Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog.

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Cruz, Luisa F; Parker, Jennifer K; Cobine, Paul A; De La Fuente, Leonardo

2014-12-01

The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Multiscale modeling of bacterial colonies: how pili mediate the dynamics of single cells and cellular aggregates

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Pönisch, Wolfram; Weber, Christoph A.; Juckeland, Guido; Biais, Nicolas; Zaburdaev, Vasily

2017-01-01

Neisseria gonorrhoeae is the causative agent of one of the most common sexually transmitted diseases, gonorrhea. Over the past two decades there has been an alarming increase of reported gonorrhea cases where the bacteria were resistant to the most commonly used antibiotics thus prompting for alternative antimicrobial treatment strategies. The crucial step in this and many other bacterial infections is the formation of microcolonies, agglomerates consisting of up to several thousands of cells. The attachment and motility of cells on solid substrates as well as the cell-cell interactions are primarily mediated by type IV pili, long polymeric filaments protruding from the surface of cells. While the crucial role of pili in the assembly of microcolonies has been well recognized, the exact mechanisms of how they govern the formation and dynamics of microcolonies are still poorly understood. Here, we present a computational model of individual cells with explicit pili dynamics, force generation and pili-pili interactions. We employ the model to study a wide range of biological processes, such as the motility of individual cells on a surface, the heterogeneous cell motility within the large cell aggregates, and the merging dynamics and the self-assembly of microcolonies. The results of numerical simulations highlight the central role of pili generated forces in the formation of bacterial colonies and are in agreement with the available experimental observations. The model can quantify the behavior of multicellular bacterial colonies on biologically relevant temporal and spatial scales and can be easily adjusted to include the geometry and pili characteristics of various bacterial species. Ultimately, the combination of the microbiological experimental approach with the in silico model of bacterial colonies might provide new qualitative and quantitative insights on the development of bacterial infections and thus pave the way to new antimicrobial treatments.

Pili and flagella biology, structure, and biotechnological applications.

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Van Gerven, Nani; Waksman, Gabriel; Remaut, Han

2011-01-01

Bacteria and Archaea expose on their outer surfaces a variety of thread-like proteinaceous organelles with which they interact with their environments. These structures are repetitive assemblies of covalently or non-covalently linked protein subunits, organized into filamentous polymers known as pili ("hair"), flagella ("whips") or injectisomes ("needles"). They serve different roles in cell motility, adhesion and host invasion, protein and DNA secretion and uptake, conductance, or cellular encapsulation. Here we describe the functional, morphological and genetic diversity of these bacterial filamentous protein structures. The organized, multi-copy build-up and/or the natural function of pili and flagella have lead to their biotechnological application as display and secretion tools, as therapeutic targets or as molecular motors. We review the documented and potential technological exploitation of bacterial surface filaments in light of their structural and functional traits. Copyright © 2011 Elsevier Inc. All rights reserved.

Type IV pili in Francisella – A virulence trait in an intracellular pathogen

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Emelie eNäslund Salomonsson

2011-02-01

Full Text Available Francisella tularensis is a highly virulent intracellular human pathogen that is capable of rapid proliferation in the infected host. Mutants affected in intracellular survival and growth are highly attenuated which highlights the importance of the intracellular phase of the infection. Genomic analysis has revealed that Francisella encodes all genes required for expression of functional type IV pili (Tfp, and in this focused review we summarise recent findings regarding this system in the pathogenesis of tularemia. Tfp are dynamic adhesive structures that have been identified as major virulence determinants in several human pathogens, but it is not obvious what role these structures could have in an intracellular pathogen like Francisella. In the human pathogenic strains, genes required for secretion and assembly of Tfp and one pilin, PilA, have shown to be required for full virulence. Importantly, specific genetic differences have been identified between the different Francisella subspecies where in the most pathogenic type A variants all genes are intact while several Tfp genes are pseudogenes in the less pathogenic type B strains. This suggests that there has been a selection for expression of Tfp with different properties in the different subspecies. There is also a possibility that the genetic differences reflect adaption to different environmental niches of the subspecies and plays a role in transmission of tularemia. This is also in line with recent findings where Tfp pilins are found to be glycosylated which could reflect a role for Tfp in the environment to promote survival and transmission. We are still far from understanding the role of Tfp in virulence and transmission of tularemia, but with the genomic information and genetic tools available we are in a good position to address these issues in the future.

A structural basis for sustained bacterial adhesion: biomechanical properties of CFA/I pili.

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Andersson, Magnus; Björnham, Oscar; Svantesson, Mats; Badahdah, Arwa; Uhlin, Bernt Eric; Bullitt, Esther

2012-02-03

Enterotoxigenic Escherichia coli (ETEC) are a major cause of diarrheal disease worldwide. Adhesion pili (or fimbriae), such as the CFA/I (colonization factor antigen I) organelles that enable ETEC to attach efficiently to the host intestinal tract epithelium, are critical virulence factors for initiation of infection. We characterized the intrinsic biomechanical properties and kinetics of individual CFA/I pili at the single-organelle level, demonstrating that weak external forces (7.5 pN) are sufficient to unwind the intact helical filament of this prototypical ETEC pilus and that it quickly regains its original structure when the force is removed. While the general relationship between exertion of force and an increase in the filament length for CFA/I pili associated with diarrheal disease is analogous to that of P pili and type 1 pili, associated with urinary tract and other infections, the biomechanical properties of these different pili differ in key quantitative details. Unique features of CFA/I pili, including the significantly lower force required for unwinding, the higher extension speed at which the pili enter a dynamic range of unwinding, and the appearance of sudden force drops during unwinding, can be attributed to morphological features of CFA/I pili including weak layer-to-layer interactions between subunits on adjacent turns of the helix and the approximately horizontal orientation of pilin subunits with respect to the filament axis. Our results indicate that ETEC CFA/I pili are flexible organelles optimized to withstand harsh motion without breaking, resulting in continued attachment to the intestinal epithelium by the pathogenic bacteria that express these pili. Copyright © 2011 Elsevier Ltd. All rights reserved.

Necessity of electrically conductive pili for methanogenesis with magnetite stimulation

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Oumei Wang

2018-03-01

Full Text Available Background Magnetite-mediated direct interspecies electron transfer (DIET between Geobacter and Methanosarcina species is increasingly being invoked to explain magnetite stimulation of methane production in anaerobic soils and sediments. Although magnetite-mediated DIET has been documented in defined co-cultures reducing fumarate or nitrate as the electron acceptor, the effects of magnetite have only been inferred in methanogenic systems. Methods Concentrations of methane and organic acid were analysed with a gas chromatograph and high-performance liquid chromatography, respectively. The concentration of HCl-extractable Fe(II was determined by the ferrozine method. The association of the defined co-cultures of G. metallireducens and M. barkeri with magnetite was observed with transmission electron micrographs. Results Magnetite stimulated ethanol metabolism and methane production in defined co-cultures of G. metallireducens and M. barkeri; however, magnetite did not promote methane production in co-cultures initiated with a culture of G. metallireducens that could not produce electrically conductive pili (e-pili, unlike the conductive carbon materials that facilitate DIET in the absence of e-pili. Transmission electron microscopy revealed that G. metallireducens and M. barkeri were closely associated when magnetite was present, as previously observed in G. metallireducens/G. sulfurreducens co-cultures. These results show that magnetite can promote DIET between Geobacter and Methanosarcina species, but not as a substitute for e-pili, and probably functions to facilitate electron transfer from the e-pili to Methanosarcina. Conclusion In summary, the e-pili are necessary for the stimulation of not only G. metallireducens/G. sulfurreducens, but also methanogenic G. metallireducens/M. barkeri co-cultures with magnetite.

Pili of oral Streptococcus sanguinis bind to fibronectin and contribute to cell adhesion.

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Okahashi, Nobuo; Nakata, Masanobu; Sakurai, Atsuo; Terao, Yutaka; Hoshino, Tomonori; Yamaguchi, Masaya; Isoda, Ryutaro; Sumitomo, Tomoko; Nakano, Kazuhiko; Kawabata, Shigetada; Ooshima, Takashi

2010-01-08

Streptococcus sanguinis is a predominant bacterium in the human oral cavity and occasionally causes infective endocarditis. We identified a unique cell surface polymeric structure named pili in this species and investigated its functions in regard to its potential virulence. Pili of S. sanguinis strain SK36 were shown to be composed of three distinctive pilus proteins (PilA, PilB, and PilC), and a pili-deficient mutant demonstrated reduced bacterial adherence to HeLa and human oral epithelial cells. PilC showed a binding ability to fibronectin, suggesting that pili are involved in colonization by this species. In addition, ATCC10556, a standard S. sanguinis strain, was unable to produce pili due to defective pilus genes, which indicates a diversity of pilus expression among various S. sanguinis strains. Copyright 2009 Elsevier Inc. All rights reserved.

Lactobacillus rhamnosus GG Outcompetes Enterococcus faecium via Mucus-Binding Pili: Evidence for a Novel and Heterospecific Probiotic Mechanism.

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Tytgat, Hanne L P; Douillard, François P; Reunanen, Justus; Rasinkangas, Pia; Hendrickx, Antoni P A; Laine, Pia K; Paulin, Lars; Satokari, Reetta; de Vos, Willem M

2016-10-01

Vancomycin-resistant enterococci (VRE) have become a major nosocomial threat. Enterococcus faecium is of special concern, as it can easily acquire new antibiotic resistances and is an excellent colonizer of the human intestinal tract. Several clinical studies have explored the potential use of beneficial bacteria to weed out opportunistic pathogens. Specifically, the widely studied Lactobacillus rhamnosus strain GG has been applied successfully in the context of VRE infections. Here, we provide new insight into the molecular mechanism underlying the effects of this model probiotic on VRE decolonization. Both clinical VRE isolates and L. rhamnosus GG express pili on their cell walls, which are the key modulators of their highly efficient colonization of the intestinal mucosa. We found that one of the VRE pilus clusters shares considerable sequence similarity with the SpaCBA-SrtC1 pilus cluster of L. rhamnosus GG. Remarkable immunological and functional similarities were discovered between the mucus-binding pili of L. rhamnosus GG and those of the clinical E. faecium strain E1165, which was characterized at the genome level. Moreover, E. faecium strain E1165 bound efficiently to mucus, which may be prevented by the presence of the mucus-binding SpaC protein or antibodies against L. rhamnosus GG or SpaC. These results present experimental support for a novel probiotic mechanism, in which the mucus-binding pili of L. rhamnosus GG prevent the binding of a potential pathogen to the host. Hence, we provide a molecular basis for the further exploitation of L. rhamnosus GG and its pilins for prophylaxis and treatment of VRE infections. Concern about vancomycin-resistant Enterococcus faecium causing nosocomial infections is rising globally. The arsenal of antibiotic strategies to treat these infections is nearly exhausted, and hence, new treatment strategies are urgently needed. Here, we provide molecular evidence to underpin reports of the successful clinical application of

The three-dimensional structure of CFA/I adhesion pili: traveler's diarrhea bacteria hang on by a spring.

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Mu, Xiang-Qi; Savarino, Stephen J; Bullitt, Esther

2008-02-22

To survive the harsh environment of a churning intestinal tract, bacteria attach to the host epithelium via thin fibers called pili (or fimbriae). Enterotoxigenic Escherichia coli bacteria expressing colonization factor antigen I (CFA/I) pili and related pili are the most common known bacterial cause of diarrheal disease, including traveler's diarrhea. CFA/I pili, assembled via the alternate chaperone pathway, are essential for binding and colonization of the small bowel by these pathogenic bacteria. Herein, we elucidate unique structural features of CFA/I pili that appear to optimize their function as bacterial tethers in the intestinal tract. Using transmission electron microscopy of negatively stained samples in combination with iterative three-dimensional helical reconstruction methods for image processing, we determined the structure of the CFA/I pilus filament. Our results indicate that strong end-to-end protein interactions and weak interactions between the coils of a sturdy spring-like helix provide the combination of strength, stability, and flexibility required to sustain bacterial adhesion and incite intestinal disease. We propose that CFA/I pili behave like a spring to maintain attachment to the gut lining during vortex mixing and downward flow of the intestinal contents, thereby persisting long enough for these bacteria to colonize the host epithelium and cause enteric disease.

Pili torti and multiple facial milia as an expression of ectodermal dysplasia in monozygotic twins

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Monika Sikorska

2014-03-01

Full Text Available Introduction . Genodermatoses – congenital diseases with diverse clinical presentation – are caused by ectodermal defects. pili torti and milia may be features of these defects. Concomitantly these symptoms are present in rare genodermatoses: Bazex-Dupre-Christol syndrome and Jackson-Lawler syndrome. Objective. Presentation of monozygotic twins with identical hair structure disturbances typical for pili torti and multiple facial milia and review of syndromes and diseases with pili torti and/or milia, with particular reference to Bazex-Dupre-Christol syndrome. Case report . Three-year-old monozygotic twins with identical disturbances of the hair, which was dry, brittle, torn and showed in microscopic examination features typical for pili torti – twisting of the hair shaft by 180 ° . The scalp was overdried and scaly. Numerous milia on the face of both girls appeared at the age of 2 years and were noticed during the examination. The remaining structures derived from the ectoderm were normal. The patients were treated with adapalene cream applied once a day with partial improvement of follicular lesions on the face in both sisters. Conclusions . Coexistence of pili torti and multiple milia in twins indicates the genetic background of these disturbances. Due to potential risk of development of skin carcinoma in future, the patients require close follow-up.

Mitis group streptococci express variable pilus islet 2 pili.

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Zähner, Dorothea; Gandhi, Ashish R; Yi, Hong; Stephens, David S

2011-01-01

Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits

Mitis group streptococci express variable pilus islet 2 pili.

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Dorothea Zähner

Full Text Available Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2-encoded pili to facilitate adhesion to eukaryotic cells.PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains.This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with

Pili Annulati Coincident with Alopecia Areata, Autoimmune Thyroid Disease, and Primary IgA Deficiency: Case Report and Considerations on the Literature

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E. Castelli

2012-11-01

Full Text Available Pili annulati is a rare autosomal dominant hair disorder clinically characterized by a pattern of alternating bright and dark bands of the hair, the bright bands appearing dark if observed by transmitted light. This pattern is due to the periodic occurrence of air-filled cavities along the hair cortex which scatter and reflect the light while precluding its transmission. A susceptibility region, including a possibly responsible Frizzled gene, has been mapped to the telomeric region of chromosome 12q, although a specific mutation has not been identified. The condition has sometimes been observed in concurrence with alopecia areata, and in this paper we report a case in whom the concomitant severe alopecia areata was associated with autoimmune thyroid disease and primary IgA deficiency – a quadruple complex which, to our knowledge, has never been previously described. The occurrence of multiple immune disorders in the same patient affected by pili annulati could represent a key to understanding the high prevalence of alopecia areata in this condition. Specifically, in individuals predisposed to autoimmune disease, the molecular alterations that cause the anatomical changes of pili annulati could prompt the immune response against the hair root that underlies alopecia areata.

A Structural Basis for Sustained Bacterial Adhesion – Biomechanical Properties of CFA/I Pili

OpenAIRE

Andersson, Magnus; Björnham, Oscar; Svantesson, Mats; Badahdah, Arwa; Uhlin, Bernt Eric; Bullitt, Esther

2011-01-01

Enterotoxigenic Escherichia coli (ETEC) are a major cause of diarrheal disease worldwide. Adhesion pili (or fimbriae), such as the CFA/I (colonization factor antigen I) organelles that enable ETEC to attach efficiently to the host intestinal tract epithelium, are critical virulence factors for initiation of infection. We characterized at single organelle level the intrinsic biomechanical properties and kinetics of individual CFA/I pili, demonstrating that weak external forces (7.5 pN) are suf...

Assembly mechanism of FCT region type 1 pili in serotype M6 Streptococcus pyogenes.

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Nakata, Masanobu; Kimura, Keiji Richard; Sumitomo, Tomoko; Wada, Satoshi; Sugauchi, Akinari; Oiki, Eiji; Higashino, Miharu; Kreikemeyer, Bernd; Podbielski, Andreas; Okahashi, Nobuo; Hamada, Shigeyuki; Isoda, Ryutaro; Terao, Yutaka; Kawabata, Shigetada

2011-10-28

The human pathogen Streptococcus pyogenes produces diverse pili depending on the serotype. We investigated the assembly mechanism of FCT type 1 pili in a serotype M6 strain. The pili were found to be assembled from two precursor proteins, the backbone protein T6 and ancillary protein FctX, and anchored to the cell wall in a manner that requires both a housekeeping sortase enzyme (SrtA) and pilus-associated sortase enzyme (SrtB). SrtB is primarily required for efficient formation of the T6 and FctX complex and subsequent polymerization of T6, whereas proper anchoring of the pili to the cell wall is mainly mediated by SrtA. Because motifs essential for polymerization of pilus backbone proteins in other Gram-positive bacteria are not present in T6, we sought to identify the functional residues involved in this process. Our results showed that T6 encompasses the novel VAKS pilin motif conserved in streptococcal T6 homologues and that the lysine residue (Lys-175) within the motif and cell wall sorting signal of T6 are prerequisites for isopeptide linkage of T6 molecules. Because Lys-175 and the cell wall sorting signal of FctX are indispensable for substantial incorporation of FctX into the T6 pilus shaft, FctX is suggested to be located at the pilus tip, which was also implied by immunogold electron microscopy findings. Thus, the elaborate assembly of FCT type 1 pili is potentially organized by sortase-mediated cross-linking between sorting signals and the amino group of Lys-175 positioned in the VAKS motif of T6, thereby displaying T6 and FctX in a temporospatial manner.

A helynevek szerepe az alternatív ideologikus gondolkodásban I. A Pilis-kultusz esete [The role of place names in an alternative ideological mindset I. The case of the Pilis Cult

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Imreh, Réka

2014-12-01

Full Text Available This paper focuses on the role of place names in defining and legitimizing the identity of a subculture through the example of a complex contemporary alternative social phenomenon known as the Pilis Cult. The Pilis Cult, which is also linked with some other alternative theories (Sumerian–Hungarian linguistic affinity, root linguistics, The Holy Crown Doctrine, claims that the Pilis Mountains as a spiritual space have a special role in Hungarian history. In the specific attitude to language and place names adopted by this subculture, one can recognize elements similar to those of ancient and medieval magical thinking. These can be observed in the interpretation of place names of the mountains, in which associations connected to the phonetic forms or the semantics of the place names may turn these toponyms into “telling names”, proving 120 Imreh Réka the antiquity and spirituality of the area. This etymological-associative narration is illustrated in the paper with the examples of the place names Pilis and Dobogó-kő. The interpretations of these names commingling with the alternative ideas connected to the denotata themselves (e.g. heart chakra theory; Proto-Buda Theories establish a unified argumentation framework. The paper argues that even a linguistically unorthodox subculture – alongside its specific ideology – may emphasize aspects of the study of place names through which our knowledge can be expanded with respect, for instance, to the functional logic behind place names.

Neisseria meningitidis differentially controls host cell motility through PilC1 and PilC2 components of type IV Pili.

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Philippe C Morand

Full Text Available Neisseria meningitidis is a strictly human pathogen that has two facets since asymptomatic carriage can unpredictably turn into fulminant forms of infection. Meningococcal pathogenesis relies on the ability of the bacteria to break host epithelial or endothelial cellular barriers. Highly restrictive, yet poorly understood, mechanisms allow meningococcal adhesion to cells of only human origin. Adhesion of encapsulated and virulent meningococci to human cells relies on the expression of bacterial type four pili (T4P that trigger intense host cell signalling. Among the components of the meningococcal T4P, the concomitantly expressed PilC1 and PilC2 proteins regulate pili exposure at the bacterial surface, and until now, PilC1 was believed to be specifically responsible for T4P-mediated meningococcal adhesion to human cells. Contrary to previous reports, we show that, like PilC1, the meningococcal PilC2 component is capable of mediating adhesion to human ME180 epithelial cells, with cortical plaque formation and F-actin condensation. However, PilC1 and PilC2 promote different effects on infected cells. Cellular tracking analysis revealed that PilC1-expressing meningococci caused a severe reduction in the motility of infected cells, which was not the case when cells were infected with PilC2-expressing strains. The amount of both total and phosphorylated forms of EGFR was dramatically reduced in cells upon PilC1-mediated infection. In contrast, PilC2-mediated infection did not notably affect the EGFR pathway, and these specificities were shared among unrelated meningococcal strains. These results suggest that meningococci have evolved a highly discriminative tool for differential adhesion in specific microenvironments where different cell types are present. Moreover, the fine-tuning of cellular control through the combined action of two concomitantly expressed, but distinctly regulated, T4P-associated variants of the same molecule (i.e. PilC1 and Pil

Involvement of T6 pili in biofilm formation by serotype M6 Streptococcus pyogenes.

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Kimura, Keiji Richard; Nakata, Masanobu; Sumitomo, Tomoko; Kreikemeyer, Bernd; Podbielski, Andreas; Terao, Yutaka; Kawabata, Shigetada

2012-02-01

The group A streptococcus (GAS) Streptococcus pyogenes is known to cause self-limiting purulent infections in humans. The role of GAS pili in host cell adhesion and biofilm formation is likely fundamental in early colonization. Pilus genes are found in the FCT (fibronectin-binding protein, collagen-binding protein, and trypsin-resistant antigen) genomic region, which has been classified into nine subtypes based on the diversity of gene content and nucleotide sequence. Several epidemiological studies have indicated that FCT type 1 strains, including serotype M6, produce large amounts of monospecies biofilm in vitro. We examined the direct involvement of pili in biofilm formation by serotype M6 clinical isolates. In the majority of tested strains, deletion of the tee6 gene encoding pilus shaft protein T6 compromised the ability to form biofilm on an abiotic surface. Deletion of the fctX and srtB genes, which encode pilus ancillary protein and class C pilus-associated sortase, respectively, also decreased biofilm formation by a representative strain. Unexpectedly, these mutant strains showed increased bacterial aggregation compared with that of the wild-type strain. When the entire FCT type 1 pilus region was ectopically expressed in serotype M1 strain SF370, biofilm formation was promoted and autoaggregation was inhibited. These findings indicate that assembled FCT type 1 pili contribute to biofilm formation and also function as attenuators of bacterial aggregation. Taken together, our results show the potential role of FCT type 1 pili in the pathogenesis of GAS infections.

Aloe; Beyond use as cosmetics | Pili | Dar Es Salaam Medical ...

African Journals Online (AJOL)

Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Aloe; Beyond use as cosmetics. K Pili. Abstract.

Impact of exchange-correlation effects on the IV characteristics of a molecular junction

DEFF Research Database (Denmark)

Thygesen, Kristian Sommer

2008-01-01

The role of exchange-correlation effects in nonequilibrium quantum transport through molecular junctions is assessed by analyzing the IV curve of a generic two-level model using self-consistent many-body perturbation theory (second Born and GW approximations) on the Keldysh contour. It is demonst...... of dynamic correlations introduces quasiparticle (QP) scattering which in turn broadens the molecular resonances. The broadening increases strongly with bias and can have a large impact on the calculated IV characteristic....

Common molecular determinants of tarantula huwentoxin-IV inhibition of Na+ channel voltage sensors in domains II and IV.

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Xiao, Yucheng; Jackson, James O; Liang, Songping; Cummins, Theodore R

2011-08-05

The voltage sensors of domains II and IV of sodium channels are important determinants of activation and inactivation, respectively. Animal toxins that alter electrophysiological excitability of muscles and neurons often modify sodium channel activation by selectively interacting with domain II and inactivation by selectively interacting with domain IV. This suggests that there may be substantial differences between the toxin-binding sites in these two important domains. Here we explore the ability of the tarantula huwentoxin-IV (HWTX-IV) to inhibit the activity of the domain II and IV voltage sensors. HWTX-IV is specific for domain II, and we identify five residues in the S1-S2 (Glu-753) and S3-S4 (Glu-811, Leu-814, Asp-816, and Glu-818) regions of domain II that are crucial for inhibition of activation by HWTX-IV. These data indicate that a single residue in the S3-S4 linker (Glu-818 in hNav1.7) is crucial for allowing HWTX-IV to interact with the other key residues and trap the voltage sensor in the closed configuration. Mutagenesis analysis indicates that the five corresponding residues in domain IV are all critical for endowing HWTX-IV with the ability to inhibit fast inactivation. Our data suggest that the toxin-binding motif in domain II is conserved in domain IV. Increasing our understanding of the molecular determinants of toxin interactions with voltage-gated sodium channels may permit development of enhanced isoform-specific voltage-gating modifiers.

The role of pili in Bacillus cereus intraocular infection.

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Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf

2017-06-01

Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity

Purification, identification and molecular mechanism of two dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from Antarctic krill (Euphausia superba) protein hydrolysate.

Science.gov (United States)

Ji, Wei; Zhang, Chaohua; Ji, Hongwu

2017-10-01

Dipeptidyl peptidase IV (DPP-IV) played an important role in blood glucose regulation. Inhibition of DPP-IV may improve glycemic control in diabetics by preventing the rapid breakdown of incretin hormones and prolonging their physiological action. In this study, Antarctic krill (Euphausia superba) protein was hydrolyzed using animal proteolytic enzymes. The hydrolysate was purified sequentially by ultrafiltration, gel filtration chromatography and reversed phase high-performance liquid chromatography (RP-HPLC). DPP-IV inhibitory activity of the fractions achieved from Antarctic krill protein was determined by DPP-IV screening reagent kit. Two purified peptides were identified by Xevo G2-XS QTof mass spectrometer (QTOF-MS). One peptide purified was Ala-Pro (AP) with IC 50 values of 0.0530mg/mL, the other Ile-Pro-Ala (IPA) with IC 50 values of 0.0370mg/mL. They both exhibited strong DPP-IV inhibitory activity. The molecular docking analysis revealed that DPP-IV inhibition by AP and IPA was mainly due to formation of a strong interaction surface force with the 91-96 and 101-105 amino acids of the DPP-IV. Our results suggested that the protein hydrolysate from Antarctic krill can be considered as a promising natural source of DPP-IV inhibitory peptides in the management of diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

Binding of CFA/I Pili of Enterotoxigenic Escherichia coli to Asialo-GM1 Is Mediated by the Minor Pilin CfaE.

Science.gov (United States)

Madhavan, T P Vipin; Riches, James D; Scanlon, Martin J; Ulett, Glen C; Sakellaris, Harry

2016-05-01

CFA/I pili are representatives of a large family of related pili that mediate the adherence of enterotoxigenic Escherichia coli to intestinal epithelial cells. They are assembled via the alternate chaperone-usher pathway and consist of two subunits, CfaB, which makes up the pilus shaft and a single pilus tip-associated subunit, CfaE. The current model of pilus-mediated adherence proposes that CFA/I has two distinct binding activities; the CfaE subunit is responsible for binding to receptors of unknown structure on erythrocyte and intestinal epithelial cell surfaces, while CfaB binds to various glycosphingolipids, including asialo-GM1. In this report, we present two independent lines of evidence that, contrary to the existing model, CfaB does not bind to asialo-GM1 independently of CfaE. Neither purified CfaB subunits nor CfaB assembled into pili bind to asialo-GM1. Instead, we demonstrate that binding activity toward asialo-GM1 resides in CfaE and this is essential for pilus binding to Caco-2 intestinal epithelial cells. We conclude that the binding activities of CFA/I pili for asialo-GM1, erythrocytes, and intestinal cells are inseparable, require the same amino acid residues in CfaE, and therefore depend on the same or very similar binding mechanisms. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Multiple roles of Pseudomonas aeruginosa TBCF10839 PilY1 in motility, transport and infection

DEFF Research Database (Denmark)

Bohn, Yu-Sing Tammy; Brandes, Gudrun; Rakhimova, Elza

2009-01-01

Polymorphonuclear neutrophils are the most important mammalian host defence cells against infections with Pseudomonas aeruginosa. Screening of a signature tagged mutagenesis library of the non-piliated P. aeruginosa strain TBCF10839 uncovered that transposon inactivation of its pilY1 gene rendere...

Diarrhea-associated biofilm formed by enteroaggregative Escherichia coli and aggregative Citrobacter freundii: a consortium mediated by putative F pili

Directory of Open Access Journals (Sweden)

Araújo Ana CG

2010-02-01

Full Text Available Abstract Background Enteroaggregative Escherichia coli (EAEC are enteropathogenic strains identified by the aggregative adhesion (AA pattern that share the capability to form biofilms. Citrobacter freundii is classically considered as an indigenous intestinal species that is sporadically associated with diarrhea. Results During an epidemiologic study focusing on infantile diarrhea, aggregative C. freundii (EACF and EAEC strains were concomitantly recovered from a severe case of mucous diarrhea. Thereby, the occurrence of synergic events involving these strains was investigated. Coinfection of HeLa cells with EACF and EAEC strains showed an 8-fold increase in the overall bacterial adhesion compared with single infections (P traA were capable of forming bacterial aggregates only in the presence of EACF. Scanning electronic microscopy analyses revealed that bacterial aggregates as well as enhanced biofilms formed by EACF and traA-positive EAEC were mediated by non-bundle forming, flexible pili. Moreover, mixed biofilms formed by EACF and traA-positive EAEC strains were significantly reduced using nonlethal concentration of zinc, a specific inhibitor of F pili. In addition, EAEC strains isolated from diarrheic children frequently produced single biofilms sensitive to zinc. Conclusions Putative F pili expressed by EAEC strains boosted mixed biofilm formation when in the presence of aggregative C. freundii.

Functional Analysis of Lactobacillus rhamnosus GG Pili in Relation to Adhesion and Immunomodulatory Interactions with Intestinal Epithelial Cells

Science.gov (United States)

Claes, Ingmar; Tytgat, Hanne L. P.; Verhoeven, Tine L. A.; Marien, Eyra; von Ossowski, Ingemar; Reunanen, Justus; Palva, Airi; de Vos, Willem M.; De Keersmaecker, Sigrid C. J.; Vanderleyden, Jos

2012-01-01

Lactobacillus rhamnosus GG, a probiotic with good survival capacity in the human gut, has well-documented adhesion properties and health effects. Recently, spaCBA-encoded pili that bind to human intestinal mucus were identified on its cell surface. Here, we report on the phenotypic analysis of a spaCBA pilus knockout mutant in comparison with the wild type and other adhesin mutants. The SpaCBA pilus of L. rhamnosus GG showed to be key for efficient adherence to the Caco-2 intestinal epithelial cell (IEC) line and biofilm formation. Moreover, the spaCBA mutant induces an elevated level of interleukin-8 (IL-8) mRNA in Caco-2 cells compared to the wild type, possibly involving an interaction of lipoteichoic acid with Toll-like receptor 2. In contrast, an L. rhamnosus GG mutant without exopolysaccharides but with an increased exposure of pili leads to the reduced expression of IL-8. Using Transwells to partition bacteria from Caco-2 cells, IL-8 induction is blocked completely regardless of whether wild-type or mutant L. rhamnosus GG cells are used. Taken together, our data suggest that L. rhamnosus GG SpaCBA pili, while promoting strong adhesive interactions with IECs, have a functional role in balancing IL-8 mRNA expression induced by surface molecules such as lipoteichoic acid. PMID:22020518

Hydration structures of U(III) and U(IV) ions from ab initio molecular dynamics simulations

International Nuclear Information System (INIS)

Leung, Kevin; Nenoff, Tina M.

2012-01-01

We apply DFT+U-based ab initio molecular dynamics simulations to study the hydration structures of U(III) and U(IV) ions, pertinent to redox reactions associated with uranium salts in aqueous media. U(III) is predicted to be coordinated to 8 water molecules, while U(IV) has a hydration number between 7 and 8. At least one of the innershell water molecules of the hydrated U(IV) complex becomes spontaneously deprotonated. As a result, the U(IV)–O pair correlation function exhibits a satellite peak at 2.15 Å associated with the shorter U(IV)–(OH − ) bond. This feature is not accounted for in analysis of extended x-ray absorption fine structure and x-ray adsorption near edge structure measurements, which yield higher estimates of U(IV) hydration numbers. This suggests that it may be useful to include the effect of possible hydrolysis in future interpretation of experiments, especially when the experimental pH is close to the reported hydrolysis equilibrium constant value.

Canarium ovatum Engl. (Pili exocarp crude extract as functional food colorant incorporated in yogurt developed product

Directory of Open Access Journals (Sweden)

Aril-dela Cruz, J.V.,

2017-09-01

Full Text Available Canarium ovatum Engl. (Pili, a locally grown plant in the Philippines, bears highly pigmented fruits. In this research study, the deeply pigmented fruit exocarp was evaluated for phytochemical contents, functional properties and possible application to yogurt as a colorant. Spectrophotometric analysis of the extract revealed high phenolic and flavonoid content, particularly anthocyanins (17.5 mg CE/g DW of the sample. The pigment extract also exhibited potential antioxidant activities as determined by DPPH and FRAP assays and did not show any inhibitory activity against gut normal flora, Escherichia coli, but also failed to express cytotoxic activity against HCT116 colon cancer cell line. Stability tests showed decreased redness with increasing temperature or pH. The pigment exhibited excellent color retention in yogurt during the two-week storage at 4oC. Sensory evaluation showed a slight difference in over-all acceptability between natural and synthetic-colored yogurt. Thus, Pili exocarp extract can be used as a functional food colorant in yogurt.

Phenotypical analysis of the Lactobacillus rhamnosus GG fimbrial spaFED operon: surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis.

Directory of Open Access Journals (Sweden)

Johanna Rintahaka

Full Text Available A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we

Phenotypical analysis of the Lactobacillus rhamnosus GG fimbrial spaFED operon: surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis.

Science.gov (United States)

Rintahaka, Johanna; Yu, Xia; Kant, Ravi; Palva, Airi; von Ossowski, Ingemar

2014-01-01

A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA) is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED) any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we have now provided

Surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis

OpenAIRE

Rintahaka, Johanna; Yu, Xia; Kant, Ravi; Palva, Airi; von Ossowski, Ingemar

2014-01-01

A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA) is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED) any native expression of the SpaFED-called pili is still the subject of some u...

Functional Analysis of Lactobacillus rhamnosus GG Pili in Relation to Adhesion and Immunomodulatory Interactions with Intestinal Epithelial Cells

NARCIS (Netherlands)

Lebeer, S.; Claes, I.J.; Tytgat, H.L.P.; Verhoeven, T.L.A.; Marien, E.; Ossowski, von I.; Reunanen, J.; Palva, A.; Vos, de W.M.; Keersmaecker, de S.C.; Vanderleyden, J.

2012-01-01

Lactobacillus rhamnosus GG, a probiotic with good survival capacity in the human gut, has well-documented adhesion properties and health effects. Recently, spaCBA-encoded pili that bind to human intestinal mucus were identified on its cell surface. Here, we report on the phenotypic analysis of a

Functional genome analysis of Bifidobacterium breve UCC2003 reveals type IVb tight adherence (Tad) pili as an essential and conserved host-colonization factor

Science.gov (United States)

O'Connell Motherway, Mary; Zomer, Aldert; Leahy, Sinead C.; Reunanen, Justus; Bottacini, Francesca; Claesson, Marcus J.; O'Brien, Frances; Flynn, Kiera; Casey, Patrick G.; Moreno Munoz, Jose Antonio; Kearney, Breda; Houston, Aileen M.; O'Mahony, Caitlin; Higgins, Des G.; Shanahan, Fergus; Palva, Airi; de Vos, Willem M.; Fitzgerald, Gerald F.; Ventura, Marco; O'Toole, Paul W.; van Sinderen, Douwe

2011-01-01

Development of the human gut microbiota commences at birth, with bifidobacteria being among the first colonizers of the sterile newborn gastrointestinal tract. To date, the genetic basis of Bifidobacterium colonization and persistence remains poorly understood. Transcriptome analysis of the Bifidobacterium breve UCC2003 2.42-Mb genome in a murine colonization model revealed differential expression of a type IVb tight adherence (Tad) pilus-encoding gene cluster designated “tad2003.” Mutational analysis demonstrated that the tad2003 gene cluster is essential for efficient in vivo murine gut colonization, and immunogold transmission electron microscopy confirmed the presence of Tad pili at the poles of B. breve UCC2003 cells. Conservation of the Tad pilus-encoding locus among other B. breve strains and among sequenced Bifidobacterium genomes supports the notion of a ubiquitous pili-mediated host colonization and persistence mechanism for bifidobacteria. PMID:21690406

Functional genome analysis of Bifidobacterium breve UCC2003 reveals type IVb tight adherence (Tad) pili as an essential and conserved host-colonization factor.

Science.gov (United States)

O'Connell Motherway, Mary; Zomer, Aldert; Leahy, Sinead C; Reunanen, Justus; Bottacini, Francesca; Claesson, Marcus J; O'Brien, Frances; Flynn, Kiera; Casey, Patrick G; Munoz, Jose Antonio Moreno; Kearney, Breda; Houston, Aileen M; O'Mahony, Caitlin; Higgins, Des G; Shanahan, Fergus; Palva, Airi; de Vos, Willem M; Fitzgerald, Gerald F; Ventura, Marco; O'Toole, Paul W; van Sinderen, Douwe

2011-07-05

Development of the human gut microbiota commences at birth, with bifidobacteria being among the first colonizers of the sterile newborn gastrointestinal tract. To date, the genetic basis of Bifidobacterium colonization and persistence remains poorly understood. Transcriptome analysis of the Bifidobacterium breve UCC2003 2.42-Mb genome in a murine colonization model revealed differential expression of a type IVb tight adherence (Tad) pilus-encoding gene cluster designated "tad(2003)." Mutational analysis demonstrated that the tad(2003) gene cluster is essential for efficient in vivo murine gut colonization, and immunogold transmission electron microscopy confirmed the presence of Tad pili at the poles of B. breve UCC2003 cells. Conservation of the Tad pilus-encoding locus among other B. breve strains and among sequenced Bifidobacterium genomes supports the notion of a ubiquitous pili-mediated host colonization and persistence mechanism for bifidobacteria.

Sandia octahedral molecular sieves (SOMS): structural and property effects of charge-balancing the M(IV)-substituted (M = Ti, Zr) Niobate framework.

Science.gov (United States)

Nyman, May; Tripathi, Akhilesh; Parise, John B; Maxwell, Robert S; Nenoff, Tina M

2002-02-27

Sandia octahedral molecular sieves (SOMS) is an isostructural, variable composition class of ion exchangers with the general formula Na(2)Nb(2-x)M(IV)(x)O (6-x)(OH)(x).H(2)O (M(IV) = Ti, Zr; x = 0.04-0.40) where up to 20% of the framework Nb(V) can be substituted with Ti(IV) or Zr(IV). This class of molecular sieves is easily converted to perovskite through low-temperature heat treatment (500-600 degrees C). This report provides a detailed account of how the charge imbalance of this Nb(V)-M(IV) substitution is compensated. X-ray powder diffraction with Rietveld refinement, infrared spectroscopy, thermogravimetric analysis, (23)Na MAS NMR, and (1)H MAS NMR were used to determine how the framework anionic charge is cation-balanced over a range of framework compositions. All spectroscopic evidence indicated a proton addition for each M(IV) substitution. Evidences for variable proton content included (1) increasing OH observed by (1)H MAS NMR with increasing M(IV) substitution, (2) increased infrared band broadening indicating increased H-bonding with increasing M(IV) substitution, (3) increased TGA weight loss (due to increased OH content) with increasing M(IV) substitution, (4) no variance in population on the sodium sites (indicated by Rietveld refinement) with variable composition, and (5) no change in the (23)Na MAS NMR spectra with variable composition. Also observed by infrared spectroscopy and (23)Na MAS NMR was increased disorder on the Nb(V)/M(IV) framework sites with increasing M(IV) substitution, evidenced by broadening of these spectral features. These spectroscopic studies, along with ion exchange experiments, also revealed the effect of the Nb(V)/M(IV) framework substitution on materials properties. Namely, the temperature of conversion to NaNb(1-x)M(IV)(x)O(3) (M = Ti, Zr) perovskite increased with increasing Ti in the framework and decreased with increasing Zr in the framework. This suggested that Ti stabilizes the SOMS framework and Zr destabilizes

Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli.

Science.gov (United States)

Kolappan, Subramania; Ng, Dixon; Yang, Guixiang; Harn, Tony; Craig, Lisa

2015-10-23

Type IV pili are extracellular polymers of the major pilin subunit. These subunits are held together in the pilus filament by hydrophobic interactions among their N-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. Type IV pilus assembly involves a conserved group of proteins that span the envelope of Gram-negative bacteria. Among these is a set of minor pilins, so named because they share their hydrophobic N-terminal polymerization/membrane anchor segment with the major pilins but are much less abundant. Minor pilins influence pilus assembly and retraction, but their precise functions are not well defined. The Type IV pilus systems of enterotoxigenic Escherichia coli and Vibrio cholerae are among the simplest of Type IV pilus systems and possess only a single minor pilin. Here we show that the enterotoxigenic E. coli minor pilins CofB and LngB are required for assembly of their respective Type IV pili, CFA/III and Longus. Low levels of the minor pilins are optimal for pilus assembly, and CofB can be detected in the pilus fraction. We solved the 2.0 Å crystal structure of N-terminally truncated CofB, revealing a pilin-like protein with an extended C-terminal region composed of two discrete domains connected by flexible linkers. The C-terminal region is required for CofB to initiate pilus assembly. We propose a model for CofB-initiated pilus assembly with implications for understanding filament growth in more complex Type IV pilus systems as well as the related Type II secretion system. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Surface Proteome Analysis of a Natural Isolate of Lactococcus lactis Reveals the Presence of Pili Able to Bind Human Intestinal Epithelial Cells*

Science.gov (United States)

Meyrand, Mickael; Guillot, Alain; Goin, Mélodie; Furlan, Sylviane; Armalyte, Julija; Kulakauskas, Saulius; Cortes-Perez, Naima G.; Thomas, Ginette; Chat, Sophie; Péchoux, Christine; Dupres, Vincent; Hols, Pascal; Dufrêne, Yves F.; Trugnan, Germain; Chapot-Chartier, Marie-Pierre

2013-01-01

Surface proteins of Gram-positive bacteria play crucial roles in bacterial adhesion to host tissues. Regarding commensal or probiotic bacteria, adhesion to intestinal mucosa may promote their persistence in the gastro-intestinal tract and their beneficial effects to the host. In this study, seven Lactococcus lactis strains exhibiting variable surface physico-chemical properties were compared for their adhesion to Caco-2 intestinal epithelial cells. In this test, only one vegetal isolate TIL448 expressed a high-adhesion phenotype. A nonadhesive derivative was obtained by plasmid curing from TIL448, indicating that the adhesion determinants were plasmid-encoded. Surface-exposed proteins in TIL448 were analyzed by a proteomic approach consisting in shaving of the bacterial surface with trypsin and analysis of the released peptides by LC-MS/MS. As the TIL448 complete genome sequence was not available, the tryptic peptides were identified by a mass matching approach against a database including all Lactococcus protein sequences and the sequences deduced from partial DNA sequences of the TIL448 plasmids. Two surface proteins, encoded by plasmids in TIL448, were identified as candidate adhesins, the first one displaying pilin characteristics and the second one containing two mucus-binding domains. Inactivation of the pilin gene abolished adhesion to Caco-2 cells whereas inactivation of the mucus-binding protein gene had no effect on adhesion. The pilin gene is located inside a cluster of four genes encoding two other pilin-like proteins and one class-C sortase. Synthesis of pili was confirmed by immunoblotting detection of high molecular weight forms of pilins associated to the cell wall as well as by electron and atomic force microscopy observations. As a conclusion, surface proteome analysis allowed us to detect pilins at the surface of L. lactis TIL448. Moreover we showed that pili appendages are formed and involved in adhesion to Caco-2 intestinal epithelial cells

Functional mapping of PilF and PilQ in the Pseudomonas aeruginosa type IV pilus system.

Science.gov (United States)

Koo, Jason; Tang, Tim; Harvey, Hanjeong; Tammam, Stephanie; Sampaleanu, Liliana; Burrows, Lori L; Howell, P Lynne

2013-04-30

Pseudomonas aeruginosa uses type IV pili (T4P) to interact with the environment and as key virulence factors when acting as an opportunistic pathogen. Assembly of the outer membrane PilQ secretin channel through which the pili are extruded is essential for pilus biogenesis. The P. aeruginosa T4P pilotin, PilF, is required for PilQ outer membrane localization and assembly into secretins and contains six tetratricopeptide (TPR) protein-protein interaction motifs, suggesting that the two proteins interact. In this study, we found that the first four TPR motifs of PilF are sufficient for PilQ outer membrane targeting, oligomerization, and function. Guided by our structure of PilF, site-directed mutagenesis of the protein surface revealed that a hydrophobic groove on the first TPR is required for PilF-mediated PilQ assembly. Deletion of individual domains within PilQ suggests that the N0, KH-like, or secretin domain, but not the C-terminus, interacts with PilF. Purified PilQ was found to pull down PilF from Pseudomonas cell lysates. Together, these data allow us to propose a model for PilF function in the T4P system. PilF interacts directly or indirectly with the PilQ monomer after translocation of both proteins through the inner membrane and acts as a co-chaperone with the Lol system to facilitate transit across the periplasm to the outer membrane. The mechanism of PilQ insertion and assembly, which appears to be independent of the Bam system, remains to be determined.

Glycogen Storage Disease Type IV

DEFF Research Database (Denmark)

Bendroth-Asmussen, Lisa; Aksglaede, Lise; Gernow, Anne B

2016-01-01

molecular genetic analyses confirmed glycogen storage disease Type IV with the finding of compound heterozygosity for 2 mutations (c.691+2T>C and c.1570C>T, p.R524X) in the GBE1 gene. We conclude that glycogen storage disease Type IV can cause early miscarriage and that diagnosis can initially be made...

Identification of an operon, Pil-Chp, that controls twitching motility and virulence in Xylella fastidiosa.

Science.gov (United States)

Cursino, Luciana; Galvani, Cheryl D; Athinuwat, Dusit; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia

2011-10-01

Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.

Thorium(IV) and zirconium(IV) complexes of oxygen donor ligands. Pt. 12

International Nuclear Information System (INIS)

Agarwal, R.K.; Jain, P.C.; Kapur, V.; Sharma, S.; Srivastava, A.K.

1980-01-01

Crystalline thorium (IV) chelates with mono N-oxides of 2,2'-bipyridine (bipyNO) and 1,10-phenanthroline (phenNO), ThX 4 x 2L(X = Cl,Br,NO 3 or NCS) and ThX 4 x 3L(X = I or ClO 4 and L = bipyNO or phenNO) have been synthesised and characterized on the basis of i.r. spectra, molar conductance, molecular weights, t.g.a. and d.t.a. data. All the complexes are weakly diamagnetic and contain bipyNO and phenNO bonded to thorium(IV) through nitrogen and oxygen. The coordination number of thorium(IV) varies from six to twelve depending on the nature of the anions. (orig.) [de

Synthesis and characterization of thorium(IV) and uranium(IV) complexes with Schiff bases

Energy Technology Data Exchange (ETDEWEB)

Radoske, Thomas; Maerz, Juliane; Kaden, Peter; Patzschke, Michael; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements

2017-06-01

We report herein the synthesis and characterization of several imine complexes of tetravalent thorium (Th(IV)) and uranium (U(IV)). The ligands investigated in this study are a Schiff base type, including the well-known salen ligand (H{sub 2}Le, Fig. 1). The complexation in solution was investigated by NMR measurements indicating paramagnetic effects of unpaired f-electrons of U(IV) on the ligand molecule. We also determined the solid-state molecular structures of the synthesized complexes by single crystal X-ray diffraction. The synthesized complexes show an eight-fold coordination geometry around the actinide center surrounded by two tetradentate ligands with 2N- and 2O-donor atoms.

Synthesis and molecular structure of (monoaqua) oxovanadium (IV) thiosemicarbazide-diacetate monohydrate

International Nuclear Information System (INIS)

Gerbeleu, N.V.; Bologa, A.O.; Burshtein, I.F.; Filippova, I.G.; Kiosse, G.A.

1986-01-01

This paper describes the structure for a new complex of oxovanadium (IV) with H 2 L. This compound was obtained by mixing warm aqueous solutions containing 1.0 g VOSO 4 .2H 2 O and H 2 L at room temperature. The coordinates and the individual temperature factors of the basis atoms in the structure VOLH 2 O .H 2 O are presented. It is shown that the vanadium atom in both complexes has a distorted octahedral environment. The geometrical isomerism is accompanied by differences in the conformations of the molecular ligand. Two geometrical isomers of a previously unknown type are concurrently present in the VOLH 2 O structure. The formation of these isomers is made possible by the different arrangement of inequivalent branches of the organic ligand. This type of isomerism should be expected in the complexes of other metals with H 2 L and in the coordination compounds of metals with other B-type tripod ligands

Etlik Piliçlerin Beslenmesinde Böceklerin Kullanılması

Directory of Open Access Journals (Sweden)

Özgün Işık

2017-07-01

Full Text Available Hızlı ve yüksek canlı ağırlık artışının esas alındığı etlik piliç üretiminde, hayvanların besin maddesi ve enerji ihtiyaçlarını karşılamak önemlidir. Bu ihtiyaçları karşılamak için kullanılan geleneksel yem hammaddelerinin üretiminde ve ithalatında yaşanan sorunlar nedeniyle, alternatif yem hammaddeleri aranmaktadır. Bu amaçla tavukların doğal rasyonlarında bulunan böcekler umut verici gözükmektedir. Özellikle protein yemlerine alternatif olarak üzerinde en çok çalışma yapılan türler arasında asker sineği (Hermetica illucens, karasinek (Musca domestica, çayır cırcır böceği (Gryllus testaceus, ipek böceği (Bombyx mori, çekirge (Acrididae ve un kurdu (Tenebrio molitor yer almaktadır.

Spectroscopy and chemistry of uranium IV

International Nuclear Information System (INIS)

Folcher, G.; Rigny, P.

1980-06-01

Different fundamental research papers on uranium IV are presented, some were never edited. Molecular spectroscopy was used for identification and structural study of uranium IV in aqueous or organic solutions. The fields studied are: coordination, stereochemistry, electronic structure and chemical properties. For interpretation of results some studies were made with solid compounds or with thorium compounds or thorium complexes. Knowledge of actinides chemistry is improved, uranium and thorium being models for 5 f ions, extractive chemistry is better understood and new applications are possible [fr

Metal-like transport in proteins: A new paradigm for biological electron transfer

Science.gov (United States)

Malvankar, Nikhil; Vargas, Madeline; Tuominen, Mark; Lovley, Derek

2012-02-01

Electron flow in biologically proteins generally occurs via tunneling or hopping and the possibility of electron delocalization has long been discounted. Here we report metal-like transport in protein nanofilaments, pili, of bacteria Geobacter sulfurreducens that challenges this long-standing belief [1]. Pili exhibit conductivities comparable to synthetic organic metallic nanostructures. The temperature, magnetic field and gate-voltage dependence of pili conductivity is akin to that of quasi-1D disordered metals, suggesting a metal-insulator transition. Magnetoresistance (MR) data provide evidence for quantum interference and weak localization at room temperature, as well as a temperature and field-induced crossover from negative to positive MR. Furthermore, pili can be doped with protons. Structural studies suggest the possibility of molecular pi stacking in pili, causing electron delocalization. Reducing the disorder increases the metallic nature of pili. These electronically functional proteins are a new class of electrically conductive biological proteins that can be used to generate future generation of inexpensive and environmentally-sustainable nanomaterials and nanolectronic devices such as transistors and supercapacitors. [1] Malvankar et al. Nature Nanotechnology, 6, 573-579 (2011)

Pilus Biogenesis in Lactococcus lactis: Molecular Characterization and Role in Aggregation and Biofilm Formation

Science.gov (United States)

Oxaran, Virginie; Ledue-Clier, Florence; Dieye, Yakhya; Herry, Jean-Marie; Péchoux, Christine; Meylheuc, Thierry; Briandet, Romain; Juillard, Vincent; Piard, Jean-Christophe

2012-01-01

The genome of Lactococcus lactis strain IL1403 harbors a putative pilus biogenesis cluster consisting of a sortase C gene flanked by 3 LPxTG protein encoding genes (yhgD, yhgE, and yhhB), called here pil. However, pili were not detected under standard growth conditions. Over-expression of the pil operon resulted in production and display of pili on the surface of lactococci. Functional analysis of the pilus biogenesis machinery indicated that the pilus shaft is formed by oligomers of the YhgE pilin, that the pilus cap is formed by the YhgD pilin and that YhhB is the basal pilin allowing the tethering of the pilus fibers to the cell wall. Oligomerization of pilin subunits was catalyzed by sortase C while anchoring of pili to the cell wall was mediated by sortase A. Piliated L. lactis cells exhibited an auto-aggregation phenotype in liquid cultures, which was attributed to the polymerization of major pilin, YhgE. The piliated lactococci formed thicker, more aerial biofilms compared to those produced by non-piliated bacteria. This phenotype was attributed to oligomers of YhgE. This study provides the first dissection of the pilus biogenesis machinery in a non-pathogenic Gram-positive bacterium. Analysis of natural lactococci isolates from clinical and vegetal environments showed pili production under standard growth conditions. The identification of functional pili in lactococci suggests that the changes they promote in aggregation and biofilm formation may be important for the natural lifestyle as well as for applications in which these bacteria are used. PMID:23236417

Rethinking Molecular Mimicry in Rheumatic Heart Disease andAutoimmune Myocarditis: Laminin, Collagen IV, CAR and B1AR as Initial Targets of Disease

Directory of Open Access Journals (Sweden)

Robert eRoot-Bernstein

2014-08-01

Full Text Available Rationale: Molecular mimicry theory (MMT suggests that epitope mimicry between pathogens and human proteins can activate autoimmune disease. Group A streptococci (GAS mimics human cardiac myosin in rheumatic heart disease (RHD and coxsackie viruses (CX mimic actin in autoimmune myocarditis (AM. But myosin and actin are immunologically inaccessible and unlikely initial targets. Extracellular cardiac proteins that mimic GAS and CX would be more likely.Objectives: To determine whether extracellular cardiac proteins such as coxsackie and adenovirus receptor (CAR, beta 1 adrenergic receptor (B1AR, CD55/DAF, laminin, and collagen IV mimic GAS, CX and/or cardiac myosin or actin. Methods: BLAST 2.0 and LALIGN searches of the UniProt protein database were employed to identify potential molecular mimics. Quantitative ELISA was used to measure antibody cross-reactivity. Measurements: Similarities were considered to be significant if a sequence contained at least 5 identical amino acids in 10. Antibodies were considered to be cross-reactive if the binding constant had a Kd less than 10-9 M. Main Results: GAS mimics laminin, CAR and myosin. CX mimics actin and collagen IV and B1AR. The similarity search results are mirrored by antibody cross-reactivities. Additionally, antibodies against laminin recognize antibodies against collagen IV; antibodies against actin recognize antibodies against myosin, and antibodies against GAS recognize antibodies against CX. Thus, there is both mimicry of extracellular proteins and antigenic complementarity between GAS-CX in RHD/AM.Conclusions: RHD/AM may be due to combined infections of GAS with CX localize at cardiomyocytes may produce a synergistic, hyperinflammatory response that cross-reacts with laminin, collagen IV, CAR and/or B1AR. Epitope drift shifts the immune response to myosin and actin after cardiomyocytes become damaged.

Transcriptional activation of the tad type IVb pilus operon by PypB in Yersinia enterocolitica.

Science.gov (United States)

Schilling, Jennifer; Wagner, Karin; Seekircher, Stephanie; Greune, Lilo; Humberg, Verena; Schmidt, M Alexander; Heusipp, Gerhard

2010-07-01

Type IV pili are virulence factors in various bacteria and mediate, among other functions, the colonization of diverse surfaces. Various subclasses of type IV pili have been identified, but information on pilus expression, biogenesis, and the associated phenotypes is sparse for the genus Yersinia. We recently described the identification of PypB as a transcriptional regulator in Yersinia enterocolitica. Here we show that the pypB gene is associated with the tad locus, a genomic island that is widespread among bacterial and archaeal species. The genetic linkage of pypB with the tad locus is conserved throughout the yersiniae but is not found among other bacteria carrying the tad locus. We show that the genes of the tad locus form an operon in Y. enterocolitica that is controlled by PypB and that pypB is part of this operon. The tad genes encode functions necessary for the biogenesis of the Flp subfamily of type IVb pili initially described for Aggregatibacter actinomycetemcomitans to mediate a tight-adherence phenotype. In Y. enterocolitica, the Flp pilin protein shows some peculiarities in its amino acid sequence that imply similarities as well as differences compared to typical motifs found in the Flp subtype of type IVb pili. Flp is expressed and processed after PypB overproduction, resulting in microcolony formation but not in increased adherence to biotic or abiotic surfaces. Our data describe the transcriptional regulation of the tad type IVb pilus operon by PypB in Y. enterocolitica but fail to show most previously described phenotypes associated with this type of pilus in other bacteria.

Predicting DPP-IV inhibitors with machine learning approaches

Science.gov (United States)

Cai, Jie; Li, Chanjuan; Liu, Zhihong; Du, Jiewen; Ye, Jiming; Gu, Qiong; Xu, Jun

2017-04-01

Dipeptidyl peptidase IV (DPP-IV) is a promising Type 2 diabetes mellitus (T2DM) drug target. DPP-IV inhibitors prolong the action of glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), improve glucose homeostasis without weight gain, edema, and hypoglycemia. However, the marketed DPP-IV inhibitors have adverse effects such as nasopharyngitis, headache, nausea, hypersensitivity, skin reactions and pancreatitis. Therefore, it is still expected for novel DPP-IV inhibitors with minimal adverse effects. The scaffolds of existing DPP-IV inhibitors are structurally diversified. This makes it difficult to build virtual screening models based upon the known DPP-IV inhibitor libraries using conventional QSAR approaches. In this paper, we report a new strategy to predict DPP-IV inhibitors with machine learning approaches involving naïve Bayesian (NB) and recursive partitioning (RP) methods. We built 247 machine learning models based on 1307 known DPP-IV inhibitors with optimized molecular properties and topological fingerprints as descriptors. The overall predictive accuracies of the optimized models were greater than 80%. An external test set, composed of 65 recently reported compounds, was employed to validate the optimized models. The results demonstrated that both NB and RP models have a good predictive ability based on different combinations of descriptors. Twenty "good" and twenty "bad" structural fragments for DPP-IV inhibitors can also be derived from these models for inspiring the new DPP-IV inhibitor scaffold design.

The anchoring effect on the spin transport properties and I-V characteristics of pentacene molecular devices suspended between nickel electrodes.

Science.gov (United States)

Caliskan, S; Laref, A

2014-07-14

Spin-polarized transport properties are determined for pentacene sandwiched between Ni surface electrodes with various anchoring ligands. These calculations are carried out using spin density functional theory in tandem with a non-equilibrium Green's function technique. The presence of a Se atom at the edge of the pentacene molecule significantly modifies the transport properties of the device because Se has a different electronegativity than S. Our theoretical results clearly show a larger current for spin-up electrons than for spin-down electrons in the molecular junction that is attached asymmetrically across the Se linker at one side of the Ni electrodes (in an APL magnetic orientation). Moreover, this molecular junction exhibits pronounced NDR as the bias voltage is increased from 0.8 to 1.0 V. However, this novel NDR behavior is only detected in this promising pentacene molecular device. The NDR in the current-voltage (I-V) curve results from the narrowness of the density of states for the molecular states. The feasibility of controlling the TMR is also predicted in these molecular device nanostructures. Spin-dependent transmission calculations show that the sign and strength of the current-bias voltage characteristics and the TMR could be tailored for the organic molecule devices. These molecular junctions are joined symmetrically and asymmetrically between Ni metallic probes across the S and Se atoms (at the ends of the edges of the pentacene molecule). Our theoretical findings show that spin-valve phenomena can occur in these prototypical molecular junctions. The TMR and NDR results show that nanoscale junctions with spin valves could play a vital role in the production of novel functional molecular devices.

Synthesis, characterization, and molecular structure of tetraethylammonium pentakis(isothiocyanato)bis(2,2'-bipyridine)uranate(IV)

International Nuclear Information System (INIS)

Wiley, R.O.; Von Dreele, R.B.; Brown, T.M.

1980-01-01

The synthesis of tetraethylammonium pentakis(isothiocyanato)bis(2,2'-bipyridine)uranate(IV) has been accomplished, and it was characterized by classical physical methods. The crystal and molecular structure was determined from single-crystal x-ray data collected by the theta-2theta technique on an automated diffractometer. The compound consists of pentakis(isothiocyanato)bis (2,2'-bipyridine)uranate(IV) anions and disordered tetraethylammonium cations. Uranium is bound to nine nitrogen atoms in a highly distorted monocapped square antiprism in which one bipyridine occupies a position bridging the cap and the near square while the other bipyridine spans the opposite edge of the far square. Distortion from the ideal geometry is caused by the small ligand bite of the bipyridine ligand. An alternative description of the coordination geometry is derived from the seven-coordinate pentagonal bipyramid in which each bipyridine ligand is assumed to occupy an axial position with the five thiocyanato ligands forming the pentagonal girdle. The U-N bond distances vary from 2.35 to 2.47 A for the thiocyanato ligands and from 2.61 to 2.65 A for the bipyridine ligands. The structure was solved by standard heavy-atom techniques and refined by large-block matrix least squares to a final R value of 0.083 for 3878 independent observed reflections. The compound crystallized in the monoclinic space group P2 1 /c, Z = 4, with lattice parameters a = 14.427 (10) A, b = 18.612 (17) A, c = 15.710 (10) A, and β = 105.17 (7) 0 , rho/sub obsd/ = 1.57 g cm -3

The chemotaxis regulator pilG of Xylella fastidiosa is required for virulence in Vitis vinifera grapevines

Science.gov (United States)

Type IV pili of X. fastidiosa are regulated by pilG, a response regulator protein putatively involved in chemotaxis-like operon sensing stimuli through signal transduction pathways. To elucidate roles of pilG in pathogenicity of X. fastidiosa, the pilG-deletion mutant and complementary strain contai...

Physiochemical Characteristics and Molecular Structures for Digestible Carbohydrates of Silages.

Science.gov (United States)

Refat, Basim; Prates, Luciana L; Khan, Nazir A; Lei, Yaogeng; Christensen, David A; McKinnon, John J; Yu, Peiqiang

2017-10-18

The main objectives of this study were (1) to assess the magnitude of differences among new barley silage varieties (BS) selected for varying rates of in vitro neutral detergent fiber (NDF) digestibility (ivNDFD; Cowboy BS with higher ivNDFD, Copeland BS with intermediate ivNDFD, and Xena BS with lower ivNDFD) with regard to their carbohydrate (CHO) molecular makeup, CHO chemical fractions, and rumen degradability in dairy cows in comparison with a new corn silage hybrid (Pioneer 7213R) and (2) to quantify the strength and pattern of association between the molecular structures and digestibility of carbohydrates. The carbohydrate-related molecular structure spectral data was measured using advanced vibrational molecular spectroscopy (FT/IR). In comparison to BS, corn silage showed a significantly (P carbohydrates were significantly (P carbohydrate content of the silages. In conclusion, the univariate approach with only one-factor consideration (ivNDFD) might not be a satisfactory method for evaluating and ranking BS quality. FT/IR molecular spectroscopy can be used to evaluate silage quality rapidly, particularly the digestible fiber content.

Molecular dynamics studies of the P pilus rod subunit PapA.

