bluuebunny/crossref_metadata_2025 huggingface dataset:
Blocking Effect in High Purity Nanostructured Cubic Zirconia Ceramics
Authors: Boulfrad S. , Djurado E. , Dessemond L.
Published: June 2008

Electrical properties of grain boundaries, free of any secondary phases, have been investigated in cubic nanostructured zirconia ceramics. Pure 8YSZ powders were synthesised by spray pyrolysis process. These powders were used to perform dense nanostructured ceramics using two compaction techniques: cold isostatic pressing (CIP) and hot uniaxial pressing (HUP) in an oxidising atmosphere. Grain sizes ranging from 25 to 242 nm and relative densities from 93 up to 98% were obtained. Electrical contribution of the bulk and the blocking effect due to grain boundaries were determined by impedance spectroscopy and analysed according to the brick layer model. The additional blocking effect is a decreasing function of the grain size but its magnitude reaches a plateau quite insensitive to the grain size below 100 nm. This indicates that the recorded electrical contribution originates from an intrinsic effect. This can be related to a dominant electrical contribution of space charge layers located at the grain boundaries area of nanoscale grain sizes.
A fragile site within the HPC1 region at 1q25.3 affecting RGS16, RGSL1, and RGSL2 in human breast carcinomas
Authors: Wiechec Emilia , Overgaard Jens , Hansen Lise Lotte
Published: June 2008

Genomic alterations affecting chromosome arm 1q are considered to be an early event in breast carcinogenesis and are correlated with good prognosis for the patients. In the search for new breast cancer susceptibility genes, we focused on three genes from the Regulator of G protein Signaling family clustered on 1q25.3 within the HPC1 region. RGS16, RGSL2, and RGSL1 encode proteins interacting with G proteins and accelerating termination of the G protein signaling. To evaluate the implication of these genes in somatic breast cancer, we analyzed a 154‐kb segment at 1q25.3 using allelic imbalance (AI) mapping. A panel of 222 patients diagnosed with primary breast cancer was analyzed using newly identified, intragenic short tandem repeats (STRs). A high rate of AI (>50%) was found across the region and led to the identification of internal chromosomal breakpoints. A detailed mapping of the breakpoints revealed intragenic microdeletions affecting the coding regions of RGSL2, RGSL1, and the regulatory region of RGS16. The promoter region of RGS16 was found to be methylated in 10% of the tumors. A decrease in the RGS16 expression was found in tumors with chromosomal breakpoints, AI, and aberrant methylation. We found a significant association between AI of RGSL2 and localized disease, which correlated with good prognosis for patients with breast cancer. In conclusion, we found the 1q25.3 region to be highly unstable in breast tumors comprising a cluster of chromosomal breakpoints, intragenic microdeletions, frequent allelic imbalance correlating with long metastasis‐free survival, and RGS16 promoter methylation affecting the protein expression. © 2008 Wiley‐Liss, Inc.
The first functional study of MLH3 mutations found in cancer patients
Authors: Korhonen Mari K. , Vuorenmaa Elina , Nyström Minna
Published: June 2008

The MLH3 gene is one of the five mismatch repair (MMR) genes associated with hereditary nonpolyposis colorectal cancer (HNPCC). Eighteen different inherited MLH3 mutations have been reported as pathogenic in an international mutation database. In several cases, a mutation was found in a patient without a family history suggestive of inherited cancer susceptibility. In some cases, a similar mutation was also found in sporadic patients and/or healthy controls. Four patients carried an MLH3 mutation together with another inherited MMR gene variation. No functional analyses have been performed to assess the pathogenicity of these 18 mutations. MLH3 has been assumed to be less important in MMR than the other HNPCC susceptibility genes MSH2, MSH6, MLH1, and PMS2, and accordingly a low‐risk gene for colorectal cancer (CRC). To assess the significance of the inherited sequence variations in MLH3, we functionally characterized seven missense mutations (Q24E, R647C, S817G, G933C, W1276R, A1394T, E1451K) scattered throughout the MLH3 polypeptide. The mutations were found in CRC or endometrial cancer patients and reported as pathogenic. Our study showed that the seven mutated MLH3 proteins, in complex with their counterpart MLH1 (MutLγ), repaired mismatches as the wild type MutLγ but worse than a heterodimer of MLH1 and PMS2 (MutLα). The results confirm that MutLγ is a less efficient MMR complex than MutLα and show that the MLH3 mutations alone do not interfere with MMR. Further studies are needed to evaluate the pathogenicity of MLH3 mutations in compound with other MMR mutations. © 2008 Wiley‐Liss, Inc.
Shallow Tunnelling in Soft Ground – Influence of the Chosen Support System on the System Behaviour
Authors: Krenn Florian , Galler Robert , Junker Arne , Stacherl Bernhard
Published: June 2008

