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Results 351 - 400 of 1409
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Benoit Danielle S W - - 2006
Hydrogels were prepared by copolymerizing a degradable macromer, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) endcapped with methacrylate groups (PEG-LA-DM), with a nondegradable macromer, poly(ethylene glycol) dimethacrylate (PEGDM). Copolymer networks consisted of 100:0, 83:17, 67:33, and 50:50 PEGDM:PEG-LA-DM mass%, essentially creating scaffolds that exhibit 0, 17, 33, and 50% degradation over the time ...
Yonezawa Tetsu - - 2006
Helical polypeptides have a highly rigid conformation. In order to control self-assembling structure in nanoscale, the rigidity of the stabilizing molecules, which is working as scaffolds, is highly important. Furthermore, the molecular lengths of polypeptides can be readily controlled by using their unique polymerization methods. In this study, we have ...
Ban Seiji - - 2006
Commercially pure titanium (cpTi) was etched using three concentrated acids: 18% HCl, 43% H3PO4, and 48% H2SO4. The bond strengths between five types of veneering composite resin and eight cpTi treatments (involving combinations of sandblasting, acid etching in 48% H2SO4, and vacuum firing) were determined before and after 10,000 and ...
Gerhardt Warren W - - 2006
Side-chain-functionalized lactide analogues have been synthesized from commercially available amino acids and polymerized using stannous octoate as a catalyst. The synthetic strategy presented allows for the incorporation of any protected amino acid for the preparation of functionalized diastereomerically pure lactide monomers. The resulting functionalized cyclic monomers can be homopolymerized and ...
Okuda Tatsuya - - 2006
In this study, we synthesized dendritic poly(L-lysine)s (DPKs), dendritic poly(L-ornithine)s (DPOs), which are constructed as novel amino acid dendrimers, and PEGylated KG6 (the sixth generation of DPKs), and evaluated the physicochemical properties and biodistribution characteristics of these dendrimers. The particle size of DPKs and DPOs was well controlled in the ...
Moffatt Stanley - - 2006
J591 monoclonal antibody (mAb) has high affinity for prostate specific membrane antigen (PSMA) on prostate cancer (PCA) cells. We coupled polyethylene glycol-J591 (PEGylated J591) to a salicyl hydroxamic acid (SHA)-derivatized polyethylenimine (PEI)/DNA-betagal vector to investigate the specificity and efficiency of targeting PSMA in PCA cells through encapsulation. Coupling was facilitated ...
Wiegand A - - 2007
OBJECTIVE: The study aimed to evaluate the erosive effects of acids flowing with different velocities and duration on dentin previously pre-treated with distilled water or human saliva. METHODS: Bovine dentin surfaces were submitted to a 10 min demineralisation with hydrochloric or citric acid (pH 2.3, 37 degrees C) in an ...
Mazzoni Annalisa - - 2006
Auto-degradation of collagen matrices occurs in resin-infiltrated dentine by the slow action of host-derived matrix metalloproteinases. As phosphoric acid-etching inactivates these endogenous enzymes, it is puzzling how hybrid layers created by simplified etch-and-rinse adhesives can degrade in vivo. This study tested the null hypothesis that there are no differences in ...
Li Wan-Ju - - 2006
The most common synthetic biodegradable polymers being investigated for tissue engineering applications are FDA approved, clinically used poly(alpha-hydroxy esters). To better assess the applicability of the electrospinning technology for scaffold fabrication, six commonly used poly(alpha-hydroxy esters) were used to prepare electrospun fibrous scaffolds, and their physical and biological properties were ...
Maeda Hirotaka - - 2006
Poly(lactic acid) composite hollow spheres containing calcium carbonate were prepared by oil-in-water emulsion evaporation to develop injectable bone substitutes incorporated with cells. The spheres were approximately 1.2mm in diameter and had a shell with a thickness in the range of 50-150microm. The hollow in the spheres was presumed to be ...
Syu Mei-Jywan - - 2006
A molecularly imprinted polymer (MIP) capable of detecting bilirubin was successfully synthesized. Bilirubin template was imprinted in poly(methacrylic acid-co-ethylene glycol dimethylacrylate) [poly(MAA-co-EGDMA)]. MAA and EGDMA were used as the monomer and the cross-linker, respectively. The optimal solvent conditions to maintain its stability were discussed. Solvent system based on ethylenediamine tetraacetic ...
Sun Zhi - - 2006
The purpose of this study was to express, characterize, and investigate the self-assembly of a recombinant porcine amelogenin lacking the hydrophilic 24 C-terminal amino acids (rP148). To gain further insight into the function of amelogenin processing during enamel mineralization, this protein was also used as a substrate to examine the ...
