bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extrusion of feather keratin
Authors: Barone Justin R. , Schmidt Walter F. , Gregoire N. T. 
Published: January 2006

AbstractKeratin obtained from poultry feathers was extruded at 120°C using a combination of glycerol, water, and sodium sulfite as processing aids. Rheological properties were assessed as a function of water, glycerol, and sodium sulfite content as well as extruder die temperature. The lowest viscosity blends at a constant feather keratin concentration of 60 wt % were found at glycerol concentrations that were higher than the water concentration and sodium sulfite concentrations of 3–4 wt % of the feather keratin fraction. For the melt state, higher or lower sodium sulfite concentrations resulted in increased viscosity. In the solid state, it was observed that processing induced orientation increased the tensile properties of the extrudates. Raman spectroscopy and DSC showed that there was a transition from α‐helix to β‐sheet at sodium sulfite concentrations of less than 4 wt %. At greater sodium sulfite concentration, increased crystallinity was found, because keratin chains could be extended more during processing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1432–1442, 2006
Synthetic preparations and physical and electrical properties of main chain type thermotropic liquid crystalline polyimide/SiO2 nanocomposites
Authors: Ho Czung‐Yu , Lee Jiunn‐Yih 
Published: January 2006

AbstractTwo kinds of monomers, 1,3‐bis[4‐(4′‐amino‐Phenoxy)cumyl]benzene (BACB) and pyromellitic dianhydride were used to synthesize the Liquid Crystalline Polyamic acid—a precursor (LCPAA) of Liquid Crystalline Polyimide (LCPi). The nanohybrid films were successfully prepared by the sol–gel reaction. Tetraethoxysilane (TEOS) (99%)–ethanol (99.8%) solution was added to LCPAA solution. The hybrid films were made by the hydrolysis–polycondensation of TEOS–ethanol in the LCPAA solution. When water and the solvent were removed completely, the hybrid films were obtained. The functional group and chemical structure were characterized by FTIR. We employed a number of instruments to understand whether the nano‐SiO2 particle was introduced into the polymer matrix and enhanced the thermal properties and mechanical strength. The liquid crystalline phase of the LCPi and LCPi/SiO2 hybrid films was observed by POM. TGA and DSC were used to test the thermal properties. The crystallization and liquid crystal phase analyses were carried out by XRD. The elemental analysis was employed to measure the 1,3‐bis[4‐(4′‐nitrophenoxy)cumyl)]benzene and BACB monomers. Besides, the cross section at morphology of the materials was observed with an FESEM. The electrical properties of hybrid films were measured by the high resistance analysis and dielectric constant analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1688–1704, 2006
Characteristics of konjac glucomannan and poly(acrylic acid) blend films for controlled drug release
Authors: Yu Huiqun , Huang Aibin , Xiao Chaobo 
Published: January 2006

AbstractNovel polymer blend films composed of konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by mixing the aqueous solution of both samples at a different weight ratio. Their structure and properties were studied by attenuated total reflection infrared spectroscopy (ATR‐IR), wide angle X‐ray diffraction (WAXD), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), tensile strength test, and equilibrium swelling test. The structure analysis indicated that there is a strong interaction between KGM and PAA, which result in a uniform structure and complete miscibility between the components. Potential applications of the polymer composed matrices in controlled drug delivery were also examined. The drug‐loaded KGM/PAA composed matrices were prepared by coated films and directly compressed tablets, respectively. The release mechanism of a model drug, ketoprofen, from two matrices in phosphate buffer solution (pH = 7.4) was studied. Release behavior of ketoprofen rely on preparation methods of matrices and the ratio of KGM to PAA in matrices. The result showed that the drug release from the coated films is Fickian diffusion mechanism. However, for tablets, the drug release is a non‐Fickian kinetics process. Various delivery parameters have been calculated and the results are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1561–1570, 2006
Cure kinetics of aqueous phenol–formaldehyde resins used for oriented strandboard manufacturing: Analytical technique
Authors: Lei Y. , Wu Q. , Lian K. 
Published: January 2006

