bluuebunny/crossref_metadata_2025_split huggingface dataset:
Apparent conversion of adhesive resin in the hybrid layer, Part 1: Identification of an internal reference for Raman spectroscopy and the effects of water storage
Authors: Zou Yuan , Armstrong Steven R. , Jessop Julie L. P. 
Published: November 2007

AbstractMonomer conversion of adhesives in the hybrid layer is important to the quality and longevity of the dentin bond. In this study, degree of conversion and relative co‐monomer concentrations of both experimental and commercial adhesive resins were determined using Raman spectroscopy. The objectives were to identify stable Raman scattering peaks to use as internal references and to determine the effect of water storage on measured conversion and co‐monomer concentrations. The peak at 605 cm−1 did not change throughout polymerization and is associated with monomers in both adhesives. This peak was used as an internal reference for conversion and composition calculations before and after water storage. Conversion of the adhesive resins immediately after photopolymerization was ∼20% lower than that measured after 24‐h water storage. HEMA concentration (relative to bis‐GMA) in the adhesive resins immediately after photopolymerization was at least 5 wt % higher than that measured after 24‐h water storage. Elution of unreacted HEMA provides a reasonable explanation for the “supposed” change in conversion measurements, which is more appropriately described as apparent conversion. This apparent conversion will impact interpretation of physical properties and structure of the polymer, as well as increase the probability of water penetration and its reaction within the hybrid layer. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
A Nanoparticulate Drug‐Delivery System for Rivastigmine: Physico‐Chemical and in vitro Biological Characterization
Authors: Craparo Emanuela Fabiola , Pitarresi Giovanna , Bondì Maria Luisa , Casaletto Maria Pia , Licciardi Mariano , Giammona Gaetano 
Published: November 2007

AbstractThe preparation and characterization of surface‐PEGylated polymeric nanoparticles are described. These systems were obtained by UV irradiation of PHM and PHM‐PEG2000 as an inverse microemulsion, using an aqueous solution of the PHM/PHM‐PEG2000 copolymer mixture as the internal phase and triacetin saturated with water as the external phase, and characterized by dimensional analysis, zeta‐potential measurements and XPS. in vitro biological tests demonstrated their cell compatibility and their ability to escape from phagocytosis. Rivastigmine was encapsulated into the nanoparticle structure and drug‐release profiles from loaded samples were investigated in PBS at pH = 7.4 and human plasma.magnified image
Architecturally and Chemically Modified Poly(1,3‐cyclohexadiene)
Authors: Huang Tianzi , Zhou Hongliang , Hong Kunlun , Simonson J. Michael , Mays Jimmy W. 
Published: November 2007

AbstractStar‐shaped, star‐block‐linear, and hyperbranched poly(1,3‐cyclohexadiene) (PCHD) (co)polymers were synthesized through a convergent living anionic polymerization process or via addition of divinylbenzene. Chemical modification of star‐shaped PCHDs, including aromatization, hydrogenation, fluorination, and sulfonation, was carried out in order to manipulate the physical and thermal properties of these materials. The obtained (co)polymers were characterized by gel permeation chromatography, 1H NMR, DSC, and thermal gravimetric analysis in order to elucidate their molecular weights, molecular weight distributions, chemical nature, and physical and thermal properties. The synthetic approaches described herein offer routes to novel structure and functionality in PCHD‐based materials.magnified image
Computational design of multiaxial tests for anisotropic material characterization
Authors: Furukawa Tomonari , Michopoulos John G. 
Published: November 2007

AbstractAlthough anisotropic materials provide more capabilities for mission‐ and application‐tailored design and functional flexibility to final structures than regular isotropic materials, the directional behavior of the anisotropic materials further complicates their inelastic and damage behavior. Such a non‐linear behavior can be effectively observed and characterized by multiaxial testing, but how to design a multiaxial test for material characterization given a specimen remains an untouched issue. This paper presents a methodology that numerically designs the loading path of a multiaxial testing machine to characterize anisotropic materials. The multiaxial test must be able to exhibit quantities used to characterize materials as distinctly as possible. The proposed methodology formulates distinguishability and uniqueness as such quantities by first analyzing the specimen on a continuum basis with finite element method and then applying singular value decomposition. Associating the distinguishability and uniqueness with the informativeness of the loading path, the design problem is formulated such that an effective loading path can be found efficiently by a standard optimization method. Numerical examples first investigate the validity of the distinguishability and the uniqueness as performance measures to evaluate loading paths. The efficacy of the proposed methodology has been then confirmed by analyzing it with and applying it to design problems. Copyright © 2007 John Wiley & Sons, Ltd.
The “comonomer effect” in ethylene/α‐olefin copolymerization using homogeneous and silica‐supported Cp2ZrCl2/MAO catalyst systems: Some insights from the kinetics of polymerization, active center studies, and polymerization temperature
Authors: Awudza Johannes A. M. , Tait Peter J. T. 
Published: November 2007

