bluuebunny/crossref_metadata_2025_split huggingface dataset:
High temperature organic/inorganic addition cure polyimide composites, part 1: Matrix thermal properties
Authors: Lincoln Jason E. , Hout Sara , Flaherty Kelly , Curliss David B. , Morgan Roger J. 
Published: December 2007

AbstractStructure‐thermal property interrelationships are characterized and reported for organic/inorganic addition cure polyimide composite matrices based on 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, the reactive terminal group 4‐phenylethynyl phthalic anhydride, and stoichiometric controlled diamine ratios of 1,3‐phenylenediamine, 1,4‐phenylenediamine, or 4,4′‐(1,3‐phenylenediisopropylidene) bisaniline, combined with bis(p‐aminophenoxy) dimethyl silane or an α, ω‐bis(3‐aminopropyl) polydimethylsiloxane oligomer. Polymerization of monomer reactants resin solutions, carbon fiber prepregs and composites, and imidized oligomers are characterized to relate molecular chemical structure and morphology to glass transition temperature, processing characteristics, thermodynamic properties, and thermal stability. Glass transition temperature, thermal decomposition temperature, and char yield were found to increase with increasing siloxane block length in the imide backbone. As the concentration of inorganic component in the imide oligomer backbone increased, the cured glass transition temperature decreased. Char yield and thermal decomposition temperature were observed to decrease as the inorganic component concentration increased. Incorporation of bis(p‐aminophenoxy) dimethyl silane into the imide oligomer structure did not provide any significant advantages over traditional polyimides relative to thermal properties or composite processing, but aminosiloxanes improved composite toughness, prepreg tack, and composite processability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
In situ fluorescence spectroscopic studies of polymerization of anaerobic adhesives
Authors: Maandi Eerik , Sung Chong Sook P. 
Published: December 2007

AbstractAnaerobic adhesives cured by a redox initiated free radical mechanism contain acrylate monomers, stabilizers, accelerators, a nonreactive fluorophore used as an inspection aid, and various nonreactive ingredients to modify polymer properties and rheology. Fluorescence spectroscopy has shown that collisional quenching of the fluorophore due to an amine cure‐accelerator is reduced by rising viscosity during polymerization, thus resulting in an increase in fluorescence intensity. By monitoring the changes in fluorescence intensity with an in situ fiber‐optic method, room temperature polymerizations have been characterized both in a model formulation containing only reactive ingredients as well as in a real commercial formulation containing many nonreactive ingredients. The results from this fluorescence method on polymerization monitoring show excellent correlation with the FTIR results. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Interaction of glycyrrhetinic acid, furosemide and hydrochlorothiazide with bovine serum albumin and their displacement interactions: capillary electrophoresis and fluorescence quenching study
Authors: Zhou Neng , Liang Yi‐Zeng , Wang Bing , Wang Ping , Chen Xian , Zeng Mao‐Mao 
Published: December 2007

AbstractLicorice is the most widely used crude drug in traditional Chinese medicine. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizic acid, which is the main bioactive ingredient of licorice. In this work, capillary electrophoresis–frontal analysis (CE–FA) was applied to study the binding of bovine serum albumin with GA and two diuretics: furosemide (FU) and hydrochlorothiazide (HZ). The binding parameters of GA were determined by Scatchard analysis, which showed that there are two kinds of binding sites in bovine serum albumin for GA. However, the results showed that the CE–FA method was not suitable for the interaction study of FU and HZ. Therefore, utracentrifugation–CE was used to probe the binding characteristic of these two drugs and the results showed only one kind of binding site for them under the studied conditions. Displacement interactions between these drugs were also investigated by utracentrifugation–CE method and the results showed that GA hardly displaces HZ while it can slightly displace FU and FU can slightly displace HZ. For comparison, the binding of these drugs was also studied by the fluorescence quenching method and the data were processed by the Stern–Volmer quenching equation. Results showed that the binding constants were basically consistent for two methods for all drugs studied. The number of binding sites on one protein molecule was well consistent for FU and HZ while it was quite different for GA. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of forsythiaside in rat plasma by high‐performance liquid chromatography and its application to pharmacokinetic studies
Authors: Li Yun‐Xia , Jiang Xue‐Hua , Liang Hu‐Yi , Li Xue 
Published: December 2007