AbstractThe cure kinetics of commercial phenol–formaldehyde (PF), used as oriented strandboard face and core resins, were studied using isothermal and dynamic differential scanning calorimetry (DSC). The cure of the face resin completely followed an nth‐order reaction mechanism. The reaction order was nearly 1 with activation energy of 79.29 kJ mol−1. The core resin showed a more complicated cure mechanism, including both nth‐order and autocatalytic reactions. The nth‐order part, with reaction order of 2.38, began at lower temperatures, but the reaction rate of the autocatalytic part increased much faster with increase in curing temperature. The total reaction order for the autocatalytic part was about 5. Cure kinetic models, for both face and core resins, were developed. It is shown that the models fitted experimental data well, and that the isothermal DSC was much more reliable than the dynamic DSC in studying the cure kinetics. Furthermore, the relationships among cure reaction conversion (curing degree), cure temperature, and cure time were predicted for both resin systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1642–1650, 2006
Clinical study of hereditary disorders of connective tissues in a Chilean population
Authors: Bravo Jaime F. , Wolff Carlos 
Published: January 2006

AbstractObjectiveTo demonstrate the high frequency and lack of diagnosis of joint hypermobility syndrome (JHS) and the seriousness of vascular Ehlers‐Danlos syndrome (VEDS).MethodsTwo hundred forty‐nine Chilean patients with hereditary disorders of the connective tissues (CTDs) and 64 control subjects were evaluated for the diagnoses of JHS and VEDS using the validated Brighton criteria, as compared with the traditional Beighton score. In addition, the presence of blue sclera was determined, with the degree of intensity graded as mild, moderate, or marked.ResultsThe frequency of hereditary CTDs was 35%, with diagnoses of JHS in 92.4% of subjects, VEDS in 7.2%, and osteogenesis imperfecta in 0.4%. The Beighton score proved to be insufficient for the diagnosis of JHS (35% of subjects had a negative score), whereas the Brighton criteria yielded positive findings (a diagnosis of JHS) in 39% of control subjects. Blue sclera was frequent, being identified in 97% of JHS patients and 94% of VEDS patients. Moderate osteopenia/osteoporosis was observed in 50% of patients with VEDS and 26% of those with JHS. Dysautonomia, dyslipidemia, and scoliosis were more frequent in VEDS patients than in JHS patients. The typical JHS facial appearance and the “hand holding the head sign” were identified. Raynaud's phenomenon was extremely rare in JHS patients (2%). Ruptured uterus and cerebral aneurysm occurred in 12% and 6% of VEDS patients, respectively. Spontaneous pneumothorax was more frequent in VEDS patients (11%) than in JHS patients (0.9%).ConclusionJHS is very frequent but usually undiagnosed. The Beighton score is an insufficient method for JHS diagnosis. We recommend that physicians learn to recognize the typical facial features of JHS and be able to identify blue sclera. We also propose that validated hypermobility criteria be routinely used. Further research is needed to determine why the prevalence of JHS is so high in Chile.
Apoptosis of rheumatoid synovial cells by statins through the blocking of protein geranylgeranylation: A potential therapeutic approach to rheumatoid arthritis
Authors: Nagashima Takao , Okazaki Hitoaki , Yudoh Kazuo , Matsuno Hiroaki , Minota Seiji 
Published: January 2006

AbstractObjectiveTo determine whether statins induce apoptosis in rheumatoid arthritis (RA) synoviocytes.MethodsThe effects of lipophilic and hydrophilic statins (fluvastatin and pravastatin, respectively) on the apoptosis of cultured RA synoviocytes were examined in vitro. Apoptosis was analyzed by flow cytometry after staining with JC‐1 (to measure the mitochondrial transmembrane potential), active caspase 3, annexin V, and propidium iodide. Add‐back experiments were conducted to determine which downstream products of the mevalonate pathway could suppress apoptosis. Modulation of various signaling pathways induced by statins, including protein prenylation, was also investigated.ResultsFluvastatin, but not pravastatin, induced apoptosis in RA synoviocytes in a concentration‐dependent (1–10 μM) and time‐dependent (48–96 hours) manner. Another lipophilic statin, pitavastatin, displayed almost the same effects as fluvastatin. In sharp contrast, lipophilic statins did not significantly increase apoptosis in synoviocytes from patients with osteoarthropathy. Apoptosis induced by fluvastatin was mitochondrial‐ and caspase 3–dependent and was abrogated by mevalonate and geranylgeranyl pyrophosphate, but not by farnesyl pyrophosphate. In addition, the geranylgeranyl transferase inhibitor GGTI‐298 mimicked the effect of fluvastatin on RA synoviocytes. Treatment of RA synoviocytes with the RhoA kinase inhibitor Y‐27632 caused apoptosis. Fluvastatin decreased the amount of RhoA protein in the membrane fraction, but increased the amount in the cytosolic fraction.ConclusionFluvastatin induced apoptosis in RA synoviocytes through a mitochondrial‐ and caspase 3–dependent pathway and by the blockage of mevalonate pathways, particularly through the inhibition of protein geranylgeranylation and RhoA/RhoA kinase pathways. These findings suggest that lipophilic statins have potential as novel therapeutic agents for RA.
Treatment of early seropositive rheumatoid arthritis: Doxycycline plus methotrexate versus methotrexate alone
Authors: O'Dell James R. , Elliott Jennifer R. , Mallek Jack A. , Mikuls Ted R. , Weaver Cynthia A. , Glickstein Scott , Blakely Kent M. , Hausch Raymond , Leff Rob D. 
Published: January 2006

