Estimation of sesqui-carbide fraction for MARK-I fuel

International Nuclear Information System (INIS)

Vana Varamban, S.; Ananthasivan, K.

2016-01-01

Sesqui-carbide content of FBTR bi-phasic mixed carbide is specified as 5-20 wt.%. For each batch of fuel production, the sesqui-carbide (M2C3) content is being determined by a K-ratio method using XRD information. There is a need to evolve an alternate method for qualitative determination of M2C3 content for a fabricated FBTR fuel pellet. Two independent approaches resulted in a correlation between overall carbon content and the M2C3 phase fraction. The thermodynamic calculations agree well with the stoichiometric correlation between the overall carbon content and the M2C3 phase fraction in FBTR MARK I fuel

A re-examination of the biphasic theory of skeletal muscle growth.

Science.gov (United States)

Levine, A S; Hegarty, P V

1977-01-01

Because of the importance of fibre diameter measurements it was decided to re-evaluate the biphasic theory of skeletal muscle growth and development. This theory proposes an initial memophasic distribution of muscle fibres which changes to a biphasic distribution during development. The theory is based on observations made on certain muscles in mice, where two distinct populations of fibre diameters (20 and 40 micronm) contribute to the biphasic distribution. In the present investigation corss sections of frozen biceps brachii of mice in rigor mortis were examined. The rigor state was used to avoid complications produced by thaw-rigor contraction. The diameters of the outermost and innermost fibres were found to be significantly different. However, if the outer and inner fibres were combined to form one group, no significant difference between this group and other random groups was found. The distributions of all groups were monophasic. The diameters of isolated fibres from mice and rats also displayed a monophasic distribution. This evidence leads to the conclusion that the biphasic theory of muscle growth is untenable. Some of the variables which may occur in fibre size and shape are discussed. Images Fig. 1 PMID:858691

Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

Directory of Open Access Journals (Sweden)

Lukasz Makowski

2016-11-01

Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

Three dimensional biphasic calcium phosphate nanocomposites for load bearing bioactive bone grafts

Energy Technology Data Exchange (ETDEWEB)

Garai, Subhadra, E-mail: subha@nmlindia.org; Sinha, Arvind

2016-02-01

Mimicking matrix mediated bio-mineralization process, three dimensional blocks of biphasic calcium phosphate (BCP, hydroxyapatite (HA) and β-tricalcium phosphate (TCP)) nanocomposites, having three different stoichiometries have been synthesized for possible application as load bearing synthetic bone graft or scaffolds. Biphasic blocks with three weight ratios of 20:80, 25:75 and 30:70 of HA and TCP respectively have been synthesized. Detailed structural and chemical characterization of the samples revealed a strong dependence of porosity and mechanical properties on the stoichiometry of biphasic blocks. Effect of physiological medium on the microstructure and mechanical properties of the three different blocks has also been studied. Bioactivity of the BCP block, exhibiting highest compressive strength in air as well as in physiological medium, has been evaluated through adhesion, proliferation and differentiation of mesenchymal stem cells using different markers. - Highlights: • Developed a process for the synthesis of load bearing 3d- biphasic nanocomposites. • Synthesized nanocomposites exhibited in vitro osteoconductivity and osteoinductivity for bone marrow mesenchymal cells. • Developed process is a matrix mediated biomimetic one.

Preparation and Characterization of Apatitic Biphasic Calcium Phosphate

International Nuclear Information System (INIS)

Thin Thin Nwe; Kyaw Naing; Khin Mar Tun; Nyunt Wynn

2005-09-01

The apatitic biphasic calcium phosphate (ABcp) consisting of hydroxyapatite (HA) and -tricalcium phosphate ( -Tcp) has been prepared by precipitation technique using slaked lime and orthophosphoric acid. The X-ray diffraction analysis of the product I (hydroxyapatite) revealed that ABcp was partially crystalline state. However, on heating at 800 C for 8 hrs, XRD pattern indicated a perfectly crystalline form of ABcp. This observation was supported by FT-IR measurement. The change in morphology regarding in the functional nature was infered by the shift in the FT-IR frequency. The optimization of the apatitic biphasic calcium phosphate was done by the variation of disodium hydrogen phosphate concentration, setting time, hardening time as well as compressive strength. The perpared cement may be used as an artificial substitution bone

The standard biphasic-contrast examination of the stomach and duodenum

International Nuclear Information System (INIS)

Op den Orth, J.O.

1979-01-01

A standard examination has been developed, called biphasic, because it combines the advantages of positive-contrast and double-contrast techniques. The theoretical background and technique of this examination are described and the basic interpretation of double-contrast studies stated. General remarks on the results and on the complementary role of radiological examination and endoscopy are included. A quantitative study of standard biphasic-contrast examinations in patients over a period of 3 years is presented. Finally a radiological atlas of common lesions of the stomach and duodenum is given. (C.F.)

Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

Science.gov (United States)

Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

2016-01-01

Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

Transgene Expression and Host Cell Responses to Replication-Defective, Single-Cycle, and Replication-Competent Adenovirus Vectors

Directory of Open Access Journals (Sweden)

Catherine M. Crosby

2017-02-01

Full Text Available Most adenovirus (Ad vectors are E1 gene deleted replication defective (RD-Ad vectors that deliver one transgene to the cell and all expression is based on that one gene. In contrast, E1-intact replication-competent Ad (RC-Ad vectors replicate their DNA and their transgenes up to 10,000-fold, amplifying transgene expression markedly higher than RD-Ad vectors. While RC-Ad are more potent, they run the real risk of causing adenovirus infections in vector recipients and those that administer them. To gain the benefits of transgene amplification, but avoid the risk of Ad infections, we developed “single cycle” Ad (SC-Ad vectors. SC-Ads amplify transgene expression and generated markedly stronger and more persistent immune responses than RD-Ad as expected. However, they also unexpectedly generated stronger immune responses than RC-Ad vectors. To explore the basis of this potency here, we compared gene expression and the cellular responses to infection to these vectors in vitro and in vivo. In vitro, in primary human lung epithelial cells, SC- and RC-Ad amplified their genomes more than 400-fold relative to RD-Ad with higher replication by SC-Ad. This replication translated into higher green fluorescent protein (GFP expression for 48 h by SC- and RC-Ad than by RD-Ad. In vitro, in the absence of an immune system, RD-Ad expression became higher by 72 h coincident with cell death mediated by SC- and RC-Ad and release of transgene product from the dying cells. When the vectors were compared in human THP-1 Lucia- interferon-stimulated gene (ISG cells, which are a human monocyte cell line that have been modified to quantify ISG activity, RC-Ad6 provoked significantly stronger ISG responses than RD- or SC-Ad. In mice, intravenous or intranasal injection produced up to 100-fold genome replication. Under these in vivo conditions in the presence of the immune system, luciferase expression by RC and SC-Ad was markedly higher than that by RD-Ad. In

Low-High and High-Low Biphasic Injection Forms in Computed Tomography Examinations of the Upper Abdomen

International Nuclear Information System (INIS)

Marti-Bonmati, L.; Arana, E.; Tobarra, E.; Sierra, C.

2006-01-01

Purpose: To analyze the influence of different biphasic and monophasic injection rate protocols in abdominal computed tomography (CT). Material and Methods: A randomized, consecutive, parallel group study was designed and conducted in 60 patients studied with the same CT helical protocol. Patients were randomly distributed into three groups: (A) monophasic (120 ml at 2.5 ml/s); (B) low-high biphasic (120 ml, first 60 ml at a rate of 2 ml/s, the other 60 ml at 2.5 ml/s); and (C) high-low biphasic (120 ml, first 60 ml at a rate of 2.5 ml/s, the other 60 ml at 2 ml/s). All patients were injected with 300 mg I/ml non-ionic contrast media at a fixed delay time of 55 s. Contrast enhancement efficacy was evaluated by attenuation coefficient measurements. Results: Although non-significant, monophasic protocol enhancements were higher than biphasic protocol enhancements in all measurements except aortic bifurcation (p = 0.003). At this level, biphasic protocols obtained an increased mean enhancement from 7.6% to 2.5% compared to monophasic protocols. Conclusion: Monophasic contrast agent injection in helical CT of the upper abdomen produces a higher enhancement of parenchymal and venous structures. No significant difference was observed between low-high and high-low biphasic protocols

Dissolved nutrients and atrazine removal by column-scale monophasic and biphasic rain garden model systems.

Science.gov (United States)

Yang, Hanbae; McCoy, Edward L; Grewal, Parwinder S; Dick, Warren A

2010-08-01

Rain gardens are bioretention systems that have the potential to reduce peak runoff flow and improve water quality in a natural and aesthetically pleasing manner. We compared hydraulic performance and removal efficiencies of nutrients and atrazine in a monophasic rain garden design versus a biphasic design at a column-scale using simulated runoff. The biphasic rain garden was designed to increase retention time and removal efficiency of runoff pollutants by creating a sequence of water saturated to unsaturated conditions. We also evaluated the effect of C substrate availability on pollutant removal efficiency in the biphasic rain garden. Five simulated runoff events with various concentrations of runoff pollutants (i.e. nitrate, phosphate, and atrazine) were applied to the monophasic and biphasic rain gardens once every 5d. Hydraulic performance was consistent over the five simulated runoff events. Peak flow was reduced by approximately 56% for the monophasic design and 80% for the biphasic design. Both rain garden systems showed excellent removal efficiency of phosphate (89-100%) and atrazine (84-100%). However, significantly (prain garden (29-39%). Addition of C substrate in the form of glucose increased removal efficiency of nitrate significantly (prain gardens. (c) 2010 Elsevier Ltd. All rights reserved.

Hydroxyapatite/polylactide biphasic combination scaffold loaded with dexamethasone for bone regeneration.

Science.gov (United States)

Son, Jun-Sik; Kim, Su-Gwan; Oh, Ji-Su; Appleford, Mark; Oh, Sunho; Ong, Joo L; Lee, Kyu-Bok

2011-12-15

This study presents a novel design of a ceramic/polymer biphasic combination scaffold that mimics natural bone structures and is used as a bone graft substitute. To mimic the natural bone structures, the outside cortical-like shells were composed of porous hydroxyapatite (HA) with a hollow interior using a polymeric template-coating technique; the inner trabecular-like core consisted of porous poly(D,L-lactic acid) (PLA) that was loaded with dexamethasone (DEX) and was directly produced using a particle leaching/gas forming technique to create the inner diameter of the HA scaffold. It was observed that the HA and PLA parts of the fabricated HA/PLA biphasic scaffold contained open and interconnected pore structures, and the boundary between both parts was tightly connected without any gaps. It was found that the structure of the combination scaffold was analogous to that of natural bone based on micro-computed tomography analysis. Additionally, the dense, uniform apatite layer was formed on the surface of the HA/PLA biphasic scaffold through a biomimetic process, and DEX was successfully released from the PLA of the biphasic scaffold over a 1-month period. This release caused human embryonic palatal mesenchyme cells to proliferate, differentiate, produce ECM, and form tissue in vitro. Therefore, it was concluded that this functionally graded scaffold is similar to natural bone and represents a potential bone-substitute material. Copyright © 2011 Wiley Periodicals, Inc.

Replication stress, a source of epigenetic aberrations in cancer?

DEFF Research Database (Denmark)

Jasencakova, Zusana; Groth, Anja

2010-01-01

. Chromatin organization is transiently disrupted during DNA replication and maintenance of epigenetic information thus relies on faithful restoration of chromatin on the new daughter strands. Acute replication stress challenges proper chromatin restoration by deregulating histone H3 lysine 9 mono......-methylation on new histones and impairing parental histone recycling. This could facilitate stochastic epigenetic silencing by laying down repressive histone marks at sites of fork stalling. Deregulation of replication in response to oncogenes and other tumor-promoting insults is recognized as a significant source...... of genome instability in cancer. We propose that replication stress not only presents a threat to genome stability, but also jeopardizes chromatin integrity and increases epigenetic plasticity during tumorigenesis....

Biphasic Malignant Pleural Mesothelioma Masquerading as a Primary Skeletal Tumor

Directory of Open Access Journals (Sweden)

James Benjamin Gleason

2016-01-01

Full Text Available Biphasic malignant pleural mesothelioma is a rare malignant tumor, usually presenting as a pleural-based mass in a patient with history of chronic asbestos exposure. We herein report a case of a 41-year-old man who presented with chest pain and had a chest computed tomography (CT scan suggestive of a primary skeletal tumor originating from the ribs (chondrosarcoma or osteosarcoma, with no history of asbestos exposure. CT-guided core needle biopsies were diagnosed as malignant sarcomatoid mesothelioma. Surgical resection and chest wall reconstruction were performed, confirming the diagnosis and revealing a secondary histologic component (epithelioid, supporting the diagnosis of biphasic malignant mesothelioma.

Operation and Performance of a Biphase Turbine Power Plant at the Cerro Prieto Geothermal Field (Final Report)

Energy Technology Data Exchange (ETDEWEB)

Hays, Lance G. [Douglas Energy Company, Placentia, CA (United States)

2000-09-01

A full scale, wellhead Biphase turbine was manufactured and installed with the balance of plant at Well 103 of the Cerro Prieto geothermal resource in Baja, California. The Biphase turbine was first synchronized with the electrical grid of Comision Federal de Electricidad on August 20, 1997. The Biphase power plant was operated from that time until May 23, 2000, a period of 2 years and 9 months. A total of 77,549 kWh were delivered to the grid. The power plant was subsequently placed in a standby condition pending replacement of the rotor with a newly designed, higher power rotor and replacement of the bearings and seals. The maximum measured power output of the Biphase turbine, 808 kWe at 640 psig wellhead pressure, agreed closely with the predicted output, 840 kWe. When combined with the backpressure steam turbine the total output power from that flow would be increased by 40% above the power derived only from the flow by the present flash steam plant. The design relations used to predict performance and design the turbine were verified by these tests. The performance and durability of the Biphase turbine support the conclusion of the Economics and Application Report previously published, (Appendix A). The newly designed rotor (the Dual Pressure Rotor) was analyzed for the above power condition. The Dual Pressure Rotor would increase the power output to 2064 kWe by incorporating two pressure letdown stages in the Biphase rotor, eliminating the requirement for a backpressure steam turbine. The power plant availability was low due to deposition of solids from the well on the Biphase rotor and balance of plant problems. A great deal of plant down time resulted from the requirement to develop methods to handle the solids and from testing the apparatus in the Biphase turbine. Finally an online, washing method using the high pressure two-phase flow was developed which completely eliminated the solids problem. The availability of the Biphase turbine itself was 100

Biphasic Clinical Course Among Kenyan Children With Cerebral ...

African Journals Online (AJOL)

Background Cerebral malaria is the most severe neurological complication of Falciparum malaria. It is associated with a significant risk of death and neurological sequelae. A biphasic clinical picture is associated with an even greater risk of neurological sequelae. Objective To examine the incidence and clinical ...

Chromatin replication and histone dynamics

DEFF Research Database (Denmark)

Alabert, Constance; Jasencakova, Zuzana; Groth, Anja

2017-01-01

Inheritance of the DNA sequence and its proper organization into chromatin is fundamental for genome stability and function. Therefore, how specific chromatin structures are restored on newly synthesized DNA and transmitted through cell division remains a central question to understand cell fate...... choices and self-renewal. Propagation of genetic information and chromatin-based information in cycling cells entails genome-wide disruption and restoration of chromatin, coupled with faithful replication of DNA. In this chapter, we describe how cells duplicate the genome while maintaining its proper...... organization into chromatin. We reveal how specialized replication-coupled mechanisms rapidly assemble newly synthesized DNA into nucleosomes, while the complete restoration of chromatin organization including histone marks is a continuous process taking place throughout the cell cycle. Because failure...

Transcriptional repression is epigenetically marked by H3K9 methylation during SV40 replication

OpenAIRE

Kallestad, Les; Christensen, Kendra; Woods, Emily; Milavetz, Barry

2014-01-01

Background We have recently shown that T-antigen binding to Site I results in the replication-dependent introduction of H3K9me1 into SV40 chromatin late in infection. Since H3K9me2 and H3K9me3 are also present late in infection, we determined whether their presence was also related to the status of ongoing transcription and replication. Transcription was either inhibited with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidizole (DRB) or stimulated with sodium butyrate and the effects on histone m...

Megabase replication domains along the human genome: relation to chromatin structure and genome organisation.

Science.gov (United States)

Audit, Benjamin; Zaghloul, Lamia; Baker, Antoine; Arneodo, Alain; Chen, Chun-Long; d'Aubenton-Carafa, Yves; Thermes, Claude

2013-01-01

In higher eukaryotes, the absence of specific sequence motifs, marking the origins of replication has been a serious hindrance to the understanding of (i) the mechanisms that regulate the spatio-temporal replication program, and (ii) the links between origins activation, chromatin structure and transcription. In this chapter, we review the partitioning of the human genome into megabased-size replication domains delineated as N-shaped motifs in the strand compositional asymmetry profiles. They collectively span 28.3% of the genome and are bordered by more than 1,000 putative replication origins. We recapitulate the comparison of this partition of the human genome with high-resolution experimental data that confirms that replication domain borders are likely to be preferential replication initiation zones in the germline. In addition, we highlight the specific distribution of experimental and numerical chromatin marks along replication domains. Domain borders correspond to particular open chromatin regions, possibly encoded in the DNA sequence, and around which replication and transcription are highly coordinated. These regions also present a high evolutionary breakpoint density, suggesting that susceptibility to breakage might be linked to local open chromatin fiber state. Altogether, this chapter presents a compartmentalization of the human genome into replication domains that are landmarks of the human genome organization and are likely to play a key role in genome dynamics during evolution and in pathological situations.

Actinide recovery using aqueous biphasic extraction: Initial developmental studies

International Nuclear Information System (INIS)

Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

1992-08-01

Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less

Actinide recovery using aqueous biphasic extraction: Initial developmental studies

Energy Technology Data Exchange (ETDEWEB)

Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

1992-08-01

Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

Deep eutectic solvents as performance additives in biphasic reactions

NARCIS (Netherlands)

Lan, Dongming; Wang, Xuping; Zhou, Pengfei; Hollmann, F.; Wang, Yonghua

2017-01-01

Deep eutectic solvents act as surfactants in biphasic (hydrophobic/aqueous) reaction mixtures enabling higher interfacial surface areas at lower mechanical stress as compared to simple emulsions. Exploiting this effect the rate of a chemoenzymatic epoxidation reaction was increased more than

Modeling and predictions of biphasic mechanosensitive cell migration altered by cell-intrinsic properties and matrix confinement.

Science.gov (United States)

Pathak, Amit

2018-04-12

Motile cells sense the stiffness of their extracellular matrix (ECM) through adhesions and respond by modulating the generated forces, which in turn lead to varying mechanosensitive migration phenotypes. Through modeling and experiments, cell migration speed is known to vary with matrix stiffness in a biphasic manner, with optimal motility at an intermediate stiffness. Here, we present a two-dimensional cell model defined by nodes and elements, integrated with subcellular modeling components corresponding to mechanotransductive adhesion formation, force generation, protrusions and node displacement. On 2D matrices, our calculations reproduce the classic biphasic dependence of migration speed on matrix stiffness and predict that cell types with higher force-generating ability do not slow down on very stiff matrices, thus disabling the biphasic response. We also predict that cell types defined by lower number of total receptors require stiffer matrices for optimal motility, which also limits the biphasic response. For a cell type with robust biphasic migration on 2D surface, simulations in channel-like confined environments of varying width and height predict faster migration in more confined matrices. Simulations performed in shallower channels predict that the biphasic mechanosensitive cell migration response is more robust on 2D micro-patterns as compared to the channel-like 3D confinement. Thus, variations in the dimensionality of matrix confinement alters the way migratory cells sense and respond to the matrix stiffness. Our calculations reveal new phenotypes of stiffness- and topography-sensitive cell migration that critically depend on both cell-intrinsic and matrix properties. These predictions may inform our understanding of various mechanosensitive modes of cell motility that could enable tumor invasion through topographically heterogeneous microenvironments. © 2018 IOP Publishing Ltd.

Pretreatment of Eucalyptus in biphasic system for furfural production and accelerated enzymatic hydrolysis.

Science.gov (United States)

Zhang, Xiudong; Bai, Yuanyuan; Cao, Xuefei; Sun, Runcang

2017-08-01

Herein, an efficient biphasic pretreatment process was developed to improve the production of furfural (FF) and glucose from Eucalyptus. The influence of formic acid and NaCl on FF production from xylose in water and various biphasic systems was investigated. Results showed that the addition of formic acid and NaCl significantly promoted the FF yield, and the biphasic system of MIBK (methyl isobutyl ketone)/water exhibited the best performance for FF production. Then the Eucalyptus was pretreated in the MIBK/water system, and a maximum FF yield of 82.0% was achieved at 180°C for 60min. Surface of the pretreated Eucalyptus became relatively rough and loose, and its crystallinity index increased obviously due to the removal of hemicelluloses and lignin. The pretreated Eucalyptus samples showed much higher enzymatic hydrolysis rates (26.2-70.7%) than the raw Eucalyptus (14.5%). Copyright © 2017 Elsevier Ltd. All rights reserved.

H3S10ph broadly marks early-replicating domains in interphase ESCs and shows reciprocal antagonism with H3K9me2.

Science.gov (United States)

Chen, Carol C L; Goyal, Preeti; Karimi, Mohammad M; Abildgaard, Marie H; Kimura, Hiroshi; Lorincz, Matthew C

2018-01-01

Phosphorylation of histone H3 at serine 10 (H3S10ph) by Aurora kinases plays an important role in mitosis; however, H3S10ph also marks regulatory regions of inducible genes in interphase mammalian cells, implicating mitosis-independent functions. Using the fluorescent ubiquitin-mediated cell cycle indicator (FUCCI), we found that 30% of the genome in interphase mouse embryonic stem cells (ESCs) is marked with H3S10ph. H3S10ph broadly demarcates gene-rich regions in G1 and is positively correlated with domains of early DNA replication timing (RT) but negatively correlated with H3K9me2 and lamin-associated domains (LADs). Consistent with mitosis-independent kinase activity, this pattern was preserved in ESCs treated with Hesperadin, a potent inhibitor of Aurora B/C kinases. Disruption of H3S10ph by expression of nonphosphorylatable H3.3S10A results in ectopic spreading of H3K9me2 into adjacent euchromatic regions, mimicking the phenotype observed in Drosophila JIL-1 kinase mutants . Conversely, interphase H3S10ph domains expand in Ehmt1 (also known as Glp ) null ESCs, revealing that H3S10ph deposition is restricted by H3K9me2. Strikingly, spreading of H3S10ph at RT transition regions (TTRs) is accompanied by aberrant transcription initiation of genes co-oriented with the replication fork in Ehmt1 -/- and Ehmt2 -/- ESCs, indicating that establishment of repressive chromatin on the leading strand following DNA synthesis may depend upon these lysine methyltransferases. H3S10ph is also anti-correlated with H3K9me2 in interphase murine embryonic fibroblasts (MEFs) and is restricted to intragenic regions of actively transcribing genes by EHMT2. Taken together, these observations reveal that H3S10ph may play a general role in restricting the spreading of repressive chromatin in interphase mammalian cells. © 2018 Chen et al.; Published by Cold Spring Harbor Laboratory Press.

Paired associative stimulation targeting the tibialis anterior muscle using either mono or biphasic transcranial magnetic stimulation

DEFF Research Database (Denmark)

Mrachacz-Kersting, Natalie; Stevenson, Andrew James Thomas

2017-01-01

Paired associative stimulation (PAS) protocols induce plastic changes within the motor cortex. The objectives of this study were to investigate PAS effects targeting the tibialis anterior (TA) muscle using a biphasic transcranial magnetic stimulation (TMS) pulse form and, to determine whether...... a reduced intensity of this pulse would lead to significant changes as has been reported for hand muscles using a monophasic TMS pulse. Three interventions were investigated: (1) suprathreshold PAbi-PAS (n = 11); (2) suprathreshold PAmono-PAS (n = 11) where PAS was applied using a biphasic or monophasic......% for subthreshold PAbi-PAS. PAS using a biphasic pulse form at subthreshold intensities induces similar effects to conventional PAS....

A transgenic mouse marking live replicating cells reveals in vivo transcriptional program of proliferation

DEFF Research Database (Denmark)

Klochendler, Agnes; Weinberg-Corem, Noa; Moran, Maya

2012-01-01

Most adult mammalian tissues are quiescent, with rare cell divisions serving to maintain homeostasis. At present, the isolation and study of replicating cells from their in vivo niche typically involves immunostaining for intracellular markers of proliferation, causing the loss of sensitive biolo...

Cell–material interactions on biphasic polyurethane matrix

Science.gov (United States)

Dicesare, Patrick; Fox, Wade M.; Hill, Michael J.; Krishnan, G. Rajesh; Yang, Shuying; Sarkar, Debanjan

2013-01-01

Cell–matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell–matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration. PMID:23255285

Fabrication and tritium release property of Li2TiO3-Li4SiO4 biphasic ceramics

Science.gov (United States)

Yang, Mao; Ran, Guangming; Wang, Hailiang; Dang, Chen; Huang, Zhangyi; Chen, Xiaojun; Lu, Tiecheng; Xiao, Chengjian

2018-05-01

Li2TiO3-Li4SiO4 biphasic ceramic pebbles have been developed as an advanced tritium breeder due to the potential to combine the advantages of both Li2TiO3 and Li4SiO4. Wet method was developed for the pebble fabrication and Li2TiO3-Li4SiO4 biphasic ceramic pebbles were successfully prepared by wet method using the powders synthesized by hydrothermal method. The tritium release properties of the Li2TiO3-Li4SiO4 biphasic ceramic pebbles were evaluated. The biphasic pebbles exhibited good tritium release property at low temperatures and the tritium release temperature was around 470 °C. Because of the isotope exchange reaction between H2 and tritium, the addition of 0.1%H2 to purge gas He could significantly enhance the tritium gas release and the fraction of molecular form of tritium increased from 28% to 55%. The results indicate that the Li2TiO3-Li4SiO4 biphasic ceramic pebbles fabricated by wet method exhibit good tritium release property and hold promising potential as advanced breeder pebbles.

Biphase sinusoidal oscillator based on negative resistor.

Science.gov (United States)

Bayard, Jean

2010-06-01

This paper describes a biphase sinusoidal generator which provides two signals: v(ref)=V(M) sin(omegat) and v(out)=V(M) sin(omegat+DeltaPhi), where DeltaPhi is in the range 0, pi/2 or -pi/2, 0 and is not dependent on the frequency value. It is based on a negative resistor and it requires very few components. SPICE simulations and measurements on an experimental setup confirm the theoretical analysis.

A New Type of Biphasic Calcium Phosphate Cement as a Gentamicin Carrier for Osteomyelitis

Directory of Open Access Journals (Sweden)

Wen-Yu Su

2013-01-01

Full Text Available Osteomyelitis therapy is a long-term and inconvenient procedure for a patient. Antibiotic-loaded bone cements are both a complementary and alternative treatment option to intravenous antibiotic therapy for the treatment of osteomyelitis. In the current study, the biphasic calcium phosphate cement (CPC, called α-TCP/HAP (α-tricalcium phosphate/hydroxyapatite biphasic cement, was prepared as an antibiotics carrier for osteomyelitis. The developed biphasic cement with a microstructure of α-TCP surrounding the HAP has a fast setting time which will fulfill the clinical demand. The X-ray diffraction and Fourier transform infrared spectrometry analyses showed the final phase to be HAP, the basic bone mineral, after setting for a period of time. Scanning electron microscopy revealed a porous structure with particle sizes of a few micrometers. The addition of gentamicin in α-TCP/HAP would delay the transition of α-TCP but would not change the final-phase HAP. The gentamicin-loaded α-TCP/HAP supplies high doses of the antibiotic during the initial 24 hours when they are soaked in phosphate buffer solution (PBS. Thereafter, a slower drug release is produced, supplying minimum inhibitory concentration until the end of the experiment (30 days. Studies of growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa in culture indicated that gentamicin released after 30 days from α-TCP/HAP biphasic cement retained antibacterial activity.

H3K56me1 marks a spot for PCNA

DEFF Research Database (Denmark)

Lee, Sung-Po; Jasencakova, Zusana; Groth, Anja

2012-01-01

In the current issue of Molecular Cell, Yu et al. (2012) establish H3K56 monomethylation (H3K56me1) as a new mammalian chromatin mark, imposed by the G9a methyltransferase and recognized by the replication clamp PCNA....

Lipase in biphasic alginate beads as a biocatalyst for esterification of butyric acid and butanol in aqueous media.

Science.gov (United States)

Ng, Choong Hey; Yang, Kun-Lin

2016-01-01

Esterification of organic acids and alcohols in aqueous media is very inefficient due to thermodynamic constraints. However, fermentation processes used to produce organic acids and alcohols are often conducted in aqueous media. To produce esters in aqueous media, biphasic alginate beads with immobilized lipase are developed for in situ esterification of butanol and butyric acid. The biphasic beads contain a solid matrix of calcium alginate and hexadecane together with 5 mg/mL of lipase as the biocatalyst. Hexadecane in the biphasic beads serves as an organic phase to facilitate the esterification reaction. Under optimized conditions, the beads are able to catalyze the production of 0.16 mmol of butyl butyrate from 0.5 mmol of butyric acid and 1.5 mmol of butanol. In contrast, when monophasic beads (without hexadecane) are used, only trace amount of butyl butyrate is produced. One main application of biphasic beads is in simultaneous fermentation and esterification (SFE) because the organic phase inside the beads is very stable and does not leach out into the culture medium. SFE is successfully conducted with an esterification yield of 6.32% using biphasic beads containing iso-octane even though the solvent is proven toxic to the butanol-producing Clostridium spp. Copyright © 2015 Elsevier Inc. All rights reserved.

A new kinetic biphasic approach applied to biodiesel process intensification

Energy Technology Data Exchange (ETDEWEB)

Russo, V.; Tesser, R.; Di Serio, M.; Santacesaria, E. [Naples Univ. (Italy). Dept. of Chemistry

2012-07-01

Many different papers have been published on the kinetics of the transesterification of vegetable oil with methanol, in the presence of alkaline catalysts to produce biodiesel. All the proposed approaches are based on the assumption of a pseudo-monophasic system. The consequence of these approaches is that some experimental aspects cannot be described. For the reaction performed in batch conditions, for example, the monophasic approach is not able to reproduce the different plateau obtained by using different amount of catalyst or the induction time observed at low stirring rates. Moreover, it has been observed by operating in continuous reactors that micromixing has a dramatic effect on the reaction rate. At this purpose, we have recently observed that is possible to obtain a complete conversion to biodiesel in less than 10 seconds of reaction time. This observation is confirmed also by other authors using different types of reactors like: static mixers, micro-reactors, oscillatory flow reactors, cavitational reactors, microwave reactors or centrifugal contactors. In this work we will show that a recently proposed biphasic kinetic approach is able to describe all the aspects before mentioned that cannot be described by the monophasic kinetic model. In particular, we will show that the biphasic kinetic model can describe both the induction time observed in the batch reactors, at low stirring rate, and the very high conversions obtainable in a micro-channel reactor. The adopted biphasic kinetic model is based on a reliable reaction mechanism that will be validated by the experimental evidences reported in this work. (orig.)

In vitro study on biomineralization of biphasic calcium phosphate ...

Indian Academy of Sciences (India)

In this study, we report the preparation of a bone graft material, having cylindrical shape, containing biphasic calcium phosphate (BCP), gelatin (G), chitosan (C) and Terminalia chebula (TC) extract. TC extract was used as a crosslinker that gives stability to bone graft when it is placed in SBF. The graft was stable in the SBF ...

Biphasic papillary renal cell carcinoma is a rare morphological variant with frequent multifocality: a study of 28 cases.

Science.gov (United States)

Trpkov, Kiril; Athanazio, Daniel; Magi-Galluzzi, Cristina; Yilmaz, Helene; Clouston, David; Agaimy, Abbas; Williamson, Sean R; Brimo, Fadi; Lopez, Jose I; Ulamec, Monika; Rioux-Leclercq, Nathalie; Kassem, Maysoun; Gupta, Nilesh; Hartmann, Arndt; Leroy, Xavier; Bashir, Samir Al; Yilmaz, Asli; Hes, Ondřej

2018-04-01

To further characterise biphasic squamoid renal cell carcinoma (RCC), a recently proposed variant of papillary RCC. We identified 28 tumours from multiple institutions. They typically showed two cell populations-larger cells with eosinophilic cytoplasm and higher-grade nuclei, surrounded by smaller, amphophilic cells with scanty cytoplasm. The dual morphology was variable (median 72.5% of tumour, range 5-100%); emperipolesis was found in all cases. The male/female ratio was 2:1, and the median age was 55 years (range 39-86 years). The median tumour size was 20 mm (range 9-65 mm). Pathological stage pT1a was found in 21 cases, pT1b in three, and pT3a and pT3b in one each (two not available). Multifocality was found in 32%: multifocal biphasic RCC in one case, biphasic + papillary RCC in two cases, biphasic + clear cell RCC in three cases, biphasic + low-grade urothelial carcinoma of the renal pelvis in one case, and biphasic + Birt-Hogg-Dubé syndrome in one case. Positive immunostains included: PAX8, cytokeratin (CK) 7, α-methylacyl-CoA racemase, epithelial membrane antigen, and vimentin. Cyclin D1 was expressed only in the larger cells. The Ki67 index was higher in the larger cells (median 5% versus ≤1%). Negative stains included: carbonic anhydrase 9, CD117, GATA-3, WT1, CK5/6, and CK20; CD10 and 34βE12 were variably expressed. Gains of chromosomes 7 and 17 were found in two evaluated cases. Follow-up was available for 23 patients (median 24 months, range 1-244 months): 19 were alive without disease, one was alive with recurrence, and one had died of disease (two had died of other causes). Biphasic papillary RCC is a rare variant of papillary RCC, and is often multifocal. © 2017 John Wiley & Sons Ltd.

CO2 Absorption by Biphasic Solvents: Comparison with Lower Phase Alone

International Nuclear Information System (INIS)

Xu, Zhicheng; Wang, Shujuan; Qi, Guojie; Liu, Jinzhao; Zhao, Bo; Chen, Changhe

2014-01-01

The mixtures of 2 M 1,4-butanediamine (BDA) and 4 M 2-(diethylamino)-ethanol (DEEA) have been found to be promising biphasic solvents. This work identifies the composition of the lower phase using a DX-120 Ion Chromatograph (IC) and a Metrohm 809 Titrando auto titrator. The cyclic capacities, cyclic loadings and reaction products of the biphasic solvent are compared with those of the aqueous solution with the same amine concentration as the lower phase of the biphasic solvent at the rich loading ((2B4D) L ) using a fast screening facility and a JNM ECA-600 Nuclear Magnetic Resonance spectrometer (NMR). Their absorption rates at different loadings are also investigated using a Wetted Wall Column (WWC). The results show that the cyclic capacity and cyclic loading of (2B4D) L are almost the same as those of 2B4D. The absorption rate of (2B4D) L is higher than 2B4D at all the 3 tested loadings, except for the fresh solutions at CO 2 pressure lower than 10 kPa. NMR results show that the reaction products of (2B4D) L had more BDA bi-carbamate, less BDA and less BDA carbamate than 2B4D. The CO 2 reaction products of (2B4D) L had twice as much carbonate/bicarbonate as with 2B4D and less BDA carbamate. (authors)

Chiral separation of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography with biphasic recognition

Science.gov (United States)

Tong, Shengqiang

2010-01-01

This work concentrates on a novel chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether-water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Various parameters involved in the chiral separation were investigated, namely the types of the chiral selector (CS); the concentration of each chiral selector; pH of the mobile phase; and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for each chiral selector. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both lipophilic and hydrophilic chiral selectors. PMID:20303497

Characterization and in vitro evaluation of biphasic α-tricalcium phosphate/β-tricalcium phosphate cement

Energy Technology Data Exchange (ETDEWEB)

Arahira, Takaaki; Maruta, Michito, E-mail: maruta@college.fdcnet.ac.jp; Matsuya, Shigeki

2017-05-01

Biphasic calcium phosphate consisting of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) is an excellent bone substitute with controllable bioresorbability. Fabrication of biphasic calcium phosphate with self-setting ability is expected to enhance its potential application as bone substitute. In this study, mixtures of α-TCP and β-TCP with various compositions were prepared through α-β phase transition of α-TCP powder at 1000 °C for various periods. These powders were mixed with 0.25 M Na{sub 2}HPO{sub 4} at a P/L ratio of 2, and then hardened at 37 °C at 100% RH for up to 24 h. Material properties of biphasic HA/β-TCP cement with different α-TCP/β-TCP composition were characterized. These cements were also evaluated with respect to cell response in vitro using MC3T3-E1 cell lines. In conclusion, mechanical and biological properties of HA/β-TCP cement could be controlled by changing the heat treatment time of α-TCP powder at 1000 °C. In vitro results indicated that cell proliferation and ALP activity increased with increase β-TCP content. - Highlights: • We could fabricate biphasic HA/β-TCP cements using heat treated α-TCP powder. • It is easy to control the ratio of α-TCP to β-TCP changing the heat treatment time up to 48 h. • Both cell number and ALP activity increased with increase in β-TCP content. • In vitro results showed that β-TCP has superior cell affinity to HA.

A Simplified Whole-Organ CT Perfusion Technique with Biphasic Acquisition: Preliminary Investigation of Accuracy and Protocol Feasibility in Kidneys.

Science.gov (United States)

Yuan, XiaoDong; Zhang, Jing; Quan, ChangBin; Tian, Yuan; Li, Hong; Ao, GuoKun

2016-04-01

To determine the feasibility and accuracy of a protocol for calculating whole-organ renal perfusion (renal blood flow [RBF]) and regional perfusion on the basis of biphasic computed tomography (CT), with concurrent dynamic contrast material-enhanced (DCE) CT perfusion serving as the reference standard. This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Biphasic CT of the kidneys, including precontrast and arterial phase imaging, was integrated with a first-pass dynamic volume CT protocol and performed and analyzed in 23 patients suspected of having renal artery stenosis. The perfusion value derived from biphasic CT was calculated as CT number enhancement divided by the area under the arterial input function and compared with the DCE CT perfusion data by using the paired t test, correlation analysis, and Bland-Altman plots. Correlation analysis was made between the RBF and the extent of renal artery stenosis. All postprocessing was independently performed by two observers and then averaged as the final result. Mean ± standard deviation biphasic and DCE CT perfusion data for RBF were 425.62 mL/min ± 124.74 and 419.81 mL/min ± 121.13, respectively (P = .53), and for regional perfusion they were 271.15 mL/min per 100 mL ± 82.21 and 266.33 mL/min per 100 mL ± 74.40, respectively (P = .31). Good correlation and agreement were shown between biphasic and DCE CT perfusion for RBF (r = 0.93; ±10% variation from mean perfusion data [P < .001]) and for regional perfusion (r = 0.90; ±13% variation from mean perfusion data [P < .001]). The extent of renal artery stenosis was negatively correlated with RBF with biphasic CT perfusion (r = -0.81, P = .012). Biphasic CT perfusion is clinically feasible and provides perfusion data comparable to DCE CT perfusion data at both global and regional levels in the kidney. Online supplemental material is available for this article.

Predictive feedback can account for biphasic responses in the lateral geniculate nucleus.

Directory of Open Access Journals (Sweden)

Janneke F M Jehee

2009-05-01

Full Text Available Biphasic neural response properties, where the optimal stimulus for driving a neural response changes from one stimulus pattern to the opposite stimulus pattern over short periods of time, have been described in several visual areas, including lateral geniculate nucleus (LGN, primary visual cortex (V1, and middle temporal area (MT. We describe a hierarchical model of predictive coding and simulations that capture these temporal variations in neuronal response properties. We focus on the LGN-V1 circuit and find that after training on natural images the model exhibits the brain's LGN-V1 connectivity structure, in which the structure of V1 receptive fields is linked to the spatial alignment and properties of center-surround cells in the LGN. In addition, the spatio-temporal response profile of LGN model neurons is biphasic in structure, resembling the biphasic response structure of neurons in cat LGN. Moreover, the model displays a specific pattern of influence of feedback, where LGN receptive fields that are aligned over a simple cell receptive field zone of the same polarity decrease their responses while neurons of opposite polarity increase their responses with feedback. This phase-reversed pattern of influence was recently observed in neurophysiology. These results corroborate the idea that predictive feedback is a general coding strategy in the brain.

A simulation study of the reaction of human heart to biphasic electrical shocks

Directory of Open Access Journals (Sweden)

Seemann Gunnar

2004-06-01

Full Text Available Abstract Background This article presents a study, which examines the effects of biphasic electrical shocks on human ventricular tissue. The effects of this type of shock are not yet fully understood. Animal experiments showed the superiority of biphasic shocks over monophasic ones in defibrillation. A mathematical computer simulation can increase the knowledge of human heart behavior. Methods The research presented in this article was done with different models representing a three-dimensional wedge of ventricular myocardium. The electrophysiology was described with Priebe-Beuckelmann model. The realistic fiber twist, which is specific to human myocardium was included. Planar electrodes were placed at the ends of the longest side of the virtual cardiac wedge, in a bath medium. They were sources of electrical shocks, which varied in magnitude from 0.1 to 5 V. In a second arrangement ring electrodes were placed directly on myocardium for getting a better view on secondary electrical sources. The electrical reaction of the tissue was generated with a bidomain model. Results The reaction of the tissue to the electrical shock was specific to the initial imposed characteristics. Depolarization appeared in the first 5 ms in different locations. A further study of the cardiac tissue behavior revealed, which features influence the response of the considered muscle. It was shown that the time needed by the tissue to be totally depolarized is much shorter when a biphasic shock is applied. Each simulation ended only after complete repolarization was achieved. This created the possibility of gathering information from all states corresponding to one cycle of the cardiac rhythm. Conclusions The differences between the reaction of the homogeneous tissue and a tissue, which contains cleavage planes, reveals important aspects of superiority of biphasic pulses. ...

Learning new meanings for known words: Biphasic effects of prior knowledge

Science.gov (United States)

Fang, Xiaoping; Perfetti, Charles; Stafura, Joseph

2017-01-01

In acquiring word meanings, learners are often confronted by a single word form that is mapped to two or more meanings. For example, long after how to roller-“skate”, one may learn that “skate” is also a kind of fish. Such learning of new meanings for familiar words involves two potentially contrasting processes, relative to new form-new meaning learning: 1) Form-based familiarity may facilitate learning a new meaning, and 2) meaning-based interference may inhibit learning a new meaning. We examined these two processes by having native English speakers learn new, unrelated meanings for familiar (high frequency) and less familiar (low frequency) English words, as well as for unfamiliar (novel or pseudo-) words. Tracking learning with cued-recall tasks at several points during learning revealed a biphasic pattern: higher learning rates and greater learning efficiency for familiar words relative to novel words early in learning and a reversal of this pattern later in learning. Following learning, interference from original meanings for familiar words was detected in a semantic relatedness judgment task. Additionally, lexical access to familiar words with new meanings became faster compared to their exposure controls, but no such effect occurred for less familiar words. Overall, the results suggest a biphasic pattern of facilitating and interfering processes: Familiar word forms facilitate learning earlier, while interference from original meanings becomes more influential later. This biphasic pattern reflects the co-activation of new and old meanings during learning, a process that may play a role in lexicalization of new meanings. PMID:29399593

A case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion.

Science.gov (United States)

Hazama, Kyoko; Shiihara, Takashi; Tsukagoshi, Hiroyuki; Hasegawa, Shunji; Dowa, Yuri; Watanabe, Mio

2017-10-01

Mumps is a common childhood viral disease characterized by fever and swelling of the parotid gland. The prognosis is generally good, although some complications, such as encephalitis (0.1%), exist. Acute encephalopathy with biphasic seizures and late reduced diffusion is the most common type of acute encephalopathy. However, this type of encephalopathy has not been reported in association with mumps infection. A previously healthy 3-year-old Japanese boy had a brief convulsion after fever for 3days, and then had conscious disturbance and parotitis. After several days, he had a second brief convulsion and was admitted. Increased serum amylase levels and presence of anti-mumps immunoglobulin M antibody confirmed mumps parotitis. The patient had another brief seizure later the day of admission. He did not have status or cluster seizures, although the biphasic nature of his seizures, conscious disturbance between the seizures, no pleocytosis in cerebrospinal fluid, and brain magnetic resonance images were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion. In Japan, the mumps vaccine is not administered as a part of routine immunizations. It thus has low coverage (30-40%), and as a result, mumps infections are still common. However, this is the first case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion. This case may be representative of only a minority of patients with mumps-associated central nervous system involvement. Nevertheless, this diagnostic possibility may be considered. In order to prevent mumps-related complications, routine mumps vaccination might be warranted. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

H4K20me0 marks post-replicative chromatin and recruits the TONSL–MMS22L DNA repair complex

DEFF Research Database (Denmark)

Saredi, Giulia; Huang, Hongda; Hammond, Colin M

2016-01-01

After DNA replication, chromosomal processes including DNA repair and transcription take place in the context of sister chromatids. While cell cycle regulation can guide these processes globally, mechanisms to distinguish pre- and post-replicative states locally remain unknown. Here we reveal...

A New Biphasic Dicalcium Silicate Bone Cement Implant

Directory of Open Access Journals (Sweden)

Fausto Zuleta

2017-07-01

Full Text Available This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23 obtained higher bone-to-implant contact (BIC percentage values (better quality, closer contact in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic. The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

Fluoxetine Is a Potent Inhibitor of Coxsackievirus Replication

OpenAIRE

Zuo, Jun; Quinn, Kevin K.; Kye, Steve; Cooper, Paige; Damoiseaux, Robert; Krogstad, Paul

2012-01-01

No antiviral drugs currently exist for the treatment of enterovirus infections, which are often severe and potentially life threatening. Molecular screening of small molecule libraries identified fluoxetine, a selective serotonin reuptake inhibitor, as a potent inhibitor of coxsackievirus replication. Fluoxetine did not interfere with either viral entry or translation of the viral genome. Instead, fluoxetine and its metabolite norfluoxetine markedly reduced the synthesis of viral RNA and prot...

Non-conventional solvents in liquid phase microextraction and aqueous biphasic systems.

Science.gov (United States)

An, Jiwoo; Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L

2017-06-02

The development of rapid, convenient, and high throughput sample preparation approaches such as liquid phase microextraction techniques have been continuously developed over the last decade. More recently, significant attention has been given to the replacement of conventional organic solvents used in liquid phase microextraction techniques in order to reduce toxic waste and to improve selectivity and/or extraction efficiency. With these objectives, non-conventional solvents have been explored in liquid phase microextraction and aqueous biphasic systems. The utilized non-conventional solvents include ionic liquids, magnetic ionic liquids, and deep eutectic solvents. They have been widely used as extraction solvents or additives in various liquid phase microextraction modes including dispersive liquid-liquid microextraction, single-drop microextraction, hollow fiber-liquid phase microextraction, as well as in aqueous biphasic systems. This review provides an overview into the use of non-conventional solvents in these microextraction techniques in the past 5 years (2012-2016). Analytical applications of the techniques are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

A prospective, randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in out-of-hospital cardiac arrest

NARCIS (Netherlands)

van Alem, Anouk P.; Chapman, Fred W.; Lank, Paula; Hart, Augustinus A. M.; Koster, Rudolph W.

2003-01-01

Background: Evidence suggests that biphasic waveforms are more effective than monophasic waveforms for defibrillation in out-of-hospital cardiac arrest (OHCA), yet their performance has only been compared in un-blinded studies. Methods and results: We compared the success of biphasic truncated

Comb polymer architecture and particle size effects on the behavior of biphasic nanoparticle inks for direct-write assembly

Science.gov (United States)

Yoshikawa, Jun

Biphasic nanoparticle mixtures composed of attractive and repulsive colloidal species enable the direct-write assembly of 3D structures with much finer features than those produced by pure colloidal gels. These mixtures rely on the use of comb polymer dispersants to render one particle population stable, while the other population is attractive. In this thesis, we systematically investigate the effects of comb polymer architecture and particle size ratio on the behavior of biphasic nanoparticle inks with the overarching aim of further advancing the direct-write assembly of 3D colloidal structures. We first investigated the effects of both pure polyelectrolytes, poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA), and comb polymer dispersants composed of a PMAA backbone with methoxy-poly(ethylene oxide) (mPEO) teeth of varying molecular weights on the stability of barium titanate (BaTiO 3) suspensions. While each dispersant imparts stability to BaTiO 3 nanoparticles at low ionic strength (teeth (MWteeth = 2000) provides stability at higher ionic strengths over a broad range of particle sizes and counterion valencies. These results provide guidelines for tailoring the molecular architecture and functionality of comb polymer dispersants for optimal stabilization of the repulsive particle population within the biphasic inks. Next, particle size effects on the rheological properties of biphasic nanoparticle suspensions are studied. Shear elastic modulus, shear yield stress, and compressive yield stress are measured for mixtures of varying total volume fraction, attractive-to-repulsive volume fraction, and particle size ratio between attractive and repulsive species. Our observations indicate that the repulsive particles hinder the formation of the attractive gel network. The time required for shear elastic modulus to approach a steady-state value increases with the fraction of repulsive species. Furthermore, this behavior becomes more significant with increasing

Invariance of the magnetic behavior and AMI in ferromagnetic biphase films with distinct non-magnetic metallic spacers

Energy Technology Data Exchange (ETDEWEB)

Silva, E.F. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Gamino, M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Andrade, A.M.H. de [Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Vázquez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Correa, M.A. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Bohn, F., E-mail: felipebohn@fisica.ufrn.br [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil)

2017-02-01

We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices.

Anti-prelog reduction of prochiral carbonyl compounds by Oenococcus oeni in a biphasic system.

Science.gov (United States)

Hu, Jian; Xu, Yan

2006-07-01

An aqueous-organic biphasic system was established and used with whole cells of Oenococcus oeni to reduce 2-octanone to (R)-2-octanol. The conversion reached 99% when the Tris/borate buffer was increased from 50 mM to 300 mM in the aqueous phase. In addition, the conversion increased as the log P value of the organic solvent changed from 0.5 to 6.6. Under optimized conditions, the conversion of (R)-2-octanol reached 99% from 0.5 M 2-octanone with an optical purity of 99% e.e. The biphasic system allows the anti-Prelog reduction of aliphatic and aromatic ketones to furnish (R)-configurated alcohols in high optical purity as well.

Adeno-associated virus type 2 enhances goose parvovirus replication in embryonated goose eggs

International Nuclear Information System (INIS)

Malkinson, Mertyn; Winocour, Ernest

2005-01-01

The autonomous goose parvovirus (GPV) and the human helper-dependent adeno-associated virus type 2 (AAV2) share a high degree of homology. To determine if this evolutionary relationship has a biological impact, we studied viral replication in human 293 cells and in embryonated goose eggs coinfected with both viruses. Similar experiments were performed with the minute virus of mice (MVM), an autonomous murine parvovirus with less homology to AAV2. In human 293 cells, both GPV and MVM augmented AAV2 replication. In contrast, AAV2 markedly enhanced GPV replication in embryonated goose eggs under conditions where a similar effect was not observed with MVM. AAV2 did not replicate in embryonated goose eggs and AAV2 inactivated by UV-irradiation also enhanced GPV replication. To our knowledge, this is the first report that a human helper-dependent member of the Parvoviridae can provide helper activity for an autonomous parvovirus in a natural host

Temperature dependence of microwave absorption phenomena in single and biphase soft magnetic microwires

Czech Academy of Sciences Publication Activity Database

El Kammouni, R.; Vázquez, M.; Lezama, L.; Kurlyandskaya, G.; Kraus, Luděk

2014-01-01

Roč. 368, Nov (2014), 126-132 ISSN 0304-8853 Institutional support: RVO:68378271 Keywords : magnetic microwire * ferromagnetic resonance * microwave absorption * biphase magnetic system Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.970, year: 2014

Occurrence of amylose-lipid complexes in teff and maize starch biphasic pastes

CSIR Research Space (South Africa)

Wokadala, OC

2012-09-01

Full Text Available The occurrence of amylose–lipid complexes was determined in maize and teff starch biphasic pastes i.e. peak viscosity pastes at short and prolonged pasting times. Maize and teff starches were pasted for 11.5 and 130 min with or without added stearic...

Acute exercise induces biphasic increase in respiratory mRNA in skeletal muscle

International Nuclear Information System (INIS)

Ikeda, Shin-ichi; Kizaki, Takako; Haga, Shukoh; Ohno, Hideki; Takemasa, Tohru

2008-01-01

Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) promotes the expression of oxidative enzymes in skeletal muscle. We hypothesized that activation of the p38 MAPK (mitogen-activated protein kinase) in response to exercise was associated with exercise-induced PGC-1α and respiratory enzymes expression and aimed to demonstrate this under the physiological level. We subjected mice to a single bout of treadmill running and found that the exercise induced a biphasic increase in the expression of respiratory enzymes mRNA. The second phase of the increase was accompanied by an increase in PGC-1α protein, but the other was not. Administration of SB203580 (SB), an inhibitor of p38 MAPK, suppressed the increase in PGC-1α expression and respiratory enzymes mRNA in both phases. These data suggest that p38 MAPK is associated with the exercise-induced expression of PGC-1α and biphasic increase in respiratory enzyme mRNAs in mouse skeletal muscle under physiological conditions

Distribution of DNA replication proteins in Drosophila cells

Science.gov (United States)

Easwaran, Hariharan P; Leonhardt, Heinrich; Cardoso, M Cristina

2007-01-01

Background DNA replication in higher eukaryotic cells is organized in discrete subnuclear sites called replication foci (RF). During the S phase, most replication proteins assemble at the RF by interacting with PCNA via a PCNA binding domain (PBD). This has been shown to occur for many mammalian replication proteins, but it is not known whether this mechanism is conserved in evolution. Results Fluorescent fusions of mammalian replication proteins, Dnmt1, HsDNA Lig I and HsPCNA were analyzed for their ability to target to RF in Drosophila cells. Except for HsPCNA, none of the other proteins and their deletions showed any accumulation at RF in Drosophila cells. We hypothesized that in Drosophila cells there might be some other peptide sequence responsible for targeting proteins to RF. To test this, we identified the DmDNA Lig I and compared the protein sequence with HsDNA Lig I. The two orthologs shared the PBD suggesting a functionally conserved role for this domain in the Drosophila counterpart. A series of deletions of DmDNA Lig I were analyzed for their ability to accumulate at RF in Drosophila and mammalian cells. Surprisingly, no accumulation at RF was observed in Drosophila cells, while in mammalian cells DmDNA Lig I accumulated at RF via its PBD. Further, GFP fusions with the PBD domains from Dnmt1, HsDNA Lig I and DmDNA Lig I, were able to target to RF only in mammalian cells but not in Drosophila cells. Conclusion We show that S phase in Drosophila cells is characterized by formation of RF marked by PCNA like in mammalian cells. However, other than PCNA none of the replication proteins and their deletions tested here showed accumulation at RF in Drosophila cells while the same proteins and deletions are capable of accumulating at RF in mammalian cells. We hypothesize that unlike mammalian cells, in Drosophila cells, replication proteins do not form long-lasting interactions with the replication machinery, and rather perform their functions via very

A model for transmission of the H3K27me3 epigenetic mark

DEFF Research Database (Denmark)

Hansen, Klaus H; Bracken, Adrian P; Pasini, Diego

2008-01-01

Organization of chromatin by epigenetic mechanisms is essential for establishing and maintaining cellular identity in developing and adult organisms. A key question that remains unresolved about this process is how epigenetic marks are transmitted to the next cell generation during cell division...... during incorporation of newly synthesized histones. This mechanism ensures maintenance of the H3K27me3 epigenetic mark in proliferating cells, not only during DNA replication when histones synthesized de novo are incorporated, but also outside S phase, thereby preserving chromatin structure...

A phenomenological model of the electrically stimulated auditory nerve fiber: temporal and biphasic response properties

Directory of Open Access Journals (Sweden)

Colin eHorne

2016-02-01

Full Text Available We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs. The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability under both monophasic and cathodic-anodic biphasic stimulation, without changing the model’s parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions.Our work extends the stochastic leaky integrate and fire (SLIF neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model.

NotaMark industrial laser marking system: a new security marking technology

Science.gov (United States)

Moreau, Vincent G.

2004-06-01

Up until now, the only variable alphanumeric data which could be added to banknotes was the number, applied by means of impact typographical numbering boxes. As an additional process or an alternative to this mechanical method, a non-contact laser marking process can be used offering high quality and greater levels of flexibility. For this purpose KBA-GIORI propose an exclusive laser marking solution called NotaMark. The laser marking process NotaMark is the ideal solution for applying variable data and personalizing banknotes (or any other security documents) with a very high resolution, for extremely large production volumes. A completely integrated solution has been developed comprised of laser light sources, marking head units, and covers and extraction systems. NotaMark allows the marking of variable data by removing locally and selectively, specific printed materials leaving the substrate itself untouched. A wide range of materials has already been tested extensively. NotaMark is a new security feature which is easy to identify and difficult to counterfeit, and which complies with the standard mechanical and chemical resistance tests in the security printing industry as well as with other major soiling tests. The laser marking process opens up a whole new range of design possibilities and can be used to create a primary security feature such as numbering, or to enhance the value of existing features.

Mirror-mark tests performed on jackdaws reveal potential methodological problems in the use of stickers in avian mark-test studies.

Directory of Open Access Journals (Sweden)

Manuel Soler

Full Text Available Some animals are capable of recognizing themselves in a mirror, which is considered to be demonstrated by passing the mark test. Mirror self-recognition capacity has been found in just a few mammals having very large brains and only in one bird, the magpie (Pica pica. The results obtained in magpies have enormous biological and cognitive implications because the fact that magpies were able to pass the mark test meant that this species is at the same cognitive level with great apes, that mirror self-recognition has evolved independently in the magpie and great apes (which diverged 300 million years ago, and that the neocortex (which is not present in the bird's brains is not a prerequisite for mirror self-recognition as previously believed. Here, we have replicated the experimental design used on magpies to determine whether jackdaws (Corvus monedula are also capable of mirror self-recognition by passing the mark test. We found that our nine jackdaws showed a very high interest towards the mirror and exhibited self-contingent behavior as soon as mirrors were introduced. However, jackdaws were not able to pass the mark test: both sticker-directed actions and sticker removal were performed with a similar frequency in both the cardboard (control and the mirror conditions. We conclude that our jackdaws' behaviour raises non-trivial questions about the methodology used in the avian mark test. Our study suggests that the use of self-adhesive stickers on sensitive throat feathers may open the way to artefactual results because birds might perceive the stickers tactilely.

The Phosphodiesterase 4 Inhibitor Prevents Antigen-induced Biphasic Nasal Obstruction in Brown Norway Rats

Directory of Open Access Journals (Sweden)

Hirokazu Kawasaki

2005-01-01

Conclusions: The present study provides a simple model of allergic biphasic nasal obstruction in BN rats, and also suggests that the PDE4 inhibitor may alleviate nasal obstruction in patients with allergic rhinitis.

Efficacy and safety of biphasic insulin aspart and biphasic insulin lispro mix in patients with type 2 diabetes: A review of the literature

Directory of Open Access Journals (Sweden)

Ajay Kumar

2016-01-01

Full Text Available Type 2 diabetes (T2D represents an escalating burden worldwide, particularly in China and India. Compared with Caucasians, Asian people with diabetes have lower body mass index, increased visceral adiposity, and postprandial glucose (PPG/insulin resistance. Since postprandial hyperglycemia contributes significantly to total glycemic burden and is associated with heightened cardiovascular risk, targeting PPG early in T2D is paramount. Premixed insulin regimens are widely used in Asia due to their convenience and effectiveness. Data from randomized controlled trials and observational studies comparing efficacy and safety of biphasic insulin aspart 30 (BIAsp 30 with biphasic insulin lispro mix (LM 25/50 and versus other insulin therapies or oral antidiabetic drugs (OADs in T2D demonstrated that BIAsp 30 and LM 25/50 were associated with similar or greater improvements in glycemic control versus comparator regimens, such as basal–bolus insulin, in insulin-naÏve, and prior insulin users. Studies directly comparing BIAsp 30 and LM 25 provided conflicting glycemic control results. Safety data generally showed increased hypoglycemia and weight gain with premixed insulins versus basal–bolus insulin or OADs. However, large observational trials documented improvements in glycated hemoglobin, PPG, and hypoglycemia with BIAsp 30 in multi-ethnic patient populations. In summary, this literature review demonstrates that premixed insulin regimens are an appropriate and effective treatment choice in T2D.