AbstractHomogeneous and silica‐supported Cp2ZrCl2/methylaluminoxane (MAO) catalyst systems have been used for the copolymerization of ethylene with 1‐butene, 1‐hexene, 4‐methylpentene‐1 (4‐MP‐1), and 1‐octene in order to compare the “comonomer effect” obtained with a homogeneous metallocene‐based catalyst system with that obtained using a heterogenized form of the same metallocene‐based catalyst system. The results obtained indicated that at 70 °C there was general rate depression with the homogeneous catalyst system whereas rate enhancement occurred in all copolymerizations carried out with the silica‐supported catalyst system. Rate enhancement was observed for both the homogeneous and the silica‐supported catalyst systems when ethylene/4‐MP‐1 copolymerization was carried out at 50 °C. Active center studies during ethylene/4‐MP‐1 copolymerization indicated that the rate depression during copolymerization using the homogeneous catalyst system at 70 °C was due to a reduction in the active center concentration. However, the increase in polymerization rate when the silica‐supported catalyst system was used at the same temperature resulted from an increase in the propagation rate coefficient. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 267–277, 2008
New polymer organogelators with L‐isoleucine and L‐valine as a gelation‐causing segment: Organogelation by a combination of supramolecular polymer and conventional polymer
Authors: Suzuki Masahiro , Yanagida Ryosuke , Setoguchi Chiho , Shirai Hirofusa , Hanabusa Kenji 
Published: November 2007

AbstractNew polymer organogelators, which are composed of poly(ethylene glycol), poly(propylene glycol), and poly(dimethylsiloxane)s as a polymer segment and L‐isoleucine and L‐valine derivatives as a gelation‐causing segment, were synthesized, and their organogelation properties were examined in organic solvents and oils. These polymer organogelators formed organogels in many organic solvents and oils, and their gels were thermally stable and had a high mechanical strength. Furthermore, the effects of the polymer backbone on the organogelation is discussed using FTIR spectroscopy, field emission scanning electron microscope observation, and analysis of thermal stability and strength of the organogel. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 353–361, 2008
High molar mass ethene/1‐olefin copolymers synthesized with acenaphthyl substituted metallocene catalysts
Authors: Aitola Erkki , Hakala Kimmo , Byman‐Fagerholm Hedvig , Leskelä Markku , Repo Timo 
Published: November 2007

AbstractThe influence of ligand structure on copolymerization properties of metallocene catalysts was elucidated with three C1‐symmetric methylalumoxane (MAO) activated zirconocene dichlorides, ethylene(1‐(7, 9)‐diphenylcyclopenta‐[a]‐acenaphthadienyl‐2‐phenyl‐2‐cyclopentadienyl)ZrCl2 (1), ethylene(1‐(7, 9)‐diphenylcyclopenta‐[a]‐acenaphthadienyl‐2‐phenyl‐2‐fluorenyl)ZrCl2 (2), and ethylene(1‐(9)‐fluorenyl‐(R)1‐phenyl‐2‐(1‐indenyl)ZrCl2 (3). Polyethenes produced with 1/MAO had considerable, ca. 10% amount of trans‐vinylene end groups, resulting from the chain end isomerization prior to the chain termination. When ethene was copolymerized with 1‐hexene or 1‐hexadecene using 1/MAO, molar mass of the copolymers varied from high to moderate (531–116 kg/mol) depending on the comonomer feed. At 50% comonomer feed, ethene/1‐olefin copolymers with high hexene or hexadecene content (around 10%) were achievable. In the series of catalysts, polyethenes with highest molar mass, up to 985 kg/mol, were obtained with sterically most crowded 2/MAO, but the catalyst was only moderately active to copolymerize higher olefins. Catalyst 3/MAO produced polyethenes with extremely small amounts of trans‐vinylene end groups and relatively low molar mass 1‐hexene copolymers (from 157 to 38 kg/mol) with similar comonomer content as 1. These results indicate that the catalyst structure, which favors chain end isomerization, is also capable to produce high molar mass 1‐olefin copolymers with high comonomer content. In addition, an exceptionally strong synergetic effect of the comonomer on the polymerization activity was observed with catalyst 3/MAO. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 373–382, 2008
An experimental model for the measurement of inspired gas temperatures in ventilated neonates
Authors: Jardine Luke Anthony , Dunster Kimble Robert , Davies Mark William 
Published: November 2007