AbstractObjectiveTo compare the efficacy of doxycycline plus methotrexate (MTX) versus MTX alone in the treatment of early seropositive rheumatoid arthritis (RA), and to attempt to differentiate the antibacterial and antimetalloproteinase effects of doxycycline.MethodsSixty‐six patients with seropositive RA of <1 year's duration who had not been previously treated with disease‐modifying antirheumatic drugs were randomized to receive 100 mg of doxycycline twice daily with MTX (high‐dose doxycycline group), 20 mg of doxycycline twice daily with MTX (low‐dose doxycycline group), or placebo with MTX (placebo group), in a 2‐year double‐blind study. Treatment was started with an MTX dosage of 7.5 mg/week, which was titrated every 3 months until remission was reached (maximum dosage of 17.5 mg/week). The primary end point was an American College of Rheumatology 50% improvement (ACR50) response at 2 years.ResultsACR50 responses were observed in 41.6% of patients in the high‐dose doxycycline group, 38.9% of those in the low‐dose doxycycline group, and 12.5% of patients in the placebo group. Results of chi‐square analysis of the ACR50 response in the high‐dose doxycycline group versus that in the placebo group were significantly different (P = 0.02). Trend analysis revealed that the ACR20 response and the ACR50 response were significantly different between groups (P = 0.04 and P = 0.03, respectively). MTX doses at 2 years were not different among groups. Four patients in the high‐dose doxycycline group, 2 patients in the low‐dose doxycycline group, and 2 patients in the placebo group were withdrawn because of toxic reactions.ConclusionIn patients with early seropositive RA, initial therapy with MTX plus doxycycline was superior (based on an ACR50 response) to treatment with MTX alone. The therapeutic responses to low‐dose and high‐dose doxycycline were similar, suggesting that the antimetalloproteinase effects were more important than the antibacterial effects. Further studies to evaluate the mechanism of action of tetracyclines in RA are indicated.
The accumulation of intracellular ITEGE and DIPEN neoepitopes in bovine articular chondrocytes is mediated by CD44 internalization of hyaluronan
Authors: Embry Flory Jennifer J. , Fosang Amanda J. , Knudson Warren 
Published: January 2006

AbstractObjectiveA dramatic loss of aggrecan proteoglycan from cartilage is associated with osteoarthritis. The fate of residual G1 domains of aggrecan is unknown, but inefficient turnover of these domains may impede subsequent repair and retention of newly synthesized aggrecan. Thus, the objective of this study was to determine whether ITEGE‐ and DIPEN‐containing G1 domains, generated in situ, are internalized by articular chondrocytes, and whether these events are dependent on hyaluronan (HA) and its receptor, CD44.MethodsITEGE and DIPEN neoepitopes were detected by immunofluorescence staining of bovine articular cartilage chondrocytes treated with or without interleukin‐1α (IL‐1α). Additionally, purified ITEGE‐ or DIPEN‐containing G1 domains were aggregated with HA and then added to articular chondrocytes, articular chondrocytes transfected with CD44▵67, or COS‐7 cells transfected with or without full‐length CD44. Internalized epitopes were distinguished by their resistance to extensive trypsinization of the cell surface.ResultsBoth ITEGE and DIPEN were visualized within the extracellular cell‐associated matrix of chondrocytes as well as within intracellular vesicles. Following trypsinization, the intracellular accumulation of both epitopes was clearly visible. IL‐1 treatment increased extracellular as well as intracellular ITEGE epitope accumulation. Once internalized, the ITEGE neoepitope became localized within the nucleus and displayed little colocalization with HA, DIPEN, or other G1 domain epitopes. The internalization of both ITEGE and DIPEN G1 domains was dependent on the presence of HA and CD44.ConclusionOne important mechanism for the elimination of residual G1 domains following extracellular degradation of aggrecan is CD44‐mediated co‐internalization with HA.
Induction of triggering receptor expressed on myeloid cells 1 in murine resident peritoneal macrophages by monosodium urate monohydrate crystals
Authors: Murakami Yousuke , Akahoshi Tohru , Hayashi Izumi , Endo Hirahito , Kawai Shinichi , Inoue Matsuhisa , Kondo Hirobumi , Kitasato Hidero 
Published: January 2006