AbstractA simple high‐performance liquid chromatographic method was developed to study the pharmacokinetics of forsythiaside in rat plasma after intravenous administration. Hesperidin was used as the internal standard. The drugs were separated on a reversed‐phase C18 column and detected at 332 nm. Good linearity was achieved in the range of 0.067–26.667 µg/mL. The intra‐ and inter‐assay variation coefficients for this analysis were no more than 10.94 and 14.56%, respectively. The average recovery for forsythiaside was 87.42% from plasma. The analytical sensitivity and accuracy of this assay were adequate for characterization of the pharmacokinetics of intravenous administration of forsythiaside to rats and the assay has been successfully applied to provide pharmacokinetic data. The mean t1/2Z was 20.36, 19.40 and 23.62 min for 2, 5 and 20 mg/kg for forsythiaside after i.v. administration, respectively. The AUC0−t increased linearly from 40.64 to 624.14 µg min/mL after administration of the three doses. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative determination of domperidone in human plasma by ultraperformance liquid chromatography with electrospray ionization tandem mass spectrometry
Authors: Xu Dong‐Hang , Lou Hong‐Gang , Yuan Hong , Jiang Bo , Zhou Quan , Zhang Zhong‐Miao , Ruan Zou‐Rong 
Published: December 2007

AbstractA simple and sensitive liquid chromatography–tandem mass spectrometry method was developed and validated for determining domperidone in human plasma. The analyte and internal standard (IS; mosapride) were isolated from plasma samples by protein precipitation with methanol (containing 0.1% formic acid). The chromatographic separation was performed on an Xterra MS C18 Column (2.1 × 150 mm, 5.0 µm) with a gradient programme mobile phase consisting of 0.1% formic acid and acetonitrile at a flow rate of 0.30 mL/min. The total run time was 4.0 min. The analyses were carried out by multiple reaction monitoring using the parent‐to‐daughter combinations m/z 426 → 175 and m/z 422 → 198 (IS). The areas of peaks from the analyte and IS were used for quantification of domperidone. The method was validated according to the FDA guidelines on bioanalytical method validation. Validation results indicated that the lower limit of quantification was 0.2 ng/mL, and the assay exhibited a linear range of 0.2–60.0 ng/mL and gave a correlation coefficient (r2) of 0.999 or better. Quality control samples (0.4, 0.8, 15 and 50 ng/mL) in six replicates from three different analytical runs demonstrated an intra‐assay precision (RSD) 4.43–6.26%, an inter‐assay precision 5.25–7.45% and an overall accuracy (relative error) of <6.92%. The method can be applied to pharmacokinetic and bioequivalence studies of domperidone. Copyright © 2007 John Wiley & Sons, Ltd.
Development and validation of a simple thin layer chromatographic method for the analysis of artemisinin in Artemisia annua L. plant extracts
Authors: Marchand Els , Atemnkeng Magnus A. , Vanermen Stijn , Plaizier‐Vercammen Jacqueline 
Published: December 2007

AbstractOwing to the development of parasite resistance to standard antimalarial treatments like chloroquine and sulfadoxine–pyrimethamine, the demand for Artemisia annua, a key ingredient for new and highly effective antimalarial drugs, is huge. Therefore selective and precise methods to determine the content of artemisinin in dry plant material and in raw impure extracts are needed. In this work a method is described for the clear separation and extraction of artemisinin from other plant components in the Artemisia annua L. plant by thin‐layer chromatography (TLC). To obtain optimal extraction and recovery efficiency, several parameters were evaluted, including choice of extraction solvent, TLC plate type and sensitivity between UV and visible light. Method validation was performed on both the dry plant material and non‐purified plant extracts. Toluene presented the highest extraction efficiency compared with petroleum ether, hexane and methanol. Reversed‐phase plates showed more concentrated spots than normal‐phase plates, while the sensitivity of the analysis in UV was comparable to that in visible light but less precise. The impure plant extracts were analyzed by both TLC and HPLC‐UV at 215 nm and both methods met the requirements for linearity, selectivity, precision and accuracy. Hence, the proposed TLC method can easily be used for both qualitative and quantitative control of the raw plant extract in areas where advanced methods are scarce. Copyright © 2007 John Wiley & Sons, Ltd.
Validation of a fully automated high throughput liquid chromatographic/tandem mass spectrometric method for roxithromycin quantification in human plasma. Application to a bioequivalence study
Authors: Kousoulos Constantinos , Tsatsou Georgia , Dotsikas Yannis , Apostolou Constantinos , Loukas Yannis L. 
Published: December 2007

