bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal snowpack dynamics and runoff in a cool temperate forest: lysimeter experiment in Niigata, Japan
Authors: Whitaker Andrew C. , Sugiyama Hironobu
Published: December 2005

Seasonal snowpack dynamics are described through field measurements under contrasting canopy conditions for a mountainous catchment in the Japan Sea region. Microclimatic data, snow accumulation, albedo and lysimeter runoff are given through the complete winter season 2002–03 in (1) a mature cedar stand, (2) a larch stand, and (3) a regenerating cedar stand or opening. The accumulation and melt of seasonal snowpack strongly influences streamflow runoff during December to May, including winter baseflow, mid‐winter melt, rain on snow, and diurnal peaks driven by radiation melt in spring. Lysimeter runoff at all sites is characterized by constant ground melt of 0·8–1·0 mm day−1. Rapid response to mid‐winter melt or rainfall shows that the snowpack remains in a ripe or near‐ripe condition throughout the snow‐cover season. Hourly and daily lysimeter discharge was greatest during rain on snow (e.g. 7 mm h−1 and 53 mm day−1 on 17 December) with the majority of runoff due to rainfall passing through the snowpack as opposed to snowmelt. For both rain‐on‐snow and radiation melt events lysimeter discharge was generally greatest at the open site, although there were exceptions such as during interception melt events. During radiation melt instantaneous discharge was up to 4·0 times greater in the opening compared with the mature cedar, and 48 h discharge was up to 2·5 times greater. Perhaps characteristic of maritime climates, forest interception melt is shown to be important in addition to sublimation in reducing snow accumulation beneath dense canopies. While sublimation represents a loss from the catchment water balance, interception melt percolates through the snowpack and contributes to soil moisture during the winter season. Strong differences in microclimate and snowpack albedo persisted between cedar, larch and open sites, and it is suggested further work is needed to account for this in hydrological simulation models. Copyright © 2005 John Wiley & Sons, Ltd.
Responses of MC3T3‐E1 cells to three dental resin‐based restorative materials
Authors: Imazato Satoshi , Horikawa Daisuke , Ogata Korenori , Kinomoto Yoshifumi , Ebisu Shigeyuki
Published: December 2005

This study aimed to examine the influences of three dental resin‐based restorative materials on cells associated with hard tissue regeneration using osteoblastic MC3T3‐E1 cells. A Bis‐GMA‐based resin composite [Clearfil AP‐X (APX)], an MMA‐based resin cement [Superbond C&B (SB)], and a resin‐modified glass‐ionomer [Fuji Ionomer Type II LC (LC)] were tested. A zinc oxide eugenol cement [Super EBA (EBA)] was included in the study for comparison. MC3T3‐E1 cells were cultured on set materials for 3, 7, 14, or 21 days. Cell attachment and proliferation were observed by scanning electron microscopy, and mitochondrial dehydrogenase and alkaline phosphatase (ALP) activities of the cells were evaluated. Cell cultures on polystyrene tissue culture dishes served as controls. On APX and SB, cells demonstrated attachment, spreading, and proliferation similar to the controls. In contract, cells adhered and proliferated poorly on LC and EBA. The mitochondrial function and ALP activity of the cells were significantly suppressed (p < 0.05, Scheffe's F test) throughout the experimental period when cultured on LC or EBA, although APX and SB exhibited less inhibition. The results indicate that APX and SB are less toxic to proliferation and differentiation of MC3T3‐E1, suggesting that a smaller influence on cementogenesis on these materials can be expected. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Single dose vaccine based on biodegradable polyanhydride microspheres can modulate immune response mechanism
Authors: Kipper Matt J. , Wilson Jennifer H. , Wannemuehler Michael J. , Narasimhan Balaji
Published: December 2005

This study focuses on the development of single dose vaccines based on biodegradable polyanhydride microspheres that have the unique capability to modulate the immune response mechanism. The polymer system employed consists of copolymers of 1,6‐bis(p‐carboxyphenoxy)hexane and sebacic acid. Two copolymer formulations that have been shown to provide extended release kinetics and protein stability were investigated. Using tetanus toxoid (TT) as a model antigen, in vivo studies in C3H/HeOuJ mice demonstrated that the encapsulation procedure preserves the immunogenicity of the TT. The polymer itself exhibited an adjuvant effect, enhancing the immune response to a small dose of TT. The microspheres provided a prolonged exposure to TT sufficient to induce both a primary and a secondary immune response (i.e., high antibody titers) with high‐avidity antibody production, without requiring an additional administration. Antigen‐specific proliferation 28 weeks after a single immunization indicated that immunization with the polyanhydride microspheres generated long‐lived memory cells and plasma cells (antibody‐secreting B cells) that generally do not occur without maturation signals from T helper cells. Furthermore, by altering the vaccine formulation, the overall strength of the T helper type 2 immune response was selectively diminished, resulting in a balanced immune response, without reducing the overall titer. This result is striking, considering free TT induces a T helper type 2 immune response, and has important implications for developing vaccines to intracellular pathogens. The ability to selectively tune the immune response without the administration of additional cytokines or noxious adjuvants is a unique feature of this delivery vehicle that may make it an excellent candidate for vaccine development. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Human neutrophils reaction to the biodegraded nano‐hydroxyapatite/collagen and nano‐hydroxyapatite/collagen/poly(L‐lactic acid) composites
Authors: Liao Susan , Tamura Kazuchika , Zhu Yuhe , Wang Wei , Uo Motohiro , Akasaka Tsukasa , Cui Fuzhai , Watari Fumio
Published: December 2005

