bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydroxylation of dental zirconia surfaces: Characterization and bonding potential
Authors: Lohbauer Ulrich , Zipperle Marita , Rischka Klaus , Petschelt Anselm , Müller Frank A 
Published: May 2008

AbstractBioinert zirconia surfaces exhibit a low chemical bonding potential to resin‐based luting agents. The aim was to hydroxylate dental zirconia surfaces and to examine tensile bond strength using commercial luting agents. The measured bond strength was compared with established mechanical conditioning techniques. Five acidic and one alkaline hydroxylation pretreatments were applied and compared with air abrasion and tribochemical silica coating. For the chemical characterization of hydroxyl groups and hydroxyl value, zirconia powders were used, chemically modified, and analyzed using Fourier‐transformed infrared spectroscopy and a titrimetric method according to the ISO 4629 standard. All acidic pretreatment procedures exhibited increased hydroxyl values. The highest values were recorded after treatment with phosphoric acid or Piranha solution. Tensile bond strength was examined in a universal testing machine using the commercial dual‐cure luting agents Multilink (Ivoclar, Liechtenstein) and Panavia F2.0 (Kuraray, Japan). Surface hydroxylation with Piranha solution in combination with the luting agent Multilink led to a bond strength of 12.47 ± 3.25 MPa. Tribochemical silica‐coated/silanized zirconia surfaces with Multilink produced the highest bond strength of 19.33 ± 3.65 MPa. Using the luting agent Panavia F2.0, statistically homogenous values for the untreated (11.60 ± 1.68 MPa) and for the hydroxylated surface (12.46 ± 3,81 MPa) were measured. Bioinert zirconia surfaces were successfully hydroxylated in terms of tensile bond strength. Resin bonding with Multilink can be strongly increased by acidic treatment with Piranha solution. Bonding with Panavia F2.0 is not affected by hydroxylation, which is likely due to the incorporation of specific functional monomers. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Interfacial morphology and bond strength of self‐etching adhesives to primary dentin with or without acid etching
Authors: Bolaños‐Carmona Victoria , González‐López Santiago , De Haro‐Muñoz Cristina , Briones‐Luján María T. 
Published: May 2008

AbstractThe aim of the study was to determine the interfacial morphology and bond strength of three current self‐etching adhesives (SEAs) to primary dentin and to evaluate the effect of introducing an additional step of phosphoric acid etching. Three human primary molars were assigned to each adhesive group for testing microtensile bond strength (μTBS) and three for studying interface morphology. Groups were: group 1, Excite, a total‐etch adhesive (control); group 2, Adhese (ASE); group 3, Adper‐Prompt‐L‐Pop (APLP), and group 4: Xeno III (XE) SEAs; groups 5–7 received application of 37% phosphoric acid for 15 s before applying ASE, APLP, and XE, respectively. A class I cavity was performed in each molar to study the interface morphology. Two halves of each tooth were used for examination either by optical microscopy, using Masson's trichromic dye technique, or by scanning electron microscopy. For μTBS determination, composite/dentin bars (1 mm2 section) were obtained from each tooth, and tested in tension until debonding. The μTBS was significantly lower in the APLP than in the rest of the groups. The performance of SEAs on primary dentin depends on the product. Inclusion of dentin pre‐etching step did not significantly modify μTBS results. All SAEs achieved greater decalcification depth on etched versus nonetched dentin. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Initiation of caspase‐independent death in mouse mesangial cells by Cd2+: Involvement of p38 kinase and CaMK‐II
Authors: Liu Ying , Templeton Douglas M. 
Published: May 2008

