Theory of population coupling and applications to describe high order correlations in large populations of interacting neurons

NASA Astrophysics Data System (ADS)

Huang, Haiping

2017-03-01

To understand the collective spiking activity in neuronal populations, it is essential to reveal basic circuit variables responsible for these emergent functional states. Here, I develop a mean field theory for the population coupling recently proposed in the studies of the visual cortex of mouse and monkey, relating the individual neuron activity to the population activity, and extend the original form to the second order, relating neuron-pair’s activity to the population activity, to explain the high order correlations observed in the neural data. I test the computational framework on the salamander retinal data and the cortical spiking data of behaving rats. For the retinal data, the original form of population coupling and its advanced form can explain a significant fraction of two-cell correlations and three-cell correlations, respectively. For the cortical data, the performance becomes much better, and the second order population coupling reveals non-local effects in local cortical circuits.

Sequence-specific activation of the DNA sensor cGAS by Y-form DNA structures as found in primary HIV-1 cDNA.

PubMed

Herzner, Anna-Maria; Hagmann, Cristina Amparo; Goldeck, Marion; Wolter, Steven; Kübler, Kirsten; Wittmann, Sabine; Gramberg, Thomas; Andreeva, Liudmila; Hopfner, Karl-Peter; Mertens, Christina; Zillinger, Thomas; Jin, Tengchuan; Xiao, Tsan Sam; Bartok, Eva; Coch, Christoph; Ackermann, Damian; Hornung, Veit; Ludwig, Janos; Barchet, Winfried; Hartmann, Gunther; Schlee, Martin

2015-10-01

Cytosolic DNA that emerges during infection with a retrovirus or DNA virus triggers antiviral type I interferon responses. So far, only double-stranded DNA (dsDNA) over 40 base pairs (bp) in length has been considered immunostimulatory. Here we found that unpaired DNA nucleotides flanking short base-paired DNA stretches, as in stem-loop structures of single-stranded DNA (ssDNA) derived from human immunodeficiency virus type 1 (HIV-1), activated the type I interferon-inducing DNA sensor cGAS in a sequence-dependent manner. DNA structures containing unpaired guanosines flanking short (12- to 20-bp) dsDNA (Y-form DNA) were highly stimulatory and specifically enhanced the enzymatic activity of cGAS. Furthermore, we found that primary HIV-1 reverse transcripts represented the predominant viral cytosolic DNA species during early infection of macrophages and that these ssDNAs were highly immunostimulatory. Collectively, our study identifies unpaired guanosines in Y-form DNA as a highly active, minimal cGAS recognition motif that enables detection of HIV-1 ssDNA.

Functional relevance of protein glycosylation to the pro-inflammatory effects of extracellular matrix metalloproteinase inducer (EMMPRIN) on monocytes/macrophages.

PubMed

Ge, Heng; Yuan, Wei; Liu, Jidong; He, Qing; Ding, Song; Pu, Jun; He, Ben

2015-01-01

Extracellular matrix metalloproteinase inducer (EMMPRIN) is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages. The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells) in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway. 1) It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN) that increased after being exposed to inflammatory signals (PMA and H2O2). 2) Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG) the simple type. 3) Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression). Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages.

The kinetics of the oxidation of cytochrome c by Paracoccus cytochrome c peroxidase.

PubMed

Gilmour, R; Goodhew, C F; Pettigrew, G W; Prazeres, S; Moura, J J; Moura, I

1994-06-15

In work that is complementary to our investigation of the spectroscopic features of the cytochrome c peroxidase from Paracoccus denitrificans [Gilmour, Goodhew, Pettigrew, Prazeres, Moura and Moura (1993) Biochem. J. 294, 745-752], we have studied the kinetics of oxidation of cytochrome c by this enzyme. The enzyme, as isolated, is in the fully oxidized form and is relatively inactive. Reduction of the high-potential haem at pH 6 with ascorbate results in partial activation of the enzyme. Full activation is achieved by addition of 1 mM CaCl2. Enzyme activation is associated with formation of a high-spin state at the oxidized low-potential haem. EGTA treatment of the oxidized enzyme prevents activation after reduction with ascorbate, while treatment with EGTA of the reduced, partially activated, form abolishes the activity. We conclude that the active enzyme is a mixed-valence form with the low-potential haem in a high-spin state that is stabilized by Ca2+. Dilution of the enzyme results in a progressive loss of activity, the extent of which depends on the degree of dilution. Most of the activity lost upon dilution can be recovered after reconcentration. The M(r) of the enzyme on molecular-exclusion chromatography is concentration-dependent, with a shift to lower values at lower concentrations. Values of M(r) obtained are intermediate between those of a monomer (39,565) and a dimer. We propose that the active form of the enzyme is a dimer which dissociates at high dilution to give inactive monomers. From the activity of the enzyme at different dilutions, a KD of 0.8 microM can be calculated for the monomerdimer equilibrium. The cytochrome c peroxidase oxidizes horse ferrocytochrome c with first-order kinetics, even at high ferrocytochrome c concentrations. The maximal catalytic-centre activity ('turnover number') under the assay conditions used is 62,000 min-1, with a half-saturating ferrocytochrome c concentration of 3.3 microM. The corresponding values for the Paracoccus cytochrome c-550 (presumed to be the physiological substrate) are 85,000 min-1 and 13 microM. However, in this case, the kinetics deviate from first-order progress curves at all ferrocytochrome c concentrations. Consideration of the periplasmic environment in Paracoccus denitrificans leads us to propose that the enzyme will be present as the fully active dimer supplied with saturating ferrocytochrome c-550.

Functionalized sorbent for chemical separations and sequential forming process

DOEpatents

Fryxell, Glen E [Kennewick, WA; Zemanian, Thomas S [Richland, WA

2012-03-20

A highly functionalized sorbent and sequential process for making are disclosed. The sorbent includes organic short-length amino silanes and organic oligomeric polyfunctional amino silanes that are dispersed within pores of a porous support that form a 3-dimensional structure containing highly functionalized active binding sites for sorption of analytes.

High aryl acylamidase activity associated with cobra venom acetylcholinesterase: biological significance.

PubMed

Rajesh, Ramanna V; Layer, Paul G; Boopathy, Rathanam

2009-01-01

Investigation of the non-classical functions of cholinesterases (ChEs) has been the subject of interest in the past three decades. One of which is aryl acylamidase (AAA) activity associated with ChEs, but characterized in in vitro, as an enzyme, splitting the artificial substrate o-nitroacetanilide with unknown physiological function. In the present study, we have compared levels of AAA activity of AChE from different sources like goat brain, electric eel organ and from venoms of different snakes. Remarkably cobra venom showed the highest AAA activity and also high AAA/AChE ratio. Both serotonergenic and cholinergic inhibitors inhibited the cobra venom AAA activity in a concentration dependent manner, which also underlines the association of AAA with AChE of cobra venom. The study becomes interesting because of i) the cobra venom AChE exists in monomeric globular forms; ii) in Alzheimer's disease too the most abundant forms of cholinesterases are monomeric globular forms, thought to be involved in the pathogenesis of Alzheimer's disease; iii) the effect of Alzheimer's disease drugs on the AAA activity of cobra venom, indicated that AAA activity of cobra venom was more sensitive than AChE and iv) Huperzine and Tacrine showed more pronounced effect on AAA. Thus, this study elucidates the high AAA associated with cobra venom AChE may serve as one of the prominent activity to test the pharmacological effect of AD drugs, as other sources were found to have lower activity.

The properties of B-form monoamine oxidase in mitochondria from monkey platelet.

PubMed

Obata, Toshio; Aomine, Masahiro

The present study was examined the effect of the properties of monkey platelet monoamine oxidase (MAO) based on inhibitor sensitivity. Monkey platelet showed a high MAO activity with beta-phenylethylamine (beta-PEA) as substrate and a very low A-form MAO activity with 5 hydroxytryptamine (5-HT) as substrate. Moreover, monkey platelet MAO was sensitive to the drugs deprenyl as B-form MAO inhibitor and less sensitive to clorgyline and harmaline as A form MAO inhibitor with beta-PEA as the B-form MAO substrate. B-form MAO from monkey platelet was more stable against heat treatment at 55 degrees C than B-form MAO in brain. After digestion with trypsin at 37 degrees C for 4 hrs, it was found that MAO from platelet was inhibited about 70% with beta-PEA as substrate with brain. The tricyclic antidepressant imipramine and nortriptyline inhibited B-form MAO activity more potency than B-form MAO in brain. However, when the noncyclic antidepressant nomifensine was used, monkey platelet B-form MAO activities were less potently inhibited. All these reagents were noncompetitive inhibitors of B form MAO in monkey platelet. The present studies demonstrated that monkey platelet MAO is a single of B-form MAO and sensitive to tricyclic antidepressants.

Effect of thyroid status on the development of the different molecular forms of Na+,K+-ATPase in rat brain.

PubMed

Atterwill, C K; Reid, J; Athayde, C M

1985-05-01

The effect of thyroid status on the postnatal development of the two molecular forms of Na+,K+-ATPase, distinguished kinetically on the basis of their ouabain sensitivity, was examined in rat brain. Hypothyroidism induced by PTU from day 1 postnatally significantly reduced the Na+,K+-ATPase activity in cerebellum (22-30 days) but not forebrain, whereas hyperthyroidism (T4 treatment from day 1) had no effect. The hypothyroidism-induced reduction in cerebellum was reflected by a 20-45% reduction in the activity of the alpha(+) form of Na+,K+-ATPase (high ouabain affinity) against control brains compared to a 60-70% reduction in the activity of the alpha form (low ouabain affinity). These results show that neonatally induced hypothyroidism leads to a selectively greater impairment of the ontogenesis of the activity of cerebellar alpha form of Na+,K+-ATPase. This may possibly reflect a retarded development of a selective cerebellar cell population containing predominantly the alpha form of the enzyme.

Effect of the mechanical activation of a cathode on the structure of electrolytic copper single crystals

NASA Astrophysics Data System (ADS)

Gryzunova, N. N.; Vikarchuk, A. A.; Gryzunov, A. M.; Denisova, A. G.

2017-10-01

The morphology of the electrolytic copper single crystals formed under the mechanical activation of a cathode is described. Pentagonal pyramids and conical microcrystals with high growth steps are shown to form during electrocrystallization under these conditions. It is experimentally found that microcrystals grow on disclination defects, in particular, at the sites of termination of twin growth boundaries, and mechanical activation causes the formation of such defects.

Application of a mixed metal oxide catalyst to a metallic substrate

NASA Technical Reports Server (NTRS)

Sevener, Kathleen M. (Inventor); Lohner, Kevin A. (Inventor); Mays, Jeffrey A. (Inventor); Wisner, Daniel L. (Inventor)

2009-01-01

A method for applying a mixed metal oxide catalyst to a metallic substrate for the creation of a robust, high temperature catalyst system for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in propulsion systems. The method begins by forming a prepared substrate material consisting of a metallic inner substrate and a bound layer of a noble metal intermediate. Alternatively, a bound ceramic coating, or frit, may be introduced between the metallic inner substrate and noble metal intermediate when the metallic substrate is oxidation resistant. A high-activity catalyst slurry is applied to the surface of the prepared substrate and dried to remove the organic solvent. The catalyst layer is then heat treated to bind the catalyst layer to the surface. The bound catalyst layer is then activated using an activation treatment and calcinations to form the high-activity catalyst system.

Functional Relevance of Protein Glycosylation to the Pro-Inflammatory Effects of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) on Monocytes/Macrophages

PubMed Central

Ge, Heng; Yuan, Wei; Liu, Jidong; He, Qing; Ding, Song; Pu, Jun; He, Ben

2015-01-01

Background and Objective Extracellular matrix metalloproteinase inducer (EMMPRIN) is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages. Methods The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells) in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway. Results 1) It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN) that increased after being exposed to inflammatory signals (PMA and H2O2). 2) Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG) the simple type. 3) Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression). Conclusions Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages. PMID:25658763

A high-throughput assay for DNA topoisomerases and other enzymes, based on DNA triplex formation.

PubMed

Burrell, Matthew R; Burton, Nicolas P; Maxwell, Anthony

2010-01-01

We have developed a rapid, high-throughput assay for measuring the catalytic activity (DNA supercoiling or relaxation) of topoisomerase enzymes that is also capable of monitoring the activity of other enzymes that alter the topology of DNA. The assay utilises intermolecular triplex formation to resolve supercoiled and relaxed forms of DNA, the principle being the greater efficiency of a negatively supercoiled plasmid to form an intermolecular triplex with an immobilised oligonucleotide than the relaxed form. The assay provides a number of advantages over the standard gel-based methods, including greater speed of analysis, reduced sample handling, better quantitation and improved reliability and accuracy of output data. The assay is performed in microtitre plates and can be adapted to high-throughput screening of libraries of potential inhibitors of topoisomerases including bacterial DNA gyrase.

Highly sensitive assay for tyrosine hydroxylase activity by high-performance liquid chromatography.

PubMed

Nagatsu, T; Oka, K; Kato, T

1979-07-21

A highly sensitive assay for tyrosine hydroxylase (TH) activity by high-performance liquid chromatography (HPLC) with amperometric detection was devised based on the rapid isolation of enzymatically formed DOPA by a double-column procedure, the columns fitted together sequentially (the top column of Amberlite CG-50 and the bottom column of aluminium oxide). DOPA was adsorbed on the second aluminium oxide column, then eluted with 0.5 M hydrochloric acid, and assayed by HPLC with amperometric detection. D-Tyrosine was used for the control. alpha-Methyldopa was added to the incubation mixture as an internal standard after incubation. This assay was more sensitive than radioassays and 5 pmol of DOPA formed enzymatically could be measured in the presence of saturating concentrations of tyrosine and 6-methyltetrahydropterin. The TH activity in 2 mg of human putamen could be easily measured, and this method was found to be particularly suitable for the assay of TH activity in a small number of nuclei from animal and human brain.

Conformational changes in human Hsp70 induced by high hydrostatic pressure produce oligomers with ATPase activity but without chaperone activity.

PubMed

Araujo, Thaís L S; Borges, Julio Cesar; Ramos, Carlos H; Meyer-Fernandes, José Roberto; Oliveira Júnior, Reinaldo S; Pascutti, Pedro G; Foguel, Debora; Palhano, Fernando L

2014-05-13

We investigated the folding of the 70 kDa human cytosolic inducible protein (Hsp70) in vitro using high hydrostatic pressure as a denaturing agent. We followed the structural changes in Hsp70 induced by high hydrostatic pressure using tryptophan fluorescence, molecular dynamics, circular dichroism, high-performance liquid chromatography gel filtration, dynamic light scattering, ATPase activity, and chaperone activity. Although monomeric, Hsp70 is very sensitive to hydrostatic pressure; after pressure had been removed, the protein did not return to its native sate but instead formed oligomeric species that lost chaperone activity but retained ATPase activity.

Effect of human serum albumin upon the permeabilizing activity of sticholysin II, a pore forming toxin from Stichodactyla heliantus.

PubMed

Celedón, Gloria; González, Gustavo; Gulppi, Felipe; Pazos, Fabiola; Lanio, María E; Alvarez, Carlos; Calderón, Cristian; Montecinos, Rodrigo; Lissi, Eduardo

2013-12-01

Sticholysin II (St II) is a haemolytic toxin isolated from the sea anemone Stichodactyla helianthus. The high haemolytic activity of this toxin is strongly dependent on the red cell status and the macromolecule conformation. In the present communication we evaluate the effect of human serum albumin on St II haemolytic activity and its capacity to form pores in the bilayer of synthetic liposomes. St II retains its pore forming capacity in the presence of large concentrations (up to 500 μM) of human serum albumin. This effect is observed both in its capacity to produce red blood cells haemolysis and to generate functional pores in liposomes. In particular, the capacity of the toxin to lyse red blood cells increases in the presence of human serum albumin (HSA). Regarding the rate of the pore forming process, it is moderately decreased in liposomes and in red blood cells, in spite of an almost total coverage of the interface by albumin. All the data obtained in red cells and model membranes show that St II remains lytically active even in the presence of high HSA concentrations. This stubbornness can explain why the toxin is able to exert its haemolytic activity on membranes immersed in complex plasma matrixes such as those present in living organisms.

Gullies Old and New Near the Argyre Region

NASA Image and Video Library

2015-01-28

This image from NASA Mars Reconnaissance Orbiter shows several seemingly active gullies and their associated fans near the Argyre region. As gullies form on slopes, sediment can become deposited to form lobe-shaped fans. Gullies can form with flowing water, but don't have to: sometimes they can be formed by the dry flow of sand and dust grains. This HiRISE image shows several seemingly active gullies and their associated fans. These particular gullies have many fine channels that are resolved nicely with a high resolution image. http://photojournal.jpl.nasa.gov/catalog/PIA19286

PROCESS FOR THE PRODUCTION OF AN ACTIVATED FORM OF UO$sub 2$

DOEpatents

Polissar, M.J.

1957-09-24

A process for producing a highly active form of UO/sub 2/ characterized both by rapid oxidation in air and by rapid chlorination with CCl/sub 4/ vapor at an elevated temperature is reported. In accordance with the process, commercial UO/sub 2/, is subjected to a series of oxidation-reduction operations to produce a form of UC/sub 2/ of enhanced reactivity. By treatimg commercial UO/sub 2/ at a temperature between 335 and 485 deg C with methane, then briefly with an oxygen containing gas and followimg this by a second treatment with a methane containing gas, the original relatively stable charge of UO/sub 2/ will be transformed into an active form of UO/sub 2/.

pH effects on the hyaluronan hydrolysis catalysed by hyaluronidase in the presence of proteins: Part I. Dual aspect of the pH-dependence.

PubMed

Lenormand, Hélène; Deschrevel, Brigitte; Vincent, Jean-Claude

2010-05-01

Hyaluronan (HA) hydrolysis catalysed by hyaluronidase (HAase) is strongly inhibited when performed at a low ratio of HAase to HA concentrations and at low ionic strength. This is because long HA chains can form non-active complexes with HAase. Bovine serum albumin (BSA) is able to compete with HAase to form electrostatic complexes with HA so freeing HAase which then recovers its catalytic activity. This BSA-dependence is characterised by two main domains separated by the optimal BSA concentration: below this concentration the HAase activity increases when the BSA concentration is increased, above this concentration the HAase activity decreases. This occurs provided that HA is negatively charged and BSA is positively charged, i.e. in a pH range from 3 to 5.25. The higher the pH value the higher the optimal BSA concentration. Other proteins can also modulate HAase activity. Lysozyme, which has a pI higher than that of BSA, is also able to compete with HAase to form electrostatic complexes with HA and liberate HAase. This occurs over a wider pH range that extends from 3 to 9. These results mean that HAase can form complexes with HA and recover its enzymatic activity at pH as high as 9, consistent with HAase having either a high pI value or positively charged patches on its surface at high pH. Finally, the pH-dependence of HAase activity, which results from the influence of pH on both the intrinsic HAase activity and the formation of complexes between HAase and HA, shows a maximum at pH 4 and a significant activity up to pH 9. Copyright 2009 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Intracellular proteolysis of pancreatic zymogens.

PubMed Central

Gorelick, F. S.; Modlin, I. M.; Leach, S. D.; Carangelo, R.; Katz, M.

1992-01-01

Activation of pancreatic digestive zymogens within the pancreatic acinar cell may be an early event in the development of pancreatitis. To detect such activation, an immunoblot assay has been developed that measures the relative amounts of inactive zymogens and their respective active enzyme forms. Using this assay, high doses of cholecystokinin or carbachol were found to stimulate the intracellular conversion of at least three zymogens (procarboxypeptidase A1, procarboxypeptidase B, and chymotrypsinogen 2) to their active forms. Thus, this conversion may be a generalized phenomenon of pancreatic zymogens. The conversion is detected within ten minutes of treatment and is not associated with changes in acinar cell morphology; it has been predicted that the lysosomal thiol protease, cathepsin B, may initiate this conversion. Small amounts of cathepsin B are found in the secretory pathway, and cathepsin B can activate trypsinogen in vitro; however, exposure of acini to a thiol protease inhibitor (E64) did not block this conversion. Conversion was inhibited by the serine protease inhibitor, benzamidine, and by raising the intracellular pH, using chloroquine or monensin. This limited proteolytic conversion appears to require a low pH compartment and a serine protease activity. After long periods of treatment (60 minutes), the amounts of the active enzyme forms began to decrease; this observation suggested that the active enzyme forms were being degraded. Treatment of acini with E64 reduced this late decrease in active enzyme forms, suggesting that thiol proteases, including lysosomal hydrolases, may be involved in the degradation of the active enzyme forms. These findings indicate that pathways for zymogen activation as well as degradation of active enzyme forms are present within the pancreatic acinar cell. Images FIG. 1 FIG. 6 PMID:1340058

Electrically conducting ternary amorphous fully oxidized materials and their application

NASA Technical Reports Server (NTRS)

Giauque, Pierre (Inventor); Nicolet, Marc (Inventor); Gasser, Stefan M. (Inventor); Kolawa, Elzbieta A. (Inventor); Cherry, Hillary (Inventor)

2004-01-01

Electrically active devices are formed using a special conducting material of the form Tm--Ox mixed with SiO2 where the materials are immiscible. The immiscible materials are forced together by using high energy process to form an amorphous phase of the two materials. The amorphous combination of the two materials is electrically conducting but forms an effective barrier.

Forming system of strategic innovation management at high-tech engineering enterprises

NASA Astrophysics Data System (ADS)

Ergunova, O. T.; Lizunkov, V. G.; Malushko, E. Yu; Marchuk, V. I.; Ignatenko, A. Yu

2017-02-01

The article considers the processes of forming the strategic system of innovative activity management at the enterprises of a high-tech mechanical engineering complex (MEC) that are traditionally decisive in shaping the economic base of Russia. The authors proposed a method of designing a strategic system of innovative activity management at the MEC’s enterprises of the region which is based on the consideration of means and opportunities of the enterprise to implement intellectual activity. The proposed methodology and the empirical results constituted a ground for developing a system of strategic innovation management when performing the state-guaranteed order at the hi-tech MEC enterprises. Its implementation will help to reduce the level of uncertainty throughout the entire life cycle of an innovative activity product.

The International Physical Activity Questionnaire-long form overestimates self-reported physical activity of Brazilian adults.

PubMed

Sebastião, E; Gobbi, S; Chodzko-Zajko, W; Schwingel, A; Papini, C B; Nakamura, P M; Netto, A V; Kokubun, E

2012-11-01

To explore issues associated with measuring physical activity using the International Physical Activity Questionnaire (IPAQ)-long form in adults living in a mid-sized Brazilian city. A stratified random sampling procedure was used to select a representative sample of adults living in Rio Claro. This yielded 1572 participants who were interviewed using the IPAQ-long form. The data were analysed using standard statistical procedures. Overall, 83% of men and 89% of women reported at least 150 min of combined moderate and/or vigorous physical activity per week. Reliable values of leisure and transportation-related physical activity were observed for both males and females. With regard to the household and work-related physical activity domains, both males and females reported unusually high levels of participation. The IPAQ-long form appears to overestimate levels of physical activity for both males and females, suggesting that the instrument has problems in measuring levels of physical activity in Brazilian adults. Accordingly, caution is warranted before using IPAQ data to support public policy decisions related to physical activity. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Films of Bacteria at Interfaces (FBI): Remodeling of Fluid Interfaces by Pseudomonas aeruginosa.

PubMed

Niepa, Tagbo H R; Vaccari, Liana; Leheny, Robert L; Goulian, Mark; Lee, Daeyeon; Stebe, Kathleen J

2017-12-19

Bacteria at fluid interfaces endure physical and chemical stresses unique to these highly asymmetric environments. The responses of Pseudomonas aeruginosa PAO1 and PA14 to a hexadecane-water interface are compared. PAO1 cells form elastic films of bacteria, excreted polysaccharides and proteins, whereas PA14 cells move actively without forming an elastic film. Studies of PAO1 mutants show that, unlike solid-supported biofilms, elastic interfacial film formation occurs in the absence of flagella, pili, or certain polysaccharides. Highly induced genes identified in transcriptional profiling include those for putative enzymes and a carbohydrate metabolism enzyme, alkB2; this latter gene is not upregulated in PA14 cells. Notably, PAO1 mutants lacking the alkB2 gene fail to form an elastic layer. Rather, they form an active film like that formed by PA14. These findings demonstrate that genetic expression is altered by interfacial confinement, and suggest that the ability to metabolize alkanes may play a role in elastic film formation at oil-water interfaces.

Highly dispersed buckybowls as model carbocatalysts for C–H bond activation

DOE PAGES

Soykal, I. Ilgaz; Wang, Hui; Park, Jewook; ...

2015-03-19

Buckybowl fractions dispersed on mesoporous silica constitute an ideal model for studying the catalysis of graphitic forms of carbon since the dispersed carbon nanostructures contain a high ratio of edge defects and curvature induced by non-six-membered rings. Dispersion of the active centers on an easily accessible high surface area material allowed for high density of surface active sites associated with oxygenated structures. This report illustrates a facile method of creating model polycyclic aromatic nano-structures that are not only active for alkane C-H bond activation and oxidative dehydrogenation but also can be practical catalysts to be eventually used in industry.

High Molecular Weight Complex Analysis of Epstein-Barr Virus Latent Membrane Protein 1 (LMP-1): Structural Insights into LMP-1’s Homo-Oligomerization and Lipid Raft Association

PubMed Central

Wrobel, Christopher M.; Geiger, Timothy R.; Nix, Rebecca N.; Robitaille, Aaron M.; Balser, Sandra; Cervantes, Alfredo; Gonzalez, Miguel; Martin, Jennifer M.

2013-01-01

LMP-1 is a constitutively active Tumor Necrosis Factor Receptor analog encoded by Epstein-Barr virus. LMP-1 activation correlates with oligomerization and raft localization, but direct evidence of LMP-1 oligomers is limited. We report that LMP-1 forms multiple high molecular weight native LMP-1 complexes when analyzed by BN-PAGE, the largest of which are enriched in detergent resistant membranes. The largest of these high molecular weight complexes are not formed by purified LMP-1 or by loss of function LMP-1 mutants. Consistent with these results we find a dimeric form of LMP-1 that can be stabilized by disulfide crosslinking. We identify cysteine 238 in the C-terminus of LMP-1 as the crosslinked cysteine. Disulfide crosslinking occurs post-lysis but the dimer can be crosslinked in intact cells with membrane permeable crosslinkers. LMP-1/C238A retains wild type LMP-1 NF-κB activity. LMP-1’s TRAF binding, raft association and oligomerization are associated with the dimeric form of LMP-1. Our results suggest the possibility that the observed dimeric species results from inter-oligomeric crosslinking of LMP-1 molecules in adjacent core LMP-1 oligomers. PMID:24075898

High-throughput microtitre plate-based assay for DNA topoisomerases.

PubMed

Taylor, James A; Burton, Nicolas P; Maxwell, Anthony

2012-01-01

We have developed a rapid, high-throughput assay for measuring the catalytic activity (DNA supercoiling or relaxation) of DNA topoisomerases. The assay utilizes intermolecular triplex formation between an immobilized triplex-forming oligo (TFO) and a triplex-forming region inserted into the plasmid substrate (pNO1), and capitalizes on the observation that supercoiled DNA forms triplexes more readily than relaxed DNA. Thus, supercoiled DNA is preferentially retained by the TFO under triplex-forming conditions while relaxed DNA can be washed away. Due to its high speed of sample analysis and reduced sample handling over conventional gel-based techniques, this assay can be used to screen chemical libraries for novel inhibitors of topoisomerases.

Starch Applications for Delivery Systems

NASA Astrophysics Data System (ADS)

Li, Jason

2013-03-01

Starch is one of the most abundant and economical renewable biopolymers in nature. Starch molecules are high molecular weight polymers of D-glucose linked by α-(1,4) and α-(1,6) glycosidic bonds, forming linear (amylose) and branched (amylopectin) structures. Octenyl succinic anhydride modified starches (OSA-starch) are designed by carefully choosing a proper starch source, path and degree of modification. This enables emulsion and micro-encapsulation delivery systems for oil based flavors, micronutrients, fragrance, and pharmaceutical actives. A large percentage of flavors are encapsulated by spray drying in today's industry due to its high throughput. However, spray drying encapsulation faces constant challenges with retention of volatile compounds, oxidation of sensitive compound, and manufacturing yield. Specialty OSA-starches were developed suitable for the complex dynamics in spray drying and to provide high encapsulation efficiency and high microcapsule quality. The OSA starch surface activity, low viscosity and film forming capability contribute to high volatile retention and low active oxidation. OSA starches exhibit superior performance, especially in high solids and high oil load encapsulations compared with other hydrocolloids. The submission is based on research and development of Ingredion

Two-electron Reduction versus One-electron Oxidation of the Type 3 Pair in the Multicopper Oxidases

PubMed Central

Kjaergaard, Christian H.; Jones, Stephen M.; Gounel, Sébastien; Mano, Nicolas; Solomon, Edward I.

2015-01-01

Multicopper Oxidases (MCOs) utilize an electron shuttling Type 1 Cu (T1) site in conjunction with a mononuclear Type 2 (T2) and a binuclear Type 3 (T3) site, arranged in a trinuclear copper cluster (TNC), to reduce O2 to H2O. Reduction of O2 occurs with limited overpotential indicating that all the coppers in the active site can be reduced via high-potential electron donors. Two forms of the resting enzyme have been observed in MCOs: the Alternative Resting form (AR), where only one of the three TNC Cu’s is oxidized, and the Resting Oxidized form (RO), where all three TNC Cu’s are oxidized. In contrast to the AR form, we show that in the RO form of a high-potential MCO, the binuclear T3 Cu(II) site can be reduced via the 700 mV T1 Cu. Systematic spectroscopic evaluation reveals that this proceeds by a two-electron process, where delivery of the first electron, forming a high energy, meta-stable half reduced T3 state, is followed by the rapid delivery of a second energetically favorable electron to fully reduce the T3 site. Alternatively, when this fully reduced binuclear T3 site is oxidized via the T1 Cu, a different thermodynamically favored half oxidized T3 form, i.e. the AR site, is generated. This behavior is evaluated by DFT calculations, which reveal that the protein backbone plays a significant role in controlling the environment of the active site coppers. This allows for the formation of the meta-stable, half reduced state and thus the complete reductive activation of the enzyme for catalysis. PMID:26075678

Basic aminopeptidase activity is an emerging biomarker in collagen-induced rheumatoid arthritis.

PubMed

Mendes, Mariana Trivilin; Murari-do-Nascimento, Stephanie; Torrigo, Isis Rossetti; Alponti, Rafaela Fadoni; Yamasaki, Simone Cristina; Silveira, Paulo Flavio

2011-04-11

The objective of this study was to investigate the catalytic activity of basic aminopeptidase (APB) and its association with periarticular edema and circulating tumor necrosis factor (TNF)-alpha and type II collagen (CII) antibodies (AACII) in a rat model of rheumatoid arthritis (RA) induced by CII (CIA). Edema does not occur in part of CII-treated, even when AACII is higher than in control. TNF-alpha is detectable only in edematous CII-treated. APB in synovial membrane is predominantly a membrane-bound activity also present in soluble form and with higher activity in edematous than in non-edematous CII-treated or control. Synovial fluid and blood plasma have lower APB in non-edematous than in edematous CII-treated or control. In peripheral blood mononuclear cells (PBMCs) the highest levels of APB are found in soluble form in control and in membrane-bound form in non-edematous CII-treated. CII treatment distinguishes two categories of rats: one with arthritic edema, high AACII, detectable TNF-alpha, high soluble and membrane-bound APB in synovial membrane and low APB in the soluble fraction of PBMCs, and another without edema and with high AACII, undetectable TNF-alpha, low APB in the synovial fluid and blood plasma and high APB in the membrane-bound fraction of PBMCs. Data suggest that APB and CIA are strongly related. 2011 Elsevier B.V. All rights reserved.

Abnormal factor VIII coagulant antigen in patients with renal dysfunction and in those with disseminated intravascular coagulation.

PubMed Central

Weinstein, M J; Chute, L E; Schmitt, G W; Hamburger, R H; Bauer, K A; Troll, J H; Janson, P; Deykin, D

1985-01-01

Factor VIII antigen (VIII:CAg) exhibits molecular weight heterogeneity in normal plasma. We have compared the relative quantities of VIII:CAg forms present in normal individuals (n = 22) with VIII:CAg forms in renal dysfunction patients (n = 19) and in patients with disseminated intravascular coagulation (DIC; n = 7). In normal plasma, the predominant VIII: CAg form, detectable by sodium dodecyl sulfate polyacrylamide gel electrophoresis, was of molecular weight 2.4 X 10(5), with minor forms ranging from 8 X 10(4) to 2.6 X 10(5) D. A high proportion of VIII:CAg in renal dysfunction patients, in contrast, was of 1 X 10(5) mol wt. The patients' high 1 X 10(5) mol wt VIII: CAg level correlated with increased concentrations of serum creatinine, F1+2 (a polypeptide released upon prothrombin activation), and with von Willebrand factor. Despite the high proportion of the 1 X 10(5) mol wt VIII:CAg form, which suggests VIII:CAg proteolysis, the ratio of Factor VIII coagulant activity to total VIII:CAg concentration was normal in renal dysfunction patients. These results could be simulated in vitro by thrombin treatment of normal plasma, which yielded similar VIII:CAg gel patterns and Factor VIII coagulant activity to antigen ratios. DIC patients with high F1+2 levels but no evidence of renal dysfunction had an VIII:CAg gel pattern distinct from renal dysfunction patients. DIC patients had elevated concentrations of both the 1 X 10(5) and 8 X 10(4) mol wt VIII:CAg forms. We conclude that an increase in a particular VIII:CAg form correlates with the severity of renal dysfunction. The antigen abnormality may be the result of VIII:CAg proteolysis by a thrombinlike enzyme and/or prolonged retention of proteolyzed VIII:CAg fragments. Images PMID:3932466

Dynamic Perturbation of the Active Site Determines Reversible Thermal Inactivation in Glycoside Hydrolase Family 12.

PubMed

Jiang, Xukai; Li, Wen; Chen, Guanjun; Wang, Lushan

2017-02-27

The temperature dependence of enzyme catalysis is highly debated. Specifically, how high temperatures induce enzyme inactivation has broad implications for both fundamental and applied science. Here, we explored the mechanism of the reversible thermal inactivation in glycoside hydrolase family 12 (GH12) using comparative molecular dynamics simulations. First, we investigated the distribution of structural flexibility over the enzyme and found that the active site was the general thermal-sensitive region in GH12 cellulases. The dynamic perturbation of the active site before enzyme denaturation was explored through principal-component analysis, which indicated that variations in the collective motion and conformational ensemble of the active site may precisely correspond to enzyme transition from its active form to the inactive form. Furthermore, the degree of dynamic perturbation of the active site was found to be negatively correlated with the melting temperatures of GH12 enzymes, further proving the importance of the dynamic stability of the active site. Additionally, analysis of the residue-interaction network revealed that the active site in thermophilic enzyme was capable of forming additional contacts with other amino acids than those observed in the mesophilic enzyme. These interactions are likely the key mechanisms underlying the differences in rigidity of the active site. These findings provide further biophysical insights into the reversible thermal inactivation of enzymes and potential applications in future protein engineering.

Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants

PubMed Central

Llauro, Christel; Jobet, Edouard; Robakowska-Hyzorek, Dagmara; Lasserre, Eric; Ghesquière, Alain; Panaud, Olivier

2017-01-01

Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA) forms of active retrotransposons to characterize the repertoire of mobile retrotransposons in plants. This method successfully identified known active retrotransposons in both Arabidopsis and rice material where the epigenome is destabilized. When applying mobilome-seq to developmental stages in wild type rice, we identified PopRice as a highly active retrotransposon producing eccDNA forms in the wild type endosperm. The mobilome-seq strategy opens new routes for the characterization of a yet unexplored fraction of plant genomes. PMID:28212378

Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants.

PubMed

Lanciano, Sophie; Carpentier, Marie-Christine; Llauro, Christel; Jobet, Edouard; Robakowska-Hyzorek, Dagmara; Lasserre, Eric; Ghesquière, Alain; Panaud, Olivier; Mirouze, Marie

2017-02-01

Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA) forms of active retrotransposons to characterize the repertoire of mobile retrotransposons in plants. This method successfully identified known active retrotransposons in both Arabidopsis and rice material where the epigenome is destabilized. When applying mobilome-seq to developmental stages in wild type rice, we identified PopRice as a highly active retrotransposon producing eccDNA forms in the wild type endosperm. The mobilome-seq strategy opens new routes for the characterization of a yet unexplored fraction of plant genomes.

A mechanism for the activation of the Na/H exchanger NHE-1 by cytoplasmic acidification and mitogens

PubMed Central

Lacroix, Jérôme; Poët, Mallorie; Maehrel, Céline; Counillon, Laurent

2004-01-01

Eukaryotic cells constantly have to fight against internal acidification. In mammals, this task is mainly performed by the ubiquitously expressed electroneutral Na+/H+ exchanger NHE-1, which activates in a cooperative manner when cells become acidic. Despite its biological importance, the mechanism of this activation is still poorly understood, the most commonly accepted hypothesis being the existence of a proton-sensor site on the internal face of the transporter. This work uncovers mutations that lead to a nonallosteric form of the exchanger and demonstrates that NHE-1 activation is best described by a Monod–Wyman–Changeux concerted mechanism for a dimeric transporter. During intracellular acidification, a low-affinity form of NHE-1 is converted into a form possessing a higher affinity for intracellular protons, with no requirement for an additional proton-sensor site on the protein. This new mechanism also explains the activation of the exchanger by growth signals, which shift the equilibrium towards the high-affinity form. PMID:14710192

Updated Liquid Secondary Waste Grout Formulation and Preliminary Waste Form Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saslow, Sarah A.; Um, Wooyong; Russell, Renee L.

This report describes the results from liquid secondary waste grout (LSWG) formulation and cementitious waste form qualification tests performed by Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions, LLC (WRPS). New formulations for preparing a cementitious waste form from a high-sulfate liquid secondary waste stream simulant, developed for Effluent Management Facility (EMF) process condensates merged with low activity waste (LAW) caustic scrubber, and the release of key constituents (e.g. 99Tc and 129I) from these monoliths were evaluated. This work supports a technology development program to address the technology needs for Hanford Site Effluent Treatment Facility (ETF) liquid secondarymore » waste (LSW) solidification and supports future Direct Feed Low-Activity Waste (DFLAW) operations. High-priority activities included simulant development, LSWG formulation, and waste form qualification. The work contained within this report relates to waste form development and testing and does not directly support the 2017 integrated disposal facility (IDF) performance assessment (PA). However, this work contains valuable information for use in PA maintenance past FY17, and for future waste form development efforts. The provided data should be used by (i) cementitious waste form scientists to further understanding of cementitious dissolution behavior, (ii) IDF PA modelers who use quantified constituent leachability, effective diffusivity, and partitioning coefficients to advance PA modeling efforts, and (iii) the U.S. Department of Energy (DOE) contractors and decision makers as they assess the IDF PA program. The results obtained help fill existing data gaps, support final selection of a LSWG waste form, and improve the technical defensibility of long-term waste form performance estimates.« less

Liquid-permeable electrode

DOEpatents

Folser, George R.

1980-01-01

Electrodes for use in an electrolytic cell, which are liquid-permeable and have low electrical resistance and high internal surface area are provided of a rigid, porous, carbonaceous matrix having activated carbon uniformly embedded throughout. The activated carbon may be catalyzed with platinum for improved electron transfer between electrode and electrolyte. Activated carbon is mixed with a powdered thermosetting phenolic resin and compacted to the desired shape in a heated mold to melt the resin and form the green electrode. The compact is then heated to a pyrolyzing temperature to carbonize and volatilize the resin, forming a rigid, porous structure. The permeable structure and high internal surface area are useful in electrolytic cells where it is necessary to continuously remove the products of the electrochemical reaction.

Risk factors in adolescence: the case of gambling, videogame playing, and the internet.

PubMed

Griffiths, M; Wood, R T

2000-01-01

It has been noted that adolescents may be more susceptible to pathological gambling. Not only is it usually illegal, but it appears to be related to high levels of problem gambling and other delinquent activities such as illicit drug taking and alcohol abuse. This paper examines risk factors not only in adolescent gambling but also in videogame playing (which shares many similarities with gambling). There appear to be three main forms of adolescent gambling that have been widely researched. Adolescent gambling activities and general risk factors in adolescent gambling are provided. As well, the influence of technology on adolescents in the form of both videogames and the Internet are examined. It is argued that technologically advanced forms of gambling may be highly appealing to adolescents.

Current status of the thiol redox model for the regulation of hexose transport by insulin.

PubMed

Czech, M P

1976-12-01

Data obtained over the last two years pertinent to the thiol redox model for the modulation of hexose transport activity by insulin is summarized. The model proposes that activation of hexose transport in fat cells involves sulfhydryl oxidation to the disulfide form in a key protein component of the fat cell surface membrane. Theoretically, the rapid activation of transport by insulin may involve either the conversion of inactive membrane carriers to the active form as originally proposed, or the conversion of a low Vmax transport system to a high Vmax form. The present experiments showed that the percent inhibition of insulin-activated transport rates by submaximal levels of cytochalasin B was decreased compared to its effects on basal transport. Treatment of fat cells with N-ethylmaleimide inhibited cytochalasin B action but not transport activity. When insulin or the oxidant vitamin K5 was added to cells 5 minutes before the N-ethylmaleimide, the elevated transport activity was also resistant to the sulfhydryl reagent, but cytochalasin B retained its potent inhibitory effect on transport. The data demonstrate that unique properties characterize basal versus insulin-activated transport activity with respect to the sensitivity of cytochalasin B action to sulfhydryl blockade in isolated fat cells. The data are consistent with the concept that activation of transport activity reflects the conversion of a reduced (sulfhydryl) system characterized by a low Vmax to an oxidized (disulfide), high Vmax transport system.

Selective advantages of two major clones of carbapenem-resistant Pseudomonas aeruginosa isolates (CC235 and CC641) from Korea: antimicrobial resistance, virulence and biofilm-forming activity.

PubMed

Lee, Ji-Young; Peck, Kyong Ran; Ko, Kwan Soo

2013-07-01

The characteristics of carbapenem-resistant P. aeruginosa (CRPA) isolates from Korea were investigated. Two major clones, clonal complex (CC) 235 and CC641, were identified. CC235, an important international clone, might have been imported recently in Korea as this clone displayed a homogeneous genotype, oprD mutation and antimicrobial resistance profile. While 13 ST235 isolates harboured the blaIMP-6 gene, which conferred high-level meropenem resistance, CC641 isolates showed high biofilm-forming activity. CC235 and CC641 isolates showed distinct distribution of ferripyoverdine receptor type and virulence markers. While all CC235 isolates were of the fpvAIIb type and exoS(-)/exoU(+), CC641 isolates were exoS(+)/exoU(-), and all but one showed the fpvAIII type. CC235 and CC641 isolates were also characterized by different extracellular protease activity: staphylolysin and elastase activities in CC235 and CC641, respectively. Two major CRPA clones in Korea seem to be predominant, reflecting their selective advantage by virtue of antimicrobial resistance, virulence and biofilm-forming activity.

[A DNA study of rat liver oligonucleosomes enriched by transcriptionally active genes during induction due to the administration of an amino acid mixture].

PubMed

Vardevanian, P O; Davtian, A M; Tiratsuian, S G; Vardevanian, A O

1990-01-01

A highly active fraction of rat liver oligonucleosome DNA has been isolated and studied by means of thermal denaturation after induction by amino acid mixture or hydrocortisone. A considerable redistribution of DNA content has been shown in sucrose gradient fractions during these forms of induction. The changes are revealed in melting temperature, differential melting profile of DNA, isolated from actively transcribed chromatine fractions. Analysis of melting profiles shows changes of GC content of oligonucleosome DNA, suggesting that there are differences in activation during two studied forms of induction.

Adhesive Properties and Acid-Forming Activity of Lactobacilli and Streptococci Under Inhibitory Substances, Such as Nitrates.

PubMed

Hakobyan, L; Harutyunyan, K; Harutyunyan, N; Melik-Andreasyan, G; Trchounian, A

2016-06-01

One of the main requirements for probiotics is their ability to survive during passage through gastrointestinal tract and to maintain their activity at different adverse conditions. The aim of the study was to look for the strains of lactobacilli and streptococci with high adhesive properties even affected by inhibitory substances, such as nitrates (NO3 (-)). To study the adhesion properties hemagglutination reaction of bacterial cells with red blood cells of different animals and humans was used. The acid formation ability of bacteria was determined by the method of titration after 7 days of incubation in the sterile milk. These properties were investigated at different concentrations of NO3 (-). The high concentration (mostly ≥2.0 %) NO3 (-) inhibited the growth of both lactobacilli and streptococci, but compared with streptococcal cultures lactobacilli, especially Lactobacillus acidophilus Ep 317/402, have shown more stability and higher adhesive properties. In addition, the concentrations of NO3 (-) of 0.5-2.0 % decreased the acid-forming activity of the strains, but even under these conditions they coagulated milk and, in comparison to control, formed low acidity in milk. Thus, the L. acidophilus Ep 317/402 with high adhesive properties has demonstrated a higher activity of NO3 (-) transformation.

The relationship between the content and the form of metaphorical statements.

PubMed

Xu, Xu

2010-04-01

Recent research suggests that the quality of a metaphorical topic-vehicle pairing should be the determinant to the choice of a proper grammatical form, nominal metaphor versus simile. Two studies examined the relationship between the quality of the content of a metaphorical statement and its grammatical form. Study 1 showed that the two grammatical forms did not differ in aptness when the quality of topic-vehicle pairs and the conventionality of vehicles, a factor associated with the quality of metaphorical expressions, were controlled. With an online comprehension measure, Study 2 found that high quality metaphorical pairings were easier to process than low quality metaphorical pairings in both the metaphor form and the simile form. For high quality metaphorical pairings, information related to both the topics and the vehicles was highly activated at an early stage of processing. The relations among factors involved in the interpretive process of metaphorical language are discussed.

Study on photoemission surface of varied doping GaN photocathode

NASA Astrophysics Data System (ADS)

Qiao, Jianliang; Du, Ruijuan; Ding, Huan; Gao, Youtang; Chang, Benkang

2014-09-01

For varied doping GaN photocathode, from bulk to surface the doping concentrations are distributed from high to low. The varied doping GaN photocathode may produce directional inside electric field within the material, so the higher quantum efficiency can be obtained. The photoemission surface of varied doping GaN photocathode is very important to the high quantum efficiency, but the forming process of the surface state after Cs activation or Cs/O activation has been not known completely. Encircling the photoemission mechanism of varied GaN photocathode, considering the experiment phenomena during the activation and the successful activation results, the varied GaN photocathode surface model [GaN(Mg):Cs]:O-Cs after activation with cesium and oxygen was given. According to GaN photocathode activation process and the change of electronic affinity, the comparatively ideal NEA property can be achieved by Cs or Cs/O activation, and higher quantum efficiency can be obtained. The results show: The effective NEA characteristic of GaN can be gotten only by Cs. [GaN(Mg):Cs] dipoles form the first dipole layer, the positive end is toward the vacuum side. In the activation processing with Cs/O, the second dipole layer is formed by O-Cs dipoles, A O-Cs dipole includes one oxygen atom and two Cs atoms, and the positive end is also toward the vacuum side thus the escape of electrons can be promoted.

Mechanistically Driven Development of Iridium Catalysts for Asymmetric Allylic Substitution

PubMed Central

Hartwig, John F.; Stanley, Levi M.

2010-01-01

Conspectus Enantioselective allylic substitution reactions comprise some of the most versatile methods for preparing enantiomerically enriched materials. These reactions form products that contain multiple functionalities by creating carbon–nitrogen, carbon–oxygen, carbon–carbon, and carbon–sulfur bonds. For many years, the development of catalysts for allylic substitution focused on palladium complexes. However, studies of complexes of other metals have revealed selectivities that often complement those of palladium systems. Most striking is the observation that reactions with unsymmetrical allylic electrophiles that typically occur with palladium catalysts at the less hindered site of an allylic electrophile occur at the more hindered site with catalysts based on other metals. In this Account, we describe an iridium precursor and a phosphoramidite ligand that catalyze reactions with a particularly broad scope of nucleophiles. The active form of this iridium catalyst is not generated by the simple binding of the phosphoramidite ligand to the metal precursor. Instead, the initial phosphoramidite and iridium precursor react in the presence of base to form a metallacyclic species that is the active catalyst. This species is generated either in situ or separately in isolated form by reactions with added base. The identification of the structure of the active catalyst led to the development of simplified catalysts as well as the most active form of the catalyst now available, which is stabilized by a loosely bound ethylene. Most recently, this structure was used to prepare intermediates containing allyl ligands, the structures of which provide a model for the enantioselectivities discussed here. Initial studies from our laboratory on the scope of iridium-catalyzed allylic substitution showed that reactions of primary and secondary amines, including alkylamines, benzylamines, and allylamines, and reactions of phenoxides and alkoxides occurred in high yields, with high branched-to-linear ratios and high enantioselectivities. Parallel mechanistic studies had revealed the metallacyclic structure of the active catalyst, and subsequent experiments with the purposefully formed metallacycle increased the reaction scope dramatically. Aromatic amines, azoles, ammonia, and amides and carbamates as ammonia equivalents all reacted with high selectivities and yields. Moreover, weakly basic enolates (such as silyl enol ethers) and enolate equivalents (such as enamines) also reacted, and other research groups have used this catalyst to conduct reactions of stabilized carbon nucleophiles in the absence of additional base. One hallmark of the reactions catalyzed by this iridium system is the invariably high enantioselectivity, which reflects a high stereoselectivity for formation of the allyl intermediate. Enantioselectivity typically exceeds 95%, regioselectivity for formation of branched over linear products is usually near 20:1, and yields generally exceed 75% and are often greater than 90%. Thus, the development of iridium catalysts for enantioselective allylic substitution shows how studies of reaction mechanism can lead to a particularly active and a remarkably general system for an enantioselective process. In this case, a readily accessible catalyst effects allylic substitution, with high enantioselectivity and regioselectivity complementary to that of the venerable palladium systems. PMID:20873839

Molecular architectures and functions of radical enzymes and their (re)activating proteins.

PubMed

Shibata, Naoki; Toraya, Tetsuo

2015-10-01

Certain proteins utilize the high reactivity of radicals for catalysing chemically challenging reactions. These proteins contain or form a radical and therefore named 'radical enzymes'. Radicals are introduced by enzymes themselves or by (re)activating proteins called (re)activases. The X-ray structures of radical enzymes and their (re)activases revealed some structural features of these molecular apparatuses which solved common enigmas of radical enzymes—i.e. how the enzymes form or introduce radicals at the active sites, how they use the high reactivity of radicals for catalysis, how they suppress undesired side reactions of highly reactive radicals and how they are (re)activated when inactivated by extinction of radicals. This review highlights molecular architectures of radical B12 enzymes, radical SAM enzymes, tyrosyl radical enzymes, glycyl radical enzymes and their (re)activating proteins that support their functions. For generalization, comparisons of the recently reported structures of radical enzymes with those of canonical radical enzymes are summarized here. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Review of cyclotron production and quality control of ``High specific activity'' radionuclides for biomedical, biological, industrial and environmental applications at INFN-LASA

NASA Astrophysics Data System (ADS)

Birattari, C.; Bonardi, M.; Groppi, F.; Gini, L.

2001-12-01

At the "Radiochemistry Laboratory" of Accelerators and Applied Superconductivity Laboratory, LASA, a wide range of high specific activity radionuclides, RNs, have been produced in No Carrier Added form, for both basic research and application purposes. Use was made of the AVF proton cyclotron (K=45) of Milan University (up to 1987). More recently, the irradiations were carried out at the Scanditronix MC40 cyclotron (K=38; p, d, He-4 and He-3) of JRC-Ispra, Italy, of the European Community. In order to optimize the irradiation conditions for radioisotope production, a series of thin- and thick-target excitation functions have been experimentally determined. For each RN, a specific radiochemical separation has been developed in order to obtain GBq (mCi) amounts of the radiotracers in "high specific activity" No Carrier Added form (NCA).

Single marker identification of head and neck squamous cell carcinoma cancer stem cells with aldehyde dehyrdrogenase

PubMed Central

Clay, MR.; Tabor, M.; Owen, J.; Carey, TE.; Bradford, CR.; Wolf, GT.; Wicha, MS.; Prince, ME.

2010-01-01

Background According to the cancer stem cell (CSC) theory only a small subset of cancer cells are capable of forming tumors. We previously reported that CD44 isolates tumorigenic cells from HNSCC. Recent studies indicate that aldehyde dehydrogenase (ALDH) activity may represent a more specific marker of CSCs. Methods Six primary HNSCC were collected. Cells with high and low ALDH activity (ALDHhigh/ALDHlow) were isolated. ALDHhigh and ALDHlow populations were implanted into NOD/SCID mice and monitored for tumor development. Results ALDHhigh cells represented a small percentage of the tumor cells (1-7.8%). ALDHhigh cells formed tumors from as few as 500 cells in 24/45 implantations while only 3/37 implantations of ALDHlow cells formed tumors. Conclusions ALDHhigh cells comprise a subpopulation cells in HNSCC that are tumorigenic and capable of producing tumors at very low numbers. This finding indicates that ALDH activity on its own is a highly selective marker for CSCs in HNSCC. PMID:20073073

Core-6 fucose and the oligomerization of the 1918 pandemic influenza viral neuraminidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Zhengliang L., E-mail: Leon.wu@bio-techne.com; Zhou, Hui; Ethen, Cheryl M.

The 1918 H1N1 influenza virus was responsible for one of the most deadly pandemics in human history. Yet to date, the structure component responsible for its virulence is still a mystery. In order to search for such a component, the neuraminidase (NA) antigen of the virus was expressed, which led to the discovery of an active form (tetramer) and an inactive form (dimer and monomer) of the protein due to different glycosylation. In this report, the N-glycans from both forms were released and characterized by mass spectrometry. It was found that the glycans from the active form had 26% core-6more » fucosylated, while the glycans from the inactive form had 82% core-6 fucosylated. Even more surprisingly, the stalk region of the active form was almost completely devoid of core-6-linked fucose. These findings were further supported by the results obtained from in vitro incorporation of azido fucose and {sup 3}H-labeled fucose using core-6 fucosyltransferase, FUT8. In addition, the incorporation of fucose did not change the enzymatic activity of the active form, implying that core-6 fucose is not directly involved in the enzymatic activity. It is postulated that core-6 fucose prohibits the oligomerization and subsequent activation of the enzyme. - Graphical abstract: Proposed mechanism for how core-fucose prohibits the tetramerization of the 1918 pandemic viral neuraminidase. Only the cross section of the stalk region with two N-linked glycans are depicted for clarity. (A) Carbohydrate–carbohydrate interaction on non-fucosylated monomer allows tetramerization. (B) Core-fucosylation disrupts the interaction and prevents the tetramerization. - Highlights: • Expressed 1918 pandemic influenza viral neuraminidase has inactive and active forms. • The inactive form contains high level of core-6 fucose, while the active form lacks such modification. • Core fucose could interfere the oligomerization of the neuraminidase and thus its activation. • This discovery may explain why 1918 pandemic influenza caused higher death rate among young population.« less

Stability of human interferon-beta 1: oligomeric human interferon-beta 1 is inactive but is reactivated by monomerization.

PubMed

Utsumi, J; Yamazaki, S; Kawaguchi, K; Kimura, S; Shimizu, H

1989-10-05

Human interferon-beta 1 is extremely stable is a low ionic strength solution of pH 2 such as 10 mM HCl at 37 degrees C. However, the presence of 0.15 M NaCl led to a remarkable loss of antiviral activity. The molecular-sieve high-performance liquid chromatography revealed that, whereas completely active human interferon-beta 1 eluted as a 25 kDa species (monomeric form), the inactivated preparation eluted primarily as a 90 kDa species (oligomeric form). The specific activity (units per mg protein) of the oligomeric form was approx. 10% of that of the monomeric form. This observation shows that oligomeric human interferon-beta 1 is apparently in an inactive form. When the oligomeric eluate was resolved by polyacrylamide gel containing sodium dodecyl sulphate (SDS), it appeared to be monomeric under non-reducing conditions. Monomerization of the oligomeric human interferon-beta 1 by treatment with 1% SDS, fully regenerated its antiviral activity. These results suggest that the inactivation of the human interferon-beta 1 preparation was caused by its oligomerization via hydrophobic interactions without the formation of intermolecular disulphide bonds. These oligomers can be dissociated by SDS to restore biological activity.

Method of making a high performance ultracapacitor

DOEpatents

Farahmandi, C. Joseph; Dispennette, John M.

2000-07-26

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Highly active self-immobilized FI-Zr catalysts in a PCP framework for ethylene polymerization.

PubMed

Li, He; Xu, Bo; He, Jianghao; Liu, Xiaoming; Gao, Wei; Mu, Ying

2015-12-04

A series of zirconium-based porous coordination polymers (PCPs) containing FI catalysts in the frameworks have been developed and studied as catalysts for ethylene polymerization. These PCPs exhibit good catalytic activities and long life times, producing polyethylenes with high molecular weights and bimodal molecular weight distribution in the form of particles.

Methods of selectively incorporating metals onto substrates

DOEpatents

Ernst; Richard D. , Eyring; Edward M. , Turpin; Gregory C. , Dunn; Brian C.

2008-09-30

A method for forming multi-metallic sites on a substrate is disclosed and described. A substrate including active groups such as hydroxyl can be reacted with a pretarget metal complex. The target metal attached to the active group can then be reacted with a secondary metal complex such that an oxidation-reduction (redox) reaction occurs to form a multi-metallic species. The substrate can be a highly porous material such as aerogels, xerogels, zeolites, and similar materials. Additional metal complexes can be reacted to increase catalyst loading or control co-catalyst content. The resulting compounds can be oxidized to form oxides or reduced to form metals in the ground state which are suitable for practical use.

Members of the DAN family are BMP antagonists that form highly stable noncovalent dimers.

PubMed

Kattamuri, Chandramohan; Luedeke, David M; Nolan, Kristof; Rankin, Scott A; Greis, Kenneth D; Zorn, Aaron M; Thompson, Thomas B

2012-12-14

Signaling of bone morphogenetic protein (BMP) ligands is antagonized by a number of extracellular proteins, including noggin, follistatin and members of the DAN (differential screening selected gene abberative in neuroblastoma) family. Structural studies on the DAN family member sclerostin (a weak BMP antagonist) have previously revealed that the protein is monomeric and consists of an eight-membered cystine knot motif with a fold similar to transforming growth factor-β ligands. In contrast to sclerostin, certain DAN family antagonists, including protein related to DAN and cerberus (PRDC), have an unpaired cysteine that is thought to function in covalent dimer assembly (analogous to transforming growth factor-β ligands). Through a combination of biophysical and biochemical studies, we determined that PRDC forms biologically active dimers that potently inhibit BMP ligands. Furthermore, we showed that PRDC dimers, surprisingly, are not covalently linked, as mutation of the unpaired cysteine does not inhibit dimer formation or biological activity. We further demonstrated that the noncovalent PRDC dimers are highly stable under both denaturing and reducing conditions. This study was extended to the founding family member DAN, which also forms noncovalent dimers that are highly stable. These results demonstrate that certain DAN family members can form both monomers and noncovalent dimers, implying that biological activity of DAN family members might be linked to their oligomeric state. Published by Elsevier Ltd.

Comprehensive Structural Characterization of the Bacterial Homospermidine Synthase–an Essential Enzyme of the Polyamine Metabolism

PubMed Central

Krossa, Sebastian; Faust, Annette; Ober, Dietrich; Scheidig, Axel J.

2016-01-01

The highly conserved bacterial homospermidine synthase (HSS) is a key enzyme of the polyamine metabolism of many proteobacteria including pathogenic strains such as Legionella pneumophila and Pseudomonas aeruginosa; The unique usage of NAD(H) as a prosthetic group is a common feature of bacterial HSS, eukaryotic HSS and deoxyhypusine synthase (DHS). The structure of the bacterial enzyme does not possess a lysine residue in the active center and thus does not form an enzyme-substrate Schiff base intermediate as observed for the DHS. In contrast to the DHS the active site is not formed by the interface of two subunits but resides within one subunit of the bacterial HSS. Crystal structures of Blastochloris viridis HSS (BvHSS) reveal two distinct substrate binding sites, one of which is highly specific for putrescine. BvHSS features a side pocket in the direct vicinity of the active site formed by conserved amino acids and a potential substrate discrimination, guiding, and sensing mechanism. The proposed reaction steps for the catalysis of BvHSS emphasize cation-π interaction through a conserved Trp residue as a key stabilizer of high energetic transition states. PMID:26776105

Powder-in-tube and thick-film methods of fabricating high temperature superconductors having enhanced biaxial texture

DOEpatents

Goyal, Amit; Kroeger, Donald M.

2003-11-11

A method for forming an electronically active biaxially textured article includes the steps of providing a substrate having a single crystal metal or metal alloy surface, deforming the substrate to form an elongated substrate surface having biaxial texture and depositing an epitaxial electronically active layer on the biaxially textured surface. The method can include at least one annealing step after the deforming step to produce the biaxially textured substrate surface. The invention can be used to form improved biaxially textured articles, such as superconducting wire and tape articles having improved J.sub.c values.

New and highly sensitive assay for L-5-hydroxytryptophan decarboxylase activity by high-performance liquid chromatography-voltammetry.

PubMed

Rahman, M K; Nagatsu, T; Kato, T

1980-12-12

This paper describes a new, inexpensive and highly sensitive assay for aromatic L-amino acid decarboxylase (AADC) activity, using L-5-hydroxytryptophan (L-5-HTP) as substrate, in rat and human brains and serum by high-performance liquid chromatography (HPLC) with voltammetric detection. L-5-HTP was used as substrate and D-5-HTP for the blank. After isolating serotonin (5-HT) formed enzymatically from L-5-HTP on a small Amberlite CG-50 column, the 5-HT was eluted with hydrochloric acid and assayed by HPLC with a voltammetric detector. N-Methyldopamine was added to each incubation mixture as an internal standard. This method is sensitive enough to measure 5-HT, formed by the enzyme, 100 fmol to 140 pmol or more. An advantage of this method is that one can incubate the enzyme for longer time (up to 150 min), as compared with AADC assay using L-DOPA as substrate, resulting in a very high sensitivity. By using this new method, AADC activity was discovered in rat serum.

Special Form Testing of Sealed Source Encapsulation for High-Alpha-Activity Actinide Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Oscar A

In the United States all transportation of radioactive material is regulated by the U.S. Department of Transportation (DOT). Beginning in 2008 a new type of sealed-source encapsulation package was developed and tested by Oak Ridge National Laboratory (ORNL). These packages contain high-alpha-activity actinides and are regulated and transported in accordance with the requirements for DOT Class 7 hazardous material. The DOT provides specific regulations pertaining to special form encapsulation designs. The special form designation indicates that the encapsulated radioactive contents have a very low probability of dispersion even when subjected to significant structural events. The special form designs have beenmore » shown to simplify the delivery, transport, acceptance, and receipt processes. It is intended for these sealed-source encapsulations to be shipped to various facilities making it very advantageous for them to be certified as special form. To this end, DOT Certificates of Competent Authority (CoCAs) have been sought for the design suitable for containing high-alpha-activity actinide materials. This design consists of the high-alpha-activity material encapsulated within a triangular zirconia canister, referred to as a ZipCan, tile that is then enclosed by a spherical shell. The spherical shell design, with ZipCan tile inside, was tested for compliance with the special form regulations found in 49 CFR 173.469. The spherical enclosure was subjected to 9-m impact, 1 m percussion, and 10-minute thermal tests at the Packaging Evaluation Facility located at the National Transportation Research Center in Knoxville, TN USA and operated by ORNL. Before and after each test, the test units were subjected to a helium leak check and a bubble test. The ZipCan tiles and core were also subjected to the tests required for ISO 2919:2012(E), including a Class IV impact test and heat test and subsequently subjected to helium leakage rate tests [49 CFR 173.469(a)(4)(i)]. The impact-tile test unit contained a nonradioactive surrogate; however, the thermal test unit contained a radioactive source. This paper describes the regulatory special form tests and presents detailed impact and leak test results that demonstrate that the sealed source encapsulation designs satisfy the regulatory tests.« less

N-Heterocyclic Olefins as Robust Organocatalyst for the Chemical Conversion of Carbon Dioxide to Value-Added Chemicals.

PubMed

Saptal, Vitthal B; Bhanage, Bhalchandra M

2016-08-09

In this report, the activity of N-heterocyclic olefins (NHOs) as a newly emerging class of organocatalyst is investigated for the chemical fixation of carbon dioxide through reactions with aziridines to form oxazolidinones and the N-formylation of amines with polymethylhydrosiloxane (PMHS) or 9-borabicyclo[3.3.1]nonane (9-BBN) as the reducing agent under mild conditions. The exocyclic carbon atoms of NHOs are highly nucleophilic owing to the electron-donating ability of the two nitrogen atoms. This high nucleophilicity of the NHOs activates CO2 molecules to form zwitterionic NHO-carboxylate (NHO-CO2 ) adducts, which are active in formylation reactions as well as the carboxylation of aziridines to oxazolidinones. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

STD Symptoms: Common STDs and Their Symptoms

MedlinePlus

... groin. In some cases, the infection can be active and contagious even when sores aren't present. HPV infection is one of the most common types of STIs. Some forms put women at high risk of cervical cancer. Other forms cause genital warts. HPV usually has ...

Positive correlation between blood pressure or heart rate and chymase-dependent angiotensin II-forming activity in circulating mononuclear leukocytes measured by new ELISA.

PubMed

Okamura, Keisuke; Okuda, Tetsu; Shirai, Kazuyuki; Urata, Hidenori

2018-01-01

The aim of the present study was to establish a convenient clinically applicable assay method for chymase-dependent angiotensin II forming activity of circulating mononuclear leukocytes (CML), which was potentially a marker of tissue chymase activity. Using this method, association between CML chymase activity and clinical parameters was determined. Cardiovascular outpatients (n = 170) without taking antihypertensive medication were recruited. An ELISA for chymase-dependent angiotensin II-forming activity in CML was established using Nma /Dnp-modified angiotensin I. Logistic regression analysis revealed that age and male gender were significant independent determinants of the increased CML chymase activity. After adjustment by age and gender, the CML chymase activity was positively correlated with systolic blood pressure, pulse rate, and the brain natriuretic peptide level. The relation between blood pressure and CML chymase activity suggests that it might reflect that increased tissue chymase activity contributes to systemic high blood pressure and heart rate because plasma chymase is inactive due to inhibitory plasma inhibitors.

Stability hierarchy between Piracetam forms I, II, and III from experimental pressure-temperature diagrams and topological inferences.

PubMed

Toscani, Siro; Céolin, René; Minassian, Léon Ter; Barrio, Maria; Veglio, Nestor; Tamarit, Josep-Lluis; Louër, Daniel; Rietveld, Ivo B

2016-01-30

The trimorphism of the active pharmaceutical ingredient piracetam is a famous case of polymorphism that has been frequently revisited by many researchers. The phase relationships between forms I, II, and III were ambiguous because they seemed to depend on the heating rate of the DSC and on the history of the samples or they have not been observed at all (equilibrium II-III). In the present paper, piezo-thermal analysis and high-pressure differential thermal analysis have been used to elucidate the positions of the different solid-solid and solid-liquid equilibria. The phase diagram, involving the three solid phases, the liquid phase and the vapor phase, has been constructed. It has been shown that form III is the high-pressure, low-temperature form and the stable form at room temperature. Form II is stable under intermediary conditions and form I is the low pressure, high temperature form, which possesses a stable melting point. The present paper demonstrates the strength of the topological approach based on the Clapeyron equation and the alternation rule when combined with high-pressure measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

Cellular distribution, purification and electrophoretic properties of malate dehydrogenase in Trichuris ovis and inhibition by benzimidazoles and pyrimidine derivatives.

