bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on the dynamic melt rheological properties of polypropylene/wood flour composites
Authors: Azizi H. , Ghasemi I. 
Published: June 2008

AbstractThe rheological behavior of polypropylene/wood flour (WF) composite was investigated at constant temperature over a wide range of frequencies using a mechanical compact rheometer operated in the dynamic mode. The effect of WF content, particle size, and coupling agent on melt rheological properties were investigated. The melt rheological data in terms of complex viscosity (η*), storage modulus (G′), loss modulus (G″), and loss tangent (tan δ) were studied and compared for different samples. It was found that complex viscosity increases with increasing wood content and coupling agent. Compatibilization using coupling agent increased both storage modulus and loss modulus, but the variation of storage modulus is more. By increasing wood content storage modulus increases. Complex viscosity, storage modulus, and loss modulus showed a minimum value by increasing of wood particle size. Tan δ decreases with increasing of wood content. Cole–Cole plot indicated that relaxation process changes with addition WF, coupling agent, and using different mesh size of wood. The Han plots revealed the sensitivity of rheological properties with composition at constant temperature. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Bond performance of FRP rebars with various surface deformations in reinforced concrete
Authors: Esfandeh Masoud , Sabet Ali R. , Rezadoust Amir M. , Alavi Mohammad B. 
Published: June 2008

AbstractOne of the methods used to overcome the corrosion problem associated with steel rebars in reinforced concrete is the application of reinforced polymer (FRP) rebars. Bonding between the rebar and concrete is one of the major factors affecting the mechanical behavior of the structures. In this study, FRP rebars with four different surface configurations and geometries were constructed and their bonding to concrete was examined. These include a pultruded rod with a smooth surface (RO), externally wound FRP rib on the pultruded rod (RT), pultruded rod with sand sprayed on the surface (RS), and a combination of the last two configurations (RTS). Bonding strength of the rebars to concrete was assessed using pull‐out test at the embedment lengths of 12 and 18 cm. Results showed that the increase in surface roughness of the rebars and hence a greater inter‐mechanical locking, plays a major role in their bonding strength to concrete. RO rebar showed the lowest bonding strength to the concrete followed by the RT rebar. Bonding strength to concrete in the latter type was entirely controlled by the adhesion strength of the externally wound FRP rib to the pultruded core. RTS rebars with embedment length of 12 cm showed greater adhesion to the concrete, where as, in samples with embedment length of 18 cm, RTS and RS rebars showed close results. In all the tests conducted, delaminating of the surface texture was the major failure mode. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Mechanical and thermal properties of the hybrid composites of vinylester resin and methacryl‐substituted polysilsesquioxane
Authors: Takahashi Tsutomu , Katoh Takeshi , Sakuma Takenori , Someya Yoshihiro , Shibata Mitsuhiro 
Published: June 2008

AbstractVinylester resin (VER) composed of bisphenol‐A‐based epoxy methacrylate and styrene was cured finally at 120°C with methacryl‐substituted polysilsesquioxane (ME‐PSQ) prepared from 3‐(trimethoxysilyl)propyl methacrylate and tetramethylammonium hydroxide. The dynamic mechanical and thermal properties of the VER/ME‐PSQ 90/10–60/40 hybrid composites were investigated when compared with crosslinked‐VER (C‐VER) and VER/phenyl‐substituted polysilsesquioxane (Ph‐PSQ) 80/20 composite cured at the same condition. As a result, the VER/ME‐PSQ hybrid composites showed much higher storage modulus (E′) at rubbery state than C‐VER and the VER/Ph‐PSQ composite. The E′ of the hybrid composites increased with increasing ME‐PSQ content. Also, coefficient of thermal expansion of the hybrid composites decreased with increasing ME‐PSQ content. The glass transition temperatures and 5% weight loss temperatures of the VER/ME‐PSQ hybrid composites were almost the same as those of C‐VER and the VER/Ph‐PSQ composite. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Theoretical and experimental determination of tensile properties of nanosized and micron‐sized CaCO3/PA66 composites
Authors: Sisakht Mohsen Rastgoo , Saied Nouri Khorasani , Ali Zadhoush , Hosein Enayati Mohammad , Hasan Pezeshki 
Published: June 2008

