bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorinated polyimide nanocomposites for CO2/CH4 separation
Authors: Rubal Michael , Wilkins Cletus W. , Cassidy Patrick E. , Lansford Chris , Yamada Yasuharu 
Published: March 2008

AbstractThe purpose of this project was to synthesize fluorinated polyimide (PI) nanocomposite membranes in order to study the gas permeation rates and selectivity of carbon dioxide and methane. PIs were synthesized from 2,2‐bis(3,4‐anhydrodicarboxyphenyl)hexafluoropropane (6F dianhydride, 6FDA) and 4,4′‐diaminodiphenyl ether (oxydianiline, ODA) into which were incorporated nanoparticulate additives as follows: in situ TiO2, both plain and treated with dodecyl sulfate surfactant, and organo‐clay (Cloisite®‐10 Å) at loads of 1, 3, and 5 wt% to the polyamic acid. Polyamic acid films were solvent cast, cured at 200°C then post‐cured at 300°C and measured for permeation data and for thermal properties. Glass transition temperatures ranged from 124 to 140°C for the cured PIs and from 142 to 147°C for the post‐cured materials, the nano‐inclusions having little discernable effect on this property. Thermogravimetric analysis (TGA) data show that the inclusion of Cloisite® or TiO2 caused a small decrease of thermal stability from 555°C to about 532 to 541°C. The inclusion of clay causes a decreased permeation rate while the addition of TiO2 improves the rate and selectivity. Treating the nanofillers with surfactant decreases selectivity and marginally increases rate of permeation of CO2. Post‐curing caused a darkening of the composites, but not the neat PI. This heat treatment also resulted in a significantly decreased permeation rate, but a significantly increased selectivity. The resulting material shows superior gas separation properties to the commercially available PI, Matrimid® produced by Ciba‐Geigy. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of rubber type on the curing and physical properties of silica filled rubber compounds
Authors: Shin Chung Ho , Kim Dae Su 
Published: March 2008

AbstractAs environmental regulations are getting stricter, tire industries for automobiles have shown much interest in substituting silica for conventional carbon black partially or entirely. To take full advantage of silica as fillers for rubbers, it is essential to find a reasonable rubber system that shows an excellent performance with silica reinforcement. Therefore, in this study, several different rubber compounds comprising the same amount of silica were prepared with several different rubber systems, respectively. The processability, curing characteristics, and mechanical and viscoelastic properties of the rubber compounds were investigated to analyze the performance of the rubber compounds as tire tread materials. Among the rubber compounds studied, SBR1721 compound comprising natural rubber (NR) and styrene butadiene rubber (SBR) with high styrene content was considered the most appropriate for application to tire tread materials. Copyright © 2008 John Wiley & Sons, Ltd.
Poly(N‐isopropylacrylamide)‐based comb‐type grafted hydrogel with rapid response to blood glucose concentration change at physiological temperature
Authors: Zhang Shi‐Bo , Chu Liang‐Yin , Xu Dan , Zhang Jie , Ju Xiao‐Jie , Xie Rui 
Published: March 2008

AbstractA new type of glucose‐responsive hydrogel with rapid response to blood glucose concentration change at physiological temperature has been successfully developed. The polymeric hydrogel contains phenylboronic acid (PBA) groups as glucose sensors and thermo‐responsive poly (N‐isopropylacrylamide) (PNIPAM) groups as actuators. The response rate of the hydrogel to environmental glucose concentration change was significantly enhanced by introducing grafted poly(N‐isopropylacrylamide‐co‐3‐acrylamidophenylboronic acid) [poly(NIPAM‐co‐AAPBA)] side chains onto crosslinked poly(NIPAM‐co‐AAPBA) networks for the first time. The synthesized comb‐type grafted poly(NIPAM‐co‐AAPBA) hydrogels showed satisfactory equilibrium glucose‐responsive properties, and exhibited much faster response rate to glucose concentration change than normal type crosslinked poly(NIPAM‐co‐AAPBA) hydrogels at physiological temperature. Such glucose‐responsive hydrogels with rapid response rate are highly attractive in the fields of developing glucose‐responsive sensors and self‐regulated drug delivery systems. Copyright © 2008 John Wiley & Sons, Ltd.
Spironolactone and gastrointestinal bleeding: a population based study
Authors: Russo Antonio , Autelitano Mariangela , Bisanti Luigi 
Published: March 2008