PubMed

Sanchez-Moreno, M; Ortega, J E; Valero, A

1989-12-01

High levels of malate dehydrogenase were found in Trichuris ovis. Two molecular forms of the enzyme, of different cellular location and electrophoretic pattern, were isolated and purified. The activity of soluble malate dehydrogenase was greater than that of mitochondrial malate dehydrogenase. Both forms also displayed different electrophoretic profiles in comparison with purified extracts from goat (Capra hircus) liver. Substrate concentration directly affected enzyme activity. Host and parasite malate dehydrogenase activity were both inhibited by a series of benzimidazoles and pyrimidine-derived compounds, some of which markedly reduced parasite enzyme activity, but not host enzyme activity. Percentage inhibition by some pyrimidine derivatives was greater than that produced by benzimidazoles.

An ELISA method detecting the active form of suPAR.

PubMed

Zhou, Xiaolei; Xu, Mingming; Huang, Hailong; Mazar, Andrew; Iqbal, Zafar; Yuan, Cai; Huang, Mingdong

2016-11-01

Urokinase plasminogen activator receptor (uPAR) exists in a number of formats in human plasma, including soluble uPAR (suPAR) and uPAR fragments. We developed an ELISA method to detect specifically the active form suPAR, which binds to its natural ligand uPA. The intra CV and inter CV of this ELISA assay is 8.5% and 9.6% respectively, and the assay can recover 99.74% of added recombinant suPAR from 10% plasma. This assay is quite sensitive, capable of detecting down to 15pg/ml of suPAR, and can measure suPAR concentrations in the range of 0.031-8ng/ml with high linear relationship. Plasma samples from pregnant women were also measured for the active form of suPAR with this assay, giving an averaged level of 1.39ng/ml, slightly higher than the level of pooled plasma from healthy donors (0.96ng/ml). This study demonstrates the feasibility to measure the active form of suPAR, which will likely have value in clinical applications. Copyright © 2016. Published by Elsevier B.V.

Structure of the unliganded form of the proprotein convertase furin suggests activation by a substrate-induced mechanism

PubMed Central

Dahms, Sven O.; Arciniega, Marcelino; Steinmetzer, Torsten; Huber, Robert; Than, Manuel E.

2016-01-01

Proprotein convertases (PCs) are highly specific proteases required for the proteolytic modification of many secreted proteins. An unbalanced activity of these enzymes is connected to pathologies like cancer, atherosclerosis, hypercholesterolaemia, and infectious diseases. Novel protein crystallographic structures of the prototypical PC family member furin in different functional states were determined to 1.8–2.0 Å. These, together with biochemical data and modeling by molecular dynamics calculations, suggest essential elements underlying its unusually high substrate specificity. Furin shows a complex activation mechanism and exists in at least four defined states: (i) the “off state,” incompatible with substrate binding as seen in the unliganded enzyme; (ii) the active “on state” seen in inhibitor-bound furin; and the respective (iii) calcium-free and (iv) calcium-bound forms. The transition from the off to the on state is triggered by ligand binding at subsites S1 to S4 and appears to underlie the preferential recognition of the four-residue sequence motif of furin. The molecular dynamics simulations of the four structural states reflect the experimental observations in general and provide approximations of the respective stabilities. Ligation by calcium at the PC-specific binding site II influences the active-site geometry and determines the rotamer state of the oxyanion hole-forming Asn295, and thus adds a second level of the activity modulation of furin. The described crystal forms and the observations of different defined functional states may foster the development of new tools and strategies for pharmacological intervention targeting furin. PMID:27647913

Role of C-terminal heptapeptide in pore-forming activity of antimicrobial agent, gaegurin 4.

PubMed

Kim, H J; Kim, S S; Lee, M H; Lee, B J; Ryu, P D

2004-10-01

Gaegurin 4 (GGN4) is an antimicrobial peptide of 37 amino acids isolated from the skin of a frog, Rana rugosa. GGN4 has a disulfide bond between the residues 31 and 37, which is highly conserved among the antimicrobial peptides isolated from skin of the genus, Rana. However, the role of this C-terminal heptapeptide motif is not well understood. In this work, we compared the membrane effects of the full-length GGN4 (C37) and GGN4 1-30 (C30), which is devoid of the C-terminal seven amino acids to elucidate the function of the C-terminal motif. C37 induced significantly larger membrane conductance (>10x) in the model lipid bilayers formed with acidic and neutral phospholipids and larger K+ efflux from gram-positive (>30x) and gram-negative bacteria. However, the pores induced by C37 and C30 were not different in their permeability to K+ over Cl- (permeability ratio of K+ to Cl- = 4.8-7.1). In addition, the pore-forming effect of C37 or C30 in acidic membranes was not different from that in neutral membranes. Furthermore, C37-induced K+ efflux was not significantly decreased by the reducing agent, dithiothreitol. The results indicate that C-terminal heptapeptide sequence plays an important role in maintaining the high pore-forming activity of GGN4, but does not participate in forming GGN4-induced pore structure. The disulfide bond in this region does not appear critical for such high ionophoric activity of GGN4.

Energy and Man's Environment Activity Guide: An Interdisciplinary Teacher's Guide to Energy and Environmental Activities, Section One - Sources of Energy.

ERIC Educational Resources Information Center

Jones, John, Ed.

This publication presents the activities pertaining to the first goal of this activity guide series. The activities in this publication focus primarily on the availability of resources, forms of energy, natural laws, and socioeconomic considerations. These materials are appropriate for middle school and junior high school students. These…

Cultured Neuronal Networks Express Complex Patterns of Activity and Morphological Memory

NASA Astrophysics Data System (ADS)

Raichman, Nadav; Rubinsky, Liel; Shein, Mark; Baruchi, Itay; Volman, Vladislav; Ben-Jacob, Eshel

The following sections are included: * Cultured Neuronal Networks * Recording the Network Activity * Network Engineering * The Formation of Synchronized Bursting Events * The Characterization of the SBEs * Highly-Active Neurons * Function-Form Relations in Cultured Networks * Analyzing the SBEs Motifs * Network Repertoire * Network under Hypothermia * Summary * Acknowledgments * References

Electrospun polylactic acid and polyvinyl alcohol fibers as efficient and stable nanomaterials for immobilization of lipases.

PubMed

Sóti, Péter Lajos; Weiser, Diana; Vigh, Tamás; Nagy, Zsombor Kristóf; Poppe, László; Marosi, György

2016-03-01

Electrospinning was applied to create easy-to-handle and high-surface-area membranes from continuous nanofibers of polyvinyl alcohol (PVA) or polylactic acid (PLA). Lipase PS from Burkholderia cepacia and Lipase B from Candida antarctica (CaLB) could be immobilized effectively by adsorption onto the fibrous material as well as by entrapment within the electrospun nanofibers. The biocatalytic performance of the resulting membrane biocatalysts was evaluated in the kinetic resolution of racemic 1-phenylethanol (rac-1) and 1-phenylethyl acetate (rac-2). Fine dispersion of the enzymes in the polymer matrix and large surface area of the nanofibers resulted in an enormous increase in the activity of the membrane biocatalyst compared to the non-immobilized crude powder forms of the lipases. PLA as fiber-forming polymer for lipase immobilization performed better than PVA in all aspects. Recycling studies with the various forms of electrospun membrane biocatalysts in ten cycles of the acylation and hydrolysis reactions indicated excellent stability of this forms of immobilized lipases. PLA-entrapped lipases could preserve lipase activity and enantiomer selectivity much better than the PVA-entrapped forms. The electrospun membrane forms of CaLB showed high mechanical stability in the repeated acylations and hydrolyses than commercial forms of CaLB immobilized on polyacrylamide beads (Novozyme 435 and IMMCALB-T2-150).

Erythroid colony induction without erythropoietin by Friend leukemia virus in vitro.

PubMed

Clarke, B J; Axelrad, A A; Shreeve, M M; McLeod, D L

1975-09-01

Erythroid colonies could be produced without the addition of erythropeietin in plasma cultures seeded with bone marrow cells from normal C3Hf/Bi mice by exposure of the cells in vitro to medium from a cell line (IS) that continuously produces Friend leukemia virus in culture. The activity in the culture medium was viral rather than erythropoietin-like, since it was sedimentable by high-speed centrifugation and heat labile. Erythroid colonies did not develop when the bone marrow cells exposed to virus-containing medium were from mice genetically resistant to Friend virus. IS culture medium contained both Friend spleen focus-forming and XC-plaque-forming activities. No erythroid colonies were induced when genetically sensitive cells were exposed to a preparation from which the spleen focus-forming activity had been removed, but which contained XC plaque-forming activity in high concentration. Thus the spleen focus-forming component of Friend virus appeared to be responsible for inducing erythroid colony formation without erythropoietin in vitro. Some erythroid colonies were also found in control cultures to which neither virus nor erythropoietin had been added. Reduction in the concentration of fetal calf serum in the culture medium substantially decreased the number of these colonies but had only a minor effect on the number of virus-induced colonies. The number of erythroid colonies produced after 2 days of culture without erythropoietin or fetal calf serum was approximately proportional to the titer of Friend spleen focus-forming virus to whcih the bone marrow cells had been exposed. This system should prove useful for investigation in vitro of Friend virus--host cell interactions which lead to erythropoietin-independent erythropoiesis.

Downregulation of monocytic differentiation via modulation of CD147 by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors.

PubMed

Sasidhar, Manda V; Chevooru, Sai Krishnaveni; Eickelberg, Oliver; Hartung, Hans-Peter; Neuhaus, Oliver

2017-01-01

CD147 is an activation induced glycoprotein that promotes the secretion and activation of matrix metalloproteinases (MMPs) and is upregulated during the differentiation of macrophages. Interestingly, some of the molecular functions of CD147 rely on its glycosylation status: the highly glycosylated forms of CD147 induce MMPs whereas the lowly glycosylated forms inhibit MMP activation. Statins are hydroxy-methylglutaryl coenzyme A reductase inhibitors that block the synthesis of mevalonate, thereby inhibiting all mevalonate-dependent pathways, including isoprenylation, N-glycosylation and cholesterol synthesis. In this study, we investigated the role of statins in the inhibition of macrophage differentiation and the associated process of MMP secretion through modulation of CD147. We observed that differentiation of the human monocytic cell line THP-1 to a macrophage phenotype led to upregulation of CD147 and CD14 and that this effect was inhibited by statins. At the molecular level, statins altered CD147 expression, structure and function by inhibiting isoprenylation and N-glycosylation. In addition, statins induced a shift of CD147 from its highly glycosylated form to its lowly glycosylated form. This shift in N-glycosylation status was accompanied by a decrease in the production and functional activity of MMP-2 and MMP-9. In conclusion, these findings describe a novel molecular mechanism of immune regulation by statins, making them interesting candidates for autoimmune disease therapy.

Modulation of GSH with exogenous agents leads to changes in glyoxalase 1 enzyme activity in VL-17A cells exposed to chronic alcohol plus high glucose.

PubMed

Kumar, S Mathan; Swaminathan, Kavitha; Clemens, Dahn L; Dey, Aparajita

2014-02-01

Gluthathione (GSH) is a major cellular antioxidant. The present study utilizing VL-17A cells exposed to chronic alcohol plus high glucose investigated the changes in oxidative stress, toxicity, and glyoxalase 1 activity as a detoxification pathway due to changes in GSH level through GSH supplementation with N-acetyl cysteine (NAC) or ursodeoxycholic acid (UDCA) and its depletion through buthionine sulfoximine (BSO) or diethyl maleate (DEM). Glyoxalase 1 plays an important role in detoxification of methylglyoxal which is formed as a precursor of advanced glycated end products formed due to high glucose mediated oxidative stress. Significant changes in glyoxalase 1 activity utilizing methylglyoxal or glyoxal as substrates occurred with NAC or UDCA or BSO or DEM supplementation in chronic alcohol plus high glucose treated VL-17A cells. NAC or UDCA administration in chronic alcohol plus high glucose treated VL-17A cells increased viability and decreased ROS levels, lipid peroxidation and 3-nitrotyrosine adduct formation. Similarly, GSH depletion with BSO or DEM had an opposite effect on the parameters in chronic alcohol plus high glucose treated VL-17A cells. In conclusion, modulation of GSH with NAC or UDCA or BSO or DEM leads to significant changes in oxidative stress, glyoxalase 1 enzyme activity and toxicity in chronic alcohol plus high glucose treated VL-17A cells.

V4 activity predicts the strength of visual short-term memory representations.

PubMed

Sligte, Ilja G; Scholte, H Steven; Lamme, Victor A F

2009-06-10

Recent studies have shown the existence of a form of visual memory that lies intermediate of iconic memory and visual short-term memory (VSTM), in terms of both capacity (up to 15 items) and the duration of the memory trace (up to 4 s). Because new visual objects readily overwrite this intermediate visual store, we believe that it reflects a weak form of VSTM with high capacity that exists alongside a strong but capacity-limited form of VSTM. In the present study, we isolated brain activity related to weak and strong VSTM representations using functional magnetic resonance imaging. We found that activity in visual cortical area V4 predicted the strength of VSTM representations; activity was low when there was no VSTM, medium when there was a weak VSTM representation regardless of whether this weak representation was available for report or not, and high when there was a strong VSTM representation. Altogether, this study suggests that the high capacity yet weak VSTM store is represented in visual parts of the brain. Allegedly, only some of these VSTM traces are amplified by parietal and frontal regions and as a consequence reside in traditional or strong VSTM. The additional weak VSTM representations remain available for conscious access and report when attention is redirected to them yet are overwritten as soon as new visual stimuli hit the eyes.

Aluminum-carbon composite electrode

DOEpatents

Farahmandi, C. Joseph; Dispennette, John M.

1998-07-07

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Aluminum-carbon composite electrode

DOEpatents

Farahmandi, C.J.; Dispennette, J.M.

1998-07-07

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg. 3 figs.

[Active forms of oxygen and nitrogen in blood cells of patients with rheumatoid arthritis: effect of laser therapy].

PubMed

Ostrakhovich, E A; Ilich-Stoianovich, O; Afanas'ev, I B

2001-01-01

Infrared pulse laser therapy was studied for its impact on the production of active forms of oxygen and nitrogen by neutrophils from patients with rheumatoid arthritis (RA). The authors determined the non-activated and PMA-activated production of superoxide anion-radical, peroxynitrite, peripheral neurophilic NAD.PH-oxidase and superoxide dismutase activities, and the red blood cell concentrations of reduced glutathione. Before therapy, non-activation RA neurophilic production of superoxide was much higher than in donors. Laser therapy made this parameter normal. Similarly, neutrophilic peroxynitrite production (defined by dihydrorhodamine oxidation) in RA patients was 1.7 times higher than the normal values. IF-laser therapy decreased peroxynitrite production to the values observed in donors. It is important that the therapy caused increased SOD activity (that was lower in RA patients prior to therapy) up to apparently control values. Thus, IF-laser therapy has a certain antioxidative effect by increasing SOD activity in RA patients' blood cells and reducing the production of highly reactive oxygen and nitrogen forms.

A pore-forming protein implements VLR-activated complement cytotoxicity in lamprey.

PubMed

Wu, Fenfang; Feng, Bo; Ren, Yong; Wu, Di; Chen, Yue; Huang, Shengfeng; Chen, Shangwu; Xu, Anlong

2017-01-01

Lamprey is a basal vertebrate with a unique adaptive immune system, which uses variable lymphocyte receptors (VLRs) for antigen recognition. Our previous study has shown that lamprey possessed a distinctive complement pathway activated by VLR. In this study, we identified a natterin family member-lamprey pore-forming protein (LPFP) with a jacalin-like lectin domain and an aerolysin-like pore-forming domain. LPFP had a high affinity with mannan and could form oligomer in the presence of mannan. LPFP could deposit on the surface of target cells, form pore-like complex resembling a wheel with hub and spokes, and mediate powerful cytotoxicity on target cells. These pore-forming proteins along with VLRs and complement molecules were essential for the specific cytotoxicity against exogenous pathogens and tumor cells. This unique cytotoxicity implemented by LPFP might emerge before or in parallel with the IgG-based classical complement lytic pathway completed by polyC9.

Homozygously deleted gene DACH1 regulates tumor-initiating activity of glioma cells

PubMed Central

Watanabe, Akira; Ogiwara, Hideki; Ehata, Shogo; Mukasa, Akitake; Ishikawa, Shumpei; Maeda, Daichi; Ueki, Keisuke; Ino, Yasushi; Todo, Tomoki; Yamada, Yasuhiro; Fukayama, Masashi; Saito, Nobuhito; Miyazono, Kohei; Aburatani, Hiroyuki

2011-01-01

Loss or reduction in function of tumor suppressor genes contributes to tumorigenesis. Here, by allelic DNA copy number analysis using single-nucleotide polymorphism genotyping array and mass spectrometry, we report homozygous deletion in glioblastoma multiformes at chromosome 13q21, where DACH1 gene is located. We found decreased cell proliferation of a series of glioma cell lines by forced expression of DACH1. We then generated U87TR-Da glioma cells, where DACH1 expression could be activated by exposure of the cells to doxycycline. Both ex vivo cellular proliferation and in vivo growth of s.c. transplanted tumors in mice are reduced in U87TR-Da cells with DACH1 expression (U87-DACH1-high), compared with DACH1-nonexpressing U87TR-Da cells (U87-DACH1-low). U87-DACH1-low cells form spheroids with CD133 and Nestin expression in serum-free medium but U87-DACH1-high cells do not. Compared with spheroid-forming U87-DACH1-low cells, adherent U87-DACH1-high cells display lower tumorigenicity, indicating DACH1 decreases the number of tumor-initiating cells. Gene expression analysis and chromatin immunoprecipitation assay reveal that fibroblast growth factor 2 (FGF2/bFGF) is transcriptionally repressed by DACH1, especially in cells cultured in serum-free medium. Exogenous bFGF rescues spheroid-forming activity and tumorigenicity of the U87-DACH1-high cells, suggesting that loss of DACH1 increases the number of tumor-initiating cells through transcriptional activation of bFGF. These results illustrate that DACH1 is a distinctive tumor suppressor, which does not only suppress growth of tumor cells but also regulates bFGF-mediated tumor-initiating activity of glioma cells. PMID:21750150

One-step purification of a functional, constitutively activated form of visual arrestin.

PubMed

Huang, Li; Mao, Xiang; Abdulaev, Najmoutin G; Ngo, Tony; Liu, Wei; Ridge, Kevin D

2012-03-01

Desensitization of agonist-activated G protein-coupled receptors (GPCRs) requires phosphorylation followed by the binding of arrestin, a ~48 kDa soluble protein. While crystal structures for the inactive, 'basal' state of various arrestins are available, the conformation of 'activated' arrestin adopted upon interaction with activated GPCRs remains unknown. As a first step towards applying high-resolution structural methods to study arrestin conformation and dynamics, we have utilized the subtilisin prodomain/Profinity eXact™ fusion-tag system for the high-level bacterial expression and one-step purification of wild-type visual arrestin (arrestin 1) as well as a mutant form (R175E) of the protein that binds to non-phosphorylated, light-activated rhodopsin (Rho∗). The results show that both prodomain/Profinity eXact™ fusion-tagged wild-type and R175E arrestins can be expressed to levels approaching 2-3 mg/l in Luria-Bertani media, and that the processed, tag-free mature forms can be purified to near homogeneity using a Bio-Scale™ Mini Profinity eXact™ cartridge on the Profinia™ purification system. Functional analysis of R175E arrestin generated using this approach shows that it binds to non-phosphorylated rhodopsin in a light-dependent manner. These findings should facilitate the structure determination of this 'constitutively activated' state of arrestin 1 as well as the monitoring of conformational changes upon interaction with Rho∗. Copyright © 2011 Elsevier Inc. All rights reserved.

Proteolysis of truncated hemolysin A yields a stable dimerization interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novak, Walter R. P.; Bhattacharyya, Basudeb; Grilley, Daniel P.

2017-02-21

Wild-type and variant forms of HpmA265 (truncated hemolysin A) fromProteus mirabilisreveal a right-handed, parallel β-helix capped and flanked by segments of antiparallel β-strands. The low-salt crystal structures form a dimeric structureviathe implementation of on-edge main-chain hydrogen bonds donated by residues 243–263 of adjacent monomers. Surprisingly, in the high-salt structures of two variants, Y134A and Q125A-Y134A, a new dimeric interface is formedviamain-chain hydrogen bonds donated by residues 203–215 of adjacent monomers, and a previously unobserved tetramer is formed. In addition, an eight-stranded antiparallel β-sheet is formed from the flap regions of crystallographically related monomers in the high-salt structures. This new interfacemore » is possible owing to additional proteolysis of these variants after Tyr240. The interface formed in the high-salt crystal forms of hemolysin A variants may mimic the on-edge β-strand positioning used in template-assisted hemolytic activity.« less

Complexing of Green Tea Catechins with Food Constituents and Degradation of the Complexes by Lactobacillus plantarum

PubMed Central

HAYASHI, Taeko; UEDA, Shuhei; TSURUTA, Hiroki; KUWAHARA, Hiroshige; OSAWA, Ro

2012-01-01

Complexing of green tea catechins with food constituents and their hydrolysis by tannase-producing Lactobacillus plantarum strains, were investigated. Our observations indicated that 1) epigallocatechin gallate (EGCg) and other catechin galloyl esters bound with food ingredients (i.e., proteins) to form a complex that is likely to be unabsorbable through the intestinal wall, whereas most catechins not esterified with gallic acid (GA) remain in free form, not complexing with food ingredients; 2) tannase activity of L. plantarum is strain dependent, possibly grouped into those with high tannase activity hydrolyzing EGCg to epigallocatechin and GA and those with the low activity; and 3) L. plantarum strains with high tannase activity are capable of hydrolyzing not only intact EGCg but also EGCg and other catechin galloyl esters complexed with dietary proteins to free non-galloyl ester catechins and GA. The evidence suggests that L. plantarum with high tannase activity, if it colonizes the human intestine, would release free non-galloyl-ester catechins and GA that are readily absorbed through the human intestinal epithelia from the complexes, thereby ensuring maximum delivery of the bioactive polyphenols of green tea to the host. PMID:24936346

Structures and fabrication techniques for solid state electrochemical devices

DOEpatents

Visco, Steven J.; Jacobson, Craig P.; DeJonghe, Lutgard C.

2012-10-09

Porous substrates and associated structures for solid-state electrochemical devices, such as solid-oxide fuel cells (SOFCs), are low-cost, mechanically strong and highly electronically conductive. Some preferred structures have a thin layer of an electrocatalytically active material (e.g., Ni--YSZ) coating a porous high-strength alloy support (e.g., SS-430) to form a porous SOFC fuel electrode. Electrode/electrolyte structures can be formed by co-firing or constrained sintering processes.

Structures and fabrication techniques for solid state electrochemical devices

DOEpatents

Visco, Steven J.; Jacobson, Craig P.; DeJonghe, Lutgard C.

2008-04-01

Porous substrates and associated structures for solid-state electrochemical devices, such as solid-oxide fuel cells (SOFCs), are low-cost, mechanically strong and highly electronically conductive. Some preferred structures have a thin layer of an electrocatalytically active material (e.g., Ni--YSZ) coating a porous high-strength alloy support (e.g., SS-430) to form a porous SOFC fuel electrode. Electrode/electrolyte structures can be formed by co-firing or constrained sintering processes.

Monoclonal Antibody Testing for Cancer Metastasis

NASA Technical Reports Server (NTRS)

1993-01-01

Malignant cells are characterized by the ability to invade surrounding normal tissues. Tumor invasion is abetted by proteolytic enzymes that have been correlated with recurrent disease and metastasis. These enzymes are involved in a cascade of proteolytic interactions with other enzymes and inhibitors which allow cancer cells to dissolve surrounding extracellular matrix, thereby enabling the cells to rapidly invade adjacent tissues and migrate to metastatic sites distant from the primary tumor. Among these proteases are the plasminogen activators (PA), collagenase IV, faminase, and in some cases cathepsin D, which together mediate key steps in the invasion process of metastasis. Cells which have the selective advantage for invasion and metastasis are those capable of regulating their proteolytic activity and proliferation. Cells in the process of invasion would be probably down-regulated for proliferation, but subsequent to attachment and adhesion at a distant site, would then be in a proliferative mode, up-regulating DNA replication. Urokinase (uPA) can be present in the tissues in several molecular forms. The inactive proenzyme is a single chain protein (scuPA) that is cleaved at Lys. 158 to form the double chain, high molecular weight active form (HMW-uPA) of 54 kD. A low molecular weight form (LMW-uPA) can also be produced by cleavage of the HMW-U PA at Lys. 135 - Lys. 136 giving a 35 kD active enzyme. Recently, it has been shown that the HMW active form of urokinase, bound to the tumor cell membrane, is responsible for the local lysis of the extracellular matrix, hence the tissue invasion mechanism for metastasis (Andreasen et al, 19861. Receptor- (membrane) bound uPA is twice as efficient (catalytically) as free fluid-phase uPA. Tho unbound uPA and the LMW form is not responsible for most of the local dissolution of extracellular matrix in the immediate vicinity of the metastatic tumor cell. High levels of urokinase (greater than 3.49 ng/mg of total protein) extracted from breast tumor tissues have recently been shown, together with plasminogen activator inhibitor 1 (PAI-1), to be a good prognostic indicator for high risk of recurrence and shorter patient survival times. In this project, we have attempted to develop immunocytochemical methodologies for the clinical assessment of the expression of urokinase plasminogen activator, which has been implicated to be important for initial steps in tumor invasion, and to relate it to cell proliferation and DNA replication at the single-cell level.

A high-performance dual-scale porous electrode for vanadium redox flow batteries

NASA Astrophysics Data System (ADS)

Zhou, X. L.; Zeng, Y. K.; Zhu, X. B.; Wei, L.; Zhao, T. S.

2016-09-01

In this work, we present a simple and cost-effective method to form a dual-scale porous electrode by KOH activation of the fibers of carbon papers. The large pores (∼10 μm), formed between carbon fibers, serve as the macroscopic pathways for high electrolyte flow rates, while the small pores (∼5 nm), formed on carbon fiber surfaces, act as active sites for rapid electrochemical reactions. It is shown that the Brunauer-Emmett-Teller specific surface area of the carbon paper is increased by a factor of 16 while maintaining the same hydraulic permeability as that of the original carbon paper electrode. We then apply the dual-scale electrode to a vanadium redox flow battery (VRFB) and demonstrate an energy efficiency ranging from 82% to 88% at current densities of 200-400 mA cm-2, which is record breaking as the highest performance of VRFB in the open literature.

Reversible conformational transition gives rise to 'zig-zag' temperature dependence of the rate constant of irreversible thermoinactivation of enzymes.

PubMed

Levitsky VYu; Melik-Nubarov, N S; Siksnis, V A; Grinberg VYa; Burova, T V; Levashov, A V; Mozhaev, V V

1994-01-15

We have obtained unusual 'zig-zag' temperature dependencies of the rate constant of irreversible thermoinactivation (k(in)) of enzymes (alpha-chymotrypsin, covalently modified alpha-chymotrypsin, and ribonuclease) in a plot of log k(in) versus reciprocal temperature (Arrhenius plot). These dependencies are characterized by the presence of both ascending and descending linear portions which have positive and negative values of the effective activation energy (Ea), respectively. A kinetic scheme has been suggested that fits best for a description of these zig-zag dependencies. A key element of this scheme is the temperature-dependent reversible conformational transition of enzyme from the 'low-temperature' native state to a 'high-temperature' denatured form; the latter form is significantly more stable against irreversible thermoinactivation than the native enzyme. A possible explanation for a difference in thermal stabilities is that low-temperature and high-temperature forms are inactivated according to different mechanisms. Existence of the suggested conformational transition was proved by the methods of fluorescence spectroscopy and differential scanning calorimetry. The values of delta H and delta S for this transition, determined from calorimetric experiments, are highly positive; this fact underlies a conclusion that this heat-induced transition is caused by an unfolding of the protein molecule. Surprisingly, in the unfolded high-temperature conformation, alpha-chymotrypsin has a pronounced proteolytic activity, although this activity is much smaller than that of the native enzyme.

Corrosion resistant ceramic materials

DOEpatents

Kaun, Thomas D.

1995-01-01

Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Corrosion resistant ceramic materials

DOEpatents

Kaun, Thomas D.

1996-01-01

Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Corrosion resistant ceramic materials

DOEpatents

Kaun, T.D.

1996-07-23

Ceramic materials are disclosed which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200--550 C or organic salt (including SO{sub 2} and SO{sub 2}Cl{sub 2}) at temperatures of 25--200 C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components. 1 fig.

Efficient Photocatalytic H2 Evolution: Controlled Dewetting-Dealloying to Fabricate Site-Selective High-Activity Nanoporous Au Particles on Highly Ordered TiO2 Nanotube Arrays.

PubMed

Nguyen, Nhat Truong; Altomare, Marco; Yoo, JeongEun; Schmuki, Patrik

2015-05-27

Anodic self-organized TiO2 nanostumps are formed and exploited for self-ordering dewetting of Au-Ag sputtered films. This forms ordered particle configurations at the tube top (crown position) or bottom (ground position). By dealloying from a minimal amount of noble metal, porous Au nanoparticles are then formed, which, when in the crown position, allow for a drastically improved photocatalytic H2 production compared with nanoparticles produced by conventional dewetting processes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Endurance training in hypertension is effective. Which form of sports, frequency and intensity of training? When should adjuvant chemotherapy be considered?].

PubMed

Ketelhut, R G

1998-12-10

Physical activity in the form of endurance training is highly recommendable for hypertensives. Both suitable and unsuitable forms of sports are identified. From various points of view, two one-hour sessions per week would appear to be optimal. The intensity of the activity should be oriented to the heart rate, and, for safety's sake, prior ergometric evaluation should be carried out. As a rule of thumb, the heart rate should not exceed 70% of the maximum rate during exercise. If the blood pressure should nevertheless increase too much, appropriate pharmacological treatment is indicated.

Bacterial activity in sea ice and open water of the Weddell Sea, Antarctica: A microautoradiographic study.

PubMed

Grossmann, S

1994-07-01

Metabolic activity of bacteria was investigated in open water, newly forming sea ice, and successive stages of pack ice in the Weddell Sea. Microautoradiography, using [(3)H]leucine as substrate, was compared with incorporation rates of [(3)H]leucine into proteins. Relation of [(3)H]leucine incorporation to the biomass of active bacteria provides information about changes of specific metabolic activity of cells. During a phytoplankton bloom in an ice-free, stratified water column, total numbers of bacteria in the euphotic zone averaged 2.3 × 10(5) ml(-1), but only about 13% showed activity via leucine uptake. Growth rate of the active bacteria was estimated as 0.3-0.4 days(-1). Total cell concentration of bacteria in 400 m depth was 6.6 × 10(4) ml(-1). Nearly 50% of these cells were active, although biomass production and specific growth rate were only about one-tenth that of the surface populations. When sea ice was forming in high concentrations of phytoplankton, bacterial biomass in the newly formed ice was 49.1 ng C ml(-1), exceeding that in open water by about one order of magnitude. Attachment of large bacteria to algal cells seems to cause their enrichment in the new ice, since specific bacterial activity was reduced during ice formation, and enrichment of bacteria was not observed when ice formed at low algal concentration. During growth of pack ice, biomass of bacteria increased within the brine channel system. Specific activity was still reduced at these later stages of ice development, and percentages of active cells were as low as 3-5%. In old, thick pack ice, bacterial activity was high and about 30% of cells were active. However, biomass-specific activity of bacteria remained significantly lower than that in open water. It is concluded that bacterial assemblages different to those of open water developed within the ice and were dominated by bacteria with lower average metabolic activity than those of ice-free water.

Expression, purification and characterization of inactive and active forms of ERK2 from insect expression system.

PubMed

Yan, Kelly; Merritt, Hanne; Crawford, Kenneth; Pardee, Gwynn; Cheng, Jan Marie; Widger, Stephania; Hekmat-Nejad, Mohammad; Zaror, Isabel; Sim, Janet

2015-06-01

Extracellular signal-regulated kinase 2 (ERK2) is a serine/threonine protein kinase involved in many cellular programs, such as cell proliferation, differentiation, motility and programed cell-death. It is therefore considered an important target in the treatment of cancer. In an effort to support biochemical screening and small molecule drug discovery, we established a robust system to generate both inactive and active forms of ERK2 using insect expression system. We report here, for the first time, that inactive ERK2 can be expressed and purified with 100% homogeneity in the unphosphorylated form using insect system. This resulted in a significant 20-fold yield improvement compared to that previously reported using bacterial expression system. We also report a newly developed system to generate active ERK2 in insect cells through in vivo co-expression with a constitutively active MEK1 (S218D S222D). Isolated active ERK2 was confirmed to be doubly phosphorylated at the correct sites, T185 and Y187, in the activation loop of ERK2. Both ERK2 forms, inactive and active, were well characterized by biochemical activity assay for their kinase function. Inactive and active ERK2 were the two key reagents that enabled successful high through-put biochemical assay screen and structural drug discovery studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Composite ceria-coated aerogels and methods of making the same

DOEpatents

Eyring, Edward M; Ernst, Richard D; Turpin, Gregory C; Dunn, Brian C

2013-05-07

Ceria-coated aerogels can include an aerogel support material having a stabilized ceria coating thereon. The ceria coating can be formed by solution or vapor deposition of alcogels or aerogels. Additional catalytic metal species can also be incorporated into the coating to form multi-metallic compounds having improved catalytic activity. Further, the ceria coated aerogels retain high surface areas at elevated temperatures. Thus, improvements in catalytic activity and thermal stability can be achieved using these ceria-coated composite aerogels.

Spent fuel treatment and mineral waste form development at Argonne National Laboratory-West

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goff, K.M.; Benedict, R.W.; Bateman, K.

1996-07-01

At Argonne National Laboratory-West (ANL-West) there are several thousand kilograms of metallic spent nuclear fuel containing bond sodium. This fuel will be treated in the Fuel Conditioning Facility (FCF) at ANL-West to produce stable waste forms for storage and disposal. Both mineral and metal high-level waste forms will be produced. The mineral waste form will contain the active metal fission products and the transuranics. Cold small-scale waste form testing has been on-going at Argonne in Illinois. Large-scale testing is commencing at ANL-West.

The development and characterization of an ELISA specifically detecting the active form of cathepsin K.

PubMed

Sun, S; Karsdal, M A; Bay-Jensen, A C; Sørensen, M G; Zheng, Q; Dziegiel, M H; Maksymowych, W P; Henriksen, K

2013-10-01

Cathepsin K plays essential roles in bone resorption and is intensely investigated as a therapeutic target for the treatment of osteoporosis. Hence an assessment of the active form of cathepsin K may provide important biological information in metabolic bone diseases, such as osteoporosis or ankylosing spondylitis. Presently there are no robust assays for the assessment of active cathepsin K in serum, and therefore an ELISA specifically detecting the N-terminal of the active form of cathepsin K was developed. The assay was technically robust, with a lowest limit of detection (LOD) of 0.085 ng/mL. The average intra- and inter-assay CV% were 6.60% and 8.56% respectively. The dilution recovery and spike recovery tests in human serum were within 100±20% within the range of the assay. A comparison of latent and active cathepsin K confirmed specificity towards the active form. Quantification of the levels of active cathepsin K in supernatants of purified human osteoclasts compared to corresponding macrophages showed a 30-fold induction (p<0.001). In contrast, in serum samples from osteoporotic women on estrogen or bisphosphonate therapy and from ankylosing spondylitis patients no clinically relevant differences were observed. In summary, we have developed a robust and sensitive assay specifically detecting the active form of cathepsin K; however, while it monitors osteoclasts with high specificity in vitro, it appears that circulating levels of active cathepsin K do not reflect bone changes under these circumstances. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Structure-function of proteins interacting with the α1 pore-forming subunit of high-voltage-activated calcium channels

PubMed Central

Neely, Alan; Hidalgo, Patricia

2014-01-01

Openings of high-voltage-activated (HVA) calcium channels lead to a transient increase in calcium concentration that in turn activate a plethora of cellular functions, including muscle contraction, secretion and gene transcription. To coordinate all these responses calcium channels form supramolecular assemblies containing effectors and regulatory proteins that couple calcium influx to the downstream signal cascades and to feedback elements. According to the original biochemical characterization of skeletal muscle Dihydropyridine receptors, HVA calcium channels are multi-subunit protein complexes consisting of a pore-forming subunit (α1) associated with four additional polypeptide chains β, α2, δ, and γ, often referred to as accessory subunits. Twenty-five years after the first purification of a high-voltage calcium channel, the concept of a flexible stoichiometry to expand the repertoire of mechanisms that regulate calcium channel influx has emerged. Several other proteins have been identified that associate directly with the α1-subunit, including calmodulin and multiple members of the small and large GTPase family. Some of these proteins only interact with a subset of α1-subunits and during specific stages of biogenesis. More strikingly, most of the α1-subunit interacting proteins, such as the β-subunit and small GTPases, regulate both gating and trafficking through a variety of mechanisms. Modulation of channel activity covers almost all biophysical properties of the channel. Likewise, regulation of the number of channels in the plasma membrane is performed by altering the release of the α1-subunit from the endoplasmic reticulum, by reducing its degradation or enhancing its recycling back to the cell surface. In this review, we discuss the structural basis, interplay and functional role of selected proteins that interact with the central pore-forming subunit of HVA calcium channels. PMID:24917826

DoD Science and Engineering Apprenticeship Program for High School Students, 1995-󈨤 Activities

DTIC Science & Technology

1996-06-01

University of Florida Sports Medicine Honor Roll Weightlifting , Swimming NAME: RACE: SEX: HIGH SCHOOL: ANTICIPATED COLLEGE: ANTICIPATED MAJOR...program. Three of the students took a Psychology course, one took a Nutritional Science class, one a Math course and two of them took a Meteorology...Awards and Scholarships: Honor Roll 13. Activities/Hobbies: Weightlifting , Swimming (Suggested Form) INFORMATION FOR EACH APPRENTICE

Geothermic analysis of high temperature hydrothermal activities area in Western plateau of Sichuan province, China

NASA Astrophysics Data System (ADS)

Zhang, J.

2016-12-01

There is a high temperature hydrothermal activity area in the western plateau of Sichuan. More than 200 hot springs points have been found in the region, including 11 hot spring water temperature above local boiling point. Most of these distribute along Jinshajjiang fracture, Dege-Xiangcheng fracture, Ganzi-Litang fracture as well as Xianshuihe fracture, and form three high-temperature hydrothermal activity strips in the NW-SE direction. Using gravity, magnetic, seismic and helium isotope data, this paper analyzed the crust-mantle heat flow structure, crustal heat source distribution and water heating system. The results show that the geothermal activity mainly controlled by the "hot" crust. The ratio of crustal heat flow and surface heat flow is higher than 60%. In the high temperature hydrothermal activities area, there is lower S wave velocity zone with Vs<3.2 km/s in 15 30 km depth in middle and lower crust. Basing on the S wave velocity inversion temperature of crust-mantle, it has been found that there is a high temperature layer with 850 1000 ° in 20 40 km depth. It is the main heat source of high temperature hydrothermal activity area of western Sichuan. Our argument is that atmospheric precipitation, surface water infiltrated along the fault fracture into the crustal deep, heating by crustal hot source, and circulation to surface become high temperature hot water. Geothermal water mainly reserve in the Triassic strata of the containing water good carbonate rocks, and in the intrusive granite which is along the fault zone. The thermal energy of Surface heat thermal activities mainly comes from the high-temperature hot source which is located in the middle and lower crust. Being in the deep crustal fracture, the groundwater infiltrated to the deep crust and absorbed heat, then, quickly got back to the surface and formed high hot springs.

High School/Hartnell Coordinating Council 1985-86 Year-End Report.

ERIC Educational Resources Information Center

Orton, Marylin

In spring 1985, Hartnell College and 10 area public and private high schools in California formed the High School/Hartnell Coordinating Council (HSHCC) to facilitate communication and cooperation between the high schools and the college. During 1985-86, HSHCC undertook the following activities: (1) monthly meetings to address issues of concern to…

Method of construction of a multi-cell solar array

NASA Technical Reports Server (NTRS)

Routh, D. E.; Hollis, B. R., Jr.; Feltner, W. R. (Inventor)

1979-01-01

The method of constructing a high voltage, low power, multicell solar array is described. A solar cell base region is formed in a substrate such as but not limited to silicon or sapphire. A protective coating is applied on the base and a patterned etching of the coating and base forms discrete base regions. A semiconductive junction and upper active region are formed in each base region, and defined by photolithography. Thus, discrete cells which are interconnected by metallic electrodes are formed.

Treated carbon fibers with improved performance for electrochemical and chemical applications

DOEpatents

Chu, X.; Kinoshita, Kimio

1999-02-23

A treated mesophase carbon fiber is disclosed having a high density of exposed edges on the fiber surface, and a method is described for making such a treated fiber. A carbon electrode is also described which is constructed from such treated mesophase carbon fibers. The resulting electrode, formed from such treated flexible carbon fibers, is characterized by a high density of active sites formed from such exposed edges, low corrosion, and good mechanical strength, and may be fabricated into various shapes. The treated mesophase carbon fibers of the invention are formed by first loading the surface of the mesophase carbon fiber with catalytic metal particles to form catalytic etch sites on a hard carbon shell of the fiber. The carbon fiber is then subject to an etch step wherein portions of the hard carbon shell or skin are selectively removed adjacent the catalytic metal particles adhering to the carbon shell. This exposes the underlying radial edges of the graphite-like layers within the carbon shell of the mesophase carbon fiber, which exposed radial edges then act as active sites of a carbon electrode subsequently formed from the treated mesophase carbon fibers. 14 figs.

Treated carbon fibers with improved performance for electrochemical and chemical applications

DOEpatents

Chu, Xi; Kinoshita, Kimio

1999-01-01

A treated mesophase carbon fiber is disclosed having a high density of exposed edges on the fiber surface, and a method of making such a treated fiber. A carbon electrode is also described which is constructed from such treated mesophase carbon fibers. The resulting electrode, formed from such treated flexible carbon fibers, is characterized by a high density of active sites formed from such exposed edges, low corrosion, and good mechanical strength, and may be fabricated into various shapes. The treated mesophase carbon fibers of the invention are formed by first loading the surface of the mesophase carbon fiber with catalytic metal particles to form catalytic etch sites on a hard carbon shell of the fiber. The carbon fiber is then subject to an etch step wherein portions of the hard carbon shell or skin are selectively removed adjacent the catalytic metal particles adhering to the carbon shell. This exposes the underlying radial edges of the graphite-like layers within the carbon shell of the mesophase carbon fiber, which exposed radial edges then act as active sites of a carbon electrode subsequently formed from the treated mesophase carbon fibers.

Alteration of pyruvate metabolism in African trypanosomes during differentiation from bloodstream into insect forms.

PubMed

Barnard, J P; Pedersen, P L

1994-08-15

In the presence of glucose and ample oxygen, insect form African trypanosomes release pyruvate more than 100-fold more slowly than do bloodstream forms. This rate decrease could not be accounted for simply by an increased mitochondrial pyruvate oxidation rate as inhibiting mitochondrial respiration increases pyruvate efflux to rates only 2-3% of that observed for bloodstream form trypanosomes. Alternatively, decreased pyruvate efflux from insect form trypanosomes could not be accounted for by decreased pyruvate transporter activity, which, surprisingly, was nearly as high in insect form trypanosomes as reported by us earlier for bloodstream forms (J.P. Barnard, B. Reynafarje, and P.L. Pedersen (1993) J. Biol. Chem. 268, 3654-3661). Rather, the low pyruvate efflux rate appears to be due primarily to reduced levels of the enzyme pyruvate kinase, which, in contrast to conclusions of an earlier study, is readily detected in insect form trypanosomes in the absence of added activators at an activity level about 4% of that found in bloodstream forms. Insect form pyruvate kinase seems to be located in the cytosol and exhibits kinetic profiles and constants nearly identical to those reported by us earlier for the bloodstream form enzyme (J.P. Barnard, and P.L. Pedersen (1988) Mol. Biochem. Parasitol. 31, 141-148). It is suggested that the reduced levels of pyruvate kinase, and hence the reduced pyruvate efflux rates, in insect form trypanosomes result from down regulation of the gene encoding the cytosolic enzyme.

Lysenin Toxin Membrane Insertion Is pH-Dependent but Independent of Neighboring Lysenins.

PubMed

Munguira, Ignacio L B; Takahashi, Hirohide; Casuso, Ignacio; Scheuring, Simon

2017-11-07

Pore-forming toxins form a family of proteins that act as virulence factors of pathogenic bacteria, but similar proteins are found in all kingdoms of life, including the vertebrate immune system. They are secreted as soluble monomers that oligomerize on target membranes in the so-called prepore state; after activation, they insert into the membrane and adopt the pore state. Lysenin is a pore-forming toxin from the earthworm Eisenida foetida, of which both the soluble and membrane-inserted structures are solved. However, the activation and membrane-insertion mechanisms have remained elusive. Here, we used high-speed atomic force microscopy to directly visualize the membrane-insertion mechanism. Changing the environmental pH from pH 7.5 to below pH 6.0 favored membrane insertion. We detected a short α-helix in the soluble structure that comprised three glutamic acids (Glu92, Glu94, and Glu97) that we hypothesized may represent a pH-sensor (as in similar toxins, e.g., Listeriolysin). Mutant lysenin still can form pores, but mutating these glutamic acids to glutamines rendered the toxin pH-insensitive. On the other hand, toxins in the pore state did not favor insertion of neighboring prepores; indeed, pore insertion breaks the hexagonal ordered domains of prepores and separates from neighboring molecules in the membrane. pH-dependent activation of toxins may represent a common feature of pore-forming toxins. High-speed atomic force microscopy with single-molecule resolution at high temporal resolution and the possibility of exchanging buffers during the experiments presents itself as a unique tool for the study of toxin-state conversion. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The oligomerization state determines regulatory properties and inhibitor sensitivity of type 4 cAMP-specific phosphodiesterases.

PubMed

Richter, Wito; Conti, Marco

2004-07-16

PDE4 splice variants are classified into long and short forms depending on the presence or absence of two unique N-terminal domains termed upstream conserved regions 1 and 2 (UCR1 and -2). We have shown previously that the UCR module mediates dimerization of PDE4 long forms, whereas short forms, which lack UCR1, behave as monomers. In the present study, we demonstrate that dimerization is an essential structural element that determines the regulatory properties and inhibitor sensitivities of PDE4 enzymes. Comparing the properties of the dimeric wild type PDE4D3 with several monomeric mutant PDE4D3 constructs revealed that disruption of dimerization ablates the activation of PDE4 long forms by either protein kinase A phosphorylation or phosphatidic acid binding. Moreover, the analysis of heterodimers consisting of a catalytically active and a catalytically inactive PDE4D3 subunit indicates that protein kinase A phosphorylation of both subunits is essential to fully activate PDE4 enzymes. In addition to affecting enzyme regulation, disruption of dimerization reduces the sensitivity of the enzymes toward the prototypical PDE4 inhibitor rolipram. Parallel binding assays indicated that this shift in rolipram sensitivity is likely mediated by a decrease in the number of inhibitor binding sites in the high affinity rolipram binding state. Thus, although dimerization is not a requirement for high affinity rolipram binding, it functions to stabilize PDE4 long forms in their high affinity rolipram binding conformation. Taken together, our data indicate that dimerization defines the properties of PDE4 enzymes and suggest a common structural and functional organization for all PDEs.

Structural and Functional Insights into the Catalytic Inactivity of the Major Fraction of Buffalo Milk Xanthine Oxidoreductase

PubMed Central

Gadave, Kaustubh S.; Panda, Santanu; Singh, Surender; Kalra, Shalini; Malakar, Dhruba; Mohanty, Ashok K.; Kaushik, Jai K.

2014-01-01

Background Xanthine oxidoreductase (XOR) existing in two interconvertible forms, xanthine dehydrogenase (XDH) and xanthine oxidase (XO), catabolises xanthine to uric acid that is further broken down to antioxidative agent allantoin. XOR also produces free radicals serving as second messenger and microbicidal agent. Large variation in the XO activity has been observed among various species. Both hypo and hyper activity of XOR leads to pathophysiological conditions. Given the important nutritional role of buffalo milk in human health especially in south Asia, it is crucial to understand the functional properties of buffalo XOR and the underlying structural basis of variations in comparison to other species. Methods and Findings Buffalo XO activity of 0.75 U/mg was almost half of cattle XO activity. Enzymatic efficiency (k cat/K m) of 0.11 sec−1 µM−1 of buffalo XO was 8–10 times smaller than that of cattle XO. Buffalo XOR also showed lower antibacterial activity than cattle XOR. A CD value (Δε430 nm) of 46,000 M−1 cm−1 suggested occupancy of 77.4% at Fe/S I centre. Buffalo XOR contained 0.31 molybdenum atom/subunit of which 48% existed in active sulfo form. The active form of XO in buffalo was only 16% in comparison to ∼30% in cattle. Sequencing revealed 97.4% similarity between buffalo and cattle XOR. FAD domain was least conserved, while metal binding domains (Fe/S and Molybdenum) were highly conserved. Homology modelling of buffalo XOR showed several variations occurring in clusters, especially close to FAD binding pocket which could affect NAD+ entry in the FAD centre. The difference in XO activity seems to be originating from cofactor deficiency, especially molybdenum. Conclusion A major fraction of buffalo milk XOR exists in a catalytically inactive form due to high content of demolybdo and desulfo forms. Lower Fe/S content and structural factors might be contributing to lower enzymatic efficiency of buffalo XOR in a minor way. PMID:24498153

High-gamma activity in the human hippocampus and parahippocampus during inter-trial rest periods of a virtual navigation task.

PubMed

Pu, Yi; Cornwell, Brian R; Cheyne, Douglas; Johnson, Blake W

2018-05-19

In rodents, hippocampal cell assemblies formed during learning of a navigation task are observed to re-emerge during resting (offline) periods, accompanied by high-frequency oscillations (HFOs). This phenomenon is believed to reflect mechanisms for strengthening newly-formed memory traces. Using magnetoencephalography recordings and a beamforming source location algorithm (synthetic aperture magnetometry), we investigated high-gamma (80-140 Hz) oscillations in the hippocampal region in 18 human participants during inter-trial rest periods in a virtual navigation task. We found right hippocampal gamma oscillations mirrored the pattern of theta power in the same region during navigation, varying as a function of environmental novelty. Gamma power during inter-trial rest periods was positively correlated with theta power during navigation in the first task set when the environment was new and predicted greater performance improvement in the subsequent task set two where the environment became familiar. These findings provide evidence for human hippocampal reactivation accompanied by high-gamma activities immediately after learning and establish a link between hippocampal high-gamma activities and subsequent memory performance. Copyright © 2018 Elsevier Inc. All rights reserved.

Chandra and ALMA observations of the nuclear activity in two strongly lensed star-forming galaxies

NASA Astrophysics Data System (ADS)

Massardi, M.; Enia, A. F. M.; Negrello, M.; Mancuso, C.; Lapi, A.; Vignali, C.; Gilli, R.; Burkutean, S.; Danese, L.; Zotti, G. De

2018-02-01

Aim. According to coevolutionary scenarios, nuclear activity and star formation play relevant roles in the early stages of galaxy formation. We aim at identifying them in high-redshift galaxies by exploiting high-resolution and high-sensitivity X-ray and millimeter-wavelength data to confirm the presence or absence of star formation and nuclear activity and describe their relative roles in shaping the spectral energy distributions and in contributing to the energy budgets of the galaxies. Methods: We present the data, model, and analysis in the X-ray and millimeter (mm) bands for two strongly lensed galaxies, SDP.9 (HATLAS J090740.0-004200) and SDP.11 (HATLAS J091043.1-000322), which we selected in the Herschel-ATLAS catalogs for their excess emission in the mid-IR regime at redshift ≳1.5. This emission suggests nuclear activity in the early stages of galaxy formation. We observed both of them with Chandra ACIS-S in the X-ray regime and analyzed the high-resolution mm data that are available in the ALMA Science Archive for SDP.9. By combining the information available in mm, optical, and X-ray bands, we reconstructed the source morphology. Results: Both targets were detected in the X-ray, which strongly indicates highly obscured nuclear activity. ALMA observations for SDP.9 for the continuum and CO(6-5) spectral line with high resolution (0.02 arcsec corresponding to 65 pc at the distance of the galaxy) allowed us to estimate the lensed galaxy redshift to a better accuracy than pre-ALMA estimates (1.5753 ± 0.0003) and to model the emission of the optical, millimetric, and X-ray band for this galaxy. We demonstrate that the X-ray emission is generated in the nuclear environment, which strongly supports that this object has nuclear activity. On the basis of the X-ray data, we attempt an estimate of the black hole properties in these galaxies. Conclusions: By taking advantage of the lensing magnification, we identify weak nuclear activity associated with high-z galaxies with high star formation rates. This is useful to extend the investigation of the relationship between star formation and nuclear activity to two intrinsically less luminous high-z star-forming galaxies than was possible so far. Given our results for only two objects, they alone cannot constrain the evolutionary models, but provide us with interesting hints and set an observational path toward addressing the role of star formation and nuclear activity in forming galaxies. The reduced images and data cubes as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A53

The dynamic behavior of microbubbles during long ultrasound tone-burst excitation: mechanistic insights into ultrasound-microbubble mediated therapeutics using high-speed imaging and cavitation detection

PubMed Central

Pacella, John J.; Villanueva, Flordeliza S.

2015-01-01

Ultrasound (US)-microbubble (MB) mediated therapies have been shown to restore perfusion and enhance drug/gene delivery. Due to the presumption that MBs do not persist during long US exposure under high acoustic pressures, most schemes utilize short US pulses when a high US pressure is employed. However, we recently observed an enhanced thrombolytic effect using long US pulses at high acoustic pressures. Therefore we explored the fate of MBs during long tone-burst exposures (5 ms) at various acoustic pressures and MB concentrations via direct high-speed optical observation and passive cavitation detection. MBs first underwent stable or inertial cavitation depending on the acoustic pressure, and then formed gas-filled clusters that continued to oscillate, break up, and form new clusters. Cavitation detection confirmed continued, albeit diminishing acoustic activity throughout the 5-ms US excitation. These data suggest that persisting cavitation activity during long tone-bursts may confer additional therapeutic effects. PMID:26603628

Intracellular activation of digestive zymogens in rat pancreatic acini. Stimulation by high doses of cholecystokinin.

PubMed Central

Leach, S D; Modlin, I M; Scheele, G A; Gorelick, F S

1991-01-01

The mechanism by which digestive zymogens become activated during acute pancreatitis remains poorly understood. Given the ability for cholecystokinin (CCK) to induce pancreatitis in vivo, the effects of high dose CCK on preparations of isolated pancreatic acini were examined. Using an immunologic technique for the detection of zymogen activation, CCK was found to stimulate the conversion of procarboxypeptidase A1 to a 35-kD form having the same net charge and electrophoretic mobility as purified recombinant carboxypeptidase A1. This enhanced conversion was proportional to the dose of CCK (maximal at 100 nM), and time dependent. CCK also produced changes in the electrophoretic mobility of procarboxypeptidase B and chymotrypsinogen 2 immunoreactivity, consistent with activation of these zymogens. These events were detectable only within acinar cell pellets and not in the incubation medium, suggesting an intracellular site of conversion. The conversion of procarboxypeptidase A1 to its active form was inhibited by pretreatment with the weak base chloroquine (40 microM) and the protonophore monensin (10 microM). This conversion was also inhibited by pretreatment with the serine protease inhibitor benzamidine (10 mM) but not the cysteine protease inhibitor E64 (100 microM). The results suggest that high dose CCK stimulates the intracellular activation of digestive zymogens within isolated pancreatic acini. This event appears to require an acidic subcellular compartment and serine protease activity. Images PMID:1985109

Geomorphology and habitat diversity in the Pantanal.

PubMed

Mercante, M A; Rodrigues, S C; Ross, J L S

2011-04-01

The present study deals with the inter-relations in the relief which forms the Bacia do Alto Rio Paraguay (BAP) in mid-west Brazil. The overall aim is to discuss the relationship between relief forms and the biodiversity of the Pantanal. The BAP is a natural environmental system with contrasts in two of the compartments on which it is formed: the plateau, the most elevated compartment, highly transformed by human activities, and the plain which forms the Pantanal, which is more preserved and less transformed in relation to productive activities. The analysis was performed based on publications with a geomorphologic focus, examining the different relief units of the BAP and the dynamics of the revealing processes of landscape change which the Pantanal has undergone since the end of the Pleistocene.

The influence of differential processing of procathepsin H on its aminopeptidase activity, secretion and subcellular localization in human cell lines.

PubMed

Rojnik, Matija; Jevnikar, Zala R; Doljak, Bojan; Turk, Samo; Zidar, Nace; Kos, Janko

2012-10-01

Cathepsin H is a unique member of the cysteine cathepsins that acts primarily as an aminopeptidase. Like other cysteine cathepsins, it is synthesized as an inactive precursor and activated by proteolytic removal of its propeptide. Here we demonstrate that, in human cells, the processing of the propeptide is an autocatalytic, multistep process proceeding from an inactive 41kDa pro-form, through a 30kDa intermediate form, to the 28kDa mature form. Tyr87P and Gly90P were identified as the two major endopeptidase cleavage sites, converting the 30kDa form into the mature 28kDa form. The level of processing differs significantly in different human cell lines. In monocyte-derived macrophages U937 and prostate cancer cells PC-3, the 28kDa form is predominant, whereas in osteoblasts HOS the processing from the 30kDa form to the 28kDa form is significantly lower. The aminopeptidase activity of the enzyme and its subcellular localization are independent of the product, however the 30kDa form was not secreted in HOS cells. The activity of the resulting cathepsin H in U937 cells was significantly lower than that in HOS cells, presumably due to the high levels of endogenous cysteine protease inhibitor cystatin F present specifically in this cell line. These results provide an insight into the dependence of human cathepsin H processing and regulation on cell type. Copyright © 2012 Elsevier GmbH. All rights reserved.

Make It Metric.

ERIC Educational Resources Information Center

Camilli, Thomas

Measurement is perhaps the most frequently used form of mathematics. This book presents activities for learning about the metric system designed for upper intermediate and junior high levels. Discussions include: why metrics, history of metrics, changing to a metric world, teaching tips, and formulas. Activities presented are: metrics all around…

Temperature-insensitive vertical-cavity surface-emitting lasers and method for fabrication thereof

DOEpatents

Chow, W.W.; Choquette, K.D.; Gourley, P.L.

1998-01-27

A temperature-insensitive vertical-cavity surface-emitting laser (VCSEL) and method for fabrication thereof are disclosed. The temperature-insensitive VCSEL comprises a quantum-well active region within a resonant cavity, the active region having a gain spectrum with a high-order subband (n {>=} 2) contribution thereto for broadening and flattening the gain spectrum, thereby substantially reducing any variation in operating characteristics of the VCSEL over a temperature range of interest. The method for forming the temperature-insensitive VCSEL comprises the steps of providing a substrate and forming a plurality of layers thereon for providing first and second distributed Bragg reflector (DBR) mirror stacks with an active region sandwiched therebetween, the active region including at least one quantum-well layer providing a gain spectrum having a high-order subband (n {>=} 2) gain contribution, and the DBR mirror stacks having predetermined layer compositions and thicknesses for providing a cavity resonance within a predetermined wavelength range substantially overlapping the gain spectrum. 12 figs.

Temperature-insensitive vertical-cavity surface-emitting lasers and method for fabrication thereof

DOEpatents

Chow, Weng W.; Choquette, Kent D.; Gourley, Paul L.

1998-01-01

A temperature-insensitive vertical-cavity surface-emitting laser (VCSEL) and method for fabrication thereof. The temperature-insensitive VCSEL comprises a quantum-well active region within a resonant cavity, the active region having a gain spectrum with a high-order subband (n.gtoreq.2) contribution thereto for broadening and flattening the gain spectrum, thereby substantially reducing any variation in operating characteristics of the VCSEL over a temperature range of interest. The method for forming the temperature-insensitive VCSEL comprises the steps of providing a substrate and forming a plurality of layers thereon for providing first and second distributed Bragg reflector (DBR) mirror stacks with an active region sandwiched therebetween, the active region including at least one quantum-well layer providing a gain spectrum having a high-order subband (n.gtoreq.2) gain contribution, and the DBR mirror stacks having predetermined layer compositions and thicknesses for providing a cavity resonance within a predetermined wavelength range substantially overlapping the gain spectrum.

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification.

PubMed

Xue, Yiyun; Wang, Xiahui; Chen, Xingxuan; Hu, Jiajun; Gao, Min-Tian; Li, Jixiang

2017-06-01

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification were investigated in this study. All cellulases tested increased the contents of phenolic acids during saccharification. However, few free phenolic acids were detected, as they were present in conjugated form after saccharification when the cellulases from Trichoderma reesei, Trichoderma viride and Aspergillus niger were used. On the other hand, phenolic acids were present in free form when the Acremonium cellulolyticus cellulase was used. Assays of enzyme activity showed that, besides high cellulase activity, the A. cellulolyticus cellulase exhibited high feruloyl esterase (FAE) activity. A synergistic interaction between FAE and cellulase led to the increase in free phenolic acids, and thus an increase in antioxidative and antiradical activities of the phenolic acids. Moreover, a cost estimation demonstrated the feasibility of phenolic acids as value-added products to reduce the total production cost of ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regulation of a mammalian gene bearing a CpG island promoter and a distal enhancer.

PubMed

Berrozpe, Georgina; Bryant, Gene O; Warpinski, Katherine; Ptashne, Mark

2013-08-15

A quantitative nucleosome occupancy assay revealed rules for nucleosome disposition in yeast and showed how disposition affects regulation of the GAL genes. Here, we show how those findings apply to the control of Kit, a mammalian gene. The Kit promoter lies in a CpG island, and its enhancer (active in mast cells) lies some 150 kb upstream. Nucleosomes form with especially high avidities at the Kit promoter, a reaction that, we surmise, ensures extremely low basal expression. In mast cells, transcriptional activators displace nucleosomes that are less tightly formed at the Kit enhancer. In turn, the active enhancer replaces a single Kit promoter nucleosome with the transcriptional machinery, thereby inducing transcription over 1,000-fold. As at the yeast GAL genes, the inhibitory effects of nucleosomes facilitate high factors of induction by mammalian activators working in the absence of specific repressors. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Identification of novel superoxide dismutase isoenzymes in the olive (Olea europaea L.) pollen.

PubMed

Zafra, Adoración; Castro, Antonio Jesús; Alché, Juan de Dios

2018-06-08

Among antioxidant enzymes, the superoxide dismutase (SOD) family is a major actor in catalysing the disproportionation of superoxide. Apart from its role as antioxidant, these enzymes have a role in cell signalling, and Cu,Zn-SOD proteins are also major pollen allergens. In order to deepen our understanding of the SOD isoenzymes present in olive pollen and to analyse the molecular variability of the pollen Cu,Zn-SOD family, we carried out biochemical, transcriptomic and localization studies of pollen grains from different olive cultivars and other allergenic species. Olive pollen showed a high rate of total SOD activity in all cultivars assayed, which did not correlate with pollen viability. Mass spectrometry analysis together with activity assays and Western blotting experiments enabled us to identify new forms of Cu,Zn-SOD enzyme (including chloroplastidic and peroxisomal forms) as well as differentially expressed Mn-, Fe- and Cu,Zn-SOD isoenzymes among the pollen of different olive cultivars and allergenic species. Ultrastructural localization of Cu,Zn-SOD revealed its plastidial localization in the pollen grain. We also identified the occurrence of a shorter form of one of the cytosolic Cu,Zn-SOD enzymes, likely as the result of alternative splicing. This shorter enzyme showed lower SOD activity as compared to the full length form. The presence of multiple SOD isoenzymes in the olive pollen could be related to the need of finely tuning the ROS metabolism during the transition from its quiescent condition at maturity to a highly metabolically active state at germination.

Transcriptional Profiling Reveals a Common Metabolic Program for Tumorigenicity in High-Risk Human Neuroblastoma and Mouse Neuroblastoma Sphere-Forming Cells

PubMed Central

Liu, Mengling; Xia, Yingfeng; Ding, Jane; Ye, Bingwei; Zhao, Erhu; Choi, Jeong-Hyeon; Alptekin, Ahmet; Yan, Chunhong; Dong, Zheng; Huang, Shuang; Yang, Liqun; Cui, Hongjuan; Zha, Yunhong; Ding, Han-Fei

2017-01-01

Summary High-risk neuroblastoma remains one of the deadliest childhood cancers. Identification of metabolic pathways that drive or maintain high-risk neuroblastoma may open new avenues of therapeutic interventions. Here we report the isolation and propagation of neuroblastoma sphere-forming cells with self-renewal and differentiation potential from tumors of TH-MYCN mice, an animal model of high-risk neuroblastoma with MYCN amplification. Transcriptional profiling reveals that mouse neuroblastoma sphere-forming cells acquire a metabolic program characterized by transcriptional activation of the cholesterol and serine-glycine synthesis pathways, primarily as a result of increased expression of sterol regulatory element-binding factors and Atf4, respectively. This metabolic reprogramming is recapitulated in high-risk human neuroblastomas and is prognostic for poor clinical outcome. Genetic and pharmacological inhibition of the metabolic program markedly decreases the growth and tumorigenicity of both mouse neuroblastoma sphere-forming cells and human neuroblastoma cell lines. These findings suggest a therapeutic strategy for targeting the metabolic program of high-risk neuroblastoma. PMID:27705805

Transcriptional Profiling Reveals a Common Metabolic Program in High-Risk Human Neuroblastoma and Mouse Neuroblastoma Sphere-Forming Cells.

PubMed

Liu, Mengling; Xia, Yingfeng; Ding, Jane; Ye, Bingwei; Zhao, Erhu; Choi, Jeong-Hyeon; Alptekin, Ahmet; Yan, Chunhong; Dong, Zheng; Huang, Shuang; Yang, Liqun; Cui, Hongjuan; Zha, Yunhong; Ding, Han-Fei

2016-10-04

High-risk neuroblastoma remains one of the deadliest childhood cancers. Identification of metabolic pathways that drive or maintain high-risk neuroblastoma may open new avenues of therapeutic interventions. Here, we report the isolation and propagation of neuroblastoma sphere-forming cells with self-renewal and differentiation potential from tumors of the TH-MYCN mouse, an animal model of high-risk neuroblastoma with MYCN amplification. Transcriptional profiling reveals that mouse neuroblastoma sphere-forming cells acquire a metabolic program characterized by transcriptional activation of the cholesterol and serine-glycine synthesis pathways, primarily as a result of increased expression of sterol regulatory element binding factors and Atf4, respectively. This metabolic reprogramming is recapitulated in high-risk human neuroblastomas and is prognostic for poor clinical outcome. Genetic and pharmacological inhibition of the metabolic program markedly decreases the growth and tumorigenicity of both mouse neuroblastoma sphere-forming cells and human neuroblastoma cell lines. These findings suggest a therapeutic strategy for targeting the metabolic program of high-risk neuroblastoma. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

The SPARK Programs: A Public Health Model of Physical Education Research and Dissemination

ERIC Educational Resources Information Center

McKenzie, Thomas L.; Sallis, James F.; Rosengard, Paul; Ballard, Kymm

2016-01-01

SPARK [Sports, Play, and Active Recreation for Kids], in its current form, is a brand that represents a collection of exemplary, research-based, physical education and physical activity programs that emphasize a highly active curriculum, on-site staff development, and follow-up support. Given its complexity (e.g., multiple school levels, inclusion…

Parallel Computing:. Some Activities in High Energy Physics

NASA Astrophysics Data System (ADS)

Willers, Ian

This paper examines some activities in High Energy Physics that utilise parallel computing. The topic includes all computing from the proposed SIMD front end detectors, the farming applications, high-powered RISC processors and the large machines in the computer centers. We start by looking at the motivation behind using parallelism for general purpose computing. The developments around farming are then described from its simplest form to the more complex system in Fermilab. Finally, there is a list of some developments that are happening close to the experiments.