AbstractA fully automated high‐throughput liquid chromatography/tandem mass spectrometry (LC‐MS/MS) method was developed for the determination of roxithromycin in human plasma. The plasma samples were treated by liquid–liquid extraction (LLE) in 2.2 mL 96‐deep‐well plates. Roxithromycin and the internal standard clarithromycin were extracted from 100 µL of human plasma by LLE, using methylt‐butyl ether as the organic solvent. All liquid transfer steps were performed automatically using robotic liquid handling workstations. After vortexing, centrifugation and freezing, the supernatant organic solvent was evaporated and reconstituted. Sample analysis was performed by reversed‐phase LC‐MS/MS, with positive ion electrospray ionization, using multiple‐reaction monitoring. The method had a very short chromatographic run time of 1.6 min. The calibration curve was linear for the range of concentrations 50.0–20.0 × 103ng mL−1. The proposed method was fully validated and it was proven to be selective, accurate, precise, reproducible and suitable for the determination of roxithromycin in human plasma. Therefore, it was applied to the rapid and reliable determination of roxithromycin in a bioequivalence study afterper osadministration of 300 mg tablet formulations of roxithromycin. Copyright © 2007 John Wiley & Sons, Ltd.
Pyrazolyl–Diamine Ligands That Bear Anthracenyl Moieties and Their Rhenium(I) Tricarbonyl Complexes: Synthesis, Characterisation and DNA‐Binding Properties
Authors: Vitor Rute F. , Correia Isabel , Videira Margarida , Marques Fernanda , Paulo António , Costa Pessoa João , Viola Giampietro , Martins Gabriel G. , Santos Isabel 
Published: December 2007

AbstractTwo novel families of pyrazolyl–diamine ligands that bear an anthracen‐9‐yl group as a DNA‐binding fragment, pz*(CH2)2NH(CH2)2NHCH2‐9‐anthryl (pz*=pz (L1), 3,5‐Me2pz (L2)) and pz*(CH2)2NH(CH2)2NH2 (pz*=4‐(9‐anthrylmethyl)pz (L3), 3,5‐Me2‐4‐(9‐anthrylmethyl)pz (L4)), have been prepared and fully characterised. In the case of L2–L4, the evaluation of their coordination capability towards the fac‐[Re(CO)3]+ core led to the synthesis of the organometallic complexes fac‐[Re(CO)3{3,5‐Me2pz(CH2)2NH(CH2)2NHCH2‐9‐anthryl}]Br (7) and fac‐[Re(CO)3{4‐(9‐anthrylmethyl)pz*(CH2)2NH(CH2)2NH2}]Br (pz*=pz (8), 3,5‐Me2pz (9)). The interaction of the novel pyrazole–diamine ligands and the rhenium(I) complexes with calf thymus (CT) DNA has been investigated with a variety of spectroscopic techniques (UV‐visible, fluorescence, circular dichroism (CD) and linear dichroism (LD)). All of the evaluated compounds have a moderate affinity to CT DNA (3.46×103<Kb<1.95×104), but the binding mode depends on the position of the chromophore in the framework of the pyrazolyl–diamine ligands. LD measurements have shown that L1 and L2 act as DNA intercalators, but complex 7 intercalates only partially. By contrast, the compounds with the anthracenyl group at the 4‐position of the azolyl ring (L3, L4 and 9) do not intercalate, and behave more like DNA groove binders. Fluorescence microscopy studies have demonstrated that complexes 7 and 9 can target the nucleus of murine B16‐F1 melanoma cells, and appear to be promising platforms for the further design of radiopharmaceuticals for targeted radiotherapy.
Polyvinyl‐Locked versus Free Quaterthiophene: Effect of Spatial Constraints on the Electronic Properties ofn‐Hexylquaterthiophene
Authors: Melucci Manuela , Zambianchi Massimo , Zanelli Alberto , Camaioni Nadia , Gazzano Massimo , Bongini Alessandro , Barbarella Giovanna 
Published: December 2007

