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Sample records for versatile fluorene-degrading bacterial

  1. Fabrication of antimicrobial bacterial cellulose-Ag/AgCl nanocomposite using bacteria as versatile biofactory

    Science.gov (United States)

    Liu, Chuang; Yang, Dong; Wang, Yuangui; Shi, Jiafu; Jiang, Zhongyi

    2012-08-01

    In nature, a number of nanocomposites are formed through biomineralization-relevant processes under mild conditions. In the present study, a total "biologic" route to fabricate nanocomposite is reported. Non-pathogenic bacteria, Gluconacetobacter xylinum, was utilized as a versatile biofactory, which produced biopolymer bacterial cellulose (BC) and induced the formation of Ag/AgCl nanoparticles, yielding BC-Ag/AgCl nanocomposite. Scanning electron microscopy revealed that nanoparticles with average size of 17.4 nm were randomly embedded into the BC network; transmission electron microscopy and X-ray diffraction confirmed that the nanoparticles were mixtures of face-centered cubic silver and silver chloride nanoparticles. Moreover, the content of silver in the BC nanocomposite is around 0.05 wt%, determined by atomic absorption spectrometry and X-ray photoelectron spectroscopy analysis. The entire process of nanocomposite fabrication was conducted at ambient environment without utilizing toxic agents or producing hazardous products, which is not only environmentally friendly but also with less chances to generate harmful products to human bodies as biomedical materials. The resultant nanocomposite displayed the desirable activity in inhibiting bacterial growth of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli microorganisms on agar plate and in liquid culture, indicating the potential of the material as antimicrobial wound dressing materials. This work demonstrated the feasibility of using microorganism to fabricate nanocomposite, especially for biomedical materials.

  2. Fabrication of antimicrobial bacterial cellulose-Ag/AgCl nanocomposite using bacteria as versatile biofactory

    Energy Technology Data Exchange (ETDEWEB)

    Liu Chuang [Tianjin University, Key Laboratory for Green Technology, School of Chemical Engineering and Technology (China); Yang Dong; Wang Yuangui [Tianjin University, Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of Ministry of Education, School of Chemical Engineering and Technology (China); Shi Jiafu; Jiang Zhongyi, E-mail: zhyjiang@tju.edu.cn [Tianjin University, Key Laboratory for Green Technology, School of Chemical Engineering and Technology (China)

    2012-08-15

    In nature, a number of nanocomposites are formed through biomineralization-relevant processes under mild conditions. In the present study, a total 'biologic' route to fabricate nanocomposite is reported. Non-pathogenic bacteria, Gluconacetobacter xylinum, was utilized as a versatile biofactory, which produced biopolymer bacterial cellulose (BC) and induced the formation of Ag/AgCl nanoparticles, yielding BC-Ag/AgCl nanocomposite. Scanning electron microscopy revealed that nanoparticles with average size of 17.4 nm were randomly embedded into the BC network; transmission electron microscopy and X-ray diffraction confirmed that the nanoparticles were mixtures of face-centered cubic silver and silver chloride nanoparticles. Moreover, the content of silver in the BC nanocomposite is around 0.05 wt%, determined by atomic absorption spectrometry and X-ray photoelectron spectroscopy analysis. The entire process of nanocomposite fabrication was conducted at ambient environment without utilizing toxic agents or producing hazardous products, which is not only environmentally friendly but also with less chances to generate harmful products to human bodies as biomedical materials. The resultant nanocomposite displayed the desirable activity in inhibiting bacterial growth of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli microorganisms on agar plate and in liquid culture, indicating the potential of the material as antimicrobial wound dressing materials. This work demonstrated the feasibility of using microorganism to fabricate nanocomposite, especially for biomedical materials.

  3. The bacterial-fungal energy channel concept challenged by enormous functional versatility of soil protists

    NARCIS (Netherlands)

    Geisen, Stefan

    2016-01-01

    Abstract Protists (=protozoa) are commonly treated as bacterivores that control the bacterial energy channel in soil food webs. This ecologist’s perspective is, however, challenged by taxonomic studies showing that a range of protists feed on fungi, other protists and even nematodes. Recently, it

  4. Modification and Assembly of a Versatile Lactonase for Bacterial Quorum Quenching

    Directory of Open Access Journals (Sweden)

    Melissa K. Rhoads

    2018-02-01

    Full Text Available This work sets out to provide a self-assembled biopolymer capsule activated with a multi-functional enzyme for localized delivery. This enzyme, SsoPox, which is a lactonase and phosphotriesterase, provides a means of interrupting bacterial communication pathways that have been shown to mediate pathogenicity. Here we demonstrate the capability to express, purify and attach SsoPox to the natural biopolymer chitosan, preserving its activity to “neutralize” long-chain autoinducer-1 (AI-1 communication molecules. Attachment is shown via non-specific binding and by engineering tyrosine and glutamine affinity ‘tags’ at the C-terminus for covalent linkage. Subsequent degradation of AI-1, in this case N-(3-oxododecanoyl-l-homoserine lactone (OdDHL, serves to “quench” bacterial quorum sensing (QS, silencing intraspecies communication. By attaching enzymes to pH-responsive chitosan that, in turn, can be assembled into various forms, we demonstrate device-based flexibility for enzyme delivery. Specifically, we have assembled quorum-quenching capsules consisting of an alginate inner core and an enzyme “decorated” chitosan shell that are shown to preclude bacterial QS crosstalk, minimizing QS mediated behaviors.

  5. Perspectives of medium chain length poly(hydroxyalkanoates), a versatile set of bacterial bioplastics

    Science.gov (United States)

    Witholt; Kessler

    1999-06-01

    Medium chain length (mcl) poly(hydroxyalkanoic acids) (PHAs) are polyesters accumulated by fluorescent Pseudomonads and other bacteria. Work on the genetics of mcl-PHA formation has led to polymer synthesis in recombinant bacteria and plants. Several high and medium cost applications are now emerging. With optimized bacterial mcl-PHA synthesis on inexpensive agro-substrates and the development of plant-based mcl-PHAs in the next decade, the production economics of these bioplastics will ultimately permit their sustainable production for bulk applications.

  6. Surface-modified nanoparticles as a new, versatile, and mechanically robust nonadhesive coating : Suppression of protein adsorption and bacterial adhesion

    NARCIS (Netherlands)

    Holmes, P. F.; Currie, E. P. K.; Thies, J. C.; van der Mei, H. C.; Busscher, H. J.; Norde, W.

    2009-01-01

    The synthesis of surface-modified silica nanoparticles, chemically grafted with acrylate and poly(ethylene glycol) (PEG) groups, and the ability of the resulting crosslinked coatings to inhibit protein adsorption and bacterial adhesion are explored. Water contact angles, nanoindentation, and atomic

  7. An easy and versatile 2-step protocol for targeted modification and subcloning of DNA from bacterial artificial chromosomes using non-commercial plasmids

    Directory of Open Access Journals (Sweden)

    Hartwich Heiner

    2012-03-01

    Full Text Available Abstract Background Promoter-specific expression of foreign DNA in transgenic organisms often relies on bacterial artificial chromosomes (BACs. This approach requires modification and subcloning of BAC-DNA by recombineering technologies in Escherichia coli. Most current protocols rely on commercial kits or isolation of BACs, their transfer between different host strains, and their restriction. Findings In this report we present a 2-step protocol for efficient modification and subcloning of DNA from bacterial artificial chromosomes using the non-commercial plasmids pKM208 and pTP223, distributed from addgene.com. A targeting cassette was successfully integrated into a BAC and 42 kb of this construct were subcloned. Both a plasmid-derived substrate with longer homology arms and a PCR-generated substrate with short homology arms (50 bp were used for recombination. pKM208 and pTP223 contain all required genes for recombineering, but differ in their antibiotic resistance genes. This makes the system independent of the selection markers on the DNA molecules targeted for recombination. Conclusions The time and cost saving protocol presented here compares favorably to currently used systems. Using non-commercial plasmids, it allows targeted modification and cloning of large DNA (> 40 kb fragments in vivo without restriction and ligation. Furthermore, both steps are performed in the same host eliminating the need to isolate BAC DNA and to use different bacterial strains.

  8. An easy and versatile 2-step protocol for targeted modification and subcloning of DNA from bacterial artificial chromosomes using non-commercial plasmids.

    Science.gov (United States)

    Hartwich, Heiner; Nothwang, Hans Gerd

    2012-03-20

    Promoter-specific expression of foreign DNA in transgenic organisms often relies on bacterial artificial chromosomes (BACs). This approach requires modification and subcloning of BAC-DNA by recombineering technologies in Escherichia coli. Most current protocols rely on commercial kits or isolation of BACs, their transfer between different host strains, and their restriction. In this report we present a 2-step protocol for efficient modification and subcloning of DNA from bacterial artificial chromosomes using the non-commercial plasmids pKM208 and pTP223, distributed from addgene.com. A targeting cassette was successfully integrated into a BAC and 42 kb of this construct were subcloned. Both a plasmid-derived substrate with longer homology arms and a PCR-generated substrate with short homology arms (50 bp) were used for recombination. pKM208 and pTP223 contain all required genes for recombineering, but differ in their antibiotic resistance genes. This makes the system independent of the selection markers on the DNA molecules targeted for recombination. The time and cost saving protocol presented here compares favorably to currently used systems. Using non-commercial plasmids, it allows targeted modification and cloning of large DNA (> 40 kb) fragments in vivo without restriction and ligation. Furthermore, both steps are performed in the same host eliminating the need to isolate BAC DNA and to use different bacterial strains. © 2011 Hartwich et al; licensee BioMed Central Ltd.

  9. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

    Science.gov (United States)

    Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  10. Glycodendrimers: versatile tools for nanotechnology

    Directory of Open Access Journals (Sweden)

    René Roy

    2013-01-01

    Full Text Available Combining nanotechnology with glycobiology has triggered an exponential growth of research activities in the design of novel functional bionanomaterials (glyconanotechnology. More specifically, recent synthetic advances towards the tailored and versatile design of glycosylated nanoparticles namely glyconanoparticles, considered as synthetic mimetics of natural glycoconjugates, paved the way toward diverse biomedical applications. The accessibility of a wide variety of these structured nanosystems, in terms of shapes, sizes, and organized around stable nanoparticles have readily contributed to their development and applications in nanomedicine. In this context, glycosylated gold-nanoparticles (GNPs, glycosylated quantum dots (QDs, fullerenes, single-wall natotubes (SWNTs, and self-assembled glycononanoparticles using amphiphilic glycopolymers or glycodendrimers have received considerable attention to afford powerful imaging, therapeutic, and biodiagnostic devices. This review will provide an overview of the most recent syntheses and applications of glycodendrimers in glycoscience that have permitted to deepen our understanding of multivalent carbohydrate-protein interactions. Together with synthetic breast cancer vaccines, inhibitors of bacterial adhesions to host tissues including sensitive detection devices, these novel bionanomaterials are finding extensive relevance.

  11. Versatility of microbial transglutaminase.

    Science.gov (United States)

    Strop, Pavel

    2014-05-21

    Although microbial transglutaminases (mTGs) were initially discovered to offset the cost of producing mammalian transglutaminases for food applications, they have quickly become important tools in research and biotechnology. Today, mTGs are utilized for a large number of applications to conjugate proteins and peptides to small molecules, polymers, surfaces, and DNA, as well as to other proteins. It is important to know how to maximize the advantages of the enzymatic approach and avoid undesired cross-linking. This review focuses on the versatility of transglutaminases in the field of bioconjugation and covers recent developments in utilizing mTG for generating antibody drug conjugates (ADCs) for therapeutic applications.

  12. Applying technical versatility

    Energy Technology Data Exchange (ETDEWEB)

    None

    1970-01-01

    The breadth and depth of the diversified technical programs at Mound Laboratory since its inception are characterized by a record of competence and versatility during the past generation. A spectrum of mission assignments has been completed successfully in such diverse technical areas as process development and manufacturing of explosive components, research on fuels for the Civilian Power Reactor Program, separation of radioactive materials, fabrication of radioisotopic heat sources, stable gaseous isotope separation and purification, and many other areas. Mound Laboratory is one of the key U.S. Atomic Energy Commission sites that has demonstrated its technical competence in both weapons and non-weapons activities. This report has been prepared to complement the AEC’s vigorous program of scientific information dissemination. Three broad areas of technical competence are highlighted here: explosive technology, radionuclide technology, and stable gaseous isotope separation, which encompass a broad variety of techniques and supporting disciplines.

  13. Holographic versatile disc system

    Science.gov (United States)

    Horimai, Hideyoshi; Tan, Xiaodi

    2005-09-01

    A Holographic Versatile Disc (HVD) system, using Collinear Technologies for a high capacity and high data transfer rates storage system, is proposed. With its unique configuration the optical pickup can be designed as small as a DVD's, and can be placed on one side of the disc. With the HVD's special structure, the system can servo the focus/track and locate reading/writing address. A unique selectable capacity recording format of HVD and its standardization activity are also introduced. Experimental and theoretical studies suggest that the tilt, wavelength, defocus and de-track margins are wide enough to miniaturize the HVD system at a low cost. HVD systems using Collinear Technologies will be compatible with existing disc storage systems, like CD and DVD, and will enable us to expand its applications into other optical information storage systems.

  14. Versatile by design

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    CHARM (CERN High energy AcceleRator Mixed field) is a new and unique testing facility that will complete CERN's radiation testing installations. Located in the East Area, CHARM will provide teams with a venue to test their equipment in radiation environments similar to those found in the accelerator chain.   Team at work in the irradiation zone of the CHARM facility. First envisaged in 2007, the CHARM facility fulfils a growing demand for a large-scale tailor-made radiation testing facility. Unlike commercial facilities, CHARM features a wide spectrum of radiation types and energies (called mixed-field radiation environments), the space to test large equipment and even the possibility to adjust the environment using mobile shielding. "CHARM is versatile by design, allowing us to recreate any of the radiation environments found in the accelerator chain," says Markus Brugger, head of the R2E (Radiation to Electronics) project team that developed the CHARM facility. &a...

  15. Trypanosomes - versatile microswimmers

    Science.gov (United States)

    Krüger, Timothy; Engstler, Markus

    2016-11-01

    Evolution has generated a plethora of flagellate microswimmers. They populate all natural waters, from the deep sea to the ponds in our neighbourhood. But flagellates also thrive in the bodies of higher organisms, where they mostly remain undetected, but can also become pathogenic. Trypanosomes comprise a large group of mostly parasitic flagellates that cause many diseases, such as human sleeping sickness or the cattle plague nagana. We consider African trypanosomes as extremely versatile microswimmers, as they have to adapt to very diverse microenvironments. They swim efficiently in the blood of their mammalian hosts, but also in various tissue spaces and even in the human brain. Furthermore, in the transmitting tsetse fly, trypanosomes undergo characteristic morphological changes that are accompanied by amazing transitions between solitary and collective types of motion. In this review, we provide a basic introduction to trypanosome biology and then focus on the complex type of rotational movement that trypanosomes display. We relate their swimming performance to morphological parameters and the respective microenvironment, developing a contemporary view on the physics of trypanosome motility. The genetically programmed successions of life style-dependent motion patterns provide challenges and opportunities for interdisciplinary studies of microswimmers.

  16. Versatile Wireless Data Net Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed R&D is to develop a wireless data networking capability. A prototype capability will result from the Phase 1 and 2 contracts. The Versatile Wireless...

  17. DVD - digital versatile disks

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, R.

    1997-05-01

    An international standard has emerged for the first true multimedia format. Digital Versatile Disk (by its official name), you may know it as Digital Video Disks. DVD has applications in movies, music, games, information CD-ROMS, and many other areas where massive amounts of digital information is needed. Did I say massive amounts of data? Would you believe over 17 gigabytes on a single piece of plastic the size of an audio-CD? That`s the promise, at least, by the group of nine electronics manufacturers who have agreed to the format specification, and who hope to make this goal a reality by 1998. In this major agreement, which didn`t come easily, the manufacturers will combine Sony and Phillip`s one side double-layer NMCD format with Toshiba and Matsushita`s double sided Super-Density disk. By Spring of this year, they plan to market the first 4.7 gigabyte units. The question is: Will DVD take off? Some believe that read-only disks recorded with movies will be about as popular as video laser disks. They say that until the eraseable/writable DVD arrives, the consumer will most likely not buy it. Also, DVD has a good market for replacement of CD- Roms. Back in the early 80`s, the international committee deciding the format of the audio compact disk decided its length would be 73 minutes. This, they declared, would allow Beethoven`s 9th Symphony to be contained entirely on a single CD. Similarly, today it was agreed that playback length of a single sided, single layer DVD would be 133 minutes, long enough to hold 94% of all feature-length movies. Further, audio can be in Dolby`s AC-3 stereo or 5.1 tracks of surround sound, better than CD-quality audio (16-bits at 48kHz). In addition, there are three to five language tracks, copy protection and parental ``locks`` for R rated movies. DVD will be backwards compatible with current CD-ROM and audio CD formats. Added versatility comes by way of multiple aspect rations: 4:3 pan-scan, 4:3 letterbox, and 16:9 widescreen. MPEG

  18. Temperature characterization of versatile transceivers

    CERN Document Server

    Olanterä, L.; Storey, S; Sigaud, C; Soos, C; Troska, J; Vasey, F

    2013-01-01

    The Versatile Transceiver is a part of the Versatile Link project, which is developing optical link architectures and components for future HL-LHC experiments. While having considerable size and weight constraints, Versatile Transceivers must work under severe environmental conditions. One such environmental parameter is the temperature: the operating temperature range is specified to be from -30 to +60°C. In this contribution we present the results of the temperature characterization of the VTRx transmitter and receiver. Several transmitter candidates from three different manufacturers have been characterized: multi-mode Vertical Cavity Surface-Emitting Lasers and a single-mode Edge-Emitter Laser. Also both single- and multi-mode receivers have been tested.

  19. Xanthan-A Versatile Gum

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 10. Xanthan – A Versatile Gum. Anil Lachke. General Article Volume 9 Issue 10 October 2004 pp 25-33. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/10/0025-0033. Keywords. Xanthan ...

  20. Imidazole: Having Versatile Biological Activities

    Directory of Open Access Journals (Sweden)

    Amita Verma

    2013-01-01

    Full Text Available Imidazoles have occupied a unique position in heterocyclic chemistry, and its derivatives have attracted considerable interests in recent years for their versatile properties in chemistry and pharmacology. Imidazole is nitrogen-containing heterocyclic ring which possesses biological and pharmaceutical importance. Thus, imidazole compounds have been an interesting source for researchers for more than a century. The imidazole ring is a constituent of several important natural products, including purine, histamine, histidine, and nucleic acid. Being a polar and ionisable aromatic compound, it improves pharmacokinetic characteristics of lead molecules and thus is used as a remedy to optimize solubility and bioavailability parameters of proposed poorly soluble lead molecules. There are several methods used for the synthesis of imidazole-containing compounds, and also their various structure reactions offer enormous scope in the field of medicinal chemistry. The imidazole derivatives possess extensive spectrum of biological activities such as antibacterial, anticancer, antitubercular, antifungal, analgesic, and anti-HIV activities. This paper aims to review the biological activities of imidazole during the past years.

  1. Bacterial Keratitis

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Bacterial Keratitis Sections What Is Bacterial Keratitis? Bacterial Keratitis Symptoms ... Lens Care Bacterial Keratitis Treatment What Is Bacterial Keratitis? Leer en Español: ¿Qué Es la Queratitis Bacteriana? ...

  2. Methanol: A Versatile Fuel for Immediate Use

    Science.gov (United States)

    Reed, T. B.; Lerner, R. M.

    1973-01-01

    Advocates the large-scale production and use of methanol as a substitute for the diminishing reserves of low-cost petroleum resources. Describes the manufacturing process and advantages of the versatile fuel. (JR)

  3. Bioremediation of polycyclic aromatic hydrocarbon (PAH compounds: (acenaphthene and fluorene in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Oluwadara Oluwaseun Alegbeleye

    Full Text Available Abstract This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa and their ability to degrade two PAH compounds: acenaphthene and fluorene. A total of 19 bacterial isolates were obtained from the Diep and Plankenburg rivers among which four were identified as acenaphthene and fluorene degrading isolates. In simulated batch scale experiments, the optimum temperature for efficient degradation of both compounds was determined in a shaking incubator after 14 days, testing at 25 °C, 30 °C, 35 °C, 37 °C, 38 °C, 40 °C and 45 °C followed by experiments in a Stirred Tank Bioreactor using optimum temperature profiles from the batch experiment results. All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded both compounds at 37 °C, 37 °C, 30 °C and 35 °C respectively. The degradation of fluorene was more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila degraded a mean total of 98.60%, 95.70%, 90.20% and 99.90% acenaphthene, respectively and 99.90%, 97.90%, 98.40% and 99.50% fluorene, respectively. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and may be used on a larger, commercial scale to bioremediate PAH contaminated river systems.

  4. Guinea Pigs: Versatile Animals for the Classroom

    Science.gov (United States)

    Barman, Charles R.

    1977-01-01

    Guinea pigs are presented as versatile classroom animals. Suggestions for animal behavior and genetics studies are given. Also included is information concerning sex determination and the breeding of guinea pigs, and hints on keeping these animals in the classroom. References and illustrations complete the article. (MA)

  5. A Versatile Technique for Solving Quintic Equations

    Science.gov (United States)

    Kulkarni, Raghavendra G.

    2006-01-01

    In this paper we present a versatile technique to solve several types of solvable quintic equations. In the technique described here, the given quintic is first converted to a sextic equation by adding a root, and the resulting sextic equation is decomposed into two cubic polynomials as factors in a novel fashion. The resultant cubic equations are…

  6. Versatility of nodal affiliation to communities.

    Science.gov (United States)

    Shinn, Maxwell; Romero-Garcia, Rafael; Seidlitz, Jakob; Váša, František; Vértes, Petra E; Bullmore, Edward

    2017-06-27

    Graph theoretical analysis of the community structure of networks attempts to identify the communities (or modules) to which each node affiliates. However, this is in most cases an ill-posed problem, as the affiliation of a node to a single community is often ambiguous. Previous solutions have attempted to identify all of the communities to which each node affiliates. Instead of taking this approach, we introduce versatility, V, as a novel metric of nodal affiliation: V ≈ 0 means that a node is consistently assigned to a specific community; V > 0 means it is inconsistently assigned to different communities. Versatility works in conjunction with existing community detection algorithms, and it satisfies many theoretically desirable properties in idealised networks designed to maximise ambiguity of modular decomposition. The local minima of global mean versatility identified the resolution parameters of a hierarchical community detection algorithm that least ambiguously decomposed the community structure of a social (karate club) network and the mouse brain connectome. Our results suggest that nodal versatility is useful in quantifying the inherent ambiguity of modular decomposition.

  7. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  8. The Versatile Link Demo Board (VLDB)

    Science.gov (United States)

    Martín Lesma, R.; Alessio, F.; Barbosa, J.; Baron, S.; Caplan, C.; Leitao, P.; Pecoraro, C.; Porret, D.; Wyllie, K.

    2017-02-01

    The Versatile Link Demonstrator Board (VLDB) is the evaluation kit for the radiation-hard Optical Link ecosystem, which provides a 4.8 Gbps data transfer link for communication between front-end (FE) and back-end (BE) of the High Energy Physics experiments. It gathers the Versatile link main radiation-hard custom Application-Specific Integrated Circuits (ASICs) and modules: GBTx, GBT-SCA and VTRx/VTTx plus the FeastMP, a radiation-hard in-house designed DC-DC converter. This board is the first design allowing system-level tests of the Link with a complete interconnection of the constitutive components, allowing data acquisition, control and monitoring of FE devices with the GBT-SCA pair.

  9. How versatile are inositol phosphate kinases?

    OpenAIRE

    Shears, Stephen B.

    2004-01-01

    This review assesses the extent and the significance of catalytic versatility shown by several inositol phosphate kinases: the inositol phosphate multikinase, the reversible Ins(1,3,4) P (3)/Ins(3,4,5,6) P (4) kinase, and the kinases that synthesize diphosphoinositol polyphosphates. Particular emphasis is placed upon data that are relevant to the situation in vivo. It will be shown that catalytic promiscuity towards different inositol phosphates is not typically an evolutionary compromise, bu...

  10. Isatin, a versatile molecule: studies in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Barbara, E-mail: barbara.iq@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-05-15

    Isatin is a small, versatile and widely applicable pharmacological molecule. These characteristics make isatin and its derivatives attractive to many research groups as resources for chemical and pharmacological studies. Although it has a relatively simple structure, isatin is a useful chemical scaffold for a variety of chemical transformations. This article discusses several studies performed by Brazilian groups, including investigations of its structural changes, biological assay designs and new methods for the synthesis of isatin. (author)

  11. Bacterial conjunctivitis

    OpenAIRE

    Epling, John

    2012-01-01

    Conjunctivitis causes irritation, itching, foreign body sensation, and watering or discharge of the eye. Most cases in adults are probably due to viral infection, but children are more likely to develop bacterial conjunctivitis than viral forms. The main bacterial pathogens are Staphylococcus species in adults, and Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children.A bacterial cause is more likely if there is gluing of the eyelids and no itch.Contact le...

  12. Bacterial conjunctivitis

    OpenAIRE

    Epling, John

    2010-01-01

    Conjunctivitis causes irritation, itching, foreign body sensation, and watering or discharge of the eye. Most cases in adults are probably due to viral infection, but children are more likely to develop bacterial conjunctivitis than viral forms. The main bacterial pathogens are Staphylococcus species in adults, and Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children.A bacterial cause is more likely if there is glueing of the eyelids and no itch.Contact l...

  13. Bacterial Meningitis

    Science.gov (United States)

    ... Vaccine Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Language: English (US) Español (Spanish) Recommend on ... Symptoms Diagnosis Treatment Prevention Reference Español: Meningitis bacteriana Bacterial meningitis is very serious and can be deadly. Death ...

  14. Bacterial adhesion

    NARCIS (Netherlands)

    Loosdrecht, van M.C.M.

    1988-01-01

    As mentioned in the introduction of this thesis bacterial adhesion has been studied from a variety of (mostly practice oriented) starting points. This has resulted in a range of widely divergent approaches. In order to elucidate general principles in bacterial adhesion phenomena, we felt it

  15. Effective and versatile software beamformation toolbox

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Nikolov, Svetoslav; Jensen, Jørgen Arendt

    2007-01-01

    aperture to obtain a preferred constant F-number. An effective and versatile software toolbox for off-line beamformation designed to address all of these issues has been developed. It is capable of exploiting parallelization of computations on a Linux cluster and is written in C++ with a MATLAB (Math Works...... and stored in lookup-tables (LUT). Parametric beamforming can also be applied where calculations are done by demand, thus, reducing the storage demand dramatically. On a standard PC with a Pentium 4, 2.66 GHz processor running Linux the toolbox can beamform 100,000 points in lines of various directions in 20...

  16. Microbial nitrilases: versatile, spiral forming, industrial enzymes

    CSIR Research Space (South Africa)

    Thuku, RN

    2009-03-01

    Full Text Available (Osswald et al., 2002). The heterologous expression of bacterial nitrilases in plants has also been achieved. The nitrilase of Klebsiella pneumoniae subsp. ozaenae is highly specific for the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile...

  17. Bacterial Vaginosis

    Science.gov (United States)

    ... Pediatrician Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions Cleft & Craniofacial Developmental ... most common vaginal infection in sexually active teenaged girls . It appears to be caused by a bacterial ...

  18. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  19. Versatile and Extensible, Continuous-Thrust Trajectory Optimization Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop an innovative, versatile and extensible, continuous-thrust trajectory optimization tool for planetary mission design and optimization of...

  20. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  1. Collinear technology for a holographic versatile disk

    Science.gov (United States)

    Horimai, Hideyoshi; Tan, Xiaodi

    2006-02-01

    A novel reading and writing technology for a holographic versatile disk (HVD) system called collinear technology is developed. With this method a two-dimensional data page can be recorded as volumetric holograms generated by a reference beam and a signal beam that are bundled on the same axis and that are irradiated on the recording medium through a single objective lens. The multiplex recording and reconstruction process is demonstrated, and it is shown that the optical configuration and the dichroic medium disk structure are suitable for a compact system. With the HVD's special structure, the system can use a servo to focus, track, and locate the reading and writing addresses. A unique selectable-capacity recording format of a HVD and its standardization activity are also introduced. This method will enable us to construct a small HVD system with CD and DVD upper compatibilities.

  2. Bacterial conjunctivitis.

    Science.gov (United States)

    Epling, John

    2012-02-20

    Most cases of conjunctivitis in adults are probably due to viral infection, but children are more likely to develop bacterial conjunctivitis than they are viral forms. The main bacterial pathogens are Haemophilus influenzae and Streptococcus pneumoniae in adults and children, and Moraxella catarrhalis in children. Contact lens wearers may be more likely to develop gram-negative infections. Bacterial keratitis occurs in up to 30 per 100,000 contact lens wearers. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of empirical treatment in adults and children with suspected bacterial conjunctivitis? What are the effects of treatment in adults and children with bacteriologically confirmed bacterial conjunctivitis? What are the effects of treatment in adults and children with clinically confirmed gonococcal conjunctivitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 44 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: ocular decongestants, oral antibiotics, parenteral antibiotics, saline, topical antibiotics, and warm compresses.

  3. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge

    KAUST Repository

    Tian, Renmao

    2014-08-29

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge.

    Science.gov (United States)

    Tian, Ren-Mao; Wang, Yong; Bougouffa, Salim; Gao, Zhao-Ming; Cai, Lin; Bajic, Vladimir; Qian, Pei-Yuan

    2014-11-01

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. BACTERIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  6. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  7. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

  8. Bacterial meningitis

    NARCIS (Netherlands)

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  9. Bacterial Cryoprotectants

    Indian Academy of Sciences (India)

    culture plate, whereas no growth was detected under similar conditions without betaine. They also observed that uptake of betaine into the bacterial cell was .... lar content of bound water, and (4) modifying the growth of ice crystals in the extracellular environment. Conclusion. At the present time, betaine serves as a model ...

  10. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...

  11. Bacterial Cryoprotectants

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 11. Bacterial Cryoprotectants. M K Chattopadhyay. General Article Volume 7 Issue 11 November 2002 pp 59-63. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/007/11/0059-0063. Keywords.

  12. Development of versatile multiaperture negative ion sources

    Science.gov (United States)

    Cavenago, M.; Serianni, G.; Antoni, V.; Bigi, M.; De Muri, M.; Pasqualotto, R.; Recchia, M.; Veltri, P.; Agostinetti, P.; Barbisan, M.; Baseggio, L.; Cervaro, V.; Cazzador, M.; Degli Agostini, F.; Franchin, L.; Kulevoy, T.; Laterza, B.; Mimo, A.; Minarello, A.; Petrenko, S.; Ravarotto, D.; Rossetto, F.; Sattin, M.; Zaniol, B.; Zucchetti, S.

    2015-04-01

    Enhancement of negative ion sources for production of large ion beams is a very active research field nowadays, driven from demand of plasma heating in nuclear fusion devices and accelerator applications. As a versatile test bench, the ion source NIO1 (Negative Ion Optimization 1) is being commissioned by Consorzio RFX and INFN. The nominal beam current of 135 mA at -60 kV is divided into 9 beamlets, with multiaperture extraction electrodes. The plasma is sustained by a 2 MHz radiofrequency power supply, with a standard matching box. A High Voltage Deck (HVD) placed inside the lead shielding surrounding NIO1 contains the radiofrequency generator, the gas control, electronics and power supplies for the ion source. An autonomous closed circuit water cooling system was installed for the whole system, with a branch towards the HVD, using carefully optimized helical tubing. Insulation transformer is installed in a nearby box. Tests of several magnetic configurations can be performed. Status of experiments, measured spectra and plasma luminosity are described. Upgrades of magnetic filter, beam calorimeter and extraction grid and related theoretical issues are reviewed.

  13. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H2O, and CO2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  14. Plasmonic Biofoam: A Versatile Optically Active Material.

    Science.gov (United States)

    Tian, Limei; Luan, Jingyi; Liu, Keng-Ku; Jiang, Qisheng; Tadepalli, Sirimuvva; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2016-01-13

    Owing to their ability to confine and manipulate light at the nanoscale, plasmonic nanostructures are highly attractive for a broad range of applications. While tremendous progress has been made in the synthesis of size- and shape-controlled plasmonic nanostructures, their integration with other materials and application in solid-state is primarily through their assembly on rigid two-dimensional (2D) substrates, which limits the plasmonically active space to a few nanometers above the substrate. In this work, we demonstrate a simple method to create plasmonically active three-dimensional biofoams by integrating plasmonic nanostructures with highly porous biomaterial aerogels. We demonstrate that plasmonic biofoam is a versatile optically active platform that can be harnessed for numerous applications including (i) ultrasensitive chemical detection using surface-enhanced Raman scattering; (ii) highly efficient energy harvesting and steam generation through plasmonic photothermal heating; and (iii) optical control of enzymatic activity by triggered release of biomolecules encapsulated within the aerogel. Our results demonstrate that 3D plasmonic biofoam exhibits significantly higher sensing, photothermal, and loading efficiency compared to conventional 2D counterparts. The design principles and processing methodology of plasmonic aerogels demonstrated here can be broadly applied in the fabrication of other functional foams.

  15. Bacterial Carriers for Glioblastoma Therapy

    Directory of Open Access Journals (Sweden)

    Nalini Mehta

    2017-03-01

    Full Text Available Treatment of aggressive glioblastoma brain tumors is challenging, largely due to diffusion barriers preventing efficient drug dosing to tumors. To overcome these barriers, bacterial carriers that are actively motile and programmed to migrate and localize to tumor zones were designed. These carriers can induce apoptosis via hypoxia-controlled expression of a tumor suppressor protein p53 and a pro-apoptotic drug, Azurin. In a xenograft model of human glioblastoma in rats, bacterial carrier therapy conferred a significant survival benefit with 19% overall long-term survival of >100 days in treated animals relative to a median survival of 26 days in control untreated animals. Histological and proteomic analyses were performed to elucidate the safety and efficacy of these carriers, showing an absence of systemic toxicity and a restored neural environment in treated responders. In the treated non-responders, proteomic analysis revealed competing mechanisms of pro-apoptotic and drug-resistant activity. This bacterial carrier opens a versatile avenue to overcome diffusion barriers in glioblastoma by virtue of its active motility in extracellular space and can lead to tailored therapies via tumor-specific expression of tumoricidal proteins.

  16. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    components. These substances may both mediate and stabilize the bacterial biofilm. Finally, several adhesive structures were examined, and a novel physiological biofilm phenotype in E.coli biofilms was characterized, namely cell chain formation. The autotransporter protein, antigen 43, was implicated...

  17. Bacterial lipases

    OpenAIRE

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, meaning a sharp increase in lipase activity observed when the substrate starts to form an emulsion, thereby presenting to the enzyme an interfacial area. As a consequence, the kinetics of a lipase rea...

  18. Versatile transmission ellipsometry to study linear ferrofluid magneto-optics

    NARCIS (Netherlands)

    Kooij, Ernst S.; Galca, A.C.; Poelsema, Bene

    2006-01-01

    Linear birefringence and dichroism of magnetite ferrofluids are studied simultaneously using spectroscopic ellipsometry in transmission mode. It is shown that this versatile technique enables highly accurate characterisation of magneto-optical phenomena. Magnetic field-dependent linear birefringence

  19. A versatile hardware platform for brain computer interfaces.

    Science.gov (United States)

    Garcia, Pablo A; Haberman, Marcelo; Spinelli, Enrique M

    2010-01-01

    This article presents the development of a versatile hardware platform for brain computer interfaces (BCI). The aim of this work is to produce a small, autonomous and configurable BCI platform adaptable to the user's needs.

  20. Electrospun nanofibers as versatile interfaces for efficient gene delivery

    National Research Council Canada - National Science Library

    Lee, Slgirim; Jin, Gyuhyung; Jang, Jae-Hyung

    2014-01-01

    The integration of gene delivery technologies with electrospun nanofibers is a versatile strategy to increase the potential of gene therapy as a key platform technology that can be readily utilized...

  1. Antigen 43-mediated autotransporter display, a versatile bacterial cell surface presentation system

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Hasman, Henrik; Schembri, Mark

    2002-01-01

    to the outer membrane and secretion through the cell envelope is contained within the protein itself. Ag43 consists of two subunits (alpha and beta), where the beta-subunit forms an integral outer membrane translocator to which the alpha-subunit is noncovalently attached. The simplicity of the Ag43 system...... makes it ideally suited as a surface display scaffold. Here we demonstrate that the Ag43 alpha-module can accommodate and display correctly folded inserts and has the ability to display entire functional protein domains, exemplified by the FimH lectin domain. The presence of heterologous cysteine...... bridges does not interfere with surface display, and Ag43 chimeras are correctly processed into alpha- and beta-modules, offering optional and easy release of the chimeric alpha-subunits. Furthermore, Ag43 can be displayed in many gram-negative bacteria. This feature is exploited for display of our...

  2. Advanced bacterial polyhydroxyalkanoates: towards a versatile and sustainable platform for unnatural tailor-made polyesters.

    Science.gov (United States)

    Park, Si Jae; Kim, Tae Wan; Kim, Min Kyung; Lee, Sang Yup; Lim, Sung-Chul

    2012-01-01

    Polyhydroxyalkanoates (PHAs) are biopolyesters that generally consist of 3-, 4-, 5-, and 6-hydroxycarboxylic acids, which are accumulated as carbon and energy storage materials in many bacteria in limited growth conditions with excess carbon sources. Due to the diverse substrate specificities of PHA synthases, the key enzymes for PHA biosynthesis, PHAs with different material properties have been synthesized by incorporating different monomer components with differing compositions. Also, engineering PHA synthases using in vitro-directed evolution and site-directed mutagenesis facilitates the synthesis of PHA copolymers with novel material properties by broadening the spectrum of monomers available for PHA biosynthesis. Based on the understanding of metabolism of PHA biosynthesis, recombinant bacteria have been engineered to produce different types of PHAs by expressing heterologous PHA biosynthesis genes, and by creating and enhancing the metabolic pathways to efficiently generate precursors for PHA monomers. Recently, the PHA biosynthesis system has been expanded to produce unnatural biopolyesters containing 2-hydroxyacid monomers such as glycolate, lactate, and 2-hydroxybutyrate by employing natural and engineered PHA synthases. Using this system, polylactic acid (PLA), one of the major commercially-available bioplastics, can be synthesized from renewable resources by direct fermentation of recombinant bacteria. In this review, we discuss recent advances in the development of the PHA biosynthesis system as a platform for tailor-made polyesters with novel material properties. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. BACTERIAL PLASMIDS

    Directory of Open Access Journals (Sweden)

    Marina Dinic

    2007-12-01

    Full Text Available Plasmids, extrachromosomal DNA, were identified in bacteria pertaining to family of Enterobacteriacae for the very first time. After that, they were discovered in almost every single observed strain. The structure of plasmids is made of circular double chain DNA molecules which are replicated autonomously in a host cell. Their length may vary from few up to several hundred kilobase (kb. Among the bacteria, plasmids are mostly transferred horizontally by conjugation process. Plasmid replication process can be divided into three stages: initiation, elongation, and termination. The process involves DNA helicase I, DNA gyrase, DNA polymerase III, endonuclease, and ligase.Plasmids contain genes essential for plasmid function and their preservation in a host cell (the beginning and the control of replication. Some of them possess genes whichcontrol plasmid stability. There is a common opinion that plasmids are unnecessary fora growth of bacterial population and their vital functions; thus, in many cases they can be taken up or kicked out with no lethal effects to a plasmid host cell. However,there are numerous biological functions of bacteria related to plasmids. Plasmids identification and classification are based upon their genetic features which are presented permanently in all of them, and these are: abilities to preserve themselves in a host cell and to control a replication process. In this way, plasmids classification among incompatibility groups is performed. The method of replicon typing, which is based on genotype and not on phenotype characteristics, has the same results as in compatibility grouping.

  4. Light scattering study of zinc oxide nanoparticles for the application of its anti-bacterial property

    Directory of Open Access Journals (Sweden)

    S. Roy

    2011-09-01

    Full Text Available Investigations on the anti-bacterial activity of ZnO nanoparticles on Staphylococcus aureus were made by using bio-technical method. Light scattering properties of these particles were studied as a function of scattering angle by using a versatile laboratory light scattering setup in order to find the scattering profile of ZnO nanoparticles and also the mode of action of these particles on bacterial property.

  5. Versatile Hydrogen-Hydrogen Bond with a Difference

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 6. Versatile Hydrogen-Hydrogen Bond with a Difference. A G Samuelson. Research News Volume 1 Issue 6 June 1996 pp 87-89. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/06/0087-0089 ...

  6. Flexible macrocycles as versatile supports for catalytically active metal clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, JD; Gagnon, KJ; Teat, SJ; McIntosh, RD

    2016-02-12

    Here we present three structurally diverse clusters stabilised by the same macrocyclic polyphenol; t-butylcalix[8]arene. This work demonstrates the range of conformations the flexible ligand is capable of adopting, highlighting its versatility in metal coordination. In addition, a Ti complex displays activity for the ring-opening polymerisation of lactide

  7. A versatile route to benzodiazocine and spiropyran derivatives ...

    Indian Academy of Sciences (India)

    125, No. 3, May 2013, pp. 517–524. c Indian Academy of Sciences. A versatile route to benzodiazocine and spiropyran derivatives through chalcones. JOHNSON GEORGEa, SAURABH SINGHa,. RAHUL JOSHIa and RAMCHAND T PARDASANIb,∗. aDepartment of Chemistry, University of Rajasthan, Jaipur 302 055, India.

  8. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    African Journals Online (AJOL)

    A Versatile Alternative when Reverse Sural Artery Flap is. Not Feasible. Samuel A. Ademola, Afieharo I. Michael, Femi .... flaps that were raised in the patient and the logistics of limb positioning after application of external fixators for bone ... Financial support and sponsorship. Nil. Conflicts of interest. There are no conflicts of ...

  9. Soybean ( Glycine max ) as a versatile biocatalyst for organic ...

    African Journals Online (AJOL)

    Soybean ( Glycine max ) as a versatile biocatalyst for organic synthesis. ... Most of the obtained alcohols have commercial value as cosmetic fragrances. Although, the enzymes present in soybean (reductase/lipase) has not been defined, the reaction is an important route for the preparation of pure alcohols and carboxylic ...

  10. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    African Journals Online (AJOL)

    Reverse sural artery fasciocutaneous flap has become a workhorse for the reconstruction of distal leg soft ... A Versatile Alternative when Reverse Sural Artery Flap is. Not Feasible. Samuel A. Ademola, Afieharo I. .... flaps that were raised in the patient and the logistics of limb positioning after application of external fixators ...

  11. Versatile Desktop Experiment Module (DEMo) on Heat Transfer

    Science.gov (United States)

    Minerick, Adrienne R.

    2010-01-01

    This paper outlines a new Desktop Experiment Module (DEMo) engineered for a chemical engineering junior-level Heat Transfer course. This new DEMo learning tool is versatile, fairly inexpensive, and portable such that it can be positioned on student desks throughout a classroom. The DEMo system can illustrate conduction of various materials,…

  12. Versatile Supramolecular Gene Vector Based on Host-Guest Interaction

    NARCIS (Netherlands)

    Liu, Jia; Hennink, Wim E.; Van Steenbergen, Mies J.; Zhuo, Renxi; Jiang, Xulin

    2016-01-01

    It is a great challenge to arrange multiple functional components into one gene vector system to overcome the extra- and intracellular obstacles for gene therapy. In this study, we developed a supramolecular approach for constructing a versatile gene delivery system composed of adamantyl-terminated

  13. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation...

  14. Environmental versatility promotes modularity in genome-scale metabolic networks.

    Science.gov (United States)

    Samal, Areejit; Wagner, Andreas; Martin, Olivier C

    2011-08-24

    The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chemical environments. For such networks, we define a network module as a maximal set of reactions that are fully coupled, i.e., whose fluxes can only vary in fixed proportions. This definition overcomes limitations of purely graph based analyses of metabolism by exploiting the functional links between reactions. We call a metabolic network viable in a given chemical environment if it can synthesize all of an organism's biomass compounds from nutrients in this environment. An organism's metabolism is highly versatile if it can sustain life in many different chemical environments. We here ask whether versatility affects the modularity of metabolic networks. Using recently developed techniques to randomly sample large numbers of viable metabolic networks from a vast space of metabolic networks, we use flux balance analysis to study in silico metabolic networks that differ in their versatility. We find that highly versatile networks are also highly modular. They contain more modules and more reactions that are organized into modules. Most or all reactions in a module are associated with the same biochemical pathways. Modules that arise in highly versatile networks generally involve reactions that process nutrients or closely related chemicals. We also observe that the metabolism of E. coli is significantly more modular than even our most versatile networks. Our work shows that modularity in metabolic networks can be a by-product of functional constraints, e.g., the need to sustain life in multiple

  15. Environmental versatility promotes modularity in genome-scale metabolic networks

    Science.gov (United States)

    2011-01-01

    Background The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chemical environments. For such networks, we define a network module as a maximal set of reactions that are fully coupled, i.e., whose fluxes can only vary in fixed proportions. This definition overcomes limitations of purely graph based analyses of metabolism by exploiting the functional links between reactions. We call a metabolic network viable in a given chemical environment if it can synthesize all of an organism's biomass compounds from nutrients in this environment. An organism's metabolism is highly versatile if it can sustain life in many different chemical environments. We here ask whether versatility affects the modularity of metabolic networks. Results Using recently developed techniques to randomly sample large numbers of viable metabolic networks from a vast space of metabolic networks, we use flux balance analysis to study in silico metabolic networks that differ in their versatility. We find that highly versatile networks are also highly modular. They contain more modules and more reactions that are organized into modules. Most or all reactions in a module are associated with the same biochemical pathways. Modules that arise in highly versatile networks generally involve reactions that process nutrients or closely related chemicals. We also observe that the metabolism of E. coli is significantly more modular than even our most versatile networks. Conclusions Our work shows that modularity in metabolic networks can be a by-product of functional constraints, e.g., the need to

  16. Environmental versatility promotes modularity in genome-scale metabolic networks

    Directory of Open Access Journals (Sweden)

    Wagner Andreas

    2011-08-01

    Full Text Available Abstract Background The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chemical environments. For such networks, we define a network module as a maximal set of reactions that are fully coupled, i.e., whose fluxes can only vary in fixed proportions. This definition overcomes limitations of purely graph based analyses of metabolism by exploiting the functional links between reactions. We call a metabolic network viable in a given chemical environment if it can synthesize all of an organism's biomass compounds from nutrients in this environment. An organism's metabolism is highly versatile if it can sustain life in many different chemical environments. We here ask whether versatility affects the modularity of metabolic networks. Results Using recently developed techniques to randomly sample large numbers of viable metabolic networks from a vast space of metabolic networks, we use flux balance analysis to study in silico metabolic networks that differ in their versatility. We find that highly versatile networks are also highly modular. They contain more modules and more reactions that are organized into modules. Most or all reactions in a module are associated with the same biochemical pathways. Modules that arise in highly versatile networks generally involve reactions that process nutrients or closely related chemicals. We also observe that the metabolism of E. coli is significantly more modular than even our most versatile networks. Conclusions Our work shows that modularity in metabolic networks can be a by-product of functional

  17. A Resource Allocation Trade-Off between Virulence and Proliferation Drives Metabolic Versatility in the Plant Pathogen Ralstonia solanacearum.

    Directory of Open Access Journals (Sweden)

    Rémi Peyraud

    2016-10-01

    Full Text Available Bacterial pathogenicity relies on a proficient metabolism and there is increasing evidence that metabolic adaptation to exploit host resources is a key property of infectious organisms. In many cases, colonization by the pathogen also implies an intensive multiplication and the necessity to produce a large array of virulence factors, which may represent a significant cost for the pathogen. We describe here the existence of a resource allocation trade-off mechanism in the plant pathogen R. solanacearum. We generated a genome-scale reconstruction of the metabolic network of R. solanacearum, together with a macromolecule network module accounting for the production and secretion of hundreds of virulence determinants. By using a combination of constraint-based modeling and metabolic flux analyses, we quantified the metabolic cost for production of exopolysaccharides, which are critical for disease symptom production, and other virulence factors. We demonstrated that this trade-off between virulence factor production and bacterial proliferation is controlled by the quorum-sensing-dependent regulatory protein PhcA. A phcA mutant is avirulent but has a better growth rate than the wild-type strain. Moreover, a phcA mutant has an expanded metabolic versatility, being able to metabolize 17 substrates more than the wild-type. Model predictions indicate that metabolic pathways are optimally oriented towards proliferation in a phcA mutant and we show that this enhanced metabolic versatility in phcA mutants is to a large extent a consequence of not paying the cost for virulence. This analysis allowed identifying candidate metabolic substrates having a substantial impact on bacterial growth during infection. Interestingly, the substrates supporting well both production of virulence factors and growth are those found in higher amount within the plant host. These findings also provide an explanatory basis to the well-known emergence of avirulent variants in R

  18. Versatile module for experiments with focussing neutron guides

    Energy Technology Data Exchange (ETDEWEB)

    Adams, T.; Pfleiderer, C.; Böni, P. [Physik-Department, Technische Universität München, D-85748 Garching (Germany); Brandl, G.; Chacon, A.; Wagner, J. N.; Rahn, M.; Mühlbauer, S.; Georgii, R. [Physik-Department, Technische Universität München, D-85748 Garching (Germany); Heinz Maier-Leibnitz Zentrum, FRM II, Technische Universität München, D-85748 Garching (Germany)

    2014-09-22

    We report the development of a versatile module that permits fast and reliable use of focussing neutron guides under varying scattering angles. A simple procedure for setting up the module and neutron guides is illustrated by typical intensity patterns to highlight operational aspects as well as typical parasitic artefacts. Combining a high-precision alignment table with separate housings for the neutron guides on kinematic mounts, the change-over between neutron guides with different focussing characteristics requires no readjustments of the experimental setup. Exploiting substantial gain factors, we demonstrate the performance of this versatile neutron scattering module in a study of the effects of uniaxial stress on the domain populations in the transverse spin density wave phase of single crystal Cr.

  19. Research and development of a versatile portable speech prosthesis

    Science.gov (United States)

    1981-01-01

    The Versatile Portable Speech Prosthesis (VPSP), a synthetic speech output communication aid for non-speaking people is described. It was intended initially for severely physically limited people with cerebral palsy who are in electric wheelchairs. Hence, it was designed to be placed on a wheelchair and powered from a wheelchair battery. It can easily be separated from the wheelchair. The VPSP is versatile because it is designed to accept any means of single switch, multiple switch, or keyboard control which physically limited people have the ability to use. It is portable because it is mounted on and can go with the electric wheelchair. It is a speech prosthesis, obviously, because it speaks with a synthetic voice for people unable to speak with their own voices. Both hardware and software are described.

  20. Electrospun nanofibers as versatile interfaces for efficient gene delivery

    OpenAIRE

    Lee, Slgirim; Jin, Gyuhyung; Jang, Jae-Hyung

    2014-01-01

    The integration of gene delivery technologies with electrospun nanofibers is a versatile strategy to increase the potential of gene therapy as a key platform technology that can be readily utilized for numerous biomedical applications, including cancer therapy, stem cell therapy, and tissue engineering. As a spatial template for gene delivery, electrospun nanofibers possess highly advantageous characteristics, such as their ease of production, their ECM-analogue nature, the broad range of cho...

  1. Connecting leadership and learning: Do versatile learners make connective leaders?

    OpenAIRE

    Robinson, Jill L.

    2016-01-01

    Recent failures in leadership, suggest that creating better-quality leadership development programs is critical. In moving from theory to practice, this paper examined the relationship between learning style and leadership style which may enable us to move away from one-size-fits-all leadership development programs. Utilizing Kolb’s Experiential Learning Model and Connective Leadership theory, approximately 3600 college students were analyzed to discover whether versatility in learning styles...

  2. Connecting Leadership and Learning: Do Versatile Learners make Connective Leaders?

    OpenAIRE

    Jill L. Robinson

    2016-01-01

    Abstract Recent failures in leadership, suggest that creating better-quality leadership development programs is critical. In moving from theory to practice, this paper examined the relationship between learning style and leadership style which may enable us to move away from one-size-fits-all leadership development programs. Utilizing Kolb’s Experiential Learning Model and Connective Leadership theory, approximately 3600 college students were analyzed to discover whether versatility in le...

  3. Versatile composite resins simplifying the practice of restorative dentistry.

    Science.gov (United States)

    Margeas, Robert

    2014-01-01

    After decades of technical development and refinement, composite resins continue to simplify the practice of restorative dentistry, offering clinicians versatility, predictability, and enhanced physical properties. With a wide range of products available today, composite resins are a reliable, conservative, multi-functional restorative material option. As manufacturers strive to improve such properties as compression strength, flexural strength, elastic modulus, coefficient of thermal expansion, water sorption, and wear resistance, several classification systems of composite resins have been developed.

  4. A Combinatorial Auction among Versatile Experts and Amateurs

    Science.gov (United States)

    Ito, Takayuki; Yokoo, Makoto; Matsubara, Shigeo

    Auctions have become an integral part of electronic commerce and a promising field for applying multi-agent technologies. Correctly judging the quality of auctioned goods is often difficult for amateurs, in particular, in Internet auctions. However, experts can correctly judge the quality of goods. In this situation, it is difficult to make experts tell the truth and attain an efficient allocation, since experts have a clear advantage over amateurs and they would not reveal their valuable information without some reward. In our previous work, we have succeeded in developing such auction protocols under the following two cases: (1) the case of a single-unit auction among experts and amateurs, and (2) the case of a combinatorial auction among single-skilled experts and amateurs. In this paper, we focus on versatile experts. Versatile experts have an interest in, and expert knowledge on the qualities of several goods. In the case of versatile experts, there would be several problems, e.g., free riding problems, if we simply extended the previous VCG-style auction protocol. Thus, in this paper, we employ PORF (price-oriented, rationing-free) protocol for designing our new protocol to realize a strategy-proof auction protocol for experts. In the protocol, the dominant strategy for experts is truth-telling. Also, for amateurs, truth-telling is the best response when two or more experts select the dominant strategy. Furthermore, the protocol is false-name-proof.