AbstractBackgroundSeveral medical reports showed an increased risk of stomach and duodenum bleeding associated with the use of spironolactone. The objective of this work is to examine the association between upper gastrointestinal (UGI) bleeding and exposure to spironolactone, using a population‐based cohort design.MethodsUsing the pharmaceutical prescriptions from 2000 to 2006, a cohort was identified of residents in Milan (Italy) with chronic exposure to spironolactone or other diuretic drugs. The main outcome was defined as the hospital admission for UGI bleeding or ulcers. To control for potential bias related to spironolactone use, the propensity score was estimated. Then, each patient treated with spironolactone was randomly matched with one treated with other diuretics and having the same propensity score using the caliper matching method. Proportional hazard models were fitted by computing hazard ratios (HR) and the corresponding 95% confidence intervals (95%CI).ResultsA total of 53 550 unexposed and 10 564 exposed to spironolactone were identified. Overall in the study period, 174 patients (3.2%) developed UGI bleeding in the unexposed and 51 (4.8%) in the exposed group. HR for UGI bleeding for the spironolactone exposed group was 1.94 (95%CI 1.42–2.65).The sensitivity analysis based on the matched design using the propensity score showed a statistically significant twofold increase of gastrointestinal bleeding only among subjects exposed to high spironolactone dose (HR 2.50; 95%CI 1.08–5.79).ConclusionsResults from a large population based study confirm that spironolactone increases the risk of UGI bleeding. Copyright © 2008 John Wiley & Sons, Ltd.
Specificity of immobilized porcine pepsin in H/D exchange compatible conditions
Authors: Hamuro Yoshitomo , Coales Stephen J. , Molnar Kathleen S. , Tuske Steven J. , Morrow Jeffrey A. 
Published: March 2008

AbstractStatistical analysis of data from 39 proteins (13 766 amino acid residues) digested with immobilized porcine pepsin under conditions compatible with hydrogen/deuterium (H/D) exchange (<1°C, <30 s) was performed to examine pepsin cleavage specificity. The cleavage of pepsin was most influenced by the amino acid residue at position P1. Phe and Leu are favored residues each with a cleavage probability greater than 40%. His, Lys, Arg, or Pro residues prohibit cleavage when found at the P1 position. Pro also cannot be at position P2 (cleavage probability <0.3%). Occupation of the P3 position by His, Lys, or Arg, or occupation of the P2′ position by Pro, also leads to very little cleavage (cleavage probability <1.7%). The average cleavage probability over the entire data set was 13.6%, which is slightly lower than the value previously obtained by Powers et al. (14.8%). This is due, in part, to the larger protein sizes used in the current study. While the specificity of pepsin was similar to that previously observed, higher selectivity was observed in the present study due to less experimental variation in the conditions used to generate our database. Copyright © 2008 John Wiley & Sons, Ltd.
Short‐phase training on a virtual reality simulator improves technical performance in tele‐robotic surgery
Authors: Balasundaram Indran , Aggarwal Rajesh , Darzi Ara 
Published: March 2008

AbstractBackgroundThe da Vinci tele‐robot necessitates the acquisition of new skills and surgical educators must develop standardized training programmes. It is possible that virtual reality (VR) computer simulation maybe used and it is necessary to define whether a simulator is an appropriate tool.MethodsTen surgical novices performed a series of five tasks, ten times on a commercially available VR robotic simulator. Two experts repeated the series of tasks twice in an attempt to validate the simulator.ResultsEach of the five tasks displayed statistically significant learning curves. Error scores did not improve significantly over successive repetitions except in one task. The experts completed two of the tasks in a significantly faster time.ConclusionsPractice sessions on a VR simulator improve technical performance. The simulator enables surgeons to mount the early part of the learning curve within a laboratory environment, which may lead to a more effective training programme. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization challenges for nanomaterials
Authors: Baer D. R. , Amonette J. E. , Engelhard M. H. , Gaspar D. J. , Karakoti A. S. , Kuchibhatla S. , Nachimuthu P. , Nurmi J. T. , Qiang Y. , Sarathy V. , Seal S. , Sharma A. , Tratnyek P. G. , Wang C.‐M. 
Published: March 2008