Oligosaccharide-based Surfactant/Citric Acid Buffer System Stabilizes Lactate Dehydrogenase during Freeze-drying and Storage without the Addition of Natural Sugar.

PubMed

Ogawa, Shigesaburo; Kawai, Ryuichiro; Koga, Maito; Asakura, Kouichi; Takahashi, Isao; Osanai, Shuichi

2016-06-01

Experiments were conducted to assess the maintenance effects of oligosaccharide-based surfactants on the enzymatic activity of a model protein, lactate dehydrogenase (LDH), during freeze-drying and room temperature storage using the citric acid buffer system. Oligosaccharide-based surfactants, which exhibit a high glass transition temperature (Tg), promoted the eminent retention of enzymatic activity during these protocols, whereas monosaccharide-based surfactants with a low Tg displayed poor performance at high concentration, albeit much better than that of Tween 80 at middle concentration. The increase in the alkyl chain length did not exert positive effects as observed for the maintenance effect during freeze-thawing, but an amphiphilic nature and a glass forming ability were crucial for the effective stabilization at a low excipient concentration during freeze-drying. Even a low oligosaccharide-based surfactant content (0.1 mg mL(-1)) could maintain LDH activity during freeze-drying, but a high surfactant content (1.0 mg mL(-1)) was required to prevent buffer precipitation and retain high LDH activity on storage. Regarding storage, glass formation restricted molecular mobility in the lyophilized matrix, and LDH activity was effectively retained. The present results describe a strategy based on the glass-forming ability of surfactant-type excipients that affords a natural sugar-free formulation or an alternative use for polysorbate-type surfactants.

Active superconducting devices formed of thin films

DOEpatents

Martens, Jon S.; Beyer, James B.; Nordman, James E.; Hohenwarter, Gert K. G.

1991-05-28

Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.

Cryo-electron microscopy structure of human peroxiredoxin-3 filament reveals the assembly of a putative chaperone.

PubMed

Radjainia, Mazdak; Venugopal, Hariprasad; Desfosses, Ambroise; Phillips, Amy J; Yewdall, N Amy; Hampton, Mark B; Gerrard, Juliet A; Mitra, Alok K

2015-05-05

Peroxiredoxins (Prxs) are a ubiquitous class of thiol-dependent peroxidases that play an important role in the protection and response of cells to oxidative stress. The catalytic unit of typical 2-Cys Prxs are homodimers, which can self-associate to form complex assemblies that are hypothesized to have signaling and chaperone activity. Mitochondrial Prx3 forms dodecameric toroids, which can further stack to form filaments, the so-called high-molecular-weight (HMW) form that has putative holdase activity. We used single-particle analysis and helical processing of electron cryomicroscopy images of human Prx3 filaments induced by low pH to generate a ∼7-Å resolution 3D structure of the HMW form, the first such structure for a 2-Cys Prx. The pseudo-atomic model reveals interactions that promote the stacking of the toroids and shows that unlike previously reported data, the structure can accommodate a partially folded C terminus. The HMW filament lumen displays hydrophobic patches, which we hypothesize bestow holdase activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cholesterol-lowering drugs cause dissolution of cholesterol crystals and disperse Kupffer cell crown-like structures during resolution of NASH

PubMed Central

Ioannou, George N.; Van Rooyen, Derrick M.; Savard, Christopher; Haigh, W. Geoffrey; Yeh, Matthew M.; Teoh, Narci C.; Farrell, Geoffrey C.

2015-01-01

Cholesterol crystals form within hepatocyte lipid droplets in human and experimental nonalcoholic steatohepatitis (NASH) and are the focus of crown-like structures (CLSs) of activated Kupffer cells (KCs). Obese, diabetic Alms1 mutant (foz/foz) mice were a fed high-fat (23%) diet containing 0.2% cholesterol for 16 weeks and then assigned to four intervention groups for 8 weeks: a) vehicle control, b) ezetimibe (5 mg/kg/day), c) atorvastatin (20 mg/kg/day), or d) ezetimibe and atorvastatin. Livers of vehicle-treated mice developed fibrosing NASH with abundant cholesterol crystallization within lipid droplets calculated to extend over 3.3% (SD, 2.2%) of liver surface area. Hepatocyte lipid droplets with prominent cholesterol crystallization were surrounded by TNFα-positive (activated) KCs forming CLSs (≥3 per high-power field). KCs that formed CLSs stained positive for NLRP3, implicating activation of the NLRP3 inflammasome in response to cholesterol crystals. In contrast, foz/foz mice treated with ezetimibe and atorvastatin showed near-complete resolution of cholesterol crystals [0.01% (SD, 0.02%) of surface area] and CLSs (0 per high-power field), with amelioration of fibrotic NASH. Ezetimibe or atorvastatin alone had intermediate effects on cholesterol crystallization, CLSs, and NASH. These findings are consistent with a causative link between exposure of hepatocytes and KCs to cholesterol crystals and with the development of NASH possibly mediated by NLRP3 activation. PMID:25520429

Cholesterol-lowering drugs cause dissolution of cholesterol crystals and disperse Kupffer cell crown-like structures during resolution of NASH.

PubMed

Ioannou, George N; Van Rooyen, Derrick M; Savard, Christopher; Haigh, W Geoffrey; Yeh, Matthew M; Teoh, Narci C; Farrell, Geoffrey C

2015-02-01

Cholesterol crystals form within hepatocyte lipid droplets in human and experimental nonalcoholic steatohepatitis (NASH) and are the focus of crown-like structures (CLSs) of activated Kupffer cells (KCs). Obese, diabetic Alms1 mutant (foz/foz) mice were a fed high-fat (23%) diet containing 0.2% cholesterol for 16 weeks and then assigned to four intervention groups for 8 weeks: a) vehicle control, b) ezetimibe (5 mg/kg/day), c) atorvastatin (20 mg/kg/day), or d) ezetimibe and atorvastatin. Livers of vehicle-treated mice developed fibrosing NASH with abundant cholesterol crystallization within lipid droplets calculated to extend over 3.3% (SD, 2.2%) of liver surface area. Hepatocyte lipid droplets with prominent cholesterol crystallization were surrounded by TNFα-positive (activated) KCs forming CLSs (≥ 3 per high-power field). KCs that formed CLSs stained positive for NLRP3, implicating activation of the NLRP3 inflammasome in response to cholesterol crystals. In contrast, foz/foz mice treated with ezetimibe and atorvastatin showed near-complete resolution of cholesterol crystals [0.01% (SD, 0.02%) of surface area] and CLSs (0 per high-power field), with amelioration of fibrotic NASH. Ezetimibe or atorvastatin alone had intermediate effects on cholesterol crystallization, CLSs, and NASH. These findings are consistent with a causative link between exposure of hepatocytes and KCs to cholesterol crystals and with the development of NASH possibly mediated by NLRP3 activation.

Effective rate constants for nanostructured heterogeneous catalysts

NASA Astrophysics Data System (ADS)

Hendy, Shaun; Gaston, Nicola; Zhang, Philip; Lund, Nat

2012-02-01

There is currently a high level of interest in the use of nanostructured materials for catalysis. For instance, gold, which is largely inert in the bulk, can exhibit strong catalytic activity when in nanoparticle form. With precious metal catalysts such as Pt and Pd in high demand, the use of these materials in nanoparticle form can also substantially reduce costs by exposure of more surface area for the same volume of material. When reactants are plentiful, the effective activity of a nanoparticulate catalyst will increase roughly with its surface area. However, under diffusion-limited conditions, the reactant must diffuse to active sites on the catalyst, so a high surface area and a high density of active sites may bring diminishing returns if reactant is consumed faster than it arrives. Here we apply a mathematical homogenisation approach to derive simple expressions for the effective reactivity of a nanostructured catalyst under diffusion limited conditions that relate the intrinsic rate constants of the surfaces presented by the catalyst to an effective rate constant. When highly active catalytic sites, such as step edges or other defects are present, we show that distinct limiting cases emerge depending on the degree of overlap of the reactant depletion zone about each site. In gases, the size of this depletion zone is approximately the mean free path, so the effective reactivity will depend on the structure of the catalyst on that scale. We discuss implications for the optimal design of nanoparticle catalysts.

Enhancement of solubility, purification and inclusion-bodies-refolding of an active pectin lyase from Penicillium occitanis expressed in Escherichia coli.

PubMed

Hadj Sassi, Azza; Trigui-Lahiani, Hèla; Abdeljalil, Salma; Gargouri, Ali

2017-02-01

Pectin lyase (pnl) is the only pectinase able to hydrolyze directly the highly methylated pectin without liberating the toxic methanol and without disturbing ester content responsible for specific aroma of juices. The cDNA of Penicillium occitanis pnl (mature form) was cloned into pET-21a as expression vector and over-expressed into Esherichia coli. Most of recombinant pnl was expressed as inclusion bodies. Pnl activity was confirmed by colorimetric assay. To enhance the solubility yield of the expressed pnl, the effects of induction temperature, host strain and expression level were optimized. Maximal production of functional pnl was obtained after induction by 0.4mM IPTG at 30°C and 150rpm for 16h. Interestingly, the use of Origami host strain, having an oxidized cytoplasm favoring disulfide bonds formation required for the active conformation of the enzyme, has significantly improved the yield of the soluble active form of recombinant pnl. This pnl was successfully purified through a single step purification using His-Trap affinity column chromatography. This work is the first to report pnl expression into Origami strain. Alternatively, the inclusion bodies were isolated, denatured by high concentration of urea and gradually refolded by successive dialysis, leading to their transformation into soluble and active form. Copyright © 2016 Elsevier B.V. All rights reserved.

Activated carbon fiber composite material and method of making

DOEpatents

Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

2000-01-01

An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

Activated carbon fiber composite material and method of making

DOEpatents

Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

2001-01-01

An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

Self-Formed Channel Devices Based on Vertically Grown 2D Materials with Large-Surface-Area and Their Potential for Chemical Sensor Applications.

PubMed

Kim, Chaeeun; Park, Jun-Cheol; Choi, Sun Young; Kim, Yonghun; Seo, Seung-Young; Park, Tae-Eon; Kwon, Se-Hun; Cho, Byungjin; Ahn, Ji-Hoon

2018-04-01

2D layered materials with sensitive surfaces are promising materials for use in chemical sensing devices, owing to their extremely large surface-to-volume ratios. However, most chemical sensors based on 2D materials are used in the form of laterally defined active channels, in which the active area is limited to the actual device dimensions. Therefore, a novel approach for fabricating self-formed active-channel devices is proposed based on 2D semiconductor materials with very large surface areas, and their potential gas sensing ability is examined. First, the vertical growth phenomenon of SnS 2 nanocrystals is investigated with large surface area via metal-assisted growth using prepatterned metal electrodes, and then self-formed active-channel devices are suggested without additional pattering through the selective synthesis of SnS 2 nanosheets on prepatterned metal electrodes. The self-formed active-channel device exhibits extremely high response values (>2000% at 10 ppm) for NO 2 along with excellent NO 2 selectivity. Moreover, the NO 2 gas response of the gas sensing device with vertically self-formed SnS 2 nanosheets is more than two orders of magnitude higher than that of a similar exfoliated SnS 2 -based device. These results indicate that the facile device fabrication method would be applicable to various systems in which surface area plays an important role. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective Targeting of High-Affinity LFA-1 Does Not Augment Costimulation Blockade in a Nonhuman Primate Renal Transplantation Model

PubMed Central

Samy, KP; Anderson, DA; Lo, DJ; Mulvihill, MS; Song, M; Farris, AB; Parker, BS; MacDonald, AL; Lu, C; Springer, TA; Kachlany, SC; Reimann, KA; How, T; Leopardi, FV; Franke, KS; Williams, KD; Collins, BH; Kirk, AD

2016-01-01

Costimulation blockade (CoB) via belatacept is a lower morbidity alternative to calcineurin inhibitor (CNI)-based immunosuppression. However, it has higher rates of early acute rejection. These early rejections are mediated in part by memory T cells, which have reduced dependence on the pathway targeted by belatacept, and increased adhesion molecule expression. One such molecule is Leukocyte Function Associated Antigen (LFA)-1. LFA-1 exists in two forms, a commonly expressed, low-affinity form, and a transient, high-affinity form, expressed only during activation. We have shown that antibodies reactive with LFA-1 irrespective of its configuration are effective in eliminating memory T cells, but at the cost of impaired protective immunity. Here we test two novel agents, Leukotoxin A and AL-579, each of which targets the high affinity form of LFA-1, to determine whether this more precise targeting prevents belatacept-resistant rejection. Despite evidence of ex vivo and in vivo ligand-specific activity, neither agent when combined with belatacept proved superior to belatacept monotherapy. Leukotoxin A approached a ceiling of toxicity prior to efficacy, while AL-579 failed to significantly alter the peripheral immune response. These data, and prior studies, suggest that LFA-1 blockade may not be a suitable adjuvant agent for CoB resistant rejection. PMID:27888551

Interfacial activity in alkaline flooding enhanced oil recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, M.K.

1981-01-01

The ionization of long-chained organic acids in the crude oil to form soaps was shown to be primarily responsible for the lowering of oil-water interfacial tension at alkaline pH. These active acids can be concentrated by silica gel chromatography into a minor polar fraction. An equilibrium chemical model was proposed based on 2 competing reactions: the ionization of acids to form active anions, and the formation of undissociated soap between acid anions and sodium ions. It correlates the interfacial activity with the interfacial concentration of active acid anions which is expressed in terms of the concentrations of the chemical speciesmore » in the system. The model successfully predicts the observed oil-alkaline solution interfacial phenomenon, including its dependence on pH, alkali and salt concentrations, type of acid present and type of soap formed. Flooding at different alkali concentrations to activate different acid species present in the crude was shown to give better recovery than flooding at a single high alkali concentration. Treating the crude oil with a dilute solution of mineral acids liberates additional free active acids and yields better interfacial activity during subsequent alkali contact.« less

Anatomical Substrates of Visual and Auditory Miniature Second-language Learning

PubMed Central

Newman-Norlund, Roger D.; Frey, Scott H.; Petitto, Laura-Ann; Grafton, Scott T.

2007-01-01

Longitudinal changes in brain activity during second language (L2) acquisition of a miniature finite-state grammar, named Wernickese, were identified with functional magnetic resonance imaging (fMRI). Participants learned either a visual sign language form or an auditory-verbal form to equivalent proficiency levels. Brain activity during sentence comprehension while hearing/viewing stimuli was assessed at low, medium, and high levels of proficiency in three separate fMRI sessions. Activation in the left inferior frontal gyrus (Broca’s area) correlated positively with improving L2 proficiency, whereas activity in the right-hemisphere (RH) homologue was negatively correlated for both auditory and visual forms of the language. Activity in sequence learning areas including the premotor cortex and putamen also correlated with L2 proficiency. Modality-specific differences in the blood oxygenation level-dependent signal accompanying L2 acquisition were localized to the planum temporale (PT). Participants learning the auditory form exhibited decreasing reliance on bilateral PT sites across sessions. In the visual form, bilateral PT sites increased in activity between Session 1 and Session 2, then decreased in left PT activity from Session 2 to Session 3. Comparison of L2 laterality (as compared to L1 laterality) in auditory and visual groups failed to demonstrate greater RH lateralization for the visual versus auditory L2. These data establish a common role for Broca’s area in language acquisition irrespective of the perceptual form of the language and suggest that L2s are processed similar to first languages even when learned after the ‘‘critical period.’’ The right frontal cortex was not preferentially recruited by visual language after accounting for phonetic/structural complexity and performance. PMID:17129186

Broadband acoustic phased array with subwavelength active tube array

NASA Astrophysics Data System (ADS)

Li, Xiao-Yan; Yang, Zhang-Zhao; Zhu, Yi-Fan; Zou, Xin-Ye; Cheng, Jian-Chun

2018-02-01

Acoustic metasurfaces provide a way to manipulate wavefronts at anomalous reflection or refraction angles through subwavelength structures. Here, based on the generalized Snell's refraction law for acoustic metasurfaces and the classical acoustic phased array (PA) theory, a broadband acoustic PA with a subwavelength active tube array has been proposed to form a special acoustic beam and to determine the directivity characteristics of the acoustic source. Theoretical analysis shows that the dispersionless wavefront manipulation can be realized by the gradient model of the active tube array, and a wide working frequency band can be obtained in practical applications from the simulated and experimental results. The numerical results of forming a special acoustic beam and establishing an acoustic focus model with an arbitrary focal position are consistent with the theoretical predictions. The experimental results agree well with the simulated results in the model of forming the acoustic beam of 45 ° . By combining acoustic metamaterials and conventional acoustic PA, the model of the active tube array paves a way to design a composite acoustic PA with high radiation efficiency and system robustness without the need for any complex circuit control system. This design concept is expected to be used in the design of ultrasonic therapy devices and high-efficiency transducers.

Method of preparing corrosion resistant composite materials

DOEpatents

Kaun, Thomas D.

1993-01-01

Method of manufacture of ceramic materials which require stability in severely-corrosive environment having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These surfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Structures of human thymidylate synthase R163K with dUMP, FdUMP and glutathione show asymmetric ligand binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibson, Lydia M.; Celeste, Lesa R.; Lovelace, Leslie L.

Thymidylate synthase (TS) is a well validated target in cancer chemotherapy. Here, a new crystal form of the R163K variant of human TS (hTS) with five subunits per asymmetric part of the unit cell, all with loop 181-197 in the active conformation, is reported. This form allows binding studies by soaking crystals in artificial mother liquors containing ligands that bind in the active site. Using this approach, crystal structures of hTS complexes with FdUMP and dUMP were obtained, indicating that this form should facilitate high-throughput analysis of hTS complexes with drug candidates. Crystal soaking experiments using oxidized glutathione revealed thatmore » hTS binds this ligand. Interestingly, the two types of binding observed are both asymmetric. In one subunit of the physiological dimer covalent modification of the catalytic nucleophile Cys195 takes place, while in another dimer a noncovalent adduct with reduced glutathione is formed in one of the active sites.« less

Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

DOEpatents

Apel, Charles T.; Layman, Lawrence R.; Gallimore, David L.

1988-01-01

A nebulizer for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets.

Secondary treatment of films of colloidal quantum dots for optoelectronics and devices produced thereby

DOEpatents

Semonin, Octavi Escala; Luther, Joseph M; Beard, Matthew C; Chen, Hsiang-Yu

2014-04-01

A method of forming an optoelectronic device. The method includes providing a deposition surface and contacting the deposition surface with a ligand exchange chemical and contacting the deposition surface with a quantum dot (QD) colloid. This initial process is repeated over one or more cycles to form an initial QD film on the deposition surface. The method further includes subsequently contacting the QD film with a secondary treatment chemical and optionally contacting the surface with additional QDs to form an enhanced QD layer exhibiting multiple exciton generation (MEG) upon absorption of high energy photons by the QD active layer. Devices having an enhanced QD active layer as described above are also disclosed.

High-frequency rapid B-mode ultrasound imaging for real-time monitoring of lesion formation and gas body activity during high-intensity focused ultrasound ablation.

PubMed

Gudur, Madhu Sudhan Reddy; Kumon, Ronald E; Zhou, Yun; Deng, Cheri X

2012-08-01

The goal of this study was to examine the ability of high-frame-rate, high-resolution imaging to monitor tissue necrosis and gas-body activities formed during high-intensity focused ultrasound (HIFU) application. Ex vivo porcine cardiac tissue specimens (n = 24) were treated with HIFU exposure (4.33 MHz, 77 to 130 Hz pulse repetition frequency (PRF), 25 to 50% duty cycle, 0.2 to 1 s, 2600 W/cm(2)). RF data from B-mode ultrasound imaging were obtained before, during, and after HIFU exposure at a frame rate ranging from 77 to 130 Hz using an ultrasound imaging system with a center frequency of 55 MHz. The time history of changes in the integrated backscatter (IBS), calibrated spectral parameters, and echo-decorrelation parameters of the RF data were assessed for lesion identification by comparison against gross sections. Temporal maximum IBS with +12 dB threshold achieved the best identification with a receiver-operating characteristic (ROC) curve area of 0.96. Frame-to-frame echo decorrelation identified and tracked transient gas-body activities. Macroscopic (millimeter-sized) cavities formed when the estimated initial expansion rate of gas bodies (rate of expansion in lateral-to-beam direction) crossed 0.8 mm/s. Together, these assessments provide a method for monitoring spatiotemporal evolution of lesion and gas-body activity and for predicting macroscopic cavity formation.

Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues.

PubMed

Kourti, Ioanna; Rani, D Amutha; Deegan, D; Boccaccini, A R; Cheeseman, C R

2010-04-15

Air pollution control (APC) residues are the hazardous waste produced from cleaning gaseous emissions at energy-from-waste (EfW) facilities processing municipal solid waste (MSW). APC residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium alumino-silicate glass. This research has investigated the optimisation and properties of geopolymers prepared from this glass. Work has shown that high strength geopolymers can be formed and that the NaOH concentration of the activating solution significantly affects the properties. The broad particle size distribution of the APC residue glass used in these experiments results in a microstructure that contains unreacted glass particles included within a geopolymer binder phase. The high calcium content of APC residues may cause the formation of some amorphous calcium silicate hydrate (C-S-H) gel. A mix prepared with S/L=3.4, Si/Al=2.6 and [NaOH]=6M in the activating solution, produced high strength geopolymers with compressive strengths of approximately 130 MPa. This material had high density (2070 kg/m(3)) and low porosity. The research demonstrates for the first time that glass derived from DC plasma treatment of APC residues can be used to form high strength geopolymer-glass composites that have potential for use in a range of applications. 2009 Elsevier B.V. All rights reserved.

Proteolytic interconversion and N-terminal sequences of the Citrobacter diversus major beta-lactamases.

PubMed Central

Franceschini, N; Amicosante, G; Perilli, M; Maccarrone, M; Oratore, A; van Beeumen, J; Frère, J M

1991-01-01

The N-terminal sequences of the two major beta-lactamases produced by Citrobacter diversus differed only by the absence of the first residue in form II and the loss of five amino acid residues at the C-terminal end. Limited proteolysis of the homogeneous form I protein yielded a variety of enzymatically active products. In the major product obtained after the action of papain, the first three N-terminal residues of form I had been cleaved, whereas at the C-terminal end the treated enzyme lacked five residues. However, this cannot explain the different behaviours of form I, form II and papain digestion product upon chromatofocusing. Form I, which was sequenced up to position 56, exhibited a very high degree of similarity with a Klebsiella oxytoca beta-lactamase. The determined sequence, which contained the active serine residue, demonstrated that the chromosome-encoded beta-lactamase of Citrobacter diversus belong to class A. Images Fig. 2. PMID:2039443

Physical activity and alcohol use disorders.

PubMed

Lisha, Nadra E; Sussman, Steve; Fapa, Faahb; Leventhal, Adam M

2013-03-01

Prior research has documented a counterintuitive positive association between physical activity and indices of alcohol consumption frequency and heaviness. To investigate whether this relation extends to alcohol use disorder and clarify whether this association is non-linear. This is a cross-sectional, correlational population-based study of US adults (N = 34,653). The Alcohol Use Disorder and Associated Disabilities Interview Schedule was used to classify past-year DSM-IV alcohol use disorder and self-reported federal government-recommended weekly physical activity cutoffs. After statistically controlling for confounds, alcohol abuse but not dependence was associated with greater prevalence of physical activity. Number of alcohol use disorder symptoms exhibited a curvilinear relationship with meeting physical activity requirements, such that the positive association degraded with high symptom counts. There is a positive association between physical activity and less severe forms of alcohol use disorder in US adults. More severe forms of alcohol use disorder are not associated with physical activity.

Glomus fasciculatum Fungi as a Bio-convertor and Bio-activator of Inorganic and Organic P in Dual Symbiosis.

PubMed

Azmat, Rafia; Hamid, Neelofer; Moin, Sumeira; Saleem, Ailyan

2016-01-01

Dual symbiosis played an effective role in drought condition and temperature. Furthermore, performed services in absorption of water and solubilization of chief nutrients specially phosphorus for growth of plants. Phosphorous is essential for plant growth in any climatic condition because of central constituent of ATP providing chemical energy for all metabolic reactions of plants. The goal of this work was to monitor the growth of plant under three climatic conditions in comparison to control plant under Glomus fasciculatum inoculation related with adequate supply of phosphorous. Results demonstrated that Glomus fasciculatum (VAM) activates the solubilization of P into the anionic form H2PO4(-) which is highly consumable form by the plants. Minerals including P in soil most regularly solubilized for fixing in plants and continuously changed to highly soluble forms by reaction with inorganic or organic constituents of the soil which are activated in the presence of fungi for continuous availability. Experimental facts and nonstop growth of plants recommended that VAM fungi act as a bio-convertor and bio-activator of soil nutrients, especially of P and their hyphal interaction absorbs soil nutrients and activates insoluble P to soluble one for plant development. Continuous growth of 18 months old Conocarpus erectus L plant in dual symbiosis supports the proposed idea that phosphorus cycle exists during VAM inoculations, where soil reaction altered in presence of spores that help to solubilize the P which strengthens the plant, activates photo-biological activity and demonstrates the new function of VAM as a recycler for continues growth.

High specific activity platinum-195m

DOEpatents

Mirzadeh, Saed; Du, Miting; Beets, Arnold L.; Knapp, Jr., Furn F.

2004-10-12

A new composition of matter includes .sup.195m Pt characterized by a specific activity of at least 30 mCi/mg Pt, generally made by method that includes the steps of: exposing .sup.193 Ir to a flux of neutrons sufficient to convert a portion of the .sup.193 Ir to .sup.195m Pt to form an irradiated material; dissolving the irradiated material to form an intermediate solution comprising Ir and Pt; and separating the Pt from the Ir by cation exchange chromatography to produce .sup.195m Pt.

Mitigation of NADPH Oxidase 2 Activity as a Strategy to Inhibit Peroxynitrite Formation*

PubMed Central

Zielonka, Jacek; Zielonka, Monika; VerPlank, Lynn; Cheng, Gang; Hardy, Micael; Ouari, Olivier; Ayhan, Mehmet Menaf; Podsiadły, Radosław; Sikora, Adam; Lambeth, J. David; Kalyanaraman, Balaraman

2016-01-01

Using high throughput screening-compatible assays for superoxide and hydrogen peroxide, we identified potential inhibitors of the NADPH oxidase (Nox2) isoform from a small library of bioactive compounds. By using multiple probes (hydroethidine, hydropropidine, Amplex Red, and coumarin boronate) with well defined redox chemistry that form highly diagnostic marker products upon reaction with superoxide (O2˙̄), hydrogen peroxide (H2O2), and peroxynitrite (ONOO−), the number of false positives was greatly decreased. Selected hits for Nox2 were further screened for their ability to inhibit ONOO− formation in activated macrophages. A new diagnostic marker product for ONOO− is reported. We conclude that the newly developed high throughput screening/reactive oxygen species assays could also be used to identify potential inhibitors of ONOO− formed from Nox2-derived O2˙̄ and nitric oxide synthase-derived nitric oxide. PMID:26839313

Process for preparing multilayer enzyme coating on a fiber

DOEpatents

Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

2009-11-03

A process for preparing high stability, high activity biocatalytic materials is disclosed and processes for using the same. The process involves coating of a material or fiber with enzymes and enzyme aggregate providing a material or fiber with high biocatalytic activity and stability useful in heterogeneous environments. In one illustrative approach, enzyme "seeds" are covalently attached to polymer nanofibers followed by treatment with a reagent that crosslinks additional enzyme molecules to the seed enzymes forming enzyme aggregates thereby improving biocatalytic activity due to increased enzyme loading and enzyme stability. This approach creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, biosensors, and biofuel cells.

PROBLEM OF FORMING IN A MAN-OPERATOR A HABIT OF TRACKING A MOVING TARGET,

DTIC Science & Technology

Cybernetics stimulated the large-scale use of the method of functional analogy which makes it possible to compare technical and human activity systems...interesting and highly efficient human activity because of the psychological control factor involved in its operation. The human tracking system is

Modulation of Brain Activity during Phonological Familiarization

ERIC Educational Resources Information Center

Majerus, S.; Van der Linden, M.; Collette, F.; Laureys, S.; Poncelet, M.; Degueldre, C.; Delfiore, G.; Luxen, A.; Salmon, E.

2005-01-01

We measured brain activity in 12 adults for the repetition of auditorily presented words and nonwords, before and after repeated exposure to their phonological form. The nonword phoneme combinations were either of high (HF) or low (LF) phonotactic frequency. After familiarization, we observed, for both word and nonword conditions, decreased…

Hit to lead account of the discovery of bisbenzamide and related ureidobenzamide inhibitors of Rho kinase.

PubMed

Morwick, Tina; Büttner, Frank H; Cywin, Charles L; Dahmann, Georg; Hickey, Eugene; Jakes, Scott; Kaplita, Paul; Kashem, Mohammed A; Kerr, Steven; Kugler, Stanley; Mao, Wang; Marshall, Daniel; Paw, Zofia; Shih, Cheng-Kon; Wu, Frank; Young, Erick

2010-01-28

A highly selective series of bisbenzamide inhibitors of Rho-associated coiled-coil forming protein kinase (ROCK) and a related ureidobenzamide series, both identified by high throughput screening (HTS), are described. Details of the hit validation and lead generation process, including structure-activity relationship (SAR) studies, a selectivity assessment, target-independent profiling (TIP) results, and an analysis of functional activity using a rat aortic ring assay are discussed.

Air Activated Self-Decontaminating Polydicyclopentadiene PolyHIPE Foams for Rapid Decontamination of Chemical Warfare Agents.

PubMed

McGann, Christopher L; Daniels, Grant C; Giles, Spencer L; Balow, Robert B; Miranda-Zayas, Jorge L; Lundin, Jeffrey G; Wynne, James H

2018-06-01

The threat of chemical warfare agents (CWA) compels research into novel self-decontaminating materials (SDM) for the continued safety of first-responders, civilians, and active service personnel. The capacity to actively detoxify, as opposed to merely sequester, offending agents under typical environmental conditions defines the added value of SDMs in comparison to traditional adsorptive materials. Porous polymers, synthesized via the high internal phase emulsion (HIPE) templating, provide a facile fabrication method for materials with permeable open cellular structures that may serve in air filtration applications. PolyHIPEs comprising polydicyclopentadiene (polyDCPD) networks form stable hydroperoxide species following activation in air under ambient conditions. The hydroperoxide-containing polyDCPD materials react quickly with CWA simulants, Demeton-S and 2-chloroethyl ethyl sulfide, forming oxidation products as confirmed via gas chromatography mass spectrometry. The simplicity of the detoxification chemistry paired with the porous foam form factor presents an exciting opportunity for the development of self-decontaminating filter media. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Does the Sound of a Barking Dog Activate its Corresponding Visual Form? An fMRI Investigation of Modality-Specific Semantic Access

PubMed Central

Reilly, Jamie; Garcia, Amanda; Binney, Richard J.

2016-01-01

Much remains to be learned about the neural architecture underlying word meaning. Fully distributed models of semantic memory predict that the sound of a barking dog will conjointly engage a network of distributed sensorimotor spokes. An alternative framework holds that modality-specific features additionally converge within transmodal hubs. Participants underwent functional MRI while covertly naming familiar objects versus newly learned novel objects from only one of their constituent semantic features (visual form, characteristic sound, or point-light motion representation). Relative to the novel object baseline, familiar concepts elicited greater activation within association regions specific to that presentation modality. Furthermore, visual form elicited activation within high-level auditory association cortex. Conversely, environmental sounds elicited activation in regions proximal to visual association cortex. Both conditions commonly engaged a putative hub region within lateral anterior temporal cortex. These results support hybrid semantic models in which local hubs and distributed spokes are dually engaged in service of semantic memory. PMID:27289210

Structure- and reactivity-based development of covalent inhibitors of the activating and gatekeeper mutant forms of the epidermal growth factor receptor (EGFR).

PubMed

Ward, Richard A; Anderton, Mark J; Ashton, Susan; Bethel, Paul A; Box, Matthew; Butterworth, Sam; Colclough, Nicola; Chorley, Christopher G; Chuaqui, Claudio; Cross, Darren A E; Dakin, Les A; Debreczeni, Judit É; Eberlein, Cath; Finlay, M Raymond V; Hill, George B; Grist, Matthew; Klinowska, Teresa C M; Lane, Clare; Martin, Scott; Orme, Jonathon P; Smith, Peter; Wang, Fengjiang; Waring, Michael J

2013-09-12

A novel series of small-molecule inhibitors has been developed to target the double mutant form of the epidermal growth factor receptor (EGFR) tyrosine kinase, which is resistant to treatment with gefitinib and erlotinib. Our reported compounds also show selectivity over wild-type EGFR. Guided by molecular modeling, this series was evolved to target a cysteine residue in the ATP binding site via covalent bond formation and demonstrates high levels of activity in cellular models of the double mutant form of EGFR. In addition, these compounds show significant activity against the activating mutations, which gefitinib and erlotinib target and inhibition of which gives rise to their observed clinical efficacy. A glutathione (GSH)-based assay was used to measure thiol reactivity toward the electrophilic functionality of the inhibitor series, enabling both the identification of a suitable reactivity window for their potency and the development of a reactivity quantitative structure-property relationship (QSPR) to support design.

Hda Monomerization by ADP Binding Promotes Replicase Clamp-mediated DnaA-ATP Hydrolysis*S⃞

PubMed Central

Su'etsugu, Masayuki; Nakamura, Kenta; Keyamura, Kenji; Kudo, Yuka; Katayama, Tsutomu

2008-01-01

ATP-DnaA is the initiator of chromosomal replication in Escherichia coli, and the activity of DnaA is regulated by the regulatory inactivation of the DnaA (RIDA) system. In this system, the Hda protein promotes DnaA-ATP hydrolysis to produce inactive ADP-DnaA in a mechanism that is mediated by the DNA-loaded form of the replicase sliding clamp. In this study, we first revealed that hda translation uses an unusual initiation codon, CUG, located downstream of the annotated initiation codon. The CUG initiation codon could be used for restricting the Hda level, as this initiation codon has a low translation efficiency, and the cellular Hda level is only ∼100 molecules per cell. Hda translated using the correct reading frame was purified and found to have a high RIDA activity in vitro. Moreover, we found that Hda has a high affinity for ADP but not for other nucleotides, including ATP. ADP-Hda was active in the RIDA system in vitro and stable in a monomeric state, whereas apo-Hda formed inactive homomultimers. Both ADP-Hda and apo-Hda could form complexes with the DNA-loaded clamp; however, only ADP-Hda-DNA-clamp complexes were highly functional in the following interaction with DnaA. Formation of ADP-Hda was also observed in vivo, and mutant analysis suggested that ADP binding is crucial for cellular Hda activity. Thus, we propose that ADP is a crucial Hda ligand that promotes the activated conformation of the protein. ADP-dependent monomerization might enable the arginine finger of the Hda AAA+ domain to be accessible to ATP bound to the DnaA AAA+ domain. PMID:18977760

Hda monomerization by ADP binding promotes replicase clamp-mediated DnaA-ATP hydrolysis.

PubMed

Su'etsugu, Masayuki; Nakamura, Kenta; Keyamura, Kenji; Kudo, Yuka; Katayama, Tsutomu

2008-12-26

ATP-DnaA is the initiator of chromosomal replication in Escherichia coli, and the activity of DnaA is regulated by the regulatory inactivation of the DnaA (RIDA) system. In this system, the Hda protein promotes DnaA-ATP hydrolysis to produce inactive ADP-DnaA in a mechanism that is mediated by the DNA-loaded form of the replicase sliding clamp. In this study, we first revealed that hda translation uses an unusual initiation codon, CUG, located downstream of the annotated initiation codon. The CUG initiation codon could be used for restricting the Hda level, as this initiation codon has a low translation efficiency, and the cellular Hda level is only approximately 100 molecules per cell. Hda translated using the correct reading frame was purified and found to have a high RIDA activity in vitro. Moreover, we found that Hda has a high affinity for ADP but not for other nucleotides, including ATP. ADP-Hda was active in the RIDA system in vitro and stable in a monomeric state, whereas apo-Hda formed inactive homomultimers. Both ADP-Hda and apo-Hda could form complexes with the DNA-loaded clamp; however, only ADP-Hda-DNA-clamp complexes were highly functional in the following interaction with DnaA. Formation of ADP-Hda was also observed in vivo, and mutant analysis suggested that ADP binding is crucial for cellular Hda activity. Thus, we propose that ADP is a crucial Hda ligand that promotes the activated conformation of the protein. ADP-dependent monomerization might enable the arginine finger of the Hda AAA+ domain to be accessible to ATP bound to the DnaA AAA+ domain.

Functional analysis of thioredoxin from the desert lichen-forming fungus, Endocarpon pusillum Hedwig, reveals its role in stress tolerance

PubMed Central

Li, Hui; Wei, Jiang-Chun

2016-01-01

Endocarpon pusillum is a lichen-forming fungus with an outstanding stress resistance property closely related to its antioxidant system. In this study, thioredoxin (Trx), one of the main components of antioxidant defense systems in E. pusillum (EpTrx), was characterized and analyzed both in transgenic yeasts and in vitro. Our analyses identified that the heterologous expression of EpTrx in the yeast Pichia pastoris significantly enhanced its resistance to osmotic and oxidative stresses. Assays in vitro showed EpTrx acted as a disulfide reductase as well as a molecular chaperone by assembling into various polymeric structures. Upon exposure to heat-shock stress, EpTrx exhibited weaker disulfide reductase activity but stronger chaperone activity, which coincided with the switching of the protein complexes from low molecular weight forms to high molecular weight complexes. Specifically, we found that Cys31 near but not at the active site was crucial in promoting the structural and functional transitions, most likely by accelerating the formation of intermolecular disulfide bond. Transgenic Saccharomyces cerevisiae harboring the native EpTrx exhibited stronger tolerance to oxidative, osmotic and high temperature stresses than the corresponding yeast strain containing the mutant EpTrx (C31S). Our results provide the first molecular evidence on how Trx influences stress response in lichen-forming fungi. PMID:27251605

An Information Literacy Partnership.

ERIC Educational Resources Information Center

Bielich, Paul; Page, Frederick

2002-01-01

Describes a pilot partnership formed by a science teacher and a science library media specialist between Detroit's Northwestern High School and the David Adamany Undergraduate Library at Wayne State University to develop student information literacy in high school. Discusses activities; teacher attitudes; introduction of the Big6 Skills; and…

Long life high reliability thermal control systems study data handbook

NASA Technical Reports Server (NTRS)

Scollon, T. R., Jr.; Carpitella, M. J.

1971-01-01

The development of thermal control systems with high reliability and long service life is discussed. Various passive and semi-active thermal control systems which have been installed on space vehicles are described. The properties of the various coatings are presented in tabular form.

Antimicrobial Activity of ε-Poly-l-lysine after Forming a Water-Insoluble Complex with an Anionic Surfactant.

PubMed

Ushimaru, Kazunori; Hamano, Yoshimitsu; Katano, Hajime

2017-04-10

ε-Poly-l-lysine (ε-PL) is one of the few homopoly(amino-acid)s occurring in nature. ε-PL, which possesses multiple amino groups, is highly soluble in water, where it forms the antimicrobial polycationic chain (PL n+ ). Although the high water-solubility is advantageous for the use of ε-PL as a food preservative, it has limited the applicability of ε-PL as a biopolymer plastic. Here, we report on the preparation and availability of a water-insoluble complex formed with PL n+ and an anionic surfactant, bis(2-ethylhexyl) sulfosuccinate (BEHS - , is also commercialized as AOT) anion. The PL n+ /BEHS - -complex, which is soluble in organic solvents, was successfully used as a coating material for a cellulose acetate membrane to create a water-resistant antimicrobial membrane. In addition, the thermoplastic PL n+ /BEHS - -complex was able to be uniformly mixed with polypropylene by heating, resulting in materials exhibiting antimicrobial activities.

Orogenesis, high-T thermal events, and gold vein formation within metamorphic rocks of the Alaskan Cordillera

USGS Publications Warehouse

Goldfarb, R.J.; Snee, L.W.; Pickthorn, W.J.

1993-01-01

Mesothermal, gold-bearing quartz veins are widespread within allochthonous terranes of Alaska that are composed dominantly of greenschist-facies metasedimentary rocks. The most productive lode deposits are concentrated in south-central and southeastern Alaska; small and generally nonproductive gold-bearing veins occur upstream from major placer deposits in interior and northern Alaska. Ore-forming fluids in all areas are consistent with derivation from metamorphic devolatilisation reactions, and a close temporal relationship exists between high-T tectonic deformation, igneous activity, and gold mineralization. Ore fluids were of consistently low salinity, CO2-rich, and had ??18O values of 7 ???-12??? and ??D values between -15??? and -35???. Upper-crustal temperatures within the metamorphosed terranes reached at least 450-500??C before onset of significant gold-forming hydrothermal activity. In southern Alaska, gold deposits formed during latter stages of Tertiary, subduction-related, collisional orogenesis and were often temporally coeval with calc-alkaline magmatism. -from Authors

A comparison of treatment-seeking pathological gamblers based on preferred gambling activity.

PubMed

Petry, Nancy M

2003-05-01

To compare and contrast gamblers with different forms of problematic gambling activities. DESIGN, SETTING AND MEASUREMENTS: Pathological gamblers completed the Addiction Severity Index (ASI) and gambling questionnaires when initiating out-patient treatment. Participants (n = 347) were categorized by their most problematic form of gambling activity: sports, horse/dog-races, cards, slots and scratch/lottery tickets. Differences in demographics, gambling variables, and ASI composite scores were compared across groups. After controlling for demographic variables, the types of gamblers differed in severity of gambling, alcohol and psychiatric problems. Horse/dog-race gamblers were generally older, male and less educated; they began gambling regularly at a young age and spent relatively high amounts of money gambling. Sports gamblers were young males and had intermediary gambling problems; they had relatively high rates of current substance use but few psychiatric problems. Card players spent low to moderate amounts of time and money gambling, and they generally reported few alcohol problems and little psychiatric distress. Slot machine players were older and more likely to be female. Slot gamblers began gambling later in life, had high rates of bankruptcy and reported psychiatric difficulties. Scratch/lottery gamblers spent the least amount of money gambling, but they gambled the most frequently and had relatively severe alcohol and psychiatric symptoms. Gambling patterns and severity of psychosocial problems vary by form of problematic gambling, and these differences may influence treatment recommendations and outcomes.

Antibiofilm effect of poly(vinyl alcohol-co-ethylene) (PVA-co-PE) halamine film against Listeria innocua and Escherichia coli O157:H7.

PubMed

Cossu, Andrea; Si, Yang; Sun, Gang; Nitin, Nitin

2017-08-11

Bacterial biofilm formation is linked to several infections and foodborne disease outbreaks. To address this challenge, there is an unmet need to develop rechargeable antimicrobial materials that can provide continuous sanitation of contact surfaces especially in the food industry. This study was aimed at evaluating a novel rechargeable antimicrobial polymer formed using PVA-co-PE with halamine functionality to prevent biofilm formation with repeated exposure to high loads of bacteria and organic content and also aid in inactivation of pre-formed biofilms upon contact with this novel material. Antibiofilm activity of this rechargeable antimicrobial material was evaluated using a combination of fluorescence and scanning electron microscopies and biofilm metabolic activity analyses. The results based on imaging and metabolic activity measurements demonstrated that halamine functionalized polymer films significantly reduced L. innocua and E. coli O157:H7 biofilms formation. This novel polymeric material maintained its antibiofilm activity with repeated cycles of extended exposure to high levels of bacterial load. These polymeric films were recharged using bleach and cleaned using mechanical sonication after each cycle of extended incubation with bacteria. Halamine functionalized polymeric material also exhibited significant antibacterial activity against pre-formed biofilms on a model surface. In summary, results demonstrate potential of this antimicrobial material to provide continuous sanitation surfaces and applications for inactivating pre-formed biofilms without extensive use of resources including water and heat. This polymeric material may be used as a replacement for existing polymeric materials or used as a coating on diverse materials. IMPORTANCE Conventional sanitizers can have limited efficacy in inactivating biofilms in areas with limited accessibility and buildup of organic biomass. Furthermore, none of the current approaches provide continuous sanitation of surfaces. There is a significant unmet need to develop and validate materials that can prevent biofilm formation as well as inactivate pre-formed biofilms. In this study the efficacy of a copolymer film containing N-halamine against the biofilms of L. innocua and E. coli O157:H7 was evaluated. The polymer film showed a strong biofilm inhibitory activity against pre-grown biofilm or prevented the growth of a new biofilm. The polymer film also maintained its anti-biofilm activity revealed after multiple cycles of exposure to high titer of bacterial load with recharging of the polymer film using bleach at intermediate steps between the cycles. Overall, the results demonstrate potential of a novel antimicrobial material to inhibit and treat biofilms in food industry applications. Copyright © 2017 American Society for Microbiology.

Integrated structure vacuum tube

NASA Technical Reports Server (NTRS)

Dimeff, J.; Kerwin, W. J. (Inventor)

1976-01-01

High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

Longitudinal analysis of metalloproteinases, tissue inhibitors of metalloproteinases and clinical parameters in gingival crevicular fluid from periodontitis-affected patients.

PubMed

Pozo, P; Valenzuela, M A; Melej, C; Zaldívar, M; Puente, J; Martínez, B; Gamonal, J

2005-06-01

The aim of this work was to improve the assessment of the periodontal disease status through measurements of extracellular matrix metalloproteinases (MMPs) and their tissular inhibitors (TIMPs) in the gingival crevicular fluid from patients diagnosed with chronic periodontitis. Gingival crevicular fluid samples from patients (n = 13) were taken from 60 sites initially, and from 51 and 41 sites, respectively, 3 and 6 months after scaling and root planing. Gingival crevicular fluid samples were also taken from healthy subjects (n = 11, 24 sites). The presence of MMP-9 and MMP-8 was assessed by zymography and immunowestern blotting, respectively. The actual MMP activity (gelatinase and collagenase) was measured using the fluorogenic substrate assay. TIMP-1 and -2 levels were measured by immunodot blot. The fluorogenic substrate assay determinations showed higher MMP activity in sites with probing depth > or = 4 mm, with significant reduction post-treatment. Gelatinase activity followed by zymography consisted mainly of MMP-9. A different pattern of MMP-8 in control and patient sites was found. Controls only showed species of a partially active form (69 kDa), whereas patient sites showed a high frequency of the active form (56 kDa), and in some cases the latent form (85 kDa) was also observed. The active form reduced its frequency in sites with probing depth > or = 4 mm. TIMP-1 and -2 levels in patients were significantly lower than in controls, and after treatment the recovery of TIMP-1 level similar to control was observed. Significant correlations between the severity of the periodontal disease and the actual MMP activity, the active form of MMP-8 and the low level of both TIMP-1 and TIMP-2 were found.

Natural emulsifiers - Biosurfactants, phospholipids, biopolymers, and colloidal particles: Molecular and physicochemical basis of functional performance.

PubMed

McClements, David Julian; Gumus, Cansu Ekin

2016-08-01

There is increasing consumer pressure for commercial products that are more natural, sustainable, and environmentally friendly, including foods, cosmetics, detergents, and personal care products. Industry has responded by trying to identify natural alternatives to synthetic functional ingredients within these products. The focus of this review article is on the replacement of synthetic surfactants with natural emulsifiers, such as amphiphilic proteins, polysaccharides, biosurfactants, phospholipids, and bioparticles. In particular, the physicochemical basis of emulsion formation and stabilization by natural emulsifiers is discussed, and the benefits and limitations of different natural emulsifiers are compared. Surface-active polysaccharides typically have to be used at relatively high levels to produce small droplets, but the droplets formed are highly resistant to environmental changes. Conversely, surface-active proteins are typically utilized at low levels, but the droplets formed are highly sensitive to changes in pH, ionic strength, and temperature. Certain phospholipids are capable of producing small oil droplets during homogenization, but again the droplets formed are highly sensitive to changes in environmental conditions. Biosurfactants (saponins) can be utilized at low levels to form fine oil droplets that remain stable over a range of environmental conditions. Some nature-derived nanoparticles (e.g., cellulose, chitosan, and starch) are effective at stabilizing emulsions containing relatively large oil droplets. Future research is encouraged to identify, isolate, purify, and characterize new types of natural emulsifier, and to test their efficacy in food, cosmetic, detergent, personal care, and other products. Copyright © 2016 Elsevier B.V. All rights reserved.

Silicon-on-insulator (SOI) active pixel sensors with the photosite implemented in the substrate

NASA Technical Reports Server (NTRS)

Pain, Bedabrata (Inventor); Zheng, Xinyu (Inventor)

2002-01-01

Active pixel sensors for a high quality imager are fabricated using a silicon-on-insulator (SOI) process by integrating the photodetectors on the SOI substrate and forming pixel readout transistors on the SOI thin-film. The technique can include forming silicon islands on a buried insulator layer disposed on a silicon substrate and selectively etching away the buried insulator layer over a region of the substrate to define a photodetector area. Dopants of a first conductivity type are implanted to form a signal node in the photodetector area and to form simultaneously drain/source regions for a first transistor in at least a first one of the silicon islands. Dopants of a second conductivity type are implanted to form drain/source regions for a second transistor in at least a second one of the silicon islands. Isolation rings around the photodetector also can be formed when dopants of the second conductivity type are implanted. Interconnections among the transistors and the photodetector are provided to allow signals sensed by the photodetector to be read out via the transistors formed on the silicon islands.

Silicon-on-insulator (SOI) active pixel sensors with the photosite implemented in the substrate

NASA Technical Reports Server (NTRS)

Zheng, Xinyu (Inventor); Pain, Bedabrata (Inventor)

2005-01-01

Active pixel sensors for a high quality imager are fabricated using a silicon-on-insulator (SOI) process by integrating the photodetectors on the SOI substrate and forming pixel readout transistors on the SOI thin-film. The technique can include forming silicon islands on a buried insulator layer disposed on a silicon substrate and selectively etching away the buried insulator layer over a region of the substrate to define a photodetector area. Dopants of a first conductivity type are implanted to form a signal node in the photodetector area and to form simultaneously drain/source regions for a first transistor in at least a first one of the silicon islands. Dopants of a second conductivity type are implanted to form drain/source regions for a second transistor in at least a second one of the silicon islands. Isolation rings around the photodetector also can be formed when dopants of the second conductivity type are implanted. Interconnections among the transistors and the photodetector are provided to allow signals sensed by the photodetector to be read out via the transistors formed on the silicon islands.

Tandem SAM Domain Structure of Human Caskin1: A Presynaptic, Self-Assembling Scaffold for CASK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stafford, Ryan L.; Hinde, Elizabeth; Knight, Mary Jane

2012-02-07

The synaptic scaffolding proteins CASK and Caskin1 are part of the fibrous mesh of proteins that organize the active zones of neural synapses. CASK binds to a region of Caskin1 called the CASK interaction domain (CID). Adjacent to the CID, Caskin1 contains two tandem sterile a motif (SAM) domains. Many SAM domains form polymers so they are good candidates for forming the fibrous structures seen in the active zone. We show here that the SAM domains of Caskin1 form a new type of SAM helical polymer. The Caskin1 polymer interface exhibits a remarkable segregation of charged residues, resulting in amore » high sensitivity to ionic strength in vitro. The Caskin1 polymers can be decorated with CASK proteins, illustrating how these proteins may work together to organize the cytomatrix in active zones.« less

Dual activity of certain HIT-proteins: A. thaliana Hint4 and C. elegans DcpS act on adenosine 5'-phosphosulfate as hydrolases (forming AMP) and as phosphorylases (forming ADP).

PubMed

Guranowski, Andrzej; Wojdyła, Anna Maria; Zimny, Jarosław; Wypijewska, Anna; Kowalska, Joanna; Jemielity, Jacek; Davis, Richard E; Bieganowski, Paweł

2010-01-04

Histidine triad (HIT)-family proteins interact with different mono- and dinucleotides and catalyze their hydrolysis. During a study of the substrate specificity of seven HIT-family proteins, we have shown that each can act as a sulfohydrolase, catalyzing the liberation of AMP from adenosine 5'-phosphosulfate (APS or SO(4)-pA). However, in the presence of orthophosphate, Arabidopsis thaliana Hint4 and Caenorhabditis elegans DcpS also behaved as APS phosphorylases, forming ADP. Low pH promoted the phosphorolytic and high pH the hydrolytic activities. These proteins, and in particular Hint4, also catalyzed hydrolysis or phosphorolysis of some other adenylyl-derivatives but at lower rates than those for APS cleavage. A mechanism for these activities is proposed and the possible role of some HIT-proteins in APS metabolism is discussed.

Hanford's Simulated Low Activity Waste Cast Stone Processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young

2013-08-20

Cast Stone is undergoing evaluation as the supplemental treatment technology for Hanford’s (Washington) high activity waste (HAW) and low activity waste (LAW). This report will only cover the LAW Cast Stone. The programs used for this simulated Cast Stone were gradient density change, compressive strength, and salt waste form phase identification. Gradient density changes show a favorable outcome by showing uniformity even though it was hypothesized differently. Compressive strength exceeded the minimum strength required by Hanford and greater compressive strength increase seen between the uses of different salt solution The salt waste form phase is still an ongoing process asmore » this time and could not be concluded.« less

The Effects of Allium sativum Extracts on Biofilm Formation and Activities of Six Pathogenic Bacteria.

PubMed

Mohsenipour, Zeinab; Hassanshahian, Mehdi

2015-08-01

Garlic is considered a rich source of many compounds, which shows antimicrobial effects. The ability of microorganisms to adhere to both biotic and abiotic surfaces and to form biofilm is responsible for a number of diseases of chronic nature, demonstrating extremely high resistance to antibiotics. Bacterial biofilms are complex communities of sessile microorganisms, embedded in an extracellular matrix and irreversibly attached to various surfaces. The present study evaluated the antimicrobial activity of Allium sativum extract against the biofilms of six pathogenic bacteria and their free-living forms. The clinical isolates in this study had not been studied in any other studies, especially in regard to biofilm disruption and inhibition of biofilm cell metabolic activity. Antimicrobial activities of A. sativum L. extracts (methanol and ethanol extracts) against planktonic forms of bacteria were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were evaluated by a macrobroth dilution technique. The anti-biofilm effects were assessed by microtiter plate method. The results showed that the A. sativum L. extract discs did not have any zone of inhibition for the tested bacteria. However, The MIC values of A. sativum L. extracts (0.078 - 2.5 mg/mL) confirmed the high ability of these extracts for inhibition of planktonic bacteria. A. sativum L. extracts were efficient to inhibit biofilm structures and the concentration of each extract had a direct relation with the inhibitory effect. Finally, it can be suggested that the extracts of this plant be applied as antimicrobial agents against these pathogens, particularly in biofilm forms.

High purity silane and silicon production

NASA Technical Reports Server (NTRS)

Breneman, William C. (Inventor)

1987-01-01

Silicon tetrachloride, hydrogen and metallurgical silicon are reacted at about 400.degree.-600.degree. C. and at pressures in excess of 100 psi, and specifically from about 300 up to about 600 psi to form di- and trichlorosilane that is subjected to disproportionation in the presence of an anion exchange resin to form high purity silane. By-product and unreacted materials are recycled, with metallurgical silicon and hydrogen being essentially the only consumed feed materials. The silane product may be further purified, as by means of activated carbon or cryogenic distillation, and decomposed in a fluid bed or free space reactor to form high purity polycrystalline silicon and by-product hydrogen which can be recycled for further use. The process results in simplified waste disposal operations and enhances the overall conversion of metallurgical grade silicon to silane and high purity silicon for solar cell and semiconductor silicon applications.

Antimicrobial Treatment of Polymeric Medical Devices by Silver Nanomaterials and Related Technology.

PubMed

Polívková, Markéta; Hubáček, Tomáš; Staszek, Marek; Švorčík, Václav; Siegel, Jakub

2017-02-15

Antimicrobial biocompatible polymers form a group of highly desirable materials in medicinal technology that exhibit interesting thermal and mechanical properties, and high chemical resistance. There are numerous types of polymers with antimicrobial activity or antimicrobial properties conferred through their proper modification. In this review, we focus on the second type of polymers, especially those whose antimicrobial activity is conferred by nanotechnology. Nanotechnology processing is a developing area that exploits the antibacterial effects of broad-scale compounds, both organic and inorganic, to form value-added medical devices. This work gives an overview of nanostructured antimicrobial agents, especially silver ones, used together with biocompatible polymers as effective antimicrobial composites in healthcare. The bactericidal properties of non-conventional antimicrobial agents are compared with those of conventional ones and the advantages and disadvantages are discussed.

Fullerene C60 and graphene photosensibiles for photodynamic virus inactivation

NASA Astrophysics Data System (ADS)

Belousova, I.; Hvorostovsky, A.; Kiselev, V.; Zarubaev, V.; Kiselev, O.; Piotrovsky, L.; Anfimov, P.; Krisko, T.; Muraviova, T.; Rylkov, V.; Starodubzev, A.; Sirotkin, A.; Grishkanich, A.; Kudashev, I.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Afanasyev, M.; Lukyanov, N.; Redka, D.; Paklinov, N.

2018-02-01

A solid-phase photosensitizer based on aggregated C60 fullerene and graphene oxide for photodynamic inactivation of pathogens in biological fluids was studied. The most promising technologies of inactivation include the photodynamic effect, which consists in the inactivation of infectious agents by active oxygen forms (including singlet oxygen), formed when light is activated by the photosensitizer introduced into the plasma. Research shows features of solid-phase systems based on graphene and fullerene C60 oxide, which is a combination of an effective inactivating pathogens (for example, influenza viruses) reactive oxygen species formed upon irradiation of the photosensitizer in aqueous and biological fluids, a high photostability fullerene coatings and the possibility of full recovery photosensitizer from the biological environment after the photodynamic action.

Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

DOEpatents

Apel, C.T.; Layman, L.R.; Gallimore, D.L.

1988-05-10

A nebulizer is described for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets. 2 figs.

Candida virulence and ethanol-derived acetaldehyde production in oral cancer and non-cancer subjects.

PubMed

Alnuaimi, A D; Ramdzan, A N; Wiesenfeld, D; O'Brien-Simpson, N M; Kolev, S D; Reynolds, E C; McCullough, M J

2016-11-01

To compare biofilm-forming ability, hydrolytic enzymes and ethanol-derived acetaldehyde production of oral Candida isolated from the patients with oral cancer and matched non-oral cancer. Fungal biofilms were grown in RPMI-1640 medium, and biofilm mass and biofilm activity were assessed using crystal violet staining and XTT salt reduction assays, respectively. Phospholipase, proteinase, and esterase production were measured using agar plate method, while fungal acetaldehyde production was assessed via gas chromatography. Candida isolated from patients with oral cancer demonstrated significantly higher biofilm mass (P = 0.031), biofilm metabolic activity (P < 0.001), phospholipase (P = 0.002), and proteinase (P = 0.0159) activity than isolates from patients with non-oral cancer. High ethanol-derived acetaldehyde-producing Candida were more prevalent in patients with oral cancer than non-oral cancer (P = 0.01). In univariate regression analysis, high biofilm mass (P = 0.03) and biofilm metabolic activity (P < 0.001), high phospholipase (P = 0.003), and acetaldehyde production ability (0.01) were significant risk factors for oral cancer; while in the multivariate regression analysis, high biofilm activity (0.01) and phospholipase (P = 0.01) were significantly positive influencing factors on oral cancer. These data suggest a significant positive association between the ability of Candida isolates to form biofilms, to produce hydrolytic enzymes, and to metabolize alcohol to acetaldehyde with their ability to promote oral cancer development. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Flare activity and photospheric analysis of Proxima Centauri

NASA Astrophysics Data System (ADS)

Pavlenko, Y.; Suárez Mascareño, A.; Rebolo, R.; Lodieu, N.; Béjar, V. J. S.; González Hernández, J. I.

2017-10-01

Context. We present the analysis of emission lines in high-resolution optical spectra of the planet-host star Proxima Centauri (Proxima) classified as a M5.5V. Aims: We carry out a detailed analysis of the observed spectra to get a better understanding of the physical conditions of the atmosphere of this star. Methods: We identify the emission lines in a series of 147 high-resolution optical spectra of the star at different levels of activity and compare them with the synthetic spectra computed over a wide spectral range. Results: Our synthetic spectra computed with the PHOENIX 2900/5.0/0.0 model atmosphere fits the observed spectral energy distribution from optical to near-infrared quite well. However, modelling strong atomic lines in the blue spectrum (3900-4200 Å) requires implementing additional opacity. We show that high-temperature layers in Proxima Centauri consist of at least three emitting parts: a) a stellar chromosphere where numerous emission lines form; we suggest that some emission cores of strong absorption lines of metals form there; b) flare regions above the chromosphere, where hydrogen Balmer lines up to high transition levels (10-2) form; and c) a stellar wind component with Vr = -30 km s-1 seen in some Balmer lines as blueshifted emission lines. We believe that the observed He line at 4026 Å in emission can be formed in that very hot region. Conclusions: We show that the real structure of the atmosphere of Proxima is rather complicated. The photosphere of the star is best fit by a normal M5 dwarf spectrum. On the other hand, emission lines form in the chromosphere, flare regions, and extended hot envelope. The movies are available at http://www.aanda.org

Air cathode structure manufacture

DOEpatents

Momyer, William R.; Littauer, Ernest L.

1985-01-01

An improved air cathode structure for use in primary batteries and the like. The cathode structure includes a matrix active layer, a current collector grid on one face of the matrix active layer, and a porous, nonelectrically conductive separator on the opposite face of the matrix active layer, the collector grid and separator being permanently bonded to the matrix active layer. The separator has a preselected porosity providing low IR losses and high resistance to air flow through the matrix active layer to maintain high bubble pressure during operation of the battery. In the illustrated embodiment, the separator was formed of porous polypropylene. A thin hydrophobic film is provided, in the preferred embodiment, on the current collecting metal grid.

Redox Modification of Cysteine Residues Regulates the Cytokine Activity of High Mobility Group Box-1 (HMGB1)

PubMed Central

Yang, Huan; Lundbäck, Peter; Ottosson, Lars; Erlandsson-Harris, Helena; Venereau, Emilie; Bianchi, Marco E; Al-Abed, Yousef; Andersson, Ulf; Tracey, Kevin J; Antoine, Daniel J

2012-01-01

High mobility group box 1 (HMGB1) is a nuclear protein with extracellular inflammatory cytokine activity. It is released passively during cell injury and necrosis, and secreted actively by immune cells. HMGB1 contains three conserved redox-sensitive cysteine residues: C23 and C45 can form an intramolecular disulfide bond, whereas C106 is unpaired and is essential for the interaction with Toll-Like Receptor (TLR) 4. However, a comprehensive characterization of the dynamic redox states of each cysteine residue and of their impacts on innate immune responses is lacking. Using tandem mass spectrometric analysis, we now have established that the C106 thiol and the C23–C45 disulfide bond are required for HMGB1 to induce nuclear NF-κB translocation and tumor necrosis factor (TNF) production in macrophages. Both irreversible oxidation to sulphonates and complete reduction to thiols of these cysteines inhibited TNF production markedly. In a proof of concept murine model of hepatic necrosis induced by acetaminophen, during inflammation, the predominant form of serum HMGB1 is the active one, containing a C106 thiol group and a disulfide bond between C23 and C45, whereas the inactive form of HMGB1, containing terminally oxidized cysteines, accumulates during inflammation resolution and hepatic regeneration. These results reveal critical posttranslational redox mechanisms that control the proinflammatory activity of HMGB1 and its inactivation during pathogenesis. PMID:22105604

Local analogues of high-redshift star-forming galaxies: integral field spectroscopy of green peas

NASA Astrophysics Data System (ADS)

Lofthouse, E. K.; Houghton, R. C. W.; Kaviraj, S.

2017-10-01

We use integral field spectroscopy, from the SWIFT and PALM3K instruments, to perform a spatially resolved spectroscopic analysis of four nearby highly star-forming 'green pea' (GP) galaxies, that are likely analogues of high-redshift star-forming systems. By studying emission-line maps in H α, [N II] λλ6548,6584 and [S II] λλ6716,6731, we explore the kinematic morphology of these systems and constrain properties such as gas-phase metallicities, electron densities and gas-ionization mechanisms. Two of our GPs are rotationally supported while the others are dispersion-dominated systems. The rotationally supported galaxies both show evidence for recent or ongoing mergers. However, given that these systems have intact discs, these interactions are likely to have low-mass ratios (I.e. minor mergers), suggesting that the minor-merger process may be partly responsible for the high star formation rates seen in these GPs. Nevertheless, the fact that the other two GPs appear morphologically undisturbed suggests that mergers (including minor mergers) are not necessary for driving the high star formation rates in such galaxies. We show that the GPs are metal-poor systems (25-40 per cent of solar) and that the gas ionization is not driven by active galactic nuclei (AGN) in any of our systems, indicating that the AGN activity is not coeval with star formation in these starbursting galaxies.

A Designed Angiopoietin-1 Variant, Dimeric CMP-Ang1 Activates Tie2 and Stimulates Angiogenesis and Vascular Stabilization in N-glycan Dependent Manner

PubMed Central

Oh, Nuri; Kim, Kangsan; Jin Kim, Soo; Park, Intae; Lee, Jung-Eun; Suk Seo, Young; Joo An, Hyun; Min Kim, Ho; Young Koh, Gou

2015-01-01

Angiopoietin-1 (Ang1), a potential growth factor for therapeutic angiogenesis and vascular stabilization, is known to specifically cluster and activate Tie2 in high oligomeric forms, which is a unique and essential process in this ligand-receptor interaction. However, highly oligomeric native Ang1 and Ang1 variants are difficult to produce, purify, and store in a stable and active form. To overcome these limitations, we developed a simple and active dimeric CMP-Ang1 by replacing the N-terminal of native Ang1 with the coiled-coil domain of cartilage matrix protein (CMP) bearing mutations in its cysteine residues. This dimeric CMP-Ang1 effectively increased the migration, survival, and tube formation of endothelial cells via Tie2 activation. Furthermore, dimeric CMP-Ang1 induced angiogenesis and suppressed vascular leakage in vivo. Despite its dimeric structure, the potencies of such Tie2-activation-induced effects were comparable to those of a previously engineered protein, COMP-Ang1. We also revealed that these effects of dimeric CMP-Ang1 were affected by specified N-glycosylation in its fibrinogen-like domain. Taken together, our results indicate that dimeric CMP-Ang1 is capable of activating Tie2 and stimulating angiogenesis in N-glycan dependent manner. PMID:26478188

Purification and ATPase activity of human ABCA1.