  5. Connecting Leadership and Learning: Do Versatile Learners make Connective Leaders?

    Directory of Open Access Journals (Sweden)

    Jill L. Robinson

    2016-03-01

    Full Text Available Abstract Recent failures in leadership, suggest that creating better-quality leadership development programs is critical. In moving from theory to practice, this paper examined the relationship between learning style and leadership style which may enable us to move away from one-size-fits-all leadership development programs. Utilizing Kolb’s Experiential Learning Model and Connective Leadership theory, approximately 3600 college students were analyzed to discover whether versatility in learning styles translates into versatility in leadership styles. One group of versatile learners reported using a wider range of leadership styles suggesting that learning flexibility may transfer to leadership flexibility. Surprisingly, learners of all types reported utilizing Power and Intrinsic styles of leadership above all others. Implications for leadership development include considering individual differences when crafting leadership programs, matching learning styles to leader training, and the need to move beyond one set of leadership behaviors to increase flexibility in dealing with complex situations. Using a large sample rarely seen in management studies, this paper makes key contributions to the literature. 

  6. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... baby Common illnesses Family health & safety Complications & Loss Pregnancy complications Preterm labor & premature birth The newborn intensive care ... Point, NY 10980 Close X Home > Complications & Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy ...

  7. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  8. Design of a Compact and Versatile Bench Scale Tubular Reactor

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2009-06-01

    Full Text Available A compact and versatile laboratory tubular reactor has been designed and fabricated keeping in view of reducing capital cost and minimising energy consumption for gas/vapor-phase heterogeneous catalytic reactions. The reactor is consisted of two coaxial corning glass tubes with a helical coil of glass tube in between the coaxial tubes serving as vaporiser and pre-heater, the catalyst bed is in the inner tube. A schematic diagram of the reactor with detailed dimensions and working principles are described. The attractive feature of the reactor is that the vaporiser, pre-heater and fixed bed reactor are merged in a single compact unit. Thus, the unit minimises separate vaporiser and pre-heater, also avoids separate furnaces used for them and eliminate auxiliary instrumentation such as temperature controller etc. To demonstrate the system operation and illustrate the key features, catalyst screening data and the efficient collection of complete, and accurate intrinsic kinetic data are provided for oxidation of CO over copper chromite catalyst. CO oxidation is an important reaction for auto-exhaust pollution control. The suitability of the versatile nature of the reactor has been ascertained for catalytic reactions where either volatile or vaporizable feeds can be introduced to the reaction zone, e.g. oxidation of iso-octane, reduction of nitric oxide, dehydrogenation of methanol, ethanol and iso-propanol, hydrogenation of nitrobenzene to aniline, etc. Copyright (c 2009 by BCREC. All Rights reserved.[Received: 10 February 2009, Accepted: 9 May 2009][How to Cite: R. Prasad, G. Rattan. (2009. Design of a Compact and Versatile Bench Scale Tubular Reactor. Bulletin of Chemical Reaction Engineering and Catalysis, 4(1: 5-9.  doi:10.9767/bcrec.4.1.1250.5-9][How to Link/ DOI: http://dx.doi.org/10.9767/bcrec.4.1.1250.5-9

  9. Inactivation of a Pleurotus ostreatus versatile peroxidase-encoding gene (mnp2) results in reduced lignin degradation.

    Science.gov (United States)

    Salame, Tomer M; Knop, Doriv; Levinson, Dana; Mabjeesh, Sameer J; Yarden, Oded; Hadar, Yitzhak

    2014-01-01

    Lignin biodegradation by white-rot fungi is pivotal to the earth's carbon cycle. Manganese peroxidases (MnPs), the most common extracellular ligninolytic peroxidases produced by white-rot fungi, are considered key in ligninolysis. Pleurotus ostreatus, the oyster mushroom, is a preferential lignin degrader occupying niches rich in lignocellulose such as decaying trees. Here, we provide direct, genetically based proof for the functional significance of MnP to P. ostreatus ligninolytic capacity under conditions mimicking its natural habitat. When grown on a natural lignocellulosic substrate of cotton stalks under solid-state culture conditions, gene and isoenzyme expression profiles of its short MnP and versatile peroxidase (VP)-encoding gene family revealed that mnp2 was predominately expressed. mnp2, encoding the versatile short MnP isoenzyme 2 was disrupted. Inactivation of mnp2 resulted in three interrelated phenotypes, relative to the wild-type strain: (i) reduction of 14% and 36% in lignin mineralization of stalks non-amended and amended with Mn(2+), respectively; (ii) marked reduction of the bioconverted lignocellulose sensitivity to subsequent bacterial hydrolyses; and (iii) decrease in fungal respiration rate. These results may serve as the basis to clarify the roles of the various types of fungal MnPs and VPs in their contribution to white-rot decay of wood and lignocellulose in various ecosystems. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Versatile transmission ellipsometry to study linear ferrofluid magneto-optics.

    Science.gov (United States)

    Kooij, E S; Gâlcă, A C; Poelsema, B

    2006-12-01

    Linear birefringence and dichroism of magnetite ferrofluids are studied simultaneously using spectroscopic ellipsometry in transmission mode. It is shown that this versatile technique enables highly accurate characterisation of magneto-optical phenomena. Magnetic field-dependent linear birefringence and dichroism as well as the spectral dependence are shown to be in line with previous results. Despite the qualitative agreement with established models for magneto-optical phenomena, these fail to provide an accurate, quantitative description of our experimental results using the bulk dielectric function of magnetite. We discuss the results in relation to these models, and indicate how the modified dielectric function of the magnetite nanoparticles can be obtained.

  11. Versatile supramolecular organogel with outstanding stability toward aqueous interfaces.

    Science.gov (United States)

    Bonifazi, Evelyn L; Edelsztein, Valeria C; Menéndez, Guillermo O; Samaniego López, Cecilia; Spagnuolo, Carla C; Di Chenna, Pablo H

    2014-06-25

    In this communication, we report on a novel and versatile low-molecular-weight organogelator. The methanolic gel exhibits an exceptional water-enhanced stability as evidenced by a 30 °C increase in Tg with up to 10%v/v of water. This atypical property not observed with other solvents makes of this supramolecular gel a highly stable matrix compatible with aqueous interfaces. As a proof of principle we present the sensing performance of a symmetric tricarbocyanine fluorophore bearing a Zn(II)chelator unit. The system retained its remarkable physical integrity for a long period of time opening new possibilities for other organic-aqueous interface applications.

  12. A Versatile Glass Processor for High-Performance Photonic Platforms

    Science.gov (United States)

    2015-12-08

    SECURITY CLASSIFICATION OF: With the DURIP fund, we acquire a glass processing station to enhance our capabilities to achieve ultra-high performance...funded by PECASE (supported by DoD-ARO under the contract/grant number W911NF-12-1-0026) on high performance optical sensors. The multipurpose glass ...Distribution Unlimited UU UU UU UU 08-12-2016 1-Aug-2014 31-Jul-2015 Final Report: A Versatile Glass Processor for High-Performance Photonic Platforms The views

  13. CORRTEX: a compact and versatile system for time domain reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Deupree, R.G.; Eilers, D.D.; McKown, T.O.; Storey, W.H.

    1981-01-01

    The CORRTEX (COntinuous Reflectometry for Radius versus Time EXperiments) system was designed to be an adaptable and versatile unit for performing time domain reflectometry (TDR). The system consists of a coaxial cable, a digital TDR, which uses a Motorola 6800 microprocessor, a power source or battery pack, and an output terminal or recording driver. Desirable criteria for the system are discussed as well as the operation of the CORRTEX system. The types of present applications of the CORRTEX system are summarized and data presented.

  14. Read-only holographic versatile disc system using laser diode

    Science.gov (United States)

    Horimai, Hideyoshi; Tan, Xiaodi

    2006-05-01

    A Read-only Holographic Versatile Disc (HVD-ROM) system, using a laser diode for high capacity and high data transfer rates storage system, is proposed. With the collinear technologies' unique configuration the optical pickup can be designed as small as a DVD's, and can be placed on one side of the disc. With the HVD's special structure, the system can servo the focus/tracking and locate reading/writing address. The experiments and theoretical studies suggest that a laser diode is very suitable as a light source of our HVD-ROM system.

  15. The Q-System: A Versatile Expression System for Drosophila.

    Science.gov (United States)

    Riabinina, Olena; Potter, Christopher J

    2016-01-01

    Binary expression systems are flexible and versatile genetic tools in Drosophila. The Q-system is a recently developed repressible binary expression system that offers new possibilities for transgene expression and genetic manipulations. In this review chapter, we focus on current state-of-the-art Q-system tools and reagents. We also discuss in vivo applications of the Q-system, together with GAL4/UAS and LexA/LexAop systems, for simultaneous expression of multiple effectors, intersectional labeling, and clonal analysis.

  16. Versatile test rig for the evaluation of thermionic electron guns

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, H.; Cleaver, J.R.A. (Cambridge Univ. (UK). Dept. of Engineering); Catto, C.J.D. (Cambridge Sanning Ltd. (UK)); Kanitkar, P.L. (Poona Univ. (India). Dept. of Physics); Smith, D.J. (Cambridge Univ. (UK). High Resolution Electron Microscope)

    1982-12-01

    Measurements of the brightness and the electron energy distribution for high-performance electron guns for electron-optical instruments must take account of the small effective size of the electron source and the directional dependence of the emission from it. A versatile electron gun test rig has been developed to enable measurements to be made under realistic operating conditions. Energy distribution can be determined with a hemispherical cup retarding-field analyser, and brightness can be measured at up to 100 kV by both two-aperture and crossover-projection methods. Some measured characteristics of lanthanum hexaboride cathodes are given, with measurements of conventional tungsten cathodes for comparison.

  17. Atomic force microscopy studies of bioprocess engineering surfaces - imaging, interactions and mechanical properties mediating bacterial adhesion.

    Science.gov (United States)

    James, Sean A; Hilal, Nidal; Wright, Chris J

    2017-07-01

    The detrimental effect of bacterial biofilms on process engineering surfaces is well documented. Thus, interest in the early stages of bacterial biofilm formation; in particular bacterial adhesion and the production of anti-fouling coatings has grown exponentially as a field. During this time, Atomic force microscopy (AFM) has emerged as a critical tool for the evaluation of bacterial adhesion. Due to its versatility AFM offers not only insight into the topographical landscape and mechanical properties of the engineering surfaces, but elucidates, through direct quantification the topographical and biomechnical properties of the foulants The aim of this review is to collate the current research on bacterial adhesion, both theoretical and practical, and outline how AFM as a technique is uniquely equipped to provide further insight into the nanoscale world at the bioprocess engineering surface. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Versatile aggressive mimicry of cicadas by an Australian predatory katydid.

    Directory of Open Access Journals (Sweden)

    David C Marshall

    Full Text Available BACKGROUND: In aggressive mimicry, a predator or parasite imitates a signal of another species in order to exploit the recipient of the signal. Some of the most remarkable examples of aggressive mimicry involve exploitation of a complex signal-response system by an unrelated predator species. METHODOLOGY/PRINCIPAL FINDINGS: We have found that predatory Chlorobalius leucoviridis katydids (Orthoptera: Tettigoniidae can attract male cicadas (Hemiptera: Cicadidae by imitating the species-specific wing-flick replies of sexually receptive female cicadas. This aggressive mimicry is accomplished both acoustically, with tegminal clicks, and visually, with synchronized body jerks. Remarkably, the katydids respond effectively to a variety of complex, species-specific Cicadettini songs, including songs of many cicada species that the predator has never encountered. CONCLUSIONS/SIGNIFICANCE: We propose that the versatility of aggressive mimicry in C. leucoviridis is accomplished by exploiting general design elements common to the songs of many acoustically signaling insects that use duets in pair-formation. Consideration of the mechanism of versatile mimicry in C. leucoviridis may illuminate processes driving the evolution of insect acoustic signals, which play a central role in reproductive isolation of populations and the formation of species.

  19. Iron: a versatile element to produce materials for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Ana Paula C.; Araujo, Maria H.; Oliveira, Luiz C.A.; Moura, Flavia C.C.; Lago, Rochel M., E-mail: rochel@ufmg.br, E-mail: anapct@ufmg.br [Departamento de Quimica, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Tristao, Juliana C. [Universidade Federal de Vicosa, Florestal, MG (Brazil); Ardisson, Jose D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Fisica Aplicada; Amorim, Camila C., E-mail: juliana@ufv.br [Departamento de Engenharia Sanitaria e Ambiental, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

    2012-09-15

    Iron is a versatile element forming several phases with different oxidation states and {sup s}tructures, such as Fe{sup 0}, FeO, Fe{sub 3}O{sub 4}, {gamma}-Fe{sub 2}O{sub 3}, {alpha}-Fe{sub 2}O{sub 3} and FeOOH. All these phases have unique physicochemical properties which can be used for different applications. In this work, it is described the use of different iron compounds, synthetic and also from natural and waste sources, in environmental and technological applications. Two main research areas are described. The first one is related to strategies to increase the reactivity of Fe phases, mainly by the formation of Fe{sup 0}/iron oxide composites and by the introduction of new metals in the iron oxide structure to promote new surface reactions. The second area is the use of the magnetic properties of some iron phases to produce versatile magnetic materials with focus in adsorption, catalysis and emulsions. (author)

  20. Versatile equipment for mechanical testing of active materials

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, Johannes; Heimgartner, Peter

    2005-01-01

    At the Paul Scherrer Institute (PSI) 3 different project groups presently perform aging research on active materials. The research fields are fusion, high neutron flux targets and LWR relevant components. Up to now mechanical testing has been performed with small, low dose rate samples behind local shielding, not appropriate for highly activated material. To overcome this situation, a cell concept for active mechanical testing was elaborated and has been erected in PSI's Hotlab. It consists of 4 shielded cells. 3 connected cells are versatile and independently operable for highly beta/gamma active samples. One cell is an alpha/beta/gamma-box which will be realized in a second phase. This paper presents the versatility especially of the beta/gamma-cells: The different user groups perform experiments in these cells, whereas different machines can be placed into the cells. As consequence of the need of heavily shielded cell doors, a special strengthening and levelling of the floor has been required. In all cells the relevant media are installed. Besides the performance of the cells, the project progress as the difficulties and their solutions are described. (Author)

  1. Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Brullot, W., E-mail: ward.brullot@fys.kuleuven.be [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium); Reddy, N.K. [Department of Chemical Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 46, 3001 Heverlee, Leuven (Belgium); Wouters, J.; Valev, V.K.; Goderis, B. [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium); Vermant, J. [Department of Chemical Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 46, 3001 Heverlee, Leuven (Belgium); Verbiest, T. [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium)

    2012-06-15

    Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles were obtained by a facile protocol and thoroughly characterized. Superparamagnetic iron oxide nanoparticles synthesized using a modified forced hydrolysis method were functionalized with polyethylene glycol silane (PEG silane), precipitated and dried. These functionalized particles are dispersable in a range of solvents and concentrations depending on the desired properties. Examples of tunable properties are magnetic behavior, optical and magneto-optical response, thermal features and rheological behavior. As such, PEG silane functionalized particles represent a platform for the development of new materials that have broad applicability in e.g. biomedical, industrial or photonic environments. Magnetic, optical, magneto-optical, thermal and rheological properties of several ferrofluids based on PEG coated particles with different concentrations of particles dispersed in low molecular mass polyethylene glycol were investigated, establishing the applicability of such materials. - Highlights: Black-Right-Pointing-Pointer Ferrofluids based on polyethylene glycol coated iron oxide nanoparticles. Black-Right-Pointing-Pointer Magnetic, optical, magneto-optical, thermal and rheological characterization of ferrofluids. Black-Right-Pointing-Pointer Tunable properties of versatile polyethylene glycol stabilized ferrofluids.

  2. A versatile patterning process based on easily soluble sacrificial bilayers

    Science.gov (United States)

    Harada, Takayuki; Tsukazaki, Atsushi

    2017-08-01

    Development of a microfabrication process is essential to embed fascinating physical properties of functional materials into mesoscopic devices. Different from well-investigated materials with established microfabrication process, newly-discovered materials often meet difficulty when scaling down into a mesoscopic size, because process damages cause serious deterioration of their functionalities. Here, we demonstrate a versatile lift-off method using a carefully designed sacrificial bilayer, composed of an easily soluble layer and a thermally stable rigid layer. In this method, the target films can be grown in optimum conditions, such as high temperature and high oxygen partial pressure, on the stable pre-patterned substrate with the inorganic sacrificial bilayer. After film deposition, measurable patterned devices can be obtained just by a short-time lift-off in a mild chemical solution. We carried out micron-scale patterning and electrical measurements by applying this technique to one of perovskite oxides, SrRuO3, and Fe-based chalcogenide superconductors, FeSe, both of which are incompatible with conventional photolithography and dry-etching processes. The demonstrated narrowest line width of 5 μm is successfully patterned with maintaining the almost identical properties of the pristine films, exemplifying that process damage is minimized. The demonstrated versatile patterning process expands the range of application of emerging functional materials in thin film devices.

  3. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  4. Bacterial polyhydroxybutyrate for electrospun fiber production.

    Science.gov (United States)

    Acevedo, Francisca; Villegas, Pamela; Urtuvia, Viviana; Hermosilla, Jeyson; Navia, Rodrigo; Seeger, Michael

    2017-08-16

    Nano- and microfibers obtained by electrospinning have attracted great attention due to its versatility and potential for applications in diverse technological fields. Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by microorganisms such as the bacterium Burkholderia xenovorans LB400. In particular, LB400 cells are capable to synthesize poly(3-hydroxybutyrate) (PHB) from glucose. The aim of this study was to produce and characterize electrospun fibers obtained from bacterial PHBs. Bacterial strain LB400 was grown in M9 minimal medium using xylose and mannitol (10gL(-1)) as the sole carbon sources and NH4Cl (1gL(-1)) as the sole nitrogen source. Biopolymer-based films obtained were used to produce fibers by electrospinning. Diameter and morphology of the microfibers were analyzed by scanning electron microscopy (SEM) and their thermogravimetric properties were investigated. Bead-free fibers using both PHBs were obtained with diameters of less than 3μm. The surface morphology of the microfibers based on PHBs obtained from both carbon sources was different, even though their thermogravimetric properties are similar. The results indicate that the carbon source may determine the fiber structure and properties. Further studies should be performed to analyze the physicochemical and mechanical properties of these PHB-based microfibers, which may open up novel applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. A versatile apparatus for two-dimensional atomtronic quantum simulation

    Science.gov (United States)

    Haase, T. A.; White, D. H.; Brown, D. J.; Herrera, I.; Hoogerland, M. D.

    2017-11-01

    We report on the implementation of a novel optical setup for generating high-resolution customizable potentials to address ultracold bosonic atoms in two dimensions. Two key features are developed for this purpose. The customizable potential is produced with a direct image of a spatial light modulator, conducted with an in-vacuum imaging system of high numerical aperture. Custom potentials are drawn over an area of 600 ×400 μ m with a resolution of 0.9 μm. The second development is a two-dimensional planar trap for atoms with an aspect ratio of 900 and spatial extent of Rayleigh range 1.6 × 1.6 mm, providing near-ballistic in-planar movement. We characterize the setup and present a brief catalog of experiments to highlight the versatility of the system.

  6. Algae biofuels: versatility for the future of bioenergy.

    Science.gov (United States)

    Jones, Carla S; Mayfield, Stephen P

    2012-06-01

    The world continues to increase its energy use, brought about by an expanding population and a desire for a greater standard of living. This energy use coupled with the realization of the impact of carbon dioxide on the climate, has led us to reanalyze the potential of plant-based biofuels. Of the potential sources of biofuels the most efficient producers of biomass are the photosynthetic microalgae and cyanobacteria. These versatile organisms can be used for the production of bioethanol, biodiesel, biohydrogen, and biogas. In fact, one of the most economic methods for algal biofuels production may be the combined biorefinery approach where multiple biofuels are produced from one biomass source. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Extraordinary phylogenetic diversity and metabolic versatility in aquifer sediment.

    Science.gov (United States)

    Castelle, Cindy J; Hug, Laura A; Wrighton, Kelly C; Thomas, Brian C; Williams, Kenneth H; Wu, Dongying; Tringe, Susannah G; Singer, Steven W; Eisen, Jonathan A; Banfield, Jillian F

    2013-01-01

    Microorganisms in the subsurface represent a substantial but poorly understood component of the Earth's biosphere. Subsurface environments are complex and difficult to characterize; thus, their microbiota have remained as a 'dark matter' of the carbon and other biogeochemical cycles. Here we deeply sequence two sediment-hosted microbial communities from an aquifer adjacent to the Colorado River, CO, USA. No single organism represents more than ~1% of either community. Remarkably, many bacteria and archaea in these communities are novel at the phylum level or belong to phyla lacking a sequenced representative. The dominant organism in deeper sediment, RBG-1, is a member of a new phylum. On the basis of its reconstructed complete genome, RBG-1 is metabolically versatile. Its wide respiration-based repertoire may enable it to respond to the fluctuating redox environment close to the water table. We document extraordinary microbial novelty and the importance of previously unknown lineages in sediment biogeochemical transformations.

  8. A small low-power networked and versatile sensor interface

    Science.gov (United States)

    Vincent, Peter S.; McMahon, Phillip J.; Muscat, Richard F.; Zeve, Ladislav; Wilson, Alan R.

    2007-01-01

    Defence Science and Technology Organisation (DSTO) has developed a low power RS485 sensor network that can be hardware configured at design time from a number of modules, depending on its final application. The core predesigned module includes network communications, microprocessor control and digital input/output. A number of analogue sensor interface modules can easily be added to this core. In addition, the software is also of modular design consisting of a set of core operating routines and a set of routines for controlling sensor operations that can be downloaded or upgraded in the field. Prime consideration in this development has been given to the need for small size, low weight, low power and versatility of operation. The hardware is based around the Texas Instruments MSP430® micro-controller. This paper will present some of the considerations leading to the design and examples of applications of the sensor network.

  9. Preparation of a Versatile Bifunctional Zeolite for Targeted Imaging Applications

    Science.gov (United States)

    Ndiege, Nicholas; Raidoo, Renugan; Schultz, Michael K.; Larsen, Sarah

    2011-01-01

    Bifunctional zeolite Y was prepared for use in targeted in vivo molecular imaging applications. The strategy involved functionalization of the external surface of zeolite Y with chloropropyltriethoxysilane followed by reaction with sodium azide to form azide-functionalized NaY, which is amenable to copper(1) catalyzed click chemistry. In this study, a model alkyne (4-pentyn-1-ol) was attached to the azide-terminated surface via click chemistry to demonstrate feasibility for attachment of molecular targeting vectors (e.g., peptides, aptamers) to the zeolite surface. The modified particle efficiently incorporates the imaging radioisotope gallium-68 (68Ga) into the pores of the azide-functionalized NaY zeolite to form a stable bifunctional molecular targeting vector. The result is a versatile “clickable” zeolite platform that can be tailored for future in vivo molecular targeting and imaging modalities. PMID:21306141

  10. A new versatile in-process monitoring system for milling

    CERN Document Server

    Ritou, Mathieu; Furet, Benoît; Hascoët, Jean-Yves

    2013-01-01

    Tool condition monitoring (TCM) systems can improve productivity and ensure workpiece quality, yet, there is a lack of reliable TCM solutions for small-batch or one-off manufacturing of industrial parts. TCM methods which include the characteristics of the cut seem to be particularly suitable for these demanding applications. In the first section of this paper, three process-based indicators have been retrieved from literature dealing with TCM. They are analysed using a cutting force model and experiments are carried out in industrial conditions. Specific transient cuttings encountered during the machining of the test part reveal the indicators to be unreliable. Consequently, in the second section, a versatile in-process monitoring method is suggested. Based on experiments carried out under a range of different cutting conditions, an adequate indicator is proposed: the relative radial eccentricity of the cutters is estimated at each instant and characterizes the tool state. It is then compared with the previo...

  11. Microscale Symmetrical Electroporator Array as a Versatile Molecular Delivery System

    Science.gov (United States)

    Ouyang, Mengxing; Hill, Winfield; Lee, Jung Hyun; Hur, Soojung Claire

    2017-03-01

    Successful developments of new therapeutic strategies often rely on the ability to deliver exogenous molecules into cytosol. We have developed a versatile on-chip vortex-assisted electroporation system, engineered to conduct sequential intracellular delivery of multiple molecules into various cell types at low voltage in a dosage-controlled manner. Micro-patterned planar electrodes permit substantial reduction in operational voltages and seamless integration with an existing microfluidic technology. Equipped with real-time process visualization functionality, the system enables on-chip optimization of electroporation parameters for cells with varying properties. Moreover, the system’s dosage control and multi-molecular delivery capabilities facilitate intracellular delivery of various molecules as a single agent or in combination and its utility in biological research has been demonstrated by conducting RNA interference assays. We envision the system to be a powerful tool, aiding a wide range of applications, requiring single-cell level co-administrations of multiple molecules with controlled dosages.

  12. A versatile high resolution scanning tunneling potentiometry implementation.

    Science.gov (United States)

    Druga, T; Wenderoth, M; Homoth, J; Schneider, M A; Ulbrich, R G

    2010-08-01

    We have developed a new scanning tunneling potentiometry technique which can-with only minor changes of the electronic setup-be easily added to any standard scanning tunneling microscope (STM). This extension can be combined with common STM techniques such as constant current imaging or scanning tunneling spectroscopy. It is capable of performing measurements of the electrochemical potential with microvolt resolution. Two examples demonstrate the versatile application. First of all, we have determined local variations of the electrochemical potential due to charge transport of biased samples down to angstrom length scales. Second, with tip and sample at different temperatures we investigated the locally varying thermovoltage occurring at the tunneling junction. Aside from its use in determining the chemical identity of substances at the sample surface our method provides a controlled way to eliminate the influence of laterally varying thermovoltages on low-bias constant current topographies.

  13. Twister ribozymes as highly versatile expression platforms for artificial riboswitches.

    Science.gov (United States)

    Felletti, Michele; Stifel, Julia; Wurmthaler, Lena A; Geiger, Sophie; Hartig, Jörg S

    2016-09-27

    The utilization of ribozyme-based synthetic switches in biotechnology has many advantages such as an increased robustness due to in cis regulation, small coding space and a high degree of modularity. The report of small endonucleolytic twister ribozymes provides new opportunities for the development of advanced tools for engineering synthetic genetic switches. Here we show that the twister ribozyme is distinguished as an outstandingly flexible expression platform, which in conjugation with three different aptamer domains, enables the construction of many different one- and two-input regulators of gene expression in both bacteria and yeast. Besides important implications in biotechnology and synthetic biology, the observed versatility in artificial genetic control set-ups hints at possible natural roles of this widespread ribozyme class.

  14. Preliminary Options Assessment of Versatile Irradiation Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ramazan Sonat [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-01-01

    The objective of this report is to summarize the work undertaken at INL from April 2016 to January 2017 and aimed at analyzing some options for designing and building a versatile test reactor; the scope of work was agreed upon with DOE-NE. Section 2 presents some results related to KNK II and PRISM Mod A. Section 3 presents some alternatives to the VCTR presented in [ ] as well as a neutronic parametric study to assess the minimum power requirement needed for a 235U metal fueled fast test reactor capable to generate a fast (>100 keV) flux of 4.0 x 1015 n /cm2-s at the test location. Section 4 presents some results regarding a fundamental characteristic of test reactors, namely displacement per atom (dpa) in test samples. Section 5 presents the INL assessment of the ANL fast test reactor design FASTER. Section 6 presents a summary.

  15. A versatile computer-controlled high-resolution LBIC system

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.; Fernandez-Lorenzo, C.; Poce-Fatou, J.A.; Alcantara, R. [Facultad de Ciencias, Cadiz (Spain). Dpto. de Quimica Fisica

    2004-07-01

    This paper presents the design of versatile equipment for obtaining laser-beam-induced current (LBIC) images which allows the study of large surfaces as well as conversion areas of a few micrometers. The modular optomechanical design enables the user to modify the size of the irradiation spot by simply changing the microscope objective used as focal lens, albeit within the limits set by the wavelength. The use of an appropriate calculation algorithm makes it possible to rely on a computerized system to adjust the distance at which the focusing lens must be placed with respect to the sample plane. The possibility of working at micrometer resolution allows one to obtain very significant information for the study of irregularities, manufacturing defects, impurities, grain boundaries, dislocations, recombination centers, etc. in photovoltaic wafers. (author)

  16. ggseqlogo: a versatile R package for drawing sequence logos.

    Science.gov (United States)

    Wagih, Omar

    2017-11-15

    Sequence logos have become a crucial visualization method for studying underlying sequence patterns in the genome. Despite this, there remains a scarcity of software packages that provide the versatility often required for such visualizations. ggseqlogo is an R package built on the ggplot2 package that aims to address this issue. ggseqlogo offers native illustration of publication-ready DNA, RNA and protein sequence logos in a highly customizable fashion with features including multi-logo plots, qualitative and quantitative colour schemes, annotation of logos and integration with other plots. The package is intuitive to use and seamlessly integrates into R analysis pipelines. ggseqlogo is released under the GNU licence and is freely available via CRAN-The Comprehensive R Archive Network https://cran.r-project.org/web/packages/ggseqlogo. A detailed tutorial can be found at https://omarwagih.github.io/ggseqlogo. wagih@ebi.ac.uk.

  17. Metagenome of a versatile chemolithoautotroph from expanding oceanic dead zones.

    Science.gov (United States)

    Walsh, David A; Zaikova, Elena; Howes, Charles G; Song, Young C; Wright, Jody J; Tringe, Susannah G; Tortell, Philippe D; Hallam, Steven J

    2009-10-23

    Oxygen minimum zones, also known as oceanic "dead zones," are widespread oceanographic features currently expanding because of global warming. Although inhospitable to metazoan life, they support a cryptic microbiota whose metabolic activities affect nutrient and trace gas cycling within the global ocean. Here, we report metagenomic analyses of a ubiquitous and abundant but uncultivated oxygen minimum zone microbe (SUP05) related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur oxidation, and nitrate respiration responsive to a wide range of water-column redox states. Our analysis provides a genomic foundation for understanding the ecological and biogeochemical role of pelagic SUP05 in oxygen-deficient oceanic waters and its potential sensitivity to environmental changes.

  18. Towards Versatile Robots Through Open Heterogeneous Modular Robots

    DEFF Research Database (Denmark)

    Lyder, Andreas

    Robots are important tools in our everyday life. Both in industry and at the consumer level they serve the purpose of increasing our scope and extending our capabilities. Modular robots take the next step, allowing us to easily create and build various robots from a set of modules. If a problem...... arises, a new robot can be assembled rapidly from the existing modules, in contrast to conventional robots, which require a time consuming and expensive development process. In this thesis we define a modular robot to be a robot consisting of dynamically reconfigurable modules. The goal of this thesis...... is to increase the versatility and practical usability of modular robots by introducing new conceptual designs. Until now modular robots have been based on a pre-specified set of modules, and thus, their functionality is limited. We propose an open heterogeneous design concept, which allows a modular robot...

  19. Grinder: a versatile amplicon and shotgun sequence simulator.

    Science.gov (United States)

    Angly, Florent E; Willner, Dana; Rohwer, Forest; Hugenholtz, Philip; Tyson, Gene W

    2012-07-01

    We introduce Grinder (http://sourceforge.net/projects/biogrinder/), an open-source bioinformatic tool to simulate amplicon and shotgun (genomic, metagenomic, transcriptomic and metatranscriptomic) datasets from reference sequences. This is the first tool to simulate amplicon datasets (e.g. 16S rRNA) widely used by microbial ecologists. Grinder can create sequence libraries with a specific community structure, α and β diversities and experimental biases (e.g. chimeras, gene copy number variation) for commonly used sequencing platforms. This versatility allows the creation of simple to complex read datasets necessary for hypothesis testing when developing bioinformatic software, benchmarking existing tools or designing sequence-based experiments. Grinder is particularly useful for simulating clinical or environmental microbial communities and complements the use of in vitro mock communities.

  20. The versatile subepithelial connective tissue graft: a literature update.

    Science.gov (United States)

    Karthikeyan, B V; Khanna, Divya; Chowdhary, Kamedh Yashawant; Prabhuji, M Lv

    2016-01-01

    Harmony between hard and soft tissue morphologies is essential for form, function, and a good esthetic outlook. Replacement grafts for correction of soft tissue defects around the teeth have become important to periodontal plastic and implant surgical procedures. Among a multitude of surgical techniques and graft materials reported in literature, the subepithelial connective tissue graft (SCTG) has gained wide popularity and acceptance. The purpose of this article is to acquaint clinicians with the current understanding of the versatile SCTG. Key factors associated with graft harvesting as well as applications, limitations, and complications of SCTGs are discussed. This connective tissue has shown excellent short- and long-term stability, is easily available, and is economical to use. The SCTG should be considered as an alternative in all periodontal reconstruction surgeries.

  1. Versatile and nondestructive photochemical process for biomolecule immobilization.

    Science.gov (United States)

    Viel, Pascal; Walter, Justine; Bellon, Sophie; Berthelot, Thomas

    2013-02-12

    Covalent immobilization of unmodified biological materials as proteins has been performed through a one-step and soft method. This process is based on a polyazidophenylene layer derived from the electroreduction of the parent salt 4-azidobenzenediazonium tetrafluoborate on gold substrates. The wavelength used (365 nm) for the photochemical grafting of a large variety of molecules as biomolecules is a key point to this nondestructive immobilization method. This simple process is also versatile and could be used for covalently binding a wide range of molecules such as polyethylene glycol moieties, for example. To validate this approach for biochip or microarray fabrication, a surface plasmon resonance imaging (SPRi) platform for immobilization of various antibody families was created by grafting G-protein through this process. This SPRi antibodies platform was tested with several consecutive cycles of antigen injections/regeneration steps without loss of activity.

  2. Versatility of PEEK as a fixed partial denture framework

    Directory of Open Access Journals (Sweden)

    Nikita Sinha

    2017-01-01

    Full Text Available Materials used for fixed partial denture (FPD frameworks have had properties of excellent strength, durability, and biocompatibility. Some of the materials which have been used till date include alloys, ceramics, and high-performance polymers such as zirconia, Ni–Cr, lithium disilicate, and so on. All these, though excellent, have their advantages and disadvantages. Hence, the search has always been on for a better material. One such material, which has made its foray into dentistry in the recent times, is polyetheretherketone (PEEK. It is a semicrystalline thermoplastic material. PEEK has an excellent chemical resistance and mechanical properties that are retained at high temperatures. The versatility of PEEK as a dental material for FPD framework was evaluated in this case report.

  3. The Versatile Extended Thoracodorsal Artery Perforator Flap for Breast Reconstruction

    DEFF Research Database (Denmark)

    Jacobs, Jordan; Børsen-Koch, Mikkel; Gunnarsson, Gudjon Leifur

    2015-01-01

    BACKGROUND: The thoracodorsal artery perforator (TAP) flap is a versatile tool that can be used to reconstruct the breast. The authors use preoperative perforator mapping using color Doppler ultrasonography and present a safe, efficient harvesting technique to demonstrate reliable use of the TAP...... flap in reconstructive surgery. METHODS: A multicenter, retrospective review was performed on all patients undergoing TAP flap reconstruction from August 2011 to November 2014. Data were collected from patient records as well as outpatient interviews. RESULTS: A total of 106 TAP flaps were performed...... complications occurred in 10 of 106 (10%) cases and included hematoma (1/108), venous congestion (2/108), and partial flap necrosis (7/108). The reconstructive goal was achieved in 103 of 106 (97%) flaps. CONCLUSIONS: The TAP flap is a pedicled, fasciocutaneous flap that can be used for total breast...

  4. Metagenome of a Versatile Chemolithoautotroph from Expanding Oceanic Dead Zones

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, David A.; Zaikova, Elena; Howes, Charles L.; Song, Young; Wright, Jody; Tringe, Susannah G.; Tortell, Philippe D.; Hallam, Steven J.

    2009-07-15

    Oxygen minimum zones (OMZs), also known as oceanic"dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving but cryptic microbiota whose combined metabolic activity is intimately connected to nutrient and trace gas cycling within the global ocean. Here we report time-resolved metagenomic analyses of a ubiquitous and abundant but uncultivated OMZ microbe (SUP05) closely related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur-oxidation and nitrate respiration responsive to a wide range of water column redox states. Thus, SUP05 plays integral roles in shaping nutrient and energy flow within oxygen-deficient oceanic waters via carbon sequestration, sulfide detoxification and biological nitrogen loss with important implications for marine productivity and atmospheric greenhouse control.

  5. A Versatile Active Block: DXCCCII and Tunable Applications

    Directory of Open Access Journals (Sweden)

    S. A. Tekin

    2014-12-01

    Full Text Available The study describes dual-X controlled current conveyor (DXCCCII as a versatile active block and its application to inductance simulators for testing. Moreover, the high pass filter application using with DXCCCII based inductance simulator and oscillator with flexible tunable oscillation frequency have been presented and simulated to confirm the theoretical validity. The proposed circuit which has a simple circuit design requires the low-voltage and the DXCCCII can also be tuned in the wide range by the biasing current. The proposed DXCCCII provides a good linearity, high output impedance at Z terminals, and a reasonable current and voltage transfer gain accuracy. The proposed DXCCCII and its applications have been simulated using the CMOS 0.18 µm technology.

  6. The human PDI family: Versatility packed into a single fold

    DEFF Research Database (Denmark)

    Appenzeller-Herzog, Christian; Ellgaard, Lars

    2007-01-01

    in promoting oxidative protein folding in the ER has been extended in recent years to include roles in other processes such as ER-associated degradation (ERAD), trafficking, calcium homeostasis, antigen presentation and virus entry. Some of these functions are performed by non-catalytic members of the family...... that lack the active-site cysteines. Regardless of their function, all human PDIs contain at least one domain of approximately 100 amino acid residues with structural homology to thioredoxin. As we learn more about the individual proteins of the family, a complex picture is emerging that emphasizes as much...... their differences as their similarities, and underlines the versatility of the thioredoxin fold. Here, we primarily explore the diversity of cellular functions described for the human PDIs. Udgivelsesdato: 2007-Dec-3...

  7. Submicron Lipid Emulsions: A Versatile Platform for Drug Delivery.

    Science.gov (United States)

    Zhang, Xingwang; Wu, Baojian

    2015-01-01

    Lipid emulsions have turned out to be a versatile tool for systemic delivery of poorly soluble drugs and cytotoxic drugs. Currently, the majority of marketed or developing drugs are recognized as BCS II and IV ones. How to solve the solubility and systemic administration that enables them access to clinical application is arising a great challenge in drug delivery systems. The key considerations for lipid emulsions are how to enhance the drug load, stability and reproducibility. Formulation and manufacture technique play the leading role in development of lipid emulsions. Understanding the biofate and characterization in vitro/vivo is suggestive to exploit the potential of lipid emulsions. This review discussed the manufacture techniques and in vivo behavior of lipid emulsions. Momentous interests were focused on their applications in drug delivery as well as the future evolution. Finally, we appreciated the methodologies of quality control and systemic risks associated with lipid emulsions.

  8. FLUTE: A versatile linac-based THz source

    Energy Technology Data Exchange (ETDEWEB)

    Nasse, M. J.; Schuh, M.; Schwarz, M. [Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Naknaimueang, S.; Mathis, Y.-L.; Rossmanith, R.; Wesolowski, P.; Huttel, E. [ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Plech, A. [Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Schmelling, M. [Max Planck Institute for Nuclear Physics (MPIK), 69117 Heidelberg (Germany); Mueller, A.-S. [Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany)

    2013-02-15

    A new compact versatile linear accelerator named FLUTE is currently being designed at the Karlsruhe Institute of Technology. This paper presents the status of this 42 MeV machine. It will be used to generate strong (several 100 MV/m) ultra-short ({approx}1 ps) THz pulses (up to {approx}4-25 THz) for photon science experiments, as well as to conduct a variety of accelerator studies. The latter range from comparing different coherent THz radiation generation schemes to compressing electron bunches and studying the electron beam stability. The bunch charge will cover a wide range ({approx}100 pC-3 nC). Later we plan to also produce ultra-short x-ray pulses from the electron bunches, which, for example, could then be combined for THz pump-x-ray probe experiments.

  9. FLUTE: a versatile linac-based THz source.

    Science.gov (United States)

    Nasse, M J; Schuh, M; Naknaimueang, S; Schwarz, M; Plech, A; Mathis, Y-L; Rossmanith, R; Wesolowski, P; Huttel, E; Schmelling, M; Müller, A-S

    2013-02-01

    A new compact versatile linear accelerator named FLUTE is currently being designed at the Karlsruhe Institute of Technology. This paper presents the status of this 42 MeV machine. It will be used to generate strong (several 100 MV/m) ultra-short (~1 ps) THz pulses (up to ~4-25 THz) for photon science experiments, as well as to conduct a variety of accelerator studies. The latter range from comparing different coherent THz radiation generation schemes to compressing electron bunches and studying the electron beam stability. The bunch charge will cover a wide range (~100 pC-3 nC). Later we plan to also produce ultra-short x-ray pulses from the electron bunches, which, for example, could then be combined for THz pump-x-ray probe experiments.

  10. Versatile RNA interference nanoplatform for systemic delivery of RNAs.

    Science.gov (United States)

    Choi, Ki Young; Silvestre, Oscar F; Huang, Xinglu; Min, Kyung Hyun; Howard, Gregory P; Hida, Naoki; Jin, Albert J; Carvajal, Nicole; Lee, Sang Wook; Hong, Jong-In; Chen, Xiaoyuan

    2014-05-27

    Development of nontoxic, tumor-targetable, and potent in vivo RNA delivery systems remains an arduous challenge for clinical application of RNAi therapeutics. Herein, we report a versatile RNAi nanoplatform based on tumor-targeted and pH-responsive nanoformulas (NFs). The NF was engineered by combination of an artificial RNA receptor, Zn(II)-DPA, with a tumor-targetable and drug-loadable hyaluronic acid nanoparticle, which was further modified with a calcium phosphate (CaP) coating by in situ mineralization. The NF can encapsulate small-molecule drugs within its hydrophobic inner core and strongly secure various RNA molecules (siRNAs, miRNAs, and oligonucleotides) by utilizing Zn(II)-DPA and a robust CaP coating. We substantiated the versatility of the RNAi nanoplatform by demonstrating effective delivery of siRNA and miRNA for gene silencing or miRNA replacement into different human types of cancer cells in vitro and into tumor-bearing mice in vivo by intravenous administration. The therapeutic potential of NFs coloaded with an anticancer drug doxorubicin (Dox) and multidrug resistance 1 gene target siRNA (siMDR) was also demonstrated in this study. NFs loaded with Dox and siMDR could successfully sensitize drug-resistant OVCAR8/ADR cells to Dox and suppress OVCAR8/ADR tumor cell proliferation in vitro and tumor growth in vivo. This gene/drug delivery system appears to be a highly effective nonviral method to deliver chemo- and RNAi therapeutics into host cells.

  11. Bacterie remt phytophthora

    NARCIS (Netherlands)

    Knuivers, M.; Overbeek, van L.S.

    2009-01-01

    Bacteriën kunnen aardappelplanten weerbaarder maken tegen phytophthora. Uit kas-experimenten van Plant Research International (PRI) blijkt dat de aanwezigheid van de bacteriePseudomonas putida(isolaat P9) in twee late aardappelrassen leidt tot een vertraging met 45 procent van het ziekteverloop na

  12. common bacterial pathogens seen.

    African Journals Online (AJOL)

    Background: Bacterial infections are important causes of morbidity in the neonatal period. Therefore identification of infecting organisms and the risk factors for possible bacterial infection in the newborn is of great importance. Institution early appropriate therapy is an important step in combating morbidity and mortality in this ...

  13. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...... about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria...

  14. Pyrroloquinoline-quinone and its versatile roles in biological ...

    Indian Academy of Sciences (India)

    2012-04-05

    Apr 5, 2012 ... Pyrroloquinoline-quinine (PQQ) was initially characterized as a redox cofactor for membrane-bound dehydrogenases in the bacterial system. Subsequently, PQQ was shown to be an antioxidant protecting the living cells from oxidative damage in vivo and the biomolecules from artificially produced reaction ...

  15. Pyrroloquinoline-quinone and its versatile roles in biological ...

    Indian Academy of Sciences (India)

    Keywords. Antioxidant; biofertilizer and biocontrol agent; biosensor; pharmacological agent; protein kinase inducer; pyrroloquinoline-quinone. Abstract. Pyrroloquinoline-quinine (PQQ) was initially characterized as a redox cofactor for membrane-bound dehydrogenases in the bacterial system. Subsequently, PQQ was ...

  16. A versatile class of cell surface directional motors gives rise to gliding motility and sporulation in Myxococcus xanthus.

    Science.gov (United States)

    Wartel, Morgane; Ducret, Adrien; Thutupalli, Shashi; Czerwinski, Fabian; Le Gall, Anne-Valérie; Mauriello, Emilia M F; Bergam, Ptissam; Brun, Yves V; Shaevitz, Joshua; Mignot, Tâm

    2013-12-01

    Eukaryotic cells utilize an arsenal of processive transport systems to deliver macromolecules to specific subcellular sites. In prokaryotes, such transport mechanisms have only been shown to mediate gliding motility, a form of microbial surface translocation. Here, we show that the motility function of the Myxococcus xanthus Agl-Glt machinery results from the recent specialization of a versatile class of bacterial transporters. Specifically, we demonstrate that the Agl motility motor is modular and dissociates from the rest of the gliding machinery (the Glt complex) to bind the newly expressed Nfs complex, a close Glt paralogue, during sporulation. Following this association, the Agl system transports Nfs proteins directionally around the spore surface. Since the main spore coat polymer is secreted at discrete sites around the spore surface, its transport by Agl-Nfs ensures its distribution around the spore. Thus, the Agl-Glt/Nfs machineries may constitute a novel class of directional bacterial surface transporters that can be diversified to specific tasks depending on the cognate cargo and machinery-specific accessories.

  17. A versatile class of cell surface directional motors gives rise to gliding motility and sporulation in Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Morgane Wartel

    2013-12-01

    Full Text Available Eukaryotic cells utilize an arsenal of processive transport systems to deliver macromolecules to specific subcellular sites. In prokaryotes, such transport mechanisms have only been shown to mediate gliding motility, a form of microbial surface translocation. Here, we show that the motility function of the Myxococcus xanthus Agl-Glt machinery results from the recent specialization of a versatile class of bacterial transporters. Specifically, we demonstrate that the Agl motility motor is modular and dissociates from the rest of the gliding machinery (the Glt complex to bind the newly expressed Nfs complex, a close Glt paralogue, during sporulation. Following this association, the Agl system transports Nfs proteins directionally around the spore surface. Since the main spore coat polymer is secreted at discrete sites around the spore surface, its transport by Agl-Nfs ensures its distribution around the spore. Thus, the Agl-Glt/Nfs machineries may constitute a novel class of directional bacterial surface transporters that can be diversified to specific tasks depending on the cognate cargo and machinery-specific accessories.

  18. A novel and versatile flash-freezing approach for evaluating the health of Delta Smelt.

    Science.gov (United States)

    Teh, Swee J; Baxa, Dolores V; Hammock, Bruce G; Gandhi, Saikrithika A; Kurobe, Tomofumi

    2016-01-01

    A common approach used to assess environmental impacts in aquatic environments is to measure indicators of stress (biomarkers) and condition of fish within ecosystems. Particularly in estuarine ecosystems with multiple stressors, it is often desirable to quantify a suite of biological endpoints that (1) reflect fish condition at several levels of biological organization and time scales and (2) are sensitive to a range of environmental stressors. However, established methods of preservation and processing of fish for specific endpoints are often incompatible. Here, we developed a novel flash-freezing approach for assessing the health of a small, sensitive fish, the endangered Delta Smelt (Hypomesus transpacificus) after collections from the San Francisco Estuary (SFE). We assess whether flash-freezing the entire fish ensures effective preservation of multiple tissues for subsequent biomarker analyses by comparing measurements of fresh to frozen tissue. Tissues included brain, gill, and liver for enzyme activity, kidney and spleen for pathogens, and gills, liver, and gonads for histopathology and reproduction. Although flash-freezing in liquid nitrogen altered the length, weight, and condition factor of Delta Smelt, the percent changes were small (Freezing artefacts were observed in ovaries, but did not hinder the identification and interpretation of cell types and oocyte stages. Freezing did not alter bacterial isolation or the activities of ethoxyresorufin-0-deethylase (EROD) or acetylcholinesterase (AChE), but had a small, negative influence on sodium potassium adenosine triphosphatase (ATPase) activity. Thus, flash-freezing in the field is a versatile preservation method for Delta Smelt, allowing for multiple tissue collections and bioassays from an individual tiny fish exposed to a wide range of natural and anthropogenic stressors. Similar methodology may be applicable to other species for which a range of biological endpoints and histopathology data are needed

  19. Bacterial hemorrhagic enterocolitis.

    Science.gov (United States)

    Ina, Kenji; Kusugami, Kazuo; Ohta, Michio

    2003-01-01

    Bacterial diarrhea can be classified into two clinical entities, noninflammatory diarrhea and inflammatory diarrhea syndromes. The latter type of diarrhea is characterized by bloody and puruloid mucus stool, and is often accompanied by fever, tenesmus, and severe abdominal pain. Pathogenic bacteria causing the inflammatory diarrhea syndrome include Salmonella, Vibrio, Shigella, enteroinvasive and enterohemorrhagic Escherichia coli, Campylobacter, Yersinia, Chlamydia, and Clostridium difficile. The pathologic changes in the inflammatory diarrhea syndrome range from a superficial exudative enterocolitis to a transmural enterocolitis with overt ulceration. This syndrome is also designated as bacterial hemorrhagic enterocolitis because of its usual manifestation by bloody diarrhea. The diagnostic approach needs information on the patient's age, travel history, epidemiological associations, sexual practice, and medical history, including usage of antibiotics. Bacterial information can be obtained by microscopic study, culture, and the identification of specific bacterial toxins. Flexible colonoscopy with biopsy is useful for the differentiation of bacterial hemorrhagic enterocolitis from idiopathic ulcerative colitis and ischemic colitis. Physicians should be familiar with the diagnostic modalities used to detect the specific pathogens causing hemorrhagic bacterial enterocolitis; namely, bacterial culture, serology, histology, and nucleic acid technologies.

  20. An analysis of the self-control and criminal versatility of gang and dating violence offenders.

    Science.gov (United States)

    Chapple, Constance L; Hope, Trina L

    2003-12-01

    How versatile are gang and dating violence offenders? Current gang research highlights the versatility of gang members, yet the versatility of intimate violence offenders is often unexamined. Gottfredson and Hirschi, A General Theory of Crime (1990), support the idea of versatile rather than specialized offenders and suggests that low self-control is associated with a host of criminal and noncriminal risk-taking activities. Using data from a self-report sample of 1139 youths in grades 9 through 11, we investigated both the versatility of gang and dating violence offenders and theoretical variables associated with each. We find disproportionate offending by dating and gang violence offenders in a variety of crimes, as well as considerable overlap in the independent variables associated with both types of violence. Low levels of self-control and exposure to general and crime-specific criminal opportunities are significantly associated with engaging in dating and gang violence.

  1. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  2. Aortic bacterial endarteritis.

    Science.gov (United States)

    Ma Maroto, M J; Gorodezky, M; Contreras, R; C'ardenas, M

    1975-01-01

    Micotic aneurisms are very rare. They are produced as a consequence of a bacterial infection of the endartery. They are divided into "primary", or those of an unknown septic focus, and "secondary" to bacterial endocarditis, to intravascular in infection or to infection located in a neighboring region. Two cases of the National Institute of Cardiology of Mexico are presented, with "primary" micotic aneurysm, which is the least frequent. One of them was because of bacterial endarteritis located in the thoracic aorta, an extremely rate entity. Due to the frequent rupture of these aneurysm with a very high mortality, emphasis is placed on the convenience of rapid surgical treatment of patients diagnosed.

  3. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  4. Bacterial Skin Infections

    Science.gov (United States)

    ... Summer Camp Tips for Kids With Asthma, Allergies Antioxidants: The Good Health Helpers As Stroke 'Liquefies' Brain ... Cancer Additional Content Medical News Overview of Bacterial Skin Infections By A. Damian Dhar, MD, JD, Private ...

  5. When bacterial tracheitis complicates

    Directory of Open Access Journals (Sweden)

    Joana Teixeira

    2015-12-01

    Full Text Available Introduction: Viral croup is the most common cause of stridor in children seen at emergency room. In the absence of response to treatment with corticosteroids and nebulized adrenaline, bacterial tracheitis should be considered. Case Report: A six year-old child, was admitted in emergency room with stridor, respiratory distress and fever, with partial response to therapy with nebulized epinephrine. Ceftriaxone was prescribed for suspected bacterial laryngotracheobronchitis. Despite therapy, developed cervical cellulitis with progression to retropharyngeal abscess and mediastinitis. Good outcome after therapy with ceftriaxone, clindamycin and vancomycin. Discussion/Conclusion: The authors describe an original case of a bacterial tracheitis complicated with retropharyngeal abcess and mediastinitis, emphasizing that bacterial tracheitis is potentially life threatening, requiring a high index of suspicion for early diagnosis.

  6. Bacterial Wound Culture

    Science.gov (United States)

    ... and services. Advertising & Sponsorship: Policy | Opportunities Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  7. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  8. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  9. miR-9: a versatile regulator of neurogenesis

    Directory of Open Access Journals (Sweden)

    Marion Coolen

    2013-11-01

    Full Text Available Soon after its discovery, microRNA-9 (miR-9 attracted the attention of neurobiologists, since it is one of the most highly expressed microRNAs in the developing and adult vertebrate brain. Functional analyses in different vertebrate species have revealed a prominent role of this microRNA in balancing proliferation in embryonic neural progenitor populations. Key transcriptional regulators such as FoxG1, Hes1 or Tlx, were identified as direct targets of miR-9, placing it at the core of the gene network controlling the progenitor state. Recent data also suggest that this function could extend to adult neural stem cells. Other studies point to a role of miR-9 in differentiated neurons. Moreover miR-9 has been implicated in human brain pathologies, either displaying a protective role, such as in Progeria, or participating in disease progression in brain cancers. Altogether functional studies highlight a prominent feature of this highly conserved microRNA, its functional versatility, both along its evolutionary history and across cellular contexts.

  10. Scalable and versatile graphene functionalized with the Mannich condensate.

    Science.gov (United States)

    Liao, Ruijuan; Tang, Zhenghai; Lin, Tengfei; Guo, Baochun

    2013-03-01

    The functionalized graphene (JTPG) is fabricated by chemical conversion of graphene oxide (GO), using tea polyphenols (TP) as the reducer and stabilizer, followed by further derivatization through the Mannich reaction between the pyrogallol groups on TP and Jeffamine M-2070. JTPG exhibits solubility in a broad spectrum of solvents, long-term stability and single-layered dispersion in water and organic solvents, which are substantiated by AFM, TEM, and XRD. The paper-like JTPG hybrids prepared by vacuum-assisted filtration exhibits an unusual combination of high toughness (tensile strength of ~275 MPa and break strain of ~8%) and high electrical conductivity (~700 S/m). Still, JTPG is revealed to be very promising in the fabrication of polymer/graphene composites due to the excellent solubility in the solvent with low boiling point and low toxicity. Accordingly, as an example, nitrile rubber/JTPG composites are fabricated by the solution compounding in acetone. The resulted composite shows low threshold percolation at 0.23 vol.% of graphene. The versatilities both in dispersibility and performance, together with the scalable process of JTPG, enable a new way to scale up the fabrication of the graphene-based polymer composites or hybrids with high performance.

