bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of clay addition on the morphology and thermal behavior of polyamide 6
Authors: Li Ting‐Cheng , Ma Jianhua , Wang Min , Tjiu Wuiwui Chauhari , Liu Tianxi , Huang Wei 
Published: October 2006

AbstractThe nanostructure, morphology, and thermal properties of polyamide 6 (PA6)/clay nanocomposites were studied with X‐ray scattering, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The wide‐angle X‐ray diffraction (WAXD) and TEM results indicate that the nanoclay platelets were exfoliated throughout the PA6 matrix. The crystallization behavior of PA6 was significantly influenced by the addition of clay to the polymer matrix. A clay‐induced crystal transformation from the α phase to the γ phase for PA6 was confirmed by WAXD and DSC; that is, the formation of γ‐form crystals was strongly enhanced by the presence of clay. With various clay concentrations, the degree of crystallinity and crystalline morphology (e.g., spherulite size, lamellar thickness, and long period) of PA6 and the nanocomposites changed dramatically, as evidenced by TEM and small‐angle X‐ray scattering results. The thermal behavior of the nanocomposites was investigated with DSC and compared with that of neat PA6. The possible origins of a new clay‐induced endothermic peak at high temperature are discussed, and a model is proposed to explain the complex melting behavior of the PA6/clay nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1191–1199, 2007
Epicardium‐derived cells are important for correct development of the Purkinje fibers in the avian heart
Authors: Eralp Ismail , Lie‐Venema Heleen , Bax Noortje A.M. , Wijffels Maurits C.E.F. , Van Der Laarse Arnoud , Deruiter Marco C. , Bogers Ad J.J.C. , Van Den Akker Nynke M.S. , Gourdie Robert G. , Schalij Martin J. , Poelmann Robert E. , Gittenberger‐De Groot Adriana C. 
Published: October 2006

AbstractDuring embryonic development, the proepicardial organ (PEO) grows out over the heart surface to form the epicardium. Following epithelial‐mesenchymal transformation, epicardium‐derived cells (EPDCs) migrate into the heart and contribute to the developing coronary arteries, to the valves, and to the myocardium. The peripheral Purkinje fiber network develops from differentiating cardiomyocytes in the ventricular myocardium. Intrigued by the close spatial relationship between the final destinations of migrating EPDCs and Purkinje fiber differentiation in the avian heart, that is, surrounding the coronary arteries and at subendocardial sites, we investigated whether inhibition of epicardial outgrowth would disturb cardiomyocyte differentiation into Purkinje fibers. To this end, epicardial development was inhibited mechanically with a membrane, or genetically, by suppressing epicardial epithelial‐to‐mesenchymal transformation with antisense retroviral vectors affecting Ets transcription factor levels (n = 4, HH39‐41). In both epicardial inhibition models, we evaluated Purkinje fiber development by EAP‐300 immunohistochemistry and found that restraints on EPDC development resulted in morphologically aberrant differentiation of Purkinje fibers. Purkinje fiber hypoplasia was observed both periarterially and at subendocardial positions. Furthermore, the cells were morphologically abnormal and not aligned in orderly Purkinje fibers. We conclude that EPDCs are instrumental in Purkinje fiber differentiation, and we hypothesize that they cooperate directly with endothelial and endocardial cells in the development of the peripheral conduction system. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Lower prevalence of chondrocalcinosis in Chinese subjects in Beijing than in white subjects in the United States: The Beijing Osteoarthritis Study
Authors: Zhang Yuqing , Terkeltaub Robert , Nevitt Michael , Xu Ling , Neogi Tuhina , Aliabadi Piaran , Niu Jingbo , Felson David T. 
Published: October 2006

