bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compositional and Weave Pattern Analyses of Glass Fibers in Dental Polymer Fiber Composites
Authors: Vallittu Pekka K. 
Published: March 2005

Purpose This study compared weave patterns and glass compositions of five glass fiber materials found in commercial fiber‐reinforced dental composites.Materials and Methods A scanning electron microscope (SEM) was used to investigate the woven structure of five glass fiber products, and an energy‐dispersive x‐ray spectrometer (SEM/EDS) was used to determine the elemental composition of these glass fibers in the bulk and at the surface of the fiber. Five fibers of each product were analyzed.Results The fiber products were either unidirectional rovings or bidirectional weaves. More precisely, the woven structures were linen weave, twill weave, or twill weave ribbon. SEM/EDS analysis revealed that the composition of the glass fibers was typical for E (electrical)‐glass fibers with one exception. One product intended for use in fixed prosthodontics included unidirectional fibers with a composition consistent with a modified high‐tensile‐strength R‐glass. Boron oxide found on the surface of glass fibers would likely contribute to an increased potential for corrosion of fiber‐reinforced composite.Conclusions The predominant fiber composition in these products is E‐glass. Because the degree of hydrolytic stability of polymer‐fiber composites over time may lead to material failure in permanent restorations, this property should be investigated further.
Survey of Educationally Qualified and Board‐Eligible Prosthodontists on the Board‐Certification Process
Authors: Nimmo Arthur , Taylor Thomas D. 
Published: March 2005

Purpose A survey of prosthodontists who have not achieved diplomate status from the American Board of Prosthodontics was conducted to identify the reasons why they have or have not pursued and/or achieved board certification in prosthodontics.Materials and Methods A survey was sent to 500 educationally qualified or board‐eligible prosthodontists in the summer of 1997. A total of 364 responses were received, for a response rate of 73%. The responses and comments were analyzed.Results The majority of respondents listed private practice as their primary area of professional activity. Personal accomplishment was cited by 80% of the respondents as a major motivational factor. Three major impediments to taking the examination included: time away from practice (65%), time away from family (59%), and financial sacrifice (57%). More than one third of the respondents believed there was no advantage to attempting the board examination. Less than half of the respondents have attended The American College of Prosthodontists (ACP)‐sponsored Board Preparation Course, and half have used the ACP Study Guide. The respondents have perceived these to be useful in their preparation efforts. The survey presented four potential changes in the exam format that might encourage greater participation in the board‐certification process. Respondents showed the greatest support (64%) for the concept of a written examination only (ie, elimination of Parts 2, 3, and 4).Conclusions Personal accomplishment was the most important motivational factor in starting the examination process. The greatest impediments to pursuing board certification were the time involved and financial resources expended. The greatest interest in a potential change in the examination format was the use of a written examination only.
Reinforcement of Denture Base Resin with Glass Fillers
Authors: Marei MScD Mona K., BDS 
Published: March 2005

PurposeThis study evaluated the effect of short glass fibers on the transverse strength of a heat‐polymerized acrylic resin denture base material.Materials and MethodsFour groups of specimens (n = 10) were fabricated according to the ISO standard for the transverse strength test. E‐glass fibers were triturated to produce short fibers of different lengths. Specimens for Group 1 (control) were made of unfilled polymethylmethacrylate (PMMA). For group 2, the PMMA powder was modified with 0.1 g of dry glass fibers. For group 3, the PMMA powder was modified with 0.1 g of silanized glass fibers. For group 4, the PMMA powder was modified with 0.2 g of silanized glass fibers. A three‐point loading test was used to determine the transverse strength of the tested specimens. The fracture surface of each specimen was evaluated using SEM.ResultsThe addition of untreated glass fibers increased the transverse strength by 11% but produced some porosity in the polymeric matrix. The addition of silane‐treated glass fibers increased the transverse strength of PMMA by 28% for group 3 and by 26% for group 4, and produced a dense structure for the polymer‐fiber composite.ConclusionThe transverse strength of PMMA can be slightly increased by the addition of short glass fibers.
Phylogenomic approaches to common problems encountered in the analysis of low copy repeats: The sulfotransferase 1A gene family example
Authors: Bradley Michael E , Benner Steven A 
Published: March 2005

Abstract
Background
Blocks of duplicated genomic DNA sequence longer than 1000 base pairs are known as low copy repeats (LCRs). Identified by their sequence similarity, LCRs are abundant in the human genome, and are interesting because they may represent recent adaptive events, or potential future adaptive opportunities within the human lineage. Sequence analysis tools are needed, however, to decide whether these interpretations are likely, whether a particular set of LCRs represents nearly neutral drift creating junk DNA, or whether the appearance of LCRs reflects assembly error. Here we investigate an LCR family containing the sulfotransferase (SULT) 1A genes involved in drug metabolism, cancer, hormone regulation, and neurotransmitter biology as a first step for defining the problems that those tools must manage.