AbstractNanostructured materials are increasingly subject to nearly every type of chemical and physical analysis possible. Due to their small sizes, there is a significant focus on tools with high spatial resolution. It is also natural to characterize nanomaterials using tools designed to analyze surfaces, because of their high surface area. Regardless of the approach, nanostructured materials present a variety of obstacles to adequate, useful, and needed analysis. Case studies of measurements on ceria and iron metal‐core/oxide‐shell nanoparticles are used to introduce some of the issues that frequently need to be addressed during analysis of nanostructured materials. We use a combination of tools for routine analysis including X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and x‐ray diffraction (XRD) and apply several other methods as needed to obtain essential information. The examples provide an introduction to other issues and complications associated with the analysis of nanostructured materials including particle stability, probe effects, environmental effects, specimen handling, surface coating, contamination, and time. Copyright © 2008 John Wiley & Sons, Ltd.
Nanomechanical properties of ion‐implanted Si
Authors: Nagy P. M. , Aranyi D. , Horváth P. , Pető G. , Kálmán E. 
Published: March 2008

AbstractThe nanomechanical properties of single crystalline silicon samples has gained wide attention in recent years, because of the abnormal loading effects, caused by the pressure‐induced phase transformation of silicon. To further enlighten the phenomenon bulk, ion‐implanted, single crystal Si samples have been studied by nanoindentation experiments, and by atomic force microscopy (AFM). The implantation of Si wafers was carried out by P ions at 40 KeV energy, influencing the defect density and structure of the Si material in shallow depth at the surface. Our experiments provide consistent evaluation of Young's modulus and hardness of the samples (measured with Berkovich‐, spherical‐ and cube corner indenters), statistics of the pop‐in and pop‐out effects during the indentation, and interesting results about the piling‐up behavior of the Si material. The plastic work on the sample was also evaluated in cyclic indentation experiments by calculating the area of the hysteresis loops in the load curve. Copyright © 2008 John Wiley & Sons, Ltd.
Formation of aldehyde‐ and carboxy‐terminated self‐assembled monolayers on SiO2 surfaces
Authors: Hozumi Atsushi , Taoda Hiroshi , Saito Takao , Shirahata Naoto 
Published: March 2008

AbstractAldehyde (CHO)‐ and carboxy (COOH)‐terminated self‐assembled monolayers (SAMs) were prepared on silicon substrates covered with native oxide (SiO2/Si) based on the chemisorption of triethoxysilylundecanal (TESUD) molecules and subsequent photooxidation of the terminal groups using 172‐nm vacuum UV light in wavelength, respectively. In this study, we have particularly focused on the effects of atmospheric pressure during vacuum UV irradiation on the degree of the SAM photooxidation. When irradiation was conducted under a residual pressure of 103 Pa, the hydrophobic TESUD‐SAM surface became hydrophilic and its water‐contact angle fell from approximately 80° to less than 5° within 1 min. Film thickness also decreased from about 1.2 nm to about 0.3 nm, indicating the complete photodecomposition of the organic parts of the TESUD‐SAM. On the other hand, in the case of 105 Pa, by selecting an appropriate time for vacuum UV irradiation, we were able to control the degree of photooxidation of the TESUD‐SAM. Using a vacuum UV irradiation of 25 min at 105 Pa, only the topmost region of the TESUD‐SAM was successfully photooxidized into COOH groups without any marked change in both film thickness and surface morphology, as evidenced by water‐contact angle data, ellipsometry, X‐ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Copyright © 2008 John Wiley & Sons, Ltd.
Interfacial characterization of chemical solution‐deposited thin films of PbSe on GaAs(100)
Authors: Shandalov Michael , Rozenblat Avraham , Kedem Nir , Popovitz‐Biro Ronit , Golan Yuval 
Published: March 2008

AbstractThe microstructure and composition of the interfacial layer between chemically deposited PbSe and GaAs substrates were studied using high‐resolution transmission electron microscopy (HRTEM), Auger electron spectroscopy (AES), x‐ray photoelectron spectroscopy (XPS) and energy‐filtered TEM.The thickness of the interfacial layer varied significantly from direct contact of the film with the substrate to 5 nm in the thickest regions. The results established the presence of a discontinuous, amorphous intermediate layer of Ga2O3 at the PbSe/GaAs interface. Copyright © 2008 John Wiley & Sons, Ltd.
Learning curve for Doppler assessment of ductus venosus flow at 11 + 0 to 13 + 6 weeks' gestation
Authors: Maiz N. , Kagan K. O. , Milovanovic Z. , Celik E. , Nicolaides K. H. 
Published: March 2008

