bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modification of polyurethaneurea with PEG and YIGSR peptide to enhance endothelialization without platelet adhesion
Authors: Jun Ho‐Wook , West Jennifer L. 
Published: August 2004

AbstractImproved endothelialization without platelet adhesion is essential to enhance the long‐term patency of synthetic vascular grafts and other blood‐contacting devices. We have developed a dually modified polyurethaneurea by incorporating endothelial cell adhesive YIGSR peptide sequences as chain extenders and nonthrombogenic PEG as a soft segment (PUUYIGSR‐PEG) in the polymer backbone. PUUYIGSR‐PEG was successfully synthesized and characterized by proton NMR, FTIR, GPC, DSC, ESCA, and contact angle measurement. Despite having similar molecular weight, the peptide/PEG‐modified polyurethaneurea (PUUYIGSR‐PEG) showed superior mechanical properties compared to the control PEG‐modified polyurethaneurea (PUUPPD‐PEG). Virtually no platelet adhesion was observed on PUUYIGSR‐PEG, while endothelial cell adhesion, spreading, and migration were significantly greater on PUUYIGSR‐PEG compared to PUUPPD‐PEG. Thus, this bioactive polymer may be an appropriate biomaterial for small diameter vascular grafts. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 131–139, 2005
Preprocessing of rotamers for protein design calculations
Authors: Shah Premal S. , Hom Geoffrey K. , Mayo Stephen L. 
Published: August 2004

AbstractWe have developed a process that significantly reduces the number of rotamers in computational protein design calculations. This process, which we call Vegas, results in dramatic computational performance increases when used with algorithms based on the dead‐end elimination (DEE) theorem. Vegas estimates the energy of each rotamer at each position by fixing each rotamer in turn and utilizing various search algorithms to optimize the remaining positions. Algorithms used for this context specific optimization can include Monte Carlo, self‐consistent mean field, and the evaluation of an expression that generates a lower bound energy for the fixed rotamer. Rotamers with energies above a user‐defined cutoff value are eliminated. We found that using Vegas to preprocess rotamers significantly reduced the calculation time of subsequent DEE‐based algorithms while retaining the global minimum energy conformation. For a full boundary design of a 51 amino acid fragment of engrailed homeodomain, the total calculation time was reduced by 12‐fold. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1797–1800, 2004
Lipid micelles stimulate the secretion of triglyceride‐enriched apolipoprotein B48‐containing lipoproteins by Caco‐2 cells
Authors: Chateau Danielle , Pauquai Thomas , Delers François , Rousset Monique , Chambaz Jean , Demignot Sylvie 
Published: August 2004

AbstractIntestinal triglyceride‐rich lipoproteins (TRL) are synthesized from dietary lipids. This study was designed to evaluate the effects of lipid micelles, mimicking post‐digestive duodenal micelles, on the fate of apolipoprotein B (apoB)48‐containing lipoproteins by Caco‐2 cells. Such micelles, consisting of oleic acid (OA), taurocholate, 2‐monooleoylglycerol (2‐MO), cholesterol (Chol), and L‐α‐lysophospatidylcholine, were the most efficient inducers of OA uptake and esterification. The efficiency of TG and apoB48 secretion increased specifically as a function of cell differentiation. PAGE analysis of secreted lipoproteins separated by sequential ultracentrifugation after [35S] labeling revealed differences in the secretion of apoB100‐ and apoB48‐containing lipoproteins. In absence of micelles, apoB48 was secreted mostly in “HDL‐like” particles, as observed in enterocytes in vivo. Micelle application increased 2.7‐fold the secretion of apoB, resulting in 53 times more apoB48 being recovered as TG‐enriched lipoproteins at d < 1.006 g/ml. Electron microscopy revealed the presence of lipid droplets in the secretory pathway and the accumulation of newly synthesized TG in cytoplasmic lipid droplets, as in enterocytes in vivo. We showed that these droplets could be used for secretion. However, apoB48 preferentially bound to newly synthesized TG in the presence of micelles, accounting in part for the functional advantage of apoB editing in the intestine. While Caco‐2 cells express both apoB isoforms, our results show that the apical supply of complex lipid micelles favors the physiological route of apoB48‐containing TG‐enriched lipoproteins. © 2004 Wiley‐Liss, Inc.
Prospect of temperature determination using degenerate four‐wave mixing with sub‐20 fs pulses
Authors: Hornung Thomas , Skenderović Hrvoje , Kompa Karl‐Ludwig , Motzkus Marcus 
Published: August 2004

