bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of O2‐carrying plasma hemoprotein “albumin‐heme” on complement system and platelet activation in vitro and physiological responses to exchange transfusion
Authors: Komatsu Teruyuki , Huang Yubin , Wakamoto Shinobu , Abe Hideki , Fujihara Mitsuhiro , Azuma Hiroshi , Ikeda Hisami , Yamamoto Hisashi , Horinouchi Hirohisa , Kobayashi Koichi , Tsuchida Eishun 
Published: January 2007

AbstractRecombinant human serum albumin (HSA) including the synthetic iron(II)‐porphyrin (FeP), albumin‐heme (HSA‐FeP), is a unique O2‐carrying plasma hemoprotein as a red blood cell substitute. We have investigated the possible influence of HSA‐FeP on the complement system and platelet activation in vitro. The amounts of the serum complement titer CH50 and terminal complement complex SC5b‐9 of human blood serum, incubated with HSA‐FeP (10, 20, and 40 vol %), were almost the same as those of the corresponding samples with HSA. The effect of HSA‐FeP on the platelet reactivity has been demonstrated by conformational changes in the membrane glycoprotein IIb/IIIa and surface expression of an α‐granule membrane protein P‐selectin. Platelet activation in response to the ADP‐stimulation was not influenced by the presence of HSA‐FeP. It can be concluded that the albumin‐heme solution does not facilitate the immunological reaction and platelet activation. Moreover, a 20% exchange transfusion with HSA‐FeP into anesthetized rats has been performed to evaluate the circulation and blood parameters for 6 h. Time course changes in all parameters showed features identical to the control group (without infusion) and HSA group. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Cell growth and detachment from protein‐coated PNIPAAm‐based copolymers
Authors: Moran Martin T. , Carroll William M. , Selezneva Irina , Gorelov Alexander , Rochev Yuri 
Published: January 2007

AbstractThe cultivation of cells requires the use of unfavorable proteolytic enzymes, which cause cell‐surface modification and also need considerable optimization. Recently, with the development of smart polymers, research has looked to using thermoresponsive polymers as cell culture substrates. These novel surfaces allow the cultivation of cells without using enzymes by utilizing the thermoresponsive phase transition property of poly(N‐isopropylacrylamide) (PNIPAAm). Copolymers of PNIPAAm and N‐tert‐butyl‐acrylamide (NtBAm) with varying ratios were synthesized and solvent cast. The copolymer films are coated with cell adhesion promoters such as collagen, poly‐L‐lysine, and laminin to increase their cell adhesion and growth properties. Cell activity measured by the alamarBlue™ and PicoGreen® assays is similar for coated copolymer films and standard tissue culture plastic controls. Deposition of cell adhesion promoters onto the copolymer films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cell detachment from the copolymer films is dependent on copolymer composition and is not affected by the surface coatings of extracellular matrix (ECM) proteins. The results demonstrate a versatile method for the cultivation of cells while eliminating the need for the use of digestive enzymes such as trypsin. © 2007 Wiley Periodicals, Inc. J BiomedMater Res 2007
Plasma‐deposited tetraglyme surfaces greatly reduce total blood protein adsorption, contact activation, platelet adhesion, platelet procoagulant activity, and in vitro thrombus deposition
Authors: Cao Lan , Chang Mark , Lee Chi‐Ying , Castner David G. , Sukavaneshvar Sivaprasad , Ratner Buddy D. , Horbett Thomas A. 
Published: January 2007

AbstractThe ability of tetraethylene glycol dimethyl ether (tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tetraglyme‐coated materials, compared with uncoated and Biospan®‐coated glass slides. In the in vitro disturbed blood flow model, tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme‐coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma‐deposited tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Transmural communication at a subcellular level may play a critical role in the fallout based‐endothelialization of dacron vascular prostheses in canine
Authors: Zhang Ze , Briana Stephen , Douville Yvan , Zhao Hugh , Gilbert Nathalie 
Published: January 2007