AbstractCadmium (Cd) is a toxic metal with multiple effects on cell signaling and cell death. We studied the effects of Cd2+ on quiescent mouse mesangial cells in serum‐free conditions. Cadmium induces cell death over 6 h through annexin V+ states without or with causing uptake of propidium iodide, termed apoptotic and apoptosis‐like death, respectively. Little or no necrosis is observed, and cell death is caspase‐independent and associated with nuclear translocation of the apoptosis‐inducing factor, AIF. We previously showed that Cd2+ increased phosphorylation of Erk and CaMK‐II, and CaMK‐II activation increased cell death in an Erk‐independent manner. Here we demonstrate that Cd2+ increases Jnk and p38 kinase phosphorylation, and inhibition of p38—but not of Jnk—increases cell viability by suppressing apoptosis in preference to apoptosis‐like death. Neither p38 kinase nor CaMK‐II inhibition protects against a decrease in mitochondrial membrane potential, ψ, indicating that kinase‐mediated death is either independent of, or involves events downstream of a mitochondrial pathway. However, both the antioxidant N‐acetyl cysteine (NAC) and the mitochondrial membrane‐stabilizing agent cyclosporine A (CsA) partially preserve ψ, suppress activation of p38 kinase, and partially protect the cells from Cd2+‐induced death. Whereas the effect of CsA is on apoptosis, NAC acts on apoptosis‐like death. Inhibition of glutathione synthesis exacerbates a Cd2+‐dependent increase in cellular peroxides and favors apoptosis‐like death over apoptosis. The caspase‐independence of these modes of cell death is not due to an absence of this machinery in the mesangial cells: when they are exposed to Cd2+ for longer periods in the presence of serum, procaspase‐3 and PARP are cleaved and caspase inhibition is protective. We conclude that Cd2+ can kill mesangial cells by multiple pathways, including caspase‐dependent and ‐independent apoptotic and apoptosis‐like death. Necrosis is not prominent. Activation of p38 kinase and of CaMK‐II by Cd2+ are associated with caspase‐independent apoptosis that is not dependent on mitochondrial destabilization. J. Cell. Physiol. 217: 307–318, 2008. © 2008 Wiley‐Liss, Inc.
Stem cell antigen‐1 localizes to lipid microdomains and associates with insulin degrading enzyme in skeletal myoblasts
Authors: Epting Conrad L. , King Frank W. , Pedersen Anissa , Zaman Jessica , Ritner Carissa , Bernstein Harold S. 
Published: May 2008

AbstractStem cell antigen‐1 (Sca‐1, Ly6A/E) is a glycosylphosphotidylinositol‐anchored protein that identifies many tissue progenitor cells. We originally identified Sca‐1 as a marker of myogenic precursor cells and subsequently demonstrated that Sca‐1 regulates proliferation of activated myoblasts, suggesting an important role for Sca‐1 in skeletal muscle homeostasis. Beyond its functional role in regulating proliferation, however, little is known about the mechanism(s) that drive Sca‐1‐mediated events. We now report that lipid microdomain organization is essential for normal myogenic differentiation, and that Sca‐1 constitutively localizes to these domains during myoblast proliferation and differentiation. We also demonstrate that Sca‐1 associates with insulin degrading enzyme (IDE), a catalytic protein responsible for the cleavage of mitogenic peptides, in differentiating myoblasts. We show that chemical inhibition of IDE as well as RNAi knockdown of IDE mRNA recapitulates the phenotype of Sca‐1 interference, that is, sustained myoblast proliferation and delayed myogenic differentiation. These findings identify the first signaling protein that physically and functionally associates with Sca‐1 in myogenic precursor cells, and suggest a potential pathway for Sca‐1‐mediated signaling. Future efforts to manipulate this pathway may lead to new strategies for augmenting the myogenic proliferative response, and ultimately muscle repair. J. Cell. Physiol. 217: 250–260, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis of [18F]fluoroacetaldehyde. Application to [18F]fluoroethylation of benzylamine under reductive alkylation conditions
Authors: Prenant C. , Gillies J. , Bailey J. , Chimon G. , Smith N. , Jayson G. C. , Zweit J. 
Published: May 2008

AbstractThe radiosynthesis of a new [18F]fluoroalkylating agent, [18F]fluoroacetaldehyde, is described. It was produced using the Kornblum method by oxidation with dimethyl sulphoxide of 2‐[18F]fluoroethyl p‐toluenesulphonate ([18F]FETos). In these conditions the oxidation proceeds smoothly and rapidly to the selective conversion of tosyl esters of primary alcohols to aldehydes with no carboxylic acids being produced. The chemical identity of [18F]fluoroacetaldehyde was determined by comparing its chromatographic properties as well as those of its 2,4‐dinitrophenylhydrazone (2,4‐DNPH) derivative with those of, respectively, the standard fluoroacetaldehyde and its 2,4‐DNPH derivative. Standard fluoroacetaldehyde was prepared by oxidation of fluoroethanol with pyridinium dichromate and characterized as its 2,4‐DNPH derivative by mass spectrometry. To test its reactivity with amines under reductive alkylation conditions, [18F]fluoroacetaldehyde was reacted with benzylamine used as model substrate. The chemical identity of the resulting radiolabelled product was determined to be [18F]N‐(2‐fluoroethyl)‐benzylamine by comparing its chromatographic properties with those of the synthesized standard N‐(2‐fluoroethyl)‐benzylamine characterized by 19F and 1H NMR spectroscopy and mass spectrometry. This new fluorine‐18 labelled synthon may find applications in radiolabelling peptide, protein and antibody fragments as well as in aldol condensation or in the Mannich reaction. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of [2H, 13C] and [14C] labeled vasopressin V1a/V2 receptor antagonist RWJ‐676070 and its stable labeled N‐des‐benzoyl metabolite
Authors: Gong Yong , Hoerr David C. , Weaner Larry E. , Lin Ronghui 
Published: May 2008