The impact of biodegraded nano‐hydroxyapatite/collagen (nHAC) composite and nano‐hydroxyapatite/collagen/poly(L‐lactic acid) (nHAC/PLA) scaffold composite on neutrophils reaction was evaluated in vitro. Neutrophils were separated from human peripheral blood of healthy subjects. The nHAC and nHAC/PLA materials were immersed in the D‐Hanks' Balanced Salt Solution (D‐HBSS) for 1 day, 7 days and 2, 4, 8 weeks (37°C) as testing solution, which mixed with the neutrophils for 1 h. Both of the nHAC and nHAC/PLA materials were shown the same cell survival rate as blank control, but the lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF‐α) released from the neutrophils were increased significantly after the 2 weeks in nHAC sample. The possible reason relied on the high concentration of calcium due to the quick biodegradation of the nHAC material. Before 2 weeks, the LDH value of nHAC/PLA is higher than that of nHAC sample that corresponded to the initial PLA degradation in vitro. This study provided the biocompatibility test of neutrophils other than common methods, such as osteoblastic cells for biomimetic materials. Moreover, it demonstrated the calcium concentration stimulating effect for cytokine release from neutrophils. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Three‐dimensional nanofibrillar surfaces covalently modified with tenascin‐C‐derived peptides enhance neuronal growth in vitro
Authors: Ahmed Ijaz , Liu Hsing‐Yin , Mamiya Ping C. , Ponery Abdul S. , Babu Ashwin N. , Weik Thom , Schindler Melvin , Meiners Sally
Published: December 2005

Current methods to promote growth of cultured neurons use two‐dimensional (2D) glass or polystyrene surfaces coated with a charged molecule (e.g. poly‐L‐lysine (PLL)) or an isolated extracellular matrix (ECM) protein (e.g. laminin‐1). However, these 2D surfaces represent a poor topological approximation of the three‐dimensional (3D) architecture of the assembled ECM that regulates neuronal growth in vivo. Here we report on the development of a new 3D synthetic nanofibrillar surface for the culture of neurons. This nanofibrillar surface is composed of polyamide nanofibers whose organization mimics the porosity and geometry of the ECM. Neuronal adhesion and neurite outgrowth from cerebellar granule, cerebral cortical, hippocampal, motor, and dorsal root ganglion neurons were similar on nanofibers and PLL‐coated glass coverslips; however, neurite generation was increased. Moreover, covalent modification of the nanofibers with neuroactive peptides derived from human tenascin‐C significantly enhanced the ability of the nanofibers to facilitate neuronal attachment, neurite generation, and neurite extension in vitro. Hence the 3D nanofibrillar surface provides a physically and chemically stabile cell culture surface for neurons and, potentially, an exciting new opportunity for the development of peptide‐modified matrices for use in strategies designed to encourage axonal regrowth following central nervous system injury. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Organic overlayer model of a dental composite analyzed by laser desorption postionization mass spectrometry and photoemission
Authors: Zhou Manshui , Wu Chunping , Edirisinghe Praneeth D. , Drummond James L. , Hanley Luke
Published: December 2005

Some dental composites consist of a polymerizable resin matrix bound to glass filler particles by silane coupling agents. The resin in these composites includes bisphenol A diglycidyl methacrylate (Bis‐GMA) as well as other organic components. Silane coupling agents such as 3‐(trimethoxysilyl) propyl methacrylate (MPS) have been used to improve the mechanical properties of the dental composites by forming a covalent bond between the glass filler particles and the resin. These resin–glass composites undergo material property changes during exposure to the oral environment, but degradation studies of the commercial composites are severely limited by their chemical complexity. A simplified model of the dental composite has been developed, which captures the essential chemical characteristics of the filler particle–silane–resin interface. This model system consists of the resin matrix compound Bis‐GMA covalently bound via a methacryloyl overlayer to amorphous silicon oxide (SiO2) surface via a siloxane bond. Scanning electron microscopy shows the porous characteristic and elemental composition of the SiO2 film, which approximately mimics that of the glass filler particles used in dental composites. LDPI MS and XPS verify the chemistry and morphology of the Bis‐GMA‐methacryloyl overlayer. Preliminary results demonstrate that LDPI MS will be able to follow the chemical processes resulting from aging Bis‐GMA‐methacryloyl overlayers aged in water, artificial saliva, or other aging solutions. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Manufacture of multimicrotubule chitosan nerve conduits with novel molds and characterization in vitro
Authors: Ao Qiang , Wang Aijun , Cao Wenling , Zhang Ling , Kong Lijun , He Qing , Gong Yandao , Zhang Xiufang
Published: December 2005

Multimicrotubule chitosan conduits (M‐conduits) were fabricated using novel molds and a thermal‐induced phase‐separation technique. Hollow chitosan conduits (H‐conduits) with an inner diameter of 1–5 mm and a wall thickness of 0.2–1.0 mm were made, and then a novel mold composed of a styrofoam insulating pedestal with several holes and a stainless steel cover plate was used to make M‐conduits. In brief, corresponding H‐conduits were inserted upright into the holes of the styrofoam pedestal, and filled with chitosan solution, then rapidly covered with the precooled stainless steel cover plate, and then placed in a freezer. The styrofoam insulating pedestal enclosing the conduits could reduce the heat transfer through the side wall of the conduits. Gradual phase separation then occurred uniaxially in the presence of a unidirectional temperature gradient from the top end to the bottom end of the chitosan conduits. The phase‐separated polymer/solvent systems were then dried in a freeze‐dryer. The microtubule diameters were controlled by adjusting the polymer concentration and cooling temperature. In vitro characterization demonstrated that the mold‐based multimicrotubule chitosan conduits possessed suitable mechanical strength, microtubule diameter distribution, porosity, swelling, biodegradability, and nerve cell affinity, and so they showed potential for application as nerve tissue engineering scaffolds. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Role of phase diagram of membrane formation system in controlling the crystallinity and degradation rate of PLLA membranes
Authors: Lee I‐Chi , Cheng Liao‐Ping , Young Tai‐Horng
Published: December 2005

