bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of unruptured cerebral artery aneurysms by MRA at 3.0 tesla: comparison with multislice helical computed tomographic angiography
Authors: Numminen Jussi , Tarkiainen Antti , Niemelä Mika , Porras Matti , Hernesniemi Juha , Kangasniemi Marko 
Published: April 2011

Background Computed tomographic angiography (CTA) has become the primary non-invasive method for detection of cerebral artery aneurysms in many neurovascular centers. Purpose To compare MR-angiography at a 3.0 tesla (3T) scanner to CTA in the detection of unruptured intracranial aneurysms. Material and Methods CTA and 3T MRA data from 60 patients were evaluated. CTA was obtained with a 4–16-row helical CT-scanner after administration of 120 cc intravenous contrast agent, MRA was performed by a 3T MR-scanner using time-of-flight pulse sequence. Results Fifty-five cerebral artery aneurysms were detected by MRA and 47 aneurysms by CTA. Most of the aneurysms detected by MRA but not by CTA were small internal carotid artery (ICA) aneurysms. Bone structures and venous enhancement deteriorated CTA accuracy, especially in skull base. In one patient a fairly large anterior communicating artery aneurysm was not visible in MRA due to spin saturation, although it was clearly visualized in CTA. After contrast injection the aneurysm was also seen in MRA. Although the overall image quality of MRA and CTA were comparable, MRA was more susceptible to artifacts and thus re-formatted surface-shaded volume rendered 3-dimensional images of aneurysms from MRA were inferior compared to those from CTA. Conclusion MRA at 3T appears to be at least as sensitive as CTA in the detection of unruptured cerebral artery aneurysms, however image quality control is crucial and contrast agent enhances visualization of complex and large aneurysms.
Focal time-to-peak changes on perfusion MRI in children with Moyamoya disease: correlation with conventional angiography
Authors: Choi Hyun Seok , Kim Dong-Seok , Shim Kyu-Won , Kim Jinna , Kim Eun Soo , Lee Seung-Koo 
Published: April 2011

Background Moyamoya disease is a chronic progressive steno-occlusion of the distal internal carotid arteries with unknown etiology. As the classical presentation of childhood Moyamoya disease is ischemic stroke, cerebral hemodynamic evaluation is important for patient selection for surgery to prevent recurrent ischemic attacks. Perfusion MR imaging has been applied to evaluate cerebral hemodynamics. Purpose To correlate the ‘basal time-to-peak preservation sign’, ‘auto-synangiosis sign’, and ‘posterior involvement sign’ on time-to-peak map of perfusion MRI with catheter angiography. Material and Methods Thirty-four children (6.91 ± 3.08 years) with Moyamoya disease who underwent both perfusion-weighted MRI and catheter angiography were enrolled in this study. Given catheter angiography as a reference standard, basal time-to-peak preservation sign, auto-synangiosis sign, and posterior involvement sign were evaluated on time-to-peak maps. Results The basal time-to-peak preservation sign was accurate for the diagnosis of childhood Moyamoya disease; both sensitivity and specificity were 100%. The auto-synangiosis sign showed lower sensitivity (65%), however, with an acceptable specificity (98%). The posterior involvement sign showed lower sensitivity (61%) but had an acceptable specificity (96%). Conclusion The basal time-to-peak preservation sign may be a universal finding in childhood Moyamoya disease. The auto-synangiosis and posterior involvement sign may be useful in determining transdural collateral status and posterior circulation involvement in childhood Moyamoya disease.
Modelling and Searching of Combinatorial Spaces Based on Markov Logic Networks
Authors: Biba Marenglen , Ferilli Stefano , Esposito Floriana 
Published: April 2011

Markov Logic Networks (MLNs) combine Markov networks (MNs) and first-order logic by attaching weights to first-order formulas and using these as templates for features of MNs. Learning the structure of MLNs is performed by state-of-the-art methods by maximizing the likelihood of a relational database. This leads to suboptimal results for prediction tasks due to the mismatch between the objective function (likelihood) and the task of classification (maximizing conditional likelihood (CL)). In this paper we propose two algorithms for learning the structure of MLNs. The first maximizes the CL of query predicates instead of the joint likelihood of all predicates while the other maximizes the area under the Precision-Recall curve (AUC). Both algorithms set the parameters by maximum likelihood and choose structures by maximizing CL or AUC. For each of these algorithms we develop two different searching strategies. The first is based on Iterated Local Search and the second on Greedy Randomized Adaptive Search Procedure. We compare the performances of these randomized search approaches on real-world datasets and show that on larger datasets, the ILS-based approaches perform better, both in terms of CLL and AUC, while on small datasets, ILS and RBS approaches are competitive and RBS can also lead to better results for AUC.
Science Visual Literacy: Learners' Perceptions and Knowledge of Diagrams
Authors: McTigue Erin M. , Flowers Amanda C. 
Published: April 2011