The Brenner corridor is part of the new North‐South European rail link for high‐speed trains and combined transport services connecting Munich in Germany and Verona in Italy. As the Lower Inn Valley in Austria is narrow and densely populated with towns lined up along the Inn river, the characteristics of the alignment of the new route is that 83 % of the 41 km long Unterinntal route will run underground. The new route includes the tunnel Vomp‐Terfens which is about 8 km long and is constructed through different types of ground – competent rock and soft ground (quaternary sediments such as ground moraine and gravel). The applied support measures varied from 150 mm steelfibre reinforced shotcrete in the hard rock sections (dolomite) to 300 mm reinforced shotcrete lining with advance support consisting of double layered pipe roof umbrella in the sections with low overburden and layers of potentially unstable gravel.

Two advance support systems were used in similar ground conditions – forepoling with spiles and a pipe roof umbrella support. This paper deals with conclusions drawn from the monitoring results in the tunnel, on the surface and from the evaluation of a horizontal inclinometer which was installed in one of the pipe roofs. The main objective pursued by the authors is the comparison of the mode of loading and its effect on the overall system behaviour, not an evaluation of the “advantages” or “disadvantages” of the two different types of advance support systems. In the authors' opinion there are always “two plus” possibilities to solve a tunnelling task – the chosen solution depends on a variety of factors such as the given geotechnical boundary conditions, the adopted safety level and economic considerations.
Hydrologic history of the Mississippi and Lower Missouri Rivers based upon a refined specific‐gauge approach
Authors: Jemberie Abebe A. , Pinter Nicholas , Remo Jonathan W. F.
Published: May 2008

A refined specific‐gauge approach was developed to quantify changes over time in hydrological response on 3260 km of the Mississippi River system using long‐term data observed at 67 hydrologic measurement stations. Of these stations, 49 were unrated (stage‐only) stations, for which over 2 000 000 ‘synthetic discharges’ were generated based on measured discharge values at nearby rated stations. The addition of these synthetic discharges nearly tripled the number of stations in the study area for which specific‐gauge analysis could be performed. In order to maintain spatial homogeneity across such a broad study area, discharges were normalized to multiples of mean daily flow (MDF). Specific‐gauge analysis calculates stage changes over time for invariant discharge conditions. Two discharges were analysed: low‐flow and flood conditions at each station. In order to avoid the large errors associated with extrapolation of annual rating curves, a new ‘enhanced interpolation’ technique was developed that calculates continuous specific‐stage time series, even for rare discharges. Thus enhanced, specific‐gauge analysis is a useful reconnaissance tool for detecting geomorphic and hydrologic trends over time. Results show that on the Middle Mississippi River and Lower Missouri River, flood stages increased at all stations in spite of widespread incision of the river bed. On the Lower Mississippi River, both low‐flow and flood stages decreased, mainly the result of artificial meander cutoffs in the late 1920s and 1930s, except downstream of Natchez, MS, where net aggradation was observed. On the Upper Mississippi River, the specific‐gauge trends were dominated by emplacement of navigational dams and impoundment of slackwater pools. On all four river reaches, these results document hydrologic responses to the different engineering toolkits used on the different portions of the Mississippi River system during the past 75–150 years. Copyright © 2008 John Wiley & Sons, Ltd.
Hypoxia‐inducible factor 1 and cancer pathogenesis
Authors: Semenza Gregg L.
Published: May 2008

Hypoxia‐inducible factor 1 (HIF‐1) is a transcriptional activator that mediates adaptive responses to hypoxia. HIF‐1 activity is increased in the majority of human cancers as a result of genetic alterations and intratumoral hypoxia. HIF‐1 activates the transcription of genes that increase O2 availability by stimulating angiogenesis or that reprogram cellular metabolism to adapt to reduced O2 availability. Proof of principle studies in mouse models suggests that inhibition of HIF‐1 activity may have therapeutic effects, especially in combination with other anticancer drugs. © 2008 IUBMB IUBMB Life, 60(9): 591–597, 2008
Metabolic regulation by lactate
Authors: Sola‐Penna Mauro
Published: May 2008

