bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring customer quality in retail banking
Authors: Hand David J , Crowder Martin J
Published: May 2005

The retail banking sector makes heavy use of statistical models to predict various aspects of customer behaviour. These models are built using data from earlier customers, but have several weaknesses. An alternative approach, widely used in social measurement, but apparently not yet applied in the retail banking sector, is to use latent-variable techniques to measure the underlying key aspect of customer behaviour. This paper describes such a model that separates the observed variables for a customer into primary characteristics on the one hand, and indicators of previous behaviour on the other, and links the two via a latent variable that we identify as ‘customer quality’. We describe how to estimate the conditional distribution of customer quality, given the observed values of primary characteristics and past behaviour.
Can psychedelics have a role in psychiatry once again?
Authors: Sessa Ben
Published: June 2005

Psychedelic or hallucinogenic drugs such as lysergic acid diethylamide (LSD), 3, 4, 5-trimethoxy-β-phenethylamine (mescaline), psilocybin, 3, 4-methylenedioxymethamph-etamine (MDMA), N, N-dimethyltrypta-mine (DMT) and their relations occur in abundance throughout the natural world, and have been used by humankind for thousands of years.
Risk, psychiatry and the military
Authors: Wessely Simon
Published: June 2005

The relationship between combat and psychiatric breakdown has been well recognised for decades. The change to smaller, professional armed forces has reduced the risk of large-scale acute psychiatric casualties, and should have led to a corresponding decrease in long-term ill health, but this expected reduction seems not to have happened. Likewise, attempts at preventing psychiatric injury, by screening before deployment or debriefing after, have been disappointing. Three reasons for this are proposed: a rethinking of the relationship between trauma and long-term outcome, catalysed by the attempts of US society to come to terms with the Vietnam conflict; a broadening of the scope of psychiatric injury as it moved to the civilian sector; and the increased prominence of unexplained syndromes and contested diagnoses such as Gulf War syndrome. Traditional psychiatric injury is predictable, proportionate and can, in theory, be managed. These newer forms of injury are in contrast unanticipated, paradoxical, ill understood and hard to manage. Traditional approaches to risk management by reducing exposure have not been successful, and may increase risk aversion and reduce resilience. However, the experiences of civilians in wartime or the military show that people are not intrinsically risk-averse, provided they can see purpose in accepting risk.
Acute military psychiatric casualties from the war in Iraq
Authors: Turner Mark A. , Kiernan Mathew D. , McKechanie Andrew G. , Finch Peter J. C. , McManus Frank B. , Neal Leigh A.
Published: June 2005

Background

The view that most military personnel evacuated from war zones are suffering from combat stress reactions, or are otherwise traumatised by the horrors of war, has an impact on all aspects of military psychiatry.

Aims

To delineate the reasons for psychiatric aeromedical evacuation from Iraq from the start of build-up of UK forces in January 2003 until the end of October that year, 6 months after the end of formal hostilities.

Method

A retrospective study was conducted of field and in-patient psychiatric assessments of 116 military personnel evacuated to the UK military psychiatric in-patient facility in Catterick Garrison.

Results

Evacuees were mainly non-combatants (69%). A significant proportion were in reserve service (21%) and had a history of contact with mental health services (37%). Only 3% had a combat stress reaction. In over 85% of cases evacuation was for low mood attributed to separation from friends or family, or difficulties adjusting to the environment.

Conclusions

These findings have implications especially for screening for suitability for deployment, and for understanding any longer-term mental health problems arising in veterans from Iraq.
Pathways to psychiatric care in Eastern Europe
Authors: Gater Richard , Jordanova Vesna , Maric Nadja , Alikaj Valbona , Bajs Maja , Cavic Tamara , Dimitrov Hristo , Iosub Diana , Mihai Adriana , Szalontay Andreea Silvana , Helmchen Hanfried , Sartorius Norman
Published: June 2005

Background

There has been almost no research into mental health services in Eastern Europe. A pathways study is a quick and useful starting point, requiring few resources.

Aims

To improve understanding of prior care-seeking and treatment of new patients seen at mental health services.

Method

Pathways diagrams were drawn showing the routes of care-seeking for 50 new patients in eight centres. Patterns of care-seeking, durations and previous treatments were compared for ICD–10 diagnostic groups.

Results

The diagnoses varied according to the organisation of services. Major pathways included general practitioners, direct access and hospital doctors. General practitioners have a limited role as ‘gatekeeper’ in centres in Albania, Croatia, Macedonia, Romania and Serbia–Montenegro, and rarely prescribed treatment, except sedatives, for mental disorders.

Conclusions

Findings highlight areas that require attention if aspirations for community-oriented mental health care are to be realised, particularly integration of mental health into primary care.
Attitudes to referral to community mental health teams: a questionnaire study
Authors: Walker P. , Haeney O.G. , Naik P.C.
Published: June 2005

Aims and Method

There are no data or guidelines on who should be referred to community mental health teams (CMHTs), resulting in enormous variability in referral patterns. General practitioners (GPs) and psychiatrists were surveyed using a purpose-designed questionnaire to assess their attitudes regarding referral of individuals with different psychiatric disorders.

Results

There was consensus among GPs and psychiatrists that individuals with psychotic disorders, mania, severe depression and phobias should be referred to CMHTs. GPs were more likely to refer personality disorder, whereas the reverse was true for moderate depression and anxiety/ panic disorders. There was disagreement within groups about referral for acute stress reaction, mild depression and adjustment disorders.