Constructing meaning from science texts relies not only on comprehending the words but also the diagrams and other graphics. The goal of this study was to explore elementary students' perceptions of science diagrams and their skills related to diagram interpretation. 30 students, ranging from second grade through middle school, completed a diagram sorting task and a follow‐up short interview regarding four versions of a water cycle diagram selected from school science texts. Additionally, 6 students participated in follow‐up longer interviews about diagram interpretation.Results indicate that students valued diagrams with high levels of organization and significant amounts of information. However, students were frequently confused regarding specific conventions of diagram design, such as arrows, and did not fully understand the function of diagrams in science texts. Implications for teachers include methods for assessing students' diagram interpretation skills and explicit instruction in analyzing diagrams.
Thermal Properties and Electrical Conductivity of Graft Copolymers from Polystyrene and Polyvinyl Propionate with Polyaniline
Authors: Hosseini S. H. , Musavi S. M. 
Published: April 2011

AbstractA synthesized graft copolymer from polystyrene (PS) and polyvinyl propionate (PVPr) with polyaniline (PANi) with suitable electrical properties, thermal resistance, solubility and processability was optimized. Samples were prepared in the form of smooth and thin films. Four-point probe method was adapted to examine electrical DC conductivity. It was found that the electrical conductivity and thermal stability of copolymers were increased, but their processability and solubility decreased when PANi increased. Thermal stability of copolymers was investigated by Differential Scanning Calorimetry (DSC) and Thermal Gravimetrical Analysis (TGA). The prepared copolymers were much more thermally stable, soluble, flexible and ability to form a film than polyaniline, polystyrene and polyvinyl propionate. An irreversible exothermic transition was observed by DSC, which is believed to be an indication of cross-linking. Percentage of grafted PANi electrical conductivities of PS-g-PANi and PVPr-g-PANi have been examined and produced conductivities, 3.3 × 10−2 and 4.6 × 10−2 S/cm respectively.
Opto-thermo-mechanical Characterization for Polyester and Polyamide Surgical Sutures
Authors: EL-Farahaty K. A. , Seisa E. A. , El-Sheikh S. G. 
Published: April 2011

Abstract
This work studies the opto-thermo-mechanical properties of two different surgical sutures using interferometry. The polarizing Pluta interference microscope combined with opto-thermo-mechanical (OTM) device were used to study the effect of drawing on monofilament polyester (PET) and polyamide (PA) surgical sutures at room temperature. The variation of the refractive indices and the birefringence of both PET and PA sutures with different draw ratios were determined. The resulting data was used to calculate the optical orientation function and the average work per chain. The stress–strain curve was studied to estimate some mechanical parameters; yield stress, yield strain, Young's modulus and strain optical coefficient. The variations of the refractive the index profile were calculated for different draw ratios. In addition we studied the effect of temperature, during the drawing process, on monofilament PET suture. The obtained results provide important data for better characterization of suture materials.
Investigation of the Moldability Parameters of PEG Based Steatite Feedstocks by Powder Injection Molding
Authors: Erguney S. , Karatas C. , Unal H. I. , Saritas S. 
Published: April 2011

Abstract
In powder injection molding (PIM) barrel temperature, injection pressure and injection rate are important parameters for the molding of powder-binder mixtures. Improperly selected parameters lead to undesired problems such as separation of the powder-binder mixture and formation of collapses and cracks on the structure of the molded parts. In this study, steatite feedstocks based on PEG (polyethylene glycol) binders were injection molded into rectangular shape, ordered thickness with steps and zig-zag shaped mold cavities. The effects of the temperature and pressure of injection, rate of filling, temperature of the mold wall and geometry of the mold cavities were investigated. The optimum molding parameters of the feedstocks for the zig-zag shaped mold were determined to be an injection pressure of 80 to 140 MPa, a barrel temperature of 190 to 230°C, an injection rate of 5–25 · 10−6 m3 s−1 and a mold wall temperature of 32°C.
Melting in a Single Screw Extruder: Experiments and 3D Finite Element Simulations
Authors: Altınkaynak A. , Gupta M. , Spalding M. A. , Crabtree S. L. 
Published: April 2011

