bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and catalytic activity of polymer supported ruthenium Schiff base complexes towards catechol oxidation
Authors: Pearly Sebastian C. , Sridevi N. , Mohammed Yusuff K. K. 
Published: April 2007

AbstractRuthenium(III) complexes of the Schiff bases formed by the condensation of polymer bound aldehyde and the amines, such as 1,2‐phenylenediamine (PS‐opd), 2‐aminophenol (PS‐ap), and 2‐aminobenzimidazole (PS‐ab) have been prepared. The magnetic moment, EPR and electronic spectra suggest an octahedral structure for the complexes. The complexes of PS‐opd, PS‐ap, and PS‐ab have been assigned the formula [PS‐opdRuCl3(H2O)], [PS‐apRuCl2(H2O)2], [PS‐abRuCl3(H2O)2], respectively. These complexes catalyze oxidation of catechol using H2O2 selectively to o‐benzoquinone. The catalytic activity of the complexes is in the order [PS‐abRuCl3(H2O)2] ≫ [PS‐opdRuCl3(H2O)] ≫ [PS‐apRuCl2(H2O)2]. Mechanism of the catalytic oxidation of catechol by ruthenium(III) complex is suggested to take place through the formation of a ruthenium(II) complex and its subsequent oxidation by H2O2 to the ruthenium(III) complex. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermosetting polyurethane multiwalled carbon nanotube composites
Authors: McClory Caroline , McNally Tony , Brennan Gerard P. , Erskine James 
Published: April 2007

AbstractThermosetting polyurethane (PU) multi‐walled carbon nanotube (MWCNT) nanocomposites at loadings up to 1 wt % were prepared via an addition polymerization reaction. The morphology of the nanocomposites and degree of dispersion of the MWCNTs was studied using a combination of scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and wide angle X‐ray diffraction (WAXD), and revealed the nanotubes to be highly dispersed in the PU matrix. Addition of just 0.1 wt % MWCNTs resulted in significant enhancements in stiffness, strength and toughness. Increases in Young's modulus, % elongation at break and ultimate tensile strength of 561, 302 and 397% were measured for the nanocomposites compared to the unfilled PU. The effect of the MWCNTs on the modulus of the PU was evaluated using the Rule of Mixtures, Krenchel and Halpin‐Tsai models. Only the Halpin‐Tsai model applied to high aspect ratio nanotubes was in good agreement with the modulus values determined experimentally. Strong interfacial shear stress was found between PU chains and nanotubes, up to 439 MPa, calculated using a modified Kelly‐Tyson model. Evidence for strong interfacial interactions was obtained from the Raman spectra of both the precursor materials and nanocomposites. When the MWCNTs were added to the isophorone diisocyanate an up‐shift of 14 cm−1 and on average 40 cm−1 was obtained for the position of the carbon‐hydrogen (CH) out‐of plane bending (766 cm−1) and isocyanate symmetric stretch (1420 cm−1) modes respectively. Moreover, an up‐shift of 24 cm−1 was recorded for the nanotube tangential mode (G‐band) for the 1.0 wt % nanocomposite because of the compressive forces of the PU matrix acting on the MWCNTs. The dynamic mechanical (DMA) properties of the PU thermoset and the nanocomposites were measured as a function of temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermosetting foam with a high bio‐based content from acrylated epoxidized soybean oil and carbon dioxide
Authors: Bonnaillie Laetitia M. , Wool Richard P. 
Published: April 2007