In this work, the theoretical phase diagram of membrane formation system of ethanol, methylene chloride, and poly‐L‐lactide (PLLA) was studied. On the basis of the phase diagram, particulate and porous membranes, dominated by crystallization and liquid–liquid demixing, respectively, were prepared. Furthermore, degradation of PLLA membranes with particulate, porous, and dense morphologies was performed in phosphate buffered solution (PBS) at 37°C for 168 days and was investigated by mass loss, scanning electron microscopy (SEM), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Besides the membrane morphology, a close relationship between the phase behavior of the membrane formation system and the membrane crystallinity was found, which in turn influenced the degradation rate of these membranes significantly. In the case of dense membranes, it showed the lowest initial crystallinity and the greatest rate of mass loss and molecular weight decrease compared with particulate and porous membranes. In contrast, the particulate membranes had the highest crystallinity and the slowest degradation rate in this study. Therefore, the phase diagram of membrane formation system could not only anticipate membrane morphology, but could also control the membrane crystallinity and degradation rate simultaneously. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Thermally responsive polymeric micelles self‐assembled by amphiphilic polyphosphazene with poly(N‐isopropylacrylamide) and ethyl glycinate as side groups: Polymer synthesis, characterization, and in vitro drug release study
Authors: Zhang Jian Xiang , Qiu Li Yan , Jin Yi , Zhu Kang Jie
Published: December 2005

Thermally responsive amphiphilic poly(N‐isopropylacrylamide) (PNIPAm)‐grafted‐polyphosphazene (PNIPAm‐g‐PPP) was synthesized by stepwise cosubstitution of chlorine atoms on polymer backbones with amino‐terminated NIPAm oligomers and ethyl glycinate (GlyEt). Polymer structure was confirmed by FT‐IR, 1H NMR, elemental analysis, and GPC. The thermosensitivity of PNIPAm‐g‐PPP aqueous solution was investigated by turbidity method. The lower critical solution temperature (LCST) of PNIPAm‐g‐PPP was observed to be ∼30°C in water, while it was 24°C in 0.1M PBS (pH 7.4). Micellization behavior of PNIPAm‐g‐PPP in aqueous solution was characterized by fluorescence probe technique, TEM, and DLS. The critical micelle concentration (CMC), thus, determined was 0.0187 g/L. Both TEM and DLS measurement suggested that the diameter of micelles was ∼190 nm at 20°C. Diflunisal (DIF)‐loaded micelles were prepared by dialysis method. In vitro release test at various temperatures was also performed to study the effect of temperature on the drug release profiles. It was demonstrated that DIF release from PNIPAm‐g‐PPP micelles was slower at the temperature of 37°C than that at 4°C. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Asymmetrically functional surface properties on biocompatible phospholipid polymer membrane for bioartificial kidney
Authors: Ueda Hideto , Watanabe Junji , Konno Tomohiro , Takai Madoka , Saito Akira , Ishihara Kazuhiko
Published: December 2005

To obtain a bioartificial kidney composed of a porous polymer membrane and renal cells, a polysulfone (PSf) membrane (PSM) blended with 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymer was prepared. The PSM flat membrane with a porous structure could be prepared from the polymer blend containing 1 wt % of the MPC polymer in PSf by the phase inversion technique in a dry–wet process. Asymmetrical surface properties were observed on both sides of the membrane surfaces. That is, the sponge layer formed at the substrate‐contacting surface of the membrane had 10–20 μm pores, but the pores in the micrometer range could not be observed for a skin layer formed at the air‐contacting surface of the membrane. At the sponge layer surface, the MPC unit composition was 7 times larger than that at the skin layer surface. The amount of proteins adsorbed on the surface corresponded to the MPC unit composition. On the skin layer, a small amount of adsorbed proteins and platelet adhesion could be suppressed compared with those on the sponge layer. However, the skin layer had a moderate protein adsorption, so it showed a sufficient cytocompatibility to enable renal tubule epithelial cells to adhere and proliferate in the membrane. Thus, it functioned well as a renal tubule. Therefore, because of both its hemocompatibility and cytocompatibility, we could conclude that the PSM membrane is useful for as a renal tubule device for a bioartificial kidney. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Effects of the length of crosslink chain on poly(2‐hydroxyethyl methacrylate) (pHEMA) swelling and biomechanical properties
Authors: Mabilleau G. , Stancu I. C. , Honoré T. , Legeay G. , Cincu C. , Baslé M. F. , Chappard D.
Published: December 2005