Science.gov (United States)

Vitagliano, Luigi; Ruggiero, Alessia; Pedone, Carlo; Berisio, Rita

2009-03-01

Adhesion of uropathogenic Escherichia coli to host tissues is mediated by pili, which extend from the outer cell membrane of the bacterium. Here we report molecular dynamics (MD) characterizations of the major constituent of P pili from the uropathogenic E. coli, PapA, in unliganded state and in complex with the G1 strand of the chaperone PapD. To mimic the PapA response to the gradual dissociation of the PapD G1 strand and to evaluate the role of PapA chaperone recognition sites, we also carried out MD simulations of complexes of PapA with fragments of PapD G1 strand, that leave either the P4 or both P3 and P4 sites unoccupied. Data on the unbound form of PapA indicate that, upon release of the chaperone, PapA evolves toward compact states that are likely not prone to subunit-subunit association. In line with recent experimental reports, this finding implies that chaperone release and subunit-subunit association must be concerted. Our data also indicated that the gradual unbinding of the chaperone from the PapA groove has increasingly strong structural consequences. Indeed, the release of the chaperone from the site P4, which is closest to the initiation site (P5), does not have dramatic effects on the domain structure, whereas its release from both the P4 and the adjacent P3 sites induces a quick structural transition toward a collapsed state, where the subunit groove is obstructed.

Genomic and Functional Characterization of the Unusual pLOCK 0919 Plasmid Harboring the spaCBA Pili Cluster in Lactobacillus casei LOCK 0919

Science.gov (United States)

Aleksandrzak-Piekarczyk, Tamara; Koryszewska-Bagińska, Anna; Grynberg, Marcin; Nowak, Adriana; Cukrowska, Bożena; Kozakova, Hana; Bardowski, Jacek

2016-01-01

Here, we report the extensive bioinformatic and functional analyses of the unusual pLOCK 0919, a plasmid originating from the probiotic Lactobacillus casei LOCK 0919 strain. This plasmid is atypical because it harbors the spaCBA-srtC gene cluster encoding SpaCBA pili. We show that all other spaCBA-srtC sequences of the Lactobacillus genus that have been previously described and deposited in GenBank are present in the chromosomal DNA. Another important observation for pLOCK 0919 is that the spaCBA-srtC gene cluster and its surrounding genes are highly similar to the respective DNA region that is present in the most well-known and active SpaCBA pili producer, the probiotic Lactobacillus rhamnosus GG strain. Our results demonstrate that the spaCBA-srtC clusters of pLOCK 0919 and L. rhamnosus GG are genealogically similar, located in DNA regions that are rich in transposase genes and are poorly conserved among the publicly available sequences of Lactobacillus sp. In contrast to chromosomally localized pilus gene clusters from L. casei and Lactobacillus paracasei, the plasmidic spaC of L. casei LOCK 0919 is expressed and undergoes a slight glucose-induced repression. Moreover, results of series of in vitro tests demonstrate that L. casei LOCK 0919 has an adhesion potential, which is largely determined by the presence of the pLOCK 0919 plasmid. In particular, the plasmid occurrence positively influenced the hydrophobicity and aggregation abilities of L. casei LOCK 0919. Moreover, in vivo studies indicate that among the three Lactobacillus strains used to colonize the gastrointestinal tract of germ-free mice, already after 2 days of colonization, L. casei LOCK 0919 became the dominant strain and persisted there for at least 48 days. PMID:26637469

Halogens are key cofactors in building of collagen IV scaffolds outside the cell.

Science.gov (United States)

Brown, Kyle L; Hudson, Billy G; Voziyan, Paul A

2018-05-01

The purpose of this review is to highlight recent advances in understanding the molecular assembly of basement membranes, as exemplified by the glomerular basement membrane (GBM) of the kidney filtration apparatus. In particular, an essential role of halogens in the basement membrane formation has been discovered. Extracellular chloride triggers a molecular switch within non collagenous domains of collagen IV that induces protomer oligomerization and scaffold assembly outside the cell. Moreover, bromide is an essential cofactor in enzymatic cross-linking that reinforces the stability of scaffolds. Halogenation and halogen-induced oxidation of the collagen IV scaffold in disease states damage scaffold function. Halogens play an essential role in the formation of collagen IV scaffolds of basement membranes. Pathogenic damage of these scaffolds by halogenation and halogen-induced oxidation is a potential target for therapeutic interventions.

Plasma metabolism of apolipoprotein A-IV in humans

International Nuclear Information System (INIS)

Ghiselli, G.; Krishnan, S.; Beigel, Y.; Gotto, A.M. Jr.

1986-01-01

As assessed by molecular sieve chromatography and quantitation by a specific radioimmunoassay, apoA-IV is associated in plasma with the triglyceride-rich lipoproteins, to a high density lipoprotein (HDL) subfraction of smaller size than HDL3, and to the plasma lipoprotein-free fraction (LFF). In this study, the turnover of apoA-IV associated to the triglyceride-rich lipoproteins, HDL and LFF was investigated in vivo in normal volunteers. Human apoA-IV isolated from the thoracic duct lymph chylomicrons was radioiodinated and incubated with plasma withdrawn from normal volunteers after a fatty meal. Radioiodinated apoA-IV-labeled triglyceride-rich lipoproteins, HDL, and LFF were then isolated by chromatography on an AcA 34 column. Shortly after the injection of the radioiodinated apoA-IV-labeled triglyceride-rich lipoproteins, most of the radioactivity could be recovered in the HDL and LFF column fractions. On the other hand, when radioiodinated apoA-IV-labeled HDL or LFF were injected, the radioactivity remained with the originally injected fractions at all times. The residence time in plasma of 125 I-labeled apoA-IV, when injected in association with HDL or LFF, was 1.61 and 0.55 days, respectively. When 125 I-labeled apoA-IV was injected as a free protein, the radioactivity distributed rapidly among the three plasma pools in proportion to their mass. The overall fractional catabolic rate of apoA-IV in plasma was measured in the three normal subjects and averaged 1.56 pools per day. The mean degradation rate of apoA-IV was 8.69 mg/kg X day

Chemical nature of implant-derived titanium(IV) ions in synovial fluid

International Nuclear Information System (INIS)

Silwood, Christopher J.L.; Grootveld, Martin

2005-01-01

Previous investigations have indicated a deleterious leakage of Ti(III) and/or Ti(IV) species from Ti-Al-V alloy joint prostheses into adjacent tissue, synovium or synovial fluid (SF) in vivo. In view of the importance of the particular chemical nature of such complexes in determining their biological activity, we have employed high field proton ( 1 H) NMR spectroscopy to 'speciate' Ti(IV) in inflammatory SF. Treatment of osteoarthritic SF samples with increasing concentrations of Ti(IV) (0.10-1.03 mM [TiO(C 2 O 4 ) 2 ] 2- ) gave rise to a specific broadening of the citrate proton resonances, indicating that this bioavailable oxygen-donor ligand plays an important role in complexing implant-derived Ti(IV). 1 H NMR analysis of Ti(IV)-loaded SF samples subsequently treated with a large excess of ascorbate (0.05 M) showed that this added Ti(IV) chelator was only poorly effective in removing this metal ion from Ti(IV)-citrate/Ti(IV)-oxycitrate complexes. The results obtained here provide evidence for complexation of the low-molecular-mass (non-protein-bound) fraction of implant-derived Ti(IV) by citrate in vivo

Functional characterization of the role of the PilG in Xylella fastidiosa

Science.gov (United States)

Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in the Pil-Chp operon involving signal transduction pathways. To elucidate the role of pilG in twitching motility and pathogenicity of X. fastidiosa, phenotypes of wild type, a pilG-mutant, and a complementary strain we...

Hepatic imaging in stage IV-S neuroblastoma

International Nuclear Information System (INIS)

Franken, E.A. Jr.; Smith, W.L.; Iowa Univ., Iowa City; Cohen, M.D.; Kisker, C.T.; Platz, C.E.

1986-01-01

Stage IV-S neuroblastoma describes a group of infants with tumor spread limited to liver, skin, or bone marrow. Such patients, who constitute about 25% of affected infants with neuroblastoma, may expect spontaneous tumor remission. We report 18 infants with Stage IV-S neuroblastoma, 83% of whom had liver involvement. Imaging investigations included Technetium 99m sulfur colloid scan, ultrasound, and CT. Two patterns of liver metastasis were noted: ill-defined nodules or diffuse tumor throughout the liver. Distinction of normal and abnormal liver with diffuse type metastasis could be quite difficult, particularly with liver scans. We conclude that patients with Stage IV-S neuroblastoma have ultrasound or CT examination as an initial workup, with nuclear medicine scans reserved for followup studies. (orig.)

Thermodynamic data for predicting concentrations of Th(IV), U(IV), Np(IV), and Pu(IV) in geologic environments

Energy Technology Data Exchange (ETDEWEB)

Rai, Dhanpat; Roa, Linfeng; Weger, H.T.; Felmy, A.R. [Battelle, Pacific Northwest National Laboratory (PNNL) (United States); Choppin, G.R. [Florida State University (United States); Yui, Mikazu [Waste Isolation Research Division, Tokai Works, Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

1999-01-01

This report provides thermodynamic data for predicting concentrations of Th(IV), U(IV), Np(IV), and Pu(IV) in geologic environments, and contributes to an integration of the JNC chemical thermodynamic database, JNC-TDB (previously PNC-TDB), for the performance analysis of geological isolation system for high-level radioactive wastes. Thermodynamic data for the formation of complexes or compounds with hydroxide, chloride, fluoride, carbonate, nitrate, sulfate and phosphate are discussed in this report. Where data for specific actinide(IV) species was lacking, the data were selected based on chemical analogy to other tetravalent actinides. In this study, the Pitzer ion-interaction model is used to extrapolate thermodynamic constants to zero ionic strength at 25degC. (author)

viking: identification and characterization of a second type IV collagen in Drosophila.

Science.gov (United States)

Yasothornsrikul, S; Davis, W J; Cramer, G; Kimbrell, D A; Dearolf, C R

1997-10-01

We have taken an enhancer trap approach to identify genes that are expressed in hematopoietic cells and tissues of Drosophila. We conducted a molecular analysis of two P-element insertion strains that have reporter gene expression in embryonic hemocytes, strain 197 and vikingICO. This analysis has determined that viking encodes a collagen type IV gene, alpha2(IV). The viking locus is located adjacent to the previously described DCg1, which encodes collagen alpha1(IV), and in the opposite orientation. The alpha2(IV) and alpha1(IV) collagens are structurally very similar to one another, and to vertebrate type IV collagens. In early development, viking and DCg1 are transcribed in the same tissue-specific pattern, primarily in the hemocytes and fat body cells. Our results suggest that both the alpha1 and alpha2 collagen IV chains may contribute to basement membranes in Drosophila. This work also provides the foundation for a more complete genetic dissection of collagen type IV molecules and their developmental function in Drosophila.

About the structure and stability of complex carbonates of thorium (IV), cerium (IV), zirconium (IV), hafnium (IV)

International Nuclear Information System (INIS)

Dervin, Jacqueline

1972-01-01

This research thesis addressed the study of complex carbonates of cations of metals belonging to the IV A column, i.e. thorium (IV), zirconium (IV), hafnium (IV), and also cerium (IV) and uranium (VI), and more particularly focused on ionic compounds formed in solution, and also on the influence of concentration and nature of cations on stability and nature of the formed solid. The author first presents methods used in this study, discusses their precision and scope of validity. She reports the study of the formation of different complex ions which have been highlighted in solution, and the determination of their formation constants. She reports the preparation and study of the stability domain of solid complexes. The next part reports the use of thermogravimetric analysis, IR spectrometry, and crystallography for the structural study of these compounds

Active phytochemicals of Pueraria tuberosa for DPP-IV inhibition: in silico and experimental approach.

Science.gov (United States)

Srivastava, Shivani; Shree, Priya; Tripathi, Yamini Bhusan

2017-01-01

We had earlier reported that the extract of Pueraria tuberosa significantly inhibits DPP-IV enzyme, resulting in glucose tolerance response in rats. In this study, we have explored the active phytochemicals responsible for this potential. The results have been validated in both fasting and postprandial states in the plasma of normal rats and also in fasting blood and intestinal homogenates of diabetic models. Pueraria tuberosa water extract (PTWE) was administered to normal Charles Foster rats for 35 days and to diabetic model (65 mg/kg bw) for 10 days. After treatments, oral glucose tolerance test (OGTT) and insulin was done for 90 min, and the changes in the levels of GLP-1, GIP, and DPP-IV activities were monitored in fasting and postprandial states. In the case of the diabetic model, DPP-IV activity was measured in intestinal homogenate and basal insulin in plasma. The components of PTWE were analyzed via HPLC-MS based on their chemical formula, molecular mass, and retention time. Using the molecular docking study, we have selected the top five components having strong binding energy with DPP-IV. The increase in secretion of GLP-1 and GIP was significantly higher in the postprandial state when compared to fasting condition. GLP-1 plasma concentration increased by 5.8 and 2.9 folds and GIP increased by 8.7 and 2.4 folds in PTWE and control rats, respectively. In contrast, the postprandial decrease in DPP-IV specific activities was recorded at 2.3 and 1.4 folds. The response in OGTT and insulin was also consistent with these changes. In comparison to diabetic controls, PTWE-administered rats showed decreased DPP-IV activity in the intestine, leading to enhanced basal insulin concentration. Through molecular docking, we found Puerarone and Robinin to be the most potential phytochemicals of PTWE for DPP-IV inhibition. Binding energy (kcal/mol) and dissociation constant (pM) of Robinin with DPP-IV protein were found to be 7.543 and 2,957,383.75, respectively

Chromatographic studies of thorium(IV) and its extraction from monazite sand

International Nuclear Information System (INIS)

Bandyopadhyay, Arup; Roy, Uday Sankar

1998-01-01

A simple, rapid and selective method has been developed for reversed phase extraction chromatographic studies of Th IV with high molecular mass monocarboxylic acid (C 15 -C 16 ), SRS-100 as a stationary phase on a column of silica gel. Quantitative extraction of Th IV has been achieved in the pH range 4.8-5.5. The extracted Th IV has been stripped with 1:1 (v/v) mixture of 0.2 M HNO 3 and 0.2 M NaNO 3 and estimated spectrophotometrically. The effect of variables as pH, stripping agents, flow rate on extraction and elution have been studied. Th IV has been separated from various commonly associated elements in binary and synthetic multicomponent mixtures. The method has been applied successfully for the extraction of thorium from monazite sand. (author)

Molecular basis of usher pore gating in Escherichia coli pilus biogenesis.

Science.gov (United States)

Volkan, Ender; Kalas, Vasilios; Pinkner, Jerome S; Dodson, Karen W; Henderson, Nadine S; Pham, Thieng; Waksman, Gabriel; Delcour, Anne H; Thanassi, David G; Hultgren, Scott J

2013-12-17

Extracellular fibers called chaperone-usher pathway pili are critical virulence factors in a wide range of Gram-negative pathogenic bacteria that facilitate binding and invasion into host tissues and mediate biofilm formation. Chaperone-usher pathway ushers, which catalyze pilus assembly, contain five functional domains: a 24-stranded transmembrane β-barrel translocation domain (TD), a β-sandwich plug domain (PLUG), an N-terminal periplasmic domain, and two C-terminal periplasmic domains (CTD1 and 2). Pore gating occurs by a mechanism whereby the PLUG resides stably within the TD pore when the usher is inactive and then upon activation is translocated into the periplasmic space, where it functions in pilus assembly. Using antibiotic sensitivity and electrophysiology experiments, a single salt bridge was shown to function in maintaining the PLUG in the TD channel of the P pilus usher PapC, and a loop between the 12th and 13th beta strands of the TD (β12-13 loop) was found to facilitate pore opening. Mutation of the β12-13 loop resulted in a closed PapC pore, which was unable to efficiently mediate pilus assembly. Deletion of the PapH terminator/anchor resulted in increased OM permeability, suggesting a role for the proper anchoring of pili in retaining OM integrity. Further, we introduced cysteine residues in the PLUG and N-terminal periplasmic domains that resulted in a FimD usher with a greater propensity to exist in an open conformation, resulting in increased OM permeability but no loss in type 1 pilus assembly. These studies provide insights into the molecular basis of usher pore gating and its roles in pilus biogenesis and OM permeability.

Synthesis, molecular structure and magnetic properties of a rhenium(IV) compound with catechol

Science.gov (United States)

Cuevas, A.; Geis, L.; Pintos, V.; Chiozzone, R.; Sanchíz, J.; Hummert, M.; Schumann, H.; Kremer, C.

2009-03-01

A novel Re(IV) complex containing catechol as ligand has been prepared and characterized. The crystal structure of (HNEt 3)(NBu 4)[ReCl 4(cat)]·H 2cat was determined. The rhenium ion presents a distorted octahedral geometry, being bonded to a bidentate catecholate group and four chloride anions. The magnetic properties of the complex were studied, a /2 D/ (the energy gap between ±3/2 and ±1/2 Kramers doublets) value of 190(10) cm -1. This is the largest /2 D/ value reported for Re(IV) up to now.

Some oxozirconium(IV) compounds

Energy Technology Data Exchange (ETDEWEB)

Paul, R C; Gupta, S K; Parmar, S S; Vasisht, S K [Punjab Univ., Chandigarh (India). Dept. of Chemistry

1976-01-01

Some new oxozirconium(IV) complexes, ZrO(An)/sub 2/, ZrO(Gly)/sub 2/, ZrO(HSal)/sub 2/, ZrO(HPth)/sub 2/, ZrO(Pic)/sub 2/(HPic)/sub 2/, and ZrO(Quin)/sub 2/(HQuin)/sub 2/ have been isolated from the reactions of ZrO(CH/sub 3/COO)/sub 2/CH/sub 3/COOH with anthranilic acid (HAn), glycine (HGly), salicylic acid (H/sub 2/Sal), phthalic acid (H/sub 2/Pth), picolinic acid (HPic), and 8-quinolinol (HQuin) respectively. Their important infrared bands and wherever possible molar conductance and molecular weight have been reported.

Carboxylate derivatives of tributyltin (IV) complexes as anticancer and antileishmanial agents.

Science.gov (United States)

Waseem, Durdana; Butt, Arshad Farooq; Haq, Ihsan-Ul; Bhatti, Moazzam Hussain; Khan, Gul Majid

2017-04-04

Tributyltin (IV) compounds are promising candidates for drug development. In the current study, we evaluated in-vitro and in-silico profile of carboxylate derivatives of tributyltin (IV) complexes. ADMET and drug-likeliness properties were predicted using MetaPrint2D React, preADMET, SwissADME and Molsoft tools. SwissTargetPrediction predicted molecular targets for compounds. In-vitro bioactivity was evaluated by quantifying cytotoxicity against HepG2, THP-1 cell lines, isolated lymphocytes and leishmania promastigotes as well as measuring protein kinase (PK) inhibition activity. Results indicate partial compliance of compounds with drug-likeliness rules. Ch-409 complies with WDI and Lipinski rules. ADMET profile prediction shows strong plasma protein binding except for Ch-409, low to high GI absorption and BBB penetration (C brain /C blood  = 0.942-11; caco-2 cells permeability 20.13-26.75 nm/sec), potential efflux by P-glycoprotein, metabolism by CYP3A4, medium inhibition of hERG, mutagenicity and capacity to be detoxified by glutathionation and glucuronidation. Molecular targets include proteases, enzymes, membrane receptors, transporters and ion channels where Ch-409 targets membrane receptors only. Compounds are significantly (p tributyltin (IV) complexes possess significant antileishmanial and cytotoxic potential. These are promising compounds for the development of antileishmanial and anticancer drugs. Graphical Abstract Carboxylate derivatives of tributyltin (IV) complexes as anticancer and antileishmanial agents.

Redefining the PF06864 Pfam family based on Burkholderia pseudomallei PilO2(Bp S-SAD crystal structure.

Directory of Open Access Journals (Sweden)

Patricia Lassaux

Full Text Available Type IV pili are surface-exposed filaments and bacterial virulence factors, represented by the Tfpa and Tfpb types, which assemble via specific machineries. The Tfpb group is further divided into seven variants, linked to heterogeneity in the assembly machineries. Here we focus on PilO2(Bp, a protein component of the Tfpb R64 thin pilus variant assembly machinery from the pathogen Burkholderia pseudomallei. PilO2(Bp belongs to the PF06864 Pfam family, for which an improved definition is presented based on newly derived Hidden Markov Model (HMM profiles. The 3D structure of the N-terminal domain of PilO2(Bp (N-PilO2(Bp, here reported, is the first structural representative of the PF06864 family. N-PilO2(Bp presents an actin-like ATPase fold that is shown to be present in BfpC, a different variant assembly protein; the new HMM profiles classify BfpC as a PF06864 member. Our results provide structural insight into the PF06864 family and on the Type IV pili assembly machinery.

Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.

Science.gov (United States)

Goudarzi, Mehdi; Goudarzi, Hossein; Sá Figueiredo, Agnes Marie; Udo, Edet E; Fazeli, Maryam; Asadzadeh, Mohammad; Seyedjavadi, Sima Sadat

2016-01-01

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran. A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing. The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1%) to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml) had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3%) were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%), ST239-SCCmec III/t037 (17.1%), and ST291-SCCmec IV/t030 (8.6%). The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.

Sensitive method for the determination of different S(IV) species in cloud and fog water.

Science.gov (United States)

Lammel, G

1996-08-01

Suppressed ion chromatography has been applied to the determination of S(IV) species in cloud and fog water in the range 0.012-2.4 mg S(IV)-S/L. The samples have been preserved prior to storage and S(IV) species have been determined as hydroxy methanesulfonate (HMS) together with the low molecular weight carboxylic acid anions, formate and acetate. Samples have been divided and treated differently such that total S(IV) as well as the non-oxidizable fraction of S(IV) (as given by the reactivity with H(2)O(2), added in surplus) could be determined. The difference between the two corresponds to the S(IV) fraction subjected to oxididation, which is of paramount interest in cloud and fogwater chemistry.

Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction

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NM Coelho

2010-06-01

Full Text Available Considering the structural role of type IV collagen (Col IV in the assembly of the basement membrane (BM and the perspective of mimicking its organization for vascular tissue engineering purposes, we studied the adsorption pattern of this protein on model hydrophilic (clean glass and hydrophobic trichloro(octadecylsilane (ODS surfaces known to strongly affect the behavior of other matrix proteins. The amount of fluorescently labeled Col IV was quantified showing saturation of the surface for concentration of the adsorbing solution of about 50μg/ml, but with approximately twice more adsorbed protein on ODS. AFM studies revealed a fine – nearly single molecular size – network arrangement of Col IV on hydrophilic glass, which turns into a prominent and growing polygonal network consisting of molecular aggregates on hydrophobic ODS. The protein layer forms within minutes in a concentration-dependent manner. We further found that human umbilical vein endothelial cells (HUVEC attach less efficiently to the aggregated Col IV (on ODS, as judged by the significantly altered cell spreading, focal adhesions formation and the development of actin cytoskeleton. Conversely, the immunofluorescence studies for integrins revealed that the fine Col IV network formed on hydrophilic substrata is better recognized by the cells via both α1 and α2 heterodimers which support cellular interaction, apart from these on hydrophobic ODS where almost no clustering of integrins was observed.

Ab initio I-V characteristics of short C-20 chains

DEFF Research Database (Denmark)

Roland, C.; Larade, B.; Taylor, Jeremy Philip

2002-01-01

We have calculated the I-V characteristics of short chains of C-20 molecular cages between Al and Au leads with an ab initio formalism. The results indicate that a linear chain of such molecules acts primarily as metallic nanowires. The transmission, however, depends sensitively both...

Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli*

Science.gov (United States)

Kolappan, Subramania; Ng, Dixon; Yang, Guixiang; Harn, Tony; Craig, Lisa

2015-01-01

Type IV pili are extracellular polymers of the major pilin subunit. These subunits are held together in the pilus filament by hydrophobic interactions among their N-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. Type IV pilus assembly involves a conserved group of proteins that span the envelope of Gram-negative bacteria. Among these is a set of minor pilins, so named because they share their hydrophobic N-terminal polymerization/membrane anchor segment with the major pilins but are much less abundant. Minor pilins influence pilus assembly and retraction, but their precise functions are not well defined. The Type IV pilus systems of enterotoxigenic Escherichia coli and Vibrio cholerae are among the simplest of Type IV pilus systems and possess only a single minor pilin. Here we show that the enterotoxigenic E. coli minor pilins CofB and LngB are required for assembly of their respective Type IV pili, CFA/III and Longus. Low levels of the minor pilins are optimal for pilus assembly, and CofB can be detected in the pilus fraction. We solved the 2.0 Å crystal structure of N-terminally truncated CofB, revealing a pilin-like protein with an extended C-terminal region composed of two discrete domains connected by flexible linkers. The C-terminal region is required for CofB to initiate pilus assembly. We propose a model for CofB-initiated pilus assembly with implications for understanding filament growth in more complex Type IV pilus systems as well as the related Type II secretion system. PMID:26324721

The Prognostic Influence of BRAF Mutation and other Molecular, Clinical and Laboratory Parameters in Stage IV Colorectal Cancer.

Science.gov (United States)

Karadima, Maria L; Saetta, Angelica A; Chatziandreou, Ilenia; Lazaris, Andreas C; Patsouris, Efstratios; Tsavaris, Nikolaos

2016-10-01

Our aim was to evaluate the predictive and prognostic influence of BRAF mutation and other molecular, clinical and laboratory parameters in stage IV colorectal cancer (CRC). 60 patients were included in this retrospective analysis, and 17 variables were examined for their relation with treatment response and survival. KRAS mutation was identified in 40.3 % of cases, BRAF and PIK3CA in 8.8 % and 10.5 % respectively. 29.8 % of patients responded to treatment. Median survival time was 14.3 months. Weight loss, fever, abdominal metastases, blood transfusion, hypoalbuminaimia, BRAF and PIK3CA mutations, CRP and DNA Index were associated with survival. In multivariate analysis, male patients had 3.8 times higher probability of response, increased DNA Index was inversely correlated with response and one unit raise of DNA Index augmented 6 times the probability of death. Our findings potentiate the prognostic role of BRAF, PIK3CA mutations and ploidy in advanced CRC.

Molecular HIV screening.

Science.gov (United States)

Bourlet, Thomas; Memmi, Meriam; Saoudin, Henia; Pozzetto, Bruno

2013-09-01

Nuclear acid testing is more and more used for the diagnosis of infectious diseases. This paper focuses on the use of molecular tools for HIV screening. The term 'screening' will be used under the meaning of first-line HIV molecular techniques performed on a routine basis, which excludes HIV molecular tests designed to confirm or infirm a newly discovered HIV-seropositive patient or other molecular tests performed for the follow-up of HIV-infected patients. The following items are developed successively: i) presentation of the variety of molecular tools used for molecular HIV screening, ii) use of HIV molecular tools for the screening of blood products, iii) use of HIV molecular tools for the screening of organs and tissue from human origin, iv) use of HIV molecular tools in medically assisted procreation and v) use of HIV molecular tools in neonates from HIV-infected mothers.

(N-Benzyl-N-isopropyl-dithio-carbamato)chloridodiphenyl-tin(IV).

Science.gov (United States)

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Ng, Seik Weng; Tiekink, Edward R T

2010-08-11

The Sn(IV) atom in the title organotin dithio-carbamate, [Sn(C(6)H(5))(2)(C(11)H(14)NS(2))Cl], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl and two ispo-C atoms of the Sn-bound phenyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square-pyramidal and trigonal-bipyramidal with a slight tendency towards the latter. The formation of close intra-molecular C-H⋯Cl and C-H⋯S contacts precludes the Cl and S atoms from forming significant inter-molecular contacts. The presence of C-H⋯π contacts leads to the formation of supra-molecular arrays that stack along the b axis.

[Molecular characterization of heterozygous beta-thalassemia in Lanzarote, Spain].

Science.gov (United States)

Calvo-Villas, José Manuel; de la Iglesia Iñigo, Silvia; Ropero Gradilla, Paloma; Zapata Ramos, María Francisca; Cuesta Tovar, Jorge; Sicilia Guillén, Francisco

2008-04-05

The aim of this study was to determine the molecular defects of heterozygous beta thalassaemia and to ascertain their distribution in Lanzarote. Molecular characterization was achieved by real time polymerase chain reaction (RT-PCR LightCycler, Roche), PCR-ARMS (PCR-amplification reaction mutations system) and DNA sequencing on an automated DNA sequencer. Two hundred forty-three heterozygous beta thalassaemia carriers were included between July 1991 and February 2007. RT-PCR detected the molecular defect in 81% of the beta thalassaemia chromosomes analyzed [113 codon CD 39 (C --> T); 41 IVS-1-nt-110 (G --> A), 25 IVS 1-nt-1 (G --> A) and 19 IVS 1-nt-6 (T --> C)]. The remaining 12 molecular defects included the deletion 619 bp (7.8%) and the mutations -28 (A --> G), IVS1-nt-2 (T --> G), CD 41/42 (-TTCT), CD 8/9 (+G), CD 51 (-C), CD 22 (G --> T) and CD 24 (T --> A), CD 67 (-TG) and the novel mutation CD 20/21-TGGA. The distribution of the mutations is similar to that found in the Mediterranean area. The increasing migratory flow received in the Canary Islands may explain the emergence of new mutations not reported before in our area.

O tom, tshto ushlo : [luuletused] / Aleksander Suuman ; Lühibiograafia: T. L. [Toomas Liiv

Index Scriptorium Estoniae

Suuman, Aleksander, 1927-2003

1999-01-01

Sisu: O tom, tshto ushlo ; "Gde-to dolzhno zhe bõt stshastje..." ; "Serõje lessa..." ; Zholtogolovõ ; "Teh iv serebristõh nelzja oboiti..." ; "Vzroslõje vkladtshinu pili..." ; "U nas tut, za Giperborejem..." / tlk. Svetlan Semenenko ; Odno hotshu skazat ; Los idjot / tlk. Boris Baljasnõi.Orig.: "Kusagil peab olema õnn..." ; Kullerkupud ; "Ei hõbepajust ma mööduda saand..." ; "Meil siin Hüperboreas..." ;

Identification of type IV collagen exposure as a molecular imaging target for early detection of thoracic aortic dissection

Science.gov (United States)

Xu, Ke; Xu, Chen; Zhang, Yanzhenzi; Qi, Feiran; Yu, Bingran; Li, Ping; Jia, Lixin; Li, Yulin; Xu, Fu-jian; Du, Jie

2018-01-01

Thoracic aortic dissection (TAD) is an aggressive and life-threatening vascular disease and there is no effective means of early diagnosis of dissection. Type IV collagen (Col-IV) is a major component of the sub-endothelial basement membrane, which is initially exposed followed by endothelial injury as early-stage event of TAD. So, we want to build a noninvasive diagnostic method to detect early dissection by identifying the exposed Col-IV via MRI. Methods: Col-IV-targeted magnetic resonance/ fluorescence dual probe (Col-IV-DOTA-Gd-rhodamine B; CDR) was synthesized by amide reaction and coordination reaction. Flow cytometry analysis was used to evaluate the cell viability of SMC treated with CDR and fluorescence assays were used to assess the Col-IV targeting ability of CDR in vitro. We then examined the sensitivity and specificity of CDR at different stages of TAD via MRI and bioluminescence imaging in vivo. Results: The localization of Col-IV (under the intima) was observed by histology images. CDR bound specifically to Col-IV-expressing vascular smooth muscle cells and BAPN-induced dissected aorta. The CDR signal was co-detected by magnetic resonance imaging (MRI) and bioluminescence imaging as early as 2 weeks after BAPN administration (pre-dissection stage). The ability to detect rupture of dissected aorta was indicated by a strong normalized signal enhancement (NSE) in vivo. Moreover, NSE was negatively correlated with the time of dissection rupture after BAPN administration (r2 = 0.8482). Conclusion: As confirmed by in vivo studies, the CDR can identify the exposed Col-IV in degenerated aorta to monitor the progress of aortic dissection from the early stage to the rupture via MRI. Thus, CDR-enhanced MRI proposes a potential method for dissection screening, and for monitoring disease progression and therapeutic response. PMID:29290819

Shapiro like steps reveals molecular nanomagnets’ spin dynamics

International Nuclear Information System (INIS)

Abdollahipour, Babak; Abouie, Jahanfar; Ebrahimi, Navid

2015-01-01

We present an accurate way to detect spin dynamics of a nutating molecular nanomagnet by inserting it in a tunnel Josephson junction and studying the current voltage (I-V) characteristic. The spin nutation of the molecular nanomagnet is generated by applying two circularly polarized magnetic fields. We demonstrate that modulation of the Josephson current by the nutation of the molecular nanomagnet’s spin appears as a stepwise structure like Shapiro steps in the I-V characteristic of the junction. Width and heights of these Shapiro-like steps are determined by two parameters of the spin nutation, frequency and amplitude of the nutation, which are simply tuned by the applied magnetic fields

[The detection of occurrence rate of genes coding capability to form pili binding in auto-strains of Escherichia coli].

Science.gov (United States)

Ivanova, E I; Popkova, S M; Dzhioev, Iu P; Rakova, E B; Dolgikh, V V; Savel'kaeva, M V; Nemchenko, U M; Bukharova, E V; Serdiuk, L V

2015-01-01

E. coli is a commensal of intestine of the vertebrata. The exchange of genetic material of different types of bacteria between themselves and with other representatives of family of Enterobacteriaceae in intestinal ecosystem results in development of types of normal colibacillus with genetic characteristics of pathogenicity that can serve as a theoretical substantiation to attribute such strains to pathobionts. The entero-pathogenic colibacillus continues be an important cause of diarrhea in children in developing countries. The gene responsible for formation of pili binding is a necessary condition for virulence of entero-pathogenic colibacillus. The polymerase chain reaction was applied to examine 316 strains of different types of E. coli (normal, with weak enzyme activity and hemolytic activity) isolated from healthy children and children with functional disorders of gastro-intestinal tract for presence of genes coding capability to form pill binding. The presence of this gene in different biochemical types of E. coli permits to establish the fact of formation of reservoir of pathogenicity in indigent microbiota of intestinal biocenosis.

The Type IV Pilus Assembly ATPase PilB of Myxococcus xanthus Interacts with the Inner Membrane Platform Protein PilC and the Nucleotide-binding Protein PilM.

Science.gov (United States)

Bischof, Lisa Franziska; Friedrich, Carmen; Harms, Andrea; Søgaard-Andersen, Lotte; van der Does, Chris

2016-03-25

Type IV pili (T4P) are ubiquitous bacterial cell surface structures, involved in processes such as twitching motility, biofilm formation, bacteriophage infection, surface attachment, virulence, and natural transformation. T4P are assembled by machinery that can be divided into the outer membrane pore complex, the alignment complex that connects components in the inner and outer membrane, and the motor complex in the inner membrane and cytoplasm. Here, we characterize the inner membrane platform protein PilC, the cytosolic assembly ATPase PilB of the motor complex, and the cytosolic nucleotide-binding protein PilM of the alignment complex of the T4P machinery ofMyxococcus xanthus PilC was purified as a dimer and reconstituted into liposomes. PilB was isolated as a monomer and bound ATP in a non-cooperative manner, but PilB fused to Hcp1 ofPseudomonas aeruginosaformed a hexamer and bound ATP in a cooperative manner. Hexameric but not monomeric PilB bound to PilC reconstituted in liposomes, and this binding stimulated PilB ATPase activity. PilM could only be purified when it was stabilized by a fusion with a peptide corresponding to the first 16 amino acids of PilN, supporting an interaction between PilM and PilN(1-16). PilM-N(1-16) was isolated as a monomer that bound but did not hydrolyze ATP. PilM interacted directly with PilB, but only with PilC in the presence of PilB, suggesting an indirect interaction. We propose that PilB interacts with PilC and with PilM, thus establishing the connection between the alignment and the motor complex. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Book review, Ominis e bestias in su campidanu de iossu, Marcello Furio Pili

Directory of Open Access Journals (Sweden)

Manuel Graziani

2011-12-01

Full Text Available Ciò che ci ha più incuriosito di questa pubblicazione è il sottotitolo “Il rapporto tra uomini e animali nelle attività lavorative del passato e del presente”. L’autore Marcello Furio Pili, pur riconoscendo una sorta di omologazione della società umana a seguito della rivoluzione industriale, parte dal presupposto storico dell’unicità del rapporto con gli animali che da sempre è un tratto distintivo del popolo sardo. La ricerca si concentra su cinque paesi del Basso Campidano: Nuraminis, Monastir, Ussana, San Sperate e Sestu, ognuno trattato in una veste monografica a sé stante ma con la medesima struttura editoriale e contenutistica. Cinque paesi di stampo rurale la cui economia, almeno fino ai primi decenni del ’900, “era fondata essenzialmente sull’utilizzo della terra, agricoltura e allevamento di bestiame quindi, e quasi ogni altra attività ruotava intorno alla sfera del rus, della campagna”. Grande spazio viene dedicato, infatti, agli animali (bovini, equini, caprini, suidi, canidi, felini, leporidi, roditori, uccelli, insetti, ecc. che vengono classificati secondo la tassonomia risalente al Sistema della Natura di Linneo, con ovini e caprini accorpati in un unico paragrafo seguendo la moderna classificazione che li inserisce entrambi nella sottofamiglia Caprinae.Il grande formato del libro (21 × 29 cm e la presenza di numerose foto di animali, vegetazione e, soprattutto, vecchi strumenti di lavoro, rendono ancor più interessante questa ricerca che, pur essendo sostanzialmente di carattere antropologico, culturale e linguistico, è molto centrata sul rapporto uomo-animale: “Il rapporto con gli animali, in un modo o nell’altro, era, per quasi tutti i componenti della comunità, costante, necessario, inevitabile.”.

uPARAP/endo180 directs lysosomal delivery and degradation of collagen IV

DEFF Research Database (Denmark)

Kjøller, Lars; Engelholm, Lars H; Høyer-Hansen, Maria

2004-01-01

Collagen turnover is crucial for tissue homeostasis and remodeling and pathological processes such as cancer invasion, but the underlying molecular mechanisms are poorly understood. A major pathway appears to be internalization and degradation by fibroblasts. We now show that the endocytic...... transmembrane glycoprotein urokinase plasminogen activator receptor-associated protein (uPARAP/endo180) directs collagen IV for lysosomal delivery and degradation. In wild-type fibroblasts, fluorescently labeled collagen IV was first internalized into vesicular structures with diffuse fluorescence eventually...... appearing uniformly within the wild-type cells after longer incubation times. In these cells, some collagen-containing vesicles were identified as lysosomes by staining for LAMP-1. In contrast, collagen IV remained extracellular and associated with fiber-like structures on uPARAP/endo180-deficient...

Oxovanadium(IV)-catalysed oxidation of dibenzothiophene and 4,6-dimethyldibenzothiophene.

Science.gov (United States)

Ogunlaja, Adeniyi S; Chidawanyika, Wadzanai; Antunes, Edith; Fernandes, Manuel A; Nyokong, Tebello; Torto, Nelson; Tshentu, Zenixole R

2012-12-07

The reaction between [V(IV)OSO(4)] and the tetradentate N(2)O(2)-donor Schiff base ligand, N,N-bis(o-hydroxybenzaldehyde)phenylenediamine (sal-HBPD), obtained by the condensation of salicylaldehyde and o-phenylenediamine in a molar ratio of 2 : 1 respectively, resulted in the formation of [V(IV)O(sal-HBPD)]. The molecular structure of [V(IV)O(sal-HBPD)] was determined by single crystal X-ray diffraction, and confirmed the distorted square pyramidal geometry of the complex with the N(2)O(2) binding mode of the tetradentate ligand. The formation of the polymer-supported p[V(IV)O(sal-AHBPD)] proceeded via the nitrosation of sal-HBPD, followed by the reduction with hydrogen to form an amine group that was then linked to Merrifield beads followed by the reaction with [V(IV)OSO(4)]. XPS and EPR were used to confirm the presence of oxovanadium(IV) within the beads. The BET surface area and porosity of the heterogeneous catalyst p[V(IV)O(sal-AHBPD)] were found to be 6.9 m(2) g(-1) and 180.8 Å respectively. Microanalysis, TG, UV-Vis and FT-IR were used for further characterization of both [V(IV)O(sal-HBPD)] and p[V(IV)O(sal-AHBPD)]. Oxidation of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was investigated using [V(IV)O(sal-HBPD)] and p[V(IV)O(sal-AHBPD)] as catalysts. Progress for oxidation of these model compounds was monitored with a gas chromatograph fitted with a flame ionization detector. The oxidation products were characterized using gas chromatography-mass spectrometry, microanalysis and NMR. Dibenzothiophene sulfone (DBTO(2)) and 4,6-dimethyldibenzothiophene sulfone (4,6-DMDBTO(2)) were found to be the main products of oxidation. Oxovanadium(IV) Schiff base microspherical beads, p[V(IV)O(sal-AHBPD)], were able to catalyse the oxidation of sulfur in dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) to a tune of 88.0% and 71.8% respectively after 3 h at 40 °C. These oxidation results show promise for potential application

The pilus usher controls protein interactions via domain masking and is functional as an oligomer.

Science.gov (United States)

Werneburg, Glenn T; Henderson, Nadine S; Portnoy, Erica B; Sarowar, Samema; Hultgren, Scott J; Li, Huilin; Thanassi, David G

2015-07-01

The chaperone-usher (CU) pathway assembles organelles termed pili or fimbriae in Gram-negative bacteria. Type 1 pili expressed by uropathogenic Escherichia coli are prototypical structures assembled by the CU pathway. Biogenesis of pili by the CU pathway requires a periplasmic chaperone and an outer-membrane protein termed the usher (FimD). We show that the FimD C-terminal domains provide the high-affinity substrate-binding site but that these domains are masked in the resting usher. Domain masking requires the FimD plug domain, which serves as a switch controlling usher activation. We demonstrate that usher molecules can act in trans for pilus biogenesis, providing conclusive evidence for a functional usher oligomer. These results reveal mechanisms by which molecular machines such as the usher regulate and harness protein-protein interactions and suggest that ushers may interact in a cooperative manner during pilus assembly in bacteria.

Nanoparticle-Supported Molecular Polymerization Catalysts

OpenAIRE

Amgoune, Abderramane; Krumova, Marina; Mecking, Stefan

2008-01-01

Homogeneous molecular catalysts are immobilzed in a well-defined fashion on individual silica nanoparticles with a narrow particle size distribution by covalent attachment. This synthetic methodology is demonstrated with modified salicylaldiminato-substituted titanium(IV) complexes incorporating a trimethoxysilane-terminated linker: dichloro-bis[κ2-N,O-6-(3-(trimethoxysilyl)propoxyphenylimino)-2-tert-butyl-phenolato]titanium(IV) (3) and dichlorobis[κ2-N,O-6-(4-(trimethoxysilyl)propoxy-2,3,5,6...

Shuttlecock-Shaped Molecular Rectifier: Asymmetric Electron Transport Coupled with Controlled Molecular Motion.

Science.gov (United States)

Ryu, Taekhee; Lansac, Yves; Jang, Yun Hee

2017-07-12

A fullerene derivative with five hydroxyphenyl groups attached around a pentagon, (4-HOC 6 H 4 ) 5 HC 60 (1), has shown an asymmetric current-voltage (I-V) curve in a conducting atomic force microscopy experiment on gold. Such molecular rectification has been ascribed to the asymmetric distribution of frontier molecular orbitals over its shuttlecock-shaped structure. Our nonequilibrium Green's function (NEGF) calculations based on density functional theory (DFT) indeed exhibit an asymmetric I-V curve for 1 standing up between two Au(111) electrodes, but the resulting rectification ratio (RR ∼ 3) is insufficient to explain the wide range of RR observed in experiments performed under a high bias voltage. Therefore, we formulate a hypothesis that high RR (>10) may come from molecular orientation switching induced by a strong electric field applied between two electrodes. Indeed, molecular dynamics simulations of a self-assembled monolayer of 1 on Au(111) show that the orientation of 1 can be switched between standing-up and lying-on-the-side configurations in a manner to align its molecular dipole moment with the direction of the applied electric field. The DFT-NEGF calculations taking into account such field-induced reorientation between up and side configurations indeed yield RR of ∼13, which agrees well with the experimental value obtained under a high bias voltage.

Serine-rich repeat proteins and pili promote Streptococcus agalactiae colonization of the vaginal tract.

Science.gov (United States)

Sheen, Tamsin R; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M; Doran, Kelly S

2011-12-01

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment.

Bioactive compounds from culinary herbs inhibit a molecular target for type 2 diabetes management, dipeptidyl peptidase IV.

Science.gov (United States)

Bower, Allyson M; Real Hernandez, Luis M; Berhow, Mark A; de Mejia, Elvira Gonzalez

2014-07-02

Greek oregano (Origanum vulgare), marjoram (Origanum majorana), rosemary (Rosmarinus officinalis), and Mexican oregano (Lippia graveolens) are concentrated sources of bioactive compounds. The aims were to characterize and examine extracts from greenhouse-grown or commercially purchased herbs for their ability to inhibit dipeptidyl peptidase IV (DPP-IV) and protein tyrosine phosphatase 1B (PTP1B), enzymes that play a role in insulin secretion and insulin signaling, respectively. Greenhouse herbs contained more polyphenols (302.7-430.1 μg of gallic acid equivalents/mg of dry weight of extract (DWE)) and flavonoids (370.1-661.4 μg of rutin equivalents/mg of DWE) compared to the equivalent commercial herbs. Greenhouse rosemary, Mexican oregano, and marjoram extracts were the best inhibitors of DPP-IV (IC₅₀=16, 29, and 59 μM, respectively). Commercial rosemary, Mexican oregano, and marjoram were the best inhibitors of PTP1B (32.4-40.9% at 500 μM). The phytochemicals eriodictyol, naringenin, hispidulin, cirsimaritin, and carnosol were identified by LC-ESI-MS as being present in greenhouse-grown Mexican oregano and rosemary. Computational modeling indicated that hispidulin, carnosol, and eriodictyol would have the best binding affinities for DPP-IV. Biochemically, the best inhibitors of DPP-IV were cirsimaritin (IC₅₀=0.43±0.07 μM), hispidulin (IC₅₀=0.49±0.06 μM), and naringenin (IC₅₀=2.5±0.29 μM). Overall, herbs contain several flavonoids that inhibit DPP-IV and should be investigated further regarding their potential in diabetes management.

Test Review: Advanced Clinical Solutions for WAIS-IV and WMS-IV

Science.gov (United States)

Chu, Yiting; Lai, Mark H. C.; Xu, Yining; Zhou, Yuanyuan

2012-01-01

The authors review the "Advanced Clinical Solutions for WAIS-IV and WMS-IV". The "Advanced Clinical Solutions (ACS) for the Wechsler Adult Intelligence Scale-Fourth Edition" (WAIS-IV; Wechsler, 2008) and the "Wechsler Memory Scale-Fourth Edition" (WMS-IV; Wechsler, 2009) was published by Pearson in 2009. It is a…

Direct complexonometric determination of thorium (IV), uranium (IV), neptunium (IV), plutonium (IV) by titration of diethylenetriaminepentaacetic acid with xylenol orange as indicator

International Nuclear Information System (INIS)

Rykov, A.G.; Piskunov, E.M.; Timofeev, G.A.

1975-01-01

The purpose of the present work was to develop a method of determining Th(IV), U(IV), Np(N) and Pu(IV) in acid solutions by titration with diethylenetriamine pentacetic acid, the indicator being xylenol orange. It has been established that Th, U, Np and Pu can be determined to within 0.5-1.5%. Th and U in quantities of tens of milligrams can be determined with greater accuracy, attaining hundredths of one per cent. During titration the determination is not hindered by singly- and doubly-charged metal ions, trivalent lanthanides and actinides, except plutonium. The proposed method can be used to determine U(IV) in the presence of considerable quantities of U(VI) and Np(IV) in the presence of Np(V). Total concentrations of uranium or neptunium are determined by reducing uranium (VI) or neptunium (V) by a standard method (for example, using metallic lead, cadmium or zinc amalgam) to the tetravalent state and applying the method described in the paper. (E.P.)

Comparative genomics of Geobacter chemotaxis genes reveals diverse signaling function

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Antommattei Frances M

2008-10-01

Full Text Available Abstract Background Geobacter species are δ-Proteobacteria and are often the predominant species in a variety of sedimentary environments where Fe(III reduction is important. Their ability to remediate contaminated environments and produce electricity makes them attractive for further study. Cell motility, biofilm formation, and type IV pili all appear important for the growth of Geobacter in changing environments and for electricity production. Recent studies in other bacteria have demonstrated that signaling pathways homologous to the paradigm established for Escherichia coli chemotaxis can regulate type IV pili-dependent motility, the synthesis of flagella and type IV pili, the production of extracellular matrix material, and biofilm formation. The classification of these pathways by comparative genomics improves the ability to understand how Geobacter thrives in natural environments and better their use in microbial fuel cells. Results The genomes of G. sulfurreducens, G. metallireducens, and G. uraniireducens contain multiple (~70 homologs of chemotaxis genes arranged in several major clusters (six, seven, and seven, respectively. Unlike the single gene cluster of E. coli, the Geobacter clusters are not all located near the flagellar genes. The probable functions of some Geobacter clusters are assignable by homology to known pathways; others appear to be unique to the Geobacter sp. and contain genes of unknown function. We identified large numbers of methyl-accepting chemotaxis protein (MCP homologs that have diverse sensing domain architectures and generate a potential for sensing a great variety of environmental signals. We discuss mechanisms for class-specific segregation of the MCPs in the cell membrane, which serve to maintain pathway specificity and diminish crosstalk. Finally, the regulation of gene expression in Geobacter differs from E. coli. The sequences of predicted promoter elements suggest that the alternative sigma factors �

Congenital bilateral neuroblastoma (stage IV-S): case report

International Nuclear Information System (INIS)

Lee, Jeong Hee; Lee, Hee Jung; Woo, Seong Ku; Lee, Sang Rak; Kim, Heung Sik

2002-01-01

Congenital neonatal neuroblastoma is not uncommon but bilateral adrenal neuroblastoma is rare, accounting for about ten percent of neuroblastomas in children. We report the US the MR findings of a stage IV-S congenital bilateral neuroblastoma occurring in a one-day-old neonate

Cyclic Di-GMP Binding by an Assembly ATPase (PilB2) and Control of Type IV Pilin Polymerization in the Gram-Positive Pathogen Clostridium perfringens.

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Hendrick, William A; Orr, Mona W; Murray, Samantha R; Lee, Vincent T; Melville, Stephen B

2017-05-15

The Gram-positive pathogen Clostridium perfringens possesses type IV pili (TFP), which are extracellular fibers that are polymerized from a pool of pilin monomers in the cytoplasmic membrane. Two proteins that are essential for pilus functions are an assembly ATPase (PilB) and an inner membrane core protein (PilC). Two homologues each of PilB and PilC are present in C. perfringens , called PilB1/PilB2 and PilC1/PilC2, respectively, along with four pilin proteins, PilA1 to PilA4. The gene encoding PilA2, which is considered the major pilin based on previous studies, is immediately downstream of the pilB2 and pilC2 genes. Purified PilB2 had ATPase activity, bound zinc, formed hexamers even in the absence of ATP, and bound the second messenger molecule cyclic di-GMP (c-di-GMP). Circular dichroism spectroscopy of purified PilC2 indicated that it retained its predicted degree of alpha-helical secondary structure. Even though no direct interactions between PilB2 and PilC2 could be detected in vivo or in vitro even in the presence of c-di-GMP, high levels of expression of a diguanylate cyclase from C. perfringens (CPE1788) stimulated polymerization of PilA2 in a PilB2- and PilC2-dependent manner. These results suggest that PilB2 activity is controlled by c-di-GMP levels in vivo but that PilB2-PilC2 interactions are either transitory or of low affinity, in contrast to results reported previously from in vivo studies of the PilB1/PilC1 pair in which PilC1 was needed for polar localization of PilB1. This is the first biochemical characterization of a c-di-GMP-dependent assembly ATPase from a Gram-positive bacterium. IMPORTANCE Type IV pili (TFP) are protein fibers involved in important bacterial functions, including motility, adherence to surfaces and host cells, and natural transformation. All clostridia whose genomes have been sequenced show evidence of the presence of TFP. The genetically tractable species Clostridium perfringens was used to study proteins involved in

Immobilization of Mo(IV) complex in hybrid matrix obtained via sol-gel technique

Energy Technology Data Exchange (ETDEWEB)

Marques, C.; Sousa, A.M.; Freire, C.; Neves, I.C.; Fonseca, A.M.; Silva, C.J.R

2003-10-06

A molybdenum(IV) complex, trans-bis-[1,2-bis(diphenylphosphino)ethane]-fluoro-(diazopropano) -molybdenum tetraphenylborate, [MoF(DIAZO)(dppe){sub 2}][BPh{sub 4}], was prepared and immobilized in a hybrid matrix synthesized by the sol-gel process. The host matrix, designated as U(500), is an organic-inorganic network material, classed as ureasil, that combines a reticulated siliceous backbone linked by short polyether-based segments. Urea bridges make the link between these two components, and the polymerization of silicate substituted terminal groups generates the inorganic network. The free Mo(IV) complex and all new materials were characterized by spectroscopic techniques (FT-IR and UV-Vis) and thermal analysis (DSC). The ionic conductivity of the resulting material was also studied. The results indicate that immobilized Mo(IV) complex has kept its solid-state structure, although there is evidence of inter-molecular interactions between the Mo(IV) complex and some groups/atoms of the hybrid host matrix.

Type IV pilins regulate their own expression via direct intramembrane interactions with the sensor kinase PilS.

Science.gov (United States)

Kilmury, Sara L N; Burrows, Lori L

2016-05-24

Type IV pili are important virulence factors for many pathogens, including Pseudomonas aeruginosa Transcription of the major pilin gene-pilA-is controlled by the PilS-PilR two-component system in response to unknown signals. The absence of a periplasmic sensing domain suggested that PilS may sense an intramembrane signal, possibly PilA. We suggest that direct interactions between PilA and PilS in the inner membrane reduce pilA transcription when PilA levels are high. Overexpression in trans of PilA proteins with diverse and/or truncated C termini decreased native pilA transcription, suggesting that the highly conserved N terminus of PilA was the regulatory signal. Point mutations in PilA or PilS that disrupted their interaction prevented autoregulation of pilA transcription. A subset of PilA point mutants retained the ability to interact with PilS but could no longer decrease pilA transcription, suggesting that interaction between the pilin and sensor kinase is necessary but not sufficient for pilA autoregulation. Furthermore, PilS's phosphatase motif was required for the autoregulation of pilA transcription, suggesting that under conditions where PilA is abundant, the PilA-PilS interaction promotes PilR dephosphorylation and thus down-regulation of further pilA transcription. These data reveal a clever bacterial inventory control strategy in which the major subunit of an important P. aeruginosa virulence factor controls its own expression.

Synthesis, Characterization and Antimicrobial Activity of Zirconium (IV) Complexes

Energy Technology Data Exchange (ETDEWEB)

Sharma, Shobhana; Jain, Asha; Saxena, Sanjiv [Univ. of Rajasthan, Jaipur (India)

2012-08-15

Heteroleptic complexes of zirconium (IV) derived from bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic β-diketones of the general formula ZrLL' (where L'H{sub 2}=RCNH(C{sub 6}H{sub 4})SC : C(OH)N(C{sub 6}H{sub 5})N : CCH{sub 3}, R=-C{sub 6}H{sub 5}, -C{sub 6}H{sub 4}Cl(p) and L'H{sub 2}=R'C : (NOH)C : C(OH)N(C{sub 6}H{sub 5})N : CCH{sub 3}, R' = -CH{sub 2}CH{sub 3}, -C{sub 6}H{sub 5}, -C{sub 6}H{sub 4}Cl (p) were prepared by the reactions of zirconium tetrachloride with disodium salts of Schiff bases (L Na{sub 2}) and oximes of heterocyclic β-diketones (L' Na{sub 2}) in 1:1:1 molar ratio in dry refluxing THF. The structures of these monomeric zirconium (IV) complexes were elucidated with the help of elemental analysis, molecular weight measurements, spectroscopic (IR, NMR and mass) studies. A distorted trigonal bipyramidal geometry may be suggested for these heteroleptic zirconium (IV) complexes. The ligands (bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic β-diketones) and their heteroleptic complexes of zirconium (IV) were screened against A. flavus, P. aeruginesa and E. coli.

Serine-Rich Repeat Proteins and Pili Promote Streptococcus agalactiae Colonization of the Vaginal Tract ▿

Science.gov (United States)

Sheen, Tamsin R.; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M.; Doran, Kelly S.

2011-01-01

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment. PMID:21984789

Adhesive Pili in UTI Pathogenesis and Drug Development.

Science.gov (United States)

Spaulding, Caitlin N; Hultgren, Scott J

2016-03-15

Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting 150 million people each year worldwide. High recurrence rates and increasing antimicrobial resistance among uropathogens are making it imperative to develop alternative strategies for the treatment and prevention of this common infection. In this Review, we discuss how understanding the: (i) molecular and biophysical basis of host-pathogen interactions; (ii) consequences of the molecular cross-talk at the host pathogen interface in terms of disease progression; and (iii) pathophysiology of UTIs is leading to efforts to translate this knowledge into novel therapeutics to treat and prevent these infections.

General report of Technical Committee IV

International Nuclear Information System (INIS)

Feinendegen, L.E.

1979-01-01

During the report period, work in section IV of the Committee was continued on the molecular, cellular and organic levels with the aim to elucidate the origin, course and treatment possibility of the syndrome that may occur in the mammalian organism upon acute and chronic ionizing irradiation as a function of the radiation dose received. The investigations dealt a.o. with the effect of O 2 in protein radiolysis, recovery processes of the haematopoietic stem cells, delayed effects in the gastrointestical tract subsequent to local irradiation, and combination damage in the lungs and liver of rats upon combined cytostatic and radiation therapy. (orig./HP) [de

Astrofísica molecular e infrarroja

OpenAIRE

Cernicharo, José

2007-01-01

Presentado en el IV Curso de Iniciación a la Investigación en Estructura de la Materia: Desde las partículas subatómicas hasta los compuestos moleculares (Instituto de Estructura de la Materia, CSIC, 28-30 de Marzo de 2007). Incluye una presentación del Departamento de Astrofísica Molecular e Infrarroja del IEM.

Oxochloroalkoxide of the Cerium (IV and Titanium (IV as oxides precursor

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Machado Luiz Carlos

2002-01-01

Full Text Available The Cerium (IV and Titanium (IV oxides mixture (CeO2-3TiO2 was prepared by thermal treatment of the oxochloroisopropoxide of Cerium (IV and Titanium (IV. The chemical route utilizing the Cerium (III chloride alcoholic complex and Titanium (IV isopropoxide is presented. The compound Ce5Ti15Cl16O30 (iOPr4(OH-Et15 was characterized by elemental analysis, FTIR and TG/DTG. The X-ray diffraction patterns of the oxides resulting from the thermal decomposition of the precursor at 1000 degreesC for 36 h indicated the formation of cubic cerianite (a = 5.417Å and tetragonal rutile (a = 4.592Å and (c = 2.962 Å, with apparent crystallite sizes around 38 and 55nm, respectively.

Cloning, expression, purification, crystallization and X-ray crystallographic analysis of CofB, the minor pilin subunit of CFA/III from human enterotoxigenic Escherichia coli.

Science.gov (United States)

Kawahara, Kazuki; Oki, Hiroya; Fukakusa, Shunsuke; Maruno, Takahiro; Kobayashi, Yuji; Motooka, Daisuke; Taniguchi, Tooru; Honda, Takeshi; Iida, Tetsuya; Nakamura, Shota; Ohkubo, Tadayasu

2015-06-01

Colonization factor antigen III (CFA/III) is one of the virulence factors of human enterotoxigenic Escherichia coli (ETEC) that forms the long, thin, proteinaceous fibres of type IV pili through assembly of its major and minor subunits CofA and CofB, respectively. The crystal structure of CofA has recently been reported; however, the lack of structural information for CofB, the largest among the known type IV pilin subunits, hampers a comprehensive understanding of CFA/III pili. In this study, constructs of wild-type CofB with an N-terminal truncation and the corresponding SeMet derivative were cloned, expressed, purified and crystallized. The crystals belonged to the rhombohedral space group R32, with unit-cell parameters a = b = 103.97, c = 364.57 Å for the wild-type construct and a = b = 103.47, c = 362.08 Å for the SeMet-derivatized form. Although the diffraction quality of these crystals was initially very poor, dehydration of the crystals substantially improved the resolution limit from ∼ 4.0 to ∼ 2.0 Å. The initial phase was solved by the single-wavelength anomalous dispersion (SAD) method using a dehydrated SeMet CofB crystal, which resulted in an interpretable electron-density map.

Pleiades cluster. IV. The visit of a molecular CO cloud

International Nuclear Information System (INIS)

Breger, M.

1987-01-01

The location, size, and mass of the CO molecular cloud seen in the direction of the Pleiades cluster is determined from a study of the polarization and reddening of cluster members and nonmembers. Arguments are presented against both a foreground and background location of the molecular cloud, so that the cloud should be presently situated inside the cluster. Stellar reddening determinations with the appropriate value of R = 3.3 for the region, as well as star counts, lead to a determination of a total extinction of A(V) in the range of 1.0-1.6 mag for the central region of the CO cloud. The extinction determinations for cluster members and background stars indicate a mass of 20 solar masses for the CO cloud visiting the Pleiades cluster. 20 references

Caratterizzazione di isolati di Pseudomonas aeruginosa provenienti da pazienti affetti da fibrosi cistica

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Giovanna Pulcrano

2007-06-01

Full Text Available Pseudomonas aeruginosa is the major pulmonary pathogen that causes morbidity and mortality in burned, immunocompromised and cystic fibrosis patients. Among the various virulence factors, type IV-pili, play a major role in mediating bacteria-host cells interactions, in formation of biofilm and for twiching motility.These pili are composed of pilin, 15000-16000 molecular weight monomeric subunit, synthesized from pilA gene. The N-terminal region of pilin protein is strong conserved and is important for the oligomerization.The C-terminal region is less conserved and contains a disulfide-bonded loop (DSL structure that is thought to interact with the eukaryotic glycolipid receptor “asialo GM1”. Analysis of pilin allele distribution among isolates from various sources revealed the presence of six groups of pilin allels characterized by different DSL sequence and different associated accessory genes in pilA chromosomal locus. 81 P. aeruginosa isolates were recovered from cystic fibrosis patients during a 3 years period. 30 of these strains were grown and their genomic DNA was prepared using a rapid method for gram-negative bacteria. PCR primers were used for amplification of pilA and adjacent sequences revealing the presence of three different amplification products. One of these is highly homologous with pilA gene of PA14 strain, the others are identical to PA103 and PAK pilA genes. Our study revealed in the prevalence of isolates with group II pilin genes from Cystic Fibrosis compared with other groups that are predominant in previous studies.

Compilação de dados atômicos e moleculares do UV ao IV próximo para uso em síntese espectral

Science.gov (United States)

Coelho, P.; Barbuy, B.; Melendez, J.; Allen, D. M.; Castilho, B.

