bluuebunny/crossref_metadata_2025_split huggingface dataset:
An introduction of various spectroscopic methods to identify in vivo metal wear in total knee arthroplasty
Authors: Kovacik M. W. , Gradisar I. A. , Tokash J. C. , Stojilovic N. , Ehrman J. D. , Bender E. T. , Ramsier R. D. 
Published: August 2007

AbstractWhile the industrial community already employs multiple surface analytical techniques to study compositional wearing of various metallic and nonmetallic materials, as yet, these methods have not been widely introduced into the biological community. We report on a novel approach, using the industrial spectroscopic techniques of X‐ray photoelectron spectroscopy, micro‐Raman spectroscopy, and scanning electron microscopy equipped with energy dispersive spectroscopy, to identify the fine wear particulates and other impurities deposited within the knee‐joint following total knee arthroplasty. In this study, synovial fluid was extracted from knee‐joints scheduled for revision of total knee arthroplasty. The small debris flake formed by centrifugation of the fluid was analyzed using the spectroscopic techniques mentioned above. These nondestructive techniques were successful in identifying numerous micron and submicron sized metallic particulates that appear to emanate from both the prosthetic bearing (articulating) surfaces and from backside (nonarticulating) surfaces, even when gross wearing of the prosthetic device was not detectable by direct visual inspection intraoperatively. Most interesting is that the ratio of the in vivo metallic debris is approximately the same ratio as that of the manufactured alloy, indicating prosthetic wearing as opposed to chemical dissolution. More importantly, using these spectroscopic techniques to probe both the surface and below the surface of the synovial deposits, we identify an inhomogeneous distribution of the wear debris. This indicates the need to use multiple techniques in order to adequately identify the elemental composition of the prosthetic wear material. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Biological response of tissues with macrophagic activity to titanium dioxide
Authors: Olmedo Daniel G. , Tasat Deborah R. , Evelson Pablo , Guglielmotti María B. , Cabrini Rómulo L. 
Published: August 2007

AbstractThe titanium dioxide layer is composed mainly of anatase and rutile. This layer is prone to break, releasing particles to the milieu. Therefore, corrosion may cause implant failure and body contamination. We have previously shown that commercial anatase–titanium dioxide (TiO2–anatase) is deposited in organs with macrophagic activity, transported in the blood by phagocytic‐mononuclear cells, and induces an increase in the production of reactive oxygen species (ROS). In this study, we evaluated the effects of rutile–titanium dioxide (TiO2–rutile). Male Wistar rats were injected i.p. with a suspension of TiO2–rutile powder at a dose of 1.60 g/100 g b.w. Six months postinjection, the presence of Ti was assessed in serum, blood cells, liver, spleen, and lung. Titanium was found in phagocytic mononuclear cells, serum, and in the parenchyma of all the organs tested. TiO2–rutile generated a rise in the percentage of reactive cells, which was smaller than that observed when TiO2–anatase was employed in a previous study. Although TiO2–rutile provoked an augmentation of ROS, it failed to induce damage to membrane lipids, possibly due to an adaptive response. The present study reveals that TiO2–rutile is less bioreactive than TiO2–anatase. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A low‐toxic and efficient gene vector: Carboxymethyl dextran‐graft‐polyethylenimine
Authors: Sun Yun‐Xia , Zhang Xian‐Zheng , Cheng Han , Cheng Si‐Xue , Zhuo Ren‐Xi 
Published: August 2007

AbstractIn this study, the low molecular weight branched polyethylenimine (PEI) (800 Da PEI) was grafted to the biodegradable and biocompatible carboxymethyl dextran (CMD) to obtain CMD‐g‐PEI, and the plasmid DNA was complexed with CMD‐g‐PEI polycation to form the polyion complex. The acid‐base titration profile showed that the CMD‐g‐PEI had endosomal disruption capacity, and the agarose gel electrophoresis suggested that the CMD‐g‐PEI could condense DNA efficiently. The transfection efficiency of CMD‐g‐PEI/DNA complexes was measured by luciferase and green fluorescent protein assay in HEK293 cells. The results revealed that the transfection efficiency of CMD‐g‐PEI at the N/P ratios over 30–70 was higher than or comparable to that of the 25 kDa PEI at optimal ratio (N/P = 10). The cytotoxicity of CMD‐g‐PEI as well as 25 kDa PEI was evaluated in NIH3T3 and HEK293 cells, respectively, and it was also found that the cytotoxicity of CMD‐g‐PEI was much lower than that of 25 kDa PEI. The resulted CMD‐g‐PEI with high transfection efficiency and low cytotoxicity have promising applications when used as gene vector. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Differential regulation of endothelial cell adhesion, spreading, and cytoskeleton on low‐density polyethylene by nanotopography and surface chemistry modification induced by argon plasma treatment
Authors: Tajima S. , Chu J.S.F. , Li S. , Komvopoulos K. 
Published: August 2007