Polymers are widely used in medicine for vascular prostheses, bone substitutes, and devices for controlled release. Among these polymers, poly(2‐hydroxyethyl methacrylate) (pHEMA) is the most employed. To confer particular properties, pHEMA can be copolymerized with other monomers or in the presence of plasticizers or crosslinking agents. The influence of the length of crosslink chains on swelling, surface rugosity, hardness, and stiffness of crosslinked pHEMA were studied by several techniques, including fractal analysis and AFM. Four crosslinking agents (divinyl benzene, DVB; ethylene glycol dimethacrylate, EGDMA; tetraethylene glycol diacrylate, TEGDA; and polyethylene glycol diacrylate, PEGDA) were added to the bulk polymerization mixture. Only linear and PEGDA–pHEMA presented a significant decrease in surface roughness confirmed by fractal analysis. Differences in hardness and biomechanical properties were evidenced on dried polymers but the highest differences were exhibited for hydrated pHEMA. Correlations between the length of the crosslink chain and hardness or stiffness of hydrated crosslinked pHEMA were evidenced. TEGDA and PEGDA appeared to be the two most suitable crosslinking agents for controlled release of bioactive molecules in bone. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Effects of 58S sol–gel glasses on the temporal expression of bone markers during mouse osteoblastic differentiation
Authors: Hattar S. , Loty S. , Gaisser D. , Berdal A. , Sautier J‐M.
Published: December 2005

Previous studies have shown that bioactive glasses can support osteoblastic growth and differentiation in vitro as well as in vivo. More recently, a new category of sol–gel glasses has been developed with enhanced bioactivity and open pores enclosed in a mesoporous matrix. In our study, we investigated the effect of 58S sol–gel glasses on the growth and differentiation of mouse calvaria osteoblasts. Two types of granules were used: 58S sol–gel granules and 60S inert glasses used as control. Phase contrast microscopy showed that cells proliferated and formed mineralized bone nodules in both cultures. However, this phenomenon occurred earlier and to a higher degree in cultures with 58S sol–gel glasses. Northern blot analysis of the expression of osteoblastic markers revealed that osteoblasts retained their phenotype in both types of cultures. Interestingly, stimulation of alkaline phosphatase, bone sialoprotein, and osteocalcin was noticed at day 18 in sol–gel cultures when compared with that in control. These data confirm that 58S bioactive glasses are capable of supporting the growth and maturation of primary mouse osteoblasts. In addition, it was shown that 58S glasses affected the gene‐expression profile, causing an up‐regulation of the major bone markers. These results indicated that 58S sol–gel glasses appeared as suitable candidates for osteoblast scaffolds in the field of bone tissue engineering. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Anti‐inflammatory properties of micropatterned titanium coatings
Authors: Sahlin Herman , Contreras Ramiro , Gaskill Daniel F. , Bjursten Lars M. , Frangos John A.
Published: December 2005

Prolonged inflammation and reactive oxygen species (ROS) generated around an implanted biosensor are the primary causes of the foreign body response, including encapsulation of biosensor membranes. We have previously demonstrated that TiO2 surfaces reduce ROS. Here we investigated the potential of using the anti‐inflammatory properties of TiO2 in the design of biosensor membranes with improved long‐term in vivo transport properties. Micropatterned Ti films were sputtered onto quartz surfaces in a series of hexagonally distributed dots with identical coverage area of 23% and dot size ranging from 5 to 100 μm. The antioxidant effect of the surfaces was investigated using a cell‐free peroxynitrite donor assay and assays of superoxide released from stimulated surface‐adhering neutrophils and macrophages. In all three assays, the amount of ROS was monitored using luminol‐amplified chemiluminescence. Patterned surfaces in all experimental models significantly decreased ROS compared to the etched surfaces. In the cell‐free experiment, the ROS reduction was only dependent on fractional surface coverage. In the cell experiments, however, a dot‐size‐dependent ROS reduction was seen, with the largest reduction at the smallest dot‐size surfaces. These results indicate that micropatterned surfaces with small dots covering only 23% of the surface area exhibit similar antioxidative effect as fully covered surfaces. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Photochemically enhanced transduction of polymer‐complexed adenovirus targeted to the epidermal growth factor receptor
Authors: Bonsted Anette , Engesæter Birgit Øvstebø , Høgset Anders , Mælandsmo Gunhild M. , Prasmickaite Lina , D'Oliveira Christine , Hennink Wim E. , van Steenis Jan Hein , Berg Kristian
Published: December 2005

Background

The development of methods for specific delivery of genes into target tissues is an important issue for the further progress of gene therapy. Biological and physical targeting techniques may be combined to redirect gene therapy vectors to specific cells and enhance gene transfer.

Methods

The polymer poly(2‐(dimethylamino)ethyl methacrylate) (pDMAEMA) was conjugated with avidin or poly(ethylene glycol) (PEG) and complexed with adenovirus serotype 5 (Ad5). Targeting of polymer‐coated Ad5 to the epidermal growth factor receptor (EGFR) was accomplished by the binding of biotin‐EGF to pDMAEMA‐avidin. A photochemical treatment procedure using photosensitizer and light was applied to increase transduction with EGFR‐targeted viral complexes.

Results

pDMAEMA‐avidin efficiently enhanced transduction through unspecific viral uptake into cells, while pDMAEMA‐PEG provided charge shielding of the complexes and increased the specificity to EGFR when biotin‐EGF ligands were used. Transduction of PEG‐containing, EGFR‐targeted viral complexes was inhibited by 66% in coxsackie and adenovirus receptor (CAR)‐deficient RD cells and by 47% in CAR‐expressing DU 145 cells in receptor antibody experiments. The photochemical treatment had a substantial effect on transduction, enhancing the percentage of reporter gene positive cells from 20% to 75% of the total viable RD cell population and from 10% to 70% in DU 145 cells.