Abstract
The melting of an ABS resin was simulated using a three-dimensional finite element simulation of the two-phase flow in the compression section of a single-screw extruder. Screw freezing experiments were also conducted to compare the numerical predictions with the corresponding experimental data. Numerical simulations as well as experiments exhibited the Maddock melting mechanism and numerical predictions were in good agreement with the corresponding experimental data. The sensitivity of the melting profile to various material properties and processing conditions was numerically analyzed. With a constant flow rate enforced at the entrance of the screw channel, the screw and barrel temperature were found to have a minor effect on the melting profile. However, these parameters were found to have a significant effect on the predicted pressure profile along the screw channel. When the zero-traction boundary condition was imposed at the entrance of the screw channel, a change in the screw or barrel temperature affected the flow rate in the screw channel, which resulted in a significant change in the solid fraction at the same cross-section.
Poly(ethylene-co-butylene)-b-(styrene-ran-maleic anhydride)2 Compatibilizers via Nitroxide Mediated Radical Polymerization
Authors: Lessard B. , Aumand-Bourque C. , Chaudury R. , Gomez D. , Haroon A. , Ibrahimian N. , Mackay S. , Noel M.-C. , Patel R. , Sitaram S. , Valla S. , White B. , Maric M. 
Published: April 2011

Abstract
Telechelic poly(ethylene-ran-butylene) initiator terminated with [tert-butyl[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino] nitroxide groups (PEB-(SG1)2) was used to initiate the controlled radical copolymerization of maleic anhydride (MA) and styrene (ST). The ST/MA copolymerizations were performed in 1,4-dioxane at 110°C and resulted in PEB-b-P(ST-ran-MA)2 triblock copolymers with relatively narrow molecular weight distributions

(

M
¯

m

/

M
¯

n

≈
1.5

)

. Gel permeation chromatography (GPC) indicated that the initiator used was ≈93% efficient. The resulting copolymers were then blended as 20 wt.% dispersions in nylon 6 (PA6) at 230°C. With as little as 10 mol.% of MA in the feed to make the PEB-b-P(ST-ran-MA)2, blends were deemed dynamically compatibilized based on the reduced particle size. All of the PEB-b-P(ST-ran-MA)2/PA6 blends resulted in a minor phase particle size

D
¯

vs

=
0.1

μm while the PEB-b-P(ST)/PA6 blend had

D
¯

vs

=
1.15

μm (i.e. no MA in the copolymer). Tensile testing revealed yield stresses and strains decreased steadily from pure PA6 to non-reactive PEB-b-P(ST)2/PA6 to PEB-b-P(ST-ran-MA)2/PA6. However, no difference in tensile properties was observed between PEB-b-P(ST-ran-MA)2/PA6 samples made from PEB-b-P(ST-ran-MA)2 copolymer of varying MA content.
Formation and Biodegradation of Polyethylene-based Electret Films
Authors: Goldade V. A. , Pinchuk L. S. , Ermolovich O. A. , Goncharova E. P. , Sytsko V. E. 
Published: April 2011

Abstract
Intensive development of packing industry in response to the needs of modern society has aggravated the global situation with recovery of polymer wastes. One of the trends that may alleviate this problem is manufacture of ecologically friendly biodegradable polymeric films. Such films undergo accelerated destruction after burial under the action of soil microorganisms. The factor that speeds up biodestruction of the films in soil is the electric field of their own. The available experimental data have proved that the kinetics of biodestruction of polyethylene films, including starch-filled and inorganic salt-filled ones, alters significantly after such film transfer to electret state.
OSTEOGENESIS OF ADIPOSE-DERIVED STEM CELLS ON THREE-DIMENSIONAL, MACROPOROUS GELATIN–HYALURONIC ACID CRYOGELS
Authors: Tsung Liao Han , Chang Kun-Hung , Chen Jyh Ping 
Published: April 2011