PubMed

Takahashi, Kei; Kimura, Yasuhisa; Kioka, Noriyuki; Matsuo, Michinori; Ueda, Kazumitsu

2006-04-21

ATP-binding cassette protein A1 (ABCA1) plays a major role in cholesterol homeostasis and high density lipoprotein metabolism. Apolipoprotein A-I binds to ABCA1 and cellular cholesterol and phospholipids, mainly phosphatidylcholine, are loaded onto apoA-I to form pre-beta high density lipoprotein (HDL). It is proposed that ABCA1 translocates phospholipids and cholesterol directly or indirectly to form pre-beta HDL. To explore the mechanism of ABCA1-mediated pre-beta HDL formation, we expressed human ABCA1 in insect Sf9 cells and purified it. Trypsin limited-digestion of purified ABCA1 in the detergent-soluble form suggested that it retained conformation similar to ABCA1 expressed in the membranes of human fibroblast WI-38 cells. Purified ABCA1 showed robust ATPase activity when reconstituted in liposomes made of synthetic phosphatidylcholine. ABCA1 showed lower ATPase activity when reconstituted in liposomes containing phosphatidylserine, phosphatidylethanolamine, or phosphatidylglycerol and also showed weak specificity in acyl chain species. ATPase activity was reduced by the addition of cholesterol and decreased by 25% in the presence of 20% cholesterol. Beta-sitosterol and campesterol showed similar inhibitory effects but stigmasterol did not, suggesting structure-specific interaction between ABCA1 and sterols. Glibenclamide suppressed ABCA1 ATPase, suggesting that it inhibits apoA-I-dependent cellular cholesterol efflux by suppressing ABCA1 ATPase activity. These results suggest that the ATPase activity of ABCA1 is stimulated preferentially by phospholipids with choline head groups, phosphatidylcholine and sphingomyelin. This study with purified human ABCA1 provides the first biochemical basis of the mechanism for HDL formation mediated by ABCA1.

LaFe 0.9Ni 0.1O 3 perovskite catalyst with enhanced activity and coke-resistance for dry reforming of ethane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Baohuai; Yan, Binhang; Yao, Siyu

In this work, a LaFe 0.9Ni 0.1O 3 perovskite catalyst was evaluated for dry reforming of ethane (DRE), with two conventional oxide supported Ni catalysts (Ni/La 2O 3 and NiFe/La 2O 3) being used as references. LaFe 0.9Ni 0.1O 3 showed the best activity and high coke-/sintering-resistance. TEM, TGA, and Raman characterizations confirmed that the deactivation of Ni/La 2O 3 was owing to the growth of Ni particles and the accumulation of coke, although the formation of La 2O 2CO 3 was able to remove part of the coke during the reaction. The introduction of Fe-related species inhibited the cokemore » formation while decreased the activity due to the loss of active sites. A portion of Ni ions in the perovskite lattice could be reduced to form highly dispersed and stable Ni nanoparticles on the surface during the reaction and oxygen vacancies were left in the perovskite lattice. Pulse reactor studies revealed that the oxygen vacancies in the perovskite could facilitate the activation and dissociation of CO 2 to form CO and reactive oxygen species. Additionally, C 2H 6 was activated with the assistance of oxygen from the surface or subsurface of LaFe 0.9Ni 0.1O 3 to form CO, rather than directly dissociated to surface carbon species as observed over Ni/La 2O 3.« less

LaFe 0.9Ni 0.1O 3 perovskite catalyst with enhanced activity and coke-resistance for dry reforming of ethane

DOE PAGES

Zhao, Baohuai; Yan, Binhang; Yao, Siyu; ...

2017-12-29

In this work, a LaFe 0.9Ni 0.1O 3 perovskite catalyst was evaluated for dry reforming of ethane (DRE), with two conventional oxide supported Ni catalysts (Ni/La 2O 3 and NiFe/La 2O 3) being used as references. LaFe 0.9Ni 0.1O 3 showed the best activity and high coke-/sintering-resistance. TEM, TGA, and Raman characterizations confirmed that the deactivation of Ni/La 2O 3 was owing to the growth of Ni particles and the accumulation of coke, although the formation of La 2O 2CO 3 was able to remove part of the coke during the reaction. The introduction of Fe-related species inhibited the cokemore » formation while decreased the activity due to the loss of active sites. A portion of Ni ions in the perovskite lattice could be reduced to form highly dispersed and stable Ni nanoparticles on the surface during the reaction and oxygen vacancies were left in the perovskite lattice. Pulse reactor studies revealed that the oxygen vacancies in the perovskite could facilitate the activation and dissociation of CO 2 to form CO and reactive oxygen species. Additionally, C 2H 6 was activated with the assistance of oxygen from the surface or subsurface of LaFe 0.9Ni 0.1O 3 to form CO, rather than directly dissociated to surface carbon species as observed over Ni/La 2O 3.« less

Dynamic Behavior of Microbubbles during Long Ultrasound Tone-Burst Excitation: Mechanistic Insights into Ultrasound-Microbubble Mediated Therapeutics Using High-Speed Imaging and Cavitation Detection.

PubMed

Chen, Xucai; Wang, Jianjun; Pacella, John J; Villanueva, Flordeliza S

2016-02-01

Ultrasound (US)-microbubble (MB)-mediated therapies have been found to restore perfusion and enhance drug/gene delivery. On the presumption that MBs do not persist during long US exposure under high acoustic pressures, most schemes use short US pulses when a high US pressure is employed. However, we recently observed an enhanced thrombolytic effect using long US pulses at high acoustic pressures. Therefore, we explored the fate of MBs during long tone-burst exposures (5 ms) at various acoustic pressures and MB concentrations via direct high-speed optical observation and passive cavitation detection. MBs first underwent stable or inertial cavitation depending on the acoustic pressure and then formed gas-filled clusters that continued to oscillate, break up and form new clusters. Cavitation detection confirmed continued, albeit diminishing, acoustic activity throughout the 5-ms US excitation. These data suggest that persisting cavitation activity during long tone bursts may confer additional therapeutic effects. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Bradykinin-forming components in Kuwaiti patients with type 2 diabetes.

PubMed

Sharma, J N; Al-Shoumer, K A S; Matar, K M; Al-Gharee, H Y; Madathil, N V

2013-01-01

Diabetes is the most common risk factor in inducing hypertension, nephropathy and retinopathy. The bradykinin (BK)-forming system has been proposed to protect cardiovascular and renal functions. We therefore evaluated urinary active and proactive kallikrein, total kininogen, plasma tissue kallikrein, plasma creatinine, plasma glucose and plasma HbA1c in newly diagnosed untreated type 2 diabetic patients and healthy subjects. In diabetic patients, urinary and plasma tissue kallikrein concentrations were significantly increased. In addition, plasma prekallikrein levels were also significantly higher. However, urinary kininogen values were significantly reduced in diabetic patients when compared with healthy subjects. This is the first investigation among Kuwaiti Arab patients with type 2 diabetes showing abnormal activities in the BK-forming system. High levels of plasma prekallikrein may be a risk factor for developing high blood pressure as well as nephropathy. The urinary and plasma tissue kallikrein concentrations were higher in diabetic patients, which could indicate the hyperactivities of these components, and may result in increased levels of plasma glucose to induce diabetes. Furthermore, the urinary kininogen levels were reduced in diabetic patients. These alterations might reflect the utilization of urinary kininogen to form BK, a potent inflammatory agent. However, this hypothesis needs further investigation.

Effects of bacteriocins on methicillin-resistant Staphylococcus aureus biofilm.

PubMed

Okuda, Ken-ichi; Zendo, Takeshi; Sugimoto, Shinya; Iwase, Tadayuki; Tajima, Akiko; Yamada, Satomi; Sonomoto, Kenji; Mizunoe, Yoshimitsu

2013-11-01

Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections.

Effects of Bacteriocins on Methicillin-Resistant Staphylococcus aureus Biofilm

PubMed Central

Zendo, Takeshi; Sugimoto, Shinya; Iwase, Tadayuki; Tajima, Akiko; Yamada, Satomi; Sonomoto, Kenji

2013-01-01

Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections. PMID:23979748

Advanced fire-resistant forms of activated carbon and methods of adsorbing and separating gases using same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Yongliang; Wang, Yifeng

A method of removing a target gas from a gas stream is disclosed. The method uses advanced, fire-resistant activated carbon compositions having vastly improved fire resistance. Methods for synthesizing the compositions are also provided. The advanced compositions have high gas adsorption capacities and rapid adsorption kinetics (comparable to commercially-available activated carbon), without having any intrinsic fire hazard.

Criterion-Related Validity of the Short Form of the International Physical Activity Questionnaire in Adults Who Are Blind

ERIC Educational Resources Information Center

Marmeleira, Jose; Laranjo, Luis; Marques, Olga; Batalha, Nuno

2013-01-01

This article describes the results of a recommendation from the World Health Organization (2004) that it was important to examine whether high-risk groups meet the current general recommendation of at least 30 minutes of moderate or greater physical activity per day. Doing so required an accurate measurement of physical activity for supporting the…

Selective Targeting of High-Affinity LFA-1 Does Not Augment Costimulation Blockade in a Nonhuman Primate Renal Transplantation Model.

PubMed

Samy, K P; Anderson, D J; Lo, D J; Mulvihill, M S; Song, M; Farris, A B; Parker, B S; MacDonald, A L; Lu, C; Springer, T A; Kachlany, S C; Reimann, K A; How, T; Leopardi, F V; Franke, K S; Williams, K D; Collins, B H; Kirk, A D

2017-05-01

Costimulation blockade (CoB) via belatacept is a lower-morbidity alternative to calcineurin inhibitor (CNI)-based immunosuppression. However, it has higher rates of early acute rejection. These early rejections are mediated in part by memory T cells, which have reduced dependence on the pathway targeted by belatacept and increased adhesion molecule expression. One such molecule is leukocyte function antigen (LFA)-1. LFA-1 exists in two forms: a commonly expressed, low-affinity form and a transient, high-affinity form, expressed only during activation. We have shown that antibodies reactive with LFA-1 regardless of its configuration are effective in eliminating memory T cells but at the cost of impaired protective immunity. Here we test two novel agents, leukotoxin A and AL-579, each of which targets the high-affinity form of LFA-1, to determine whether this more precise targeting prevents belatacept-resistant rejection. Despite evidence of ex vivo and in vivo ligand-specific activity, neither agent when combined with belatacept proved superior to belatacept monotherapy. Leukotoxin A approached a ceiling of toxicity before efficacy, while AL-579 failed to significantly alter the peripheral immune response. These data, and prior studies, suggest that LFA-1 blockade may not be a suitable adjuvant agent for CoB-resistant rejection. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Constitutively active mutants of the alpha 1B-adrenergic receptor: role of highly conserved polar amino acids in receptor activation.

PubMed Central

Scheer, A; Fanelli, F; Costa, T; De Benedetti, P G; Cotecchia, S

1996-01-01

Site-directed mutagenesis and molecular dynamics simulations of the alpha 1B-adrenergic receptor (AR) were combined to explore the potential molecular changes correlated with the transition from R (inactive state) to R (active state). Using molecular dynamics analysis we compared the structural/dynamic features of constitutively active mutants with those of the wild type and of an inactive alpha 1B-AR to build a theoretical model which defines the essential features of R and R. The results of site-directed mutagenesis were in striking agreement with the predictions of the model supporting the following hypothesis. (i) The equilibrium between R and R depends on the equilibrium between the deprotonated and protonated forms, respectively, of D142 of the DRY motif. In fact, replacement of D142 with alanine confers high constitutive activity to the alpha 1B-AR. (ii) The shift of R143 of the DRY sequence out of a conserved 'polar pocket' formed by N63, D91, N344 and Y348 is a feature common to all the active structures, suggesting that the role of R143 is fundamental for mediating receptor activation. Disruption of these intramolecular interactions by replacing N63 with alanine constitutively activates the alpha 1B-AR. Our findings might provide interesting generalities about the activation process of G protein-coupled receptors. Images PMID:8670860

Final Technical/Scientific Report: Commodity Scale Thermostable Enzymatic Transformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

James J. Lalonde; Brian Davison

2003-08-30

The conversion of corn starch to high fructose corn-syrup sweetener is a commodity process, producing over 3 billion kg/y. In the last step of the process, an enzyme catalyst is used to convert glucose to the much sweeter sugar fructose. Due to incomplete conversion in the last step, the syrup must be purified using a chromatographic separation technique, which results in equal quantities of water being added to the syrup, and finally the water must be evaporated (up to 1 lb of water/lb of syrup). We have estimated the energy requirement in the evaporation step to be on the ordermore » of 13 billion BTU's/y. This process inefficiency could be eliminated if a thermostable form of glucose isomerase (GI), the enzyme catalyst used in the final step, was developed. Our chosen strategy was to develop an immobilized form of the enzyme in which the protein is first crystallized and then chemically cross-linked to form an insoluble particle. This so-called cross-linked enzyme crystal (CLE C(reg. sign)) technology had been shown to be a powerful method for enzyme stabilization for several other protein catalysts. In this work we have developed more than 30 CLEC preparations of glucose isomerase and tested them for activity and stability. We found these preparations to be highly active, with a 10-50 fold rate per gram of catalyst increase over existing commercial catalysts. The initial rates were also higher at higher temperatures as expected, however the efficiency of the CLEC GI preparations unexpectedly rapidly decreased to a low constant value with use at the higher temperatures. At this point, the source of this activity loss is unclear, however during this loss, the catalyst is found to form a solid mass indicating either breakage of the chemical cross-links or simple aggregation of the particles. It is likely that the increased mass transfer resistance due to this agglomeration is a major component of the activity loss. This research suggests that one potentially beneficial outcome could be the reconfiguration of catalyst columns using these highly active catalyst preparations with inerts to prevent agglomeration. As a result of this work, methods for the preparation of highly active immobilized glucose isomerase preparations were developed along with test methods that are predictive for the stability of these preparations. This research has been conducted as a team effort. The enzyme is produced using Genencor's glucose isomerase protein and the stabilized form has been prepared using Altus' CLEC technology. ORNL has provided bioprocess engineering and testing expertise, and Cargill, Inc. and Genencor have supplied critical technical consultation and economic assessment.« less

Development of active CFRP/metal laminates and their demonstrations in complicated forms

NASA Astrophysics Data System (ADS)

Asanuma, H.; Nakata, T.; Tanaka, T.; Imori, M.; Haga, O.

2006-03-01

This paper describes development of high performance CFRP/metal active laminates and demonstrations of them in complicated forms. Various types of the laminates were made by hot-pressing of an aluminum, aluminum alloys, a stainless steel and a titanium for the metal layer as a high CTE material, a unidirectional CFRP prepreg as a low CTE/electric resistance heating material, a unidirectional KFRP prepreg as a low CTE/insulating material. The aluminum and its alloy type laminates have almost the same and the highest room temperature curvatures and they linearly change with increasing temperature up to their fabrication temperature. The curvature of the stainless steel type jumps from one to another around its fabrication temperature, whereas the titanium type causes a double curvature and its change becomes complicated. The output force of the stainless steel type attains the highest of the three under the same thickness. The aluminum type successfully increased its output force by increasing its thickness and using its alloys. The electric resistance of the CFRP layer can be used to monitor the temperature, that is, the curvature of the active laminate because the curvature is a function of temperature. The aluminum type active laminate was made into complicated forms, that is, a hatch, a stack, a coil and a lift types, and their actuation performances were successfully demonstrated.

Native aggregation as a cause of origin of temporary cellular structures needed for all forms of cellular activity, signaling and transformations.

PubMed

Matveev, Vladimir V

2010-06-09

According to the hypothesis explored in this paper, native aggregation is genetically controlled (programmed) reversible aggregation that occurs when interacting proteins form new temporary structures through highly specific interactions. It is assumed that Anfinsen's dogma may be extended to protein aggregation: composition and amino acid sequence determine not only the secondary and tertiary structure of single protein, but also the structure of protein aggregates (associates). Cell function is considered as a transition between two states (two states model), the resting state and state of activity (this applies to the cell as a whole and to its individual structures). In the resting state, the key proteins are found in the following inactive forms: natively unfolded and globular. When the cell is activated, secondary structures appear in natively unfolded proteins (including unfolded regions in other proteins), and globular proteins begin to melt and their secondary structures become available for interaction with the secondary structures of other proteins. These temporary secondary structures provide a means for highly specific interactions between proteins. As a result, native aggregation creates temporary structures necessary for cell activity."One of the principal objects of theoretical research in any department of knowledge is to find the point of view from which the subject appears in its greatest simplicity."Josiah Willard Gibbs (1839-1903).

Five of 12 forms of vaccinia virus-expressed human hepatic cytochrome P450 metabolically activate aflatoxin B sub 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoyama, Toshifumi; Yamano, Shigeru; Gelboin, H.V.

Twelve forms of human hepatic cytochrome P450 were expressed in hepatoma cells by means of recombinant vaccinia viruses. The expressed P450s were analyzed for their abilities to activate the potent hepatocarcinogen aflatoxin B{sub 1} to metabolites having mutagenic or DNA-binding properties. Five forms, P450s IA2, IIA3, IIB7, IIIA3, and IIIA4, activated aflatoxin B{sub 1} to mutagenic metabolites as assessed by the production of His revertants of Salmonella typhimurium in the Ames test. The same P450s catalyzed conversion of aflatoxin B{sub 1} to DNA-bound derivatives as judged by an in situ assay in which the radiolabeled carcinogen was incubated with cellsmore » expressing the individual P450 forms. Seven other human P450s, IIC8, IIC9, IID6, IIE1, IIF1, and IIIA5, and IVB1, did not significantly activate aflatoxin B{sub 1} as measured by both the Ames test and the DNA-binding assay. Moreover, polyclonal anti-rat liver P450 antibodies that crossreact with individual human P450s IA2, IIA3, IIIA3, and IIIA4 each inhibited aflatoxin B{sub 1} activation catalyzed by human liver S-9 extracts. Inhibition ranged from as low as 10% with antibody against IIA3 to as high as 65% with antibody against IIIA3 and IIIA4. These results establish that metabolic activation of aflatoxin B{sub 1} in human liver involves the contribution of multiple forms of P450.« less

Occupational Exploration at Ontario Junior High School: 7th Grade.

ERIC Educational Resources Information Center

Bates, Gene; And Others

The document contains 47 activities for Grade 7. The contents include the following areas: vocabulary; a large variety of inventory and other forms focusing especially on self awareness, self evaluation, and value clarification; a 44-page unit guide for a course called Know Yourself, which includes objectives, activities, evaluation, and…

Highly active thermally stable nanoporous gold catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biener, Juergen; Wittstock, Arne; Biener, Monika M.

In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

Visual Journaling: Engaging Adolescents in Sketchbook Activities

ERIC Educational Resources Information Center

Cummings, Karen L.

2011-01-01

A wonderful way to engage high-school students in sketchbook activities is to have them create journals that combine images with words to convey emotions, ideas, and understandings. Visual journaling is a creative way for them to share their experiences and personal responses to life's events in visual and written form. Through selecting and…

ACTIVATION OF A CRYPTIC D-SERINE DEAMINASE (DSD) GENE FROM PSEUDOMONAS CEPACIA 17616

EPA Science Inventory

D-serine inhibits growth of P. cepacia 17616; however, resistant mutants able to express an ordinarily cryptic D-serine deaminase (dsd) gene were isolated readily. The resistant strains formed high levels of a D-serine deaminase active on D-threonine as well as D-serine. IS eleme...

Morphological modification of alpha-MnO2 catalyst for use in Li/air batteries.

PubMed

Park, Min-Sik; Kim, Jae-Hun; Kim, Ki Jae; Jeong, Goojin; Kim, Young-Jun

2013-05-01

Single crystal alpha-MnO2 nanowires and nanopowders have been successfully synthesized in order to facilitate a comparison of their catalytic activity for use in Li-air batteries. The importance of the morphological modification of the alpha-MnO2 catalyst for facilitating electrochemical reactions between Li and O2 is addressed. Distinctive catalytic activity of alpha-MnO2 is observed, which is in line with its different morphologies. The catalytic activity significantly affects the reversible capacity of Li-air batteries. A high aspect ratio, large surface area and good dispersibility of alpha-MnO2 in the nanowire form are advantageous providing larger active surfaces for promoting the fundamental reactions in Li-air batteries. We also introduce a robustly designed air-electrode composed of highly porous carbon and nanostructured alpha-MnO2 catalysts, with employs a metal foam current collector to ensure sufficient air-permeability and to maximize electronic conduction during cycles. Our suggestions should prove helpful in forming a basis for further investigations in developing advanced Li-air batteries.

Trypanocidal and leishmanicidal activities of different antimicrobial peptides (AMPs) isolated from aquatic animals.

PubMed

Löfgren, S E; Miletti, L C; Steindel, M; Bachère, E; Barracco, M A

2008-02-01

Most of the available animal antimicrobial peptides (AMPs) have been tested against bacteria and fungi, but very few against protozoan parasites. In the present study, we investigated the antiparasitic activity of different AMPs isolated from aquatic animals: tachyplesin (Tach, from Tachypleus tridentatus), magainin (Mag, from Xenopus laevis), clavanin (Clav, from Styela clava), penaeidin (Pen, from Litopenaeus vannamei), mytilin (Myt, from Mytilus edulis) and anti-lipopolysaccharide factor (ALF, from Penaeus monodon). The antiparasitic activity was evaluated against the promastigote form of Leishmania braziliensis and epi and trypomastigote forms of Trypanosoma cruzi, through the MTT method. Tach was the most potent peptide, killing completely L. braziliensis and trypomastigote T. cruzi from 12.5microM, whereas Pen and Clav were weakly active against trypomastigotes and Myt against L. braziliensis, only at a high concentration (100microM). Tach and Mag were markedly hemolytic at high concentrations, whereas the other peptides caused only a slight hemolysis (<10% up to 50microM). Our results point to Tach as the only potential candidate for further investigation and potential application as a therapeutic agent.

A Novel RNase 3/ECP Peptide for Pseudomonas aeruginosa Biofilm Eradication That Combines Antimicrobial, Lipopolysaccharide Binding, and Cell-Agglutinating Activities

PubMed Central

Prats-Ejarque, Guillem; Villalba, Clara; Albacar, Marcel; González-López, Juan J.; Torrent, Marc; Moussaoui, Mohammed

2016-01-01

Eradication of established biofilm communities of pathogenic Gram-negative species is one of the pending challenges for the development of new antimicrobial agents. In particular, Pseudomonas aeruginosa is one of the main dreaded nosocomial species, with a tendency to form organized microbial communities that offer an enhanced resistance to conventional antibiotics. We describe here an engineered antimicrobial peptide (AMP) which combines bactericidal activity with a high bacterial cell agglutination and lipopolysaccharide (LPS) affinity. The RN3(5-17P22-36) peptide is a 30-mer derived from the eosinophil cationic protein (ECP), a host defense RNase secreted by eosinophils upon infection, with a wide spectrum of antipathogen activity. The protein displays high biofilm eradication activity that is not dependent on its RNase catalytic activity, as evaluated by using an active site-defective mutant. On the other hand, the peptide encompasses both the LPS-binding and aggregation-prone regions from the parental protein, which provide the appropriate structural features for the peptide's attachment to the bacterial exopolysaccharide layer and further improved removal of established biofilms. Moreover, the peptide's high cationicity and amphipathicity promote the cell membrane destabilization action. The results are also compared side by side with other reported AMPs effective against either planktonic and/or biofilm forms of Pseudomonas aeruginosa strain PAO1. The ECP and its derived peptide are unique in combining high bactericidal potency and cell agglutination activity, achieving effective biofilm eradication at a low micromolar range. We conclude that the designed RN3(5-17P22-36) peptide is a promising lead candidate against Gram-negative biofilms. PMID:27527084

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as its genome does not have homologs to the genes for phosphate acetyltransferase and acetate kinase. Here, we show thatS. aciditrophicususes an alternative approach, an AMP-forming, acetyl-CoA synthetase, to make ATP from acetyl-CoA. AMP-forming, acetyl-CoA synthetases were previously thought to function only in the activation of acetate to acetyl-CoA.« less

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE PAGES

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.; ...

2016-08-16

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as its genome does not have homologs to the genes for phosphate acetyltransferase and acetate kinase. Here, we show thatS. aciditrophicususes an alternative approach, an AMP-forming, acetyl-CoA synthetase, to make ATP from acetyl-CoA. AMP-forming, acetyl-CoA synthetases were previously thought to function only in the activation of acetate to acetyl-CoA.« less

Reliability of Three Benton Judgment of Line Orientation Short Forms in Idiopathic Parkinson’s Disease

PubMed Central

Gullett, Joseph M.; Price, Catherine C.; Nguyen, Peter; Okun, Michael S.; Bauer, Russell M.; Bowers, Dawn

2013-01-01

Individuals with Parkinson’s disease (PD) often exhibit deficits in visuospatial functioning throughout the course of their disease. These deficits should be carefully assessed as they may have implications for patient safety and disease severity. One of the most commonly administered tests of visuospatial ability, the Benton Judgment of Line Orientation (JLO), consists of 30 pairs of lines requiring the patient to match the orientation of two lines to an array of 11 lines on a separate page. Reliable short forms have been constructed out of the full JLO form, but the reliability of these forms in PD has yet to be examined. Recent functional MRI studies examining the JLO demonstrate right parietal and occipital activation, as well as bilateral frontal activation and PD is known to adversely affect these pathways. We compared the reliability of the original full form to three unique short forms in a sample of 141 non-demented, idiopathic PD patients and 56 age and education matched controls. Results indicated that a two-thirds length short form can be used with high reliability and classification accuracy in patients with idiopathic PD. The other short forms performed in a similar, though slightly less reliable manner. PMID:23957375

The proximal part of the giant submarine Wailau landslide, Molokai, Hawaii

USGS Publications Warehouse

Clague, D.A.; Moore, J.G.

2002-01-01

The main break-in-slope on the northern submarine flank of Molokai at -1500 to -1250 m is a shoreline feature that has been only modestly modified by the Wailau landslide. Submarine canyons above the break-in-slope, including one meandering stream, were subaerially carved. Where such canyons cross the break-in-slope, plunge pools may form by erosion from bedload sediment carried down the canyons. West Molokai Volcano continued infrequent volcanic activity that formed a series of small coastal sea cliffs, now submerged, as the island subsided. Lavas exposed at the break-in-slope are subaerially erupted and emplaced tholeiitic shield lavas. Submarine rejuvenated-stage volcanic cones formed after the landslide took place and following at least 400-500 m of subsidence after the main break-in-slope had formed. The sea cliff on east Molokai is not the headwall of the landslide, nor did it form entirely by erosion. It may mark the location of a listric fault similar to the Hilina faults on present-day Kilauea Volcano. The Wailau landslide occurred about 1.5 Ma and the Kalaupapa Peninsula most likely formed 330??5 ka. Molokai is presently stable relative to sea level and has subsided no more than 30 m in the last 330 ka. At their peak, West and East Molokai stood 1.6 and 3 km above sea level. High rainfall causes high surface runoff and formation of canyons, and increases groundwater pressure that during dike intrusions may lead to flank failure. Active shield or postshield volcanism (with dikes injected along rift zones) and high rainfall appear to be two components needed to trigger the deep-seated giant Hawaiian landslides. ?? 2002 Elsevier Science B.V. All rights reserved.

Lon Protease of Azorhizobium caulinodans ORS571 Is Required for Suppression of reb Gene Expression

PubMed Central

Nakajima, Azusa; Tsukada, Shuhei; Siarot, Lowela; Ogawa, Tetsuhiro; Oyaizu, Hiroshi

2012-01-01

Bacterial Lon proteases play important roles in a variety of biological processes in addition to housekeeping functions. In this study, we focused on the Lon protease of Azorhizobium caulinodans, which can fix nitrogen both during free-living growth and in stem nodules of the legume Sesbania rostrata. The nitrogen fixation activity of an A. caulinodans lon mutant in the free-living state was not significantly different from that of the wild-type strain. However, the stem nodules formed by the lon mutant showed little or no nitrogen fixation activity. By microscopic analyses, two kinds of host cells were observed in the stem nodules formed by the lon mutant. One type has shrunken host cells containing a high density of bacteria, and the other type has oval or elongated host cells containing a low density or no bacteria. This phenotype is similar to a praR mutant highly expressing the reb genes. Quantitative reverse transcription-PCR analyses revealed that reb genes were also highly expressed in the lon mutant. Furthermore, a lon reb double mutant formed stem nodules showing higher nitrogen fixation activity than the lon mutant, and shrunken host cells were not observed in these stem nodules. These results suggest that Lon protease is required to suppress the expression of the reb genes and that high expression of reb genes in part causes aberrance in the A. caulinodans-S. rostrata symbiosis. In addition to the suppression of reb genes, it was found that Lon protease was involved in the regulation of exopolysaccharide production and autoagglutination of bacterial cells. PMID:22752172

Monolithic integrated high-T.sub.c superconductor-semiconductor structure

NASA Technical Reports Server (NTRS)

Barfknecht, Andrew T. (Inventor); Garcia, Graham A. (Inventor); Russell, Stephen D. (Inventor); Burns, Michael J. (Inventor); de la Houssaye, Paul R. (Inventor); Clayton, Stanley R. (Inventor)

2000-01-01

A method for the fabrication of active semiconductor and high-temperature superconducting device of the same substrate to form a monolithically integrated semiconductor-superconductor (MISS) structure is disclosed. A common insulating substrate, preferably sapphire or yttria-stabilized zirconia, is used for deposition of semiconductor and high-temperature superconductor substructures. Both substructures are capable of operation at a common temperature of at least 77 K. The separate semiconductor and superconductive regions may be electrically interconnected by normal metals, refractory metal silicides, or superconductors. Circuits and devices formed in the resulting MISS structures display operating characteristics which are equivalent to those of circuits and devices prepared on separate substrates.

Surface-enhanced raman spectroscopy substrate for arsenic sensing in groundwater

DOEpatents

Yang, Peidong; Mulvihill, Martin; Tao, Andrea R.; Sinsermsuksakul, Prasert; Arnold, John

2015-06-16

A surface-enhanced Raman spectroscopy (SERS) substrate formed from a plurality of monolayers of polyhedral silver nanocrystals, wherein at least one of the monolayers has polyvinypyrrolidone (PVP) on its surface, and thereby configured for sensing arsenic is described. Highly active SERS substrates are formed by assembling high density monolayers of differently shaped silver nanocrystals onto a solid support. SERS detection is performed directly on this substrate by placing a droplet of the analyte solution onto the nanocrystal monolayer. Adsorbed polymer, polyvinypyrrolidone (PVP), on the surface of the nanoparticles facilitates the binding of both arsenate and arsenite near the silver surface, allowing for highly accurate and sensitive detection capabilities.

Hydrolysis of model cellulose films by cellulosomes: Extension of quartz crystal microbalance techniques to multienzymatic complexes

USDA-ARS?s Scientific Manuscript database

Clostridium thermocellum, a well-studied cellulolytic bacterium, produces highly active cellulases in the form of cellulosomes. The ability of the cellulose binding module within the cellulosome to adhere C. thermocellum cells to the cellulosic substrate is considered to contribute to its high cellu...

75 FR 17368 - Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-06

..., mechanical, or other technological collection techniques or other forms of information technology. Comments...., Washington, DC 20250- 1522. FAX: (202) 720-8435. Title: Assistance to High Energy Cost Rural Communities. OMB... 2000 to create a new program to help rural communities with extremely high energy costs (Pub. L. 106...

Dehydrated DNA in B-form: ionic liquids in rescue

PubMed Central

Ghoshdastidar, Debostuti; Senapati, Sanjib

2018-01-01

Abstract The functional B-conformation of DNA succumbs to the A-form at low water activity. Methods for room temperature DNA storage that rely upon ‘anhydrobiosis’, thus, often encounter the loss of DNA activity due to the B→A-DNA transition. Here, we show that ionic liquids, an emerging class of green solvents, can induce conformational transitions in DNA and even rescue the dehydrated DNA in the functional B-form. CD spectroscopic analyses not only reveal rapid transition of A-DNA in 78% ethanol medium to B-conformation in presence of ILs, but also the high resistance of IL-bound B-form to transit to A-DNA under dehydration. Molecular dynamics simulations show the unique ability of ILs to disrupt Na+ ion condensation and form ‘IL spine’ in DNA minor groove to drive the A→B transition. Implications of these findings range from the plausible use of ILs as novel anhydrobiotic DNA storage medium to a switch for modulating DNA conformational transitions. PMID:29669113

Metal Complexes and Free Radical Toxins Produced by Pfiesteria piscicida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moeller,P.; Beauchesne, K.; Huncik, K.

2007-01-01

Metal-containing organic toxins produced by Pfiesteria piscicida were characterized, for the first time, by corroborating data obtained from five distinct instrumental methods: nuclear magnetic resonance spectroscopy (NMR), inductively coupled plasma mass spectrometry (ICP-MS), liquid chromatography particle beam glow discharge mass spectrometry (LC/PB-GDMS), electron paramagnetic resonance spectroscopy (EPR), and X-ray absorption spectroscopy (XAS). The high toxicity of the metal-containing toxins is due to metal-mediated free radical production. This mode of activity explains the toxicity of Pfiesteria, as well as previously reported difficulty in observing the molecular target, due to the ephemeral nature of radical species. The toxins are highly labile inmore » purified form, maintaining activity for only 2-5 days before all activity is lost. The multiple toxin congeners in active extracts are also susceptible to decomposition in the presence of white light, pH variations, and prolonged heat. These findings represent the first formal isolation and characterization of a radical forming toxic organic-ligated metal complex isolated from estuarine/marine dinoflagellates. These findings add to an increased understanding regarding the active role of metals interacting with biological systems in the estuarine environment, as well as their links and implications to human health.« less

Metal Complexes And Free Radical Toxins Produced By Pfiesteria Piscicida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moeller, P.D.R.; Beauchesne, K.R.; Huncik, K.M.

2009-06-03

Metal-containing organic toxins produced by Pfiesteria piscicida were characterized, for the first time, by corroborating data obtained from five distinct instrumental methods: nuclear magnetic resonance spectroscopy (NMR), inductively coupled plasma mass spectrometry (ICPMS), liquid chromatography particle beam glow discharge mass spectrometry (LC/PB-GDMS), electron paramagnetic resonance spectroscopy (EPR), and X-ray absorption spectroscopy (XAS). The high toxicity of the metal-containing toxins is due to metal-mediated free radical production. This mode of activity explains the toxicity of Pfiesteria, as well as previously reported difficulty in observing the molecular target, due to the ephemeral nature of radical species. The toxins are highly labile inmore » purified form, maintaining activity for only 2-5 days before all activity is lost. The multiple toxin congeners in active extracts are also susceptible to decomposition in the presence of white light, pH variations, and prolonged heat. These findings represent the first formal isolation and characterization of a radical forming toxic organic-ligated metal complex isolated from estuarine/marine dinoflagellates. These findings add to an increased understanding regarding the active role of metals interacting with biological systems in the estuarine environment, as well as their links and implications to human health.« less

Magnetic stimulation of the dorsolateral prefrontal cortex dissociates fragile visual short-term memory from visual working memory.

PubMed

Sligte, Ilja G; Wokke, Martijn E; Tesselaar, Johannes P; Scholte, H Steven; Lamme, Victor A F

2011-05-01

To guide our behavior in successful ways, we often need to rely on information that is no longer in view, but maintained in visual short-term memory (VSTM). While VSTM is usually broken down into iconic memory (brief and high-capacity store) and visual working memory (sustained, yet limited-capacity store), recent studies have suggested the existence of an additional and intermediate form of VSTM that depends on activity in extrastriate cortex. In previous work, we have shown that this fragile form of VSTM can be dissociated from iconic memory. In the present study, we provide evidence that fragile VSTM is different from visual working memory as magnetic stimulation of the right dorsolateral prefrontal cortex (DLPFC) disrupts visual working memory, while leaving fragile VSTM intact. In addition, we observed that people with high DLPFC activity had superior working memory capacity compared to people with low DLPFC activity, and only people with high DLPFC activity really showed a reduction in working memory capacity in response to magnetic stimulation. Altogether, this study shows that VSTM consists of three stages that have clearly different characteristics and rely on different neural structures. On the methodological side, we show that it is possible to predict individual susceptibility to magnetic stimulation based on functional MRI activity. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Solid-support immobilization of a "swing" fusion protein for enhanced glucose oxidase catalytic activity.

PubMed

Takatsuji, Yoshiyuki; Yamasaki, Ryota; Iwanaga, Atsushi; Lienemann, Michael; Linder, Markus B; Haruyama, Tetsuya

2013-12-01

The strategic surface immobilization of a protein can add new functionality to a solid substrate; however, protein activity, e.g., enzymatic activity, can be drastically decreased on immobilization onto a solid surface. The concept of a designed and optimized "molecular interface" is herein introduced in order to address this problem. In this study, molecular interface was designed and constructed with the aim of attaining high enzymatic activity of a solid-surface-immobilized a using the hydrophobin HFBI protein in conjunction with a fusion protein of HFBI attached to glucose oxidase (GOx). The ability of HFBI to form a self-organized membrane on a solid surface in addition to its adhesion properties makes it an ideal candidate for immobilization. The developed fusion protein was also able to form an organized membrane, and its structure and immobilized state on a solid surface were investigated using QCM-D measurements. This method of immobilization showed retention of high enzymatic activity and the ability to control the density of the immobilized enzyme. In this study, we demonstrated the importance of the design and construction of molecular interface for numerous purposes. This method of protein immobilization could be utilized for preparation of high throughput products requiring structurally ordered molecular interfaces, in addition to many other applications. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

An investigation of the practice activities and coaching behaviors of professional top-level youth soccer coaches.

PubMed

Partington, M; Cushion, C

2013-06-01

The aim of this study was to investigate the coaching behaviors of elite English youth soccer coaches in different practice settings and gain insight into the coaches' cognitive processes underpinning these behaviors. The practice setting was split into two types of activities, "training form" and "playing form," and behavioral data were collected using a modified version of the Coach Analysis and Intervention System. Interpretive interview data were triangulated with the behavioral data to ensure that both the "what" and the "why" of the coaches' behavior and practice were considered. The results showed the coaches using more "training form" activities than "playing form," and using high levels of prescriptive instruction, regardless of practice type, in contrast to a stated desire to "developing the whole player," creating "decision makers," and being a "facilitator of knowledge creation." The interviews revealed that the coaches had a low self-awareness about their behavior, with an epistemological gap identified between understanding and practice, with statements of intent not being matched by knowledge and action. © 2011 John Wiley & Sons A/S.

Successful control of Epstein-Barr virus (EBV)-infected cells by allogeneic nonmyeloablative stem cell transplantation in a patient with the lethal form of chronic active EBV infection.

PubMed

Uehara, Taeko; Nakaseko, Chiaki; Hara, Satoru; Harima, Akane; Ejiri, Megumi; Yokota, Akira; Saito, Yasushi; Nishimura, Miki

2004-08-01

Chronic active Epstein-Barr virus infection (CAEBV) is a heterogeneous EBV-related disorder, ranging from mild/moderate forms to rapidly lethal disorders. The lethal form of CAEBV is characterized by multiple organ failure, hemophagocytic syndrome, and development of lymphomas. Allogeneic stem cell transplantation is considered as the only potentially curative treatment for the lethal form of CAEBV, but it is not always desirable because of the high incidence of regimen-related toxicities. A 17-year-old female with CAEBV, who was refractory to conventional therapies and considered to be unable to receive a myeloablative regimen because of multiple organ dysfunction, underwent allogeneic nonmyeloablative stem cell transplantation (allo-NST) before developing a hematological malignancy. She has been well without any signs of CAEBV for 27 months after allo-NST, and we confirmed that specific cytotoxic T lymphocyte activity against EBV was reconstituted. This outcome suggests that allo-NST can control CAEBV by reconstituting the host immunity against EBV. Copyright 2004 Wiley-Liss, Inc.

Reflection of the State of Hunger in Impulse Activity of Nose Wing Muscles and Upper Esophageal Sphincter during Search behavior in Rabbits.

PubMed

Kromin, A A; Dvoenko, E E; Zenina, O Yu

2016-07-01

Reflection of the state of hunger in impulse activity of nose wing muscles and upper esophageal sphincter muscles was studied in chronic experiments on rabbits subjected to 24-h food deprivation in the absence of locomotion and during search behavior. In the absence of apparent behavioral activity, including sniffing, alai nasi muscles of hungry rabbits constantly generated bursts of action potentials synchronous with breathing, while upper esophageal sphincter muscles exhibited regular aperiodic low-amplitude impulse activity of tonic type. Latent form of food motivation was reflected in the structure of temporal organization of impulse activity of alai nasi muscles in the form of bimodal distribution of interpulse intervals and in temporal structure of impulse activity of upper esophageal sphincter muscles in the form of monomodal distribution. The latent form of food motivation was manifested in the structure of temporal organization of periods of the action potentials burst-like rhythm, generated by alai nasi muscles, in the form of monomodal distribution, characterized by a high degree of dispersion of respiratory cycle periods. In the absence of physical activity hungry animals sporadically exhibited sniffing activity, manifested in the change from the burst-like impulse activity of alai nasi muscles to the single-burst activity type with bimodal distribution of interpulse intervals and monomodal distribution of the burst-like action potentials rhythm periods, the maximum of which was shifted towards lower values, which was the cause of increased respiratory rate. At the same time, the monomodal temporal structure of impulse activity of the upper esophageal sphincter muscles was not changed. With increasing food motivation in the process of search behavior temporal structure of periods of the burst-like action potentials rhythm, generated by alai nasi muscles, became similar to that observed during sniffing, not accompanied by animal's locomotion, which is typical for the increased respiratory rhythm frequency. Increased hunger motivation was reflected in the temporal structure of impulse activity of upper esophageal sphincter muscles in the form of a shift to lower values of the maximum of monomodal distribution of interpulse intervals on the histogram, resulting in higher impulse activity frequency. The simultaneous increase in the frequency of action potentials bursts generation by alai nasi muscles and regular impulse activity of upper esophageal sphincter muscles is a reliable criterion for enhanced food motivation during search behavior in rabbits.

High levels of the soluble form of CD30 molecule in rheumatoid arthritis (RA) are expression of CD30+ T cell involvement in the inflamed joints.

PubMed Central

Gerli, R; Muscat, C; Bistoni, O; Falini, B; Tomassini, C; Agea, E; Tognellini, R; Biagini, P; Bertotto, A

1995-01-01

The CD30 is a surface molecule expressed by Th2-type lymphokine-producing T cells upon activation. CD30-expressing activated T cells release a soluble form of the molecule, which can be detectable both in vitro and in vivo. In the present study, high levels of soluble CD30 were found in peripheral blood and synovial fluid from patients with RA. However, CD30+ CD3+ cells, either CD4+ or CD8+, were significantly present in synovial fluid, but not in peripheral blood, of RA patients. Serum values of soluble CD30 were higher in active than inactive RA patients and directly correlated with rheumatoid factor serum titres. These data strongly support an involvement of CD30+ T cells in the immune processes of rheumatoid synovitis, and may suggest a relationship between Th2-type cytokine-secreting T cells and the pathological response in RA. PMID:8536371

Sterol-recognition ability and membrane-disrupting activity of Ornithogalum saponin OSW-1 and usual 3-O-glycosyl saponins.

PubMed

Malabed, Raymond; Hanashima, Shinya; Murata, Michio; Sakurai, Kaori

2017-12-01

OSW-1 is a structurally unique steroidal saponin isolated from the bulbs of Ornithogalum saundersiae, and has exhibited highly potent and selective cytotoxicity in tumor cell lines. This study aimed to investigate the molecular mechanism for the membrane-permeabilizing activity of OSW-1 in comparison with those of other saponins by using various spectroscopic approaches. The membrane effects and hemolytic activity of OSW-1 were markedly enhanced in the presence of membrane cholesterol. Binding affinity measurements using fluorescent cholestatrienol and solid-state NMR spectroscopy of a 3-d-cholesterol probe suggested that OSW-1 interacts with membrane cholesterol without forming large aggregates while 3-O-glycosyl saponin, digitonin, forms cholesterol-containing aggregates. The results suggest that OSW-1/cholesterol interaction is likely to cause membrane permeabilization and pore formation without destroying the whole membrane integrity, which could partly be responsible for its highly potent cell toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

High energy phosphate transfer by NDPK B/Gbetagammacomplexes--an alternative signaling pathway involved in the regulation of basal cAMP production.

PubMed

Hippe, Hans-Joerg; Wieland, Thomas

2006-08-01

The activation of heterotrimeric G proteins induced by G protein coupled receptors (GPCR) is generally believed to occur by a GDP/GTP exchange at the G protein alpha -subunit. Nevertheless, nucleoside diphosphate kinase (NDPK) and the beta-subunit of G proteins (Gbeta) participate in G protein activation by phosphate transfer reactions leading to the formation of GTP from GDP. Recent work elucidated the role of these reactions. Apparently, the NDPK isoform B (NDPK B) forms a complex with Gbetagamma dimers in which NDPK B acts as a histidine kinase phosphorylating Gbeta at His266. Out of this high energetic phosphoamidate bond the phosphate can be transferred specifically onto GDP. The formed GTP binds to the G protein alpha-subunit and thus activates the respective G protein. Evidence is presented, that this process occurs independent of the classical GPCR-induced GTP/GTP exchange und thus contributes, e.g. to the regulation of basal cAMP synthesis in cells.

Neural congruence between intertemporal and interpersonal self-control: Evidence from delay and social discounting.

PubMed

Hill, Paul F; Yi, Richard; Spreng, R Nathan; Diana, Rachel A

2017-11-15

Behavioral studies using delay and social discounting as indices of self-control and altruism, respectively, have revealed functional similarities between farsighted and social decisions. However, neural evidence for this functional link is lacking. Twenty-five young adults completed a delay and social discounting task during fMRI scanning. A spatiotemporal partial least squares analysis revealed that both forms of discounting were well characterized by a pattern of brain activity in areas comprising frontoparietal control, default, and mesolimbic reward networks. Both forms of discounting appear to draw on common neurocognitive mechanisms, regardless of whether choices involve intertemporal or interpersonal outcomes. We also observed neural profiles differentiating between high and low discounters. High discounters were well characterized by increased medial temporal lobe and limbic activity. In contrast, low discount rates were associated with activity in the medial prefrontal cortex and right temporoparietal junction. This pattern may reflect biological mechanisms underlying behavioral heterogeneity in discount rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Solution structures and backbone dynamics of Escherichia coli rhodanese PspE in its sulfur-free and persulfide-intermediate forms: implications for the catalytic mechanism of rhodanese.

PubMed

Li, Hongwei; Yang, Fan; Kang, Xue; Xia, Bin; Jin, Changwen

2008-04-15

Rhodanese catalyzes the sulfur-transfer reaction that transfers sulfur from thiosulfate to cyanide by a double-displacement mechanism, in which an active cysteine residue plays a central role. Previous studies indicated that the phage-shock protein E (PspE) from Escherichia coli is a rhodanese composed of a single active domain and is the only accessible rhodanese among the three single-domain rhodaneses in E. coli. To understand the catalytic mechanism of rhodanese at the molecular level, we determined the solution structures of the sulfur-free and persulfide-intermediate forms of PspE by nuclear magnetic resonance (NMR) spectroscopy and identified the active site by NMR titration experiments. To obtain further insights into the catalytic mechanism, we studied backbone dynamics by NMR relaxation experiments. Our results demonstrated that the overall structures in both sulfur-free and persulfide-intermediate forms are highly similar, suggesting that no significant conformational changes occurred during the catalytic reaction. However, the backbone dynamics revealed that the motional properties of PspE in its sulfur-free form are different from the persulfide-intermediate state. The conformational exchanges are largely enhanced in the persulfide-intermediate form of PspE, especially around the active site. The present structural and biochemical studies in combination with backbone dynamics provide further insights in understanding the catalytic mechanism of rhodanese.

Cocrystal dissociation in the presence of water: a general approach for identifying stable cocrystal forms.

PubMed

Eddleston, Mark D; Madusanka, Nadeesh; Jones, William

2014-09-01

In previous studies, cocrystals have been shown to be susceptible to dissociation at high humidity because of differences in the solubilities of the two coformer molecules, especially when these molecules can form hydrates. Contrastingly, however, the propensity of the pharmaceutically active compound caffeine to hydrate formation is reduced by cocrystallization with oxalic acid. Here, the stability of the oxalic acid cocrystal of caffeine is investigated from a thermodynamic perspective through the use of aqueous slurries of caffeine hydrate and oxalic acid dihydrate. Conversion to the anhydrous caffeine-oxalic acid cocrystal occurred under these conditions confirming that this form is thermodynamically stable in an aqueous environment. The slurry methodology was further developed as a general approach to screening for cocrystals that are not susceptible to dissociation at high humidity. In this manner, cocrystals of the hydrate-forming molecules theophylline, carbamazepine, and piroxicam that are stable at high humidity, indefinitely avoiding hydrate formation, were identified. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Structural characterization of a non-heme iron active site in zeolites that hydroxylates methane

DOE PAGES

Snyder, Benjamin E. R.; Bottger, Lars H.; Bols, Max L.; ...

2018-04-02

Iron-containing zeolites exhibit unprecedented reactivity in the low-temperature hydroxylation of methane to form methanol. Reactivity occurs at a mononuclear ferrous active site, α-Fe(II), that is activated by N 2O to form the reactive intermediate α-O. This has been defined as an Fe(IV)=O species. Using nuclear resonance vibrational spectroscopy coupled to X-ray absorption spectroscopy, we probe the bonding interaction between the iron center, its zeolite lattice-derived ligands, and the reactive oxygen. α-O is found to contain an unusually strong Fe(IV)=O bond resulting from a constrained coordination geometry enforced by the zeolite lattice. As a result, density functional theory calculations clarify howmore » the experimentally determined geometric structure of the active site leads to an electronic structure that is highly activated to perform H-atom abstraction.« less

Structural characterization of a non-heme iron active site in zeolites that hydroxylates methane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snyder, Benjamin E. R.; Bottger, Lars H.; Bols, Max L.

Iron-containing zeolites exhibit unprecedented reactivity in the low-temperature hydroxylation of methane to form methanol. Reactivity occurs at a mononuclear ferrous active site, α-Fe(II), that is activated by N 2O to form the reactive intermediate α-O. This has been defined as an Fe(IV)=O species. Using nuclear resonance vibrational spectroscopy coupled to X-ray absorption spectroscopy, we probe the bonding interaction between the iron center, its zeolite lattice-derived ligands, and the reactive oxygen. α-O is found to contain an unusually strong Fe(IV)=O bond resulting from a constrained coordination geometry enforced by the zeolite lattice. As a result, density functional theory calculations clarify howmore » the experimentally determined geometric structure of the active site leads to an electronic structure that is highly activated to perform H-atom abstraction.« less

Revisiting the mechanism of coagulation factor XIII activation and regulation from a structure/functional perspective

PubMed Central

Gupta, Sneha; Biswas, Arijit; Akhter, Mohammad Suhail; Krettler, Christoph; Reinhart, Christoph; Dodt, Johannes; Reuter, Andreas; Philippou, Helen; Ivaskevicius, Vytautas; Oldenburg, Johannes

2016-01-01

The activation and regulation of coagulation Factor XIII (FXIII) protein has been the subject of active research for the past three decades. Although discrete evidence exists on various aspects of FXIII activation and regulation a combinatorial structure/functional view in this regard is lacking. In this study, we present results of a structure/function study of the functional chain of events for FXIII. Our study shows how subtle chronological submolecular changes within calcium binding sites can bring about the detailed transformation of the zymogenic FXIII to its activated form especially in the context of FXIIIA and FXIIIB subunit interactions. We demonstrate what aspects of FXIII are important for the stabilization (first calcium binding site) of its zymogenic form and the possible modes of deactivation (thrombin mediated secondary cleavage) of the activated form. Our study for the first time provides a structural outlook of the FXIIIA2B2 heterotetramer assembly, its association and dissociation. The FXIIIB subunits regulatory role in the overall process has also been elaborated upon. In summary, this study provides detailed structural insight into the mechanisms of FXIII activation and regulation that can be used as a template for the development of future highly specific therapeutic inhibitors targeting FXIII in pathological conditions like thrombosis. PMID:27453290

Increased brain lysosomal pepstatin-insensitive proteinase activity in patients with neurodegenerative diseases.

PubMed

Junaid, M A; Pullarkat, R K

1999-04-02

A recent study has shown mutations in CLN2 gene, that encodes a novel lysosomal pepstatin-insensitive proteinase (LPIP), in the pathophysiology of late-infantile neuronal ceroid lipofuscinosis (LINCL). We have measured the LPIP activities in brains from various forms of human neuronal ceroid lipofuscinoses (NCL), canine ceroid lipofuscinosis and other neurodegenerative disorders with a highly sensitive assay using a tetrapeptide Gly-Phe-Phe-Leu-amino-trifluoromethyl coumarin (AFC) as substrate. Brain LPIP has a pH optimum of 3.5 and an apparent km of 100 microM for the crude enzyme. The enzyme activity is totally absent in LINCL patients. Pronounced increase in the LPIP activity was seen in patients suffering from infantile (INCL), juvenile (JNCL) and adult (ANCL) forms of neuronal ceroid lipofuscinoses. LPIP activity was also found to be increased about two-fold in Alzheimer's disease when compared with normal or age-matched controls, while in globoidal-cell leukodystrophy (Krabbe's disease) it was similar to the normal controls. Although mannose-6-phosphorylated LPIP is increased 13-fold in brains of patients with JNCL, this form of LPIP did not have any enzyme activity. The mechanism by which LPIP activities are increased in a wide range of neurodegenerative diseases is unknown, although neuronal loss, followed by gliosis are common characteristics of these diseases.

Physical Activity and Alcohol Use Disorders

PubMed Central

Lisha, Nadra E.; Sussman, Steve; FAPA, FAAHB; Leventhal, Adam M.

2013-01-01

Background Prior research has documented a counterintuitive positive association between physical activity and indices of alcohol consumption frequency and heaviness. Objectives To investigate whether this relation extends to alcohol use disorder and clarify whether this association is non-linear. Methods This is a cross-sectional, correlational population-based study of US adults (N = 34,653). The Alcohol Use Disorder and Associated Disabilities Interview Schedule was used to classify past-year DSM-IV alcohol use disorder and self-reported federal government-recommended weekly physical activity cutoffs. Results After statistically controlling for confounds, alcohol abuse but not dependence was associated with greater prevalence of physical activity. Number of alcohol use disorder symptoms exhibited a curvilinear relationship with meeting physical activity requirements, such that the positive association degraded with high symptom counts. Conclusion There is a positive association between physical activity and less severe forms of alcohol use disorder in US adults. More severe forms of alcohol use disorder are not associated with physical activity. PMID:22992050

Physical Activity of Male and Female Adolescents Living in a Town and a City in the Context of Public Health Recommendations

ERIC Educational Resources Information Center

Mynarski, Wladyslaw; Nawrocka, Agnieszka; Rozpara, Michal; Garbaciak, Wieslaw

2012-01-01

Study aim: To assess the physical activity of male and female adolescents from Poland living in a town (Czechowice-Dziedzice) and in a city (Katowice). Material and methods: The research involved 431 high school students aged 16-18 years (249 from Czechowice-Dziedzice and 182 from Katowice). Physical activity was measured by the short form of the…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvucci, Michael

Research examined the thermal stability and propensity for aggregation of wild type and the C- and N-terminally modified forms of activase to determine if loss of activity under heat stress is dependent on protein aggregation. The results showed that 1) loss of activity at high temperature is independent of aggregation; 2) activase with both C- and N-terminal S-Tags are more susceptible to aggregation than wild type activase, 3) aggregation is highly dependent on the concentration of Mg2+ and 4) the ATP analog, ATPgammaS, protects against both thermal inactivation and aggregation.

GDF3 is a BMP inhibitor that can activate Nodal signaling only at very high doses

PubMed Central

Levine, Ariel J.; Levine, Zachary J.; Brivanlou, Ali H.

2013-01-01

Within the TGF-β superfamily, there are approximately forty ligands divided into two major branches: the TGF-β/Activin/Nodal ligands and the BMP/GDF ligands. We studied the ligand GDF3 and found that it inhibits signaling by its co-family members, the BMPs; however, GDF3 has been described by others to have Nodal-like activity. Here, we show that GDF3 can activate Nodal signaling, but only at very high doses and only upon mRNA over-expression. In contrast, GDF3 inhibits BMP signaling upon over-expression of GDF3 mRNA, as recombinant protein, and regardless of its dose. We therefore further characterized the mechanism through which GDF3 protein acts as a specific BMP inhibitor and found that the BMP inhibitory activity of GDF3 resides redundantly in the unprocessed, predominant form and in the mature form of the protein. These results confirm and extend the activity that we described for GDF3 and illuminate the experimental basis for the different observations of others. We suggest that GDF3 is either a bi-functional TGF-β ligand, or, more likely, that it is a BMP inhibitor that can artificially activate Nodal signaling under non-physiological conditions. PMID:18823971

Resolution of the diadenosine 5',5"'-P1,P4-tetraphosphate binding subunit from a multiprotein form of HeLa cell DNA polymerase alpha.

PubMed Central

Baril, E; Bonin, P; Burstein, D; Mara, K; Zamecnik, P

1983-01-01

A diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) binding subunit has been resolved from a high molecular weight (640,000) multiprotein form of DNA polymerase alpha [deoxynucleoside triphosphate:DNA nucleotidyltransferase (DNA-directed), EC 2.7.7.7] from HeLa cells [DNA polymerase alpha 2 of Lamothe, P., Baril, B., Chi, A., Lee, L. & Baril, E. (1981) Proc. Natl. Acad. Sci. USA 78, 4723-4727]. The Ap4A binding activity copurifies with the DNA polymerizing activity during the course of purification. Hydrophobic chromatography on butylagarose resolves the Ap4A binding activity from the DNA polymerase. The Ap4A binding activity is protein in nature since the binding of Ap4A is abolished by treatment of the isolated binding activity with proteinase K but is insensitive to treatment with DNase or RNase. The molecular weight of the Ap4A binding protein, as determined by polyacrylamide gel electrophoresis under nondenaturing conditions or by NaDodSO4/polyacrylamide gel electrophoresis after photoaffinity labeling of the protein with [32P]Ap4A is 92,000 or 47,000. The binding activity of this protein is highly specific for Ap4A. Images PMID:6576366

Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

DOEpatents

Sen, Ayusman; Jiang, Zhaozhong

1996-01-01

The compound, [Pd(Me-DUPHOS)(MeCN).sub.2 ](BF.sub.4).sub.2, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic .alpha.-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone)

Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

DOEpatents

Sen, A.; Jiang, Z.

1996-05-28

The compound, [Pd(Me-DUPHOS)(MeCN){sub 2}](BF{sub 4}){sub 2}, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic {alpha}-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone).

Antimicrobial Treatment of Polymeric Medical Devices by Silver Nanomaterials and Related Technology

PubMed Central

Polívková, Markéta; Hubáček, Tomáš; Staszek, Marek; Švorčík, Václav; Siegel, Jakub

2017-01-01

Antimicrobial biocompatible polymers form a group of highly desirable materials in medicinal technology that exhibit interesting thermal and mechanical properties, and high chemical resistance. There are numerous types of polymers with antimicrobial activity or antimicrobial properties conferred through their proper modification. In this review, we focus on the second type of polymers, especially those whose antimicrobial activity is conferred by nanotechnology. Nanotechnology processing is a developing area that exploits the antibacterial effects of broad-scale compounds, both organic and inorganic, to form value-added medical devices. This work gives an overview of nanostructured antimicrobial agents, especially silver ones, used together with biocompatible polymers as effective antimicrobial composites in healthcare. The bactericidal properties of non-conventional antimicrobial agents are compared with those of conventional ones and the advantages and disadvantages are discussed. PMID:28212308

Identifying the Evolutionary Building Blocks of the Cardiac Conduction System

PubMed Central

Jensen, Bjarke; Boukens, Bastiaan J. D.; Postma, Alex V.; Gunst, Quinn D.; van den Hoff, Maurice J. B.; Moorman, Antoon F. M.; Wang, Tobias; Christoffels, Vincent M.

2012-01-01

The endothermic state of mammals and birds requires high heart rates to accommodate the high rates of oxygen consumption. These high heart rates are driven by very similar conduction systems consisting of an atrioventricular node that slows the electrical impulse and a His-Purkinje system that efficiently activates the ventricular chambers. While ectothermic vertebrates have similar contraction patterns, they do not possess anatomical evidence for a conduction system. This lack amongst extant ectotherms is surprising because mammals and birds evolved independently from reptile-like ancestors. Using conserved genetic markers, we found that the conduction system design of lizard (Anolis carolinensis and A. sagrei), frog (Xenopus laevis) and zebrafish (Danio rerio) adults is strikingly similar to that of embryos of mammals (mouse Mus musculus, and man) and chicken (Gallus gallus). Thus, in ectothermic adults, the slow conducting atrioventricular canal muscle is present, no fibrous insulating plane is formed, and the spongy ventricle serves the dual purpose of conduction and contraction. Optical mapping showed base-to-apex activation of the ventricles of the ectothermic animals, similar to the activation pattern of mammalian and avian embryonic ventricles and to the His-Purkinje systems of the formed hearts. Mammalian and avian ventricles uniquely develop thick compact walls and septum and, hence, form a discrete ventricular conduction system from the embryonic spongy ventricle. Our study uncovers the evolutionary building plan of heart and indicates that the building blocks of the conduction system of adult ectothermic vertebrates and embryos of endotherms are similar. PMID:22984480

Loop Electrostatics Asymmetry Modulates the Preexisting Conformational Equilibrium in Thrombin.

PubMed

Pozzi, Nicola; Zerbetto, Mirco; Acquasaliente, Laura; Tescari, Simone; Frezzato, Diego; Polimeno, Antonino; Gohara, David W; Di Cera, Enrico; De Filippis, Vincenzo

2016-07-19

Thrombin exists as an ensemble of active (E) and inactive (E*) conformations that differ in their accessibility to the active site. Here we show that redistribution of the E*-E equilibrium can be achieved by perturbing the electrostatic properties of the enzyme. Removal of the negative charge of the catalytic Asp102 or Asp189 in the primary specificity site destabilizes the E form and causes a shift in the 215-217 segment that compromises substrate entrance. Solution studies and existing structures of D102N document stabilization of the E* form. A new high-resolution structure of D189A also reveals the mutant in the collapsed E* form. These findings establish a new paradigm for the control of the E*-E equilibrium in the trypsin fold.

NprR-NprX Quorum-Sensing System Regulates the Algicidal Activity of Bacillus sp. Strain S51107 against Bloom-Forming Cyanobacterium Microcystis aeruginosa.

PubMed

Wu, Lishuang; Guo, Xingliang; Liu, Xianglong; Yang, Hong

2017-01-01

Harmful cyanobacterial blooms have severely impaired freshwater quality and threatened human health worldwide. Here, a Gram-positive bacterium, Bacillus sp. strain S51107, which exhibits strong algicidal activity against Microcystis aeruginosa , was isolated from Lake Taihu. We found that the algicidal activity of strain S51107 was regulated primarily by NprR-NprX quorum sensing (QS), in which the mature form of the signaling peptide NprX was identified as the SKPDIVG heptapeptide. Disruption of the nprR-nprX cassette markedly decreased the algicidal activity, and complemented strains showed significantly recovered algicidal activity. Strain S51107 produced low-molecular-weight algicidal compounds [indole-3-carboxaldehyde and cyclo(Pro-Phe)] and high-molecular-weight algicidal substance(s) (>3 kDa). Moreover, the production of high-molecular-weight algicidal substance(s) was regulated by NprR-NprX QS, but the production of low-molecular-weight algicidal compounds was not. High-molecular-weight algicidal substance(s) played a more important role than low-molecular-weight algicidal compounds in the algicidal activity of strain S51107. The results of this study could increase our knowledge about algicidal characteristics of a potential algicidal bacterium, Bacillus sp. strain S51107, and provide the first evidence that the algicidal activity of Gram-positive algicidal bacteria is regulated by QS, which will greatly enhance our understanding of the interactions between algae and indigenous algicidal bacteria, thereby providing aid in the design and optimization of strategies to control harmful algae blooms.

NprR-NprX Quorum-Sensing System Regulates the Algicidal Activity of Bacillus sp. Strain S51107 against Bloom-Forming Cyanobacterium Microcystis aeruginosa

PubMed Central

Wu, Lishuang; Guo, Xingliang; Liu, Xianglong; Yang, Hong

2017-01-01

Harmful cyanobacterial blooms have severely impaired freshwater quality and threatened human health worldwide. Here, a Gram-positive bacterium, Bacillus sp. strain S51107, which exhibits strong algicidal activity against Microcystis aeruginosa, was isolated from Lake Taihu. We found that the algicidal activity of strain S51107 was regulated primarily by NprR-NprX quorum sensing (QS), in which the mature form of the signaling peptide NprX was identified as the SKPDIVG heptapeptide. Disruption of the nprR-nprX cassette markedly decreased the algicidal activity, and complemented strains showed significantly recovered algicidal activity. Strain S51107 produced low-molecular-weight algicidal compounds [indole-3-carboxaldehyde and cyclo(Pro-Phe)] and high-molecular-weight algicidal substance(s) (>3 kDa). Moreover, the production of high-molecular-weight algicidal substance(s) was regulated by NprR-NprX QS, but the production of low-molecular-weight algicidal compounds was not. High-molecular-weight algicidal substance(s) played a more important role than low-molecular-weight algicidal compounds in the algicidal activity of strain S51107. The results of this study could increase our knowledge about algicidal characteristics of a potential algicidal bacterium, Bacillus sp. strain S51107, and provide the first evidence that the algicidal activity of Gram-positive algicidal bacteria is regulated by QS, which will greatly enhance our understanding of the interactions between algae and indigenous algicidal bacteria, thereby providing aid in the design and optimization of strategies to control harmful algae blooms. PMID:29075240

The Effects of Allium sativum Extracts on Biofilm Formation and Activities of Six Pathogenic Bacteria

PubMed Central

Mohsenipour, Zeinab; Hassanshahian, Mehdi

2015-01-01

Background: Garlic is considered a rich source of many compounds, which shows antimicrobial effects. The ability of microorganisms to adhere to both biotic and abiotic surfaces and to form biofilm is responsible for a number of diseases of chronic nature, demonstrating extremely high resistance to antibiotics. Bacterial biofilms are complex communities of sessile microorganisms, embedded in an extracellular matrix and irreversibly attached to various surfaces. Objectives: The present study evaluated the antimicrobial activity of Allium sativum extract against the biofilms of six pathogenic bacteria and their free-living forms. The clinical isolates in this study had not been studied in any other studies, especially in regard to biofilm disruption and inhibition of biofilm cell metabolic activity. Materials and Methods: Antimicrobial activities of A. sativum L. extracts (methanol and ethanol extracts) against planktonic forms of bacteria were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were evaluated by a macrobroth dilution technique. The anti-biofilm effects were assessed by microtiter plate method. Results: The results showed that the A. sativum L. extract discs did not have any zone of inhibition for the tested bacteria. However, The MIC values of A. sativum L. extracts (0.078 - 2.5 mg/mL) confirmed the high ability of these extracts for inhibition of planktonic bacteria. A. sativum L. extracts were efficient to inhibit biofilm structures and the concentration of each extract had a direct relation with the inhibitory effect. Conclusions: Finally, it can be suggested that the extracts of this plant be applied as antimicrobial agents against these pathogens, particularly in biofilm forms. PMID:26464762

Adiponectin Receptors Form Homomers and Heteromers Exhibiting Distinct Ligand Binding and Intracellular Signaling Properties*

PubMed Central

Almabouada, Farid; Diaz-Ruiz, Alberto; Rabanal-Ruiz, Yoana; Peinado, Juan R.; Vazquez-Martinez, Rafael; Malagon, Maria M.

