Search Results
Results 451 - 500 of 1423
< 5 6 7 8 9 10 11 12 13 14 15 >
Yang Seung Rim - - 2005
N(omega)-2,2,4,6,7-Pentamethyldihydrobenzofuran-5-sulfonyl (N(omega)-Pbf)-protected oligoarginine was directly conjugated to poly(amino acid) derivatives modified with a long alkyl chain. The final concentration of conjugated peptides was easily controlled by the feed ratio of oligoarginine to polymer backbone and a final soluble polymeric system was obtained by the deprotection of N(omega)-Pbf groups. The polymeric ...
Van Landuyt K L - - 2006
The self-etch approach provides dentists with a generation of user-friendly and less technique-sensitive adhesives. Nevertheless, some concern has been raised regarding their bonding effectiveness to enamel, in particular when so-called 'mild' self-etch adhesives are employed. OBJECTIVES: The purpose of this study was to test the hypothesis that the two-step self-etch ...
Murty Santos B - - 2005
Since acylated peptide impurities were isolated from octreotide microspheres following incubation in an in vivo environment, the present investigation was undertaken to determine the dosage form dynamics responsible for facilitating acylation. In particular, microsphere batches made with poly(L-lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) 85:15 were studied for in vitro drug release, ...
Malusà E - - 2005
The levels of phosphorous acid residues in apples after foliar fertilization with P fertilizers and after treatment with a phosphonate fungicide (Fosetyl-Al) were determined and compared. Two field trials and a glasshouse experiment, using different genotypes and plants of different age, were carried out and monitored over a three-year period. ...
Chen Hong - - 2005
Ultrafine cellulose fiber (diameter 200-400 nm) surfaces were grafted with polyacrylic acid (PAA) via either ceric ion initiated polymerization or methacrylation of cellulose with methacrylate chloride (MACl) and subsequent free-radical polymerization of acrylic acid. PAA grafts by ceric ion initiated polymerization increased with increasing reaction time (2-24 h), monomer (0.3-2.4 ...
Reddy Rajarathnam E - - 2005
An efficient method was developed for the preparation of polyanionic affinity agent (3), a key component in the measurement of glycated hemoglobin (GHb). Glycated hemoglobin is an important clinical marker for diagnosis of patients with diabetes and useful to monitor the management of disease. The affinity agent (3) was prepared ...
Caminear David S - - 2005
This study investigated the use of a bioabsorbable pin made of an oriented poly-L-lactic acid/polyglycolic acid (82:18 ratio) copolymer to fix distal chevron osteotomies in 15 patients (18 feet), with an average follow-up of 18 months. This material absorbs faster than poly-L-lactic acid and slower than poly-p-dioxanone, 2 bioabsorbable polymers ...
Nishiyama Norihiro - - 2005
It is well understood that the application of a self-etching primer enhances the bonding at the resin-teeth interface. In this study, we designed a self-etching primer consisting of N-methacryloyl glycine (NMGly) and N-methacryloyl-2-aminoethyl phosphonic acid (NMEP). The demineralization effects on the hydroxyapatite or dentin by the carboxylic acid in the ...
Ribeiro António J - - 2005
Alginate microspheres prepared by emulsification/internal gelation were chosen as carriers for a model protein, hemoglobin (Hb). Reinforced chitosan-coated microspheres were obtained by an uninterrupted method, in order to simplify the coating process, minimize protein losses during production and to avoid Hb escape under acidic conditions. Microspheres recovery was evaluated as ...
Imit Mokhtar - - 2005
Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated polymer, which can only be dissolved in strong acids such as formic acid) and allows mixing the protonated polymers with other chloroform soluble conjugated ...
Sasatsu Masanaho - - 2005
A novel poly(DL-lactic acid) (PLA) derivative with a diethoxy propanol ester at the end, named PLA-acetal, was synthesized by ring opening polymerization using DL-lactide and 3,3-diethoxy propanol. PLA-acetal was hydrolyzed to a PLA derivative with a formyl group, named PLA-aldehyde, by acid treatment. Reductive amination between PLA-aldehyde and methoxypolyethylene glycol ...
Fahmy Tarek M TM Department of Biomedical Engineering, Yale University, PO Box 208284, New Haven, CT 06520, USA. - - 2005
We describe a general method for incorporating target ligands into the surface of biocompatible polyester poly(lactic-co-glycolic acid) (PLGA) 50/50 materials using fatty acids. Avidin-fatty acid conjugates were prepared and efficiently incorporated into PLGA. Avidin was chosen as an adaptor protein to facilitate the attachment of a variety of biotinylated ligands. ...
Oehmen Adrian - - 2005
Poly-beta-hydroxyalkanoate (PHA) is a polymer commonly used in carbon and energy storage for many different bacterial cells. Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), store PHA anaerobically through metabolism of carbon substrates such as acetate and propionate. Although poly-beta-hydroxybutyrate (PHB) and poly-beta-hydroxyvalerate (PHV) are commonly quantified using a ...