Biphasic growth of orbital volume in Chinese children.

Science.gov (United States)

Wei, Nan; Bi, Hua; Zhang, Bin; Li, Xue; Sun, Fengyuan; Qian, Xuehan

2017-09-01

The aim of this study was to map out the developmental curve of the orbital volume of Chinese children aged 1-15 years. CT scanning was performed on 109 children and the orbital volume, interlateral orbital rim distance (IORD), and extent of exophthalmos were measured on the CT images and plotted against age. The development of the orbit structure followed a biphasic pattern. The first growth phase was before 3 years and the second growth phase was between 7 years and 12 years of age. The growth speed in the first phase was about 3 times that of the second one (first vs second phase: 2.28 cm 3 /year vs 0.67 cm 3 /year for orbital volume, 5.01 mm/year vs 1.57 mm/year for IORD, 1.29 mm/year vs 0.42 mm/year for the exophthalmos). During development, there was no significant difference between the left and right orbits. There was no significant difference between boys and girls before 12 years of age. However, after 12 years of age, boys had significantly larger orbital volumes (22.16±2.28 cm 3 /year vs 18.57±1.16 cm 3 /year, pChinese children, the development of orbital volume follows a biphasic pattern and a sex difference becomes significant after the age of 12 years. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Comparison of the lysis-centrifugation and agitated biphasic blood culture systems for detection of fungemia.

Science.gov (United States)

Murray, P R

1991-01-01

Although the detection of fungemia has been improved by the use of vented or biphasic blood culture bottles, the best recovery and earliest detection have been reported in the Isolator lysis-centrifugation system. It was recently demonstrated that improved detection of both bacteria and fungi was accomplished by mechanically agitating blood culture bottles for the first 24 h of incubation. In this study the detection of fungemia by use of the Isolator system was compared with that of an agitated biphasic system. A total of 182 fungi were isolated from blood specimens inoculated into both culture systems. No difference in the overall recovery of fungi or individual species of yeasts was observed between the two systems. However, all seven isolates of Histoplasma capsulatum were recovered in the Isolator system only. The time required to detect fungemia with each of the two systems was also compared. No statistically significant difference was observed. From the data collected during this 18-month study, it can be concluded that the overall recovery and time of detection of yeasts are equivalent in the lysis-centrifugation system and the agitated biphasic blood culture system. The lysis-centrifugation system is still superior for the detection of filamentous fungi such as H. capsulatum. PMID:1993772

RF magnetron-sputtered coatings deposited from biphasic calcium phosphate targets for biomedical implant applications

Directory of Open Access Journals (Sweden)

K.A. Prosolov

2017-09-01

Full Text Available Bioactive calcium phosphate coatings were deposited by radio-frequency magnetron sputtering from biphasic targets of hydroxyapatite and tricalcium phosphate, sintered at different mass % ratios. According to Raman scattering and X-ray diffraction data, the deposited hydroxyapatite coatings have a disordered structure. High-temperature treatment of the coatings in air leads to a transformation of the quasi-amorphous structure into a crystalline one. A correlation has been observed between the increase in the Ca content in the coatings and a subsequent decrease in Ca in the biphasic targets after a series of deposition processes. It was proposed that the addition of tricalcium phosphate to the targets would led to a finer coating's surface topography with the average size of 78 nm for the structural elements.

Biphasic single-reactor process for dehydration of xylose and hydrogenation of produced furfural

NARCIS (Netherlands)

Ordomskiy, V.; Schouten, J.C.; Schaaf, van der J.; Nijhuis, T.A.

2013-01-01

The processes of xylose dehydration and the consecutive furfural hydrogenation have been combined in a single biphasic reactor. The dehydration was studied over Amberlyst-15 and the hydrogenation over a hydrophobic Ru/C catalyst. 1-Butanol, 2-methyltetrahydrofuran and cyclohexane were used as

Production of Phytotoxic Metabolite Using Biphasic Fermentation System from Strain C1136 of Lasiodiplodia pseudotheobromae, a Potential Bioherbicidal Agent

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Charles Oluwaseun ADETUNJI

2017-09-01

Full Text Available Formulation of effective and environmental friendly bioherbicides depends on the type of fermentation medium used for the production of phytotoxic metabolites. The effect of biomass, colony forming unit and the phytotoxic metabolite produced from the biphasic fermentation was carried out, while the phytotoxic metabolite was tested in vivo and in-vitro on Echinochola crus-galli and dicotyledonous Chromolaena odorata. The mutant strain of Lasiodiplodia pseudotheobromae C1136 (Lp90 produced the highest amount of conidia and the largest necrotic area on the two tested weeds when compared to its wild strain in the different biphasic media combinations. The study revealed that the biphasic system containing PDB + rice produced the highest bioherbicidal activities. Therefore, the phytotoxic metabolites from strain C1136 are suggested for large scale production of bioherbicides for the management of weeds in conventional farming to improve yield and enhance food security.

Species dependent radiotracer study of Cr(VI) and Cr(III) using an aqueous biphasic system

Energy Technology Data Exchange (ETDEWEB)

Roy, K.; Lahiri, S. [Chemical Sciences Div., Saha Inst. of Nuclear Physics, Kolkata (India)

2008-07-01

The speciation study of Cr(III) and Cr(VI) was carried out using a polyethylene glycol (PEG) based aqueous biphasic extraction system (ABS). Neutron activated Cr(III) and Cr(VI) salts were assayed in a HPGe detector before and after employing aqueous biphasic extraction. Different salts of various salting out abilities were taken as the salt rich phase. The best condition for extraction of Cr(VI) and the maximum differential attitude of ABS to Cr(VI) and Cr(III) was observed when 2 M Na{sub 2}SO{sub 4} and PEG 4000 (50% w/w) solutions were used. Cr(III) can also be extracted by the PEG with prior complexation with diphenylthiocarbazone (dithizone). The chromium dithizonate complex is quantitatively extracted by the PEG rich phase. (orig.)

Inhibition of Hepatitis B virus cccDNA replication by siRNA

International Nuclear Information System (INIS)

Li Guiqiu; Gu Hongxi; Li Di; Xu Weizhen

2007-01-01

The development of an effective therapy for Hepatitis B virus (HBV) infection is still a challenge. Progress in RNA interference (RNAi) has shed slight on developing a new anti-HBV strategy. Here, we present a series of experiments showing a significant reduction in HBV transcripts and replication intermediates in HepG2.2.15 cells by vector-based siRNA targeted nuclear localization signal (NLS) region. More importantly, we showed that siRNA1 markedly inhibited HBV covalently closed circular DNA (cccDNA) replication. Our results indicated that HBV NLS may serve as a novel RNAi target to combat HBV infection, which can enhance anti-HBV efficacy and overcome the drawbacks of current therapies

Evaluation of parallel milliliter-scale stirred-tank bioreactors for the study of biphasic whole-cell biocatalysis with ionic liquids.

Science.gov (United States)

Dennewald, Danielle; Hortsch, Ralf; Weuster-Botz, Dirk

2012-01-01

As clear structure-activity relationships are still rare for ionic liquids, preliminary experiments are necessary for the process development of biphasic whole-cell processes involving these solvents. To reduce the time investment and the material costs, the process development of such biphasic reaction systems would profit from a small-scale high-throughput platform. Exemplarily, the reduction of 2-octanone to (R)-2-octanol by a recombinant Escherichia coli in a biphasic ionic liquid/water system was studied in a miniaturized stirred-tank bioreactor system allowing the parallel operation of up to 48 reactors at the mL-scale. The results were compared to those obtained in a 20-fold larger stirred-tank reactor. The maximum local energy dissipation was evaluated at the larger scale and compared to the data available for the small-scale reactors, to verify if similar mass transfer could be obtained at both scales. Thereafter, the reaction kinetics and final conversions reached in different reactions setups were analysed. The results were in good agreement between both scales for varying ionic liquids and for ionic liquid volume fractions up to 40%. The parallel bioreactor system can thus be used for the process development of the majority of biphasic reaction systems involving ionic liquids, reducing the time and resource investment during the process development of this type of applications. Copyright © 2011. Published by Elsevier B.V.

Intervertebral Disc Tissue Engineering with Natural Extracellular Matrix-Derived Biphasic Composite Scaffolds.

Directory of Open Access Journals (Sweden)

Baoshan Xu

Full Text Available Tissue engineering has provided an alternative therapeutic possibility for degenerative disc diseases. However, we lack an ideal scaffold for IVD tissue engineering. The goal of this study is to fabricate a novel biomimetic biphasic scaffold for IVD tissue engineering and evaluate the feasibility of developing tissue-engineered IVD in vitro and in vivo. In present study we developed a novel integrated biphasic IVD scaffold using a simple freeze-drying and cross-linking technique of pig bone matrix gelatin (BMG for the outer annulus fibrosus (AF phase and pig acellular cartilage ECM (ACECM for the inner nucleus pulposus (NP phase. Histology and SEM results indicated no residual cells remaining in the scaffold that featured an interconnected porous microstructure (pore size of AF and NP phase 401.4 ± 13.1 μm and 231.6 ± 57.2 μm, respectively. PKH26-labeled AF and NP cells were seeded into the scaffold and cultured in vitro. SEM confirmed that seeded cells could anchor onto the scaffold. Live/dead staining showed that live cells (green fluorescence were distributed in the scaffold, with no dead cells (red fluorescence being found. The cell-scaffold constructs were implanted subcutaneously into nude mice and cultured for 6 weeks in vivo. IVD-like tissue formed in nude mice as confirmed by histology. Cells in hybrid constructs originated from PKH26-labeled cells, as confirmed by in vivo fluorescence imaging system. In conclusion, the study demonstrates the feasibility of developing a tissue-engineered IVD in vivo with a BMG- and ACECM-derived integrated AF-NP biphasic scaffold. As well, PKH26 fluorescent labeling with in vivo fluorescent imaging can be used to track cells and analyse cell--scaffold constructs in vivo.

Aqueous biphasic extraction of uranium and thorium from contaminated soils. Final report

International Nuclear Information System (INIS)

Chaiko, D.J.; Gartelmann, J.; Henriksen, J.L.; Krause, T.R.; Deepak; Vojta, Y.; Thuillet, E.; Mertz, C.J.

1995-07-01

The aqueous biphasic extraction (ABE) process for soil decontamination involves the selective partitioning of solutes and fine particulates between two immiscible aqueous phases. The biphase system is generated by the appropriate combination of a water-soluble polymer (e.g., polyethlene glycol) with an inorganic salt (e.g., sodium carbonate). Selective partitioning results in 99 to 99.5% of the soil being recovered in the cleaned-soil fraction, while only 0.5 to 1% is recovered in the contaminant concentrate. The ABE process is best suited to the recovery of ultrafine, refractory material from the silt and clay fractions of soils. During continuous countercurrent extraction tests with soil samples from the Fernald Environmental Management Project site (Fernald, OH), particulate thorium was extracted and concentrated between 6- and 16-fold, while the uranium concentration was reduced from about 500 mg/kg to about 77 mg/kg. Carbonate leaching alone was able to reduce the uranium concentration only to 146 mg/kg. Preliminary estimates for treatment costs are approximately $160 per ton of dry soil. A detailed flowsheet of the ABE process is provided

Injectable TEMPO-oxidized nanofibrillated cellulose/biphasic calcium phosphate hydrogel for bone regeneration.

Science.gov (United States)

Safwat, Engie; Hassan, Mohammad L; Saniour, Sayed; Zaki, Dalia Yehia; Eldeftar, Mervat; Saba, Dalia; Zazou, Mohamed

2018-05-01

Nanofibrillated cellulose, obtained from rice straw agricultural wastes was used as a substrate for the preparation of a new injectable and mineralized hydrogel for bone regeneration. Tetramethyl pyridine oxyl (TEMPO) oxidized nanofibrillated cellulose, was mineralized through the incorporation of a prepared and characterized biphasic calcium phosphate at a fixed ratio of 50 wt%. The TEMPO-oxidized rice straw nanofibrillated cellulose was characterized using transmission electron microscopy, Fourier transform infrared, and carboxylic content determination. The injectability and viscosity of the prepared hydrogel were evaluated using universal testing machine and rheometer testing, respectively. Cytotoxicity and alkaline phosphatase level tests on osteoblast like-cells for in vitro assessment of the biocompatibility were investigated. Results revealed that the isolated rice straw nanofibrillated cellulose is a nanocomposite of the cellulose nanofibers and silica nanoparticles. Rheological properties of the tested materials are suitable for use as injectable material and of nontoxic effect on osteoblast-like cells, as revealed by the positive alkaline phosphate assay. However, nanofibrillated cellulose/ biphasic calcium phosphate hydrogel showed higher cytotoxicity and lower bioactivity test results when compared to that of nanofibrillated cellulose.

Distributional Replication

OpenAIRE

Beare, Brendan K.

2009-01-01

Suppose that X and Y are random variables. We define a replicating function to be a function f such that f(X) and Y have the same distribution. In general, the set of replicating functions for a given pair of random variables may be infinite. Suppose we have some objective function, or cost function, defined over the set of replicating functions, and we seek to estimate the replicating function with the lowest cost. We develop an approach to estimating the cheapest replicating function that i...

Chromatin Immunoprecipitation of Replication Factors Moving with the Replication Fork

OpenAIRE

Rapp, Jordan B.; Ansbach, Alison B.; Noguchi, Chiaki; Noguchi, Eishi

2009-01-01

Replication of chromosomes involves a variety of replication proteins including DNA polymerases, DNA helicases, and other accessory factors. Many of these proteins are known to localize at replication forks and travel with them as components of the replisome complex. Other proteins do not move with replication forks but still play an essential role in DNA replication. Therefore, in order to understand the mechanisms of DNA replication and its controls, it is important to examine localization ...

Paired Associative Stimulation Targeting the Tibialis Anterior Muscle using either Mono or Biphasic Transcranial Magnetic Stimulation

Directory of Open Access Journals (Sweden)

Natalie Mrachacz-Kersting

2017-04-01

Full Text Available Paired associative stimulation (PAS protocols induce plastic changes within the motor cortex. The objectives of this study were to investigate PAS effects targeting the tibialis anterior (TA muscle using a biphasic transcranial magnetic stimulation (TMS pulse form and, to determine whether a reduced intensity of this pulse would lead to significant changes as has been reported for hand muscles using a monophasic TMS pulse. Three interventions were investigated: (1 suprathreshold PAbi-PAS (n = 11; (2 suprathreshold PAmono-PAS (n = 11 where PAS was applied using a biphasic or monophasic pulse form at 120% resting motor threshold (RMT; (3 subthreshold PAbi-PAS (n = 10 where PAS was applied as for (1 at 95% active motor threshold (AMT. The peak-to-peak motor evoked potentials (MEPs were quantified prior to, immediately following, and 30 min after the cessation of the intervention. TA MEP size increased significantly for all interventions immediately post (61% for suprathreshold PAbi-PAS, 83% for suprathreshold PAmono-PAS, 55% for subthreshold PAbi-PAS and 30 min after the cessation of the intervention (123% for suprathreshold PAbi-PAS, 105% for suprathreshold PAmono-PAS, 80% for subthreshold PAbi-PAS. PAS using a biphasic pulse form at subthreshold intensities induces similar effects to conventional PAS.

Replication Catastrophe

DEFF Research Database (Denmark)

Toledo, Luis; Neelsen, Kai John; Lukas, Jiri

2017-01-01

Proliferating cells rely on the so-called DNA replication checkpoint to ensure orderly completion of genome duplication, and its malfunction may lead to catastrophic genome disruption, including unscheduled firing of replication origins, stalling and collapse of replication forks, massive DNA...... breakage, and, ultimately, cell death. Despite many years of intensive research into the molecular underpinnings of the eukaryotic replication checkpoint, the mechanisms underlying the dismal consequences of its failure remain enigmatic. A recent development offers a unifying model in which the replication...... checkpoint guards against global exhaustion of rate-limiting replication regulators. Here we discuss how such a mechanism can prevent catastrophic genome disruption and suggest how to harness this knowledge to advance therapeutic strategies to eliminate cancer cells that inherently proliferate under...

Biphasic cuirass ventilation is better than bag-valve mask ventilation for resuscitation following organophosphate poisoning

Directory of Open Access Journals (Sweden)

Ilan Gur

2015-01-01

Conclusions: The noninvasive, easy-to-operate Biphasic Cuirass Ventilation device was effective in reducing OP-induced mortality and might be advantageous in an organophosphate mass casualty event. This finding should be validated in further investigations.

Database Replication Prototype

OpenAIRE

Vandewall, R.

2000-01-01

This report describes the design of a Replication Framework that facilitates the implementation and com-parison of database replication techniques. Furthermore, it discusses the implementation of a Database Replication Prototype and compares the performance measurements of two replication techniques based on the Atomic Broadcast communication primitive: pessimistic active replication and optimistic active replication. The main contributions of this report can be split into four parts....

Marked heterogeneity in growth characteristics of myoblast clonal cultures and myoblast mixed cultures obtained from the same individual.

Science.gov (United States)

Maier, Andrea B; Cohen, Ron; Blom, Joke; van Heemst, Diana; Westendorp, Rudi G J

2012-01-01

Sarcopenia is defined as an age-related decrease in skeletal muscle mass and function while adjacent satellite cells are unable to compensate for this loss. However, myoblast cultures can be established even in the presence of sarcopenia. It is yet unknown whether satellite cells from failing muscle in older age are equally affected, as human satellite cells have been assessed using myoblast mixed cultures and not by using myoblast clonal cultures. We questioned to what extent myoblast mixed cultures reflect the in vivo characteristics of single satellite cells from adult skeletal muscle. We established a myoblast mixed culture and three myoblast clonal cultures out of the same muscle biopsy and cultured these cells for 100 days. Replicative capacity and oxidative stress resistance were compared. We found marked heterogeneity between the myoblast clonal cultures that all had a significantly lower replicative capacity when compared to the mixed culture. Replicative capacity of the clonal cultures was inversely related to the β-galactosidase activity after exposure to oxidative stress. Addition of L-carnosine enhanced the remaining replicative capacity in all cultures with a concomitant marginal decrease in β-galactosidase activity. It is concluded that myoblast mixed cultures in vitro do not reflect the marked heterogeneity between single isolated satellite cells. The consequences of the heterogeneity on muscle performance remain to be established. Copyright © 2011 S. Karger AG, Basel.

Biphasic activation of PI3K/Akt and MAPK/Erk1/2 signaling pathways in bovine herpesvirus type 1 infection of MDBK cells

Directory of Open Access Journals (Sweden)

Zhu Liqian

2011-04-01

Full Text Available Abstract Many viruses have been known to control key cellular signaling pathways to facilitate the virus infection. The possible involvement of signaling pathways in bovine herpesvirus type 1 (BoHV-1 infection is unknown. This study indicated that infection of MDBK cells with BoHV-1 induced an early-stage transient and a late-stage sustained activation of both phosphatidylinositol 3-kinase (PI3K/Akt and mitogen activated protein kinases/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2 signaling pathways. Analysis with the stimulation of UV-irradiated virus indicated that the virus binding and/or entry process was enough to trigger the early phase activations, while the late phase activations were viral protein expression dependent. Biphasic activation of both pathways was suppressed by the selective inhibitor, Ly294002 for PI3K and U0126 for MAPK kinase (MEK1/2, respectively. Furthermore, treatment of MDBK cells with Ly294002 caused a 1.5-log reduction in virus titer, while U0126 had little effect on the virus production. In addition, the inhibition effect of Ly294002 mainly occurred at the post-entry stage of the virus replication cycle. This revealed for the first time that BoHV-1 actively induced both PI3K/Akt and MAPK/Erk1/2 signaling pathways, and the activation of PI3K was important for fully efficient replication, especially for the post-entry stage.

Radiation-induced mutation frequency in marked chromosome of Macaca mulatta

International Nuclear Information System (INIS)

Dzhemilev, Z.A.; Machavariani, M.G.

1976-01-01

The symmetric and asymmetric exchange frequencies of marked (nucleolus forming) chromosomes were studied in the lymphocytes and epithelial kidney cells irradiated by X-rays at G 0 , both in vivo and in vitro. Symmetric and asymmetric exchange frequencies were found to be equal. In both the types of Macaca mulatta cells, the exchange frequency in the long arm appeared to be higher than theoretically expected. The increased exchange in the long arm is thought to be due to a greater quantity of late replicating heterochromatin in it. The short arm of marked chromosome of epithelial kidney cells enters the exchange in accordance to its length in mitosis, but exchange number in the short arm chromosome in lymphocytes is lower than in epithelial cells. This difference is caused likely by different functioning of the nucleolus forming heterochromatin. (author)

MDCT urography: experience with a bi-phasic excretory phase examination protocol

International Nuclear Information System (INIS)

Meindl, Thomas; Coppenrath, Eva; Degenhart, Christoph; Reiser, Maximilian F.; Mueller-Lisse, Ullrich G.; Mueller-Lisse, Ulrike L.

2007-01-01

The benefit of multidetector computed tomographic urography (MDCTU) for visualising early and late excretory phase (EP) upper urinary tract (UUT) opacification has been studied. UUT opacification was retrospectively evaluated in 45 bi-phasic four-row MDCTU examinations. The UUT was divided into intrarenal collecting system (IRCS), proximal, middle and distal ureter. Two independent readers rated opacification: 1, none; 2, partial; 3, complete. Numbers of segments and percentages of UUTs at each score were calculated for each EP and two EPs combined. Results of a single EP and of combined EPs were compared by Wilcoxon matched-pairs signed-ranks. IRCS and proximal ureter were at least partially opacified in each EP in >95%. The middle ureter was at least partially opacified in the early and late EP in 85% and 93%, respectively. The distal ureter was opacified in 65% (49/75) in the early EP and in 78% (59/75) in the late EP. Combining two EPs, non-opacified distal segments decreased to 9% (7/75). Significant improvement between a single EP and combining two EPs were found for the middle and distal ureter (P < 0.03). Bi-phasic MDCTU substantially improved opacification of the middle and distal ureter. IRCS and proximal ureter are reliably opacified with one EP. (orig.)

Switching from biphasic human insulin to biphasic insulin aspart 30 in type 2 diabetes: results from the ASEAN subgroup of the A₁chieve study.

Science.gov (United States)

Hussein, Zanariah; Lim-Abrahan, Mary Anne; Jain, Anand B; Goh, Su Yen; Soewondo, Pradana

2013-04-01

To evaluate the safety and effectiveness of biphasic insulin aspart 30 (BIAsp 30) in ASEAN type 2 diabetes (T2D) patients switched from biphasic human insulin (BHI) in the non-interventional 24-week A₁chieve study. Indonesian, Malaysian, Filipino and Singaporean patients switched from BHI to BIAsp 30 at their physicians' discretion were included. The incidence of serious adverse drug reactions (SADRs), including major hypoglycaemia was the primary endpoint. Changes in hypoglycaemia, glycated haemoglobin A1c (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPPG), lipids, body weight and systolic blood pressure were also evaluated. Quality of life (QoL) was measured using the EQ-5D questionnaire. For the 465 patients included (mean ± SD age: 56 ± 10.3 years, diabetes duration: 9.7 ± 7.1 years, baseline HbA1c: 9.4 ± 1.8%), the mean pre-study BHI dose was 0.62 ± 0.28 IU/kg and 63.4% were dosing BHI twice daily (bid). The mean baseline BIAsp 30 dose was 0.65 ± 0.27 U/kg, titrated up to 0.71 ± 0.28 U/kg over 24 weeks, and most patients continued bid dosing. No SADRs or major hypoglycaemic episodes were reported. The proportion of patients reporting overall hypoglycaemia decreased significantly from 10.8% at baseline to 3.4% at Week 24 (p ASEAN subgroup poorly controlled on BHI. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Application of aqueous biphasic systems as strategy to purify tannase from Aspergillus tamarii URM 7115.

Science.gov (United States)

de Sena, Amanda Reges; Barros Oliveira, Flávio Manoel; Campos Leite, Tonny Cley; Evaristo da Silva Nascimento, Talita Camila; Moreira, Keila Aparecida; de Assis, Sandra Aparecida

2017-10-21

The aims of the current study are to assess the influence of polyethylene glycol (PEG) concentration, molar mass, pH, and citrate concentrations on aqueous biphasic systems based on 2 4 factorial designs, as well as to check their capacity to purify tannase secreted by Aspergillus tamarii URM 7115. Tannase was produced through submerged fermentation at 26°C for 67 h in Czapeck-Dox modified broth and added with yeast extract and tannic acid. The factorial design was followed to assess the influence of PEG molar mass (M PEG 600; 4,000 and 8,000 g/ mol), and PEG (C PEG 20.0; 22.0 and 24.0% w/w) and citrate concentrations (C CIT 15.0, 17.5, and 20.0%, w/w), as well as of pH (6.0, 7.0, and 8.0) on the response variables; moreover, partition coefficient (K), yield (Y), and purification factor (PF) were analyzed. The most suitable parameters to purify tannase secreted by A. tamarii URM 7115 through a biphasic system were 600 (g/mol) M PEG , 24% (w/w) C PEG , 15% (w/w) C CIT at pH 6.0 and they resulted in 6.33 enzyme partition, 131.25% yield, 19.80 purification factor and 195.08 selectivity. Tannase secreted by A. tamarii URM 7115 purified through aqueous biphasic systems composed of PEG/citrate can be used for industrial purposes, since it presents suitable purification factor and yield.

Investigation of the transport properties of metals in the biphase region

International Nuclear Information System (INIS)

Oreshkin, V. I.; Rousskikh, A. G.; Chaikovsky, S. A.; Oreshkin, E. V.

2010-01-01

Results of experiments on electrical wire explosion are presented and processes of stratum formation and decay are analyzed in this paper. A procedure of calculating the transport coefficients from the rate of stratum damping is described. It is demonstrated that values of the transport coefficients for metals are not an unambiguous function of the material state in the biphase region for characteristic times of ∼10 -7 s but depend on the process prehistory.

A promising tritium breeding material: Nanostructured 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles

Science.gov (United States)

Dang, Chen; Yang, Mao; Gong, Yichao; Feng, Lan; Wang, Hailiang; Shi, Yanli; Shi, Qiwu; Qi, Jianqi; Lu, Tiecheng

2018-03-01

As an advanced tritium breeder material for the fusion reactor blanket of the International Thermonuclear Experimental Reactor (ITER), Li2TiO3-Li4SiO4 biphasic ceramic has attracted widely attention due to its merits. In this paper, the uniform precursor powders were prepared by hydrothermal method, and nanostructured 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles were fabricated by an indirect wet method at the first time. In addition, the composition dependence (x/y) of their microstructure characteristics and mechanical properties were investigated. The results indicated that the crush load of biphasic ceramic pebbles was better than that of single phase ceramic pebbles under identical conditions. The 2Li2TiO3-Li4SiO4 ceramic pebbles have good morphology, small grain size (90 nm), satisfactory crush load (37.8 N) and relative density (81.8 %T.D.), which could be a promising breeding material in the future fusion reactor.

The Replication Recipe: What makes for a convincing replication?

NARCIS (Netherlands)

Brandt, M.J.; IJzerman, H.; Dijksterhuis, A.J.; Farach, F.J.; Geller, J.; Giner-Sorolla, R.; Grange, J.A.; Perugini, M.; Spies, J.R.; Veer, A. van 't

2014-01-01

Psychological scientists have recently started to reconsider the importance of close replications in building a cumulative knowledge base; however, there is no consensus about what constitutes a convincing close replication study. To facilitate convincing close replication attempts we have developed

The replication recipe : What makes for a convincing replication?

NARCIS (Netherlands)

Brandt, M.J.; IJzerman, H.; Dijksterhuis, Ap; Farach, Frank J.; Geller, Jason; Giner-Sorolla, Roger; Grange, James A.; Perugini, Marco; Spies, Jeffrey R.; van 't Veer, Anna

Psychological scientists have recently started to reconsider the importance of close replications in building a cumulative knowledge base; however, there is no consensus about what constitutes a convincing close replication study. To facilitate convincing close replication attempts we have developed

Design and development of a low-cost biphasic charge-balanced functional electric stimulator and its clinical validation.

Science.gov (United States)

Shendkar, Chandrashekhar; Lenka, Prasanna K; Biswas, Abhishek; Kumar, Ratnesh; Mahadevappa, Manjunatha

2015-10-01

Functional electric stimulators that produce near-ideal, charge-balanced biphasic stimulation waveforms with interphase delay are considered safer and more efficacious than conventional stimulators. An indigenously designed, low-cost, portable FES device named InStim is developed. It features a charge-balanced biphasic single channel. The authors present the complete design, mathematical analysis of the circuit and the clinical evaluation of the device. The developed circuit was tested on stroke patients affected by foot drop problems. It was tested both under laboratory conditions and in clinical settings. The key building blocks of this circuit are low dropout regulators, a DC-DC voltage booster and a single high-power current source OP-Amp with current-limiting capabilities. This allows the device to deliver high-voltage, constant current, biphasic pulses without the use of a bulky step-up transformer. The advantages of the proposed design over the currently existing devices include improved safety features (zero DC current, current-limiting mechanism and safe pulses), waveform morphology that causes less muscle fatigue, cost-effectiveness and compact power-efficient circuit design with minimal components. The device is also capable of producing appropriate ankle dorsiflexion in patients having foot drop problems of various Medical Research Council scale grades.

A randomized trial comparing monophasic and biphasic waveform shocks for external cardioversion of atrial fibrillation

NARCIS (Netherlands)

Koster, Rudolph W.; Dorian, Paul; Chapman, Fred W.; Schmitt, Paul W.; O'Grady, Sharon G.; Walker, Robert G.

2004-01-01

Background We compared efficacy of and pain felt after biphasic truncated exponential (BTE) and monophasic damped sine (MDS) shocks in patients undergoing external cardioversion of atrial fibrillation (AF). Methods Patients with AF were randomized to BTE or MDS waveform cardioversion. Successive

Biphasic effect of arsenite on cell proliferation and apoptosis is associated with the activation of JNK and ERK1/2 in human embryo lung fibroblast cells

International Nuclear Information System (INIS)

He Xiaoqing; Chen Rui; Yang Ping; Li Aiping; Zhou Jianwei; Liu Qizhan

2007-01-01

Biphasic dose-response relationship induced by environmental agents is often characterized with the effect of low-dose stimulation and high-dose inhibition. Some studies showed that arsenite may induce cell proliferation and apoptosis via biphasic dose-response relationship in human cells; however, mechanisms underlying this phenomenon are not well understood. In the present study, we aimed at investigating the relationship between biphasic effect of arsenite on cell proliferation and apoptosis and activation of JNK and ERK1/2 in human embryo lung fibroblast (HELF) cells. Our results demonstrated that cell proliferation may be stimulated at lower concentrations (0.1 and 0.5 μM) arsenite but inhibited at higher concentrations (5 and 10 μM). When cell apoptosis was used as the endpoint, the concentration-response curves were changed to U-shapes. During stimulation phospho-JNK levels were significantly increased at 3, 6, and 12 h after 0.1 or 0.5 μM arsenite exposure. Phospho-ERK1/2 levels were increased with different concentrations (0.1-10 μM) of arsenite at 6, 12, and 24 h. Blocking of JNK pathway with 20 μM SP600125 or ERK1/2 by 100 μM PD98059 significantly inhibited biphasic effect of arsenite in cells. Data in the present study suggest that activation of JNK and ERK1/2 may be involved in biphasic effect of arsenite when measuring cell proliferation and apoptosis in HELF cells. JNK activation seems to play a more critical role than ERK1/2 activation in the biphasic process

Preparation of highly infective Leishmania promastigotes by cultivation on SNB-9 biphasic medium

Czech Academy of Sciences Publication Activity Database

Grekov, Igor; Svobodová, M.; Nohýnková, E.; Lipoldová, Marie

2011-01-01

Roč. 87, č. 3 (2011), s. 273-277 ISSN 0167-7012 R&D Projects: GA MŠk(CZ) LC06009; GA ČR GA310/08/1697 Institutional research plan: CEZ:AV0Z50520514 Keywords : Leishmania * SNB-9 * biphasic culture medium * parasite infectivity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.086, year: 2011

Average current is better than peak current as therapeutic dosage for biphasic waveforms in a ventricular fibrillation pig model of cardiac arrest.

Science.gov (United States)

Chen, Bihua; Yu, Tao; Ristagno, Giuseppe; Quan, Weilun; Li, Yongqin

2014-10-01

Defibrillation current has been shown to be a clinically more relevant dosing unit than energy. However, the effects of average and peak current in determining shock outcome are still undetermined. The aim of this study was to investigate the relationship between average current, peak current and defibrillation success when different biphasic waveforms were employed. Ventricular fibrillation (VF) was electrically induced in 22 domestic male pigs. Animals were then randomized to receive defibrillation using one of two different biphasic waveforms. A grouped up-and-down defibrillation threshold-testing protocol was used to maintain the average success rate of 50% in the neighborhood. In 14 animals (Study A), defibrillations were accomplished with either biphasic truncated exponential (BTE) or rectilinear biphasic waveforms. In eight animals (Study B), shocks were delivered using two BTE waveforms that had identical peak current but different waveform durations. Both average and peak currents were associated with defibrillation success when BTE and rectilinear waveforms were investigated. However, when pathway impedance was less than 90Ω for the BTE waveform, bivariate correlation coefficient was 0.36 (p=0.001) for the average current, but only 0.21 (p=0.06) for the peak current in Study A. In Study B, a high defibrillation success (67.9% vs. 38.8%, pcurrent (14.9±2.1A vs. 13.5±1.7A, pcurrent unchanged. In this porcine model of VF, average current was better than peak current to be an adequate parameter to describe the therapeutic dosage when biphasic defibrillation waveforms were used. The institutional protocol number: P0805. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effect of nasal continuous and biphasic positive airway pressure on lung volume in preterm infants

NARCIS (Netherlands)

Miedema, Martijn; van der Burg, Pauline S.; Beuger, Sabine; de Jongh, Frans H.; Frerichs, Inez; van Kaam, Anton H.

2013-01-01

To monitor regional changes in end-expiratory lung volume (EELV), tidal volumes, and their ventilation distribution during different levels of nasal continuous positive airway pressure (nCPAP) and nasal biphasic positive airway pressure (BiPAP) in stable preterm infants. By using electrical

Regional differences in DNA replication in nasal epithelium following acute ozone or cigarette smoke exposure

International Nuclear Information System (INIS)

Johnson, N.F.; Hotchkiss, J.A.; Harkema, J.R.; Henderson, R.F.; Mauderly, J.L.; Cuddihy, R.G.

1988-01-01

The epithelium of the anterior nasal cavity is composed of four cell types, squamous, respiratory, cuboidal, and olfactory cells. We monitored proliferation In these tissues by bromodeoxy-uridine (BrdUrd) incorporation; the labeled cells were identified by using a monoclonal antibody that recognizes BrdUrd. The respiratory, cuboidal and olfactory epithelia had low cell turnover (1-labeled ceIl/mm basal lamina). Squamous epithelium contained 40-labeled cells per mm basal lamina. Following exposure to diluted mainstream cigarette smoke, a transient, but marked increase in DNA replication was seen in the cuboidal epithelium. In contrast, ozone exposure was associated with DNA replication in the olfactory and respiratory epithelium, as well as in the cuboidal epithelium. These studies show that the sensitivity of nasal epithelium to irritants can be assayed by measuring DNA replication. (author)

Regional differences in DNA replication in nasal epithelium following acute ozone or cigarette smoke exposure

Energy Technology Data Exchange (ETDEWEB)

Johnson, N F; Hotchkiss, J A; Harkema, J R; Henderson, R F; Mauderly, J L; Cuddihy, R G

1988-12-01

The epithelium of the anterior nasal cavity is composed of four cell types, squamous, respiratory, cuboidal, and olfactory cells. We monitored proliferation In these tissues by bromodeoxy-uridine (BrdUrd) incorporation; the labeled cells were identified by using a monoclonal antibody that recognizes BrdUrd. The respiratory, cuboidal and olfactory epithelia had low cell turnover (1-labeled ceIl/mm basal lamina). Squamous epithelium contained 40-labeled cells per mm basal lamina. Following exposure to diluted mainstream cigarette smoke, a transient, but marked increase in DNA replication was seen in the cuboidal epithelium. In contrast, ozone exposure was associated with DNA replication in the olfactory and respiratory epithelium, as well as in the cuboidal epithelium. These studies show that the sensitivity of nasal epithelium to irritants can be assayed by measuring DNA replication. (author)

* Fabrication and Characterization of Biphasic Silk Fibroin Scaffolds for Tendon/Ligament-to-Bone Tissue Engineering.

Science.gov (United States)

Font Tellado, Sònia; Bonani, Walter; Balmayor, Elizabeth R; Foehr, Peter; Motta, Antonella; Migliaresi, Claudio; van Griensven, Martijn

2017-08-01

Tissue engineering is an attractive strategy for tendon/ligament-to-bone interface repair. The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons/ligaments and bone. Thus, scaffolds mimicking the structural features of the native interface may be able to better support functional tissue regeneration. In this study, we fabricated biphasic silk fibroin scaffolds designed to mimic the gradient in collagen molecule alignment present at the interface. The scaffolds had two different pore alignments: anisotropic at the tendon/ligament side and isotropic at the bone side. Total porosity ranged from 50% to 80% and the majority of pores (80-90%) were ligament, enthesis, and cartilage markers significantly changed depending on pore alignment in each region of the scaffolds. In conclusion, the biphasic scaffolds fabricated in this study show promising features for tendon/ligament-to-bone tissue engineering.

USP37 deubiquitinates Cdt1 and contributes to regulate DNA replication.

Science.gov (United States)

Hernández-Pérez, Santiago; Cabrera, Elisa; Amoedo, Hugo; Rodríguez-Acebes, Sara; Koundrioukoff, Stephane; Debatisse, Michelle; Méndez, Juan; Freire, Raimundo

2016-10-01

DNA replication control is a key process in maintaining genomic integrity. Monitoring DNA replication initiation is particularly important as it needs to be coordinated with other cellular events and should occur only once per cell cycle. Crucial players in the initiation of DNA replication are the ORC protein complex, marking the origin of replication, and the Cdt1 and Cdc6 proteins, that license these origins to replicate by recruiting the MCM2-7 helicase. To accurately achieve its functions, Cdt1 is tightly regulated. Cdt1 levels are high from metaphase and during G1 and low in S/G2 phases of the cell cycle. This control is achieved, among other processes, by ubiquitination and proteasomal degradation. In an overexpression screen for Cdt1 deubiquitinating enzymes, we isolated USP37, to date the first ubiquitin hydrolase controlling Cdt1. USP37 overexpression stabilizes Cdt1, most likely a phosphorylated form of the protein. In contrast, USP37 knock down destabilizes Cdt1, predominantly during G1 and G1/S phases of the cell cycle. USP37 interacts with Cdt1 and is able to de-ubiquitinate Cdt1 in vivo and, USP37 is able to regulate the loading of MCM complexes onto the chromatin. In addition, downregulation of USP37 reduces DNA replication fork speed. Taken together, here we show that the deubiquitinase USP37 plays an important role in the regulation of DNA replication. Whether this is achieved via Cdt1, a central protein in this process, which we have shown to be stabilized by USP37, or via additional factors, remains to be tested. Copyright © 2016 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Characterization of the replication timing program of 6 human model cell lines

Directory of Open Access Journals (Sweden)

Djihad Hadjadj

2016-09-01

Full Text Available During the S-phase, the DNA replication process is finely orchestrated and regulated by two programs: the spatial program that determines where replication will start in the genome (Cadoret et al. (2008 Oct 14, Cayrou et al. (2011 Sep, Picard et al. (2014 May 1 [1–3], and the temporal program that determines when during the S phase different parts of the genome are replicated and when origins are activated. The temporal program is so well conserved for each cell type from independent individuals [4] that it is possible to identify a cell type from an unknown sample just by determining its replication timing program. Moreover, replicative domains are strongly correlated with the partition of the genome into topological domains (determined by the Hi-C method, Lieberman-Aiden et al. (2009 Oct 9, Pope et al. (2014 Nov 20 [5,6]. On the one hand, replicative areas are well defined and participate in shaping the spatial organization of the genome for a given cell type. On the other hand, studies on the timing program during cell differentiation showed a certain plasticity of this program according to the stage of cell differentiation Hiratani et al. (2008 Oct 7, 2010 Feb [7,8]. Domains where a replication timing change was observed went through a nuclear re-localization. Thus the temporal program of replication can be considered as an epigenetic mark Hiratani and Gilbert (2009 Feb 16 [9]. We present the genomic data of replication timing in 6 human model cell lines: U2OS (GSM2111308, RKO (GSM2111309, HEK 293T (GSM2111310, HeLa (GSM2111311, MRC5-SV (GSM2111312 and K562 (GSM2111313. A short comparative analysis was performed that allowed us to define regions common to the 6 cell lines. These replication timing data can be taken into account when performing studies that use these model cell lines.

Selective formation of biphasic thin films of metal–organic frameworks by potential-controlled cathodic electrodeposition

OpenAIRE

Li, Minyuan Miller; Dinca, Mircea

2013-01-01

Cathodic electrodeposition lends itself to the formation of biphasic metal–organic framework thin films at room temperature from single deposition baths using potential bias as the main user input. Depending on the applied potential, we selectively deposit two different phases as either bulk mixtures or bilayer films.

High-Resolution Profiling of Drosophila Replication Start Sites Reveals a DNA Shape and Chromatin Signature of Metazoan Origins

Directory of Open Access Journals (Sweden)

Federico Comoglio

2015-05-01

Full Text Available At every cell cycle, faithful inheritance of metazoan genomes requires the concerted activation of thousands of DNA replication origins. However, the genetic and chromatin features defining metazoan replication start sites remain largely unknown. Here, we delineate the origin repertoire of the Drosophila genome at high resolution. We address the role of origin-proximal G-quadruplexes and suggest that they transiently stall replication forks in vivo. We dissect the chromatin configuration of replication origins and identify a rich spatial organization of chromatin features at initiation sites. DNA shape and chromatin configurations, not strict sequence motifs, mark and predict origins in higher eukaryotes. We further examine the link between transcription and origin firing and reveal that modulation of origin activity across cell types is intimately linked to cell-type-specific transcriptional programs. Our study unravels conserved origin features and provides unique insights into the relationship among DNA topology, chromatin, transcription, and replication initiation across metazoa.

Obtaining of ceramics biphasic dense and porous

International Nuclear Information System (INIS)

Pallone, E.M.J.A.; Rigo, E.C.S.; Fraga, A.F.

2010-01-01

Among the bioceramic hydroxyapatite (HAP) and beta-tricalcium phosphate (beta-TCP) are materials commonly used in biomedical field. Their combined properties result in a material with absorbable and at the same time with bioactive surface. Called biphasic ceramics such materials respond more quickly when exposed to physiological environment. In this work, powders of HAP/beta-TCP were obtained by chemical precipitation. After obtaining the post-phase was added at a ratio of 0, 15% and 30w% aqueous solutions of corn starch in order to obtain porous bodies. After mixing the resulting solutions were dried, resigned in tablet form and sintered at 1300 deg C. The initial powder was characterized by X-ray diffraction with Rietveld refinement to quantify the phases present. Bodies-of-evidence has been characterized by calculating the bulk density, X-ray diffraction (XRD), scanning electron microscopy and diametral compression. (author)

Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

Energy Technology Data Exchange (ETDEWEB)

Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun, E-mail: 1044208419@qq.com; Mao, Hui, E-mail: rejoice222@163.com [Sichuan Normal University, College of Chemistry and Materials Science (China)

2016-10-15

Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85–2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous–organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al{sub 2}O{sub 3} catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

Efficient One-Pot Synthesis of 5-Chloromethylfurfural (CMF from Carbohydrates in Mild Biphasic Systems

Directory of Open Access Journals (Sweden)

Dimitris S. Argyropoulos

2013-07-01

Full Text Available 5-Halomethylfurfurals can be considered as platform chemicals of high reactivity making them useful for the preparation of a variety of important compounds. In this study, a one-pot route for the conversion of carbohydrates into 5-chloromethylfurfural (CMF in a simple and efficient (HCl-H3PO4/CHCl3 biphasic system has been investigated. Monosaccharides such as D-fructose, D-glucose and sorbose, disaccharides such as sucrose and cellobiose and polysaccharides such as cellulose were successfully converted into CMF in satisfactory yields under mild conditions. Our data shows that when using D-fructose the optimum yield of CMF was about 47%. This understanding allowed us to extent our work to biomaterials, such as wood powder and wood pulps with yields of CMF obtained being comparable to those seen with some of the enumerated mono and disaccharides. Overall, the proposed (HCl-H3PO4/CHCl3 optimized biphasic system provides a simple, mild, and cost-effective means to prepare CMF from renewable resources.

Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

International Nuclear Information System (INIS)

Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun; Mao, Hui

2016-01-01

Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85–2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous–organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al 2 O 3 catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

Application of a Three-Dimensional Poroelastic BEM to Modeling the Biphasic Mechanics of Cell-Matrix Interactions in Articular Cartilage (REVISION).

Science.gov (United States)

Haider, Mansoor A; Guilak, Farshid

2007-06-15

Articular cartilage exhibits viscoelasticity in response to mechanical loading that is well described using biphasic or poroelastic continuum models. To date, boundary element methods (BEMs) have not been employed in modeling biphasic tissue mechanics. A three dimensional direct poroelastic BEM, formulated in the Laplace transform domain, is applied to modeling stress relaxation in cartilage. Macroscopic stress relaxation of a poroelastic cylinder in uni-axial confined compression is simulated and validated against a theoretical solution. Microscopic cell deformation due to poroelastic stress relaxation is also modeled. An extended Laplace inversion method is employed to accurately represent mechanical responses in the time domain.

Replicative Intermediates of Human Papillomavirus Type 11 in Laryngeal Papillomas: Site of Replication Initiation and Direction of Replication

Science.gov (United States)

Auborn, K. J.; Little, R. D.; Platt, T. H. K.; Vaccariello, M. A.; Schildkraut, C. L.

1994-07-01

We have examined the structures of replication intermediates from the human papillomavirus type 11 genome in DNA extracted from papilloma lesions (laryngeal papillomas). The sites of replication initiation and termination utilized in vivo were mapped by using neutral/neutral and neutral/alkaline two-dimensional agarose gel electrophoresis methods. Initiation of replication was detected in or very close to the upstream regulatory region (URR; the noncoding, regulatory sequences upstream of the open reading frames in the papillomavirus genome). We also show that replication forks proceed bidirectionally from the origin and converge 180circ opposite the URR. These results demonstrate the feasibility of analysis of replication of viral genomes directly from infected tissue.

DNA replication and cancer: From dysfunctional replication origin activities to therapeutic opportunities.

Science.gov (United States)

Boyer, Anne-Sophie; Walter, David; Sørensen, Claus Storgaard

2016-06-01

A dividing cell has to duplicate its DNA precisely once during the cell cycle to preserve genome integrity avoiding the accumulation of genetic aberrations that promote diseases such as cancer. A large number of endogenous impacts can challenge DNA replication and cells harbor a battery of pathways to promote genome integrity during DNA replication. This includes suppressing new replication origin firing, stabilization of replicating forks, and the safe restart of forks to prevent any loss of genetic information. Here, we describe mechanisms by which oncogenes can interfere with DNA replication thereby causing DNA replication stress and genome instability. Further, we describe cellular and systemic responses to these insults with a focus on DNA replication restart pathways. Finally, we discuss the therapeutic potential of exploiting intrinsic replicative stress in cancer cells for targeted therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Posterior mediastinal biphasic synovial sarcoma in a 12 year-old boy: A case report and review of literature

Directory of Open Access Journals (Sweden)

Pal Madhumay

2010-01-01

Full Text Available We report a case of biphasic synovial sarcoma of the mediastinum, a very rare tumor, in a 12-year-old boy with left-sided chest pain of 3 years duration at presentation. Chest X-ray showed left-sided opacity with loss of cardiac silhouette and the mediastinum deviated to the opposite side. Computed tomography (CT of thorax showed left-sided posterior mediastinal mass with left-sided pleural effusion and pleural thickening. CT guided fine needle aspiration cytology (FNAC from the mass reported it as spindle cell variant of adenocarcinoma. Ultrasonography (USG of the whole abdomen revealed no abnormality. The mediastinal tumor was resected by left thoracotomy and histopathological report confirmed it to be a biphasic synovial sarcoma with capsule invasion at places.

Biphasic products of dicalcium phosphate-rich cement with injectability and nondispersibility

International Nuclear Information System (INIS)

Ko, Chia-Ling; Chen, Jian-Chih; Hung, Chun-Cheng; Wang, Jen-Chyan; Tien, Yin-Chun; Chen, Wen-Cheng

2014-01-01

In this study, a calcium phosphate cement was developed using tetracalcium phosphate and surface-modified dicalcium phosphate anhydrous (DCPA). This developed injectable bone graft substitute can be molded to the shape of the bone cavity and set in situ through the piping system that has an adequate mechanical strength, non-dispersibility, and biocompatibility. The materials were based on the modified DCPA compositions of calcium phosphate cement (CPC), where the phase ratio of the surface-modified DCPA is higher than that of the conventional CPC for forming dicalcium phosphate (DCP)-rich cement. The composition and morphology of several calcium phosphate cement specimens during setting were analyzed via X-ray diffractometry and transmission electron microscopy coupled with an energy dispersive spectroscopy system. The compressive strength of DCP-rich CPCs was greater than 30 MPa after 24 h of immersion in vitro. The reaction of the CPCs produced steady final biphasic products of DCPs with apatite. The composites of calcium phosphate cements derived from tetracalcium phosphate mixed with surface-modified DCPA exhibited excellent mechanical properties, injectability, and interlocking forces between particles, and they also featured nondispersive behavior when immersed in a physiological solution. - Highlights: • Bone cement precursor with nanocrystals is characterized. • DCP-rich CPCs with nanocrystals exhibited biphasic product phases. • Nanocrystals in cement significantly affected the interlocking ability. • Nanocrystals in cement exhibited higher strength and anti-dispersion. • DCP-rich CPCs increase the potential of bioresorption after reaction

Repair replication in replicating and nonreplicating DNA after irradiation with uv light

Energy Technology Data Exchange (ETDEWEB)

Slor, H.; Cleaver, J.E.

1978-06-01

Ultraviolet light induces more pyrimidine dimers and more repair replication in DNA that replicates within 2 to 3 h of irradiation than in DNA that does not replicate during this period. This difference may be due to special conformational changes in DNA and chromatin that might be associated with semiconservative DNA replication.

Human Parvovirus B19 Utilizes Cellular DNA Replication Machinery for Viral DNA Replication.

Science.gov (United States)

Zou, Wei; Wang, Zekun; Xiong, Min; Chen, Aaron Yun; Xu, Peng; Ganaie, Safder S; Badawi, Yomna; Kleiboeker, Steve; Nishimune, Hiroshi; Ye, Shui Qing; Qiu, Jianming

2018-03-01

Human parvovirus B19 (B19V) infection of human erythroid progenitor cells (EPCs) induces a DNA damage response and cell cycle arrest at late S phase, which facilitates viral DNA replication. However, it is not clear exactly which cellular factors are employed by this single-stranded DNA virus. Here, we used microarrays to systematically analyze the dynamic transcriptome of EPCs infected with B19V. We found that DNA metabolism, DNA replication, DNA repair, DNA damage response, cell cycle, and cell cycle arrest pathways were significantly regulated after B19V infection. Confocal microscopy analyses revealed that most cellular DNA replication proteins were recruited to the centers of viral DNA replication, but not the DNA repair DNA polymerases. Our results suggest that DNA replication polymerase δ and polymerase α are responsible for B19V DNA replication by knocking down its expression in EPCs. We further showed that although RPA32 is essential for B19V DNA replication and the phosphorylated forms of RPA32 colocalized with the replicating viral genomes, RPA32 phosphorylation was not necessary for B19V DNA replication. Thus, this report provides evidence that B19V uses the cellular DNA replication machinery for viral DNA replication. IMPORTANCE Human parvovirus B19 (B19V) infection can cause transient aplastic crisis, persistent viremia, and pure red cell aplasia. In fetuses, B19V infection can result in nonimmune hydrops fetalis and fetal death. These clinical manifestations of B19V infection are a direct outcome of the death of human erythroid progenitors that host B19V replication. B19V infection induces a DNA damage response that is important for cell cycle arrest at late S phase. Here, we analyzed dynamic changes in cellular gene expression and found that DNA metabolic processes are tightly regulated during B19V infection. Although genes involved in cellular DNA replication were downregulated overall, the cellular DNA replication machinery was tightly

MOF Suppresses Replication Stress and Contributes to Resolution of Stalled Replication Forks.

Science.gov (United States)

Singh, Dharmendra Kumar; Pandita, Raj K; Singh, Mayank; Chakraborty, Sharmistha; Hambarde, Shashank; Ramnarain, Deepti; Charaka, Vijaya; Ahmed, Kazi Mokim; Hunt, Clayton R; Pandita, Tej K

2018-03-15

The human MOF (hMOF) protein belongs to the MYST family of histone acetyltransferases and plays a critical role in transcription and the DNA damage response. MOF is essential for cell proliferation; however, its role during replication and replicative stress is unknown. Here we demonstrate that cells depleted of MOF and under replicative stress induced by cisplatin, hydroxyurea, or camptothecin have reduced survival, a higher frequency of S-phase-specific chromosome damage, and increased R-loop formation. MOF depletion decreased replication fork speed and, when combined with replicative stress, also increased stalled replication forks as well as new origin firing. MOF interacted with PCNA, a key coordinator of replication and repair machinery at replication forks, and affected its ubiquitination and recruitment to the DNA damage site. Depletion of MOF, therefore, compromised the DNA damage repair response as evidenced by decreased Mre11, RPA70, Rad51, and PCNA focus formation, reduced DNA end resection, and decreased CHK1 phosphorylation in cells after exposure to hydroxyurea or cisplatin. These results support the argument that MOF plays an important role in suppressing replication stress induced by genotoxic agents at several stages during the DNA damage response. Copyright © 2018 American Society for Microbiology.

Database Replication

CERN Document Server

Kemme, Bettina

2010-01-01

Database replication is widely used for fault-tolerance, scalability and performance. The failure of one database replica does not stop the system from working as available replicas can take over the tasks of the failed replica. Scalability can be achieved by distributing the load across all replicas, and adding new replicas should the load increase. Finally, database replication can provide fast local access, even if clients are geographically distributed clients, if data copies are located close to clients. Despite its advantages, replication is not a straightforward technique to apply, and

A Physicochemically Optimized and Neuroconductive Biphasic Nerve Guidance Conduit for Peripheral Nerve Repair.

Science.gov (United States)

Ryan, Alan J; Lackington, William A; Hibbitts, Alan J; Matheson, Austyn; Alekseeva, Tijna; Stejskalova, Anna; Roche, Phoebe; O'Brien, Fergal J

2017-12-01

Clinically available hollow nerve guidance conduits (NGCs) have had limited success in treating large peripheral nerve injuries. This study aims to develop a biphasic NGC combining a physicochemically optimized collagen outer conduit to bridge the transected nerve, and a neuroconductive hyaluronic acid-based luminal filler to support regeneration. The outer conduit is mechanically optimized by manipulating crosslinking and collagen density, allowing the engineering of a high wall permeability to mitigate the risk of neuroma formation, while also maintaining physiologically relevant stiffness and enzymatic degradation tuned to coincide with regeneration rates. Freeze-drying is used to seamlessly integrate the luminal filler into the conduit, creating a longitudinally aligned pore microarchitecture. The luminal stiffness is modulated to support Schwann cells, with laminin incorporation further enhancing bioactivity by improving cell attachment and metabolic activity. Additionally, this biphasic NGC is shown to support neurogenesis and gliogenesis of neural progenitor cells and axonal outgrowth from dorsal root ganglia. These findings highlight the paradigm that a successful NGC requires the concerted optimization of both a mechanical support phase capable of bridging a nerve defect and a neuroconductive phase with an architecture capable of supporting both Schwann cells and neurons in order to achieve functional regenerative outcome. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isoattenuating insulinomas at biphasic contrast-enhanced CT: frequency, clinicopathologic features and perfusion characteristics

Energy Technology Data Exchange (ETDEWEB)

Zhu, Liang; Xue, Hua-dan; Sun, Hao; Wang, Xuan; He, Yong-lan; Jin, Zheng-yu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Zhao, Yu-pei [Peking Union Medical College Hospital, Department of General Surgery, Beijing (China)

2016-10-15

We aimed to determine the frequency of isoattenuating insulinomas, to investigate their clinicopathological features and to assess their regional pancreatic perfusion characteristics. Institutional review board approval was obtained, and patient informed consent was waived. From July 2010 to June 2014, 170 patients (66 male, 104 female) with endogenous hyperinsulinemic hypoglycemia underwent biphasic contrast-enhanced CT before surgery, and 129 of those patients also received preoperative whole-pancreas CT perfusion. A total of 181 tumours were proved histopathologically after surgery. Enhancement pattern and regional pancreatic perfusion characteristics were analyzed. Clinical features, tumour size and pathological grading were investigated. The frequency of isoattenuating tumours was 24.9 %. Tumour size and WHO grading was not significantly different between isoattenuating and hyperattenuating tumours. Tumour-free regions had identical blood flow (BF) regardless of their location (p = 0.35). Isoattenuating tumour-harbouring regions had lower BF compared with hyperattenuating tumour-harbouring regions; both showed higher BF compared with tumour-free neighbourhood regions (all p < 0.01). For patients with isoattenuating tumours, the overall hospital stay was longer (p < 0.01). A substantial subset of insulinomas were isoattenuating on biphasic CT. CT perfusion showed higher BF in tumour-harbouring regions compared to tumour-free regions, providing a clue for tumour regionalization. (orig.)

Synthesis of biphasic calcium phosphate containing nanostructured films by micro arc oxidation on magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Seyfoori, A., E-mail: klm.1985@yahoo.com [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Tehran (Iran, Islamic Republic of); National Cell Bank, Pasteur Institute of Iran, 13164 Tehran (Iran, Islamic Republic of); Mirdamadi, Sh.; Seyedraoufi, Z.S.; Khavandi, A. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Tehran (Iran, Islamic Republic of); Aliofkhazraei, M. [Department of Materials Engineering, Faculty of Engineering, Tarbiat Modares University, 14115-143 Tehran (Iran, Islamic Republic of)

2013-10-01

The present research reports the synthesis of an innovative nanostructured composite film containing biphasic calcium phosphate (BCP) by the micro arc oxidation (MAO) method on AZ31 magnesium alloy. Nanometric structure of the used hydroxyapatite powder and the coatings were characterized by means of transmission and field-emission scanning electron microscope, respectively. Electrochemical behaviors of the pure MAO and nanocomposite films were also evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests in simulated body fluid (SBF) environment. The results showed higher corrosion resistance of nanocomposite film compared to pure MAO coating, which was related to the blocking feature of the nanoparticles from the diffusing of the corrosive medium through the substrate. In addition, by immersing the specimens in simulated body fluid, greater apatite forming ability of the nanocomposite coating was proved. - Highlights: • Synthesis of innovative biphasic calcium phosphate containing nanostructured films via micro arc oxidation. • Nanocomposite film has lower degradation rate than pure MAO film. • Greater apatite forming ability for nanocomposite coating compared with pure MAO film is obtained.

