bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase transformation, roughness, and microhardness of artificially aged yttria‐ and magnesia‐stabilized zirconia femoral heads
Authors: Roy M.E. , Whiteside L.A. , Katerberg B.J. , Steiger J.A. 
Published: June 2007

AbstractYttria‐stabilized zirconia ceramic (Y‐TZP) has been used in total hip arthroplasty for many years but is susceptible to low‐temperature aging. Medical‐grade magnesia‐stabilized zirconia (Mg‐PSZ) is less commonly used; however, it has been shown to resist phase transformation. The purpose of this study was to directly compare the effects of artificial aging on phase transformation, surface roughness, and Vickers microhardness on Y‐TZP and Mg‐PSZ femoral heads. Y‐TZP and Mg‐PSZ heads were artificially aged in an autoclave in stages up to a total of 49 h. The surface roughness of Y‐TZP significantly increased with each stage of artificial aging. Y‐TZP heads aged for 49 h had a significantly higher monoclinic phase concentration and roughness, and a significantly lower microhardness, than nonaged Y‐TZP heads. Artificial aging also caused the surface of Y‐TZP to exhibit a lumpy “orange peel”‐like appearance with a significantly higher mean peak height, suggesting that artificial aging causes individual grains to be pushed out of the surface. In contrast, artificial aging did not significantly affect the properties of Mg‐PSZ heads. These findings suggest that Mg‐PSZ is a satisfactory material for orthopaedic implant use, while Y‐TZP, in the form tested, is not adequately stable for use as a bearing surface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Mirk/Dyrk1B in cancer
Authors: Friedman Eileen 
Published: June 2007

AbstractMirk/Dyrk1B is a member of a conserved family of serine/threonine kinases which are activated by intramolecular tyrosine phosphorylation, and which mediate differentiation in different tissues—Mirk in skeletal muscle, Dyrk1A in the brain, etc. One role of Mirk in skeletal muscle differentiation is to block cycling myoblasts in the G0 quiescent state by modification of cell cycle regulators, while another role of Mirk is to limit apoptosis in fusing myoblasts. Amplification of the Mirk gene, upregulation of Mirk expression and/or constitutive activation of this kinase have been observed in several different types of cancer. If coupled with a stress condition such as serum starvation which induces a quiescent state, depletion of Mirk by RNA interference using either synthetic duplex RNAi's or pSilencer‐encoded RNAi's have decreased colony formation of different cancer cell lines and enhanced apoptosis induced by chemotherapeutic drugs. Mirk is activated by phosphorylation by the stress‐activated SAPK kinases MKK3 and MKK6. Our working hypothesis is that Mirk is activated by this pathway in response to various stresses, and then acts as a checkpoint kinase to arrest damaged tumor cells in a quiescent state and allow cellular repair. Pharmacological inhibition of Mirk may enhance the anti‐tumor effect of chemotherapeutic drugs. J. Cell. Biochem. 102: 274–279, 2007. © 2007 Wiley‐Liss, Inc.
US‐guided percutaneous needle biopsy of the spleen using 18‐gauge versus 21‐gauge needles
Authors: Liang Ping , Gao Yangyan , Wang Yang , Yu Xiaoling , Yu Dejiang , Dong Baowei 
Published: June 2007

AbstractPurposeTo compare the techniques of sonographically (US)‐guided percutaneous needle biopsy of the spleen using 18‐gauge and 21‐gauge needles.MethodsForty‐two patients undergoing 43 spleen biopsy procedures for focal lesions (n = 27 [16 single, 11 multiple]) or diffuse splenomegaly (n = 15) were analyzed. Two groups were divided randomly according to needle type: group 1 comprised 25 patients biopsied with an 18‐gauge cutting needle for histologic examination; group 2 comprised 17 patients biopsied with a 21‐gauge needle for histologic and cytologic examinations. Diagnostic accuracy, complication rate, and number of needle passes were compared between the 2 groups.ResultsCorrect histopathologic diagnosis was obtained in 36 cases, whereas incorrect diagnosis occurred in 6 cases. The accuracy of US‐guided spleen biopsy in this series was 85.7%, with 1 patient (2.4%) having postprocedural hemorrhage. Compared with the 21‐gauge needle, the 18‐gauge needle had higher diagnostic accuracy (P < 0.05), required fewer needle passes (P < 0.05), and there was no significant difference in overall complication rate.ConclusionBecause biopsy with an 18‐gauge needle yields larger and unfragmented samples with higher diagnostic rate compared with a 21‐gauge needle, and no increased rate of major complication requiring surgical intervention, it may be advantageous to use an 18‐gauge cutting needle in the US‐guided needle biopsy of splenic lesions. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Deconstructing the pharyngeal metamere
Authors: Graham Anthony 
Published: June 2007