AbstractA resilient, thermosetting foam system with a bio‐based content of 96 wt % (resulting in 81% of C14) was successfully developed. We implemented a pressurized carbon dioxide foaming process that produces polymeric foams from acrylated epoxidized soybean oil (AESO). A study of the cell dynamics of uncured CO2/ AESO foams proved useful to optimize cure conditions. During collapse, the foam's bulk density increased linearly with time, and the cell size and cell density exhibited power‐law degradation rates. Also, low temperature foaming and cure (i.e. high viscosity) are desirable to minimize foam cell degradation. The AESO was cured with a free‐radical initiator (tert‐butyl peroxy‐2‐ethyl hexanoate, Ti ∼ 60°C). Cobalt naphtenate was used as an accelerator to promote quick foam cure at lower temperature (40–50°C). The foam's density was controlled by the carbon dioxide pressure inside the reactor and by the vacuum applied during cure. The viscosity increased linearly during polymerization. The viscosity was proportional to the extent of reaction before gelation, and the cured foam's structure showed a dependence on the time of vacuum application. The average cell size increased and the cell density decreased with foam expansion at a low extent of cure; however, the foam expansion became limited and unhomogeneous with advanced reaction. When vacuum was applied at an intermediate viscosity, samples with densities ∼ 0.25 g/cm3 were obtained with small (<1 mm) homogeneous cells. The mechanical properties were promising, with a compressive strength of ∼ 1 MPa and a compressive modulus of ∼ 20 MPa. The new foams are biocompatible. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Influence of solid particles on cavitation in poly(methylene oxide) during crystallization
Authors: Nowacki Radoslaw , Piorkowska Ewa 
Published: April 2007

AbstractCavitation in pockets of melt occluded by impinging spherulites during isothermal crystallization of poly(methylene oxide) was explored. A reason for cavitation is a negative pressure buildup in pockets because of the change of density during crystallization. Compositions of poly(methylene oxide) with talc and chalks unmodified and modified with calcium stearate were studied to determine the influence of foreign solid particles on the cavitation. The crystallization and cavitation in polymer films were observed by a light microscopy; sample surfaces were examined also under SEM. The spherulite growth rate, decreasing under negative pressure, was measured and used to estimate the negative pressure level at the moment of cavitation that is the strength of the polymer melt. Chalk modified with calcium stearate drastically lowered the strength of poly(methylene oxide) melt, whereas unmodified chalk did not. The effect depended on the chalk content and on the particle size. The results demonstrate that the cavitation in a polymer melt under the negative pressure is nucleated by solid particles poorly adhering to a polymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Degradation of a poly(ester urethane) elastomer. IV. Sorption and diffusion of water in PBX 9501 and its components
Authors: Salazar Michael R. , Thompson Shelley L. , E. Laintz Kenneth , Meyer Thomas O. , Pack Russell T 
Published: April 2007

AbstractIn preparation for studying the hydrolytic degradation of Estane® 5703 in the plastic‐bonded explosive PBX 9501, the sorption (solubility) and diffusion of water in PBX 9501 and each of its components are studied experimentally and modeled theoretically. Experiments are reported that measure the weight gain or loss due to a change in the relative humidity (RH). For all of the components, the equilibrium amount of water sorbed per gram of sample is linear in the RH at low relative humidities but curves upwards at higher relative humidities. This behavior is modeled with a water cluster model. Diffusion coefficients are determined by modeling the time dependence of the water concentrations assuming Fickian diffusion, and that fits the data for some of the materials. However, all the samples that contain the explosive HMX show much more complicated behavior at high relative humidities, and that is presented and discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface modification of a polyurethane film by low pressure glow discharge oxygen plasma treatment
Authors: Sanchis M. R. , Calvo O. , Fenollar O. , Garcia D. , Balart R. 
Published: April 2007

AbstractLow pressure oxygen plasma has been used to improve the surface wettability of a polyurethane film. The modifications induced by the plasma treatment in the material were analyzed using contact angle measurements. X‐ray photoelectron spectroscopy technique was used for surface characterization of the plasma‐treated films. Atomic force microscopy and scanning electron microscopy were used to analyze topography changes due to the plasma‐etching mechanism. The results show a much better surface wettability of the film even for short exposure times, with a considerable increase in the surface energy values. As expected, functionalization with oxygen plasma is mainly because of surface oxidation with species like (CO, CO, OH, etc). An aging process with regard to polar groups rearrangement has been observed, thus promoting a partial hydrophobic recovery. Besides functionalization, the surface wettability of the material improves as a consequence of a slight increase in surface roughness because of the etching effect of oxygen plasma. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Percutaneous rheolytic thrombectomy for large pulmonary embolism: A promising treatment option
Authors: Chauhan Manish S. , Kawamura Akio 
Published: April 2007