Lignocellulose fractionation into furfural and glucose by AlCl3-catalyzed DES/MIBK biphasic pretreatment.

Science.gov (United States)

Wang, Zhi-Kun; Shen, Xiao-Jun; Chen, Jun-Jie; Jiang, Ying-Qiu; Hu, Zhi-Yan; Wang, Xing; Liu, Li

2018-06-01

Herein, an efficient DES/MIBK biphasic pretreatment system for preparation of furfural and fermentable glucose from lignocellulose was developed with AlCl 3 as catalysis. The low-cost and renewable DES (Choline chloride-Oxalic acid) served not only as a Brønsted acid catalyst, but also as a pretreatment solvent in present work, and MIBK as an extracting reagent which can increase the yield of furfural in DES phase. The effects of this biphasic pretreatment on the furfural yield and saccharification of the lignocellulose before and after pretreatment were explored using HPLC, HAPEC, FT-IR, XRD and SEM. Under the best pretreatment condition (at 140 °C for 90 min), furfural could be obtained in 70.3% yield and 80.8% of the pretreated lignocellulose was saccharified, which was 8.4 times higher than that of the raw lignocellulose without pretreatment. In a word, this pretreatment system can be considered as a potential technique for efficient valorization of lignocellulose for production of furfural and fermentable glucose. Copyright © 2018. Published by Elsevier B.V.

Synthesis of biphasic calcium phosphate containing nanostructured films by micro arc oxidation on magnesium alloy

International Nuclear Information System (INIS)

Seyfoori, A.; Mirdamadi, Sh.; Seyedraoufi, Z.S.; Khavandi, A.; Aliofkhazraei, M.

2013-01-01

The present research reports the synthesis of an innovative nanostructured composite film containing biphasic calcium phosphate (BCP) by the micro arc oxidation (MAO) method on AZ31 magnesium alloy. Nanometric structure of the used hydroxyapatite powder and the coatings were characterized by means of transmission and field-emission scanning electron microscope, respectively. Electrochemical behaviors of the pure MAO and nanocomposite films were also evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests in simulated body fluid (SBF) environment. The results showed higher corrosion resistance of nanocomposite film compared to pure MAO coating, which was related to the blocking feature of the nanoparticles from the diffusing of the corrosive medium through the substrate. In addition, by immersing the specimens in simulated body fluid, greater apatite forming ability of the nanocomposite coating was proved. - Highlights: • Synthesis of innovative biphasic calcium phosphate containing nanostructured films via micro arc oxidation. • Nanocomposite film has lower degradation rate than pure MAO film. • Greater apatite forming ability for nanocomposite coating compared with pure MAO film is obtained

Online Epileptic Seizure Prediction Using Wavelet-Based Bi-Phase Correlation of Electrical Signals Tomography.

Science.gov (United States)

Vahabi, Zahra; Amirfattahi, Rasoul; Shayegh, Farzaneh; Ghassemi, Fahimeh

2015-09-01

Considerable efforts have been made in order to predict seizures. Among these methods, the ones that quantify synchronization between brain areas, are the most important methods. However, to date, a practically acceptable result has not been reported. In this paper, we use a synchronization measurement method that is derived according to the ability of bi-spectrum in determining the nonlinear properties of a system. In this method, first, temporal variation of the bi-spectrum of different channels of electro cardiography (ECoG) signals are obtained via an extended wavelet-based time-frequency analysis method; then, to compare different channels, the bi-phase correlation measure is introduced. Since, in this way, the temporal variation of the amount of nonlinear coupling between brain regions, which have not been considered yet, are taken into account, results are more reliable than the conventional phase-synchronization measures. It is shown that, for 21 patients of FSPEEG database, bi-phase correlation can discriminate the pre-ictal and ictal states, with very low false positive rates (FPRs) (average: 0.078/h) and high sensitivity (100%). However, the proposed seizure predictor still cannot significantly overcome the random predictor for all patients.

X-irradiation affects all DNA replication intermediates when inhibiting replication initiation

International Nuclear Information System (INIS)

Loenn, U.; Karolinska Hospital, Stockholm

1982-01-01

When a human melanoma line was irradiated with 10 Gy, there was, after 30 to 60 min, a gradual reduction in the DNA replication rate. Ten to twelve hours after the irradiation, the DNA replication had returned to near normal rate. The results showed tht low dose-rate X-irradiation inhibits preferentially the formation of small DNA replication intermediates. There is no difference between the inhibition of these replication intermediates formed only in the irradiated cells and those formed also in untreated cells. (U.K.)

Chromatin Structure and Replication Origins: Determinants Of Chromosome Replication And Nuclear Organization

Science.gov (United States)

Smith, Owen K.; Aladjem, Mirit I.

2014-01-01

The DNA replication program is, in part, determined by the epigenetic landscape that governs local chromosome architecture and directs chromosome duplication. Replication must coordinate with other biochemical processes occurring concomitantly on chromatin, such as transcription and remodeling, to insure accurate duplication of both genetic and epigenetic features and to preserve genomic stability. The importance of genome architecture and chromatin looping in coordinating cellular processes on chromatin is illustrated by two recent sets of discoveries. First, chromatin-associated proteins that are not part of the core replication machinery were shown to affect the timing of DNA replication. These chromatin-associated proteins could be working in concert, or perhaps in competition, with the transcriptional machinery and with chromatin modifiers to determine the spatial and temporal organization of replication initiation events. Second, epigenetic interactions are mediated by DNA sequences that determine chromosomal replication. In this review we summarize recent findings and current models linking spatial and temporal regulation of the replication program with epigenetic signaling. We discuss these issues in the context of the genome’s three-dimensional structure with an emphasis on events occurring during the initiation of DNA replication. PMID:24905010

Prelife catalysts and replicators

OpenAIRE

Ohtsuki, Hisashi; Nowak, Martin A.

2009-01-01

Life is based on replication and evolution. But replication cannot be taken for granted. We must ask what there was prior to replication and evolution. How does evolution begin? We have proposed prelife as a generative system that produces information and diversity in the absence of replication. We model prelife as a binary soup of active monomers that form random polymers. ‘Prevolutionary’ dynamics can have mutation and selection prior to replication. Some sequences might have catalytic acti...

A Biphasic Calcium Sulphate/Hydroxyapatite Carrier Containing Bone Morphogenic Protein-2 and Zoledronic Acid Generates Bone

DEFF Research Database (Denmark)

Raina, Deepak Bushan; Isaksson, Hanna; Hettwer, Werner

2016-01-01

-the-shelf osteoinductive bone substitutes that can replace bone grafts are required. We tested the carrier properties of a biphasic, calcium sulphate and hydroxyapatite ceramic material, containing a combination of recombinant human bone morphogenic protein-2 (rhBMP-2) to induce bone, and zoledronic acid (ZA) to delay...

Data from Investigating Variation in Replicability: A “Many Labs” Replication Project

Directory of Open Access Journals (Sweden)

Richard A. Klein

2014-04-01

Full Text Available This dataset is from the Many Labs Replication Project in which 13 effects were replicated across 36 samples and over 6,000 participants. Data from the replications are included, along with demographic variables about the participants and contextual information about the environment in which the replication was conducted. Data were collected in-lab and online through a standardized procedure administered via an online link. The dataset is stored on the Open Science Framework website. These data could be used to further investigate the results of the included 13 effects or to study replication and generalizability more broadly.

Acute Biphasic Effects of Ayahuasca.

Science.gov (United States)

Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A; da Silveira, Dartiu Xavier

2015-01-01

Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

Acute Biphasic Effects of Ayahuasca.

Directory of Open Access Journals (Sweden)

Eduardo Ekman Schenberg

Full Text Available Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT, harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

Comparison of low-energy versus high-energy biphasic defibrillation shocks following prolonged ventricular fibrillation.

Science.gov (United States)

Walcott, Gregory P; Melnick, Sharon B; Killingsworth, Cheryl R; Ideker, Raymond E

2010-01-01

Since the initial development of the defibrillator, there has been concern that, while delivery of a large electric shock would stop fibrillation, it would also cause damage to the heart. This concern has been raised again with the development of the biphasic defibrillator. To compare defibrillation efficacy, postshock cardiac function, and troponin I levels following 150-J and 360-J shocks. Nineteen swine were anesthetized with isoflurane and instrumented with pressure catheters in the left ventricle, aorta, and right atrium. The animals were fibrillated for 6 minutes, followed by defibrillation with either low-energy (n = 8) or high-energy (n = 11) shocks. After defibrillation, chest compressions were initiated and continued until return of spontaneous circulation (ROSC). Epinephrine, 0.01 mg/kg every 3 minutes, was given for arterial blood pressure < 50 mmHg. Hemodynamic parameters were recorded for four hours. Transthoracic echocardiography was performed and troponin I levels were measured at baseline and four hours following ventricular fibrillation (VF). Survival rates at four hours were not different between the two groups (low-energy, 5 of 8; high-energy, 7 of 11). Results for arterial blood pressure, positive dP/dt (first derivative of pressure measured over time, a measure of left ventricular contractility), and negative dP/dt at the time of lowest arterial blood pressure (ABP) following ROSC were not different between the two groups (p = not significant [NS]), but were lower than at baseline. All hemodynamic measures returned to baseline by four hours. Ejection fractions, stroke volumes, and cardiac outputs were not different between the two groups at four hours. Troponin I levels at four hours were not different between the two groups (12 +/- 11 ng/mL versus 21 +/- 26 ng/mL, p = NS) but were higher at four hours than at baseline (19 +/- 19 ng/mL versus 0.8 +/- 0.5 ng/mL, p < 0.05, groups combined). Biphasic 360-J shocks do not cause more cardiac damage

Functions of Ubiquitin and SUMO in DNA Replication and Replication Stress

Science.gov (United States)

García-Rodríguez, Néstor; Wong, Ronald P.; Ulrich, Helle D.

2016-01-01

Complete and faithful duplication of its entire genetic material is one of the essential prerequisites for a proliferating cell to maintain genome stability. Yet, during replication DNA is particularly vulnerable to insults. On the one hand, lesions in replicating DNA frequently cause a stalling of the replication machinery, as most DNA polymerases cannot cope with defective templates. This situation is aggravated by the fact that strand separation in preparation for DNA synthesis prevents common repair mechanisms relying on strand complementarity, such as base and nucleotide excision repair, from working properly. On the other hand, the replication process itself subjects the DNA to a series of hazardous transformations, ranging from the exposure of single-stranded DNA to topological contortions and the generation of nicks and fragments, which all bear the risk of inducing genomic instability. Dealing with these problems requires rapid and flexible responses, for which posttranslational protein modifications that act independently of protein synthesis are particularly well suited. Hence, it is not surprising that members of the ubiquitin family, particularly ubiquitin itself and SUMO, feature prominently in controlling many of the defensive and restorative measures involved in the protection of DNA during replication. In this review we will discuss the contributions of ubiquitin and SUMO to genome maintenance specifically as they relate to DNA replication. We will consider cases where the modifiers act during regular, i.e., unperturbed stages of replication, such as initiation, fork progression, and termination, but also give an account of their functions in dealing with lesions, replication stalling and fork collapse. PMID:27242895

Temperature dependence of microwave absorption phenomena in single and biphase soft magnetic microwires

Energy Technology Data Exchange (ETDEWEB)

El Kammouni, Rhimou, E-mail: elkammounirhimou@gmail.com [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Vázquez, Manuel [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Lezama, Luis [Depto. Química Inorgánica, Universidad País Vasco, UPV/EHU, Bilbao (Spain); Kurlyandskaya, Galina [Depto. Electricidad y Electrónica, Universidad País Vasco, UPV/EHU, Bilbao (Spain); Dept. Magnetism and Magnetic Nanomaterials, Ural Federal University, Ekaterinburg (Russian Federation); Kraus, Ludek [Institute of Physics, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

2014-11-15

The microwave absorption phenomena of single and biphase magnetic microwires with soft magnetic behavior have been investigated as a function of DC applied magnetic field using two alternative techniques: (i) absorption measurements in the temperature range of 4–300 K using a spectrometer operating at X-band frequency, at 9.5 GHz, and (ii) room-temperature, RT, ferromagnetic resonance measurements in a network analyzer in the frequency range up to 20 GHz. Complementary low-frequency magnetic characterization was performed in a Vibrating Sample Magnetometer. Studies have been performed for 8 μm diameter small-magnetostriction amorphous CoFeSiB single-phase microwire, coated by micrometric Pyrex layer, and after electroplating an external shell, 2 µm or 4 µm thick, of FeNi alloys. For single phase CoFeSiB microwire, a single absorption is observed, whose DC field dependence of resonance frequency at RT fits to a Kittel-law behavior for in-plane magnetized thin film. The temperature dependence behavior shows a monotonic increase in the resonance field, H{sub r}, with temperature. A parallel reduction of the circular anisotropy field, H{sub K}, is deduced from the temperature dependence of hysteresis loops. For biphase, CoFeSiB/FeNi, microwires, the absorption phenomena at RT also follow the Kittel condition. The observed opposite evolution with temperature of resonance field, H{sub r}, in 2 and 4 µm thick FeNi samples is interpreted considering the opposite sign of magnetostriction of the respective FeNi layers. The stress-induced magnetic anisotropy field, H{sub K}, in the FeNi shell is deduced to change sign at around 130 K. - Highlights: • A single absorption phenomenon is observed for single phase CoFeSiB. • The T dependence of the microwave behavior shows a monotonic increase of H{sub r} with T. • The absorption at RT follows the Kittel condition for biphase CoFe/FeNi microwires. • The T dependence of resonant field of CoFe/FeNi is interpreted to be

NACSA Charter School Replication Guide: The Spectrum of Replication Options. Authorizing Matters. Replication Brief 1

Science.gov (United States)

O'Neill, Paul

2010-01-01

One of the most important and high-profile issues in public education reform today is the replication of successful public charter school programs. With more than 5,000 failing public schools in the United States, there is a tremendous need for strong alternatives for parents and students. Replicating successful charter school models is an…

Work Stress and Alcohol Use: Developing and Testing a Biphasic Self-Medication Model

OpenAIRE

Frone, Michael R.

2016-01-01

This study developed and tested a moderated-mediation model of work stress and alcohol use, based on the biphasic (stimulant and sedative) effects of alcohol and the self-medication and stress-vulnerability models of alcohol use. The model proposes that exposure to work stressors can increase both negative affect and work fatigue, and that these two sources of strain can subsequently motivate the use of alcohol. However, the relations of negative affect and work fatigue to a...

Use of Respiratory Support in the Biphase Ventilation Airway Mode in the Newborn

OpenAIRE

S. N. Koval; A. Ye. Kulagin

2006-01-01

Biphasic positive airway pressure (BIPAP) (also known as DuoPAP, BiLevel, BiVent, PCV+, SPAP) is a mode of ventilation with cycling variations between two continuous positive airway pressure levels. It is a mixture of pressure controlled ventilation and spontaneous breathing, which is unrestricted in each phase of the respiratory cycle. The volume displacement caused by the difference between Phigh and Plow airway pressure level. The phase time ratio (PTR — the BIPAP frequency) is calculated ...

Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons.

Science.gov (United States)

Shen, Na; Liang, Qiong; Liu, Yuehong; Lai, Bin; Li, Wen; Wang, Zhengmin; Li, Shufeng

2016-06-15

Intracochlear application of exogenous or transgenic neurotrophins, such as neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF), could promote the resprouting of spiral ganglion neuron (SGN) neurites in deafened animals. These resprouting neurites might reduce the gap between cochlear implant electrodes and their targeting SGNs, allowing for an improvement of spatial resolution of electrical stimulation. This study is to investigate the impact of electrical stimulation employed in CI on the extension of resprouting SGN neurites. We established an in vitro model including the devices delivering charge-balanced biphasic electrical stimulation, and spiral ganglion (SG) dissociated culture treated with BDNF and NT-3. After electrical stimulation with varying durations and intensities, we quantified neurite lengths and Schwann cell densities in SG cultures. Stimulations that were greater than 50μA or longer than 8h significantly decreased SG neurite length. Schwann cell density under 100μA electrical stimulation for 48h was significantly lower compared to that in non-stimulated group. These electrical stimulation-induced decreases of neurite extension and Schwann cell density were attenuated by various types of voltage-dependent calcium channel (VDCC) blockers, or completely prevented by their combination, cadmium or calcium-free medium. Our study suggested that charge-balanced biphasic electrical stimulation inhibited the extension of resprouting SGN neurites and decreased Schwann cell density in vitro. Calcium influx through multiple types of VDCCs was involved in the electrical stimulation-induced inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

DNA Replication in Engineered Escherichia coli Genomes with Extra Replication Origins.

Science.gov (United States)

Milbredt, Sarah; Farmani, Neda; Sobetzko, Patrick; Waldminghaus, Torsten

2016-10-21

The standard outline of bacterial genomes is a single circular chromosome with a single replication origin. From the bioengineering perspective, it appears attractive to extend this basic setup. Bacteria with split chromosomes or multiple replication origins have been successfully constructed in the last few years. The characteristics of these engineered strains will largely depend on the respective DNA replication patterns. However, the DNA replication has not been investigated systematically in engineered bacteria with multiple origins or split replicons. Here we fill this gap by studying a set of strains consisting of (i) E. coli strains with an extra copy of the native replication origin (oriC), (ii) E. coli strains with an extra copy of the replication origin from the secondary chromosome of Vibrio cholerae (oriII), and (iii) a strain in which the E. coli chromosome is split into two linear replicons. A combination of flow cytometry, microarray-based comparative genomic hybridization (CGH), and modeling revealed silencing of extra oriC copies and differential timing of ectopic oriII copies compared to the native oriC. The results were used to derive construction rules for future multiorigin and multireplicon projects.

Selective use of the biphasic-contrast barium enema study for evaluation of colonic lesions: Results of a prospective study

International Nuclear Information System (INIS)

De Lange, E.E.; Shaffer, H.A. Jr.; Riddervold, H.O.

1987-01-01

The authors performed a prospective study to determine the value of selective use of the biphasic contrast technique for a variety of indications. In a series of 571 double-contrast barium enema examinations, the examination was immediately followed by a single-contrast study in 85 cases. The biphasic procedure was performed to reexamine a colonic segment that was poorly evaluated initially because of diverticulosis (eta = 35), incomplete filling (eta = 28), or poor mucosal coating (eta = 26); or to verify or exclude a possible lesion identified during the double-contrast examination (eta = 22). The single-contrast study confirmed five polyps and excluded lesions in 17 cases with suspected polyps (eta = 5), strictures (eta = 4), and spasm (eta = 8). Six polyps not visualized on the double-contrast examination were detected with the single-contrast procedure

Hydroxyurea-Induced Replication Stress

Directory of Open Access Journals (Sweden)

Kenza Lahkim Bennani-Belhaj

2010-01-01

Full Text Available Bloom's syndrome (BS displays one of the strongest known correlations between chromosomal instability and a high risk of cancer at an early age. BS cells combine a reduced average fork velocity with constitutive endogenous replication stress. However, the response of BS cells to replication stress induced by hydroxyurea (HU, which strongly slows the progression of replication forks, remains unclear due to publication of conflicting results. Using two different cellular models of BS, we showed that BLM deficiency is not associated with sensitivity to HU, in terms of clonogenic survival, DSB generation, and SCE induction. We suggest that surviving BLM-deficient cells are selected on the basis of their ability to deal with an endogenous replication stress induced by replication fork slowing, resulting in insensitivity to HU-induced replication stress.

Direct transformation of xylan-type hemicelluloses to furfural via SnCl₄ catalysts in aqueous and biphasic systems.

Science.gov (United States)

Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

2015-05-01

Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120 min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enamel-based mark performance for marking Chinese mystery snail Bellamya chinensis

Science.gov (United States)

Wong, Alec; Allen, Craig R.; Hart, Noelle M.; Haak, Danielle M.; Pope, Kevin L.; Smeenk, Nicholas A.; Stephen, Bruce J.; Uden, Daniel R.

2013-01-01

The exoskeleton of gastropods provides a convenient surface for carrying marks, and i the interest of improving future marking methods our laboratory assessed the performance of an enamel paint. The endurance of the paint was also compared to other marking methods assessed in the past. We marked the shells of 30 adult Chinese mystery snails Bellamya chinensis and held them in an aquarium for 181 days. We observed no complete degradation of any enamel-paint mark during the 181 days. The enamel-paint mark was superior to a nai;-polish mark, which lasted a median of 100 days. Enamel-paint marks also have a lower rate of loss (0.00 month-1 181 days) than plastic bee tags (0.01 month-1, 57 days), gouache paint (0.07 month-1, 18.5 days), or car body paint from studies found in scientific literature. Legibility of enamel-paint marks had a median lifetime of 102 days. The use of enamel paint on the shells of gastropods is a viable option for studies lasting up to 6 months. Furthermore, visits to capture-mark-recapture site 1 year after application of enamel-paint marks on B. chinesnis shells produced several individuals on which the enamel paint was still visible, although further testing is required to clarify durability over longer periods.

A rare case of anal carcinosarcoma with human papilloma virus infection in both biphasic tumor elements: An immunohistochemical, molecular and ultrastructural study.

Science.gov (United States)

Hickman, Richard A; Bradshaw, Azore-Dee; Cassai, Nicholas; Neto, Antonio Galvao; Zhou, David; Fu, Tinghao; Lee, Peng; Pei, Zhiheng; Wieczorek, Rosemary

2016-12-01

Carcinosarcoma of the anus is rare and has yet to be reportedly associated with the keratinocyte-specific Human Papilloma Virus (HPV). We describe a case of anal carcinosarcoma with HPV infection in both the epithelial and mesenchymal components of the tumor by immunohistochemistry, chromogenic in-situ hybridization (CISH) and further supported by electron microscopy (EM). Microscopic examination of the tumor showed nests of poorly-differentiated invasive squamous cell carcinoma with basaloid features intermixed with a hypercellular, atypical spindle cell proliferation. Immunohistochemistry demonstrated that the epithelial component was positive for AE1/AE3, p63, CK5/6 and p16, whilst the mesenchymal component was positive for smooth muscle actin, vimentin, and focally positive for desmin and p16, consistent with carcinosarcoma. The tumor was negative for GATA-3, CK7 and CK20. CISH demonstrated that the tumor was positive for high risk HPV (subtype 16/18) in both tumor components. EM further supported the presence of intracellular virus particles (~50 nm) that is compatible with HPV infection. Infection of both epithelial and mesenchymal tumor components by HPV has not been previously observed in the gastrointestinal tract. This finding may represent initial epithelial HPV infection with subsequent divergent tumoral differentiation and suggests the presence of viral replication in both biphasic tumor components.

High-affinity interaction of hnRNP A1 with conserved RNA structural elements is required for translation and replication of enterovirus 71.

Science.gov (United States)

Levengood, Jeffrey D; Tolbert, Michele; Li, Mei-Ling; Tolbert, Blanton S

2013-07-01

Human Enterovirus 71 (EV71) is an emerging pathogen of infectious disease and a serious threat to public health. Currently, there are no antivirals or vaccines to slow down or prevent EV71 infections, thus underscoring the urgency to better understand mechanisms of host-enterovirus interactions. EV71 uses a type I internal ribosome entry site (IRES) to recruit the 40S ribosomal subunit via a pathway that requires the cytoplasmic localization of hnRNP A1, which acts as an IRES trans-activating factor. The mechanism of how hnRNP A1 trans activates EV71 RNA translation is unknown, however. Here, we report that the UP1 domain of hnRNP A1 interacts specifically with stem loop II (SLII) of the IRES, via a thermodynamically well-defined biphasic transition that involves conserved bulge 5'-AYAGY-3' and hairpin 5'-RY(U/A)CCA-3' loops. Calorimetric titrations of wild-type and mutant SLII constructs reveal these structural elements are essential to form a high-affinity UP1-SLII complex. Mutations that alter the bulge and hairpin primary or secondary structures abrogate the biphasic transition and destabilize the complex. Notably, mutations within the bulge that destabilize the complex correlate with a large reduction in IRES-dependent translational activity and impair EV71 replication. Taken together, this study shows that a conserved SLII structure is necessary to form a functional hnRNP A1-IRES complex, suggesting that small molecules that target this stem loop may have novel antiviral properties.

Inhibition of rotavirus replication by downregulation of fatty acid synthesis.

Science.gov (United States)

Gaunt, Eleanor R; Cheung, Winsome; Richards, James E; Lever, Andrew; Desselberger, Ulrich

2013-06-01

Recently the recruitment of lipid droplets (LDs) to sites of rotavirus (RV) replication was reported. LDs are polymorphic organelles that store triacylglycerols, cholesterol and cholesterol esters. The neutral fats are derived from palmitoyl-CoA, synthesized via the fatty acid biosynthetic pathway. RV-infected cells were treated with chemical inhibitors of the fatty acid biosynthetic pathway, and the effects on viral replication kinetics were assessed. Treatment with compound C75, an inhibitor of the fatty acid synthase enzyme complex (FASN), reduced RV infectivity 3.2-fold (P = 0.07) and modestly reduced viral RNA synthesis (1.2-fold). Acting earlier in the fatty acid synthesis pathway, TOFA [5-(Tetradecyloxy)-2-furoic acid] inhibits the enzyme acetyl-CoA carboxylase 1 (ACC1). TOFA reduced the infectivity of progeny RV 31-fold and viral RNA production 6-fold. The effect of TOFA on RV infectivity and RNA replication was dose-dependent, and infectivity was reduced by administering TOFA up to 4 h post-infection. Co-treatment of RV-infected cells with C75 and TOFA synergistically reduced viral infectivity. Knockdown by siRNA of FASN and ACC1 produced findings similar to those observed by inhibiting these proteins with the chemical compounds. Inhibition of fatty acid synthesis using a range of approaches uniformly had a more marked impact on viral infectivity than on viral RNA yield, inferring a role for LDs in virus assembly and/or egress. Specific inhibitors of fatty acid metabolism may help pinpoint the critical structural and biochemical features of LDs that are essential for RV replication, and facilitate the development of antiviral therapies.

Replicating animal mitochondrial DNA

Directory of Open Access Journals (Sweden)

Emily A. McKinney

2013-01-01

Full Text Available The field of mitochondrial DNA (mtDNA replication has been experiencing incredible progress in recent years, and yet little is certain about the mechanism(s used by animal cells to replicate this plasmid-like genome. The long-standing strand-displacement model of mammalian mtDNA replication (for which single-stranded DNA intermediates are a hallmark has been intensively challenged by a new set of data, which suggests that replication proceeds via coupled leading-and lagging-strand synthesis (resembling bacterial genome replication and/or via long stretches of RNA intermediates laid on the mtDNA lagging-strand (the so called RITOLS. The set of proteins required for mtDNA replication is small and includes the catalytic and accessory subunits of DNA polymerase y, the mtDNA helicase Twinkle, the mitochondrial single-stranded DNA-binding protein, and the mitochondrial RNA polymerase (which most likely functions as the mtDNA primase. Mutations in the genes coding for the first three proteins are associated with human diseases and premature aging, justifying the research interest in the genetic, biochemical and structural properties of the mtDNA replication machinery. Here we summarize these properties and discuss the current models of mtDNA replication in animal cells.

Progranulin haploinsufficiency causes biphasic social dominance abnormalities in the tube test.

Science.gov (United States)

Arrant, A E; Filiano, A J; Warmus, B A; Hall, A M; Roberson, E D

2016-07-01

Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia (FTD), a neurodegenerative disorder in which social behavior is disrupted. Progranulin-insufficient mice, both Grn(+/-) and Grn(-/-) , are used as models of FTD due to GRN mutations, with Grn(+/-) mice mimicking the progranulin haploinsufficiency of FTD patients with GRN mutations. Grn(+/-) mice have increased social dominance in the tube test at 6 months of age, although this phenotype has not been reported in Grn(-/-) mice. In this study, we investigated how the tube test phenotype of progranulin-insufficient mice changes with age, determined its robustness under several testing conditions, and explored the associated cellular mechanisms. We observed biphasic social dominance abnormalities in Grn(+/-) mice: at 6-8 months, Grn(+/-) mice were more dominant than wild-type littermates, while after 9 months of age, Grn(+/-) mice were less dominant. In contrast, Grn(-/-) mice did not exhibit abnormal social dominance, suggesting that progranulin haploinsufficiency has distinct effects from complete progranulin deficiency. The biphasic tube test phenotype of Grn(+/-) mice was associated with abnormal cellular signaling and neuronal morphology in the amygdala and prefrontal cortex. At 6-9 months, Grn(+/-) mice exhibited increased mTORC2/Akt signaling in the amygdala and enhanced dendritic arbors in the basomedial amygdala, and at 9-16 months Grn(+/-) mice exhibited diminished basal dendritic arbors in the prelimbic cortex. These data show a progressive change in tube test dominance in Grn(+/-) mice and highlight potential underlying mechanisms by which progranulin insufficiency may disrupt social behavior. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Effect of deoxyribonucleic acid replication inhibitors on bacterial recombination

International Nuclear Information System (INIS)

Canosi, U.; Siccardi, A.G.; Falaschi, A.; Mazza, G.

1976-01-01

Two inhibitors of replicative deoxyribonucleic acid (DNA) synthesis, nalidixic acid (NAL) and 6-(p-hydroxyphenylazo)-uracil (HPUra), showed different effects on genetic recombination and DNA repair in Bacillus subtilis. Previous work (Pedrini et al., 1972) showed that NAL does not interfere with the transformation process of B. subtilis. The results reported in this work demonstrated that the drug was also without effect on the transfection SPP1 or SPO-1 phage DNA (a process that requires a recombination event). The drug was also ineffective on the host cell reactivation of ultraviolet-irradiated SPP1 phage, as well as on transfection with ultraviolet-irradiated DNA of the same phage. HPUra instead markedly reduced the transformation process, as well as transfection, by SPO-1 DNA, but it did not affect the host cell reactivation of SPO-1 phage. In conclusion, whereas the NAL target seems to be specific for replicative DNA synthesis, the HPUra target (i.e., the DNA polymerase III of B. subtilis) seems to be involved also in recombination, but not in the excision repair process. The mutations conferring NAL and HPUra resistance used in this work were mapped by PBS-1 transduction

Chromatin Controls DNA Replication Origin Selection, Lagging-Strand Synthesis, and Replication Fork Rates.

Science.gov (United States)

Kurat, Christoph F; Yeeles, Joseph T P; Patel, Harshil; Early, Anne; Diffley, John F X

2017-01-05

The integrity of eukaryotic genomes requires rapid and regulated chromatin replication. How this is accomplished is still poorly understood. Using purified yeast replication proteins and fully chromatinized templates, we have reconstituted this process in vitro. We show that chromatin enforces DNA replication origin specificity by preventing non-specific MCM helicase loading. Helicase activation occurs efficiently in the context of chromatin, but subsequent replisome progression requires the histone chaperone FACT (facilitates chromatin transcription). The FACT-associated Nhp6 protein, the nucleosome remodelers INO80 or ISW1A, and the lysine acetyltransferases Gcn5 and Esa1 each contribute separately to maximum DNA synthesis rates. Chromatin promotes the regular priming of lagging-strand DNA synthesis by facilitating DNA polymerase α function at replication forks. Finally, nucleosomes disrupted during replication are efficiently re-assembled into regular arrays on nascent DNA. Our work defines the minimum requirements for chromatin replication in vitro and shows how multiple chromatin factors might modulate replication fork rates in vivo. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Modeling inhomogeneous DNA replication kinetics.

Directory of Open Access Journals (Sweden)

Michel G Gauthier

Full Text Available In eukaryotic organisms, DNA replication is initiated at a series of chromosomal locations called origins, where replication forks are assembled proceeding bidirectionally to replicate the genome. The distribution and firing rate of these origins, in conjunction with the velocity at which forks progress, dictate the program of the replication process. Previous attempts at modeling DNA replication in eukaryotes have focused on cases where the firing rate and the velocity of replication forks are homogeneous, or uniform, across the genome. However, it is now known that there are large variations in origin activity along the genome and variations in fork velocities can also take place. Here, we generalize previous approaches to modeling replication, to allow for arbitrary spatial variation of initiation rates and fork velocities. We derive rate equations for left- and right-moving forks and for replication probability over time that can be solved numerically to obtain the mean-field replication program. This method accurately reproduces the results of DNA replication simulation. We also successfully adapted our approach to the inverse problem of fitting measurements of DNA replication performed on single DNA molecules. Since such measurements are performed on specified portion of the genome, the examined DNA molecules may be replicated by forks that originate either within the studied molecule or outside of it. This problem was solved by using an effective flux of incoming replication forks at the model boundaries to represent the origin activity outside the studied region. Using this approach, we show that reliable inferences can be made about the replication of specific portions of the genome even if the amount of data that can be obtained from single-molecule experiments is generally limited.

Mechanisms of DNA replication termination.

Science.gov (United States)

Dewar, James M; Walter, Johannes C

2017-08-01

Genome duplication is carried out by pairs of replication forks that assemble at origins of replication and then move in opposite directions. DNA replication ends when converging replication forks meet. During this process, which is known as replication termination, DNA synthesis is completed, the replication machinery is disassembled and daughter molecules are resolved. In this Review, we outline the steps that are likely to be common to replication termination in most organisms, namely, fork convergence, synthesis completion, replisome disassembly and decatenation. We briefly review the mechanism of termination in the bacterium Escherichia coli and in simian virus 40 (SV40) and also focus on recent advances in eukaryotic replication termination. In particular, we discuss the recently discovered E3 ubiquitin ligases that control replisome disassembly in yeast and higher eukaryotes, and how their activity is regulated to avoid genome instability.

Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling.

Directory of Open Access Journals (Sweden)

Robert D Prinz

Full Text Available The glycosaminoglycan chondroitin sulfate is a critical component of proteoglycans on the cell surface and in the extracellular matrix. As such, chondroitin sulfate side chains and the sulfation balance of chondroitin play important roles in the control of signaling pathways, and have a functional importance in human disease. In contrast, very little is known about the roles of chondroitin sulfate molecules and sulfation patterns during mammalian development and cell lineage specification. Here, we report a novel biphasic role of chondroitin sulfate in the specification of the cardiac cell lineage during embryonic stem cell differentiation through modulation of Wnt/beta-catenin signaling. Lineage marker analysis demonstrates that enzymatic elimination of endogenous chondroitin sulfates leads to defects specifically in cardiac differentiation. This is accompanied by a reduction in the number of beating cardiac foci. Mechanistically, we show that endogenous chondroitin sulfate controls cardiac differentiation in a temporal biphasic manner through inhibition of the Wnt/beta-catenin pathway, a known regulatory pathway for the cardiac lineage. Treatment with a specific exogenous chondroitin sulfate, CS-E, could mimic these biphasic effects on cardiac differentiation and Wnt/beta-catenin signaling. These results establish chondroitin sulfate and its sulfation balance as important regulators of cardiac cell lineage decisions through control of the Wnt/beta-catenin pathway. Our work suggests that targeting the chondroitin biosynthesis and sulfation machinery is a novel promising avenue in regenerative strategies after heart injury.

Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling.

Science.gov (United States)

Prinz, Robert D; Willis, Catherine M; van Kuppevelt, Toin H; Klüppel, Michael

2014-01-01

The glycosaminoglycan chondroitin sulfate is a critical component of proteoglycans on the cell surface and in the extracellular matrix. As such, chondroitin sulfate side chains and the sulfation balance of chondroitin play important roles in the control of signaling pathways, and have a functional importance in human disease. In contrast, very little is known about the roles of chondroitin sulfate molecules and sulfation patterns during mammalian development and cell lineage specification. Here, we report a novel biphasic role of chondroitin sulfate in the specification of the cardiac cell lineage during embryonic stem cell differentiation through modulation of Wnt/beta-catenin signaling. Lineage marker analysis demonstrates that enzymatic elimination of endogenous chondroitin sulfates leads to defects specifically in cardiac differentiation. This is accompanied by a reduction in the number of beating cardiac foci. Mechanistically, we show that endogenous chondroitin sulfate controls cardiac differentiation in a temporal biphasic manner through inhibition of the Wnt/beta-catenin pathway, a known regulatory pathway for the cardiac lineage. Treatment with a specific exogenous chondroitin sulfate, CS-E, could mimic these biphasic effects on cardiac differentiation and Wnt/beta-catenin signaling. These results establish chondroitin sulfate and its sulfation balance as important regulators of cardiac cell lineage decisions through control of the Wnt/beta-catenin pathway. Our work suggests that targeting the chondroitin biosynthesis and sulfation machinery is a novel promising avenue in regenerative strategies after heart injury.

Rolling replication of UV-irradiated duplex DNA in the phi X174 replicative-form----single-strand replication system in vitro

International Nuclear Information System (INIS)

Shavitt, O.; Livneh, Z.

1989-01-01

Cloning of the phi X174 viral origin of replication into phage M13mp8 produced an M13-phi X174 chimera, the DNA of which directed efficient replicative-form----single-strand rolling replication in vitro. This replication assay was performed with purified phi X174-encoded gene A protein, Escherichia coli rep helicase, single-stranded DNA-binding protein, and DNA polymerase III holoenzyme. The nicking of replicative-form I (RFI) DNA by gene A protein was essentially unaffected by the presence of UV lesions in the DNA. However, unwinding of UV-irradiated DNA by the rep helicase was inhibited twofold as compared with unwinding of the unirradiated substrate. UV irradiation of the substrate DNA caused a strong inhibition in its ability to direct DNA synthesis. However, even DNA preparations that contained as many as 10 photodimers per molecule still supported the synthesis of progeny full-length single-stranded DNA. The appearance of full-length radiolabeled products implied at least two full rounds of replication, since the first round released the unlabeled plus viral strand of the duplex DNA. Pretreatment of the UV-irradiated DNA substrate with purified pyrimidine dimer endonuclease from Micrococcus luteus, which converted photodimer-containing supercoiled RFI DNA into relaxed, nicked RFII DNA and thus prevented its replication, reduced DNA synthesis by 70%. Analysis of radiolabeled replication products by agarose gel electrophoresis followed by autoradiography revealed that this decrease was due to a reduction in the synthesis of progeny full-length single-stranded DNA. This implies that 70 to 80% of the full-length DNA products produced in this system were synthesized on molecules that carried photodimers

Mammalian RAD52 Functions in Break-Induced Replication Repair of Collapsed DNA Replication Forks

DEFF Research Database (Denmark)

Sotiriou, Sotirios K; Kamileri, Irene; Lugli, Natalia

2016-01-01

Human cancers are characterized by the presence of oncogene-induced DNA replication stress (DRS), making them dependent on repair pathways such as break-induced replication (BIR) for damaged DNA replication forks. To better understand BIR, we performed a targeted siRNA screen for genes whose...... RAD52 facilitates repair of collapsed DNA replication forks in cancer cells....

REPLICATION TOOL AND METHOD OF PROVIDING A REPLICATION TOOL

DEFF Research Database (Denmark)

2016-01-01

The invention relates to a replication tool (1, 1a, 1b) for producing a part (4) with a microscale textured replica surface (5a, 5b, 5c, 5d). The replication tool (1, 1a, 1b) comprises a tool surface (2a, 2b) defining a general shape of the item. The tool surface (2a, 2b) comprises a microscale...... energy directors on flange portions thereof uses the replication tool (1, 1a, 1b) to form an item (4) with a general shape as defined by the tool surface (2a, 2b). The formed item (4) comprises a microscale textured replica surface (5a, 5b, 5c, 5d) with a lateral arrangement of polydisperse microscale...

Recommendations for Replication Research in Special Education: A Framework of Systematic, Conceptual Replications

Science.gov (United States)

Coyne, Michael D.; Cook, Bryan G.; Therrien, William J.

2016-01-01

Special education researchers conduct studies that can be considered replications. However, they do not often refer to them as replication studies. The purpose of this article is to consider the potential benefits of conceptualizing special education intervention research within a framework of systematic, conceptual replication. Specifically, we…

DNA replication and cancer

DEFF Research Database (Denmark)

Boyer, Anne-Sophie; Walter, David; Sørensen, Claus Storgaard

2016-01-01

A dividing cell has to duplicate its DNA precisely once during the cell cycle to preserve genome integrity avoiding the accumulation of genetic aberrations that promote diseases such as cancer. A large number of endogenous impacts can challenge DNA replication and cells harbor a battery of pathways...... causing DNA replication stress and genome instability. Further, we describe cellular and systemic responses to these insults with a focus on DNA replication restart pathways. Finally, we discuss the therapeutic potential of exploiting intrinsic replicative stress in cancer cells for targeted therapy....

Late-replicating X-chromosome: replication patterns in mammalian females

Directory of Open Access Journals (Sweden)

Tunin Karen

2002-01-01

Full Text Available The GTG-banding and 5-BrdU incorporation patterns of the late-replicating X-chromosome were studied in female dogs and cattle, and compared to human female patterns. The replication patterns of the short arm of the X-chromosomes did not show any difference between human, dog and cattle females. As to the long arm, some bands showed differences among the three studied species regarding the replication kinetics pattern. These differences were observed in a restricted region of the X-chromosome, delimited by Xq11 -> q25 in humans, by Xq1 -> q8 in dogs, and by Xq12 -> q32 in cattle. In an attempt to find out if these differences in the replication kinetics could be a reflection of differences in the localization of genes in that region of the X-chromosome, we used the probe for the human androgen receptor gene (AR localized at Xq12, which is in the region where we observed differences among the three studied species. We did not, however, observe hybridization signals. Our study goes on, using other human probes for genes located in the region Xq11 -> Xq25.

Development of Modified-Release Tablets of Zolpidem Tartrate by Biphasic Quick/Slow Delivery System

OpenAIRE

Mahapatra, Anjan Kumar; Sameeraja, N. H.; Murthy, P. N.

2014-01-01

Zolpidem tartrate is a non-benzodiazepine analogue of imidazopyridine of sedative and hypnotic category. It has a short half-life with usual dosage regimen being 5 mg, two times a day, or 10 mg, once daily. The duration of action is considered too short in certain circumstances. Thus, it is desirable to lengthen the duration of action. The formulation design was implemented by preparing extended-release tablets of zolpidem tartrate using the biphasic delivery system technology, where sodium s...

Electrochemical assessment of water|ionic liquid biphasic systems towards cesium extraction from nuclear waste

OpenAIRE

Stockmann, T. Jane; Zhang, Jing; Montgomery, Anne-Marie; Ding, Zhifeng

2014-01-01

A room temperature ionic liquid (IL) composed of a quaternary alkylphosphonium (trihexyltetradecylphosphonium, P66614(+)) and tetrakis(pentafluorophenyl) borate anion (TB) was employed within a water| P66614TB (w|P66614TB or w|IL) biphasic system to evaluate cesium ion extraction in comparison to that with a traditional water|organic solvent (w|o) combination. Cs-137 is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is th...

A Replication by Any Other Name: A Systematic Review of Replicative Intervention Studies

Science.gov (United States)

Cook, Bryan G.; Collins, Lauren W.; Cook, Sara C.; Cook, Lysandra

2016-01-01

Replication research is essential to scientific knowledge. Reviews of replication studies often electronically search for "replicat*" as a textword, which does not identify studies that replicate previous research but do not self-identify as such. We examined whether the 83 intervention studies published in six non-categorical research…

Registered Replication Report

DEFF Research Database (Denmark)

Bouwmeester, S.; Verkoeijen, P. P.J.L.; Aczel, B.

2017-01-01

and colleagues. The results of studies using time pressure have been mixed, with some replication attempts observing similar patterns (e.g., Rand et al., 2014) and others observing null effects (e.g., Tinghög et al., 2013; Verkoeijen & Bouwmeester, 2014). This Registered Replication Report (RRR) assessed...... the size and variability of the effect of time pressure on cooperative decisions by combining 21 separate, preregistered replications of the critical conditions from Study 7 of the original article (Rand et al., 2012). The primary planned analysis used data from all participants who were randomly assigned...

International Expansion through Flexible Replication

DEFF Research Database (Denmark)

Jonsson, Anna; Foss, Nicolai Juul

2011-01-01

Business organizations may expand internationally by replicating a part of their value chain, such as a sales and marketing format, in other countries. However, little is known regarding how such “international replicators” build a format for replication, or how they can adjust it in order to ada......, etc.) are replicated in a uniform manner across stores, and change only very slowly (if at all) in response to learning (“flexible replication”). We conclude by discussing the factors that influence the approach to replication adopted by an international replicator.......Business organizations may expand internationally by replicating a part of their value chain, such as a sales and marketing format, in other countries. However, little is known regarding how such “international replicators” build a format for replication, or how they can adjust it in order to adapt...

Sterol Binding by the Tombusviral Replication Proteins Is Essential for Replication in Yeast and Plants.

Science.gov (United States)

Xu, Kai; Nagy, Peter D

2017-04-01

Membranous structures derived from various organelles are important for replication of plus-stranded RNA viruses. Although the important roles of co-opted host proteins in RNA virus replication have been appreciated for a decade, the equally important functions of cellular lipids in virus replication have been gaining full attention only recently. Previous work with Tomato bushy stunt tombusvirus (TBSV) in model host yeast has revealed essential roles for phosphatidylethanolamine and sterols in viral replication. To further our understanding of the role of sterols in tombusvirus replication, in this work we showed that the TBSV p33 and p92 replication proteins could bind to sterols in vitro The sterol binding by p33 is supported by cholesterol recognition/interaction amino acid consensus (CRAC) and CARC-like sequences within the two transmembrane domains of p33. Mutagenesis of the critical Y amino acids within the CRAC and CARC sequences blocked TBSV replication in yeast and plant cells. We also showed the enrichment of sterols in the detergent-resistant membrane (DRM) fractions obtained from yeast and plant cells replicating TBSV. The DRMs could support viral RNA synthesis on both the endogenous and exogenous templates. A lipidomic approach showed the lack of enhancement of sterol levels in yeast and plant cells replicating TBSV. The data support the notion that the TBSV replication proteins are associated with sterol-rich detergent-resistant membranes in yeast and plant cells. Together, the results obtained in this study and the previously published results support the local enrichment of sterols around the viral replication proteins that is critical for TBSV replication. IMPORTANCE One intriguing aspect of viral infections is their dependence on efficient subcellular assembly platforms serving replication, virion assembly, or virus egress via budding out of infected cells. These assembly platforms might involve sterol-rich membrane microdomains, which are

Induction of bone formation by smart biphasic hydroxyapatite tricalcium phosphate biomimetic matrices in the non-human primate Papio ursinus

CSIR Research Space (South Africa)

Ripamonti, U

2008-01-01

Full Text Available Long-term studies in the non-human primate Chacma baboon Papio ursinus were set to investigate the induction of bone formation by biphasic hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) biomimetic matrices. HA/β-TCP biomimetic matrices in a pre...

Fabrication of nano structural biphasic materials from phosphogypsum waste and their in vitro applications

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Khaled R., E-mail: Kh_rezk966@yahoo.com [Biomaterials Department, National Research Centre, Dokki, Cairo (Egypt); Mousa, Sahar M. [Chemistry Department, Science and Art College, King Abdulaziz University, Rabigh Campus, P.O. Box 344, 21911 Rabigh (Saudi Arabia); Inorganic Chemistry Department, National Research Centre, Dokki, P.O. Box 12622, 11787 Cairo (Egypt); El Bassyouni, Gehan T. [Biomaterials Department, National Research Centre, Dokki, Cairo (Egypt); Medical Physics Department, College of Medicine, Taif University (Saudi Arabia)

2014-02-01

Graphical abstract: (a) Schema of the process, (b) TEM of nano particles of biphasic materials and (c) SEM of post-immersion. - Highlights: • Ratio of HA and β-TCP phases were controlled by thermal treatment. • HA partially decomposed into β-TCP with other bioactive phases. • Calcined HA at 900 °C is the best for the bioactivity behavior. - Abstract: In this study, a novel process of preparing biphasic calcium phosphate (BCP) is proposed. Also its bioactivity for the utilization of the prepared BCP as a biomaterial is studied. A mixture of calcium hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) could be obtained by thermal treatment of HAP which was previously prepared from phosphogypsum (PG) waste. The chemical and phase composition, morphology and particle size of prepared samples was characterized by X-ray diffraction (XRD), Infrared spectroscopy (IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The bioactivity was investigated by soaking of the calcined samples in simulated body fluid (SBF). Results confirmed that the calcination temperatures played an important role in the formation of calcium phosphate (CP) materials. XRD results indicated that HAP was partially decomposed into β-TCP. The in vitro data confirmed that the calcined HAP forming BCP besides other phases such as pyrophosphate and silica are bioactive materials. Therefore, BCP will be used as good biomaterials for medical applications.

Biphasic electrical currents stimulation promotes both proliferation and differentiation of fetal neural stem cells.

Directory of Open Access Journals (Sweden)

Keun-A Chang

2011-04-01

Full Text Available The use of non-chemical methods to differentiate stem cells has attracted researchers from multiple disciplines, including the engineering and the biomedical fields. No doubt, growth factor based methods are still the most dominant of achieving some level of proliferation and differentiation control--however, chemical based methods are still limited by the quality, source, and amount of the utilized reagents. Well-defined non-chemical methods to differentiate stem cells allow stem cell scientists to control stem cell biology by precisely administering the pre-defined parameters, whether they are structural cues, substrate stiffness, or in the form of current flow. We have developed a culture system that allows normal stem cell growth and the option of applying continuous and defined levels of electric current to alter the cell biology of growing cells. This biphasic current stimulator chip employing ITO electrodes generates both positive and negative currents in the same culture chamber without affecting surface chemistry. We found that biphasic electrical currents (BECs significantly increased the proliferation of fetal neural stem cells (NSCs. Furthermore, BECs also promoted the differentiation of fetal NSCs into neuronal cells, as assessed using immunocytochemistry. Our results clearly show that BECs promote both the proliferation and neuronal differentiation of fetal NSCs. It may apply to the development of strategies that employ NSCs in the treatment of various neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases.

Catalytic conversion of corncob and corncob pretreatment hydrolysate to furfural in a biphasic system with addition of sodium chloride.

Science.gov (United States)

Qing, Qing; Guo, Qi; Zhou, Linlin; Wan, Yilun; Xu, Youqing; Ji, Huilong; Gao, Xiaohang; Zhang, Yue

2017-02-01

Catalytic conversion of corncob pretreatment hydrolysate and raw corncob into furfural in a modified biphasic system by SO 4 2- /SnO 2 - MMT solid catalyst has been developed. The influence of the organic solvent type, organic to water phase ratio, sodium chloride concentration, reaction temperature and time on the furfural production were comparatively evaluated. The results showed that furfural yields of 81.7% and 66.1% were achieved at 190°C for 15mins and 190°C for 20mins, respectively, for corncob pretreatment hydrolysate and raw corncob by this solid catalyst. The solid catalyst used in this study exhibited good stability and high efficiency applied in the modified biphasic system in addition to excellent recyclability. The proposed catalytic system displayed high performance for catalytic conversion of lignocellulosic biomass into important platform chemicals and has great potential in industrial application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mcm10 regulates DNA replication elongation by stimulating the CMG replicative helicase.

Science.gov (United States)

Lõoke, Marko; Maloney, Michael F; Bell, Stephen P

2017-02-01

Activation of the Mcm2-7 replicative DNA helicase is the committed step in eukaryotic DNA replication initiation. Although Mcm2-7 activation requires binding of the helicase-activating proteins Cdc45 and GINS (forming the CMG complex), an additional protein, Mcm10, drives initial origin DNA unwinding by an unknown mechanism. We show that Mcm10 binds a conserved motif located between the oligonucleotide/oligosaccharide fold (OB-fold) and A subdomain of Mcm2. Although buried in the interface between these domains in Mcm2-7 structures, mutations predicted to separate the domains and expose this motif restore growth to conditional-lethal MCM10 mutant cells. We found that, in addition to stimulating initial DNA unwinding, Mcm10 stabilizes Cdc45 and GINS association with Mcm2-7 and stimulates replication elongation in vivo and in vitro. Furthermore, we identified a lethal allele of MCM10 that stimulates initial DNA unwinding but is defective in replication elongation and CMG binding. Our findings expand the roles of Mcm10 during DNA replication and suggest a new model for Mcm10 function as an activator of the CMG complex throughout DNA replication. © 2017 Lõoke et al.; Published by Cold Spring Harbor Laboratory Press.

Trophic Ecology of Benthic Marine Invertebrates with Bi-Phasic Life Cycles: What Are We Still Missing?

Science.gov (United States)

Calado, Ricardo; Leal, Miguel Costa

2015-01-01

The study of trophic ecology of benthic marine invertebrates with bi-phasic life cycles is critical to understand the mechanisms shaping population dynamics. Moreover, global climate change is impacting the marine environment at an unprecedented level, which promotes trophic mismatches that affect the phenology of these species and, ultimately, act as drivers of ecological and evolutionary change. Assessing the trophic ecology of marine invertebrates is critical to understanding maternal investment, larval survival to metamorphosis, post-metamorphic performance, resource partitioning and trophic cascades. Tools already available to assess the trophic ecology of marine invertebrates, including visual observation, gut content analysis, food concentration, trophic markers, stable isotopes and molecular genetics, are reviewed and their main advantages and disadvantages for qualitative and quantitative approaches are discussed. The challenges to perform the partitioning of ingestion, digestion and assimilation are discussed together with different approaches to address each of these processes for short- and long-term fingerprinting. Future directions for research on the trophic ecology of benthic marine invertebrates with bi-phasic life cycles are discussed with emphasis on five guidelines that will allow for systematic study and comparative meta-analysis to address important unresolved questions. © 2015 Elsevier Ltd. All rights reserved.

Injectable glycosaminoglycan-protein nano-complex in semi-interpenetrating networks: A biphasic hydrogel for hyaline cartilage regeneration.

Science.gov (United States)

Radhakrishnan, Janani; Subramanian, Anuradha; Sethuraman, Swaminathan

2017-11-01

Articular hyaline cartilage regeneration remains challenging due to its less intrinsic reparability. The study develops injectable biphasic semi-interpenetrating polymer networks (SIPN) hydrogel impregnated with chondroitin sulfate (ChS) nanoparticles for functional cartilage restoration. ChS loaded zein nanoparticles (∼150nm) prepared by polyelectrolyte-protein complexation were interspersed into injectable SIPNs developed by blending alginate with poly(vinyl alcohol) and calcium crosslinking. The hydrogel exhibited interconnected porous microstructure (39.9±5.8μm pore diameter, 57.7±5.9% porosity), 92% swellability and >350Pa elastic modulus. Primary chondrocytes compatibility, chondrocyte-matrix interaction with cell-cell clustering and spheroidal morphology was demonstrated in ChS loaded hydrogel and long-term (42days) proliferation was also determined. Higher fold expression of cartilage-specific genes sox9, aggrecan and collagen-II was observed in ChS loaded hydrogel while exhibiting poor expression of collagen-I. Immunoblotting of aggregan and collagen II demonstrate favorable positive influence of ChS on chondrocytes. Thus, the injectable biphasic SIPNs could be promising composition-mimetic substitute for cartilage restoration at irregular defects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low temperature N,N-dimethylformamide-assisted synthesis and characterization of anatase-rutile biphasic nanostructured titania

Energy Technology Data Exchange (ETDEWEB)

Estruga, M; Domenech, X; Ayllon, J A [Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB, E-08193 Bellaterra (Spain); Domingo, C [Institut de Ciencia dels Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra (Spain)], E-mail: joseantonio.ayllon@uab.es, E-mail: mestruga@qf.uab.cat

2009-03-25

Anatase and rutile biphasic nanostructured titania (TiO{sub 2}) has been synthesized via hydrolysis of titanium tetraisopropoxide in an aqueous solution of hydrobromic acid (HBr) and N,N-dimethylformamide (DMF) at 80 deg. C for 16 h. The presence of DMF, which was partially hydrolyzed during the process, determined the formation of a biphasic material. Powder x-ray diffraction showed the presence of both anatase and rutile titania phases in a ratio of approx. 1:1. Transmission electron microscope analysis showed that rutile was present as radial flower-like nanorods, which were surrounded by anatase spherical nanoparticles of 5 nm diameter. Low temperature nitrogen adsorption-desorption analysis showed the characteristic hysteresis loop of a mesoporous material. Specific surface area reached a value of 120 m{sup 2} g{sup -1} and the average pore diameter was 50 A. X-ray photoelectron spectroscopic analysis revealed that interstitial nitrogen was incorporated (0.35 at.%) during the annealing process. According to ultraviolet (UV)-visible diffuse reflectance spectroscope characterization, the N-doping caused a bandgap reduction from 3.0 to 2.9 eV. Photocatalytic activity of the material was tested for the degradation of methylene blue, methyl orange and 4-nitrophenol under near-UV and visible light radiation.

COMPUTER HARDWARE MARKING

CERN Multimedia

Groupe de protection des biens

2000-01-01

As part of the campaign to protect CERN property and for insurance reasons, all computer hardware belonging to the Organization must be marked with the words 'PROPRIETE CERN'.IT Division has recently introduced a new marking system that is both economical and easy to use. From now on all desktop hardware (PCs, Macintoshes, printers) issued by IT Division with a value equal to or exceeding 500 CHF will be marked using this new system.For equipment that is already installed but not yet marked, including UNIX workstations and X terminals, IT Division's Desktop Support Service offers the following services free of charge:Equipment-marking wherever the Service is called out to perform other work (please submit all work requests to the IT Helpdesk on 78888 or helpdesk@cern.ch; for unavoidable operational reasons, the Desktop Support Service will only respond to marking requests when these coincide with requests for other work such as repairs, system upgrades, etc.);Training of personnel designated by Division Leade...

Biphasic 201thallium scintgraphy after dipyridamole in mitral valve diseases

International Nuclear Information System (INIS)

Schmoliner, R.; Dudczak, R.; Kronik, G.; Moesslacher, H.; Kletter, K.; Frischauf, H.

1980-01-01

The results of biphasic 201 thallium scintigraphy after dipyridamole i.v. could neither prove nor exclude the presence of small focal lesions in the myocardium of 17 patients with mitral valve diseases. The frequent finding of a decrease in activity in the anterolateral myocardium is probably due to a relative increase in activity in the region of the inferior wall with superimposed areas of the papillary muscle and right ventricular myocardium. If the right ventricle is visualized in stress- or redistribution images, an increase in mean pulmonary artery pressure can be accepted. According to Cohen's criteria, a grade 2 or 3 virtually proves the existence of pulmonary hypertension, a grade 1 makes this finding rather probable. The possibility of pulmonary hypertension can not be excluded if the right ventricular myocardium is not visualized. (orig.) [de

Genetic exchanges caused by ultraviolet photoproducts in phage lamda DNA molecules: the role of DNA replication

International Nuclear Information System (INIS)

Lin, P.F.; Howard-Flanders, P.; Yale Univ., New Haven, Conn.

1976-01-01

Genetic recombination induced by structural damage in DNA molecules was investigated in E. coli K12(lamda) lysogens infected with genetically marked phage lamda. Photoproducts were induced in the phage DNA before infection by exposing them either to 313 nm light in the presence of acetophenone or to 254 nm light. To test the role of the replication of the damage phage DNA on the frequency of the induced recombination , both heteroimmune and homoimmune crosses were performed, and scored for P + recombinants. In heteroimmune crosses, recombination was less frequent in infected cells exposed to visible light and in wild type cells able to perform excision repair than in excision-defective lysogens. Therefore, much of the induced recombination can be attributed to the pyrimidine dimers in the phage DNA. In homoimmune crosses, replication of the phage DNA containing ultraviolet photoproducts was represented by lamda immunity, and was further blocked by the lack of the P gene product needed for replication. The 254 nm photoproducts increased the frequency of recombination in these homoimmune crosses, even though phage DNA replication was blocked. Irradiation with 313 nm light and acetophenone M, which produces dimers and unknown photoproducts, was not as effective per dimer as the 254 nm light. It is concluded from these results that certain unidentified 254 nm photoproducts can cause recombination even in the absence of DNA replication. They are not pyrimidine dimers, as they are not susceptible to excision repair or photoreactivation. In contrast, pyrimidine dimers appear to cause recombination only when the DNA containing them undergoes replication. (orig./MG) [de

INVESTIGATION OF AQUEOUS BIPHASIC SYSTEMS FOR THE SEPARATIONS OF LIGNINS FROM CELLULOSE IN THE PAPER PULPING PROCESS. (R826732)

Science.gov (United States)

In efforts to apply a polymer-based aqueous biphasic system (ABS) extraction to the paper pulping process, the study of the distribution of various lignin and cellulosic fractions in ABS and the effects of temperature on system composition and solute partitioning have been inv...