AbstractFemtosecond time‐resolved degenerate four‐wave mixing (DFWM) spectroscopy with ultrashort laser pulses was applied to probe pure rotational Raman transitions of the H2 molecule. Owing to the broad bandwidth of the sub‐20 fs pulse, several pure rotational Stokes and anti‐Stokes transitions are simultaneously excited with the same pulse, making the experiment relevant for thermometry in combustion processes. Simulations of the DFWM signal accurately predict how the change in population distribution due to changes in temperature influences the shape of the transients and the corresponding Fourier transform. The influence of the pulse duration was also investigated. The relative peak intensities in fast Fourier transform spectra were employed for temperature determination. First measurements at room temperature show good agreement with theory. Copyright © 2004 John Wiley & Sons, Ltd.
Determination of ergosterol in paddy rice using solid phase extraction
Authors: Srzednicki George , Craske John , Nimmuntavin Chintana , Mantais Linda George , Wattananon Saranya 
Published: August 2004

AbstractErgosterol, the predominant sterol found in most fungi, is considered as an indicator of fungal invasion in grain. An extraction method based on solid phase extraction (SPE) has been developed for determination of ergosterol in unmilled rice, generally called paddy. The samples obtained by extraction through SPE have been analysed by HPLC. The method has been validated in experiments with paddy subjected to different drying treatments and recoveries above 85% have been obtained. SPE appeared to be simple, quick, reliable and consistent for ergosterol analysis. The ergosterol levels obtained in the paddy samples were found to be within the expected range and were comparable with those found using conventional methods. Copyright © 2004 Society of Chemical Industry
Thermosensitive Micelles Self‐Assembled by Novel N‐Isopropylacrylamide Oligomer Grafted Polyphosphazene
Authors: Zhang Jian Xiang , Qiu Li Yan , Zhu Kang Jie , Jin Yi 
Published: August 2004

AbstractSummary: A novel thermosensitive amphiphilic copolymer of PNIPAm grafted polyphosphazene (PNIPAm‐g‐PPP) has been synthesized through a co‐substitution reaction of poly(dichlorophosphazene) with amino terminated NIPAm oligomer and glycine ethyl ester (GlyEt). The polymer obtained had a molar ratio of 1:5.25 PNIPAm to GlyEt and had a lower critical solution temperature (LCST) near 30 °C. The formation of polymeric micelles was confirmed by fluorescence, dynamic light scattering and transmission electron microscopy measurements.The structure and formation of thermosensitive micelles of poly(N‐isopropylacrylamide) grafted polyphosphazenes synthesized here.imageThe structure and formation of thermosensitive micelles of poly(N‐isopropylacrylamide) grafted polyphosphazenes synthesized here.
High‐Density Polyethylene Micro‐ and Nanocomposites: Effect of Particle Shape, Size and Surface Treatment on Polymer Crystallinity and Gas Permeability
Authors: Osman Maged A. , Atallah Ayman 
Published: August 2004

AbstractSummary: High‐density polyethylene (HDPE) micro‐ and nanocomposites with spherical and platelike inclusions were prepared and the effect of filler particles on polymer crystallinity and gas permeability was investigated. Platelike inclusions strongly reduce the polymer permeability coefficient, while spherical ones have no influence on it, irrespective of their size. The reduction in gas permeability depends on the average aspect ratio of the inclusions, which in turn depends on the exfoliation of the organo‐montmorillonites (OM) and consequently on its surface treatment.A TEM micrograph of 3 vol.‐% 2C18 · M‐HDPE nanocomposite, showing partial exfoliation of the organo‐montmorillonite.imageA TEM micrograph of 3 vol.‐% 2C18 · M‐HDPE nanocomposite, showing partial exfoliation of the organo‐montmorillonite.
Blastocysts produced by nuclear transfer between chicken blastodermal cells and rabbit oocytes
Authors: Liu Shu‐Zhen , Zhou Zhen‐Ming , Chen Tao , Zhang Yan‐Ling , Wen Duan‐Cheng , Kou Zhao‐Hui , Li Zan‐Dong , Sun Qing‐Yuan , Chen Da‐Yuan 
Published: August 2004