AbstractA microporous and permeable wall is important for the healing of vascular prostheses, however, the significance of its permeability to soluble substances at subcellular level has not been demonstrated. Polyester arterial prostheses were prepared in such a way that each of them contained three segments, of which at least one segment was impervious and another segment was permeable to water but impermeable to cells. Twenty graft segments were implanted in 7 dogs as a thoraco–abdominal bypass for 2 months. The prostheses were then harvested, photographed, and treated for histological and morphological studies. The low porosity graft capped by two thrombogenic segments was fully endothelialized, proving the fallout mechanism. The striking contrast with its impermeable counterpart demonstrated that a wall permeable to small substances of subcellular level was critical for the endothelial healing. A wide range of water permeabilities did not reveal advantages of high water permeable segments over low water permeable ones. Endothelial ingrowth from anastomoses was also jeopardized in the absence of wall permeability. In conclusion, transmural communication at a subcellular level may have played a critical role in the fallout based‐endothelialization of arterial prostheses in canine. This highlights the potential function of perigraft cytokines and growth factors in endothelial healing. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Ectopic and in situ bone formation of adipose tissue‐derived stromal cells in biphasic calcium phosphate nanocomposite
Authors: Lin Yunfeng , Wang Tao , Wu Ling , Jing Wei , Chen Xizhe , Li Zhiyong , Liu Lei , Tang Wei , Zheng Xiaohui , Tian Weidong 
Published: January 2007

AbstractAdipose‐derived stromal cells (ASCs) have the potential to differentiate into a variety of cell lineages both in vitro and in vivo. A novel biodegradable biphasic calcium phosphate nanocomposite (NanoBCP) comprising β‐tricalcium phosphate matrix and hydroxyl apatite nanofibers is favorable for bone tissue engineering. In this study, ASCs were harvested from Sprague‐Dawley (SD) rats and induced to osteogenesis before seeded into porous NanoBCP scaffold. To determine ectopic in vivo osteogenic differentiation, these constructs were implanted in nude mice subcutaneously. Meanwhile, the ability of engineered constructs to stimulate in situ bone repair was assessed in rat critical‐size cranial defects. The defects were filled with NanoBCP containing osteogenic ASCs in experimental group; with cell‐free NanoBCP in negative controls; and with nothing in blank controls. The retrieved specimens were analyzed with morphological, histological, and molecular methods. Histological analysis of the retrieved specimens from nude mice in experimental group showed obvious ectopic bone formation. There were positive expression of osteopontin (OPN) and osteocalcin (OCN) at RNA and protein level. As for the cranial defects, there was complete repair in experimental group, but only partial repair in negative controls. The radiographs, H&E staining, and Masson's trichrome method showed better bone regeneration at experimental sites. Combining osteogenic ASCs with NanoBCP can lead to formation of ectopic new bone. Furthermore, the approach can also stimulate bone regeneration and repair for the large size bone defects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Formation of the chondrocranium of Trachemys scripta (Reptilia: Testudines: Emydidae) and a comparison with other described turtle taxa
Authors: Tulenko Frank J. , Sheil Christopher A. 
Published: January 2007

AbstractFew descriptions of the formation of the chelonian chondrocranium exist. Herein, developmental stages critical to the formation of the chondrocranium of the Red‐eared Slider, Trachemys scripta (Testudines: Emydidae), are described and illustrated, with particular attention given to ontogenetic changes that take place in the orbitotemporal region of the skull. Morphological descriptions are based on cleared and double‐stained and serially‐sectioned embryos. These specimens allowed for a detailed evaluation of the developmental morphology of the trabeculae, interorbital septum, pilae metoptica, taeniae marginalis, acrochordal cartilage, pilae antotica, parachordal cartilages, and crista sellaris. Additionally, the formation of the chondrocranium of T. scripta is compared to those of Chrysemys picta (Emydidae) and Caretta caretta (Chelonidae). Overall, the patterns of formation and remodeling of the chondrocranium are quite similar among these species, with the most conspicuous differences observed in remodeling of the posterior orbital cartilages (specifically, the pila metoptica). Reorganization of these cartilages is discussed briefly in the context of associated extraocular muscles for T. scripta and C. caretta. A prominent intertrabecula is reported in T. scripta, supporting previous observations of this structure in emydid turtles. J. Morphol., 2007. © 2007 Wiley‐Liss, Inc.
Ultrastructure and tubulin immunocytochemistry of the copulatory stylet‐like structure in Childia species (Acoela)
Authors: Tekle Yonas I. , Raikova Olga I. , Justine Jean‐Lou , Jondelius Ulf 
Published: January 2007