Who Needs Replication?

Science.gov (United States)

Porte, Graeme

2013-01-01

In this paper, the editor of a recent Cambridge University Press book on research methods discusses replicating previous key studies to throw more light on their reliability and generalizability. Replication research is presented as an accepted method of validating previous research by providing comparability between the original and replicated…

Methylation of DNA Ligase 1 by G9a/GLP Recruits UHRF1 to Replicating DNA and Regulates DNA Methylation.

Science.gov (United States)

Ferry, Laure; Fournier, Alexandra; Tsusaka, Takeshi; Adelmant, Guillaume; Shimazu, Tadahiro; Matano, Shohei; Kirsh, Olivier; Amouroux, Rachel; Dohmae, Naoshi; Suzuki, Takehiro; Filion, Guillaume J; Deng, Wen; de Dieuleveult, Maud; Fritsch, Lauriane; Kudithipudi, Srikanth; Jeltsch, Albert; Leonhardt, Heinrich; Hajkova, Petra; Marto, Jarrod A; Arita, Kyohei; Shinkai, Yoichi; Defossez, Pierre-Antoine

2017-08-17

DNA methylation is an essential epigenetic mark in mammals that has to be re-established after each round of DNA replication. The protein UHRF1 is essential for this process; it has been proposed that the protein targets newly replicated DNA by cooperatively binding hemi-methylated DNA and H3K9me2/3, but this model leaves a number of questions unanswered. Here, we present evidence for a direct recruitment of UHRF1 by the replication machinery via DNA ligase 1 (LIG1). A histone H3K9-like mimic within LIG1 is methylated by G9a and GLP and, compared with H3K9me2/3, more avidly binds UHRF1. Interaction with methylated LIG1 promotes the recruitment of UHRF1 to DNA replication sites and is required for DNA methylation maintenance. These results further elucidate the function of UHRF1, identify a non-histone target of G9a and GLP, and provide an example of a histone mimic that coordinates DNA replication and DNA methylation maintenance. Copyright © 2017 Elsevier Inc. All rights reserved.

Mechanisms of bacterial DNA replication restart

Science.gov (United States)

Windgassen, Tricia A; Wessel, Sarah R; Bhattacharyya, Basudeb

2018-01-01

Abstract Multi-protein DNA replication complexes called replisomes perform the essential process of copying cellular genetic information prior to cell division. Under ideal conditions, replisomes dissociate only after the entire genome has been duplicated. However, DNA replication rarely occurs without interruptions that can dislodge replisomes from DNA. Such events produce incompletely replicated chromosomes that, if left unrepaired, prevent the segregation of full genomes to daughter cells. To mitigate this threat, cells have evolved ‘DNA replication restart’ pathways that have been best defined in bacteria. Replication restart requires recognition and remodeling of abandoned replication forks by DNA replication restart proteins followed by reloading of the replicative DNA helicase, which subsequently directs assembly of the remaining replisome subunits. This review summarizes our current understanding of the mechanisms underlying replication restart and the proteins that drive the process in Escherichia coli (PriA, PriB, PriC and DnaT). PMID:29202195

Biphasic interactions between a cationic dendrimer and actin.

Science.gov (United States)

Ruenraroengsak, Pakatip; Florence, Alexander T

2010-12-01

Gene delivery systems face the problem not only of the route toward the cell and tissues in question, but also of the molecularly crowded environment of both the cytoplasm and the nucleus itself. One of the physical barriers in the cytoplasm for diffusing nanoparticles is an actin network. Here, we describe the finding that a self-fluorescent sixth generation cationic dendrimer (6 nm in diameter) interacts reversibly and possibly electrostatically with actin filaments in vitro. Not only does this interaction slow the diffusion of the dendrimer but it also affects actin polymerization in a biphasic manner. At low concentrations the dendrimer behaves like a G-binding actin protein, retarding actin polymerization, whereas at high concentrations the dendrimer acts as a nucleating protein accelerating the polymerization. Thus in vivo the diffusion of a dendrimer carrier such as this has both physical and chemical elements: by decreasing polymerization it might accelerate its own transport, and by enhancing actin polymerization retard it. This finding suggests that such a dendrimer may have a role as an anticancer agent through its inhibitory effect on actin polymerization.

A biphasic model for bleeding in soft tissue

Science.gov (United States)

Chang, Yi-Jui; Chong, Kwitae; Eldredge, Jeff D.; Teran, Joseph; Benharash, Peyman; Dutson, Erik

2017-11-01

The modeling of blood passing through soft tissues in the body is important for medical applications. The current study aims to capture the effect of tissue swelling and the transport of blood under bleeding or hemorrhaging conditions. The soft tissue is considered as a non-static poro-hyperelastic material with liquid-filled voids. A biphasic formulation effectively, a generalization of Darcy's law-is utilized, treating the phases as occupying fractions of the same volume. The interaction between phases is captured through a Stokes-like friction force on their relative velocities and a pressure that penalizes deviations from volume fractions summing to unity. The soft tissue is modeled as a hyperelastic material with a typical J-shaped stress-strain curve, while blood is considered as a Newtonian fluid. The method of Smoothed Particle Hydrodynamics is used to discretize the conservation equations based on the ease of treating free surfaces in the liquid. Simulations of swelling under acute hemorrhage and of draining under gravity and compression will be demonstrated. Ongoing progress in modeling of organ tissues under injuries and surgical conditions will be discussed.

A short G1 phase imposes constitutive replication stress and fork remodelling in mouse embryonic stem cells

DEFF Research Database (Denmark)

Ahuja, Akshay K.; Jodkowska, Karolina; Teloni, Federico

2016-01-01

Embryonic stem cells (ESCs) represent a transient biological state, where pluripotency is coupled with fast proliferation. ESCs display a constitutively active DNA damage response (DDR), but its molecular determinants have remained elusive. Here we show in cultured ESCs and mouse embryos that H2AX...... these marks of replication stress do not impair the mitotic process and are rapidly lost at differentiation onset. Delaying the G1/S transition in ESCs allows formation of 53BP1 nuclear bodies and suppresses ssDNA accumulation, fork slowing and reversal in the following S-phase. Genetic inactivation of fork...... slowing and reversal leads to chromosomal breakage in unperturbed ESCs. We propose that rapid cell cycle progression makes ESCs dependent on effective replication-coupled mechanisms to protect genome integrity....

What Should Researchers Expect When They Replicate Studies? A Statistical View of Replicability in Psychological Science.

Science.gov (United States)

Patil, Prasad; Peng, Roger D; Leek, Jeffrey T

2016-07-01

A recent study of the replicability of key psychological findings is a major contribution toward understanding the human side of the scientific process. Despite the careful and nuanced analysis reported, the simple narrative disseminated by the mass, social, and scientific media was that in only 36% of the studies were the original results replicated. In the current study, however, we showed that 77% of the replication effect sizes reported were within a 95% prediction interval calculated using the original effect size. Our analysis suggests two critical issues in understanding replication of psychological studies. First, researchers' intuitive expectations for what a replication should show do not always match with statistical estimates of replication. Second, when the results of original studies are very imprecise, they create wide prediction intervals-and a broad range of replication effects that are consistent with the original estimates. This may lead to effects that replicate successfully, in that replication results are consistent with statistical expectations, but do not provide much information about the size (or existence) of the true effect. In this light, the results of the Reproducibility Project: Psychology can be viewed as statistically consistent with what one might expect when performing a large-scale replication experiment. © The Author(s) 2016.

Interaction of the retinoblastoma protein with Orc1 and its recruitment to human origins of DNA replication.

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Ramiro Mendoza-Maldonado

Full Text Available BACKGROUND: The retinoblastoma protein (Rb is a crucial regulator of cell cycle progression by binding with E2F transcription factor and repressing the expression of a variety of genes required for the G1-S phase transition. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that Rb and E2F1 directly participate in the control of initiation of DNA replication in human HeLa, U2OS and T98G cells by specifically binding to origins of DNA replication in a cell cycle regulated manner. We show that, both in vitro and inside the cells, the largest subunit of the origin recognition complex (Orc1 specifically binds hypo-phosphorylated Rb and that this interaction is competitive with the binding of Rb to E2F1. The displacement of Rb-bound Orc1 by E2F1 at origins of DNA replication marks the progression of the G1 phase of the cell cycle toward the G1-S border. CONCLUSIONS/SIGNIFICANCE: The participation of Rb and E2F1 in the formation of the multiprotein complex that binds origins of DNA replication in mammalian cells appears to represent an effective mechanism to couple the expression of genes required for cell cycle progression to the activation of DNA replication.

A rare case of anal carcinosarcoma with human papilloma virus infection in both biphasic tumor elements: An immunohistochemical, molecular and ultrastructural study

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Richard A. Hickman

2016-12-01

Full Text Available Carcinosarcoma of the anus is rare and has yet to be reportedly associated with the keratinocyte-specific Human Papilloma Virus (HPV. We describe a case of anal carcinosarcoma with HPV infection in both the epithelial and mesenchymal components of the tumor by immunohistochemistry, chromogenic in-situ hybridization (CISH and further supported by electron microscopy (EM. Microscopic examination of the tumor showed nests of poorly-differentiated invasive squamous cell carcinoma with basaloid features intermixed with a hypercellular, atypical spindle cell proliferation. Immunohistochemistry demonstrated that the epithelial component was positive for AE1/AE3, p63, CK5/6 and p16, whilst the mesenchymal component was positive for smooth muscle actin, vimentin, and focally positive for desmin and p16, consistent with carcinosarcoma. The tumor was negative for GATA-3, CK7 and CK20. CISH demonstrated that the tumor was positive for high risk HPV (subtype 16/18 in both tumor components. EM further supported the presence of intracellular virus particles (~50 nm that is compatible with HPV infection. Infection of both epithelial and mesenchymal tumor components by HPV has not been previously observed in the gastrointestinal tract. This finding may represent initial epithelial HPV infection with subsequent divergent tumoral differentiation and suggests the presence of viral replication in both biphasic tumor components. Keywords: Carcinosarcoma, Human Papilloma Virus, Gastrointestinal

Distinguishing butchery cut marks from crocodile bite marks through machine learning methods.

Science.gov (United States)

Domínguez-Rodrigo, Manuel; Baquedano, Enrique

2018-04-10

All models of evolution of human behaviour depend on the correct identification and interpretation of bone surface modifications (BSM) on archaeofaunal assemblages. Crucial evolutionary features, such as the origin of stone tool use, meat-eating, food-sharing, cooperation and sociality can only be addressed through confident identification and interpretation of BSM, and more specifically, cut marks. Recently, it has been argued that linear marks with the same properties as cut marks can be created by crocodiles, thereby questioning whether secure cut mark identifications can be made in the Early Pleistocene fossil record. Powerful classification methods based on multivariate statistics and machine learning (ML) algorithms have previously successfully discriminated cut marks from most other potentially confounding BSM. However, crocodile-made marks were marginal to or played no role in these comparative analyses. Here, for the first time, we apply state-of-the-art ML methods on crocodile linear BSM and experimental butchery cut marks, showing that the combination of multivariate taphonomy and ML methods provides accurate identification of BSM, including cut and crocodile bite marks. This enables empirically-supported hominin behavioural modelling, provided that these methods are applied to fossil assemblages.

Effects of cetyltriethylammonium bromide on the replication of Bombyx mori nucleopolyhedrovirus.

Science.gov (United States)

Zhou, Yajing; Zhang, Zhifang; He, Jialu; Zhang, Yuanxing

2002-05-01

An experimental study was undertaken to quantify the effects of cetyltriethylammonium bromide (CTAB) on the replication of Bombyx mori nucleopolyhedrovirus (BmNPV) and the transcriptionalactivity of BmNPV ie-1 promoter. The results demonstrated that the budded virus (BV) titer rose about 3.7-fold by adding CTAB to the culture media up to 0.1 mu g ml(-1) in infected Bm-N cells with a wild-type BmNPV. The transient expression level of luciferase driven by BmNPV ie-1 promoter was enhanced by more than 3-fold in the presence of 0.1 mu g ml(-1) of CTAB in uninfected insect cells via a transient expression system. Contrary to the rise in BV titer, the polyhedra inside the nucleus of infected cells dropped linearly from 4.0 x 10(6) ml(-1) down to 2.1 x 10(6) ml(-1) with in a range of CTAB concentrations from 0 to 0.25 mu g ml(-1). The same trend in expression level of beta -galactosidase or phytase was given when the Bm-N cells or fifth-instar silkworm larvae infected with a recombinant BmNPV containing the beta -galactosidase or phytase reporter gene driven by the polyhedrin promoter. We deduced that CTAB appeared to affect the virus bi-phasic life cycle stages and production pathways, resulting in an enhancement in BV production and a suppression of occluded virus (OV) production and expression of foreign genes controlled by the polyhedrin promoter.

Dynamic remodeling of lipids coincides with dengue virus replication in the midgut of Aedes aegypti mosquitoes.

Directory of Open Access Journals (Sweden)

Nunya Chotiwan

2018-02-01

Full Text Available We describe the first comprehensive analysis of the midgut metabolome of Aedes aegypti, the primary mosquito vector for arboviruses such as dengue, Zika, chikungunya and yellow fever viruses. Transmission of these viruses depends on their ability to infect, replicate and disseminate from several tissues in the mosquito vector. The metabolic environments within these tissues play crucial roles in these processes. Since these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of host metabolism. Interference with this virus infection-induced metabolic environment is detrimental to viral replication in human and mosquito cell culture models. Here we present the first insight into the metabolic environment induced during arbovirus replication in Aedes aegypti. Using high-resolution mass spectrometry, we have analyzed the temporal metabolic perturbations that occur following dengue virus infection of the midgut tissue. This is the primary site of infection and replication, preceding systemic viral dissemination and transmission. We identified metabolites that exhibited a dynamic-profile across early-, mid- and late-infection time points. We observed a marked increase in the lipid content. An increase in glycerophospholipids, sphingolipids and fatty acyls was coincident with the kinetics of viral replication. Elevation of glycerolipid levels suggested a diversion of resources during infection from energy storage to synthetic pathways. Elevated levels of acyl-carnitines were observed, signaling disruptions in mitochondrial function and possible diversion of energy production. A central hub in the sphingolipid pathway that influenced dihydroceramide to ceramide ratios was identified as critical for the virus life cycle. This study also resulted in the first reconstruction of the sphingolipid pathway in Aedes aegypti. Given conservation in the replication mechanisms of several

Dynamic remodeling of lipids coincides with dengue virus replication in the midgut of Aedes aegypti mosquitoes.

Science.gov (United States)

Chotiwan, Nunya; Andre, Barbara G; Sanchez-Vargas, Irma; Islam, M Nurul; Grabowski, Jeffrey M; Hopf-Jannasch, Amber; Gough, Erik; Nakayasu, Ernesto; Blair, Carol D; Belisle, John T; Hill, Catherine A; Kuhn, Richard J; Perera, Rushika

2018-02-01

We describe the first comprehensive analysis of the midgut metabolome of Aedes aegypti, the primary mosquito vector for arboviruses such as dengue, Zika, chikungunya and yellow fever viruses. Transmission of these viruses depends on their ability to infect, replicate and disseminate from several tissues in the mosquito vector. The metabolic environments within these tissues play crucial roles in these processes. Since these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of host metabolism. Interference with this virus infection-induced metabolic environment is detrimental to viral replication in human and mosquito cell culture models. Here we present the first insight into the metabolic environment induced during arbovirus replication in Aedes aegypti. Using high-resolution mass spectrometry, we have analyzed the temporal metabolic perturbations that occur following dengue virus infection of the midgut tissue. This is the primary site of infection and replication, preceding systemic viral dissemination and transmission. We identified metabolites that exhibited a dynamic-profile across early-, mid- and late-infection time points. We observed a marked increase in the lipid content. An increase in glycerophospholipids, sphingolipids and fatty acyls was coincident with the kinetics of viral replication. Elevation of glycerolipid levels suggested a diversion of resources during infection from energy storage to synthetic pathways. Elevated levels of acyl-carnitines were observed, signaling disruptions in mitochondrial function and possible diversion of energy production. A central hub in the sphingolipid pathway that influenced dihydroceramide to ceramide ratios was identified as critical for the virus life cycle. This study also resulted in the first reconstruction of the sphingolipid pathway in Aedes aegypti. Given conservation in the replication mechanisms of several flaviviruses transmitted

Comparison between FEBio and Abaqus for biphasic contact problems.

Science.gov (United States)

Meng, Qingen; Jin, Zhongmin; Fisher, John; Wilcox, Ruth

2013-09-01

Articular cartilage plays an important role in the function of diarthrodial joints. Computational methods have been used to study the biphasic mechanics of cartilage, and Abaqus has been one of the most widely used commercial software packages for this purpose. A newly developed open-source finite element solver, FEBio, has been developed specifically for biomechanical applications. The aim of this study was to undertake a direct comparison between FEBio and Abaqus for some practical contact problems involving cartilage. Three model types, representing a porous flat-ended indentation test, a spherical-ended indentation test, and a conceptual natural joint contact model, were compared. In addition, a parameter sensitivity study was also performed for the spherical-ended indentation test to investigate the effects of changes in the input material properties on the model outputs, using both FEBio and Abaqus. Excellent agreement was found between FEBio and Abaqus for all of the model types and across the range of material properties that were investigated.

DNA Replication Profiling Using Deep Sequencing.

Science.gov (United States)

Saayman, Xanita; Ramos-Pérez, Cristina; Brown, Grant W

2018-01-01

Profiling of DNA replication during progression through S phase allows a quantitative snap-shot of replication origin usage and DNA replication fork progression. We present a method for using deep sequencing data to profile DNA replication in S. cerevisiae.

Probing the limit of magnesium uptake by β-tricalcium phosphate in biphasic mixtures formed from calcium deficient apatites

Energy Technology Data Exchange (ETDEWEB)

Kumar, P. Nandha; Mishra, Sandeep K.; Kannan, S., E-mail: para_kanna@yahoo.com

2015-11-15

A series of magnesium doped non-stoichiometric calcium deficient apatites were synthesized through an aqueous precipitation route. The resultant structural changes during heat treatment were investigated by X-ray diffraction, Raman and FT-IR spectroscopy and Rietveld refinement. The results confirmed the formation of biphasic mixtures comprising Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and β-Ca{sub 3}(PO{sub 4}){sub 2} after heat treatment at 1000 °C with the preferential occupancy of Mg{sup 2+} at the crystal lattice of β-Ca{sub 3}(PO{sub 4}){sub 2}. The concentration of Mg{sup 2+} uptake in β-Ca{sub 3}(PO{sub 4}){sub 2} is limited till reaching the stoichiometric ratio of (Ca+Mg)/P=1.67 and beyond this stoichiometric value [(Ca+Mg)/P>1.67], Mg{sup 2+} precipitates as Mg(OH){sub 2} and thereafter gets converted to MgO during heat treatment. Any kind of Mg{sup 2+} uptake in the crystal lattice of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} is discarded from the investigation. - Highlights: • Aqueous co-precipitation of calcium deficient apatites with excess magnesium (Mg{sup 2+}) additions. • Heat treatments beyond 800 °C results in the formation of biphasic apatite mixtures. • Mg{sup 2+} gets accommodated at the β-Ca{sub 3}(PO{sub 4}){sub 2} lattice of biphasic mixtures. • Mg{sup 2+} additions exceeding stoichiometric value (Ca/P>1.67) results in its formation as MgO. • Mg{sup 2+} occupancy at β-Ca{sub 3}(PO{sub 4}){sub 2} lattice delays its allotropic conversion α-Ca{sub 3}(PO{sub 4}){sub 2} till 1350 °C.

Comparison of the effects of nafenopin, methyl clofenapate, WY-14,643 and clofibric acid on peroxisome proliferation and replicative DNA synthesis in rat liver

International Nuclear Information System (INIS)

Price, R.J.; Evans, J.G.; Lake, B.G.; Gangolli, S.D.

1991-01-01

A wide variety of chemicals have been shown to produce hepatic peroxisome proliferation (PP) in the rat and certain of these compounds are also hepatocarcinogens. In this study the authors have investigated the relationship between PP and cell replication in the rat liver. Male Sprague-Dawley rats were fed control diet or diet containing either 0.0125 and 0.05% nafenopin (NAF), 0.05% methyl clofenapate (MC), 0.025% Wy-14,643 (WY) or 0.5% clofibric acid (CA) for 1 and 15 wk. All four compounds produced marked liver enlargement and a sustained induction of peroxisomal (palmitoyl-CoA oxidation) and microsomal (lauric acid 12-hydroxylase) fatty acid oxidizing enzyme activities. Enzyme induction was less marked with 0.0125% NAF than with 0.05% NAF which was similar to that produced by the other three compounds. Replicative DNA synthesis was studied by implanting 7 day Alzet osmotic pumps containing [ 3 H]thymidine during wk 0-1 and 14-15. After 1 wk replicative DNA synthesis (assessed as radioactivity incorporated into homogenate DNA by scintillation counting) was increased in all treatment groups to 170-325% of control levels. Hepatocyte Labelling Index (determined by autoradiography of liver sections) was increased in all treated groups. After 15 wk hepatic DNA radioactivity levels were 155 and 200% of control in MC and WY treated rats, respectively, whereas NAF and CA had no effect. These results demonstrate that the relationship between the magnitude of PP and induction of cell replication depends on the compound being studied and that some peroxisome proliferators produce sustained stimulation of replicative DNA synthesis in the rat

Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review

International Nuclear Information System (INIS)

Schieda, Nicola; McInnes, Matthew D.F.; Cao, Lilly

2014-01-01

To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 x 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. (orig.)

Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review

Energy Technology Data Exchange (ETDEWEB)

Schieda, Nicola; McInnes, Matthew D.F.; Cao, Lilly [Ottawa Hospital Research Institute, Department of Medical Imaging, Ottawa, ON (Canada)

2014-06-15

To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 x 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. (orig.)

Induction of UV-resistant DNA replication in Escherichia coli: Induced stable DNA replication as an SOS function

International Nuclear Information System (INIS)

Kogoma, T.; Torrey, T.A.; Connaughton, M.J.

1979-01-01

The striking similarity between the treatments that induce SOS functions and those that result in stable DNA replication (continuous DNA replication in the absence of protein synthesis) prompted us to examine the possibility of stable DNA replication being a recA + lexA + -dependent SOS function. In addition to the treatments previously reported, ultraviolet (UV) irradiation or treatment with mitomycin C was also found to induce stable DNA replication. The thermal treatment of tif-1 strains did not result in detectable levels of stable DNA replication, but nalidixic acid readily induced the activity in these strains. The induction of stable DNA replication with nalidixic acid was severely suppressed in tif-1 lex A mutant strains. The inhibitory activity of lexA3 was negated by the presence of the spr-5l mutation, an intragenic suppressor of lexA3. Induced stable DNA replication was found to be considerably more resistant to UV irradiation than normal replication both in a uvr A6 strain and a uvr + strain. The UV-resistant replication occurred mostly in the semiconservative manner. The possible roles of stable DNA replication in repair of damaged DNA are discussed. (orig.)

Chromatin replication and epigenome maintenance

DEFF Research Database (Denmark)

Alabert, Constance; Groth, Anja

2012-01-01

Stability and function of eukaryotic genomes are closely linked to chromatin structure and organization. During cell division the entire genome must be accurately replicated and the chromatin landscape reproduced on new DNA. Chromatin and nuclear structure influence where and when DNA replication...... initiates, whereas the replication process itself disrupts chromatin and challenges established patterns of genome regulation. Specialized replication-coupled mechanisms assemble new DNA into chromatin, but epigenome maintenance is a continuous process taking place throughout the cell cycle. If DNA...

Biphasic voltage-dependent inactivation of human NaV 1.3, 1.6 and 1.7 Na+ channels expressed in rodent insulin-secreting cells.

Science.gov (United States)

Godazgar, Mahdieh; Zhang, Quan; Chibalina, Margarita V; Rorsman, Patrik

2018-05-01

Na + current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na + (Na V ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single Na V subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that Na V channels adopt different inactivation behaviours depending on the local membrane environment. Pancreatic β-cells are equipped with voltage-gated Na + channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na + current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na + channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different Na V α-subunits. We tested this possibility by expression of TTX-resistant variants of the Na V subunits found in β-cells (Na V 1.3, Na V 1.6 and Na V 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all Na V subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. Na V 1.7 inactivated at 15--20 mV more negative membrane potentials than Na V 1.3 and Na V 1.6 in Ins1 cells but this small difference is insufficient to solely

36 CFR 910.64 - Replication.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Replication. 910.64 Section 910.64 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL... DEVELOPMENT AREA Glossary of Terms § 910.64 Replication. Replication means the process of using modern methods...

Comparison of a soluble co-formulation of insulin degludec/insulin aspart vs biphasic insulin aspart 30 in type 2 diabetes

DEFF Research Database (Denmark)

Niskanen, Leo; Leiter, Lawrence A; Franek, Edward

2012-01-01

Insulin degludec/insulin aspart (IDegAsp) is a soluble co-formulation of insulin degludec (70%) and insulin aspart (IAsp: 30%). Here, we compare the efficacy and safety of IDegAsp, an alternative IDegAsp formulation (AF: containing 45% IAsp), and biphasic IAsp 30 (BIAsp 30)....

Is there an Optimal Shape of the Defibrillation Shock: Constant Current vs. Pulsed Biphasic Waveforms

Directory of Open Access Journals (Sweden)

Ivan Dotsinsky

2013-04-01

Full Text Available Three waveforms for transthoracic defibrillation are assessed and compared: the Pulsed Biphasic Waveform (PBW, the Rectilinear Biphasic Waveform (RBW, and the "lossless" constant current (LLCC pulses. Two indices are introduced: 1 kf = W/W0 - the ratio between the delivered energy W and the energy W0 of a rectangular pulse with the same duration and electric charge; 2 ηC = W/WC0 - the level of utilizing the initially loaded capacitor energy WC0. The envisioned comparative study shows that ηC index is favorable for both PBW and LLCC, while kf of both RBW and LLCC demonstrates advantage over the PBW in the range of small inter-electrode thoracic impedances below 80 Ω. Some design considerations are also discussed. The attractive LLCC concept needs large and heavy inductive coil to support the constant current amplitude, besides it is capable to induce strong electromagnetic influences due to the complex current control. The RBW technology controls the delivery of current through a series of internal resistors which are, however, a source of high heat losses. The PBW implements controlled duty cycle of high-frequency chopped pulses to adapt the energy delivery in respect of the patient impedance measured at the beginning of the shock. PBW technology makes use of small capacitors which allows the construction of light weight and small-size portable devices for transthoracic defibrillation.

Replication stress-induced chromosome breakage is correlated with replication fork progression and is preceded by single-stranded DNA formation.

Science.gov (United States)

Feng, Wenyi; Di Rienzi, Sara C; Raghuraman, M K; Brewer, Bonita J

2011-10-01

Chromosome breakage as a result of replication stress has been hypothesized to be the direct consequence of defective replication fork progression, or "collapsed" replication forks. However, direct and genome-wide evidence that collapsed replication forks give rise to chromosome breakage is still lacking. Previously we showed that a yeast replication checkpoint mutant mec1-1, after transient exposure to replication impediment imposed by hydroxyurea (HU), failed to complete DNA replication, accumulated single-stranded DNA (ssDNA) at the replication forks, and fragmented its chromosomes. In this study, by following replication fork progression genome-wide via ssDNA detection and by direct mapping of chromosome breakage after HU exposure, we have tested the hypothesis that the chromosome breakage in mec1 cells occurs at collapsed replication forks. We demonstrate that sites of chromosome breakage indeed correlate with replication fork locations. Moreover, ssDNA can be detected prior to chromosome breakage, suggesting that ssDNA accumulation is the common precursor to double strand breaks at collapsed replication forks.

Biphasic pulses enhance bleomycin efficacy in a spontaneous canine genital tumor model of chemoresistance: Sticker sarcoma

Directory of Open Access Journals (Sweden)

Citro Gennaro

2008-11-01

Full Text Available Abstract Sticker's sarcoma (also known as transmissible venereal tumor is a horizontally transmitted neoplasm of the dog, that is passed with coitus. It is a locally aggressive tumor with a low tendency to metastatic spread. The most common locations are the genitals, the nose, the perianal area. Standard treatment consists with chemotherapy with vincristine, however other therapies such as, cryotherapy, immunotherapy or, in selected cases, radiation therapy, have been reported. In this article we describe the outcome of a small cohort of canine patients, with chemotherapy resistant transmissible venereal tumor (TVT, treated with bleomycin selectively driven by trains of biphasic pulses (electrochemotherapy. Three canine patients, with refractory TVT, entered the study and received two sessions of ECT under sedation. The pets had local injection of bleomycin at the concentration of 1.5 mg/ml and five minutes after the chemotherapy, trains of 8 biphasic electric pulses lasting 50 + 50 μs each, with 1 ms interpulse intervals, were delivered by means of modified caliper or, for difficult districts, through paired needle electrode. All the patients responded to the treatment and are still in remission at different times. Electrochemotherapy appears as a safe and efficacious modality for the treatment of TVT and warrants further investigations.

Biphasic effect of citral, a flavoring and scenting agent, on spatial learning and memory in rats.

Science.gov (United States)

Yang, Zheqiong; Xi, Jinlei; Li, Jihong; Qu, Wen

2009-10-01

Although some central effects of citral have been reported, cognitive effects on spatial memory have not been investigated. The evidence showed that citral can regulate the synthesis of retinoic acid (RA), which exerts a vital function in the development and maintenance of spatial memory. In this study, we applied Morris water maze to test the effect of citral on animals' spatial learning and memory. To elucidate the mechanism of this effect, we also measured the retinoic acid concentration in rats' hippocampus by high performance liquid chromatography (HPLC). Our data implied biphasic effects of citral. The low dose (0.1 mg/kg) of citral improved the spatial learning capability, and enhanced the spatial reference memory of rats, whereas the high dose (1.0 mg/kg) was like to produce the opposite effects. Meanwhile, the low dose of citral increased the hippocampal retinoic acid concentration, while the high dose decreased it. Due to the quick elimination and non-bioaccumulation in the body, effects of citral on spatial memory in this study seemed to be indirect actions. The change in hippocampal retinoic acid concentration induced by different doses of citral might be responsible for the biphasic effect of citral on spatial learning and memory.

Mark Tompkins Canaccord

OpenAIRE

Mark Tompkins Canaccord

2018-01-01

Mark Tompkins Canaccord is a senior technologist for ecosystem and water resources management in SEC SAID Oakland, California office. In his career which lasts over fifteen years Mark has worked on project involving lake restorations, clean water engineering, ecological engineering and management, hydrology, hydraulics, sediment transport and other projects for environmental planning all over the country. Mark Tompkins Canaccord tries to blend his skills of planning and engineering with s...

Reconfiguring trade mark law

DEFF Research Database (Denmark)

Elsmore, Matthew James

2013-01-01

-border setting, with a particular focus on small business and consumers. The article's overall message is to call for a rethink of received wisdom suggesting that trade marks are effective trade-enabling devices. The case is made for reassessing how we think about European trade mark law.......First, this article argues that trade mark law should be approached in a supplementary way, called reconfiguration. Second, the article investigates such a reconfiguration of trade mark law by exploring the interplay of trade marks and service transactions in the Single Market, in the cross...

Bi-phasic regulation of glycogen content in astrocytes via Cav-1/PTEN/PI3K/AKT/GSK-3β pathway by fluoxetine.

Science.gov (United States)

Bai, Qiufang; Song, Dan; Gu, Li; Verkhratsky, Alexei; Peng, Liang

2017-04-01

Here, we present the data indicating that chronic treatment with fluoxetine regulates Cav-1/PTEN/PI3K/AKT/GSK-3β signalling pathway and glycogen content in primary cultures of astrocytes with bi-phasic concentration dependence. At lower concentrations, fluoxetine downregulates gene expression of Cav-1, decreases membrane content of PTEN, increases activity of PI3K/AKT, and elevates GSK-3β phosphorylation thus suppressing its activity. At higher concentrations, fluoxetine acts in an inverse fashion. As expected, fluoxetine at lower concentrations increased while at higher concentrations decreased glycogen content in astrocytes. Our findings indicate that bi-phasic regulation of glycogen content via Cav-1/PTEN/PI3K/AKT/GSK-3β pathway by fluoxetine may be responsible for both therapeutic and side effects of the drug.

Replication Research and Special Education

Science.gov (United States)

Travers, Jason C.; Cook, Bryan G.; Therrien, William J.; Coyne, Michael D.

2016-01-01

Replicating previously reported empirical research is a necessary aspect of an evidence-based field of special education, but little formal investigation into the prevalence of replication research in the special education research literature has been conducted. Various factors may explain the lack of attention to replication of special education…

Mutational analysis of the hypervariable region of hepatitis e virus reveals its involvement in the efficiency of viral RNA replication.

Science.gov (United States)

Pudupakam, R S; Kenney, Scott P; Córdoba, Laura; Huang, Yao-Wei; Dryman, Barbara A; Leroith, Tanya; Pierson, F William; Meng, Xiang-Jin

2011-10-01

The RNA genome of the hepatitis E virus (HEV) contains a hypervariable region (HVR) in ORF1 that tolerates small deletions with respect to infectivity. To further investigate the role of the HVR in HEV replication, we constructed a panel of mutants with overlapping deletions in the N-terminal, central, and C-terminal regions of the HVR by using a genotype 1 human HEV luciferase replicon and analyzed the effects of deletions on viral RNA replication in Huh7 cells. We found that the replication levels of the HVR deletion mutants were markedly reduced in Huh7 cells, suggesting a role of the HVR in viral replication efficiency. To further verify the results, we constructed HVR deletion mutants by using a genetically divergent, nonmammalian avian HEV, and similar effects on viral replication efficiency were observed when the avian HEV mutants were tested in LMH cells. Furthermore, the impact of complete HVR deletion on virus infectivity was tested in chickens, using an avian HEV mutant with a complete HVR deletion. Although the deletion mutant was still replication competent in LMH cells, the complete HVR deletion resulted in a loss of avian HEV infectivity in chickens. Since the HVR exhibits extensive variations in sequence and length among different HEV genotypes, we further examined the interchangeability of HVRs and demonstrated that HVR sequences are functionally exchangeable between HEV genotypes with regard to viral replication and infectivity in vitro, although genotype-specific HVR differences in replication efficiency were observed. The results showed that although the HVR tolerates small deletions with regard to infectivity, it may interact with viral and host factors to modulate the efficiency of HEV replication.

Eukaryotic DNA Replication Fork.

Science.gov (United States)

Burgers, Peter M J; Kunkel, Thomas A

2017-06-20

This review focuses on the biogenesis and composition of the eukaryotic DNA replication fork, with an emphasis on the enzymes that synthesize DNA and repair discontinuities on the lagging strand of the replication fork. Physical and genetic methodologies aimed at understanding these processes are discussed. The preponderance of evidence supports a model in which DNA polymerase ε (Pol ε) carries out the bulk of leading strand DNA synthesis at an undisturbed replication fork. DNA polymerases α and δ carry out the initiation of Okazaki fragment synthesis and its elongation and maturation, respectively. This review also discusses alternative proposals, including cellular processes during which alternative forks may be utilized, and new biochemical studies with purified proteins that are aimed at reconstituting leading and lagging strand DNA synthesis separately and as an integrated replication fork.

The progression of replication forks at natural replication barriers in live bacteria

NARCIS (Netherlands)

Moolman, M.C.; Tiruvadi Krishnan, S; Kerssemakers, J.W.J.; de Leeuw, R.; Lorent, V.J.F.; Sherratt, David J.; Dekker, N.H.

2016-01-01

Protein-DNA complexes are one of the principal barriers the replisome encounters during replication. One such barrier is the Tus-ter complex, which is a direction dependent barrier for replication fork progression. The details concerning the dynamics of the replisome when encountering these

Flock House virus subgenomic RNA3 is replicated and its replication correlates with transactivation of RNA2

International Nuclear Information System (INIS)

Eckerle, Lance D.; Albarino, Cesar G.; Ball, L. Andrew.

2003-01-01

The nodavirus Flock House virus has a bipartite genome composed of RNAs 1 and 2, which encode the catalytic component of the RNA-dependent RNA polymerase (RdRp) and the capsid protein precursor, respectively. In addition to catalyzing replication of the viral genome, the RdRp also transcribes from RNA1 a subgenomic RNA3, which is both required for and suppressed by RNA2 replication. Here, we show that in the absence of RNA1 replication, FHV RdRp replicated positive-sense RNA3 transcripts fully and copied negative-sense RNA3 transcripts into positive strands. The two nonstructural proteins encoded by RNA3 were dispensable for replication, but sequences in the 3'-terminal 58 nucleotides were required. RNA3 variants that failed to replicate also failed to transactivate RNA2. These results imply that RNA3 is naturally produced both by transcription from RNA1 and by subsequent RNA1-independent replication and that RNA3 replication may be necessary for transactivation of RNA2

Chromatin Heterogeneity and Distribution of Regulatory Elements in the Late-Replicating Intercalary Heterochromatin Domains of Drosophila melanogaster Chromosomes.

Directory of Open Access Journals (Sweden)

Varvara A Khoroshko

Full Text Available Late-replicating domains (intercalary heterochromatin in the Drosophila genome display a number of features suggesting their organization is quite unique. Typically, they are quite large and encompass clusters of functionally unrelated tissue-specific genes. They correspond to the topologically associating domains and conserved microsynteny blocks. Our study aims at exploring further details of molecular organization of intercalary heterochromatin and has uncovered surprising heterogeneity of chromatin composition in these regions. Using the 4HMM model developed in our group earlier, intercalary heterochromatin regions were found to host chromatin fragments with a particular epigenetic profile. Aquamarine chromatin fragments (spanning 0.67% of late-replicating regions are characterized as a class of sequences that appear heterogeneous in terms of their decompactization. These fragments are enriched with enhancer sequences and binding sites for insulator proteins. They likely mark the chromatin state that is related to the binding of cis-regulatory proteins. Malachite chromatin fragments (11% of late-replicating regions appear to function as universal transitional regions between two contrasting chromatin states. Namely, they invariably delimit intercalary heterochromatin regions from the adjacent active chromatin of interbands. Malachite fragments also flank aquamarine fragments embedded in the repressed chromatin of late-replicating regions. Significant enrichment of insulator proteins CP190, SU(HW, and MOD2.2 was observed in malachite chromatin. Neither aquamarine nor malachite chromatin types appear to correlate with the positions of highly conserved non-coding elements (HCNE that are typically replete in intercalary heterochromatin. Malachite chromatin found on the flanks of intercalary heterochromatin regions tends to replicate earlier than the malachite chromatin embedded in intercalary heterochromatin. In other words, there exists a

DNA Replication Control During Drosophila Development: Insights into the Onset of S Phase, Replication Initiation, and Fork Progression

Science.gov (United States)

Hua, Brian L.; Orr-Weaver, Terry L.

2017-01-01

Proper control of DNA replication is critical to ensure genomic integrity during cell proliferation. In addition, differential regulation of the DNA replication program during development can change gene copy number to influence cell size and gene expression. Drosophila melanogaster serves as a powerful organism to study the developmental control of DNA replication in various cell cycle contexts in a variety of differentiated cell and tissue types. Additionally, Drosophila has provided several developmentally regulated replication models to dissect the molecular mechanisms that underlie replication-based copy number changes in the genome, which include differential underreplication and gene amplification. Here, we review key findings and our current understanding of the developmental control of DNA replication in the contexts of the archetypal replication program as well as of underreplication and differential gene amplification. We focus on the use of these latter two replication systems to delineate many of the molecular mechanisms that underlie the developmental control of replication initiation and fork elongation. PMID:28874453

BWR Mark I pressure suppression study: bench mark experiments

International Nuclear Information System (INIS)

Lai, W.; McCauley, E.W.

1977-01-01

Computer simulations representative of the wetwell of Mark I BWR's have predicted pressures and related phenomena. However, calculational predictions for purposes of engineering decision will be possible only if the code can be verified, i.e., shown to compute in accord with measured values. Described in the report is a set of single downcomer spherical flask bench mark experiments designed to produce quantitative data to validate various air-water dynamic computations; the experiments were performed since relevant bench mark data were not available from outside sources. Secondary purposes of the study were to provide a test bed for the instrumentation and post-experiment data processing techniques to be used in the Laboratory's reactor safety research program and to provide additional masurements for the air-water scaling study

Elemental marking of arthropod pests in agricultural systems: single and multigenerational marking

Science.gov (United States)

Jane Leslie Hayes

1991-01-01

Use of elemental markers to study movement of arthropod pests of field crops is reviewed. Trace elements, rubidium (Rb) and cesium (Cs), have provided a nondisruptive method of marking natural adult populations via developmental stage consumption of treated host plants. Multigenerational marking occurs with the transfer of elemental markers from marked adults to...

New biphasic monocomponent composite material obtained by the partial oxypropylation of bacterial cellulose

International Nuclear Information System (INIS)

Rosa, Joyce Rover; Silva, Ingrid S.V. da; Pasquini, Daniel; Santos, Daniele B. dos; Barud, Hernane S.; Ribeiro, Sidney J.L.

2011-01-01

This study aimed to partial oxypropylation of bacterial cellulose (CB), as well as the characterization of pure CB, oxypropylated CB (CBO) and oxypropylated CB after Soxhlet extraction with hexane (CBOE). The oxypropylation reaction was carried out by propylene oxide polymerization, catalyzed by KOH, in the presence of CB The CB samples, before and after modification, were subjected to analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was possible verify that the partial transformation of bacterial cellulose by inserting a layer of thermoplastic polymer on its surface occurred efficiently, obtaining a biphasic monocomponent composite material. (author)

The progression of replication forks at natural replication barriers in live bacteria.

Science.gov (United States)

Moolman, M Charl; Tiruvadi Krishnan, Sriram; Kerssemakers, Jacob W J; de Leeuw, Roy; Lorent, Vincent; Sherratt, David J; Dekker, Nynke H

2016-07-27

Protein-DNA complexes are one of the principal barriers the replisome encounters during replication. One such barrier is the Tus-ter complex, which is a direction dependent barrier for replication fork progression. The details concerning the dynamics of the replisome when encountering these Tus-ter barriers in the cell are poorly understood. By performing quantitative fluorescence microscopy with microfuidics, we investigate the effect on the replisome when encountering these barriers in live Escherichia coli cells. We make use of an E. coli variant that includes only an ectopic origin of replication that is positioned such that one of the two replisomes encounters a Tus-ter barrier before the other replisome. This enables us to single out the effect of encountering a Tus-ter roadblock on an individual replisome. We demonstrate that the replisome remains stably bound after encountering a Tus-ter complex from the non-permissive direction. Furthermore, the replisome is only transiently blocked, and continues replication beyond the barrier. Additionally, we demonstrate that these barriers affect sister chromosome segregation by visualizing specific chromosomal loci in the presence and absence of the Tus protein. These observations demonstrate the resilience of the replication fork to natural barriers and the sensitivity of chromosome alignment to fork progression. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Influence of saline solution on hydration behavior of β-dicalcium silicate in comparison with biphasic calcium phosphate/hydroxyapatite bio-ceramics

Energy Technology Data Exchange (ETDEWEB)

Radwan, M.M., E-mail: mmahmoudradwan@yahoo.com [Ceramics Dept, National Research Centre, Cairo (Egypt); Abd El-Hamid, H.K. [Ceramics Dept, National Research Centre, Cairo (Egypt); Mohamed, A.F. [The Holding Company for Production of Vaccines, Sera and Drugs (EGYVAC) (Egypt)

2015-12-01

The influence of using saline solution as mixing and curing liquid on some characteristics of β-dicalcium silicate (β-C{sub 2}S) and biphasic compound tri-calcium phosphate/hydroxyapatite (TCP/HAp) bio-ceramics was investigated. β-C{sub 2}S (27–30 nm) was prepared by solid state reaction at 1450 °C, while biphasic compound TCP/HAp (7–15 nm) was synthesized from an aqueous solution of Ca(NO{sub 3}){sub 2}·4H{sub 2}O and (NH{sub 4}){sub 2}HPO{sub 4}·12H{sub 2}O by chemical precipitation method. Setting times, compressive strength, pH values, X-ray diffraction analysis, infrared spectroscopy, scanning electron microscopy (SEM) were investigated. The evaluation of cytotoxicity of both calcium silicate and biphasic compounds to human gingival fibroblasts was carried out. The use of saline solution as mixing and immersing liquid shortened the setting time for the two bio-cements. TCP/HAp did not show any mechanical strength but β-C{sub 2}S showed good strength values. Both synthesized compounds showed a moderate cytotoxicity and both materials were effective in a no significant way. - Highlights: • The dissolution and hydration of β-C{sub 2}S and TCP/HAp in distilled water and saline solution were studied. • TCP/HAp did not show mechanical strength, while β-C{sub 2}S showed good mechanical strength. • The use of saline solution did enhances the dissolution & hydration rate. • An increase in pH values was detected when using saline solution. • Both materials showed a moderate cytotoxicity in no significant way.

Mutational Analysis of the Hypervariable Region of Hepatitis E Virus Reveals Its Involvement in the Efficiency of Viral RNA Replication ▿

Science.gov (United States)

Pudupakam, R. S.; Kenney, Scott P.; Córdoba, Laura; Huang, Yao-Wei; Dryman, Barbara A.; LeRoith, Tanya; Pierson, F. William; Meng, Xiang-Jin

2011-01-01

The RNA genome of the hepatitis E virus (HEV) contains a hypervariable region (HVR) in ORF1 that tolerates small deletions with respect to infectivity. To further investigate the role of the HVR in HEV replication, we constructed a panel of mutants with overlapping deletions in the N-terminal, central, and C-terminal regions of the HVR by using a genotype 1 human HEV luciferase replicon and analyzed the effects of deletions on viral RNA replication in Huh7 cells. We found that the replication levels of the HVR deletion mutants were markedly reduced in Huh7 cells, suggesting a role of the HVR in viral replication efficiency. To further verify the results, we constructed HVR deletion mutants by using a genetically divergent, nonmammalian avian HEV, and similar effects on viral replication efficiency were observed when the avian HEV mutants were tested in LMH cells. Furthermore, the impact of complete HVR deletion on virus infectivity was tested in chickens, using an avian HEV mutant with a complete HVR deletion. Although the deletion mutant was still replication competent in LMH cells, the complete HVR deletion resulted in a loss of avian HEV infectivity in chickens. Since the HVR exhibits extensive variations in sequence and length among different HEV genotypes, we further examined the interchangeability of HVRs and demonstrated that HVR sequences are functionally exchangeable between HEV genotypes with regard to viral replication and infectivity in vitro, although genotype-specific HVR differences in replication efficiency were observed. The results showed that although the HVR tolerates small deletions with regard to infectivity, it may interact with viral and host factors to modulate the efficiency of HEV replication. PMID:21775444

Replication of micro and nano surface geometries

DEFF Research Database (Denmark)

Hansen, Hans Nørgaard; Hocken, R.J.; Tosello, Guido

2011-01-01

The paper describes the state-of-the-art in replication of surface texture and topography at micro and nano scale. The description includes replication of surfaces in polymers, metals and glass. Three different main technological areas enabled by surface replication processes are presented......: manufacture of net-shape micro/nano surfaces, tooling (i.e. master making), and surface quality control (metrology, inspection). Replication processes and methods as well as the metrology of surfaces to determine the degree of replication are presented and classified. Examples from various application areas...... are given including replication for surface texture measurements, surface roughness standards, manufacture of micro and nano structured functional surfaces, replicated surfaces for optical applications (e.g. optical gratings), and process chains based on combinations of repeated surface replication steps....

Biphasic whole-cell synthesis of R-2-octanol with recycling of the ionic liquid

OpenAIRE

Dennewald, Danielle

2011-01-01

Whole-cell biocatalysis in biphasic systems permits the synthesis of inhibiting chiral alcohols if appropriate non-water miscible ionic liquids are used. Taking the asymmetric reduction of 2-octanone to R-2-octanol by a recombinant Escherichia coli as a model reaction, a detailed characterisation of the biocatalytic reaction was performed with [HMPL][NTF] as ionic liquid. This made the asymmetric synthesis of R-2-octanol in a simple batch at a conversion > 99 % and at an enantiomeric excess >...

Characterization of liver metastases: the efficacy of biphasic magnetic resonance imaging with ferucarbotran-enhancement

International Nuclear Information System (INIS)

Hong, H.S.; Byun, J.H.; Won, H.J.; Kim, K.W.; Lee, S.S.; Lee, M.G.; Yun, S.C.

2010-01-01

Aim: To retrospectively evaluate the efficacy of biphasic magnetic resonance imaging (MRI) of the liver with ferucarbotran-enhancement for the characterization of hepatic metastases. Materials and methods: Thirty-six patients underwent MRI of the liver with separate acquisition of double-contrast enhancement consisting of gadolinium and ferucarbotran. A total of 106 focal hepatic lesions (51 metastases, 31 cysts, 23 haemangiomas, and one eosinophilic abscess) were included. Two sets of MRI were analysed: (1) ferucarbotran set: ferucarbotran-enhanced T1-weighted (T1W) dynamic imaging combined with ferucarbotran-enhanced T2*-weighted (T2*W) delayed imaging and (2) double set: gadolinium-enhanced T1W dynamic imaging combined with ferucarbotran-enhanced T2*W delayed imaging. The diagnostic accuracy of the two sets was evaluated using alternative free-response receiver operating characteristic curve analysis. Sensitivity and specificity were compared using the McNemar test. The enhancement pattern of focal hepatic lesions was analysed on gadolinium and ferucarbotran-enhanced T1W dynamic imaging. Results: There was no significant difference in the accuracy of characterizing hepatic metastases between the two sets. Sensitivity and specificity were not significantly different between the sets (p > 0.05). Peripheral rim enhancement was exhibited in 57% of metastatic lesions on ferucarbotran-enhanced T1W dynamic imaging. The majority (96%) of hepatic haemangiomas demonstrated typical peripheral nodular enhancement with progression on ferucarbotran-enhanced T1W dynamic imaging and were easily differentiated from metastases. Conclusion: Biphasic MRI of the liver with ferucarbotran-enhancement alone provided comparable diagnostic efficacy to double-contrast MRI for the characterization of hepatic metastases.

A New Replication Norm for Psychology

Directory of Open Access Journals (Sweden)

Etienne P LeBel

2015-10-01

Full Text Available In recent years, there has been a growing concern regarding the replicability of findings in psychology, including a mounting number of prominent findings that have failed to replicate via high-powered independent replication attempts. In the face of this replicability “crisis of confidence”, several initiatives have been implemented to increase the reliability of empirical findings. In the current article, I propose a new replication norm that aims to further boost the dependability of findings in psychology. Paralleling the extant social norm that researchers should peer review about three times as many articles that they themselves publish per year, the new replication norm states that researchers should aim to independently replicate important findings in their own research areas in proportion to the number of original studies they themselves publish per year (e.g., a 4:1 original-to-replication studies ratio. I argue this simple approach could significantly advance our science by increasing the reliability and cumulative nature of our empirical knowledge base, accelerating our theoretical understanding of psychological phenomena, instilling a focus on quality rather than quantity, and by facilitating our transformation toward a research culture where executing and reporting independent direct replications is viewed as an ordinary part of the research process. To help promote the new norm, I delineate (1 how each of the major constituencies of the research process (i.e., funders, journals, professional societies, departments, and individual researchers can incentivize replications and promote the new norm and (2 any obstacles each constituency faces in supporting the new norm.

An amphipathic alpha-helix controls multiple roles of brome mosaic virus protein 1a in RNA replication complex assembly and function.

Directory of Open Access Journals (Sweden)

Ling Liu

2009-03-01

Full Text Available Brome mosaic virus (BMV protein 1a has multiple key roles in viral RNA replication. 1a localizes to perinuclear endoplasmic reticulum (ER membranes as a peripheral membrane protein, induces ER membrane invaginations in which RNA replication complexes form, and recruits and stabilizes BMV 2a polymerase (2a(Pol and RNA replication templates at these sites to establish active replication complexes. During replication, 1a provides RNA capping, NTPase and possibly RNA helicase functions. Here we identify in BMV 1a an amphipathic alpha-helix, helix A, and use NMR analysis to define its structure and propensity to insert in hydrophobic membrane-mimicking micelles. We show that helix A is essential for efficient 1a-ER membrane association and normal perinuclear ER localization, and that deletion or mutation of helix A abolishes RNA replication. Strikingly, mutations in helix A give rise to two dramatically opposite 1a function phenotypes, implying that helix A acts as a molecular switch regulating the intricate balance between separable 1a functions. One class of helix A deletions and amino acid substitutions markedly inhibits 1a-membrane association and abolishes ER membrane invagination, viral RNA template recruitment, and replication, but doubles the 1a-mediated increase in 2a(Pol accumulation. The second class of helix A mutations not only maintains efficient 1a-membrane association but also amplifies the number of 1a-induced membrane invaginations 5- to 8-fold and enhances viral RNA template recruitment, while failing to stimulate 2a(Pol accumulation. The results provide new insights into the pathways of RNA replication complex assembly and show that helix A is critical for assembly and function of the viral RNA replication complex, including its central role in targeting replication components and controlling modes of 1a action.

A simulation study of how simple mark-recapture methods can be combined with destructive sub-sampling to facilitate surveys of flying insects

DEFF Research Database (Denmark)

Nachman, Gøsta Støger; Skovgård, Henrik; Pedersen, Henrik Skovgård

2012-01-01

Mark-recapture techniques are used for studies of animal populations. With only three sampling occasions, both Bailey's triple-catch (BTC) and Jolly-Seber's (J-S) stochastic method can be applied. As marking and handling of fragile organisms may harm them, and thereby affect their chances of being...... to compare the subsampling method with the ordinary mark-recapture methods. Model-generated populations were sampled with and without subsampling to provide estimates of population size, loss, and dilution rates. The estimated parameters were compared with their true values to identify biases associated...... with the sampling methods, using 81 different combinations of population size, dilution rate, loss rate, and sampling effort. Each combination was replicated 1,000 times. In no cases did subsampling perform more poorly than the ordinary methods. J-S was slightly more accurate than BTC to estimate the population...

Centromere replication timing determines different forms of genomic instability in Saccharomyces cerevisiae checkpoint mutants during replication stress.

Science.gov (United States)

Feng, Wenyi; Bachant, Jeff; Collingwood, David; Raghuraman, M K; Brewer, Bonita J

2009-12-01

Yeast replication checkpoint mutants lose viability following transient exposure to hydroxyurea, a replication-impeding drug. In an effort to understand the basis for this lethality, we discovered that different events are responsible for inviability in checkpoint-deficient cells harboring mutations in the mec1 and rad53 genes. By monitoring genomewide replication dynamics of cells exposed to hydroxyurea, we show that cells with a checkpoint deficient allele of RAD53, rad53K227A, fail to duplicate centromeres. Following removal of the drug, however, rad53K227A cells recover substantial DNA replication, including replication through centromeres. Despite this recovery, the rad53K227A mutant fails to achieve biorientation of sister centromeres during recovery from hydroxyurea, leading to secondary activation of the spindle assembly checkpoint (SAC), aneuploidy, and lethal chromosome segregation errors. We demonstrate that cell lethality from this segregation defect could be partially remedied by reinforcing bipolar attachment. In contrast, cells with the mec1-1 sml1-1 mutations suffer from severely impaired replication resumption upon removal of hydroxyurea. mec1-1 sml1-1 cells can, however, duplicate at least some of their centromeres and achieve bipolar attachment, leading to abortive segregation and fragmentation of incompletely replicated chromosomes. Our results highlight the importance of replicating yeast centromeres early and reveal different mechanisms of cell death due to differences in replication fork progression.

Herpes simplex virus induces the marked up-regulation of the zinc finger transcriptional factor INSM1, which modulates the expression and localization of the immediate early protein ICP0

Directory of Open Access Journals (Sweden)

Kimura Hiroshi

2011-05-01

Full Text Available Abstract Background Herpes simplex viruses (HSVs rapidly shut off macromolecular synthesis in host cells. In contrast, global microarray analyses have shown that HSV infection markedly up-regulates a number of host cell genes that may play important roles in HSV-host cell interactions. To understand the regulatory mechanisms involved, we initiated studies focusing on the zinc finger transcription factor insulinoma-associated 1 (INSM1, a host cell protein markedly up-regulated by HSV infection. Results INSM1 gene expression in HSV-1-infected normal human epidermal keratinocytes increased at least 400-fold 9 h after infection; INSM1 promoter activity was also markedly stimulated. Expression and subcellular localization of the immediate early HSV protein ICP0 was affected by INSM1 expression, and chromatin immunoprecipitation (ChIP assays revealed binding of INSM1 to the ICP0 promoter. Moreover, the role of INSM1 in HSV-1 infection was further clarified by inhibition of HSV-1 replication by INSM1-specific siRNA. Conclusions The results suggest that INSM1 up-regulation plays a positive role in HSV-1 replication, probably by binding to the ICP0 promoter.

Pickering interfacial catalysis for biphasic systems: from emulsion design to green reactions.

Science.gov (United States)

Pera-Titus, Marc; Leclercq, Loïc; Clacens, Jean-Marc; De Campo, Floryan; Nardello-Rataj, Véronique

2015-02-09

Pickering emulsions are surfactant-free dispersions of two immiscible fluids that are kinetically stabilized by colloidal particles. For ecological reasons, these systems have undergone a resurgence of interest to mitigate the use of synthetic surfactants and solvents. Moreover, the use of colloidal particles as stabilizers provides emulsions with original properties compared to surfactant-stabilized emulsions, microemulsions, and micellar systems. Despite these specific advantages, the application of Pickering emulsions to catalysis has been rarely explored. This Minireview describes very recent examples of hybrid and composite amphiphilic materials for the design of interfacial catalysts in Pickering emulsions with special emphasis on their assets and challenges for industrially relevant biphasic reactions in fine chemistry, biofuel upgrading, and depollution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Inherent Asymmetry of DNA Replication.

Science.gov (United States)

Snedeker, Jonathan; Wooten, Matthew; Chen, Xin

2017-10-06

Semiconservative DNA replication has provided an elegant solution to the fundamental problem of how life is able to proliferate in a way that allows cells, organisms, and populations to survive and replicate many times over. Somewhat lost, however, in our admiration for this mechanism is an appreciation for the asymmetries that occur in the process of DNA replication. As we discuss in this review, these asymmetries arise as a consequence of the structure of the DNA molecule and the enzymatic mechanism of DNA synthesis. Increasing evidence suggests that asymmetries in DNA replication are able to play a central role in the processes of adaptation and evolution by shaping the mutagenic landscape of cells. Additionally, in eukaryotes, recent work has demonstrated that the inherent asymmetries in DNA replication may play an important role in the process of chromatin replication. As chromatin plays an essential role in defining cell identity, asymmetries generated during the process of DNA replication may play critical roles in cell fate decisions related to patterning and development.

Cutthroat trout virus as a surrogate in vitro infection model for testing inhibitors of hepatitis E virus replication

Science.gov (United States)

Debing, Yannick; Winton, James; Neyts, Johan; Dallmeier, Kai

2013-01-01

Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2′-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae.

Replication dynamics of the yeast genome.

Science.gov (United States)

Raghuraman, M K; Winzeler, E A; Collingwood, D; Hunt, S; Wodicka, L; Conway, A; Lockhart, D J; Davis, R W; Brewer, B J; Fangman, W L

2001-10-05

Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near mid-S phase. Rates of replication fork movement vary greatly from region to region in the genome. The two ends of each of the 16 chromosomes are highly correlated in their times of replication. This microarray approach is readily applicable to other organisms, including humans.