AbstractInterspecies nuclear transfer (INT) has been used as an invaluable tool for studying nucleus–cytoplasm interactions; and it may also be a method for rescuing endangered species whose oocytes are difficult to obtain. In the present study, we investigated interaction of the chicken genome with the rabbit oocyte cytoplasm. When chicken blastodermal cells were transferred into the perivitelline space of rabbit oocytes, 79.3% of the couplets were fused and 9.7% of the fused embryos developed to the blastocyst stage. Both M199 and SOF medium were used for culturing chicken–rabbit cloned embryos; embryo development was arrested at the 8‐cell stage obtained in SOF medium, while the rates of morulae and blastocysts were 12.1 and 9.7%, respectively, in M199 medium. Polymerase chain reaction (PCR) amplification of nuclear DNA and karyotype analyses confirmed that genetic material of morulae and blastocysts was derived from the chicken donor cells. Analysis mitochondrial constitution of the chicken–rabbit cloned embryos found that mitochondria, from both donor cells and enucleated oocytes, co‐existed. Our results suggest that: (1) chicken genome can coordinate with rabbit oocyte cytoplasm in early embryo development; (2) there may be an 8‐ to 16‐cell stage block for the chicken–rabbit cloned embryos when cultured in vitro; (3) mitochondrial DNA from the chicken donor cells was not eliminated until the blastocyst stage in the chicken–rabbit cloned embryos; (4) factors existing in ooplasm for somatic nucleus reprogramming may be highly conservative. Mol. Reprod. Dev. 69: 296–302, 2004. © 2004 Wiley‐Liss, Inc.
Tension‐free vaginal tape (TVT) for the treatment of occult stress urinary incontinence in women undergoing prolapse repair: A prospective study of 100 consecutive cases
Authors: Groutz Asnat , Gold Ronen , Pauzner David , Lessing Joseph B. , Gordon David 
Published: August 2004

AbstractAimsClinically continent women with genitourinary prolapse and occult stress urinary incontinence (SUI) are considered to be at high risk of developing symptomatic SUI once the prolapse is repaired. We studied the efficacy and safety of tension‐free vaginal tape (TVT) procedure in preventing postoperative SUI in these women.MethodsOne hundred consecutive women (mean age 66.7 ± 9.9 years) with significant genitourinary prolapse and occult SUI were prospectively enrolled. Preoperatively, none of the women complained of SUI. However, all had urodynamically‐confirmed occult SUI, revealed by repositioning of the prolapse. Surgical intervention was comprised of transvaginal prolapse repair and prophylactic TVT procedure. Main outcome end points included operative morbidity, postoperative SUI, persistent or de novo urge incontinence, and voiding dysfunction.ResultsThe mean follow‐up period was 27 months (range: 12–52 months). There was only one case of technique‐related bladder perforation with no adverse outcome. Two other patients had postoperative urinary retention necessitating catheterization for more than 7 days, none of whom required any surgical intervention. Vaginal erosion of the tape was diagnosed in three patients, all of whom were successfully treated by excision of the eroded tape. Two (2%) patients developed urodynamically‐confirmed SUI within 1 year postoperatively. However, postoperative urodynamics revealed asymptomatic sphincteric incontinence in 15 (15%) other patients. Thirteen (72%) of 18 patients with preoperative urge incontinence had postoperative persistent urge incontinence. De novo urge incontinence developed postoperatively in 8 (8%) patients.ConclusionsTVT procedure is effective and safe in patients with occult SUI undergoing prolapse repair. Long‐term durability of this procedure is yet to be established. © 2004 Wiley‐Liss, Inc.
Quantifying optimal mesh and ring design costs
Authors: Stidsen Thomas , Glenstrup Arne John 
Published: August 2004