AbstractOne of the main characters used in acoel taxonomy is the male copulatory organ. Despite this, ultrastructural studies of this structure are scarce. We studied the ultrastructure of the copulatory organ in eight species of acoels belonging to the taxon Childia. Members of Childia possess a well‐developed conical or cylindrical stylet‐like structure composed of needles. Immunogold cytochemistry of tubulin was used to determine the composition of the needles. Stylet‐like structures of Childia species at the ultrastructural level are basically similar. Stylet needles show intracellular differentiations. As shown both by ultrastructural and immunocytochemical methods, the stylet needles, in all species studied, are composed of long, parallel microtubules, either tightly packed or polymerized. We report unusual polymerization of microtubules, resulting in formation of a honeycomb‐like structure in cross section. Variations of ultrastructure among Childia species include numbers and arrangement of stylet needles, shape of needles, needle compactness, microtubule polymerization, direction of stylet growth, and presence/absence of different types of granules. The stylet‐like structures are homologous within Childia, but are likely to prove nonhomologous with the other needle‐like structures found in acoel copulatory organs. Stylets in Platyhelminthes are not homologous with stylet‐like structures in acoels. J. Morphol., 2007. © 2007 Wiley‐Liss, Inc.
An assessment of ‘international best practice’ in visitor attraction management: does Scotland really lag behind?
Authors: Garrod Brian , Leask Anna , Fyall Alan 
Published: January 2007

AbstractThis paper compares and contrasts selected management practices among visitor attractions in Scotland, Australia, Canada and New Zealand. The catalyst for the study was the growing perception that management practices among visitor attractions in Scotland are becoming increasingly outdated and that the sector needs to learn from ‘international best practice’ in this respect. A postal questionnaire was sent to all paid‐admission visitor attractions in the four countries. In total, 1022 visitor attractions replied, representing an overall response rate of 41%. Chi‐square analysis was then used to test various hypotheses relating to the uptake of these management practices. A key conclusion is that although management practices do vary significantly among the four countries, Scotland does not necessarily lag behind. Indeed, Scottish visitor attractions seem to lead the way in many respects. Meanwhile, the study finds no strong evidence to suggest that visitor attractions in the other three countries have indeed identified and are following a common ‘international best practice’. Copyright © 2007 John Wiley & Sons, Ltd.
Investigation of wear mechanism by organic sulphides in vegetable oils
Authors: Minami Ichiro , Kubo Tomoo , Shimamoto Daisuke , Takahashi Daisuke , Nanao Hidetaka , Mori Sigeyuki 
Published: January 2007

AbstractTribological properties of organic sulphides in esters were examined under boundary conditions. Magnification of wear by sulphides was observed in unsaturated esters. A dumb‐bell‐shaped wear scar, composed of a ‘central area’ and a ‘border area’, was found as an intermediate of wear growth. The ‘border area’ then expanded, resulting in a large wear scar. An induction period was observed before the generation of the ‘border area’. Influences of additive concentration on the induction period were also observed. Surface analyses of worn surfaces revealed that organic oxides, sulphides (unreacted additive) and sulphoxides are present in the boundary film. Influence of auto‐oxidation of the base oil on wear mechanism was proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling the Cure of an Epoxy‐Amine Resin with Bisphenol A as an External Catalyst
Authors: Perrin François‐Xavier , Nguyen Thi Minh Hanh , Vernet Jean‐Louis 
Published: January 2007