LHCb experience with LFC replication

CERN Document Server

Bonifazi, F; Perez, E D; D'Apice, A; dell'Agnello, L; Düllmann, D; Girone, M; Re, G L; Martelli, B; Peco, G; Ricci, P P; Sapunenko, V; Vagnoni, V; Vitlacil, D

2008-01-01

Database replication is a key topic in the framework of the LHC Computing Grid to allow processing of data in a distributed environment. In particular, the LHCb computing model relies on the LHC File Catalog, i.e. a database which stores information about files spread across the GRID, their logical names and the physical locations of all the replicas. The LHCb computing model requires the LFC to be replicated at Tier-1s. The LCG 3D project deals with the database replication issue and provides a replication service based on Oracle Streams technology. This paper describes the deployment of the LHC File Catalog replication to the INFN National Center for Telematics and Informatics (CNAF) and to other LHCb Tier-1 sites. We performed stress tests designed to evaluate any delay in the propagation of the streams and the scalability of the system. The tests show the robustness of the replica implementation with performance going much beyond the LHCb requirements.

LHCb experience with LFC replication

International Nuclear Information System (INIS)

Bonifazi, F; Carbone, A; D'Apice, A; Dell'Agnello, L; Re, G L; Martelli, B; Ricci, P P; Sapunenko, V; Vitlacil, D; Perez, E D; Duellmann, D; Girone, M; Peco, G; Vagnoni, V

2008-01-01

Database replication is a key topic in the framework of the LHC Computing Grid to allow processing of data in a distributed environment. In particular, the LHCb computing model relies on the LHC File Catalog, i.e. a database which stores information about files spread across the GRID, their logical names and the physical locations of all the replicas. The LHCb computing model requires the LFC to be replicated at Tier-1s. The LCG 3D project deals with the database replication issue and provides a replication service based on Oracle Streams technology. This paper describes the deployment of the LHC File Catalog replication to the INFN National Center for Telematics and Informatics (CNAF) and to other LHCb Tier-1 sites. We performed stress tests designed to evaluate any delay in the propagation of the streams and the scalability of the system. The tests show the robustness of the replica implementation with performance going much beyond the LHCb requirements

A feasible process for furfural production from the pre-hydrolysis liquor of corncob via biochar catalysts in a new biphasic system.

Science.gov (United States)

Deng, Aojie; Lin, Qixuan; Yan, Yuhuan; Li, Huiling; Ren, Junli; Liu, Chuanfu; Sun, Runcang

2016-09-01

A feasible approach was developed to produce furfural from the pre-hydrolysis liquor of corncob via biochar catalysts as the solid acid catalyst in a new biphasic system with dichloromethane (DCM) as the organic phase and the concentrated pre-hydrolysis liquor (CPHL) containing NaCl as the aqueous phase. The biochar catalyst possessing many acidity groups (SO3H, COOH and phenolic OH groups) was prepared by the carbonization and sulfonation process of the corncob hydrolyzed residue. The influence of the catalytic condition on furfural yield and selectivity was comparatively studied. It was found that 81.14% furfural yield and 83.0% furfural selectivity were obtained from CPHL containing 5wt% xylose using this biochar catalyst in the CPHL-NaCl/DCM biphasic system at 170°C for 60min. In addition, with the regeneration process, this catalyst displayed the high performance and excellent recyclability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influenza A Virus-Induced Expression of a GalNAc Transferase, GALNT3, via MicroRNAs Is Required for Enhanced Viral Replication.

Science.gov (United States)

Nakamura, Shoko; Horie, Masayuki; Daidoji, Tomo; Honda, Tomoyuki; Yasugi, Mayo; Kuno, Atsushi; Komori, Toshihisa; Okuzaki, Daisuke; Narimatsu, Hisashi; Nakaya, Takaaki; Tomonaga, Keizo

2016-02-15

Influenza A virus (IAV) affects the upper and lower respiratory tracts and rapidly induces the expression of mucins, which are common O-glycosylated proteins, on the epithelial surfaces of the respiratory tract. Although mucin production is associated with the inhibition of virus transmission as well as characteristic clinical symptoms, little is known regarding how mucins are produced on the surfaces of respiratory epithelial cells and how they affect IAV replication. In this study, we found that two microRNAs (miRNAs), miR-17-3p and miR-221, which target GalNAc transferase 3 (GALNT3) mRNA, are rapidly downregulated in human alveolar basal epithelial cells during the early stage of IAV infection. We demonstrated that the expression of GALNT3 mRNA is upregulated in an IAV replication-dependent fashion and leads to mucin production in bronchial epithelial cells. A lectin microarray analysis revealed that the stable expression of GALNT3 by human alveolar basal epithelial cells induces mucin-type O-glycosylation modifications similar to those present in IAV-infected cells, suggesting that GALNT3 promotes mucin-type O-linked glycosylation in IAV-infected cells. Notably, analyses using short interfering RNAs and miRNA mimics showed that GALNT3 knockdown significantly reduces IAV replication. Furthermore, IAV replication was markedly decreased in embryonic fibroblast cells obtained from galnt3-knockout mice. Interestingly, IAV-infected galnt3-knockout mice exhibited high mortality and severe pathological alterations in the lungs compared to those of wild-type mice. Our results demonstrate not only the molecular mechanism underlying rapid mucin production during IAV infection but also the contribution of O-linked glycosylation to the replication and propagation of IAV in lung cells. Viral infections that affect the upper or lower respiratory tracts, such as IAV, rapidly induce mucin production on the epithelial surfaces of respiratory cells. However, the details of how

Alendronate-Eluting Biphasic Calcium Phosphate (BCP Scaffolds Stimulate Osteogenic Differentiation

Directory of Open Access Journals (Sweden)

Sung Eun Kim

2015-01-01

Full Text Available Biphasic calcium phosphate (BCP scaffolds have been widely used in orthopedic and dental fields as osteoconductive bone substitutes. However, BCP scaffolds are not satisfactory for the stimulation of osteogenic differentiation and maturation. To enhance osteogenic differentiation, we prepared alendronate- (ALN- eluting BCP scaffolds. The coating of ALN on BCP scaffolds was confirmed by scanning electron microscopy (FE-SEM, energy-dispersive X-ray spectroscopy (EDS, and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR. An in vitro release study showed that release of ALN from ALN-eluting BCP scaffolds was sustained for up to 28 days. In vitro results revealed that MG-63 cells grown on ALN-eluting BCP scaffolds exhibited increased ALP activity and calcium deposition and upregulated gene expression of Runx2, ALP, OCN, and OPN compared with the BCP scaffold alone. Therefore, this study suggests that ALN-eluting BCP scaffolds have the potential to effectively stimulate osteogenic differentiation.

High-Resolution Replication Profiles Define the Stochastic Nature of Genome Replication Initiation and Termination

Directory of Open Access Journals (Sweden)

Michelle Hawkins

2013-11-01

Full Text Available Eukaryotic genome replication is stochastic, and each cell uses a different cohort of replication origins. We demonstrate that interpreting high-resolution Saccharomyces cerevisiae genome replication data with a mathematical model allows quantification of the stochastic nature of genome replication, including the efficiency of each origin and the distribution of termination events. Single-cell measurements support the inferred values for stochastic origin activation time. A strain, in which three origins were inactivated, confirmed that the distribution of termination events is primarily dictated by the stochastic activation time of origins. Cell-to-cell variability in origin activity ensures that termination events are widely distributed across virtually the whole genome. We propose that the heterogeneity in origin usage contributes to genome stability by limiting potentially deleterious events from accumulating at particular loci.

DNA replication and post-replication repair in U.V.-sensitive mouse neuroblastoma cells

International Nuclear Information System (INIS)

Lavin, M.F.; McCombe, P.; Kidson, C.

1976-01-01

Mouse neuroblastoma cells differentiated when grown in the absence of serum; differentiation was reversed on the addition of serum. Differentiated cells were more sensitive to U.V.-radiation than proliferating cells. Whereas addition of serum to differentiated neuroblastoma cells normally resulted in immediate, synchronous entry into S phase, irradiation just before the addition of serum resulted in a long delay in the onset of DNA replication. During this lag period, incorporated 3 H-thymidine appeared in the light density region of CsCl gradients, reflecting either repair synthesis or abortive replication. Post-replication repair (gap-filling) was found to be present in proliferating cells and at certain times in differentiated cells. It is suggested that the sensitivity of differentiated neuroblastoma cells to U.V.-radiation may have been due to ineffective post-replication repair or to deficiencies in more than one repair mechanism, with reduction in repair capacity beyond a critical threshold. (author)

Kinetic studies on the transesterification of sunflower oil with 1-butanol catalyzed by Rhizomucor miehei lipase in a biphasic aqueous-organic system

NARCIS (Netherlands)

Ilmi, Miftahul; Hommes, Arne; Winkelman, Jozef; Hidayat, C.; Heeres, Hero

2016-01-01

The kinetics of sunflower oil transesterification with 1-butanol using a homogeneous lipase (Rhizomucor miehei) in an aqueous-organic biphasic system were studied in a stirred batch reactor set-up. An initial screening study was performed to optimize relevant process conditions (enzyme

Lujan Mark-4

Energy Technology Data Exchange (ETDEWEB)

Mocko, Michael Jeffrey [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavorka, Lukas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Koehler, Paul E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-13

This is a review of Mark-IV target neutronics design. It involved the major redesign of the upper tier, offering harder neutron spectra for upper-tier FPs; a redesign of the high-resolution (HR) moderator; and a preservation of the rest of Mark-III features.

Minimal Marking: A Success Story

Science.gov (United States)

McNeilly, Anne

2014-01-01

The minimal-marking project conducted in Ryerson's School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The "minimal-marking" concept (Haswell, 1983), which requires…

Use of Respiratory Support in the Biphase Ventilation Airway Mode in the Newborn

Directory of Open Access Journals (Sweden)

S. N. Koval

2006-01-01

Full Text Available Biphasic positive airway pressure (BIPAP (also known as DuoPAP, BiLevel, BiVent, PCV+, SPAP is a mode of ventilation with cycling variations between two continuous positive airway pressure levels. It is a mixture of pressure controlled ventilation and spontaneous breathing, which is unrestricted in each phase of the respiratory cycle. The volume displacement caused by the difference between Phigh and Plow airway pressure level. The phase time ratio (PTR — the BIPAP frequency is calculated as the ratio between the durations of the two pressure phases, a PTR greater than 1:1 is called APRV (airway pressure release ventilation. In patients with ARDS maintained spontaneous breathing with BIPAP resulted in lower venous admixture and better arterial blood oxygenation as compared with A/C. Only a few studies with BIPAP have been performed in newborn and infants until now. We studied the use of BIPAP in newborn (body mass > 3kg and randomised 40 patients with respiratory failure for ventilation with BIPAP (n=20 or conventional mechanical ventilatory support (assist-control A/C — synchronised intermittent mandatory ventilation (SIMV (n=20. The Pediatric Risk of Mortality score (PRISM were collected for each patient. Fentanyl, diazepam, GABA were used as sedatives and adjusted in accordance with the Cook scale. We compared ventilatory parameters, information pertaining to pulmonary function and oxygen delivery, cardiac output, additional descriptors of organ system functions, duration and complications of ventilation and number and dosages of sedatives administered. All the patients that we intended to ventilate with BIPAP were successfully ventilated, we can conclude that biphasic ventilatory support suitable mode of ventilation for newborn with a decreased need of analgetics and sedatives than A/C. Finally, BIPAP is an a effective safe, and easy to use for personal mode of mechanical ventilatory support in newborn. 

New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

Energy Technology Data Exchange (ETDEWEB)

Rogers, R.D.; Bond, A.H.; Zhang, Jianhua [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Horwitz, P. [Argonne National Lab., IL (United States)

1995-12-31

Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.

DATABASE REPLICATION IN HETEROGENOUS PLATFORM

OpenAIRE

Hendro Nindito; Evaristus Didik Madyatmadja; Albert Verasius Dian Sano

2014-01-01

The application of diverse database technologies in enterprises today is increasingly a common practice. To provide high availability and survavibality of real-time information, a database replication technology that has capability to replicate databases under heterogenous platforms is required. The purpose of this research is to find the technology with such capability. In this research, the data source is stored in MSSQL database server running on Windows. The data will be replicated to MyS...

Overcoming natural replication barriers: differential helicase requirements.

Science.gov (United States)

Anand, Ranjith P; Shah, Kartik A; Niu, Hengyao; Sung, Patrick; Mirkin, Sergei M; Freudenreich, Catherine H

2012-02-01

DNA sequences that form secondary structures or bind protein complexes are known barriers to replication and potential inducers of genome instability. In order to determine which helicases facilitate DNA replication across these barriers, we analyzed fork progression through them in wild-type and mutant yeast cells, using 2-dimensional gel-electrophoretic analysis of the replication intermediates. We show that the Srs2 protein facilitates replication of hairpin-forming CGG/CCG repeats and prevents chromosome fragility at the repeat, whereas it does not affect replication of G-quadruplex forming sequences or a protein-bound repeat. Srs2 helicase activity is required for hairpin unwinding and fork progression. Also, the PCNA binding domain of Srs2 is required for its in vivo role of replication through hairpins. In contrast, the absence of Sgs1 or Pif1 helicases did not inhibit replication through structural barriers, though Pif1 did facilitate replication of a telomeric protein barrier. Interestingly, replication through a protein barrier but not a DNA structure barrier was modulated by nucleotide pool levels, illuminating a different mechanism by which cells can regulate fork progression through protein-mediated stall sites. Our analyses reveal fundamental differences in the replication of DNA structural versus protein barriers, with Srs2 helicase activity exclusively required for fork progression through hairpin structures.

Placental macrophage contact potentiates the complete replicative cycle of human cytomegalovirus in syncytiotrophoblast cells: role of interleukin-8 and transforming growth factor-beta1.

Science.gov (United States)

Bácsi, A; Aranyosi, J; Beck, Z; Ebbesen, P; Andirkó, I; Szabó, J; Lampé, L; Kiss, J; Gergely, L; Tóth, F D

1999-10-01

Although syncytiotrophoblast (ST) cells can be infected by human cytomegalovirus (HCMV), in vitro studies have indicated that ST cells do not support the complete viral reproductive cycle, or HCMV replication may occur in less than 3% of ST cells. The present study tested the possibility that placental macrophages might enhance activation of HCMV carried in ST cells and, further, that infected ST cells would be capable of transmitting virus to neighboring macrophages. For this purpose, we studied HCMV replication in ST cells grown alone or cocultured with uninfected placental macrophages. Our results demonstrated that HCMV gene expression in ST cells was markedly upregulated by coculture with macrophages, resulting in release of substantial amounts of infectious virus from HCMV-infected ST cells. After having become permissive for viral replication, ST cells delivered HCMV to the cocultured macrophages, as evidenced by detection of virus-specific antigens in these cells. The stimulatory effect of coculture on HCMV gene expression in ST cells was mediated by marked interleukin-8 (IL-8) and transforming growth factor-beta1 (TGF-beta1) release from macrophages, an effect caused by contact between the different placental cells. Our findings indicate an interactive role for the ST layer and placental macrophages in the dissemination of HCMV among placental tissue. Eventually, these interactions may contribute to the transmission of HCMV from mother to the fetus.

Exploiting replicative stress to treat cancer

DEFF Research Database (Denmark)

Dobbelstein, Matthias; Sørensen, Claus Storgaard

2015-01-01

DNA replication in cancer cells is accompanied by stalling and collapse of the replication fork and signalling in response to DNA damage and/or premature mitosis; these processes are collectively known as 'replicative stress'. Progress is being made to increase our understanding of the mechanisms...

Regulation of adeno-associated virus DNA replication by the cellular TAF-I/set complex.

Science.gov (United States)

Pegoraro, Gianluca; Marcello, Alessandro; Myers, Michael P; Giacca, Mauro

2006-07-01

The Rep proteins of the adeno-associated virus (AAV) are required for viral replication in the presence of adenovirus helper functions and as yet poorly characterized cellular factors. In an attempt to identify such factors, we purified Flag-Rep68-interacting proteins from human cell lysates. Several polypeptides were identified by mass spectrometry, among which was ANP32B, a member of the acidic nuclear protein 32 family which takes part in the formation of the template-activating factor I/Set oncoprotein (TAF-I/Set) complex. The N terminus of Rep was found to specifically bind the acidic domain of ANP32B; through this interaction, Rep was also able to recruit other members of the TAF-I/Set complex, including the ANP32A protein and the histone chaperone TAF-I/Set. Further experiments revealed that silencing of ANP32A and ANP32B inhibited AAV replication, while overexpression of all of the components of the TAF-I/Set complex increased de novo AAV DNA synthesis in permissive cells. Besides being the first indication that the TAF-I/Set complex participates in wild-type AAV replication, these findings have important implications for the generation of recombinant AAV vectors since overexpression of the TAF-I/Set components was found to markedly increase viral vector production.

Chromatin maturation depends on continued DNA-replication

International Nuclear Information System (INIS)

Schlaeger, E.J.; Puelm, W.; Knippers, R.

1983-01-01

The structure of [ 3 H]thymidine pulse-labeled chromatin in lymphocytes differs from that of non-replicating chromatin by several operational criteria which are related to the higher nuclease sensitivity of replicating chromatin. These structural features of replicating chromatin rapidly disappear when the [ 3 H]thymidine pulse is followed by a chase in the presence of an excess of non-radioactive thymidine. However, when the rate of DNA replication is reduced, as in cycloheximide-treated lymphocytes, chromatin maturation is retarded. No chromatin maturation is observed when nuclei from pulse-labeled lymphocytes are incubated in vitro in the absence of DNA precursors. In contrast, when these nuclei are incubated under conditions known to be optimal for DNA replication, the structure of replicating chromatin is efficiently converted to that of 'mature', non-replicating chromatin. The authors conclude that the properties of nascent DNA and/or the distance from the replication fork are important factors in chromatin maturation. (Auth.)

A unique epigenetic signature is associated with active DNA replication loci in human embryonic stem cells.

Science.gov (United States)

Li, Bing; Su, Trent; Ferrari, Roberto; Li, Jing-Yu; Kurdistani, Siavash K

2014-02-01

The cellular epigenetic landscape changes as pluripotent stem cells differentiate to somatic cells or when differentiated cells transform to a cancerous state. These epigenetic changes are commonly correlated with differences in gene expression. Whether active DNA replication is also associated with distinct chromatin environments in these developmentally and phenotypically diverse cell types has not been known. Here, we used BrdU-seq to map active DNA replication loci in human embryonic stem cells (hESCs), normal primary fibroblasts and a cancer cell line, and correlated these maps to the epigenome. In all cell lines, the majority of BrdU peaks were enriched in euchromatin and at DNA repetitive elements, especially at microsatellite repeats, and coincided with previously determined replication origins. The most prominent BrdU peaks were shared between all cells but a sizable fraction of the peaks were specific to each cell type and associated with cell type-specific genes. Surprisingly, the BrdU peaks that were common to all cell lines were associated with H3K18ac, H3K56ac, and H4K20me1 histone marks only in hESCs but not in normal fibroblasts or cancer cells. Depletion of the histone acetyltransferases for H3K18 and H3K56 dramatically decreased the number and intensity of BrdU peaks in hESCs. Our data reveal a unique epigenetic signature that distinguishes active replication loci in hESCs from normal somatic or malignant cells.

The Escherichia coli Tus-Ter replication fork barrier causes site-specific DNA replication perturbation in yeast

DEFF Research Database (Denmark)

Larsen, Nicolai B; Sass, Ehud; Suski, Catherine

2014-01-01

Replication fork (RF) pausing occurs at both 'programmed' sites and non-physiological barriers (for example, DNA adducts). Programmed RF pausing is required for site-specific DNA replication termination in Escherichia coli, and this process requires the binding of the polar terminator protein, Tus...... as a versatile, site-specific, heterologous DNA replication-perturbing system, with a variety of potential applications....

Mark Stock | NREL

Science.gov (United States)

Stock Mark Stock Scientific Visualization Specialist Mark.Stock@nrel.gov | 303-275-4174 Dr. Stock , virtual reality, parallel computing, and manipulation of large spatial data sets. As an artist, he creates . Stock built the SUNLIGHT artwork that is installed on the Webb Building in downtown Denver. In addition

Zika virus preferentially replicates in the female reproductive tract after vaginal inoculation of rhesus macaques.

Science.gov (United States)

Carroll, Timothy; Lo, Ming; Lanteri, Marion; Dutra, Joseph; Zarbock, Katie; Silveira, Paola; Rourke, Tracy; Ma, Zhong-Min; Fritts, Linda; O'Connor, Shelby; Busch, Michael; Miller, Christopher J

2017-07-01

Zika virus (ZIKV) is a mosquito-transmitted virus that can cause severe defects in an infected fetus. ZIKV is also transmitted by sexual contact, although the relative importance of sexual transmission is unclear. To better understand the role of sexual transmission in ZIKV pathogenesis, a nonhuman primate (NHP) model of vaginal transmission was developed. ZIKV was readily transmitted to mature cycling female rhesus macaque (RM) by vaginal inoculation with 104-106 plaque-forming units (PFU). However, there was variability in susceptibility between the individual RM with 1->8 vaginal inoculations required to establish infection. After treatment with Depoprovera, a widely used contraceptive progestin, two RM that initially resisted 8 vaginal ZIKV inoculations became infected after one ZIKV inoculation. Thus, Depoprovera seemed to enhance susceptibility to vaginal ZIKV transmission. Unexpectedly, the kinetics of virus replication and dissemination after intravaginal ZIKV inoculation were markedly different from RM infected with ZIKV by subcutaneous (SQ) virus inoculation. Several groups have reported that after SQ ZIKV inoculation vRNA is rapidly detected in blood plasma with vRNA less common in urine and saliva and only rarely detected in female reproductive tract (FRT) secretions. In contrast, in vaginally inoculated RM, plasma vRNA is delayed for several days and ZIKV replication in, and vRNA shedding from, the FRT was found in all 6 animals. Further, after intravaginal transmission ZIKV RNA shedding from FRT secretions was detected before or simultaneously with plasma vRNA, and persisted for at least as long. Thus, ZIKV replication in the FRT was independent of, and often preceded virus replication in the tissues contributing to plasma vRNA. These results support the conclusion that ZIKV preferentially replicates in the FRT after vaginal transmission, but not after SQ transmission, and raise the possibility that there is enhanced fetal infection and pathology

Subtype-Specific Differences in Gag-Protease-Driven Replication Capacity Are Consistent with Intersubtype Differences in HIV-1 Disease Progression.

Science.gov (United States)

Kiguoya, Marion W; Mann, Jaclyn K; Chopera, Denis; Gounder, Kamini; Lee, Guinevere Q; Hunt, Peter W; Martin, Jeffrey N; Ball, T Blake; Kimani, Joshua; Brumme, Zabrina L; Brockman, Mark A; Ndung'u, Thumbi

2017-07-01

There are marked differences in the spread and prevalence of HIV-1 subtypes worldwide, and differences in clinical progression have been reported. However, the biological reasons underlying these differences are unknown. Gag-protease is essential for HIV-1 replication, and Gag-protease-driven replication capacity has previously been correlated with disease progression. We show that Gag-protease replication capacity correlates significantly with that of whole isolates ( r = 0.51; P = 0.04), indicating that Gag-protease is a significant contributor to viral replication capacity. Furthermore, we investigated subtype-specific differences in Gag-protease-driven replication capacity using large well-characterized cohorts in Africa and the Americas. Patient-derived Gag-protease sequences were inserted into an HIV-1 NL4-3 backbone, and the replication capacities of the resulting recombinant viruses were measured in an HIV-1-inducible reporter T cell line by flow cytometry. Recombinant viruses expressing subtype C Gag-proteases exhibited substantially lower replication capacities than those expressing subtype B Gag-proteases ( P identified Gag residues 483 and 484, located within the Alix-binding motif involved in virus budding, as major contributors to subtype-specific replicative differences. In East African cohorts, we observed a hierarchy of Gag-protease-driven replication capacities, i.e., subtypes A/C differences in disease progression. We thus hypothesize that the lower Gag-protease-driven replication capacity of subtypes A and C slows disease progression in individuals infected with these subtypes, which in turn leads to greater opportunity for transmission and thus increased prevalence of these subtypes. IMPORTANCE HIV-1 subtypes are unevenly distributed globally, and there are reported differences in their rates of disease progression and epidemic spread. The biological determinants underlying these differences have not been fully elucidated. Here, we show that

Enzymatic recognition of DNA replication origins

International Nuclear Information System (INIS)

Stayton, M.M.; Bertsch, L.; Biswas, S.

1983-01-01

In this paper we discuss the process of recognition of the complementary-strand origin with emphasis on RNA polymerase action in priming M13 DNA replication, the role of primase in G4 DNA replication, and the function of protein n, a priming protein, during primosome assembly. These phage systems do not require several of the bacterial DNA replication enzymes, particularly those involved in the regulation of chromosome copy number of the initiatiion of replication of duplex DNA. 51 references, 13 figures, 1 table

Surface Microstructure Replication in Injection Moulding

DEFF Research Database (Denmark)

Hansen, Hans Nørgaard; Arlø, Uffe Rolf

2005-01-01

topography is transcribed onto the plastic part through complex mechanisms. This replication however, is not perfect, and the replication quality depends on the plastic material properties, the topography itself, and the process conditions. This paper describes and discusses an investigation of injection...... moulding of surface microstructures. Emphasis is put on the ability to replicate surface microstructures under normal injection moulding conditions, notably with low cost materials at low mould temperatures. The replication of surface microstructures in injection moulding has been explored...... for Polypropylene at low mould temperatures. The process conditions were varied over the recommended process window for the material. The geometry of the obtained structures was analyzed. Evidence suggests that step height replication quality depends linearly on structure width in a certain range. Further...

The eukaryotic translation initiation factor 3 subunit E binds to classical swine fever virus NS5A and facilitates viral replication.

Science.gov (United States)

Liu, Xiaofeng; Wang, Xiaoyu; Wang, Qian; Luo, Mingyang; Guo, Huancheng; Gong, Wenjie; Tu, Changchun; Sun, Jinfu

2018-02-01

Classical swine fever virus (CSFV) NS5A protein is a multifunctional protein, playing critical roles in viral RNA replication, translation and assembly. To further explore its functions in viral replication, interaction of NS5A with host factors was assayed using a his-tag "pull down" assay coupled with shotgun LC-MS/MS. Host protein translation initiation factor 3 subunit E was identified as a binding partner of NS5A, and confirmed by co-immunoprecipitation and co-localization analysis. Overexpression of eIF3E markedly enhanced CSFV genomic replication, viral protein expression and production of progeny virus, and downregulation of eIF3E by siRNA significantly decreased viral proliferation in PK-15 cells. Luciferase reporter assay showed an enhancement of translational activity of the internal ribosome entry site of CSFV by eIF3E and a decrease in cellular translation by NS5A. These data indicate that eIF3E plays an important role in CSFV replication, thereby identifying it as a potential target for inhibition of the virus. Copyright © 2017 Elsevier Inc. All rights reserved.

Irradiation induces a biphasic expression of pro-inflammatory cytokines in the lung

International Nuclear Information System (INIS)

Ruebe, C.E.; Wilfert, F.; Palm, J.; Burdak-Rothkamm, S.; Ruebe, C.; Koenig, J.; Liu Li; Schuck, A.; Willich, N.

2004-01-01

Background and purpose: the precise pathophysiological mechanisms of radiation-induced lung injury are poorly understood, but have been shown to correlate with dysregulation of different cytokines. The purpose of this study was to evaluate the time course of the pro-inflammatory cytokines tumor necrosis factor-(TNF-)α, interleukin-(IL)-1α and IL-6 after whole-lung irradiation. Material and methods: the thoraces of C57BL/6J mice were irradiated with 12 Gy. Treated and control mice were sacrificed at 0.5, 1, 3, 6, 12, 24, 48, 72 h, 1, 2, 4, 8, 16, and 24 weeks post irradiation (p.i.). Real-time multiplex RT-PCR (reverse transcriptase polmyerase chain reaction) was established to evaluate the expression of TNF-α, IL-1α and IL-6 in the lung tissue of the mice. For histological analysis, lung tissue sections were stained by hematoxylin and eosin. Results: multiplex RT-PCR analysis revealed a biphasic expression of these pro-inflammatory cytokines in the lung tissue after irradiation. After an initial increase at 1 h p.i. for TNF-α and at 6 h p.i. for IL-1α and IL-6, the mRNA expression of these pro-inflammatory cytokines returned to basal levels (48 h, 72 h, 1 week, 2 weeks p.i.). During the pneumonic phase, TNF-α, IL-1α and IL-6 were significantly elevated and revealed their maximum at 8 weeks p.i. Histopathologic evaluation of the lung sections obtained within 4 weeks p.i. revealed only minor lung damage in 5-30% of the lung tissue. By contrast, at 8, 16, and 24 weeks p.i., 70-90% of the lung tissue revealed histopathologically detectable organizing alveolitis. Conclusion: irradiation induces a biphasic expression of pro-inflammatory cytokines in the lung. The initial transitory cytokine response occurred within the first hours after lung irradiation with no detectable histopathologic alterations. The second, more persistent cytokine elevation coincided with the onset of histologically discernible organizing acute pneumonitis. (orig.)

Irradiation induces a biphasic expression of pro-inflammatory cytokines in the lung

Energy Technology Data Exchange (ETDEWEB)

Ruebe, C.E.; Wilfert, F.; Palm, J.; Burdak-Rothkamm, S.; Ruebe, C. [Dept. of Radiotherapy - Radiooncology, Saarland Univ., Homburg/Saar (Germany); Koenig, J. [Inst. of Medical Biometrics, Epidemiology and Medical Informatics, Saarland Univ., Homburg/Saar (Germany); Liu Li [Dept. of Radiotherapy - Radiooncology, Saarland Univ., Homburg/Saar (Germany); Cancer Center, Union Hospital Tongji Medical Coll., Huazhong Univ. of Science and Technology, Wuhan (China); Schuck, A.; Willich, N. [Dept. of Radiotherapy - Radiooncology, Univ. of Muenster (Germany)

2004-07-01

Background and purpose: the precise pathophysiological mechanisms of radiation-induced lung injury are poorly understood, but have been shown to correlate with dysregulation of different cytokines. The purpose of this study was to evaluate the time course of the pro-inflammatory cytokines tumor necrosis factor-(TNF-){alpha}, interleukin-(IL)-1{alpha} and IL-6 after whole-lung irradiation. Material and methods: the thoraces of C57BL/6J mice were irradiated with 12 Gy. Treated and control mice were sacrificed at 0.5, 1, 3, 6, 12, 24, 48, 72 h, 1, 2, 4, 8, 16, and 24 weeks post irradiation (p.i.). Real-time multiplex RT-PCR (reverse transcriptase polmyerase chain reaction) was established to evaluate the expression of TNF-{alpha}, IL-1{alpha} and IL-6 in the lung tissue of the mice. For histological analysis, lung tissue sections were stained by hematoxylin and eosin. Results: multiplex RT-PCR analysis revealed a biphasic expression of these pro-inflammatory cytokines in the lung tissue after irradiation. After an initial increase at 1 h p.i. for TNF-{alpha} and at 6 h p.i. for IL-1{alpha} and IL-6, the mRNA expression of these pro-inflammatory cytokines returned to basal levels (48 h, 72 h, 1 week, 2 weeks p.i.). During the pneumonic phase, TNF-{alpha}, IL-1{alpha} and IL-6 were significantly elevated and revealed their maximum at 8 weeks p.i. Histopathologic evaluation of the lung sections obtained within 4 weeks p.i. revealed only minor lung damage in 5-30% of the lung tissue. By contrast, at 8, 16, and 24 weeks p.i., 70-90% of the lung tissue revealed histopathologically detectable organizing alveolitis. Conclusion: irradiation induces a biphasic expression of pro-inflammatory cytokines in the lung. The initial transitory cytokine response occurred within the first hours after lung irradiation with no detectable histopathologic alterations. The second, more persistent cytokine elevation coincided with the onset of histologically discernible organizing acute

Minority games, evolving capitals and replicator dynamics

International Nuclear Information System (INIS)

Galla, Tobias; Zhang, Yi-Cheng

2009-01-01

We discuss a simple version of the minority game (MG) in which agents hold only one strategy each, but in which their capitals evolve dynamically according to their success and in which the total trading volume varies in time accordingly. This feature is known to be crucial for MGs to reproduce stylized facts of real market data. The stationary states and phase diagram of the model can be computed, and we show that the ergodicity breaking phase transition common for MGs, and marked by a divergence of the integrated response, is present also in this simplified model. An analogous majority game turns out to be relatively void of interesting features, and the total capital is found to diverge in time. Introducing a restraining force leads to a model akin to the replicator dynamics of evolutionary game theory, and we demonstrate that here a different type of phase transition is observed. Finally we briefly discuss the relation of this model with one strategy per player to more sophisticated minority games with dynamical capitals and several trading strategies per agent

Replication Protein A (RPA) Phosphorylation Prevents RPA Association with Replication Centers

OpenAIRE

Vassin, Vitaly M.; Wold, Marc S.; Borowiec, James A.

2004-01-01

Mammalian replication protein A (RPA) undergoes DNA damage-dependent phosphorylation at numerous sites on the N terminus of the RPA2 subunit. To understand the functional significance of RPA phosphorylation, we expressed RPA2 variants in which the phosphorylation sites were converted to aspartate (RPA2D) or alanine (RPA2A). Although RPA2D was incorporated into RPA heterotrimers and supported simian virus 40 DNA replication in vitro, the RPA2D mutant was selectively unable to associate with re...

Variance Swap Replication: Discrete or Continuous?

Directory of Open Access Journals (Sweden)

Fabien Le Floc’h

2018-02-01

Full Text Available The popular replication formula to price variance swaps assumes continuity of traded option strikes. In practice, however, there is only a discrete set of option strikes traded on the market. We present here different discrete replication strategies and explain why the continuous replication price is more relevant.

Sodium lauryl sulfate impedes drug release from zinc-crosslinked alginate beads: switching from enteric coating release into biphasic profiles.

Science.gov (United States)

Taha, Mutasem O; Nasser, Wissam; Ardakani, Adel; Alkhatib, Hatim S

2008-02-28

The aim of this research is to investigate the effects of sodium lauryl sulfate (SLS) on ionotropically cross-linked alginate beads. Different levels of SLS were mixed with sodium alginate and chlorpheniramine maleate (as loaded model drug). The resulting viscous solutions were dropped onto aqueous solutions of zinc or calcium ions for ionotropic curing. The generated beads were assessed by their drug releasing profiles, infrared and differential scanning colorimetery (DSC) traits. SLS was found to exert profound concentration-dependent impacts on the characteristics of zinc-crosslinked alginate beads such that moderate modifications in the levels of SLS switched drug release from enteric coating-like behavior to a biphasic release modifiable to sustained-release by the addition of minute amounts of xanthan gum. Calcium cross-linking failed to reproduce the same behavior, probably due to the mainly ionic nature of calcium-carboxylate bonds compared to the coordinate character of their zinc-carboxylate counterparts. Apparently, moderate levels of SLS repel water penetration into the beads, and therefore minimize chlorpheniramine release. However, higher SLS levels seem to discourage polymeric cross-linking and therefore allow biphasic drug release.

Spindle-cell squamous carcinoma of the esophagus: a tumor with biphasic morphology

International Nuclear Information System (INIS)

Agha, F.P.; Keren, D.F.

1985-01-01

Spindle-cell squamous carcinoma of the esophagus is a rare malignant tumor. It is characterized by a large bulky mass in the middle third of the esophagus with a lobulated surface and local expansion of the esophagus. This lesion may be pedunculated and cause relatively little obstruction despite its bulk. The current view, based on ultrastructure and immunohistochemical evidence, has confirmed that the sarcomatous component of the squamous cell carcinoma originates from mesenchymal metaplasia of squamous cells. On the basis of this evidence and clinical behavior, it seems appropriate to consider carcinosarcoma and pseudosarcoma as equivalents and as variants of squamous cell carcinoma. Four patients with spindle-cell squamous carcinoma, an unusual subset of squamous carcinoma, are described, and the salient radiographic and pathologic features of this disorder's distinctive biphasic morphology are discussed

Biphasic oxidation of oxy-hemoglobin in bloodstains.

Directory of Open Access Journals (Sweden)

Rolf H Bremmer

Full Text Available BACKGROUND: In forensic science, age determination of bloodstains can be crucial in reconstructing crimes. Upon exiting the body, bloodstains transit from bright red to dark brown, which is attributed to oxidation of oxy-hemoglobin (HbO(2 to met-hemoglobin (met-Hb and hemichrome (HC. The fractions of HbO(2, met-Hb and HC in a bloodstain can be used for age determination of bloodstains. In this study, we further analyze the conversion of HbO(2 to met-Hb and HC, and determine the effect of temperature and humidity on the conversion rates. METHODOLOGY: The fractions of HbO(2, met-Hb and HC in a bloodstain, as determined by quantitative analysis of optical reflectance spectra (450-800 nm, were measured as function of age, temperature and humidity. Additionally, Optical Coherence Tomography around 1300 nm was used to confirm quantitative spectral analysis approach. CONCLUSIONS: The oxidation rate of HbO(2 in bloodstains is biphasic. At first, the oxidation of HbO(2 is rapid, but slows down after a few hours. These oxidation rates are strongly temperature dependent. However, the oxidation of HbO(2 seems to be independent of humidity, whereas the transition of met-Hb into HC strongly depends on humidity. Knowledge of these decay rates is indispensable for translating laboratory results into forensic practice, and to enable bloodstain age determination on the crime scene.

Regulation of the demographic structure in isomorphic biphasic life cycles at the spatial fine scale.

Directory of Open Access Journals (Sweden)

Vasco Manuel Nobre de Carvalho da Silva Vieira

Full Text Available Isomorphic biphasic algal life cycles often occur in the environment at ploidy abundance ratios (Haploid:Diploid different from 1. Its spatial variability occurs within populations related to intertidal height and hydrodynamic stress, possibly reflecting the niche partitioning driven by their diverging adaptation to the environment argued necessary for their prevalence (evolutionary stability. Demographic models based in matrix algebra were developed to investigate which vital rates may efficiently generate an H:D variability at a fine spatial resolution. It was also taken into account time variation and type of life strategy. Ploidy dissimilarities in fecundity rates set an H:D spatial structure miss-fitting the ploidy fitness ratio. The same happened with ploidy dissimilarities in ramet growth whenever reproductive output dominated the population demography. Only through ploidy dissimilarities in looping rates (stasis, breakage and clonal growth did the life cycle respond to a spatially heterogeneous environment efficiently creating a niche partition. Marginal locations were more sensitive than central locations. Related results have been obtained experimentally and numerically for widely different life cycles from the plant and animal kingdoms. Spore dispersal smoothed the effects of ploidy dissimilarities in fertility and enhanced the effects of ploidy dissimilarities looping rates. Ploidy dissimilarities in spore dispersal could also create the necessary niche partition, both over the space and time dimensions, even in spatial homogeneous environments and without the need for conditional differentiation of the ramets. Fine scale spatial variability may be the key for the prevalence of isomorphic biphasic life cycles, which has been neglected so far.

Surface microstructure replication in injection molding

DEFF Research Database (Denmark)

Theilade, Uffe Arlø; Hansen, Hans Nørgaard

2006-01-01

topography is transcribed onto the plastic part through complex mechanisms. This replication, however, is not perfect, and the replication quality depends on the plastic material properties, the topography itself, and the process conditions. This paper describes and discusses an investigation of injection...... molding of surface microstructures. The fundamental problem of surface microstructure replication has been studied. The research is based on specific microstructures as found in lab-on-a-chip products and on rough surfaces generated from EDM (electro discharge machining) mold cavities. Emphasis is put...... on the ability to replicate surface microstructures under normal injection-molding conditions, i.e., with commodity materials within typical process windows. It was found that within typical process windows the replication quality depends significantly on several process parameters, and especially the mold...

Effect of Ganoderma lucidum on pollen-induced biphasic nasal blockage in a guinea pig model of allergic rhinitis.

Science.gov (United States)

Mizutani, Nobuaki; Nabe, Takeshi; Shimazu, Masaji; Yoshino, Shin; Kohno, Shigekatsu

2012-03-01

Ganoderma lucidum (GL), an oriental medical mushroom, has been used in Asia for the prevention and treatment of a variety of diseases. However, the effect of GL on allergic rhinitis has not been well defined. The current study describes the inhibitory effect of GL on the biphasic nasal blockage and nasal hyperresponsiveness induced by repeated antigen challenge in a guinea pig model of allergic rhinitis. Intranasally sensitized guinea pigs were repeatedly challenged by inhalation of Japanese cedar pollen once every week. Ganoderma lucidum was orally administered once daily for 8 weeks from the time before the first challenge. The treatment with GL dose-dependently inhibited the early and late phase nasal blockage at the fifth to ninth antigen challenges. Furthermore, nasal hyperresponsiveness to intranasally applied leukotriene D₄ on 2 days after the eighth antigen challenge was also inhibited by the treatment with GL. However, Cry j 1-specific IgE antibody production was not affected by the treatment. In conclusion, we demonstrated that the pollen-induced biphasic nasal blockage and nasal hyperresponsiveness were suppressed by the daily treatment with GL in the guinea pig model of allergic rhinitis. These results suggest that GL may be a useful therapeutic drug for treating patients with allergic rhinitis. Copyright © 2011 John Wiley & Sons, Ltd.

Activation of human herpesvirus replication by apoptosis.

Science.gov (United States)

Prasad, Alka; Remick, Jill; Zeichner, Steven L

2013-10-01

A central feature of herpesvirus biology is the ability of herpesviruses to remain latent within host cells. Classically, exposure to inducing agents, like activating cytokines or phorbol esters that stimulate host cell signal transduction events, and epigenetic agents (e.g., butyrate) was thought to end latency. We recently showed that Kaposi's sarcoma-associated herpesvirus (KSHV, or human herpesvirus-8 [HHV-8]) has another, alternative emergency escape replication pathway that is triggered when KSHV's host cell undergoes apoptosis, characterized by the lack of a requirement for the replication and transcription activator (RTA) protein, accelerated late gene kinetics, and production of virus with decreased infectivity. Caspase-3 is necessary and sufficient to initiate the alternative replication program. HSV-1 was also recently shown to initiate replication in response to host cell apoptosis. These observations suggested that an alternative apoptosis-triggered replication program might be a general feature of herpesvirus biology and that apoptosis-initiated herpesvirus replication may have clinical implications, particularly for herpesviruses that almost universally infect humans. To explore whether an alternative apoptosis-initiated replication program is a common feature of herpesvirus biology, we studied cell lines latently infected with Epstein-Barr virus/HHV-4, HHV-6A, HHV-6B, HHV-7, and KSHV. We found that apoptosis triggers replication for each HHV studied, with caspase-3 being necessary and sufficient for HHV replication. An alternative apoptosis-initiated replication program appears to be a common feature of HHV biology. We also found that commonly used cytotoxic chemotherapeutic agents activate HHV replication, which suggests that treatments that promote apoptosis may lead to activation of latent herpesviruses, with potential clinical significance.

Cutthroat trout virus as a surrogate in vitro infection model for testing inhibitors of hepatitis E virus replication.

Science.gov (United States)

Debing, Yannick; Winton, James; Neyts, Johan; Dallmeier, Kai

2013-10-01

Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2'-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae. Copyright © 2013 Elsevier B.V. All rights reserved.

Evolution of Replication Machines

Science.gov (United States)

Yao, Nina Y.; O'Donnell, Mike E.

2016-01-01

The machines that decode and regulate genetic information require the translation, transcription and replication pathways essential to all living cells. Thus, it might be expected that all cells share the same basic machinery for these pathways that were inherited from the primordial ancestor cell from which they evolved. A clear example of this is found in the translation machinery that converts RNA sequence to protein. The translation process requires numerous structural and catalytic RNAs and proteins, the central factors of which are homologous in all three domains of life, bacteria, archaea and eukarya. Likewise, the central actor in transcription, RNA polymerase, shows homology among the catalytic subunits in bacteria, archaea and eukarya. In contrast, while some “gears” of the genome replication machinery are homologous in all domains of life, most components of the replication machine appear to be unrelated between bacteria and those of archaea and eukarya. This review will compare and contrast the central proteins of the “replisome” machines that duplicate DNA in bacteria, archaea and eukarya, with an eye to understanding the issues surrounding the evolution of the DNA replication apparatus. PMID:27160337

DNA replication origins—where do we begin?

Science.gov (United States)

Prioleau, Marie-Noëlle; MacAlpine, David M.

2016-01-01

For more than three decades, investigators have sought to identify the precise locations where DNA replication initiates in mammalian genomes. The development of molecular and biochemical approaches to identify start sites of DNA replication (origins) based on the presence of defining and characteristic replication intermediates at specific loci led to the identification of only a handful of mammalian replication origins. The limited number of identified origins prevented a comprehensive and exhaustive search for conserved genomic features that were capable of specifying origins of DNA replication. More recently, the adaptation of origin-mapping assays to genome-wide approaches has led to the identification of tens of thousands of replication origins throughout mammalian genomes, providing an unprecedented opportunity to identify both genetic and epigenetic features that define and regulate their distribution and utilization. Here we summarize recent advances in our understanding of how primary sequence, chromatin environment, and nuclear architecture contribute to the dynamic selection and activation of replication origins across diverse cell types and developmental stages. PMID:27542827

Solving the Blood-Brain Barrier Challenge for the Effective Treatment of HIV Replication in the Central Nervous System.

Science.gov (United States)

Bertrand, Luc; Nair, Madhavan; Toborek, Michal

2016-01-01

Recent decades mark a great progress in the treatment of HIV infection. What was once a deadly disease is now a chronic infection. However, HIV-infected patients are prone to develop comorbidities, which severely affect their daily functions. For example, a large population of patients develop a variety of neurological and cognitive complications, called HIV associated neurological disorders (HAND). Despite efficient repression of viral replication in the periphery, evidence shows that the virus can remain active in the central nervous system (CNS). This low level of replication is believed to result in a progression of neurocognitive dysfunction in infected individuals. Insufficient viral inhibition in the brain results from the inability of several treatment drugs in crossing the blood-brain barrier (BBB) and reaching therapeutic concentrations in the CNS. The current manuscript discusses several strategies that are being developed to enable therapeutics to cross the BBB, including bypassing BBB, inhibition of efflux transporters, the use of active transporters present at the BBB, and nanotechnology. The increased concentration of therapeutics in the CNS is desirable to prevent viral replication; however, potential side effects of anti-retroviral drugs need also to be taken into consideration.

Chromosomal DNA replication of Vicia faba cells

International Nuclear Information System (INIS)

Ikushima, Takaji

1976-01-01

The chromosomal DNA replication of higher plant cells has been investigated by DNA fiber autoradiography. The nuclear DNA fibers of Vicia root meristematic cells are organized into many tandem arrays of replication units or replicons which exist as clusters with respect to replication. DNA is replicated bidirectionally from the initiation points at the average rate of 0.15 μm/min at 20 0 C, and the average interinitiation interval is about 16 μm. The manner of chromosomal DNA replication in this higher plant is similar to that found in other eukaryotic cells at a subchromosomal level. (auth.)

Surface micro topography replication in injection moulding

DEFF Research Database (Denmark)

Arlø, Uffe Rolf

Thermoplastic injection moulding is a widely used industrial process that involves surface generation by replication. The surface topography of injection moulded plastic parts can be important for aesthetical or technical reasons. With the emergence of microengineering and nanotechnology additional...... importance of surface topography follows. In general the replication is not perfect and the topography of the plastic part differs from the inverse topography of the mould cavity. It is desirable to be able to control the degree of replication perfection or replication quality. This requires an understanding...... of the physical mechanisms of replication. Such understanding can lead to improved process design and facilitate in-line process quality control with respect to surface properties. The purpose of the project is to identify critical factors that affect topography replication quality and to obtain an understanding...

DNA replication in ultraviolet light irradiated Chinese hamster cells: the nature of replicon inhibition and post-replication repair

International Nuclear Information System (INIS)

Doniger, J.

1978-01-01

DNA replication in ultraviolet light irradiated Chinese hamster cells was studied using techniques of DNA fiber autoradiography and alkaline sucrose sedimentation. Bidirectionally growing replicons were observed in the autoradiograms independent of the irradiation conditions. After a dose of 5 J/m 2 at 254 nm the rate of fork progression was the same as in unirradiated cells, while the rate of replication was reduced by 50%. After a dose of 10J/m 2 the rate of fork progression was reduced 40%, while the replication rate was only 25% of normal. Therefore, at low doses of ultraviolet light irradiation, the inhibition of DNA replication is due to reduction in the number of functioning replicons, while at higher doses the rate of fork progression is also slowed. Those replicons which no longer function after irradiation are blocked in fork movement rather than replicon initiation. After irradiation, pulse label was first incorporated into short nascent strands, the average size of which was approximately equal to the distance between pyrimidine dimers. Under conditions where post-replication repair occurs these short strands were eventually joined into larger pieces. Finally, the data show that slowing post-replication repair with caffeine does not slow fork movement. The results presented here support the post-replication repair model of 'gapped synthesis' and rule out a major role for 'replicative bypass'. (author)

Dynamics of Escherichia coli Chromosome Segregation during Multifork Replication

DEFF Research Database (Denmark)

Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

2007-01-01

Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division, the chro......Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division......, the chromosomes contain multiple replication forks and must be segregated while this complex pattern of replication is still ongoing. Here, we show that replication and segregation continue in step, starting at the origin and progressing to the replication terminus. Thus, early-replicated markers on the multiple......-branched chromosomes continue to separate soon after replication to form separate protonucleoids, even though they are not segregated into different daughter cells until later generations. The segregation pattern follows the pattern of chromosome replication and does not follow the cell division cycle. No extensive...

Nonequilibrium Entropic Bounds for Darwinian Replicators

Directory of Open Access Journals (Sweden)

Jordi Piñero

2018-01-01

Full Text Available Life evolved on our planet by means of a combination of Darwinian selection and innovations leading to higher levels of complexity. The emergence and selection of replicating entities is a central problem in prebiotic evolution. Theoretical models have shown how populations of different types of replicating entities exclude or coexist with other classes of replicators. Models are typically kinetic, based on standard replicator equations. On the other hand, the presence of thermodynamical constraints for these systems remain an open question. This is largely due to the lack of a general theory of statistical methods for systems far from equilibrium. Nonetheless, a first approach to this problem has been put forward in a series of novel developements falling under the rubric of the extended second law of thermodynamics. The work presented here is twofold: firstly, we review this theoretical framework and provide a brief description of the three fundamental replicator types in prebiotic evolution: parabolic, malthusian and hyperbolic. Secondly, we employ these previously mentioned techinques to explore how replicators are constrained by thermodynamics. Finally, we comment and discuss where further research should be focused on.

Rescue from replication stress during mitosis.

Science.gov (United States)

Fragkos, Michalis; Naim, Valeria

2017-04-03

Genomic instability is a hallmark of cancer and a common feature of human disorders, characterized by growth defects, neurodegeneration, cancer predisposition, and aging. Recent evidence has shown that DNA replication stress is a major driver of genomic instability and tumorigenesis. Cells can undergo mitosis with under-replicated DNA or unresolved DNA structures, and specific pathways are dedicated to resolving these structures during mitosis, suggesting that mitotic rescue from replication stress (MRRS) is a key process influencing genome stability and cellular homeostasis. Deregulation of MRRS following oncogene activation or loss-of-function of caretaker genes may be the cause of chromosomal aberrations that promote cancer initiation and progression. In this review, we discuss the causes and consequences of replication stress, focusing on its persistence in mitosis as well as the mechanisms and factors involved in its resolution, and the potential impact of incomplete replication or aberrant MRRS on tumorigenesis, aging and disease.

Personality and Academic Motivation: Replication, Extension, and Replication

Science.gov (United States)

Jones, Martin H.; McMichael, Stephanie N.

2015-01-01

Previous work examines the relationships between personality traits and intrinsic/extrinsic motivation. We replicate and extend previous work to examine how personality may relate to achievement goals, efficacious beliefs, and mindset about intelligence. Approximately 200 undergraduates responded to the survey with a 150 participants replicating…

Biphasic insulin-releasing effect of BTS 67 582 in rats.

Science.gov (United States)

Storey, D A; Bailey, C J

1998-12-01

BTS 67 582 (1,1-dimethyl-2(2-morpholinophenyl)guanidine fumarate) is being developed as a short-acting anti-diabetic insulin secretagogue. The effect of BTS 67 582 on the phasic pattern of insulin release was assessed in anaesthetized normal rats by measuring arterial plasma insulin concentrations while arterial glucose concentrations were fixed at 6, 8.5 and 12.5 mM. Intravenous BTS 67 582 (10 mg kg(-1)) induced an immediate but transient increase in insulin concentrations which declined by 10 min (first phase). This was followed by a smaller but sustained increase in insulin concentrations (second phase). The increment from basal to peak insulin release (0-2 min) was independent of glucose, but the first phase was maintained for longer and the second phase was greater at the highest concentration of glucose (12.5 mM). BTS 67 582 also extended the first-phase insulin response to a standard intravenous glucose challenge and enhanced the rate of glucose disappearance by approximately 12%. Thus BTS 67 582 causes biphasic stimulation of insulin release and augments the insulin-releasing effect of glucose.

DNA replication origins-where do we begin?

Science.gov (United States)

Prioleau, Marie-Noëlle; MacAlpine, David M

2016-08-01

For more than three decades, investigators have sought to identify the precise locations where DNA replication initiates in mammalian genomes. The development of molecular and biochemical approaches to identify start sites of DNA replication (origins) based on the presence of defining and characteristic replication intermediates at specific loci led to the identification of only a handful of mammalian replication origins. The limited number of identified origins prevented a comprehensive and exhaustive search for conserved genomic features that were capable of specifying origins of DNA replication. More recently, the adaptation of origin-mapping assays to genome-wide approaches has led to the identification of tens of thousands of replication origins throughout mammalian genomes, providing an unprecedented opportunity to identify both genetic and epigenetic features that define and regulate their distribution and utilization. Here we summarize recent advances in our understanding of how primary sequence, chromatin environment, and nuclear architecture contribute to the dynamic selection and activation of replication origins across diverse cell types and developmental stages. © 2016 Prioleau and MacAlpine; Published by Cold Spring Harbor Laboratory Press.

Pattern replication by confined dewetting

NARCIS (Netherlands)

Harkema, S.; Schäffer, E.; Morariu, M.D.; Steiner, U

2003-01-01

The dewetting of a polymer film in a confined geometry was employed in a pattern-replication process. The instability of dewetting films is pinned by a structured confining surface, thereby replicating its topographic pattern. Depending on the surface energy of the confining surface, two different

Production of Phytotoxic Metabolite Using Biphasic Fermentation System from Strain C1136 of Lasiodiplodia pseudotheobromae, a Potential Bioherbicidal Agent

OpenAIRE

Charles Oluwaseun ADETUNJI; Julius Kola OLOKE; Gandham PRASAD; Moses ABALAKA; Emenike Onyebum IROKANULO

2017-01-01

Formulation of effective and environmental friendly bioherbicides depends on the type of fermentation medium used for the production of phytotoxic metabolites. The effect of biomass, colony forming unit and the phytotoxic metabolite produced from the biphasic fermentation was carried out, while the phytotoxic metabolite was tested in vivo and in-vitro on Echinochola crus-galli and dicotyledonous Chromolaena odorata. The mutant strain of Lasiodiplodia pseudotheobromae C1136 (Lp90) produced th...

Parametrised Constants and Replication for Spatial Mobility

DEFF Research Database (Denmark)

Hüttel, Hans; Haagensen, Bjørn

2009-01-01

Parametrised replication and replication are common ways of expressing infinite computation in process calculi. While parametrised constants can be encoded using replication in the π-calculus, this changes in the presence of spatial mobility as found in e.g. the distributed π- calculus...... of the distributed π-calculus with parametrised constants and replication are incomparable. On the other hand, we shall see that there exists a simple encoding of recursion in mobile ambients....

Adenovirus sequences required for replication in vivo.

OpenAIRE

Wang, K; Pearson, G D

1985-01-01

We have studied the in vivo replication properties of plasmids carrying deletion mutations within cloned adenovirus terminal sequences. Deletion mapping located the adenovirus DNA replication origin entirely within the first 67 bp of the adenovirus inverted terminal repeat. This region could be further subdivided into two functional domains: a minimal replication origin and an adjacent auxillary region which boosted the efficiency of replication by more than 100-fold. The minimal origin occup...

Biphasic {sup 68}Ga-PSMA-HBED-CC-PET/CT in patients with recurrent and high-risk prostate carcinoma

Energy Technology Data Exchange (ETDEWEB)

Sahlmann, Carsten-Oliver; Meller, Birgit; Bouter, Caroline; Meller, Johannes [University Medical Center Goettingen, Department of Nuclear Medicine, Goettingen (Germany); Ritter, Christian Oliver; Lotz, Joachim [University Medical Center Goettingen, Department of Diagnostic and Interventional Radiology, Goettingen (Germany); Stroebel, Philipp [University Medical Center Goettingen, Department of Pathology, Goettingen (Germany); Trojan, Lutz; Hijazi, Sameh [University Medical Center Goettingen, Department of Urology, Goettingen (Germany)

2016-05-15

Binding of {sup 68}Ga-PSMA-HBED-CC ({sup 68}Ga-PSMA) at prostate cancer (PC) cells increases over time. A biphasic protocol may help separating benign from tumor lesions. The aim of this study was the retrospective evaluation of a diagnostic incremental value of a dual-time point (biphasic) {sup 68}Ga-PSMA-PET/CT in patients with prostate cancer. Retrospective analysis of 35 consecutive patients (49-78 years, median 71) with newly diagnosed PC (12/35) or recurrence of PC (23/35). PET/CT (Gemini TF16, Philips) was acquired 1 h and 3 h p. i. of 140-392 MBq (300 MBq median) {sup 68}Ga-PSMA, followed by a diagnostic contrast CT. PET findings were correlated with histology or unequivocal CT findings. Semiquantitative PET data (SUVmax, SUV mean) were acquired and target-to-background-ratios (T/B-ratio) were calculated for benign and malign lesions for both time points. Size of lymph nodes (LN) on diagnostic CT was recorded. Statistical analysis was performed for assessment of significant changes of semiquantitative PET-parameters over time and for correlation of size and uptake of lymph nodes. One hundred and four lesions were evaluated. Sixty lesions were referenced by histology or unequivocal CT findings, including eight (13.3 %) histopathologically benign lymph nodes, 12 (20 %) histopathologically lymph node metastases, 12 (20 %) primary tumors, three (5 %) local recurrences, and 25 (41.7 %) bone metastases. Forty-four lesions were axillary LN with normal CT-appearance. Benign lesions had significantly lower SUVmax and T/B-ratios compared with malignant findings. Malign lesions showed a significant increase of both parameters over time compared to benign findings. There was no correlation between LN size and SUVmax. The sensitivity, specificity, the positive predictive value and negative predictive value of PET/CT regarding pelvic LN was 94 %, 99 %, 89 %, and 99.5 %, respectively. In contrast to benign tissues, the uptake of proven tumor lesions increases on {sup 68

Pneumococcal Replicative State in Relation to its Adherence Capacity to A549-cell Line: A Preliminary in vitro Analysis

Directory of Open Access Journals (Sweden)

Mohd Desa, M. N.