Aim. Macroporous sponge-like gelatin–hyaluronic acid (Gl–HA) scaffolds cross-linked by EDC were produced using cryogelation technology, which allows for the preparation of highly porous scaffolds without compromising their mechanical properties, and is a more cost-efficient process than freeze drying. The aim of this study is to evaluate the osteogenic potential of porcine adipose-derived stem cells (PADSCs) in GI–HA cryogel. Method. The character of the GI–HA cryogel was evaluated. The pore size and the microstructure were observed using scanning electron microscope (SEM). The swelling ratio was measured. The PADSCs were harvested and isolated from pig inguinal area. Then, the GI–HA cryogel was seeded with PADSCs. The cryogel/ASCs mixture was cultured in osteogenic medium for 0, 3, 7, 14, and 21 days. The cell proliferation was measured by MTS. The RT-PCR of specific osteogenic gene expression such as osteocalcin (OC), RUNX2 was used to assess the osteogenic ability. The SEM was used to observe the interaction between scaffold and cells. Energy dispersive spectrum (EDS) was used to analyze the mineralization around cells. Results. The pore size was variable between 200 and 369 μm. The swelling ratio was around 8.67 ± 1.669%. The cell proliferation was increasing along with the increase of induction periods. The expression of early gene of RUNX2 and late gene of OC mean that the PADSCs were differentiated well into osteoblasts within the cryogels. The SEM detailed that the PADSCs cell can proliferate well in the pore of GI–HA scaffold. The EDS also demonstrated the mineralization of PADSCs in GI–HA scaffold after induction. Conclusions. To conclude, the PADSCs can proliferate and differentiate well into osteoblasts in the three-dimensional, porous, GI–HA cryogel.
Priming of Eosinophils by GM-CSF Is Mediated by Protein Kinase CβII-Phosphorylated L-Plastin
Authors: Pazdrak Konrad , Young Travis W. , Straub Christof , Stafford Susan , Kurosky Alexander 
Published: April 2011

Abstract
The priming of eosinophils by cytokines leading to augmented response to chemoattractants and degranulating stimuli is a characteristic feature of eosinophils in the course of allergic inflammation and asthma. Actin reorganization and integrin activation are implicated in eosinophil priming by GM-CSF, but their molecular mechanism of action is unknown. In this regard, we investigated the role of L-plastin, an eosinophil phosphoprotein that we identified from eosinophil proteome analysis. Phosphoproteomic analysis demonstrated the upregulation of phosphorylated L-plastin after eosinophil stimulation with GM-CSF. Additionally, coimmunoprecipitation studies demonstrated a complex formation of phosphorylated L-plastin with protein kinase CβII (PKCβII), GM-CSF receptor α-chain, and two actin-associated proteins, paxilin and cofilin. Inhibition of PKCβII with 4,5-bis(4-fluoroanilino)phtalimide or PKCβII-specific small interfering RNA blocked GM-CSF–induced phosphorylation of L-plastin. Furthermore, flow cytometric analysis also showed an upregulation of αMβ2 integrin, which was sensitive to PKCβII inhibition. In chemotaxis assay, GM-CSF treatment allowed eosinophils to respond to lower concentrations of eotaxin, which was abrogated by the above-mentioned PKCβII inhibitors. Similarly, inhibition of PKCβII blocked GM-CSF induced priming for degranulation as assessed by release of eosinophil cationic protein and eosinophil peroxidase in response to eotaxin. Importantly, eosinophil stimulation with a synthetic L-plastin peptide (residues 2–19) phosphorylated on Ser5 upregulated αMβ2 integrin expression and increased eosinophil migration in response to eotaxin independent of GM-CSF stimulation. Our results establish a causative role for PKCβII and L-plastin in linking GM-CSF–induced eosinophil priming for chemotaxis and degranulation to signaling events associated with integrin activation via induction of PKCβII-mediated L-plastin phosphorylation.
Microparticles (Ectosomes) Shed by Stored Human Platelets Downregulate Macrophages and Modify the Development of Dendritic Cells
Authors: Sadallah Salima , Eken Ceylan , Martin Perrine J. , Schifferli Jürg A. 
Published: April 2011

Abstract
Microparticles (MP) shed by platelets (PLT) during storage have procoagulant activities, but little is known about their properties to modify inflammation or immunity. In this study, we studied the capacity of MP present in PLT concentrates to alter the function of macrophages and dendritic cells (DC). The size of the purified MP was between 100 and 1000 nm, and they expressed phosphatidylserine; surface proteins of PLT (CD61, CD36, CD47), including complement inhibitors (CD55, CD59), but not CD63; and proteins acquired from plasma (C1q, C3 fragments, factor H). These characteristics suggest that the MP shed by PLT are formed by budding from the cell surface, corresponding to ectosomes. The purified PLT ectosomes (PLT-Ect) reduced the release of TNF-α and IL-10 by macrophages activated with LPS or zymosan A. In addition, PLT-Ect induced the immediate release of TGF-β from macrophages, a release that was not modified by LPS or zymosan A. Macrophages had a reduced TNF-α release even 24 h after their exposure to PLT-Ect, suggesting that PLT-Ect induced a modification of the differentiation of macrophages. Similarly, the conventional 6-d differentiation of monocytes to immature DC by IL-4 and GM-CSF was modified by the presence of PLT-Ect during the first 2 d. Immature DC expressed less HLA-DP DQ DR and CD80 and lost part of their phagocytic activity, and their LPS-induced maturation was downmodulated when exposed to PLT-Ect. These data indicate that PLT-Ect shed by stored PLT have intrinsic properties that modify macrophage and DC differentiation toward less reactive states.
Staphylococcus aureusBiofilms Prevent Macrophage Phagocytosis and Attenuate Inflammation In Vivo
Authors: Thurlow Lance R. , Hanke Mark L. , Fritz Teresa , Angle Amanda , Aldrich Amy , Williams Stetson H. , Engebretsen Ian L. , Bayles Kenneth W. , Horswill Alexander R. , Kielian Tammy 
Published: April 2011