AbstractObjectiveTriggering receptor expressed on myeloid cells 1 (TREM‐1) is a cell surface molecule that was recently identified on monocytes and neutrophils. TREM‐1 has been implicated in the early inflammatory responses induced by microbes, but its pathophysiologic role in nonmicrobial inflammation remains unknown. In the present study, we investigated the role of TREM‐1 in acute inflammation induced by monosodium urate monohydrate (MSU) crystals. Induction of TREM‐1 expression by MSU crystal–stimulated murine resident peritoneal macrophages and infiltrating leukocytes in a murine air‐pouch model of crystal‐induced acute inflammation was determined. The biologic role of TREM‐1 in crystal‐induced cytokine production by resident peritoneal macrophages was also investigated.MethodsTREM‐1 expression by resident peritoneal macrophages and infiltrating leukocytes in a murine air‐pouch model was determined by quantitative real‐time polymerase chain reaction, Western blot analysis, and flow cytometry. Cytokine production by resident peritoneal macrophages after incubation with MSU crystals in the presence or absence of an anti–TREM‐1 agonist antibody was determined by enzyme‐linked immunosorbent assay.ResultsTREM‐1 expression by resident peritoneal macrophages was significantly induced after stimulation with the crystals. Maximum expression of TREM‐1 transcripts and protein occurred at 1 and 4 hours after exposure to the crystals, respectively. Costimulation of resident peritoneal macrophages with MSU crystals and an anti–TREM‐1 agonist antibody synergistically increased the production of both interleukin‐1β and monocyte chemotactic protein 1 compared with stimulation with the crystals alone. MSU crystals also induced TREM‐1 expression in infiltrating leukocytes in a murine air‐pouch model of crystal‐induced acute inflammation.ConclusionThese findings suggest that rapid induction of TREM‐1 expression on resident peritoneal macrophages and neutrophils by MSU crystals may contribute to the development of acute gout through enhancement of inflammatory responses.
Can scientific journals be classified in terms of aggregated journal‐journal citation relations using the Journal Citation Reports?
Authors: Leydesdorff Loet 
Published: January 2006

AbstractThe aggregated citation relations among journals included in the Science Citation Index provide us with a huge matrix, which can be analyzed in various ways. By using principal component analysis or factor analysis, the factor scores can be employed as indicators of the position of the cited journals in the citing dimensions of the database. Unrotated factor scores are exact, and the extraction of principal components can be made stepwise because the principal components are independent. Rotation may be needed for the designation, but in the rotated solution a model is assumed. This assumption can be legitimated on pragmatic or theoretical grounds. Because the resulting outcomes remain sensitive to the assumptions in the model, an unambiguous classification is no longer possible in this case. However, the factor‐analytic solutions allow us to test classifications against the structures contained in the database; in this article the process will be demonstrated for the delineation of a set of biochemistry journals.
Propionate inhibits glucose‐induced insulin secretion in isolated rat pancreatic islets
Authors: Ximenes Helena M. A. , Hirata Aparecida E. , Rocha Marlene S. , Curi Rui , Carpinelli Angelo R. 
Published: January 2006