Clinical Implications

Uncertainty about appropriate referral causes variability in referral patterns and service provisions. This needs resolution through the Royal Colleges of Psychiatrists and General Practitioners, to provide guidance leading to equality of care for all.
‘Brain shivers': from chat room to clinic
Authors: Christmas David M. B.
Published: June 2005

The internet is rapidly becoming a first-line source for clinicians and patients alike, and it is increasingly necessary that clinicians maintain an open dialogue with their patients about their information sources. In this paper, I look at the emergence of ‘brain shivers' as a side-effect that appears to have emerged online, in the context of antidepressant side-effects and withdrawal. I discuss possible biological explanations for this strange, possibly new, complaint, as well as the emergence of particular symptoms as a sociological phenomenon aided by new technology.
Intestinal Apolipoprotein A-IV Gene Transcription Is Controlled by Two Hormone-Responsive Elements: A Role for Hepatic Nuclear Factor-4 Isoforms
Authors: Archer Amena , Sauvaget Dominique , Chauffeton Valérie , Bouchet Pierre-Etienne , Chambaz Jean , Pinçon-Raymond Martine , Cardot Philippe , Ribeiro Agnès , Lacasa Michel
Published: June 2005

In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.
Distinct roles for twoC. elegansanillins in the gonad and early embryo
Authors: Maddox Amy Shaub , Habermann Bianca , Desai Arshad , Oegema Karen
Published: June 2005

Anillins are conserved proteins that are important for stabilizing and remodeling the actin cytoskeleton. Anillins have been implicated in cytokinesis in several systems and in cellularization of the syncytial Drosophila embryo. Here, we examine the functions of three C. elegans proteins with homology to anillin (ANI-1, ANI-2 and ANI-3). We show that ANI-1 and ANI-2 contribute to embryonic viability by performing distinct functions in the early embryo and gonad, respectively. By contrast,ANI-3 appears to be dispensable for embryonic development. ANI-1 is essential for cortical ruffling and pseudocleavage, contractile events that occur in embryos prior to mitosis. ANI-1 is also required for the highly asymmetric cytokinetic events that extrude the two polar bodies during oocyte meiosis,but is dispensable for cytokinesis following mitotic chromosome segregation. During both meiosis and mitosis, ANI-1 targets the septins, but not myosin II,to the contractile ring and does not require either for its own targeting. In contrast to ANI-1, ANI-2 functions during oogenesis to maintain the structure of the rachis, the central core of cytoplasm that connects the developing oocytes in the syncytial gonad. In ANI-2-depleted worms, oocytes disconnect prematurely from the defective rachis, generating embryos of varying sizes. Our results highlight specialization of divergent anillin family proteins in the C. elegans life cycle and reveal conserved roles for this protein family in organizing syncytial structures and cortical contractility.
Characterization ofanillinmutants reveals essential roles in septin localization and plasma membrane integrity
Authors: Field Christine M. , Coughlin Margaret , Doberstein Steve , Marty Thomas , Sullivan William
Published: June 2005

Anillin is a conserved component of the contractile ring that is essential for cytokinesis, and physically interacts with three conserved cleavage furrow proteins, F-actin, myosin II and septins in biochemical assays. We demonstrate that the Drosophila scraps gene, identified as a gene involved in cellularization, encodes Anillin. We characterize defects in cellularization,pole cell formation and cytokinesis in a series of maternal effect and zygotic anillin alleles. Mutations that result in amino acid changes in the C-terminal PH domain of Anillin cause defects in septin recruitment to the furrow canal and contractile ring. These mutations also strongly perturb cellularization, altering the timing and rate of furrow ingression. They cause dramatic vesiculation of new plasma membranes, and destabilize the stalk of cytoplasm that normally connects gastrulating cells to the yolk mass. A mutation closer to the N terminus blocks separation of pole cells with less effect on cellularization, highlighting mechanistic differences between contractile processes. Cumulatively, our data point to an important role for Anillin in scaffolding cleavage furrow components, directly stabilizing intracellular bridges, and indirectly stabilizing newly deposited plasma membrane during cellularization.
Neuronal death induced by endogenous extracellular ATP in retinal cholinergic neuron density control
Authors: Resta Valentina , Novelli Elena , Di Virgilio Francesco , Galli-Resta Lucia
Published: June 2005

The precise assembly of neuronal circuits requires that the correct number of pre- and postsynaptic neurons form synaptic connections. Neuronal cell number is thus tightly controlled by cell death during development. Investigating the regulation of cell number in the retina we found an ATP gated mechanism of neuronal death control. By degrading endogenous extracellular ATP or blocking the P2X7 ATP receptors we found that endogenous extracellular ATP triggers the death of retinal cholinergic neurons during normal development. ATP-induced death eliminates cholinergic cells too close to one another, thereby controlling the total number, the local density and the regular spacing of these neurons.
Distinct and sequential tissue-specific activities of the LIM-class homeobox geneLim1for tubular morphogenesis during kidney development
Authors: Kobayashi Akio , Kwan Kin-Ming , Carroll Thomas J. , McMahon Andrew P. , Mendelsohn Cathy L. , Behringer Richard R.
Published: June 2005

Kidney organogenesis requires the morphogenesis of epithelial tubules. Inductive interactions between the branching ureteric buds and the metanephric mesenchyme lead to mesenchyme-to-epithelium transitions and tubular morphogenesis to form nephrons, the functional units of the kidney. The LIM-class homeobox gene Lim1 is expressed in the intermediate mesoderm, nephric duct, mesonephric tubules, ureteric bud, pretubular aggregates and their derivatives. Lim1-null mice lack kidneys because of a failure of nephric duct formation, precluding studies of the role of Lim1 at later stages of kidney development. Here, we show that Lim1 functions in distinct tissue compartments of the developing metanephros for both proper development of the ureteric buds and the patterning of renal vesicles for nephron formation. These observations suggest that Lim1 has essential roles in multiple steps of epithelial tubular morphogenesis during kidney organogenesis. We also demonstrate that the nephric duct is essential for the elongation and maintenance of the adjacent Müllerian duct, the anlage of the female reproductive tract.
Distinct roles for Mind bomb, Neuralized and Epsin in mediating DSL endocytosis and signaling inDrosophila
Authors: Wang Weidong , Struhl Gary
Published: June 2005