Guelcher Scott A - - 2006
The development of therapeutics for orthopedic clinical indications exploiting minimally invasive surgical techniques has substantial benefits, especially for treatment of fragility fractures in the distal radius of osteoporotics and vertebral compression fractures. We have designed six formulations of injectable polyurethane foams to address these clinical indications. The polyurethanes were prepared ...
Cehreli Sevi Burcak - - 2006
PURPOSE: The objective of this study was to evaluate the ultramorphological changes after agitated and nonagitated application of self-etching primer systems on unground primary and permanent enamel. METHODS: Five self-etching primer systems were used: (1) Clearfil SE Bond; (2) Clearfil Protect Bond; (3) Adper Prompt; (4) Xeno III; and (5) ...
Keenan Thomas M - - 2006
The potential for the use of woody biomass in poly-beta-hydroxyalkanoate (PHA) biosynthesis is reviewed. Based on previously cited work indicating incorporation of xylose or levulinic acid (LA) into PHAs by several bacterial strains, we have initiated a study for exploring bioconversion of forest resources to technically relevant copolymers. Initially, PHA ...
Addison Owen - - 2007
OBJECTIVES: Hydrofluoric (HF) acid etching increases the bond strength between composite resin and porcelain surfaces and has been advocated as a pre-cementation technique for ceramic restorations. The internal surface flaw distribution which is implicated in the premature failure of ceramic restorations is modified by the etching process and little agreement ...
Peez R - - 2006
OBJECTIVES: To evaluate the time dependence of physical-mechanical performance of glass ionomer restoratives. METHODS: The physical-mechanical properties of Ketac Molar Easymix in comparison to four handmix glass ionomer restoratives were evaluated by testing the compressive and flexural strength, acid erosion and solubility. By testing the properties in the early and ...
Conconi Maria Teresa - - 2006
Polyphosphazenes with amino acid ester as side groups are biocompatible polymers that could provide valid scaffolds for cell growth. In the present study we investigate the adhesion and growth of osteoblasts obtained from rat bone marrow on matrices composed of thin fibers of poly[bis(ethyl alanato)phosphazene] (PAlaP), poly(d,l-lactic acid) (PDLLA), or ...
Pitarresi Giovanna - - 2006
The aim of this work has been the preparation and characterization of novel hydrogels with polysaccharide-poly(amino acid) structure having suitable physicochemical properties for pharmaceutical applications. In the first step, hyaluronic acid (HA) and alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) have been derivatized with methacrylic anhydride (AMA), thus obtaining HA-AMA and PHM derivatives, respectively. In ...
Culbertson B M - - 2006
The polymeric materials currently used in GIC are based on poly(acrylic acid), poly(acrylic acid-co-itaconic acid), or poly(acrylic acid-co-maleic acid). For the visible light cured (VLC) type GIC, the polymeric material is chemically modified to have pendant free-radical polymerizable double bonds, with the aqueous formulation solution also containing a monomer having ...
Rodrigues Paula C A - - 2006
Polyethylene glycol conjugates with linkers of varying acid-sensitivity were prepared by reacting five maleimide derivatives of daunorubicin containing an amide bond (1) or acid-sensitive carboxylic hydrazone bonds (2-5) with alpha-methoxy-poly(ethylene glycol)-thiopropionic acid amide (MW 20000) or alpha,omega-bis-thiopropionic acid amide poly(ethylene glycol) (MW 20000). The polymer drug derivatives were designed to ...
Karal-Yilmaz Ok┼čan - - 2006
Multiblock terpolymer of poly(L-lactic acid)/poly(ethylene oxide)/poly(L-aspartic acid), (PLLA/PEO/PAsp) was synthesized by ring opening polymerization of beta -benzyl L-aspartate N-carboxyanhydride, Asp(OBzl)-NCA with alpha-omega -hydroxy terminated triblock PLLA/PEO/PLLA copolymer. The resulting multiblock terpolymer was characterized by several techniques including Fourier transform infrared spectroscopy and differential scanning calorimetry.(1)H nuclear magnetic resonance spectra indicated ...
Whitaker-Brothers Kenya - - 2006
Salicylate-based poly(anhydride-esters), collectively referred to as PolyAspirin, hydrolytically degrade into salicylic acid, a nonsteroidal anti-inflammatory drug (NSAID). The variations of the poly(anhydride-ester) investigated in this article are linked by adipic acid, suberic acid, or sebacic acid. To elucidate the erosion mechanism of these polymers, water uptake, mass loss, contact angle, ...
Solaiman Daniel K Y - - 2006
Pseudomonas corrugata was selected from a screening process for the bioconversion of inexpensive soy molasses into medium-chain-length poly(hydroxyalkanoates) (mcl-PHA). We obtained yields of 1.5 g cell dry weight (CDW)/l culture with growth medium supplemented with 2% (w/v) soy molasses, and of an average of 3.4 g CDW/l with 5% (w/v) ...
