bluuebunny/crossref_metadata_2025 huggingface dataset:
Municipalização da saúde no Brasil: diferenças regionais, poder do voto e estratégias de governo
Authors: Arretche Marta , Marques Eduardo
Published: April 2005

Este artigo examina a extensão e os determinantes do processo de municipalização da política de saúde no Brasil, com base na análise estatística de dados para 1.643 municípios localizados em diferentes regiões brasileiras. Inicialmente, analisa o alcance de duas dimensões do projeto de municipalização da saúde: a oferta municipal de serviços de atenção básica e a municipalização da gestão da rede hospitalar local. Em seguida, discute o impacto de distintas variáveis na decisão municipal em favor da municipalização: porte e localização do município, suas capacidades fiscais, as preferências do eleitorado local, a competição eleitoral, o contexto local para a tomada de decisão, bem como o impacto local da estratégia federal de descentralização.
Associativismo, participação e cultura cívica: O potencial dos conselhos de saúde
Authors: Labra Maria Eliana , Figueiredo Jorge St. Aubyn de
Published: April 2005

No Brasil, a democratização e a descentralização abriram espaço para inúmeras experiências de participação popular em arenas de decisão de políticas públicas. O setor saúde se destaca no país e na América Latina pelo funcionamento de mais de 5.500 conselhos de saúde, nos quais a representação da sociedade civil organizada é compartilhada de forma paritária com autoridades setoriais, prestadores profissionais e institucionais e trabalhadores do setor. Este trabalho apresenta resultados de pesquisa que buscou traçar um perfil sociopolítico dos representantes dos usuários nos conselhos de saúde do Estado do Rio de Janeiro. A exposição aborda elementos teóricos relativos a temas como democracia, associativismo e cultura cívica, examina a democratização brasileira, a reforma do sistema de saúde e os conselhos de saúde, e analisa os dados da investigação. Entre as considerações finais, postula-se que a participação nos conselhos de saúde fomenta um círculo virtuoso caracterizado pelo envolvimento dos cidadãos em questões de interesse geral, pela acumulação de capital social e pelo despertar de uma cultura cívica, contribuindo, em última instância, para o fortalecimento da democracia.
The Observatory of the Américas as a network in environmental and worker health in the Americas
Authors: Siqueira Carlos Eduardo , Carvalho Fernando
Published: April 2005

This article reviews the scope of several Observatories found by a search in the Internet through the Google search engine. After examining these observatories, it describes the aims and initial accomplishments of the Observatory of the Americas as a network of professionals and activists from different countries in the Americas. The article concludes with a discussion of the pattern identified among these observatories: they may be clearinghouses or networks, or both.
Bases para uma política nacional de ciência, tecnologia e inovação em saúde
Authors: Guimarães Reinaldo
Published: April 2005

O texto discute as bases para uma Política Nacional de Ciência, Tecnologia e Inovação em Saúde (PNCTI/S) como elemento estruturador do esforço brasileiro de pesquisa em saúde. Pelo menos desde a fundação do CNPq, em 1951, esse imenso esforço, que no Brasil se traduz por um conjunto de quase 18.000 pesquisadores atuantes em 4.900 grupos de pesquisa, não se sustenta em uma política pública explícita de pesquisa em saúde. O texto adota o ponto de vista de que o organismo adequado para constituir essa política é o Ministério da Saúde, de resto como ocorre na maioria dos países com tradição em pesquisa. Uma PNCTI/S necessita ser respaldada em uma agenda de pesquisa prioritária, cuja construção deve ser pactuada entre os atores mais relevantes, quais sejam os pesquisadores e os gestores de saúde. Deve também prever novos canais e fontes de fomento. A PNCTI/S deve ser extensiva no que se refere à cadeia do conhecimento e inclusiva no que toca aos pesquisadores e instituições de pesquisa. Por fim, deve sustentar-se na busca da eqüidade em saúde e na prática de padrões éticos de pesquisa.
Avaliação de política nacional de promoção da saúde
Authors: Campos Gastão Wagner , Barros Regina Benevides de , Castro Adriana Miranda de
Published: April 2005

O artigo discute a promoção da saúde como uma estratégia importante para o enfrentamento dos problemas sanitários no contemporâneo e a melhoria da qualidade de vida da população em sua relação indiscutível com os compromissos éticos da política e do sistema de saúde brasileiros. Nele também são apresentadas as bases da Política Nacional de Promoção da Saúde que o Ministério da Saúde vem construindo.
Developmentally defined regulation of thyroid hormone metabolism by glucocorticoids in the rat
Authors: Van der Geyten S , Darras V M
Published: April 2005