AbstractStable isotope‐labeled ([13C2, D3]) and carbon 14‐labeled vasopressin receptor antagonist RWJ‐676070, a spirobenzazepine amide, were prepared in separate syntheses for use in drug metabolism studies. The stable isotopically labeled sample was prepared starting from [13C2, D6]dimethyl sulfate and [13C]copper (I) cyanide in nine steps with a 14% overall isotopic yield. The 14C label was introduced in five steps starting from [14C]potassium cyanide to provide material having a specific activity of 58 mCi/mmol (2.15 GBq/mmol). Selective hydrolysis of the metabolically labile amide bond in [13C2, D3]RWJ‐676070 gave the corresponding labeled metabolite in one step. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of11C‐labelled metomidate analogues as adrenocortical imaging agents
Authors: Karimi Farhad , Erlandsson Maria , Lindhe Örjan , Långström Bengt 
Published: May 2008

AbstractClinical findings using [11C]methyl 1‐[(1R)‐1‐phenylethyl]‐1H‐imidazole‐5‐carboxylate ([11C]MTO, 1) show high uptake in lesions of adrenocortical origin, including adenomas, but low uptake in lesions of non‐adrenocortical origin. In this paper the synthesis and preclinical evaluation of two new11C‐labelled analogues of MTO, [11C]methyl 1‐[(1R)‐1‐(4‐chlorophenyl)ethyl]‐1H‐imidazole‐5‐carboxylate ([11C]CLM, 2) and [11C]methyl 1‐[(1R)‐1‐(4‐bromophenyl)ethyl]‐1H‐imidazole‐5‐carboxylate ([11C]BRM, 3), using frozen‐section autoradiography, organ distribution and a metabolic study are presented. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and in vitro evaluation of 18F‐β‐carboline alkaloids as PET ligands
Authors: Blom Elisabeth , Karimi Farhad , Eriksson Olof , Hall Håkan , Långström Bengt 
Published: May 2008

AbstractA one‐step 18F‐labelling strategy was used to prepare four 18F‐labelled analogues of 7‐methoxy‐1‐methyl‐9H‐β‐carboline (harmine): 7‐(2‐[18F]fluoroethoxy)‐1‐methyl‐9H‐β‐carboline (5), 7‐(3‐[18F]fluoro‐propoxy)‐1‐methyl‐9H‐β‐carboline (6), 7‐[2‐(2‐[18F]fluoroethoxy)ethoxy]‐1‐methyl‐9H‐β‐carboline (7), and 7‐{2‐[2‐(2‐[18F]fluoroethoxy)ethoxy]‐ethoxy}‐1‐methyl‐9H‐β‐carboline (8). These were synthesized as potential positron emission tomography ligands for monoamine oxidase A (MAO‐A). A solution of pure labelled compound in buffer was obtained in <70 min from end of radionuclide production, with a decay‐corrected yield of up to 23%. The average specific binding to MAO‐A in rat brain, determined by autoradiography experiments, was highest for compounds 7 and 8 (89±2 and 96±1%, respectively), which was obtained at <1 nM radioligand concentration. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation of double‐stranded DNA/drug interaction by ESI/FT ICR: orientation of dissociations relates to stabilizing salt bridges
Authors: Xu Ying , Afonso Carlos , Wen Ren , Tabet Jean‐Claude 
Published: June 2008

AbstractNoncovalent complexes of DNA and Hoechst 33258 were investigated by ESI–FT/ICR MS in various activation modes (collision‐induced dissociation (CID), sustained off‐resonance irradiation collision‐induced dissociation (SORI–CID), infrared multiphoton dissociation (IRMPD) and electron detachment dissociation (EDD)). The binding selectivity of Hoechst 33258 was confirmed by the comparative study of its noncovalent association with different DNA sequences. The CID spectra of [ds + HO − 5H]5− obtained with a linear hexapole ion trap resulted in unzipping of the strands. This outcome is a clue to the drug‐binding mode, shading light on the localization of the binding sites of Hoechst 33258 to the DNA sequence. The IRMPD and SORI–CID experiments mainly gave DNA backbone cleavages and internal fragment ions. From this result, information on the localization of the binding sites of Hoechst 33258 in the DNA sequence was obtained. No sodium cationization was observed on the DNA sequence ions although they were present on fragmentation of the duplex, indicating that the backbone cleavages were generated from the single strand associated with the Hoechst 33258 where the number of alkali cation is restricted. Under electron detachment (ED) conditions, multiple EDs were achieved for the [ds + HO − 5H]5− ion without any significant dissociation. The presence of drug appears to enhance the stability of the multiply charged system. It was proposed that the studied noncovalent complex involved the formation of zwitterions and consequently strong salt‐bridge interactions between DNA and drug. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectrometry of selective androgen receptor modulators
Authors: Thevis Mario , Schänzer Wilhelm 
Published: June 2008