Results
Sequence analysis here identified a fourth sulfotransferase gene, which may be transcriptionally active, located on human chromosome 16. Four regions of genomic sequence containing the four human SULT1A paralogs defined a new LCR family. The stem hominoid SULT1A progenitor locus was identified by comparative genomics involving complete human and rodent genomes, and a draft chimpanzee genome. SULT1A expansion in hominoid genomes was followed by positive selection acting on specific protein sites. This episode of adaptive evolution appears to be responsible for the dopamine sulfonation function of some SULT enzymes. Each of the conclusions that this bioinformatic analysis generated using data that has uncertain reliability (such as that from the chimpanzee genome sequencing project) has been confirmed experimentally or by a "finished" chromosome 16 assembly, both of which were published after the submission of this manuscript.

Conclusion
SULT1A genes expanded from one to four copies in hominoids during intra-chromosomal LCR duplications, including (apparently) one after the divergence of chimpanzees and humans. Thus, LCRs may provide a means for amplifying genes (and other genetic elements) that are adaptively useful. Being located on and among LCRs, however, could make the human SULT1A genes susceptible to further duplications or deletions resulting in 'genomic diseases' for some individuals. Pharmacogenomic studies of SULT1Asingle nucleotide polymorphisms, therefore, should also consider examining SULT1A copy number variability when searching for genotype-phenotype associations. The latest duplication is, however, only a substantiated hypothesis; an alternative explanation, disfavored by the majority of evidence, is that the duplication is an artifact of incorrect genome assembly.
Molecular Changes in Tamoxifen-Resistant Breast Cancer: Relationship Between Estrogen Receptor, HER-2, and p38 Mitogen-Activated Protein Kinase
Authors: Gutierrez M. Carolina , Detre Simone , Johnston Stephen , Mohsin Syed K. , Shou Jiang , Allred D. Craig , Schiff Rachel , Osborne C. Kent , Dowsett Mitch 
Published: March 2005

Purpose To evaluate growth factor receptor cross talk with the estrogen receptor (ER) in paired clinical breast cancer specimens and in a xenograft model before tamoxifen and at tumor progression as a possible mechanism for tamoxifen resistance. Methods Specimen pairs from 39 patients were tissue arrayed and stained for ER, progesterone receptor (PgR), Bcl-2, c-ErbB2 (HER-2), and phosphorylated (p) p38 mitogen-activated protein kinase (MAPK), p-ERK1/2 MAPK, and p-Akt. Xenograft MCF-7 tumors before and after tamoxifen resistance were assessed for levels of p-p38. Results Pretreatment, there were strong correlations between ER, PgR, and Bcl-2, and an inverse correlation between ER and HER-2. These correlations were lost in the tamoxifen- resistant tumors and replaced by strong correlations between ER and p-p38 and p-ERK. ER expression was lost in 17% of resistant tumors. Three (11%) of the 26 tumors originally negative for HER-2 became amplified and/or overexpressed at resistance. All ER-positive tumors that overexpressed HER-2 originally or at resistance expressed high levels of p-p38. In the pretreatment and tamoxifen-resistant specimens, there were strong correlations between p-p38 and p-ERK. In the tamoxifen-resistant xenograft tumors, like the clinical samples, there was a striking increase in p-p38. Conclusion The molecular pathways driving tumor growth can change as the tumor progresses. Crosstalk between ER, HER-2, p38, and ERK may contribute to tamoxifen resistance and may provide molecular targets to overcome this resistance.
Deleterious effects of repeated cold exposure in a freeze-tolerant sub-Antarctic caterpillar
Authors: Sinclair Brent J. , Chown Steven L. 
Published: March 2005

