bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rho proteins are negative regulators of TLR2, TLR3, and TLR4 signaling in astrocytes
Authors: Borysiewicz Elizabeth , Fil Daniel , Konat Gregory W. 
Published: December 2008

AbstractThe family of Toll‐like receptors (TLRs) expressed by innate immune cells recognizes a spectrum of microbial components as well as molecules released from injured tissues. TLR ligation activates intracellular signaling cascades that culminate in the up‐regulation of proinflammatory genes. We have recently demonstrated that the up‐regulation of inflammatory cytokines mediated by TLR4 in astrocytes is negatively controlled by the monomeric GTPases of Rho subfamily. The present study was undertaken to examine further the involvement of Rho proteins in the inflammatory response of astrocytes elicited by the ligation of three TLRs that use divergent signaling pathways. Astrocyte cultures established from newborn rat brains were challenged with ligands of TLR2, TLR3, and TLR4. The expression of genes encoding interleukin (IL)‐1β, IL‐6, tumor necrosis factor‐α (TNFα), interferon‐β (IFNβ), and inducible nitric oxide synthase (NOS2) was up‐regulated 24 hr after the challenge as determined by real‐time RT‐PCR. Pretreatment of the cells with toxin B, which specifically inactivates Rho proteins, enhanced the up‐regulation of gene expression. The extent of this enhancement was both receptor and gene dependent. The enhancing effect of Rho protein inactivation was also evident at the protein level of IL‐6 and NOS2 as reveled by ELISA and immunoblot analyses, respectively. These results suggest that Rho proteins control TLR‐mediated up‐regulation of inflammatory genes in astrocytes by interfering with multiple events along the signaling pathways. © 2008 Wiley‐Liss, Inc.
Striatal transplantation in a rodent model of multiple system atrophy: Effects on L‐Dopa response
Authors: Köllensperger Martin , Stefanova Nadia , Pallua Anton , Puschban Zoe , Dechant Georg , Hainzer Monika , Reindl Markus , Poewe Werner , Nikkhah Guido , Wenning Gregor K. 
Published: December 2008

AbstractProgressive degeneration of striatal projection neurons is thought to account for the loss of L‐Dopa response observed in the majority of patients with the parkinsonian variant of multiple system atrophy (MSA‐P). Here we have investigated the effects of E14 embryonic striatal allografts on dopaminergic responsiveness in the unilateral double‐lesion rat model of MSA‐P by using tests of complex motor behavior. Both sham and graft animals showed an increase in apomorphine‐induced rotations as well as an improvement in cylinder test performance following surgical intervention. In contrast, L‐Dopa responsiveness of stepping behavior was improved only in grafted animals. The restoration of apomorphine‐induced rotation correlated with the P‐zone volume of grafts. Our findings indicate that transplantation of embryonic striatal grafts might, at least to some extent, restore responsiveness to L‐Dopa in tasks of complex motor behavior. Therefore, striatal transplantation should be further defined preclinically as a possible therapeutic option for patients with MSA‐P and a failing L‐Dopa response. © 2008 Wiley‐Liss, Inc.
Clinicopathologic characteristics and outcomes of gastric cancers with the MSI‐H phenotype
Authors: Seo Hyung Min , Chang Yeon Soo , Joo Sun Hyung , Kim Youn Wha , Park Yong‐Koo , Hong Sung Wha , Lee Suk‐Hwan 
Published: December 2008