2011-01-01

Full Text Available This study was to compare the replication capacity of pneumococcal isolates (serotypes 1, 7F, 19F and 23F with their adherence pattern to monolayer cells (A549. For standardization purposes, all isolates showed a normal growth curve in both bacteriological (THB + 0.5% yeast extract with and without 2% FBS and cell culture media (RPMI + 2% FBS. In the former media, a shorter lag phase was observed for isolate serotypes 1 and 7F in presence of serum while in the later; growth yield was lower for all isolates with stationary phase approaching OD600 of 0.01 as compared to 1.0 in bacteriological media. In the replicative analysis at different growth phases of the isolates in cell culture media, growth capacity at 3 h post-incubation was frequently twice as that at 1 h, and that at early-log phase was frequently higher than that at mid-log phase at both post-incubation times. Adherence was frequently the least at early-log phase although the isolates were in the most active state of replication to increase the number of pneumococcal cells to adhere. At mid- and late-log phases, pneumococcal adherence was frequently higher although the replication was reduced. This study marks the potential correlation between pneumococcal growth fitness and adherence capacity whereby the later may not be superior during the early growth phase.

Aqueous biphasic systems involving alkylsulfate-based ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Deive, Francisco J. [Instituto de Tecnologia Quimica e Biologica, UNL, Av. Republica, Apartado 127, 2780-901 Oeiras (Portugal); Department of Chemical Engineering, University of Vigo, P.O. Box 36310, Vigo (Spain); Rodriguez, Ana [Department of Chemical Engineering, University of Vigo, P.O. Box 36310, Vigo (Spain); Marrucho, Isabel M., E-mail: imarrucho@itqb.unl.pt [Instituto de Tecnologia Quimica e Biologica, UNL, Av. Republica, Apartado 127, 2780-901 Oeiras (Portugal); Rebelo, Luis P.N. [Instituto de Tecnologia Quimica e Biologica, UNL, Av. Republica, Apartado 127, 2780-901 Oeiras (Portugal)

2011-11-15

Highlights: > K{sub 3}PO{sub 4}, K{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, and (NH{sub 4}){sub 2}SO{sub 4} act as phase promoter in aqueous solutions of ILs. > Remarkable influence of alkyl-chain length on solubility curves of alkylsulfate-based ILs. > Merchuck correlation was used for describing these systems. > {Delta}S{sub hyd} and Hofmeister series were used to discuss the different salting out effects. - Abstract: The specific effects of K{sub 3}PO{sub 4}, K{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, and (NH{sub 4}){sub 2}SO{sub 4}, as high charge-density inorganic salts and thus inducers of the formation of aqueous biphasic systems (ABS) containing several ethyl-methylimidazolium alkylsulfate ionic liquids, C{sub 2}MIM C{sub n}SO{sub 4} (n = 2, 4, 6, or 8), have been assessed at T = 298.15 K. The results are analyzed in the light of the Hofmeister series. The influence of different alkyl chain lengths in the anion, together with the ability of the selected inorganic salts to induce the formation of ABS, is discussed. Phase diagrams have been determined through turbidimetry, including tie lines assignments from mass phase ratios according to the lever - arm rule. The Merchuck equation was satisfactorily used to correlate the solubility curve.

Mammalian RAD52 Functions in Break-Induced Replication Repair of Collapsed DNA Replication Forks.

Science.gov (United States)

Sotiriou, Sotirios K; Kamileri, Irene; Lugli, Natalia; Evangelou, Konstantinos; Da-Ré, Caterina; Huber, Florian; Padayachy, Laura; Tardy, Sebastien; Nicati, Noemie L; Barriot, Samia; Ochs, Fena; Lukas, Claudia; Lukas, Jiri; Gorgoulis, Vassilis G; Scapozza, Leonardo; Halazonetis, Thanos D

2016-12-15

Human cancers are characterized by the presence of oncogene-induced DNA replication stress (DRS), making them dependent on repair pathways such as break-induced replication (BIR) for damaged DNA replication forks. To better understand BIR, we performed a targeted siRNA screen for genes whose depletion inhibited G1 to S phase progression when oncogenic cyclin E was overexpressed. RAD52, a gene dispensable for normal development in mice, was among the top hits. In cells in which fork collapse was induced by oncogenes or chemicals, the Rad52 protein localized to DRS foci. Depletion of Rad52 by siRNA or knockout of the gene by CRISPR/Cas9 compromised restart of collapsed forks and led to DNA damage in cells experiencing DRS. Furthermore, in cancer-prone, heterozygous APC mutant mice, homozygous deletion of the Rad52 gene suppressed tumor growth and prolonged lifespan. We therefore propose that mammalian RAD52 facilitates repair of collapsed DNA replication forks in cancer cells. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Suppression of Poxvirus Replication by Resveratrol.

Science.gov (United States)

Cao, Shuai; Realegeno, Susan; Pant, Anil; Satheshkumar, Panayampalli S; Yang, Zhilong

2017-01-01

Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV), the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression.

Suppression of Poxvirus Replication by Resveratrol

Directory of Open Access Journals (Sweden)

Shuai Cao

2017-11-01

Full Text Available Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV, the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression.

Crinivirus replication and host interactions

Directory of Open Access Journals (Sweden)

Zsofia A Kiss

2013-05-01

Full Text Available Criniviruses comprise one of the genera within the family Closteroviridae. Members in this family are restricted to the phloem and rely on whitefly vectors of the genera Bemisia and/or Trialeurodes for plant-to-plant transmission. All criniviruses have bipartite, positive-sense ssRNA genomes, although there is an unconfirmed report of one having a tripartite genome. Lettuce infectious yellows virus (LIYV is the type species of the genus, the best studied so far of the criniviruses and the first for which a reverse genetics system was available. LIYV RNA 1 encodes for proteins predicted to be involved in replication, and alone is competent for replication in protoplasts. Replication results in accumulation of cytoplasmic vesiculated membranous structures which are characteristic of most studied members of the Closteroviridae. These membranous structures, often referred to as BYV-type vesicles, are likely sites of RNA replication. LIYV RNA 2 is replicated in trans when co-infecting cells with RNA 1, but is temporally delayed relative to RNA1. Efficient RNA 2 replication also is dependent on the RNA 1-encoded RNA binding protein, P34. No LIYV RNA 2-encoded proteins have been shown to affect RNA replication, but at least four, CP, CPm, Hsp70h, and p59 are virion structural components and CPm is a determinant of whitefly transmissibility. Roles of other LIYV RNA 2-encoded proteins are largely as yet unknown, but P26 is a non-virion protein that accumulates in cells as characteristic plasmalemma deposits which in plants are localized within phloem parenchyma and companion cells over plasmodesmata connections to sieve elements. The two remaining crinivirus-conserved RNA 2-encoded proteins are P5 and P9. P5 is 39 amino acid protein and is encoded at the 5’ end of RNA 2 as ORF1 and is part of the hallmark closterovirus gene array. The orthologous gene in BYV has been shown to play a role in cell-to-cell movement and indicated to be localized to the

Jnk2 effects on tumor development, genetic instability and replicative stress in an oncogene-driven mouse mammary tumor model.

Directory of Open Access Journals (Sweden)

Peila Chen

2010-05-01

Full Text Available Oncogenes induce cell proliferation leading to replicative stress, DNA damage and genomic instability. A wide variety of cellular stresses activate c-Jun N-terminal kinase (JNK proteins, but few studies have directly addressed the roles of JNK isoforms in tumor development. Herein, we show that jnk2 knockout mice expressing the Polyoma Middle T Antigen transgene developed mammary tumors earlier and experienced higher tumor multiplicity compared to jnk2 wildtype mice. Lack of jnk2 expression was associated with higher tumor aneuploidy and reduced DNA damage response, as marked by fewer pH2AX and 53BP1 nuclear foci. Comparative genomic hybridization further confirmed increased genomic instability in PyV MT/jnk2-/- tumors. In vitro, PyV MT/jnk2-/- cells underwent replicative stress and cell death as evidenced by lower BrdU incorporation, and sustained chromatin licensing and DNA replication factor 1 (CDT1 and p21(Waf1 protein expression, and phosphorylation of Chk1 after serum stimulation, but this response was not associated with phosphorylation of p53 Ser15. Adenoviral overexpression of CDT1 led to similar differences between jnk2 wildtype and knockout cells. In normal mammary cells undergoing UV induced single stranded DNA breaks, JNK2 localized to RPA (Replication Protein A coated strands indicating that JNK2 responds early to single stranded DNA damage and is critical for subsequent recruitment of DNA repair proteins. Together, these data support that JNK2 prevents replicative stress by coordinating cell cycle progression and DNA damage repair mechanisms.

Effector-Triggered Self-Replication in Coupled Subsystems.

Science.gov (United States)

Komáromy, Dávid; Tezcan, Meniz; Schaeffer, Gaël; Marić, Ivana; Otto, Sijbren

2017-11-13

In living systems processes like genome duplication and cell division are carefully synchronized through subsystem coupling. If we are to create life de novo, similar control over essential processes such as self-replication need to be developed. Here we report that coupling two dynamic combinatorial subsystems, featuring two separate building blocks, enables effector-mediated control over self-replication. The subsystem based on the first building block shows only self-replication, whereas that based on the second one is solely responsive toward a specific external effector molecule. Mixing the subsystems arrests replication until the effector molecule is added, resulting in the formation of a host-effector complex and the liberation of the building block that subsequently engages in self-replication. The onset, rate and extent of self-replication is controlled by the amount of effector present. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Addressing the "Replication Crisis": Using Original Studies to Design Replication Studies with Appropriate Statistical Power.

Science.gov (United States)

Anderson, Samantha F; Maxwell, Scott E

2017-01-01

Psychology is undergoing a replication crisis. The discussion surrounding this crisis has centered on mistrust of previous findings. Researchers planning replication studies often use the original study sample effect size as the basis for sample size planning. However, this strategy ignores uncertainty and publication bias in estimated effect sizes, resulting in overly optimistic calculations. A psychologist who intends to obtain power of .80 in the replication study, and performs calculations accordingly, may have an actual power lower than .80. We performed simulations to reveal the magnitude of the difference between actual and intended power based on common sample size planning strategies and assessed the performance of methods that aim to correct for effect size uncertainty and/or bias. Our results imply that even if original studies reflect actual phenomena and were conducted in the absence of questionable research practices, popular approaches to designing replication studies may result in a low success rate, especially if the original study is underpowered. Methods correcting for bias and/or uncertainty generally had higher actual power, but were not a panacea for an underpowered original study. Thus, it becomes imperative that 1) original studies are adequately powered and 2) replication studies are designed with methods that are more likely to yield the intended level of power.

Stoichiometric implications of a biphasic life cycle.

Science.gov (United States)

Tiegs, Scott D; Berven, Keith A; Carmack, Douglas J; Capps, Krista A

2016-03-01

Animals mediate flows of elements and energy in ecosystems through processes such as nutrient sequestration in body tissues, and mineralization through excretion. For taxa with biphasic life cycles, the dramatic shifts in anatomy and physiology that occur during ontogeny are expected to be accompanied by changes in body and excreta stoichiometry, but remain little-explored, especially in vertebrates. Here we tested stoichiometric hypotheses related to the bodies and excreta of the wood frog (Lithobates sylvaticus) across life stages and during larval development. Per-capita rates of nitrogen (N) and phosphorus (P) excretion varied widely during larval ontogeny, followed unimodal patterns, and peaked midway through development (Taylor-Kollros stages XV and XII, respectively). Larval mass did not increase steadily during development but peaked at stage XVII and declined until the termination of the experiment at stage XXII. Mass-specific N and P excretion rates of the larvae decreased exponentially during development. When coupled with population-biomass estimates, population-level excretion rates were greatest at stages VIII-X. Percent carbon (C), N, and C:N of body tissue showed weak trends across major life stages; body P and C:P, however, increased sixfold during development from egg to adult. Our results demonstrate that intraspecific ontogenic changes in nutrient contents of excretion and body tissues can be significant, and that N and P are not always excreted proportionally throughout life cycles. These results highlight the dynamic roles that species play in ecosystems, and how the morphological and physiological changes that accompany ontogeny can influence ecosystem-level processes.

Replication and robustness in developmental research.

Science.gov (United States)

Duncan, Greg J; Engel, Mimi; Claessens, Amy; Dowsett, Chantelle J

2014-11-01

Replications and robustness checks are key elements of the scientific method and a staple in many disciplines. However, leading journals in developmental psychology rarely include explicit replications of prior research conducted by different investigators, and few require authors to establish in their articles or online appendices that their key results are robust across estimation methods, data sets, and demographic subgroups. This article makes the case for prioritizing both explicit replications and, especially, within-study robustness checks in developmental psychology. It provides evidence on variation in effect sizes in developmental studies and documents strikingly different replication and robustness-checking practices in a sample of journals in developmental psychology and a sister behavioral science-applied economics. Our goal is not to show that any one behavioral science has a monopoly on best practices, but rather to show how journals from a related discipline address vital concerns of replication and generalizability shared by all social and behavioral sciences. We provide recommendations for promoting graduate training in replication and robustness-checking methods and for editorial policies that encourage these practices. Although some of our recommendations may shift the form and substance of developmental research articles, we argue that they would generate considerable scientific benefits for the field. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

How many bootstrap replicates are necessary?

Science.gov (United States)

Pattengale, Nicholas D; Alipour, Masoud; Bininda-Emonds, Olaf R P; Moret, Bernard M E; Stamatakis, Alexandros

2010-03-01

Phylogenetic bootstrapping (BS) is a standard technique for inferring confidence values on phylogenetic trees that is based on reconstructing many trees from minor variations of the input data, trees called replicates. BS is used with all phylogenetic reconstruction approaches, but we focus here on one of the most popular, maximum likelihood (ML). Because ML inference is so computationally demanding, it has proved too expensive to date to assess the impact of the number of replicates used in BS on the relative accuracy of the support values. For the same reason, a rather small number (typically 100) of BS replicates are computed in real-world studies. Stamatakis et al. recently introduced a BS algorithm that is 1 to 2 orders of magnitude faster than previous techniques, while yielding qualitatively comparable support values, making an experimental study possible. In this article, we propose stopping criteria--that is, thresholds computed at runtime to determine when enough replicates have been generated--and we report on the first large-scale experimental study to assess the effect of the number of replicates on the quality of support values, including the performance of our proposed criteria. We run our tests on 17 diverse real-world DNA--single-gene as well as multi-gene--datasets, which include 125-2,554 taxa. We find that our stopping criteria typically stop computations after 100-500 replicates (although the most conservative criterion may continue for several thousand replicates) while producing support values that correlate at better than 99.5% with the reference values on the best ML trees. Significantly, we also find that the stopping criteria can recommend very different numbers of replicates for different datasets of comparable sizes. Our results are thus twofold: (i) they give the first experimental assessment of the effect of the number of BS replicates on the quality of support values returned through BS, and (ii) they validate our proposals for

Hierarchical Fabrication of Engineered Vascularized Bone Biphasic Constructs via Dual 3D Bioprinting: Integrating Regional Bioactive Factors into Architectural Design.

Science.gov (United States)

Cui, Haitao; Zhu, Wei; Nowicki, Margaret; Zhou, Xuan; Khademhosseini, Ali; Zhang, Lijie Grace

2016-09-01

A biphasic artificial vascularized bone construct with regional bioactive factors is presented using dual 3D bioprinting platform technique, thereby forming a large functional bone grafts with organized vascular networks. Biocompatible mussel-inspired chemistry and "thiol-ene" click reaction are used to regionally immobilize bioactive factors during construct fabrication for modulating or improving cellular events. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Non‐Canonical Replication Initiation: You’re Fired!

Directory of Open Access Journals (Sweden)

Bazilė Ravoitytė

2017-01-01

Full Text Available The division of prokaryotic and eukaryotic cells produces two cells that inherit a perfect copy of the genetic material originally derived from the mother cell. The initiation of canonical DNA replication must be coordinated to the cell cycle to ensure the accuracy of genome duplication. Controlled replication initiation depends on a complex interplay of cis‐acting DNA sequences, the so‐called origins of replication (ori, with trans‐acting factors involved in the onset of DNA synthesis. The interplay of cis‐acting elements and trans‐acting factors ensures that cells initiate replication at sequence‐specific sites only once, and in a timely order, to avoid chromosomal endoreplication. However, chromosome breakage and excessive RNA:DNA hybrid formation can cause breakinduced (BIR or transcription‐initiated replication (TIR, respectively. These non‐canonical replication events are expected to affect eukaryotic genome function and maintenance, and could be important for genome evolution and disease development. In this review, we describe the difference between canonical and non‐canonical DNA replication, and focus on mechanistic differences and common features between BIR and TIR. Finally, we discuss open issues on the factors and molecular mechanisms involved in TIR.

Factors influencing microinjection molding replication quality

Science.gov (United States)

Vera, Julie; Brulez, Anne-Catherine; Contraires, Elise; Larochette, Mathieu; Trannoy-Orban, Nathalie; Pignon, Maxime; Mauclair, Cyril; Valette, Stéphane; Benayoun, Stéphane

2018-01-01

In recent years, there has been increased interest in producing and providing high-precision plastic parts that can be manufactured by microinjection molding: gears, pumps, optical grating elements, and so on. For all of these applications, the replication quality is essential. This study has two goals: (1) fabrication of high-precision parts using the conventional injection molding machine; (2) identification of robust parameters that ensure production quality. Thus, different technological solutions have been used: cavity vacuuming and the use of a mold coated with DLC or CrN deposits. AFM and SEM analyses were carried out to characterize the replication profile. The replication quality was studied in terms of the process parameters, coated and uncoated molds and crystallinity of the polymer. Specific studies were processed to quantify the replicability of injection molded parts (ABS, PC and PP). Analysis of the Taguchi experimental designs permits prioritization of the impact of each parameter on the replication quality. A discussion taking into account these new parameters and the thermal and spreading properties on the coatings is proposed. It appeared that, in general, increasing the mold temperature improves the molten polymer fill in submicron features except for the steel insert (for which the presence of a vacuum is the most important factor). Moreover, the DLC coating was the best coating to increase the quality of the replication. This result could be explained by the lower thermal diffusivity of this coating. We noted that the viscosity of the polymers is not a primordial factor of the replication quality.

Realistic Vascular Replicator for TAVR Procedures.

Science.gov (United States)

Rotman, Oren M; Kovarovic, Brandon; Sadasivan, Chander; Gruberg, Luis; Lieber, Baruch B; Bluestein, Danny

2018-04-13

Transcatheter aortic valve replacement (TAVR) is an over-the-wire procedure for treatment of severe aortic stenosis (AS). TAVR valves are conventionally tested using simplified left heart simulators (LHS). While those provide baseline performance reliably, their aortic root geometries are far from the anatomical in situ configuration, often overestimating the valves' performance. We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angiograms were monitored pre- and post-TAVR. A St. Jude mechanical valve was tested as a reference that is less affected by the AS anatomy. Results in the Replicator of both valves were compared to the performance in a commercial ISO-compliant LHS. The AS anatomy in the Replicator resulted in a significant decrease of the TAVR valve performance relative to the simplified LHS, with EOA and transvalvular pressures comparable to clinical data. Minor change was seen in the mechanical valve performance. The Replicator showed to be an effective platform for TAVR testing. Unlike a simplified geometric anatomy LHS, it conservatively provides clinically-relevant outcomes and complement it. The Replicator can be most valuable for testing new valves under challenging patient anatomies, physicians training, and procedural planning.

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

Directory of Open Access Journals (Sweden)

Andrew Bogdan

2009-04-01

Full Text Available We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leaving the organic product separate from the aqueous by-products. Furthermore, the microreactor oxidized a wide range of alcohols and remained active in excess of 100 trials without showing any loss of catalytic activity.

Metabolomics reveals metabolic targets and biphasic responses in breast cancer cells treated by curcumin alone and in association with docetaxel.

Directory of Open Access Journals (Sweden)

Mathilde Bayet-Robert

Full Text Available BACKGROUND: Curcumin (CUR has deserved extensive research due to its anti-inflammatory properties, of interest in human diseases including cancer. However, pleiotropic even paradoxical responses of tumor cells have been reported, and the mechanisms of action of CUR remain uncompletely elucidated. METHODOLOGY/PRINCIPAL FINDINGS: (1H-NMR spectroscopy-based metabolomics was applied to get novel insight into responses of MCF7 and MDA-MB-231 breast cancer cells to CUR alone, and MCF7 cells to CUR in cotreatment with docetaxel (DTX. In both cell types, a major target of CUR was glutathione metabolism. Total glutathione (GSx increased at low dose CUR (≤ 10 mg.l(-1-28 µM- (up to +121% in MCF7 cells, P<0.01, and +138% in MDA-MB-231 cells, P<0.01, but decreased at high dose (≥ 25 mg.l(-1 -70 µM- (-49%, in MCF7 cells, P<0.02, and -56% in MDA-MB-231 cells, P<0.025. At high dose, in both cell types, GSx-related metabolites decreased, including homocystein, creatine and taurine (-60 to -80%, all, P<0.05. Together with glutathione-S-transferase actvity, data established that GSx biosynthesis was upregulated at low dose, and GSx consumption activated at high dose. Another major target, in both cell types, was lipid metabolism involving, at high doses, accumulation of polyunsaturated and total free fatty acids (between ×4.5 and ×11, P<0.025, and decrease of glycerophospho-ethanolamine and -choline (about -60%, P<0.025. Multivariate statistical analyses showed a metabolic transition, even a biphasic behavior of some metabolites including GSx, between low and high doses. In addition, CUR at 10 mg.l(-1 in cotreatment with DTX induced modifications in glutathione metabolism, lipid metabolism, and glucose utilization. Some of these changes were biphasic depending on the duration of exposure to CUR. CONCLUSIONS/SIGNIFICANCE: Metabolomics reveals major metabolic targets of CUR in breast cancer cells, and biphasic responses that challenge the widely accepted

Biphasic influence of dexamethasone exposure on embryonic vertebrate skeleton development

International Nuclear Information System (INIS)

Cheng, Xin; Chen, Jian-long; Ma, Zheng-lai; Zhang, Zhao-long; Lv, Shun; Mai, Dong-mei; Liu, Jia-jia; Chuai, Manli; Lee, Kenneth Ka Ho; Wan, Chao; Yang, Xuesong

2014-01-01

in mesenchymal cell mass treated by low concentration of Dex. Mmp-13 expression was obviously up-regulated by Dex in both mesenchymal cells and primary chondrocyte cultures. And Col10a1 expression was also increased by Dex exposure in chondrocyte. In summary, we have revealed that different concentrations of Dex exposure during early gestation could exert a biphasic effect on vertebrate skeletal development. - Highlights: • Chick embryos occurred shortening of the long bone following Dex exposure. • Dex suppressed chondrocytes proliferation and promoted apoptosis. • Dex exposure decreased ALP production and up-regulated Runx-2 and Mmp-13. • Dex exhibited biphasic effects on chondrogenic proliferation and nodule formation. • The hypertrophy and ossification were accelerated by Dex both in vivo and in vitro

Biphasic influence of dexamethasone exposure on embryonic vertebrate skeleton development

Energy Technology Data Exchange (ETDEWEB)

Cheng, Xin; Chen, Jian-long; Ma, Zheng-lai; Zhang, Zhao-long; Lv, Shun; Mai, Dong-mei; Liu, Jia-jia [Department of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Medicine, Jinan University, Guangzhou 510632 (China); Chuai, Manli [Division of Cell and Developmental Biology, University of Dundee, Dundee DD1 5EH (United Kingdom); Lee, Kenneth Ka Ho; Wan, Chao [Stem Cell and Regeneration Thematic Research Programme, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Yang, Xuesong, E-mail: yang_xuesong@126.com [Department of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Medicine, Jinan University, Guangzhou 510632 (China); Institute of Fetal-Preterm Labor Medicine, Jinan University, Guangzhou 510632 (China)

2014-11-15

increased in mesenchymal cell mass treated by low concentration of Dex. Mmp-13 expression was obviously up-regulated by Dex in both mesenchymal cells and primary chondrocyte cultures. And Col10a1 expression was also increased by Dex exposure in chondrocyte. In summary, we have revealed that different concentrations of Dex exposure during early gestation could exert a biphasic effect on vertebrate skeletal development. - Highlights: • Chick embryos occurred shortening of the long bone following Dex exposure. • Dex suppressed chondrocytes proliferation and promoted apoptosis. • Dex exposure decreased ALP production and up-regulated Runx-2 and Mmp-13. • Dex exhibited biphasic effects on chondrogenic proliferation and nodule formation. • The hypertrophy and ossification were accelerated by Dex both in vivo and in vitro.

Comparative study on in vivo response of porous calcium carbonate composite ceramic and biphasic calcium phosphate ceramic

Energy Technology Data Exchange (ETDEWEB)

He, Fupo, E-mail: fphebm@126.com [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Ren, Weiwei [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Tian, Xiumei [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China); Liu, Wei; Wu, Shanghua [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Chen, Xiaoming, E-mail: xmchenw@126.com [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China)

2016-07-01

In a previous study, robust calcium carbonate composite ceramics (CC/PG) were prepared by using phosphate-based glass (PG) as an additive, which showed good cell response. In the present study the in vivo response of porous CC/PG was compared to that of porous biphasic calcium phosphate ceramics (BCP), using a rabbit femoral critical-size grafting model. The materials degradation and bone formation processes were evaluated by general observation, X-ray radiography, micro-computed tomography, and histological examination. The results demonstrated excellent biocompatibility and osteoconductivity, and progressive degradation of CC/PG and BCP. Although the in vitro degradation rate of CC/PG was distinctly faster than that of BCP, at 4 week post-implantation, the bone generation and material degradation of CC/PG were less than those of BCP. Nevertheless, at postoperative week 8, the increment of bone formation and material degradation of CC/PG was pronouncedly larger than that of BCP. These results show that CC/PG is a potential resorbable bone graft aside from the traditional synthetic ones. - Highlights: • A calcium carbonate composite ceramic (CC/PG) was acquired. • The in vivo response of CC/PG and biphasic calcium phosphate (BCP) was compared. • CC/PG showed faster in vitro degradation rate compared to BCP. • CC/PG showed less in vivo degradation and bone formation than BCP at week 4. • CC/PG had larger increment of degradation and bone formation than BCP at week 8.

Comparative study on in vivo response of porous calcium carbonate composite ceramic and biphasic calcium phosphate ceramic

International Nuclear Information System (INIS)

He, Fupo; Ren, Weiwei; Tian, Xiumei; Liu, Wei; Wu, Shanghua; Chen, Xiaoming

2016-01-01

In a previous study, robust calcium carbonate composite ceramics (CC/PG) were prepared by using phosphate-based glass (PG) as an additive, which showed good cell response. In the present study the in vivo response of porous CC/PG was compared to that of porous biphasic calcium phosphate ceramics (BCP), using a rabbit femoral critical-size grafting model. The materials degradation and bone formation processes were evaluated by general observation, X-ray radiography, micro-computed tomography, and histological examination. The results demonstrated excellent biocompatibility and osteoconductivity, and progressive degradation of CC/PG and BCP. Although the in vitro degradation rate of CC/PG was distinctly faster than that of BCP, at 4 week post-implantation, the bone generation and material degradation of CC/PG were less than those of BCP. Nevertheless, at postoperative week 8, the increment of bone formation and material degradation of CC/PG was pronouncedly larger than that of BCP. These results show that CC/PG is a potential resorbable bone graft aside from the traditional synthetic ones. - Highlights: • A calcium carbonate composite ceramic (CC/PG) was acquired. • The in vivo response of CC/PG and biphasic calcium phosphate (BCP) was compared. • CC/PG showed faster in vitro degradation rate compared to BCP. • CC/PG showed less in vivo degradation and bone formation than BCP at week 4. • CC/PG had larger increment of degradation and bone formation than BCP at week 8.

A new injectable biphasic hydrogel based on partially hydrolyzed polyacrylamide and nano hydroxyapatite, crosslinked with chromium acetate, as scaffold for cartilage regeneration

Science.gov (United States)

Koushki, N.; Tavassoli, H.; Katbab, A. A.; Katbab, P.; Bonakdar, S.

2015-05-01

Polymer scaffolds are applied in the field of tissue engineering as three dimensional structures to organize cells and present stimuli to direct generation of a desired damaged tissue. In situ gelling scaffolds have attracted great attentions, as they are structurally similar to the extra cellular matrix (ECM). In the present work, attempts have been made to design and fabricate a new injectable and crosslinkable biphasic hydrogel based on partially hydrolyzed polyacrylamide (HPAM), chromium acetate as crosslink agent and nanocrystalline hydroxyapatite (nHAp) as reinforcing and bioactive agent for repair and regeneration of damaged cartilage. The distinct characteristic of HPAM is the presence of carboxylate anion groups on its backbone which allows to engineer the structure of the hydrogel for the desired bioactivity with appropriate cells differentiation towards both soft and hard (bone) tissues. The synthesized hydrogel exhibited bifunctional behavior which was derived by its biphasic structure in which one phase was loaded with nano hydroxyapatite to provide integration capability by subchondral bones and fix the hydrogel at cartilage defect without a need for suturing. The other phase differentiates the rabbit adipogenic mesenchymal stem cells (MSCs) towards soft tissue. Rheomechanical spectrometry (RMS) was employed to study the kinetic of the gelation including induction time and rate, as well as to measure the ultimate elastic modulus of the optimum crosslinked hydrogel. Surface tension measurement was also performed to tailor the surface characteristics of the gels. In vitro culturing of the cells inside the crosslinked hydrogel revealed high viability and high differentiation of the encapsulated rabbit stem cells, providing that the chromium acetate level was kept below 0.2 wt%. Based on the obtained results, the designed and fabricated biphasic hydrogel exhibited high potential as carrier for the stem cells for cartilage tissue engineering application

46 CFR 185.602 - Hull markings.

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2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Hull markings. 185.602 Section 185.602 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Markings Required § 185.602 Hull markings. (a) Each vessel must be marked as required by part 67...

Replicating chromatin: a tale of histones

DEFF Research Database (Denmark)

Groth, Anja

2009-01-01

Chromatin serves structural and functional roles crucial for genome stability and correct gene expression. This organization must be reproduced on daughter strands during replication to maintain proper overlay of epigenetic fabric onto genetic sequence. Nucleosomes constitute the structural...... framework of chromatin and carry information to specify higher-order organization and gene expression. When replication forks traverse the chromosomes, nucleosomes are transiently disrupted, allowing the replication machinery to gain access to DNA. Histone recycling, together with new deposition, ensures...

Zika virus preferentially replicates in the female reproductive tract after vaginal inoculation of rhesus macaques.

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Timothy Carroll

2017-07-01

Full Text Available Zika virus (ZIKV is a mosquito-transmitted virus that can cause severe defects in an infected fetus. ZIKV is also transmitted by sexual contact, although the relative importance of sexual transmission is unclear. To better understand the role of sexual transmission in ZIKV pathogenesis, a nonhuman primate (NHP model of vaginal transmission was developed. ZIKV was readily transmitted to mature cycling female rhesus macaque (RM by vaginal inoculation with 104-106 plaque-forming units (PFU. However, there was variability in susceptibility between the individual RM with 1->8 vaginal inoculations required to establish infection. After treatment with Depoprovera, a widely used contraceptive progestin, two RM that initially resisted 8 vaginal ZIKV inoculations became infected after one ZIKV inoculation. Thus, Depoprovera seemed to enhance susceptibility to vaginal ZIKV transmission. Unexpectedly, the kinetics of virus replication and dissemination after intravaginal ZIKV inoculation were markedly different from RM infected with ZIKV by subcutaneous (SQ virus inoculation. Several groups have reported that after SQ ZIKV inoculation vRNA is rapidly detected in blood plasma with vRNA less common in urine and saliva and only rarely detected in female reproductive tract (FRT secretions. In contrast, in vaginally inoculated RM, plasma vRNA is delayed for several days and ZIKV replication in, and vRNA shedding from, the FRT was found in all 6 animals. Further, after intravaginal transmission ZIKV RNA shedding from FRT secretions was detected before or simultaneously with plasma vRNA, and persisted for at least as long. Thus, ZIKV replication in the FRT was independent of, and often preceded virus replication in the tissues contributing to plasma vRNA. These results support the conclusion that ZIKV preferentially replicates in the FRT after vaginal transmission, but not after SQ transmission, and raise the possibility that there is enhanced fetal infection and

Varicella-zoster virus (VZV) origin of DNA replication oriS influences origin-dependent DNA replication and flanking gene transcription.

Science.gov (United States)

Khalil, Mohamed I; Sommer, Marvin H; Hay, John; Ruyechan, William T; Arvin, Ann M

2015-07-01

The VZV genome has two origins of DNA replication (oriS), each of which consists of an AT-rich sequence and three origin binding protein (OBP) sites called Box A, C and B. In these experiments, the mutation in the core sequence CGC of the Box A and C not only inhibited DNA replication but also inhibited both ORF62 and ORF63 expression in reporter gene assays. In contrast the Box B mutation did not influence DNA replication or flanking gene transcription. These results suggest that efficient DNA replication enhances ORF62 and ORF63 transcription. Recombinant viruses carrying these mutations in both sites and one with a deletion of the whole oriS were constructed. Surprisingly, the recombinant virus lacking both copies of oriS retained the capacity to replicate in melanoma and HELF cells suggesting that VZV has another origin of DNA replication. Copyright © 2015 Elsevier Inc. All rights reserved.

Mark Kostabi soovib muuta inimesi õnnelikumaks / Kalev Mark Kostabi

Index Scriptorium Estoniae

Kostabi, Kalev Mark, 1960-

2008-01-01

Kalev Mark Kostabi oma sisekujunduslikest eelistustest, ameeriklaste ja itaallaste kodude sisekujunduse erinevustest, kunstist kui ruumikujunduse ühest osast, oma New Yorgi ja Rooma korterite kujundusest

Modes of DNA repair and replication

International Nuclear Information System (INIS)

Hanawalt, P.; Kondo, S.

1979-01-01

Modes of DNA repair and replication require close coordination as well as some overlap of enzyme functions. Some classes of recovery deficient mutants may have defects in replication rather than repair modes. Lesions such as the pyrimidine dimers produced by ultraviolet light irradiation are the blocks to normal DNA replication in vivo and in vitro. The DNA synthesis by the DNA polymerase 1 of E. coli is blocked at one nucleotide away from the dimerized pyrimidines in template strands. Thus, some DNA polymerases seem to be unable to incorporate nucleotides opposite to the non-pairing lesions in template DNA strands. The lesions in template DNA strands may block the sequential addition of nucleotides in the synthesis of daughter strands. Normal replication utilizes a constitutive ''error-free'' mode that copies DNA templates with high fidelity, but which may be totally blocked at a lesion that obscures the appropriate base pairing specificity. It might be expected that modified replication system exhibits generally high error frequency. The error rate of DNA polymerases may be controlled by the degree of phosphorylation of the enzyme. Inducible SOS system is controlled by recA genes that also control the pathways for recombination. It is possible that SOS system involves some process other than the modification of a blocked replication apparatus to permit error-prone transdimer synthesis. (Yamashita, S.)

Charter School Replication. Policy Guide

Science.gov (United States)

Rhim, Lauren Morando

2009-01-01

"Replication" is the practice of a single charter school board or management organization opening several more schools that are each based on the same school model. The most rapid strategy to increase the number of new high-quality charter schools available to children is to encourage the replication of existing quality schools. This policy guide…

Replication of kinetoplast minicircle DNA

International Nuclear Information System (INIS)

Sheline, C.T.

1989-01-01

These studies describe the isolation and characterization of early minicircle replication intermediates from Crithidia fasciculata, and Leishmania tarentolae, the mitochondrial localization of a type II topoisomerase (TIImt) in C. fasciculata, and the implication of the aforementioned TIImt in minicircle replication in L. tarentolae. Early minicircle replication intermediates from C. fasciculata were identified and characterized using isolated kinetoplasts to incorporate radiolabeled nucleotides into its DNA. The pulse-label in an apparent theta-type intermediate chase into two daughter molecules. A uniquely gapped, ribonucleotide primed, knotted molecule represents the leading strand in the model proposed, and a highly gapped molecule represents the lagging strand. This theta intermediate is repaired in vitro to a doubly nicked catenated dimer which was shown to result from the replication of a single parental molecule. Very similar intermediates were found in the heterogeneous population of minicircles of L. tarentolae. The sites of the Leishmania specific discontinuities were mapped and shown to lie within the universally conserved sequence blocks in identical positions as compared to C. fasciculata and Trypanosoma equiperdum

Manual of Cupule Replication Technology

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Giriraj Kumar

2015-09-01

Full Text Available Throughout the world, iconic rock art is preceded by non-iconic rock art. Cupules (manmade, roughly semi-hemispherical depressions on rocks form the major bulk of the early non-iconic rock art globally. The antiquity of cupules extends back to the Lower Paleolithic in Asia and Africa, hundreds of thousand years ago. When one observes these cupules, the inquisitive mind poses so many questions with regard to understanding their technology, reasons for selecting the site, which rocks were used to make the hammer stones used, the skill and cognitive abilities employed to create the different types of cupules, the objective of their creation, their age, and so on. Replication of the cupules can provide satisfactory answers to some of these questions. Comparison of the hammer stones and cupules produced by the replication process with those obtained from excavation can provide support to observations. This paper presents a manual of cupule replication technology based on our experience of cupule replication on hard quartzite rock near Daraki-Chattan in the Chambal Basin, India.

Targeting DNA Replication Stress for Cancer Therapy

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Jun Zhang

2016-08-01

Full Text Available The human cellular genome is under constant stress from extrinsic and intrinsic factors, which can lead to DNA damage and defective replication. In normal cells, DNA damage response (DDR mediated by various checkpoints will either activate the DNA repair system or induce cellular apoptosis/senescence, therefore maintaining overall genomic integrity. Cancer cells, however, due to constitutive growth signaling and defective DDR, may exhibit “replication stress” —a phenomenon unique to cancer cells that is described as the perturbation of error-free DNA replication and slow-down of DNA synthesis. Although replication stress has been proven to induce genomic instability and tumorigenesis, recent studies have counterintuitively shown that enhancing replicative stress through further loosening of the remaining checkpoints in cancer cells to induce their catastrophic failure of proliferation may provide an alternative therapeutic approach. In this review, we discuss the rationale to enhance replicative stress in cancer cells, past approaches using traditional radiation and chemotherapy, and emerging approaches targeting the signaling cascades induced by DNA damage. We also summarize current clinical trials exploring these strategies and propose future research directions including the use of combination therapies, and the identification of potential new targets and biomarkers to track and predict treatment responses to targeting DNA replication stress.

Global profiling of DNA replication timing and efficiency reveals that efficient replication/firing occurs late during S-phase in S. pombe.

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Majid Eshaghi

Full Text Available BACKGROUND: During S. pombe S-phase, initiation of DNA replication occurs at multiple sites (origins that are enriched with AT-rich sequences, at various times. Current studies of genome-wide DNA replication profiles have focused on the DNA replication timing and origin location. However, the replication and/or firing efficiency of the individual origins on the genomic scale remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: Using the genome-wide ORF-specific DNA microarray analysis, we show that in S. pombe, individual origins fire with varying efficiencies and at different times during S-phase. The increase in DNA copy number plotted as a function of time is approximated to the near-sigmoidal model, when considering the replication start and end timings at individual loci in cells released from HU-arrest. Replication efficiencies differ from origin to origin, depending on the origin's firing efficiency. We have found that DNA replication is inefficient early in S-phase, due to inefficient firing at origins. Efficient replication occurs later, attributed to efficient but late-firing origins. Furthermore, profiles of replication timing in cds1Delta cells are abnormal, due to the failure in resuming replication at the collapsed forks. The majority of the inefficient origins, but not the efficient ones, are found to fire in cds1Delta cells after HU removal, owing to the firing at the remaining unused (inefficient origins during HU treatment. CONCLUSIONS/SIGNIFICANCE: Taken together, our results indicate that efficient DNA replication/firing occurs late in S-phase progression in cells after HU removal, due to efficient late-firing origins. Additionally, checkpoint kinase Cds1p is required for maintaining the efficient replication/firing late in S-phase. We further propose that efficient late-firing origins are essential for ensuring completion of DNA duplication by the end of S-phase.

27 CFR 28.193 - Export marks.

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2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.193... Drawback Filing of Notice and Removal § 28.193 Export marks. In addition to the marks and brands required... chapter, the exporter shall mark the word “Export” on the Government side of each case or Government head...

27 CFR 28.103 - Export marks.

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2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.103... Manufacturing Bonded Warehouse § 28.103 Export marks. (a) General. In addition to the marks and brands required... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side of...

27 CFR 28.144 - Export marks.

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2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.144... § 28.144 Export marks. (a) General Requirement. In addition to the marks and brands required to be... brewer shall mark the word “Export” on each container or case of beer, or the words “Beer concentrate for...

27 CFR 28.154 - Export marks.

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2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.154..., for Exportation or Transfer to a Foreign-Trade Zone § 28.154 Export marks. In addition to the marks... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side of...

Replicated Data Management for Mobile Computing

CERN Document Server

Douglas, Terry

2008-01-01

Managing data in a mobile computing environment invariably involves caching or replication. In many cases, a mobile device has access only to data that is stored locally, and much of that data arrives via replication from other devices, PCs, and services. Given portable devices with limited resources, weak or intermittent connectivity, and security vulnerabilities, data replication serves to increase availability, reduce communication costs, foster sharing, and enhance survivability of critical information. Mobile systems have employed a variety of distributed architectures from client-server

pUL34 binding near the human cytomegalovirus origin of lytic replication enhances DNA replication and viral growth.

Science.gov (United States)

Slayton, Mark; Hossain, Tanvir; Biegalke, Bonita J

2018-05-01

The human cytomegalovirus (HCMV) UL34 gene encodes sequence-specific DNA-binding proteins (pUL34) which are required for viral replication. Interactions of pUL34 with DNA binding sites represses transcription of two viral immune evasion genes, US3 and US9. 12 additional predicted pUL34-binding sites are present in the HCMV genome (strain AD169) with three binding sites concentrated near the HCMV origin of lytic replication (oriLyt). We used ChIP-seq analysis of pUL34-DNA interactions to confirm that pUL34 binds to the oriLyt region during infection. Mutagenesis of the UL34-binding sites in an oriLyt-containing plasmid significantly reduced viral-mediated oriLyt-dependent DNA replication. Mutagenesis of these sites in the HCMV genome reduced the replication efficiencies of the resulting viruses. Protein-protein interaction analyses demonstrated that pUL34 interacts with the viral proteins IE2, UL44, and UL84, that are essential for viral DNA replication, suggesting that pUL34-DNA interactions in the oriLyt region are involved in the DNA replication cascade. Copyright © 2018 Elsevier Inc. All rights reserved.

Replication of urban innovations - prioritization of strategies for the replication of Dhaka's community-based decentralized composting model.

Science.gov (United States)

Yedla, Sudhakar

2012-01-01

Dhaka's community-based decentralized composting (DCDC) is a successful demonstration of solid waste management by adopting low-cost technology, local resources community participation and partnerships among the various actors involved. This paper attempts to understand the model, necessary conditions, strategies and their priorities to replicate DCDC in the other developing cities of Asia. Thirteen strategies required for its replication are identified and assessed based on various criteria, namely transferability, longevity, economic viability, adaptation and also overall replication. Priority setting by multi-criteria analysis by applying analytic hierarchy process revealed that immediate transferability without long-term and economic viability consideration is not advisable as this would result in unsustainable replication of DCDC. Based on the analysis, measures to ensure the product quality control; partnership among stakeholders (public-private-community); strategies to achieve better involvement of the private sector in solid waste management (entrepreneurship in approach); simple and low-cost technology; and strategies to provide an effective interface among the complementing sectors are identified as important strategies for its replication.

1L Mark-IV Target Design Review

Energy Technology Data Exchange (ETDEWEB)

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

2017-11-16

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

Replication of bacteriophage lambda DNA

International Nuclear Information System (INIS)

Tsurimoto, T.; Matsubara, K.

1983-01-01

In this paper results of studies on the mechanism of bacteriophage lambda replication using molecular biological and biochemical approaches are reported. The purification of the initiator proteins, O and P, and the role of the O and P proteins in the initiation of lambda DNA replication through interactions with specific DNA sequences are described. 47 references, 15 figures

Direct Visualization of DNA Replication Dynamics in Zebrafish Cells.

Science.gov (United States)

Kuriya, Kenji; Higashiyama, Eriko; Avşar-Ban, Eriko; Tamaru, Yutaka; Ogata, Shin; Takebayashi, Shin-ichiro; Ogata, Masato; Okumura, Katsuzumi

2015-12-01

Spatiotemporal regulation of DNA replication in the S-phase nucleus has been extensively studied in mammalian cells because it is tightly coupled with the regulation of other nuclear processes such as transcription. However, little is known about the replication dynamics in nonmammalian cells. Here, we analyzed the DNA replication processes of zebrafish (Danio rerio) cells through the direct visualization of replicating DNA in the nucleus and on DNA fiber molecules isolated from the nucleus. We found that zebrafish chromosomal DNA at the nuclear interior was replicated first, followed by replication of DNA at the nuclear periphery, which is reminiscent of the spatiotemporal regulation of mammalian DNA replication. However, the relative duration of interior DNA replication in zebrafish cells was longer compared to mammalian cells, possibly reflecting zebrafish-specific genomic organization. The rate of replication fork progression and ori-to-ori distance measured by the DNA combing technique were ∼ 1.4 kb/min and 100 kb, respectively, which are comparable to those in mammalian cells. To our knowledge, this is a first report that measures replication dynamics in zebrafish cells.

Insulated hsp70B' promoter: stringent heat-inducible activity in replication-deficient, but not replication-competent adenoviruses.

Science.gov (United States)

Rohmer, Stanimira; Mainka, Astrid; Knippertz, Ilka; Hesse, Andrea; Nettelbeck, Dirk M

2008-04-01

Key to the realization of gene therapy is the development of efficient and targeted gene transfer vectors. Therapeutic gene transfer by replication-deficient or more recently by conditionally replication-competent/oncolytic adenoviruses has shown much promise. For specific applications, however, it will be advantageous to provide vectors that allow for external control of gene expression. The efficient cellular heat shock system in combination with available technology for focused and controlled hyperthermia suggests heat-regulated transcription control as a promising tool for this purpose. We investigated the feasibility of a short fragment of the human hsp70B' promoter, with and without upstream insulator elements, for the regulation of transgene expression by replication-deficient or oncolytic adenoviruses. Two novel adenoviral vectors with an insulated hsp70B' promoter were developed and showed stringent heat-inducible gene expression with induction ratios up to 8000-fold. In contrast, regulation of gene expression from the hsp70B' promoter without insulation was suboptimal. In replication-competent/oncolytic adenoviruses regulation of the hsp70B' promoter was lost specifically during late replication in permissive cells and could not be restored by the insulators. We developed novel adenovirus gene transfer vectors that feature improved and stringent regulation of transgene expression from the hsp70B' promoter using promoter insulation. These vectors have potential for gene therapy applications that benefit from external modulation of therapeutic gene expression or for combination therapy with hyperthermia. Furthermore, our study reveals that vector replication can deregulate inserted cellular promoters, an observation which is of relevance for the development of replication-competent/oncolytic gene transfer vectors. (c) 2008 John Wiley & Sons, Ltd.

Replication assessment of surface texture at sub-micrometre scale

DEFF Research Database (Denmark)

Quagliotti, Danilo; Tosello, Guido; Hansen, Hans Nørgaard

2017-01-01

[2]. A replication process requires reproducing a master geometry by conveying it to a substrate material. It is typically induced by means of different energy sources (usually heat and force) and a direct physical contact between the master and the substrate. Furthermore, concepts of advanced......, because of the replication nature of molding processes, the required specifications for the manufacture of micro molded components must be ensured by means of a metrological approach to surface replication and dimensional control of both master geometry and replicated substrate [3]-[4]. Therefore...... replication was assessed by the replication fidelity, i.e., comparing the produced parts with the tool used to replicate the geometry. Furthermore, the uncertainty of the replication fidelity was achieved by propagating the uncertainties evaluated for both masters and replicas. Finally, despite the specimens...

Mechanisms and regulation of DNA replication initiation in eukaryotes.

Science.gov (United States)

Parker, Matthew W; Botchan, Michael R; Berger, James M

2017-04-01

Cellular DNA replication is initiated through the action of multiprotein complexes that recognize replication start sites in the chromosome (termed origins) and facilitate duplex DNA melting within these regions. In a typical cell cycle, initiation occurs only once per origin and each round of replication is tightly coupled to cell division. To avoid aberrant origin firing and re-replication, eukaryotes tightly regulate two events in the initiation process: loading of the replicative helicase, MCM2-7, onto chromatin by the origin recognition complex (ORC), and subsequent activation of the helicase by its incorporation into a complex known as the CMG. Recent work has begun to reveal the details of an orchestrated and sequential exchange of initiation factors on DNA that give rise to a replication-competent complex, the replisome. Here, we review the molecular mechanisms that underpin eukaryotic DNA replication initiation - from selecting replication start sites to replicative helicase loading and activation - and describe how these events are often distinctly regulated across different eukaryotic model organisms.

High contrast laser marking of alumina

International Nuclear Information System (INIS)

Penide, J.; Quintero, F.; Riveiro, A.; Fernández, A.; Val, J. del; Comesaña, R.; Lusquiños, F.; Pou, J.

2015-01-01

Highlights: • Laser marking of alumina using near infrared (NIR) lasers was experimentally analyzed. • Color change produced by NIR lasers is due to thermally induced oxygen vacancies. • Laser marking results obtained using NIR lasers and green laser are compared. • High contrast marks on alumina were achieved. - Abstract: Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks

Square biphasic pulse deep brain stimulation for essential tremor: The BiP tremor study.

Science.gov (United States)

De Jesus, Sol; Almeida, Leonardo; Shahgholi, Leili; Martinez-Ramirez, Daniel; Roper, Jaimie; Hass, Chris J; Akbar, Umer; Wagle Shukla, Aparna; Raike, Robert S; Okun, Michael S

2018-01-01

Conventional deep brain stimulation (DBS) utilizes regular, high frequency pulses to treat medication-refractory symptoms in essential tremor (ET). Modifications of DBS pulse shape to achieve improved effectiveness is a promising approach. The current study assessed the safety, tolerability and effectiveness of square biphasic pulse shaping as an alternative to conventional ET DBS. This pilot study compared biphasic pulses (BiP) versus conventional DBS pulses (ClinDBS). Eleven ET subjects with clinically optimized ventralis intermedius nucleus DBS were enrolled. Objective measures were obtained over 3 h while ON BiP stimulation. There was observed benefit in the Fahn-Tolosa Tremor Rating Scale (TRS) for BiP conditions when compared to the DBS off condition and to ClinDBS setting. Total TRS scores during the DBS OFF condition (28.5 IQR = 24.5-35.25) were significantly higher than the other time points. Following active DBS, TRS improved to (20 IQR = 13.8-24.3) at ClinDBS setting and to (16.5 IQR = 12-20.75) at the 3 h period ON BiP stimulation (p = 0.001). Accelerometer recordings revealed improvement in tremor at rest (χ 2  = 16.1, p = 0.006), posture (χ 2  = 15.9, p = 0.007) and with action (χ 2  = 32.1, p=<0.001) when comparing median total scores at ClinDBS and OFF DBS conditions to 3 h ON BiP stimulation. There were no adverse effects and gait was not impacted. BiP was safe, tolerable and effective on the tremor symptoms when tested up to 3 h. This study demonstrated the feasibility of applying a novel DBS waveform in the clinic setting. Larger prospective studies with longer clinical follow-up will be required. Copyright © 2017. Published by Elsevier Ltd.

Assessing composition and structure of soft biphasic media from Kelvin-Voigt fractional derivative model parameters

Science.gov (United States)

Zhang, Hongmei; Wang, Yue; Fatemi, Mostafa; Insana, Michael F.

2017-03-01

Kelvin-Voigt fractional derivative (KVFD) model parameters have been used to describe viscoelastic properties of soft tissues. However, translating model parameters into a concise set of intrinsic mechanical properties related to tissue composition and structure remains challenging. This paper begins by exploring these relationships using a biphasic emulsion materials with known composition. Mechanical properties are measured by analyzing data from two indentation techniques—ramp-stress relaxation and load-unload hysteresis tests. Material composition is predictably correlated with viscoelastic model parameters. Model parameters estimated from the tests reveal that elastic modulus E 0 closely approximates the shear modulus for pure gelatin. Fractional-order parameter α and time constant τ vary monotonically with the volume fraction of the material’s fluid component. α characterizes medium fluidity and the rate of energy dissipation, and τ is a viscous time constant. Numerical simulations suggest that the viscous coefficient η is proportional to the energy lost during quasi-static force-displacement cycles, E A . The slope of E A versus η is determined by α and the applied indentation ramp time T r. Experimental measurements from phantom and ex vivo liver data show close agreement with theoretical predictions of the η -{{E}A} relation. The relative error is less than 20% for emulsions 22% for liver. We find that KVFD model parameters form a concise features space for biphasic medium characterization that described time-varying mechanical properties. The experimental work was carried out at the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Methodological development, including numerical simulation and all data analysis, were carried out at the school of Life Science and Technology, Xi’an JiaoTong University, 710049, China.

Commercial Building Partnerships Replication and Diffusion

Energy Technology Data Exchange (ETDEWEB)

Antonopoulos, Chrissi A.; Dillon, Heather E.; Baechler, Michael C.

2013-09-16

This study presents findings from survey and interview data investigating replication efforts of Commercial Building Partnership (CBP) partners that worked directly with the Pacific Northwest National Laboratory (PNNL). PNNL partnered directly with 12 organizations on new and retrofit construction projects, which represented approximately 28 percent of the entire U.S. Department of Energy (DOE) CBP program. Through a feedback survey mechanism, along with personal interviews, PNNL gathered quantitative and qualitative data relating to replication efforts by each organization. These data were analyzed to provide insight into two primary research areas: 1) CBP partners’ replication efforts of technologies and approaches used in the CBP project to the rest of the organization’s building portfolio (including replication verification), and, 2) the market potential for technology diffusion into the total U.S. commercial building stock, as a direct result of the CBP program. The first area of this research focused specifically on replication efforts underway or planned by each CBP program participant. Factors that impact replication include motivation, organizational structure and objectives firms have for implementation of energy efficient technologies. Comparing these factors between different CBP partners revealed patterns in motivation for constructing energy efficient buildings, along with better insight into market trends for green building practices. The second area of this research develops a diffusion of innovations model to analyze potential broad market impacts of the CBP program on the commercial building industry in the United States.

Changing Context of Trade Mark Protection in India: A Review of the Trade Marks Act, 1999

OpenAIRE

Pathak, Akhileshwar

2004-01-01

With liberalisation and globalisation of the Indian economy, it has become possible for anyone to get into production and services in most of the sectors. This has led to rampant misuse and appropriation of trade marks. In an insulated economy, with monopoly markets, law protecting trade marks had a limited role. In the changed context, however, trade mark law will be a field of much interest for academics and practitioners. Towards this, the paper explores the formation of trade mark law in ...

Extremal dynamics in random replicator ecosystems

Energy Technology Data Exchange (ETDEWEB)

Kärenlampi, Petri P., E-mail: petri.karenlampi@uef.fi

2015-10-02

The seminal numerical experiment by Bak and Sneppen (BS) is repeated, along with computations with replicator models, including a greater amount of features. Both types of models do self-organize, and do obey power-law scaling for the size distribution of activity cycles. However species extinction within the replicator models interferes with the BS self-organized critical (SOC) activity. Speciation–extinction dynamics ruins any stationary state which might contain a steady size distribution of activity cycles. The BS-type activity appears as a dissimilar phenomenon in comparison to speciation–extinction dynamics in the replicator system. No criticality is found from the speciation–extinction dynamics. Neither are speciations and extinctions in real biological macroevolution known to contain any diverging distributions, or self-organization towards any critical state. Consequently, biological macroevolution probably is not a self-organized critical phenomenon. - Highlights: • Extremal Dynamics organizes random replicator ecosystems to two phases in fitness space. • Replicator systems show power-law scaling of activity. • Species extinction interferes with Bak–Sneppen type mutation activity. • Speciation–extinction dynamics does not show any critical phase transition. • Biological macroevolution probably is not a self-organized critical phenomenon.

Experimental applications for the MARK-1 and MARK-1A pulsed ionizing radiation detection systems. Volume 3

International Nuclear Information System (INIS)

Harker, Y.D.; Lawrence, R.S.; Yoon, W.Y.; Lones, J.L.

1993-12-01

This report is the third volume in a three volume set describing the MARK series of pulsed ionizing radiation detection systems. This volume describes the MARK-1A detection system, compares it with the MARK-1 system, and describes the experimental testing of the detection systems. Volume 1 of this set presents the technical specifications for the MARK-1 detection system. Volume 2 is an operations manual specifically for the MARK-1 system, but it generally applies to the MARK-1A system as well. These detection systems operate remotely and detect photon radiation from a single or a multiple pulsed source. They contain multiple detector (eight in the MARK-1 and ten in the MARK-1A) for determination of does and incident photon effective energy. The multiple detector arrangement, having different detector sizes and shield thicknesses, provides the capability of determining the effective photon energy of the radiation spectrum. Dose measurements using these units are consistent with TLD measurements. The detection range is from 3 nanorads to 90 microrads per source burst; the response is linear over that range. Three units were built and are ready for field deployment

The Genomic Replication of the Crenarchaeal Virus SIRV2

DEFF Research Database (Denmark)

Martinez Alvarez, Laura

reinitiation events may partially explain the branched topology of the viral replication intermediates. We also analyzed the intracellular location of viral replication, showing the formation of viral peripheral replication centers in SIRV2-infected cells, where viral DNA synthesis and replication...

Specific interaction of the nonstructural protein NS1 of minute virus of mice (MVM) with [ACCA](2) motifs in the centre of the right-end MVM DNA palindrome induces hairpin-primed viral DNA replication.

Science.gov (United States)

Willwand, Kurt; Moroianu, Adela; Hörlein, Rita; Stremmel, Wolfgang; Rommelaere, Jean

2002-07-01

The linear single-stranded DNA genome of minute virus of mice (MVM) is replicated via a double-stranded replicative form (RF) intermediate DNA. Amplification of viral RF DNA requires the structural transition of the right-end palindrome from a linear duplex into a double-hairpin structure, which serves for the repriming of unidirectional DNA synthesis. This conformational transition was found previously to be induced by the MVM nonstructural protein NS1. Elimination of the cognate NS1-binding sites, [ACCA](2), from the central region of the right-end palindrome next to the axis of symmetry was shown to markedly reduce the efficiency of hairpin-primed DNA replication, as measured in a reconstituted in vitro replication system. Thus, [ACCA](2) sequence motifs are essential as NS1-binding elements in the context of the structural transition of the right-end MVM palindrome.

Biphasic Effect of Curcumin on Morphine Tolerance: A Preliminary Evidence from Cytokine/Chemokine Protein Array Analysis

Directory of Open Access Journals (Sweden)

Jui-An Lin

2011-01-01

Full Text Available The aim of this study was to evaluate the effect of curcumin on morphine tolerance and the corresponding cytokine/chemokine changes. Male ICR mice were made tolerant to morphine by daily subcutaneous injection for 7 days. Intraperitoneal injections of vehicle, low-dose or high-dose curcumin were administered 15 min after morphine injection, either acutely or chronically for 7 days to test the effect of curcumin on morphine-induced antinociception and development of morphine tolerance. On day 8, cumulative dose-response curves were generated and the 50% of maximal analgesic dose values were calculated and compared among groups. Corresponding set of mice were used for analyzing the cytokine responses by antibody-based cytokine protein array. Acute, high-dose curcumin enhanced morphine-induced antinociception. While morphine tolerance was attenuated by administration of low-dose curcumin following morphine injections for 7 days, it was aggravated by chronic high-dose curcumin following morphine injection, suggesting a biphasic effect of curcumin on morphine-induced tolerance. Of the 96 cytokine/chemokines analyzed by mouse cytokine protein array, 14 cytokines exhibited significant changes after the different 7-day treatments. Mechanisms for the modulatory effects of low-dose and high-dose curcumin on morphine tolerance were discussed. Even though curcumin itself is a neuroprotectant and low doses of the compound serve to attenuate morphine tolerance, high-doses of curcumin might cause neurotoxicity and aggravate morphine tolerance by inhibiting the expression of antiapoptotic cytokines and neuroprotective factors. Our results indicate that the effect of curcumin on morphine tolerance may be biphasic, and therefore curcumin should be used cautiously.

