bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping of novel peptides of WT-1 and presenting HLA alleles that induce epitope-specific HLA-restricted T cells with cytotoxic activity against WT-1+ leukemias
Authors: Doubrovina Ekaterina , Carpenter Taissia , Pankov Dmitry , Selvakumar Annamalai , Hasan Aisha , O'Reilly Richard J.
Published: May 2012

The Wilms tumor protein (WT-1) is widely recognized as a tumor antigen that is expressed differentially by several malignancies. However, WT-1 peptides known to induce tumoricidal T cells are few. In the present study, we evaluated T-cell responses of 56 healthy donors to in vitro sensitization with autologous APCs loaded with a pool of overlapping 15-mer peptides spanning the sequence of WT-1. Thereafter, we mapped the WT-1 peptides eliciting responses in each individual, defined the immunogenic peptides, and identified their presenting HLA alleles. We report 41 previously unreported epitopes of WT-1: 5 presented by class II and 36 by class I alleles, including 10 that could be presented by more than 1 class I allele. IFNγ+ T cells responding to 98% of the class I and 60% of the class II epitopes exhibited HLA-restricted cytotoxicity against peptide-loaded targets. T cells specific for 36 WT-1 peptides were evaluable for leukemocidal activity, of which 27 (75%) lysed WT-1+ leukemic targets sharing their restricting HLA allele. Each epitope identified induced T-cell responses in most donors sharing the epitopes' presenting allele; these responses often exceeded responses to flanking peptides predicted to be more immunogenic. This series of immunogenic epitopes of WT-1 should prove useful for immunotherapies targeting WT-1+ malignancies.
ADAM17 activation in circulating neutrophils following bacterial challenge impairs their recruitment
Authors: Long Chunmei , Hosseinkhani M Reza , Wang Yue , Sriramarao P , Walcheck Bruce
Published: May 2012

ADAM17 functions as a molecular rheostat to control neutrophil influx at sites of infection by regulating the surface density of L-selectin.

Neutrophil infiltration and bacterial clearance occur earlier in conditional knockout mice with leukocytes lacking the metalloprotease ADAM17 than in control mice. We investigated cell-intrinsic changes in neutrophils lacking ADAM17 and alterations in the inflammatory environment in conditional ADAM17 knockout mice to determine how the sheddase exerts its effects on neutrophil recruitment. In vivo analyses comparing control and ADAM17-deficient neutrophils revealed that the latter cells accumulated at increased levels in the inflamed mesenteric microvasculature and in the peritoneal cavity following bacterial challenge, indicating changes in their adhesive properties. Consistent with this, bacterial infection caused a marked down-regulation of L-selectin, an adhesion protein and substrate of ADAM17, from the surface of circulating neutrophils in control mice but not in conditional ADAM17 knockout mice. Neutrophils from gene-targeted mice with leukocytes expressing a noncleavable form of L-selectin also displayed a competitive advantage in the presence of control neutrophils when infiltrating a site of infection. Taken together, our findings reveal that impaired L-selectin shedding is a key mechanism underlying early neutrophil recruitment in conditional ADAM17 knockout mice during bacterial infection. Disrupting only the shedding of L-selectin, however, did not increase bacterial clearance, indicating that additional substrates also contribute to the detrimental role of ADAM17 during severe infection.
Novel mechanisms of early upper and lower urinary tract patterning regulated by RetY1015 docking tyrosine in mice
Authors: Hoshi Masato , Batourina Ekatherina , Mendelsohn Cathy , Jain Sanjay
Published: May 2012

Mutations in the receptor tyrosine kinase RET are associated with congenital anomalies of kidneys or urinary tract (CAKUT). RET tyrosine Y1015 is the docking site for PLCγ, a major regulator of RET signaling. Abrogating signaling via Y1015 causes CAKUT that are markedly different than renal agenesis in Ret-null or RetY1062F mutant mice. We performed analysis of Y1015F mutant upper and lower urinary tracts in mice to delineate its molecular and developmental roles during early urinary tract formation. We found that the degeneration of the common nephric ducts (CND), the caudal-most Wolffian duct (WD) segment, depends on Y1015 signals. The CNDs in Y1015F mutants persist owing to increased proliferation and reduced apoptosis, and showed abundance of phospho-ERK-positive cells. In the upper urinary tract, the Y1015 signals are required for proper patterning of the mesonephros and metanephros. Timely regression of mesonephric mesenchyme and proper demarcation of mesonephric and metanephric mesenchyme from the WD depends on RetY1015 signaling. We show that the mechanism of de novo ectopic budding is via increased ERK activity due to abnormal mesenchymal GDNF expression. Although reduction in GDNF dosage improved CAKUT it did not affect delayed mesenchyme regression. Experiments using whole-mount immunofluorescence confocal microscopy and explants cultures of early embryos with ERK-specific inhibitors suggest an imbalance between increased proliferation, decreased apoptosis and increased ERK activity as a mechanism for WD defects in RetY1015F mice. Our work demonstrates novel inhibitory roles of RetY1015 and provides a possible mechanistic explanation for some of the confounding broad range phenotypes in individuals with CAKUT.
Gut endoderm is involved in the transfer of left-right asymmetry from the node to the lateral plate mesoderm in the mouse embryo
Authors: Saund Ranajeet S. , Kanai-Azuma Masami , Kanai Yoshiakira , Kim Injune , Lucero Mary T. , Saijoh Yukio
Published: May 2012