AbstractPlasma treatment of polymer surfaces can modify the nanoscale roughness, wettability, and oxygen surface functionalities. However, how these modifications regulate cell behavior is not well understood. The objective of this investigation was to examine adhesion, spreading, and cytoskeleton of vascular endothelial cells seeded on low‐density polyethylene surfaces modified by Ar plasma. In the absence of serum, adhesion and spreading of the cells and actin filament assembly were enhanced by high‐energy Ar plasma‐induced hydrophilicity and formation of CO groups at the surface. Although serum increased cell adhesion and spreading on untreated surfaces for a relatively short period, this behavior was not stable for a long time. In contrast to the untreated polymer surfaces, serum suppressed cell adhesion and spreading on the plasma‐treated surfaces. The preadsorption of albumin from the bovine serum on the polymer surfaces inhibited cell adhesion and spreading. Results demonstrate the differential effects of Ar plasma‐induced surface modifications on endothelial cell behavior and provide insight into complex interactions among polymer surfaces, adsorbed proteins, and cells. The findings of this study have significant implications in surface engineering for vascular repair. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Caspase‐dependent apoptosis induction by targeted expression of DEK in drosophila involves histone acetylation inhibition
Authors: Lee Kyu‐Sun , Kim Dong‐Wook , Kim Ji‐Young , Choo Jong‐Kil , Yu Kweon , Seo Sang‐Beom 
Published: August 2007

AbstractAs a nuclear phosphoprotein, proto‐oncogene protein DEK is capable to changing chromatin structure. DEK was recently identified as an inhibitor of histone acetylation mediated by p300 and PCAF and to facilitate transcriptional repression. To elucidate the biological functions of DEK in vivo, we have constructed transgenic flies that overexpress the human DEK in the developing eye. Transgenic flies developed a severe rough eye phenotype, which is indicative of ectopically induced apoptosis. Genetic and biochemical analyses, including the rescue of the apoptotic phenotype by pan‐caspase inhibitor protein p35 and caspase activity analyses, suggested that DEK induces apoptotic cell death through a caspases‐9 and ‐3 dependent pathway. Using extracts from larval salivary glands, we have determined that the global histone acetylation levels of histone H3 Lys9 and H4 Lys5 were decreased upon DEK overexpression. Using chromatin immunoprecipitation assays, we have demonstrated that overexpression of DEK induced the histone H3 and H4 hypoacetylation of promoter of the antiapoptotic gene bcl‐2. Co‐expression of bcl‐2 also rescued apoptosis and the reduced expression of bcl‐2 gene was analyzed by real‐time PCR. Our results indicate that acidic domain containing protein DEK might have a role in modulating both transcriptional regulation and apoptosis through HAT inhibitory activity. J. Cell. Biochem. 103: 1283–1293, 2008. © 2007 Wiley‐Liss, Inc.
Evaluation of VEGF‐mediated signaling in primary human cells reveals a paracrine action for VEGF in osteoblast‐mediated crosstalk to endothelial cells
Authors: Clarkin Claire E. , Emery Roger J. , Pitsillides Andrew A. , Wheeler‐Jones Caroline P.D. 
Published: August 2007