Conclusion

Photochemical treatment of cells infected with targeted viral vectors exhibiting a neutral surface charge is a potent method for enhancing transgene expression. Copyright © 2005 John Wiley & Sons, Ltd.
Medicalizing melancholia: Exploring profiles of psychiatric professionalization
Authors: Misbach Judith , Stam Henderikus J.
Published: December 2005

The nineteenth century was the site of radical changes in understanding mental illness. The professionalization of psychiatry consisted primarily of the discipline's aspiration to the status of an expert medical subspecialty. While all forms of insanity were eventually reframed in medical terms, melancholia—for moral and nosological reasons—assumed a special role that made it an ideal diagnosis for conceptual reframing. Our analysis of the journal literature of the nineteenth and early twentieth centuries in North America and Germany traces several ways in which melancholia was medicalized. As the care for the insane shifted into the professional realm of physicians and medical terminology came to replace prior descriptors of mental illness, melancholia was replaced by depression. In addition, the process of delineating affective pathology assumed a distinctly medical flavor. Finally, melancholia was firmly medicalized when its boundaries blurred with neurasthenia. Differences in how ordinary affective terms became medicalized in German and North American psychiatry illustrate the importance of local historical approaches. © 2006 Wiley Periodicals, Inc.
The lost direction in binocular vision: The neglected signs posted by Wells, Towne, and Leconte
Authors: Wade Nicholas J. , Ono Hiroshi , Mapp Alistair P.
Published: December 2005

Studies of vision have informed theories first in philosophy and then in psychology. Over the centuries, an increasing number of phenomena have been enlisted to refute or reinforce particular theories. Nowhere has this been more evident than in binocular vision. How we see a single world with two eyes is one of the oldest and most consistently studied topics in vision research. It has been discussed at least since the time of Aristotle and it has been examined experimentally since the second century, when Ptolemy defined lines of visual correspondence for the two eyes. Prior to Wheatstone's invention of the stereoscope in the 1830s, binocular vision had been studied in terms of visual directions. The stereoscope established distance (or depth) as well as direction as dimensions of binocular vision. Subsequently, depth rather than direction has been the principal concern of students of vision, and texts in English devoted to analyses of direction rather than depth have been neglected. We examine the experiments on binocular visual direction conducted by Wells before Wheatstone, and by Towne and LeConte after him, and discuss the reasons for their neglect. © 2006 Wiley Periodicals, Inc.
G. H. Mead in the history of sociological ideas
Authors: da Silva Filipe Carreira
Published: December 2005

My aim is to discuss the history of the reception of George Herbert Mead's ideas in sociology. After discussing the methodological debate between presentism and historicism, I address the interpretations of those responsible for Mead's inclusion in the sociological canon: Herbert Blumer, Jürgen Habermas, and Hans Joas. In the concluding section, I assess these reconstructions of Mead's thought and suggest an alternative more consistent with my initial methodological remarks. In particular, I advocate a reconstruction of Mead's ideas that apprehends simultaneously its evolution over time and its thematic breadth. Such a historically minded reconstruction can be not only a useful corrective to possible anachronisms incurred by contemporary social theorists, but also a fruitful resource for their theory‐building endeavors. Only then can meaningful and enriching dialogue with Mead begin. © 2006 Wiley Periodicals, Inc.
Raman spectroscopy of walpurgite
Authors: Frost Ray L. , Weier Matt L. , Čejka Jiří , Theo Kloprogge J.
Published: December 2005

Raman spectra of walpurgite, (UO2)Bi4O4 (AsO4)2·2H2O, recorded at 298 K and 77 K are presented and compared with infrared spectra of walpurgite and phosphowalpurgite. Bands connected with (UO2)2+, (AsO4)3−, and H2O stretch and bend, and BiO stretch are tentatively assigned. Hydrogen bond lengths are calculated from the wavenumbers of the H2O stretching vibrations and compared with those from the crystal structure analysis of walpurgite. Copyright © 2005 John Wiley & Sons, Ltd.
Limonoids as cancer chemopreventive agents
Authors: Ejaz Sohail , Ejaz Ahmed , Matsuda Kiku , Lim Chae Woong
Published: December 2005

Nutritional research on the health benefits of substances in plant foods has recently advanced to a new stage. The research frontier has moved from study of classical vitamin deficiency diseases to study of the thousands of phytochemicals that may have important physiological effects. Recent research suggests that citrus fruit consumers may be getting another health benefit from orange juice and other citrus products called limonoids, which appear to possess substantial anticancer activity. Limonoids are highly oxidized triterpenes present in Rutaceae and Maliaceae families. Several citrus limonoids have recently been subjected to anticancer screening utilizing laboratory animals and human breast cancer cells. The experimental results described that citrus limonoids may provide substantial anticancer actions. The compounds have been shown to be free of toxic effects in animal models, so potential exists for the use of limonoids against human cancer in either natural fruits, in citrus fortified with limonoids, or in purified forms of specific limonoids. Although the initial studies are very promising they have been conducted primarily with in vitro cell culture and animal models. Thus, research is needed to determine whether the limonoids may be useful in preventing or treating cancer in humans. Copyright © 2005 Society of Chemical Industry
Cover Picture: Macromol. Mater. Eng. 12/2005
Authors: Chae Dong Wook , Kim Byoung Chul
Published: December 2005