AbstractThe cure kinetics of a DGEBF/DGEBA mixture with a commercial aliphatic amine mixture [poly(propylene) oxide diamine D230 and diethylene triamine (DETA)] was investigated by DSC. Two types of kinetic models based upon the formation of amine‐epoxy‐hydroxyl transition complex without or with fast pre‐equilibria have been tested and discussed. The mechanistic model with pre‐equilibria was based on the existence of two different epoxy‐hydroxyl complexes namely one involving hydroxyl groups of BPA and the other, the hydroxyl groups of polymer chains. All the kinetic and thermodynamic parameters have been evaluated and discussed. The results show that the mechanistic model with pre‐equilibria determined from isothermal cure provide a more reasonable fitting of the polymerization kinetics under programmed heating‐rate modes than Horie's model. Moreover, the former kinetic model allows the prediction of changes in the BPA content of the initial formulation with good accuracy.magnified image
Mechanistic Investigations on a Diynone Type Photoinitiator
Authors: Seidl Bernhard , Liska Robert 
Published: January 2007

AbstractRecently, it has been shown that 1,5‐diphenyl‐penta‐1,4‐diyn‐3‐one (DPD) has some surprising characteristics as photoinitiator for free radical polymerization. In the present investigations we focused on the photochemistry in hydrogen donating isopropyl alcohol (IPA) and neutral acetonitrile (MeCN). HPLC and column chromatographic separation were applied for photoproduct identification. Different types of radical quenchers such as the stable radical TEMPO and the non‐polymerizable monomer methyl t‐butacrylate (t‐BAM) were also used to identify the initiating species. In IPA, fast hydrogen abstraction reaction similar to that of benzophenone was found, whereas the hydrogen donor is the initiating molecule. Significantly, slower 2 + 2 cycloaddition reaction involving the carbonyl group is the predominant pathway in MeCN. Experiments with t‐BAM indicated that DPD is directly responsible for the initiation process.magnified image
Lower Critical Solution Temperature Properties of N‐Isopropylacrylamide‐Based Pseudopolyrotaxanes by Complexation with Cucurbituril[6]
Authors: Choi Soo Whan , Ritter Helmut 
Published: January 2007

AbstractPseudopolyrotaxanes 4a and 5a are synthesized by two paths: a) directly from the pseudorotaxane, and b) by complexing with cucurbituril (CB[6]) in water at room temperature after the polymerization. Free radical copolymerization with CB[6] (un)complexed monomer and N‐isopropylacrylamide (NIPAAM) is carried out using a redox initiator in aqueous media at room temperature. The properties of pesudorotaxanes (4a and 5a) and polymers (4 and 5) are investigated by TGA, DSC, and turbidity measurements. The lower critical solution temperatures of the NIPAAM‐containing copolymers and CB[6] are significantly higher than those of pure NIPAAM copolymers. The pseudopolyrotaxanes 4a and 5a have a higher thermal stability, as a result of threading of the CB[6] rings onto the polymer side groups.magnified image
Formation of martensite in 304 grade stainless steels and their welds
Authors: Michler T. 
Published: January 2007

AbstractThe formation of martensite in metastable austenitic stainless steels was investigated. The results showed that the formation of martensite in 304 grade stainless steels due to the exposure to cryogenic temperatures is negligible. The amount of formed martensite is dependent on the chemical composition of the actual heat but for standard grades the amount is not expected to exceed a very few percent. In welds the formation of martensite is not promoted by the presence of δ‐ferrite. The formation of martensite due to cold forming at room temperature can reach around 20 %. Cold forming with subsequent exposure to cryogenic temperatures does not lead to additional formation of martensite due to the exposure to low temperatures. Cold forming at low temperatures leads to the highest amount of martensite formed in metastable stainless steels.
Low Heat Welding of Titanium Materials with a Pulsed Nd:YAG Laser
Authors: Richter K. , Behr W. , Reisgen U. 
Published: January 2007