AbstractThe objective of this research was to investigate the probability of reinforcing Polyamide66 (PA66) with both micron‐sized and nanosized calcium carbonate (CaCO3) particles. For this purpose, micron‐sized and nanosized CaCO3 particles were used as fillers to prepare microcomposites (conventional composites) and nanocomposites via a polymer solution method. The microcomposites and nanocomposites were found to have higher modulus and lower strength than neat PA66. Also, nanocomposites had higher modulus and strength than microcomposites. Theoretical prediction of elastic modulus was carried out using Rule of mixtures, Guth, Nicolais–Narkis, Hashin–Shtrikman, and Halpin–Tsai equations. Calculated results show that these equations cannot predict the results accurately for the work carried out. However, these models can be used with confidence for the prediction of elastic modulus as experimental data are higher than the calculated values. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Optical study of poly(3‐decylthiophene)/CdS nanocomposites
Authors: Dong Yanmao , Lu Jianmei , Yan Feng , Xu Qingfeng 
Published: June 2008

AbstractNanocomposites comprised of poly(3‐alkyl thiophenes) (P3ATs)/semiconductor nanoparticles exhibited excellent photoelectricity performance because of contributions from both the P3ATs and the semiconductor nanoparticles. In this article, poly(3‐decylthiophene) (P3DT) was synthesized and P3DT/CdS nanocomposites were prepared using an in‐situ method. The CdS nanoparticles exhibited strong quantum effect on the photoluminescence (PL) properties of P3DT/CdS and the nanocomposites exhibit an enhanced PL and red‐shifted emission with increasing CdS content. The PL quenched at CdS‐to‐3DT ratio at 0.35 mol%. The charge‐transfer process between P3DT and CdS particles is discussed. P3DT/CdS composites also exhibit excellent nonlinear optical (NLO) properties. The third‐order NLO coefficient of P3DT/CdS (χ(3) = −4.62 × 10−12 esu) is higher than that of P3DT. The P3DT/CdS nanocomposites have potential optical applications. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Thermal properties of PMMA/TiO2 nanocomposites prepared by in‐situ bulk polymerization
Authors: Džunuzović E. , Marinović‐Cincović M. , Vuković J. , Jeremić K. , Nedeljković J.M. 
Published: June 2008

AbstractThe surface of anatase TiO2 nanoparticles, obtained by the controlled hydrolysis of titanium tetrachloride, was modified by 6‐palmitate ascorbic acid. The surface modified TiO2 nanoparticles were dispersed in methyl methacrylate and mixed with a appropriate amount of poly(methyl methacrylate) to obtain a syrup. The nanocomposite sheets were made by bulk polymerization of the syrup in a glass sandwich cell using 2,2′‐azobisisobutyronitrile as initiator. The molar masses and molar mass distributions of synthesized poly(methyl methacrylate) samples were determined by gel permeation chromatography. The content of unreacted double bonds in synthesized samples was determined by 1H NMR spectroscopy. The influence of TiO2 nanoparticles on the thermal stability of the poly(methyl methacrylate) matrix was investigated using thermogravimetric analysis and differential scanning calorimetry. The synthesized samples of poly(methyl methacrylate) have different molar mass and polydispersity depending on the content of the surface modified TiO2 nanoparticles. The values of glass transition temperature of so prepared nanocomposite samples were lower than for pure poly(methyl methacrylate), while the glass transition temperature of samples preheated in inert atmosphere was very similar to the glass transition temperature of pure poly(methyl methacrylate). The thermal stability of nanocomposite samples in nitrogen and air was different from thermal stability of pure poly(methyl methacrylate). POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Blocking and detection chemistries affect antibody performance on reverse phase protein arrays
Authors: Ambroz Kristi L. H. , Zhang Yonghong , Schutz‐Geschwender Amy , Olive D. Michael 
Published: June 2008

AbstractAntibody specificity is critical for RP protein arrays (RPA). The effects of blocking and detection chemistries on antibody specificity were evaluated for Western blots and RPA. Blocking buffers significantly affected nonspecific banding on Western blots, with corresponding effects on arrays. Tyramide signal amplification (TSA) increased both specific and nonspecific signals on Westerns and arrays, masking the expected gradations in signal intensity. These results suggest that consistent blocking and detection conditions should be used for antibody validation and subsequent RPA experiments.
Proteomic analysis of zygote and ookinete stages of the avian malaria parasite Plasmodium gallinaceum delineates the homologous proteomes of the lethal human malaria parasite Plasmodium falciparum
Authors: Patra Kailash P. , Johnson Jeff R. , Cantin Greg T. , Yates John R. , Vinetz Joseph M. 
Published: June 2008

