bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermodynamic perspectives on the molecular mechanisms providing protein adsorption resistance that include protein‐surface interactions
Authors: Latour Robert A. 
Published: July 2006

AbstractCurrent theories regarding the molecular mechanisms that provide protein adsorption resistance primarily focus on the characteristics of various types of surface‐tethered chains and their interactions with water but often neglect their interactions with the protein. Such theories thus do not provide a complete explanation for protein adsorption resistance. The real issue that must be addressed is which properties enable surfaces to interact with water more favorably than with proteins. To address this issue, a thermodynamic treatment of protein adsorption to surface‐tethered chains is presented and specific molecular‐level interactions are addressed that contribute to enthalpy, entropy, and free energy changes that are involved during protein adsorption processes. Based on this analysis, it is proposed that two independently controllable sets of criteria provide conditions that are thermodynamically favorable for protein adsorption resistance: (1) well‐hydrated long flexible surface‐tethered chains with packing density sufficiently low to allow chain mobility while still providing complete surface coverage, and (2) surface‐tethered chains that contain hydrogen‐bondable groups that are readily accessible to water molecules but not to the hydrogen bond‐forming groups of a protein. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Construction of antibacterial multilayer films containing nanosilver via layer‐by‐layer assembly of heparin and chitosan‐silver ions complex
Authors: Fu Jinhong , Ji Jian , Fan Dezeng , Shen Jiacong 
Published: July 2006

AbstractAntibacterial multilayer films containing nanosilver were prepared via layer‐by‐layer fashion. PET film was aminolyzed with 1,6‐hexanediamine to introduce amino groups on PET film surface; chitosan–silver nitrate complex and heparin were alternately deposited onto an aminolyzed PET film surface, and subsequently, the silver ions within the multilayer films were reduced with ascorbic acid to form silver nanoparticles. UV–visible spectroscopy and transmission electron microscopy confirmed the formation of well‐dispersed nanosilver particles with sizes (10–40 nm) that depended on the initial concentration of silver ions in chitosan solution and the pH of ascorbic acid solution. The chitosan/heparin multilayer films were possessed of bactericidal effect on Escherichia coli (E. coli), and this antibacterial effect could be significantly enhanced by the incorporation of silver nanoparticles into the multilayer films. The multilayer films containing nanosilver were not only effective as antibacterial but also as anticoagulant coating. And cell toxicity evaluation suggested that the multilayer films containing nanosilver did not show any cytotoxicity. The multilayer films containing nanosilver may have good potentials for surface modification of medical devices, especially for cardiovascular implants. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Periodontitis destructions are restored by synthetic glycosaminoglycan mimetic
Authors: Lallam‐Laroye C. , Escartin Q. , Zlowodzki A.‐S. , Barritault D. , Caruelle J.‐P. , Baroukh B. , Saffar J.‐L. , Colombier M.‐L. 
Published: July 2006

AbstractPeriodontitis are bacterium‐driven inflammatory diseases that destroy tooth‐supporting tissues whose complete restoration is not currently possible. RGTA®, a new class of agents, have this capacity in an animal model. Periodontitis was induced in hamsters and, starting 8 weeks later, injected RG1503, a glycosaminoglycan synthesized from a 40 kDa dextran behaving like a heparan sulfate mimetic (1.5 mg kg−1 w−1) or saline for 8 weeks. The three periodontium compartments were evaluated by immunohistochemistry and morphometry. The gingival extracellular matrix disorganized by inflammation was restoring under treatment. The collagen network was repaired and resumed its previous organization. Fibrillin‐1 expression was restored so that the elastic network rebuilt at a distance from the pocket and began to reconstruct near the pocket. Apoptotic cell numbers were decreased in the pocket epithelium, and more so in the infiltrated connective tissue. The continuity and the thickness of the basement membrane were restored and testified normalization of epithelium connective tissue interaction. The amount of alveolar bone increased around the first molar, and the interradicular bone was rebuilt. The root cementum was thickened and the number of proliferating cells in the periodontal ligament was increased close to the cementum. RG1503 treatment induces potent anabolic reactions in the extracellular matrices of the different tissues of the periodontium and recruitment of progenitors. In particular, the cell proliferation close to the root surface suggests the reformation of a functional attachment apparatus. These results demonstrate that RG1503 reverses the degenerative changes induced by inflammation and favors the conditions of a regenerative process. Thus, RGTA, a known matrix component mimetic and protector, may be considered as a new therapeutic tool to regenerate the tissues destroyed by periodontitis. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Ozonation of weathered olive mill wastewaters
Authors: Karageorgos Petros , Coz Alberto , Charalabaki Magdalini , Kalogerakis Nicolas , Xekoukoulotakis Nikolaos P , Mantzavinos Dionissios 
Published: July 2006