AbstractTitanium materials exhibit a property profile that is just as versatile as that of steel materials. Titanium materials therefore have outstanding properties, such as excellent resistance to corrosion and high strength values at low densities, which makes them ideal for use in the chemical industry and as structural materials in lightweight construction.Due to the high affinity of titanium to atmospheric gases at increased temperatures above 500 °C, titanium components have to be welded in a sophisticated process under inert shielding gas by TIG welding or by an electron beam in a vacuum.A novel innovative laser beam welding process using a pulsed laser with free pulse shaping will be presented here with which oxidation‐free titanium weld seams with excellent mechanical and technological properties can be produced. For this low heat welding process, the otherwise commonly used inert gas covering can be substituted with a shielding gas nozzle. The process‐specific low heat input and the resulting low energy input per unit length both have a positive effect on the microstructure and thus on the mechanical properties.This welding process offers both technological and economical advantages over the processes used up until now, particularly for the machining of complex components and for series production.
Impact of copper on the induction and repair of oxidative DNA damage, poly(ADP‐ribosyl)ation and PARP‐1 activity
Authors: Schwerdtle Tanja , Hamann Ingrit , Jahnke Gunnar , Walter Ingo , Richter Constanze , Parsons Jason L. , Dianov Grigory L. , Hartwig Andrea 
Published: January 2007

AbstractCopper is an essential trace element involved, among other functions, in enzymatic antioxidative defense systems. However, nonprotein bound copper ions have been shown to generate reactive oxygen species. To gain insight into the discrepancy between the protective properties of copper on the one hand and its toxicity on the other hand, we examined the genotoxic effects of CuSO4in cultured human cells. Here we report that copper, at cytotoxic concentrations, induces oxidative DNA base modifications and DNA strand breaks. However, at lower noncytotoxic concentrations, copper inhibits the repair of oxidative DNA damage induced by visible light. As a first mechanistic hint, inhibition of H2O2‐induced poly(ADP‐ribosyl)ation was identified in cultured cells and further experiments demonstrated a strong inhibition of the activity of isolated poly(ADP‐ribose)polymerase‐1 (PARP‐1) by copper. Bioavailability studies of copper showed a dose‐dependent uptake in cells and pointed out the relevance of the applied concentrations. Taken together, the results indicate that copper, under conditions of either disturbed homeostasis or overload due to high exposure, exerts defined genotoxic effects. Hence, a balance needs to be maintained to ensure sufficient uptake and to prevent overload.
Fecal water from ileostomic patients consuming oat β‐glucan enhances immune responses in enterocytes
Authors: Ramakers Julian D. , Volman Julia J. , Biörklund Maria , Önning Gunilla , Mensink Ronald P. , Plat Jogchum 
Published: January 2007

AbstractYeast, fungal, and dietary β‐glucans have immune‐modulating effects in vitro and in vivo, as thought, mainly by affecting leukocytes; however, effects of oat β‐glucan on enterocytes have never been studied. As recognized, supplying oat β‐glucans as such to cells in culture directly is difficult because of solubility problems. Therefore, six ileostomic patients consumed, in random order, a control diet or an oat β‐glucan enriched diet (5 g) and from the collected ileostomic content, fecal water was prepared and added to two small intestinal cell lines (INT407, Caco‐2) and two colon cell lines (HT29, T84) together with a cytokine cocktail (IL‐1β + INFγ + TNFα). Several parameters reflecting immune‐modulation were measured. As compared to placebo fecal water, β‐glucan enriched fecal water significantly increased IL‐8 production in HT29 (5.0%; p = 0.046) and INT407 cells (22.0%; p = 0.028). Intercellular adhesion molecule (ICAM)‐1 expression increased in T84 (11.0%; p = 0.028) and Caco‐2 cells (20.4%; p = 0.075). These immune‐stimulating effects were confirmed by enhancement of inflammatory expression profiles, as determined with an antibody array. Our findings show immune enhancement by fecal water from ileostomic patients consuming oat β‐glucan both in small intestinal and colon cell lines after stimulation, which is in agreement with documented effects in leukocytes. Whether these immune‐stimulating effects on enterocytes contribute to the enhanced protection of the host against invading pathogens as observed both in animals and in humans, as well as the underlying mechanism, needs further evaluation.