AbstractA soluble, low‐weight fraction of poly(α‐vinyl,ω‐n‐hexyl‐quaterthiophene), PT4Hex, havingn‐hexylquaterthiophenes as side‐chain groups, is prepared by free‐radical polymerization of α‐vinyl,ω‐n‐hexyl‐quaterthiophene and the corresponding properties compared to those of free di‐n‐hexylquaterthiophene (T4Hex). Optical analysis (absorption and emission) and X‐ray diffraction data indicate that in the polyvinyl‐locked architecture the quaterthiophene pendants adopt a cofacial arrangement with a mutual distance close enough for π–π orbitals to overlap (∼4 Å). As a consequence of the close chain packing, a shift of the reduction potential of about 0.5 V toward less negative values with respect to free T4Hex, is found for PT4Hex films. Due to its enhanced electron affinity, PT4Hex displays an electron‐acceptor behavior when blended with alkylated and silylated quaterthiophenes acting as donors.
A new biomarker for mitotic cells
Authors: Jacobberger James W. , Frisa Phyllis S. , Sramkoski R. Michael , Stefan Tammy , Shults Keith E. , Soni Deena V. 
Published: December 2007

AbstractMany epitopes are phosphorylated during mitosis. These epitopes are useful biomarkers for mitotic cells. The most commonly used are MPM‐2 and serine 10 of histone H3. Here we investigated the use of an antibody generated against a phospho peptide matching residues 774–788 of the human retinoblastoma protein 1 (Rb) to detect mitotic cells. Human cell lines were stained with DNA dyes and antibodies reactive with epitopes defined by antibody MPM‐2, phospho‐S10‐histone‐H3, and the phospho‐serine peptide, TRPPTLSPIPHIPRC (phospho‐S780‐Rb). Immunoreactivity and DNA content were measured by flow and image cytometry. Correlation and pattern recognition analyses were performed on list mode data. Western blots and immunoprecipitation were used to investigate the number of peptides reactive with phospho‐S780‐Rb and the relationship between reactivity with this antibody and MPM‐2. Costaining for bromodeoxyuridine (BrdU) was used to determine acid resistance of the phospho‐S780‐Rb epitope. Cell cycle related phospho‐S780‐Rb immunofluorescence correlated strongly with that of MPM‐2. Laser scanning cytometry showed that phospho‐S780‐Rb immunofluorescence is expressed at high levels on all stages of mitotic cells. Western blotting and immunoprecipitation showed that the epitope is expressed on several peptides including Rb protein. Costaining of BrdU showed that the epitope is stable to acid. Kinetic experiments showed utility in complex cell cycle analysis aimed at measuring cell cycle transition state timing. The phospho‐S780‐Rb epitope is a robust marker of mitosis that allows cytometric detection of mitotic cells beginning with chromatin condensation and ending after cytokinesis. Costaining of cells with DNA dyes allows discrimination and counting of mitotic cells and post‐cytokinetic (“newborn”) cells. To facilitate use without confusion about specificity, we suggest the trivial name, pS780 for this mitotic epitope. © 2007 International Society for Analytical Cytology
The Portuguese short form of the Eating Attitudes Test‐40
Authors: Pereira Ana Telma , Maia Berta , Bos Sandra , Soares Maria João , Marques Mariana , Macedo António , Azevedo Maria Helena 
Published: December 2007

AbstractTo develop a Portuguese short form, the Eating Attitudes Test‐40 (EAT‐40) was administered to a community sample of 922 female students and to a clinical sample of 63 females suffering from an eating disorder. With the EAT responses of the community sample a factor analysis was performed and items with factor loadings ≥ 0.30 were selected. Internal consistency was computed for both the instrument and the factors. To study the discriminant capacity the proportion of symptomatic answers and the mean scores were compared between the clinical (N = 63) and control (N = 63) samples. Three factors were extracted: Drive for Thinness (14 items, α = .839), Bulimic Behaviours (8 items, α = .670), Social Pressure to Eat (3 items, α = .758). The short form is composed of 25 items and shows good internal consistency = 0.839. Symptomatic answers for all items (except one) and total mean scores were significantly higher (p < .001) in the clinical sample than in community sample. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association.
A longitudinal study of perfectionism in adolescent onset anorexia nervosa‐restricting type
Authors: Nilsson Karin , Sundbom Elisabet , Hägglöf Bruno 
Published: December 2007