2013-01-01

Adiponectin binds to two widely expressed receptors (AdipoR1 and AdipoR2) that contain seven transmembrane domains but, unlike G-protein coupled receptors, present an extracellular C terminus and a cytosolic N terminus. Recently, AdipoR1 was found to associate in high order complexes. However, it is still unknown whether AdipoR2 may also form homomers or heteromers with AdipoR1 or if such interactions may be functionally relevant. Herein, we have analyzed the oligomerization pattern of AdipoRs by FRET and immunoprecipitation and evaluated both the internalization of AdipoRs in response to various adiponectin isoforms and the effect of adiponectin binding to different AdipoR combinations on AMP-activated protein kinase phosphorylation and peroxisome proliferator-activated receptor α activation. Transfection of HEK293AD cells with AdipoR1 and AdipoR2 showed that both receptors colocalize at both the plasma membrane and the endoplasmic reticulum. Co-transfection with the different AdipoR pairs yielded high FRET efficiencies in non-stimulated cells, which indicates that AdipoR1 and AdipoR2 form homo- and heteromeric complexes under resting conditions. Live FRET imaging suggested that both homo- and heteromeric AdipoR complexes dissociate in response to adiponectin, but heteromers separate faster than homomers. Finally, phosphorylation of AMP-activated protein kinase in response to adiponectin was delayed in cells wherein heteromer formation was favored. In sum, our findings indicate that AdipoR1 and AdipoR2 form homo- and heteromers that present unique interaction behaviors and signaling properties. This raises the possibility that the pleiotropic, tissue-dependent functions of adiponectin depend on the expression levels of AdipoR1 and AdipoR2 and, therefore, on the steady-state proportion of homo- and heteromeric complexes. PMID:23255609

Adiponectin receptors form homomers and heteromers exhibiting distinct ligand binding and intracellular signaling properties.

PubMed

Almabouada, Farid; Diaz-Ruiz, Alberto; Rabanal-Ruiz, Yoana; Peinado, Juan R; Vazquez-Martinez, Rafael; Malagon, Maria M

2013-02-01

Adiponectin binds to two widely expressed receptors (AdipoR1 and AdipoR2) that contain seven transmembrane domains but, unlike G-protein coupled receptors, present an extracellular C terminus and a cytosolic N terminus. Recently, AdipoR1 was found to associate in high order complexes. However, it is still unknown whether AdipoR2 may also form homomers or heteromers with AdipoR1 or if such interactions may be functionally relevant. Herein, we have analyzed the oligomerization pattern of AdipoRs by FRET and immunoprecipitation and evaluated both the internalization of AdipoRs in response to various adiponectin isoforms and the effect of adiponectin binding to different AdipoR combinations on AMP-activated protein kinase phosphorylation and peroxisome proliferator-activated receptor α activation. Transfection of HEK293AD cells with AdipoR1 and AdipoR2 showed that both receptors colocalize at both the plasma membrane and the endoplasmic reticulum. Co-transfection with the different AdipoR pairs yielded high FRET efficiencies in non-stimulated cells, which indicates that AdipoR1 and AdipoR2 form homo- and heteromeric complexes under resting conditions. Live FRET imaging suggested that both homo- and heteromeric AdipoR complexes dissociate in response to adiponectin, but heteromers separate faster than homomers. Finally, phosphorylation of AMP-activated protein kinase in response to adiponectin was delayed in cells wherein heteromer formation was favored. In sum, our findings indicate that AdipoR1 and AdipoR2 form homo- and heteromers that present unique interaction behaviors and signaling properties. This raises the possibility that the pleiotropic, tissue-dependent functions of adiponectin depend on the expression levels of AdipoR1 and AdipoR2 and, therefore, on the steady-state proportion of homo- and heteromeric complexes.

The Young Astrophysicist: A Very Inexpensive Activity to Discuss Spectroscopy

ERIC Educational Resources Information Center

Brockington, Guilherme; Testoni, Leonardo André; Pietrocola, Maurício

2015-01-01

The continuing fascination of young people with celestial bodies leads them to pose challenging questions to their science teachers, such as how was the universe born? How were the stars formed? In this paper we present an extremely inexpensive but highly engaging activity to teach the basics of spectroscopy. Guided by the question "how do…

Self-reflection and the psychosis-prone brain: an fMRI study.

PubMed

Modinos, Gemma; Renken, Remco; Ormel, Johan; Aleman, André

2011-05-01

The Cortical Midline Structures (CMS) play a critical role in self-reflection, together with the insula. Abnormalities in self-referential processing and its neural underpinnings have been reported in schizophrenia and at-risk populations, suggesting they might be markers of psychotic vulnerability. Psychometric measures of schizotypal traits may be used to index psychosis proneness (PP) in nonclinical samples. It remains an unresolved question whether differences in self-reflective processing are associated with PP. Six hundred students completed the Community Assessment of Psychic Experiences Questionnaire, positive subscale. Two groups were formed from the extremes of the distribution (total N = 36). fMRI was used to examine CMS/insula function during a self-reflection task. Participants judged personality trait sentences about self and about an acquaintance. High PP subjects attributed less positive traits to others (i.e., acquaintances) than subjects with low PP. Across groups, the contrasts self > semantic and self > other induced activation in CMS and insula, whereas other > semantic did not produce insula activation. Other > self induced posterior cingulate cortex activation in low PP but not in high PP. In addition, high PP subjects showed stronger activation than low PP in left insula during self > semantic. Examining valence effects revealed that high PP individuals showed increased activation in left insula, right dMPFC, and left vMPFC for positive self-related traits, and in bilateral insula, ACC, and right dMPFC for negative self-related traits. The findings suggest that aspects of self-referential processing and underlying brain mechanisms are similar in clinical and subclinical (high PP) forms of psychosis, suggesting that these may be associated with vulnerability to psychosis.

School and class-level variations and patterns of physical activity: a multilevel analysis of Danish high school students.

PubMed

Steenholt, Carina Bjørnskov; Pisinger, Veronica Sofie Clara; Danquah, Ida Høgstedt; Tolstrup, Janne Schurmann

2018-02-14

There is limited knowledge of physical activity (PA) patterns among high school students. High schools plays an important role as context for the students, but it is uncertain to what extent schools influence student participation in PA during leisure time. The purpose of this study is to describe patterns of PA and assess variations between schools and classes in PA, in a large cohort of Danish high school students. Self-reported cross-sectional data came from The Danish National Youth Study, comprising a total of 70,674 students attending 119 different schools and 3213 classes. Multilevel logistic regressions were applied to evaluate the association between socio-demographic variables and patterns of PA, and to assess the impact of schools and classes on PA measures. Students whose parents have achieved a lower level of education, older students and girls of perceived ethnic minority generally participated less in several forms of PA during leisure time. Substantial variations between schools were observed in terms of participation in PA at school during leisure time and in terms of use of active transportation to and from school. The school-level accounted for 9% (intra-class correlation coefficient (ICC) = 0.09 (95% CI: 0.06-0.11)) and 8% (ICC = 0.08 (95% CI: 0.07-0.11)) of the variation for participation in PA during leisure time and active transportation. Overall, students whose parents achieved a lower level of education, older students and girls of perceived ethnic minority represent vulnerable groups in relation to participation in several forms of PA during leisure time. The ICCs indicate that schools, in particular, have the potential to influence participation in PA at school during leisure time and active transportation to and from school. Thus, high schools should encourage and facilitate activities aimed at engaging students in PA during leisure time as well as encourage active transportation.

Inhibition of the pore-forming protein perforin by a series of aryl-substituted isobenzofuran-1(3H)-ones.

PubMed

Spicer, Julie A; Huttunen, Kristiina M; Miller, Christian K; Denny, William A; Ciccone, Annette; Browne, Kylie A; Trapani, Joseph A

2012-02-01

An aryl-substituted isobenzofuran-1(3H)-one lead compound was identified from a high throughput screen designed to find inhibitors of the lymphocyte pore-forming protein perforin. A series of analogs were then designed and prepared, exploring structure-activity relationships through variation of 2-thioxoimidazolidin-4-one and furan subunits on an isobenzofuranone core. The ability of the resulting compounds to inhibit the lytic activity of both isolated perforin protein and perforin delivered in situ by intact KHYG-1 natural killer effector cells was determined. Several compounds showed excellent activity at concentrations that were non-toxic to the killer cells. This series represents a significant improvement on previous classes of compounds, being substantially more potent and largely retaining activity in the presence of serum. Copyright © 2011 Elsevier Ltd. All rights reserved.

The physical activity climate in Minnesota middle and high schools.

PubMed

Samuelson, Anne; Lytle, Leslie; Pasch, Keryn; Farbakhsh, Kian; Moe, Stacey; Sirard, John Ronald

2010-11-01

This article describes policies, practices, and facilities that form the physical activity climate in Minneapolis/St. Paul, Minnesota metro area middle and high schools and examines how the physical activity climate varies by school characteristics, including public/private, school location and grade level. Surveys examining school physical activity practices, policies and environment were administered to principals and physical education department heads from 115 middle and high schools participating in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA) study. While some supportive practices were highly prevalent in the schools studied (such as prohibiting substitution of other classes for physical education); other practices were less common (such as providing opportunity for intramural (noncompetitive) sports). Public schools vs. private schools and schools with a larger school enrollment were more likely to have a school climate supportive of physical activity. Although schools reported elements of positive physical activity climates, discrepancies exist by school characteristics. Of note, public schools were more than twice as likely as private schools to have supportive physical activity environments. Establishing more consistent physical activity expectations and funding at the state and national level is necessary to increase regular school physical activity.

H2S-mediated thermal and photochemical methane activation.

PubMed

Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric V

2013-12-02

Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with methane, deemed altogether as sub-quality or "sour" gas. We propose a unique method of activation to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3 , and an energy carrier such as H2. For this purpose, we investigated the H2S-mediated methane activation to form a reactive CH3SH species by means of direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4 + H2S complex resulted in a barrierless relaxation by a conical intersection to form a ground-state CH3SH + H2 complex. The resulting CH3SH could further be coupled over acidic catalysts to form higher hydrocarbons, and the resulting H2 used as a fuel. This process is very different from conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced control over the conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the current industrial steam methane reforming (SMR). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method of forming thermally stable high-resistivity regions in n-type indium phosphide by oxygen implantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, P.E.; Dietrich, H.B.

1985-12-12

Objects of this invention are: to form high-temperature stable isolation regions in InP; to provide InP wafers that allow greater flexibility in the design and fabrication of discrete devices; to provide new and improved InP semiconductor devices in n-type InP; to provide high-resisitivity isolation regions in InP; to extend the usefulness of damage-induced isolation in n-type InP by making possible processes in which the isolation implantation precedes the alloying of ohmic contacts; and to provide n-type InP substrates without unwanted conductive layers. The above and other object are realized by an InP wafer comprising a S.I. InP substrate; a n-typemore » InP active layer disposed on the substrate; and oxygen ion implanted isolation regions disposed in the active layer. The S.I. InP dopant may comprise either Fe or Cr.« less

Coated platelets function in platelet-dependent fibrin formation via integrin αIIbβ3 and transglutaminase factor XIII

PubMed Central

Mattheij, Nadine J.A.; Swieringa, Frauke; Mastenbroek, Tom G.; Berny-Lang, Michelle A.; May, Frauke; Baaten, Constance C.F.M.J.; van der Meijden, Paola E.J.; Henskens, Yvonne M.C.; Beckers, Erik A.M.; Suylen, Dennis P.L.; Nolte, Marc W.; Hackeng, Tilman M.; McCarty, Owen J.T.; Heemskerk, Johan W.M.; Cosemans, Judith M.E.M.

2016-01-01

Coated platelets, formed by collagen and thrombin activation, have been characterized in different ways: i) by the formation of a protein coat of α-granular proteins; ii) by exposure of procoagulant phosphatidylserine; or iii) by high fibrinogen binding. Yet, their functional role has remained unclear. Here we used a novel transglutaminase probe, Rhod-A14, to identify a subpopulation of platelets with a cross-linked protein coat, and compared this with other platelet subpopulations using a panel of functional assays. Platelet stimulation with convulxin/thrombin resulted in initial integrin αIIbβ3 activation, the appearance of a platelet population with high fibrinogen binding, (independently of active integrins, but dependent on the presence of thrombin) followed by phosphatidylserine exposure and binding of coagulation factors Va and Xa. A subpopulation of phosphatidylserine-exposing platelets bound Rhod-A14 both in suspension and in thrombi generated on a collagen surface. In suspension, high fibrinogen and Rhod-A14 binding were antagonized by combined inhibition of transglutaminase activity and integrin αIIbβ3. Markedly, in thrombi from mice deficient in transglutaminase factor XIII, platelet-driven fibrin formation and Rhod-A14 binding were abolished by blockage of integrin αIIbβ3. Vice versa, star-like fibrin formation from platelets of a patient with deficiency in αIIbβ3 (Glanzmann thrombasthenia) was abolished upon blockage of transglutaminase activity. We conclude that coated platelets, with initial αIIbβ3 activation and high fibrinogen binding, form a subpopulation of phosphatidylserine-exposing platelets, and function in platelet-dependent star-like fibrin fiber formation via transglutaminase factor XIII and integrin αIIbβ3. PMID:26721892

Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagvall, Lina; Baron, Jens Malte; Boerje, Anna

2008-12-01

Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktailmore » consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.« less

Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens.

PubMed

Hagvall, Lina; Baron, Jens Malte; Börje, Anna; Weidolf, Lars; Merk, Hans; Karlberg, Ann-Therese

2008-12-01

Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktail consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.

Nanotwin Formation in High-Manganese Austenitic Steels Under Explosive Shock Loading

NASA Astrophysics Data System (ADS)

Canadinc, D.; Uzer, B.; Elmadagli, M.; Guner, F.

2018-04-01

The micro-deformation mechanisms active in a high-manganese austenitic steel were investigated upon explosive shock loading. Single system of nanotwins forming within primary twins were shown to govern the deformation despite the elevated temperatures attained during testing. The benefits of nanotwin formation for potential armor materials were demonstrated.

Comparison of authigenic carbonates formation at mud volcanoes and pockmarks in the Portuguese Margin vs. at the Yinazao serpentinite mud volcano in the Marianas forearc

NASA Astrophysics Data System (ADS)

Magalhaes, V. H.; Freitas, M.; Azevedo, M. R.; Pinheiro, L. M.; Salgueiro, E.; Abrantes, F. F. G.

2017-12-01

On the Portuguese passive continental margin, active and past seepage processes form mud volcanoes and pockmarks at the seafloor. Often associated with these structures are extensive methane-derived authigenic carbonates that form from deep-sourced methane-rich fluids that ascend from deep to the upper sedimentary column and often discharge at the seafloor. These carbonates form within the sediments and are either dominated by dolomite and high-Mg calcites, when formed under a restricted seawater circulation environment, anoxic and low sulphate conditions; or by aragonite and calcite when formed close to or at the seafloor in a high sulphate system. The δ13C values (-56.2‰ VPDB) found on the carbonate-cemented material clearly indicates methane as the major carbon source. On the Yinazao serpentinite mud volcano at an active, non-accretionary, convergent margin, sediment samples from IODP Sites U1491 and U1492 (Exp. 366) contain authigenic minerals such as aragonite, calcite, brucite, gypsum among others. Authigenic aragonite occurs predominantly within the top meters of the cores where both oxidation and seawater circulation in the sedimentary column are higher. In this system, initial results indicate that the major carbon source is most probably not methane but seawater related. This work discusses and compares the major carbon sources in both systems: sedimentary mud volcanoes and pockmarks of a passive margin vs. a serpentinite mud volcano of an active, non-accretionary, convergent margin. We acknowledge the support from the PES project - Pockmarks and fluid seepage in the Estremadura Spur: implications for regional geology, biology, and petroleum systems (PTDC/GEOFIQ/5162/2014) financed by the Portuguese Foundation for Science and Technology (FCT).

Fracture Simulation of Highly Crosslinked Polymer Networks: Triglyceride-Based Adhesives

NASA Astrophysics Data System (ADS)

Lorenz, Christian; Stevens, Mark; Wool, Richard

2003-03-01

The ACRES program at the U. of Delaware has shown that triglyceride oils derived from plants are a favorable alternative to the traditional adhesives. The triglyceride networks are formed from an initial mixture of styrene monomers, free-radical initiators and triglycerides. We have performed simulations to study the effect of physical composition and physical characteristics of the triglyceride network on the strength of triglyceride network. A coarse-grained, bead-spring model of the triglyceride system is used. The average triglyceride consists of 6 beads per chain, the styrenes are represented as a single bead and the initiators are two bead chains. The polymer network is formed using an off-lattice 3D Monte Carlo simulation, in which the initiators activate the styrene and triglyceride reactive sites and then bonds are randomly formed between the styrene and active triglyceride monomers producing a highly crosslinked polymer network. Molecular dynamics simulations of the network under tensile and shear strains were performed to determine the strength as a function of the network composition. The relationship between the network structure and its strength will also be discussed.

The polar high molecular weight fraction of the Agaricus blazei Murill extract, AndoSan™, reduces the activity of the tumor-associated protease, legumain, in RAW 264.7 cells.

PubMed

Berven, Lise; Karppinen, Pernille; Hetland, Geir; Samuelsen, Anne Berit C

2015-04-01

AndoSan™ is an extract of Agaricus blazei Murill (AbM; 82.4%), Hericium erinaceum (14.7%), and Grifola frondosa (2.9%). The main ingredient of AndoSan, AbM, is rich in different forms of β-glucans. Since these exhibit potent antitumor activity and have immunomodulatory effects, the stimulatory effect of AndoSan on the production of different cytokines, chemokines, and leukocyte growth factors has predominantly been attributed to β-glucans. AndoSan has been claimed to consist of 90% carbohydrate, of which 2.8% is β-glucans, but in this study, we show that the carbohydrate content is only 2% of the dry weight, corresponding to 0.09% β-glucan per mL of AndoSan. Fractionation of AndoSan, followed by carbohydrate analysis and HPLC analysis revealed that most of the glucose was concentrated in the polar high molecular weight fraction of AndoSan (ethanol insoluble water extract [EIWE]-A) and that this extract was able to significantly inhibit the activity of the tumor-associated protease, legumain, in RAW 264.7 cells. Legumain is synthesized as a zymogen and undergoes pH-dependent autoactivation of the proform to reach an enzymatically active form. In this study, we demonstrate that both the polar and nonpolar AndoSan fractions are able to inhibit the autoactivation of prolegumain, and that the polar fractions of AndoSan are the most potent inhibitors of the active form of the enzyme.

Evidence for functional heterogeneity of circulating B-type natriuretic peptide.

PubMed

Liang, Faquan; O'Rear, Jessica; Schellenberger, Ute; Tai, Lungkuo; Lasecki, Michael; Schreiner, George F; Apple, Fred S; Maisel, Alan S; Pollitt, N Stephen; Protter, Andrew A

2007-03-13

These studies describe molecular forms of circulating B-type natriuretic peptide (BNP) as well as their biological activity. Increased circulating levels of immunoreactive BNP correlate with the severity of heart failure and are considered a sensitive biomarker. However, little is known about the molecular forms of circulating BNP and their biological activity. Western blot analysis was used to characterize immunoreactive BNP species in heart failure plasma. Recombinant proBNP was assessed for reactivity in commercially available BNP assays and cell activity by cyclic guanosine monophosphate production in vascular cells. Heart failure plasma contained both low- (LMW-BNP) and high-molecular-weight (HMW-BNP) forms. The LMW-BNP migrated similarly to a 32-amino acid BNP standard, whereas HMW-BNP, when deglycosylated, was similar to deglycosylated recombinant proBNP. Recombinant proBNP and BNP were equally recognized by the Triage BNP assay (Biosite, San Diego, California). Furthermore, recombinant proBNP and BNP were both recognized by the Advia Centaur BNP test (Bayer Diagnostics, Tarrytown, New York), but only recombinant proBNP was recognized by the Elecsys NTproBNP assay (Roche Diagnostics, Indianapolis, Indiana). Recombinant proBNP exerted significantly less biological activity than BNP on human endothelial and vascular smooth muscle cells. Comparison of effective concentration (50%) values indicates that proBNP is 6- to 8-fold less potent than BNP in these human cells. This study demonstrates that proBNP, constituting a substantial portion of immunoreactive BNP in heart failure plasma, possesses significantly lower biological activity than the processed 32-amino acid hormone. These results implicate a discordance in heart failure between the high circulating levels of immunoreactive BNP and hormone activity, suggesting that some patients may be in a state of natriuretic peptide deficiency.

Nature of active tin species and promoting effect of nickle in silica supported tin oxide for dehydrogenation of propane

NASA Astrophysics Data System (ADS)

Wang, Haoren; Wang, Hui; Li, Xiuyi; Li, Chunyi

2017-06-01

Different with Wang et. al.'s study, we found that polymeric Si-O-Sn2+ rather than Ni-Sn alloy and metallic Sn are active species in silica-supported tin oxide catalysts for dehydrogenation of propane. The results showed that high surface area of mesoporous silica brought about high dispersion of tin oxide species, as a result, catalytic activity and stability were both improved. DRUV-vis, XPS, TPR and XRD studies of fresh and reduced catalysts indicated that the deactivation was related to the reduction of active species rather than the coke formation since active tin species cannot maintain its oxidation state at reaction conditions (high temperature and reducing atmosphere). The formed Ni3Sn2 alloy after reduction just functioned as promoter which accelerated the desorption of H2 and regeneration of active site. A synergy effect between active tin species and Ni3Sn2 alloy were observed.

[Chemical forms and ecological effect of soil Mn in liver cancer's high incidence area in Zhu-jiang River Delta, China].

PubMed

Dou, Lei; Zhou, Yong-Zhang; Li, Yong; Ma, Jin; An, Yan-Fei; Du, Hai-Yan; Li, Zhan-Qiang

2008-06-01

The samples of surface soil, deep soil, and vegetables were collected from the liver cancer's high- and low incidence areas in Zhujiang River Delta to study the relationships between soil Mn forms and vegetables' Mn enrichment. The results showed that the soil Mn in study area was mainly derived from parent materials, and rarely come from human activities. The average soil Mn content in liver cancer's high incidence area was 577.65 mg x kg(-1), being significantly lower than that of liver cancer's low incidence area (718.04 mg x kg(-1)) and whole country (710 mg x kg(-1)). The Mn forms in high incidence area were mainly of residual Mn and Fe-Mn oxide, and less of water soluble Mn and exchangeable Mn, with the sum of the latter two's distribution coefficients being not higher than 4%. In low incidence area, the distribution pattern of soil Mn forms was similar to that in high incidence area, but the absolute contents of the Mn forms were significantly higher. Soil total Mn and soil pH had significant effects on soil Mn forms. There existed significant positive correlations between soil total Mn and the Mn forms of Fe-Mn bound, humic acid bound, carbonate bound, and residual, and negative correlations between soil pH and soil water soluble and organic bound Mn forms. Among the test five kinds of vegetables, Youmai lettuce and Chinese cabbage in liver cancer' s high incidence area had a significantly lower Mn content than in low incidence area, while the other three had less difference. The Mn enrichment in test vegetables was positively correlated with to the content of soil available Mn (sum of water soluble Mn and exchangeable Mn), but had no correlations with the contents of soil total Mn and other Mn forms.

Performance of Ceramics in Severe Environments

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Fox, Dennis S.; Smialek, James L.; Deliacorte, Christopher; Lee, Kang N.

2005-01-01

Ceramics are generally stable to higher temperatures than most metals and alloys. Thus the development of high temperature structural ceramics has been an area of active research for many years. While the dream of a ceramic heat engine still faces many challenges, niche markets are developing for these materials at high temperatures. In these applications, ceramics are exposed not only to high temperatures but also aggressive gases and deposits. In this chapter we review the response of ceramic materials to these environments. We discuss corrosion mechanisms, the relative importance of a particular corrodent, and, where available, corrosion rates. Most of the available corrosion information is on silicon carbide (SIC) and silicon nitride (Si3N4) monolithic ceramics. These materials form a stable film of silica (SO2) in an oxidizing environment. We begin with a discussion of oxidation of these materials and proceed to the effects of other corrodents such as water vapor and salt deposits. We also discuss oxidation and corrosion of other ceramics: precurser derived ceramics, ceramic matrix composites (CMCs), ceramics which form oxide scales other than silica, and oxide ceramics. Many of the corrosion issues discussed can be mitigated with refractory oxide coatings and we discuss the current status of this active area of research. Ultimately, the concern of corrosion is loss of load bearing capability. We discuss the effects of corrosive environments on the strength of ceramics, both monolithic and composite. We conclude with a discussion of high temperature wear of ceramics, another important form of degradation at high temperatures.

High efficiency of CO2-activated graphite felt as electrode for vanadium redox flow battery application

NASA Astrophysics Data System (ADS)

Chang, Yu-Chung; Chen, Jian-Yu; Kabtamu, Daniel Manaye; Lin, Guan-Yi; Hsu, Ning-Yih; Chou, Yi-Sin; Wei, Hwa-Jou; Wang, Chen-Hao

2017-10-01

A simple method for preparing CO2-activated graphite felt as an electrode in a vanadium redox flow battery (VRFB) was employed by the direct treatment in a CO2 atmosphere at a high temperature for a short period. The CO2-activated graphite felt demonstrates excellent electrochemical activity and reversibility. The VRFB using the CO2-activated graphite felts in the electrodes has coulombic, voltage, and energy efficiencies of 94.52%, 88.97%, and 84.15%, respectively, which is much higher than VRFBs using the electrodes of untreated graphite felt and N2-activated graphite felt. The efficiency enhancement was attributed to the higher number of oxygen-containing functional groups on the graphite felt that are formed during the CO2-activation, leading to improving the electrochemical behaviour of the resultant VRFB.

The Gly-54-->Asp allelic form of human mannose-binding protein (MBP) fails to bind MBP-associated serine protease.

PubMed Central

Matsushita, M; Ezekowitz, R A; Fujita, T

1995-01-01

The human mannose-binding protein (MBP) is a pattern recognition molecule that appears to play a role in initial host defence. MBP activates the complement cascade and it may act as an opsonin both in the absence and in the presence of complement. A number of distinct MBP allelic forms exist in different population groups. An allele that occurs in 5-7% of Caucasians was identified by an inability to activate the complement system. A homozygous mutation at base pair 230 of the MBP gene results in a Gly-to-Asp substitution at the fifth collagen repeat. It appears that the resultant protein, MBPD, is able to form high-order multimers that bind bacteria but do not support complement activation. Recently a novel serine protease, the MBP-associated serine protease (MASP), has been described. MBP-MASP complexes circulate in serum and result in the direct activation of a novel complement pathway (lectin pathway) in the absence of the first complement components. In this study we demonstrate that MASP and its proenzyme proMASP are unable to bind to recombinant (r)MBPD. This lack of a MASP-rMBPD association corresponds to a failure of the Gly-54-->Asp form of MBP to activate complement. Our results provide a biochemical basis for the functional deficit in the Gly-54-->Asp allelic form of MBP and suggest that the proMASP/MASP binding site maps to the fifth collagen repeat of MBP. Images Figure 1 PMID:7487919

Method for making a monolithic integrated high-T.sub.c superconductor-semiconductor structure

NASA Technical Reports Server (NTRS)

Burns, Michael J. (Inventor); de la Houssaye, Paul R. (Inventor); Russell, Stephen D. (Inventor); Garcia, Graham A. (Inventor); Barfknecht, Andrew T. (Inventor); Clayton, Stanley R. (Inventor)

2000-01-01

A method for the fabrication of active semiconductor and high-temperature perconducting devices on the same substrate to form a monolithically integrated semiconductor-superconductor (MISS) structure is disclosed. A common insulating substrate, preferably sapphire or yttria-stabilized zirconia, is used for deposition of semiconductor and high-temperature superconductor substructures. Both substructures are capable of operation at a common temperature of at least 77 K. The separate semiconductor and superconductive regions may be electrically interconnected by normal metals, refractory metal silicides, or superconductors. Circuits and devices formed in the resulting MISS structures display operating characteristics which are equivalent to those of circuits and devices prepared on separate substrates.

Selective Action of the Iminosugar Isofagomine, a Pharmacological Chaperone For Mutant Forms of Acid-β-Glucosidase

PubMed Central

Steet, Richard; Chung, Stephen; Lee, Wang-Sik; Pine, Corey W.; Do, Hung; Kornfeld, Stuart

2007-01-01

Gaucher disease is a lysosomal glycolipid storage disorder characterized by defects in acid-β-glucosidase (GlcCerase), the enzyme responsible for the catabolism of glucosylceramide. We recently demonstrated that isofagomine (IFG), an iminosugar that binds to the active site of GlcCerase, enhances the folding, transport and activity of the N370S mutant form of GlcCerase. In this study we compared the effects of IFG on a number of other glucosidases and glucosyltransferases. We report that IFG has little or no inhibitory activity towards intestinal disaccharidase enzymes, ER α-glucosidase II or glucosylceramide synthase at concentrations previously shown to enhance N370S GlcCerase folding and trafficking in Gaucher fibroblasts. Furthermore, treatment of wild type fibroblasts with high doses of IFG did not alter the processing of newly synthesized N-linked oligosaccharides. These findings support further evaluation of IFG as a potential therapeutic agent in the treatment of some forms of Gaucher disease. PMID:17217920

A contribution to examination of propidium iodide and annexin V plasma cells indices in multiple myeloma.

PubMed

Scudla, V; Ordeltova, M; Bacovsky, J; Vytrasova, M; Sumna, E; Martinek, A; Horak, P

2003-01-01

The aim of this study was a contemporaneous measurement and a mutual comparison of plasma cells proliferative activity and grade of apoptosis in patients with monoclonal gammopathy of undetermined significance (MGUS) and various phases of MM i.e. smoldering (SMM), stable/plateau and active (progression/relapse) forms of this disease. The analyzed group of 197 patients consisted of 30 MGUS, 21 SMM, 82 patients examined at the time of MM diagnosis and 64 patients analyzed during various phases of the disease after previous chemotherapy. Plasma cell proliferative activity was measured by means of a propidium iodide index (PC-PI) examined by flow cytometry using a DNA/CD138 double staining technique. For detection of plasma cells entering apoptosis (PC-AI) flow cytometry method with annexin V FITC and MoAb CD138 was used. The individuals with MGUS, SMM and stable/plateau form of MM had overall low levels of PC-PI (M-1.8, 1.7% and 2.1%) and relatively high levels of PC-AI (M-9.1, 10.8 and 9.0%). The correlation between PC-PI and PC-AI was in all the groups mutually highly statistically significant (p=0.000). Analysis of plasma cells proliferative activity (PC-PI) was statistically significant in comparison of MGUS or SMM and versus: patients examined at the time of MM diagnosis (p=0.018 or 0.016); patients evaluated during various phases of MM after previous chemotherapy (p=0.021 or 0.019); stable/plateau MM phase in the cohort of all patients (p=0.017 or 0.040); in the plateau phase after chemotherapy (p=0.008 or 0.024) but insignificant in comparison of MGUS and SMM and with the stable group examined at the time of MM diagnosis. Analysis of the apoptotic process revealed significant differences when comparing PC-AI of SMM but not MGUS group versus all cohort of stable/plateau MM patients (p=0.045); there were also insignificant differences in comparison of MGUS and SMM groupsand versus the stable form of MM measured at the time of MM diagnosis or plateau phase after chemotherapy. There was observed a statistically significant difference in the PC-AI in comparison of SMM group versus group of all patients examined at the time of MM diagnosis (p=0.001) or in various phases of this disease (p=0.015) and the group of MGUS patients compared with patients evaluated at the time of MM diagnosis (p=0.03). Very significant statistical differences of plasma cell proliferative (PC-PI) and apoptotic (PC-AI) activity were found when comparing the levels of both the indices of MGUS, SMM and stable/plateau MM group versus the active (progression/relapse) form of MM marked by a higher level of PC-PI (3.2%, p=0.000) and PC-AI (4.8%, p=0.000) in the whole cohort of MM patients, but also in comparison with both the active forms at the time of MM diagnosis or active forms evaluated during various phases of the disease after chemotherapy. Highly significant inverse relationship between PC-PI versus PC-AI was also revealed in the group of patients in the active (progression/relapse) phase of MM (p=0.000). These results revealed importance of measurement not only of proliferative but also of apoptotic plasma cells indices for a complex evaluation of the cells kinetics of plasma cells compartments in patients with MGUS or MM. This study confirmed the initial hypothesis of a common 'inverse relationship between the proliferative (PC-PI) and the apoptosis activity (PC-AI) in plasma cells compartments in patients with MGUS, smoldering, stable/plateau and active (progression/ relapse) forms of MM'.

Effect of mechanical activation on jell boronizing treatment of the AISI 4140

NASA Astrophysics Data System (ADS)

Yılmaz, S. O.; Karataş, S.

2013-06-01

The article presents the effect of mechanical activation on the growth kinetics of boride layer of boronized AISI 4140 steel. The samples were boronized by ferroboron + (SiO2-Na2O) powders for 873-1173 K temperature and 2, 4, 6 and 8 h times, respectively. The morphology and types of borides formed on the surface of AISI 4140 steel substrate were analyzed. Layer growth kinetics were analyzed by measuring the extent of penetration of FeB and Fe2B sublayers as function of treatment time and temperature in the range of 873-1173 K. High diffusivity was obtained by creating a large number of defects through mechanical activation in the form of nanometer sized crystalline particles through the repeated fracturing and cold-welding of the powder particles, and a depth of 100 μm was found in the specimen borided by the 2 h MA powders, for 4 h and 1073 K, where 2000-2350 HV were measured. Consequently, the application conditions of boronizing were improved by usage of mechanical activation. The preferred Fe2B boride without FeB could be formed in the boride layer under 973 K boronizing temperature by mechanically activated by ferroboron + sodium silicate powder mixture due to the decrease of the activation energy.

Glasses having a low non-linear refractive index for laser applications

DOEpatents

Faulstich, Marga; Jahn, Walter; Krolla, Georg; Neuroth, Norbert

1980-01-01

Glass composition ranges are described which permit the introduction of laser activators into fluorphosphate glass with exceptionally high fluorine content while forming glasses of high crystallization stability and permitting the realization of large melt volumes. The high fluorine content imparts to the glasses an exceptionally low nonlinear refractive index n.sub.2 down to O,4 .times.10.sup.-13 esu.

The proteolytic system of pineapple stems revisited: Purification and characterization of multiple catalytically active forms.

PubMed

Matagne, André; Bolle, Laetitia; El Mahyaoui, Rachida; Baeyens-Volant, Danielle; Azarkan, Mohamed

2017-06-01

Crude pineapple proteases extract (aka stem bromelain; EC 3.4.22.4) is an important proteolytic mixture that contains enzymes belonging to the cysteine proteases of the papain family. Numerous studies have been reported aiming at the fractionation and characterization of the many molecular species present in the extract, but more efforts are still required to obtain sufficient quantities of the various purified protease forms for detailed physicochemical, enzymatic and structural characterization. In this work, we describe an efficient strategy towards the purification of at least eight enzymatic forms. Thus, following rapid fractionation on a SP-Sepharose FF column, two sub-populations with proteolytic activity were obtained: the unbound (termed acidic) and bound (termed basic) bromelain fractions. Following reversible modification with monomethoxypolyethylene glycol (mPEG), both fractions were further separated on Q-Sepharose FF and SP-Sepharose FF, respectively. This procedure yielded highly purified molecular species, all titrating ca. 1 mol of thiol group per mole of enzyme, with distinct biochemical properties. N-terminal sequencing allowed identifying at least eight forms with proteolytic activity. The basic fraction contained previously identified species, i.e. basic bromelain forms 1 and 2, ananain forms 1 and 2, and comosain (MEROPS identifier: C01.027). Furthermore, a new proteolytic species, showing similarities with basic bomelain forms 1 and 2, was discovered and termed bromelain form 3. The two remaining species were found in the acidic bromelain fraction and were arbitrarily named acidic bromelain forms 1 and 2. Both, acidic bromelain forms 1, 2 and basic bromelain forms 1, 2 and 3 are glycosylated, while ananain forms 1 and 2, and comosain are not. The eight protease forms display different amidase activities against the various substrates tested, namely small synthetic chromogenic compounds (DL-BAPNA and Boc-Ala-Ala-Gly-pNA), fluorogenic compounds (like Boc-Gln-Ala-Arg-AMC, Z-Arg-Arg-AMC and Z-Phe-Arg-AMC), and proteins (azocasein and azoalbumin), suggesting a specific organization of their catalytic residues. All forms are completely inhibited by specific cysteine and cysteine/serine protease inhibitors, but not by specific serine and aspartic protease inhibitors, with the sole exception of pepstatin A that significantly affects acidic bromelain forms 1 and 2. For all eight protease forms, inhibition is also observed with 1,10-phenanthrolin, a metalloprotease inhibitor. Metal ions (i.e. Mn 2+ , Mg 2+ and Ca 2+ ) showed various effects depending on the protease under consideration, but all of them are totally inhibited in the presence of Zn 2+ . Mass spectrometry analyses revealed that all forms have a molecular mass of ca. 24 kDa, which is characteristic of enzymes belonging to the papain-like proteases family. Far-UV CD spectra analysis further supported this analysis. Interestingly, secondary structure calculation proves to be highly reproducible for all cysteine proteases of the papain family tested so far (this work; see also Azarkan et al., 2011; Baeyens-Volant et al., 2015) and thus can be used as a test for rapid identification of the classical papain fold. Copyright © 2017 Elsevier Ltd. All rights reserved.

Theta Frequency Stimulation Induces a Local Form of Late Phase LTP in the CA1 Region of the Hippocampus

ERIC Educational Resources Information Center

Huang, Yan-You; Kandel, Eric R.

2005-01-01

The late phase of LTP (L-LTP) is typically induced by repeated high-frequency stimulation. This form of LTP requires activation of transcription and translation and results in the cell-wide distribution of gene products that can be captured by other marked synapses. Here we report that theta frequency stimulation (5 Hz, 30 sec) applied to the…

In silico prediction of potential chemical reactions mediated by human enzymes.

PubMed

Yu, Myeong-Sang; Lee, Hyang-Mi; Park, Aaron; Park, Chungoo; Ceong, Hyithaek; Rhee, Ki-Hyeong; Na, Dokyun

2018-06-13

Administered drugs are often converted into an ineffective or activated form by enzymes in our body. Conventional in silico prediction approaches focused on therapeutically important enzymes such as CYP450. However, there are more than thousands of different cellular enzymes that potentially convert administered drug into other forms. We developed an in silico model to predict which of human enzymes including metabolic enzymes as well as CYP450 family can catalyze a given chemical compound. The prediction is based on the chemical and physical similarity between known enzyme substrates and a query chemical compound. Our in silico model was developed using multiple linear regression and the model showed high performance (AUC = 0.896) despite of the large number of enzymes. When evaluated on a test dataset, it also showed significantly high performance (AUC = 0.746). Interestingly, evaluation with literature data showed that our model can be used to predict not only enzymatic reactions but also drug conversion and enzyme inhibition. Our model was able to predict enzymatic reactions of a query molecule with a high accuracy. This may foster to discover new metabolic routes and to accelerate the computational development of drug candidates by enabling the prediction of the potential conversion of administered drugs into active or inactive forms.

Sorbents for the oxidation and removal of mercury

DOEpatents

Olson, Edwin S; Holmes, Michael J; Pavlish, John Henry

2013-08-20

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Sorbents for the oxidation and removal of mercury

DOEpatents

Olson, Edwin S [Grand Forks, ND; Holmes, Michael J [Thompson, ND; Pavlish, John H [East Grand Forks, MN

2008-10-14

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Sorbents for the oxidation and removal of mercury

DOEpatents

Olson, Edwin S [Grand Forks, ND; Holmes, Michael J [Thompson, ND; Pavlish, John H [East Grand Forks, MN

2012-05-01

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Sorbents for the oxidation and removal of mercury

DOEpatents

Olson, Edwin S.; Holmes, Michael J.; Pavlish, John Henry

2014-09-02

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

The Formation of CIRs at Stream-Stream Interfaces and Resultant Geomagnetic Activity

NASA Technical Reports Server (NTRS)

Richardson, I. G.

2005-01-01

Corotating interaction regions (CIRs) are regions of compressed plasma formed at the leading edges of corotating high-speed solar wind streams originating in coronal holes as they interact with the preceding slow solar wind. Although particularly prominent features of the solar wind during the declining and minimum phases of the 11-year solar cycle, they may also be present at times of higher solar activity. We describe how CIRs are formed, and their geomagnetic effects, which principally result from brief southward interplanetary magnetic field excursions associated with Alfven waves. Seasonal and long-term variations in these effects are briefly discussed.

The mystery of gold's chemical activity: local bonding, morphology and reactivity of atomic oxygen.

PubMed

Baker, Thomas A; Liu, Xiaoying; Friend, Cynthia M

2011-01-07

Recently, gold has been intensely studied as a catalyst for key synthetic reactions. Gold is an attractive catalyst because, surprisingly, it is highly active and very selective for partial oxidation processes suggesting promise for energy-efficient "green" chemistry. The underlying origin of the high activity of Au is a controversial subject since metallic gold is commonly thought to be inert. Herein, we establish that one origin of the high activity for gold catalysis is the extremely reactive nature of atomic oxygen bound in 3-fold coordination sites on metallic gold. This is the predominant form of O at low concentrations on the surface, which is a strong indication that it is most relevant to catalytic conditions. Atomic oxygen bound to metallic Au in 3-fold sites has high activity for CO oxidation, oxidation of olefins, and oxidative transformations of alcohols and amines. Among the factors identified as important in Au-O interaction are the morphology of the surface, the local binding site of oxygen, and the degree of order of the oxygen overlayer. In this Perspective, we present an overview of both theory and experiments that identify the reactive forms of O and their associated charge density distributions and bond strengths. We also analyze and model the release of Au atoms induced by O binding to the surface. This rough surface also has the potential for O(2) dissociation, which is a critical step if Au is to be activated catalytically. We further show the strong parallels between product distributions and reactivity for O-covered Au at low pressure (ultrahigh vacuum) and for nanoporous Au catalysts operating at atmospheric pressure as evidence that atomic O is the active species under working catalytic conditions when metallic Au is present. We briefly discuss the possible contributions of oxidants that may contain intact O-O bonds and of the Au-metal oxide support interface in Au catalysis. Finally, the challenges and future directions for fully understanding the activity of gold are considered.

Alaska Wildlife Week--Junior/Senior High School Teacher's Guide. Unit 7. Together, We Can Help Wildlife. April 23-29, 1989.

ERIC Educational Resources Information Center

Sigman, Marilyn, Ed.

Wildlife is often described as one of Alaska's most important and valuable resources. Helping wildlife can take many forms. In this educational packet, a variety of activities are included to help secondary school students understand which human activities help wildlife and which harm wildlife. In addition, suggestions on planning hands-on…

The Forming of Prospective Music Teacher's Readiness to Professional Activity in a Multicultural Society

ERIC Educational Resources Information Center

Salpykova, Indira M.; Politaeva, Tatyana I.

2016-01-01

The relevance of the researched problem is caused by the fact, that in modern social circumstances the special attention is given to the formation of a modern highly qualified music teacher, who should be prepared to implement his professional activity in a multicultural society, be able to treat the representatives of various social groups, their…

Promoting Lifelong Physical Activity and High Level Performance: Realising an Achievable Aim for Physical Education

ERIC Educational Resources Information Center

MacNamara, Aine; Collins, Dave; Bailey, Richard; Toms, Martin; Ford, Paul; Pearce, Gemma

2011-01-01

Background: Even though all school-aged children in most countries experience some form of curricular physical education many do not maintain a lifelong involvement in sport or physical activity. From a theoretical perspective, the development models that dominate sport are limited by their staged and linear approaches to development (e.g. Cote's…

En las Manos de Dios [in God's Hands]: Religious and Other Forms of Coping among Latinos with Arthritis

ERIC Educational Resources Information Center

Abraido-Lanza, Ana F.; Vasquez, Elizabeth; Echeverria, Sandra E.

2004-01-01

This study tested a theoretical model concerning religious, passive, and active coping; pain; and psychological adjustment among a sample of 200 Latinos with arthritis. Respondents reported using high levels of religious coping. A path analysis indicated that religious coping was correlated with active but not with passive coping. Religious coping…

Preparation and Characterization of Activated Alumina

NASA Astrophysics Data System (ADS)

Rabia, A. R.; Ibrahim, A. H.; Zulkepli, N. N.

2018-03-01

Activated alumina is a high surface area and highly porous form of aluminum oxide that can be employed for contaminant species adsorb from ether gases or liquids without changing its form. The research in getting this material has generated huge interested. Thus, this paper presented preparation of activated alumina from chemical process. Pure aluminum (99.9% pure) reacted at room temperature with an aqueous NaOH in a reactor to produce a solution of sodium aluminate (NaAlO2). This solution was passed through filter paper and the clear filtrate was neutralized with H2SO4, to pH 6, 7 or 8, resulting in the precipitation of a white gel, Al(OH)3·XH2O. The washed gel for sulfate ions were dried at 80 °C for 6 h, a 60 mesh sieve was to separate and sort them into different sizes. The samples were then calcined (burn) for 3h in a muffle furnace, in air, at a heating rate of 2 °C min-1. The prepared activated alumina was further characterized for better understanding of its physical properties in order to predict its chemical mechanism.

A phenomenological description of BslA assemblies across multiple length scales

PubMed Central

Morris, Ryan J.; Bromley, Keith M.; Stanley-Wall, Nicola

2016-01-01

Intrinsically interfacially active proteins have garnered considerable interest recently owing to their potential use in a range of materials applications. Notably, the fungal hydrophobins are known to form robust and well-organized surface layers with high mechanical strength. Recently, it was shown that the bacterial biofilm protein BslA also forms highly elastic surface layers at interfaces. Here we describe several self-assembled structures formed by BslA, both at interfaces and in bulk solution, over a range of length scales spanning from nanometres to millimetres. First, we observe transiently stable and highly elongated air bubbles formed in agitated BslA samples. We study their behaviour in a range of solution conditions and hypothesize that their dissipation is a consequence of the slow adsorption kinetics of BslA to an air–water interface. Second, we describe elongated tubules formed by BslA interfacial films when shear stresses are applied in both a Langmuir trough and a rheometer. These structures bear a striking resemblance, although much larger in scale, to the elongated air bubbles formed during agitation. Taken together, this knowledge will better inform the conditions and applications of how BslA can be used in the stabilization of multi-phase materials. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’. PMID:27298433

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Jun; Yang, Dali; Wen, Jianguo

A stable single-site Rh catalyst was formed inside individual channels of three-dimensional dendritic mesoporous silica nanospheres through aminosilane binding. The catalyst demonstrated an excellent activity, stability and recyclability in the reduction of 4-nitrophenol, high regioselectivity in the hydrosilylation of terminal alkyne.

Formation and enhanced biocidal activity of water-dispersable organic nanoparticles

NASA Astrophysics Data System (ADS)

Zhang, Haifei; Wang, Dong; Butler, Rachel; Campbell, Neil L.; Long, James; Tan, Bien; Duncalf, David J.; Foster, Alison J.; Hopkinson, Andrew; Taylor, David; Angus, Doris; Cooper, Andrew I.; Rannard, Steven P.

2008-08-01

Water-insoluble organic compounds are often used in aqueous environments in various pharmaceutical and consumer products. To overcome insolubility, the particles are dispersed in a medium during product formation, but large particles that are formed may affect product performance and safety. Many techniques have been used to produce nanodispersions-dispersions with nanometre-scale dimensions-that have properties similar to solutions. However, making nanodispersions requires complex processing, and it is difficult to achieve stability over long periods. Here we report a generic method for producing organic nanoparticles with a combination of modified emulsion-templating and freeze-drying. The dry powder composites formed using this method are highly porous, stable and form nanodispersions upon simple addition of water. Aqueous nanodispersions of Triclosan (a commercial antimicrobial agent) produced with this approach show greater activity than organic/aqueous solutions of Triclosan.

Separations and Waste Forms Research and Development FY 2013 Accomplishments Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

The Separations and Waste Form Campaign (SWFC) under the U.S. Department of Energy (DOE) Fuel Cycle Research and Development Program (FCRD) is responsible for developing advanced separation and waste form technologies to support the various fuel cycle options defined in the DOE Nuclear Energy Research and Development Roadmap, Report to Congress, April 2010. The fiscal year (FY) 2013 accomplishments report provides a highlight of the results of the research and development (R&D) efforts performed within SWFC in FY 2013. Each section contains a high-level overview of the activities, results, technical point of contact, applicable references, and documents produced during themore » fiscal year. This report briefly outlines campaign management and integration activities, but the intent of the report is to highlight the many technical accomplishments made during FY 2013.« less

Adenylyl cyclase G is activated by an intramolecular osmosensor.

PubMed

Saran, Shweta; Schaap, Pauline

2004-03-01

Adenylyl cyclase G (ACG) is activated by high osmolality and mediates inhibition of spore germination by this stress factor. The catalytic domains of all eukaryote cyclases are active as dimers and dimerization often mediates activation. To investigate the role of dimerization in ACG activation, we coexpressed ACG with an ACG construct that lacked the catalytic domain (ACGDeltacat) and was driven by a UV-inducible promoter. After UV induction of ACGDeltacat, cAMP production by ACG was strongly inhibited, but osmostimulation was not reduced. Size fractionation of native ACG showed that dimers were formed between ACG molecules and between ACG and ACGDeltacat. However, high osmolality did not alter the dimer/monomer ratio. This indicates that ACG activity requires dimerization via a region outside the catalytic domain but that dimer formation does not mediate activation by high osmolality. To establish whether ACG required auxiliary sensors for osmostimulation, we expressed ACG cDNA in a yeast adenylyl cyclase null mutant. In yeast, cAMP production by ACG was similarly activated by high osmolality as in Dictyostelium. This strongly suggests that the ACG osmosensor is intramolecular, which would define ACG as the first characterized primary osmosensor in eukaryotes.

Immune response in mice infected with Candida albicans in the mycelial form.

PubMed

Bibas Bonet de Jorrat, M E; de Valdez, G A; de Petrino, S F; Sirena, A; Perdigón, G

1989-05-01

The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

Low physical activity as a predictor for total and cardiovascular disease mortality in middle-aged men and women in Finland.

PubMed

Barengo, Noël C; Hu, Gang; Lakka, Timo A; Pekkarinen, Heikki; Nissinen, Aulikki; Tuomilehto, Jaakko

2004-12-01

To investigate separately for men and women whether moderate or high leisure time physical activity, occupational physical activity, and commuting activity are associated with a reduced cardiovascular disease (CVD) and all-cause mortality, independent of CVD risk factors and other forms of physical activity. Prospective follow-up of 15,853 men and 16,824 women aged 30-59 years living in eastern and south-western Finland (median follow-up time 20 years). CVD and all-cause mortality were lower (9-21%) in men and women (2-17%) who were moderately or highly physically active during leisure time. Moderate and high levels of occupational physical activity decreased CVD and all-cause mortality by 21-27% in both sexes. Women spending daily 15 min or more in walking or cycling to and from work had a reduced CVD and all-cause mortality before adjustment for occupational and leisure time physical activity. Commuting activity was not associated with CVD or all-cause mortality in men. Moderate and high levels of leisure time and occupational physical activity are associated with a reduced CVD and all-cause mortality among both sexes. Promoting already moderate levels of leisure time and occupational physical activity are essential to prevent premature CVD and all-cause mortality.

Light-patterning of synthetic tissues with single droplet resolution.

PubMed

Booth, Michael J; Restrepo Schild, Vanessa; Box, Stuart J; Bayley, Hagan

2017-08-24

Synthetic tissues can be generated by forming networks of aqueous droplets in lipid-containing oil. Each droplet contains a cell-free expression system and is connected to its neighbor through a lipid bilayer. In the present work, we have demonstrated precise external control of such networks by activating protein expression within single droplets, by using light-activated DNA to encode either a fluorescent or a pore-forming protein. By controlling the extent of activation, synthetic tissues were generated with graded levels of protein expression in patterns of single droplets. Further, we have demonstrated reversible activation within individual compartments in synthetic tissues by turning a fluorescent protein on-and-off. This is the first example of the high-resolution patterning of droplet networks, following their formation. Single-droplet control will be essential to power subsets of compartments within synthetic tissues or to stimulate subsets of cells when synthetic tissues are interfaced with living tissues.

Active-Site Hydration and Water Diffusion in Cytochrome P450cam: A Highly Dynamic Process

PubMed Central

Miao, Yinglong; Baudry, Jerome

2011-01-01

Long-timescale molecular dynamics simulations (300 ns) are performed on both the apo- (i.e., camphor-free) and camphor-bound cytochrome P450cam (CYP101). Water diffusion into and out of the protein active site is observed without biased sampling methods. During the course of the molecular dynamics simulation, an average of 6.4 water molecules is observed in the camphor-binding site of the apo form, compared to zero water molecules in the binding site of the substrate-bound form, in agreement with the number of water molecules observed in crystal structures of the same species. However, as many as 12 water molecules can be present at a given time in the camphor-binding region of the active site in the case of apo-P450cam, revealing a highly dynamic process for hydration of the protein active site, with water molecules exchanging rapidly with the bulk solvent. Water molecules are also found to exchange locations frequently inside the active site, preferentially clustering in regions surrounding the water molecules observed in the crystal structure. Potential-of-mean-force calculations identify thermodynamically favored trans-protein pathways for the diffusion of water molecules between the protein active site and the bulk solvent. Binding of camphor in the active site modifies the free-energy landscape of P450cam channels toward favoring the diffusion of water molecules out of the protein active site. PMID:21943431

I-NERI-2007-004-K, DEVELOPMENT AND CHARACTERIZATION OF NEW HIGH-LEVEL WASTE FORMS FOR ACHIEVING WASTE MINIMIZATION FROM PYROPROCESSING

DOE Office of Scientific and Technical Information (OSTI.GOV)

S.M. Frank

Work describe in this report represents the final year activities for the 3-year International Nuclear Energy Research Initiative (I-NERI) project: Development and Characterization of New High-Level Waste Forms for Achieving Waste Minimization from Pyroprocessing. Used electrorefiner salt that contained actinide chlorides and was highly loaded with surrogate fission products was processed into three candidate waste forms. The first waste form, a high-loaded ceramic waste form is a variant to the CWF produced during the treatment of Experimental Breeder Reactor-II used fuel at the Idaho National Laboratory (INL). The two other waste forms were developed by researchers at the Korean Atomicmore » Energy Research Institute (KAERI). These materials are based on a silica-alumina-phosphate matrix and a zinc/titanium oxide matrix. The proposed waste forms, and the processes to fabricate them, were designed to immobilize spent electrorefiner chloride salts containing alkali, alkaline earth, lanthanide, and halide fission products that accumulate in the salt during the processing of used nuclear fuel. This aspect of the I-NERI project was to demonstrate 'hot cell' fabrication and characterization of the proposed waste forms. The outline of the report includes the processing of the spent electrorefiner salt and the fabrication of each of the three waste forms. Also described is the characterization of the waste forms, and chemical durability testing of the material. While waste form fabrication and sample preparation for characterization must be accomplished in a radiological hot cell facility due to hazardous radioactivity levels, smaller quantities of each waste form were removed from the hot cell to perform various analyses. Characterization included density measurement, elemental analysis, x-ray diffraction, scanning electron microscopy and the Product Consistency Test, which is a leaching method to measure chemical durability. Favorable results from this demonstration project will provide additional options for fission product immobilization and waste management associated the electrochemical/pyrometallurgical processing of used nuclear fuel.« less

Abscisic acid-dependent multisite phosphorylation regulates the activity of a transcription activator AREB1.

PubMed

Furihata, Takashi; Maruyama, Kyonoshin; Fujita, Yasunari; Umezawa, Taishi; Yoshida, Riichiro; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2006-02-07

bZIP-type transcription factors AREBs/ABFs bind an abscisic acid (ABA)-responsive cis-acting element named ABRE and transactivate downstream gene expression in Arabidopsis. Because AREB1 overexpression could not induce downstream gene expression, activation of AREB1 requires ABA-dependent posttranscriptional modification. We confirmed that ABA activated 42-kDa kinase activity, which, in turn, phosphorylated Ser/Thr residues of R-X-X-S/T sites in the conserved regions of AREB1. Amino acid substitutions of R-X-X-S/T sites to Ala suppressed transactivation activity, and multiple substitution of these sites resulted in almost complete suppression of transactivation activity in transient assays. In contrast, substitution of the Ser/Thr residues to Asp resulted in high transactivation activity without exogenous ABA application. A phosphorylated, transcriptionally active form was achieved by substitution of Ser/Thr in all conserved R-X-X-S/T sites to Asp. Transgenic plants overexpressing the phosphorylated active form of AREB1 expressed many ABA-inducible genes, such as RD29B, without ABA treatment. These results indicate that the ABA-dependent multisite phosphorylation of AREB1 regulates its own activation in plants.

Teacher to Student Epistemological Interaction in the Contemporary Paradigm of University Education

ERIC Educational Resources Information Center

Charikova, Irina; Zhadanov, Victor

2017-01-01

The relevance of the problem under study is conditioned by the socially important need of the contemporary university education to train highly qualified personnel in all directions of activity, to form and develop a professional person of a high intellectual, moral and spiritual culture. The objective of the paper consists in giving theoretical…

Creating a Powerful Learning Environment with Networked Mobile Learning Devices

ERIC Educational Resources Information Center

Crawford, Valerie M.

2007-01-01

Highly mobile devices can make important information available to teachers in real-time, anywhere in the classroom, and in the form of easy-to-read graphical displays that support classroom decision making. By supporting such important teaching activities, we can create a high-performance classroom that supports teachers and the art of teaching,…

Monolithic amplifier with stable, high resistance feedback element and method for fabricating the same

DOEpatents

O'Connor, Paul

1998-08-11

A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit.

Skylab experiments. Volume 6: Mechanics. [Skylab program accomplishments for high school level education

NASA Technical Reports Server (NTRS)

1973-01-01

Skylab program activities are presented in a form adapted to instruction of high school students. The overall goals of the program are discussed. The specific accomplishments of the mechanics investigations are described. The subjects involved are as follows: (1) evaluation of mobility aids, (2) mass measurement devices, and (3) space guidance crew/vehicle disturbances.

Creative Writing for the Verbally Gifted: Senior High.

ERIC Educational Resources Information Center

Boesen, Steve

The guide presents information on a creative writing course for verbally gifted senior high school students. Part I of the course consists of general exploration activities on literary forms: the journal, the poem, the short story, and a student selection from among such types as one-act plays, essays or by-lined articles, editorials, and TV (or…

Gullies on Mars: Origin by Snow and Ice Melting and Potential for Life Based on Possible Analogs from Devon Island, High Arctic

NASA Technical Reports Server (NTRS)

Lee, Pascal; Cockell, Charles S.; McKay, Christopher P.

2004-01-01

Gullies on Devon Island, High Arctic, which form by melting of transient surface ice and snow covers and offer morphologic and contextual analogs for gullies reported on Mars are reported to display enhancements in biological activity in contrast to surrounding polar desert terrain.

Cooperative binding mitigates the high-dose hook effect.

PubMed

Roy, Ranjita Dutta; Rosenmund, Christian; Stefan, Melanie I

2017-08-14

The high-dose hook effect (also called prozone effect) refers to the observation that if a multivalent protein acts as a linker between two parts of a protein complex, then increasing the amount of linker protein in the mixture does not always increase the amount of fully formed complex. On the contrary, at a high enough concentration range the amount of fully formed complex actually decreases. It has been observed that allosterically regulated proteins seem less susceptible to this effect. The aim of this study was two-fold: First, to investigate the mathematical basis of how allostery mitigates the prozone effect. And second, to explore the consequences of allostery and the high-dose hook effect using the example of calmodulin, a calcium-sensing protein that regulates the switch between long-term potentiation and long-term depression in neurons. We use a combinatorial model of a "perfect linker protein" (with infinite binding affinity) to mathematically describe the hook effect and its behaviour under allosteric conditions. We show that allosteric regulation does indeed mitigate the high-dose hook effect. We then turn to calmodulin as a real-life example of an allosteric protein. Using kinetic simulations, we show that calmodulin is indeed subject to a hook effect. We also show that this effect is stronger in the presence of the allosteric activator Ca 2+ /calmodulin-dependent kinase II (CaMKII), because it reduces the overall cooperativity of the calcium-calmodulin system. It follows that, surprisingly, there are conditions where increased amounts of allosteric activator actually decrease the activity of a protein. We show that cooperative binding can indeed act as a protective mechanism against the hook effect. This will have implications in vivo where the extent of cooperativity of a protein can be modulated, for instance, by allosteric activators or inhibitors. This can result in counterintuitive effects of decreased activity with increased concentrations of both the allosteric protein itself and its allosteric activators.

[Active form of vitamin D in overweight and obese pediatric patients in northwest Mexico].

PubMed

Valle-Leal, Jaime; Limón-Armenta, Jasmin; Serrano-Osuna, Ricardo; López-Morales, Cruz Mónica; Alvárez-Bastidas, Lucia

Low levels of vitamin D have been associated with a range of clinical conditions such as obesity, insulin resistance, and diabetes mellitus, among others. There are few studies that measure the active form of vitamin D (1,25 (OH) 2 vitamin D) in obese children. However, published data are inconclusive. The aim of this study was to determine the active levels of vitamin D in obese and overweight children and to find an association between low levels of vitamin D, obesity and impaired glucose metabolism. A cross-sectional, analytical study was conducted in 6 to 12-year-old children with excess adiposity determined by waist-stature index and body mass index. Levels of glucose, insulin, complete lipid profile, homeostatic model assessment and the active form of vitamin D were measured in each patient. Levels < 30 pg/ml were considered as low levels of vitamin D. The prevalence of low levels of active vitamin D was 36%. A significant association between low levels of active vitamin D and high levels of insulin was found. No significant association was found between vitamin levels and adiposity measures. Low levels of active vitamin D were found in 36% of the population studied. A significant association with insulin resistance and hyperinsulinemia was demonstrated. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Anticoagulant activity of marine green and brown algae collected from Jeju Island in Korea.

PubMed

Athukorala, Yasantha; Lee, Ki-Wan; Kim, Se-Kwon; Jeon, You-Jin

2007-07-01

Twenty-two algal species were evaluated for their potential anticoagulant activities. Hot water extracts from selected species, Codium fragile and Sargassum horneri showed high activated partial thromboplastin time (APTT). Ultraflo extract of C. fragile and S. horneri exhibited the most potent anticoagulant activity. Furthermore, in both algal species, active compounds were mainly concentrated in >30kDa faction. The crude polysaccharide fraction (>30kDa; CpoF) of C. fragile composed of approximately 80% carbohydrate and approximately 19% of protein; the crude polysaccharide fraction (>30kDa; CpoF) of S. horneri was composed of 97% of carbohydrate and approximately 2% of protein. Therefore, most probably the active compound, or compounds of the algal species were related to high molecular weight polysaccharide, or a complex form with carbohydrate and protein (proteoglycan).

The Influence of Sintering Method on Kaolin-Based Geopolymer Ceramics with Addition of Ultra High Molecular Weight Polyethylene as Binder

NASA Astrophysics Data System (ADS)

Romisuhani, A.; AlBakri, M. M.; Kamarudin, H.; Andrei, S. V.

2017-11-01

The influence of sintering method on kaolin-based geopolymer ceramics with addition of Ultra High Molecular Weight Polyethylene as binder were studied. Geopolymer were formed at room temperature from kaolin and sodium silicate in a highly alkaline medium, followed by curing and drying at 80 °C. 12 M of sodium hydroxide solution were mixed with sodium silicate at a ratio of 0.24 to form alkaline activator. Powder metallurgy technique were used in order to produce kaolin geopolymer ceramics with addition of Ultra High Molecular Weight Polyethylene. The samples were heated at temperature of 1200 °C with two different sintering method which are conventional method and two-step sintering method. The strength and density were tested.

HOBYS and W43-HERO: Two more steps toward a Galaxy-wide understanding of high-mass star formation

NASA Astrophysics Data System (ADS)

Motte, Frédérique; Bontemps, Sylvain; Tigé, Jérémy

The Herschel/HOBYS key program allows to statistically study the formation of 10-20 M ⊙ stars. The IRAM/W43-HERO large program is itself dedicated to the much more extreme W43 molecular complex, which forms stars up to 50 M ⊙. Both reveal high-density cloud filaments of several pc3, which are forming clusters of OB-type stars. Given their activity, these so-called mini-starburst cloud ridges could be seen as ``miniature and instant models'' of starburst galaxies. Both surveys also strongly suggest that high-mass prestellar cores do not exist, in agreement with the dynamical formation of cloud ridges. The HOBYS and W43 surveys are necessary steps towards Galaxy-wide studies of high-mass star formation.

Influence of the Form of Administration of Chlorogenic Acids on Oxidative Stress Induced by High fat Diet in Rats.

PubMed

Budryn, G; Zaczyńska, D; Żyżelewicz, D; Grzelczyk, J; Zduńczyk, Z; Juśkiewicz, J

2017-06-01

Green coffee is one of health-promoting supplements of the diet, applied in the form of either preparations or enriched food products. Its positive impact is manifested by mitigation of the development of certain tumors, e.g., in the colon and liver, and type 2 diabetes. Many studies proved that chlorogenic acids are the main active substances in green coffee. The bioavailability of these compounds depends among others on their interactions with other components of the diet, mainly proteins. When they are used as food ingredients, their bioavailability is additionally decreased because of the decomposition or interactions with other ingredients during food processing. The undesirable changes may be limited among others by microencapsulation, for example with β-cyclodextrin. In this study, rats were fed the pro-oxidative high fat diet, which was supplemented with chlorogenic acids from green coffee that were used in four forms such as: a purified extract, complexes of chlorogenic acids and β-cyclodextrin, and bread supplemented with either the extract or the β-cyclodextrin inclusion complex. Chlorogenic acids added to bread because of the reduced absorption from the crumb in the small intestine and increased passage to the colon, contributed to the beneficial modification of enzymatic activities of intestinal microbiota. When added directly to the diet, they contributed to the improved antioxidant status in the liver and kidneys, lowered glucose level and increased HDL level. A high ratio of reduced to oxidized glutathione in the liver and a high concentration of antioxidants in the blood serum were observed after administration of chlorogenic acids in the form of inclusion complexes with β-cyclodextrin, indicating that microencapsulation increased their bioaccessibility due to the limited interactions with other components of the diet.

Pharmacokinetics of loxoprofen and its active metabolite after dermal application of loxoprofen gel to rats.

PubMed

Sawamura, R; Kazui, M; Kurihara, A; Izumi, T

2015-02-01

This study was conducted to evaluate the pharmacokinetics of loxoprofen (LX) and its active metabolite (trans-OH form) after a single dermal application of LX gel (LX-G) to rats. In the skin at the treated site, generation of the trans-OH form was detected and both LX and the trans-OH form remained at high concentrations for 24 h after dermal application. Furthermore, both LX and the trans-OH form also remained in the skeletal muscle over 24 h after the single dermal application, while they eliminated rapidly after the single oral administration. The area under the curve up to the last measurable point (AUC(0-t)) for plasma concentrations of LX or the trans-OH form after dermal application of LX-G was less than 11% of that after oral administration of LX. In addition, C(max) and AUC(0-t) increased in a saturable manner while increasing the dose. Overall, these results demonstrated that the trans-OH form was generated at the treated site with the process of dermal absorption of LX and it remained at the target site for a long period with low systemic exposure compared to oral administration.

On the Theory of High-Power Ultrashort Pulse Propagation in Raman-Active Media

NASA Technical Reports Server (NTRS)

Belenov, E. M.; Isakov, V. A.; Kanavin, A. P.; Smetanin, I. V.

1996-01-01

The propagation of an intense femtosecond pulse in a Raman-active medium is analyzed. An analytic solution which describes in explicit form the evolution of the light pulse is derived. The field of an intense light wave undergoes a substantial transformation as the wave propagates through the medium. The nature of this transformation can change over time scales comparable to the period of the optical oscillations. As a result, the pulse of sufficiently high energy divides into stretched and compressed domains where the field decreases and increases respectively.