AbstractDuring the last decade telecommunication operators have been deploying WDM (Wavelength Division Multiplexing) technology to satisfy the exponential growth in global communication. While facilitating the advanced information society of today, this has also led to a higher dependency on the networks, and furthermore the high capacity utilization of optical fibers means that a single link failure will influence many users and enterprises. For these reasons, protection of network connections has become a major competitive parameter for the operators. Currently, the most popular protection method is ring protection, due to its simplicity, requiring only basic management functionality and operating with local restoration control. While many optical rings have been deployed, little work has been published on exactly what the cost of ring networks are, compared to general mesh networks. In this article we perform a quantitative comparison between ring protection and mesh protection, using real world network data and realistic prices for network components. Extending classic LP flow models to take rings and node costs into account, and using a link‐path based mesh network LP model, we are able to perform a total cost comparison of the two architectures, and of manual ring network design. The results suggest that the price of mesh network components must be reduced significantly to be competitive with ring based networks, and also that manual network design does not necessarily lead to the most cost‐efficient designs. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005
A distributed memory parallel implementation of the multigrid method for solving three‐dimensional implicit solid mechanics problems
Authors: Namazifard A. , Parsons I. D. 
Published: August 2004

AbstractWe describe the parallel implementation of a multigrid method for unstructured finite element discretizations of solid mechanics problems. We focus on a distributed memory programming model and use the MPI library to perform the required interprocessor communications. We present an algebraic framework for our parallel computations, and describe an object‐based programming methodology using Fortran90. The performance of the implementation is measured by solving both fixed‐ and scaled‐size problems on three different parallel computers (an SGI Origin2000, an IBM SP2 and a Cray T3E). The code performs well in terms of speedup, parallel efficiency and scalability. However, the floating point performance is considerably below the peak values attributed to these machines. Lazy processors are documented on the Origin that produce reduced performance statistics. The solution of two problems on an SGI Origin2000, an IBM PowerPC SMP and a Linux cluster demonstrate that the algorithm performs well when applied to the unstructured meshes required for practical engineering analysis. Copyright © 2004 John Wiley & Sons, Ltd.
The perfectly matched layer for the ultra weak variational formulation of the 3D Helmholtz equation
Authors: Huttunen Tomi , Kaipio Jari P. , Monk Peter 
Published: August 2004

AbstractWe investigate the feasibility of using the perfectly matched layer (PML) as an absorbing boundary condition for the ultra weak variational formulation (UWVF) of the 3D Helmholtz equation. The PML is derived using complex stretching of the spatial variables. This leads to a modified Helmholtz equation for which the UWVF can be derived. In the standard discrete UWVF, the approximating subspace is constructed from local solutions of the Helmholtz equation. In previous studies plane wave basis functions have been advocated because they simplify the building of the UWVF matrices. For the PML domain we propose a special set of plane wave basis functions which allow fast computations and efficiently reduce spurious numerical reflections.The method is validated by numerical experiments. In comparison to a low‐order absorbing boundary condition, the PML shows superior performance. Copyright © 2004 John Wiley & Sons, Ltd.
Immigrants, welfare reform, and the economy
Authors: Haider Steven J. , Schoeni Robert F. , Bao Yuhua , Danielson Caroline 
Published: August 2004

AbstractThe welfare reform bill adopted in the United States in 1996 limited the eligibility of immigrants for several government assistance programs, and early projections estimated that nearly half of the savings associated with the reforms would come from these immigrant restrictions. Several studies have found that subsequent program participation declined more for immigrants relative to natives, seemingly verifying the early projections. However, many of these restrictions were either rescinded by the federal government or superceded by state and local policies. In this paper, we first reproduce earlier findings that show the relative declines in program use among immigrants. We then show that much, but not all, of the relative decline in program use among immigrants can be explained by changing macroeconomic conditions. © 2004 by the Association for Public Policy Analysis and Management.
Waiting times for cancer care in Canadian children: Impact of distance, clinical, and demographic factors
Authors: Klein‐Geltink Julia E. , Pogany Lisa M. , Barr Ronald D. , Greenberg Mark L. , Mery Leslie S. 
Published: August 2004