Le Moullec Sophie - - 2006
The analysis of alkyl alkylphosphonic acids, the degradation products of V and G nerve agents as VX, Sarin or Soman, is an important task for the verification of compliance to the Chemical Weapons Convention. The detection of these contaminants at low concentration levels is often difficult in complex matrices due ...
Vicente Ascensión - - 2006
The objective of this study was to evaluate the effectiveness of a self-etching primer, Transbond Plus Self Etching Primer (TSEP, 3M Unitek), and a non-rinse conditioner (NRC, Dentsply DeTrey) for bonding brackets, compared with the acid-etch technique. The brackets were bonded to extracted premolars using Transbond XT (3M Unitek). One ...
Lauw Y - - 2006
The micellization properties of carboxy-modified Pluronics P85 (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers) are investigated by means of a molecularly realistic self-consistent-field theory. We consider the, so-called, carboxylic acid end-standing P85 (CAE-85) case where the carboxylic group is located at the end of both PEO parts and the carboxylic ...
Flora Jason W - - 2006
With the extent of international usage and the critical role phosphine gas (PH3) plays in commercial pest control, identification of the residual components deposited during fumigation is mandatory. It has been postulated that these infrequent residues are primarily composed of phosphoric acid or reduced forms of phosphoric acid [hypophosphorous acid ...
Featherstone J D B - - 2006
The mineral in our teeth is composed of a calcium-deficient carbonated hydroxyapatite (Ca10-xNax(PO4)6-y(CO3)z(OH)2-uFu). These substitutions in the mineral crystal lattice, especially carbonate, renders tooth mineral more acid soluble than hydroxyapatite. During erosion by acid and/or chelators, these agents interact with the surface of the mineral crystals, but only after they ...
Dhanikula Renu Singh - - 2006
Novel polyester-co-polyether dendrimers consisting of a hydrophilic core were synthesized by a combination of convergent and divergent syntheses. The core was synthesized from biocompatible moieties, butanetetracarboxylic acid and aspartic acid, and the dendrons from PEO (poly(ethylene oxide)), dihydroxybenzoic acid or gallic acid, and PEG monomethacrylate. The dendrimers, Den-1-(G 2) (second ...
Otsuka Hidenori - - 2006
This study demonstrates that boronic acid-containing polymers coated onto solid support function as synthetic mitogens for mouse lymphocytes. The polymer was synthesized by radical copolymerization of 3-acrylamidophenylboronic acid with dimethylacrylamide (poly(AAPBA-DMAA)). The boronic acid in the trigonal form in the copolymer activated lymphocytes, probably by crosslinkage to glycoprotein moieties on ...
Xie Dong - - 2006
A novel photo-cured amino-acid-constructed glass-ionomer cement system has been developed. Glutamic acid- and beta-alanine-based methacrylate and acrylate derivatives were synthesized, characterized and used to construct the polyalkenoic acids and formulated with water and Fuji II glass filler to form self-cured cement. Compressive strength (CS) of the cement and viscosity of ...
Wiegand A - - 2006
This study aimed to evaluate the susceptibility of eroded enamel to brushing abrasion performed by manual, power or sonic toothbrushes. Bovine enamel samples were subjected to 5 cycles, each consisting of 5 min demineralisation, 15 min remineralisation and 10 min brushing in a machine. Toothbrushing with the activated electric devices ...
Saueia C H R - - 2006
The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dehydrated calcium sulphate (phosphogypsum) as by-products. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). ...
Soares Luís Eduardo Silva - - 2006
The aim of this study was to evaluate by dispersive Raman spectroscopy the mineral and organic components of human dentin before and after laser irradiation and acid etching. The occlusal enamel of six non-carious human third molars was removed providing 6 dentin discs, which were divided in four quadrants each ...
Yu Guanhua - - 2006
The poly(D,L-lactic acid)-block-(ligand-tethered poly(ethylene glycol)) copolymer was explored to engineer poly(D,L-lactic acid) (PLA) material to promote chondrocyte attachment and growth. The poly(D,L-lactic acid)-block-poly(ethylene glycol) copolymer (PLE) was synthesized by a coupling reaction between PLA and poly(ethylene glycol) (PEG) (M(n) 1000, 2000, and 4000 respectively), with the use of 4,4'-methylenediphenyl diisocyanate ...
Shikanov Ariella - - 2006
The investigated polymers, poly(sebacic acid-co-ricinoleic acid) containing > or =70% ricinoleic acid, may be injected via a 22 gauge needle and become gel upon contact with aqueous medium, both in vitro and in vivo. Various properties of the polymers including viscosity, thermal analysis, and in vivo behavior, before and after ...