  11. Soluble Lead and Bismuth Chalcogenidometallates: Versatile Solders for Thermoelectric Materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [Department; Son, Jae Sung [Department; School; Dolzhnikov, Dmitriy S. [Department; Filatov, Alexander S. [Department; Hazarika, Abhijit [Department; Wang, Yuanyuan [Department; Hudson, Margaret H. [Department; Sun, Cheng-Jun [Advanced; Chattopadhyay, Soma [Physical; Talapin, Dmitri V. [Department; Center

    2017-07-27

    Here we report the syntheses of largely unexplored lead and bismuth chalcogenidometallates in the solution phase. Using N2H4 as the solvent, new compounds such as K6Pb3Te6·7N2H4 were obtained. These soluble molecular compounds underwent cation exchange processes using resin chemistry, replacing Na+ or K+ by decomposable N2H5+ or tetraethylammonium cations. They also transformed into stoichiometric lead and bismuth chalcogenide nanomaterials with the addition of metal salts. Such a versatile chemistry led to a variety of composition-matched solders to join lead and bismuth chalcogenides and tune their charge transport properties at the grain boundaries. Solution-processed thin films composed of Bi0.5Sb1.5Te3 microparticles soldered by (N2H5)6Bi0.5Sb1.5Te6 exhibited thermoelectric power factors (~28 μW/cm K2) comparable to those in vacuum-deposited Bi0.5Sb1.5Te3 films. The soldering effect can also be integrated with attractive fabrication techniques for thermoelectric modules, such as screen printing, suggesting the potential of these solders in the rational design of printable and moldable thermoelectrics.

  12. A Versatile Software Program for Sampling Sferics and More

    Science.gov (United States)

    Stanley, M. A.; Lyons, W. A.; Cummer, S. A.; Jaugey, N.

    2008-12-01

    In 2004, a data acquisition program was written to sample and store sferic waveforms for the upgraded Los Alamos Sferic Array (LASA). The program acquired data using the 20MHz PCI-DAS4020/12 Measurement Computing (MC) board on the stable Linux operating system. The capabilities of this original program have been described elsewhere [Stanley et al., 2004; Shao et al., 2006]. Starting in 2006, this program was modified and enhanced to support data acquisition for a new Charge Moment Change Network (CMCN) which detects and quantifies impulsive charge moment changes of potential sprite-producing lightning discharges in near real-time. Some of the more notable modifications included the addition of low-pass filtered continuous data output capabilities as well as support for National Instruments (NI) boards. The continuous data output was particularly well suited for the unambiguous detection of sferics with slow tails which are often found around the time of sprites and especially sprite halos. The program also utilizes a shared memory architecture which gives it even more versatility in real-time processing as well as enables other modes of data acquisition. In 2008, the program was updated to utilize the Linux Comedi drivers in place of the previous MC and NI drivers. With this modification, the program now supports an even wider variety of data acquisition boards and also runs on the latest Linux distributions.

  13. Sapporo2: a versatile direct N-body library

    Science.gov (United States)

    Bédorf, Jeroen; Gaburov, Evghenii; Portegies Zwart, Simon

    2015-10-01

    Astrophysical direct N-body methods have been one of the first production algorithms to be implemented using NVIDIA's CUDA architecture. Now, almost seven years later, the GPU is the most used accelerator device in astronomy for simulating stellar systems. In this paper we present the implementation of the Sapporo2 N-body library, which allows researchers to use the GPU for N-body simulations with little to no effort. The first version, released five years ago, is actively used, but lacks advanced features and versatility in numerical precision and support for higher order integrators. In this updated version we have rebuilt the code from scratch and added support for OpenCL, multi-precision and higher order integrators. We show how to tune these codes for different GPU architectures and present how to continue utilizing the GPU optimal even when only a small number of particles (N < 100) is integrated. This careful tuning allows Sapporo2 to be faster than Sapporo1 even with the added options and double precision data loads. The code runs on a range of NVIDIA and AMD GPUs in single and double precision accuracy. With the addition of OpenCL support the library is also able to run on CPUs and other accelerators that support OpenCL.

  14. TriPleX: a versatile dielectric photonic platform

    Science.gov (United States)

    Wörhoff, Kerstin; Heideman, René G.; Leinse, Arne; Hoekman, Marcel

    2015-04-01

    Photonic applications based on planar waveguide technology impose stringent requirements on properties such as optical propagation losses, light coupling to optical fibers, integration density, as well as on reliability and reproducibility. The latter is correlated to a high level of control of the refractive index and waveguide geometry. In this paper, we review a versatile dielectric waveguide platform, called TriPleX, which is based on alternating silicon nitride and silicon dioxide films. Fabrication with CMOS-compatible equipment based on low-pressure chemical vapor deposition enables the realization of stable material compositions being a prerequisite to the control of waveguide properties and modal shape. The transparency window of both materials allows for the realization of low-loss waveguides over a wide wavelength range (400 nm-2.35 μm). Propagation losses as low as 5×10-4 dB/cm are reported. Three basic geometries (box shell, double stripe, and filled box) can be distinguished. A specific tapering technology is developed for on-chip, low-loss (functional complexity as well as for hybrid integration with other photonic platforms such as InP and SOI. The functionality of the TriPleX platform is captured by verified basic building blocks. The corresponding library and associated design kit is available for multi-project wafer (MPW) runs. Several applications of this platform technology in communications, biomedicine, sensing, as well as a few special fields of photonics are treated in more detail.

  15. Bits and q-bits as versatility measures

    Directory of Open Access Journals (Sweden)

    José R.C. Piqueira

    2004-06-01

    Full Text Available Using Shannon information theory is a common strategy to measure any kind of variability in a signal or phenomenon. Some methods were developed to adapt information entropy measures to bird song data trying to emphasize its versatility aspect. This classical approach, using the concept of bit, produces interesting results. Now, the original idea developed in this paper is to use the quantum information theory and the quantum bit (q-bit concept in order to provide a more complete vision of the experimental results.Usar a teoria da informação de Shannon é uma estratégia comum para medir todo tipo de variabilidade em um sinal ou fenômeno. Alguns métodos foram desenvolvidos para adaptar a medida de entropia informacional a dados de cantos de pássaro, tentando enfatizar seus aspectos de versatilidade. Essa abordagem clássica, usando o conceito de bit, produz resultados interessantes. Agora, a idéia original desenvolvida neste artigo é usar a teoria quântica da informação e o conceito de q-bit, com a finalidade de proporcionar uma visão mais completa dos resultados experimentais.

  16. Exploring the versatility of gingiva-colored composite

    Directory of Open Access Journals (Sweden)

    Paryag AA

    2016-04-01

    Full Text Available Amit A Paryag,1 Reisha N Rafeek,1 Melissa S Mankee,2 Jenai Lowe1 1School of Dentistry, The University of the West Indies, Mount Hope, 2Tooth Haven Dental Studio, D'Abadie, Trinidad and Tobago Abstract: Gingival recession has a diverse etiology. The consequences may include gingivitis, periodontitis, and hypersensitivity. Whereas the management can include surgical treatment options, sometimes a more conservative, yet still esthetic approach may be required. The use of gingiva-colored composites provides one such alternative and can be applied to varying presentations of the problem. While surgical treatment can be successful in re-creating favorable esthetic anatomy as well as achieving accurate tissue contour in cases when minor amounts of tissue are reconstructed, long-term results vary because of the vascularity and complexity of the interdental space. Factors such as cost, healing time, discomfort, and variable long-term results make surgery an unpopular choice. If tooth-colored restorative materials are utilized to restore cervical tooth exposure as a result of severe recession, the disproportionate appearance of the visible crown may give a dissatisfying result. Gingiva-colored composite provides dental practitioners with a versatile material that can be used to directly restore cervical defects caused by gingival recession, thus correcting the appearance of the gingival anatomy. It offers a treatment option that may increase patient satisfaction through the provision of a cost-effective, minimally invasive solution with highly esthetic results. Keywords: gingiva composite, cervical restoration, esthetics

  17. Collinear technology for holographic versatile disc (HVD) system

    Science.gov (United States)

    Tan, Xiaodi; Horimai, Hideyoshi; Shimura, Tsutomu; Ichimura, Shotaro; Fujimura, Ryushi; Kuroda, Kazuo

    2006-09-01

    Holographic Versatile Disc (HVD TM) using Collinear TM Technologies is proposed by OPTWARE Corporation, in which the information and reference beams are displayed co-axially by the same SLM. With this unique configuration the optical pickup can be designed as small as the DVD's, and can be placed on one side of the recording disc. In HVD TM structure, the pre-formatted meta-data reflective layer is used for the focus/tracking servo and reading address information, and the dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increased recording density of HVD TM. Experimental and theoretical studies suggest that the holographic material is very effective to increased recording density of the system. As the servo technology is being introduced to control the objective lens to be maintained precisely to the disc in the recording and the reconstructing process, a vibration isolator is no longer necessary. HVD TM will be compatible with existing disc storage systems, like CD and DVD, and enable us to expand its applications into other optical information storage systems.

  18. Versatile genetic tool box for the crenarchaeote Sulfolobus acidocaldarius

    Directory of Open Access Journals (Sweden)

    Michaela eWagner

    2012-06-01

    Full Text Available For reverse genetic approaches inactivation or selective modification of genes are required to elucidate their putative function. Sulfolobus acidocaldarius is a thermoacidophilic Crenarchaeon which grows optimally at 76 °C and pH 3. As many antibiotics do not withstand these conditions the development of a genetic system in this organism is dependent on auxotrophies. Therefore we constructed a pyrE deletion mutant of S. acidocaldarius wild type strain DSM639 missing 322 bp called MW001. Using this strain as the base, we describe here different methods using single as well as double crossover events to obtain markerless deletion mutants, tag genes genomically and ectopically integrate foreign DNA into MW001. These methods enable us to construct single, double and triple deletions strains that can still be complemented with the pRN1 based expression vector. Taken together we have developed a versatile and robust genetic tool box for the crenarchaeote Sulfolobus acidocaldarius that will promote the study of unknown gene functions in this organism and makes this organism a suitable host for synthetic biology approaches.

  19. Versatile Molecular Silver Ink Platform for Printed Flexible Electronics.

    Science.gov (United States)

    Kell, Arnold J; Paquet, Chantal; Mozenson, Olga; Djavani-Tabrizi, Iden; Deore, Bhavana; Liu, Xiangyang; Lopinski, Gregory P; James, Robert; Hettak, Khelifa; Shaker, Jafar; Momciu, Adrian; Ferrigno, Julie; Ferrand, Olivier; Hu, Jian Xiong; Lafrenière, Sylvie; Malenfant, Patrick R L

    2017-05-24

    A silver molecular ink platform formulated for screen, inkjet, and aerosol jet printing is presented. A simple formulation comprising silver neodecanoate, ethyl cellulose, and solvent provides improved performance versus that of established inks, yet with improved economics. Thin, screen-printed traces with exceptional electrical (inks. Low surface roughness, submicron thicknesses, and line widths as narrow as 41 μm outperform commercial ink benchmarks based on flakes or nanoparticles. These traces are mechanically robust to flexing and creasing (less than 10% change in resistance) and bind strongly to epoxy-based adhesives. Thin traces are remarkably conformal, enabling fully printed metal-insulator-metal band-pass filters. The versatility of the molecular ink platform enables an aerosol jet-compatible ink that yields conductive features on glass with 2× bulk resistivity and strong adhesion to various plastic substrates. An inkjet formulation is also used to print top source/drain contacts and demonstrate printed high-mobility thin film transistors (TFTs) based on semiconducting single-walled carbon nanotubes. TFTs with mobility values of ∼25 cm2 V-1 s-1 and current on/off ratios >104 were obtained, performance similar to that of evaporated metal contacts in analogous devices.

  20. Versatile bioelectronic interfaces on flexible non-conductive substrates.

    Science.gov (United States)

    Hassler, Brian L; Amundsen, Ted J; Zeikus, J Gregory; Lee, Ilsoon; Worden, Robert M

    2008-05-15

    Bioelectronic interfaces that establish electrical communication between redox enzymes and electrodes have potential applications as biosensors, biocatalytic reactors, and biological fuel cells. These interfaces are commonly formed on gold films deposited using physical vapor deposition (PVD) or chemical vapor deposition (CVD). PVD and CVD require deposition of a primer layer, such as titanium or chromium, and require the use of expensive equipment and cannot be used on a wide range of substrates. This paper describes a versatile new bench-top method to form bioelectronic interfaces containing a gold film, electron mediator, cofactor, and dehydrogenase enzyme (secondary alcohol dehydrogenase, and sorbitol dehydrogenase) on nonconductive substrates such as polystyrene and glass. The method combines layer-by-layer deposition of polyelectrolytes, electroless metal deposition, and directed molecular self-assembly. Cyclic voltammetry, chronoamperometry, field emission X-ray dispersive spectroscopy, scanning electron microscopy, and atomic force microscopy were used to characterize the bioelectronic interfaces. Interfaces formed on flexible polystyrene slides were shown to retain their activity after bending to a radius of curvature of 18mm, confirming that the approach can be applied on cheap and flexible substrates for applications where traditional wafer-scale electronics is not suitable, such as personal or structural health monitors and rolled microtube biosensors.

  1. 3D printing of versatile reactionware for chemical synthesis.

    Science.gov (United States)

    Kitson, Philip J; Glatzel, Stefan; Chen, Wei; Lin, Chang-Gen; Song, Yu-Fei; Cronin, Leroy

    2016-05-01

    In recent decades, 3D printing (also known as additive manufacturing) techniques have moved beyond their traditional applications in the fields of industrial manufacturing and prototyping to increasingly find roles in scientific research contexts, such as synthetic chemistry. We present a general approach for the production of bespoke chemical reactors, termed reactionware, using two different approaches to extrusion-based 3D printing. This protocol describes the printing of an inert polypropylene (PP) architecture with the concurrent printing of soft material catalyst composites, using two different 3D printer setups. The steps of the PROCEDURE describe the design and preparation of a 3D digital model of the desired reactionware device and the preparation of this model for use with fused deposition modeling (FDM) type 3D printers. The protocol then further describes the preparation of composite catalyst-silicone materials for incorporation into the 3D-printed device and the steps required to fabricate a reactionware device. This combined approach allows versatility in the design and use of reactionware based on the specific needs of the experimental user. To illustrate this, we present a detailed procedure for the production of one such reactionware device that will result in the production of a sealed reactor capable of effecting a multistep organic synthesis. Depending on the design time of the 3D model, and including time for curing and drying of materials, this procedure can be completed in ∼3 d.

  2. Versatility of cyclodextrins in self-assembly systems of amphiphiles.

    Science.gov (United States)

    Jiang, Lingxiang; Yan, Yun; Huang, Jianbin

    2011-11-14

    Recently, cyclodextrins (CDs) were found to play important yet complicated (or even apparently opposite sometimes) roles in self-assembly systems of amphiphiles or surfactants. Herein, we try to review and clarify the versatility of CDs in surfactant assembly systems by 1) classifying the roles played by CDs into two groups (modulator and building unit) and four subgroups (destructive and constructive modulators, amphiphilic and unamphiphilic building units), 2) comparing these subgroups, and 3) analyzing mechanisms. As a modulator, although CDs by themselves do not participate into the final surfactant aggregates, they can greatly affect the aggregates in two ways. In most cases CDs will destroy the aggregates by depleting surfactant molecules from the aggregates (destructive), or in certain cases CDs can promote the aggregates to grow by selectively removing the less-aggregatable surfactant molecules from the aggregates (constructive). As an amphiphilic building unit, CDs can be chemically (by chemical bonds) or physically (by host-guest interaction) attached to a hydrophobic moiety, and the resultant compounds act as classic amphiphiles. As an unamphiphilic building unit, CD/surfactant complexes or even CDs on their own can assemble into aggregates in an unconventional, unamphiphilic manner driven by CD-CD H-bonds. Moreover, special emphasis is put on two recently appeared aspects: the constructive modulator and unamphiphilic building unit. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Zebrafish: A Versatile Animal Model for Fertility Research

    Directory of Open Access Journals (Sweden)

    Jing Ying Hoo

    2016-01-01

    Full Text Available The utilization of zebrafish in biomedical research is very common in the research world nowadays. Today, it has emerged as a favored vertebrate organism for the research in science of reproduction. There is a significant growth in amount numbers of scientific literature pertaining to research discoveries in reproductive sciences in zebrafish. It has implied the importance of zebrafish in this particular field of research. In essence, the current available literature has covered from the very specific brain region or neurons of zebrafish, which are responsible for reproductive regulation, until the gonadal level of the animal. The discoveries and findings have proven that this small animal is sharing a very close/similar reproductive system with mammals. More interestingly, the behavioral characteristics and along with the establishment of animal courtship behavior categorization in zebrafish have laid an even stronger foundation and firmer reason on the suitability of zebrafish utilization in research of reproductive sciences. In view of the immense importance of this small animal for the development of reproductive sciences, this review aimed at compiling and describing the proximate close similarity of reproductive regulation on zebrafish and human along with factors contributing to the infertility, showing its versatility and its potential usage for fertility research.

  4. Versatile protein tagging in cells with split fluorescent protein.

    Science.gov (United States)

    Kamiyama, Daichi; Sekine, Sayaka; Barsi-Rhyne, Benjamin; Hu, Jeffrey; Chen, Baohui; Gilbert, Luke A; Ishikawa, Hiroaki; Leonetti, Manuel D; Marshall, Wallace F; Weissman, Jonathan S; Huang, Bo

    2016-03-18

    In addition to the popular method of fluorescent protein fusion, live cell protein imaging has now seen more and more application of epitope tags. The small size of these tags may reduce functional perturbation and enable signal amplification. To address their background issue, we adapt self-complementing split fluorescent proteins as epitope tags for live cell protein labelling. The two tags, GFP11 and sfCherry11 are derived from the eleventh β-strand of super-folder GFP and sfCherry, respectively. The small size of FP11-tags enables a cost-effective and scalable way to insert them into endogenous genomic loci via CRISPR-mediated homology-directed repair. Tandem arrangement FP11-tags allows proportional enhancement of fluorescence signal in tracking intraflagellar transport particles, or reduction of photobleaching for live microtubule imaging. Finally, we show the utility of tandem GFP11-tag in scaffolding protein oligomerization. These experiments illustrate the versatility of FP11-tag as a labelling tool as well as a multimerization-control tool for both imaging and non-imaging applications.

  5. Surface display of proteins by Gram-negative bacterial autotransporters

    Directory of Open Access Journals (Sweden)

    Mourez Michael

    2006-06-01

    Full Text Available Abstract Expressing proteins of interest as fusions to proteins of the bacterial envelope is a powerful technique with many biotechnological and medical applications. Autotransporters have recently emerged as a good tool for bacterial surface display. These proteins are composed of an N-terminal signal peptide, followed by a passenger domain and a translocator domain that mediates the outer membrane translocation of the passenger. The natural passenger domain of autotransporters can be replaced by heterologous proteins that become displayed at the bacterial surface by the translocator domain. The simplicity and versatility of this system has made it very attractive and it has been used to display functional enzymes, vaccine antigens as well as polypeptides libraries. The recent advances in the study of the translocation mechanism of autotransporters have raised several controversial issues with implications for their use as display systems. These issues include the requirement for the displayed polypeptides to remain in a translocation-competent state in the periplasm, the requirement for specific signal sequences and "autochaperone" domains, and the influence of the genetic background of the expression host strain. It is therefore important to better understand the mechanism of translocation of autotransporters in order to employ them to their full potential. This review will focus on the recent advances in the study of the translocation mechanism of autotransporters and describe practical considerations regarding their use for bacterial surface display.

  6. Versatile selection technology for intracellular protein–protein interactions mediated by a unique bacterial hitchhiker transport mechanism

    Science.gov (United States)

    Waraho, Dujduan; DeLisa, Matthew P.

    2009-01-01

    We have developed a reliable genetic selection strategy for isolating interacting proteins based on the “hitchhiker” mechanism of the Escherichia coli twin-arginine translocation (Tat) pathway. This method, designated FLI-TRAP (functional ligand-binding identification by Tat-based recognition of associating proteins), is based on the unique ability of the Tat system to efficiently cotranslocate noncovalent complexes of 2 folded polypeptides. In the FLI-TRAP assay, the protein to be screened for interactions is engineered with an N-terminal Tat signal peptide, whereas the known or putative partner protein is fused to mature TEM-1 β-lactamase (Bla). Using a series of c-Jun and c-Fos leucine zipper (JunLZ and FosLZ) variants of known affinities, we observed that only those chimeras that expressed well and interacted strongly in the cytoplasm were able to colocalize Bla into the periplasm and confer β-lactam antibiotic resistance to cells. Likewise, the assay was able to efficiently detect interactions between intracellular single-chain Fv (scFv) antibodies and their cognate antigens. The utility of FLI-TRAP was then demonstrated through random library selections of amino acid substitutions that restored (i) heterodimerization to a noninteracting FosLZ variant, and (ii) antigen binding to a low-affinity scFv antibody. Because Tat substrates must be correctly folded before transport, FLI-TRAP favors the identification of soluble, nonaggregating, protease-resistant protein pairs and, thus, provides a powerful tool for routine selection of interacting partners (e.g., antibody-antigen), without the need for purification or immobilization of the binding target. PMID:19234130

  7. Controlled Electrochemical Carboxylation of Graphene To Create a Versatile Chemical Platform for Further Functionalization

    DEFF Research Database (Denmark)

    Bjerglund Pedersen, Emil; Kongsfelt, Mikkel; Shimizu, Kyoko

    2014-01-01

    , this electrochemical method offers a versatile procedure to make all graphene sheets in a multi-layered but expanded structure accessible for functionalization. On a more general level, this approach will provide a versatile way of forming new hybrid materials based on intimate bond coupling to graphene via......An electrochemical approach is introduced for the versatile carboxylation of multi-layered graphene in 0.1 M Bu4NBF4/MeCN. First, the graphene substrate (i.e., graphene chemically vapor-deposited on Ni) is negatively charged at -1.9 V versus Ag/AgI in a degassed solution to allow for intercalation...

  8. Urticaria and bacterial infections.

    Science.gov (United States)

    Minciullo, Paola L; Cascio, Antonio; Barberi, Giuseppina; Gangemi, Sebastiano

    2014-01-01

    The association between urticaria and infectious diseases has been discussed for >100 years. However, a causal relationship with underlying or precipitating infection is difficult to establish. The purpose of this work was to perform a systematic analysis of the published cases of urticaria associated with bacterial infections. We give an umbrella breakdown of up-to-date systematic reviews and other important publications on the complex association of urticaria and bacterial infections. We did a Medline search, for English language articles published until January 2014, using the key words "urticaria" and "bacteria/bacterial disease"; a second analysis was performed in groups of bacteria and using each germ name as a key word. Many bacterial infections have been associated with urticaria manifestation, such as Helicobacter pylori, Streptococcus, Staphylococcus, Mycoplasma pneumonia, Salmonella, Brucella, Mycobacterium leprae, Borrelia, Chlamydia pneumonia, and Yersinia enterocolitica. In some cases the skin manifestations, described as urticaria, could be caused by the presence of the microorganism in the skin, or for the action of their toxins, or to the complement activation mediated by circulating immune complexes. Although only a weak association with urticaria of unclear pathogenesis exists, clinicians should consider these bacterial agents in the workup of the patients with urticaria. The eradication of the infection could, in fact, lead to the resolution of urticaria. Prospective studies and well-structured research are obviously needed to better clarify the real role of bacteria in the pathogenesis of urticaria and their relative prevalence.

  9. Bacterial Cell Mechanics.

    Science.gov (United States)

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  10. Second-Generation Drosophila Chemical Tags: Sensitivity, Versatility, and Speed.

    Science.gov (United States)

    Sutcliffe, Ben; Ng, Julian; Auer, Thomas O; Pasche, Mathias; Benton, Richard; Jefferis, Gregory S X E; Cachero, Sebastian

    2017-04-01

    Labeling and visualizing cells and subcellular structures within thick tissues, whole organs, and even intact animals is key to studying biological processes. This is particularly true for studies of neural circuits where neurons form submicron synapses but have arbors that may span millimeters in length. Traditionally, labeling is achieved by immunofluorescence; however, diffusion of antibody molecules (>100 kDa) is slow and often results in uneven labeling with very poor penetration into the center of thick specimens; these limitations can be partially addressed by extending staining protocols to over a week (Drosophila brain) and months (mice). Recently, we developed an alternative approach using genetically encoded chemical tags CLIP, SNAP, Halo, and TMP for tissue labeling; this resulted in >100-fold increase in labeling speed in both mice and Drosophila, at the expense of a considerable drop in absolute sensitivity when compared to optimized immunofluorescence staining. We now present a second generation of UAS- and LexA-responsive CLIPf, SNAPf, and Halo chemical labeling reagents for flies. These multimerized tags, with translational enhancers, display up to 64-fold increase in sensitivity over first-generation reagents. In addition, we developed a suite of conditional reporters (4xSNAPf tag and CLIPf-SNAPf-Halo2) that are activated by the DNA recombinase Bxb1. Our new reporters can be used with weak and strong GAL4 and LexA drivers and enable stochastic, intersectional, and multicolor Brainbow labeling. These improvements in sensitivity and experimental versatility, while still retaining the substantial speed advantage that is a signature of chemical labeling, should significantly increase the scope of this technology. Copyright © 2017 Sutcliffe et al.

  11. Versatile rogue waves in scalar, vector, and multidimensional nonlinear systems

    Science.gov (United States)

    Chen, Shihua; Baronio, Fabio; Soto-Crespo, Jose M.; Grelu, Philippe; Mihalache, Dumitru

    2017-11-01

    This review is dedicated to recent progress in the active field of rogue waves, with an emphasis on the analytical prediction of versatile rogue wave structures in scalar, vector, and multidimensional integrable nonlinear systems. We first give a brief outline of the historical background of the rogue wave research, including referring to relevant up-to-date experimental results. Then we present an in-depth discussion of the scalar rogue waves within two different integrable frameworks—the infinite nonlinear Schrödinger (NLS) hierarchy and the general cubic-quintic NLS equation, considering both the self-focusing and self-defocusing Kerr nonlinearities. We highlight the concept of chirped Peregrine solitons, the baseband modulation instability as an origin of rogue waves, and the relation between integrable turbulence and rogue waves, each with illuminating examples confirmed by numerical simulations. Later, we recur to the vector rogue waves in diverse coupled multicomponent systems such as the long-wave short-wave equations, the three-wave resonant interaction equations, and the vector NLS equations (alias Manakov system). In addition to their intriguing bright–dark dynamics, a series of other peculiar structures, such as coexisting rogue waves, watch-hand-like rogue waves, complementary rogue waves, and vector dark three sisters, are reviewed. Finally, for practical considerations, we also remark on higher-dimensional rogue waves occurring in three closely-related (2  +  1)D nonlinear systems, namely, the Davey–Stewartson equation, the composite (2  +  1)D NLS equation, and the Kadomtsev–Petviashvili I equation. As an interesting contrast to the peculiar X-shaped light bullets, a concept of rogue wave bullets intended for high-dimensional systems is particularly put forward by combining contexts in nonlinear optics.

  12. Versatility of radial forearm free flap for intraoral reconstruction

    Directory of Open Access Journals (Sweden)

    Jeremić Jelena V.

    2015-01-01

    Full Text Available Introduction. The radial forearm free flap has an important role in reconstruction of the oncologic defects in the region of head and neck. Objective. The aim was to present and evaluate clinical experience and results in the radial forearm free transfer for intraoral reconstructions after resections due to malignancies. Methods. This article illustrates the versatility and reliability of forearm single donor site in 21 patients with a variety of intraoral oncologic defects who underwent immediate (19 patients, 90.5% or delayed (2 patients, 9.5% reconstruction using free flaps from the radial forearm. Fascio-cutaneous flaps were used in patients with floor of the mouth (6 cases, buccal mucosa (5 cases, lip (1 case and a retromolar triangle (2 cases defects, or after hemiglossectomy (7 cases. In addition, the palmaris longus tendon was included with the flap in 2 patients that required oral sphincter reconstruction. Results. An overall success rate was 90.5%. Flap failures were detected in two (9.5% patients, in one patient due to late ischemic necrosis, which appeared one week after the surgery, and in another patient due to venous congestion, which could not be salvaged after immediate re-exploration. Two patients required re-exploration due to vein thrombosis. The donor site healed uneventfully in all patients, except one, who had partial loss of skin graft. Conclusion. The radial forearm free flap is, due to multiple advantages, an acceptable method for reconstructions after resection of intraoral malignancies. [Projekat Ministarstva nauke Republike Srbije, br. 41006

  13. Lithium: a versatile tool for understanding renal physiology

    Science.gov (United States)

    Ecelbarger, Carolyn M.

    2013-01-01

    By virtue of its unique interactions with kidney cells, lithium became an important research tool in renal physiology and pathophysiology. Investigators have uncovered the intricate relationships of lithium with the vasopressin and aldosterone systems, and the membrane channels or transporters regulated by them. While doing so, their work has also led to 1) questioning the role of adenylyl cyclase activity and prostaglandins in lithium-induced suppression of aquaporin-2 gene transcription; 2) unraveling the role of purinergic signaling in lithium-induced polyuria; and 3) highlighting the importance of the epithelial sodium channel (ENaC) in lithium-induced nephrogenic diabetes insipidus (NDI). Lithium-induced remodeling of the collecting duct has the potential to shed new light on collecting duct remodeling in disease conditions, such as diabetes insipidus. The finding that lithium inhibits glycogen synthase kinase-3β (GSK3β) has opened an avenue for studies on the role of GSK3β in urinary concentration, and GSK isoforms in renal development. Finally, proteomic and metabolomic profiling of the kidney and urine in rats treated with lithium is providing insights into how the kidney adapts its metabolism in conditions such as acquired NDI and the multifactorial nature of lithium-induced NDI. This review provides state-of-the-art knowledge of lithium as a versatile tool for understanding the molecular physiology of the kidney, and a comprehensive view of how this tool is challenging some of our long-standing concepts in renal physiology, often with paradigm shifts, and presenting paradoxical situations in renal pathophysiology. In addition, this review points to future directions in research where lithium can lead the renal community. PMID:23408166

  14. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    Science.gov (United States)

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-02

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

  15. A versatile miniature bioreactor and its application to bioelectrochemistry studies.

    Science.gov (United States)

    Kloke, A; Rubenwolf, S; Bücking, C; Gescher, J; Kerzenmacher, S; Zengerle, R; von Stetten, F

    2010-08-15

    Often, reproducible investigations on bio-microsystems essentially require a flexible but well-defined experimental setup, which in its features corresponds to a bioreactor. We therefore developed a miniature bioreactor with a volume in the range of a few millilitre that is assembled by alternate stacking of individual polycarbonate elements and silicone gaskets. All the necessary supply pipes are incorporated as bore holes or cavities within the individual elements. Their combination allows for a bioreactor assembly that is easily adaptable in size and functionality to experimental demands. It allows for controlling oxygen transfer as well as the monitoring of dissolved oxygen concentration and pH-value. The system provides access for media exchange or sterile sampling. A mass transfer coefficient for oxygen (k(L)a) of 4.3x10(-3) s(-1) at a flow rate of only 15 ml min(-1) and a mixing time of 1.5s at a flow rate of 11 ml min(-1) were observed for the modular bioreactor. Single reactor chambers can be interconnected via ion-conductive membranes to form a two-chamber test setup for investigations on electrochemical systems such as fuel cells or sensors. The versatile applicability of this modular and flexible bioreactor was demonstrated by recording a growth curve of Escherichia coli (including monitoring of pH and oxygen) saturation, and also as by two bioelectrochemical experiments. In the first electrochemical experiment the use of the bioreactor enabled a direct comparison of electrode materials for a laccase-catalyzed oxygen reduction electrode. In a second experiment, the bioreactor was utilized to characterize the influence of outer membrane cytochromes on the performance of Shewanella oneidensis in a microbial fuel cell. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Phosphatidic acid, a versatile water-stress signal in roots

    Directory of Open Access Journals (Sweden)

    Fionn eMcLoughlin

    2013-12-01

    Full Text Available Adequate water supply is of utmost importance for growth and reproduction of plants. In order to cope with water deprivation, plants have to adapt their development and metabolism to ensure survival. To maximize water use efficiency, plants use a large array of signaling mediators such as hormones, protein kinases and phosphatases, Ca2+, reactive oxygen species and low abundant phospholipids that together form complex signaling cascades. Phosphatidic acid (PA is a signaling lipid that rapidly accumulates in response to a wide array of abiotic stress stimuli. PA formation provides the cell with spatial and transient information about the external environment by acting as a protein-docking site in cellular membranes. PA reportedly binds to a number of proteins that play a role during water limiting conditions, such as drought and salinity and has been shown to play an important role in maintaining root system architecture. Members of two osmotic stress-activated protein kinase families, sucrose non-fermenting 1-related protein kinase 2 (SnRK2 and mitogen activated protein kinases (MAPKs were recently shown bind PA and are also involved in the maintenance of root system architecture and salinity stress tolerance. In addition, PA regulates several proteins involved in abscisic acid (ABA-signaling. PA-dependent recruitment of glyceraldehyde-3-phosphate dehydrogenase (GAPDH under water limiting conditions indicates a role in regulating metabolic processes. Finally, a recent study also shows the PA recruits the clathrin heavy chain and a potassium channel subunit, hinting towards additional roles in cellular trafficking and potassium homeostasis. Taken together, the rapidly increasing number of proteins reported to interact with PA implies a broad role for this versatile signaling phospholipid in mediating salt and water stress responses.

  17. SCIMPI: A versatile seafloor observatory for changing environments

    Science.gov (United States)

    Moran, K.; Lado Insua, T.; Kulin, I.; Farrington, S.; Newman, J.

    2011-12-01

    The Simple Cabled Instrument for Measuring Parameters In-situ (SCIMPI) is a new seafloor observatory instrument. SCIMPI is designed to take subsurface time series measurements of temperature, pressure and resistivity in the sub-seafloor. This instrument has a battery operational life of approximately two years, which can be replaced with a battery pack using a remotely-operated vehicle, and provides high resolution measurements of physical properties in the sediment. With either periodic battery replacement or connection to a fiber-optic cable, SCIMPI is a long-term observatory for understanding sub-seafloor dynamics. The main advantage of this system is the reduced equipment and installation requirements making this tool an affordable and versatile system for scientific research. The pressure and temperature sensors, integrated into the system, have been successfully used in other marine industrial and scientific applications. Its electrical resistivity sensor, casing, and array assembly are uniquely designed and can be adapted for each mission. SCIMPI is currently in its last phase of testing prior to deployment in an Integrated Ocean Drilling Program borehole. This first SCIMPI is designed for a water depth of 1000 m and a sediment depth up to ~300 m below seafloor. But future assemblies can be tailored for deeper conditions and environments. Here we present the SCIMPI design, deployment options, and its scientific potential in a long-term ocean observatory. Science applications include studies of fluid flow, hydrate formation, and seismically induced pore pressure changes. The cost of this instrument will enable these measurements to become more commonplace, thereby improving our temporal and spatial knowledge of sub-seafloor gas, fluid and pore pressure activity. Most notable of the target deployments for SCIMPI are sub-seafloor gas hydrate sites and sites with biogenic methane. Understanding the dynamics of methane's role in the oceans as climate change

  18. Lipoproteins of Bacterial Pathogens▿

    Science.gov (United States)

    Kovacs-Simon, A.; Titball, R. W.; Michell, S. L.

    2011-01-01

    Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases. PMID:20974828

  19. Considerations on bacterial nucleoids.

    Science.gov (United States)

    Feijoo-Siota, Lucía; Rama, José Luis R; Sánchez-Pérez, Angeles; Villa, Tomás G

    2017-07-01

    The classic genome organization of the bacterial chromosome is normally envisaged with all its genetic markers linked, thus forming a closed genetic circle of duplex stranded DNA (dsDNA) and several proteins in what it is called as "the bacterial nucleoid." This structure may be more or less corrugated depending on the physiological state of the bacterium (i.e., resting state or active growth) and is not surrounded by a double membrane as in eukayotic cells. The universality of the closed circle model in bacteria is however slowly changing, as new data emerge in different bacterial groups such as in Planctomycetes and related microorganisms, species of Borrelia, Streptomyces, Agrobacterium, or Phytoplasma. In these and possibly other microorganisms, the existence of complex formations of intracellular membranes or linear chromosomes is typical; all of these situations contributing to weakening the current cellular organization paradigm, i.e., prokaryotic vs eukaryotic cells.

  20. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the benefits......, but the identity and significance of interspecies bacterial interactions is neglected in these analyses. There is therefore an urgent need for bridging the gap between metagenomic analysis and in vitro models suitable for studies of bacterial interactions.Bacterial interactions and coadaptation are important...... at the microscale of complex communities, including biofilms.Studies of multispecies biofilms and the interactions shaping these are conducted in traditional approaches used for single-species biofilms with some adjustments; but a crucial point for consideration is which strains to combine and where these should...

  1. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  2. Bacterial blight of cotton

    Directory of Open Access Journals (Sweden)

    Aïda JALLOUL

    2015-04-01

    Full Text Available Bacterial blight of cotton (Gossypium ssp., caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1 the genetic basis for plant resistance and bacterial virulence, (2 physiological mechanisms involved in the hypersensitive response to the pathogen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3 control of the disease.

  3. Bacterial meningitis in infants.

    Science.gov (United States)

    Ku, Lawrence C; Boggess, Kim A; Cohen-Wolkowiez, Michael

    2015-03-01

    Neonatal bacterial meningitis is uncommon but devastating. Morbidity among survivors remains high. The types and distribution of pathogens are related to gestational age, postnatal age, and geographic region. Confirming the diagnosis is difficult. Clinical signs are often subtle, lumbar punctures are frequently deferred, and cerebrospinal fluid (CSF) cultures can be compromised by prior antibiotic exposure. Infants with bacterial meningitis can have negative blood cultures and normal CSF parameters. Promising tests such as the polymerase chain reaction require further study. Prompt treatment with antibiotics is essential. Clinical trials investigating a vaccine for preventing neonatal Group B Streptococcus infections are ongoing. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Fast, versatile, and non-destructive biscuit inspection system using spectral imaging

    DEFF Research Database (Denmark)

    Carstensen, Jens Michael

    2017-01-01

    A fast, versatile, and non-destructive method for assessing biscuit quality is presented. The method integrates color (or browning) measurement, moisture assessment, compositional and dimensional measurements on a spectral imaging platform using the silicon range 400–1000 nm.......A fast, versatile, and non-destructive method for assessing biscuit quality is presented. The method integrates color (or browning) measurement, moisture assessment, compositional and dimensional measurements on a spectral imaging platform using the silicon range 400–1000 nm....

  5. Versatile and Tunable Transparent Conducting Electrodes Based on Doped Graphene

    KAUST Repository

    Mansour, Ahmed E.

    2016-11-25

    , the conductivity increases compared modestly to intercalation as the electron transfer is limited to the uppermost graphene layers. Finally, a novel and universal multi-modal doping strategy is developed, thanks to the unique platform offered by FLG, where surface and intercalation doping are combined to mutually achieve high conductivity with an extended tunability of the work function. This work presents doped-FLG as a prospective and versatile candidate among emerging TCEs, given the need for efficient and stable doping routes capable of controllably tuning its properties to meet the criteria of a broad range of applications.

  6. Versatile and Resilient Hydrogen-Bonded Host Frameworks.

    Science.gov (United States)

    Adachi, Takuji; Ward, Michael D

    2016-12-20

    Low-density molecular host frameworks, whether equipped with persistent molecular-scale pores or virtual pores that are sustainable only when occupied by guest molecules, have emerged as a promising class of materials owing to the ability to tailor the size, geometry, and chemical character of their free space through the versatility of organic synthesis. As such, molecular frameworks are promising candidates for storage, separations of commodity and fine chemicals, heterogeneous catalysis, and optical and electronic materials. Frameworks assembled through hydrogen bonds, though generally not stable toward collapse in the absence of guests, promise significant chemical and structural diversity, with pores that can be tailored for a wide range of guest molecules. The utility of these frameworks, however, depends on the resilience of n-dimensional hydrogen-bonded motifs that serve as reliable building blocks so that the molecular constituents can be manipulated without disruption of the anticipated global solid-state architecture. Though many hydrogen-bonded frameworks have been reported, few exist that are amenable to systematic modification, thus limiting the design of functional materials. This Account reviews discoveries in our laboratory during the past decade related to a series of host frameworks based on guanidinium cations and interchangeable organosulfonate anions, in which the 3-fold symmetry and hydrogen-bonding complementarity of these ions prompt the formation of a two-dimensional (2-D) quasi-hexagonal hydrogen-bonding network that has proven to be remarkably resilient toward the introduction of a wide range of organic pendant groups attached to the sulfonate. Since an earlier report in this journal that focused primarily on organodisulfonate host frameworks with lamellar architectures, this unusually persistent network has afforded an unparalleled range of framework architectures and hundreds of new crystalline materials with predictable solid

  7. Structural and evolutionary versatility in protein complexes with uneven stoichiometry.

    Science.gov (United States)

    Marsh, Joseph A; Rees, Holly A; Ahnert, Sebastian E; Teichmann, Sarah A

    2015-03-16

    Proteins assemble into complexes with diverse quaternary structures. Although most heteromeric complexes of known structure have even stoichiometry, a significant minority have uneven stoichiometry--that is, differing numbers of each subunit type. To adopt this uneven stoichiometry, sequence-identical subunits must be asymmetric with respect to each other, forming different interactions within the complex. Here we first investigate the occurrence of uneven stoichiometry, demonstrating that it is common in vitro and is likely to be common in vivo. Next, we elucidate the structural determinants of uneven stoichiometry, identifying six different mechanisms by which it can be achieved. Finally, we study the frequency of uneven stoichiometry across evolution, observing a significant enrichment in bacteria compared with eukaryotes. We show that this arises due to a general increased tendency for bacterial proteins to self-assemble and form homomeric interactions, even within the context of a heteromeric complex.

  8. BACTERIAL WATERBORNE PATHOGENS

    Science.gov (United States)

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  9. Bacterial Infections - Multiple Languages

    Science.gov (United States)

    ... Know - Af-Soomaali (Somali) PDF Centers for Disease Control and Prevention Spanish (español) Expand Section Bacterial Infections: MedlinePlus Health Topic - English Infecciones bacterianas: Tema de salud de MedlinePlus - español (Spanish) ...

  10. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  11. Formation of manganese oxides by bacterially generated superoxide

    Science.gov (United States)

    Learman, D. R.; Voelker, B. M.; Vazquez-Rodriguez, A. I.; Hansel, C. M.

    2011-02-01

    Manganese oxide minerals are among the strongest sorbents and oxidants in the environment. The formation of these minerals controls the fate of contaminants, the degradation of recalcitrant carbon, the cycling of nutrients and the activity of anaerobic-based metabolisms. Oxidation of soluble manganese(II) ions to manganese(III/IV) oxides has been primarily attributed to direct enzymatic oxidation by microorganisms. However, the physiological reason for this process remains unknown. Here we assess the ability of a common species of marine bacteria-Roseobacter sp. AzwK-3b-to oxidize manganese(II) in the presence of chemical and biological inhibitors. We show that Roseobacter AzwK-3b oxidizes manganese(II) by producing the strong and versatile redox reactant superoxide. The oxidation of manganese(II), and concomitant production of manganese oxides, was inhibited in both the light and dark in the presence of enzymes and metals that scavenge superoxide. Oxidation was also inhibited by various proteases, enzymes that break down bacterial proteins, confirming that the superoxide was bacterially generated. We conclude that bacteria can oxidize manganese(II) indirectly, through the enzymatic generation of extracellular superoxide radicals. We suggest that dark bacterial production of superoxide may be a driving force in metal cycling and mineralization in the environment.

  12. A versatile and interoperable network sensors for water resources monitoring

    Science.gov (United States)

    Ortolani, Alberto; Brandini, Carlo; Costantini, Roberto; Costanza, Letizia; Innocenti, Lucia; Sabatini, Francesco; Gozzini, Bernardo

    2010-05-01

    Monitoring systems to assess water resources quantity and quality require extensive use of in-situ measurements, that have great limitations like difficulties to access and share data, and to customise and easy reconfigure sensors network to fulfil end-users needs during monitoring or crisis phases. In order to address such limitations Sensor Web Enablement technologies for sensors management have been developed and applied to different environmental context under the EU-funded OSIRIS project (Open architecture for Smart and Interoperable networks in Risk management based on In-situ Sensors, www.osiris-fp6.eu). The main objective of OSIRIS was to create a monitoring system to manage different environmental crisis situations, through an efficient data processing chain where in-situ sensors are connected via an intelligent and versatile network infrastructure (based on web technologies) that enables end-users to remotely access multi-domain sensors information. Among the project application, one was focused on underground fresh-water monitoring and management. With this aim a monitoring system to continuously and automatically check water quality and quantity has been designed and built in a pilot test, identified as a portion of the Amiata aquifer feeding the Santa Fiora springs (Grosseto, Italy). This aquifer present some characteristics that make it greatly vulnerable under some conditions. It is a volcanic aquifer with a fractured structure. The volcanic nature in Santa Fiora causes levels of arsenic concentrations that normally are very close to the threshold stated by law, but that sometimes overpass such threshold for reasons still not fully understood. The presence of fractures makes the infiltration rate very inhomogeneous from place to place and very high in correspondence of big fractures. In case of liquid-pollutant spills (typically hydrocarbons spills from tanker accidents or leakage from house tanks containing fuel for heating), these fractures can act

  13. Bacterial Genome Instability

    Science.gov (United States)

    Darmon, Elise

    2014-01-01

    SUMMARY Bacterial genomes are remarkably stable from one generation to the next but are plastic on an evolutionary time scale, substantially shaped by horizontal gene transfer, genome rearrangement, and the activities of mobile DNA elements. This implies the existence of a delicate balance between the maintenance of genome stability and the tolerance of genome instability. In this review, we describe the specialized genetic elements and the endogenous processes that contribute to genome instability. We then discuss the consequences of genome instability at the physiological level, where cells have harnessed instability to mediate phase and antigenic variation, and at the evolutionary level, where horizontal gene transfer has played an important role. Indeed, this ability to share DNA sequences has played a major part in the evolution of life on Earth. The evolutionary plasticity of bacterial genomes, coupled with the vast numbers of bacteria on the planet, substantially limits our ability to control disease. PMID:24600039

  14. Carbohydrate mediated bacterial adhesion.

    Science.gov (United States)

    Pieters, Roland J

    2011-01-01

    In the process of adhesion, bacteria often carry proteins on their surface, adhesins, that bind to specific components of tissue cells or the extracellular matrix. In many cases these components are carbohydrate structures. The carbohydrate binding specificities of many bacteria have been uncovered over the years. The design and synthesis of inhibitors of bacterial adhesion has the potential to create new therapeutics for the prevention and possibly treatment of bacterial infections. Unfortunately, the carbohydrate structures often bind only weakly to the adhesion proteins, although drug design approaches can improve the situation. Furthermore, in some cases linking carbohydrates covalently together, to create so-called multivalent systems, can also significantly enhance the inhibitory potency. Besides adhesion inhibition as a potential therapeutic strategy, the adhesion proteins can also be used for detection. Novel methods to do this are being developed. These include the use of microarrays and glyconanoparticles. New developments in these areas are discussed.

  15. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... treatment for ABM should not be based exclusively on clinical notification systems with possible unbalanced under-reporting....

  16. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  17. Adaptive Bacterial Foraging Optimization

    OpenAIRE

    Hanning Chen; Yunlong Zhu; Kunyuan Hu

    2011-01-01

    Bacterial Foraging Optimization (BFO) is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how ...

  18. Bacterial transformation of terpenoids

    Science.gov (United States)

    Grishko, V. V.; Nogovitsina, Y. M.; Ivshina, I. B.

    2014-04-01

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references.

  19. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references.

  20. Combing bacterial turbulence.

    Science.gov (United States)

    Sokolov, Andrey; Nishiguchi, Daiki; Aronson, Igor

    Living systems represented by ensembles of motile organisms demonstrate a transition from a chaotic motion to a highly ordered state. Examples of such living systems include suspensions of bacteria, schools of fish, flocks of birds and even crowds of people. In spite of significant differences in interacting mechanisms and motion scales, ordered living systems have many similarities: short-range alignment of organism, turbulent-like motion, emergence of large-scale flows and dynamic vortices. In this work, we rectify a turbulent dynamics in suspensions of swimming bacteria Bacillus subtilis by imposing periodical constraints on bacterial motion. Bacteria, swimming between periodically placed microscopic vertical pillars, may self-organize in a stable lattice of vortices. We demonstrate the emergence of a strong anti-ferromagnetic order of bacterial vortices in a rectangular lattice of pillars. Hydrodynamic interaction between vortices increases the stability of an emerged pattern. The highest stability of vortices in the anti-ferromagnetic lattice and the fastest vortices speed were observed in structures with the periods comparable with a correlation length of bacterial unconstrained motion. A.S and I.A were supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science And Engineering, under contract No. DE AC02-06CH11357 and D.N was supported by ALPS and JSPS Grant No. 26-9915.

  1. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  2. Versatile use of vacuum-assisted healing in fifty patients

    Science.gov (United States)

    Al Fadhli, Ahmad; Alexander, George; Kanjoor, James Roy

    2009-01-01

    Context: Wound management can often be a challenging experience, especially in the presence of diabetes mellitus, vascular or immunological compromise. While no single technique can be considered by itself to be ideal, vacuum-assisted healing, which is a recent innovation, is fast becoming a necessary addition as adjuvant therapy to hasten wound healing. Aims: To determine the efficacy of vacuum-assisted healing. Settings and Design: Plastic surgery centre. Ministry of Health Hospital, Kuwait. Materials and Methods: Patients from Kuwait in a wide variety of clinical situations were chosen for study: Patients (n=50) were classified by diagnosis: Group 1: pressure sore- sacral (n= 3), trochanteric (n=6), ischial (n= 2); Group 2: ulcers (n= 11); Group 3: traumatic soft tissue wounds (n =15); Group 4: extensive tissue loss from the abdominal wall perineum, thigh and axilla (n =5); Group 5: sternal dehiscence wounds (n =4) and Group 6: wounds from flap necrosis (n =4). All wounds were subjected to vacuum by wall unit or portable unit, using pressure of 100-125 mm - continuous or intermittent. Closure of wounds, significant reduction in size and refusal by patient for continuation of vacuum-assisted closure therapy were end points of vacuum application. Results: Sixteen per cent of patients showed complete healing of the wound. Seventy per cent of patients showed 20-78% reduction in wound size. In 14% of patients treatment had to be discontinued. All patients showed improvement in granulation tissue and reduction in bacterial isolates and tissue oedema. Conclusions: The application of subatmospheric pressure or negative pressure promotes healing in a wide range of clinical settings and is an advanced wound healing therapy that can optimize patient care, promote rapid wound healing and help manage costs. It may be used in most instances in both hospital and community settings. PMID:20368850

  3. Versatile use of vacuum-assisted healing in fifty patients

    Directory of Open Access Journals (Sweden)

    Al Fadhli Ahmad

    2009-01-01

    Full Text Available Context: Wound management can often be a challenging experience, especially in the presence of diabetes mellitus, vascular or immunological compromise. While no single technique can be considered by itself to be ideal, vacuum-assisted healing, which is a recent innovation, is fast becoming a necessary addition as adjuvant therapy to hasten wound healing. Aims: To determine the efficacy of vacuum-assisted healing. Settings and Design: Plastic surgery centre. Ministry of Health Hospital, Kuwait. Materials and Methods: Patients from Kuwait in a wide variety of clinical situations were chosen for study: Patients (n=50 were classified by diagnosis: Group 1: pressure sore- sacral (n= 3, trochanteric (n=6, ischial (n= 2; Group 2: ulcers (n= 11; Group 3: traumatic soft tissue wounds (n =15; Group 4: extensive tissue loss from the abdominal wall perineum, thigh and axilla (n =5; Group 5: sternal dehiscence wounds (n =4 and Group 6: wounds from flap necrosis (n =4. All wounds were subjected to vacuum by wall unit or portable unit, using pressure of 100-125 mm - continuous or intermittent. Closure of wounds, significant reduction in size and refusal by patient for continuation of vacuum-assisted closure therapy were end points of vacuum application. Results: Sixteen per cent of patients showed complete healing of the wound. Seventy per cent of patients showed 20-78% reduction in wound size. In 14% of patients treatment had to be discontinued. All patients showed improvement in granulation tissue and reduction in bacterial isolates and tissue oedema. Conclusions: The application of subatmospheric pressure or negative pressure promotes healing in a wide range of clinical settings and is an advanced wound healing therapy that can optimize patient care, promote rapid wound healing and help manage costs. It may be used in most instances in both hospital and community settings.

  4. A Versatile Star PEG Grafting Method for the Generation of Nonfouling and Nonthrombogenic Surfaces

    Science.gov (United States)

    Thalla, Pradeep Kumar; Contreras-García, Angel; Fadlallah, Hicham; Barrette, Jérémie; De Crescenzo, Gregory; Merhi, Yahye; Lerouge, Sophie

    2013-01-01

    Polyethylene glycol (PEG) grafting has a great potential to create nonfouling and nonthrombogenic surfaces, but present techniques lack versatility and stability. The present work aimed to develop a versatile PEG grafting method applicable to most biomaterial surfaces, by taking advantage of novel primary amine-rich plasma-polymerized coatings. Star-shaped PEG covalent binding was studied using static contact angle, X-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance with dissipation monitoring (QCM-D). Fluorescence and QCM-D both confirmed strong reduction of protein adsorption when compared to plasma-polymerized coatings and pristine poly(ethyleneterephthalate) (PET). Moreover, almost no platelet adhesion was observed after 15 min perfusion in whole blood. Altogether, our results suggest that primary amine-rich plasma-polymerized coatings offer a promising stable and versatile method for PEG grafting in order to create nonfouling and nonthrombogenic surfaces and micropatterns. PMID:23509823

  5. A Versatile Star PEG Grafting Method for the Generation of Nonfouling and Nonthrombogenic Surfaces

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Thalla

    2013-01-01

    Full Text Available Polyethylene glycol (PEG grafting has a great potential to create nonfouling and nonthrombogenic surfaces, but present techniques lack versatility and stability. The present work aimed to develop a versatile PEG grafting method applicable to most biomaterial surfaces, by taking advantage of novel primary amine-rich plasma-polymerized coatings. Star-shaped PEG covalent binding was studied using static contact angle, X-ray photoelectron spectroscopy (XPS, and quartz crystal microbalance with dissipation monitoring (QCM-D. Fluorescence and QCM-D both confirmed strong reduction of protein adsorption when compared to plasma-polymerized coatings and pristine poly(ethyleneterephthalate (PET. Moreover, almost no platelet adhesion was observed after 15 min perfusion in whole blood. Altogether, our results suggest that primary amine-rich plasma-polymerized coatings offer a promising stable and versatile method for PEG grafting in order to create nonfouling and nonthrombogenic surfaces and micropatterns.