AbstractObjectiveChondrocalcinosis, which can promote joint inflammation and cartilage degeneration, is highly prevalent in elderly white subjects. Data on its prevalence are scarce in other ethnic populations. This study was undertaken to compare the prevalence of chondrocalcinosis in Chinese subjects with that in white subjects.MethodsWe recruited a random sample of Beijing residents ages ≥60 years. Participants underwent standard weight‐bearing anteroposterior knee radiography and posteroanterior hand radiography using the protocols developed in the Framingham Osteoarthritis Study. Radiographic chondrocalcinosis was defined as present in a knee or wrist when there was evidence of definite linear cartilage calcification. We compared the prevalence of chondrocalcinosis in Chinese subjects with that in white subjects using age‐standardized prevalence ratios. We used identical methods to collect samples of tap water from 2 cities and measured their levels of calcium, magnesium, and phosphate in the same laboratory.ResultsChinese subjects had a much lower prevalence of knee chondrocalcinosis (1.8% in men, 2.7% in women) than did white subjects (6.2% in men, 7.7% in women), with the age‐standardized prevalence ratio being 0.34 (95% confidence interval [95% CI] 0.20–0.54) and 0.43 (95% CI 0.31–0.59) in men and women, respectively. Wrist chondrocalcinosis was rare in elderly Chinese subjects (prevalence 0.3% in men and 1.0% in women), with the age‐standardized prevalence ratio being 0.06 (95% CI 0.01–0.18) in Chinese men and 0.18 (95% CI 0.10–0.30) in Chinese women. Calcium levels in the tap water in Beijing were 15‐fold higher than in Framingham, whereas no difference was found in magnesium and phosphate levels.ConclusionKnee chondrocalcinosis and wrist chondrocalcinosis are far less common in Chinese subjects in Beijing than in US white subjects in Framingham, Massachusetts. Given the current lack of understanding of the etiology of chondrocalcinosis, further epidemiologic studies of the impact of genetic and environmental factors on occurrence of chondrocalcinosis are indicated.
Increased serum levels of soluble fractalkine (CX3CL1) correlate with disease activity in rheumatoid vasculitis
Authors: Matsunawa Mizuho , Isozaki Takeo , Odai Tsuyoshi , Yajima Nobuyuki , Takeuchi Hiroko T. , Negishi Masao , Ide Hirotsugu , Adachi Mitsuru , Kasama Tsuyoshi 
Published: October 2006

AbstractObjectiveTo determine levels of soluble fractalkine (sFkn) in rheumatoid arthritis (RA) patients with and without rheumatoid vasculitis (RV), and to assess the relationship of sFkn levels to disease activity.MethodsSerum was obtained from 98 RA patients (54 without vasculitis, 36 with extraarticular manifestations but without histologically proven vasculitis, and 8 with histologically proven vasculitis) and from 38 healthy individuals. Levels of sFkn were measured by enzyme‐linked immunosorbent assay. Expression of Fkn and CX3CR1 was quantified by real‐time polymerase chain reaction. Vasculitis disease activity was assessed using the Birmingham Vasculitis Activity Score and the Vasculitis Activity Index.ResultsSerum sFkn levels were significantly higher in patients with RA than in controls and were significantly higher in RA patients with RV than in those without vasculitic complications. Statistically significant correlations were observed between serum sFkn levels in RA patients and levels of C‐reactive protein, rheumatoid factor, immune complex, and complement. In the RV group, sFkn levels also correlated with disease activity. Immunohistochemical analysis indicated that Fkn levels were associated mainly with endothelial cells in vasculitic arteries. In addition, expression of CX3CR1 messenger RNA was significantly greater in peripheral blood mononuclear cells from patients with active RV than in those from other RA patients or controls. Notably, serum sFkn levels were significantly diminished following successful treatment and clinical improvement.ConclusionThese findings suggest that Fkn and CX3CR1 play crucial roles in the pathogenesis of RV and that sFkn may serve as a serologic inflammatory marker of disease activity in RA patients with vasculitis.
A rapid liquid chromatography–tandem mass spectrometry method for quantification of a biologically active molecule camboginol in the extract of Garcinia cambogia
Authors: Chattopadhyay Sunil K. , Kumar Satyanshu 
Published: November 2006

AbstractA liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the determination of camboginol in the extract of fruit rinds of Garcinia cambogia has been developed. Separation was achieved isocratically on an RP C18 column using a solvent system consisting of a mixture of acetonitrile–water (9:1) and methanol–acetic acid (99.5:0.5) in the ratio of 30:70 as mobile phase at a flow rate of 0.4 mL/min. A multiple reaction monitoring (MRM) method was developed for quantification of camboginol in the fruit rinds extract of G. cambogia using MRM transitions of m/z 601.4 → m/z 176.7 and m/z 601.4 → m/z 448.9, respectively. The calibration curve based on peak area against concentration was linear up to 50 ng/mL with a detection limit of 0.5 ng/mL. The method showed satisfactory reproducibility with a coefficient of variation of less than 6%. The method was successfully applied for quantification of camboginol in different Garcinia extracts. Copyright © 2006 John Wiley & Sons, Ltd.
Interplay Between Cation–π, Anion–π and π–π Interactions
Authors: Quiñonero David , Frontera Antonio , Garau Carolina , Ballester Pablo , Costa Antoni , Deyà Pere M. 
Published: October 2006