AbstractA prominent feature of all vertebrate embryos is the presence of a series of bulges on the lateral surface of the head, the pharyngeal arches. These structures constitute a metameric series, with each arch forming a similar set of derivatives. Significantly, the development of the pharyngeal arches is complex as it involves interactions between disparate embryonic cell types: ectoderm, endoderm, mesoderm and neural crest. It is becoming increasingly apparent that the development of the pharyngeal metamere revolves around the pharyngeal endoderm. The segmentation of this tissue is central to the generation of the arches. The pharyngeal endoderm also provides positional cues for the neural crest, and is involved in the induction of a number of components of the pharyngeal metamere. The segmentation of the pharyngeal endoderm has also been key to the evolution of pharyngeal metamerism. It is likely that endodermal segmentation is a deuterostome characteristic and that this basic pattern was sequentially modified and over time the more complex pharyngeal metamere of vertebrates emerged. J. Exp. Zool. (Mol. Dev. Evol.) 310B:336–344, 2008. © 2007 Wiley‐Liss, Inc.
The synthesis of dopaminergic radioligands labelled with tritium and iodine‐125
Authors: Filer Crist N. 
Published: June 2007

AbstractThe preparation of dopaminergic ligands radiolabelled with either tritium or iodine‐125 has been an extremely important undertaking to advance understanding of this critical receptor class and the topic is reviewed from 1976 through 2006. Although not an exhaustive compilation of references, the cited examples highlight the many methods employed to prepare these useful reagents. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐term effects on the digestive tract of feeding large amounts of resistant starch: A study in pigs
Authors: Martínez‐Puig Daniel , Castillo Marisol , Nofrarias Miquel , Creus Eva , Pérez José F 
Published: June 2007

AbstractThe present study aimed to assess the digestive consequences of the long‐term intake of two starches providing different amounts of resistant starch. Growing pigs were used as the animal model and meal‐fed for 14 weeks on a diet containing a high amount of either raw potato starch (RPS) or corn starch (CS). Digestive adaptation was chronologically evaluated by measuring organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and starch digestibility. After 97 days, whole‐tract digestibility of OM, CP and NDF was lower for RPS‐ compared to CS‐fed pigs, whereas no differences were observed in faecal starch digestibility. In contrast, starch digestibility was reduced in the proximal compartments (ileum, caecum and proximal colon) of animals fed the RPS diet. The concentration of short‐chain fatty acids (SCFAs; P < 0.05), and purine bases (PBs; P < 0.01) was also higher in distal colon and rectum of animals fed the RPS diet. Changes in bacterial community structure (dendogram analyses) were seen in the rectum. Biodiversity tends to increase more in RPS compared to CS fed animals (34.1 vs. 28.8; P = 0.07). Among SCFAs, the proportion of butyrate was two‐fold higher in proximal colon digesta of RPS compared to CS fed pigs (0.20 vs. 0.11; P < 0.05). Increased butyrate formation in the colon reduced the number of apoptosis per crypt in the proximal colonic mucosa (0.38 vs. 0.62; P < 0.05). RPS fermentation reduced indices associated with damage to intestinal epithelial cells, such as crypt cell hyperproliferation and magnesium excretion. Long‐term ingestion of RPS induces pronounced changes of the digestive tract and their microflora, modifying mineral absorption and colonic morphology for which health benefits are likely to be associated. Copyright © 2007 Society of Chemical Industry
The role of mass spectrometry to study the Oklo–Bangombé natural reactors
Authors: De Laeter J.R. , Hidaka H. 
Published: June 2007