  6. Controlled Electrochemical Carboxylation of Graphene To Create a Versatile Chemical Platform for Further Functionalization

    DEFF Research Database (Denmark)

    Bjerglund Pedersen, Emil; Kongsfelt, Mikkel S.; Shimizu, Kyoko

    An electrochemical approach is introduced for the versatile carboxylation of multilayered graphene in 0.1 M Bu4NBF4/MeCN. First, the graphene substrate is negatively charged at −1.9 V vs. Ag/AgI to allow for intercalation of Bu4N+. In the second step, the strongly activated and nucleophilic graph...... in a multi-layered but expanded structure accessible for functionalization. On a more general level, this approach will provide a versatile way of forming new hybrid materials based on intimate bond coupling to graphene via carboxylate groups....

  7. Versatility of nasolabial flaps for the management of severe trismus in oral submucous fibrosis

    Directory of Open Access Journals (Sweden)

    S M Balaji

    2016-01-01

    Conclusion: The nasolabial flap is a versatile flap, which can be successfully used in the reconstruction of defects created after the release of fibrotic bands in OSMF. The versatility of the nasolabial flap has been attributed to its reliable vascularity derived from numerous vessels in the vicinity. Major advantage is the ease of elevation, proximity to the defect, suitable size for coverage of defect, minimal swallowing and speech difficulties, and a relatively cosmetic result as scar is in natural crease. All the cases treated for OSMF using bilateral nasolabial flaps showed adequate mouth opening at 2-year follow-up postoperatively, recommending its use.

  8. Versatile Chemical Derivatizations to Design Glycol Chitosan-Based Drug Carriers

    Directory of Open Access Journals (Sweden)

    Sung Eun Kim

    2017-10-01

    Full Text Available Glycol chitosan (GC and its derivatives have been extensively investigated as safe and effective drug delivery carriers because of their unique physiochemical and biological properties. The reactive functional groups such as the amine and hydroxyl groups on the GC backbone allow for easy chemical modification with various chemical compounds (e.g., hydrophobic molecules, crosslinkers, and acid-sensitive and labile molecules, and the versatility in chemical modifications enables production of a wide range of GC-based drug carriers. This review summarizes the versatile chemical modification methods that can be used to design GC-based drug carriers and describes their recent applications in disease therapy.

  9. Radiology of bacterial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  10. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  11. Animal Models of Bacterial Keratitis

    Science.gov (United States)

    Marquart, Mary E.

    2011-01-01

    Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades. PMID:21274270

  12. Animal Models of Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Mary E. Marquart

    2011-01-01

    Full Text Available Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades.

  13. A brilliant sandwich type fluorescent nanostructure incorporating a compact quantum dot layer and versatile silica substrates.

    Science.gov (United States)

    Huang, Liang; Wu, Qiong; Wang, Jing; Foda, Mohamed; Liu, Jiawei; Cai, Kai; Han, Heyou

    2014-03-18

    A "hydrophobic layer in silica" structure was designed to integrate a compact quantum dot (QD) layer with high quantum yield into scalable silica hosts containing desired functionality. This was based on metal affinity driven assembly of hydrophobic QDs with versatile silica substrates and homogeneous encapsulation of organosilica/silica layers.

  14. A compact versatile matrix converter to integrate various energy resources to utility network

    DEFF Research Database (Denmark)

    Liu, Xiong; Loh, Poh Chiang; Wang, Peng

    2011-01-01

    This paper proposes a multi-inputs versatile matrix converter (VMC) to integrate various energy resources and energy storages to a power grid. The VMC is developed based on a traditional indirect matrix converter (IMC) and a nineswitch converter. The six input terminals provide flexibility...

  15. BODIPY-phosphane as a versatile tool for easy access to new metal-based theranostics

    NARCIS (Netherlands)

    Tasan, Semra; Zava, Olivier; Bertrand, Benoit; Bernhard, Claire; Goze, Christine; Picquet, Michel; Le Gendre, Pierre; Harvey, Pierre; Denat, Franck; Casini, Angela; Bodio, Ewen

    2013-01-01

    A new BODIPY-phosphane was synthesized and proved to be a versatile tool for imaging organometallic complexes. It also led to easy access to a new family of theranostics, featuring gold, ruthenium and osmium complexes. The compounds' cytotoxicity was tested on cancer cells, and their cell uptake was

  16. A facile and versatile approach to biocompatible "fluorescent polymers" from polymerizable carbon nanodots.

    Science.gov (United States)

    Zhang, Peng; Li, Wenchen; Zhai, Xinyun; Liu, Changjun; Dai, Liming; Liu, Wenguang

    2012-10-28

    Highly fluorescent polymerizable carbon nanodots (PCNDs), synthesized by microwave assisted pyrolysis and subsequent surface vinylation, were copolymerized with several model monomers to form different functional fluorescent polymeric materials in solution or the solid-state, indicating a simple and versatile approach to novel fluorescent polymer materials.

  17. Origami: A Versatile Modeling System for Visualising Chemical Structure and Exploring Molecular Function

    Science.gov (United States)

    Davis, James; Leslie, Ray; Billington, Susan; Slater, Peter R.

    2010-01-01

    The use of "Origami" is presented as an accessible and transferable modeling system through which to convey the intricacies of molecular shape and highlight structure-function relationships. The implementation of origami has been found to be a versatile alternative to conventional ball-and-stick models, possessing the key advantages of being both…

  18. 1-Isocyano-2-dimethylamino-alkenes: Versatile reagents in diversity-oriented organic synthesis

    NARCIS (Netherlands)

    Dömling, Alexander; Illgen, Katrin

    2005-01-01

    1-Isocyano-2-dimethylamino-alkenes are versatile and multifunctional reagents in organic synthesis. Two useful protocols are given for multicomponent reactions (MCRs) for the assembly of a 6-oxo-1,4,5,6-tetrahydropyrazine-2- carboxylic acid methyl ester derivative and a highly substituted thiazole.

  19. Versatile Scope of a Masked Aldehyde Nitrone in 1,3-Dipolar Cycloadditions

    NARCIS (Netherlands)

    Hoogenboom, Jorin; Zuilhof, Han; Wennekes, Tom

    2015-01-01

    A new masked aldehyde-containing nitrone 1 that is easily available through a facile one-step procedure has been developed. It undergoes a [3 + 2]-thermal cycloaddition with a wide range of dipolarophiles, affording isoxazolidine cycloadducts that are suitable for versatile postcycloaddition

  20. Fast, versatile x-ray fluorescence method for measuring tin in impregnated wood

    DEFF Research Database (Denmark)

    Drabæk, I.; Christensen, Leif Højslet

    1985-01-01

    The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples...

  1. The Development and Validation of the Leadership Versatility Index for Students (LVI-S)

    Science.gov (United States)

    Yarborough, J. Preston

    2011-01-01

    According to Bass' (1990) summary of fifty years of research and nearly thirty dichotomy-based theories, leaders influence people through autocratic use of power (task-oriented) or through democratic use of power (people-oriented). Each style produces unique tensions and tradeoffs, but versatile leaders can incorporate strategies from both sides…

  2. Versatile laser microfabrication techniques for lab-on-chip devices in ...

    Indian Academy of Sciences (India)

    2014-02-06

    Feb 6, 2014 ... the process of hastening and reagent consumption as the basis for fabrication. This paper discusses three versatile techniques, viz. laser direct writing in conjunction with soft lithography, laser micropatterning, followed by HF etching and micromilling for the fabrication of microfluidic chips to be used in ...

  3. Management by Objective and Its Formal Performance Appraisal: A Versatile Tool of Management.

    Science.gov (United States)

    Chen, Donna; Peterson, Lorna

    This paper discusses the utility, versatility, and pros and cons of the formal performance appraisal as one of the tools of management by objectives (MBO). Rather than rating the traits of an employee, performance appraisal based on MBO rates an employee's achievements toward both his professional goals and institutional goals. The paper outlines…

  4. Biosensors of bacterial cells.

    Science.gov (United States)

    Burlage, Robert S; Tillmann, Joshua

    2017-07-01

    Biosensors are devices which utilize both an electrical component (transducer) and a biological component to study an environment. They are typically used to examine biological structures, organisms and processes. The field of biosensors has now become so large and varied that the technology can often seem impenetrable. Yet the principles which underlie the technology are uncomplicated, even if the details of the mechanisms are elusive. In this review we confine our analysis to relatively current advancements in biosensors for the detection of whole bacterial cells. This includes biosensors which rely on an added labeled component and biosensors which do not have a labeled component and instead detect the binding event or bound structure on the transducer. Methods to concentrate the bacteria prior to biosensor analysis are also described. The variety of biosensor types and their actual and potential uses are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Bacterial microsystems and microrobots.

    Science.gov (United States)

    Martel, Sylvain

    2012-12-01

    Microorganisms and specifically motile bacteria have been recently added to the list of micro-actuators typically considered for the implementation of microsystems and microrobots. Such trend has been motivated by the fact these microorganisms are self-powered actuators with overall sizes at the lower end of the micrometer range and which have proven to be extremely effective in low Reynolds number hydrodynamic regime of usually less than 10(-2). Furthermore, the various sensors or taxes in bacteria influencing their movements can also be exploited to perform tasks that were previously considered only for futuristic artificial microrobots. Bacterial implementations and related issues are not only reviewed, but this paper also proposes many techniques and approaches that can be considered as building blocks for the implementations of more sophisticated microsystems and microrobots.

  6. Anaerobes in bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Aggarwal A

    2003-01-01

    Full Text Available Four hundred high vaginal swabs were taken from patients attending gynaecology and obstetrics department of Govt. medical college, Amritsar. The patients were divided into four groups i.e. women in pregnancy (Group I, in labour/post partum (Group II, with abnormal vaginal discharge or bacterial vaginosis (Group III and asymptomatic women as control (Group IV. Anaerobic culture of vaginal swabs revealed that out of 400 cases, 212(53% were culture positive. Maximum isolation of anaerobes was in group III (84% followed by group II (56%, group I (36% and control group (15%. Gram positive anaerobes (69.2% out numbered gram negatives (30.8%. Among various isolates Peptostreptococcus spp. and Bacteroides spp. were predominant.

  7. Current and Past Strategies for Bacterial Culture in Clinical Microbiology

    Science.gov (United States)

    Lagier, Jean-Christophe; Edouard, Sophie; Pagnier, Isabelle; Mediannikov, Oleg; Drancourt, Michel

    2015-01-01

    SUMMARY A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome. PMID:25567228

  8. Current and past strategies for bacterial culture in clinical microbiology.

    Science.gov (United States)

    Lagier, Jean-Christophe; Edouard, Sophie; Pagnier, Isabelle; Mediannikov, Oleg; Drancourt, Michel; Raoult, Didier

    2015-01-01

    A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Diversity and Assembling Processes of Bacterial Communities in Cryoconite Holes of a Karakoram Glacier.

    Science.gov (United States)

    Ambrosini, Roberto; Musitelli, Federica; Navarra, Federico; Tagliaferri, Ilario; Gandolfi, Isabella; Bestetti, Giuseppina; Mayer, Christoph; Minora, Umberto; Azzoni, Roberto Sergio; Diolaiuti, Guglielmina; Smiraglia, Claudio; Franzetti, Andrea

    2017-05-01

    Cryoconite holes are small ponds that form on the surface of glaciers that contain a dark debris, the cryoconite, at the bottom and host active ecological communities. Differences in the structure of bacterial communities have been documented among Arctic and mountain glaciers, and among glaciers in different areas of the world. In this study, we investigated the structure of bacterial communities of cryoconite holes of Baltoro Glacier, a large (62 km in length and 524 km2 of surface) glacier of the Karakoram, by high-throughput sequencing of the V5-V6 hypervariable regions of the 16S rRNA gene. We found that Betaproteobacteria dominated bacterial communities, with large abundance of genera Polaromonas, probably thanks to its highly versatile metabolism, and Limnohabitans, which may have been favoured by the presence of supraglacial lakes in the area where cryoconite holes were sampled. Variation in bacterial communities among different sampling areas of the glacier could be explained by divergent selective processes driven by variation in environmental conditions, particularly pH, which was the only environmental variable that significantly affected the structure of bacterial communities. This variability may be due to both temporal and spatial patterns of variation in environmental conditions.

  10. Bacteriële meningitis

    NARCIS (Netherlands)

    Brouwer, M. C.; van de Beek, D.

    2012-01-01

    Bacterial meningitis is a severe disease which affects 35.000 Europeans each year and has a mortality rate of about 20%. During the past 25 years the epidemiology of bacterial meningitis has changed significantly due to the implementation of vaccination against Haemophilus influenzae, Neisseria

  11. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  12. Adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements.

    Science.gov (United States)

    Richard, D; Ravigné, V; Rieux, A; Facon, B; Boyer, C; Boyer, K; Grygiel, P; Javegny, S; Terville, M; Canteros, B I; Robène, I; Vernière, C; Chabirand, A; Pruvost, O; Lefeuvre, P

    2017-04-01

    Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated with mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family. © 2017 John Wiley & Sons Ltd.

  13. Illumination of growth, division and secretion by metabolic labeling of the bacterial cell surface

    Science.gov (United States)

    Siegrist, M. Sloan; Swarts, Benjamin M.; Fox, Douglas M.; Lim, Shion An; Bertozzi, Carolyn R.

    2015-01-01

    The cell surface is the essential interface between a bacterium and its surroundings. Composed primarily of molecules that are not directly genetically encoded, this highly dynamic structure accommodates the basic cellular processes of growth and division as well as the transport of molecules between the cytoplasm and the extracellular milieu. In this review, we describe aspects of bacterial growth, division and secretion that have recently been uncovered by metabolic labeling of the cell envelope. Metabolite derivatives can be used to label a variety of macromolecules, from proteins to non-genetically-encoded glycans and lipids. The embedded metabolite enables precise tracking in time and space, and the versatility of newer chemoselective detection methods offers the ability to execute multiple experiments concurrently. In addition to reviewing the discoveries enabled by metabolic labeling of the bacterial cell envelope, we also discuss the potential of these techniques for translational applications. Finally, we offer some guidelines for implementing this emerging technology. PMID:25725012

  14. Zoonotic bacterial meningitis in human adults

    NARCIS (Netherlands)

    van Samkar, Anusha; Brouwer, Matthijs C.; van der Ende, Arie; van de Beek, Diederik

    2016-01-01

    To describe the epidemiology, etiology, clinical characteristics, treatment, outcome, and prevention of zoonotic bacterial meningitis in human adults. We identified 16 zoonotic bacteria causing meningitis in adults. Zoonotic bacterial meningitis is uncommon compared to bacterial meningitis caused by

  15. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  16. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  17. Adjunctive Therapies for Bacterial Keratitis.

    Science.gov (United States)

    Dakhil, Turki Abdulaziz Bin; Stone, Donald U; Gritz, David C

    2017-01-01

    Bacterial keratitis is the most common type among all types of infectious keratitis. Currently, antibiotics are the main-stay of treatment. The objective of this systematic review is to review published clinical studies which discuss the adjunctive treatment of bacterial keratitis to guide clinical decision-making. We reviewed the role of a variety of medications and surgeries which can help in managing bacterial keratitis complications, which include as thinning, perforation, and impaired wound healing. We have included appropriate animal and laboratory studies, case reports and case series, and randomized clinical trials regarding each therapy.

  18. Structural Genomics of Bacterial Virulence Factors

    National Research Council Canada - National Science Library

    Liddington, Robert

    2004-01-01

    We are applying a comprehensive yet focused structural genomics approach to determine the atomic resolution crystal structures of key bacterial virulence factors from high priority bacterial pathogens...

  19. Molecular detection of human bacterial pathogens

    National Research Council Canada - National Science Library

    Liu, Dongyou

    2011-01-01

    .... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...

  20. AQUA Cloning: A Versatile and Simple Enzyme-Free Cloning Approach.

    Directory of Open Access Journals (Sweden)

    Hannes M Beyer

    Full Text Available Assembly cloning is increasingly replacing conventional restriction enzyme and DNA-ligase-dependent cloning methods for reasons of efficiency and performance. Here, we describe AQUA (advanced quick assembly, a simple and versatile seamless assembly cloning approach. We demonstrate the applicability and versatility of AQUA Cloning in selected proof-of-principle applications including targeted insertion-, deletion- and site-directed point-mutagenesis, and combinatorial cloning. Furthermore, we show the one pot de novo assembly of multiple DNA fragments into a single circular plasmid encoding a complex light- and chemically-regulated Boolean A NIMPLY B logic operation. AQUA Cloning harnesses intrinsic in vivo processing of linear DNA fragments with short regions of homology of 16 to 32 bp mediated by Escherichia coli. It does not require any kits, enzymes or preparations of reagents and is the simplest assembly cloning protocol to date.

  1. Medicine, material science and security: the versatility of the coded-aperture approach.

    Science.gov (United States)

    Munro, P R T; Endrizzi, M; Diemoz, P C; Hagen, C K; Szafraniec, M B; Millard, T P; Zapata, C E; Speller, R D; Olivo, A

    2014-03-06

    The principal limitation to the widespread deployment of X-ray phase imaging in a variety of applications is probably versatility. A versatile X-ray phase imaging system must be able to work with polychromatic and non-microfocus sources (for example, those currently used in medical and industrial applications), have physical dimensions sufficiently large to accommodate samples of interest, be insensitive to environmental disturbances (such as vibrations and temperature variations), require only simple system set-up and maintenance, and be able to perform quantitative imaging. The coded-aperture technique, based upon the edge illumination principle, satisfies each of these criteria. To date, we have applied the technique to mammography, materials science, small-animal imaging, non-destructive testing and security. In this paper, we outline the theory of coded-aperture phase imaging and show an example of how the technique may be applied to imaging samples with a practically important scale.

  2. Draft genome sequence of Microbacterium oleivorans strain Wellendorf implicates heterotrophic versatility and bioremediation potential

    Directory of Open Access Journals (Sweden)

    Anton P. Avramov

    2016-12-01

    Full Text Available Microbacterium oleivorans is a predominant member of hydrocarbon-contaminated environments. We here report on the genomic analysis of M. oleivorans strain Wellendorf that was isolated from an indoor door handle. The partial genome of M. oleivorans strain Wellendorf consists of 2,916,870 bp of DNA with 2831 protein-coding genes and 49 RNA genes. The organism appears to be a versatile mesophilic heterotroph potentially capable of hydrolysis a suite of carbohydrates and amino acids. Genomic analysis revealed metabolic versatility with genes involved in the metabolism and transport of glucose, fructose, rhamnose, galactose, xylose, arabinose, alanine, aspartate, asparagine, glutamate, serine, glycine, threonine and cysteine. This is the first detailed analysis of a Microbacterium oleivorans genome.

  3. Fabrication of a planar micro Penning trap and numerical investigations of versatile ion positioning protocols

    Energy Technology Data Exchange (ETDEWEB)

    Hellwig, M; Bautista-Salvador, A; Singer, K; Schmidt-Kaler, F [Institut fuer Quanteninformationsverarbeitung, Universitaet Ulm, Albert-Einstein-Allee 11, D-89069 Ulm (Germany); Werth, G, E-mail: ferdinand.schmidt-kaler@uni-ulm.d [Physikalisches Institut, Johannes-Gutenberg-Universitaet, 55099 Mainz (Germany)

    2010-06-15

    We describe a versatile planar Penning trap structure, which allows one to dynamically modify the trapping configuration almost arbitrarily. The trap consists of 37 hexagonal electrodes, each with a circumcircle diameter of 300 {mu}m, fabricated in a gold-on-sapphire lithographic technique. Every hexagon can be addressed individually, thus shaping the electric potential. The fabrication of such a device with clean room methods is demonstrated. We illustrate the variability of the device by a detailed numerical simulation of a lateral and a vertical transport and simulate trapping in racetrack and artificial crystal configurations. The trap may be used for ions or electrons, as a versatile container for quantum optics and quantum information experiments.

  4. Exploiting the versatility of human cytochrome P450 enzymes: the promise of blue roses from biotechnology.

    Science.gov (United States)

    Gillam, E M; Guengerich, F P

    2001-12-01

    The cytochrome P450 (P450) enzymes involved in drug metabolism are among the most versatile biological catalysts known. A small number of discrete forms of human P450 are capable of catalyzing the monooxygenation of a practically unlimited variety of xenobiotic substrates, with each enzyme showing a more or less wide and overlapping substrate range. This versatility makes P450s ideally suited as starting materials for engineering designer catalysts for industrial applications. In the course of heterologous expression of P450s in bacteria, we observed the unexpected formation of blue pigments. Although this was initially assumed to be an artifact, subsequent work led to the discovery of a new function of P450s in intermediary metabolism and toxicology, new screens for protein engineering, and potential applications in the dye and horticulture industries.

  5. A Versatile and Simple Approach to Generate Light Emission in Semiconductors Mediated by Electric Double Layers

    KAUST Repository

    Pu, Jiang

    2017-04-18

    The light-emitting device is the primary device for current light sources. In principle, conventional light-emitting devices need heterostructures and/or intentional carrier doping to form a p-n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light-emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light-emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p-i-n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices.

  6. A versatile low-cost Czochralski crystal growth system for nonlinear optical organic materials

    Science.gov (United States)

    Aggarwal, M. D.; Wang, W. S.; Shields, Angela W.; Penn, Benjamin G.; Frazier, Donald O.

    1992-01-01

    A versatile low-cost Czochralski system for pulling crystals from melt has been described. It is designed for low melting, transparent, and nonlinear optical materials. One of the most important novel feature of this crystal growth system is that the entire growth process including the solid-liquid interface can be viewed from any direction. Another is the use of an after-heater to reduce excess heat loss from the surface of the melt.

  7. Peptide-protein microarrays and surface plasmon resonance detection: biosensors for versatile biomolecular interaction analysis.

    OpenAIRE

    Villiers, Marie-Bernadette; Cortes, Sandra; Brakha, Carine; Lavergne, Jean-Pierre; Marquette, Christophe; Deny, Paul; Livache, Thierry; Marche, Patrice

    2010-01-01

    International audience; Biosensors in microarray format provide promising tools for high-throughput analyses of complex samples. Although they are able to detect, quantify and characterize a multitude of compounds, most of the available devices are specialized in the analysis of one type of interaction, limiting their application to a define area. The aim of our work was to develop and characterize versatile protein (or peptide) microarrays suitable for the simultaneous analysis of a large pa...

  8. Molecular Lock: A Versatile Key to Enhance Efficiency and Stability of Organic Solar Cells.

    Science.gov (United States)

    Cheng, Pei; Yan, Cenqi; Lau, Tsz-Ki; Mai, Jiangquan; Lu, Xinhui; Zhan, Xiaowei

    2016-07-01

    4,4'-Biphenol (BPO), a common, cheap chemical, is employed as a "molecular lock" in blends of fluorine-containing polymer or small molecule donors and fullerene acceptors to lock donors via hydrogen bond formed between the donor and BPO. The molecular lock is a versatile key to enhance the efficiency and stability of organic solar cells simultaneously. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. LightNet: A Versatile, Standalone Matlab-based Environment for Deep Learning

    OpenAIRE

    Ye, Chengxi; Zhao, Chen; Yang, Yezhou; Fermuller, Cornelia; Aloimonos, Yiannis

    2016-01-01

    LightNet is a lightweight, versatile and purely Matlab-based deep learning framework. The idea underlying its design is to provide an easy-to-understand, easy-to-use and efficient computational platform for deep learning research. The implemented framework supports major deep learning architectures such as Multilayer Perceptron Networks (MLP), Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN). The framework also supports both CPU and GPU computation, and the switch betwe...

  10. The ANL X6B beamline at NSLS: A versatile facility

    Energy Technology Data Exchange (ETDEWEB)

    Huang, K.G.; Ramanathan, M. [Argonne National Lab., IL (United States); Montano, P.A. [Argonne National Lab., IL (United States)]|[Illinois Univ., Chicago, IL (United States). Dept. of Physics

    1994-07-01

    We have described the x-ray optics and beamline performance of the ANL X6B beam line at the NSLS. Considerable flexibility has been built into the beam line to accommodate a wide range of x-ray diffraction, scattering, and spectroscopy experiments with various requirements. We presented selected examples of experimental results and showed that with the high intensity, high energy resolution, high-q resolution, and energy tunability, the X6B beam line has become a versatile facility.

  11. Base-pairing versatility determines wobble sites in tRNA anticodons of vertebrate mitogenomes.

    Directory of Open Access Journals (Sweden)

    Miguel M Fonseca

    Full Text Available BACKGROUND: Vertebrate mitochondrial genomes typically have one transfer RNA (tRNA for each synonymous codon family. This limited anticodon repertoire implies that each tRNA anticodon needs to wobble (establish a non-Watson-Crick base pairing between two nucleotides in RNA molecules to recognize one or more synonymous codons. Different hypotheses have been proposed to explain the factors that determine the nucleotide composition of wobble sites in vertebrate mitochondrial tRNA anticodons. Until now, the two major postulates--the "codon-anticodon adaptation hypothesis" and the "wobble versatility hypothesis"--have not been formally tested in vertebrate mitochondria because both make the same predictions regarding the composition of anticodon wobble sites. The same is true for the more recent "wobble cost hypothesis". PRINCIPAL FINDINGS: In this study we have analyzed the occurrence of synonymous codons and tRNA anticodon wobble sites in 1553 complete vertebrate mitochondrial genomes, focusing on three fish species with mtDNA codon usage bias reversal (L-strand is GT-rich. These mitogenomes constitute an excellent opportunity to study the evolution of the wobble nucleotide composition of tRNA anticodons because due to the reversal the predictions for the anticodon wobble sites differ between the existing hypotheses. We observed that none of the wobble sites of tRNA anticodons in these unusual mitochondrial genomes coevolved to match the new overall codon usage bias, suggesting that nucleotides at the wobble sites of tRNA anticodons in vertebrate mitochondrial genomes are determined by wobble versatility. CONCLUSIONS/SIGNIFICANCE: Our results suggest that, at wobble sites of tRNA anticodons in vertebrate mitogenomes, selection favors the most versatile nucleotide in terms of wobble base-pairing stability and that wobble site composition is not influenced by codon usage. These results are in agreement with the "wobble versatility hypothesis".

  12. Versatile Protecting-Group Free Tetrazolomethane Amine Synthesis by Ugi Reaction.

    Science.gov (United States)

    Patil, Pravin; de Haan, Michel; Kurpiewska, Katarzyna; Kalinowska-Tłuścik, Justyna; Dömling, Alexander

    2016-03-14

    The use of ammonia in the Ugi reaction is often problematic due to low yields and multiple side reactions. Here, we report the use of ammonia in the tetrazole Ugi variation providing a clean, good-to-high yielding reaction, especially with ketones as oxo components. The scope and limitations of this reaction and a structure-reactivity relationship are provided by performing >85 reactions. The primary amine component of the α-amino tetrazole is a versatile starting material for further reactions.

  13. New perspective for phage display as an efficient and versatile technology of functional proteomics.

    Science.gov (United States)

    Li, Wei; Caberoy, Nora B

    2010-01-01

    Phage display with antibody libraries has been widely used with versatile applications. However, phage display with cDNA libraries is rare and inefficient. Because of uncontrollable reading frames and stop codons in cDNA repertoires, high percentage of phage clones identified from conventional cDNA libraries are non-open reading frames (non-ORFs) encoding unnatural short peptides with minimal implications in protein networks. Consequently, phage display has not been used as a technology of functional proteomics to elucidate protein-protein interactions like yeast two-hybrid system and mass spectrometry-based technologies. Several strategies, including C-terminal display and ORF cDNA libraries, have been explored to circumvent the technical problem. The accumulative endeavors eventually led to the efficient elucidation of a large number of tubby- and phosphatidylserine-binding proteins in recent studies by ORF phage display with minimal reading frame issue. ORF phage display inherits all the versatile applications of antibody phage display, but enables efficient identification of real endogenous proteins with efficiency, sensitivity, and accuracy comparable to other technologies of functional proteomics. Its ELISA-like procedure can be conveniently adapted by individual laboratories or fully automated for high-throughput screening. Thus, ORF phage display is an efficient, sensitive, versatile, and convenient technology of functional proteomics for elucidation of global and pathway-specific protein-protein interactions, disease mechanisms, or therapeutic targets.

  14. Bacterial Communities: Interactions to Scale

    Science.gov (United States)

    Stubbendieck, Reed M.; Vargas-Bautista, Carol; Straight, Paul D.

    2016-01-01

    In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities. PMID:27551280

  15. Acute bacterial prostatitis with osteomyelitis

    Science.gov (United States)

    Nargund, V H; Stewart, P A Hamilton

    1995-01-01

    This short case presentation concerns the simultaneous occurrence of acute bacterial prostatitis and osteomyelitis due to staphylococcal bacteraemia hitherto unrecorded in the literature. ImagesFigure 1Figure 2 PMID:7629772

  16. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  17. Arsenic uptake in bacterial calcite

    Science.gov (United States)

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03 Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  18. Arsenic uptake in bacterial calcite

    Energy Technology Data Exchange (ETDEWEB)

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew G.; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and Xray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  19. Versatile Padding

    Science.gov (United States)

    1976-01-01

    Dynamic Systems, Inc. started after NASA-Ames scientists began work on a padding concept in 1968. They were looking for a better airplane seat. They found a new foam material that today has all kinds of additional applications including wheelchairs, x-ray table pads, off road vehicle seats, ski boots, and football helmet liners. Temper foam exhibits about 340% less shock from impact. Material is an open-cell polyurethane silicone plastic foam that takes shape of impressed objects but returns to its original shape even after 90% compression.

  20. Versatile Hydrogen

    Indian Academy of Sciences (India)

    Hydrogen is probably the most intriguing ele- ment in the periodic table. Although it is only the seventh most abundant element on earth, it is the most abundant element in the uni- verse. It combines with almost all the ele- ments of the periodic table, except for a few transition elements, to form binary compounds of the type E.

  1. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV. PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition.

  2. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria.

    Science.gov (United States)

    Ashida, Hiroshi; Sasakawa, Chihiro

    2015-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections.

  3. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  4. Versatile Antagonistic Activities of Soil-Borne Bacillus spp. and Pseudomonas spp. against Phytophthora infestans and Other Potato Pathogens

    Directory of Open Access Journals (Sweden)

    Simon Caulier

    2018-02-01

    Full Text Available The world potato is facing major economic losses due to disease pressure and environmental concerns regarding pesticides use. This work aims at addressing these two issues by isolating indigenous bacteria that can be integrated into pest management strategies. More than 2,800 strains of Bacillus-like and Pseudomonas-like were isolated from several soils and substrates associated with potato agro-systems in Belgium. Screenings for antagonistic activities against the potato pathogens Alternaria solani, Fusarium solani (BCCM-MUCL 5492, Pectobacterium carotovorum (ATCC 15713, Phytophthora infestans (CRA-W10022 and Rhizoctonia solani (BCCM-MUCL 51929 were performed, allowing the selection of 52 Bacillus spp. and eight Pseudomonas spp. displaying growth inhibition of at least 50% under in vitro conditions, particularly against P. infestans. All 60 bacterial isolates were identified based on 16S rRNA gene sequencing and further characterized for the production of potential bio-active secondary metabolites. The antagonistic activities displayed by the selected strains indicated that versatile metabolites can be produced by the strains. For instance, the detection of genes involved bacilysin biosynthesis was correlated with the strong antagonism of Bacillus pumilus strains toward P. infestans, whereas the production of both bio-surfactants and siderophores might explain the high antagonistic activities against late blight. Greenhouse assays with potato plants were performed with the most effective strains (seven Bacillus spp. and four Pseudomonas spp. in order to evaluate their in vivo antagonistic effect against P. infestans. Based on these results, four strains (Bacillus amyloliquefaciens 17A-B3, Bacillus subtilis 30B-B6, Pseudomonas brenneri 43R-P1 and Pseudomonas protegens 44R-P8 were retained for further evaluation of their protection index against P. infestans in a pilot field trial. Interestingly, B. subtilis 30B-B6 was shown to significantly

  5. A nanobody:GFP bacterial platform that enables functional enzyme display and easy quantification of display capacity

    DEFF Research Database (Denmark)

    Wendel, Sofie; Christian Fischer, Emil; Martinez, Virginia

    2016-01-01

    Background: Bacterial surface display is an attractive technique for the production of cell-anchored, functional proteins and engineering of whole-cell catalysts. Although various outer membrane proteins have been used for surface display, an easy and versatile high-throughput-compatible assay...... to displaying the nanobody alone. We used flow cytometry to analyse display capability on single-cell versus population level and found that the signal peptide of the anchor has great effect on display efficiency.Conclusions: We have developed an inexpensive and easy read-out assay for surface display using...

  6. Immunogenicity and protective efficacy induced by self-amplifying mRNA vaccines encoding bacterial antigens.

    Science.gov (United States)

    Maruggi, Giulietta; Chiarot, Emiliano; Giovani, Cinzia; Buccato, Scilla; Bonacci, Stefano; Frigimelica, Elisabetta; Margarit, Immaculada; Geall, Andrew; Bensi, Giuliano; Maione, Domenico

    2017-01-05

    Nucleic acid vaccines represent an attractive approach to vaccination, combining the positive attributes of both viral vectors and live-attenuated vaccines, without the inherent limitations of each technology. We have developed a novel technology, the Self-Amplifying mRNA (SAM) platform, which is based on the synthesis of self-amplifying mRNA formulated and delivered as a vaccine. SAM vaccines have been shown to stimulate robust innate and adaptive immune responses in small animals and non-human primates against a variety of viral antigens, thus representing a safe and versatile tool against viral infections. To assess whether the SAM technology could be used for a broader range of targets, we investigated the immunogenicity and efficacy of SAM vaccines expressing antigens from Group A (GAS) and Group B (GBS) Streptococci, as models of bacterial pathogens. Two prototype bacterial antigens (the double-mutated GAS Streptolysin-O (SLOdm) and the GBS pilus 2a backbone protein (BP-2a)) were successfully expressed by SAM vectors. Mice immunized with both vaccines produced significant amounts of fully functional serum antibodies. The antibody responses generated by SAM vaccines were capable of conferring consistent protection in murine models of GAS and GBS infections. Inclusion of a eukaryotic secretion signal or boosting with the recombinant protein resulted in higher specific-antibody levels and protection. Our results support the concept of using SAM vaccines as potential solution for a wide range of both viral and bacterial pathogens, due to the versatility of the manufacturing processes and the broad spectrum of elicited protective immune response. Copyright © 2016 GSK Vaccines. Published by Elsevier Ltd.. All rights reserved.

  7. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  8. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    enzymes that are unique in exploiting the ATP/GTP-binding Walker motif to catalyze phosphorylation of protein tyrosine residues. Characterized for the first time only a decade ago, BY-kinases have now come to the fore. Important regulatory roles have been linked with these enzymes, via their involvement......Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by tyrosine...

  9. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...

  10. Acute bacterial and viral meningitis.

    Science.gov (United States)

    Bartt, Russell

    2012-12-01

    Most cases of acute meningitis are infectious and result from a potentially wide range of bacterial and viral pathogens. The organized approach to the patient with suspected meningitis enables the prompt administration of antibiotics, possibly corticosteroids, and diagnostic testing with neuroimaging and spinal fluid analysis. Acute meningitis is infectious in most cases and caused by a potentially wide range of bacterial and viral pathogens. Shifts in the epidemiology of bacterial pathogens have been influenced by changes in vaccines and their implementation. Seasonal and environmental changes influence the likely viral and rickettsial pathogens. The organized approach to the patient with suspected meningitis enables the prompt administration of antibiotics, possibly corticosteroids, and diagnostic testing with neuroimaging and spinal fluid analysis. Pertinent testing and treatment can vary with the clinical presentation, season, and possible exposures. This article reviews the epidemiology, clinical presentation, diagnosis, and treatment of acute meningitis.

  11. A versatile gas interface for routine radiocarbon analysis with a gas ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, L., E-mail: wacker@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Fahrni, S.M. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Hajdas, I. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Molnar, M. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Synal, H.-A. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Szidat, S. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Zhang, Y.L. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland)

    2013-01-15

    In 2010 more than 600 radiocarbon samples were measured with the gas ion source at the MIni CArbon DAting System (MICADAS) at ETH Zurich and the number of measurements is rising quickly. While most samples contain less than 50 {mu}g C at present, the gas ion source is attractive as well for larger samples because the time-consuming graphitization is omitted. Additionally, modern samples are now measured down to 5 per-mill counting statistics in less than 30 min with the recently improved gas ion source. In the versatile gas handling system, a stepping-motor-driven syringe presses a mixture of helium and sample CO{sub 2} into the gas ion source, allowing continuous and stable measurements of different kinds of samples. CO{sub 2} can be provided in four different ways to the versatile gas interface. As a primary method, CO{sub 2} is delivered in glass or quartz ampoules. In this case, the CO{sub 2} is released in an automated ampoule cracker with 8 positions for individual samples. Secondly, OX-1 and blank gas in helium can be provided to the syringe by directly connecting gas bottles to the gas interface at the stage of the cracker. Thirdly, solid samples can be combusted in an elemental analyzer or in a thermo-optical OC/EC aerosol analyzer where the produced CO{sub 2} is transferred to the syringe via a zeolite trap for gas concentration. As a fourth method, CO{sub 2} is released from carbonates with phosphoric acid in septum-sealed vials and loaded onto the same trap used for the elemental analyzer. All four methods allow complete automation of the measurement, even though minor user input is presently still required. Details on the setup, versatility and applications of the gas handling system are given.

  12. Availability, diversification and versatility explain human selection of introduced plants in Ecuadorian traditional medicine

    Science.gov (United States)

    Gaoue, Orou G.; de la Torre, Lucía; Navarrete, Hugo; Muriel, Priscilla; Macía, Manuel J.; Balslev, Henrik; León-Yánez, Susana; Jørgensen, Peter; Duffy, David Cameron

    2017-01-01

    Globally, a majority of people use plants as a primary source of healthcare and introduced plants are increasingly discussed as medicine. Protecting this resource for human health depends upon understanding which plants are used and how use patterns will change over time. The increasing use of introduced plants in local pharmacopoeia has been explained by their greater abundance or accessibility (availability hypothesis), their ability to cure medical conditions that are not treated by native plants (diversification hypothesis), or as a result of the introduced plants’ having many different simultaneous roles (versatility hypothesis). In order to describe the role of introduced plants in Ecuador, and to test these three hypotheses, we asked if introduced plants are over-represented in the Ecuadorian pharmacopoeia, and if their use as medicine is best explained by the introduced plants’ greater availability, different therapeutic applications, or greater number of use categories. Drawing on 44,585 plant-use entries, and the checklist of >17,000 species found in Ecuador, we used multi-model inference to test if more introduced plants are used as medicines in Ecuador than expected by chance, and examine the support for each of the three hypotheses above. We find nuanced support for all hypotheses. More introduced plants are utilized than would be expected by chance, which can be explained by geographic distribution, their strong association with cultivation, diversification (except with regard to introduced diseases), and therapeutic versatility, but not versatility of use categories. Introduced plants make a disproportionately high contribution to plant medicine in Ecuador. The strong association of cultivation with introduced medicinal plant use highlights the importance of the maintenance of human-mediated environments such as homegardens and agroforests for the provisioning of healthcare services. PMID:28886104

  13. Few-layer graphene shells and nonmagnetic encapsulates: a versatile and nontoxic carbon nanomaterial.

    Science.gov (United States)

    Bachmatiuk, Alicja; Mendes, Rafael G; Hirsch, Cordula; Jähne, Carsten; Lohe, Martin R; Grothe, Julia; Kaskel, Stefan; Fu, Lei; Klingeler, Rüdiger; Eckert, Jürgen; Wick, Peter; Rümmeli, Mark H

    2013-12-23

    In this work a simple and scalable approach to coat nonmagnetic nanoparticles with few-layer graphene is presented. In addition, the easy processing of such nanoparticles to remove their core, leaving only the 3D graphene nanoshell, is demonstrated. The samples are comprehensively characterized, as are their versatility in terms of functionalization and as a material for electrochemical storage. Indeed, these 3D graphene nanostructures are easily functionalized much as is found with carbon nanotubes and planar graphene. Electrochemical investigations indicate these nanostructures are promising for stable long-life battery applications. Finally, initial toxicological investigations suggest no acute health risk from these 3D graphene nanostructures.

  14. Coordination chemistry and applications of versatile 4,5-diazafluorene derivatives.

    Science.gov (United States)

    Annibale, Vincent T; Song, Datong

    2016-01-07

    This perspective review will examine the coordination chemistry and applications of metal complexes of 4,5-diazafluorene derivatives. The versatile derivatives of 4,5-diazafluorene can serve multiple roles, and display a number of coordination modes. The ambidentate derivatives with multiple coordination sites can allow for the syntheses of coordination polymers, multimetallic, and macrocyclic complexes. In addition, certain 4,5-diazafluorene derivatives can serve as spectator ligands to support reactivity at the metal centre, or as reactive actor ligands engaging in atypical reactivity patterns. The applications of metal complexes of 4,5-diazafluorene derivatives in catalysis, photochemistry and photophysics, as well as in bioinorganic chemistry are also surveyed.

  15. A versatile multi-user polyimide surface micromachinning process for MEMS applications

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2015-04-01

    This paper reports a versatile multi-user micro-fabrication process for MEMS devices, the \\'Polyimide MEMS Multi-User Process\\' (PiMMPs). The reported process uses polyimide as the structural material and three separate metallization layers that can be interconnected depending on the desired application. This process enables for the first time the development of out-of-plane compliant mechanisms that can be designed using six different physical principles for actuation and sensing on a wafer from a single fabrication run. These principles are electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception. © 2015 IEEE.

  16. Versatile, low-cost, computer-controlled, sample positioning system for vacuum applications

    Science.gov (United States)

    Vargas-Aburto, Carlos; Liff, Dale R.

    1991-01-01

    A versatile, low-cost, easy to implement, microprocessor-based motorized positioning system (MPS) suitable for accurate sample manipulation in a Second Ion Mass Spectrometry (SIMS) system, and for other ultra-high vacuum (UHV) applications was designed and built at NASA LeRC. The system can be operated manually or under computer control. In the latter case, local, as well as remote operation is possible via the IEEE-488 bus. The position of the sample can be controlled in three linear orthogonal and one angular coordinates.

  17. A versatile Lock-In digital Amplifier (LIdA): the case of mechanical resonances

    Science.gov (United States)

    Bessas, D.; Brück, E.

    2017-05-01

    The assembly of a Lock-In digital Amplifier (LIdA) from widely accessible ready-made modules is presented. This equipment, which does not require any advanced knowledge of electronics or programming, may introduce the experimenter to resonant techniques by registering mechanical resonances. The freely available control program allows for general data acquisition and further data processing. The apparatus is versatile and may corroborate the science and engineering laboratory in elasticity measurements or in a series of experiments where a modulated signal is a prerequisite.

  18. SEVA Linkers: A Versatile and Automatable DNA Backbone Exchange Standard for Synthetic Biology

    DEFF Research Database (Denmark)

    Kim, Se Hyeuk; Cavaleiro, Mafalda; Rennig, Maja

    2016-01-01

    DNA vectors serve to maintain and select recombinant DNA in cell factories, and as design complexity increases, there is a greater need for well-characterized parts and methods for their assembly. Standards in synthetic biology are top priority, but standardizing molecular cloning contrasts...... flexibility, and different researchers prefer and master different molecular technologies. Here, we describe a new, highly versatile and automatable standard “SEVA linkers” for vector exchange. SEVA linkers enable backbone swapping with 20 combinations of classical enzymatic restriction/ligation, Gibson...... to the synthetic biology community....

  19. Rapid and Versatile Photonic Annealing of Graphene Inks for Flexible Printed Electronics.

    Science.gov (United States)

    Secor, Ethan B; Ahn, Bok Y; Gao, Theodore Z; Lewis, Jennifer A; Hersam, Mark C

    2015-11-01

    Intense pulsed light (IPL) annealing of graphene inks is demonstrated for rapid post-processing of inkjet-printed patterns on various substrates. A conductivity of ≈25,000 S m(-1) is achieved following a single printing pass using a concentrated ink containing 20 mg mL(-1) graphene, establishing this strategy as a practical and effective approach for the versatile and high-performance integration of graphene in printed and flexible electronics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A versatile setup using femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yujie, E-mail: styojm@physics.tamu.edu [Texas A& M University, College Station, Texas 77843 (United States); Voronine, Dmitri V.; Sokolov, Alexei V. [Texas A& M University, College Station, Texas 77843 (United States); Baylor University, Waco, Texas 76798 (United States); Scully, Marlan O. [Texas A& M University, College Station, Texas 77843 (United States); Baylor University, Waco, Texas 76798 (United States); Princeton University, Princeton, New Jersey 08544 (United States)

    2015-08-15

    We report a versatile setup based on the femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering. The setup uses a femtosecond Ti:Sapphire oscillator source and a folded 4f pulse shaper, in which the pulse shaping is carried out through conventional optical elements and does not require a spatial light modulator. Our setup is simple in alignment, and can be easily switched between the collinear single-beam and the noncollinear two-beam configurations. We demonstrate the capability for investigating both transparent and highly scattering samples by detecting transmitted and reflected signals, respectively.

  1. Eucalypt kraft pulp delignification with polyoxometalate assisted by fungal versatile peroxidase

    OpenAIRE

    Marques, Gisela; Gamelas, José A. F.; Ruiz-Dueñas, F. J.; Río Andrade, José Carlos del; Evtuguin, Dmitry; Martínez, Ángel T.; Gutiérrez Suárez, Ana

    2010-01-01

    Polyoxometalates have been reported as alternative redox catalysts for pulp delignification in environmentally-friendly bleaching sequences. Enzymatic catalysis is a promising approach to regenerate polyoxometalates that are highly effective in delignification, but very difficult to be subsequently reoxidized by O2 and other oxidants. In this work, the oxidation of a manganese-substituted polyoxometalate (POM) [SiW11MnII(H2O)O39]6- (SiW11MnII) by Mn-oxidizing versatile peroxidase (VP) to give...

  2. Nanosphere of Semicrystalline Polyaniline Powder: An Effective, Versatile, and Reusable Catalyst for Hantzsch Reaction

    Directory of Open Access Journals (Sweden)

    Ravi Bolagam

    2014-01-01

    Full Text Available Polyaniline salt containing 1-hydroxyethane-1,1-diphosphonic acid with nanosphere morphology in semicrystalline powder form was successfully synthesized by interfacial polymerization pathway and demonstrated as polymer based acid catalyzed in the synthesis of 1,4-dihydropyridines and polyhydroquinoline derivatives. This catalyst promotes the reaction under solvent free condition in excellent yield in 10 min with recyclability. The advantages of this methodology are the easy synthesis of polymer containing acid group catalyst in powder form having easily handlable, efficient, versatile, and reusable nature.

  3. Curved microchannels and bacterial streamers

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2010-03-01

    Bacterial biofilms are commonly identified as microbial communities attached to a surface and encased in a self-secreted extracellular matrix. Due to their increased resistance to antimicrobial agents, biofilms have an enormous impact on health and medicine (e.g., wound healing, implant-associated infections, disease transmission). On the other hand, they constitute a major component of the stream ecosystem by increasing transport of nutrients and retention of suspended particles. In this talk, we present an experimental study of bacterial biofilm development in a microfluidic device. In particular, we show the formation of filamentous structures, or streamers, in curved channels and how these suspended biofilms are linked to the underlying hydrodynamics.

  4. Bacterial computing with engineered populations.

    Science.gov (United States)

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...... technological advances in microfluidics and reporter genes have improved this scenario. Here, we summarize recent progress in the field, revealing the ubiquitous bacterial stress alarmone ppGpp as an emerging central regulator of multidrug tolerance and persistence, both in stochastically and environmentally...... induced persistence. In several different organisms, toxin-antitoxin modules function as effectors of ppGpp-induced persistence....

  6. Bacterial Biofilm Control by Perturbation of Bacterial Signaling Processes

    DEFF Research Database (Denmark)

    Jakobsen, Tim Holm; Tolker-Nielsen, Tim; Givskov, Michael

    2017-01-01

    infections. A potential method for biofilm dismantling is chemical interception of regulatory processes that are specifically involved in the biofilm mode of life. In particular, bacterial cell to cell signaling called “Quorum Sensing” together with intracellular signaling by bis-(3′-5′)-cyclic...

  7. Two-dimensional flow-through microcosms - Versatile test systems to study biodegradation processes in porous aquifers

    Science.gov (United States)

    Bauer, Robert D.; Rolle, Massimo; Kürzinger, Petra; Grathwohl, Peter; Meckenstock, Rainer U.; Griebler, Christian

    2009-05-01

    SummaryA fundamental prerequisite of any remedial activity is a sound knowledge of both the biotic and abiotic processes involved in transport and degradation of contaminants. Investigations of these aspects in situ often seem infeasible due to the complexity of interacting processes. A simplified portrayal of nature can be facilitated in laboratory-based two-dimensional (2D) sediment flow-through microcosms. This paper describes the versatility of such simple aquifer model systems with respect to biodegradation of aromatic hydrocarbons, i.e. toluene and ethylbenzene, under various environmental conditions. Initially constructed to study non-reactive and bioreactive transport of organic contaminants in homogeneous porous media under steady state hydraulic conditions, experimental setups developed towards more realistic heterogeneous sediment packing and transient hydraulic conditions. High-resolution spatial and temporal sampling allowed to obtain new insights on the distribution of bioactivities in contaminant plumes and associated controlling and limiting factors. Major biodegradation activities in saturated porous sediments are located at the fringes of contaminant plumes and are driven by dispersive mixing. These hot-spots of contaminant biotransformation are characterized by steep physical-chemical gradients in the millimeter to centimeter range. Sediment heterogeneity, i.e. high-conductivity zones, was shown to significantly enhance transverse mixing and subsequently biodegradation. On the contrary, transient hydraulic conditions may generate intermediate disturbances to biodegrader populations and thus may interfere with optimized contaminant conversion. However, a bacterial strain aerobically degrading toluene, i.e. Pseudomonas putida F1, was shown to adapt to vertically moving contaminant plumes, in the way that it regained full biodegradation potential two-times faster in areas with a mid-term (days to weeks) contamination history than in areas not

  8. Bacterial cellulose skin masks-Properties and sensory tests.

    Science.gov (United States)

    Pacheco, Guilherme; de Mello, Carolina Véspoli; Chiari-Andréo, Bruna Galdorfini; Isaac, Vera Lucia Borges; Ribeiro, Sidney José Lima; Pecoraro, Édison; Trovatti, Eliane

    2017-09-29

    Bacterial cellulose (BC) is a versatile material produced by microorganisms in the form of a membranous hydrogel, totally biocompatible, and endowed with high mechanical strength. Its high water-holding capacity based on its highly porous nanofibrillar structure allows BC to incorporate and to release substances very fast, thus being suitable for the preparation of skincare masks. The preparation and characterization of cosmetic masks based on BC membranes and active cosmetics. The masks were prepared by the simple incorporation of the cosmetic actives into BC membranes, used as a swelling matrix. The masks were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), sensory tests, and skin moisture tests on volunteers. The results of sensory tests revealed the good performance of BC, being considered effective by the panel of volunteers, specially for adhesion to the skin (7.7 at the score scale), and improvement of the skin moisture (the hydration effect increased 76% in 75% of the volunteers that used vegetable extract mask formulation [VEM]), or a decrease in skin hydration (80% of the volunteers showed 32.6% decrease on skin hydration using propolis extract formulation [PEM] treatment), indicating the BC nanofiber membranes can be used to skincare applications. The results demonstrate the BC can be used as an alternative support for cosmetic actives for skin treatment. © 2017 Wiley Periodicals, Inc.

  9. Bacterial consortium proteomics under 4-chlorosalicylate carbon-limiting conditions.

    Science.gov (United States)

    Bobadilla Fazzini, Roberto A; Bielecka, Agata; Quintas, Ana K Poucas; Golyshin, Peter N; Preto, Maria J; Timmis, Kenneth N; dos Santos, Vitor A P Martins

    2009-04-01

    In this study, the stable consortium composed by Pseudomonas reinekei strain MT1 and Achromobacter xylosoxidans strain MT3 (cell numbers in proportion 9:1) was under investigation to reveal bacterial interactions that take place under severe nutrient-limiting conditions. The analysis of steady states in continuous cultures was carried out at the proteome, metabolic profile, and population dynamic levels. Carbon-limiting studies showed a higher metabolic versatility in the community through upregulation of parallel catabolic enzymes (salicylate 5-hydroxylase and 17-fold on 2-keto-4-pentenoate hydratase) indicating a possible alternative carbon routing in the upper degradation pathway highlighting the effect of minor proportions of strain MT3 over the major consortia component strain MT1 with a significant change in the expression levels of the enzymes of the mainly induced biodegradation pathway such as salicylate 1-hydroxylase and catechol 1,2-dioxygenase together with important changes in the outer membrane composition of P. reinekei MT1 under different culture conditions. The study has demonstrated the importance of the outer membrane as a sensing/response protective barrier caused by interspecies interactions highlighting the role of the major outer membrane proteins OprF and porin D in P. reinekei sp. MT1 under the culture conditions tested.

  10. Bacterial kidney disease (Renibacterium salmoninarum)

    Science.gov (United States)

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a prevalent disease of salmonid fish that impacts sustainable production for consumption and species conservation efforts. The disease is chronic in nature and mortality most often occurs in juvenile salmonids and prespawning a...

  11. Biotechnological applications of bacterial cellulases

    Czech Academy of Sciences Publication Activity Database

    Menéndez, E.; García-Fraile, Paula; Rivas, R.

