bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization and Properties of Novel Polyurethanes Based on the Chain Extender Ethylene Glycol and Aromatic Diisocyanates of Variable Flexibility
Authors: Prisacariu Cristina , Scortanu Elena 
Published: August 2007

AbstractSummary: Novel polyurethane elastomers (PUs) were synthesized with ethylene glycol (EG) as a chain extender. The macrodiol was poly(ethylene adipate) (PEA), MW = 2000 ± 50. Two isocyanates were employed: 4,4′‐methylene bis(phenyl isocyanate) (MDI) and 4,4′‐dibenzyl diisocyanate (DBDI). The conformational mobility of DBDI causes an unusually wide range of mechanical, physical and chemical properties, associated with the possibility of pronounced phase separation into a domain – matrix morphology, and with a higher tendency to crystallization and self‐association by hydrogen bonding. Materials were characterized by wide angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), dynamic mechanical analyses (DMA), and mechanical measurements. Results were discussed in terms of the effect of PUs crystallinity. In the case where the chain extender–diisocyanate couple was EG‐DBDI, the hard segments were observed to crystallize. The DBDI based PUs displayed higher flow stress in the hard phase caused by stronger phase segregation.
Synthesis, Characterization of Copper‐Loaded Carboxymethyl‐Chitosan Nanoparticles with Effective Antibacterial Activity
Authors: Gu Chunju , Sun Bin , Wu Wenhua , Wang Fengchuan , Zhu Meifang 
Published: August 2007

AbstractSummary: Copper‐loaded carboxymethyl‐chitosan (CMCS‐Cu) nanoparticles were successfully prepared by chelation under aqueous conditions. The effect of degree of deacetylation and substitution, the molecular weight of CMCS, CMCS concentration, Cu(II) ions concentration, pH value of the solution, as well as temperature, on the morphology of the yielded particles were systematically investigated. The physicochemical properties of the particles were determined by size and zeta potential analysis, FTIR analysis, DLS, TEM, SEM and XRD pattern. FTIR and XRD revealed that Cu (II) ions and CMCS formed a chelate complex. The size of CMCS‐Cu particles shows a good consistency by DLS, TEM, and SEM. The nanoparticles with the size of about 70 nm have been prepared at 0.13 wt% CMCS, 16 mmol/L Cu(II) ions, pH value 4.56 at 25 °C. The antibacterial activity of CMCS, CMCS‐Cu normal particles with the size of about 1000 nm and CMCS‐Cu nanoparticles with the size of less than 100 nm against Staphylococcus aureus was evaluated by vibration method. Results show that the antibacterial efficiency of nanoparticles reached 99%, which is much more efficient than 68.9% of the normal one and 6.1% of CMCS. CMCS‐Cu nanoparticles were proved to be a good novel antibacterial material.
Functional Opals from Reactive Polymers: Complex Structures, Sensors, and Modified Photoluminescence
Authors: Fleischhaker Friederike , Lange Birger , Zentel Rudolf 
Published: August 2007

AbstractSummary: This paper describes the synthesis and properties of functional opal structures, so‐called colloidal photonic crystals (CPCs), from a variety of reactive polymers. Photoprocessable opals are presented as well as opals with incorporated “smart” defect layers that can be actively addressed by external stimuli. In addition, opals with functional bio‐macromolecular defects have been developed. They present a new class of materials for optical biomonitoring through shifts of the induced photonic defect mode. Strong modification of photoluminescence according to the photonic bandstructure is observed from opals with embedded exclusively luminescent defect layer.
Formation of Hollow Polymeric Microspheres with Functionalized Surface on the Basis of Latex Particles with Multilayered Structure
Authors: Shevchuk Oleh , Tokarev Viktor , Bukartyk Natalya , Voronov Stanislav 
Published: August 2007

AbstractSummary: Latices with “core‐shell” particle morphology containing polar “core” and a shell on the basis of copolymer of styrene and functional vinyl monomer (allyl alcohol, vinyl acetate, methacrylic acid) has been obtained as a result of graft‐copolymerization initiated from the surface of (meth)acrylate latex particles previously modified with functional polyperoxides. The processes of functional shell grafting as well as the processes of latex particle swelling with obtaining hollow microspheres due to neutralization of core carboxylic groups have been studied.
Temperature and pH‐Sensitive Polymers with Hydrophobic Spacers for the Controlled Delivery of Drugs
Authors: Licea‐Claveríe Angel , Cornejo‐Bravo José Manuel , Salgado‐Rodríguez Rodolfo , Santos‐Rosas Dolores del Rosario , Lugo‐Medina Eder , Ramos‐Ibarra Marco Antonio , Arndt Karl‐Friedrich 
Published: August 2007