AbstractObjectivesWe examined the correlation between microsatellite instability (MSI) status and the clinicopathological features and prognostic value in gastric cancer and compared the efficacy of immunohistochemical staining for hMLH1 and hMSH2 with a polymerase chain reaction (PCR)‐based test.MethodsMSI status was examined in 328 consecutive gastric adenocarcinomas using tissue preserved in paraffin blocks. DNA extracted from tumor sections and the corresponding normal tissue was analyzed using PCR at the five microsatellite loci recommended by the National Cancer Institute (NCI). Immunohistochemical staining for hMLH1 and hMSH2 was performed and the results were compared with the MSI status measured using PCR. The relationship of the clinicopathologic variables to MSI status was analyzed.ResultsOf the gastric cancers, 8.2% (n = 27) contained MSI‐H and this was associated with older age (>70 years), distal tumor location, tumor size, and intestinal subtype. Lymphatic and vascular invasion were associated with the disease‐free survival. On immunohistochemical staining, the loss of expression of hMLH1 or hMSH2 was observed in 11% (n = 36). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of immunohistochemical staining were 63.0%, 93.7%, 47.2%, 96.6%, and 91.2%, respectively.ConclusionsGastric cancers with MSI‐H have specific clinicopathologic characteristics, such as older age at diagnosis, distal tumor location, increased tumor size, and intestinal histologic type. However, immunohistochemical staining for hMLH1 and hMSH2 is not as accurate as the PCR‐based MSI test. J. Surg. Oncol. 2009;99: 143–147. © 2008 Wiley‐Liss, Inc.
Stressful life events and posttraumatic stress symptoms in children with cancer
Authors: Currier Joseph M. , Jobe‐Shields Lisa E. , Phipps Sean 
Published: December 2008

AbstractThis study examined the contribution of stressful life events in posttraumatic stress symptoms (PTSS) stemming from childhood cancer among 121 patients. When controlling for demographic characteristics (age, gender, ethnicity, and socioeconomic status), cancer factors (treatment status, time since diagnosis, and cancer type), and intensity of parental PTSS, history of stressful life events in the child's life emerged as a salient correlate of PTSS across the different measures and reporting methods used in the study. Overall, children who had experienced more frequent and severe life stressors endorsed greater PTSS in relation to the cancer experience. Clinical work and future research on children with cancer should focus accordingly on the potential cumulative impact of stressful life events on PTSS.
Balloon Dilation Only Versus Balloon Dilation Plus Stenting for Posttransplantation Biliary Strictures
Authors: Perkins James D. 
Published: December 2008

Abstract

Background and study aims
Biliary strictures are a major cause of morbidity following liver transplantation. In the present prospective comparative trial, we evaluated balloon dilation vs. balloon dilation plus stenting with regard to technical and clinical efficacy as well as complications.

Patients and methods
A total of 32 patients with symptomatic biliary strictures after liver transplantation were assigned to balloon dilation (n = 17) or balloon dilation plus plastic stent placement (n = 15). The main outcome parameter was sustained clinical success defined as an interval of at least 3 months without further endoscopic intervention. Additional outcome parameters were assisted clinical success and treatment failure, as well as procedure-related complications.

Results
The initial technical success and primary clinical success rates in the dilation group were both 100 %; in the stent group, the corresponding rates were 100 % and 93 % (n.s.). The sustained clinical success was 71 % vs. 73 %, respectively (n. s.). The time interval to reach sustained clinical success was 6.1 and 5.1 months, respectively (n. s.). No significant differences were found in assisted clinical success or in treatment failure. Complications were observed in 4.3 % in the dilation group and 13.6 % in the stent group (P < 0.05). Independent of the treatment group, a sustained clinical success in anastomotic strictures was achieved in 100 %, whereas the success rate of strictures of the donor hepatic duct was 50 % and of strictures involving the hilum, only 14 % (P < 0.05).

Conclusions
In patients with biliary strictures after liver transplantation, endoscopic balloon dilation alone was as effective as dilation plus stent placement. Stent placement was associated with a significantly higher complication rate. Endoscopic treatment of strictures of the biliary anastomosis is highly effective, whereas attempts to treat more complex strictures are less promising.
Interaction of Ionic Liquids with Polysaccharides, 8 – Synthesis of Cellulose Sulfates Suitable for Polyelectrolyte Complex Formation
Authors: Gericke Martin , Liebert Tim , Heinze Thomas 
Published: December 2008

AbstractWater‐soluble CS with different DS were synthesized by homogeneous conversion of cellulose (microcrystalline cellulose and spruce sulfite pulp) with different sulfating agents in the ionic liquids BMIMCl, AMIMCl and EMIMAc. N,N‐Dimethylformamide was used as a dipolar aprotic co‐solvent in order to improve the miscibility of the reaction mixture. The CS prepared by the new homogeneous reaction pathway were studied towards the formation of PEC capsules. CS obtained from SSP formed mechanically stable PEC capsules with PolyDADMAC. Exploiting this method, the microencapsulation of glucose oxidase was studied and enzyme activity tests were performed with encapsulated GOD.magnified image
Effect of the Ligand in Atom Transfer Radical Polymerization Reactions Initiated by Photodimers of 9‐Bromoanthracene
Authors: Cohen Nicole A. , Tillman Eric S. , Thakur Sona , Smith Jenell R. , Eckenhoff William T. , Pintauer Tomislav 
Published: December 2008