In the mouse, the initial signals that establish left-right (LR) asymmetry are determined in the node by nodal flow. These signals are then transferred to the lateral plate mesoderm (LPM) through cellular and molecular mechanisms that are not well characterized. We hypothesized that endoderm might play a role in this process because it is tightly apposed to the node and covers the outer surface of the embryo, and, just after nodal flow is established, higher Ca2+ flux has been reported on the left side near the node, most likely in the endoderm cells. Here we studied the role of endoderm cells in the transfer of the LR asymmetry signal by analyzing mouse Sox17 null mutant embryos, which possess endoderm-specific defects. Sox17–/– embryos showed no expression or significantly reduced expression of LR asymmetric genes in the left LPM. In Sox17 mutant endoderm, the localization of connexin proteins on the cell membrane was greatly reduced, resulting in defective gap junction formation, which appeared to be caused by incomplete development of organized epithelial structures. Our findings suggest an essential role of endoderm cells in the signal transfer step from the node to the LPM, possibly using gap junction communication to establish the LR axis of the mouse.
β-Catenin gain of function in muscles impairs neuromuscular junction formation
Authors: Wu Haitao , Lu Yisheng , Barik Arnab , Joseph Anish , Taketo Makoto Mark , Xiong Wen-Cheng , Mei Lin
Published: May 2012

Neuromuscular junction (NMJ) formation requires proper interaction between motoneurons and muscle cells. β-Catenin is required in muscle cells for NMJ formation. To understand underlying mechanisms, we investigated the effect of β-catenin gain of function (GOF) on NMJ development. In HSA-β-catflox(ex3)/+ mice, which express stable β-catenin specifically in muscles, motor nerve terminals became extensively defasciculated and arborized. Ectopic muscles were observed in the diaphragm and were innervated by ectopic phrenic nerve branches. Moreover, extensive outgrowth and branching of spinal axons were evident in the GOF mice. These results indicate that increased β-catenin in muscles alters presynaptic differentiation. Postsynaptically, AChR clusters in HSA-β-catflox(ex3)/+ diaphragms were distributed in a wider region, suggesting that muscle β-catenin GOF disrupted the signal that restricts AChR clustering to the middle region of muscle fibers. Expression of stable β-catenin in motoneurons, however, had no effect on NMJ formation. These observations provide additional genetic evidence that pre- and postsynaptic development of the NMJ requires an intricate balance of β-catenin activity in muscles.
Smad ubiquitination regulatory factor-2 controls gap junction intercellular communication by modulating endocytosis and degradation of connexin43
Authors: Fykerud Tone Aase , Kjenseth Ane , Schink Kay Oliver , Sirnes Solveig , Bruun Jarle , Omori Yasufumi , Brech Andreas , Rivedal Edgar , Leithe Edward
Published: May 2012

Gap junctions consist of arrays of intercellular channels that enable adjacent cells to communicate both electrically and metabolically. Gap junction channels are made of a family of integral membrane proteins called connexins, of which the best-studied member is connexin43. Gap junctions are dynamic plasma membrane domains, and connexin43 has a high turnover rate in most tissue types. However, the mechanisms involved in the regulation of connexin43 endocytosis and transport to lysosomes are still poorly understood. Here, we demonstrate by live-cell imaging analysis that treatment of cells with 12-O-tetradecanoylphorbol 13-acetate (TPA) induces endocytosis of subdomains of connexin43 gap junctions. The internalized, connexin43-enriched vesicles were found to fuse with early endosomes, which was followed by transport of connexin43 to the lumen of early endosomes. The HECT E3 ubiquitin ligase smad ubiquitination regulatory factor-2 (Smurf2) was found to be recruited to connexin43 gap junctions in response to TPA treatment. Depletion of Smurf2 by small interfering RNA (siRNA) resulted in enhanced levels of connexin43 gap junctions between adjacent cells and increased gap junction intercellular communication. Smurf2 depletion also counteracted the TPA-induced endocytosis and degradation of connexin43. Collectively, these data identify Smurf2 as a novel regulator of connexin43 gap junctions.
CAS-1, a C. elegans cyclase-associated protein, is required for sarcomeric actin assembly in striated muscle
Authors: Nomura Kazumi , Ono Kanako , Ono Shoichiro
Published: May 2012

Assembly of contractile apparatuses in striated muscle requires precisely regulated reorganization of the actin-cytoskeletal proteins into sarcomeric organization. Regulation of actin filament dynamics is one of the essential processes of myofibril assembly, but the mechanism of actin regulation in striated muscle is not clearly understood. Actin depolymerizing factor (ADF)/cofilin is a key enhancer of actin filament dynamics in striated muscle in both vertebrates and nematodes. Here, we report that CAS-1, a cyclase-associated protein in Caenorhabditis elegans, promotes ADF/cofilin-dependent actin filament turnover in vitro and is required for sarcomeric actin organization in striated muscle. CAS-1 is predominantly expressed in striated muscle from embryos to adults. In vitro, CAS-1 binds to actin monomers and enhances exchange of actin-bound ATP/ADP even in the presence of UNC-60B, a muscle-specific ADF/cofilin that inhibits the nucleotide exchange. As a result, CAS-1 and UNC-60B cooperatively enhance actin filament turnover. The two proteins also cooperate to shorten actin filaments. A cas-1 mutation is homozygous lethal with defects in sarcomeric actin organization. cas-1-mutant embryos and worms have aggregates of actin in muscle cells, and UNC-60B is mislocalized to the aggregates. These results provide genetic and biochemical evidence that cyclase-associated protein is a critical regulator for sarcomeric actin organization in striated muscle.
Sho1p connects the plasma membrane with proteins of the cytokinesis network via multiple isomeric interaction states
Authors: Labedzka Karolina , Tian Chen , Nussbaumer Ute , Timmermann Steffi , Walther Paul , Müller Judith , Johnsson Nils
Published: May 2012

