5,640 research outputs found
Clustering and dynamics of cytochrome bd-I complexes in the Escherichia coli plasma membrane in vivo.
No full textThe cytochrome bd-I complex of Escherichia coli is a respiratory terminal oxidase and an integral component of the cytoplasmic membrane. As with other respiratory components, the organization and dynamics of this complex in living membranes is unknown. We set out to visualize the distribution and dynamics of this complex in vivo. By exchanging cydB for cydB-gfpgcn4 on the E. coli chromosome, we produced a strain (YTL01) that expresses functional GFP-tagged cytochrome bd-I terminal oxidase complexes under wild-type genetic control. We imaged live YTL01 cells using video-rate epifluorescence and total internal reflection fluorescence (TIRF) microscopy in combination with fluorescence recovery after photobleaching (FRAP) and saw mobile spots of GFP fluorescence in plasma membranes. Numbers of GFP molecules per spot were quantified by step-wise photobleaching giving a broad distribution with a mean of approximately 76, indicating that cytochrome bd-I is concentrated in mobile patches in the E. coli plasma membrane. We hypothesize that respiration occurs in mobile membrane patches which we call 'respirazones'
A HIGH SPEED DIRECT DIGITAL FREQUENCY SYNTHESIZER USING A LOW POWER PIPELINED PARALLEL ACCUMULATOR
No full textISCAS.2002This work was supported by KOSEF through the MICROS at KAIST, Korea
Cytochrome bd displays significant quinol peroxidase activity
No full textCytochrome bd is a prokaryotic terminal oxidase that catalyses the electrogenic reduction of oxygen to water using ubiquinol as electron donor. Cytochrome bd is a tri-haem integral membrane enzyme carrying a low-spin haem
Text-fig. 3. Scheme of metapodial bones (mtt V) measurements in cave bears. Abbreviations: GL – greatest length, Bp – breadth of proximal end, Dp – depth of proximal end, SD – smallest breadth in medial part of diaphysis, Bd – depth of distal end, Dd – depth of distal end. Index of plumpness: ip = (Bd/GL)*100 (Withalm 2001). in Morphometric Analysis Of Metacarpal And Metatarsal Bones Of Cave Bears (Carnivora, Ursidae)
No full textText-fig. 3. Scheme of metapodial bones (mtt V) measurements in cave bears. Abbreviations: GL – greatest length, Bp – breadth of proximal end, Dp – depth of proximal end, SD – smallest breadth in medial part of diaphysis, Bd – depth of distal end, Dd – depth of distal end. Index of plumpness: ip = (Bd/GL)*100 (Withalm 2001).Published as part of Baryshnikov, Gennady F. & Puzachenko, Andrey Yu., 2017, Morphometric Analysis Of Metacarpal And Metatarsal Bones Of Cave Bears (Carnivora, Ursidae), pp. 7-47 in Fossil Imprint 73 (1-2) on page 9, DOI: 10.2478/if-2017-0001, http://zenodo.org/record/458627
BD Rhapsody WTA AbSeq Analysis
No full text<p>Dataset and codes for BD Rhapsody single cell analysis system.</p>
<p>Disclaimer: The set of codes are optimised for the associated dataset only. For detailed understanding of the analysis procesure, please refer to https://github.com/INGEN-HOPE/Single-Cell-Multi-Omics-Data-Analysis-for-BD-Rhapsody. For any kind queries, please refer to the corresponding author, or post your query on our GitHub page.</p>
An 800-MHz low-power direct digital frequency synthesizer with an on-chip D/A converter
No full textAn 800-MHz low-power direct digital frequency synthesizer (DDFS) with an on-chip digital-to-analog (D/A) converter is presented. The DDFS consists of a phase accumulator, two phase-to-sine converters, and a D/A converter. The high-speed operation of the DDFS is enabled by applying parallelism to the phase-to-sine converter and by including a D/A converter in a single chip. The on-chip D/A converter saves delay and power consumption due to interchip interconnections. The DDFS considerably reduces power consumption by using several low-power techniques. The pipelined parallel accumulator consumes only 22% power of a conventional pipelined accumulator with the same throughput. The quad line approximation (QLA) and the quantization and error ROM (QE-ROM) minimize the ROM to generate a sine wave. The QLA saves 4 bits of the sine amplitude by approximating the sine function with four lines. The QE-ROM quantizes the ROM data by magnitude and address and then it stores the quantized values and the quantization errors separately. The ROM size for a 9-bit sine output is only 368 bits. A DDFS chip is fabricated in a 0.35-mum CMOS process. It consumes only 174 mW at 800 MHz with 3.3 V. The chip core area is 1.47 mm(2). The spurious-free dynamic range (SFDR) is 55 dBe
Cytochrome bd displays significant quinol peroxidase activity