Zero D T - - 2006
During and after an erosive challenge, behavioral factors play a role in modifying the extent of erosive tooth wear. The manner that dietary acids are introduced into the mouth (gulping, sipping, use of a straw) will affect how long the teeth are in contact with the erosive challenge. The frequency ...
Ito Azusa - - 2006
The effects of lysine (Lys), monosodium glutamate (GluNa), glycine, alanine and epsilon-poly(L-lysine) (PL) with different degrees of polymerization on the gelatinization behavior of potato starch granules were investigated by DSC, viscosity and swelling measurements, microscopic observation, and measurement of the retained amino acid amount to clarify the contribution of the ...
Chen David C - - 2006
INTRODUCTION: Biodegradable polyester scaffolds have proven useful for growing neointestinal tissue equivalents both in vitro and in vivo. These scaffolds allow cells to attach and grow in a 3-dimensional space while nutrient flow is maintained throughout the matrix. The purpose of this study was to evaluate different biopolymer constructs and ...
Fowler Christabel - - 2006
OBJECTIVE: To evaluate in vitro the efficacy of a new anti-erosion desensitizing toothpaste to inhibit enamel surface softening by a dietary acid, and promote re-hardening of artificial erosive lesions. METHODOLOGY: The ability of the toothpaste to inhibit formation and promote repair of erosive lesions in human enamel has been investigated. ...
Lennon A M - - 2006
The aim of this study was to determine whether a tooth cream containing casein/calcium phosphate (CasCP) protects enamel against erosion. Sixty bovine enamel specimens were prepared for profilometry and distributed into five groups. Specimens were rinsed with artificial saliva interrupted by 1% citric acid (pH 2.3) for 30 s 6 ...
Pandis Nikolaos - - 2006
OBJECTIVES: Comparative assessment of the failure rate of molar tubes bonded to first and second molars with a self-etching primer and conventional acid-etching. MATERIAL AND METHODS: Four hundred forty-four molar tubes (246 first molar tubes and 198 second molar tubes) were bonded, using a split-mouth design, on 62 patients (23 ...
Hahn Sei Kwang - - 2005
A novel biocompatible polyelectrolyte complex multilayer (PECML) was successfully prepared using hyaluronic acid (HA) and poly-l-lysine (PLL). The formation of PECML through the electrostatic interaction of HA as a polyanion and PLL as a polycation was confirmed by contact angle measurement, ESCA analysis and HA content analysis. According to the ...
Ban Seiji - - 2006
OBJECTIVE: The purpose of this study was to characterize the etching behavior of titanium in concentrated sulfuric acid and discuss its application on surface modification of titanium for biological use. METHODS: Commercially pure titanium (cpTi) plate was etched in 48% H2SO4 at RT -90 degrees C for 0.25-8 h. The ...
Rees Jeremy - - 2005
Sports drinks are becoming increasingly popular as we are all being encouraged to adopt a healthier lifestyle with regular exercise. However, many of these products are based on acidic fruits and may contribute to erosion. The aim of this study was to screen a number of these products for their ...
Cirpanli Yasemin - - 2005
Poly (lactic-co-glycolic acid) (PLGA) microspheres containing all-trans retinoic acid (atRA) were prepared by emulsion/solvent evaporation technique. PLGA (50:50) with inherent viscosities of 0.17 and 0.39 dL g(-1) was used. Polyvinyl alcohol (PVA) or PVA and sodium oleate (SO) combinations (4:1) were used to stabilize the emulsions. The effect of polymer ...
Zhang Yongchao - - 2005
We describe a simple, potentially low-cost, amperometric, enzyme-amplified, sandwich-type immunoassay, monitoring IgG at a concentration as low as approximately 7 pg/mL with a dynamic range of 10(4). The assay utilizes a screen-printed carbon electrode on which a redox hydrogel and avidin are co-electrodeposited. To neutralize nonspecifically binding positively charged microdomains ...
Lilley K J - - 2005
Nanocrystalline hydroxyapatite (nHA) can be mixed with phosphoric acid to form a brushite cement; a degradable inorganic bone filling material. nHA was precipitated from reactants of calcium to phosphate (Ca/P) ratio 0.8 to 2.0 and mixed with phosphoric acid, which resulted in the formation of a brushite cement. Cement was ...
Abe Hajime - - 2005
A basic host polymer exhibiting pH-regulatable saccharide recognition has been investigated. Poly(m-ethynylpyridine) bearing dialkylamino groups forms helical complexes with saccharides to show induced circular dichroism (ICD). When trifluoroacetic acid was titrated on these complexes, the ICD was gradually enhanced until the amount of the acid reached ca. 0.5 molar equivalence ...
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