Cover: The picture on the cover shows the time dependence of the storage modulus (G′) of isotactic poly(propylene) (iPP) and its composites with silver nanoparticles. The promoting effects of silver and shear on the isothermal crystallization behavior of iPP are observed. Further details can be found in the article by D. W. Chae and B. C. Kim* on page 1149.
Infrared Spectroscopic Characterization of Polymer and Clay Platelet Orientation in Blown Films Based on Polypropylene‐Clay Nanocomposite
Authors: Cole Kenneth C. , Perrin‐Sarazin Florence , Dorval‐Douville Geneviève
Published: December 2005

The “tilted film” transmission infrared spectroscopy method was used to characterize the biaxial orientation in a set of blown films containing polypropylene (PP), layered silicate nano‐reinforcement, and two different compatibilizing agents based on maleic‐anhydride‐grafted PP. Both interactive spectral subtraction and peak fitting were used to determine trichroic ratios. The biaxial orientation of the polymer chains could be clearly quantified according to well‐established relationships for PP. In addition, the clay platelet orientation could be determined from the trichroism of the SiO stretching bands around 1100 – 1000 cm−1. The clay orientation was found to be quite high (Hermans orientation function around +0.8) and was not significantly affected by the presence of compatibilizing agent.
Novel Color‐Shifting Mobility Sensitive Fluorescent Probes for Polymer Characterization
Authors: Jager Wolter F. , van den Berg Otto , Picken Stephen J.
Published: December 2005

1‐Methyl‐7‐dimethylamino quinolinium tetrafluoroborate, a highly stable, highly fluorescent color‐shifting mobility sensitive fluorescent probe was employed for detecting the glass transition and phase transitions, notably crystallization, in polymers and polymer blends. Glass transitions in amorphous and semi‐crystalline polymers were detected by a change in gradient in emission wavelength λmax versus T plots. Crystallization resulted in discrete blue shifts in λmax versus T plots. Selective probing of PMMA in a PS/PMMA blend, down to a PMMA content of 1%, was demonstrated. Dielectric relaxation spectroscopy has established a clear link between the mobility of dipoles in PMMA and the emission wavelength of the fluorescent probe.
Spectroscopic Ellipsometry for Characterization of Thin Films of Polymer Blends
Authors: Hinrichs K. , Gensch M. , Nikonenko N. , Pionteck J. , Eichhorn K.‐J.
Published: December 2005

Morphology, composition, miscibility, interdiffusion, and interactions at interfaces are important quantities of polymer blends. Many of these parameters can be probed with spectroscopic ellipsometry. Ellipsometry in the visible spectral range is very suitable for determination of thicknesses and the high frequency refractive indices of thin organic films. However the spectral contrast is low for many polymers in comparison to infrared spectroscopic ellipsometry (IRSE) where specific contributions of the molecular vibrations are probed. In the presented study the infrared optical constants of a double layer (206.6 nm in total) of poly(n‐butyl methacrylate) (PnBMA) and poly(vinyl chloride) (PVC) and of the films of the single compounds have been determined with optical simulations using layer models. The multiple layer model served for simulation of the ellipsometric spectra taken after an annealing induced mixing process in a polymeric double layer. The ellipsometric spectra of a not completely mixed sample could be fitted in a three‐layer model, in which a mixed interphase in between the two layers of the polymers is formed due to interdiffusion.
Blends of Sulfonated Polysulfone and Poly(ethylene oxide)‐Grafted‐Polyethersulfone as Proton Exchange Membranes for Fuel Cell Applications
Authors: Deimede V. , Kandilioti G. , Kallitsis J. K. , Gregoriou V. G.
Published: December 2005

Blends composed of sulfonated polysulfone (SPSF) and poly(ethylene oxide)‐grafted‐polyethersulfone (PEO‐g‐PES) in different compositions have been prepared and studied in terms of fuel cell relevant parameters like thermal behaviour, water uptake and ionic conductivity. Moreover, spectroscopic characterization (FT‐IR) has also been conducted in order to elucidate their miscibility and to investigate the influence of polymer blending on the crystallinity level of the individual components. These blends exhibit very good mechanical properties, a very high water uptake and a high ionic conductivity (4 × 10−3 S/cm) at ambient temperatures and they are amorphous, a property that facilitates their use as polymer electrolytes in fuel cells.
FT‐IR Spectroscopy and Hydrogen Bonding Interactions in Poly(styrene‐co‐methacrylic acid)/Poly(styrene‐co‐4‐vinyl pyridine) Blends
Authors: ElMiloudi Khaled , Benygzer Mourad , Djadoun Said , Sbirrazzuoli Nicolas , Geribaldi Serge
Published: December 2005

This contribution reports on a FT‐IR study of the hydrogen bonding interactions within blends of different ratios of poly(styrene‐co‐methacrylic acid) containing 15 mol% of methacrylic acid PSMA‐15 and poly(styrene‐co‐4‐vinylpyridine) containing 15 mol% of 4‐vinylpyridine PS4VP‐15. Equilibrium constants describing both the self‐association K2 and inter‐association KA in the (75:25) blend of poly‐ (styrene‐co‐methacrylic acid) containing 12 mol% of methacrylic acid PSMA‐12 with poly(styrene‐co‐4‐vinylpyridine) containing 22 mol% of 4‐vinylpyridine PS4VP‐22 were experimentally determined using a curve fitting analysis of the infra‐red spectra. The FT‐IR study at various temperatures confirms the miscibility of this blend up to 175 °C.
Infrared Monitoring of the Modification of Styrene Acrylonitrile Copolymers with Oxazoline and Its Interfacial Reaction with Acid‐Containing Polymers
Authors: Li Juan , Prusty Manoranjan , Goossens Han , van Duin Martin , de Wit Gert
Published: December 2005