AbstractObjectiveTo determine the inspired gas temperature at points from the endo‐tracheal tube (ETT) circuit manifold to the tip of the ETT in a model neonatal lung.DesignA model lung attached to standard ventilator circuit, autofeed chamber and humidifier was ventilated using typical pressure‐limited, time cycled settings. Temperatures were measured at various distances along the ETT using a K‐type thermocouple temperature probe.ResultsThe inspired gas temperature dropped from the circuit temperature probe site (40°C) to the proximal end of the ETT (37°C). The temperature dropped further as it passed through the exposed part of the ETT (34°C) but then warmed again on entering the lung model so that the inspired gas at the distal end of the ETT was 37°C. Statistically significant differences were found with a one‐way ANOVA P‐value of <0.0001. The differences between each pair of mean temperatures were statistically significant (all P < 0.001) except when comparing the proximal end of the ETT with midway down the ETT (Bonferroni's Multiple Comparison Test, P > 0.05).ConclusionsInspired gas temperature drops as it passes through the circuit temperature probe site, the proximal end of the ETT and the exposed part of the ETT. The inspired gas rewarms on entering the model lung and exits the ETT at the desired temperature. The effect of measuring temperature closer to the patient, setting the circuit temperature higher and/or increasing the ambient temperature through which the circuit passes, need to be evaluated. Pediatr Pulmonol. 2008; 43:29–33. © 2007 Wiley‐Liss, Inc.
C‐reactive protein in children with obstructive sleep apnea and the effects of treatment
Authors: Li Albert M. , Chan Michael H.M. , Yin Jane , So Hung K. , Ng Siu K. , Chan Iris H.S. , Lam Christopher W.K. , Wing Yun K. , Ng Pak C. 
Published: November 2007

AbstractObjectiveTo evaluate C‐reactive protein (CRP) concentration in children with OSA and to determine the effects of treatment for OSA on its serum concentration.MethodsConsecutive children with habitual snoring and symptoms suggestive of OSA were recruited. They completed a sleep apnea symptom questionnaire, underwent physical examination and an overnight polysomnography (PSG). Fasting serum CRP and lipid profile were taken after overnight PSG. OSA was diagnosed if obstructive apnea index (OAI) > 1.ResultsOne hundred forty‐one children with a median (IQR) age of 10.8 (8.5–12.8) years were recruited. There were 96 boys and the commonest presenting symptoms were nocturnal mouth breathing, prone sleeping position and poor attention at school. Forty‐five children were found to have OSA and those with moderate disease (OAI > 5) had significantly higher CRP levels compared to their non‐OSA counterparts [1.3 (0.8–3.6) vs. 0.7 (0.2–2.0), P = 0.01]. Stepwise linear multiple regression analysis indicated that OAI was independently associated with CRP (β coefficient = 0.013, P = 0.001). Sixteen children underwent treatment and there was significant reduction in their serum CRP after intervention [pre vs. post‐CRP, 1.3 (0.6–4.1) vs. 0.4 (0.2–1.3), P = 0.033]. A significant correlation was also demonstrated between change in CRP and change in OAI (r = 0.593, P = 0.042) following treatment for OSA.ConclusionChildren with OSA may have associated systemic inflammation as reflected by a raised CRP that decreased significantly following treatment. Pediatr Pulmonol. 2008; 43:34–40. © 2007 Wiley‐Liss, Inc.
Abnormal results on a second testing and risk of gestational diabetes in women with normal baseline glucose levels
Authors: Boriboonhirunsarn Dittakarn , Sunsaneevithayakul Prasert 
Published: November 2007