A molecular understanding of cytokinesis requires the detailed description of the protein complexes that perform central activities during this process. The proteins Hof1p, Cyk3p, Inn1p, and Myo1p each represent one of the four genetically defined and partially complementing pathways of cytokinesis in the yeast Saccharomyces cerevisiae. Here we show that the osmosensor Sho1p is required for correct cell-cell separation. Shortly before cytokinesis Sho1p sequentially assembles with Hof1p, Inn1p, and Cyk3p, into a complex (HICS-complex) that might help to connect the membrane with the actin-myosin ring. The HICS-complex is formed exclusively via the interactions between three SH3 domains located in Cyk3p, Hof1p, and Sho1p, and five acceptor sites found in Cyk3p, Hof1p, and Inn1p. Due to the overlapping binding specificities of its members the HICS-complex is best described as ensembles of isomeric interaction states that precisely coordinate the different functions of the interactors during cytokinesis.
Scrib regulates HGF-mediated epithelial morphogenesis and is stabilized by Sgt1-HSP90
Authors: Eastburn Dennis J. , Zegers Mirjam M. , Mostov Keith E.
Published: May 2012

Scribble was originally identified as a Drosophila protein that regulates epithelial polarity and formation of the basolateral surface. The mammalian orthologue, Scrib, is evolutionarily conserved, but does not appear to be necessary for apical-basolateral epithelial polarity. Instead, it is implicated in the regulation of cell survival, protein trafficking, adhesion and migration. A key issue is to understand the molecular pathway by which Scrib participates in these processes. Here, we investigate Scrib using a 3D epithelial cell culture system. We show a novel association between the LRR domain of Scrib and the co-chaperone Sgt1 and demonstrate that these proteins are necessary for epithelial morphogenesis and tubulogenesis following HGF stimulation. The molecular chaperone HSP90 is also required for Sgt1 association with Scrib, and both Sgt1 and HSP90 are needed to ensure proper Scrib protein levels. Furthermore, reduced Scrib stability, following inhibition of Sgt1-HSP90, lowers the cellular abundance of the Scrib-βPix-PAK complex. Inhibition of any member of this complex, Scrib, βPix or PAK, is sufficient to block HGF-mediated epithelial morphogenesis. The identification of Scrib as an Sgt1-HSP90 client protein required for 3D cell migration suggests that chaperone-mediated regulation of polarity protein stability and homeostasis is an unappreciated mechanism underlying dynamic rearrangements during morphogenesis.
Development of Ammonia Gas Sensors Based on Trivalent Al3+ Cation Conducting Solid Electrolyte
Authors: Nagai Tsukasa , Tamura Shinji , Imanaka Nobuhito
Published: May 2012

Solid electrolyte type ammonia (NH3) gas sensors were fabricated using Al3+ ion conducting (Al0.2Zr0.8)20/19Nb(PO4)3 solid electrolyte with an aluminum thin film as a reference electrode. A rare-earth ammonium sulfate double salt of R2(SO4)3·(NH4)2SO4 (R = rare earth) or a lanthanum oxysulfate La2O2SO4-based solid solution was selected as the auxiliary sensing electrode on the basis of thermal stability or water durability. Both sensors with R2(SO4)3·(NH4)2SO4 or La2O2SO4–NH4H2PO4 auxiliary sensing electrodes exhibited a quantitative and theoretical NH3 sensing performance at 230–300 or 170–190 °C, respectively; therefore, sensors based on the (Al0.2Zr0.8)20/19Nb(PO4)3 solid electrolyte are expected to be promising candidates as NH3 detectors that can operate in a wide temperature range of 170–300 °C by changing the auxiliary sensing electrode component.
Observation of Different Molecular Alignments of [Ni(salphen)] Substituted by a Different Number of Octyl Groups at HOPG Surface
Authors: Tamaki Yoshinori , Tomono Kazuaki , Hata Yuki , Saita Nanami , Yamamoto Takashi , Miyamura Kazuo
Published: May 2012

The surface adsorption structures of two Schiff-base metal complexes, [N,N′-bis(5-octylsalicylidene)-o-phenylenediaminato]nickel(II) (1) and [N,N′-bis(3,5-dioctylsalicylidene)-o-phenylenediaminato]nickel(II) (2), are imaged using scanning tunneling microscopy (STM), and compared with the dimeric structure predicted by single-crystal X-ray diffraction and NMR analyses. STM images of 1 and 2 obtained at an o-dichlorobenzene/HOPG interface showed that 1 was adsorbed in the form of dimers, while 2 was adsorbed as monomers at HOPG surface. The surface structure of 1 was similar to that of the reported salen complex analogue. 1H NMR measurement revealed that the equilibrium constants of dimer formation for 1 and 2 in chloroform-d were determined to be K (= [dimer]/[monomer]2) = 14.5 and 1.9 mol−1 dm3, respectively. This decreased tendency of 2 to form dimer is concluded to be the reason why 2 did not form dimers at HOPG surface. The crystal structure of 1 in which 1 is found to form dimers is also presented.
Design and Applications of Artificial Restriction DNA Cutters for Site-Selective Scission of Genomes
Authors: Komiyama Makoto , Sumaoka Jun
Published: May 2012