AbstractDelineation of the complement of proteins comprising the zygote and ookinete, the early developmental stages of Plasmodium within the mosquito midgut, is fundamental to understand initial molecular parasite‐vector interactions. The published proteome of Plasmodium falciparum does not include analysis of the zygote/ookinete stages, nor does that of P. berghei include the zygote stage or secreted proteins. P. gallinaceum zygote, ookinete, and ookinete‐secreted/released protein samples were prepared and subjected to Multidimensional protein identification technology (MudPIT). Peptides of P. gallinaceum zygote, ookinete, and ookinete‐secreted proteins were identified by MS/MS, mapped to ORFs (>50 amino acids) in the extent P. gallinaceum whole genome sequence, and then matched to homologous ORFs in P. falciparum. A total of 966 P. falciparum ORFs encoding orthologous proteins were identified; just over 40% of these predicted proteins were found to be hypothetical. A majority of putative proteins with predicted secretory signal peptides or transmembrane domains were hypothetical proteins. This analysis provides a more comprehensive view of the hitherto unknown proteome of the early mosquito midgut stages of P. falciparum. The results underpin more robust study of Plasmodium–mosquito midgut interactions, fundamental to the development of novel strategies of blocking malaria transmission.
Plasmodium lipid rafts contain proteins implicated in vesicular trafficking and signalling as well as members of the PIR superfamily, potentially implicated in host immune system interactions
Authors: Di Girolamo Francesco , Raggi Carla , Birago Cecilia , Pizzi Elisabetta , Lalle Marco , Picci Leonardo , Pace Tomasino , Bachi Angela , de Jong Joke , Janse Chris J. , Waters Andrew P. , Sargiacomo Massimo , Ponzi Marta 
Published: June 2008

AbstractPlasmodium parasites, the causal agents of malaria, dramatically modify the infected erythrocyte by exporting parasite proteins into one or multiple erythrocyte compartments, the cytoplasm and the plasma membrane or beyond. Despite advances in defining signals and specific cellular compartments implicated in protein trafficking in Plasmodium‐infected erythrocytes, the contribution of lipid‐mediated sorting to this cellular process has been poorly investigated. In this study, we examined the proteome of cholesterol‐rich membrane microdomains or lipid rafts, purified from erythrocytes infected by the rodent parasite Plasmodium berghei. Besides structural proteins associated with invasive forms, we detected chaperones, proteins implicated in vesicular trafficking, membrane fusion events and signalling. Interestingly, the raft proteome of mixed P. berghei blood stages included proteins encoded by members of a large family (bir) of putative variant antigens potentially implicated in host immune system interactions and targeted to the surface of the host erythrocytes. The generation of transgenic parasites expressing BIR/GFP fusions confirmed the dynamic association of members of this protein family with membrane microdomains. Our results indicated that lipid rafts in Plasmodium‐infected erythrocytes might constitute a route to sort and fold parasite proteins directed to various host cell compartments including the cell surface.
Altered expression of calreticulin during the development of fibrosis
Authors: Kypreou Katerina P. , Kavvadas Panagiotis , Karamessinis Panagiotis , Peroulis Michalis , Alberti Avra , Sideras Paschalis , Psarras Stelios , Capetanaki Yasemie , Politis Panagiotis K. , Charonis Aristidis S. 
Published: June 2008

AbstractTissue damage following injury leads to inflammation and fibrosis. To understand the molecular mechanisms and the proteins involved in the fibrotic process, we used the well‐established unilateral ureteric obstruction rat model and we analyzed the alterations at early and late time intervals using a classical proteomic approach. Data analysis demonstrates a correlation between calreticulin up‐regulation and progression of fibrosis. Calreticulin is involved in Ca++ homeostasis but has not been previously implicated in animal models of fibrosis. Proteomic analysis consistently revealed up‐regulation of calreticulin in both early and late time intervals. These findings were further confirmed by biochemical and morphological approaches. Next, animal models of lung fibrosis (bleomycin‐induced) and heart fibrosis (desmin‐null) were examined. In the lung model, calreticulin expression was up‐regulated from early time intervals, whereas in the heart model no change in the expression of calreticulin was observed. In addition, TGF‐β, a well known major contributing factor in several fibrotic processes, was found to up‐regulate calreticulin in cultured human proximal tubule epithelial cells. The above observations suggest that calreticulin might be involved in fibrotic processes; however the mechanism(s) underlying its possible involvement are yet unresolved.
Mitochondrial ATP synthase is a target for TNBS‐induced protein carbonylation in XS‐106 dendritic cells
Authors: Je Jeong Hwan , Lee Tae Hyung , Kim Dong Hyun , Cho Young Hun , Lee Ju Hee , Kim Soo Chan , Lee Sang‐Kyou , Lee Jaewon , Lee Min‐Geol 
Published: June 2008