AbstractThe treatment of fully and partly weathered olive mill wastewaters by means of ozonation was investigated, with emphasis on the effect of treatment conditions (organic loading, treatment time, ozone concentration) on the extent of chemical oxygen demand (COD) and total phenol degradation, colour removal as well as ecotoxicity to the marine bacterium Vibrio fischeri. In general, ozonation was capable of substantially reducing the concentration of phenols as well as decolourising the effluent after relatively short treatment times, with the extent of phenol and colour removal exceeding 80% in most cases. The fast and selective degradation of phenols was ascribed to the direct electrophilic attack by molecular ozone (ozonolysis). Conversely, complete mineralisation proved difficult; at the conditions employed in this study, COD removal varied from as little as 10% to about 60%. Both effluents were strongly ecotoxic owing to the presence of phenols and other organics in substantial concentrations; toxicity decreased partly following considerable degradation of the organic matter. Copyright © 2006 Society of Chemical Industry
Anaerobic biodegradability of gallic acid found in olive mill wastewaters
Authors: Kouroutzidou Eleni , Georgaki Irini , Mantzavinos Dionissios , Manios Thrassyvoulos 
Published: July 2006

AbstractThis paper discusses the applicability of a low‐cost method for evaluating the ability of anaerobic micro‐organisms to decompose phenolic compounds found in olive mill wastewaters. Gallic acid (GA) was used as test substance at concentrations of 100, 500 and 1000 mg L−1. When 1000 mg L−1 GA was inoculated with anaerobic sludge, the average (of six replicates) cumulative gas volume collected over a period of 23 days was 87.6 ± 2.4 mL, while without sludge the volume was 9.3 ± 1.0 mL. The corresponding values for 500 mg L−1 GA were 48.0 ± 8.0 and 6.5 ± 1.0 mL respectively, while for 100 mg L−1 GA they were 30.8 ± 4.7 and 9.6 ± 2.3 mL respectively. These results suggest that gallic acid is readily degradable under anaerobic conditions even at concentrations as high as 1000 mg L−1 if adequate fermentation time and appropriate microbial culture are provided. The gas volume produced was found to depend linearly (r2 = 0.95) on the concentration of gallic acid under the conditions studied. Copyright © 2006 Society of Chemical Industry
Enhanced anaerobic bioremediation of chlorinated solvents: environmental factors influencing microbial activity and their relevance under field conditions
Authors: Aulenta Federico , Majone Mauro , Tandoi Valter 
Published: July 2006

AbstractEnhanced in situ anaerobic bioremediation of chlorinated solvents is a cost‐effective, expanding technology for the clean‐up of chlorinated solvent‐contaminated sites. However, this technology is knowledge‐intensive and its application requires a thorough understanding of the microbiology, ecology, hydrology and geochemistry of chlorinated solvent‐contaminated aquifers. This review summarises current knowledge and future perspectives in the area of microbial anaerobic dechlorination of chlorinated solvents, particularly chloroethenes. Main attention is paid to the discussion of environmental factors and conditions that influence microbial activity under field conditions. Approaches to stimulate and manipulate the activity of native dechlorinating populations in order to meet target remediation goals for both plume management and source treatment are reviewed in detail. Possible research efforts needed to increase the likelihood of success of this technology are finally presented. Copyright © 2006 Society of Chemical Industry
Characterisation of a series of acetals/ketals of bis(2‐nitrophenyl) ethanediol and bis(4,5‐dimethoxy‐2‐nitrophenyl) ethanediol under APCI mass spectrometric conditions
Authors: Bhaskar G. , Prabhakar S. , Ravi Kumar M. , Narsimhaji Ch. V. , Srinivas K. , Vairamani M. 
Published: July 2006