By combining Ce(IV)/EDTA complex and pseudo-complementary peptide nucleic acid (pcPNA), an artificial restriction DNA cutter which hydrolyzes targeted phosphodiester linkages in double-stranded DNA has been developed. The targeted site in the DNA is activated by two strands of pcPNA and selectively hydrolyzed by the Ce(IV) complex. The DNA cutter required for aimed manipulation can be straightforwardly designed and obtained in terms of (i) the sequence of targeted selective scission, (ii) size of DNA substrate, and (iii) magnitude of desired site-specificity. The site-specificity can be high enough to cut the whole genome of human beings (3 × 109 base-pairs) at one predetermined site. Off-target scissions at the sites of analogous sequences hardly take place. With the use of this specificity, targeted gene can be engineered in human cells through homologous recombination. Other potential applications of this cutter, as well as recent attempts to improve its activity and specificity, are also discussed.
One-Step Synthesis and Association of Alkylimidovanadium(V) Compounds
Authors: Nishina Masafumi , Moriuchi Toshiyuki , Hirao Toshikazu
Published: May 2012

One-step synthesis of alkylimidovanadium(V) triisopropoxides was demonstrated by the reaction of the corresponding alkylamines with [VO(Oi-Pr)3] in the presence of sodium hydride as a base under relatively mild conditions. From the reaction of 1-adamantylamine, [V(adN)(Oi-Pr)3] (ad: 1-adamantyl) was obtained. The chiral mononuclear compound having the amino moiety, [V(2-NH2C6H10N)(Oi-Pr)3], was synthesized from the reaction of (1R,2R)- or (1S,2S)-1,2-cyclohexanediamine with a stoichiometric amount of [VO(Oi-Pr)3]. In a solid state, [V(2-NH2C6H10N)(Oi-Pr)3] is present in a polymeric molecular arrangement through the intermoleculer coordination interaction of the amino group to the vanadium metal center. The use of trans-1,4-cyclohexanediamine resulted in the binuclear compound [{V(Oi-Pr)3}2(µ-trans-1,4-C6H10N2)], which forms an alkoxide-bridged polymeric structure. Crystallization of a 1:1 mixture of [{V(Oi-Pr)3}2(µ-trans-1,4-C6H10N2)] and trans-1,4-cyclohexanediamine gave the 1:1 complex having a polymeric arrangement based on the coordination of the amino groups.
Linker-Length Dependence of Crystal Structures and Thermal Properties of Bis(imidazolium) Salts with Tetrafluoroborate Anion
Authors: Mandai Toshihiko , Masu Hyuma , Seki Hiroko , Nishikawa Keiko
Published: May 2012

A series of bis(imidazolium) salts with several n-alkylene linkers (carbon numbers: 4–8) incorporating tetrafluoroborate anions were characterized by thermal analysis and single-crystal X-ray analysis. A correlation between macroscopic thermal properties and microscopic crystal structures was investigated. A unique linker-length dependence of the melting points of bis(imidazolium) salts is attributed to variations in the molecular conformation and the packing structure resulting from a balance among cooperative ionic interaction, van der Waals interaction, and π–π interaction in the crystalline state. In addition, an even–odd effect of the n-alkylene linker was observed in the crystal structures.
NMR Spectroscopic Evidence of Lewis Acid–Lewis Base Complex Formation of Perfluoroborane with Uranyl β-Diketonato Complexes
Authors: Miyamoto Naomi , Tsukahara Takehiko , Ikeda Yasuhisa
Published: May 2012

Interactions between B(C6F5)2OH and [UO2(dfh)2(dmso)] or [UO2(acac)2(dmso)] in toluene have been investigated by 11B- and 19F NMR measurements. The results showed that one or two B(C6F5)2OH molecules coordinate to the oxo ligands of [UO2(acac)2(dmso)] through B, i.e., O=U=O···B (1:1) and B···O=U=O···B (2:1) complexes based on Lewis acid–Lewis base (LA–LB) interactions are formed, while such LA–LB interactions are not observed in [UO2(dfh)2(dmso)]. Furthermore, it was clarified that the 2:1 complex becomes predominant with decreasing temperatures.
Li-insertion/extraction Properties of Si Thick-film Anodes in Ionic Liquid Electrolytes Based on Bis(fluorosulfonyl)amide and Bis(trifluoromethanesulfonyl)amide Anions
Authors: Usui Hiroyuki , Masuda Toshikazu , Sakaguchi Hiroki
Published: May 2012

Charge–discharge cycling performances of Si thick-film electrodes as Li-ion battery anodes were investigated in several ionic liquids based on bis(fluorosulfonyl)amide (FSA) and bis(trifluoromethanesulfonyl)amide (TFSA) anions. The Si electrodes in FSA-based electrolytes exhibited much better performance than those in TFSA-based electrolytes. An easier desolvation of Li from anions on the electrode surface is probably promoted in FSA-based electrolytes, which enables efficient electrode reactions of Li-insertion/extraction and improvement of cycling performances.
Control of Cellular Inflammation by Layer-by-layer Nanofilms through Different Driving Forces
Authors: Kadowaki Koji , Matsusaki Michiya , Akashi Mitsuru
Published: May 2012

Layer-by-layer-assembled nanofilms prepared by different driving forces were directly fabricated onto a cell surface to control cellular inflammation. Polyelectrolyte multilayers (electrostatic interaction) induced an over 2.5-fold higher production of the inflammatory cytokine interleukin-6 (IL-6) than fibronectin (FN)-based multilayers (biological recognition), which did not show any significant production of IL-6. Moreover, thick FN-based nanofilms showed lower expression of IL-6 than thin ones. This is the first report of controlling cellular inflammation by directly prepared nanofilms on a cell surface.
Polarity-dependent Photophysical Properties of Hemicyanine Dyes and Their Application in 2-Photon Microscopy Biological Imaging
Authors: Kimura Yuta , Momotake Atsuya , Takahashi Noriko , Kasai Haruo , Arai Tatsuo
Published: May 2012