AbstractThe discovery of the existence of chain reactions at the Oklo natural reactors in Gabon, Central Africa in 1972 was a triumph for the accuracy of mass spectrometric measurements, in that a 0.5% anomaly in the 235U/238U ratio of certain U ore samples indicated a depletion in 235U. Mass spectrometric techniques thereafter played a dominant role in determining the nuclear parameters of the reactor zones themselves, and in deciphering the geochemical characteristics of various elements in the U‐rich ore and in the surrounding rock strata. The variations in the isotopic composition of a large number of elements, caused by a combination of nuclear fission, neutron capture and radioactive decay, provide a powerful tool for investigating this unique geological environment. Mass spectrometry can be used to measure the present‐day elemental and isotopic abundances of numerous elements, so as to decipher the past history of the reactors and examine the retentivity/mobility of these elements. Many of the fission products have a radioactive decay history that have been used to date the age and duration of the reactor zones, and to provide insight into their nuclear and geochemical behavior as a function of time. The Oklo fission reactors and their near neighbor at Bangombé, some 30 km to the south‐east of Oklo, are unique in that not only did they become critical some 2 × 109 years ago, but also the deposits have been preserved over this period of geological time. The long‐term geochemical behavior of actinides and fission products have been extensively studied by a variety of mass spectrometric techniques over the past 30 years to provide us with significant information on the mobility/retentivity of this material in a natural geological repository. The Oklo–Bangombé natural reactors are therefore geological analogs that can be evaluated in terms of possible radioactive waste containment sites. As more reactor zones were discovered, it was realized that they could be classified into two groups according to their burial depth in the Oklo mine‐site. Reactor Zones 10, 13, and 16 were buried more deeply, and were therefore less weathered than the other zones. The less‐weathered zones are of great importance in mobility/retentivity studies and therefore to the question of radioactive waste containment. Isotopic studies of these natural reactors are also of value in physics to examine possible variations in fundamental constants over the past 2 billion years. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:683–712, 2007
Protein kinase Cε interacts with Stat3 and regulates its activation that is essential for the development of skin cancer
Authors: Aziz Moammir H. , Manoharan Herbert T. , Sand Jordan M. , Verma Ajit K. 
Published: June 2007

AbstractProtein kinase C (PKC) represents a large family of phosphatidylserine (PS)‐dependent serine/threonine protein kinases. At least six PKC isoforms (α, δ, ε, η, µ, and ζ) are expressed in epidermis. PKC is a major intracellular receptor for 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and is also activated by a variety of stress factors including ultraviolet radiation (UVR). PKC isozymes (α, δ, ε, and η), exhibit specificities to the development of skin cancer. PKCε, a calcium‐insensitive PKC isoform, is linked to the development of squamous cell carcinoma (SCC) elicited either by the 7,12‐Dimethylbenzanthracene (DMBA)‐TPA protocol or by repeated exposures to UVR. PKCε overexpressing transgenic mice, when treated either with TPA or exposed to UVR, elicit similar responses such as inhibition of apoptosis, promotion of cell survival, and development of SCC. PKCε overexpression increases Stat3 activation after either TPA treatment or UVR exposure. Both PKCε and signal transducers and activators of transcription‐3 (Stat3) are implicated in the development of SCC. However, the link between PKCε and Stat3 remains elusive. We found that PKCε interacts with Stat3. PKCε interaction with Stat3 was dependent upon UVR treatment. In reciprocal immunoprecipitation/blotting experiments, Stat3 coimmunoprecipitated with PKCε. Colocalization of PKCε with Stat3 was confirmed by double immunofluorescence staining. PKCε interaction with Stat3 was PKCε isoform specific and was not observed with other protein kinases. As observed in vitro with immunocomplex kinase assay with immunopurified PKCε and Stat3, PKCε phosphorylated Stat3 at the serine 727 residue. PKCε depletion prevented Stat3Ser727 phosphorylation, Stat3 DNA binding, and transcriptional activity. The results presented indicate that PKCε mediates Stat3 activation. © 2007 Wiley‐Liss, Inc.
Costly price adjustment and the optimal rate of inflation
Authors: Konieczny Jerzy D. 
Published: June 2007

AbstractI analyse the optimal rate of inflation when prices are costly to change. As the costs of price adjustment are the main friction in the model, effects of inflation stem from the accounting role of money. Inflation increases relative price variability and reduces the average product of labour. This productivity distortion may be offset by a reduction in the desired real price. In general, the optimal rate of inflation is zero. This is consistent with early studies in monetary literature (LeBlanc, 1690, Jevons, 1875, Fisher, 1911 and Marshall, 1923), which concentrated on the role of money as a unit of account and argued that the goal of monetary policy should be price stability. Copyright © 2007 John Wiley & Sons, Ltd.
An implicit unitless error and step‐size control method in integrating unified viscoplastic/creep ODE‐type constitutive equations
Authors: Cao J. , Lin J. , Dean T. A. 
Published: June 2007