AbstractSlow initiation from the bridgehead radical in atom transfer radical polymerization (ATRP) reactions initiated by 9‐bromoanthracene photodimers leads to polymers' products possessing high PDI values and higher than expected $\overline M _{\rm n}$ values. We report here the effects of changing the ligand from N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) to the highly active tris[2‐(dimethylamino)ethyl]amine (Me6TREN) or tris[(2‐pyridyl)methyl]amine (TPMA) in an attempt to push the initial equilibrium further toward the initiating bridgehead radical. Overall, the ligand choice was found to add negligible control to the ATRP of styrene with any increase in the rate of initiation offset by an increase in the rate of propagation, leading to anthracene‐labeled polystyrene with similar PDI (≈1.6) and $\overline M _{\rm n}$ values regardless of the ligand choice.magnified image
The Role of Filler Networking in Fatigue Crack Propagation of Elastomers under High‐Severity Conditions
Authors: Klüppel Manfred 
Published: December 2008

AbstractStructural parameters of the filler network have been evaluated by fitting quasi‐static stress/strain cycles to the dynamic flocculation model. It is found that the size of filler clusters as well as the strength of filler–filler bonds increase with filler loading and carbon black activity (specific surface). This correlates with the behavior of the tear resistance obtained for pulsed loading under high‐severity conditions, implying that the characteristics of the filler network govern the fracture properties of filled elastomers. The behavior of the power law exponent of fatigue crack propagation versus tearing energy can be explained by flash temperature effects in the crack tip area.magnified image
Semi‐Interpenetrating Hydrogels of Polyelectrolytes, Polymer‐Metal Complexes and Polymer‐Protected Palladium Nanoparticles
Authors: Kudaibergenov Sarkyt E. , Ibraeva Zhanar E. , Dolya Natalya A. , Musabaeva Binur Kh. , Zharmagambetova Alima K. , Koetz Joachim 
Published: December 2008

AbstractSummary: Semi‐interpenetrating hydrogels (SIHs) of polyelectrolytes consisting of poly(acrylamide) hydrogel (PAAH) as matrix and sodium poly(styrenesulfonate) (NaPSS), poly(N,N′‐dimethyl‐N,N′‐diallylammonium chloride) (PDMDAAC), stoichiometric interpolyelectrolyte complex of NaPSS‐PDMDAAC, and linear polyethyleneimine‐metal complexes (PMC) as well as polymer‐protected palladium nanoparticles were prepared by in situ polymerization, e.g. crosslinked acrylamide chains were formed in aqueous solutions of NaPSS, PDMDAAC, NaPSS‐PDMDAAC (1:1 mol/mol), PMC and palladium nanoparticles protected by poly(N‐vinylpyrrolidone) (PVP), poly‐(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), and linear poly(ethyleneimine) (LPEI) respectively in the presence of N,N′‐methylenebisacrylamide. For each system the equilibrium swelling degree α and the parameters n and k describing the mechanism of water transport into SIHs volume was determined. Catalytic properties of SIHs were studied in allyl alcohol hydrogenation and cyclohexane oxidation reactions.
Oxygen Barrier LDPE/LLDPE/Organoclay Nano‐Composite Films for Food Packaging
Authors: Dadbin Susan , Noferesti Mohsen , Frounchi Masoud 
Published: December 2008