Glucocorticoids are known regulators of thyroid function in vertebrates. In birds they have clear tissue-specific and age-dependent effects on thyroid hormone metabolism. In mammals, however, few studies exist addressing these aspects using an in vivo model system. We therefore set out to examine the acute effects of a single dose of dexamethasone (DEX) on plasma 3,5,3′-tri-iodothyronine (T3) and thyroxine (T4) levels, as well as on the activity of the different deiodinases in liver, kidney and brain in the developing rat. In 20-day-old fetuses (E20), glucocorticoids had no effects on circulating thyroid hormone levels despite their clear effects on hepatic and renal deiodinases, thereby indicating that under these conditions circulating thyroid hormone levels are more dependent on thyroidal secretion than on peripheral deiodination. In contrast, in 5-day-old rat pups, DEX did not seem to have any effects on hepatic and renal T3 production (via the type I deiodinase), whereas type III deiodinase (D3) activity in both these tissues increased significantly. These observations therefore suggested that the DEX-induced increase in circulating T3 levels is a direct consequence of the increase in plasma T4 levels. In 12-day-old pups (P12), however, the main effect of glucocorticoids on circulating levels was by increasing inner ring deiodination T3 through induction of D3 in both liver and kidney. Finally, in the brain, glucocorticoids stimulated thyroid hormone activity only during a short period of time (between E20 and P12) that largely overlaps with the transient window in time during which brain development is thyroid hormone sensitive. This was in contrast to the E20 and P12 brain, where the glucocorticoid-induced changes in type II deiodinase and D3 seemed to favor a status quo in local T3 availability.
Defect detection capability of pulsed transient thermography
Authors: Quek S , Almond D P
Published: April 2005

Pulsed thermography is gaining wide acceptance in the aerospace, automotive and power generation industries, owing to its quickness of inspection, repeatability and sensitivity. Recently, advancement in pulsed thermographic data processing has been made by Thermal Wave Imaging Inc (TWI)
in USA. A technique called thermographic signal reconstruction (TSR) has been devised. By approximating the raw data sequence with logarithmic polynomial function, this technique produces three types of images, namely: the synthetic image and first and second time derivative images. These
images facilitate detection of smaller and/or deeper defects, which are undetectable on the raw data sequence. In this work, qualitative and quantitative assessments of the TSR images have been conducted using aluminium, CFRP and GFRP composites and mild steel samples. Results have validated
the significant enhancement of the TSR process. A quantitative study performed using CFRP composite has shown that an improvement of 60% in detection depth has achieved for defects greater than 4 mm diameter. Defects have been imaged at depths greater than 5 mm in composites.
2% Sodium Fluoride‐Iontophoresis Compared to a Commercially Available Desensitizing Agent
Authors: Singal Pankaj , Gupta Rajan , Pandit Nymphea
Published: April 2005

Background: Dentin hypersensitivity is a common clinical condition and age‐old complaint, presenting problems to both the patient and the dentist. Besides causing discomfort, the condition may deter a person from establishing or maintaining adequate oral hygiene procedures, further complicating oral health. The failure to practice satisfactory plaque control has well‐established consequences on gingival and periodontal health. Thus, a cycle of sensitive teeth leading to reduced plaque control, more periodontal disease, and more recession may be established.

Methods: The hypersensitive teeth were identified by the patient and verified by the light stroke of a dental explorer along the cervical area of all teeth present. Subjects fulfilling the inclusion and exclusion criteria were evaluated using tactile, 1‐second air blast, and cold water stimuli, and the subject's response was recorded on the verbal rating scale. A total of 425 teeth from 50 patients included in this study were randomly divided into two groups: group 1, who received 2% sodium fluoride‐iontophoresis (NaF) and group 2, who received an aqueous solution of hydroxy‐ethyl‐methacrylate and glutaraldehyde (HEMA‐G). The teeth were evaluated immediately after treatment and at 2 weeks, 1 month, and 3 months. In case of failure at the 2‐week interval, the affected tooth was retreated with the same drug as before and evaluated further.

Results: The results were statistically analyzed, and it was found that group 1 treatment was more effective than group 2 at 1‐ and 3‐month intervals. There was a comparatively greater recurrence of hypersensitivity in group 2. A comparable number of teeth required repeat dosage in both groups. Teeth which required repeat dosage had greater mean discomfort scores at baseline for all three tests than the teeth which did not require a repeat dose.

Conclusions: Both agents showed significant reduction in sensitivity at all time intervals compared to baseline; however, NaF had a comparatively greater effect than HEMA‐G at both the 1‐ and 3‐month intervals; an almost equal number of teeth in both groups required repeat doses. Teeth with a higher initial sensitivity score required a repeat dose. Both agents were found to be equally effective immediately after application; the 2% NaF was comparatively better than HEMA‐G in providing long‐term relief. J Periodontol 2005;76:351‐357.
Relative Contribution of Patient‐, Tooth‐, and Site‐Associated Variability on the Clinical Outcomes of Subgingival Debridement. I. Probing Depths
Authors: D'Aiuto Francesco , Ready Derren , Parkar Mohammed , Tonetti Maurizio S.
Published: April 2005

Background: The objective of this clinical trial was to assess the relative contribution of patient‐, tooth‐, and site‐associated variables on changes in probing depths (PD) following delivery of a standard non‐surgical phase of periodontal therapy.

Methods: Ninety‐four (94) systemically healthy subjects with severe generalized periodontitis were included in this 6‐month prospective longitudinal study. Medical, periodontal, and microbiological parameters were collected at baseline and 2 and 6 months after completion of oral hygiene instructions, motivation, and subgingival debridement using a piezoelectric instrument. The relative contribution of patient‐, tooth‐, and site‐associated variables was evaluated with a hierarchical multilevel analysis.