Ligands of the Delta/Serrate/Lag2 (DSL) family must normally be endocytosed in signal-sending cells to activate Notch in signal-receiving cells. DSL internalization and signaling are promoted in zebrafish and Drosophila, respectively, by the ubiquitin ligases Mind bomb (Mib)and Neuralized (Neur). DSL signaling activity also depends on Epsin, a conserved endocytic adaptor thought to target mono-ubiquitinated membrane proteins for internalization. Here, we present evidence that the Drosophila ortholog of Mib (Dmib) is required for ubiquitination and signaling activity of DSL ligands in cells that normally do not express Neur,and can be functionally replaced by ectopically expressed Neur. Furthermore,we show that both Dmib and Epsin are required in these cells for some of the endocytic events that internalize DSL ligands, and that the two Drosophila DSL ligands Delta and Serrate differ in their utilization of these Dmib- and Epsin-dependent pathways: most Serrate is endocytosed via the actions of Dmib and Epsin, whereas most Delta enters by other pathways. Nevertheless, only those Serrate and Delta proteins that are internalized via the action of Dmib and Epsin can signal. These results support and extend our previous proposal that mono-ubiquitination of DSL ligands allows them to gain access to a select, Epsin-dependent, endocytic pathway that they must normally enter to activate Notch.
TheCaenorhabditis elegans spe-38gene encodes a novel four-pass integral membrane protein required for sperm function at fertilization
Authors: Chatterjee Indrani , Richmond Alissa , Putiri Emily , Shakes Diane C. , Singson Andrew
Published: June 2005

A mutation in the Caenorhabditis elegans spe-38 gene results in a sperm-specific fertility defect. spe-38 sperm are indistinguishable from wild-type sperm with regards to their morphology, motility and migratory behavior. spe-38 sperm make close contact with oocytes but fail to fertilize them. spe-38 sperm can also stimulate ovulation and engage in sperm competition. The spe-38 gene is predicted to encode a novel four-pass (tetraspan) integral membrane protein. Structurally similar tetraspan molecules have been implicated in processes such as gamete adhesion/fusion in mammals, membrane adhesion/fusion during yeast mating, and the formation/function of tight-junctions in metazoa. In antibody localization experiments, SPE-38 was found to concentrate on the pseudopod of mature sperm,consistent with it playing a direct role in gamete interactions.
Dual regulation and redundant function of two eye-specific enhancers of theDrosophilaretinal determination genedachshund
Authors: Pappu Kartik S. , Ostrin Edwin J. , Middlebrooks Brooke W. , Sili Beril Tavsanli , Chen Rui , Atkins Mardelle R. , Gibbs Richard , Mardon Graeme
Published: June 2005

Drosophila eye development is controlled by a conserved network of retinal determination (RD) genes. The RD genes encode nuclear proteins that form complexes and function in concert with extracellular signal-regulated transcription factors. Identification of the genomic regulatory elements that govern the eye-specific expression of the RD genes will allow us to better understand how spatial and temporal control of gene expression occurs during early eye development. We compared conserved non-coding sequences (CNCSs)between five Drosophilids along the ∼40 kb genomic locus of the RD gene dachshund (dac). Our analysis uncovers two separate eye enhancers in intron eight and the 3′ non-coding regions of the dac locus defined by clusters of highly conserved sequences. Loss-and gain-of-function analyses suggest that the 3′ eye enhancer is synergistically activated by a combination of eya, so and dpp signaling, and only indirectly activated by ey, whereas the 5′ eye enhancer is primarily regulated by ey, acting in concert with eya and so. Disrupting conserved So-binding sites in the 3′ eye enhancer prevents reporter expression in vivo. Our results suggest that the two eye enhancers act redundantly and in concert with each other to integrate distinct upstream inputs and direct the eye-specific expression of dac.
The circuitry of a master switch: Myod and the regulation of skeletal muscle gene transcription
Authors: Tapscott Stephen J.
Published: June 2005

The expression of Myod is sufficient to convert a fibroblast to a skeletal muscle cell, and, as such, is a model system in developmental biology for studying how a single initiating event can orchestrate a highly complex and predictable response. Recent findings indicate that Myod functions in an instructive chromatin context and directly regulates genes that are expressed throughout the myogenic program, achieving promoter-specific regulation of its own binding and activity through a feed-forward mechanism. These studies are beginning to merge our understanding of how lineage-specific information is encoded in chromatin with how master regulatory factors drive programs of cell differentiation.
Developmentally and environmentally regulated expression of gamone 1: the trigger molecule for sexual reproduction inBlepharisma japonicum
Authors: Sugiura Mayumi , Kawahara Seiko , Iio Hideo , Harumoto Terue
Published: June 2005