Two fluorescent hemicyanine type compounds, 1 and 2 have been developed for membrane staining, and their photophysical properties were investigated in various solvents. The demonstrated 2-photon-microscopy-biological-imaging application indicates the usefulness of 1 as a fluorescent probe.
Enhanced Mechanical Strength of Nickel–Copper-coated Carbon Fiber/Magnesium Alloy Composites Fabricated Using Powder Metallurgy
Authors: Inoue Yuki , Kim Jae-Ho , Yonezawa Susumu , Takashima Masayuki
Published: May 2012

Carbon fibers could be deposited uniformly with duplex coatings of nickel (the internal layer) and copper (the external layer) using an electroplating process. The thickness of Ni and Cu coatings was about 1–2 µm. Furthermore alloying between Ni and Cu films and alloying between Cu and base Mg alloy occurred respectively after hot pressing (673 K, 2.5 MPa). In particular the strain to failure of magnesium composites with Ni–Cu-coated carbon fibers was 0.7% higher than that (1.81%) of magnesium composites with untreated carbon fibers.
Electrochemical Response of β-Galactosidase- and Glucose Oxidase-containing Microcapsule-immobilized Electrode
Authors: Shitanda Isao , Itagaki Masayuki , Asano Kaori
Published: May 2012

A polyamide microcapsule containing bi-enzyme, β-galactosidase (β-Gal) and glucose oxidase (GOD), was prepared by interfacial polymerization. The average diameter of the microcapsule was evaluated to be 5 µm. The bi-enzyme-containing microcapsule was immobilized with tetrathiafulvalene on a carbon electrode surface and was characterized by cyclic voltammetry. The oxidation current increased with the increase of the lactose concentration. It was concluded that β-Gal and GOD retained their enzymatic activity in the microcapsule and reacted with lactose, and tetrathiafulvalene penetrated the polyamide membrane.
A Study on Ion Selectivity by Sulfur Compound Self-assembled Monolayer
Authors: Xi Haitao , Sun Yiqun , Chen Ying , Sun Xiaoqiang
Published: May 2012

3-[4-(benzyloxy)phenoxy]propane isothiourea and 3-[4-(benzyloxy)phenoxy]propanethiol were successfully synthesized by a straightforward reaction. The self-assembled monolayers (SAMs) of 3-[4-(benzyloxy)phenoxy]propane isothiourea and 3-[4-(benzyloxy)phenoxy]propanethiol on the gold electrode as ion-selective electrode showed special capacity in recognition for Ag+.
Visible Light Responsive TiO2 Photocatalyst Prepared by Anodization of Ti–6Al–4V Alloy
Authors: Mizukoshi Yoshiteru , Masahashi Naoya
Published: May 2012

Titanium alloy Ti–6Al–4V was galvanostatically anodized in an aqueous acetic acid electrolyte followed by annealing to form anatase-structured TiO2. The formed pale yellowish oxide contained Al3+, V5+, and V4+ in the topmost surface of the anodized oxide. The anodized TiO2 photocatalytically decomposed acetaldehyde under visible light illumination (>400 nm).
New Synthetic Opportunities in Miniaturized Flow Reactors with Inductive Heating
Authors: Kirschning Andreas , Kupracz Lukas , Hartwig Jan
Published: May 2012

Inductive heating has emerged as a new heating technique in the laboratory, particularly when combined with miniaturized flow reactor devices. Traditionally, inductive heating is found in industrial applications like the heating of large metallic objects such as in the bending of pipes, bonding and welding. New fields of application are the preparation of nanotubes as well as hyperthermia in the treatment of cancer. This account specifically addresses the use of heatable materials such as superparamagnetic iron oxide nanoparticles in many areas of organic synthesis and how this enabling technology compares to conventional as well as microwave heating.
Efficient Hydration of Nitriles Promoted by Simple Amorphous Manganese Oxide Using Reduced Amounts of Water
Authors: Yamaguchi Kazuya , Wang Ye , Kobayashi Hiroaki , Mizuno Noritaka
Published: May 2012

Hydration of various kinds of nitriles could efficiently be promoted by amorphous MnO2 using reduced amounts of water (2 equiv or less), giving the corresponding primary amides in moderate to high yields. The observed catalysis was truly heterogeneous, and the retrieved MnO2 could be reused without an appreciable loss of its high catalytic performance.
Magnetically Separable CuFe2O4 Nanoparticle Catalyzed C–Se Cross Coupling in Reusable PEG Medium
Authors: Reddy K Harsha Vardhan , Satish G , Ramesh K , Karnakar K , Nageswar Y V D
Published: May 2012

A simple and efficient procedure for the synthesis of unsymmetrical diaryl selenides has been developed by magnetically separable CuFe2O4 nanoparticle catalyzed reactions of organoboranes with PhSeBr in recyclable PEG-400 medium at 80 °C and Cs2CO3 as base. Using this protocol, a variety of unsymmetrical selenides were obtained in good to excellent yields. The copper ferrite nanoparticles were magnetically separated, recycled, and reused up to four cycles.
Calcium Phosphate Mineralization Induced by Synthetic Peptides Having Different Distributions in Simulated Body Fluids
Authors: Hashizume Mineo , Kamaya Noriaki , Uchida Yuki , Matsubara Teruhiko , Sato Toshinori
Published: May 2012