2003-08-01

Espectros sintéticos são utéis em uma grande variedade de aplicações, desde análise de abundâncias em espectros estelares de alta resolução ao estudo de populações estelares em espectros integrados. A confiabilidade de um espectro sintético depende do modelo de atmosfera adotado, do código de formação de linhas e da qualidade dos dados atômicos e moleculares que são determinantes no cálculo das opacidades da fotosfera. O nosso grupo no departamento de Astronomia no IAG tem utilizado espectros sintéticos há mais de 15 anos, em aplicações voltadas principalmente para a análise de abundâncias de estrelas G, K e M e populações estelares velhas. Ao longo desse tempo, as listas de linhas vieram sendo construídas e atualizadas continuamente, e alguns acréscimos recentes podem ser citados: Castilho (1999, átomos e moléculas no UV), Schiavon (1998, bandas moleculares de TiO) e Melendez (2001, átomos e moléculas no IV próximo). Com o intuito de calcular uma grade de espectros do UV ao IV próximo para uso no estudo de populações estelares velhas, se fazia necessário compilar e homogeneizar as diversas listas em apenas uma lista atômica e uma molecular. Nesse processo, a nova lista compilada foi correlacionada com outras bases de dados (NIST, Kurucz Database, O' Brian et al. 1991) para atualização dos parâmetros que caracterizam a transição atômica (comprimento de onda, log gf e potencial de excitação). Adicionalmente as constantes de interação C6 foram calculadas segundo a teoria de Anstee & O'Mara (1995) e artigos posteriores. As bandas moleculares de CH e CN foram recalculadas com o programa LIFBASE (Luque & Crosley 1999). Nesse poster estão detalhados os procedimentos citados acima, as comparações entre espectros calculados com as novas listas e espectros observados em alta resolução do Sol e de Arcturus, e uma análise do impacto decorrente da utilização de diferentes modelos de atmosfera no espectro sintético. Ao

Preparation and properties of a monomeric Mn(IV)-oxo complex.

Science.gov (United States)

Parsell, Trenton H; Behan, Rachel K; Green, Michael T; Hendrich, Michael P; Borovik, A S

2006-07-12

Manganese-oxo complexes have long been investigated because of their proposed roles in biological and chemical catalysis. However, there are few examples of monomeric complexes with terminal oxo ligands, especially those with oxomanganese(IV) units. A oxomanganese(IV) complex has been prepared from [MnIIIH3buea(O)]2- ([H3buea]3-, tris[(N'-tert-butylureaylato)-N-ethylene]aminato), a monomeric MnIII-O complex in which the oxo ligand arises from cleavage of dioxygen. Treating [MnIIIH3buea(O)]2- with [Cp2Fe]BF4 in either DMF at -45 degrees C or DMSO at room temperature produces [MnIVH3buea(O)]-: lambdamax = 635 nm; nu(Mn-16O) = 737 cm-1; nu(Mn-18O) = 709 cm-1; g = 5.15, 2.44, 1.63, D = 3.0 cm-1, E/D = 0.26, aMn = 66 G (A = 190 MHz). These spectroscopic properties support the assignment of a mononuclear MnIV-oxo complex with an S = 3/2 ground state. Density functional theory supports this assignment and the Jahn-Teller distortion around the high-spin MnIV center that would alter the molecular structure of [MnIVH3buea(O)]- from trigonal symmetry (as indicated by the highly rhombic EPR signal). [MnIVH3buea(O)]- is relatively unstable in DMSO, converting to [MnIIIH3buea(OH)]- via a proposed X-H bond cleavage. [MnIVH3buea(O)]- reacts with 1,2-diphenylhydrazine to from azobenzene (95% yield) and [MnIIIH3buea(OH)]-. The MnIV-oxo does not react with triphenyl- or tricyclohexylphosphine. However, O-atom transfer is observed with methyldiphenylphosphine and dimethylphenylphosphine, producing the corresponding phosphine oxides. These results illustrate the diverse reactivity of the MnIV-oxo unit.

Magnetic-superexchange interactions of uranium(IV) chloride-addition complexes with amides, 2

International Nuclear Information System (INIS)

Miyake, Chie; Hinatsu, Yukio; Imoto, Shosuke

1983-01-01

The magnetic susceptibilities of five cyclic amide (lactam)-addition complexes of uranium(IV) chloride were measured between room temperature and 2 K. Magnetic-exchange interaction was found only for N-methyl-substituted amide complexes, and a dimer structure was assumed for them on the basis of their chemical properties. Treating interdimer interaction with a molecular-field approximation, the magnetic susceptibilities were calculated to be in good agreement with the experimental results in the temperature region of the maxima in chi sub(A). The transmission of antiparallel spin coupling via the π orbitals of the bridging amide ligands is proposed to explain the strong intradimer superexchange interaction for the uranium(IV) chloride-amide complexes with the magnetic-susceptibility maximum. (author)

Comparison of the toxicity of the dyes Sudan II and Sudan IV to catalase.

Science.gov (United States)

Li, Tong; Hao, Minglu; Pan, Jie; Zong, Wansong; Liu, Rutao

2017-10-01

The mechanisms of the toxicity of Sudan dyes to the key antioxidant enzyme catalase (CAT) were investigated by spectroscopic methods, calorimetry techniques, enzyme activity assay, and molecular docking. Results showed that Sudan dyes bound to CAT through hydrophobic force, which changed the microenvironment of tryptophan and tyrosine residues, leading to a conformational alteration and shrinkage of the protein. Enzyme activity assay and molecular docking revealed that the activity of CAT was slightly inhibited in the presence of Sudan dyes. In comparison, the binding of Sudan II with CAT was slightly stronger than Sudan IV. Also, Sudan II and Sudan IV showed a different impact on the microenvironment of aromatic amino acid residues. But the dyes had very similar effects on conformation and activity of the protein. This work provides an essential reference for the evaluation of Sudan dyes' effects on body's antioxidant defense system and safe use of Sudan dyes. © 2017 Wiley Periodicals, Inc.

Transuranium perrhenates: Np(IV), Pu(IV) and (III), Am (III)

International Nuclear Information System (INIS)

Silvestre, Jean-Paul; Freundlich, William; Pages, Monique

1977-01-01

Synthesis in aqueous solution and by solid state reactions, crystallographical characterization and study of the stability of some transuranium perrhenates: Asup(n+)(ReO 4 - )sub(n) (A=Np(IV), Pu(IV), Pu(III), Am(III) [fr

Effect of pH and uranium concentration on interaction of uranium(VI) and uranium(IV) with organic ligands in aqueous solutions

International Nuclear Information System (INIS)

Li, W.C.; Victor, D.M.; Chakrabarti, C.L.

1980-01-01

The effect of pH and uranium concentration on the interactions of uranium(VI) and uranium(IV) with organic ligands was studied by employing dialysis and ultrafiltration techniques. The interactions of U(VI) and U(IV) with organic ligands in nitrate or chloride aqueous solution have been found to be pH-dependent. The stability constants of uranium-organic complexes decrease in the order: fulvic acid>humic acid>tannic acid for U(VI) and humic acid>tannic acid>fulvic acid for U(IV). Scatchard plots for the uranium-organic acid systems indicate two types of binding sites with a difference in stability constants of about 10 2 . Ultrafiltration of uranium-humic acid complexes indicates that U(VI) and U(IV) ions are concentrated in larger molecular size fractions (>5.1 nm) at pH less than or equal to 3 and in smaller molecular size fractions (in the range 5.1 to 3.1 nm and 2.4 to 1.9 nm) at pH greater than or equal to 5. 7 figures, 4 tables

Investigation on the formation of a third phase in the extraction of Pu(IV) nitrate with tributyl phosphate

International Nuclear Information System (INIS)

Yu Enjiang; Liu Liming; Huang Huaian

1986-01-01

The formation of a third phase is studied in the system Pu(IV) nitratenitric acid-TBP-alkane diluent (or kerosine). The maximum concentration (solubility, S Pu ) of Pu(IV) in the equilibrium organic phase at which still no third phase is formed is measured as a function of the nitric acid concentration in the equilibrium aqueous phase C H , the temperature, and the molecular size of n-alkane duluent. Results show that maxima of S Pu at 6 to 7 M nitric acid are observed at 17 deg C, 26 deg C and 35 deg C while not at 40 deg C. Minima on the S Pu vs. C H curves at 0.5 to 2 M mitric acid have been observed at 17 deg C and 26 deg C. It is found that the molecular size of n-alkane diluents has a very pronounced effect on S Pu . The effect of aqueous equilibrium Pu(IV) concentration on the formation of a third phase is investigated, when the equilibrium HNO 3 concentration is 3.5 M. It is shown that the plutonium concentration of the third phase is increased with increasing aqueous equilibrium Pu(IV) concentration. The effect of the addition of lauryl alcohol on the S Pu is preliminarily studied

The First Homoleptic Complex of Seven-Coordinated Osmium: Synthesis and Crystallographical Evidence of Pentagonal Bipyramidal Polyhedron of Heptacyanoosmate(IV

Directory of Open Access Journals (Sweden)

Eugenia V. Peresypkina

2016-08-01

Full Text Available The ligand exchange in (n-Bu4N2OsIVCl6 (n-Bu4N = tetra-n-butylammonium leads to the formation of the osmium(IV heptacyanide, the first fully inorganic homoleptic complex of heptacoordinated osmium. The single-crystal X-ray diffraction (SC-XRD study reveals the pentagonal bipyramidal molecular structure of the [Os(CN7]3− anion. The latter being a diamagnetic analogue of the highly anisotropic paramagnetic synthon, [ReIV(CN7]3− can be used for the synthesis of the model heterometallic coordination compounds for the detailed study and simulation of the magnetic properties of the low-dimensional molecular nanomagnets involving 5d metal heptacyanides.

Coordination and solvent extraction behaviour of oxozirconium(IV), thorium(IV) and dioxouranium(VI)

International Nuclear Information System (INIS)

Dash, K.C.

1989-01-01

The systematic liquid-liquid extraction behaviour of oxozirconium (IV), thorium(IV) and dioxouranium(VI) have been investigated using a number of synthesised and commercial chelating extractants. The synergism or antagonism for these processes in presence of neutral donor ligands have also been identified and the conditions for separation and isolation of pure individual metal ions have been established. The coordination behaviour of oxozirconium(IV), thorium(IV) and dioxouranium(VI) with a large number of mono- and polydentate ligands have been studied. With oxozirconium(IV), invariably always a cyclic, tetranuclear species is obtained, derived from the tetrameric structure of the parent ZrOCl 2 .8H 2 O which is actually (Zr 4 (OH) 8 (H 2 O) 16 )Cl 8 .12H 2 O. No simple, monomeric oxozirconium(IV) complex was obtained. Uranium(VI) and thorium(IV) form a wide variety of complexes of higher coordination numbers and several bi- and trinuclear complexes were also characterised where the two adjacent metal centres are joined to each other by a double hydroxo-bridge. (author). 69 refs., 3 figs., 4 tabs

Structural studies on Langmuir-Blodgett ultra-thin films on tin (IV) stearate using X-ray diffraction technique

International Nuclear Information System (INIS)

Mohamad Deraman; Muhamad Mat Salleh; Mohd Ali Sulaiman; Mohd Ali Sufi

1991-01-01

X-ray diffraction measurements were carried out on Langmuir-Blodgett (LB) ultra-thin films of tin (IV) stearate for different numbers of layers. The structural information such as interplanar spacing, unit cells spacing, molecular length and orientation of molecular chains were obtained from the diffraction data. This information is discussed and compared with that previously published for LB ultra-thin films of manganese stearate and cadmium stearate

Impeding 99Tc(IV) mobility in novel waste forms

Science.gov (United States)

Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

2016-01-01

Technetium (99Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures. PMID:27357121

(N-Benzyl-N-isopropyl­dithio­carbamato)chloridodiphenyl­tin(IV)

Science.gov (United States)

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Ng, Seik Weng; Tiekink, Edward R. T.

2010-01-01

The SnIV atom in the title organotin dithio­carbamate, [Sn(C6H5)2(C11H14NS2)Cl], is penta-coordinated by an asymmetrically coordinating dithio­carbamate ligand, a Cl and two ispo-C atoms of the Sn-bound phenyl groups. The resulting C2ClS2 donor set defines a coordination geometry inter­mediate between square-pyramidal and trigonal-bipyramidal with a slight tendency towards the latter. The formation of close intra­molecular C–H⋯Cl and C–H⋯S contacts precludes the Cl and S atoms from forming significant inter­molecular contacts. The presence of C–H⋯π contacts leads to the formation of supra­molecular arrays that stack along the b axis. PMID:21588504

Synthesis and characterization of chiral thorium(IV) and uranium(IV) benzamidinate complexes

Energy Technology Data Exchange (ETDEWEB)

Schoene, Sebastian; Maerz, Juliane; Kaden, Peter; Patzschke, Michael; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements

2017-06-01

Two chiral benzamidinate complexes of tetravalent actinides (Th(IV) and U(IV)) were synthesized using a salt metathesis reaction of the corresponding actinide(IV) tetrachlorides and the potassium salt of the chiral benzamidine (S,S)-N,N-Bis-(1-phenylethyl)-benzamidine ((S)-HPEBA). The structure of the complexes was determined with single crystal X-ray diffraction. These are the first examples of chiral amidinate complexes of actinides.

Päiväkoti Riemula

OpenAIRE

Alanko, Reetta; Ihanamäki, Katja

2012-01-01

Opinnäytetyössä kuvataan yleisesti päivähoidon kehitystä Suomessa sekä päivähoitoa yrittäjän näkökulmasta, tuoden esille sen tämän päivän haasteet ja mahdollisuudet. Työssä on pohdittu yhteistyön merkitystä kunnan kanssa ja sitä, miten kunta voi osaltaan joko rajoittaa tai edesauttaa yksityisen päivähoitoyrityksen toimintaa. Opinnäytetyössä kerrotaan teoriassa Päiväkoti Riemula nimisen, erityispäivähoitopalveluita tarjoavan yrityksen perustamiseen liittyvistä suunnitelmista. Suunnitelluss...

Synthesis of diorganoplatinum(IV) complexes by the Ssbnd S bond cleavage with platinum(II) complexes

Science.gov (United States)

Niroomand Hosseini, Fatemeh; Rashidi, Mehdi; Nabavizadeh, S. Masoud

2016-12-01

Reaction of [PtR2(NN)] (R = Me, p-MeC6H4 or p-MeOC6H4; NN = 2,2‧-bipyridine, 4,4‧-dimethyl-2,2‧-bipyridine, 1,10-phenanthroline or 2,9-dimethyl-1,10-phenanthroline) with MeSSMe gives the platinum(IV) complexes cis,trans-[PtR2(SMe)2(NN)]. They are characterized by NMR spectroscopy and elemental analysis. The geometries and the nature of the frontier molecular orbitals of Pt(IV) complexes containing Ptsbnd S bonds are studied by means of the density functional theory.

Octacyanoniobate(IV)-based molecular magnets revealing 3D long-range order

International Nuclear Information System (INIS)

Pelka, R; Balanda, M; Pinkowicz, D; Drath, O; Nitek, W; Sieklucka, B; Rams, M; Majcher, A

2011-01-01

Isostructural series of chemical formula {[M II (pirazol) 4 ] 2 [Nb IV (CN) 8 ]· 4H 2 O} n (M II = Mn (1), Fe (2), Co (3), Ni (4)) has been obtained by the self-assembly technique. Its unique crystallographic structure consists in the formation of a 3D extended network of magnetic centers braced by geometrically identical cyanido bridges. Magnetic measurements reveal the transitions to the 3D order at temperatures 23.7, 8.3, 5.9, 13.4 K for 1, 2, 3, and 4, respectively. The character of order is demonstrated to be ferrimagnetic for 1 and 2 and ferromagnetic for 3 and 4. The mean-field approach is used to determine the corresponding exchange coupling constants. The observed interactions are discussed within the magnetic orbital model.

Octacyanoniobate(IV)-based molecular magnets revealing 3D long-range order

Science.gov (United States)

Pełka, R.; Pinkowicz, D.; Drath, O.; Bałanda, M.; Rams, M.; Majcher, A.; Nitek, W.; Sieklucka, B.

2011-07-01

Isostructural series of chemical formula {[MII(pirazol)4]2[NbIV(CN)8]· 4H2O}n (MII = Mn (1), Fe (2), Co (3), Ni (4)) has been obtained by the self-assembly technique. Its unique crystallographic structure consists in the formation of a 3D extended network of magnetic centers braced by geometrically identical cyanido bridges. Magnetic measurements reveal the transitions to the 3D order at temperatures 23.7, 8.3, 5.9, 13.4 K for 1, 2, 3, and 4, respectively. The character of order is demonstrated to be ferrimagnetic for 1 and 2 and ferromagnetic for 3 and 4. The mean-field approach is used to determine the corresponding exchange coupling constants. The observed interactions are discussed within the magnetic orbital model.

IV access in dental practice.

LENUS (Irish Health Repository)

Fitzpatrick, J J

2009-04-01

Intravenous (IV) access is a valuable skill for dental practitioners in emergency situations and in IV sedation. However, many people feel some apprehension about performing this procedure. This article explains the basic principles behind IV access, and the relevant anatomy and physiology, as well as giving a step-by-step guide to placing an IV cannula.

Large-Area, Ensemble Molecular Electronics: Motivation and Challenges.

Science.gov (United States)

Vilan, Ayelet; Aswal, Dinesh; Cahen, David

2017-03-08

We review charge transport across molecular monolayers, which is central to molecular electronics (MolEl), using large-area junctions (NmJ). We strive to provide a wide conceptual overview of three main subtopics. First, a broad introduction places NmJ in perspective to related fields of research and to single-molecule junctions (1mJ) in addition to a brief historical account. As charge transport presents an ultrasensitive probe for the electronic perfection of interfaces, in the second part ways to form both the monolayer and the contacts are described to construct reliable, defect-free interfaces. The last part is dedicated to understanding and analyses of current-voltage (I-V) traces across molecular junctions. Notwithstanding the original motivation of MolEl, I-V traces are often not very sensitive to molecular details and then provide a poor probe for chemical information. Instead, we focus on how to analyze the net electrical performance of molecular junctions, from a functional device perspective. Finally, we point to creation of a built-in electric field as a key to achieve functionality, including nonlinear current-voltage characteristics that originate in the molecules or their contacts to the electrodes. This review is complemented by a another review that covers metal-molecule-semiconductor junctions and their unique hybrid effects.

Native pyroglutamation of huwentoxin-IV: a post-translational modification that increases the trapping ability to the sodium channel.

Science.gov (United States)

Rong, Mingqiang; Duan, Zhigui; Chen, Juliang; Li, Jianglin; Xiao, Yuchen; Liang, Songping

2013-01-01

Huwentoxin-IV (HWTX-IV), a tetrodotoxin-sensitive (TTX-s) sodium channel antagonist, is found in the venom of the Chinese spider Ornithoctonus huwena. A naturally modified HWTX-IV (mHWTX-IV), having a molecular mass 18 Da lower than HWTX-IV, has also been isolated from the venom of the same spider. By a combination of enzymatic fragmentation and MS/MS de novo sequencing, mHWTX-IV has been shown to have the same amino acid sequence as that of HWTX-IV, except that the N-terminal glutamic acid replaced by pyroglutamic acid. mHWTX-IV inhibited tetrodotoxin-sensitive voltage-gated sodium channels of dorsal root ganglion neurons with an IC50 nearly equal to native HWTX-IV. mHWTX-IV showed the same activation and inactivation kinetics seen for native HWTX-IV. In contrast with HWTX-IV, which dissociates at moderate voltage depolarization voltages (+50 mV, 180000 ms), mHWTX-IV inhibition of TTX-sensitive sodium channels is not reversed by strong depolarization voltages (+200 mV, 500 ms). Recovery of Nav1.7current was voltage-dependent and was induced by extreme depolarization in the presence of HWTX-IV, but no obvious current was elicited after application of mHWTX-IV. Our data indicate that the N-terminal modification of HWTX-IV gives the peptide toxin a greater ability to trap the voltage sensor in the sodium channel. Loss of a negative charge, caused by cyclization at the N-terminus, is a possible reason why the modified toxin binds much stronger. To our knowledge, this is the first report of a pyroglutamic acid residue in a spider toxin; this modification seems to increase the trapping ability of the voltage sensor in the sodium channel.

Native pyroglutamation of huwentoxin-IV: a post-translational modification that increases the trapping ability to the sodium channel.

Directory of Open Access Journals (Sweden)

Mingqiang Rong

Full Text Available Huwentoxin-IV (HWTX-IV, a tetrodotoxin-sensitive (TTX-s sodium channel antagonist, is found in the venom of the Chinese spider Ornithoctonus huwena. A naturally modified HWTX-IV (mHWTX-IV, having a molecular mass 18 Da lower than HWTX-IV, has also been isolated from the venom of the same spider. By a combination of enzymatic fragmentation and MS/MS de novo sequencing, mHWTX-IV has been shown to have the same amino acid sequence as that of HWTX-IV, except that the N-terminal glutamic acid replaced by pyroglutamic acid. mHWTX-IV inhibited tetrodotoxin-sensitive voltage-gated sodium channels of dorsal root ganglion neurons with an IC50 nearly equal to native HWTX-IV. mHWTX-IV showed the same activation and inactivation kinetics seen for native HWTX-IV. In contrast with HWTX-IV, which dissociates at moderate voltage depolarization voltages (+50 mV, 180000 ms, mHWTX-IV inhibition of TTX-sensitive sodium channels is not reversed by strong depolarization voltages (+200 mV, 500 ms. Recovery of Nav1.7current was voltage-dependent and was induced by extreme depolarization in the presence of HWTX-IV, but no obvious current was elicited after application of mHWTX-IV. Our data indicate that the N-terminal modification of HWTX-IV gives the peptide toxin a greater ability to trap the voltage sensor in the sodium channel. Loss of a negative charge, caused by cyclization at the N-terminus, is a possible reason why the modified toxin binds much stronger. To our knowledge, this is the first report of a pyroglutamic acid residue in a spider toxin; this modification seems to increase the trapping ability of the voltage sensor in the sodium channel.

Molecular Imaging in Schizophrenia Spectrum Disorders

NARCIS (Netherlands)

Klein, H.C.; Doorduin, J.; van Berckel, B.N.M.

2014-01-01

In this chapter, we aim to shed light on the schizophrenia spectrum disorders using molecular imaging. Schizophrenia spectrum disorders consist primarily of the disorders with full-blown psychosis in their course and are grouped in the DSM-IV category of schizophrenia and other psychotic disorders.

Complexation of the An(IV) by NTA; Complexation des An(IV) par le NTA

Energy Technology Data Exchange (ETDEWEB)

Bonin, L. [Paris-11 Univ., 91 - Orsay (France)]|[CEA Valrho, Lab. de Chimie des Actinides (LCA), 30 - Marcoule (France)

2006-07-01

In the framework of the Nuclear and Environmental Toxicology program, developed in France, it has been decided to take again the studies concerning the actinides decorporation. A similar study of the neptunium complexation by the citrate ions has been carried out on the complexation of Np(IV) with the nitrilotriacetic acid (NTA). The NTA can be considered as a model molecule of the de-corporating molecules (amino-carboxy- ligand). The results of the spectrophotometric measurements being encouraging, the behaviour of several actinides at the same oxidation state (+IV) (Th(IV), U(IV), Np(IV), and Pu(IV)) has been determined. The experimental results are presented. In order to determine the structure of the complexes of stoichiometry 1:2 An(IV)-(NTA){sub 2} in solution, quantic chemistry calculations and EXAFS measurements have been carried out in parallel. These studies confirm the presence of An(IV)-nitrogen bonds whose length decreases from thorium to plutonium and indicate the presence of a water molecule bound to the thorium and the uranium (coordination number 8 for Np/Pu, 9 for Th/U). The evolution of the complexation constants determined in this study in terms of 1/r (r ionic radius of the cation taking into account its coordination number 8 or 9) confirms the change of the coordination number between Th/U and Np/Pu. (O.M.)

The c.IVS1+1G>A mutation inthe GJB2 gene is prevalent and large ...

Indian Academy of Sciences (India)

IVS1+1G>A mutation inthe GJB2 gene is prevalent and large deletions involving the GJB6 gene are not present in the Turkish population. ASLI SIRMACI, DUYGU AKCAYOZ-DUMAN and MUSTAFA TEKIN∗. Division of Pediatric Molecular Genetics, Ankara University School of Medicine, Ankara 06100, Turkey. Introduction.

Octacyanoniobate(IV)-based molecular magnets revealing 3D long-range order

Energy Technology Data Exchange (ETDEWEB)

Pelka, R; Balanda, M [Institute of Physics PAN, Radzikowskiego 152, 31-342, Krakow (Poland); Pinkowicz, D; Drath, O; Nitek, W; Sieklucka, B [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Rams, M; Majcher, A, E-mail: robert.pelka@ifj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

2011-07-06

Isostructural series of chemical formula {l_brace}[M{sup II}(pirazol){sub 4}]{sub 2}[Nb{sup IV}(CN){sub 8}]{center_dot} 4H{sub 2}O{r_brace}{sub n} (M{sup II} = Mn (1), Fe (2), Co (3), Ni (4)) has been obtained by the self-assembly technique. Its unique crystallographic structure consists in the formation of a 3D extended network of magnetic centers braced by geometrically identical cyanido bridges. Magnetic measurements reveal the transitions to the 3D order at temperatures 23.7, 8.3, 5.9, 13.4 K for 1, 2, 3, and 4, respectively. The character of order is demonstrated to be ferrimagnetic for 1 and 2 and ferromagnetic for 3 and 4. The mean-field approach is used to determine the corresponding exchange coupling constants. The observed interactions are discussed within the magnetic orbital model.

LARGE-SCALE CO MAPS OF THE LUPUS MOLECULAR CLOUD COMPLEX

International Nuclear Information System (INIS)

Tothill, N. F. H.; Loehr, A.; Stark, A. A.; Lane, A. P.; Harnett, J. I.; Bourke, T. L.; Myers, P. C.; Parshley, S. C.; Wright, G. A.; Walker, C. K.

2009-01-01

Fully sampled degree-scale maps of the 13 CO 2-1 and CO 4-3 transitions toward three members of the Lupus Molecular Cloud Complex-Lupus I, III, and IV-trace the column density and temperature of the molecular gas. Comparison with IR extinction maps from the c2d project requires most of the gas to have a temperature of 8-10 K. Estimates of the cloud mass from 13 CO emission are roughly consistent with most previous estimates, while the line widths are higher, around 2 km s -1 . CO 4-3 emission is found throughout Lupus I, indicating widespread dense gas, and toward Lupus III and IV. Enhanced line widths at the NW end and along the edge of the B 228 ridge in Lupus I, and a coherent velocity gradient across the ridge, are consistent with interaction between the molecular cloud and an expanding H I shell from the Upper-Scorpius subgroup of the Sco-Cen OB Association. Lupus III is dominated by the effects of two HAe/Be stars, and shows no sign of external influence. Slightly warmer gas around the core of Lupus IV and a low line width suggest heating by the Upper-Centaurus-Lupus subgroup of Sco-Cen, without the effects of an H I shell.

Preparation of graphene oxide-manganese dioxide for highly efficient adsorption and separation of Th(IV)/U(VI).

Science.gov (United States)

Pan, Ning; Li, Long; Ding, Jie; Li, Shengke; Wang, Ruibing; Jin, Yongdong; Wang, Xiangke; Xia, Chuanqin

2016-05-15

Manganese dioxide decorated graphene oxide (GOM) was prepared via fixation of crystallographic MnO2 (α, γ) on the surface of graphene oxide (GO) and was explored as an adsorbent material for simultaneous removal of thorium/uranium ions from aqueous solutions. In single component systems (Th(IV) or U(VI)), the α-GOM2 (the weight ratio of GO/α-MnO2 of 2) exhibited higher maximum adsorption capacities toward both Th(IV) (497.5mg/g) and U(VI) (185.2 mg/g) than those of GO. In the binary component system (Th(IV)/U(VI)), the saturated adsorption capacity of Th(IV) (408.8 mg/g)/U(VI) (66.8 mg/g) on α-GOM2 was also higher than those on GO. Based on the analysis of various data, it was proposed that the adsorption process may involve four types of molecular interactions including coordination, electrostatic interaction, cation-pi interaction, and Lewis acid-base interaction between Th(IV)/U(VI) and α-GOM2. Finally, the Th(IV)/U(VI) ions on α-GOM2 can be separated by a two-stage desorption process with Na2CO3/EDTA. Those results displayed that the α-GOM2 may be utilized as an potential adsorbent for removing and separating Th(IV)/U(VI) ions from aqueous solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

Genetic diversity of internalin genes in the ascB-dapE locus among Listeria monocytogenes lineages III and IV strains.

Science.gov (United States)

Chen, Jianshun; Cheng, Changyong; Lv, Yonghui; Fang, Weihuan

2013-09-01

Listeria monocytogenes is an important foodborne pathogen encompassing four phylogenetic lineages. Lineages III and IV are rare, but have been reported to show considerable biodiversity, providing important clues for the evolutionary history in Listeria. In this study, analysis of the ascB-dapE locus reveals genetic diversity in lineages III and IV, and is consistent with the classification of sublineages. Four of the six genetic patterns (two of sublineage IIIC and two of lineage IV) are specific to these two lineages. The ascB-dapE locus suggests a hot spot for genome diversification, and serves as an attractive molecular marker for better understanding of the biodiversity and population structure of lineages III and IV strains. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comprehensive mutagenesis of the fimS promoter regulatory switch reveals novel regulation of type 1 pili in uropathogenic Escherichia coli.

Science.gov (United States)

Zhang, Huibin; Susanto, Teodorus T; Wan, Yue; Chen, Swaine L

2016-04-12

Type 1 pili (T1P) are major virulence factors for uropathogenic Escherichia coli (UPEC), which cause both acute and recurrent urinary tract infections. T1P expression therefore is of direct relevance for disease. T1P are phase variable (both piliated and nonpiliated bacteria exist in a clonal population) and are controlled by an invertible DNA switch (fimS), which contains the promoter for the fim operon encoding T1P. Inversion of fimS is stochastic but may be biased by environmental conditions and other signals that ultimately converge at fimS itself. Previous studies of fimS sequences important for T1P phase variation have focused on laboratory-adapted E coli strains and have been limited in the number of mutations or by alteration of the fimS genomic context. We surmounted these limitations by using saturating genomic mutagenesis of fimS coupled with accurate sequencing to detect both mutations and phase status simultaneously. In addition to the sequences known to be important for biasing fimS inversion, our method also identifies a previously unknown pair of 5' UTR inverted repeats that act by altering the relative fimA levels to control phase variation. Thus we have uncovered an additional layer of T1P regulation potentially impacting virulence and the coordinate expression of multiple pilus systems.

More than a Tad: spatiotemporal control of Caulobacter pili.

Science.gov (United States)

Mignolet, Johann; Panis, Gaël; Viollier, Patrick H

2018-04-01

The Type IV pilus (T4P) is a powerful and sophisticated bacterial nanomachine involved in numerous cellular processes, including adhesion, DNA uptake and motility. Aside from the well-described subtype T4aP of the Gram-negative genera, including Myxococcus, Pseudomonas and Neisseria, the Tad (tight adherence) pilus secretion system re-shuffles homologous parts from other secretion systems along with uncharacterized components into a new type of protein translocation apparatus. A representative of the Tad apparatus, the Caulobacter crescentus pilus assembly (Cpa) machine is built exclusively at the newborn cell pole once per cell cycle. Recent comprehensive genetic analyses unearthed a myriad of spatiotemporal determinants acting on the Tad/Cpa system, many of which are conserved in other α-proteobacteria, including obligate intracellular pathogens and symbionts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Analysis of Inpatient Costs for Obstetrics and Gynecology Surgery Patients Treated With IV Acetaminophen and IV Opioids Versus IV Opioid-only Analgesia for Postoperative Pain.

Science.gov (United States)

Hansen, Ryan N; Pham, An T; Lovelace, Belinda; Balaban, Stela; Wan, George J

2017-10-01

Recovery from obstetrics and gynecology (OB/GYN) surgery, including hysterectomy and cesarean section delivery, aims to restore function while minimizing hospital length of stay (LOS) and medical expenditures. Our analyses compare OB/GYN surgery patients who received combination intravenous (IV) acetaminophen and IV opioid analgesia with those who received IV opioid-only analgesia and estimate differences in LOS, hospitalization costs, and opioid consumption. We performed a retrospective analysis of the Premier Database between January 2009 and June 2015, comparing OB/GYN surgery patients who received postoperative pain management with combination IV acetaminophen and IV opioids with those who received only IV opioids starting on the day of surgery and continuing up to the second postoperative day. We performed instrumental variable 2-stage least-squares regressions controlling for patient and hospital covariates to compare the LOS, hospitalization costs, and daily opioid doses (morphine equivalent dose) of IV acetaminophen recipients with that of opioid-only analgesia patients. We identified 225 142 OB/GYN surgery patients who were eligible for our study of whom 89 568 (40%) had been managed with IV acetaminophen and opioids. Participants averaged 36 years of age and were predominantly non-Hispanic Caucasians (60%). Multivariable regression models estimated statistically significant differences in hospitalization cost and opioid use with IV acetaminophen associated with $484.4 lower total hospitalization costs (95% CI = -$760.4 to -$208.4; P = 0.0006) and 8.2 mg lower daily opioid use (95% CI = -10.0 to -6.4), whereas the difference in LOS was not significant, at -0.09 days (95% CI = -0.19 to 0.01; P = 0.07). Compared with IV opioid-only analgesia, managing post-OB/GYN surgery pain with the addition of IV acetaminophen is associated with decreased hospitalization costs and reduced opioid use.

X-Band Electron Paramagnetic Resonance Comparison of Mononuclear Mn(IV)-oxo and Mn(IV)-hydroxo Complexes and Quantum Chemical Investigation of Mn(IV) Zero-Field Splitting.

Science.gov (United States)

Leto, Domenick F; Massie, Allyssa A; Colmer, Hannah E; Jackson, Timothy A

2016-04-04

X-band electron paramagnetic resonance (EPR) spectroscopy was used to probe the ground-state electronic structures of mononuclear Mn(IV) complexes [Mn(IV)(OH)2(Me2EBC)](2+) and [Mn(IV)(O)(OH)(Me2EBC)](+). These compounds are known to effect C-H bond oxidation reactions by a hydrogen-atom transfer mechanism. They provide an ideal system for comparing Mn(IV)-hydroxo versus Mn(IV)-oxo motifs, as they differ by only a proton. Simulations of 5 K EPR data, along with analysis of variable-temperature EPR signal intensities, allowed for the estimation of ground-state zero-field splitting (ZFS) and (55)Mn hyperfine parameters for both complexes. From this analysis, it was concluded that the Mn(IV)-oxo complex [Mn(IV)(O)(OH)(Me2EBC)](+) has an axial ZFS parameter D (D = +1.2(0.4) cm(-1)) and rhombicity (E/D = 0.22(1)) perturbed relative to the Mn(IV)-hydroxo analogue [Mn(IV)(OH)2(Me2EBC)](2+) (|D| = 0.75(0.25) cm(-1); E/D = 0.15(2)), although the complexes have similar (55)Mn values (a = 7.7 and 7.5 mT, respectively). The ZFS parameters for [Mn(IV)(OH)2(Me2EBC)](2+) were compared with values obtained previously through variable-temperature, variable-field magnetic circular dichroism (VTVH MCD) experiments. While the VTVH MCD analysis can provide a reasonable estimate of the magnitude of D, the E/D values were poorly defined. Using the ZFS parameters reported for these complexes and five other mononuclear Mn(IV) complexes, we employed coupled-perturbed density functional theory (CP-DFT) and complete active space self-consistent field (CASSCF) calculations with second-order n-electron valence-state perturbation theory (NEVPT2) correction, to compare the ability of these two quantum chemical methods for reproducing experimental ZFS parameters for Mn(IV) centers. The CP-DFT approach was found to provide reasonably acceptable values for D, whereas the CASSCF/NEVPT2 method fared worse, considerably overestimating the magnitude of D in several cases. Both methods were poor in

Enhanced adsorption of active brilliant red X-3B dye on chitosan molecularly imprinted polymer functionalized with Ti(IV) as Lewis acid.

Science.gov (United States)

Deng, Hui; Wei, Zhilai; Wang, XiaoNing

2017-02-10

A Ti(IV) functionalized chitosan molecularly imprinted polymer (Ti-CSMIP) was successfully prepared. Ti 4+ as Lewis acidic was used to modify chitosan MIP by producing metal hydroxyl group and protonated surface of adsorbent in aqueous solution to recognize X-3B molecule as a Lewis base. The adsorbent was characterized by FTIR, SEM, XRD, BET, elemental and zeta potential analysis. XRD illustrated Ti-CSMIP exhibited a weak anatase phase when Ti 4+ cross-linked with chitosan. Batch adsorption experiments were performed to evaluate adsorption condition, including sorption isotherm, kinetics and reusability. The maximum adsorption capacity of Ti-CSMIP for X-3B was 161.1mg/g at 293K when solution pH was in the range of 6.0-7.0. Equilibrium data was well analyzed by three-parameter isotherm model, and the kinetics of adsorption followed the pseudo-second kinetics equation. Regeneration experiments indicated a possible application as an effective sorbent for the selective removal of azo anionic dye in aqueous solutions. Copyright © 2016 Elsevier Ltd. All rights reserved.

IV treatment at home

Science.gov (United States)

... Other IV treatments you may receive after you leave the hospital include: Treatment for hormone deficiencies Medicines for severe nausea that cancer chemotherapy or pregnancy may cause Patient-controlled analgesia (PCA) for pain (this is IV ...

Alterations of type IV collagen alpha chains in patients with chronic acquired glomerulopathies: mRNA levels, protein expression and urinary loss.

Science.gov (United States)

Sanna-Cherchi, Simone; Carnevali, Maria Luisa; Martorana, Davide; Cravedi, Paolo; Maggiore, Umberto; Alinovi, Rossella; Bovino, Achiropita; Mattei, Silvia; Orlandini, Guido; Gatti, Rita; Savi, Mario; Sado, Yoshikazu; Neri, Tauro M; Allegri, Landino

2007-01-01

Type IV collagen is a major structural component of the normal kidney glomerulus. However, its role in chronic acquired glomerulopathies has been only partially elucidated. Urinary levels of col(IV)alpha1, col(IV)alpha3 and col(IV)alpha5 collagen chains were analyzed in 107 patients with chronic acquired glomerulopathies. In a subgroup of 33 patients, tissue mRNA levels, protein expression and urinary excretion were evaluated for all col(IV)alpha chains, from col(IV)alpha1 to col(IV)alpha5. The renal specimens were examined to get a semiquantitative score of the acute and chronic activity of the histological lesions. Urines obtained from 13 healthy subjects and 10 normal renal tissue samples were used as controls. Urinary levels of col(IV)alpha1, col(IV)alpha3, col(IV)alpha5 chains were significantly higher in patients than in controls [p < 0.01 for all], while only col(IV)alpha1 and col(IV)alpha3 urinary excretion correlated with the degree of chronic histological damage [col(IV)alpha1 R = 0.44, p < 0.001; col(IV)alpha3: R = 0.47, p < 0.001]. Compared with controls, patients showed a renal expression of mRNA for col(IV)alpha5 chain significantly higher [p = 0.001], while having a significantly lower protein expression of col(IV)alpha3, col(IV)alpha4 and col(IV)alpha5 chains [p < 0.01 for all]. Patients with chronic acquired glomerulopathies show important alterations in the col(IV)alpha chain network mimicking some molecular features of the X-linked Alport's syndrome. Further studies are needed to show whether urinary levels of the col(IV)alpha chains may be used as markers for monitoring renal injury. Copyright 2007 S. Karger AG, Basel.

Inhibitors of dipeptidyl peptidase IV: a novel approach for the prevention and treatment of Type 2 diabetes?

DEFF Research Database (Denmark)

Deacon, Carolyn F; Ahrén, Bo; Holst, Jens J

2004-01-01

that has warranted the design of inhibitor-based drugs. At the molecular level, DPP IV cleaves two amino acids from the N-terminus of the intact, biologically active forms of both so-called incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide (formerly known......, prevent the progressive impairment of glucose metabolism in patients with impaired glucose tolerance and Type 2 diabetes. DPP IV has become a focus of attention for drug design, as it has a pivotal role in the rapid degradation of at least two of the hormones released during food ingestion, a property...

A cerium(IV)-carbon multiple bond

Energy Technology Data Exchange (ETDEWEB)

Gregson, Matthew; Lu, Erli; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry

2013-12-02

Straightforward access to a cerium(IV)-carbene complex was provided by one-electron oxidation of an anionic ''ate'' cerium(III)-carbene precursor, thereby avoiding decomposition reactions that plague oxidations of neutral cerium(III) compounds. The cerium(IV)-carbene complex is the first lanthanide(IV)-element multiple bond and involves a twofold bonding interaction of two electron pairs between cerium and carbon. [German] Auf direktem Wege zu einem Cer(IV)-Carbenkomplex gelangt man durch die Einelektronenoxidation einer anionischen Carben-Cerat(III)-Vorstufe. So werden Zersetzungsprozesse vermieden, die die Oxidation neutraler Cer(III)-Verbindungen erschweren. Der Cer(IV)-Carbenkomplex enthaelt die erste Lanthanoid(IV)-Element-Mehrfachbindung; dabei binden Cer und Kohlenstoff ueber zwei Elektronenpaare.

Tris(cyclohexylammonium cis-dichloridobis(oxalato-κ2O1,O2stannate(IV chloride monohydrate

Directory of Open Access Journals (Sweden)

Modou Sarr

2013-11-01

Full Text Available The crystal structure of the title compound, (C6H14N3[Sn(C2O42Cl2]Cl·H2O, contains three cyclohexylammonium cations, one stannate(IV dianion, one isolated chloride anion and one lattice water molecule. The cyclohexylammonium cations adopt chair conformations. In the complex anion, two bidentate oxalate ligands and two chloride anions in cis positions coordinate octahedrally to the central SnIV atom. The cohesion of the molecular entities is ensured by the formation of N—H...O, O—H...O, O—H...Cl and N—H...Cl interactions involving cations, anions and the lattice water molecule, giving rise to a layer-like arrangement parallel to (010.

A new optical sensor for spectrophotometric determination of uranium (VI) and thorium (IV) in acidic medium

Energy Technology Data Exchange (ETDEWEB)

Elhefnawy, O.A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Nuclear Safeguards and Physical Protection Dept.

2017-07-01

A spectrophotometric method was developed for U(VI) and Th(IV) determination in acidic medium by using proposed optical sensor. This sensor is base on the complexation reaction of the ionophore midodrine hydrochloride (L) with U(VI)/Th(IV) in plasticized (o-NPOE) high molecular weight (PVC). Several parameters such as effect of acidic medium, response time and sensor compositions were studied. The determination of the complexes stoichiometry was also studied using Job's method. The complexes stoichiometry were measured at the absorbance spectra 302 nm and the results were found to be 1:1 for both complexes U(VI)-L and Th(IV)-L. The complexation reaction was extremely rapid at room temperature; it takes 5, 10 min to complete the complexation reaction in U(VI) and Th(IV), respectively. Under the optimum conditions the calibration curves of U(VI)/Th(IV) determination, have good linearity at different acidic medium nitric, sulfuric, and phosphoric acids with low detection and quantification limits. The accuracy and precision studies proved that the proposed optical sensor is valid and qualified for U(VI)/Th(IV) spectrophotometric determination in different acidic medium. The selectivity of the proposed optical sensor was studied. The proposed optical sensor was applied successfully for U(VI)/Th(IV) determination in research and development (R and D) nuclear waste samples with satisfactory results. A comparative study of the proposed optical sensor with other previous spectrophotometric sensors for U(VI)/Th(IV) determination, proved the high efficiency of the proposed optical sensor, that it presents wide linear range and low detection limit. The proposed optical sensor could be applied for a quantitative determination of U(VI)/Th(IV) in acidic waste samples.

A new optical sensor for spectrophotometric determination of uranium (VI) and thorium (IV) in acidic medium

International Nuclear Information System (INIS)

Elhefnawy, O.A.

2017-01-01

A spectrophotometric method was developed for U(VI) and Th(IV) determination in acidic medium by using proposed optical sensor. This sensor is base on the complexation reaction of the ionophore midodrine hydrochloride (L) with U(VI)/Th(IV) in plasticized (o-NPOE) high molecular weight (PVC). Several parameters such as effect of acidic medium, response time and sensor compositions were studied. The determination of the complexes stoichiometry was also studied using Job's method. The complexes stoichiometry were measured at the absorbance spectra 302 nm and the results were found to be 1:1 for both complexes U(VI)-L and Th(IV)-L. The complexation reaction was extremely rapid at room temperature; it takes 5, 10 min to complete the complexation reaction in U(VI) and Th(IV), respectively. Under the optimum conditions the calibration curves of U(VI)/Th(IV) determination, have good linearity at different acidic medium nitric, sulfuric, and phosphoric acids with low detection and quantification limits. The accuracy and precision studies proved that the proposed optical sensor is valid and qualified for U(VI)/Th(IV) spectrophotometric determination in different acidic medium. The selectivity of the proposed optical sensor was studied. The proposed optical sensor was applied successfully for U(VI)/Th(IV) determination in research and development (R and D) nuclear waste samples with satisfactory results. A comparative study of the proposed optical sensor with other previous spectrophotometric sensors for U(VI)/Th(IV) determination, proved the high efficiency of the proposed optical sensor, that it presents wide linear range and low detection limit. The proposed optical sensor could be applied for a quantitative determination of U(VI)/Th(IV) in acidic waste samples.

Poika on suruissansa (2/4 F)

OpenAIRE

2011-01-01

Laulun sanat: Poika on suruissansa, kun on jäänyt kullastansa; kiertää piirin ympäri ja ottaa uuden taas, kiertää piirin ympäri ja ottaa uuden taas! Hih-hei, ja pili-pam-pam-pam, pili-pam-pam-pam, pili-pam-pam-pam! Hih-hei, ja pili-pam-pam-pam! Kiertää piirin ympäri ja

Polymerization of acrylamide initiated with Ce(IV- and KMnO4–mercaptosuccinic acid redox systems in acid-aqueous medium

Directory of Open Access Journals (Sweden)

2007-03-01

Full Text Available By using mercaptosuccinic acid-cerium(IV sulfate and mercaptosuccinic acid-KMnO4 redox systems in acid aqueous medium, the polymerization of acrylamide monomer was performed at room temperatures. Water soluble acrylamide polymers which contain mercaptosuccinic acid end-groups were synthesized. The dependence of polymerization yield and the molecular weight of polymer on the initiator concentration(nMSA=nCe(IV at different acid concentrations, polymerization time, temperature, and concentration of sulfuric acid was investigated. The decrease in the initiator concentration resulted in an increase in the molecular weights but a decrease in the yield. The increase of reaction temperature from 20 to 60°C resulted in an increase in the molecular weights and slight decrease of the yield of polymer. Cerium and manganese ions are reduced to Ce(III and Mn(II ions respectively in polymerization reaction. The existence of Ce(III ion bound to polymer was investigated by UV-visible spectrometry and fluorescence measurements. The amount of Mn(II which is incorporated to the polymer was determined.

Identification of novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in camel milk protein hydrolysates.

Science.gov (United States)

Nongonierma, Alice B; Paolella, Sara; Mudgil, Priti; Maqsood, Sajid; FitzGerald, Richard J

2018-04-01

Nine novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides (FLQY, FQLGASPY, ILDKEGIDY, ILELA, LLQLEAIR, LPVP, LQALHQGQIV, MPVQA and SPVVPF) were identified in camel milk proteins hydrolysed with trypsin. This was achieved using a sequential approach combining liquid chromatography tandem mass spectrometry (LC-MS/MS), qualitative/quantitative structure activity relationship (QSAR) and confirmatory studies with synthetic peptides. The most potent camel milk protein-derived DPP-IV inhibitory peptides, LPVP and MPVQA, had DPP-IV half maximal inhibitory concentrations (IC 50 ) of 87.0 ± 3.2 and 93.3 ± 8.0 µM, respectively. DPP-IV inhibitory peptide sequences identified within camel and bovine milk protein hydrolysates generated under the same hydrolysis conditions differ. This was linked to differences in enzyme selectivity for peptide bond cleavage of camel and bovine milk proteins as well as dissimilarities in their amino acid sequences. Camel milk proteins contain novel DPP-IV inhibitory peptides which may play a role in the regulation of glycaemia in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structure of the CFA/III major pilin subunit CofA from human enterotoxigenic Escherichia coli determined at 0.90 Å resolution by sulfur-SAD phasing.

Science.gov (United States)

Fukakusa, Shunsuke; Kawahara, Kazuki; Nakamura, Shota; Iwashita, Takaki; Baba, Seiki; Nishimura, Mitsuhiro; Kobayashi, Yuji; Honda, Takeshi; Iida, Tetsuya; Taniguchi, Tooru; Ohkubo, Tadayasu

2012-10-01

CofA, a major pilin subunit of colonization factor antigen III (CFA/III), forms pili that mediate small-intestinal colonization by enterotoxigenic Escherichia coli (ETEC). In this study, the crystal structure of an N-terminally truncated version of CofA was determined by single-wavelength anomalous diffraction (SAD) phasing using five sulfurs in the protein. Given the counterbalance between anomalous signal strength and the undesired X-ray absorption of the solvent, diffraction data were collected at 1.5 Å resolution using synchrotron radiation. These data were sufficient to elucidate the sulfur substructure at 1.38 Å resolution. The low solvent content (29%) of the crystal necessitated that density modification be performed with an additional 0.9 Å resolution data set to reduce the phase error caused by the small sulfur anomalous signal. The CofA structure showed the αβ-fold typical of type IVb pilins and showed high structural homology to that of TcpA for toxin-coregulated pili of Vibrio cholerae, including spatial distribution of key residues critical for pilin self-assembly. A pilus-filament model of CofA was built by computational docking and molecular-dynamics simulation using the previously reported filament model of TcpA as a structural template. This model revealed that the CofA filament surface was highly negatively charged and that a 23-residue-long loop between the α1 and α2 helices filled the gap between the pilin subunits. These characteristics could provide a unique binding epitope for the CFA/III pili of ETEC compared with other type IVb pili.

Dissociative recombination of small molecular ions

International Nuclear Information System (INIS)

Mul, P.M.

1981-01-01

In this thesis an analysis is given of merged electron-ion beam experiment and work on dissociative recombination of molecular ions and electrons is described. Chapter II covers a brief introduction of the theory of dissociative recombination. In chapter III, a description is given of the merged electron-ion beam experiment and a method is described which allows the determination of the mean angle between the electron and ion trajectories in a merged electron-ion beam experiment. In chapter IV a paper on the three dominant atmospheric diatomic ions NO + , O 2 + and N 2 + is presented and in chapter V the dissociative recombination for N 2 H + and N 2 D + is discussed. In chapter VI two papers on the polyatomic ions of the carbon-containing molecular ions are presented, and in chapter VII a letter with some results of the work presented in more detail in the chapters IV, V and VI is presented. The magnitude and the energy dependence of the cross-section measured by the merged beam technique and by other techniques is compared and discussed. (Auth.)

SOYBEAN - MOLECULAR ASPECTS OF BREEDING

Directory of Open Access Journals (Sweden)

Aleksandra Sudarić

2012-12-01

Full Text Available The book Soybean: Molecular Aspects of Breeding focuses recent progress in our understanding of the genetics and molecular biology of soybean. This book is divided into four parts and contains 22 chapters. Part I, Molecular Biology and Biotechnology focuses advances in molecular biology and laboratory procedures that have been developed recently to manipulate DNA. Part II, Breeding for abiotic stress covers proteomics approaches form as a powerful tool for investigating the molecular mechanisms of the plant responses to various types of abiotic stresses. Part III, Breeding for biotic stress addresses issues related to application of molecular based strategies in order to increase soybean resistance to various biotic factors. Part IV, Recent Technology reviews recent technologies into the realm of soybean monitoring, processing and product use. While the information accumulated in this book is of primary interest for plant breeders, valuable insights are also offered to agronomists, molecular biologists, physiologists, plant pathologists, food scientists and students. The book is a result of efforts made by many experts from different countries (USA, Japan, Croatia, Serbia, China, Canada, Malawi, Iran, Hong Kong, Brasil, Mexico.

Goodpasture's autoimmune disease - A collagen IV disorder.

Science.gov (United States)

Pedchenko, Vadim; Richard Kitching, A; Hudson, Billy G

2018-05-12

Goodpasture's (GP) disease is an autoimmune disorder characterized by the deposition of pathogenic autoantibodies in basement membranes of kidney and lung eliciting rapidly progressive glomerulonephritis and pulmonary hemorrhage. The principal autoantigen is the α345 network of collagen IV, which expression is restricted to target tissues. Recent discoveries include a key role of chloride and bromide for network assembly, a novel posttranslational modification of the antigen, a sulfilimine bond that crosslinks the antigen, and the mechanistic role of HLA in genetic susceptibility and resistance to GP disease. These advances provide further insights into molecular mechanisms of initiation and progression of GP disease and serve as a basis for developing of novel diagnostic tools and therapies for treatment of Goodpasture's disease. Copyright © 2017. Published by Elsevier B.V.

Complexes of uranium (IV) and thorium (IV) with α-picolinic acid, nicotinic acid, anthranilic acid and N-phenylanthranilic acid

International Nuclear Information System (INIS)

Singh, M.; Singh, R.

1979-01-01

Stable U(IV) and Th(IV) complexes with the title ligands have been synthesised from U(OAc) 4 , and Th(OAc) 4 . Magnetic susceptibilities, IR and reflectance spectra of U(IV) and IR spectra of Th(IV) complexes have been studied which indicate eight coordination for U(IV) in these chelates. (auth.)

Solubility of Tc(IV) oxides

International Nuclear Information System (INIS)

Liu, D.J.; Fan, X.H.

2005-01-01

Full text of publication follows: The deep geological disposal of the high level radioactive wastes is expected to be a safer disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 .nH 2 O. The solubility of Tc(IV) is used as a source term in performance assessment of radioactive waste repository. Technetium oxide was prepared by reduction of a technetate solution with Sn 2+ . The solubility of Tc(IV) oxide has been determined in simulated groundwater and re-distilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) oxide were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and re-distilled water is about (1.49∼1.86) x 10 -9 mol/(L.d) under aerobic conditions, but Tc(IV) in simulated groundwater and re-distilled water is not oxidized under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) oxide in simulated groundwater and re-distilled water is equal on the whole after centrifugation or ultrafiltration. The solubility of Tc(IV) oxide decreases with the increase of pH at pH 10 and is pH independent in the range 2 -8 to 10 -9 mol/L at 2 3 2- concentration. These data could be used to estimate the Tc(IV) solubility for cases where solubility limits transport of technetium in reducing environments of high-level waste repositories. (authors)

Enhanced selectivity in non-heme iron catalysed oxidation of alkanes with peracids : evidence for involvement of Fe(IV)=O species

NARCIS (Netherlands)

Berg, Tieme A. van den; Boer, Johannes W. de; Browne, Wesley R.; Roelfes, Gerard; Feringa, Bernard

2004-01-01

Catalytic alkane oxidation with high selectivity using peracids and an (N4Py)Fe complex is presented and the role of [(N4Py)Fe(IV)=O]2+ species, molecular oxygen and hydroxyl radicals in the catalysis is discussed.

On the room-temperature phase diagram of high pressure hydrogen: An ab initio molecular dynamics perspective and a diffusion Monte Carlo study

International Nuclear Information System (INIS)

Chen, Ji; Ren, Xinguo; Li, Xin-Zheng; Alfè, Dario; Wang, Enge

2014-01-01

The finite-temperature phase diagram of hydrogen in the region of phase IV and its neighborhood was studied using the ab initio molecular dynamics (MD) and the ab initio path-integral molecular dynamics (PIMD). The electronic structures were analyzed using the density-functional theory (DFT), the random-phase approximation, and the diffusion Monte Carlo (DMC) methods. Taking the state-of-the-art DMC results as benchmark, comparisons of the energy differences between structures generated from the MD and PIMD simulations, with molecular and dissociated hydrogens, respectively, in the weak molecular layers of phase IV, indicate that standard functionals in DFT tend to underestimate the dissociation barrier of the weak molecular layers in this mixed phase. Because of this underestimation, inclusion of the quantum nuclear effects (QNEs) in PIMD using electronic structures generated with these functionals leads to artificially dissociated hydrogen layers in phase IV and an error compensation between the neglect of QNEs and the deficiencies of these functionals in standard ab initio MD simulations exists. This analysis partly rationalizes why earlier ab initio MD simulations complement so well the experimental observations. The temperature and pressure dependencies for the stability of phase IV were also studied in the end and compared with earlier results

Visualization of Twitching Motility and Characterization of the Role of the PilG in Xylella fastidiosa.

Science.gov (United States)

Shi, Xiangyang; Lin, Hong

2016-04-08

Xylella fastidiosa is a Gram-negative non-flagellated bacterium that causes a number of economically important diseases of plants. The twitching motility provides X. fastidiosa a means for long-distance intra-plant movement and colonization, contributing toward pathogenicity in X. fastidiosa. The twitching motility of X. fastidiosa is operated by type IV pili. Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in Pil-Chp operon encoding proteins that are involved with signal transduction pathways. To elucidate the roles of pilG in the twitching motility of X. fastidiosa, a pilG-deficient mutant XfΔpilG and its complementary strain XfΔpilG-C containing native pilG were developed. A microfluidic chambers integrated with a time-lapse image recording system was used to observe twitching motility in XfΔpilG, XfΔpilG-C and its wild type strain. Using this recording system, it permits long-term spatial and temporal observations of aggregation, migration of individual cells and populations of bacteria via twitching motility. X. fastidiosa wild type and complementary XfΔpilG-C strain showed typical twitching motility characteristics directly observed in the microfluidic flow chambers, whereas mutant XfΔpliG exhibited the twitching deficient phenotype. This study demonstrates that pilG contributes to the twitching motility of X. fastidiosa. The microfluidic flow chamber is used as a means for observing twitching motility.

Successful application of virtual screening and molecular dynamics simulations against antimalarial molecular targets

Directory of Open Access Journals (Sweden)

Renata Rachide Nunes

Full Text Available The main challenge in the control of malaria has been the emergence of drug-resistant parasites. The presence of drug-resistant Plasmodium sp. has raised the need for new antimalarial drugs. Molecular modelling techniques have been used as tools to develop new drugs. In this study, we employed virtual screening of a pyrazol derivative (Tx001 against four malaria targets: plasmepsin-IV, plasmepsin-II, falcipain-II, and PfATP6. The receiver operating characteristic curves and area under the curve (AUC were established for each molecular target. The AUC values obtained for plasmepsin-IV, plasmepsin-II, and falcipain-II were 0.64, 0.92, and 0.94, respectively. All docking simulations were carried out using AutoDock Vina software. The ligand Tx001 exhibited a better interaction with PfATP6 than with the reference compound (-12.2 versus -6.8 Kcal/mol. The Tx001-PfATP6 complex was submitted to molecular dynamics simulations in vacuum implemented on an NAMD program. The ligand Tx001 docked at the same binding site as thapsigargin, which is a natural inhibitor of PfATP6. Compound TX001 was evaluated in vitro with a P. falciparum strain (W2 and a human cell line (WI-26VA4. Tx001 was discovered to be active against P. falciparum (IC50 = 8.2 µM and inactive against WI-26VA4 (IC50 > 200 µM. Further ligand optimisation cycles generated new prospects for docking and biological assays.

Synthesis and characterization of an exact comb polyisoprene with three branches having the middle branch twice the molecular weight of the other two identical external branches

KAUST Repository

Ratkanthwar, Kedar; Hadjichristidis, Nikolaos; Lee, Sanghoon; Chang, Taihyun; Pudukulathan, Zubaidha; Vlassopoulos, Dimitris

2013-01-01

chlorosilane chemistry. The synthetic approach involves (a) the selective replacement of the two chlorines of 4-(dichloromethylsilyl) diphenylethylene (DCMSDPE, key molecule) with identical PI chains by titration with PILi, (b) the addition of sec

On the stabilization of niobium(V) solutions by zirconium(IV) and hafnium(IV)

DEFF Research Database (Denmark)

Sørensen, E.; Bjerre, A.B.

1992-01-01

Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as chloride and sulphate. This is ascribed to the co-polymerization of niobium(V) and the hydrolysed ionic species of zirconium(IV) and hafnium(IV) to form colloidal...

Neptunium (IV) oxalate solubility

International Nuclear Information System (INIS)

Luerkens, D.W.

1983-07-01

The equilibrium solubility of neptunium (IV) oxalate in nitric/oxalic acid solutions was determined at 22 0 C, 45 0 C, and 60 0 C. The concentrations of nitric/oxalic acid solutions represented a wide range of free oxalate ion concentration. A mathematical solubility model was developed which is based on the formation of the known complexes of neptunium (IV) oxalate. the solubility model uses a simplified concentration parameter which is proportional to the free oxalate ion concentration. The solubility model can be used to estimate the equilibrium solubility of neptunium (IV) oxalate over a wide range of oxalic and nitric acid concentrations at each temperature

Enhanced Design Alternative IV

International Nuclear Information System (INIS)

Kramer, N.E.

1999-01-01

This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the Design Input Request for LADS Phase II EDA Evaluations (CRWMS M and O 1999b) and (CRWMS M and O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as line load. Continuous pre-closure ventilation keeps the waste packages from exceeding their 350 C cladding and 200 C (4.3.6) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and drip shields will be emplaced at closure to improve post-closure performance. The EDA IV concept includes more defense-in-depth layers than the VA reference design because of its backfill, drip shield, waste package shielding, and integral filler features. These features contribute to the low dose-rate to the public achieved during the first 10,000 years of repository life as shown in Figure 3. Investigation of the EDA IV concept has led to the following general conclusions: (1) The total life cycle cost for EDA IV is about $21.7 billion which equates to a $11.3 billion net present value (both figures rounded up). (2) The incidence of design basis events for EDA IV is similar to the VA reference design. (3) The emplacement of the waste packages in drifts will be similar to the VA reference design. However, heavier equipment may be required because the shielded waste package will be heavier. (4) The heavier

Spectroscopic Study of the Interaction between Horse Heart Myoglobin and Zirconium(IV)-Substituted Polyoxometalates as Artificial Proteases.

