to rationalize the biological results. One compound in particular was found to be the best αvβ3 integrin binder (IC50=53.7 nM) among the new functionalized RGD cyclic peptides, thus emerging as a promising candidate for covalent bonding and selective homing of useful functional units.
Dose‐escalated radiation therapy for intermediate‐risk prostate cancer
Authors: Liauw Stanley L. , Fricano Janine , Correa David , Weichselbaum Ralph R. , Jani Ashesh B.
Published: February 2009

BACKGROUND:

Randomized trials supported the use of androgen deprivation therapy (ADT) with radiation therapy (RT) for intermediate‐risk prostate cancer. However, the value of concurrent ADT was less certain with dose‐escalated RT. Better methods of stratifying patients in this risk group may help select patients who are most likely to benefit.

METHODS:

A total of 238 men with intermediate‐risk (prostate specific antigen [PSA] 10‐20, Gleason 7, or stage T2b‐c) adenocarcinoma of the prostate were treated with external beam RT between 1989 and 2006. Patients had Gleason≤6 (39%) or 7 (61%) tumors; median PSA was 10.5 ng/mL. A median of 37.5% of biopsy cores were positive from a median of 9 biopsy cores sampled. The median RT dose was 74 Gy to the prostate. A total of 112 patients (47%) received neoadjuvant and concurrent ADT (median, 4 months). Median follow‐up period was 49 months.

RESULTS:

The freedom from biochemical failure (FFBF, nadir + 2 definition) was 93% at 3 years, 86% at 4 years, and 80% at 5 years. On univariate analysis, the only factor associated with FFBF was percentage of positive cores (PPC, P = .0340). The prognostic value of PPC≥50 was not evident in patients receiving ADT (FFBF at 4 years 90% vs 91%, P = .3015). For patients not receiving ADT, the impact of PPC≥50 (FFBF at 4 years 76% vs 93%, P = .0844) was more pronounced. On multivariate analysis, PPC (P = .0388) was significantly associated with FFBF, whereas Gleason sum, ADT, RT dose, PSA, and T‐stage were not.

CONCLUSIONS:

After dose‐escalated external beam RT, intermediate‐risk prostate cancer patients with PPC≥50 had the highest risk for biochemical failure and may be most likely to derive a benefit from ADT. Cancer 2009. © 2009 American Cancer Society.
Identification of 12 or more lymph nodes in resected colon cancer specimens as an indicator of quality performance
Authors: Dillman Robert O. , Aaron Kenneth , Heinemann F. Scott , McClure Stephanie E.
Published: February 2009

BACKGROUND:

Identification of ≥12 lymph nodes in resected colon cancer specimens has been endorsed as a quality indicator.

METHODS:

The Hoag Hospital cancer registry was used to identify patients diagnosed with colon cancer. The proportion of colon cancer specimens for which ≥12 lymph nodes were identified was determined by anatomic location, stage of disease, patient age, and operating surgeon. Survival was correlated with stage and with whether ≥12 lymph nodes were identified.

RESULTS:

Pathology procedural changes in 1998 were associated with an increase in the average number of lymph nodes identified from 8.0 to 14.5 (P < .0001); therefore, analysis was limited to 574 patients who underwent surgical resection of colon adenocarcinoma during 1998 to 2005. Identification of ≥12 lymph nodes varied from 57% to 83% by 7 anatomic locations (P < .0001), from 65% to 75% by 5 age cohorts (P = .027), from 59% to 73% by 4 general stages of disease (P = .004), and from 53% to 80% among 12 surgeons who performed at least 17 resections (P = .014). The proportion of resections in which ≥12 lymph nodes were identified was higher for 3 colorectal fellowship‐trained surgeons compared with the other 9 surgeons (77% vs 63%, P = .0007), and with 30 surgeons who each performed <10 resections (77% vs 51%, P < .0001). Identification of ≥12 lymph nodes was associated with better survival for patients with stage I (P = .016) and stage II (P = .021) disease.

CONCLUSIONS:

Anatomic location, colorectal surgical training, and case volume were strongly correlated with the number of lymph nodes identified. Cancer 2009. © 2009 American Cancer Society.