AbstractObjectiveTo examine the rate of women with normal initial results to glucose tolerance tests who have abnormal results to subsequent testing, and estimate the risk of gestational diabetes mellitus (GDM) in these women.MethodsBaseline plasma glucose levels were classified as normal if they were less than 120 mg/dL (group 1) or between 120 and 139 mg/dL (group 2) by the 50‐g glucose challenge test (GCT); as abnormal if they were found abnormal by the 50‐g GCT but normal by the 100‐g glucose tolerance test (OGTT) (group 3); and as abnormal if 1 of the four 100‐g OGTT values was abnormal (group 4). A second testing session with the 50‐g GCT and 100‐g OGTT was performed between the 24th and 28th weeks of pregnancy for 900 women at risk whose initial test results were normal.ResultsOf the 823 women with normal baseline results who completed the study, 41.4% had abnormal results to the second 50‐g GCT, and gestational diabetes mellitus was diagnosed by the 100‐g OGTT in 7.0% of these 823 women. Compared with group 1, the women in groups 2, 3, and 4 were at a significantly increased risk of having an abnormal result to the second 50‐g GCT. They were also at a significantly increased risk for GDM. The adjusted odds ratios (ORs) were 3.0 for group 2 (95% confidence interval [CI], 1.2–7.2), 4.9 for group 3 (95% CI, 2.2–11.0), and 11.3 for group 4 (95% CI, 3.9–32.6).ConclusionThe risk of developing GDM significantly increased with increasing baseline plasma glucose levels by the 50‐g GCT.
Effects of flexible fiberoptic endoscopy on pharyngeal swallow physiology
Authors: Suiter Debra M. , Moorhead Mary Katherine 
Published: November 2007

ObjectiveThe purpose of this study was to determine if the presence of a flexible fiberoptic endoscope in the pharynx affects swallow physiology.Study DesignThis was a prospective cohort study.Subjects and MethodsFourteen individuals with normal swallow function, 23 to 83 years of age, completed a videofluo‐roscopic swallow study with and without a 3.5 mm flexible fiberoptic endoscope maintained in the “high” position, ie, below the velopharyngeal port and above the epiglottis. Each study was analyzed for three swallow duration measures, number of swallows necessary to clear the bolus, and penetration‐aspiration scale scores.ResultsNo significant (P > 0.05) main effects for condition were found for swallow duration, penetration‐aspiration scale scores and number of swallows to clear the bolus.ConclusionThe presence of a flexible fiberoptic endoscope in the pharynx during swallowing did not significantly affect pharyngeal swallow physiology in the patients studied, but we cannot exclude a false‐negative conclusion because of low statistical power.
THE ROLE OF FOREARM SKIN AND MUSCLE VESSELS IN REACTIVE HYPERAEMIA
Authors: Fewings JD , Hyman C , Walsh JA , Whelan RF 
Published: November 2007

SummaryThe response of forearm skin and muscle vessels to periods of circulatory arrest of 1–10 min. duration has been assessed the technique of superficial and deep venous blood oxygen saturation estimations in 11 experiments on 5 subjects. In every case periods of circulatory arrest were followed by a compictious hyperaemia (rise in oxygen saturation) in both skin and muscle vessels, the response being more marked with longer durations of ischaemia. Corroborative evidence was obtained from 3 experiments in which an increased clearance of a radio‐isotope (NaI131) from forearm skin was observed during reactive hyperaemia. It is concluded that both skin and muscle vessels of the forearm are involved in the phenomenon of reactive hyperaemia.
ENHANCING EFFECT OF DEAE‐DEXTRAN ON INCLUSION COUNTS OF AN OVINE CHLAMYDIA (BEDSONIA) IN CELL CULTURE
Authors: Harrison Marcaret J 
Published: November 2007

SummaryPretreatment of HEp2 cells with DEAE‐Dextran increased significantly the number of inclusions formed following inoculation with an ovine agent of the Chlamydia group of micro‐organisms. A fivefold increase occurred when the DEAE‐Dextran was washed off before inoculation with the agent and if the DEAE‐Dextran was poured off without washing a twentyfold increase was obtained.
IN VITRO STUDIES OF THE FACTORS AFFECTING THE METABOLISM OF COBAMIDES AND COBINAMIDES BY SHEEP RUMEN MICRO‐ORGANISMS
Authors: Gawthohne JM 
Published: November 2007