Science.gov (United States)

Ly, Hong Giang T; Parac-Vogt, Tatjana N

2017-09-20

A recent study [Angew. Chem. Int. Ed. 2015, 54, 7391-7394] has shown that horse heart myoglobin (HHM) is selectively hydrolyzed by a range of zirconium(IV)-substituted polyoxometalates (POMs) under mild conditions. In this study, the molecular interactions between the Zr-POM catalysts and HHM are investigated by using a range of complementary techniques, including circular dichroism (CD), UV/Vis spectroscopy, tryptophan fluorescence spectroscopy, and 1 H and 31 P NMR spectroscopy. A tryptophan fluorescence quenching study reveals that, among all examined Zr-POMs, the most reactive POM, 2:2 Zr IV -Keggin, exhibits the strongest interaction with HHM. 31 P NMR spectroscopy studies show that this POM dissociates in solution, resulting in the formation of a monomeric 1:1 Zr IV -Keggin structure, which is likely to be a catalytically active species. In the presence of Zr IV -POMs, HHM does not undergo complete denaturation, as evidenced by CD, UV/Vis, tryptophan fluorescence, and 1 H NMR spectroscopy. CD spectroscopy shows a gradual decrease in the α-helical content of HHM upon addition of Zr IV -POMs. The largest effect is observed in the presence of a large Zr IV -Wells-Dawson structure, whereas small Zr IV -Lindqvist POM has the least influence on the decrease in the α-helical content of HHM. In all cases, the Soret band at λ=409 nm is maintained in the presence of all examined Zr-POMs, which indicates that no conformational changes in the protein occur near the heme group. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Astragaloside IV Downregulates β-Catenin in Rat Keratinocytes to Counter LiCl-Induced Inhibition of Proliferation and Migration

Directory of Open Access Journals (Sweden)

Fu-Lun Li

2012-01-01

Full Text Available Re-epithelialization is a crucial step towards wound healing. The traditional Chinese medicine, Astragalus membranaceus (Fisch Bge, has been used for hundreds of years for many kinds of ulcerated wounds. Recent research has identified the active compound in this drug as astragaloside IV (AS-IV, but the underlying molecular mechanisms of its therapeutic action on keratinocytes remain poorly understood. In this study, we used an in vitro model of ulcer-like wound processes, lithium chloride (LiCl-induced cultured mouse keratinocytes, to investigate the effects of AS-IV treatment. The effects on cell proliferation were evaluated by the MTS/PMS colorimetric assay, effects on cell migration were determined by a wound-healing scratch experiment, effects on the cell cycle were analyzed by flow cytometry, and effects on protein expression were analyzed by immunoblotting and immunofluorescence. LiCl strongly inhibited cell proliferation and migration, up-regulated β-catenin expression, and down-regulated proliferating cell nuclear antigen (PCNA expression. AS-IV treatment attenuat the inhibition of proliferation and migration, significantly reducing the enhanced β-catenin expression, and recovering PCNA and β-tubulin expression. Thus, AS-IV mediates mouse keratinocyte proliferation and migration via regulation of the Wnt signaling pathway. Down-regulating β-catenin to increase keratinocyte migration and proliferation is one mechanism by which AS-IV can promote ulcerated wound healing.

Role of Mitochondrial Complex IV in Age-Dependent Obesity

Directory of Open Access Journals (Sweden)

Ines Soro-Arnaiz

2016-09-01

Full Text Available Aging is associated with progressive white adipose tissue (WAT enlargement initiated early in life, but the molecular mechanisms involved remain unknown. Here we show that mitochondrial complex IV (CIV activity and assembly are already repressed in white adipocytes of middle-aged mice and involve a HIF1A-dependent decline of essential CIV components such as COX5B. At the molecular level, HIF1A binds to the Cox5b proximal promoter and represses its expression. Silencing of Cox5b decreased fatty acid oxidation and promoted intracellular lipid accumulation. Moreover, local in vivo Cox5b silencing in WAT of young mice increased the size of adipocytes, whereas restoration of COX5B expression in aging mice counteracted adipocyte enlargement. An age-dependent reduction in COX5B gene expression was also found in human visceral adipose tissue. Collectively, our findings establish a pivotal role for CIV dysfunction in progressive white adipocyte enlargement during aging, which can be restored to alleviate age-dependent WAT expansion.

A further insight into the biosorption mechanism of Pt(IV by infrared spectrometry

Directory of Open Access Journals (Sweden)

Xu Zhenling

2009-07-01

Full Text Available Abstract Background Platinum nanomaterial is one of the significant noble metal catalysts, and the interaction of platinum with microbe is one of the key factors in influencing the size and the distribution of the platinum nanoparticles on the microbial biomass. Some properties of Pt(IV adsorption and reduction by resting cells of Bacillus megatherium D01 biomass have once been investigated, still the mechanism active in the platinum biosorption remains to be seen and requires further elucidating. Result A further insight into the biosorption mechanism of Pt(IV onto resting cells of Bacillus megatherium D02 biomass on a molecular level has been obtained. The image of scanning electron microscopy (SEM of the D02 biomass challenged with Pt(IV displayed a clear distribution of bioreduced platinum particles with sizes of nanometer scale on the biomass. The state of Pt(IV bioreduced to elemental Pt(0 examined via X-ray photoelectron spectroscopy (XPS suggested that the biomass reduces the Pt(IV to Pt(II followed by a slower reduction to Pt(0. The analysis of glucose content in the hydrolysates of D02 biomass for different time intervals using ultraviolet-visible (UV-vis spectrophotometry indicated that certain reducing sugars occur in the hydrolyzed biomass and that the hydrolysis of polysaccharides of the biomass is a rapid process. The infrared (IR spectrometry on D02 biomass and that challenged with Pt(IV, and on glucose and that reacted with Pt(IV demonstrated that the interaction of the biomass with Pt(IV seems to be through oxygenous or nitrogenous chemical functional groups on the cell wall biopolymers; that the potential binding sites for Pt species include hydroxyl of saccharides, carboxylate anion and carboxyl of amino acid residues, peptide bond, etc.; and that the free monosaccharic group bearing hemiacetalic hydroxyl from the hydrolyzed biomass behaving as an electron donor, in situ reduces the Pt(IV to Pt(0. And moreover, the binding of

Anomalous I-V curve for mono-atomic carbon chains

International Nuclear Information System (INIS)

Song Bo; Fang Haiping; Sanvito, Stefano

2010-01-01

The electronic transport properties of mono-atomic carbon chains were studied theoretically using a combination of density functional theory and the non-equilibrium Green's functions method. The I-V curves for the chains composed of an even number of atoms and attached to gold electrodes through sulfur exhibit two plateaus where the current becomes bias independent. In contrast, when the number of carbon atoms in the chain is odd, the electric current simply increases monotonically with bias. This peculiar behavior is attributed to dimerization of the chains, directly resulting from their one-dimensional nature. The finding is expected to be helpful in designing molecular devices, such as carbon-chain-based transistors and sensors, for nanoscale and biological applications.

Electrochemically assisted mechanically controllable break junction studies on the stacking configurations of oligo(phenylene ethynylene)s molecular junctions

International Nuclear Information System (INIS)

Zheng, Jue-Ting; Yan, Run-Wen; Tian, Jing-Hua; Liu, Jun-Yang; Pei, Lin-Qi; Wu, De-Yin; Dai, Ke; Yang, Yang; Jin, Shan

2016-01-01

Highlights: • I-V characteristics of a series of oligo(phenylene ethynylene)s molecular junctions were measured. • Conductance values were found to be dependent on molecular length and substituent group. • The measured low conductance values were explained by theoretical calculations. • EC-MCBJ is feasible to fabricate and characterize molecular junctions. - Abstract: We demonstrate an electrochemically assisted mechanically controllable break junction (EC-MCBJ) approach for current-voltage characteristic (I-V curve) measurements of metal/molecule/metal junctions. A series of oligo(phenylene ethynylene)s compounds (OPEs), including those involving electron withdrawing substituent group and different backbone lengths, had been successfully designed, synthesized, and placed onto the fabricated nanogap to form molecular junctions. The observed evolution in the measured conductances of OPEs indicates that there is a dependence of conductance on molecular length and substituent group. Compared with those extracted from conductance histogram construction, the conductances of OPEs measured from I-V curves are considerably lower. Based on the transmission spectra of OPEs that calculated by density functional theory (DFT) combined with non-equilibrium Green’s function (NEGF) method, this difference was attributed to our distinct experimental operation, which may give rise to a stacking configuration of two OPE molecules.

The kinetics of the cerium(IV)-uranium(IV) reaction at low sulfate concentrations

International Nuclear Information System (INIS)

Michaille, P.; Kikindai, T.

1977-01-01

The rate of oxidation of uranium(IV) by cerium(IV) was measured with a stopped-flow spectrophotometer at sulfuric acid concentrations of 2 x 10 -6 to 0.5 M. At a constant hydrogen ion concentration of 0.5 M, the maximum rate constant was observed for 2 x 10 -3 M sulfuric acid; at that concentration, two sulfate ions were involved in the activated complex. The dependence of the rate constant on the hydrogen ion concentration showed that the reaction paths involving one or two sulfate ions also involved one hydroxyl ion, whereas one hydrogen ion was involved in the five sulfate dependent path. Spectrophotometric measurements supported the existence of a hydrolyzed monosulfatocomplex of cerium(IV). (author)

Diorganotin(IV) Complexes with Methionine Methyl Ester. Equilibria ...

African Journals Online (AJOL)

IV) (DBT) and diphenyltin(IV) (DPT) was investigated at 25 °C and 0.1 mol dm–3 ionic strength in water for dimethyltin(IV) and in 50 % dioxane–water mixture for dibutyltin(IV) and diphenyltin(IV). Methionine methyl ester forms1:1 and 1:2 ...

Immunohistochemical Analysis of Collagen IV and Laminin Expression in Spontaneous Melanoma Regression in the Melanoma-Bearing Libechov Minipig

Czech Academy of Sciences Publication Activity Database

Plánská, Daniela; Burocziová, Monika; Strnádel, Ján; Horák, Vratislav

2015-01-01

Roč. 48, č. 1 (2015), s. 15-26 ISSN 0044-5991 R&D Projects: GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 ; RVO:61388971 Keywords : collagen IV * laminin * MeLiM * porcine melanoma * spontaneous regression Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.912, year: 2015

Adsorption of Th(IV) and Pu(IV) on the surface of Pseudomonas fluorescens and Bacillus subtilis in the presence of desferrioxamine siderophore

International Nuclear Information System (INIS)

Yoshida, Takahiro; Ozaki, Takuo; Ohnuki, Toshihiko; Francis, Arokiasamy J.

2005-01-01

Adsorption of Th(IV) and Pu(IV) on a Gram-negative bacterium Pseudomonas fluorescens and a Gram-positive bacterium Bacillus subtilis in the presence of siderophore desferrioxamine B (DFO) was studied. Thorium(IV) and Pu(IV) were dissociated from DFO during adsorption on the cells. Thorium(IV) adsorption on bacterial cells in the presence of DFO was larger than that of Pu(IV) because of the smaller stability of the Th(IV)-DFO complex than that of the Pu(IV)-DFO complex. On the other hand, adsorption of Pu(IV) was larger than that of Fe(III), wherein the stability of the Pu(IV)- and Fe(III)-DFO complex is comparable. P. fluorescens showed a higher affinity for Th(IV) and Pu(IV) than B. subtilis, though potentiometric titration of bacterial cells indicated that surfaces of P. fluorescens and B. subtilis cells showed similar proton binding properties. (author)

A combined XAFS, ESI TOF-MS and LIBD study on the formation of polynuclear Zr(IV), Th(IV) and Pu(IV) species

Science.gov (United States)

Rothe, J.; Walther, C.; Brendebach, B.; Büchner, S.; Fuss, M.; Denecke, M. A.; Geckeis, H.

2009-11-01

The long term radiotoxicity of spent nuclear fuel disposed of in deep underground repositories after discharge from nuclear power reactors is determined by actinide elements, mainly plutonium. Water intrusion into the repository might cause container corrosion and leaching of the waste matrices, leading to the release of Pu and other actinides into the geological environment. Performance assessment for a future nuclear waste repository requires detailed knowledge on actinide aqueous chemistry in the aquifer surrounding the disposal site. Tetravalent actinides exhibit a strong tendency towards hydrolysis and subsequent polymerization and/or colloid formation. These species provide a potential pathway for migration of actinides away from the repository. Therefore, it is of fundamental interest to study their generation and properties in-situ. To this end, X-ray Absorption Fine Structure Spectroscopy (XAFS) at the INE-Beamline for actinide research at ANKA, Electrospray Mass-Spectrometry (ESI TOF-MS) and Laser Induced Breakdown Detection (LIBD) are combined at FZK-INE in a comprehensive attempt to characterize Zr(IV) (An(IV) analogue), Th(IV) and Pu(IV) polymerization and colloid formation.

Structural organization and spectroscopy of peptide-actinide(IV) complexes

International Nuclear Information System (INIS)

Dahou, S.

2010-01-01

The contamination of living organisms by actinide elements is at the origin of both radiological and chemical toxicity that may lead to severe dysfunction. Most of the data available on the actinide interaction with biological systems are macroscopic physiological measurements and are lacking a molecular description of the systems. Because of the intricacy of these systems, classical biochemical methods are difficult to implement. Our strategy consisted in designing simplified biomimetic peptides, and describing the corresponding intramolecular interactions with actinides. A carboxylic pentapeptide of the form DDPDD has been at the starting point of this work in order to further assess the influence of the peptide sequence on the topology of the complexes.To do so, various linear (Asp/Ala permutations, peptoids) and cyclic analogues have been synthesized. Furthermore, in order to include the hydroxamic function (with a high affinity for Fe(III)) in the peptide, both desferrioxamine and acetohydroxamic acid have been investigated. However because of difficulties in synthesis, we have not been able to test these peptides. Three actinide cations have been considered at oxidation state +IV (Th, Np, Pu) and compared to Fe(III), often considered as a biological surrogate of Pu(IV). The spatial arrangement of the peptide around the cation has been probed by spectrophotometry and X-ray Absorption Spectroscopy. The spectroscopic data and EXAFS data adjustment lead us to rationalize the topology of the complexes as a function of the peptide sequence: mix hydroxy polynuclear species for linear and cyclic peptides, mononuclear for the desferrioxamine complexes. Furthermore, significant differences have appeared between Fe(III) and actinide(IV), related to differences of reactivity in aqueous medium. (author)

Generation IV national program

International Nuclear Information System (INIS)

Preville, M.; Sadhankar, R.; Brady, D.

2007-01-01

This paper outlines the Generation IV National Program. This program involves evolutionary and innovative design with significantly higher efficiencies (∼50% compared to present ∼30%) - sustainable, economical, safe, reliable and proliferation resistant - for future energy security. The Generation IV Forum (GIF) effectively leverages the resources of the participants to meet these goals. Ten countries signed the GIF Charter in 2001

Emulsifier-free emulsion polymerization of tetrafluoroethylene by radiation. IV. Effects of additives on Polymer molecular weight

International Nuclear Information System (INIS)

Watanabe, T.; Suwa, T.; Okamoto, J.; Machi, S.

1979-01-01

Poly(tetrafluoroethylene)(PTFE) of high molecular weight, 4.5 x 10 7 , was incidentally obtained at earlier study of an emulsifier-free emulsion polymerization of tetrafluoroethylene by radiation. In order to clarify this phenomenon, the effects of additives, in particular radical scavengers, on the molecular weight of PTFE and its polymerization behavior were studied. It was found that the molecular weight of PTFE is increased by the addition of hydroquinone, benzoquinone, α-pinene, dl-limonene, and ethylenediamine but is decreased by oxygen and triethylamine. A PTFE latex with molecular weight higher than 2 x 10 7 was obtained in the presence of hydroquinone. It is concluded that additives such as hydroquinone and benzaquinone, which rapidly scavenge the primary radicals (OH, H, and e/sub aq/ - ) in the aqueous phase but not the growing polymer radicals in PTFE particles, are most effective in increasing the molecular weight

Solubility studies of Np(IV)

International Nuclear Information System (INIS)

Zhang Yingjie; Yao Jun; Jiao Haiyang; Ren Lihong; Zhou Duo; Fan Xianhua

2001-01-01

The solubility of Np(IV) in simulated underground water and redistilled water has been measured with the variations of pH(6-12) and storage time (0-100 d) in the presence of reductant (Na 2 S 2 O 4 , metallic Fe). All experiments are performed in a low oxygen concentration glove box containing high purity Ar(99.99%), with an oxygen content of less than 5 x 10 -6 mol/mol. Experimental results show that the variation of pH in solution has little effect on the solubility of Np(IV) in the two kinds of water; the measured solubility of Np(IV) is affected by the composition of solution; with Na 2 S 2 O 4 as a reductant, the solubility of Np(IV) in simulated underground water is (9.23 +- 0.48) x 10 -10 mol/L, and that in redistilled water is (8.31 +- 0.35) x 10 -10 mol/L; with metallic Fe as a reductant, the solubility of Np(IV) in simulated underground water is (1.85 +- 0.56) x 10 -9 mol/L, and that in redistilled water is (1.48 +- 0.66) x 10 -9 mol/L

Comparison of high and low virulence serotypes of Actinobacillus pleuropneumoniae by quantitative real-time PCR

DEFF Research Database (Denmark)

Schou, Kirstine Klitgaard; Angen, Øystein; Boye, Mette

PCR data. Preliminary results showed that in both serotype 2 and serotype 6, the toxin producing gene apxIV was the most highly expressed of the investigated genes. The major difference observed between the two serotypes was that apfA, involved in type IV vili production, was significantly upregulated...... of high virulence while serotype 6 strains are normally found to be less pathogenic. To gain an understanding of the differential virulence of serotype 2 and 6, the expression of a panel of Ap genes during infection of porcine epithelial lung cells (SJPL) were examined by quantitative real-time PCR (q...... to be important for early establishment of the bacteria in the host were examined by qPCR. The genes examined were apfA, coding for a subunit of Type IV pili, kdsB coding for a gene involved in lippopolysacceride biosynthesis, and pgaB which is involved in biofilm formation, all three believed to be important...

Materials for generation-IV nuclear reactors

International Nuclear Information System (INIS)

Alvarez, M. G.

2009-01-01

Materials science and materials development are key issues for the implementation of innovative reactor systems such as those defined in the framework of the Generation IV. Six systems have been selected for Generation IV consideration: gas-cooled fast reactor, lead-cooled fast reactor, molten salt-cooled reactor, sodium-cooled fast reactor, supercritical water-cooled reactor, and very high temperature reactor. The structural materials need to resist much higher temperatures, higher neutron doses and extremely corrosive environment, which are beyond the experience of the current nuclear power plants. For this reason, the first consideration in the development of Generation-IV concepts is selection and deployment of materials that operate successfully in the aggressive operating environments expected in the Gen-IV concepts. This paper summarizes the Gen-IV operating environments and describes the various candidate materials under consideration for use in different structural applications. (author)

The mammalian homologue of yeast Afg1 ATPase (lactation elevated 1) mediates degradation of nuclear-encoded complex IV subunits

Czech Academy of Sciences Publication Activity Database

Česneková, J.; Rodinová, M.; Hansíková, H.; Houštěk, Josef; Zeman, J.; Stibůrek, L.

2016-01-01

Roč. 473, č. 6 (2016), s. 797-804 ISSN 0264-6021 R&D Projects: GA ČR(CZ) GA13-07223S Institutional support: RVO:67985823 Keywords : complex IV * LACE1 * mitochondria * oxidative phosphorylation * YME1L Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.797, year: 2016

Adduct formation in Ce(IV) thenolytrifluoroacetonate

International Nuclear Information System (INIS)

Anufrieva, S.I.; Polyakova, G.V.; Snezhko, N.I.; Pechurova, N.I.; Martynenko, L.I.; Spitsyn, V.I.

1982-01-01

The literature contains no information on adduct formation in Ce(IV) β-diketonates with additional ligands. Since tetrakis-β-diketonates of Ce(IV) have four six-membered chelate rings, we can suppose that the introduction of an additional monodentate or bidentate ligand into the coordination sphere of Ce(IV) β-diketonates would lead to an increase in the coordination number (CN) of the Ce(IV) to nine or ten. The possibility of realization of such a high CN for Ce(IV) has not been proved; a study of adduct formation by Ce(IV) tetrakis-β-diketonates is thus of theoretical interest. Such an investigation might also be of practical interest, because the introduction of an additional ligand into the coordination sphere of a rare-earth β-diketonate usually increases the solubility of the β-diketonate in nonpolar solvents and increases the volatility of the compound; such a modification of the properties is important for various practical purposes. The aim of our work was to study the possibility of separating solid adducts of Ce(IV) tetrakis-thenoyltrifluoroacetonate with certain oxygen-containing and nitrogen-containing donor monodentate and bidentate ligands, and also to investigate their properties. As the β-diketone we used thenoyltrifluoroacetone (HTTFA), since in a parallel investigation it was found that Ce(TTFA) 4 has a high oxidation-reduction stability

Phosphorene as a Superior Gas Sensor: Selective Adsorption and Distinct I-V Response.

Science.gov (United States)

Kou, Liangzhi; Frauenheim, Thomas; Chen, Changfeng

2014-08-07

Recent reports on the fabrication of phosphorene, that is, mono- or few-layer black phosphorus, have raised exciting prospects of an outstanding two-dimensional (2D) material that exhibits excellent properties for nanodevice applications. Here, we study by first-principles calculations the adsorption of CO, CO2, NH3, NO, and NO2 gas molecules on a monolayer phosphorene. Our results predict superior sensing performance of phosphorene that rivals or even surpasses that of other 2D materials such as graphene and MoS2. We determine the optimal adsorption positions of these molecules on the phosphorene and identify molecular doping, that is, charge transfer between the molecules and phosphorene, as the driving mechanism for the high adsorption strength. We further calculated the current-voltage (I-V) relation using the nonequilibrium Green's function (NEGF) formalism. The transport features show large (1-2 orders of magnitude) anisotropy along different (armchair or zigzag) directions, which is consistent with the anisotropic electronic band structure of phosphorene. Remarkably, the I-V relation exhibits distinct responses with a marked change of the I-V relation along either the armchair or the zigzag directions depending on the type of molecules. Such selectivity and sensitivity to adsorption makes phosphorene a superior gas sensor that promises wide-ranging applications.

Genetics Home Reference: glycogen storage disease type IV

Science.gov (United States)

... Home Health Conditions Glycogen storage disease type IV Glycogen storage disease type IV Printable PDF Open All ... Javascript to view the expand/collapse boxes. Description Glycogen storage disease type IV (GSD IV) is an ...

Proteolytic processing of lysyl oxidase-like-2 in the extracellular matrix is required for crosslinking of basement membrane collagen IV.

Science.gov (United States)

López-Jiménez, Alberto J; Basak, Trayambak; Vanacore, Roberto M

2017-10-13

Lysyl oxidase-like-2 (LOXL2) is an enzyme secreted into the extracellular matrix that crosslinks collagens by mediating oxidative deamination of lysine residues. Our previous work demonstrated that this enzyme crosslinks the 7S domain, a structural domain that stabilizes collagen IV scaffolds in the basement membrane. Despite its relevant role in extracellular matrix biosynthesis, little is known about the structural requirements of LOXL2 that enable collagen IV crosslinking. In this study, we demonstrate that LOXL2 is processed extracellularly by serine proteases, generating a 65-kDa form lacking the first two scavenger receptor cysteine-rich domains. Site-specific mutagenesis to prevent proteolytic processing generated a full-length enzyme that is active in vitro toward a soluble substrate, but fails to crosslink insoluble collagen IV within the extracellular matrix. In contrast, the processed form of LOXL2 binds to collagen IV and crosslinks the 7S domain. Together, our data demonstrate that proteolytic processing is an important event that allows LOXL2-mediated crosslinking of basement membrane collagen IV. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Separation of uranium(V I) from binary solution mixtures with thorium(IV), zirconium(IV) and cerium(III) by foaming

International Nuclear Information System (INIS)

Shakir, K.; Aziz, M.; Benyamin, K.

1992-01-01

Foam separation has been investigated for the removal of uranium(V I), thorium(IV), zirconium(IV) and cerium(III) from dilute aqueous solutions at pH values ranging from about I to about II. Sodium laurel sulphate (Na L S) and acetyl trimethyl ammonium bromide (CTAB), being a strong anionic and a strong cationic surfactants, were used as collectors. The results indicate that Na L S can efficiently remove thorium(IV), zirconium(IV) and cerium(III) but not uranium(V I). CTAB, on the other hand, can successfully float only uranium(V I) and zirconium(IV). These differences in flotation properties of the different cations could be used to establish methods for the separation of uranium(V I) from binary mixtures with thorium(IV), zirconium(IV) or cerium(III). The results are discussed in terms of the hydrolytic behaviour of the tested cations and properties of used collectors.2 fig., 1 tab

IUE observations of interstellar Si IV and C IV lines observed in the spectra of Wolf-Rayet stars

International Nuclear Information System (INIS)

Smith, L.J.; Willis, A.J.; Wilson, R.

1980-01-01

Recent IUE observations of Wolf-Rayet stars show narrow absorption lines in the highly ionized species of Si IV and C IV. The strengths of these 'interstellar' Si IV and C IV lines observed in the spectra of 10 WR stars and two other early-type stars are compared. Of the WR sample, six stars exhibit very strong Si IV and C IV lines (Wsub(lambda) approximately 0.3 to 0.5 A) whilst the other four stars show much weaker lines (Wsub(lambda) approximately 0.1 A). There is no correlation between the strengths of these lines with either stellar distance or colour excess. The weaker absorptions may arise in the individual stellar H II regions, the observed strengths being consistent with those expected for stars with Tsub(eff) = 30 000 K. Five of the other stars which exhibit very strong absorptions lie in the line of sight to active interstellar regions (Cygnus and Carina nebulae) and it is considered probable that, in addition to their H II region components, the bulk of the strong Si IV and C IV absorptions originate in hot gas associated with these active regions. In the case of the WN5 star HD 50896 violet-displaced components are observed in the interstellar lines of low ionization species. These are thought to be produced in the ring nebula S308 surrounding HD 50896. (author)

Current status of NPP generation IV

International Nuclear Information System (INIS)

Yohanes Dwi Anggoro; Dharu Dewi; Nurlaila; Arief Tris Yuliyanto

2013-01-01

Today development of nuclear technology has reached the stage of research and development of Generation IV nuclear power plants (advanced reactor systems) which is an innovative development from the previous generation of nuclear power plants. There are six types of power generation IV reactors, namely: Very High Temperature Reactor (VHTR), Sodium-cooled Fast Reactor (SFR), Gas-cooled Fast Reactor (GFR), Lead-cooled Fast Reactor (LFR), Molten Salt Reactor (MSR), and Super Critical Water-cooled Reactor (SCWR). The purpose of this study is to know the development of Generation IV nuclear power plants that have been done by the thirteen countries that are members of the Gen IV International Forum (GIF). The method used is review study and refers to various studies related to the current status of research and development of generation IV nuclear power. The result of this study showed that the systems and technology on Generation IV nuclear power plants offer significant advances in sustainability, safety and reliability, economics, and proliferation resistance and physical protection. In addition, based on the research and development experience is estimated that: SFR can be used optimally in 2015, VHTR in 2020, while NPP types GFR, LFR, MSR, and SCWR in 2025. Utilization of NPP generation IV said to be optimal if fulfill the goal of NPP generation IV, such as: capable to generate energy sustainability and promote long-term availability of nuclear fuel, minimize nuclear waste and reduce the long term stewardship burden, has an advantage in the field of safety and reliability compared to the previous generation of NPP and VHTR technology have a good prospects in Indonesia. (author)

Interaction of MYC with host cell factor-1 is mediated by the evolutionarily conserved Myc box IV motif.

Science.gov (United States)

Thomas, L R; Foshage, A M; Weissmiller, A M; Popay, T M; Grieb, B C; Qualls, S J; Ng, V; Carboneau, B; Lorey, S; Eischen, C M; Tansey, W P

2016-07-07

The MYC family of oncogenes encodes a set of three related transcription factors that are overexpressed in many human tumors and contribute to the cancer-related deaths of more than 70,000 Americans every year. MYC proteins drive tumorigenesis by interacting with co-factors that enable them to regulate the expression of thousands of genes linked to cell growth, proliferation, metabolism and genome stability. One effective way to identify critical co-factors required for MYC function has been to focus on sequence motifs within MYC that are conserved throughout evolution, on the assumption that their conservation is driven by protein-protein interactions that are vital for MYC activity. In addition to their DNA-binding domains, MYC proteins carry five regions of high sequence conservation known as Myc boxes (Mb). To date, four of the Mb motifs (MbI, MbII, MbIIIa and MbIIIb) have had a molecular function assigned to them, but the precise role of the remaining Mb, MbIV, and the reason for its preservation in vertebrate Myc proteins, is unknown. Here, we show that MbIV is required for the association of MYC with the abundant transcriptional coregulator host cell factor-1 (HCF-1). We show that the invariant core of MbIV resembles the tetrapeptide HCF-binding motif (HBM) found in many HCF-interaction partners, and demonstrate that MYC interacts with HCF-1 in a manner indistinguishable from the prototypical HBM-containing protein VP16. Finally, we show that rationalized point mutations in MYC that disrupt interaction with HCF-1 attenuate the ability of MYC to drive tumorigenesis in mice. Together, these data expose a molecular function for MbIV and indicate that HCF-1 is an important co-factor for MYC.

Collagen type IV at the fetal-maternal interface.

Science.gov (United States)

Oefner, C M; Sharkey, A; Gardner, L; Critchley, H; Oyen, M; Moffett, A

2015-01-01

Extracellular matrix proteins play a crucial role in influencing the invasion of trophoblast cells. However the role of collagens and collagen type IV (col-IV) in particular at the implantation site is not clear. Immunohistochemistry was used to determine the distribution of collagen types I, III, IV and VI in endometrium and decidua during the menstrual cycle and the first trimester of pregnancy. Expression of col-IV alpha chains during the reproductive cycle was determined by qPCR and protein localisation by immunohistochemistry. The structure of col-IV in placenta was examined using transmission electron microscopy. Finally, the expression of col-IV alpha chain NC1 domains and collagen receptors was localised by immunohistochemistry. Col-IV alpha chains were selectively up-regulated during the menstrual cycle and decidualisation. Primary extravillous trophoblast cells express collagen receptors and secrete col-IV in vitro and in vivo, resulting in the increased levels found in decidua basalis compared to decidua parietalis. A novel expression pattern of col-IV in the mesenchyme of placental villi, as a three-dimensional network, was found. NC1 domains of col-IV alpha chains are known to regulate tumour cell migration and the selective expression of these domains in decidua basalis compared to decidua parietalis was determined. Col-IV is expressed as novel forms in the placenta. These findings suggest that col-IV not only represents a structural protein providing tissue integrity but also influences the invasive behaviour of trophoblast cells at the implantation site. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Si IV/O IV Electron Density Diagnostic for the Analysis of IRIS Solar Spectra

Science.gov (United States)

Young, P. R.; Keenan, F. P.; Milligan, R. O.; Peter, H.

2018-04-01

Solar spectra of ultraviolet bursts and flare ribbons from the Interface Region Imaging Spectrograph (IRIS) have suggested high electron densities of > {10}12 cm‑3 at transition region temperatures of 0.1 MK, based on large intensity ratios of Si IV λ1402.77 to O IV λ1401.16. In this work, a rare observation of the weak O IV λ1343.51 line is reported from an X-class flare that peaked at 21:41 UT on 2014 October 24. This line is used to develop a theoretical prediction of the Si IV λ1402.77 to O IV λ1401.16 ratio as a function of density that is recommended to be used in the high-density regime. The method makes use of new pressure-dependent ionization fractions that take account of the suppression of dielectronic recombination at high densities. It is applied to two sequences of flare kernel observations from the October 24 flare. The first shows densities that vary between 3× {10}12 and 3× {10}13 cm‑3 over a seven-minute period, while the second location shows stable density values of around 2× {10}12 cm‑3 over a three-minute period.

Batch and column adsorption behaviors of Se(IV) and Te(IV) on organic and inorganic ion exchangers from HCl solutions

Energy Technology Data Exchange (ETDEWEB)

El-Sweify, Fatma H.; Abdel-Fattah, Alaa El-Din A.; Aly, Shorouk M.; Ghamry, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories Center; El-Sheikh, Ragaa [Zagazig Univ. (Egypt). Chemistry Dept.

2017-07-01

Adsorption behaviors of Se(IV) and Te(IV) on the inorganic ion exchanger ceric tungstate (CeW) was studied under static and dynamic conditions and compared with the adsorption on the organic cation and anion exchangers Dowex-50X8 and AG-2X8, respectively. The radioactive isotopes {sup 75}Se and {sup 123m}Te were used to trace the respective elements. Some parameters affecting the adsorption were investigated under static conditions. In the case of batch technique the adsorption was studied from slightly acidic HCl as well as slightly alkaline media, i.e. at two pH-ranges. Se(IV) and Te(IV) were adsorbed on both the inorganic ion exchanger (CeW) and on AG-2X8, from slightly alkaline solutions. From the similarity of adsorption on both ion exchangers it was clear that (CeW) acts as an anion exchanger. Moreover, the obtained K{sub d}-values for the adsorption on (CeW) were much higher than those for the adsorption on the organic anion exchanger AG-2X8. Se(IV) was not adsorbed on Dowex-50X8 all over the studied pH-range whereas Te(IV) was slightly adsorbed. Loading and elution behaviors of Se(IV) and Te(IV) on columns of AG-2X8 and (CeW) were studied using solutions of HCl of different concentrations. Some good separation alternatives of Se(IV) and Te(IV) under certain conditions were achieved.

Imipenem Treatment Induces Expression of Important Genes and Phenotypes in a Resistant Acinetobacter baumannii Isolate.

Science.gov (United States)

Dhabaan, Ghulam Nasser; AbuBakar, Sazaly; Cerqueira, Gustavo Maia; Al-Haroni, Mohammed; Pang, Sui Ping; Hassan, Hamimah

2015-12-14

Acinetobacter baumannii has emerged as a notorious multidrug-resistant pathogen, and development of novel control measures is of the utmost importance. Understanding the factors that play a role in drug resistance may contribute to the identification of novel therapeutic targets. Pili are essential for A. baumannii adherence to and biofilm formation on abiotic surfaces as well as virulence. In the present study, we found that biofilm formation was significantly induced in an imipenem-resistant (Imp(r)) strain treated with a subinhibitory concentration of antibiotic compared to that in an untreated control and an imipenem-susceptible (Imp(s)) isolate. Using microarray and quantitative PCR analyses, we observed that several genes responsible for the synthesis of type IV pili were significantly upregulated in the Imp(r) but not in the Imp(s) isolate. Notably, this finding is corroborated by an increase in the motility of the Imp(r) strain. Our results suggest that the ability to overproduce colonization factors in response to imipenem treatment confers biological advantage to A. baumannii and may contribute to clinical success. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Spectroscopy study of ceramic pigments based on Ce(IV)-Pr(IV) oxide

International Nuclear Information System (INIS)

Furtado, L.; Toma, H.E.

1991-01-01

The synthesis and spectroscopic properties of a series of cerium(IV)-praseodimium(IV) oxide pigments are reported. The pigments exhibit brick-red colours and are suitable for ceramic applications because of their high temperature stability. Electronic absorption spectra of the pigments suspended in a gel matrix of polyvinyl alcohol-sodium tetradecaborate mixture, consists of broad band with gaussian components at 372 and 472nm. These bands are described to charge -transfer transitions from the occupied oxygen p-orbitals to the empty f levels of the lanthanides. (author)

Liquid-liquid extraction of plutonium(IV) in monoamide - ammonium ionic liquid mixture

International Nuclear Information System (INIS)

Rout, Alok; Venkatesan, K.A.; Antony, M.P.

2016-01-01

Room temperature ionic liquid (RTIL) can be regarded as a sustainable alternative to the conventional molecular diluent, n-dodecane (n-DD), in solvent extraction process. Replacement of volatile organic solvents by RTILs in solvent extraction could lead to inherently safer processes. As far as the cation is concerned, most of the studies reported in literature are focused on imidazolium-based ionic liquids. In contrast to imiadazolium ionic liquids, quarternary ammonium ionic liquids like trioctylmethylammonium chloride (Aliquat 336), trioctylmethylammonium nitrate etc., do not exhibit any cation exchange with the metal ions from aqueous phase during extraction. However, there is no report available in literature that emphasizes the application of trioctylmethylammonium bis(trifluoromethane-sulfonyl)imide ((N_1_8_8_8)(NTf_2)) ionic liquid, for the extraction of Pu(IV). In this paper, we report the advantages of using the ionic liquid, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide ((N_1_8_8_8)(NTf_2)), as diluent, for the extraction of plutonium(IV) in DHOA/(N_1_8_8_8)(NTf_2)

1L Mark-IV Target Design Review

Energy Technology Data Exchange (ETDEWEB)

Koehler, Paul E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-16

This presentation includes General Design Considerations; Current (Mark-III) Lower Tier; Mark-III Upper Tier; Performance Metrics; General Improvements for Material Science; General Improvements for Nuclear Science; Improving FOM for Nuclear Science; General Design Considerations Summary; Design Optimization Studies; Expected Mark-IV Performance: Material Science; Expected Mark-IV Performance: Nuclear Science (Disk); Mark IV Enables Much Wider Range of Nuclear-Science FOM Gains than Mark III; Mark-IV Performance Summary; Rod or Disk? Center or Real FOV?; and Project Cost and Schedule.

Investigating the reasons of variability in Si IV and C IV broad absorption line troughs of quasars

Science.gov (United States)

Stathopoulos, Dimitrios; Lyratzi, Evangelia; Danezis, Emmanuel; Antoniou, Antonios; Tzimeas, Dimitrios

2017-09-01

In this paper we analyze the C IV and Si IV broad absorption troughs of two BALQSOs (J101056.69+355833.3, J114548.38+393746.6) to the individual components they consist of. By analyzing a BAL trough to its components we have the advantage to study the variations of the individual absorbing systems in the line of sight and not just the variations of the whole absorption trough or the variations of selected portions of BAL troughs exhibiting changes. We find that the velocity shifts and FWHMs (Full Width at Half Maximum) of the individual components do not vary between an interval of six years. All variable components show changes in the optical depths at line centers which are manifested as variations in the EW (Equivalent Width) of the components. In both BALQSOs, over corresponding velocities, Si IV has higher incidence of variability than C IV. From our analysis, evidence is in favour of different covering fractions between C IV and Si IV. Finally, although most of our results favour the crossing cloud scenario as the cause of variability, there is also strong piece of evidence indicating changing ionization as the source of variability. Thus, a mixed situation where both physical mechanisms contribute to BAL variability is the most possible scenario.

Topological characterisation and identification of critical domains within glucosyltransferase IV (GtrIV of Shigella flexneri

Directory of Open Access Journals (Sweden)

Nair Anesh

2011-12-01

Full Text Available Abstract Background The three bacteriophage genes gtrA, gtrB and gtr(type are responsible for O-antigen glucosylation in Shigella flexneri. Both gtrA and gtrB have been demonstrated to be highly conserved and interchangeable among serotypes while gtr(type was found to be specific to each serotype, leading to the hypothesis that the Gtr(type proteins are responsible for attaching glucosyl groups to the O-antigen in a site- and serotype- specific manner. Based on the confirmed topologies of GtrI, GtrII and GtrV, such interaction and attachment of the glucosyl groups to the O-antigen has been postulated to occur in the periplasm. Results In this study, the topology of GtrIV was experimentally determined by creating different fusions between GtrIV and a dual-reporter protein, PhoA/LacZ. This study shows that GtrIV consists of 8 transmembrane helices, 2 large periplasmic loops, 2 small cytoplasmic N- and C- terminal ends and a re-entrant loop that occurs between transmembrane helices III and IV. Though this topology differs from that of GtrI, GtrII, GtrV and GtrX, it is very similar to that of GtrIc. Furthermore, both the N-terminal periplasmic and the C-terminal periplasmic loops are important for GtrIV function as shown via a series of loop deletion experiments and the creation of chimeric proteins between GtrIV and its closest structural homologue, GtrIc. Conclusion The current study provides the basis for elucidating the structure and mechanism of action of this important O-antigen modifying glucosyltransferase.

Single-layer group IV-V and group V-IV-III-VI semiconductors: Structural stability, electronic structures, optical properties, and photocatalysis

Science.gov (United States)

Lin, Jia-He; Zhang, Hong; Cheng, Xin-Lu; Miyamoto, Yoshiyuki

2017-07-01

Recently, single-layer group III monochalcogenides have attracted both theoretical and experimental interest at their potential applications in photonic devices, electronic devices, and solar energy conversion. Excited by this, we theoretically design two kinds of highly stable single-layer group IV-V (IV =Si ,Ge , and Sn; V =N and P) and group V-IV-III-VI (IV =Si ,Ge , and Sn; V =N and P; III =Al ,Ga , and In; VI =O and S) compounds with the same structures with single-layer group III monochalcogenides via first-principles simulations. By using accurate hybrid functional and quasiparticle methods, we show the single-layer group IV-V and group V-IV-III-VI are indirect bandgap semiconductors with their bandgaps and band edge positions conforming to the criteria of photocatalysts for water splitting. By applying a biaxial strain on single-layer group IV-V, single-layer group IV nitrides show a potential on mechanical sensors due to their bandgaps showing an almost linear response for strain. Furthermore, our calculations show that both single-layer group IV-V and group V-IV-III-VI have absorption from the visible light region to far-ultraviolet region, especially for single-layer SiN-AlO and SnN-InO, which have strong absorption in the visible light region, resulting in excellent potential for solar energy conversion and visible light photocatalytic water splitting. Our research provides valuable insight for finding more potential functional two-dimensional semiconductors applied in optoelectronics, solar energy conversion, and photocatalytic water splitting.

Charge Transport Phenomena in Peptide Molecular Junctions

International Nuclear Information System (INIS)

Luchini, A.; Petricoin, E.F.; Geho, D.H.; Liotta, L.A.; Long, D.P.; Vaisman, I.I.

2008-01-01

Inelastic electron tunneling spectroscopy (IETS) is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nano electronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable systems for molecular electronics applications, such as biosensors and memory devices.

Multicellular Self-Organization of P. aeruginosa due to Interactions with Secreted Trails.

Science.gov (United States)

Gelimson, Anatolij; Zhao, Kun; Lee, Calvin K; Kranz, W Till; Wong, Gerard C L; Golestanian, Ramin

2016-10-21

Guided movement in response to slowly diffusing polymeric trails provides a unique mechanism for self-organization of some microorganisms. To elucidate how this signaling route leads to microcolony formation, we experimentally probe the trajectory and orientation of Pseudomonas aeruginosa that propel themselves on a surface using type IV pili motility appendages, which preferentially attach to deposited exopolysaccharides. We construct a stochastic model by analyzing single-bacterium trajectories and show that the resulting theoretical prediction for the many-body behavior of the bacteria is in quantitative agreement with our experimental characterization of how cells explore the surface via a power-law strategy.

Supernova Driving. IV. The star-formation rate of molecular clouds

DEFF Research Database (Denmark)

Padoan, Paolo; Haugbølle, Troels; Nordlund, Åke

2017-01-01

We compute the star-formation rate (SFR) in molecular clouds (MCs) that originate ab initio in a new, higher-resolution simulation of supernova-driven turbulence. Because of the large number of well-resolved clouds with self-consistent boundary and initial conditions, we obtain a large range...... of cloud physical parameters with realistic statistical distributions, which is an unprecedented sample of star-forming regions to test SFR models and to interpret observational surveys. We confirm the dependence of the SFR per free-fall time, SFRff, on the virial parameter, αvir, found in previous...... MCs and in clouds near the Galactic center. Although not explicitly modeled by the theory, the scatter is consistent with the physical assumptions of our revised model and may also result in part from a lack of statistical equilibrium of the turbulence, due to the transient nature of MCs....

Trypanosoma cruzi IV causing outbreaks of acute Chagas disease and infections by different haplotypes in the Western Brazilian Amazonia.

Directory of Open Access Journals (Sweden)

Wuelton Marcelo Monteiro

Full Text Available BACKGROUND: Chagas disease is an emergent tropical disease in the Brazilian Amazon Region, with an increasing number of cases in recent decades. In this region, the sylvatic cycle of Trypanosoma cruzi transmission, which constitutes a reservoir of parasites that might be associated with specific molecular, epidemiological and clinical traits, has been little explored. The objective of this work is to genetically characterize stocks of T. cruzi from human cases, triatomines and reservoir mammals in the State of Amazonas, in the Western Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 96 T. cruzi samples from four municipalities in distant locations of the State of Amazonas. Molecular characterization of isolated parasites from cultures in LIT medium or directly from vectors or whole human blood was performed by PCR of the non-transcribed spacer of the mini-exon and of the 24 S alfa ribosomal RNA gene, RFLP and sequencing of the mitochondrial cytochrome c oxidase subunit II (COII gene, and by sequencing of the glucose-phosphate isomerase gene. The T. cruzi parasites from two outbreaks of acute disease were all typed as TcIV. One of the outbreaks was triggered by several haplotypes of the same DTU. TcIV also occurred in isolated cases and in Rhodnius robustus. Incongruence between mitochondrial and nuclear phylogenies is likely to be indicative of historical genetic exchange events resulting in mitochondrial introgression between TcIII and TcIV DTUs from Western Brazilian Amazon. TcI predominated among triatomines and was the unique DTU infecting marsupials. CONCLUSION/SIGNIFICANCE: DTU TcIV, rarely associated with human Chagas disease in other areas of the Amazon basin, is the major strain responsible for the human infections in the Western Brazilian Amazon, occurring in outbreaks as single or mixed infections by different haplotypes.

Reactivity of uranium(IV) bridged chalcogenido complexes UIV–E–UIV (E = S, Se) with elemental sulfur and selenium: synthesis of polychalcogenido-bridged uranium complexes

OpenAIRE

Franke, Sebastian M.; Heinemann, Frank W.; Meyer, Karsten

2014-01-01

We report the syntheses, electronic properties, and molecular structures of a series of polychalcogenido-bridged dinuclear uranium species. These complexes are supported by the sterically encumbering but highly flexible, single N-anchored tris(aryloxide) chelator (AdArO)3N3−. Reaction of an appropriate uranium precursor, either the U(III) starting material, [((AdArO)3N)U(DME)], or the dinuclear mono-chalcogenido-bridged uranium(IV/IV) compounds [{((AdArO)3N)U(DME)}2(μ-E)] (E = S, Se), with el...

Seven-co-ordination in chlorohexakis(trimethylphosphine oxide)- uranium(IV) trichloride: crystal and molecular structure

Energy Technology Data Exchange (ETDEWEB)

Bombieri, G; Forsellini, E [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Brown, D; Whittaker, B

1976-01-01

The structure of the title compound has been determined by single-crystal X-ray diffraction methods from diffractometer data and refined to a final R of 0.023. The compound crystallises in space group R3c with asub(hex) = 18.447(3), csub(hex) = 19.348(3) A, Z = 6. The uranium atom is co-ordinated to one chlorine (U-Cl 2.813 A) and six oxygen atoms (mean U-O 2.26 A); the co-ordination polyhedron can be described as a distorted monocapped trigonal antiprism or as a distorted monocapped octahedron. The anionic chlorines are more than 6.22 A from the uranium atoms. The results are discussed in relation to spectral data for this and related uranium(IV) complexes.

Seven-co-ordination in chlorohexakis(trimethylphosphine oxide)- uranium(IV) trichloride: crystal and molecular structure

International Nuclear Information System (INIS)

Bombieri, G.; Forsellini, E.; Brown, D.; Whittaker, B.

1976-01-01

The structure of the title compound has been determined by single-crystal X-ray diffraction methods from diffractometer data and refined to a final R of 0.023. The compound crystallises in space group R3c with asub(hex) = 18.447(3), csub(hex) = 19.348(3) A, Z = 6. The uranium atom is co-ordinated to one chlorine (U-Cl 2.813 A) and six oxygen atoms (mean U-O 2.26 A); the co-ordination polyhedron can be described as a distorted monocapped trigonal antiprism or as a distorted monocapped octahedron. The anionic chlorines are more than 6.22 A from the uranium atoms. The results are discussed in relation to spectral data for this and related uranium(IV) complexes. (author)

High efficiency diffusion molecular retention tumor targeting.

Directory of Open Access Journals (Sweden)

Yanyan Guo

Full Text Available Here we introduce diffusion molecular retention (DMR tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding and RAD (control probes were synthesized bearing DOTA (for (111 In(3+, a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111In] RGD and [(111In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.. The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide, which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

IV&V Project Assessment Process Validation

Science.gov (United States)

Driskell, Stephen

2012-01-01

The Space Launch System (SLS) will launch NASA's Multi-Purpose Crew Vehicle (MPCV). This launch vehicle will provide American launch capability for human exploration and travelling beyond Earth orbit. SLS is designed to be flexible for crew or cargo missions. The first test flight is scheduled for December 2017. The SLS SRR/SDR provided insight into the project development life cycle. NASA IV&V ran the standard Risk Based Assessment and Portfolio Based Risk Assessment to identify analysis tasking for the SLS program. This presentation examines the SLS System Requirements Review/System Definition Review (SRR/SDR), IV&V findings for IV&V process validation correlation to/from the selected IV&V tasking and capabilities. It also provides a reusable IEEE 1012 scorecard for programmatic completeness across the software development life cycle.

Dissimilatory Fe(III) and Mn(IV) reduction.

Science.gov (United States)

Lovley, D R

1991-06-01

The oxidation of organic matter coupled to the reduction of Fe(III) or Mn(IV) is one of the most important biogeochemical reactions in aquatic sediments, soils, and groundwater. This process, which may have been the first globally significant mechanism for the oxidation of organic matter to carbon dioxide, plays an important role in the oxidation of natural and contaminant organic compounds in a variety of environments and contributes to other phenomena of widespread significance such as the release of metals and nutrients into water supplies, the magnetization of sediments, and the corrosion of metal. Until recently, much of the Fe(III) and Mn(IV) reduction in sedimentary environments was considered to be the result of nonenzymatic processes. However, microorganisms which can effectively couple the oxidation of organic compounds to the reduction of Fe(III) or Mn(IV) have recently been discovered. With Fe(III) or Mn(IV) as the sole electron acceptor, these organisms can completely oxidize fatty acids, hydrogen, or a variety of monoaromatic compounds. This metabolism provides energy to support growth. Sugars and amino acids can be completely oxidized by the cooperative activity of fermentative microorganisms and hydrogen- and fatty-acid-oxidizing Fe(III) and Mn(IV) reducers. This provides a microbial mechanism for the oxidation of the complex assemblage of sedimentary organic matter in Fe(III)- or Mn(IV)-reducing environments. The available evidence indicates that this enzymatic reduction of Fe(III) or Mn(IV) accounts for most of the oxidation of organic matter coupled to reduction of Fe(III) and Mn(IV) in sedimentary environments. Little is known about the diversity and ecology of the microorganisms responsible for Fe(III) and Mn(IV) reduction, and only preliminary studies have been conducted on the physiology and biochemistry of this process.

Pore Structure and Fluoride Ion Adsorption Characteristics of Zr (IV) Surface-Immobilized Resin Prepared Using Polystyrene as a Porogen

Science.gov (United States)

Mizuki, Hidenobu; Ito, Yudai; Harada, Hisashi; Uezu, Kazuya

Zr(IV) surface-immobilized resins for removal of fluoride ion were prepared by surface template polymerization using polystyrene as a porogen. At polymerization, polystyrene was added in order to increase mesopores (2-50 nm) and macropore (>50 nm) with large macropores (around 300 nm) formed with internal aqueous phase of W⁄O emulsion. The pore structure of Zr(IV) surface-immobilized resins was evaluated by measuring specific surface area, pore volume, and pore size distribution with volumetric adsorption measurement instrument and mercury porosimeter. The adsorption isotherms were well fitted by Langmuir equation. The removal of fluoride was also carried out with column method. Zr(IV) surface-immobilized resins, using 10 g⁄L polystyrene in toluene at polymerization, possessed higher volume of not only mesopores and macropores but also large macropores. Furethermore, by adding the polystyrene with smaller molecular size, the pore volume of mesopores, macropores and large macropores was significantly increased, and the fluoride ion adsorption capacity and the column utilization also increased.

Synthesis and characterization of an exact comb polyisoprene with three branches having the middle branch twice the molecular weight of the other two identical external branches

KAUST Repository

Ratkanthwar, Kedar

2013-01-01

An exact comb polyisoprene (PI) with three branches, with the middle branch having twice the molecular weight of the two other identical external branches, was synthesized by using anionic polymerization high vacuum techniques and appropriate chlorosilane chemistry. The synthetic approach involves (a) the selective replacement of the two chlorines of 4-(dichloromethylsilyl) diphenylethylene (DCMSDPE, key molecule) with identical PI chains by titration with PILi, (b) the addition of sec-BuLi to the double bond of DPE followed by the polymerization of isoprene from the newly created anionic site to form a 3-arm living star PI, (c) the selective replacement of the two chlorines of trichloromethylsilane with 3-arm star PI to form an H-shape intermediate, and (d) the replacement of the remaining chlorine of trichloromethylsilane by linear PI chains with double the molecular weight. All intermediate and final products were characterized via size exclusion chromatography, temperature gradient interaction chromatography and 1H-NMR spectroscopy. As expected, due to the inability to control the exact stoichiometry of the linking reactants, the main product (exact comb PI) is contaminated by a few by-products, despite the fact that anionic polymerization is the most efficient way to produce well-defined polymers. © 2013 The Royal Society of Chemistry.

Assembling filamentous phage occlude pIV channels.

Science.gov (United States)

Marciano, D K; Russel, M; Simon, S M

2001-07-31

Filamentous phage f1 is exported from its Escherichia coli host without killing the bacterial cell. Phage-encoded protein pIV, which is required for phage assembly and secretion, forms large highly conductive channels in the outer membrane of E. coli. It has been proposed that the phage are extruded across the bacterial outer membrane through pIV channels. To test this prediction, we developed an in vivo assay by using a mutant pIV that functions in phage export but whose channel opens in the absence of phage extrusion. In E. coli lacking its native maltooligosacharride transporter LamB, this pIV variant allowed oligosaccharide transport across the outer membrane. This entry of oligosaccharide was decreased by phage production and still further decreased by production of phage that cannot be released from the cell surface. Thus, exiting phage block the pIV-dependent entry of oligosaccharide, suggesting that phage occupy the lumen of pIV channels. This study provides the first evidence, to our knowledge, for viral exit through a large aqueous channel.

Non-equilibrium ionization by a periodic electron beam. II. Synthetic Si IV and O IV transition region spectra

Science.gov (United States)

Dzifčáková, Elena; Dudík, Jaroslav

2018-03-01

Context. Transition region (TR) spectra typically show the Si IV 1402.8 Å line to be enhanced by a factor of 5 or more compared to the neighboring O IV 1401.2 Å, contrary to predictions of ionization equilibrium models and the Maxwellian distribution of particle energies. Non-equilibrium effects in TR spectra are therefore expected. Aims: To investigate the combination of non-equilibrium ionization and high-energy particles, we apply the model of the periodic electron beam, represented by a κ-distribution that recurs at periods of several seconds, to plasma at chromospheric temperatures of 104 K. This simple model can approximate a burst of energy release involving accelerated particles. Methods: Instantaneous time-dependent charge states of silicon and oxygen were calculated and used to synthesize the instantaneous and period-averaged spectra of Si IV and O IV. Results: The electron beam drives the plasma out of equilibrium. At electron densities of Ne = 1010 cm-3, the plasma is out of ionization equilibrium at all times in all cases we considered, while for a higher density of Ne = 1011 cm-3, ionization equilibrium can be reached toward the end of each period, depending on the conditions. In turn, the character of the period-averaged synthetic spectra also depends on the properties of the beam. While the case of κ = 2 results in spectra with strong or even dominant O IV, higher values of κ can approximate a range of observed TR spectra. Spectra similar to typically observed spectra, with the Si IV 1402.8 Å line about a factor 5 higher than O IV 1401.2 Å, are obtained for κ = 3. An even higher value of κ = 5 results in spectra that are exclusively dominated by Si IV, with negligible O IV emission. This is a possible interpretation of the TR spectra of UV (Ellerman) bursts, although an interpretation that requires a density that is 1-3 orders of magnitude lower than for equilibrium estimates. Movies associated to Fig. A.1 are available at http://https://www.aanda.org

The effect of amino acid backbone length on molecular packing: crystalline tartrates of glycine, β-alanine, γ-aminobutyric acid (GABA) and DL-α-aminobutyric acid (AABA).

Science.gov (United States)

Losev, Evgeniy; Boldyreva, Elena

2018-02-01

We report a novel 1:1 cocrystal of β-alanine with DL-tartaric acid, C 3 H 7 NO 2 ·C 4 H 6 O 6 , (II), and three new molecular salts of DL-tartaric acid with β-alanine {3-azaniumylpropanoic acid-3-azaniumylpropanoate DL-tartaric acid-DL-tartrate, [H(C 3 H 7 NO 2 ) 2 ] + ·[H(C 4 H 5 O 6 ) 2 ] - , (III)}, γ-aminobutyric acid [3-carboxypropanaminium DL-tartrate, C 4 H 10 NO 2 + ·C 4 H 5 O 6 - , (IV)] and DL-α-aminobutyric acid {DL-2-azaniumylbutanoic acid-DL-2-azaniumylbutanoate DL-tartaric acid-DL-tartrate, [H(C 4 H 9 NO 2 ) 2 ] + ·[H(C 4 H 5 O 6 ) 2 ] - , (V)}. The crystal structures of binary crystals of DL-tartaric acid with glycine, (I), β-alanine, (II) and (III), GABA, (IV), and DL-AABA, (V), have similar molecular packing and crystallographic motifs. The shortest amino acid (i.e. glycine) forms a cocrystal, (I), with DL-tartaric acid, whereas the larger amino acids form molecular salts, viz. (IV) and (V). β-Alanine is the only amino acid capable of forming both a cocrystal [i.e. (II)] and a molecular salt [i.e. (III)] with DL-tartaric acid. The cocrystals of glycine and β-alanine with DL-tartaric acid, i.e. (I) and (II), respectively, contain chains of amino acid zwitterions, similar to the structure of pure glycine. In the structures of the molecular salts of amino acids, the amino acid cations form isolated dimers [of β-alanine in (III), GABA in (IV) and DL-AABA in (V)], which are linked by strong O-H...O hydrogen bonds. Moreover, the three crystal structures comprise different types of dimeric cations, i.e. (A...A) + in (III) and (V), and A + ...A + in (IV). Molecular salts (IV) and (V) are the first examples of molecular salts of GABA and DL-AABA that contain dimers of amino acid cations. The geometry of each investigated amino acid (except DL-AABA) correlates with the melting point of its mixed crystal.

Molecular electronics--resonant transport through single molecules.

Science.gov (United States)

Lörtscher, Emanuel; Riel, Heike

2010-01-01

The mechanically controllable break-junction technique (MCBJ) enables us to investigate charge transport through an individually contacted and addressed molecule in ultra-high vacuum (UHV) environment at variable temperature ranging from room temperature down to 4 K. Using a statistical measurement and analysis approach, we acquire current-voltage (I-V) characteristics during the repeated formation, manipulation, and breaking of a molecular junction. At low temperatures, voltages accessing the first molecular orbitals in resonance can be applied, providing spectroscopic information about the junction's energy landscape, in particular about the molecular level alignment in respect to the Fermi energy of the electrodes. Thereby, we can investigate the non-linear transport properties of various types of functional molecules and explore their potential use as functional building blocks for future nano-electronics. An example will be given by the reversible and controllable switching between two distinct conductive states of a single molecule. As a proof-of-principle for functional molecular devices, a single-molecule memory element will be demonstrated.

Solubility study of Tc(IV) oxides

International Nuclear Information System (INIS)

Liu, D.J.; Fan, X.H.

2005-01-01

The deep geological disposal of the high level radioactive wastes is expected to be a safer disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO 4 - whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 ·nH 2 O. Hence, the mobility of Tc(IV) in reducing groundwater may be limited by the solubility of TcO 2 ·nH 2 O under these conditions. Due to this fact it is important to investigate the solubility of TcO 2 ·nH 2 O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium oxide was prepared by reduction of a technetate solution with Sn 2 + . The solubility of Tc(IV) oxide has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) oxide were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and redistilled water is about (1.49-1.86) x 10 -9 mol/(L·d) under aerobic conditions, but Tc(IV) in simulated groundwater and redistilled water is not oxidized under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) oxide in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The

Organotin(IV Derivatives of 2-Acetylpyridine-N(4-Phenylthiosemicarbazone, HAP4P, and 2-Hydroxyacetophenone-N(4-Phenylthiosemicarbazone, H2DAP4P: Crystal and Molecular Structure of [SnMe2(DAP4P] and [SnBu2(DAP4P

Directory of Open Access Journals (Sweden)

Sousa Gerimário F. de

2001-01-01

Full Text Available The reactions of 2-acetylpyridine-N(4-phenylthiosemicarbazone, HAP4P, and 2-hydroxyacetophenone-N(4-phenylthiosemicarbazone, H2DAP4P, with R4-mSnXm (m = 2, 3; R = Me, nBu, Ph and X = Cl, Br led to the formation of hexa- and penta-coordinated organotin(IV complexes, which were studied by microanalysis, IR, ¹H-NMR and Mössbauer spectroscopies. The molecular structures of [SnMe2(DAP4P] and [Sn nBu2(DAP4P] were determined by single-crystal X-ray diffraction studies. In the compounds [SnClMe2(AP4P] and [SnBrMe2(AP4P], the deprotonated ligand AP4P- is N,N,S-bonded to the Sn(IV atoms, which exhibit strongly distorted octahedral coordination. The structures of [SnMe2(DAP4P] and [Sn nBu2(DAP4P] revealed that the DAP4P2- anion acts as a O,N,S-tridentate ligand. In these cases, the Sn(IV atoms adopt a strongly distorted trigonal bipyramidal configuration where the azomethine N and the two C atoms are on the equatorial plane while the O and the S atoms occupy the axial positions.

The Contribution of IVS to IGGOS

Science.gov (United States)

Nothnagel, A.

2002-05-01

Since its inauguration in 1999, the International VLBI Service for Geodesy and Astrometry has made significant progress in the coordination and utilisation of worldwide VLBI resources. Improving the visibility of the IVS components to a wider public in turn led to a higher motivation of the individuals to contribute to the global effort. Not only the number of IVS components but also their investments in terms of funds and manpower demonstrate the increased awareness of the importance of this joint international endeavour. The different demands of the users but also of the contributors often require the definition of priorities which are only being acceptable due to the existence of a strong umbrella organisation like the IVS. Significant progress has also been made in the area of routine data analysis and combination of results. By now, six IVS Analysis Centers provide the redundancy necessary for a robust combination of the results. The use of ITRF2000 station coordinates as the basis for the IVS combined EOP series is the most recent step towards the generation of a consistent chain from the quasi-inertial frame of radio sources to system Earth.

Charge Transport Processes in Molecular Junctions

Science.gov (United States)

Smith, Christopher Eugene

Molecular electronics (ME) has evolved into a rich area of exploration that combines the fields of chemistry, materials, electronic engineering and computational modeling to explore the physics behind electronic conduction at the molecular level. Through studying charge transport properties of single molecules and nanoscale molecular materials the field has gained the potential to bring about new avenues for the miniaturization of electrical components where quantum phenomena are utilized to achieve solid state molecular device functionality. Molecular junctions are platforms that enable these studies and consist of a single molecule or a small group of molecules directly connected to electrodes. The work presented in this thesis has built upon the current understanding of the mechanisms of charge transport in ordered junctions using self-assembled monolayer (SAM) molecular thin films. Donor and acceptor compounds were synthesized and incorporated into SAMs grown on metal substrates then the transport properties were measured with conducting probe atomic force microscopy (CP-AFM). In addition to experimentally measured current-voltage (I-V) curves, the transport properties were addressed computationally and modeled theoretically. The key objectives of this project were to 1) investigate the impact of molecular structure on hole and electron charge transport, 2) understand the nature of the charge carriers and their structure-transport properties through long (chemically gated to modulate the transport. These results help advance our understanding of transport behavior in semiconducting molecular thin films, and open opportunities to engineer improved electronic functionality into molecular devices.

On the Importance of the Nonequilibrium Ionization of Si IV and O IV and the Line of Sight in Solar Surges

Science.gov (United States)

Nóbrega-Siverio, D.; Moreno-Insertis, F.; Martínez-Sykora, J.