AbstractSummary: Acid methacrylates containing hydrophobic aliphatic and aromatic spacers were used to prepare pH‐sensitive ampholytic hydrogels and bidimensional temperature‐ (T) and pH‐sensitive hydrogels. Their swelling behaviour was studied by changing the pH and temperature of buffer solutions. Salicylamide, salicylic acid and green fluorescent protein (GFP) as model drugs were loaded into the gels and their release kinetics studied under simulated gastric and intestinal conditions. T‐ and pH‐sensitive hydrogels containing aliphatic spacers show sustained release of analgesics depending on pH (e.g. 7.4); while longer aliphatic spacers resulted in drug release depending on pH and temperature (T < transition T). GFP was released from temperature‐ and pH‐sensitive ampholytic hydrogels after different lag times depending on hydrogel composition.
Application of Polyelectrolytic Temperature‐Responsive Hydrogels in Chemical Sensors
Authors: Guenther Margarita , Gerlach Gerald , Corten Cathrin , Kuckling Dirk , Muller Martin , Shi Zhangman , Sorber Joerg , Arndt Karl‐Friedrich 
Published: August 2007

AbstractSummary: A rapidly expanding field of on‐line process monitoring and on‐line control in biotechnology, food industry, pharmaceutical industry, process chemistry, environmental measuring technology, water treatment and sewage processing requires the development of new micro fabricated reliable chemical and biosensors that are specific for particular species and can attain the analytic information in a faster, simpler and cheaper manner. Using a functionalised polymer coating in sensors provides the possibility to detect, transmit and record the information regarding the concentration change or the presence of a specific analyte (a chemical or biological substance that needs to be measured) by producing a signal proportional to the concentration of the target analyte. However, the sensor response time and signal reproducibility are limited by the visco‐elastical and hysteresis behaviour of the polymer material. We propose some methods improving the properties of the chemical sensors on the basis of thermo‐shrinking N‐isopropylacrylamide (NIPAAm) copolymer gels.
Controlled Thermosensitivity of the Poly(N‐isopropyl‐ acrylamide‐co‐N,N′‐dimethyl(methacryloyloxyethyl)‐ ammonium propane sulfonate) Hydrogels
Authors: Kamenova Irena , Kuckling Dirk , Georgiev George , Adler Hans‐Jurgen P. 
Published: August 2007

AbstractSummary: The N‐isopropylacrylamide (NIPAM) and N,N′‐dimethyl‐(methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) copolymer networks having monomer units with an opposite thermoassembling ability are synthesized and analyzed. The network composition is of crucial importance for their degree of swelling (Q) and Q‐Temperature (T) dependences. After the Q normalization these dependences outline two classes of networks which hydrogels expel or imbibe water with T. The boundary network (with 0.39 mole fraction of DMAPS monomer units) defines a critical T (Tcr) at which Q is the same as that at the initial T (To), but with a structure organization, different than that at To. The hydrogels thermoreversibility at the stepped T change, and the salt effect on the Q‐T dependences are demonstrated also.
Mechanical Properties and Phase Transition of High Clay Content Clay/Poly(N‐isopropylacrylamide) Nanocomposite Hydrogel
Authors: Liu Yang , Zhu Meifang , Liu Xiaoli , Jiang Y.M. , Ma Y. , Qin Z.Y. , Kuckling Dirk , Adler Hans‐Jurgen P. 
Published: August 2007