AbstractA series acetals/ketals of aldehydes and ketones formed by the reaction of two photolabile protecting groups, bis(2‐nitrophenyl) ethanediol and bis(4,5‐dimethoxy‐2‐nitrophenyl) ethanediol (I and II, respectively), were analysed under EI, LSIMS, ESI and APCI conditions to obtain molecular weights as well as structural information. The EI and LSIMS techniques failed to give molecular weight information. The positive ESI yielded [M + H]+ ions only for I; however, with added Na+ both I and II formed [M + Na]+ adducts. But upon decomposition, the [M + Na]+ ions yielded Na+ ion as the only product ion. Similarly, under negative ion ESI conditions both I and II gave molecular weight information by forming adduct ions with halide anions (F−, Cl−, Br− and I−); however, they did not give structural information as they resulted in only the halide anion as the abundant fragment ion upon dissociation. All the compounds formed abundant M−• ions under negative ion APCI conditions, and their MS/MS spectra showed characteristic fragment ions; hence the acetals/ketals of I and II could be successfully characterized under negative ion APCI conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Behaviour of family 10 and 11 xylanases towards arabinoxylans with varying structure
Authors: Bonnin Estelle , Daviet Stéphanie , Sorensen Jens F , Sibbesen Ole , Goldson Andrew , Juge Nathalie , Saulnier Luc 
Published: July 2006

AbstractThe effect of arabinoxylan structure on xylanase activity was investigated using a range of water‐soluble and water‐insoluble substrates isolated from wheat flour and several xylanases from families 10 and 11 of the glycoside hydrolases. The arabinose content of the substrates affected the activity in a linear manner related to the arabinose:xylose ratio and to different extents depending on the specificity of the xylanase. The soluble/insoluble feature of the substrates had a strong impact on the enzymatic activity and different selectivities (activity on insoluble arabinoxylan vs. activity on soluble arabinoxylan) were observed. There was no relationship between specificity and selectivity of a given xylanase. Copyright © 2006 Society of Chemical Industry
Influence of amylases on the rheological and molecular properties of partially damaged wheat starch
Authors: Leman Pedro , Bijttebier Annabel , Goesaert Hans , Vandeputte Greet E , Delcour Jan A 
Published: July 2006

AbstractThe effects of Bacillus subtilis, porcine pancreatic and Aspergillus oryzae α‐amylases, sweet potato β‐amylase and Bacillus stearothermophilus maltogenic amylase (BStA) on the rheological properties (measured with a Rapid Visco Analyser) of partially damaged wheat starch were studied and the accompanying changes in starch molecular properties were analysed by high‐performance size exclusion chromatography. Pasting and gelation of starch slurries (with an increased level of damaged starch) were significantly affected by the supplemented amylases and greatly depended on the mode of action and properties of the enzymes added. In general, at low endo‐amylase concentrations, peak, hot paste and cold paste viscosities were more reduced for enzyme‐supplemented partially damaged starch than for enzyme‐supplemented native wheat starch, demonstrating the significance of damaged starch levels in determining amylase functionality. Higher dosages of thermostable amylases ruled out most of the differences between amylase‐supplemented native starch and partially damaged starches, except for BStA. Furthermore, the (limited) endo‐action of BStA determines to a great extent the rheological properties of the starch paste. These results contribute to a better understanding of (maltogenic) amylase functionality in processing (damaged) starch‐containing foods. Copyright © 2006 Society of Chemical Industry
Gas‐phase reaction of hydroxyl radicals withm‐,o‐ andp‐cresol
Authors: Coeur‐Tourneur Cecile , Henry Françoise , Janquin Marie‐Andrée , Brutier Laurent 
Published: July 2006

AbstractThe gas‐phase reaction of oxygenated aromatic compoundsm‐cresol,o‐cresol, andp‐cresol with hydroxyl radicals has been studied by GC‐MS. Experiments have been performed in a large‐volume photoreactor (8000 L) at 294 ± 2 K and atmospheric pressure. The relative kinetic method was used to determine the rate constants for these reactions, with 1,3,5‐trimethylbenzene as a reference compound. The rate constants obtained arekOH(m‐cresol) = (5.88 ± 0.92) × 10−11cm3molecule−1s−1,kOH(o‐cresol) = (4.32 ± 0.52) × 10−11cm3molecule−1s−1, andkOH(p‐cresol) = (4.96 ± 0.75) × 10−11cm3molecule−1s−1. The degradation products observed and their respective molar yields were methyl‐1,4‐benzoquinone 12.4 ± 1.2%, 5‐methyl‐2‐nitrophenol 1.5 ± 0.3%, and 3‐methyl‐2‐nitrophenol 1.4 ± 0.3% fromm‐cresol, methyl‐1,4‐benzoquinone 5.6 ± 0.9%, and 6‐methyl‐2‐nitrophenol 4.7 ± 0.8% fromo‐cresol, and 4‐methyl‐2‐nitrophenol 17.2 ± 2.5% fromp‐cresol. This kinetic and product data are compared with the literature, and the reaction mechanisms are discussed. Our results are in accordance with the previous studies (Atkinson,J Phys Chem Ref Data1989, Monograph (1), 1–246; Atkinson and Aschmann,Int J Chem Kinet1990, 22, 59–67; Atkinson et al.,Environ Sci Technol1992, 26, 1397–1403; Atkinson et al.,J Phys Chem1978, 82, 2759–2805; Olariu et al.,Atmos Environ2002, 36, 3685–3697; Semadeni et al.,Int J Chem Kinet1995, 27, 287–304) and confirm the methyl‐1,4‐benzoquinone yields determined by a different experimental technique (long‐path Fourier transform infrared FT‐IR (Olariu et al., 2002)). © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 553–562, 2006
Reaction of the NO3 radical with some thiophenes: Kinetic study and a correlation between rate constant and EHOMO
Authors: Cabañas B. , Baeza M.T. , Martín P. , Salgado S. , Villanueva F. , Monedero E. , Díaz De Mera Y. 
Published: July 2006