AbstractCommunication between endothelial and bone cells is crucial for controlling vascular supply during bone growth, remodeling, and repair but the molecular mechanisms coordinating this intercellular crosstalk remain ill‐defined. We have used primary human and rat long bone‐derived osteoblast‐like cells (HOB and LOB) and human umbilical vein endothelial cells (HUVEC) to interrogate the potential autocrine/paracrine role of vascular endothelial cell growth factor (VEGF) in osteoblast:endothelial cell (OB:EC) communication and examined whether prostaglandins (PG), known modulators of both OB and EC behavior, modify VEGF production. We found that the stable metabolite of PGI2, 6‐keto‐PGF1α and PGE2, induced a concentration‐dependent increase in VEGF release by HOBs but not ECs. In ECs, VEGF promoted early ERK1/2 activation, late cyclooxygenase‐2 (COX‐2) protein induction, and release of 6‐keto‐PGF1α. In marked contrast, no significant modulation of these events was observed in HOBs exposed to VEGF, but LOBs clearly exhibited COX‐dependent prostanoid release (10‐fold less than EC) following VEGF treatment. A low level of osteoblast‐like cell responsiveness to exogenous VEGF was supported by VEGFR2/Flk‐1 immunolabelling and by blockade of VEGF‐mediated prostanoid generation by a VEGFR tyrosine kinase inhibitor (TKI). HOB alkaline phosphatase (ALP) activity was increased following long‐term non‐contact co‐culture with ECs and exposure of ECs to VEGF in this system further increased OB‐like cell differentiation and markedly enhanced prostanoid release. Our studies confirm a paracrine EC‐mediated effect of VEGF on OB‐like cell behavior and are the first supporting a model in which prostanoids may facilitate this unidirectional VEGF‐driven OB:EC communication. These findings may offer novel regimes for modulating pathological bone remodeling anomalies through the control of the closely coupled vascular supply. J. Cell. Physiol. 214: 537–544, 2008. © 2007 Wiley‐Liss, Inc.
Design of a birdcage array for lower extremity angiography
Authors: Brown Ryan , Prince Martin R. , Ersoy Hale , Dooley Michael , Ho Bernard Y. , Mareyam Azma , Mohajer Kiyarash , Wang Yi 
Published: August 2007

AbstractPurposeTo investigate the application of a coil array consisting of multiple birdcages for bolus chase magnetic resonance angiography (MRA) of the lower extremities.Materials and MethodsThe prototype consisted of four birdcage coils; two adjacent birdcages for thigh imaging, and two for calf imaging. Decoupling between adjacent coils was achieved using shared capacitors. Bench measurements and MR images were used to evaluate the decoupling scheme. Image signal‐to‐noise ratios (SNR) were compared between the birdcage array and four commercially available coils. Contrast‐enhanced imaging experiments were performed on 10 volunteers and parallel imaging was simulated. This study was approved by the local institutional review board and written informed consent was obtained from each volunteer.ResultsCapacitive decoupling resulted in a reduction in signal leakage. The calf birdcages provided an 84% SNR improvement over a four element array, while the thigh birdcages provided a 53% improvement. Angiographic images illustrated the utility of the coil for peripheral MRA. Parallel imaging was demonstrated with a two‐fold reduction factor.ConclusionBirdcage coils were demonstrated to be valuable for lower extremity imaging due to their homogenous sensitivity, good SNR, and cylindrical geometry. Coupling was controlled using shared capacitors that allowed a single birdcage to encompass each leg individually, providing a novel approach to signal reception for peripheral imaging. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Sentinel lymph node biopsy for breast cancer: How many nodes are enough?
Authors: Zakaria Shaheen , Degnim Amy C. , Kleer Celina G. , Diehl Kathleen A. , Cimmino Vincent M. , Chang Alfred E. , Newman Lisa A. , Sabel Michael S. 
Published: August 2007

AbstractIntroductionSentinel lymph node (SLN) biopsy using blue dye and radioisotope often results in the removal of multiple SLNs. We sought to determine whether there is a point where the surgeon can terminate the procedure without sacrificing accuracy.MethodsOne thousand one hundred ninety‐seven patients from University of Michigan and the Mayo Clinic undergoing SLN biopsy formed the study population. Surgeons removed all SLNs until counts within the axilla were less than 10% of the highest node ex vivo and recorded the order in which they were removed.ResultsThe mean number of SLNs removed per patient was 2.5 (range 1–9). Approximately 42% of patients had three or more lymph nodes removed, while 19% had four or more lymph nodes removed. Eighteen percent of patients (132/725) at University of Michigan and 22% (103/472) at Mayo Clinic had a positive SLN. Ninety‐eight percent (231/235) of patients with lymph node metastases were identified by the 3rd SLN while 100% were identified by the 4th SLN.ConclusionAmong patients undergoing SLN biopsy for breast cancer, the only positive SLN is rarely identified in the 4th or higher node. Terminating the procedure at the 4th node may lower the cost of the procedure and reduce morbidity. J. Surg. Oncol. 2007;96:554–559. © 2007 Wiley‐Liss, Inc.
Novel Biodegradable Poly(1,8‐octanediol malate) for Annulus Fibrosus Regeneration
Authors: Wan Yuqing , Feng Gang , Shen Francis H. , Balian Gary , Laurencin Cato T. , Li Xudong 
Published: August 2007