AbstractSummary: A series of high clay content Clay‐S/PNIPAAm nanocomposite hydrogels (S‐N gels) has been successfully prepared by in situ polymerization. Their mechanical properties and phase transition behavior has been systematically investigated. It was found that S‐N gels show high tensile strength, high elongation at break, fast stress relaxation, high hysteresis, and poor resilience, which may be ascribed to the hydrophilicity and flexibility of PNIPAAm chains. It was also concluded that the macroscopic phase transition behavior of S‐N gels depend on the ratio of Segments II (thermosensitive segments) to Segments I (non‐thermosensitive segments).
Temperature Sensitive Hydrogels Based on Hydroxypropylcellulose by High Energy Irradiation
Authors: Gottlieb Ronny , Kaiser Claudia , Gohs Uwe , Arndt Karl‐Friedrich 
Published: August 2007

AbstractSummary: Stimuli sensitive hydrogels change their properties in dependence on a liquid environment. The temperature sensitive hydroxypropylcellulose (HPC) gel shows a volume phase transition in water at about 48 °C. For different applications a crosslinking of a preformed layer of the dry polymer on a support is necessary. It is known, that HPC dissolved in water is crosslinkable by high energy irradiation (electron beam). Now, we could show, that HPC can be crosslinked in the dry state by high energy irradiation. This allows the preparation of thin crosslinked layers of HPC on silicone substrates.
Elongational Viscosity and Foaming Behavior of PP Modified by Electron Irradiation or Nanotube Addition
Authors: Pötschke Petra , Krause Beate , Stange Jens , Munstedt Helmut 
Published: August 2007

AbstractSummary: In this study, two different routes were chosen which are expected to influence the elongational viscosity and, thus, the foaming behavior of polypropylene (PP). Electron irradiation of a linear PP was performed at room temperature using different doses. Enhanced long‐chain branching was observed with increased irradiation dose. In addition, a linear PP was filled with 5 wt% multiwalled carbon nanotubes (MWNT) by melt mixing at 200 °C. These modified PP materials were investigated with respect to their shear and elongational behavior. After foaming, irradiated PP led to an expansion factor which is about 60% higher than that of the non‐irradiated product. In case of PP filled with 5 wt% MWNT the value of the expansion factor is about 70% higher than that of pure PP expanded under the same conditions. The cell structure is much finer in both cases as compared to unmodified PP.
Polyurethane‐Based Extended Release Form of Piroxicam
Authors: Grigorieva Maya , Zakashun Tetyana , Galatenko Natalia 
Published: August 2007

AbstractSummary: The anti‐inflammatory effect of piroxicam (Px) immobilized on a polyurethane (PU) matrix was studied in vivo by measuring levels of t‐methylimidazole acetic acid (t‐MeImAA) in urine of experimental animals. Released into body from the polymeric matrix, Px affected inflammation process, significantly reducing the t‐MeImAA levels. The retention of Px within the PU/drug system – largely due to physical modification of the polymer – resulted in durable therapeutic action of the system.
Geometric T–Ω approach to solve eddy currents coupled to electric circuits
Authors: Specogna Ruben , Suuriniemi Saku , Trevisan Francesco 
Published: August 2007

AbstractThis paper describes a systematic geometric approach to solve magneto‐quasi‐static coupled field–circuit problems. The field problem analysis is based on formulating the boundary value problem with an electric vector potential and a scalar magnetic potential. The field–circuit coupling and the definition of potentials are formally examined within the framework of homology theory. Copyright © 2007 John Wiley & Sons, Ltd.
Human rights and development: the case of local government transformation in South Africa
Authors: van Rensburg Linda Jansen , Naudé Wim 
Published: August 2007

AbstractLocal governments throughout the world are assuming a more important role in economic development of their communities as an increasing number of governments begin to decentralise powers and functions. As these lower levels of government seek sustainable local economic development (LED) strategies the human rights approach towards development becomes pertinent as globalisation accelerates. This article proposes an emphasis on socio‐economic rights as the basis for sustainable LED in developing countries. The article is based on the experience of South African local government in the period after 1994, leading up to the first democratic local government elections on 5 December 2000. Proceeding from the view that the promotion of human rights is necessary for the promotion of economic development, the article critically assesses the role of local government in the promotion of LED through a rights‐based approach. It is argued that the identification in the South African Constitution of local government with basic service provision (recently emphasised by a Constitutional court judgement) will place socio‐economic rights at the centre of LED strategies in South Africa. It is argued that this is indeed the most appropriate cornerstone of LED in South Africa. However, the transformation process that leads the country towards its progressive Constitution needs to be maintained and this article identifies five broad areas for transformation that may still be needed to entrench an adequate human rights culture within the sphere of local governance. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative proteomic approaches for biomarker discovery
Authors: Hu Zhiyuan , Hood Leroy , Tian Qiang 
Published: August 2007