Ayo-Yusuf Olalekan A - - 2005
OBJECTIVES: To evaluate the effects of gingival retraction fluids (GRF) on prepared dentine surfaces, and to test the null-hypothesis that prior exposure of dentine surfaces for prolonged period to any of the fluids evaluated does not influence acid-etching of the exposed surfaces. METHODS: The investigation was carried out using SEM ...
Foxton Richard M - - 2005
This study examined the effect of different acidic treatments and the role of a phosphate monomer in a silane coupling agent on the durability of the dual-cure resin cement/silicon oxide bond. Ceramic blocks (Vita Celay Blanks) were cut into multiple 3 mm-thick slices and polished using 600 grit SiC paper. ...
Chang W-G - - 2005
The purpose of this study was to evaluate the effects of salicylic-lactic (SL) acid conditioner on the shear bond strength of brackets. Fluoride releasing (Light-bond) and non-fluoride releasing (Enlight) composite adhesives were used after conditioning with 0.22% salicylic + 9% lactic acid or 34% phosphoric acid. Composite adhesives were light ...
Viyoch J - - 2005
Synopsis The aim of this study was to develop hydrogel patch using crosslinked chitosan-starch as polymeric matrix for controlling the release of the natural alpha-hydroxy acid (AHA) contained in the extract of tamarind's fruit pulp. The chitosan (MW 100 000) was blended with corn, tapioca or rice starch in various ...
Chen Yun - - 2005
Bonelike apatite coating was formed on poly(L-lactic acid) films and poly(glycolic acid) scaffolds within 24 h through an accelerated biomimetic process. The ion concentrations in the simulated body fluid (SBF) were nearly 5 times of those in the human blood plasma. The apatite formed was characterized by using scanning electron ...
Lee Sun Mi - - 2005
Polymers, containing 5-(4-O-methylacryloylbenzyl)thiazolidine-2,4-dione [MABTZD]; poly (MABTZD), poly(MABTZD-co-AA) and poly(MABTZD-co-AMAA), were prepared, and identified by FT-IR, 1H- and 13C-NMR spectra. The MABTZD unit contents in poly(MABTZD-co-AA) and poly(MABZD-co-AMAA) were 11.3 and 27.7 mol %, respectively. The number average molecular weights of the polymers, as determined by GPC, ranged from 16,800 to ...
Yuan Xiaofei - - 2005
To improve the stability of lysozyme-incorporated polyion complex (PIC) micelles in physiological condition, three types of hydrophobic groups, including phenyl (Phe), naphthyl (Nap), and pyrenyl (Py) terminal groups, were separately introduced to the omega-end of poly(ethylene glycol)-poly(alpha,beta-aspartic acid) block copolymers (PEG-P(Asp)). The goal was to enhance association forces between the ...
Hyk Wojciech - - 2005
The diffusion studies of the uncharged probe (1,1'-ferrocenedimethanol) have been successfully applied for the evaluation of the changes in the three-dimensional structure of poly(acrylic acids) of various molecular weights (ranging from 2000 to 4,000,000 g/mol) during their neutralization with a strong base. The qualitative picture of the macromolecule arrangement during ...
Permyakov Serge E - - 2005
It was recently shown that alpha-lactalbumin associated with oleic acid (HAMLET) interacts with core histones thereby triggering apoptosis of tumor cells (J. Biol. Chem. 2003, 278, 42131). In previous work, we revealed that monomeric alpha-lactalbumin in the absence of fatty acids can also interact with histones and, moreover, with basic ...
Takeuchi Kazuo - - 2005
The biological mechanisms underlying bone-titanium integration and biomechanical properties of the integrated bone are poorly understood. This study assesses intrinsic biomechanical properties of mineralized tissue cultured on titanium having different surface topographies. The osteoblastic phenotypes associated with mineral deposition and collagen synthesis underlying the biomechanical modulation are also reported. Rat ...
Hu C Y - - 2005
This work employs an anodic surfactant, sodium dodecyl sulfate (SDS), to improve the flotation performance of the electrocoagulation-flotation (ECF) process to treated fluoride containing semiconductor wastewater following calcium precipitation. The dissolved fluoride ions and CaF(2) particles in the wastewater after calcium precipitation were effectively removed in the ECF process simultaneously. ...
Oncag Gokhan - - 2005
This study investigated the effects of acidic soft drinks on the resistance of metal brackets to shear forces in vitro and in vivo. Thirty noncarious maxillary premolar teeth, scheduled for extraction for orthodontic purposes, were used in the in vivo group. Thirty other noncarious maxillary premolar teeth, already extracted for ...