AbstractThe rate constants and activation energies for the reactions of some thiophenes with the NO3 radical were measured using the absolute fast‐flow discharge technique at 263–335 K and low pressure. The proposed Arrhenius expressions for 2‐ethylthiophene, 2‐propylthiophene, 2,5‐dimethylthiophene, and 2‐chlorothiophene are k = (4.2 ± 0.28) ×10−16 exp[(2280 ± 70)]/T, k = (7.0 ± 2) × 10−18 exp[(3530 ± 70)]/T, k = (1 ± 1) × 10−14 exp[(1648 ± 240)]/T, and k = (8 ± 2) × 10−17 exp[(2000 ± 200)]/T (k = cm3 molecule−1 s−1), respectively. The reactions of this radical with 2‐chlorothiophene and 3‐chlorothiophene were also studied by a relative method in a Teflon static reactor at room temperature and atmospheric pressure. The effect of substitution on thiophene reactivity is discussed, and a relationship between the rate constants and the ionization potential (IP = −EHOMO) has been proposed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 570–576, 2006
Rate coefficients for the gas‐phase reaction of hydroxyl radicals with the dimethylbenzaldehydes
Authors: Clifford Grainne M. , Wenger John C. 
Published: July 2006

AbstractRate coefficients for the reactions of hydroxyl (OH) radicals with the dimethylbenzaldehydes have been determined at 295 ± 2K and atmospheric pressure using the relative rate technique. Experiments were performed in an atmospheric simulation chamber using gas chromatography for chemical analysis. The rate coefficients (in units of cm3molecule−1s−1) are: 2,3‐dimethylbenzaldehyde, (25.9 ± 2.8) × 10−12; 2,4‐dimethylbenzaldehyde, (27.5 ± 4.4) × 10−12; 2,5‐dimethylbenzaldehyde, (27.6 ± 5.1) × 10−12; 2,6‐dimethylbenzaldehyde, (30.7 ± 3.0) × 10−12; 3,4‐dimethylbenzaldehyde, (24.6 ± 4.0) × 10−12; and 3,5‐dimethylbenzaldehyde, (28.2 ± 2.5) × 10−12. The reactivity of the dimethylbenzaldehydes is compared with other aromatic compounds and it is shown that the magnitude of the OH rate coefficients does not depend significantly on the position of the CH3substituent on the aromatic ring. The rate coefficient data are explained in terms of known mechanistic features of the reactions and the atmospheric implications are also discussed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 563–569, 2006
Biobased Contents of Biodegradable Poly(ε‐caprolactone) Composites Polymerized and Directly Molded Using Aluminium Triflate from Caprolactone with Cellulose and Inorganic Filler
Authors: Kunioka Masao , Inuzuka Yoshifumi , Ninomiya Fumi , Funabashi Masahiro 
Published: July 2006

AbstractSummary: Poly(ε‐caprolactone) (PCL) composite samples were prepared by polymerization and direct molding. The starting compound was ε‐caprolactone monomer liquid combined with cellulose and inorganic fillers, using aluminium triflate as a catalyst at 80 °C, for 6 or 24 h. Cylinder‐shaped PCL composite samples with a homogeneously dispersed cellulose filler were prepared with $\overline M _{\rm n}$ = 4 600 ($\overline M _{\rm w} /\overline M _{\rm n}$ = 2.9). The mechanical properties of the PCL composite samples were studied using compression test methods. The strength of a PCL composite with 50 wt.‐% cellulose filler (10.8 MPa) was found to be lower than the PCL sample without fillers (19.2 MPa). The biobased content of the PCL composite with 50 wt.‐% cellulose filler (51.67%) measured using accelerated mass spectrometry (AMS) was slightly higher than the carbon ratio of cellulose in the starting powder samples (41.3 mol‐%). The biobased content of the polymer composite powders by AMS was found not to be affected by the presence of inorganic fillers, such as talc. The rate and extent of biodegradation, caused by Amano Lipase PS, of the PCL composite sample with cellulose filler (40% degradation in 4 d) was the same as that of a PCL sample without the cellulose filler.
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Synthesis and Hydrolysis Behaviour of Poly(ester anhydrides) from Polylactone Precursors Containing Alkenyl Moieties
Authors: Korhonen Harri , Hakala Risto A. , Helminen Antti O. , Seppälä Jukka V. 
Published: July 2006