AbstractThe rapid advances in proteomic technologies have made possible systematic analysis of hundreds to thousands of proteins in clinical samples with the promise of uncovering novel protein biomarkers for various disease conditions. We will discuss in this review article current MS and protein chip‐based quantitative proteomic approaches and their application in biomarker discovery. The emphasis will be placed on new quantification strategies employing stable isotopic labeling coupled with MS/MS, and antibody‐based protein chips and nanodevices. The strength and weakness of each technology are briefly highlighted.
Clinical application of tear proteomics: Present and future prospects
Authors: Wu Kaili , Zhang Yanli 
Published: August 2007

AbstractHuman tear fluid is charactered with very small volume and complex protein constitutes with a very large orders of magnitude. The tear proteome analysis provides a unique dataset (i.e., specific protein markers or protein patterns) that may be correlated to more effective diagnosis, prognosis, and response to therapy. Compared to less than 100 tear proteins obtained by the traditional methods, more than 400 proteins have been found in human tear fluid by current proteomic technologies. Many proteomics techniques, such as 2‐DE, MALDI‐TOF‐MS, LC‐MS, SELDI‐TOF‐MS, protein arrays, have been used to perform tear proteome analysis in healthy and/or disease subjects. The clinical application of tear proteomics needs suitable tear collection methods, standard tear handling procedures, and more sensitive and reliable proteomic technologies.
Unconditionally stable perfectly matched layer boundary conditions
Authors: De Raedt H. , Michielsen K. 
Published: August 2007

AbstractA brief review is given of a systematic, product‐formula based approach to construct unconditionally stable algorithms for solving the time‐dependent Maxwell equations. The fundamental difficulties that arise when we want to incorporate uniaxial perfectly matched layer boundary conditions into this scheme is discussed. We construct an algorithm that circumvents these difficulties and is unconditionally stable. Results of simulations for a point source and a plane current source inside a three‐dimensional volume illustrate that in practice, the algorithm performs as theoretically expected. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Erratum: Predicting the morphological and hydraulic consequences of river rehabilitation
Authors: Schweizer S. , Borsuk M. E. , Reichert P. 
Published: August 2007

AbstractErratum: Predicting the Morphological and Hydraulic Consequences of River Rehabilitation. S. Schweizer, M. E. Borsuk and P. Reichert. River Research and Applications (23)3: 303–322.Equation 17 on page 313 should read $r={{e \cdot \theta ^{\,0.5}} \over {\left( {{{d_{10} } \over {d_m }}} \right)^{3.5} \cdot {\mathop{\rm Re}\nolimits} _f {\hskip -.1pt} ^{1.5} \cdot i^{\,0.67} }}$ and not $r={{e \cdot \theta ^{\,0.5} } \over {\left( {{{d_{10} } \over {d_m }}} \right)3.5 \cdot {\mathop{\rm Re}\nolimits} _f ^{15} \cdot i^{\,0.67} }}$ as published.
Impact of weirs on fish communities in a piedmont stream
Authors: Poulet N. 
Published: August 2007

AbstractThe impact of large dams on fish communities is much better documented than that of weirs. This paper investigates the influence of weirs on fish community patterns along a piedmont river (the River Viaur). Presence/absence of species was obtained distant from a weir (NW), and immediately downstream (DW) and immediately upstream (UW) of the weir. More than half of the species captured were non‐native, probably introduced when upstream reservoirs were built. Most of these species were eurytopic or limnophilic. Species richness at UW sites and the number of introduced species found at each site did not depend on the distance from the source (DFS). UW sites had more introduced and limnophilic species than NW sites. Conversely, NW had more rheophilic species than UW. Furthermore, total species richness (SRT) was higher at DW than NW suggesting a direct influence of the weir on the downstream community. UW sites were characterized by the presence of tench, roach and bleak which were scarce in NW sites where brown trout predominated. Weirs appear to modify habitat to favour the colonization of introduced species, and therefore have influenced the structure of fish communities. The study underlines the importance of local conditions in artificially‐influenced rivers. Copyright © 2007 John Wiley & Sons, Ltd.
Variables related to stress‐related growth among Turkish breast cancer patients
Authors: Karanci Ayşe Nuray , Erkam Asli 
Published: August 2007