AbstractObjectiveTo determine the number of scans necessary for training sonographers to examine accurately the ductus venosus at 11 + 0 to 13 + 6 weeks' gestation.MethodsTen sonographers with prior extensive experience in the measurement of nuchal translucency thickness were given practical training in the accurate assessment of the ductus venosus. They were then asked to examine the ductus venosus during the routine 11 + 0 to 13 + 6 weeks' scan. Each scan was assessed by an experienced sono‐ grapher and classified as being successful or unsuccessful (failure to obtain a waveform, poor quality image with contamination or wrong classification of the A‐wave). Each sonographer performed a total of 300 examinations, the data were analyzed in 15 groups of 20 examinations and in each group the percentage of unsuccessful examinations was calculated.ResultsIn the total 3000 cases examined by the 10 sonographers there were 2849 (95.0%) successful examinations and 151 unsuccessful, including 104 failures to obtain a waveform, 30 cases where the quality of the image was considered to be inadequate and 17 cases in which the classification of the A‐wave was wrong. The overall frequency of unsuccessful examinations decreased significantly with the number of scans carried out (r = 0.982, P < 0.0001). The sonographers required an average of 80 examinations before they could successfully examine the ductus in at least 19 of a group of 20 scans. Although one of the 10 trainees achieved this standard within the first block of 20 scans some of the sonographers required training in 100 cases.ConclusionCompetence in Doppler assessment of the ductus venosus is achieved only after extensive supervised training. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Three‐dimensional ultrasound improves the interobserver reliability of antral follicle counts and facilitates increased clinical work flow
Authors: Jayaprakasan K. , Campbell B. K. , Clewes J. S. , Johnson I. R. , Raine‐Fenning N. J. 
Published: March 2008

AbstractObjectivesTo compare the interobserver reliability of antral follicle counts made using real‐time two‐dimensional (2D) ultrasound with offline counts made from stored three‐dimensional (3D) data and to assess the time required for such counts.MethodsTwo observers conducted transvaginal ultrasound examinations in 45 subfertile women in the early follicular phase of the menstrual cycle. Antral follicles were counted using real‐time 2D ultrasound and the time taken was recorded. A 3D volume was then acquired from each ovary and stored for subsequent offline analysis using the multiplanar view. The time taken for each step was recorded and the total time was calculated. Intraclass correlation coefficients (ICC) and limits of agreement were used to assess reliability.ResultsThere was no difference in the mean antral follicle counts using real‐time 2D (16.51 ± 11.51) and 3D (16.33 ± 12.13) ultrasound. According to ICCs, there was a significantly higher interobserver reliability for counts made using 3D (mean, 0.992; 95% CI, 0.986–0.996) compared with real‐time 2D (mean, 0.961; 95% CI, 0.940–0.977) (P < 0.01) ultrasound. 3D ultrasound was also associated with narrower limits of agreement (−2.7 to + 3.1) than was 2D ultrasound (−6.9 to + 6.4). Whilst the total time taken was significantly longer for the 3D technique (239.3 ± 71.4 s vs. 103.1 ± 28.6 s, P < 0.001), the time required for the actual ultrasound examination was significantly less (46.4 ± 7.4 s vs. 103.1 ± 28.6 s, P < 0.001).Conclusions3D ultrasound significantly improves the interobserver reliability of antral follicle counts. While this is at the expense of time overall, the duration of the actual ultrasound examination and patient exposure is significantly reduced using 3D compared with real‐time 2D ultrasound. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Iranian Mothers’ Perceptions of Their Lives with Children with Mental Retardation: A Preliminary Phenomenological Investigation
Authors: Kermanshahi S. M. , Vanaki Z. , Ahmadi F. , Kazemnejad A. , Mordoch E. , Azadfalah P. 
Published: March 2008

AbstractThis phenomenological study explored Iranian mothers’ lived experiences of having a child with mental retardation (MR). Six mothers parenting a child with MR who attended a School for Exceptional Children were interviewed. Semi-structured interviews which encouraged the mothers to describe their experiences were audiotaped, transcribed and analyzed in accordance with Colaizzi’s (Existential phenomenological alternatives for psychology, New York, Oxford University Press, 1978) procedural steps. Six major themes were found in the data: Challenging the process of acceptance, painful emotional reactions, the inter-relatedness of the mother’s health and the child’s well being, struggles to deal with oneself or the child, inadequate support from the family and community, and anxiety related to the child’s uncertain future. Findings from this study contribute to a preliminary understanding of Iranian mothers’ experiences and needs. The results suggest introductory changes in nursing practice, staff education and program development to best serve mothers and their children with MR.
Laboratory Studies on Membrane Deoiling of Lecithin
Authors: Manjula S. , Subramanian R. 
Published: March 2008