2018-05-01

Surges are ubiquitous cool ejections in the solar atmosphere that often appear associated with transient phenomena like UV bursts or coronal jets. Recent observations from the Interface Region Imaging Spectrograph show that surges, although traditionally related to chromospheric lines, can exhibit enhanced emission in Si IV with brighter spectral profiles than for the average transition region (TR). In this paper, we explain why surges are natural sites to show enhanced emissivity in TR lines. We performed 2.5D radiative-MHD numerical experiments using the Bifrost code including the nonequilibrium (NEQ) ionization of silicon and oxygen. A surge is obtained as a by-product of magnetic flux emergence; the TR enveloping the emerged domain is strongly affected by NEQ effects: assuming statistical equilibrium would produce an absence of Si IV and O IV ions in most of the region. Studying the properties of the surge plasma emitting in the Si IV λ1402.77 and O IV λ1401.16 lines, we find that (a) the timescales for the optically thin losses and heat conduction are very short, leading to departures from statistical equilibrium, and (b) the surge emits in Si IV more and has an emissivity ratio of Si IV to O IV larger than a standard TR. Using synthetic spectra, we conclude the importance of line-of-sight effects: given the involved geometry of the surge, the line of sight can cut the emitting layer at small angles and/or cross it multiple times, causing prominent, spatially intermittent brightenings in both Si IV and O IV.

Synthesis and spectroscopic studies of mono- and dicyclopentadienyl titanium (IV)/zirconium (IV) derivatives with S-alkyl-β-N-(acetylferrocenyl) methylene dithiocarbazates

International Nuclear Information System (INIS)

Srivastava, B.K.; Srivastava, S.K.; Pandey, O.P.; Sengupta, S.K.

1996-01-01

The reactions of dicyclopentadienyl titanium (IV)/zirconium (IV) dichloride and monocyclopentadienyl titanium (IV) trichloride with thio-Schiff bases (LH), derived by the condensation of S-methyl/ethyl/propyl dithiocarbazic acid and acetylferrocene have been carried out under inert atmosphere and anhydrous conditions in different stoichiometric ratios. Complexes of the types Cp 2 M(L)Cl, CpM(L) 2 Cl (M= Ti(IV) or Zr(IV)), CpTi(L)Cl 2 , CpTi(L) 2 Cl are synthesised and characterized by elemental analysis, electrical conductance, magnetic moment and spectral (electronic, infrared, 1 H NMR) data. (author). 12 refs., 1 tab

SAGE IV Pathfinder

Data.gov (United States)

National Aeronautics and Space Administration — Utilizing a unique, new occultation technique involving imaging, the SAGE IV concept will meet or exceed the quality of previous SAGE measurements at a small...

Facile and reversible formation of iron(III)-oxo-cerium(IV) adducts from nonheme oxoiron(IV) complexes and cerium(III)

Energy Technology Data Exchange (ETDEWEB)

Draksharapu, Apparao; Rasheed, Waqas; Klein, Johannes E.M.N.; Que, Lawrence Jr. [Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN (United States)

2017-07-24

Ceric ammonium nitrate (CAN) or Ce{sup IV}(NH{sub 4}){sub 2}(NO{sub 3}){sub 6} is often used in artificial water oxidation and generally considered to be an outer-sphere oxidant. Herein we report the spectroscopic and crystallographic characterization of [(N4Py)Fe{sup III}-O-Ce{sup IV}(OH{sub 2})(NO{sub 3}){sub 4}]{sup +} (3), a complex obtained from the reaction of [(N4Py)Fe{sup II}(NCMe)]{sup 2+} with 2 equiv CAN or [(N4Py)Fe{sup IV}=O]{sup 2+} (2) with Ce{sup III}(NO{sub 3}){sub 3} in MeCN. Surprisingly, the formation of 3 is reversible, the position of the equilibrium being dependent on the MeCN/water ratio of the solvent. These results suggest that the Fe{sup IV} and Ce{sup IV} centers have comparable reduction potentials. Moreover, the equilibrium entails a change in iron spin state, from S=1 Fe{sup IV} in 2 to S=5/2 in 3, which is found to be facile despite the formal spin-forbidden nature of this process. This observation suggests that Fe{sup IV}=O complexes may avail of reaction pathways involving multiple spin states having little or no barrier. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Role of ligand basicity and stereochemistry in the extraction of plutonium(IV) isoxazolonates

International Nuclear Information System (INIS)

Mohapatra, P.K.; Manchanda, V.K.

2003-01-01

The extraction behaviour of plutonium (IV) was investigated from nitric acid and perchloric acid using 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) as well as a mixture of HPBI and tri-n-octyl phosphine oxide (TOPO) in xylene. Studies on the binary extraction system Pu(IV)-HPBI indicated extraction of species of the type Pu(PBI) 4 . In the presence of TOPO, while species of the type Pu(PBI) 3 (ClO 4 ).(TOPO) and Pu(PBI) 4 .TOPO were co-extracted from perchloric acid medium, a mixture of Pu(PBI) 2 (NO 3 ) 2 .2TOPO, Pu(PBI) 3 (NO 3 ).(TOPO) and Pu(PBI) 4 .TOPO were co-extracted from nitric acid medium. In addition to the electronic factors, steric factors were found to play a significant role during the formation of binary/ternary/quaternary complexes. The steric hindrance due to the unusual conformation of the isoxazolone led to lowering of the equilibrium constants for both the binary and ternary extraction systems. Possible steric factor influences are explained with the help of molecular modelling. (orig.)

Collagen type IV at the fetal-maternal interface

OpenAIRE

Oefner, C M; Sharkey, A; Gardner, L; Critchley, H; Oyen, M; Moffett, A

2015-01-01

Introduction Extracellular matrix proteins play a crucial role in influencing the invasion of trophoblast cells. However the role of collagens and collagen type IV (col-IV) in particular at the implantation site is not clear. Methods Immunohistochemistry was used to determine the distribution of collagen types I, III, IV and VI in endometrium and decidua during the menstrual cycle and the first trimester of pregnancy. Expression of col-IV alpha chains during the reproductive cycle ...

Studies on 4-[N-(furfural) amino] antipyrine complexes of thorium (IV) and dioxouranium (VI)

International Nuclear Information System (INIS)

Agarwal, R.K.; Arora, Kishore; Dutt, Prashant

1997-01-01

Thorium (IV) and dioxouranium (VI) complexes of Schiff base 4-[N-(furfural) amino] antipyrine (FFAP) derived from furfural and 4-aminoantipyrine having general composition ThX 4 .nL (X = Cl - , Br - , NCS - or NO 3 - , n = 2; x = I - or ClO 4 - n = 3, L = FFAP) and UO 2 X 2. nL (X Br - , I - , NCS - ,NO 3 - or CH 3 COO - , n = 2; X = ClO 4 - n = 3, L = FFAP) have been synthesized and characterized by molecular weight, conductivity, IR spectral and thermoanalytical studies. (author)

On the stabilization of NbV-solutions by ZrIV and HfIV

International Nuclear Information System (INIS)

Soerensen, E.; Bjerre, A.B.

1987-11-01

Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as Cl- and SO 4 --. This is ascribed to the copolymerisation of Nb v and the hydrolyzed ionic species of Zr IV v and Hf IV by which the colloidal particles are masked as Zr- and Hf-compounds. In HCl the particles are positively charged as opposed to when they are in sulphate solution where the Zr- and Hf- sulphate complexes confer a negative charge. The two cases are considered separately. (author)

Synthesis and evaluation of artificial antigens for astragaloside IV

Directory of Open Access Journals (Sweden)

Sheng-lan Yu

Full Text Available The objective of this study was to produce artificial antigens for astragaloside IV that could be used to prepare antibodies against astragaloside IV screened in Radix astragali (Astragalus membranaceus (Fisch Bunge, Fabaceae and its preparations, using an indirect ELISA. Astragaloside IV was coupled to carrier proteins, bovine serum albumin and ovalbumin using the sodium periodate method and was then evaluated using SDS-PAGE, MALDI-TOF MS and animal immunizations. The coupling ratio of astragaloside IV to bovine serum albumin ratio was determined to be thirteen, and the indirect ELISA demonstrated that three groups of mice immunized with astragaloside IV-bovine serum albumin produced anti-astragaloside IV- bovine serum albumin-specific antibody, with a minimum serum titer of 1:9600. A method for synthesizing highly immunogenic astragaloside IV artificial antigens was successfully developed thus indicating its feasibility in the establishment of a fast immunoassay for astragaloside IV content determination in Radix astragali and its products.

Market opportunities: U.S. - PADD IV

International Nuclear Information System (INIS)

Garner, R.P.

1997-01-01

The current supply and demand balance, the short and long term expectations and marketing opportunities for Canadian crude oil in PADD IV, the Rocky Mountain region in the US, were reviewed. It was suggested that market opportunities in PADD IV are derived from the following four factors: (1) crude oil declines within that area, (2) federal regulations, (3) competitive presence with markets, and (4) population growth. The overall conclusion was that Canadian producers and PADD IV refiners will be looking at an ever-growing relationship based on freight equalized world crude prices. 8 tabs., 5 figs

Report for 2011 from the Bordeaux IVS Analysis Center

Science.gov (United States)

Charlot, Patrick; Bellanger, Antoine; Bourda, Geraldine; Collioud, Arnaud; Baudry, Alain

2012-01-01

This report summarizes the activities of the Bordeaux IVS Analysis Center during the year 2011. The work focused on (i) regular analysis of the IVS-R1 and IVS-R4 sessions with the GINS software package; (ii) systematic VLBI imaging of the RDV sessions and calculation of the corresponding source structure index and compactness values; (iii) imaging of the sources observed during the 2009 International Year of Astronomy IVS observing session; and (iv) continuation of our VLBI observational program to identify optically-bright radio sources suitable for the link with the future Gaia frame. Also of importance is the enhancement of the IVS LiveWeb site which now comprises all IVS sessions back to 2003, allowing one to search past observations for session-specific information (e.g. sources or stations).

Direct Bandgap Group IV Materials

Science.gov (United States)

2016-01-21

AFRL-AFOSR-JP-TR-2017-0049 Direct Bandgap group IV Materials Hung Hsiang Cheng NATIONAL TAIWAN UNIVERSITY Final Report 01/21/2016 DISTRIBUTION A...NAME(S) AND ADDRESS(ES) NATIONAL TAIWAN UNIVERSITY 1 ROOSEVELT RD. SEC. 4 TAIPEI CITY, 10617 TW 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...14. ABSTRACT Direct bandgap group IV materials have been long sought for in both academia and industry for the implementation of photonic devices

Free-format RPG IV

CERN Document Server

Martin, Jim

2013-01-01

This how-to guide offers a concise and thorough introduction to the increased productivity, better readability, and easier program maintenance that comes with the free-format style of programming in RPG IV. Although free-format information is available in IBM manuals, it is not separated from everything else, thereby requiring hours of tedious research to track down the information needed. This book provides everything one needs to know to write RPG IV in the free-format style, and author Jim Martin not only teaches rules and syntax but also explains how this new style of coding has the pot

Preparation of some complexes of Th(IV) and U(IV) with tetradentate Schiff bases. The crystal structure of bis(N,N'-ethylenebis(3-methoxysalicylaldiminato)) thorium(IV) monopyridine

Energy Technology Data Exchange (ETDEWEB)

Hill, R J; Rickard, C E.F.; White, H E [Auckland Univ. (New Zealand). Dept. of Chemistry

1981-01-01

Complexes of Th(IV) and U(IV) with tetradentate Schiff bases derived from substituted salicylaldehydes have been prepared and characterised. The structure of bis(N,N'-ethylenebis(3-methoxysalicylaldiminato)) Th(IV) monopyridine has been determined by X-ray crystallographic methods. The crystals are triclinic, a = 13.468, b = 9.932, c = 16.552 A, ..cap alpha.. = 91.74, ..beta.. = 94.69, ..gamma.. = 93.03/sup 0/, space group P/sub 1//sup -/. The molecules are eight coordinate with a slightly distorted dodecahedral geometry with the imine nitrogen atoms in the dodecahedral A sites. The pyridine molecule is uncoordinated and functions in a space-filling role.

Fabrication of tunnel junction-based molecular electronics and spintronics devices

International Nuclear Information System (INIS)

Tyagi, Pawan

2012-01-01

Tunnel junction-based molecular devices (TJMDs) are highly promising for realizing futuristic electronics and spintronics devices for advanced logic and memory operations. Under this approach, ∼2.5 nm molecular device elements bridge across the ∼2-nm thick insulator of a tunnel junction along the exposed side edge(s). This paper details the efforts and insights for producing a variety of TJMDs by resolving multiple device fabrication and characterization issues. This study specifically discusses (i) compatibility between tunnel junction test bed and molecular solutions, (ii) optimization of the exposed side edge profile and insulator thickness for enhancing the probability of molecular bridging, (iii) effect of fabrication process-induced mechanical stresses, and (iv) minimizing electrical bias-induced instability after the device fabrication. This research will benefit other researchers interested in producing TJMDs efficiently. TJMD approach offers an open platform to test virtually any combination of magnetic and nonmagnetic electrodes, and promising molecules such as single molecular magnets, porphyrin, DNA, and molecular complexes.

78 FR 21491 - DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption...

Science.gov (United States)

2013-04-10

... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662, 02/02-0661] DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that DeltaPoint Capital IV, L.P. and DeltaPoint...

Novel Cryptosporidium bat genotypes III and IV in bats from the USA and Czech Republic.

Science.gov (United States)

Kváč, Martin; Hořická, Anna; Sak, Bohumil; Prediger, Jitka; Salát, Jiří; Širmarová, Jana; Bartonička, Tomáš; Clark, Mark; Chelladurai, Jeba Rose Jennifer Jesudoss; Gillam, Erin; McEvoy, John

2015-10-01

Bats from the families Rhinolophidae (n = 90) and Vespertilionidae (n = 191) in the USA and Czech Republic were screened for the presence of Cryptosporidium by microscopic and molecular analysis of faecal samples collected from rectum of dissected animals and from the ground beneath roosting sites. Cryptosporidium oocysts were not detected in any of the 281 faecal specimens examined using the aniline-carbol-methyl violet staining method. Nested PCR amplification, sequencing and phylogenetic analysis of the small ribosomal subunit rRNA and actin genes were used to identify isolates and infer evolutionary relationships. Cryptosporidium parvum was identified in a western small-footed bat (Myotis ciliolabrum) from the USA and a common pipistrelle bats (Pipistrellus pipistrellus) from the Czech Republic. Two novel genotypes were identified and named Cryptosporidium bat genotype III and IV. Bat genotype III was found in two big brown bats (Eptesicus fuscus) from the USA. Bat genotype IV was detected in two common pipistrelle bats from the Czech Republic.

Design of Carborane Molecular Architectures via Electronic Structure Computations

International Nuclear Information System (INIS)

Oliva, J.M.; Serrano-Andres, L.; Klein, D.J.; Schleyer, P.V.R.; Mich, J.

2009-01-01

Quantum-mechanical electronic structure computations were employed to explore initial steps towards a comprehensive design of poly carborane architectures through assembly of molecular units. Aspects considered were (i) the striking modification of geometrical parameters through substitution, (ii) endohedral carboranes and proposed ejection mechanisms for energy/ion/atom/energy storage/transport, (iii) the excited state character in single and dimeric molecular units, and (iv) higher architectural constructs. A goal of this work is to find optimal architectures where atom/ion/energy/spin transport within carborane superclusters is feasible in order to modernize and improve future photo energy processes.

U(IV) chalcogenolates synthesized via oxidation of uranium metal by dichalcogenides.

Science.gov (United States)

Gaunt, Andrew J; Scott, Brian L; Neu, Mary P

2006-09-04

Treatment of uranium metal with dichalcogenides in the presence of a catalytic amount of iodine in pyridine affords molecular U(IV) chalcogenolates that do not require stabilizing ancillary ligands. Oxidation of U(0) by PhEEPh yields monomeric seven-coordinate U(EPh)4(py)3 (E = S(1), Se(2)). The dimeric eight-coordinate complexes [U(EPh)2(mu2-EPh)2(CH3CN)2]2 (E = S(3), Se(4)) are obtained by crystallization from solutions of 1 and 2 dissolved in acetonitrile. Oxidation of U(0) by pySSpy and crystallization from thf yields nine-coordinate U(Spy)4(thf) (5). Incorporation of elemental selenium into the oxidation of U(0) by PhSeSePh results in the isolation of [U(py)2(SePh)(mu3-Se)(mu2-SePh)]4.4py (6), a tetrameric cluster in which each U(IV) ion is eight-coordinate and the U4Se4 core forms a distorted cube. The compounds were analyzed spectroscopically and the single-crystal X-ray structures of 1 and 3-6 were determined. The isolation of 1-6 represents six new examples of actinide chalcogenolates and allows insight into the nature of "hard" actinide ion-"soft" chalcogen donor interactions.

Disease: H00820 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available of congenital sensorineural hearing loss and pili torti. It is caused by mutations in BCS1L encoding a prot...62000 PMID:10694305 (description) ... AUTHORS ... Selvaag E ... TITLE ... Pili torti and sensorineural hearing los...ITLE ... The Bjornstad syndrome (sensorineural hearing loss and pili torti) disease gene maps to chromosome 2q34-36. ... JOURNAL ... Am J Hum Genet 62:1107-12 (1998) DOI:10.1086/301837 ...

Física molecular de hielos atmosféricos y astrofísicos

OpenAIRE

Maté, Belén

2007-01-01

Presentado en el IV Curso de Iniciación a la Investigación en Estructura de la Materia: Desde las partículas subatómicas hasta los compuestos moleculares (Instituto de Estructura de la Materia, CSIC, 28-30 de Marzo de 2007).

Molecular diodes in optical rectennas

Science.gov (United States)

Duché, David; Palanchoke, Ujwol; Terracciano, Luigi; Dang, Florian-Xuan; Patrone, Lionel; Le Rouzo, Judikael; Balaban, Téodore Silviu; Alfonso, Claude; Charai, Ahmed; Margeat, Olivier; Ackermann, Jorg; Gourgon, Cécile; Simon, Jean-Jacques; Escoubas, Ludovic

2016-09-01

The photo conversion efficiencies of the 1st and 2nd generat ion photovoltaic solar cells are limited by the physical phenomena involved during the photo-conversion processes. An upper limit around 30% has been predicted for a monojunction silicon solar cell. In this work, we study 3rd generation solar cells named rectenna which could direct ly convert visible and infrared light into DC current. The rectenna technology is at odds with the actual photovoltaic technologies, since it is not based on the use of semi-conducting materials. We study a rectenna architecture consist ing of plasmonic nano-antennas associated with rectifying self assembled molecular diodes. We first opt imized the geometry of plasmonic nano-antennas using an FDTD method. The optimal antennas are then realized using a nano-imprint process and associated with self assembled molecular diodes in 11- ferrocenyl-undecanethiol. Finally, The I(V) characterist ics in darkness of the rectennas has been carried out using an STM. The molecular diodes exhibit averaged rect ification ratios of 5.

Dipeptidyl peptidase IV inhibitory activity of protein hydrolyzates ...

African Journals Online (AJOL)

Background: Type 2 diabetes is a chronic metabolic disorder. Recently, dipeptidyl peptidase IV (DPP-IV) inhibitors that protect incretin hormones from being cleaved by DPP-IV have been used as drugs to control glycemia. This study examined the potential hypoglycemic effect of amaranth grain storage protein hydrolyzates ...

Astragaloside IV liposomes ameliorates adriamycin-induced ...

African Journals Online (AJOL)

Methods: The rats were given a single tail intravenous injection of adriamycin (6 mg/kg) within 1 week, and then divided into four groups including normal, model, benazepril and astragaloside IV liposomes group. They were all orally administered dosage of benazepril and astragaloside IV liposomes once daily for 8 weeks.

High cost of stage IV pressure ulcers.

Science.gov (United States)

Brem, Harold; Maggi, Jason; Nierman, David; Rolnitzky, Linda; Bell, David; Rennert, Robert; Golinko, Michael; Yan, Alan; Lyder, Courtney; Vladeck, Bruce

2010-10-01

The aim of this study was to calculate and analyze the cost of treatment for stage IV pressure ulcers. A retrospective chart analysis of patients with stage IV pressure ulcers was conducted. Hospital records and treatment outcomes of these patients were followed up for a maximum of 29 months and analyzed. Costs directly related to the treatment of pressure ulcers and their associated complications were calculated. Nineteen patients with stage IV pressure ulcers (11 hospital-acquired and 8 community-acquired) were identified and their charts were reviewed. The average hospital treatment cost associated with stage IV pressure ulcers and related complications was $129,248 for hospital-acquired ulcers during 1 admission, and $124,327 for community-acquired ulcers over an average of 4 admissions. The costs incurred from stage IV pressure ulcers are much greater than previously estimated. Halting the progression of early stage pressure ulcers has the potential to eradicate enormous pain and suffering, save thousands of lives, and reduce health care expenditures by millions of dollars. Copyright © 2010 Elsevier Inc. All rights reserved.

Temperature and Magnetic Field Driven Modifications in the I-V Features of Gold-DNA-Gold Structure

Directory of Open Access Journals (Sweden)

Nadia Mahmoudi Khatir

2014-10-01

Full Text Available The fabrication of Metal-DNA-Metal (MDM structure-based high sensitivity sensors from DNA micro-and nanoarray strands is a key issue in their development. The tunable semiconducting response of DNA in the presence of external electromagnetic and thermal fields is a gift for molecular electronics. The impact of temperatures (25–55 °C and magnetic fields (0–1200 mT on the current-voltage (I-V features of Au-DNA-Au (GDG structures with an optimum gap of 10 μm is reported. The I-V characteristics acquired in the presence and absence of magnetic fields demonstrated the semiconducting diode nature of DNA in GDG structures with high temperature sensitivity. The saturation current in the absence of magnetic field was found to increase sharply with the increase of temperature up to 45 °C and decrease rapidly thereafter. This increase was attributed to the temperature-assisted conversion of double bonds into single bond in DNA structures. Furthermore, the potential barrier height and Richardson constant for all the structures increased steadily with the increase of external magnetic field irrespective of temperature variations. Our observation on magnetic field and temperature sensitivity of I-V response in GDG sandwiches may contribute towards the development of DNA-based magnetic sensors.

Painlevé IV coherent states

Energy Technology Data Exchange (ETDEWEB)

Bermudez, David, E-mail: david.bermudez@weizmann.ac.il [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel); Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico); Contreras-Astorga, Alonso, E-mail: aloncont@iun.edu [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary IN 46408 (United States); Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico); Fernández C, David J., E-mail: david@fis.cinvestav.mx [Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico)

2014-11-15

A simple way to find solutions of the Painlevé IV equation is by identifying Hamiltonian systems with third-order differential ladder operators. Some of these systems can be obtained by applying supersymmetric quantum mechanics (SUSY QM) to the harmonic oscillator. In this work, we will construct families of coherent states for such subset of SUSY partner Hamiltonians which are connected with the Painlevé IV equation. First, these coherent states are built up as eigenstates of the annihilation operator, then as displaced versions of the extremal states, both involving the related third-order ladder operators, and finally as extremal states which are also displaced but now using the so called linearized ladder operators. To each SUSY partner Hamiltonian corresponds two families of coherent states: one inside the infinite subspace associated with the isospectral part of the spectrum and another one in the finite subspace generated by the states created through the SUSY technique. - Highlights: • We use SUSY QM to obtain Hamiltonians with third-order differential ladder operators. • We show that these systems are related with the Painlevé IV equation. • We apply different definitions of coherent states to these Hamiltonians using the third-order ladder operators and some linearized ones. • We construct families of coherent states for such systems, which we called Painlevé IV coherent states.

Painlevé IV coherent states

International Nuclear Information System (INIS)

Bermudez, David; Contreras-Astorga, Alonso; Fernández C, David J.

2014-01-01

A simple way to find solutions of the Painlevé IV equation is by identifying Hamiltonian systems with third-order differential ladder operators. Some of these systems can be obtained by applying supersymmetric quantum mechanics (SUSY QM) to the harmonic oscillator. In this work, we will construct families of coherent states for such subset of SUSY partner Hamiltonians which are connected with the Painlevé IV equation. First, these coherent states are built up as eigenstates of the annihilation operator, then as displaced versions of the extremal states, both involving the related third-order ladder operators, and finally as extremal states which are also displaced but now using the so called linearized ladder operators. To each SUSY partner Hamiltonian corresponds two families of coherent states: one inside the infinite subspace associated with the isospectral part of the spectrum and another one in the finite subspace generated by the states created through the SUSY technique. - Highlights: • We use SUSY QM to obtain Hamiltonians with third-order differential ladder operators. • We show that these systems are related with the Painlevé IV equation. • We apply different definitions of coherent states to these Hamiltonians using the third-order ladder operators and some linearized ones. • We construct families of coherent states for such systems, which we called Painlevé IV coherent states

Synthesis, characterization and thermal behaviour of cadmium (II) complexes of photosubstituted octacyano-molybdate(IV) and -tungstate(IV) with ethylenediamine

International Nuclear Information System (INIS)

Ali, S.I.; Majid, Kowsar

1998-01-01

Photosubstituted ethylenediamine complexes of M(CN) 8 4- [where M =Mo(IV) or W(IV)] with cadmium (II) chloride have been synthesized and characterized by infrared (IR), thermogravimetric (TG) and differential scanning calorimetry (DSC). Both Mo(IV) and W(IV) show similar stoichiometric as well as thermal decomposition behaviour. The assigned general formula is Cd[M(CN) 3 (OH)(C 2 H 8 N 2 ) 2 ](C 2 H 8 N 2 ) Cl 2 XH 2 O [where M = Mo(IV) for which X = 1(I) and M = W(IV) for which X = 2 (II)]. The presence of CN - , OH - and C 2 H 8 N 2 has been shown by observed characteristic IR peaks. The extra absorption bands appearing in complex (II) are due to librational modes of water which show the formation of hydrogen bonding, which is also supported by TG analysis. The loss of these absorption bands rules out this type of bonding in (I). Both the complexes decompose in three steps up to 650 degC after which there is no change. DSC of the complexes also shows three transitions, two exothermic and one endothermic. On the basis of TG and DSC thermograms, mechanism for the decomposition of each step has been shown. Kinetic parameters like activation energy (E a ), frequency factor (A) and entropy of activation (ΔS) have been calculated using different integral methods. (author)

Nordic Nuclear Materials Forum for Generation IV Reactors

Energy Technology Data Exchange (ETDEWEB)

Anghel, C. (Studsvik Nuclear AB, Nykoeping (Sweden)); Penttilae, S. (Technical Research Centre of Finland, VTT (Finland))

2010-03-15

A network for material issues for Generation IV nuclear power has been initiated within the Nordic countries. The objectives of the Generation IV Nordic Nuclear Materials Forum (NOMAGE4) are to put the basis of a sustainable forum for Gen IV issues, especially focussing on fuels, cladding, structural materials and coolant interaction. Other issues include reactor physics, dynamics and diagnostics, core and fuel design. The present report summarizes the work performed during the year 2009. The efforts made include identification of organisations involved in Gen IV issues in the Nordic countries, update of the forum website, http://www.studsvik.se/GenerationIV, and investigation of capabilities for research within the area of Gen IV. Within the NOMAGE4 project a seminar on Generation IV Nuclear Energy Systems has been organized during 15-16th of October 2009. The aim of the seminar was to provide a forum for exchange of information, discussion on future research needs and networking of experts on Generation IV reactor concepts. As an outcome of the NOMAGE4, a few collaboration project proposals have been prepared/planned in 2009. The network was welcomed by the European Commission and was mentioned as an exemplary network with representatives from industries, universities, power companies and research institutes. NOMAGE4 has been invited to participate to the 'European Energy Research Alliance, EERA, workshop for nuclear structural materials' http://www.eera-set.eu/index.php?index=41 as external observers. Future plans include a new Nordic application for continuation of NOMAGE4 network. (author)

Nordic Nuclear Materials Forum for Generation IV Reactors

International Nuclear Information System (INIS)

Anghel, C.; Penttilae, S.

2010-03-01

A network for material issues for Generation IV nuclear power has been initiated within the Nordic countries. The objectives of the Generation IV Nordic Nuclear Materials Forum (NOMAGE4) are to put the basis of a sustainable forum for Gen IV issues, especially focussing on fuels, cladding, structural materials and coolant interaction. Other issues include reactor physics, dynamics and diagnostics, core and fuel design. The present report summarizes the work performed during the year 2009. The efforts made include identification of organisations involved in Gen IV issues in the Nordic countries, update of the forum website, http://www.studsvik.se/GenerationIV, and investigation of capabilities for research within the area of Gen IV. Within the NOMAGE4 project a seminar on Generation IV Nuclear Energy Systems has been organized during 15-16th of October 2009. The aim of the seminar was to provide a forum for exchange of information, discussion on future research needs and networking of experts on Generation IV reactor concepts. As an outcome of the NOMAGE4, a few collaboration project proposals have been prepared/planned in 2009. The network was welcomed by the European Commission and was mentioned as an exemplary network with representatives from industries, universities, power companies and research institutes. NOMAGE4 has been invited to participate to the 'European Energy Research Alliance, EERA, workshop for nuclear structural materials' http://www.eera-set.eu/index.php?index=41 as external observers. Future plans include a new Nordic application for continuation of NOMAGE4 network. (author)

A COMPARATIVE CLINICAL STUDY BETWEEN IV ESMOLOL AND IV FENTANYL ON ATTENUATION OF HAEMODYNAMIC RESPONSES TO LARYNGOSCOPY AND INTUBATION

Directory of Open Access Journals (Sweden)

Abu Lais Mustaque

2016-04-01

Full Text Available INTRODUCTION Laryngoscopy and intubation is an integral part for providing general anaesthesia to patients undergoing various types of surgery. It also plays an important role in critical care units viz. for providing mechanical ventilation. It is a very essential tool in the hands of anaesthesiologist in maintaining airway. The present study is undertaken to determine and compare the efficacy of single bolus dose of IV esmolol 1 mg/kg and IV fentanyl 2 mcg/kg in attenuating the haemodynamic responses to laryngoscopy and tracheal intubation and to ascertain the effectiveness of esmolol hydrochloride and fentanyl citrate in suppressing sympathetic responses. MATERIAL & METHODS The study was conducted under the Department of Anaesthesiology and Critical Care, Assam Medical College and Hospital, Dibrugarh, during the period July 2013 to June 2014. For this purpose, 150 patients of either sex between 20-50 years of ASA I & II physical status were selected after obtaining informed and written consent and were divided into two groups namely, Group E receiving IV esmolol (1 mg/kg and Group F receiving IV fentanyl (2 mcg/kg. RESULTS Inj. fentanyl 2 mcg/kg IV administered 5 minutes before laryngoscopy and intubation was able to prevent adverse haemodynamic changes better than Inj. esmolol 1 mg/kg IV administered 3 minutes prior to laryngoscopy and intubation during elective surgeries under general anaesthesia. CONCLUSION Hence, from the findings of this study we can conclude that IV bolus dose of fentanyl 2 mcg/kg administered 5 minutes before laryngoscopy and intubation can attenuate the sympathetic response to laryngoscopy and intubation without any side effects of the drug in healthy patients undergoing elective surgeries under general anaesthesia.

Computations of nuclear response functions with MACK-IV

International Nuclear Information System (INIS)

Abdou, M.A.; Gohar, Y.

1978-01-01

The MACK computer program calculates energy pointwise and multigroup nuclear response functions from basic nuclear data in ENDF/B format. The new version of the program, MACK-IV, incorporates major developments and improvements aimed at maximizing the utilization of available nuclear data and ensuring energy conservation in nuclear heating calculations. A new library, MACKLIB-IV, of nuclear response functions was generated in the CTR energy group structure of 171 neutron groups and 36 gamma groups. The library was prepared using MACK-IV and ENDF/B-IV and is suitable for fusion, fusion-fission hybrids, and fission applications

Computations of nuclear response functions with MACK-IV

Energy Technology Data Exchange (ETDEWEB)

Abdou, M A; Gohar, Y

1978-01-01

The MACK computer program calculates energy pointwise and multigroup nuclear response functions from basic nuclear data in ENDF/B format. The new version of the program, MACK-IV, incorporates major developments and improvements aimed at maximizing the utilization of available nuclear data and ensuring energy conservation in nuclear heating calculations. A new library, MACKLIB-IV, of nuclear response functions was generated in the CTR energy group structure of 171 neutron groups and 36 gamma groups. The library was prepared using MACK-IV and ENDF/B-IV and is suitable for fusion, fusion-fission hybrids, and fission applications.

Surface association and the MreB cytoskeleton regulate pilus production, localization and function in Pseudomonas aeruginosa.

Science.gov (United States)

Cowles, Kimberly N; Gitai, Zemer

2010-06-01

Spatial organization of bacterial proteins influences many cellular processes, including division, chromosome segregation and motility. Virulence-associated proteins also localize to specific destinations within bacterial cells. However, the functions and mechanisms of virulence factor localization remain largely unknown. In this work, we demonstrate that polar assembly of the Pseudomonas aeruginosa PAO1 type IV pilus is regulated by surface association in a manner that affects gene transcription, protein levels and protein localization. We also uncover one mechanism for this regulation that acts through the actin homologue MreB. Inactivation of MreB leads to mislocalization of the pilus retraction ATPase PilT, mislocalization of the pili themselves and a reduction in motility. Furthermore, the role of MreB in polar localization of PilT is modulated by surface association, corroborating our results that environmental factors influence the regulation of pilus production. Specifically, MreB mediates both the initiation and maintenance of PilT localization when cells are grown in suspension but only affects the initiation of localization when cells are grown on a surface. Together, these results suggest that the bacterial cytoskeleton provides a mechanism for the polar localization of P. aeruginosa pili and demonstrate that protein localization may represent an important aspect of virulence factor regulation in bacterial pathogens.

Redox behavior of Ce(IV)/Ce(III) in the presence of nitrilotriacetic acid: a surrogate study for An(IV)/An(III) redox behavior

International Nuclear Information System (INIS)

Suzuki, Y.; Nankawa, T.; Ohnuki, T.; Francis, A.J.

2010-01-01

Using cyclic voltammetry, we investigated the redox behavior of Ce(IV)/Ce(III), which is a surrogate for An(IV)/An(III) (An = actinides), in a solution of nitrilotriacetic acid (NTA) at 25 C. The cyclic voltammogram of Ce in a 0.1 M NTA solution at pH 6 showed a reversible one-electron redox reaction for Ce(IV)/Ce(III) at 0.51 V vs. Ag/AgCl. This redox potential was much lower than that obtained in 1 M nitric acid, indicating that Ce(IV) was preferentially stabilized by complexation with NTA. The redox potential in the NTA solution was independent of the Ce concentration from 2 to 20 mM, NTA concentration from 5 to 200 mM and pH between 3 and 7. These results indicated that no polymerization and no additional coordination of NTA and OH to the Ce(III)-NTA complex took place during the redox reaction. As the speciation calculation of Ce(III) in the NTA solution showed that the predominant species was Ce III (nta) 2 3 (H 3 nta = NTA), the redox reaction of the Ce-NTA complex was expressed by the following: Ce IV (nta) 2 2- + e - ↔ Ce III (nta) 2 3 . The logarithm of the stability constant of Ce IV (nta) 2 2- was calculated to be 38.6 ± 0.8 for I = 0 from the redox potential shift of Ce(IV)/Ce(III) in the NTA solution. The value was in good accordance with the stability constant of the Np IV (nta) 2 2- complex, demonstrating that the aqueous coordination chemistry of Ce(IV) with NTA is quite similar to that of An(IV). These results strongly suggest that a negative shift of the Pu(IV)/Pu(III) redox potential in the NTA solution should make Pu(IV) more stable than Pu(III) even in a reducing environment. (orig.)

Synthesis, spectroscopic properties and biological activity of new mono organotin(IV complexes with 5-bromo-2-hydroxybenzaldehyde-4,4-dimethylthiosemicarbazone

Directory of Open Access Journals (Sweden)

Rosenani A. Haque

2015-12-01

Full Text Available The organotin(IV complexes [RSn(L] (where R = Me (2, R = n-Bu (3, R = Ph (4; H2L (1 = 5-bromo-2-hydroxybenzaldehyde-4,4-dimethylthiosemicarbazone have been synthesized by the reaction of organotin(IV chloride(s with H2L (1. All the compounds have been characterized by CHN analyses, UV–vis, FT-IR, 1H, 13C and 119Sn NMR spectral studies. The molecular structure of H2L (1 has been confirmed by X-ray crystallography. The infrared spectrum gives confirmation for the compound (H2L in the thione form, which is supported with the observed bond lengths from the crystal structure. Spectral studies revealed that the dinegative tridentate ligand is bonded to the tin(IV atom via phenolic-O, azomethine-N and thiolate-S atoms. 119Sn NMR data in DMSO-d6 suggested penta-coordinated Sn(IV atom in solutions for all complexes (2–4. The compound, H2L (1 crystallizes into a monoclinic lattice with the space group P21/c, Z = 4, V = 1,191.75(8Å3. The compounds were also tested for their antiproliferative activity against human colon cancer cell line (HCT 116 and displayed strong cytotoxic activities.

Safety assessment for Generation IV nuclear systems

International Nuclear Information System (INIS)

Leahy, T.J.

2012-01-01

The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Recent RSWG work has focused on the definition of an integrated safety assessment methodology (ISAM) for evaluating the safety of Generation IV systems. ISAM is an integrated 'tool-kit' consisting of 5 analytical techniques that are available and matched to appropriate stages of Generation IV system concept development: 1) qualitative safety features review - QSR, 2) phenomena identification and ranking table - PIRT, 3) objective provision tree - OPT, 4) deterministic and phenomenological analyses - DPA, and 5) probabilistic safety analysis - PSA. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time

The high molecular weight dipeptidyl peptidase IV Pol d 3 is a major allergen of Polistes dominula venom.

Science.gov (United States)

Schiener, Maximilian; Hilger, Christiane; Eberlein, Bernadette; Pascal, Mariona; Kuehn, Annette; Revets, Dominique; Planchon, Sébastien; Pietsch, Gunilla; Serrano, Pilar; Moreno-Aguilar, Carmen; de la Roca, Federico; Biedermann, Tilo; Darsow, Ulf; Schmidt-Weber, Carsten B; Ollert, Markus; Blank, Simon

2018-01-22

Hymenoptera venom allergy can cause severe anaphylaxis in untreated patients. Polistes dominula is an important elicitor of venom allergy in Southern Europe as well as in the United States. Due to its increased spreading to more moderate climate zones, Polistes venom allergy is likely to gain importance also in these areas. So far, only few allergens of Polistes dominula venom were identified as basis for component-resolved diagnostics. Therefore, this study aimed to broaden the available panel of important Polistes venom allergens. The 100 kDa allergen Pol d 3 was identified by mass spectrometry and found to be a dipeptidyl peptidase IV. Recombinantly produced Pol d 3 exhibited sIgE-reactivity with approximately 66% of Polistes venom-sensitized patients. Moreover, its clinical relevance was supported by the potent activation of basophils from allergic patients. Cross-reactivity with the dipeptidyl peptidases IV from honeybee and yellow jacket venom suggests the presence of exclusive as well as conserved IgE epitopes. The obtained data suggest a pivotal role of Pol d 3 as sensitizing component of Polistes venom, thus supporting its status as a major allergen of clinical relevance. Therefore, Pol d 3 might become a key element for proper diagnosis of Polistes venom allergy.

Diffuse reticuloendothelial system involvement in type IV glycogen storage disease with a novel GBE1 mutation: a case report and review.

Science.gov (United States)

Magoulas, Pilar L; El-Hattab, Ayman W; Roy, Angshumoy; Bali, Deeksha S; Finegold, Milton J; Craigen, William J

2012-06-01

Glycogen storage disease type IV is a rare autosomal recessive disorder of glycogen metabolism caused by mutations in the GBE1 gene that encodes the 1,4-alpha-glucan-branching enzyme 1. Its clinical presentation is variable, with the most common form presenting in early childhood with primary hepatic involvement. Histologic manifestations in glycogen storage disease type IV typically consist of intracytoplasmic non-membrane-bound inclusions containing abnormally branched glycogen (polyglucosan bodies) within hepatocytes and myocytes. We report a female infant with classic hepatic form of glycogen storage disease type IV who demonstrated diffuse reticuloendothelial system involvement with the spleen, bone marrow, and lymph nodes infiltrated by foamy histiocytes with intracytoplasmic polyglucosan deposits. Sequence analysis of the GBE1 gene revealed compound heterozygosity for a previously described frameshift mutation (c.1239delT) and a novel missense mutation (c.1279G>A) that is predicted to alter a conserved glycine residue. GBE enzyme analysis revealed no detectable activity. A review of the literature for glycogen storage disease type IV patients with characterized molecular defects and deficient enzyme activity reveals most GBE1 mutations to be missense mutations clustering in the catalytic enzyme domain. Individuals with the classic hepatic form of glycogen storage disease type IV tend to be compound heterozygotes for null and missense mutations. Although the extensive reticuloendothelial system involvement that was observed in our patient is not typical of glycogen storage disease type IV, it may be associated with severe enzymatic deficiency and a poor outcome. Copyright © 2012 Elsevier Inc. All rights reserved.

U(IV) fluorescence spectroscopy. A new speciation tool

Energy Technology Data Exchange (ETDEWEB)

Lehmann, Susanne; Brendler, Vinzenz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

2017-06-01

We combined absorption and fluorescence spectroscopy to study the speciation of U(IV) in solution in concentrations down to 10{sup -6} M uranium. With our time-resolved laser-induced fluorescence setup we could determine the fluorescence decay time of U(IV) in perchloric as well as in chloric acid with 2.6 ± 0.3 ns at room temperature and 148.4 ± 6.5 ns at liquid nitrogen temperature. For the U(IV) sulfate system, we observed a bathochromic shift and a peak shape modification in the fluorescence spectra with increasing sulfate concentration in solution. Thus, the potential of U(IV) fluorescence for speciation analysis could be proven.

A 48 kDa collagen-binding phosphoprotein isolated from bovine aortic endothelial cells interacts with the collagenous domain, but not the globular domain, of collagen type IV.

OpenAIRE

Yannariello-Brown, J; Madri, J A

1990-01-01

We have identified collagen-binding proteins in detergent extracts of metabolically labelled bovine aortic endothelial cells (BAEC) by collagen type IV-Sepharose affinity chromatography. The major collagen type IV-binding protein identified by SDS/PAGE had a molecular mass of 48 kDa, which we term the 'collagen-binding 48 kDa protein' (CB48). The pI of CB48 was 8.0-8.3 in a two-dimensional gel system, running non-equilibrium pH gel electrophoresis in the first dimension and SDS/PAGE in the se...

A sputnik IV saga

Science.gov (United States)

Lundquist, Charles A.

2009-12-01

The Sputnik IV launch occurred on May 15, 1960. On May 19, an attempt to deorbit a 'space cabin' failed and the cabin went into a higher orbit. The orbit of the cabin was monitored and Moonwatch volunteer satellite tracking teams were alerted to watch for the vehicle demise. On September 5, 1962, several team members from Milwaukee, Wisconsin made observations starting at 4:49 a.m. of a fireball following the predicted orbit of Sputnik IV. Requests went out to report any objects found under the fireball path. An early morning police patrol in Manitowoc had noticed a metal object on a street and had moved it to the curb. Later the officers recovered the object and had it dropped off at the Milwaukee Journal. The Moonwarch team got the object and reported the situation to Moonwatch Headquarters at the Smithsonian Astrophysical Observatory. A team member flew to Cambridge with the object. It was a solid, 9.49 kg piece of steel with a slag-like layer attached to it. Subsequent analyses showed that it contained radioactive nuclei produced by cosmic ray exposure in space. The scientists at the Observatory quickly recognized that measurements of its induced radioactivity could serve as a calibration for similar measurements of recently fallen nickel-iron meteorites. Concurrently, the Observatory directorate informed government agencies that a fragment from Sputnik IV had been recovered. Coincidently, a debate in the UN Committee on Peaceful Uses of Outer Space involved the issue of liability for damage caused by falling satellite fragments. On September 12, the Observatory delivered the bulk of the fragment to the US Delegation to the UN. Two days later, the fragment was used by US Ambassador Francis Plimpton as an exhibit that the time had come to agree on liability for damage from satellite debris. He offered the Sputnik IV fragment to USSR Ambassador P.D. Morozov, who refused the offer. On October 23, Drs. Alla Massevitch and E.K. Federov of the USSR visited the

Patients with a new variant of endemic pemphigus foliaceus have autoantibodies against arrector pili muscle, colocalizing with MYZAP, p0071, desmoplakins 1 and 2 and ARVCF.

Science.gov (United States)

Abreu-Velez, A M; Valencia-Yepes, C A; Upegui-Zapata, Y A; Upegui-Quiceno, E; Mesa-Herrera, N R; Velazquez-Velez, J E; Howard, M S

2017-12-01

We identified a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America, which we term El Bagre-EPF, and observed reactivity to arrector pili muscle (APM), thus we tested for autoimmunity to APM. We took skin biopsies from 30 patients with El Bagre-EPF and 30 healthy controls (HCs) matched by age, sex and occupation, who were all from the endemic area, and tested these using direct immunofluorescence (DIF), confocal microscopy, immunohistochemistry and immunoblotting (IB). Of the 30 patients with El Bagre-EPF, 27 had autoantibodies to APM that colocalized with commercial antibodies to myocardium-enriched zonula occludens-1-associated protein (MYZAP), desmoplakin (DP)1 and DP2, plakophilin 4, and Armadillo repeat gene deleted in velo-cardio-facial syndrome (ARVCF) (P EPF have autoantibodies to APM, colocalizing with the antibodies MYZAP, ARVCF, p0071, DP1 and DP2, suggesting that these molecules are El Bagre-EPF antigens. Further, all of these antigens represent components of cell junctions, indicating that the immune response is directed, at least partially, against cell junctions. The immune response in patients affected by El Bagre-EPF is polyclonal, and it includes B and T lymphocytes, mast cells, IgG, IgA, IgM, IgD, IgE, fibrinogen, albumin, complement/C1q, C3c and C4. © 2017 British Association of Dermatologists.

Determination of uranium (IV) by flow voltammetry

International Nuclear Information System (INIS)

Ding Anqing

1987-01-01

According to the quantitative reaction of U(IV) and Fe(III) in H 2 SO 4 as well as the relation between current and concentration of substance detected, U(IV) has been determined indirectly by measurement of the electrolysis current of residual Fe(III). The columniform electrode used is made of glass carbon particles. At the range of U(IV) from a few micrograms to 40 μg, the linear relation is excellent. The relative standard deviation is within ±4%. The interference of Fe(II), Ti(IV) and U(VI) is negligible but of Ti(III) is serious. This method has been successfully applied in the determination of actual samples (both out line and on line). Main advantages of this procedure are rapid, simple, small amount of sample (only at microgram level) and easy to realize automation, able to use for on line or process analysis

Testing and economical evaluation of U(IV) in Purex

International Nuclear Information System (INIS)

Hoisington, J.E.; Hsu, T.C.

1983-01-01

The use of uranous nitrate, U(IV), as a plutonium reductant in the Purex solvent extraction process could significantly reduce the waste generation at the Savannah River Plant. The current reductant is a ferrous sulfamate (FS)/hydroxylamine nitrate (HAN) mixture. The iron and sulfate in the FS are major contributors to waste generation. The U(IV) reductant oxidizes to U(VI) producing no waste. The Savannah River Laboratory has developed an efficient electrochemical cell for U(IV) production and has demonstrated the effectiveness of U(IV) as a plutonium reductant. Plant tests and economic analyses are currently being conducted to determine the cost effectiveness of U(IV) implementation. The results of recent studies are presented

Are stage IV vestibular schwannomas preoperatively different from other stages?

Science.gov (United States)

Tringali, Stéphane; Dubreuil, Christian; Zaouche, Sandra; Ferber-Viart, Chantal

2008-01-01

The aim of this study was to focus on the clinical and paraclinical symptoms of patients suffering from Stage IV vestibular schwannomas (VSs). In this prospective study, we included 734 patients who have VS and candidates for operation. Patients were classified as having Stage I, II, III, or IV tumors according to Tos criteria as evaluated by magnetic resonance imaging. PREOPERATIVE CLINICAL EVALUATION: We recorded the occurrence of complaints (%) and duration (yr) of hearing loss, tinnitus, and balance disorder. Preoperative paraclinical evaluation included pure-tone (PTA) and speech audiometry, auditory brainstem response (ABR) patterns, and vestibular deficit at videonystamography (VNG). Continuous variables were compared between Stage IV and other stages using analysis of variance. Qualitative variables expressed as a percentage of presence were compared between Stage IV and other stages using percentage comparison. Quantitative Parameters. Patients with Stage IV VS were significantly younger as compared with patients with other stages. Stage IV hearing loss was greater compared with other stages at 250 and 500 Hz but smaller at 2,000 and 8,000 Hz. We found no difference in the loss of PTA between Stage IV and the other stages. Speech discriminancy score was smaller in Stage IV. The durations of hearing loss, tinnitus, and balance disorders were similar whatever the tumor stage. Auditory brainstem response patterns showed no difference in Wave III latency between Stage IV VS and other stages, whereas Wave V latency and V-I interval were higher in Stage IV. Both ABR threshold and VNG caloric deficit were higher in Stage IV VS compared with other stages. Qualitative Parameters. The percentage of patients with Stage IV was lower than that with Stages II and III. The percentage of men and women was similar in all stages. The occurrence of hearing loss was similar in all stages, whereas that of tinnitus was lower in Stage IV compared with Stages I and II. In

COBRA-IV wire wrap data comparisons

International Nuclear Information System (INIS)

Donovan, T.E.; George, T.L.; Wheeler, C.L.

1979-02-01

Thermal hydraulic analyses of hexagonally packed wire-wrapped fuel assemblies are complicated by the induced crossflow between adjacent subchannels. The COBRA-IV computer code simultaneously solves the hydrodynamics and thermodynamics of fuel assemblies. The modifications and the results are presented which are predicted by the COBRA-IV calculation. Comparisons are made with data measured in five experimental models of a wire-wrapped fuel assembly

GSK3 inactivation is involved in mitochondrial complex IV defect in transforming growth factor (TGF) {beta}1-induced senescence

Energy Technology Data Exchange (ETDEWEB)

Byun, Hae-Ok; Jung, Hyun-Jung; Seo, Yong-Hak; Lee, Young-Kyoung [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon 443-721 (Korea, Republic of); Department of Molecular Science and Technology, The Graduate School, Ajou University, Suwon 443-721 (Korea, Republic of); Hwang, Sung-Chul [Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon 443-721 (Korea, Republic of); Seong Hwang, Eun [Department of Life Science, University of Seoul, Seoul 130-743 (Korea, Republic of); Yoon, Gyesoon, E-mail: ypeace@ajou.ac.kr [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon 443-721 (Korea, Republic of); Department of Molecular Science and Technology, The Graduate School, Ajou University, Suwon 443-721 (Korea, Republic of)

2012-09-10

Transforming growth factor {beta}1 (TGF {beta}1) induces Mv1Lu cell senescence by persistently producing mitochondrial reactive oxygen species (ROS) through decreased complex IV activity. Here, we investigated the molecular mechanism underlying the effect of TGF {beta}1 on mitochondrial complex IV activity. TGF {beta}1 progressively phosphorylated the negative regulatory sites of both glycogen synthase kinase 3 (GSK3) {alpha} and {beta}, corresponding well to the intracellular ROS generation profile. Pre-treatment of N-acetyl cysteine, an antioxidant, did not alter this GSK3 phosphorylation (inactivation), whereas pharmacological inhibition of GSK3 by SB415286 significantly increased mitochondrial ROS, implying that GSK3 phosphorylation is an upstream event of the ROS generation. GSK3 inhibition by SB415286 decreased complex IV activity and cellular O{sub 2} consumption rate and eventually induced senescence of Mv1Lu cell. Similar results were obtained with siRNA-mediated knockdown of GSK3. Moreover, we found that GSK3 not only exists in cytosol but also in mitochondria of Mv1Lu cell and the mitochondrial GSK3 binds complex IV subunit 6b which has no electron carrier and is topologically located in the mitochondrial intermembrane space. Involvement of subunit 6b in controlling complex IV activity and overall respiration rate was proved with siRNA-mediated knockdown of subunit 6b. Finally, TGF {beta}1 treatment decreased the binding of the subunit 6b to GSK3 and subunit 6b phosphorylation. Taken together, our results suggest that GSK3 inactivation is importantly involved in TGF {beta}1-induced complex IV defects through decreasing phosphorylation of the subunit 6b, thereby contributing to senescence-associated mitochondrial ROS generation.

Morphological and molecular diagnostics of Phytoseiulus persimilis and Phytoseiulus macropilis (Acari: Phytoseiidae).

Science.gov (United States)

Okassa, Mireille; Tixier, Marie-Stéphane; Kreiter, Serge

2010-11-01

This study focuses on the diagnostics of two natural enemy species, belonging to the genus Phytoseiulus in the family Phytoseiidae (sub-family Amblyseiinae): P. macropilis and P. persimilis. These two species are of primary importance in biological control all over the world. However, they are morphologically very similar and specific diagnostics is difficult. This study utilizes mitochondrial molecular markers (12S rRNA and Cytb mtDNA) to differentiate these two species. Morphological analyses showed significant differences between P. persimilis and P. macropilis for 17 morphological characters of the 32 considered. However, despite these significant differences, the ranges of all characters overlap. Only the serration of the macroseta on the basitarsus (StIV) allows the differentiation between P. persimilis and P. macropilis. Despite these small morphological differences, molecular results, for both mitochondrial DNA fragments considered (rRNA and Cytb mtDNA), showed a clear delineation between the specimens of P. macropilis and P. persimilis. This study emphasizes (i) that only one morphological character (serration of the seta StIV) clearly separates these two species, and (ii) the usefulness of an automatical molecular and simple diagnostic tool for accurate differentiation of the two species and ensure the morphological diagnostics. Further studies are proposed, including more DNA sequences especially for P. macropilis.

Determination of the solubility of Np(IV), Pu(III) - (VI),Am(III) - (VI), and Te(IV), (V) hydroxo compounds in 0.5 - 14 M NaOH solutions

Energy Technology Data Exchange (ETDEWEB)

Delegard, C.H.

1996-09-24

The solubilities of Am(III), Np(IV), Pu(IV), Tc(IV), Np(V), Pu(V), Am(V), and Tc(V) hydroxo compounds were studied in 0.5 to 14 M NaOH solutions at 25{+-}2 {degrees}C. The effects of fluoride, phosphate, carbonate, oxalate, and some other organic complexing agents on the solubilities of Np(IV), Pu(IV), and TC(IV) hydroxides were investigated at 1.0 and 4.0 M NAOH. Some predictions were made on the dissolved (I.V) and (V) species present in alkali solutions.

Ehlers-Danlos syndrome type IV

Directory of Open Access Journals (Sweden)

Germain Dominique P

2007-07-01

Full Text Available Abstract Ehlers-Danlos syndrome type IV, the vascular type of Ehlers-Danlos syndromes (EDS, is an inherited connective tissue disorder defined by characteristic facial features (acrogeria in most patients, translucent skin with highly visible subcutaneous vessels on the trunk and lower back, easy bruising, and severe arterial, digestive and uterine complications, which are rarely, if at all, observed in the other forms of EDS. The estimated prevalence for all EDS varies between 1/10,000 and 1/25,000, EDS type IV representing approximately 5 to 10% of cases. The vascular complications may affect all anatomical areas, with a tendency toward arteries of large and medium diameter. Dissections of the vertebral arteries and the carotids in their extra- and intra-cranial segments (carotid-cavernous fistulae are typical. There is a high risk of recurrent colonic perforations. Pregnancy increases the likelihood of a uterine or vascular rupture. EDS type IV is inherited as an autosomal dominant trait that is caused by mutations in the COL3A1 gene coding for type III procollagen. Diagnosis is based on clinical signs, non-invasive imaging, and the identification of a mutation of the COL3A1 gene. In childhood, coagulation disorders and Silverman's syndrome are the main differential diagnoses; in adulthood, the differential diagnosis includes other Ehlers-Danlos syndromes, Marfan syndrome and Loeys-Dietz syndrome. Prenatal diagnosis can be considered in families where the mutation is known. Choriocentesis or amniocentesis, however, may entail risk for the pregnant woman. In the absence of specific treatment for EDS type IV, medical intervention should be focused on symptomatic treatment and prophylactic measures. Arterial, digestive or uterine complications require immediate hospitalisation, observation in an intensive care unit. Invasive imaging techniques are contraindicated. Conservative approach is usually recommended when caring for a vascular

Ehlers-Danlos syndrome type IV

Science.gov (United States)

Germain, Dominique P

2007-01-01

Ehlers-Danlos syndrome type IV, the vascular type of Ehlers-Danlos syndromes (EDS), is an inherited connective tissue disorder defined by characteristic facial features (acrogeria) in most patients, translucent skin with highly visible subcutaneous vessels on the trunk and lower back, easy bruising, and severe arterial, digestive and uterine complications, which are rarely, if at all, observed in the other forms of EDS. The estimated prevalence for all EDS varies between 1/10,000 and 1/25,000, EDS type IV representing approximately 5 to 10% of cases. The vascular complications may affect all anatomical areas, with a tendency toward arteries of large and medium diameter. Dissections of the vertebral arteries and the carotids in their extra- and intra-cranial segments (carotid-cavernous fistulae) are typical. There is a high risk of recurrent colonic perforations. Pregnancy increases the likelihood of a uterine or vascular rupture. EDS type IV is inherited as an autosomal dominant trait that is caused by mutations in the COL3A1 gene coding for type III procollagen. Diagnosis is based on clinical signs, non-invasive imaging, and the identification of a mutation of the COL3A1 gene. In childhood, coagulation disorders and Silverman's syndrome are the main differential diagnoses; in adulthood, the differential diagnosis includes other Ehlers-Danlos syndromes, Marfan syndrome and Loeys-Dietz syndrome. Prenatal diagnosis can be considered in families where the mutation is known. Choriocentesis or amniocentesis, however, may entail risk for the pregnant woman. In the absence of specific treatment for EDS type IV, medical intervention should be focused on symptomatic treatment and prophylactic measures. Arterial, digestive or uterine complications require immediate hospitalisation, observation in an intensive care unit. Invasive imaging techniques are contraindicated. Conservative approach is usually recommended when caring for a vascular complication in a patient suffering

Gen IV Materials Handbook Implementation Plan

International Nuclear Information System (INIS)

Rittenhouse, P.; Ren, W.

2005-01-01

A Gen IV Materials Handbook is being developed to provide an authoritative single source of highly qualified structural materials information and materials properties data for use in design and analyses of all Generation IV Reactor Systems. The Handbook will be responsive to the needs expressed by all of the principal government, national laboratory, and private company stakeholders of Gen IV Reactor Systems. The Gen IV Materials Handbook Implementation Plan provided here addresses the purpose, rationale, attributes, and benefits of the Handbook and will detail its content, format, quality assurance, applicability, and access. Structural materials, both metallic and ceramic, for all Gen IV reactor types currently supported by the Department of Energy (DOE) will be included in the Gen IV Materials Handbook. However, initial emphasis will be on materials for the Very High Temperature Reactor (VHTR). Descriptive information (e.g., chemical composition and applicable technical specifications and codes) will be provided for each material along with an extensive presentation of mechanical and physical property data including consideration of temperature, irradiation, environment, etc. effects on properties. Access to the Gen IV Materials Handbook will be internet-based with appropriate levels of control. Information and data in the Handbook will be configured to allow search by material classes, specific materials, specific information or property class, specific property, data parameters, and individual data points identified with materials parameters, test conditions, and data source. Details on all of these as well as proposed applicability and consideration of data quality classes are provided in the Implementation Plan. Website development for the Handbook is divided into six phases including (1) detailed product analysis and specification, (2) simulation and design, (3) implementation and testing, (4) product release, (5) project/product evaluation, and (6) product

Independent Examination of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV): What Does the WAIS-IV Measure?

Science.gov (United States)

Benson, Nicholas; Hulac, David M.; Kranzler, John H.

2010-01-01

Published empirical evidence for the Wechsler Adult Intelligence Scale--Fourth Edition (WAIS-IV) does not address some essential questions pertaining to the applied practice of intellectual assessment. In this study, the structure and cross-age invariance of the latest WAIS-IV revision were examined to (a) elucidate the nature of the constructs…

Generation IV nuclear reactors: Current status and future prospects

International Nuclear Information System (INIS)

Locatelli, Giorgio; Mancini, Mauro; Todeschini, Nicola

2013-01-01

Generation IV nuclear power plants (GEN IV NPPs) are supposed to become, in many countries, an important source of base load power in the middle–long term (2030–2050). Nowadays there are many designs of these NPPs but for political, strategic and economic reasons only few of them will be deployed. International literature proposes many papers and reports dealing with GEN IV NPPs, but there is an evident difference in the types and structures of the information and a general unbiased overview is missing. This paper fills the gap, presenting the state-of-the-art for GEN IV NPPs technologies (VHTR, SFR, SCWR, GFR, LFR and MSR) providing a comprehensive literature review of the different designs, discussing the major R and D challenges and comparing them with other advanced technologies available for the middle- and long-term energy market. The result of this research shows that the possible applications for GEN IV technologies are wider than current NPPs. The economics of some GEN IV NPPs is similar to actual NPPs but the “carbon cost” for fossil-fired power plants would increase the relative valuation. However, GEN IV NPPs still require substantial R and D effort, preventing short-term commercial adoption. - Highlights: • Generation IV reactors are the middle–long term technology for nuclear energy. • This paper provides an overview and a taxonomy for the designs under consideration. • R and D efforts are in the material, heat exchangers, power conversion unit and fuel. • The life cycle costs are competitive with other innovative technologies. • The hydrogen economy will foster the development of Generation IV reactors

IVS Organization

Science.gov (United States)

2004-01-01

International VLBI Service (IVS) is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The goals are: To provide a service to support geodetic, geophysical and astrometric research and operational activities. To promote research and development activities in all aspects of the geodetic and astrometric VLBI technique. To interact with the community of users of VLBI products and to integrate VLBI into a global Earth observing system.

Coupled electron-ion Monte Carlo simulation of hydrogen molecular crystals

Science.gov (United States)

Rillo, Giovanni; Morales, Miguel A.; Ceperley, David M.; Pierleoni, Carlo

2018-03-01

We performed simulations for solid molecular hydrogen at high pressures (250 GPa ≤ P ≤ 500 GPa) along two isotherms at T = 200 K (phase III) and at T = 414 K (phase IV). At T = 200 K, we considered likely candidates for phase III, the C2c and Cmca12 structures, while at T = 414 K in phase IV, we studied the Pc48 structure. We employed both Coupled Electron-Ion Monte Carlo (CEIMC) and Path Integral Molecular Dynamics (PIMD). The latter is based on Density Functional Theory (DFT) with the van der Waals approximation (vdW-DF). The comparison between the two methods allows us to address the question of the accuracy of the exchange-correlation approximation of DFT for thermal and quantum protons without recurring to perturbation theories. In general, we find that atomic and molecular fluctuations in PIMD are larger than in CEIMC which suggests that the potential energy surface from vdW-DF is less structured than the one from quantum Monte Carlo. We find qualitatively different behaviors for systems prepared in the C2c structure for increasing pressure. Within PIMD, the C2c structure is dynamically partially stable for P ≤ 250 GPa only: it retains the symmetry of the molecular centers but not the molecular orientation; at intermediate pressures, it develops layered structures like Pbcn or Ibam and transforms to the metallic Cmca-4 structure at P ≥ 450 GPa. Instead, within CEIMC, the C2c structure is found to be dynamically stable at least up to 450 GPa; at increasing pressure, the molecular bond length increases and the nuclear correlation decreases. For the other two structures, the two methods are in qualitative agreement although quantitative differences remain. We discuss various structural properties and the electrical conductivity. We find that these structures become conducting around 350 GPa but the metallic Drude-like behavior is reached only at around 500 GPa, consistent with recent experimental claims.