SummaryAn in vitro system was used to investigate the factors affecting the metabolism of cobamides and cobinamides in sheep rumen micro‐organisms.Cobalt was the primary limiting factor for the synthesis of cobamides and cobinamides in the rumen contents of sheep fed cobalt dificient rations. The vitamin B12‐activity of rumen contents from such sheep increased within two hours of cobalt addition. This rise in vitamin B12‐activity was due to an increased synthesis of 2‐methyladenyl cobamide and 5,6‐dimethylbenzimidazolyl cobamides. Other cobamides and cobinamides appeared after five hours.The addition of nitrogen bases did not affect the total rate of synthesis of cobamides in sheep rumen contents. However, in the presence of adequate cobalt the addition of certain nitrogen bases stimulated the synthesis of the corresponding cobamide at the expense of other cobamides.Rumen micro‐organisms did not synthesis significant amounts of cobamides from exogenous cobinamides. When cobinamide was added to rumen contents it was apparently converted to compounds which do not have vitamin B12‐ activity for E. coli 113–3.
AN IMPROVED CALLIPHORA BIOASSAY FOR INSECT MOULTING HORMONES
Authors: Thomson JA , Imray F Paula , Hohn DHS 
Published: November 2007

SummaryThe bioassay of insect moulting hormones is facilitated by use of the Australian brown blowfly, Calliphora stygia, instead of C. vicina, the species commonly employed. The late larval development of C. stygia is more readily synchronized than that of C. vicina, and the necessary treatment is described. With C. stygia, the yield of test‐abdomens for use in the bioassay is 60–80% when larvae are kept at an elevated oxygen tension after ligation. The best yield of test‐abdomens obtained with C. vicina is approximately 40%, whether the larvae are kept in air or in oxygen.Dose‐response data for crustecdysone administered to test‐abdomens of C. stygia and C. vicina are presented. Sensitivity of tbe bioassay depends in part on the Volume of test solution injected. The useful dose‐range for the moulting hormones bioassay in C. stygia corresponds to approximately 10–75 ng. crustecdysone/abdomen. In C. vicina the useful range is the equivalent of approximately 5–50 ng. crustecdysone/abdomen.
THE ROLE OF THE KIDNEY IN ALBUMIN, TRANSFERRIN AND IgG CATABOLISM IN THE RAT
Authors: Seward Judith‐Mary , Morgan EH 
Published: November 2007

SummaryRat albumin, transferrin and IgG‐globulin labelled with radioactive iodine were injected intravenously into male rats, and the changes in plasma protein‐bound radioactivity were measured both before and after bilateral nephrectomy or laparotomy performed 96 hours after the injections. The rates of catabolism of all three proteins as assessed from the fall in plasma concentration of labelled protein decreased to a similar degree after both types of operation. Because of the changes in plasma concentration and pool sizes of the proteins after the operations, it was not possible to accurately measure the effect of nephrectomy on catabolism. However, the similarity of results with the two types of operations indicated that the kidney played no more than a relatively small part in catabolism of the proteins.
PERIPHERAL VASCULAR REACTIVITY TO ANGIOTENSIN AND NORADRENALINE IN PREGNANT AND NON‐PREGNANT WOMEN
Authors: Lumbers Eugenie R 
Published: November 2007

SummaryThe hand vascular sensitivity to angiotensin is reduced in pregnant women as compared to non‐pregnant women. Since the hand vasculature retains a normal response to noradrenaline in pregnant women, this reduction in sensitivity to angiotensin is selective.Furthermore, the reduction in sensitivity to the pressor response to angiotensin seen in pregnant women must, in part, be due to a reduction in peripheral vascular sensitivity.Elevations in plasma renin activity, renin concentration and renin substrate level are associated with the reduction in sensitivity to angiotensin observed.
THE IN VIVO CARBON DIOXIDE TITRATION CURVE IN MAN DURING REBREATHINC
Authors: Despas PJ , Leigh J 
Published: November 2007

SummaryThe in vivo titration curve of CO2 measured in five subjects during rebreathing of 7% CO2 in O2 for 3 minutes was not significantly different from the corresponding in vitro titration curve measured on arterial blood from each subject. The buffering of CO2 m vivo when measured by other methods is known to be less than it is in vitro. CO2 in vivo is thought to equilibrate with a well buffered compartment (intravascular) and a poorly buffered compartment (interstitial fluid). It has been suggested that HCO3—shift takes place from the intravascular compartment. During rebreathing there may be insufficient time for HCO3—shift to occur. This would explain the identical CO2 titration curves in vivo and in vitro shown by this study.
THE RESPONSE OF HAND BLOOD FLOW TO DISTANT ICE APPLICATION
Authors: Jamieson GG , Ludbrook J , Wilson A 
Published: November 2007

SummaryThe reflex effect of applying ice to the neck on hand blood flow has been examined in normal and synipathectomised subjects. Within and among normal subjects the magnitude and time‐course of the response is reproducile. There was no difference in response between cool and warm hands.