AbstractBackgroundThe objective of this study was to evaluate the impact of distance from residence to pediatric oncology centers on waiting times to diagnostic assessment and treatment in Canadian children with cancer.ProcedureTwo thousand three hundred sixteen children (<15 years of age) captured by the Canadian Childhood Cancer Surveillance and Control Program's (CCCSCP) Treatment and Outcome Surveillance (TOS) system were included in the analysis. The number of days between onset of symptoms and first anti‐cancer therapy was compared for those living less than 25, 25–99, and more than 100 kilometers from their treating center. For each time period, the adjusted odds of falling into the longest time quartiles were estimated using logistic regression analysis.ResultsThirty‐four percent (n = 786) of children lived more than 100 kilometers from their treating center. There were no significant differences in age at diagnosis (P = 0.33), sex (P = 0.68), or ICCC diagnosis (P = 0.02) by distance from center, though there was a significant difference in region of residence (P < 0.01) and the first health care professional contacted (P < 0.01). Except for waiting time from first health care contact to first assessment by treating oncologist which increased with increasing distance (P < 0.01), there were no significant differences in waiting times by distance. When adjusted for important demographic and clinical characteristics, distance to center did not affect the odds of waiting longer for any event.ConclusionsDistance to treating center had no significant impact on waiting times for important diagnostic and treatment events, when adjusted for age at diagnosis, diagnosis, region, and first health care professional seen. © 2004 Wiley‐Liss, Inc.
Evaluation of selective toxicity of five pesticides against Plutella xylostella (Lep: Plutellidae) and their side‐effects against Cotesia plutellae (Hym: Braconidae) and Oomyzus sokolowskii (Hym: Eulophidae)
Authors: Shi Zu‐hua , Guo Shi‐jian , Lin Wen‐cai , Liu Shu‐sheng 
Published: August 2004

AbstractThe toxicities of five pesticides commonly used in vegetable fields to the larvae of the diamondback moth, Plutella xylostella (L) and its two major parasitoids, Cotesia plutellae (Kurdjumov) and Oomyzus sokolowskii (Kurdjumov), were evaluated in the laboratory using several bioassays. When tested at the rates recommended for field application by the manufacturer, fipronil, avermectin and chlorfluazuron produced over 95% mortality on third‐instar larvae of P xylostella, but fenvalerate and methomyl did not produce any substantial mortality to such larvae, and over 70% of P xylostella larvae could still pupate normally after feeding on cabbage leaf treated with the two pesticides. In a residual contact assay with adult parasitoids, fipronil and methomyl caused over 93% mortality within 24 h; fenvalerate killed approximately 55% of the adults within 24 h; avermectin and chlorfluazuron showed differential toxicity to the two parasitoids. Avermectin was extremely harmful to O sokolowskii but slightly toxic to C plutellae, while chlorfluazuron was more toxic to C plutellae than to O sokolowskii. In the residue assay with cocoons of C plutellae and pupae of O sokolowskii developed within P xylostella pupae, treatments with pesticides did not reduce adult emergence. However, the mortality of C plutellae adults emerged from the fipronil‐treated cocoons increased greatly within 24 h post‐emergence; adults from the fenvalerate‐treated cocoons parasitized less host larvae. Treatments with fenvalerate and methomyl significantly increased the mortality of O sokolowskii adults within 24 h post‐emergence. Recommendations of choosing pesticides for the control of P xylostella are given. Copyright © 2004 Society of Chemical Industry
Hydrogen bonding interaction in sarcosine–water complex using ab initio and DFT method
Authors: Chaudhari Ajay , Sahu Prabhat K. , Lee Shyi‐Long 
Published: August 2004

AbstractThe hydrogen bonding interaction in the Sarcosine (N‐methylglycine)–water complex is studied using ab initio, MP2, and density functional theory (DFT/B3LYP). For this complex, binding energies, dipole–dipole interactions, chemical hardness, and chemical potential have been calculated. Three different basis sets, viz. 6‐311+G, 6‐311++G, and 6‐311++G*, have been used to optimize the geometries by all three methods. The basis set superposition errors are also calculated, and the corrected binding energies are reported for this complex. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005