AbstractSummary: This study intends to replace polyethylene multi‐layer films used in food packaging industry with single‐layer polyethylene nanocomposites films. Nanocomposites of LDPE/LLDPE/ montmorillonite organoclay were prepared by melt compounding in a twin extruder and then film blown to prepare thin films. LLDPE‐g‐MA was used as compatibilizer to achieve better interaction between the blend and organoclay. Various compositions of organoclay and compatibilizer were prepared. The structure of nanocomposites was characterized by XRD and TEM. Permeability properties were measured using a permeability measuring set‐up and aspect ratio of the particles was evaluated using permeability data. The results showed that addition of organoclay even at low level (below 5 phr) had significant effect on barrier properties of the nanocomposites. Oxygen permeability decreased by 50% by adding only 3 phr of nanoclay into the blend. Crystalline structure of the nanocomposites was studied by DSC. Addition of clay also led to increase in melting point and somewhat decrease in the crystalline level. Given the fact that crystals are effectively non‐permeable, the concomitant reduction in crystallinity of the blend with decrease in permeability suggests that barrier properties arise from tortuousity of nanoparticles in the blend.
Secondary Flows of Simplified Phan‐Thien Tanner (SPTT) Non‐Linear Viscoelastic Fluid Between Parallel Rotating Disks
Authors: Hashemabadi Seyed Hassan , Mirnajafizadeh Seyed Mohammad 
Published: December 2008

AbstractSummary: The steady state laminar flow of non‐linear viscoelastic fluid with Simplified Phan‐Thien Tanner (SPTT) model between coaxial rotating disks is studied analytically. With linearized stress coefficient in the constitutive equation (SPTT), primary flow and weak secondary flow have been investigated by perturbation techniques while the aspect ratio is very small. Axial and radial velocity profiles arising from secondary flow are completely analyzed for various boundary conditions and properties of the viscoelastic fluid. The results indicate the strong effects of the elasticity and boundary conditions on velocity profiles. The inertial secondary flow consists of a single vortex for co‐rotating disks and two vortices for counter‐rotating disks which is well represented by the approximate analytical solution.
Simulation and Development of Tin‐Free Antifouling Self‐Polishing Coatings
Authors: Monfared H. , Sharif F. , Kasiriha S. M. 
Published: December 2008

AbstractTriButylTin based self‐polishing coatings (TBT‐SPC) were smart solutions to the marine fouling problem. Mechanism of self‐polishing were extensively studied and modelled. The aim of this study is to describe the modeling in details and use simulation results to provide insight into the interaction of temprature and some design parameters and a possible basis for accelerated evaluation of new self‐polishing coatings.
Experimental Observations and Quantitative Predictions of Rheological Properties of Organoclay/Poly(propylene) Nanocomposites at the Startup of Shear Flows
Authors: Rajabian Mahmoud , Naderi Ghasem 
Published: December 2008

AbstractWe study the rheological characteristics of nanocomposites containing nano‐sized plate like particles in a viscoelastic fluid at the startup of steady state in the simple shear flow mode. The nanocomposites of organoclay‐polypropylene with different nanoclay contents were prepared by melt mixing. A rheological equation of state, originally formulated to predict the orientation state and viscoelastic behavior of suspensions of ellipsoidal particles in polymer melts, has been modified to describe the observed phenomena for the nanoclay/poly(propylene) composites. The rotational particle motion and alignment for a group of symmetric ellipsoids with the applied flow field are investigated. Additionally, model calculations of the macroscopic rheological properties for a simple flow case suggest the presence of nano‐particles significantly modify the suspended fluid at volume concentrations as low as 0.5%. The model calculations for the startup viscosity are reasonably in agreement with the experimental results at the experimental range covered in this study. At the shear rate of $\dot \gamma = 1\;s^{ - 1} $, we observe pronounced stress overshoots at the three nanoclay loadings level tested which are found to be related to the fast alignment of the silicate layers with the shear direction in the polymer melt.
Particle Formation by Emulsion Inversion Method: Effect of the Stirring Speed on Inversion and Formation of Spherical Particles
Authors: Aravand Mohammad Ali , Semsarzadeh Mohammad Ali 
Published: December 2008