Sexual reproduction (conjugation) in protozoan ciliates is induced by specific cell-cell interactions between cells of complementary mating types. The ancestral ciliate Blepharisma japonicum has two mating types, I and II. The substances that act as signaling molecules in this extracellular interaction for conjugation are called gamones. The glycoprotein gamone 1, produced by mating type I cells, is a key factor that triggers this interaction. We have previously isolated gamone 1 and determined its complete amino acid sequence. To elucidate the mechanism of initiation of conjugation in ciliates, we investigated the transcription of the gamone 1 gene and found that it is controlled by various internal and external factors. The gamone 1 gene transcript appeared specifically when sexually mature mating type I cells were starved. It was not detected in immature cells, mating type II cells or proliferating cells. The level of transcription was markedly increased in type I cells when they were stimulated with gamone 2, which is secreted by type II cells. This is the first report that the transcription of gamone genes in ciliates is strictly regulated by developmental and environmental factors. This study suggests that the onset of transcription of gamone 1 is linked to the switching mechanism that converts mitotically proliferating cells to differentiated preconjugants, the mechanism of differentiation from immature to mature cells in clonal development, and the mechanism that ensures mating type-specific gene silencing.
Laminin-6 assembles into multimolecular fibrillar complexes with perlecan and participates in mechanical-signal transduction via a dystroglycan-dependent, integrin-independent mechanism
Authors: Jones Jonathan C. R. , Lane Kimberly , Hopkinson Susan B. , Lecuona Emilia , Geiger Robert C. , Dean David A. , Correa-Meyer Eduardo , Gonzales Meredith , Campbell Kevin , Sznajder Jacob I. , Budinger Scott
Published: June 2005

Mechanical ventilation is a valuable treatment regimen for respiratory failure. However, mechanical ventilation (especially with high tidal volumes) is implicated in the initiation and/or exacerbation of lung injury. Hence, it is important to understand how the cells that line the inner surface of the lung [alveolar epithelial cells (AECs)] sense cyclic stretching. Here, we tested the hypothesis that matrix molecules, via their interaction with surface receptors, transduce mechanical signals in AECs. We first determined that rat AECs secrete an extracellular matrix (ECM) rich in anastamosing fibers composed of the α3 laminin subunit, complexed with β1 and γ1 laminin subunits (i.e. laminin-6), and perlecan by a combination of immunofluorescence microscopy and immunoblotting analyses. The fibrous network exhibits isotropic expansion when exposed to cyclic stretching (30 cycles per minute, 10% strain). Moreover, this same stretching regimen activates mitogen-activated-protein kinase (MAPK) in AECs. Stretch-induced MAPK activation is not inhibited in AECs treated with antagonists to α3 or β1 integrin. However, MAPK activation is significantly reduced in cells treated with function-inhibiting antibodies against the α3 laminin subunit and dystroglycan, and when dystroglycan is knocked down in AECs using short hairpin RNA. In summary, our results support a novel mechanism by which laminin-6, via interaction with dystroglycan, transduces a mechanical signal initiated by stretching that subsequently activates the MAPK pathway in rat AECs. These results are the first to indicate a function for laminin-6. They also provide novel insight into the role of the pericellular environment in dictating the response of epithelial cells to mechanical stimulation and have broad implications for the pathophysiology of lung injury.
Regulation of neural progenitor proliferation and survival by β1 integrins
Authors: Leone Dino P. , Relvas João B. , Campos Lia S. , Hemmi Silvio , Brakebusch Cord , Fässler Reinhard , ffrench-Constant Charles , Suter Ueli
Published: June 2005

Neural stem cells give rise to undifferentiated nestin-positive progenitors that undergo extensive cell division before differentiating into neuronal and glial cells. The precise control of this process is likely to be, at least in part, controlled by instructive cues originating from the extracellular environment. Some of these cues are interpreted by the integrin family of extracellular matrix receptors. Using neurosphere cell cultures as a model system, we show that β1-integrin signalling plays a crucial role in the regulation of progenitor cell proliferation, survival and migration. Following conditional genetic ablation of the β1-integrin allele, and consequent loss of β1-integrin cell surface protein, mutant nestin-positive progenitor cells proliferate less and die in higher numbers than their wild-type counterparts. Mutant progenitor cell migration on different ECM substrates is also impaired. These effects can be partially compensated by the addition of exogenous growth factors. Thus, β1-integrin signalling and growth factor signalling tightly interact to control the number and migratory capacity of nestin-positive progenitor cells.
Klp67A destabilises pre-anaphase microtubules but subsequently is required to stabilise the central spindle
Authors: Gatt Melanie K. , Savoian Matthew S. , Riparbelli Maria G. , Massarelli Chiara , Callaini Giuliano , Glover David M.
Published: June 2005

Klp67A is a member of the Kip3 subfamily of microtubule destabilising kinesins, the loss of which results in abnormally long and stable pre-anaphase microtubules. Here we examine its role during cytokinesis in Drosophila primary spermatocytes that require the coordinated interaction of an interior and peripheral set of central spindle microtubules. In mutants anaphase B spindles elongated with normal kinetics but bent towards the cortex. Both peripheral and interior spindle microtubules then formed diminished bundles of abnormally positioned central spindle microtubules associated with the pavarotti-KLP and KLP3A motor proteins. The minus ends of these were poorly aligned as revealed by Asp protein localisation. Furrows always initiated at the sites of central spindle bundles but could be unilateral or nonequatorially positioned. Ectopic furrows were stimulated by the interior central spindle and formed only after this structure buckled and contacted the cortex. Furrows often halted and regressed as they could not be sustained by the central spindles that became increasing unstable over time and often completely degraded. Consistent with this, actin and anillin failed to form homogenous bands. Thus, the Klp67A microtubule catastrophe factor is required for cytokinesis by regulating both the formation and stability of the central spindle.
Carbon–Carbon Bond Cleavage and Selective Transformation of Zirconacycles
Authors: Takahashi Tamotsu , Kotora Martin , Hara Ryuichiro , Xi Zhenfeng
Published: June 2005