Results: Eighty percent (80%) of variability in PD reductions was attributed to site level parameters, while 12% was at the tooth level and 8% at the patient level. The multilevel analysis associated PD reductions with patient factors (cigarette smoking status and carriage of the rare allele of a specific polymorphism for the interleukin‐6 [IL‐6] gene), tooth factors (tooth mobility and tooth type), and site factors (mesial and distal location). Cigarette smoking and carriage of the rare allele of the IL‐ 6‐174 G/C polymorphism were associated with less PD reduction. Incisors and canines responded better than premolars and molars. A dose‐dependent effect of mobility was observed: teeth with higher baseline mobility resulted in significantly greater decreases in PD. At the site level, greater reductions were observed at interdental sites (compared to facial or oral), and at deeper sites (1.2 mm for 4 to 5 mm pockets and 2.4 mm for pockets ≥6 mm).

Conclusion: These data provided an estimation of the relative contribution of site‐, tooth‐, and patient‐associated variables in terms of PD reductions following a standard course of machinedriven subgingival debridement. J Periodontol 2005;76:398‐405.
Lactate Dehydrogenase Activity in Human Gingival Crevicular Fluid During Orthodontic Treatment: A Controlled, Short‐Term Longitudinal Study
Authors: Perinetti Giuseppe , Serra Emanuela , Paolantonio Michele , Bruè Claudia , Meo Silvio Di , Filippi Maria Rita , Festa Felice , Spoto Giuseppe
Published: April 2005

Background: During orthodontic tooth movement, the early response of periodontal tissues to mechanical stress is an acute inflammatory one. This study uses a longitudinal design to examine lactate dehydrogenase (LDH) activity in gingival crevicular fluid (GCF) to determine if GCF LDH can be used as a diagnostic aid in monitoring tooth movement and tissue response during orthodontic treatment.

Methods: Seventeen patients (mean age: 16.1 years) participated in the study. Each patient was undergoing treatment for distal movement, and an upper first molar served as the test tooth (TT), while the contralateral (CT) and antagonist (AT) teeth were used as controls. The CT was included in the orthodontic appliance, but was not subjected to the distal movement; the AT was free from any orthodontic appliance. The GCF around the experimental teeth was harvested from both mesial and distal tooth sites immediately before appliance activation, and on days 7, 14, and 21. Clinical gingival conditions were also recorded.

Results: Gingival crevicular fluid LDH activity was significantly elevated in all sites of the TT and CT, as compared to the AT, where LDH activity remained at the baseline level throughout the study. Enzyme activity levels were also greater in the TT than in the CT, and in the compression sites.

Conclusions: Our results suggest that GCF LDH levels reflect the biological activity that takes place in the periodontium during orthodontic movement, and therefore they can be used as a diagnostic tool for monitoring for correct orthodontic tooth movement in clinical practice. J Periodontol 2005;76:411‐417.
Calprotectin Expression in Human Monocytes: Induction by Porphyromonas gingivalis Lipopolysaccharide, Tumor Necrosis Factor‐α, and Interleukin‐1β
Authors: Suryono  , Kido Jun‐ichi , Hayashi Noriko , Kataoka Masatoshi , Nagata Toshihiko
Published: April 2005

Background: Calprotectin is a major cytosolic protein of monocytes and granulocytes. It is increased in inflammatory tissues and is detected at high levels in the gingival crevicular fluid (GCF) of periodontitis patients. We previously reported that lipopolysaccharide of Porphyromonas gingivalis (P‐LPS) and cytokines induced the release of calprotectin from monocytes isolated from human peripheral blood. The mechanisms of calprotectin expression and presence of its regulation factors in periodontal disease are unknown. On the other hand, P‐LPS and cytokines are significant etiologic factors in the initiation and progression of periodontal diseases. In this study, we investigated the expression and production of calprotectin from human monocytes by examining the effects of lipopolysaccharide of P‐LPS, tumor necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β).

Methods: Monocytes were isolated from the peripheral blood of healthy donors and cultured in the presence or absence of P‐LPS, TNF‐α, or IL‐1β. The expressions of calprotectin mRNAs (MRP8 and MRP14) were detected by Northern blotting. The contents of calprotectin in the cells and medium fractions were determined by enzyme‐linked immunosorbent assay (ELISA). The DNA binding activity of C/EBPα, a transcription factor of MRP14, was assessed by electrophoretic mobility shift DNA‐binding assay (EMSA).

Results: P‐LPS, TNF‐α, and IL‐1β induced MRP8/14 mRNAs and calprotectin production in monocytes. These factors also induced DNA CEBPα binding activity in monocytes. P‐LPS increased MRP14 mRNA expression in monocytes to the maximum level, about two times the control level after 24 hours treatment, but did not enhance the basal level of MRP8. When the effects of TNF‐α and IL‐1β on those mRNAs were investigated, both MRP8 and MRP14 significantly increased to about 2‐ and 2.5‐fold the control level, respectively. Increases of MRP8/14 mRNA expression were followed by their protein production at about 2‐fold the basal amount. DNA binding activity of C/EBPα was increased in P‐LPS, TNF‐α, and IL‐1β‐treated monocytes.