AbstractROS are produced in dendritic cells (DCs) during antigen presentation in contact hypersensitivity (CHS). As a result, ROS cause a number of nonenzymatic protein modifications, including carbonylation, which is the most widely used marker of oxidative stress. 2,4,6‐Trinitrobenzene sulfonic acid (TNBS) is a well‐characterized contact allergen that results in the formation of ROS. However, proteins that are carbonylated in DCs in response to TNBS have not been identified. To study ROS‐dependent protein carbonylation in response to TNBS, we used the well‐established mouse DC line, XS‐106. We focused on the effects of TNBS on oxidation by examining selected oxidative markers. We identified TNBS‐induced ROS and myeloperoxidase (MPO) proteins and demonstrated that the increase in ROS resulted in IL‐12 production. The increase in oxidation was further confirmed by an oxidation‐dependent increase in protein modifications, such as carbonylation. In fact, TNBS strongly induced carbonylation of mitochondrial adenosine triphosphate (ATP) synthase in XS‐106 DCs, as determined by MALDI‐TOF analysis and 2‐D Western blotting. ROS production and protein carbonylation were confirmed in human monocyte‐derived DCs (Mo‐DCs). Furthermore, glutathione (GSH) decreased ROS and protein carbonylation in Mo‐DCs. Carbonylation of ATP synthase in DCs may contribute to the pathophysiology of CHS.
Proteomic analysis of exoproteins expressed by enterotoxigenic Staphylococcus aureus strains
Authors: Pocsfalvi Gabriella , Cacace Giuseppina , Cuccurullo Manuela , Serluca Giovanna , Sorrentino Alida , Schlosser Gitta , Blaiotta Giuseppe , Malorni Antonio 
Published: June 2008

AbstractPathogenic bacteria excrete a variety of virulence factors into extracellular medium and to the cell surface which have essential roles in the colonization and insurrection of the host cells, and thus reflect the degree of bacterial pathogenicity. For the exploration of virulence factors expressed in the secreted proteome fraction, different Staphylococcus aureus strains were analyzed using gel‐based bottom‐up proteomic approach. A total of 119 distinct proteins were identified for the enterotoxin gene cluster (egc) negative and seb gene positive S. aureus American Type Culture Collection (ATCC) 14458 strain by the use of one‐ and 2‐DE based proteomics. Detailed analysis of enterotoxin region of the 2‐D map confirmed, beside the highly expressed staphylococcal enterotoxin B (SEB), the presence of enterotoxin‐like proteins SElK and SElQ previously predicted by genotyping (Sergeev et al.., J. Clin. Microbiol. 2004, 42, 2134–2143). Exoprotein patterns at the late‐exponential (7 h) and stationary (24 h) phases of cellular growth show a high‐level similarity in this region. Comparative analysis of enterotoxin region of five S. aureus strains including two clinical isolates (RIMD 31092 and A900322), a food derived strain (AB‐8802) with highly prevalent egc positive operon and a nonenterotoxigenic reference strain (ROS) revealed the presence of different known enterotoxins and other virulence factors along with a number of core exoproteins. In addition, production of SElL (RIMD 31092) and SElP (A900322) was demonstrated for the first time at the protein level. Under the experimental conditions applied none of the enterotoxins encoded by the genes of egc operon was identified.
Deciphering the proteomic profile of Mycobacterium leprae cell envelope
Authors: Marques Maria Angela M. , Neves‐Ferreira Ana Gisele C. , da Silveira Erika K. Xavier , Valente Richard H. , Chapeaurouge Alexander , Perales Jonas , da Silva Bernardes Renato , Dobos Karen M. , Spencer John S. , Brennan Patrick J. , Pessolani Maria Cristina V. 
Published: June 2008