AbstractThe interplay between three important noncovalent interactions involving aromatic rings is studied by means of high level ab initio calculations. They demonstrate that very strong synergic effects are present in complexes where either cation–π or anion–π and π‐‐π interactions coexist. These strong synergic effects have been studied using the “atoms in molecules” theory and the physical nature of the interactions investigated by means of the molecular interaction potential with polarization (MIPp).
Determination of Aluminum by Adsorptive Cathodic Stripping Voltammetry with 1,2‐Dihydroxyanthraquinone‐3‐Sulfonic Acid (DASA): Effect of Thin Mercury Film Electrode
Authors: Thomas Shaun D. , Davey David E. , Mulcahy Dennis E. , Chow Christopher W. K. 
Published: November 2006

AbstractAn analytical technique for aluminum (Al) based upon the complexation reaction between Al and the ligand – DASA (1,2‐dihydroxy‐anthraquinone‐3‐sulfonic acid) has previously been implemented successfully at the hanging mercury drop electrode (HMDE). There are several advantages of using mercury film electrodes (TMFE) over the HMDE, particularly if disposal of mercury is of concern. The novelty of using TMFE for adsorptive cathodic stripping voltammetry (ACSV) of Al – DASA is demonstrated in this paper. The peak potential used for the detection of Al in this system was at −1.15 V (vs. Ag/AgCl). The method produced a limit of detection (LOD) of 1 μM (n=5) and a linear working range of 1–20 μM Al. Atomic force microscopy methods were used to investigate the nature of the TMFE and its interaction with DASA. The mercury droplets on the TMFE have a limited volume and this may lead to overloading of the electrode at relatively low concentrations of DASA. Interferences from Fe, Ca, Zn and Mg were investigated with only Fe appearing to interfere with the Al‐DASA system. Two masking agents (o‐phenanthroline and 2,2′‐bipyridyl) were shown to be effective at preventing the Fe interference.
Nickel Hexacyanoferrate‐Based Sensor Electrode for the Detection of Nitric Oxide at Low Potentials
Authors: Krylov Andrey V. , Lisdat Fred 
Published: November 2006

AbstractRecently transition metal hexacyanoferrates, analogues of Prussian Blue, have found application in electroanalysis for the detection of biologically relevant species. Our study describes the development of a novel electrode based on nickel hexacyanoferrate (NiHCF) for the sensorial NO determination. A NiHCF layer was deposited on platinum by cyclic voltammetry in a solution of nickel (II) chloride and potassium hexacyanoferrate (III). The electrode was found to be active for NO reduction. The interaction with the radical was studied voltammetrically within the range from 0 V up to +0.4 V vs. Ag/AgCl/1 M KCl. The most appropriate potential for an amperometric detection was determined to be +0.25 V due to the advantageous signal/noise ratio. The sensitivity of the electrodes was found to be 2.0–2.3 A M−1 cm−2. The sensor response of the most important interferents for NO analysis, hydrogen peroxide, ascorbic acid and nitrite, was measured and determined to be sufficiently low.
Screening of drug metabolism by CE
Authors: Zhang Jie , Lou Yijia , Hoogmartens Jos , Van Schepdael Ann 
Published: November 2006

AbstractThe use of CE for rapid assessment of metabolic stability of drugs with cytochrome P450 (CYP) enzymes, based on relative rates of reduced nicotinamide adenine dinucleotide phosphate (NADPH) consumption and nicotinamide adenine dinucleotide phosphate (NADP) production, was investigated. The separation conditions were as follows: capillary, 80.5 cm (75 µm id, 72 cm effective length for UV detection, 58 cm effective length for fluorescence detection); 25 mM sodium phosphate buffer (pH 8.8); 28 kV (80 µA) applied voltage; UV, 260 nm; fluorescence detection, excitation wavelength, 310 nm, emission wavelength, 418 nm; capillary temperature, 25°C. For UV detection, the incubation conditions were as follows: CYP3A4: 20 pmol/mL; NADPH: 1 mM; EDTA: 1 mM; concentration of the substrate: 5–10 times its reported literatureKm value; temperature: 37°C; incubation time: 15 min. For fluorescence detection, the concentrations were reduced to CYP3A4: 4 pmol/mL, NADPH: 20 µM, EDTA: 20 µM and substrate: 10 µM. Blank incubations were performed in the absence of substrate. Compared with the blank, significant differences were found for the consumption of NADPH and the production of NADP. The development of this assay system allows rapid assessment of metabolic stability relative to standard compounds, as well as potential identification of the major CYP involved in the metabolism. It would reduce the backlog of compounds that require LC/MS analysis, and thereby expedite the process of metabolic stability screening.
Eigenmobilities in background electrolytes for CZE. V. Intensity (amplitudes) of system peaks
Authors: Hruška Vlastimil , Štědrý Milan , Včeláková Kateřina , Lokajová Jana , Tesařová Eva , Jaroš Michal , Gaš Bohuslav 
Published: November 2006