Conclusions: These results demonstrate that P‐LPS, TNF‐α, and IL‐1β induce calprotectin production from human monocytes and that this production is associated with the activation of DNA C/EBPα binding complex. J Periodontol 2005;76:437‐442.
The Use of Guided Tissue Regeneration Principles in Endodontic Surgery for Induced Chronic Periodontic‐Endodontic Lesions: A Clinical, Radiographic, and Histologic Evaluation
Authors: Britain Steven K. , von Arx Thomas , Schenk Robert K. , Buser Daniel , Nummikoski Pirkka , Cochran David L.
Published: April 2005

Background: Chronic periodontic‐endodontic lesions are not uncommon in clinical practice and their regenerative capacity has long been questioned. However, there are no published studies investigating the application of guided tissue regeneration techniques in combination with endodontic surgery using an induced perio‐endo defect model. This study evaluated the clinical, radiographic, and histologic outcomes of three surgical procedures used to treat induced perio‐endo lesions.

Methods: Pulpal necrosis was induced in foxhounds along with surgical removal of radicular buccal bone. After 4 weeks, chronic lesions were clinically and radiographically assessed. Treatment surgery consisted of apicoectomy, root canal instrumentation, and retrofilling with mineral trioxide aggregate. Teeth were then assigned to one of the following treatment groups: open flap debridement only (OFD), OFD with bioabsorbable porcinederived collagen membrane (BG), or OFD with BG and anorganic bovine bone matrix (BO/BG). Clinical parameters and standardized radiographs were assessed at defect creation; treatment surgery; and at 1, 2, 4, and 6 months. Animals were sacrificed at 6 months and specimens prepared for histometric analysis.

Results: Clinical and radiographic conditions improved during the study period. Mean epithelial attachment was similar between all groups. Mean connective tissue attachment for groups OFD, BG, and BO/BG was 3.79 mm, 2.63 mm, and 1.75 mm, respectively, and mean radicular bone height was 2.16 mm, 3.24 mm, and 3.45 mm, respectively. Statistically significant increases in the amount of new cementum were observed in groups BG and BO/BG when compared with OFD (P <0.05).

Conclusions: Treatment of combined induced perio‐endo lesions using bioabsorbable collagen membranes alone or in combination with anorganic bovine bone matrix resulted in increased amounts of bone, periodontal ligament, and significant increases in the amount of new cementum when compared to open flap debridement in a canine model. J Periodontol 2005;76:450‐460.
Underestimation of Cardiovascular Disease Mortality Among Maine American Indians: The Role of Procedural and Data Errors
Authors: Graber Judith M. , Corkum Brenda E. , Sonnenfeld Nancy , Kuehnert Paul L.
Published: April 2005

We collaborated with Maine American Indian tribes to evaluate racial coding on death certificates and the effects of coding errors on estimation of cardiovascular disease (CVD) mortality. Lists of tribal decedents were matched to death certificates; 38.5% were misclassified (17.8% coding errors; 20.7% data entry errors). After errors were corrected, CVD mortality trends were similar between American Indians and all Maine residents. Racial misclassification occurred during a period when budget cuts had prompted procedural changes.
Measuring the Health Status Gap for American Indians/Alaska Natives: Getting Closer to the Truth
Authors: Puukka Emily , Stehr-Green Paul , Becker Thomas M.
Published: April 2005

Objectives. We compared the historical method of calculating cancer incidence rates with 2 new methods to determine which approach optimally estimates the burden of cancer among the Northwest American Indian/Alaska Native (AIAN) population.

Methods. The first method replicates the traditional way of calculating race-specific rates, and the 2 new methods use probabilistic record linkages to ascertain cancer cases. We indirectly adjusted all rates to the standard 2000 US population.

Results. Whereas the historical cancer incidence rates for all races are more than double those for the AIAN population, this apparent gap is considerably narrower when the all-race rates are compared with AIAN-specific rates calculated with probabilistic linkage methods. Similarly, there is no meaningful difference in incidence rates for selected site- and gender-specific cancers between the AIAN population and all races combined, and, in fact, some of these rates may be higher among the AIAN population.

Conclusions. Our results suggest that the burden of cancer among the AIAN population is considerably higher than was previously understood. We recommend that a standardized approach based on probabilistic linkage methods be adopted and that adequate financial and technical support be made available for conducting routine linkage studies throughout Indian communities.
Causes of Visual Impairment and Common Eye Problems in Northwest American Indians and Alaska Natives
Authors: Mansberger Steven L. , Romero Francine C. , Smith Nicole H. , Johnson Chris A. , Cioffi George A. , Edmunds Beth , Choi Dongseok , Becker Thomas M.
Published: April 2005

Objectives. Little information exists regarding the causes of visual impairment and the most common eye problems in American Indians/Alaska Natives.

Methods. We randomly sampled American Indians/Alaska Natives older than 40 years from 3 tribes within the Northwest region.

Results. We found a higher prevalence of visual impairment and normal-tension glaucoma, as well as a lower prevalence of ocular hypertension, in American Indians/Alaska Natives compared with previous results in other racial/ethnic groups.