    2015-01-01

    Roč. 2, č. 3 (2015), s. 163-182 ISSN 2306-5354 R&D Projects: GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : Biotechnological applications * Bacterial cellulases * Cellulose degradation Subject RIV: EE - Microbiology, Virology

  12. Bacterial Stationary-Phase Evolution

    Directory of Open Access Journals (Sweden)

    Ana Butorac

    2011-01-01

    Full Text Available Metagenomics and advances in molecular biology methods have enhanced knowledge of microbial evolution, metabolism, functions, their interactions with other organisms and their environment. The ability to persist and adapt to changes in their environment is a common lifestyle of 1 % of the known culturable bacteria. Studies in the variety of species have identified an incredible diversity of bacterial lifespan. The holy grail of molecular biology is to understand the integrated genetic and metabolic patterns of prokaryotic organisms like the enteric bacterium Escherichia coli. The usual description of E. coli life cycle comprises four phases: lag, logarithmic, stationary, and death phase, omitting their persistence and evolution during prolonged stationary phase. During prolonged stationary/starvation period, in batch bacterial culture, selected mutants with increased fitness express growth advantage in stationary phase (GASP, which enables them to grow and displace the parent cells as the majority population. The analyses of growth competition of Gram-negative and/or Gram-positive mixed bacterial cultures showed that GASP phenomenon can result in four GASP phenotypes: strong, moderate, weak or abortive. Bacterial stress responses to starvation include functions that can increase genetic variability and produce transient mutator state, which is important for adaptive evolution.

  13. Community-acquired bacterial meningitis

    NARCIS (Netherlands)

    van de Beek, Diederik; Brouwer, Matthijs; Hasbun, Rodrigo; Koedel, Uwe; Whitney, Cynthia G.; Wijdicks, Eelco

    2016-01-01

    Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma

  14. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  15. Bacterial infec tions in travellers

    African Journals Online (AJOL)

    caused by bacterial infections, the most common pathogens being enterotoxigenic Escherichia coli, Campylobacter jejuni, Shigella and Salmonella species. TD occurs equally in men and women, generally occurs in younger travellers and is more likely in certain destinations: Asia, Africa, Mexico, south and central America.

  16. Beyond flexible batteries: aesthetically versatile, printed rechargeable power sources for smart electronics

    Science.gov (United States)

    Lee, Sang-Young

    2017-05-01

    Forthcoming wearable/flexible electronics with compelling shape diversity and mobile usability have garnered significant attention as a kind of disruptive technology to drastically change our daily lives. From a power source point of view, conventional rechargeable batteries (represented by lithium-ion batteries) with fixed shapes and dimensions are generally fabricated by winding (or stacking) cell components (such as anodes, cathodes and separator membranes) and then packaging them with (cylindrical-/rectangular-shaped) metallic canisters or pouch films, finally followed by injection of liquid electrolytes. In particular, the use of liquid electrolytes gives rise to serious concerns in cell assembly, because they require strict packaging materials to avoid leakage problems and also separator membranes to prevent electrical contact between electrodes. For these reasons, the conventional cell assembly and materials have pushed the batteries to lack of variety in form factors, thus imposing formidable challenges on their integration into versatile-shaped electronic devices. Here, as a facile and efficient strategy to address the aforementioned longstanding challenge, we demonstrate a new class of printed solid-state Li-ion batteries and also all-inkjet-printed solid-state supercapacitors with exceptional shape conformability and aesthetic versatility which lie far beyond those achievable with conventional battery technologies.

  17. Insights into the unique functionality of inorganic micro/nanoparticles for versatile ultrasound theranostics.

    Science.gov (United States)

    Qian, Xiaoqin; Han, Xiaoxia; Chen, Yu

    2017-10-01

    The clinical ultrasound (US)-based theranostic biomedicine suffers from the critical issue that traditional microbubbles (MBs) have lots of drawbacks such as low stability, large particle size, difficult structural control, etc. The unique composition, structure and functionality of inorganic micro/nanoplatforms have shown their great prospect for solving these critical issues and drawbacks of traditional organic MBs. This review summarizes and discusses the state-of-art development on exploring inorganic micro/nanoparticles for versatile US-based biomedical applications, ranging from US imaging, photoacoustic imaging, sonodynamic therapy, high intensity-focused US ablation and US-triggered chemotherapy. These inorganic micro/nanoplatforms include silica-based particles, Au, carbon nanotubes, TiO2, manganese oxide, iron oxide, Prussian blue, inorganic gas-generating nanoparticles and their versatile composite micro/nanosystems. Especially, their unique structure/composition-functionality relationships and biocompatibility/biosafety in US-based theranostics have been discussed and revealed in detail. Their facing challenges and future developments are finally discussed to promote their further clinical translations. It is highly expected that these inorganic micro/nanoplatforms will enter the clinical stage to benefit the personalized theranostics biomedicine based on their unique functionalities and high performance as necessarily required in US-based theranostics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Versatile method for template-free synthesis of single crystalline metal and metal alloy nanowires.

    Science.gov (United States)

    Scott, John A; Totonjian, Daniel; Martin, Aiden A; Tran, Toan Trong; Fang, Jinghua; Toth, Milos; McDonagh, Andrew M; Aharonovich, Igor; Lobo, Charlene J

    2016-02-07

    Metal and metal alloy nanowires have applications ranging from spintronics to drug delivery, but high quality, high density single crystalline materials have been surprisingly difficult to fabricate. Here we report a versatile, template-free, self-assembly method for fabrication of single crystalline metal and metal alloy nanowires (Co, Ni, NiCo, CoFe, and NiFe) by reduction of metal nitride precursors formed in situ by reaction of metal salts with a nitrogen source. Thiol reduction of the metal nitrides to the metallic phase at 550-600 °C results in nanowire growth. In this process, sulfur acts as a uniaxial structure-directing agent, passivating the surface of the growing nanowires and preventing radial growth. The versatility of the method is demonstrated by achieving nanowire growth from gas-phase, solution-phase or a combination of gas- and solution-phase precursors. The fabrication method is suited to large-area CVD on a wide range of solid substrates.

  19. Solid-Phase Bioconjugation of Heterobifunctional Adaptors for Versatile Assembly of Bispecific Targeting Ligands

    Science.gov (United States)

    2015-01-01

    High-throughput generation of bispecific molecules promises to expedite the discovery of new molecular therapeutics and guide engineering of novel multifunctional constructs. However, high synthesis complexity and cost have hampered the discovery of bispecific molecules in drug development and biomedical research. Herein we describe a simple solid-phase bioconjugation procedure for preparation of Protein A(G,L)-PEG-Streptavidin heterobifunctional adaptors (with 1:1:1 stoichiometry), which enable self-assembly of unmodified antibodies and biotinylated molecules into bispecific targeting ligands in a versatile mix-and-use manner. Utility of such adaptors is demonstrated by assembly of anti-CD3 and anti-Her2 antibodies into bispecific CD3xHer2 targeting ligands, which efficiently drive T-cell-mediated lysis of Her2-positive cancer cells. In comparison to bioconjugation in solution, the solid-phase procedure described here offers precise stoichiometry control, ease of purification, and high yield of functional conjugates. Simplicity and versatility should prove this methodology instrumental for preparation of bispecific ligands, as well as for high-throughput screening of bispecific combinations, before proceeding to synthesis of lead candidates via recombinant engineering or chemical cross-linking. PMID:25010411

  20. Novel versatile smart phone based Microplate readers for on-site diagnoses.

    Science.gov (United States)

    Fu, Qiangqiang; Wu, Ze; Li, Xiuqing; Yao, Cuize; Yu, Shiting; Xiao, Wei; Tang, Yong

    2016-07-15

    Microplate readers are important diagnostic instruments, used intensively for various readout test kits (biochemical analysis kits and ELISA kits). However, due to their expensive and non-portability, commercial microplate readers are unavailable for home testing, community and rural hospitals, especially in developing countries. In this study, to provide a field-portable, cost-effective and versatile diagnostic tool, we reported a novel smart phone based microplate reader. The basic principle of this devise relies on a smart phone's optical sensor that measures transmitted light intensities of liquid samples. To prove the validity of these devises, developed smart phone based microplate readers were applied to readout results of various analytical targets. These targets included analanine aminotransferase (ALT; limit of detection (LOD) was 17.54 U/L), alkaline phosphatase (AKP; LOD was 15.56 U/L), creatinine (LOD was 1.35μM), bovine serum albumin (BSA; LOD was 0.0041mg/mL), prostate specific antigen (PSA; LOD was 0.76pg/mL), and ractopamine (Rac; LOD was 0.31ng/mL). The developed smart phone based microplate readers are versatile, portable, and inexpensive; they are unique because of their ability to perform under circumstances where resources and expertize are limited. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. A versatile PCR-based tandem epitope tagging system for Streptomyces coelicolor genome.

    Science.gov (United States)

    Kim, Ji-Nu; Yi, Jeong Sang; Lee, Bo-Rahm; Kim, Eun-Jung; Kim, Min Woo; Song, Yoseb; Cho, Byung-Kwan; Kim, Byung-Gee

    2012-07-20

    Epitope tagging approaches have been widely used for the analysis of functions, interactions and subcellular distributions of proteins. However, incorporating epitope sequence into protein loci in Streptomyces is time-consuming procedure due to the absence of the versatile tagging methods. Here, we developed a versatile PCR-based tandem epitope tagging tool for the Streptomyces genome engineering. We constructed a series of template plasmids that carry repeated sequence of c-myc epitope, Flp recombinase target (FRT) sites, and apramycin resistance marker to insert epitope tags into any desired spot of the chromosomal loci. A DNA module which includes the tandem epitope-encoding sequence and a selectable marker was amplified by PCR with primers that carry homologous extensions to the last portion and downstream region of the targeted gene. We fused the epitope tags at the 3' region of global transcription factors of Streptomyces coelicolor to test the validity of this system. The proper insertion of the epitope tag was confirmed by PCR and western blot analysis. The recombinants showed the identical phenotype to the wild-type that proved the conservation of in vivo function of the tagged proteins. Finally, the direct binding targets were successfully detected by chromatin immunoprecipitation with the increase in the signal-to-noise ratio. The epitope tagging system describes here would provide wide applications to study the protein functions in S. coelicolor. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Platelet concentrates for topical use: bedside device and blood transfusion technology. Quality and versatility.

    Science.gov (United States)

    Borzini, Piero; Balbo, Valeria; Mazzucco, Laura

    2012-06-01

    More or less after a decade of experimental and pioneering manual procedures to prepare platelet-rich plasma (PRP) for topical use, several portable and bedside devices were made available to prepare the PRP at the point-of-care. This technical opportunity increased the number of patients who got access to the treatment with autologous PRP and PRP-gel. Since topical treatment of tissue with PRP and PRP-gel was restricted to autologous preparation, blood transfusion centers that professionally prepare donor-derived platelet concentrates were not able to cover the overwhelming request for autologous PRP supply. Principally for logistic and organization reasons blood transfusion centers usually fail the challenge of prompt delivery of PRP to the physician over large territory. Nevertheless the blood bank production of platelet concentrates is associated with high standardization and quality controls not achievable from bedside and portable devices. Furthermore it easy to demonstrate that high-volume blood bank-produced platelet concentrates are less expensive than low-volume PRP produced by portable and bedside devices. Taking also in consideration the ever-increasing safety of the blood components, the relationship between bedside device-produced and blood-bank-produced PRP might be reconsidered. Here we discuss this topic concluding that the variety of sources of PRP production is an opportunity for versatility and that, ultimately, versatility is an opportunity for the patient's care.

  3. A novel versatile microbiosensor for local hydrogen detection by means of scanning photoelectrochemical microscopy.

    Science.gov (United States)

    Zhao, Fangyuan; Conzuelo, Felipe; Hartmann, Volker; Li, Huaiguang; Stapf, Stefanie; Nowaczyk, Marc M; Rögner, Matthias; Plumeré, Nicolas; Lubitz, Wolfgang; Schuhmann, Wolfgang

    2017-08-15

    The development of a versatile microbiosensor for hydrogen detection is reported. Carbon-based microelectrodes were modified with a [NiFe]-hydrogenase embedded in a viologen-modified redox hydrogel for the fabrication of a sensitive hydrogen biosensor By integrating the microbiosensor in a scanning photoelectrochemical microscope, it was capable of serving simultaneously as local light source to initiate photo(bio)electrochemical reactions while acting as sensitive biosensor for the detection of hydrogen. A hydrogen evolution biocatalyst based on photosystem 1-platinum nanoparticle biocomplexes embedded into a specifically designed redox polymer was used as a model for proving the capability of the developed hydrogen biosensor for the detection of hydrogen upon localized illumination. The versatility and sensitivity of the proposed microbiosensor as probe tip allows simplification of the set-up used for the evaluation of complex electrochemical processes and the rapid investigation of local photoelectrocatalytic activity of biocatalysts towards light-induced hydrogen evolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Carbon Dots as Versatile Photosensitizers for Solar-Driven Catalysis with Redox Enzymes.

    Science.gov (United States)

    Hutton, Georgina A M; Reuillard, Bertrand; Martindale, Benjamin C M; Caputo, Christine A; Lockwood, Colin W J; Butt, Julea N; Reisner, Erwin

    2016-12-28

    Light-driven enzymatic catalysis is enabled by the productive coupling of a protein to a photosensitizer. Photosensitizers used in such hybrid systems are typically costly, toxic, and/or fragile, with limited chemical versatility. Carbon dots (CDs) are low-cost, nanosized light-harvesters that are attractive photosensitizers for biological systems as they are water-soluble, photostable, nontoxic, and their surface chemistry can be easily modified. We demonstrate here that CDs act as excellent light-absorbers in two semibiological photosynthetic systems utilizing either a fumarate reductase (FccA) for the solar-driven hydrogenation of fumarate to succinate or a hydrogenase (H2ase) for reduction of protons to H2. The tunable surface chemistry of the CDs was exploited to synthesize positively charged ammonium-terminated CDs (CD-NHMe2+), which were capable of transferring photoexcited electrons directly to the negatively charged enzymes with high efficiency and stability. Enzyme-based turnover numbers of 6000 mol succinate (mol FccA)-1 and 43,000 mol H2 (mol H2ase)-1 were reached after 24 h. Negatively charged carboxylate-terminated CDs (CD-CO2-) displayed little or no activity, and the electrostatic interactions at the CD-enzyme interface were determined to be essential to the high photocatalytic activity observed with CD-NHMe2+. The modular surface chemistry of CDs together with their photostability and aqueous solubility make CDs versatile photosensitizers for redox enzymes with great scope for their utilization in photobiocatalysis.

  5. Polydopamine Nanoparticles as a Versatile Molecular Loading Platform to Enable Imaging-guided Cancer Combination Therapy.

    Science.gov (United States)

    Dong, Ziliang; Gong, Hua; Gao, Min; Zhu, Wenwen; Sun, Xiaoqi; Feng, Liangzhu; Fu, Tingting; Li, Yonggang; Liu, Zhuang

    2016-01-01

    Cancer combination therapy to treat tumors with different therapeutic approaches can efficiently improve treatment efficacy and reduce side effects. Herein, we develop a theranostic nano-platform based on polydopamine (PDA) nanoparticles, which then are exploited as a versatile carrier to allow simultaneous loading of indocyanine green (ICG), doxorubicin (DOX) and manganese ions (PDA-ICG-PEG/DOX(Mn)), to enable imaging-guided chemo & photothermal cancer therapy. In this system, ICG acts as a photothermal agent, which shows red-shifted near-infrared (NIR) absorbance and enhanced photostability compared with free ICG. DOX, a model chemotherapy drug, is then loaded onto the surface of PDA-ICG-PEG with high efficiency. With Mn(2+) ions intrinsically chelated, PDA-ICG-PEG/DOX(Mn) is able to offer contrast under T1-weighted magnetic resonance (MR) imaging. In a mouse tumor model, the MR imaging-guided combined chemo- & photothermal therapy achieves a remarkable synergistic therapeutic effect compared with the respective single treatment modality. This work demonstrates that PDA nanoparticles could serve as a versatile molecular loading platform for MR imaging guided combined chemo- & photothermal therapy with minimal side effects, showing great potential for cancer theranostics.

  6. The Suzuki–Miyaura Cross-Coupling as a Versatile Tool for Peptide Diversification and Cyclization

    Directory of Open Access Journals (Sweden)

    Tom Willemse

    2017-02-01

    Full Text Available The (site-selective derivatization of amino acids and peptides represents an attractive field with potential applications in the establishment of structure–activity relationships and labeling of bioactive compounds. In this respect, bioorthogonal cross-coupling reactions provide valuable means for ready access to peptide analogues with diversified structure and function. Due to the complex and chiral nature of peptides, mild reaction conditions are preferred; hence, a suitable cross-coupling reaction is required for the chemical modification of these challenging substrates. The Suzuki reaction, involving organoboron species, is appropriate given the stability and environmentally benign nature of these reactants and their amenability to be applied in (partial aqueous reaction conditions, an expected requirement upon the derivatization of peptides. Concerning the halogenated reaction partner, residues bearing halogen moieties can either be introduced directly as halogenated amino acids during solid-phase peptide synthesis (SPPS or genetically encoded into larger proteins. A reversed approach building in boron in the peptidic backbone is also possible. Furthermore, based on this complementarity, cyclic peptides can be prepared by halogenation, and borylation of two amino acid side chains present within the same peptidic substrate. Here, the Suzuki–Miyaura reaction is a tool to induce the desired cyclization. In this review, we discuss diverse amino acid and peptide-based applications explored by means of this extremely versatile cross-coupling reaction. With the advent of peptide-based drugs, versatile bioorthogonal conversions on these substrates have become highly valuable.

  7. Versatile Large-Area Custom-Feature van der Waals Epitaxy of Topological Insulators.

    Science.gov (United States)

    Trivedi, Tanuj; Roy, Anupam; Movva, Hema C P; Walker, Emily S; Bank, Seth R; Neikirk, Dean P; Banerjee, Sanjay K

    2017-07-25

    As the focus of applied research in topological insulators (TI) evolves, the need to synthesize large-area TI films for practical device applications takes center stage. However, constructing scalable and adaptable processes for high-quality TI compounds remains a challenge. To this end, a versatile van der Waals epitaxy (vdWE) process for custom-feature bismuth telluro-sulfide TI growth and fabrication is presented, achieved through selective-area fluorination and modification of surface free-energy on mica. The TI features grow epitaxially in large single-crystal trigonal domains, exhibiting armchair or zigzag crystalline edges highly oriented with the underlying mica lattice and only two preferred domain orientations mirrored at 180°. As-grown feature thickness dependence on lateral dimensions and denuded zones at boundaries are observed, as explained by a semiempirical two-species surface migration model with robust estimates of growth parameters and elucidating the role of selective-area surface modification. Topological surface states contribute up to 60% of device conductance at room temperature, indicating excellent electronic quality. High-yield microfabrication and the adaptable vdWE growth mechanism with readily alterable precursor and substrate combinations lend the process versatility to realize crystalline TI synthesis in arbitrary shapes and arrays suitable for facile integration with processes ranging from rapid prototyping to scalable manufacturing.

  8. A versatile small form factor twisted-pair TFC FMC for MTCA AMCs

    Science.gov (United States)

    Meder, L.; Lebedev, J.; Becker, J.

    2017-03-01

    In continuous readout systems of particle physics experiments, the provision of a common clock and time reference and the distribution of critical low latency messages to the processing and fronted layers of the readout are crucial tasks. In the context of the Compressed Baryonic Matter (CBM) experiment, a versatile small form factor Timing and Fast-Control (TFC) interfacing FPGA Mezzanine Card (FMC) was developed, offering bidirectional twisted-pair (TP) links for the communication between TFC nodes. Also a versatile clocking including voltage controlled oscillators and a connection to the telecommunication clock lines of mTCA crates are available. Being designed for both TFC Master and Slaves, the card allows rapid system developments without additional Slave hardware circuits. Measurements show that it is possible to transmit over cable lengths of 25 m at a rate of 240 Mbit/s for all data channels simultaneously. A TFC Master-Slave system using two of these cards can be synchronized with a precision of ±10 ps to an user-defined phase setpoint.

  9. Thoracodorsal artery perforator fasciocutaneous flap: A versatile alternative for coverage of various soft tissue defects

    Directory of Open Access Journals (Sweden)

    Celalettin Sever

    2012-01-01

    Full Text Available Objective: The thoracodorsal artery perforator (TDAP flap has contributed to the efficient reconstruction of tissue defects that require a large amount of cutaneous tissue. The optimal reconstruction method should provide thin, and well-vascularized tissue with minimal donor-site morbidity. The indications for the use of this particular flap with other flaps are discussed in this article. Materials and Methods: Thirteen patients underwent soft tissue reconstruction using TDAP flaps between 2009 and 2011. Of those, there were four cases of antecubital burn contracture, three cases of axillary burn contracture, two cases of giant hair cell nevus of upper extremity, two cases of axillary reconstruction following severe recurrent hidradenitis, and two cases of crush injury. All patients were male and their ages ranged from 20 to 23 (average, 21 years. The mean follow-up period was 8 months (range, 4-22 months. Results: All reconstructive procedures were completed without any major complications. Minor complications related to transfered flaps were wound dehiscence in one case, transient venous congestion in two cases. Minor complication related to the donor site was seroma in one case. The success rate was 100%, with satisfactory cosmetic results. Conclusions: The TDAP flap is a safe and extremely versatile flap that offers significant advantages in acute and delayed reconstruction. Although the vascular anatomy may be variable, free and pedicled TDAP flap is a versatile alternative for soft tissue defects. It adapts very well to the soft tissue defects with acceptable donor site scar.

  10. A Versatile Bioreactor for Dynamic Suspension Cell Culture. Application to the Culture of Cancer Cell Spheroids.

    Science.gov (United States)

    Massai, Diana; Isu, Giuseppe; Madeddu, Denise; Cerino, Giulia; Falco, Angela; Frati, Caterina; Gallo, Diego; Deriu, Marco A; Falvo D'Urso Labate, Giuseppe; Quaini, Federico; Audenino, Alberto; Morbiducci, Umberto

    2016-01-01

    A versatile bioreactor suitable for dynamic suspension cell culture under tunable shear stress conditions has been developed and preliminarily tested culturing cancer cell spheroids. By adopting simple technological solutions and avoiding rotating components, the bioreactor exploits the laminar hydrodynamics establishing within the culture chamber enabling dynamic cell suspension in an environment favourable to mass transport, under a wide range of tunable shear stress conditions. The design phase of the device has been supported by multiphysics modelling and has provided a comprehensive analysis of the operating principles of the bioreactor. Moreover, an explanatory example is herein presented with multiphysics simulations used to set the proper bioreactor operating conditions for preliminary in vitro biological tests on a human lung carcinoma cell line. The biological results demonstrate that the ultralow shear dynamic suspension provided by the device is beneficial for culturing cancer cell spheroids. In comparison to the static suspension control, dynamic cell suspension preserves morphological features, promotes intercellular connection, increases spheroid size (2.4-fold increase) and number of cycling cells (1.58-fold increase), and reduces double strand DNA damage (1.5-fold reduction). It is envisioned that the versatility of this bioreactor could allow investigation and expansion of different cell types in the future.

  11. A versatile stereoscopic visual display system for vestibular and oculomotor research.

    Science.gov (United States)

    Kramer, P D; Roberts, D C; Shelhamer, M; Zee, D S

    1998-01-01

    Testing of the vestibular system requires a vestibular stimulus (motion) and/or a visual stimulus. We have developed a versatile, low cost, stereoscopic visual display system, using "virtual reality" (VR) technology. The display system can produce images for each eye that correspond to targets at any virtual distance relative to the subject, and so require the appropriate ocular vergence. We elicited smooth pursuit, "stare" optokinetic nystagmus (OKN) and after-nystagmus (OKAN), vergence for targets at various distances, and short-term adaptation of the vestibulo-ocular reflex (VOR), using both conventional methods and the stereoscopic display. Pursuit, OKN, and OKAN were comparable with both methods. When used with a vestibular stimulus, VR induced appropriate adaptive changes of the phase and gain of the angular VOR. In addition, using the VR display system and a human linear acceleration sled, we adapted the phase of the linear VOR. The VR-based stimulus system not only offers an alternative to more cumbersome means of stimulating the visual system in vestibular experiments, it also can produce visual stimuli that would otherwise be impractical or impossible. Our techniques provide images without the latencies encountered in most VR systems. Its inherent versatility allows it to be useful in several different types of experiments, and because it is software driven it can be quickly adapted to provide a new stimulus. These two factors allow VR to provide considerable savings in time and money, as well as flexibility in developing experimental paradigms.

  12. LEDWIRE: A Versatile Networking Platform for Smart LED Lighting Applications Using LIN-Bus and WSNs

    Directory of Open Access Journals (Sweden)

    Dimitrios D. Piromalis

    2016-05-01

    Full Text Available In this paper, the architecture of a versatile networking and control platform for Light-Emitting Diode (LED lighting applications is presented, based on embedded wireless and wired networking technologies. All the possible power and control signals distribution topologies of the lighting fixtures are examined with particular focus on dynamic lighting applications with design metrics as the cost, the required wiring installation expenses and maintenance complexity. The proposed platform is optimized for applications where the grouping of LED-based lighting fictures clusters is essential, as well as their synchronization. With such an approach, the distributed control and synchronization of LED lighting fixtures' clusters is performed through a versatile network that uses the single wire Local Interconnect Network (LIN bus. The proposed networking platform is presented in terms of its physical layer architecture, its data protocol configuration, and its functionality for smart control. As a proof of concept, the design of a LED lighting fixture together with a LIN-to-IEEE802.15.4/ZigBee data gateway is presented.

  13. Epidemiology of community-acquired bacterial meningitis

    NARCIS (Netherlands)

    Brouwer, Matthijs C.; van de Beek, Diederik

    2018-01-01

    The epidemiology of bacterial meningitis has been dynamic in the past 30 years following introduction of conjugated vaccines against Haemophilus influenzae type B, Streptococcus pneumoniae and Neisseria meningitidis. The purpose of this review is to describe recent developments in bacterial

  14. Adjunctive Corticosteroids in Adults with Bacterial Meningitis

    NARCIS (Netherlands)

    van de Beek, Diederik; de Gans, Jan

    2005-01-01

    Bacterial meningitis is a complex disorder in which neurologic injury is caused, in part, by the causative organism and, in part, by the host's own inflammatory response. In studies of experimental bacterial meningitis, adjuvant treatment with corticosteroids, specifically dexamethasone, has

  15. Dexamethasone in adults with bacterial meningitis

    NARCIS (Netherlands)

    de Gans, Jan; van de Beek, Diederik

    2002-01-01

    Background: Mortality and morbidity rates are high among adults with acute bacterial meningitis, especially those with pneumococcal meningitis. In studies of bacterial meningitis in animals, adjuvant treatment with corticosteroids has beneficial effects. Methods: We conducted a prospective,

  16. Cognitive outcome in adults after bacterial meningitis

    NARCIS (Netherlands)

    Hoogman, Martine; van de Beek, Diederik; Weisfelt, Martijn; de Gans, Jan; Schmand, Ben

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy

  17. Endocarditis in adults with bacterial meningitis

    NARCIS (Netherlands)

    Lucas, Marjolein J.; Brouwer, Matthijs C.; van der Ende, Arie; van de Beek, Diederik

    2013-01-01

    Endocarditis may precede or complicate bacterial meningitis, but the incidence and impact of endocarditis in bacterial meningitis are unknown. We assessed the incidence and clinical characteristics of patients with meningitis and endocarditis from a nationwide cohort study of adults with

  18. Cognitive outcome in adults after bacterial meningitis.

    NARCIS (Netherlands)

    Hoogman, M.; Beek, D. van de; Weisfelt, M.; Gans, J. de; Schmand, B.A.

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy

  19. Forensic identification using skin bacterial communities

    National Research Council Canada - National Science Library

    Noah Fierer; Christian L. Lauber; Nick Zhou; Daniel McDonald; Elizabeth K. Costello; Rob Knight; Jeffrey I. Gordon

    2010-01-01

    ... of bacterial communities. Given that skin bacterial communities are personalized, we hypothesized that we could use the residual skin bacteria left on objects for forensic identification, matching the bacteria on the object...

  20. Bacterial cells with improved tolerance to polyols

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds.......The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds....

  1. Bacterial cells with improved tolerance to polyamines

    DEFF Research Database (Denmark)

    2017-01-01

    Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds.......Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds....

  2. Zinc-Triggered Hydrogelation of Self-assembled Small Molecules to Inhibit Bacterial Growth

    Science.gov (United States)

    Xu, Chao; Cai, Yanbin; Ren, Chunhua; Gao, Jie; Hao, Jihui

    2015-01-01

    There is a significant need to develop antibacterial materials that could be applied locally and directly to the places surrounded by large amount of bacteria, in order to address the problems of bacterial antibiotic-resistance or irreversible biofilm formation. Hydrogels are thought to be suitable candidates due to their versatile applications in biomedical field. Among them, small molecular hydrogels have been paid lots of attention because they are easy to design and fabricate and often sensitive to external stimuli. Meanwhile, the antibacterial activity of metal ions are attracting more and more attention because resistance to them are not yet found within bacteria. We therefore designed the zinc ion binding peptide of Nap-GFFYGGGHGRGD, who can self-assemble into hydrogels after binds Zn2+ and inhibit the growth of bacteria due to the excellent antibacterial activity of Zn2+. Upon the addition of zinc ions, solutions containing Nap-GFFYGGGHGRGD transformed into supramolecular hydrogels composed of network of long nano-fibers. Bacterial tests revealed an antibacterial effect of the zinc triggered hydrogels on E. coli. The studied small molecular hydrogel shows great potential in locally addressing bacterial infections.

  3. Does the Future Engineer Force Transition Engineer Units between Offensive and Stability Operations in Ways That Achieve Responsiveness, Versatility, Agility, Effectiveness, and Efficiency?

    National Research Council Canada - National Science Library

    London, David T

    2005-01-01

    .... The main question is as follows: Does the FEF transition engineer units between offensive and stability operations in ways that achieve responsiveness, versatility, agility, effectiveness, and efficiency...

  4. The Bacterial Sequential Markov Coalescent.

    Science.gov (United States)

    De Maio, Nicola; Wilson, Daniel J

    2017-05-01

    Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example, leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions (homoplasies) inconsistent with the hypothesis of a single evolutionary tree. Bacterial recombination is typically modeled as statistically akin to gene conversion in eukaryotes, i.e. , using the coalescent with gene conversion (CGC). However, this model can be very computationally demanding as it needs to account for the correlations of evolutionary histories of even distant loci. So, with the increasing popularity of whole genome sequencing, the need has emerged for a faster approach to model and simulate bacterial genome evolution. We present a new model that approximates the coalescent with gene conversion: the bacterial sequential Markov coalescent (BSMC). Our approach is based on a similar idea to the sequential Markov coalescent (SMC)-an approximation of the coalescent with crossover recombination. However, bacterial recombination poses hurdles to a sequential Markov approximation, as it leads to strong correlations and linkage disequilibrium across very distant sites in the genome. Our BSMC overcomes these difficulties, and shows a considerable reduction in computational demand compared to the exact CGC, and very similar patterns in simulated data. We implemented our BSMC model within new simulation software FastSimBac. In addition to the decreased computational demand compared to previous bacterial genome evolution simulators, FastSimBac provides more general options for evolutionary scenarios, allowing population structure with migration, speciation, population size changes, and recombination hotspots. FastSimBac is

  5. Automation of a Versatile Crane (the LSMS) for Lunar Outpost Construction, Maintenance and Inspection

    Science.gov (United States)

    Doggett, William R.; Roithmayr, Carlos M.; Dorsey, John T.; Jones, Thomas C.; Shen, Haijun; Seywald, Hans; King, Bruce D.; Mikulas, Martin M., Jr.

    2009-01-01

    Devices for lifting, translating and precisely placing payloads are critical for efficient Earth-based construction operations. Both recent and past studies have demonstrated that devices with similar functionality will be needed to support lunar outpost operations. Although several designs have been developed for Earth based applications, these devices lack unique design characteristics necessary for transport to and use on the harsh lunar surface. These design characteristics include: a) lightweight components, b) compact packaging for launch, c) automated deployment, d) simple in-field reconfiguration and repair, and e) support for tele-operated or automated operations. Also, because the cost to transport mass to the lunar surface is very high, the number of devices that can be dedicated to surface operations will be limited. Thus, in contrast to Earth-based construction, where many single-purpose devices dominate a construction site, a lunar outpost will require a limited number of versatile devices that provide operational benefit from initial construction through sustained operations. The first generation test-bed of a new high performance device, the Lunar Surface Manipulation System (LSMS) has been designed, built and field tested. The LSMS has many unique features resulting in a mass efficient solution to payload handling on the lunar surface. Typically, the LSMS device mass is estimated at approximately 3% of the mass of the heaviest payload lifted at the tip, or 1.8 % of the mass of the heaviest mass lifted at the elbow or mid-span of the boom for a high performance variant incorporating advanced structural components. Initial operational capabilities of the LSMS were successfully demonstrated during field tests at Moses Lake, Washington using a tele-operated approach. Joint angle sensors have been developed for the LSMS to improve operator situational awareness. These same sensors provide the necessary information to support fully automated operations

  6. Whole genome sequencing of Microbacterium sp. AISO3 from polluted San Jacinto River sediment reveals high bacterial mobility, metabolic versatility and heavy metal resistance.

    Science.gov (United States)

    Iyer, Rupa; Damania, Ashish; Iken, Brian

    2017-12-01

    The genus Microbacterium is composed of high GC content, Gram-positive bacteria of the phylum Acintobacteria known for their antibiotic production. Microbacterium species commonly colonize agricultural rhizospheres and more infrequently have been found to colonize and infect human tissues as well. Here we report the 3,696,310 bp draft genome (chromosome and plasmids) sequence assembled at the scaffold level from 232 contigs of Microbacterium sp. strain AISO3, isolated from polluted San Jacinto River sediment in Channelview, Texas. The nucleotide sequence of this genome was deposited into NCBI GenBank under the accession NHRF00000000.

  7. A versatile-deployable bacterial detection system for food and environmental safety based on LabTube-automated DNA purification, LabReader-integrated amplification, readout and analysis.

    Science.gov (United States)

    Hoehl, Melanie M; Bocholt, Eva Schulte; Kloke, Arne; Paust, Nils; von Stetten, Felix; Zengerle, Roland; Steigert, Juergen; Slocum, Alexander H

    2014-06-07

    Contamination of foods is a public health hazard that episodically causes thousands of deaths and sickens millions worldwide. To ensure food safety and quality, rapid, low-cost and easy-to-use detection methods are desirable. Here, the LabSystem is introduced for integrated, automated DNA purification, amplification and detection. It consists of a disposable, centrifugally driven DNA purification platform (LabTube) and a low-cost UV/vis-reader (LabReader). For demonstration of the LabSystem in the context of food safety, purification of Escherichia coli (non-pathogenic E. coli and pathogenic verotoxin-producing E. coli (VTEC)) in water and milk and the product-spoiler Alicyclobacillus acidoterrestris (A. acidoterrestris) in apple juice was integrated and optimized in the LabTube. Inside the LabReader, the purified DNA was amplified, readout and analyzed using both qualitative isothermal loop-mediated DNA amplification (LAMP) and quantitative real-time PCR. For the LAMP-LabSystem, the combined detection limits for purification and amplification of externally lysed VTEC and A. acidoterrestris are 10(2)-10(3) cell-equivalents. In the PCR-LabSystem for E. coli cells, the quantification limit is 10(2) cell-equivalents including LabTube-integrated lysis. The demonstrated LabSystem only requires a laboratory centrifuge (to operate the disposable, fully closed LabTube) and a low-cost LabReader for DNA amplification, readout and analysis. Compared with commercial DNA amplification devices, the LabReader improves sensitivity and specificity by the simultaneous readout of four wavelengths and the continuous readout during temperature cycling. The use of a detachable eluate tube as an interface affords semi-automation of the LabSystem, which does not require specialized training. It reduces the hands-on time from about 50 to 3 min with only two handling steps: sample input and transfer of the detachable detection tube.

  8. The Bacterial Microflora of Fish

    Directory of Open Access Journals (Sweden)

    B. Austin

    2002-01-01

    Full Text Available The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen of healthy fish may contain bacteria, but there is debate on whether or not muscle is actually sterile. The numbers and taxonomic composition of the bacterial populations often reflect those of the surrounding water. The role of the bacteria includes the ability to degrade complex molecules (therefore exercising a potential benefit in nutrition, to produce vitamins and polymers, and to be responsible for the emission of light by the light-emitting organs of deep-sea fish. Taxa, including Pseudomonas, may contribute to spoilage by the production of histamines in fish tissue.

  9. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  10. Bacterial cheating limits antibiotic resistance

    Science.gov (United States)

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  11. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  12. Bacterial interactions in dental biofilm

    OpenAIRE

    Huang, Ruijie; Li, Mingyun; Gregory, Richard L

    2011-01-01

    Biofilms are masses of microorganisms that bind to and multiply on a solid surface, typically with a fluid bathing the microbes. The microorganisms that are not attached but are free-floating in an aqueous environment are termed planktonic cells. Traditionally, microbiology research has addressed results from planktonic bacterial cells. However, many recent studies have indicated that biofilms are the preferred form of growth of most microbes and particularly those of a pathogenic nature. Bio...

  13. Polymorphism in Bacterial Flagella Suspensions

    Science.gov (United States)

    Schwenger, Walter J.

    Bacterial flagella are a type of biological polymer studied for its role in bacterial motility and the polymorphic transitions undertaken to facilitate the run and tumble behavior. The naturally rigid, helical shape of flagella gives rise to novel colloidal dynamics and material properties. This thesis studies methods in which the shape of bacterial flagella can be controlled using in vitro methods and the changes the shape of the flagella have on both single particle dynamics and bulk material properties. We observe individual flagellum in both the dilute and semidilute regimes to observe the effects of solvent condition on the shape of the filament as well as the effect the filament morphology has on reptation through a network of flagella. In addition, we present rheological measurements showing how the shape of filaments effects the bulk material properties of flagellar suspensions. We find that the individual particle dynamics in suspensions of flagella can vary with geometry from needing to reptate linearly via rotation for helical filaments to the prevention of long range diffusion for block copolymer filaments. Similarly, for bulk material properties of flagella suspensions, helical geometries show a dramatic enhancement in elasticity over straight filaments while block copolymers form an elastic gel without the aid of crosslinking agents.

  14. Bacterial biofilm and associated infections.

    Science.gov (United States)

    Jamal, Muhsin; Ahmad, Wisal; Andleeb, Saadia; Jalil, Fazal; Imran, Muhammad; Nawaz, Muhammad Asif; Hussain, Tahir; Ali, Muhammad; Rafiq, Muhammad; Kamil, Muhammad Atif

    2018-01-01

    Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living). Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH) revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease. Copyright © 2017. Published by Elsevier Taiwan LLC.

  15. Acute bacterial meningitis in adults.

    Science.gov (United States)

    McGill, Fiona; Heyderman, Robert S; Panagiotou, Stavros; Tunkel, Allan R; Solomon, Tom

    2016-12-17

    Over the past several decades, the incidence of bacterial meningitis in children has decreased but there remains a significant burden of disease in adults, with a mortality of up to 30%. Although the pathogenesis of bacterial meningitis is not completely understood, knowledge of bacterial invasion and entry into the CNS is improving. Clinical features alone cannot determine whether meningitis is present and analysis of cerebrospinal fluid is essential for diagnosis. Newer technologies, such as multiplex PCR, and novel diagnostic platforms that incorporate proteomics and genetic sequencing, might help provide a quicker and more accurate diagnosis. Even with appropriate antimicrobial therapy, mortality is high and so attention has focused on adjunctive therapies; adjunctive corticosteroids are beneficial in certain circumstances. Any further improvements in outcome are likely to come from either modulation of the host response or novel approaches to therapy, rather than new antibiotics. Ultimately, the best hope to reduce the disease burden is with broadly protective vaccines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Neurological sequelae of bacterial meningitis.

    Science.gov (United States)

    Lucas, Marjolein J; Brouwer, Matthijs C; van de Beek, Diederik

    2016-07-01

    We reported on occurrence and impact of neurological sequelae after bacterial meningitis. We reviewed occurrence of neurological sequelae in children and adults after pneumococcal and meningococcal meningitis. Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy. Adults with pneumococcal meningitis have the highest risk of developing focal neurological deficits, which are most commonly caused by cerebral infarction, but can also be due to cerebritis, subdural empyema, cerebral abscess or intracerebral bleeding. Focal deficits may improve during clinical course and even after discharge, but a proportion of patients will have persisting focal neurological deficits that often interfere in patient's daily life. Hearing loss occurs in a high proportion of patients with pneumococcal meningitis and has been associated with co-existing otitis. Children and adults recovering from bacterial meningitis without apparent neurological deficits are at risk for long-term cognitive deficits. Early identification of neurological sequelae is important for children to prevent additional developmental delay, and for adults to achieve successful return in society after the disease. Neurological sequelae occur in a substantial amount of patients following bacterial meningitis. Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  17. Bacterial Infections Complicating Tongue Piercing

    Directory of Open Access Journals (Sweden)

    Catherine HY Yu

    2010-01-01

    Full Text Available Tongue piercing has become an increasingly popular form of body art. However, this procedure can occasionally be complicated by serious bacterial infections. The present article reports a case of prosthetic valve endocarditis caused by a Gemella species in a patient with a pierced tongue, and reviews 18 additional cases of local and systemic bacterial infections associated with tongue piercing. Infections localized to the oral cavity and head and neck region included molar abscess, glossal abscess, glossitis, submandibular lymphadenitis, submandibular sialadenitis, Ludwig’s angina and cephalic tetanus. Infections distal to the piercing site included eight cases of infective endocarditis, one case of chorioamnionitis and one case of cerebellar abscess. Oropharyngeal flora were isolated from all cases. While bacterial infections following tongue piercing are rare, there are reports of potentially life-threatening infections associated with the procedure. Both piercers and their clients should be aware of these potential complications, and standardized infection prevention and control practices should be adopted by piercers to reduce the risk.

  18. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  19. Bacterial sex in dental plaque

    Directory of Open Access Journals (Sweden)

    Ingar Olsen

    2013-06-01

    Full Text Available Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

  20. Bacterial biofilm and associated infections

    Directory of Open Access Journals (Sweden)

    Muhsin Jamal

    2018-01-01

    Full Text Available Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living. Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

  1. Sulfate decomposition by bacterial leaching

    Energy Technology Data Exchange (ETDEWEB)

    Deveci, N.; Delaloglu, C.G. [Istanbul Technical Univ. (Turkey)

    1995-04-01

    Sulfate disposal is the main problem of many industrial effluents, such as excess sulfuric acid, gypsum, coal desulfurization byproducts, acid-mine waters, and general metallurgical effluents. It has been established that sulfate present in wastes can be converted to elemental sulfur by bacterial mutualism. This study presents the results of an investigation of the industrial feasibility of utilizing a biological system capable of converting hydrous calcium sulfate (gypsum) to elemental sulfur. Gypsum, which was used in this study, is a byproduct of the fertilizer industry. The biological system is referred to as a bacterial mutualism, and involves Desulfovibrio desulfuricans for sulfate conversion and Chlorobium thiosulfatophilum for hydrogen sulfide conversion. Bacterial mutualism and utilization of sulfate were investigated by means of a two-stage anaerobic system. In the first stage, a gas purge system was used for sulfate conversion to sulfide, and it was found that maximum conversion is 34%. In the second stage, a static culture system was used for sulfide conversion to sulfur with a conversion of 92%. 14 refs., 5 tabs.

  2. Conformational control of the bacterial Clp protease by natural product antibiotics.

    Science.gov (United States)

    Malik, I T; Brötz-Oesterhelt, H

    2017-07-06

    Covering: up to 2017The bacterial Clp protease is a highly conserved and structurally versatile machine. It has gained a lot of recognition during the last decade as a novel antibacterial drug target with an unprecedented mechanism of action. Due to its complexity, there are distinct means of interfering with its natural functions and several compounds targeting this machine have been identified. In this review, we summarize the current state of knowledge about natural products deregulating Clp proteolysis, a crucial and delicate process within the cell. Among those, acyldepsipeptide antibiotics of the ADEP class (ADEPs) are characterized best. The molecular mechanism of ADEP-mediated deregulation sheds light on the inner workings of the Clp protease.

  3. Discovery of a novel (R-selective bacterial hydroxynitrile lyase from Acidobacterium capsulatum

    Directory of Open Access Journals (Sweden)

    Romana Wiedner

    2014-06-01

    Full Text Available Hydroxynitrile lyases (HNLs are powerful carbon–carbon bond forming enzymes. The reverse of their natural reaction – the stereoselective addition of hydrogen cyanide (HCN to carbonyls – yields chiral cyanohydrins, versatile building blocks for the pharmaceutical and chemical industry. Recently, bacterial HNLs have been discovered, which represent a completely new type: HNLs with a cupin fold. Due to various benefits of cupins (e.g. high yield recombinant expression in Escherichia coli, the class of cupin HNLs provides a new source for interesting, powerful hydroxynitrile lyases in the ongoing search for HNLs with improved activity, enantioselectivity, stability and substrate scope. In this study, database mining revealed a novel cupin HNL from Acidobacterium capsulatum ATCC 51196 (AcHNL, which was able to catalyse the (R-selective synthesis of mandelonitrile with significantly better conversion (97% and enantioselectivity (96.7% than other cupin HNLs.

  4. Discovery of a novel (R)-selective bacterial hydroxynitrile lyase from Acidobacterium capsulatum.

    Science.gov (United States)

    Wiedner, Romana; Gruber-Khadjawi, Mandana; Schwab, Helmut; Steiner, Kerstin

    2014-06-01

    Hydroxynitrile lyases (HNLs) are powerful carbon-carbon bond forming enzymes. The reverse of their natural reaction - the stereoselective addition of hydrogen cyanide (HCN) to carbonyls - yields chiral cyanohydrins, versatile building blocks for the pharmaceutical and chemical industry. Recently, bacterial HNLs have been discovered, which represent a completely new type: HNLs with a cupin fold. Due to various benefits of cupins (e.g. high yield recombinant expression in Escherichia coli), the class of cupin HNLs provides a new source for interesting, powerful hydroxynitrile lyases in the ongoing search for HNLs with improved activity, enantioselectivity, stability and substrate scope. In this study, database mining revealed a novel cupin HNL from Acidobacterium capsulatum ATCC 51196 (AcHNL), which was able to catalyse the (R)-selective synthesis of mandelonitrile with significantly better conversion (97%) and enantioselectivity (96.7%) than other cupin HNLs.

  5. The Necessary Nitrogen Atom: A Versatile High-Impact Design Element for Multiparameter Optimization.

    Science.gov (United States)

    Pennington, Lewis D; Moustakas, Demetri T

    2017-05-11

    There is a continued desire in biomedical research to reduce the number and duration of design cycles required to optimize lead compounds into high-quality chemical probes or safe and efficacious drug candidates. The insightful application of impactful molecular design elements is one approach toward achieving this goal. The replacement of a CH group with a N atom in aromatic and heteroaromatic ring systems can have many important effects on molecular and physicochemical properties and intra- and intermolecular interactions that can translate to improved pharmacological profiles. In this Perspective, the "necessary nitrogen atom" is shown to be a versatile high-impact design element for multiparameter optimization, wherein ≥10-, 100-, or 1000-fold improvement in a variety of key pharmacological parameters can be realized.

  6. EEI`s wafer-cell bipolar battery: Versatile technology for a variety of military systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.T.; Klein, M.G.; Reisner, D.E. [Electro Energy, Inc., Danbury, CT (United States)

    1996-11-01

    A new versatile cell design based on stackable wafer cells is described which forms the unit building block of a new generation of bipolar battery systems for a wide variety of military applications. Current is transported across an outer envelope of conductive plastic film. This innovative bipolar design approach offers improved energy density based on more efficient packaging in prismatic containers as well as elimination of cell hardware. Higher power capability is achieved from the intrinsic low resistance operation in a bipolar mode. These performance improvements are achieved in a low-cost package by virtue of the design simplicity and use of non-graphitic plastic-bonded electrodes. EEI has demonstrated the viability of the wafer cell approach in Ni-MH with sealed cell cycle life in excess of 2,000 cycles. Results are also reported for Ag-MH.

  7. A Versatile Synthesis of 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB)

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R; Pagoria, P F; Schmidt, R D; Coburn, M D; Lee, G S; Hsu, P C

    2006-04-06

    A safe and versatile synthesis of high-purity 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) based on vicarious nucleophilic substitution (VNS) chemistry has now been achieved. The starting material can be selected from a variety of inexpensive nitroarenes obtained from commercial suppliers (4-nitroaniline, picric acid) or U.S. stockpiles (ammonium picrate, TNT). The use of picric acid and ammonium picrate (Explosive D) is preferred as both compounds are directly converted to picramide in the presence of ammonium salts (diammonium hydrogen phosphate, ammonium carbamate) in sulfolane at elevated temperature. The picramide resulting from this process is directly converted to TATB using an optimized VNS reaction employing inexpensive hydroxylamine as the nucleophilic aminating reagent. A crucial element in our synthesis is a novel and efficient purification of TATB.

  8. Dendrimers and Dendrons as Versatile Building Blocks for the Fabrication of Functional Hydrogels.

    Science.gov (United States)

    Kaga, Sadik; Arslan, Mehmet; Sanyal, Rana; Sanyal, Amitav

    2016-04-15

    Hydrogels have emerged as a versatile class of polymeric materials with a wide range of applications in biomedical sciences. The judicious choice of hydrogel precursors allows one to introduce the necessary attributes to these materials that dictate their performance towards intended applications. Traditionally, hydrogels were fabricated using either polymerization of monomers or through crosslinking of polymers. In recent years, dendrimers and dendrons have been employed as well-defined building blocks in these materials. The multivalent and multifunctional nature of dendritic constructs offers advantages in either formulation or the physical and chemical properties of the obtained hydrogels. This review highlights various approaches utilized for the fabrication of hydrogels using well-defined dendrimers, dendrons and their polymeric conjugates. Examples from recent literature are chosen to illustrate the wide variety of hydrogels that have been designed using dendrimer- and dendron-based building blocks for applications, such as sensing, drug delivery and tissue engineering.

  9. A versatile atomic force microscope integrated with a scanning electron microscope

    Science.gov (United States)

    Kreith, J.; Strunz, T.; Fantner, E. J.; Fantner, G. E.; Cordill, M. J.

    2017-05-01

    A versatile atomic force microscope (AFM), which can be installed in a scanning electron microscope (SEM), is introduced. The flexible design of the instrument enables correlated analysis for different experimental configurations, such as AFM imaging directly after nanoindentation in vacuum. In order to demonstrate the capabilities of the specially designed AFM installed inside a SEM, slip steps emanating around nanoindents in single crystalline brass were examined. This example showcases how the combination of AFM and SEM imaging can be utilized for quantitative dislocation analysis through the measurement of the slip step heights without the hindrance of oxide formation. Finally, an in situ nanoindentation technique is introduced, illustrating the use of AFM imaging during indentation experiments to examine plastic deformation occurring under the indenter tip. The mechanical indentation data are correlated to the SEM and AFM images to estimate the number of dislocations emitted to the surface.

  10. MK Versatile spring: A Novel approach for intraoral maxillary molar distalization

    Directory of Open Access Journals (Sweden)

    Manish Kumar Gupta

    2015-01-01

    Full Text Available Molar distalisation is method of choice for gaining space in mild crowding cases as well as non-extraction treatment of patients having Class II Div 1 malocclusion. Through this paper we present a clinical innovation "MK" versatile spring for efficient tooth distalisation and mesialiation by inter-changing the positon of the helices. "MK" spring is made by 0.017΍ × 0.025΍ TMA wire in "M" configuration. It consists of 2 helices, one at the central arm and the other at the arm close to the tooth being mesialized or distalized. The helices are 2 mm in diameter and the length of the arm is 6 mm. The article presents 2 case reports where the effictiveness and efficiency of "MK" spring have been highlighted.

  11. Ni-Mn based alloys as versatile catalyst for different electrochemical reactions

    Science.gov (United States)

    Aaboubi, Omar; Ali-Omar, Ahmed-Yassin; Dzoyem, Eunice; Marthe, Jimmy; Boudifa, Mohamed

    2014-12-01

    To develop large scale use of hydrogen and fuel cells as a renewable energy source it is need to increase their durability and reduce their cost mainly due to the use of precious metals. We have examined new type of the low cost binary nickel-manganese (Ni-Mn) catalysts electrodeposited from ammonium chloride bath onto copper substrates. By varying bath composition, polarization potential and essentially bath temperature the operating deposition conditions were optimized to produce Ni-Mn coatings with high active surface (e.g. spongy aspect). The outstanding catalytic activity, the durability and the versatility of the deposited films have been characterized in basic media using several electrochemical processes, such as hydrogen evolution reaction (HER), water oxidation reaction (OER) and ethanol oxidation reaction (EOR).

  12. Versatile robotic interface to evaluate, enable and train locomotion and balance after neuromotor disorders.

    Science.gov (United States)

    Dominici, Nadia; Keller, Urs; Vallery, Heike; Friedli, Lucia; van den Brand, Rubia; Starkey, Michelle L; Musienko, Pavel; Riener, Robert; Courtine, Grégoire

    2012-07-01

    Central nervous system (CNS) disorders distinctly impair locomotor pattern generation and balance, but technical limitations prevent independent assessment and rehabilitation of these subfunctions. Here we introduce a versatile robotic interface to evaluate, enable and train pattern generation and balance independently during natural walking behaviors in rats. In evaluation mode, the robotic interface affords detailed assessments of pattern generation and dynamic equilibrium after spinal cord injury (SCI) and stroke. In enabling mode,the robot acts as a propulsive or postural neuroprosthesis that instantly promotes unexpected locomotor capacities including overground walking after complete SCI, stair climbing following partial SCI and precise paw placement shortly after stroke. In training mode, robot-enabled rehabilitation, epidural electrical stimulation and monoamine agonists reestablish weight-supported locomotion, coordinated steering and balance in rats with a paralyzing SCI. This new robotic technology and associated concepts have broad implications for both assessing and restoring motor functions after CNS disorders, both in animals and in humans.

  13. Versatile microwave-driven trapped ion spin system for quantum information processing.

    Science.gov (United States)

    Piltz, Christian; Sriarunothai, Theeraphot; Ivanov, Svetoslav S; Wölk, Sabine; Wunderlich, Christof

    2016-07-01

    Using trapped atomic ions, we demonstrate a tailored and versatile effective spin system suitable for quantum simulations and universal quantum computation. By simply applying microwave pulses, selected spins can be decoupled from the remaining system and, thus, can serve as a quantum memory, while simultaneously, other coupled spins perform conditional quantum dynamics. Also, microwave pulses can change the sign of spin-spin couplings, as well as their effective strength, even during the course of a quantum algorithm. Taking advantage of the simultaneous long-range coupling between three spins, a coherent quantum Fourier transform-an essential building block for many quantum algorithms-is efficiently realized. This approach, which is based on microwave-driven trapped ions and is complementary to laser-based methods, opens a new route to overcoming technical and physical challenges in the quest for a quantum simulator and a quantum computer.

  14. [The GIPSY-RECPAM model: a versatile approach for integrated evaluation in cardiologic care].