No full textCytochrome bd is a prokaryotic terminal oxidase that catalyses the electrogenic reduction of oxygen to water using ubiquinol as electron donor. Cytochrome bd is a tri-haem integral membrane enzyme carrying a low-spin haem b(558), and two high-spin haems: b(595) and d. Here we show that besides its oxidase activity, cytochrome bd from Escherichia coli is a genuine quinol peroxidase (QPO) that reduces hydrogen peroxide to water. The highly active and pure enzyme preparation used in this study did not display the catalase activity recently reported for E. coli cytochrome bd. To our knowledge, cytochrome bd is the first membrane-bound quinol peroxidase detected in E. coli. The observation that cytochrome bd is a quinol peroxidase, can provide a biochemical basis for its role in detoxification of hydrogen peroxide and may explain the frequent findings reported in the literature that indicate increased sensitivity to hydrogen peroxide and decreased virulence in mutants that lack the enzyme
Growth of number of periodic orbits of one family of skew product maps
No full textIn this article we introduce a one-parameter family of skew product (Gt)t ∈ [−ε, ε] maps exhibiting a heterodimensional cycle such that the number of isolated periodic orbits inside it has not super-exponential growth. The dynamics in the central direction of the maps Gt is described by a one-parameter family of system of iterated functions.This work is part of the PhD thesis of the author, under the supervision
of Lorenzo Diaz and Jorge Rocha. The author thanks Professors Lorenzo Diaz and Jorge Rocha, for
having proposed this topic, by the stimulating conversations, the guidance and useful suggestions.
This research was funded by by the Portuguese government through the FCT (Fundação para a
Ciência e a Tecnologia) under the project PTDC/MAT/099493/2008. The author was supported by
the grants SFRH/BD/27674/2006 and SFRH/BD/49735/2009 of FCT.info:eu-repo/semantics/publishedVersio
Community influences on E/BD student achievement
No full textNo Child Left Behind has mandated that all students reach proficiency by 2014. This mandate places special emphasis on the performance of special education students. The purpose of this study is to use social theory to understand the factors that explain the achievement of emotionally or behaviorally disordered (E/BD) students. Results suggest a differential effect of neighborhood composition on the development of social ties for Black and White E/BD students. The author argues for an increased awareness of the development of within-school social ties that integrate groups. © 2008 Corwin Press, Inc.link_to_subscribed_fulltex
Comparing the delivery to the hair bulb of two fluorescent molecules of distinct hydrophilicities by different nanoparticles and a serum formulation
No full textThe follicular route is an important drug penetration pathway in any topical application, either concerning dermatological and cosmetic skin treatments or any transdermal administration regimen. Efficient transport into follicles will depend on drug inherent properties but also on the chosen vehicle. The main study goal was to compare several systems for the delivery to the hair bulb of two fluorescent molecules of different water affinities: the hydrophobic Nile Red and the quite similar but hydrophilic Nile Blue. Three common nanoparticle types were compared in terms of encapsulation efficiency and stability: liposomes, ethosomes and polymeric nanoparticles. A liquid serum-like formulation was also developed, adjusting the final ethanol amount to the type of dye to be solubilized. Then, this formulation and the nanoparticle systems that successfully passed characterization and stability stages were further studied on their ability to reach the bulb. The serum formulation was able to deliver, both drug models, to deeper follicular regions than nanoparticles. Attending to the envisioned zone target of the follicle, the simplest approach proved to be the best choice from all the systems tested in this work. Nonetheless, nanocarriers and the inherent complexity of their manufacturing processes may be justified under very specific requirements.The author Cristiana Costa would like to acknowledge his PhD scholarship funded by Portuguese
Foundation for Science and Technology (FCT) (SFRH/BD/139522/2018). The author Bruno
Fernandes would like to acknowledge his PhD scholarship funded by FCT (SFRH/BD/131824/2017).
The author Diana Guimarães would like to acknowledge his PhD scholarship funded by FCT
(SFRH/BD/140321/2018). This study was supported by the FCT under the scope of BioTecNorte
operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund
under the scope of Norte2020 – Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio
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