SUMMARYMultiple freeze–thaw cycles are common in alpine, polar and temperate habitats. We investigated the effects of five consecutive cycles of approx.–5°C on the freeze-tolerant larvae of Pringleophaga marioniViette (Lepidoptera: Tineidae) on sub-Antarctic Marion Island. The likelihood of freezing was positively correlated with body mass, and decreased from 70%of caterpillars that froze on initial exposure to 55% of caterpillars that froze on subsequent exposures; however, caterpillars retained their freeze tolerance and did not appear to switch to a freeze-avoiding strategy. Apart from an increase in gut water, there was no difference in body composition of caterpillars frozen 0 to 5 times, suggesting that the observed effects were not due to freezing, but rather to exposure to cold per se. Repeated cold exposure did not result in mortality, but led to decreased mass, largely accounted for by a decreased gut mass caused by cessation of feeding by caterpillars. Treatment caterpillars had fragile guts with increased lipid content, suggesting damage to the gut epithelium. These effects persisted for 5 days after the final exposure to cold, and after 30 days, treatment caterpillars had regained their pre-exposure mass, whereas their control counterparts had significantly gained mass. We show that repeated cold exposure does occur in the field, and suggest that this may be responsible for the long life cycle in P. marioni. Although mean temperatures are increasing on Marion Island, several climate change scenarios predict an increase in exposures to sub-zero temperatures, which would result in an increased generation time for P. marioni. Coupled with increased predation from introduced house mice on Marion Island, this could have severe consequences for the P. marioni population.
Estimation of the hindered settling function R(ϕ) from batch‐settling tests
Authors: Lester Daniel R. , Usher Shane P. , Scales Peter J. 
Published: March 2005

AbstractThe hindered settling function R(ϕ) is a material function that quantifies the interphase drag of colloidal suspensions for all solids volume fractions ϕ. A method is presented to estimate R(ϕ) from batch‐settling tests for solids volume fractions between the initial solids volume fraction, ϕ0, and the solids volume fraction at which the suspension forms a continuously networked structure, ϕg, known as the gel point. The method is based on an analytic solution of the associated inverse problem. Techniques are presented to address initialization mechanics observed in such tests as well as experimental noise and discrete data. Analysis of synthetic and experimental data suggests that accurate estimates of R(ϕ) are possible in most cases. These results provide scope for characterization of suspension dewaterability from batch‐settling tests alone. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Experimentally measured shear stress in the standpipe of a circulating fluidized bed
Authors: Sarra Angela , Miller Aubrey L. , Shadle Lawrence J. 
Published: March 2005

AbstractShear stress measurements were obtained in the standpipe of a circulating fluidized bed (CFB) for 230‐μm coke breeze particles under a variety of flow conditions. These data were combined with incremental gas‐phase pressure drop readings, and an estimate of the bed weight to predict the solids‐phase pressure drop. It was determined that the wall shear stress and solids‐phase pressure drop are significant portions of the momentum balance and cannot be neglected when modeling frictional flow behavior of Geldart type B powders in a standpipe using the conservation of linear momentum. The combined magnitude of the axial solids‐phase pressure drop and wall shear stress exceeded 48% of the total forces in the mixture momentum balance for a standpipe. However, tests indicated that the influence of the wall shear stress and axial solids pressure in the mixture momentum balance may be assumed to be negligible once minimum fluidization has been exceeded. Under packed standpipe flow conditions most literature applications treat the wall shear stress as being directly proportional to the axial solids pressure divided by a proportionality factor that does not change with solids flow rate. This assumed constant is the product of the Janssen coefficient and coefficient of friction or the stress ratio. However, shear stress measurements indicated that this proportionality factor experienced a large monotonic decrease from conditions of incipient flow, where it was at its maximum, to conditions of high volumetric fluxes, where it approached a much smaller constant value. Two packed‐bed flow regimes were identified. They are the smooth flow regime, characterized as spanning from moderate to large solid volumetric flow rates, and a stick‐slip regime characterized as spanning from incipient to moderate solid volumetric fluxes. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Syntheses of novel silylsubstituted distannanes
Authors: Fischer Roland , Schollmeier Thorsten , Schürmann Markus , Uhlig Frank 
Published: March 2005