AbstractNonsteroidal selective androgen receptor modulators (SARMs) are an emerging class of drugs for treatment of various diseases including osteoporosis and muscle wasting as well as the correction of age‐related functional decline such as muscle strength and power. Several SARMs, which have advanced to preclinical and clinical trials, are composed of diverse chemical structures including arylpropionamide‐, bicyclic hydantoin‐, quinoline‐, and tetrahydroquinoline‐derived nuclei. Since January 2008, SARMs have been categorized as anabolic agents and prohibited by the World Anti‐Doping Agency (WADA). Suitable detection methods for these low‐molecular weight drugs were based on mass spectrometric approaches, which necessitated the elucidation of dissociation pathways in order to characterize and identify the target analytes in doping control samples as well as potential metabolic products and synthetic analogs. Fragmentation patterns of representatives of each category of SARMs after electrospray ionization (ESI) and collision‐induced dissociation (CID) as well as electron ionization (EI) are summarized. The complexity and structural heterogeneity of these drugs is a daunting challenge for detection methods. Copyright © 2008 John Wiley & Sons, Ltd.
Gene expression patterns in mouse cortical penumbra after focal ischemic brain injury and reperfusion
Authors: Sarabi Arezou S. , Shen Hui , Wang Yun , Hoffer Barry J. , Bäckman Cristina M. 
Published: May 2008

AbstractIschemic stress in the brain causes acute and massive cell death in the targeted core area followed by a second phase of damage in the neighboring penumbra. The purpose of this study was to examine the global gene expression patterns in the penumbra, because the ischemic lesion in this region could be rescued by restoration of blood flow and other protective therapies. Adult C57Bl/6 mice were subjected to a 90‐min middle cerebral artery occlusion (MCAO). Laser capture microdissection (LCM) was used for tissue dissection at 4 and 24 hr after reperfusion. Sham‐operated animals were used as controls. Gene expression in the penumbra was examined by using microarray analysis and quantitative RT‐PCR. In agreement with previous reports, most genes were down‐regulated at 4 hr after the onset of reperfusion in the ischemic penumbra compared with controls. In contrast, at 24 hr after reperfusion, most genes were up‐regulated in the ischemic penumbra. Several genes not previously reported to be associated with ischemia were found. The gene lists generated in this study will help us to understand better the spatial and temporal distribution of molecules involved in the ischemic cascade. Published 2008 Wiley‐Liss, Inc.
Nucleotide sequence of plasmid pA387 of Amycolatopsis benzoatilytica and construction of a conjugative shuttle vector
Authors: Malhotra Shweta , Majumdar Swati , Kumar Mukesh , Bhasin V. K. , Gartemann Karl‐Heinz , Lal Rup 
Published: May 2008

AbstractThe complete nucleotide sequence of plasmid pA387 of Amycolatopsis benzoatilytica DSM 43387 was determined. Sequence analysis revealed that pA387 is 30,157 bp long and has a G+C content of 71.74%. To obtain a minimal transferable replicon capable of self‐replication, a 2,176 bp fragment of pA387 was cloned, and we demonstrated that this fragment is sufficient for autonomous replication. The replication region of pA387 exhibited no significant homology to any known replication proteins available in databases. Putative maintenance and transfer functions were identified on pA387. The predicted products of open reading frames, ORF 2 and ORF 12, resembled the plasmid stabilizing proteins, a DNA resolvase and a ParA protein, respectively. The putative translational products of ORF 15 and ORF 16 showed similarity to known bacterial conjugation proteins, TraG and TraA, respectively. A conjugative Escherichia coli ‐Amycolatopsis shuttle‐cloning vector was constructed by using the pA387 replicon and designated pSETRL1. Shuttle vector pSETRL1 successfully transformed Amycolatopsis mediterranei DSM 40773 and Amycolatopsis orientalis NBRC 12806 by conjugation and electroporation, and is likely to be a useful vector in Amycolatopsis research. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification and antioxidant activity of melanin isolated from Hypoxylon archeri, a companion fungus of Tremella fuciformis
Authors: Wu Yao , Shan Linjun , Yang Shuangxi , Ma Aimin 
Published: May 2008