Conclusions. American Indians/Alaska Natives have a need for vision correction. Future interventions in American Indians/Alaska Natives should include providing spectacles for refractive error, detecting glaucoma, and preventing visual impairment from age-related maculopathy and cataracts.
Temperature gradients in blown film bubbles
Authors: Sidiropoulos V. , Vlachopoulos J.
Published: April 2005

It is argued that the assumption of negligible temperature gradients across the thickness in blown film extrusion is not valid in the vicinity of the die exit. Numerical simulation of heat transfer involving convection and radiation shows significant temperature differences between the inside and outside film surfaces, which gradually decrease and eventually become negligible near the frost line. The differences are influenced by the magnitude of local heat transfer coefficients. In blown film lines having internal bubble cooling (IBC), temperature gradients in the thickness direction may be reduced, but still they cannot be considered negligible for typical production rates. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24:83–90, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20039
Simulation and visualization of flow in a new miniature mixer for multiphase polymer systems
Authors: Breuer Orna , Chen Hongbing , Lin Bin , Sundararaj Uttandaraman
Published: April 2005

A newly designed mixer, the Alberta polymer asymmetric minimixer (APAM), was compared to the MiniMAX molder with flow simulation and flow visualization techniques to evaluate the performance of the mixers. The APAM has a unique, asymmetric design consisting of a varying clearance between the rotor blade tips and the cup wall, which enables the material to be squeezed, stretched, and kneaded in high‐shear and converging zones. Flow simulation showed that substantial folding and axial movement occurred in this mixer and that the pressure and velocity profiles exhibited high values at the rotor tip with the smallest rotor tip/cup clearance. In contrast, the MiniMAX molder had very simple flow patterns, which were insufficient to induce good dispersive and distributive mixing. These results concurred with those from an earlier work that studied the structure of blends and nanocomposites processed in the APAM compared to other polymer processing equipment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 136–142, 2005
Thin, highly crosslinked polymer layer synthesized via photoinitiated graft copolymerization on a self‐assembled‐monolayer‐coated gold surface
Authors: Yang Hu , Lazos Dimitrios , Ulbricht Mathias
Published: April 2005

A thin, highly crosslinked layer was grafted onto an alkyl thiol self‐assembled‐monolayer (SAM)‐coated gold surface with N,N′‐methylene bisacrylamide (MBAA), a widely used crosslinker with two polymerizable groups, as the monomer. Surface‐initiated photografting copolymerization was achieved through the immobilization of the hydrogen‐abstraction photoinitiator benzophenone on the hydrophobic alkyl surface via physical adsorption and subsequent UV irradiation in the presence of an MBAA solution. The growth of the grafted poly‐MBAA layers seemed to produce dendritic structures with low surface coverage. At a higher monomer concentration (15 g/L of water), full coverage of the gold surface with a thin layer was obtained and proved by scanning force microscopy and contact‐angle measurements. The evaluation of the gold, gold–SAM, and gold–SAM/grafted poly‐MBAA layers with a surface plasmon resonance sensor system revealed that the photografted, thin, highly crosslinked polyacrylamide layers had a very low affinity toward the adsorption of protein. Therefore, this provides a very promising approach to tailoring materials for sensors and other applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 158–164, 2005
Immobilization of catalase on a novel polymer support, crosslinked polystyrene ethylene glycol acrylate resin: Role of the macromolecular matrix on enzyme activity
Authors: Kumar G. S. Vinod , Kumar K. Santhosh
Published: April 2005

Crosslinked polystyrene ethylene glycol acrylate resin (CLPSER) was developed for the immobilization of the enzyme catalase by the introduction of a crosslinker, O,O′‐bis(2‐acrylamidopropyl) poly(ethylene glycol)1900, to styrene. The crosslinker was prepared by the treatment of acryloyl chloride with O,O′‐bis(2‐aminopropyl) poly(ethylene glycol)1900 in the presence of diisopropylethylamine. The resin was characterized with IR and 13C‐NMR spectroscopy. The catalytic activity of the catalase‐immobilized system of CLPSER was compared with divinylbenzene‐crosslinked polystyrene, ethylene glycol dimethacrylate crosslinked polystyrene, and 1,4‐butanediol dimethacrylate crosslinked polystyrene systems. Crosslink levels of 2, 8, and 20 mol % were evaluated. Among these crosslinked systems, the 2 mol % system was found to be most suitable to support catalytic activity. When a long flexible hydrophilic poly(ethylene glycol) crosslink, introduced between the polystyrene (PS) backbone and functional groups was used for immobilization, the extent of coupling and enzyme activity increased. Depending on the nature of the support, the catalytic activity of the system varied. The hydrophilic CLPSER support was most efficient for immobilization compared to the other PS‐based supports. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 8–19, 2005
Model for reaction‐assisted polymer dissolution in LIGA
Authors: Larson Richard S.
Published: April 2005