AbstractA series of numerical analyses are carried out to investigate the difficulties in numerical integration of unified viscoplastic/creep constitutive equations, which are normally represented as a system of ordinary differential equations (ODEs). The problems of numerically integrating the constitutive equations are identified and analysed. To overcome the stiffness problems, implicit methods are used for the numerical integration and a generic technique is introduced to calculate the Jacobian matrix. A normalization technique is introduced in the paper to convert the integration errors for each time increment to unitless errors. Thus, a single tolerance can be used to control the accuracy and step size in integrating a set of unified viscoplastic/creep constitutive equations. In addition, an implicit
step‐size control method is proposed and used in the integrations. This method reduces the possibility of rejection of an integration increment due to poor accuracy. Copyright © 2007 John Wiley & Sons, Ltd.
Occlusal grooves in anterior dentition among Kovuklukaya inhabitants (Sinop, northern Anatolia, 10th century AD)
Authors: Erdal Y. S. 
Published: June 2007

AbstractMesiodistally directed grooves have been observed on the occlusal surfaces of nine incisors of five females in a small skeletal population from Kovuklukaya (Sinop, northern Anatolia, 10th century AD). There is no archaeological evidence to explain the cultural practices that must have caused such unusual abrasions of the anterior dentition. Investigations of the geographical characteristics of the region and data gathered on the traditional lifestyles of Çulhalı inhabitants enables us to reach meaningful conclusions about the Kovuklukaya people. According to the direction of the grooves, ecological characteristics of the region, and ethnographic data, it is proposed that the unusual abrasion observed in the Kovuklukaya population may be linked to passing yarn between the anterior teeth to wet it. The grooves in the Kovuklukaya population were found only in female skeletons, indicating the existence of a sex‐based division of labour in yarn production. Copyright © 2007 John Wiley & Sons, Ltd.
Blood–retinal barrier disruption and ultrastructural changes in the hypoxic retina in adult rats: the beneficial effect of melatonin administration
Authors: Kaur C , Sivakumar V , Yong Z , Lu J , Foulds WS , Ling EA 
Published: June 2007

AbstractReactive changes in astrocytes and Müller cells in the retina of adult rats subjected to hypoxia were investigated. Along with this, the integrity of the blood–retinal barrier (BRB) was assessed using fluorescent and electron‐dense tracers. In hypoxic rats, mRNA and protein expression of glial fibrillary acidic protein (GFAP) and aquaporin‐4 (AQ4) were significantly increased. AQ4 immunoreactive cells were identified as astrocytes and Müller cells by double immunofluorescence labelling. Another alteration in the hypoxic retina was marked reduction in melatonin content compared to controls. In this connection, administration of exogenous melatonin reduced the tissue concentration of vascular endothelial growth factor (VEGF) and nitric oxide (NO); both were elevated in hypoxic rats. A major structural change in the hypoxic retina was swelling of astrocyte and Müller cell processes but this was noticeably attenuated after melatonin administration. Following an intraperitoneal or intravenous injection of rhodamine isothiocyanate (RhIC) or horseradish peroxidase (HRP), leakage of both tracers was observed in the retina in hypoxic rats but not in the controls, indicating that the functional integrity of the BRB is compromised in hypoxia/reoxygenation. It is suggested that enhanced tissue concentration of VEGF and NO production in the hypoxic retina contribute to increased permeability of the retinal blood vessels. The concurrent up‐regulation of AQ4, a water‐transporting protein, in astrocytes and Müller cells in hypoxia suggests its involvement in oedema formation. Since melatonin effectively reduced the vascular permeability in the retina of hypoxic rats, as evidenced by reduced leakage of RhIC, we suggest that its administration may be of potential benefit in the management of retinal oedema associated with retinal hypoxia. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Treatment of metastatic Ewing sarcoma/primitive neuroectodermal tumor of bone: Evaluation of increasing the dose intensity of chemotherapy—a report from the Children's Oncology Group
Authors: Miser James S. , Goldsby Robert E. , Chen Zhengjia , Krailo Mark D. , Tarbell Nancy J. , Link Michael P. , Fryer Christopher J.H. , Pritchard Douglas J. , Gebhardt Mark C. , Dickman Paul S. , Perlman Elizabeth J. , Meyers Paul A. , Donaldson Sarah S. , Moore Sheila G. , Rausen Aaron R. , Vietti Teresa J. , Grier Holcombe E. 
Published: June 2007