Soeno Kohyoh - - 2005
The purpose of this study was to investigate the efficacy of an experimental dentin primer consisting of ascorbic acid (AA) and ferric chloride (Fe). Three exprimental primers - 10 wt%AA and 0.075 wt%Fe (i.e., 10AA-0.075Fe), 10AA-0Fe, and 0AA-0.075Fe - were prepared. Flattened dentin surfaces were first treated with phosphoric acid ...
Güler Ahmet Umut - - 2005
PURPOSE: The purpose of the present in vitro study was to examine shear bond strengths of resin composite to porcelain according to surface treatment. MATERIALS AND METHODS: One hundred eight feldspathic porcelain blocks were prepared. Specimens were divided into nine surface treatment groups: sandblasting with 50- or 110-microm Al2O3, acid ...
Guping Yangzhi - - 2005
A new class of biodegradable poly-amino acid, alpha,beta-poly[(N-hydroxypropyl/aminoethyl)-DL-Aspartamide-co-L-Lysine] (PHAAL), was synthesized by ring-opening of poly[succinimide-co-lysine](PSL) with n-propanolamine and ethylene diamine after thermal copolycondensation of DL-Aspartic acid and L-lysine under reduced pressure. Different ratio feeds of PSL were obtained and characterized by 1H-NMR, Fourier transformed infrared spectroscopy, X-ray, thermogravimetric analysis and ...
Platonova Galina A - - 2005
High-performance monolithic disk affinity chromatography was applied to the investigation of formation of complexes between (1) complementary polyriboadenylic and polyribouridylic acids, e.g. poly(A) and poly(U), respectively, (2) poly(A) and synthetic polycation poly(allylamine), pAA. Polyriboadenylic acid and poly(allylamine) were immobilized on macroporous disks (CIM disks). Quantitative parameters of affinity interactions between ...
Carniti Paolo - - 2005
The acid properties of pure and modified silica surfaces were studied by 2-phenylethylamine (PEA) desorption in a thermogravimetric (TGA) apparatus, carrying out the experiments at different heating rates (5 < beta/(degrees C.min(-1)) < 30). The samples, containing about 13 wt % alumina, titania, and zirconia, were prepared by the sol-gel ...
Lu Helen H - - 2005
The anterior cruciate ligament (ACL) is the most commonly injured intra-articular ligament of the knee, and limitations in existing reconstruction grafts have prompted an interest in tissue engineered solutions. Previously, we reported on a tissue-engineered ACL scaffold fabricated using a novel, three-dimensional braiding technology. A critical factor in determining cellular ...
van Dijk Martijn - - 2005
BACKGROUND: New applications of bioabsorbable polymer implants demand for histologic evaluation because a host tissue response is elicited and late complications after polymer implantation have been reported. Furthermore, in load-bearing regions an accelerated polymer degradation and foreign body reaction may be observed. METHODS: Lumbar interbody fusion procedures were performed using ...
Bartlett David W - - 2005
Tooth wear is a universal experience. The cause is usually a combination of erosion, attrition and abrasion. Attrition usually presents with flattened incisal and occlusal tooth surfaces which accurately inter-digitate. Erosion from dietary or gastric acids forms smooth lesions which typically appear as cupped occlusal/incisal and concave buccal/facial surfaces. When ...
Kataoka Kazunori - - 2005
The development of in vivo delivery systems for oligonucleotides and siRNA is strongly desired to achieve their clinical applications. Recently, polyplex micelles, which are formed through an electrostatic interaction between nucleic acid compounds (DNA and RNA) and poly(ethylene glycol) (PEG)-polycation block copolymers, have received much attention due to their nanometric-scaled ...
Nasr Karim - - 2005
Seven self-etching adhesives were studied on an experimental reconstituted human enamel model. The objective was to evaluate the acid dissociation step of the enamel minerals. The self-etching products were applied to the enamel specimens according to the manufacturers' instructions and then rinsed with distilled water. The aqueous calcium and phosphate ...
Salz Ulrich - - 2005
PURPOSE: The aim of this investigation was to determine the hydrolytic stability of conventional methacrylates in comparison with a new acrylic ether phosphonic acid and a bis(acrylamide) cross-linking monomer under acidic aqueous conditions and to confirm the potential of these new monomers as components in a self-etching enamel-dentin primer, based ...
Hudson R H E - - 2005
We have investigated the incorporation of C6-derivatives of uracil into polypyrimidine peptide nucleic acid oligomers (PNA). Starting with orotic acid (uracil-6-carboxylic acid) we have prepared a PNA monomer containing the methyl orotate nucleobase which is compatible with Fmoc-based synthesis. Treatment of the resin-bound oligomers with hydroxide or amines cleanly converted ...