AbstractDeoiling of lecithin using a nonporous membrane was examined in a favorable solvent (hexane) medium with soy and rice bran lecithins. During the membrane process, the acetone insoluble (AI) content of soy lecithin increased from 63.2 to 81.0% in a single step batch operation. The membrane exhibited an excellent selectivity since phospholipid (PL) reverse micelles formed in the system were rejected almost completely due to low solubility probably aided synergistically by size exclusion. Diafiltration achieved greater oil removal from lecithin as reflected in terms of higher AI and PL contents in the deoiled lecithin. In discontinuous diafiltration, the PL content increased from 33.3 to 85.5% in rice bran lecithin (150% dilution to feed) and 56.6 to 85.7% in soy lecithin (200% dilution), respectively. The simulated continuous diafiltration run showed slightly greater PL content in soy lecithin (91.3%) compared to discontinuous diafiltration (89.7%) besides offering higher productivity. The membrane showed a color reduction of ~60% in soy lecithin but there was no improvement in rice bran lecithin due to the retention of degradation products. The proposed integrated membrane process with nonporous (deoiling) and nanofiltration (solvent recovery) membranes could be an attractive preposition besides being an acetone free process.
Oxidized proteins in plasma of patients with heart failure: Role in endothelial damage
Authors: Banfi Cristina , Brioschi Maura , Barcella Simona , Veglia Fabrizio , Biglioli Paolo , Tremoli Elena , Agostoni PierGiuseppe 
Published: March 2008

AbstractBackground:Oxidative stress is increased in the failing heart, and this might contribute to the pathogenesis of myocardial remodelling and heart failure (HF).Aim:To identify the oxidized proteins in plasma of chronic HF patients and to evaluate their possible role in endothelial damage.Methods:Plasma levels of oxidized proteins were measured by immunoassay and by analysis in albumin and immunoglobulin depleted plasma using a proteomic approach, in 40 HF patients and in 20 age‐matched normal subjects. Analysis of the effects of proteins oxidized in vitro on human endothelial cell (EC) viability was also performed.Results:Plasma levels of oxidized proteins were significantly higher in HF patients than in controls (p < 0.01). We identified two proteins, α‐1‐antitrypsin and fibrinogen, which underwent oxidation. Oxidation of α‐1‐antitrypsin resulted in loss of its protease inhibitor activity, thus leading to EC death in the presence of elastase. Fibrinogen, when oxidized, became otherwise cytotoxic and induced apoptosis in EC.Conclusions:This study shows that plasma levels of oxidized proteins are increased in HF, and permitted the identification of two proteins, namely α‐1‐antitrypsin and fibrinogen, which underwent oxidation. In vitro results highlighted the potential role of oxidized proteins in the EC damage that occurs in HF.
Responders to cardiac resynchronization therapy with narrow or intermediate QRS complexes identified by simple echocardiographic indices of dyssynchrony: The DESIRE study
Authors: Cazeau Serge J. , Daubert J‐Claude , Tavazzi Luigi , Frohlig Gerd , Paul Vince 
Published: March 2008

AbstractBackground:Cardiac resynchronization therapy (CRT) is recommended for patients with NYHA class III–IV refractory heart failure (HF), ejection fraction <35% and a QRS >120ms. We attempted to identify responders to CRT from echocardiographic (echo) indices of mechanical dyssynchrony in patients with QRS < 150 ms.Methods and results:The study enrolled 51 men and 9 women (mean age: 64.5years) in NYHA class III (n=54) or IV (n=6) presenting with a mean ejection fraction: 25.7%, LV end‐diastolic diameter: 69.1mm, and QRS = 121 ± 19 ms. All patients were implanted with a CRT system and followed for 1year. Implantation was preceded and followed by clinical, functional and Doppler (D)‐echo evaluation. The primary combined endpoint included 1) death from any cause, 2) HF‐related hospitalisations, and 3) NYHA class at 6 months. Before implant, 27 patients had ≥ 1 echo criterion of mechanical dyssynchrony (DES+ group) and 33 had no evidence of dyssynchrony (DES− group). At 12months, 8 patients (4 per group) had died, 7 from HF. As regards the primary endpoint at 6 months, 33 patients (55%) had improved, 10 (16%) were unchanged, and 17 (29%) had deteriorated. Clinical improvement was observed in 19 of 27 DES+ (70%), versus 14 of 33 DES− (42%) patients (P<0.04). Baseline QRS duration did not predict response to CRT.Conclusions:In this population of HF patients with QRS < 150 ms, the presence of mechanical dyssynchrony at baseline D‐echo examination, but not the QRS width, predicted 6‐month clinical response to CRT.