The Role of the Transcriptional Response to DNA Replication Stress.

Science.gov (United States)

Herlihy, Anna E; de Bruin, Robertus A M

2017-03-02

During DNA replication many factors can result in DNA replication stress. The DNA replication stress checkpoint prevents the accumulation of replication stress-induced DNA damage and the potential ensuing genome instability. A critical role for post-translational modifications, such as phosphorylation, in the replication stress checkpoint response has been well established. However, recent work has revealed an important role for transcription in the cellular response to DNA replication stress. In this review, we will provide an overview of current knowledge of the cellular response to DNA replication stress with a specific focus on the DNA replication stress checkpoint transcriptional response and its role in the prevention of replication stress-induced DNA damage.

The Role of the Transcriptional Response to DNA Replication Stress

Science.gov (United States)

Herlihy, Anna E.; de Bruin, Robertus A.M.

2017-01-01

During DNA replication many factors can result in DNA replication stress. The DNA replication stress checkpoint prevents the accumulation of replication stress-induced DNA damage and the potential ensuing genome instability. A critical role for post-translational modifications, such as phosphorylation, in the replication stress checkpoint response has been well established. However, recent work has revealed an important role for transcription in the cellular response to DNA replication stress. In this review, we will provide an overview of current knowledge of the cellular response to DNA replication stress with a specific focus on the DNA replication stress checkpoint transcriptional response and its role in the prevention of replication stress-induced DNA damage. PMID:28257104

Augmented marked graphs

CERN Document Server

Cheung, King Sing

2014-01-01

Petri nets are a formal and theoretically rich model for the modelling and analysis of systems. A subclass of Petri nets, augmented marked graphs possess a structure that is especially desirable for the modelling and analysis of systems with concurrent processes and shared resources.This monograph consists of three parts: Part I provides the conceptual background for readers who have no prior knowledge on Petri nets; Part II elaborates the theory of augmented marked graphs; finally, Part III discusses the application to system integration. The book is suitable as a first self-contained volume

Court presentation of bite mark evidence.

Science.gov (United States)

Drinnan, A J; Melton, M J

1985-12-01

The uniqueness of an individual's bite mark is generally accepted. The use of bite mark analysis to identify or exclude those suspected of crimes is now a well established activity in forensic dentistry. Although the techniques for evaluating bite mark evidence are extremely sophisticated, it is important that the courtroom presentation of such evidence should be as simple as possible and be directed towards those who must judge it. Dentists likely to be involved in the courtroom presentation of bite mark evidence should: be certain that their local law enforcement personnel are frequently updated on the techniques to be used for producing the optimum evidence needed to evaluate bite marks; become acquainted with the current techniques of evaluating bite mark evidence and understand their difficulties and pitfalls; meet with the lawyers (prosecution or defence) before a courtroom appearance, briefing them on the significance of the particular findings; prepare clear and easily understandable visual aids to present to the court the techniques used in the analysis and the bases for the conclusion reached; and offer conclusions derived from the bite mark investigation.

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

Directory of Open Access Journals (Sweden)

Josef Schachtner

2016-08-01

Full Text Available A home-built microreactor system for light-mediated biphasic gas/liquid reactions was assembled from simple commercial components. This paper describes in full detail the nature and function of the required building elements, the assembly of parts, and the tuning and interdependencies of the most important reactor and reaction parameters. Unlike many commercial thin-film and microchannel reactors, the described set-up operates residence times of up to 30 min which cover the typical rates of many organic reactions. The tubular microreactor was successfully applied to the photooxygenation of hydrocarbons (Schenck ene reaction. Major emphasis was laid on the realization of a constant and highly reproducible gas/liquid slug flow and the effective illumination by an appropriate light source. The optimized set of conditions enabled the shortening of reaction times by more than 99% with equal chemoselectivities. The modular home-made flow reactor can serve as a prototype model for the continuous operation of various other reactions at light/liquid/gas interfaces in student, research, and industrial laboratories.

DNA Copy-Number Control through Inhibition of Replication Fork Progression

Directory of Open Access Journals (Sweden)

Jared T. Nordman

2014-11-01

Full Text Available Proper control of DNA replication is essential to ensure faithful transmission of genetic material and prevent chromosomal aberrations that can drive cancer progression and developmental disorders. DNA replication is regulated primarily at the level of initiation and is under strict cell-cycle regulation. Importantly, DNA replication is highly influenced by developmental cues. In Drosophila, specific regions of the genome are repressed for DNA replication during differentiation by the SNF2 domain-containing protein SUUR through an unknown mechanism. We demonstrate that SUUR is recruited to active replication forks and mediates the repression of DNA replication by directly inhibiting replication fork progression instead of functioning as a replication fork barrier. Mass spectrometry identification of SUUR-associated proteins identified the replicative helicase member CDC45 as a SUUR-associated protein, supporting a role for SUUR directly at replication forks. Our results reveal that control of eukaryotic DNA copy number can occur through the inhibition of replication fork progression.

Biphasic Fluence-Response Curves for Phytochrome-Mediated Kalanchoë Seed Germination 1

Science.gov (United States)

Rethy, Roger; Dedonder, Andrée; De Petter, Edwin; Van Wiemeersch, Luc; Fredericq, Henri; De Greef, Jan; Steyaert, Herman; Stevens, Hilde

1987-01-01

The fluence-response curves for the effect of two red pulses separated by 24 hours on the germination of Kalanchoe blossfeldiana Poelln. cv Vesuv seeds, incubated on gibberellic acid (GA3) are biphasic for suboptimal concentrations. The response in the low fluence range corresponds with a classical red/far-red reversible phytochrome mediated reaction. GA3 induces an additional response in the very low fluence range, which is also phytochrome mediated. The sensitivity to phytochrome-far-red absorbing form (Pfr), however, is increased about 20,000-fold, so that even far-red fluences become saturating. Both in the very low and low fluence response range, the maximal responses induced by saturating fluences are modulated by the GA3 concentration. GA3 having no direct influence on the phytochrome phototransformations, alters the Pfr requirement and determines the responding seed population fraction in the very low and low fluence range. The effet of GA3 appears to be on the transduction chain of the phytochrome signal. PMID:16665187

TSDC and impedance spectroscopy measurements on hydroxyapatite, β-tricalcium phosphate and hydroxyapatite/β-tricalcium phosphate biphasic bioceramics

Science.gov (United States)

Prezas, P. R.; Melo, B. M. G.; Costa, L. C.; Valente, M. A.; Lança, M. C.; Ventura, J. M. G.; Pinto, L. F. V.; Graça, M. P. F.

2017-12-01

Bone grafting and surgical interventions related with orthopaedic disorders consist in a big business, generating large revenues worldwide every year. There is a need to replace the biomaterials that currently still dominate this market, i.e., autografts and allografts, due to their disadvantages, such as limited availability, need for additional surgeries and diseases transmission possibilities. The most promising replacement materials are biomaterials with bioactive properties, such as the calcium phosphate-based bioceramics group. The bioactivity of these materials, i.e., the rate at which they promote the growth and directly bond with the new host biological bone, can be enhanced through their electrical polarization. In the present work, the electrical polarization features of pure hydroxyapatite (Hap), pure β-tricalcium phosphate (β-TCP) and biphasic hydroxyapatite/β-tricalcium phosphate composites (HTCP) were analyzed by measuring thermally stimulated depolarization currents (TSDC). The samples were thermoelectrically polarized at 500 °C under a DC electric field with a magnitude of 5 kV/cm. The biphasic samples were also polarized under electric fields with different magnitudes: 2, 3, 4 and 5 kV/cm. Additionally, the depolarization processes detected in the TSDC measurements were correlated with dielectric relaxation processes observed in impedance spectroscopy (IS) measurements. The results indicate that the β-TCP crystalline phase has a considerable higher ability to store electrical charge compared with the Hap phase. This indicates that it has a suitable composition and structure for ionic conduction and establishment of a large electric charge density, providing great potential for orthopaedic applications.

Nuclear particle track-etched anti-bogus mark

International Nuclear Information System (INIS)

He Xiangming; Yan Yushun; Zhang Quanrong

2003-01-01

Nuclear particle track-etched anti-bogus mark is a new type of forgery-proof product after engraving gravure printing, thermocolour, fluorescence, laser hologram and metal concealed anti-bogus mark. The mark is manufactured by intricate high technology and the state strictly controlled sensitive nuclear facilities to ensure the mark not to be copied. The pattern of the mark is specially characterized by permeability of liquid to be discriminated from forgery. The genuine mark can be distinguished from sham one by transparent liquid (e.g. water), colorful pen and chemical reagent. The mark has passed the official examination of health safety. It is no danger of nuclear irradiation. (author)

High efficiency metal marking with CO2 laser and glass marking with excimer laser

DEFF Research Database (Denmark)

Bastue, Jens; Olsen, Flemmming Ove

1997-01-01

with a thoroughly tested ray-tracing model is presented and compared with experimental results. Special emphasis is put on two different applications namely marking in metal with TEA-CO2 laser and marking in glass with excimer laser. The results are evaluated on the basis of the achievable energy enhancement......Today, mask based laser materials processing and especially marking is widely used. However, the energy efficiency in such processes is very low [1].This paper gives a review of the results, that may be obtained using the energy enhancing technique [1]. Results of simulations performed...

Initiation of Replication in Escherichia coli

DEFF Research Database (Denmark)

Frimodt-Møller, Jakob

The circular chromosome of Escherichia coli is replicated by two replisomes assembled at the unique origin and moving in the opposite direction until they meet in the less well defined terminus. The key protein in initiation of replication, DnaA, facilitates the unwinding of double-stranded DNA...... to single-stranded DNA in oriC. Although DnaA is able to bind both ADP and ATP, DnaA is only active in initiation when bound to ATP. Although initiation of replication, and the regulation of this, is thoroughly investigated it is still not fully understood. The overall aim of the thesis was to investigate...... the regulation of initiation, the effect on the cell when regulation fails, and if regulation was interlinked to chromosomal organization. This thesis uncovers that there exists a subtle balance between chromosome replication and reactive oxygen species (ROS) inflicted DNA damage. Thus, failure in regulation...

LHCb Data Replication During SC3

CERN Multimedia

Smith, A

2006-01-01

LHCb's participation in LCG's Service Challenge 3 involves testing the bulk data transfer infrastructure developed to allow high bandwidth distribution of data across the grid in accordance with the computing model. To enable reliable bulk replication of data, LHCb's DIRAC system has been integrated with gLite's File Transfer Service middleware component to make use of dedicated network links between LHCb computing centres. DIRAC's Data Management tools previously allowed the replication, registration and deletion of files on the grid. For SC3 supplementary functionality has been added to allow bulk replication of data (using FTS) and efficient mass registration to the LFC replica catalog.Provisional performance results have shown that the system developed can meet the expected data replication rate required by the computing model in 2007. This paper details the experience and results of integration and utilisation of DIRAC with the SC3 transfer machinery.

Ultrastructural Characterization of Zika Virus Replication Factories

Directory of Open Access Journals (Sweden)

Mirko Cortese

2017-02-01

Full Text Available Summary: A global concern has emerged with the pandemic spread of Zika virus (ZIKV infections that can cause severe neurological symptoms in adults and newborns. ZIKV is a positive-strand RNA virus replicating in virus-induced membranous replication factories (RFs. Here we used various imaging techniques to investigate the ultrastructural details of ZIKV RFs and their relationship with host cell organelles. Analyses of human hepatic cells and neural progenitor cells infected with ZIKV revealed endoplasmic reticulum (ER membrane invaginations containing pore-like openings toward the cytosol, reminiscent to RFs in Dengue virus-infected cells. Both the MR766 African strain and the H/PF/2013 Asian strain, the latter linked to neurological diseases, induce RFs of similar architecture. Importantly, ZIKV infection causes a drastic reorganization of microtubules and intermediate filaments forming cage-like structures surrounding the viral RF. Consistently, ZIKV replication is suppressed by cytoskeleton-targeting drugs. Thus, ZIKV RFs are tightly linked to rearrangements of the host cell cytoskeleton. : Cortese et al. show that ZIKV infection in both human hepatoma and neuronal progenitor cells induces drastic structural modification of the cellular architecture. Microtubules and intermediate filaments surround the viral replication factory composed of vesicles corresponding to ER membrane invagination toward the ER lumen. Importantly, alteration of microtubule flexibility impairs ZIKV replication. Keywords: Zika virus, flavivirus, human neural progenitor cells, replication factories, replication organelles, microtubules, intermediate filaments, electron microscopy, electron tomography, live-cell imaging

Tombusviruses upregulate phospholipid biosynthesis via interaction between p33 replication protein and yeast lipid sensor proteins during virus replication in yeast

International Nuclear Information System (INIS)

Barajas, Daniel; Xu, Kai; Sharma, Monika; Wu, Cheng-Yu; Nagy, Peter D.

2014-01-01

Positive-stranded RNA viruses induce new membranous structures and promote membrane proliferation in infected cells to facilitate viral replication. In this paper, the authors show that a plant-infecting tombusvirus upregulates transcription of phospholipid biosynthesis genes, such as INO1, OPI3 and CHO1, and increases phospholipid levels in yeast model host. This is accomplished by the viral p33 replication protein, which interacts with Opi1p FFAT domain protein and Scs2p VAP protein. Opi1p and Scs2p are phospholipid sensor proteins and they repress the expression of phospholipid genes. Accordingly, deletion of OPI1 transcription repressor in yeast has a stimulatory effect on TBSV RNA accumulation and enhanced tombusvirus replicase activity in an in vitro assay. Altogether, the presented data convincingly demonstrate that de novo lipid biosynthesis is required for optimal TBSV replication. Overall, this work reveals that a (+)RNA virus reprograms the phospholipid biosynthesis pathway in a unique way to facilitate its replication in yeast cells. - Highlights: • Tombusvirus p33 replication protein interacts with FFAT-domain host protein. • Tombusvirus replication leads to upregulation of phospholipids. • Tombusvirus replication depends on de novo lipid synthesis. • Deletion of FFAT-domain host protein enhances TBSV replication. • TBSV rewires host phospholipid synthesis

Regulation of beta cell replication

DEFF Research Database (Denmark)

Lee, Ying C; Nielsen, Jens Høiriis

2008-01-01

Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

Phosphorylation of NS5A Serine-235 is essential to hepatitis C virus RNA replication and normal replication compartment formation

Energy Technology Data Exchange (ETDEWEB)

Eyre, Nicholas S., E-mail: nicholas.eyre@adelaide.edu.au [School of Biological Sciences and Research Centre for Infectious Diseases, University of Adelaide, Adelaide (Australia); Centre for Cancer Biology, SA Pathology, Adelaide (Australia); Hampton-Smith, Rachel J.; Aloia, Amanda L. [School of Biological Sciences and Research Centre for Infectious Diseases, University of Adelaide, Adelaide (Australia); Centre for Cancer Biology, SA Pathology, Adelaide (Australia); Eddes, James S. [Adelaide Proteomics Centre, School of Biological Sciences, University of Adelaide, Adelaide (Australia); Simpson, Kaylene J. [Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, East Melbourne (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville (Australia); Hoffmann, Peter [Adelaide Proteomics Centre, School of Biological Sciences, University of Adelaide, Adelaide (Australia); Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide (Australia); Beard, Michael R. [School of Biological Sciences and Research Centre for Infectious Diseases, University of Adelaide, Adelaide (Australia); Centre for Cancer Biology, SA Pathology, Adelaide (Australia)

2016-04-15

Hepatitis C virus (HCV) NS5A protein is essential for HCV RNA replication and virus assembly. Here we report the identification of NS5A phosphorylation sites Ser-222, Ser-235 and Thr-348 during an infectious HCV replication cycle and demonstrate that Ser-235 phosphorylation is essential for HCV RNA replication. Confocal microscopy revealed that both phosphoablatant (S235A) and phosphomimetic (S235D) mutants redistribute NS5A to large juxta-nuclear foci that display altered colocalization with known replication complex components. Using electron microscopy (EM) we found that S235D alters virus-induced membrane rearrangements while EM using ‘APEX2’-tagged viruses demonstrated S235D-mediated enrichment of NS5A in irregular membranous foci. Finally, using a customized siRNA screen of candidate NS5A kinases and subsequent analysis using a phospho-specific antibody, we show that phosphatidylinositol-4 kinase III alpha (PI4KIIIα) is important for Ser-235 phosphorylation. We conclude that Ser-235 phosphorylation of NS5A is essential for HCV RNA replication and normal replication complex formation and is regulated by PI4KIIIα. - Highlights: • NS5A residues Ser-222, Ser-235 and Thr-348 are phosphorylated during HCV infection. • Phosphorylation of Ser-235 is essential to HCV RNA replication. • Mutation of Ser-235 alters replication compartment localization and morphology. • Phosphatidylinositol-4 kinase III alpha is important for Ser-235 phosphorylation.

Uncoupling of Sister Replisomes during Eukaryotic DNA Replication

NARCIS (Netherlands)

Yardimci, Hasan; Loveland, Anna B.; Habuchi, Satoshi; van Oijen, Antoine M.; Walter, Johannes C.

2010-01-01

The duplication of eukaryotic genomes involves the replication of DNA from multiple origins of replication. In S phase, two sister replisomes assemble at each active origin, and they replicate DNA in opposite directions. Little is known about the functional relationship between sister replisomes.

Visualizing Single-molecule DNA Replication with Fluorescence Microscopy

NARCIS (Netherlands)

Tanner, Nathan A.; Loparo, Joseph J.; Oijen, Antoine M. van

2009-01-01

We describe a simple fluorescence microscopy-based real-time method for observing DNA replication at the single-molecule level. A circular, forked DNA template is attached to a functionalized glass coverslip and replicated extensively after introduction of replication proteins and nucleotides. The

Dynamic behavior of DNA replication domains

NARCIS (Netherlands)

Manders, E. M.; Stap, J.; Strackee, J.; van Driel, R.; Aten, J. A.

1996-01-01

Like many nuclear processes, DNA replication takes place in distinct domains that are scattered throughout the S-phase nucleus. Recently we have developed a fluorescent double-labeling procedure that allows us to visualize nascent DNA simultaneously with "newborn" DNA that had replicated earlier in

The evolutionary ecology of molecular replicators.

Science.gov (United States)

Nee, Sean

2016-08-01

By reasonable criteria, life on the Earth consists mainly of molecular replicators. These include viruses, transposons, transpovirons, coviruses and many more, with continuous new discoveries like Sputnik Virophage. Their study is inherently multidisciplinary, spanning microbiology, genetics, immunology and evolutionary theory, and the current view is that taking a unified approach has great power and promise. We support this with a new, unified, model of their evolutionary ecology, using contemporary evolutionary theory coupling the Price equation with game theory, studying the consequences of the molecular replicators' promiscuous use of each others' gene products for their natural history and evolutionary ecology. Even at this simple expository level, we can make a firm prediction of a new class of replicators exploiting viruses such as lentiviruses like SIVs, a family which includes HIV: these have been explicitly stated in the primary literature to be non-existent. Closely connected to this departure is the view that multicellular organism immunology is more about the management of chronic infections rather than the elimination of acute ones and new understandings emerging are changing our view of the kind of theatre we ourselves provide for the evolutionary play of molecular replicators. This study adds molecular replicators to bacteria in the emerging field of sociomicrobiology.

A Fuzzy Modeling Approach for Replicated Response Measures Based on Fuzzification of Replications with Descriptive Statistics and Golden Ratio

Directory of Open Access Journals (Sweden)

Özlem TÜRKŞEN

2018-03-01

Full Text Available Some of the experimental designs can be composed of replicated response measures in which the replications cannot be identified exactly and may have uncertainty different than randomness. Then, the classical regression analysis may not be proper to model the designed data because of the violation of probabilistic modeling assumptions. In this case, fuzzy regression analysis can be used as a modeling tool. In this study, the replicated response values are newly formed to fuzzy numbers by using descriptive statistics of replications and golden ratio. The main aim of the study is obtaining the most suitable fuzzy model for replicated response measures through fuzzification of the replicated values by taking into account the data structure of the replications in statistical framework. Here, the response and unknown model coefficients are considered as triangular type-1 fuzzy numbers (TT1FNs whereas the inputs are crisp. Predicted fuzzy models are obtained according to the proposed fuzzification rules by using Fuzzy Least Squares (FLS approach. The performances of the predicted fuzzy models are compared by using Root Mean Squared Error (RMSE criteria. A data set from the literature, called wheel cover component data set, is used to illustrate the performance of the proposed approach and the obtained results are discussed. The calculation results show that the combined formulation of the descriptive statistics and the golden ratio is the most preferable fuzzification rule according to the well-known decision making method, called TOPSIS, for the data set.

Rapid transient production in plants by replicating and non-replicating vectors yields high quality functional anti-HIV antibody.

Directory of Open Access Journals (Sweden)

Frank Sainsbury

2010-11-01

Full Text Available The capacity of plants and plant cells to produce large amounts of recombinant protein has been well established. Due to advantages in terms of speed and yield, attention has recently turned towards the use of transient expression systems, including viral vectors, to produce proteins of pharmaceutical interest in plants. However, the effects of such high level expression from viral vectors and concomitant effects on host cells may affect the quality of the recombinant product.To assess the quality of antibodies transiently expressed to high levels in plants, we have expressed and characterised the human anti-HIV monoclonal antibody, 2G12, using both replicating and non-replicating systems based on deleted versions of Cowpea mosaic virus (CPMV RNA-2. The highest yield (approximately 100 mg/kg wet weight leaf tissue of affinity purified 2G12 was obtained when the non-replicating CPMV-HT system was used and the antibody was retained in the endoplasmic reticulum (ER. Glycan analysis by mass-spectrometry showed that the glycosylation pattern was determined exclusively by whether the antibody was retained in the ER and did not depend on whether a replicating or non-replicating system was used. Characterisation of the binding and neutralisation properties of all the purified 2G12 variants from plants showed that these were generally similar to those of the Chinese hamster ovary (CHO cell-produced 2G12.Overall, the results demonstrate that replicating and non-replicating CPMV-based vectors are able to direct the production of a recombinant IgG similar in activity to the CHO-produced control. Thus, a complex recombinant protein was produced with no apparent effect on its biochemical properties using either high-level expression or viral replication. The speed with which a recombinant pharmaceutical with excellent biochemical characteristics can be produced transiently in plants makes CPMV-based expression vectors an attractive option for

Hepatitis C virus core protein expression leads to biphasic regulation of the p21 cdk inhibitor and modulation of hepatocyte cell cycle

International Nuclear Information System (INIS)

Nguyen, Hau; Mudryj, Maria; Guadalupe, Moraima; Dandekar, Satya

2003-01-01

Hepatitis C virus (HCV) Core protein is implicated in viral pathogenesis by the modulation of hepatocyte gene expression and function. To determine the effect of Core protein on the cell-cycle control of hepatocytes, a HepG2 cell line containing a Flag-tagged Core under the control of an inducible promoter was generated. Initial Core protein expression included the presence of unprocessed (191 aa) and processed (173 aa) forms of the Core proteins with the processed form becoming dominant later. Expression of the 191 aa form of Core protein corresponded to an increase in the expression of the p21, a decrease in cdk2-dependent kinase activity, and a decrease in the percentage of cells in S-phase along with an accumulation of cells in the G 0 /G 1 phase of the cell cycle. As the processed form accumulated, the p21 levels started to decline, suggesting that Core protein regulates p21 expression in a biphasic manner. These findings implicate Core protein in potentially modulating hepatocyte cell cycle differentially in the early stages of infection through biphasic regulation of p21 cdk kinase inhibitor

Dynamics of picornavirus RNA replication within infected cells

DEFF Research Database (Denmark)

Belsham, Graham; Normann, Preben

2008-01-01

Replication of many picornaviruses is inhibited by low concentrations of guanidine. Guanidine-resistant mutants are readily isolated and the mutations map to the coding region for the 2C protein. Using in vitro replication assays it has been determined previously that guanidine blocks the initiat......Replication of many picornaviruses is inhibited by low concentrations of guanidine. Guanidine-resistant mutants are readily isolated and the mutations map to the coding region for the 2C protein. Using in vitro replication assays it has been determined previously that guanidine blocks...... the initiation of negative-strand synthesis. We have now examined the dynamics of RNA replication, measured by quantitative RT-PCR, within cells infected with either swine vesicular disease virus (an enterovirus) or foot-and-mouth disease virus as regulated by the presence or absence of guanidine. Following...... the removal of guanidine from the infected cells, RNA replication occurs after a significant lag phase. This restoration of RNA synthesis requires de novo protein synthesis. Viral RNA can be maintained for at least 72 h within cells in the absence of apparent replication but guanidine-resistant virus can...

Pyrimidine dimers block simian virus 40 replication forks

International Nuclear Information System (INIS)

Berger, C.A.; Edenberg, H.J.

1986-01-01

UV light produces lesions, predominantly pyrimidine dimers, which inhibit DNA replication in mammalian cells. The mechanism of inhibition is controversial: is synthesis of a daughter strand halted at a lesion while the replication fork moves on and reinitiates downstream, or is fork progression itself blocked for some time at the site of a lesion? We directly addressed this question by using electron microscopy to examine the distances of replication forks from the origin in unirradiated and UV-irradiated simian virus 40 chromosomes. If UV lesions block replication fork progression, the forks should be asymmetrically located in a large fraction of the irradiated molecules; if replication forks move rapidly past lesions, the forks should be symmetrically located. A large fraction of the simian virus 40 replication forks in irradiated molecules were asymmetrically located, demonstrating that UV lesions present at the frequency of pyrimidine dimers block replication forks. As a mechanism for this fork blockage, we propose that polymerization of the leading strand makes a significant contribution to the energetics of fork movement, so any lesion in the template for the leading strand which blocks polymerization should also block fork movement

Autonomous model protocell division driven by molecular replication.

Science.gov (United States)

Taylor, J W; Eghtesadi, S A; Points, L J; Liu, T; Cronin, L

2017-08-10

The coupling of compartmentalisation with molecular replication is thought to be crucial for the emergence of the first evolvable chemical systems. Minimal artificial replicators have been designed based on molecular recognition, inspired by the template copying of DNA, but none yet have been coupled to compartmentalisation. Here, we present an oil-in-water droplet system comprising an amphiphilic imine dissolved in chloroform that catalyses its own formation by bringing together a hydrophilic and a hydrophobic precursor, which leads to repeated droplet division. We demonstrate that the presence of the amphiphilic replicator, by lowering the interfacial tension between droplets of the reaction mixture and the aqueous phase, causes them to divide. Periodic sampling by a droplet-robot demonstrates that the extent of fission is increased as the reaction progresses, producing more compartments with increased self-replication. This bridges a divide, showing how replication at the molecular level can be used to drive macroscale droplet fission.Coupling compartmentalisation and molecular replication is essential for the development of evolving chemical systems. Here the authors show an oil-in-water droplet containing a self-replicating amphiphilic imine that can undergo repeated droplet division.

Initiation preference at a yeast origin of replication.

Science.gov (United States)

Brewer, B J; Fangman, W L

1994-04-12

Replication origins in the yeast Saccharomyces cerevisiae are identified as autonomous replication sequence (ARS) elements. To examine the effect of origin density on replication initiation, we have analyzed the replication of a plasmid that contains two copies of the same origin, ARS1. The activation of origins and the direction that replication forks move through flanking sequences can be physically determined by analyzing replication intermediates on two-dimensional agarose gels. We find that only one of the two identical ARSs on the plasmid initiates replication on any given plasmid molecule; that is, this close spacing of ARSs results in an apparent interference between the potential origins. Moreover, in the particular plasmid that we constructed, one of the two identical copies of ARS1 is used four times more frequently than the other one. These results show that the plasmid context is critical for determining the preferred origin. This origin preference is also exhibited when the tandem copies of ARS1 are introduced into a yeast chromosome. The sequences responsible for establishing the origin preference have been identified by deletion analysis and are found to reside in a portion of the yeast URA3 gene.

Gene organization inside replication domains in mammalian genomes

Science.gov (United States)

Zaghloul, Lamia; Baker, Antoine; Audit, Benjamin; Arneodo, Alain

2012-11-01

We investigate the large-scale organization of human genes with respect to "master" replication origins that were previously identified as bordering nucleotide compositional skew domains. We separate genes in two categories depending on their CpG enrichment at the promoter which can be considered as a marker of germline DNA methylation. Using expression data in mouse, we confirm that CpG-rich genes are highly expressed in germline whereas CpG-poor genes are in a silent state. We further show that, whether tissue-specific or broadly expressed (housekeeping genes), the CpG-rich genes are over-represented close to the replication skew domain borders suggesting some coordination of replication and transcription. We also reveal that the transcription of the longest CpG-rich genes is co-oriented with replication fork progression so that the promoter of these transcriptionally active genes be located into the accessible open chromatin environment surrounding the master replication origins that border the replication skew domains. The observation of a similar gene organization in the mouse genome confirms the interplay of replication, transcription and chromatin structure as the cornerstone of mammalian genome architecture.

Mapping replication origins in yeast chromosomes.

Science.gov (United States)

Brewer, B J; Fangman, W L

1991-07-01

The replicon hypothesis, first proposed in 1963 by Jacob and Brenner, states that DNA replication is controlled at sites called origins. Replication origins have been well studied in prokaryotes. However, the study of eukaryotic chromosomal origins has lagged behind, because until recently there has been no method for reliably determining the identity and location of origins from eukaryotic chromosomes. Here, we review a technique we developed with the yeast Saccharomyces cerevisiae that allows both the mapping of replication origins and an assessment of their activity. Two-dimensional agarose gel electrophoresis and Southern hybridization with total genomic DNA are used to determine whether a particular restriction fragment acquires the branched structure diagnostic of replication initiation. The technique has been used to localize origins in yeast chromosomes and assess their initiation efficiency. In some cases, origin activation is dependent upon the surrounding context. The technique is also being applied to a variety of eukaryotic organisms.

Assembly of Slx4 signaling complexes behind DNA replication forks.

Science.gov (United States)

Balint, Attila; Kim, TaeHyung; Gallo, David; Cussiol, Jose Renato; Bastos de Oliveira, Francisco M; Yimit, Askar; Ou, Jiongwen; Nakato, Ryuichiro; Gurevich, Alexey; Shirahige, Katsuhiko; Smolka, Marcus B; Zhang, Zhaolei; Brown, Grant W

2015-08-13

Obstructions to replication fork progression, referred to collectively as DNA replication stress, challenge genome stability. In Saccharomyces cerevisiae, cells lacking RTT107 or SLX4 show genome instability and sensitivity to DNA replication stress and are defective in the completion of DNA replication during recovery from replication stress. We demonstrate that Slx4 is recruited to chromatin behind stressed replication forks, in a region that is spatially distinct from that occupied by the replication machinery. Slx4 complex formation is nucleated by Mec1 phosphorylation of histone H2A, which is recognized by the constitutive Slx4 binding partner Rtt107. Slx4 is essential for recruiting the Mec1 activator Dpb11 behind stressed replication forks, and Slx4 complexes are important for full activity of Mec1. We propose that Slx4 complexes promote robust checkpoint signaling by Mec1 by stably recruiting Dpb11 within a discrete domain behind the replication fork, during DNA replication stress. © 2015 The Authors.

Checkpoint responses to replication stalling: inducing tolerance and preventing mutagenesis

Energy Technology Data Exchange (ETDEWEB)

Kai, Mihoko; Wang, Teresa S.-F

2003-11-27

Replication mutants often exhibit a mutator phenotype characterized by point mutations, single base frameshifts, and the deletion or duplication of sequences flanked by homologous repeats. Mutation in genes encoding checkpoint proteins can significantly affect the mutator phenotype. Here, we use fission yeast (Schizosaccharomyces pombe) as a model system to discuss the checkpoint responses to replication perturbations induced by replication mutants. Checkpoint activation induced by a DNA polymerase mutant, aside from delay of mitotic entry, up-regulates the translesion polymerase DinB (Pol{kappa}). Checkpoint Rad9-Rad1-Hus1 (9-1-1) complex, which is loaded onto chromatin by the Rad17-Rfc2-5 checkpoint complex in response to replication perturbation, recruits DinB onto chromatin to generate the point mutations and single nucleotide frameshifts in the replication mutator. This chain of events reveals a novel checkpoint-induced tolerance mechanism that allows cells to cope with replication perturbation, presumably to make possible restarting stalled replication forks. Fission yeast Cds1 kinase plays an essential role in maintaining DNA replication fork stability in the face of DNA damage and replication fork stalling. Cds1 kinase is known to regulate three proteins that are implicated in maintaining replication fork stability: Mus81-Eme1, a hetero-dimeric structure-specific endonuclease complex; Rqh1, a RecQ-family helicase involved in suppressing inappropriate recombination during replication; and Rad60, a protein required for recombinational repair during replication. These Cds1-regulated proteins are thought to cooperatively prevent mutagenesis and maintain replication fork stability in cells under replication stress. These checkpoint-regulated processes allow cells to survive replication perturbation by preventing stalled replication forks from degenerating into deleterious DNA structures resulting in genomic instability and cancer development.

Checkpoint responses to replication stalling: inducing tolerance and preventing mutagenesis

International Nuclear Information System (INIS)

Kai, Mihoko; Wang, Teresa S.-F.

2003-01-01

Replication mutants often exhibit a mutator phenotype characterized by point mutations, single base frameshifts, and the deletion or duplication of sequences flanked by homologous repeats. Mutation in genes encoding checkpoint proteins can significantly affect the mutator phenotype. Here, we use fission yeast (Schizosaccharomyces pombe) as a model system to discuss the checkpoint responses to replication perturbations induced by replication mutants. Checkpoint activation induced by a DNA polymerase mutant, aside from delay of mitotic entry, up-regulates the translesion polymerase DinB (Polκ). Checkpoint Rad9-Rad1-Hus1 (9-1-1) complex, which is loaded onto chromatin by the Rad17-Rfc2-5 checkpoint complex in response to replication perturbation, recruits DinB onto chromatin to generate the point mutations and single nucleotide frameshifts in the replication mutator. This chain of events reveals a novel checkpoint-induced tolerance mechanism that allows cells to cope with replication perturbation, presumably to make possible restarting stalled replication forks. Fission yeast Cds1 kinase plays an essential role in maintaining DNA replication fork stability in the face of DNA damage and replication fork stalling. Cds1 kinase is known to regulate three proteins that are implicated in maintaining replication fork stability: Mus81-Eme1, a hetero-dimeric structure-specific endonuclease complex; Rqh1, a RecQ-family helicase involved in suppressing inappropriate recombination during replication; and Rad60, a protein required for recombinational repair during replication. These Cds1-regulated proteins are thought to cooperatively prevent mutagenesis and maintain replication fork stability in cells under replication stress. These checkpoint-regulated processes allow cells to survive replication perturbation by preventing stalled replication forks from degenerating into deleterious DNA structures resulting in genomic instability and cancer development

Hyperthermia stimulates HIV-1 replication.

Directory of Open Access Journals (Sweden)

Ferdinand Roesch

Full Text Available HIV-infected individuals may experience fever episodes. Fever is an elevation of the body temperature accompanied by inflammation. It is usually beneficial for the host through enhancement of immunological defenses. In cultures, transient non-physiological heat shock (42-45°C and Heat Shock Proteins (HSPs modulate HIV-1 replication, through poorly defined mechanisms. The effect of physiological hyperthermia (38-40°C on HIV-1 infection has not been extensively investigated. Here, we show that culturing primary CD4+ T lymphocytes and cell lines at a fever-like temperature (39.5°C increased the efficiency of HIV-1 replication by 2 to 7 fold. Hyperthermia did not facilitate viral entry nor reverse transcription, but increased Tat transactivation of the LTR viral promoter. Hyperthermia also boosted HIV-1 reactivation in a model of latently-infected cells. By imaging HIV-1 transcription, we further show that Hsp90 co-localized with actively transcribing provirus, and this phenomenon was enhanced at 39.5°C. The Hsp90 inhibitor 17-AAG abrogated the increase of HIV-1 replication in hyperthermic cells. Altogether, our results indicate that fever may directly stimulate HIV-1 replication, in a process involving Hsp90 and facilitation of Tat-mediated LTR activity.

46 CFR 160.176-23 - Marking.

Science.gov (United States)

2010-10-01

... of the vessel. (2) The type of vessel. (3) Specific purpose or limitation approved by the Coast Guard...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Inflatable Lifejackets § 160.176-23 Marking. (a) General. Each inflatable lifejacket must be marked with the information required by this section. Each marking must be...

Replication and Robustness in Developmental Research

Science.gov (United States)

Duncan, Greg J.; Engel, Mimi; Claessens, Amy; Dowsett, Chantelle J.

2014-01-01

Replications and robustness checks are key elements of the scientific method and a staple in many disciplines. However, leading journals in developmental psychology rarely include explicit replications of prior research conducted by different investigators, and few require authors to establish in their articles or online appendices that their key…

Biomarkers of replicative senescence revisited

DEFF Research Database (Denmark)

Nehlin, Jan

2016-01-01

Biomarkers of replicative senescence can be defined as those ultrastructural and physiological variations as well as molecules whose changes in expression, activity or function correlate with aging, as a result of the gradual exhaustion of replicative potential and a state of permanent cell cycle...... arrest. The biomarkers that characterize the path to an irreversible state of cell cycle arrest due to proliferative exhaustion may also be shared by other forms of senescence-inducing mechanisms. Validation of senescence markers is crucial in circumstances where quiescence or temporary growth arrest may...... be triggered or is thought to be induced. Pre-senescence biomarkers are also important to consider as their presence indicate that induction of aging processes is taking place. The bona fide pathway leading to replicative senescence that has been extensively characterized is a consequence of gradual reduction...

On-road Bicycle Pavement Markings

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

Marks of Metal Copenhell

DEFF Research Database (Denmark)

2015-01-01

Planchebaseret udendørs udstilling på musikfestivalen Copenhell 18-20/6 2015. En mindre udgave af udstillingen Marks of Metal - Logodesign og visualitet i heavy metal. Udarbejdet i samarbejde med Mediemuseet.......Planchebaseret udendørs udstilling på musikfestivalen Copenhell 18-20/6 2015. En mindre udgave af udstillingen Marks of Metal - Logodesign og visualitet i heavy metal. Udarbejdet i samarbejde med Mediemuseet....

Enzymes involved in organellar DNA replication in photosynthetic eukaryotes.

Science.gov (United States)

Moriyama, Takashi; Sato, Naoki

2014-01-01

Plastids and mitochondria possess their own genomes. Although the replication mechanisms of these organellar genomes remain unclear in photosynthetic eukaryotes, several organelle-localized enzymes related to genome replication, including DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, primer removal enzyme, and several DNA recombination-related enzymes, have been identified. In the reference Eudicot plant Arabidopsis thaliana, the replication-related enzymes of plastids and mitochondria are similar because many of them are dual targeted to both organelles, whereas in the red alga Cyanidioschyzon merolae, plastids and mitochondria contain different replication machinery components. The enzymes involved in organellar genome replication in green plants and red algae were derived from different origins, including proteobacterial, cyanobacterial, and eukaryotic lineages. In the present review, we summarize the available data for enzymes related to organellar genome replication in green plants and red algae. In addition, based on the type and distribution of replication enzymes in photosynthetic eukaryotes, we discuss the transitional history of replication enzymes in the organelles of plants.

Circulatory Markings at Double-Lane Traffic Roundabout.

NARCIS (Netherlands)

Bie, Jing; Lo, Hong K.; Wong, S.C.

2008-01-01

This paper compares two types of circulatory markings at a double-lane traffic roundabout: the concentric marking scheme and the Alberta marking scheme. The effects of these two marking schemes on drivers' lane choice behavior, delay, and safety, are compared based on data collected from before and

Viral hijacking of a replicative helicase loader and its implications for helicase loading control and phage replication

Energy Technology Data Exchange (ETDEWEB)

Hood, Iris V.; Berger, James M.

2016-05-31

Replisome assembly requires the loading of replicative hexameric helicases onto origins by AAA+ ATPases. How loader activity is appropriately controlled remains unclear. Here, we use structural and biochemical analyses to establish how an antimicrobial phage protein interferes with the function of theStaphylococcus aureusreplicative helicase loader, DnaI. The viral protein binds to the loader’s AAA+ ATPase domain, allowing binding of the host replicative helicase but impeding loader self-assembly and ATPase activity. Close inspection of the complex highlights an unexpected locus for the binding of an interdomain linker element in DnaI/DnaC-family proteins. We find that the inhibitor protein is genetically coupled to a phage-encoded homolog of the bacterial helicase loader, which we show binds to the host helicase but not to the inhibitor itself. These findings establish a new approach by which viruses can hijack host replication processes and explain how loader activity is internally regulated to prevent aberrant auto-association.

7 CFR 160.32 - Marking containers.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Marking containers. 160.32 Section 160.32 Agriculture... STANDARDS FOR NAVAL STORES Analysis, Inspection, and Grading on Request § 160.32 Marking containers. The interested person shall provide any labor necessary for marking the containers, after the contents have been...

46 CFR 122.602 - Hull markings.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Hull markings. 122.602 Section 122.602 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150....602 Hull markings. (a) Each vessel must be marked as required by part 67, subpart I, of this chapter...

Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity when heat removing from a power transformer of combined heat and power station

Directory of Open Access Journals (Sweden)

Nurpeiis Atlant

2017-01-01

Full Text Available Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity was conducted when heat removing from an oil tank of a power transformer of combined heat and power station (CHP. The power transformer cooling system by the closed biphasic thermosyphon was proposed. The mathematical modeling of heat transfer and phase transitions of coolant in the thermosyphon was performed. The problem of heat transfer is formulated in dimensionless variables “velocity vorticity vector – current function – temperature” and solved by finite difference method. As a result of numerical simulation it is found that an increase in the vapor channel length from 0.15m to 1m leads to increasing the temperature difference by 3.5 K.

The transcription elongation factor Bur1-Bur2 interacts with replication protein A and maintains genome stability during replication stress

DEFF Research Database (Denmark)

Clausing, Emanuel; Mayer, Andreas; Chanarat, Sittinan

2010-01-01

Multiple DNA-associated processes such as DNA repair, replication, and recombination are crucial for the maintenance of genome integrity. Here, we show a novel interaction between the transcription elongation factor Bur1-Bur2 and replication protein A (RPA), the eukaryotic single-stranded DNA......-binding protein with functions in DNA repair, recombination, and replication. Bur1 interacted via its C-terminal domain with RPA, and bur1-¿C mutants showed a deregulated DNA damage response accompanied by increased sensitivity to DNA damage and replication stress as well as increased levels of persisting Rad52...... foci. Interestingly, the DNA damage sensitivity of an rfa1 mutant was suppressed by bur1 mutation, further underscoring a functional link between these two protein complexes. The transcription elongation factor Bur1-Bur2 interacts with RPA and maintains genome integrity during DNA replication stress....

Modeling DNA Replication.

Science.gov (United States)

Bennett, Joan

1998-01-01

Recommends the use of a model of DNA made out of Velcro to help students visualize the steps of DNA replication. Includes a materials list, construction directions, and details of the demonstration using the model parts. (DDR)

Distinct functions of human RecQ helicases during DNA replication.

Science.gov (United States)

Urban, Vaclav; Dobrovolna, Jana; Janscak, Pavel

2017-06-01

DNA replication is the most vulnerable process of DNA metabolism in proliferating cells and therefore it is tightly controlled and coordinated with processes that maintain genomic stability. Human RecQ helicases are among the most important factors involved in the maintenance of replication fork integrity, especially under conditions of replication stress. RecQ helicases promote recovery of replication forks being stalled due to different replication roadblocks of either exogenous or endogenous source. They prevent generation of aberrant replication fork structures and replication fork collapse, and are involved in proper checkpoint signaling. The essential role of human RecQ helicases in the genome maintenance during DNA replication is underlined by association of defects in their function with cancer predisposition. Copyright © 2016 Elsevier B.V. All rights reserved.

Evolution of complexity in RNA-like replicator systems

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Hogeweg Paulien

2008-03-01

Full Text Available Abstract Background The evolution of complexity is among the most important questions in biology. The evolution of complexity is often observed as the increase of genetic information or that of the organizational complexity of a system. It is well recognized that the formation of biological organization – be it of molecules or ecosystems – is ultimately instructed by the genetic information, whereas it is also true that the genetic information is functional only in the context of the organization. Therefore, to obtain a more complete picture of the evolution of complexity, we must study the evolution of both information and organization. Results Here we investigate the evolution of complexity in a simulated RNA-like replicator system. The simplicity of the system allows us to explicitly model the genotype-phenotype-interaction mapping of individual replicators, whereby we avoid preconceiving the functionality of genotypes (information or the ecological organization of replicators in the model. In particular, the model assumes that interactions among replicators – to replicate or to be replicated – depend on their secondary structures and base-pair matching. The results showed that a population of replicators, originally consisting of one genotype, evolves to form a complex ecosystem of up to four species. During this diversification, the species evolve through acquiring unique genotypes with distinct ecological functionality. The analysis of this diversification reveals that parasitic replicators, which have been thought to destabilize the replicator's diversity, actually promote the evolution of diversity through generating a novel "niche" for catalytic replicators. This also makes the current replicator system extremely stable upon the evolution of parasites. The results also show that the stability of the system crucially depends on the spatial pattern formation of replicators. Finally, the evolutionary dynamics is shown to

Stretch Marks

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... completely without the help of a dermatologist or plastic surgeon. These doctors may use one of many types of treatments — from actual surgery to techniques like microdermabrasion and laser treatment — to reduce the appearance of stretch marks. These techniques are ...

Molecular Mechanisms of DNA Replication Checkpoint Activation

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Bénédicte Recolin

2014-03-01

Full Text Available The major challenge of the cell cycle is to deliver an intact, and fully duplicated, genetic material to the daughter cells. To this end, progression of DNA synthesis is monitored by a feedback mechanism known as replication checkpoint that is untimely linked to DNA replication. This signaling pathway ensures coordination of DNA synthesis with cell cycle progression. Failure to activate this checkpoint in response to perturbation of DNA synthesis (replication stress results in forced cell division leading to chromosome fragmentation, aneuploidy, and genomic instability. In this review, we will describe current knowledge of the molecular determinants of the DNA replication checkpoint in eukaryotic cells and discuss a model of activation of this signaling pathway crucial for maintenance of genomic stability.

Core-shell nanoreactors for efficient aqueous biphasic catalysis.

Science.gov (United States)

Zhang, Xuewei; Cardozo, Andrés F; Chen, Si; Zhang, Wenjing; Julcour, Carine; Lansalot, Muriel; Blanco, Jean-François; Gayet, Florence; Delmas, Henri; Charleux, Bernadette; Manoury, Eric; D'Agosto, Franck; Poli, Rinaldo

2014-11-17

Water-borne phosphine-functionalized core-cross-linked micelles (CCM) consisting of a hydrophobic core and a hydrophilic shell were obtained as stable latexes by reversible addition-fragmentation chain transfer (RAFT) in water in a one-pot, three-step process. Initial homogeneous aqueous-phase copolymerization of methacrylic acid (MAA) and poly(ethylene oxide) methyl ether methacrylate (PEOMA) is followed by copolymerization of styrene (S) and 4-diphenylphosphinostyrene (DPPS), yielding P(MAA-co-PEOMA)-b-P(S-co-DPPS) amphiphilic block copolymer micelles (M) by polymerization-induced self-assembly (PISA), and final micellar cross-linking with a mixture of S and diethylene glycol dimethacrylate. The CCM were characterized by dynamic light scattering and NMR spectroscopy to evaluate size, dispersity, stability, and the swelling ability of various organic substrates. Coordination of [Rh(acac)(CO)2 ] (acac=acetylacetonate) to the core-confined phosphine groups was rapid and quantitative. The CCM and M latexes were then used, in combination with [Rh(acac)(CO)2 ], to catalyze the aqueous biphasic hydroformylation of 1-octene, in which they showed high activity, recyclability, protection of the activated Rh center by the polymer scaffold, and low Rh leaching. The CCM latex gave slightly lower catalytic activity but significantly less Rh leaching than the M latex. A control experiment conducted in the presence of the sulfoxantphos ligand pointed to the action of the CCM as catalytic nanoreactors with substrate and product transport into and out of the polymer core, rather than as a surfactant in interfacial catalysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new MCM modification cycle regulates DNA replication initiation.

Science.gov (United States)

Wei, Lei; Zhao, Xiaolan

2016-03-01

The MCM DNA helicase is a central regulatory target during genome replication. MCM is kept inactive during G1, and it initiates replication after being activated in S phase. During this transition, the only known chemical change to MCM is the gain of multisite phosphorylation that promotes cofactor recruitment. Because replication initiation is intimately linked to multiple biological cues, additional changes to MCM can provide further regulatory points. Here, we describe a yeast MCM SUMOylation cycle that regulates replication. MCM subunits undergo SUMOylation upon loading at origins in G1 before MCM phosphorylation. MCM SUMOylation levels then decline as MCM phosphorylation levels rise, thus suggesting an inhibitory role of MCM SUMOylation during replication. Indeed, increasing MCM SUMOylation impairs replication initiation, partly through promoting the recruitment of a phosphatase that decreases MCM phosphorylation and activation. We propose that MCM SUMOylation counterbalances kinase-based regulation, thus ensuring accurate control of replication initiation.

Appraisal of the sensitising potential of orally and dermally administered mercaptobenzothiazole by a biphasic protocol of the local lymph node assay.

Science.gov (United States)

Ahuja, Varun; Wanner, Reinhard; Platzek, Thomas; Stahlmann, Ralf

2009-10-01

Mercaptobenzothiazole (MBT) is used while manufacturing natural rubber products. Our study deals with assessing its allergenic potential following dermal and oral routes of exposure, using a biphasic local lymph node assay (LLNA). Female Balb/c mice were treated with MBT (dermally 3, 10, 30% concentrations in DMSO; orally 1, 10, 100 mg/kg doses in corn oil) on the back (dermal study) or through oral administration (oral study) on days 1-3 followed by auricular application of 3, 10 and 30% concentrations, respectively, on days 15-17. End points determined on day 19 included ear thickness, ear punch weight, lymph node weight, lymph node cell count, and lymphocyte subpopulations (CD4+, CD8+, CD45+). After dermal application of 3% or 10% solution, a significant increase in cell count and lymph node weight along with significant decrease in CD8+ cells was observed. After initial oral administration of 1 mg/kg, we noticed a significant amplification in cell count. Following oral administration of 10 mg/kg, we observed a similar increase in cell count and lymph node weight. The results of our study show that the modified biphasic LLNA protocol can be used to study the sensitising potential of a compound also following the oral route of exposure.

Diagnostic accuracy of C-arm CT during selective transcatheter angiography for hepatocellular carcinoma: comparison with intravenous contrast-enhanced, biphasic, dynamic MDCT

Energy Technology Data Exchange (ETDEWEB)

Higashihara, Hiroki; Osuga, Keigo; Onishi, Hiromitsu; Nakamoto, Atsushi; Tsuboyama, Takahiro; Maeda, Noboru; Hori, Masatoshi; Kim, Tonsok; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Suita, Osaka (Japan)

2012-04-15

This study was aimed to compare the accuracy, sensitivity, and positive predictive value of C-arm CT (CACT) during selective transcatheter angiography with those of multidetector CT (MDCT) in the detection of hepatocellular carcinoma (HCC). In this prospective study, 30 patients (mean age, 73 years) with unresectable HCC were examined with CACT before chemoembolisation. Images of a combination of CACT during arterial portography (CACTAP) and dual-phase CACT during hepatic arteriography (CACTHA) was obtained and images of intravenous contrast-enhanced, biphasic, dynamic, MDCT was also obtained beforehand. Three blinded observers independently reviewed CACT and MDCT. Diagnostic accuracy was evaluated by the alternative free-response receiver operating characteristic (AFROC) method. Sensitivities and positive predictive values (PPV) were analyzed with the paired t-test. In the mean area under the AFROC curve (Az), there was no significant difference between MDCT and CACT (MDCT, mean Az value, 0.83; CACT, 0.85, respectively) (P = 0.32). There was also no significant difference between the two techniques in sensitivity (MDCT, mean 0.65; CACT, 0.60) and PPV (MDCT, mean 0.98; CACT, 0.97) (P = 0.40, P = 0.68, respectively). The diagnostic accuracy of CACT was equivalent to that of biphasic CT in the diagnosis of HCC. (orig.)

The Combination of GIS and Biphasic to Better Predict In Vivo Dissolution of BCS Class IIb Drugs, Ketoconazole and Raloxifene.

Science.gov (United States)

Tsume, Yasuhiro; Igawa, Naoto; Drelich, Adam J; Amidon, Gregory E; Amidon, Gordon L

2018-01-01

The formulation developments and the in vivo assessment of Biopharmaceutical Classification System (BCS) class II drugs are challenging due to their low solubility and high permeability in the human gastrointestinal (GI) tract. Since the GI environment influences the drug dissolution of BCS class II drugs, the human GI characteristics should be incorporated into the in vitro dissolution system to predict bioperformance of BCS class II drugs. An absorptive compartment may be important in dissolution apparatus for BCS class II drugs, especially for bases (BCS IIb) because of high permeability, precipitation, and supersaturation. Thus, the in vitro dissolution system with an absorptive compartment may help predicting the in vivo phenomena of BCS class II drugs better than compendial dissolution apparatuses. In this study, an absorptive compartment (a biphasic device) was introduced to a gastrointestinal simulator. This addition was evaluated if this in vitro system could improve the prediction of in vivo dissolution for BCS class IIb drugs, ketoconazole and raloxifene, and subsequent absorption. The gastrointestinal simulator is a practical in vivo predictive tool and exhibited an improved in vivo prediction utilizing the biphasic format and thus a better tool for evaluating the bioperformance of BCS class IIb drugs than compendial apparatuses. Copyright © 2018. Published by Elsevier Inc.

High contrast laser marking of alumina

Science.gov (United States)

Penide, J.; Quintero, F.; Riveiro, A.; Fernández, A.; del Val, J.; Comesaña, R.; Lusquiños, F.; Pou, J.

2015-05-01

Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks.

A CI-Independent Form of Replicative Inhibition: Turn Off of Early Replication of Bacteriophage Lambda

Science.gov (United States)

Hayes, Sidney; Horbay, Monique A.; Hayes, Connie

2012-01-01

Several earlier studies have described an unusual exclusion phenotype exhibited by cells with plasmids carrying a portion of the replication region of phage lambda. Cells exhibiting this inhibition phenotype (IP) prevent the plating of homo-immune and hybrid hetero-immune lambdoid phages. We have attempted to define aspects of IP, and show that it is directed to repλ phages. IP was observed in cells with plasmids containing a λ DNA fragment including oop, encoding a short OOP micro RNA, and part of the lambda origin of replication, oriλ, defined by iteron sequences ITN1-4 and an adjacent high AT-rich sequence. Transcription of the intact oop sequence from its promoter, pO is required for IP, as are iterons ITN3–4, but not the high AT-rich portion of oriλ. The results suggest that IP silencing is directed to theta mode replication initiation from an infecting repλ genome, or an induced repλ prophage. Phage mutations suppressing IP, i.e., Sip, map within, or adjacent to cro or in O, or both. Our results for plasmid based IP suggest the hypothesis that there is a natural mechanism for silencing early theta-mode replication initiation, i.e. the buildup of λ genomes with oop + oriλ+ sequence. PMID:22590552

27 CFR 28.123 - Export marks.

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2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.123..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In addition... filled under the provisions of part 24 of this chapter, the proprietor shall mark the word “Export” on...

Synthesis and Cell Seeding Assessment of Novel Biphasic Nano Powder in the CaO–MgO–SiO2 System for Bone Implant Application

Directory of Open Access Journals (Sweden)

Kazem Marzban

2017-02-01

Full Text Available Objective(s: CaO–MgO–SiO2 system bioceramics possess good characteristics for hard tissue engineering applications. The aim of the study was to synthesize the nano powder by using a sol-gel method and evaluate of bioactivity in the cells culture. Methods: To characterize of powder X-ray diffraction (XRD, transmission electron microscopy (TEM and to evaluate the bioactivity sample cell seeding and methylthiazol tetrazolium (MTT assay were performed. Results: X-ray diffraction (XRD analysis showed that the biphasic powder was obtained at 1300°C for 2 h by using a sol-gel method. Transmission electron microscopy (TEM image showed that powder particle size was about 45 nm. Besides, cell culture results indicated that the percentage of viability values was increased by the extension of period. Conclusions: found that the sample is cytocompatible and has cell proliferation potential in culture medium. The present study demonstrates that, the biphasic CaO–MgO–SiO2 system can be used to achieve novel bioactive materials for bone implant application.

Replication of cultured lung epithelial cells

International Nuclear Information System (INIS)

Guzowski, D.; Bienkowski, R.

1986-01-01

The authors have investigated the conditions necessary to support replication of lung type 2 epithelial cells in culture. Cells were isolated from mature fetal rabbit lungs (29d gestation) and cultured on feeder layers of mitotically inactivated 3T3 fibroblasts. The epithelial nature of the cells was demonstrated by indirect immunofluorescent staining for keratin and by polyacid dichrome stain. Ultrastructural examination during the first week showed that the cells contained myofilaments, microvilli and lamellar bodies (markers for type 2 cells). The following changes were observed after the first week: increase in cell size; loss of lamellar bodies and appearance of multivesicular bodies; increase in rough endoplasmic reticulum and golgi; increase in tonafilaments and well-defined junctions. General cell morphology was good for up to 10 wk. Cells cultured on plastic surface degenerated after 1 wk. Cell replication was assayed by autoradiography of cultures exposed to ( 3 H)-thymidine and by direct cell counts. The cells did not replicate during the first week; however, between 2-10 wk the cells incorporated the label and went through approximately 6 population doublings. They have demonstrated that lung alveolar epithelial cells can replicate in culture if they are maintained on an appropriate substrate. The coincidence of ability to replicate and loss of markers for differentiation may reflect the dichotomy between growth and differentiation commonly observed in developing systems

Spacetime replication of continuous variable quantum information

International Nuclear Information System (INIS)

Hayden, Patrick; Nezami, Sepehr; Salton, Grant; Sanders, Barry C

2016-01-01

The theory of relativity requires that no information travel faster than light, whereas the unitarity of quantum mechanics ensures that quantum information cannot be cloned. These conditions provide the basic constraints that appear in information replication tasks, which formalize aspects of the behavior of information in relativistic quantum mechanics. In this article, we provide continuous variable (CV) strategies for spacetime quantum information replication that are directly amenable to optical or mechanical implementation. We use a new class of homologically constructed CV quantum error correcting codes to provide efficient solutions for the general case of information replication. As compared to schemes encoding qubits, our CV solution requires half as many shares per encoded system. We also provide an optimized five-mode strategy for replicating quantum information in a particular configuration of four spacetime regions designed not to be reducible to previously performed experiments. For this optimized strategy, we provide detailed encoding and decoding procedures using standard optical apparatus and calculate the recovery fidelity when finite squeezing is used. As such we provide a scheme for experimentally realizing quantum information replication using quantum optics. (paper)

COPI is required for enterovirus 71 replication.

Directory of Open Access Journals (Sweden)

Jianmin Wang

Full Text Available Enterovirus 71 (EV71, a member of the Picornaviridae family, is found in Asian countries where it causes a wide range of human diseases. No effective therapy is available for the treatment of these infections. Picornaviruses undergo RNA replication in association with membranes of infected cells. COPI and COPII have been shown to be involved in the formation of picornavirus-induced vesicles. Replication of several picornaviruses, including poliovirus and Echovirus 11 (EV11, is dependent on COPI or COPII. Here, we report that COPI, but not COPII, is required for EV71 replication. Replication of EV71 was inhibited by brefeldin A and golgicide A, inhibitors of COPI activity. Furthermore, we found EV71 2C protein interacted with COPI subunits by co-immunoprecipitation and GST pull-down assay, indicating that COPI coatomer might be directed to the viral replication complex through viral 2C protein. Additionally, because the pathway is conserved among different species of enteroviruses, it may represent a novel target for antiviral therapies.