AbstractBackground: Pulmonary embolism (PE) is a common cardiovascular disease with significant mortality. Some patients with large PE are not eligible for current treatment options such as thrombolysis or surgical embolectomy. We report our experience of percutaneous rheolytic thrombectomy (PRT) using the AngioJet system combined with adjunctive local thrombolytic therapy and inferior vena cava (IVC) filter placement to treat massive or submassive PE in patients ineligible for current treatment options. Methods and Results: Of the 14 consecutive patients ineligible for thrombolysis or embolectomy treated with PRT, 10 patients had massive PE (6 patients were hypotensive and 4 patients had intractable hypoxemia) and 4 patients had submassive PE. Adjunctive local thrombolysis was performed in 5 patients. An IVC filter was placed in 11 patients. Angiographic success based on Miller score was achieved in 13 patients (92.9%). Procedure success was obtained in 12 patients (85.7%). Procedural mortality occurred in one patient who presented in cardiogenic shock (7.1%) and non‐fatal hemoptysis occurred in 1 patient (7.1%). Total in‐hospital mortality occurred in 3 patients (21.4%). On a mean follow‐up of 9 months, all 11 survivors had noted significant improvement in symptoms without recurrence. Conclusions: Percutaneous rheolytic thrombectomy using the AngioJet may be a treatment option for patients with massive or submassive PE who may not be eligible for thrombolytic therapy or surgical embolectomy. © 2007 Wiley‐Liss, Inc.
Coronary stent assessability by 64 slice multi‐detector computed tomography
Authors: Sheth Tej , Dodd Jonathan D. , Hoffmann Udo , Abbara Suhny , Finn Aloke , Gold Herman K. , Brady Thomas J. , Cury Ricardo C. 
Published: April 2007

AbstractBackground: We evaluated the assessability of contemporary stent platforms by 64‐slice multi‐detector computed tomography (MDCT). Methods. Patients undergoing coronary stenting were included in a prospective protocol of MDCT imaging within 48 hr of stent implantation. MDCT data were acquired using a “Sensation 64” MDCT scanner (Siemens Medical Solutions, Forchheim, Germany). Stent assessability was assessed by two independent blinded observers and disagreement was resolved by a third observer. Assessability was defined at visualization of the in‐stent lumen without influence of partial volume effects, beam hardening, motion, calcification, or contrast to noise limitations. Results: Fifty four stents (Cypher n = 25, Vision/Minivision n = 19, Taxus Express n = 8, Liberte n = 1, Driver n = 1) in 44 patients were included in the study. The two independent observers classified 30 of 54 stents (56%) as assessable. Interobserver reproducibility was good with κ = 0.66. Stent size was the most important determinant of assessability. Consistently assessable stents were 3.0 mm or larger (85%), whereas those under 3 mm were mostly nonassessable (26%).Conclusions: Contemporary stent designs evaluated on a 64‐slice MDCT scanner showed artifact free assessability only in larger stents. Increase in spatial resolution of MDCT scanners or modifications in stent design will be necessary to noninvasive evaluate stents <3 mm in diameter, where in‐stent restenosis is more frequent. © 2007 Wiley‐Liss, Inc.
Percutaneous coronary intervention in two occluded arms of a saphenous ‘Y’‐graft: The importance of protecting both of your arms
Authors: Chan Roger S. , Duong Michael H. , Kaplan Aaron V. 
Published: April 2007

AbstractPercutaneous intervention in saphenous vein grafts (SVG) carries a higher risk of distal embolization than intervention in a native vessel, and use of a distal protection device has been shown to improve the outcomes in SVG interventions. We describe an intervention done in an unexpected ‘Y’ SVG which required dual distal protection with Filterwires placed in both limbs of the diseased graft and which was performed via a 6 Fr guide catheter. © 2007 Wiley‐Liss, Inc.
Percutaneous closure after inadvertent subclavian artery cannulation
Authors: Shetty Sharad V. , Kwolek Christopher J. , Garasic Joseph M. 
Published: April 2007

AbstractAccidental insertion of an arterial sheath is an uncommon but potentially serious complication of jugular venous catheterization. When the subclavian artery is inadvertently cannulated, sheath removal can be complicated by significant hemorrhage due to its incompressible location. We report a case of inadvertent insertion of an 8 French sheath into the subclavian artery, which was successfully removed and the puncture site sealed with a collagen‐based vascular closure device (Angio‐Seal STS Plus). This averted an otherwise emergent open surgical procedure to remove the sheath and repair the subclavian artery in a high‐risk patient. © 2007 Wiley‐Liss, Inc.
Coronary stenting for coronary vasospasm refractory to medical therapy
Authors: Burns Andrew , Malaiapan Yuvaraj , Meredith Ian 
Published: April 2007