This account describes recent development in carbon–carbon bond cleavage reactions and selective transformation of 5-membered zirconacycles, including zirconacyclopentanes, zirconacyclopentenes, and zirconacyclopentadienes. These zirconacycles can be prepared by coupling of unsaturated compounds such as alkenes and/or alkynes, but the zirconacycles also undergo β,β′-C–C bond cleavage, which has been further applied to organic transformation reactions. Combination of the β,β′-C–C bond cleavage and the C–C bond formation on zirconocene provided a highly selective and novel transformation. Vinylzirconation of alkynes, regioselective allylzirconation of alkynes, and coupling of alkynes with nitriles or ketones were achieved by this method. Zirconacyclopentadienes prepared symmetrically or unsymmetrically were converted into naphthalene, diene, and benzene derivatives. Preparation of benzene derivatives from three different alkynes was performed by combination of C–C bond cleavage and C–C bond formation on zirconocene in one-pot in high yield with excellent selectivity.
Pd(II)- and Pt(II)-Linked Tetranuclear Complexes as Assembly Units for Higher Ordered Structures
Authors: Aoyagi Masaru , Biradha Kumar , Fujita Makoto
Published: June 2005

The formation of ···Pt(II)···Br–Pt(IV)··· mixed-valence complexes was utilized for the assembly of square compounds, [(en)M(4,4′-bpy)]4(NO3)8 (1·(NO3)8; a: M = Pt(II), b: M = Pd(II), 4,4′-bpy = 4,4′-bipyridine), into higher ordered infinite complexes. The reaction of 18+ with cationic Pt(IV) complex, [PtBr2(en)2]2+ (22+), afforded a 1 : 3 complex 1a·(2)314+. Crystallographic analysis of this complex showed that two moieties of 22+ bridged at the cis corner of 1a8+ making a stair-like infinite network, whereas another moiety of 22+ was accommodated in the cavity of 1a8+. On the other hand, complexation of 1b with anionic Pt(IV) complex, PtX62− (32−; a: X = Cl, b: X = Br), afforded a 1 : 4 complex 1·(3)4. UV-vis observations suggested the formation of a linear tube structure, in which each corner of 18+ is bridged by the linear X–Pt–X motif of 32−.
Characterization of CO- and H2-Adsorbed Au6Pt-Phosphine Clusters Supported on SiO2 by EXAFS, TPD, and FTIR
Authors: Yuan Youzhu , Asakura Kiyotaka , Wan Huilin , Tsai Khirui , Iwasawa Yasuhiro
Published: June 2005

The adsorption of CO and H2 on a SiO2-supported Au6Pt cluster [(AuPPh3)6Pt(PPh3)](NO3)2 (1) has been studied by means of FTIR, TPD, and EXAFS. CO adsorbed on 1/SiO2 to form a CO-adduct complex, which exhibited an IR band at ca. 1972 cm−1. The adsorbed CO was desorbed below 403 K, showing a peak maximum at 363 K in TPD. There was little change in the coordination number of Pt–Au in Pt L3-edge EXAFS upon CO adsorption, but the coordination number of Au–Au in Au L3-edge EXAFS slightly increased and the peak ascribed to Pt–(Au)–P in the Pt L3-edge EXAFS Fourier transform remarkably increased. The increase in the intensity of the Pt–(Au)–P peak was interpreted by the multiple scattering effect owing to the change of Pt–Au–P bond angle. The original EXAFS oscillations at both Pt and Au L3-edges were regenerated after evacuation of the CO-adsorbed sample for 2 h at 353 K, indicating the recovery of the original cluster structure. This is entirely different from the case of the cluster 1 in solution, where the cluster framework is fragmented by the CO adsorption-desorption process. The adsorption of H2 on 1/SiO2 was totally reversible at room temperature; it provided no contribution to the EXAFS oscillation.
Mixed-Valence Ammonium Trivanadate with a Tunnel Structure Prepared by Pyrolysis of Polyoxovanadate
Authors: Naruke Haruo , Yamase Toshihiro
Published: June 2005

The pyrolysis of a polyoxovanadate solid, (NH4)12[V18O42(H2O)]·nH2O (n ≈ 11), at 300 °C in an Ar+NH3 atmosphere gave a mixed-valence vanadium oxide, (NH4)xV3O7 (x ≈ 0.6), isostructural with Cs0.37V3O7. The crystal structure of (NH4)xV3O7 was refined by the Rietveld method (hexagonal, P63/m, a = 9.8436(6), c = 3.6165(1) Å, V = 303.47(3) Å3, Z = 2). (NH4)xV3O7 comprises edge- and corner-sharing VIV/VO5 square-pyramids with an approximate ratio of VIV : VV ≈ 0.49 : 0.51, to form a columnar cavity along the c-axis, in which ammonium N atoms are hydrogen-bonded to apical O atoms of the VIV/VO5 square-pyramids. A reflux of the (NH4)xV3O7 powder in a 0.6 M LiOH/2-methoxyethanol solution brought about Li-insertion into the columnar cavity without any structural change in the {V3O7} framework.
Regioselective Synthesis of Nitrones by Decarboxylative Oxidation of N-Alkyl-α-amino Acids and Application to the Synthesis of 1-Azabicyclic Alkaloids
Authors: Ohtake Hiroaki , Imada Yasushi , Murahashi Shun-Ichi
Published: June 2005