Independent examination of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV): what does the WAIS-IV measure?

Science.gov (United States)

Benson, Nicholas; Hulac, David M; Kranzler, John H

2010-03-01

Published empirical evidence for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) does not address some essential questions pertaining to the applied practice of intellectual assessment. In this study, the structure and cross-age invariance of the latest WAIS-IV revision were examined to (a) elucidate the nature of the constructs measured and (b) determine whether the same constructs are measured across ages. Results suggest that a Cattell-Horn-Carroll (CHC)-inspired structure provides a better description of test performance than the published scoring structure does. Broad CHC abilities measured by the WAIS-IV include crystallized ability (Gc), fluid reasoning (Gf), visual processing (Gv), short-term memory (Gsm), and processing speed (Gs), although some of these abilities are measured more comprehensively than are others. Additionally, the WAIS-IV provides a measure of quantitative reasoning (QR). Results also suggest a lack of cross-age invariance resulting from age-related differences in factor loadings. Formulas for calculating CHC indexes and suggestions for interpretation are provided. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Oxygen Atom Transfer Using an Iron(IV)-Oxo Embedded in a Tetracyclic N-Heterocyclic Carbene System: How Does the Reactivity Compare to Cytochrome P450 Compound I?

Science.gov (United States)

Cantú Reinhard, Fabián G; de Visser, Sam P

2017-02-24

N-Heterocyclic carbenes (NHC) are commonly featured as ligands in transition metal catalysis. Recently, a cyclic system containing four NHC groups with a central iron atom was synthesized and its iron(IV)-oxo species, [Fe IV (O)(cNHC 4 )] 2+ , was characterized. This tetracyclic NHC ligand system may give the iron(IV)-oxo species unique catalytic properties as compared to traditional non-heme and heme iron ligand systems. Therefore, we performed a computational study on the structure and reactivity of the [Fe IV (O)(cNHC 4 )] 2+ complex in substrate hydroxylation and epoxidation reactions. The reactivity patterns are compared with cytochrome P450 Compound I and non-heme iron(IV)-oxo models and it is shown that the [Fe IV (O)(cNHC 4 )] 2+ system is an effective oxidant with oxidative power analogous to P450 Compound I. Unfortunately, in polar solvents, a solvent molecule will bind to the sixth ligand position and decrease the catalytic activity of the oxidant. A molecular orbital and valence bond analysis provides insight into the origin of the reactivity differences and makes predictions of how to further exploit these systems in chemical catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Industrial Waste Landfill IV upgrade package

International Nuclear Information System (INIS)

1994-01-01

The Y-12 Plant, K-25 Site, and ORNL are managed by DOE's Operating Contractor (OC), Martin Marietta Energy Systems, Inc. (Energy Systems) for DOE. Operation associated with the facilities by the Operating Contractor and subcontractors, DOE contractors and the DOE Federal Building result in the generation of industrial solid wastes as well as construction/demolition wastes. Due to the waste streams mentioned, the Y-12 Industrial Waste Landfill IV (IWLF-IV) was developed for the disposal of solid industrial waste in accordance to Rule 1200-1-7, Regulations Governing Solid Waste Processing and Disposal in Tennessee. This revised operating document is a part of a request for modification to the existing Y-12 IWLF-IV to comply with revised regulation (Rule Chapters 1200-1-7-.01 through 1200-1-7-.08) in order to provide future disposal space for the ORR, Subcontractors, and the DOE Federal Building. This revised operating manual also reflects approved modifications that have been made over the years since the original landfill permit approval. The drawings referred to in this manual are included in Drawings section of the package. IWLF-IV is a Tennessee Department of Environmental and Conservation/Division of Solid Waste Management (TDEC/DSWM) Class 11 disposal unit

IVS: Current Status and Future Plans

Science.gov (United States)

Behrend, D.; Nothnagel, A.; Petrachenko, W. T.; Tuccari, G.

2016-12-01

The International VLBI Service for Geodesy and Astrometry (IVS) is a globally operating service that coordinates and performs Very Long Baseline Interferometry (VLBI) activities through its constituent components. The VLBI activities are associated with the creation, provision, dissemination, and archiving of relevant VLBI data and products. The products mostly pertain to the determination of the celestial and terrestrial reference frames, the Earth orientation parameters (EOP), atmospheric parameters as well as other ancillary parameters. The IVS observational network currently consists of about 40 radio telescopes worldwide. Subsets of these telescopes (8-12 stations) participate in 24-hour observing sessions that are run several times per week and in 1-hour intensive sessions for UT1 determination every day. The current VLBI network was developed mainly in the 1970s and 1980s. A number of factors, including aging infrastructure and demanding new scientific requirements, started to challenge its future sustainability and relevance. In response, the IVS and other groups developed and started implementing the next generation VLBI system, called VGOS (VLBI Global Observing System), at existing and new sites. The VGOS network is expected to reach maturity in the early 2020s. We describe the current status, progress, and anticipated prospects of geodetic/astrometric VLBI and the IVS.

Zirconium (IV) complexes with some polymethylenediimines | Na ...

African Journals Online (AJOL)

The syntheses of zirconium (IV) complexes have been carried out by the reaction of oxozirconium (IV) chloride with the appropriate diimines (Schiff bases). The complexes were isolated as yellow solids which are stable to heat. The complexes were found to be insoluble in most solvents. The infrared spectra, elemental ...

Development of Electromagnetic Analysis Model for IV-CEAPI

Energy Technology Data Exchange (ETDEWEB)

Park, Jinseok; Jang, Yongtae; Lee, Myounggoo; Cho, Yeonho; Kim, Hyunmin [KEPCO Engineering and Construction, Inc., Daejeon (Korea, Republic of); Hong, Hoonbin; Baek, Minho [Woojin Inc., Osan (Korea, Republic of)

2016-05-15

There are many different types of position indicators such as reed switch type, ultrasonic type, solenoid type, etc. Through an analysis of strengths and weakness of those types, solenoid type was selected for an IV-CEAPI. Although solenoid type CEAPIs have been used world-wide, the IV-CEAPI is to be very different from the conventional designs due to its harsh operating environment. The concept of the IV-CEAPI is simple as shown in Figure 1. The coil is made of mineral insulated wire to be able to operate inside reactor vessel. The CEA is connected to the shaft which is made of ferromagnetic material. As the CEA position varies, the inductance variation is detected by the inductance meter located outside the vessel. Unlike the conventional ones, the IV-CEAPI used only one coil to eliminate coil connection point and electric components inside vessel. A finite element model was developed to calculate inductance of the solenoid type IV-CEAPI. The model considers eddy current effect to calculate frequency dependent inductance value. Analyses were performed to produce an inductance curve to the shaft position.

Development of Electromagnetic Analysis Model for IV-CEAPI

International Nuclear Information System (INIS)

Park, Jinseok; Jang, Yongtae; Lee, Myounggoo; Cho, Yeonho; Kim, Hyunmin; Hong, Hoonbin; Baek, Minho

2016-01-01

There are many different types of position indicators such as reed switch type, ultrasonic type, solenoid type, etc. Through an analysis of strengths and weakness of those types, solenoid type was selected for an IV-CEAPI. Although solenoid type CEAPIs have been used world-wide, the IV-CEAPI is to be very different from the conventional designs due to its harsh operating environment. The concept of the IV-CEAPI is simple as shown in Figure 1. The coil is made of mineral insulated wire to be able to operate inside reactor vessel. The CEA is connected to the shaft which is made of ferromagnetic material. As the CEA position varies, the inductance variation is detected by the inductance meter located outside the vessel. Unlike the conventional ones, the IV-CEAPI used only one coil to eliminate coil connection point and electric components inside vessel. A finite element model was developed to calculate inductance of the solenoid type IV-CEAPI. The model considers eddy current effect to calculate frequency dependent inductance value. Analyses were performed to produce an inductance curve to the shaft position

The affinity plutonium(IV) for nitrogen donor ligands

International Nuclear Information System (INIS)

Jarvis, N.V.; Hancock, R.D.

1994-01-01

Established ligand design principles are used to predict the solution chemistry of Pu(IV) with nitrogen donor ligands which do not contain carboxylate donors. pK a 's of the nitrogen donors are lowered by addition of hydroxyalkyl groups causing Pu(IV) to have a greater affinity for these ligands than for hydroxide. Potentiometric studies using the ligands N,N,N'N',N''-pentakis(2-hydroxypropyl)-1,4,7-triazaheptane; N,N,N',N',N''-pentakis(2-hydroxyethyl)-1,4,7-triazaheptane; N,N,N',N',N'-tetrakis(2-hydroxyethyl)-1,2-diaminoethane; N,N,N',N'-tetrakis(2-hydroxyethyl)-trans-1,2-diaminocyclohexane; 1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane and N,N-bis(2-hydroxyethyl)glycine with Pu(IV) showed that Pu(IV) has a considerable aqueous solution chemistry with these ligands. Data were processed by the ESTA library of programs and stability constants for all the systems are reported. Implications for selective ligand design for Pu(IV) are discussed. (orig.)

NNDSS - Table IV. Tuberculosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2016.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

NNDSS - Table IV. Tuberculosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2014.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

NNDSS - Table IV. Tuberculosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2015.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

DSM-IV: a nosology sold before its time?

Science.gov (United States)

Zimmerman, M; Jampala, V C; Sierles, F S; Taylor, M A

1991-04-01

The purpose of this study was to determine whether American psychiatrists believe that DSM-IV is being published too soon after DSM-III-R. The authors conducted a mail survey of the attitudes of practicing psychiatrists (N = 454), residency program directors (N = 128), residents (N = 1,331), and researchers (N = 196) toward the scheduled publication of DSM-IV in the early 1990s. They found that the majority of all four groups believed that DSM-IV is being published prematurely. In contrast to respondents who believed that the timing of DSM-IV is appropriate, those who indicated that it is being published too soon had more recently completed their residency training and also believed that DSM-III-R was published prematurely. There was no association between the psychiatrists' responses and their theoretical orientation, Board certification status, ownership of the DSM manuals, the length of time they had used DSM-III, and the diagnostic manual (DSM-III or DSM-III-R) they were currently using. The belief that DSM-IV is being published too soon could contribute to underuse of DSM-IV by substantial numbers of psychiatrists. Thus, to foster compliance with it, APA must preserve in its efforts to demonstrate that the advantages of publishing it in 1993 outweigh the disadvantages of adopting yet another manual.

Dipeptidyl-peptidase IV (DPP-IV) inhibitor delays tolerance to anxiolytic effect of ethanol and withdrawal-induced anxiety in rats.

Science.gov (United States)

Sharma, Ajaykumar N; Pise, Ashish; Sharma, Jay N; Shukla, Praveen

2015-06-01

Dipeptidyl-peptidase IV (DPP-IV) is an enzyme responsible for the metabolism of endogenous gut-derived hormone, glucagon-like peptide-1 (GLP-1). DPP-IV is known for its role in energy homeostasis and pharmacological blockade of this enzyme is a recently approved clinical strategy for the management of type II diabetes. Accumulating evidences suggest that enzyme DPP-IV can affect spectrum of central nervous system (CNS) functions. However, little is known about the role of this enzyme in ethanol-mediated neurobehavioral complications. The objective of the present study was to examine the impact of DPP-IV inhibitor, sitagliptin on the development of tolerance to anxiolytic effect of ethanol and anxiety associated with ethanol withdrawal in rats. A dose-response study revealed that sitaglitpin (20 mg/kg, p.o.) per se exhibit anxiolytic effect in the elevated plus maze (EPM) test in rats. Tolerance to anxiolytic effect of ethanol (2 g/kg, i.p.; 8 % w/v) was observed from 7(th) day of ethanol-diet (6 % v/v) consumption. In contrast, tolerance to anxiolytic effect of ethanol was delayed in rats that were treated daily with sitagliptin (20 mg/kg, p.o.) as tolerance was observed from 13(th)day since commencement of ethanol-diet consumption. Discontinuation of rats from ethanol-diet after 15-days of ethanol consumption resulted in withdrawal anxiety between 8 h and 12 h post-abstinence. However, rats on 15-day ethanol-diet with concomitant sitagliptin (20 mg/kg, p.o.) treatment exhibited delay in appearance (24 h post-withdrawal) of withdrawal anxiety. In summary, DPP-IV inhibitors may prove as an attractive research strategy against ethanol tolerance and dependence.

Stage III & IV colon and rectal cancers share a similar genetic profile: a review of the Oregon Colorectal Cancer Registry.

Science.gov (United States)

Gawlick, Ute; Lu, Kim C; Douthit, Miriam A; Diggs, Brian S; Schuff, Kathryn G; Herzig, Daniel O; Tsikitis, Vassiliki L

2013-05-01

Determining the molecular profile of colon and rectal cancers offers the possibility of personalized cancer treatment. The purpose of this study was to determine whether known genetic mutations associated with colorectal carcinogenesis differ between colon and rectal cancers and whether they are associated with survival. The Oregon Colorectal Cancer Registry is a prospectively maintained, institutional review board-approved tissue repository with associated demographic and clinical information. The registry was queried for any patient with molecular analysis paired with clinical data. Patient demographics, tumor characteristics, microsatellite instability status, and mutational analysis for p53, AKT, BRAF, KRAS, MET, NRAS, and PIK3CA were analyzed. Categorical variables were compared using chi-square tests. Continuous variables between groups were analyzed using Mann-Whitney U tests. Kaplan-Meier analysis was used for survival studies. Comparisons of survival were made using log-rank tests. The registry included 370 patients: 69% with colon cancer and 31% with rectal cancer. Eighty percent of colon cancers and 68% of rectal cancers were stages III and IV. Mutational analysis found no significant differences in detected mutations between colon and rectal cancers, except that there were significantly more BRAF mutations in colon cancers compared with rectal cancers (10% vs 0%, P colon versus rectal cancers when stratified by the presence of KRAS, PIK3CA, and BRAF mutations. Stage III and IV colon and rectal cancers share similar molecular profiles, except that there were significantly more BRAF mutations in colon cancers compared with rectal cancers. Copyright © 2013 Elsevier Inc. All rights reserved.

Molecular epidemiology of human oral Chagas disease outbreaks in Colombia.

Directory of Open Access Journals (Sweden)

Juan David Ramírez

Full Text Available BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, displays significant genetic variability revealed by six Discrete Typing Units (TcI-TcVI. In this pathology, oral transmission represents an emerging epidemiological scenario where different outbreaks associated to food/beverages consumption have been reported in Argentina, Bolivia, Brazil, Ecuador and Venezuela. In Colombia, six human oral outbreaks have been reported corroborating the importance of this transmission route. Molecular epidemiology of oral outbreaks is barely known observing the incrimination of TcI, TcII, TcIV and TcV genotypes. METHODOLOGY AND PRINCIPAL FINDINGS: High-throughput molecular characterization was conducted performing MLMT (Multilocus Microsatellite Typing and mtMLST (mitochondrial Multilocus Sequence Typing strategies on 50 clones from ten isolates. Results allowed observing the occurrence of TcI, TcIV and mixed infection of distinct TcI genotypes. Thus, a majority of specific mitochondrial haplotypes and allelic multilocus genotypes associated to the sylvatic cycle of transmission were detected in the dataset with the foreseen presence of mitochondrial haplotypes and allelic multilocus genotypes associated to the domestic cycle of transmission. CONCLUSIONS: These findings suggest the incrimination of sylvatic genotypes in the oral outbreaks occurred in Colombia. We observed patterns of super-infection and/or co-infection with a tailored association with the severe forms of myocarditis in the acute phase of the disease. The transmission dynamics of this infection route based on molecular epidemiology evidence was unraveled and the clinical and biological implications are discussed.

Coordinative saturation and the chemistry of triscyclopentadienyl thorium (IV) alkyls and alkenyls

International Nuclear Information System (INIS)

Wachter, W.A.

1976-01-01

Air- and moisture-sensitive (C 5 H 5 ) 3 Th(IV)R compounds (R = alkyl, alkenyl) were prepared by reacting (C 5 H 5 ) 3 Th(IV)Cl with the corresponding Grignard or lithium reagent in toluene at -78 0 . They were characterized by elemental analysis, molecular weight, and pmr, infrared, and Raman spectroscopy. The fluxional behavior in the nmr indicates a sigmatropic rearrangement with an activation energy of 8 to 9 kcal/mole. Alcoholysis is faster and more selective for alkane formation than in the analogous uranium system. In aromatic solvents the compounds exhibit first-order decomposition kinetics. Relative thermal stabilities are neopentyl > allyl > n-butyl > 2-cis-2-butenyl > 2-trans-2-butenyl > i-propyl. Respective half-lives of these compounds at 167 0 C are 7500, 566, 96, 39, 21, and 7 hr. Alkanes are the major product for R = alkyl. Retention of configuration is noted for R = cis- and trans-2-butenyl. k/sub H//k/sub D/ is 2.4 for R = n-butyl. The results are consistent with coordinative saturation about the Th center blocking β-elimination. The solid product was also crystallized, and x-ray diffraction results reveal a bridged dimer ((C 5 H 5 ) 2 (C 5 H 4 )Th) 2 . To each Th are bound three rings in a pentahapto fashion and one ring, which is bound in a pentahapto fashion to the other Th center, in a monohapto fashion. These results suggest a short-lived intermediate, possibly an ylid, prior to dimerization. The photochemical decomposition of triscyclopentadienyl Th(IV) isopropyl leads to the formation of propene, propane, and an insoluble green solid. The solid analyzes as (C 15 H 15 Th) 2 , has a temperature-independent paramagnetism of 18.45 x 10 -4 cgs, and exhibits vibrational frequencies characteristic of pentahaptocyclopentadienyl ligands

Calcium Increases Xylella fastidiosa Surface Attachment, Biofilm Formation, and Twitching Motility

Science.gov (United States)

Cruz, Luisa F.; Cobine, Paul A.

2012-01-01

Xylella fastidiosa is a plant-pathogenic bacterium that forms biofilms inside xylem vessels, a process thought to be influenced by the chemical composition of xylem sap. In this work, the effect of calcium on the production of X. fastidiosa biofilm and movement was analyzed under in vitro conditions. After a dose-response study with 96-well plates using eight metals, the strongest increase of biofilm formation was observed when medium was supplemented with at least 1.0 mM CaCl2. The removal of Ca by extracellular (EGTA, 1.5 mM) and intracellular [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA/AM), 75 μM] chelators reduced biofilm formation without compromising planktonic growth. The concentration of Ca influenced the force of adhesion to the substrate, biofilm thickness, cell-to-cell aggregation, and twitching motility, as shown by assays with microfluidic chambers and other assays. The effect of Ca on attachment was lost when cells were treated with tetracycline, suggesting that Ca has a metabolic or regulatory role in cell adhesion. A double mutant (fimA pilO) lacking type I and type IV pili did not improve biofilm formation or attachment when Ca was added to the medium, while single mutants of type I (fimA) or type IV (pilB) pili formed more biofilm under conditions of higher Ca concentrations. The concentration of Ca in the medium did not significantly influence the levels of exopolysaccharide produced. Our findings indicate that the role of Ca in biofilm formation may be related to the initial surface and cell-to-cell attachment and colonization stages of biofilm establishment, which rely on critical functions by fimbrial structures. PMID:22194297

Advanced Silicon Carbide from Molecular Engineering and Actinide Fuels

International Nuclear Information System (INIS)

Meyer, D.J.M.; Garcia, J.; Guillaneux, D.; Wong-Chi-Man, M.; Moreau, J.J.E.

2008-01-01

In the frame of nuclear fuels studies for generation IV, carbides or oxycarbides assemblies are one of the engaged material for high temperature reactors. The design of the fuels is not yet defined but some structures are actually considered with SiC as matrix for the actinide fuel. In this work we have studied the synthesis of a multi-scale structure controlled SiC matrix using molecular silicon organometallic precursors. The aim of this work was to develop a way to obtain multi-scale SiC matrix material which could be engineered to fit in any fuel structure defined for generation IV fuels. The control of this multi-scale structure was done using several simulation methods specific of the low temperature solution synthesis of the precursor. In a first step, we have focused our effort on the synthesis of the SiC material. A first level of template was successfully done by the use of solid silica 500 nm balls. A second level of template was studied by the use of meso-porous silica, structured at a 50 nm level. At least, supra-molecular simulation in non aqueous media was considered with the difficulty to build a molecular assembly (inverse micelles). In a second step, we have functionalized the primary silane phase with actinide complexing agent in order to blend directly the actinide inside this primary phase in a controlled way. During these studies, a new one pot synthesis route to obtain the functionalized primary silane phase was developed. (authors)

Dsm-iv hypochondriasis in primary care

OpenAIRE

Escobar, JI; Gara, M; Waitzkin, H; Silver, RC; Holman, A; Compton, W

1998-01-01

The object of this study was to assess the prevalence and correlates of the DSM-IV diagnosis of hypochondriasis in a primary care setting. A large sample (N = 1456) of primary care users was given a structured interview to make diagnoses of mood, anxiety, and somatoform disorders and estimate levels of disability. The prevalence of hypochondriasis (DSM-IV) was about 3%. Patients with this disorder had higher levels of medically unexplained symptoms (abridged somatization) and were more impair...

Piliation of Lactobacillus rhamnosus GG Promotes Adhesion, Phagocytosis, and Cytokine Modulation in Macrophages

Science.gov (United States)

Vargas García, Cynthia E.; Petrova, Mariya; Claes, Ingmar J. J.; De Boeck, Ilke; Verhoeven, Tine L. A.; Dilissen, Ellen; von Ossowski, Ingemar; Palva, Airi; Bullens, Dominique M.; Vanderleyden, Jos

2015-01-01

Recently, spaCBA-encoded pili on the cell surface of Lactobacillus rhamnosus GG were identified to be key molecules for binding to human intestinal mucus and Caco-2 intestinal epithelial cells. Here, we investigated the role of the SpaCBA pilus of L. rhamnosus GG in the interaction with macrophages in vitro by comparing the wild type with surface mutants. Our results show that SpaCBA pili play a significant role in the capacity for adhesion to macrophages and also promote bacterial uptake by these phagocytic cells. Interestingly, our data suggest that SpaCBA pili also mediate anti-inflammatory effects by induction of interleukin-10 (IL-10) mRNA and reduction of interleukin-6 (IL-6) mRNA in a murine RAW 264.7 macrophage cell line. These pili appear to mediate these effects indirectly by promoting close contact with the macrophages, facilitating the exertion of anti-inflammatory effects by other surface molecules via yet unknown mechanisms. Blockage of complement receptor 3 (CR3), previously identified to be a receptor for streptococcal pili, significantly decreased the uptake of pilus-expressing strains in RAW 264.7 cells, while the expression of IL-10 and IL-6 mRNA by these macrophages was not affected by this blocking. On the other hand, blockage of Toll-like receptor 2 (TLR2) significantly reduced the expression of IL-6 mRNA irrespective of the presence of pili. PMID:25576613

The dependence of C IV broad absorption line properties on accompanying Si IV and Al III absorption: relating quasar-wind ionization levels, kinematics, and column densities

Energy Technology Data Exchange (ETDEWEB)

Filiz Ak, N.; Brandt, W. N.; Schneider, D. P.; Trump, J. R. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3 (Canada); Anderson, S. F. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Hamann, F. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Pâris, I. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, P. [Institut d' Astrophysique de Paris, Universite Paris 6, F-75014 Paris (France); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); York, Don, E-mail: nfilizak@astro.psu.edu [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States)

2014-08-20

We consider how the profile and multi-year variability properties of a large sample of C IV Broad Absorption Line (BAL) troughs change when BALs from Si IV and/or Al III are present at corresponding velocities, indicating that the line of sight intercepts at least some lower ionization gas. We derive a number of observational results for C IV BALs separated according to the presence or absence of accompanying lower ionization transitions, including measurements of composite profile shapes, equivalent width (EW), characteristic velocities, composite variation profiles, and EW variability. We also measure the correlations between EW and fractional-EW variability for C IV, Si IV, and Al III. Our measurements reveal the basic correlated changes between ionization level, kinematics, and column density expected in accretion-disk wind models; e.g., lines of sight including lower ionization material generally show deeper and broader C IV troughs that have smaller minimum velocities and that are less variable. Many C IV BALs with no accompanying Si IV or Al III BALs may have only mild or no saturation.

Expression, purification, crystallization and preliminary crystallographic analysis of SpaA, a major pilin from Corynebacterium diphtheriae

International Nuclear Information System (INIS)

Kang, Hae Joo; Paterson, Neil G.; Baker, Edward N.

2009-01-01

SpaA, one of the major pilins of C. diphtheriae, has been expressed, purified and crystallized and X-ray diffraction data have been collected to 1.6 Å resolution. Bacterial pili are cell-surface organelles that are critically involved in adhesion to host cells, leading to the colonization of host tissues and the establishment of infections. Whereas the pili of Gram-negative bacteria have been extensively studied, those of Gram-positive bacteria came to light only recently after the discovery and characterization of Corynebacterium diphtheriae pili. These newly discovered pili are formed by the covalent polymerization of pilin subunits catalyzed by sortase enzymes, making them fundamentally different from the noncovalent pilin assemblies of Gram-negative bacteria. Here, the expression, crystallization and preliminary crystallographic analysis of SpaA, which forms the shaft of one of the three types of pili expressed by C. diphtheriae, are reported. SpaA 53–486 crystals diffracted to 1.6 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 34.9, b = 64.1, c = 198.7 Å, α = β = γ = 90°

Electrochemical studies of plutonium(IV) complexes in aqueous nitrate solutions

International Nuclear Information System (INIS)

Kim, Seong-Yun; Asakura, Toshihide; Morita, Yasuji

2005-01-01

Electrochemistry has been used to investigate the behavior of plutonium (IV) in 1-7 M HNO 3 solutions. These Pu(IV) complexes were found to be reduced quasi-reversibly to Pu(III) species. The formal redox potentials (E 0 ) for Pu(IV)/Pu(III) couples were determined to be +0.721, +0.712, +0.706, +0.705, +0.704, 0.694, and +0.696 V (vs. Ag/AgCl(SSE)) for Pu(IV) complexes in 1, 2, 3, 4, 5, 6, 7 M HNO 3 solutions, respectively. These results indicate that the reduction product of Pu(IV) is Pu(III), which is considerably stable in HNO 3 solution. (author)

Adherence of Moraxella bovis to cell cultures of bovine origin.

Science.gov (United States)

Annuar, B O; Wilcox, G E

1985-09-01

The adherence of five strains of Moraxella bovis to cell cultures was investigated. M bovis adhered to cultures of bovine corneal epithelial and Madin-Darby bovine kidney cells but not to cell types of non-bovine origin. Both piliated and unpiliated strains adhered but piliated strains adhered to a greater extent than unpiliated strains. Antiserum against pili of one strain inhibited adherence of piliated strains but caused only slight inhibition of adherence to the unpiliated strains. Treatment of bacteria with magnesium chloride caused detachment of pili from the bacterial cell and markedly inhibited adherence of piliated strains but caused only slight inhibition of adherence by the unpiliated strains. The results suggested that adhesion of piliated strains to cell cultures was mediated via pili but that adhesins other than pili may be involved in the attachment of unpiliated strains of M bovis to cells.

Crystal structure of ammonium octacyanomolybdate(IV) and rubidium octacyanomolybdate(IV)

Energy Technology Data Exchange (ETDEWEB)

Semenishin, D.I.; Glovyak, T.; Mys' kiv, M.G.

1985-11-01

The crystal structure of ammonium octacyanomolybdate(IV) and rubidium octacyanomolybdate(IV) has been determined by the single-crystal method on a Syntex P2/sub 1/ automatic diffractometer: ((NH/sub 4/)/sub 4/ Mo(CN)/sub 4/) 0.5H/sub 2/O (I) (space group Pma2, a = 15.550(3), b = 14.118(3), c = 7.438(1) A, Z = 4, R = 0.062) and Rb/sub 4/(Mo(CN)/sub 8/). 3H/sub 2/O (II) (space group P4/sub 1/2/sub 1/2, a = 9.300(10, c = 21.807(3) A, Z = 4, R = 0.065). The Mo atoms in structure I occupy two special positions (2(b) and 2(c)) and are each surrounded by eight CN ligands. The mean value of the Mo-C distances for Mo(1) is equal to 2.216 A, and the corresponding value for Mo(2) is 2.235 A. The mean Mo-N lengths are practically identical in both molybdenum anions and are equal to 3.353 A. The mean values of the C identical with N bond lengths in the Mo(1) and Mo(2) anions are 1.118 and 1.137 A, respectively. The MoCn angles vary from 175.0 to 178.4/sup 0/. The coordination sphere of the Mo(1) atom corresponds to a dodecahedron with a single twofold symmetry axis, and the coordination polyhedron of the Mo(2) atom in an antiprism of m symmetry. In structure II the Mo-C distances are within the 2.130-2.160-A range, and the Mo-N distances range from 3.290 to 3.307 A. The MoCN angles vary from 176.0 to 179.3/sup 0/, and the coordination polyhedron of (MoC/sub 8/) is a dodecahedron of 2 symmetry. The existence of two types of coordination of Mo in structure I is presently the only example among the structurally studied octahyanomolybdates(IV).

Kinetics of U(VI) reduction control kinetics of U(IV) reoxidation

International Nuclear Information System (INIS)

Senko, J.M.; Minyard, M.L.; Dempsey, B.A.; Roden, E.E.; Yeh, G.-T.; Burgos, W.D.

2006-01-01

For the in situ reductive immobilization of U to be an acceptable strategy for the removal of that element from groundwater, the long-term stability of U(IV) must be determined. Rates of biotransformation of Fe species influence the mineralogy of the resulting products (Fredrickson et al., 2003; Senko et al., 2005), and we hypothesize that the rate of U(VI) reduction influences the mineralogy of resultant U(IV) precipitates. We hypothesize that slower rates of U(VI) reduction will yield U(IV) phases that are more resistant to reoxidation, and will therefore be more stable upon cessation of electron donor addition. U(IV) phases formed by relatively slow reduction may be more crystalline or larger in comparison to their relatively rapidly-formed counterparts (Figure 1), thus limiting the reactivity of slowly-formed U(IV) phases toward various oxidants. The physical location of U(IV) precipitates relative to bacterial cells may also limit the reactivity of biogenic U(IV) phases. In this situation, we expect that precipitation of U(IV) within the bacterial cell may protect U(IV) from reoxidation by limiting physical contact between U(IV) and oxidants (Figure 1). We assessed the effect of U(VI) reduction rate on the subsequent reoxidation of biogenic U(IV) and are currently conducting column scale studies to determine whether U(VI) reduction rate can be manipulated by varying the electron donor concentration used to stimulate U(VI) reduction

The carbonate complexation of plutonium(IV)

International Nuclear Information System (INIS)

Hobart, D.E.; Palmer, P.D.; Newton, T.W.

1985-01-01

Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemistry of these complexes is also important in the areas of nuclear fuel reprocessing and purification, actinide separations, and environmental studies. This report describes initial experiments performed to determine the identity and equilibrium quotients of plutonium(IV) carbonate complexes. These experiments were performed at pH values between 7.2 and 9.6 using a spectrophotometric method. In addition, a brief review of the published literature on Pu(IV) carbonate complexes is presented. Since Pu(IV) exhibits low solubility in the near-neutral pH range, a complex-competition reaction where citrate ligands compete with carbonate ions for the plutonium will be employed. This will permit us to study the pure carbonate system; study the mixed carbonate/citrate system, and confirm and extend the literature work on the pure citrate system. The current experiments have demonstrated the existence of at least three distinct species in the pH region studied. This work will continue in the extended study of the pure citrate system, followed by the investigation of the citrate/carbonate complex/competition reaction. 9 refs., 4 figs., 2 tabs

Måleegenskaper ved den norske versjonen av ADHD Rating Scale IV, Skoleversjon (ADHD-RS-IV Skole)

OpenAIRE

Kornør, Hege; Bøe, Tormod

2011-01-01

- Beskrivelse. ADHD-RS-IV Skole er et spørreskjema som skal fylles ut av lærere eller førskolelærere for å fange opp ADHD-symptomer hos barn og ungdom. Spørreskjemaet har 18 ledd med fire svaralternativer. Det tar under 20 minutter å fylle ut. Hovedskalaen og de to delskalaene skåres ved å summere enkeltskårer. Kompetansekrav for bruk av ADHD-RS-IV inkluderer generell opplæring i testbruk, samt yrkesstatus som psykolog, lege, annet helsepersonell med utdanning på mastergradsnivå, spesialpe...

The N-Terminal GYPSY Motif Is Required for Pilin-Specific Sortase SrtC1 Functionality in Lactobacillus rhamnosus Strain GG

NARCIS (Netherlands)

Douillard, François P.; Rasinkangas, Pia; Bhattacharjee, Arnab; Palva, Airi; Vos, De Willem M.

2016-01-01

Predominantly identified in pathogenic Gram-positive bacteria, sortase-dependent pili are also found in commensal species, such as the probiotic-marketed strain Lactobacillus rhamnosus strain GG. Pili are typically associated with host colonization, immune signalling and biofilm formation.

Dipeptidyl peptidase IV in two human glioma cell lines

Directory of Open Access Journals (Sweden)

A Sedo

2009-12-01

Full Text Available There is growing evidence that dipeptidyl peptidase IV [DPP-IV, EC 3.4.14.5] takes part in the metabolism of biologically active peptides participating in the regulation of growth and transformation of glial cells. However, the knowledge on the DPP-IV expression in human glial and glioma cells is still very limited. In this study, using histochemical and biochemical techniques, the DPP-IV activity was demonstrated in two commercially available human glioma cell lines of different transformation degree, as represented by U373 astrocytoma (Grade III and U87 glioblastoma multiforme (Grade IV lines. Higher total activity of the enzyme, as well as its preferential localisation in the plasma membrane, was observed in U87 cells. Compared to U373 population, U87 cells were morphologically more pleiomorphic, they were cycling at lower rate and expressing less Glial Fibrillary Acidic Protein. The data revealed positive correlation between the degree of transformation of cells and activity of DPP-IV. Great difference in expression of this enzyme, together with the phenotypic differences of cells, makes these lines a suitable standard model for further 57 studies of function of this enzyme in human glioma cells.

Psychological variables and Wechsler Adult Intelligence Scale-IV performance.

Science.gov (United States)

Gass, Carlton S; Gutierrez, Laura

2017-01-01

The MMPI-2 and WAIS-IV are commonly used together in neuropsychological evaluations yet little is known about their interrelationships. This study explored the potential influence of psychological factors on WAIS-IV performance in a sample of 180 predominantly male veteran referrals that underwent a comprehensive neuropsychological examination in a VA Medical Center. Exclusionary criteria included failed performance validity testing and self-report distortion on the MMPI-2. A Principal Components Analysis was performed on the 15 MMPI-2 content scales, yielding three broader higher-order psychological dimensions: Internalized Emotional Dysfunction (IED), Externalized Emotional Dysfunction (EED), and Fear. Level of IED was not related to performance on the WAIS-IV Full Scale IQ or its four indexes: (Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed). EED was not related to WAIS-IV performance. Level of Fear, which encompasses health preoccupations (HEA) and distorted perceptions (BIZ), was significantly related to WAIS-IV Full Scale IQ and Verbal Comprehension. These results challenge the common use of high scores on the MMPI-2 IED measures (chiefly depression and anxiety) to explain deficient WAIS-IV performance. In addition, they provide impetus for further investigation of the relation between verbal intelligence and Fear.

BALTICA IV. Plant maintenance for managing life and performance

Energy Technology Data Exchange (ETDEWEB)

Hietanen, S; Auerkari, P [eds.; VTT Manufacturing Technology, Espoo (Finland). Operational Reliability

1999-12-31

BALTICA IV International Conference on Plant Maintenance Managing Life and performance held on September 7-9, 1998 on board M/S Silja Symphony on its cruise between Helsinki-Stockholm and at Aavaranta in Kirkkonummi. The BALTICA IV conference provides a forum for the transfer of technology from applied research to practice. This is one of the two volumes of the proceedings of the BALTICA IV International Conference on Plant Maintenance Managing Life and Performance. The BALTICA IV conference focuses on new technology, recent experience and applications of condition and life management, and on improvements in maintenance strategies for safe and economical operation of power plants. (orig.)

BALTICA IV. Plant maintenance for managing life and performance

Energy Technology Data Exchange (ETDEWEB)

Hietanen, S.; Auerkari, P. [eds.] [VTT Manufacturing Technology, Espoo (Finland). Operational Reliability

1998-12-31

BALTICA IV International Conference on Plant Maintenance Managing Life and performance held on September 7-9, 1998 on board M/S Silja Symphony on its cruise between Helsinki-Stockholm and at Aavaranta in Kirkkonummi. The BALTICA IV conference provides a forum for the transfer of technology from applied research to practice. This is one of the two volumes of the proceedings of the BALTICA IV International Conference on Plant Maintenance Managing Life and Performance. The BALTICA IV conference focuses on new technology, recent experience and applications of condition and life management, and on improvements in maintenance strategies for safe and economical operation of power plants. (orig.)

Glycogen branching enzyme (GBE1) mutation causing equine glycogen storage disease IV.

Science.gov (United States)

Ward, Tara L; Valberg, Stephanie J; Adelson, David L; Abbey, Colette A; Binns, Matthew M; Mickelson, James R

2004-07-01

Comparative biochemical and histopathological evidence suggests that a deficiency in the glycogen branching enzyme, encoded by the GBE1 gene, is responsible for a recently identified recessive fatal fetal and neonatal glycogen storage disease (GSD) in American Quarter Horses termed GSD IV. We have now derived the complete GBE1 cDNA sequences for control horses and affected foals, and identified a C to A substitution at base 102 that results in a tyrosine (Y) to stop (X) mutation in codon 34 of exon 1. All 11 affected foals were homozygous for the X34 allele, their 11 available dams and sires were heterozygous, and all 16 control horses were homozygous for the Y34 allele. The previous findings of poorly branched glycogen, abnormal polysaccharide accumulation, lack of measurable GBE1 enzyme activity and immunodetectable GBE1 protein, coupled with the present observation of abundant GBE1 mRNA in affected foals, are all consistent with the nonsense mutation in the 699 amino acid GBE1 protein. The affected foal pedigrees have a common ancestor and contain prolific stallions that are likely carriers of the recessive X34 allele. Defining the molecular basis of equine GSD IV will allow for accurate DNA testing and the ability to prevent occurrence of this devastating disease affecting American Quarter Horses and related breeds.

Molecular characterization and phenotypical study of β-thalassemia in Tucumán, Argentina.

Science.gov (United States)

Lazarte, Sandra S; Mónaco, María E; Haro, Ana C; Jiménez, Cecilia L; Ledesma Achem, Myriam E; Issé, Blanca A

2014-01-01

The main hereditary hemoglobin (Hb) disorder in Argentina is β-thalassemia (β-thal). Molecular studies performed in the center of the country exhibited a marked prevalence of the codon 39 (C > T) and IVS-I-110 (G > A) mutations. The northwest region of Argentina has a different demographic history characterized by an important Spanish influx. Seventy-one β-thal carriers attending the Instituto de Bioquímica Aplicada, Tucumán, Argentina, were investigated for β-globin gene mutations by real-time polymerase chain reaction (RT-PCR). To examine the genotype-phenotype relationship, mean corpuscular volume (MCV), mean corpuscular Hb (MCH) and Hb A2 were measured. In order to recognize β-thal, Mentzer Index, Shine & Lal and Red Cell Distribution Width Index (RDWI), were calculated. The ethnic background of subjects revealed that 82.0% of the population was of Italian, Spanish and Arab origin. Seven mutations were detected: codon 39 (45.0%), IVS-I-1 (G > A) (22.5%), IVS-I-110 (16.3%), IVS-II-1 (G > A) (4.1%), IVS-I-1 (G > T) (2.0%), IVS-I-6 (T > C) (2.0%) and IVS-II-745 (G > C) (2.0%). In three families (6.1%), β-thal mutations were not determined. These results differed from other Argentinian studies because at present codon 39 and IVS-I-1 are the most prevalent; MCV, MCH and Hb A2 did not correlate with the type of mutation (β(0)/β(+)). Values of MCV (67.0 fL) and Hb A2 (4.85%) were unable to discriminate between them. Significant differences (p Argentina. Differences might represent the influence of Spanish immigration.

Redox reactions of U(IV) and Pu(IV) with H2O2 generated in nitric acid media by power ultrasound

International Nuclear Information System (INIS)

Moisy, P.; Venault, L.; Madic, C.; Nikitenko, S.

1998-01-01

Power ultrasound causes water molecule dissociation on H o and OH o radicals due to high local temperatures and pressures generated in the cavitation threshold. In nitric acid media scavenging of OH o radicals with NO 3 - followed by NO 3 o radicals hydrolysis leads to H 2 O 2 formation. It was shown that H 2 O 2 generated under the effect of ultrasound with the frequency 20 kHz and intensity 1-3 Wcm -2 (Ar atmosphere) oxidizes U(IV) to U(VI) or reduces Pu(IV) to Pu(III) in 1-4 M HNO 3 in the presence of antinitrous reagents ( N 2 H 5 NO 3 or NH 2 SO 3 H). The effect of HNO 3 concentration and ultrasonic intensity on the kinetics of U(IV) oxidation and Pu(IV) reduction was studied. (author)

Uranium(IV) adsorption by natural organic matter in anoxic sediments

Energy Technology Data Exchange (ETDEWEB)

Bone, Sharon E.; Dynes, James; Cliff, John B.; Barger, John

2017-01-09

Uranium is an important fuel source and a global environmental contaminant. It accumulates in the tetravalent state, U(IV), in anoxic sediments, including ore deposits, marine basins, and contaminated aquifers. However, very little is known about the speciation of U(IV) in low temperature geochemical environments, inhibiting the development of a conceptual model of U behavior. Until recently, U(IV) was assumed to exist predominantly as the sparingly soluble mineral uraninite (UO₂) in anoxic sediments; yet studies now show that UO₂ is not often dominant in these environments. However, a model of U(IV) speciation under environmentally relevant conditions has not yet been developed. Here we show that complexes of U(IV) adsorb on organic carbon and organic carbon-coated clays in an organic-rich natural substrate under field-relevant conditions. Whereas previous research assumed that the U(IV) product depended on the reduction pathway, our results demonstrate that UO₂ formation can be inhibited simply by decreasing the U:solid ratio. Thus, it is the number and type of surface ligands that controls U(IV) speciation subsequent to U(VI) reduction. Projections of U transport and bioavailability, and thus its threat to human and ecosystem health, must consider retention of U(IV) ions within the local sediment environment.

Insights into early extracellular matrix evolution: spongin short chain collagen-related proteins are homologous to basement membrane type IV collagens and form a novel family widely distributed in invertebrates.

Science.gov (United States)

Aouacheria, Abdel; Geourjon, Christophe; Aghajari, Nushin; Navratil, Vincent; Deléage, Gilbert; Lethias, Claire; Exposito, Jean-Yves

2006-12-01

Collagens are thought to represent one of the most important molecular innovations in the metazoan line. Basement membrane type IV collagen is present in all Eumetazoa and was found in Homoscleromorpha, a sponge group with a well-organized epithelium, which may represent the first stage of tissue differentiation during animal evolution. In contrast, spongin seems to be a demosponge-specific collagenous protein, which can totally substitute an inorganic skeleton, such as in the well-known bath sponge. In the freshwater sponge Ephydatia mülleri, we previously characterized a family of short-chain collagens that are likely to be main components of spongins. Using a combination of sequence- and structure-based methods, we present evidence of remote homology between the carboxyl-terminal noncollagenous NC1 domain of spongin short-chain collagens and type IV collagen. Unexpectedly, spongin short-chain collagen-related proteins were retrieved in nonsponge animals, suggesting that a family related to spongin constitutes an evolutionary sister to the type IV collagen family. Formation of the ancestral NC1 domain and divergence of the spongin short-chain collagen-related and type IV collagen families may have occurred before the parazoan-eumetazoan split, the earliest divergence among extant animal phyla. Molecular phylogenetics based on NC1 domain sequences suggest distinct evolutionary histories for spongin short-chain collagen-related and type IV collagen families that include spongin short-chain collagen-related gene loss in the ancestors of Ecdyzosoa and of vertebrates. The fact that a majority of invertebrates encodes spongin short-chain collagen-related proteins raises the important question to the possible function of its members. Considering the importance of collagens for animal structure and substratum attachment, both families may have played crucial roles in animal diversification.

Molecular investigations of β-thalassemic children in Erbil governorate

Science.gov (United States)

Hasan, Ahmad N.; Al-Attar, Mustafa S.

2017-09-01

The present work studies the molecular investigation of 40 thalassemic carriers using polymerase chain reaction. Forty thalassemic carriers who were registered and treated at Erbil thalassemic center and twenty apparently healthy children have been included in the present study. Ages of both groups ranged between 1-18 years. Four primers used to detect four different beta thalassemia mutations they were codon 8/9, codon 8, codon 41/42 and IVS-1-5. The two most common mutations detected among thalassemia group were Cd8/9 with 8 cases (20%) and Cd-8 with 6 cases (15%) followed by codon 41/42 with 4 cases (10%) which investigated and detected for the first time in Erbil governorate through the present study and finally IVS-1-5 with 3 cases (7.5%), while no any cases detected among control group.

Internet Economics IV

Science.gov (United States)

2004-08-01

edts.): Internet Economics IV Technical Report No. 2004-04, August 2004 Information Systems Laboratory IIS, Departement of Computer Science University of...level agreements (SLA), Information technology (IT), Internet address, Internet service provider 16. PRICE CODE 17. SECURITY CLASSIFICATION 18... technology and its economic impacts in the Internet world today. The second talk addresses the area of AAA protocol, summarizing authentication

Electro-regeneration of Ce(IV) in real spent Cr-etching solutions

International Nuclear Information System (INIS)

Chen, Te-San; Huang, Kuo-Lin

2013-01-01

Highlights: • An electrochemical process is used to regenerate Ce(IV) in real (hazardous) spent TFT-LCD Cr-etching solutions. • The Ce(IV) yield on tested anodes was in order BDD > Pt > DSA. • A Neosepta CMX separator was better than Nafion ones to be used in the process. • The activation energy on Pt was 10.7 kJ/mol. • The obtained parameters are useful to design reactors for 100% Ce(IV) regeneration in real spent Cr-etching solutions. -- Abstract: This paper presents the electro-regeneration of Ce(IV) in real (hazardous) spent thin-film transistor liquid-crystal display (TFT-LCD) Cr-etching solutions. In addition to Ce(III) > Ce(IV) in diffusivity, a quasi-reversible behavior of Ce(III)/Ce(IV) was observed at both boron-doped diamond (BDD) and Pt disk electrodes. The Ce(IV) yield on Pt increased with increasing current density, and the best current efficiency (CE) was obtained at 2 A/2.25 cm 2 . The performance in terms of Ce(IV) yield and CE of tested anodes was in order BDD > Pt > dimensional stable anode (DSA). At 2 A/2.25 cm 2 on Pt and 40 °C for 90 min, the Ce(IV) yield, CE and apparent rate constant (k) for Ce(III) oxidation were 81.4%, 21.8% and 3.17 × 10 −4 s −1 , respectively. With the increase of temperature, the Ce(IV) yield, CE, and k increased (activation energy = 10.7 kJ/mol), but the specific electricity consumption decreased. The Neosepta CMX membrane was more suitable than Nafion-117 and Nafion-212 to be used as the separator of the Ce(IV) regeneration process. The obtained parameters are useful to design divided batch reactors for the Ce(IV) electro-regeneration in real spent Cr-etching solutions

Crystal structure of the apurinic/apyrimidinic endonuclease IV from Mycobacterium tuberculosis.

Science.gov (United States)

Zhang, Wei; Xu, Yueyang; Yan, Mengrong; Li, Shanshan; Wang, Huiying; Yang, Haitao; Zhou, Weihong; Rao, Zihe

2018-03-25

Endonuclease IV is a typical endonuclease of the apurinic-apyrimidinic (AP) or abasic endonuclease superfamily. It repairs damaged DNA through base excision repair by cleaving the DNA backbone immediately 5' of an AP site. In Mycobacterium tuberculosis, endonuclease IV is the major AP endonuclease. This enzyme is absent from mammalian cells, making it an attractive target for anti-tuberculosis drug development. In this study, the structure of the recombinant endonuclease IV from M. tuberculosis (MtbEndo IV) was determined at a high resolution of 1.18 Å. MtbEndo IV was found to have a classical α8β8-fold TIM barrel with loops on its surface connecting the α-helices and β-strands that constitute a groove for DNA binding. Three zinc ions were identified at the active site. A comparison between the structures of MtbEndo IV and Escherichia coli End IV suggested that Gln32 of MtbEndo IV may plays a role in regulating substrate binding. Copyright © 2018. Published by Elsevier Inc.

77 FR 64398 - Order of Succession for HUD Region IV

Science.gov (United States)

2012-10-19

... Region IV AGENCY: Office of Field Policy and Management, HUD. ACTION: Notice of Order of Succession... Field Offices (Region IV). This Order of Succession supersedes all previous Orders of Succession for HUD Region IV. DATES: Effective Date: October 9, 2012. FOR FURTHER INFORMATION CONTACT: Lawrence D. Reynolds...

The Capsicum annuum class IV chitinase ChitIV interacts with receptor-like cytoplasmic protein kinase PIK1 to accelerate PIK1-triggered cell death and defence responses

Science.gov (United States)

Kim, Dae Sung; Kim, Nak Hyun; Hwang, Byung Kook

2015-01-01

The pepper receptor-like cytoplasmic protein kinase, CaPIK1, which mediates signalling of plant cell death and defence responses was previously identified. Here, the identification of a class IV chitinase, CaChitIV, from pepper plants (Capsicum annuum), which interacts with CaPIK1 and promotes CaPIK1-triggered cell death and defence responses, is reported. CaChitIV contains a signal peptide, chitin-binding domain, and glycol hydrolase domain. CaChitIV expression was up-regulated by Xanthomonas campestris pv. vesicatoria (Xcv) infection. Notably, avirulent Xcv infection rapidly induced CaChitIV expression in pepper leaves. Bimolecular fluorescence complementation and co-immunoprecipitation revealed that CaPIK1 interacts with CaChitIV in planta, and that the CaPIK1–CaChitIV complex is localized mainly in the cytoplasm and plasma membrane. CaChitIV is also localized in the endoplasmic reticulum. Transient co-expression of CaChitIV with CaPIK1 enhanced CaPIK1-triggered cell death response and reactive oxygen species (ROS) and nitric oxide (NO) bursts. Co-silencing of both CaChitIV and CaPIK1 in pepper plants conferred enhanced susceptibility to Xcv infection, which was accompanied by a reduced induction of cell death response, ROS and NO bursts, and defence response genes. Ectopic expression of CaPIK1 in Arabidopsis enhanced basal resistance to Hyaloperonospora arabidopsidis infection. Together, the results suggest that CaChitIV positively regulates CaPIK1-triggered cell death and defence responses through its interaction with CaPIK1. PMID:25694549

Determination of U(IV) and hydrazine nitrate by volumetry

International Nuclear Information System (INIS)

Cao Xi; Wang Nanjie; Zhang Tao; Wang Lin; Guo Yuhua

2006-01-01

To be determined U(IV) and hydrazine nitrate in exist together, chromium (VI) and 1,10-phenanthroline is used individually as oxidation titrator and indicator for U(IV), and N-bromineimino and methyl red is used individually as oxidation titrator and indicator for hydrazine nitrate, U(IV) and hydrazine nitrate in the same sample is determined sequentially in the nitric acid by adjusting concentration of nitric acid. Results show that the precision is better than 2.0% when the mass concentration of U(IV) is ranged over 5.5-205 mg/mL; and the precision is better than 2.0% when the concentration of hydrazine nitrate is ranged over 0.05-1.0 mol/L. (authors)

Complexation of Plutonium (IV) With Sulfate At Variable Temperatures

International Nuclear Information System (INIS)

Y. Xia; J.I. Friese; D.A. Moore; P.P. Bachelor; L. Rao

2006-01-01

The complexation of plutonium(IV) with sulfate at variable temperatures has been investigated by solvent extraction method. A NaBrO 3 solution was used as holding oxidant to maintain the plutonium(IV) oxidation state throughout the experiments. The distribution ratio of Pu(IV) between the organic and aqueous phases was found to decrease as the concentrations of sulfate were increased. Stability constants of the 1:1 and 1:2 Pu(IV)-HSO 4 - complexes, dominant in the aqueous phase, were calculated from the effect of [HSO 4 - ] on the distribution ratio. The enthalpy and entropy of complexation were calculated from the stability constants at different temperatures using the Van't Hoff equation

The I-V Measurement System for Solar Cells Based on MCU

International Nuclear Information System (INIS)

Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng

2011-01-01

In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

The I-V Measurement System for Solar Cells Based on MCU

Energy Technology Data Exchange (ETDEWEB)

Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng, E-mail: phonixchen79@yahoo.com.cn [Department of physics science and technology, Wuhan University of Technology, Wuhan city, Hubei Province, 430070 (China)

2011-02-01

In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

Some studies on the reaction between nitrous acid and plutonium(IV)

International Nuclear Information System (INIS)

Vasudeva Rao, P.R.; Bagawde, S.V.; Ramakrishna, V.V.; Patil, S.K.

1976-01-01

In the ion exchange and solvent extraction studies nitrous acid is used as an oxidant for Pu(IV) in perchloric acid. Earlier studies had indicated that Pu(IV) forms complex with nitrous acid. The present investigation aimed to study this complex formation by solvent extraction and spectrophotometric methods, revealed that is no significant complex formation between Pu(IV) and nitrous acid. The high apparent equilibrium constant for the complex formation is caused by the partial reduction of Pu(IV) to Pu(III) by nitrous acid. The nitrate complexing is negligible in the case of Th(IV) and Np(IV) as well. Systematic investigation on the redox reactions of plutonium in different oxidation states with nitrous acid is now in progress. The preliminary results obtained indicate that Pu(IV) is reduced to Pu(III) by nitrous acid with a rate that can be conveniently followed spectrophotometrically. (T.I.)

C-terminal region of DNA ligase IV drives XRCC4/DNA ligase IV complex to chromatin

International Nuclear Information System (INIS)

Liu, Sicheng; Liu, Xunyue; Kamdar, Radhika Pankaj; Wanotayan, Rujira; Sharma, Mukesh Kumar; Adachi, Noritaka; Matsumoto, Yoshihisa

2013-01-01

Highlights: •Chromatin binding of XRCC4 is dependent on the presence of DNA ligase IV. •C-terminal region of DNA ligase IV alone can recruit itself and XRCC4 to chromatin. •Two BRCT domains of DNA ligase IV are essential for the chromatin binding of XRCC4. -- Abstract: DNA ligase IV (LIG4) and XRCC4 form a complex to ligate two DNA ends at the final step of DNA double-strand break (DSB) repair through non-homologous end-joining (NHEJ). It is not fully understood how these proteins are recruited to DSBs. We recently demonstrated radiation-induced chromatin binding of XRCC4 by biochemical fractionation using detergent Nonidet P-40. In the present study, we examined the role of LIG4 in the recruitment of XRCC4/LIG4 complex to chromatin. The chromatin binding of XRCC4 was dependent on the presence of LIG4. The mutations in two BRCT domains (W725R and W893R, respectively) of LIG4 reduced the chromatin binding of LIG4 and XRCC4. The C-terminal fragment of LIG4 (LIG4-CT) without N-terminal catalytic domains could bind to chromatin with XRCC4. LIG4-CT with W725R or W893R mutation could bind to chromatin but could not support the chromatin binding of XRCC4. The ability of C-terminal region of LIG4 to interact with chromatin might provide us with an insight into the mechanisms of DSB repair through NHEJ

Long-term risk of complications after mid-urethral sling IVS implantation

Directory of Open Access Journals (Sweden)

Grzegorz Surkont

2015-02-01

Full Text Available [b]Introduction[/b]. Results of short-term evaluation of multifilament microporous midurethral tape IVS differ a great deal. During the first year of implantation, erosions have been observed in 0%–26% of operated women. Long-term observations are rare. They suggest high risk of extrusion and infection even after years of implantation. [b]Objective[/b]. The purpose of the study was to evaluate long-term risk of complications after IVS implantation. Material and methods. Between 2001–2005, 72 women were operated on with the use of IVS mid-urethral tape. [b]Results[/b]. Two women had vaginal erosions during the first 3 months after the operation. Twelve women had vaginal erosions, purulent vaginal discharge, with IVS tape sticking out of the abdominal wall or vagina, and abdominal abscess. These complications were diagnosed between 9 months and 6 years after IVS implantation. The patients were operated on vaginally and open abdominally, 1–5 times because of complications after IVS implantation. [b]Conclusions[/b]. In the case of post-IVS complication, as much tape as possible should be excised. Long-term follow up on patients with IVS implantation should be recommended to the centres where IVS tape was used, even to patients after removal of the tape. Risk of erosion, extrusion and infection after midurethral multifilament microporous IVS tape implantation is too high – which is the reason it should no longer be used.

Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus

International Nuclear Information System (INIS)

Carr, Stephen B.; Makris, George; Phillips, Simon E. V.; Thomas, Christopher D.

2006-01-01

The crystallization and data collection of topoisomerase IV from S. aureus is described. Phasing by molecular replacement proved difficult owing to the presence of translational NCS and strategies used to overcome this are discussed. DNA topoisomerase IV removes undesirable topological features from DNA molecules in order to help maintain chromosome stability. Two constructs of 56 and 59 kDa spanning the DNA-cleavage domain of the A subunit of topoisomerase IV from Staphylococcus aureus (termed GrlA56 and GrlA59) have been crystallized. Crystals were grown at 291 K using the sitting-drop vapour-diffusion technique with PEG 3350 as a precipitant. Preliminary X-ray analysis revealed that GrlA56 crystals belong to space group P2 1 , diffract to a resolution of 2.9 Å and possess unit-cell parameters a = 83.6, b = 171.5, c = 87.8 Å, β = 90.1°, while crystals of GrlA59 belong to space group P2 1 2 1 2, with unit-cell parameters a = 41.5, b = 171.89, c = 87.9 Å. These crystals diffract to a resolution of 2.8 Å. This is the first report of the crystallization and preliminary X-ray analysis of the DNA-cleavage domain of a topoisomerase IV from a Gram-positive organism

Identification and characterization of a dipeptidyl peptidase IV inhibitor from aronia juice

Energy Technology Data Exchange (ETDEWEB)

Kozuka, Miyuki [Department of Health and Nutrition, Faculty of Human Science, Hokkaido Bunkyo University, Eniwa 061-1449 (Japan); Yamane, Takuya, E-mail: t-yamane@pharm.hokudai.ac.jp [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812 (Japan); Nakano, Yoshihisa [Center for Research and Development Bioresources, Research Organization for University-Community Collaborations, Osaka Prefecture University, Sakai, Osaka 599-8570 (Japan); Nakagaki, Takenori [Institute of Food Sciences, Nakagaki Consulting Engineer Co., Ltd, Nishi-ku, Sakai 593-8328 (Japan); Ohkubo, Iwao [Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Higashi-ku, Sapporo 065-0013 (Japan); Ariga, Hiroyoshi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812 (Japan)

2015-09-25

Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified that cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside. - Highlights: • DPP IV activity is inhibited by aronia juice. • DPP IV inhibitor is cyanidin 3, 5-diglucoside in aronia juice. • DPP IV is inhibited by cyanidin 3, 5-diglucoside more than cyanidin and cyanidin 3-glucoside.

Magnetite Compensates for the Lack of a Pilin-Associated c-Type Cytochrome in Extracellular Electron Exchange

DEFF Research Database (Denmark)

Liu, Fanghua; Rotaru, Amelia-Elena; Shrestha, Pravin

2015-01-01

investigation revealed that magnetite attached to the electrically conductive pili of Geobacter species in a manner reminiscent of the association of the multi-heme c-type cytochrome OmcS with the pili of Geobacter sulfurreducens. Magnetite conferred extracellular electron capabilities on an Omc...

The Inner Membrane Protein PilG Interacts with DNA and the Secretin PilQ in Transformation.

Directory of Open Access Journals (Sweden)

Stephan A Frye

Full Text Available Expression of type IV pili (Tfp, filamentous appendages emanating from the bacterial surface, is indispensable for efficient neisserial transformation. Tfp pass through the secretin pore consisting of the membrane protein PilQ. PilG is a polytopic membrane protein, conserved in Gram-positive and Gram-negative bacteria, that is required for the biogenesis of neisserial Tfp. PilG null mutants are devoid of pili and non-competent for transformation. Here, recombinant full-length, truncated and mutated variants of meningococcal PilG were overexpressed, purified and characterized. We report that meningococcal PilG directly binds DNA in vitro, detected by both an electromobility shift analysis and a solid phase overlay assay. PilG DNA binding activity was independent of the presence of the consensus DNA uptake sequence. PilG-mediated DNA binding affinity was mapped to the N-terminus and was inactivated by mutation of residues 43 to 45. Notably, reduced meningococcal transformation of DNA in vivo was observed when PilG residues 43 to 45 were substituted by alanine in situ, defining a biologically significant DNA binding domain. N-terminal PilG also interacted with the N-terminal region of PilQ, which previously was shown to bind DNA. Collectively, these data suggest that PilG and PilQ in concert bind DNA during Tfp-mediated transformation.

Androgenetic alopecia: new insights into the pathogenesis and mechanism of hair loss [v1; ref status: indexed, http://f1000r.es/5ar

Directory of Open Access Journals (Sweden)

Rodney Sinclair

2015-08-01

Full Text Available The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease. Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata. A new model for the progression of AGA is presented.

Androgenetic alopecia: new insights into the pathogenesis and mechanism of hair loss

Science.gov (United States)

Sinclair, Rodney; Torkamani, Niloufar; Jones, Leslie

2015-01-01

The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease. Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata. A new model for the progression of AGA is presented. PMID:26339482

Måleegenskaper ved den norske versjonen av ADHD Rating Scale – IV Hjemmeversjon (ADHD-RS-IV Hjemme)

OpenAIRE

Kornør, Hege; Bøe, Tormod

2011-01-01

- Beskrivelse. ADHD-RS-IV Hjemme er et spørreskjema som skal fylles ut av mor, far, verge eller besteforeldre for å fange opp ADHD-symptomer hos barn og ungdom. Spørreskjemaet har 18 ledd med fire svaralternativer. Det tar under 20 minutter å fylle ut. Hovedskalaen og de to delskalaene skåres ved å summere enkeltskårer. Kompetansekrav for bruk av ADHD-RS-IV inkluderer generell opplæring i testbruk, samt yrkesstatus som psykolog, lege, annet helsepersonell med utdanning på ...

12 CFR Appendix IV to Part 27 - Home Loan Data Submission

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Home Loan Data Submission IV Appendix IV to Part 27 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR HOUSING HOME LOAN DATA SYSTEM Pt. 27, App. IV Appendix IV to Part 27—Home Loan Data Submission ER21JN94.003 ER21JN94...