    Science.gov (United States)

    Carinci, F

    2009-01-01

    Tree-structured methodology applied for the GISSI-PSICOLOGIA project, although performed in the framework of earliest GISSI studies, represents a powerful tool to analyze different aspects of cardiologic care. The GISSI-PSICOLOGIA project has delivered a novel methodology based on the joint application of psychometric tools and sophisticated statistical techniques. Its prospective use could allow building effective epidemiological models relevant to the prognosis of the cardiologic patient. The various features of the RECPAM method allow a versatile use in the framework of modern e-health projects. The study used the Cognitive Behavioral Assessment H Form (CBA-H) psychometrics scales. The potential for its future application in the framework of Italian cardiology is relevant and particularly indicated to assist planning of systems for integrated care and routine evaluation of the cardiologic patient.

  15. Mapping dynamic branch displacements: A versatile method to quantify spatiotemporal neurite dynamics

    Directory of Open Access Journals (Sweden)

    Masaki eHiramoto

    2011-09-01

    Full Text Available AbstractQuantification of the movement of axons and dendrites is essential to study circuit formation. Several methods have been developed to quantify the movement of neurites in simplified systems, however these quantification methods are specialized for a limited type of predicted movements in the particular assay systems. The movement of neurites in vivo includes many unexpected rearrangements. Establishment of a method that can detect and quantify a variety of patterning events will reveal novel phenomena in circuit formation and make it possible to conduct deeper investigation of the molecular and cellular bases of these events. Here we present a versatile method that represents a quantitative analysis of the integrated movement of neurites on a spatial map. We show that the method is useful to analyze several types of neurite behaviors, such as changes in the directionality of neurite movements, fasciculation of axons or changes in territories of dendritic fields.

  16. Towards versatile and sustainable hydrogen production via electrocatalytic water splitting: Electrolyte engineering

    KAUST Repository

    Shinagawa, Tatsuya

    2016-12-17

    Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. The electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances where water splitting reaction is conducted, required solution conditions such as the identity and molarity of ions may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate developing efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), electrode stability, and/or indirectly impacts the performance by influencing concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions.

  17. Versatile Nanosystem-Based Cancer Theranostics: Design Inspiration and Predetermined Routing.

    Science.gov (United States)

    Opoku-Damoah, Yaw; Wang, Ruoning; Zhou, Jianping; Ding, Yang

    2016-01-01

    The relevance of personalized medicine, aimed at a more individualized drug therapy, has inspired research into nano-based concerted diagnosis and therapeutics (theranostics). As the intention is to "kill two birds with one stone", scientists have already described the emerging concept as a treasured tailor for the future of cancer therapy, wherein the main idea is to design "smart" nanosystems to concurrently discharge both therapeutic and diagnostic roles. These nanosystems are expected to offer a relatively clearer view of the ingenious cellular trafficking pathway, in-situ diagnosis, and therapeutic efficacy. We herein present a detailed review of versatile nanosystems, with prominent examples of recently developed intelligent delivery strategies which have gained attention in the field of theranostics. These nanotheranostics include various mechanisms programmed in novel platforms to enable predetermined delivery of cargo to specific sites, as well as techniques to overcome the notable challenges involved in the efficacy of theranostics.

  18. Implementation of a versatile research data acquisition system using a commercially available medical ultrasound scanner

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Nikolov, Svetoslav Ivanov; Pedersen, Mads Møller

    2012-01-01

    This paper describes the design and implementation of a versatile, open-architecture research data acquisition system using a commercially available medical ultrasound scanner. The open architecture will allow researchers and clinicians to rapidly develop applications and move them relatively easy...... to the clinic. The system consists of a standard PC equipped with a camera link and an ultrasound scanner equipped with a research interface. The ultrasound scanner is an easy-to-use imaging device that is capable of generating high-quality images. In addition to supporting the acquisition of multiple data...... to give researchers and clinicians the ability to utilize third-party software for data analysis and flexible manipulation of control parameters. Because of the advantages of speed of acquisition and clinical benefit, research projects have successfully used the system to test and implement...

  19. A Versatile System for USER Cloning-Based Assembly of Expression Vectors for Mammalian Cell Engineering

    DEFF Research Database (Denmark)

    Lund, Anne Mathilde; Kildegaard, Helene Faustrup; Petersen, Maja Borup Kjær

    2014-01-01

    A new versatile mammalian vector system for protein production, cell biology analyses, and cell factory engineering was developed. The vector system applies the ligation-free uracil-excision based technique – USER cloning – to rapidly construct mammalian expression vectors of multiple DNA fragments...... efficiency above 90%. The functionality of basic vectors for FAST assembly was tested and validated by transient expression of fluorescent model proteins in CHO, U-2-OS and HEK293 cell lines. In this test, we included many of the most common vector elements for heterologous gene expression in mammalian cells......, in addition the system is fully extendable by other users. The vector system is designed to facilitate high-throughput genome-scale studies of mammalian cells, such as the newly sequenced CHO cell lines, through the ability to rapidly generate high-fidelity assembly of customizable gene expression vectors....

  20. Harnessing the Versatility of Continuous-Flow Processes: Selective and Efficient Reactions.

    Science.gov (United States)

    Mándity, István M; Ötvös, Sándor B; Szőlősi, György; Fülöp, Ferenc

    2016-06-01

    There is a great need for effective transformations and a broad range of novel chemical entities. Continuous-flow (CF) approaches are of considerable current interest: highly efficient and selective reactions can be performed in CF reactors. The reaction setup of CF reactors offers a wide variety of possible points where versatility can be introduced. This article presents a number of selective and highly efficient gas-liquid-solid and liquid-solid reactions involving a range of reagents and immobilized catalysts. Enantioselective transformations through catalytic hydrogenation and organocatalytic reactions are included, and isotopically labelled compounds and pharmaceutically relevant 1,2,3-triazoles are synthesized in CF reactors. Importantly, the catalyst bed can be changed to a solid-phase peptide synthesis resin, with which peptide synthesis can be performed with the utilization of only 1.5 equivalents of the amino acid. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Manipulating waves with LEGO{sup ®} bricks: A versatile experimental platform for metamaterial architectures

    Energy Technology Data Exchange (ETDEWEB)

    Celli, Paolo, E-mail: pcelli@umn.edu; Gonella, Stefano, E-mail: sgonella@umn.edu [Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-08-24

    In this letter, we discuss a versatile, fully reconfigurable experimental platform for the investigation of phononic phenomena in metamaterial architectures. The approach revolves around the use of 3D laser vibrometry to reconstruct global and local wavefield features in specimens obtained through simple arrangements of LEGO{sup ®} bricks on a thin baseplate. The agility by which it is possible to reconfigure the brick patterns into a nearly endless spectrum of topologies makes this an effective approach for rapid experimental proof of concept, as well as a powerful didactic tool, in the arena of phononic crystals and metamaterials engineering. We use our platform to provide a compelling visual illustration of important spatial wave manipulation effects (waveguiding and seismic isolation), and to elucidate fundamental dichotomies between Bragg-based and locally resonant bandgap mechanisms.

  2. Developing the IBA equipment to increase the versatility of the CNA

    Energy Technology Data Exchange (ETDEWEB)

    Morilla, Y., E-mail: ymorilla@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Thomas Alva Edison 7, E-41092 Sevilla (Spain); Jimenez-Ramos, M.C., E-mail: mcyjr@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Thomas Alva Edison 7, E-41092 Sevilla (Spain); Garcia Lopez, J., E-mail: fjgl@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Thomas Alva Edison 7, E-41092 Sevilla (Spain); Labrador, J.A., E-mail: labrador@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Thomas Alva Edison 7, E-41092 Sevilla (Spain); Palomo, F.R., E-mail: rogelio@gte.esi.us.es [Departamento de Ingenieria Electronica, Escuela Superior de Ingenieros, Universidad de Sevilla, Descubrimientos s/n, E-41092 Sevilla (Spain); Ortega-Feliu, I., E-mail: iofeliu@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Thomas Alva Edison 7, E-41092 Sevilla (Spain)

    2012-02-15

    The Centro Nacional de Aceleradores (CNA) in Sevilla-Spain currently contains three accelerators: two tandems and a compact 18/9 cyclotron. Next year, a {sup 60}Co irradiation system will also be installed. This equipment will expand the range of irradiation experiments in the Centre using both charged particles as well as gamma-ray photons. Originally, based on the 3 MV tandem accelerator, the CNA was considered as a multidisciplinary research Centre devoted basically to the materials characterization by IBA techniques. Nowadays, the validity of our low-energy accelerators has been verified not only to perform analysis but also for irradiation testing, a very promising field of work since radiation effects are aggravated with the technology decreasing scales. In this work, the last innovations and modifications of our laboratory will be briefly described, emphasizing with respect to high energy PIXE experiments and its versatility to carry out irradiation tests.

  3. Versatile, tannic acid-mediated surface PEGylation for marine antifouling applications.

    Science.gov (United States)

    Kim, Suyeob; Gim, Taewoo; Kang, Sung Min

    2015-04-01

    In this study, we report a facile and versatile approach to the formation of marine antifouling surface coatings. The approach consists of a combined coating of polydopamine (pDA) and tannic acid (TA) and subsequent immobilization of polyethylene glycol (PEG) on solid substrates. TA coating of a pDA-coated surface was carried out using iron(III) coordination chemistry, and PEG was immobilized on the TA-coated surface via hydrogen bond formation. Stainless steel and nylon were successfully modified by this approach, and the resulting substrates were used for marine antifouling applications, in which diatom adhesion was significantly inhibited. Advantageously, this approach allowed marine antifouling coatings to be prepared by a simple immersion process under environmentally friendly conditions.

  4. Versatile Platform for the Synthesis of Orthogonally Cleavable Heteromultifunctional Cross-Linkers.

    Science.gov (United States)

    Sorkin, Michelle R; Walker, Joshua A; Brown, Joseph S; Alabi, Christopher A

    2017-04-19

    Cleavable and heteromultifunctional cross-linkers have proven critical in a wide range of biological applications. Traditional approaches for synthesizing these linkers suffer from various synthetic and functional limitations. In this work, an efficient sequence-defined synthetic methodology, developed for the assembly of oligothioetheramides, was used to address many of these limitations. Four heterotrifunctional cross-linkers with up to two orthogonal internal cleavage sites were synthesized. These linkers were conjugated to a pair of fluorophores that undergo Förster resonance energy transfer (FRET) and a model protein-human transferrin. Orthogonal bond cleavage was validated by mass spectrometry, fluorescent gel electrophoresis, and confocal microscopy. These studies demonstrate the versatility and biological utility of oligothioetheramides as a new class of multifunctional chemical cross-linkers and biologically relevant fluorescent probes.

  5. Filter-Aided Sample Preparation: The Versatile and Efficient Method for Proteomic Analysis.

    Science.gov (United States)

    Wiśniewski, J R

    2017-01-01

    Filter-aided sample preparation (FASP) is a versatile and efficient way of processing protein extracts for bottom-up proteomic analysis. The method repurposes centrifugal ultrafiltration concentrators for removal of detergents, protein cleavage, and isolation of pure peptide fractions. FASP can be used for protein cleavage with different proteinases either with single enzymes or in a mode of successive multienzyme digestion (MED)-FASP. The FASP methods are useful for processing of samples ranging in their sizes from submicrogram to several milligram amounts of total protein. They also allow peptide fractionation, and isolation and quantitation of total RNA and DNA acid contents. This chapter describes principles, limitations, and applications of FASP. Additionally detailed FASP and MED-FASP protocols are provided. © 2017 Elsevier Inc. All rights reserved.

  6. Versatile microsphere attachment of GFP-labeled motors and other tagged proteins with preserved functionality

    Directory of Open Access Journals (Sweden)

    Michael Bugiel

    2015-11-01

    Full Text Available Microspheres are often used as handles for protein purification or force spectroscopy. For example, optical tweezers apply forces on trapped particles to which motor proteins are attached. However, even though many attachment strategies exist, procedures are often limited to a particular biomolecule and prone to non-specific protein or surface attachment. Such interactions may lead to loss of protein functionality or microsphere clustering. Here, we describe a versatile coupling procedure for GFP-tagged proteins via a polyethylene glycol linker preserving the functionality of the coupled proteins. The procedure combines well-established protocols, is highly reproducible, reliable, and can be used for a large variety of proteins. The coupling is efficient and can be tuned to the desired microsphere-to-protein ratio. Moreover, microspheres hardly cluster or adhere to surfaces. Furthermore, the procedure can be adapted to different tags providing flexibility and a promising attachment strategy for any tagged protein.

  7. Atomic layer deposition (ALD): A versatile technique for plasmonics and nanobiotechnology.

    Science.gov (United States)

    Im, Hyungsoon; Wittenberg, Nathan J; Lindquist, Nathan C; Oh, Sang-Hyun

    2012-02-28

    While atomic layer deposition (ALD) has been used for many years as an industrial manufacturing method for microprocessors and displays, this versatile technique is finding increased use in the emerging fields of plasmonics and nanobiotechnology. In particular, ALD coatings can modify metallic surfaces to tune their optical and plasmonic properties, to protect them against unwanted oxidation and contamination, or to create biocompatible surfaces. Furthermore, ALD is unique among thin-film deposition techniques in its ability to meet the processing demands for engineering nanoplasmonic devices, offering conformal deposition of dense and ultra-thin films on high-aspect-ratio nanostructures at temperatures below 100 °C. In this review, we present key features of ALD and describe how it could benefit future applications in plasmonics, nanosciences, and biotechnology.

  8. Versatile, high sensitivity, and automatized angular dependent vectorial Kerr magnetometer for the analysis of nanostructured materials.

    Science.gov (United States)

    Teixeira, J M; Lusche, R; Ventura, J; Fermento, R; Carpinteiro, F; Araujo, J P; Sousa, J B; Cardoso, S; Freitas, P P

    2011-04-01

    Magneto-optical Kerr effect (MOKE) magnetometry is an indispensable, reliable, and one of the most widely used techniques for the characterization of nanostructured magnetic materials. Information, such as the magnitude of coercive fields or anisotropy strengths, can be readily obtained from MOKE measurements. We present a description of our state-of-the-art vectorial MOKE magnetometer, being an extremely versatile, accurate, and sensitivity unit with a low cost and comparatively simple setup. The unit includes focusing lenses and an automatized stepper motor stage for angular dependent measurements. The performance of the magnetometer is demonstrated by hysteresis loops of Co thin films displaying uniaxial anisotropy induced on growth, MnIr/CoFe structures exhibiting the so called exchange bias effect, spin valves, and microfabricated flux guides produced by optical lithography. © 2011 American Institute of Physics

  9. Two-Dimensional Stoichiometric Boron Oxides as a Versatile Platform for Electronic Structure Engineering.

    Science.gov (United States)

    Zhang, Ruiqi; Li, Zhenyu; Yang, Jinlong

    2017-09-21

    Oxides of two-dimensional (2D) atomic crystals have been widely studied due to their unique properties. In most 2D oxides, oxygen acts as a functional group, which makes it difficult to control the degree of oxidation. Because borophene is an electron-deficient system, it is expected that oxygen will be intrinsically incorporated into the basal plane of borophene, forming stoichiometric 2D boron oxide (BO) structures. By using first-principles global optimization, we systematically explore structures and properties of 2D BO systems with well-defined degrees of oxidation. Stable B-O-B and OB3 tetrahedron structure motifs are identified in these structures. Interesting properties, such as strong linear dichroism, Dirac node-line (DNL) semimetallicity, and negative differential resistance, have been predicted for these systems. Our results demonstrate that 2D BO represents a versatile platform for electronic structure engineering via tuning the stoichiometric degree of oxidation, which leads to various technological applications.

  10. A Versatile Multiple Target Detection System Based on DNA Nano-assembled Linear FRET Arrays.

    Science.gov (United States)

    Li, Yansheng; Du, Hongwu; Wang, Wenqian; Zhang, Peixun; Xu, Liping; Wen, Yongqiang; Zhang, Xueji

    2016-05-27

    DNA molecules have been utilized both as powerful synthetic building blocks to create nanoscale architectures and as inconstant programmable templates for assembly of biosensors. In this paper, a versatile, scalable and multiplex detection system is reported based on an extending fluorescent resonance energy transfer (FRET) cascades on a linear DNA assemblies. Seven combinations of three kinds of targets are successfully detected through the changes of fluorescence spectra because of the three-steps FRET or non-FRET continuity mechanisms. This nano-assembled FRET-based nanowire is extremely significant for the development of rapid, simple and sensitive detection system. The method used here could be extended to a general platform for multiplex detection through more-step FRET process.

  11. Experimental Study on Inkjet-Printed Passive UHF RFID Tags on Versatile Paper-Based Substrates

    Directory of Open Access Journals (Sweden)

    Han He

    2016-01-01

    Full Text Available We present the possibilities and challenges of passive UHF RFID tag antennas manufactured by inkjet printing silver nanoparticle ink on versatile paper-based substrates. The most efficient manufacturing parameters, such as the pattern resolution, were determined and the optimal number of printed layers was evaluated for each substrate material. Next, inkjet-printed passive UHF RFID tags were fabricated on each substrate with the optimized parameters and number of layers. According to our measurements, the tags on different paper substrates showed peak read ranges of 4–6.5 meters and the tags on different cardboard substrates exhibited peak read ranges of 2–6 meters. Based on their wireless performance, these inkjet-printed paper-based passive UHF RFID tags are sufficient for many future wireless applications and comparable to tags fabricated on more traditional substrates, such as polyimide.

  12. Functional Carbon Quantum Dots: A Versatile Platform for Chemosensing and Biosensing.

    Science.gov (United States)

    Feng, Hui; Qian, Zhaosheng

    2017-11-24

    Carbon quantum dot has emerged as a new promising fluorescent nanomaterial due to its excellent optical properties, outstanding biocompatibility and accessible fabrication methods, and has shown huge application perspective in a variety of areas, especially in chemosensing and biosensing applications. In this personal account, we give a brief overview of carbon quantum dots from its origin and preparation methods, present some advance on fluorescence origin of carbon quantum dots, and focus on development of chemosensors and biosensors based on functional carbon quantum dots. Comprehensive advances on functional carbon quantum dots as a versatile platform for sensing from our group are included and summarized as well as some typical examples from the other groups. The biosensing applications of functional carbon quantum dots are highlighted from selective assays of enzyme activity to fluorescent identification of cancer cells and bacteria. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Extraction and physico-chemical characterization of a versatile biodegradable polysaccharide obtained from green algae.

    Science.gov (United States)

    Alves, Anabela; Caridade, Sofia G; Mano, João F; Sousa, Rui A; Reis, Rui L

    2010-10-13

    During the last years, considerable attention has been given to different marine organisms, like algae, as potential sources of valuable materials. The continuous demand for novel materials and technologies is high and research on the underexploited marine green algae, including its polysaccharidic part-ulvan, has increased accordingly. In this research work, a novel method for extraction of ulvan from green algae is proposed and demonstrated successfully. Different characterization techniques were employed to characterize the isolated algal polysaccharide, namely, on what concerns its thermal trace and crystallinity. Upon heating, ulvan behaves as a non-meltable polysaccharide that is thermally stable before degradation at 220°C. Ulvan is semi-crystalline in nature and possesses high hygroscopic features, as revealed in this research work. Due to its properties, ulvan can be considered, pure or modified, as a versatile biodegradable polymer for different applications, including tissue engineering and regenerative medicine. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. On Developing a Novel Versatile Framework for Heterogeneous Home Monitoring WSN networks

    Directory of Open Access Journals (Sweden)

    Ch. P. Antonopoulos

    2015-05-01

    Full Text Available The ability to deploy efficient and versatile WSN networks in the home environment is and will remain in the years to come a cornerstone objective in wireless networking. Respective services are continuously expanding requiring novel design and implementation approaches able to cover all relative present and even more importantly future requirements. This paper aims to present and convey knowledge and experience gained from such an effort in the context of home monitoring. Respective discussion covers all relative aspects and analyzes all critical challenges addressed ranging from identification and specification of the main requirements, to possible implementation approaches considered and finally the actual development undertaken. The final outcome considering the WSN home monitoring infrastructure as well as extracted knowledge and practical conclusions can be proven useful for further extending such an endeavour or even pursuing a different approach.

  15. A versatile dielectron trigger for nucleon-nucleon and nucleus-nucleus collisions

    CERN Document Server

    Schicker, R; Tsertos, H

    1998-01-01

    A novel approach for a versatile first level dielectron trigger is presented. This trigger operates in the low multiplicity environment of nucleon-nucleon reactions as well as in the high multiplicity situation of nucleus-nucleus collisions. For optimal trigger performance, time of flight conditions for the two fastest particles of the event are combined with event multiplicity requirements. The dielectron trigger efficiency is given. The event reduction factor of such a trigger approach is studied for a low, a medium and a high multiplicity environment. The impact parameter dependence of the event reduction is given. The timing properties of the trigger signal are described. The losses due to deadtime are specified. Finally, the first level trigger rate is reported.

  16. Thiolated hemicellulose as a versatile platform for one-pot click-type hydrogel synthesis.

    Science.gov (United States)

    Maleki, Laleh; Edlund, Ulrica; Albertsson, Ann-Christine

    2015-02-09

    A one-pot synthetic methodology for the thiolation of O-acetyl-galactoglucomannan (AcGGM) was developed to merge hemicellulose chemistry with "click" chemistry. This was realized by the AcGGM-mediated nucleophilic ring-opening of γ-thiobutyrolactone via the activation of the polysaccharide pendant hydroxyl groups. The incorporation of thiol functionalities onto the hemicellulose backbone was visualized by (1)H and (13)C NMR spectroscopy and was assessed by an Ellman's reagent assay of the thiol groups. The versatility of the thiolated AcGGM was elaborated and demonstrated by conducting several postmodification reactions together with hydrogel formation utilizing thiol-ene and thiol-Michael addition "click" reactions. The one-pot synthesis of thiolated AcGGM is a straightforward approach that can expand the applications of hemicelluloses derived from biomass by employing "click" chemistry.

  17. Dendrimers and Dendrons as Versatile Building Blocks for the Fabrication of Functional Hydrogels

    Directory of Open Access Journals (Sweden)

    Sadik Kaga

    2016-04-01

    Full Text Available Hydrogels have emerged as a versatile class of polymeric materials with a wide range of applications in biomedical sciences. The judicious choice of hydrogel precursors allows one to introduce the necessary attributes to these materials that dictate their performance towards intended applications. Traditionally, hydrogels were fabricated using either polymerization of monomers or through crosslinking of polymers. In recent years, dendrimers and dendrons have been employed as well-defined building blocks in these materials. The multivalent and multifunctional nature of dendritic constructs offers advantages in either formulation or the physical and chemical properties of the obtained hydrogels. This review highlights various approaches utilized for the fabrication of hydrogels using well-defined dendrimers, dendrons and their polymeric conjugates. Examples from recent literature are chosen to illustrate the wide variety of hydrogels that have been designed using dendrimer- and dendron-based building blocks for applications, such as sensing, drug delivery and tissue engineering.

  18. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

    DEFF Research Database (Denmark)

    Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin

    2015-01-01

    dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural...... mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online...... correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking...

  19. Bacterial Complications of Chickenpox in Children

    Directory of Open Access Journals (Sweden)

    O. V. Samodova

    2015-01-01

    Full Text Available We performed retrospective cohort study to identify factors associated with bacterial complications of chickenpox in children. We included 128 children with chickenpo x who were hospitalized between 2000 and 2014. Binary logistic regression was used to reveal factors associated with bacterial complications. Male gender and age 3 to 6 years were positively associated with occurrence of invasive bacterial complications. We found association between atopic dermatitis and pyoderma (noinvasive bacterial complications of chickenpox. Prescribtion of acyclovir decreased the odds of invasive bacterial complications.

  20. Levofloxacin and Tobramycin for Severe Bacterial Keratouveitis.

    Science.gov (United States)

    Accorinti, Massimo; Colao, Lorena; Gilardi, Marta; Cecere, Michela; Salotti, Alessandra; Pesci, Francesca Romana

    2016-10-01

    To report on clinical features and outcome of severe bacterial keratouveitis. Twenty patients with severe bacterial keratouveitis treated with topical tobramycin and levofloxacin and oral levofloxacin were included. Main outcome measures were ulcers location, bacterial isolates, risk factors, visual prognosis. Centrally located ulcer/abscess was present in 65% of patients. Contact lens (CL) wear was the most common risk factor (70%). Bacterial isolates were observed in 58% of patients, none resistant to tobramycin and levofloxacin. Pseudomonas aeruginosa was found in 47% of positive cases and in 64% of CL wearers. After therapy, the mean visual acuity improved significantly (p levofloxacin and oral levofloxacin are effective in the treatment of bacterial keratouveitis.

  1. Mobius Assembly: A versatile Golden-Gate framework towards universal DNA assembly.

    Directory of Open Access Journals (Sweden)

    Andreas I Andreou

    Full Text Available Synthetic biology builds upon the foundation of engineering principles, prompting innovation and improvement in biotechnology via a design-build-test-learn cycle. A community-wide standard in DNA assembly would enable bio-molecular engineering at the levels of predictivity and universality in design and construction that are comparable to other engineering fields. Golden Gate Assembly technology, with its robust capability to unidirectionally assemble numerous DNA fragments in a one-tube reaction, has the potential to deliver a universal standard framework for DNA assembly. While current Golden Gate Assembly frameworks (e.g. MoClo and Golden Braid render either high cloning capacity or vector toolkit simplicity, the technology can be made more versatile-simple, streamlined, and cost/labor-efficient, without compromising capacity. Here we report the development of a new Golden Gate Assembly framework named Mobius Assembly, which combines vector toolkit simplicity with high cloning capacity. It is based on a two-level, hierarchical approach and utilizes a low-frequency cutter to reduce domestication requirements. Mobius Assembly embraces the standard overhang designs designated by MoClo, Golden Braid, and Phytobricks and is largely compatible with already available Golden Gate part libraries. In addition, dropout cassettes encoding chromogenic proteins were implemented for cost-free visible cloning screening that color-code different cloning levels. As proofs of concept, we have successfully assembled up to 16 transcriptional units of various pigmentation genes in both operon and multigene arrangements. Taken together, Mobius Assembly delivers enhanced versatility and efficiency in DNA assembly, facilitating improved standardization and automation.

  2. Versatile dual-technology system for markerless allele replacement in Burkholderia pseudomallei.

    Science.gov (United States)

    López, Carolina M; Rholl, Drew A; Trunck, Lily A; Schweizer, Herbert P

    2009-10-01

    Burkholderia pseudomallei is the etiologic agent of melioidosis, a rare but serious tropical disease. In the United States, genetic research with this select agent bacterium is strictly regulated. Although several select agent compliant methods have been developed for allelic replacement, all of them suffer from some drawbacks, such as a need for specific host backgrounds or use of minimal media. Here we describe a versatile select agent compliant allele replacement system for B. pseudomallei based on a mobilizable vector, pEXKm5, which contains (i) a multiple cloning site within a lacZalpha gene for facile cloning of recombinant DNA fragments, (ii) a constitutively expressed gusA indicator gene for visual detection of merodiploid formation and resolution, and (iii) elements required for resolution of merodiploids using either I-SceI homing endonuclease-stimulated recombination or sacB-based counterselection. The homing endonuclease-based allele replacement system is completed by pBADSce, which contains an araC-P(BAD)-I-sceI expression cassette for arabinose-inducible I-SceI expression and a temperature-sensitive pRO1600 replicon for facile plasmid curing. Complementing these systems is the improved Deltaasd Escherichia coli mobilizer strain RHO3. This strain is susceptible to commonly used antibiotics and allows nutritional counterselection on rich media because of its diaminopimelic acid auxotrophy. The versatility of the I-SceI- and sacB-based methods afforded by pEXKm5 in conjunction with E. coli RHO3 was demonstrated by isolation of diverse deletion mutants in several clinical, environmental, and laboratory B. pseudomallei strains. Finally, sacB-based counterselection was employed to isolate a defined chromosomal fabD(Ts) allele that causes synthesis of a temperature-sensitive FabD, an essential fatty acid biosynthesis enzyme.

  3. A versatile approach to vacuum injection casting for materials research and development.

    Science.gov (United States)

    Xu, Donghua; Xu, Yifan

    2017-03-01

    Vacuum injection casting (VIC) is important for research and development (R&D) of materials that are prone to oxidation at high temperatures, particularly metals and metallic alloys (e.g., metallic glasses and high entropy alloys). VIC in R&D laboratories often involves initial melting/alloying in a prior step, transporting the sample to a dedicated vacuum chamber, re-melting the sample in a quartz tube, and finally injecting the melt with an inert gas to a dedicated mold. Here we present a new approach to laboratory VIC that requires no sample transfer (for a variety of materials), no dedicated vacuum chamber/space nor dedicated mold, and hence provides more versatility and higher efficiency and yet lowers the capital equipment cost. Our approach takes advantage of the exceptional portability, thermal and chemical stability, and thermoplastic processability of quartz glass and uses quartz tubes for all the melting, re-melting, injection casting, and molding. In addition, our approach includes oxygen gettering to remove residual oxygen for all the steps and allows for slow or fast cooling (e.g., water quenching) upon injection. This paper focuses on the design, the procedures, and the versatile features of this new approach while also demonstrating the practical implementation of this approach and computational modeling of the heat transfer and the cooling rates for two exemplary cases. The new approach is expected to bring notable expedition to sample fabrication and materials discovery, as well as wider adoption of vacuum injection casting in materials science and condensed matter physics research laboratories.

  4. A Versatile Link for High-Speed, Radiation Resistant Optical Transmission in LHC Upgrades

    Science.gov (United States)

    Xiang, A.; Gong, D.; Hou, S.; Huffman, T.; Kwan, S.; Liu, K.; Liu, T.; Prosser, A.; Soos, C.; Su, D.; Teng, P.; Troska, J.; Vasey, F.; Weidberg, T.; Ye, J.

    The Versatile Link project is developing a general purpose physical layer optical link with high bandwidth, radiation resistance and magnetic-field tolerance that meets the requirements of LHC upgrade experiments. This paper presents recent work on system specifications, front-end transceiver prototypes, passive components studies and commercial back-end transceiver evaluations. System optical power budgets are specified for single mode (1310nm) and multi-mode (850nm) links, with a target data rate of 4.8 Gbps and a transmission length of 150 meters. Noise and interference penalties are simulated using the 10GbE link model and verified by bit error ratio measurement on reference links. The power margin is particularly constrained by radiation degradation of the front-end receivers. We report the power budgets for all link variants where at least 1.8 dB safety margins are maintained. The Versatile Transceiver (VTRx) - the front-end module to be installed on-detector - is based on a commercial small form pluggable (SFP+) package, modified to optimize size and mass, assembled to host a qualified laser, PIN photodiode, custom-designed radiation tolerant laser driver and receiving amplifier. A set of VTRxs with validated components have been prototyped and compliance tested. We also present the radiation test results on front-end components and passive components. The total fluence tests for lasers and PINs have been carried out with pions and neutrons up to 4 x 1015/cm2. SEU tests have been performed on PIN photodiodes and the full receiver optical subassembly. Radiation induced absorption in a number of single mode and multi-mode fibers, at -25¡C and up to 500 kGy, have been measured and high performance candidates identified. Commercial off-of-the-shelf parts have been examined for use as back-end transceivers. Compliance tests on SFP+, 4+4 parallel optical engines and SNAP 12 transmitter/receivers have been completed.

  5. DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration.

    Science.gov (United States)

    Dryden, Michael D M; Wheeler, Aaron R

    2015-01-01

    Most electroanalytical techniques require the precise control of the potentials in an electrochemical cell using a potentiostat. Commercial potentiostats function as "black boxes," giving limited information about their circuitry and behaviour which can make development of new measurement techniques and integration with other instruments challenging. Recently, a number of lab-built potentiostats have emerged with various design goals including low manufacturing cost and field-portability, but notably lacking is an accessible potentiostat designed for general lab use, focusing on measurement quality combined with ease of use and versatility. To fill this gap, we introduce DStat (http://microfluidics.utoronto.ca/dstat), an open-source, general-purpose potentiostat for use alone or integrated with other instruments. DStat offers picoampere current measurement capabilities, a compact USB-powered design, and user-friendly cross-platform software. DStat is easy and inexpensive to build, may be modified freely, and achieves good performance at low current levels not accessible to other lab-built instruments. In head-to-head tests, DStat's voltammetric measurements are much more sensitive than those of "CheapStat" (a popular open-source potentiostat described previously), and are comparable to those of a compact commercial "black box" potentiostat. Likewise, in head-to-head tests, DStat's potentiometric precision is similar to that of a commercial pH meter. Most importantly, the versatility of DStat was demonstrated through integration with the open-source DropBot digital microfluidics platform. In sum, we propose that DStat is a valuable contribution to the "open source" movement in analytical science, which is allowing users to adapt their tools to their experiments rather than alter their experiments to be compatible with their tools.

  6. A versatile approach to vacuum injection casting for materials research and development

    Science.gov (United States)

    Xu, Donghua; Xu, Yifan

    2017-03-01

    Vacuum injection casting (VIC) is important for research and development (R&D) of materials that are prone to oxidation at high temperatures, particularly metals and metallic alloys (e.g., metallic glasses and high entropy alloys). VIC in R&D laboratories often involves initial melting/alloying in a prior step, transporting the sample to a dedicated vacuum chamber, re-melting the sample in a quartz tube, and finally injecting the melt with an inert gas to a dedicated mold. Here we present a new approach to laboratory VIC that requires no sample transfer (for a variety of materials), no dedicated vacuum chamber/space nor dedicated mold, and hence provides more versatility and higher efficiency and yet lowers the capital equipment cost. Our approach takes advantage of the exceptional portability, thermal and chemical stability, and thermoplastic processability of quartz glass and uses quartz tubes for all the melting, re-melting, injection casting, and molding. In addition, our approach includes oxygen gettering to remove residual oxygen for all the steps and allows for slow or fast cooling (e.g., water quenching) upon injection. This paper focuses on the design, the procedures, and the versatile features of this new approach while also demonstrating the practical implementation of this approach and computational modeling of the heat transfer and the cooling rates for two exemplary cases. The new approach is expected to bring notable expedition to sample fabrication and materials discovery, as well as wider adoption of vacuum injection casting in materials science and condensed matter physics research laboratories.

  7. Mobius Assembly: A versatile Golden-Gate framework towards universal DNA assembly.

    Science.gov (United States)

    Andreou, Andreas I; Nakayama, Naomi

    2018-01-01

    Synthetic biology builds upon the foundation of engineering principles, prompting innovation and improvement in biotechnology via a design-build-test-learn cycle. A community-wide standard in DNA assembly would enable bio-molecular engineering at the levels of predictivity and universality in design and construction that are comparable to other engineering fields. Golden Gate Assembly technology, with its robust capability to unidirectionally assemble numerous DNA fragments in a one-tube reaction, has the potential to deliver a universal standard framework for DNA assembly. While current Golden Gate Assembly frameworks (e.g. MoClo and Golden Braid) render either high cloning capacity or vector toolkit simplicity, the technology can be made more versatile-simple, streamlined, and cost/labor-efficient, without compromising capacity. Here we report the development of a new Golden Gate Assembly framework named Mobius Assembly, which combines vector toolkit simplicity with high cloning capacity. It is based on a two-level, hierarchical approach and utilizes a low-frequency cutter to reduce domestication requirements. Mobius Assembly embraces the standard overhang designs designated by MoClo, Golden Braid, and Phytobricks and is largely compatible with already available Golden Gate part libraries. In addition, dropout cassettes encoding chromogenic proteins were implemented for cost-free visible cloning screening that color-code different cloning levels. As proofs of concept, we have successfully assembled up to 16 transcriptional units of various pigmentation genes in both operon and multigene arrangements. Taken together, Mobius Assembly delivers enhanced versatility and efficiency in DNA assembly, facilitating improved standardization and automation.

  8. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

    Directory of Open Access Journals (Sweden)

    Eduard eGrinke

    2015-10-01

    Full Text Available Walking animals, like insects, with little neural computing can effectively perform complex behaviors. They can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a walking robot is a challenging task. In this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors in the network to generate different turning angles with short-term memory for a biomechanical walking robot. The turning information is transmitted as descending steering signals to the locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations as well as escaping from sharp corners or deadlocks. Using backbone joint control embedded in the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments.

  9. Versatile vector suite for the extracytoplasmic production and purification of heterologous His-tagged proteins in Lactococcus lactis

    NARCIS (Netherlands)

    Neef, Jolanda; Milder, Fin J.; Koedijk, Danny G. A. M.; Klaassens, Marindy; Heezius, Erik C.; van Strijp, Jos A. G.; Otto, Andreas; Becher, Doerte; van Dijl, Jan Maarten; Buist, Girbe

    2015-01-01

    Recent studies have shown that the Gram-positive bacterium Lactococcus lactis can be exploited for the expression of heterologous proteins; however, a versatile set of vectors suitable for inducible extracellular protein production and subsequent purification of the expressed proteins by immobilized

  10. A Versatile Route for the Synthesis of Single Crystalline Oxide Nanorods : Growth Behavior and Field Emission Characteristics

    NARCIS (Netherlands)

    Chen, Zhenguo; Pei, F.; Pei, Y.T.; Hosson, J.Th.M. De

    The exploration of novel synthetic methodologies that control both size and shape of functional nanostructures opens new avenues for the functional application of nanomaterials. Here we report a new and versatile approach to synthesize single crystalline oxides nanorods: thermal conversion from

  11. Versatile, Fast, and Easy One-Step Method for the Synthesis of Hydrophilic Lanthanide-Doped Nanoparticles

    NARCIS (Netherlands)

    Grana Suarez, Laura; Verboom, Willem; Sarkar, Shyam; Mahalingam, V.; Huskens, Jurriaan

    2016-01-01

    The preparation of hydrophilic lanthanide-doped nanoparticles (NPs) following a versatile one-step colloidal method at low temperature and short reaction time with different doped lanthanides, capping ligands, and fluoride sources is presented. The photoluminescence of the particles, via both

  12. A versatile UHPLC–MSMS method for simultaneous quantification of various alcohol intake related compounds in human urine and blood

    DEFF Research Database (Denmark)

    Monosik, Rastislav; Dragsted, Lars Ove

    2016-01-01

    related compounds in biological samples may help to understand dietary exposure and metabolic kinetics. The aim of this study was to develop a simple, rapid and versatile UHPLC–MSMS method able of quantifying various alcohol derived compounds or potential effect markers. The method was thoroughly...

  13. A VERSATILE, LOW TOXICITY GLYCOL METHACRYLATE EMBEDDING MEDIUM FOR USE IN BIOLOGICAL-RESEARCH, AND FOR RECOVERED BIOMATERIALS PROSTHESES

    NARCIS (Netherlands)

    GERRITS, PO; EPPINGER, B; VANGOOR, H; HOROBIN, RW

    1991-01-01

    Methods for preparing standardized glycol methacrylate (GMA) based embedding media for use in light microscopy in a rational, precise and reproducible manner are described. The application of these procedures resulted in a versatile, low toxicity GMA embedding medium. GMA embedding medium and resin

  14. Patterned growth of luminescent metal-organic framework films: a versatile electrochemically-assisted microwave deposition method.

    Science.gov (United States)

    Li, Wei-Jin; Feng, Ji-Fei; Lin, Zu-Jin; Yang, Ying-Long; Yang, Yan; Wang, Xu-Sheng; Gao, Shui-Ying; Cao, Rong

    2016-03-11

    Electrochemically-assisted microwave deposition technology, a facile method for the fabrication of luminescent metal-organic framework (LMOF) films, is presented herein. This method was further developed into a versatile method for preparing patterned LMOF films. The strategy based on this method can spatially locate microcrystals of MOFs on a surface, which provides great promise in anti-counterfeiting barcode applications.

  15. The Digital Versatile Disc as a Learning Support Medium in the Teaching and Learning of Map Work

    Science.gov (United States)

    Golightly, Aubrey

    2008-01-01

    This article describes the results of a study where the digital versatile disc (DVD) was used as a variant of Information and Communication Technology (ICT) in order to aid in the teaching and learning of map work in geography at secondary school level. A group of grade 10 learners of a previously disadvantaged school in South Africa comprised the…

  16. Branched tetraether membrane lipids: A versatile group of molecular fossils as testimony of past climate change (Outstanding Young Scientist Lecture)

    Science.gov (United States)

    Weijers, J. W. H.

    2009-04-01

    Studying fossils of any kind provides a small window into past times and could learn us why the world around us is as it is today (and might become in the near future). Like paleontologists studying bone remains and palaeobotanists studying fossil plant remains, many organic geochemists study fossil molecules to learn about geochemical cycles, evolution, ecology and climate. Branched Glycerol Dialkyl Glycerol Tetraether (GDGT) membrane lipids are an example of such molecular fossils and have been the core subject of my research. These molecules were initially detected a decade ago in near coastal marine sediments and structurally resemble isoprenoid GDGTs, a group of membrane lipids synthesised by Archaea, a Domain of life separate from Bacteria and Eukarya. With nuclear magnetic resonance techniques we showed, however, that branched GDGTs are of bacterial rather than archaeal origin and analysis of soils, peat bogs and marine surface sediments pointed to a terrestrial origin. As isoprenoid GDGTs are mainly produced by marine archaea the ratio between the two groups, the Branched vs. Isoprenoid Tetraether (BIT) index, could be used to trace the input of soil organic matter into marine sediments. In this lecture I will provide examples of applications of this BIT index in the Channel River during the last Glacial Maximum and the Congo deep sea fan over the last deglaciation. Meanwhile, it appeared that in soils the distribution of individual branched GDGTs, which differ in their content of methyl branches and cyclopentane rings, was different from place to place. Analysis of over 100 soils at different locations revealed that the distribution of the branched GDGTs is most strongly related to both soil pH and annual mean air temperature. This is explained by the fact that bacteria have to adapt the composition of their cell membrane to ambient conditions in order to keep it properly functioning. This empirical relation opened opportunities to reconstruct past annual

  17. PERMEABILITY OF BACTERIAL SPORES I.

    Science.gov (United States)

    Black, S. H.; Gerhardt, Philipp

    1961-01-01

    Black, S. H. (The University of Michigan, Ann Arbor) and Philipp Gerhardt. Permeability of bacterial spores. I. Characterization of glucose uptake. J. Bacteriol. 82:743–749. 1961.—The total uptake of glucose by masses of clean, dormant spores was measured to assess their permeability. After correction for intercellular space, packed spores of Bacillus cereus strain terminalis were found in 87 determinations to be permeated by glucose to 40% of their weight. The glucose uptake was relatively independent of environmental variables, and thus was concluded to occur principally through a process of passive diffusion. PMID:13869665

  18. Pyrosequencing of bacterial symbionts within Axinella corrugata sponges: diversity and seasonal variability.

    Directory of Open Access Journals (Sweden)

    James R White

    Full Text Available BACKGROUND: Marine sponge species are of significant interest to many scientific fields including marine ecology, conservation biology, genetics, host-microbe symbiosis and pharmacology. One of the most intriguing aspects of the sponge "holobiont" system is the unique physiology, interaction with microbes from the marine environment and the development of a complex commensal microbial community. However, intraspecific variability and temporal stability of sponge-associated bacterial symbionts remain relatively unknown. METHODOLOGY/PRINCIPAL FINDINGS: We have characterized the bacterial symbiont community biodiversity of seven different individuals of the Caribbean reef sponge Axinella corrugata, from two different Florida reef locations during variable seasons using multiplex 454 pyrosequencing of 16 S rRNA amplicons. Over 265,512 high-quality 16 S rRNA sequences were generated and analyzed. Utilizing versatile bioinformatics methods and analytical software such as the QIIME and CloVR packages, we have identified 9,444 distinct bacterial operational taxonomic units (OTUs. Approximately 65,550 rRNA sequences (24% could not be matched to bacteria at the class level, and may therefore represent novel taxa. Differentially abundant classes between seasonal Axinella communities included Gammaproteobacteria, Flavobacteria, Alphaproteobacteria, Cyanobacteria, Acidobacter and Nitrospira. Comparisons with a proximal outgroup sponge species (Amphimedon compressa, and the growing sponge symbiont literature, indicate that this study has identified approximately 330 A. corrugata-specific symbiotic OTUs, many of which are related to the sulfur-oxidizing Ectothiorhodospiraceae. This family appeared exclusively within A. corrugata, comprising >34.5% of all sequenced amplicons. Other A. corrugata symbionts such as Deltaproteobacteria, Bdellovibrio, and Thiocystis among many others are described. CONCLUSIONS/SIGNIFICANCE: Slight shifts in several bacterial taxa

  19. Periodontal diseases as bacterial infection.

    Science.gov (United States)

    Bascones-Martínez, Antonio; Figuero-Ruiz, Elena

    2004-01-01

    The periodontal disease is conformed by a group of illnesses affecting the gums and dental support structures. They are caused by certain bacteria found in the bacterial plaque. These bacteria are essential to the onset of illness; however, there are predisposing factors in both the host and the microorganisms that will have an effect on the pathogenesis of the illness. Periodontopathogenic bacterial microbiota is needed, but by itself, it is not enough to cause the illness, requiring the presence of a susceptible host. These diseases have been classified as gingivitis, when limited to the gums, and periodontitis, when they spread to deeper tissues. Classification of periodontal disease has varied over the years. The one used in this work was approved at the International Workshop for a Classification of Periodontal Diseases and Conditions, held in 1999. This study is an overview of the different periodontal disease syndromes. Later, the systematic use of antibiotic treatment consisting of amoxicillin, amoxicillin-clavulanic acid, and metronidazole as first line coadjuvant treatment of these illnesses will be reviewed.

  20. Swarming dynamics in bacterial colonies

    Science.gov (United States)

    Zhang, Hepeng; Be'Er, Avraham; Smith, Rachel; Florin, E.-L.; Swinney, Harry L.

    2009-11-01

    Swarming is a widespread phenomenon observed in both biological and non-biological systems. Large mammal herds, fish schools, and bird flocks are among the most spectacular examples. Many theoretical and numerical efforts have been made to unveil the general principles of the phenomenon, but systematic experimental studies have been very limited. We determine the characteristic velocity, length, and time scales for bacterial motion in swarming colonies of Paenibacillus dendritiformis growing on semi-solid agar substrates. The bacteria swim within a thin fluid layer, and they form long-lived jets and vortices. These coherent structures lead to anisotropy in velocity spatial correlations and to a two-step relaxation in velocity temporal correlations. The mean squared displacement of passive tracers exhibits a short-time regime with nearly ballistic transport and a diffusive long-time regime. We find that various definitions of the correlation length all lead to length scales that are, surprisingly, essentially independent of the mean bacterial speed, while the correlation time is linearly proportional to the ratio of the correlation length to the mean speed.

  1. A stable live bacterial vaccine.

    Science.gov (United States)

    Kunda, Nitesh K; Wafula, Denis; Tram, Meilinn; Wu, Terry H; Muttil, Pavan

    2016-06-01

    Formulating vaccines into a dry form enhances its thermal stability. This is critical to prevent administering damaged and ineffective vaccines, and to reduce its final cost. A number of vaccines in the market as well as those being evaluated in the clinical setting are in a dry solid state; yet none of these vaccines have achieved long-term stability at high temperatures. We used spray-drying to formulate a recombinant live attenuated Listeria monocytogenes (Lm; expressing Francisella tularensis immune protective antigen pathogenicity island protein IglC) bacterial vaccine into a thermostable dry powder using various sugars and an amino acid. Lm powder vaccine showed minimal loss in viability when stored for more than a year at ambient room temperature (∼23°C) or for 180days at 40°C. High temperature viability was achieved by maintaining an inert atmosphere in the storage container and removing oxygen free radicals that damage bacterial membranes. Further, in vitro antigenicity was confirmed by infecting a dendritic cell line with cultures derived from spray dried Lm and detection of an intracellularly expressed protective antigen. A combination of stabilizing excipients, a cost effective one-step drying process, and appropriate storage conditions could provide a viable option for producing, storing and transporting heat-sensitive vaccines, especially in regions of the world that require them the most. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A versatile electrowetting-based digital microfluidic platform for quantitative homogeneous and heterogeneous bio-assays

    Science.gov (United States)

    Vergauwe, Nicolas; Witters, Daan; Ceyssens, Frederik; Vermeir, Steven; Verbruggen, Bert; Puers, Robert; Lammertyn, Jeroen

    2011-05-01

    Electrowetting-on-dielectric (EWOD) lab-on-a-chip systems have already proven their potential within a broad range of bio-assays. Nevertheless, research on the analytical performance of those systems is limited, yet crucial for a further breakthrough in the diagnostic field. Therefore, this paper presents the intrinsic possibilities of an EWOD lab-on-a-chip as a versatile platform for homogeneous and heterogeneous bio-assays with high analytical performance. Both droplet dispensing and splitting cause variations in droplet size, thereby directly influencing the assay's performance. The extent to which they influence the performance is assessed by a theoretical sensitivity analysis, which allows the definition of a basic framework for the reduction of droplet size variability. Taking advantage of the optimized droplet manipulations, both homogeneous and heterogeneous bio-assays are implemented in the EWOD lab-on-a-chip to demonstrate the analytical capabilities and versatility of the device. A fully on-chip enzymatic assay is realized with high analytical performance. It demonstrates the promising capabilities of an EWOD lab-on-a-chip in food-related and medical applications, such as nutritional and blood analyses. Further, a magnetic bio-assay for IgE detection using superparamagnetic nanoparticles is presented whereby the nanoparticles are used as solid carriers during the bio-assay. Crucial elements are the precise manipulation of the superparamagnetic nanoparticles with respect to dispensing and separation. Although the principle of using nano-carriers is demonstrated for protein detection, it can be easily extended to a broader range of bio-related applications like DNA sensing. In heterogeneous bio-assays the chip surface is actively involved during the execution of the bio-assay. Through immobilization of specific biological compounds like DNA, proteins and cells a reactive chip surface is realized, which enhances the bio-assay performance. To demonstrate

  3. EVA: Exome Variation Analyzer, an efficient and versatile tool for filtering strategies in medical genomics

    Directory of Open Access Journals (Sweden)

    Coutant Sophie

    2012-09-01

    Full Text Available Abstract Background Whole exome sequencing (WES has become the strategy of choice to identify a coding allelic variant for a rare human monogenic disorder. This approach is a revolution in medical genetics history, impacting both fundamental research, and diagnostic methods leading to personalized medicine. A plethora of efficient algorithms has been developed to ensure the variant discovery. They generally lead to ~20,000 variations that have to be narrow down to find the potential pathogenic allelic variant(s and the affected gene(s. For this purpose, commonly adopted procedures which implicate various filtering strategies have emerged: exclusion of common variations, type of the allelics variants, pathogenicity effect prediction, modes of inheritance and multiple individuals for exome comparison. To deal with the expansion of WES in medical genomics individual laboratories, new convivial and versatile software tools have to implement these filtering steps. Non-programmer biologists have to be autonomous combining themselves different filtering criteria and conduct a personal strategy depending on their assumptions and study design. Results We describe EVA (Exome Variation Analyzer, a user-friendly web-interfaced software dedicated to the filtering strategies for medical WES. Thanks to different modules, EVA (i integrates and stores annotated exome variation data as strictly confidential to the project owner, (ii allows to combine the main filters dealing with common variations, molecular types, inheritance mode and multiple samples, (iii offers the browsing of annotated data and filtered results in various interactive tables, graphical visualizations and statistical charts, (iv and finally offers export files and cross-links to external useful databases and softwares for further prioritization of the small subset of sorted candidate variations and genes. We report a demonstrative case study that allowed to identify a new candidate gene

  4. Polypyrrole-encapsulated iron tungstate nanocomposites: a versatile platform for multimodal tumor imaging and photothermal therapy

    Science.gov (United States)

    Xiao, Zhiyin; Peng, Chen; Jiang, Xiaohong; Peng, Yuxuan; Huang, Xiaojuan; Guan, Guoqiang; Zhang, Wenlong; Liu, Xiaoming; Qin, Zongyi; Hu, Junqing

    2016-06-01

    A versatile nanoplatform of FeWO4@Polypyrrole (PPy) core/shell nanocomposites, which was facilely fabricated by first hydrothermal synthesis of FeWO4 nanoparticles and subsequent surface-coating of polypyrrole shell, was developed as an effective nanotheranostic agent of cancer. The as-prepared nanocomposites demonstrated excellent dispersion in saline, long-term colloidal storage, outstanding photo-stability and high photothermal efficiency in solution. In particular, FeWO4@PPy exhibited efficient performance for hyperthermia-killing of cancer cells under the irradiation of an 808 nm laser, accompanied with multimodal contrast capabilities for magnetic resonance imaging, X-ray computed tomography and infrared thermal imaging in vitro and in vivo. Furthermore, the nanocomposites presented impactful tumor growth inhibition and good biocompability in animal experiments. Blood circulation and biodistribution of the nanocomposites were also investigated to understand their in vivo behaviours. Our results verified the platform of FeWO4@PPy nanocomposites as a promising photothermal agent for imaging-guided cancer theranostics.A versatile nanoplatform of FeWO4@Polypyrrole (PPy) core/shell nanocomposites, which was facilely fabricated by first hydrothermal synthesis of FeWO4 nanoparticles and subsequent surface-coating of polypyrrole shell, was developed as an effective nanotheranostic agent of cancer. The as-prepared nanocomposites demonstrated excellent dispersion in saline, long-term colloidal storage, outstanding photo-stability and high photothermal efficiency in solution. In particular, FeWO4@PPy exhibited efficient performance for hyperthermia-killing of cancer cells under the irradiation of an 808 nm laser, accompanied with multimodal contrast capabilities for magnetic resonance imaging, X-ray computed tomography and infrared thermal imaging in vitro and in vivo. Furthermore, the nanocomposites presented impactful tumor growth inhibition and good biocompability in

  5. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot.

    Science.gov (United States)

    Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

    2015-01-01

    Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles

  6. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

    Science.gov (United States)

    Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

    2015-01-01

    Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles

  7. Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    A. P. F. Pires

    Full Text Available Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

  8. Small molecule control of bacterial biofilms

    OpenAIRE

    Worthington, Roberta J.; Richards, Justin J.; Melander, Christian

    2012-01-01

    Bacterial biofilms are defined as a surface attached community of bacteria embedded in a matrix of extracellular polymeric substances that they have produced. When in the biofilm state, bacteria are more resistant to antibiotics and the host immune response than are their planktonic counterparts. Biofilms are increasingly recognized as being significant in human disease, accounting for 80% of bacterial infections in the body and diseases associated with bacterial biofilms include: lung infect...

  9. Bacterial, Fungal, Parasitic, and Viral Myositis

    OpenAIRE

    Crum-Cianflone, Nancy F.

    2008-01-01

    Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyo...