AbstractStarting from diorganodichlorostannanes, a series of novel bis(triorganosilyl)‐stannanes and ‐distannanes has been prepared either by one‐pot reactions via Wurtz‐type coupling reactions with magnesium or lithium and triorganochlorostannanes, or by salt elimination reactions from triorganosilyllithium and diorganodichlorostannanes. A convenient and remarkably straightforward method is the oxidative coupling of potassium stannides with 1,2‐dibromoethane. Isolable intermediates and products were characterized by multinuclear magnetic resonance spectroscopy. In order to prove the constitution of a distannane, an X‐ray crystal structure analysis was performed. Copyright © 2005 John Wiley & Sons, Ltd.
Adsorption characteristics of tributyltin on municipal solid waste compost
Authors: Said‐Pullicino Daniel , Vella Alfred J. 
Published: March 2005

AbstractThe sorption behaviour of tributyltin (TBT) from reconstituted seawater onto municipal solid waste (MSW) compost was investigated to give first insights into the equilibrium and kinetic behaviour of this process. The rate of adsorption, the influence of pH, and the adsorbate hydrophobicity on the partitioning process were investigated. Adsorption kinetics indicated an initial fast rate of adsorption of TBT followed by a slower rate. The similarity of Freundlich sorption and desorption coefficients for TBT showed that the sorption process is also reversible, similar to that for the adsorption of TBT onto marine sediments. It was found that the adsorption capacity for TBT onto compost was highest at pH 6.7, and for other organotins it increased with increasing adsorbate hydrophobicity, following the trend tripropyltin < TBT < tripentyltin. The use of washed MSW compost as a sorbent for the purification of TBT‐contaminated wash waters as generated in large quantities during hull cleaning in dry docks is suggested as a mitigatory measure against pollution of the marine environment by TBT. Calculations suggest that modest amounts of compost will likely be required to treat the contaminated wastewaters generated from the Malta dry docks if a multiple batch system is adopted. Copyright © 2005 John Wiley & Sons, Ltd.
Pyridalyl, a novel insecticide: Potency and insecticidal selectivity
Authors: Isayama S. , Saito S. , Kuroda K. , Umeda K. , Kasamatsu K. 
Published: March 2005

AbstractPyridalyl is an insecticide of a novel chemical class (unclassified insecticides). Toxicity of pyridalyl to two insect pest species, Spodoptera litura and Frankliniella occidentalis, an insect predator, Orius stringicollis, and a pollinator, Bombus terrestris, was evaluated in the laboratory. The insecticidal activity of pyridalyl against S. litura was evaluated using the leaf‐dipping method. The potency of pyridalyl was highly effective against all development stages (2nd to 6th instar larvae) of S. litura. This compound was also evaluated against F. occidentalis using the direct spray method. For F. occidentalis, toxicity of pyridalyl was almost similar to that of acrinathrin, but greater than acrinathrin for adults. Then the toxicity of this product to the natural enemies, Orius stringicollis and the pollinating insect Bombus terrestris, was evaluated using the body‐dipping method or direct spray method. No acute toxicity of this product was observed on these non‐target insects. Moreover, the influence of pyridalyl to the nest of Bombus terrestris was evaluated using the direct spray to the inside of the nest. No apparent influence of this compound was observed by 21 days after treatment. The cytotoxicity of pyridalyl to the Sf9 insect cell line and the CHO‐K1 mammalian cell line was evaluated using the trypan‐blue exclusion method. High toxicity to the insect cell line, but almost no toxicity to the mammalian cell line, was observed. Thus, pyridalyl exhibited high selectivity in cytotoxicity between the insect and mammalian cell line as well as in insecticidal activity among insect species. We infer pyridalyl may be useful for IPM programs of greenhouse cultivation system. Arch. Insect Biochem. Physiol. 58:226–233, 2005. © 2005 Wiley‐Liss, Inc.
The role of vegetable and fruit consumption in the aetiology of squamous cell carcinoma of the oesophagus: A case‐control study in Uruguay
Authors: De Stefani Eduardo , Boffetta Paolo , Deneo‐Pellegrini Hugo , Ronco Alvaro L. , Correa Pelayo , Mendilaharsu María 
Published: March 2005