AbstractWe describe the case of a 54‐year‐old male with recurrent chest pain, ST segment elevation, and bradycardia. Coronary vasospasm was confirmed by acetylcholine challenge. After failing medical therapy, stenting of an extensive segment of the right coronary artery has been clinically successful after 24‐months follow‐up. © 2007 Wiley‐Liss, Inc.
Predictors of comprehensive surgical treatment in patients with ovarian cancer
Authors: Goff Barbara A. , Matthews Barbara J. , Larson Eric H. , Andrilla C. Holly A. , Wynn Michelle , Lishner Denise M. , Baldwin Laura‐Mae 
Published: April 2007

AbstractBACKGROUND.Providing appropriate surgical treatment for women with ovarian cancer is one of the most effective ways to improve ovarian cancer outcomes. In this study, the authors identified factors that were associated with a measure of comprehensive surgery, so that interventions may be targeted appropriately to improve surgical care.METHODS.Using Healthcare Cost and Utilization Project hospital discharge data from 1999 to 2002 for 9 states, the authors identified 10,432 admissions of women who had an International Classification of Disease, 9th Revision (ICD‐9) primary diagnosis of ovarian cancer and who had undergone oophorectomy. Based on National Institutes of Health Consensus Panel recommendations, surgeries were categorized as comprehensive by using ICD‐9 diagnosis and procedure codes. Logistic regression analysis using data from 5 states with a full set of variables (n = 6854 patients)was used to identify factors that were associated with the receipt of comprehensive surgical care.RESULTS.Overall, 66.9% of admissions (range, 46.3–80.8% of admissions) received comprehensive surgery. Factors that were associated independently with comprehensive surgical care included age (ages 21–50 years vs ages 71–80 years or ≥81 years), race (Caucasian vs African American or Hispanic), payer (private insurance vs Medicaid), cancer stage (advanced vs early), annual surgeon volume (low/medium [2–9 surgeries per year] or high [>10 surgeries per year] vs very low [1 surgery per year]), and surgeon specialty (gynecologic oncologists vs obstetrician gynecologists or general surgeons). Among nonteaching hospitals, medium‐volume hospitals (10–19 ovarian cancer surgeries per year) and high‐volume hospitals (≥20 surgeries per year) had significantly higher comprehensive surgery rates than low‐volume facilities (1–9 surgeries per year). Volume did not influence comprehensive surgery rates in teaching hospitals.CONCLUSIONS.Many women with ovarian cancer, especially those in poor, elderly, or minority groups, are not receiving recommended comprehensive surgery. Efforts should be made to ensure that all women with ovarian cancer, especially those in vulnerable populations, have the opportunity to receive care from centers or surgeons with higher comprehensive surgery rates. Cancer 2007. © 2007 American Cancer Society.
Renal cell carcinoma clinically involving adjacent organs
Authors: Margulis Vitaly , Sánchez‐Ortiz Ricardo F. , Tamboli Pheroze , Cohen Daniel D. , Swanson David A. , Wood Christopher G. 
Published: April 2007