The kinetics of the modification of styrene acrylonitrile (SAN) with aminoethanol to oxazoline‐containing copolymers has been monitored with FTIR spectroscopy. Further, the interfacial reaction in bilayer samples of the oxazoline groups of these copolymers and the carboxylic acid groups of poly(ethylene‐co‐methacrylic acid) (PE‐co‐MA) copolymers has been studied by FTIR at different temperatures. The interfacial formation of ester‐amides has been measured quantitatively by FTIR difference spectroscopy.
SERS Investigation on the Polymerization of Carbazolyl‐diacetylene Monolayers on Gold Surfaces
Authors: Muniz‐Miranda Maurizio , Giorgetti Emilia , Margheri Giancarlo , Del Rosso Tommaso , Sottini Stefano , Giusti Anna , Alloisio Marina
Published: December 2005

Surface Enhanced Raman Scattering experiments were performed on self‐assembled carbazolyl‐diacetylene monolayers chemisorbed on smooth gold substrates and UV irradiated. The Raman enhancement was ensured by depositing silver colloidal nanoparticles, which strongly increase the surface roughness. The co‐existence of two polymer phases, characterized by different degree of order in the polymeric backbone, was detected by SERS results, which suggest a polymerization scheme with conjugated triple bonds nearly parallel to the plane of the metal surface.
Acidity of Alginate Aerogels Studied by FTIR Spectroscopy of Probe Molecules
Authors: Valentin Romain , Horga Raluca , Bonelli Barbara , Garrone Edoardo , Di Renzo Francesco , Quignard Françoise
Published: December 2005

Supercritical drying of alginate gels is an efficient way to prepare aerogels with high surface area (>300 m2 · g−1). FTIR spectroscopy allows to monitor the adsorption of NH3 from the gas phase onto the acid sites of the alginate. Free carboxylic groups are effective Brønsted sites, whereas the divalent cations used in the ionotropic gelation present the properties of Lewis sites. The ratio between Brønsted and Lewis sites provides infomation on the role of pH in alginate gelation and suggests that non‐buffered gelation by transition‐metal cations is a mixed ionotropic‐acid process.
Characterization of Zr Phosphate/PVDF Nanocomposites by Vibrational Spectroscopy
Authors: Casciola Mario , Donnadio Anna , Pica Monica , Valentini Valeria , Piaggio Paolo
Published: December 2005

A study of the vibrational spectra obtained by various spectroscopic techniques (FTIR: T, ATR, PAS; FT‐Raman) was performed on nanocomposites of α‐zirconium phosphate [α‐ZrP] in poly(vinylidenefluoride) [PVDF] matrices of different morphology and composition. As the morphology of both dense and porous nanocomposite materials was carefully observed by electron microscopy (SEM, TEM and EDS), the vibrational spectra could be discussed in order to highlight the effectiveness of each spectroscopic technique for the characterization of this type of samples. Some results are presented showing that, by using the proper technique for each type of material, vibrational spectroscopy is very useful not only to determine composition and homogeneity of the nanocomposite but also to understand more specific points like the chain conformation of the polymer matrix and its interaction with the inorganic particles.
Experimental Testing of Lateral and Depth Resolution in Imaging Methods
Authors: Wilhelm Peter , Chernev Boril , Pölt Peter
Published: December 2005

A polymer laminate and a PA‐PTFE blend were studied by various imaging methods (FT‐IR, Raman, ESEM). Different lateral and depth resolution of the methods were used to gain complementary information on the structure of the materials. Radiation damage caused by the electron beam during ESEM investigation was studied by Raman global imaging.
Optical Absorption and Photo‐Luminescence Spectra of Molecular van der Waals Systems: Frenkel Exciton Resonance Effects
Authors: Fleming Alexander J. , Coleman Jonathan N. , Blau Werner J.
Published: December 2005

Applying the principle of conservation of energy, the photo‐absorption‐luminescence (p‐a‐l) cycle of resonant Frenkel excitons in aggregates is explained in terms of the p‐a‐l cycles of isolated molecules. The method employed to measure the Stokes shift of Frenkel Exciton Resonance (FER) systems, derived from our model, is found to differ significantly from that employed currently. Our postulate, that the aggregate v‐e transition energy, in the frame of reference of a resonant exciton, decreases as function of the localisation length of the exciton, is demonstrated by the excellent agreement of the model with existing data. This has allowed the determination of the localisation length of resonant excitons from readily available spectra. As the localisation length is a good indicator of the order of a system, this result will be useful in molecular self‐assembly (MSA) research. Results from the model suggest that Frenkel exciton resonance is vibrationally modulated, and the collective exciton eigenstate of a resonant Frenkel exciton can couple the v‐e manifolds of 2Nmolecules together via the electronic resonance interaction, even in the absence of direct intermolecular vibrational coupling. In essence, we demonstrate that the photo‐physics of an exciton that is resonant over many molecules is fundamentally determined by the photo‐physics of the isolated molecule just as one would expect.
Novel Biodegradable Poly(pentadecalactone‐co‐oxo‐crown ether) Studied with Solid‐State 1H and 13C NMR
Authors: Magusin Pieter C.M.M. , Mezari Brahim , van der Mee Lars , Palmans Anja R.A. , Meijer E.W.
Published: December 2005