Yeast Sub1 and human PC4 are G-quadruplex binding proteins that suppress genome instability at co-transcriptionally formed G4 DNA.

PubMed

Lopez, Christopher R; Singh, Shivani; Hambarde, Shashank; Griffin, Wezley C; Gao, Jun; Chib, Shubeena; Yu, Yang; Ira, Grzegorz; Raney, Kevin D; Kim, Nayun

2017-06-02

G-quadruplex or G4 DNA is a non-B secondary DNA structure consisting of a stacked array of guanine-quartets that can disrupt critical cellular functions such as replication and transcription. When sequences that can adopt Non-B structures including G4 DNA are located within actively transcribed genes, the reshaping of DNA topology necessary for transcription process stimulates secondary structure-formation thereby amplifying the potential for genome instability. Using a reporter assay designed to study G4-induced recombination in the context of an actively transcribed locus in Saccharomyces cerevisiae, we tested whether co-transcriptional activator Sub1, recently identified as a G4-binding factor, contributes to genome maintenance at G4-forming sequences. Our data indicate that, upon Sub1-disruption, genome instability linked to co-transcriptionally formed G4 DNA in Top1-deficient cells is significantly augmented and that its highly conserved DNA binding domain or the human homolog PC4 is sufficient to suppress G4-associated genome instability. We also show that Sub1 interacts specifically with co-transcriptionally formed G4 DNA in vivo and that yeast cells become highly sensitivity to G4-stabilizing chemical ligands by the loss of Sub1. Finally, we demonstrate the physical and genetic interaction of Sub1 with the G4-resolving helicase Pif1, suggesting a possible mechanism by which Sub1 suppresses instability at G4 DNA. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Electrically pumped edge-emitting photonic bandgap semiconductor laser

DOEpatents

Lin, Shawn-Yu; Zubrzycki, Walter J.

2004-01-06

A highly efficient, electrically pumped edge-emitting semiconductor laser based on a one- or two-dimensional photonic bandgap (PBG) structure is described. The laser optical cavity is formed using a pair of PBG mirrors operating in the photonic band gap regime. Transverse confinement is achieved by surrounding an active semiconductor layer of high refractive index with lower-index cladding layers. The cladding layers can be electrically insulating in the passive PBG mirror and waveguide regions with a small conducting aperture for efficient channeling of the injection pump current into the active region. The active layer can comprise a quantum well structure. The quantum well structure can be relaxed in the passive regions to provide efficient extraction of laser light from the active region.

Tailoring Enzyme-Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress.

PubMed

Liu, Ching-Ping; Wu, Te-Haw; Lin, Yu-Lung; Liu, Chia-Yeh; Wang, Sabrina; Lin, Shu-Yi

2016-08-01

The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase-like activity can decompose hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating-mediated enzyme-like activities. Herein, it is reported for the first time that amine-terminated PAMAM dendrimer-entrapped gold nanoclusters (AuNCs-NH2 ) unexpectedly lose their peroxidase-like activity while still retaining their catalase-like activity in physiological conditions. Surprisingly, the methylated form of AuNCs-NH2 (i.e., MAuNCs-N(+) R3 , where R = H or CH3 ) results in a dramatic recovery of the intrinsic peroxidase-like activity while blocking most primary and tertiary amines (1°- and 3°-amines) of dendrimers to form quaternary ammonium ions (4°-amines). However, the hidden peroxidase-like activity is also found in hydroxyl-terminated dendrimer-encapsulated AuNCs (AuNCs-OH, inside backbone with 3°-amines), indicating that 3°-amines are dominant in mediating the peroxidase-like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°-amines on the surface of dendrimer-encapsulated AuNCs provides sufficient suppression of the critical mediator •OH for the peroxidase-like activity. Finally, it is demonstrated that AuNCs-NH2 with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterisation of phenol oxidase and peroxidase from maize silk.

PubMed

Sukalović, V Hadzi-Tasković; Veljović-Jovanović, S; Maksimović, J Dragisić; Maksimović, V; Pajić, Z

2010-05-01

Silk of some maize genotypes contains a high level of phenolics that undergo enzymatic oxidation to form quinones, which condense among themselves or with proteins to form brown pigments. Two phenolic oxidizing enzymes, peroxidase (POD; EC 1.11.1.7) and polyphenol oxidase (PPO; EC 1.10.3.1), from maize (Zea mays L.) silk were characterised with respect to their preferred substrate, different isoforms and specific effectors. One browning silk sample with high, and two non-browning samples with low phenolic content were investigated. Although POD oxidizes a wide range of phenolic substrates in vitro, its activity rate was independent of silk phenolic content. PPO activity, detected with o-diphenolic substrates, was abundant only in browning silk, and low or absent in non-browning silk. Pollination increased POD but not PPO activity. Isoelectric-focusing (IEF) and specific staining for POD and PPO showed a high degree of polymorphism that varied with silk origin. The IEF pattern of POD revealed a number of anionic and several cationic isoenzymes, with the most pronounced having neutral pI 7 and a basic isoform with pI 10. Detected isoforms of PPO were anionic, except for one neutral form found only in browning silk, and occupied positions different from those of POD. Different inhibitory effects of NaN(3), EDTA, KCN, and L-cysteine, as well as different impacts of a variety of cations on the oxidation of chlorogenic acid, mediated by PPO or POD, were detected. The findings are discussed in terms of a possible roles of these enzymes in defence and pollination.

Thrombus Formation at High Shear Rates.

PubMed

Casa, Lauren D C; Ku, David N

2017-06-21

The final common pathway in myocardial infarction and ischemic stroke is occlusion of blood flow from a thrombus forming under high shear rates in arteries. A high-shear thrombus forms rapidly and is distinct from the slow formation of coagulation that occurs in stagnant blood. Thrombosis at high shear rates depends primarily on the long protein von Willebrand factor (vWF) and platelets, with hemodynamics playing an important role in each stage of thrombus formation, including vWF binding, platelet adhesion, platelet activation, and rapid thrombus growth. The prediction of high-shear thrombosis is a major area of biofluid mechanics in which point-of-care testing and computational modeling are promising future directions for clinically relevant research. Further research in this area will enable identification of patients at high risk for arterial thrombosis, improve prevention and treatment based on shear-dependent biological mechanisms, and improve blood-contacting device design to reduce thrombosis risk.

Corrosion resistant positive electrode for high-temperature, secondary electrochemical cell

DOEpatents

Otto, Neil C.; Warner, Barry T.; Smaga, John A.; Battles, James E.

1983-01-01

The corrosion rate of low carbon steel within a positive electrode of a high-temperature, secondary electrochemical cell that includes FeS as active material is substantially reduced by incorporating therein finely divided iron powder in stoichiometric excess to the amount required to form FeS in the fully charged electrode. The cell typically includes an alkali metal or alkaline earth metal as negative electrode active material and a molten metal halide salt as electrolyte. The excess iron permits use of inexpensive carbon steel alloys that are substantially free of the costly corrosion resistant elements chromium, nickel and molybdenum while avoiding shorten cell life resulting from high corrosion rates.

Corrosion resistant positive electrode for high-temperature, secondary electrochemical cell

DOEpatents

Otto, N.C.; Warner, B.T.; Smaga, J.A.; Battles, J.E.

1982-07-07

The corrosion rate of low carbon steel within a positive electrode of a high-temperature, secondary electrochemical cell that includes FeS as active material is substantially reduced by incorporating therein finely divided iron powder in stoichiometric excess to the amount required to form FeS in the fully charged electrode. The cell typically includes an alkali metal or alkaline earth metal as negative electrode active material and a molten metal halide salt as electrolyte. The excess iron permits use of inexpensive carbon steel alloys that are substantially free of the costly corrosion resistant elements chromium, nickel and molybdenum while avoiding shorten cell life resulting from high corrosion rates.

STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES

PubMed Central

Avery, Oswald T.; MacLeod, Colin M.; McCarty, Maclyn

1944-01-01

1. From Type III pneumococci a biologically active fraction has been isolated in highly purified form which in exceedingly minute amounts is capable under appropriate cultural conditions of inducing the transformation of unencapsulated R variants of Pneumococcus Type II into fully encapsulated cells of the same specific type as that of the heat-killed microorganisms from which the inducing material was recovered. 2. Methods for the isolation and purification of the active transforming material are described. 3. The data obtained by chemical, enzymatic, and serological analyses together with the results of preliminary studies by electrophoresis, ultracentrifugation, and ultraviolet spectroscopy indicate that, within the limits of the methods, the active fraction contains no demonstrable protein, unbound lipid, or serologically reactive polysaccharide and consists principally, if not solely, of a highly polymerized, viscous form of desoxyribonucleic acid. 4. Evidence is presented that the chemically induced alterations in cellular structure and function are predictable, type-specific, and transmissible in series. The various hypotheses that have been advanced concerning the nature of these changes are reviewed. PMID:19871359

Silica-Protection-Assisted Encapsulation of Cu2 O Nanocubes into a Metal-Organic Framework (ZIF-8) To Provide a Composite Catalyst.

PubMed

Li, Bo; Ma, Jian-Gong; Cheng, Peng

2018-06-04

The integration of metal/metal oxide nanoparticles (NPs) into metal-organic frameworks (MOFs) to form composite materials has attracted great interest due to the broad range of applications. However, to date, it has not been possible to encapsulate metastable NPs with high catalytic activity into MOFs, due to their instability during the preparation process. For the first time, we have successfully developed a template protection-sacrifice (TPS) method to encapsulate metastable NPs such as Cu 2 O into MOFs. SiO 2 was used as both a protective shell for Cu 2 O nanocubes and a sacrificial template for forming a yolk-shell structure. The obtained Cu 2 O@ZIF-8 composite exhibits excellent cycle stability in the catalytic hydrogenation of 4-nitrophenol with high activity. This is the first report of a Cu 2 O@MOF-type composite material. The TPS method provides an efficient strategy for encapsulating unstable active metal/metal oxide NPs into MOFs or maybe other porous materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Highly Toxic Cellular Prion Protein Induces a Novel, Nonapoptotic Form of Neuronal Death

PubMed Central

Christensen, Heather M.; Dikranian, Krikor; Li, Aimin; Baysac, Kathleen C.; Walls, Ken C.; Olney, John W.; Roth, Kevin A.; Harris, David A.

2010-01-01

Several different deletions within the N-terminal tail of the prion protein (PrP) induce massive neuronal death when expressed in transgenic mice. This toxicity is dose-dependently suppressed by coexpression of full-length PrP, suggesting that it results from subversion of a normal physiological activity of cellular PrP. We performed a combined biochemical and morphological analysis of Tg(ΔCR) mice, which express PrP carrying a 21-aa deletion (residues 105-125) within a highly conserved region of the protein. Death of cerebellar granule neurons in Tg(ΔCR) mice is not accompanied by activation of either caspase-3 or caspase-8 or by increased levels of the autophagy marker, LC3-II. In electron micrographs, degenerating granule neurons displayed a unique morphology characterized by heterogeneous condensation of the nuclear matrix without formation of discrete chromatin masses typical of neuronal apoptosis. Our data demonstrate that perturbations in PrP functional activity induce a novel, nonapoptotic, nonautophagic form of neuronal death whose morphological features are reminiscent of those associated with excitotoxic stress. PMID:20472884

Active sites of two orthologous cytochromes P450 2E1: Differences revealed by spectroscopic methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anzenbacherova, Eva; Hudecek, Jiri; Murgida, Daniel

2005-12-09

Cytochromes P450 2E1 of human and minipig origin were examined by absorption spectroscopy under high hydrostatic pressure and by resonance Raman spectroscopy. Human enzyme tends to denature to the P420 form more easily than the minipig form; moreover, the apparent compressibility of the heme active site (as judged from a redshift of the absorption maximum with pressure) is greater than that of the minipig counterpart. Relative compactness of the minipig enzyme is also seen in the Raman spectra, where the presence of planar heme conformation was inferred from band positions characteristic of the low-spin heme with high degree of symmetry.more » In this respect, the CYP2E1 seems to be another example of P450 conformational heterogeneity as shown, e.g., by Davydov et al. for CYP3A4 [Biochem. Biophys. Res. Commun. 312 (2003) 121-130]. The results indicate that the flexibility of the CYP active site is likely one of its basic structural characteristics.« less

Fiber Optic Chemical Sensors

DTIC Science & Technology

1993-10-01

patent rights. A major problem was identification of the property of ST&E vs LLNL ST&E was formed to manage the activities of Dr. Hirschfeld and Dr...positions of the fields defined in a fixed format to allow its importation into file management programs both in the microcomputer and the minicomputer...Systems Inc., Perry, Florida. askSam is a free-form information manager . A few basic elements of structure can be used to create a highly structured

Rhenium(VII) Catalysis of Prins Cyclization Reactions

PubMed Central

Tadpetch, Kwanruthai; Rychnovsky, Scott D.

2009-01-01

The rhenium(VII) complex O3ReOSiPh3 are particularly effective catalyst for Prins cyclizations using aromatic and α,β-unsaturated aldehydes. The reaction conditions are mild and the highly substituted 4-hydroxy tetrahydropyran products are formed stereoselectively. Rhenium(VII) complexes appear to spontaneously form esters with alcohols and to directly activate electron rich alcohols for solvolysis. Re2O7 and perrhenic acid were equally effective in catalyzing these cyclizations. PMID:18816133

H2S mediated thermal and photochemical methane activation

PubMed Central

Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric

2013-01-01

Sustainable, low temperature methods of natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) in mixture with methane, CH4, altogether deemed as sub-quality or “sour” gas. We propose a unique method for activating this “sour” gas to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3, and an energy carrier, such as H2. For this purpose, we computationally investigated H2S mediated methane activation to form a reactive CH3SH species via direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4+H2S complex results in a barrier-less relaxation via a conical intersection to form a ground state CH3SH+H2 complex. The resulting CH3SH can further be heterogeneously coupled over acidic catalysts to form higher hydrocarbons while the H2 can be used as a fuel. This process is very different from a conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced controllability over the process conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the currently industrially used methane steam reforming (SMR). PMID:24150813

Contribution of TMEM16F to pyroptotic cell death.

PubMed

Ousingsawat, Jiraporn; Wanitchakool, Podchanart; Schreiber, Rainer; Kunzelmann, Karl

2018-02-20

Pyroptosis is a highly inflammatory form of programmed cell death that is caused by infection with intracellular pathogens and activation of canonical or noncanonical inflammasomes. The purinergic receptor P2X 7 is activated by the noncanonical inflammasome and contributes essentially to pyroptotic cell death. The Ca 2+ activated phospholipid scramblase and ion channel TMEM16F has been shown earlier to control cellular effects downstream of purinergic P2X 7 receptors that ultimately lead to cell death. As pyroptotic cell death is accompanied by an increases in intracellular Ca 2+ , we asked whether TMEM16F is activated during pyroptosis. The N-terminal cleavage product of gasdermin D (GD-N) is an executioner of pyroptosis by forming large plasma membrane pores. Expression of GD-N enhanced basal Ca 2+ levels and induced cell death. We observed that GD-N induced cell death in HEK293 and HAP1 cells, which was depending on expression of endogenous TMEM16F. GD-N activated large whole cell currents that were suppressed by knockdown or inhibition of TMEM16F. The results suggest that whole cell currents induced by the pore forming domain of gasdermin-D, are at least in part due to activation of TMEM16F. Knockdown of other TMEM16 paralogues expressed in HAP1 cells suggest TMEM16F as a crucial element during pyroptosis and excluded a role of other TMEM16 proteins. Thus TMEM16F supports pyroptosis and other forms of inflammatory cell death such as ferroptosis. Its potent inhibition by tannic acid may be part of the anti-inflammatory effects of flavonoids.

Catalytic decomposition of toxic chemicals over iron group metals supported on carbon nanotubes.

PubMed

Li, Lili; Chen, Can; Chen, Long; Zhu, Zixue; Hu, Jianli

2014-03-18

This study explores catalytic decomposition of phosphine (PH3) using iron group metals (Co, Ni) and metal oxides (Fe2O3, Co(3)O4, NiO) supported on carbon nanotubes (CNTs). The catalysts are synthesized by means of a deposition-precipitation method. The morphology, structure, and composition of the catalysts are characterized using a number of analytical instrumentations, including high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, BET surface area measurement, and inductively coupled plasma. The activity of the catalysts in the PH3 decomposition reaction is measured and correlated with their surface and structural properties. The characterization results show that phosphidation occurs on the catalyst surface, and the resulting metal phosphides act as an active phase in the PH3 decomposition reaction. Cobalt phosphide, CoP, is formed on Co/CNTs and Co(3)O4/CNTs, whereas iron phosphide, FeP, is formed on Fe2O3/CNTs. In contrast, phosphorus-rich phosphide NiP2 is formed on Ni/CNTs and NiO/CNTs. The initial activities of the catalysts are shown in the following sequence: Ni/CNTs > Co/CNTs > Co(3)O4/CNTs >NiO/CNTs > Fe2O3/CNTs, whereas activities of metal phosphides are shown in the following order: CoP > NiP2 > FeP. The catalytic activity of metal phosphides is attributed to their electronic properties. Cobalt phosphide formed on Co/CNTs and Co(3)O4/CNTs exhibits not only the highest activity, but also long-term stability in the PH3 decomposition reaction.

The Evolution of Active Regions

NASA Astrophysics Data System (ADS)

Green, Lucie

2016-10-01

The solar corona is a highly dynamic environment which exhibits the largest releases of energy in the Solar System in the form of solar flares and coronal mass ejections. This activity predominantly originates from active regions, which store and release free magnetic energy and dominate the magnetic face of the Sun. Active regions can be long-lived features, being affected by the Sun's convective flows, differential rotation and meridional flows. The Sun's global coronal field can be seen as the superposed growth and subsequent diffusion of all previously formed active regions. This talk will look at active regions as an observable product of the solar dynamo and will discuss the physical processes that are at play which lead to the storage and release of free magnetic energy. What happens to flux that emerges into the corona so that it goes down an evolutionary path that leads to dynamic activity? And how does this activity vary with active region age? When an active region reaches the end of its lifetime, his much of the magnetic flux is recycled back into subsequent solar cycles? The current status of observations and modelling will be reviewed with a look to the future and fundamental questions that are still be be answered.

Sky Sculpture.

ERIC Educational Resources Information Center

Woody, Howard

1980-01-01

Described is a five-day workshop in the new environmental art form of sky sculpture, which was presented at Wingfield High School in Jackson, Mississippi. Included are daily activities and the design considerations faced by students when planning their balloon creations for flight. (SJL)

Highly stable ceria-zirconia-yttria supported Ni catalysts for syngas production by CO2 reforming of methane

NASA Astrophysics Data System (ADS)

Muñoz, M. A.; Calvino, J. J.; Rodríguez-Izquierdo, J. M.; Blanco, G.; Arias, D. C.; Pérez-Omil, J. A.; Hernández-Garrido, J. C.; González-Leal, J. M.; Cauqui, M. A.; Yeste, M. P.

2017-12-01

Ni/CeO2/YSZ and Ni/Ce0.15Zr0.85O2 have been investigated as catalysts for the dry reforming of methane at 750 °C. Ni was incorporated by the impregnation method. The supports were previously activated by using a thermo-chemical protocol consisting on a severe reduction (H2/Ar) at 950 °C followed by a mild oxidation (O2/He) at 500 °C. According to TPR results, this protocol leads to the development of unique redox properties in the case of the CeO2/YSZ oxide. Two types of CO2 + CH4 (1:1) mixtures (helium-diluted and undiluted) were used to feed the reactor. When using the Ni/Ce0.15Zr0.85O2 catalyst with undiluted feed, the reactor became plugged by coke. By contrast, Ni/CeO2/YSZ behaved as an active and stable catalyst even under the most severe operation conditions. The characterization of the spent Ni/CeO2/YSZ using TGA, TEM, Raman and XPS spectroscopy revealed that only a limited amount of graphitic carbon, in form of nanotubes, was formed. No evidences of deactivating carbonaceous forms were obtained. The singular redox properties of the activated CeO2/YSZ oxides are proposed as a key for designing Ni catalysts highly stable in reforming processes.

X-ray powder diffractometry of intact film coated tablets--an approach to monitor the physical form of the active pharmaceutical ingredient during processing and storage.

PubMed

Yamada, Hiroyuki; Suryanarayanan, Raj

2007-08-01

The antiviral compound, 2-amino-6-(4-methoxyphenylthio)-9-[2-(phosphonomethoxy)ethyl]purine bis(2,2,2-trifluoroethyl)ester (MCC-478), can exist in several anhydrous polymorphic forms and also as a hemihydrate. The XRD patterns of the tablets, containing each form of the active pharmaceutical ingredient (API), revealed at least one peak unique to each form. A semiquantitative microdiffractometric method was developed to nondestructively characterize the physical form of the API in intact film-coated tablets. This was accomplished even though the weight fraction of the API was <0.2 and that of mannitol, a highly crystalline excipient, was approximately 0.6. The method was used to determine the effect of aqueous film-coating process on the physical form of the API. The final dosage form was also monitored following storage at 40 degrees C/75% RH for 6 months. There was no phase transformation of the API either due to the film-coating process or following accelerated storage. This technique has potential utility not only for process control during manufacture, but also for the quality control of the final product. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

Spatial-temporal patterns of retinal waves underlying activity-dependent refinement of retinofugal projections.

PubMed

Stafford, Ben K; Sher, Alexander; Litke, Alan M; Feldheim, David A

2009-10-29

During development, retinal axons project coarsely within their visual targets before refining to form organized synaptic connections. Spontaneous retinal activity, in the form of acetylcholine-driven retinal waves, is proposed to be necessary for establishing these projection patterns. In particular, both axonal terminations of retinal ganglion cells (RGCs) and the size of receptive fields of target neurons are larger in mice that lack the beta2 subunit of the nicotinic acetylcholine receptor (beta2KO). Here, using a large-scale, high-density multielectrode array to record activity from hundreds of RGCs simultaneously, we present analysis of early postnatal retinal activity from both wild-type (WT) and beta2KO retinas. We find that beta2KO retinas have correlated patterns of activity, but many aspects of these patterns differ from those of WT retina. Quantitative analysis suggests that wave directionality, coupled with short-range correlated bursting patterns of RGCs, work together to refine retinofugal projections.

A 12 years brazilian space education activity experience

NASA Astrophysics Data System (ADS)

Stancato, Fernando; Gustavo Catalani Racca, João; Ballarotti, MaurícioG.

2001-03-01

A multidisciplinary group of students from the university and latter also from the high school was formed in 1988 with the objective to make them put in practice their knowledge in physics, chemistry and mathematics and engineering fields in experimental rocketry. The group was called "Grupo de Foguetes Experimentais", GFE. Since that time more than 150 students passed throw the group and now many of them are in the space arena. The benefits for students in a space hands-on project are many: More interest in their school subjects is gotten as they see an application for them; Interrelation attitudes are learned as space projects is a team activity; Responsibility is gained as each is responsible for a part of a critical mission project; Multidisciplinary and international experience is gotten as these are space project characteristics; Learn how to work in a high stress environment as use to be a project launch. This paper will cover the educational experiences gotten during these years and how some structured groups work. It is explained the objectives and how the group was formed. The group structure and the different phases that at each year the new team passes are described. It is shown the different activities that the group uses to do from scientific seminars, scientific club and international meetings to technical tours and assistance to rocket activities in regional schools. It is also explained the group outreach activities as some launches were covered by the media in more then 6 articles in newspaper and 7 television news. In 1999 as formed an official group called NATA, Núcleo de Atividades Aerospaciais within the Universidade Estadual de Londrina, UEL, by some GFE members and teachers from university. It is explained the first group project results.

Characterization and purification of bile salt hydrolase from Lactobacillus sp. strain 100-100

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lundeen, S.G.; Savage, D.C.

1990-08-01

The authors have characterized and purified the bile salt hydrolase from Lactobacillus sp. strain 100-100. Bile salt hydrolase from cells of the strain was purified with column and high-performance liquid chromatography. The activity was assayed in whole cells and cell-free extracts with either a radiochemical assay involving ({sup 14}C)taurocholic acid or a nonradioactive assay involving trinitrobenzene sulfonate. The activity was detectable only in stationary-phase cells. Within 20 min after conjugated bile acids were added to stationary-phase cultures of strain 100-100, the activity in whole cells increased to levels three- to fivefold higher than in cells from cultures grown in mediummore » free of bile salts. In cell-free extracts, however, the activity was about equal whether or not the cells have been grown with bile salts present. When supernatant solutions from cultures grown in medium containing taurocholic acid were used to suspend cells grown in medium free of the bile salt, the bile salt hydrolase activity detected in whole cells increased two- to threefold. Two forms of the hydrolase were purified from the cells and designated hydrolases A and B. They eluted from anion-exchange high-performance liquid chromatography in two sets of fractions, A at 0.15 M NaCl and B at 0.18 M NaCl. Their apparent molecular weights in nondenaturing polyacrylamide gel electrophoresis were 115,000 and 105,000, respectively. However, discrepancies existed in the apparent molecular weights and number of peptides detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the two forms. Whether the enzyme exists in two forms in the cells remains to be determined.« less

The nanoscale spatial organization of B-cell receptors on immunoglobulin M- and G-expressing human B-cells.

PubMed

Lee, Jinmin; Sengupta, Prabuddha; Brzostowski, Joseph; Lippincott-Schwartz, Jennifer; Pierce, Susan K

2017-02-15

B-cell activation is initiated by the binding of antigen to the B-cell receptor (BCR). Here we used dSTORM superresolution imaging to characterize the nanoscale spatial organization of immunoglobulin M (IgM) and IgG BCRs on the surfaces of resting and antigen--activated human peripheral blood B-cells. We provide insights into both the fundamental process of antigen-driven BCR clustering and differences in the spatial organization of IgM and IgG BCRs that may contribute to the characteristic differences in the responses of naive and memory B-cells to antigen. We provide evidence that although both IgM and IgG BCRs reside in highly heterogeneous protein islands that vary in size and number of BCR single-molecule localizations, both resting and activated B-cells intrinsically maintain a high -frequency of single isolated BCR localizations, which likely represent BCR monomers. IgG BCRs are more clustered than IgM BCRs on resting cells and form larger protein islands after antigen activation. Small, dense BCR clusters likely formed via protein-protein interactions are present on the surface of resting cells, and antigen activation induces these to come together to form less dense, larger islands, a process likely governed, at least in part, by protein-lipid interactions. © 2017 Lee, Sengupta, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Biofilm-forming activity of bacteria isolated from toilet bowl biofilms and the bactericidal activity of disinfectants against the isolates.

PubMed

Mori, Miho; Gomi, Mitsuhiro; Matsumune, Norihiko; Niizeki, Kazuma; Sakagami, Yoshikazu

2013-01-01

To evaluate the sanitary conditions of toilets, the bacterial counts of the toilet bowl biofilms in 5 Kansai area and 11 Kansai and Kanto area homes in Japan were measured in winter and summer seasons, respectively. Isolates (128 strains) were identified by analyzing 16S ribosomal RNA sequences. The number of colonies and bacterial species from biofilms sampled in winter tended to be higher and lower, respectively, than those in summer. Moreover, the composition of bacterial communities in summer and winter samples differed considerably. In summer samples, biofilms in Kansai and Kanto areas were dominated by Blastomonas sp. and Mycobacterium sp., respectively. Methylobacterium sp. was detected in all toilet bowl biofilms except for one sample. Methylobacterium sp. constituted the major presence in biofilms along with Brevundimonas sp., Sphingomonas sp., and/or Pseudomonas sp. The composition ratio of the sum of their genera was 88.0 from 42.9% of the total bacterial flora. The biofilm formation abilities of 128 isolates were investigated, and results suggested that Methylobacterium sp. and Sphingomonas sp. were involved in biofilm formation in toilet bowls. The biofilm formation of a mixed bacteria system that included bacteria with the highest biofilm-forming ability in a winter sample was greater than mixture without such bacteria. This result suggests that isolates possessing a high biofilm-forming activity are involved in the biofilm formation in the actual toilet bowl. A bactericidal test against 25 strains indicated that the bactericidal activities of didecyldimethylammonium chloride (DDAC) tended to be higher than those of polyhexamethylene biguanide (PHMB) and N-benzyl-N,N-dimethyldodecylammonium chloride (ADBAC). In particular, DDAC showed high bactericidal activity against approximately 90% of tested strains under the 5 h treatment.

Oxidative metabolism of 1-nitropyrene by rabbit liver microsomes and purified microsomal cytochrome P-450 isozymes.

PubMed

Howard, P C; Reed, K A; Koop, D R

1988-08-01

Rabbit liver (male) microsomal metabolism of 10 microM [4,5,9,10-3H]-1-nitropyrene (1NP) was investigated. The total metabolism was not appreciably different with rates of 4.44 +/- 0.45, 3.98 +/- 0.19, 3.90 +/- 0.16, and 3.75 +/- 0.27 nmol/min/mg protein, respectively, for microsomes from phenobarbital, Aroclor-1254, ethanol-treated, and untreated rabbits. However, a more noticeable difference was found in the formation of specific metabolites. Phenobarbital treatment induced changes which favored 1-nitropyrene-3-ol formation, and Aroclor-1254 and ethanol-induced changes which favored 1-nitropyren-6-ol and 1-nitropyren-8-ol formation. 1NP was incubated with untreated microsomes and alpha-naphthoflavone, an inhibitor of rabbit cytochrome P-450 form 6 at low concentrations (less than 1 microM), and an activator of form 3c at high concentrations. The presence of alpha-naphthoflavone changed the profile of metabolites while not affecting the total metabolism. Using purified isozymes of rabbit P-450, we found the constitutive form 3b metabolized 1NP at the highest rate with a catalytic activity of 26.8 nmol/min/nmol P-450. Forms 2 and 6 exhibited rates of 2 and 2.2 nmol/min/nmol P-450. Forms 3a, 3c, and 4 had rates about 50- to 300-fold lower than form 3b. High performance liquid chromatography was used to identify the metabolites when the incubations were carried out in the presence of purified rabbit epoxide hydrolase. With form 6, 54% of the metabolites were accounted for as 1-nitropyren-3-ol, while with form 3b, 73% of the metabolites were 1-nitropyren-6-ol and 1-nitropyren-8-ol. The K-region dihydrodiols were formed by forms 2 and 3b, but not by forms 3c or 6. These results demonstrate that 1NP is a preferential substrate for form 3b, and that a preponderance of the metabolism with untreated rabbit liver microsomes can be attributed to this isozyme.

Penrose photoproduction processes - A high efficiency energy mechanism for active galactic nuclei and quasars

NASA Technical Reports Server (NTRS)

Leiter, D.; Kafatos, M.

1979-01-01

Recent observations of NGC 4151 and 3C273 suggest that the nuclei of active galaxies have very high gamma ray efficiencies. In addition, optical studies of M87 have indicated the possibility of a massive black hole in its central region. The above facts have led to study of a new physical mechanism, Penrose Photoproduction Processes, in the ergospheres of massive Kerr black holes, as a way to account for the fluctuating, high efficiency, energy production associated with active galaxies and quasars. Observational signatures, associated with this mechanism, occur in the form of approximately 2 MeV and approximately 2 GeV gamma ray cutoffs which might be corroborated by the observed spectra of NGC 4151 and 3C273, respectively.

Conditional bistability, a generic cellular mnemonic mechanism for robust and flexible working memory computations.

PubMed

Rodriguez, Guillaume; Sarazin, Matthieu; Clemente, Alexandra; Holden, Stephanie; Paz, Jeanne T; Delord, Bruno

2018-04-30

Persistent neural activity, the substrate of working memory, is thought to emerge from synaptic reverberation within recurrent networks. However, reverberation models do not robustly explain fundamental dynamics of persistent activity, including high-spiking irregularity, large intertrial variability, and state transitions. While cellular bistability may contribute to persistent activity, its rigidity appears incompatible with persistent activity labile characteristics. Here, we unravel in a cellular model a form of spike-mediated conditional bistability that is robust, generic and provides a rich repertoire of mnemonic computations. Under asynchronous synaptic inputs of the awakened state, conditional bistability generates spiking/bursting episodes, accounting for the irregularity, variability and state transitions characterizing persistent activity. This mechanism has likely been overlooked because of the sub-threshold input it requires and we predict how to assess it experimentally. Our results suggest a reexamination of the role of intrinsic properties in the collective network dynamics responsible for flexible working memory. SIGNIFICANCE STATEMENT This study unravels a novel form of intrinsic neuronal property, i.e. conditional bistability. We show that, thanks of its conditional character, conditional bistability favors the emergence of flexible and robust forms of persistent activity in PFC neural networks, in opposition to previously studied classical forms of absolute bistability. Specifically, we demonstrate for the first time that conditional bistability 1) is a generic biophysical spike-dependent mechanism of layer V pyramidal neurons in the PFC and that 2) it accounts for essential neurodynamical features for the organisation and flexibility of PFC persistent activity (the large irregularity and intertrial variability of the discharge and its organization under discrete stable states), which remain unexplained in a robust fashion by current models. Copyright © 2018 the authors.

The discovery of stromatolites developing at 3570 m above sea level in a high-altitude volcanic lake Socompa, Argentinean Andes.

PubMed

Farías, María E; Rascovan, Nicolás; Toneatti, Diego M; Albarracín, Virginia H; Flores, María R; Poiré, Daniel G; Collavino, Mónica M; Aguilar, O Mario; Vazquez, Martin P; Polerecky, Lubos

2013-01-01

We describe stromatolites forming at an altitude of 3570 m at the shore of a volcanic lake Socompa, Argentinean Andes. The water at the site of stromatolites formation is alkaline, hypersaline, rich in inorganic nutrients, very rich in arsenic, and warm (20-24°C) due to a hydrothermal input. The stromatolites do not lithify, but form broad, rounded and low-domed bioherms dominated by diatom frustules and aragonite micro-crystals agglutinated by extracellular substances. In comparison to other modern stromatolites, they harbour an atypical microbial community characterized by highly abundant representatives of Deinococcus-Thermus, Rhodobacteraceae, Desulfobacterales and Spirochaetes. Additionally, a high proportion of the sequences that could not be classified at phylum level showed less than 80% identity to the best hit in the NCBI database, suggesting the presence of novel distant lineages. The primary production in the stromatolites is generally high and likely dominated by Microcoleus sp. Through negative phototaxis, the location of these cyanobacteria in the stromatolites is controlled by UV light, which greatly influences their photosynthetic activity. Diatoms, dominated by Amphora sp., are abundant in the anoxic, sulfidic and essentially dark parts of the stromatolites. Although their origin in the stromatolites is unclear, they are possibly an important source of anaerobically degraded organic matter that induces in situ aragonite precipitation. To the best of our knowledge, this is so far the highest altitude with documented actively forming stromatolites. Their generally rich, diverse and to a large extent novel microbial community likely harbours valuable genetic and proteomic reserves, and thus deserves active protection. Furthermore, since the stromatolites flourish in an environment characterized by a multitude of extremes, including high exposure to UV radiation, they can be an excellent model system for studying microbial adaptations under conditions that, at least in part, resemble those during the early phase of life evolution on Earth.

The Discovery of Stromatolites Developing at 3570 m above Sea Level in a High-Altitude Volcanic Lake Socompa, Argentinean Andes

PubMed Central

Farías, María E.; Rascovan, Nicolás; Toneatti, Diego M.; Albarracín, Virginia H.; Flores, María R.; Poiré, Daniel G.; Collavino, Mónica M.; Aguilar, O. Mario; Vazquez, Martin P.; Polerecky, Lubos

2013-01-01

We describe stromatolites forming at an altitude of 3570 m at the shore of a volcanic lake Socompa, Argentinean Andes. The water at the site of stromatolites formation is alkaline, hypersaline, rich in inorganic nutrients, very rich in arsenic, and warm (20–24°C) due to a hydrothermal input. The stromatolites do not lithify, but form broad, rounded and low-domed bioherms dominated by diatom frustules and aragonite micro-crystals agglutinated by extracellular substances. In comparison to other modern stromatolites, they harbour an atypical microbial community characterized by highly abundant representatives of Deinococcus-Thermus, Rhodobacteraceae, Desulfobacterales and Spirochaetes. Additionally, a high proportion of the sequences that could not be classified at phylum level showed less than 80% identity to the best hit in the NCBI database, suggesting the presence of novel distant lineages. The primary production in the stromatolites is generally high and likely dominated by Microcoleus sp. Through negative phototaxis, the location of these cyanobacteria in the stromatolites is controlled by UV light, which greatly influences their photosynthetic activity. Diatoms, dominated by Amphora sp., are abundant in the anoxic, sulfidic and essentially dark parts of the stromatolites. Although their origin in the stromatolites is unclear, they are possibly an important source of anaerobically degraded organic matter that induces in situ aragonite precipitation. To the best of our knowledge, this is so far the highest altitude with documented actively forming stromatolites. Their generally rich, diverse and to a large extent novel microbial community likely harbours valuable genetic and proteomic reserves, and thus deserves active protection. Furthermore, since the stromatolites flourish in an environment characterized by a multitude of extremes, including high exposure to UV radiation, they can be an excellent model system for studying microbial adaptations under conditions that, at least in part, resemble those during the early phase of life evolution on Earth. PMID:23308236

High surface area TiO2/SBA-15 nanocomposites: Synthesis, microstructure and adsorption-enhanced photocatalysis

NASA Astrophysics Data System (ADS)

Wei, J. Q.; Chen, X. J.; Wang, P. F.; Han, Y. B.; Xu, J. C.; Hong, B.; Jin, H. X.; Jin, D. F.; Peng, X. L.; Li, J.; Yang, Y. T.; Ge, H. L.; Wang, X. Q.

2018-06-01

Mesoporous SBA-15 was used to anchor TiO2 nanoparticles into the mesopores to form high surface area TiO2/SBA-15 nanocomposites, and then the influence of mesoporous-structure on the photocatalytic performance was investigated. TiO2/SBA-15 nanocomposites possessed the high specific surface area and appropriate pore size, indicating the excellent adsorption performance. TiO2/SBA-15 nanocomposites exhibited the higher photocatalytic activity to degrade dyes (methylene blue: MB) than TiO2 (removing SBA-15), which should attributed to the excellent adsorption performance of the nanocomposites. MB was absorbed to form the higher concentration near TiO2/SBA-15 photocatalysts, and the photocatalytic degradation for MB was improved.

Need for cognition can magnify or attenuate priming effects in social judgment.

PubMed

Petty, Richard E; DeMarree, Kenneth G; Briñol, Pablo; Horcajo, Javier; Strathman, Alan J

2008-07-01

This article hypothesizes that the individual-difference variable, need for cognition (NFC), can have opposite implications for priming effects, depending on prime blatancy. Subtle primes are argued to be more effective for high- versus low-NFC individuals. This is because for high-NFC individuals, (a) constructs are generally easier to activate, (b) their higher amount of thought offers more opportunity for an activated construct to bias judgment, and (c) their thoughtfully formed judgments are more likely to affect behavior. However, because high-NFC individuals are adept at identifying and correcting for bias, with blatant primes the activated construct should be less likely to exert its default influence. Furthermore, with blatant primes, low-NFC individuals may achieve sufficient activation for primes to affect judgment. Across three studies, it is shown that as NFC increases, the magnitude of priming effects increases with a subtle prime but decreases with a blatant prime.

Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

PubMed

Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

2017-01-11

Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

The novel oral glucan synthase inhibitor SCY-078 shows in vitro activity against sessile and planktonic Candida spp.

PubMed

Marcos-Zambrano, Laura Judith; Gómez-Perosanz, Marta; Escribano, Pilar; Bouza, Emilio; Guinea, Jesús

2017-07-01

We studied the antifungal activity of SCY-078 (an orally bioavailable 1,3-β -d- glucan synthesis inhibitor), micafungin and fluconazole against the planktonic and sessile forms of 178 Candida and non- Candida isolates causing fungaemia in patients recently admitted to a large European hospital. The in vitro activity of SCY-078, micafungin and fluconazole against the planktonic form of the isolates was assessed using EUCAST EDef 7.3 and CLSI M27-A3. Antibiofilm activity was assessed using the XTT reduction assay. SCY-078 and micafungin showed potent in vitro activity against Candida and non- Candida isolates. The in vitro activity of both drugs was similar, but SYC-078 displayed significantly lower MIC values than micafungin against Candida parapsilosis and non- Candida isolates, whereas micafungin displayed significantly lower MIC values for the remaining species ( P  <0.001). In contrast, SCY-078 and micafungin showed essentially the same activity against the biofilms with the exception of Candida glabrata , in which the micafungin sessile MIC values were significantly lower ( P  <0.001). These observations were confirmed by assessing biofilm structure by scanning electron microscopy after antifungal treatment. Our study showed that the high in vitro activity of SCY-078 against invasive Candida isolates in both sessile and planktonic forms is comparable to that of micafungin. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Structure of polyhydroxyalkanoate (PHA) synthase PhaC from Chromobacterium sp. USM2, producing biodegradable plastics.

PubMed

Chek, Min Fey; Kim, Sun-Yong; Mori, Tomoyuki; Arsad, Hasni; Samian, Mohammed Razip; Sudesh, Kumar; Hakoshima, Toshio

2017-07-13

Polyhydroxyalkanoate (PHA) is a promising candidate for use as an alternative bioplastic to replace petroleum-based plastics. Our understanding of PHA synthase PhaC is poor due to the paucity of available three-dimensional structural information. Here we present a high-resolution crystal structure of the catalytic domain of PhaC from Chromobacterium sp. USM2, PhaC Cs -CAT. The structure shows that PhaC Cs -CAT forms an α/β hydrolase fold comprising α/β core and CAP subdomains. The active site containing Cys291, Asp447 and His477 is located at the bottom of the cavity, which is filled with water molecules and is covered by the partly disordered CAP subdomain. We designated our structure as the closed form, which is distinct from the recently reported catalytic domain from Cupriavidus necator (PhaC Cn -CAT). Structural comparison showed PhaC Cn -CAT adopting a partially open form maintaining a narrow substrate access channel to the active site, but no product egress. PhaC Cs -CAT forms a face-to-face dimer mediated by the CAP subdomains. This arrangement of the dimer is also distinct from that of the PhaC Cn -CAT dimer. These findings suggest that the CAP subdomain should undergo a conformational change during catalytic activity that involves rearrangement of the dimer to facilitate substrate entry and product formation and egress from the active site.

The activity of hydrolases of larval stages of Anisakis simplex (Nematoda).

PubMed

Lopieńska-Biernat, Elzbieta; Zółtowska, Krystyna; Rokicki, Jerzy

2004-01-01

Activity of hydrolases during the third and fourth larval stage of Anisakis simplex was identified by applying the API ZYM test method. In A. simplex larvae the activity of phosphatases was high, particularly that of acid phosphatase (40 nmol/mg(-1)). Among esterases lack of activity of lipase (C14) is worth noticing while the activity of esterases (C4) and (C8) was high. The activity of those later two enzymes was higher in L3 larvae than in L4 larvae. The highest activity in the subclass of glucosidases was recorded for beta-fucosidase and N-acetyl-beta-glucosaminidase. A higher activity in L3 larvae than in L4 larvae was recorded for: beta-glucuronidase and N-acetyl-beta-glucosaminidase (2-fold) and beta-fucosidase (3-fold). Differently the activity of beta-galactosidase and beta-glucosidase was higher in L4 larvae than in L3 larvae. The tests did not show activity of alpha-galactosidase, beta-glucosidase and alpha-mannosidase on both larval forms.

Thick electrodes including nanoparticles having electroactive materials and methods of making same

DOEpatents

Xiao, Jie; Lu, Dongping; Liu, Jun; Zhang, Jiguang; Graff, Gordon L.

2017-02-21

Electrodes having nanostructure and/or utilizing nanoparticles of active materials and having high mass loadings of the active materials can be made to be physically robust and free of cracks and pinholes. The electrodes include nanoparticles having electroactive material, which nanoparticles are aggregated with carbon into larger secondary particles. The secondary particles can be bound with a binder to form the electrode.

Pixantrone can be activated by formaldehyde to generate a potent DNA adduct forming agent

PubMed Central

Evison, Ben J.; Mansour, Oula C.; Menta, Ernesto; Phillips, Don R.; Cutts, Suzanne M.

2007-01-01

Mitoxantrone is an anti-cancer agent used in the treatment of breast and prostate cancers. It is classified as a topoisomerase II poison, however can also be activated by formaldehyde to generate drug–DNA adducts. Despite identification of this novel form of mitoxantrone–DNA interaction, excessively high, biologically irrelevant drug concentrations are necessary to generate adducts. A search for mitoxantrone analogues that could potentially undergo this reaction with DNA more efficiently identified Pixantrone as an ideal candidate. An in vitro crosslinking assay demonstrated that Pixantrone is efficiently activated by formaldehyde to generate covalent drug–DNA adducts capable of stabilizing double-stranded DNA in denaturing conditions. Pixantrone–DNA adduct formation is both concentration and time dependent and the reaction exhibits an absolute requirement for formaldehyde. In a direct comparison with mitoxantrone–DNA adduct formation, Pixantrone exhibited a 10- to 100-fold greater propensity to generate adducts at equimolar formaldehyde and drug concentrations. Pixantrone–DNA adducts are thermally and temporally labile, yet they exhibit a greater thermal midpoint temperature and an extended half-life at 37°C when compared to mitoxantrone–DNA adducts. Unlike mitoxantrone, this enhanced stability, coupled with a greater propensity to form covalent drug–DNA adducts, may endow formaldehyde-activated Pixantrone with the attributes required for Pixantrone–DNA adducts to be biologically active. PMID:17483512

Complete secretion of activable bovine prochymosin by genetically engineered L forms of Proteus mirabilis.

PubMed Central

Klessen, C; Schmidt, K H; Gumpert, J; Grosse, H H; Malke, H

1989-01-01

To circumvent problems encountered in the synthesis of active chymosin in a number of bacteria and fungi, a recombinant DNA L-form expression system that directed the complete secretion of fully activable prochymosin into the extracellular culture medium was developed. The expression plasmid constructions involved the in-frame fusion of prochymosin cDNA minus codons 1 to 4 to streptococcal pyrogenic exotoxin type A gene (speA') sequences, including the speA promoter, ribosomal binding site, and signal sequence and five codons of mature SpeA. Secretion of fusion prochymosin enzymatically and immunologically indistinguishable from bovine prochymosin was achieved after transformation of two stable protoplast type L-form strains derived from Proteus mirabilis. The secreted proenzyme was converted by autocatalytic processing to chymosin showing milk-clotting activity. In controlled laboratory fermentation processes, a maximum specific rate of activable prochymosin synthesis of 0.57 x 10(-3)/h was determined from the time courses of biomass dry weight and product formation. Yields as high as 40 +/- 10 micrograms/ml were obtained in the cell-free culture fluid of strain L99 carrying a naturally altered expression plasmid of increased segregational stability. The expression-secretion system described may be generally useful for production of recombinant mammalian proteins synthesized intracellularly as aberrantly folded insoluble aggregates. Images PMID:2499253

[Obsessive-compulsive symptoms, tics, stereotypic movements or need for absolute consistency? The occurrence of repetitive activities in patients with pervasive developmental disorders--case studies].

PubMed

Bryńska, Anita; Lipińska, Elzbieta; Matelska, Monika

2011-01-01

Repetitive and stereotyped behaviours in the form of stereotyped interests or specific routine activities are one ofthe diagnostic criteria in pervasive developmental disorders. The occurrence of repetitive behaviours in patients with pervasive developmental disorders is a starting point for questions about the type and classification criteria of such behaviours. The aim of the article is to present case studies of patients with pervasive developmental disorders and co-morbid symptoms in the form of routine activities, tics, obsessive-compulsive symptoms or stereotyped behaviours. The first case study describes a patient with Asperger's syndrome and obsessive compulsive symptoms. The diagnostic problems regarding complex motor tics are discussed in the second case study which describes a patient with Asperger's syndrome and Gilles de la Tourette syndrome. The third and fourth case study describes mono-zygotic twins with so called High Functioning Autism whose repetitive activities point to either obsessive compulsive symptoms, stereotypic movements, need for absolute consistency or echopraxia. The possible comorbidity of pervasive developmental disorders and symptoms in the form of repetitive behaviours, possible interactions as well as diagnostic challenges is discussed in the article.

Transition Metal Ions in Zeolites: Coordination and activation of O2

PubMed Central

Smeets, Pieter J.; Woertink, Julia S.; Sels, Bert F.; Solomon, Edward I.; Schoonheydt, Robert A.

2010-01-01

Zeolites containing transition metal ions (TMI) often show promising activity as heterogeneous catalysts in pollution abatement and selective oxidation reactions. In this paper, two aspects of research on the TMI Cu, Co and Fe in zeolites are discussed: (i) coordination to the lattice and (ii) activated oxygen species. At low loading, TMI preferably occupy exchange sites in six-membered oxygen rings (6MR) where the TMI preferentially coordinate with the oxygen atoms of Al tetrahedra. High TMI loadings result in a variety of TMI species formed at the zeolite surface. Removal of the extra-lattice oxygens during high temperature pretreatments can result in auto-reduction. Oxidation of reduced TMI sites often results in the formation of highly reactive oxygen species. In Cu-ZSM-5, calcination with O2 results in the formation of a species, which was found to be a crucial intermediate in both the direct decomposition of NO and N2O and the selective oxidation of methane into methanol. An activated oxygen species, called α-oxygen, is formed in Fe-ZSM5 and reported to be the active site in the partial oxidation of methane and benzene into methanol and phenol, respectively. However, this reactive α-oxygen can only be formed with N2O, not with O2. O2 activated Co intermediates in Faujasite (FAU) zeolites can selectively oxidize α-pinene and epoxidize styrene. In Co-FAU, CoIII superoxo and peroxo complexes are suggested to be the active cores, whereas in Cu and Fe-ZSM-5 various monomeric and dimeric sites have been proposed, but no consensus has been obtained. Very recently, the active site in Cu-ZSM-5 was identified as a bent [Cu-O-Cu]2+ core (Proc. Natl. Acad. Sci. USA 2009, 106, 18908-18913). Overall, O2 activation depends on the interplay of structural factors such as type of zeolite, size of the channels and cages and chemical factors such as Si/Al ratio and the nature, charge and distribution of the charge balancing cations. The presence of several different TMI sites hinders the direct study of the spectroscopic features of the active site. Spectroscopic techniques capable of selectively probing these sites, even if they only constitute a minor fraction of the total amount of TMI sites, are thus required. Fundamental knowledge of the geometric and electronic structure of the reactive active site can help in the design of novel selective oxidation catalysts. PMID:20380459

Radon as a natural tracer for underwater cave exploration and hypogenic cave formation

NASA Astrophysics Data System (ADS)

Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

2017-04-01

Using 222Rn as a natural tracer is a novel approach in underwater cave exploration and in the research of active hypogenic caves. The research area, the Molnár János cave is one of the largest caves of an unique hypogenic karst system, the Buda Thermal Karst (Budapest, Hungary). The cave system is mainly characterized by water-filled passages. The cave is located at one of the main discharge areas of the Buda Thermal Karst and the major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous complex hydrogeological studies and radon measurements in the cave system and in the spring established the highest radon concentration (71 Bq/L, where the average is 44 Bq/L) in the springwater. The origin of radon was identified in the form of iron-hydroxide containing biofilms, which form by mixing of waters and efficiently adsorb radium from the thermal water component and cause local radon anomalies. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and consequently high radon concentrations mark the active cave forming zones. The aim of the study was to use the radon as a natural tracer to locate active mixing and cave forming zones. Based on previous radon measurements it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore, the radon activity concentration mapping was carried out with the help of divers and involving that part of the cave which closest to the spring. Based on our measurements the highest radon concentration (84 Bq/L) ever was achieved in the springwater. Based on the radon concentration distribution direct connection and active karst conduit was established between the spring and the deepest room of the researched part of the cave, which was verified by artificial tracer as well. However, the distribution of radon in the cave passages shows lower concentrations (18-46 Bq/L) compared to the spring, therefore an addition deep inflow from a hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are supposed to be in the active cave formation (mixing) zone. The Buda Thermal Karst research was funded by the Hungarian Scientific Research Fund under the grant agreement no. NK 101356.

The kinase activity of fibroblast growth factor receptor 3 with activation loop mutations affects receptor trafficking and signaling.

PubMed

Lievens, Patricia M-J; Mutinelli, Chiara; Baynes, Darcie; Liboi, Elio

2004-10-08

Amino acid substitutions at the Lys-650 codon within the activation loop kinase domain of fibroblast growth factor receptor 3 (FGFR3) result in graded constitutive phosphorylation of the receptor. Accordingly, the Lys-650 mutants are associated with dwarfisms with graded clinical severity. To assess the importance of the phosphorylation level on FGFR3 maturation along the secretory pathway, hemagglutinin A-tagged derivatives were studied. The highly activated SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) mutant accumulates in its immature and phosphorylated form in the endoplasmic reticulum (ER), which fails to be degraded. Furthermore, the Janus kinase (Jak)/STAT pathway is activated from the ER by direct recruitment of Jak1. Abolishing the autocatalytic property of the mutated FGFR3 by replacing the critical Tyr-718 reestablishes the receptor full maturation and inhibits signaling. Differently, the low activated hypochondroplasia mutant is present as a mature phosphorylated form on the plasma membrane, although with a delayed transition in the ER, and is completely processed. Signaling does not occur in the presence of brefeldin A; instead, STAT1 is activated when protein secretion is blocked with monensin, suggesting that the hypochondroplasia receptor signals at the exit from the ER. Our results suggest that kinase activity affects FGFR3 trafficking and determines the spatial segregation of signaling pathways. Consequently, the defect in down-regulation of the highly activated receptors results in the increased signaling capacity from the intracellular compartments, and this may determine the severity of the diseases.

Chemical and phase evolution of amorphous molybdenum sulfide catalysts for electrochemical hydrogen production [Chemical and phase evolution of amorphous molybdenum sulfide catalysts for electrochemical hydrogen production directly observed using environmental transmission electron microscopy

DOE PAGES

Lee, Sang Chul; Benck, Jesse D.; Tsai, Charlie; ...

2015-12-01

Amorphous MoS x is a highly active, earth-abundant catalyst for the electrochemical hydrogen evolution reaction. Previous studies have revealed that this material initially has a composition of MoS 3, but after electrochemical activation, the surface is reduced to form an active phase resembling MoS 2 in composition and chemical state. However, structural changes in the Mo Sx catalyst and the mechanism of the activation process remain poorly understood. In this study, we employ transmission electron microscopy (TEM) to image amorphous MoS x catalysts activated under two hydrogen-rich conditions: ex situ in an electrochemical cell and in situ in an environmentalmore » TEM. For the first time, we directly observe the formation of crystalline domains in the MoS x catalyst after both activation procedures as well as spatially localized changes in the chemical state detected via electron energy loss spectroscopy. Using density functional theory calculations, we investigate the mechanisms for this phase transformation and find that the presence of hydrogen is critical for enabling the restructuring process. Our results suggest that the surface of the amorphous MoS x catalyst is dynamic: while the initial catalyst activation forms the primary active surface of amorphous MoS 2, continued transformation to the crystalline phase during electrochemical operation could contribute to catalyst deactivation. Finally, these results have important implications for the application of this highly active electrocatalyst for sustainable H 2 generation.« less

Spectroscopic studies on the active site of hydroperoxide lyase; the influence of detergents on its conformation.

PubMed

Noordermeer, M A; Veldink, G A; Vliegenthart, J F

2001-02-02

Expression of high quantities of alfalfa hydroperoxide lyase in Escherichia coli made it possible to study its active site and structure in more detail. Circular dichroism (CD) spectra showed that hydroperoxide lyase consists for about 75% of alpha-helices. Electron paramagnetic resonance (EPR) spectra confirmed its classification as a cytochrome P450 enzyme. The positive influence of detergents on the enzyme activity is paralleled by a spin state transition of the heme Fe(III) from low to high spin. EPR and CD spectra showed that detergents induce a subtle conformational change, which might result in improved substrate binding. Because hydroperoxide lyase is thought to be a membrane bound protein and detergents mimic a membrane environment, the more active, high spin form likely represents the in vivo conformation. Furthermore, the spin state appeared to be temperature-dependent, with the low spin state favored at low temperature. Point mutants of the highly conserved cysteine in domain D indicated that this residue might be involved in heme binding.

Catalytic conversion of methane to methanol using Cu-zeolites.

PubMed

Alayon, Evalyn Mae C; Nachtegaal, Maarten; Ranocchiari, Marco; van Bokhoven, Jeroen A

2012-01-01

The conversion of methane to value-added liquid chemicals is a promising answer to the imminent demand for fuels and chemical synthesis materials in the advent of a dwindling petroleum supply. Current technology requires high energy input for the synthesis gas production, and is characterized by low overall selectivity, which calls for alternative reaction routes. The limitation to achieve high selectivity is the high C-H bond strength of methane. High-temperature reaction systems favor gas-phase radical reactions and total oxidation. This suggests that the catalysts for methane activation should be active at low temperatures. The enzymatic-inspired metal-exchanged zeolite systems apparently fulfill this need, however, methanol yield is low and a catalytic process cannot yet be established. Homogeneous and heterogeneous catalytic systems have been described which stabilize the intermediate formed after the first C-H activation. The understanding of the reaction mechanism and the determination of the active metal sites are important for formulating strategies for the upgrade of methane conversion catalytic technologies.

Relationship between the latest activity of mare volcanism and topographic features of the Moon

NASA Astrophysics Data System (ADS)

Kato, Shinsuke; Morota, Tomokatsu; Yamaguchi, Yasushi; Watanabe, Sei-ichiro; Otake, Hisashi; Ohtake, Makiko

2016-04-01

Lunar mare basalts provide insights into compositions and thermal history of lunar mantle. According to crater counting analysis with remote sensing data, the model ages of mare basalt units indicate a second peak of magma activity at the end of mare volcanism (~2 Ga), and the latest eruptions were limited in the Procellarum KREEP Terrane (PKT), which has high abundances of heat-producing elements. In order to understand the mechanism for causing the second peak and its magma source, we examined the correlation between the titanium contents and eruption ages of mare basalt units using compositional and chronological data updated by SELENE/Kaguya. Although no systematic relationship is observed globally, a rapid increase in mean titanium (Ti) content occurred at 2.3 Ga in the PKT, suggesting that the magma source of mare basalts changed at that time. The high-Ti basaltic eruption, which occurred at the late stage of mare volcanism, can be correlated with the second peak of volcanic activity at ~2 Ga. The latest volcanic activity can be explained by a high-Ti hot plume originated from the core-mantle boundary. If the hot plume was occurred, the topographic features formed by the hot plume may be remained. We calculated the difference between topography and selenoid and found the circular feature like a plateau in the center of the PKT, which scale is ~1000 km horizontal and ~500 m vertical. We investigated the timing of ridge formation in the PKT by using stratigraphic relationship between mare basalts and ridges. The ridges were formed before and after the high-Ti basaltic eruptions and seem to be along with the plateau. These results suggest that the plateau formation is connected with the high-Ti basaltic eruptions.

Enhanced enzyme kinetic stability by increasing rigidity within the active site.

PubMed

Xie, Yuan; An, Jiao; Yang, Guangyu; Wu, Geng; Zhang, Yong; Cui, Li; Feng, Yan

2014-03-14

Enzyme stability is an important issue for protein engineers. Understanding how rigidity in the active site affects protein kinetic stability will provide new insight into enzyme stabilization. In this study, we demonstrated enhanced kinetic stability of Candida antarctica lipase B (CalB) by mutating the structurally flexible residues within the active site. Six residues within 10 Å of the catalytic Ser(105) residue with a high B factor were selected for iterative saturation mutagenesis. After screening 2200 colonies, we obtained the D223G/L278M mutant, which exhibited a 13-fold increase in half-life at 48 °C and a 12 °C higher T50(15), the temperature at which enzyme activity is reduced to 50% after a 15-min heat treatment. Further characterization showed that global unfolding resistance against both thermal and chemical denaturation also improved. Analysis of the crystal structures of wild-type CalB and the D223G/L278M mutant revealed that the latter formed an extra main chain hydrogen bond network with seven structurally coupled residues within the flexible α10 helix that are primarily involved in forming the active site. Further investigation of the relative B factor profile and molecular dynamics simulation confirmed that the enhanced rigidity decreased fluctuation of the active site residues at high temperature. These results indicate that enhancing the rigidity of the flexible segment within the active site may provide an efficient method for improving enzyme kinetic stability.

pH-Induced interfacial properties of Chaplin E from Streptomyces coelicolor.

PubMed

Dokouhaki, Mina; Hung, Andrew; Prime, Emma L; Qiao, Greg G; Day, Li; Gras, Sally L

2017-12-01

Chaplin E, or Chp E, is a surface active peptide secreted by Streptomyces coelicolor that adopts different structures depending on solution pH but the effect of these structures on the interfacial properties of Chp E is not known. In experiments paired with simulations, Chp E was found to display pH-dependent interfacial assembly and surface activity. At pH 3.0, Chp E formed an ordered non-amyloidal interfacial film with high surface activity; while at pH 10.0, Chp E self-assembled into a heterogeneous film containing randomly arranged fibrils at the interface that was less surface active compared to the film formed at pH 3.0. In simulations at pH 10.0, Chp E molecules showed a higher propensity for dimerization within the solution phase, lower rate of adsorption to the interface and tighter inter-molecular associations at the interface, consistent with the lower surface activity and smaller interfacial area coverage per molecule measured at this pH compared to at pH 3.0. A model is presented for the role of Chp E in the developmental differentiation of Streptomyces coelicolor, where Chp E contributes to changes in surface tension at low pH and the formation of fibrils on the surface of aerial hyphae at high pH. Our data also suggest Chp E could be a promising surface active agent with functional activity that can be controlled by pH. Copyright © 2017 Elsevier B.V. All rights reserved.

New solid-state chemistry technologies to bring better drugs to market: knowledge-based decision making.

PubMed

Park, Aeri; Chyall, Leonard J; Dunlap, Jeanette; Schertz, Christine; Jonaitis, David; Stahly, Barbara C; Bates, Simon; Shipplett, Rex; Childs, Scott

2007-01-01

Modern drug development demands constant deployment of more effective technologies to mitigate the high cost of bringing new drugs to market. In addition to cost savings, new technologies can improve all aspects of pharmaceutical development. New technologies developed at SSCI, Inc. include solid form development of an active pharmaceutical ingredients. (APIs) are PatternMatch software and capillary-based crystallisation techniques that not only allow for fast and effective solid form screening, but also extract maximum property information from the routine screening data that is generally available. These new technologies offer knowledge-based decision making during solid form development of APIs and result in more developable API solid forms.

Iodide Protects Heart Tissue from Reperfusion Injury

PubMed Central

Iwata, Akiko; Morrison, Michael L.; Roth, Mark B.

2014-01-01

Iodine is an elemental nutrient that is essential for mammals. Here we provide evidence for an acute therapeutic role for iodine in ischemia reperfusion injury. Infusion of the reduced form, iodide, but not the oxidized form iodate, reduces heart damage by as much as 75% when delivered intravenously following temporary loss of blood flow but prior to reperfusion of the heart in a mouse model of acute myocardial infarction. Normal thyroid function may be required because loss of thyroid activity abrogates the iodide benefit. Given the high degree of protection and the high degree of safety, iodide should be explored further as a therapy for reperfusion injury. PMID:25379708

Target-induced formation of neuraminidase inhibitors from in vitro virtual combinatorial libraries

PubMed Central

Hochgürtel, Matthias; Kroth, Heiko; Piecha, Dorothea; Hofmann, Michael W.; Nicolau, Claude; Krause, Sonja; Schaaf, Otmar; Sonnenmoser, Gabriele; Eliseev, Alexey V.

2002-01-01

Neuraminidase, a key enzyme responsible for influenza virus propagation, has been used as a template for selective synthesis of small subsets of its own inhibitors from theoretically highly diverse dynamic combinatorial libraries. We show that the library building blocks, aldehydes and amines, form significant amounts of the library components resulting from their coupling by reductive amination only in the presence of the enzyme. The target amplifies the best hits at least 120-fold. The dynamic libraries synthesized and screened in such an in vitro virtual mode form the components that possess high inhibitory activity, as confirmed by enzyme assays with independently synthesized individual compounds. PMID:11891312

The Rest-frame Ultraviolet Spectra of UV-selected Active Galactic Nuclei at z ~ 2-3

NASA Astrophysics Data System (ADS)

Hainline, Kevin N.; Shapley, Alice E.; Greene, Jenny E.; Steidel, Charles C.

2011-05-01

We present new results for a sample of 33 narrow-lined UV-selected active galactic nuclei (AGNs), identified in the course of a spectroscopic survey for star-forming galaxies at z ~ 2-3. The rest-frame UV composite spectrum for our AGN sample shows several emission lines characteristic of AGNs, as well as interstellar absorption features detected in star-forming Lyman break galaxies (LBGs). We report a detection of N IV] λ1486, which has been observed in high-redshift radio galaxies, as well as in rare optically selected quasars. The UV continuum slope of the composite spectrum is significantly redder than that of a sample of non-AGN UV-selected star-forming galaxies. Blueshifted Si IV absorption provides evidence for outflowing highly ionized gas in these objects at speeds of ~103 km s-1, quantitatively different from what is seen in the outflows of non-AGN LBGs. Grouping the individual AGNs by parameters such as the Lyα equivalent width, redshift, and UV continuum magnitude allows for an analysis of the major spectroscopic trends within the sample. Stronger Lyα emission is coupled with weaker low-ionization absorption, which is similar to what is seen in the non-AGN LBGs, and highlights the role that cool interstellar gas plays in the escape of Lyα photons. However, the AGN composite does not show the same trends between Lyα strength and extinction seen in the non-AGN LBGs. These results represent the first such comparison at high redshift between star-forming galaxies and similar galaxies that host AGN activity. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

PubMed

Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

2010-02-05

Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols detection the developed sensor system is characterized by simplicity of operation, compactness, and low cost. Copyright 2009 Elsevier B.V. All rights reserved.

Curcumin β-D-Glucuronide Plays an Important Role to Keep High Levels of Free-Form Curcumin in the Blood.

PubMed

Ozawa, Hitomi; Imaizumi, Atsushi; Sumi, Yoshihiko; Hashimoto, Tadashi; Kanai, Masashi; Makino, Yuji; Tsuda, Takanori; Takahashi, Nobuaki; Kakeya, Hideaki

2017-01-01

Curcumin, a polyphenol derived from the rhizome of the naturally occurring plant Curcuma longa, has various pharmacological actions such as antioxidant and anti-inflammatory effects. In this paper, we evaluated the role of its internal metabolite, curcumin β-D-glucuronide (curcumin monoglucuronide, CMG), by investigating curcumin kinetics and metabolism in the blood. Firstly, we orally administered highly bioavailable curcumin to rats to elucidate its kinetics, and observed not only the free-form of curcumin, but also, curcumin in a conjugated form, within the portal vein. We confirmed that curcumin is conjugated when it passes through the intestinal wall. CMG, one of the metabolites, was then orally administered to rats. Despite its high aqueous solubility compared to free-form curcumin, it was not well absorbed. In addition, CMG was injected intravenously into rats in order to assess its metabolic behavior in the blood. Interestingly, high levels of free-form curcumin, thought to be sufficiently high to be pharmacologically active, were observed. The in vivo antitumor effects of CMG following intravenous injection were then evaluated in tumor-bearing mice with the HCT116 human colon cancer cell line. The tumor volume within the CMG group was significantly less than that of the control group. Moreover, there was no significant loss of body weight in the CMG group compared to the control group. These results suggest that CMG could be used as an anticancer agent without the serious side effects that most anticancer agents have.

Methanation of gas streams containing carbon monoxide and hydrogen

DOEpatents

Frost, Albert C.