For more than a century, the metabolic role of lactate has intrigued physiologists and biochemists. Yet, for the first half of the last century lactate had been designated as a waste product, and assigned no additional significance besides its controversial role in muscle fatigue. The decline of the lactate hypothesis for the onset of muscle fatigue and the defining of some modulatory properties attributed to lactate have increased the interest on this molecule. The present critical review aimed at evaluating some recent publications concerned with unveiling the regulatory actions of lactate in cellular function. Lactate has been described to modulate enzymes catalytic properties to affect hormonal release and responsiveness, and to control body homeostasis. Moreover, these properties are directly related to the genesis and the sustainability of pathological conditions, such as diabetes and cancer. In the end, we concluded that lactate should not be regarded as simply an anaerobic metabolite, but should be considered as a regulatory molecule that modulates the integration of metabolism. © 2008 IUBMB IUBMB Life, 60(9): 605–608, 2008
The estimation of utility‐consistent labor supply models by means of simulated scores
Authors: Bloemen Hans G. , Kapteyn Arie
Published: June 2008

We consider a utility‐consistent static labor supply model with flexible preferences and a nonlinear and possibly non‐convex budget set. Stochastic error terms are introduced to represent optimization and reporting errors, stochastic preferences, and heterogeneity in wages. Coherency conditions on the parameters and the support of error distributions are imposed for all observations. The complexity of the model makes it impossible to write down the probability of participation. Hence we use simulation techniques in the estimation. We compare our approach with various simpler alternatives proposed in the literature. Both in Monte Carlo experiments and for real data the various estimation methods yield very different results. Copyright © 2008 John Wiley & Sons, Ltd.
Biocompatibility of total joint replacements: A review
Authors: Goodman Stuart B. , Gómez Barrena Enrique , Takagi Michiaki , Konttinen Yrjo T.
Published: May 2008

Total joint replacement is one of the most clinically successful, cost‐effective surgical procedures. These operations have been shown to improve pain, function and mobility in patients with end‐stage arthritis. However, joint replacements that will allow full, unrestricted, high impact activities and last the patient's lifetime have not yet been devised. This is due to biocompatibility issues related to material science, biomechanics, and host responses. In this review, three issues that are highly pertinent to biocompatibility of joint replacements are examined. These topics include how implants initially osseointegrate within bone, potential adverse effects of byproducts of wear that can lead to aseptic loosening and perprosthetic osteolysis, and the potential for new bearing surfaces to extend the lifetime of implants. A clear understanding of these important issues will facilitate the development of novel strategies to improve the longevity and function of implants for joint replacement in the future. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Protein recognition onto silica particles using chitosan as intermedium substrate
Authors: Xia Yong‐Qing , Guo Tian‐Ying , Zhao Hai‐Li , Song Mou‐Dao , Zhang Bang‐Hua , Zhang Bao‐Long
Published: May 2008

A novel molecular imprinting method was used to prepare twice‐coated silica particles with specific recognition sites for hemoglobin. Chitosan was used as an intermedium to be coated on silica particles via phase inversion process, and the abundance of exposed amine groups (NH2) were active sites for introducing aldehyde groups. After hemoglobin was covalently immobilized by forming imine bonds with the aldehyde groups, acrylamide was then polymerized onto chitosan‐coated silica particles to form the recognition sites. The obtained hemoglobin imprinted [molecularly imprinted polymer (MIP)] beads were characterized by FTIR spectroscopy, thermogravimetric analysis (TG), and scanning electron microscopy (SEM). The MIP particles exhibited selectively adsorption for the imprinted protein compared to the nonselectively adsorption for most of proteins of the nonimprinted (NIP) beads. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Novel poly(HEMA‐co‐METAC)/alginate semi‐interpenetrating hydrogels for biomedical applications: Synthesis and characterization
Authors: La Gatta Annalisa , Schiraldi Chiara , Esposito Annaclaudia , D'Agostino Antonella , De Rosa Alfredo
Published: May 2008