AbstractThis longitudinal study analyses self‐reported perfectionism, eating disorders and psychiatric symptoms during recovery from anorexia nervosa (AN). With a recovered design, a group of 68 previous patients with AN was studied in two follow‐up studies, 8 and 16 years after 1st admission to Child and Adolescent Psychiatry (CAP). Levels of perfectionism stayed the same while eating disorder symptoms and psychiatric symptoms decreased during recovery. Levels of perfectionism were inversely related to duration of remission so that individuals that had short illness duration had lower levels of perfectionism at both follow‐ups. Patients with initial high levels of perfectionism may be at risk for a long illness duration which we recommend clinicians to acknowledge. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association.
Weathering of granite in Antarctica: II. Thermal stress at the grain scale
Authors: Hall Kevin , Guglielmin Mauro , Strini Andrea 
Published: December 2007

AbstractGranular disintegration has long been recognized and referred to in weathering texts from all environments, including the Antarctic. Despite this universal identification and referral, few to no data exist regarding thermal conditions at this scale and causative mechanisms remain little more than conjecture. Here, as part of a larger weathering study, thermal data of individual grains (using infrared thermometry and ultra‐fine thermocouples) composing a coarse granite, as well as the thermal gradients in the outer 10 cm (using thermistors), were collected from a north‐facing exposure. Measurements were also made regarding the surface roughness of the rock. Based on recorded temperatures, the nature of the rock surface and the properties of the minerals, an argument is made for complex stress fields that lead to granular disintegration. Mineral to mineral temperature differences found to occur were, in part, due to the changing exposure to solar radiation through the day (and through seasons). Because the thermal conductivity and the coefficient of thermal expansion of quartz are not equal in all directions, coupled with the vagaries of heating, this leads to inter‐granular stresses. Although fracture toughness increases with a decrease in temperature, it is suggested that the tensile forces resulting from falling temperatures are able to exceed this and produce granular disassociation. The lack of equality with respect to crystal axis of both thermal conductivity and expansion in quartz further exacerbates the propensity to failure. Grain size and porosity also influence the thermal stresses and may help explain why some grains are held in place despite disassociation near the surface. While the data presented here appear to beg more questions than providing answers, they do provide a basis for better, more detailed studies of this important weathering scale. Copyright © 2007 John Wiley & Sons, Ltd.
Weathering of granite in Antarctica: I. Light penetration into rock and implications for rock weathering and endolithic communities
Authors: Hall Kevin , Guglielmin Mauro , Strini Andrea 
Published: December 2007

AbstractWhere rocks are composed of translucent minerals, light penetrates the rock and, in so doing, impacts on the thermal conditions. Where minerals are not translucent all the heat transformation must be at the rock surface, and steep thermal gradients can occur. Where light does penetrate, a component of the incoming radiation is transformed to heat at differing depths within the rock, thereby decreasing the thermal gradient. Equally, light transmissive minerals facilitate endolithic communities, which can also play a role in rock weathering. The attribute of light transmission within rock and the impact this has on the resulting thermal conditions has not been considered within rock weathering studies. An attempt was made to monitor the amount of light penetrating the outer 2 mm of coarse granite under Antarctic summer conditions and to evaluate the thermal impact of this. It was found that the amount of light penetration at this site exceeded modeled or postulated values from biological studies and that it could significantly impact the thermal conditions within the outer shell of the rock. Although the resulting data highlighted a number of flaws in the experimental procedure, sufficient information was generated to provide the first assessment of the range of thermal responses due to light transmissive minerals in rock. Copyright © 2007 John Wiley & Sons, Ltd.
Correlated observation errors in data assimilation
Authors: Stewart L. M. , Dance S. L. , Nichols N. K. 
Published: December 2007

AbstractData assimilation provides techniques for combining observations and prior model forecasts to create initial conditions for numerical weather prediction (NWP). The relative weighting assigned to each observation in the analysis is determined by its associated error. Remote sensing data usually has correlated errors, but the correlations are typically ignored in NWP. Here, we describe three approaches to the treatment of observation error correlations. For an idealized data set, the information content under each simplified assumption is compared with that under correct correlation specification. Treating the errors as uncorrelated results in a significant loss of information. However, retention of an approximated correlation gives clear benefits. Copyright © 2007 John Wiley & Sons, Ltd.