AbstractA novel elastic scaffold that simulates the deformability of annulus fibrosus (AF) and has good biocompatibility was developed. The scaffold was formed of a malic acid‐based polyester poly(1,8‐octanediol malate) (POM), which was synthesized by direct polycondensation. The tensile strength of POM gradually increased with the extension of the polymerization time, while the degradation rate decreased. Rat AF cells proliferated on the POM films and maintained their phenotype. The 3D scaffold also supported the growth of the AF cells, as confirmed by Safranin‐O and type II collagen staining. POM also demonstrated a good biocompatibility in an in vivo foreign body response assay, an important prerequisite for tissue engineering applications. This study suggests that elastic POM scaffold may be an ideal candidate for AF tissue engineering.magnified image
NLO Behavior of Polymers Containing Y‐Shaped Chromophores
Authors: Carella Antonio , Borbone Fabio , Caruso Ugo , Centore Roberto , Roviello Antonio , Barsella Alberto , Quatela Alessia 
Published: August 2007

AbstractNew polyurethanes containing Y‐shaped chromophores, symmetrical derivatives of 4‐(dicyanomethylene)‐2‐methyl‐6‐[p‐(dimethylamino)styryl]‐4H‐pyran, have been prepared. The polymers show high glass transition temperatures (Tg) and a good thermal stability. SHG measurements on poled polymer films of the synthesized polymers have been carried out and a maximum d33 of 15 pm · V−1 has been found at 1 368 nm fundamental wavelength. Time stability measurements on the most active polymer have shown that after the initial fast relaxation, the d33 value remains constant at 80 °C for 60 d.magnified image
Estimates of the first Neumann eigenvalue and the log‐Sobolev constant on non‐convex manifolds
Authors: Wang Feng‐Yu 
Published: August 2007

AbstractIn this paper a number of explicit lower bounds are presented for the first Neumann eigenvalue on non‐convex manifolds. The main idea to derive these estimates is to make a conformal change of the metric such that the manifold is convex under the new metric, which enables one to apply known results obtained in the convex case. This method also works for more general functional inequalities. In particular, some explicit lower bounds are presented for the log‐Sobolev constant on non‐convex manifolds. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The first Dirichlet eigenvalue of a compact manifold and the Yang conjecture
Authors: Ling Jun 
Published: August 2007

AbstractWe give a new estimate on the lower bound of the first Dirichlet eigenvalue of a compact Riemannian manifold with negative lower bound of Ricci curvature and provide a solution for a conjecture of H. C. Yang. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Possibilities and extension of XRD material response analysis in failure research for the advanced evaluation of the damage level of Hertzian loaded components
Authors: Gegner J. , Nierlich W. , Brückner M. 
Published: August 2007

AbstractDue to clearly distinguishable damage symptoms, it is differentiated between the surface and sub‐surface failure mode of rolling bearings. Material states red out by X‐ray diffraction (XRD) residual stress measurements point to a variety of loading conditions especially at raceway surfaces that are associated with several competing failure mechanisms. The corresponding lifetime reduction can range from the lower fatigue strength region to material ratcheting in extreme cases. Relevant position of the microstructural changes and nature of the failure mechanisms are characterized. The time alteration of the XRD material parameters measured at or near the surface and at the depth of the maximum equivalent stress correlates, in a different manner, with the statistical parameter of the 10 % bearing life. Both failure modes are illustrated by concrete examples. Contaminated lubricant and boundary lubrication, which represent practically important surface‐induced failures, are discussed in more detail. Gray staining, i.e. shallow pitting, often occurs without distinct indication of global material aging by means of XRD characteristics. Here, scanning electron microscopy observations and electron microprobe analyses point to corrosion fatigue as acting surface failure mechanism. The interaction between material and lubricant under complex loading regimes particularly of mixed friction and corrosion opens further failure research areas in the field of tribology.
Über die Beanspruchung oberflächennaher Werkstoffbereiche von Zahnflanken bei Voll‐ und Mangelschmierung
Authors: Schlicht H. , Broszeit E. 
Published: August 2007