Novel p(HEMA‐co‐METAC)/alginate semi‐interpenetrating hydrogels (semi‐IPNs) were developed in the attempt to improve poly(hydroxyethylmethacrylate) biological response, extending its applications in the biomedical field. Materials with different alginate contents were synthesized by copolymerization of 2‐hydroxyethylmethacrylate and 2‐methacryloxy ethyltrimethyl ammonium chloride monomers in the presence of aqueous solutions of alginate and characterized with respect to p(HEMA‐co‐METAC) synthesized in the presence of water. Swelling studies in water revealed high values of water uptake (>100%) with marked differences in the swelling degree at increasing polysaccharide content. The effect of ionic strength and of pH on the swelling behavior of hydrogels was also investigated. Higher ionic strengths resulted in a minor swelling degree accordingly with hydrogels polyelectrolyte nature. The introduction of the natural ionizable polysaccharide into the network made the semi‐IPNs swelling depending on pH values of the solutions. A biological characterization was performed in terms of protein absorption on hydrogel surfaces, cytotoxicity (ISO 10993‐5) and cell adhesion and proliferation studies using both murine 3T3 and human fibroblasts. Hydrogels proved noncytotoxic; moreover, semi‐IPN surfaces allowed cell attachment and proliferation, thus supporting their potential biomedical use. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Abrogation of the inflammatory response in LPS‐stimulated RAW 264.7 murine macrophages by Zn‐ and Cu‐doped bioactive sol–gel glasses
Authors: Varmette Elizabeth A. , Nowalk Jessica R. , Flick Lisa M. , Hall Matthew M.
Published: May 2008

The attenuation of an in vitro inflammatory response in RAW 264.7 murine macrophages stimulated with lipopolysaccharide (LPS) endotoxin was tested using sol–gel‐derived bioactive glasses. Three general types of sol–gel‐derived samples were evaluated: 58S, zinc‐containing glasses, and copper‐containing glasses. Distinct experimental procedures were used to test the potential of bioactive glasses to attenuate the inflammatory response in three situations: (1) therapeutically following LPS stimulation, (2) prophylactically before LPS stimulation of macrophages, and (3) indirectly via the glass dissolution products after stimulation with LPS. A sandwich enzyme‐linked immunosorbent assay (ELISA) was used to monitor the concentration of tumor necrosis factor‐α (TNF‐α) secreted by macrophage cells. The strongest reduction in TNF‐α concentration was observed when macrophage cells were first incubated with bioactive glass powder and then stimulated with LPS. This suggests a possible prophylactic application of these bioactive glasses for the prevention of inflammation. The 58S glass was capable of reducing the expression of TNF‐α by macrophages, although the zinc‐ and copper‐containing were more effective at suppressing the inflammatory response. The additional benefit of using zinc‐ and copper‐doped bioactive glasses may be explained by the direct interactions of zinc and copper ions in key regulatory pathways for the inflammation response. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Intracerebral microinjection of stannous 2‐ethylhexanoate affects dopamine turnover in cerebral cortex and locomotor activity in rats
Authors: Yamada Takashi , Jung Duk‐Young , Sawada Rumi , Tsuchiya Toshie
Published: May 2008

Stannous 2‐ethylhexanoate [Sn(Oct)2] is used as a catalyst for production of poly‐L‐lactic acid and copolymers that are implanted in cranial surgery, but reports on its effects on the central nervous system are few. We examined the effects of Sn(Oct)2 on cell viability in vitro and on neurotransmission and behavior in the rat. Treatment of normal human astrocytes with 10 mg/mL Sn(Oct)2 reduced mitochondrial activity to 16% of the control. Injection of Sn(Oct)2 at 6.28 mg/kg BW (2 mg/kg BW Sn) into right lateral ventricle of the rat brain tended to increase the ambulation distance after 30 days when compared with the control group. The turnover of dopamine neurotransmission was increased in the cerebral cortex. These results suggest that Sn(Oct)2 is cytotoxic to astrocytes in vitro. Injection of Sn(Oct)2 into the brain had no or very weak immediate neurotoxicity, but long‐term exposure to Sn(Oct)2 increased dopamine neurotransmission turnover. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Hydroxylation of dental zirconia surfaces: Characterization and bonding potential
Authors: Lohbauer Ulrich , Zipperle Marita , Rischka Klaus , Petschelt Anselm , Müller Frank A
Published: May 2008

Bioinert 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

The 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

Cadmium (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

Stem 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

The 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

Stable 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

Clinical 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

A 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

Noncovalent 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

Nonsteroidal 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

Ischemic 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

The 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

Melanin 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

Background

The aim of the present study was to objectively assess the physical activity levels of patients after tumor prosthesis implantation with two objective measurement devices.