AbstractMelanin produced by Hypoxylon archeri, a companion fungus of Tremella fuciformis, was purified from the submerged culture medium and designated as HM. Ultraviolet‐visible and FTIR spectra of the purified HM showed significant similarities with those of the synthesized melanin derived from tyrosine. Thus, the HM melanin was identified to be derived from the precursor molecule of tyrosine or dihydroxyphenylalanine (DOPA).The antioxidant activity of HM melanin, synthetic melanin and vitamin C were compared by inhibition of the oxidation of 5‐thio‐2‐nitrobenzoic acid (TNB) caused by hypochlorous acid (HOCl) and hydrogen peroxide (H2O2). The HM melanin is likely to be more efficient eliminating oxygen free radicals generated by H2O2 than by HOCl. At a concentration of 100 mg · l–1, the HM melanin protected 80.95% of TNB oxidation by H2O2, slightly higher than the synthetic melanin. Inhibition curves as a function of time also revealed the HM melanin was a more effcient inhibitor of H2O2 oxidation with an average TNB (TNBacr) consumption rate of 0.0553 mmol l–1 · min–1 during the inhibition phase. Therefore, HM melanin is an efficient scavenger of peroxide free radicals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physical activity levels after limb salvage surgery are not related to clinical scores—objective activity assessment in 22 patients after malignant bone tumor treatment with modular prostheses
Authors: Rosenbaum D. , Brandes M. , Hardes J. , Gosheger G. , Rödl R. 
Published: June 2008

AbstractBackgroundThe aim of the present study was to objectively assess the physical activity levels of patients after tumor prosthesis implantation with two objective measurement devices.MethodsThe DynaPort ADL monitor permitted up to 24 hr monitoring of lower‐extremity physical activities in daily life with respect to posture and locomotion. The step activity monitor (SAM) was worn for a whole week to collect the daily number of gait cycles. The devices were worn during the waking hours by 22 patients with knee prostheses after wide tumor resection.ResultsIn the MSTS and TESS scores the patients achieved over 80% of the maximum score indicating a good clinical outcome. The most prominent activity was sitting which accounted for 54 ± 18% of the recorded time, followed by standing (27 ± 16%), locomotion (10 ± 6%), and lying (8 ± 6%). During locomotion, the average walking activity accumulated to 4,786 ± 1,770 step cycles per day (range 2,045–8,135) corresponding to a yearly 1.75 million steps. There was no significant correlation between clinical scores and step count measures.ConclusionsEven though this activity level was lower than for a group of healthy adults it was comparable to the activity level for other patients, for example, with hip arthroplasty as reported in the literature. J. Surg. Oncol. 2008;98:97–100. © 2008 Wiley‐Liss, Inc.
Estimation of the fiber temperature during an arc‐discharge
Authors: Rego Gaspar , Santos Luís M. N. B. F. , Schröder Bernd 
Published: May 2008

AbstractThe formation mechanisms and properties of arc‐induced gratings are intrinsically related to the temperature attained by the fiber during arc exposure. In this work, we present further results on the estimation of the fiber temperature based on the use of electrically insulated thermocouples. Computer simulations show that under typical arc discharge conditions, the fiber reaches steady‐state thermal equilibrium in less than half a second, having a peak temperature of about 1350°C. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2020–2025, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23555
Miniaturized rectangular cavity resonator based on anisotropic metamaterials bilayer
Authors: Meng Fan‐Yi , Wu Qun , Fu Jia‐Hui 
Published: May 2008

AbstractIn this letter, resonance properties of a miniaturized rectangular cavity resonator (MRCR) based on anisotropic metamaterials bilayer are investigated. The resonance equations for the electromagnetic wave in a rectangular cavity filled with anisotropic metamaterials bilayer are solved and analyzed first. It is shown that, different from the isotropic case and the one‐dimension (1D) resonator, the resonance properties of such a cavity are closely related to the dispersion relation of the anisotropic medium, which brings more design flexibility and tolerance for miniaturizing a conventional rectangular cavity resonator. As an example, a MRCR loaded only with negative permeability medium is designed and numerically simulated. It is shown that the resonant behavior is successfully observed, and the width and length of the MRCR are simultaneously shortened by 70%, compared with a conventional rectangular cavity resonator dimension. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2016–2020, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23556