AbstractBiofilms are complex communities of bacteria encased in a matrix composed primarily of polysaccharides, extracellular DNA, and protein. Staphylococcus aureus can form biofilm infections, which are often debilitating due to their chronicity and recalcitrance to antibiotic therapy. Currently, the immune mechanisms elicited during biofilm growth and their impact on bacterial clearance remain to be defined. We used a mouse model of catheter-associated biofilm infection to assess the functional importance of TLR2 and TLR9 in the host immune response during biofilm formation, because ligands for both receptors are present within the biofilm. Interestingly, neither TLR2 nor TLR9 impacted bacterial density or inflammatory mediator secretion during biofilm growth in vivo, suggesting that S. aureus biofilms circumvent these traditional bacterial recognition pathways. Several potential mechanisms were identified to account for biofilm evasion of innate immunity, including significant reductions in IL-1β, TNF-α, CXCL2, and CCL2 expression during biofilm infection compared with the wound healing response elicited by sterile catheters, limited macrophage invasion into biofilms in vivo, and a skewing of the immune response away from a microbicidal phenotype as evidenced by decreases in inducible NO synthase expression concomitant with robust arginase-1 induction. Coculture studies of macrophages with S. aureus biofilms in vitro revealed that macrophages successful at biofilm invasion displayed limited phagocytosis and gene expression patterns reminiscent of alternatively activated M2 macrophages. Collectively, these findings demonstrate that S. aureus biofilms are capable of attenuating traditional host proinflammatory responses, which may explain why biofilm infections persist in an immunocompetent host.
The Pleckstrin Homology Domain in the SKAP55 Adapter Protein Defines the Ability of the Adapter Protein ADAP To Regulate Integrin Function and NF-κB Activation
Authors: Burbach Brandon J. , Srivastava Rupa , Ingram Melissa A. , Mitchell Jason S. , Shimizu Yoji 
Published: April 2011

Abstract
Adhesion and degranulation promoting adapter protein (ADAP) is a multifunctional hematopoietic adapter protein that regulates TCR-dependent increases in both integrin function and activation of the NF-κB transcription factor. Activation of integrin function requires both ADAP and the ADAP-associated adapter Src kinase-associated phosphoprotein of 55 kDa (SKAP55). In contrast, ADAP-mediated regulation of NF-κB involves distinct binding sites in ADAP that promote the inducible association of ADAP, but not SKAP55, with the CARMA1 adapter and the TAK1 kinase. This suggests that the presence or absence of associated SKAP55 defines functionally distinct pools of ADAP. To test this hypothesis, we developed a novel SKAP–ADAP chimeric fusion protein and demonstrated that physical association of ADAP with SKAP55 is both sufficient and necessary for the rescue of integrin function in ADAP-deficient T cells. Similar to wild-type ADAP, the SKAP–ADAP chimera associated with the LFA-1 integrin after TCR stimulation. Although the SKAP–ADAP chimera contains the CARMA1 and TAK1 binding sequences from ADAP, expression of the chimera does not restore NF-κB signaling in ADAP−/− T cells. A single point mutation in the pleckstrin homology domain of SKAP55 (R131M) blocks the ability of the SKAP–ADAP chimera to restore integrin function and to associate with LFA-1. However, the R131M mutant was now able to restore NF-κB signaling in ADAP-deficient T cells. We conclude that integrin regulation by ADAP involves the recruitment of ADAP to LFA-1 integrin complexes by the pleckstrin homology domain of SKAP55, and this recruitment restricts the ability of ADAP to interact with the NF-κB signalosome and regulate NF-κB activation.