1983-01-01

Carbon monoxide-containing gas streams having a relatively high concentration of hydrogen are pretreated so as to remove the hydrogen in a recoverable form for use in the second step of a cyclic, essentially two-step process for the production of methane. The thus-treated streams are then passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. This active carbon is reacted with said hydrogen removed from the feed gas stream to form methane. The utilization of the CO in the feed gas stream is appreciably increased, enhancing the overall process for the production of relatively pure, low-cost methane from CO-containing waste gas streams.

Sorbents for the oxidation and removal of mercur

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, Edwin S.; Holmes, Michael J.; Pavlish, John Henry

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbentmore » into the mercury contaminated gas stream are described.« less

Continuous high-frequency activity in mesial temporal lobe structures

PubMed Central

Mari, Francesco; Zelmann, Rina; Andrade-Valenca, Luciana; Dubeau, Francois; Gotman, Jean

2013-01-01

Summary Purpose Many recent studies have reported the importance of high-frequency oscillations (HFOs) in the intracerebral electroencephalography (EEG) of patients with epilepsy. These HFOs have been defined as events that stand out from the background. We have noticed that this background often consists itself of high-frequency rhythmic activity. The purpose of this study is to perform a first evaluation of the characteristics of high-frequency continuous or semicontinuous background activity. Methods Because the continuous high-frequency pattern was noted mainly in mesial temporal structures, we reviewed the EEG studies from these structures in 24 unselected patients with electrodes implanted in these regions. Sections of background away from interictal spikes were marked visually during periods of slow-wave sleep and wakefulness. They were then high-passed filtered at 80 Hz and categorized as having high-frequency rhythmic activity in one of three patterns: continuous/semicontinuous, irregular, sporadic. Wavelet entropy, which measures the degree of rhythmicity of a signal, was calculated for the marked background sections. Key Findings Ninety-six bipolar channels were analyzed. The continuous/semicontinuous pattern was found frequently (29/96 channels during wake and 34/96 during sleep). The different patterns were consistent between sleep and wakefulness. The continuous/semicontinuous pattern was found significantly more often in the hippocampus than in the parahippocampal gyrus and was rarely found in the amygdala. The types of pattern were not influenced by whether a channel was within the seizure-onset zone, or whether it was a lesional channel. The continuous/semicontinuous pattern was associated with a higher frequency of spikes and with high rates of ripples and fast ripples. Significance It appears that high-frequency activity (above 80 Hz) does not appear only in the form of brief paroxysmal events but also in the form of continuous rhythmic activity or very long bursts. In this study limited to mesial temporal structures, we found a clear anatomic preference for the hippocampus. Although associated with spikes and with distinct HFOs, this pattern was not clearly associated with the seizure-onset zone. Future studies will need to evaluate systematically the presence of this pattern, as it may have a pathophysiologic significance and it will also have an important influence on the very definition of HFOs. PMID:22416973

High energy XeBr electric discharge laser

DOEpatents

Sze, Robert C.; Scott, Peter B.

1981-01-01

A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

Monolithic amplifier with stable, high resistance feedback element and method for fabricating the same

DOEpatents

O`Connor, P.

1998-08-11

A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit. 11 figs.

Bifunctional Asymmetric Catalysis with Hydrogen Chloride: Enantioselective Ring-Opening of Aziridines Catalyzed by a Phosphinothiourea

PubMed Central

Mita, Tsuyoshi; Jacobsen, Eric N.

2009-01-01

Ring-opening of aziridines with hydrogen chloride to form β-chloroamine derivatives is catalyzed by a chiral phosphinothiourea derivative in high yields and with high enantioselectivities. On the basis of 31P NMR studies, activation of HCl appears to proceed via quantitative protonation of the catalyst to afford a phosphonium chloride complex. PMID:20161432

High energy XeBr electric discharge laser

DOEpatents

Sze, R.C.; Scott, P.B.

A high energy XeBr laser for producing coherent radiation at 282 nm is disclosed. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr, is used as the halogen donor which undergoes harpooning reactions with Xe/sub M/ to form XeBr.

Isolated low-valent nickel

NASA Astrophysics Data System (ADS)

Mul, Guido

2018-02-01

Electrochemical conversion of CO2 to fuels is an attractive pathway to store electrical energy in chemical form. Isolated, low-valent Ni species in nitrogen-doped graphene are now demonstrated to selectively convert CO2 to CO electrochemically with high intrinsic activity and stability.

A simple and predictive phenotypic High Content Imaging assay for Plasmodium falciparum mature gametocytes to identify malaria transmission blocking compounds

PubMed Central

Lucantoni, Leonardo; Silvestrini, Francesco; Signore, Michele; Siciliano, Giulia; Eldering, Maarten; Dechering, Koen J.; Avery, Vicky M.; Alano, Pietro

2015-01-01

Plasmodium falciparum gametocytes, specifically the mature stages, are the only malaria parasite stage in humans transmissible to the mosquito vector. Anti-malarial drugs capable of killing these forms are considered essential for the eradication of malaria and tools allowing the screening of large compound libraries with high predictive power are needed to identify new candidates. As gametocytes are not a replicative stage it is difficult to apply the same drug screening methods used for asexual stages. Here we propose an assay, based on high content imaging, combining “classic” gametocyte viability readout based on gametocyte counts with a functional viability readout, based on gametocyte activation and the discrimination of the typical gamete spherical morphology. This simple and rapid assay has been miniaturized to a 384-well format using acridine orange staining of wild type P. falciparum 3D7A sexual forms, and was validated by screening reference antimalarial drugs and the MMV Malaria Box. The assay demonstrated excellent robustness and ability to identify quality hits with high likelihood of confirmation of transmission reducing activity in subsequent mosquito membrane feeding assays. PMID:26553647

Porphyrin-induced photogeneration of hydrogen peroxide determined using the luminol chemiluminescence method in aqueous solution: A structure-activity relationship study related to the aggregation of porphyrin.

PubMed

Komagoe, Keiko; Katsu, Takashi

2006-02-01

A luminol chemiluminescence method was used to evaluate the porphyrin-induced photogeneration of hydrogen peroxide (H2O2). This method enabled us to detect H202 in the presence of a high concentration of porphyrin, which was not possible using conventional colorimetry. The limit of detection was about 1 microM. We compared the ability to generate H2O2, using uroporphyrin (UP), hexacarboxylporphyrin (HCP), coproporphyrin (CP), hematoporphyrin (HP), mesoporphyrin (MP), and protoporphyrin (PP). The amount of H2O2 photoproduced was strongly related to the state of the porphyrin in the aqueous solution. UP and HCP, which existed predominantly in a monomeric form, had a good ability to produce H2O2. HP and MP, existing as dimers, showed weak activity. CP, forming a mixture of monomer and dimer, had a moderate ability to produce H2O2. PP, which was highly aggregated, had a good ability. These results demonstrated that the efficiency of porphyrins to produce H2O2 was strongly dependent on their aggregated form, and the dimer suppressed the production of H2O2.

Cavitation Bubble Cluster Activity in the Breakage of Kidney Stones by Lithotripter Shock Waves

PubMed Central

Pishchalnikov, Yuriy A.; Sapozhnikov, Oleg A.; Bailey, Michael R.; Williams, James C.; Cleveland, Robin O.; Colonius, Tim; Crum, Lawrence A.; Evan, Andrew P.; McAteer, James A.

2008-01-01

High-speed photography was used to analyze cavitation bubble activity at the surface of artificial and natural kidney stones during exposure to lithotripter shock waves in vitro. Numerous individual bubbles formed at the surface of stones, but these bubbles did not remain independent and combined with one another to form bubble clusters. Bubble clusters formed at the proximal end, the distal end, and at the sides of stones. Each cluster collapsed to a narrow point of impact. Collapse of the proximal cluster caused erosion at the leading face of the stone and the collapse of clusters at the sides of stones appeared to contribute to the growth of cracks. Collapse of the distal cluster caused minimal damage. We conclude that cavitation-mediated damage to stones was due not to the action of solitary bubbles, but to the growth and collapse of bubble clusters. PMID:14565872

Purification and Characterization of Functional Human Paraoxonase-1 Expressed in Trichoplusia ni Larvae

DTIC Science & Technology

2010-01-01

purified from Trichoplusia ni (T. ni) larvae infected with an orally active form of bac- ulovirus. SDS-PAGE and anti-HuPON1 Western blot analyses yielded...Organophosphorus (OP) nerve agents readily bind covalently o acetylcholinesterase (AChE) at the active site serine and inhibit he ability of AChE to terminate...The results demon- trate that T. ni larvae are capable of producing high quantities of unctionally active recombinant HuPON1, and larvae expressing

Design of an x-ray telescope optics for XEUS

NASA Astrophysics Data System (ADS)

Graue, Roland; Kampf, Dirk; Wallace, Kotska; Lumb, David; Bavdaz, Marcos; Freyberg, Michael

2017-11-01

The X-ray telescope concept for XEUS is based on an innovative high performance and light weight Silicon Pore Optics technology. The XEUS telescope is segmented into 16 radial, thermostable petals providing the rigid optical bench structure of the stand alone XRay High Precision Tandem Optics. A fully representative Form Fit Function (FFF) Model of one petal is currently under development to demonstrate the outstanding lightweight telescope capabilities with high optically effective area. Starting from the envisaged system performance the related tolerance budgets were derived. These petals are made from ceramics, i.e. CeSiC. The structural and thermal performance of the petal shall be reported. The stepwise alignment and integration procedure on petal level shall be described. The functional performance and environmental test verification plan of the Form Fit Function Model and the test set ups are described in this paper. In parallel to the running development activities the programmatic and technical issues wrt. the FM telescope MAIT with currently 1488 Tandem Optics are under investigation. Remote controlled robot supported assembly, simultaneous active alignment and verification testing and decentralised time effective integration procedures shall be illustrated.

An inducible expression system for high-level expression of recombinant proteins in slow growing mycobacteria.

PubMed

Leotta, Lisa; Spratt, Joanne M; Kong, Carlyn U; Triccas, James A

2015-09-01

A novel protein expression vector utilising the inducible hspX promoter of Mycobacterium tuberculosis was constructed and evaluated in this study. High-level induction of three mycobacterial antigens, comprising up to 9% of bacterial sonicate, was demonstrated in recombinant Mycobacterium bovis BCG when grown under low-oxygen tension, which serves to enhance hspX promoter activity. Recombinant proteins were efficiently purified from bacterial lysates in a soluble form by virtue of a C-terminal 6-histidine tag. Purification of the immunodominant M. tuberculosis Ag85B antigen using this system resulted in a recombinant protein that stimulated significant IFN-γ release from Ag85B-reactive T cells generated after vaccination of mice with an Ag85B-expressing vaccine. Further, the M. tuberculosis L-alanine dehydrogenase (Ald) protein purified from recombinant BCG displayed strong enzymatic activity in recombinant form. This study demonstrated that high levels of native-like recombinant mycobacterial proteins can be produced in mycobacterial hosts, and this may aid the analysis of mycobacterial protein function and the development of new treatments. Copyright © 2015 Elsevier B.V. All rights reserved.

Copper Nanoparticles: Synthesis and Biological Activity

NASA Astrophysics Data System (ADS)

Satyvaldiev, A. S.; Zhasnakunov, Z. K.; Omurzak, E.; Doolotkeldieva, T. D.; Bobusheva, S. T.; Orozmatova, G. T.; Kelgenbaeva, Z.

2018-01-01

By means of XRD and FESEM analysis, it is established that copper nanoparticles with sizes less than 10 nm are formed during the chemical reduction, which form aggregates mainly with spherical shape. Presence of gelatin during the chemical reduction of copper induced formation of smaller size distribution nanoparticles than that of nanoparticles synthesized without gelatin and it can be related to formation of protective layer. Synthesized Cu nano-powders have sufficiently high activity against the Erwinia amylovora bacterium, and the bacterial growth inhibition depends on the Cu nanoparticles concentration. At a concentration of 5 mg / ml of Cu nanoparticles, the exciter growth inhibition zone reaches a maximum value within 72 hours and the lysis zone is 20 mm, and at a concentration of 1 mg / ml this value is 16 mm, which also indicates the significant antibacterial activity of this sample.

Spray Drying as a Reliable Route to Produce Metastable Carbamazepine Form IV.

PubMed

Halliwell, Rebecca A; Bhardwaj, Rajni M; Brown, Cameron J; Briggs, Naomi E B; Dunn, Jaclyn; Robertson, John; Nordon, Alison; Florence, Alastair J

2017-07-01

Carbamazepine (CBZ) is an active pharmaceutical ingredient used in the treatment of epilepsy that can form at least 5 polymorphic forms. Metastable form IV was originally discovered from crystallization with polymer additives; however, it has not been observed from subsequent solvent-only crystallization efforts. This work reports the reproducible formation of phase pure crystalline form IV by spray drying of methanolic CBZ solution. Characterization of the material was carried out using diffraction, scanning electron microscopy, and differential scanning calorimetry. In situ Raman spectroscopy was used to monitor the spray-dried product during the spray drying process. This work demonstrates that spray drying provides a robust method for the production of form IV CBZ, and the combination of high supersaturation and rapid solid isolation from solution overcomes the apparent limitation of more traditional solution crystallization approaches to produce metastable crystalline forms. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Apparatus for advancing a wellbore using high power laser energy

DOEpatents

Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

2014-09-02

Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

A Submillimeter Perspective on the Goods Fields. II. The High Radio Power Population in the Goods-N

NASA Astrophysics Data System (ADS)

Barger, A. J.; Cowie, L. L.; Owen, F. N.; Hsu, L.-Y.; Wang, W.-H.

2017-01-01

We use ultradeep 20 cm data from the Karl G. Jansky Very Large Array and 850 μm data from SCUBA-2 and the Submillimeter Array of an 124 arcmin2 region of the Chandra Deep Field-north to analyze the high radio power ({P}20{cm}> {10}31 erg s-1 Hz-1) population. We find that 20 (42 ± 9%) of the spectroscopically identified z> 0.8 sources have consistent star formation rates (SFRs) inferred from both submillimeter and radio observations, while the remaining sources have lower (mostly undetected) submillimeter fluxes, suggesting that active galactic nucleus (AGN) activity dominates the radio power in these sources. We develop a classification scheme based on the ratio of submillimeter flux to radio power versus radio power and find that it agrees with AGN and star-forming galaxy classifications from Very Long Baseline Interferometry. Our results provide support for an extremely rapid drop in the number of high SFR galaxies above about a thousand solar masses per year (Kroupa initial mass function) and for the locally determined relation between X-ray luminosity and radio power for star-forming galaxies applying at high redshifts and high radio powers. We measure far-infrared (FIR) luminosities and find that some AGNs lie on the FIR-radio correlation, while others scatter below. The AGNs that lie on the correlation appear to do so based on their emission from the AGN torus. We measure a median radio size of 1.″0 ± 0.3 for the star-forming galaxies. The radio sizes of the star-forming galaxies are generally larger than those of the AGNs. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Natural killer cell-based adoptive immunotherapy eradicates and drives differentiation of chemoresistant bladder cancer stem-like cells.

PubMed

Ferreira-Teixeira, Margarida; Paiva-Oliveira, Daniela; Parada, Belmiro; Alves, Vera; Sousa, Vitor; Chijioke, Obinna; Münz, Christian; Reis, Flávio; Rodrigues-Santos, Paulo; Gomes, Célia

2016-10-21

High-grade non-muscle invasive bladder cancer (NMIBC) has a high risk of recurrence and progression to muscle-invasive forms, which seems to be largely related to the presence of tumorigenic stem-like cell populations that are refractory to conventional therapies. Here, we evaluated the therapeutic potential of Natural Killer (NK) cell-based adoptive immunotherapy against chemoresistant bladder cancer stem-like cells (CSCs) in a pre-clinical relevant model, using NK cells from healthy donors and NMIBC patients. Cytokine-activated NK cells from healthy donors and from high-grade NMIBC patients were phenotypically characterized and assayed in vitro against stem-like and bulk differentiated bladder cancer cells. Stem-like cells were isolated from two bladder cancer cell lines using the sphere-forming assay. The in vivo therapeutic efficacy was evaluated in mice bearing a CSC-induced orthotopic bladder cancer. Animals were treated by intravesical instillation of interleukin-activated NK cells. Tumor response was evaluated longitudinally by non-invasive bioluminescence imaging. NK cells from healthy donors upon activation with IL-2 and IL-15 kills indiscriminately both stem-like and differentiated tumor cells via stress ligand recognition. In addition to cell killing, NK cells shifted CSCs towards a more differentiated phenotype, rendering them more susceptible to cisplatin, highlighting the benefits of a possible combined therapy. On the contrary, NK cells from NMIBC patients displayed a low density on NK cytotoxicity receptors, adhesion molecules and a more immature phenotype, losing their ability to kill and drive differentiation of CSCs. The local administration, via the transurethral route, of activated NK cells from healthy donors provides an efficient tumor infiltration and a subsequent robust tumoricidal activity against bladder cancer with high selective cytolytic activity against CSCs, leading to a dramatic reduction in tumor burden from 80 % to complete remission. Although pre-clinical, our results strongly suggest that an immunotherapeutic strategy using allogeneic activated NK cells from healthy donors is effective and should be exploited as a complementary therapeutic strategy in high-risk NMIBC patients to prevent tumor recurrence and progression.

Carbon-based supercapacitors produced by activation of graphene.

PubMed

Zhu, Yanwu; Murali, Shanthi; Stoller, Meryl D; Ganesh, K J; Cai, Weiwei; Ferreira, Paulo J; Pirkle, Adam; Wallace, Robert M; Cychosz, Katie A; Thommes, Matthias; Su, Dong; Stach, Eric A; Ruoff, Rodney S

2011-06-24

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp(2)-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Carbon-Based Supercapacitors Produced by Activation of Graphene

NASA Astrophysics Data System (ADS)

Zhu, Yanwu; Murali, Shanthi; Stoller, Meryl D.; Ganesh, K. J.; Cai, Weiwei; Ferreira, Paulo J.; Pirkle, Adam; Wallace, Robert M.; Cychosz, Katie A.; Thommes, Matthias; Su, Dong; Stach, Eric A.; Ruoff, Rodney S.

2011-06-01

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp2-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Anabolic activity of ursolic acid in bone: Stimulating osteoblast differentiation in vitro and inducing new bone formation in vivo.

PubMed

Lee, Su-Ui; Park, Sang-Joon; Kwak, Han Bok; Oh, Jaemin; Min, Yong Ki; Kim, Seong Hwan

2008-01-01

In the field of osteoporosis, there has been growing interest in anabolic agents that enhance bone mass and improve bone architecture. In this study, we demonstrated that the ubiquitous plant triterpenoid, ursolic acid, enhances differentiation and mineralization of osteoblasts in vitro. We found that ursolic acid induced the expression of osteoblast-specific genes with the activation of mitogen-activated protein kinases, nuclear factor-kappaB, and activator protein-1. Additionally, noggin, an antagonist of bone morphogenetic proteins (BMPs), inhibited ursolic acid-induced osteoblast differentiation. Noggin also inhibited the activation of Smad and the induction of BMP-2 mRNA expression by ursolic acid in the late stage of osteoblast differentiation. Importantly, ursolic acid was shown to have bone-forming activity in vivo in a mouse calvarial bone formation model. A high proportion of positive immunostaining of BMP-2 was found in the nuclear region of woven bone formed by ursolic acid. These results suggested that ursolic acid has the anabolic potential to stimulate osteoblast differentiation and enhance new bone formation.

The application of walking training in the rehabilitation of patients after coronary artery bypass grafting

PubMed Central

Dylewicz, Piotr

2015-01-01

Walking is regarded as one of the most common and utilitarian activities of everyday life. Rehabilitation programs developed on the basis of this form of activity often constitute the primary method of rehabilitating patients after coronary artery bypass grafting. This paper provides a review of literature concerning various forms of walking training, discussing their impact on the parameters of exercise capacity and verifying the training methods with regard to the current guidelines. Attention is drawn to the diversity of the exercise protocols applied during the early and late stages of rehabilitation and pre-rehabilitation programs including: treadmill walking, walking down the corridor, treadmill walking enriched with virtual reality, and walking as an element of training sessions consisting of many different forms of activities. Exercise protocols were also analyzed in terms of their safety, especially in the case of high-intensity interval training. Despite the variety of the available rehabilitation programs, the training methodology requires constant improvement, particularly in terms of load dosage and the supervision of training sessions. PMID:26702291

Amide group anchored glucose oxidase based anodic catalysts for high performance enzymatic biofuel cell

NASA Astrophysics Data System (ADS)

Chung, Yongjin; Ahn, Yeonjoo; Kim, Do-Heyoung; Kwon, Yongchai

2017-01-01

A new enzyme catalyst is formed by fabricating gold nano particle (GNP)-glucose oxidase (GOx) clusters that are then attached to polyethyleneimine (PEI) and carbon nanotube (CNT) with cross-linkable terephthalaldehyde (TPA) (TPA/[CNT/PEI/GOx-GNP]). Especially, amide bonds belonging to TPA play an anchor role for incorporating rigid bonding among GNP, GOx and CNT/PEI, while middle size GNP is well bonded with thiol group of GOx to form strong GNP-GOx cluster. Those bonds are identified by chemical and electrochemical characterizations like XPS and cyclic voltammogram. The anchording effect of amide bonds induces fast electron transfer and strong chemical bonding, resulting in enhancements in (i) catalytic activity, (ii) amount of immobilized GOx and (ii) performance of enzymatic biofuel cell (EBC) including the catalyst. Regarding the catalytic activity, the TPA/[CNT/PEI/GOx-GNP] produces high electron transfer rate constant (6 s-1), high glucose sensitivity (68 μA mM-1 cm-2), high maximum current density (113 μA cm-2), low charge transfer resistance (17.0 Ω cm2) and long-lasting durability while its chemical structure is characterized by XPS confirming large portion of amide bond. In EBC measurement, it has high maximum power density (0.94 mW cm-2) compatible with catalytic acitivity measurements.

Rugged spin-polarized electron sources based on negative electron affinity GaAs photocathode with robust Cs2Te coating

NASA Astrophysics Data System (ADS)

Bae, Jai Kwan; Cultrera, Luca; DiGiacomo, Philip; Bazarov, Ivan

2018-04-01

Photocathodes capable of providing high intensity and highly spin-polarized electron beams with long operational lifetimes are of great interest for the next generation nuclear physics facilities like Electron Ion Colliders. We report on GaAs photocathodes activated by Cs2Te, a material well known for its robustness. GaAs activated by Cs2Te forms Negative Electron Affinity, and the lifetime for extracted charge is improved by a factor of 5 compared to that of GaAs activated by Cs and O2. The spin polarization of photoelectrons was measured using a Mott polarimeter and found to be independent from the activation method, thereby shifting the paradigm on spin-polarized electron sources employing photocathodes with robust coatings.

Positive And Negative Feedback Loops Coupled By Common Transcription Activator And Repressor

NASA Astrophysics Data System (ADS)

Sielewiesiuk, Jan; Łopaciuk, Agata

2015-03-01

Dynamical systems consisting of two interlocked loops with negative and positive feedback have been studied using the linear analysis of stability and numerical solutions. Conditions for saddle-node bifurcation were formulated in a general form. Conditions for Hopf bifurcations were found in a few symmetrical cases. Auto-oscillations, when they exist, are generated by the negative feedback repressive loop. This loop determines the frequency and amplitude of oscillations. The positive feedback loop of activation slightly modifies the oscillations. Oscillations are possible when the difference between Hilll's coefficients of the repression and activation is sufficiently high. The highly cooperative activation loop with a fast turnover slows down or even makes the oscillations impossible. The system under consideration can constitute a component of epigenetic or enzymatic regulation network.

High Efficiency Latency and Activation of Herpes Simplex Virus in Human Cells

NASA Astrophysics Data System (ADS)

Wigdahl, Brian L.; Scheck, Adrienne C.; de Clercq, Erik; Rapp, Fred

1982-09-01

Herpes simplex virus (HSV) exists in humans in a latent form that can be activated. To characterize the molecular basis of the cell-virus interactions and to analyze the state of the latent HSV genome, an in vitro model system was established. In this system a large fraction of the latently infected cells contain an HSV genome that can be activated. Cell survival was reduced minimally after repression of high multiplicity HSV type 1 (HSV-1) infection of human fibroblast cells with (E)-5-(2-bromovinyl)-2'-deoxyuridine in combination with human leukocyte interferon (IFN-α ). A minimum of 1 to 3 percent of the surviving cells contained an HSV genome that could be activated either by human cytomegalovirus superinfection or reduction in incubation temperature.

PhosphoLipid transfer protein (PLTP) exerts a direct pro-inflammatory effect on rheumatoid arthritis (RA) fibroblasts-like-synoviocytes (FLS) independently of its lipid transfer activity

PubMed Central

Deckert, Valérie; Daien, Claire I.; Che, Hélène; Elhmioui, Jamila; Lemaire, Stéphanie; Pais de Barros, Jean-Paul; Desrumaux, Catherine; Combe, Bernard; Hahne, Michael; Lagrost, Laurent; Morel, Jacques

2018-01-01

Rheumatoid arthritis (RA) is a chronic inflammatory rheumatic disease with modification of lipids profile and an increased risk of cardiovascular events related to inflammation. Plasma phospholipid transfer protein (PLTP) exerts a lipid transfer activity through its active form. PLTP can also bind to receptors such as ATP-binding cassette transporter A1 (ABCA1). In addition to its role in lipoprotein metabolism and atherosclerosis, the latest advances came in support of a complex role of PLTP in the regulation of the inflammatory response, both with pro-inflammatory or anti-inflammatory properties. The aim of the present study was to decipher the role of PLTP in joint inflammation and to assess its relevance in the context of RA. PLTP expression was examined by western-blot and by immunochemistry. ABCA1 expression was analyzed by flow cytometry. Lipid transfer activity of PLTP and pro-inflammatory cytokines were measured in sera and synovial fluid (SF) from RA patients and controls (healthy subjects or osteoarthritis patients [OA]). FLS were treated with both lipid-transfer active form and inactive form of recombinant human PLTP. IL-8, IL-6, VEGF and MMP3 produced by FLS were assessed by ELISA, and proliferation by measuring 3H-Thymidine incorporation. RA synovial tissues showed higher PLTP staining than OA and PLTP protein levels were also significantly higher in RA-FLS. In addition, RA, unlike OA patients, displayed elevated levels of PLTP activity in SF, which correlated with pro-inflammatory cytokines. Both lipid-transfer active and inactive forms of PLTP significantly increased the production of cytokines and proliferation of FLS. ABCA1 was expressed on RAFLS and PLTP activated STAT3 pathway. To conclude, PLTP is highly expressed in the joints of RA patients and may directly trigger inflammation and FLS proliferation, independently of its lipid transfer activity. These results suggest a pro-inflammatory role for PLTP in RA. PMID:29565987

Radon progeny in hydrometeors at the earth's surface.

PubMed

Voltaggio, M

2012-07-01

During atmospheric thermal inversions, dew and hoarfrost concentrate gamma emitting radionuclides of the short-lived (222)Rn progeny ((214)Pb and (214)Bi), causing an increase in the total natural gamma background from the ground. To highlight this phenomenon, a volcanic zone of high (222)Rn flux was studied during the winter season 2010-11. High-specific short-lived radon progeny activities up to 122 Bq g(-1) were detected in hydrometeors forming at the earth's surface (ESHs), corresponding to a mean increase of up to 17 % of the normal gamma background value. A theoretical model, depending on radon flux from soil and predicting the radon progeny concentrations in hydrometeors forming at the ESHs is presented. The comparison between model and field data shows a good correspondence. Around nuclear power plants or in nuclear facilities that use automatic NaI or CsI total gamma spectroscopy systems for monitoring radioactive contamination, hydrometeors forming at the ESHs in sites with a high radon flux could represent a relevant source of false alarms of radioactive contamination.

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

PubMed Central

Jouffroy, Matthieu; Gramage-Doria, Rafael; Sémeril, David; Oberhauser, Werner; Toupet, Loïc

2014-01-01

Summary The capacity of two cavity-shaped ligands, HUGPHOS-1 and HUGPHOS-2, to generate exclusively singly phosphorus-ligated complexes, in which the cyclodextrin cavity tightly wraps around the metal centre, was explored with a number of late transition metal cations. Both cyclodextrin-derived ligands were assessed in palladium-catalysed Mizoroki–Heck coupling reactions between aryl bromides and styrene on one hand, and the rhodium-catalysed asymmetric hydroformylation of styrene on the other hand. The inability of both chiral ligands to form standard bis(phosphine) complexes under catalytic conditions was established by high-pressure NMR studies and shown to have a deep impact on the two carbon–carbon bond forming reactions both in terms of activity and selectivity. For example, when used as ligands in the rhodium-catalysed hydroformylation of styrene, they lead to both high isoselectivity and high enantioselectivity. In the study dealing with the Mizoroki–Heck reactions, comparative tests were carried out with WIDEPHOS, a diphosphine analogue of HUGPHOS-2. PMID:25383109

Surface hole gas enabled transparent deep ultraviolet light-emitting diode

NASA Astrophysics Data System (ADS)

Zhang, Jianping; Gao, Ying; Zhou, Ling; Gil, Young-Un; Kim, Kyoung-Min

2018-07-01

The inherent deep-level nature of acceptors in wide-band-gap semiconductors makes p-ohmic contact formation and hole supply difficult, impeding progress for short-wavelength optoelectronics and high-power high-temperature bipolar electronics. We provide a general solution by demonstrating an ultrathin rather than a bulk wide-band-gap semiconductor to be a successful hole supplier and ohmic contact layer. Free holes in this ultrathin semiconductor are assisted to activate from deep acceptors and swept to surface to form hole gases by a large electric field, which can be provided by engineered spontaneous and piezoelectric polarizations. Experimentally, a 6 nm thick AlN layer with surface hole gas had formed p-ohmic contact to metals and provided sufficient hole injection to a 280 nm light-emitting diode, demonstrating a record electrical-optical conversion efficiency exceeding 8.5% at 20 mA (55 A cm‑2). Our approach of forming p-type wide-band-gap semiconductor ohmic contact is critical to realizing high-efficiency ultraviolet optoelectronic devices.

Brazilian Cerrado Qualea grandiflora Mart. Leaves Exhibit Antiplasmodial and Trypanocidal Activities In vitro

PubMed Central

Cordeiro, Thuany de Moura; Borghetti, Fabian; Caldas Oliveira, Sarah C.; Bastos, Izabela Marques Dourado; de Santana, Jaime Martins; Grellier, Philippe; Charneau, Sébastien

2017-01-01

Background: The rapid spread of drug-resistant strains of protozoan parasites required the urgent need for new effective drugs. Natural products offer a variety of chemical structures, which make them a valuable source of lead compounds for the development of such new drugs. Cerrado is the second largest biome in Brazil and has the richest flora of all the world savannahs. We selected Qualea grandiflora, a plant species known for its proprieties in folk medicine and its antibacterial activity. Objective: However, its antiprotozoal activity was not yet explored. Materials and Methods: We investigated the activities of fractions from the ethyl acetate extract of Q. grandiflora leaves against human life forms of Plasmodium falciparum, Trypanosoma cruzi, and Trypanosoma brucei gambiense, and for its cytotoxicity upon the rat L6-myoblast cell line. Ten fractions were produced by ethyl acetate:hexane chromatography. Results and Conclusion: The fractions showed no cytotoxicity against L-6 cells (IC50 > 100 μg/mL) and no hemolysis propriety. Three fractions had a moderate activity against P. falciparum, anyone was active against T. cruzi but four fractions demonstrated a high activity against bloodstream forms of T. brucei gambiense (8.0< IC50 <15 μg/mL). Identification and characterization of the active compounds are currently under investigation. SUMMARY Qualea grandiflora is an endemic tree of the Brazilian Cerrado, which presents medicinal propertiesTen fractions of the ethyl acetate extract of Q. grandiflora leaves were assessed against Plasmodium falciparum, Trypanosoma Cruzi, and Trypanosoma brucei gambienseNo fraction showed relevant cytotoxicity and hemolysis activityAll the fractions presented antiplasmodial and trypanocidal activitiesThree fractions with moderate antiplasmodial activity (49< IC50 <56 μg/mL)Four fractions with high activity against bloodstream forms of T. brucei gambiense (8.0< IC50 <15 μg/mL). Abbreviations used: CQ: Chloroquine, DMSO: Dimethyl sulfoxide, HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, HMI: Modified Iscove's medium, IC50: Concentration inhibiting 50% of parasite growth, IC90: Concentration inhibiting 90% of parasite growth, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, RPMI: Roswell Park Memorial Institute, SD: Standard deviation, SI: Ratio of cytotoxicity to biological activity − TC50/IC50, TC50: Concentration causing 50% of cell growth inhibition, TC90: Concentration causing 90% of cell growth inhibition, TLC: Thin-layer chromatography PMID:29200731

Brazilian Cerrado Qualea grandiflora Mart. Leaves Exhibit Antiplasmodial and Trypanocidal Activities In vitro.

PubMed

Cordeiro, Thuany de Moura; Borghetti, Fabian; Caldas Oliveira, Sarah C; Bastos, Izabela Marques Dourado; de Santana, Jaime Martins; Grellier, Philippe; Charneau, Sébastien

2017-01-01

The rapid spread of drug-resistant strains of protozoan parasites required the urgent need for new effective drugs. Natural products offer a variety of chemical structures, which make them a valuable source of lead compounds for the development of such new drugs. Cerrado is the second largest biome in Brazil and has the richest flora of all the world savannahs. We selected Qualea grandiflora , a plant species known for its proprieties in folk medicine and its antibacterial activity. However, its antiprotozoal activity was not yet explored. We investigated the activities of fractions from the ethyl acetate extract of Q. grandiflora leaves against human life forms of Plasmodium falciparum , Trypanosoma cruzi , and Trypanosoma brucei gambiense , and for its cytotoxicity upon the rat L6-myoblast cell line. Ten fractions were produced by ethyl acetate:hexane chromatography. The fractions showed no cytotoxicity against L-6 cells (IC 50 > 100 μg/mL) and no hemolysis propriety. Three fractions had a moderate activity against P. falciparum , anyone was active against T. cruzi but four fractions demonstrated a high activity against bloodstream forms of T. brucei gambiense (8.0< IC 50 <15 μg/mL). Identification and characterization of the active compounds are currently under investigation. Qualea grandiflora is an endemic tree of the Brazilian Cerrado, which presents medicinal propertiesTen fractions of the ethyl acetate extract of Q. grandiflora leaves were assessed against Plasmodium falciparum , Trypanosoma Cruzi , and Trypanosoma brucei gambiense No fraction showed relevant cytotoxicity and hemolysis activityAll the fractions presented antiplasmodial and trypanocidal activitiesThree fractions with moderate antiplasmodial activity (49< IC 50 <56 μg/mL)Four fractions with high activity against bloodstream forms of T. brucei gambiense (8.0< IC 50 <15 μg/mL). Abbreviations used: CQ: Chloroquine, DMSO: Dimethyl sulfoxide, HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, HMI: Modified Iscove's medium, IC 50 : Concentration inhibiting 50% of parasite growth, IC 90 : Concentration inhibiting 90% of parasite growth, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, RPMI: Roswell Park Memorial Institute, SD: Standard deviation, SI: Ratio of cytotoxicity to biological activity - TC 50 /IC 50 , TC 50 : Concentration causing 50% of cell growth inhibition, TC 90 : Concentration causing 90% of cell growth inhibition, TLC: Thin-layer chromatography.

Rapid intranasal delivery of chloramphenicol acetyltransferase in the active form to different brain regions as a model for enzyme therapy in the CNS.

PubMed

Appu, Abhilash P; Arun, Peethambaran; Krishnan, Jishnu K S; Moffett, John R; Namboodiri, Aryan M A

2016-02-01

The blood brain barrier (BBB) is critical for maintaining central nervous system (CNS) homeostasis by restricting entry of potentially toxic substances. However, the BBB is a major obstacle in the treatment of neurotoxicity and neurological disorders due to the restrictive nature of the barrier to many medications. Intranasal delivery of active enzymes to the brain has therapeutic potential for the treatment of numerous CNS enzyme deficiency disorders and CNS toxicity caused by chemical threat agents. The aim of this work is to provide a sensitive model system for analyzing the rapid delivery of active enzymes into various regions of the brain with therapeutic bioavailability. We tested intranasal delivery of chloramphenicol acetyltransferase (CAT), a relatively large (75kD) enzyme, in its active form into different regions of the brain. CAT was delivered intranasally to anaesthetized rats and enzyme activity was measured in different regions using a highly specific High Performance Thin Layer Chromatography (HP-TLC)-radiometry coupled assay. Active enzyme reached all examined areas of the brain within 15min (the earliest time point tested). In addition, the yield of enzyme activity in the brain was almost doubled in the brains of rats pre-treated with matrix metalloproteinase-9 (MMP-9). Intranasal administration of active enzymes in conjunction with MMP-9 to the CNS is both rapid and effective. The present results suggest that intranasal enzyme therapy is a promising method for counteracting CNS chemical threat poisoning, as well as for treating CNS enzyme deficiency disorders. Published by Elsevier B.V.

Developmental differences in masked form priming are not driven by vocabulary growth.

PubMed

Bhide, Adeetee; Schlaggar, Bradley L; Barnes, Kelly Anne

2014-01-01

As children develop into skilled readers, they are able to more quickly and accurately distinguish between words with similar visual forms (i.e., they develop precise lexical representations). The masked form priming lexical decision task is used to test the precision of lexical representations. In this paradigm, a prime (which differs by one letter from the target) is briefly flashed before the target is presented. Participants make a lexical decision to the target. Primes can facilitate reaction time by partially activating the lexical entry for the target. If a prime is unable to facilitate reaction time, it is assumed that participants have a precise orthographic representation of the target and thus the prime is not a close enough match to activate its lexical entry. Previous developmental work has shown that children and adults' lexical decision times are facilitated by form primes preceding words from small neighborhoods (i.e., very few words can be formed by changing one letter in the original word; low N words), but only children are facilitated by form primes preceding words from large neighborhoods (high N words). It has been hypothesized that written vocabulary growth drives the increase in the precision of the orthographic representations; children may not know all of the neighbors of the high N words, making the words effectively low N for them. We tested this hypothesis by (1) equating the effective orthographic neighborhood size of the targets for children and adults and (2) testing whether age or vocabulary size was a better predictor of the extent of form priming. We found priming differences even when controlling for effective neighborhood size. Furthermore, age was a better predictor of form priming effects than was vocabulary size. Our findings provide no support for the hypothesis that growth in written vocabulary size gives rise to more precise lexical representations. We propose that the development of spelling ability may be a more important factor.

Experimental investigation of active rib stitch knitted architecture for flow control applications

NASA Astrophysics Data System (ADS)

Abel, Julianna M.; Mane, Poorna; Pascoe, Benjamin; Luntz, Jonathan; Brei, Diann

2010-04-01

Actively manipulating flow characteristics around the wing can enhance the high-lift capability and reduce drag; thereby, increasing fuel economy, improving maneuverability and operation over diverse flight conditions which enables longer, more varied missions. Active knits, a novel class of cellular structural smart material actuator architectures created by continuous, interlocked loops of stranded active material, produce distributed actuation that can actively manipulate the local surface of the aircraft wing to improve flow characteristics. Rib stitch active knits actuate normal to the surface, producing span-wise discrete periodic arrays that can withstand aerodynamic forces while supplying the necessary displacement for flow control. This paper presents a preliminary experimental investigation of the pressuredisplacement actuation performance capabilities of a rib stitch active knit based upon shape memory alloy (SMA) wire. SMA rib stitch prototypes in both individual form and in stacked and nestled architectures were experimentally tested for their quasi-static load-displacement characteristics, verifying the parallel and series relationships of the architectural configurations. The various configurations tested demonstrated the potential of active knits to generate the required level of distributed surface displacements while under aerodynamic level loads for various forms of flow control.

The COUP-TFs compose a family of functionally related transcription factors

PubMed Central

Wang, Lee-Ho; Ing, Nancy H.; Tsai, Sophia Y.; O’Malley, Bert W.; Tsai, Ming-Jer

1991-01-01

The chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are members of the steroid/thyroid hormone receptor superfamily and function in transcriptional regulation of a wide variety of genes. The COUP-TFs purified from HeLa nuclear extract by COUP-affinity chromatography are composed of multiple Mr forms. The Low Mr COUP-TFs (43,000, 44,000, 46,000, and 47,000 Mr) produce a relatively fast migrating complex (Cl) with DNA in electrophoresis mobility shift assays, while the high Mr forms (66,000, 68,000, 72,000, and 74,000 Mr) produce a slower migrating (C2) complex. The high Mr COUP-TFs were purified by gel filtration chromatography and independently formed the C2 DNA complex, probably acting as dimers. The high Mr forms are indistinguishable from the low Mr COUP-TFs in DNA binding and in enhancement of in vitro transcription from the ovalbumin promoter. The finding of multiple COUP-TF forms led us to clone a second low Mr COUP-TF, “COUP-TF2.” The COUP-TF2 sequence has very strong homology with COUP-TF1. The N-termini of COUP-TF1 and COUP-TF2 are least similar, but both contain glutamine-rich and proline-rich motifs, putative activation domains. PMID:1820218

A rational design approach to nanostructured catalysts for the oxidation of carbon monoxide

NASA Astrophysics Data System (ADS)

Karwacki, Christopher

The extraordinary energetic properties of subnanometer (<10 nm) structures consisting of reduced metals, metal oxides, and graphitic carbons are emerging as the principal technologies involving catalytic reactions at ambient temperatures, for such applications as respiratory protection, pollution abatement, chemical synthesis, sensors, and energy conversion. Gold nanoparticles (Au NP) possess unique reactive properties not present in the bulk state and have served in the past decade as a model for the nanosciences, where molecular species are synthesized, scaled, and engineered into functional materials. Gold nanoparticles as isolated structures are not useful as real catalysts and must co-exist with supports that provide enhanced stability and activity. Support oxides such as TiO2, Fe2O 3, CeO2, SiO2, Al2O3, ZrO 2, and graphitic (active) carbons have been shown to increase the active nature of AuNP and have been the subject of several thousand publications in the past decade. Zirconia compared to titania as a support for Au NP catalysis has been studied with limited success. In fact, the majority of observations show that zirconia is one of the lowest performing metal oxide supports involving Au NP oxidation catalysis. The likely reason for these observations is a lack of understanding of the relationship between structure and surface functionality as it pertains to ambient temperature oxidation catalysis (ATOC). Furthermore, virtually all substrate and catalyst preparations in earlier work were performed at high temperatures, typically 400--900°C, thus forming progressively monomorphic structures containing larger crystals with reduced surface functionality and porosity. In this research, I established the hypothesis based on a structural model that surface functional hydroxides are important to sustained hydrolytic reactions, such as those involving Au NP for the oxidation of CO to CO 2. Theoretical calculations by Ignatchenko, Vittadini, et al. show that zirconia readily dissociates adsorbed water on the most active and stable crystal structures (111) compared to other metal oxides, such as the common anatase (101) form of titania. Also, the support must provide a source of activated oxygen as a means to oxidize intermediate carbonates with CO 2 formation. The role of the support is to provide lattice oxygen in an activated state (O2-) for oxidation of adsorbed CO the Au NP:support interface. Furthermore, the primary interest is the energy associated Au NP in proximity to the support surface. Advancing the understanding of this region is believed to be crucial to the future design of active nanostructured materials that function under ambient conditions. The proposed model involves a structure consisting of properly sized and highly dispersed Au NP supported on a hydroxylated form of nanocrystalline zirconia. This type of zirconia is in a highly polymorphic form consisting of aggregates of small crystals less than 10 nm. The structure is highly porous, containing undercoordinated zirconium atoms, and provides an environment for rapid dissociation of molecular water. In this research and in collaboration with Mogilevsky et al., 37 I introduce a novel method for quantifying the surface concentration of two major forms of hydroxide that form on zirconia. Furthermore, in this research I show how both the porosity of the zirconia support and the size of the crystalline aggregates affect the type and surface concentration of hydroxyl groups. This relationship is thus directly related to the oxidation activity of the catalyst consisting of Au NP supported on hydroxylated ZrO 2. These phenomena are exemplified by a reduction in structural porosity and surface hydroxyl groups with increasing temperature treatments of the zirconia support. Gold NP and ZrO2 supports were extended to studies that included interactions with activated carbons. This work was done on the premise that graphitic carbons, based on their tunable porosities and surface chemistries, can enhance or stabilize the catalytic activity of neighboring Au NP. Gold dispersed on active carbon and hybrid structures consisting of Au/ZrO 2/C shows interesting properties, which lend themselves to catalytic particle stabilization and to the advancement of multifunctional material design.

An Easy Synthesis of Two Cage Hydrocarbons.

ERIC Educational Resources Information Center

Dong, Dao Cong

1982-01-01

Describes a simple, three-step synthesis of two cage molecules, birdcage hydrocarbon (VIII) and its homologue, the homobirdcage hydrocarbon IX. Indicates that all products are easily purified and formed in high yields in this activity suitable for advanced undergraduate laboratory courses. (Author/JN)

Effect of a sport education program on motivation for physical education and leisure-time physical activity.

PubMed

Wallhead, Tristan L; Garn, Alex C; Vidoni, Carla

2014-12-01

The purpose of this study was to examine the effect of a high school sport education curriculum program on students' motivation for physical education and leisure-time physical activity. Participants were 568 high school students enrolled in the required physical education programs at 2 schools, 1 taught using sport education and the 2nd using a multiactivity model of instruction. A motivational profile survey, which included student psychological need satisfaction, autonomous motives, perceived effort and enjoyment in physical education, and physical activity intention and behavior, was completed by all participants prior to and at the end of the 2-year physical education program. Mixed-model analysis of variance tests revealed that the students in the sport education program reported greater increases in perceived effort and enjoyment of the program compared with the students taught within the multiactivity model. Hierarchical multiple regression analyses showed that these positive affective outcomes were facilitated by the development of more autonomous forms of motivation. RESULTS revealed limited support for the direct transfer of motivation from a sport education program to increases in leisure-time physical activity behavior. Sport education facilitates more internalized forms of student motivation in required physical education programs, but without the provision of an appropriately designed extracurricular outlet, the potential of transfer to leisure-time physical activity may not be achieved.

Pandemic pharmaceutical dosing effects on wastewater treatment: no adaptation of activated sludge bacteria to degrade the antiviral drug oseltamivir (Tamiflu®) and loss of nutrient removal performance.

PubMed

Slater, Frances R; Singer, Andrew C; Turner, Susan; Barr, Jeremy J; Bond, Philip L

2011-02-01

The 2009-2010 influenza pandemic saw many people treated with antivirals and antibiotics. High proportions of both classes of drugs are excreted and enter wastewater treatment plants (WWTPs) in biologically active forms. To date, there has been no study into the potential for influenza pandemic-scale pharmaceutical use to disrupt WWTP function. Furthermore, there is currently little indication as to whether WWTP microbial consortia can degrade antiviral neuraminidase inhibitors when exposed to pandemic-scale doses. In this study, we exposed an aerobic granular sludge sequencing batch reactor, operated for enhanced biological phosphorus removal (EBPR), to a simulated influenza-pandemic dosing of antibiotics and antivirals for 8 weeks. We monitored the removal of the active form of Tamiflu(®), oseltamivir carboxylate (OC), bacterial community structure, granule structure and changes in EBPR and nitrification performance. There was little removal of OC by sludge and no evidence that the activated sludge community adapted to degrade OC. There was evidence of changes to the bacterial community structure and disruption to EBPR and nitrification during and after high-OC dosing. This work highlights the potential for the antiviral contamination of receiving waters and indicates the risk of destabilizing WWTP microbial consortia as a result of high concentrations of bioactive pharmaceuticals during an influenza pandemic. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

PubMed

Wang, Long-Feng; Rhim, Jong-Whan

2015-09-01

Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

Material and structural characterization of alkali activated low-calcium brown coal fly ash.

PubMed

Skvára, Frantisek; Kopecký, Lubomír; Smilauer, Vít; Bittnar, Zdenek

2009-09-15

The waste low-calcium Czech brown coal fly ash represents a considerable environmental burden due to the quantities produced and the potentially high content of leachable heavy metals. The heterogeneous microstucture of the geopolymer M(n) [-(Si-O)(z)-Al-O](n).wH(2)O, that forms during the alkaline activation, was examined by means of microcalorimetry, XRD, TGA, DSC, MIP, FTIR, NMR MAS ((29)Si, (27)Al, (23)Na), ESEM, EDS, and EBSD. The leaching of heavy metals and the evolution of compressive strength were also monitored. The analysis of raw fly ash identified a number of different morphologies, unequal distribution of elements, Fe-rich rim, high internal porosity, and minor crystalline phases of mullite and quartz. Microcalorimetry revealed exothermic reactions with dependence on the activator alkalinity. The activation energy of the geopolymerization process was determined as 86.2kJ/mol. The X-ray diffraction analysis revealed no additional crystalline phases associated with geopolymer formation. Over several weeks, the (29)Si NMR spectrum testified a high degree of polymerization and Al penetration into the SiO(4) tetrahedra. The (23)Na NMR MAS spectrum hypothesized that sodium is bound in the form of Na(H(2)O)(n) rather than Na(+), thus causing efflorescence in a moisture-gradient environment. As and Cr(6+) are weakly bonded in the geopolymer matrix, while excellent immobilization of Zn(2+), Cu(2+), Cd(2+), and Cr(3+) are reported.

Galantamine is a Novel Post-Exposure Therapeutic Against Lethal VX Challenge

DTIC Science & Technology

2009-01-01

administered as a post- exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality...The standard U.S. military therapy for intoxication by anticholinesterase agents consists of administering ATR to antagonize excessive muscarinic...2003). A ball-and-stick repre- sentation of GAL is shown in Fig. 1 docking to the active site of two different acetylcholinesterase forms. GAL

High pressure chemistry of red phosphorus by photo-activated simple molecules

NASA Astrophysics Data System (ADS)

Ceppatelli, M.; Fanetti, S.; Bini, R.; Caporali, M.; Peruzzini, M.

2014-05-01

High pressure (HP) is very effective in reducing intermolecular distances and inducing unexpected chemical reactions. In addition the photo-activation of the reactants in HP conditions can lead to very efficient and selective processes. The chemistry of phosphorus is currently based on the white molecular form. The red polymeric allotrope, despite more stable and much less toxic, has not attracted much attention so far. However, switching from the white to the red form would benefit any industrial procedure, especially from an environmental point of view. On the other side, water and ethanol are renewable, environmental friendly and largely available molecules, usable as reactants and photo-activators in HP conditions. Here we report a study on the HP photo-induced reactivity of red phosphorus with water and ethanol, showing the possibility of very efficient and selective processes, leading to molecular hydrogen and valuable phosphorus compounds. The reactions have been studied by means of FTIR and Raman spectroscopy and pressure has been generated using membrane Diamond (DAC) and Sapphire (SAC) anvil cells. HP reactivity has been activated by the two-photon absorption of near-UV wavelengths and occurred in total absence of solvents, catalysts and radical initiators, at room T and mild pressure conditions (0.2-1.5 GPa).

[Socio-cultural aspects regarding the perception of quality of life amongst people engaging in extreme (high-risk) sports].

PubMed

Pimentel, Giuliano Gomes de Assis

2008-01-01

Considering the search for adventure activities as a form of improving life quality, the present paper aimed at analyzing the perception of some dimensions of that category among hang-gliding apprentices. A questionnaire was applied to 30 brasilians hang-gliding and paragliding apprentices in order to identify aspects such as, physical activity, preventive behavior, nutrition, stress control and social relationships. Comparing results with the ones found in other adventure sports, it was observed that flyers adopt a competitive and risky behavior, not showing good results in relation to affectionate relationships and physical exercises. On the other hand, all of them are considered as wealthy and more used to dealing with stress. Even not possessing good physical conditioning, individuals practice flight just due to their technical knowledge and the dominium of technology Thus, apprentices use those sport tensions as a form of training the stress control in risky situations. Regarding mental health, activities of active leisure are highly recommended as an escape valve to stress. The group studied showed that besides increasing the tolerance to stress, generated by risky situations, individuals went beyond, once it was observed that the risks of such sport have turned the individuals into more and more insensitive to the professional life pressure.

Cocaine-conditioned odor cues without chronic exposure: Implications for the development of addiction vulnerability.

PubMed

Lowen, Steven B; Rohan, Michael L; Gillis, Timothy E; Thompson, Britta S; Wellons, Clara B W; Andersen, Susan L

2015-01-01

Adolescents are highly vulnerable to addiction and are four times more likely to become addicted at first exposure than at any other age. The dopamine D1 receptor, which is typically overexpressed in the normal adolescent prefrontal cortex, is involved in drug cue responses and is associated with relapse in animal models. In human drug addicts, imaging methods have detected increased activation in response to drug cues in reward- and habit-associated brain regions. These same methods can be applied more quantitatively to rodent models. Here, changes in neuronal activation in response to cocaine-conditioned cues were observed using functional magnetic resonance imaging in juvenile rats that were made to over-express either D1 receptors or green fluorescent protein by viral-mediated transduction. Reduced activation was observed in the amygdala and dopamine cell body regions in the low cue-preferring/control juvenile rats in response to cocaine cues. In contrast, increased activation was observed in the dorsal striatum, nucleus accumbens, prefrontal cortex, and dopamine cell bodies in high cue-preferring/D1 juveniles. The increase in cue salience that is mediated by increased D1 receptor density, rather than excessive cocaine experience, appears to underlie the transition from aversion to reward in cue-induced neural response and may form the basis for habit-forming vulnerability.

Earth Observation

NASA Image and Video Library

2013-06-11

ISS036-E-007165 (11 June 2013) --- Nevados de Chillan, Chile is featured in this image photographed by an Expedition 36 crew member on the International Space Station. This photograph highlights a large volcanic area located near the Chile-Argentina border. Like other historically active volcanoes in the central Andes ranges, the Nevados de Chillan were created by upwelling magma generated by eastward subduction of the dense oceanic crust of the Pacific basin beneath the less dense continental crust of South America. Rising magmas associated with this type of tectonic environment frequently erupt explosively, forming widespread ash and ignimbrite layers. They can also produce less explosive eruptions that form voluminous lava flows – layering together with explosively erupted deposits to build the classic cone-shaped edifice of a stratovolcano over geologic time. The Nevados de Chillan includes three distinct volcanic structures, built within three overlapping calderas that extend along a north-northwest to south-southeast line. The snow-capped volcanic complex sits within the glaciated terrain of the central Andes – glacial valleys are visible at upper left, upper right, and lower right. The northwestern end of the chain is occupied by the 3,212-meter-high Cerro Blanco (also known as Volcan Nevado). The 3,089-meter-high Volcan Viejo (also known as Volcan Chillan) sits at the southeastern end; this volcano was active during the 17th-19th centuries. A group of lava domes known as Volcan Nuevo formed to the northwest of Volcan Viejo between 1906-1945, followed by an even younger dome complex that formed between 1973-1986 (Volcan Arrau; not indicated on the image). The last reported volcanic activity at Nevados de Chillan took place in 2009 (according to the Smithsonian Institution’s Global Volcanism Network).

Reporter enzyme inhibitor study to aid assembly of orthogonal reporter gene assays.

PubMed

Ho, Pei-i; Yue, Kimberley; Pandey, Pramod; Breault, Lyne; Harbinski, Fred; McBride, Aaron J; Webb, Brian; Narahari, Janaki; Karassina, Natasha; Wood, Keith V; Hill, Adam; Auld, Douglas S

2013-05-17

Reporter gene assays (RGAs) are commonly used to measure biological pathway modulation by small molecules. Understanding how such compounds interact with the reporter enzyme is critical to accurately interpret RGA results. To improve our understanding of reporter enzymes and to develop optimal RGA systems, we investigated eight reporter enzymes differing in brightness, emission spectrum, stability, and substrate requirements. These included common reporter enzymes such as firefly luciferase (Photinus pyralis), Renilla reniformis luciferase, and β-lactamase, as well as mutated forms of R. reniformis luciferase emitting either blue- or green-shifted luminescence, a red-light emitting form of Luciola cruciata firefly luciferase, a mutated form of Gaussia princeps luciferase, and a proprietary luciferase termed "NanoLuc" derived from the luminescent sea shrimp Oplophorus gracilirostris. To determine hit rates and structure-activity relationships, we screened a collection of 42,460 PubChem compounds at 10 μM using purified enzyme preparations. We then compared hit rates and chemotypes of actives for each enzyme. The hit rates ranged from <0.1% for β-lactamase to as high as 10% for mutated forms of Renilla luciferase. Related luciferases such as Renilla luciferase mutants showed high degrees of inhibitor overlap (40-70%), while unrelated luciferases such as firefly luciferases, Gaussia luciferase, and NanoLuc showed <10% overlap. Examination of representative inhibitors in cell-based assays revealed that inhibitor-based enzyme stabilization can lead to increases in bioluminescent signal for firefly luciferase, Renilla luciferase, and NanoLuc, with shorter half-life reporters showing increased activation responses. From this study we suggest strategies to improve the construction and interpretation of assays employing these reporter enzymes.

Transformation Stasis Phenomenon of Bainite Formation in Low-Carbon, Multicomponent Alloyed Steel

NASA Astrophysics Data System (ADS)

Lan, Liangyun; Kong, Xiangwei

2017-11-01

The transformation stasis phenomenon of bainite formation in low-carbon steel was detected using a high-resolution dilatometer. The phenomenon occurred at different stages for different isothermal temperatures. In combination with microstructural observation, the calculated overall activation energy of transformation and interface migration velocity shed new light on the cause of formation of the stasis phenomenon. The temporary stasis formed at the initial stage of phase transformation for high isothermal temperature was attributed to the drag effect of substitutional atoms, which leads to low-interface migration velocity and large overall activation energy.

All-fiber, long-active-length Fabry-Perot strain sensor.

PubMed

Pevec, Simon; Donlagic, Denis

2011-08-01

This paper presents a high-sensitivity, all-silica, all-fiber Fabry-Perot strain-sensor. The proposed sensor provides a long active length, arbitrary length of Fabry-Perot cavity, and low intrinsic temperature sensitivity. The sensor was micro-machined from purposely-developed sensor-forming fiber that is etched and directly spliced to the lead-in fiber. This manufacturing process has good potential for cost-effective, high-volume production. Its measurement range of over 3000 µε, and strain-resolution better than 1 µε were demonstrated by the application of a commercial, multimode fiber-based signal processor.

Intrinsic and extrinsic motivators of attachment under active inference.

PubMed

Cittern, David; Nolte, Tobias; Friston, Karl; Edalat, Abbas

2018-01-01

This paper addresses the formation of infant attachment types within the context of active inference: a holistic account of action, perception and learning in the brain. We show how the organised forms of attachment (secure, avoidant and ambivalent) might arise in (Bayesian) infants. Specifically, we show that these distinct forms of attachment emerge from a minimisation of free energy-over interoceptive states relating to internal stress levels-when seeking proximity to caregivers who have a varying impact on these interoceptive states. In line with empirical findings in disrupted patterns of affective communication, we then demonstrate how exteroceptive cues (in the form of caregiver-mediated AMBIANCE affective communication errors, ACE) can result in disorganised forms of attachment in infants of caregivers who consistently increase stress when the infant seeks proximity, but can have an organising (towards ambivalence) effect in infants of inconsistent caregivers. In particular, we differentiate disorganised attachment from avoidance in terms of the high epistemic value of proximity seeking behaviours (resulting from the caregiver's misleading exteroceptive cues) that preclude the emergence of coherent and organised behavioural policies. Our work, the first to formulate infant attachment in terms of active inference, makes a new testable prediction with regards to the types of affective communication errors that engender ambivalent attachment.

Intrinsic and extrinsic motivators of attachment under active inference

PubMed Central

Nolte, Tobias; Friston, Karl; Edalat, Abbas

2018-01-01

This paper addresses the formation of infant attachment types within the context of active inference: a holistic account of action, perception and learning in the brain. We show how the organised forms of attachment (secure, avoidant and ambivalent) might arise in (Bayesian) infants. Specifically, we show that these distinct forms of attachment emerge from a minimisation of free energy—over interoceptive states relating to internal stress levels—when seeking proximity to caregivers who have a varying impact on these interoceptive states. In line with empirical findings in disrupted patterns of affective communication, we then demonstrate how exteroceptive cues (in the form of caregiver-mediated AMBIANCE affective communication errors, ACE) can result in disorganised forms of attachment in infants of caregivers who consistently increase stress when the infant seeks proximity, but can have an organising (towards ambivalence) effect in infants of inconsistent caregivers. In particular, we differentiate disorganised attachment from avoidance in terms of the high epistemic value of proximity seeking behaviours (resulting from the caregiver’s misleading exteroceptive cues) that preclude the emergence of coherent and organised behavioural policies. Our work, the first to formulate infant attachment in terms of active inference, makes a new testable prediction with regards to the types of affective communication errors that engender ambivalent attachment. PMID:29621266

Characterization of Nonjunctional Hemichannels in Caterpillar Cells

PubMed Central

Luo, Kaijun; Turnbull, Matthew W.

2011-01-01

Recent studies have demonstrated that hemichannels, which form gap junctions when paired from apposing cells, may serve additional roles when unpaired including cell adhesion and paracrine communication. Hemichannels in mammals are formed by connexins or pannexins, while in insects they are formed by pannexin homologues termed innexins. The formation of functional gap junctions by insect innexins has been established, although their ability to form functional nonjunctional hemichannels has not been reported. Here the characteristics of nonjunctional hemichannels were examined in three lepidopteran cell types, two cell lines (High Five and Sf9) and explanted hemocytes from Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae). Selective fluorescent dye uptake by hemichannels was observed in a significant minority of cells, using fluorescence microscopy and flow cytometry. Carbenoxelone, an inhibitor of mammalian junctions, disrupted dye uptake, while flufenamic acid and mefloquine did not. The presence of Ca2+ and Mg2+ in the media increased hemichannel activity. Additionally, lipopolysaccharide, a stimulator of immune activity in lepidopterans, decreased dye uptake. These results demonstrate for the first time the activity of nonjunctional hemichannels in insect cells, as well as pharmacological tools to manipulate them. These results will facilitate the further examination of the role of innexins and nonjunctional hemichannels in insect cell biology, including paracrine signaling, and comparative studies of mammalian pannexins and insect innexins. PMID:21521140

Role of asparagine 152 in catalysis of beta-lactam hydrolysis by Escherichia coli AmpC beta-lactamase studied by site-directed mutagenesis.

PubMed

Dubus, A; Normark, S; Kania, M; Page, M G

1995-06-13

The role of asparagine 152 in the catalytic mechanism of Escherichia coli AmpC beta-lactamase has been investigated by site-directed mutagenesis. The residue has been replaced by aspartic acid, glutamic acid, histidine, and leucine. All the substitutions had similar effects on the activity toward substrates and inhibitors. The rate of substrate hydrolysis decreased by factors of 500-5000. The rates of both acylation (2-50-fold decrease) and deacylation (50-500-fold decrease) were affected, indicating a role for Asn152 in both processes. The wild-type AmpC beta-lactamase appears to exist as an equilibrium mixture of two forms, identified by their different kinetic properties. The Asn152 mutations affected the activity of the slow-reacting form much more than that of the fast-reacting form, but they did not appear to affect the interconversion of these two kinetic forms. Comparison of these observations with results obtained with mutation of the equivalent residues in other classes of penicillin-sensitive enzyme indicates that there are quite profound differences between the catalytic mechanisms of these enzymes despite a high degree of conservation of amino acids in the active center, and of the overall three-dimensional structure.

Determination of dasatinib in the tablet dosage form by ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis.

PubMed

Gonzalez, Aroa Garcia; Taraba, Lukáš; Hraníček, Jakub; Kozlík, Petr; Coufal, Pavel

2017-01-01

Dasatinib is a novel oral prescription drug proposed for treating adult patients with chronic myeloid leukemia. Three analytical methods, namely ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis, were developed, validated, and compared for determination of the drug in the tablet dosage form. The total analysis time of optimized ultra high performance liquid chromatography and capillary zone electrophoresis methods was 2.0 and 2.2 min, respectively. Direct ultraviolet detection with detection wavelength of 322 nm was employed in both cases. The optimized sequential injection analysis method was based on spectrophotometric detection of dasatinib after a simple colorimetric reaction with folin ciocalteau reagent forming a blue-colored complex with an absorbance maximum at 745 nm. The total analysis time was 2.5 min. The ultra high performance liquid chromatography method provided the lowest detection and quantitation limits and the most precise and accurate results. All three newly developed methods were demonstrated to be specific, linear, sensitive, precise, and accurate, providing results satisfactorily meeting the requirements of the pharmaceutical industry, and can be employed for the routine determination of the active pharmaceutical ingredient in the tablet dosage form. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Therapeutic applications of radioactive (131)iodine: Procedures and incidents with capsules.

PubMed

Al Aamri, Marwa; Ravichandran, Ramamoorthy; Binukumar, John Pichy; Al Balushi, Naima

2016-01-01

Treatments for thyrotoxicosis and carcinoma thyroid are carried out by oral administration of radioactive iodine ((131)I) in the form of liquid or capsules. The liquid form of (131)I has higher risk factors such as vapourization, spillage and need for management of higher activity wastes. Use of (131)I in capsule form simplify procedures of handling compared to liquid form of (131)I. The guidelines of safe handling and quality assurance aspects for therapeutic use (131)I are well outlined by International Atomic Energy Agency (IAEA) reports. A few unusual incidents with I-131 capsules encountered in the past need to be highlighted from health physics point of view. In Royal Hospital, Oman, I-131 is imported in capsules, and the total activity handled/year steadily increased over 10 years. Discrete activities range from 185 MBq (5 mCi) up to 7.4 GBq (200 mCi). In four incidents deviations in standard operational procedures were recorded. Nature of incidents is described as follows: (1) After assay of activity, the capsule was directly put in the lead container with missing of inner cap. (2) Patient poured water in the Perspex tube, when the capsule was handed over to her, making an emergency situation. (3) In 3 high activity capsules (2 nos 2.96 GBq, 1 no. 4.26 GBq), observed sticky behavior in capsule holder on the 2(nd) day post receipt, which were in order on the 1(st) day. (4) A capsule could not be swallowed by a patient, which was taken back from the mouth. Monitoring of patient later did not show residual ingested activity. The report documents some of the unusual incidents for information to other centers engaged in such radioactive administrations.

A New Method for Delivering a Hydrophobic Drug for Photodynamic Therapy Using Pure Nanocrystal Form of the Drug

PubMed Central

Baba, Koichi; Pudavar, Haridas E.; Roy, Indrajit; Ohulchanskyy, Tymish Y.; Chen, Yihui; Pandey, Ravindra; Prasad, Paras N.

2008-01-01

A carrier free method for delivery of a hydrophobic drug in its pure form, using nanocrystals (nano sized crystals) is proposed. To demonstrate this technique, nanocrystals of a hydrophobic photosensitizing anticancer drug 2-devinyl-2-(1-hexyloxyethyl)pyropheophorbide (HPPH), have been synthesized using re-precipitation method. The resulting drug nanocrystals were monodispersed and stable in aqueous dispersion, without the necessity of an additional stabilizer (surfactant). As shown by confocal microscopy, these pure drug nanocrystals were taken-up by the cancer cells with high avidity. Though the fluorescence and photodynamic activity of the drug were substantially quenched in the form of nanocrystals in aqueous suspension, both these characteristics were recovered under in vitro and in vivo conditions. This recovery of drug activity and fluorescence is possibly due to the interaction of nanocrystals with serum albumin, resulting in conversion of the drug nanocrystals into the molecular form. This was confirmed by demonstrating similar recovery in presence of Fetal Bovine Serum (FBS) or Bovine Serum Albumin (BSA). Under similar treatment conditions, the HPPH in nanocrystal form or in 1% Tween 80/water formulation showed comparable in vitro and in vivo efficacy. PMID:17266331

High-spectral resolution solar microwave observations

NASA Technical Reports Server (NTRS)

Hurford, G. J.