AbstractThe present study aimed to examine the validation of the use of the stress‐related growth scale and the variables related to stress‐related growth among Turkish breast cancer patients. Participants were 90 breast cancer patients. Consistent with the literature, results revealed that both social support and problem‐solving coping strategies related to higher levels of stress‐related growth. Furthermore, income level of the participants and depression scores were also found to be associated with stress‐related growth. From these variables, social support and problem‐solving coping were found to be positively associated with stress‐related growth whereas income level and depression scores were found to be negatively associated with stress‐related growth. These findings were discussed in the light of relevant literature. Copyright © 2007 John Wiley & Sons, Ltd.
Starch Functionalized by Chloroacetate Groups: Coupling of Bioactive Salicylic Acid
Authors: Jantas Roman , Draczyński Zbigniew , Stawski Dawid 
Published: August 2007

AbstractStarch partially functionalized with chloroacetate groups was obtained by reaction of starch with chloroacetyl chloride using the N,N‐dimethylacetamide/5%lithium chloride system as solvent and pyridine as catalyst. The coupling of salicylic acid to starch functionalized with chloroacetate groups was carried out by reaction with the sodium salt of salicylic acid. The structures of chloroacetylated starch and starch‐salicylic acid adducts were determined by means of FTIR, 1H‐NMR and 13C‐NMR spectra. The degree of substitution per anhydroglucose unit (AGU) of chloroacetylated starch was calculated from the chloride content and ranged from 0.52 to 2.34, depending on the ratio of chloroacetyl chloride to starch. The hydrolysis of starch‐salicylic acid adducts in a heterogeneous phase showed that the release of sodium salicylate from tablets is dependent on the hydrophilic character of the adduct and on the pH value of the medium.
Placental vascularization measured by three‐dimensional power Doppler ultrasound at 11 to 13 + 6 weeks' gestation in normal and aneuploid fetuses
Authors: Rizzo G. , Capponi A. , Cavicchioni O. , Vendola M. , Arduini D. 
Published: August 2007

AbstractObjectiveTo establish the potential role of three‐dimensional (3D) power Doppler evaluation of the placental circulation in aneuploidy screening at 11 to 13 + 6 weeks of gestation.Methods3D power Doppler ultrasound examination of the placenta was performed in 25 pregnancies with fetuses with abnormal karyotype and in 100 control pregnancies at 11 to 13 + 6 weeks of gestation. Using the same pre‐established settings for all cases, the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated for the whole placenta.ResultsIn the chromosomally normal group all the vascular indices increased significantly with advancing gestation between 11 and 13 + 6 weeks (VI: r = 0.482, P < 0.001; FI: r = 0.295, P = 0.0029; VFI, r = 0.484, P < 0.001). In the chromosomally abnormal group, the flow indices were not significantly different from normal in cases with trisomy 21 (13 cases), but they were significantly reduced compared with normal in cases with trisomies 13 and 18 (VI: t = 8.321, P < 0.0001: FI: t = 12.934, P < 0.0001; VFI: t = 7.608, P < 0.0001).Conclusions3D power Doppler evaluation of the placental circulation is not useful in screening for trisomy 21, and unlikely to further increase the already high detection rate for trisomies 13 and 18. However, we provide normal ranges of placental vascular indices between 11 + 0 and 13 + 6 weeks of gestation, which may be useful in future research on placental vascularity in certain at‐risk pregnancies. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Congenital adrenal hyperplasia: Diagnostic advances
Authors: Torresani T. , Biason‐Lauber Anna 
Published: August 2007

SummaryCongenital adrenal hyperplasia is a group of autosomal recessive disorders resulting from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex. The most frequent is steroid 21‐hydroxylase deficiency, accounting for more than 90% of cases. Much has been learned about the genetics of the various clinical forms of 21‐hydroxylase deficiency, and correlations between the genotype and the phenotype have been studied extensively. Gene‐specific diagnosis is now feasible and neonatal screening and prenatal treatment have been widely implemented. This discussion will be limited to the most common form of congenital adrenal hyperplasia, with focus on the diagnostic advances in this disease.