Methods

The 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.

Results

In 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.

Conclusions

Even 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

The 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

In 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
Compact microstrip bandpass filter using modified stepped‐impedance hairpin resonator
Authors: Tu Wen‐Hua
Published: May 2008

A modified compact stepped‐impedance hairpin resonator using an interdigital capacitor and its application to a bandpass filter design are presented. In comparison to the coupled line of a conventional stepped‐impedance hairpin resonator, the interdigital capacitor of the proposed resonator achieves a bigger parallel capacitance. Hence, the proposed resonator can achieve a compact size and a wider harmonic‐free bandwidth. Comparing the measured results of the two bandpass filters using the conventional resonators or the modified resonators suggests that the bandpass filter using the proposed resonators achieves a superior performance. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2007–2010, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23559
A GSM signals‐based positioning technique for mobile applications
Authors: Azaro R. , Donelli M. , Benedetti M. , Rocca P. , Massa A.
Published: May 2008

A mobile positioning system based on GSM signals analysis and on a cooperative stochastic optimization algorithm is presented. The proposed technique is intended as a backup solution in those applicative scenarios where the GPS system fails to work (e.g.,urban canyons). The hardware architecture of the system and the positioning algorithm are described and validated by means of a numerical assessment. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2128–2130, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23568
Parametric analysis of microstrip lines loaded with complementary split ring resonators
Authors: Bonache Jordi , Gil Marta , García‐Abad Oscar , Martín Ferran
Published: May 2008

In this article, the effects of varying the geometry of complementary split ring resonators (CSRRs) in microstrip lines loaded with such resonant elements is analyzed. Specifically, from a parameter extraction technique previously proposed by some of the authors, the electrical parameters of CSRR‐loaded lines (namely, the line inductance, the inductance and capacitance of the CSRR, and the coupling capacitance between the line and the CSRRs), are inferred. This analysis is of interest because, in spite of the existence of analytical models that predict the electrical parameters of these CSRR‐loaded lines, the validity of these models is limited, and the parameter extraction method is necessary to accurately determine the electrical parameters from geometry. From the analysis carried out in this work, interesting conclusions for the design of CSRR‐loaded lines are obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2093–2096, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23571
Analysis of a compact and broadband microstrip patch antenna
Authors: Ansari Jamshed A. , Ram Ram Brij
Published: May 2008

A broadband microstrip patch antenna with U‐shaped parasitic elements is proposed and analyzed using equivalent circuit theory concept. The effects of gap between the main patch and the U‐shaped parasitic elements, substrate thickness, and the feed point location are analyzed to obtain the optimum conditions for broadband operation of the antenna. The antenna shows an operational frequency band from 4.88 to 6.44 GHz with 28.36% bandwidth at center frequency 5.5 GHz. The radiation patterns of the proposed antenna are similar to that of a rectangular patch. The antenna shows 3‐dB beam width of 98.6° at lower resonance frequency whereas it is 77.6° at higher resonance frequency. The theoretical results are in good agreement with experimental results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2059–2063, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23573
The band‐notch function for a printed ultra‐wideband monopole antenna with E‐shaped slot
Authors: Cui Zhen , Jiao Yong‐Chang , Zhang Li , Zhang Fu‐Shun
Published: May 2008

In this study, a printed rectangular monopole antenna with a band‐notch function is proposed for ultra‐wideband (UWB) applications. The notched frequency band is achieved by embedding an E‐slot in the rectangular radiation patch. The notched frequency band can be controlled by adjusting the location, length, and the width of the slot. A design example for an UWB monopole antenna with a notched frequency band at 5 GHz is demonstrated. The antenna also shows omnidirectional radiation patterns across the whole operating bandwidth that is suitable for UWB applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2048–2052, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23582
An enhanced bandwidth design technique for Peano fractal loaded monopole antenna
Authors: Yan‐min Yu , Yi‐ming Tang , Wen Wu
Published: May 2008

A new technique for Peano fractal loaded monopole antenna to enhance impedance bandwidth by loading shorting pins is presented. Simulated and measured data show that relative impedance bandwidths of the proposed order 1 and order 2 antennas achieve 23 and 28% for VSWR less than 2 in L‐band, which are enhanced 90 and 75% than those of conventional ones, respectively, while the profile and radiation patterns change little. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2045–2048, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23583