AbstractThe complete sequence of the Mycobacterium leprae genome, an obligate intracellular pathogen, shows a dramatic reduction of functional genes, with a coding capacity of less than 50%. Despite this massive gene decay, the leprosy bacillus has managed to preserve a minimal gene set, most of it shared with Mycobacterium tuberculosis, allowing its survival in the host with ensuing pathological manifestations. Thus, the identification of proteins that are actually expressed in vivo by M. leprae is of high significance in understanding obligate, intracellular mycobacterial pathogenesis. In this study, a high‐throughput proteomic approach was undertaken resulting in the identification of 218 new M. leprae proteins. Of these, 60 were in the soluble/cytosol fraction, 98 in the membrane and 104 in the cell wall. Although several proteins were identified in more than one subcellular fraction, the majority were unique to one. As expected, a high percentage of these included enzymes responsible for lipid biosynthesis and degradation, biosynthesis of the major components of the mycobacterial cell envelope, proteins involved in transportation across lipid barriers, and lipoproteins and transmembrane proteins with unknown functions. The data presented in this study contribute to our understanding of the in vivo composition and physiology of the mycobacterial cell envelope, a compartment known to play a major role in bacterial pathogenesis.
Identification of protein components from the mature ovary of the sea urchin Evechinus chloroticus (Echinodermata: Echinoidea)
Authors: Sewell Mary A. , Eriksen Soren , Middleditch Martin J. 
Published: June 2008

AbstractThe gonads of sea urchins are a high value seafood product, with considerable research being undertaken worldwide on the development of sea urchin aquaculture. As the best prices are obtained for specific gonad attributes, research has also focused on the development of artificial diets that enhance gonad quality and quantity. Total protein has been used as a measure of gonad quality; yet no studies to date have applied proteomics technology to diet development. Here we use a MudPIT and 2‐DE approach to describe the major proteins in mature ovaries of a New Zealand sea urchin Evechinus chloroticus. This tissue, which is a target seafood product, contained 138 proteins that were identified from the recently completed sea urchin genome (Strongylocentrotus purpuratus) with high confidence. The majority of these proteins had general functions, with only 12 related to ovarian reproductive function. Eighteen proteins were located on the 2‐DE; four of these were directly identified from S. purpuratus protein sequences. In combination this paper shows that the genome resources of S. purpuratus can be used to identify proteins in sea urchins from different families; describes the proteome of E. chloroticus mature ovary; and, provides proteomic tools for analysis of gonads from other edible sea urchins.
Comparative proteomic analysis of PAI‐1 and TNF‐alpha‐derived endothelial microparticles
Authors: Peterson Danielle B. , Sander Tara , Kaul Sushma , Wakim Bassam T. , Halligan Brian , Twigger Simon , Pritchard Kirkwood A. , Oldham Keith T. , Ou Jing‐Song 
Published: June 2008

AbstractEndothelium‐derived microparticles (EMPs) are small vesicles released from endothelial cells in response to cell injury, apoptosis, or activation. Elevated concentrations of EMPs have been associated with many inflammatory and vascular diseases. EMPs also mediate long range signaling and alter downstream cell function. Unfortunately, the molecular and cellular basis of microparticle production and downstream cell function is poorly understood. We hypothesize that EMPs generated by different agonists will produce distinct populations of EMPs with unique protein compositions. To test this hypothesis, different EMP populations were generated from human umbilical vein endothelial cells by stimulation with plasminogen activator inhibitor type 1 (PAI‐1) or tumor necrosis factor‐alpha (TNF‐α) and subjected to proteomic analysis by LC/MS. We identified 432 common proteins in all EMP populations studied. Also identified were 231 proteins unique to control EMPs, 104 proteins unique to PAI‐1 EMPs and 70 proteins unique to TNF‐α EMPs. Interestingly, variations in protein abundance were found among many of the common EMP proteins, suggesting that differences exist between EMPs on a relative scale. Finally, gene ontology (GO) and KEGG pathway analysis revealed many functional similarities and few differences between the EMP populations studied. In summary, our results clearly indicate that EMPs generated by PAI‐1 and TNF‐α produce EMPs with overlapping but distinct protein compositions. These observations provide fundamental insight into the mechanisms regulating the production of these particles and their physiological role in numerous diseases.