The Role of Dipeptidyl Peptidase IV in Lung Metastasis of Breast Cancer Cells

Science.gov (United States)

1999-05-01

Our studies focused on (1) cloning and sequencing of wild-type endothelial DPP IV (wtDPP IV) and preparation of truncated DPP IV ( tDPP IV); (2...that was identical to hepatic DPP IV. Acid extraction of rat lung yielded a tDPP IV, which was an effective inhibitor of breast cancer cell adhesion to

Supernova Driving. IV. The Star-formation Rate of Molecular Clouds

Science.gov (United States)

Padoan, Paolo; Haugbølle, Troels; Nordlund, Åke; Frimann, Søren

2017-05-01

We compute the star-formation rate (SFR) in molecular clouds (MCs) that originate ab initio in a new, higher-resolution simulation of supernova-driven turbulence. Because of the large number of well-resolved clouds with self-consistent boundary and initial conditions, we obtain a large range of cloud physical parameters with realistic statistical distributions, which is an unprecedented sample of star-forming regions to test SFR models and to interpret observational surveys. We confirm the dependence of the SFR per free-fall time, SFRff, on the virial parameter, α vir, found in previous simulations, and compare a revised version of our turbulent fragmentation model with the numerical results. The dependences on Mach number, { M }, gas to magnetic pressure ratio, β, and compressive to solenoidal power ratio, χ at fixed α vir are not well constrained, because of random scatter due to time and cloud-to-cloud variations in SFRff. We find that SFRff in MCs can take any value in the range of 0 ≤ SFRff ≲ 0.2, and its probability distribution peaks at a value of SFRff ≈ 0.025, consistent with observations. The values of SFRff and the scatter in the SFRff-α vir relation are consistent with recent measurements in nearby MCs and in clouds near the Galactic center. Although not explicitly modeled by the theory, the scatter is consistent with the physical assumptions of our revised model and may also result in part from a lack of statistical equilibrium of the turbulence, due to the transient nature of MCs.

Photoactivation of Diiodido-Pt(IV) Complexes Coupled to Upconverting Nanoparticles.

Science.gov (United States)

Perfahl, Stefanie; Natile, Marta M; Mohamad, Heba S; Helm, Christiane A; Schulzke, Carola; Natile, Giovanni; Bednarski, Patrick J

2016-07-05

The preparation, characterization, and surface modification of upconverting lanthanide-doped hexagonal NaGdF4 nanocrystals attached to light sensitive diiodido-Pt(IV) complexes is presented. The evaluation for photoactivation and cytotoxicity of the novel carboxylated diiodido-Pt(IV) cytotoxic prodrugs by near-infrared (NIR) light (λ = 980 nm) is also reported. We attempted two different strategies for attachment of light-sensitive diiodido-Pt(IV) complexes to Yb,Er- and Yb,Tm-doped β-NaGdF4 upconverting nanoparticles (UCNPs) in order to provide nanohybrids, which offer unique opportunities for selective drug activation within the tumor cells and subsequent spatiotemporal controlled drug release by NIR-to-visible light-upconversion: (A) covalent attachment of the Pt(IV) complex via amide bond formation and (B) carboxylate exchange of oleate on the surface of the UCNPs with diiodido-Pt(IV) carboxylato complexes. Initial feasibility studies showed that NIR applied by a 980 nm laser had only a slight effect on the stability of the various diiodido-Pt(IV) complexes, but when UCNPs were present more rapid loss of the ligand-metal-charge transfer (LMCT) bands of the diiodido-Pt(IV) complexes was observed. Furthermore, Pt released from the Pt(IV) complexes platinated calf-thymus DNA (ct-DNA) more rapidly when NIR was applied compared to dark controls. Of the two attachment strategies, method A with the covalently attached diiodido-Pt(IV) carboxylates via amide bond formation proved to be the most effective method for generating UCNPs that release Pt when irradiated with NIR; the released Pt was also able to bind irreversibly to calf thymus DNA. Nonetheless, only ca. 20% of the Pt on the surface of the UCNPs was in the Pt(IV) oxidation state, the rest was Pt(II), indicating chemical reduction of the diiodido-Pt(IV) prodrug by the UCNPs. Cytotoxicity studies with the various UCNP-Pt conjugates and constructs, tested on human leukemia HL60 cells in culture, indicated a

Synthesis and Characterization of Organ Tin (IV) Complexes ...

African Journals Online (AJOL)

User

2012-08-21

Aug 21, 2012 ... the reference drug. In addition, within the diorganotin(IV) complexes, monomeric type (3) exhibited a slightly better activity as compared to the organodistannoxane dimer types (1 and 4). Key words: Preliminary in vitro cytotoxic assay, organotin(IV) complexes, comparison study. INTRODUCTION. Although ...

A Comprehensive Functional Analysis of NTRK1 Missense Mutations Causing Hereditary Sensory and Autonomic Neuropathy Type IV (HSAN IV).

Science.gov (United States)

Shaikh, Samiha S; Chen, Ya-Chun; Halsall, Sally-Anne; Nahorski, Michael S; Omoto, Kiyoyuki; Young, Gareth T; Phelan, Anne; Woods, Christopher Geoffrey

2017-01-01

Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA-Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach. © 2016 WILEY PERIODICALS, INC.

Comparative genome and transcriptome analysis reveals distinctive surface characteristics and unique physiological potentials of Pseudomonas aeruginosa ATCC 27853

KAUST Repository

Cao, Huiluo

2017-06-12

Pseudomonas aeruginosa ATCC 27853 was isolated from a hospital blood specimen in 1971 and has been widely used as a model strain to survey antibiotics susceptibilities, biofilm development, and metabolic activities of Pseudomonas spp.. Although four draft genomes of P. aeruginosa ATCC 27853 have been sequenced, the complete genome of this strain is still lacking, hindering a comprehensive understanding of its physiology and functional genome.Here we sequenced and assembled the complete genome of P. aeruginosa ATCC 27853 using the Pacific Biosciences SMRT (PacBio) technology and Illumina sequencing platform. We found that accessory genes of ATCC 27853 including prophages and genomic islands (GIs) mainly contribute to the difference between P. aeruginosa ATCC 27853 and other P. aeruginosa strains. Seven prophages were identified within the genome of P. aeruginosa ATCC 27853. Of the predicted 25 GIs, three contain genes that encode monoxoygenases, dioxygenases and hydrolases that could be involved in the metabolism of aromatic compounds. Surveying virulence-related genes revealed that a series of genes that encode the B-band O-antigen of LPS are lacking in ATCC 27853. Distinctive SNPs in genes of cellular adhesion proteins such as type IV pili and flagella biosynthesis were also observed in this strain. Colony morphology analysis confirmed an enhanced biofilm formation capability of ATCC 27853 on solid agar surface compared to Pseudomonas aeruginosa PAO1. We then performed transcriptome analysis of ATCC 27853 and PAO1 using RNA-seq and compared the expression of orthologous genes to understand the functional genome and the genomic details underlying the distinctive colony morphogenesis. These analyses revealed an increased expression of genes involved in cellular adhesion and biofilm maturation such as type IV pili, exopolysaccharide and electron transport chain components in ATCC 27853 compared with PAO1. In addition, distinctive expression profiles of the

Report for 2012 from the Bordeaux IVS Analysis Center

Science.gov (United States)

Charlot, Patrick; Bellanger, Antoine; Bouffet, Romuald; Bourda, Geraldine; Collioud, Arnaud; Baudry, Alain

2013-01-01

This report summarizes the activities of the Bordeaux IVS Analysis Center during the year 2012. The work focused on (i) regular analysis of the IVS-R1 and IVS-R4 sessions with the GINS software package; (ii) systematic VLBI imaging of the RDV sessions and calculation of the corresponding source structure index and compactness values; (iii) investigation of the correlation between astrometric position instabilities and source structure variations; and (iv) continuation of our VLBI observational program to identify optically-bright radio sources suitable for the link with the future Gaia frame. Also of importance is the 11th European VLBI Network Symposium, which we organized last October in Bordeaux and which drew much attention from the European and International VLBI communities.

Sorption studies of radionuclides on a modified mesoporous cerium(IV) silicate

International Nuclear Information System (INIS)

Sepehrian, H.; Tarbiat Moallem University, Tehran; Ghannadi-Maragheh, M.; Yavari, R.; Khanchi, A.R.; Waqif-Husain, S.

2008-01-01

Five different samples of a new sorbent, modified mesoporous cerium(IV) silicate have been prepared with various mole ratios of Si/Ce and Cetyltrimethylammonium bromide (CTMABr) as template. XRD, nitrogen sorption, SEM, IR, thermogravimetry and sorption of radionuclides have been studied. Separation of Hg(II)-Th(IV), Hg(II)-Zr(IV) and Rb(I)-Zr(IV) have been developed on columns of this novel sorbent. (author)

78 FR 45592 - DeltaPoint Capital IV, LP;

Science.gov (United States)

2013-07-29

..., Suite 160, Pittsford, NY 14534. The financing was contemplated for working capital. The financing is... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662] DeltaPoint Capital IV, LP; Notice Seeking... given that DeltaPoint Capital IV, L.P., 45 East Avenue, 6th Floor, Rochester, NY 14604, Federal...

Measurement of Ce(IV) Concentration in Foam Decontaminant containing Fluorosurfactant

Energy Technology Data Exchange (ETDEWEB)

Jung, Chong Hun; Yang, H. B.; Yoon, I. H.; Choi, W. K.; Moon, J. K. [KAERI, Daejeon (Korea, Republic of); Lee, J. S. [Gachon University, Seongnam (Korea, Republic of)

2016-05-15

To improve the stability of the foam, surfactants and inorganic materials such as nanoparticles can be added. A nanoparticle-based foam decontaminant is composed of a surfactant and nanoparticles for the generation and maintenance of foam, and a chemical decontamination agent made of Ce(IV) dissolved in nitric acid. Ce(IV) will be reduced to Ce(III) through the decontamination process. Oxidizing the cerium (III) can be reused as a decontamination agent, Ce(IV). Oxidation treatment technology by ozone uses its strong oxidizing power. It can be regarded as an environmentally friendly process, because ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site, and used ozone can be decomposed immediately. A concentration analysis of Ce(IV) in foam decontaminant containing a surfactant is necessary prior to the derivation of optimal conditions for the regeneration of Ce(III) through ozonation treatment. A UV spectrometric method using the absorbance or potentiometric method with a potential difference in Ce(III)/Ce(IV), or a potentiometric titration method using Fe (II), can be used for a Ce(IV) concentration analysis. A UV spectrometric method has a problem receiving the influence of the surfactant, and a potentiometric method is difficult to use because of the problem of an insignificant change in the potential difference value of the Ce(III)/Ce(IV). Thus, the present study was undertaken to determine whether the potentiometric titration method can be used for an analysis of the Ce(IV) concentration in the nanoparticle-based foam decontaminant containing surfactant. It will be effectively used for the Ce(IV) concentration measurement, in relation to the subsequent research on the derivation of optimal conditions for the regeneration of Ce(III) through ozonation treatment.

Two-stage precipitation of neptunium (IV) oxalate

International Nuclear Information System (INIS)

Luerkens, D.W.

1983-07-01

Neptunium (IV) oxalate was precipitated using a two-stage precipitation system. A series of precipitation experiments was used to identify the significant process variables affecting precipitate characteristics. Process variables tested were input concentrations, solubility conditions in the first stage precipitator, precipitation temperatures, and residence time in the first stage precipitator. A procedure has been demonstrated that produces neptunium (IV) oxalate particles that filter well and readily calcine to the oxide

Antibodies against Shigella flexneri adhesion molecule outer ...

African Journals Online (AJOL)

OMP) as an adhesion factor and examine its ability to cross-react with the OMPs of other Shigella species. Methods: OMP was isolated from the bacterium S. flexneri after shaving the pili using a pili bacterial cutter in a solution of 0.5 ...

β-Zeolite modified by ethylenediamine for sorption of Th(IV)

Energy Technology Data Exchange (ETDEWEB)

Liu, Peng; Wu, Hanyu; Yuan, Ni; Yin, Zhuoxin; Pan, Duoqiang; Wu, Wangsuo [Lanzhou Univ. (China). Radiochemistry Lab.; Ministry of Education, Lanzhou (China). Key Lab. of Special Function Materials and Structure Design

2017-08-01

β-Zeolite-EDA was modified with ethylenediamine (EDA) after synthesized. The synthesized material was characterized and used for removal of Th(IV) from aqueous solutions. The influences of pH, ionic strength, contact time, temperature and humic acid (HA) on Th(IV) sorption onto synthesized β-zeolite-EDA was studied by batch technique. The dynamic process showed that the sorption of Th(IV) onto β-zeolite-EDA matched the pseudo-second-order kinetics model. The sorption of Th(IV) on β-zeolite-EDA was significantly dependent on pH values, the sorption percentage increased markedly at pH 3.5-4.5, and then maintained a steady state as pH values increased. Through simulating the sorption isotherms by Langmuir, Freundlich and Dubini-Radushkevich (D-R) models, it could be seen respectively that the sorption pattern of Th(IV) on β-zeolite-EDA was mainly controlled by surface complexation, and that the sorption processes was endothermic and spontaneous. The presence of HA increased Th(IV) sorption on β-zeolite-EDA.

PLATO IV Accountancy Index.

Science.gov (United States)

Pondy, Dorothy, Comp.

The catalog was compiled to assist instructors in planning community college and university curricula using the 48 computer-assisted accountancy lessons available on PLATO IV (Programmed Logic for Automatic Teaching Operation) for first semester accounting courses. It contains information on lesson access, lists of acceptable abbreviations for…

Sorption of radionuclides on mesoporous Sn(IV) silicate: a new sorbent

Energy Technology Data Exchange (ETDEWEB)

Sepehrian, H. [Jaber Ibn Hayan Research Labs., Nuclear Science and Technology Research Inst., AEOI, Tehran (Iran); Dept. of Applied Chemistry, Univ. of Tarbiat Moallem, Tehran (Iran); Yavari, R.; Ghannadi Maragheh, M. [Jaber Ibn Hayan Research Labs., Nuclear Science and Technology Research Inst., AEOI, Tehran (Iran); Husain, S.W. [Dept. of Applied Chemistry, Univ. of Tarbiat Moallem, Tehran (Iran)

2008-07-01

Four different samples of mesoporous Sn(IV) silicate with varying mole ratio of Si/Sn have been used to study the sorption behavior of 18 radionuclides on these materials. Ion-exchange capacity, SEM, distribution coefficient and chemical stability have been studied and discussed. Separation of Tl(I) from Th(IV), Cs(I) from Th(IV) and Cs(I) from Zr(IV) have been developed on columns of this sorbent. (orig.)

Sorption of radionuclides on mesoporous Sn(IV) silicate: a new sorbent

International Nuclear Information System (INIS)

Sepehrian, H.; Yavari, R.; Ghannadi Maragheh, M.; Husain, S.W.

2008-01-01

Four different samples of mesoporous Sn(IV) silicate with varying mole ratio of Si/Sn have been used to study the sorption behavior of 18 radionuclides on these materials. Ion-exchange capacity, SEM, distribution coefficient and chemical stability have been studied and discussed. Separation of Tl(I) from Th(IV), Cs(I) from Th(IV) and Cs(I) from Zr(IV) have been developed on columns of this sorbent. (orig.)

Supporting Technology for Enhanced Oil Recovery-EOR Thermal Processes Report IV-12

Energy Technology Data Exchange (ETDEWEB)

Izequeido, Alexandor

2001-04-01

This report contains the results of efforts under the six tasks of the Ninth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 62 through 67. The first, second, third, fourth, fifth, sixth, seventh, eight, and ninth reports on Annex IV, [Venezuela MEM/USA-DOE Fossil Energy Report IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, and IV-8 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, DOE/BC-86/2/SP, DOE/BC-87/2/SP, DOE/BC-89/1/SP, DOE/BC-90/1/SP) DOE/BC-92/1/SP, DOE/BC-93/3/SP, and DOE/BC-95/3/SP] contain the results from the first 61 tasks. Those reports are dated April 1983, August 1984, March 1986, July 1! 987, November 1988, December 1989, October 1991, February 1993, and March 1995 respectively.

Sargent-IV Project. Development of new methodologies for safety analysis of Generation IV reactors; Proyecto SARGEB-IV. Desarrollo de nuevas metodologias de analisis de seguridad para reactores de Generacion IV

Energy Technology Data Exchange (ETDEWEB)

Queral, C.; Gallego, E.; Jimenez, G.

2013-07-01

The main result of this paper is the proposal for the addition of new ingredients in the safety analysis methodologies for Generation-IV reactors that integrates the features of probabilistic safety analysis within deterministic. This ensures a higher degree of integration between the classical deterministic and probabilistic methodologies.

Central administration of angiotensin IV rapidly enhances novel object recognition among mice.

Science.gov (United States)

Paris, Jason J; Eans, Shainnel O; Mizrachi, Elisa; Reilley, Kate J; Ganno, Michelle L; McLaughlin, Jay P

2013-07-01

Angiotensin IV (Val(1)-Tyr(2)-Ile(3)-His(4)-Pro(5)-Phe(6)) has demonstrated potential cognitive-enhancing effects. The present investigation assessed and characterized: (1) dose-dependency of angiotensin IV's cognitive enhancement in a C57BL/6J mouse model of novel object recognition, (2) the time-course for these effects, (3) the identity of residues in the hexapeptide important to these effects and (4) the necessity of actions at angiotensin IV receptors for procognitive activity. Assessment of C57BL/6J mice in a novel object recognition task demonstrated that prior administration of angiotensin IV (0.1, 1.0, or 10.0, but not 0.01 nmol, i.c.v.) significantly enhanced novel object recognition in a dose-dependent manner. These effects were time dependent, with improved novel object recognition observed when angiotensin IV (0.1 nmol, i.c.v.) was administered 10 or 20, but not 30 min prior to the onset of the novel object recognition testing. An alanine scan of the angiotensin IV peptide revealed that replacement of the Val(1), Ile(3), His(4), or Phe(6) residues with Ala attenuated peptide-induced improvements in novel object recognition, whereas Tyr(2) or Pro(5) replacement did not significantly affect performance. Administration of the angiotensin IV receptor antagonist, divalinal-Ang IV (20 nmol, i.c.v.), reduced (but did not abolish) novel object recognition; however, this antagonist completely blocked the procognitive effects of angiotensin IV (0.1 nmol, i.c.v.) in this task. Rotorod testing demonstrated no locomotor effects with any angiotensin IV or divalinal-Ang IV dose tested. These data demonstrate that angiotensin IV produces a rapid enhancement of associative learning and memory performance in a mouse model that was dependent on the angiotensin IV receptor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Transient Analysis Needs for Generation IV Reactor Concepts

International Nuclear Information System (INIS)

Siefken, L.J.; Harvego, E.A.; Coryell, E.W.; Davis, C.B.

2002-01-01

The importance of nuclear energy as a vital and strategic resource in the U. S. and world's energy supply mix has led to an initiative, termed Generation IV by the U.S. Department of Energy (DOE), to develop and demonstrate new and improved reactor technologies. These new Generation IV reactor concepts are expected to be substantially improved over the current generation of reactors with respect to economics, safety, proliferation resistance and waste characteristics. Although a number of light water reactor concepts have been proposed as Generation IV candidates, the majority of proposed designs have fundamentally different characteristics than the current generation of commercial LWRs operating in the U.S. and other countries. This paper presents the results of a review of these new reactor technologies and defines the transient analyses required to support the evaluation and future development of the Generation IV concepts. The ultimate objective of this work is to identify and develop new capabilities needed by INEEL to support DOE's Generation IV initiative. In particular, the focus of this study is on needed extensions or enhancements to SCDAP/RELAP5/3D code. This code and the RELAP5-3D code from which it evolved are the primary analysis tools used by the INEEL and others for the analysis of design-basis and beyond-design-basis accidents in current generation light water reactors. (authors)

Electrochemistry and Spectroelectrochemistry of the Pu (III/IV) and (IV/VI) Couples in Nitric Acid Systems

Energy Technology Data Exchange (ETDEWEB)

Lines, Amanda M. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Adami, Susan R. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Casella, Amanda J. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Sinkov, Sergey I. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Lumetta, Gregg J. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Bryan, Samuel A. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352

2017-09-20

The solution chemistry of Pu in nitric acid is explored via electrochemistry and spectroelectrochemistry. By utilizing and comparing these techniques, an improved understanding of Pu behavior and its dependence on nitric acid concentration can be achieved. Here the Pu (III/IV) couple is characterized using cyclic voltammetry, square wave voltammetry, and a spectroelectrochemical Nernst step. Results indicate the formal reduction potential of the couple shifts negative with increasing acid concentration and reversible electrochemistry is no longer attainable above 6 M HNO3. Spectroelectrochemistry is also used to explore the irreversible oxidation of Pu(IV) to Pu(VI) and shine light on the mechanism and acid dependence of the redox reaction.

Uranium (IV) carboxylates - I

Energy Technology Data Exchange (ETDEWEB)

Satpathy, K C; Patnaik, A K [Sambalpur Univ. (India). Dept. of Chemistry

1975-11-01

A few uranium(IV) carboxylates with monochloro and trichloro acetic acid, glycine, malic, citric, adipic, o-toluic, anthranilic and salicylic acids have been prepared by photolytic methods. The I.R. spectra of these compounds are recorded and basing on the spectral data, structure of the compounds have been suggested.

Solubility study of Tc(IV) in a granitic water

International Nuclear Information System (INIS)

Liu, D.J.; Yao, J.; Wang, B.; Bruggeman, C.; Maes, N.

2007-01-01

The deep geological disposal of the high level radioactive wastes is expected to be a safe disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO 4 - whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 .nH 2 O. Hence, the mobility of Tc(IV) in reducing groundwater may be limited by the solubility of TcO 2 .nH 2 O under these conditions. Due to this fact it is important to investigate the solubility of TcO 2 .nH 2 O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium(IV) was prepared by reduction of a technetate solution with Sn 2+ . The solubility of Tc(IV) has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and redistilled water is about (1.49 ∝ 1.86) x 10 -9 mol L -1 d -1 under aerobic conditions, while no Tc(IV) oxidation was detected in simulated groundwater and redistilled water under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The

1. IV toimus Kõrvekülas... / Hele Ellermaa

Index Scriptorium Estoniae

Ellermaa, Hele

2005-01-01

Toimus Hans Christian Anderseni 200. sünniaastapäevale ja rahvusvahelisele lasteraamatupäevale pühendatud IV Tartumaa lasteraamatupäev. Konkursile laekus 172 joonistust, 14 kirjatööd ja 73 paberlõikepilti. Laste tööde näitus on avatud Kõrveküla raamatukogus kuni 16. IV

Molecular, metabolic, and genetic control: An introduction

Science.gov (United States)

Tyson, John J.; Mackey, Michael C.

2001-03-01

The living cell is a miniature, self-reproducing, biochemical machine. Like all machines, it has a power supply, a set of working components that carry out its necessary tasks, and control systems that ensure the proper coordination of these tasks. In this Special Issue, we focus on the molecular regulatory systems that control cell metabolism, gene expression, environmental responses, development, and reproduction. As for the control systems in human-engineered machines, these regulatory networks can be described by nonlinear dynamical equations, for example, ordinary differential equations, reaction-diffusion equations, stochastic differential equations, or cellular automata. The articles collected here illustrate (i) a range of theoretical problems presented by modern concepts of cellular regulation, (ii) some strategies for converting molecular mechanisms into dynamical systems, (iii) some useful mathematical tools for analyzing and simulating these systems, and (iv) the sort of results that derive from serious interplay between theory and experiment.

Controlling applied to information processing: quality management applied to IP projects and IP services; Informationsverarbeitungs-Controlling: Qualitaetsmanagement fuer IV-Projekte und fuer IV-Service

Energy Technology Data Exchange (ETDEWEB)

Becker, B. [Vereinigung Deutscher Elektrizitaetswerke e.V. (VDEW), Frankfurt am Main (Germany); Beckers, F. [Isar-Amperwerke AG, Muenchen (Germany); Dewald, N. [Bayernwerk AG, Muenchen (Germany); Hauffe, P. [Pfalzwerke AG, Ludwigshafen am Rhein (Germany); Hein, F. [EVS AG Stuttgart (Germany); Hoederath, M. [Vereinigte Elektrizitaetswerke Westfalen AG (VEW), Dortmund (Germany); Seyen, R. [Staedtische Werke Nuernberg GmbH (Germany)

1998-01-12

The working group on information processing (IP) basics (in German: `IV-Grundlagen`) has prepared this contribution dealing with controlling applied to information processing. This new report, on the one hand, takes into consideration the role of the organizational IP unit as one offering its services to all sections of a company. On the other hand, information processing as an operational infrastructure influencing all business processes becomes increasingly important with respect to the competitiveness of the EVU. Therefore, quality management applied to IP projects and IP services must support this development. (orig./RHM) [Deutsch] Der VDEW Arbeitskreis `IV-Grundlagen` hat einen Beitrag zum Controlling fuer die Informationsverarbeitung erstellt. Hier geht zum einen die Rolle der Organisationseinheit IV als Dienstleister fuer alle Unternehmensbereiche ein. Zum anderen gewinnt die Informationsverarbeitung als betriebliche Infrastruktur fuer alle Geschaeftsprozesse zunehmende Bedeutung fuer die Wettbewerbsfaehigkeit der EVU. Das Qualitaetsmanagement fuer IV-Projekte und fuer IV-Service muss dies unterstuetzen. (orig./RHM)

Some reactions of hydrotris(3,5-dimethylpyrazolyl)-borato trichloroactinides(IV), MCl/sub 3/(HBL/sub 3/). THF (M=Th/sup IV/, U/sup IV/; L=3,5-dimethylpyrazolyl, THF=tetrahydrofuran)

Energy Technology Data Exchange (ETDEWEB)

Marcalo, J; Marques, N; Pires de Matos, A; Bagnall, K W

1986-08-01

The thorium(IV) and uranium(IV) compounds MCl/sub 2/(Cp)(HBL/sub 3/) (Cp=eta/sup 5/-C/sub 5/H/sub 5/), MCl/sub 2/(N(SiMe/sub 3/)/sub 2/)(HBL/sub 3/) and M(NPh/sub 2/)/sub 3/(HBL/sub 3/) have been prepared from MCl/sub 3/(HBL/sub 3/).THF. IR, near-IR-visible, /sup 1/H NMR and /sup 11/B NMR spectra are reported for these compounds.

Functions in Free-Format RPG IV

CERN Document Server

Martin, Jim

2009-01-01

Written especially for programmers adopting a free-format style, this manual explores the role of functions in writing RPG IV programs. Demonstrating the potential of functions, many topics are explored such as details about existing RPG IV built-in functions, writing new functions, using ILE concepts to use C functions, and utilizing IBM API's functions. Explaining how to write small programs, either as sub-procedures or modules, and how to gather those parts together to make programs that are easy to write and maintain, this is a natural next step for programmers familiar with a free-format

Vectorization at the KENO-IV code

International Nuclear Information System (INIS)

Asai, K.; Higuchi, K.; Katakura, J.

1986-01-01

The multigroup criticality safety code KENO-IV has been vectorized and tested on the FACOM VP-100 vector processor. At first, the vectorized KENO-IV on a scalar processor was slower than the original one by a factor of 1.4 because of the overhead introduced by vectorization. Making modifications of algorithms and techniques for vectorization, the vectorized version has become faster than the original one by a factor of 1.4 on the vector processor. For further speedup of the code, some improvements on compiler and hardware, especially on addition of Monte Carlo pipelines to the vector processor, are discussed

Pharmacophore Modeling and Molecular Docking Studies on Pinus roxburghii as a Target for Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Pawan Kaushik

2014-01-01

Full Text Available The present study attempts to establish a relationship between ethnopharmacological claims and bioactive constituents present in Pinus roxburghii against all possible targets for diabetes through molecular docking and to develop a pharmacophore model for the active target. The process of molecular docking involves study of different bonding modes of one ligand with active cavities of target receptors protein tyrosine phosphatase 1-beta (PTP-1β, dipeptidyl peptidase-IV (DPP-IV, aldose reductase (AR, and insulin receptor (IR with help of docking software Molegro virtual docker (MVD. From the results of docking score values on different receptors for antidiabetic activity, it is observed that constituents, namely, secoisoresinol, pinoresinol, and cedeodarin, showed the best docking results on almost all the receptors, while the most significant results were observed on AR. Then, LigandScout was applied to develop a pharmacophore model for active target. LigandScout revealed that 2 hydrogen bond donors pointing towards Tyr 48 and His 110 are a major requirement of the pharmacophore generated. In our molecular docking studies, the active constituent, secoisoresinol, has also shown hydrogen bonding with His 110 residue which is a part of the pharmacophore. The docking results have given better insights into the development of better aldose reductase inhibitor so as to treat diabetes related secondary complications.

Oligomerized backbone pilin helps piliated Lactococcus lactis to withstand shear flow.

Science.gov (United States)

Castelain, Mickaël; Duviau, Marie-Pierre; Oxaran, Virginie; Schmitz, Philippe; Cocaign-Bousquet, Muriel; Loubière, Pascal; Piard, Jean-Christophe; Mercier-Bonin, Muriel

2016-09-01

The present work focuses on the role of pili present at the cell surface of Lactococcus lactis in bacterial adhesion to abiotic (hydrophobic polystyrene) and biotic (mucin-coated polystyrene) surfaces. Native pili-displaying strains and isogenic derivatives in which pilins or sortase C structural genes had been modified were used. Surface physico-chemistry, morphology and shear-flow-induced detachment of lactococcal cells were evaluated. The involvement of pili in L. lactis adhesion was clearly demonstrated, irrespective of the surface characteristics (hydrophobic/hydrophilic, presence or not of specific binding sites). The accessory pilin, PilC, and the backbone pilin, PilB, were revealed to play a major role in adhesion, provided that the PilB was present in its polymerized form. Within the population fraction that remained attached to the surface under increasing shear flow, different association behaviors were observed, showing that pili could serve as anchoring sites thus hampering the effect of shear flow on cell orientation and detachment.

Functionalization of group IV semiconductors; Funktionalisierung von Gruppe IV-Halbleitern

Energy Technology Data Exchange (ETDEWEB)

Hoeb, Marco Andreas

2011-01-15

The present work is focused on the structural and electronic properties of thermally and photochemically grafted alkene molecules. The semiconductor substrates used in this work are the group IV-semiconductors silicon, diamond, and silicon carbide. On silicon, functionalization via the commonly known hydrosilylation reaction was performed. During thermal treatment in vacuum-distilled 1-octadecene, the alkene molecules covalently added to the substrate via Si-C bond formation, resulting in self-assembled organic monolayers. The reaction resulted in smooth and homogeneous alkyl-terminated surfaces. Static water contact angles were determined to be 113 . Photoelectron spectroscopy was performed and showed no evidence of surface oxidation. The high packing of the organic layers is indicated by the asymmetric methylene vibrational mode, which has been redshifted by -4 cm{sup -1} with respect to the liquid alkene mode position. The average molecular tilt-angle of the alkyl-molecules, relative to the surface normal, has been identified to be 34 . The transport properties have been determined to be dominated by tunneling processes. On diamond, first results on the thermal functionalization of hydrogen- and oxygen-terminated surfaces are demonstrated. Thermal functionalization with octadecene showed high selectivity, while hydrogenated diamond surfaces were found to be inert to the thermally induced reaction with alkenes. In contrast, alkene molecules were successfully grafted to oxygen-terminated sites via covalent C-O-C bonds. Reaction temperatures as high as 160 C were necessary to initiate the functionalization process.Wetting experiments on the alkyl-modified surfaces revealed contact angle values of 103 . The high quality of the monolayers on oxygenated surfaces was confirmed by IR-spectroscopy. In addition, polarized IR-measurements indicated a tilt angle of 23 . On silicon carbide, thermal and UV-induced alkoxylation were studied. Hydrofluoric acid treatment

Clinical significance of determination of serum collagen type IV (IV-C) and transforming growth factor beta1(TGF-β1) levels in patients with diabetic nephropathy

International Nuclear Information System (INIS)

Xie Hongfang; Peng Liang

2006-01-01

Objective: To investigate the clinical significance of determination of serum collagen type IV (IV-C) and transforming growth factor beta 1 (TGF-β 1 ) levels in patients with diabetic nephropathy. Methods: Serum IV-C levels ( with RIA) and TGF-β 1 levels (with ELISA) were determined in 30 controls and 105 patients with type II diabetis mellitus (45 with diabetic nephropathy and 60 without nephropathy). Results: The serum levels of IV-C and TGF-β 1 in diabetic patients with nephropathy were significantly higher than those in controls (P 0.05). Conclusion: Serum IV-C and TGF-β 1 , levels increased gradually as the diabetic nephropathy got more severe, they could be used as sensitive markers for early diagnosis of development of diabetic nephropathy. (authors)

Adaptable coordination of U(IV) in the 2D-(4,4) uranium oxalate network: From 8 to 10 coordinations in the uranium (IV) oxalate hydrates

International Nuclear Information System (INIS)

Duvieubourg-Garela, L.; Vigier, N.; Abraham, F.; Grandjean, S.

2008-01-01

Crystals of uranium (IV) oxalate hydrates, U(C 2 O 4 ) 2 .6H 2 O (1) and U(C 2 O 4 ) 2 .2H 2 O (2), were obtained by hydrothermal methods using two different U(IV) precursors, U 3 O 8 oxide and nitric U(IV) solution in presence of hydrazine to avoid oxidation of U(IV) into uranyl ion. Growth of crystals of solvated monohydrated uranium (IV) oxalate, U(C 2 O 4 ) 2 .H 2 O.(dma) (3), dma=dimethylamine, was achieved by slow diffusion of U(IV) into a gel containing oxalate ions. The three structures are built on a bi-dimensional complex polymer of U(IV) atoms connected through bis-bidentate oxalate ions forming [U(C 2 O 4 )] 4 pseudo-squares. The flexibility of this supramolecular arrangement allows modifications of the coordination number of the U(IV) atom which, starting from 8 in 1 increases to 9 in 3 and, finally increases, to 10 in 2. The coordination polyhedron changes from a distorted cube, formed by eight oxygen atoms of four oxalate ions, in 1, to a mono-capped square anti-prism in 3 and, finally, to a di-capped square anti-prism in 2, resulting from rotation of the oxalate ions and addition of one and two water oxygen atoms in the coordination of U(IV). In 1, the space between the ∞ 2 [U(C 2 O 4 ) 2 ] planar layers is occupied by non-coordinated water molecules; in 2, the space between the staggered ∞ 2 [U(C 2 O 4 ) 2 .2H 2 O] layers is empty, finally in 3, the solvate molecules occupy the interlayer space between corrugated ∞ 2 [U(C 2 O 4 ) 2 .H 2 O] sheets. The thermal decomposition of U(C 2 O 4 ) 2 .6H 2 O under air and argon atmospheres gives U 3 O 8 and UO 2 , respectively. - Graphical abstract: The adaptable environment of U(IV) in U(IV) oxalates: from eight cubic coordination in U(C 2 O 4 ) 2 .6H 2 O (a) completed by water oxygens to nine in [U(C 2 O 4 ) 2 .H 2 O](C 2 NH 5 ) (b) and ten coordination in U(C 2 O 4 ) 2 .2H 2 O (c)

Understanding Molecular Conduction: Old Wine in a New Bottle?

Science.gov (United States)

Ghosh, Avik

2007-03-01

Molecules provide an opportunity to test our understanding of fundamental non-equilibrium transport processes, as well as explore new device possibilities. We have developed a unified approach to nanoscale conduction, coupling bandstructure and electrostatics of the channel and contacts with a quantum kinetic theory of current flow. This allows us to describe molecular conduction at various levels of detail, -- from quantum corrected compact models, to semi-empirical models for quick physical insights, and `first-principles' calculations of current-voltage (I-V) characteristics with no adjustable parameters. Using this suite of tools, we can quantitatively explain various experimental I-Vs, including complex reconstructed silicon substrates. We find that conduction in most molecules is contact dominated, and limited by fundamental electrostatic and thermodynamic restrictions quite analogous to those faced by the silicon industry, barring a few interesting exceptions. The distinction between molecular and silicon electronics must therefore be probed at a more fundamental level. Ultra-short molecules are unique in that they possess large Coulomb energies as well as anomalous vibronic couplings with current flow -- in other words, strong non-equilibrium electron-electron and electron-phonon correlations. These effects yield prominent experimental signatures, but require a completely different modeling approach -- in fact, popular approaches to include correlation typically do not work for non-equilibrium. Molecules exhibit rich physics, including the ability to function both as weakly interacting current conduits (quantum wires) as well as strongly correlated charge storage centers (quantum dots). Theoretical treatment of the intermediate coupling regime is particularly challenging, with a large `fine structure constant' for transport that negates orthodox theories of Coulomb Blockade and phonon-assisted tunneling. It is in this regime that the scientific and

An Integrated Safety Assessment Methodology for Generation IV Nuclear Systems

International Nuclear Information System (INIS)

Leahy, Timothy J.

2010-01-01

The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Early work of the RSWG focused on defining a safety philosophy founded on lessons learned from current and prior generations of nuclear technologies, and on identifying technology characteristics that may help achieve Generation IV safety goals. More recent RSWG work has focused on the definition of an integrated safety assessment methodology for evaluating the safety of Generation IV systems. The methodology, tentatively called ISAM, is an integrated 'toolkit' consisting of analytical techniques that are available and matched to appropriate stages of Generation IV system concept development. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time.

DSM-V from the perspective of the DSM-IV experience.

Science.gov (United States)

Walsh, B Timothy

2007-11-01

This article provides a brief overview of the development of the diagnostic criteria for eating disorders in DSM-IV. The process by which DSM-IV was developed is reviewed, including perspectives on what constitutes diagnostic validity and clinical utility, and their importance in assessing proposed changes in diagnostic criteria. The question of whether alterations in diagnostic criteria would clearly improve clinical utility was a major consideration in the DSM-IV process. Because of concerns that changes in diagnostic criteria would be disruptive and might entail loss of established knowledge, the DSM-IV Task Force assumed a generally conservative stance vis-à-vis change. The process of developing DSM-V is just beginning, and it is far from clear what alterations in diagnostic criteria for eating disorders will occur. However, the evolution of DSM-IV may provide a useful perspective on the development of DSM-V. (c) 2007 by Wiley Periodicals, Inc.

Apparent formation constants of Pu(IV) and Th(IV) with humic acids determined by solvent extraction method

Energy Technology Data Exchange (ETDEWEB)

Sasaki, T.; Aoyama, S.; Yoshida, H.; Kobayashi, T.; Takagi, I. [Tokyo Univ. (Japan). Dept. of Nuclear Engineering; Kulyako, Y.; Samsonov, M.; Miyasoedov, B. [Russian Academy of Sciences, Moscow (Russian Federation). V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI); Moriyama, H. [Kyoto Univ. (Japan). Research Reactor Inst.

2012-07-01

Apparent formation constants of Pu(IV) and Th(IV) with two kinds of humic acids were determined in 0.1 M NaClO{sub 4} at 25 C using a solvent extraction method with thenoyltrifluoroacetone in xylene. The acid dissociation constants of humic acids were also measured by potentiometric titration and used as the degree of dissociation for calculating the formation constants. The effect of solution conditions, such as the pH, the initial metal and humic acid concentrations, and the ionic strength, on the formation constants was examined. The obtained data were compared with the ones in the literature. (orig.)

Is high pressure liquid chromatography an effective screening tool for characterization of molecular defects in hemoglobinopathies?

Directory of Open Access Journals (Sweden)

Nikhil Moorchung

2013-01-01

Full Text Available Introduction: Hemoglobinopathies constitute entities that are generated by either abnormal hemoglobin or thalassemias. high pressure liquid chromatography (HPLC is one of the best methods for screening and detection of various hemoglobinopathies but it has intrinsic interpretive problems. The study was designed to evaluate the different mutations seen in cases of hemoglobinopathies and compare the same with screening tests. Materials and Methods: 68 patients of hemoglobinopathies were screened by HPLC. Mutation studies in the beta globin gene was performed using the polymerase chain reaction (PCR-based allele-specific Amplification Refractory Mutation System (ARMS. Molecular analysis for the sickle cell mutation was done by standard methods. Results: The IVS 1/5 mutation was the commonest mutation seen and it was seen in 26 (38.23% of the cases. This was followed by the IVS 1/1, codon 41/42, codon 8/9, del 22 mutation, codon 15 mutation and the -619 bp deletion. No mutation was seen in eight cases. There was a 100% concordance between the sickle cell trait as diagnosed by HPLC and genetic testing. Discussion and Conclusion: Our study underlies the importance of molecular testing in all cases of hemoglobinopathies. Although HPLC is a useful screening tool, molecular testing is very useful in accurately diagnosing the mutations. Molecular testing is especially applicable in cases with an abnormal hemoglobin (HbD, HbE and HbS because there may be a concomitant inheritance of a beta thalassemia mutation. Molecular testing is the gold standard when it comes to the diagnosis of hemoglobinopathies.

Mandelazo I as a reagent for Zr(IV) determination

International Nuclear Information System (INIS)

Rakha, T.H.; Filip, P.; Stefan, N.

1984-01-01

A spectrometric study of the reaction of the Zr(IV) ions with Mandelazo I was carried out. Absorption spectra revealed that the maximum absorption of the zirconium compound appears at a wavelength (316 nm) different from the maxima of the reagent (253 and 390 nm). Beer-Lambert law is followed for zirconium concentrations of the order of 8.8 x 10 -5 M (i.e. 8 μg Zr(IV)/mL). Possible interferences of ions such as Be(II), Cu(II), Zn(II), Al(III), Th(IV), U(VI), Mn(II), Fe(III), Co(II) and Ni(II) were investigated in connection with some masking agents such as SO 4 2- and C 2 O 4 2- . Also, the solid state Zr(IV)- Mandelazo I compound was prepared and characterized by nitrogen and thermogravimetric analyses

[Mucolipidoses type IV in a patient with mapuche ancestry].

Science.gov (United States)

Hernández Ch, Marta; Méndez C, José Ignacio; Concha G, María José; Huete L, Isidro; González B, Sergio; Durán S, Gloria P

2008-07-01

We report a 7 year-old girl with mapuche ancestors, diagnosed as a cerebral palsy since infancy and on active rehabilitation. She acquired motor and cognitive skills at 3 years of age. At 5 years of age, a slow neurological deterioration started, associated to visual impairment. Optic atrophy was added to the typical neurological exam of ataxic cerebral palsy and the diagnosis was re-considered. Neuroimaging showed a slow and progressive atrophy of intracerebral structures and ultramicroscopy revealed intracytoplasmatic inclusions in conjunctiva and skin, compatible with mucolipidoses type IV (ML-IV). ML-IV must be included in the differential diagnosis of cerebral palsy associated with loss of acquired skills and progressive visual impairment. Electron microscopy of skin or conjunctiva is a useful diagnostic test. Suspicion of ML-IV must not be restricted to Ashkenazi Jewish population.

Peroxidasin-mediated crosslinking of collagen IV is independent of NADPH oxidases

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Gábor Sirokmány

2018-06-01

Full Text Available Collagen IV is a major component of the basement membrane in epithelial tissues. The NC1 domains of collagen IV protomers are covalently linked together through sulfilimine bonds, the formation of which is catalyzed by peroxidasin. Although hydrogen peroxide is essential for this reaction, the exact source of the oxidant remains elusive. Members of the NOX/DUOX NADPH oxidase family are specifically devoted to the production of superoxide and hydrogen peroxide. Our aim in this study was to find out if NADPH oxidases contribute in vivo to the formation of collagen IV sulfilimine crosslinks. We used multiple genetically modified in vivo model systems to provide a detailed assessment of this question. Our data indicate that in various peroxidasin-expressing tissues sulfilimine crosslinks between the NC1 domains of collagen IV can be readily detected in the absence of functioning NADPH oxidases. We also analyzed how subatmospheric oxygen levels influence the collagen IV network in collagen-producing cultured cells with rapid matrix turnover. We showed that collagen IV crosslinks remain intact even under strongly hypoxic conditions. Our hypothesis is that during collagen IV network formation PXDN cooperates with a NOX/DUOX-independent H2O2 source that is functional also at very low ambient oxygen levels. Keywords: Peroxidasin, NADPH oxidase, Hydrogen peroxide, Collagen IV, Sulfilimine

Generation of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides during the enzymatic hydrolysis of tropical banded cricket (Gryllodes sigillatus) proteins.

Science.gov (United States)

Nongonierma, Alice B; Lamoureux, Candice; FitzGerald, Richard J

2018-01-24

Tropical banded crickets (Gryllodes sigillatus) were studied for their ability to yield hydrolysates with dipeptidyl peptidase IV (DPP-IV) inhibitory properties. A cricket protein isolate (CPI) was prepared following extraction of the water soluble proteins from G. sigillatus powder (CP). The extraction yield and purity were 20.90 ± 0.35% and 57.0 ± 2.23%, respectively. Endogenous proteinase activities were detected in the CP, which were linked to the significant protein breakdown seen in this sample. Fifteen CPI hydrolysates (H1-H15) were generated with Protamex™ using a design of experiments (DOE) approach combining three parameters, temperature (40, 50 and 60 °C), enzyme to substrate ratio (E : S, 0.50, 1.25 and 2.00% (w/w)) and hydrolysis time (60, 150 and 240 min). The DPP-IV half maximal inhibitory concentrations (IC 50 ) of the CPI hydrolysates ranged from 0.40 ± 0.03/0.40 ± 0.02 (H2/H3) to 1.01 ± 0.07 mg mL -1 (H7). Following simulated gastrointestinal digestion (SGID), the DPP-IV IC 50 of CPI decreased (>3.57 vs. 0.78 ± 0.04 mg mL -1 ) while that of H5 increased (0.47 ± 0.03 vs. 0.71 ± 0.06 mg mL -1 ). This study has demonstrated for the first time that G. sigillatus protein hydrolysates are able to inhibit DPP-IV. The study of these hydrolysates in vivo is needed to evaluate their potential role in glycaemic management.

The adsorption of 117Snm(IV)-EDTMP on collagen

International Nuclear Information System (INIS)

Yang Yuqing; Luo Shunzhong; Pu Manfei; Bing Wenzeng; He Jiaheng; Wang Guanquan

2002-01-01

The adsorption and desorption characteristics of 117 Sn m (IV)-EDTMP on collage are studied, and compared with that on HA. The results show that the effects of pH and temperature on adsorption of 117 Sn m (IV)-EDTMP on collagen are similar to those on HA, and that the adsorption equilibrium and adsorption model of 117 Sn m (IV)-EDTMP on collagen are completely different from those on HA; 117 Sm m -EDTMP absorbed on collagen are extremely stable and almost could not be desorbed with normal saline or EDTMP

Transmission of endemic ST22-MRSA-IV on four acute hospital wards investigated using a combination of spa, dru and pulsed-field gel electrophoresis typing.

LENUS (Irish Health Repository)

Creamer, E

2012-11-01

The transmission of meticillin-resistant Staphylococcus aureus (MRSA) between individual patients is difficult to track in institutions where MRSA is endemic. We investigated the transmission of MRSA where ST22-MRSA-IV is endemic on four wards using demographic data, patient and environmental screening, and molecular typing of isolates. A total of 939 patients were screened, 636 within 72 h of admission (on admission) and 303 >72 h after admission, and 1,252 environmental samples were obtained. Isolates were typed by spa, dru and pulsed-field gel electrophoresis (PFGE) typing. A composite dendrogram generated from the three sets of typing data was used to divide isolates into \\'dendrogram groups\\' (DGs). Ten percent of patients (92\\/939) were MRSA-positive; 7 % (44\\/636) on admission and 16 % (48\\/303) >72 h after admission (p = 0.0007). MRSA was recovered from 5 % of environmental specimens (65\\/1,252). Most isolates from patients (97 %, 85\\/88) and the environment (97 %, 63\\/65) exhibited the ST22-MRSA-IV genotype. Four DGs (DG1, DG4, DG16 and DG17) accounted for 58 % of ST22-MRSA-IV isolates from patients. Epidemiological evidence suggested cross-transmission among 44\\/92 patients (48 %) but molecular typing confirmed probable cross-transmission in only 11 instances (13 %, 11\\/88), with the majority of cross-transmission (64 %; 7\\/11) occurring on one ward. In the setting of highly clonal endemic MRSA, the combination of local epidemiology, PFGE, spa and dru typing provided valuable insights into MRSA transmission.

Amine and Titanium (IV Chloride, Boron (III Chloride or Zirconium (IV Chloride-Promoted Baylis-Hillman Reactions

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Shi-Cong Cui

2001-10-01

Full Text Available The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV chloride, boron (III chloride or zirconium (IV chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC, then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.

IVS contribution to the next ITRF

Science.gov (United States)

Bachmann, Sabine; Messerschmitt, Linda; Thaller, Daniela

2015-04-01

Generating the contribution of the International VLBI Service (IVS) to the next ITRF (ITRF2013 or ITRF2014) was the main task of the IVS Combination Center at the Federal Agency for Cartography and Geodesy (BKG, Germany) in 2014. Starting with the ITRF2005, the IVS contribution to the ITRF is an intra-technique combined solution using multiple individual contributions from different institutions. For the upcoming ITRF ten international institutions submitted data files for a combined solution. The data files contain 24h VLBI sessions from the late 1970s until the end of 2014 in SINEX file format containing datum free normal equations with station coordinates and Earth Orientation Parameters (EOP). All contributions have to meet the IVS standards for ITRF contribution in order to guarantee a consistent combined solution. In the course of the generation of the intra-technique combined solution, station coordinate time series for each station as well as a Terrestrial Reference Frame based on the contributed VLBI data (VTRF) were generated and analyzed. Preliminary results using data until the end of 2013 show a scaling factor of -0.47 ppb resulting from a 7-parameter Helmert transformation of the VTRF w.r.t. ITRF2008, which is comparable to the scaling factor that was determined in the precedent ITRF generation. An internal comparison of the EOPs between the combined solution and the individual contributions as well as external comparisons of the EOP series were carried out in order to assure a consistent quality of the EOPs. The data analyses, the combination procedure and results of the combined solution for station coordinates and EOP will be presented.

Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus

Energy Technology Data Exchange (ETDEWEB)

Carr, Stephen B., E-mail: bmbsbc@bmb.leeds.ac.uk [Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom); Makris, George [Omega Mediation Hellas Ltd, Clinical and Pharma Consulting, 11525 N. Psychiko, Athens (Greece); Phillips, Simon E. V.; Thomas, Christopher D. [Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom)

2006-11-01

The crystallization and data collection of topoisomerase IV from S. aureus is described. Phasing by molecular replacement proved difficult owing to the presence of translational NCS and strategies used to overcome this are discussed. DNA topoisomerase IV removes undesirable topological features from DNA molecules in order to help maintain chromosome stability. Two constructs of 56 and 59 kDa spanning the DNA-cleavage domain of the A subunit of topoisomerase IV from Staphylococcus aureus (termed GrlA56 and GrlA59) have been crystallized. Crystals were grown at 291 K using the sitting-drop vapour-diffusion technique with PEG 3350 as a precipitant. Preliminary X-ray analysis revealed that GrlA56 crystals belong to space group P2{sub 1}, diffract to a resolution of 2.9 Å and possess unit-cell parameters a = 83.6, b = 171.5, c = 87.8 Å, β = 90.1°, while crystals of GrlA59 belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 41.5, b = 171.89, c = 87.9 Å. These crystals diffract to a resolution of 2.8 Å. This is the first report of the crystallization and preliminary X-ray analysis of the DNA-cleavage domain of a topoisomerase IV from a Gram-positive organism.

An Antarctic hypotrichous ciliate, Parasterkiella thompsoni (Foissner) nov. gen., nov. comb., recorded in Argentinean peat-bogs: morphology, morphogenesis, and molecular phylogeny.

Science.gov (United States)

Küppers, Gabriela Cristina; Paiva, Thiago da Silva; Borges, Bárbara do Nascimento; Harada, Maria Lúcia; Garraza, Gabriela González; Mataloni, Gabriela

2011-05-01

The ciliate Parasterkiella thompsoni (Foissner, 1996) nov. gen., nov. comb. was originally described from Antarctica. In the present study, we report the morphology, morphogenesis during cell division, and molecular phylogeny inferred from the 18S-rDNA sequence of a population isolated from the Rancho Hambre peat bog, Tierra del Fuego Province (Argentina). The study is based on live and protargol-impregnated specimens. Molecular phylogeny was inferred from trees constructed by means of the maximum parsimony, neighbor joining, and Bayesian analyses. The interphase morphology matches the original description of the species. During the cell division, stomatogenesis begins with the de novo proliferation of two fields of basal bodies, each one left of the postoral ventral cirri and of transverse cirri, which later unify. Primordia IV-VI of the proter develop from disaggregation of cirrus IV/3, while primordium IV of the opisthe develops from cirrus IV/2 and primordia V and VI from cirrus V/4. Dorsal morphogenesis occurs in the Urosomoida pattern-that is, the fragmentation of kinety 3 is lacking. Three macronuclear nodules are generated before cytokinesis. Phylogenetic analyses consistently placed P. thompsoni within the stylonychines. New data on the morphogenesis of the dorsal ciliature justifies the transference of Sterkiella thompsoni to a new genus Parasterkiella. Copyright © 2011 Elsevier GmbH. All rights reserved.

Gen IV. Technical and economical aspects

International Nuclear Information System (INIS)

Kaluzny, Y.; Legee, F.

2010-01-01

In this presentation author deals with development of nuclear reactor type of Generation IV. He concluded that: - Nuclear energy is competitive with regards to the other generation sources; Its competitiveness also increases with CO 2 cost. Considering the nuclear cost breakdown of LWR reactors, it turns out that the uranium is currently not in the range of a threshold for FBR deployment; - The global balance of uranium supply and demand and also innovation required to fulfil GEN IV objectives would probably imply the emergence of fast reactor competitiveness after the turn of the mid-century; - We shall need fast reactors in the coming decade.

Pilin Processing Follows a Different Temporal Route than That of Archaellins in Methanococcus maripaludis

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Divya B. Nair

2015-01-01

Full Text Available Methanococcus maripaludis has two different surface appendages: type IV-like pili and archaella. Both structures are believed to be assembled using a bacterial type IV pilus mechanism. Each structure is composed of multiple subunits, either pilins or archaellins. Both pilins and archaellins are made initially as preproteins with type IV pilin-like signal peptides, which must be removed by a prepilin peptidase-like enzyme. This enzyme is FlaK for archaellins and EppA for pilins. In addition, both pilins and archaellins are modified with N-linked glycans. The archaellins possess an N-linked tetrasaccharide while the pilins have a pentasaccharide which consists of the archaellin tetrasaccharide but with an additional sugar, an unidentified hexose, attached to the linking sugar. In this report, we show that archaellins can be processed by FlaK in the absence of N-glycosylation and N-glycosylation can occur on archaellins that still retain their signal peptides. In contrast, pilins are not glycosylated unless they have been acted on by EppA to have the signal peptide removed. However, EppA can still remove signal peptides from non-glycosylated pilins. These findings indicate that there is a difference in the order of the posttranslational modifications of pilins and archaellins even though both are type IV pilin-like proteins.

Removal of thorium(IV) from aqueous solutions by natural sepiolite

Energy Technology Data Exchange (ETDEWEB)

Erden, Kadriye Esen [Pamukkale Univ., Denizli (Turkey). Dept. of Electricity and Energy; Donat, Ramazan [Pamukkale Univ., Denizli (Turkey). Dept. of Chemistry

2017-06-01

Natural sepiolite has been tested as a potential sorbent for the removal of Th(IV) from aqueous solutions by batch technique. Effects of various parameters on the adsorption process have been investigated. Under optimum conditions, Th(IV) was adsorbed with high adsorption efficiency. The results indicated that sorption of Th(IV) on sepiolite was strongly affected by pH values and temperature. The adsorption patterns of thorium on the sepiolite adsorbent followed the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The thermodynamic data (ΔH , ΔS , ΔG ) are calculated from the temperature-dependent sorption isotherms. The results suggest that sorption process of Th(IV) on sepiolite is spontaneous and endothermic.

Effect of HCl Concentration on the Oxidation of LIX 63 and the Subsequent Separation of Pd(II), Pt(IV), Ir(IV) and Rh(III) by Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thi Hong; Lee, Man Seung [Mokpo National University, Jeollanamdo (Korea, Republic of)

2016-10-15

During the selective extraction of Pd(II) by LIX 63 from 6 M HCl solutions containing platinum group metals, an oxidation-reduction reaction occurs between the LIX 63 and Ir(IV). Since the reduced Ir(III) cannot be extracted by solvating and amine extractants, the oxidation-reduction reaction has a significant effect on the separation of Pt(IV), Ir(IV) and Rh(III). Therefore, the effect of HCl concentration on the reduction of Ir(IV) during the extraction with LIX 63 was investigated at 3 and 6 M HCl solutions. The extraction behavior of Iridium by Aliquat 336 from the Pd(II) free raffinate showed that the percentage of iridium extraction rapidly decreased when HCl concentration was increased from 3 to 6 M, indicating that more Ir(IV) was reduced to Ir(III). Extraction schemes for the separation of Pt(IV), iridium and Rh(III) by Aliquat 336 from 3 and 6 M HCl solutions were investigated.

The lytic transglycosylase MltB connects membrane homeostasis and in vivo fitness of Acinetobacter baumannii.

Science.gov (United States)

Crépin, Sébastien; Ottosen, Elizabeth N; Peters, Katharina; Smith, Sara N; Himpsl, Stephanie D; Vollmer, Waldemar; Mobley, Harry L T

2018-06-08

Acinetobacter baumannii has emerged as a leading nosocomial pathogen, infecting a wide range of anatomic sites including the respiratory tract and the bloodstream. In addition to being multi-drug resistant, little is known about the molecular basis of A. baumannii pathogenesis. To better understand A. baumannii virulence, a combination of a transposon-sequencing (TraDIS) screen and the neutropenic mouse model of bacteremia was used to identify the full set of fitness genes required during bloodstream infection. The lytic transglycosylase MltB was identified as a critical fitness factor. MltB cleaves the MurNAc-GlcNAc bond of peptidoglycan, which leads to cell wall remodeling. Here we show that MltB is part of a complex network connecting resistance to stresses, membrane homeostasis, biogenesis of pili and in vivo fitness. Indeed, inactivation of mltB not only impaired resistance to serum complement, cationic antimicrobial peptides and oxygen species, but also altered the cell envelope integrity, activated the envelope stress response, drastically reduced the number of pili at the cell surface and finally, significantly decreased colonization of both the bloodstream and the respiratory tract. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

Crystal structures of lazulite-type oxidephosphates TiIIITiIV3O3(PO4)3 and MIII4TiIV27O24(PO4)24 (MIII=Ti, Cr, Fe)

International Nuclear Information System (INIS)

Schoeneborn, M.; Glaum, R.; Reinauer, F.

2008-01-01

Single crystals of the oxidephosphates Ti III Ti IV 3 O 3 (PO 4 ) 3 (black), Cr III 4 Ti IV 27 O 24 (PO 4 ) 24 (red-brown, transparent), and Fe III 4 Ti IV 27 O 24 (PO 4 ) 24 (brown) with edge-lengths up to 0.3 mm were grown by chemical vapour transport. The crystal structures of these orthorhombic members (space group F2dd ) of the lazulite/lipscombite structure family were refined from single-crystal data [Ti III Ti IV 3 O 3 (PO 4 ) 3 : Z=24, a=7.3261(9) A, b=22.166(5) A, c=39.239(8) A, R 1 =0.029, wR 2 =0.084, 6055 independent reflections, 301 variables; Cr III 4 Ti IV 27 O 24 (PO 4 ) 24 : Z=1, a=7.419(3) A, b=21.640(5) A, c=13.057(4) A, R 1 =0.037, wR 2 =0.097, 1524 independent reflections, 111 variables; Fe III 4 Ti IV 27 O 24 (PO 4 ) 24 : Z=1, a=7.4001(9) A, b=21.7503(2) A, c=12.775(3) A, R 1 =0.049, wR 2 =0.140, 1240 independent reflections, 112 variables). For Ti III Ti IV O 3 (PO 4 ) 3 a well-ordered structure built from dimers [Ti III,IV 2 O 9 ] and [Ti IV,IV 2 O 9 ] and phosphate tetrahedra is found. The metal sites in the crystal structures of Cr 4 Ti 27 O 24 (PO 4 ) 24 and Fe 4 Ti 27 O 24 (PO 4 ) 24 , consisting of dimers [M III Ti IV O 9 ] and [Ti IV,IV 2 O 9 ], monomeric [Ti IV O 6 ] octahedra, and phosphate tetrahedra, are heavily disordered. Site disorder, leading to partial occupancy of all octahedral voids of the parent lipscombite/lazulite structure, as well as splitting of the metal positions is observed. According to Guinier photographs Ti III 4 Ti IV 27 O 24 (PO 4 ) 24 (a=7.418(2) A, b=21.933(6) A, c=12.948(7) A) is isotypic to the oxidephosphates M III 4 Ti IV 27 O 24 (PO 4 ) 24 (M III : Cr, Fe). The UV/vis spectrum of Cr 4 Ti 27 O 24 (PO 4 ) 24 reveals a rather small ligand-field splitting Δ o =14,370 cm -1 and a very low nephelauxetic ratio β=0.72 for the chromophores [Cr III O 6 ] within the dimers [Cr III Ti IV O 9 ]. - Graphical abstract: Single crystals of the oxidephosphates Ti III Ti IV 3 O 3 (PO 4 ) 3 (black), Cr III 4 Ti IV 27 O

Synthesis, spectral, DFT modeling, cytotoxicity and microbial studies of novel Zr(IV), Ce(IV) and U(VI) piroxicam complexes

Science.gov (United States)

El-Shwiniy, Walaa H.; Zordok, Wael A.

2018-06-01

The Zr(IV), Ce(IV) and U(VI) piroxicam anti-inflammatory drug complexes were prepared and characterized using elemental analyses, conductance, IR, UV-Vis, magnetic moment, IHNMR and thermal analysis. The ratio of metal: Pir is found to be 1:2 in all complexes estimated by using molar ratio method. The conductance data reveal that Zr(IV) and U(VI) chelates are non-electrolytes except Ce(IV) complex is electrolyte. Infrared spectroscopic confirm that the Pir behaves as a bidentate ligand co-ordinated to the metal ions via the oxygen and nitrogen atoms of ν(Cdbnd O)carbonyl and ν(Cdbnd N)pyridyl, respectively. The kinetic parameters of thermogravimetric and its differential, such as activation energy, entropy of activation, enthalpy of activation, and Gibbs free energy evaluated using Coats-Redfern and Horowitz-Metzger equations for Pir and complexes. The geometry of the piroxicam drug in the Free State differs significantly from that in the metal complex. In the time of metal ion-drug bond formation the drug switches-on from the closed structure (equilibrium geometry) to the open one. The antimicrobial tests were assessed towards some types of bacteria and fungi. The in vitro cell cytotoxicity of the complexes in comparison with Pir against colon carcinoma (HCT-116) cell line was measured. Optimized geometrical structure of piroxicam ligand by using DFT calculations.

X-ray spectroscopic characterization of Co(IV) and metal–metal interactions in Co₄O₄: Electronic structure contributions to the formation of high-valent states relevant to the oxygen evolution reaction

Energy Technology Data Exchange (ETDEWEB)

Hadt, Ryan G.; Hayes, Dugan; Brodsky, Casey N.; Ullman, Andrew M.; Casa, Diego M.; Upton, Mary H.; Nocera, Daniel G; Chen, Lin X.