  10. Drag Reduction of Bacterial Cellulose Suspensions

    Directory of Open Access Journals (Sweden)

    Satoshi Ogata

    2011-01-01

    Full Text Available Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechanical shear.

  11. Bacterial and parasitic diseases of pet fish.

    Science.gov (United States)

    Roberts, Helen E; Palmeiro, Brian; Weber, E Scott

    2009-09-01

    Bacterial and parasitic diseases are very common problems in pet fish. Diagnostic testing for bacterial and parasitic diseases is simple to do; many tests can be done on ambulatory visits. When logical treatment strategies are initiated and supported by diagnostic testing, a successful outcome is possible. Identification of the correct pathogens also allows an educational opportunity for discussions on prevention and biosecurity practices with clients and although fish are poikilothermic, there are some bacterial and parasitic pathogens that are zoonotic.

  12. Bacterial Cholangitis, Cholecystitis, or both in Dogs

    OpenAIRE

    Tamborini, A.; Jahns, H; McAllister, H; Kent, A; Harris, B; Procoli, F.; Allenspach, K.; Hall, E. J.; Day, M J; Watson, P J; O'Neill, E.J.

    2016-01-01

    Background: Bacterial cholangitis and cholecystitis are rarely reported, poorly characterized diseases in the dog. Objectives: To characterize the clinical features of these conditions. Animals: Twenty-seven client-owned dogs with bacterial cholangitis, cholecystitis, or both. Methods: Multicenter, retrospective cases series of dogs with bacterial cholangitis, cholecystitis, or both, presenting January 2000 to June 2011 to 4 Veterinary Schools in Ireland/United Kingdom. Interrogation of hospi...

  13. Low abundant soil bacteria can be metabolically versatile and fast growing.

    Science.gov (United States)

    Kurm, Viola; van der Putten, Wim H; de Boer, Wietse; Naus-Wiezer, Suzanne; Hol, W H Gera

    2017-02-01

    The abundance of species is assumed to depend on their life history traits, such as growth rate and resource specialization. However, this assumption has not been tested for bacteria. Here we investigate how abundance of soil bacteria relates to slow growth and substrate specialization (oligotrophy) vs. fast growth and substrate generalization (copiotrophy). We collected 47 saprotrophic soil bacterial isolates of differing abundances and measured their growth rate and the ability to use a variety of single carbon sources. Opposite to our expectation, there was no relationship between abundance in soil and the measured growth rate or substrate utilization profile (SUP). However, isolates with lower growth rates used fewer substrates than faster growing ones supporting the assumption that growth rate may relate to substrate specialization. Interestingly, growth rate and SUP were correlated with phylogeny, rather than with abundance in soil. Most markedly, Gammaproteobacteria on average grew significantly faster and were able to use more substrates than other bacterial classes, whereas Alphaproteobacteria were growing relatively slowly and used fewer substrates. This finding suggests that growth and substrate utilization are phylogenetically deeply conserved. We conclude that growth rate and substrate utilization of soil bacteria are not general determinants of their abundance. Future studies on explaining bacterial abundance need to determine how other factors, such as competition, predation and abiotic factors may contribute to rarity or abundance in soil bacteria. © 2016 by the Ecological Society of America.

  14. Flexible Hinges in Bacterial Chemoreceptors.

    Science.gov (United States)

    Akkaladevi, Narahari; Bunyak, Filiz; Stalla, David; White, Tommi A; Hazelbauer, Gerald L

    2018-03-01

    Transmembrane bacterial chemoreceptors are extended, rod-shaped homodimers with ligand-binding sites at one end and interaction sites for signaling complex formation and histidine kinase control at the other. There are atomic-resolution structures of chemoreceptor fragments but not of intact, membrane-inserted receptors. Electron tomography of in vivo signaling complex arrays lack distinct densities for chemoreceptor rods away from the well-ordered base plate region, implying structural heterogeneity. We used negative staining, transmission electron microscopy, and image analysis to characterize the molecular shapes of intact homodimers of the Escherichia coli aspartate receptor Tar rendered functional by insertion into nanodisc-provided E. coli lipid bilayers. Single-particle analysis plus tomography of particles in a three-dimensional matrix revealed two bend loci in the chemoreceptor cytoplasmic domain, (i) a short, two-strand gap between the membrane-proximal, four-helix-bundle HAMP (histidine kinases, adenylyl cyclases, methyl-accepting chemoreceptors, and phosphatases) domain and the membrane-distal, four-helix coiled coil and (ii) aligned glycines in the extended, four-helix coiled coil, the position of a bend noted in the previous X-ray structure of a receptor fragment. Our images showed HAMP bends from 0° to ∼13° and glycine bends from 0° to ∼20°, suggesting that the loci are flexible hinges. Variable hinge bending explains indistinct densities for receptor rods outside the base plate region in subvolume averages of chemotaxis arrays. Bending at flexible hinges was not correlated with the chemoreceptor signaling state. However, our analyses showed that chemoreceptor bending avoided what would otherwise be steric clashes between neighboring receptors that would block the formation of core signaling complexes and chemoreceptor arrays. IMPORTANCE This work provides new information about the shape of transmembrane bacterial chemoreceptors, crucial

  15. STRUCTURAL ORGANIZATION OF BACTERIAL UREASES

    Directory of Open Access Journals (Sweden)

    Lisnyak YuV

    2016-09-01

    Full Text Available This brief review concerns the basic principles of structural organization of multi-subunit bacterial ureases and formation of their quaternary structure. Urease is a nickel-containing enzyme (urea amidohydrolase, ЕС 3.5.1.5 that catalyses the hydrolysis of urea to get ammonia and carbamate which then decomposes with water to get ammonia and carbon dioxide. Urease is produced by bacteria, fungi, yeast and plants. On the basis of similarities in amino acid sequences, ureases assumed to have a similar structure and conservative catalytic mechanism. Within past two decades bacterial ureases have gained much attention in research field as a virulence factor in human and animal infections. The first crystal structure of urease has been determined for that from Klebsiella aerogenes. The native enzyme consists of three subunits, UreA (α-chain, UreB (β-chain and UreC (γ-chain, and contains four structural domains: two in α-chain (α-domain 1 and α-domain-2, one in β- and one in γ-chain. These three chains form a T-shaped heterotrimer αβγ. Three αβγ heterotrimers form quaternary complex (αβγ3. In case of Helicobacter pilori, the analogous trimers of corresponding dimeric subunits (αβ3 form tetrameric structure ((αβ34 in which four trimers are situated at the vertexes of the regular triangle pyramid. Active center is located in α-domain 1 and contains two atoms of nickel coordinated by residues His134, His136, carboxylated Lys217, His 246, His272 and Asp360, as well as residues involved in binding (His219 and catalysis (His320. Active site is capped by a flap that controls substrate ingress to and product egress from the dinickel center. Urease requires accessory proteins (UreD, UreF, UreG and UreE for the correct assembly of their Ni-containing metallocenters. The accessory proteins UreD, UreF, and UreG sequentially bind to the apoprotein (UreABC3 to finally form (UreABC-UreDFG3 activation complex. UreE metallochaperone delivers

  16. Commercial Gold Nanoparticles on Untreated Aluminum Foil: Versatile, Sensitive, and Cost-Effective SERS Substrate

    Directory of Open Access Journals (Sweden)

    Kristina Gudun

    2017-01-01

    Full Text Available We introduce low-cost, tunable, hybrid SERS substrate of commercial gold nanoparticles on untreated aluminum foil (AuNPs@AlF. Two or three AuNP centrifugation/resuspension cycles are proven to be critical in the assay preparation. The limits of detection (LODs for 4-nitrobenzenethiol (NBT and crystal violet (CV on this substrate are about 0.12 nM and 0.19 nM, respectively, while maximum analytical SERS enhancement factors (AEFs are about 107. In comparative assays LODs for CV measured on AuNPs@Au film and AuNPs@glass are about 0.35 nM and 2 nM, respectively. The LOD for melamine detected on AuNPs@ Al foil is 27 ppb with 3 orders of magnitude for linear response range. Overall, AuNPs@AlF demonstrated competitive performance in comparison with AuNPs@ Au film substrate in SERS detection of CV, NBT, and melamine. To check the versatility of the AuNPs@AlF substrate we also detected KNO3 with LODs of 0.7 mM and SERS EF around 2 × 103, which is on the same order with SERS EF reported for this compound in the literature.

  17. Fluorescence exclusion: A simple versatile technique to calculate cell volumes and local heights (Conference Presentation)

    Science.gov (United States)

    Thouvenin, Olivier; Fink, Mathias; Boccara, A. Claude

    2017-02-01

    Understanding volume regulation during mitosis is technically challenging. Indeed, a very sensitive non invasive imaging over time scales ranging from seconds to hours and over large fields is required. Therefore, Quantitative Phase Imaging (QPI) would be a perfect tool for such a project. However, because of asymmetric protein segregation during mitosis, an efficient separation of the refractive index and the height in the phase signal is required. Even though many strategies to make such a separation have been developed, they usually are difficult to implement, have poor sensitivity, or cannot be performed in living cells, or in a single shot. In this paper, we will discuss the use of a new technique called fluorescence exclusion to perform volume measurements. By coupling such technique with a simultaneous phase measurement, we were also able to recover the refractive index inside the cells. Fluorescence exclusion is a versatile and powerful technique that allows the volume measurement of many types of cells. A fluorescent dye, which cannot penetrate inside the cells, is mixed with the external medium in a confined environment. Therefore, the fluorescent signal depends on the inverse of the object's height. We could demonstrate both experimentally and theoretically that fluorescence exclusion can accurately measure cell volumes, even for cells much higher than the depth of focus of the objective. A local accurate height and RI measurement can also be obtained for smaller cells. We will also discuss the way to optimize the confinement of the observation chamber, either mechanically or optically.

  18. Distance-dependent magnetic resonance tuning as a versatile MRI sensing platform for biological targets

    Science.gov (United States)

    Choi, Jin-Sil; Kim, Soojin; Yoo, Dongwon; Shin, Tae-Hyun; Kim, Hoyoung; Gomes, Muller D.; Kim, Sun Hee; Pines, Alexander; Cheon, Jinwoo

    2017-05-01

    Nanoscale distance-dependent phenomena, such as Förster resonance energy transfer, are important interactions for use in sensing and imaging, but their versatility for bioimaging can be limited by undesirable photon interactions with the surrounding biological matrix, especially in in vivo systems. Here, we report a new type of magnetism-based nanoscale distance-dependent phenomenon that can quantitatively and reversibly sense and image intra-/intermolecular interactions of biologically important targets. We introduce distance-dependent magnetic resonance tuning (MRET), which occurs between a paramagnetic `enhancer' and a superparamagnetic `quencher', where the T1 magnetic resonance imaging (MRI) signal is tuned ON or OFF depending on the separation distance between the quencher and the enhancer. With MRET, we demonstrate the principle of an MRI-based ruler for nanometre-scale distance measurement and the successful detection of both molecular interactions (for example, cleavage, binding, folding and unfolding) and biological targets in in vitro and in vivo systems. MRET can serve as a novel sensing principle to augment the exploration of a wide range of biological systems.

  19. A Versatile Multilayer Polarimeter for the Soft X-Ray Region

    Science.gov (United States)

    Wagner, U. H.; Wang, H.; Dhesi, S. S.; Sawhney, K. J. S.; MacDonald, M. A.; Poole, I. B.; Quinn, F. M.

    2010-06-01

    As modern undulators can generate light with arbitrary polarization states, experiments exploiting this feature in the range of soft x-rays have become increasingly widespread. For the success of these experiments characterising the polarization at the sample position is vital. Therefore a versatile, multi-purpose, UHV compatible, multilayer polarimeter has been designed and developed for measuring the Stokes vector of a soft x-ray beam. This high-precision, ultra high vacuum compatible instrument is supported by a Hexapod to simplify its alignment. Furthermore, the instrument has its own independent control system and has been designed for portability so that it can be moved with relative ease between different synchrotron facilities. The polarization analysis requires the rotation of a phase retarder and a polarization analyser, both about a common axis of the photon beam. The polarimeter employs reflection / transmission multilayers as phase retarders / analysers. Several sets of multilayers are installed inside the UHV chamber so that they may be exchanged in-situ without breaking the vacuum. The polarimeter doubles-up as a reflectometer / ellipsometer that enable determination of the polarization properties of optical elements including multilayers with very small surface roughness and several hundred bi-layers. The design details of the polarimeter and the results of first experiments to characterise the polarization of a beamline will be presented.

  20. A direct and versatile assay measuring membrane penetration of adenovirus in single cells.

    Science.gov (United States)

    Suomalainen, Maarit; Luisoni, Stefania; Boucke, Karin; Bianchi, Sarah; Engel, Daniel A; Greber, Urs F

    2013-11-01

    Endocytosis is the most prevalent entry port for viruses into cells, but viruses must escape from the lumen of endosomes to ensure that viral genomes reach a site for replication and progeny formation. Endosomal escape also helps viruses bypass endolysosomal degradation and presentation to certain Toll-like intrinsic immunity receptors. The mechanisms for cytosolic delivery of nonenveloped viruses or nucleocapsids from enveloped viruses are poorly understood, in part because no quantitative assays are readily available which directly measure the penetration of viruses into the cytosol. Following uptake by clathrin-mediated endocytosis or macropinocytosis, the nonenveloped adenoviruses penetrate from endosomes to the cytosol, and they traffic with cellular motors on microtubules to the nucleus for replication. In this report, we present a novel single-cell imaging assay which quantitatively measures individual cytosolic viruses and distinguishes them from endosomal viruses or viruses at the plasma membrane. Using this assay, we showed that the penetration of human adenoviruses of the species C and B occurs rapidly after virus uptake. Efficient penetration does not require acidic pH in endosomes. This assay is versatile and can be adapted to other adenoviruses and members of other nonenveloped and enveloped virus families.

  1. Paradigm Shift for Preparing Versatile M2+-Free Gels from Unmodified Sodium Alginate.

    Science.gov (United States)

    Pérez-Madrigal, Maria M; Torras, Joan; Casanovas, Jordi; Häring, Marleen; Alemán, Carlos; Díaz, David Díaz

    2017-09-11

    This manuscript describes a new route to prepare rapidly Ca2+-free hydrogels from unmodified sodium alginate by simply mixing with small organic molecules such as poly(carboxylic acid) compounds as cross-linker agents instead of classical divalent metal salts such as CaCl2. Dimethyl sulfoxide (DMSO) was also found to induce the rapid gelation of aqueous alginate solutions. The gelation process takes place at room temperature, and depending on the composition, gels with good thermal (90-100 °C) and mechanical properties compared to classical metal-containing analogs are obtained. DMSO-based gels showed remarkable self-supporting and thixotropic properties, which can be tuned by the biopolymer concentration. Furthermore, oxalic acid-based gels show superior elasticity than HCl, CaCl2 and DMSO-based gels. The possibility to prepare monoliths, beads, and films of these gels provide them with significant versatility. In particular, films made of alginate and oxalic acid show good potential as synergistic anticancer drug delivery carrier. Computational studies using both quantum mechanical and classical force-field methodologies reveal that hydrogen bonding networks between water and DMSO molecules located close to the alginate chains are responsible for the stability of DMSO-based gels. In contrast, the cohesion of oxalic acid-based gels is a consequence of the coexistence of multiple ionic associations involving oxalate, alginate, and Na+ counterions, which stabilize the system and keep all the interacting species grouped.

  2. The Vibe: A Versatile Vision-to-Audition Sensory Substitution Device

    Directory of Open Access Journals (Sweden)

    Sylvain Hanneton

    2010-01-01

    Full Text Available We describe a sensory substitution scheme that converts a video stream into an audio stream in real-time. It was initially developed as a research tool for studying human ability to learn new ways of perceiving the world: the Vibe can give us the ability to learn a kind of ‘vision’ by audition. It converts a video stream into a continuous stereophonic audio signal that conveys information coded from the video stream. The conversion from the video stream to the audio stream uses a kind of retina with receptive fields. Each receptive field controls a sound source and the user listens to a sound that is a mixture of all these sound sources. Compared to other existing vision-to-audition sensory substitution devices, the Vibe is highly versatile in particular because it uses a set of configurable units working in parallel. In order to demonstrate the validity and interest of this method of vision to audition conversion, we give the results of an experiment involving a pointing task to targets memorised through visual perception or through their auditory conversion by the Vibe. This article is also an opportunity to precisely draw the general specifications of this scheme in order to prepare its implementation on an autonomous/mobile hardware.

  3. A versatile method for cell-specific profiling of translated mRNAs in Drosophila.

    Directory of Open Access Journals (Sweden)

    Amanda Thomas

    Full Text Available In Drosophila melanogaster few methods exist to perform rapid cell-type or tissue-specific expression profiling. A translating ribosome affinity purification (TRAP method to profile actively translated mRNAs has been developed for use in a number of multicellular organisms although it has only been implemented to examine limited sets of cell- or tissue-types in these organisms. We have adapted the TRAP method for use in the versatile GAL4/UAS system of Drosophila allowing profiling of almost any tissue/cell-type with a single genetic cross. We created transgenic strains expressing a GFP-tagged ribosomal protein, RpL10A, under the control of the UAS promoter to perform cell-type specific translatome profiling. The GFP::RpL10A fusion protein incorporates efficiently into ribosomes and polysomes. Polysome affinity purification strongly enriches mRNAs from expected genes in the targeted tissues with sufficient sensitivity to analyze expression in small cell populations. This method can be used to determine the unique translatome profiles in different cell-types under varied physiological, pharmacological and pathological conditions.

  4. Tattoo-Paper Transfer as a Versatile Platform for All-Printed Organic Edible Electronics.

    Science.gov (United States)

    Bonacchini, Giorgio E; Bossio, Caterina; Greco, Francesco; Mattoli, Virgilio; Kim, Yun-Hi; Lanzani, Guglielmo; Caironi, Mario

    2018-02-20

    The use of natural or bioinspired materials to develop edible electronic devices is a potentially disruptive technology that can boost point-of-care testing. The technology exploits devices that can be safely ingested, along with pills or even food, and operated from within the gastrointestinal tract. Ingestible electronics can potentially target a significant number of biomedical applications, both as therapeutic and diagnostic tool, and this technology may also impact the food industry, by providing ingestible or food-compatible electronic tags that can "smart" track goods and monitor their quality along the distribution chain. Temporary tattoo-paper is hereby proposed as a simple and versatile platform for the integration of electronics onto food and pharmaceutical capsules. In particular, the fabrication of all-printed organic field-effect transistors on untreated commercial tattoo-paper, and their subsequent transfer and operation on edible substrates with a complex nonplanar geometry is demonstrated. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Delignification of eucalypt kraft pulp with manganese-substituted polyoxometalate assisted by fungal versatile peroxidase.

    Science.gov (United States)

    Marques, Gisela; Gamelas, José A F; Ruiz-Dueñas, Francisco J; del Rio, José C; Evtuguin, Dmitry V; Martínez, Angel T; Gutiérrez, Ana

    2010-08-01

    Oxidation of the manganese-substituted polyoxometalate [SiW(11)Mn(II)(H(2)O)O(39)](6-) (SiW(11)Mn(II)) to [SiW(11)Mn(III)(H(2)O)O(39)](5-) (SiW(11)Mn(III)), one of the most selective polyoxometalates for the kraft pulp delignification, by versatile peroxidase (VP) was studied. First, SiW(11)Mn(II) was demonstrated to be quickly oxidized by VP at room temperature in the presence of H(2)O(2) (K(m)=6.4+/-0.7 mM and k(cat)=47+/-2s(-1)). Second, the filtrate from eucalypt pulp delignification containing reduced polyoxometalate was treated with VP/H(2)O(2), and 95-100% reoxidation was attained. In this way, it was possible to reuse the liquor from a first SiW(11)Mn(III) stage for further delignification, in a sequence constituted by two polyoxometalate stages, and a short intermediate step consisting of the addition of VP/H(2)O(2) to the filtrate for SiW(11)Mn(II) reoxidation. When the first ClO(2) stage of a conventional bleaching sequence was substituted by the two-stage delignification with polyoxometalate (assisted by VP) a 50% saving in ClO(2) was obtained for similar mechanical strength of the final pulp. (c) 2010 Elsevier Ltd. All rights reserved.

  6. Towards Versatile and Sustainable Hydrogen Production through Electrocatalytic Water Splitting: Electrolyte Engineering.

    Science.gov (United States)

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2017-04-10

    Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. Electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible, and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances under which the water splitting reaction is conducted, the required solution conditions, such as the identity and molarity of ions, may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate the development of efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), affect electrode stability, and/or indirectly impact the performance by influencing the concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  7. ReagentTF: a rapid and versatile optical clearing method for biological imaging(Conference Presentation)

    Science.gov (United States)

    Yu, Tingting; Zhu, Jingtan; Li, Yusha; Qi, Yisong; Xu, Jianyi; Gong, Hui; Luo, Qingming; Zhu, Dan

    2017-02-01

    The emergence of various optical clearing methods provides a great potential for imaging deep inside tissues by combining with multiple-labelling and microscopic imaging techniques. They were generally developed for specific imaging demand thus presented some non-negligible limitations such as long incubation time, tissue deformation, fluorescence quenching, incompatibility with immunostaining or lipophilic tracers. In this study, we developed a rapid and versatile clearing method, termed ReagentTF, for deep imaging of various fluorescent samples. This method can not only efficiently clear embryos, neonatal whole-brains and adult thick brain sections by simple immersion in aqueous mixtures with minimal volume change, but also can preserve fluorescence of various fluorescent proteins and simultaneously be compatible with immunostaining and lipophilic neuronal dyes. We demonstrate the effectiveness of this method in reconstructing the cell distributions of mouse hippocampus, visualizing the neural projection from CA1 (Cornu Ammonis 1) to HDB (nucleus of the horizontal limb of the diagonal band), and observing the growth of forelimb plexus in whole-mount embryos. These results suggest that ReagentTF is useful for large-volume imaging and will be an option for the deep imaging of biological tissues.

  8. A Versatile and Reproducible Multi-Frequency Electrical Impedance Tomography System

    Directory of Open Access Journals (Sweden)

    James Avery

    2017-01-01

    Full Text Available A highly versatile Electrical Impedance Tomography (EIT system, nicknamed the ScouseTom, has been developed. The system allows control over current amplitude, frequency, number of electrodes, injection protocol and data processing. Current is injected using a Keithley 6221 current source, and voltages are recorded with a 24-bit EEG system with minimum bandwidth of 3.2 kHz. Custom PCBs interface with a PC to control the measurement process, electrode addressing and triggering of external stimuli. The performance of the system was characterised using resistor phantoms to represent human scalp recordings, with an SNR of 77.5 dB, stable across a four hour recording and 20 Hz to 20 kHz. In studies of both haeomorrhage using scalp electrodes, and evoked activity using epicortical electrode mats in rats, it was possible to reconstruct images matching established literature at known areas of onset. Data collected using scalp electrode in humans matched known tissue impedance spectra and was stable over frequency. The experimental procedure is software controlled and is readily adaptable to new paradigms. Where possible, commercial or open-source components were used, to minimise the complexity in reproduction. The hardware designs and software for the system have been released under an open source licence, encouraging contributions and allowing for rapid replication.

  9. Polysaccharide-free nucleic acids and proteins of Abelmoschus esculentus for versatile molecular studies.

    Science.gov (United States)

    Manoj-Kumar, A; Reddy, K N; Manjulatha, M; Blanco, L

    2012-01-01

    Abelmoschus esculentus (okra) is one of the polysaccharide rich crop plants. The polysaccharides interfere with nucleic acids and protein isolation thereby affecting the downstream molecular analysis. So, to understand the molecular systematics of okra, high quality DNA, RNA and proteins are essential. In this study we present a method for extracting genomic DNA, RNA and proteins from polysaccharide rich okra tissues. The conventional extraction procedures were integrated with purification treatments with pectinase, RNase and proteinase K, which improved the quality and quantity of DNA as well. Using SDS, additional washes with CIA and NaCl precipitation improved the RNA isolation both quantitatively and qualitatively. Finally, ammonium acetate mediated protein precipitation and re-solubilization increased the quality of total protein extracts from the okra leaves. All of the methods above not only eliminated the impurities but also improved the quality and quantity of nucleic acids and proteins. Further, we subjected these samples to versatile downstream molecular analyses such as restriction endonuclease digestion, RAPD, Southern, reverse transcription-PCR and Western analysis and were proved to be successful.

  10. 3D printed PLA-based scaffolds: a versatile tool in regenerative medicine.

    Science.gov (United States)

    Serra, Tiziano; Mateos-Timoneda, Miguel A; Planell, Josep A; Navarro, Melba

    2013-10-01

    Rapid prototyping (RP), also known as additive manufacturing (AM), has been well received and adopted in the biomedical field. The capacity of this family of techniques to fabricate customized 3D structures with complex geometries and excellent reproducibility has revolutionized implantology and regenerative medicine. In particular, nozzle-based systems allow the fabrication of high-resolution polylactic acid (PLA) structures that are of interest in regenerative medicine. These 3D structures find interesting applications in the regenerative medicine field where promising applications including biodegradable templates for tissue regeneration purposes, 3D in vitro platforms for studying cell response to different scaffolds conditions and for drug screening are considered among others. Scaffolds functionality depends not only on the fabrication technique, but also on the material used to build the 3D structure, the geometry and inner architecture of the structure, and the final surface properties. All being crucial parameters affecting scaffolds success. This Commentary emphasizes the importance of these parameters in scaffolds' fabrication and also draws the attention toward the versatility of these PLA scaffolds as a potential tool in regenerative medicine and other medical fields.

  11. Microscopic characterization of particle size and shape: an inexpensive and versatile method.

    Science.gov (United States)

    Houghton, M E; Amidon, G E

    1992-07-01

    A variety of methods exists for measuring individual particle dimensions as a means of characterizing particle size, size distribution, and shape. The equipment described in this report belongs to the class of semiautomatic non-TV-interfaced analyzers. Unlike many existing image analysis systems, three-dimensional form measurements and texture data for the calculation of particle size and shape parameters can be determined easily and directly from each particle profile using this system. Essentially all data are collected directly from the particle and recorded by the computer with no intermediate steps. Much of the system consists of general-purpose and relatively inexpensive, commercially available hardware and software. Using this method, particle size, size distribution, and qualitative or quantitative shape information can easily and rapidly be obtained simultaneously. Particle length and width characterization, for example, can take less than 15 min. The equipment is versatile and flexible in measurements and calculations. The size and shape parameters to be measured are determined by the researcher and not the instrument. The ease with which this information can be obtained from small samples early in the development process makes it a valuable tool for the formulator.

  12. Versatile tissue lasers based on high-Q Fabry-Pérot microcavities.

    Science.gov (United States)

    Chen, Yu-Cheng; Chen, Qiushu; Zhang, Tingting; Wang, Wenjie; Fan, Xudong

    2017-01-31

    Biolasers are an emerging technology for next generation biochemical detection and clinical applications. Progress has recently been made to achieve lasing from biomolecules and single living cells. Tissues, which consist of cells embedded in an extracellular matrix, mimic more closely the actual complex biological environment in a living body and therefore are of more practical significance. Here, we developed a highly versatile tissue laser platform, in which tissues stained with fluorophores are sandwiched in a high-Q Fabry-Pérot microcavity. Distinct lasing emissions from muscle and adipose tissues stained respectively with fluorescein isothiocyanate (FITC) and boron-dipyrromethene (BODIPY), and hybrid muscle/adipose tissue with dual staining were achieved with a threshold of only ∼10 μJ mm-2. Additionally, we investigated how the tissue structure/geometry, tissue thickness, and staining dye concentration affect the tissue laser. Lasing emission from FITC conjugates (FITC-phalloidin) that specifically target F-actin in muscle tissues was also realized. It is further found that, despite the large fluorescence spectral overlap between FITC and BODIPY in tissues, their lasing emissions could be clearly distinguished and controlled due to their narrow lasing bands and different lasing thresholds, thus enabling highly multiplexed detection. Our tissue laser platform can be broadly applicable to various types of tissues/diseases. It provides a new tool for a wide range of biological and biomedical applications, such as diagnostics/screening of tissues and identification/monitoring of biological transformations in tissue engineering.

  13. A versatile embedded boundary adaptive mesh method for compressible flow in complex geometry

    KAUST Repository

    Almarouf, Mohamad Abdulilah Alhusain Alali

    2017-02-25

    We present an embedded ghost-fluid method for numerical solutions of the compressible Navier Stokes (CNS) equations in arbitrary complex domains. A PDE multidimensional extrapolation approach is used to reconstruct the solution in the ghost-fluid regions and imposing boundary conditions on the fluid-solid interface, coupled with a multi-dimensional algebraic interpolation for freshly cleared cells. The CNS equations are numerically solved by the second order multidimensional upwind method. Block-structured adaptive mesh refinement, implemented with the Chombo framework, is utilized to reduce the computational cost while keeping high resolution mesh around the embedded boundary and regions of high gradient solutions. The versatility of the method is demonstrated via several numerical examples, in both static and moving geometry, ranging from low Mach number nearly incompressible flows to supersonic flows. Our simulation results are extensively verified against other numerical results and validated against available experimental results where applicable. The significance and advantages of our implementation, which revolve around balancing between the solution accuracy and implementation difficulties, are briefly discussed as well.

  14. Versatile Organic Chemistry on Vanadium-Based Multi-Electron Reservoirs.

    Science.gov (United States)

    Nachtigall, Olaf; Spandl, Johann

    2018-01-04

    We report the synthesis, post-functionalization, and redox behavior of two organically functionalized aggregates, [V 6 O 7 (OMe) 9 {(OCH 2 ) 3 C-CH 2 N 3 }] and [V 6 O 7 (OMe) 9 {(OCH 2 ) 3 C-NH 2 }]. All twelve μ 2 -oxo groups on the edges of the Lindqvist-type {V 6 O 19 } core were replaced by alkoxo ligands. The absence of a negative charge and the closed organic shell make these neutral mixed-valence compounds very stable towards hydrolysis and well soluble in almost all common organic solvents. These are important advantages over classical POMs. By post-functionalization through copper(I)-catalyzed Huisgen cycloaddition or imine formation, various organic moieties could be introduced. Even a well-soluble trimer composed of three hexanuclear vanadium units connected through an aromatic triimino core was synthesized and studied. The diverse redox behavior, the versatile reactivity, the good stability, and the excellent solubility make our vanadium compounds highly interesting for applications as building blocks in macromolecular chemistry as well as redox labels in biochemistry. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Aeroelastic analysis of versatile thermal insulation (VTI) panels with pinched boundary conditions

    Science.gov (United States)

    Carrera, Erasmo; Zappino, Enrico; Patočka, Karel; Komarek, Martin; Ferrarese, Adriano; Montabone, Mauro; Kotzias, Bernhard; Huermann, Brian; Schwane, Richard

    2014-03-01

    Launch vehicle design and analysis is a crucial problem in space engineering. The large range of external conditions and the complexity of space vehicles make the solution of the problem really challenging. The problem considered in the present work deals with the versatile thermal insulation (VTI) panel. This thermal protection system is designed to reduce heat fluxes on the LH2 tank during the long coasting phases. Because of the unconventional boundary conditions and the large-scale geometry of the panel, the aeroelastic behaviour of VTI is investigated in the present work. Known available results from literature related to similar problem, are reviewed by considering the effect of various Mach regimes, including boundary layer thickness effects, in-plane mechanical and thermal loads, non-linear effects and amplitude of limit cycle oscillations. A dedicated finite element model is developed for the supersonic regime. The models used for coupling the orthotropic layered structural model with Piston Theory aerodynamic models allow the calculations of flutter conditions in case of curved panels supported in a discrete number of points. An advanced computational aeroelasticity tool is developed using various dedicated commercial softwares (CFX, ZAERO, EDGE). A wind tunnel test campaign is carried out to assess the computational tool in the analysis of this type of problem.

  16. Versatile soliton emission from a WS2 mode-locked fiber laser

    Science.gov (United States)

    Guo, Bo; Li, Shi; Fan, Ya-xian; Wang, Pengfei

    2018-01-01

    Recently, few-layer tungsten disulfide (WS2), as a shining 2D material, has been discovered to possess both the saturable absorption ability and large nonlinear refractive index. Here, we demonstrate versatile soliton pulses in a passively mode-locked fiber laser with a WS2-deposited microfiber. The few-layer WS2 is prepared by the liquid-phase exfoliation method and transferred onto a microfiber by the optical deposition method. Study found, the WS2-deposited microfiber can operate simultaneously as a mode-locker and a high-nonlinear device. In experiment, by further inserting the WS2 device into the fiber laser, besides the dual-wavelength soliton, noise-like soliton pulse, conventional soliton and its harmonic form are obtained by properly adjusting the pump strength and the polarization states. For the dual-wavelength soliton pulses and noise-like pulse, the maximum output power of 14.2 mW and pulse energy of 4.74 nJ is obtained, respectively. In addition, we also achieve the maximum harmonic number (135) of conventional soliton, corresponding to a repetition rate of ∼ 497 . 5 MHz. Our study shows clearly that WS2-deposited microfiber can be as a high-nonlinear photonic device for studying a plenty of nonlinear soliton phenomena.

  17. A high-power versatile wireless power transfer for biomedical implants.

    Science.gov (United States)

    Jiang, Hao; Zhang, Jun Min; Liou, Shy Shenq; Fechter, Richard; Hirose, Shinjiro; Harrison, Michael; Roy, Shuvo

    2010-01-01

    Implantable biomedical actuators are highly desired in modern medicine. However, how to power up these biomedical implants remains a challenge since most of them need more than several hundreds mW of power. The air-core based radio-frequency transformer (two face-to-face inductive coils) has been the only non-toxic and non-invasive power source for implants for the last three decades [1]. For various technical constraints, the maximum delivered power is limited by this approach. The highest delivered power reported is 275 mW over 1 cm distance [2]. Also, the delivered power is highly vulnerable to the coils' geometrical arrangement and the electrical property of the medium around them. In this paper, a novel rotating-magnets based wireless power transfer that can deliver ∼10 W over 1 cm is demonstrated. The delivered power is significantly higher than the existing start-of-art. Further, the new method is versatile since there is no need to have the impedance matching networks that are highly susceptible to the operating frequency, the coil arrangement and the environment.

  18. SPRYSEC effectors: a versatile protein-binding platform to disrupt plant innate immunity

    Directory of Open Access Journals (Sweden)

    Amalia Diaz-Granados

    2016-10-01

    Full Text Available Persistent infections by sedentary plant-parasitic nematodes are a major threat to important food crops all over the world. These round worms manipulate host plant cell morphology and physiology to establish sophisticated feeding structures. Key modifications to plant cells during their transition into feeding structures are largely attributed to the activity of effectors secreted by the nematodes. The SPRYSEC effectors were initially identified in the potato cyst nematodes Globodera rostochiensis and G. pallida, and are characterized by a single SPRY domain, a non-catalytic domain present in modular proteins with different functions. The SPRY domain is wide-spread among eukaryotes and thought to be involved in mediating protein-protein interactions. Thus far, the SPRY domain is only reported as a functional domain in effectors of plant-parasitic nematodes, but not of other plant pathogens. SPRYSEC effectors have been implicated in both suppression and activation of plant immunity, but other possible roles in nematode virulence remain undefined. Here, we review the latest reports on the structure, function, and sequence diversity of SPRYSEC effectors, which provide support for a model featuring these effectors as a versatile protein-binding platform for the nematodes to target a wide range of host proteins during parasitism.

  19. Microbial electrolysis cells turning to be versatile technology: recent advances and future challenges.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2014-06-01

    Microbial electrolysis cells (MECs) are an electricity-mediated microbial bioelectrochemical technology, which is originally developed for high-efficiency biological hydrogen production from waste streams. Compared to traditional biological technologies, MECs can overcome thermodynamic limitations and achieve high-yield hydrogen production from wide range of organic matters at relatively mild conditions. This approach greatly reduces the electric energy cost for hydrogen production in contrast to direct water electrolysis. In addition to hydrogen production, MECs may also support several energetically unfavorable biological/chemical reactions. This unique advantage of MECs has led to several alternative applications such as chemicals synthesis, recalcitrant pollutants removal, resources recovery, bioelectrochemical research platform and biosensors, which have greatly broaden the application scopes of MECs. MECs are becoming a versatile platform technology and offer a new solution for emerging environmental issues related to waste streams treatment and energy and resource recovery. Different from previous reviews that mainly focus on hydrogen production, this paper provides an up-to-date review of all the new applications of MECs and their resulting performance, current challenges and prospects of future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Versatile high resolution oligosaccharide microarrays for plant glycobiology and cell wall research.

    Science.gov (United States)

    Pedersen, Henriette L; Fangel, Jonatan U; McCleary, Barry; Ruzanski, Christian; Rydahl, Maja G; Ralet, Marie-Christine; Farkas, Vladimir; von Schantz, Laura; Marcus, Susan E; Andersen, Mathias C F; Field, Rob; Ohlin, Mats; Knox, J Paul; Clausen, Mads H; Willats, William G T

    2012-11-16

    Microarrays are powerful tools for high throughput analysis, and hundreds or thousands of molecular interactions can be assessed simultaneously using very small amounts of analytes. Nucleotide microarrays are well established in plant research, but carbohydrate microarrays are much less established, and one reason for this is a lack of suitable glycans with which to populate arrays. Polysaccharide microarrays are relatively easy to produce because of the ease of immobilizing large polymers noncovalently onto a variety of microarray surfaces, but they lack analytical resolution because polysaccharides often contain multiple distinct carbohydrate substructures. Microarrays of defined oligosaccharides potentially overcome this problem but are harder to produce because oligosaccharides usually require coupling prior to immobilization. We have assembled a library of well characterized plant oligosaccharides produced either by partial hydrolysis from polysaccharides or by de novo chemical synthesis. Once coupled to protein, these neoglycoconjugates are versatile reagents that can be printed as microarrays onto a variety of slide types and membranes. We show that these microarrays are suitable for the high throughput characterization of the recognition capabilities of monoclonal antibodies, carbohydrate-binding modules, and other oligosaccharide-binding proteins of biological significance and also that they have potential for the characterization of carbohydrate-active enzymes.

  1. Versatile High Resolution Oligosaccharide Microarrays for Plant Glycobiology and Cell Wall Research*

    Science.gov (United States)

    Pedersen, Henriette L.; Fangel, Jonatan U.; McCleary, Barry; Ruzanski, Christian; Rydahl, Maja G.; Ralet, Marie-Christine; Farkas, Vladimir; von Schantz, Laura; Marcus, Susan E.; Andersen, Mathias C. F.; Field, Rob; Ohlin, Mats; Knox, J. Paul; Clausen, Mads H.; Willats, William G. T.

    2012-01-01

    Microarrays are powerful tools for high throughput analysis, and hundreds or thousands of molecular interactions can be assessed simultaneously using very small amounts of analytes. Nucleotide microarrays are well established in plant research, but carbohydrate microarrays are much less established, and one reason for this is a lack of suitable glycans with which to populate arrays. Polysaccharide microarrays are relatively easy to produce because of the ease of immobilizing large polymers noncovalently onto a variety of microarray surfaces, but they lack analytical resolution because polysaccharides often contain multiple distinct carbohydrate substructures. Microarrays of defined oligosaccharides potentially overcome this problem but are harder to produce because oligosaccharides usually require coupling prior to immobilization. We have assembled a library of well characterized plant oligosaccharides produced either by partial hydrolysis from polysaccharides or by de novo chemical synthesis. Once coupled to protein, these neoglycoconjugates are versatile reagents that can be printed as microarrays onto a variety of slide types and membranes. We show that these microarrays are suitable for the high throughput characterization of the recognition capabilities of monoclonal antibodies, carbohydrate-binding modules, and other oligosaccharide-binding proteins of biological significance and also that they have potential for the characterization of carbohydrate-active enzymes. PMID:22988248

  2. A new versatile microarray-based method for high throughput screening of carbohydrate-active enzymes.

    Science.gov (United States)

    Vidal-Melgosa, Silvia; Pedersen, Henriette L; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G T

    2015-04-03

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. A New Versatile Microarray-based Method for High Throughput Screening of Carbohydrate-active Enzymes*

    Science.gov (United States)

    Vidal-Melgosa, Silvia; Pedersen, Henriette L.; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B.; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G. T.

    2015-01-01

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

  4. Polydopamine-Based Simple and Versatile Surface Modification of Polymeric Nano Drug Carriers

    Science.gov (United States)

    Park, Joonyoung; Brust, Tarsis F.; Lee, Hong Jae; Lee, Sang Cheon; Watts, Val J.; Yeo, Yoon

    2014-01-01

    The surface of a polymeric nanoparticle (NP) is often functionalized with cell-interactive ligands and/or additional polymeric layers to control NP interaction with cells and proteins. However, such modification is not always straightforward when the surface is not chemically reactive. For this reason, most NP functionalization processes employ reactive linkers or coupling agents or involve pre-functionalization of the polymer, which are complicated and inefficient. Moreover, pre-functionalized polymers can lose the ability to encapsulate and retain a drug if the added ligands change chemical properties of the polymer. To overcome this challenge, we use dopamine polymerization as a way of functionalizing NP surfaces. This method includes brief incubation of the pre-formed NPs in a weak alkaline solution of dopamine, followed by secondary incubation with desired ligands. Using this method, we have functionalized poly(lactic-co-glycolic acid) (PLGA) NPs with three representative surface modifiers: a small molecule (folate), a peptide (Arg-Gly-Asp), and a polymer [poly(carboxybetaine methacrylate)]. We confirmed that the modified NPs showed the expected cellular interactions with no cytotoxicity or residual bioactivity of dopamine. The dopamine polymerization method is a simple and versatile surface modification method, applicable to a variety of NP drug carriers irrespective of their chemical reactivity and the types of ligands. PMID:24628245

  5. Integration of inorganic nanostructures with polydopamine-derived carbon: tunable morphologies and versatile applications

    Science.gov (United States)

    Kong, Junhua; Seyed Shahabadi, Seyed Ismail; Lu, Xuehong

    2016-01-01

    Polydopamine (PDA), a mussel adhesive-inspired biomimetic polymer, has attracted tremendous attention owing to its extremely versatile adhesion properties, facile aqueous coating process, capability of self-assembly to form nanostructures, and abundant surface functional groups for secondary modification. PDA is also a fantastic carbon source because it gives nitrogen (N)-doped graphite-like carbon in high yield, and the carbonized PDA (C-PDA) thin coatings have similar properties to those of N-doped multilayered graphene, i.e., they exhibit high electrical conductivity, and good electrochemical and mechanical properties. In comparison with other carbon sources, an outstanding feature of PDA lies in its ease of integration with inorganic nanostructures and capability for easy tailoring the structure and morphology of the resultant composite nanostructures. In this article, different routes for the preparation of C-PDA-based composite nanostructures, such as carbon/metal oxide and carbon/Si hollow, mesoporous, core-shell, yolk-shell nanostructures, are introduced with typical examples. The structures, morphologies and properties of the C-PDA-based composite nanostructures are also reviewed, and their potential applications in various engineering fields, such as energy storage, solar water splitting, flexible electronics, catalysis, sensing and environmental engineering, are highlighted. Finally a future outlook for this fascinating composite-nanostructure enabler is also presented.

  6. Ratsnake: a versatile image annotation tool with application to computer-aided diagnosis.

    Science.gov (United States)

    Iakovidis, D K; Goudas, T; Smailis, C; Maglogiannis, I

    2014-01-01

    Image segmentation and annotation are key components of image-based medical computer-aided diagnosis (CAD) systems. In this paper we present Ratsnake, a publicly available generic image annotation tool providing annotation efficiency, semantic awareness, versatility, and extensibility, features that can be exploited to transform it into an effective CAD system. In order to demonstrate this unique capability, we present its novel application for the evaluation and quantification of salient objects and structures of interest in kidney biopsy images. Accurate annotation identifying and quantifying such structures in microscopy images can provide an estimation of pathogenesis in obstructive nephropathy, which is a rather common disease with severe implication in children and infants. However a tool for detecting and quantifying the disease is not yet available. A machine learning-based approach, which utilizes prior domain knowledge and textural image features, is considered for the generation of an image force field customizing the presented tool for automatic evaluation of kidney biopsy images. The experimental evaluation of the proposed application of Ratsnake demonstrates its efficiency and effectiveness and promises its wide applicability across a variety of medical imaging domains.

  7. A versatile planar QCM-based sensor design for nonlabeling biomolecule detection.

    Science.gov (United States)

    Sota, Hiroyuki; Yoshimine, Hiroshi; Whittier, Robert F; Gotoh, Masanori; Shinohara, Yasuro; Hasegawa, Yukio; Okahata, Yoshio

    2002-08-01

    Despite high theoretical sensitivity, low-cost manufacture, and compactness potentially amenable to lab-on-a-chip use, practical hurdles have stymied the application of the quartz crystal microbalance (QCM) for aqueous applications such as detection of biomolecular interactions. The chief difficulty lies in achieving a sufficiently stable resonance signal in the presence of even minute fluctuations in hydrostatic pressure. In this work, we present a novel versatile planar sensor chip design (QCM chip) for a microliter-scale on-line biosensor. By sealing the quartz resonator along its edges to a flat, solid support, we provide uniform support for the crystal face not exposed to solvent, greatly decreasing deformation of the crystal resonator under hydrostatic pressure. Furthermore, this cassette design obviates the need for direct handling when exchanging the delicate quartz crystal in the flow cell. A prototype 27-MHz sensor signal exhibited very low noise over a range of flow rates up to 100 microL/min. In contrast, signals obtained from a conventional QCM sensor employing an O-ring-based holder were less stable and deteriorated even further with increasing flow rate. Additional control designs with intermediate amounts of unsupported undersurface yielded intermediate levels of stability, consistent with the interpretation that deformation of the crystal resonator under fluctuating hydraulic pressure is the chief source of noise. As a practical demonstration of the design's high effective sensitivity, we readily detected interaction between myoglobin and surface-bound antibody.

  8. Rolling circle amplification: a versatile tool for chemical biology, materials science and medicine.

    Science.gov (United States)

    Ali, M Monsur; Li, Feng; Zhang, Zhiqing; Zhang, Kaixiang; Kang, Dong-Ku; Ankrum, James A; Le, X Chris; Zhao, Weian

    2014-05-21

    Rolling circle amplification (RCA) is an isothermal enzymatic process where a short DNA or RNA primer is amplified to form a long single stranded DNA or RNA using a circular DNA template and special DNA or RNA polymerases. The RCA product is a concatemer containing tens to hundreds of tandem repeats that are complementary to the circular template. The power, simplicity, and versatility of the DNA amplification technique have made it an attractive tool for biomedical research and nanobiotechnology. Traditionally, RCA has been used to develop sensitive diagnostic methods for a variety of targets including nucleic acids (DNA, RNA), small molecules, proteins, and cells. RCA has also attracted significant attention in the field of nanotechnology and nanobiotechnology. The RCA-produced long, single-stranded DNA with repeating units has been used as template for the periodic assembly of nanospecies. Moreover, since RCA products can be tailor-designed by manipulating the circular template, RCA has been employed to generate complex DNA nanostructures such as DNA origami, nanotubes, nanoribbons and DNA based metamaterials. These functional RCA based nanotechnologies have been utilized for biodetection, drug delivery, designing bioelectronic circuits and bioseparation. In this review, we introduce the fundamental engineering principles used to design RCA nanotechnologies, discuss recently developed RCA-based diagnostics and bioanalytical tools, and summarize the use of RCA to construct multivalent molecular scaffolds and nanostructures for applications in biology, diagnostics and therapeutics.

  9. Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

    Directory of Open Access Journals (Sweden)

    Atsushi Tamura

    2016-12-01

    Full Text Available Cyclodextrin (CD-threaded polyrotaxanes (PRXs with reactive functional groups at the terminals of the axle polymers are attractive candidates for the design of supramolecular materials. Herein, we describe a novel and simple synthetic method for end-reactive PRXs using bis(2-amino-3-phenylpropyl poly(ethylene glycol (PEG-Ph-NH2 as an axle polymer and commercially available 4-substituted benzoic acids as capping reagents. The terminal 2-amino-3-phenylpropyl groups of PEG-Ph-NH2 block the dethreading of the α-CDs after capping with 4-substituted benzoic acids. By this method, two series of azide group-terminated polyrotaxanes (benzylazide: PRX-Bn-N3, phenylazide: PRX-Ph-N3, were synthesized for functionalization via click reactions. The PRX-Bn-N3 and PRX-Ph-N3 reacted quickly and efficiently with p-(tert-butylphenylacetylene via copper-catalyzed click reactions. Additionally, the terminal azide groups of the PRX-Bn-N3 could be modified with dibenzylcyclooctyne (DBCO-conjugated fluorescent molecules via a copper-free click reaction; this fluorescently labeled PRX was utilized for intracellular fluorescence imaging. The method of synthesizing end-reactive PRXs described herein is simple and versatile for the design of diverse functional PRXs and can be applied to the fabrication of PRX-based supramolecular biomaterials.

  10. Kinetics and metabolic versatility of highly tolerant phenol degrading Alcaligenes strain TW1.

    Science.gov (United States)

    Essam, Tamer; Amin, Magdy Aly; El Tayeb, Ossama; Mattiasson, Bo; Guieysse, Benoit

    2010-01-15

    A bacterium that could completely metabolize phenol in batch culture supplied with up to 1200 mg phenol l(-1) at room temperature (25 degrees C) was isolated from the activated sludge of the industrial wastewater treatment plant of a Coke company (Cairo, Egypt). Morphological and physiological characterization showed strain TW1 was a motile, strictly aerobic, gram negative and short-rod occurring singly or in clusters. Partial 16S rRNA gene sequence analysis revealed strain TW1 belonged to the beta group of Proteobacteria, showing 100% identity to Alcaligenes SCTI. Strain TW1 aerobically grew on a number of monocyclic aromatic compounds (hydroquinone, catechol and o-cresol) as well as polycyclic aromatic compounds (pyrene, phenanthrene and naphthalene). The growth of Alcaligenes TW1 on phenol as sole carbon and energy source (25 degrees C) was well described by the Haldane kinetics model with a maximal specific growth rate of 0.58 h(-1), a half-saturation constant of 10 mg l(-1), and a substrate inhibition constant of 152-550 mg l(-1). The biomass yield coefficient ranged from 0.55 to 0.64 mg dry cell mass/mg phenol. Due to its high tolerance to phenol and high metabolic versatility, Alcaligenes sp. TW1 is considered an excellent candidate for the biotreatment of high strength phenol-laden industrial wastewaters.

  11. Ratsnake: A Versatile Image Annotation Tool with Application to Computer-Aided Diagnosis

    Directory of Open Access Journals (Sweden)

    D. K. Iakovidis

    2014-01-01

    Full Text Available Image segmentation and annotation are key components of image-based medical computer-aided diagnosis (CAD systems. In this paper we present Ratsnake, a publicly available generic image annotation tool providing annotation efficiency, semantic awareness, versatility, and extensibility, features that can be exploited to transform it into an effective CAD system. In order to demonstrate this unique capability, we present its novel application for the evaluation and quantification of salient objects and structures of interest in kidney biopsy images. Accurate annotation identifying and quantifying such structures in microscopy images can provide an estimation of pathogenesis in obstructive nephropathy, which is a rather common disease with severe implication in children and infants. However a tool for detecting and quantifying the disease is not yet available. A machine learning-based approach, which utilizes prior domain knowledge and textural image features, is considered for the generation of an image force field customizing the presented tool for automatic evaluation of kidney biopsy images. The experimental evaluation of the proposed application of Ratsnake demonstrates its efficiency and effectiveness and promises its wide applicability across a variety of medical imaging domains.

  12. Metabolic versatility of a novel N2 -fixing Alphaproteobacterium isolated from a marine oxygen minimum zone.

    Science.gov (United States)

    Martínez-Pérez, Clara; Mohr, Wiebke; Schwedt, Anne; Dürschlag, Julia; Callbeck, Cameron M; Schunck, Harald; Dekaezemacker, Julien; Buckner, Caroline R T; Lavik, Gaute; Fuchs, Bernhard M; Kuypers, Marcel M M

    2017-12-01

    The N2 -fixing (diazotrophic) community in marine ecosystems is dominated by non-cyanobacterial microorganisms. Yet, very little is known about their identity, function and ecological relevance due to a lack of cultured representatives. Here we report a novel heterotrophic diazotroph isolated from the oxygen minimum zone (OMZ) off Peru. The new species belongs to the genus Sagittula (Rhodobacteraceae, Alphaproteobacteria) and its capability to fix N2 was confirmed in laboratory experiments. Genome sequencing revealed that it is a strict heterotroph with a high versatility in substrate utilization and energy acquisition mechanisms. Pathways for sulfide oxidation and nitrite reduction to nitrous oxide are encoded in the genome and might explain the presence throughout the Peruvian OMZ. The genome further indicates that this novel organism could be in direct interaction with other microbes or particles. NanoSIMS analyses were used to compare the metabolic potential of S. castanea with single-cell activity in situ; however, N2 fixation by this diazotroph could not be detected at the isolation site. While the biogeochemical impact of S. castanea is yet to be resolved, its abundance and widespread distribution suggests that its potential to contribute to the marine N input could be significant at a larger geographical scale. This article is protected by copyright. All rights reserved. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Genomic and physiological analysis reveals versatile metabolic capacity of deep-sea Photobacterium phosphoreum ANT-2200.