AbstractThere is strong evidence of a protection of high consumption of plant foods against squamous cell carcinoma of the oesophagus, but the respective role of fruits and vegetables is not well elucidated. In the time period 1996–2003, a case‐control study designed in order to address this question was conducted in Uruguay. The study included 200 cases and 400 age‐ and sex‐matched controls. High total vegetable and total fruit consumption was the strongest protective food group for this malignancy (OR 0.31, 95% CI 0.18–0.51). When this food group was dissected in total vegetables and total fruits, the latter item was more protective than the former one (OR for total fruits 0.48, 95% CI 0.35–0.66) (p‐value for difference between both variables 0.04). Finally, when total fruits were dissected in citrus fruits and other fruits, citrus fruits were strongly associated with a reduction in risk (OR 0.47, 95% CI 0.34–0.67). The results of our study point towards an important role of fruits in the prevention of squamous cell carcinoma of the oesophagus. © 2005 Wiley‐Liss, Inc.
Low level, long‐term inorganic arsenite exposure causes generalized resistance to apoptosis in cultured human keratinocytes: Potential role in skin co‐carcinogenesis
Authors: Pi Jingbo , He Yuying , Bortner Carl , Huang Jianli , Liu Jie , Zhou Tong , Qu Wei , North Susan L. , Kasprzak Kazimierz S. , Diwan Bhalchandra A. , Chignell Colin F. , Waalkes Michael P. 
Published: March 2005

AbstractInorganic arsenic is a human carcinogen that targets the skin. Carcinogenesis is a multistep process in which acquired apoptotic resistance is a common event and prior work in non‐skin cells shows acquired resistance to apoptosis occurs with chronic arsenite exposure. In the present study, when HaCaT cells, an immortalized, non‐tumorigenic human keratinocyte cell line, were continuously exposed to low‐level inorganic arsenite (as sodium arsenite; 100 nM) for 28 weeks, the cells acquired a generalized resistance to apoptosis. This included resistance to apoptosis induced by acute high concentrations of arsenite, ultraviolet A (UVA) irradiation, and several chemotherapeutic compounds (cisplatin, etoposide and doxorubicin). These arsenite‐tolerant (As‐TL) cells showed similar levels of UVA‐induced reactive oxygen species (ROS) and oxidative DNA damage when compared to passage match control cells. Because cellular apoptosis is dependent on the balance between proapoptotic and survival pathways, the roles of protein kinase B (PKB), a key antiapoptotic molecule, in this acquired apoptotic resistance were investigated. Stimulation of apoptosis markedly decreased nuclear phosphorylated PKB (P‐PKB) levels in control cells, but As‐TL cells showed greatly increased stability of nuclear P‐PKB. Pretreatment of the As‐TL cells with LY294002 or Wortmannin, which specifically inhibit PKB phosphorylation, completely blocked apoptotic resistance in As‐TL cells, indicating acquired apoptotic resistance is associated with increased stability of nuclear P‐PKB. Because arsenic and UV irradiation are co‐carcinogenic in mouse skin, resistance to UV‐induced apoptosis in As‐TL cells may allow UV‐damaged cells to escape normal cell population controls and initiate the carcinogenic cascade. The observation that As‐TL cells show no lessening of UV‐induced genotoxicity supports this possibility. © 2005 Wiley‐Liss, Inc.
Vascular and nonvascular complications of renal transplants: Sonographic evaluation and correlation with other imaging modalities, surgery, and pathology
Authors: Friedewald Sarah M. , Molmenti Ernesto P. , Friedewald John J. , DeJong Marius R. , Hamper Ulrike M. 
Published: March 2005

AbstractCadaveric or living donor renal transplantation is commonly performed in individuals with end‐stage renal disease. In recent years, gray‐scale sonography, coupled with color Doppler sonography (CDUS), power Doppler sonography (PDUS), or spectral Doppler sonography, has become the primary imaging modality for these patients. Postoperative serial sonography is performed to detect complications and aid in posttransplant management. In addition, sonography is used to guide percutaneous aspiration of fluid or biopsy to diagnose rejection or renal and perirenal masses.In this article we discuss the spectrum of sonographic findings, both vascular and nonvascular, of renal transplant complications, including but not limited to renal arterial and venous stenosis and thrombosis, peritransplant collections (lymphoceles, hematomas, urinomas, and seromas), posttransplant lymphoproliferative disorder, and postbiopsy complications (hematomas, pseudoaneurysms, and arteriovenous fistulas). We correlate sonographic findings with those from other imaging modalities (such as angiography, CT, and MRI) and findings at surgery and pathology when possible.