AbstractSummery: Phase inversion emulsification technique was employed in this work as a practical method to form epoxy particles. The effect of stirring speed on the inversion behaviour and the morphological aspects of the resulting solid epoxy particles are investigated. Emulsion inversion was induced by increasing the amount of initially dispersed deionized water in the presence of a non‐ionic block copolymer surfactant at a fixed concentration. The process of inversion was followed by monitoring the variations in the rotational speed of the stirrer caused by the viscosity variations of the emulsifying system throughout the process. It was shown that the mixing speed plays an important role in controlling the size and size distribution of the resulting emulsion particles. Below a critical stirring speed, spherical particles could not be formed and the inversion process resulted in macroscopically non‐homogeneous multi shape structures. Fully spherical particles were formed above this critical speed. Further increase in the rotational speed of the mixer, significantly reduced the size of these spherical particles with a wide and random size distributions controlled and considerably narrowed by the stirring speed. Dynamic light scattering analysis and scanning electron microscopy were used to study the particle size and size distributions. In addition, study of the rotational speed variations of the stirrer, which is directly related to the viscosity changes of the emulsifying system, revealed that a correlation between the physical aspects of the inversion behaviour and the viscosity changes during the emulsion inversion process could be established.
Synthesizing UHMWPE Using Ziegler‐Natta Catalyst System of MgCl2(ethoxide type)/ TiCl4/tri‐isobutylaluminum
Authors: Jamjah Roghieh , Zohuri Gholam Hossein , Javaheri Mohsen , Nekoomanesh Mehdi , Ahmadjo Saeid , Farhadi Ali 
Published: December 2008

AbstractSummery: A Ziegler‐Natta catalyst of MgCl2 (ethoxide type)/TiCl4 has been synthesized. In order to obtain ultra high molecular weight polyethylene (UHMWPE) tri‐isobutylaluminum which is less active to chain transfer was used as cocatalyst. Slurry polymerization was carried out for the polymerization of ethylene while, dilute solution viscometry was performed for the viscosity average molecular weight (Mv) measurement. The effect of [Al]/[Ti] molar ratio, temperature, monomer pressure and polymerization time on the Mv and productivity of the catalyst have been investigated. The results showed increasing [Al]/[Ti] ratio in the range of 78–117, decreased the Mv of the obtained polymer from 7.8 × 106 to 3.7 × 106 however, further increase of the ratio, resulted in decreased of by much slower rate up to [Al]/[Ti] = 588. The higher pressure in the range of 1–7 bars showed the higher the Mv of the polymer obtained, while increasing temperature in the range of 50 to 90 °C decreased the Mv from 9.3 × 106 to 3.7 × 106. The Mv rapidly increase with polymerization time in the first 15 minutes of the reaction, this increase was slowly up to the end of the reaction (120 min). Increasing [Al]/[Ti] ratio raised productivity of the catalyst in the range studied. Rising reaction temperature from 50 to 75 °C increased the productivity of the catalyst however, further increase in the temperature up to the 90 °C decreased activity of the catalyst. Monomer pressure in the range 1 to 7 bars yields higher productivity of the catalyst. Also by varying polymerization conditions synthesizing of UHMWPE with Mv in the range of 3 × 106 to 9 × 106 was feasible.
Temperature Sensitive Superabsorbent Hydrogels from Poly(N‐t‐butyl acrylamide‐co‐acrylamide) Grafted on Sodium Alginate
Authors: Pourjavadi Ali , Samadi Morasae , Ghasemzadeh Hossein 
Published: December 2008

AbstractTemperature‐sensitive hydrogels based on N‐t‐butylacrylamide (TBA), acrylamide (AAm), and sodium alginate were prepared by free radical polymerization method. Methylenebisacrylamide (MBA) and amonium persulfate (APS) were applied as water soluble crosslinker and initiator, respectively. The chemical structure of the hydrogels was confirmed by FT‐IR spectroscopy and thermogravimetric analysis (TGA) methods. Morphology of the samples was examined by scanning electron microscopy (SEM). By changing the initial TBA/AAm mole ratios, hydrogels with different swelling properties were obtained. The rate parameters were found to be 2.0, 2.4, and 3.5 min for the superabsorbents with AAm/TBA weight ratio of 1.0, 1.3 and 2.0 respectively. The swelling behavior in distilled water and different pH solutions was investigated. A preliminary swelling kinetics and the absorbency under load (AUL) were also studied. At the applied pressure (2.07 kPa), maximum swelling was found to be 17, 19, and 21 (g/g) for the superabsorbent hydrogels with AAm/TBA weight ratios of 1.0, 1.5 and 2.0, respectively.