Synthetic peptides having hydroxyapatite binding ability can induce calcium phosphate (CaP) mineralization in simulated body fluids. The peptides freely dispersed in the solution induce formation of peptide–CaP hybrids having sheet-like morphologies, whereas immobilized on solid substrates they induce hydroxyapatite deposition on the substrate surfaces. The results clearly show that distribution of the peptides affects their mineralization properties.
Sol–Gel-derived Bridged Polysilsesquioxane as a Hydrogen Peroxide Decomposition Catalyst: Immobilization of a Dimanganese Complex and Its Improved Thermal Stability
Authors: Saito Hitomi , Ishisone Akira , Horikawa Yuhei , Ishiyama Takeshi , Higashimura Hideyuki , Sugahara Yoshiyuki
Published: May 2012

Bridged polysilsesquioxane possessing dimanganese complex moiety, a model complex for catalase, exhibited catalytic activity for the hydrogen peroxide decomposition reaction without any deactivation. The catalytic activity was mostly retained, even after 24-h acid treatment at 80 °C, improving thermal stability after immobilization.
Intertemporal Movie Distribution: Versioning When Customers Can Buy Both Versions
Authors: Calzada Joan , Valletti Tommaso M.
Published: May 2012

We study a model of film distribution and consumption. The studio can release two goods, a theatrical version and a video version, and has to decide on its versioning and sequencing strategy. In contrast with the previous literature, we allow for the possibility that some consumers may watch both versions. This simple extension leads to novel results. It now becomes optimal to introduce versioning if the goods are not too substitute for one another, even when production costs are zero (pure information goods). We also demonstrate that the simultaneous release of the versions (“day-and-date” strategy) can be optimal when the studio is integrated with the exhibition and distribution channels. In contrast, a sequential release (“video window” strategy) is typically the outcome when the studio negotiates with independent distributors and exhibitors.
Consumer Learning of New Binary Attribute Importance Accounting for Priors, Bias, and Order Effects
Authors: Chylinski Mathew B. , Roberts John H. , Hardie Bruce G. S.
Published: May 2012

This paper develops and calibrates a simple yet comprehensive set of models for the evolution of binary attribute importance weights, based on a cue–goal association framework. We argue that the utility a consumer ascribes to an attribute comes from its association with the achievement of a goal. We investigate how associations may be represented and then track back the relationship of these associations to the utility function. We explain why we believe this to be an important problem before providing an overview of the extensive literature on learning models. This literature identifies key phenomena and provides a foundation for our modeling of binary attribute importance learning, which can test for three departures from “rational” learning—bias, existence of priors, and the unequal weighting of sample observations (order effects). We apply our models in a laboratory setting under a number of different relationship strengths, and we find that, in our application, consumers' learning about attribute–goal associations exhibits bias and the effects of prior beliefs when the sample realizations occur with and without noise, and order effects when the sample realizations occur with noise. We provide an example of how our models can be extended to learning about more than one attribute.
A Temporal Perspective on Organizational Identity
Authors: Schultz Majken , Hernes Tor
Published: May 2012

We offer as our main theoretical contribution a conceptual framework for how the past is evoked in present identity reconstruction and the ways in which the past influences the articulation of claims for future identity. We introduce the notion of textual, material, and oral memory forms as the means by which organizational actors evoke the past. The conceptual framework is applied in a study of two occasions of identity reconstruction in the LEGO Group, which revealed differences in ways that the past was evoked and influenced claims for future identity. Our study suggests that (1) a longer time perspective in the use of memory enabled a longer time perspective in formulating claims for future identity, (2) a broader scope of articulated identity claims for the future was related to the combination of a broader range of memory forms, and (3) the depth of claims for future identity was related to the way in which memory forms were combined. At a more general level, our paper illustrates how viewing identity construction from the perspective of an ongoing present adds a new dimension to understanding the temporal dynamics of organizational identity.
Balance is an important predictive factor for quality of life and function after primary total knee replacement
Authors: Schwartz I. , Kandel L. , Sajina A. , Litinezki D. , Herman A. , Mattan Y.
Published: May 2012

We investigated the extent to which improved balance relative to pain relief correlates with the success of total knee replacement (TKR). A total of 81 patients were recruited to the study: 16 men (19.8%) and 65 women (80.2%). Of these, 62 patients (10 men, 52 women) with a mean age of 73 (57 to 83) underwent static and dynamic assessment of balance pre-operatively and one year post-operatively. The parameters of balance were quantified using commercially available and validated equipment. Motor function and self-reported outcome were also assessed.

There was a significant improvement in dynamic balance (p < 0.001) one year after TKR, and better balance correlated with improved mobility, functional balance and increased health-related quality of life. As it seems that balance, and not only pain relief, influences the success of TKR, balance skills should be better addressed during the post-operative rehabilitation of patients who undergo TKR.
Arthroscopic reduction of the dislocated hip in infants
Authors: Eberhardt O. , Fernandez F. F. , Wirth T.
Published: May 2012

We present our early experience of arthroscopic reduction of the dislocated hip in very young infants with developmental dysplasia of the hip (DDH).

Eight dislocated hips, which had failed attempts at closed reduction, were treated by arthroscopy of the hip in five children with a mean age of 5.8 months (4 to 7). A two-portal technique was used, with a medial sub-adductor portal for a 2.7 mm cannulated system with a 70° arthroscope and an anterolateral portal for the instruments. Following evaluation of the key intra-articular structures, the hypertrophic ligamentum teres and acetabular pulvinar were resected, and a limited release of the capsule was performed prior to reduction of the hip. All hips were reduced by a single arthroscopic procedure, the reduction being confirmed on MRI scan. None of the hips had an inverted labrum. The greatest obstacle to reduction was a constriction of the capsule. At a mean follow-up of 13.2 months (9 to 24), all eight hips remained stable. Three developed avascular necrosis. The mean acetabular index decreased from 35.5° (30° to 40°) pre-operatively to 23.3° (17° to 28°).