2016-08-12

In this paper, the formation of high-valent states is a key factor in making highly active transition metal-based catalysts of the oxygen-evolving reaction (OER). These high oxidation states will be strongly influenced by the local geometric and electronic structures of the metal ion, which is difficult to study due to spectroscopically active and complex backgrounds, short lifetimes, and limited concentrations. Here, we use a wide range of complementary X-ray spectroscopies coupled to DFT calculations to study Co₄O₄ cubanes, which provide insight into the high-valent Co(IV) centers responsible for the activity of molecular and heterogeneous OER catalysts. The combination of X-ray absorption and 1s3p resonant inelastic X-ray scattering (Kβ RIXS) allow Co(IV) to be isolated and studied against a spectroscopically active Co(III) background. Co K- and L-edge X-ray absorption data allow for a detailed characterization of the 3d-manifold of effectively localized Co(IV) centers and provide a direct handle on the ligand field environment and covalency of the t_2g-based redox active molecular orbital. Kβ RIXS is also shown to provide a powerful probe of Co(IV), and specific spectral features are sensitive to the degree of oxo-mediated metal-metal coupling across Co₄O₄. Guided by the data, calculations show electron-hole delocalization can actually oppose Co(IV) formation. Computational extension of Co₄O₄ to CoM₃O₄ structures (M = redox-inactive metal) defines electronic structure contri-butions to Co(IV) formation. Redox activity is shown to be linearly related to covalency, and M(III) oxo inductive effects on Co(IV) oxo bonding can tune the covalency of high-valent sites over a large range and thereby tune E⁰ over hundreds of mVs.

Degradation of type IV collagen by neoplastic human skin fibroblasts

International Nuclear Information System (INIS)

Sheela, S.; Barrett, J.C.

1985-01-01

An assay for the degradation of type IV (basement membrane) collagen was developed as a biochemical marker for neoplastic cells from chemically transformed human skin fibroblasts. Type IV collagen was isolated from basement membrane of Syrian hamster lung and type I collagen was isolated from rat tails; the collagens were radioactively labelled by reductive alkylation. The abilities of normal (KD) and chemically transformed (Hut-11A) human skin fibroblasts to degrade the collagens were studied. A cell-associated assay was performed by growing either normal or transformed cells in the presence of radioactively labelled type IV collagen and measuring the released soluble peptides in the medium. This assay also demonstrated that KD cells failed to synthesize an activity capable of degrading type IV collagen whereas Hut-11A cells degraded type IV collagen in a linear manner for up to 4 h. Human serum at very low concentrations, EDTA and L-cysteine inhibited the enzyme activity, whereas protease inhibitors like phenylmethyl sulfonyl fluoride, N-ethyl maleimide or soybean trypsin inhibitor did not inhibit the enzyme from Hut-11A cells. These results suggest that the ability to degrade specifically type IV collagen may be an important marker for neoplastic human fibroblasts and supports a role for this collagenase in tumor cell invasion

Dibutylammonium bis(hydrogen methylphosphonato-κOtriphenylstannate(IV

Directory of Open Access Journals (Sweden)

Tidiane Diop

2012-10-01

Full Text Available The asymmetric unit of the title organotin salt, (C8H20N[Sn(C6H53(CH4O3P2], contains two dibutylammonium cations and two stannate(IV anions consisting each of two monodentately bonding methyl hydrogenphosphate groups attached to an Sn(C6H5 unit. The overall coordination environment of the two SnIV atoms is trigonal–bipyramidal defined by three phenyl C atoms in equatorial positions and two methyl hydrogenphosphate O atoms at the apical sites. In the crystal, the stannate(IV anions are linked to each other via pairs of short O—H...O hydrogen bonds, leading to an infinite chain extending parallel to the b-axis direction. Neighbouring chains are linked by N—H...O hydrogen bonds involving the butylammonium cations, giving a two-dimensional structure parallel to the ab plane. The crystal under investigation was found to be twinned by reticular merohedry with twin fractions of 0.5342 (7:0.4658 (7.

Studies on Th(IV) and Zr(IV) complexes of oxygen donor ligands

International Nuclear Information System (INIS)

Agarwal, R.K.; Srivastava, M.; Srivastava, A.K.

1981-01-01

In recent years a large number of complexes of amine N-oxides with a wide variety of metal salts have been isolated and characterized. Less attention has been paid to the aromatic amine N-oxides complexes with Th(IV) thiocyanate. In the present communication studies are reported on Th(IV) thiocyanate complexes of pyridine N-oxide (PyO), quinoline N-oxide (QO), isoquinoline N-oxide (IsqO), 2-picoline N-oxide (2-picO), 3-picoline N-oxide (3-picO) and 4-picoline N-oxide (4-picO) and comparisons are made with the existing complexes of 2,6-lutidine N-oxide (LNO), 2, 2'bipyridine N-N'-dioxide (BipyO 2 ), mono N-oxides of 2,2'-bipyridine (BipyNO) and 1,10-phenanthroline (PhenNO) and 1, 10-phenanthroline N-N'-dioxide (PhenO 2 ). The analytical data correspond to the composition Th(NCS) 4 .4L. The molar conductance of all the complexes in nitrobenzene in the range 2.5 to 4.5 Ω -1 cm 2 mol -1 indicate them to be non-electrolytes. The results of IR spectroscopy and thermogravimetry are given and discussed. (author)

Synthesis and Molecular Structure of a Novel Compound Containing a Carbonate-Bridged Hexacalcium Cluster Cation Assembled on a Trimeric Trititanium(IV)-Substituted Wells-Dawson Polyoxometalate.

Science.gov (United States)

Hoshino, Takahiro; Isobe, Rina; Kaneko, Takuya; Matsuki, Yusuke; Nomiya, Kenji

2017-08-21

A novel compound containing a hexacalcium cluster cation, one carbonate anion, and one calcium cation assembled on a trimeric trititanium(IV)-substituted Wells-Dawson polyoxometalate (POM), [{Ca 6 (CO 3 )(μ 3 -OH)(OH 2 ) 18 }(P 2 W 15 Ti 3 O 61 ) 3 Ca(OH 2 ) 3 ] 19- (Ca 7 Ti 9 Trimer), was obtained as the Na 7 Ca 6 salt (NaCa-Ca 7 Ti 9 Trimer) by the reaction of calcium chloride with the monomeric trititanium(IV)-substituted Wells-Dawson POM species "[P 2 W 15 Ti 3 O 59 (OH) 3 ] 9- " (Ti 3 Monomer). Ti 3 Monomer was generated in situ under basic conditions from the separately prepared tetrameric species with bridging Ti(OH 2 ) 3 groups and an encapsulated Cl - ion, [{P 2 W 15 Ti 3 O 59 (OH) 3 } 4 {μ 3 -Ti(H 2 O) 3 } 4 Cl] 21- (Ti 16 Tetramer). The Na 7 Ca 6 salt of Ca 7 Ti 9 Trimer was characterized by complete elemental analysis, thermogravimetric (TG) and differential thermal analyses (DTA), FTIR, single-crystal X-ray structure analysis, and solution 183 W and 31 P NMR spectroscopy. X-ray crystallography revealed that the [Ca 6 (CO 3 )(μ 3 -OH)(OH 2 ) 18 ] 9+ cluster cation was composed of six calcium cations linked by one μ 6 -carbonato anion and one μ 3 -OH - anion. The cluster cation was assembled, together with one calcium ion, on a trimeric species composed of three tri-Ti(IV)-substituted Wells-Dawson subunits linked by Ti-O-Ti bonds. Ca 7 Ti 9 Trimer is an unprecedented POM species containing an alkaline-earth-metal cluster cation and is the first example of alkaline-earth-metal ions clustered around a titanium(IV)-substituted POM.

Perehdyttäminen Nummenselän päiväkodissa

OpenAIRE

Mustiala, Hanne

2013-01-01

TIIVISTELMÄ Mustiala, Hanne. Perehdyttäminen Nummenselän päiväkodissa. Diak, syksy 2013, 71s., 3 liitettä. Diakonia-ammattikorkeakoulu, Sosiaalialan koulutusohjelma, Sosionomi (AMK) + lastentarhanopettajan virkakelpoisuus. Toiminnallisen opinnäytetyöni tavoitteena oli tuottaa perehdyttämismateriaali Nummenselän päiväkodille. Päiväkoti on uusi päivähoidon toimintayksikkö Vihdissä. Tähän asti uuden työntekijän perehdyttämisessä on käytetty Vihdin kunnan yhteistä perehdyttämis...

Structure and magnetism in novel group IV element-based magnetic materials

Energy Technology Data Exchange (ETDEWEB)

Tsui, Frank [Univ. of North Carolina, Chapel Hill, NC (United States)

2013-08-14

The project is to investigate structure, magnetism and spin dependent states of novel group IV element-based magnetic thin films and heterostructures as a function of composition and epitaxial constraints. The materials systems of interest are Si-compatible epitaxial films and heterostructures of Si/Ge-based magnetic ternary alloys grown by non-equilibrium molecular beam epitaxy (MBE) techniques, specifically doped magnetic semiconductors (DMS) and half-metallic Heusler alloys. Systematic structural, chemical, magnetic, and electrical measurements are carried out, using x-ray microbeam techniques, magnetotunneling spectroscopy and microscopy, and magnetotransport. The work is aimed at elucidating the nature and interplay between structure, chemical order, magnetism, and spin-dependent states in these novel materials, at developing materials and techniques to realize and control fully spin polarized states, and at exploring fundamental processes that stabilize the epitaxial magnetic nanostructures and control the electronic and magnetic states in these complex materials. Combinatorial approach provides the means for the systematic studies, and the complex nature of the work necessitates this approach.

Ion exchange characteristics of cerium (IV) and Tin(IV) antimonates and their use in rad waste treatment

Energy Technology Data Exchange (ETDEWEB)

Elnaggar, I M; Abdel Hamid, M M; Elabsy, M A; Aly, H F [Hot lab. centre, atomic energy authority, Cairo, (Egypt)

1995-10-01

Cerium (IV) and Tin(IV) antimonates cation exchangers have been synthesized. The products were characterized by powdered X-ray diffraction, thermal analysis and infrared spectrometry. The data of the distribution coefficients showed that the selectivity decreased in the order Eu{sup 3+}>Co{sup 2+}>Sr{sup 2+}>Cs{sup +} for both materials. Besides, the drying temperature of the matrices have a profound effect on their ion exchange capacities. Moreover, the obtained results of the effect of gamma radiation on the ion exchange behaviour of the samples showed that a slight decrease of the capacity and the distribution coefficient values with increasing the absorbed dose. 2 figs., 4 tabs.

Synthesis and spectral properties of axially substituted zirconium(IV) and hafnium(IV) water soluble phthalocyanines in solutions

International Nuclear Information System (INIS)

Gerasymchuk, Y.S.; Volkov, S.V.; Chernii, V.Ya.; Tomachynski, L.A.; Radzki, St.

2004-01-01

Methods of synthesis of novel water soluble axially substituted Zr(IV) and Hf(IV) phthalocyanines with gallic, 5-sulfosalicyllic, oxalic acids, and methyl ester of gallic acid as axial ligands coordinated to the central atom metal of phthalocyanine are presented. The absorption spectra of complex solutions in various solvents were characterized. The dependence of the spectral red shift from Reichardt's empirical polarity parameter is described. The deviation from the linearity of Beer-Bouguer-Lambert law was investigated for the range of concentration 5x10 -6 to 10x10 -5 M. Fluorescent properties of axially substituted phthalocyaninato metal complexes in DMSO solutions were investigated

Formation, characterization, and stability of plutonium (IV) colloid

International Nuclear Information System (INIS)

Hobart, D.E.; Morris, D.E.; Palmer, P.D.; Newton, T.W.

1989-01-01

Plutonium is expected to be a major component of the waste element package in any high-level nuclear waste repository. Plutonium(IV) is known to form colloids under chemical conditions similar to those found in typical groundwaters. In the event of a breach of a repository, these colloids represent a source of radionuclide transport to the far-field environment, in parallel with the transport of dissolved waste element species. In addition, the colloids may decompose or disaggregate into soluble ionic species. Thus, colloids represent an additional term in determining waste element solubility limits. A thorough characterization of the physical and chemical properties of these colloids under relevant conditions is essential to assess the concentration limits and transport mechanisms for the waste elements at the proposed Yucca Mountain Repository site. This report is concerned primarily with recent results obtained by the Yucca Mountain Project (YMP) Solubility Determination Task pertaining to the characterization of the structural and chemical properties of Pu(IV) colloid. Important results will be presented which provides further evidence that colloidal plutonium(IV) is structurally similar to plutonium dioxide and that colloidal plutonium(IV) is electrochemically reactive. 13 refs., 7 figs

Distinct activities of Bartonella henselae type IV secretion effector proteins modulate capillary-like sprout formation.

Science.gov (United States)

Scheidegger, F; Ellner, Y; Guye, P; Rhomberg, T A; Weber, H; Augustin, H G; Dehio, C

2009-07-01

The zoonotic pathogen Bartonella henselae (Bh) can lead to vasoproliferative tumour lesions in the skin and inner organs known as bacillary angiomatosis and bacillary peliosis. The knowledge on the molecular and cellular mechanisms involved in this pathogen-triggered angiogenic process is confined by the lack of a suitable animal model and a physiologically relevant cell culture model of angiogenesis. Here we employed a three-dimensional in vitro angiogenesis assay of collagen gel-embedded endothelial cell (EC) spheroids to study the angiogenic properties of Bh. Spheroids generated from Bh-infected ECs displayed a high capacity to form sprouts, which represent capillary-like projections into the collagen gel. The VirB/VirD4 type IV secretion system and a subset of its translocated Bartonella effector proteins (Beps) were found to profoundly modulate this Bh-induced sprouting activity. BepA, known to protect ECs from apoptosis, strongly promoted sprout formation. In contrast, BepG, triggering cytoskeletal rearrangements, potently inhibited sprouting. Hence, the here established in vitro model of Bartonella- induced angiogenesis revealed distinct and opposing activities of type IV secretion system effector proteins, which together with a VirB/VirD4-independent effect may control the angiogenic activity of Bh during chronic infection of the vasculature.

Endonuclease IV of Escherichia coli is induced by paraquat

Energy Technology Data Exchange (ETDEWEB)

Chan, E.; Weiss, B.

1987-05-01

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H/sub 2/O/sub 2/ produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, ..gamma.. rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O/sub 2/. The levels of endonuclease IV in uninduced or paraquat-treated cells were unaffected by mutations of oxyR, a H/sub 2/O/sub 2/-inducible gene that governs an oxidative-stress regulon. The results indicate that endonuclease IV is an inducible DNA-repair enzyme and that its induction can be mediated via the production of superoxide radicals.

Endonuclease IV of Escherichia coli is induced by paraquat

International Nuclear Information System (INIS)

Chan, E.; Weiss, B.

1987-01-01

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H 2 O 2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, γ rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O 2 . The levels of endonuclease IV in uninduced or paraquat-treated cells were unaffected by mutations of oxyR, a H 2 O 2 -inducible gene that governs an oxidative-stress regulon. The results indicate that endonuclease IV is an inducible DNA-repair enzyme and that its induction can be mediated via the production of superoxide radicals

Leachables from saline-containing IV bags can alter therapeutic protein properties.

Science.gov (United States)

Chang, Judy Y; Xiao, Nina J; Zhu, Min; Zhang, Jennifer; Hoff, Ed; Russell, Stephen J; Katta, Viswanatham; Shire, Steven J

2010-11-01

To investigate the cause of the observed instability of dulanermin in 100 ml polyolefin (PO) infusion bags containing saline. Diluted dulanermin in IV bags was collected and frozen prior to analysis by size exclusion chromatography. The UV absorption profiles of the IV bag solutions were characterized by using spectrophotometry. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measured the metal content. Leachables from IV bags were identified by LC-UV-high resolution MS/MS analysis. An elevated loss of dulanermin monomers was observed only in 100 ml PO bags. These IV bag solutions have a compound that contains zinc and has absorbance at 320 nm. This compound was identified to be 2-Mercaptobenzothiazole, and its zinc salt and was found to come from the stopper used in the 100 ml PO bags. The manufacturer has subsequently corrected this problem by using non-latex components in the 100 ml PO IV bag. End-users need to be aware that IV bags made from a particular polymer by the same manufacturer may contain components or use a manufacturing process that results in a different product. Analysis of samples after freezing and thawing proved to be useful in identifying potential incompatibility of dulanermin in the IV bags.

Isopeptide bonds of the major pilin protein BcpA influence pilus structure and bundle formation on the surface of Bacillus cereus

Energy Technology Data Exchange (ETDEWEB)

Hendrickx, Antoni P.A.; Poor, Catherine B.; Jureller, Justin E.; Budzik, Jonathan M.; He, Chuan; Schneewind, Olaf (UC)

2012-09-05

Bacillus cereus strains elaborate pili on their surface using a mechanism of sortase-mediated cross-linking of major and minor pilus components. Here we used a combination of electron microscopy and atomic force microscopy to visualize these structures. Pili occur as single, double or higher order assemblies of filaments formed from monomers of the major pilin, BcpA, capped by the minor pilin, BcpB. Previous studies demonstrated that within assembled pili, four domains of BcpA -- CNA{sub 1}, CNA{sub 2}, XNA and CNA{sub 3} -- each acquire intramolecular lysine-asparagine isopeptide bonds formed via catalytic glutamic acid or aspartic acid residues. Here we showed that mutants unable to form the intramolecular isopeptide bonds in the CNA2 or CNA3 domains retain the ability to form pilus bundles. A mutant lacking the CNA{sub 1} isopeptide bond assembled deformed pilin subunits that failed to associate as bundles. X-ray crystallography revealed that the BcpA variant Asp{sup 312}Ala, lacking an aspartyl catalyst, did not generate the isopeptide bond within the jelly-roll structure of XNA. The Asp{sup 312}Ala mutant was also unable to form bundles and promoted the assembly of deformed pili. Thus, structural integrity of the CNA{sub 1} and XNA domains are determinants for the association of pili into higher order bundle structures and determine native pilus structure.

Outerbridge Grade IV Cartilage Lesions in the Hip Identified at Arthroscopy.

Science.gov (United States)

Bhatia, Sanjeev; Nowak, Douglas D; Briggs, Karen K; Patterson, Diana C; Philippon, Marc J

2016-05-01

To determine factors associated with grade IV cartilage defects in the hip in patients undergoing hip arthroscopy with joint pain. Data from consecutive patients who underwent hip arthroscopy performed by a single surgeon over a period of 4 years were included in this study. The study group included 1,097 patients (491 women and 606 men; mean age, 37 years) who underwent hip arthroscopy for pain, had no prior hip surgery, and were aged 18 years or older. Preoperative radiographs, patient demographic characteristics, and operative details were used to identify risk factors for cartilage defects. Grade IV chondral defects were present in 308 of 1,097 hips (28%). Isolated chondral lesions were more frequently observed on the acetabulum (76%) than on the femoral head (24%). Defects of the acetabulum were more commonly anterosuperior (94.7%) and less commonly posterolateral (5.3%). Patients with less than 2 mm of joint space on preoperative radiographs were 8 times more likely to have a grade IV lesion than those with more than 2 mm. Men were more likely than women to have grade IV lesions (35% v 19%, P = .0001); patients with grade IV lesions were older than those without (42 years v 34 years, P = .0001). Hips with grade IV lesions had significantly higher alpha angles than those without (74° v 70°, P = .0001). Patients with grade IV defects reported a longer duration of symptoms than those without (37 months v 27 months, P = .007). Independent risk factors for the presence of grade IV chondral defects were less than 2 mm of joint space, male gender, increasing age, larger alpha angle, and longer duration of symptoms. Grade IV chondral defects in patients undergoing hip arthroscopy were associated with decreased joint space, increased time from symptom onset to arthroscopy, male gender, and larger alpha angles associated with femoroacetabular impingement. Level IV, prognostic case series. Copyright © 2016 Arthroscopy Association of North America. Published by

ADHD Rating Scale-IV: Checklists, Norms, and Clinical Interpretation

Science.gov (United States)

Pappas, Danielle

2006-01-01

This article reviews the "ADHD Rating Scale-IV: Checklist, norms, and clinical interpretation," is a norm-referenced checklist that measures the symptoms of attention deficit/hyperactivity disorder (ADHD) according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric…

Synthesis, structure, and thermal properties of soluble hydrazinium germanium(IV) and tin(IV) selenide salts.

Science.gov (United States)

Mitzi, David B

2005-05-16

The crystal structures of two hydrazinium-based germanium(IV) and tin(IV) selenide salts are determined. (N(2)H(5))(4)Ge(2)Se(6) (1) [I4(1)cd, a = 12.708(1) Angstroms, c = 21.955(2) Angstroms, Z = 8] and (N(2)H(4))(3)(N(2)H(5))(4)Sn(2)Se(6) (2) [P, a = 6.6475(6) Angstroms, b = 9.5474(9) Angstroms, c = 9.8830(10) Angstroms, alpha = 94.110(2) degrees, beta = 99.429(2) degrees, gamma = 104.141(2) degrees, Z = 1] each consist of anionic dimers of edge-sharing metal selenide tetrahedra, M(2)Se(6)(4-) (M = Ge or Sn), separated by hydrazinium cations and, for 2, additional neutral hydrazine molecules. Substantial hydrogen bonding exists among the hydrazine/hydrazinium molecules as well as between the hydrazinium cations and the selenide anions. Whereas the previously reported tin(IV) sulfide system, (N(2)H(5))(4)Sn(2)S(6), decomposes cleanly to microcrystalline SnS(2) when heated to 200 degrees C in an inert atmosphere, higher temperatures (>300 degrees C) are required to dissociate selenium from 1 and 2 for the analogous preparations of single-phase metal selenides. The metal chalcogenide salts are highly soluble in hydrazine, as well as in a variety of amines and DMSO, highlighting the potential usefulness of these compounds as precursors for the solution deposition of the corresponding metal chalcogenide films.

11. IV avati Draakoni galeriis...

Index Scriptorium Estoniae

2005-01-01

Tanel Saare (sünd. 1979) näitus "Gott und huhn episode IV: seed shower". Eksponeeritakse väljavõtteid aktsioonidest aastatel 2000-2004 Turus, Nürnbergis, Berliinis, Lohusalus ja Soulis. Osa aktsioone toimus koos rühmitusega Non Grata

Apolipoprotein A-IV interacts synergistically with melanocortins to reduce food intake.

Science.gov (United States)

Gotoh, Koro; Liu, Min; Benoit, Stephen C; Clegg, Deborah J; Davidson, W Sean; D'Alessio, David; Seeley, Randy J; Tso, Patrick; Woods, Stephen C

2006-01-01

Apolipoprotein (apo) A-IV is an anorexigenic gastrointestinal peptide that is also synthesized in the hypothalamus. The goal of these experiments was to determine whether apo A-IV interacts with the central melanocortin (MC) system in the control of feeding. The third ventricular (i3vt) administration of a subthreshold dose of apo A-IV (0.5 microg) potentiated i3vt MC-induced (metallothionein-II, 0.03 nmol) suppression of 30-min feeding in Long-Evans rats. A subthreshold dose of the MC antagonist (SHU9119, 0.1 nmol, i3vt) completely attenuated the anorectic effect of i3vt apo A-IV (1.5 microg). The i3vt apo A-IV significantly elevated the expression of c-Fos in neurons of the paraventricular nucleus of the hypothalamus, but not in the arcuate nucleus or median eminence. In addition, c-Fos expression was not colocalized with proopiomelanocortin-positive neurons. These data support a synergistic interaction between apo A-IV and melanocortins that reduces food intake by acting downstream of the arcuate.

Separation of Th(IV) and U(VI) by extraction chromatography

International Nuclear Information System (INIS)

Nadkarni, M.N.; Mayankutty, P.C.; Pillai, N.S.

1984-01-01

Application of extraction chromatography to the analytical separation of Th(IV) and U(VI) has been investigated. The stationary phase was a macroporous resin Amberlite XE-270 impregnated with undiluted tri-n-butylphosphate (TBP) and the mobile phase was either 5.0M HNO 3 or 6M HCl. Separation of traces of Th(IV) from large quantities of U(VI) was achieved on a laboratory column by elution of the absorbed Th(IV) with 6M HCl. (author)

Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

Directory of Open Access Journals (Sweden)

Hsu Hui-Chi

2011-04-01

Full Text Available Abstract Background Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization. Methods Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied. Results We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was

Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

International Nuclear Information System (INIS)

Kao, Kuo-Jang; Chang, Kai-Ming; Hsu, Hui-Chi; Huang, Andrew T

2011-01-01

Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization. Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied. We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was consistent with a unique subset of luminal A intrinsic

Technical data summary: Uranium(IV) production using a large scale electrochemical cell

International Nuclear Information System (INIS)

Hsu, T.C.

1984-05-01

This Technical Data Summary outlines an electrochemical process to produce U(IV), in the form of uranous nitrate, from U(VI), as uranyl nitrate. U(IV) with hydrazine could then be used as an alternative plutonium reductant to substantially reduce the waste volume from the Purex solvent extraction process. This TDS is divided into three parts. The first part (Chapters I to IV) generally describes the electrochemical production of U(IV). The second part (Chapters V to VII) describes a pilot scale U(IV) production facility that was constructed and operated at an engineering semiworks area of SRP, referred to as TNX. The lst part (Chapter VIII) describes a preliminary design for a full-scale facility that would meet the projected need for U(IV) as a reductant in SRP's separations processes. The preliminary design was described in a Basic Data Summary for the U(IV) production facility, and a Venture Guidance Appraisal (VGA) was prepared from the Basic Data Summary. The VGA for the U(IV) process showed that because of the large capital investment required, this approach to waste reduction was not economically competitive with another alternative that required only modifying the ongoing Purex process at no additional capital cost. However, implementing he U(IV) process as part of an overall canyon renovation, presently scheduled for the 1990's, may be economically attractive. The purpose of this TDS is therefore to bring together the information and experience obtained thus far in the U(IV) program so that a useful body of information will be available to support any future development of this process

Interactions and Localization of Escherichia coli Error-Prone DNA Polymerase IV after DNA Damage.

Science.gov (United States)

Mallik, Sarita; Popodi, Ellen M; Hanson, Andrew J; Foster, Patricia L

2015-09-01

Escherichia coli's DNA polymerase IV (Pol IV/DinB), a member of the Y family of error-prone polymerases, is induced during the SOS response to DNA damage and is responsible for translesion bypass and adaptive (stress-induced) mutation. In this study, the localization of Pol IV after DNA damage was followed using fluorescent fusions. After exposure of E. coli to DNA-damaging agents, fluorescently tagged Pol IV localized to the nucleoid as foci. Stepwise photobleaching indicated ∼60% of the foci consisted of three Pol IV molecules, while ∼40% consisted of six Pol IV molecules. Fluorescently tagged Rep, a replication accessory DNA helicase, was recruited to the Pol IV foci after DNA damage, suggesting that the in vitro interaction between Rep and Pol IV reported previously also occurs in vivo. Fluorescently tagged RecA also formed foci after DNA damage, and Pol IV localized to them. To investigate if Pol IV localizes to double-strand breaks (DSBs), an I-SceI endonuclease-mediated DSB was introduced close to a fluorescently labeled LacO array on the chromosome. After DSB induction, Pol IV localized to the DSB site in ∼70% of SOS-induced cells. RecA also formed foci at the DSB sites, and Pol IV localized to the RecA foci. These results suggest that Pol IV interacts with RecA in vivo and is recruited to sites of DSBs to aid in the restoration of DNA replication. DNA polymerase IV (Pol IV/DinB) is an error-prone DNA polymerase capable of bypassing DNA lesions and aiding in the restart of stalled replication forks. In this work, we demonstrate in vivo localization of fluorescently tagged Pol IV to the nucleoid after DNA damage and to DNA double-strand breaks. We show colocalization of Pol IV with two proteins: Rep DNA helicase, which participates in replication, and RecA, which catalyzes recombinational repair of stalled replication forks. Time course experiments suggest that Pol IV recruits Rep and that RecA recruits Pol IV. These findings provide in vivo evidence

Ionizing radiation risk assessment, BEIR IV

International Nuclear Information System (INIS)

1991-10-01

This report of the Subpanel discusses the potential impact on Federal agencies and indicates individual risk factors that could be used by them in risk assessment. The approach used in this CIRRPC report was to consider the risk factors presented in BEIR IV for each radionuclide (or group radioelements) and to make some judgments regarding their validity and/or the uncertainties involved. The coverage of Radon-222 and its progeny dominated the BEIR IV report and this Subpanel felt is was proper to devote more attention to this radionuclide family. This risk factor presented in BEIR IV for radon is 350 cancer deaths per million person-working level months (WLM) of exposure for a lifetime. There is a range of opinions on the conversion from WLM to absorbed dose. As discussed in the text, the use of the WLM concept makes it difficult or infeasible to compare the risk factor for radon with that of other radionuclides which are based on organ dose. This report also includes a discussion of certain fundamental scientific and operational issues that may have decisive effect upon risk factor selection. These adjunct items are dealt with under separate headings and include discussions of threshold dose considerations, extrapolation to low doses, and age at exposure

17 CFR Table IV to Subpart E of... - Civil Monetary Penalty Inflation Adjustments

Science.gov (United States)

2010-04-01

... Inflation Adjustments IV Table IV to Subpart E of Part 201 Commodity and Securities Exchanges SECURITIES AND... Table IV to Subpart E of Part 201—Civil Monetary Penalty Inflation Adjustments Table IV to Subpart E U.S. Code citation Civil monetary penalty inflation adjustments Civil monetary penalty description Year...

Molecular profiling reveals biologically discrete subsets and pathways of progression in diffuse glioma

Science.gov (United States)

Ceccarelli, Michele; Barthel, Floris P.; Malta, Tathiane M.; Sabedot, Thais S.; Salama, Sofie R.; Murray, Bradley A.; Morozova, Olena; Newton, Yulia; Radenbaugh, Amie; Pagnotta, Stefano M.; Anjum, Samreen; Wang, Jiguang; Manyam, Ganiraju; Zoppoli, Pietro; Ling, Shiyung; Rao, Arjun A.; Grifford, Mia; Cherniack, Andrew D.; Zhang, Hailei; Poisson, Laila; Carlotti, Carlos Gilberto; Pretti da Cunha Tirapelli, Daniela; Rao, Arvind; Mikkelsen, Tom; Lau, Ching C.; Yung, W.K. Alfred; Rabadan, Raul; Huse, Jason; Brat, Daniel J.; Lehman, Norman L.; Barnholtz-Sloan, Jill S.; Zheng, Siyuan; Hess, Kenneth; Rao, Ganesh; Meyerson, Matthew; Beroukhim, Rameen; Cooper, Lee; Akbani, Rehan; Wrensch, Margaret; Haussler, David; Aldape, Kenneth D.; Laird, Peter W.; Gutmann, David H.; Noushmehr, Houtan; Iavarone, Antonio; Verhaak, Roel G.W.

2015-01-01

SUMMARY Therapy development for adult diffuse glioma is hindered by incomplete knowledge of somatic glioma driving alterations and suboptimal disease classification. We defined the complete set of genes associated with 1,122 diffuse grade II-III-IV gliomas from The Cancer Genome Atlas and used molecular profiles to improve disease classification, identify molecular correlations, and provide insights into the progression from low- to high-grade disease. Whole genome sequencing data analysis determined that ATRX but not TERT promoter mutations are associated with increased telomere length. Recent advances in glioma classification based on IDH mutation and 1p/19q co-deletion status were recapitulated through analysis of DNA methylation profiles, which identified clinically relevant molecular subsets. A subtype of IDH-mutant glioma was associated with DNA demethylation and poor outcome; a group of IDH-wildtype diffuse glioma showed molecular similarity to pilocytic astrocytoma and relatively favorable survival. Understanding of cohesive disease groups may aid improved clinical outcomes. PMID:26824661

Revised and extended analysis of Br IV

International Nuclear Information System (INIS)

Riyaz, A.; Rahimullah, K.; Tauheed, A.

2014-01-01

The spectrum of three-times ionized bromine Br IV has been studied in the 319–2350 Å wavelength region. The spectrum was recorded on a 3-m normal incidence vacuum spectrograph at the St. Francis Xavier University, Antigonish (Canada) and 6.65-m grazing incidence spectrograph at the Zeeman laboratory (Amsterdam). The light sources used were a triggered spark and sliding spark, respectively. The ground configuration of Br IV 3d 10 4s 2 4p 2 , the excited configurations 3d 10 4s4p 3 +3d 10 4s 2 4p (4d+5d+6d+5s+6s+7s) in the odd parity system and 3d 10 4s 2 4p (5p+4f+5f)+3d 10 4s4p 2 (4d+5s)+3d 10 4p 4 in the even parity system have been studied. Relativistic Hartree–Fock (HFR) and least squares fitted (LSF) parametric calculations were used to interpret the observed spectrum. 120 Levels of Br IV have now been established, 58 being new. Among 424 spectral lines, 277 are newly classified. The levels 4s4p 35 S 2 , 4s 2 4p4d 3 F 4 and 4p5p ( 3 P 0,1 , 3 D 1,2 , 3 S 1 ) are revised. We estimate the accuracy of our measured wavelength for sharp and unblended lines to be ±0.005 Å. The ionization limit is determined as 385,390±100 cm −1 (47.782±0.012 eV). -- Highlights: • The spectrum of Br was recorded on a 3-m spectrograph with triggered spark source. • Atomic transitions for Br IV were identified to established new energy levels. • CI calculations with relativistic corrections were made for theoretical predictions. • Weighted oscillator strength (gf) and transition probabilities (gA) were calculated. • Ionization potential of Br IV was determined experimentally

Polymer-bound oxidovanadium(IV) and dioxidovanadium(V) complexes as catalysts for the oxidative desulfurization of model fuel diesel.

Science.gov (United States)

Maurya, Mannar R; Arya, Aarti; Kumar, Amit; Kuznetsov, Maxim L; Avecilla, Fernando; Costa Pessoa, João

2010-07-19

The Schiff base (Hfsal-dmen) derived from 3-formylsalicylic acid and N,N-dimethyl ethylenediamine has been covalently bonded to chloromethylated polystyrene to give the polymer-bound ligand, PS-Hfsal-dmen (I). Treatment of PS-Hfsal-dmen with [V(IV)O(acac)(2)] in the presence of MeOH gave the oxidovanadium(IV) complex PS-[V(IV)O(fsal-dmen)(MeO)] (1). On aerial oxidation in methanol, complex 1 was oxidized to PS-[V(V)O(2)(fsal-dmen)] (2). The corresponding neat complexes, [V(IV)O(sal-dmen)(acac)] (3) and [V(V)O(2)(sal-dmen)] (4) were similarly prepared. All these complexes are characterized by various spectroscopic techniques (IR, electronic, NMR, and electron paramagnetic resonance (EPR)) and thermal as well as field-emission scanning electron micrographs (FE-SEM) studies, and the molecular structures of 3 and 4 were determined by single crystal X-ray diffraction. The EPR spectrum of the polymer supported V(IV)O-complex 1 is characteristic of magnetically diluted V(IV)O-complexes, the resolved EPR pattern indicating that the V(IV)O-centers are well dispersed in the polymer matrix. A good (51)V NMR spectrum could also be measured with 4 suspended in dimethyl sulfoxide (DMSO), the chemical shift (-503 ppm) being compatible with a VO(2)(+)-center and a N,O binding set. The catalytic oxidative desulfurization of organosulfur compounds thiophene, dibenzothiophene, benzothiophene, and 2-methyl thiophene (model of fuel diesel) was carried out using complexes 1 and 2. The sulfur in model organosulfur compounds oxidizes to the corresponding sulfone in the presence of H(2)O(2). The systems 1 and 2 do not loose efficiency for sulfoxidation at least up to the third cycle of reaction, this indicating that they preserve their integrity under the conditions used. Plausible intermediates involved in these catalytic processes are established by UV-vis, EPR, (51)V NMR, and density functional theory (DFT) studies, and an outline of the mechanism is proposed. The (51)V NMR spectra

IV Encuentro Latinoamericano de Revistas de Arquitectura, Tlaxcala, México, Junio 1989

Directory of Open Access Journals (Sweden)

IV Seminario de Arquitectura Latinoamericana

1989-12-01

Full Text Available En el marco del IV Seminario de Arquitectura Latinoamericana - SAL IV - realizado en Tlaxcala, México, entre el 29 de mayo y el 2 de junio de 1989, tuvo lugar el IV Encuentro Latinoamericano de Revistas de Arquitectura.

Lowered serum dipeptidyl peptidase IV activity in patients with anorexia and bulimia nervosa.

Science.gov (United States)

van West, D; Monteleone, P; Di Lieto, A; De Meester, I; Durinx, C; Scharpe, S; Lin, A; Maj, M; Maes, M

2000-01-01

The aim of this study was to examine whether anorexia nervosa and bulimia nervosa are accompanied by lower serum activity of dipeptidyl peptidase IV (DPP IV, EC 3.4.14.5), a membrane-bound serine protease that catalyses the cleavage of dipeptides from the amino-terminus of oligo- and polypeptides. Substrates of DPP IV are, amongst others, neuroactive eptides, such as substance P, growth hormone releasing hormone, neuropeptide Y, and peptide YY. DPP IV activity was measured in the serum of 21 women with anorexia nervosa, 21 women with bulimia nervosa and 18 normal women. Serum DPP IV activity was significantly lower in patients with anorexia nervosa and bulimia nervosa than in the normal controls. In the total study group, there were significant and inverse relationships between serum DPP IV activity and the total scores on the Bulimic Investigatory Test, Edinburgh, the Eating Disorder Inventory (EDI) and the Hamilton Depression Rating Scale. In the total study group no significant correlations between DPP IV and age, body weight or body mass index could be found. It is concluded that lowered serum DPP IV activity takes part in the pathophysiology of anorexia and bulimia nervosa. It is hypothesised that a combined dysregulation of DPP IV and neuroactive peptides, which are substrates of DPP IV, e.g. neuropeptide Y and peptide YY, could be an integral component of eating disorders.

Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

Science.gov (United States)

Pedrosa, Fábio O; Monteiro, Rose Adele; Wassem, Roseli; Cruz, Leonardo M; Ayub, Ricardo A; Colauto, Nelson B; Fernandez, Maria Aparecida; Fungaro, Maria Helena P; Grisard, Edmundo C; Hungria, Mariangela; Madeira, Humberto M F; Nodari, Rubens O; Osaku, Clarice A; Petzl-Erler, Maria Luiza; Terenzi, Hernán; Vieira, Luiz G E; Steffens, Maria Berenice R; Weiss, Vinicius A; Pereira, Luiz F P; Almeida, Marina I M; Alves, Lysangela R; Marin, Anelis; Araujo, Luiza Maria; Balsanelli, Eduardo; Baura, Valter A; Chubatsu, Leda S; Faoro, Helisson; Favetti, Augusto; Friedermann, Geraldo; Glienke, Chirlei; Karp, Susan; Kava-Cordeiro, Vanessa; Raittz, Roberto T; Ramos, Humberto J O; Ribeiro, Enilze Maria S F; Rigo, Liu Un; Rocha, Saul N; Schwab, Stefan; Silva, Anilda G; Souza, Eliel M; Tadra-Sfeir, Michelle Z; Torres, Rodrigo A; Dabul, Audrei N G; Soares, Maria Albertina M; Gasques, Luciano S; Gimenes, Ciela C T; Valle, Juliana S; Ciferri, Ricardo R; Correa, Luiz C; Murace, Norma K; Pamphile, João A; Patussi, Eliana Valéria; Prioli, Alberto J; Prioli, Sonia Maria A; Rocha, Carmem Lúcia M S C; Arantes, Olívia Márcia N; Furlaneto, Márcia Cristina; Godoy, Leandro P; Oliveira, Carlos E C; Satori, Daniele; Vilas-Boas, Laurival A; Watanabe, Maria Angélica E; Dambros, Bibiana Paula; Guerra, Miguel P; Mathioni, Sandra Marisa; Santos, Karine Louise; Steindel, Mario; Vernal, Javier; Barcellos, Fernando G; Campo, Rubens J; Chueire, Ligia Maria O; Nicolás, Marisa Fabiana; Pereira-Ferrari, Lilian; Silva, José L da Conceição; Gioppo, Nereida M R; Margarido, Vladimir P; Menck-Soares, Maria Amélia; Pinto, Fabiana Gisele S; Simão, Rita de Cássia G; Takahashi, Elizabete K; Yates, Marshall G; Souza, Emanuel M

2011-05-01

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

Directory of Open Access Journals (Sweden)

Fábio O Pedrosa

2011-05-01

Full Text Available The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Molecular epidemiology is becoming complex under the dynamic HIV prevalence: The perspective from Harbin, China.

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Shao, Bing; Song, Bo; Cao, Lijun; Du, Juan; Sun, Dongying; Lin, Yuanlong; Wang, Binyou; Wang, Fuxiang; Wang, Sunran

2016-05-01

Unlike most areas of China, HIV transmission via men who have sex with men (MSM) is increasing rapidly, and has become the main route of HIV transmission in Harbin city. The purpose of the current study was to elaborate the molecular epidemiologic characteristics of the new HIV epidemic. Eighty-one HIV-1 gag gene sequences (HXB2:806-1861) from local HIV infections were isolated; CRF01_AE predominated among HIV infections (71.6%), followed by subtype B (16.5%), CRF07_BC (6.2%), and unique recombinant strains (URFs; 6.2%). URFs were most often identified in the MSM population, which consisted of a recombination of CRF01_AE with subtype B or CRF07_BC. Six clusters were formed in this analysis; clusters I and II mainly circulated in southwest China. Clusters III and IV mainly circulated in southwest, southeast, and central China. Clusters V and VI mainly circulated in north and northeast China. Clusters III and IV may facilitate the transmission of the CRF01_AE strain from the southwest to the north and northeast regions of China. HIV subtypes are becoming diverse with the persistent epidemic in this geographic region. In brief, our results indicate that the molecular epidemiology of HIV is trending to be more complex. Thus, timely molecular epidemiologic supervision of HIV is necessary, especially for the MSM population. © 2015 Wiley Periodicals, Inc.

Asymmetric reduction of ketones with catecholborane using 2,6-BODOL complexes of titanium(IV) as catalysts.

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Sarvary, I; Almqvist, F; Frejd, T

2001-05-18

Reductions performed with Ti(IV) complexes of ligands based on bicyclo[2.2.2]octane diols 5 and 6 are effective catalysts in the reduction of prochiral ketones to optically active alcohols, with catecholborane as the reducing agent. Methyl ketones are favored and enantiomeric excesses (ee) of octanone, which gave 2-octanol in 87% ee. Further details of the method were examined, for example, temperature, solvent composition, amount of molecular sieves (4 A), and catecholborane quality, as well as the sensitivity of the ligands towards acids. NMR spectroscopic methods were used to gain some insight into the complexes formed between the ligands and [Ti(OiPr)4]. A dimeric structure is proposed for the pre-catalyst.

Implementation of SAP-IV on a minicomputer disc operating system

International Nuclear Information System (INIS)

Spencer, R.B.; Howard, G.E.

1977-01-01

The objective of the described effort was the implementation of a linear elastic finite element structural analysis program version on a minicomputer operating system while maintaining (as much as possible) the general features of the original program. SAP-IV has been successfully implemented on a minicomputer operating system as one component in a portable vibration testing, data acquisition and processing, parameter identification and design optimization system for field work. The primary features in SAP-IV facilitating conversion and implementation on a minicomputer are: (1) the calculational procedures of SAP-IV are well documented and the subroutine structure easy to follow; (2) SAP-IV is organized in a highly modular fashion; (3) it is versatile with respect to its calculational options; and (4) the element library can be readily expanded. (Auth.)

Conservation of Ebp-type pilus genes among Enterococci and demonstration of their role in adherence of Enterococcus faecalis to human platelets.

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Nallapareddy, Sreedhar R; Sillanpää, Jouko; Mitchell, Jennifer; Singh, Kavindra V; Chowdhury, Shahreen A; Weinstock, George M; Sullam, Paul M; Murray, Barbara E

2011-07-01

Ebp are endocarditis- and biofilm-associated pili of Enterococcus faecalis that are also important in experimental urinary tract infections (UTIs). Our analyses, using available genomes, found that the ebp locus is unique to enterococci. In E. faecalis, the ebp locus is very highly conserved and only 1/473 E. faecalis isolates tested lacked ebpABC, while only 1.2% had the bee pilus locus. No other pilus-encoding operon was identified in 55 available genomes, indicating that the vast majority of E. faecalis strains (unlike Enterococcus faecium and streptococci) have a single pilus locus. Surface expression studies showed that Ebp pili were produced in vitro by 91/91 brain heart infusion (BHI) plus serum-grown E. faecalis isolates and that strain OG1RF expressed pili at even higher levels in rat endocarditis vegetations. However, Ebp expression was restricted to 30 to 72% of E. faecalis cells, consistent with a bistability mode of expression. We also evaluated E. faecalis interactions with human platelets and found that growth of E. faecalis in BHI plus serum significantly enhanced adherence to human platelets and that sortase deletion mutants (the ΔsrtA, Δbps, and ΔbpsΔsrtA mutants) were markedly defective. Further studies identified that Ebp pili, but not the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) Ace and Fss2, mediate adherence of E. faecalis to platelets. Taken together, our data show that the immunogenic (in human endocarditis patients) and commonly expressed Ebp pili, which are known to be important for experimental endocarditis, are highly conserved and mediate adherence to platelets, suggesting that Ebp pili may be a reasonable immunotherapeutic target for prevention or possibly treatment of endocarditis caused by this species.

Conservation of Ebp-Type Pilus Genes among Enterococci and Demonstration of Their Role in Adherence of Enterococcus faecalis to Human Platelets ▿ †

Science.gov (United States)

Nallapareddy, Sreedhar R.; Sillanpää, Jouko; Mitchell, Jennifer; Singh, Kavindra V.; Chowdhury, Shahreen A.; Weinstock, George M.; Sullam, Paul M.; Murray, Barbara E.

2011-01-01

Ebp are endocarditis- and biofilm-associated pili of Enterococcus faecalis that are also important in experimental urinary tract infections (UTIs). Our analyses, using available genomes, found that the ebp locus is unique to enterococci. In E. faecalis, the ebp locus is very highly conserved and only 1/473 E. faecalis isolates tested lacked ebpABC, while only 1.2% had the bee pilus locus. No other pilus-encoding operon was identified in 55 available genomes, indicating that the vast majority of E. faecalis strains (unlike Enterococcus faecium and streptococci) have a single pilus locus. Surface expression studies showed that Ebp pili were produced in vitro by 91/91 brain heart infusion (BHI) plus serum-grown E. faecalis isolates and that strain OG1RF expressed pili at even higher levels in rat endocarditis vegetations. However, Ebp expression was restricted to 30 to 72% of E. faecalis cells, consistent with a bistability mode of expression. We also evaluated E. faecalis interactions with human platelets and found that growth of E. faecalis in BHI plus serum significantly enhanced adherence to human platelets and that sortase deletion mutants (the ΔsrtA, Δbps, and ΔbpsΔsrtA mutants) were markedly defective. Further studies identified that Ebp pili, but not the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) Ace and Fss2, mediate adherence of E. faecalis to platelets. Taken together, our data show that the immunogenic (in human endocarditis patients) and commonly expressed Ebp pili, which are known to be important for experimental endocarditis, are highly conserved and mediate adherence to platelets, suggesting that Ebp pili may be a reasonable immunotherapeutic target for prevention or possibly treatment of endocarditis caused by this species. PMID:21502588

Biofilm formation and binding specificities of CFA/I, CFA/II and CS2 adhesions of enterotoxigenic Escherichia coli and Cfae-R181A mutant.

Science.gov (United States)

Liaqat, Iram; Sakellaris, Harry

2012-07-01

Enterotoxigenic Escherichia coli (ETEC) strains are leading causes of childhood diarrhea in developing countries. Adhesion is the first step in pathogenesis of ETEC infections and ETEC pili designated colonization factor antigens (CFAs) are believed to be important in the biofim formation, colonization and host cell adhesions. As a first step, we have determined the biofilm capability of ETEC expressing various types of pili (CFA/I, CfaE-R181A mutant/CfaE tip mutant, CFA/II and CS2). Further, enzyme-linked immunosorbent assay (ELISA) assay were developed to compare the binding specificity of CFA/I, CFA/II (CS1 - CS3) and CS2 of ETEC, using extracted pili and piliated bacteria. CFA/II strain (E24377a) as well as extracted pili exhibited significantly higher binding both in biofilm and ELISA assays compared to non piliated wild type E24377a, CFA/I and CS2 strains. This indicates that co-expression of two or more CS2 in same strain is more efficient in increasing adherence. Significant decrease in binding specificity of DH5αF'lacI (q)/∆cotD (CS2) strain and MC4100/pEU2124 (CfaE-R181A) mutant strain indicated the important contribution of tip proteins in adherence assays. However, CS2 tip mutant strain (DH5αF'lacI (q)/pEU5881) showed that this specific residue may not be important as adhesions in these strains. In summary, our data suggest that pili, their minor subunits are important for biofilm formation and adherence mechanisms. Overall, the functional reactivity of strains co expressing various antigens, particularly minor subunit antigen observed in this study suggest that fewer antibodies may be required to elicit immunity to ETEC expressing a wider array of related pili.

Molecular characterization of three novel Fanconi anemia mutations in Israeli Arabs.

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Tamary, Hannah; Dgany, Orly; Toledano, Helen; Shalev, Zvi; Krasnov, Tatyana; Shalmon, Lea; Schechter, Tali; Bercovich, Dani; Attias, Dina; Laor, Ruth; Koren, Ariel; Yaniv, Isaac

2004-05-01

In a previous study, we investigated the molecular basis of Fanconi anemia (FA) in 13 unrelated Israeli Jewish FA patients and identified four ethnicity specific mutations. In the present study we extended our study to Israeli Arab patients. We studied three consanguineous families with nine FA patients and an additional unrelated patient. DNA single-strand conformation polymorphism of each exon of the FANCA and FANCG genes was followed by sequence analysis of the aberrantly migrating fragments and by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of the splice-site mutations identified. Three unique disease-causing mutations were identified: (i) FANCA gross deletion of exons 6-31; (ii) FANCA splice-site mutation IVS 42-2A>C; (iii) FANCG splice-site mutation IVS4+3A>G. Sequence analysis of the FANCA gross deletion revealed recombination between two highly homologous Alu elements. cDNA analysis of the two splice mutations suggested intron 42 retention in FANCA IVS 42-2A>C and exon 4 skipping in FANCG IVS4+3A>G. The clinical condition of eight patients with FANCA mutations was severe. Two unique FANCA mutations and one FANCG mutation were identified in Israeli Arab FA patients. Deletion of FANCA exon 6-31 as in previously described gross deletions was within introns rich in Alu repeats. To the best of our knowledge, the FANCA IVS 42-2A>C mutation is the first in this gene to result in intron retention. Further analysis of FA mutations will enable prenatal diagnosis and a rational therapeutic approach including frequent monitoring and early bone marrow transplantation. Copyright Blackwell Munksgaard 2004.

Hafnium(IV) complexation with oxalate at variable temperatures

Energy Technology Data Exchange (ETDEWEB)

Friend, Mitchell T.; Wall, Nathalie A. [Washington State Univ., Pullmanm, WA (United States). Dept. of Chemistry

2017-08-01

Appropriate management of fission products in the reprocessing of spent nuclear fuel (SNF) is crucial in developing advanced reprocessing schemes. The addition of aqueous phase complexing agents can prevent the co-extraction of these fission products. A solvent extraction technique was used to study the complexation of Hf(IV) - an analog to fission product Zr(IV) - with oxalate at 15, 25, and 35 C in 1 M HClO{sub 4} utilizing a {sup 175+181}Hf radiotracer. The mechanism of the solvent extraction system of 10{sup -5} M Hf(IV) in 1 M HClO{sub 4} to thenoyltrifluoroacetone (TTA) in toluene demonstrated a 4{sup th}-power dependence in both TTA and H{sup +}, with Hf(TTA){sub 4} the only extractable species. The equilibrium constant for the extraction of Hf(TTA){sub 4} was determined to be log K{sub ex}=7.67±0.07 (25±1 C, 1 M HClO{sub 4}). The addition of oxalate to the aqueous phase decreased the distribution ratio, indicating aqueous Hf(IV)-oxalate complex formation. Polynomial fits to the distribution data identified the formation of Hf(ox){sup 2+} and Hf(ox){sub 2(aq)} and their stability constants were measured at 15, 25, and 35 C in 1 M HClO{sub 4}. van't Hoff analysis was used to calculate Δ{sub r}G, Δ{sub r}H, and Δ{sub r}S for these species. Stability constants were observed to increase at higher temperature, an indication that Hf(IV)-oxalate complexation is endothermic and driven by entropy.

CHARGE syndrome: a recurrent hotspot of mutations in CHD7 IVS25 analyzed by bioinformatic tools and minigene assays.

Science.gov (United States)

Legendre, Marine; Rodriguez-Ballesteros, Montserrat; Rossi, Massimiliano; Abadie, Véronique; Amiel, Jeanne; Revencu, Nicole; Blanchet, Patricia; Brioude, Frédéric; Delrue, Marie-Ange; Doubaj, Yassamine; Sefiani, Abdelaziz; Francannet, Christine; Holder-Espinasse, Muriel; Jouk, Pierre-Simon; Julia, Sophie; Melki, Judith; Mur, Sébastien; Naudion, Sophie; Fabre-Teste, Jennifer; Busa, Tiffany; Stamm, Stephen; Lyonnet, Stanislas; Attie-Bitach, Tania; Kitzis, Alain; Gilbert-Dussardier, Brigitte; Bilan, Frédéric

2018-02-01

CHARGE syndrome is a rare genetic disorder mainly due to de novo and private truncating mutations of CHD7 gene. Here we report an intriguing hot spot of intronic mutations (c.5405-7G > A, c.5405-13G > A, c.5405-17G > A and c.5405-18C > A) located in CHD7 IVS25. Combining computational in silico analysis, experimental branch-point determination and in vitro minigene assays, our study explains this mutation hot spot by a particular genomic context, including the weakness of the IVS25 natural acceptor-site and an unconventional lariat sequence localized outside the common 40 bp upstream the acceptor splice site. For each of the mutations reported here, bioinformatic tools indicated a newly created 3' splice site, of which the existence was confirmed using pSpliceExpress, an easy-to-use and reliable splicing reporter tool. Our study emphasizes the idea that combining these two complementary approaches could increase the efficiency of routine molecular diagnosis.

Surface contact stimulates the just-in-time deployment of bacterial adhesins.

Science.gov (United States)

Li, Guanglai; Brown, Pamela J B; Tang, Jay X; Xu, Jing; Quardokus, Ellen M; Fuqua, Clay; Brun, Yves V

2012-01-01

The attachment of bacteria to surfaces provides advantages such as increasing nutrient access and resistance to environmental stress. Attachment begins with a reversible phase, often mediated by surface structures such as flagella and pili, followed by a transition to irreversible attachment, typically mediated by polysaccharides. Here we show that the interplay between pili and flagellum rotation stimulates the rapid transition between reversible and polysaccharide-mediated irreversible attachment. We found that reversible attachment of Caulobacter crescentus cells is mediated by motile cells bearing pili and that their contact with a surface results in the rapid pili-dependent arrest of flagellum rotation and concurrent stimulation of polar holdfast adhesive polysaccharide. Similar stimulation of polar adhesin production by surface contact occurs in Asticcacaulis biprosthecum and Agrobacterium tumefaciens. Therefore, single bacterial cells respond to their initial contact with surfaces by triggering just-in-time adhesin production. This mechanism restricts stable attachment to intimate surface interactions, thereby maximizing surface attachment, discouraging non-productive self-adherence, and preventing curing of the adhesive. © 2011 Blackwell Publishing Ltd.

The Cryoelectron Microscopy Structure of the Type 1 Chaperone-Usher Pilus Rod.

Science.gov (United States)

Hospenthal, Manuela K; Zyla, Dawid; Costa, Tiago R D; Redzej, Adam; Giese, Christoph; Lillington, James; Glockshuber, Rudi; Waksman, Gabriel

2017-12-05

Adhesive chaperone-usher pili are long, supramolecular protein fibers displayed on the surface of many bacterial pathogens. The type 1 and P pili of uropathogenic Escherichia coli (UPEC) play important roles during urinary tract colonization, mediating attachment to the bladder and kidney, respectively. The biomechanical properties of the helical pilus rods allow them to reversibly uncoil in response to flow-induced forces, allowing UPEC to retain a foothold in the unique and hostile environment of the urinary tract. Here we provide the 4.2-Å resolution cryo-EM structure of the type 1 pilus rod, which together with the previous P pilus rod structure rationalizes the remarkable "spring-like" properties of chaperone-usher pili. The cryo-EM structure of the type 1 pilus rod differs in its helical parameters from the structure determined previously by a hybrid approach. We provide evidence that these structural differences originate from different quaternary structures of pili assembled in vivo and in vitro. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Molecular epidemiology of Methicillin-resistant Staphylococcus aureus in Africa: a systematic review

Science.gov (United States)

Abdulgader, Shima M.; Shittu, Adebayo O.; Nicol, Mark P.; Kaba, Mamadou

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections are a serious global problem, with considerable impact on patients and substantial health care costs. This systematic review provides an overview on the clonal diversity of MRSA, as well as the prevalence of Panton-Valentine leukocidin (PVL)-positive MRSA in Africa. A search on the molecular characterization of MRSA in Africa was conducted by two authors using predefined terms. We screened for articles published in English and French through to October 2014 from five electronic databases. A total of 57 eligible studies were identified. Thirty-four reports from 15 countries provided adequate genotyping data. CC5 is the predominant clonal complex in the healthcare setting in Africa. The hospital-associated MRSA ST239/ST241-III [3A] was identified in nine African countries. This clone was also described with SCCmec type IV [2B] in Algeria and Nigeria, and type V [5C] in Niger. In Africa, the European ST80-IV [2B] clone was limited to Algeria, Egypt and Tunisia. The clonal types ST22-IV [2B], ST36-II [2A], and ST612-IV [2B] were only reported in South Africa. No clear distinctions were observed between MRSA responsible for hospital and community infections. The community clones ST8-IV [2B] and ST88-IV [2B] were reported both in the hospital and community settings in Angola, Cameroon, Gabon, Ghana, Madagascar, Nigeria, and São Tomé and Príncipe. The proportion of PVL-positive MRSA carriage and/or infections ranged from 0.3 to 100% in humans. A number of pandemic clones were identified in Africa. Moreover, some MRSA clones are limited to specific countries or regions. We strongly advocate for more surveillance studies on MRSA in Africa. PMID:25983721

Abdominal 64-MDCT for suspected appendicitis: the use of oral and IV contrast material versus IV contrast material only.

Science.gov (United States)

Anderson, Stephan W; Soto, Jorge A; Lucey, Brian C; Ozonoff, Al; Jordan, Jacqueline D; Ratevosian, Jirair; Ulrich, Andrew S; Rathlev, Niels K; Mitchell, Patricia M; Rebholz, Casey; Feldman, James A; Rhea, James T

2009-11-01

The objective of our study was to compare the diagnostic accuracy of IV contrast-enhanced 64-MDCT with and without the use of oral contrast material in diagnosing appendicitis in patients with abdominal pain. We conducted a randomized trial of a convenience sample of adult patients presenting to an urban academic emergency department with acute nontraumatic abdominal pain and clinical suspicion of appendicitis, diverticulitis, or small-bowel obstruction. Patients were enrolled between 8 am and 11 pm when research assistants were present. Consenting subjects were randomized into one of two groups: Group 1 subjects underwent 64-MDCT performed with oral and IV contrast media and group 2 subjects underwent 64-MDCT performed solely with IV contrast material. Three expert radiologists independently reviewed the CT examinations, evaluating for the presence of appendicitis. Each radiologist interpreted 202 examinations, ensuring that each examination was interpreted by two radiologists. Individual reader performance and a combined interpretation performance of the two readers assigned to each case were calculated. In cases of disagreement, the third reader was asked to deliver a tiebreaker interpretation to be used to calculate the combined reader performance. Final outcome was based on operative, clinical, and follow-up data. We compared radiologic diagnoses with clinical outcomes to calculate the diagnostic accuracy of CT in both groups. Of the 303 patients enrolled, 151 patients (50%) were randomized to group 1 and the remaining 152 (50%) were randomized to group 2. The combined reader performance for the diagnosis of appendicitis in group 1 was a sensitivity of 100% (95% CI, 76.8-100%) and specificity of 97.1% (95% CI, 92.7-99.2%). The performance in group 2 was a sensitivity of 100% (73.5-100%) and specificity of 97.1% (92.9-99.2%). Patients presenting with nontraumatic abdominal pain imaged using 64-MDCT with isotropic reformations had similar characteristics for the

Sorption of Pu(IV) from nitric acid by bifunctional anion-exchange resins

International Nuclear Information System (INIS)

Bartsch, R.A.; Zhang, Z.Y.; Elshani, S.; Zhao, W.; Jarvinen, G.D.; Barr, M.E.; Marsh, S.F.; Chamberlin, R.M.

1999-01-01

Anion exchange is attractive for separating plutonium because the Pu(IV) nitrate complex is very strongly sorbed and few other metal ions form competing anionic nitrate complexes. The major disadvantage of this process has been the unusually slow rate at which the Pu(IV) nitrate complex is sorbed by the resin. The paper summarizes the concept of bifunctional anion-exchange resins, proposed mechanism for Pu(IV) sorption, synthesis of the alkylating agent, calculation of K d values from Pu(IV) sorption results, and conclusions from the study of Pu(IV) sorption from 7M nitric acid by macroporous anion-exchange resins including level of crosslinking, level of alkylation, length of spacer, and bifunctional vs. monofunctional anion-exchange resins

Relationship between serum IV-C, β2-m levels and diabetic nephropathy

International Nuclear Information System (INIS)

Liu Lu; Zhang Mukun

2005-01-01

Objective: To investigate the relationship between the serum type IV collagen (IV-C), β 2 -micro globulin (β 2 -m) levels and diabetic nephropathy. Methods: Serum IV-C, β 2 -m levels were measured with RIA in 30 controls and 86 patients with type 2 diabetics mellitus (35 with diabetic nephropathy and 51 without nephropathy). Results: the serum levels of IV-C and β 2 -m in diabetic patients with nephropathy were significantly higher than those in controls (P 0.05). Conclusion: Serum IV-C and β 2 -m levels increased gradually as the diabetic nephropathy got more severe. They could be a sensitive marker for early diagnosis of development of diabetic nephropathy. (authors)

Studies on the oligosaccharide heterogeneity of the isoelectric forms of the lower molecular weight acid phosphatase of frog liver.

Science.gov (United States)

Kubicz, A; Szalewicz, A; Chrambach, A

1991-01-01

1. The lower molecular weight, heterogeneous acid phosphatase (AcPase) from the frog liver (Rana esculenta) containing AcPase I, II, III and IV was separated into enzymatically active components by isoelectric focusing in an immobilized pH gradient. 2. The blotted enzyme bands were characterized by their different binding patterns obtained with the lectins concanavalin A, wheat germ agglutinin (WGA), Lens culinaris hemagglutinin (LcH) and peanut agglutinin (PNA). 3. In situ neuraminidase treatment reduced the staining intensity of some WGA-bands and increased that of PNA-bands. 4. The finding that AcPases I, II, III and IV differ in their carbohydrate chain composition, together with previous results showing different bioactivities of AcPases III and IV, indicates a correlation between the glycosylation state of enzyme forms and their physiological action.

Adaptation of U(IV) reductant to Savannah River Plant Purex processes

International Nuclear Information System (INIS)

Orebaugh, E.G.