Bishara Samir E - - 2005
AIM: To evaluate the use of new adhesive/primer materials, including an experimental self-etch primer and a cyanocrylate adhesive, to enhance the shear strength of orthodontic brackets bonded to porcelain surfaces. MATERIAL AND METHODS: Sixty porcelain maxillary central incisor teeth were used. The teeth were randomly divided into four groups: group ...
El-Housseiny Azza A - - 2005
Fissure sealant is an important tool in the prevention of dental caries. This study evaluated the effect of treating the enamel with topical fluoride gel prior to acid etching on sealant retention clinically (Part I) and in vitro (Part II). In part I a split mouth design using contralateral first ...
Raval Ankur - - 2005
The surface quality of coronary stents has a significant influence on its biocompatibility. Therefore, surface polishing is of paramount importance in the production and application of stents. In the present study, electropolishing is performed on 316LVM steel slotted tube coronary stents. Additionally, acid pickling, as a pretreatment of electropolishing, is ...
Simonovsky Felix I - - 2005
A series of linear and branched functionalized high-molecular-weight segmented poly (ether urethane)s and poly(ether urethane urea)s were prepared by chain-extending isocyanate pre-polymers based on poly(tetramethylene oxide) with molecular weight 1000 and 4,4'-diphenylmethane diisocyanate. Different functional groups were incorporated within the polymer backbone or on side-chains by using several chain extenders ...
Bezerra Ana Cristina Barreto - - 2005
Computerized analysis assessed quantitatively the efficacy of microabrasion using 37% phosphoric and 18% hydrochloric acids with pumice on removal of enamel opacities. Baseline and after one month photos were taken and analyzed by Paint Shop Pro 7 software and Image Pro Express 4.0. Nonparametric tests were used. Results depicted significant ...
Bilicić M Bubenik - - 2005
Synthesis of poly[alpha,beta-(N-2-hydroxyethyl-DL-aspartamide)]-thioglycolic acid (PHEA-TGA) conjugate as a new polyaspartamide thiomer is described. The parent polymer PHEA is chemically modified by introducing sulphydryl-bearing compound thioglycolic acid. By varying the reaction conditions several batches of PHEA-TGA conjugates were prepared and analyzed. Tensile studies revealed that total work of adhesion of PHEA-TGA ...
Celiberti Paula - - 2005
AIM: This study verified the effects of a self-etching adhesive applied on pre-etched fissures (phosphoric acid 35%) on microleakage, penetration ability and tag formation of a fissure sealant. METHODS: 80 extracted sound human molar teeth were randomly divided into four groups and bisected in two equal parts, forming two subgroups, ...
Kurosawa Shigeru - - 2004
This study synthesizes a tethered surface-grafted poly(acrylic acid) with quartz crystal microbalance (QCM) surfaces and provides detailed analysis of their properties and application. A tethered polyelectrolyte brush of poly(acrylic acid) is generated by first covering the substrate with a plasma-polymerized allyl alcohol (pp-AA) film, changing the polymerization initiators (bromination), and ...
Ciardelli G - - 2004
Cross-linked poly(methylmethacrylate-co-methacrylic acid) nanospheres were imprinted with theophylline through template radical polymerisation in diluted acetonitrile solution. This study will focus on the effect of functional monomer nature used (methylmethacrylate and/or methacrylic acid) in the recognition and in the release of template in order to develop a material with combined properties ...
Koumoto Kazuya - - 2004
Thermal stabilization of the complex between polycytidylic acid [poly(C)] and the modified schizophyllan (SPG) whose hydrophilic side-chain glucose groups are selectively removed utilizing mild Smith-degradation has been investigated. With the decrease in the side-chain glucose groups of schizophyllan, the complex with poly(C) can be considerably stabilized compared with unmodified SPG; ...
Jo Y S - - 2004
A method to construct synchronous delivery systems via direct self-assembly of Au nanoparticles on the poly[(N-isopropylacrylamide-r-acrylamide)-b-L-lactic acid] (PNAL) nanospheres has been presented in this paper. To achieve amphiphilic diblock terpolymer, hydrophobic poly (L-lactic acid) (PLLA) block was added to poly(N-isopropylacrylamide- r-acrylamide) (PNA) block via Michel-type addition reaction. Lower critical solubility ...
De T K - - 2004
In ophthalmic drug delivery, a major problem is retaining an adequate concentration of a therapeutic agent in the pre-corneal area. Polycarboxylic acid carriers such as polyacrylic acid and polyitaconic acid in sub-colloidal, nanoparticulate hydrogel form have a strong potential for sustained release of a drug in ocular delivery. Formulations have ...
Barbanti S H - - 2004
The use of bioresorbable polymers as a support for culturing cells has received special attention as an alternative for the treatment of lesions and the loss of tissue. The aim of this work was to evaluate the degradation in cell culture medium of dense and porous scaffolds of poly(L-lactic acid) ...
< 5 6 7 8 9 10 11 12 13 14 15 >