Tungstate-catalyzed oxidation of N-alkyl-α-amino acids with 30% H2O2 solution under phase-transfer conditions gives nitrones regioselectively in good yields. Using this method, stereodivergent synthesis of (R)- and (S)-4-(t-butyldimethylsilyloxy)-1-pyrroline N-oxides ((R)-17a and (S)-17a) was achieved. In addition, (R)- and (S)-3-(t-butyldimethylsilyloxy)-1-pyrroline N-oxides ((R)-45 and (S)-45) were prepared by catalytic oxidation of the corresponding chiral pyrrolidines in a regioselective manner. These chiral cyclic nitrones, 17 and 45 are versatile intermediates for the synthesis of optically active nitrogen heterocycles, since stereoselective additions of carbon nucleophiles to these chiral nitrones can be readily performed. Typically, ZnI2-mediated addition of ketene t-butyldimethylsilyl methyl acetal (29a) to (R)-17a gave the cis-adduct, methyl (2R,4R)-[1,4-bis(t-butyldimethylsilyloxy)pyrrolidin-2-yl]acetate (cis-30). In contrast, the addition of lithium acetylides 34 to the nitrone (R)-17a gave the trans-adducts, (2S,4R)-2-(1-alkynyl)-4-(t-butyldimethylsilyloxy)-1-hydroxypyrrolidines trans-35. These adducts are useful intermediates for syntheses of the nitrogen heterocycles (3R,5R)-1-aza-3-hydroxybicyclo[3.3.0]octane (37) and (6R,8R)-1-aza-8-hydroxybicyclo[4.3.0]nonane (38), respectively. The ZnI2-mediated addition of ketene silyl acetal 29a to the nitrone (R)-45 gave methyl (2S,3R)-[1,3-bis(t-butyldimethylsilyloxy)pyrrolidin-2-yl]acetate (trans-50a), which was used for asymmetric synthesis of the Geissman–Waiss lactone ((−)-49).
Liquid Crystallinity of 2-Acyl-7-[p-(alkoxy)benzylideneamino]fluorenes
Authors: Takabayashi Yutaka , Yusa Takeshi , Minabe Masahiro , Kimura Takao , Tsubota Motohiro
Published: June 2005

The liquid crystallinity of the title compounds was studied in order to design a stable liquid crystal used at low temperature. The Schiff base derived from 1- or 3-fluoreneamine scarcely shows liquid crystallinity. The propionyl group is effective for lowering the melting point of the mesophase compared to the acetyl group in a series of the title substances. The liquid crystallinity of the title compounds was compared with that of biphenyl homologues. A mesophase of the title substances was observed over a wider range of temperatures than in the case of biphenyl derivatives in a series of propionyl groups.
Benzylation of Alcoholic Hydroxyl Groups with Benzyl Mesylate by Using a Catalytic Amount of Lithium Tetrakis(pentafluorophenyl)borate in the Coexistence of Lithium Triflate and Magnesium Oxide
Authors: Nakano Masakazu , Matsuo Jun-ichi , Mukaiyama Teruaki
Published: June 2005

Several alcohols possessing alkali-labile substituents such as halogen, ester and ketone were effectively benzylated with benzyl mesylate by using a catalytic amount of lithium tetrakis(pentafluorophenyl)borate [LiB(C6F5)4] in the coexistence of lithium triflate (LiOTf) and magnesium oxide (MgO) to afford the corresponding benzyl ethers in good to excellent yields.
Two-Dimensional Molecular Imprinting: Binding of Sugars to Boronic Acid Functionalized, Polymerized Langmuir–Blodgett Films
Authors: Miyahara Takashi , Kurihara Kazue
Published: June 2005

A molecular imprinted surface was prepared by polymerizing the Langmuir film of a mixture of two polymerizable amphiphiles, one of which has a boronic acid group as a binding site for a template molecule, 4-nitrophenyl α-d-mannopyranoside (3), dissolved in the aqueous subphase. The imprinted surface exhibited an improved affinity (35%) for the template molecule 3 in 2-butanone compared with the non-imprinted surface.
Single Water Molecule Recognition: A 1:1 Complex of Crownophane with Water by Pseudo-tetrahedral Hydrogen Bond Formation
Authors: Hiratani Kazuhisa , Goto Midori , Nagawa Yoshinobu , Kasuga Kazuyuki , Fujiwara Kyoko
Published: June 2005

A 22-membered crownophane prepared via the “Tandem Claisen Rearrangement” was found to form stable 1:1 complex with water, which is incorporated into the cavity by pseudo-tetrahedral hydrogen bond formation and observed by DSC, TGA, and X-ray structural analysis.
In situ Observation of Molecular Swapping in a Crystal by X-ray Analysis
Authors: Kawano Masaki , Sano Tomokatsu , Abe Jiro , Ohashi Yuji
Published: June 2005

X-ray diffraction analysis elucidated that a pair of hexaarylbiimidazoles was transformed to a complex composed of two lophyl radicals and a piezodimer on irradiation at low temperatures. The piezodimer, the existence of which has been assumed spectroscopically as an unstable isomer, was produced via molecular swapping of two photo-induced lophyl radicals with drastic conformational change. The black crystal reverted to the original structure on warming to 25 °C.
Sequence-Selective RNA Scission by Non-Covalent Combination of Acridine-Tethered DNA and Lanthanide(III) Ion
Authors: Kuzuya Akinori , Komiyama Makoto
Published: June 2005

Binary non-covalent systems for site-selective RNA scission are prepared from Lu(III) ion and a DNA bearing an acridine in the internal position. On the formation of DNA/RNA hetero-duplex, the target phosphodiester linkage is activated and preferentially hydrolyzed.
Interpenetrating Inorganic–Organic Hybrid Gels: Preparation of Hybrid and Replica Gels
Authors: Suzuki Kazuya , Yumura Takeshi , Tanaka Yuko , Serizawa Takeshi , Akashi Mitsuru
Published: June 2005