AbstractWe present a mathematical model of CZE based on the concept of eigenmobilities – the eigenvalues of matrix M tied to the linearized governing equations of electromigration, and the spectral decomposition of matrix M into matrices of amplitudes Pj. Any peak in an electropherogram, regardless of whether it is an analyte peak or a system peak (system zone), is matched with its matrix Pj. This enables calculation of the peak parameters, such as the transfer ratio and the molar conductivity detection response (which give the indirect detection signal and the conductivity detection signal, respectively), when the initial disturbance caused by the injection of the sample is known. We also introduce new quantities, such as the generalized transfer ratio and the conductivity response of system zones, and show how the amplitude (intensity, area) of the analyte peaks and the system peaks can be calculated. We offer a free software, PeakMaster (http://www.natur.cuni.cz/gas), which yields this information in a user‐friendly way.
Volatiles from submerged and surface‐cultured beefsteak fungus, Fistulina hepatica
Authors: Wu Shimin , Zorn Holger , Krings Ulrich , Berger Ralf G. 
Published: November 2006

AbstractCultures of Fistulina hepatica DSMZ 4987 were grown submerged in standard nutrition solution (SNS) or on oak wood powder (OWP). After cell disintegration, the volatile constituents were isolated by continuous liquid–liquid extraction (CLLE) and investigated by high‐resolution gas chromatography coupled to mass spectrometry (HRGC–MS). The surface cultures produced 53 major volatile compounds, while 39 major volatile compounds were found in the submerged cultures. The surface cultures produced several aldehydes, methoxybenzenoids and terpenes, which were absent in the submerged cultures. A strong mushroom aroma was emitted by the surface cultures only. Twenty compounds, mainly long‐chain fatty acids and methyl esters thereof, and short chain aliphatic alcohols, were common to both systems. Copyright © 2006 John Wiley & Sons, Ltd.
Essential oil composition of Agastache anethiodora Britton (Lamiaceae) infected by cucumber mosaic virus (CMV)
Authors: Bruni Renato , Bianchi Alberto , Bellardi Maria Grazia 
Published: November 2006

AbstractGiant hyssop, Agastache anethiodora Britton, cultivated at the Herb Garden of Casola Valsenio, Italy, has been found for the first time naturally infected by cucumber mosaic virus (CMV). Characteristic symptoms on the leaves were chlorotic or yellow mosaic, ring and line patterns and malformation, followed by yellowing and stunting of the entire plant. CMV was mechanically transmitted to species of the families Chenopodiaceae and Solanaceae and identified by applying PAS–ELISA and RT–PCR techniques. The essential oil of both healthy and CMV‐infected plants has been evaluated by means of GC–FID and GC–MS, with the object of identifying composition differences caused by the disease. The infection of A. anethiodora by CMV was found to induce significant reduction in the yield of essential oil and several changes in the relative composition of the main components: pulegone, menthone, iso‐menthone, methyl chavicole and limonene. Methyl chavicole content, in particular, was drastically reduced. The importance of the phytopathological status of essential oil‐bearing plants is outlined. Copyright © 2006 John Wiley & Sons, Ltd.
Thermal degradation of precursors and formation of flavour compounds during heating of cereal products. Part II. The formation and changes of volatile flavour compounds in thermally treated malt extracts at different temperature and pH
Authors: Przybylski R. , Kamiński E. 
Published: November 2006

AbstractThe effect of temperature and pH on the formation and changes of volatile flavour compounds in thermally treated malt extracts was studied. The dependence of thermal treatment parameters on organoleptic properties of the extracts was stated.Alkaline pH of the medium was found to promote the formation of the compounds yielding a caramel odour. The most desirable organoleptic characteristics were obtained at pH 4.0‐5.5 and temperature 140 °C. Thirty compounds typical for nonenzymatic browning were identified.
Akalorische Verbindungen mit fettähnlichen funktionellen Eigenschaften (Pseudofette)
Authors: Mieth G. , Elsner A. , Brückner J. , Weiss A. , Behrens H. 
Published: November 2006