AbstractBACKGROUND.Historically, patients with nonmetastatic renal cell carcinoma (RCC) involving adjacent organs have been considered inoperable and incurable. The oncologic efficacy of an aggressive surgical approach was evaluated in a selected subpopulation of RCC patients. Further, an attempt was made to define the clinical and pathologic characteristics predictive of surgical failure.METHODS.With Institutional Review Board approval, the institutional nephrectomy database of 3470 patients treated at MD Anderson Cancer Center from 1990 to 2006 was searched for RCC patients treated with radical nephrectomy and resection of at least 1 adjacent organ thought to be directly involved by RCC. Patients with nonmetastatic RCC and a minimum follow‐up of 6 months were included in the analysis.RESULTS.In all, 30 patients with clinical T4NxM0 RCC and median follow‐up of 32.3 months (range, 8.5–140.1) met the study inclusion criteria and comprise the dataset for the analysis. On pathologic evaluation 60% of patients were clinically overstaged, as only 12 (40%) of 30 patients demonstrated direct invasion into adjacent organs resected. None of the clinical tumor characteristics predicted a finding of pathologic T4 RCC. Nodal involvement and pathologic T stage were significant independent predictors of disease recurrence (hazard ratio [HR] 3.726, P = .043, and HR 2.414, P = .045, respectively) and cancer‐specific survival (HR 17.145, P = .002, and HR 3.791, P = .024, respectively). Disease recurred in 11 of 18 (61.1%) of <pT4 patients and in 10 of 12 (83.3%) of pT4 patients at a median 13.3 and 2.3 months, respectively; 13 (73.3%) <pT4 patients and 5 (41.7%) pT4 patients were alive at the time of analysis.CONCLUSIONS.True pathologic involvement of adjacent organs by RCC cannot be predicted from pre‐ or intraoperative parameters. A significant proportion of patients clinically suspected of having T4 RCC are downstaged, and benefit from aggressive surgical resection with en bloc removal of involved organs. Cancer 2007. © 2007 American Cancer Society.
Does having insurance affect differences in clinical presentation between Hispanic and non‐Hispanic white women with breast cancer?
Authors: Watlington A. Tyler , Byers Tim , Mouchawar Judy , Sauaia Angela , Ellis Jenn 
Published: April 2007

AbstractBACKGROUNDHispanic women with breast cancer present differently than do non‐Hispanic white (NHW) women. Lack of access to care has been offered as an explanation for these differences. In this study breast cancer presentation was examined in Hispanic women in a comprehensive, equal‐access health care system.METHODSHispanic and NHW breast cancer cases registered between 1995 and 2004 in the Kaiser Permanente of Colorado Tumor Registry were compared by age at diagnosis, stage, tumor grade, size, and receptor status. Multivariate logistic regression was performed to generate age‐adjusted odds ratios by ethnicity and each tumor characteristic.RESULTSA total of 139 Hispanic women and 2118 NHW women with breast cancer were identified. Hispanic women had a mean average age at diagnosis of 56 years compared with 61 years for NHW women (P < .0001). Use of mammographic screening services in the prior 2 years was similar by ethnicity. Relative to NHW women, Hispanic women had age‐adjusted odds ratios of 2.70 (95% confidence interval [CI]: 1.26–5.77) for having stage IV disease, 2.25 (95% CI: 1.39–3.67) for having poorly differentiated tumors, 2.16 (95% CI: 1.26–3.69) for having a tumor greater than 5 cm, and 1.88 (95% CI: 1.24–2.81) for having estrogen receptor‐negative tumors.CONCLUSIONSDespite equal access to health care services, differences persist in the size, stage, and grade of breast cancer for Hispanic women compared with NHW women. The results of the study suggest a biologic/genetic basis for these differences. Cancer 2007. © 2007 American Cancer Society.
Limits of propidium iodide as a cell viability indicator for environmental bacteria
Authors: Shi Lei , Günther Susanne , Hübschmann Thomas , Wick Lukas Y. , Harms Hauke , Müller Susann 
Published: April 2007

AbstractBackground:Viability measurements of individual bacteria are applied in various scopes of research and industry using approaches where propidium iodide (PI) serves as dead cell indicator. The reliability of PI uptake as a cell viability indicator for dead (PI permeable) and viable (PI impermeable) bacteria was tested using two soil bacteria, the gram−Sphingomonas sp. LB126 and the gram+Mycobacterium frederiksbergense LB501T.Methods:Bacterial proliferation activities observed viaDAPI and Hoechst 33342 staining were linked to the energy charge and the proportion of dead cells as obtained by diOC6 (3)‐staining and PI‐uptake, respectively. Calibration and verification experiments were performed using batch cultures grown on different substrates.Results:PI uptake depended on the physiological state of the bacterial cells. Unexpectedly, up to 40% of both strains were stained by PI during early exponential growth on glucose when compared to 2–5% of cells in the early stationary phase of growth.Conclusions:The results question the utility of PI as a universal indicator for the viability of (environmental) bacteria. It rather appears that in addition to nonviable cells, PI also stains growing cells of Sphingomonas sp. and M. frederiksbergense during a short period of their life cycle. © 2007 International Society for Analytical Cytology