A new chemically oriented mathematical model for the development step of the LIGA process is presented (LIGA is an acronym for the German words Lithographie, Galvanoformung, and Abformung). The key assumption is that the developer can react with the polymeric resist material to increase the solubility of the latter, thereby partially overcoming the need to reduce the polymer size. The ease with which this reaction takes place is assumed to be determined by the number of side‐chain scissions that occur during the X‐ray exposure phase of the process. The dynamics of the dissolution process are simulated by the solution of the reaction diffusion equations for this three‐component, two‐phase system, the three species being the unreacted and reacted polymers and the solvent. The mass fluxes are described by multicomponent diffusion (Stefan–Maxwell) equations, and the chemical potentials are assumed to be given by the Flory–Huggins theory. Sample calculations are used to determine the dependence of the dissolution rate on key system parameters such as the reaction rate constant, polymer size, solid‐phase diffusivity, and Flory–Huggins interaction parameters. A simple photochemistry model is used to relate the reaction rate constant and the polymer size to the absorbed X‐ray dose. The resulting formula for the dissolution rate as a function of the dose and temperature is fit to an extensive experimental database to evaluate a set of unknown global parameters. The results suggest that reaction‐assisted dissolution is very important at low doses and low temperatures, the solubility of the unreacted polymer being too small for it to be dissolved at an appreciable rate. However, at high doses or at higher temperatures, the solubility is such that the reaction is no longer needed, and dissolution can take place via the conventional route. These results provide an explanation for the observed dependences of both the rate of dissolution and its activation energy on the absorbed dose. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 25–37, 2005
Study on preparation and tribological properties of epoxy resin/SiO2 hybrid thin film
Authors: Qi Chenze , Gao Hui , Yan Fengyuan , Liu Weimin , Bao Gaoqiang , Sun Xudong , Chen Jianmin , Zheng Xiaoming
Published: April 2005

A series of organic–inorganic hybrid thin films are prepared by means of the sol–gel process in curing epoxy and hydrolyzing tetraethoxysilane. The epoxy group of γ‐glycidyloxipropyltrimethoxysilane can be incorporated into the sol–gel network to form the interaction between the inorganic and organic phases. Inorganic and organic components can be mixed on the nanometer scales, thereby leading to the formation of so‐called hybrid materials. Transmission electron microscopy examinations and atomic force microscopy are employed to study the morphology and roughness of the samples, respectively. In addition, the tribological behavior of dip‐coating thin films is evaluated by the use of a dynamic/static friction precision measurement apparatus (unidirectional sliding tester). The influences of the contents of both the filler and the coupling agent on the tribological properties of the nanocomposite thin films are systematically studied. These results indicate that the films sliding against a GCr15 steel ball display excellent antiwear and friction reduction performance. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 38–43, 2005
Preparation of titanium dioxide/poly(methyl methacrylate‐co‐n‐butyl acrylate‐co‐methacrylic acid) hybrid composite particles via emulsion polymerization
Authors: Yu Dong‐Guk , An Jeong Ho , Bae Jin Young , Ahn Seong Deok , Kang Seung‐Youl , Suh Kyung Soo
Published: April 2005

Titanium dioxide core and polymer shell composite poly(methyl methacrylate‐co‐n‐butyl acrylate‐co‐methacrylic acid) [P(MMA‐BA‐MAA)] particles were prepared by emulsion copolymerization. The stability of dispersions of TiO2 particles in aqueous solution was investigated. The addition of an ionic surfactant, sodium lauryl sulfate, which can be absorbed strongly at the TiO2/aqueous interface, increases the stability of the TiO2 dispersion effectively by increasing the absolute value of the ζ potential of the TiO2 particles. The adsorption of the nonionic surfactant, Triton X‐100, on the surface of TiO2 particles is less than that of the ionic surfactant. Fourier transform IR spectroscopy was used to measure the content of MAA composite particles. Dynamic light scattering characterized the composite particle size and size distribution. The field‐emission scanning electron microscopy results for the composite particles showed a regular spherical shape, and no bare TiO2 was detected on the entire surface of the samples. The composite particles that were produced showed good spectral reflectance compared to bare TiO2. Thermogravimetric analysis results indicated the encapsulated TiO2 and estimated density of composite particles. There was up to 78.9% encapsulated TiO2 and the density ranged from 1.76 to 1.94 g/cm3. The estimated density of the composite particles is suitable at 1.73 g/cm3, which is due to density matching with the suspending fluid. The sedimentation experiment indicates that reducing the density mismatch between the composite particles and suspending fluid may enhance the stability. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 72–79, 2005
Effect of electron beam irradiation on physical properties of ultrahigh molecular weight polyethylene
Authors: Kim Sungsik , Kang Phil Hyun , Nho Young Chang , Yang O‐Bong
Published: April 2005

If a large amount of polymer radicals remain trapped after the irradiation of ultrahigh molecular weight polyethylene (UHMWPE), the radicals may result in a significant alteration of its physical properties during long‐term shelf storage and implantation. An electron spin resonance spectroscopic study was undertaken to investigate the remaining free radicals in UHMWPE after electron beam irradiation up to 500 kGy in air and an N2 environment. Heat treatment was employed at 110 and 145°C for various periods of time to decay the free radicals. The free radicals were rapidly decayed for 1 h and gradually decayed as a function of time with the heat treatment. The decay of the free radicals was completed more rapidly with a heat treatment at 145°C than at 110°C. Therefore, a longer heat treatment time is required to scavenge all the free radicals formed in UHMWPE at 110°C. The oxidation profiles showed that the oxidation index of the heat‐treated UHMWPE was lower than the oxidation index of the non‐heat‐treated UHMWPE. The heat treatment of irradiated UHMWPE can substantially reduce the concentration of free radicals; therefore, UHMWPE has resistance against long‐term oxidative degradation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 103–116, 2005
Shrinking rate of conducting grains in HCl–protonated polyaniline, polypyrrole, and polypyrrole/polyaniline blends with their thermal aging
Authors: Sakkopoulos S. , Vitoratos E. , Dalas E. , Kyriakopoulos N. , Malkaj P. , Argyreas T.
Published: April 2005