This study demonstrates that arthroscopic reduction is feasible using two standardised portals. Longer follow-up studies are necessary to evaluate the functional results.
The Bologna–Oxford total ankle replacement
Authors: Bianchi A. , Martinelli N. , Sartorelli E. , Malerba F.
Published: May 2012

The Bologna–Oxford (BOX) total ankle replacement (TAR) was developed with the aim of achieving satisfactory pain-free movement of the ankle. To date, only one single multicentre study has reported its clinical results. The aim of this study was to conduct an independent review of its mid-term results.

We retrospectively reviewed a total of 60 prospectively followed patients in whom 62 BOX TARs had been implanted between 2004 and 2008. We used the American Orthopedic Foot and Ankle Society (AOFAS) score to assess the clinical results. Standardised radiographs taken at the time of final follow-up were analysed by two observers. The overall survival was 91.9% at a mean follow-up of 42.5 months (24 to 71). The mean AOFAS score had improved from 35.1 points (sd 16.6; 4 to 73) pre-operatively to 78.0 (sd 10.7; 57 to 100) at final follow-up (p < 0.01). Tibial radiolucencies < 2 mm in width were seen around 16 TARs. Talar radiolucencies < 2 mm were seen around four TARs. A total of 47 patients (78.3%) were very satisfied or satisfied with the outcome. Five patients required revision for functional limitation or continuing pain.
High incidence of pseudotumour formation after large-diameter metal-on-metal total hip replacement
Authors: Bosker B. H. , Ettema H. B. , Boomsma M. F. , Kollen B. J. , Maas M. , Verheyen C. C. P. M.
Published: May 2012

Peri-articular soft-tissue masses or ‘pseudotumours’ can occur after large-diameter metal-on-metal (MoM) resurfacing of the hip and conventional total hip replacement (THR). Our aim was to assess the incidence of pseudotumour formation and to identify risk factors for their formation in a prospective cohort study.

A total of 119 patients who underwent 120 MoM THRs with large-diameter femoral heads between January 2005 and November 2007 were included in the study. Outcome scores, serum metal ion levels, radiographs and CT scans were obtained. Patients with symptoms or an identified pseudotumour were offered MRI and an ultrasound-guided biopsy.

There were 108 patients (109 hips) eligible for evaluation by CT scan at a mean follow-up of 3.6 years (2.5 to 4.5); 42 patients (39%) were diagnosed with a pseudotumour. The hips of 13 patients (12%) were revised to a polyethylene acetabular component with small-diameter metal head. Patients with elevated serum metal ion levels had a four times increased risk of developing a pseudotumour.

This study shows a substantially higher incidence of pseudotumour formation and subsequent revisions in patients with MoM THRs than previously reported. Because most revision cases were identified only after an intensive screening protocol, we recommend close monitoring of patients with MoM THR.
Factors affecting outcome of massive intercalary bone allografts in the treatment of tumours of the femur
Authors: Frisoni T. , Cevolani L. , Giorgini A. , Dozza B. , Donati D. M.
Published: May 2012

We retrospectively reviewed 101 consecutive patients with 114 femoral tumours treated by massive bone allograft at our institution between 1986 and 2005. There were 49 females and 52 males with a mean age of 20 years (4 to 74). At a median follow-up of 9.3 years (2 to 19.8), 36 reconstructions (31.5%) had failed. The allograft itself failed in 27 reconstructions (24%).

Mechanical complications such as delayed union, fracture and failure of fixation were studied. The most adverse factor on the outcome was the use of intramedullary nails, followed by post-operative chemotherapy, resection length > 17 cm and age > 18 years at the time of intervention. The simultaneous use of a vascularised fibular graft to protect the allograft from mechanical complications improved the outcome, but the use of intramedullary cementing was not as successful.

In order to improve the strength of the reconstruction and to advance the biology of host–graft integration, we suggest avoiding the use of intramedullary nails and titanium plates, but instead using stainless steel plates, as these gave better results. The use of a supplementary vascularised fibular graft should be strongly considered in adult patients with resection > 17 cm and in those who require post-operative chemotherapy.
Do we need a gender-specific total knee replacement?
Authors: Thomsen M. G. , Husted H. , Bencke J. , Curtis D. , Holm G. , Troelsen A.
Published: May 2012

The purpose of this study was to investigate whether a gender-specific high-flexion posterior-stabilised (PS) total knee replacement (TKR) would offer advantages over a high-flex PS TKR regarding range of movement (ROM), ‘feel’ of the knee, pain and satisfaction, as well as during activity. A total of 24 female patients with bilateral osteoarthritis entered this prospective, blind randomised trial in which they received a high-flex PS TKR in one knee and a gender-specific high-flexion PS TKR in the other knee. At follow-up, patients were assessed clinically measuring ROM, and questioned about pain, satisfaction and daily ‘feel’ of each knee. Patients underwent gait analysis pre-operatively and at one year, which yielded kinematic, kinetic and temporospatial parameters indicative of knee function during gait. At final follow-up we found no statistically significant differences in ROM (p = 0.82). The median pain score was 0 (0 to 8) in both groups (p = 0.95). The median satisfaction score was 9 (4 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.98). The median ‘feel’ score was 9 (3 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.66). Gait analysis showed no statistically significant differences between the two prosthetic designs in any kinematic, kinetic or temporospatial parameters.