AbstractBei Zahnradpaarungen, die längere Zeit beansprucht sind, entstehen an den Flanken häufig Risse. Deren Verteilung und deren Ausrichtung zur Flankenoberfläche lassen sich aus der Kinematik des Abrollens erklären. Die Risse bilden zur Oberfläche einen Winkel zwischen 20 ° und 40 ° und sind den auftretenden Tangentialspannungen entgegengesetzt. Nur im negativen Schlupfbereich wachsen die Risse weiter zu Sekundärrissen; vorwiegend dort kommt es zu Ausbrüchen.Die übliche Berechnung der Werkstoffbeanspruchung oberflächennaher Bereiche aus der Hertz`schen Pressungsverteilung für die Normalspannungen kombiniert mit dem Coulomb`schen Reibungsgesetz für die Tangentialspannungen liefert keinen Hinweis auf einen bevorzugt gefährdeten Flankenbereich mit negativem Schlupf. Die unterschiedlichen Schadensphänomene lassen sich jedoch aus der EHD‐Strömungshypothese erklären. Diese Hypothese macht deutlich, dass die Schmierstoffströmung zusätzliche Beanspruchungen verursacht, die die Lebensdauer beeinflussen und den nach Hertz ermittelten Wert verkürzen.
Botulinum toxin treatment of lateral axial dystonia in parkinsonism
Authors: Bonanni Laura , Thomas Astrid , Varanese Sara , Scorrano Vincenzo , Onofrj Marco 
Published: August 2007

AbstractLateral axial dystonia (LAD) has been described in patients with Parkinson's disease (PD), but treatment might be more controversial than treatment of LAD in other neurological conditions. Our study was designed as a blinded cross‐over with botulinum toxin (BTX) and placebo in order to investigate the efficacy of BTX in PD LAD. Nine patients with LAD who failed to experience benefit from oral medications were randomly assigned to 2 groups, 4 patients received BTX and 5 placebo as a first treatment, and were switched‐over to BTX or placebo in the following treatment session, performed 3 months after the first session. Each patient was evaluated at baseline, 2 and 4 weeks after injection and after 3 months follow‐up with the Trunk Dystonia Disability Scale (TDDS), a Visual Analogue Scale (VAS) and a goniometric measurement of the lateral displacement. Patients were videotaped at each visit. None of the patients of the placebo group experienced benefit from treatment. BTX treatment was effective in 6 patients. One patient reported subjective benefit, with improvement of VAS score and mild improvement of TDDS score, but with no improvement of flexion degree. Two patients did not report any benefit. Four patients opted to continue to receive BTX treatment for 2 years after the cross‐over study. Our study shows that BTX could be considered a possible treatment for LAD in parkinsonism. © 2007 Movement Disorder Society
High‐resolution time‐resolved contrast‐enhanced MR abdominal and pulmonary angiography using a spiral‐TRICKS sequence
Authors: Du Jiang , Bydder Mark 
Published: August 2007

AbstractBoth high spatial resolution and high temporal resolution are desirable for contrast‐enhanced magnetic resonance angiography (CE‐MRA) in order to depict the arterial vasculature. In this work a fast MR pulse sequence (spiral time‐resolved imaging with contrast kinetics (Spiral‐TRICKS)) with spiral readout in‐plane and Cartesian slice encoding was developed whereby the slices are partitioned into multiple regions and acquired in the order used with the TRICKS sequence. The combination of highly efficient spiral sampling with TRICKS acquisition significantly reduced imaging time requirements. A unit second temporal reconstructed frame rate could be achieved for three‐dimensional (3D) CE‐MRA without undersampling of the spiral trajectories. Image quality was improved through spiral trajectory measurement and field‐map correction. Phantom and volunteer studies were performed to demonstrate the feasibility of this technique. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Kinetic assessment of breast tumors using high spatial resolution signal enhancement ratio (SER) imaging
Authors: Li Ka‐Loh , Henry Roland G. , Wilmes Lisa J. , Gibbs Jessica , Zhu Xiaoping , Lu Ying , Hylton Nola M. 
Published: August 2007

AbstractThe goal of this study was to investigate the relationship between an empirical contrast kinetic parameter, the signal enhancement ratio (SER), for three‐timepoint, high spatial resolution contrast‐enhanced (CE) MRI, and a commonly analyzed pharmacokinetic parameter, kep, using dynamic high temporal resolution CE‐MRI. Computer simulation was performed to investigate: 1) the relationship between the SER and the contrast agent concentration ratio (CACR) of two postcontrast timepoints (tp1 and tp2); 2) the relationship between the CACR and the redistribution rate constant (kep) based on a two‐compartment pharmacokinetic model; and 3) the sensitivity of the relationship between the SER and kep to native tissue T1 relaxation time, T10, and to errors in an assumed vascular input function. The relationship between SER and kep was verified experimentally using a mouse model of breast cancer. The results showed that a monotonic mathematical relationship between SER and kep could be established if the acquisition parameters and the two postinjection timepoints of SER, tp1, tp2, were appropriately chosen. The in vivo study demonstrated a close correlation between SER and kep on a pixel‐by‐pixel basis (Spearman rank correlation coefficient = 0.87 ± 0.03). The SER is easy to calculate and may have a unique role in breast tissue characterization. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.