The dc electrical conductivity (σ) of HCl‐protonated polyaniline, polypyrrole, and their blends was measured from 80 to 300 K for thermal aging times between approximately 0 and 600 h. The thermal aging took place at 70°C under room atmosphere. The change of σ with the temperature (T) and the decrease of σ with the thermal aging time (t) are consistent with a granular metal type structure, in which conductive grains are randomly distributed into an insulating matrix. Aging makes the grains shrink in a corrosion‐like process. From σ = σ(T) measurements the ratio s/d, where s is the average separation between the grains and d their diameter, as well as the rate d(s/d)/dt of their decrease with t were calculated. These revealed that the conductive grains consist of a shell, in which aging proceeds at a decreasing rate, and a central core, which is consumed at a much slower rate. Our measurements not only permitted the estimation of the shell thickness, which lies between 0 and 5 Å, but also gave quantitative information about the quality of the shells and the cores from their aging rates. The shells are consumed with an average rate of d(s/d)/dt = 6.6 × 10−4 (h−1), which is about 5 times greater than the more durable cores. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 117–122, 2005
Efficient circumferential superdrawing
Authors: Aneja Arun Pal
Published: April 2005

Amorphous poly(ethylene terephthalate) (PET) can be stretched at low tension without causing any observable crystallization at temperatures above the glass‐transition temperature. The resulting increased length with no measurable change in orientation is called superdrawing. Superdrawing of hollow PET fibers in the circumferential direction was demonstrated earlier. This behavior is accompanied by an increase in fiber voids caused by a combination of air expansion and water permeation. The present work describes efficient techniques for superdrawing in the circumferential direction only. The process develops large void (>65%) fibers starting from standard 15% void spun supply. It is not possible to obtain such large voids in the longitudinal direction in low denier‐per‐filament fibers via direct melt spinning. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 123–127, 2005
Synthesis and properties of polystyrene–clay nanocomposites via in situ intercalative polymerization
Authors: Qi Rongrong , Jin Xing , Nie Jinghui , Yu Wei , Zhou Chixing
Published: April 2005

Organophilic montmorillonite (MMT) was prepared by ion exchange between Na+ ions in the clay and twin benzyldimethyloctadecylammonium bromine cations in an aqueous medium. The organophilic MMT particles were easily dispersed and swollen in styrene monomer. Polystyrene–MMT nanocomposites were prepared by the free‐radical polymerization of styrene containing dispersed clay. The intercalation spacing in the nanocomposites and the degree of dispersion of these composites were investigated with X‐ray diffraction and transmission electron microscopy, respectively. The nanocomposites had higher weight‐average molecular weights, lower glass‐transition temperatures, and better thermal stability (the decomposition temperature was improved by ca. 70°C) than the virgin polystyrene. The rheological behavior of the polystyrene–MMT nanocomposites was also studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 201–207, 2005
Scaling phenomena in the growth dynamics of scientific output
Authors: Matia Kaushik , Nunes Amaral Luis A. , Luwel Marc , Moed Henk F. , Stanley H. Eugene
Published: April 2005

We analyze a set of three databases at different levels of aggregation: (a) a database of approximately 106 publications from 247 countries published from 1980–2001, (b) a database of 508 academic institutions from the European Union (EU) and 408 institutes from the United States for the 11‐year period of 1991–2001, and (c) a database of 2,330 Flemish authors published in the period from 1980–2000. At all levels of aggregation we find that the mean annual growth rates of publications is independent of the number of publications of the various units involved. We also find that the standard deviation of the distribution of annual growth rates decays with the number of publications as a power law with exponent ≈ 0.3. These findings are consistent with those of recent studies of systems such as the size of research and development funding budgets of countries, the research publication volumes of U.S. universities, and the size of business firms.
Computational tools for Brassica–Arabidopsis comparative genomics
Authors: Beckett Paul , Bancroft Ian , Trick Martin
Published: April 2005

Recent advances, such as the availability of extensive genome survey sequence (GSS) data and draft physical maps, are radically transforming the means by which we can dissect Brassica genome structure and systematically relate it to the Arabidopsis model. Hitherto, our view of the co‐linearities between these closely related genomes had been largely inferred from comparative RFLP data, necessitating substantial interpolation and expert interpretation. Sequencing of the Brassica rapa genome by the Multinational Brassica Genome Project will, however, enable an entirely computational approach to this problem. Meanwhile we have been developing databases and bioinformatics tools to support our work in Brassica comparative genomics, including a recently completed draft physical map of B. rapa integrated with anchor probes derived from the Arabidopsis genome sequence. We are also exploring new ways to display the emerging Brassica–Arabidopsis sequence homology data. We have mapped all publicly available Brassica sequences in silico to the Arabidopsis TIGR v5 genome sequence and published this in the ATIDB database that uses Generic Genome Browser (GBrowse). This in silico approach potentially identifies all paralogous sequences and so we colour‐code the significance of the mappings and offer an integrated, real‐time multiple alignment tool to partition them into paralogous groups. The MySQL database driving GBrowse can also be directly interrogated, using the powerful API offered by the Perl Bio::DB::GFF methods, facilitating a wide range of data‐mining possibilities. Copyright © 2005 John Wiley & Sons, Ltd.
The Korea Brassica Genome Project: A glimpse of the Brassica genome based on comparative genome analysis with Arabidopsis
Authors: Yang Tae‐Jin , Kim Jung‐Sun , Lim Ki‐Byung , Kwon Soo‐Jin , Kim Jin‐A , Jin Mina , Park Jee Young , Lim Myung‐Ho , Kim Ho‐Il , Kim Seog Hyung , Lim Yong Pyo , Park Beom‐Seok
Published: April 2005