AbstractBackgroundThe outcome for patients with Ewing sarcoma family of tumors (ESFTs) of bone with metastases at diagnosis remains poor despite new approaches to treatment. We evaluated whether a dose‐intensity chemotherapy regimen improved survival for patients with ESFTs of bone with metastases at diagnosis.MethodsWe entered 60 patients with metastatic ESFTs of bone onto a single arm trial of a new intensive therapy. Treatment consisted of 51‐weeks of chemotherapy and local control of the primary with radiation, surgery, or both. The chemotherapeutic protocol included two alternating blocks: one with vincristine (2 mg/m2), doxorubicin (90 mg/m2), and cyclophosphamide (2,200 mg/m2); and the second with ifosfamide (2,800 mg/m2/day × 5 days) and etoposide (100 mg/m2/day × 5 days).ResultsOf the 60 patients with metastatic ESFTs of bone enrolled onto this single arm trial, 12 had metastasis to lung only, 7 to bone marrow or bone only, 38 to multiple sites, 2 in other sites and 3 not specified. There were three toxic deaths. Six patients (6‐year cumulative incidence: 9%) developed second malignant neoplasms and died. The 6‐year overall event‐free survival (EFS) was 28% (standard error (SE) 6%) and survival (S) was 29% (SE 6%).ConclusionAn intensified treatment regimen using higher doses of cyclophosphamide, ifosfamide, and doxorubicin increased toxicity and risk of second malignancy without improving EFS and S. Pediatr Blood Cancer 2007;49:894–900. © 2007 Wiley‐Liss, Inc.
Synthesis of stable “gold nanoparticle–polymeric micelle” conjugates: A new class of star “molecular chimera” that self‐assemble into linear arrays of spherical micelles
Authors: Abraham Sinoj , Ha Chang‐Sik , Batt Carl A. , Kim Il 
Published: June 2007

AbstractStable and aggregation‐free “gold nanoparticle–polymeric micelle” conjugates were prepared using a new and simple protocol enabled by the hydrogen bonding between surface‐capping ligands and polymeric micelles. Individual gold nanoparticles were initially capped using a phosphatidylthio–ethanol lipid and further conjugated with a star poly(styrene‐block‐glutamic acid) copolymer micelle using a one‐pot preparation method. The morphology and stability of these gold–polymer conjugates were characterized using transmission electron microscopy (TEM) and UV–vis spectroscopy. The self‐assembly of this class of polymer‐b‐polypeptide in aqueous an medium to form spherical micelles and further their intermicelle reorganization to form necklace‐like chains was also investigated. TEM and laser light scattering techniques were employed to study the morphology and size of these micelles. Polymeric micelles were formed with diameters in the range of 65–75 nm, and supermicellular patterns were observed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3570–3579, 2007
Polymerization of 1‐olefins by zirconium/titanium precatalysts with O,N,O‐ligating atoms—can aggregation of catalyst be inferred from the reaction profile?
Authors: Keren Everta , Sundararajan Govindarajan 
Published: June 2007

AbstractThe 2‐[benzyl‐(2‐hydroxy‐2‐phenylethyl)‐amino]‐1‐phenylethanol ligand (1‐H2) prepared as a diastereomeric mixture or in racemic and meso forms, from known procedure, has been disodiated and complexed with ZrCl4. The precatalysts (mix‐1‐ZrCl2, rac‐1‐ZrCl2, and meso‐1‐ZrCl2) were used in combination with methylaluminoxane and found to be active for the polymerization of 1‐hexene and 1‐octene. The high molecular weight polyhexenes (PHs) and polyoctenes (POs) thus obtained were isotactic in nature and showed a negligible amount of end groups arising from the chain termination reactions. In PHs and POs, there was linear correlation in the modified Arrhenius plot (the natural logarithm of the number‐average molecular weight vs. the reciprocal of the temperature), indicating the presence of a single active species. The enantiomerically pure titanium precatalyst ((R,R)‐1‐TiCl2), when employed for the polymerization of 1‐hexene, was found to be active and the modified Arrhenius plot showed linear dependence demonstrating presence of a single active species. The analogous titanium precatalysts (mix‐1‐TiCl2, rac‐1‐TiCl2, and meso‐1‐TiCl2) obtained from known procedures were also found to be active for the polymerization of 1‐octene. The rac‐1‐TiCl2 precatalyst demonstrated a sigmoidal behavior in the modified Arrhenius plot for the POs and the mix‐1‐TiCl2 precatalyst showed an exponential type of behavior. The obtained POs seemed to have small amounts of chain termination via β‐hydride elimination alone. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3599–3610, 2007