DNA replication after mutagenic treatment in Hordeum vulgare.

Science.gov (United States)

Kwasniewska, Jolanta; Kus, Arita; Swoboda, Monika; Braszewska-Zalewska, Agnieszka

2016-12-01

The temporal and spatial properties of DNA replication in plants related to DNA damage and mutagenesis is poorly understood. Experiments were carried out to explore the relationships between DNA replication, chromatin structure and DNA damage in nuclei from barley root tips. We quantitavely analysed the topological organisation of replication foci using pulse EdU labelling during the S phase and its relationship with the DNA damage induced by mutagenic treatment with maleic hydrazide (MH), nitroso-N-methyl-urea (MNU) and gamma ray. Treatment with mutagens did not change the characteristic S-phase patterns in the nuclei; however, the frequencies of the S-phase-labelled cells after treatment differed from those observed in the control cells. The analyses of DNA replication in barley nuclei were extended to the micronuclei induced by mutagens. Replication in the chromatin of the micronuclei was rare. The results of simultanous TUNEL reaction to identify cells with DNA strand breaks and the labelling of the S-phase cells with EdU revealed the possibility of DNA replication occurring in damaged nuclei. For the first time, the intensity of EdU fluorescence to study the rate of DNA replication was analysed. Copyright © 2016 Elsevier B.V. All rights reserved.

Stereoisomeric products of electrochemical reduction of heterocyclic Fischer aminocarbene Cr(0) complexes. Development of the electrochemistry-mass spectrometry tandem approach using biphasic (acetonitrile-hexane) preparative electrolysis

Czech Academy of Sciences Publication Activity Database

Metelková, R.; Hoskovcová, I.; Polášek, Miroslav; Urban, Jiří; David, T.; Ludvík, Jiří

2015-01-01

Roč. 162, APR 2015 (2015), s. 17-23 ISSN 0013-4686 R&D Projects: GA ČR GAP206/11/0727 Institutional support: RVO:61388955 Keywords : Fischer aminocarbene complexes biphasic electrolysis * EC-MS * HPLC-NMR Subject RIV: CG - Electrochemistry Impact factor: 4.803, year: 2015

27 CFR 28.223 - Export marks.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.223... Export marks. In addition to the marks and brands required to be placed on kegs, barrels, cases, crates... “Export” on each container or case before removal for export, for use on vessels or aircraft, or for...

High-throughput bone and cartilage micropellet manufacture, followed by assembly of micropellets into biphasic osteochondral tissue.

Science.gov (United States)

Babur, Betul Kul; Futrega, Kathryn; Lott, William B; Klein, Travis Jacob; Cooper-White, Justin; Doran, Michael Robert

2015-09-01

Engineered biphasic osteochondral tissues may have utility in cartilage defect repair. As bone-marrow-derived mesenchymal stem/stromal cells (MSC) have the capacity to make both bone-like and cartilage-like tissues, they are an ideal cell population for use in the manufacture of osteochondral tissues. Effective differentiation of MSC to bone-like and cartilage-like tissues requires two unique medium formulations and this presents a challenge both in achieving initial MSC differentiation and in maintaining tissue stability when the unified osteochondral tissue is subsequently cultured in a single medium formulation. In this proof-of-principle study, we used an in-house fabricated microwell platform to manufacture thousands of micropellets formed from 166 MSC each. We then characterized the development of bone-like and cartilage-like tissue formation in the micropellets maintained for 8-14 days in sequential combinations of osteogenic or chondrogenic induction medium. When bone-like or cartilage-like micropellets were induced for only 8 days, they displayed significant phenotypic changes when the osteogenic or chondrogenic induction medium, respectively, was swapped. Based on these data, we developed an extended 14-day protocol for the pre-culture of bone-like and cartilage-like micropellets in their respective induction medium. Unified osteochondral tissues were formed by layering 12,000 osteogenic micropellets and 12,000 chondrogenic micropellets into a biphasic structure and then further culture in chondrogenic induction medium. The assembled tissue was cultured for a further 8 days and characterized via histology. The micropellets had amalgamated into a continuous structure with distinctive bone-like and cartilage-like regions. This proof-of-concept study demonstrates the feasibility of micropellet assembly for the formation of osteochondral-like tissues for possible use in osteochondral defect repair.

The Design of Finite State Machine for Asynchronous Replication Protocol

Science.gov (United States)

Wang, Yanlong; Li, Zhanhuai; Lin, Wei; Hei, Minglei; Hao, Jianhua

Data replication is a key way to design a disaster tolerance system and to achieve reliability and availability. It is difficult for a replication protocol to deal with the diverse and complex environment. This means that data is less well replicated than it ought to be. To reduce data loss and to optimize replication protocols, we (1) present a finite state machine, (2) run it to manage an asynchronous replication protocol and (3) report a simple evaluation of the asynchronous replication protocol based on our state machine. It's proved that our state machine is applicable to guarantee the asynchronous replication protocol running in the proper state to the largest extent in the event of various possible events. It also can helpful to build up replication-based disaster tolerance systems to ensure the business continuity.

New biphasic solvent system based on cyclopentyl methyl ether for the purification of a non-polar synthetic peptide by pH-zone refining centrifugal partition chromatography.

Science.gov (United States)

Amarouche, Nassima; Boudesocque, Leslie; Borie, Nicolas; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, Florence; Renault, Jean-Hugues

2014-06-01

A new type 1 ternary biphasic system composed of cyclopentyl methyl ether, dimethylformamide and water was developed, characterized and successfully used for the purification of a lipophilic, protected peptide by pH-zone refining centrifugal partition chromatography. The protected peptide is an 8-mer, key intermediate in bivalirudin (Angiomax®) synthesis and shows a very low solubility in the solvents usually used in liquid chromatography. All ionic groups, except the N-terminal end of the peptide, are protected by a benzyl group. The purification of this peptide was achieved with a purity of about 99.04% and a recovery of 94% using the new ternary biphasic system cyclopentyl methyl ether/dimethylformamide/water (49:40:11, v/v) in the descending pH-zone refining mode with triethylamine (28 mM) as the retainer and methanesulfonic acid (18 mM) as the eluter. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Alleged Crisis and the Illusion of Exact Replication.

Science.gov (United States)

Stroebe, Wolfgang; Strack, Fritz

2014-01-01

There has been increasing criticism of the way psychologists conduct and analyze studies. These critiques as well as failures to replicate several high-profile studies have been used as justification to proclaim a "replication crisis" in psychology. Psychologists are encouraged to conduct more "exact" replications of published studies to assess the reproducibility of psychological research. This article argues that the alleged "crisis of replicability" is primarily due to an epistemological misunderstanding that emphasizes the phenomenon instead of its underlying mechanisms. As a consequence, a replicated phenomenon may not serve as a rigorous test of a theoretical hypothesis because identical operationalizations of variables in studies conducted at different times and with different subject populations might test different theoretical constructs. Therefore, we propose that for meaningful replications, attempts at reinstating the original circumstances are not sufficient. Instead, replicators must ascertain that conditions are realized that reflect the theoretical variable(s) manipulated (and/or measured) in the original study. © The Author(s) 2013.

Replicative bypass repair of ultraviolet damage to DNA of mammalian cells: caffeine sensitive and caffeine resistant mechanism

International Nuclear Information System (INIS)

Fujiwara, Y.; Tatsumi, M.

1976-01-01

Replicative bypass repair of UV damage to DNA was studied in a wide variaty of human, mouse and hamster cells in culture. Survival curve analysis revealed that in established cell lines (mouse L, Chinese hamster V79, HeLa S3 and SV40-transformed xeroderma pigmentosum (XP), post-UV caffeine treatment potentiated cell killing by reducing the extrapolation number and mean lethal UV fluence (Do). In the Do reduction as the result of random inactivation by caffeine of sensitive repair there were marked clonal differences among such cell lines, V79 being most sensitive to caffeine potentiation. However, other diploid cell lines (normal human, excision-defective XP and Syrian hamster) exhibited no obvious reduction in Do by caffeine. In parallel, alkaline sucrose sedimentation results showed that the conversion of initially smaller segments of DNA synthesized after irradiation with 10 J/m 2 to high-molecular-weight DNA was inhibited by caffeine in transformed XP cells, but not in the diploid human cell lines. Exceptionally, diploid XP variants had a retarded ability of bypass repair which was drastically prevented by caffeine, so that caffeine enhanced the lethal effect of UV. Neutral CsCl study on the bypass repair mechanism by use of bromodeoxyuridine for DNA synthesis on damaged template suggests that the pyrimodine dimer acts as a block to replication and subsequently it is circumvented presumably by a new process involving replicative bypassing following strand displacement, rather than by gap-filling de novo. This mechanism worked similarly in normal and XP cells, whether or not caffeine was present, indicating that excision of dimer is not always necessary. However, replicative bypassing became defective in XP variant and transformed XP cells when caffeine was present. It appears, therefore, that the replicative bypass repair process is either caffeine resistant or sensitive, depending on the cell type used, but not necessarily on the excision repair capability

DNA replication stress restricts ribosomal DNA copy number.

Science.gov (United States)

Salim, Devika; Bradford, William D; Freeland, Amy; Cady, Gillian; Wang, Jianmin; Pruitt, Steven C; Gerton, Jennifer L

2017-09-01

Ribosomal RNAs (rRNAs) in budding yeast are encoded by ~100-200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA) locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how "normal" copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2)-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a "normal" rDNA copy number.

DNA replication stress restricts ribosomal DNA copy number

Science.gov (United States)

Salim, Devika; Bradford, William D.; Freeland, Amy; Cady, Gillian; Wang, Jianmin

2017-01-01

Ribosomal RNAs (rRNAs) in budding yeast are encoded by ~100–200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA) locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how “normal” copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2)-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a “normal” rDNA copy number. PMID:28915237

DNA replication stress restricts ribosomal DNA copy number.

Directory of Open Access Journals (Sweden)

Devika Salim

2017-09-01

Full Text Available Ribosomal RNAs (rRNAs in budding yeast are encoded by ~100-200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how "normal" copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a "normal" rDNA copy number.

46 CFR 78.50-5 - Hull markings.

Science.gov (United States)

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Hull markings. 78.50-5 Section 78.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings on Vessels § 78.50-5 Hull markings. Vessels shall be marked as required by parts 67 and 69 of this chapter. [CGD 72...

46 CFR 196.40-5 - Hull markings.

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2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Hull markings. 196.40-5 Section 196.40-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings on Vessels § 196.40-5 Hull markings. Vessels shall be marked as required by parts 67 and 69 of this chapter...

46 CFR 97.40-5 - Hull markings.

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2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Hull markings. 97.40-5 Section 97.40-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings on Vessels § 97.40-5 Hull markings. Vessels shall be marked as required by parts 67 and 69 of this...

Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering

OpenAIRE

Mun-Hwan Lee; Changkook You; Kyo-Han Kim

2015-01-01

In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP) scaffolds. Surface characterization using a scanning electron microscope (SEM) and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell p...

Biphasically Modulating the Activity of Carboxypeptidase G2 with Ultrasound

Directory of Open Access Journals (Sweden)

Wanying Ma

2017-07-01

Full Text Available Background/Aims: Carboxypeptidase G2 (CPG2 has been used for cancer prodrug therapy to realize the targeted release of active drugs, but there yet lacks a means to modulate the CPG2 activity. Here ultrasound was used to modulate the CPG2 activity. Methods: The activity of insonated CPG2 was determined, and then underlying biochemical (i.e., monomer, dimer and conformation and ultrasonic (i.e., heat and cavitation mechanisms were explored. Results: Ultrasound (1.0 MHz increased or decreased the enzymatic activity; the activity decreased as zero- or first-order kinetics, depending on the intensity. L1 (10 W/cm2 for 200 s improved the activity via increasing the specific activity. L2 or L3 (20 W/cm2 for 1200 or 3000 s decreased the activity via disassembling the dimer, degrading the monomer, inducing glycosylation, transforming conformation and decreasing the specific activity. An increase or a slight decrease of activity attributable to 10 W/cm2 was reversible, but the activity decrease due to 20 W/cm2 was irreversible. The enzymatic modulation was realized via cavitation. Conclusion: Ultrasound can biphasically modulate the CPG2 activity, and can be employed in the CPG2-prodrug therapy to adjust the release and moles of active drugs.

Biphasic insulin aspart 30/70 (BIAsp 30 in the treatment of type 1 and type 2 diabetes

Directory of Open Access Journals (Sweden)

Paul Valensi

2009-06-01

Full Text Available Paul ValensiDepartment of Endocrinology-Diabetology-Nutrition, Jean Verdier Hospital, AP-HP, Paris Nord University, CRNH-IdF, Bondy, FranceAbstract: The pharmacological advantages of the rapid-acting analog, insulin aspart, over human insulin have contributed to the widespread prescription of the premix, biphasic insulin aspart 30/70 (BIAsp 30, in type 1 (T1DM and type 2 diabetes (T2DM. This article reviews the available literature on the pharmacology, efficacy and safety of BIAsp 30 in T1DM and T2DM from an online search of the PubMed database. Following injection, BIAsp 30 reaches higher plasma insulin levels more quickly than human premix or basal insulin, giving effective reduction of postprandial hyperglycemia. In T1DM patients, randomized controlled trials (RCTs have shown that HbA1c reduction is similar, but postprandial glycemic control is better, with BIAsp 30 than with human insulin regimens. In T2DM patients, lowering of HbA1c and postprandial hyperglycemia with BIAsp 30 compare favorably with optimized oral antidiabetes drug treatment, insulin glargine, and, in obese patients, human premix. An increase in minor hypoglycemia with BIAsp 30 relative to basal insulin has been reported in T2DM patients, but major and nocturnal hypoglycemia rates are generally low. Findings from RCTs in T2DM patients are supported by large observational studies. In summary, BIAsp 30 once to three times daily represents a simple and effective tool for the modern management of diabetes.Keywords: biphasic insulin aspart, BIAsp 30, premix, type 1 diabetes, type 2 diabetes

Biphase Cobalt-Manganese Oxide with High Capacity and Rate Performance for Aqueous Sodium-Ion Electrochemical Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Shan, Xiaoqiang [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering; Charles, Daniel S. [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering; Xu, Wenqian [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS). X-ray Science Division; Feygenson, Mikhail [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division and Spallation Neutron Source (SNS) outstation Juelich Centre for Neutron Science (JCNS), Forschungszentrum Juelich GmbH; Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN); Teng, Xiaowei [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering

2017-11-22

Manganese-based metal oxide electrode materials are of great importance in electrochemical energy storage for their favorable redox behavior, low cost and environmental-friendliness. However, their storage capacity and cycle life in aqueous Na-ion electrolytes is not satisfactory. In this paper, we report the development of a bi-phase cobalt-manganese oxide (Co-Mn-O) nanostructured electrode material, comprised of a layered MnO₂.H₂O birnessite phase and a (Co_0.83Mn_0.13Va_0.04)tetra(Co_0.38Mn_1.62)_octaO_3.72 (Va: vacancy; tetra: tetrahedral sites; octa: octahedral sites) spinel phase, verified by neutron total scattering and pair distribution function analyses. The bi-phase Co-Mn-O material demonstrates an excellent storage capacity towards Na-ions in an aqueous electrolyte (121 mA h g^-1 at a scan rate of 1 mV s^-1 in the half-cell and 81 mA h g^-1 at a current density of 2 A g^-1 after 5000 cycles in full-cells), as well as high rate performance (57 mA h g^-1 a rate of 360 C). Electro-kinetic analysis and in situ X-ray diffraction measurements further confirm that the synergistic interaction between the spinel and layered phases, as well as the vacancy of the tetrahedral sites of spinel phase, contribute to the improved capacity and rate performance of the Co-Mn-O material by facilitating both diffusion-limited redox and capacitive charge storage processes.

Chaotic interactions of self-replicating RNA.

Science.gov (United States)

Forst, C V

1996-03-01

A general system of high-order differential equations describing complex dynamics of replicating biomolecules is given. Symmetry relations and coordinate transformations of general replication systems leading to topologically equivalent systems are derived. Three chaotic attractors observed in Lotka-Volterra equations of dimension n = 3 are shown to represent three cross-sections of one and the same chaotic regime. Also a fractal torus in a generalized three-dimensional Lotka-Volterra Model has been linked to one of the chaotic attractors. The strange attractors are studied in the equivalent four-dimensional catalytic replicator network. The fractal torus has been examined in adapted Lotka-Volterra equations. Analytic expressions are derived for the Lyapunov exponents of the flow in the replicator system. Lyapunov spectra for different pathways into chaos has been calculated. In the generalized Lotka-Volterra system a second inner rest point--coexisting with (quasi)-periodic orbits--can be observed; with an abundance of different bifurcations. Pathways from chaotic tori, via quasi-periodic tori, via limit cycles, via multi-periodic orbits--emerging out of periodic doubling bifurcations--to "simple" chaotic attractors can be found.

Insights into the Initiation of Eukaryotic DNA Replication.

Science.gov (United States)

Bruck, Irina; Perez-Arnaiz, Patricia; Colbert, Max K; Kaplan, Daniel L

2015-01-01

The initiation of DNA replication is a highly regulated event in eukaryotic cells to ensure that the entire genome is copied once and only once during S phase. The primary target of cellular regulation of eukaryotic DNA replication initiation is the assembly and activation of the replication fork helicase, the 11-subunit assembly that unwinds DNA at a replication fork. The replication fork helicase, called CMG for Cdc45-Mcm2-7, and GINS, assembles in S phase from the constituent Cdc45, Mcm2-7, and GINS proteins. The assembly and activation of the CMG replication fork helicase during S phase is governed by 2 S-phase specific kinases, CDK and DDK. CDK stimulates the interaction between Sld2, Sld3, and Dpb11, 3 initiation factors that are each required for the initiation of DNA replication. DDK, on the other hand, phosphorylates the Mcm2, Mcm4, and Mcm6 subunits of the Mcm2-7 complex. Sld3 recruits Cdc45 to Mcm2-7 in a manner that depends on DDK, and recent work suggests that Sld3 binds directly to Mcm2-7 and also to single-stranded DNA. Furthermore, recent work demonstrates that Sld3 and its human homolog Treslin substantially stimulate DDK phosphorylation of Mcm2. These data suggest that the initiation factor Sld3/Treslin coordinates the assembly and activation of the eukaryotic replication fork helicase by recruiting Cdc45 to Mcm2-7, stimulating DDK phosphorylation of Mcm2, and binding directly to single-stranded DNA as the origin is melted.

Autonomous replication of plasmids bearing monkey DNA origin-enriched sequences

International Nuclear Information System (INIS)

Frappier, L.; Zannis-Hadjopoulos, M.

1987-01-01

Twelve clones of origin-enriched sequences (ORS) isolated from early replicating monkey (CV-1) DNA were examined for transient episomal replication in transfected CV-1, COS-7, and HeLa cells. Plasmid DNA was isolated at time intervals after transfection and screened by the Dpn I resistance assay or by the bromodeoxyuridine substitution assay to differentiate between input and replicated DNA. The authors have identified four monkey ORS (ORS3, -8, -9, and -12) that can support plasmid replication in mammalian cells. This replication is carried out in a controlled and semiconservative manner characteristic of mammalian replicons. ORS replication was most efficient in HeLa cells. Electron microscopy showed ORS8 and ORS12 plasmids of the correct size with replication bubbles. Using a unique restriction site in ORS12, we have mapped the replication bubble within the monkey DNA sequence

Materials Chemistry and Performance of Silicone-Based Replicating Compounds.

Energy Technology Data Exchange (ETDEWEB)

Brumbach, Michael T.; Mirabal, Alex James; Kalan, Michael; Trujillo, Ana B; Hale, Kevin

2014-11-01

Replicating compounds are used to cast reproductions of surface features on a variety of materials. Replicas allow for quantitative measurements and recordkeeping on parts that may otherwise be difficult to measure or maintain. In this study, the chemistry and replicating capability of several replicating compounds was investigated. Additionally, the residue remaining on material surfaces upon removal of replicas was quantified. Cleaning practices were tested for several different replicating compounds. For all replicating compounds investigated, a thin silicone residue was left by the replica. For some compounds, additional inorganic species could be identified in the residue. Simple solvent cleaning could remove some residue.

Bayesian tests to quantify the result of a replication attempt

NARCIS (Netherlands)

Verhagen, J.; Wagenmakers, E.-J.

2014-01-01

Replication attempts are essential to the empirical sciences. Successful replication attempts increase researchers’ confidence in the presence of an effect, whereas failed replication attempts induce skepticism and doubt. However, it is often unclear to what extent a replication attempt results in

Spatio-temporal re-organization of replication foci accompanies replication domain consolidation during human pluripotent stem cell lineage specification

Science.gov (United States)

Wilson, Korey A.; Elefanty, Andrew G.; Stanley, Edouard G.; Gilbert, David M.

2016-01-01

ABSTRACT Lineage specification of both mouse and human pluripotent stem cells (PSCs) is accompanied by spatial consolidation of chromosome domains and temporal consolidation of their replication timing. Replication timing and chromatin organization are both established during G1 phase at the timing decision point (TDP). Here, we have developed live cell imaging tools to track spatio-temporal replication domain consolidation during differentiation. First, we demonstrate that the fluorescence ubiquitination cell cycle indicator (Fucci) system is incapable of demarcating G1/S or G2/M cell cycle transitions. Instead, we employ a combination of fluorescent PCNA to monitor S phase progression, cytokinesis to demarcate mitosis, and fluorescent nucleotides to label early and late replication foci and track their 3D organization into sub-nuclear chromatin compartments throughout all cell cycle transitions. We find that, as human PSCs differentiate, the length of S phase devoted to replication of spatially clustered replication foci increases, coincident with global compartmentalization of domains into temporally clustered blocks of chromatin. Importantly, re-localization and anchorage of domains was completed prior to the onset of S phase, even in the context of an abbreviated PSC G1 phase. This approach can also be employed to investigate cell fate transitions in single PSCs, which could be seen to differentiate preferentially from G1 phase. Together, our results establish real-time, live-cell imaging methods for tracking cell cycle transitions during human PSC differentiation that can be applied to study chromosome domain consolidation and other aspects of lineage specification. PMID:27433885

A Molecular Toolbox to Engineer Site-Specific DNA Replication Perturbation.

Science.gov (United States)

Larsen, Nicolai B; Hickson, Ian D; Mankouri, Hocine W

2018-01-01

Site-specific arrest of DNA replication is a useful tool for analyzing cellular responses to DNA replication perturbation. The E. coli Tus-Ter replication barrier can be reconstituted in eukaryotic cells as a system to engineer an unscheduled collision between a replication fork and an "alien" impediment to DNA replication. To further develop this system as a versatile tool, we describe a set of reagents and a detailed protocol that can be used to engineer Tus-Ter barriers into any locus in the budding yeast genome. Because the Tus-Ter complex is a bipartite system with intrinsic DNA replication-blocking activity, the reagents and protocols developed and validated in yeast could also be optimized to engineer site-specific replication fork barriers into other eukaryotic cell types.

A Molecular Toolbox to Engineer Site-Specific DNA Replication Perturbation

DEFF Research Database (Denmark)

Larsen, Nicolai B; Hickson, Ian D; Mankouri, Hocine W

2018-01-01

" impediment to DNA replication. To further develop this system as a versatile tool, we describe a set of reagents and a detailed protocol that can be used to engineer Tus-Ter barriers into any locus in the budding yeast genome. Because the Tus-Ter complex is a bipartite system with intrinsic DNA replication......Site-specific arrest of DNA replication is a useful tool for analyzing cellular responses to DNA replication perturbation. The E. coli Tus-Ter replication barrier can be reconstituted in eukaryotic cells as a system to engineer an unscheduled collision between a replication fork and an "alien......-blocking activity, the reagents and protocols developed and validated in yeast could also be optimized to engineer site-specific replication fork barriers into other eukaryotic cell types....

Structural properties of replication origins in yeast DNA sequences

International Nuclear Information System (INIS)

Cao Xiaoqin; Zeng Jia; Yan Hong

2008-01-01

Sequence-dependent DNA flexibility is an important structural property originating from the DNA 3D structure. In this paper, we investigate the DNA flexibility of the budding yeast (S. Cerevisiae) replication origins on a genome-wide scale using flexibility parameters from two different models, the trinucleotide and the tetranucleotide models. Based on analyzing average flexibility profiles of 270 replication origins, we find that yeast replication origins are significantly rigid compared with their surrounding genomic regions. To further understand the highly distinctive property of replication origins, we compare the flexibility patterns between yeast replication origins and promoters, and find that they both contain significantly rigid DNAs. Our results suggest that DNA flexibility is an important factor that helps proteins recognize and bind the target sites in order to initiate DNA replication. Inspired by the role of the rigid region in promoters, we speculate that the rigid replication origins may facilitate binding of proteins, including the origin recognition complex (ORC), Cdc6, Cdt1 and the MCM2-7 complex

Mark II magnetic detector for SPEAR

International Nuclear Information System (INIS)

Larsen, R.R.

1975-01-01

The Mark II Detector, presently in the design stage, is a SLAC/LBL detector project to replace the Mark I now in operation at SPEAR. While similar in concept to the Mark I it will have improved momentum resolution, shower detection, solid angle coverage for both triggering and tracking and a magnet design providing easier access to those particles transmitted through the aluminum coil

Mark Napier / Mark Napier ; interv. Tilman Baumgärtel

Index Scriptorium Estoniae

Napier, Mark

2006-01-01

Ameerika kunstnikust Mark Napierist (sünd. 1961) ja tema loomingust, 2001. a. tehtud meiliintervjuu kunstnikuga. Võrguteosest "The Digital Landfill" (1998), koos Andy Deckiga loodud tööst "GrafficJam" (1999), töödest "Shredder" (1998), "Feed", "Riot", "P-Soup" (2000), võrgukunstist ja muust

From structure to mechanism—understanding initiation of DNA replication

Science.gov (United States)

Riera, Alberto; Barbon, Marta; Noguchi, Yasunori; Reuter, L. Maximilian; Schneider, Sarah; Speck, Christian

2017-01-01

DNA replication results in the doubling of the genome prior to cell division. This process requires the assembly of 50 or more protein factors into a replication fork. Here, we review recent structural and biochemical insights that start to explain how specific proteins recognize DNA replication origins, load the replicative helicase on DNA, unwind DNA, synthesize new DNA strands, and reassemble chromatin. We focus on the minichromosome maintenance (MCM2–7) proteins, which form the core of the eukaryotic replication fork, as this complex undergoes major structural rearrangements in order to engage with DNA, regulate its DNA-unwinding activity, and maintain genome stability. PMID:28717046

MYC and the Control of DNA Replication

Science.gov (United States)

Dominguez-Sola, David; Gautier, Jean

2014-01-01

The MYC oncogene is a multifunctional protein that is aberrantly expressed in a significant fraction of tumors from diverse tissue origins. Because of its multifunctional nature, it has been difficult to delineate the exact contributions of MYC’s diverse roles to tumorigenesis. Here, we review the normal role of MYC in regulating DNA replication as well as its ability to generate DNA replication stress when overexpressed. Finally, we discuss the possible mechanisms by which replication stress induced by aberrant MYC expression could contribute to genomic instability and cancer. PMID:24890833

Organization of Replication of Ribosomal DNA in Saccharomyces cerevisiae

NARCIS (Netherlands)

Linskens, Maarten H.K.; Huberman, Joel A.

1988-01-01

Using recently developed replicon mapping techniques, we have analyzed the replication of the ribosomal DNA in Saccharomyces cerevisiae. The results show that (i) the functional origin of replication colocalizes with an autonomously replicating sequence element previously mapped to the

Cyclophilin B facilitates the replication of Orf virus.

Science.gov (United States)

Zhao, Kui; Li, Jida; He, Wenqi; Song, Deguang; Zhang, Ximu; Zhang, Di; Zhou, Yanlong; Gao, Feng

2017-06-15

Viruses interact with host cellular factors to construct a more favourable environment for their efficient replication. Expression of cyclophilin B (CypB), a cellular peptidyl-prolyl cis-trans isomerase (PPIase), was found to be significantly up-regulated. Recently, a number of studies have shown that CypB is important in the replication of several viruses, including Japanese encephalitis virus (JEV), hepatitis C virus (HCV) and human papillomavirus type 16 (HPV 16). However, the function of cellular CypB in ORFV replication has not yet been explored. Suppression subtractive hybridization (SSH) technique was applied to identify genes differentially expressed in the ORFV-infected MDBK cells at an early phase of infection. Cellular CypB was confirmed to be significantly up-regulated by quantitative reverse transcription-PCR (qRT-PCR) analysis and Western blotting. The role of CypB in ORFV infection was further determined using Cyclosporin A (CsA) and RNA interference (RNAi). Effect of CypB gene silencing on ORFV replication by 50% tissue culture infectious dose (TCID 50 ) assay and qRT-PCR detection. In the present study, CypB was found to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection. Cyclosporin A (CsA) exhibited suppressive effects on ORFV replication through the inhibition of CypB. Silencing of CypB gene inhibited the replication of ORFV in MDBK cells. In conclusion, these data suggest that CypB is critical for the efficient replication of the ORFV genome. Cellular CypB was confirmed to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection, which could effectively facilitate the replication of ORFV.

Design and evaluation of lornoxicam bilayered tablets for biphasic release

Directory of Open Access Journals (Sweden)

Songa Ambedkar Sunil

2012-12-01

Full Text Available The objective of the present investigation was to develop bilayered tablets of lornoxicam to achieve biphasic release pattern. A bilayered tablet, consisting of an immediate and controlled release layer, was prepared by direct compression technique. The controlled release effect was achieved by using various hydrophilic natural, semi synthetic and synthetic controlled release polymers such as xanthan gum, hydroxypropyl methylcellulose (HPMC and polyethylene oxide (PEO to modulate the release of the drug. The in vitro drug release profiles showed the biphasic release behavior in which the immediate release (IR layer containing the lornoxicam was released within 15 minutes, whereas the controlled release (CR layer controlled the drug release for up to 24 h. All the bilayered tablets formulated have followed the zero order release with non-Fickian diffusion controlled release mechanism after the initial burst release. FTIR studies revealed that there was no interaction between the drug and polymers used in the study. Statistical analysis (ANOVA showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p O objetivo do presente trabalho foi desenvolver comprimidos bicamada de lornoxicam para atingir padrão de liberação bifásica. Preparou-se, por compressão direta, comprimido bicamada, consistindo de uma camada de liberação imediata e uma de liberação controlada. A liberação controlada foi obtida pelo uso de vários polímeros naturais hidrofílicos, semi-sintéticos e sintéticos, tais como goma xantana, hidroxipropilmetil celulose (HPMC e óxido de polietileno (PEO para modular a liberação do fármaco. Os perfis de liberação in vitro mostraram comportamento bifásico em que a camada de liberação imediata (IR contendo lornoxicam foi liberada em 15 minutos, enquanto a camada de liberação controlada (CR liberou o fármaco em mais de 24 horas, Todos os comprimidos bicamada

Influence of microstructure on low cycle fatigue in some single phase and biphasic stainless steels

Energy Technology Data Exchange (ETDEWEB)

Stolarz, J. [Ecole Nationale Superieure des Mines, Centre SMS, URA CNRS 1884, Saint-Etienne (France)

2004-07-01

This overview deals with the effects of microstructural parameters in different single phase and biphasic stainless steels on short crack behaviour and on fatigue life in the low cycle regime. The effect of the grain size is investigated in a single phase austenitic stainless steel. Under plastic strain control, the fatigue life increases when the grain size decreases. The results are discussed by analysing the distributions of crack depths as a function of the grain size. The second type of material is a metastable austenitic steel which partially transforms into martensite during LCF at temperatures between -50 C and +120 C. The grain size of the initially single phase austenitic microstructure has a combined influence on the volume fraction of martensite produced during fatigue and on the fatigue life. In this case, the grain size effect is still considerable but totally indirect because all fatigue cracks grow exclusively in the martensite. The cyclic behaviour analysis in biphasic alloys in which two phases undergo plastic deformation during LCF is considerably more complex because the conventional concept of microstructural barriers cannot be applied. The possible damage patterns in a pair of grains with different mechanical properties are discussed on the example of a solution treated and aged superduplex austenitic-ferritic stainless steel (SDSS). The hardening of one phase (ferrite) through ageing at 475 C changes the cyclic behaviour of the initial ''quasi single phase'' microstructure. Consequently, the fatigue life under plastic strain control decreases compared with the solution treated SDSS. The discussion is focussed on LCF damage mechanisms at the microstructure size scale with a particular accent put on the propagation of short cracks in the bulk. All the microstructures exhibit some common features with respect to the behaviour of short cracks. In particular a strong effect of microstructural barriers in the bulk and the

Autophagy Facilitates Salmonella Replication in HeLa Cells

Science.gov (United States)

Yu, Hong B.; Croxen, Matthew A.; Marchiando, Amanda M.; Ferreira, Rosana B. R.; Cadwell, Ken; Foster, Leonard J.; Finlay, B. Brett

2014-01-01

ABSTRACT Autophagy is a process whereby a double-membrane structure (autophagosome) engulfs unnecessary cytosolic proteins, organelles, and invading pathogens and delivers them to the lysosome for degradation. We examined the fate of cytosolic Salmonella targeted by autophagy and found that autophagy-targeted Salmonella present in the cytosol of HeLa cells correlates with intracellular bacterial replication. Real-time analyses revealed that a subset of cytosolic Salmonella extensively associates with autophagy components p62 and/or LC3 and replicates quickly, whereas intravacuolar Salmonella shows no or very limited association with p62 or LC3 and replicates much more slowly. Replication of cytosolic Salmonella in HeLa cells is significantly decreased when autophagy components are depleted. Eventually, hyperreplication of cytosolic Salmonella potentiates cell detachment, facilitating the dissemination of Salmonella to neighboring cells. We propose that Salmonella benefits from autophagy for its cytosolic replication in HeLa cells. PMID:24618251

Study on biphasic material model and mechanical analysis of knee joint cartilage

Energy Technology Data Exchange (ETDEWEB)

Nakatani, A; Sakashita, A [Department of Adaptive Machine Systems, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: nakatani@ams.eng.osaka-u.ac.jp

2008-02-15

A material model of articular cartilage is formulated, and fundamental problems are analyzed. The soft tissue is assumed to comprise two phases: solid and fluid. The biphasic theory proposed by Spilker and Suh (1990) to deal with such materials is reviewed, and some new additional analyses are carried out on the basis of this theory. Assuming the elasticity for the solid phase and introducing the pressure, which is defined by the product of the volume change and penalty coefficient, it is shown that the viscoelastic property of the soft tissue can be reproduced. A preferable solution is obtained for the solid phase by using the reduction integral, even if a high-order interpolation function is used. However, the high-order element cannot satisfactorily capture the velocity distribution of fluids. The pressure distribution is studied by assuming the change in the surface characteristics of the cartilage tissue with the progress of osteoarthritis. The pressure is strongly related to the lubrication conditions, i.e., perfect lubrication, perfect adhesion, and partial adhesion.

A multicenter prospective randomized study comparing the efficacy of escalating higher biphasic versus low biphasic energy defibrillations in patients presenting with cardiac arrest in the in-hospital environment

Directory of Open Access Journals (Sweden)

Anantharaman V

2017-01-01

Full Text Available Venkataraman Anantharaman,1 Seow Yian Tay,2 Peter George Manning,3 Swee Han Lim,1 Terrance Siang Jin Chua,4 Mohan Tiru,5 Rabind Antony Charles,1 Vidya Sudarshan1 1Department of Emergency Medicine, Singapore General Hospital, 2Department of Emergency Medicine, Tan Tock Seng Hospital, 3Emergency Medicine Department, National University Hospital, 4Department of Cardiology, National Heart Centre, 5Accident and Emergency Department, Changi General Hospital, Singapore Background: Biphasic defibrillation has been practiced worldwide for >15 years. Yet, consensus does not exist on the best energy levels for optimal outcomes when used in patients with ventricular fibrillation (VF/pulseless ventricular tachycardia (VT.Methods: This prospective, randomized, controlled trial of 235 adult cardiac arrest patients with VF/VT was conducted in the emergency and cardiology departments. One group received low-energy (LE shocks at 150–150–150 J and the other escalating higher-energy (HE shocks at 200–300–360 J. If return of spontaneous circulation (ROSC was not achieved by the third shock, LE patients crossed over to the HE arm and HE patients continued at 360 J. Primary end point was ROSC. Secondary end points were 24-hour, 7-day, and 30-day survival.Results: Both groups were comparable for age, sex, cardiac risk factors, and duration of collapse and VF/VT. Of the 118 patients randomized to the LE group, 48 crossed over to the HE protocol, 24 for persistent VF, and 24 for recurrent VF. First-shock termination rates for HE and LE patients were 66.67% and 64.41%, respectively (P=0.78, confidence interval: 0.65–1.89. First-shock ROSC rates were 25.64% and 29.66%, respectively (P=0.56, confidence interval: 0.46–1.45. The 24-hour, 7-day, and 30-day survival rates were 85.71%, 74.29%, and 62.86% for first-shock ROSC LE patients and 70.00%, 50.00%, and 46.67% for first-shock ROSC HE patients, respectively. Conversion rates for further shocks at 200 J and

Stabilization of Reversed Replication Forks by Telomerase Drives Telomere Catastrophe.

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Margalef, Pol; Kotsantis, Panagiotis; Borel, Valerie; Bellelli, Roberto; Panier, Stephanie; Boulton, Simon J

2018-01-25

Telomere maintenance critically depends on the distinct activities of telomerase, which adds telomeric repeats to solve the end replication problem, and RTEL1, which dismantles DNA secondary structures at telomeres to facilitate replisome progression. Here, we establish that reversed replication forks are a pathological substrate for telomerase and the source of telomere catastrophe in Rtel1 -/- cells. Inhibiting telomerase recruitment to telomeres, but not its activity, or blocking replication fork reversal through PARP1 inhibition or depleting UBC13 or ZRANB3 prevents the rapid accumulation of dysfunctional telomeres in RTEL1-deficient cells. In this context, we establish that telomerase binding to reversed replication forks inhibits telomere replication, which can be mimicked by preventing replication fork restart through depletion of RECQ1 or PARG. Our results lead us to propose that telomerase inappropriately binds to and inhibits restart of reversed replication forks within telomeres, which compromises replication and leads to critically short telomeres. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Chronic DNA Replication Stress Reduces Replicative Lifespan of Cells by TRP53-Dependent, microRNA-Assisted MCM2-7 Downregulation.

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Gongshi Bai

2016-01-01

Full Text Available Circumstances that compromise efficient DNA replication, such as disruptions to replication fork progression, cause a state known as DNA replication stress (RS. Whereas normally proliferating cells experience low levels of RS, excessive RS from intrinsic or extrinsic sources can trigger cell cycle arrest and senescence. Here, we report that a key driver of RS-induced senescence is active downregulation of the Minichromosome Maintenance 2-7 (MCM2-7 factors that are essential for replication origin licensing and which constitute the replicative helicase core. Proliferating cells produce high levels of MCM2-7 that enable formation of dormant origins that can be activated in response to acute, experimentally-induced RS. However, little is known about how physiological RS levels impact MCM2-7 regulation. We found that chronic exposure of primary mouse embryonic fibroblasts (MEFs to either genetically-encoded or environmentally-induced RS triggered gradual MCM2-7 repression, followed by inhibition of replication and senescence that could be accelerated by MCM hemizygosity. The MCM2-7 reduction in response to RS is TRP53-dependent, and involves a group of Trp53-dependent miRNAs, including the miR-34 family, that repress MCM expression in replication-stressed cells before they undergo terminal cell cycle arrest. miR-34 ablation partially rescued MCM2-7 downregulation and genomic instability in mice with endogenous RS. Together, these data demonstrate that active MCM2-7 repression is a physiologically important mechanism for RS-induced cell cycle arrest and genome maintenance on an organismal level.

Hepatitis C Virus Replication Depends on Endosomal Cholesterol Homeostasis.

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Stoeck, Ina Karen; Lee, Ji-Young; Tabata, Keisuke; Romero-Brey, Inés; Paul, David; Schult, Philipp; Lohmann, Volker; Kaderali, Lars; Bartenschlager, Ralf

2018-01-01

Similar to other positive-strand RNA viruses, hepatitis C virus (HCV) causes massive rearrangements of intracellular membranes, resulting in a membranous web (MW) composed of predominantly double-membrane vesicles (DMVs), the presumed sites of RNA replication. DMVs are enriched for cholesterol, but mechanistic details on the source and recruitment of cholesterol to the viral replication organelle are only partially known. Here we focused on selected lipid transfer proteins implicated in direct lipid transfer at various endoplasmic reticulum (ER)-membrane contact sites. RNA interference (RNAi)-mediated knockdown identified several hitherto unknown HCV dependency factors, such as steroidogenic acute regulatory protein-related lipid transfer domain protein 3 (STARD3), oxysterol-binding protein-related protein 1A and -B (OSBPL1A and -B), and Niemann-Pick-type C1 (NPC1), all residing at late endosome and lysosome membranes and required for efficient HCV RNA replication but not for replication of the closely related dengue virus. Focusing on NPC1, we found that knockdown or pharmacological inhibition caused cholesterol entrapment in lysosomal vesicles concomitant with decreased cholesterol abundance at sites containing the viral replicase factor NS5A. In untreated HCV-infected cells, unesterified cholesterol accumulated at the perinuclear region, partially colocalizing with NS5A at DMVs, arguing for NPC1-mediated endosomal cholesterol transport to the viral replication organelle. Consistent with cholesterol being an important structural component of DMVs, reducing NPC1-dependent endosomal cholesterol transport impaired MW integrity. This suggests that HCV usurps lipid transfer proteins, such as NPC1, at ER-late endosome/lysosome membrane contact sites to recruit cholesterol to the viral replication organelle, where it contributes to MW functionality. IMPORTANCE A key feature of the replication of positive-strand RNA viruses is the rearrangement of the host cell

Geminin: a major DNA replication safeguard in higher eukaryotes

DEFF Research Database (Denmark)

Melixetian, Marina; Helin, Kristian

2004-01-01

Eukaryotes have evolved multiple mechanisms to restrict DNA replication to once per cell cycle. These mechanisms prevent relicensing of origins of replication after initiation of DNA replication in S phase until the end of mitosis. Most of our knowledge of mechanisms controlling prereplication...

Biphasic Rapamycin Effects in Lymphoma and Carcinoma Treatment.

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Liu, Yang; Pandeswara, Srilakshmi; Dao, Vinh; Padrón, Álvaro; Drerup, Justin M; Lao, Shunhua; Liu, Aijie; Hurez, Vincent; Curiel, Tyler J

2017-01-15

mTOR drives tumor growth but also supports T-cell function, rendering the applications of mTOR inhibitors complex especially in T-cell malignancies. Here, we studied the effects of the mTOR inhibitor rapamycin in mouse EL4 T-cell lymphoma. Typical pharmacologic rapamycin (1-8 mg/kg) significantly reduced tumor burden via direct suppression of tumor cell proliferation and improved survival in EL4 challenge independent of antitumor immunity. Denileukin diftitox (DD)-mediated depletion of regulatory T cells significantly slowed EL4 growth in vivo in a T-cell-dependent fashion. However, typical rapamycin inhibited T-cell activation and tumor infiltration in vivo and failed to boost DD treatment effects. Low-dose (LD) rapamycin (75 μg/kg) increased potentially beneficial CD44hiCD62L + CD8 + central memory T cells in EL4 challenge, but without clinical benefit. LD rapamycin significantly enhanced DD treatment efficacy, but DD plus LD rapamycin treatment effects were independent of antitumor immunity. Instead, rapamycin upregulated EL4 IL2 receptor in vitro and in vivo, facilitating direct DD tumor cell killing. LD rapamycin augmented DD efficacy against B16 melanoma and a human B-cell lymphoma, but not against human Jurkat T-cell lymphoma or ID8agg ovarian cancer cells. Treatment effects correlated with IL2R expression, but mechanisms in some tumors were not fully defined. Overall, our data define a distinct, biphasic mechanisms of action of mTOR inhibition at doses that are clinically exploitable, including in T-cell lymphomas. Cancer Res; 77(2); 520-31. ©2016 AACR. ©2016 American Association for Cancer Research.

Optical tweezers reveal how proteins alter replication

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Chaurasiya, Kathy

Single molecule force spectroscopy is a powerful method that explores the DNA interaction properties of proteins involved in a wide range of fundamental biological processes such as DNA replication, transcription, and repair. We use optical tweezers to capture and stretch a single DNA molecule in the presence of proteins that bind DNA and alter its mechanical properties. We quantitatively characterize the DNA binding mechanisms of proteins in order to provide a detailed understanding of their function. In this work, we focus on proteins involved in replication of Escherichia coli (E. coli ), endogenous eukaryotic retrotransposons Ty3 and LINE-1, and human immunodeficiency virus (HIV). DNA polymerases replicate the entire genome of the cell, and bind both double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) during DNA replication. The replicative DNA polymerase in the widely-studied model system E. coli is the DNA polymerase III subunit alpha (DNA pol III alpha). We use optical tweezers to determine that UmuD, a protein that regulates bacterial mutagenesis through its interactions with DNA polymerases, specifically disrupts alpha binding to ssDNA. This suggests that UmuD removes alpha from its ssDNA template to allow DNA repair proteins access to the damaged DNA, and to facilitate exchange of the replicative polymerase for an error-prone translesion synthesis (TLS) polymerase that inserts nucleotides opposite the lesions, so that bacterial DNA replication may proceed. This work demonstrates a biophysical mechanism by which E. coli cells tolerate DNA damage. Retroviruses and retrotransposons reproduce by copying their RNA genome into the nuclear DNA of their eukaryotic hosts. Retroelements encode proteins called nucleic acid chaperones, which rearrange nucleic acid secondary structure and are therefore required for successful replication. The chaperone activity of these proteins requires strong binding affinity for both single- and double-stranded nucleic

From structure to mechanism-understanding initiation of DNA replication.

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Riera, Alberto; Barbon, Marta; Noguchi, Yasunori; Reuter, L Maximilian; Schneider, Sarah; Speck, Christian

2017-06-01

DNA replication results in the doubling of the genome prior to cell division. This process requires the assembly of 50 or more protein factors into a replication fork. Here, we review recent structural and biochemical insights that start to explain how specific proteins recognize DNA replication origins, load the replicative helicase on DNA, unwind DNA, synthesize new DNA strands, and reassemble chromatin. We focus on the minichromosome maintenance (MCM2-7) proteins, which form the core of the eukaryotic replication fork, as this complex undergoes major structural rearrangements in order to engage with DNA, regulate its DNA-unwinding activity, and maintain genome stability. © 2017 Riera et al.; Published by Cold Spring Harbor Laboratory Press.

Murine leukemia virus (MLV replication monitored with fluorescent proteins

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Bittner Alexandra

2004-12-01

Full Text Available Abstract Background Cancer gene therapy will benefit from vectors that are able to replicate in tumor tissue and cause a bystander effect. Replication-competent murine leukemia virus (MLV has been described to have potential as cancer therapeutics, however, MLV infection does not cause a cytopathic effect in the infected cell and viral replication can only be studied by immunostaining or measurement of reverse transcriptase activity. Results We inserted the coding sequences for green fluorescent protein (GFP into the proline-rich region (PRR of the ecotropic envelope protein (Env and were able to fluorescently label MLV. This allowed us to directly monitor viral replication and attachment to target cells by flow cytometry. We used this method to study viral replication of recombinant MLVs and split viral genomes, which were generated by replacement of the MLV env gene with the red fluorescent protein (RFP and separately cloning GFP-Env into a retroviral vector. Co-transfection of both plasmids into target cells resulted in the generation of semi-replicative vectors, and the two color labeling allowed to determine the distribution of the individual genomes in the target cells and was indicative for the occurrence of recombination events. Conclusions Fluorescently labeled MLVs are excellent tools for the study of factors that influence viral replication and can be used to optimize MLV-based replication-competent viruses or vectors for gene therapy.

Response of sublethally irradiated monkeys to a replicating viral antigen

International Nuclear Information System (INIS)

Hilmas, D.E.; Spertzel, R.O.

1975-01-01

Temporal effects of exposure to sublethal, total-body x radiation (400 R) on responses to vaccination with the attenuated Venezuelan equine encephalomyelitis vaccine virus, TC-83, were examined in rhesus monkeys. Viremia, often with delayed onset, was prolonged even when irradiation preceded vaccination by 28 days. Virus titers were increased, particularly in groups irradiated 4 or 7 days before vaccination. Delay in appearance of hemagglutination-inhibition and serum-neutralizing antibody correlated closely with persistence of viremia in irradiated-vaccinated monkeys. The temporal course of antibody response was markedly affected by the interval between irradiation and injection of this replicating antigen. With longer intervals between irradiation and vaccination, the somewhat depressed antibody responses approached normal or surpassed those of nonirradiated monkeys. Vaccination 14 days after radiation exposure resulted in lethality to 8 of 12 monkeys, apparently as a result of secondary infection. The additional lymphopenic stress due to the effect of TC-83, superimposed on the severely depressed hematopoietic competence at 14 days, undoubtedly contributed to this increased susceptibility to latent infection

Cytoplasmic ATR Activation Promotes Vaccinia Virus Genome Replication

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Antonio Postigo

2017-05-01

Full Text Available In contrast to most DNA viruses, poxviruses replicate their genomes in the cytoplasm without host involvement. We find that vaccinia virus induces cytoplasmic activation of ATR early during infection, before genome uncoating, which is unexpected because ATR plays a fundamental nuclear role in maintaining host genome integrity. ATR, RPA, INTS7, and Chk1 are recruited to cytoplasmic DNA viral factories, suggesting canonical ATR pathway activation. Consistent with this, pharmacological and RNAi-mediated inhibition of canonical ATR signaling suppresses genome replication. RPA and the sliding clamp PCNA interact with the viral polymerase E9 and are required for DNA replication. Moreover, the ATR activator TOPBP1 promotes genome replication and associates with the viral replisome component H5. Our study suggests that, in contrast to long-held beliefs, vaccinia recruits conserved components of the eukaryote DNA replication and repair machinery to amplify its genome in the host cytoplasm.

Responses of female rock lizards to multiple scent marks of males: effects of male age, male density and scent over-marking.

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Martín, José; López, Pilar

2013-03-01

Scent-marked substrates may inform conspecifics on the characteristics of territorial males. Scent-marks of male Carpetan rock lizards (Iberolacerta cyreni) affect space use of females, which by selecting an area may increase the probability of mating with the male that has scent-marked that area. However, males do not hold exclusive territories, and scent-marks of different individual males are often together. This may provide complex information from multiple sources on the social structure. Here, we examined female preference in response to scent marks of various males and combinations in a laboratory experiment. Females preferred areas scent-marked by territorial old males against those scent-marked by young satellite-sneaker males. This reflected the known preference of females for mating with old males. In a second experiment, females preferred areas scent-marked by two males to areas of similar size marked by a single male. This may increase the probability of obtaining multiple copulations with different males, which may favour sperm competition and cryptic female choice, or may be a way to avoid infertile males. Finally, when we experimentally over-marked the scent-marks of an old male with scent-marks of a young male, females did not avoid, nor prefer, the over-marked area, suggesting that the quality of the old male may override the presence of a satellite male. We suggest that, irrespective of the causes underlying why a female selects a scent-marked area, this strategy may affect her reproductive success, which may have the same evolutionary consequences that "direct" mate choice decisions of other animals. Copyright © 2013 Elsevier B.V. All rights reserved.

A histomorphometric and micro-computed tomography study of bone regeneration in the maxillary sinus comparing biphasic calcium phosphate and deproteinized cancellous bovine bone in a human split-mouth model

NARCIS (Netherlands)

de Lange, G.L.; Overman, J.R.; Farre-Guasch, E.; Korstjens, C.M.; Hartman, B.; Langenbach, G.E.J.; van Duin, M.A.; Klein-Nulend, J.

2014-01-01

Objective The gain of mineralized bone was compared between deproteinized bovine bone allograft (DBA) and biphasic calcium phosphate (BCP) for dental implant placement. Study Design Five patients with atrophic maxillae underwent bilateral sinus elevation with DBA (Bio-Oss) and BCP (Straumann

The DNA Replication Stress Hypothesis of Alzheimer’s Disease

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Yuri B. Yurov

2011-01-01

Full Text Available A well-recognized theory of Alzheimer’s disease (AD pathogenesis suggests ectopic cell cycle events to mediate neurodegeneration. Vulnerable neurons of the AD brain exhibit biomarkers of cell cycle progression and DNA replication suggesting a reentry into the cell cycle. Chromosome reduplication without proper cell cycle completion and mitotic division probably causes neuronal cell dysfunction and death. However, this theory seems to require some inputs in accordance with the generally recognized amyloid cascade theory as well as to explain causes and consequences of genomic instability (aneuploidy in the AD brain. We propose that unscheduled and incomplete DNA replication (replication stress destabilizes (epigenomic landscape in the brain and leads to DNA replication “catastrophe” causing cell death during the S phase (replicative cell death. DNA replication stress can be a key element of the pathogenetic cascade explaining the interplay between ectopic cell cycle events and genetic instabilities in the AD brain. Abnormal cell cycle reentry and somatic genome variations can be used for updating the cell cycle theory introducing replication stress as a missing link between cell genetics and neurobiology of AD.

Percentage Retail Mark-Ups

OpenAIRE

Thomas von Ungern-Sternberg

1999-01-01

A common assumption in the literature on the double marginalization problem is that the retailer can set his mark-up only in the second stage of the game after the producer has moved. To the extent that the sequence of moves is designed to reflect the relative bargaining power of the two parties it is just as plausible to let the retailer move first. Furthermore, retailers frequently calculate their selling prices by adding a percentage mark-up to their wholesale prices. This allows a retaile...

Laser marking method and device

International Nuclear Information System (INIS)

Okazaki, Yuki; Aoki, Nobutada; Mukai, Narihiko; Sano, Yuji; Yamamoto, Seiji.

1997-01-01

An object is disposed in laser beam permeating liquid or gaseous medium. Laser beams such as CW laser or pulse laser oscillated from a laser device are emitted to the object to apply laser markings with less degradation of identification and excellent corrosion resistance on the surface of the object simply and easily. Upon applying the laser markings, a liquid or gas as a laser beam permeating medium is blown onto the surface of the object, or the liquid or gas in the vicinity of the object is sucked, the laser beam-irradiated portion on the surface can be cooled positively. Accordingly, the laser marking can be formed on the surface of the object with less heat affection to the object. In addition, if the content of a nitrogen gas in the laser beam permeating liquid medium is reduced by degassing to lower than a predetermined value, or the laser beam permeating gaseous medium is formed by an inert gas, a laser marking having high corrosion resistance and reliability can be formed on the surface of the objective member. (N.H.)

Regulated eukaryotic DNA replication origin firing with purified proteins.

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Yeeles, Joseph T P; Deegan, Tom D; Janska, Agnieszka; Early, Anne; Diffley, John F X

2015-03-26

Eukaryotic cells initiate DNA replication from multiple origins, which must be tightly regulated to promote precise genome duplication in every cell cycle. To accomplish this, initiation is partitioned into two temporally discrete steps: a double hexameric minichromosome maintenance (MCM) complex is first loaded at replication origins during G1 phase, and then converted to the active CMG (Cdc45-MCM-GINS) helicase during S phase. Here we describe the reconstitution of budding yeast DNA replication initiation with 16 purified replication factors, made from 42 polypeptides. Origin-dependent initiation recapitulates regulation seen in vivo. Cyclin-dependent kinase (CDK) inhibits MCM loading by phosphorylating the origin recognition complex (ORC) and promotes CMG formation by phosphorylating Sld2 and Sld3. Dbf4-dependent kinase (DDK) promotes replication by phosphorylating MCM, and can act either before or after CDK. These experiments define the minimum complement of proteins, protein kinase substrates and co-factors required for regulated eukaryotic DNA replication.

DNA replication stress and cancer chemotherapy.

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Kitao, Hiroyuki; Iimori, Makoto; Kataoka, Yuki; Wakasa, Takeshi; Tokunaga, Eriko; Saeki, Hiroshi; Oki, Eiji; Maehara, Yoshihiko

2018-02-01

DNA replication is one of the fundamental biological processes in which dysregulation can cause genome instability. This instability is one of the hallmarks of cancer and confers genetic diversity during tumorigenesis. Numerous experimental and clinical studies have indicated that most tumors have experienced and overcome the stresses caused by the perturbation of DNA replication, which is also referred to as DNA replication stress (DRS). When we consider therapeutic approaches for tumors, it is important to exploit the differences in DRS between tumor and normal cells. In this review, we introduce the current understanding of DRS in tumors and discuss the underlying mechanism of cancer therapy from the aspect of DRS. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Termination of DNA replication forks: "Breaking up is hard to do".

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Bailey, Rachael; Priego Moreno, Sara; Gambus, Agnieszka

2015-01-01

To ensure duplication of the entire genome, eukaryotic DNA replication initiates from thousands of replication origins. The replication forks move through the chromatin until they encounter forks from neighboring origins. During replication fork termination forks converge, the replisomes disassemble and topoisomerase II resolves the daughter DNA molecules. If not resolved efficiently, terminating forks result in genomic instability through the formation of pathogenic structures. Our recent findings shed light onto the mechanism of replisome disassembly upon replication fork termination. We have shown that termination-specific polyubiquitylation of the replicative helicase component - Mcm7, leads to dissolution of the active helicase in a process dependent on the p97/VCP/Cdc48 segregase. The inhibition of terminating helicase disassembly resulted in a replication termination defect. In this extended view we present hypothetical models of replication fork termination and discuss remaining and emerging questions in the DNA replication termination field.

Validation of a closed bi-phasic extraction system and of the pancake probe as instruments to radiopharmaceutical quality control procedures

International Nuclear Information System (INIS)

Marques, F.L.N.; Okamoto, M.R.Y.; Sapienza, M.T.; Ferraro, G.C.

2002-01-01

Aim: Quality control of radiopharmaceuticals is not a common practice in Nuclear Medicine Services in Brazil. One frequent limitation is that the well counter, used to radioactivity measurement of chromatographic strips, is not available in most services. On the other hand, it's mandatory that all services have a pancake probe to control contaminations. The purpose of this study was to evaluate the accuracy of the quality control (QC) of technetium-99m labeled radiopharmaceuticals using a pancake probe, including chromatography of 99m Tc-MDP, 99m Tc-DMSA, 99m Tc-DMSA-V, 99m Tc-Pyp, 99m Tc-ECD, 99m Tc-Dextran, 99m Tc-colloid. Also, we had available a solvent extraction methods using a multi-use closed bi-phasic system to 99m Tc-ECD and 99m Tc-MIBI, to replace the classical single-use open bi-phasic system. Material and Methods: Classical chromatographic well counter reading and solvent extraction radiochemical controls were used as standards. To variant radiation reading method, pancake probe was covered with a lead disk 3 mm thick, with a 40x10 mm slit; the activity on chromatographic strips (80x10 mm) was read over the slit. The multi-use closed bi-phasic system was done closing the extremities of a 5 or 10 mL glass pipette using flame in the point side, and rubber septa in the other side. The pipette was filled with 2.5 or 3 mL, both organic solvent and aqueous NaCl 0.9 %; then two or three drops of the sample were applied and the tube shook during 30 seconds. Two minutes after, the activity was measured over each phase using the pancake detector. The same solvent mixture was used 3 times, with 48 h interval to allow radioactivity decay. Results: Radiochemical purity determined by the classical or the modified procedures showed Pearson's correlation of 0.973 (n=17) to chromatography; 0.993 to ECD (n=14) extraction and 0.919 to MIBI (n=21) extraction. Conclusion: Our findings suggest that the pancake can be used as a detection instrument in 99m Tc

Changes in nucleosome repeat lengths precede replication in the early replicating metallothionein II gene region of cells synchronized in early S phase