A complete genome sequence provides unlimited information in the sequenced organism as well as in related taxa. According to the guidance of the Multinational Brassica Genome Project (MBGP), the Korea Brassica Genome Project (KBGP) is sequencing chromosome 1 (cytogenetically oriented chromosome #1) of Brassica rapa. We have selected 48 seed BACs on chromosome 1 using EST genetic markers and FISH analyses. Among them, 30 BAC clones have been sequenced and 18 are on the way. Comparative genome analyses of the EST sequences and sequenced BAC clones from Brassica chromosome 1 revealed their homeologous partner regions on the Arabidopsis genome and a syntenic comparative map between Brassica chromosome 1 and Arabidopsis chromosomes. In silico chromosome walking and clone validation have been successfully applied to extending sequence contigs based on the comparative map and BAC end sequences. In addition, we have defined the (peri)centromeric heterochromatin blocks with centromeric tandem repeats, rDNA and centromeric retrotransposons. In‐depth sequence analyses of five homeologous BAC clones and an Arabidopsis chromosomal region reveal overall co‐linearity, with 82% sequence similarity. The data indicate that the Brassica genome has undergone triplication and subsequent gene losses after the divergence of Arabidopsis and Brassica. Based on in‐depth comparative genome analyses, we propose a comparative genomics approach for conquering the Brassica genome. In 2005 we intend to construct an integrated physical map, including sequence information from 500 BAC clones and integration of fingerprinting data and end sequence data of more than 100 000 BAC clones. The sequences have been submitted to GenBank with accession numbers: 10 204 BAC ends of the KBrH library (CW978640–CW988843); KBrH138P04, AC155338; KBrH117N09, AC155337; KBrH097M21, AC155348; KBrH093K03, AC155347; KBrH081N08, AC155346; KBrH080L24, AC155345; KBrH077A05, AC155343; KBrH020D15, AC155340; KBrH015H17, AC155339; KBrH001H24, AC155335; KBrH080A08, AC155344; KBrH004D11, AC155341; KBrH117M18, AC146875; KBrH052O08, AC155342. Copyright © 2005 John Wiley & Sons, Ltd.
The Tomato Sequencing Project, the first cornerstone of the International Solanaceae Project (SOL)
Authors: Mueller Lukas A. , Tanksley Steven D. , Giovannoni Jim J. , van Eck Joyce , Stack Stephen , Choi Doil , Kim Byung Dong , Chen Mingsheng , Cheng Zhukuan , Li Chuanyou , Ling Hongqing , Xue Yongbiao , Seymour Graham , Bishop Gerard , Bryan Glenn , Sharma Rameshwar , Khurana Jiten , Tyagi Akhilesh , Chattopadhyay Debasis , Singh Nagendra K. , Stiekema Willem , Lindhout P. , Jesse Taco , Lankhorst Rene Klein , Bouzayen Mondher , Shibata Daisuke , Tabata Satoshi , Granell Antonio , Botella Miguel A. , Giuliano Giovanni , Frusciante Luigi , Causse Mathilde , Zamir Dani
Published: April 2005

The genome of tomato (Solanum lycopersicum) is being sequenced by an international consortium of 10 countries (Korea, China, the United Kingdom, India, The Netherlands, France, Japan, Spain, Italy and the United States) as part of a larger initiative called the ‘International Solanaceae Genome Project (SOL): Systems Approach to Diversity and Adaptation’. The goal of this grassroots initiative, launched in November 2003, is to establish a network of information, resources and scientists to ultimately tackle two of the most significant questions in plant biology and agriculture: (1) How can a common set of genes/proteins give rise to a wide range of morphologically and ecologically distinct organisms that occupy our planet? (2) How can a deeper understanding of the genetic basis of plant diversity be harnessed to better meet the needs of society in an environmentally friendly and sustainable manner? The Solanaceae and closely related species such as coffee, which are included in the scope of the SOL project, are ideally suited to address both of these questions. The first step of the SOL project is to use an ordered BAC approach to generate a high quality sequence for the euchromatic portions of the tomato as a reference for the Solanaceae. Due to the high level of macro and micro‐synteny in the Solanaceae the BAC‐by‐BAC tomato sequence will form the framework for shotgun sequencing of other species. The starting point for sequencing the genome is BACs anchored to the genetic map by overgo hybridization and AFLP technology. The overgos are derived from approximately 1500 markers from the tomato high density F2‐2000 genetic map (http://sgn.cornell.edu/). These seed BACs will be used as anchors from which to radiate the tiling path using BAC end sequence data. Annotation will be performed according to SOL project guidelines. All the information generated under the SOL umbrella will be made available in a comprehensive website. The information will be interlinked with the ultimate goal that the comparative biology of the Solanaceae—and beyond—achieves a context that will facilitate a systems biology approach. Copyright © 2005 John Wiley & Sons, Ltd.