AbstractSummary: Hydroxyl‐group functional polylactones were prepared and converted to acid‐ terminated polyesters in a reaction with a series of alkenylsuccinic anhydrides containing 8, 12, or 18 carbons in their alkenyl chains. These polyester precursors were then linked into higher molecular weight poly(ester anhydrides) containing alkenyl moieties in their polyester blocks. The hydrolysis behaviour of the poly(ester anhydrides) was found to depend on the thermal properties of the polyester precursors. For poly(ester anhydrides) prepared from low molecular weight prepolymers with thermal transitions below 37 °C, the presence of hydrophobic alkenyl chains in the polyester precursors slowed the rate of weight loss. Poly(ester anhydrides) prepared from higher molecular weight prepolymers showed the opposite weight‐loss behaviour; i.e., the crystallinity and thermal transitions of the alkenyl chain‐containing poly(ester anhydrides) were low, and the weight loss was faster than for poly(ester anhydrides) without the alkenyl chains. The differences in length of the alkenyl chain, as such, had little effect on the hydrolysis behaviour and thermal properties of the poly(ester anhydrides).Structure of poly(ester anhydride) molecules.magnified imageStructure of poly(ester anhydride) molecules.
Thermal Degradation of Environmentally Degradable Poly(hydroxyalkanoic acid)s
Authors: Abe Hideki 
Published: July 2006

AbstractSummary: Aliphatic polyesters have attracted industrial attention as environmentally degradable thermoplastics to be used for a wide range of applications. Besides intensive studies on the biodegradability of aliphatic polyesters, understanding of the thermal stability has importance for processing, application, and recycling. The details of thermal degradation processes of five types of aliphatic polyesters; namely, poly(L‐lactide), poly(3‐hydroxybutyric acid), poly(4‐hydroxybutyric acid), poly(δ‐valerolactone), and poly(ε‐caprolactone), were investigated by means of several thermoanalytical techniques under both isothermal and non‐isothermal conditions. In this feature article, the thermal degradation behaviors of aliphatic polyesters with different numbers of carbon atoms in the main chain of the monomeric unit are reviewed. In addition, the effects of chain‐end structure and residual metal compounds on the thermal degradation processes of aliphatic polyesters consisting of hydroxyalkanoic acid monomeric units are presented.Schemes of thermal degradation reaction of poly(hydroxyalkanoic acid)s.magnified imageSchemes of thermal degradation reaction of poly(hydroxyalkanoic acid)s.
Comparison study of autonomous activity in bladders from normal and paraplegic rats
Authors: Gevaert Thomas , Ost Dieter , De Ridder Dirk 
Published: July 2006

AbstractAimTo identify differences in the pattern of pressure generated by isolated bladders from normal and paraplegic rats.Materials and MethodsNine female Wister rats were made paraplegic by spinal cord transsection at the vertebral level T8‐T9 and sacrificed between D21 and D28. A further group (n = 9) was used as a control group. Each bladder was excised and placed in an organ bath where intravesical pressures were measured. Pressure changes were divided in two well‐defined groups: macro‐transients and spikes. The effects of intravesical volume load and muscarinic (M) agonists were studied.ResultsWe demonstrated a higher frequency, a longer duration, and a higher variance of duration in macro‐transients in the neurogenic group. Intravesical volume load influenced the amplitude and frequency of macro‐transients in both groups similarly. The effects of the muscarinic (M2)‐selective agonist arecaïdine were different in neurogenic bladder; the effects of the non‐selective muscarinic (M)‐agonist carbachol were similar in both groups.ConclusionWe showed that the pattern of autonomous activity was significantly different between normal and neurogenic rat bladders. We also found evidence for alterations in the muscarinic response of isolated neurogenic rat bladders. This model offers an exciting new research tool to evaluate the detrusor activity in neurogenic and normal conditions. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.