Both designs produced good clinical results with significant improvements in several gait parameters without evidence of any advantage in the gender-specific design.
Ceramic-on-ceramic bearings in hip arthroplasty
Authors: Jeffers J. R. T. , Walter W. L.
Published: May 2012

This systematic review of the literature summarises the clinical experience with ceramic-on-ceramic hip bearings over the past 40 years and discusses the concerns that exist in relation to the bearing combination. Loosening, fracture, liner chipping on insertion, liner canting and dissociation, edge-loading and squeaking have all been reported, and the relationship between these issues and implant design and surgical technique is investigated. New design concepts are introduced and analysed with respect to previous clinical experience.
Independent predictors of revision following metal-on-metal hip resurfacing
Authors: Jameson S. S. , Baker P. N. , Mason J. , Porter M. L. , Deehan D. J. , Reed M. R.
Published: May 2012

Modern metal-on-metal hip resurfacing has been widely performed in the United Kingdom for over a decade. However, the literature reports conflicting views of the benefits: excellent medium- to long-term results with some brands in specific subgroups, but high failure rates and local soft-tissue reactions in others. The National Joint Registry for England and Wales (NJR) has collected data on all hip resurfacings performed since 2003. This retrospective cohort study recorded survival time to revision from a resurfacing procedure, exploring risk factors independently associated with failure. All patients with a primary diagnosis of osteoarthritis who underwent resurfacing between 2003 and 2010 were included in the analyses. Cox’s proportional hazard models were used to analyse the extent to which the risk of revision was related to patient, surgeon and implant covariates.

A total of 27 971 hip resurfacings were performed during the study period, of which 1003 (3.59%) underwent revision surgery. In the final adjusted model, we found that women were at greater risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007), but the risk of revision was independent of age. Of the implant-specific predictors, five brands had a significantly greater risk of revision than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p < 0.001, Conserve: HR = 2.03, p < 0.001, Cormet: HR = 1.43, p = 0.001, Durom: HR = 1.67, p < 0.001, Recap: HR = 1.58, p = 0.007). Smaller femoral head components were also significantly more likely to require revision (≤ 44 mm: HR = 2.14, p < 0.001, 45 to 47 mm: HR = 1.48, p = 0.001) than medium or large heads, as were operations performed by low-volume surgeons (HR = 1.36, p <  0.001). Once these influences had been removed, in 4873 male patients < 60 years old undergoing resurfacing with a BHR, the five-year estimated risk of revision was 1.59%.

In summary, after adjustment for a range of covariates we found that there were significant differences in the rate of failure between brands and component sizes. Younger male patients had good five-year implant survival when the BHR was used.
Nucleophilic boron strikes back
Authors: Gulyás Henrik , Bonet Amadeu , Pubill-Ulldemolins Cristina , Solé Cristina , Cid Jessica , Fernández Elena
Published: May 2012

It has been demonstrated that the interaction of a simple Lewis base with tetraalkoxydiboranes generates an unusual nucleophilic character in one of the boryl moieties. The interaction of amines, N-heterocyclic carbenes (NHCs), and alkoxides with a diboron reagent results in the formation of a Lewis acid–base adduct, in which the formally intact sp2 boryl moiety becomes nucleophilic. We describe in this work the application of this new type of nucleophilic boron synthon in the selective preparation of organoboranes through β-boration and diboration reactions.
Flow Properties of Moisturized Powders in a Couette Fluidized Bed Rheometer
Authors: Landi Giovanna , Barletta Diego , Lettieri Paola , Poletto Massimo
Published: May 2012

This work investigates on the effect of air humidity on the flow properties of powders. The moisture of a powder sample (50 µm glass beads) was conditioned by fluidization with humid air. Air humidity was kept between 0 and 70% at ambient temperature. A Schulze shear cell was used to measure the bulk flow properties of the moisturized samples. A Couette fluidized bed rheometer was used to measure the torque necessary for the rotation of the inner cylinder when the fluidized powder had been moisturized with the same procedure. These experiments show a certain continuity of the results below and above the minimum fluidization velocity, suggesting a similar continuity of the role that interparticle interactions play in the fixed and in the fluidized bed. Experiments below the minimum fluidization velocity were interpreted with a rheological model in which the variable load along the vertical direction in the Couette was calculated with a modified Janssen equation. In this approach the apparent weight of the powder is given by the difference between the gravity and the upward body force determined by the rising gas flow. The agreement between the model and the experiments supports the proposed approach.
Prediction of the Flotsam Component in a Gas-Fluidized Bed of Two Dissimilar Solids
Authors: Di Renzo Alberto , Di Maio Francesco P. , Vivacqua Vincenzino
Published: May 2012

In the present paper the segregating behaviour of solids of different size and density in gas-fluidized beds is studied. In particular, the attention is focussed on pairs composed of a bigger/less dense species and a smaller/denser species. Typical industrial examples of such combinations are encountered in fluidized beds of biomass/sand mixtures. Their behaviour is not easily predictable, as the segregation tendency promoted by the difference in density is counteracted by the difference in size. While typically the denser component is expected to appear predominantly at the bottom of the fluidized bed, experiments on mixtures exhibiting the reverse behaviour have been reported (e.g. Chiba et al., 1980).A simple model to predict the segregation direction of the components, i.e. which species will segregate to the top of the bed (the flotsam), depending upon their difference in properties (size, density) and the mixture composition, is discussed. The predicted behaviour is compared with experimental data available in the literature and agreement is found for the majority of them. For one mixture, experiments are conducted as well as computational simulations based on the combined Discrete Element Method and Computational Fluid Dynamics (DEM-CFD) approach. This allows investigating how an initially mixed bed upon suspension evolves as a result of the segregation prevalence in the bed.