An organic–inorganic hybrid gel was prepared by gelation of organic monomer or polymer solution in pores of a silica matrix. Furthermore, a replica organic gel was obtained from the organic–inorganic hybrid gel by treating the hybrid with aqueous hydrofluoric acid solution. The silica matrix of the hybrid gel was similarly dissolved using aqueous hydrofluoric acid solution, leaving the organic gel matrix.
Photoreaction of o-Acylstyrenes: Formation of Benzo-Fused 8-Oxabicyclo[3.2.1]octanes
Authors: Oda Kazuaki , Nakagami Rikiji , Nishizono Naozumi , Machida Minoru
Published: June 2005

Irradiation of o-acylstyrenes affords a pair of stereoisomers of photodimerized benzo-fused oxygen-bridged compounds, 8-oxabicyclo[3.2.1]octane derivatives.
Photoresponsive Dendrimers: Syntheses and Characterizations of Anthracenes Bearing Dendritic Substituents
Authors: Takaguchi Yutaka , Tajima Tomoyuki , Ohta Kazuchika , Motoyoshiya Jiro , Aoyama Hiromu
Published: June 2005

A new photoreactive anthracenyl dendron undergoes a reversible photocyclization to form a dendrimer.
Preparation of C60 Microcrystals Using High-Temperature and High-Pressure Liquid Crystallization Method
Authors: Kasai Hitoshi , Okazaki Susumu , Hanada Takeshi , Okada Shuji , Oikawa Hidetoshi , Adschiri Tadafumi , Arai Kunio , Yase Kiyoshi , Nakanishi Hachiro
Published: June 2005

Using reprecipitation technique from high temperature and high pressure liquid, C60 microcrystals with size of about 40 nm and narrow size distribution could be fabricated in the dispersion liquid. And it was found that the optical properties of C60 microcrystals were also dependent on crystal size in a similar manner as the other π-conjugated organic microcrystals.
Ortho-[2,3]-Wittig Rearrangement of Benzyl Propargyl Ethers: Striking Preference over the Competing [1,2]-Wittig Shift
Authors: Tomooka Katsuhiko , Harada Manabu , Hanji Takayuki , Nakai Takeshi
Published: June 2005

Treatment of benzyl γ-(trimethylsilyl)propargyl ether with n-BuLi is shown to afford the rarely precedent ortho-[2,3]-Wittig product in remarkable preference to the [1,2]-Wittig product. The factors governing the periselectivity in this type of carbanion rearrangement are discussed.
trans-3,4-Dihydroxy-1-selenolane Oxide: A New Reagent for Rapid and Quantitative Formation of Disulfide Bonds in Polypeptides
Authors: Iwaoka Michio , Tomoda Shuji
Published: June 2005

The title compound was found to be a powerful quantitative reagent for the formation of the disulfide bonds in polypeptides in a wide range of pH in the oxidative regeneration experiments of bovine pancreatic ribonuclease A (Rnase A).
Controlled Detachment of Immobilized Liposomes on Polymer Gel Support
Authors: Khaleque Md Abdul , Oho Takahiro , Okumura Yukihisa , Mitani Michiharu
Published: June 2005

Immobilization of small liposomes on polymer gel beads and controlled detachment of the liposomes from the support was described. Liposomes were immobilized on the gel with hydrophobic anchors that contained disulfide linkage. The liposomes were then detached by reductive cleavage of the linkage with dithiothreitol. The major part of the fluorescein-conjugated dextran encapsulated in the liposomes was retained throughout the immobilization-detachment process.
Nickel-Catalyzed Coupling Reaction of Zirconacyclopentadienes with Two Alkynyl Halides: Formation of Multi-Substituted Arylalkynes
Authors: Wang Hui , Tsai Fu-Yu , Takahashi Tamotsu
Published: June 2005

Zirconacyclopentadienes reacted with two equiv of alkynyl halides in the presence of a catalytic amount of NiCl2(PPh3)2 to afford multi-substituted arylalkynes.
Discrimination of Thiolate Group in l-Cysteinate and Glutathionate by Axial Coordination Site of Five-Coordinate Trigonal-Bipyramidal Palladium(II) Complex with Tris(2-(diphenylphosphino)ethyl)phosphine
Authors: Aizawa Sen-ichi , Okada Motofumi , Kobayashi Ken-ichi , Yamada Shinkichi , Nakamura Motoshi
Published: June 2005

Five-coordinate trigonal-bipyramidal palladium(II) l-cysteinato and glutathionato complexes with tris(2-(diphenylphosphino)ethyl)phosphine have been prepared. The high selectivity for the thiolato sulfur atom in the axial position has been confirmed and was applied to separation of l-cysteine from the other amino acids and selective determination of the reduced form of glutathione.
Hydrogenation of Silyl-Substituted Alkynes Using Diimide: Application to the Synthesis of Saturated Sila-Macrocycles
Authors: Kwon Eunsang , Sakamoto Kenkichi , Kabuto Chizuko , Kira Mitsuo
Published: June 2005

The hydrogenation of bistrimethylsilylactylene, bis(trimethylsilyl)-1,3-diynes, and related silylalkynes giving the corresponding saturated compounds were achieved by using diimide prepared in situ from p-toluenesulfonyl hydrazide in diglyme. The present method was applicable to the synthesis of saturated 12- and 18-membered oligosilacycloalkanes.
Oxo- and Alkoxo-Bridged Dimeric Molybdenum(III) Ethylenediamine Complexes
Authors: Kiyoda Shunji , Akashi Haruo , Ichimura Akio , Shibahara Takashi
Published: June 2005