AbstractDietary fibers, probably by generating short chain fatty acids (SCFA) through enterobacterial fermentation, have a beneficial effect on the control of glycemia in patients with peripheral insulin resistance. We studied the effect of propionate on glucose‐induced insulin secretion in isolated rat pancreatic islets. Evidence is presented that propionate, one of the major SCFA produced in the gut, inhibits insulin secretion induced by high glucose concentrations (11.1 and 16.7 mM) in incubated and perfused pancreatic islets. This short chain fatty acid reduces [U‐14C]‐glucose decarboxylation and raises the conversion of glucose to lactate. Propionate causes a significant decrease of both [1‐14C]‐ (84%) and [2‐14C]‐pyruvate (49%) decarboxylation. These findings indicate pyruvate dehydrogenase as the major site for the propionate effect. These observations led us to postulate that the reduction in glucose oxidation and the consequent decrease in the ATP/ADP ratio may be the major mechanism for the lower insulin secretion to glucose stimulus induced by propionate. Copyright © 2006 John Wiley & Sons, Ltd.
Adsorption Isotherms of Citric Acid Acting as a Growth‐Suppressor onto the (100) and (111) Faces of Sodium Chloride Crystals in Supersaturated Aqueous Solution
Authors: Sasaki S. , Kubota N. , Doki N. 
Published: January 2006

AbstractThe growth‐starting supercooling ΔTG, a degree of supercooling at which a crystal starts to grow when the solution is continuously cooled, was measured in supersaturated aqueous solutions in the presence of citric acid as an impurity. It was measured both for the (100) and (111) faces of sodium chloride crystals. From the measured data of ΔTG, the Langmuir constants of the (100) and (111) faces were determined at pH = 4.5 to be 6.16 ± 0.88 L/mol and 12.5 ± 2.0 L/mol, respectively. This ΔTG method is a convenient method for the determination of adsorption isotherms of an impurity onto specific crystallographic faces of a crystal.
Strategy to Obtain nm Size Crystals through Precipitation in the Presence of Polyelectrolyte
Authors: Hirasawa I. , Mikami T. , Katayama A. , Sakuma T. 
Published: January 2006

AbstractCrystals of lead sulfate were precipitated in solutions of various polyelectrolyte polymers (acidic, neutral, and basic polymers) using a double‐jet crystallizer. Polyetyleneimine (PEI) basic polymer controlled both the nucleation rate and crystal growth rate, and enabled the production of fine monodispersed crystals. The on‐line measurement of the variation in the lead concentration indicated that PEI lost its effect when a certain amount of the reactants Ntot was supplied. Interaction between lead ions and PEI was detected by NMR analysis, which suggested that lead ions made some kind of complex with PEI. The values of Ntot correlated well with the weight of PEI in the solution, regardless of the feed flow rate and reactant concentration, as shown in the correlative equation Ntot = k W0.49. It was suggested that PEI could no longer control the precipitation rate when the amount of reactants supplied exceeded Ntot. Thereafter, rapid nucleation occurred. Precipitation with PEI could be controlled by a certain amount of PEI in a ground solution in order to produce monodispersed fine crystals. These results give an effective idea of how to create various nm size crystals.
Partial Miscibility of Organic Compounds in the Solid State – The Case of Two Epimers of a Diastereoisomer
Authors: Beckmann W. , Lorenz H. 
Published: January 2006

AbstractThe purification that can be attained via crystallization is on the one hand governed by kinetic factors, such as the growth rate, and can on the other hand be limited by thermodynamic factors, such as the formation of a solid solution of the impurity with the product. For organic substances, these solid solubilities are difficult to establish, especially for low partial solubilities in the solid state. For the case of the crystallization of two epimers of a diastereoisomer, the formation of partial solid solutions with a respective solubility limited to approximately 5 % and 3 % has been shown using both DSC and XRPD measurements. The enthalpies of fusion of the solids are a strong function of the content of the opposite epimer. This can be interpreted with a disruption of bonds in the lattice, a disruption index of ∼ 8 is found. First determinations of the crystal structure of one of the epimers suggest the formation of a solid solution, which occurs via the replacement of dimers of molecules that are bound by two hydrogen bonds involving the epimeric hydroxyl group and a vicinal phenoxy group. By replacing dimers, the lattice distortion might be limited.
Seeding during Batch Cooling Crystallization – An Initial Approach to Heuristic Rules
Authors: Warstat A. , Ulrich J. 
Published: January 2006

AbstractAn experimental study on batch cooling crystallization is presented here using four different materials, different seeding techniques, and different cooling profiles. The experimental results are analyzed with the aim of extracting some general rules for the dependence of seeding procedures on material properties. These rules are presented in the form of heuristic rules with the specific aim of providing guidelines on how to improve product quality (purity and size distribution) by using a seeding technique.