Two grades of a novel biodegradable copolymer of ω‐pentadecalactone (PDL) and 2‐oxo‐12‐crown‐4 (OC), with respective molar compositions of 77/23 and 52/48, were characterized with 1D and 2D MAS 1H and 13C NMR spectroscopy. The results indicate that both copolymers are semi‐crystalline with PDL divided over the crystalline and amorphous phase, and OC exclusively located in the amorphous phase. Proton T2 and T1ρ relaxation confirm the existence of small crystalline domains.
Characterization of Thin Polymer Films on the Nanometer Scale with Confocal Raman AFM
Authors: Schmidt U. , Hild S. , Ibach W. , Hollricher O.
Published: December 2005

The combination of an atomic force microscope (AFM) with a Confocal Raman Microscope (CRM) has been used to study the composition of various thin films of polymer blends. The high spatial resolution of the AFM enables the morphological characterization of the polymer blends on the nanometer scale. Furthermore, when operating the AFM in Digital Pulsed Force Mode (DPFM), topographic information and local stiffness can be simultaneously recorded. This allows the material‐sensitive characterization of heterogeneous materials. Thin films where PMMA (at room temperature a glassy polymer) is blended with two different styrene‐butadiene rubbers are investigated. The presence of PMMA in both phase‐separated thin films allows the comparison of the mechanical properties of the two different rubber phases using DPFM‐AFM. When PMMA is blended with PET due to their similar mechanical properties (both are in the glassy state at room temperature) the assignment of the two phases to the corresponding polymers by AFM is rather difficult. Here, Raman spectroscopy provides additional information on the chemical composition of materials. In combination with a confocal microscope, the spatial distribution of the various phases can be determined with a resolution down to 200 nm. Therefore, the topographically different structures observed in AFM images can be associated to the chemical composition by using the Confocal Raman Microscope (CRM).
Network Density and Diene Conversion in Peroxide‐Cured Gumstock EPDM Rubbers. A Solid‐State NMR Study
Authors: Orza Ramona A. , Magusin Pieter C.M.M. , Litvinov Victor M. , van Duin Martin , Michels M.A.J.
Published: December 2005

Peroxide‐cross‐linked EPM and EPDM rubbers have been investigated with magic‐angle spinning 1H NMR spectroscopy and static 1H NMR relaxometry. The results yield a consistent nanoscale picture of the chemical and physical network properties in terms of chemical cross‐links formed via macro‐radical combination, chemical cross‐links formed via addition to the double bonds, and physical cross‐links resulting from chain entanglements.
Compositional Mapping of Polymer Surfaces by Chemical Force Microscopy Down to the Nanometer Scale: Reactions in Block Copolymer Microdomains
Authors: Schönherr Holger , Feng Chuan Liang , Tomczak Nikodem , Vancso G. Julius
Published: December 2005

The laterally resolved analysis of the chemical surface composition of surface‐treated block copolymers by atomic force microscopy (AFM) pull‐off force mapping in the force volume (FV) mode and the automated analysis of the FV data is discussed. Poly(tert‐butyl acrylate) (PtBA) microdomains residing in a polystyrene (PS) matrix at the surface of cyclohexane‐treated polystyrene‐block‐poly(tert‐butyl acrylate) (PtBA‐b‐PS) block copolymer thin films were domain‐selectively deprotected, activated and chemically modified, as also shown by fluorescence microscopy. AFM pull‐off force mapping in conjunction with an automated analysis of the data provided real space evidence for the successful conversion of reactive esters located in the PtBA domains and showed that AFM and related approaches, such as chemical force microscopy (CFM), can indeed contribute to assess changes in heterogeneous surface chemical composition of polymers down to sub‐50 nm length scales.
Infrared Spectroscopy and X‐Ray Diffraction Studies of CH…O Hydrogen Bonding and Thermal Behavior of Biodegradable Poly(hydroxyalkanoate)
Authors: Sato Harumi , Murakami Rumi , Zhang Jianming , Mori Katsuhito , Takahashi Isao , Terauchi Hikaru , Noda Isao , Ozaki Yukihiro
Published: December 2005

Infrared (IR) spectra and wide‐angle X‐ray diffraction (WAXD) patterns of poly(3‐hydroxybutyrate) (PHB) and its copolyester, poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate), P(HB‐co‐HHx) (HHx = 12 mol%) were measured over a temperature range of 20 °C to higher temperatures (PHB, 185 °C, HHx = 12 mol%, 140 °C) to explore their structure change and thermal behavior and molecular interaction. The WAXD measurements revealed that the a lattice parameter increases significantly with temperature, while the b lattice parameter varies a little in the crystalline PHB and P(HB‐co‐HHx). It seems that the intermolecular interaction between the CO group of one helical structure and the CH3 group of the other helical structure decreases along the a axis of crystalline PHB and P(HB‐co‐HHx) with temperature. The temperature‐dependent IR spectral variations were analyzed for the CH stretching, CO stretching, CH3 deformation, and COC stretching variation regions, and bands characteristic of crystalline and amorphous parts were identified in each region. It was found from the anomalous frequencies of the CH3 asymmetric stretching and CO stretching bands of PHB and P(HB‐co‐HHx) and the X‐ray crystallographic structure of PHB that there is an intermolecular interaction (CH…OC hydrogen bond) between the CO group and the CH3 group combining two helical structures in PHB and P(HB‐co‐HHx). In this review paper we discuss the role of the CH…OC hydrogen bonding and the crystal and lamella structure of PHB and P(HB‐co‐HHx) (HHx = 12 mol %) in comparison with the structure of Nylon.