Oxo- and alkoxo-bridged dimeric molybdenum(III) ethylenediamine complexes, [Mo2(µ-O)(µ-R)(en)4]3+ (R = Ome (3); R = Oet (4)) were synthesized from the mononuclear complex [MoCl3(thf)3], and were characterized structurally, spectroscopically, and electrochemically, where the methoxy- and ethoxy-bridges were introduced by using methanol and ethanol as the solvent, respectively. The electronic spectra of 3 and 4 have characteristic peaks in visible and near infrared region, and the addition of acid causes a dramatic decrease of the peak heights.
A Robust Two-Dimensional Hydrogen-Bonded Network. Reversible Guest Adsorption/Desorption without a Phase Change
Authors: Tanaka Toshihiro , Endo Ken , Aoyama Yasuhiro
Published: June 2005

9-(3,5-Dihydroxyphenyl)acridine (3) forms a 1:1 benzene adduct 3·(benzene) having a novel O–H···O–H···N hydrogen-bonded 2D network. Partial (50%) guest desorption occurs in a reversible manner without undergoing a phase change.
Synthesis and Nonlinear Optical Properties of p-(Dimethylamino)benzylidene Dyes Containing Different Acceptors
Authors: Zheng Qingdong , Yao Zuguang , Cheng Jiqi , Shen Yaochun , Lu Zuhong
Published: June 2005

Several p-(dimethylamino)benzylidene dyes were synthesized and their evaluation of β using Hyper-Rayleigh Scattering (HRS) technique was reported. The results show that these dyes have enhanced second-order hyperpolarizabilities.
Novel Synthesis of Polyaniline Using Iron(III) Catalyst and Ozone
Authors: Toshima Naoki , Yan Hu , Kajita Masashi , Honda Yasuyuki , Ohno Naonori
Published: June 2005

Polymerization of aniline using iron(III) and ozone as a catalyst and an oxidant, respectively, provided polyaniline with an emeraldine form based on IR and UV–vis spectroscopic data, although influence of the reaction temperature upon the molecular weight of the polyaniline was different from the case of ammonium peroxodisulfate. Preliminary results of experiments have revealed that polyaniline is produced catalytically in terms of iron(III). Morphology of polyaniline produced significantly influenced electrical conductivity of the polyaniline pellet.
Room Temperature Molten Salts Based on Trialkylsulfonium Cations and Bis(trifluoromethylsulfonyl)imide
Authors: Matsumoto Hajime , Matsuda Toshihiko , Miyazaki Yoshinori
Published: June 2005

Symmetric and aliphatic trialkylsulfonium cation form room temperature molten salts (RTMS) with bis(trifluoromethylsulfonyl)imide (TFSI). In particular RTMS based on triethylsulfonium shows low melting point (−35 °C) and the lowest viscosity (30 mPs at 25 °C) of all the TFSI based RTMS as reported so far. The conductivity of 7.1 mS cm−1 at 25 °C is the highest of all the non-chloroaluminate RTMS based on aliphatic onium cations.
Structural insights into SRP RNA: An induced fit mechanism for SRP assembly
Authors: HAINZL TOBIAS , HUANG SHENGHUA , SAUER-ERIKSSON A. ELISABETH
Published: June 2005

Proper assembly of large protein–RNA complexes requires sequential binding of the proteins to the RNA. The signal recognition particle (SRP) is a multiprotein–RNA complex responsible for the cotranslational targeting of proteins to biological membranes. Here we describe the crystal structure at 2.6-Å resolution of the S-domain of SRP RNA from the archeon Methanococcus jannaschii. Comparison of this structure with the SRP19-bound form reveals the nature of the SRP19-induced conformational changes, which promote subsequent SRP54 attachment. These structural changes are initiated at the SRP19 binding site and transmitted through helix 6 to looped-out adenosines, which form tertiary RNA interaction with helix 8. Displacement of these adenosines enforces a conformational change of the asymmetric loop structure in helix 8. In free RNA, the three unpaired bases A195, C196, and C197 are directed toward the helical axis, whereas upon SRP19 binding the loop backbone inverts and the bases are splayed out in a conformation that resembles the SRP54-bound form. Nucleotides adjacent to the bulged nucleotides seem to be particularly important in the regulation of this loop transition. Binding of SRP19 to 7S RNA reveals an elegant mechanism of how protein-induced changes are directed through an RNA molecule and may relate to those regulating the assembly of other RNPs.
A kissing-loop interaction in a hammerhead viroid RNA critical for its in vitro folding and in vivo viability
Authors: GAGO SELMA , DE LA PEÑA MARCOS , FLORES RICARDO
Published: June 2005

Chrysanthemum chlorotic mottle viroid (CChMVd) RNA (398–401 nucleotides) can form hammerhead ribozymes that play a functional role in its replication through a rolling-circle mechanism. In contrast to most other viroids, which adopt rod-like or quasi-rod-like secondary structures of minimal free energy, the computer-predicted conformations of CChMVd and Peach latent mosaic viroid (PLMVd) RNAs are branched. Moreover, the covariations found in a number of natural CChMVd variants support that the same or a closely related conformation exists in vivo. Here we report that the CChMVd natural variability also supports that the branched conformation is additionally stabilized by a kissing-loop interaction resembling another one proposed in PLMVd from in vitro assays. Moreover, site-directed mutagenesis combined with bioassays and progeny analysis showed that: (1) single CChMVd mutants affecting the kissing loops had low or no infectivity at all, whereas infectivity was recovered in double mutants restoring the interaction; (2) mutations affecting the structure of the regions adjacent to the kissing loops reverted to wild type or led to rearranged stems, also supporting their interaction; and (3) the interchange between 4 nucleotides of each of the two kissing loops generated a viable CChMVd variant with eight mutations. PAGE analysis under denaturing and nondenaturing conditions revealed that the kissing-loop interaction determines proper in vitro folding of CChMVd RNA. Preservation of a similar kissing-loop interaction in two hammerhead viroids with an overall low sequence similarity suggests that it facilitates in vivo the adoption and stabilization of a compact folding critical for viroid viability.