    Science.gov (United States)

    Zhang, Sheng-Da; Santini, Claire-Lise; Zhang, Wei-Jia; Barbe, Valérie; Mangenot, Sophie; Guyomar, Charlotte; Garel, Marc; Chen, Hai-Tao; Li, Xue-Gong; Yin, Qun-Jian; Zhao, Yuan; Armengaud, Jean; Gaillard, Jean-Charles; Martini, Séverine; Pradel, Nathalie; Vidaud, Claude; Alberto, François; Médigue, Claudine; Tamburini, Christian; Wu, Long-Fei

    2016-05-01

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

  14. The Versatility of 980 nm Diode Laser in Dentistry: A Case Series

    Science.gov (United States)

    Derikvand, Nahid; Chinipardaz, Zahra; Ghasemi, Sara; Chiniforush, Nasim

    2016-01-01

    Introduction: Laser surgery has been considered a popular alternative over conventional modalities in dentistry during the last few years. Among different types of lasers, diode lasers have gained special attention in oral soft tissue surgery. Case Reports: Five patients were referred to a private office. After careful evaluation of medical history and oral examination, oral diagnosis and treatment plan of each patient was established as follows: (1) A 21-year-old female with ankyloglossia (tongue-tie); (2) A 65-year-old female with a poor denture fit needing vestibuloplasty and frenectomy; (3) A 10-year-old male patient with pigmented gingiva in mandible and maxilla; (4) A 14-year-old female needing exposure of maxillary right canine for bracket bonding; and (5) A 25-year-old female patient who has a gingival maxillary frenum with a nodule. The treatment plan for all the patients was laser surgery with diode laser at 980 nm, in continuous mode. Results: All the patients experienced normal healing process with no postoperative complications. Favorable outcomes of laser surgery were observed on follow-up sessions. Conclusion: Considering the versatility of the 980 nm diode laser in oral soft tissue surgeries and the advantages of laser surgery, this study suggests the use of 980 nm diode laser in this regard. PMID:28144444

  15. Versatility of Capsular Flaps in the Salvage of Exposed Breast Implants

    Directory of Open Access Journals (Sweden)

    Beniamino Brunetti, MD

    2015-03-01

    Full Text Available Summary: Breast implant exposure due to poor tissue coverage or previous irradiation represents a surgical challenge both in the reconstructive and aesthetic plastic surgery practice. In case of implant extrusion or incipient exposure, the commonly suggested strategies, such as targeted antibiotic therapy, drainage and lavage of the cavity, fistulectomy, and primary closure, may be ineffective leading the surgeon to an unwanted implant removal or to adopt more invasive flap coverage procedures. Breast implant capsule, in its physiological clinical behavior, can be considered as a new reliable source of tissue, which can be used in a wide range of clinical situations. In our hands, capsular flaps proved to be a versatile solution not only to treat breast contour deformities or inframammary fold malpositions but also to salvage exposed breast implants. In this scenario, the use of more invasive surgical techniques can be avoided or simply saved and delayed for future recurrences.(Plast Reconstr Surg Glob Open 2015;3:e340; doi:10.1097/GOX.0000000000000307; Published online 30 March 2015.

  16. Carbon nanotubes part I: preparation of a novel and versatile drug-delivery vehicle

    Science.gov (United States)

    Karimi, Mahdi; Solati, Navid; Amiri, Mohammad; Mirshekari, Hamed; Mohamed, Elmira; Taheri, Mahdiar; Hashemkhani, Mahshid; Saeidi, Ahad; Estiar, Mehrdad Asghari; Kiani, Parnian; Ghasemi, Amir; Basri, Seyed Masoud Moosavi; Aref, Amir R

    2015-01-01

    Introduction It is 23 years since carbon allotrope known as carbon nanotubes (CNT) was discovered by Iijima, who described them as “rolled graphite sheets inserted into each other”. Since then, CNTs have been studied in nanoelectronic devices. However, CNTs also possess the versatility to act as drug- and gene-delivery vehicles. Areas covered This review covers the synthesis, purification and functionalization of CNTs. Arc discharge, laser ablation and chemical vapor deposition are the principle synthesis methods. Non-covalent functionalization relies on attachment of biomolecules by coating the CNT with surfactants, synthetic polymers and biopolymers. Covalent functionalization often involves the initial introduction of carboxylic acids or amine groups, diazonium addition, 1,3-dipolar cycloaddition or reductive alkylation. The aim is to produce functional groups to attach the active cargo. Expert opinion In this review, the feasibility of CNT being used as a drug-delivery vehicle is explored. The molecular composition of CNT is extremely hydrophobic and highly aggregation-prone. Therefore, most of the efforts towards drug delivery has centered on chemical functionalization, which is usually divided in two categories; non-covalent and covalent. The biomedical applications of CNT are growing apace, and new drug-delivery technologies play a major role in these efforts. PMID:25601356

  17. Decoupled cantilever arms for highly versatile and sensitive temperature and heat flux measurements.

    Science.gov (United States)

    Burg, Brian R; Tong, Jonathan K; Hsu, Wei-Chun; Chen, Gang

    2012-10-01

    Microfabricated cantilever beams have been used in microelectromechanical systems for a variety of sensor and actuator applications. Bimorph cantilevers accurately measure temperature change and heat flux with resolutions several orders of magnitude higher than those of conventional sensors such as thermocouples, semiconductor diodes, as well as resistance and infrared thermometers. The use of traditional cantilevers, however, entails a series of important measurement limitations, because their interactions with the sample and surroundings often create parasitic deflection forces and the typical metal layer degrades the thermal sensitivity of the cantilever. The paper introduces a design to address these issues by decoupling the sample and detector section of the cantilever, along with a thermomechanical model, the fabrication, system integration, and characterization. The custom-designed bi-arm cantilever is over one order of magnitude more sensitive than current commercial cantilevers due to the significantly reduced thermal conductance of the cantilever sample arm. The rigid and immobile sample section offers measurement versatility ranging from photothermal absorption, near-field thermal radiation down to contact, conduction, and material thermal characterization measurements in nearly identical configurations.

  18. Bio-inspired polydopamine: a versatile and powerful platform for covalent synthesis of molecular sieve membranes.

    Science.gov (United States)

    Liu, Qian; Wang, Nanyi; Caro, Jürgen; Huang, Aisheng

    2013-11-27

    Inspired by the bioadhesive ability of the marine mussel, a simple, versatile, and powerful synthesis strategy was developed to prepare highly reproducible and permselective molecular sieve membranes by using polydopamine as a novel covalent linker. Attributing to the formation of strong covalent and noncovalent bonds, ZIF-8 nutrients are attracted and bound to the support surface, thus promoting the ZIF-8 nucleation and the growth of uniform, well intergrown, and phase-pure ZIF-8 molecular sieve membranes. The developed ZIF-8 membranes show high hydrogen selectivity and thermal stability. At 150 °C and 1 bar, the mixture separation factors of H2/CO2, H2/N2, H2/CH4, and H2/C3H8 are 8.9, 16.2, 31.5 and 712.6, with H2 permeances higher than 1.8 × 10(-7) mol·m(-2)·s(-1)·Pa(-1), which is promising for hydrogen separation and purification.

  19. Concept maps as versatile tools to integrate complex ideas: From kindergarten to higher and professional education

    Directory of Open Access Journals (Sweden)

    Beat A. Schwendimann

    2015-03-01

    Full Text Available Knowledge is getting increasingly more complex. Learners, from Kindergarten to higher education, require powerful tools to connect complex ideas. This paper explores the range of studies that investigated concept maps as learning, metacognitive, collaborative, and assessment tools to support integrating complex ideas. Research suggests that concept maps can be successfully implemented in a wide variety of settings, from K12 to higher and professional education. However, the effectiveness of concept maps depends on different factors, such as concept map training and choosing a suitable form of concept map to match the task and learner. Developing proficiency in concept mapping takes time and practice and should not be first introduced in higher education. Concept map training could start as early as Kindergarten and include concept map generation, interpretation, and revision. This paper concludes that, if implemented thoughtfully, concept maps can be versatile tools to support knowledge integration processes towards a deeper understanding of the relations and structures of complex ideas and facilitate life-long learning.

  20. The versatile application of cervicofacial and cervicothoracic rotation flaps in head and neck surgery

    Directory of Open Access Journals (Sweden)

    Liu Fa-yu

    2011-10-01

    Full Text Available Abstract Background The large defects resulting from head and neck tumour surgeries present a reconstructive challenge to surgeons. Although numerous methods can be used, they all have their own limitations. In this paper, we present our experience with cervicofacial and cervicothoracic rotation flaps to help expand the awareness and application of this useful system of flaps. Methods Twenty-one consecutive patients who underwent repair of a variety of defects of the head and neck with cervicofacial or cervicothoracic flaps in our hospital from 2006 to 2009 were retrospectively analysed. Statistics pertaining to the patients' clinical factors were gathered. Results Cheek neoplasms are the most common indication for cervicofacial and cervicothoracic rotation flaps, followed by parotid tumours. Among the 12 patients with medical comorbidities, the most common was hypertension. Defects ranging from 1.5 cm × 1.5 cm to 7 cm × 6 cm were reconstructed by cervicofacial flap, and defects from 3 cm × 2 cm to 16 cm × 7 cm were reconstructed by cervicothoracic flap. The two flaps also exhibited versatility in these reconstructions. When combined with the pectoralis major myocutaneous flap, the cervicothoracic flap could repair through-and-through cheek defects, and in combination with a temporalis myofacial flap, the cervicofacial flap was able to cover orbital defects. Additionally, 95% patients were satisfied with their resulting contour results. Conclusions Cervicofacial and cervicothoracic flaps provide a technically simple, reliable, safe, efficient and cosmetic means to reconstruct defects of the head and neck.

  1. Versatile Synthesis of Amino Acid Functional Polymers without Protection Group Chemistry.

    Science.gov (United States)

    Brisson, Emma R L; Xiao, Zeyun; Franks, George V; Connal, Luke A

    2017-01-09

    The copolymerization of N-isopropylacrylamide (NiPAm) with aldehyde functional monomers facilitates postpolymerization functionalization with amino acids via reductive amination, negating the need for protecting groups. In reductive amination, the imine formed from the condensation reaction between an amine and an aldehyde is reduced to an amine. In this work, we categorize amino acids into four classes based on the functionality of their side chains (acidic, polar neutral, neutral, and basic) and use their amine groups in condensation reactions with aldehyde functional polymers. The dynamic nature of the imine as well as the versatility of reductive amination to functionalize a polymer with a range of amino acids is highlighted. In this manner, amino acid functional polymers are synthesized without the use of protecting groups with high yields, demonstrating the high functional group tolerance of carbonyl condensation chemistry and the subsequent reduction of the imine. Prior to the reduction of the imine bond, transimination reactions are used to demonstrate dynamic polymers that shuffle from a glycine- to a histidine-functional polymer.

  2. Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition.

    Science.gov (United States)

    Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

    2017-05-01

    Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

  3. Polydopamine meets porous membrane: A versatile platform for facile preparation of membrane adsorbers.

    Science.gov (United States)

    Fan, Jinxin; Luo, Jianquan; Chen, Xiangrong; Wan, Yinhua

    2016-05-27

    Polydopamine, as an intermediate layer coated on PES membrane, was applied to fabricate various membrane adsorbers. Anion-exchange, hydrophobic interaction and affinity membrane adsorbers prepared by this facile method exhibited a high selectivity in fractionation of IgG (immunoglobulin)/HSA (human serum albumin) mixture. The anion-exchange membrane adsorber containing polyethylenimine (PEI) improved the HSA purity from 17.7% to 96.7%; The hydrophobic interaction membrane adsorber with Dodecyl mercaptan (DDM) as ligand obtained an IgG purity of 94.6%; Histidine attached affinity membrane chromatography achieved nearly a 100% purity of IgG. The present work indicated that the polydopamine layer not only activated membrane surface to attach various adsorptive ligands under the mild condition, but also reduced non-specific adsorption. Due to the versatile conjunction function, this facile mussel-inspired coating is also promising for the preparation of diverse membrane adsorbers. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Polydopamine-based simple and versatile surface modification of polymeric nano drug carriers.

    Science.gov (United States)

    Park, Joonyoung; Brust, Tarsis F; Lee, Hong Jae; Lee, Sang Cheon; Watts, Val J; Yeo, Yoon

    2014-04-22

    The surface of a polymeric nanoparticle (NP) is often functionalized with cell-interactive ligands and/or additional polymeric layers to control NP interaction with cells and proteins. However, such modification is not always straightforward when the surface is not chemically reactive. For this reason, most NP functionalization processes employ reactive linkers or coupling agents or involve prefunctionalization of the polymer, which are complicated and inefficient. Moreover, prefunctionalized polymers can lose the ability to encapsulate and retain a drug if the added ligands change the chemical properties of the polymer. To overcome this challenge, we use dopamine polymerization as a way of functionalizing NP surfaces. This method includes brief incubation of the preformed NPs in a weak alkaline solution of dopamine, followed by secondary incubation with desired ligands. Using this method, we have functionalized poly(lactic-co-glycolic acid) (PLGA) NPs with three representative surface modifiers: a small molecule (folate), a peptide (Arg-Gly-Asp), and a polymer [poly(carboxybetaine methacrylate)]. We confirmed that the modified NPs showed the expected cellular interactions with no cytotoxicity or residual bioactivity of dopamine. The dopamine polymerization method is a simple and versatile surface modification method, applicable to a variety of NP drug carriers irrespective of their chemical reactivity and the types of ligands.

  5. Versatile Methodology to Encapsulate Gold Nanoparticles in PLGA Nanoparticles Obtained by Nano-Emulsion Templating.

    Science.gov (United States)

    Fornaguera, Cristina; Feiner-Gracia, Natàlia; Dols-Perez, Aurora; García-Celma, Maria José; Solans, Conxita

    2017-05-01

    Gold nanoparticles have been proved useful for many biomedical applications, specifically, for their use as advanced imaging systems. However, they usually present problems related with stability and toxicity. In the present work, gold-nanoparticles have been encapsulated in polymeric nanoparticles using a novel methodology based on nano-emulsion templating. Firstly, gold nanoparticles have been transferred from water to ethyl acetate, a solvent classified as class III by the NIH guidelines (low toxic potential). Next, the formation of nano-emulsions loaded with gold nanoparticles has been performed using a low-energy, the phase inversion composition (PIC) emulsification method, followed by solvent evaporation giving rise to polymeric nanoparticles. Using this methodology, high concentrations of gold nanoparticles (>100 pM) have been encapsulated. Increasing gold nanoparticle concentration, nano-emulsion and nanoparticle sizes increase, resulting in a decrease on the stability. It is noteworthy that the designed nanoparticles did not produce cytotoxicity neither hemolysis at the required concentration. Therefore, it can be concluded that a novel and very versatile methodology has been developed for the production of polymeric nanoparticles loaded with gold nanoparticles. Graphical Abstract Schematic representation of AuNP-loaded polymeric nanoparticles preparation from nano-emulsion templating.

  6. A design study of VOR: A versatile optimal resolution chopper spectrometer for the ESS

    Directory of Open Access Journals (Sweden)

    Deen P.P.

    2015-01-01

    Full Text Available VOR, the versatile optimal resolution chopper spectrometer, is designed to probe dynamic phenomena that are currently inaccessible for inelastic neutron scattering due to flux limitations. VOR is a short instrument by the standards of the European Spallation Source (ESS, 30.2 m moderator to sample, and provides instantaneous access to a broad dynamic range, 1–120 meV within each ESS period. The short instrument length combined with the long ESS pulse width enables a quadratic flux increase, even at longer wavelengths, by relaxing energy resolution from ΔE/E = 1% up to ΔE/E = 7%. This is impossible both on a long chopper spectrometer at the ESS and with instruments at short pulsed sources. In comparison to current day chopper spectrometers, VOR can offer an order of magnitude improvement in flux for equivalent energy resolutions, ΔE/E = 1–3%. Further relaxing the energy resolution enables VOR to gain an extra order of magnitude in flux. In addition, VOR has been optimised for repetition rate multiplication (RRM and is therefore able to measure, in a single ESS period, 6–14 incident wavelengths, across a wavelength band of 9 Å with a novel chopper configuration that transmits all incident wavelengths with equivalent counting statistics. The characteristics of VOR make it a unique instrument with capabilities to access small, limited-lifetime samples and transient phenomena with inelastic neutron scattering.

  7. The Ly49 natural killer cell receptors: a versatile tool for viral self-discrimination.

    Science.gov (United States)

    Berry, Richard; Rossjohn, Jamie; Brooks, Andrew G

    2014-03-01

    The activation of murine and human natural killer (NK) cells is regulated by families of receptors including the Ly49 and Killer immunoglobulin-like receptors, respectively, both of which contain activating and inhibitory members. The archetypal role of inhibitory Ly49 receptors is to attenuate NK cell responses to normal cells that express major histocompatibility complex (MHC) class-I molecules, in essence allowing for more robust responses to infected or cancerous cells that lack MHC-I on their cell surface. However, it is now evident that Ly49 receptors have an appreciably more sophisticated array of functions. In particular, some activating Ly49 receptors can bind directly to MHC-I-like viral gene products such as m157, whereas others recognize self-MHC-I but only in the presence of viral chaperones. Although Ly49 receptor recognition is centred on the MHC-I-like fold, these NK cell receptors can also engage related ligands in unexpected ways. Herein we review the varied strategies employed by Ly49 receptors to recognize both self and viral ligands, with particular emphasis on the recently determined mode of Ly49-m157 ligation, and highlight the versatile nature of this family in the control of viral infections.

  8. A Direct and Versatile Assay Measuring Membrane Penetration of Adenovirus in Single Cells

    Science.gov (United States)

    Suomalainen, Maarit; Luisoni, Stefania; Boucke, Karin; Bianchi, Sarah; Engel, Daniel A.

    2013-01-01

    Endocytosis is the most prevalent entry port for viruses into cells, but viruses must escape from the lumen of endosomes to ensure that viral genomes reach a site for replication and progeny formation. Endosomal escape also helps viruses bypass endolysosomal degradation and presentation to certain Toll-like intrinsic immunity receptors. The mechanisms for cytosolic delivery of nonenveloped viruses or nucleocapsids from enveloped viruses are poorly understood, in part because no quantitative assays are readily available which directly measure the penetration of viruses into the cytosol. Following uptake by clathrin-mediated endocytosis or macropinocytosis, the nonenveloped adenoviruses penetrate from endosomes to the cytosol, and they traffic with cellular motors on microtubules to the nucleus for replication. In this report, we present a novel single-cell imaging assay which quantitatively measures individual cytosolic viruses and distinguishes them from endosomal viruses or viruses at the plasma membrane. Using this assay, we showed that the penetration of human adenoviruses of the species C and B occurs rapidly after virus uptake. Efficient penetration does not require acidic pH in endosomes. This assay is versatile and can be adapted to other adenoviruses and members of other nonenveloped and enveloped virus families. PMID:24027314

  9. The Versatility of 980 nm Diode Laser in Dentistry: A Case Series.

    Science.gov (United States)

    Derikvand, Nahid; Chinipardaz, Zahra; Ghasemi, Sara; Chiniforush, Nasim

    2016-01-01

    Introduction: Laser surgery has been considered a popular alternative over conventional modalities in dentistry during the last few years. Among different types of lasers, diode lasers have gained special attention in oral soft tissue surgery. Case Reports: Five patients were referred to a private office. After careful evaluation of medical history and oral examination, oral diagnosis and treatment plan of each patient was established as follows: (1) A 21-year-old female with ankyloglossia (tongue-tie); (2) A 65-year-old female with a poor denture fit needing vestibuloplasty and frenectomy; (3) A 10-year-old male patient with pigmented gingiva in mandible and maxilla; (4) A 14-year-old female needing exposure of maxillary right canine for bracket bonding; and (5) A 25-year-old female patient who has a gingival maxillary frenum with a nodule. The treatment plan for all the patients was laser surgery with diode laser at 980 nm, in continuous mode. Results: All the patients experienced normal healing process with no postoperative complications. Favorable outcomes of laser surgery were observed on follow-up sessions. Conclusion: Considering the versatility of the 980 nm diode laser in oral soft tissue surgeries and the advantages of laser surgery, this study suggests the use of 980 nm diode laser in this regard.

  10. The Spanish word tiempo: its omnipresence and conceptual, logical and lexical versatility

    Directory of Open Access Journals (Sweden)

    Karlo Budor

    2012-12-01

    Full Text Available The common Spanish word tiempo corresponds to three English terms, each of them being a lexical equivalent based on a specific notion: (1 time – physical, astronomical, philosophical reference; (2 weather – geographical, climatological, meteorological reference; (3 tense: linguistic, lexical, grammatical reference. As far as universal and metalinguistic referential distinctions are concerned, all natural languages in fact present a considerable degree of variation ranging from inexistent or very vague to complete differentiation of these terms. In order to express these three types of specific references, some languages have a single word of general usage covering all its lexical acceptations. Therefore in such languages, Spanish included, different references can be distinguished only in part lexically. However, asemantic analysis of the Spanish word tiempo reveals its complexity as well as its conceptual, logical and lexical versatility. This is reflected in its capacity to combine in numerous lexical units, i.e. word compounds and/or phrases, endowed with different or specific semantic meanings. The repertory of these virtual and derived lexical forms appears to be practically unlimited, although their sphere of application and their boundaries are neither always very clear nor precise, which can be illustrated with the examples given in Spanish dictionaries.

  11. Polydopamine-functionalized nanographene oxide: a versatile nanocarrier for chemotherapy and photothermal therapy

    Science.gov (United States)

    Zhang, Xinyuan; Nan, Xu; Shi, Wei; Sun, Yanan; Su, Huiling; He, Yuan; Liu, Xin; Zhang, Zhong; Ge, Dongtao

    2017-07-01

    For releasing both drug and heat to selected sites, a combination of chemotherapy and photothermal therapy in one system is a more effective way to destroy cancer cells than monotherapy. Graphene oxide (GO) with high drug-loading efficiency and near-infrared (NIR) absorbance has great potential in drug delivery and photothermal therapy, but it is difficult to load drugs with high solubility. Herein, we develop a versatile drug delivery nanoplatform based on GO for integrated chemotherapy and photothermal therapy by a facile method of simultaneous reduction and surface functionalization of GO with poly(dopamine) (PDA). Due to the excellent adhesion of PDA, both low and high solubility drugs can be encapsulated in the PDA-functionalized GO nanocomposite (rGO-PDA). The fabricated nanocomposite exhibits good biocompatibility, excellent photothermal performance, high drug loading capacity, an outstanding sustained release property, and efficient endocytosis. Moreover, NIR laser irradiation facilitates the release of loaded drugs from rGO-PDA. These features make the rGO-PDA nanocomposite achieve excellent in vivo synergistic antitumor therapeutic efficacy.

  12. Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition

    Science.gov (United States)

    Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

    2017-05-01

    Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

  13. An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system.

    Science.gov (United States)

    Rossi, Bianca; Campia, Paola; Merlini, Luca; Brasca, Milena; Pastori, Nadia; Farris, Stefano; Melone, Lucio; Punta, Carlo; Galante, Yves M

    2016-06-25

    We describe a new aerogel obtained from laccase-oxidized galactomannans of the leguminous plant fenugreek (Trigonella foenum-graecum) and suggest its potential practical use. Laccase/TEMPO oxidation of fenugreek in aqueous solution caused a viscosity increase of over 15-fold. A structured, elastic, stable hydrogel was generated, due to formation of carbonyl groups from primary OH of galactose side units and subsequent establishment of hemiacetalic bonds with available free hydroxyl groups. Upon lyophilization of this hydrogel, a water-insoluble aerogel was obtained (EOLFG), capable of uptaking aqueous or organic solvents over 20 times its own weight. The material was characterized by scanning electron microscopy, FT-IR, elemental analysis and (13)C CP-MAS NMR spectroscopy and its mechanical properties were investigated. To test the EOLFG as a delivery system, the anti-microbial enzyme lysozyme was used as model active principle. Lysozyme was added before or after formation of the aerogel, entrapped or absorbed in the gel, retained and released in active form, as proven by its hydrolytic glycosidase activity on lyophilized Micrococcus lysodeikticus cells wall peptidoglycans. This new biomaterial, composed of a chemo-enzymatically modified plant polysaccharide, might represent a versatile, biocompatible "delivery system" of active principles in food and non-food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evolutionary history of versatile-lipases from Agaricales through reconstruction of ancestral structures.

    Science.gov (United States)

    Barriuso, Jorge; Martínez, María Jesús

    2017-01-03

    Fungal "Versatile carboxylic ester hydrolases" are enzymes with great biotechnological interest. Here we carried out a bioinformatic screening to find these proteins in genomes from Agaricales, by means of searching for conserved motifs, sequence and phylogenetic analysis, and three-dimensional modeling. Moreover, we reconstructed the molecular evolution of these enzymes along the time by inferring and analyzing the sequence of ancestral intermediate forms. The properties of the ancestral candidates are discussed on the basis of their three-dimensional structural models, the hydrophobicity of the lid, and the substrate binding intramolecular tunnel, revealing all of them featured properties of these enzymes. The evolutionary history of the putative lipases revealed an increase on the length and hydrophobicity of the lid region, as well as in the size of the substrate binding pocket, during evolution time. These facts suggest the enzymes' specialization towards certain substrates and their subsequent loss of promiscuity. These results bring to light the presence of different pools of lipases in fungi with different habitats and life styles. Despite the consistency of the data gathered from reconstruction of ancestral sequences, the heterologous expression of some of these candidates would be essential to corroborate enzymes' activities.

  15. Resolving complex chromosome structures during meiosis: versatile deployment of Smc5/6.

    Science.gov (United States)

    Verver, Dideke E; Hwang, Grace H; Jordan, Philip W; Hamer, Geert

    2016-03-01

    The Smc5/6 complex, along with cohesin and condensin, is a member of the structural maintenance of chromosome (SMC) family, large ring-like protein complexes that are essential for chromatin structure and function. Thanks to numerous studies of the mitotic cell cycle, Smc5/6 has been implicated to have roles in homologous recombination, restart of stalled replication forks, maintenance of ribosomal DNA (rDNA) and heterochromatin, telomerase-independent telomere elongation, and regulation of chromosome topology. The nature of these functions implies that the Smc5/6 complex also contributes to the profound chromatin changes, including meiotic recombination, that characterize meiosis. Only recently, studies in diverse model organisms have focused on the potential meiotic roles of the Smc5/6 complex. Indeed, Smc5/6 appears to be essential for meiotic recombination. However, due to both the complexity of the process of meiosis and the versatility of the Smc5/6 complex, many additional meiotic functions have been described. In this review, we provide a clear overview of the multiple functions found so far for the Smc5/6 complex in meiosis. Additionally, we compare these meiotic functions with the known mitotic functions in an attempt to find a common denominator and thereby create clarity in the field of Smc5/6 research.

  16. Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts

    Science.gov (United States)

    Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

    2005-02-01

    The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

  17. A versatile protein microarray platform enabling antibody profiling against denatured proteins.

    Science.gov (United States)

    Wang, Jie; Barker, Kristi; Steel, Jason; Park, Jin; Saul, Justin; Festa, Fernanda; Wallstrom, Garrick; Yu, Xiaobo; Bian, Xiaofang; Anderson, Karen S; Figueroa, Jonine D; LaBaer, Joshua; Qiu, Ji

    2013-06-01

    We aim to develop a protein microarray platform capable of presenting both natural and denatured forms of proteins for antibody biomarker discovery. We will further optimize plasma screening protocols to improve detection. We developed a new covalent capture protein microarray chemistry using HaloTag fusion proteins and ligand. To enhance protein yield, we used HeLa cell lysate as an in vitro transcription translation (IVTT) system. Escherichia coli lysates were added to the plasma blocking buffer to reduce nonspecific background. These protein microarrays were probed with plasma samples and autoantibody responses were quantified and compared with or without denaturing buffer treatment. We demonstrated that protein microarrays using the covalent attachment chemistry endured denaturing conditions. Blocking with E. coli lysates greatly reduced the background signals and expression with IVTT based on HeLa cell lysates significantly improved the antibody signals on protein microarrays probed with plasma samples. Plasma samples probed on denatured protein arrays produced autoantibody profiles distinct from those probed on natively displayed proteins. This versatile protein microarray platform allows the display of both natural and denatured proteins, offers a new dimension to search for disease-specific antibodies, broadens the repertoire of potential biomarkers, and will potentially yield clinical diagnostics with greater performance. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Imidazole modified g-C3N4 photocatalyst: Structural characterization and versatile energy applications

    Science.gov (United States)

    Zhang, Lu; Liu, Qianqian; Chai, Yuanyuan; Ren, Jia; Dai, Wei-Lin

    2018-02-01

    Novel imidazole modified g-C3N4 were firstly synthesized via a facile one-pot thermo-induced co-condensation method. Characterization results showed that imidazole modification can improve the visible light harvesting, interfacial charge transfer and separation of g-C3N4, without destroying its pristine framework structure. The as-obtained imidazole modified g-C3N4 showed remarkably enhanced and rather stable photocatalytic performance in H2 evolution, photo-degradation of water contaminants and selective photo-oxidation of benzyl alcohol, demonstrating its all-round applications as a versatile photocatalyst. The weight ratio between imidazole and urea was well tuned and the optimal photocatalytic activity was obtained, which shows CNU-I50 sample (50 mg imidazole in 15 g urea) possesses the highest hydrogen evolution rate of 2150 μmol g-1 h-1, superior to most of the previous reported g-C3N4 materials. These results suggest that those imidazole modified g-C3N4 materials are potential photocatalyst when applied to solar energy conversion, water purification and selective photosynthesis reactions.

  19. Versatile dual reporter gene systems for investigating stop codon readthrough in plants.

    Directory of Open Access Journals (Sweden)

    Nga T Lao

    2009-10-01

    Full Text Available Translation is most often terminated when a ribosome encounters the first in-frame stop codon (UAA, UAG or UGA in an mRNA. However, many viruses (and some cellular mRNAs contain "stop" codons that cause a proportion of ribosomes to terminate and others to incorporate an amino acid and continue to synthesize a "readthrough", or C-terminally extended, protein. This dynamic redefinition of codon meaning is dependent on specific sequence context.We describe two versatile dual reporter systems which facilitate investigation of stop codon readthrough in vivo in intact plants, and identification of the amino acid incorporated at the decoded stop codon. The first is based on the reporter enzymes NAN and GUS for which sensitive fluorogenic and histochemical substrates are available; the second on GST and GFP.We show that the NAN-GUS system can be used for direct in planta measurements of readthrough efficiency following transient expression of reporter constructs in leaves, and moreover, that the system is sufficiently sensitive to permit measurement of readthrough in stably transformed plants. We further show that the GST-GFP system can be used to affinity purify readthrough products for mass spectrometric analysis and provide the first definitive evidence that tyrosine alone is specified in vivo by a 'leaky' UAG codon, and tyrosine and tryptophan, respectively, at decoded UAA, and UGA codons in the Tobacco mosaic virus (TMV readthrough context.

  20. Ligand functionality as a versatile tool to control the assembly behavior of preformed titania nanocrystals.

    Science.gov (United States)

    Polleux, Julien; Pinna, Nicola; Antonietti, Markus; Hess, Christian; Wild, Ute; Schlögl, Robert; Niederberger, Markus

    2005-06-06

    Nanoparticle powders composed of surface-functionalized anatase crystals with diameters of about 3 nm self-organize into different structures upon redispersion in water. The assembly is directed by a small amount of a low-molecular-weight functional ligand (the "assembler") adsorbed on the surface of the nanoparticles. The ligand functionality determines the anisotropy of the resulting structures. Multidentate ligands, such as trizma ((HOCH(2))(3)CNH(2)) and serinol ((HOCH(2))(2)CNH(2)), with a chargeable terminal group preferentially induce the formation of anisotropic nanostructures several hundreds of nanometers in total length, whereas all the other investigated ligands (ethanolamine H(2)N(CH(2))(2)OH, glycine hydroxamate H(2)NCH(2)CONHOH, dopamine (OH)(2)C(6)H(3)(CH(2))(2)NH(3)Cl, tris (HOCH(2))(3)CCH(3)) mainly lead to uncontrolled agglomeration. Experimental data suggests that the anisotropic assembly is a consequence of the water-promoted desorption of the organic ligands from the {001} faces of the crystalline building blocks together with the dissociative adsorption of water on these crystal faces. Both processes induce the preferred attachment of the titania nanoparticles along the [001] direction. The use of polydentate and charged ligands to functionalize the surface of nanoparticles thus provides a versatile tool to control their arrangement on the nanoscale.

  1. Versatile RNA tetra-U helix linking motif as a toolkit for nucleic acid nanotechnology.

    Science.gov (United States)

    Bui, My N; Brittany Johnson, M; Viard, Mathias; Satterwhite, Emily; Martins, Angelica N; Li, Zhihai; Marriott, Ian; Afonin, Kirill A; Khisamutdinov, Emil F

    2017-04-01

    RNA nanotechnology employs synthetically modified ribonucleic acid (RNA) to engineer highly stable nanostructures in one, two, and three dimensions for medical applications. Despite the tremendous advantages in RNA nanotechnology, unmodified RNA itself is fragile and prone to enzymatic degradation. In contrast to use traditionally modified RNA strands e.g. 2'-fluorine, 2'-amine, 2'-methyl, we studied the effect of RNA/DNA hybrid approach utilizing a computer-assisted RNA tetra-uracil (tetra-U) motif as a toolkit to address questions related to assembly efficiency, versatility, stability, and the production costs of hybrid RNA/DNA nanoparticles. The tetra-U RNA motif was implemented to construct four functional triangles using RNA, DNA and RNA/DNA mixtures, resulting in fine-tunable enzymatic and thermodynamic stabilities, immunostimulatory activity and RNAi capability. Moreover, the tetra-U toolkit has great potential in the fabrication of rectangular, pentagonal, and hexagonal NPs, representing the power of simplicity of RNA/DNA approach for RNA nanotechnology and nanomedicine community. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Bioinspired dopamine-conjugated polyaspartamide as a novel and versatile adhesive material

    Directory of Open Access Journals (Sweden)

    B. Wang

    2017-08-01

    Full Text Available Biomimetic dopamine-conjugated polyaspartamides as novel adhesive materials were synthesized and characterized. These modified polyaspartamides contain three different groups combined with dopamine (DOPA, i.e., γ-amino butyric acid (GABA, ethanolamine (EA and octylamine (OA, which are referred to as PolyAspAm (DOPA/GABA, PolyAspAm(DOPA/EA and PolyAspAm(DOPA/OA, respectively. These three water-swollen polymer glues show good adhesion (0.1~0.4 MPa with various daily-life materials (aluminum foil, glass and paper as well as some plastic substrates (PET and PMMA. Compared to the polymers with more hydrophilic groups (GABA and EA, the polymer glue with the hydrophobic alkyl group (OA exhibited higher adhesive strength values on most substrates. In addition, when applied to biological porcine skin, these glues demonstrated adhesion of values of 15~20 kPa with EA- and OA-conjugated polymers. These results suggest the great potential of dopamine-modified polyaspartamides as versatile and efficient polymeric glues for industrial and biomedical applications.

  3. A versatile means of intracellular labeling: injection of biocytin and its detection with avidin conjugates.

    Science.gov (United States)

    Horikawa, K; Armstrong, W E

    1988-08-01

    Biocytin is a biotin-lysine complex of low molecular weight containing about 65% biotin, which retains a high affinity for avidin. Since the latter molecule has been conjugated to several histochemical markers, the use of biocytin as an intracellular marker was investigated. Electrodes were filled with a solution of 4-6% biocytin dissolved in 0.5 M KCl and 0.05 M Tris buffer, pH 7-7.6. Neurons were recorded intracellularly in the supraoptic nucleus of an explant preparation of the rat supraoptico-neurohypophysial system and injected for 1-20 min with either hyperpolarizing or depolarizing current. Following variable recovery times, the explants were fixed in either 10% formalin or 4% paraformaldehyde overnight, sectioned on a vibratome, and incubated with the avidin-biotin complex (ABC) or avidin which had been conjugated to fluorescein, rhodamine, Texas Red or horseradish peroxidase and containing 1% Triton-X 100. A high percentage of injected neurons were recovered using each of the labels with about equal success. Both negative or positive current injection could be used with little electrode clogging. Labeling with fluorescent conjugates was qualitatively similar to that of Lucifer Yellow, whereas labeling with avidin coupled to horseradish peroxidase or with ABC was qualitatively similar to filling neurons directly with horseradish peroxidase. The advantages of this technique are the ease of injection of biocytin and the versatility in allowing the investigator to choose among light-emitting and light-absorbing images.

  4. Enzyme promiscuity in earthworm serine protease: substrate versatility and therapeutic potential.

    Science.gov (United States)

    Verma, Mahendra Kumar; Pulicherla, K K

    2016-04-01

    Enzymes are the most versatile molecules in the biological world. These amazing molecules play an integral role in the regulation of various metabolic pathways and physiology subsequently. Promiscuity of an enzyme is the capacity to catalyze additional biochemical reactions besides their native one. Catalytic promiscuity has shown great impact in enzyme engineering for commercial enzyme and therapeutics with natural or engineered catalytic promiscuity. The earthworm serine protease (ESP) is a classic example of enzyme promiscuity and studied for its therapeutic potential over the last few decades. The ESP was reported for several therapeutic properties and fibrinolytic activity has been much explored. ESP, a complex enzyme exists as several isoforms of molecular weight ranging from 14 to 33 kDa. The fibrinolytic capacity of the enzyme has been studied in different species of earthworm and molecular mechanism is quite different from conventional thrombolytics. Cytotoxic and anti-tumor activities of ESP were evaluated using several cancer cell lines. Enzyme had shown tremendous scope in fighting against plant viruses and microbes. ESP is also reported for anti-inflammatory activity and anti-oxidant property. Apart from these, recently, ESP is reported for DNase activity. The daunting challenge for researchers is to understand the molecular mechanism for such diverse properties and possibility of enzyme promiscuity. This review emphasizes molecular mechanism of ESP governing various biochemical reactions. Further, the concept of enzyme promiscuity in ESP towards development of novel enzyme based drugs has been reviewed in this study.

  5. Versatile Route to Synthesize Heterobifunctional Poly(ethylene glycol of Variable Functionality for Subsequent Pegylation

    Directory of Open Access Journals (Sweden)

    Redouan Mahou

    2012-02-01

    Full Text Available Pegylation using heterotelechelic poly(ethylene glycol (PEG offers many possibilities to create high-performance molecules and materials. A versatile route is proposed to synthesize heterobifunctional PEG containing diverse combinations of azide, amine, thioacetate, thiol, pyridyl disulfide, as well as activated hydroxyl end groups. Asymmetric activation of one hydroxyl end group enables the heterobifunctionalization while applying selective monotosylation of linear, symmetrical PEG as a key step. The azide function is introduced by reacting monotosyl PEG with sodium azide. A thiol end group is obtained by reaction with sodium hydrosulfide. The activation of the hydroxyl end group and subsequent reaction with potassium carbonate/thioacetic acid yields a thioacetate end group. The hydrolysis of the thioester end group by ammonia in presence of 2,2′-dipyridyl disulfide provides PEG pyridyl disulfide. Amine terminated PEG is prepared either by reduction of the azide or by nucleophilic substitution of mesylate terminated PEG using ammonia. In all cases, >95% functionalization of the PEG end groups is achieved. The PEG derivatives particularly support the development of materials for biomedical applications. For example, grafting up to 13% of the Na-alg monomer units with α-amine-ω-thiol PEG maintains the gelling capacity in presence of calcium ions but simultaneous, spontaneous disulfide bond formation reinforces the initial physical hydrogel.

  6. Versatile common instrumentation for optical detection of pH and dissolved oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Sardesai, Neha [Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Rao, Govind [Center for Advanced Sensor Technology and Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Kostov, Yordan, E-mail: kostov@umbc.edu [Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Center for Advanced Sensor Technology and Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States)

    2015-07-15

    The recent trend toward use of disposable and miniature bioreactors requires the use of appropriate sensors. pH and dissolved oxygen (DO) are often measured using optical chemical sensors due to their small form factor and convenience in use. These sensors are often interrogated using a specialized opto-electronic transducer that is designed around the optical sensor. In this contribution, we are presenting a new class of opto-electronic transducers that are usable with several different chemical sensors without the need to switch the optics or hardware when changing the type of the chemical sensor. This allows flexibility closer to the lab-grade devices while the size is closer to a dedicated sensor. This versatile instrumentation is capable of seamlessly switching between the pH and DO measurement modes and is capable of auto recognition of the sensor type. The principle of ratiometric fluorescence is used for pH measurements, and that of fluorescence lifetime for DO measurements. An approach to obtain identical calibrations between several devices is also presented. The described hardware constitutes common instrumentation for measuring either pH or DO and has been tested in actual bioprocesses. It has been found adequate for continuous bioprocess monitoring.

  7. 1,2-HOIQO--A highly versatile 1,2-HOPO analog

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Michael; Pluth, Michael D.; Raymond, Kenneth N.

    2006-08-07

    A cyclic, bidentate hydroxamic acid binding unit based on an isoquinoline scaffold has been utilized for the synthesis of a hexadentate tripodal ligand based on the TREN backbone. This prototype for a new class of multidentate chelators forms mononuclear iron(III) complexes and one-dimensional coordination polymers with lanthanide(III) cations. The latter has been determined by single crystal X-ray analysis of the cerium species. The solid state structure in the monoclinic space group P2{sub 1}/c (C{sub 36}H{sub 34}CeN{sub 7}O{sub 11}, a = 12.341(2){angstrom}, b = 26.649(4){angstrom}, c = 10.621(2){angstrom}, {alpha} = {gamma} = 90{sup o}, {beta} = 96.753(3){sup o}, V = 3468.6(9) {angstrom}{sup 3}, Z = 4) exhibits a trigonal-dodecahedral environment around the cerium cation. The proof of concept for the versatility of the new scaffold has been shown by the modification of the crucial precursor 3-carboxyiso-coumarin through electrophilic aromatic substitutions to yield the corresponding chlorosulfonated and nitrated analogs.

  8. Functionalized PDMS with versatile and scalable surface roughness gradients for cell culture

    KAUST Repository

    Zhou, Bingpu

    2015-07-21

    This manuscript describes a simple and versatile approach to engineering surface roughness gradients via combination of microfluidics and photo-polymerization. Through UV-mediated polymerization, N-isopropylacrylamide with concentration gradients are successfully grafted onto PDMS surface, leading to diverse roughness degrees on the obtained PDMS substrate. Furthermore, the extent of surface roughness can be controllably regulated via tuning the flow rate ratio between the monomer solution and deionized water. Average roughness ranging from 8.050 nm to 151.68 nm has well been achieved in this work. Such PDMS samples are also demonstrated to be capable of working as supporting substrates for controlling cell adhesion or detachment. Due to the different degrees of surface roughness on a single substrate, our method provides an effective approach for designing advanced surafecs for cell culture. Finally, the thermosensitive property of N-isopropylacrylamide makes our sample furnish as another means for controlling the cell detachment from the substrates with correspondence to the surrounding temperature.

  9. Nucleolin-targeted Extracellular Vesicles as a Versatile Platform for Biologics Delivery to Breast Cancer.

    Science.gov (United States)

    Wang, Yayu; Chen, Xiaojia; Tian, Baoqing; Liu, Jiafan; Yang, Li; Zeng, Lilan; Chen, Tianfen; Hong, An; Wang, Xiaogang

    2017-01-01

    Small interfering RNAs (siRNA)/microRNAs (miRNA) have promising therapeutic potential, yet their clinical application has been hampered by the lack of appropriate delivery systems. Herein, we employed extracellular vesicles (EVs) as a targeted delivery system for small RNAs. EVs are cell-derived small vesicles that participate in cell-to-cell communication for protein and RNA delivery. We used the aptamer AS1411-modified EVs for targeted delivery of siRNA/microRNA to breast cancer tissues. Tumor targeting was facilitated via AS1411 binding to nucleolin, which is highly expressed on the surface membrane of breast cancer cells. This delivery vesicle targeted let-7 miRNA delivery to MDA-MB-231 cells in vitro as confirmed with fluorescent microscopic imaging and flow cytometry. Also, intravenously delivered AS1411-EVs loaded with miRNA let-7 labeled with the fluorescent marker, Cy5, selectively targeted tumor tissues in tumor-bearing mice and inhibited tumor growth. Importantly, the modified EVs were well tolerated and showed no evidence of nonspecific side effects or immune response. Thus, the RNAi nanoplatform is versatile and can deliver siRNA or miRNA to breast cancer cells both in vitro and in vivo. Our results suggest that the AS1411-EVs have a great potential as drug delivery vehicles to treat cancers.

  10. Effect of heavy metals on bacterial transport

    Science.gov (United States)

    Zhang, H.; Olson, M. S.

    2010-12-01

    Adsorption of metals onto bacteria and soil takes place as stormwater runoff infiltrates into the subsurface. Changes in both bacterial surfaces and soil elemental content have been observed, and may alter the attachment of bacteria to soil surfaces. In this study, scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS) analyses were performed on soil samples equilibrated with synthetic stormwater amended with copper, lead and zinc. The results demonstrate the presence of copper and zinc on soil surfaces. To investigate bacterial attachment behavior, sets of batch sorption experiments were conducted on Escherichia Coli (E. coli) under different chemical conditions by varying solution compositions (nutrient solution vs synthetic stormwater). The adsorption data is best described using theoretical linear isotherms. The equilibrium coefficient (Kd) of E. coli is higher in synthetic stormwater than in nutrient solution without heavy metals. The adsorption of heavy metals onto bacterial surfaces significantly decreases their negative surface charge as determined via zeta potential measurements (-17.0±5.96mv for E. coli equilibrated with synthetic stormwater vs -21.6±5.45mv for E. coli equilibrated with nutrient solution), indicating that bacterial attachment may increase due to the attachment of metals onto bacterial surfaces and their subsequent change in surface charge. The attachment efficiency (α) of bacteria was also calculated and compared for both solution chemistries. Bacterial attachment efficiency (α) in synthetic stormwater is 0.997, which is twice as high as that in nutrient solution(α 0.465). The ratio of bacterial diameter : collector diameter suggests minimal soil straining during bacterial transport. Results suggest that the presence of metals in synthetic stormwater leads to an increase in bacterial attachment to soil surfaces. In terms of designing stormwater infiltration basins, the presence of heavy metals seems to

  11. Bacterial biofilms and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Liliana Caldas-Arias

    2015-04-01

    Full Text Available Biofilms give to bacteria micro-environmental benefits; confers protection against antimicrobials. Bacteria have antibiotic resistance by conventional and unusual mechanisms leading to delayed wound healing, to increase recurrent chronic infections and nosocomial contamination of medical devices. Objective: This narrative review aims to introduce the characteristics of Bacteria-biofilms, antimicrobial resistance mechanisms and potential alternatives for prevention and control of its formation. Methods: Search strategy was performed on records: PubMed / Medline, Lilacs, Redalyc; with suppliers such as EBSCO and thesaurus MeSH and DeCS. Conclusions: Knowledge and research performance of biofilm bacteria are relevant in the search of technology for detection and measuring sensitivity to antibiotics. The identification of Bacterial-biofilms needs no-traditional microbiological diagnosis.

  12. Bacterial interactions in dental biofilm.

    Science.gov (United States)

    Huang, Ruijie; Li, Mingyun; Gregory, Richard L

    2011-01-01

    Biofilms are masses of microorganisms that bind to and multiply on a solid surface, typically with a fluid bathing the microbes. The microorganisms that are not attached but are free floating in an aqueous environment are termed planktonic cells. Traditionally, microbiology research has addressed results from planktonic bacterial cells. However, many recent studies have indicated that biofilms are the preferred form of growth of most microbes and particularly those of a pathogenic nature. Biofilms on animal hosts have significantly increased resistance to various antimicrobials compared to planktonic cells. These microbial communities form microcolonies that interact with each other using very sophisticated communication methods (i.e., quorum-sensing). The development of unique microbiological tools to detect and assess the various biofilms around us is a tremendously important focus of research in many laboratories. In the present review, we discuss the major biofilm mechanisms and the interactions among oral bacteria.

  13. Bacterial Exopolysaccharides: Functionality and Prospects

    Science.gov (United States)

    Nwodo, Uchechukwu U.; Green, Ezekiel; Okoh, Anthony I.

    2012-01-01

    Diverse structural, functional and valuable polysaccharides are synthesized by bacteria of all taxa and secreted into the external environment. These polysaccharides are referred to as exopolysaccharides and they may either be homopolymeric or heteropolymeric in composition and of diverse high molecular weights (10 to 1000 kDa). The material properties of exopolysaccharides have revolutionized the industrial and medical sectors due to their retinue of functional applications and prospects. These applications have been extensive in areas such as pharmacological, nutraceutical, functional food, cosmeceutical, herbicides and insecticides among others, while prospects includes uses as anticoagulant, antithrombotic, immunomodulation, anticancer and as bioflocculants. Due to the extensive applications of bacterial exopolysaccharides, this overview provides basic information on their physiologic and morphologic functions as well as their applications and prospects in the medical and industrial sectors. PMID:23203046

  14. Corticosteroids for acute bacterial meningitis.

    Science.gov (United States)

    Brouwer, Matthijs C; McIntyre, Peter; Prasad, Kameshwar; van de Beek, Diederik

    2015-09-12

    In experimental studies, the outcome of bacterial meningitis has been related to the severity of inflammation in the subarachnoid space. Corticosteroids reduce this inflammatory response. To examine the effect of adjuvant corticosteroid therapy versus placebo on mortality, hearing loss and neurological sequelae in people of all ages with acute bacterial meningitis. We searched CENTRAL (2015, Issue 1), MEDLINE (1966 to January week 4, 2015), EMBASE (1974 to February 2015), Web of Science (2010 to February 2015), CINAHL (2010 to February 2015) and LILACS (2010 to February 2015). Randomised controlled trials (RCTs) of corticosteroids for acute bacterial meningitis. We scored RCTs for methodological quality. We collected outcomes and adverse effects. We performed subgroup analyses for children and adults, causative organisms, low-income versus high-income countries, time of steroid administration and study quality. We included 25 studies involving 4121 participants (2511 children and 1517 adults; 93 mixed population). Four studies were of high quality with no risk of bias, 14 of medium quality and seven of low quality, indicating a moderate risk of bias for the total analysis. Nine studies were performed in low-income countries and 16 in high-income countries.Corticosteroids were associated with a non-significant reduction in mortality (17.8% versus 19.9%; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.80 to 1.01, P value = 0.07). A similar non-significant reduction in mortality was observed in adults receiving corticosteroids (RR 0.74, 95% CI 0.53 to 1.05, P value = 0.09). Corticosteroids were associated with lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.74, 95% CI 0.63 to 0.87) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00).Subgroup analyses for causative organisms showed that corticosteroids reduced mortality in Streptococcus pneumoniae (S. pneumoniae) meningitis (RR 0.84, 95% CI 0.72 to 0.98), but not in

  15. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  16. Bacterial Actins? An Evolutionary Perspective

    Science.gov (United States)

    Doolittle, Russell F.; York, Amanda L.

    2003-01-01

    According to the conventional wisdom, the existence of a cytoskeleton in eukaryotes and its absence in prokaryotes constitute a fundamental divide between the two domains of life. An integral part of the dogma is that a cytoskeleton enabled an early eukaryote to feed upon prokaryotes, a consequence of which was the occasional endosymbiosis and the eventual evolution of organelles. Two recent papers present compelling evidence that actin, one of the principal components of a cytoskeleton, has a homolog in Bacteria that behaves in many ways like eukaryotic actin. Sequence comparisons reveml that eukaryotic actin and the bacterial homolog (mreB protein), unlike many other proteins common to eukaryotes and Bacteria, have very different and more highly extended evolutionary histories.

  17. Bacterial mycophagy: definition and diagnosis of a unique bacterial-fungal interaction

    NARCIS (Netherlands)

    Leveau, J.H.J.; Preston, G.M.

    2008-01-01

    This review analyses the phenomenon of bacterial mycophagy, which we define as a set of phenotypic behaviours that enable bacteria to obtain nutrients from living fungi and thus allow the conversion of fungal into bacterial biomass. We recognize three types of bacterial strategies to derive

  18. Melatonin in bacterial and viral infections with focus on sepsis: a review.

    Science.gov (United States)

    Srinivasan, Venkataramanujam; Mohamed, Mahaneem; Kato, Hisanori

    2012-01-01

    Melatonin is a versatile molecule, synthesized not only by the pineal gland, but also in small amounts by many other organs like retina, gastrointestinal tract, thymus, bone marrow, lymphocytes etc. It plays an important role in various functions of the body like sleep and circadian rhythm regulation, immunoregulatory mechanism, free radical scavenger, antioxidant functions, oncostatic actions, control of reproductive functions, regulation of mood etc. Melatonin has also been found to be effective in combating various bacterial and viral infections. Its administration has been shown to be effective in controlling chlamydial infections, infections induced by Mycobacterium tuberculosis, and also in many viral infections. Molecular mechanisms of anti microbial actions of melatonin have suggested to be due to effects on free radical formation, direct regulation of duplication of bacteria, depletion of intracellular substrates like iron etc. Besides, it is effective in sepsis as demonstrated in various animal models of septic shock. Melatonin's protective action against sepsis is suggested to be due to its antioxidant, immunomodulating and inhibitory actions against the production and activation of pro-inflammatory mediators. Use of melatonin has been beneficial in treating premature infants suffering from severe respiratory distress syndrome and septic shock. It has a potential therapeutic value in treating septic shock and associated multi organ failure in critically ill patients in addition to its antimicrobial and antiviral actions. The patents related to melatonin's use for treatment of bacterial infections and its use in clinical disorders are included.

  19. Trends in therapeutic drug conjugates for bacterial diseases: a patent review.

    Science.gov (United States)

    Cal, Pedro M S D; Matos, Maria J; Bernardes, Gonçalo J L

    2017-02-01

    Drug conjugates are trend topics in Chemical Biology. These entities are an emerging class of highly potent biopharmaceutical drugs, best known in the field of oncology, that have been also designed as a targeted therapy/diagnosis for the treatment/prevention of several bacterial diseases. Antibiotic resistance is now a major threat to public health, and targeted strategies can reduce resistance. The following review aims at giving an overview of the patented therapeutic innovations covering these areas. Particular attention has been given to antibacterial drug conjugates in the last 30 years. Areas covered: The authors provide an overview of the scientific reports describing the research and development of new drug conjugates for bacterial diseases. The review emphasizes the rationale behind synthesis, biological activities and improvement of the new drug conjugates. New technologies applied for the research in this field have also been discussed. The article is based on the most relevant literature related to the development of new therapeutic solutions. The patents presented in this review have been collected from multiple electronic databases including SciFinder, Pubmed, Espacenet and Mendeley. Expert opinion: The new drug conjugates described in the current review proved to display improved delivery, efficacy, targeting abilities and fewer side effects. Versatile approaches were invented to achieve these goals.

  20. Efficacy of highly water-dispersed fabricated nano ZnO against clinically isolated bacterial strains

    Science.gov (United States)

    Mitra, Shouvik; Patra, Prasun; Chandra, Sourov; Pramanik, Panchanan; Goswami, Arunava

    2012-09-01

    Versatile use of zinc oxide nanoparticles (ZNPs) in semiconductors, optical device and solar cells has already been established. Herein we describe synthesis of surface-functionalized ZNP to highly water dispersible constituent and its antibacterial efficiency against clinically isolated bacterial system. ZNP was synthesized by single-step microwave-assisted route using an aqueous buffer solution. Surface of ZNP was functionalized by grafting of phosphonoacetic acid as the coupling agent. Transmission electron microscopy image suggested that functionalized ZNP was smaller in size in comparison with unfunctionalized one. Antibacterial activity against clinically isolated bacterial strains of Escherichia coli, Staphylococcus aureus and Klebseilla sp. was detected with dose dependency. Functionalized ZNP claimed hexagonal crystal structure and exhibited higher dispersibility in aqueous solution which resulted in the production of greater reactive oxygen species and hence destruction of cell membrane leading to its biocidal efficacy. It is worth mentioning that functionalized dispersed fabricated ZNP would be used as potent biocides in medical as well as agricultural sector.