1986-01-01

The application of high-spectral resolution microwave observations to the study of solar activity is discussed with particular emphasis on the frequency dependence of microwave emission from solar active regions. A shell model of gyroresonance emission from active regions is described which suggest that high-spectral resolution, spatially-resolved observations can provide quantitative information about the magnetic field distribution at the base of the corona. Corresponding observations of a single sunspot with the Owens Valley frequency-agile interferometer at 56 frequencies between 1.2 and 14 Ghs are presented. The overall form of the observed size and brightness temperature spectra was consistent with expectations based on the shell model, although there were differences of potential physical significance. The merits and weaknesses of microwave spectroscopy as a technique for measuring magnetic fields in the solar corona are briefly discussed.

Recommended oral sodium bicarbonate administration for urine alkalinization did not affect the concentration of mitomycin-C in non-muscle invasive bladder cancer patients.

PubMed

Seo, Ho Kyung; Kim, Sung Han; Ahn, Kyung-Ohk; Lee, Sang-Jin; Park, Weon Seo; Kim, Sohee; Hwang, Sang-Hyun; Lee, Do Hoon; Joung, Jae Young; Chung, Jinsoo; Joo, Jungnam; Jeong, Kyung-Chae

2017-11-10

Sodium bicarbonate has been reported to maximize the efficacy of intravesical instillation of mitomycin-C (IVI-MMC) therapy by urine alkalinization in non-muscle-invasive bladder cancer (NMIBC). This study aimed to analyze the changes in MMC concentration according to urinary pH and evaluate the efficacy of sodium bicarbonate to maintain the concentration of active form of MMC during IVI-MMC. We prospectively enrolled 26 patients with NMIBC after transurethral resection of bladder tumor. Patients with very high-risk and low-risk NMIBC were excluded. Urinary creatinine, volume, pH, and concentrations of MMC and its degraded form were measured immediately before and after IVI-MMC. The patients were administered 1.5 g of oral sodium bicarbonate during the preceding evening, in the morning, and immediately before the fourth cycle of the six-cycle IVI-MMC. The correlation between MMC concentration and urinary pH changes was explored with or without oral bicarbonate therapy. Recurrence without progression to muscle-invasive disease was noted in 4 of 26 patients in a 23.7-month follow-up. The mean urinary pH before and after the therapy increased from 6.03 to 6.50, and 6.46 to 7.24, without or with oral SB therapy, respectively. Despite this increase, the concentration of active form of MMC did not change significantly. No correlation was found between urinary pH and MMC concentration. Urine alkalinization by SB administration did not maintain the high concentration of urinary MMC. Urine alkalinization by sodium bicarbonate administration for IVI-MMC did not maintain the high concentration of active urinary MMC in NMIBC.

In Vivo Effects of Free Form Astaxanthin Powder on Anti-Oxidation and Lipid Metabolism with High-Cholesterol Diet

PubMed Central

Chen, Yung-Yi; Lee, Pei-Chi; Wu, Yi-Long; Liu, Li-Yun

2015-01-01

Astaxanthin extracted from Pomacea canaliculata eggs was made into free-form astaxanthin powder (FFAP) and its effects on lipid metabolism, liver function, antioxidants activities and astaxanthin absorption rate were investigated. 45 hamsters were split into 5 groups and fed with normal diet, high-cholesterol control (0.2% cholesterol), 1.6FFAP (control+1.6% FFAP), 3.2FFAP (control+3.2% FFAP) and 8.0FFAP (control+8.0% FFAP), respectively, for 6 weeks. FFAP diets significantly decreased the liver total cholesterol, triglyceride levels and increased liver fatty acids (C20:5n3; C22:6n3) compositions. It decreased plasma alanine aminotransferase and aspartate aminotransferase. In terms of anti-oxidative activities, we found 8.0 FFAP diet significantly decreased plasma and liver malonaldehyde (4.96±1.96 μg TEP eq./mL and 1.56±0.38 μg TEP eq./g liver) and liver 8-isoprostane levels (41.48±13.69 μg 8-ISOP/g liver). On the other hand, it significantly increased liver catalase activity (149.10±10.76 μmol/min/g liver), Vitamin C (2082.97±142.23 μg/g liver), Vitamin E (411.32±81.67 μg/g liver) contents, and glutathione levels (2.13±0.42 mg GSH eq./g liver). Furthermore, 80% of astaxanthin absorption rates in all FFAP diet groups suggest FFAP is an effective form in astaxanthin absorption. Finally, astaxanthin was found to re-distribute to the liver and eyes in a dose dependent manner. Taken together, our results suggested that the appropriate addition of FFAP into high cholesterol diets increases liver anti-oxidative activity and reduces the concentration of lipid peroxidase and therefore, it may be beneficial as a material in developing healthy food. PMID:26262684

1,2,3-Triazolyl ester of Ketorolac: A "Click Chemistry"-based highly potent PAK1-blocking cancer-killer.

PubMed

Nguyen, Binh Cao Quan; Takahashi, Hideaki; Uto, Yoshihiro; Shahinozzaman, M D; Tawata, Shinkichi; Maruta, Hiroshi

2017-01-27

An old anti-inflammatory/analgesic drug called Toradol is a racemic form of Ketorolac (50% R-form and 50% S-form) that blocks the oncogenic RAC-PAK1-COX-2 (cyclooxygenase-2) signaling, through the direct inhibition of RAC by the R-form and of COX-2 by the S-form, eventually down-regulating the production of prostaglandins. However, due to its COOH moiety which is clearly repulsive to negatively-charged phospholipid-based plasma membrane, its cell-permeability is rather poor (the IC 50 against the growth of human cancer cells such as A549 is around 13 μM). In an attempt to boost its anti-cancer activity, hopefully by increasing its cell-permeability through abolishing the negative charge, yet keeping its water-solubility, here we synthesized a 1,2,3-triazolyl ester of Toradol through "Click Chemistry". The resultant water-soluble "azo" derivative called "15K" was found to be over 500 times more potent than Toradol with the IC 50 around 24 nM against the PAK1-dependent growth of A549 cancer cells, inactivating PAK1 in cell culture with the apparent IC 50 around 65 nM, and inhibiting COX-2 in vitro with the IC 50 around 6 nM. Furthermore, the Click Chemistry boosts the anti-cancer activity of Ketorolac by 5000 times against the PAK1-independent growth of B16F10 melanoma cells. Using a multi-drug-resistant (MDR) cancer cell line (EMT6), we found that the esterization of Ketorolac boosts its cell-permeability by at least 10 folds. Thus, the Click Chemistry dramatically boosts the anti-cancer activity of Ketorolac, at least in three ways: increasing its cell-permeability, the anti-PAK1 activity of R-form and anti-COX-2 activity of S-form. The resultant "15K" is so far among the most potent PAK1-blockers, and therefore would be potentially useful for the therapy of many different PAK1-dependent diseases/disorders such as cancers. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

R-Ras Contributes to LTP and Contextual Discrimination

PubMed Central

Darcy, Michael J.; Jin, Shan-Xue; Feig, Larry A.

2014-01-01

The ability to discriminate between closely related contexts is a specific form of hippocampal-dependent learning that may be impaired in certain neurodegenerative disorders such as Alzheimer's and Down Syndrome. However, signaling pathways regulating this form of learning are poorly understood. Previous studies have shown that the calcium-dependent exchange factor Ras-GRF1, an activator of Rac, Ras and R-Ras GTPases, is important for this form of learning and memory. Moreover, the ability to discriminate contexts was linked to the ability of Ras-GRF1 to promote high-frequency stimulation (HFS)-LTP via the activation of p38 Map kinase. Here, we show that R-Ras is involved in this form of learning by using virally-delivered miRNAs targeting R-Ras into the CA1 region of dorsal hippocampus and observing impaired contextual discrimination. Like the loss of GRF1, knockdown of R-Ras in the CA1 also impairs the induction of HFS-LTP and p38 Map kinase. Nevertheless, experiments indicate that this involvement of R-Ras in HFS-LTP that is required for contextual discrimination is independent of Ras-GRF1. Thus, R-Ras is a novel regulator of a form of hippocampal-dependent LTP as well as learning and memory that is affected in certain forms of neurodegenerative diseases. PMID:25043327

Enzymes in Glycolysis and the Citric Acid Cycle in the Yeast and Mycelial Forms of Paracoccidioides brasiliensis

PubMed Central

Kanetsuna, Fuminori; Carbonell, Luis M.

1966-01-01

Kanetsuna, Fuminori (Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela), and Luis M. Carbonell. Enzymes in glycolysis and the citric acid cycle in the yeast and mycelial forms of Paracoccidioides brasiliensis. J. Bacteriol. 92:1315–1320. 1966.—Enzymatic activities in glycolysis, the hexose monophosphate shunt, and the citric acid cycle in cell-free extracts of the yeast and mycelial forms of Paracoccidioides brasiliensis were examined comparatively. Both forms have the enzymes of these pathways. Activities of glucose-6-phosphate dehydrogenase and malic dehydrogenase of the mycelial form were higher than those of the yeast form. Another 15 enzymatic activities of the mycelial form were lower than those of the yeast form. The activity of glyceraldehyde-3-phosphate dehydrogenase showed the most marked difference between the two forms, its activity in the mycelial form being about 20% of that in the yeast form. PMID:5924267

Exotic stable cesium polynitrides at high pressure

DOE PAGES

Peng, Feng; Han, Yunxia; Liu, Hanyu; ...

2015-11-19

New polynitrides containing metastable forms of nitrogen are actively investigated as potential high energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN 3, we identified five new stoichiometric compounds (Cs 3N, Cs 2N, CsN, CsN 2, and CsN 5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N 2, N 3 , Nmore » 4, N 5, N 6) and chains (N ∞). Polymeric chains of nitrogen were found in the high-pressure C2/c phase of CsN 2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N 4 4- anion. In conclusion, to our best knowledge, this is the first time a charged N 4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure.« less

Exotic stable cesium polynitrides at high pressure

PubMed Central

Peng, Feng; Han, Yunxia; Liu, Hanyu; Yao, Yansun

2015-01-01

New polynitrides containing metastable forms of nitrogen are actively investigated as potential high-energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN3, we identified five new stoichiometric compounds (Cs3N, Cs2N, CsN, CsN2, and CsN5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N2, N3, N4, N5, N6) and chains (N∞). Polymeric chains of nitrogen were found in the high-pressure C2/c phase of CsN2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N44− anion. To our best knowledge, this is the first time a charged N4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure. PMID:26581175

Radon as a natural tracer for underwater cave exploration.

PubMed

Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

2017-07-01

The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL -1 ) in the springwater. According to previous studies, the origin of radon was identified as iron-hydroxide containing biofilms, which form where there is mixing of cold and thermal waters, and these biofilms efficiently adsorb radium from the thermal water component. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and the consequent high radon concentrations mark the active cave forming zones. Based on previous radon measurements, it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore radon mapping was carried out with the help of divers in order to get a spatial distribution of radon in the cave passages closest to the spring. Based on our measurements, the highest radon activity concentration (84 BqL -1 ) was found in the springwater. Based on the distribution of radon activity concentrations, direct connection was established between the spring and the István-room of the cave, which was verified by an artificial tracer. However, the distribution of radon in the cave passages shows lower concentrations (18-46 BqL -1 ) compared to the spring, therefore an additional deep inflow from hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are assumed to be in the active cave formation zone. This study proved that radon activity concentration distribution is a useful tool in underwater cave exploration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Erythroblast Transformation by the Friend Spleen Focus-Forming Virus Is Associated with a Block in Erythropoietin-Induced STAT1 Phosphorylation and DNA Binding and Correlates with High Expression of the Hematopoietic Phosphatase SHP-1

PubMed Central

Nishigaki, Kazuo; Hanson, Charlotte; Ohashi, Takashi; Spadaccini, Angelo; Ruscetti, Sandra

2006-01-01

Infection of mice with Friend spleen focus-forming virus (SFFV) results in a multistage erythroleukemia. In the first stage, the SFFV envelope glycoprotein interacts with the erythropoietin receptor and a short form of the receptor tyrosine kinase sf-Stk, resulting in constitutive activation of signal transducing molecules and the development of erythropoietin (Epo)-independent erythroid hyperplasia and polycythemia. The second stage results from the outgrowth of a rare virus-infected erythroid cell that expresses nonphysiological levels of the myeloid transcription factor PU.1. These cells exhibit a differentiation block and can be grown as murine erythroleukemia (MEL) cell lines. In this study, we examined SFFV MEL cells to determine whether their transformed phenotype was associated with a block in the activation of any Epo signal-transducing molecules. Our studies indicate that Epo- or SFFV-induced activation of STAT1/3 DNA binding activity is blocked in SFFV MEL cells. The block is at the level of tyrosine phosphorylation of STAT1, although Jak2 phosphorylation is not blocked in these cells. In contrast to Epo, alpha interferon can induce STAT1 phosphorylation and DNA binding in SFFV MEL cells. The SFFV-transformed cells were shown to express elevated levels of the hematopoietic phosphatase SHP-1, and treatment of the cells with a phosphatase inhibitor restored STAT1 tyrosine phosphorylation. MEL cells derived from Friend murine leukemia virus (MuLV) or ME26 MuLV-infected mice, which do not express PU.1, express lower levels of SHP-1 and are not blocked in STAT1/3 DNA-binding activity. Our studies suggest that SFFV-infected erythroid cells become transformed when differentiation signals activated by STAT1/3 are blocked due to high SHP-1 levels induced by inappropriate expression of the PU.1 protein. PMID:16731906

Tetracycline removal from water by adsorption/bioadsorption on activated carbons and sludge-derived adsorbents.

PubMed

Rivera-Utrilla, José; Gómez-Pacheco, Carla V; Sánchez-Polo, Manuel; López-Peñalver, Jesús J; Ocampo-Pérez, Raúl

2013-12-15

The objective of this study was to analyze the behavior of activated carbons with different chemical and textural natures in the adsorption of three tetracyclines (TCs) (tetracycline, oxytetracycline, and chlortetracycline). We also assessed the influence of the solution pH and ionic strength on the adsorption of these compounds and studied their removal by the combined use of microorganisms and activated carbon (bioadsorption). Sludge-derived materials were also used to remove TC from water. The capacity of these materials to adsorb TC was very high and was much greater than that of commercial activated carbon. This elevated adsorption capacity (512.1-672.0 mg/g) is explained by the high tendency of TC to form complex ions with some of the metal ions present in these materials. The medium pH and presence of electrolytes considerably affected TCs adsorption on commercial activated carbon. These results indicate that electrostatic adsorbent-adsorbate interactions play an important role in TC adsorption processes when conducted at pH values that produce TC deprotonation. The presence of bacteria during the TCs adsorption process decreases their adsorption/bioadsorption on the commercial activated carbon, weakening interactions between the adsorbate and the microfilm formed on the carbon surface. The adsorptive capacity was considerably lower in dynamic versus static regime, attributable to problems of TC diffusion into carbon pores and the shorter contact time between adsorbate and adsorbent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phosphorylation-induced changes in the energetic frustration in human Tank binding kinase 1.

PubMed

Husain, Shahrukh; Kumar, Vijay; Hassan, Md Imtaiyaz

2018-07-14

Tank binding kinase 1 (TBK-1) plays an important role in immunity, inflammation, autophagy, cell growth and proliferation. Nevertheless, a key molecular and structural detail of TBK-1 phosphorylation and activation has been largely unknown. Here we investigated the energy landscape of phosphorylated (active) and unphosphorylated (inactive) forms of human TBK-1 to characterize the interplay between phosphorylation and local frustration. By employing the algorithm equipped with energy function and implemented in Frustratometer web-server (http://www.frustratometer.tk), we quantify the role of frustration in the activation of TBK-1. Accordingly, the conformational changes were observed in phosphoregulated active and inactive TBK-1. Substantial changes in frustration, flexibility and interatomic motions were observed among different forms of TBK-1. Structurally rigid kinase domain constitutes a minimally frustrated hub in the core of the catalytic domain, and highly frustrated clusters mainly at the C-lobe might enable the conformational transitions during activation. Also, a large network of highly frustrated interactions is found in the SDD domain of TBK-1 involved in protein-protein interactions and dimerization. The contact maps of the activation loop and α-C helix of kinase domain showed significant changes upon phosphorylation. Cross correlation analysis indicate that both intra and inter subunit correlated motions increases with phosphorylation of TBK-1. Phosphorylation thus introduces subtle changes in long-range contacts that might lead to significant conformational change of TBK-1. Copyright © 2018 Elsevier Ltd. All rights reserved.

The U.S. Constitution. A Teacher's Guide. Six 30-Minute Video Programs for Junior High and High School Students.

ERIC Educational Resources Information Center

Patrick, John J.

This teacher's guide was designed to accompany six 30-minute video programs on the fundamental constitutional principles that form this nation's foundation. Each lesson in the guide contains an introduction to the main ideas of the program, a program summary, and suggested activities to carry out before and after the program. The topics emphasized…

Nonequiatomic NiTi Alloy Produced by Self Propagating High Temperature Synthesis

NASA Astrophysics Data System (ADS)

Bassani, P.; Bassani, E.; Tuissi, A.; Giuliani, P.; Zanotti, C.

2014-07-01

Shape memory alloy NiTi in porous form is of high interest as implantable material, as low apparent elastic modulus, comparable to that of bone, can be achieved. This condition, combined with proper pore size, allows good osteointegration. Porous NiTi can be produced by self propagating high temperature synthesis (SHS), starting from mixed powders of pure Ni and Ti. Process parameters, among which powder compaction degree and preheating temperature, strongly influence the reaction temperature and the resulting product: at low reaction temperatures, high quantity of secondary phases are formed, which are generally considered detrimental for biocompatibility. On the contrary, at higher reaction temperatures, the powders melt and crystallize in ingots. The porous structure is lost and huge pores are formed. Mechanical activation of powders through ball milling and addition of TiH x are investigated as means to reduce reaction temperature and overheating, in order to preserve high porosity and limit secondary phases content. Both processes affect SHS reaction, and require adjustment of parameters such as heating rate. Changes in porous shape and size were observed especially for TiH x additions: the latter could be a promising route to obtain shaped porous products of improved quality.

The Activity of Trace Metals in Aqueous Systems and the Effect of Corrosion Control Inhibitors

DTIC Science & Technology

1975-10-01

corrosion product on metallic zinc 49 Uncombined slilica as quartz or cristobalite forms by the hydrothermal alteration of solid zilicates or by direct... hydrothermally . The com- position of the solids are dependent on temperature and pressure as well as on the relative concentrations of the dissolved...of the few anhydrous simple silicates formed hydrotherm - ally. The sodium silicates, Na2SiO 3 and BNa 2Si205, are somewhat soluble in high temperature

[Pectolytic enzymes formed by Penicillium and Fusarium micromycetes].

PubMed

Devdariani, T G; Aĭzenberg, V L; Bilaĭ, T I; Zakordonets, L A; Mudzhiri, L A

1982-01-01

The ability of the two cultures Penicillium sp. and Fusarium sp. to synthesize extracellular pectolytic enzymes was investigated. The cultivation conditions providing a high level of the biosynthesis of these enzymes were identified. The methods of isolating the enzymes by means of organic solvents were developed. The pectinase from Penicillium sp. showed a higher thermostability whereas that from Fusarium sp. displayed a greater acid resistance. Using glutaraldehyde and titanium salts, active immobilized forms of pectinases on silica carriers were prepared.

Metronidazole as a protector of cells from electromagnetic radiation of extremely high frequencies

NASA Astrophysics Data System (ADS)

Kuznetsov, Pavel E.; Malinina, Ulia A.; Popyhova, Era B.; Rogacheva, Svetlana M.; Somov, Alexander U.

2006-08-01

It is well known that weak electromagnetic fields of extremely high frequencies cause significant modification of the functional status of biological objects of different levels of organization. The aim of the work was to study the combinatory effect of metronidazole - the drug form of 1-(2'hydroxiethil)-2-methil-5-nitroimidazole - and electromagnetic radiation of extremely high frequencies (52...75 GHz) on the hemolytic stability of erythrocytes and hemotaxis activity of Infusoria Paramecium caudatum.

Process for forming a metal compound coating on a substrate

DOEpatents

Sharp, D.J.; Vernon, M.E.; Wright, S.A.

1988-06-29

A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

Primary hyperoxaluria: genotype-phenotype correlation.

PubMed

Pirulli, Doroti; Marangella, Martino; Amoroso, Antonio

2003-01-01

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive disorder caused by a deficiency of alanine-glyoxylate aminotransferase (AGT), which is encoded by a single copy gene (AGXT). Molecular diagnosis was used in conjunction with clinical, biochemical and enzymological data to evaluate genotype-phenotype correlation. Patients can present a severe form of PH1, an adult form and a mild to moderate decrease in renal function. Biochemical diagnosis is made by plasma, urine and dialyzate oxalate and glycolate assays, and by liver AGT activity and pyridoxine responsitivity. Molecular genetic diagnosis can be made using different techniques, for example, the single strand conformation polymorphism technique (SSCP), followed by the sequencing of the 11 AGXT exons. The disease is clinically and genetically classified as highly heterogeneous. Mutant alleles can be recognised in 80- 90% of chromosomes, depending on the techniques used. Mutations in exons 1, 2, 4 and 10 are more frequent in Italian patients. Normalized AGT activity seems to be lower in the severe form than in the adult form. Double heterozygous patients present a lower age at disease onset and they were more frequent in the more severe than in mild severe disease. The 444T>C mutation was more frequent in the severe form, while the opposite was observed for 630G>A. 630G>A mutation homozygotes had a higher AGT residual activity. The presence of allelic heterogeneity of the AGXT could be responsible, to some extent, for the phenotypic heterogeneity in PH1. Homozygous genotypes were more frequent than expected and were associated with a less severe form of the disease.

Atomic resolution crystal structure of VcLMWPTP-1 from Vibrio cholerae O395: Insights into a novel mode of dimerization in the low molecular weight protein tyrosine phosphatase family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nath, Seema; Banerjee, Ramanuj; Sen, Udayaditya, E-mail: udayaditya.sen@saha.ac.in

Highlights: • VcLMWPTP-1 forms dimer in solution. • The dimer is catalytically active unlike other reported dimeric LMWPTPs. • The formation of extended dimeric surface excludes the active site pocket. • The surface bears closer resemblance to eukaryotic LMWPTPs. - Abstract: Low molecular weight protein tyrosine phosphatase (LMWPTP) is a group of phosphotyrosine phosphatase ubiquitously found in a wide range of organisms ranging from bacteria to mammals. Dimerization in the LMWPTP family has been reported earlier which follows a common mechanism involving active site residues leading to an enzymatically inactive species. Here we report a novel form of dimerization inmore » a LMWPTP from Vibrio cholera 0395 (VcLMWPTP-1). Studies in solution reveal the existence of the dimer in solution while kinetic study depicts the active form of the enzyme. This indicates that the mode of dimerization in VcLMWPTP-1 is different from others where active site residues are not involved in the process. A high resolution (1.45 Å) crystal structure of VcLMWPTP-1 confirms a different mode of dimerization where the active site is catalytically accessible as evident by a tightly bound substrate mimicking ligand, MOPS at the active site pocket. Although being a member of a prokaryotic protein family, VcLMWPTP-1 structure resembles very closely to LMWPTP from a eukaryote, Entamoeba histolytica. It also delineates the diverse surface properties around the active site of the enzyme.« less

Magnetic filtration process, magnetic filtering material, and methods of forming magnetic filtering material

DOEpatents

Taboada-Serrano, Patricia; Tsouris, Constantino; Contescu, Cristian I; McFarlane, Joanna

2013-10-08

The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically responsive activated carbon typically includes providing activated carbon in a solution containing ions of ferrite forming elements, wherein at least one of the ferrite forming elements has an oxidation state of +3 and at least a second of the ferrite forming elements has an oxidation state of +2, and increasing pH of the solution to precipitate particles of ferrite that bond to the activated carbon, wherein the activated carbon having the ferrite particles bonded thereto have a positive magnetic susceptibility. The present invention also provides a method of filtering waste water using magnetic activated carbon.

Metabolic potential of lithifying cyanobacteria-dominated thrombolitic mats.

PubMed

Mobberley, Jennifer M; Khodadad, Christina L M; Foster, Jamie S

2013-11-01

Thrombolites are unlaminated carbonate deposits formed by the metabolic activities of microbial mats and can serve as potential models for understanding the molecular mechanisms underlying the formation of lithifying communities. To assess the metabolic complexity of these ecosystems, high throughput DNA sequencing of a thrombolitic mat metagenome was coupled with phenotypic microarray analysis. Functional protein analysis of the thrombolite community metagenome delineated several of the major metabolic pathways that influence carbonate mineralization including cyanobacterial photosynthesis, sulfate reduction, sulfide oxidation, and aerobic heterotrophy. Spatial profiling of metabolite utilization within the thrombolite-forming microbial mats suggested that the top 5 mm contained a more metabolically diverse and active community than the deeper within the mat. This study provides evidence that despite the lack of mineral layering within the clotted thrombolite structure there is a vertical gradient of metabolic activity within the thrombolitic mat community. This metagenomic profiling also serves as a foundation for examining the active role individual functional groups of microbes play in coordinating metabolisms that lead to mineralization.

Development of nanoscale structure in LAT-based signaling complexes

PubMed Central

2016-01-01

ABSTRACT The adapter molecule linker for activation of T cells (LAT) plays a crucial role in forming signaling complexes induced by stimulation of the T cell receptor (TCR). These multi-molecular complexes are dynamic structures that activate highly regulated signaling pathways. Previously, we have demonstrated nanoscale structure in LAT-based complexes where the adapter SLP-76 (also known as LCP2) localizes to the periphery of LAT clusters. In this study, we show that initially LAT and SLP-76 are randomly dispersed throughout the clusters that form upon TCR engagement. The segregation of LAT and SLP-76 develops near the end of the spreading process. The local concentration of LAT also increases at the same time. Both changes require TCR activation and an intact actin cytoskeleton. These results demonstrate that the nanoscale organization of LAT-based signaling complexes is dynamic and indicates that different kinds of LAT-based complexes appear at different times during T cell activation. PMID:27875277

Glutamate decarboxylase from Lactobacillus brevis: activation by ammonium sulfate.

PubMed

Hiraga, Kazumi; Ueno, Yoshie; Oda, Kohei

2008-05-01

In this study, the glutamate decarboxylase (GAD) gene from Lactobacillus brevis IFO12005 (Biosci. Biotechnol. Biochem., 61, 1168-1171 (1997)), was cloned and expressed. The deduced amino acid sequence showed 99.6% and 53.1% identity with GAD of L. brevis ATCC367 and L. lactis respectively. The His-tagged recombinant GAD showed an optimum pH of 4.5-5.0, and 54 kDa on SDS-PAGE. The GAD activity and stability was significantly dependent on the ammonium sulfate concentration, as observed in authentic GAD. Gel filtration showed that the inactive form of the GAD was a dimer. In contrast, the ammonium sulfate-activated form was a tetramer. CD spectral analyses at pH 5.5 revealed that the structures of the tetramer and the dimer were similar. Treatment of the GAD with high concentrations of ammonium sulfate and subsequent dilution with sodium glutamate was essential for tetramer formation and its activation. Thus the biochemical properties of the GAD from L. brevis IFO12005 were significantly different from those from other sources.

Life on Titan

NASA Astrophysics Data System (ADS)

Potashko, Oleksandr

Volcanoes engender life on heavenly bodies; they are pacemakers of life. All planets during their period of formation pass through volcanism hence - all planets and their satellites pass through the life. Tracks of life If we want to find tracks of life - most promising places are places with volcanic activity, current or past. In the case of just-in-time volcanic activity we have 100% probability to find a life. Therefore the most perspective “search for life” are Enceladus, Io and comets, further would be Venus, Jupiter’s satellites, Saturn’s satellites and first of all - Titan. Titan has atmosphere. It might be result of high volcanic activity - from one side, from other side atmosphere is a necessary condition development life from procaryota to eucaryota. Existence of a planet means that all its elements after hydrogen formed just there inside a planet. The forming of the elements leads to the formation of mineral and organic substances and further to the organic life. Development of the life depends upon many factors, e.g. the distance from star/s. The intensity of the processes of the element formation is inversely to the distance from the star. Therefore we may suppose that the intensity of the life in Mercury was very high. Hence we may detect tracks of life in Mercury, particularly near volcanoes. The distance from the star is only one parameter and now Titan looks very active - mainly due to interior reason. Its atmosphere compounds are analogous to comet tail compounds. Their collation may lead to interesting result as progress occurs at one of them. Volcanic activity is as a source of life origin as well a reason for a death of life. It depends upon the thickness of planet crust. In the case of small thickness of a crust the probability is high that volcanoes may destroy a life on a planet - like Noachian deluge. Destroying of the life under volcano influences doesn’t lead to full dead. As result we would have periodic Noachian deluge or nuclear winter. These events are known as extinctions or ice ages. The crust of a planet of the Earth group is formed at the outer edge of the body. The planets after asteroid belt like Jupiter or Saturn probably form their “crusts” in the centre of the body. Due to we may see internal kitchen of element forming in detail. This processes lead to the organic life, which we may detect at the atmospheres of Jupiter, Saturn, Neptune, and Pluto. But their satellites look like earth planet group - with outer crust. Huygens considered that God's wisdom and providence is clearest in the creation of life, and Earth holds no privileged position in the heavens that life must be universal. “Huygens” helps find life on Titan

In-flight simulation of high agility through active control: Taming complexity by design

NASA Technical Reports Server (NTRS)

Padfield, Gareth D.; Bradley, Roy

1993-01-01

The motivation for research into helicopter agility stems from the realization that marked improvements relative to current operational types are possible, yet there is a dearth of useful criteria for flying qualities at high performance levels. Several research laboratories are currently investing resources in developing second generation airborne rotorcraft simulators. The UK's focus has been the exploitation of agility through active control technology (ACT); this paper reviews the results of studies conducted to date. The conflict between safety and performance in flight research is highlighted and the various forms of safety net to protect against system failures are described. The role of the safety pilot, and the use of actuator and flight envelope limiting are discussed. It is argued that the deep complexity of a research ACT system can only be tamed through a requirement specification assembled using design principles and cast in an operational simulation form. Work along these lines conducted at DRA is described, including the use of the Jackson System Development method and associated Ada simulation.

Controlling Plasmon-Enhanced Fluorescence via Intersystem Crossing in Photoswitchable Molecules.

PubMed

Wang, Mingsong; Hartmann, Gregory; Wu, Zilong; Scarabelli, Leonardo; Rajeeva, Bharath Bangalore; Jarrett, Jeremy W; Perillo, Evan P; Dunn, Andrew K; Liz-Marzán, Luis M; Hwang, Gyeong S; Zheng, Yuebing

2017-10-01

By harnessing photoswitchable intersystem crossing (ISC) in spiropyran (SP) molecules, active control of plasmon-enhanced fluorescence in the hybrid systems of SP molecules and plasmonic nanostructures is achieved. Specifically, SP-derived merocyanine (MC) molecules formed by photochemical ring-opening reaction display efficient ISC due to their zwitterionic character. In contrast, ISC in quinoidal MC molecules formed by thermal ring-opening reaction is negligible. The high ISC rate can improve fluorescence quantum yield of the plasmon-modified spontaneous emission, only when the plasmonic electromagnetic field enhancement is sufficiently high. Along this line, extensive photomodulation of fluorescence is demonstrated by switching the ISC in MC molecules at Au nanoparticle aggregates, where strongly enhanced plasmonic hot spots exist. The ISC-mediated plasmon-enhanced fluorescence represents a new approach toward controlling the spontaneous emission of fluorophores near plasmonic nanostructures, which expands the applications of active molecular plasmonics in information processing, biosensing, and bioimaging. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated arrays of air-dielectric graphene transistors as transparent active-matrix pressure sensors for wide pressure ranges.

PubMed

Shin, Sung-Ho; Ji, Sangyoon; Choi, Seiho; Pyo, Kyoung-Hee; Wan An, Byeong; Park, Jihun; Kim, Joohee; Kim, Ju-Young; Lee, Ki-Suk; Kwon, Soon-Yong; Heo, Jaeyeong; Park, Byong-Guk; Park, Jang-Ung

2017-03-31

Integrated electronic circuitries with pressure sensors have been extensively researched as a key component for emerging electronics applications such as electronic skins and health-monitoring devices. Although existing pressure sensors display high sensitivities, they can only be used for specific purposes due to the narrow range of detectable pressure (under tens of kPa) and the difficulty of forming highly integrated arrays. However, it is essential to develop tactile pressure sensors with a wide pressure range in order to use them for diverse application areas including medical diagnosis, robotics or automotive electronics. Here we report an unconventional approach for fabricating fully integrated active-matrix arrays of pressure-sensitive graphene transistors with air-dielectric layers simply formed by folding two opposing panels. Furthermore, this realizes a wide tactile pressure sensing range from 250 Pa to ∼3 MPa. Additionally, fabrication of pressure sensor arrays and transparent pressure sensors are demonstrated, suggesting their substantial promise as next-generation electronics.

Integrated arrays of air-dielectric graphene transistors as transparent active-matrix pressure sensors for wide pressure ranges

NASA Astrophysics Data System (ADS)

Shin, Sung-Ho; Ji, Sangyoon; Choi, Seiho; Pyo, Kyoung-Hee; Wan An, Byeong; Park, Jihun; Kim, Joohee; Kim, Ju-Young; Lee, Ki-Suk; Kwon, Soon-Yong; Heo, Jaeyeong; Park, Byong-Guk; Park, Jang-Ung

2017-03-01

Integrated electronic circuitries with pressure sensors have been extensively researched as a key component for emerging electronics applications such as electronic skins and health-monitoring devices. Although existing pressure sensors display high sensitivities, they can only be used for specific purposes due to the narrow range of detectable pressure (under tens of kPa) and the difficulty of forming highly integrated arrays. However, it is essential to develop tactile pressure sensors with a wide pressure range in order to use them for diverse application areas including medical diagnosis, robotics or automotive electronics. Here we report an unconventional approach for fabricating fully integrated active-matrix arrays of pressure-sensitive graphene transistors with air-dielectric layers simply formed by folding two opposing panels. Furthermore, this realizes a wide tactile pressure sensing range from 250 Pa to ~3 MPa. Additionally, fabrication of pressure sensor arrays and transparent pressure sensors are demonstrated, suggesting their substantial promise as next-generation electronics.

Integrated arrays of air-dielectric graphene transistors as transparent active-matrix pressure sensors for wide pressure ranges

PubMed Central

Shin, Sung-Ho; Ji, Sangyoon; Choi, Seiho; Pyo, Kyoung-Hee; Wan An, Byeong; Park, Jihun; Kim, Joohee; Kim, Ju-Young; Lee, Ki-Suk; Kwon, Soon-Yong; Heo, Jaeyeong; Park, Byong-Guk; Park, Jang-Ung

2017-01-01

Integrated electronic circuitries with pressure sensors have been extensively researched as a key component for emerging electronics applications such as electronic skins and health-monitoring devices. Although existing pressure sensors display high sensitivities, they can only be used for specific purposes due to the narrow range of detectable pressure (under tens of kPa) and the difficulty of forming highly integrated arrays. However, it is essential to develop tactile pressure sensors with a wide pressure range in order to use them for diverse application areas including medical diagnosis, robotics or automotive electronics. Here we report an unconventional approach for fabricating fully integrated active-matrix arrays of pressure-sensitive graphene transistors with air-dielectric layers simply formed by folding two opposing panels. Furthermore, this realizes a wide tactile pressure sensing range from 250 Pa to ∼3 MPa. Additionally, fabrication of pressure sensor arrays and transparent pressure sensors are demonstrated, suggesting their substantial promise as next-generation electronics. PMID:28361867

Structural and characteristic variation of anodic oxide on pure Ti with anodization duration

NASA Astrophysics Data System (ADS)

Mizukoshi, Yoshiteru; Ohtsu, Naofhumi; Masahashi, Naoya

2013-10-01

Change in the structural and characteristic of the anodic oxide on pure Ti with the duration of anodization time was investigated. With the progress of the anodization, the phase of the formed TiO2 successively changed from anatase phase to rutile phase. In the transition process, peak intensities of rutile TiO2 1 0 1, 1 1 1 and 2 1 1 planes of X-ray diffraction characteristically increased. The contact angles of water droplets on the anodize TiO2 were monotonously decreased with the progress of the anodization except on the characteristically oriented rutile surface. In the evaluations of acetaldehyde photocatalysis under UV illumination, the anatase TiO2 anodized for short period exhibited high activities. On the other hand, when illuminated with visible light (>422 nm), rutile-structured TiO2 formed by anodization with a long duration exhibited superior photocatalytic activities probably due to high rutile fraction and sulfur incorporation from the electrolyte.

Chemical Evolution of a Protoplanetary Disk

NASA Astrophysics Data System (ADS)

Semenov, Dmitry A.

2011-12-01

In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition of gas and dust in these systems are presented. Strong variations of temperature, density, high-energy radiation intensities in these disks, both radially and vertically, result in a peculiar disk chemical structure, where a variety of processes are active. In hot, dilute and heavily irradiated atmosphere only the most photostable simple radicals and atoms and atomic ions exist, formed by gas-phase processes. Beneath the atmosphere a partly UV-shielded, warm molecular layer is located, where high-energy radiation drives rich ion-molecule and radical-radical chemistry, both in the gas phase and on dust surfaces. In a cold, dense, dark disk midplane many molecules are frozen out, forming thick icy mantles where surface chemistry is active and where complex polyatomic (organic) species are synthesized. Dynamical processes affect disk chemical composition by enriching it in abundances of complex species produced via slow surface processes, which will become detectable with ALMA.

A single-label phenylpyrrolocytidine provides a molecular beacon-like response reporting HIV-1 RT RNase H activity

PubMed Central

Wahba, Alexander S.; Esmaeili, Abbasali; Damha, Masad J.; Hudson, Robert H. E.

2010-01-01

6-Phenylpyrrolocytidine (PhpC), a structurally conservative and highly fluorescent cytidine analog, was incorporated into oligoribonucleotides. The PhpC-containing RNA formed native-like duplex structures with complementary DNA or RNA. The PhpC-modification was found to act as a sensitive reporter group being non-disruptive to structure and the enzymatic activity of RNase H. A RNA/DNA hybrid possessing a single PhpC insert was an excellent substrate for HIV-1 RT Ribonuclease H and rapidly reported cleavage of the RNA strand with a 14-fold increase in fluorescence intensity. The PhpC-based assay for RNase H was superior to the traditional molecular beacon approach in terms of responsiveness, rapidity and ease (single label versus dual). Furthermore, the PhpC-based assay is amenable to high-throughput microplate assay format and may form the basis for a new screen for inhibitors of HIV-RT RNase H. PMID:19933258

Cryo-EM structure of lysenin pore elucidates membrane insertion by an aerolysin family protein

NASA Astrophysics Data System (ADS)

Bokori-Brown, Monika; Martin, Thomas G.; Naylor, Claire E.; Basak, Ajit K.; Titball, Richard W.; Savva, Christos G.

2016-04-01

Lysenin from the coelomic fluid of the earthworm Eisenia fetida belongs to the aerolysin family of small β-pore-forming toxins (β-PFTs), some members of which are pathogenic to humans and animals. Despite efforts, a high-resolution structure of a channel for this family of proteins has been elusive and therefore the mechanism of activation and membrane insertion remains unclear. Here we determine the pore structure of lysenin by single particle cryo-EM, to 3.1 Å resolution. The nonameric assembly reveals a long β-barrel channel spanning the length of the complex that, unexpectedly, includes the two pre-insertion strands flanking the hypothetical membrane-insertion loop. Examination of other members of the aerolysin family reveals high structural preservation in this region, indicating that the membrane-insertion pathway in this family is conserved. For some toxins, proteolytic activation and pro-peptide removal will facilitate unfolding of the pre-insertion strands, allowing them to form the β-barrel of the channel.

Chaetomium thermophilum formate dehydrogenase has high activity in the reduction of hydrogen carbonate (HCO3 -) to formate.

PubMed

Aslan, Aşkın Sevinç; Valjakka, Jarkko; Ruupunen, Jouni; Yildirim, Deniz; Turner, Nicholas J; Turunen, Ossi; Binay, Barış

2017-01-01

While formate dehydrogenases (FDHs) have been used for cofactor recycling in chemoenzymatic synthesis, the ability of FDH to reduce CO 2 could also be utilized in the conversion of CO 2 to useful products via formate (HCOO - ). In this study, we investigated the reduction of CO 2 in the form of hydrogen carbonate (HCO 3 - ) to formate by FDHs from Candida methylica (CmFDH) and Chaetomium thermophilum (CtFDH) in a NADH-dependent reaction. The catalytic performance with HCO 3 - as a substrate was evaluated by measuring the kinetic rates and conducting productivity assays. CtFDH showed a higher efficiency in converting HCO 3 - to formate than CmFDH, whereas CmFDH was better in the oxidation of formate. The pH optimum of the reduction was at pH 7-8. However, the high concentrations of HCO 3 - reduced the reaction rate. CtFDH was modeled in the presence of HCO 3 - showing that it fits to the active site. The active site setting for hydride transfer in CO 2 reduction was modeled. The hydride donated by NADH would form a favorable contact to the carbon atom of HCO 3 - , resulting in a surplus of electrons within the molecule. This would cause the complex formed by hydrogen carbonate and the hydride to break into formate and hydroxide ions. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Malachite green mediates homodimerization of antibody VL domains to form a fluorescent ternary complex with singular symmetric interfaces

PubMed Central

Szent-Gyorgyi, Chris; Stanfield, Robyn L.; Andreko, Susan; Dempsey, Alison; Ahmed, Mushtaq; Capek, Sara; Waggoner, Alan; Wilson, Ian A.; Bruchez, Marcel P.

2013-01-01

We report that a symmetric small molecule ligand mediates the assembly of antibody light chain variable domains (VLs) into a correspondent symmetric ternary complex with novel interfaces. The L5* Fluorogen Activating Protein (FAP) is a VL domain that binds malachite green dye (MG) to activate intense fluorescence. Crystallography of liganded L5* reveals a 2:1 protein:ligand complex with inclusive C2 symmetry, where MG is almost entirely encapsulated between an antiparallel arrangement of the two VL domains. Unliganded L5* VL domains crystallize as a similar antiparallel VL/VL homodimer. The complementarity determining regions (CDRs) are spatially oriented to form novel VL/VL and VL/ligand interfaces that tightly constrain a propeller conformer of MG. Binding equilibrium analysis suggests highly cooperative assembly to form a very stable VL/MG/VL complex, such that MG behaves as a strong chemical inducer of dimerization. Fusion of two VL domains into a single protein tightens MG binding over 1,000-fold to low picomolar affinity without altering the large binding enthalpy, suggesting that bonding interactions with ligand and restriction of domain movements make independent contributions to binding. Fluorescence activation of a symmetrical fluorogen provides a selection mechanism for the isolation and directed evolution of ternary complexes where unnatural symmetric binding interfaces are favored over canonical antibody interfaces. As exemplified by L5*, these self-reporting complexes may be useful as modulators of protein association or as high affinity protein tags and capture reagents. PMID:23978698

Non-noble catalysts and catalyst supports for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Mcalister, A. J.

1981-01-01

Four different samples of the cubic alloys W sub x-1 Ti sub x C sub 1-y were prepared and found to be active and CO tolerant. When the activities of these cubic alloys were weighted by the reciprocal of the square of the W exchange, they displayed magnitudes and dependence on bulk C deficiency comparable to those of highly active forms of WC. It is concluded that they may offer important insight into the nature of the active sites on, and means for improving the performance of, W-C anode catalysts for use in phosphoric acid fuel cells.

Non-noble catalysts and catalyst supports for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Mcalister, A. J.

1981-01-01

Tungsten carbide, which is active for hydrogen oxidation, is CO tolerant and has a hexagonal structure is discussed. Titanium carbide is inactive and has a cubic structure. Four different samples of the cubic alloys W sub x-1Ti sub XC sub 1-y were found to be active and CO tolerant. When the activities of these cubic alloys are weighted by the reciprocal of the square to those of highly forms of WC. They offer important insight into the nature of the active sites on W-C anode catalysts for use in phosphoric acid fuel cells.

An in vitro examination of the antioxidant and anti-inflammatory properties of buckwheat honey.

PubMed

van den Berg, A J J; van den Worm, E; van Ufford, H C Quarles; Halkes, S B A; Hoekstra, M J; Beukelman, C J

2008-04-01

Hydroxyl radical and hypochlorite anion formed at the wound site from superoxide anion produced by activated polymorphonuclear neutrophils (PMNs) are considered important factors in impaired wound healing. Superoxide anion may also react with nitric oxide produced by macrophages to form peroxynitrite, a third strong oxidant that damages surrounding tissue. In order to select honey for use in wound-healing products, different samples were compared for their capacity to reduce levels of reactive oxygen species (ROS) in vitro. Honey samples were tested in assays for inhibition of ROS production by activated human PMNs, antioxidant activity (scavenging of superoxide anion in a cell-free system) and inhibition of human complement (reducing levels of ROS by limiting formation of complement factors that attract and stimulate PMNs). For buckwheat honey (NewYork, US), moisture and free acid content were determined by refractive index measurement and potentiometric titration respectively. Honey constituents other than sugars were investigated by thin layer chromatography, using natural product reagent to detect phenolic compounds. Constituents with antioxidant properties were detected by spraying the chromatogram with DPPH. Although most honey samples were shown to be active, significant differences were observed, with the highly active honey exceeding the activities of samples with minor effects by factors of 4 to 30. Most pronounced activities were found for American buckwheat honey from the state of NewYork. Phenolic constituents of buckwheat honey were shown to have antioxidant activity. As buckwheat honey was most effective in reducing ROS levels, it was selected for use in wound-healing products. The major antioxidant properties in buckwheat honey derive from its phenolic constituents, which are present in relatively large amounts. Its phenolic compounds may also exert antibacterial activity, whereas its low pH and high free acid content may assist wound healing.

Macrophage activation syndrome associated with griscelli syndrome type 2: case report and review of literature

PubMed Central

Sefsafi, Zakia; Hasbaoui, Brahim El; Kili, Amina; Agadr, Aomar; Khattab, Mohammed

2018-01-01

Abstract Macrophage activation syndrome (MAS) is a severe and potentially fatal life-threatening condition associated with excessive activation and expansion of T cells with macrophages and a high expression of cytokines, resulting in an uncontrolled inflammatory response, with high levels of macrophage colony-stimulating factor and causing multiorgan damage. This syndrome is classified into primary (genetic/familial) or secondary forms to several etiologies, such as infections, neoplasias mainly hemopathies or autoimmune diseases. It is characterised clinically by unremitting high fever, pancytopaenia, hepatosplenomegaly, hepatic dysfunction, encephalopathy, coagulation abnormalities and sharply increased levels of ferritin. The pathognomonic feature of the syndrome is seen on bone marrow examination, which frequently, though not always, reveals numerous morphologically benign macrophages exhibiting haemophagocytic activity. Because MAS can follow a rapidly fatal course, prompt recognition of its clinical and laboratory features and immediate therapeutic intervention are essential. However, it is difficult to distinguish underlying disease flare, infectious complications or medication side effects from MAS. Although, the pathogenesis of MAS is unclear, the hallmark of the syndrome is an uncontrolled activation and proliferation of T lymphocytes and macrophages, leading to massive hypersecretion of pro-inflammatory cytokines. Mutations in cytolytic pathway genes are increasingly being recognised in children who develop MAS in his secondary form. We present here a case of Macrophage activation syndrome associated with Griscelli syndrome type 2 in a 3-years-old boy who had been referred due to severe sepsis with non-remitting high fever, generalized lymphoadenopathy and hepato-splenomegaly. Laboratory data revealed pancytopenia with high concentrations of triglycerides, ferritin and lactic dehydrogenase while the bone marrow revealed numerous morphologically benign macrophages with haemophagocytic activity that comforting the diagnosis of a SAM according to Ravelli and HLH-2004 criteria. Griscelli syndrome (GS) was evoked on; consanguineous family, recurrent infection, very light silvery-gray color of the hair and eyebrows, Light microscopy examination of the hair showed large, irregular clumps of pigments characteristic of GS. The molecular biology showed mutation in RAB27A gene confirming the diagnosis of a Griscelli syndrome type 2. The first-line therapy was based on the parenteral administration of high doses of corticosteroids, associated with immunosuppressive drugs, cyclosporine A and etoposide waiting for bone marrow transplantation (BMT). PMID:29875956

Lassomycin, a ribosomally synthesized cyclic peptide, kills Mycobacterium tuberculosis by targeting the ATP-dependent protease ClpC1P1P2

PubMed Central

Gavrish, Ekaterina; Sit, Clarissa S.; Cao, Shugeng; Kandror, Olga; Spoering, Amy; Peoples, Aaron; Ling, Losee; Fetterman, Ashley; Hughes, Dallas; Bissell, Anthony; Torrey, Heather; Akopian, Tatos; Mueller, Andreas; Epstein, Slava; Goldberg, Alfred; Clardy, Jon; Lewis, Kim

2014-01-01

Summary Languishing antibiotic discovery and flourishing antibiotic resistance have prompted development of alternative untapped sources for antibiotic discovery, including previously uncultured bacteria. Here, we screen extracts from uncultured species against M. tuberculosis and identify lassomycin, an antibiotic that exhibits potent bactericidal activity against both growing and dormant mycobacteria, including drug-resistant forms of M. tuberculosis, but little activity against other bacteria or mammalian cells. Lassomycin is a highly basic, ribosomally-encoded cyclic peptide with an unusual structural fold that only partially resembles that of other lasso peptides. We show that lassomycin binds to a highly acidic region of the ClpC1 ATPase complex and markedly stimulates its ATPase activity without stimulating ClpP1P2 catalyzed protein breakdown, which is essential for viability of mycobacteria. This mechanism, uncoupling ATPase from proteolytic activity, accounts for lassomycin's bacteriocidal activity. PMID:24684906

Intracellular NADPH Levels Affect the Oligomeric State of the Glucose 6-Phosphate Dehydrogenase

PubMed Central

Tramonti, Angela; Lanini, Claudio; Cialfi, Samantha; De Biase, Daniela; Falcone, Claudio

2012-01-01

In the yeast Kluyveromyces lactis, glucose 6-phosphate dehydrogenase (G6PDH) is detected as two differently migrating forms on native polyacrylamide gels. The pivotal metabolic role of G6PDH in K. lactis led us to investigate the mechanism controlling the two activities in respiratory and fermentative mutant strains. An extensive analysis of these mutants showed that the NAD+(H)/NADP+(H)-dependent cytosolic alcohol (ADH) and aldehyde (ALD) dehydrogenase balance affects the expression of the G6PDH activity pattern. Under fermentative/ethanol growth conditions, the concomitant activation of ADH and ALD activities led to cytosolic accumulation of NADPH, triggering an alteration in the oligomeric state of the G6PDH caused by displacement/release of the structural NADP+ bound to each subunit of the enzyme. The new oligomeric G6PDH form with faster-migrating properties increases as a consequence of intracellular redox unbalance/NADPH accumulation, which inhibits G6PDH activity in vivo. The appearance of a new G6PDH-specific activity band, following incubation of Saccharomyces cerevisiae and human cellular extracts with NADP+, also suggests that a regulatory mechanism of this activity through NADPH accumulation is highly conserved among eukaryotes. PMID:23064253

Electron beam enhanced surface modification for making highly resolved structures

DOEpatents

Pitts, John R.

1986-01-01

A method for forming high resolution submicron structures on a substrate is provided by direct writing with a submicron electron beam in a partial pressure of a selected gas phase characterized by the ability to dissociate under the beam into a stable gaseous leaving group and a reactant fragment that combines with the substrate material under beam energy to form at least a surface compound. Variations of the method provide semiconductor device regions on doped silicon substrates, interconnect lines between active sites, three dimensional electronic chip structures, electron beam and optical read mass storage devices that may include color differentiated data areas, and resist areas for use with selective etching techniques.

Electron beam enhanced surface modification for making highly resolved structures

DOEpatents

Pitts, J.R.

1984-10-10

A method for forming high resolution submicron structures on a substrate is provided by direct writing with a submicron electron beam in a partial pressure of a selected gas phase characterized by the ability to dissociate under the beam into a stable gaseous leaving group and a reactant fragment that combines with the substrate material under beam energy to form at least a surface compound. Variations of the method provide semiconductor device regions on doped silicon substrates, interconnect lines between active sites, three dimensional electronic chip structures, electron beam and optical read mass storage devices that may include color differentiated data areas, and resist areas for use with selective etching techniques.

Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites.

PubMed

Verlinden, Bianca K; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M; Birkholtz, Lyn-Marie

2015-08-15

A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kinetics and thermodynamics of the interchange of the morpheein forms of human porphobilinogen synthase.

PubMed

Selwood, Trevor; Tang, Lei; Lawrence, Sarah H; Anokhina, Yana; Jaffe, Eileen K

2008-03-11

A morpheein is a homo-oligomeric protein that can adopt different nonadditive quaternary assemblies (morpheein forms) with different functionalities. The human porphobilinogen synthase (PBGS) morpheein forms are a high activity octamer, a low activity hexamer, and two structurally distinct dimer conformations. Conversion between hexamer and octamer involves dissociation to dimers, conformational change at the dimer level, followed by association to the alternate assembly. The current work promotes an alternative and novel view of the physiologically relevant dimeric structures, which are derived from the crystal structures, but are distinct from the asymmetric units of their crystal forms. Using a well characterized heteromeric system (WT+F12L; Tang, L. et al. (2005) J. Biol. Chem. 280, 15786-15793), extensive study of the human PBGS morpheein reequilibration process now reveals that the intervening dimers do not dissociate to monomers. The morpheein equilibria of wild type (WT) human PBGS are found to respond to changes in pH, PBGS concentration, and substrate turnover. Notably, the WT enzyme is predominantly an octamer at neutral pH, but increasing pH results in substantial conversion to lower order oligomers. Most significantly, the free energy of activation for the conversion of WT+F12L human PBGS heterohexamers to hetero-octamers is determined to be the same as that for the catalytic conversion of substrate to product by the octamer, remarkably suggesting a common rate-limiting step for both processes, which is postulated to be the opening/closing of the active site lid.

Evidence for involvement of multiple forms of cytochrome P-450 in aflatoxin B sup 1 metabolism in human liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forrester, L.M.; Wolf, C.R.; Neal, G.E.

Liver cancer is a major cause of premature death in many areas of Africa and Asia and its incidence is strongly correlated with exposure to aflatoxin B{sub 1} (AFB{sub 1}). Because AFB{sub 1} requires metabolic activation to achieve a biological response, there is a need for detailed knowledge of the mechanism of activation to assess individual risk. The authors carried out an extensive study using a total of 19 human liver samples to determine the individual variability in the metabolism of the toxin to mutagenic or detoxification products and to identify the specific cytochrome P-450 forms involved in these processes.more » Metabolism to the toxic 8,9-epoxide or to products mutagenic in the Ames test was found to exhibit very large individual variation. These data demonstrate that, although P450IIIA probably plays an important role in AFB{sub 1} activation, several other cytochrome P-450 forms have the capacity to activate the toxin. Similar considerations apply to detoxifying metabolism to aflatoxin Q{sub 1} and aflatoxin M{sub 1}. The levels of expression of many of the forms of cytochrome P-450 involved in AFB{sub 1} metabolism are known to be highly sensitive to environmental factors. This indicates that such factors will be an important determinant in individual susceptibility to the tumorigenic action of AFB{sub 1}.« less

Whole body vibration therapy on a treatment bed as additional means to treat postprostatectomy urinary incontinence.

PubMed

Crevenna, Richard; Cenik, Fadime; Margreiter, Markus; Marhold, Maximilian; Sedghi Komanadj, Tanya; Keilani, Mohammad

2017-04-01

An innovative form of whole body vibration therapy on a treatment bed (Evocell®) to fight against the disabling and isolating symptom of postoperative incontinence in a prostate cancer patient is presented. A supervised program with outpatient active pelvic floor training and a novel form of synchronous high-intensity whole body vibration therapy using the Evocell® device was performed in a patient with postprostatectomy stress urinary incontinence. The patient had previously failed regular pelvic floor exercise. During the intervention, namely a whole body vibration treatment in a lying position on a treatment bed, the patient performed active and passive pelvic floor exercises under professional guidance. Over a period of 6 weeks after starting treatment, the patient regained continence (usage of 1 safety pad). Furthermore, his ability to work increased (return to work) and his ability to attend social activities improved.

Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides

NASA Astrophysics Data System (ADS)

Chen, Shiyu; Gopalakrishnan, Ranganath; Schaer, Tifany; Marger, Fabrice; Hovius, Ruud; Bertrand, Daniel; Pojer, Florence; Heinis, Christian

2014-11-01

The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.

Liking More Means Doing More

PubMed Central

Hepler, Justin; Albarracin, Dolores

2018-01-01

Dispositional attitudes are an individual difference in the tendency to form positive versus negative attitudes. As positive (negative) attitudes promote active (inactive) responses to stimuli, we predicted that dispositional attitudes would be positively correlated with patterns of general action. In Study 1, participants reported all activities they engaged in during a 1-week period using a structured time use survey. Dispositional attitudes were positively correlated with the number of unique behaviors participants engaged in and with the total number of behaviors reported for the entire week. Study 2 replicated Study 1 using a free response time use survey. Overall, the results demonstrated that dispositional attitudes predict general action, such that the tendency to form positive (negative) attitudes predicts the tendency to engage in many (few) behaviors in daily life. This pattern occurred for both low effort and high effort behaviors. Implications for understanding activity patterns are discussed. PMID:29375723

A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy

NASA Astrophysics Data System (ADS)

Lee, Hyunjae; Choi, Tae Kyu; Lee, Young Bum; Cho, Hye Rim; Ghaffari, Roozbeh; Wang, Liu; Choi, Hyung Jin; Chung, Taek Dong; Lu, Nanshu; Hyeon, Taeghwan; Choi, Seung Hong; Kim, Dae-Hyeong

2016-06-01

Owing to its high carrier mobility, conductivity, flexibility and optical transparency, graphene is a versatile material in micro- and macroelectronics. However, the low density of electrochemically active defects in graphene synthesized by chemical vapour deposition limits its application in biosensing. Here, we show that graphene doped with gold and combined with a gold mesh has improved electrochemical activity over bare graphene, sufficient to form a wearable patch for sweat-based diabetes monitoring and feedback therapy. The stretchable device features a serpentine bilayer of gold mesh and gold-doped graphene that forms an efficient electrochemical interface for the stable transfer of electrical signals. The patch consists of a heater, temperature, humidity, glucose and pH sensors and polymeric microneedles that can be thermally activated to deliver drugs transcutaneously. We show that the patch can be thermally actuated to deliver Metformin and reduce blood glucose levels in diabetic mice.

Phenylpropanoid 2,3-dioxygenase involved in the cleavage of the ferulic acid side chain to form vanillin and glyoxylic acid in Vanilla planifolia.

PubMed

Negishi, Osamu; Negishi, Yukiko

2017-09-01

Enzyme catalyzing the cleavage of the phenylpropanoid side chain was partially purified by ion exchange and gel filtration column chromatography after (NH 4 ) 2 SO 4 precipitation. Enzyme activities were dependent on the concentration of dithiothreitol (DTT) or glutathione (GSH) and activated by addition of 0.5 mM Fe 2+ . Enzyme activity for ferulic acid was as high as for 4-coumaric acid in the presence of GSH, suggesting that GSH acts as an endogenous reductant in vanillin biosynthesis. Analyses of the enzymatic reaction products with quantitative NMR (qNMR) indicated that an amount of glyoxylic acid (GA) proportional to vanillin was released from ferulic acid by the enzymatic reaction. These results suggest that phenylpropanoid 2,3-dioxygenase is involved in the cleavage of the ferulic acid side chain to form vanillin and GA in Vanilla planifolia.

Characterization of the interaction between the heavy and light chains of bovine factor Va.

PubMed

Walker, F J

1992-10-05

Bovine factor Va has been previously been shown to consist of heavy (M(r) = 94,000) and light chains (M(r) = 81,000), that interact in a manner dependent upon the presence of either calcium or manganese ions. In an attempt to understand the mechanism of subunit interaction we have studied the effects of temperature and ions on factor Va stability. The rates of formation of factor Va from isolated chains and dissociation were temperature-dependent with an energy of activation of 6.2 and 1.3 kcal mol-1, respectively. The yield of factor Va from isolated chains was inversely related to the amount of time the chains were incubated at 4 degrees C. Incubation of individual chains revealed that the heavy chain is cold-labile, an effect that is reversible. Manganese ion was observed to prevent the conversion to the inactive form. High salt tends to stabilize the two-chain structure of factor Va, but is inhibitory to its formation from isolated chains. High concentrations of either manganese or calcium ions also inhibited reconstitution of activity. The light chain, in particular, was sensitive to the presence of manganese or calcium ion. Heavy chain that had been cleaved by activated protein C had a weakened interaction with the light chain, and the resulting complex had no procoagulant activity. Cooling of the heavy chain to 4 degrees C enhanced its intrinsic fluorescence. Manganese ion prevented some of this enhancement. The heavy chain fluorescence returned to the room temperature value with a half-life of approximately 10 min. In the presence of manganese ion relaxation was accelerated. The intrinsic fluorescence of activated protein C-cleaved heavy chain was not increased when the temperature was decreased. These data suggest that the heavy chain can exist in two forms. Elevated temperature converts it to a form that can bind ions and have a productive interaction with the light chain. However, conditions that prevent the heavy chain from combining with the light chain also stabilize the two subunit structure, suggesting that the high affinity of the complex is due to conformational changes that occur after chain interaction.

Ab initio identification of the Li-rich phase in LiFePO4.

PubMed

Zeng, Hua; Gu, Yue; Teng, Gaofeng; Liu, Yimeng; Zheng, Jiaxin; Pan, Feng

2018-06-27

A recent discovery of anionic redox activity in Li-rich layered compounds opens a new direction for the design of high-capacity cathode materials for lithium-ion batteries. Here using extensive ab initio calculations, the thermodynamic existence of the Li-rich phase in LiFePO4 to form Li1+xFe1-xPO4 with x not exceeding 12.5% has been proved. Anionic redox activity and structural stability during delithiation are further investigated. Interestingly, it is found that Li1+xFe1-xPO4 cannot be delithiated completely and thus cannot achieve extra capacity by anionic redox activity, because the local oxygen-ion redox will cause the fracture of the rigid framework formed by phosphate tetrahedral polyanions. Although an extra capacity cannot be realized, the excess Li-ions at Fe sites can enhance the Li-ion diffusivity along the adjacent [010] channel and contribute to the shift from 1D to 2D/3D diffusion. This study provides a fresh perspective on olivine-type LiFePO4 and offers some important clues on designing Li-rich cathode materials with high energy density.

Degradation of ampicillin antibiotic by electrochemical processes: evaluation of antimicrobial activity of treated water.

PubMed

Vidal, Jorge; Huiliñir, Cesar; Santander, Rocío; Silva-Agredo, Javier; Torres-Palma, Ricardo A; Salazar, Ricardo

2018-05-17

Ampicillin (AMP) is an antibiotic widely used in hospitals and veterinary clinics around the world for treating infections caused by bacteria. Therefore, it is common to find traces of this antibiotic in wastewater from these entities. In this work, we studied the mineralization of this antibiotic in solution as well as the elimination of its antimicrobial activity by comparing different electrochemical advanced oxidation processes (EAOPs), namely electro-oxidation with hydrogen peroxide (EO-H 2 O 2 ), electro-Fenton (EF), and photo electro-Fenton (PEF). With PEF process, a high degradation, mineralization, and complete elimination of antimicrobial activity were achieved in 120-min electrolysis with high efficiency. In the PEF process, fast mineralization rate is caused by hydroxyl radicals (·OH) that are generated in the bulk, on the anode surface, by UV radiation, and most importantly, by the direct photolysis of complexes formed between Fe 3+ and some organic intermediates. Moreover, some products and intermediates formed during the degradation of the antibiotic Ampicillin, such as inorganic ions, carboxylic acids, and aromatic compounds, were determined by photometric and chromatographic methods. An oxidation pathway is proposed for the complete conversion to CO 2 .

Multivalency of Sonic hedgehog conjugated to linear polymer chains modulates protein potency.

PubMed

Wall, Samuel T; Saha, Krishanu; Ashton, Randolph S; Kam, Kimberly R; Schaffer, David V; Healy, Kevin E

2008-04-01

A potently active multivalent form of the protein Sonic hedgehog (Shh) was produced by bioconjugation of a modified recombinant form of Shh to the linear polymers poly(acrylic acid) (pAAc) and hyaluronic acid (HyA) via a two-step reaction exploiting carboimiide and maleimide chemistry. Efficiency of the conjugation was approximately 75% even at stoichiometric ratios of 30 Shh molecules per linear HyA chain (i.e., 30:1 Shh/HyA). Bioactivity of the conjugates was tested via a cellular assay across a range of stoichiometric ratios of Shh molecules to HyA linear chains, which was varied from 0.6:1 Shh/HyA to 22:1 Shh/HyA. Results indicate that low conjugation ratios decrease Shh bioactivity and high ratios increase this activity beyond the potency of monomeric Shh, with approximately equal activity between monomeric soluble Shh and conjugated Shh at 7:1 Shh/HyA. In addition, high-ratio constructs increased angiogenesis determined by the in vivo chick chorioallantoic membrane (CAM) assay. These results are captured by a kinetic model of multiple interactions between the Shh/HyA conjugates and cell surface receptors resulting in higher cell signaling at lower bulk Shh concentrations.

Tandem phosphorylation of Ser-911 and Thr-912 at the C terminus of yeast plasma membrane H+-ATPase leads to glucose-dependent activation.

PubMed

Lecchi, Silvia; Nelson, Clark J; Allen, Kenneth E; Swaney, Danielle L; Thompson, Katie L; Coon, Joshua J; Sussman, Michael R; Slayman, Carolyn W

2007-12-07

In recent years there has been growing interest in the post-translational regulation of P-type ATPases by protein kinase-mediated phosphorylation. Pma1 H(+)-ATPase, which is responsible for H(+)-dependent nutrient uptake in yeast (Saccharomyces cerevisiae), is one such example, displaying a rapid 5-10-fold increase in activity when carbon-starved cells are exposed to glucose. Activation has been linked to Ser/Thr phosphorylation in the C-terminal tail of the ATPase, but the specific phosphorylation sites have not previously been mapped. The present study has used nanoflow high pressure liquid chromatography coupled with electrospray electron transfer dissociation tandem mass spectrometry to identify Ser-911 and Thr-912 as two major phosphorylation sites that are clearly related to glucose activation. In carbon-starved cells with low Pma1 activity, peptide 896-918, which was derived from the C terminus upon Lys-C proteolysis, was found to be singly phosphorylated at Thr-912, whereas in glucose-metabolizing cells with high ATPase activity, the same peptide was doubly phosphorylated at Ser-911 and Thr-912. Reciprocal (14)N/(15)N metabolic labeling of cells was used to measure the relative phosphorylation levels at the two sites. The addition of glucose to carbon-starved cells led to a 3-fold reduction in the singly phosphorylated form and an 11-fold increase in the doubly phosphorylated form. These results point to a mechanism in which the stepwise phosphorylation of two tandemly positioned residues near the C terminus mediates glucose-dependent activation of the H(+)-ATPase.