AbstractDie Übersichtsarbeit behandelt Synthese, Charakterisierung, physiko‐chemische und ernährungsphysiologische Eigenschaften akalorischer fettähnlicher Verbindungen (Pseudofette). wobei Saccharose‐Fettsäureester, Glycerolether und Glyceroldicarbonsäureester besondere Berücksichtigung finden. Weiterhin wird ein Ausblick auf andere zur Fettsubstitution potentiell geeignete Verbindungsklassen, wie Polycarbonsäure‐, Polyglycerol‐ und Polyglycolderivate gegeben.
Über die Bestimmung der Estergruppenverteilung im Pektin durch Fraktionierung an DEAE‐Cellulose
Authors: Anger H. , Dongowski G. 
Published: November 2006

AbstractDie Ionenaustauschchromatographie von Pektin an DEAE‐Sephacell erlaubt es, zwischen statistischer und blockweiser Anordnung der freien Carboxylgruppen bei Veresterungsgraden (VG) zwischen 20 und 90% zu unterscheiden. Eine statistische Verteilung freier Carboxylgruppen führt im VG‐Bereich von 15 bis 95% zu einer linearen Abhängigkeit zwischen dem VG und der für die Desorption notwendigen Phosphatkonzentration, die über eine Dichtemessung bestimmt wird. Für diese Präparate läßt sich aus dem Chromatogramm eine VG‐Verteilung unter der Voraussetzung berechnen, daß mit Präparaten ähnlicher Molmasse kalibriert worden ist.
Beeinflussung funktioneller Eigenschaften von Proteinen durch gekoppelte mechanolytische und chemische Modifizierung
Authors: Kroll J. , Gassmann B. , Proll J. , Grütter B. 
Published: November 2006

AbstractSchon bei kurzzeitiger Schwingmahlung reicht der Energieeintrag aus, um Proteine in Gegenwart von Säureanhydriden zu acylieren. Je nach Protein oder Proteinrohstoff sowie der Art und Menge des beigefügten Anhydrids werden 30–60% der £‐Aminogruppen des Lysins blockiert. Als Folge von Mechanolyse und Acylierung verbessern sich für Lebensmittelzwecke in typischer Weise die Löslichkeitsprofile und andere funktionelle Eigenschaften. Am Beispiel von Casein wird gezeigt, daß sich das Ausmaß der bei kurzer Schwingmahldauer mechanolytisch erreichbaren Verschäumbarkeit und Schaumstabilität durch gleichzeitige Acetylierung noch steigern läßt. Eine merkliche Erhöhung des Wasserbindungsvermögens tritt bei Acetylierungsgraden über 40% ein. Die molekularen Vorgänge bei der Kopplung von Mechanolyse und Acylierung von Proteinen und deren Auswirkung auf die funktionellen Eigenschaften werden diskutiert.
Microecology of the gastrointestinal tract and the immunological status under food allergy
Authors: Kuvaeva I. B. , Orlova N. G. , Veselova O. L. , Kuznezova G. G. , Borovik T. E. 
Published: November 2006

AbstractIn children suffering from food allergy the microecology of the gut and the immune status were examined. As a rule, sensitization due to the penetration of the epithelial barrier of the intestinum by macromolecules of the food is not accompanied by deficiency of secretory IgA. In all cases dysbacteriosis of different degree was observed with a characteristic picture of deficiency of Bifidobacteria and Lactobacilli combined with rising numbers of Enterobacteriaceae. Correlations to an altered immune response are obvious.
Adaptation of Pope and Stevens method for rapid determination of the amino nitrogen content in certain raw materials and animal products
Authors: Fik M. , Surówka K. 
Published: November 2006

AbstractThe present study is a continuation of experiments on adaptation of POPE And STEVENS method for rapid determination of proteolytic enzyme activity and protein hydrolysis intensity of food products. The results of the amino nitrogen content of certain meat products are presented by using the earlier described modified method. It was found that when determining amino nitrogen in such raw materials and products as poultry, beef, pork, fresh‐water fish and their hydrolyzates, the traditional and colorimetric methods are equal. Good accuracy, specificity and usefulness were qualities noted for the latter method in repeated and routine experimentation.
Size distribution of casein micelles during milk coagulation
Authors: Omar Mohamed M. 
Published: November 2006

AbstractElectron microscopy was employed to study the size distribution and the surface to volume ratios of casein micelles in coagulum from raw milk, heated milk and milk enriched with calcium chloride before the heating process. The particles size distribution of milk protein was changed by heating resulting in an increase in the free subunits of smaller size and the surface to volume ratios. On the other hand the clotting time was prolonged. Depression in the clotting time and surface to volume ratios was occurred by adding calcium chloride to the milk before the heating process to retard the formation of complex between the whey protein and milk casein.